History log of /linux-master/net/netfilter/ipvs/ip_vs_xmit.c
Revision Date Author Comments
# d6938c1c 15-Jan-2024 Fedor Pchelkin <pchelkin@ispras.ru>

ipvs: avoid stat macros calls from preemptible context

Inside decrement_ttl() upon discovering that the packet ttl has exceeded,
__IP_INC_STATS and __IP6_INC_STATS macros can be called from preemptible
context having the following backtrace:

check_preemption_disabled: 48 callbacks suppressed
BUG: using __this_cpu_add() in preemptible [00000000] code: curl/1177
caller is decrement_ttl+0x217/0x830
CPU: 5 PID: 1177 Comm: curl Not tainted 6.7.0+ #34
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0xbd/0xe0
check_preemption_disabled+0xd1/0xe0
decrement_ttl+0x217/0x830
__ip_vs_get_out_rt+0x4e0/0x1ef0
ip_vs_nat_xmit+0x205/0xcd0
ip_vs_in_hook+0x9b1/0x26a0
nf_hook_slow+0xc2/0x210
nf_hook+0x1fb/0x770
__ip_local_out+0x33b/0x640
ip_local_out+0x2a/0x490
__ip_queue_xmit+0x990/0x1d10
__tcp_transmit_skb+0x288b/0x3d10
tcp_connect+0x3466/0x5180
tcp_v4_connect+0x1535/0x1bb0
__inet_stream_connect+0x40d/0x1040
inet_stream_connect+0x57/0xa0
__sys_connect_file+0x162/0x1a0
__sys_connect+0x137/0x160
__x64_sys_connect+0x72/0xb0
do_syscall_64+0x6f/0x140
entry_SYSCALL_64_after_hwframe+0x6e/0x76
RIP: 0033:0x7fe6dbbc34e0

Use the corresponding preemption-aware variants: IP_INC_STATS and
IP6_INC_STATS.

Found by Linux Verification Center (linuxtesting.org).

Fixes: 8d8e20e2d7bb ("ipvs: Decrement ttl")
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Acked-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Simon Horman <horms@kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>


# d7fce52f 09-Jun-2023 Terin Stock <terin@cloudflare.com>

ipvs: align inner_mac_header for encapsulation

When using encapsulation the original packet's headers are copied to the
inner headers. This preserves the space for an inner mac header, which
is not used by the inner payloads for the encapsulation types supported
by IPVS. If a packet is using GUE or GRE encapsulation and needs to be
segmented, flow can be passed to __skb_udp_tunnel_segment() which
calculates a negative tunnel header length. A negative tunnel header
length causes pskb_may_pull() to fail, dropping the packet.

This can be observed by attaching probes to ip_vs_in_hook(),
__dev_queue_xmit(), and __skb_udp_tunnel_segment():

perf probe --add '__dev_queue_xmit skb->inner_mac_header \
skb->inner_network_header skb->mac_header skb->network_header'
perf probe --add '__skb_udp_tunnel_segment:7 tnl_hlen'
perf probe -m ip_vs --add 'ip_vs_in_hook skb->inner_mac_header \
skb->inner_network_header skb->mac_header skb->network_header'

These probes the headers and tunnel header length for packets which
traverse the IPVS encapsulation path. A TCP packet can be forced into
the segmentation path by being smaller than a calculated clamped MSS,
but larger than the advertised MSS.

probe:ip_vs_in_hook: inner_mac_header=0x0 inner_network_header=0x0 mac_header=0x44 network_header=0x52
probe:ip_vs_in_hook: inner_mac_header=0x44 inner_network_header=0x52 mac_header=0x44 network_header=0x32
probe:dev_queue_xmit: inner_mac_header=0x44 inner_network_header=0x52 mac_header=0x44 network_header=0x32
probe:__skb_udp_tunnel_segment_L7: tnl_hlen=-2

When using veth-based encapsulation, the interfaces are set to be
mac-less, which does not preserve space for an inner mac header. This
prevents this issue from occurring.

In our real-world testing of sending a 32KB file we observed operation
time increasing from ~75ms for veth-based encapsulation to over 1.5s
using IPVS encapsulation due to retries from dropped packets.

This changeset modifies the packet on the encapsulation path in
ip_vs_tunnel_xmit() and ip_vs_tunnel_xmit_v6() to remove the inner mac
header offset. This fixes UDP segmentation for both encapsulation types,
and corrects the inner headers for any IPIP flows that may use it.

Fixes: 84c0d5e96f3a ("ipvs: allow tunneling with gue encapsulation")
Signed-off-by: Terin Stock <terin@cloudflare.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Simon Horman <horms@kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>


# 3f06760c 01-Jun-2023 Guillaume Nault <gnault@redhat.com>

ipv4: Drop tos parameter from flowi4_update_output()

Callers of flowi4_update_output() never try to update ->flowi4_tos:

* ip_route_connect() updates ->flowi4_tos with its own current
value.

* ip_route_newports() has two users: tcp_v4_connect() and
dccp_v4_connect. Both initialise fl4 with ip_route_connect(), which
in turn sets ->flowi4_tos with RT_TOS(inet_sk(sk)->tos) and
->flowi4_scope based on SOCK_LOCALROUTE.

Then ip_route_newports() updates ->flowi4_tos with
RT_CONN_FLAGS(sk), which is the same as RT_TOS(inet_sk(sk)->tos),
unless SOCK_LOCALROUTE is set on the socket. In that case, the
lowest order bit is set to 1, to eventually inform
ip_route_output_key_hash() to restrict the scope to RT_SCOPE_LINK.
This is equivalent to properly setting ->flowi4_scope as
ip_route_connect() did.

* ip_vs_xmit.c initialises ->flowi4_tos with memset(0), then calls
flowi4_update_output() with tos=0.

* sctp_v4_get_dst() uses the same RT_CONN_FLAGS_TOS() when
initialising ->flowi4_tos and when calling flowi4_update_output().

In the end, ->flowi4_tos never changes. So let's just drop the tos
parameter. This will simplify the conversion of ->flowi4_tos from __u8
to dscp_t.

Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>


# 210ffe4a 17-Apr-2023 Simon Horman <horms@kernel.org>

ipvs: Remove {Enter,Leave}Function

Remove EnterFunction and LeaveFunction.

These debugging macros seem well past their use-by date. And seem to
have little value these days. Removing them allows some trivial cleanup
of some exit paths for some functions. These are also included in this
patch. There is likely scope for further cleanup of both debugging and
unwind paths. But let's leave that for another day.

Only intended to change debug output, and only when CONFIG_IP_VS_DEBUG
is enabled. Compile tested only.

Signed-off-by: Simon Horman <horms@kernel.org>
Reviewed-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>


# bc9d3a9f 23-Mar-2023 Thomas Gleixner <tglx@linutronix.de>

net: dst: Switch to rcuref_t reference counting

Under high contention dst_entry::__refcnt becomes a significant bottleneck.

atomic_inc_not_zero() is implemented with a cmpxchg() loop, which goes into
high retry rates on contention.

Switch the reference count to rcuref_t which results in a significant
performance gain. Rename the reference count member to __rcuref to reflect
the change.

The gain depends on the micro-architecture and the number of concurrent
operations and has been measured in the range of +25% to +130% with a
localhost memtier/memcached benchmark which amplifies the problem
massively.

Running the memtier/memcached benchmark over a real (1Gb) network
connection the conversion on top of the false sharing fix for struct
dst_entry::__refcnt results in a total gain in the 2%-5% range over the
upstream baseline.

Reported-by: Wangyang Guo <wangyang.guo@intel.com>
Reported-by: Arjan Van De Ven <arjan.van.de.ven@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230307125538.989175656@linutronix.de
Link: https://lore.kernel.org/r/20230323102800.215027837@linutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>


# a13fbf5e 28-Jan-2023 Xin Long <lucien.xin@gmail.com>

netfilter: use skb_ip_totlen and iph_totlen

There are also quite some places in netfilter that may process IPv4 TCP
GSO packets, we need to replace them too.

In length_mt(), we have to use u_int32_t/int to accept skb_ip_totlen()
return value, otherwise it may overflow and mismatch. This change will
also help us add selftest for IPv4 BIG TCP in the following patch.

Note that we don't need to replace the one in tcpmss_tg4(), as it will
return if there is data after tcphdr in tcpmss_mangle_packet(). The
same in mangle_contents() in nf_nat_helper.c, it returns false when
skb->len + extra > 65535 in enlarge_skb().

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>


# de799101 02-Mar-2022 Martin KaFai Lau <kafai@fb.com>

net: Add skb_clear_tstamp() to keep the mono delivery_time

Right now, skb->tstamp is reset to 0 whenever the skb is forwarded.

If skb->tstamp has the mono delivery_time, clearing it can hurt
the performance when it finally transmits out to fq@phy-dev.

The earlier patch added a skb->mono_delivery_time bit to
flag the skb->tstamp carrying the mono delivery_time.

This patch adds skb_clear_tstamp() helper which keeps
the mono delivery_time and clears everything else.

The delivery_time clearing will be postponed until the stack knows the
skb will be delivered locally. It will be done in a latter patch.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>


# 7980d2ea 09-Oct-2020 Julian Anastasov <ja@ssi.bg>

ipvs: clear skb->tstamp in forwarding path

fq qdisc requires tstamp to be cleared in forwarding path

Reported-by: Evgeny B <abt-admin@mail.ru>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=209427
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Fixes: 8203e2d844d3 ("net: clear skb->tstamp in forwarding paths")
Fixes: fb420d5d91c1 ("tcp/fq: move back to CLOCK_MONOTONIC")
Fixes: 80b14dee2bea ("net: Add a new socket option for a future transmit time.")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Reviewed-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>


# bd085ef6 21-Dec-2019 Hangbin Liu <liuhangbin@gmail.com>

net: add bool confirm_neigh parameter for dst_ops.update_pmtu

The MTU update code is supposed to be invoked in response to real
networking events that update the PMTU. In IPv6 PMTU update function
__ip6_rt_update_pmtu() we called dst_confirm_neigh() to update neighbor
confirmed time.

But for tunnel code, it will call pmtu before xmit, like:
- tnl_update_pmtu()
- skb_dst_update_pmtu()
- ip6_rt_update_pmtu()
- __ip6_rt_update_pmtu()
- dst_confirm_neigh()

If the tunnel remote dst mac address changed and we still do the neigh
confirm, we will not be able to update neigh cache and ping6 remote
will failed.

So for this ip_tunnel_xmit() case, _EVEN_ if the MTU is changed, we
should not be invoking dst_confirm_neigh() as we have no evidence
of successful two-way communication at this point.

On the other hand it is also important to keep the neigh reachability fresh
for TCP flows, so we cannot remove this dst_confirm_neigh() call.

To fix the issue, we have to add a new bool parameter for dst_ops.update_pmtu
to choose whether we should do neigh update or not. I will add the parameter
in this patch and set all the callers to true to comply with the previous
way, and fix the tunnel code one by one on later patches.

v5: No change.
v4: No change.
v3: Do not remove dst_confirm_neigh, but add a new bool parameter in
dst_ops.update_pmtu to control whether we should do neighbor confirm.
Also split the big patch to small ones for each area.
v2: Remove dst_confirm_neigh in __ip6_rt_update_pmtu.

Suggested-by: David Miller <davem@davemloft.net>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>


# c09b8970 29-Sep-2019 zhang kai <zhangkaiheb@126.com>

ipvs: no need to update skb route entry for local destination packets.

In the end of function __ip_vs_get_out_rt/__ip_vs_get_out_rt_v6,the
'local' variable is always zero.

Signed-off-by: zhang kai <zhangkaiheb@126.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>


# 895b5c9f 29-Sep-2019 Florian Westphal <fw@strlen.de>

netfilter: drop bridge nf reset from nf_reset

commit 174e23810cd31
("sk_buff: drop all skb extensions on free and skb scrubbing") made napi
recycle always drop skb extensions. The additional skb_ext_del() that is
performed via nf_reset on napi skb recycle is not needed anymore.

Most nf_reset() calls in the stack are there so queued skb won't block
'rmmod nf_conntrack' indefinitely.

This removes the skb_ext_del from nf_reset, and renames it to a more
fitting nf_reset_ct().

In a few selected places, add a call to skb_ext_reset to make sure that
no active extensions remain.

I am submitting this for "net", because we're still early in the release
cycle. The patch applies to net-next too, but I think the rename causes
needless divergence between those trees.

Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>


# 6f7b841b 01-Jul-2019 Vadim Fedorenko <vfedorenko@yandex-team.ru>

ipvs: allow tunneling with gre encapsulation

windows real servers can handle gre tunnels, this patch allows
gre encapsulation with the tunneling method, thereby letting ipvs
be load balancer for windows-based services

Signed-off-by: Vadim Fedorenko <vfedorenko@yandex-team.ru>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>


# 29930e31 29-May-2019 Jacky Hu <hengqing.hu@gmail.com>

ipvs: add checksum support for gue encapsulation

Add checksum support for gue encapsulation with the tun_flags parameter,
which could be one of the values below:
IP_VS_TUNNEL_ENCAP_FLAG_NOCSUM
IP_VS_TUNNEL_ENCAP_FLAG_CSUM
IP_VS_TUNNEL_ENCAP_FLAG_REMCSUM

Signed-off-by: Jacky Hu <hengqing.hu@gmail.com>
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>


# ec0974df 23-May-2019 Florian Westphal <fw@strlen.de>

netfilter: ipvs: prefer skb_ensure_writable

It does the same thing, use it instead so we can remove skb_make_writable.

Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>


# 2874c5fd 27-May-2019 Thomas Gleixner <tglx@linutronix.de>

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>


# 84c0d5e9 26-Mar-2019 Jacky Hu <hengqing.hu@gmail.com>

ipvs: allow tunneling with gue encapsulation

ipip packets are blocked in some public cloud environments, this patch
allows gue encapsulation with the tunneling method, which would make
tunneling working in those environments.

Signed-off-by: Jacky Hu <hengqing.hu@gmail.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>


# f25a9b85 16-Feb-2019 Andrea Claudi <aclaudi@redhat.com>

ipvs: change some data types from int to bool

Change the data type of the following variables from int to bool
across ipvs code:

- found
- loop
- need_full_dest
- need_full_svc
- payload_csum

Also change the following functions to use bool full_entry param
instead of int:

- ip_vs_genl_parse_dest()
- ip_vs_genl_parse_service()

This patch does not change any functionality but makes the source
code slightly easier to read.

Signed-off-by: Andrea Claudi <aclaudi@redhat.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>


# 6fcc02e3 02-Jun-2018 Julian Anastasov <ja@ssi.bg>

ipvs: fix check on xmit to non-local addresses

There is mistake in the rt_mode_allow_non_local assignment.
It should be used to check if sending to non-local addresses is
allowed, now it checks if local addresses are allowed.

As local addresses are allowed for most of the cases, the only
places that are affected are for traffic to transparent cache
servers:

- bypass connections when cache server is not available
- related ICMP in FORWARD hook when sent to cache server

Fixes: 4a4739d56b00 ("ipvs: Pull out crosses_local_route_boundary logic")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>


# bdb7cc64 16-Apr-2018 Stephen Suryaputra <ssuryaextr@gmail.com>

ipv6: Count interface receive statistics on the ingress netdev

The statistics such as InHdrErrors should be counted on the ingress
netdev rather than on the dev from the dst, which is the egress.

Signed-off-by: Stephen Suryaputra <ssuryaextr@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>


# b621129f 15-Feb-2017 Vadim Fedorenko <vfedorenko@yandex-team.ru>

netfilter: ipvs: full-functionality option for ECN encapsulation in tunnel

IPVS tunnel mode works as simple tunnel (see RFC 3168) copying ECN field
to outer header. That's result in packet drops on egress tunnels in case
the egress tunnel operates as ECN-capable with Full-functionality option
(like ip_tunnel and ip6_tunnel kernel modules), according to RFC 3168
section 9.1.1 recommendation.

This patch implements ECN full-functionality option into ipvs xmit code.

Cc: netdev@vger.kernel.org
Cc: lvs-devel@vger.kernel.org
Signed-off-by: Vadim Fedorenko <vfedorenko@yandex-team.ru>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>


# 0b35f603 18-Jul-2017 Taehee Yoo <ap420073@gmail.com>

netfilter: Remove duplicated rcu_read_lock.

This patch removes duplicate rcu_read_lock().

1. IPVS part:

According to Julian Anastasov's mention, contexts of ipvs are described
at: http://marc.info/?l=netfilter-devel&m=149562884514072&w=2, in summary:

- packet RX/TX: does not need locks because packets come from hooks.
- sync msg RX: backup server uses RCU locks while registering new
connections.
- ip_vs_ctl.c: configuration get/set, RCU locks needed.
- xt_ipvs.c: It is a netfilter match, running from hook context.

As result, rcu_read_lock and rcu_read_unlock can be removed from:

- ip_vs_core.c: all
- ip_vs_ctl.c:
- only from ip_vs_has_real_service
- ip_vs_ftp.c: all
- ip_vs_proto_sctp.c: all
- ip_vs_proto_tcp.c: all
- ip_vs_proto_udp.c: all
- ip_vs_xmit.c: all (contains only packet processing)

2. Netfilter part:

There are three types of functions that are guaranteed the rcu_read_lock().
First, as result, functions are only called by nf_hook():

- nf_conntrack_broadcast_help(), pptp_expectfn(), set_expected_rtp_rtcp().
- tcpmss_reverse_mtu(), tproxy_laddr4(), tproxy_laddr6().
- match_lookup_rt6(), check_hlist(), hashlimit_mt_common().
- xt_osf_match_packet().

Second, functions that caller already held the rcu_read_lock().
- destroy_conntrack(), ctnetlink_conntrack_event().
- ctnl_timeout_find_get(), nfqnl_nf_hook_drop().

Third, functions that are mixed with type1 and type2.

These functions are called by nf_hook() also these are called by
ordinary functions that already held the rcu_read_lock():

- __ctnetlink_glue_build(), ctnetlink_expect_event().
- ctnetlink_proto_size().

Applied files are below:

- nf_conntrack_broadcast.c, nf_conntrack_core.c, nf_conntrack_netlink.c.
- nf_conntrack_pptp.c, nf_conntrack_sip.c, nfnetlink_cttimeout.c.
- nfnetlink_queue.c, xt_TCPMSS.c, xt_TPROXY.c, xt_addrtype.c.
- xt_connlimit.c, xt_hashlimit.c, xt_osf.c

Detailed calltrace can be found at:
http://marc.info/?l=netfilter-devel&m=149667610710350&w=2

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>


# ab8bc7ed 14-Apr-2017 Florian Westphal <fw@strlen.de>

netfilter: remove nf_ct_is_untracked

This function is now obsolete and always returns false.
This change has no effect on generated code.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>


# 8d8e20e2 25-Oct-2016 Dwip Banerjee <dwip@linux.vnet.ibm.com>

ipvs: Decrement ttl

We decrement the IP ttl in all the modes in order to prevent infinite
route loops. The changes were done based on Julian Anastasov's
suggestions in a prior thread.

The ttl based check/discard and the actual decrement are done in
__ip_vs_get_out_rt() and in __ip_vs_get_out_rt_v6(), for the IPv6
case. decrement_ttl() implements the actual functionality for the
two cases.

Signed-off-by: Dwip Banerjee <dwip@linux.vnet.ibm.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>


# 7e13318d 18-May-2016 Tom Herbert <tom@herbertland.com>

net: define gso types for IPx over IPv4 and IPv6

This patch defines two new GSO definitions SKB_GSO_IPXIP4 and
SKB_GSO_IPXIP6 along with corresponding NETIF_F_GSO_IPXIP4 and
NETIF_F_GSO_IPXIP6. These are used to described IP in IP
tunnel and what the outer protocol is. The inner protocol
can be deduced from other GSO types (e.g. SKB_GSO_TCPV4 and
SKB_GSO_TCPV6). The GSO types of SKB_GSO_IPIP and SKB_GSO_SIT
are removed (these are both instances of SKB_GSO_IPXIP4).
SKB_GSO_IPXIP6 will be used when support for GSO with IP
encapsulation over IPv6 is added.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>


# aed069df 14-Apr-2016 Alexander Duyck <aduyck@mirantis.com>

ip_tunnel_core: iptunnel_handle_offloads returns int and doesn't free skb

This patch updates the IP tunnel core function iptunnel_handle_offloads so
that we return an int and do not free the skb inside the function. This
actually allows us to clean up several paths in several tunnels so that we
can free the skb at one point in the path without having to have a
secondary path if we are supporting tunnel offloads.

In addition it should resolve some double-free issues I have found in the
tunnels paths as I believe it is possible for us to end up triggering such
an event in the case of fou or gue.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>


# 64d4e343 27-Feb-2016 WANG Cong <xiyou.wangcong@gmail.com>

net: remove skb_sender_cpu_clear()

After commit 52bd2d62ce67 ("net: better skb->sender_cpu and skb->napi_id cohabitation")
skb_sender_cpu_clear() becomes empty and can be removed.

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


# 6fa79666 11-Feb-2016 Edward Cree <ecree@solarflare.com>

net: ip_tunnel: remove 'csum_help' argument to iptunnel_handle_offloads

All users now pass false, so we can remove it, and remove the code that
was conditional upon it.

Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>


# 33224b16 07-Oct-2015 Eric W. Biederman <ebiederm@xmission.com>

ipv4, ipv6: Pass net into ip_local_out and ip6_local_out

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


# 79288330 07-Oct-2015 Eric W. Biederman <ebiederm@xmission.com>

ipv6: Merge ip6_local_out and ip6_local_out_sk

Stop hidding the sk parameter with an inline helper function and make
all of the callers pass it, so that it is clear what the function is
doing.

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


# e2cb77db 07-Oct-2015 Eric W. Biederman <ebiederm@xmission.com>

ipv4: Merge ip_local_out and ip_local_out_sk

It is confusing and silly hiding a parameter so modify all of
the callers to pass in the appropriate socket or skb->sk if
no socket is known.

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


# 13206b6b 07-Oct-2015 Eric W. Biederman <ebiederm@xmission.com>

net: Pass net into dst_output and remove dst_output_okfn

Replace dst_output_okfn with dst_output

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


# 20868a40 21-Sep-2015 Eric W. Biederman <ebiederm@xmission.com>

ipvs: Pass ipvs into ensure_mtu_is adequate

This allows two different ways for computing/guessing net to be
removed from ensure_mtu_is_adequate.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>


# f5745f8a 21-Sep-2015 Eric W. Biederman <ebiederm@xmission.com>

ipvs: Pass ipvs into __ip_vs_get_out_rt_v6

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>


# ecfe87b8 21-Sep-2015 Eric W. Biederman <ebiederm@xmission.com>

ipvs: Pass ipvs into __ip_vs_get_out_rt

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>


# 361c3f52 21-Sep-2015 Eric W. Biederman <ebiederm@xmission.com>

ipvs: Better derivation of ipvs in ip_vs_tunnel_xmit

Don't use "net_ipvs(skb_net(skb))" as skb_net is a bad hack. Instead
use cp->ipvs and ipvs->net for the net.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>


# 58dbc6f2 21-Sep-2015 Eric W. Biederman <ebiederm@xmission.com>

ipvs: Store ipvs not net in struct ip_vs_conn

In practice struct netns_ipvs is as meaningful as struct net and more
useful as it holds the ipvs specific data. So store a pointer to
struct netns_ipvs.

Update the accesses of conn->net to access conn->ipvs->net instead.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>


# 0c4b51f0 15-Sep-2015 Eric W. Biederman <ebiederm@xmission.com>

netfilter: Pass net into okfn

This is immediately motivated by the bridge code that chains functions that
call into netfilter. Without passing net into the okfns the bridge code would
need to guess about the best expression for the network namespace to process
packets in.

As net is frequently one of the first things computed in continuation functions
after netfilter has done it's job passing in the desired network namespace is in
many cases a code simplification.

To support this change the function dst_output_okfn is introduced to
simplify passing dst_output as an okfn. For the moment dst_output_okfn
just silently drops the struct net.

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


# 29a26a56 15-Sep-2015 Eric W. Biederman <ebiederm@xmission.com>

netfilter: Pass struct net into the netfilter hooks

Pass a network namespace parameter into the netfilter hooks. At the
call site of the netfilter hooks the path a packet is taking through
the network stack is well known which allows the network namespace to
be easily and reliabily.

This allows the replacement of magic code like
"dev_net(state->in?:state->out)" that appears at the start of most
netfilter hooks with "state->net".

In almost all cases the network namespace passed in is derived
from the first network device passed in, guaranteeing those
paths will not see any changes in practice.

The exceptions are:
xfrm/xfrm_output.c:xfrm_output_resume() xs_net(skb_dst(skb)->xfrm)
ipvs/ip_vs_xmit.c:ip_vs_nat_send_or_cont() ip_vs_conn_net(cp)
ipvs/ip_vs_xmit.c:ip_vs_send_or_cont() ip_vs_conn_net(cp)
ipv4/raw.c:raw_send_hdrinc() sock_net(sk)
ipv6/ip6_output.c:ip6_xmit() sock_net(sk)
ipv6/ndisc.c:ndisc_send_skb() dev_net(skb->dev) not dev_net(dst->dev)
ipv6/raw.c:raw6_send_hdrinc() sock_net(sk)
br_netfilter_hooks.c:br_nf_pre_routing_finish() dev_net(skb->dev) before skb->dev is set to nf_bridge->physindev

In all cases these exceptions seem to be a better expression for the
network namespace the packet is being processed in then the historic
"dev_net(in?in:out)". I am documenting them in case something odd
pops up and someone starts trying to track down what happened.

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


# 5a70649e 15-Sep-2015 Eric W. Biederman <ebiederm@xmission.com>

net: Merge dst_output and dst_output_sk

Add a sock paramter to dst_output making dst_output_sk superfluous.
Add a skb->sk parameter to all of the callers of dst_output
Have the callers of dst_output_sk call dst_output.

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


# 89621f31 26-Aug-2015 Alex Gartrell <agartrell@fb.com>

ipvs: ensure that ICMP cannot be sent in reply to ICMP

Check the header for icmp before sending a PACKET_TOO_BIG

Signed-off-by: Alex Gartrell <agartrell@fb.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>


# 3481894f 26-Aug-2015 Alex Gartrell <agartrell@fb.com>

ipvs: Use outer header in ip_vs_bypass_xmit_v6

The ip_vs_iphdr may refer to an internal header, so use the outer one
instead.

Signed-off-by: Alex Gartrell <agartrell@fb.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>


# b0e010c5 26-Aug-2015 Alex Gartrell <agartrell@fb.com>

ipvs: replace ip_vs_fill_ip4hdr with ip_vs_fill_iph_skb_off

This removes some duplicated code and makes the ICMPv6 path look more like
the ICMP path.

Signed-off-by: Alex Gartrell <agartrell@fb.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>


# e3895c03 09-Jul-2015 Julian Anastasov <ja@ssi.bg>

ipvs: call skb_sender_cpu_clear

Reset XPS's sender_cpu on forwarding.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Fixes: 2bd82484bb4c ("xps: fix xps for stacked devices")
Signed-off-by: Simon Horman <horms@verge.net.au>


# 71563f34 05-Jul-2015 Alex Gartrell <agartrell@fb.com>

ipvs: skb_orphan in case of forwarding

It is possible that we bind against a local socket in early_demux when we
are actually going to want to forward it. In this case, the socket serves
no purpose and only serves to confuse things (particularly functions which
implicitly expect sk_fullsock to be true, like ip_local_out).
Additionally, skb_set_owner_w is totally broken for non full-socks.

Signed-off-by: Alex Gartrell <agartrell@fb.com>
Fixes: 41063e9dd119 ("ipv4: Early TCP socket demux.")
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>


# 4754957f 27-Jun-2015 Julian Anastasov <ja@ssi.bg>

ipvs: do not use random local source address for tunnels

Michael Vallaly reports about wrong source address used
in rare cases for tunneled traffic. Looks like
__ip_vs_get_out_rt in 3.10+ is providing uninitialized
dest_dst->dst_saddr.ip because ip_vs_dest_dst_alloc uses
kmalloc. While we retry after seeing EINVAL from routing
for data that does not look like valid local address, it
still succeeded when this memory was previously used from
other dests and with different local addresses. As result,
we can use valid local address that is not suitable for
our real server.

Fix it by providing 0.0.0.0 every time our cache is refreshed.
By this way we will get preferred source address from routing.

Reported-by: Michael Vallaly <lvs@nolatency.com>
Fixes: 026ace060dfe ("ipvs: optimize dst usage for real server")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>


# 326bf17e 26-Jun-2015 Alex Gartrell <agartrell@fb.com>

ipvs: fix ipv6 route unreach panic

Previously there was a trivial panic

unshare -n /bin/bash <<EOF
ip addr add dev lo face::1/128
ipvsadm -A -t [face::1]:15213
ipvsadm -a -t [face::1]:15213 -r b00c::1
echo boom | nc face::1 15213
EOF

This patch allows us to replicate the net logic above and simply capture
the skb_dst(skb)->dev and use that for the purpose of the invocation.

Signed-off-by: Alex Gartrell <agartrell@fb.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>


# 48e8aa6e 22-May-2015 Martin KaFai Lau <kafai@fb.com>

ipv6: Set FLOWI_FLAG_KNOWN_NH at flowi6_flags

The neighbor look-up used to depend on the rt6i_gateway (if
there is a gateway) or the rt6i_dst (if it is a RTF_CACHE clone)
as the nexthop address. Note that rt6i_dst is set to fl6->daddr
for the RTF_CACHE clone where fl6->daddr is the one used to do
the route look-up.

Now, we only create RTF_CACHE clone after encountering exception.
When doing the neighbor look-up with a route that is neither a gateway
nor a RTF_CACHE clone, the daddr in skb will be used as the nexthop.

In some cases, the daddr in skb is not the one used to do
the route look-up. One example is in ip_vs_dr_xmit_v6() where the
real nexthop server address is different from the one in the skb.

This patch is going to follow the IPv4 approach and ask the
ip6_pol_route() callers to set the FLOWI_FLAG_KNOWN_NH properly.

In the next patch, ip6_pol_route() will honor the FLOWI_FLAG_KNOWN_NH
and create a RTF_CACHE clone.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Tested-by: Julian Anastasov <ja@ssi.bg>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>


# b197df4f 22-May-2015 Martin KaFai Lau <kafai@fb.com>

ipv6: Add rt6_get_cookie() function

Instead of doing the rt6->rt6i_node check whenever we need
to get the route's cookie. Refactor it into rt6_get_cookie().
It is a prep work to handle FLOWI_FLAG_KNOWN_NH and also
percpu rt6_info later.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>


# fd0273d7 22-May-2015 Martin KaFai Lau <kafai@fb.com>

ipv6: Remove external dependency on rt6i_dst and rt6i_src

This patch removes the assumptions that the returned rt is always
a RTF_CACHE entry with the rt6i_dst and rt6i_src containing the
destination and source address. The dst and src can be recovered from
the calling site.

We may consider to rename (rt6i_dst, rt6i_src) to
(rt6i_key_dst, rt6i_key_src) later.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>


# 7026b1dd 05-Apr-2015 David Miller <davem@davemloft.net>

netfilter: Pass socket pointer down through okfn().

On the output paths in particular, we have to sometimes deal with two
socket contexts. First, and usually skb->sk, is the local socket that
generated the frame.

And second, is potentially the socket used to control a tunneling
socket, such as one the encapsulates using UDP.

We do not want to disassociate skb->sk when encapsulating in order
to fix this, because that would break socket memory accounting.

The most extreme case where this can cause huge problems is an
AF_PACKET socket transmitting over a vxlan device. We hit code
paths doing checks that assume they are dealing with an ipv4
socket, but are actually operating upon the AF_PACKET one.

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


# b6a7719a 25-Mar-2015 Hannes Frederic Sowa <hannes@stressinduktion.org>

ipv4: hash net ptr into fragmentation bucket selection

As namespaces are sometimes used with overlapping ip address ranges,
we should also use the namespace as input to the hash to select the ip
fragmentation counter bucket.

Cc: Eric Dumazet <edumazet@google.com>
Cc: Flavio Leitner <fbl@redhat.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>


# a8399231 16-Mar-2015 Eric Dumazet <edumazet@google.com>

netfilter: use sk_fullsock() helper

Upcoming request sockets have TCP_NEW_SYN_RECV state and should
be special cased a bit like TCP_TIME_WAIT sockets.

Signed-off-by; Eric Dumazet <edumazet@google.com>

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


# dbfc4fb7 06-Dec-2014 Hannes Frederic Sowa <hannes@stressinduktion.org>

dst: no need to take reference on DST_NOCACHE dsts

Since commit f8864972126899 ("ipv4: fix dst race in sk_dst_get()")
DST_NOCACHE dst_entries get freed by RCU. So there is no need to get a
reference on them when we are in rcu protected sections.

Cc: Eric Dumazet <edumazet@google.com>
Cc: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Reviewed-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>


# 50656d9d 04-Nov-2014 Calvin Owens <calvinowens@fb.com>

ipvs: Keep skb->sk when allocating headroom on tunnel xmit

ip_vs_prepare_tunneled_skb() ignores ->sk when allocating a new
skb, either unconditionally setting ->sk to NULL or allowing
the uninitialized ->sk from a newly allocated skb to leak through
to the caller.

This patch properly copies ->sk and increments its reference count.

Signed-off-by: Calvin Owens <calvinowens@fb.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>


# d7701089 06-Oct-2014 Alex Gartrell <agartrell@fb.com>

ipvs: remove unnecessary assignment in __ip_vs_get_out_rt

It is a precondition of the function that daddr be equal to dest->addr.ip
if dest is non-NULL, so this additional assignment is just confusing for
stupid engineers like me.

Signed-off-by: Alex Gartrell <agartrell@fb.com>
Signed-off-by: Simon Horman <horms@verge.net.au>


# 3d53666b 06-Oct-2014 Alex Gartrell <agartrell@fb.com>

ipvs: Avoid null-pointer deref in debug code

Use daddr instead of reaching into dest.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alex Gartrell <agartrell@fb.com>
Signed-off-by: Simon Horman <horms@verge.net.au>


# 8052ba29 09-Sep-2014 Alex Gartrell <agartrell@fb.com>

ipvs: support ipv4 in ipv6 and ipv6 in ipv4 tunnel forwarding

Pull the common logic for preparing an skb to prepend the header into a
single function and then set fields such that they can be used in either
case (generalize tos and tclass to dscp, hop_limit and ttl to ttl, etc)

Signed-off-by: Alex Gartrell <agartrell@fb.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>


# c63e4de2 09-Sep-2014 Alex Gartrell <agartrell@fb.com>

ipvs: Add generic ensure_mtu_is_adequate to handle mixed pools

The out_rt functions check to see if the mtu is large enough for the packet
and, if not, send icmp messages (TOOBIG or DEST_UNREACH) to the source and
bail out. We needed the ability to send ICMP from the out_rt_v6 function
and DEST_UNREACH from the out_rt function, so we just pulled it out into a
common function.

Signed-off-by: Alex Gartrell <agartrell@fb.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>


# 919aa0b2 09-Sep-2014 Alex Gartrell <agartrell@fb.com>

ipvs: Pull out update_pmtu code

Another step toward heterogeneous pools, this removes another piece of
functionality currently specific to each address family type.

Signed-off-by: Alex Gartrell <agartrell@fb.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>


# 4a4739d5 09-Sep-2014 Alex Gartrell <agartrell@fb.com>

ipvs: Pull out crosses_local_route_boundary logic

This logic is repeated in both out_rt functions so it was redundant.
Additionally, we'll need to be able to do checks to route v4 to v6 and vice
versa in order to deal with heterogeneous pools.

This patch also updates the callsites to add an additional parameter to the
out route functions.

Signed-off-by: Alex Gartrell <agartrell@fb.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>


# ea1d5d77 01-Aug-2014 Julian Anastasov <ja@ssi.bg>

ipvs: properly declare tunnel encapsulation

The tunneling method should properly use tunnel encapsulation.
Fixes problem with CHECKSUM_PARTIAL packets when TCP/UDP csum
offload is supported.

Thanks to Alex Gartrell for reporting the problem, providing
solution and for all suggestions.

Reported-by: Alex Gartrell <agartrell@fb.com>
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Alex Gartrell <agartrell@fb.com>
Signed-off-by: Simon Horman <horms@verge.net.au>


# 76f084bc 16-Jul-2014 Alex Gartrell <agartrell@fb.com>

ipvs: Maintain all DSCP and ECN bits for ipv6 tun forwarding

Previously, only the four high bits of the tclass were maintained in the
ipv6 case. This matches the behavior of ipv4, though whether or not we
should reflect ECN bits may be up for debate.

Signed-off-by: Alex Gartrell <agartrell@fb.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>


# 73f156a6 02-Jun-2014 Eric Dumazet <edumazet@google.com>

inetpeer: get rid of ip_id_count

Ideally, we would need to generate IP ID using a per destination IP
generator.

linux kernels used inet_peer cache for this purpose, but this had a huge
cost on servers disabling MTU discovery.

1) each inet_peer struct consumes 192 bytes

2) inetpeer cache uses a binary tree of inet_peer structs,
with a nominal size of ~66000 elements under load.

3) lookups in this tree are hitting a lot of cache lines, as tree depth
is about 20.

4) If server deals with many tcp flows, we have a high probability of
not finding the inet_peer, allocating a fresh one, inserting it in
the tree with same initial ip_id_count, (cf secure_ip_id())

5) We garbage collect inet_peer aggressively.

IP ID generation do not have to be 'perfect'

Goal is trying to avoid duplicates in a short period of time,
so that reassembly units have a chance to complete reassembly of
fragments belonging to one message before receiving other fragments
with a recycled ID.

We simply use an array of generators, and a Jenkin hash using the dst IP
as a key.

ipv6_select_ident() is put back into net/ipv6/ip6_output.c where it
belongs (it is only used from this file)

secure_ip_id() and secure_ipv6_id() no longer are needed.

Rename ip_select_ident_more() to ip_select_ident_segs() to avoid
unnecessary decrement/increment of the number of segments.

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


# 60ff7467 04-May-2014 WANG Cong <xiyou.wangcong@gmail.com>

net: rename local_df to ignore_df

As suggested by several people, rename local_df to ignore_df,
since it means "ignore df bit if it is set".

Cc: Maciej Żenczykowski <maze@google.com>
Cc: Florian Westphal <fw@strlen.de>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>


# 703133de 18-Sep-2013 Ansis Atteka <aatteka@nicira.com>

ip: generate unique IP identificator if local fragmentation is allowed

If local fragmentation is allowed, then ip_select_ident() and
ip_select_ident_more() need to generate unique IDs to ensure
correct defragmentation on the peer.

For example, if IPsec (tunnel mode) has to encrypt large skbs
that have local_df bit set, then all IP fragments that belonged
to different ESP datagrams would have used the same identificator.
If one of these IP fragments would get lost or reordered, then
peer could possibly stitch together wrong IP fragments that did
not belong to the same datagram. This would lead to a packet loss
or data corruption.

Signed-off-by: Ansis Atteka <aatteka@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>


# ac69269a 22-Mar-2013 Julian Anastasov <ja@ssi.bg>

ipvs: do not disable bh for long time

We used a global BH disable in LOCAL_OUT hook.
Add _bh suffix to all places that need it and remove
the disabling from LOCAL_OUT and sync code.

Functions like ip_defrag need protection from
BH, so add it. As for nf_nat_mangle_tcp_packet, it needs
RCU lock.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>


# 026ace06 21-Mar-2013 Julian Anastasov <ja@ssi.bg>

ipvs: optimize dst usage for real server

Currently when forwarding requests to real servers
we use dst_lock and atomic operations when cloning the
dst_cache value. As the dst_cache value does not change
most of the time it is better to use RCU and to lock
dst_lock only when we need to replace the obsoleted dst.
For this to work we keep dst_cache in new structure protected
by RCU. For packets to remote real servers we will use noref
version of dst_cache, it will be valid while we are in RCU
read-side critical section because now dst_release for replaced
dsts will be invoked after the grace period. Packets to
local real servers that are passed to local stack with
NF_ACCEPT need a dst clone.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off by: Hans Schillstrom <hans@schillstrom.com>
Signed-off-by: Simon Horman <horms@verge.net.au>


# 4115ded1 21-Mar-2013 Julian Anastasov <ja@ssi.bg>

ipvs: consolidate all dst checks on transmit in one place

Consolidate the PMTU checks, ICMP sending and
skb_dst modification in __ip_vs_get_out_rt and
__ip_vs_get_out_rt_v6. Now skb_dst is changed early
to simplify the transmitters.

Make sure update_pmtu is called only for local clients.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off by: Hans Schillstrom <hans@schillstrom.com>
Signed-off-by: Simon Horman <horms@verge.net.au>


# f11cb2c2 21-Mar-2013 Julian Anastasov <ja@ssi.bg>

ipvs: do not use skb_share_check

We run in contexts like ip_rcv, ipv6_rcv, br_handle_frame,
do not expect shared skbs.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off by: Hans Schillstrom <hans@schillstrom.com>
Signed-off-by: Simon Horman <horms@verge.net.au>


# 183dce55 21-Mar-2013 Julian Anastasov <ja@ssi.bg>

ipvs: no need to reroute anymore on DNAT over loopback

After commit 70e7341673 (ipv4: Show that ip_send_reply()
is purely unicast routine.) we do not need to reroute DNAT-ed
traffic over loopback because reply uses iph daddr and not
rt_spec_dst.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off by: Hans Schillstrom <hans@schillstrom.com>
Signed-off-by: Simon Horman <horms@verge.net.au>


# d1deae4d 21-Mar-2013 Julian Anastasov <ja@ssi.bg>

ipvs: rename functions related to dst_cache reset

Move and give better names to two functions:

- ip_vs_dst_reset to __ip_vs_dst_cache_reset
- __ip_vs_dev_reset to ip_vs_forget_dev

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off by: Hans Schillstrom <hans@schillstrom.com>
Signed-off-by: Simon Horman <horms@verge.net.au>


# b8abdf09 21-Mar-2013 Julian Anastasov <ja@ssi.bg>

ipvs: convert the IP_VS_XMIT macros to functions

It was a bad idea to hide return statements in macros.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off by: Hans Schillstrom <hans@schillstrom.com>
Signed-off-by: Simon Horman <horms@verge.net.au>


# c90558da 21-Mar-2013 Julian Anastasov <ja@ssi.bg>

ipvs: avoid routing by TOS for real server

Avoid replacing the cached route for real server
on every packet with different TOS. I doubt that routing
by TOS for real server is used at all, so we should be
better with such optimization.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off by: Hans Schillstrom <hans@schillstrom.com>
Signed-off-by: Simon Horman <horms@verge.net.au>


# 05b4b065 25-Oct-2012 Alan Cox <alan@linux.intel.com>

ipvs: remove silly double assignment

I don't even want to think what the C spec says for this 8)

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>


# ad4d3ef8 08-Oct-2012 Julian Anastasov <ja@ssi.bg>

ipvs: fix ARP resolving for direct routing mode

After the change "Make neigh lookups directly in output packet path"
(commit a263b30936) IPVS can not reach the real server for DR mode
because we resolve the destination address from IP header, not from
route neighbour. Use the new FLOWI_FLAG_KNOWN_NH flag to request
output routes with known nexthop, so that it has preference
on resolving.

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


# d4383f04 26-Sep-2012 Jesper Dangaard Brouer <brouer@redhat.com>

ipvs: API change to avoid rescan of IPv6 exthdr

Reduce the number of times we scan/skip the IPv6 exthdrs.

This patch contains a lot of API changes. This is done, to avoid
repeating the scan of finding the IPv6 headers, via ipv6_find_hdr(),
which is called by ip_vs_fill_iph_skb().

Finding the IPv6 headers is done as early as possible, and passed on
as a pointer "struct ip_vs_iphdr *" to the affected functions.

This patch reduce/removes 19 calls to ip_vs_fill_iph_skb().

Notice, I have choosen, not to change the API of function
pointer "(*schedule)" (in struct ip_vs_scheduler) as it can be
used by external schedulers, via {un,}register_ip_vs_scheduler.
Only 4 out of 10 schedulers use info from ip_vs_iphdr*, and when
they do, they are only interested in iph->{s,d}addr.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>


# 2f74713d 26-Sep-2012 Jesper Dangaard Brouer <brouer@redhat.com>

ipvs: Complete IPv6 fragment handling for IPVS

IPVS now supports fragmented packets, with support from nf_conntrack_reasm.c

Based on patch from: Hans Schillstrom.

IPVS do like conntrack i.e. use the skb->nfct_reasm
(i.e. when all fragments is collected, nf_ct_frag6_output()
starts a "re-play" of all fragments into the interrupted
PREROUTING chain at prio -399 (NF_IP6_PRI_CONNTRACK_DEFRAG+1)
with nfct_reasm pointing to the assembled packet.)

Notice, module nf_defrag_ipv6 must be loaded for this to work.
Report unhandled fragments, and recommend user to load nf_defrag_ipv6.

To handle fw-mark for fragments. Add a new IPVS hook into prerouting
chain at prio -99 (NF_IP6_PRI_NAT_DST+1) to catch fragments, and copy
fw-mark info from the first packet with an upper layer header.

IPv6 fragment handling should be the last thing on the IPVS IPv6
missing support list.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Hans Schillstrom <hans@schillstrom.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>


# 63dca2c0 26-Sep-2012 Jesper Dangaard Brouer <brouer@redhat.com>

ipvs: Fix faulty IPv6 extension header handling in IPVS

IPv6 packets can contain extension headers, thus its wrong to assume
that the transport/upper-layer header, starts right after (struct
ipv6hdr) the IPv6 header. IPVS uses this false assumption, and will
write SNAT & DNAT modifications at a fixed pos which will corrupt the
message.

To fix this, proper header position must be found before modifying
packets. Introducing ip_vs_fill_iph_skb(), which uses ipv6_find_hdr()
to skip the exthdrs. It finds (1) the transport header offset, (2) the
protocol, and (3) detects if the packet is a fragment.

Note, that fragments in IPv6 is represented via an exthdr. Thus, this
is detected while skipping through the exthdrs.

This patch depends on commit 84018f55a:
"netfilter: ip6_tables: add flags parameter to ipv6_find_hdr()"
This also adds a dependency to ip6_tables.

Originally based on patch from: Hans Schillstrom

kABI notes:
Changing struct ip_vs_iphdr is a potential minor kABI breaker,
because external modules can be compiled with another version of
this struct. This should not matter, as they would most-likely
be using a compiled-in version of ip_vs_fill_iphdr(). When
recompiled, they will notice ip_vs_fill_iphdr() no longer exists,
and they have to used ip_vs_fill_iph_skb() instead.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>


# 120b9c14 26-Sep-2012 Jesper Dangaard Brouer <brouer@redhat.com>

ipvs: Trivial changes, use compressed IPv6 address in output

Have not converted the proc file output to compressed IPv6 addresses.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>


# 4cdd3408 26-Aug-2012 Patrick McHardy <kaber@trash.net>

netfilter: nf_conntrack_ipv6: improve fragmentation handling

The IPv6 conntrack fragmentation currently has a couple of shortcomings.
Fragmentes are collected in PREROUTING/OUTPUT, are defragmented, the
defragmented packet is then passed to conntrack, the resulting conntrack
information is attached to each original fragment and the fragments then
continue their way through the stack.

Helper invocation occurs in the POSTROUTING hook, at which point only
the original fragments are available. The result of this is that
fragmented packets are never passed to helpers.

This patch improves the situation in the following way:

- If a reassembled packet belongs to a connection that has a helper
assigned, the reassembled packet is passed through the stack instead
of the original fragments.

- During defragmentation, the largest received fragment size is stored.
On output, the packet is refragmented if required. If the largest
received fragment size exceeds the outgoing MTU, a "packet too big"
message is generated, thus behaving as if the original fragments
were passed through the stack from an outside point of view.

- The ipv6_helper() hook function can't receive fragments anymore for
connections using a helper, so it is switched to use ipv6_skip_exthdr()
instead of the netfilter specific nf_ct_ipv6_skip_exthdr() and the
reassembled packets are passed to connection tracking helpers.

The result of this is that we can properly track fragmented packets, but
still generate ICMPv6 Packet too big messages if we would have before.

This patch is also required as a precondition for IPv6 NAT, where NAT
helpers might enlarge packets up to a point that they require
fragmentation. In that case we can't generate Packet too big messages
since the proper MTU can't be calculated in all cases (f.i. when
changing textual representation of a variable amount of addresses),
so the packet is transparently fragmented iff the original packet or
fragments would have fit the outgoing MTU.

IPVS parts by Jesper Dangaard Brouer <brouer@redhat.com>.

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


# 590e3f79 28-Aug-2012 Jesper Dangaard Brouer <brouer@redhat.com>

ipvs: IPv6 MTU checking cleanup and bugfix

Cleaning up the IPv6 MTU checking in the IPVS xmit code, by using
a common helper function __mtu_check_toobig_v6().

The MTU check for tunnel mode can also use this helper as
ntohs(old_iph->payload_len) + sizeof(struct ipv6hdr) is qual to
skb->len. And the 'mtu' variable have been adjusted before
calling helper.

Notice, this also fixes a bug, as the the MTU check in ip_vs_dr_xmit_v6()
were missing a check for skb_is_gso().

This bug e.g. caused issues for KVM IPVS setups, where different
Segmentation Offloading techniques are utilized, between guests,
via the virtio driver. This resulted in very bad performance,
due to the ICMPv6 "too big" messages didn't affect the sender.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>


# 3654e611 20-Jul-2012 Julian Anastasov <ja@ssi.bg>

ipvs: add pmtu_disc option to disable IP DF for TUN packets

Disabling PMTU discovery can increase the output packet
rate but some users have enough resources and prefer to fragment
than to drop traffic. By default, we copy the DF bit but if
pmtu_disc is disabled we do not send FRAG_NEEDED messages anymore.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>


# f2edb9f7 20-Jul-2012 Julian Anastasov <ja@ssi.bg>

ipvs: implement passive PMTUD for IPIP packets

IPVS is missing the logic to update PMTU in routing
for its IPIP packets. We monitor the dst_mtu and can return
FRAG_NEEDED messages but if the tunneled packets get ICMP
error we can not rely on other traffic to save the lowest
MTU.

The following patch adds ICMP handling for IPIP
packets in incoming direction, from some remote host to
our local IP used as saddr in the outer header. By this
way we can forward any related ICMP traffic if it is for IPVS
TUN connection. For the special case of PMTUD we update the
routing and if client requested DF we can forward the
error.

To properly update the routing we have to bind
the cached route (dest->dst_cache) to the selected saddr
because ipv4_update_pmtu uses saddr for dst lookup.
Add IP_VS_RT_MODE_CONNECT flag to force such binding with
second route.

Update ip_vs_tunnel_xmit to provide IP_VS_RT_MODE_CONNECT
and change the code to copy DF. For now we prefer not to
force PMTU discovery (outer DF=1) because we don't have
configuration option to enable or disable PMTUD. As we
do not keep any packets to resend, we prefer not to
play games with packets without DF bit because the sender
is not informed when they are rejected.

Also, change ops->update_pmtu to be called only
for local clients because there is no point to update
MTU for input routes, in our case skb->dst->dev is lo.
It seems the code is copied from ipip.c where the skb
dst points to tunnel device.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>


# 6700c270 17-Jul-2012 David S. Miller <davem@davemloft.net>

net: Pass optional SKB and SK arguments to dst_ops->{update_pmtu,redirect}()

This will be used so that we can compose a full flow key.

Even though we have a route in this context, we need more. In the
future the routes will be without destination address, source address,
etc. keying. One ipv4 route will cover entire subnets, etc.

In this environment we have to have a way to possess persistent storage
for redirects and PMTU information. This persistent storage will exist
in the FIB tables, and that's why we'll need to be able to rebuild a
full lookup flow key here. Using that flow key will do a fib_lookup()
and create/update the persistent entry.

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


# 5d0ba55b 03-Jun-2012 Eric Dumazet <edumazet@google.com>

net: use consume_skb() in place of kfree_skb()

Remove some dropwatch/drop_monitor false positives.

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


# d1918542 28-Dec-2011 David S. Miller <davem@davemloft.net>

ipv6: Kill rt6i_dev and rt6i_expires defines.

It just obscures that the netdevice pointer and the expires value are
implemented in the dst_entry sub-object of the ipv6 route.

And it makes grepping for dst_entry member uses much harder too.

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


# c0cd1156 11-Dec-2011 Igor Maravić <igorm@etf.rs>

net:netfilter: use IS_ENABLED

Use IS_ENABLED(CONFIG_FOO)
instead of defined(CONFIG_FOO) || defined (CONFIG_FOO_MODULE)

Signed-off-by: Igor Maravić <igorm@etf.rs>
Signed-off-by: David S. Miller <davem@davemloft.net>


# 4e3fd7a0 20-Nov-2011 Alexey Dobriyan <adobriyan@gmail.com>

net: remove ipv6_addr_copy()

C assignment can handle struct in6_addr copying.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>


# 3c2de2ae 15-Sep-2011 Simon Horman <horms@verge.net.au>

ipvs: Remove unused parameter from ip_vs_confirm_conntrack()

Acked-by: Julian Anastasov <ja@ssi.bg>
Acked-by Hans Schillstrom <hans@schillstrom.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>


# c92f5ca2 09-May-2011 Julian Anastasov <ja@ssi.bg>

ipvs: Remove all remaining references to rt->rt_{src,dst}

Remove all remaining references to rt->rt_{src,dst}
by using dest->dst_saddr to cache saddr (used for TUN mode).
For ICMP in FORWARD hook just restrict the rt_mode for NAT
to disable LOCALNODE. All other modes do not allow
IP_VS_RT_MODE_RDR, so we should be safe with the ICMP
forwarding. Using cp->daddr as replacement for rt_dst
is safe for all modes except BYPASS, even when cp->dest is
NULL because it is cp->daddr that is used to assign cp->dest
for sync-ed connections.

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


# 44e3125c 09-May-2011 David S. Miller <davem@davemloft.net>

ipvs: Eliminate rt->rt_dst usage in __ip_vs_get_out_rt().

We can simply track what destination address is used based upon which
code block is taken at the top of the function.

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


# e58b3442 12-May-2011 David S. Miller <davem@davemloft.net>

ipvs: Use IP_VS_RT_MODE_* instead of magic constants.

[ Add some cases I missed, from Julian Anastasov ]

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


# 4c9483b2 12-Mar-2011 David S. Miller <davem@davemloft.net>

ipv6: Convert to use flowi6 where applicable.

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


# 9d6ec938 11-Mar-2011 David S. Miller <davem@davemloft.net>

ipv4: Use flowi4 in public route lookup interfaces.

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


# 1d28f42c 11-Mar-2011 David S. Miller <davem@davemloft.net>

net: Put flowi_* prefix on AF independent members of struct flowi

I intend to turn struct flowi into a union of AF specific flowi
structs. There will be a common structure that each variant includes
first, much like struct sock_common.

This is the first step to move in that direction.

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


# 78fbfd8a 11-Mar-2011 David S. Miller <davem@davemloft.net>

ipv4: Create and use route lookup helpers.

The idea here is this minimizes the number of places one has to edit
in order to make changes to how flows are defined and used.

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


# b23dd4fe 02-Mar-2011 David S. Miller <davem@davemloft.net>

ipv4: Make output route lookup return rtable directly.

Instead of on the stack.

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


# 452edd59 02-Mar-2011 David S. Miller <davem@davemloft.net>

xfrm: Return dst directly from xfrm_lookup()

Instead of on the stack.

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


# 17a8f8e3 23-Feb-2011 Changli Gao <xiaosuo@gmail.com>

ipvs: use enum to instead of magic numbers

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: Simon Horman <horms@verge.net.au>


# 5811662b 12-Nov-2010 Changli Gao <xiaosuo@gmail.com>

net: use the macros defined for the members of flowi

Use the macros defined for the members of flowi to clean the code up.

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>


# 8f1b03a4 08-Nov-2010 Simon Horman <horms@verge.net.au>

ipvs: allow transmit of GRO aggregated skbs

Attempt at allowing LVS to transmit skbs of greater than MTU length that
have been aggregated by GRO and can thus be deaggregated by GSO.

Cc: Julian Anastasov <ja@ssi.bg>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Simon Horman <horms@verge.net.au>


# a333e2ec 15-Nov-2010 Eric Dumazet <eric.dumazet@gmail.com>

ipvs: remove shadow rt variable

Remove a sparse warning about rt variable.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Simon Horman <horms@verge.net.au>


# c7537967 11-Nov-2010 David S. Miller <davem@davemloft.net>

ipv4: Make rt->fl.iif tests lest obscure.

When we test rt->fl.iif against zero, we're seeing if it's
an output or an input route.

Make that explicit with some helper functions.

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


# 0d79641a 17-Oct-2010 Julian Anastasov <ja@ssi.bg>

ipvs: provide address family for debugging

As skb->protocol is not valid in LOCAL_OUT add
parameter for address family in packet debugging functions.
Even if ports are not present in AH and ESP change them to
use ip_vs_tcpudp_debug_packet to show at least valid addresses
as before. This patch removes the last user of skb->protocol
in IPVS.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>


# cb59155f 17-Oct-2010 Julian Anastasov <ja@ssi.bg>

ipvs: changes for local client

This patch deals with local client processing.

Prefer LOCAL_OUT hook for scheduling connections from
local clients. LOCAL_IN is still supported if the packets are
not marked as processed in LOCAL_OUT. The idea to process
requests in LOCAL_OUT is to alter conntrack reply before
it is confirmed at POST_ROUTING. If the local requests are
processed in LOCAL_IN the conntrack can not be updated
and matching by state is impossible.

Add the following handlers:

- ip_vs_reply[46] at LOCAL_IN:99 to process replies from
remote real servers to local clients. Now when both
replies from remote real servers (ip_vs_reply*) and
local real servers (ip_vs_local_reply*) are handled
it is safe to remove the conn_out_get call from ip_vs_in
because it does not support related ICMP packets.

- ip_vs_local_request[46] at LOCAL_OUT:-98 to process
requests from local client

Handling in LOCAL_OUT causes some changes:

- as skb->dev, skb->protocol and skb->pkt_type are not defined
in LOCAL_OUT make sure we set skb->dev before calling icmpv6_send,
prefer skb_dst(skb) for struct net and remove the skb->protocol
checks from TUN transmitters.

[ horms@verge.net.au: removed trailing whitespace ]
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>


# fc604767 17-Oct-2010 Julian Anastasov <ja@ssi.bg>

ipvs: changes for local real server

This patch deals with local real servers:

- Add support for DNAT to local address (different real server port).
It needs ip_vs_out hook in LOCAL_OUT for both families because
skb->protocol is not set for locally generated packets and can not
be used to set 'af'.

- Skip packets in ip_vs_in marked with skb->ipvs_property because
ip_vs_out processing can be executed in LOCAL_OUT but we still
have the conn_out_get check in ip_vs_in.

- Ignore packets with inet->nodefrag from local stack

- Require skb_dst(skb) != NULL because we use it to get struct net

- Add support for changing the route to local IPv4 stack after DNAT
depending on the source address type. Local client sets output
route and the remote client sets input route. It looks like
IPv6 does not need such rerouting because the replies use
addresses from initial incoming header, not from skb route.

- All transmitters now have strict checks for the destination
address type: redirect from non-local address to local real
server requires NAT method, local address can not be used as
source address when talking to remote real server.

- Now LOCALNODE is not set explicitly as forwarding
method in real server to allow the connections to provide
correct forwarding method to the backup server. Not sure if
this breaks tools that expect to see 'Local' real server type.
If needed, this can be supported with new flag IP_VS_DEST_F_LOCAL.
Now it should be possible connections in backup that lost
their fwmark information during sync to be forwarded properly
to their daddr, even if it is local address in the backup server.
By this way backup could be used as real server for DR or TUN,
for NAT there are some restrictions because tuple collisions
in conntracks can create problems for the traffic.

- Call ip_vs_dst_reset when destination is updated in case
some real server IP type is changed between local and remote.

[ horms@verge.net.au: removed trailing whitespace ]
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>


# 4256f1aa 17-Oct-2010 Julian Anastasov <ja@ssi.bg>

ipvs: fix CHECKSUM_PARTIAL for TUN method

The recent change in IP_VS_XMIT_TUNNEL to set
CHECKSUM_NONE is not correct. After adding IPIP header
skb->csum becomes invalid but the CHECKSUM_PARTIAL
case must be supported. So, use skb_forward_csum() which is
most suitable for us to allow local clients to send IPIP
to remote real server.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>


# cf356d69 17-Oct-2010 Julian Anastasov <ja@ssi.bg>

ipvs: switch to notrack mode

Change skb->ipvs_property semantic. This is preparation
to support ip_vs_out processing in LOCAL_OUT. ipvs_property=1
will be used to avoid expensive lookups for traffic sent by
transmitters. Now when conntrack support is not used we call
ip_vs_notrack method to avoid problems in OUTPUT and
POST_ROUTING hooks instead of exiting POST_ROUTING as before.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>


# 714f095f 19-Oct-2010 Hans Schillstrom <hans.schillstrom@ericsson.com>

ipvs: IPv6 tunnel mode

IPv6 encapsulation uses a bad source address for the tunnel.
i.e. VIP will be used as local-addr and encap. dst addr.
Decapsulation will not accept this.

Example
LVS (eth1 2003::2:0:1/96, VIP 2003::2:0:100)
(eth0 2003::1:0:1/96)
RS (ethX 2003::1:0:5/96)

tcpdump
2003::2:0:100 > 2003::1:0:5: IP6 (hlim 63, next-header TCP (6) payload length: 40) 2003::3:0:10.50991 > 2003::2:0:100.http: Flags [S], cksum 0x7312 (correct), seq 3006460279, win 5760, options [mss 1440,sackOK,TS val 1904932 ecr 0,nop,wscale 3], length 0

In Linux IPv6 impl. you can't have a tunnel with an any cast address
receiving packets (I have not tried to interpret RFC 2473)
To have receive capabilities the tunnel must have:
- Local address set as multicast addr or an unicast addr
- Remote address set as an unicast addr.
- Loop back addres or Link local address are not allowed.

This causes us to setup a tunnel in the Real Server with the
LVS as the remote address, here you can't use the VIP address since it's
used inside the tunnel.

Solution
Use outgoing interface IPv6 address (match against the destination).
i.e. use ip6_route_output() to look up the route cache and
then use ipv6_dev_get_saddr(...) to set the source address of the
encapsulated packet.

Additionally, cache the results in new destination
fields: dst_cookie and dst_saddr and properly check the
returned dst from ip6_route_output. We now add xfrm_lookup
call only for the tunneling method where the source address
is a local one.

Signed-off-by:Hans Schillstrom <hans.schillstrom@ericsson.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>


# f4bc17cd 21-Sep-2010 Julian Anastasov <ja@ssi.bg>

ipvs: netfilter connection tracking changes

Add more code to IPVS to work with Netfilter connection
tracking and fix some problems.

- Allow IPVS to be compiled without connection tracking as in
2.6.35 and before. This can avoid keeping conntracks for all
IPVS connections because this costs memory. ip_vs_ftp still
depends on connection tracking and NAT as implemented for 2.6.36.

- Add sysctl var "conntrack" to enable connection tracking for
all IPVS connections. For loaded IPVS directors it needs
tuning of nf_conntrack_max limit.

- Add IP_VS_CONN_F_NFCT connection flag to request the connection
to use connection tracking. This allows user space to provide this
flag, for example, in dest->conn_flags. This can be useful to
request connection tracking per real server instead of forcing it
for all connections with the "conntrack" sysctl. This flag is
set currently only by ip_vs_ftp and of course by "conntrack" sysctl.

- Add ip_vs_nfct.c file to hold all connection tracking code,
by this way main code should not depend of netfilter conntrack
support.

- Return back the ip_vs_post_routing handler as in 2.6.35 and use
skb->ipvs_property=1 to allow IPVS to work without connection
tracking

Connection tracking:

- most of the code is already in 2.6.36-rc

- alter conntrack reply tuple for LVS-NAT connections when first packet
from client is forwarded and conntrack state is NEW or RELATED.
Additionally, alter reply for RELATED connections from real server,
again for packet in original direction.

- add IP_VS_XMIT_TUNNEL to confirm conntrack (without altering
reply) for LVS-TUN early because we want to call nf_reset. It is
needed because we add IPIP header and the original conntrack
should be preserved, not destroyed. The transmitted IPIP packets
can reuse same conntrack, so we do not set skb->ipvs_property.

- try to destroy conntrack when the IPVS connection is destroyed.
It is not fatal if conntrack disappears before that, it depends
on the used timers.

Fix problems from long time:

- add skb->ip_summed = CHECKSUM_NONE for the LVS-TUN transmitters

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Patrick McHardy <kaber@trash.net>


# 6523ce15 05-Sep-2010 Julian Anastasov <ja@ssi.bg>

ipvs: fix active FTP

- Do not create expectation when forwarding the PORT
command to avoid blocking the connection. The problem is that
nf_conntrack_ftp.c:help() tries to create the same expectation later in
POST_ROUTING and drops the packet with "dropping packet" message after
failure in nf_ct_expect_related.

- Change ip_vs_update_conntrack to alter the conntrack
for related connections from real server. If we do not alter the reply in
this direction the next packet from client sent to vport 20 comes as NEW
connection. We alter it but may be some collision happens for both
conntracks and the second conntrack gets destroyed immediately. The
connection stucks too.

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


# 7b215ffc 22-Jul-2010 Hannes Eder <heder@google.com>

IPVS: make friends with nf_conntrack

Update the nf_conntrack tuple in reply direction, as we will see
traffic from the real server (RIP) to the client (CIP). Once this is
done we can use netfilters SNAT in POSTROUTING, especially with
xt_ipvs, to do source NAT, e.g.:

% iptables -t nat -A POSTROUTING -m ipvs --vaddr 192.168.100.30/32 --vport 80 \
-j SNAT --to-source 192.168.10.10

[ minor fixes by Simon Horman <horms@verge.net.au> ]
Signed-off-by: Hannes Eder <heder@google.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Patrick McHardy <kaber@trash.net>


# d8d1f30b 11-Jun-2010 Changli Gao <xiaosuo@gmail.com>

net-next: remove useless union keyword

remove useless union keyword in rtable, rt6_info and dn_route.

Since there is only one member in a union, the union keyword isn't useful.

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


# 5a0e3ad6 24-Mar-2010 Tejun Heo <tj@kernel.org>

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>


# 7911b5c7 22-Mar-2010 Jan Engelhardt <jengelh@medozas.de>

netfilter: ipvs: use NFPROTO values for NF_HOOK invocation

Semantic patch:
// <smpl>
@@
@@
IP_VS_XMIT(
-PF_INET6,
+NFPROTO_IPV6,
...)

@@
@@
IP_VS_XMIT(
-PF_INET,
+NFPROTO_IPV4,
...)
// </smpl>

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>


# 3ffe533c 18-Feb-2010 Alexey Dobriyan <adobriyan@gmail.com>

ipv6: drop unused "dev" arg of icmpv6_send()

Dunno, what was the idea, it wasn't used for a long time.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>


# 1e3e238e 02-Aug-2009 Hannes Eder <heder@google.com>

IPVS: use pr_err and friends instead of IP_VS_ERR and friends

Since pr_err and friends are used instead of printk there is no point
in keeping IP_VS_ERR and friends. Furthermore make use of '__func__'
instead of hard coded function names.

Signed-off-by: Hannes Eder <heder@google.com>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>


# 9aada7ac 30-Jul-2009 Hannes Eder <heder@google.com>

IPVS: use pr_fmt

While being at it cleanup whitespace.

Signed-off-by: Hannes Eder <heder@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>


# adf30907 01-Jun-2009 Eric Dumazet <eric.dumazet@gmail.com>

net: skb->dst accessors

Define three accessors to get/set dst attached to a skb

struct dst_entry *skb_dst(const struct sk_buff *skb)

void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst)

void skb_dst_drop(struct sk_buff *skb)
This one should replace occurrences of :
dst_release(skb->dst)
skb->dst = NULL;

Delete skb->dst field

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


# b7b45f47 10-Nov-2008 Harvey Harrison <harvey.harrison@gmail.com>

netfilter: payload_len is be16, add size of struct rather than size of pointer

payload_len is a be16 value, not cpu_endian, also the size of a ponter
to a struct ipv6hdr was being added, not the size of the struct itself.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>


# 14d5e834 31-Oct-2008 Harvey Harrison <harvey.harrison@gmail.com>

net: replace NIPQUAD() in net/netfilter/

Using NIPQUAD() with NIPQUAD_FMT, %d.%d.%d.%d or %u.%u.%u.%u
can be replaced with %pI4

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>


# 5b095d989 29-Oct-2008 Harvey Harrison <harvey.harrison@gmail.com>

net: replace %p6 with %pI6

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>


# 38ff4fa4 28-Oct-2008 Harvey Harrison <harvey.harrison@gmail.com>

netfilter: replace uses of NIP6_FMT with %p6

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>


# cb7f6a7b 18-Sep-2008 Julius Volz <juliusv@google.com>

IPVS: Move IPVS to net/netfilter/ipvs

Since IPVS now has partial IPv6 support, this patch moves IPVS from
net/ipv4/ipvs to net/netfilter/ipvs. It's a result of:

$ git mv net/ipv4/ipvs net/netfilter

and adapting the relevant Kconfigs/Makefiles to the new path.

Signed-off-by: Julius Volz <juliusv@google.com>
Signed-off-by: Simon Horman <horms@verge.net.au>