1 files changed, 146 insertions, 0 deletions
diff --git a/lib/util/signal.c b/lib/util/signal.c
new file mode 100644
index 0000000..3fc63b2
--- /dev/null
+++ b/lib/util/signal.c
@@ -0,0 +1,146 @@
+/* 
+   Unix SMB/CIFS implementation.
+   signal handling functions
+
+   Copyright (C) Andrew Tridgell 1998
+   
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+   
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "replace.h"
+#include "system/wait.h"
+#include "debug.h"
+#include "lib/util/signal.h" /* Avoid /usr/include/signal.h */
+
+/**
+ * @file
+ * @brief Signal handling
+ */
+
+/****************************************************************************
+ Catch child exits and reap the child zombie status.
+****************************************************************************/
+
+static void sig_cld(int signum)
+{
+	while (waitpid((pid_t)-1,(int *)NULL, WNOHANG) > 0)
+		;
+
+	/*
+	 * Turns out it's *really* important not to
+	 * restore the signal handler here if we have real POSIX
+	 * signal handling. If we do, then we get the signal re-delivered
+	 * immediately - hey presto - instant loop ! JRA.
+	 */
+
+#if !defined(HAVE_SIGACTION)
+	CatchSignal(SIGCLD, sig_cld);
+#endif
+}
+
+/****************************************************************************
+catch child exits - leave status;
+****************************************************************************/
+
+static void sig_cld_leave_status(int signum)
+{
+	/*
+	 * Turns out it's *really* important not to
+	 * restore the signal handler here if we have real POSIX
+	 * signal handling. If we do, then we get the signal re-delivered
+	 * immediately - hey presto - instant loop ! JRA.
+	 */
+
+#if !defined(HAVE_SIGACTION)
+	CatchSignal(SIGCLD, sig_cld_leave_status);
+#endif
+}
+
+/**
+ Block sigs.
+**/
+
+void BlockSignals(bool block, int signum)
+{
+#ifdef HAVE_SIGPROCMASK
+	sigset_t set;
+	sigemptyset(&set);
+	sigaddset(&set,signum);
+	sigprocmask(block?SIG_BLOCK:SIG_UNBLOCK,&set,NULL);
+#elif defined(HAVE_SIGBLOCK)
+	if (block) {
+		sigblock(sigmask(signum));
+	} else {
+		sigsetmask(siggetmask() & ~sigmask(signum));
+	}
+#else
+	/* yikes! This platform can't block signals? */
+	static int done;
+	if (!done) {
+		DEBUG(0,("WARNING: No signal blocking available\n"));
+		done=1;
+	}
+#endif
+}
+
+/**
+ Catch a signal. This should implement the following semantics:
+
+ 1) The handler remains installed after being called.
+ 2) The signal should be blocked during handler execution.
+**/
+
+void (*CatchSignal(int signum,void (*handler)(int )))(int)
+{
+#ifdef HAVE_SIGACTION
+	struct sigaction act;
+	struct sigaction oldact;
+
+	ZERO_STRUCT(act);
+
+	act.sa_handler = handler;
+#ifdef SA_RESTART
+	/*
+	 * We *want* SIGALRM to interrupt a system call.
+	 */
+	if(signum != SIGALRM)
+		act.sa_flags = SA_RESTART;
+#endif
+	sigemptyset(&act.sa_mask);
+	sigaddset(&act.sa_mask,signum);
+	sigaction(signum,&act,&oldact);
+	return oldact.sa_handler;
+#else /* !HAVE_SIGACTION */
+	/* FIXME: need to handle sigvec and systems with broken signal() */
+	return signal(signum, handler);
+#endif
+}
+
+/**
+ Ignore SIGCLD via whatever means is necessary for this OS.
+**/
+
+void (*CatchChild(void))(int)
+{
+	return CatchSignal(SIGCLD, sig_cld);
+}
+
+/**
+ Catch SIGCLD but leave the child around so it's status can be reaped.
+**/
+
+void (*CatchChildLeaveStatus(void))(int)
+{
+	return CatchSignal(SIGCLD, sig_cld_leave_status);
+}