diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 2b7317ff297f..f3cf43de3c2a 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -2046,7 +2046,7 @@ static inline void skb_frag_add_head(struct sk_buff *skb, struct sk_buff *frag) for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next) extern struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags, - int *peeked, int *err); + int *peeked, int *off, int *err); extern struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags, int noblock, int *err); extern unsigned int datagram_poll(struct file *file, struct socket *sock, diff --git a/net/core/datagram.c b/net/core/datagram.c index 6f54d0a17f8e..d3cf12f62c8f 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -132,6 +132,8 @@ static int wait_for_packet(struct sock *sk, int *err, long *timeo_p) * __skb_recv_datagram - Receive a datagram skbuff * @sk: socket * @flags: MSG_ flags + * @off: an offset in bytes to peek skb from. Returns an offset + * within an skb where data actually starts * @peeked: returns non-zero if this packet has been seen before * @err: error code returned * @@ -158,7 +160,7 @@ static int wait_for_packet(struct sock *sk, int *err, long *timeo_p) * the standard around please. */ struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags, - int *peeked, int *err) + int *peeked, int *off, int *err) { struct sk_buff *skb; long timeo; @@ -183,20 +185,23 @@ struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags, struct sk_buff_head *queue = &sk->sk_receive_queue; spin_lock_irqsave(&queue->lock, cpu_flags); - skb = skb_peek(queue); - if (skb) { + skb_queue_walk(queue, skb) { *peeked = skb->peeked; if (flags & MSG_PEEK) { + if (*off >= skb->len) { + *off -= skb->len; + continue; + } skb->peeked = 1; atomic_inc(&skb->users); } else __skb_unlink(skb, queue); + + spin_unlock_irqrestore(&queue->lock, cpu_flags); + return skb; } spin_unlock_irqrestore(&queue->lock, cpu_flags); - if (skb) - return skb; - /* User doesn't want to wait */ error = -EAGAIN; if (!timeo) @@ -215,10 +220,10 @@ EXPORT_SYMBOL(__skb_recv_datagram); struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags, int noblock, int *err) { - int peeked; + int peeked, off = 0; return __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0), - &peeked, err); + &peeked, &off, err); } EXPORT_SYMBOL(skb_recv_datagram); diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index cd99f1a0f59f..7c41ab84e72e 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1167,7 +1167,7 @@ int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name; struct sk_buff *skb; unsigned int ulen, copied; - int peeked; + int peeked, off = 0; int err; int is_udplite = IS_UDPLITE(sk); bool slow; @@ -1183,7 +1183,7 @@ int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, try_again: skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0), - &peeked, &err); + &peeked, &off, &err); if (!skb) goto out; diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 8aebf8f90436..37b0699e95e5 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -342,7 +342,7 @@ int udpv6_recvmsg(struct kiocb *iocb, struct sock *sk, struct inet_sock *inet = inet_sk(sk); struct sk_buff *skb; unsigned int ulen, copied; - int peeked; + int peeked, off = 0; int err; int is_udplite = IS_UDPLITE(sk); int is_udp4; @@ -359,7 +359,7 @@ int udpv6_recvmsg(struct kiocb *iocb, struct sock *sk, try_again: skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0), - &peeked, &err); + &peeked, &off, &err); if (!skb) goto out;