[Qemu-devel] [PATCH 1/3] Fix tap breakage on BSD hosts (no IFF_VNET_HDR)

[Qemu-devel] [PATCH 1/3] Fix tap breakage on BSD hosts (no IFF_VNET_HDR)

[Juergen Lock]

net/tap-bsd.c was assuming IFF_VNET_HDR was always available, which
I think isn't true on any BSD.

Signed-off-by: Juergen Lock <nox@jelal.kn-bremen.de>

--- a/net/tap-bsd.c
+++ b/net/tap-bsd.c
@@ -87,6 +87,17 @@ int tap_open(char *ifname, int ifname_si
     dev = devname(s.st_rdev, S_IFCHR);
     pstrcpy(ifname, ifname_size, dev);
 
+    if (*vnet_hdr) {
+        /* BSD doesn't have IFF_VNET_HDR */
+        *vnet_hdr = 0;
+
+        if (vnet_hdr_required && !*vnet_hdr) {
+            qemu_error("vnet_hdr=1 requested, but no kernel "
+                       "support for IFF_VNET_HDR available");
+            close(fd);
+            return -1;
+        }
+    }
     fcntl(fd, F_SETFL, O_NONBLOCK);
     return fd;
 }

[Qemu-devel] [PATCH 2/3] Avoid segfault on net_tap_init() failure

[Juergen Lock]

Check for fd == -1 there.

Signed-off-by: Juergen Lock <nox@jelal.kn-bremen.de>

--- a/net/tap.c
+++ b/net/tap.c
@@ -400,6 +400,9 @@ int net_init_tap(QemuOpts *opts, Monitor
         }
 
         fd = net_tap_init(opts, &vnet_hdr);
+        if (fd == -1) {
+            return -1;
+        }
     }
 
     s = net_tap_fd_init(vlan, "tap", name, fd, vnet_hdr);

[Qemu-devel] [PATCH 3/3] tap-bsd: handle ifname on FreeBSD hosts

[Juergen Lock]

Handle ifname on FreeBSD hosts; if no ifname is given, always start
the search from tap0.  (Simplified/cleaned up version of what has been
in the FreeBSD ports for a long time.)

Signed-off-by: Juergen Lock <nox@jelal.kn-bremen.de>

--- a/net/tap-bsd.c
+++ b/net/tap-bsd.c
@@ -49,11 +49,39 @@ int tap_open(char *ifname, int ifname_si
     char *dev;
     struct stat s;
 
+#ifdef __FreeBSD__
+    /* if no ifname is given, always start the search from tap0. */
+    int i;
+    char dname[100];
+
+    for (i = 0; i < 10; i++) {
+        if (*ifname) {
+            snprintf(dname, sizeof dname, "/dev/%s", ifname);
+        } else {
+            snprintf(dname, sizeof dname, "/dev/tap%d", i);
+        }
+        TFR(fd = open(dname, O_RDWR));
+        if (fd >= 0) {
+            break;
+        }
+        else if (errno == ENXIO || errno == ENOENT) {
+            break;
+        }
+        if (*ifname) {
+            break;
+        }
+    }
+    if (fd < 0) {
+        qemu_error("warning: could not open %s (%s): no virtual network emulation\n", dname, strerror(errno));
+        return -1;
+    }
+#else
     TFR(fd = open("/dev/tap", O_RDWR));
     if (fd < 0) {
         fprintf(stderr, "warning: could not open /dev/tap: no virtual network emulation\n");
         return -1;
     }
+#endif
 
     fstat(fd, &s);
     dev = devname(s.st_rdev, S_IFCHR);

[Qemu-devel] [PATCH 0/3] Misc tap fixes found on FreeBSD

[Juergen Lock]

Hi!

 I made another experimental FreeBSD qemu git snapshot port update
(see other mail), and came up with these patches when getting tap back
to working order again:

1. Fix tap breakage on BSD hosts (no IFF_VNET_HDR)
2. Avoid segfault on net_tap_init() failure
3. tap-bsd: handle ifname on FreeBSD hosts

Signed-off-by: Juergen Lock <nox@jelal.kn-bremen.de>