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1 #ifndef HEADER_CURL_SIGPIPE_H
2 #define HEADER_CURL_SIGPIPE_H
3 /***************************************************************************
4  *                                  _   _ ____  _
5  *  Project                     ___| | | |  _ \| |
6  *                             / __| | | | |_) | |
7  *                            | (__| |_| |  _ <| |___
8  *                             \___|\___/|_| \_\_____|
9  *
10  * Copyright (C) 1998 - 2021, 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  ***************************************************************************/
24 #include "curl_setup.h"
25 
26 #if defined(HAVE_SIGNAL_H) && defined(HAVE_SIGACTION) &&        \
27   (defined(USE_OPENSSL) || defined(USE_MBEDTLS) || defined(USE_WOLFSSL))
28 #include <signal.h>
29 
30 struct sigpipe_ignore {
31   struct sigaction old_pipe_act;
32   bool no_signal;
33 };
34 
35 #define SIGPIPE_VARIABLE(x) struct sigpipe_ignore x
36 
37 /*
38  * sigpipe_ignore() makes sure we ignore SIGPIPE while running libcurl
39  * internals, and then sigpipe_restore() will restore the situation when we
40  * return from libcurl again.
41  */
sigpipe_ignore(struct Curl_easy * data,struct sigpipe_ignore * ig)42 static void sigpipe_ignore(struct Curl_easy *data,
43                            struct sigpipe_ignore *ig)
44 {
45   /* get a local copy of no_signal because the Curl_easy might not be
46      around when we restore */
47   ig->no_signal = data->set.no_signal;
48   if(!data->set.no_signal) {
49     struct sigaction action;
50     /* first, extract the existing situation */
51     memset(&ig->old_pipe_act, 0, sizeof(struct sigaction));
52     sigaction(SIGPIPE, NULL, &ig->old_pipe_act);
53     action = ig->old_pipe_act;
54     /* ignore this signal */
55     action.sa_handler = SIG_IGN;
56     sigaction(SIGPIPE, &action, NULL);
57   }
58 }
59 
60 /*
61  * sigpipe_restore() puts back the outside world's opinion of signal handler
62  * and SIGPIPE handling. It MUST only be called after a corresponding
63  * sigpipe_ignore() was used.
64  */
sigpipe_restore(struct sigpipe_ignore * ig)65 static void sigpipe_restore(struct sigpipe_ignore *ig)
66 {
67   if(!ig->no_signal)
68     /* restore the outside state */
69     sigaction(SIGPIPE, &ig->old_pipe_act, NULL);
70 }
71 
72 #else
73 /* for systems without sigaction */
74 #define sigpipe_ignore(x,y) Curl_nop_stmt
75 #define sigpipe_restore(x)  Curl_nop_stmt
76 #define SIGPIPE_VARIABLE(x)
77 #endif
78 
79 #endif /* HEADER_CURL_SIGPIPE_H */
80