Extern or forward variable declaration at include/net/tcp.h, line 271 References: include/net/tcp.h, line 271 net/ipv4/sysctl_net_ipv4.c, line 558 net/ipv4/sysctl_net_ipv4.c, line 559 net/ipv4/tcp.c, line 289 net/ipv4/tcp.c, line 291 net/ipv4/tcp.c, line 426 net/ipv4/tcp.c, line 3658 net/ipv4/tcp.c, line 3659 net/ipv4/tcp.c, line 3660 net/ipv4/tcp_input.c, line 313 net/ipv4/tcp_input.c, line 373 net/ipv4/tcp_input.c, line 420 net/ipv4/tcp_input.c, line 425 net/ipv4/tcp_input.c, line 562 net/ipv4/tcp_ipv4.c, line 2875 net/ipv4/tcp_output.c, line 229 net/ipv6/tcp_ipv6.c, line 1968