diff options
| author | Pavel Emelyanov <xemul@parallels.com> | 2012-02-21 07:30:58 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-02-21 14:58:57 -0500 |
| commit | 3f518bf745cbd6007d8069100fb9cb09e960c872 (patch) | |
| tree | debbe9e9340d46080f1b82e4149a2427545c4aef /net | |
| parent | 4934b0329f7150dcb5f90506860e2db32274c755 (diff) | |
datagram: Add offset argument to __skb_recv_datagram
This one is only considered for MSG_PEEK flag and the value pointed by
it specifies where to start peeking bytes from. If the offset happens to
point into the middle of the returned skb, the offset within this skb is
put back to this very argument.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/datagram.c | 21 | ||||
| -rw-r--r-- | net/ipv4/udp.c | 4 | ||||
| -rw-r--r-- | net/ipv6/udp.c | 4 |
3 files changed, 17 insertions, 12 deletions
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 @@ out_noerr: * __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 @@ out_noerr: * 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; @@ -183,19 +185,22 @@ 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); - if (skb) + spin_unlock_irqrestore(&queue->lock, cpu_flags); return skb; + } + spin_unlock_irqrestore(&queue->lock, cpu_flags); /* User doesn't want to wait */ error = -EAGAIN; @@ -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; |