1 files changed, 76 insertions, 65 deletions

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index f70586b50838..bea17f1e8302 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -110,8 +110,38 @@ static u32 tcp_v4_init_ts_off(const struct net *net, const struct sk_buff *skb)
 
 int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp)
 {
+	const struct inet_timewait_sock *tw = inet_twsk(sktw);
 	const struct tcp_timewait_sock *tcptw = tcp_twsk(sktw);
 	struct tcp_sock *tp = tcp_sk(sk);
+	int reuse = sock_net(sk)->ipv4.sysctl_tcp_tw_reuse;
+
+	if (reuse == 2) {
+		/* Still does not detect *everything* that goes through
+		 * lo, since we require a loopback src or dst address
+		 * or direct binding to 'lo' interface.
+		 */
+		bool loopback = false;
+		if (tw->tw_bound_dev_if == LOOPBACK_IFINDEX)
+			loopback = true;
+#if IS_ENABLED(CONFIG_IPV6)
+		if (tw->tw_family == AF_INET6) {
+			if (ipv6_addr_loopback(&tw->tw_v6_daddr) ||
+			    (ipv6_addr_v4mapped(&tw->tw_v6_daddr) &&
+			     (tw->tw_v6_daddr.s6_addr[12] == 127)) ||
+			    ipv6_addr_loopback(&tw->tw_v6_rcv_saddr) ||
+			    (ipv6_addr_v4mapped(&tw->tw_v6_rcv_saddr) &&
+			     (tw->tw_v6_rcv_saddr.s6_addr[12] == 127)))
+				loopback = true;
+		} else
+#endif
+		{
+			if (ipv4_is_loopback(tw->tw_daddr) ||
+			    ipv4_is_loopback(tw->tw_rcv_saddr))
+				loopback = true;
+		}
+		if (!loopback)
+			reuse = 0;
+	}
 
 	/* With PAWS, it is safe from the viewpoint
 	   of data integrity. Even without PAWS it is safe provided sequence
@@ -125,8 +155,7 @@ int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp)
 	   and use initial timestamp retrieved from peer table.
 	 */
 	if (tcptw->tw_ts_recent_stamp &&
-	    (!twp || (sock_net(sk)->ipv4.sysctl_tcp_tw_reuse &&
-			     get_seconds() - tcptw->tw_ts_recent_stamp > 1))) {
+	    (!twp || (reuse && get_seconds() - tcptw->tw_ts_recent_stamp > 1))) {
 		tp->write_seq = tcptw->tw_snd_nxt + 65535 + 2;
 		if (tp->write_seq == 0)
 			tp->write_seq = 1;
@@ -621,6 +650,7 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb)
 	struct sock *sk1 = NULL;
 #endif
 	struct net *net;
+	struct sock *ctl_sk;
 
 	/* Never send a reset in response to a reset. */
 	if (th->rst)
@@ -723,11 +753,16 @@ 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();
-	ip_send_unicast_reply(*this_cpu_ptr(net->ipv4.tcp_sk),
+	ctl_sk = *this_cpu_ptr(net->ipv4.tcp_sk);
+	if (sk)
+		ctl_sk->sk_mark = (sk->sk_state == TCP_TIME_WAIT) ?
+				   inet_twsk(sk)->tw_mark : sk->sk_mark;
+	ip_send_unicast_reply(ctl_sk,
 			      skb, &TCP_SKB_CB(skb)->header.h4.opt,
 			      ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
 			      &arg, arg.iov[0].iov_len);
 
+	ctl_sk->sk_mark = 0;
 	__TCP_INC_STATS(net, TCP_MIB_OUTSEGS);
 	__TCP_INC_STATS(net, TCP_MIB_OUTRSTS);
 	local_bh_enable();
@@ -759,6 +794,7 @@ static void tcp_v4_send_ack(const struct sock *sk,
 	} rep;
 	struct net *net = sock_net(sk);
 	struct ip_reply_arg arg;
+	struct sock *ctl_sk;
 
 	memset(&rep.th, 0, sizeof(struct tcphdr));
 	memset(&arg, 0, sizeof(arg));
@@ -809,11 +845,16 @@ 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();
-	ip_send_unicast_reply(*this_cpu_ptr(net->ipv4.tcp_sk),
+	ctl_sk = *this_cpu_ptr(net->ipv4.tcp_sk);
+	if (sk)
+		ctl_sk->sk_mark = (sk->sk_state == TCP_TIME_WAIT) ?
+				   inet_twsk(sk)->tw_mark : sk->sk_mark;
+	ip_send_unicast_reply(ctl_sk,
 			      skb, &TCP_SKB_CB(skb)->header.h4.opt,
 			      ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
 			      &arg, arg.iov[0].iov_len);
 
+	ctl_sk->sk_mark = 0;
 	__TCP_INC_STATS(net, TCP_MIB_OUTSEGS);
 	local_bh_enable();
 }
@@ -1474,7 +1515,7 @@ int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
 				sk->sk_rx_dst = NULL;
 			}
 		}
-		tcp_rcv_established(sk, skb, tcp_hdr(skb));
+		tcp_rcv_established(sk, skb);
 		return 0;
 	}
 
@@ -1689,6 +1730,10 @@ process:
 			reqsk_put(req);
 			goto discard_it;
 		}
+		if (tcp_checksum_complete(skb)) {
+			reqsk_put(req);
+			goto csum_error;
+		}
 		if (unlikely(sk->sk_state != TCP_LISTEN)) {
 			inet_csk_reqsk_queue_drop_and_put(sk, req);
 			goto lookup;
@@ -1961,6 +2006,7 @@ EXPORT_SYMBOL(tcp_v4_destroy_sock);
  */
 static void *listening_get_next(struct seq_file *seq, void *cur)
 {
+	struct tcp_seq_afinfo *afinfo = PDE_DATA(file_inode(seq->file));
 	struct tcp_iter_state *st = seq->private;
 	struct net *net = seq_file_net(seq);
 	struct inet_listen_hashbucket *ilb;
@@ -1983,7 +2029,7 @@ get_sk:
 	sk_for_each_from(sk) {
 		if (!net_eq(sock_net(sk), net))
 			continue;
-		if (sk->sk_family == st->family)
+		if (sk->sk_family == afinfo->family)
 			return sk;
 	}
 	spin_unlock(&ilb->lock);
@@ -2020,6 +2066,7 @@ static inline bool empty_bucket(const struct tcp_iter_state *st)
  */
 static void *established_get_first(struct seq_file *seq)
 {
+	struct tcp_seq_afinfo *afinfo = PDE_DATA(file_inode(seq->file));
 	struct tcp_iter_state *st = seq->private;
 	struct net *net = seq_file_net(seq);
 	void *rc = NULL;
@@ -2036,7 +2083,7 @@ static void *established_get_first(struct seq_file *seq)
 
 		spin_lock_bh(lock);
 		sk_nulls_for_each(sk, node, &tcp_hashinfo.ehash[st->bucket].chain) {
-			if (sk->sk_family != st->family ||
+			if (sk->sk_family != afinfo->family ||
 			    !net_eq(sock_net(sk), net)) {
 				continue;
 			}
@@ -2051,6 +2098,7 @@ out:
 
 static void *established_get_next(struct seq_file *seq, void *cur)
 {
+	struct tcp_seq_afinfo *afinfo = PDE_DATA(file_inode(seq->file));
 	struct sock *sk = cur;
 	struct hlist_nulls_node *node;
 	struct tcp_iter_state *st = seq->private;
@@ -2062,7 +2110,8 @@ static void *established_get_next(struct seq_file *seq, void *cur)
 	sk = sk_nulls_next(sk);
 
 	sk_nulls_for_each_from(sk, node) {
-		if (sk->sk_family == st->family && net_eq(sock_net(sk), net))
+		if (sk->sk_family == afinfo->family &&
+		    net_eq(sock_net(sk), net))
 			return sk;
 	}
 
@@ -2135,7 +2184,7 @@ static void *tcp_seek_last_pos(struct seq_file *seq)
 	return rc;
 }
 
-static void *tcp_seq_start(struct seq_file *seq, loff_t *pos)
+void *tcp_seq_start(struct seq_file *seq, loff_t *pos)
 {
 	struct tcp_iter_state *st = seq->private;
 	void *rc;
@@ -2156,8 +2205,9 @@ out:
 	st->last_pos = *pos;
 	return rc;
 }
+EXPORT_SYMBOL(tcp_seq_start);
 
-static void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
 	struct tcp_iter_state *st = seq->private;
 	void *rc = NULL;
@@ -2186,8 +2236,9 @@ out:
 	st->last_pos = *pos;
 	return rc;
 }
+EXPORT_SYMBOL(tcp_seq_next);
 
-static void tcp_seq_stop(struct seq_file *seq, void *v)
+void tcp_seq_stop(struct seq_file *seq, void *v)
 {
 	struct tcp_iter_state *st = seq->private;
 
@@ -2202,47 +2253,7 @@ static void tcp_seq_stop(struct seq_file *seq, void *v)
 		break;
 	}
 }
-
-int tcp_seq_open(struct inode *inode, struct file *file)
-{
-	struct tcp_seq_afinfo *afinfo = PDE_DATA(inode);
-	struct tcp_iter_state *s;
-	int err;
-
-	err = seq_open_net(inode, file, &afinfo->seq_ops,
-			  sizeof(struct tcp_iter_state));
-	if (err < 0)
-		return err;
-
-	s = ((struct seq_file *)file->private_data)->private;
-	s->family		= afinfo->family;
-	s->last_pos		= 0;
-	return 0;
-}
-EXPORT_SYMBOL(tcp_seq_open);
-
-int tcp_proc_register(struct net *net, struct tcp_seq_afinfo *afinfo)
-{
-	int rc = 0;
-	struct proc_dir_entry *p;
-
-	afinfo->seq_ops.start		= tcp_seq_start;
-	afinfo->seq_ops.next		= tcp_seq_next;
-	afinfo->seq_ops.stop		= tcp_seq_stop;
-
-	p = proc_create_data(afinfo->name, 0444, net->proc_net,
-			     afinfo->seq_fops, afinfo);
-	if (!p)
-		rc = -ENOMEM;
-	return rc;
-}
-EXPORT_SYMBOL(tcp_proc_register);
-
-void tcp_proc_unregister(struct net *net, struct tcp_seq_afinfo *afinfo)
-{
-	remove_proc_entry(afinfo->name, net->proc_net);
-}
-EXPORT_SYMBOL(tcp_proc_unregister);
+EXPORT_SYMBOL(tcp_seq_stop);
 
 static void get_openreq4(const struct request_sock *req,
 			 struct seq_file *f, int i)
@@ -2377,30 +2388,28 @@ out:
 	return 0;
 }
 
-static const struct file_operations tcp_afinfo_seq_fops = {
-	.open    = tcp_seq_open,
-	.read    = seq_read,
-	.llseek  = seq_lseek,
-	.release = seq_release_net
+static const struct seq_operations tcp4_seq_ops = {
+	.show		= tcp4_seq_show,
+	.start		= tcp_seq_start,
+	.next		= tcp_seq_next,
+	.stop		= tcp_seq_stop,
 };
 
 static struct tcp_seq_afinfo tcp4_seq_afinfo = {
-	.name		= "tcp",
 	.family		= AF_INET,
-	.seq_fops	= &tcp_afinfo_seq_fops,
-	.seq_ops	= {
-		.show		= tcp4_seq_show,
-	},
 };
 
 static int __net_init tcp4_proc_init_net(struct net *net)
 {
-	return tcp_proc_register(net, &tcp4_seq_afinfo);
+	if (!proc_create_net_data("tcp", 0444, net->proc_net, &tcp4_seq_ops,
+			sizeof(struct tcp_iter_state), &tcp4_seq_afinfo))
+		return -ENOMEM;
+	return 0;
 }
 
 static void __net_exit tcp4_proc_exit_net(struct net *net)
 {
-	tcp_proc_unregister(net, &tcp4_seq_afinfo);
+	remove_proc_entry("tcp", net->proc_net);
 }
 
 static struct pernet_operations tcp4_net_ops = {
@@ -2517,7 +2526,7 @@ static int __net_init tcp_sk_init(struct net *net)
 	net->ipv4.sysctl_tcp_orphan_retries = 0;
 	net->ipv4.sysctl_tcp_fin_timeout = TCP_FIN_TIMEOUT;
 	net->ipv4.sysctl_tcp_notsent_lowat = UINT_MAX;
-	net->ipv4.sysctl_tcp_tw_reuse = 0;
+	net->ipv4.sysctl_tcp_tw_reuse = 2;
 
 	cnt = tcp_hashinfo.ehash_mask + 1;
 	net->ipv4.tcp_death_row.sysctl_max_tw_buckets = (cnt + 1) / 2;
@@ -2560,6 +2569,8 @@ static int __net_init tcp_sk_init(struct net *net)
 		       init_net.ipv4.sysctl_tcp_wmem,
 		       sizeof(init_net.ipv4.sysctl_tcp_wmem));
 	}
+	net->ipv4.sysctl_tcp_comp_sack_delay_ns = NSEC_PER_MSEC;
+	net->ipv4.sysctl_tcp_comp_sack_nr = 44;
 	net->ipv4.sysctl_tcp_fastopen = TFO_CLIENT_ENABLE;
 	spin_lock_init(&net->ipv4.tcp_fastopen_ctx_lock);
 	net->ipv4.sysctl_tcp_fastopen_blackhole_timeout = 60 * 60;