From d4289fcc9b16b89619ee1c54f829e05e56de8b9a Mon Sep 17 00:00:00 2001 From: Peter Oskolkov Date: Tue, 22 Jan 2019 10:02:51 -0800 Subject: net: IP6 defrag: use rbtrees for IPv6 defrag Currently, IPv6 defragmentation code drops non-last fragments that are smaller than 1280 bytes: see commit 0ed4229b08c1 ("ipv6: defrag: drop non-last frags smaller than min mtu") This behavior is not specified in IPv6 RFCs and appears to break compatibility with some IPv6 implemenations, as reported here: https://www.spinics.net/lists/netdev/msg543846.html This patch re-uses common IP defragmentation queueing and reassembly code in IPv6, removing the 1280 byte restriction. Signed-off-by: Peter Oskolkov Reported-by: Tom Herbert Cc: Eric Dumazet Cc: Florian Westphal Signed-off-by: David S. Miller --- include/net/ipv6_frag.h | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'include/net/ipv6_frag.h') diff --git a/include/net/ipv6_frag.h b/include/net/ipv6_frag.h index 6ced1e6899b6..28aa9b30aece 100644 --- a/include/net/ipv6_frag.h +++ b/include/net/ipv6_frag.h @@ -82,8 +82,15 @@ ip6frag_expire_frag_queue(struct net *net, struct frag_queue *fq) __IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT); /* Don't send error if the first segment did not arrive. */ - head = fq->q.fragments; - if (!(fq->q.flags & INET_FRAG_FIRST_IN) || !head) + if (!(fq->q.flags & INET_FRAG_FIRST_IN)) + goto out; + + /* sk_buff::dev and sk_buff::rbnode are unionized. So we + * pull the head out of the tree in order to be able to + * deal with head->dev. + */ + head = inet_frag_pull_head(&fq->q); + if (!head) goto out; head->dev = dev; -- cgit v1.2.3