user/sven/linux.git/include/net/ip.h, branch v4.4.148

ipv4: lock mtu in fnhe when received PMTU < net.ipv4.route.min_pmtu

2018-05-30T05:49:04Z

[ Upstream commit d52e5a7e7ca49457dd31fc8b42fb7c0d58a31221 ] Prior to the rework of PMTU information storage in commit 2c8cec5c10bc ("ipv4: Cache learned PMTU information in inetpeer."), when a PMTU event advertising a PMTU smaller than net.ipv4.route.min_pmtu was received, we would disable setting the DF flag on packets by locking the MTU metric, and set the PMTU to net.ipv4.route.min_pmtu. Since then, we don't disable DF, and set PMTU to net.ipv4.route.min_pmtu, so the intermediate router that has this link with a small MTU will have to drop the packets. This patch reestablishes pre-2.6.39 behavior by splitting rtable->rt_pmtu into a bitfield with rt_mtu_locked and rt_pmtu. rt_mtu_locked indicates that we shouldn't set the DF bit on that path, and is checked in ip_dont_fragment(). One possible workaround is to set net.ipv4.route.min_pmtu to a value low enough to accommodate the lowest MTU encountered. Fixes: 2c8cec5c10bc ("ipv4: Cache learned PMTU information in inetpeer.") Signed-off-by: Sabrina Dubroca Reviewed-by: Stefano Brivio Signed-off-by: David S. Miller Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

ipv4: igmp: guard against silly MTU values

2018-01-02T19:33:24Z

[ Upstream commit b5476022bbada3764609368f03329ca287528dc8 ] IPv4 stack reacts to changes to small MTU, by disabling itself under RTNL. But there is a window where threads not using RTNL can see a wrong device mtu. This can lead to surprises, in igmp code where it is assumed the mtu is suitable. Fix this by reading device mtu once and checking IPv4 minimal MTU. This patch adds missing IPV4_MIN_MTU define, to not abuse ETH_MIN_MTU anymore. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ipv4: better IP_MAX_MTU enforcement

2017-08-30T08:19:19Z

[ Upstream commit c780a049f9bf442314335372c9abc4548bfe3e44 ] While working on yet another syzkaller report, I found that our IP_MAX_MTU enforcements were not properly done. gcc seems to reload dev->mtu for min(dev->mtu, IP_MAX_MTU), and final result can be bigger than IP_MAX_MTU :/ This is a problem because device mtu can be changed on other cpus or threads. While this patch does not fix the issue I am working on, it is probably worth addressing it. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

udp: fix IP_CHECKSUM handling

2016-11-15T06:46:39Z

[ Upstream commit 10df8e6152c6c400a563a673e9956320bfce1871 ] First bug was added in commit ad6f939ab193 ("ip: Add offset parameter to ip_cmsg_recv") : Tom missed that ipv4 udp messages could be received on AF_INET6 socket. ip_cmsg_recv(msg, skb) should have been replaced by ip_cmsg_recv_offset(msg, skb, sizeof(struct udphdr)); Then commit e6afc8ace6dd ("udp: remove headers from UDP packets before queueing") forgot to adjust the offsets now UDP headers are pulled before skb are put in receive queue. Fixes: ad6f939ab193 ("ip: Add offset parameter to ip_cmsg_recv") Fixes: e6afc8ace6dd ("udp: remove headers from UDP packets before queueing") Signed-off-by: Eric Dumazet Cc: Sam Kumar Cc: Willem de Bruijn Tested-by: Willem de Bruijn Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ipv4: Pass struct net into ip_defrag and ip_check_defrag

2015-10-13T02:44:16Z

The function ip_defrag is called on both the input and the output paths of the networking stack. In particular conntrack when it is tracking outbound packets from the local machine calls ip_defrag. So add a struct net parameter and stop making ip_defrag guess which network namespace it needs to defragment packets in. Signed-off-by: "Eric W. Biederman" Acked-by: Pablo Neira Ayuso Signed-off-by: David S. Miller

dst: Pass net into dst->output

2015-10-08T11:27:03Z

The network namespace is already passed into dst_output pass it into dst->output lwt->output and friends. Signed-off-by: "Eric W. Biederman" Signed-off-by: David S. Miller

ipv4, ipv6: Pass net into ip_local_out and ip6_local_out

2015-10-08T11:27:02Z

Signed-off-by: "Eric W. Biederman" Signed-off-by: David S. Miller

ipv4, ipv6: Pass net into __ip_local_out and __ip6_local_out

2015-10-08T11:27:02Z

Signed-off-by: "Eric W. Biederman" Signed-off-by: David S. Miller

ipv4: Merge ip_local_out and ip_local_out_sk

2015-10-08T11:26:57Z

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" Signed-off-by: David S. Miller

ipv4: Merge __ip_local_out and __ip_local_out_sk

2015-10-08T11:26:57Z

Signed-off-by: "Eric W. Biederman" Signed-off-by: David S. Miller