[libvirt] [PATCH v9 1/4] domifaddr: Implement the public APIs

Daniel P. Berrange berrange at redhat.com
Mon Mar 9 15:09:28 UTC 2015


From: Nehal J Wani <nehaljw.kkd1 at gmail.com>

Define helper function virDomainInterfaceFree, which allows
the upper layer application to free the domain interface object
conveniently.

The API is going to provide multiple methods by flags, e.g.
  * Query guest agent
  * Parse DHCP lease file

include/libvirt/libvirt-domain.h
  * Define virDomainInterfaceAddresses, virDomainInterfaceFree
  * Define structs virDomainInterface, virDomainIPAddress

src/driver-hypervisor.h:
  * Define domainInterfaceAddresses

src/libvirt-domain.c:
  * Implement virDomainInterfaceAddresses
  * Implement virDomainInterfaceFree

src/libvirt_public.syms:
  * Export the new symbols

Signed-off-by: Nehal J Wani <nehaljw.kkd1 at gmail.com>
---
 include/libvirt/libvirt-domain.h |  28 +++++++++
 src/driver-hypervisor.h          |   6 ++
 src/libvirt-domain.c             | 123 +++++++++++++++++++++++++++++++++++++++
 src/libvirt_public.syms          |   2 +
 4 files changed, 159 insertions(+)

diff --git a/include/libvirt/libvirt-domain.h b/include/libvirt/libvirt-domain.h
index 9487b80..448e235 100644
--- a/include/libvirt/libvirt-domain.h
+++ b/include/libvirt/libvirt-domain.h
@@ -3725,5 +3725,33 @@ typedef struct _virTypedParameter virMemoryParameter;
  */
 typedef virMemoryParameter *virMemoryParameterPtr;
 
+typedef enum {
+    VIR_DOMAIN_INTERFACE_ADDRESSES_SRC_LEASE = 0, /* Parse DHCP lease file */
+    VIR_DOMAIN_INTERFACE_ADDRESSES_SRC_AGENT = 1, /* Query qemu guest agent */
+} virDomainInterfaceAddressesSource;
+
+typedef struct _virDomainInterfaceIPAddress virDomainIPAddress;
+typedef virDomainIPAddress *virDomainIPAddressPtr;
+struct _virDomainInterfaceIPAddress {
+    int type;                /* virIPAddrType */
+    char *addr;              /* IP address */
+    unsigned int prefix;     /* IP address prefix */
+};
+
+typedef struct _virDomainInterface virDomainInterface;
+typedef virDomainInterface *virDomainInterfacePtr;
+struct _virDomainInterface {
+    char *name;                     /* interface name */
+    char *hwaddr;                   /* hardware address */
+    unsigned int naddrs;            /* number of items in @addrs */
+    virDomainIPAddressPtr addrs;    /* array of IP addresses */
+};
+
+int virDomainInterfaceAddresses(virDomainPtr dom,
+                                virDomainInterfacePtr **ifaces,
+                                unsigned int source,
+                                unsigned int flags);
+
+void virDomainInterfaceFree(virDomainInterfacePtr iface);
 
 #endif /* __VIR_LIBVIRT_DOMAIN_H__ */
diff --git a/src/driver-hypervisor.h b/src/driver-hypervisor.h
index c2b4cd8..0e729c4 100644
--- a/src/driver-hypervisor.h
+++ b/src/driver-hypervisor.h
@@ -1178,6 +1178,11 @@ typedef int
                         unsigned int cellCount,
                         unsigned int flags);
 
+typedef int
+(*virDrvDomainInterfaceAddresses)(virDomainPtr dom,
+                                  virDomainInterfacePtr **ifaces,
+                                  unsigned int source,
+                                  unsigned int flags);
 
 typedef struct _virHypervisorDriver virHypervisorDriver;
 typedef virHypervisorDriver *virHypervisorDriverPtr;
@@ -1404,6 +1409,7 @@ struct _virHypervisorDriver {
     virDrvConnectGetAllDomainStats connectGetAllDomainStats;
     virDrvNodeAllocPages nodeAllocPages;
     virDrvDomainGetFSInfo domainGetFSInfo;
+    virDrvDomainInterfaceAddresses domainInterfaceAddresses;
 };
 
 
diff --git a/src/libvirt-domain.c b/src/libvirt-domain.c
index 04545fd..58fe94a 100644
--- a/src/libvirt-domain.c
+++ b/src/libvirt-domain.c
@@ -11338,3 +11338,126 @@ virDomainFSInfoFree(virDomainFSInfoPtr info)
         VIR_FREE(info->devAlias[i]);
     VIR_FREE(info->devAlias);
 }
+
+/**
+ * virDomainInterfaceAddresses:
+ * @dom: domain object
+ * @ifaces: pointer to an array of pointers pointing to interface objects
+ * @source: one of the virDomainInterfaceAddressesSource constants
+ * @flags: currently unused, pass zero
+ *
+ * Return a pointer to the allocated array of pointers pointing to interfaces
+ * present in given domain along with their IP and MAC addresses. Note that
+ * single interface can have multiple or even 0 IP address.
+ *
+ * This API dynamically allocates the virDomainInterfacePtr struct based on
+ * how many interfaces domain @dom has, usually there's 1:1 correlation. The
+ * count of the interfaces is returned as the return value.
+ *
+ * If @source is VIR_DOMAIN_INTERFACE_ADDRESSES_SRC_LEASE, the DHCP lease
+ * file associated with any virtual networks will be examined to obtain
+ * the interface addresses. This only returns data for interfaces which
+ * are connected to virtual networks managed by libvirt.
+ *
+ * If @source is VIR_DOMAIN_INTERFACE_ADDRESSES_SRC_AGENT, a configured
+ * guest agent is needed for successful return from this API. Moreover, if
+ * guest agent is used then the interface name is the one seen by guest OS.
+ * To match such interface with the one from @dom XML use MAC address or IP
+ * range.
+ *
+ * @ifaces->name and @ifaces->hwaddr are never NULL.
+ *
+ * The caller *must* free @ifaces when no longer needed. Usual use case
+ * looks like this:
+ *
+ * virDomainInterfacePtr *ifaces = NULL;
+ * int ifaces_count = 0;
+ * size_t i, j;
+ * virDomainPtr dom = ... obtain a domain here ...;
+ *
+ * if ((ifaces_count = virDomainInterfaceAddresses(dom, &ifaces,
+ *           VIR_DOMAIN_INTERFACE_ADDRESSES_SRC_LEASE)) < 0)
+ *     goto cleanup;
+ *
+ * ... do something with returned values, for example:
+ * for (i = 0; i < ifaces_count; i++) {
+ *     printf("name: %s", ifaces[i]->name);
+ *     if (ifaces[i]->hwaddr)
+ *         printf(" hwaddr: %s", ifaces[i]->hwaddr);
+ *
+ *     for (j = 0; j < ifaces[i]->naddrs; j++) {
+ *         virDomainIPAddressPtr ip_addr = ifaces[i]->addrs + j;
+ *         printf("[addr: %s prefix: %d type: %d]",
+ *                ip_addr->addr, ip_addr->prefix, ip_addr->type);
+ *     }
+ *     printf("\n");
+ * }
+ *
+ * cleanup:
+ *     if (ifaces)
+ *         for (i = 0; i < ifaces_count; i++)
+ *             virDomainInterfaceFree(ifaces[i]);
+ *     free(ifaces);
+ *
+ * Returns the number of interfaces on success, -1 in case of error.
+ */
+int
+virDomainInterfaceAddresses(virDomainPtr dom,
+                            virDomainInterfacePtr **ifaces,
+                            unsigned int source,
+                            unsigned int flags)
+{
+    virConnectPtr conn;
+
+    VIR_DOMAIN_DEBUG(dom, "ifaces=%p, source=%d, flags=%x", ifaces, source, flags);
+
+    virResetLastError();
+
+    conn = dom->conn;
+
+    virCheckDomainReturn(dom, -1);
+    virCheckNonNullArgGoto(ifaces, error);
+    virCheckReadOnlyGoto(conn->flags, error);
+
+    *ifaces = NULL;
+
+    if (conn->driver->domainInterfaceAddresses) {
+        int ret;
+        ret = conn->driver->domainInterfaceAddresses(dom, ifaces, source, flags);
+        if (ret < 0)
+            goto error;
+        return ret;
+    }
+
+    virReportError(VIR_ERR_NO_SUPPORT, __FUNCTION__);
+
+ error:
+    virDispatchError(dom->conn);
+    return -1;
+}
+
+
+/**
+ * virDomainInterfaceFree:
+ * @iface: an interface object
+ *
+ * Free the interface object. The data structure is
+ * freed and should not be used thereafter.
+ */
+void
+virDomainInterfaceFree(virDomainInterfacePtr iface)
+{
+    size_t i;
+
+    if (!iface)
+        return;
+
+    VIR_FREE(iface->name);
+    VIR_FREE(iface->hwaddr);
+
+    for (i = 0; i < iface->naddrs; i++)
+        VIR_FREE(iface->addrs[i].addr);
+    VIR_FREE(iface->addrs);
+
+    VIR_FREE(iface);
+}
diff --git a/src/libvirt_public.syms b/src/libvirt_public.syms
index 34852c1..64c455d 100644
--- a/src/libvirt_public.syms
+++ b/src/libvirt_public.syms
@@ -699,6 +699,8 @@ LIBVIRT_1.2.14 {
     global:
         virDomainIOThreadsInfoFree;
         virDomainGetIOThreadsInfo;
+        virDomainInterfaceAddresses;
+        virDomainInterfaceFree;
 } LIBVIRT_1.2.12;
 
 # .... define new API here using predicted next version number ....
-- 
2.1.0




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