--- /dev/null
+/*
+ * 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_is_writeable(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 = (prandom_u32() % (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);
Code Review / kvmfornfv.git / blobdiff