tap-linux: Convert tap_open() to Error

Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Message-id: 1431691143-1015-12-git-send-email-armbru@redhat.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

net/tap-linux.c

@@ -39,7 +39,6 @@
 int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
              int vnet_hdr_required, int mq_required, Error **errp)
 {
-    /* FIXME error_setg(errp, ...) on failure */
     struct ifreq ifr;
     int fd, ret;
     int len = sizeof(struct virtio_net_hdr);
@@ -47,7 +46,7 @@ int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
 
     TFR(fd = open(PATH_NET_TUN, O_RDWR));
     if (fd < 0) {
-        error_report("could not open %s: %m", PATH_NET_TUN);
+        error_setg_errno(errp, errno, "could not open %s", PATH_NET_TUN);
         return -1;
     }
     memset(&ifr, 0, sizeof(ifr));
@@ -71,8 +70,8 @@ int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
         }
 
         if (vnet_hdr_required && !*vnet_hdr) {
-            error_report("vnet_hdr=1 requested, but no kernel "
-                         "support for IFF_VNET_HDR available");
+            error_setg(errp, "vnet_hdr=1 requested, but no kernel "
+                       "support for IFF_VNET_HDR available");
             close(fd);
             return -1;
         }
@@ -87,8 +86,8 @@ int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
 
     if (mq_required) {
         if (!(features & IFF_MULTI_QUEUE)) {
-            error_report("multiqueue required, but no kernel "
-                         "support for IFF_MULTI_QUEUE available");
+            error_setg(errp, "multiqueue required, but no kernel "
+                       "support for IFF_MULTI_QUEUE available");
             close(fd);
             return -1;
         } else {
@@ -103,9 +102,11 @@ int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
     ret = ioctl(fd, TUNSETIFF, (void *) &ifr);
     if (ret != 0) {
         if (ifname[0] != '\0') {
-            error_report("could not configure %s (%s): %m", PATH_NET_TUN, ifr.ifr_name);
+            error_setg_errno(errp, errno, "could not configure %s (%s)",
+                             PATH_NET_TUN, ifr.ifr_name);
         } else {
-            error_report("could not configure %s: %m", PATH_NET_TUN);
+            error_setg_errno(errp, errno, "could not configure %s",
+                             PATH_NET_TUN);
         }
         close(fd);
         return -1;