From 069d2955aa39b11764025031235ec3d7d215ce84 Mon Sep 17 00:00:00 2001 From: Neal Cardwell Date: Sun, 22 Apr 2012 09:45:47 +0000 Subject: [PATCH] tcp: fix TCP_MAXSEG for established IPv6 passive sockets [ Upstream commit d135c522f1234f62e81be29cebdf59e9955139ad ] Commit f5fff5d forgot to fix TCP_MAXSEG behavior IPv6 sockets, so IPv6 TCP server sockets that used TCP_MAXSEG would find that the advmss of child sockets would be incorrect. This commit mirrors the advmss logic from tcp_v4_syn_recv_sock in tcp_v6_syn_recv_sock. Eventually this logic should probably be shared between IPv4 and IPv6, but this at least fixes this issue. Signed-off-by: Neal Cardwell Acked-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv6/tcp_ipv6.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 3edd05ae4388..a89ca8df38b9 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -1493,6 +1493,10 @@ static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb, tcp_mtup_init(newsk); tcp_sync_mss(newsk, dst_mtu(dst)); newtp->advmss = dst_metric_advmss(dst); + if (tcp_sk(sk)->rx_opt.user_mss && + tcp_sk(sk)->rx_opt.user_mss < newtp->advmss) + newtp->advmss = tcp_sk(sk)->rx_opt.user_mss; + tcp_initialize_rcv_mss(newsk); if (tcp_rsk(req)->snt_synack) tcp_valid_rtt_meas(newsk, -- 2.39.5