util: new function virNetDevIPInfoAddToDev

This patch takes the code out of
lxcContainerRenameAndEnableInterfaces() that adds all IP addresses and
IP routes to the interface, and puts it into a utility function
virNetDevIPInfoAddToDev() in virnetdevip.c so that it can be used by
anyone.

One small change in functionality -
lxcContainerRenameAndEnableInterfaces() previously would add all IP
addresses to the interface while it was still offline, then set the
interface online, and then add the routes. Because I don't want the
utility function to set the interface online, I've moved this up so
the interface is first set online, then IP addresses and routes are
added. This is the same order that the network service from
initscripts (in ifup-ether) does it, so it shouldn't pose any problem
(and hasn't, in the tests that I've run).

src/libvirt_private.syms

@@ -1931,6 +1931,7 @@ virNetDevBridgeSetVlanFiltering;
 virNetDevIPAddrAdd;
 virNetDevIPAddrDel;
 virNetDevIPAddrGet;
+virNetDevIPInfoAddToDev;
 virNetDevIPInfoClear;
 virNetDevIPRouteAdd;
 virNetDevIPRouteFree;

src/lxc/lxc_container.c

@@ -490,7 +490,7 @@ lxcContainerRenameAndEnableInterfaces(virDomainDefPtr vmDef,
                                       char **veths)
 {
     int ret = -1;
-    size_t i, j;
+    size_t i;
     const char *newname;
     virDomainNetDefPtr netDef;
     bool privNet = vmDef->features[VIR_DOMAIN_FEATURE_PRIVNET] ==
@@ -511,46 +511,21 @@ lxcContainerRenameAndEnableInterfaces(virDomainDefPtr vmDef,
         if (virNetDevSetName(veths[i], newname) < 0)
             goto cleanup;
 
-        for (j = 0; j < netDef->guestIP.nips; j++) {
+        /* Only enable this device if there is a reason to do so (either
-            virNetDevIPAddrPtr ip = netDef->guestIP.ips[j];
+         * at least one IP was specified, or link state was set to up in
-            int prefix;
+         * the config)
-            char *ipStr = virSocketAddrFormat(&ip->address);
+         */
-
-            if ((prefix = virSocketAddrGetIPPrefix(&ip->address,
-                                                   NULL, ip->prefix)) < 0) {
-                ipStr = virSocketAddrFormat(&ip->address);
-                virReportError(VIR_ERR_INTERNAL_ERROR,
-                               _("Failed to determine prefix for IP address '%s'"),
-                               ipStr);
-                VIR_FREE(ipStr);
-                goto cleanup;
-            }
-            VIR_FREE(ipStr);
-
-            if (virNetDevIPAddrAdd(newname, &ip->address, NULL, prefix) < 0)
-                goto cleanup;
-        }
-
         if (netDef->guestIP.nips ||
             netDef->linkstate == VIR_DOMAIN_NET_INTERFACE_LINK_STATE_UP) {
             VIR_DEBUG("Enabling %s", newname);
             if (virNetDevSetOnline(newname, true) < 0)
                 goto cleanup;
+        }
 
-            /* Set the routes */
+        /* set IP addresses and routes */
-            for (j = 0; j < netDef->guestIP.nroutes; j++) {
+        if (virNetDevIPInfoAddToDev(newname, &netDef->guestIP) < 0)
-                virNetDevIPRoutePtr route = netDef->guestIP.routes[j];
-
-                if (virNetDevIPRouteAdd(newname,
-                                        virNetDevIPRouteGetAddress(route),
-                                        virNetDevIPRouteGetPrefix(route),
-                                        virNetDevIPRouteGetGateway(route),
-                                        virNetDevIPRouteGetMetric(route)) < 0) {
             goto cleanup;
     }
-            }
-        }
-    }
 
     /* enable lo device only if there were other net devices */
     if ((veths || privNet) &&

src/util/virnetdevip.c

@@ -886,3 +886,63 @@ virNetDevIPInfoClear(virNetDevIPInfoPtr ip)
         virNetDevIPRouteFree(ip->routes[i]);
     VIR_FREE(ip->routes);
 }
+
+
+/**
+ * virNetDevIPInfoAddToDev:
+ * @ifname: name of device to operate on
+ * @ipInfo: list of routes and IP addresses to add to this device
+ *
+ * All IP routes and IP addresses in ipInfo are added to the named device.
+ *
+ * Returns: 0 on success, -1 (and error reported) on failure.
+ */
+int
+virNetDevIPInfoAddToDev(const char *ifname,
+                        virNetDevIPInfo const *ipInfo)
+{
+    int ret = -1;
+    size_t i;
+    char *ipStr = NULL;
+    int prefix;
+
+    /* add all IP addresses */
+    for (i = 0; i < ipInfo->nips; i++) {
+        virNetDevIPAddrPtr ip = ipInfo->ips[i];
+
+        ipStr = virSocketAddrFormat(&ip->address);
+        if ((prefix = virSocketAddrGetIPPrefix(&ip->address,
+                                               NULL, ip->prefix)) < 0) {
+            virReportError(VIR_ERR_INTERNAL_ERROR,
+                           _("Failed to determine prefix for IP address '%s'"),
+                           ipStr);
+            goto cleanup;
+        }
+        if (virNetDevIPAddrAdd(ifname, &ip->address, NULL, prefix) < 0)
+            goto cleanup;
+        VIR_FREE(ipStr);
+    }
+
+    /* add all routes */
+    for (i = 0; i < ipInfo->nroutes; i++) {
+        virNetDevIPRoutePtr route = ipInfo->routes[i];
+
+        ipStr = virSocketAddrFormat(&route->address);
+        if ((prefix = virNetDevIPRouteGetPrefix(route)) < 0) {
+            virReportError(VIR_ERR_INTERNAL_ERROR,
+                           _("Failed to determine prefix for route with destination '%s'"),
+                           ipStr);
+            goto cleanup;
+        }
+        if (virNetDevIPRouteAdd(ifname, &route->address, prefix,
+                                &route->gateway,
+                                virNetDevIPRouteGetMetric(route)) < 0)
+            goto cleanup;
+        VIR_FREE(ipStr);
+    }
+
+    ret = 0;
+ cleanup:
+    VIR_FREE(ipStr);
+    return ret;
+}

src/util/virnetdevip.h

@@ -86,5 +86,7 @@ virSocketAddrPtr virNetDevIPRouteGetGateway(virNetDevIPRoutePtr def);
 
 /* virNetDevIPInfo object */
 void virNetDevIPInfoClear(virNetDevIPInfoPtr ip);
+int virNetDevIPInfoAddToDev(const char *ifname,
+                            virNetDevIPInfo const *ipInfo);
 
 #endif /* __VIR_NETDEVIP_H__ */