src/3rdparty: Add 3rdparty files from Zeek's src/

src/3rdparty/setsignal.c

@@ -0,0 +1,52 @@
+/*
+ * See the file "COPYING" in the main distribution directory for copyright.
+ */
+
+#include "zeek/zeek-config.h"			/* must appear before first ifdef */
+
+#include <sys/types.h>
+
+#ifdef HAVE_MEMORY_H
+#include <memory.h>
+#endif
+#include <signal.h>
+#ifdef HAVE_SIGACTION
+#include <string.h>
+#endif
+
+#include "setsignal.h"
+
+/*
+ * An os independent signal() with BSD semantics, e.g. the signal
+ * catcher is restored following service of the signal.
+ *
+ * When sigset() is available, signal() has SYSV semantics and sigset()
+ * has BSD semantics and call interface. Unfortunately, Linux does not
+ * have sigset() so we use the more complicated sigaction() interface
+ * there.
+ *
+ * Did I mention that signals suck?
+ */
+RETSIGTYPE
+(*setsignal (int sig, RETSIGTYPE (*func)(int)))(int)
+{
+#ifdef HAVE_SIGACTION
+	struct sigaction old, new;
+
+	memset(&new, 0, sizeof(new));
+	new.sa_handler = func;
+#ifdef SA_RESTART
+	new.sa_flags |= SA_RESTART;
+#endif
+	if (sigaction(sig, &new, &old) < 0)
+		return (SIG_ERR);
+	return (old.sa_handler);
+
+#else
+#ifdef HAVE_SIGSET
+	return (sigset(sig, func));
+#else
+	return (signal(sig, func));
+#endif
+#endif
+}