diff options
Diffstat (limited to 'net/core/stream.c')
| -rw-r--r-- | net/core/stream.c | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/net/core/stream.c b/net/core/stream.c new file mode 100644 index 00000000..f5df85dc --- /dev/null +++ b/net/core/stream.c @@ -0,0 +1,208 @@ +/* + * SUCS NET3: + * + * Generic stream handling routines. These are generic for most + * protocols. Even IP. Tonight 8-). + * This is used because TCP, LLC (others too) layer all have mostly + * identical sendmsg() and recvmsg() code. + * So we (will) share it here. + * + * Authors: Arnaldo Carvalho de Melo <acme@conectiva.com.br> + * (from old tcp.c code) + * Alan Cox <alan@lxorguk.ukuu.org.uk> (Borrowed comments 8-)) + */ + +#include <linux/module.h> +#include <linux/net.h> +#include <linux/signal.h> +#include <linux/tcp.h> +#include <linux/wait.h> +#include <net/sock.h> + +/** + * sk_stream_write_space - stream socket write_space callback. + * @sk: socket + * + * FIXME: write proper description + */ +void sk_stream_write_space(struct sock *sk) +{ + struct socket *sock = sk->sk_socket; + struct socket_wq *wq; + + if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) && sock) { + clear_bit(SOCK_NOSPACE, &sock->flags); + + rcu_read_lock(); + wq = rcu_dereference(sk->sk_wq); + if (wq_has_sleeper(wq)) + wake_up_interruptible_poll(&wq->wait, POLLOUT | + POLLWRNORM | POLLWRBAND); + if (wq && wq->fasync_list && !(sk->sk_shutdown & SEND_SHUTDOWN)) + sock_wake_async(sock, SOCK_WAKE_SPACE, POLL_OUT); + rcu_read_unlock(); + } +} +EXPORT_SYMBOL(sk_stream_write_space); + +/** + * sk_stream_wait_connect - Wait for a socket to get into the connected state + * @sk: sock to wait on + * @timeo_p: for how long to wait + * + * Must be called with the socket locked. + */ +int sk_stream_wait_connect(struct sock *sk, long *timeo_p) +{ + struct task_struct *tsk = current; + DEFINE_WAIT(wait); + int done; + + do { + int err = sock_error(sk); + if (err) + return err; + if ((1 << sk->sk_state) & ~(TCPF_SYN_SENT | TCPF_SYN_RECV)) + return -EPIPE; + if (!*timeo_p) + return -EAGAIN; + if (signal_pending(tsk)) + return sock_intr_errno(*timeo_p); + + prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); + sk->sk_write_pending++; + done = sk_wait_event(sk, timeo_p, + !sk->sk_err && + !((1 << sk->sk_state) & + ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT))); + finish_wait(sk_sleep(sk), &wait); + sk->sk_write_pending--; + } while (!done); + return 0; +} +EXPORT_SYMBOL(sk_stream_wait_connect); + +/** + * sk_stream_closing - Return 1 if we still have things to send in our buffers. + * @sk: socket to verify + */ +static inline int sk_stream_closing(struct sock *sk) +{ + return (1 << sk->sk_state) & + (TCPF_FIN_WAIT1 | TCPF_CLOSING | TCPF_LAST_ACK); +} + +void sk_stream_wait_close(struct sock *sk, long timeout) +{ + if (timeout) { + DEFINE_WAIT(wait); + + do { + prepare_to_wait(sk_sleep(sk), &wait, + TASK_INTERRUPTIBLE); + if (sk_wait_event(sk, &timeout, !sk_stream_closing(sk))) + break; + } while (!signal_pending(current) && timeout); + + finish_wait(sk_sleep(sk), &wait); + } +} +EXPORT_SYMBOL(sk_stream_wait_close); + +/** + * sk_stream_wait_memory - Wait for more memory for a socket + * @sk: socket to wait for memory + * @timeo_p: for how long + */ +int sk_stream_wait_memory(struct sock *sk, long *timeo_p) +{ + int err = 0; + long vm_wait = 0; + long current_timeo = *timeo_p; + DEFINE_WAIT(wait); + + if (sk_stream_memory_free(sk)) + current_timeo = vm_wait = (net_random() % (HZ / 5)) + 2; + + while (1) { + set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); + + prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); + + if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) + goto do_error; + if (!*timeo_p) + goto do_nonblock; + if (signal_pending(current)) + goto do_interrupted; + clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); + if (sk_stream_memory_free(sk) && !vm_wait) + break; + + set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); + sk->sk_write_pending++; + sk_wait_event(sk, ¤t_timeo, sk->sk_err || + (sk->sk_shutdown & SEND_SHUTDOWN) || + (sk_stream_memory_free(sk) && + !vm_wait)); + sk->sk_write_pending--; + + if (vm_wait) { + vm_wait -= current_timeo; + current_timeo = *timeo_p; + if (current_timeo != MAX_SCHEDULE_TIMEOUT && + (current_timeo -= vm_wait) < 0) + current_timeo = 0; + vm_wait = 0; + } + *timeo_p = current_timeo; + } +out: + finish_wait(sk_sleep(sk), &wait); + return err; + +do_error: + err = -EPIPE; + goto out; +do_nonblock: + err = -EAGAIN; + goto out; +do_interrupted: + err = sock_intr_errno(*timeo_p); + goto out; +} +EXPORT_SYMBOL(sk_stream_wait_memory); + +int sk_stream_error(struct sock *sk, int flags, int err) +{ + if (err == -EPIPE) + err = sock_error(sk) ? : -EPIPE; + if (err == -EPIPE && !(flags & MSG_NOSIGNAL)) + send_sig(SIGPIPE, current, 0); + return err; +} +EXPORT_SYMBOL(sk_stream_error); + +void sk_stream_kill_queues(struct sock *sk) +{ + /* First the read buffer. */ + __skb_queue_purge(&sk->sk_receive_queue); + + /* Next, the error queue. */ + __skb_queue_purge(&sk->sk_error_queue); + + /* Next, the write queue. */ + WARN_ON(!skb_queue_empty(&sk->sk_write_queue)); + + /* Account for returned memory. */ + sk_mem_reclaim(sk); + + WARN_ON(sk->sk_wmem_queued); + WARN_ON(sk->sk_forward_alloc); + + /* It is _impossible_ for the backlog to contain anything + * when we get here. All user references to this socket + * have gone away, only the net layer knows can touch it. + */ +} +EXPORT_SYMBOL(sk_stream_kill_queues); |