TCP_SACK_SEEN     249 net/ipv4/syncookies.c 	tcp_opt->sack_ok = (options & TS_OPT_SACK) ? TCP_SACK_SEEN : 0;
TCP_SACK_SEEN    2770 net/ipv4/tcp.c 			tp->rx_opt.sack_ok |= TCP_SACK_SEEN;
TCP_SACK_SEEN    3908 net/ipv4/tcp_input.c 					opt_rx->sack_ok = TCP_SACK_SEEN;