9  *		IPv4 specific functions
12  *		linux/ipv4/tcp.c
13  *		linux/ipv4/tcp_input.c
14  *		linux/ipv4/tcp_output.c
44  *	Alexey Kuznetsov		allow both IPv4 and IPv6 sockets to bind
111 	int reuse = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_tw_reuse);  in tcp_twsk_unique()
250 	tcp_death_row = &sock_net(sk)->ipv4.tcp_death_row;  in tcp_v4_connect()
487 	sk = __inet_lookup_established(net, net->ipv4.tcp_death_row.hashinfo,  in tcp_v4_err()
649 /* This routine computes an IPv4 TCP checksum. */
752 		sk1 = __inet_lookup_listener(net, net->ipv4.tcp_death_row.hashinfo,  in tcp_v4_send_reset()
1020 		tos = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos) ?  in tcp_v4_send_synack()
1042  *	IPv4 request_sock destructor.
1540 	if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos))  in tcp_v4_syn_recv_sock()
1738 	sk = __inet_lookup_established(net, net->ipv4.tcp_death_row.hashinfo,  in tcp_v4_early_demux()
1966 	sk = __inet_lookup_skb(net->ipv4.tcp_death_row.hashinfo,  in tcp_v4_rcv()
2150 							net->ipv4.tcp_death_row.hashinfo,  in tcp_v4_rcv()
2301 	struct inet_hashinfo *hinfo = seq_file_net(seq)->ipv4.tcp_death_row.hashinfo;  in listening_get_first()
2347 	hinfo = seq_file_net(seq)->ipv4.tcp_death_row.hashinfo;  in listening_get_next()
2382 	struct inet_hashinfo *hinfo = seq_file_net(seq)->ipv4.tcp_death_row.hashinfo;  in established_get_first()
2408 	struct inet_hashinfo *hinfo = seq_file_net(seq)->ipv4.tcp_death_row.hashinfo;  in established_get_next()
2461 	struct inet_hashinfo *hinfo = seq_file_net(seq)->ipv4.tcp_death_row.hashinfo;  in tcp_seek_last_pos()
2550 	struct inet_hashinfo *hinfo = seq_file_net(seq)->ipv4.tcp_death_row.hashinfo;  in tcp_seq_stop()
2755 	struct inet_hashinfo *hinfo = seq_file_net(seq)->ipv4.tcp_death_row.hashinfo;  in bpf_iter_tcp_listening_batch()
2783 	struct inet_hashinfo *hinfo = seq_file_net(seq)->ipv4.tcp_death_row.hashinfo;  in bpf_iter_tcp_established_batch()
2810 	struct inet_hashinfo *hinfo = seq_file_net(seq)->ipv4.tcp_death_row.hashinfo;  in bpf_iter_tcp_batch()
3084 	.sysctl_wmem_offset	= offsetof(struct net, ipv4.sysctl_tcp_wmem),
3085 	.sysctl_rmem_offset	= offsetof(struct net, ipv4.sysctl_tcp_rmem),
3099 	if (net->ipv4.tcp_congestion_control)  in tcp_sk_exit()
3100 		bpf_module_put(net->ipv4.tcp_congestion_control,  in tcp_sk_exit()
3101 			       net->ipv4.tcp_congestion_control->owner);  in tcp_sk_exit()
3114 	ehash_entries = READ_ONCE(old_net->ipv4.sysctl_tcp_child_ehash_entries);  in tcp_set_hashinfo()
3129 	net->ipv4.tcp_death_row.hashinfo = hinfo;  in tcp_set_hashinfo()
3130 	net->ipv4.tcp_death_row.sysctl_max_tw_buckets = ehash_entries / 2;  in tcp_set_hashinfo()
3131 	net->ipv4.sysctl_max_syn_backlog = max(128U, ehash_entries / 128);  in tcp_set_hashinfo()
3136 	net->ipv4.sysctl_tcp_ecn = 2;  in tcp_sk_init()
3137 	net->ipv4.sysctl_tcp_ecn_fallback = 1;  in tcp_sk_init()
3139 	net->ipv4.sysctl_tcp_base_mss = TCP_BASE_MSS;  in tcp_sk_init()
3140 	net->ipv4.sysctl_tcp_min_snd_mss = TCP_MIN_SND_MSS;  in tcp_sk_init()
3141 	net->ipv4.sysctl_tcp_probe_threshold = TCP_PROBE_THRESHOLD;  in tcp_sk_init()
3142 	net->ipv4.sysctl_tcp_probe_interval = TCP_PROBE_INTERVAL;  in tcp_sk_init()
3143 	net->ipv4.sysctl_tcp_mtu_probe_floor = TCP_MIN_SND_MSS;  in tcp_sk_init()
3145 	net->ipv4.sysctl_tcp_keepalive_time = TCP_KEEPALIVE_TIME;  in tcp_sk_init()
3146 	net->ipv4.sysctl_tcp_keepalive_probes = TCP_KEEPALIVE_PROBES;  in tcp_sk_init()
3147 	net->ipv4.sysctl_tcp_keepalive_intvl = TCP_KEEPALIVE_INTVL;  in tcp_sk_init()
3149 	net->ipv4.sysctl_tcp_syn_retries = TCP_SYN_RETRIES;  in tcp_sk_init()
3150 	net->ipv4.sysctl_tcp_synack_retries = TCP_SYNACK_RETRIES;  in tcp_sk_init()
3151 	net->ipv4.sysctl_tcp_syncookies = 1;  in tcp_sk_init()
3152 	net->ipv4.sysctl_tcp_reordering = TCP_FASTRETRANS_THRESH;  in tcp_sk_init()
3153 	net->ipv4.sysctl_tcp_retries1 = TCP_RETR1;  in tcp_sk_init()
3154 	net->ipv4.sysctl_tcp_retries2 = TCP_RETR2;  in tcp_sk_init()
3155 	net->ipv4.sysctl_tcp_orphan_retries = 0;  in tcp_sk_init()
3156 	net->ipv4.sysctl_tcp_fin_timeout = TCP_FIN_TIMEOUT;  in tcp_sk_init()
3157 	net->ipv4.sysctl_tcp_notsent_lowat = UINT_MAX;  in tcp_sk_init()
3158 	net->ipv4.sysctl_tcp_tw_reuse = 2;  in tcp_sk_init()
3159 	net->ipv4.sysctl_tcp_no_ssthresh_metrics_save = 1;  in tcp_sk_init()
3161 	refcount_set(&net->ipv4.tcp_death_row.tw_refcount, 1);  in tcp_sk_init()
3164 	net->ipv4.sysctl_tcp_sack = 1;  in tcp_sk_init()
3165 	net->ipv4.sysctl_tcp_window_scaling = 1;  in tcp_sk_init()
3166 	net->ipv4.sysctl_tcp_timestamps = 1;  in tcp_sk_init()
3167 	net->ipv4.sysctl_tcp_early_retrans = 3;  in tcp_sk_init()
3168 	net->ipv4.sysctl_tcp_recovery = TCP_RACK_LOSS_DETECTION;  in tcp_sk_init()
3169 	net->ipv4.sysctl_tcp_slow_start_after_idle = 1; /* By default, RFC2861 behavior.  */  in tcp_sk_init()
3170 	net->ipv4.sysctl_tcp_retrans_collapse = 1;  in tcp_sk_init()
3171 	net->ipv4.sysctl_tcp_max_reordering = 300;  in tcp_sk_init()
3172 	net->ipv4.sysctl_tcp_dsack = 1;  in tcp_sk_init()
3173 	net->ipv4.sysctl_tcp_app_win = 31;  in tcp_sk_init()
3174 	net->ipv4.sysctl_tcp_adv_win_scale = 1;  in tcp_sk_init()
3175 	net->ipv4.sysctl_tcp_frto = 2;  in tcp_sk_init()
3176 	net->ipv4.sysctl_tcp_moderate_rcvbuf = 1;  in tcp_sk_init()
3181 	net->ipv4.sysctl_tcp_tso_win_divisor = 3;  in tcp_sk_init()
3183 	net->ipv4.sysctl_tcp_limit_output_bytes = 16 * 65536;  in tcp_sk_init()
3186 	net->ipv4.sysctl_tcp_challenge_ack_limit = INT_MAX;  in tcp_sk_init()
3188 	net->ipv4.sysctl_tcp_min_tso_segs = 2;  in tcp_sk_init()
3189 	net->ipv4.sysctl_tcp_tso_rtt_log = 9;  /* 2^9 = 512 usec */  in tcp_sk_init()
3190 	net->ipv4.sysctl_tcp_min_rtt_wlen = 300;  in tcp_sk_init()
3191 	net->ipv4.sysctl_tcp_autocorking = 1;  in tcp_sk_init()
3192 	net->ipv4.sysctl_tcp_invalid_ratelimit = HZ/2;  in tcp_sk_init()
3193 	net->ipv4.sysctl_tcp_pacing_ss_ratio = 200;  in tcp_sk_init()
3194 	net->ipv4.sysctl_tcp_pacing_ca_ratio = 120;  in tcp_sk_init()
3196 		memcpy(net->ipv4.sysctl_tcp_rmem,  in tcp_sk_init()
3197 		       init_net.ipv4.sysctl_tcp_rmem,  in tcp_sk_init()
3198 		       sizeof(init_net.ipv4.sysctl_tcp_rmem));  in tcp_sk_init()
3199 		memcpy(net->ipv4.sysctl_tcp_wmem,  in tcp_sk_init()
3200 		       init_net.ipv4.sysctl_tcp_wmem,  in tcp_sk_init()
3201 		       sizeof(init_net.ipv4.sysctl_tcp_wmem));  in tcp_sk_init()
3203 	net->ipv4.sysctl_tcp_comp_sack_delay_ns = NSEC_PER_MSEC;  in tcp_sk_init()
3204 	net->ipv4.sysctl_tcp_comp_sack_slack_ns = 100 * NSEC_PER_USEC;  in tcp_sk_init()
3205 	net->ipv4.sysctl_tcp_comp_sack_nr = 44;  in tcp_sk_init()
3206 	net->ipv4.sysctl_tcp_fastopen = TFO_CLIENT_ENABLE;  in tcp_sk_init()
3207 	net->ipv4.sysctl_tcp_fastopen_blackhole_timeout = 0;  in tcp_sk_init()
3208 	atomic_set(&net->ipv4.tfo_active_disable_times, 0);  in tcp_sk_init()
3212 	    bpf_try_module_get(init_net.ipv4.tcp_congestion_control,  in tcp_sk_init()
3213 			       init_net.ipv4.tcp_congestion_control->owner))  in tcp_sk_init()
3214 		net->ipv4.tcp_congestion_control = init_net.ipv4.tcp_congestion_control;  in tcp_sk_init()
3216 		net->ipv4.tcp_congestion_control = &tcp_reno;  in tcp_sk_init()
3228 		inet_pernet_hashinfo_free(net->ipv4.tcp_death_row.hashinfo);  in tcp_sk_exit_batch()
3229 		WARN_ON_ONCE(!refcount_dec_and_test(&net->ipv4.tcp_death_row.tw_refcount));  in tcp_sk_exit_batch()