• Martin KaFai Lau's avatar
    tcp: Handle eor bit when fragmenting a skb · a166140e
    Martin KaFai Lau authored
    When fragmenting a skb, the next_skb should carry
    the eor from prev_skb.  The eor of prev_skb should
    also be reset.
    
    Packetdrill script for testing:
    ~~~~~~
    +0 `sysctl -q -w net.ipv4.tcp_min_tso_segs=10`
    +0 `sysctl -q -w net.ipv4.tcp_no_metrics_save=1`
    +0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
    +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
    +0 bind(3, ..., ...) = 0
    +0 listen(3, 1) = 0
    
    0.100 < S 0:0(0) win 32792 <mss 1460,sackOK,nop,nop,nop,wscale 7>
    0.100 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 7>
    0.200 < . 1:1(0) ack 1 win 257
    0.200 accept(3, ..., ...) = 4
    +0 setsockopt(4, SOL_TCP, TCP_NODELAY, [1], 4) = 0
    
    0.200 sendto(4, ..., 15330, MSG_EOR, ..., ...) = 15330
    0.200 sendto(4, ..., 730, 0, ..., ...) = 730
    
    0.200 > .  1:7301(7300) ack 1
    0.200 > . 7301:14601(7300) ack 1
    
    0.300 < . 1:1(0) ack 14601 win 257
    0.300 > P. 14601:15331(730) ack 1
    0.300 > P. 15331:16061(730) ack 1
    
    0.400 < . 1:1(0) ack 16061 win 257
    0.400 close(4) = 0
    0.400 > F. 16061:16061(0) ack 1
    0.400 < F. 1:1(0) ack 16062 win 257
    0.400 > . 16062:16062(0) ack 2
    Signed-off-by: default avatarMartin KaFai Lau <kafai@fb.com>
    Cc: Eric Dumazet <edumazet@google.com>
    Cc: Neal Cardwell <ncardwell@google.com>
    Cc: Soheil Hassas Yeganeh <soheil@google.com>
    Cc: Willem de Bruijn <willemb@google.com>
    Cc: Yuchung Cheng <ycheng@google.com>
    Acked-by: default avatarEric Dumazet <edumazet@google.com>
    Acked-by: default avatarSoheil Hassas Yeganeh <soheil@google.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    a166140e
tcp_output.c 102 KB