netlink: let core handle error cases in dump operations

After commit b5a899154aa9 ("netlink: handle EMSGSIZE errors
in the core"), we can remove some code that was not 100 % correct
anyway.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20240306102426.245689-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

inet: use xa_array iterator to implement inet_dump_ifaddr()

1) inet_dump_ifaddr() can can run under RCU protection
instead of RTNL.

2) properly return 0 at the end of a dump, avoiding an
an extra recvmsg() system call.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

inet: prepare inet_base_seq() to run without RTNL

In the following patch, inet_base_seq() will no longer be called
with RTNL held.

Add READ_ONCE()/WRITE_ONCE() annotations in dev_base_seq_inc()
and inet_base_seq().

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

inet: annotate data-races around ifa->ifa_flags

ifa->ifa_flags can be read locklessly.

Add appropriate READ_ONCE()/WRITE_ONCE() annotations.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

inet: annotate data-races around ifa->ifa_preferred_lft

ifa->ifa_preferred_lft can be read locklessly.

Add appropriate READ_ONCE()/WRITE_ONCE() annotations.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

inet: annotate data-races around ifa->ifa_valid_lft

ifa->ifa_valid_lft can be read locklessly.

Add appropriate READ_ONCE()/WRITE_ONCE() annotations.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

inet: annotate data-races around ifa->ifa_tstamp and ifa->ifa_cstamp

ifa->ifa_tstamp can be read locklessly.

Add appropriate READ_ONCE()/WRITE_ONCE() annotations.

Do the same for ifa->ifa_cstamp to prepare upcoming changes.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

inet: use xa_array iterator to implement inet_netconf_dump_devconf()

1) inet_netconf_dump_devconf() can run under RCU protection
instead of RTNL.

2) properly return 0 at the end of a dump, avoiding an
an extra recvmsg() system call.

3) Do not use inet_base_seq() anymore, for_each_netdev_dump()
has nice properties. Restarting a GETDEVCONF dump if a device has
been added/removed or if net->ipv4.dev_addr_genid has changed is moot.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20240227092411.2315725-4-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

inet: do not use RTNL in inet_netconf_get_devconf()

"ip -4 netconf show dev XXXX" no longer acquires RTNL.

Return -ENODEV instead of -EINVAL if no netdev or idev can be found.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20240227092411.2315725-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

inet: annotate devconf data-races

Add READ_ONCE() in ipv4_devconf_get() and corresponding
WRITE_ONCE() in ipv4_devconf_set()

Add IPV4_DEVCONF_RO() and IPV4_DEVCONF_ALL_RO() macros,
and use them when reading devconf fields.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20240227092411.2315725-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

ipv4: properly combine dev_base_seq and ipv4.dev_addr_genid

net->dev_base_seq and ipv4.dev_addr_genid are monotonically increasing.

If we XOR their values, we could miss to detect if both values
were changed with the same amount.

Fixes: 0465277f6b3f ("ipv4: provide addr and netconf dump consistency info")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ipv4: fix one memleak in __inet_del_ifa()

I got the below warning when do fuzzing test:
unregister_netdevice: waiting for bond0 to become free. Usage count = 2

It can be repoduced via:

ip link add bond0 type bond
sysctl -w net.ipv4.conf.bond0.promote_secondaries=1
ip addr add 4.117.174.103/0 scope 0x40 dev bond0
ip addr add 192.168.100.111/255.255.255.254 scope 0 dev bond0
ip addr add 0.0.0.4/0 scope 0x40 secondary dev bond0
ip addr del 4.117.174.103/0 scope 0x40 dev bond0
ip link delete bond0 type bond

In this reproduction test case, an incorrect 'last_prim' is found in
__inet_del_ifa(), as a result, the secondary address(0.0.0.4/0 scope 0x40)
is lost. The memory of the secondary address is leaked and the reference of
in_device and net_device is leaked.

Fix this problem:
Look for 'last_prim' starting at location of the deleted IP and inserting
the promoted IP into the location of 'last_prim'.

Fixes: 0ff60a45678e ("[IPV4]: Fix secondary IP addresses after promotion")
Signed-off-by: Liu Jian <liujian56@huawei.com>
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>

IPv4: add extack info for IPv4 address add/delete

Add extack info for IPv4 address add/delete, which would be useful for
users to understand the problem without having to read kernel code.

No extack message for the ifa_local checking in __inet_insert_ifa() as
it has been checked in find_matching_ifa().

Suggested-by: Ido Schimmel <idosch@idosch.org>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

networking: Update to register_net_sysctl_sz

Move from register_net_sysctl to register_net_sysctl_sz for all the
networking related files. Do this while making sure to mirror the NULL
assignments with a table_size of zero for the unprivileged users.

We need to move to the new function in preparation for when we change
SIZE_MAX to ARRAY_SIZE() in the register_net_sysctl macro. Failing to do
so would erroneously allow ARRAY_SIZE() to be called on a pointer. We
hold off the SIZE_MAX to ARRAY_SIZE change until we have migrated all
the relevant net sysctl registering functions to register_net_sysctl_sz
in subsequent commits.

An additional size function was added to the following files in order to
calculate the size of an array that is defined in another file:
include/net/ipv6.h
net/ipv6/icmp.c
net/ipv6/route.c
net/ipv6/sysctl_net_ipv6.c

Signed-off-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

net: ipv4: Allow changing IPv4 address protocol

When IP address protocol field was added in commit 47f0bd503210 ("net: Add
new protocol attribute to IP addresses"), the semantics included the
ability to change the protocol for IPv6 addresses, but not for IPv4
addresses. It seems this was not deliberate, but rather by accident.

A userspace that wants to change the protocol of an address might drop and
recreate the address, but that disrupts routing and is just impractical.

So in this patch, when an IPv4 address is replaced (through RTM_NEWADDR
request with NLM_F_REPLACE flag), update the proto at the address to the
one given in the request, or zero if none is given. This matches the
behavior of IPv6. Previously, any new value given was simply ignored.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: devinet: Reduce refcount before grace period

Currently, the inetdev_destroy() function waits for an RCU grace period
before decrementing the refcount and freeing memory. This causes a delay
with a new RCU configuration that tries to save power, which results in the
network interface disappearing later than expected. The resulting delay
causes test failures on ChromeOS.

Refactor the code such that the refcount is freed before the grace period
and memory is freed after. With this a ChromeOS network test passes that
does 'ip netns del' and polls for an interface disappearing, now passes.

Reported-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: David Ahern <dsahern@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: <netdev@vger.kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

net: Fix data-races around sysctl_devconf_inherit_init_net.

While reading sysctl_devconf_inherit_init_net, it can be changed
concurrently. Thus, we need to add READ_ONCE() to its readers.

Fixes: 856c395cfa63 ("net: introduce a knob to control whether to inherit devconf config")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rename reference+tracking helpers

Netdev reference helpers have a dev_ prefix for historic
reasons. Renaming the old helpers would be too much churn
but we can rename the tracking ones which are relatively
recent and should be the default for new code.

Rename:
dev_hold_track() -> netdev_hold()
dev_put_track() -> netdev_put()
dev_replace_track() -> netdev_ref_replace()

Link: https://lore.kernel.org/r/20220608043955.919359-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

random32: use real rng for non-deterministic randomness

random32.c has two random number generators in it: one that is meant to
be used deterministically, with some predefined seed, and one that does
the same exact thing as random.c, except does it poorly. The first one
has some use cases. The second one no longer does and can be replaced
with calls to random.c's proper random number generator.

The relatively recent siphash-based bad random32.c code was added in
response to concerns that the prior random32.c was too deterministic.
Out of fears that random.c was (at the time) too slow, this code was
anonymously contributed. Then out of that emerged a kind of shadow
entropy gathering system, with its own tentacles throughout various net
code, added willy nilly.

Stop👏making👏bespoke👏random👏number👏generators👏.

Fortunately, recent advances in random.c mean that we can stop playing
with this sketchiness, and just use get_random_u32(), which is now fast
enough. In micro benchmarks using RDPMC, I'm seeing the same median
cycle count between the two functions, with the mean being _slightly_
higher due to batches refilling (which we can optimize further need be).
However, when doing *real* benchmarks of the net functions that actually
use these random numbers, the mean cycles actually *decreased* slightly
(with the median still staying the same), likely because the additional
prandom code means icache misses and complexity, whereas random.c is
generally already being used by something else nearby.

The biggest benefit of this is that there are many users of prandom who
probably should be using cryptographically secure random numbers. This
makes all of those accidental cases become secure by just flipping a
switch. Later on, we can do a tree-wide cleanup to remove the static
inline wrapper functions that this commit adds.

There are also some low-ish hanging fruits for making this even faster
in the future: a get_random_u16() function for use in the networking
stack will give a 2x performance boost there, using SIMD for ChaCha20
will let us compute 4 or 8 or 16 blocks of output in parallel, instead
of just one, giving us large buffers for cheap, and introducing a
get_random_*_bh() function that assumes irqs are already disabled will
shave off a few cycles for ordinary calls. These are things we can chip
away at down the road.

Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

memcg: accounting for objects allocated for new netdevice

Creating a new netdevice allocates at least ~50Kb of memory for various
kernel objects, but only ~5Kb of them are accounted to memcg. As a result,
creating an unlimited number of netdevice inside a memcg-limited container
does not fall within memcg restrictions, consumes a significant part
of the host's memory, can cause global OOM and lead to random kills of
host processes.

The main consumers of non-accounted memory are:
~10Kb 80+ kernfs nodes
~6Kb ipv6_add_dev() allocations
6Kb __register_sysctl_table() allocations
4Kb neigh_sysctl_register() allocations
4Kb __devinet_sysctl_register() allocations
4Kb __addrconf_sysctl_register() allocations

Accounting of these objects allows to increase the share of memcg-related
memory up to 60-70% (~38Kb accounted vs ~54Kb total for dummy netdevice
on typical VM with default Fedora 35 kernel) and this should be enough
to somehow protect the host from misuse inside container.

Other related objects are quite small and may not be taken into account
to minimize the expected performance degradation.

It should be separately mentonied ~300 bytes of percpu allocation
of struct ipstats_mib in snmp6_alloc_dev(), on huge multi-cpu nodes
it can become the main consumer of memory.

This patch does not enables kernfs accounting as it affects
other parts of the kernel and should be discussed separately.
However, even without kernfs, this patch significantly improves the
current situation and allows to take into account more than half
of all netdevice allocations.

Signed-off-by: Vasily Averin <vvs@openvz.org>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/354a0a5f-9ec3-a25c-3215-304eab2157bc@openvz.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: Add new protocol attribute to IP addresses

This patch adds a new protocol attribute to IPv4 and IPv6 addresses.
Inspiration was taken from the protocol attribute of routes. User space
applications like iproute2 can set/get the protocol with the Netlink API.

The attribute is stored as an 8-bit unsigned integer.

The protocol attribute is set by kernel for these categories:

- IPv4 and IPv6 loopback addresses
- IPv6 addresses generated from router announcements
- IPv6 link local addresses

User space may pass custom protocols, not defined by the kernel.

Grouping addresses on their origin is useful in scenarios where you want
to distinguish between addresses based on who added them, e.g. kernel
vs. user space.

Tagging addresses with a string label is an existing feature that could be
used as a solution. Unfortunately the max length of a label is
15 characters, and for compatibility reasons the label must be prefixed
with the name of the device followed by a colon. Since device names also
have a max length of 15 characters, only -1 characters is guaranteed to be
available for any origin tag, which is not that much.

A reference implementation of user space setting and getting protocols
is available for iproute2:

https://github.com/westermo/iproute2/commit/9a6ea18bd79f47f293e5edc7780f315ea42ff540

Signed-off-by: Jacques de Laval <Jacques.De.Laval@westermo.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20220217150202.80802-1-Jacques.De.Laval@westermo.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

ipv4: add net device refcount tracker to struct in_device

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: return correct error code

When kmemdup called failed and register_net_sysctl return NULL, should
return ENOMEM instead of ENOBUFS

Signed-off-by: liuguoqiang <liuguoqiang@uniontech.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: arp: introduce arp_evict_nocarrier sysctl parameter

This change introduces a new sysctl parameter, arp_evict_nocarrier.
When set (default) the ARP cache will be cleared on a NOCARRIER event.
This new option has been defaulted to '1' which maintains existing
behavior.

Clearing the ARP cache on NOCARRIER is relatively new, introduced by:

commit 859bd2ef1fc1110a8031b967ee656c53a6260a76
Author: David Ahern <dsahern@gmail.com>
Date: Thu Oct 11 20:33:49 2018 -0700

net: Evict neighbor entries on carrier down

The reason for this changes is to prevent the ARP cache from being
cleared when a wireless device roams. Specifically for wireless roams
the ARP cache should not be cleared because the underlying network has not
changed. Clearing the ARP cache in this case can introduce significant
delays sending out packets after a roam.

A user reported such a situation here:

https://lore.kernel.org/linux-wireless/CACsRnHWa47zpx3D1oDq9JYnZWniS8yBwW1h0WAVZ6vrbwL_S0w@mail.gmail.com/

After some investigation it was found that the kernel was holding onto
packets until ARP finished which resulted in this 1 second delay. It
was also found that the first ARP who-has was never responded to,
which is actually what caues the delay. This change is more or less
working around this behavior, but again, there is no reason to clear
the cache on a roam anyways.

As for the unanswered who-has, we know the packet made it OTA since
it was seen while monitoring. Why it never received a response is
unknown. In any case, since this is a problem on the AP side of things
all that can be done is to work around it until it is solved.

Some background on testing/reproducing the packet delay:

Hardware:
- 2 access points configured for Fast BSS Transition (Though I don't
see why regular reassociation wouldn't have the same behavior)
- Wireless station running IWD as supplicant
- A device on network able to respond to pings (I used one of the APs)

Procedure:
- Connect to first AP
- Ping once to establish an ARP entry
- Start a tcpdump
- Roam to second AP
- Wait for operstate UP event, and note the timestamp
- Start pinging

Results:

Below is the tcpdump after UP. It was recorded the interface went UP at
10:42:01.432875.

10:42:01.461871 ARP, Request who-has 192.168.254.1 tell 192.168.254.71, length 28
10:42:02.497976 ARP, Request who-has 192.168.254.1 tell 192.168.254.71, length 28
10:42:02.507162 ARP, Reply 192.168.254.1 is-at ac:86:74:55:b0:20, length 46
10:42:02.507185 IP 192.168.254.71 > 192.168.254.1: ICMP echo request, id 52792, seq 1, length 64
10:42:02.507205 IP 192.168.254.71 > 192.168.254.1: ICMP echo request, id 52792, seq 2, length 64
10:42:02.507212 IP 192.168.254.71 > 192.168.254.1: ICMP echo request, id 52792, seq 3, length 64
10:42:02.507219 IP 192.168.254.71 > 192.168.254.1: ICMP echo request, id 52792, seq 4, length 64
10:42:02.507225 IP 192.168.254.71 > 192.168.254.1: ICMP echo request, id 52792, seq 5, length 64
10:42:02.507232 IP 192.168.254.71 > 192.168.254.1: ICMP echo request, id 52792, seq 6, length 64
10:42:02.515373 IP 192.168.254.1 > 192.168.254.71: ICMP echo reply, id 52792, seq 1, length 64
10:42:02.521399 IP 192.168.254.1 > 192.168.254.71: ICMP echo reply, id 52792, seq 2, length 64
10:42:02.521612 IP 192.168.254.1 > 192.168.254.71: ICMP echo reply, id 52792, seq 3, length 64
10:42:02.521941 IP 192.168.254.1 > 192.168.254.71: ICMP echo reply, id 52792, seq 4, length 64
10:42:02.522419 IP 192.168.254.1 > 192.168.254.71: ICMP echo reply, id 52792, seq 5, length 64
10:42:02.523085 IP 192.168.254.1 > 192.168.254.71: ICMP echo reply, id 52792, seq 6, length 64

You can see the first ARP who-has went out very quickly after UP, but
was never responded to. Nearly a second later the kernel retries and
gets a response. Only then do the ping packets go out. If an ARP entry
is manually added prior to UP (after the cache is cleared) it is seen
that the first ping is never responded to, so its not only an issue with
ARP but with data packets in general.

As mentioned prior, the wireless interface was also monitored to verify
the ping/ARP packet made it OTA which was observed to be true.

Signed-off-by: James Prestwood <prestwoj@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: add extack arg for link ops

Pass extack arg to validate_linkmsg and validate_link_af callbacks.
If a netlink attribute has a reject_message, use the extended ack
mechanism to carry the message back to user space.

Signed-off-by: Rocco Yue <rocco.yue@mediatek.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: socket: remove register_gifconf

Since dynamic registration of the gifconf() helper is only used for
IPv4, and this can not be in a loadable module, this can be simplified
noticeably by turning it into a direct function call as a preparation
for cleaning up the compat handling.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ipv4: add capability check for net administration

Root in init user namespace can modify /proc/sys/net/ipv4/ip_forward
without CAP_NET_ADMIN, this doesn't follow the principle of
capabilities. For example, let's take a look at netdev_store(),
root can't modify netdev attribute without CAP_NET_ADMIN.
So let's keep the consistency of permission check logic.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Yang Yang <yang.yang29@zte.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>

memcg: enable accounting for IP address and routing-related objects

An netadmin inside container can use 'ip a a' and 'ip r a'
to assign a large number of ipv4/ipv6 addresses and routing entries
and force kernel to allocate megabytes of unaccounted memory
for long-lived per-netdevice related kernel objects:
'struct in_ifaddr', 'struct inet6_ifaddr', 'struct fib6_node',
'struct rt6_info', 'struct fib_rules' and ip_fib caches.

These objects can be manually removed, though usually they lives
in memory till destroy of its net namespace.

It makes sense to account for them to restrict the host's memory
consumption from inside the memcg-limited container.

One of such objects is the 'struct fib6_node' mostly allocated in
net/ipv6/route.c::__ip6_ins_rt() inside the lock_bh()/unlock_bh() section:

write_lock_bh(&table->tb6_lock);
err = fib6_add(&table->tb6_root, rt, info, mxc);
write_unlock_bh(&table->tb6_lock);

In this case it is not enough to simply add SLAB_ACCOUNT to corresponding
kmem cache. The proper memory cgroup still cannot be found due to the
incorrect 'in_interrupt()' check used in memcg_kmem_bypass().

Obsoleted in_interrupt() does not describe real execution context properly.
>From include/linux/preempt.h:

The following macros are deprecated and should not be used in new code:
in_interrupt() - We're in NMI,IRQ,SoftIRQ context or have BH disabled

To verify the current execution context new macro should be used instead:
in_task() - We're in task context

Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: avoid RCU read lock when holding RTNL

When we call af_ops->set_link_af() we hold a RCU read lock
as we retrieve af_ops from the RCU protected list, but this
is unnecessary because we already hold RTNL lock, which is
the writer lock for protecting rtnl_af_ops, so it is safer
than RCU read lock. Similar for af_ops->validate_link_af().

This was not a problem until we begin to take mutex lock
down the path of ->set_link_af() in __ipv6_dev_mc_dec()
recently. We can just drop the RCU read lock there and
assert RTNL lock.

Reported-and-tested-by: syzbot+7d941e89dd48bcf42573@syzkaller.appspotmail.com
Fixes: 63ed8de4be81 ("mld: add mc_lock for protecting per-interface mld data")
Tested-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ipv4: Remove unneed BUG() function

When 'nla_parse_nested_deprecated' failed, it's no need to
BUG() here, return -EINVAL is ok.

Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv6: report errors for iftoken via netlink extack

Setting iftoken can fail for several different reasons but there
and there was no report to user as to the cause. Add netlink
extended errors to the processing of the request.

This requires adding additional argument through rtnl_af_ops
set_link_af callback.

Reported-by: Hongren Zheng <li@zenithal.me>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

treewide: rename nla_strlcpy to nla_strscpy.

Calls to nla_strlcpy are now replaced by calls to nla_strscpy which is the new
name of this function.

Signed-off-by: Francis Laniel <laniel_francis@privacyrequired.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: ipv4: remove redundant initialization in inet_rtm_deladdr

The initialization for 'err' with '-EINVAL' is redundant and
can be removed, as it is updated soon.

Changes since v1:
- Remove redundant empty line

Signed-off-by: Menglong Dong <dong.menglong@zte.com.cn>
Link: https://lore.kernel.org/r/20201108010541.12432-1-dong.menglong@zte.com.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

devinet: fix memleak in inetdev_init()

When devinet_sysctl_register() failed, the memory allocated
in neigh_parms_alloc() should be freed.

Fixes: 20e61da7ffcf ("ipv4: fail early when creating netdev named all or default")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netns: enable to inherit devconf from current netns

The goal is to be able to inherit the initial devconf parameters from the
current netns, ie the netns where this new netns has been created.

This is useful in a containers environment where /proc/sys is read only.
For example, if a pod is created with specifics devconf parameters and has
the capability to create netns, the user expects to get the same parameters
than his 'init_net', which is not the real init_net in this case.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

sysctl: pass kernel pointers to ->proc_handler

Instead of having all the sysctl handlers deal with user pointers, which
is rather hairy in terms of the BPF interaction, copy the input to and
from userspace in common code. This also means that the strings are
always NUL-terminated by the common code, making the API a little bit
safer.

As most handler just pass through the data to one of the common handlers
a lot of the changes are mechnical.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

net: ipv4: devinet: Fix crash when add/del multicast IP with autojoin

When CONFIG_IP_MULTICAST is not set and multicast ip is added to the device
with autojoin flag or when multicast ip is deleted kernel will crash.

steps to reproduce:

ip addr add 224.0.0.0/32 dev eth0
ip addr del 224.0.0.0/32 dev eth0

or

ip addr add 224.0.0.0/32 dev eth0 autojoin

Unable to handle kernel NULL pointer dereference at virtual address 0000000000000088
pc : _raw_write_lock_irqsave+0x1e0/0x2ac
lr : lock_sock_nested+0x1c/0x60
Call trace:
_raw_write_lock_irqsave+0x1e0/0x2ac
lock_sock_nested+0x1c/0x60
ip_mc_config.isra.28+0x50/0xe0
inet_rtm_deladdr+0x1a8/0x1f0
rtnetlink_rcv_msg+0x120/0x350
netlink_rcv_skb+0x58/0x120
rtnetlink_rcv+0x14/0x20
netlink_unicast+0x1b8/0x270
netlink_sendmsg+0x1a0/0x3b0
____sys_sendmsg+0x248/0x290
___sys_sendmsg+0x80/0xc0
__sys_sendmsg+0x68/0xc0
__arm64_sys_sendmsg+0x20/0x30
el0_svc_common.constprop.2+0x88/0x150
do_el0_svc+0x20/0x80
el0_sync_handler+0x118/0x190
el0_sync+0x140/0x180

Fixes: 93a714d6b53d ("multicast: Extend ip address command to enable multicast group join/leave on")
Signed-off-by: Taras Chornyi <taras.chornyi@plvision.eu>
Signed-off-by: Vadym Kochan <vadym.kochan@plvision.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>

inet: Use fallthrough;

Convert the various uses of fallthrough comments to fallthrough;

Done via script
Link: https://lore.kernel.org/lkml/b56602fcf79f849e733e7b521bb0e17895d390fa.1582230379.git.joe@perches.com/

And by hand:

net/ipv6/ip6_fib.c has a fallthrough comment outside of an #ifdef block
that causes gcc to emit a warning if converted in-place.

So move the new fallthrough; inside the containing #ifdef/#endif too.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

inet: protect against too small mtu values.

syzbot was once again able to crash a host by setting a very small mtu
on loopback device.

Let's make inetdev_valid_mtu() available in include/net/ip.h,
and use it in ip_setup_cork(), so that we protect both ip_append_page()
and __ip_append_data()

Also add a READ_ONCE() when the device mtu is read.

Pairs this lockless read with one WRITE_ONCE() in __dev_set_mtu(),
even if other code paths might write over this field.

Add a big comment in include/linux/netdevice.h about dev->mtu
needing READ_ONCE()/WRITE_ONCE() annotations.

Hopefully we will add the missing ones in followup patches.

[1]

refcount_t: saturated; leaking memory.
WARNING: CPU: 0 PID: 9464 at lib/refcount.c:22 refcount_warn_saturate+0x138/0x1f0 lib/refcount.c:22
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 9464 Comm: syz-executor850 Not tainted 5.4.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x197/0x210 lib/dump_stack.c:118
panic+0x2e3/0x75c kernel/panic.c:221
__warn.cold+0x2f/0x3e kernel/panic.c:582
report_bug+0x289/0x300 lib/bug.c:195
fixup_bug arch/x86/kernel/traps.c:174 [inline]
fixup_bug arch/x86/kernel/traps.c:169 [inline]
do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:267
do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:286
invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:refcount_warn_saturate+0x138/0x1f0 lib/refcount.c:22
Code: 06 31 ff 89 de e8 c8 f5 e6 fd 84 db 0f 85 6f ff ff ff e8 7b f4 e6 fd 48 c7 c7 e0 71 4f 88 c6 05 56 a6 a4 06 01 e8 c7 a8 b7 fd <0f> 0b e9 50 ff ff ff e8 5c f4 e6 fd 0f b6 1d 3d a6 a4 06 31 ff 89
RSP: 0018:ffff88809689f550 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff815e4336 RDI: ffffed1012d13e9c
RBP: ffff88809689f560 R08: ffff88809c50a3c0 R09: fffffbfff15d31b1
R10: fffffbfff15d31b0 R11: ffffffff8ae98d87 R12: 0000000000000001
R13: 0000000000040100 R14: ffff888099041104 R15: ffff888218d96e40
refcount_add include/linux/refcount.h:193 [inline]
skb_set_owner_w+0x2b6/0x410 net/core/sock.c:1999
sock_wmalloc+0xf1/0x120 net/core/sock.c:2096
ip_append_page+0x7ef/0x1190 net/ipv4/ip_output.c:1383
udp_sendpage+0x1c7/0x480 net/ipv4/udp.c:1276
inet_sendpage+0xdb/0x150 net/ipv4/af_inet.c:821
kernel_sendpage+0x92/0xf0 net/socket.c:3794
sock_sendpage+0x8b/0xc0 net/socket.c:936
pipe_to_sendpage+0x2da/0x3c0 fs/splice.c:458
splice_from_pipe_feed fs/splice.c:512 [inline]
__splice_from_pipe+0x3ee/0x7c0 fs/splice.c:636
splice_from_pipe+0x108/0x170 fs/splice.c:671
generic_splice_sendpage+0x3c/0x50 fs/splice.c:842
do_splice_from fs/splice.c:861 [inline]
direct_splice_actor+0x123/0x190 fs/splice.c:1035
splice_direct_to_actor+0x3b4/0xa30 fs/splice.c:990
do_splice_direct+0x1da/0x2a0 fs/splice.c:1078
do_sendfile+0x597/0xd00 fs/read_write.c:1464
__do_sys_sendfile64 fs/read_write.c:1525 [inline]
__se_sys_sendfile64 fs/read_write.c:1511 [inline]
__x64_sys_sendfile64+0x1dd/0x220 fs/read_write.c:1511
do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x441409
Code: e8 ac e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fffb64c4f78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441409
RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000005
RBP: 0000000000073b8a R08: 0000000000000010 R09: 0000000000000010
R10: 0000000000010001 R11: 0000000000000246 R12: 0000000000402180
R13: 0000000000402210 R14: 0000000000000000 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..

Fixes: 1470ddf7f8ce ("inet: Remove explicit write references to sk/inet in ip_append_data")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: don't set IPv6 only flags to IPv4 addresses

Avoid the situation where an IPV6 only flag is applied to an IPv4 address:

# ip addr add 192.0.2.1/24 dev dummy0 nodad home mngtmpaddr noprefixroute
# ip -4 addr show dev dummy0
2: dummy0: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000
inet 192.0.2.1/24 scope global noprefixroute dummy0
valid_lft forever preferred_lft forever

Or worse, by sending a malicious netlink command:

# ip -4 addr show dev dummy0
2: dummy0: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000
inet 192.0.2.1/24 scope global nodad optimistic dadfailed home tentative mngtmpaddr noprefixroute stable-privacy dummy0
valid_lft forever preferred_lft forever

Signed-off-by: Matteo Croce <mcroce@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ipv4: fix infinite loop on secondary addr promotion

secondary address promotion causes infinite loop -- it arranges
for ifa->ifa_next to point back to itself.

Problem is that 'prev_prom' and 'last_prim' might point at the same entry,
so 'last_sec' pointer must be obtained after prev_prom->next update.

Fixes: 2638eb8b50cf ("net: ipv4: provide __rcu annotation for ifa_list")
Reported-by: Ran Rozenstein <ranro@mellanox.com>
Reported-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: fix confirm_addr_indev() when enable route_localnet

When arp_ignore=3, the NIC won't reply for scope host addresses, but
if enable route_locanet, we need to reply ip address with head 127 and
scope RT_SCOPE_HOST.

Fixes: d0daebc3d622 ("ipv4: Add interface option to enable routing of 127.0.0.0/8")

Signed-off-by: Shijie Luo <luoshijie1@huawei.com>
Signed-off-by: Zhiqiang Liu <liuzhiqiang26@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: fix inet_select_addr() when enable route_localnet

Suppose we have two interfaces eth0 and eth1 in two hosts, follow
the same steps in the two hosts:
# sysctl -w net.ipv4.conf.eth1.route_localnet=1
# sysctl -w net.ipv4.conf.eth1.arp_announce=2
# ip route del 127.0.0.0/8 dev lo table local
and then set ip to eth1 in host1 like:
# ifconfig eth1 127.25.3.4/24
set ip to eth2 in host2 and ping host1:
# ifconfig eth1 127.25.3.14/24
# ping -I eth1 127.25.3.4
Well, host2 cannot connect to host1.

When set a ip address with head 127, the scope of the address defaults
to RT_SCOPE_HOST. In this situation, host2 will use arp_solicit() to
send a arp request for the mac address of host1 with ip
address 127.25.3.14. When arp_announce=2, inet_select_addr() cannot
select a correct saddr with condition ifa->ifa_scope > scope, because
ifa_scope is RT_SCOPE_HOST and scope is RT_SCOPE_LINK. Then,
inet_select_addr() will go to no_in_dev to lookup all interfaces to find
a primary ip and finally get the primary ip of eth0.

Here I add a localnet_scope defaults to RT_SCOPE_HOST, and when
route_localnet is enabled, this value changes to RT_SCOPE_LINK to make
inet_select_addr() find a correct primary ip as saddr of arp request.

Fixes: d0daebc3d622 ("ipv4: Add interface option to enable routing of 127.0.0.0/8")

Signed-off-by: Shijie Luo <luoshijie1@huawei.com>
Signed-off-by: Zhiqiang Liu <liuzhiqiang26@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ipv4: remove erroneous advancement of list pointer

Causes crash when lifetime expires on an adress as garbage is
dereferenced soon after.

This used to look like this:

for (ifap = &ifa->ifa_dev->ifa_list;
*ifap != NULL; ifap = &(*ifap)->ifa_next) {
if (*ifap == ifa) ...

but this was changed to:

struct in_ifaddr *tmp;

ifap = &ifa->ifa_dev->ifa_list;
tmp = rtnl_dereference(*ifap);
while (tmp) {
tmp = rtnl_dereference(tmp->ifa_next); // Bogus
if (rtnl_dereference(*ifap) == ifa) {
...
ifap = &tmp->ifa_next; // Can be NULL
tmp = rtnl_dereference(*ifap); // Dereference
}
}

Remove the bogus assigment/list entry skip.

Fixes: 2638eb8b50cf ("net: ipv4: provide __rcu annotation for ifa_list")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ipv4: fix rcu lockdep splat due to wrong annotation

syzbot triggered following splat when strict netlink
validation is enabled:

net/ipv4/devinet.c:1766 suspicious rcu_dereference_check() usage!

This occurs because we hold RTNL mutex, but no rcu read lock.
The second call site holds both, so just switch to the _rtnl variant.

Reported-by: syzbot+bad6e32808a3a97b1515@syzkaller.appspotmail.com
Fixes: 2638eb8b50cf ("net: ipv4: provide __rcu annotation for ifa_list")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ipv4: provide __rcu annotation for ifa_list

ifa_list is protected by rcu, yet code doesn't reflect this.

Add the __rcu annotations and fix up all places that are now reported by
sparse.

I've done this in the same commit to not add intermediate patches that
result in new warnings.

Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

devinet: use in_dev_for_each_ifa_rcu in more places

This also replaces spots that used for_primary_ifa().

for_primary_ifa() aborts the loop on the first secondary address seen.

Replace it with either the rcu or rtnl variant of in_dev_for_each_ifa(),
but two places will now also consider secondary addresses too:
inet_addr_onlink() and inet_ifa_byprefix().

I do not understand why they should ignore secondary addresses.

Why would a secondary address not be considered 'on link'?
When matching a prefix, why ignore a matching secondary address?

Other places get converted as well, but gain "->flags & SECONDARY" check.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: inetdevice: provide replacement iterators for in_ifaddr walk

The ifa_list is protected either by rcu or rtnl lock, but the
current iterators do not account for this.

This adds two iterators as replacement, a later patch in
the series will update them with the needed rcu/rtnl_dereference calls.

Its not done in this patch yet to avoid sparse warnings -- the fields
lack the proper __rcu annotation.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

netlink: make validation more configurable for future strictness

We currently have two levels of strict validation:

1) liberal (default)
- undefined (type >= max) & NLA_UNSPEC attributes accepted
- attribute length >= expected accepted
- garbage at end of message accepted
2) strict (opt-in)
- NLA_UNSPEC attributes accepted
- attribute length >= expected accepted

Split out parsing strictness into four different options:
* TRAILING - check that there's no trailing data after parsing
attributes (in message or nested)
* MAXTYPE - reject attrs > max known type
* UNSPEC - reject attributes with NLA_UNSPEC policy entries
* STRICT_ATTRS - strictly validate attribute size

The default for future things should be *everything*.
The current *_strict() is a combination of TRAILING and MAXTYPE,
and is renamed to _deprecated_strict().
The current regular parsing has none of this, and is renamed to
*_parse_deprecated().

Additionally it allows us to selectively set one of the new flags
even on old policies. Notably, the UNSPEC flag could be useful in
this case, since it can be arranged (by filling in the policy) to
not be an incompatible userspace ABI change, but would then going
forward prevent forgetting attribute entries. Similar can apply
to the POLICY flag.

We end up with the following renames:
* nla_parse -> nla_parse_deprecated
* nla_parse_strict -> nla_parse_deprecated_strict
* nlmsg_parse -> nlmsg_parse_deprecated
* nlmsg_parse_strict -> nlmsg_parse_deprecated_strict
* nla_parse_nested -> nla_parse_nested_deprecated
* nla_validate_nested -> nla_validate_nested_deprecated

Using spatch, of course:
@@
expression TB, MAX, HEAD, LEN, POL, EXT;
@@
-nla_parse(TB, MAX, HEAD, LEN, POL, EXT)
+nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT)

@@
expression NLH, HDRLEN, TB, MAX, POL, EXT;
@@
-nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT)
+nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT)

@@
expression NLH, HDRLEN, TB, MAX, POL, EXT;
@@
-nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT)
+nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT)

@@
expression TB, MAX, NLA, POL, EXT;
@@
-nla_parse_nested(TB, MAX, NLA, POL, EXT)
+nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT)

@@
expression START, MAX, POL, EXT;
@@
-nla_validate_nested(START, MAX, POL, EXT)
+nla_validate_nested_deprecated(START, MAX, POL, EXT)

@@
expression NLH, HDRLEN, MAX, POL, EXT;
@@
-nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT)
+nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT)

For this patch, don't actually add the strict, non-renamed versions
yet so that it breaks compile if I get it wrong.

Also, while at it, make nla_validate and nla_parse go down to a
common __nla_validate_parse() function to avoid code duplication.

Ultimately, this allows us to have very strict validation for every
new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the
next patch, while existing things will continue to work as is.

In effect then, this adds fully strict validation for any new command.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ignore sysctl_devconf_inherit_init_net without SYSCTL

When CONFIG_SYSCTL is turned off, we get a link failure for
the newly introduced tuning knob.

net/ipv6/addrconf.o: In function `addrconf_init_net':
addrconf.c:(.text+0x31dc): undefined reference to `sysctl_devconf_inherit_init_net'

Add an IS_ENABLED() check to fall back to the default behavior
(sysctl_devconf_inherit_init_net=0) here.

Fixes: 856c395cfa63 ("net: introduce a knob to control whether to inherit devconf config")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Christian Brauner <christian@brauner.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: introduce a knob to control whether to inherit devconf config

There have been many people complaining about the inconsistent
behaviors of IPv4 and IPv6 devconf when creating new network
namespaces. Currently, for IPv4, we inherit all current settings
from init_net, but for IPv6 we reset all setting to default.

This patch introduces a new /proc file
/proc/sys/net/core/devconf_inherit_init_net to control the
behavior of whether to inhert sysctl current settings from init_net.
This file itself is only available in init_net.

As demonstrated below:

Initial setup in init_net:
# cat /proc/sys/net/ipv4/conf/all/rp_filter
2
# cat /proc/sys/net/ipv6/conf/all/accept_dad
1

Default value 0 (current behavior):
# ip netns del test
# ip netns add test
# ip netns exec test cat /proc/sys/net/ipv4/conf/all/rp_filter
2
# ip netns exec test cat /proc/sys/net/ipv6/conf/all/accept_dad
0

Set to 1 (inherit from init_net):
# echo 1 > /proc/sys/net/core/devconf_inherit_init_net
# ip netns del test
# ip netns add test
# ip netns exec test cat /proc/sys/net/ipv4/conf/all/rp_filter
2
# ip netns exec test cat /proc/sys/net/ipv6/conf/all/accept_dad
1

Set to 2 (reset to default):
# echo 2 > /proc/sys/net/core/devconf_inherit_init_net
# ip netns del test
# ip netns add test
# ip netns exec test cat /proc/sys/net/ipv4/conf/all/rp_filter
0
# ip netns exec test cat /proc/sys/net/ipv6/conf/all/accept_dad
0

Set to a value out of range (invalid):
# echo 3 > /proc/sys/net/core/devconf_inherit_init_net
-bash: echo: write error: Invalid argument
# echo -1 > /proc/sys/net/core/devconf_inherit_init_net
-bash: echo: write error: Invalid argument

Reported-by: Zhu Yanjun <Yanjun.Zhu@windriver.com>
Reported-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ipv4: netconf: perform strict checks also for doit handlers

Make RTM_GETNETCONF's doit handler use strict checks when
NETLINK_F_STRICT_CHK is set.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netlink: fixup regression in RTM_GETADDR

This commit fixes a regression in AF_INET/RTM_GETADDR and
AF_INET6/RTM_GETADDR.

Before this commit, the kernel would stop dumping addresses once the first
skb was full and end the stream with NLMSG_DONE(-EMSGSIZE). The error
shouldn't be sent back to netlink_dump so the callback is kept alive. The
userspace is expected to call back with a new empty skb.

Changes from V1:
- The error is not handled in netlink_dump anymore but rather in
inet_dump_ifaddr and inet6_dump_addr directly as suggested by
David Ahern.

Fixes: d7e38611b81e ("net/ipv4: Put target net when address dump fails due to bad attributes")
Fixes: 242afaa6968c ("net/ipv6: Put target net when address dump fails due to bad attributes")

Cc: David Ahern <dsahern@gmail.com>
Cc: "David S . Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Signed-off-by: Arthur Gautier <baloo@gandi.net>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Allow class-e address assignment via ifconfig ioctl

While most distributions long ago switched to the iproute2 suite
of utilities, which allow class-e (240.0.0.0/4) address assignment,
distributions relying on busybox, toybox and other forms of
ifconfig cannot assign class-e addresses without this kernel patch.

While CIDR has been obsolete for 2 decades, and a survey of all the
open source code in the world shows the IN_whatever macros are also
obsolete... rather than obsolete CIDR from this ioctl entirely, this
patch merely enables class-e assignment, sanely.

Signed-off-by: Dave Taht <dave.taht@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: core: dev: Add extack argument to dev_change_flags()

In order to pass extack together with NETDEV_PRE_UP notifications, it's
necessary to route the extack to __dev_open() from diverse (possibly
indirect) callers. One prominent API through which the notification is
invoked is dev_change_flags().

Therefore extend dev_change_flags() with and extra extack argument and
update all users. Most of the calls end up just encoding NULL, but
several sites (VLAN, ipvlan, VRF, rtnetlink) do have extack available.

Since the function declaration line is changed anyway, name the other
function arguments to placate checkpatch.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/{ipv4,ipv6}: Do not put target net if input nsid is invalid

The cleanup path will put the target net when netnsid is set. So we must
reset netnsid if the input is invalid.

Fixes: d7e38611b81e ("net/ipv4: Put target net when address dump fails due to bad attributes")
Fixes: 242afaa6968c ("net/ipv6: Put target net when address dump fails due to bad attributes")
Cc: David Ahern <dsahern@gmail.com>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4: Put target net when address dump fails due to bad attributes

If tgt_net is set based on IFA_TARGET_NETNSID attribute in the dump
request, make sure all error paths call put_net.

Fixes: 5fcd266a9f64 ("net/ipv4: Add support for dumping addresses for a specific device")
Fixes: c33078e3dfb1 ("net/ipv4: Update inet_dump_ifaddr for strict data checking")
Reported-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4: Add support for dumping addresses for a specific device

If an RTM_GETADDR dump request has ifa_index set in the ifaddrmsg
header, then return only the addresses for that device.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4: Move loop over addresses on a device into in_dev_dump_addr

Similar to IPv6 move the logic that walks over the ipv4 address list
for a device into a helper.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Update netconf dump handlers for strict data checking

Update inet_netconf_dump_devconf, inet6_netconf_dump_devconf, and
mpls_netconf_dump_devconf for strict data checking. If the flag is set,
the dump request is expected to have an netconfmsg struct as the header.
The struct only has the family member and no attributes can be appended.

Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: Christian Brauner <christian@brauner.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4: Update inet_dump_ifaddr for strict data checking

Update inet_dump_ifaddr for strict data checking. If the flag is set,
the dump request is expected to have an ifaddrmsg struct as the header
potentially followed by one or more attributes. Any data passed in the
header or as an attribute is taken as a request to influence the data
returned. Only values supported by the dump handler are allowed to be
non-0 or set in the request. At the moment only the IFA_TARGET_NETNSID
attribute is supported. Follow on patches can support for other fields
(e.g., honor ifa_index and only return data for the given device index).

Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: Christian Brauner <christian@brauner.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Add extack to nlmsg_parse

Make sure extack is passed to nlmsg_parse where easy to do so.
Most of these are dump handlers and leveraging the extack in
the netlink_callback.

Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: Christian Brauner <christian@brauner.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: add inet_fill_args

inet_fill_ifaddr() already took 6 arguments which meant the 7th argument
would need to be pushed onto the stack on x86.
Add a new struct inet_fill_args which holds common information passed
to inet_fill_ifaddr() and shortens the function to three pointer arguments.

Signed-off-by: Christian Brauner <christian@brauner.io>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: enable IFA_TARGET_NETNSID for RTM_GETADDR

- Backwards Compatibility:
If userspace wants to determine whether ipv4 RTM_GETADDR requests
support the new IFA_TARGET_NETNSID property it should verify that the
reply includes the IFA_TARGET_NETNSID property. If it does not
userspace should assume that IFA_TARGET_NETNSID is not supported for
ipv4 RTM_GETADDR requests on this kernel.
- From what I gather from current userspace tools that make use of
RTM_GETADDR requests some of them pass down struct ifinfomsg when they
should actually pass down struct ifaddrmsg. To not break existing
tools that pass down the wrong struct we will do the same as for
RTM_GETLINK | NLM_F_DUMP requests and not error out when the
nlmsg_parse() fails.

- Security:
Callers must have CAP_NET_ADMIN in the owning user namespace of the
target network namespace.

Signed-off-by: Christian Brauner <christian@brauner.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

route: add support for directed broadcast forwarding

This patch implements the feature described in rfc1812#section-5.3.5.2
and rfc2644. It allows the router to forward directed broadcast when
sysctl bc_forwarding is enabled.

Note that this feature could be done by iptables -j TEE, but it would
cause some problems:
- target TEE's gateway param has to be set with a specific address,
and it's not flexible especially when the route wants forward all
directed broadcasts.
- this duplicates the directed broadcasts so this may cause side
effects to applications.

Besides, to keep consistent with other os router like BSD, it's also
necessary to implement it in the route rx path.

Note that route cache needs to be flushed when bc_forwarding is
changed.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4: Add support for specifying metric of connected routes

Add support for IFA_RT_PRIORITY to ipv4 addresses.

If the metric is changed on an existing address then the new route
is inserted before removing the old one. Since the metric is one
of the route keys, the prefix route can not be replaced.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Drop pernet_operations::async

Synchronous pernet_operations are not allowed anymore.
All are asynchronous. So, drop the structure member.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Convert pernet_subsys, registered from inet_init()

arp_net_ops just addr/removes /proc entry.

devinet_ops allocates and frees duplicate of init_net tables
and (un)registers sysctl entries.

fib_net_ops allocates and frees pernet tables, creates/destroys
netlink socket and (un)initializes /proc entries. Foreign
pernet_operations do not touch them.

ip_rt_proc_ops only modifies pernet /proc entries.

xfrm_net_ops creates/destroys /proc entries, allocates/frees
pernet statistics, hashes and tables, and (un)initializes
sysctl files. These are not touched by foreigh pernet_operations

xfrm4_net_ops allocates/frees private pernet memory, and
configures sysctls.

sysctl_route_ops creates/destroys sysctls.

rt_genid_ops only initializes fields of just allocated net.

ipv4_inetpeer_ops allocated/frees net private memory.

igmp_net_ops just creates/destroys /proc files and socket,
noone else interested in.

tcp_sk_ops seems to be safe, because tcp_sk_init() does not
depend on any other pernet_operations modifications. Iteration
over hash table in inet_twsk_purge() is made under RCU lock,
and it's safe to iterate the table this way. Removing from
the table happen from inet_twsk_deschedule_put(), but this
function is safe without any extern locks, as it's synchronized
inside itself. There are many examples, it's used in different
context. So, it's safe to leave tcp_sk_exit_batch() unlocked.

tcp_net_metrics_ops is synchronized on tcp_metrics_lock and safe.

udplite4_net_ops only creates/destroys pernet /proc file.

icmp_sk_ops creates percpu sockets, not touched by foreign
pernet_operations.

ipmr_net_ops creates/destroys pernet fib tables, (un)registers
fib rules and /proc files. This seem to be safe to execute
in parallel with foreign pernet_operations.

af_inet_ops just sets up default parameters of newly created net.

ipv4_mib_ops creates and destroys pernet percpu statistics.

raw_net_ops, tcp4_net_ops, udp4_net_ops, ping_v4_net_ops
and ip_proc_ops only create/destroy pernet /proc files.

ip4_frags_ops creates and destroys sysctl file.

So, it's safe to make the pernet_operations async.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Andrei Vagin <avagin@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: Get the address of interface correctly.

When using ioctl to get address of interface, we can't
get it anymore. For example, the command is show as below.

# ifconfig eth0

In the patch ("03aef17bb79b3"), the devinet_ioctl does not
return a suitable value, even though we can find it in
the kernel. Then fix it now.

Fixes: 03aef17bb79b3 ("devinet_ioctl(): take copyin/copyout to caller")
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

devinet_ioctl(): take copyin/copyout to caller

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

net: separate SIOCGIFCONF handling from dev_ioctl()

Only two of dev_ioctl() callers may pass SIOCGIFCONF to it.
Separating that codepath from the rest of dev_ioctl() allows both
to simplify dev_ioctl() itself (all other cases work with struct ifreq *)
*and* seriously simplify the compat side of that beast: all it takes
is passing to inet_gifconf() an extra argument - the size of individual
records (sizeof(struct ifreq) or sizeof(struct compat_ifreq)). With
dev_ifconf() called directly from sock_do_ioctl()/compat_dev_ifconf()
that's easy to arrange.

As the result, compat side of SIOCGIFCONF doesn't need any
allocations, copy_in_user() back and forth, etc.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

ipv4: igmp: guard against silly MTU values

IPv4 stack reacts to changes to small MTU, by disabling itself under
RTNL.

But there is a window where threads not using RTNL can see a wrong
device mtu. This can lead to surprises, in igmp code where it is
assumed the mtu is suitable.

Fix this by reading device mtu once and checking IPv4 minimal MTU.

This patch adds missing IPV4_MIN_MTU define, to not abuse
ETH_MIN_MTU anymore.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Add extack to validator_info structs used for address notifier

Add extack to in_validator_info and in6_validator_info. Update the one
user of each, ipvlan, to return an error message for failures.

Only manual configuration of an address is plumbed in the IPv6 code path.

Signed-off-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: mark expected switch fall-throughs

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Notice that in some cases I placed the "fall through" comment
on its own line, which is what GCC is expecting to find.

Addresses-Coverity-ID: 115108
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: core: rcu-ify rtnl af_ops

rtnl af_ops currently rely on rtnl mutex: unregister (called from module
exit functions) takes the rtnl mutex and all users that do af_ops lookup
also take the rtnl mutex. IOW, parallel rmmod will block until doit()
callback is done.

As none of the af_ops implementation sleep we can use rcu instead.

doit functions that need the af_ops can now use rcu instead of the
rtnl mutex provided the mutex isn't needed for other reasons.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: avoid a full fib lookup when rp_filter is disabled.

Since commit 1dced6a85482 ("ipv4: Restore accept_local behaviour
in fib_validate_source()") a full fib lookup is needed even if
the rp_filter is disabled, if accept_local is false - which is
the default.

What we really need in the above scenario is just checking
that the source IP address is not local, and in most case we
can do that is a cheaper way looking up the ifaddr hash table.

This commit adds a helper for such lookup, and uses it to
validate the src address when rp_filter is disabled and no
'local' routes are created by the user space in the relevant
namespace.

A new ipv4 netns flag is added to account for such routes.
We need that to preserve the same behavior we had before this
patch.

It also drops the checks to bail early from __fib_validate_source,
added by the commit 1dced6a85482 ("ipv4: Restore accept_local
behaviour in fib_validate_source()") they do not give any
measurable performance improvement: if we do the lookup with are
on a slower path.

This improves UDP performances for unconnected sockets
when rp_filter is disabled by 5% and also gives small but
measurable performance improvement for TCP flood scenarios.

v1 -> v2:
- use the ifaddr lookup helper in __ip_dev_find(), as suggested
by Eric
- fall-back to full lookup if custom local routes are present

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: make rtnl_register accept a flags parameter

This change allows us to later indicate to rtnetlink core that certain
doit functions should be called without acquiring rtnl_mutex.

This change should have no effect, we simply replace the last (now
unused) calcit argument with the new flag.

Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: convert in_device.refcnt from atomic_t to refcount_t

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Ipvlan should return an error when an address is already in use.

The ipvlan code already knows how to detect when a duplicate address is
about to be assigned to an ipvlan device. However, that failure is not
propogated outward and leads to a silent failure.

Introduce a validation step at ip address creation time and allow device
drivers to register to validate the incoming ip addresses. The ipvlan
code is the first consumer. If it detects an address in use, we can
return an error to the user before beginning to commit the new ifa in
the networking code.

This can be especially useful if it is necessary to provision many
ipvlans in containers. The provisioning software (or operator) can use
this to detect situations where an ip address is unexpectedly in use.

Signed-off-by: Krister Johansen <kjlx@templeofstupid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rtnetlink: plumb extended ack to doit function

Add netlink_ext_ack arg to rtnl_doit_func. Pass extack arg to nlmsg_parse
for doit functions that call it directly.

This is the first step to using extended error reporting in rtnetlink.
>From here individual subsystems can be updated to set netlink_ext_ack as
needed.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netlink: pass extended ACK struct to parsing functions

Pass the new extended ACK reporting struct to all of the generic
netlink parsing functions. For now, pass NULL in almost all callers
(except for some in the core.)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: devinet: Add support for RTM_DELNETCONF

Send RTM_DELNETCONF notifications when a device is deleted. The message only
needs the device index, so modify inet_netconf_fill_devconf to skip devconf
references if it is NULL.

Allows a userspace cache to remove entries as devices are deleted.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: devinet: Refactor inet_netconf_notify_devconf to take event

Refactor inet_netconf_notify_devconf to take the event as an input arg.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Eliminate duplicated codes by creating one new function in_dev_select_addr

There are two duplicated loops codes which used to select right
address in current codes. Now eliminate these codes by creating
one new function in_dev_select_addr.

Signed-off-by: Gao Feng <fgao@ikuai8.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h>

Fix up affected files that include this signal functionality via sched.h.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

net: ipv4: remove fib_lookup.h from devinet.c include list

nothing in devinet.c relies on fib_lookup.h; remove it from the includes

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Replace <asm/uaccess.h> with <linux/uaccess.h> globally

This was entirely automated, using the script by Al:

PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
$(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)

to do the replacement at the end of the merge window.

Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

netconf: add a notif when settings are created

All changes are notified, but the initial state was missing.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: do not abuse GFP_ATOMIC in inet_netconf_notify_devconf()

inet_forward_change() runs with RTNL held.
We are allowed to sleep if required.

If we use __in_dev_get_rtnl() instead of __in_dev_get_rcu(),
we no longer have to use GFP_ATOMIC allocations in
inet_netconf_notify_devconf(), meaning we are less likely to miss
notifications under memory pressure, and wont touch precious memory
reserves either and risk dropping incoming packets.

inet_netconf_get_devconf() can also use GFP_KERNEL allocation.

Fixes: edc9e748934c ("rtnl/ipv4: use netconf msg to advertise forwarding status")
Fixes: 9e5511106f99 ("rtnl/ipv4: add support of RTM_GETNETCONF")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: Don't do expensive useless work during inetdev destroy.

When an inetdev is destroyed, every address assigned to the interface
is removed. And in this scenerio we do two pointless things which can
be very expensive if the number of assigned interfaces is large:

1) Address promotion. We are deleting all addresses, so there is no
point in doing this.

2) A full nf conntrack table purge for every address. We only need to
do this once, as is already caught by the existing
masq_dev_notifier so masq_inet_event() can skip this.

Reported-by: Solar Designer <solar@openwall.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Tested-by: Cyrill Gorcunov <gorcunov@openvz.org>

netconf: add macro to represent all attributes

This patch adds macro NETCONFA_ALL to represent all type of netconf
attributes for IPv4 and IPv6.

Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: l3mdev: prefer VRF master for source address selection

When selecting an address in context of a VRF, the vrf master should be
preferred for address selection. If it isn't, the user has a hard time
getting the system to select to their preference - the code will pick
the address off the first in-VRF interface it can find, which on a
router could well be a non-routable address.

Signed-off-by: David Lamparter <equinox@diac24.net>
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
[dsa: Fixed comment style and removed extra blank link ]
Signed-off-by: David S. Miller <davem@davemloft.net>

net: l3mdev: address selection should only consider devices in L3 domain

David Lamparter noted a use case where the source address selection fails
to pick an address from a VRF interface - unnumbered interfaces.

Relevant commands from his script:
ip addr add 9.9.9.9/32 dev lo
ip link set lo up

ip link add name vrf0 type vrf table 101
ip rule add oif vrf0 table 101
ip rule add iif vrf0 table 101
ip link set vrf0 up
ip addr add 10.0.0.3/32 dev vrf0

ip link add name dummy2 type dummy
ip link set dummy2 master vrf0 up

--> note dummy2 has no address - unnumbered device

ip route add 10.2.2.2/32 dev dummy2 table 101
ip neigh add 10.2.2.2 dev dummy2 lladdr 02:00:00:00:00:02

tcpdump -ni dummy2 &

And using ping instead of his socat example:
$ ping -I vrf0 -c1 10.2.2.2
ping: Warning: source address might be selected on device other than vrf0.
PING 10.2.2.2 (10.2.2.2) from 9.9.9.9 vrf0: 56(84) bytes of data.

>From tcpdump:
12:57:29.449128 IP 9.9.9.9 > 10.2.2.2: ICMP echo request, id 2491, seq 1, length 64

Note the source address is from lo and is not a VRF local address. With
this patch:

$ ping -I vrf0 -c1 10.2.2.2
PING 10.2.2.2 (10.2.2.2) from 10.0.0.3 vrf0: 56(84) bytes of data.

>From tcpdump:
12:59:25.096426 IP 10.0.0.3 > 10.2.2.2: ICMP echo request, id 2113, seq 1, length 64

Now the source address comes from vrf0.

The ipv4 function for selecting source address takes a const argument.
Removing the const requires touching a lot of places, so instead
l3mdev_master_ifindex_rcu is changed to take a const argument and then
do the typecast to non-const as required by netdev_master_upper_dev_get_rcu.
This is similar to what l3mdev_fib_table_rcu does.

IPv6 for unnumbered interfaces appears to be selecting the addresses
properly.

Cc: David Lamparter <david@opensourcerouting.org>
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnl: RTM_GETNETCONF: fix wrong return value

An error response from a RTM_GETNETCONF request can return the positive
error value EINVAL in the struct nlmsgerr that can mislead userspace.

Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: add option to drop gratuitous ARP packets

In certain 802.11 wireless deployments, there will be ARP proxies
that use knowledge of the network to correctly answer requests.
To prevent gratuitous ARP frames on the shared medium from being
a problem, on such deployments wireless needs to drop them.

Enable this by providing an option called "drop_gratuitous_arp".

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: add option to drop unicast encapsulated in L2 multicast

In order to solve a problem with 802.11, the so-called hole-196 attack,
add an option (sysctl) called "drop_unicast_in_l2_multicast" which, if
enabled, causes the stack to drop IPv4 unicast packets encapsulated in
link-layer multi- or broadcast frames. Such frames can (as an attack)
be created by any member of the same wireless network and transmitted
as valid encrypted frames since the symmetric key for broadcast frames
is shared between all stations.

Additionally, enabling this option provides compliance with a SHOULD
clause of RFC 1122.

Reviewed-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netlink: Rightsize IFLA_AF_SPEC size calculation

if_nlmsg_size() overestimates the minimum allocation size of netlink
dump request (when called from rtnl_calcit()) or the size of the
message (when called from rtnl_getlink()). This is because
ext_filter_mask is not supported by rtnl_link_get_af_size() and
rtnl_link_get_size().

The over-estimation is significant when at least one netdev has many
VLANs configured (8 bytes for each configured VLAN).

This patch-set "rightsizes" the protocol specific attribute size
calculation by propagating ext_filter_mask to rtnl_link_get_af_size()
and adding this a argument to get_link_af_size op in rtnl_af_ops.

Bridge module already used filtering aware sizing for notifications.
br_get_link_af_size_filtered() is consistent with the modified
get_link_af_size op so it replaces br_get_link_af_size() in br_af_ops.
br_get_link_af_size() becomes unused and thus removed.

Signed-off-by: Ronen Arad <ronen.arad@intel.com>
Acked-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: RTEXT_FILTER_SKIP_STATS support to avoid dumping inet/inet6 stats

Many commonly used functions like getifaddrs() invoke RTM_GETLINK
to dump the interface information, and do not need the
the AF_INET6 statististics that are always returned by default
from rtnl_fill_ifinfo().

Computing the statistics can be an expensive operation that impacts
scaling, so it is desirable to avoid this if the information is
not needed.

This patch adds a the RTEXT_FILTER_SKIP_STATS extended info flag that
can be passed with netlink_request() to avoid statistics computation
for the ifinfo path.

Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4: suppress NETDEV_UP notification on address lifetime update

This notification causes the FIB to be updated, which is not needed
because the address already exists, and more importantly it may undo
intentional changes that were made to the FIB after the address was
originally added. (As a point of comparison, when an address becomes
deprecated because its preferred lifetime expired, a notification on
this chain is not generated.)

The motivation for this commit is fixing an incompatibility between
DHCP clients which set and update the address lifetime according to
the lease, and a commercial VPN client which replaces kernel routes
in a way that outbound traffic is sent only through the tunnel (and
disconnects if any further route changes are detected via netlink).

Signed-off-by: David Ward <david.ward@ll.mit.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: add support for linkdown sysctl to netconf

This kernel patch exports the value of the new
ignore_routes_with_linkdown via netconf.

v2: changes to notify userspace via netlink when sysctl values change
and proposed for 'net' since this could be considered a bugfix

Signed-off-by: Andy Gospodarek <gospo@cumulusnetworks.com>
Suggested-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ipv4 sysctl option to ignore routes when nexthop link is down

This feature is only enabled with the new per-interface or ipv4 global
sysctls called 'ignore_routes_with_linkdown'.

net.ipv4.conf.all.ignore_routes_with_linkdown = 0
net.ipv4.conf.default.ignore_routes_with_linkdown = 0
net.ipv4.conf.lo.ignore_routes_with_linkdown = 0
...

When the above sysctls are set, will report to userspace that a route is
dead and will no longer resolve to this nexthop when performing a fib
lookup. This will signal to userspace that the route will not be
selected. The signalling of a RTNH_F_DEAD is only passed to userspace
if the sysctl is enabled and link is down. This was done as without it
the netlink listeners would have no idea whether or not a nexthop would
be selected. The kernel only sets RTNH_F_DEAD internally if the
interface has IFF_UP cleared.

With the new sysctl set, the following behavior can be observed
(interface p8p1 is link-down):

default via 10.0.5.2 dev p9p1
10.0.5.0/24 dev p9p1 proto kernel scope link src 10.0.5.15
70.0.0.0/24 dev p7p1 proto kernel scope link src 70.0.0.1
80.0.0.0/24 dev p8p1 proto kernel scope link src 80.0.0.1 dead linkdown
90.0.0.0/24 via 80.0.0.2 dev p8p1 metric 1 dead linkdown
90.0.0.0/24 via 70.0.0.2 dev p7p1 metric 2
90.0.0.1 via 70.0.0.2 dev p7p1 src 70.0.0.1
cache
local 80.0.0.1 dev lo src 80.0.0.1
cache <local>
80.0.0.2 via 10.0.5.2 dev p9p1 src 10.0.5.15
cache

While the route does remain in the table (so it can be modified if
needed rather than being wiped away as it would be if IFF_UP was
cleared), the proper next-hop is chosen automatically when the link is
down. Now interface p8p1 is linked-up:

default via 10.0.5.2 dev p9p1
10.0.5.0/24 dev p9p1 proto kernel scope link src 10.0.5.15
70.0.0.0/24 dev p7p1 proto kernel scope link src 70.0.0.1
80.0.0.0/24 dev p8p1 proto kernel scope link src 80.0.0.1
90.0.0.0/24 via 80.0.0.2 dev p8p1 metric 1
90.0.0.0/24 via 70.0.0.2 dev p7p1 metric 2
192.168.56.0/24 dev p2p1 proto kernel scope link src 192.168.56.2
90.0.0.1 via 80.0.0.2 dev p8p1 src 80.0.0.1
cache
local 80.0.0.1 dev lo src 80.0.0.1
cache <local>
80.0.0.2 dev p8p1 src 80.0.0.1
cache

and the output changes to what one would expect.

If the sysctl is not set, the following output would be expected when
p8p1 is down:

default via 10.0.5.2 dev p9p1
10.0.5.0/24 dev p9p1 proto kernel scope link src 10.0.5.15
70.0.0.0/24 dev p7p1 proto kernel scope link src 70.0.0.1
80.0.0.0/24 dev p8p1 proto kernel scope link src 80.0.0.1 linkdown
90.0.0.0/24 via 80.0.0.2 dev p8p1 metric 1 linkdown
90.0.0.0/24 via 70.0.0.2 dev p7p1 metric 2

Since the dead flag does not appear, there should be no expectation that
the kernel would skip using this route due to link being down.

v2: Split kernel changes into 2 patches, this actually makes a
behavioral change if the sysctl is set. Also took suggestion from Alex
to simplify code by only checking sysctl during fib lookup and
suggestion from Scott to add a per-interface sysctl.

v3: Code clean-ups to make it more readable and efficient as well as a
reverse path check fix.

v4: Drop binary sysctl

v5: Whitespace fixups from Dave

v6: Style changes from Dave and checkpatch suggestions

v7: One more checkpatch fixup

Signed-off-by: Andy Gospodarek <gospo@cumulusnetworks.com>
Signed-off-by: Dinesh Dutt <ddutt@cumulusnetworks.com>
Acked-by: Scott Feldman <sfeldma@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: coding style: comparison for inequality with NULL

The ipv4 code uses a mixture of coding styles. In some instances check
for non-NULL pointer is done as x != NULL and sometimes as x. x is
preferred according to checkpatch and this patch makes the code
consistent by adopting the latter form.

No changes detected by objdiff.

Signed-off-by: Ian Morris <ipm@chirality.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: coding style: comparison for equality with NULL

The ipv4 code uses a mixture of coding styles. In some instances check
for NULL pointer is done as x == NULL and sometimes as !x. !x is
preferred according to checkpatch and this patch makes the code
consistent by adopting the latter form.

No changes detected by objdiff.

Signed-off-by: Ian Morris <ipm@chirality.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

netlink: implement nla_get_in_addr and nla_get_in6_addr

Those are counterparts to nla_put_in_addr and nla_put_in6_addr.

Signed-off-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netlink: implement nla_put_in_addr and nla_put_in6_addr

IP addresses are often stored in netlink attributes. Add generic functions
to do that.

For nla_put_in_addr, it would be nicer to pass struct in_addr but this is
not used universally throughout the kernel, in way too many places __be32 is
used to store IPv4 address.

Signed-off-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4, ipv6: kill ip_mc_{join, leave}_group and ipv6_sock_mc_{join, drop}

in favor of their inner __ ones, which doesn't grab rtnl.

As these functions need to operate on a locked socket, we can't be
grabbing rtnl by then. It's too late and doing so causes reversed
locking.

So this patch:
- move rtnl handling to callers instead while already fixing some
reversed locking situations, like on vxlan and ipvs code.
- renames __ ones to not have the __ mark:
__ip_mc_{join,leave}_group -> ip_mc_{join,leave}_group
__ipv6_sock_mc_{join,drop} -> ipv6_sock_mc_{join,drop}

Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

netns: constify net_hash_mix() and various callers

const qualifiers ease code review by making clear
which objects are not written in a function.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

multicast: Extend ip address command to enable multicast group join/leave on

Joining multicast group on ethernet level via "ip maddr" command would
not work if we have an Ethernet switch that does igmp snooping since
the switch would not replicate multicast packets on ports that did not
have IGMP reports for the multicast addresses.

Linux vxlan interfaces created via "ip link add vxlan" have the group option
that enables then to do the required join.

By extending ip address command with option "autojoin" we can get similar
functionality for openvswitch vxlan interfaces as well as other tunneling
mechanisms that need to receive multicast traffic. The kernel code is
structured similar to how the vxlan driver does a group join / leave.

example:
ip address add 224.1.1.10/24 dev eth5 autojoin
ip address del 224.1.1.10/24 dev eth5

Signed-off-by: Madhu Challa <challa@noironetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: spelling fixes

Spelling errors caught by codespell.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: mark some potential candidates __read_mostly

They are all either written once or extremly rarely (e.g. from init
code), so we can move them to the .data..read_mostly section.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netlink: Fix bugs in nlmsg_end() conversions.

Commit 053c095a82cf ("netlink: make nlmsg_end() and genlmsg_end()
void") didn't catch all of the cases where callers were breaking out
on the return value being equal to zero, which they no longer should
when zero means success.

Fix all such cases.

Reported-by: Marcel Holtmann <marcel@holtmann.org>
Reported-by: Scott Feldman <sfeldma@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netlink: make nlmsg_end() and genlmsg_end() void

Contrary to common expectations for an "int" return, these functions
return only a positive value -- if used correctly they cannot even
return 0 because the message header will necessarily be in the skb.

This makes the very common pattern of

if (genlmsg_end(...) < 0) { ... }

be a whole bunch of dead code. Many places also simply do

return nlmsg_end(...);

and the caller is expected to deal with it.

This also commonly (at least for me) causes errors, because it is very
common to write

if (my_function(...))
/* error condition */

and if my_function() does "return nlmsg_end()" this is of course wrong.

Additionally, there's not a single place in the kernel that actually
needs the message length returned, and if anyone needs it later then
it'll be very easy to just use skb->len there.

Remove this, and make the functions void. This removes a bunch of dead
code as described above. The patch adds lines because I did

- return nlmsg_end(...);
+ nlmsg_end(...);
+ return 0;

I could have preserved all the function's return values by returning
skb->len, but instead I've audited all the places calling the affected
functions and found that none cared. A few places actually compared
the return value with <= 0 in dump functionality, but that could just
be changed to < 0 with no change in behaviour, so I opted for the more
efficient version.

One instance of the error I've made numerous times now is also present
in net/phonet/pn_netlink.c in the route_dumpit() function - it didn't
check for <0 or <=0 and thus broke out of the loop every single time.
I've preserved this since it will (I think) have caused the messages to
userspace to be formatted differently with just a single message for
every SKB returned to userspace. It's possible that this isn't needed
for the tools that actually use this, but I don't even know what they
are so couldn't test that changing this behaviour would be acceptable.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: fail early when creating netdev named all or default

We create a proc dir for each network device, this will cause
conflicts when the devices have name "all" or "default".

Rather than emitting an ugly kernel warning, we could just
fail earlier by checking the device name.

Reported-by: Stephane Chazelas <stephane.chazelas@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: minor spelling fix

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: remove inet_addr_hash_lock in devinet.c

All the callers hold RTNL lock, so there is no need to use inet_addr_hash_lock
to protect the hash list.

Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: Fix runtime WARNING in rtmsg_ifa()

On m68k/ARAnyM:

WARNING: CPU: 0 PID: 407 at net/ipv4/devinet.c:1599 0x316a99()
Modules linked in:
CPU: 0 PID: 407 Comm: ifconfig Not tainted
3.13.0-atari-09263-g0c71d68014d1 #1378
Stack from 10c4fdf0:
10c4fdf0 002ffabb 000243e8 00000000 008ced6c 00024416 00316a99 0000063f
00316a99 00000009 00000000 002501b4 00316a99 0000063f c0a86117 00000080
c0a86117 00ad0c90 00250a5a 00000014 00ad0c90 00000000 00000000 00000001
00b02dd0 00356594 00000000 00356594 c0a86117 eff6c9e4 008ced6c 00000002
008ced60 0024f9b4 00250b52 00ad0c90 00000000 00000000 00252390 00ad0c90
eff6c9e4 0000004f 00000000 00000000 eff6c9e4 8000e25c eff6c9e4 80001020
Call Trace: [<000243e8>] warn_slowpath_common+0x52/0x6c
[<00024416>] warn_slowpath_null+0x14/0x1a
[<002501b4>] rtmsg_ifa+0xdc/0xf0
[<00250a5a>] __inet_insert_ifa+0xd6/0x1c2
[<0024f9b4>] inet_abc_len+0x0/0x42
[<00250b52>] inet_insert_ifa+0xc/0x12
[<00252390>] devinet_ioctl+0x2ae/0x5d6

Adding some debugging code reveals that net_fill_ifaddr() fails in

put_cacheinfo(skb, ifa->ifa_cstamp, ifa->ifa_tstamp,
preferred, valid))

nla_put complains:

lib/nlattr.c:454: skb_tailroom(skb) = 12, nla_total_size(attrlen) = 20

Apparently commit 5c766d642bcaffd0c2a5b354db2068515b3846cf ("ipv4:
introduce address lifetime") forgot to take into account the addition of
struct ifa_cacheinfo in inet_nlmsg_size(). Hence add it, like is already
done for ipv6.

Suggested-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4: queue work on power efficient wq

Workqueue used in ipv4 layer have no real dependency of scheduling these on the
cpu which scheduled them.

On a idle system, it is observed that an idle cpu wakes up many times just to
service this work. It would be better if we can schedule it on a cpu which the
scheduler believes to be the most appropriate one.

This patch replaces normal workqueues with power efficient versions. This
doesn't change existing behavior of code unless CONFIG_WQ_POWER_EFFICIENT is
enabled.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: replace macros net_random and net_srandom with direct calls to prandom

This patch removes the net_random and net_srandom macros and replaces
them with direct calls to the prandom ones. As new commits only seem to
use prandom_u32 there is no use to keep them around.
This change makes it easier to grep for users of prandom_u32.

Signed-off-by: Aruna-Hewapathirane <aruna.hewapathirane@gmail.com>
Suggested-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: loopback device: ignore value changes after device is upped

When lo is brought up, new ifa is created. Then, devconf and neigh values
bitfield should be set so later changes of default values would not
affect lo values.

Note that the same behaviour is in ipv6. Also note that this is likely
not an issue in many distros (for example Fedora 19) because userspace
sets address to lo manually before bringing it up.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>

netconf: rename PROXY_ARP to NEIGH_PROXY

Use same field for both IPv4 (proxy_arp) and IPv6 (proxy_ndp)
so fix it before API is set to be a common name

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netconf: add proxy-arp support

Add support to netconf to show changes to proxy-arp status on a per
interface basis via netlink in a manner similar to forwarding
and reverse path state.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: fix wildcard search with inet_confirm_addr()

Help of this function says: "in_dev: only on this interface, 0=any interface",
but since commit 39a6d0630012 ("[NETNS]: Process inet_confirm_addr in the
correct namespace."), the code supposes that it will never be NULL. This
function is never called with in_dev == NULL, but it's exported and may be used
by an external module.

Because this patch restore the ability to call inet_confirm_addr() with in_dev
== NULL, I partially revert the above commit, as suggested by Julian.

CC: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: add support for IFA_FLAGS nl attribute

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>

neigh: restore old behaviour of default parms values

Previously inet devices were only constructed when addresses are added.
Therefore the default neigh parms values they get are the ones at the
time of these operations.

Now that we're creating inet devices earlier, this changes the behaviour
of default neigh parms values in an incompatible way (see bug #8519).

This patch creates a compromise by setting the default values at the
same point as before but only for those that have not been explicitly
set by the user since the inet device's creation.

Introduced by:
commit 8030f54499925d073a88c09f30d5d844fb1b3190
Author: Herbert Xu <herbert@gondor.apana.org.au>
Date: Thu Feb 22 01:53:47 2007 +0900

[IPV4] devinet: Register inetdev earlier.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>

neigh: use tbl->family to distinguish ipv4 from ipv6

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: igmp: Allow user-space configuration of igmp unsolicited report interval

Adds the new procfs knobs:

/proc/sys/net/ipv4/conf/*/igmpv2_unsolicited_report_interval
/proc/sys/net/ipv4/conf/*/igmpv3_unsolicited_report_interval

Which will allow userspace configuration of the IGMP unsolicited report
interval (see below) in milliseconds. The defaults are 10000ms for IGMPv2
and 1000ms for IGMPv3 in accordance with RFC2236 and RFC3376.

Background:

If an IGMP join packet is lost you will not receive data sent to the
multicast group so if no data arrives from that multicast group in a
period of time after the IGMP join a second IGMP join will be sent. The
delay between joins is the "IGMP Unsolicited Report Interval".

Prior to this patch this value was hard coded in the kernel to 10s for
IGMPv2 and 1s for IGMPv3. 10s is unsuitable for some use-cases, such as
IPTV as it can cause channel change to be slow in the presence of packet
loss.

This patch allows the value to be overridden from userspace for both
IGMPv2 and IGMPv3 such that it can be tuned accoding to the network.

Tested with Wireshark and a simple program to join a (non-existent)
multicast group. The distribution of timings for the second join differ
based upon setting the procfs knobs.

igmpvX_unsolicited_report_interval is intended to follow the pattern
established by force_igmp_version, and while a procfs entry has been added
a corresponding sysctl knob has not as it is my understanding that sysctl
is deprecated[1].

[1]: http://lwn.net/Articles/247243/

Signed-off-by: William Manley <william.manley@youview.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: igmp: Don't flush routing cache when force_igmp_version is modified

The procfs knob /proc/sys/net/ipv4/conf/*/force_igmp_version allows the
IGMP protocol version to use to be explicitly set. As a side effect this
caused the routing cache to be flushed as it was declared as a
DEVINET_SYSCTL_FLUSHING_ENTRY. Flushing is unnecessary and this patch
makes it so flushing does not occur.

Requested by Hannes Frederic Sowa as he was reviewing other patches
adding procfs entries.

Suggested-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: William Manley <william.manley@youview.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rtm_to_ifaddr: free ifa if ifa_cacheinfo processing fails

Commit 5c766d642 ("ipv4: introduce address lifetime") leaves the ifa
resource that was allocated via inet_alloc_ifa() unfreed when returning
the function with -EINVAL. Thus, free it first via inet_free_ifa().

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Reviewed-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: remove an unneeded check

"ifa->ifa_label" is an array inside the in_ifaddr struct. It can never
be NULL so we can remove this check.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Convert uses of typedef ctl_table to struct ctl_table

Reduce the uses of this unnecessary typedef.

Done via perl script:

$ git grep --name-only -w ctl_table net | \
xargs perl -p -i -e '\
sub trim { my ($local) = @_; $local =~ s/(^\s+|\s+$)//g; return $local; } \
s/\b(?<!struct\s)ctl_table\b(\s*\*\s*|\s+\w+)/"struct ctl_table " . trim($1)/ge'

Reflow the modified lines that now exceed 80 columns.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

igmp: hash a hash table to speedup ip_check_mc_rcu()

After IP route cache removal, multicast applications using
a lot of multicast addresses hit a O(N) behavior in ip_check_mc_rcu()

Add a per in_device hash table to get faster lookup.

This hash table is created only if the number of items in mc_list is
above 4.

Reported-by: Shawn Bohrer <sbohrer@rgmadvisors.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Tested-by: Shawn Bohrer <sbohrer@rgmadvisors.com>
Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: pass info struct via netdevice notifier

So far, only net_device * could be passed along with netdevice notifier
event. This patch provides a possibility to pass custom structure
able to provide info that event listener needs to know.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>

v2->v3: fix typo on simeth
shortened dev_getter
shortened notifier_info struct name
v1->v2: fix notifier_call parameter in call_netdevice_notifier()
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ipv4: fix schedule while atomic bug in check_lifetime()

move might_sleep operations out of the rcu_read_lock() section.
Also fix iterating over ifa_dev->ifa_list

Introduced by: commit 5c766d642bcaf "ipv4: introduce address lifetime"

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ipv4: reset check_lifetime_work after changing lifetime

This will result in calling check_lifetime in nearest opportunity and
that function will adjust next time to call check_lifetime correctly.
Without this, check_lifetime is called in time computed by previous run,
not affecting modified lifetime.

Introduced by: commit 5c766d642bcaf "ipv4: introduce address lifetime"

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ipv4: notify when address lifetime changes

if userspace changes lifetime of address, send netlink notification and
call notifier.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: provide addr and netconf dump consistency info

This patch takes benefit of dev_addr_genid and dev_base_seq to check if a change
occurs during a netlink dump. If a change is detected, the flag NLM_F_DUMP_INTR
is set in the first message after the dump was interrupted.

Note that seq and prev_seq must be reset between each family in rtnl_dump_all()
because they are specific to each family.

Reported-by: Junwei Zhang <junwei.zhang@6wind.com>
Reported-by: Hongjun Li <hongjun.li@6wind.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: Remove passing of attributes into rtnl_doit functions

With decnet converted, we can finally get rid of rta_buf and its
computations around it. It also gets rid of the minimal header
length verification since all message handlers do that explicitly
anyway.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

netconf: add the handler to dump entries

It's useful to be able to get the initial state of all entries. The patch adds
the support for IPv4 and IPv6.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

hlist: drop the node parameter from iterators

I'm not sure why, but the hlist for each entry iterators were conceived

list_for_each_entry(pos, head, member)

The hlist ones were greedy and wanted an extra parameter:

hlist_for_each_entry(tpos, pos, head, member)

Why did they need an extra pos parameter? I'm not quite sure. Not only
they don't really need it, it also prevents the iterator from looking
exactly like the list iterator, which is unfortunate.

Besides the semantic patch, there was some manual work required:

- Fix up the actual hlist iterators in linux/list.h
- Fix up the declaration of other iterators based on the hlist ones.
- A very small amount of places were using the 'node' parameter, this
was modified to use 'obj->member' instead.
- Coccinelle didn't handle the hlist_for_each_entry_safe iterator
properly, so those had to be fixed up manually.

The semantic patch which is mostly the work of Peter Senna Tschudin is here:

@@
iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;

type T;
expression a,c,d,e;
identifier b;
statement S;
@@

-T b;
<+... when != b
(
hlist_for_each_entry(a,
- b,
c, d) S
|
hlist_for_each_entry_continue(a,
- b,
c) S
|
hlist_for_each_entry_from(a,
- b,
c) S
|
hlist_for_each_entry_rcu(a,
- b,
c, d) S
|
hlist_for_each_entry_rcu_bh(a,
- b,
c, d) S
|
hlist_for_each_entry_continue_rcu_bh(a,
- b,
c) S
|
for_each_busy_worker(a, c,
- b,
d) S
|
ax25_uid_for_each(a,
- b,
c) S
|
ax25_for_each(a,
- b,
c) S
|
inet_bind_bucket_for_each(a,
- b,
c) S
|
sctp_for_each_hentry(a,
- b,
c) S
|
sk_for_each(a,
- b,
c) S
|
sk_for_each_rcu(a,
- b,
c) S
|
sk_for_each_from
-(a, b)
+(a)
S
+ sk_for_each_from(a) S
|
sk_for_each_safe(a,
- b,
c, d) S
|
sk_for_each_bound(a,
- b,
c) S
|
hlist_for_each_entry_safe(a,
- b,
c, d, e) S
|
hlist_for_each_entry_continue_rcu(a,
- b,
c) S
|
nr_neigh_for_each(a,
- b,
c) S
|
nr_neigh_for_each_safe(a,
- b,
c, d) S
|
nr_node_for_each(a,
- b,
c) S
|
nr_node_for_each_safe(a,
- b,
c, d) S
|
- for_each_gfn_sp(a, c, d, b) S
+ for_each_gfn_sp(a, c, d) S
|
- for_each_gfn_indirect_valid_sp(a, c, d, b) S
+ for_each_gfn_indirect_valid_sp(a, c, d) S
|
for_each_host(a,
- b,
c) S
|
for_each_host_safe(a,
- b,
c, d) S
|
for_each_mesh_entry(a,
- b,
c, d) S
)
...+>

[akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
[akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
[akpm@linux-foundation.org: checkpatch fixes]
[akpm@linux-foundation.org: fix warnings]
[akpm@linux-foudnation.org: redo intrusive kvm changes]
Tested-by: Peter Senna Tschudin <peter.senna@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ipv4: introduce address lifetime

There are some usecase when lifetime of ipv4 addresses might be helpful.
For example:
1) initramfs networkmanager uses a DHCP daemon to learn network
configuration parameters
2) initramfs networkmanager addresses, routes and DNS configuration
3) initramfs networkmanager is requested to stop
4) initramfs networkmanager stops all daemons including dhclient
5) there are addresses and routes configured but no daemon running. If
the system doesn't start networkmanager for some reason, addresses and
routes will be used forever, which violates RFC 2131.

This patch is essentially a backport of ivp6 address lifetime mechanism
for ipv4 addresses.

Current "ip" tool supports this without any patch (since it does not
distinguish between ipv4 and ipv6 addresses in this perspective.

Also, this should be back-compatible with all current netlink users.

Reported-by: Pavel Šimerda <psimerda@redhat.com>
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: fix NULL checking in devinet_ioctl()

The NULL pointer check `!ifa' should come before its first use.

[ Bug origin : commit fd23c3b31107e2fc483301ee923d8a1db14e53f4
(ipv4: Add hash table of interface addresses) in linux-2.6.39 ]

Signed-off-by: Xi Wang <xi.wang@gmail.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netconf: advertise mc_forwarding status

This patch advertise the MC_FORWARDING status for IPv4 and IPv6.
This field is readonly, only multicast engine in the kernel updates it.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Enable a userns root rtnl calls that are safe for unprivilged users

- Only allow moving network devices to network namespaces you have
CAP_NET_ADMIN privileges over.

- Enable creating/deleting/modifying interfaces
- Enable adding/deleting addresses
- Enable adding/setting/deleting neighbour entries
- Enable adding/removing routes
- Enable adding/removing fib rules
- Enable setting the forwarding state
- Enable adding/removing ipv6 address labels
- Enable setting bridge parameter

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Enable some sysctls that are safe for the userns root

- Enable the per device ipv4 sysctls:
net/ipv4/conf/<if>/forwarding
net/ipv4/conf/<if>/mc_forwarding
net/ipv4/conf/<if>/accept_redirects
net/ipv4/conf/<if>/secure_redirects
net/ipv4/conf/<if>/shared_media
net/ipv4/conf/<if>/rp_filter
net/ipv4/conf/<if>/send_redirects
net/ipv4/conf/<if>/accept_source_route
net/ipv4/conf/<if>/accept_local
net/ipv4/conf/<if>/src_valid_mark
net/ipv4/conf/<if>/proxy_arp
net/ipv4/conf/<if>/medium_id
net/ipv4/conf/<if>/bootp_relay
net/ipv4/conf/<if>/log_martians
net/ipv4/conf/<if>/tag
net/ipv4/conf/<if>/arp_filter
net/ipv4/conf/<if>/arp_announce
net/ipv4/conf/<if>/arp_ignore
net/ipv4/conf/<if>/arp_accept
net/ipv4/conf/<if>/arp_notify
net/ipv4/conf/<if>/proxy_arp_pvlan
net/ipv4/conf/<if>/disable_xfrm
net/ipv4/conf/<if>/disable_policy
net/ipv4/conf/<if>/force_igmp_version
net/ipv4/conf/<if>/promote_secondaries
net/ipv4/conf/<if>/route_localnet

- Enable the global ipv4 sysctl:
net/ipv4/ip_forward

- Enable the per device ipv6 sysctls:
net/ipv6/conf/<if>/forwarding
net/ipv6/conf/<if>/hop_limit
net/ipv6/conf/<if>/mtu
net/ipv6/conf/<if>/accept_ra
net/ipv6/conf/<if>/accept_redirects
net/ipv6/conf/<if>/autoconf
net/ipv6/conf/<if>/dad_transmits
net/ipv6/conf/<if>/router_solicitations
net/ipv6/conf/<if>/router_solicitation_interval
net/ipv6/conf/<if>/router_solicitation_delay
net/ipv6/conf/<if>/force_mld_version
net/ipv6/conf/<if>/use_tempaddr
net/ipv6/conf/<if>/temp_valid_lft
net/ipv6/conf/<if>/temp_prefered_lft
net/ipv6/conf/<if>/regen_max_retry
net/ipv6/conf/<if>/max_desync_factor
net/ipv6/conf/<if>/max_addresses
net/ipv6/conf/<if>/accept_ra_defrtr
net/ipv6/conf/<if>/accept_ra_pinfo
net/ipv6/conf/<if>/accept_ra_rtr_pref
net/ipv6/conf/<if>/router_probe_interval
net/ipv6/conf/<if>/accept_ra_rt_info_max_plen
net/ipv6/conf/<if>/proxy_ndp
net/ipv6/conf/<if>/accept_source_route
net/ipv6/conf/<if>/optimistic_dad
net/ipv6/conf/<if>/mc_forwarding
net/ipv6/conf/<if>/disable_ipv6
net/ipv6/conf/<if>/accept_dad
net/ipv6/conf/<if>/force_tllao

- Enable the global ipv6 sysctls:
net/ipv6/bindv6only
net/ipv6/icmp/ratelimit

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Allow userns root to control ipv4

Allow an unpriviled user who has created a user namespace, and then
created a network namespace to effectively use the new network
namespace, by reducing capable(CAP_NET_ADMIN) and
capable(CAP_NET_RAW) calls to be ns_capable(net->user_ns,
CAP_NET_ADMIN), or capable(net->user_ns, CAP_NET_RAW) calls.

Settings that merely control a single network device are allowed.
Either the network device is a logical network device where
restrictions make no difference or the network device is hardware NIC
that has been explicity moved from the initial network namespace.

In general policy and network stack state changes are allowed
while resource control is left unchanged.

Allow creating raw sockets.
Allow the SIOCSARP ioctl to control the arp cache.
Allow the SIOCSIFFLAG ioctl to allow setting network device flags.
Allow the SIOCSIFADDR ioctl to allow setting a netdevice ipv4 address.
Allow the SIOCSIFBRDADDR ioctl to allow setting a netdevice ipv4 broadcast address.
Allow the SIOCSIFDSTADDR ioctl to allow setting a netdevice ipv4 destination address.
Allow the SIOCSIFNETMASK ioctl to allow setting a netdevice ipv4 netmask.
Allow the SIOCADDRT and SIOCDELRT ioctls to allow adding and deleting ipv4 routes.

Allow the SIOCADDTUNNEL, SIOCCHGTUNNEL and SIOCDELTUNNEL ioctls for
adding, changing and deleting gre tunnels.

Allow the SIOCADDTUNNEL, SIOCCHGTUNNEL and SIOCDELTUNNEL ioctls for
adding, changing and deleting ipip tunnels.

Allow the SIOCADDTUNNEL, SIOCCHGTUNNEL and SIOCDELTUNNEL ioctls for
adding, changing and deleting ipsec virtual tunnel interfaces.

Allow setting the MRT_INIT, MRT_DONE, MRT_ADD_VIF, MRT_DEL_VIF, MRT_ADD_MFC,
MRT_DEL_MFC, MRT_ASSERT, MRT_PIM, MRT_TABLE socket options on multicast routing
sockets.

Allow setting and receiving IPOPT_CIPSO, IP_OPT_SEC, IP_OPT_SID and
arbitrary ip options.

Allow setting IP_SEC_POLICY/IP_XFRM_POLICY ipv4 socket option.
Allow setting the IP_TRANSPARENT ipv4 socket option.
Allow setting the TCP_REPAIR socket option.
Allow setting the TCP_CONGESTION socket option.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Push capable(CAP_NET_ADMIN) into the rtnl methods

- In rtnetlink_rcv_msg convert the capable(CAP_NET_ADMIN) check
to ns_capable(net->user-ns, CAP_NET_ADMIN). Allowing unprivileged
users to make netlink calls to modify their local network
namespace.

- In the rtnetlink doit methods add capable(CAP_NET_ADMIN) so
that calls that are not safe for unprivileged users are still
protected.

Later patches will remove the extra capable calls from methods
that are safe for unprivilged users.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Don't export sysctls to unprivileged users

In preparation for supporting the creation of network namespaces
by unprivileged users, modify all of the per net sysctl exports
and refuse to allow them to unprivileged users.

This makes it safe for unprivileged users in general to access
per net sysctls, and allows sysctls to be exported to unprivileged
users on an individual basis as they are deemed safe.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnl/ipv4: use netconf msg to advertise rp_filter status

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnl/ipv4: add support of RTM_GETNETCONF

This message allows to get the devconf for an interface.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnl/ipv4: use netconf msg to advertise forwarding status

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: change return values from -EACCES to -EPERM

Change return value from -EACCES to -EPERM when the permission check fails.

Signed-off-by: Zhao Hongjiang <zhaohongjiang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4/route: arg delay is useless in rt_cache_flush()

Since route cache deletion (89aef8921bfbac22f), delay is no
more used. Remove it.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netlink: Rename pid to portid to avoid confusion

It is a frequent mistake to confuse the netlink port identifier with a
process identifier. Try to reduce this confusion by renaming fields
that hold port identifiers portid instead of pid.

I have carefully avoided changing the structures exported to
userspace to avoid changing the userspace API.

I have successfully built an allyesconfig kernel with this change.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4/route: arg delay is useless in rt_cache_flush()

Since route cache deletion (89aef8921bfbac22f), delay is no
more used. Remove it.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: reinstate rtnl in call_netdevice_notifiers()

Eric Biederman pointed out that not holding RTNL while calling
call_netdevice_notifiers() was racy.

This patch is a direct transcription his feedback
against commit 0115e8e30d6fc (net: remove delay at device dismantle)

Thanks Eric !

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Mahesh Bandewar <maheshb@google.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Gao feng <gaofeng@cn.fujitsu.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: remove delay at device dismantle

I noticed extra one second delay in device dismantle, tracked down to
a call to dst_dev_event() while some call_rcu() are still in RCU queues.

These call_rcu() were posted by rt_free(struct rtable *rt) calls.

We then wait a little (but one second) in netdev_wait_allrefs() before
kicking again NETDEV_UNREGISTER.

As the call_rcu() are now completed, dst_dev_event() can do the needed
device swap on busy dst.

To solve this problem, add a new NETDEV_UNREGISTER_FINAL, called
after a rcu_barrier(), but outside of RTNL lock.

Use NETDEV_UNREGISTER_FINAL with care !

Change dst_dev_event() handler to react to NETDEV_UNREGISTER_FINAL

Also remove NETDEV_UNREGISTER_BATCH, as its not used anymore after
IP cache removal.

With help from Gao feng

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Mahesh Bandewar <maheshb@google.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: change inet_addr_hash()

Use net_hash_mix(net) instead of hash_ptr(net, 8), and use
hash_32() instead of using a serie of XOR

Define IN4_ADDR_HSIZE_SHIFT for clarity

__ip_dev_find() can perform the net_eq() call only if ifa_local
matches the key, to avoid unneeded dereferences.

remove inline attributes

# size net/ipv4/devinet.o.before net/ipv4/devinet.o
text data bss dec hex filename
17471 2545 2048 22064 5630 net/ipv4/devinet.o.before
17335 2545 2048 21928 55a8 net/ipv4/devinet.o

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: Add interface option to enable routing of 127.0.0.0/8

Routing of 127/8 is tradtionally forbidden, we consider
packets from that address block martian when routing and do
not process corresponding ARP requests.

This is a sane default but renders a huge address space
practically unuseable.

The RFC states that no address within the 127/8 block should
ever appear on any network anywhere but it does not forbid
the use of such addresses outside of the loopback device in
particular. For example to address a pool of virtual guests
behind a load balancer.

This patch adds a new interface option 'route_localnet'
enabling routing of the 127/8 address block and processing
of ARP requests on a specific interface.

Note that for the feature to work, the default local route
covering 127/8 dev lo needs to be removed.

Example:
$ sysctl -w net.ipv4.conf.eth0.route_localnet=1
$ ip route del 127.0.0.0/8 dev lo table local
$ ip addr add 127.1.0.1/16 dev eth0
$ ip route flush cache

V2: Fix invalid check to auto flush cache (thanks davem)

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ipv4 and ipv6: Convert printk(KERN_DEBUG to pr_debug

Use the current debugging style and enable dynamic_debug.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net ipv4: Convert devinet to use register_net_sysctl

Using an ascii path to register_net_sysctl as opposed to the slightly
awkward ctl_path allows for much simpler code.

We no longer need to malloc dev_name to keep it alive the length of our
sysctl register instead we can use a small temporary buffer on the
stack.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: cleanup unsigned to unsigned int

Use of "unsigned int" is preferred to bare "unsigned" in net tree.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: Stop using NLA_PUT*().

These macros contain a hidden goto, and are thus extremely error
prone and make code hard to audit.

Signed-off-by: David S. Miller <davem@davemloft.net>

Remove all #inclusions of asm/system.h

Remove all #inclusions of asm/system.h preparatory to splitting and killing
it. Performed with the following command:

perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *`

Signed-off-by: David Howells <dhowells@redhat.com>

bonding: remove entries for master_ip and vlan_ip and query devices instead

The following patch aimed to resolve an issue where secondary, tertiary,
etc. addresses added to bond interfaces could overwrite the
bond->master_ip and vlan_ip values.

commit 917fbdb32f37e9a93b00bb12ee83532982982df3
Author: Henrik Saavedra Persson <henrik.e.persson@ericsson.com>
Date: Wed Nov 23 23:37:15 2011 +0000

bonding: only use primary address for ARP

That patch was good because it prevented bonds using ARP monitoring from
sending frames with an invalid source IP address. Unfortunately, it
didn't always work as expected.

When using an ioctl (like ifconfig does) to set the IP address and
netmask, 2 separate ioctls are actually called to set the IP and netmask
if the mask chosen doesn't match the standard mask for that class of
address. The first ioctl did not have a mask that matched the one in
the primary address and would still cause the device address to be
overwritten. The second ioctl that was called to set the mask would
then detect as secondary and ignored, but the damage was already done.

This was not an issue when using an application that used netlink
sockets as the setting of IP and netmask came down at once. The
inconsistent behavior between those two interfaces was something that
needed to be resolved.

While I was thinking about how I wanted to resolve this, Ralf Zeidler
came with a patch that resolved this on a RHEL kernel by keeping a full
shadow of the entries in dev->ifa_list for the bonding device and vlan
devices in the bonding driver. I didn't like the duplication of the
list as I want to see the 'bonding' struct and code shrink rather than
grow, but liked the general idea.

As the Subject indicates this patch drops the master_ip and vlan_ip
elements from the 'bonding' and 'vlan_entry' structs, respectively.
This can be done because a device's address-list is now traversed to
determine the optimal source IP address for ARP requests and for checks
to see if the bonding device has a particular IP address. This code
could have all be contained inside the bonding driver, but it made more
sense to me to EXPORT and call inet_confirm_addr since it did exactly
what was needed.

I tested this and a backported patch and everything works as expected.
Ralf also helped with verification of the backported patch.

Thanks to Ralf for all his help on this.

v2: Whitespace and organizational changes based on suggestions from Jay
Vosburgh and Dave Miller.

v3: Fixup incorrect usage of rcu_read_unlock based on Dave Miller's
suggestion.

Signed-off-by: Andy Gospodarek <andy@greyhouse.net>
CC: Ralf Zeidler <ralf.zeidler@nsn.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: reintroduce missing rcu_assign_pointer() calls

commit a9b3cd7f32 (rcu: convert uses of rcu_assign_pointer(x, NULL) to
RCU_INIT_POINTER) did a lot of incorrect changes, since it did a
complete conversion of rcu_assign_pointer(x, y) to RCU_INIT_POINTER(x,
y).

We miss needed barriers, even on x86, when y is not NULL.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Stephen Hemminger <shemminger@vyatta.com>
CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: flush route cache after change accept_local

After reset ipv4_devconf->data[IPV4_DEVCONF_ACCEPT_LOCAL] to 0,
we should flush route cache, or it will continue receive packets with local
source address, which should be dropped.

Signed-off-by: Weiping Pan <panweiping3@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rcu: convert uses of rcu_assign_pointer(x, NULL) to RCU_INIT_POINTER

When assigning a NULL value to an RCU protected pointer, no barrier
is needed. The rcu_assign_pointer, used to handle that but will soon
change to not handle the special case.

Convert all rcu_assign_pointer of NULL value.

//smpl
@@ expression P; @@

- rcu_assign_pointer(P, NULL)
+ RCU_INIT_POINTER(P, NULL)

// </smpl>

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

IPv4: Send gratuitous ARP for secondary IP addresses also

If a device event generates gratuitous ARP messages, only primary
address is used for sending. This patch iterates through the whole
list. Tested with 2 IP addresses configuration on bonding interface.

Signed-off-by: Zoltan Kiss <schaman@sch.bme.hu>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: Compute and store minimum ifinfo dump size

The message size allocated for rtnl ifinfo dumps was limited to
a single page. This is not enough for additional interface info
available with devices that support SR-IOV and caused a bug in
which VF info would not be displayed if more than approximately
40 VFs were created per interface.

Implement a new function pointer for the rtnl_register service that will
calculate the amount of data required for the ifinfo dump and allocate
enough data to satisfy the request.

Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

net: fix two lockdep splats

Commit e67f88dd12f6 (net: dont hold rtnl mutex during netlink dump
callbacks) switched rtnl protection to RCU, but we forgot to adjust two
rcu_dereference() lockdep annotations :

inet_get_link_af_size() or inet_fill_link_af() might be called with
rcu_read_lock or rtnl held, so use rcu_dereference_rtnl()
instead of rtnl_dereference()

Reported-by: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

sysctl: net: call unregister_net_sysctl_table where needed

ctl_table_headers registered with register_net_sysctl_table should
have been unregistered with the equivalent unregister_net_sysctl_table

Signed-off-by: Lucian Adrian Grijincu <lucian.grijincu@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4, ipv6, bonding: Restore control over number of peer notifications

For backward compatibility, we should retain the module parameters and
sysfs attributes to control the number of peer notifications
(gratuitous ARPs and unsolicited NAs) sent after bonding failover.
Also, it is possible for failover to take place even though the new
active slave does not have link up, and in that case the peer
notification should be deferred until it does.

Change ipv4 and ipv6 so they do not automatically send peer
notifications on bonding failover.

Change the bonding driver to send separate NETDEV_NOTIFY_PEERS
notifications when the link is up, as many times as requested. Since
it does not directly control which protocols send notifications, make
num_grat_arp and num_unsol_na aliases for a single parameter. Bump
the bonding version number and update its documentation.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>
Acked-by: Brian Haley <brian.haley@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

bonding, ipv4, ipv6, vlan: Handle NETDEV_BONDING_FAILOVER like NETDEV_NOTIFY_PEERS

It is undesirable for the bonding driver to be poking into higher
level protocols, and notifiers provide a way to avoid that. This does
mean removing the ability to configure reptitition of gratuitous ARPs
and unsolicited NAs.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: Fallback to FIB local table in __ip_dev_find().

In commit 9435eb1cf0b76b323019cebf8d16762a50a12a19
("ipv4: Implement __ip_dev_find using new interface address hash.")
we reimplemented __ip_dev_find() so that it doesn't have to
do a full FIB table lookup.

Instead, it consults a hash table of addresses configured to
interfaces.

This works identically to the old code in all except one case,
and that is for loopback subnets.

The old code would match the loopback device for any IP address
that falls within a subnet configured to the loopback device.

Handle this corner case by doing the FIB lookup.

We could implement this via inet_addr_onlink() but:

1) Someone could configure many addresses to loopback and
inet_addr_onlink() is a simple list traversal.

2) We know the old code works.

Reported-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: optimize route adding on secondary promotion

Optimize the calling of fib_add_ifaddr for all
secondary addresses after the promoted one to start from
their place, not from the new place of the promoted
secondary. It will save some CPU cycles because we
are sure the promoted secondary was first for the subnet
and all next secondaries do not change their place.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: remove the routes on secondary promotion

The secondary address promotion relies on fib_sync_down_addr
to remove all routes created for the secondary addresses when
the old primary address is deleted. It does not happen for cases
when the primary address is also in another subnet. Fix that
by deleting local and broadcast routes for all secondaries while
they are on device list and by faking that all addresses from
this subnet are to be deleted. It relies on fib_del_ifaddr being
able to ignore the IPs from the concerned subnet while checking
for duplication.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: Fix erroneous uses of ifa_address.

In usual cases ifa_address == ifa_local, but in the case where
SIOCSIFDSTADDR sets the destination address on a point-to-point
link, ifa_address gets set to that destination address.

Therefore we should use ifa_local when we want the local interface
address.

There were two cases where the selection was done incorrectly:

1) When devinet_ioctl() does matching, it checks ifa_address even
though gifconf correct reported ifa_local to the user

2) IN_DEV_ARP_NOTIFY handling sends a gratuitous ARP using
ifa_address instead of ifa_local.

Reported-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: Fix __ip_dev_find() to use ifa_local instead of ifa_address.

Reported-by: Stephen Hemminger <shemminger@vyatta.com>
Reported-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: Implement __ip_dev_find using new interface address hash.

Much quicker than going through the FIB tables.

Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: Add hash table of interface addresses.

This will be used to optimize __ip_dev_find() and friends.

With help from Eric Dumazet.

Signed-off-by: David S. Miller <davem@davemloft.net>

arp_notify: unconditionally send gratuitous ARP for NETDEV_NOTIFY_PEERS.

NETDEV_NOTIFY_PEER is an explicit request by the driver to send a link
notification while NETDEV_UP/NETDEV_CHANGEADDR generate link
notifications as a sort of side effect.

In the later cases the sysctl option is present because link
notification events can have undesired effects e.g. if the link is
flapping. I don't think this applies in the case of an explicit
request from a driver.

This patch makes NETDEV_NOTIFY_PEER unconditional, if preferred we
could add a new sysctl for this case which defaults to on.

This change causes Xen post-migration ARP notifications (which cause
switches to relearn their MAC tables etc) to be sent by default.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: Don't pre-seed hoplimit metric.

Always go through a new ip4_dst_hoplimit() helper, just like ipv6.

This allowed several simplifications:

1) The interim dst_metric_hoplimit() can go as it's no longer
userd.

2) The sysctl_ip_default_ttl entry no longer needs to use
ipv4_doint_and_flush, since the sysctl is not cached in
routing cache metrics any longer.

3) ipv4_doint_and_flush no longer needs to be exported and
therefore can be marked static.

When ipv4_doint_and_flush_strategy was removed some time ago,
the external declaration in ip.h was mistakenly left around
so kill that off too.

We have to move the sysctl_ip_default_ttl declaration into
ipv4's route cache definition header net/route.h, because
currently net/ip.h (where the declaration lives now) has
a back dependency on net/route.h

Signed-off-by: David S. Miller <davem@davemloft.net>

net: kill an RCU warning in inet_fill_link_af()

commits 9f0f7272 (ipv4: AF_INET link address family) and cf7afbfeb8c
(rtnl: make link af-specific updates atomic) used incorrect
__in_dev_get_rcu() in RTNL protected contexts, triggering PROVE_RCU
warnings.

Switch to __in_dev_get_rtnl(), wich is more appropriate, since we hold
RTNL.

Based on a report and initial patch from Amerigo Wang.

Reported-by: Amerigo Wang <amwang@redhat.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Thomas Graf <tgraf@infradead.org>
Reviewed-by: WANG Cong <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnl: make link af-specific updates atomic

As David pointed out correctly, updates to af-specific attributes
are currently not atomic. If multiple changes are requested and
one of them fails, previous updates may have been applied already
leaving the link behind in a undefined state.

This patch splits the function parse_link_af() into two functions
validate_link_af() and set_link_at(). validate_link_af() is placed
to validate_linkmsg() check for errors as early as possible before
any changes to the link have been made. set_link_af() is called to
commit the changes later.

This method is not fail proof, while it is currently sufficient
to make set_link_af() inerrable and thus 100% atomic, the
validation function method will not be able to detect all error
scenarios in the future, there will likely always be errors
depending on states which are f.e. not protected by rtnl_mutex
and thus may change between validation and setting.

Also, instead of silently ignoring unknown address families and
config blocks for address families which did not register a set
function the errors EAFNOSUPPORT respectively EOPNOSUPPORT are
returned to avoid comitting 4 out of 5 update requests without
notifying the user.

Signed-off-by: Thomas Graf <tgraf@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: AF_INET link address family

Implements the AF_INET link address family exposing the per
device configuration settings via netlink using the attribute
IFLA_INET_CONF.

The format of IFLA_INET_CONF differs depending on the direction
the attribute is sent. The attribute sent by the kernel consists
of a u32 array, basically a 1:1 copy of in_device->cnf.data[].
The attribute expected by the kernel must consist of a sequence
of nested u32 attributes, each representing a change request,
e.g.
[IFLA_INET_CONF] = {
[IPV4_DEVCONF_FORWARDING] = 1,
[IPV4_DEVCONF_NOXFRM] = 0,
}

libnl userspace API documentation and example available from:
http://www.infradead.org/~tgr/libnl/doc-git/group__link__inet.html

Signed-off-by: Thomas Graf <tgraf@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

inet: RCU changes in inetdev_by_index()

Convert inetdev_by_index() to not increment in_dev refcount.

Callers hold RCU or RTNL, and should not decrement in_dev refcount.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: ip_ptr cleanups

dev->ip_ptr is protected by rtnl and rcu.

Yet some places dont use appropriate primitives and/or locking rules.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

arp_notify: allow drivers to explicitly request a notification event.

Currently such notifications are only generated when the device comes up or the
address changes. However one use case for these notifications is to enable
faster network recovery after a virtual machine migration (by causing switches
to relearn their MAC tables). A migration appears to the network stack as a
temporary loss of carrier and therefore does not trigger either of the current
conditions. Rather than adding carrier up as a trigger (which can cause issues
when interfaces a flapping) simply add an interface which the driver can use
to explicitly trigger the notification.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Stephen Hemminger <shemminger@linux-foundation.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Cc: stable@kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

net: fix netlink address dumping in IPv4/IPv6

When a dump is interrupted at the last device in a hash chain and
then continued, "idx" won't get incremented past s_idx, so s_ip_idx
is not reset when moving on to the next device. This means of all
following devices only the last n - s_ip_idx addresses are dumped.

Tested-by: Pawel Staszewski <pstaszewski@itcare.pl>
Signed-off-by: Patrick McHardy <kaber@trash.net>

net: rename notifier defines for netdev type change

Since generally there could be more netdevices changing type other
than bonding, making this event type name "bonding-unrelated"

Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Fix sysctl restarts...

Yuck. It turns out that when we restart sysctls we were restarting
with the values already changed. Which unfortunately meant that
the second time through we thought there was no change and skipped
all kinds of work, despite the fact that there was indeed a change.

I have fixed this the simplest way possible by restoring the changed
values when we restart the sysctl write.

One of my coworkers spotted this bug when after disabling forwarding
on an interface pings were still forwarded.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net neigh: Decouple per interface neighbour table controls from binary sysctls

Stop computing the number of neighbour table settings we have by
counting the number of binary sysctls. This behaviour was silly
and meant that we could not add another neighbour table setting
without also adding another binary sysctl.

Don't pass the binary sysctl path for neighour table entries
into neigh_sysctl_register. These parameters are no longer
used and so are just dead code.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net ipv4: Decouple ipv4 interface parameters from binary sysctl numbers

Stop using the binary sysctl enumeartion in sysctl.h as an index into
a per interface array. This leads to unnecessary binary sysctl number
allocation, and a fragility in data structure and implementation
because of unnecessary coupling.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: RFC3069, private VLAN proxy arp support

This is to be used together with switch technologies, like RFC3069,
that where the individual ports are not allowed to communicate with
each other, but they are allowed to talk to the upstream router. As
described in RFC 3069, it is possible to allow these hosts to
communicate through the upstream router by proxy_arp'ing.

This patch basically allow proxy arp replies back to the same
interface (from which the ARP request/solicitation was received).

Tunable per device via proc "proxy_arp_pvlan":
/proc/sys/net/ipv4/conf/*/proxy_arp_pvlan

This switch technology is known by different vendor names:
- In RFC 3069 it is called VLAN Aggregation.
- Cisco and Allied Telesyn call it Private VLAN.
- Hewlett-Packard call it Source-Port filtering or port-isolation.
- Ericsson call it MAC-Forced Forwarding (RFC Draft).

Signed-off-by: Jesper Dangaard Brouer <hawk@comx.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: restore ip source validation

when using policy routing and the skb mark:
there are cases where a back path validation requires us
to use a different routing table for src ip validation than
the one used for mapping ingress dst ip.
One such a case is transparent proxying where we pretend to be
the destination system and therefore the local table
is used for incoming packets but possibly a main table would
be used on outbound.
Make the default behavior to allow the above and if users
need to turn on the symmetry via sysctl src_valid_mark

Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4 05/05: add sysctl to accept packets with local source addresses

commit 8ec1e0ebe26087bfc5c0394ada5feb5758014fc8
Author: Patrick McHardy <kaber@trash.net>
Date: Thu Dec 3 12:16:35 2009 +0100

ipv4: add sysctl to accept packets with local source addresses

Change fib_validate_source() to accept packets with a local source address when
the "accept_local" sysctl is set for the incoming inet device. Combined with the
previous patches, this allows to communicate between multiple local interfaces
over the wire.

Signed-off-by: Patrick McHardy <kaber@trash.net>

Signed-off-by: David S. Miller <davem@davemloft.net>

net: use net_eq to compare nets

Generated with the following semantic patch

@@
struct net *n1;
struct net *n2;
@@
- n1 == n2
+ net_eq(n1, n2)

@@
struct net *n1;
struct net *n2;
@@
- n1 != n2
+ !net_eq(n1, n2)

applied over {include,net,drivers/net}.

Signed-off-by: Octavian Purdila <opurdila@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: speedup inet_dump_ifaddr()

Stephen Hemminger a écrit :
> On Thu, 12 Nov 2009 15:11:36 +0100
> Eric Dumazet <eric.dumazet@gmail.com> wrote:
>
>> When handling large number of netdevices, inet_dump_ifaddr()
>> is very slow because it has O(N^2) complexity.
>>
>> Instead of scanning one single list, we can use the NETDEV_HASHENTRIES
>> sub lists of the dev_index hash table, and RCU lookups.
>>
>> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
>
> You might be able to make RCU critical section smaller by moving
> it into loop.
>

Indeed. But we dump at most one skb (<= 8192 bytes ?), so rcu_read_lock
holding time is small, unless we meet many netdevices without
addresses. I wonder if its really common...

Thanks

[PATCH net-next-2.6] ipv4: speedup inet_dump_ifaddr()

When handling large number of netdevices, inet_dump_ifaddr()
is very slow because it has O(N2) complexity.

Instead of scanning one single list, we can use the NETDEV_HASHENTRIES
sub lists of the dev_index hash table, and RCU lookups.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

sysctl net: Remove unused binary sysctl code

Now that sys_sysctl is a compatiblity wrapper around /proc/sys
all sysctl strategy routines, and all ctl_name and strategy
entries in the sysctl tables are unused, and can be
revmoed.

In addition neigh_sysctl_register has been modified to no longer
take a strategy argument and it's callers have been modified not
to pass one.

Cc: "David Miller" <davem@davemloft.net>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: netdev@vger.kernel.org
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

net: net/ipv4/devinet.c cleanups

As pointed by Stephen Rothwell, commit c6d14c84 added a warning :

net/ipv4/devinet.c: In function 'inet_select_addr':
net/ipv4/devinet.c:902: warning: label 'out' defined but not used

delete unused 'out' label and do some cleanups as well

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Introduce for_each_netdev_rcu() iterator

Adds RCU management to the list of netdevices.

Convert some for_each_netdev() users to RCU version, if
it can avoid read_lock-ing dev_base_lock

Ie:
read_lock(&dev_base_loack);
for_each_netdev(net, dev)
some_action();
read_unlock(&dev_base_lock);

becomes :

rcu_read_lock();
for_each_netdev_rcu(net, dev)
some_action();
rcu_read_unlock();


Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: inetdev_by_index() switch to RCU

Use dev_get_by_index_rcu() instead of __dev_get_by_index() and
dev_base_lock rwlock

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: arp_notify address list bug

This fixes a bug with arp_notify.

If arp_notify is enabled, kernel will crash if address is changed
and no IP address is assigned.
http://bugzilla.kernel.org/show_bug.cgi?id=14330

Reported-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

sysctl: remove "struct file *" argument of ->proc_handler

It's unused.

It isn't needed -- read or write flag is already passed and sysctl
shouldn't care about the rest.

It _was_ used in two places at arch/frv for some reason.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

bonding: remap muticast addresses without using dev_close() and dev_open()

This patch fixes commit e36b9d16c6a6d0f59803b3ef04ff3c22c3844c10. The approach
there is to call dev_close()/dev_open() whenever the device type is changed in
order to remap the device IP multicast addresses to HW multicast addresses.
This approach suffers from 2 drawbacks:

*. It assumes tha the device is UP when calling dev_close(), or otherwise
dev_close() has no affect. It is worth to mention that initscripts (Redhat)
and sysconfig (Suse) doesn't act the same in this matter.
*. dev_close() has other side affects, like deleting entries from the routing
table, which might be unnecessary.

The fix here is to directly remap the IP multicast addresses to HW multicast
addresses for a bonding device that changes its type, and nothing else.

Reported-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: Moni Shoua <monis@voltaire.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Fix devinet_sysctl_forward

sysctls are unregistered with the rntl_lock held making
it unsafe to unconditionally grab the the rtnl_lock. Instead
we need to call rtnl_trylock and restart the system call
if we can not grab it. Otherwise we could deadlock at unregistration
time.

Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netlink: change nlmsg_notify() return value logic

This patch changes the return value of nlmsg_notify() as follows:

If NETLINK_BROADCAST_ERROR is set by any of the listeners and
an error in the delivery happened, return the broadcast error;
else if there are no listeners apart from the socket that
requested a change with the echo flag, return the result of the
unicast notification. Thus, with this patch, the unicast
notification is handled in the same way of a broadcast listener
that has set the NETLINK_BROADCAST_ERROR socket flag.

This patch is useful in case that the caller of nlmsg_notify()
wants to know the result of the delivery of a netlink notification
(including the broadcast delivery) and take any action in case
that the delivery failed. For example, ctnetlink can drop packets
if the event delivery failed to provide reliable logging and
state-synchronization at the cost of dropping packets.

This patch also modifies the rtnetlink code to ignore the return
value of rtnl_notify() in all callers. The function rtnl_notify()
(before this patch) returned the error of the unicast notification
which makes rtnl_set_sk_err() reports errors to all listeners. This
is not of any help since the origin of the change (the socket that
requested the echoing) notices the ENOBUFS error if the notification
fails and should resync itself.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: add ARP notify option for devices

This adds another inet device option to enable gratuitous ARP
when device is brought up or address change. This is handy for
clusters or virtualization.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: clean up net/ipv4/devinet.c

Signed-off-by: Jianjun Kong <jianjun@zeuux.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: don't use INIT_RCU_HEAD

call_rcu() will unconditionally rewrite RCU head anyway.
Applies to
struct neigh_parms
struct neigh_table
struct net
struct cipso_v4_doi
struct in_ifaddr
struct in_device
rt->u.dst

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Remove CONFIG_KMOD from net/ (towards removing CONFIG_KMOD entirely)

Some code here depends on CONFIG_KMOD to not try to load
protocol modules or similar, replace by CONFIG_MODULES
where more than just request_module depends on CONFIG_KMOD
and and also use try_then_request_module in ebtables.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

sysctl: simplify ->strategy

name and nlen parameters passed to ->strategy hook are unused, remove
them. In general ->strategy hook should know what it's doing, and don't
do something tricky for which, say, pointer to original userspace array
may be needed (name).

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net> [ networking bits ]
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ipv: Re-enable IP when MTU > 68

Re-enable IP when the MTU gets back to a valid size.

This patch just checks if the in_dev is NULL on a NETDEV_CHANGEMTU event
and if MTU is valid (bigger than 68), then re-enable in_dev.

Also a function that checks valid MTU size was created.

Signed-off-by: Breno Leitao <leitao@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: convert BUG_TRAP to generic WARN_ON

Removes legacy reinvent-the-wheel type thing. The generic
machinery integrates much better to automated debugging aids
such as kerneloops.org (and others), and is unambiguous due to
better naming. Non-intuively BUG_TRAP() is actually equal to
WARN_ON() rather than BUG_ON() though some might actually be
promoted to BUG_ON() but I left that to future.

I could make at least one BUILD_BUG_ON conversion.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>

netns: add namespace parameter to rt_cache_flush

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Disable LRO on devices that are forwarding

Large Receive Offload (LRO) is only appropriate for packets that are
destined for the host, and should be disabled if received packets may be
forwarded. It can also confuse the GSO on output.

Add dev_disable_lro() function which uses the appropriate ethtool ops to
disable LRO if enabled.

Add calls to dev_disable_lro() in br_add_if() and functions that enable
IPv4 and IPv6 forwarding.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: remove CVS keywords

This patch removes CVS keywords that weren't updated for a long time
from comments.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4 addr: Send netlink notification for address label changes

Makes people happy who try to keep a list of addresses up to date by
listening to notifications.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

route: Remove unused ifa_anycast field

The field was supposed to allow the creation of an anycast route by
assigning an anycast address to an address prefix. It was never
implemented so this field is unused and serves no purpose. Remove it.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NET] NETNS: Omit sock->sk_net without CONFIG_NET_NS.

Introduce per-sock inlines: sock_net(), sock_net_set()
and per-inet_timewait_sock inlines: twsk_net(), twsk_net_set().
Without CONFIG_NET_NS, no namespace other than &init_net exists.
Let's explicitly define them to help compiler optimizations.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

[NET] NETNS: Omit net_device->nd_net without CONFIG_NET_NS.

Introduce per-net_device inlines: dev_net(), dev_net_set().
Without CONFIG_NET_NS, no namespace other than &init_net exists.
Let's explicitly define them to help compiler optimizations.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

[NETNS]: Process inet_select_addr inside a namespace.

The context is available from a network device passed in.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NETNS]: Enable IPv4 address manipulations inside namespace.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NETNS]: Process devinet ioctl in the correct namespace.

Add namespace parameter to devinet_ioctl and locate device inside it for
state changes.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NETNS]: Enable inetdev_event notifier.

After all these preparations it is time to enable main IPv4 device
initialization routine inside namespace. It is safe do this now.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[IPV4]: Reset scope when changing address

This bug did bite at least one user, who did have to resort to rebooting
the system after an "ifconfig eth0 127.0.0.1" typo.

Deleting the address and adding a new is a less intrusive workaround.
But I still beleive this is a bug that should be fixed. Some way or
another.

Another possibility would be to remove the scope mangling based on
address. This will always be incomplete (are 127/8 the only address
space with host scope requirements?)

We set the scope to RT_SCOPE_HOST if an IPv4 interface is configured
with a loopback address (127/8). The scope is never reset, and will
remain set to RT_SCOPE_HOST after changing the address. This patch
resets the scope if the address is changed again, to restore normal
functionality.

Signed-off-by: Bjorn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NETNS]: Process interface address manipulation routines in the namespace.

The namespace is available when required except rtm_to_ifaddr. Add
namespace argument to it.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[IPV4]: Small style cleanup of the error path in rtm_to_ifaddr.

Remove error code assignment inside brackets on failure. The code
looks better if the error is assigned before condition check. Also,
the compiler treats this better.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[IPV4]: Make struct ipv4_devconf static.

struct ipv4_devconf can now become static.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NETNS]: Add netns parameter to inetdev_by_index.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NETNS]: Process inet_confirm_addr in the correct namespace.

inet_confirm_addr can be called with NULL in_dev from arp_ignore iff
scope is RT_SCOPE_LINK.

Lets always pass the device and check for RT_SCOPE_LINK scope inside
inet_confirm_addr. This let us take network namespace from in_device a
need for an additional argument.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[IPV4]: Remove extra argument from arp_ignore.

arp_ignore has two arguments: dev & in_dev. dev is used for
inet_confirm_addr calling only.

inet_confirm_addr, in turn, either gets in_dev from the device passed
or iterates over all network devices if the device passed is NULL. It
seems logical to directly pass in_dev into inet_confirm_addr.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NETNS]: Should build with CONFIG_SYSCTL=n

Previous NETNS patches broke CONFIG_SYSCTL=n case

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

[IPV4] net/ipv4: Use ipv4_is_<type>

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

[IPV4]: Switch users of ipv4_devconf(_all) to use the pernet one

These are scattered over the code, but almost all the
"critical" places already have the proper struct net
at hand except for snmp proc showing function and routing
rtnl handler.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[IPV4]: Switch users of ipv4_devconf_dflt to use the pernet one

They are all collected in the net/ipv4/devinet.c file and
mostly use the IPV4_DEVCONF_DFLT macro.

So I add the net parameter to it and patch users accordingly.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[IPV4]: Move the devinet pointers on the struct net

This is the core.

Add all and default pointers on the netns_ipv4 and register
a new pernet subsys to initialize them.

Also add the ctl_table_header to register the
net.ipv4.ip_forward ctl.

I don't allocate additional memory for init_net, but use
global devinets.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[IPV4]: Store the net pointer on devinet's ctl tables

Some handers and strategies of devinet sysctl tables need
to know the net to propagate the ctl change to all the
net devices.

I use the (currently unused) extra2 pointer on the tables
to get it.

Holding the reference on the struct net is not possible,
because otherwise we'll get a net->ctl_table->net circular
dependency. But since the ctl tables are unregistered during
the net destruction, this is safe to get it w/o additional
protection.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[IPV4]: Make __devinet_sysctl_register return an error

Currently, this function is void, so failures in creating
sysctls for new/renamed devices are not reported to anywhere.

Fixing this is another complex (needed?) task, but this
return value is needed during the namespaces creation to
handle the case, when we failed to create "all" and "default"
entries.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[IPV4]: Cleanup sysctl manipulations in devinet.c

This includes:

* moving neigh_sysctl_(un)register calls inside
devinet_sysctl_(un)register ones, as they are always
called in pairs;
* making __devinet_sysctl_unregister() to unregister
the ipv4_devconf struct, while original devinet_sysctl_unregister()
works with the in_device to handle both - devconf and
neigh sysctls;
* make stubs for CONFIG_SYSCTL=n case to get rid of
in-code ifdefs.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[INET]: Merge sys.net.ipv4.ip_forward and sys.net.ipv4.conf.all.forwarding

AFAIS these two entries should do the same thing - change the
forwarding state on ipv4_devconf and on all the devices.

I propose to merge the handlers together using ctl paths.

The inet_forward_change() is static after this and I move
it higher to be closer to other "propagation" helpers and
to avoid diff making patches based on { and } matching :)
i.e. - make them easier to read.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[IPV4]: Use ctl paths to register devinet sysctls

This looks very much like the patch for neighbors.

The path is also located on the stack and is prepared
inside the function. This time, the call to the registering
function is guarded with the RTNL lock, but I decided
to keep it on the stack not to litter the devinet.c file
with unneeded names and to make it look similar to the
neighbors code.

This is also intended to help us with the net namespaces
and saves the vmlinux size as well - this time by more
than 670 bytes.

The difference from the first version is just the patch
offsets, that changed due to changes in the patch #2.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

[IPV4]: Unify and cleanup calls to devinet_sysctl_register

Currently this call is used to register sysctls for devices
and for the "default" confs. The "all" sysctls are registered
separately.

Besides, the inet_device is passed to this function, but it is
not needed there at all - just the device name and ifindex are
required.

Thanks to Herbert, who noticed, that this call doesn't even
require the devconf pointer (the last argument) - all we need
we can take from the in_device itself.

The fix is to make a __devinet_sysctl_register(), which registers
sysctls for all "devices" we need, including "default" and "all" :)

The original devinet_sysctl_register() works with struct net_device,
not the inet_device, and calls the introduced function, passing
the device name and ifindex (to be used as procname and ctl_name)
into it.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

[IPV4]: Cleanup the devinet_sysctl_register

I moved the call to kmalloc() from the *t declaration into
the code (this is confusing when a variable is initialized
with the result of some call) and removed unneeded comment
near the error path. Just like I did with the neigh ctl-s.

Besides, I fixed the goto's and the labels - they were indented
with spaces :(

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NET]: Make rtnetlink infrastructure network namespace aware (v3)

After this patch none of the netlink callback support anything
except the initial network namespace but the rtnetlink infrastructure
now handles multiple network namespaces.

Changes from v2:
- IPv6 addrlabel processing

Changes from v1:
- no need for special rtnl_unlock handling
- fixed IPv6 ndisc

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NET]: Modify all rtnetlink methods to only work in the initial namespace (v2)

Before I can enable rtnetlink to work in all network namespaces I need
to be certain that something won't break. So this patch deliberately
disables all of the rtnletlink methods in everything except the
initial network namespace. After the methods have been audited this
extra check can be disabled.

Changes from v1:
- added IPv6 addrlabel protection

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

[INET]: Fix netdev renaming and inet address labels

When re-naming an interface, the previous secondary address
labels get lost e.g.

$> brctl addbr foo
$> ip addr add 192.168.0.1 dev foo
$> ip addr add 192.168.0.2 dev foo label foo:00
$> ip addr show dev foo | grep inet
inet 192.168.0.1/32 scope global foo
inet 192.168.0.2/32 scope global foo:00
$> ip link set foo name bar
$> ip addr show dev bar | grep inet
inet 192.168.0.1/32 scope global bar
inet 192.168.0.2/32 scope global bar:2

Turns out to be a simple thinko in inetdev_changename() - clearly we
want to look at the address label, rather than the device name, for
a suffix to retain.

Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

[IPV4]: Swap the ifa allocation with the"ipv4_devconf_setall" call

According to Herbert, the ipv4_devconf_setall should be called
only when the ifa is added to the device. However, failed
ifa allocation may bring things into inconsistent state.

Move the call to ipv4_devconf_setall after the ifa allocation.

Fits both net-2.6 (with offsets) and net-2.6.25 (cleanly).

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

[IPV4]: When possible test for IFF_LOOPBACK and not dev == loopback_dev

Now that multiple loopback devices are becoming possible it makes
the code a little cleaner and more maintainable to test if a deivice
is th a loopback device by testing dev->flags & IFF_LOOPBACK instead
of dev == loopback_dev.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

[IPV4]: Remove unnecessary test for the loopback device from inetdev_destroy

Currently we never call unregister_netdev for the loopback device so
it is impossible for us to reach inetdev_destroy with the loopback
device. So the test in inetdev_destroy is unnecessary.

Further when testing with my network namespace patches removing
unregistering the loopback device and calling inetdev_destroy works
fine so there appears to be no reason for avoiding unregistering the
loopback device.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NET]: Dynamically allocate the loopback device, part 1.

This patch replaces all occurences to the static variable
loopback_dev to a pointer loopback_dev. That provides the
mindless, trivial, uninteressting change part for the dynamic
allocation for the loopback.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Acked-By: Kirill Korotaev <dev@sw.ru>
Acked-by: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NET]: Make the device list and device lookups per namespace.

This patch makes most of the generic device layer network
namespace safe. This patch makes dev_base_head a
network namespace variable, and then it picks up
a few associated variables. The functions:
dev_getbyhwaddr
dev_getfirsthwbytype
dev_get_by_flags
dev_get_by_name
__dev_get_by_name
dev_get_by_index
__dev_get_by_index
dev_ioctl
dev_ethtool
dev_load
wireless_process_ioctl

were modified to take a network namespace argument, and
deal with it.

vlan_ioctl_set and brioctl_set were modified so their
hooks will receive a network namespace argument.

So basically anthing in the core of the network stack that was
affected to by the change of dev_base was modified to handle
multiple network namespaces. The rest of the network stack was
simply modified to explicitly use &init_net the initial network
namespace. This can be fixed when those components of the network
stack are modified to handle multiple network namespaces.

For now the ifindex generator is left global.

Fundametally ifindex numbers are per namespace, or else
we will have corner case problems with migration when
we get that far.

At the same time there are assumptions in the network stack
that the ifindex of a network device won't change. Making
the ifindex number global seems a good compromise until
the network stack can cope with ifindex changes when
you change namespaces, and the like.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NET]: Make device event notification network namespace safe

Every user of the network device notifiers is either a protocol
stack or a pseudo device. If a protocol stack that does not have
support for multiple network namespaces receives an event for a
device that is not in the initial network namespace it quite possibly
can get confused and do the wrong thing.

To avoid problems until all of the protocol stacks are converted
this patch modifies all netdev event handlers to ignore events on
devices that are not in the initial network namespace.

As the rest of the code is made network namespace aware these
checks can be removed.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

[IPV4] devinet: show all addresses assigned to interface

Bug: http://bugzilla.kernel.org/show_bug.cgi?id=8876

Not all ips are shown by "ip addr show" command when IPs number assigned to an
interface is more than 60-80 (in fact it depends on broadcast/label etc
presence on each address).

Steps to reproduce:
It's terribly simple to reproduce:

# for i in $(seq 1 100); do ip ad add 10.0.$i.1/24 dev eth10 ; done
# ip addr show

this will _not_ show all IPs.
Looks like the problem is in netlink/ipv4 message processing.

This is fix from bug submitter, it looks correct.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>