sigpipe: factor out sigpipe_reset from easy.c

Commit 7d80ed64e43515 introduced some helpers to handle
sigpipe in easy.c. However, that fix was incomplete, and we
need to add more callers in other files. The first step is
making the helpers globally accessible.

Since the functions are small and should generally end up
inlined anyway, we simply define them in the header as
static functions.

Signed-off-by: Jeff King <peff@peff.net>

1 files changed, 78 insertions, 0 deletions

diff --git a/lib/sigpipe.h b/lib/sigpipe.h
new file mode 100644
index 000000000..e8d2acd6e
--- /dev/null
+++ b/lib/sigpipe.h
@@ -0,0 +1,78 @@
+#ifndef HEADER_CURL_SIGPIPE_H
+#define HEADER_CURL_SIGPIPE_H
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2013, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at http://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+#include "curl_setup.h"
+
+#if defined(HAVE_SIGNAL_H) && defined(HAVE_SIGACTION) && defined(USE_OPENSSL)
+#include <signal.h>
+
+struct sigpipe_ignore {
+  struct sigaction old_pipe_act;
+  bool no_signal;
+};
+
+#define SIGPIPE_VARIABLE(x) struct sigpipe_ignore x
+
+/*
+ * sigpipe_ignore() makes sure we ignore SIGPIPE while running libcurl
+ * internals, and then sigpipe_restore() will restore the situation when we
+ * return from libcurl again.
+ */
+static void sigpipe_ignore(struct SessionHandle *data,
+                           struct sigpipe_ignore *ig)
+{
+  /* get a local copy of no_signal because the SessionHandle might not be
+     around when we restore */
+  ig->no_signal = data->set.no_signal;
+  if(!data->set.no_signal) {
+    struct sigaction action;
+    /* first, extract the existing situation */
+    memset(&ig->old_pipe_act, 0, sizeof(struct sigaction));
+    sigaction(SIGPIPE, NULL, &ig->old_pipe_act);
+    action = ig->old_pipe_act;
+    /* ignore this signal */
+    action.sa_handler = SIG_IGN;
+    sigaction(SIGPIPE, &action, NULL);
+  }
+}
+
+/*
+ * sigpipe_restore() puts back the outside world's opinion of signal handler
+ * and SIGPIPE handling. It MUST only be called after a corresponding
+ * sigpipe_ignore() was used.
+ */
+static void sigpipe_restore(struct sigpipe_ignore *ig)
+{
+  if(!ig->no_signal)
+    /* restore the outside state */
+    sigaction(SIGPIPE, &ig->old_pipe_act, NULL);
+}
+
+#else
+/* for systems without sigaction */
+#define sigpipe_ignore(x,y) Curl_nop_stmt
+#define sigpipe_restore(x)  Curl_nop_stmt
+#define SIGPIPE_VARIABLE(x)
+#endif
+
+#endif /* HEADER_CURL_SIGPIPE_H */