[ 08/74] NFC: llcp: Fix non blocking sockets connections

From: Greg Kroah-Hartman
Date: Mon Aug 26 2013 - 21:19:27 EST


3.10-stable review patch. If anyone has any objections, please let me know.

------------------

From: Samuel Ortiz <sameo@xxxxxxxxxxxxxxx>

commit b4011239a08e7e6c2c6e970dfa9e8ecb73139261 upstream.

Without the new LLCP_CONNECTING state, non blocking sockets will be
woken up with a POLLHUP right after calling connect() because their
state is stuck at LLCP_CLOSED.
That prevents userspace from implementing any proper non blocking
socket based NFC p2p client.

Signed-off-by: Samuel Ortiz <sameo@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
net/nfc/llcp.h | 1 +
net/nfc/llcp_sock.c | 8 +++++---
2 files changed, 6 insertions(+), 3 deletions(-)

--- a/net/nfc/llcp.h
+++ b/net/nfc/llcp.h
@@ -19,6 +19,7 @@

enum llcp_state {
LLCP_CONNECTED = 1, /* wait_for_packet() wants that */
+ LLCP_CONNECTING,
LLCP_CLOSED,
LLCP_BOUND,
LLCP_LISTEN,
--- a/net/nfc/llcp_sock.c
+++ b/net/nfc/llcp_sock.c
@@ -571,7 +571,7 @@ static unsigned int llcp_sock_poll(struc
if (sk->sk_shutdown == SHUTDOWN_MASK)
mask |= POLLHUP;

- if (sock_writeable(sk))
+ if (sock_writeable(sk) && sk->sk_state == LLCP_CONNECTED)
mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
else
set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
@@ -722,14 +722,16 @@ static int llcp_sock_connect(struct sock
if (ret)
goto sock_unlink;

+ sk->sk_state = LLCP_CONNECTING;
+
ret = sock_wait_state(sk, LLCP_CONNECTED,
sock_sndtimeo(sk, flags & O_NONBLOCK));
- if (ret)
+ if (ret && ret != -EINPROGRESS)
goto sock_unlink;

release_sock(sk);

- return 0;
+ return ret;

sock_unlink:
nfc_llcp_put_ssap(local, llcp_sock->ssap);


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