blob: a37debfeb1b2bcb3309d93fc5d45b5f82e202d6e [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * SUCS NET3:
3 *
4 * Generic stream handling routines. These are generic for most
5 * protocols. Even IP. Tonight 8-).
6 * This is used because TCP, LLC (others too) layer all have mostly
7 * identical sendmsg() and recvmsg() code.
8 * So we (will) share it here.
9 *
10 * Authors: Arnaldo Carvalho de Melo <acme@conectiva.com.br>
11 * (from old tcp.c code)
Alan Cox113aa832008-10-13 19:01:08 -070012 * Alan Cox <alan@lxorguk.ukuu.org.uk> (Borrowed comments 8-))
Linus Torvalds1da177e2005-04-16 15:20:36 -070013 */
14
15#include <linux/module.h>
16#include <linux/net.h>
17#include <linux/signal.h>
18#include <linux/tcp.h>
19#include <linux/wait.h>
20#include <net/sock.h>
21
22/**
23 * sk_stream_write_space - stream socket write_space callback.
Pavel Pisa4dc3b162005-05-01 08:59:25 -070024 * @sk: socket
Linus Torvalds1da177e2005-04-16 15:20:36 -070025 *
26 * FIXME: write proper description
27 */
28void sk_stream_write_space(struct sock *sk)
29{
30 struct socket *sock = sk->sk_socket;
31
32 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) && sock) {
33 clear_bit(SOCK_NOSPACE, &sock->flags);
34
35 if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
John Dykstra9dc20c52009-05-12 15:34:50 +000036 wake_up_interruptible_poll(sk->sk_sleep, POLLOUT |
37 POLLWRNORM | POLLWRBAND);
Linus Torvalds1da177e2005-04-16 15:20:36 -070038 if (sock->fasync_list && !(sk->sk_shutdown & SEND_SHUTDOWN))
Pavel Emelyanov8d8ad9d2007-11-26 20:10:50 +080039 sock_wake_async(sock, SOCK_WAKE_SPACE, POLL_OUT);
Linus Torvalds1da177e2005-04-16 15:20:36 -070040 }
41}
42
43EXPORT_SYMBOL(sk_stream_write_space);
44
45/**
46 * sk_stream_wait_connect - Wait for a socket to get into the connected state
Pavel Pisa4dc3b162005-05-01 08:59:25 -070047 * @sk: sock to wait on
48 * @timeo_p: for how long to wait
Linus Torvalds1da177e2005-04-16 15:20:36 -070049 *
50 * Must be called with the socket locked.
51 */
52int sk_stream_wait_connect(struct sock *sk, long *timeo_p)
53{
54 struct task_struct *tsk = current;
55 DEFINE_WAIT(wait);
Herbert Xu6151b312005-11-04 09:56:56 +110056 int done;
Linus Torvalds1da177e2005-04-16 15:20:36 -070057
Herbert Xu6151b312005-11-04 09:56:56 +110058 do {
Benjamin LaHaisec1cbe4b2005-12-13 23:22:19 -080059 int err = sock_error(sk);
60 if (err)
61 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -070062 if ((1 << sk->sk_state) & ~(TCPF_SYN_SENT | TCPF_SYN_RECV))
63 return -EPIPE;
64 if (!*timeo_p)
65 return -EAGAIN;
66 if (signal_pending(tsk))
67 return sock_intr_errno(*timeo_p);
68
69 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
70 sk->sk_write_pending++;
Herbert Xu6151b312005-11-04 09:56:56 +110071 done = sk_wait_event(sk, timeo_p,
Benjamin LaHaisec1cbe4b2005-12-13 23:22:19 -080072 !sk->sk_err &&
YOSHIFUJI Hideaki4ec93ed2007-02-09 23:24:36 +090073 !((1 << sk->sk_state) &
Herbert Xu6151b312005-11-04 09:56:56 +110074 ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)));
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 finish_wait(sk->sk_sleep, &wait);
76 sk->sk_write_pending--;
Herbert Xu6151b312005-11-04 09:56:56 +110077 } while (!done);
Linus Torvalds1da177e2005-04-16 15:20:36 -070078 return 0;
79}
80
81EXPORT_SYMBOL(sk_stream_wait_connect);
82
83/**
84 * sk_stream_closing - Return 1 if we still have things to send in our buffers.
Pavel Pisa4dc3b162005-05-01 08:59:25 -070085 * @sk: socket to verify
Linus Torvalds1da177e2005-04-16 15:20:36 -070086 */
87static inline int sk_stream_closing(struct sock *sk)
88{
89 return (1 << sk->sk_state) &
90 (TCPF_FIN_WAIT1 | TCPF_CLOSING | TCPF_LAST_ACK);
91}
92
93void sk_stream_wait_close(struct sock *sk, long timeout)
94{
95 if (timeout) {
96 DEFINE_WAIT(wait);
97
98 do {
99 prepare_to_wait(sk->sk_sleep, &wait,
100 TASK_INTERRUPTIBLE);
101 if (sk_wait_event(sk, &timeout, !sk_stream_closing(sk)))
102 break;
103 } while (!signal_pending(current) && timeout);
104
105 finish_wait(sk->sk_sleep, &wait);
106 }
107}
108
109EXPORT_SYMBOL(sk_stream_wait_close);
110
111/**
112 * sk_stream_wait_memory - Wait for more memory for a socket
Pavel Pisa4dc3b162005-05-01 08:59:25 -0700113 * @sk: socket to wait for memory
114 * @timeo_p: for how long
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115 */
116int sk_stream_wait_memory(struct sock *sk, long *timeo_p)
117{
118 int err = 0;
119 long vm_wait = 0;
120 long current_timeo = *timeo_p;
121 DEFINE_WAIT(wait);
122
123 if (sk_stream_memory_free(sk))
124 current_timeo = vm_wait = (net_random() % (HZ / 5)) + 2;
125
126 while (1) {
127 set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
128
129 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
130
131 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
132 goto do_error;
133 if (!*timeo_p)
134 goto do_nonblock;
135 if (signal_pending(current))
136 goto do_interrupted;
137 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
138 if (sk_stream_memory_free(sk) && !vm_wait)
139 break;
140
141 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
142 sk->sk_write_pending++;
YOSHIFUJI Hideaki4ec93ed2007-02-09 23:24:36 +0900143 sk_wait_event(sk, &current_timeo, !sk->sk_err &&
Benjamin LaHaisec1cbe4b2005-12-13 23:22:19 -0800144 !(sk->sk_shutdown & SEND_SHUTDOWN) &&
145 sk_stream_memory_free(sk) &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 vm_wait);
147 sk->sk_write_pending--;
148
149 if (vm_wait) {
150 vm_wait -= current_timeo;
151 current_timeo = *timeo_p;
152 if (current_timeo != MAX_SCHEDULE_TIMEOUT &&
153 (current_timeo -= vm_wait) < 0)
154 current_timeo = 0;
155 vm_wait = 0;
156 }
157 *timeo_p = current_timeo;
158 }
159out:
160 finish_wait(sk->sk_sleep, &wait);
161 return err;
162
163do_error:
164 err = -EPIPE;
165 goto out;
166do_nonblock:
167 err = -EAGAIN;
168 goto out;
169do_interrupted:
170 err = sock_intr_errno(*timeo_p);
171 goto out;
172}
173
174EXPORT_SYMBOL(sk_stream_wait_memory);
175
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176int sk_stream_error(struct sock *sk, int flags, int err)
177{
178 if (err == -EPIPE)
179 err = sock_error(sk) ? : -EPIPE;
180 if (err == -EPIPE && !(flags & MSG_NOSIGNAL))
181 send_sig(SIGPIPE, current, 0);
182 return err;
183}
184
185EXPORT_SYMBOL(sk_stream_error);
186
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187void sk_stream_kill_queues(struct sock *sk)
188{
189 /* First the read buffer. */
190 __skb_queue_purge(&sk->sk_receive_queue);
191
192 /* Next, the error queue. */
193 __skb_queue_purge(&sk->sk_error_queue);
194
195 /* Next, the write queue. */
Ilpo Järvinen547b7922008-07-25 21:43:18 -0700196 WARN_ON(!skb_queue_empty(&sk->sk_write_queue));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197
198 /* Account for returned memory. */
Hideo Aoki3ab224b2007-12-31 00:11:19 -0800199 sk_mem_reclaim(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200
Ilpo Järvinen547b7922008-07-25 21:43:18 -0700201 WARN_ON(sk->sk_wmem_queued);
202 WARN_ON(sk->sk_forward_alloc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203
204 /* It is _impossible_ for the backlog to contain anything
205 * when we get here. All user references to this socket
206 * have gone away, only the net layer knows can touch it.
207 */
208}
209
210EXPORT_SYMBOL(sk_stream_kill_queues);