virsh: Don't leak list of volumes when undefining domain with storage

Use the new semantics of vshStringToArray to avoid leaking the array of
volumes to be deleted. The array would be leaked in case the first
volume was found in the domain definition. Also refactor the code a bit
to sanitize naming of variables hoding arrays and dimensions of the
arrays.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=996050

tools/virsh-domain.c

@@ -2932,24 +2932,23 @@ cmdUndefine(vshControl *ctl, const vshCmd *cmd)
     int rc = -1;
     int running;
     /* list of volumes to remove along with this domain */
-    vshUndefineVolume *vlist = NULL;
-    int nvols = 0;
-    const char *volumes = NULL;
-    char **volume_tokens = NULL;
-    char *volume_tok = NULL;
-    int nvolume_tokens = 0;
-    char *def = NULL;
+    const char *vol_string = NULL;  /* string containing volumes to delete */
+    char **vol_list = NULL;         /* tokenized vol_string */
+    int nvol_list = 0;
+    vshUndefineVolume *vols = NULL; /* info about the volumes to delete*/
+    size_t nvols = 0;
+    char *def = NULL;               /* domain def */
+    xmlDocPtr doc = NULL;
+    xmlXPathContextPtr ctxt = NULL;
+    xmlNodePtr *vol_nodes = NULL;   /* XML nodes of volumes of the guest */
+    int nvol_nodes;
     char *source = NULL;
     char *target = NULL;
     size_t i;
     size_t j;
-    xmlDocPtr doc = NULL;
-    xmlXPathContextPtr ctxt = NULL;
-    xmlNodePtr *vol_nodes = NULL;
-    int nvolumes = 0;
-    bool vol_not_found = false;
 
-    ignore_value(vshCommandOptString(cmd, "storage", &volumes));
+
+    ignore_value(vshCommandOptString(cmd, "storage", &vol_string));
 
     if (managed_save) {
         flags |= VIR_DOMAIN_UNDEFINE_MANAGED_SAVE;
@@ -3017,14 +3016,17 @@ cmdUndefine(vshControl *ctl, const vshCmd *cmd)
     }
 
     /* Stash domain description for later use */
-    if (volumes || remove_all_storage) {
+    if (vol_string || remove_all_storage) {
         if (running) {
-            vshError(ctl, _("Storage volume deletion is supported only on stopped domains"));
+            vshError(ctl,
+                     _("Storage volume deletion is supported only on "
+                       "stopped domains"));
             goto cleanup;
         }
 
-        if (volumes && remove_all_storage) {
-            vshError(ctl, _("Specified both --storage and --remove-all-storage"));
+        if (vol_string && remove_all_storage) {
+            vshError(ctl,
+                     _("Specified both --storage and --remove-all-storage"));
             goto cleanup;
         }
 
@@ -3038,20 +3040,17 @@ cmdUndefine(vshControl *ctl, const vshCmd *cmd)
             goto error;
 
         /* tokenize the string from user and save it's parts into an array */
-        if (volumes) {
-            if ((nvolume_tokens = vshStringToArray(volumes, &volume_tokens)) < 0)
-                goto cleanup;
-        }
+        if (vol_string &&
+            (nvol_list = vshStringToArray(vol_string, &vol_list)) < 0)
+            goto error;
 
-        if ((nvolumes = virXPathNodeSet("./devices/disk", ctxt,
+        if ((nvol_nodes = virXPathNodeSet("./devices/disk", ctxt,
                                           &vol_nodes)) < 0)
             goto error;
 
-        if (nvolumes > 0)
-            vlist = vshCalloc(ctl, nvolumes, sizeof(*vlist));
-
-        for (i = 0; i < nvolumes; i++) {
+        for (i = 0; i < nvol_nodes; i++) {
             ctxt->node = vol_nodes[i];
+            vshUndefineVolume vol;
             VIR_FREE(source);
             VIR_FREE(target);
 
@@ -3063,56 +3062,53 @@ cmdUndefine(vshControl *ctl, const vshCmd *cmd)
                                           "./source/@file|"
                                           "./source/@dir|"
                                           "./source/@name|"
-                                          "./source/@dev)", ctxt))) {
-                if (last_error && last_error->code != VIR_ERR_OK)
-                    goto error;
-                else
+                                          "./source/@dev)", ctxt)))
                 continue;
-            }
 
             /* lookup if volume was selected by user */
-            if (volumes) {
-                volume_tok = NULL;
-                for (j = 0; j < nvolume_tokens; j++) {
-                    if (volume_tokens[j] &&
-                        (STREQ(volume_tokens[j], target) ||
-                         STREQ(volume_tokens[j], source))) {
-                        volume_tok = volume_tokens[j];
-                        volume_tokens[j] = NULL;
+            if (vol_list) {
+                bool found = false;
+                for (j = 0; j < nvol_list; j++) {
+                    if (STREQ_NULLABLE(vol_list[j], target) ||
+                        STREQ_NULLABLE(vol_list[j], source)) {
+                        VIR_FREE(vol_list[j]);
+                        found = true;
                         break;
                     }
                 }
-                if (!volume_tok)
+                if (!found)
                     continue;
             }
 
-            if (!(vlist[nvols].vol = virStorageVolLookupByPath(ctl->conn,
-                                                               source))) {
+            if (!(vol.vol = virStorageVolLookupByPath(ctl->conn, source))) {
                 vshPrint(ctl,
                          _("Storage volume '%s'(%s) is not managed by libvirt. "
                            "Remove it manually.\n"), target, source);
                 vshResetLibvirtError();
                 continue;
             }
-            vlist[nvols].source = source;
-            vlist[nvols].target = target;
+
+            vol.source = source;
+            vol.target = target;
             source = NULL;
             target = NULL;
-            nvols++;
+            if (VIR_APPEND_ELEMENT(vols, nvols, vol) < 0)
+                goto cleanup;
         }
 
         /* print volumes specified by user that were not found in domain definition */
-        if (volumes) {
-            for (j = 0; j < nvolume_tokens; j++) {
-                if (volume_tokens[j]) {
-                    vshError(ctl, _("Volume '%s' was not found in domain's "
-                                    "definition.\n"),
-                             volume_tokens[j]);
-                    vol_not_found = true;
+        if (vol_list) {
+            bool found = false;
+            for (i = 0; i < nvol_list; i++) {
+                if (vol_list[i]) {
+                    vshError(ctl,
+                             _("Volume '%s' was not found in domain's "
+                               "definition.\n"), vol_list[i]);
+                    found = true;
                 }
             }
 
-            if (vol_not_found)
+            if (found)
                 goto cleanup;
         }
     }
@@ -3173,9 +3169,9 @@ out:
         for (i = 0; i < nvols; i++) {
             if (wipe_storage) {
                 vshPrint(ctl, _("Wiping volume '%s'(%s) ... "),
-                         vlist[i].target, vlist[i].source);
+                         vols[i].target, vols[i].source);
                 fflush(stdout);
-                if (virStorageVolWipe(vlist[i].vol, 0) < 0) {
+                if (virStorageVolWipe(vols[i].vol, 0) < 0) {
                     vshError(ctl, _("Failed! Volume not removed."));
                     ret = false;
                     continue;
@@ -3185,13 +3181,13 @@ out:
             }
 
             /* delete the volume */
-            if (virStorageVolDelete(vlist[i].vol, 0) < 0) {
+            if (virStorageVolDelete(vols[i].vol, 0) < 0) {
                 vshError(ctl, _("Failed to remove storage volume '%s'(%s)"),
-                         vlist[i].target, vlist[i].source);
+                         vols[i].target, vols[i].source);
                 ret = false;
             } else {
                 vshPrint(ctl, _("Volume '%s'(%s) removed.\n"),
-                         vlist[i].target, vlist[i].source);
+                         vols[i].target, vols[i].source);
             }
         }
     }
@@ -3200,17 +3196,17 @@ cleanup:
     VIR_FREE(source);
     VIR_FREE(target);
     for (i = 0; i < nvols; i++) {
-        VIR_FREE(vlist[i].source);
-        VIR_FREE(vlist[i].target);
-        if (vlist[i].vol)
-            virStorageVolFree(vlist[i].vol);
+        VIR_FREE(vols[i].source);
+        VIR_FREE(vols[i].target);
+        if (vols[i].vol)
+            virStorageVolFree(vols[i].vol);
     }
-    VIR_FREE(vlist);
+    VIR_FREE(vols);
+
+    for (i = 0; i < nvol_list; i++)
+        VIR_FREE(vol_list[i]);
+    VIR_FREE(vol_list);
 
-    if (volume_tokens) {
-        VIR_FREE(*volume_tokens);
-        VIR_FREE(volume_tokens);
-    }
     VIR_FREE(def);
     VIR_FREE(vol_nodes);
     xmlFreeDoc(doc);