xenstat: don't leak memory in getBridge

getBridge's method of returning a result was a little confused:
allocating a result buffer but never using it.

Simplify by instead allowing a result buffer to be passed in and
modifying the single usage to match.

Signed-off-by: Matthew Daley <mattd@bugfuzz.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>

diff --git a/tools/xenstat/libxenstat/src/xenstat_linux.c b/tools/xenstat/libxenstat/src/xenstat_linux.c
index 931b24e1548eae24910c2f84ab7e407897b51ba8..24335e133658f5f2a263226fa587a55dcb90b308 100644 (file)
--- a/tools/xenstat/libxenstat/src/xenstat_linux.c
+++ b/tools/xenstat/libxenstat/src/xenstat_linux.c
@@ -64,14 +64,12 @@ static const char PROCNETDEV_HEADER[] =
 
 /* We need to get the name of the bridge interface for use with bonding interfaces */
 /* Use excludeName parameter to avoid adding bridges we don't care about, eg. virbr0 */
-char *getBridge(char *excludeName)
+void getBridge(char *excludeName, char *result, size_t resultLen)
 {
        struct dirent *de;
        DIR *d;
 
-       char tmp[256] = { 0 }, *bridge;
-
-       bridge = (char *)malloc(16 * sizeof(char));
+       char tmp[256] = { 0 };
 
        d = opendir("/sys/class/net");
        while ((de = readdir(d)) != NULL) {
@@ -79,14 +77,14 @@ char *getBridge(char *excludeName)
                        && (strstr(de->d_name, excludeName) == NULL)) {
                                sprintf(tmp, "/sys/class/net/%s/bridge", de->d_name);
 
-                               if (access(tmp, F_OK) == 0)
-                                       bridge = de->d_name;
+                               if (access(tmp, F_OK) == 0) {
+                                       strncpy(result, de->d_name, resultLen - 1);
+                                       result[resultLen - 1] = 0;
+                               }
                }
        }
 
        closedir(d);
-
-       return bridge;
 }
 
 /* parseNetLine provides regular expression based parsing for lines from /proc/net/dev, all the */
@@ -279,7 +277,7 @@ int xenstat_collect_networks(xenstat_node * node)
              SEEK_SET);
 
        /* We get the bridge devices for use with bonding interface to get bonding interface stats */
-       snprintf(devBridge, 16, "%s", getBridge("vir"));
+       getBridge("vir", devBridge, sizeof(devBridge));
        snprintf(devNoBridge, 16, "p%s", devBridge);
 
        while (fgets(line, 512, priv->procnetdev)) {