From: Roy Marples <roy@marples.name>
Date: Wed, 7 Nov 2007 10:15:14 +0000 (+0000)
Subject: Clear the signal_pipe fd from the fdset when all signals have
X-Git-Tag: v3.2.3~168
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=de8a9d9887e862c9fefc9b6ff3520c572a57b924;p=thirdparty%2Fdhcpcd.git

Clear the signal_pipe fd from the fdset when all signals have
been read.
---

diff --git a/ChangeLog b/ChangeLog
index b933aff2..1c092e24 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,5 @@
+Clear the signal_pipe fd from the fdset when all signals have
+been read.
 Don't release a link local address.
 Use sysconf to detect if we have a working monotonic clock.
 Only request NTP, NIS, etc if we have compiled that feature in.
diff --git a/arp.c b/arp.c
index 72574d02..e42781cc 100644
--- a/arp.c
+++ b/arp.c
@@ -143,7 +143,7 @@ int arp_claim (interface_t *iface, struct in_addr address)
 			maxfd = signal_fd_set (&rset, iface->fd);
 			if ((s = select (maxfd + 1, &rset, NULL, NULL, &tv)) == -1) {
 				if (errno == EINTR) {
-					if (signal_read (NULL) == -1) {
+					if (signal_exists (NULL) == -1) {
 						errno = 0;
 						continue;
 					} else
diff --git a/client.c b/client.c
index fededbcc..4c3c7409 100644
--- a/client.c
+++ b/client.c
@@ -432,7 +432,7 @@ int dhcp_run (const options_t *options, int *pidfd)
 			retval = 0;
 
 		/* We should always handle our signals first */
-		if ((sig = (signal_read (NULL))) != -1)
+		if ((sig = (signal_read (&rset))) != -1)
 		{
 			switch (sig) {
 				case SIGINT:
@@ -446,7 +446,6 @@ int dhcp_run (const options_t *options, int *pidfd)
 					goto eexit;
 
 				case SIGALRM:
-
 					logger (LOG_INFO, "received SIGALRM, renewing lease");
 					switch (state) {
 						case STATE_BOUND:
diff --git a/signals.c b/signals.c
index 214a6247..bb36cf6c 100644
--- a/signals.c
+++ b/signals.c
@@ -84,22 +84,39 @@ int signal_fd_set (fd_set *rfds, int extra_fd)
 	return signal_pipe[0] > extra_fd ? signal_pipe[0] : extra_fd;
 }
 
+/* Check if we have a signal or not */
+int signal_exists (const fd_set *rfds)
+{
+	if (signal_signal || (rfds && FD_ISSET (signal_pipe[0], rfds)))
+		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 (const fd_set *rfds)
+int signal_read (fd_set *rfds)
 {
-	int sig;
+	int sig = -1;
+
+	if (signal_signal) {
+		sig = signal_signal;
+		signal_signal = 0;
+	}
+
+	if (rfds && FD_ISSET (signal_pipe[0], rfds)) {
+		int buflen = sizeof (sig) * 2;
+		char buf[buflen];
+		size_t bytes;
 
-	if (signal_signal)
-		return signal_signal;
+		memset (buf, 0, buflen);
+		bytes = read (signal_pipe[0], buf, buflen);
 
-	if (! rfds || ! FD_ISSET (signal_pipe[0], rfds))
-		return -1;
-	
-	if (read (signal_pipe[0], &sig, sizeof (sig)) == -1)
-		return -1;
+		/* We need to clear us from rfds if nothing left in the buffer
+		 * in case we are called many times */
+		if (bytes == sizeof (sig))
+			FD_CLR (signal_pipe[0], rfds);
+	}
 
 	return sig;
 }
-
diff --git a/signals.h b/signals.h
index 1accb6cd..b043dbf9 100644
--- a/signals.h
+++ b/signals.h
@@ -22,6 +22,7 @@
 
 void signal_setup (void);
 int signal_fd_set (fd_set *rfds, int extra_fd);
-int signal_read (const fd_set *rfds);
+int signal_exists (const fd_set *rfds);
+int signal_read (fd_set *rfds);
 
 #endif