Move signal.{c,h} to signals.{c.h} so we can work better in the NetBSD source tree.

1 files changed, 163 insertions, 0 deletions

diff --git a/signals.c b/signals.c
new file mode 100644
index 00000000..9f0bd793
--- /dev/null
+++ b/signals.c
@@ -0,0 +1,163 @@
+/* 
+ * dhcpcd - DHCP client daemon
+ * Copyright 2006-2008 Roy Marples <roy@marples.name>
+ * All rights reserved
+
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/types.h>
+#include <sys/socket.h>
+
+#include <errno.h>
+#include <poll.h>
+#include <signal.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "common.h"
+#include "signals.h"
+
+static int signal_pipe[2];
+static int signals[5];
+
+static const int handle_sigs[] = {
+	SIGHUP,
+	SIGALRM,
+	SIGTERM,
+	SIGINT
+};
+
+static void
+signal_handler(int sig)
+{
+	unsigned int i = 0;
+	int serrno = errno;
+
+	/* Add a signal to our stack */
+	while (signals[i])
+		i++;
+	if (i <= sizeof(signals) / sizeof(signals[0]))
+		signals[i] = sig;
+
+	write(signal_pipe[1], &sig, sizeof(sig));
+
+	/* Restore errno */
+	errno = serrno;
+}
+
+int
+signal_fd(void)
+{
+	return (signal_pipe[0]);
+}
+
+/* Check if we have a signal or not */
+int
+signal_exists(const struct pollfd *fd)
+{
+	if (signals[0] || (fd && fd->revents & POLLIN))
+		return 0;
+	return -1;
+}
+
+/* Read a signal from the signal pipe. Returns 0 if there is
+ * no signal, -1 on error (and sets errno appropriately), and
+ * your signal on success */
+int
+signal_read(struct pollfd *fd)
+{
+	int sig = -1;
+	unsigned int i = 0;
+	char buf[16];
+	size_t bytes;
+
+	/* Pop a signal off the our stack */
+	if (signals[0]) {
+		sig = signals[0];
+		while (i < (sizeof(signals) / sizeof(signals[0])) - 1) {
+			signals[i] = signals[i + 1];
+			if (!signals[++i])
+				break;
+		}
+	}
+
+	if (fd && fd->revents & POLLIN) {
+		memset(buf, 0, sizeof(buf));
+		bytes = read(signal_pipe[0], buf, sizeof(buf));
+
+		if (bytes >= sizeof(sig))
+			memcpy(&sig, buf, sizeof(sig));
+
+		/* We need to clear us from rset if nothing left in the buffer
+		 * in case we are called many times */
+		if (bytes == sizeof(sig))
+			fd->revents = 0;
+	}
+
+	return sig;
+}
+
+/* Call this before doing anything else. Sets up the socket pair
+ * and installs the signal handler */
+int
+signal_init(void)
+{
+	if (pipe(signal_pipe) == -1)
+		return -1;
+
+	/* Stop any scripts from inheriting us */
+	close_on_exec(signal_pipe[0]);
+	close_on_exec(signal_pipe[1]);
+
+	memset(signals, 0, sizeof(signals));
+	return 0;
+}
+
+static int
+_signal_setup(void (*func)(int))
+{
+	unsigned int i;
+	struct sigaction sa;
+
+	memset(&sa, 0, sizeof(sa));
+	sa.sa_handler = func;
+	sigemptyset(&sa.sa_mask);
+
+	for (i = 0; i < sizeof(handle_sigs) / sizeof(handle_sigs[0]); i++)
+		if (sigaction(handle_sigs[i], &sa, NULL) == -1)
+			return -1;
+
+	return 0;
+}
+
+int
+signal_setup(void)
+{
+	return _signal_setup(signal_handler);
+}
+
+int
+signal_reset(void)
+{
+	return _signal_setup(SIG_DFL);
+}