Fix wpa_supplicant.conf permissions (0660)

Change-Id: I62e6711f706af88d4447f2885f7a0ce3f30a8a2e
Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>

wifi/wifi.c

@@ -239,7 +239,7 @@ int ensure_config_file_exists()
         return -1;
     }
 
-    destfd = open(SUPP_CONFIG_FILE, O_CREAT|O_WRONLY, 0660);
+    destfd = open(SUPP_CONFIG_FILE, O_CREAT|O_RDWR, 0660);
     if (destfd < 0) {
         close(srcfd);
         LOGE("Cannot create \"%s\": %s", SUPP_CONFIG_FILE, strerror(errno));
@@ -260,6 +260,14 @@ int ensure_config_file_exists()
     close(destfd);
     close(srcfd);
 
+    /* chmod is needed because open() didn't set permisions properly */
+    if (chmod(SUPP_CONFIG_FILE, 0660) < 0) {
+        LOGE("Error changing permissions of %s to 0660: %s",
+             SUPP_CONFIG_FILE, strerror(errno));
+        unlink(SUPP_CONFIG_FILE);
+        return -1;
+    }
+
     if (chown(SUPP_CONFIG_FILE, AID_SYSTEM, AID_WIFI) < 0) {
         LOGE("Error changing group ownership of %s to %d: %s",
              SUPP_CONFIG_FILE, AID_WIFI, strerror(errno));