1 files changed, 37 insertions, 38 deletions

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index fec656f5a39e..6873f46fc8ba 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -91,6 +91,8 @@ static int tcp_v4_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
 struct inet_hashinfo tcp_hashinfo;
 EXPORT_SYMBOL(tcp_hashinfo);
 
+static DEFINE_PER_CPU(struct sock *, ipv4_tcp_sk);
+
 static u32 tcp_v4_init_seq(const struct sk_buff *skb)
 {
 	return secure_tcp_seq(ip_hdr(skb)->daddr,
@@ -206,7 +208,7 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 	struct rtable *rt;
 	int err;
 	struct ip_options_rcu *inet_opt;
-	struct inet_timewait_death_row *tcp_death_row = &sock_net(sk)->ipv4.tcp_death_row;
+	struct inet_timewait_death_row *tcp_death_row = sock_net(sk)->ipv4.tcp_death_row;
 
 	if (addr_len < sizeof(struct sockaddr_in))
 		return -EINVAL;
@@ -810,7 +812,8 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb)
 	arg.tos = ip_hdr(skb)->tos;
 	arg.uid = sock_net_uid(net, sk && sk_fullsock(sk) ? sk : NULL);
 	local_bh_disable();
-	ctl_sk = this_cpu_read(*net->ipv4.tcp_sk);
+	ctl_sk = this_cpu_read(ipv4_tcp_sk);
+	sock_net_set(ctl_sk, net);
 	if (sk) {
 		ctl_sk->sk_mark = (sk->sk_state == TCP_TIME_WAIT) ?
 				   inet_twsk(sk)->tw_mark : sk->sk_mark;
@@ -825,6 +828,7 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb)
 			      transmit_time);
 
 	ctl_sk->sk_mark = 0;
+	sock_net_set(ctl_sk, &init_net);
 	__TCP_INC_STATS(net, TCP_MIB_OUTSEGS);
 	__TCP_INC_STATS(net, TCP_MIB_OUTRSTS);
 	local_bh_enable();
@@ -908,7 +912,8 @@ static void tcp_v4_send_ack(const struct sock *sk,
 	arg.tos = tos;
 	arg.uid = sock_net_uid(net, sk_fullsock(sk) ? sk : NULL);
 	local_bh_disable();
-	ctl_sk = this_cpu_read(*net->ipv4.tcp_sk);
+	ctl_sk = this_cpu_read(ipv4_tcp_sk);
+	sock_net_set(ctl_sk, net);
 	ctl_sk->sk_mark = (sk->sk_state == TCP_TIME_WAIT) ?
 			   inet_twsk(sk)->tw_mark : sk->sk_mark;
 	ctl_sk->sk_priority = (sk->sk_state == TCP_TIME_WAIT) ?
@@ -921,6 +926,7 @@ static void tcp_v4_send_ack(const struct sock *sk,
 			      transmit_time);
 
 	ctl_sk->sk_mark = 0;
+	sock_net_set(ctl_sk, &init_net);
 	__TCP_INC_STATS(net, TCP_MIB_OUTSEGS);
 	local_bh_enable();
 }
@@ -3111,41 +3117,18 @@ EXPORT_SYMBOL(tcp_prot);
 
 static void __net_exit tcp_sk_exit(struct net *net)
 {
-	int cpu;
+	struct inet_timewait_death_row *tcp_death_row = net->ipv4.tcp_death_row;
 
 	if (net->ipv4.tcp_congestion_control)
 		bpf_module_put(net->ipv4.tcp_congestion_control,
 			       net->ipv4.tcp_congestion_control->owner);
-
-	for_each_possible_cpu(cpu)
-		inet_ctl_sock_destroy(*per_cpu_ptr(net->ipv4.tcp_sk, cpu));
-	free_percpu(net->ipv4.tcp_sk);
+	if (refcount_dec_and_test(&tcp_death_row->tw_refcount))
+		kfree(tcp_death_row);
 }
 
 static int __net_init tcp_sk_init(struct net *net)
 {
-	int res, cpu, cnt;
-
-	net->ipv4.tcp_sk = alloc_percpu(struct sock *);
-	if (!net->ipv4.tcp_sk)
-		return -ENOMEM;
-
-	for_each_possible_cpu(cpu) {
-		struct sock *sk;
-
-		res = inet_ctl_sock_create(&sk, PF_INET, SOCK_RAW,
-					   IPPROTO_TCP, net);
-		if (res)
-			goto fail;
-		sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
-
-		/* Please enforce IP_DF and IPID==0 for RST and
-		 * ACK sent in SYN-RECV and TIME-WAIT state.
-		 */
-		inet_sk(sk)->pmtudisc = IP_PMTUDISC_DO;
-
-		*per_cpu_ptr(net->ipv4.tcp_sk, cpu) = sk;
-	}
+	int cnt;
 
 	net->ipv4.sysctl_tcp_ecn = 2;
 	net->ipv4.sysctl_tcp_ecn_fallback = 1;
@@ -3172,9 +3155,13 @@ static int __net_init tcp_sk_init(struct net *net)
 	net->ipv4.sysctl_tcp_tw_reuse = 2;
 	net->ipv4.sysctl_tcp_no_ssthresh_metrics_save = 1;
 
+	net->ipv4.tcp_death_row = kzalloc(sizeof(struct inet_timewait_death_row), GFP_KERNEL);
+	if (!net->ipv4.tcp_death_row)
+		return -ENOMEM;
+	refcount_set(&net->ipv4.tcp_death_row->tw_refcount, 1);
 	cnt = tcp_hashinfo.ehash_mask + 1;
-	net->ipv4.tcp_death_row.sysctl_max_tw_buckets = cnt / 2;
-	net->ipv4.tcp_death_row.hashinfo = &tcp_hashinfo;
+	net->ipv4.tcp_death_row->sysctl_max_tw_buckets = cnt / 2;
+	net->ipv4.tcp_death_row->hashinfo = &tcp_hashinfo;
 
 	net->ipv4.sysctl_max_syn_backlog = max(128, cnt / 128);
 	net->ipv4.sysctl_tcp_sack = 1;
@@ -3229,18 +3216,12 @@ static int __net_init tcp_sk_init(struct net *net)
 		net->ipv4.tcp_congestion_control = &tcp_reno;
 
 	return 0;
-fail:
-	tcp_sk_exit(net);
-
-	return res;
 }
 
 static void __net_exit tcp_sk_exit_batch(struct list_head *net_exit_list)
 {
 	struct net *net;
 
-	inet_twsk_purge(&tcp_hashinfo, AF_INET);
-
 	list_for_each_entry(net, net_exit_list, exit_list)
 		tcp_fastopen_ctx_destroy(net);
 }
@@ -3326,6 +3307,24 @@ static void __init bpf_iter_register(void)
 
 void __init tcp_v4_init(void)
 {
+	int cpu, res;
+
+	for_each_possible_cpu(cpu) {
+		struct sock *sk;
+
+		res = inet_ctl_sock_create(&sk, PF_INET, SOCK_RAW,
+					   IPPROTO_TCP, &init_net);
+		if (res)
+			panic("Failed to create the TCP control socket.\n");
+		sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
+
+		/* Please enforce IP_DF and IPID==0 for RST and
+		 * ACK sent in SYN-RECV and TIME-WAIT state.
+		 */
+		inet_sk(sk)->pmtudisc = IP_PMTUDISC_DO;
+
+		per_cpu(ipv4_tcp_sk, cpu) = sk;
+	}
 	if (register_pernet_subsys(&tcp_sk_ops))
 		panic("Failed to create the TCP control socket.\n");