github.com/SagerNet/gvisor@v0.0.0-20210707092255-7731c139d75c/test/packetdrill/accept_ack_drop.pkt (about)

     1  // Test that the accept works if the final ACK is dropped and an ack with data
     2  // follows the dropped ack.
     3  
     4  0  socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
     5  +0 bind(3, ..., ...) = 0
     6  
     7  // Set backlog to 1 so that we can easily test.
     8  +0 listen(3, 1) = 0
     9  
    10  // Establish a connection without timestamps.
    11  +0.0 < S 0:0(0) win 32792 <mss 1460,sackOK,nop,nop,nop,wscale 7>
    12  +0.0 > S. 0:0(0) ack 1    <...>
    13  
    14  +0.0 < . 1:5(4) ack 1 win 257
    15  +0.0 > . 1:1(0) ack 5 <...>
    16  
    17  // This should cause connection to transition to connected state.
    18  +0.000 accept(3, ..., ...) = 4
    19  +0.000 fcntl(4, F_SETFL, O_RDWR|O_NONBLOCK) = 0
    20  
    21  // Now read the data and we should get 4 bytes.
    22  +0.000 read(4,..., 4) = 4
    23  +0.000 close(4) = 0
    24  
    25  +0.0 > F. 1:1(0) ack 5 <...>
    26  +0.0 < F. 5:5(0) ack 2 win 257
    27  +0.01 > . 2:2(0) ack 6 <...>