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Commit a302afe9 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'robust_listener' 



Eric Dumazet says:

====================
tcp/dccp: make our listener code more robust

This patch series addresses request sockets leaks and listener dismantle
phase. This survives a stress test with listeners being added/removed
quite randomly.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 47ea0325 ebb516af

include/net/inet_connection_sock.h

+3 −7
Original line number Diff line number Diff line
@@ -268,13 +268,8 @@ struct dst_entry *inet_csk_route_child_sock(const struct sock *sk, 
					    struct sock *newsk,

					    const struct request_sock *req);



static inline void inet_csk_reqsk_queue_add(struct sock *sk,

					    struct request_sock *req,

					    struct sock *child)

{

	reqsk_queue_add(&inet_csk(sk)->icsk_accept_queue, req, sk, child);

}



void inet_csk_reqsk_queue_add(struct sock *sk, struct request_sock *req,

			      struct sock *child);

void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,

				   unsigned long timeout);
@@ -299,6 +294,7 @@ static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk) 
}



void inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req);

void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req);



void inet_csk_destroy_sock(struct sock *sk);

void inet_csk_prepare_forced_close(struct sock *sk);

include/net/request_sock.h

+0 −19
Original line number Diff line number Diff line
@@ -186,25 +186,6 @@ static inline bool reqsk_queue_empty(const struct request_sock_queue *queue) 
	return queue->rskq_accept_head == NULL;

}



static inline void reqsk_queue_add(struct request_sock_queue *queue,

				   struct request_sock *req,

				   struct sock *parent,

				   struct sock *child)

{

	spin_lock(&queue->rskq_lock);

	req->sk = child;

	sk_acceptq_added(parent);



	if (queue->rskq_accept_head == NULL)

		queue->rskq_accept_head = req;

	else

		queue->rskq_accept_tail->dl_next = req;



	queue->rskq_accept_tail = req;

	req->dl_next = NULL;

	spin_unlock(&queue->rskq_lock);

}



static inline struct request_sock *reqsk_queue_remove(struct request_sock_queue *queue,

						      struct sock *parent)

{

net/dccp/ipv4.c

+2 −2
Original line number Diff line number Diff line
@@ -208,7 +208,6 @@ void dccp_req_err(struct sock *sk, u64 seq) 


	if (!between48(seq, dccp_rsk(req)->dreq_iss, dccp_rsk(req)->dreq_gss)) {

		NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);

		reqsk_put(req);

	} else {

		/*

		 * Still in RESPOND, just remove it silently.
@@ -218,6 +217,7 @@ void dccp_req_err(struct sock *sk, u64 seq) 
		 */

		inet_csk_reqsk_queue_drop(req->rsk_listener, req);

	}

	reqsk_put(req);

}

EXPORT_SYMBOL(dccp_req_err);
@@ -828,7 +828,7 @@ static int dccp_v4_rcv(struct sk_buff *skb) 
		if (likely(sk->sk_state == DCCP_LISTEN)) {

			nsk = dccp_check_req(sk, skb, req);

		} else {

			inet_csk_reqsk_queue_drop(sk, req);

			inet_csk_reqsk_queue_drop_and_put(sk, req);

			goto lookup;

		}

		if (!nsk) {

net/dccp/ipv6.c

+1 −1
Original line number Diff line number Diff line
@@ -686,7 +686,7 @@ static int dccp_v6_rcv(struct sk_buff *skb) 
		if (likely(sk->sk_state == DCCP_LISTEN)) {

			nsk = dccp_check_req(sk, skb, req);

		} else {

			inet_csk_reqsk_queue_drop(sk, req);

			inet_csk_reqsk_queue_drop_and_put(sk, req);

			goto lookup;

		}

		if (!nsk) {

net/ipv4/inet_connection_sock.c

+57 −24
Original line number Diff line number Diff line
@@ -546,6 +546,13 @@ void inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req) 
}

EXPORT_SYMBOL(inet_csk_reqsk_queue_drop);



void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req)

{

	inet_csk_reqsk_queue_drop(sk, req);

	reqsk_put(req);

}

EXPORT_SYMBOL(inet_csk_reqsk_queue_drop_and_put);



static void reqsk_timer_handler(unsigned long data)

{

	struct request_sock *req = (struct request_sock *)data;
@@ -608,8 +615,7 @@ static void reqsk_timer_handler(unsigned long data) 
		return;

	}

drop:

	inet_csk_reqsk_queue_drop(sk_listener, req);

	reqsk_put(req);

	inet_csk_reqsk_queue_drop_and_put(sk_listener, req);

}



static void reqsk_queue_hash_req(struct request_sock *req,
@@ -758,6 +764,53 @@ int inet_csk_listen_start(struct sock *sk, int backlog) 
}

EXPORT_SYMBOL_GPL(inet_csk_listen_start);



static void inet_child_forget(struct sock *sk, struct request_sock *req,

			      struct sock *child)

{

	sk->sk_prot->disconnect(child, O_NONBLOCK);



	sock_orphan(child);



	percpu_counter_inc(sk->sk_prot->orphan_count);



	if (sk->sk_protocol == IPPROTO_TCP && tcp_rsk(req)->tfo_listener) {

		BUG_ON(tcp_sk(child)->fastopen_rsk != req);

		BUG_ON(sk != req->rsk_listener);



		/* Paranoid, to prevent race condition if

		 * an inbound pkt destined for child is

		 * blocked by sock lock in tcp_v4_rcv().

		 * Also to satisfy an assertion in

		 * tcp_v4_destroy_sock().

		 */

		tcp_sk(child)->fastopen_rsk = NULL;

	}

	inet_csk_destroy_sock(child);

	reqsk_put(req);

}



void inet_csk_reqsk_queue_add(struct sock *sk, struct request_sock *req,

			      struct sock *child)

{

	struct request_sock_queue *queue = &inet_csk(sk)->icsk_accept_queue;



	spin_lock(&queue->rskq_lock);

	if (unlikely(sk->sk_state != TCP_LISTEN)) {

		inet_child_forget(sk, req, child);

	} else {

		req->sk = child;

		req->dl_next = NULL;

		if (queue->rskq_accept_head == NULL)

			queue->rskq_accept_head = req;

		else

			queue->rskq_accept_tail->dl_next = req;

		queue->rskq_accept_tail = req;

		sk_acceptq_added(sk);

	}

	spin_unlock(&queue->rskq_lock);

}

EXPORT_SYMBOL(inet_csk_reqsk_queue_add);



/*

 *	This routine closes sockets which have been at least partially

 *	opened, but not yet accepted.
@@ -784,31 +837,11 @@ void inet_csk_listen_stop(struct sock *sk) 
		WARN_ON(sock_owned_by_user(child));

		sock_hold(child);



		sk->sk_prot->disconnect(child, O_NONBLOCK);



		sock_orphan(child);



		percpu_counter_inc(sk->sk_prot->orphan_count);



		if (sk->sk_protocol == IPPROTO_TCP && tcp_rsk(req)->tfo_listener) {

			BUG_ON(tcp_sk(child)->fastopen_rsk != req);

			BUG_ON(sk != req->rsk_listener);



			/* Paranoid, to prevent race condition if

			 * an inbound pkt destined for child is

			 * blocked by sock lock in tcp_v4_rcv().

			 * Also to satisfy an assertion in

			 * tcp_v4_destroy_sock().

			 */

			tcp_sk(child)->fastopen_rsk = NULL;

		}

		inet_csk_destroy_sock(child);



		inet_child_forget(sk, req, child);

		bh_unlock_sock(child);

		local_bh_enable();

		sock_put(child);



		reqsk_put(req);

		cond_resched();

	}

	if (queue->fastopenq.rskq_rst_head) {
@@ -823,7 +856,7 @@ void inet_csk_listen_stop(struct sock *sk) 
			req = next;

		}

	}

	WARN_ON(sk->sk_ack_backlog);

	WARN_ON_ONCE(sk->sk_ack_backlog);

}

EXPORT_SYMBOL_GPL(inet_csk_listen_stop);