Messages in this thread Patches in this message | ![/](/images/icornerl.gif) | | Subject | [PATCH] select for UNIX sockets - 2.4 and 2.5 | From | Krzysztof Halasa <> | Date | 14 Jun 2003 17:29:43 +0200 |
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Hi,
The attached patches aims to fix select(write) on connect()ed UNIX datagram sockets. Without this patch, such select() is basically a NOP i.e. it returns immediately indicating a datagram can be written.
As I don't know this part of the kernel very well I'd appreciate it if you who know it better check the patch for correctness.
A simple test program is attached as well.
This patch doesn't fix select(write) on unconnect()ed sockets as there is no obvious way to check for socket state. -- Krzysztof Halasa Network Administrator --- linux-2.4.orig/net/unix/af_unix.c 2002-11-29 00:53:16.000000000 +0100 +++ linux-2.4/net/unix/af_unix.c 2003-06-14 17:04:26.000000000 +0200 @@ -1707,6 +1707,39 @@ return err; } +static unsigned int dgram_poll(struct file * file, struct socket *sock, + poll_table *wait) +{ + struct sock *sk = sock->sk; + unsigned int mask; + unix_socket *other; + + poll_wait(file, sk->sleep, wait); + mask = 0; + + /* exceptional events? */ + if (sk->err || !skb_queue_empty(&sk->error_queue)) + mask |= POLLERR; + if (sk->shutdown == SHUTDOWN_MASK) + mask |= POLLHUP; + + /* readable? */ + if (!skb_queue_empty(&sk->receive_queue) || + (sk->shutdown & RCV_SHUTDOWN)) + mask |= POLLIN | POLLRDNORM; + + /* writable? */ + other = unix_peer_get(sk); + if (sock_writeable(sk) && + (other == NULL || + skb_queue_len(&other->receive_queue) <= other->max_ack_backlog)) + mask |= POLLOUT | POLLWRNORM | POLLWRBAND; + else + set_bit(SOCK_ASYNC_NOSPACE, &sk->socket->flags); + + return mask; +} + static unsigned int unix_poll(struct file * file, struct socket *sock, poll_table *wait) { struct sock *sk = sock->sk; @@ -1836,7 +1869,7 @@ socketpair: unix_socketpair, accept: sock_no_accept, getname: unix_getname, - poll: datagram_poll, + poll: dgram_poll, ioctl: unix_ioctl, listen: sock_no_listen, shutdown: unix_shutdown,--- linux-2.5.orig/net/unix/af_unix.c 2003-05-27 03:00:41.000000000 +0200 +++ linux-2.5/net/unix/af_unix.c 2003-06-14 16:31:59.000000000 +0200 @@ -1784,6 +1784,39 @@ return err; } +static unsigned int dgram_poll(struct file * file, struct socket *sock, + poll_table *wait) +{ + struct sock *sk = sock->sk; + unsigned int mask; + unix_socket *other; + + poll_wait(file, sk->sleep, wait); + mask = 0; + + /* exceptional events? */ + if (sk->err || !skb_queue_empty(&sk->error_queue)) + mask |= POLLERR; + if (sk->shutdown == SHUTDOWN_MASK) + mask |= POLLHUP; + + /* readable? */ + if (!skb_queue_empty(&sk->receive_queue) || + (sk->shutdown & RCV_SHUTDOWN)) + mask |= POLLIN | POLLRDNORM; + + /* writable? */ + other = unix_peer_get(sk); + if (sock_writeable(sk) && + (other == NULL || + skb_queue_len(&other->receive_queue) <= other->max_ack_backlog)) + mask |= POLLOUT | POLLWRNORM | POLLWRBAND; + else + set_bit(SOCK_ASYNC_NOSPACE, &sk->socket->flags); + + return mask; +} + static unsigned int unix_poll(struct file * file, struct socket *sock, poll_table *wait) { struct sock *sk = sock->sk; @@ -1913,7 +1946,7 @@ .socketpair = unix_socketpair, .accept = sock_no_accept, .getname = unix_getname, - .poll = datagram_poll, + .poll = dgram_poll, .ioctl = unix_ioctl, .listen = sock_no_listen, .shutdown = unix_shutdown,[unhandled content-type:application/octet-stream] | ![\](/images/icornerr.gif) |