util: Update virNetDevGetIPAddress to get IPv6 addresses

Add static virNetDevGetifaddrsAddress to attempt to get the interface
IP address. If getifaddrs is not supported, fall back to
virNetDevGetIPv4AddressIoctl to get the IP address.

This allows IPv6 addresses to be used for <listen type='network>
with device-backed networks.

https://bugzilla.redhat.com/show_bug.cgi?id=1192318Signed-off-by: NLuyao Huang <lhuang@redhat.com>
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

src/util/virnetdev.c

@@ -33,6 +33,10 @@
 #include "virstring.h"
 #include "virutil.h"
 
+#if HAVE_GETIFADDRS
+# include <ifaddrs.h>
+#endif
+
 #include <sys/ioctl.h>
 #include <net/if.h>
 #include <fcntl.h>
@@ -1435,6 +1439,70 @@ virNetDevGetIPv4AddressIoctl(const char *ifname ATTRIBUTE_UNUSED,
 
 #endif /* ! SIOCGIFADDR */
 
+/**
+ * virNetDevGetifaddrsAddress:
+ * @ifname: name of the interface whose IP address we want
+ * @addr: filled with the IP address
+ *
+ * This function gets the IP address for the interface @ifname
+ * and stores it in @addr
+ *
+ * Returns 0 on success, -1 on failure, -2 on unsupported.
+ */
+#if HAVE_GETIFADDRS
+static int
+virNetDevGetifaddrsAddress(const char *ifname,
+                           virSocketAddrPtr addr)
+{
+    struct ifaddrs *ifap, *ifa;
+    int ret = -1;
+
+    if (getifaddrs(&ifap) < 0) {
+        virReportSystemError(errno,
+                             _("Could not get interface list for '%s'"),
+                             ifname);
+        return -1;
+    }
+
+    for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
+        int family = ifa->ifa_addr->sa_family;
+
+        if (STRNEQ_NULLABLE(ifa->ifa_name, ifname))
+            continue;
+        if (family != AF_INET6 && family != AF_INET)
+            continue;
+
+        if (family == AF_INET6) {
+            addr->len = sizeof(addr->data.inet6);
+            memcpy(&addr->data.inet6, ifa->ifa_addr, addr->len);
+        } else {
+            addr->len = sizeof(addr->data.inet4);
+            memcpy(&addr->data.inet4, ifa->ifa_addr, addr->len);
+        }
+        addr->data.stor.ss_family = family;
+        ret = 0;
+        goto cleanup;
+    }
+
+    virReportError(VIR_ERR_INTERNAL_ERROR,
+                   _("no IP address found for interface '%s'"),
+                   ifname);
+ cleanup:
+    freeifaddrs(ifap);
+    return ret;
+}
+
+#else  /* ! HAVE_GETIFADDRS */
+
+static int
+virNetDevGetifaddrsAddress(const char *ifname ATTRIBUTE_UNUSED,
+                           virSocketAddrPtr addr ATTRIBUTE_UNUSED)
+{
+    return -2;
+}
+
+#endif
+
 /**
  * virNetDevGetIPAddress:
  * @ifname: name of the interface whose IP address we want
@@ -1454,6 +1522,9 @@ virNetDevGetIPAddress(const char *ifname,
     memset(addr, 0, sizeof(*addr));
     addr->data.stor.ss_family = AF_UNSPEC;
 
+    if ((ret = virNetDevGetifaddrsAddress(ifname, addr)) != -2)
+        return ret;
+
     if ((ret = virNetDevGetIPv4AddressIoctl(ifname, addr)) != -2)
         return ret;