[libvirt] [PATCH] network driver: Fix regression defining colliding networks at daemon startup.

[Cole Robinson]

If two virtual networks have the same hardcoded bridge device (which
prevents them from being active simultaneously) we still want to define
them at daemon startup, so the user has a fighting chance of correcting
the XML error.

Add an extra flag to SetBridge to avoid reporting an error if there is
a bridge collision, and use this when loading network configs at startup.

This regressed via commit 6c2c73fc.

Signed-off-by: Cole Robinson <crobinso at redhat.com>
---
 src/network_conf.c   |   17 +++++++++--------
 src/network_conf.h   |    3 ++-
 src/network_driver.c |    4 ++--
 3 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/src/network_conf.c b/src/network_conf.c
index b4da3fb..1e0cbb8 100644
--- a/src/network_conf.c
+++ b/src/network_conf.c
@@ -724,7 +724,6 @@ virNetworkObjPtr virNetworkLoadConfig(virConnectPtr conn,
     virNetworkDefPtr def = NULL;
     virNetworkObjPtr net;
     int autostart;
-    char *tmp;
 
     if ((configFile = virNetworkConfigFile(conn, configDir, name)) == NULL)
         goto error;
@@ -745,13 +744,10 @@ virNetworkObjPtr virNetworkLoadConfig(virConnectPtr conn,
         goto error;
     }
 
-    /* Generate a bridge if none is found, but don't check for collisions
+    /* Generate a bridge if none is specified, but don't check for collisions
      * if a bridge is hardcoded, so the network is at least defined
      */
-    if ((tmp = virNetworkAllocateBridge(conn, nets, def->bridge)) != NULL) {
-        VIR_FREE(def->bridge);
-        def->bridge = tmp;
-    } else
+    if (virNetworkSetBridgeName(conn, nets, def, 0))
         goto error;
 
     if (!(net = virNetworkAssignDef(conn, nets, def)))
@@ -913,12 +909,17 @@ char *virNetworkAllocateBridge(virConnectPtr conn,
 
 int virNetworkSetBridgeName(virConnectPtr conn,
                             const virNetworkObjListPtr nets,
-                            virNetworkDefPtr def) {
+                            virNetworkDefPtr def,
+                            int check_collision) {
 
     int ret = -1;
 
     if (def->bridge && !strstr(def->bridge, "%d")) {
-        if (virNetworkBridgeInUse(nets, def->bridge, def->name)) {
+        /* We may want to skip collision detection in this case (ex. when
+         * loading configs at daemon startup, so the network is at least
+         * defined. */
+        if (check_collision &&
+            virNetworkBridgeInUse(nets, def->bridge, def->name)) {
             networkReportError(conn, NULL, NULL, VIR_ERR_INTERNAL_ERROR,
                                _("bridge name '%s' already in use."),
                                def->bridge);
diff --git a/src/network_conf.h b/src/network_conf.h
index 365d469..1d51c83 100644
--- a/src/network_conf.h
+++ b/src/network_conf.h
@@ -179,7 +179,8 @@ char *virNetworkAllocateBridge(virConnectPtr conn,
 
 int virNetworkSetBridgeName(virConnectPtr conn,
                             const virNetworkObjListPtr nets,
-                            virNetworkDefPtr def);
+                            virNetworkDefPtr def,
+                            int check_collision);
 
 void virNetworkObjLock(virNetworkObjPtr obj);
 void virNetworkObjUnlock(virNetworkObjPtr obj);
diff --git a/src/network_driver.c b/src/network_driver.c
index 3518e01..10d5fd3 100644
--- a/src/network_driver.c
+++ b/src/network_driver.c
@@ -1096,7 +1096,7 @@ static virNetworkPtr networkCreate(virConnectPtr conn, const char *xml) {
     if (!(def = virNetworkDefParseString(conn, xml)))
         goto cleanup;
 
-    if (virNetworkSetBridgeName(conn, &driver->networks, def))
+    if (virNetworkSetBridgeName(conn, &driver->networks, def, 1))
         goto cleanup;
 
     if (!(network = virNetworkAssignDef(conn,
@@ -1133,7 +1133,7 @@ static virNetworkPtr networkDefine(virConnectPtr conn, const char *xml) {
     if (!(def = virNetworkDefParseString(conn, xml)))
         goto cleanup;
 
-    if (virNetworkSetBridgeName(conn, &driver->networks, def))
+    if (virNetworkSetBridgeName(conn, &driver->networks, def, 1))
         goto cleanup;
 
     if (!(network = virNetworkAssignDef(conn,
-- 
1.6.0.6