tmp_suning_uos_patched/net/ipv4
Bob Arendt 7998156344 ipv4: force_igmp_version ignored when a IGMPv3 query received
After all these years, it turns out that the
    /proc/sys/net/ipv4/conf/*/force_igmp_version
parameter isn't fully implemented.

*Symptom*:
When set force_igmp_version to a value of 2, the kernel should only perform
multicast IGMPv2 operations (IETF rfc2236).  An host-initiated Join message
will be sent as a IGMPv2 Join message.  But if a IGMPv3 query message is
received, the host responds with a IGMPv3 join message.  Per rfc3376 and
rfc2236, a IGMPv2 host should treat a IGMPv3 query as a IGMPv2 query and
respond with an IGMPv2 Join message.

*Consequences*:
This is an issue when a IGMPv3 capable switch is the querier and will only
issue IGMPv3 queries (which double as IGMPv2 querys) and there's an
intermediate switch that is only IGMPv2 capable.  The intermediate switch
processes the initial v2 Join, but fails to recognize the IGMPv3 Join responses
to the Query, resulting in a dropped connection when the intermediate v2-only
switch times it out.

*Identifying issue in the kernel source*:
The issue is in this section of code (in net/ipv4/igmp.c), which is called when
an IGMP query is received  (from mainline 2.6.36-rc3 gitweb):
 ...
A IGMPv3 query has a length >= 12 and no sources.  This routine will exit after
line 880, setting the general query timer (random timeout between 0 and query
response time).  This calls igmp_gq_timer_expire():
...
.. which only sends a v3 response.  So if a v3 query is received, the kernel
always sends a v3 response.

IGMP queries happen once every 60 sec (per vlan), so the traffic is low.  A
IGMPv3 query *is* a strict superset of a IGMPv2 query, so this patch properly
short circuit's the v3 behaviour.

One issue is that this does not address force_igmp_version=1.  Then again, I've
never seen any IGMPv1 multicast equipment in the wild.  However there is a lot
of v2-only equipment. If it's necessary to support the IGMPv1 case as well:

837         if (len == 8 || IGMP_V2_SEEN(in_dev) || IGMP_V1_SEEN(in_dev)) {

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-13 12:56:51 -07:00
..
netfilter netfilter: fix CONFIG_COMPAT support 2010-08-23 14:41:22 -07:00
af_inet.c inet, inet6: make tcp_sendmsg() and tcp_sendpage() through inet_sendmsg() and inet_sendpage() 2010-07-12 20:21:46 -07:00
ah4.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
arp.c net/ipv4: EXPORT_SYMBOL cleanups 2010-07-12 12:57:54 -07:00
cipso_ipv4.c net: Remove unnecessary returns from void function()s 2010-05-17 23:23:14 -07:00
datagram.c udp: add rehash on connect() 2010-09-08 21:45:01 -07:00
devinet.c arp_notify: allow drivers to explicitly request a notification event. 2010-05-31 00:27:44 -07:00
esp4.c xfrm: SA lookups signature with mark 2010-02-22 16:20:22 -08:00
fib_frontend.c ipv4: Fix reverse path filtering with multipath routing. 2010-09-07 13:57:24 -07:00
fib_hash.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
fib_lookup.h
fib_rules.c net: rtnetlink: decouple rtnetlink address families from real address families 2010-04-26 16:13:54 +02:00
fib_semantics.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
fib_trie.c ipv4: Suppress lockdep-RCU false positive in FIB trie (3) 2010-09-08 14:14:20 -07:00
icmp.c net/ipv4: EXPORT_SYMBOL cleanups 2010-07-12 12:57:54 -07:00
igmp.c ipv4: force_igmp_version ignored when a IGMPv3 query received 2010-09-13 12:56:51 -07:00
inet_connection_sock.c net/ipv4: EXPORT_SYMBOL cleanups 2010-07-12 12:57:54 -07:00
inet_diag.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
inet_fragment.c net/ipv4: EXPORT_SYMBOL cleanups 2010-07-12 12:57:54 -07:00
inet_hashtables.c net/ipv4: EXPORT_SYMBOL cleanups 2010-07-12 12:57:54 -07:00
inet_lro.c net/ipv4: Move && and || to end of previous line 2009-11-23 10:41:23 -08:00
inet_timewait_sock.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
inetpeer.c inetpeer: restore small inet_peer structures 2010-06-16 11:55:39 -07:00
ip_forward.c net-next: remove useless union keyword 2010-06-10 23:31:35 -07:00
ip_fragment.c net/ipv4: EXPORT_SYMBOL cleanups 2010-07-12 12:57:54 -07:00
ip_gre.c gre: propagate ipv6 transport class 2010-07-08 21:35:58 -07:00
ip_input.c net: use this_cpu_ptr() 2010-06-28 23:24:29 -07:00
ip_options.c net: Remove unnecessary returns from void function()s 2010-05-17 23:23:14 -07:00
ip_output.c ip_fragment: fix subtracting PPPOE_SES_HLEN from mtu twice 2010-08-02 17:25:07 -07:00
ip_sockglue.c net - IP_NODEFRAG option for IPv4 socket 2010-06-23 13:16:38 -07:00
ipcomp.c xfrm: SA lookups signature with mark 2010-02-22 16:20:22 -08:00
ipconfig.c ipconfig: send host-name in DHCP requests 2010-06-02 07:05:03 -07:00
ipip.c net-next: remove useless union keyword 2010-06-10 23:31:35 -07:00
ipmr.c Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-07-20 18:25:24 -07:00
Kconfig ipv4: minor fix about RPF in help of Kconfig 2010-09-01 14:29:36 -07:00
Makefile
netfilter.c Merge branch 'master' of /repos/git/net-next-2.6 2010-06-15 17:31:06 +02:00
proc.c snmp: 64bit ipstats_mib for all arches 2010-06-30 13:31:19 -07:00
protocol.c net/ipv4: EXPORT_SYMBOL cleanups 2010-07-12 12:57:54 -07:00
raw.c net-next: remove useless union keyword 2010-06-10 23:31:35 -07:00
route.c net: blackhole route should always be recalculated 2010-09-08 14:35:43 -07:00
syncookies.c syncookies: add support for ECN 2010-06-26 22:00:03 -07:00
sysctl_net_ipv4.c net: reserve ports for applications using fixed port numbers 2010-05-15 23:28:40 -07:00
tcp_bic.c
tcp_cong.c net/ipv4: Eliminate kstrdup memory leak 2010-08-27 19:31:56 -07:00
tcp_cubic.c
tcp_diag.c tcp: diag: Dont report negative values for rx queue 2009-12-03 16:06:13 -08:00
tcp_highspeed.c
tcp_htcp.c net/ipv4: Move && and || to end of previous line 2009-11-23 10:41:23 -08:00
tcp_hybla.c TCP: tcp_hybla: Fix integer overflow in slow start increment 2010-06-02 07:15:48 -07:00
tcp_illinois.c
tcp_input.c tcp: no md5sig option size check bug 2010-08-07 20:24:28 -07:00
tcp_ipv4.c inet, inet6: make tcp_sendmsg() and tcp_sendpage() through inet_sendmsg() and inet_sendpage() 2010-07-12 20:21:46 -07:00
tcp_lp.c net/ipv4: Move && and || to end of previous line 2009-11-23 10:41:23 -08:00
tcp_minisocks.c net/ipv4: EXPORT_SYMBOL cleanups 2010-07-12 12:57:54 -07:00
tcp_output.c Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-07-20 18:25:24 -07:00
tcp_probe.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
tcp_scalable.c
tcp_timer.c tcp: Combat per-cpu skew in orphan tests. 2010-08-25 02:27:49 -07:00
tcp_vegas.c
tcp_vegas.h
tcp_veno.c net/ipv4: Move && and || to end of previous line 2009-11-23 10:41:23 -08:00
tcp_westwood.c
tcp_yeah.c net/ipv4: Move && and || to end of previous line 2009-11-23 10:41:23 -08:00
tcp.c tcp: select(writefds) don't hang up when a peer close connection 2010-08-25 23:02:48 -07:00
tunnel4.c net/ipv4: EXPORT_SYMBOL cleanups 2010-07-12 12:57:54 -07:00
udp_impl.h net: Make setsockopt() optlen be unsigned. 2009-09-30 16:12:20 -07:00
udp.c udp: add rehash on connect() 2010-09-08 21:45:01 -07:00
udplite.c net/ipv4: EXPORT_SYMBOL cleanups 2010-07-12 12:57:54 -07:00
xfrm4_input.c net/ipv4: EXPORT_SYMBOL cleanups 2010-07-12 12:57:54 -07:00
xfrm4_mode_beet.c
xfrm4_mode_transport.c
xfrm4_mode_tunnel.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
xfrm4_output.c netfilter: ipv4: use NFPROTO values for NF_HOOK invocation 2010-03-25 16:00:30 +01:00
xfrm4_policy.c Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-07-07 15:59:38 -07:00
xfrm4_state.c
xfrm4_tunnel.c