From bb9970a9df95837e39d680021b1f73d231e85406 Mon Sep 17 00:00:00 2001

From: Stephen Hemminger <shemminger@vyatta.com>

Date: Tue, 3 May 2011 09:52:43 -0700

Subject: [PATCH 3/3] Check error returns from write to sysfs

Add helper function to check write to sysfs files.

Signed-off-by: Petr Sabata <contyk@redhat.com>

---

 libbridge/libbridge_devif.c |   37 +++++++++++++++++++++++--------------

 1 files changed, 23 insertions(+), 14 deletions(-)

diff --git a/libbridge/libbridge_devif.c b/libbridge/libbridge_devif.c

index aa8bc36..1e83925 100644

--- a/libbridge/libbridge_devif.c

+++ b/libbridge/libbridge_devif.c

@@ -280,25 +280,38 @@ fallback:

 	return old_get_port_info(brname, port, info);

 }

+static int set_sysfs(const char *path, unsigned long value)

+{

+	int fd, ret = 0, cc;

+	char buf[32];

+

+	fd = open(path, O_WRONLY);

+	if (fd < 0)

+		return -1;

+

+	cc = snprintf(buf, sizeof(buf), "%lu\n", value);

+	if (write(fd, buf, cc) < 0)

+		ret = -1;

+	close(fd);

+

+	return ret;

+}

+

 static int br_set(const char *bridge, const char *name,

 		  unsigned long value, unsigned long oldcode)

 {

 	int ret;

 	char path[SYSFS_PATH_MAX];

-	FILE *f;

-	snprintf(path, SYSFS_PATH_MAX, SYSFS_CLASS_NET "%s/%s", bridge, name);

+	snprintf(path, SYSFS_PATH_MAX, SYSFS_CLASS_NET "%s/bridge/%s",

+		 bridge, name);

-	f = fopen(path, "w");

-	if (f) {

-		ret = fprintf(f, "%ld\n", value);

-		fclose(f);

-	} else {

+	if ((ret = set_sysfs(path, value)) < 0) {

 		/* fallback to old ioctl */

 		struct ifreq ifr;

 		unsigned long args[4] = { oldcode, value, 0, 0 };

-		

+

 		strncpy(ifr.ifr_name, bridge, IFNAMSIZ);

 		ifr.ifr_data = (char *) &arg;;

 		ret = ioctl(br_socket_fd, SIOCDEVPRIVATE, &ifr);

@@ -348,14 +361,10 @@ static int port_set(const char *bridge, const char *ifname,

 {

 	int ret;

 	char path[SYSFS_PATH_MAX];

-	FILE *f;

 	snprintf(path, SYSFS_PATH_MAX, SYSFS_CLASS_NET "%s/brport/%s", ifname, name);

-	f = fopen(path, "w");

-	if (f) {

-		ret = fprintf(f, "%ld\n", value);

-		fclose(f);

-	} else {

+

+	if ((ret = set_sysfs(path, value)) < 0) {

 		int index = get_portno(bridge, ifname);

 		if (index < 0)

-- 

1.7.5.2