ipvs: add missing module descriptions

W=1 builds warn on missing MODULE_DESCRIPTION, add them.

Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

treewide: Add SPDX license identifier for more missed files

Add SPDX license identifiers to all files which:

- Have no license information of any form

- Have MODULE_LICENCE("GPL*") inside which was used in the initial
scan/conversion to ignore the file

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ipvs: handle connections started by real-servers

When using LVS-NAT and SIP persistence-egine over UDP, the following
limitations are present with current implementation:

1) To actually have load-balancing based on Call-ID header, you need to
use one-packet-scheduling mode. But with one-packet-scheduling the
connection is deleted just after packet is forwarded, so SIP responses
coming from real-servers do not match any connection and SNAT is
not applied.

2) If you do not use "-o" option, IPVS behaves as normal UDP load
balancer, so different SIP calls (each one identified by a different
Call-ID) coming from the same ip-address/port go to the same
real-server. So basically you don’t have load-balancing based on
Call-ID as intended.

3) Call-ID is not learned when a new SIP call is started by a real-server
(inside-to-outside direction), but only in the outside-to-inside
direction. This would be a general problem for all SIP servers acting
as Back2BackUserAgent.

This patch aims to solve problems 1) and 3) while keeping OPS mode
mandatory for SIP-UDP, so that 2) is not a problem anymore.

The basic mechanism implemented is to make packets, that do not match any
existent connection but come from real-servers, create new connections
instead of let them pass without any effect.
When such packets pass through ip_vs_out(), if their source ip address and
source port match a configured real-server, a new connection is
automatically created in the same way as it would have happened if the
packet had come from outside-to-inside direction. A new connection template
is created too if the virtual-service is persistent and there is no
matching connection template found. The new connection automatically
created, if the service had "-o" option, is an OPS connection that lasts
only the time to forward the packet, just like it happens on the
ingress side.

The main part of this mechanism is implemented inside a persistent-engine
specific callback (at the moment only SIP persistent engine exists) and
is triggered only for UDP packets, since connection oriented protocols, by
using different set of ports (typically ephemeral ports) to open new
outgoing connections, should not need this feature.

The following requisites are needed for automatic connection creation; if
any is missing the packet simply goes the same way as before.
a) virtual-service is not fwmark based (this is because fwmark services
do not store address and port of the virtual-service, required to
build the connection data).
b) virtual-service and real-servers must not have been configured with
omitted port (this is again to have all data to create the connection).

Signed-off-by: Marco Angaroni <marcoangaroni@gmail.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

ipvs: correct initial offset of Call-ID header search in SIP persistence engine

The IPVS SIP persistence engine is not able to parse the SIP header
"Call-ID" when such header is inserted in the first positions of
the SIP message.

When IPVS is configured with "--pe sip" option, like for example:
ipvsadm -A -u 1.2.3.4:5060 -s rr --pe sip -p 120 -o
some particular messages (see below for details) do not create entries
in the connection template table, which can be listed with:
ipvsadm -Lcn --persistent-conn

Problematic SIP messages are SIP responses having "Call-ID" header
positioned just after message first line:
SIP/2.0 200 OK
[Call-ID header here]
[rest of the headers]

When "Call-ID" header is positioned down (after a few other headers)
it is correctly recognized.

This is due to the data offset used in get_callid function call inside
ip_vs_pe_sip.c file: since dptr already points to the start of the
SIP message, the value of dataoff should be initially 0.
Otherwise the header is searched starting from some bytes after the
first character of the SIP message.

Fixes: 758ff0338722 ("IPVS: sip persistence engine")
Signed-off-by: Marco Angaroni <marcoangaroni@gmail.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

ipvs: handle ip_vs_fill_iph_skb_off failure

ip_vs_fill_iph_skb_off() may not find an IP header, and gcc has
determined that ip_vs_sip_fill_param() then incorrectly accesses
the protocol fields:

net/netfilter/ipvs/ip_vs_pe_sip.c: In function 'ip_vs_sip_fill_param':
net/netfilter/ipvs/ip_vs_pe_sip.c:76:5: error: 'iph.protocol' may be used uninitialized in this function [-Werror=maybe-uninitialized]
if (iph.protocol != IPPROTO_UDP)
^
net/netfilter/ipvs/ip_vs_pe_sip.c:81:10: error: 'iph.len' may be used uninitialized in this function [-Werror=maybe-uninitialized]
dataoff = iph.len + sizeof(struct udphdr);
^

This adds a check for the ip_vs_fill_iph_skb_off() return code
before looking at the ip header data returned from it.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: b0e010c527de ("ipvs: replace ip_vs_fill_ip4hdr with ip_vs_fill_iph_skb_off")
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

ipvs: Add hdr_flags to iphdr

These flags contain information like whether or not the addresses are
inverted or from icmp. The first will allow us to drop an inverse param
all over the place, and the second will later be useful in scheduling icmp.

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

netfilter: push reasm skb through instead of original frag skbs

Pushing original fragments through causes several problems. For example
for matching, frags may not be matched correctly. Take following
example:

<example>
On HOSTA do:
ip6tables -I INPUT -p icmpv6 -j DROP
ip6tables -I INPUT -p icmpv6 -m icmp6 --icmpv6-type 128 -j ACCEPT

and on HOSTB you do:
ping6 HOSTA -s2000 (MTU is 1500)

Incoming echo requests will be filtered out on HOSTA. This issue does
not occur with smaller packets than MTU (where fragmentation does not happen)
</example>

As was discussed previously, the only correct solution seems to be to use
reassembled skb instead of separete frags. Doing this has positive side
effects in reducing sk_buff by one pointer (nfct_reasm) and also the reams
dances in ipvs and conntrack can be removed.

Future plan is to remove net/ipv6/netfilter/nf_conntrack_reasm.c
entirely and use code in net/ipv6/reassembly.c instead.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Marcelo Ricardo Leitner <mleitner@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipvs: ip_vs_sip_fill_param() BUG: bad check of return value

The reason for this patch is crash in kmemdup
caused by returning from get_callid with uniialized
matchoff and matchlen.

Removing Zero check of matchlen since it's done by ct_sip_get_header()

BUG: unable to handle kernel paging request at ffff880457b5763f
IP: [<ffffffff810df7fc>] kmemdup+0x2e/0x35
PGD 27f6067 PUD 0
Oops: 0000 [#1] PREEMPT SMP
Modules linked in: xt_state xt_helper nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_mangle xt_connmark xt_conntrack ip6_tables nf_conntrack_ftp ip_vs_ftp nf_nat xt_tcpudp iptable_mangle xt_mark ip_tables x_tables ip_vs_rr ip_vs_lblcr ip_vs_pe_sip ip_vs nf_conntrack_sip nf_conntrack bonding igb i2c_algo_bit i2c_core
CPU 5
Pid: 0, comm: swapper/5 Not tainted 3.9.0-rc5+ #5 /S1200KP
RIP: 0010:[<ffffffff810df7fc>] [<ffffffff810df7fc>] kmemdup+0x2e/0x35
RSP: 0018:ffff8803fea03648 EFLAGS: 00010282
RAX: ffff8803d61063e0 RBX: 0000000000000003 RCX: 0000000000000003
RDX: 0000000000000003 RSI: ffff880457b5763f RDI: ffff8803d61063e0
RBP: ffff8803fea03658 R08: 0000000000000008 R09: 0000000000000011
R10: 0000000000000011 R11: 00ffffffff81a8a3 R12: ffff880457b5763f
R13: ffff8803d67f786a R14: ffff8803fea03730 R15: ffffffffa0098e90
FS: 0000000000000000(0000) GS:ffff8803fea00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff880457b5763f CR3: 0000000001a0c000 CR4: 00000000001407e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process swapper/5 (pid: 0, threadinfo ffff8803ee18c000, task ffff8803ee18a480)
Stack:
ffff8803d822a080 000000000000001c ffff8803fea036c8 ffffffffa000937a
ffffffff81f0d8a0 000000038135fdd5 ffff880300000014 ffff880300110000
ffffffff150118ac ffff8803d7e8a000 ffff88031e0118ac 0000000000000000
Call Trace:
<IRQ>

[<ffffffffa000937a>] ip_vs_sip_fill_param+0x13a/0x187 [ip_vs_pe_sip]
[<ffffffffa007b209>] ip_vs_sched_persist+0x2c6/0x9c3 [ip_vs]
[<ffffffff8107dc53>] ? __lock_acquire+0x677/0x1697
[<ffffffff8100972e>] ? native_sched_clock+0x3c/0x7d
[<ffffffff8100972e>] ? native_sched_clock+0x3c/0x7d
[<ffffffff810649bc>] ? sched_clock_cpu+0x43/0xcf
[<ffffffffa007bb1e>] ip_vs_schedule+0x181/0x4ba [ip_vs]
...

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

ipvs: Use min3() in ip_vs_dbg_callid()

There are two motivations for this:

1. It improves readability to my eyes
2. Using nested min() calls results in a shadowed _min1 variable,
which is a bit untidy. Sparse complained about this.

I have also replaced (size_t)64 with a variable of type size_t and value 64.
This also improves readability to my eyes.

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

ipvs: convert locks used in persistence engines

Allow the readers to use RCU lock and for
PE module registrations use global mutex instead of
spinlock. All PE modules need to use synchronize_rcu
in their module exit handler.

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>

ipvs: SIP fragment handling

Use the nfct_reasm SKB if available.

Based on part of a patch from: Hans Schillstrom
I have left Hans'es comment in the patch (marked /HS)

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

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>

net: fix assignment of 0/1 to bool variables.

DaveM said:
Please, this kind of stuff rots forever and not using bool properly
drives me crazy.

Joe Perches <joe@perches.com> gave me the spatch script:

@@
bool b;
@@
-b = 0
+b = false
@@
bool b;
@@
-b = 1
+b = true

I merely installed coccinelle, read the documentation and took credit.

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

netfilter:ipvs: use kmemdup

The semantic patch that makes this output is available
in scripts/coccinelle/api/memdup.cocci.

More information about semantic patching is available at
http://coccinelle.lip6.fr/

Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com>
Signed-off-by: Simon Horman <horms@verge.net.au>

IPVS: skb defrag in L7 helpers

L7 helpers like sip needs skb defrag
since L7 data can be fragmented.

This patch requires "IPVS Break ports-2 into src_port and dst_port" patch

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

IPVS: ip_vs_dbg_callid() is only needed for debugging

ip_vs_dbg_callid() and IP_VS_DEBUG_CALLID() are only needed
it CONFIG_IP_VS_DEBUG is defined.

This resolves the following build warning when CONFIG_IP_VS_DEBUG is
not defined.

net/netfilter/ipvs/ip_vs_pe_sip.c:11: warning: 'ip_vs_dbg_callid' defined but not used

Reported-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Patrick McHardy <kaber@trash.net>

IPVS: sip persistence engine

Add the SIP callid as a key for persistence.

This allows multiple connections from the same IP address to be
differentiated on the basis of the callid.

When used in conjunction with the persistence mask, it allows connections
from different IP addresses to be aggregated on the basis of the callid.

It is envisaged that a persistence mask of 0.0.0.0 will be a useful
setting. That is, ignore the source IP address when checking for
persistence.

It is envisaged that this option will be used in conjunction with
one-packet scheduling.

This only works with UDP and cannot be made to work with TCP
within the current framework.

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