Commit f545a38f authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

net: add a limit parameter to sk_add_backlog() 



sk_add_backlog() & sk_rcvqueues_full() hard coded sk_rcvbuf as the
memory limit. We need to make this limit a parameter for TCP use.

No functional change expected in this patch, all callers still using the
old sk_rcvbuf limit.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Maciej Żenczykowski <maze@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Cc: Rick Jones <rick.jones2@hp.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b9898507

include/net/sock.h

+6 −4
Original line number Diff line number Diff line
@@ -709,17 +709,19 @@ static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb) 
 * Do not take into account this skb truesize,

 * to allow even a single big packet to come.

 */

static inline bool sk_rcvqueues_full(const struct sock *sk, const struct sk_buff *skb)

static inline bool sk_rcvqueues_full(const struct sock *sk, const struct sk_buff *skb,

				     unsigned int limit)

{

	unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);



	return qsize > sk->sk_rcvbuf;

	return qsize > limit;

}



/* The per-socket spinlock must be held here. */

static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb)

static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb,

					      unsigned int limit)

{

	if (sk_rcvqueues_full(sk, skb))

	if (sk_rcvqueues_full(sk, skb, limit))

		return -ENOBUFS;



	__sk_add_backlog(sk, skb);

net/core/sock.c

+2 −2
Original line number Diff line number Diff line
@@ -389,7 +389,7 @@ int sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested) 


	skb->dev = NULL;



	if (sk_rcvqueues_full(sk, skb)) {

	if (sk_rcvqueues_full(sk, skb, sk->sk_rcvbuf)) {

		atomic_inc(&sk->sk_drops);

		goto discard_and_relse;

	}
@@ -406,7 +406,7 @@ int sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested) 
		rc = sk_backlog_rcv(sk, skb);



		mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);

	} else if (sk_add_backlog(sk, skb)) {

	} else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {

		bh_unlock_sock(sk);

		atomic_inc(&sk->sk_drops);

		goto discard_and_relse;

net/ipv4/tcp_ipv4.c

+1 −1
Original line number Diff line number Diff line
@@ -1752,7 +1752,7 @@ process: 
			if (!tcp_prequeue(sk, skb))

				ret = tcp_v4_do_rcv(sk, skb);

		}

	} else if (unlikely(sk_add_backlog(sk, skb))) {

	} else if (unlikely(sk_add_backlog(sk, skb, sk->sk_rcvbuf))) {

		bh_unlock_sock(sk);

		NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);

		goto discard_and_relse;

net/ipv4/udp.c

+2 −2
Original line number Diff line number Diff line
@@ -1479,7 +1479,7 @@ int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 
		goto drop;





	if (sk_rcvqueues_full(sk, skb))

	if (sk_rcvqueues_full(sk, skb, sk->sk_rcvbuf))

		goto drop;



	rc = 0;
@@ -1488,7 +1488,7 @@ int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 
	bh_lock_sock(sk);

	if (!sock_owned_by_user(sk))

		rc = __udp_queue_rcv_skb(sk, skb);

	else if (sk_add_backlog(sk, skb)) {

	else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {

		bh_unlock_sock(sk);

		goto drop;

	}

net/ipv6/tcp_ipv6.c

+1 −1
Original line number Diff line number Diff line
@@ -1654,7 +1654,7 @@ process: 
			if (!tcp_prequeue(sk, skb))

				ret = tcp_v6_do_rcv(sk, skb);

		}

	} else if (unlikely(sk_add_backlog(sk, skb))) {

	} else if (unlikely(sk_add_backlog(sk, skb, sk->sk_rcvbuf))) {

		bh_unlock_sock(sk);

		NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);

		goto discard_and_relse;

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