LINUX_MIB_TCPCHALLENGEACK 254 net/ipv4/proc.c SNMP_MIB_ITEM("TCPChallengeACK", LINUX_MIB_TCPCHALLENGEACK), LINUX_MIB_TCPCHALLENGEACK 3481 net/ipv4/tcp_input.c NET_INC_STATS(net, LINUX_MIB_TCPCHALLENGEACK);