network: define new API virNetworkUpdate

This patch adds a new public API virNetworkUpdate that will permit
updating an existing network configuration without requiring that the
network be destroyed/restarted for the changes to take effect.

include/libvirt/libvirt.h.in

@@ -2347,6 +2347,72 @@ virNetworkPtr           virNetworkDefineXML     (virConnectPtr conn,
  */
 int                     virNetworkUndefine      (virNetworkPtr network);
 
+/**
+ * virNetworkUpdateCommand:
+ *
+ * describes which type of update to perform on a <network>
+ * definition.
+ *
+ */
+typedef enum {
+    VIR_NETWORK_UPDATE_COMMAND_NONE      = 0, /* (invalid) */
+    VIR_NETWORK_UPDATE_COMMAND_MODIFY    = 2, /* modify an existing element */
+    VIR_NETWORK_UPDATE_COMMAND_DELETE    = 3, /* delete an existing element */
+    VIR_NETWORK_UPDATE_COMMAND_ADD_LAST  = 4, /* add an element at end of list */
+    VIR_NETWORK_UPDATE_COMMAND_ADD_FIRST = 5, /* add an element at start of list */
+#ifdef VIR_ENUM_SENTINELS
+    VIR_NETWORK_UPDATE_COMMAND_LAST
+#endif
+} virNetworkUpdateCommand;
+
+/**
+ * virNetworkUpdateSection:
+ *
+ * describes which section of a <network> definition the provided
+ * xml should be applied to.
+ *
+ */
+typedef enum {
+    VIR_NETWORK_SECTION_NONE              =  0, /* (invalid) */
+    VIR_NETWORK_SECTION_BRIDGE            =  1, /* <bridge> */
+    VIR_NETWORK_SECTION_DOMAIN            =  2, /* <domain> */
+    VIR_NETWORK_SECTION_IP                =  3, /* <ip> */
+    VIR_NETWORK_SECTION_IP_DHCP_HOST      =  4, /* <ip>/<dhcp>/<host> */
+    VIR_NETWORK_SECTION_IP_DHCP_RANGE     =  5, /* <ip>/<dhcp>/<range> */
+    VIR_NETWORK_SECTION_FORWARD           =  6, /* <forward> */
+    VIR_NETWORK_SECTION_FORWARD_INTERFACE =  7, /* <forward>/<interface> */
+    VIR_NETWORK_SECTION_FORWARD_PF        =  8, /* <forward>/<pf> */
+    VIR_NETWORK_SECTION_PORTGROUP         =  9, /* <portgroup> */
+    VIR_NETWORK_SECTION_DNS_HOST          = 10, /* <dns>/<host> */
+    VIR_NETWORK_SECTION_DNS_TXT           = 11, /* <dns>/<txt> */
+    VIR_NETWORK_SECTION_DNS_SRV           = 12, /* <dns>/<srv> */
+#ifdef VIR_ENUM_SENTINELS
+    VIR_NETWORK_SECTION_LAST
+#endif
+} virNetworkUpdateSection;
+
+/**
+ * virNetworkUpdateFlags:
+ *
+ * Flags to control options for virNetworkUpdate()
+ */
+typedef enum {
+    VIR_NETWORK_UPDATE_AFFECT_CURRENT = 0,      /* affect live if network is active,
+                                                   config if it's not active */
+    VIR_NETWORK_UPDATE_AFFECT_LIVE    = 1 << 0, /* affect live state of network only */
+    VIR_NETWORK_UPDATE_AFFECT_CONFIG  = 1 << 1, /* affect persistent config only */
+    } virNetworkUpdateFlags;
+
+/*
+ * Update an existing network definition
+ */
+int                     virNetworkUpdate(virNetworkPtr network,
+                                         unsigned int command, /* virNetworkUpdateCommand */
+                                         unsigned int section, /* virNetworkUpdateSection */
+                                         int parentIndex,
+                                         const char *xml,
+                                         unsigned int flags);
+
 /*
  * Activate persistent network
  */

src/driver.h

@@ -1119,6 +1119,13 @@ typedef virNetworkPtr
                                          const char *xml);
 typedef int
         (*virDrvNetworkUndefine)        (virNetworkPtr network);
+typedef int
+        (*virDrvNetworkUpdate)          (virNetworkPtr network,
+                                         unsigned int command, /* virNetworkUpdateCommand */
+                                         unsigned int section, /* virNetworkUpdateSection */
+                                         int parentIndex,
+                                         const char *xml,
+                                         unsigned int flags);
 typedef int
         (*virDrvNetworkCreate)          (virNetworkPtr network);
 typedef int
@@ -1169,6 +1176,7 @@ struct _virNetworkDriver {
         virDrvNetworkCreateXML      networkCreateXML;
         virDrvNetworkDefineXML      networkDefineXML;
         virDrvNetworkUndefine       networkUndefine;
+        virDrvNetworkUpdate         networkUpdate;
         virDrvNetworkCreate         networkCreate;
         virDrvNetworkDestroy        networkDestroy;
         virDrvNetworkGetXMLDesc     networkGetXMLDesc;

src/libvirt.c

@@ -10406,6 +10406,68 @@ error:
     return -1;
 }
 
+/**
+ * virNetworkUpdate:
+ * @network: pointer to a defined network
+ * @section: which section of the network to update
+ *           (see virNetworkUpdateSection for descriptions)
+ * @command: what action to perform (add/delete/modify)
+ *           (see virNetworkUpdateCommand for descriptions)
+ * @parentIndex: which parent element, if there are multiple parents
+ *           of the same type (e.g. which <ip> element when modifying
+ *           a <dhcp>/<host> element), or "-1" for "don't care" or
+ *           "automatically find appropriate one".
+ * @xml: the XML description for the network, preferably in UTF-8
+ * @flags: bitwise OR of virNetworkUpdateFlags.
+ *
+ * Update the definition of an existing network, either its live
+ * running state, its persistent configuration, or both.
+ *
+ * Returns 0 in case of success, -1 in case of error
+ */
+int
+virNetworkUpdate(virNetworkPtr network,
+                 unsigned int command, /* virNetworkUpdateCommand */
+                 unsigned int section, /* virNetworkUpdateSection */
+                 int parentIndex,
+                 const char *xml,
+                 unsigned int flags)
+{
+    virConnectPtr conn;
+    VIR_DEBUG("network=%p, section=%d, parentIndex=%d, xml=%s, flags=0x%x",
+              network, section, parentIndex, xml, flags);
+
+    virResetLastError();
+
+    if (!VIR_IS_CONNECTED_NETWORK(network)) {
+        virLibNetworkError(VIR_ERR_INVALID_NETWORK, __FUNCTION__);
+        virDispatchError(NULL);
+        return -1;
+    }
+    conn = network->conn;
+    if (conn->flags & VIR_CONNECT_RO) {
+        virLibNetworkError(VIR_ERR_OPERATION_DENIED, __FUNCTION__);
+        goto error;
+    }
+
+    virCheckNonNullArgGoto(xml, error);
+
+    if (conn->networkDriver && conn->networkDriver->networkUpdate) {
+        int ret;
+        ret = conn->networkDriver->networkUpdate(network, section, command,
+                                                 parentIndex, xml, flags);
+        if (ret < 0)
+            goto error;
+        return ret;
+    }
+
+    virLibConnError(VIR_ERR_NO_SUPPORT, __FUNCTION__);
+
+error:
+    virDispatchError(network->conn);
+    return -1;
+}
+
 /**
  * virNetworkCreate:
  * @network: pointer to a defined network

src/libvirt_public.syms

@@ -563,6 +563,7 @@ LIBVIRT_0.10.2 {
         virConnectListAllSecrets;
         virConnectListAllStoragePools;
         virDomainBlockCommit;
+        virNetworkUpdate;
         virNodeGetMemoryParameters;
         virNodeSetMemoryParameters;
         virStoragePoolListAllVolumes;