• Jon Maxwell's avatar
    tcp: Add mark for TIMEWAIT sockets · 00483690
    Jon Maxwell authored
    This version has some suggestions by Eric Dumazet:
    
    - Use a local variable for the mark in IPv6 instead of ctl_sk to avoid SMP
    races.
    - Use the more elegant "IP4_REPLY_MARK(net, skb->mark) ?: sk->sk_mark"
    statement.
    - Factorize code as sk_fullsock() check is not necessary.
    
    Aidan McGurn from Openwave Mobility systems reported the following bug:
    
    "Marked routing is broken on customer deployment. Its effects are large
    increase in Uplink retransmissions caused by the client never receiving
    the final ACK to their FINACK - this ACK misses the mark and routes out
    of the incorrect route."
    
    Currently marks are added to sk_buffs for replies when the "fwmark_reflect"
    sysctl is enabled. But not for TW sockets that had sk->sk_mark set via
    setsockopt(SO_MARK..).
    
    Fix this in IPv4/v6 by adding tw->tw_mark for TIME_WAIT sockets. Copy the the
    original sk->sk_mark in __inet_twsk_hashdance() to the new tw->tw_mark location.
    Then progate this so that the skb gets sent with the correct mark. Do the same
    for resets. Give the "fwmark_reflect" sysctl precedence over sk->sk_mark so that
    netfilter rules are still honored.
    Signed-off-by: default avatarJon Maxwell <jmaxwell37@gmail.com>
    Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    00483690
ip_output.c 39.3 KB