xref: /third_party/curl/lib/sigpipe.h (revision 13498266) 
1#ifndef HEADER_CURL_SIGPIPE_H
2#define HEADER_CURL_SIGPIPE_H
3/***************************************************************************
4 *                                  _   _ ____  _
5 *  Project                     ___| | | |  _ \| |
6 *                             / __| | | | |_) | |
7 *                            | (__| |_| |  _ <| |___
8 *                             \___|\___/|_| \_\_____|
9 *
10 * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
11 *
12 * This software is licensed as described in the file COPYING, which
13 * you should have received as part of this distribution. The terms
14 * are also available at https://curl.se/docs/copyright.html.
15 *
16 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
17 * copies of the Software, and permit persons to whom the Software is
18 * furnished to do so, under the terms of the COPYING file.
19 *
20 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
21 * KIND, either express or implied.
22 *
23 * SPDX-License-Identifier: curl
24 *
25 ***************************************************************************/
26#include "curl_setup.h"
27
28#if defined(HAVE_SIGACTION) &&        \
29  (defined(USE_OPENSSL) || defined(USE_MBEDTLS) || defined(USE_WOLFSSL))
30#include <signal.h>
31
32struct sigpipe_ignore {
33  struct sigaction old_pipe_act;
34  bool no_signal;
35};
36
37#define SIGPIPE_VARIABLE(x) struct sigpipe_ignore x
38
39/*
40 * sigpipe_ignore() makes sure we ignore SIGPIPE while running libcurl
41 * internals, and then sigpipe_restore() will restore the situation when we
42 * return from libcurl again.
43 */
44static void sigpipe_ignore(struct Curl_easy *data,
45                           struct sigpipe_ignore *ig)
46{
47  /* get a local copy of no_signal because the Curl_easy might not be
48     around when we restore */
49  ig->no_signal = data->set.no_signal;
50  if(!data->set.no_signal) {
51    struct sigaction action;
52    /* first, extract the existing situation */
53    sigaction(SIGPIPE, NULL, &ig->old_pipe_act);
54    action = ig->old_pipe_act;
55    /* ignore this signal */
56    action.sa_handler = SIG_IGN;
57    sigaction(SIGPIPE, &action, NULL);
58  }
59}
60
61/*
62 * sigpipe_restore() puts back the outside world's opinion of signal handler
63 * and SIGPIPE handling. It MUST only be called after a corresponding
64 * sigpipe_ignore() was used.
65 */
66static void sigpipe_restore(struct sigpipe_ignore *ig)
67{
68  if(!ig->no_signal)
69    /* restore the outside state */
70    sigaction(SIGPIPE, &ig->old_pipe_act, NULL);
71}
72
73#else
74/* for systems without sigaction */
75#define sigpipe_ignore(x,y) Curl_nop_stmt
76#define sigpipe_restore(x)  Curl_nop_stmt
77#define SIGPIPE_VARIABLE(x)
78#endif
79
80#endif /* HEADER_CURL_SIGPIPE_H */
81