// Verify behavior for the sequence: // shutdown(SHUT_RD), receive, send, shutdown(SHUT_WR), close(). // Initialize a server socket. 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 < S 0:0(0) win 32792 +0 > S. 0:0(0) ack 1 +0 < . 1:1(0) ack 1 win 257 +0 accept(3, ..., ...) = 4 +.010 shutdown(4, SHUT_RD) = 0 +0 read(4, ..., 1000) = 0 // You would think that after SHUT_RD we would respond to incoming // data with a RST and not queue the data for reading, but we actually // ACK the data, enqueue it for reading, and can read() the data. // AFAICT in 2003 Andi Kleen seems to have decided that this case is too // obscure to slow down the fast path for receiving and reading data: // http://marc.info/?l=linux-netdev&m=105774722214242&w=2 // So.... // Verify that receiving and reading still works. +0 < . 1:1001(1000) ack 1 win 257 +0 > . 1:1(0) ack 1001 +0 read(4, ..., 1000) = 1000 // Verify that writing and sending still works. +.010 write(4, ..., 1000) = 1000 +0 > P. 1:1001(1000) ack 1001 +0 < . 1001:1001(0) ack 1001 win 257 +.010 shutdown(4, SHUT_WR) = 0 +0 > F. 1001:1001(0) ack 1001 +0 < . 1001:1001(0) ack 1002 win 257 +0 write(4, ..., 1000) = -1 EPIPE (Broken pipe) +.010 close(4) = 0 +.010 < F. 1001:1001(0) ack 1002 win 257 +0 > . 1002:1002(0) ack 1002