client: Capture server stderr and send it to the logfile.

[tripe] / server / tun-linux.c

diff --git a/server/tun-linux.c b/server/tun-linux.c
index cffeb56d0e7456ffc6ae2b53b2da91418e1db86d..11c7f37a1667b3906253a98e9daf3319ea108f89 100644 (file)
--- a/server/tun-linux.c
+++ b/server/tun-linux.c
@@ -88,47 +88,61 @@ static void t_read(int fd, unsigned mode, void *v)
 
 static void t_init(void) { return; }
 
-/* --- @t_create@ --- *
+/* --- @t_open@ --- *
  *
- * Arguments:  @peer *p@ = pointer to peer block
- *             @char **ifn@ = where to put the interface name
+ * Arguments:  @char **ifn@ = where to put the interface name
  *
- * Returns:    A tunnel block if it worked, or null on failure.
+ * Returns:    A file descriptor, or @-1@ on failure.
  *
- * Use:                Initializes a new tunnel.
+ * Use:                Opens a tunnel device.  This will run with root privileges
+ *             even if the rest of the server has dropped them.
  */
 
-static tunnel *t_create(peer *p, char **ifn)
+static int t_open(char **ifn)
 {
   int fd;
-  int f;
   struct ifreq iff;
-  tunnel *t;
 
   if ((fd = open("/dev/net/tun", O_RDWR)) < 0) {
     a_warn("TUN", "-", "linux",
-           "open-error", "/dev/net/tun", "?ERRNO",
-           A_END);
-    return (0);
+          "open-error", "/dev/net/tun", "?ERRNO",
+          A_END);
+    return (-1);
   }
-  fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
   memset(&iff, 0, sizeof(iff));
   iff.ifr_name[0] = 0;
   iff.ifr_flags = IFF_TUN | IFF_NO_PI;
-  if ((f = ioctl(fd, TUNSETIFF, &iff)) < 0) {
+  if (ioctl(fd, TUNSETIFF, &iff) < 0) {
     a_warn("TUN", "-", "linux", "config-error", "?ERRNO", A_END);
     close(fd);
-    return (0);
+    return (-1);
   }
+  iff.ifr_name[IFNAMSIZ - 1] = 0;
+  *ifn = xstrdup(iff.ifr_name);
+  return (fd);
+}
+
+/* --- @t_create@ --- *
+ *
+ * Arguments:  @peer *p@ = pointer to peer block
+ *             @int fd@ = file descriptor of tunnel device
+ *             @char **ifn@ = where to put the interface name
+ *
+ * Returns:    A tunnel block if it worked, or null on failure.
+ *
+ * Use:                Initializes a new tunnel.
+ */
+
+static tunnel *t_create(peer *p, int fd, char **ifn)
+{
+  tunnel *t;
+
+  fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
   t = CREATE(tunnel);
   t->ops = &tun_linux;
   t->p = p;
   sel_initfile(&sel, &t->f, fd, SEL_READ, t_read, t);
   sel_addfile(&t->f);
-  iff.ifr_name[IFNAMSIZ - 1] = 0;
-  *ifn = xstrdup(iff.ifr_name);
-  T( trace(T_TUNNEL, "tun-linux: attached interface %s to peer `%s'",
-          *ifn, p_name(p)); )
   return (t);
 }
 
@@ -166,6 +180,7 @@ static void t_destroy(tunnel *t)
 const tunnel_ops tun_linux = {
   "linux",
   t_init,
+  t_open,
   t_create,
   0,
   t_inject,