qga: Move HW address getting to a separate function

In the next patch FreeBSD support for guest-network-get-interfaces will be
added. Previously move Linux-specific code of HW address getting to a
separate functions and add a dumb function to commands-bsd.c.

Reviewed-by: Konstantin Kostiuk <kkostiuk@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
Signed-off-by: Konstantin Kostiuk <kkostiuk@redhat.com>

qga/commands-bsd.c

@@ -167,3 +167,19 @@ GuestCpuStatsList *qmp_guest_get_cpustats(Error **errp)
     return NULL;
 }
 #endif /* CONFIG_FSFREEZE */
+
+#ifdef HAVE_GETIFADDRS
+/*
+ * Fill "buf" with MAC address by ifaddrs. Pointer buf must point to a
+ * buffer with ETHER_ADDR_LEN length at least.
+ *
+ * Returns false in case of an error, otherwise true. "obtained" arguument
+ * is true if a MAC address was obtained successful, otherwise false.
+ */
+bool guest_get_hw_addr(struct ifaddrs *ifa, unsigned char *buf,
+                       bool *obtained, Error **errp)
+{
+    *obtained = false;
+    return true;
+}
+#endif /* HAVE_GETIFADDRS */

qga/commands-common.h

@@ -56,6 +56,12 @@ int64_t qmp_guest_fsfreeze_do_freeze_list(bool has_mountpoints,
 int qmp_guest_fsfreeze_do_thaw(Error **errp);
 #endif /* CONFIG_FSFREEZE */
 
+#ifdef HAVE_GETIFADDRS
+#include <ifaddrs.h>
+bool guest_get_hw_addr(struct ifaddrs *ifa, unsigned char *buf,
+                       bool *obtained, Error **errp);
+#endif
+
 typedef struct GuestFileHandle GuestFileHandle;
 
 GuestFileHandle *guest_file_handle_find(int64_t id, Error **errp);

qga/commands-posix.c

@@ -41,20 +41,12 @@
 #endif
 #endif
 
-#ifdef __FreeBSD__
-/*
- * The code under HAVE_GETIFADDRS condition can't be compiled in FreeBSD.
- * Fix it in one of the following patches.
- */
-#undef HAVE_GETIFADDRS
-#endif
-
 #ifdef HAVE_GETIFADDRS
 #include <arpa/inet.h>
 #include <sys/socket.h>
 #include <net/if.h>
+#include <net/ethernet.h>
 #include <sys/types.h>
-#include <ifaddrs.h>
 #ifdef CONFIG_SOLARIS
 #include <sys/sockio.h>
 #endif
@@ -2889,6 +2881,57 @@ static int guest_get_network_stats(const char *name,
     return -1;
 }
 
+#ifndef __FreeBSD__
+/*
+ * Fill "buf" with MAC address by ifaddrs. Pointer buf must point to a
+ * buffer with ETHER_ADDR_LEN length at least.
+ *
+ * Returns false in case of an error, otherwise true. "obtained" argument
+ * is true if a MAC address was obtained successful, otherwise false.
+ */
+bool guest_get_hw_addr(struct ifaddrs *ifa, unsigned char *buf,
+                       bool *obtained, Error **errp)
+{
+    struct ifreq ifr;
+    int sock;
+
+    *obtained = false;
+
+    /* we haven't obtained HW address yet */
+    sock = socket(PF_INET, SOCK_STREAM, 0);
+    if (sock == -1) {
+        error_setg_errno(errp, errno, "failed to create socket");
+        return false;
+    }
+
+    memset(&ifr, 0, sizeof(ifr));
+    pstrcpy(ifr.ifr_name, IF_NAMESIZE, ifa->ifa_name);
+    if (ioctl(sock, SIOCGIFHWADDR, &ifr) == -1) {
+        /*
+         * We can't get the hw addr of this interface, but that's not a
+         * fatal error.
+         */
+        if (errno == EADDRNOTAVAIL) {
+            /* The interface doesn't have a hw addr (e.g. loopback). */
+            g_debug("failed to get MAC address of %s: %s",
+                    ifa->ifa_name, strerror(errno));
+        } else{
+            g_warning("failed to get MAC address of %s: %s",
+                      ifa->ifa_name, strerror(errno));
+        }
+    } else {
+#ifdef CONFIG_SOLARIS
+        memcpy(buf, &ifr.ifr_addr.sa_data, ETHER_ADDR_LEN);
+#else
+        memcpy(buf, &ifr.ifr_hwaddr.sa_data, ETHER_ADDR_LEN);
+#endif
+        *obtained = true;
+    }
+    close(sock);
+    return true;
+}
+#endif /* __FreeBSD__ */
+
 /*
  * Build information about guest interfaces
  */
@@ -2909,9 +2952,8 @@ GuestNetworkInterfaceList *qmp_guest_network_get_interfaces(Error **errp)
         GuestNetworkInterfaceStat *interface_stat = NULL;
         char addr4[INET_ADDRSTRLEN];
         char addr6[INET6_ADDRSTRLEN];
-        int sock;
-        struct ifreq ifr;
-        unsigned char *mac_addr;
+        unsigned char mac_addr[ETHER_ADDR_LEN];
+        bool obtained;
         void *p;
 
         g_debug("Processing %s interface", ifa->ifa_name);
@@ -2926,45 +2968,17 @@ GuestNetworkInterfaceList *qmp_guest_network_get_interfaces(Error **errp)
         }
 
         if (!info->has_hardware_address) {
-            /* we haven't obtained HW address yet */
-            sock = socket(PF_INET, SOCK_STREAM, 0);
-            if (sock == -1) {
-                error_setg_errno(errp, errno, "failed to create socket");
+            if (!guest_get_hw_addr(ifa, mac_addr, &obtained, errp)) {
                 goto error;
             }
-
-            memset(&ifr, 0, sizeof(ifr));
-            pstrcpy(ifr.ifr_name, IF_NAMESIZE, info->name);
-            if (ioctl(sock, SIOCGIFHWADDR, &ifr) == -1) {
-                /*
-                 * We can't get the hw addr of this interface, but that's not a
-                 * fatal error. Don't set info->hardware_address, but keep
-                 * going.
-                 */
-                if (errno == EADDRNOTAVAIL) {
-                    /* The interface doesn't have a hw addr (e.g. loopback). */
-                    g_debug("failed to get MAC address of %s: %s",
-                            ifa->ifa_name, strerror(errno));
-                } else{
-                    g_warning("failed to get MAC address of %s: %s",
-                              ifa->ifa_name, strerror(errno));
-                }
-
-            } else {
-#ifdef CONFIG_SOLARIS
-                mac_addr = (unsigned char *) &ifr.ifr_addr.sa_data;
-#else
-                mac_addr = (unsigned char *) &ifr.ifr_hwaddr.sa_data;
-#endif
+            if (obtained) {
                 info->hardware_address =
                     g_strdup_printf("%02x:%02x:%02x:%02x:%02x:%02x",
                                     (int) mac_addr[0], (int) mac_addr[1],
                                     (int) mac_addr[2], (int) mac_addr[3],
                                     (int) mac_addr[4], (int) mac_addr[5]);
-
                 info->has_hardware_address = true;
             }
-            close(sock);
         }
 
         if (ifa->ifa_addr &&