• Florian Westphal's avatar
    tcp: honour SO_BINDTODEVICE for TW_RST case too · 271c3b9b
    Florian Westphal authored
    Hannes points out that when we generate tcp reset for timewait sockets we
    pretend we found no socket and pass NULL sk to tcp_vX_send_reset().
    
    Make it cope with inet tw sockets and then provide tw sk.
    
    This makes RSTs appear on correct interface when SO_BINDTODEVICE is used.
    
    Packetdrill test case:
    // want default route to be used, we rely on BINDTODEVICE
    `ip route del 192.0.2.0/24 via 192.168.0.2 dev tun0`
    
    0.000 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
    // test case still works due to BINDTODEVICE
    0.001 setsockopt(3, SOL_SOCKET, SO_BINDTODEVICE, "tun0", 4) = 0
    0.100...0.200 connect(3, ..., ...) = 0
    
    0.100 > S 0:0(0) <mss 1460,sackOK,nop,nop>
    0.200 < S. 0:0(0) ack 1 win 32792 <mss 1460,sackOK,nop,nop>
    0.200 > . 1:1(0) ack 1
    
    0.210 close(3) = 0
    
    0.210 > F. 1:1(0) ack 1 win 29200
    0.300 < . 1:1(0) ack 2 win 46
    
    // more data while in FIN_WAIT2, expect RST
    1.300 < P. 1:1001(1000) ack 1 win 46
    
    // fails without this change -- default route is used
    1.301 > R 1:1(0) win 0
    Reported-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
    Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
    Acked-by: default avatarEric Dumazet <edumazet@google.com>
    Acked-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    271c3b9b
tcp_minisocks.c 26 KB