diff options
| author | samanthakumar <samanthakumar@google.com> | 2016-04-05 16:41:16 (GMT) |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-04-05 20:29:37 (GMT) |
| commit | 627d2d6b550094d88f9e518e15967e7bf906ebbf (patch) | |
| tree | 4a4d64af861781920b2b4ef6d0e7b4423b787292 /net/core/datagram.c | |
| parent | e6afc8ace6dd5cef5e812f26c72579da8806f5ac (diff) | |
| download | linux-627d2d6b550094d88f9e518e15967e7bf906ebbf.tar.xz | |
udp: enable MSG_PEEK at non-zero offset
Enable peeking at UDP datagrams at the offset specified with socket
option SOL_SOCKET/SO_PEEK_OFF. Peek at any datagram in the queue, up
to the end of the given datagram.
Implement the SO_PEEK_OFF semantics introduced in commit ef64a54f6e55
("sock: Introduce the SO_PEEK_OFF sock option"). Increase the offset
on peek, decrease it on regular reads.
When peeking, always checksum the packet immediately, to avoid
recomputation on subsequent peeks and final read.
The socket lock is not held for the duration of udp_recvmsg, so
peek and read operations can run concurrently. Only the last store
to sk_peek_off is preserved.
Signed-off-by: Sam Kumar <samanthakumar@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/datagram.c')
| -rw-r--r-- | net/core/datagram.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/net/core/datagram.c b/net/core/datagram.c index fa9dc64..b7de71f 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -301,16 +301,19 @@ void skb_free_datagram(struct sock *sk, struct sk_buff *skb) } EXPORT_SYMBOL(skb_free_datagram); -void skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb) +void __skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb, int len) { bool slow; if (likely(atomic_read(&skb->users) == 1)) smp_rmb(); - else if (likely(!atomic_dec_and_test(&skb->users))) + else if (likely(!atomic_dec_and_test(&skb->users))) { + sk_peek_offset_bwd(sk, len); return; + } slow = lock_sock_fast(sk); + sk_peek_offset_bwd(sk, len); skb_orphan(skb); sk_mem_reclaim_partial(sk); unlock_sock_fast(sk, slow); @@ -318,7 +321,7 @@ void skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb) /* skb is now orphaned, can be freed outside of locked section */ __kfree_skb(skb); } -EXPORT_SYMBOL(skb_free_datagram_locked); +EXPORT_SYMBOL(__skb_free_datagram_locked); /** * skb_kill_datagram - Free a datagram skbuff forcibly |