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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * SUCS NET3: | |
4 | * | |
5 | * Generic stream handling routines. These are generic for most | |
6 | * protocols. Even IP. Tonight 8-). | |
7 | * This is used because TCP, LLC (others too) layer all have mostly | |
8 | * identical sendmsg() and recvmsg() code. | |
9 | * So we (will) share it here. | |
10 | * | |
11 | * Authors: Arnaldo Carvalho de Melo <acme@conectiva.com.br> | |
12 | * (from old tcp.c code) | |
113aa838 | 13 | * Alan Cox <alan@lxorguk.ukuu.org.uk> (Borrowed comments 8-)) |
1da177e4 LT |
14 | */ |
15 | ||
16 | #include <linux/module.h> | |
3f07c014 | 17 | #include <linux/sched/signal.h> |
1da177e4 LT |
18 | #include <linux/net.h> |
19 | #include <linux/signal.h> | |
20 | #include <linux/tcp.h> | |
21 | #include <linux/wait.h> | |
22 | #include <net/sock.h> | |
23 | ||
24 | /** | |
25 | * sk_stream_write_space - stream socket write_space callback. | |
4dc3b16b | 26 | * @sk: socket |
1da177e4 LT |
27 | * |
28 | * FIXME: write proper description | |
29 | */ | |
30 | void sk_stream_write_space(struct sock *sk) | |
31 | { | |
32 | struct socket *sock = sk->sk_socket; | |
43815482 | 33 | struct socket_wq *wq; |
1da177e4 | 34 | |
a74f0fa0 | 35 | if (__sk_stream_is_writeable(sk, 1) && sock) { |
1da177e4 LT |
36 | clear_bit(SOCK_NOSPACE, &sock->flags); |
37 | ||
43815482 ED |
38 | rcu_read_lock(); |
39 | wq = rcu_dereference(sk->sk_wq); | |
1ce0bf50 | 40 | if (skwq_has_sleeper(wq)) |
a9a08845 LT |
41 | wake_up_interruptible_poll(&wq->wait, EPOLLOUT | |
42 | EPOLLWRNORM | EPOLLWRBAND); | |
43815482 | 43 | if (wq && wq->fasync_list && !(sk->sk_shutdown & SEND_SHUTDOWN)) |
ceb5d58b | 44 | sock_wake_async(wq, SOCK_WAKE_SPACE, POLL_OUT); |
43815482 | 45 | rcu_read_unlock(); |
1da177e4 LT |
46 | } |
47 | } | |
1da177e4 LT |
48 | |
49 | /** | |
50 | * sk_stream_wait_connect - Wait for a socket to get into the connected state | |
4dc3b16b PP |
51 | * @sk: sock to wait on |
52 | * @timeo_p: for how long to wait | |
1da177e4 LT |
53 | * |
54 | * Must be called with the socket locked. | |
55 | */ | |
56 | int sk_stream_wait_connect(struct sock *sk, long *timeo_p) | |
57 | { | |
d9dc8b0f | 58 | DEFINE_WAIT_FUNC(wait, woken_wake_function); |
1da177e4 | 59 | struct task_struct *tsk = current; |
6151b31c | 60 | int done; |
1da177e4 | 61 | |
6151b31c | 62 | do { |
c1cbe4b7 BL |
63 | int err = sock_error(sk); |
64 | if (err) | |
65 | return err; | |
1da177e4 LT |
66 | if ((1 << sk->sk_state) & ~(TCPF_SYN_SENT | TCPF_SYN_RECV)) |
67 | return -EPIPE; | |
68 | if (!*timeo_p) | |
69 | return -EAGAIN; | |
70 | if (signal_pending(tsk)) | |
71 | return sock_intr_errno(*timeo_p); | |
72 | ||
d9dc8b0f | 73 | add_wait_queue(sk_sleep(sk), &wait); |
1da177e4 | 74 | sk->sk_write_pending++; |
6151b31c | 75 | done = sk_wait_event(sk, timeo_p, |
c1cbe4b7 | 76 | !sk->sk_err && |
4ec93edb | 77 | !((1 << sk->sk_state) & |
d9dc8b0f WC |
78 | ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)), &wait); |
79 | remove_wait_queue(sk_sleep(sk), &wait); | |
1da177e4 | 80 | sk->sk_write_pending--; |
6151b31c | 81 | } while (!done); |
1da177e4 LT |
82 | return 0; |
83 | } | |
1da177e4 LT |
84 | EXPORT_SYMBOL(sk_stream_wait_connect); |
85 | ||
86 | /** | |
87 | * sk_stream_closing - Return 1 if we still have things to send in our buffers. | |
4dc3b16b | 88 | * @sk: socket to verify |
1da177e4 LT |
89 | */ |
90 | static inline int sk_stream_closing(struct sock *sk) | |
91 | { | |
92 | return (1 << sk->sk_state) & | |
93 | (TCPF_FIN_WAIT1 | TCPF_CLOSING | TCPF_LAST_ACK); | |
94 | } | |
95 | ||
96 | void sk_stream_wait_close(struct sock *sk, long timeout) | |
97 | { | |
98 | if (timeout) { | |
d9dc8b0f WC |
99 | DEFINE_WAIT_FUNC(wait, woken_wake_function); |
100 | ||
101 | add_wait_queue(sk_sleep(sk), &wait); | |
1da177e4 LT |
102 | |
103 | do { | |
d9dc8b0f | 104 | if (sk_wait_event(sk, &timeout, !sk_stream_closing(sk), &wait)) |
1da177e4 LT |
105 | break; |
106 | } while (!signal_pending(current) && timeout); | |
107 | ||
d9dc8b0f | 108 | remove_wait_queue(sk_sleep(sk), &wait); |
1da177e4 LT |
109 | } |
110 | } | |
1da177e4 LT |
111 | EXPORT_SYMBOL(sk_stream_wait_close); |
112 | ||
113 | /** | |
114 | * sk_stream_wait_memory - Wait for more memory for a socket | |
4dc3b16b PP |
115 | * @sk: socket to wait for memory |
116 | * @timeo_p: for how long | |
1da177e4 LT |
117 | */ |
118 | int sk_stream_wait_memory(struct sock *sk, long *timeo_p) | |
119 | { | |
120 | int err = 0; | |
121 | long vm_wait = 0; | |
122 | long current_timeo = *timeo_p; | |
790ba456 | 123 | bool noblock = (*timeo_p ? false : true); |
d9dc8b0f | 124 | DEFINE_WAIT_FUNC(wait, woken_wake_function); |
1da177e4 LT |
125 | |
126 | if (sk_stream_memory_free(sk)) | |
63862b5b | 127 | current_timeo = vm_wait = (prandom_u32() % (HZ / 5)) + 2; |
1da177e4 | 128 | |
d9dc8b0f WC |
129 | add_wait_queue(sk_sleep(sk), &wait); |
130 | ||
1da177e4 | 131 | while (1) { |
9cd3e072 | 132 | sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk); |
1da177e4 | 133 | |
1da177e4 LT |
134 | if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) |
135 | goto do_error; | |
790ba456 JB |
136 | if (!*timeo_p) { |
137 | if (noblock) | |
138 | set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); | |
1da177e4 | 139 | goto do_nonblock; |
790ba456 | 140 | } |
1da177e4 LT |
141 | if (signal_pending(current)) |
142 | goto do_interrupted; | |
9cd3e072 | 143 | sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); |
1da177e4 LT |
144 | if (sk_stream_memory_free(sk) && !vm_wait) |
145 | break; | |
146 | ||
147 | set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); | |
148 | sk->sk_write_pending++; | |
482964e5 NT |
149 | sk_wait_event(sk, ¤t_timeo, sk->sk_err || |
150 | (sk->sk_shutdown & SEND_SHUTDOWN) || | |
151 | (sk_stream_memory_free(sk) && | |
d9dc8b0f | 152 | !vm_wait), &wait); |
1da177e4 LT |
153 | sk->sk_write_pending--; |
154 | ||
155 | if (vm_wait) { | |
156 | vm_wait -= current_timeo; | |
157 | current_timeo = *timeo_p; | |
158 | if (current_timeo != MAX_SCHEDULE_TIMEOUT && | |
159 | (current_timeo -= vm_wait) < 0) | |
160 | current_timeo = 0; | |
161 | vm_wait = 0; | |
162 | } | |
163 | *timeo_p = current_timeo; | |
164 | } | |
165 | out: | |
d9dc8b0f | 166 | remove_wait_queue(sk_sleep(sk), &wait); |
1da177e4 LT |
167 | return err; |
168 | ||
169 | do_error: | |
170 | err = -EPIPE; | |
171 | goto out; | |
172 | do_nonblock: | |
173 | err = -EAGAIN; | |
174 | goto out; | |
175 | do_interrupted: | |
176 | err = sock_intr_errno(*timeo_p); | |
177 | goto out; | |
178 | } | |
1da177e4 LT |
179 | EXPORT_SYMBOL(sk_stream_wait_memory); |
180 | ||
1da177e4 LT |
181 | int sk_stream_error(struct sock *sk, int flags, int err) |
182 | { | |
183 | if (err == -EPIPE) | |
184 | err = sock_error(sk) ? : -EPIPE; | |
185 | if (err == -EPIPE && !(flags & MSG_NOSIGNAL)) | |
186 | send_sig(SIGPIPE, current, 0); | |
187 | return err; | |
188 | } | |
1da177e4 LT |
189 | EXPORT_SYMBOL(sk_stream_error); |
190 | ||
1da177e4 LT |
191 | void sk_stream_kill_queues(struct sock *sk) |
192 | { | |
193 | /* First the read buffer. */ | |
194 | __skb_queue_purge(&sk->sk_receive_queue); | |
195 | ||
196 | /* Next, the error queue. */ | |
197 | __skb_queue_purge(&sk->sk_error_queue); | |
198 | ||
199 | /* Next, the write queue. */ | |
547b792c | 200 | WARN_ON(!skb_queue_empty(&sk->sk_write_queue)); |
1da177e4 LT |
201 | |
202 | /* Account for returned memory. */ | |
3ab224be | 203 | sk_mem_reclaim(sk); |
1da177e4 | 204 | |
547b792c IJ |
205 | WARN_ON(sk->sk_wmem_queued); |
206 | WARN_ON(sk->sk_forward_alloc); | |
1da177e4 LT |
207 | |
208 | /* It is _impossible_ for the backlog to contain anything | |
209 | * when we get here. All user references to this socket | |
210 | * have gone away, only the net layer knows can touch it. | |
211 | */ | |
212 | } | |
1da177e4 | 213 | EXPORT_SYMBOL(sk_stream_kill_queues); |