kernel.git/net/ipv4/route.c, branch linux-3.6.y

ipv4: do not cache looped multicasts

2012-12-17T17:27:18Z

[ Upstream commit 636174219b52b5a8bc51bc23bbcba97cd30a65e3 ] Starting from 3.6 we cache output routes for multicasts only when using route to 224/4. For local receivers we can set RTCF_LOCAL flag depending on the membership but in such case we use maddr and saddr which are not caching keys as before. Additionally, we can not use same place to cache routes that differ in RTCF_LOCAL flag value. Fix it by caching only RTCF_MULTICAST entries without RTCF_LOCAL (send-only, no loopback). As a side effect, we avoid unneeded lookup for fnhe when not caching because multicasts are not redirected and they do not learn PMTU. Thanks to Maxime Bizon for showing the caching problems in __mkroute_output for 3.6 kernels: different RTCF_LOCAL flag in cache can lead to wrong ip_mc_output or ip_output call and the visible problem is that traffic can not reach local receivers via loopback. Reported-by: Maxime Bizon Tested-by: Maxime Bizon Signed-off-by: Julian Anastasov Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ipv4: Fix flushing of cached routing informations

2012-11-17T21:18:52Z

[ Upstream commit 13d82bf50dce632355fcccafa4fe44a9b5e706d8 ] Currently we can not flush cached pmtu/redirect informations via the ipv4_sysctl_rtcache_flush sysctl. We need to check the rt_genid of the old route and reset the nh exeption if the old route is expired when we bind a new route to a nh exeption. Signed-off-by: Steffen Klassert Acked-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ipv4: Add FLOWI_FLAG_KNOWN_NH

2012-10-28T17:56:17Z

[ Upstream commit c92b96553a80c1dbe2ebe128bbe37c8f98f148bf ] Add flag to request that output route should be returned with known rt_gateway, in case we want to use it as nexthop for neighbour resolving. The returned route can be cached as follows: - in NH exception: because the cached routes are not shared with other destinations - in FIB NH: when using gateway because all destinations for NH share same gateway As last option, to return rt_gateway!=0 we have to set DST_NOCACHE. Signed-off-by: Julian Anastasov Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ipv4: introduce rt_uses_gateway

2012-10-28T17:56:17Z

[ Upstream commit 155e8336c373d14d87a7f91e356d85ef4b93b8f9 ] Add new flag to remember when route is via gateway. We will use it to allow rt_gateway to contain address of directly connected host for the cases when DST_NOCACHE is used or when the NH exception caches per-destination route without DST_NOCACHE flag, i.e. when routes are not used for other destinations. By this way we force the neighbour resolving to work with the routed destination but we can use different address in the packet, feature needed for IPVS-DR where original packet for virtual IP is routed via route to real IP. Signed-off-by: Julian Anastasov Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ipv4: make sure nh_pcpu_rth_output is always allocated

2012-10-28T17:56:17Z

[ Upstream commit f8a17175c63fd3e8b573719f7538816f8c96abf4 ] Avoid checking nh_pcpu_rth_output in fast path, abort fib_info creation on alloc_percpu failure. Signed-off-by: Julian Anastasov Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ipv4: fix sending of redirects

2012-10-28T17:56:17Z

[ Upstream commit e81da0e113a1b7fc7449ae6213f65f89ccac6d06 ] After "Cache input routes in fib_info nexthops" (commit d2d68ba9fe) and "Elide fib_validate_source() completely when possible" (commit 7a9bc9b81a) we can not send ICMP redirects. It seems we should not cache the RTCF_DOREDIRECT flag in nh_rth_input because the same fib_info can be used for traffic that is not redirected, eg. from other input devices or from sources that are not in same subnet. As result, we have to disable the caching of RTCF_DOREDIRECT flag and to force source validation for the case when forwarding traffic to the input device. If traffic comes from directly connected source we allow redirection as it was done before both changes. Avoid setting RTCF_DOREDIRECT if IN_DEV_TX_REDIRECTS is disabled, this can avoid source address validation and to help caching the routes. After the change "Adjust semantics of rt->rt_gateway" (commit f8126f1d51) we should make sure our ICMP_REDIR_HOST messages contain daddr instead of 0.0.0.0 when target is directly connected. Signed-off-by: Julian Anastasov Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ipv4: Don't report stale pmtu values to userspace

2012-10-28T17:56:16Z

[ Upstream commit ee9a8f7ab2edf801b8b514c310455c94acc232f6 ] We report cached pmtu values even if they are already expired. Change this to not report these values after they are expired and fix a race in the expire time calculation, as suggested by Eric Dumazet. Signed-off-by: Steffen Klassert Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ipv4: Don't create nh exeption when the device mtu is smaller than the reported pmtu

2012-10-28T17:56:16Z

[ Upstream commit 7f92d334ba19a0d8e96f8f8f092219553367d921 ] When a local tool like tracepath tries to send packets bigger than the device mtu, we create a nh exeption and set the pmtu to device mtu. The device mtu does not expire, so check if the device mtu is smaller than the reported pmtu and don't crerate a nh exeption in that case. Signed-off-by: Steffen Klassert Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ipv4: Always invalidate or update the route on pmtu events

2012-10-28T17:56:16Z

[ Upstream commit d851c12b60471188e15e5c8405b289073e8dd025 ] Some protocols, like IPsec still cache routes. So we need to invalidate the old route on pmtu events to avoid the reuse of stale routes. We also need to update the mtu and expire time of the route if we already use a nh exception route, otherwise we ignore newly learned pmtu values after the first expiration. With this patch we always invalidate or update the route on pmtu events. Signed-off-by: Steffen Klassert Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

netns: move net->ipv4.rt_genid to net->rt_genid

2012-09-18T19:57:03Z

This commit prepares the use of rt_genid by both IPv4 and IPv6. Initialization is left in IPv4 part. Signed-off-by: Nicolas Dichtel Signed-off-by: David S. Miller