util: storage: Fix parsing of IPv6 portal address for iSCSI

Split on the last colon and avoid parsing port if the split remainder
contains the closing square bracket, so that IPv6 addresses are
interpreted correctly.

src/util/virstoragefile.c

@@ -3016,7 +3016,8 @@ virStorageSourceParseBackingJSONiSCSI(virStorageSourcePtr src,
     if (VIR_STRDUP(src->hosts->name, portal) < 0)
         goto cleanup;
 
-    if ((port = strchr(src->hosts->name, ':'))) {
+    if ((port = strrchr(src->hosts->name, ':')) &&
+        !strchr(port, ']')) {
         if (virStringParsePort(port + 1, &src->hosts->port) < 0)
             goto cleanup;
 

tests/virstoragetest.c

@@ -1578,6 +1578,26 @@ mymain(void)
                        "<source protocol='iscsi' name='iqn.2016-12.com.virttest:emulated-iscsi-noauth.target/6'>\n"
                        "  <host name='test.org' port='1234'/>\n"
                        "</source>\n");
+    TEST_BACKING_PARSE("json:{\"file\":{\"driver\":\"iscsi\","
+                                       "\"transport\":\"tcp\","
+                                       "\"portal\":\"[2001::0]:1234\","
+                                       "\"target\":\"iqn.2016-12.com.virttest:emulated-iscsi-noauth.target\","
+                                       "\"lun\":6"
+                                      "}"
+                            "}",
+                       "<source protocol='iscsi' name='iqn.2016-12.com.virttest:emulated-iscsi-noauth.target/6'>\n"
+                       "  <host name='[2001::0]' port='1234'/>\n"
+                       "</source>\n");
+    TEST_BACKING_PARSE("json:{\"file\":{\"driver\":\"iscsi\","
+                                       "\"transport\":\"tcp\","
+                                       "\"portal\":\"[2001::0]\","
+                                       "\"target\":\"iqn.2016-12.com.virttest:emulated-iscsi-noauth.target\","
+                                       "\"lun\":6"
+                                      "}"
+                            "}",
+                       "<source protocol='iscsi' name='iqn.2016-12.com.virttest:emulated-iscsi-noauth.target/6'>\n"
+                       "  <host name='[2001::0]' port='3260'/>\n"
+                       "</source>\n");
     TEST_BACKING_PARSE("json:{\"file\":{\"driver\":\"sheepdog\","
                                        "\"vdi\":\"test\","
                                        "\"server\":{ \"type\":\"inet\","