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[libvirt] [PATCHv6 1/5] domifaddr: Implement the public APIs



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 lease file of dnsmasq
  * DHCP snooping

At this stage, it will only work with guest agent. Passing other
flags will result in error: "Method hasn't been implemented yet"

include/libvirt/libvirt.h.in:
  * Define virDomainInterfaceAddresses, virDomainInterfaceFree
  * Define structs virDomainInterface, virDomainIPAddress

python/generator.py:
  * Skip the auto-generation for virDomainInterfaceAddresses
    and virDomainInterfaceFree

src/driver.h:
  * Define domainInterfaceAddresses

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

src/libvirt_public.syms:
  * Export the new symbols

---
 include/libvirt/libvirt.h.in |  38 ++++++++++++
 python/generator.py          |   3 +
 src/driver.h                 |   6 ++
 src/libvirt.c                | 135 +++++++++++++++++++++++++++++++++++++++++++
 src/libvirt_public.syms      |   6 ++
 5 files changed, 188 insertions(+)

diff --git a/include/libvirt/libvirt.h.in b/include/libvirt/libvirt.h.in
index a47e33c..0995080 100644
--- a/include/libvirt/libvirt.h.in
+++ b/include/libvirt/libvirt.h.in
@@ -2044,6 +2044,44 @@ int                     virDomainGetInterfaceParameters (virDomainPtr dom,
                                                          virTypedParameterPtr params,
                                                          int *nparams, unsigned int flags);
 
+typedef enum {
+    VIR_DOMAIN_INTERFACE_ADDRESSES_SNOOP = (1 << 0), /* Snoop traffic */
+    VIR_DOMAIN_INTERFACE_ADDRESSES_LEASE = (1 << 1), /* Parse DHCP lease file */
+    VIR_DOMAIN_INTERFACE_ADDRESSES_AGENT = (1 << 2), /* Query qemu guest agent */
+} virDomainInterfaceAddressesFlags;
+
+typedef enum {
+    VIR_IP_ADDR_TYPE_IPV4 = 0,
+    VIR_IP_ADDR_TYPE_IPV6 = 1,
+
+#ifdef VIR_ENUM_SENTINELS
+    VIR_IP_ADDR_TYPE_LAST,
+#endif
+} virIPAddrType;
+
+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 flags);
+
+void virDomainInterfaceFree(virDomainInterfacePtr iface);
+
 /* Management of domain block devices */
 
 int                     virDomainBlockPeek (virDomainPtr dom,
diff --git a/python/generator.py b/python/generator.py
index fb321c6..50f779b 100755
--- a/python/generator.py
+++ b/python/generator.py
@@ -458,6 +458,7 @@ skip_impl = (
     'virNodeGetMemoryParameters',
     'virNodeSetMemoryParameters',
     'virNodeGetCPUMap',
+    'virDomainInterfaceAddresses',
     'virDomainMigrate3',
     'virDomainMigrateToURI3',
 )
@@ -560,6 +561,8 @@ skip_function = (
     "virTypedParamsGetString",
     "virTypedParamsGetUInt",
     "virTypedParamsGetULLong",
+
+    "virDomainInterfaceFree", # Only useful in C
 )
 
 lxc_skip_function = (
diff --git a/src/driver.h b/src/driver.h
index be64333..210a910 100644
--- a/src/driver.h
+++ b/src/driver.h
@@ -518,6 +518,11 @@ typedef int
                                       unsigned int flags);
 
 typedef int
+(*virDrvDomainInterfaceAddresses)(virDomainPtr dom,
+                                  virDomainInterfacePtr **ifaces,
+                                  unsigned int flags);
+
+typedef int
 (*virDrvDomainMemoryStats)(virDomainPtr domain,
                            struct _virDomainMemoryStat *stats,
                            unsigned int nr_stats,
@@ -1238,6 +1243,7 @@ struct _virDriver {
     virDrvDomainInterfaceStats domainInterfaceStats;
     virDrvDomainSetInterfaceParameters domainSetInterfaceParameters;
     virDrvDomainGetInterfaceParameters domainGetInterfaceParameters;
+    virDrvDomainInterfaceAddresses domainInterfaceAddresses;
     virDrvDomainMemoryStats domainMemoryStats;
     virDrvDomainBlockPeek domainBlockPeek;
     virDrvDomainMemoryPeek domainMemoryPeek;
diff --git a/src/libvirt.c b/src/libvirt.c
index 07a3fd5..7a5759b 100644
--- a/src/libvirt.c
+++ b/src/libvirt.c
@@ -8643,6 +8643,116 @@ error:
     return -1;
 }
 
+ /**
+ * virDomainInterfaceAddresses:
+ * @dom: domain object
+ * @ifaces: pointer to an array of pointers pointing to interface objects
+ * @flags: bitwise-OR of virDomainInterfaceAddressesFlags
+ *
+ * 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.
+ *
+ * In case @flags includes VIR_DOMAIN_INTERFACE_ADDRESSES_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.
+ *
+ * Both the methods, pasrsing leases file and traffic snooping will return
+ * the interface name of the form "vnetN", which is different from what guest
+ * agent returns (like ethN or emN). And since the MAC address from guest agent
+ * might be different with what @dom XML specifies, we have no way to convert it
+ * into the names present in @dom config. Hence, it is not recommended to mix
+ * the flag ..._AGENT with ..._LEASE or ..._SNOOP as it may lead to ambiguous
+ * results because we cannot be sure if the name came from the agent or from
+ * the other method.
+ *
+ * If 0 is passed as @flags, libvirt will choose the best way, and won't
+ * include agent in it.
+ *
+ * @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, 0)) < 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 flags)
+{
+    virConnectPtr conn;
+
+    VIR_DOMAIN_DEBUG(dom, "ifaces=%p, flags=%x", ifaces, flags);
+
+    virResetLastError();
+
+    if (!VIR_IS_CONNECTED_DOMAIN(dom)) {
+        virLibDomainError(VIR_ERR_INVALID_DOMAIN, __FUNCTION__);
+        virDispatchError(NULL);
+        return -1;
+    }
+
+    conn = dom->conn;
+
+    virCheckNonNullArgGoto(ifaces, error);
+
+    if ((flags & VIR_DOMAIN_INTERFACE_ADDRESSES_AGENT)
+        && (conn->flags & VIR_CONNECT_RO)) {
+        virLibConnError(VIR_ERR_OPERATION_DENIED, "%s",
+                        _("Cannot query guest agent in readonly mode"));
+        goto error;
+    }
+
+    if (conn->driver->domainInterfaceAddresses) {
+        int ret;
+        ret = conn->driver->domainInterfaceAddresses(dom, ifaces, flags);
+        if (ret < 0)
+            goto error;
+        return ret;
+    }
+
+    virLibConnError(VIR_ERR_NO_SUPPORT, __FUNCTION__);
+
+error:
+    virDispatchError(dom->conn);
+    return -1;
+}
+
 /**
  * virDomainMemoryStats:
  * @dom: pointer to the domain object
@@ -21961,3 +22071,28 @@ 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 bbdf78a..35f3a3e 100644
--- a/src/libvirt_public.syms
+++ b/src/libvirt_public.syms
@@ -634,4 +634,10 @@ LIBVIRT_1.1.1 {
         virDomainSetMemoryStatsPeriod;
 } LIBVIRT_1.1.0;
 
+LIBVIRT_1.1.3 {
+    global:
+        virDomainInterfaceAddresses;
+        virDomainInterfaceFree;
+} LIBVIRT_1.1.1;
+
 # .... define new API here using predicted next version number ....
-- 
1.7.11.7


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