peer, tunnels: New file-descriptor opening interface.

[tripe] / server / tun-bsd.c

diff --git a/server/tun-bsd.c b/server/tun-bsd.c
index 3a45b1e9c459c1d13b6e47264e8031dba95eb54c..200b5d9325a65fecf3c9d1a831b533ee10079bb2 100644 (file)
--- a/server/tun-bsd.c
+++ b/server/tun-bsd.c
@@ -1,6 +1,4 @@
 /* -*-c-*-
- *
- * $Id$
  *
  * Tunnel interface for 4.4BSD-derived systems
  *
@@ -40,7 +38,6 @@ struct tunnel {
   const tunnel_ops *ops;               /* Pointer to operations */
   sel_file f;                          /* Selector for tunnel device */
   struct peer *p;                      /* Pointer to my peer */
-  unsigned n;                          /* Number of my tunnel device */
 };
 
 /* --- @t_read@ --- *
@@ -85,21 +82,20 @@ 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;
   unsigned n;
-  tunnel *t;
   char buf[16];
 
   n = 0;
@@ -109,28 +105,41 @@ static tunnel *t_create(peer *p, char **ifn)
       break;
     switch (errno) {
       case EBUSY:
-       T( trace(T_TUNNEL, "tunnel device %u busy: skipping", n); )
-       break;
+       T( trace(T_TUNNEL, "tunnel device %u busy: skipping", n); )
+       break;
       case ENOENT:
-       a_warn("TUN", "-", "bsd", "no-tunnel-devices", A_END);
-       return (0);
+       a_warn("TUN", "-", "bsd", "no-tunnel-devices", A_END);
+       return (-1);
       default:
-       a_warn("TUN", "-", "open-error", "%s", buf, "?ERRNO", A_END);
-       break;
+       a_warn("TUN", "-", "open-error", "%s", buf, "?ERRNO", A_END);
+       break;
     }
     n++;
   }
+  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_bsd;
-  fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
   t->p = p;
-  t->n = n;
   sel_initfile(&sel, &t->f, fd, SEL_READ, t_read, t);
   sel_addfile(&t->f);
-  *ifn = xstrdup(buf + 5);
-  T( trace(T_TUNNEL, "tun-bsd: attached interface %s to peer `%s'",
-          *ifn, p_name(p)); )
   return (t);
 }
 
@@ -163,15 +172,12 @@ static void t_inject(tunnel *t, buf *b)
  */
 
 static void t_destroy(tunnel *t)
-{
-  sel_rmfile(&t->f);
-  close(t->f.fd);
-  DESTROY(t);
-}
+  { sel_rmfile(&t->f); close(t->f.fd); DESTROY(t); }
 
 const tunnel_ops tun_bsd = {
   "bsd",
   t_init,
+  t_open,
   t_create,
   0,
   t_inject,