Fix uninitialized variable & error reporting in LXC veth setup

THe veth setup in LXC had a couple of flaws, first brInit did
not report any error when it failed. Second vethCreate() did
not correctly initialize the variable containing the return
code, so could report failure even when it succeeded.

* src/lxc/lxc_driver.c: Report error when brInit fails
* src/lxc/veth.c: Fix uninitialized variable

diff --git a/src/lxc/lxc_driver.c b/src/lxc/lxc_driver.c
index d5f21b1c3434b1bab25c6277a10378cbe94c879a..3159e1b4db30b0777907f1c223a831d99f5c377b 100644 (file)
--- a/src/lxc/lxc_driver.c
+++ b/src/lxc/lxc_driver.c
@@ -1024,9 +1024,13 @@ static int lxcSetupInterfaces(virConnectPtr conn,
     int rc = -1, i;
     char *bridge = NULL;
     brControl *brctl = NULL;
+    int ret;
 
-    if (brInit(&brctl) != 0)
+    if ((ret = brInit(&brctl)) != 0) {
+        virReportSystemError(ret, "%s",
+                             _("Unable to initialize bridging"));
         return -1;
+    }
 
     for (i = 0 ; i < def->nnets ; i++) {
         char *parentVeth;
@@ -1095,7 +1099,7 @@ static int lxcSetupInterfaces(virConnectPtr conn,
                 goto error_exit;
         }
 
-        if (0 != (rc = brAddInterface(brctl, bridge, parentVeth))) {
+        if ((ret = brAddInterface(brctl, bridge, parentVeth)) != 0) {
             virReportSystemError(rc,
                                  _("Failed to add %s device to %s"),
                                  parentVeth, bridge);

diff --git a/src/lxc/veth.c b/src/lxc/veth.c
index 0fa76cfc747aa2fee14d89aef89b3471318c9a60..26bf4ff88b0447de068cd4b0e90828607da67962 100644 (file)
--- a/src/lxc/veth.c
+++ b/src/lxc/veth.c
@@ -90,33 +90,40 @@ static int getFreeVethName(char **veth, int startDev)
  */
 int vethCreate(char** veth1, char** veth2)
 {
-    int rc;
+    int rc = -1;
     const char *argv[] = {
         "ip", "link", "add", NULL, "type", "veth", "peer", "name", NULL, NULL
     };
     int vethDev = 0;
     bool veth1_alloc = false;
+    bool veth2_alloc = false;
 
     VIR_DEBUG("veth1: %s veth2: %s", NULLSTR(*veth1), NULLSTR(*veth2));
 
     if (*veth1 == NULL) {
-        vethDev = getFreeVethName(veth1, vethDev);
-        if (vethDev < 0)
-            return vethDev;
+        if ((vethDev = getFreeVethName(veth1, vethDev)) < 0)
+            goto cleanup;
         VIR_DEBUG("Assigned veth1: %s", *veth1);
         veth1_alloc = true;
     }
     argv[3] = *veth1;
 
-    while (*veth2 == NULL || STREQ(*veth1, *veth2)) {
-        VIR_FREE(*veth2);
-        vethDev = getFreeVethName(veth2, vethDev + 1);
-        if (vethDev < 0) {
+    while (*veth2 == NULL) {
+        if ((vethDev = getFreeVethName(veth2, vethDev + 1)) < 0) {
             if (veth1_alloc)
                 VIR_FREE(*veth1);
-            return vethDev;
+            goto cleanup;
+        }
+
+        /* Just make sure they didn't accidentally get same name */
+        if (STREQ(*veth1, *veth2)) {
+            vethDev++;
+            VIR_FREE(*veth2);
+            continue;
         }
+
         VIR_DEBUG("Assigned veth2: %s", *veth2);
+        veth2_alloc = true;
     }
     argv[8] = *veth2;
 
@@ -124,10 +131,14 @@ int vethCreate(char** veth1, char** veth2)
     if (virRun(argv, NULL) < 0) {
         if (veth1_alloc)
             VIR_FREE(*veth1);
-        VIR_FREE(*veth2);
-        rc = -1;
+        if (veth2_alloc)
+            VIR_FREE(*veth2);
+        goto cleanup;
     }
 
+    rc = 0;
+
+cleanup:
     return rc;
 }