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: Eric 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: David S. Miller <davem@davemloft.net>

10 files changed, 21 insertions, 19 deletions

diff --git a/include/net/sock.h b/include/net/sock.h
index 4cdb9b3050f4..4e9d01e491d5 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -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);
diff --git a/net/core/sock.c b/net/core/sock.c
index 679c5bbe2bed..0431aaf7473a 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -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;
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 0883921b20c1..917607e9bd5b 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -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;
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 3430e8fc18de..279fd0846302 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -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;
         }
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 8044f6ac1301..b04e6d8a8371 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -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;
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 37b0699e95e5..d39bbc9e0622 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -611,14 +611,14 @@ static void flush_stack(struct sock **stack, unsigned int count,
 
                 sk = stack[i];
                 if (skb1) {
-                        if (sk_rcvqueues_full(sk, skb1)) {
+                        if (sk_rcvqueues_full(sk, skb1, sk->sk_rcvbuf)) {
                                 kfree_skb(skb1);
                                 goto drop;
                         }
                         bh_lock_sock(sk);
                         if (!sock_owned_by_user(sk))
                                 udpv6_queue_rcv_skb(sk, skb1);
-                        else if (sk_add_backlog(sk, skb1)) {
+                        else if (sk_add_backlog(sk, skb1, sk->sk_rcvbuf)) {
                                 kfree_skb(skb1);
                                 bh_unlock_sock(sk);
                                 goto drop;
@@ -790,14 +790,14 @@ int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
 
         /* deliver */
 
-        if (sk_rcvqueues_full(sk, skb)) {
+        if (sk_rcvqueues_full(sk, skb, sk->sk_rcvbuf)) {
                 sock_put(sk);
                 goto discard;
         }
         bh_lock_sock(sk);
         if (!sock_owned_by_user(sk))
                 udpv6_queue_rcv_skb(sk, skb);
-        else if (sk_add_backlog(sk, skb)) {
+        else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
                 atomic_inc(&sk->sk_drops);
                 bh_unlock_sock(sk);
                 sock_put(sk);
diff --git a/net/llc/llc_conn.c b/net/llc/llc_conn.c
index ba137a6a224d..0d0d416dfab6 100644
--- a/net/llc/llc_conn.c
+++ b/net/llc/llc_conn.c
@@ -828,7 +828,7 @@ void llc_conn_handler(struct llc_sap *sap, struct sk_buff *skb)
         else {
                 dprintk("%s: adding to backlog...\n", __func__);
                 llc_set_backlog_type(skb, LLC_PACKET);
-                if (sk_add_backlog(sk, skb))
+                if (sk_add_backlog(sk, skb, sk->sk_rcvbuf))
                         goto drop_unlock;
         }
 out:
diff --git a/net/sctp/input.c b/net/sctp/input.c
index 80f71af71384..80564fe03024 100644
--- a/net/sctp/input.c
+++ b/net/sctp/input.c
@@ -342,7 +342,7 @@ int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb)
                 sctp_bh_lock_sock(sk);
 
                 if (sock_owned_by_user(sk)) {
-                        if (sk_add_backlog(sk, skb))
+                        if (sk_add_backlog(sk, skb, sk->sk_rcvbuf))
                                 sctp_chunk_free(chunk);
                         else
                                 backloged = 1;
@@ -376,7 +376,7 @@ static int sctp_add_backlog(struct sock *sk, struct sk_buff *skb)
         struct sctp_ep_common *rcvr = chunk->rcvr;
         int ret;
 
-        ret = sk_add_backlog(sk, skb);
+        ret = sk_add_backlog(sk, skb, sk->sk_rcvbuf);
         if (!ret) {
                 /* Hold the assoc/ep while hanging on the backlog queue.
                  * This way, we know structures we need will not disappear
diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index c19fc4a228a8..6d4991e8f670 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -1330,7 +1330,7 @@ static u32 dispatch(struct tipc_port *tport, struct sk_buff *buf)
         if (!sock_owned_by_user(sk)) {
                 res = filter_rcv(sk, buf);
         } else {
-                if (sk_add_backlog(sk, buf))
+                if (sk_add_backlog(sk, buf, sk->sk_rcvbuf))
                         res = TIPC_ERR_OVERLOAD;
                 else
                         res = TIPC_OK;
diff --git a/net/x25/x25_dev.c b/net/x25/x25_dev.c
index f0ce862d1f46..a8a236338e61 100644
--- a/net/x25/x25_dev.c
+++ b/net/x25/x25_dev.c
@@ -58,7 +58,7 @@ static int x25_receive_data(struct sk_buff *skb, struct x25_neigh *nb)
                 if (!sock_owned_by_user(sk)) {
                         queued = x25_process_rx_frame(sk, skb);
                 } else {
-                        queued = !sk_add_backlog(sk, skb);
+                        queued = !sk_add_backlog(sk, skb, sk->sk_rcvbuf);
                 }
                 bh_unlock_sock(sk);
                 sock_put(sk);