blob: 4a0ad152c9c4492c35fc3abc6ac21bf4580abb20 [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)
12 * Alan Cox <alan@redhat.com> (Borrowed comments 8-))
13 */
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))
36 wake_up_interruptible(sk->sk_sleep);
37 if (sock->fasync_list && !(sk->sk_shutdown & SEND_SHUTDOWN))
Pavel Emelyanov8d8ad9d2007-11-26 20:10:50 +080038 sock_wake_async(sock, SOCK_WAKE_SPACE, POLL_OUT);
Linus Torvalds1da177e2005-04-16 15:20:36 -070039 }
40}
41
42EXPORT_SYMBOL(sk_stream_write_space);
43
44/**
45 * sk_stream_wait_connect - Wait for a socket to get into the connected state
Pavel Pisa4dc3b162005-05-01 08:59:25 -070046 * @sk: sock to wait on
47 * @timeo_p: for how long to wait
Linus Torvalds1da177e2005-04-16 15:20:36 -070048 *
49 * Must be called with the socket locked.
50 */
51int sk_stream_wait_connect(struct sock *sk, long *timeo_p)
52{
53 struct task_struct *tsk = current;
54 DEFINE_WAIT(wait);
Herbert Xu6151b312005-11-04 09:56:56 +110055 int done;
Linus Torvalds1da177e2005-04-16 15:20:36 -070056
Herbert Xu6151b312005-11-04 09:56:56 +110057 do {
Benjamin LaHaisec1cbe4b2005-12-13 23:22:19 -080058 int err = sock_error(sk);
59 if (err)
60 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -070061 if ((1 << sk->sk_state) & ~(TCPF_SYN_SENT | TCPF_SYN_RECV))
62 return -EPIPE;
63 if (!*timeo_p)
64 return -EAGAIN;
65 if (signal_pending(tsk))
66 return sock_intr_errno(*timeo_p);
67
68 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
69 sk->sk_write_pending++;
Herbert Xu6151b312005-11-04 09:56:56 +110070 done = sk_wait_event(sk, timeo_p,
Benjamin LaHaisec1cbe4b2005-12-13 23:22:19 -080071 !sk->sk_err &&
YOSHIFUJI Hideaki4ec93ed2007-02-09 23:24:36 +090072 !((1 << sk->sk_state) &
Herbert Xu6151b312005-11-04 09:56:56 +110073 ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)));
Linus Torvalds1da177e2005-04-16 15:20:36 -070074 finish_wait(sk->sk_sleep, &wait);
75 sk->sk_write_pending--;
Herbert Xu6151b312005-11-04 09:56:56 +110076 } while (!done);
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 return 0;
78}
79
80EXPORT_SYMBOL(sk_stream_wait_connect);
81
82/**
83 * sk_stream_closing - Return 1 if we still have things to send in our buffers.
Pavel Pisa4dc3b162005-05-01 08:59:25 -070084 * @sk: socket to verify
Linus Torvalds1da177e2005-04-16 15:20:36 -070085 */
86static inline int sk_stream_closing(struct sock *sk)
87{
88 return (1 << sk->sk_state) &
89 (TCPF_FIN_WAIT1 | TCPF_CLOSING | TCPF_LAST_ACK);
90}
91
92void sk_stream_wait_close(struct sock *sk, long timeout)
93{
94 if (timeout) {
95 DEFINE_WAIT(wait);
96
97 do {
98 prepare_to_wait(sk->sk_sleep, &wait,
99 TASK_INTERRUPTIBLE);
100 if (sk_wait_event(sk, &timeout, !sk_stream_closing(sk)))
101 break;
102 } while (!signal_pending(current) && timeout);
103
104 finish_wait(sk->sk_sleep, &wait);
105 }
106}
107
108EXPORT_SYMBOL(sk_stream_wait_close);
109
110/**
111 * sk_stream_wait_memory - Wait for more memory for a socket
Pavel Pisa4dc3b162005-05-01 08:59:25 -0700112 * @sk: socket to wait for memory
113 * @timeo_p: for how long
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 */
115int sk_stream_wait_memory(struct sock *sk, long *timeo_p)
116{
117 int err = 0;
118 long vm_wait = 0;
119 long current_timeo = *timeo_p;
120 DEFINE_WAIT(wait);
121
122 if (sk_stream_memory_free(sk))
123 current_timeo = vm_wait = (net_random() % (HZ / 5)) + 2;
124
125 while (1) {
126 set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
127
128 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
129
130 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
131 goto do_error;
132 if (!*timeo_p)
133 goto do_nonblock;
134 if (signal_pending(current))
135 goto do_interrupted;
136 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
137 if (sk_stream_memory_free(sk) && !vm_wait)
138 break;
139
140 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
141 sk->sk_write_pending++;
YOSHIFUJI Hideaki4ec93ed2007-02-09 23:24:36 +0900142 sk_wait_event(sk, &current_timeo, !sk->sk_err &&
Benjamin LaHaisec1cbe4b2005-12-13 23:22:19 -0800143 !(sk->sk_shutdown & SEND_SHUTDOWN) &&
144 sk_stream_memory_free(sk) &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 vm_wait);
146 sk->sk_write_pending--;
147
148 if (vm_wait) {
149 vm_wait -= current_timeo;
150 current_timeo = *timeo_p;
151 if (current_timeo != MAX_SCHEDULE_TIMEOUT &&
152 (current_timeo -= vm_wait) < 0)
153 current_timeo = 0;
154 vm_wait = 0;
155 }
156 *timeo_p = current_timeo;
157 }
158out:
159 finish_wait(sk->sk_sleep, &wait);
160 return err;
161
162do_error:
163 err = -EPIPE;
164 goto out;
165do_nonblock:
166 err = -EAGAIN;
167 goto out;
168do_interrupted:
169 err = sock_intr_errno(*timeo_p);
170 goto out;
171}
172
173EXPORT_SYMBOL(sk_stream_wait_memory);
174
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175int sk_stream_error(struct sock *sk, int flags, int err)
176{
177 if (err == -EPIPE)
178 err = sock_error(sk) ? : -EPIPE;
179 if (err == -EPIPE && !(flags & MSG_NOSIGNAL))
180 send_sig(SIGPIPE, current, 0);
181 return err;
182}
183
184EXPORT_SYMBOL(sk_stream_error);
185
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186void sk_stream_kill_queues(struct sock *sk)
187{
188 /* First the read buffer. */
189 __skb_queue_purge(&sk->sk_receive_queue);
190
191 /* Next, the error queue. */
192 __skb_queue_purge(&sk->sk_error_queue);
193
194 /* Next, the write queue. */
195 BUG_TRAP(skb_queue_empty(&sk->sk_write_queue));
196
197 /* Account for returned memory. */
Hideo Aoki3ab224b2007-12-31 00:11:19 -0800198 sk_mem_reclaim(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199
200 BUG_TRAP(!sk->sk_wmem_queued);
201 BUG_TRAP(!sk->sk_forward_alloc);
202
203 /* It is _impossible_ for the backlog to contain anything
204 * when we get here. All user references to this socket
205 * have gone away, only the net layer knows can touch it.
206 */
207}
208
209EXPORT_SYMBOL(sk_stream_kill_queues);