// Test TCP_MAXSEG works on active/client TCP connections. // Create a socket. 0.000 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 // Set MSS to 1100. 0.010 setsockopt(3, SOL_TCP, TCP_MAXSEG, [1100], 4) = 0 // TODO(ncardwell): the following is silly; should we fix it? 0.020 getsockopt(3, SOL_TCP, TCP_MAXSEG, [536], [4]) = 0 0.100...0.200 connect(3, ..., ...) = 0 // Establish a connection with an outgoing advertised MSS of 1100. 0.100 > S 0:0(0) 0.200 < S. 0:0(0) ack 1 win 32792 0.200 > . 1:1(0) ack 1 0.300 getsockopt(3, SOL_TCP, TCP_MAXSEG, [1100], [4]) = 0 0.400 %{ assert tcpi_advmss == 1100; assert tcpi_snd_mss == 1100 }% // IW10 MSS should yield outgoing TSO packet with 10*1100 == 11000 bytes: 0.500 write(3, ..., 12000) = 12000 0.500 > . 1:11001(11000) ack 1