net: add queue argument to __skb_wait_for_more_packets and __skb_{,try_}recv_datagram

This will be used by ESP over TCP to handle the queue of IKE messages.
Signed-off-by: NSabrina Dubroca <sd@queasysnail.net>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

include/linux/skbuff.h

@@ -3459,7 +3459,8 @@ static inline void skb_frag_list_init(struct sk_buff *skb)
 	for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
 
 
-int __skb_wait_for_more_packets(struct sock *sk, int *err, long *timeo_p,
+int __skb_wait_for_more_packets(struct sock *sk, struct sk_buff_head *queue,
+				int *err, long *timeo_p,
 				const struct sk_buff *skb);
 struct sk_buff *__skb_try_recv_from_queue(struct sock *sk,
 					  struct sk_buff_head *queue,
@@ -3468,12 +3469,16 @@ struct sk_buff *__skb_try_recv_from_queue(struct sock *sk,
 							   struct sk_buff *skb),
 					  int *off, int *err,
 					  struct sk_buff **last);
-struct sk_buff *__skb_try_recv_datagram(struct sock *sk, unsigned flags,
+struct sk_buff *__skb_try_recv_datagram(struct sock *sk,
+					struct sk_buff_head *queue,
+					unsigned int flags,
 					void (*destructor)(struct sock *sk,
 							   struct sk_buff *skb),
 					int *off, int *err,
 					struct sk_buff **last);
-struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags,
+struct sk_buff *__skb_recv_datagram(struct sock *sk,
+				    struct sk_buff_head *sk_queue,
+				    unsigned int flags,
 				    void (*destructor)(struct sock *sk,
 						       struct sk_buff *skb),
 				    int *off, int *err);

net/core/datagram.c

@@ -84,7 +84,8 @@ static int receiver_wake_function(wait_queue_entry_t *wait, unsigned int mode, i
 /*
  * Wait for the last received packet to be different from skb
  */
-int __skb_wait_for_more_packets(struct sock *sk, int *err, long *timeo_p,
+int __skb_wait_for_more_packets(struct sock *sk, struct sk_buff_head *queue,
+				int *err, long *timeo_p,
 				const struct sk_buff *skb)
 {
 	int error;
@@ -97,7 +98,7 @@ int __skb_wait_for_more_packets(struct sock *sk, int *err, long *timeo_p,
 	if (error)
 		goto out_err;
 
-	if (READ_ONCE(sk->sk_receive_queue.prev) != skb)
+	if (READ_ONCE(queue->prev) != skb)
 		goto out;
 
 	/* Socket shut down? */
@@ -209,6 +210,7 @@ struct sk_buff *__skb_try_recv_from_queue(struct sock *sk,
 /**
  *	__skb_try_recv_datagram - Receive a datagram skbuff
  *	@sk: socket
+ *	@queue: socket queue from which to receive
  *	@flags: MSG\_ flags
  *	@destructor: invoked under the receive lock on successful dequeue
  *	@off: an offset in bytes to peek skb from. Returns an offset
@@ -241,13 +243,14 @@ struct sk_buff *__skb_try_recv_from_queue(struct sock *sk,
  *	quite explicitly by POSIX 1003.1g, don't change them without having
  *	the standard around please.
  */
-struct sk_buff *__skb_try_recv_datagram(struct sock *sk, unsigned int flags,
+struct sk_buff *__skb_try_recv_datagram(struct sock *sk,
+					struct sk_buff_head *queue,
+					unsigned int flags,
 					void (*destructor)(struct sock *sk,
 							   struct sk_buff *skb),
 					int *off, int *err,
 					struct sk_buff **last)
 {
-	struct sk_buff_head *queue = &sk->sk_receive_queue;
 	struct sk_buff *skb;
 	unsigned long cpu_flags;
 	/*
@@ -278,7 +281,7 @@ struct sk_buff *__skb_try_recv_datagram(struct sock *sk, unsigned int flags,
 			break;
 
 		sk_busy_loop(sk, flags & MSG_DONTWAIT);
-	} while (READ_ONCE(sk->sk_receive_queue.prev) != *last);
+	} while (READ_ONCE(queue->prev) != *last);
 
 	error = -EAGAIN;
 
@@ -288,7 +291,9 @@ struct sk_buff *__skb_try_recv_datagram(struct sock *sk, unsigned int flags,
 }
 EXPORT_SYMBOL(__skb_try_recv_datagram);
 
-struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned int flags,
+struct sk_buff *__skb_recv_datagram(struct sock *sk,
+				    struct sk_buff_head *sk_queue,
+				    unsigned int flags,
 				    void (*destructor)(struct sock *sk,
 						       struct sk_buff *skb),
 				    int *off, int *err)
@@ -299,15 +304,16 @@ struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned int flags,
 	timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
 
 	do {
-		skb = __skb_try_recv_datagram(sk, flags, destructor, off, err,
-					      &last);
+		skb = __skb_try_recv_datagram(sk, sk_queue, flags, destructor,
+					      off, err, &last);
 		if (skb)
 			return skb;
 
 		if (*err != -EAGAIN)
 			break;
 	} while (timeo &&
-		!__skb_wait_for_more_packets(sk, err, &timeo, last));
+		 !__skb_wait_for_more_packets(sk, sk_queue, err,
+					      &timeo, last));
 
 	return NULL;
 }
@@ -318,7 +324,8 @@ struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned int flags,
 {
 	int off = 0;
 
-	return __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
+	return __skb_recv_datagram(sk, &sk->sk_receive_queue,
+				   flags | (noblock ? MSG_DONTWAIT : 0),
 				   NULL, &off, err);
 }
 EXPORT_SYMBOL(skb_recv_datagram);

net/ipv4/udp.c

@@ -1708,7 +1708,8 @@ struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags,
 
 		/* sk_queue is empty, reader_queue may contain peeked packets */
 	} while (timeo &&
-		 !__skb_wait_for_more_packets(sk, &error, &timeo,
+		 !__skb_wait_for_more_packets(sk, &sk->sk_receive_queue,
+					      &error, &timeo,
 					      (struct sk_buff *)sk_queue));
 
 	*err = error;

net/unix/af_unix.c

@@ -2058,8 +2058,8 @@ static int unix_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
 		mutex_lock(&u->iolock);
 
 		skip = sk_peek_offset(sk, flags);
-		skb = __skb_try_recv_datagram(sk, flags, NULL, &skip, &err,
-					      &last);
+		skb = __skb_try_recv_datagram(sk, &sk->sk_receive_queue, flags,
+					      NULL, &skip, &err, &last);
 		if (skb)
 			break;
 
@@ -2068,7 +2068,8 @@ static int unix_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
 		if (err != -EAGAIN)
 			break;
 	} while (timeo &&
-		 !__skb_wait_for_more_packets(sk, &err, &timeo, last));
+		 !__skb_wait_for_more_packets(sk, &sk->sk_receive_queue,
+					      &err, &timeo, last));
 
 	if (!skb) { /* implies iolock unlocked */
 		unix_state_lock(sk);