1 files changed, 50 insertions, 13 deletions

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 7158d4f8dae4..2259114c7242 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -86,7 +86,6 @@
 
 int sysctl_tcp_tw_reuse __read_mostly;
 int sysctl_tcp_low_latency __read_mostly;
-EXPORT_SYMBOL(sysctl_tcp_low_latency);
 
 #ifdef CONFIG_TCP_MD5SIG
 static int tcp_v4_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
@@ -1175,6 +1174,7 @@ static bool tcp_v4_inbound_md5_hash(const struct sock *sk,
 				      NULL, skb);
 
 	if (genhash || memcmp(hash_location, newhash, 16) != 0) {
+		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5FAILURE);
 		net_info_ratelimited("MD5 Hash failed for (%pI4, %d)->(%pI4, %d)%s\n",
 				     &iph->saddr, ntohs(th->source),
 				     &iph->daddr, ntohs(th->dest),
@@ -1195,7 +1195,6 @@ static void tcp_v4_init_req(struct request_sock *req,
 
 	sk_rcv_saddr_set(req_to_sk(req), ip_hdr(skb)->daddr);
 	sk_daddr_set(req_to_sk(req), ip_hdr(skb)->saddr);
-	ireq->no_srccheck = inet_sk(sk_listener)->transparent;
 	ireq->opt = tcp_v4_save_options(skb);
 }
 
@@ -1537,6 +1536,49 @@ bool tcp_prequeue(struct sock *sk, struct sk_buff *skb)
 }
 EXPORT_SYMBOL(tcp_prequeue);
 
+bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb)
+{
+	u32 limit = sk->sk_rcvbuf + sk->sk_sndbuf;
+
+	/* Only socket owner can try to collapse/prune rx queues
+	 * to reduce memory overhead, so add a little headroom here.
+	 * Few sockets backlog are possibly concurrently non empty.
+	 */
+	limit += 64*1024;
+
+	/* In case all data was pulled from skb frags (in __pskb_pull_tail()),
+	 * we can fix skb->truesize to its real value to avoid future drops.
+	 * This is valid because skb is not yet charged to the socket.
+	 * It has been noticed pure SACK packets were sometimes dropped
+	 * (if cooked by drivers without copybreak feature).
+	 */
+	if (!skb->data_len)
+		skb->truesize = SKB_TRUESIZE(skb_end_offset(skb));
+
+	if (unlikely(sk_add_backlog(sk, skb, limit))) {
+		bh_unlock_sock(sk);
+		__NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPBACKLOGDROP);
+		return true;
+	}
+	return false;
+}
+EXPORT_SYMBOL(tcp_add_backlog);
+
+int tcp_filter(struct sock *sk, struct sk_buff *skb)
+{
+	struct tcphdr *th = (struct tcphdr *)skb->data;
+	unsigned int eaten = skb->len;
+	int err;
+
+	err = sk_filter_trim_cap(sk, skb, th->doff * 4);
+	if (!err) {
+		eaten -= skb->len;
+		TCP_SKB_CB(skb)->end_seq -= eaten;
+	}
+	return err;
+}
+EXPORT_SYMBOL(tcp_filter);
+
 /*
  *	From tcp_input.c
  */
@@ -1608,6 +1650,7 @@ process:
 
 		sk = req->rsk_listener;
 		if (unlikely(tcp_v4_inbound_md5_hash(sk, skb))) {
+			sk_drops_add(sk, skb);
 			reqsk_put(req);
 			goto discard_it;
 		}
@@ -1648,8 +1691,10 @@ process:
 
 	nf_reset(skb);
 
-	if (sk_filter(sk, skb))
+	if (tcp_filter(sk, skb))
 		goto discard_and_relse;
+	th = (const struct tcphdr *)skb->data;
+	iph = ip_hdr(skb);
 
 	skb->dev = NULL;
 
@@ -1666,10 +1711,7 @@ process:
 	if (!sock_owned_by_user(sk)) {
 		if (!tcp_prequeue(sk, skb))
 			ret = tcp_v4_do_rcv(sk, skb);
-	} else if (unlikely(sk_add_backlog(sk, skb,
-					   sk->sk_rcvbuf + sk->sk_sndbuf))) {
-		bh_unlock_sock(sk);
-		__NET_INC_STATS(net, LINUX_MIB_TCPBACKLOGDROP);
+	} else if (tcp_add_backlog(sk, skb)) {
 		goto discard_and_relse;
 	}
 	bh_unlock_sock(sk);
@@ -1818,7 +1860,7 @@ void tcp_v4_destroy_sock(struct sock *sk)
 	tcp_write_queue_purge(sk);
 
 	/* Cleans up our, hopefully empty, out_of_order_queue. */
-	__skb_queue_purge(&tp->out_of_order_queue);
+	skb_rbtree_purge(&tp->out_of_order_queue);
 
 #ifdef CONFIG_TCP_MD5SIG
 	/* Clean up the MD5 key list, if any */
@@ -1845,9 +1887,6 @@ void tcp_v4_destroy_sock(struct sock *sk)
 	local_bh_disable();
 	sk_sockets_allocated_dec(sk);
 	local_bh_enable();
-
-	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
-		sock_release_memcg(sk);
 }
 EXPORT_SYMBOL(tcp_v4_destroy_sock);
 
@@ -1864,7 +1903,6 @@ static void *listening_get_next(struct seq_file *seq, void *cur)
 	struct tcp_iter_state *st = seq->private;
 	struct net *net = seq_file_net(seq);
 	struct inet_listen_hashbucket *ilb;
-	struct inet_connection_sock *icsk;
 	struct sock *sk = cur;
 
 	if (!sk) {
@@ -1886,7 +1924,6 @@ get_sk:
 			continue;
 		if (sk->sk_family == st->family)
 			return sk;
-		icsk = inet_csk(sk);
 	}
 	spin_unlock_bh(&ilb->lock);
 	st->offset = 0;