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 
32 struct 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  */
sigpipe_ignore(struct Curl_easy *data, struct sigpipe_ignore *ig)44 static 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  */
sigpipe_restore(struct sigpipe_ignore *ig)66 static 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