- reyk@cvs.openbsd.org 2005/12/08 18:34:11

     [auth-options.c includes.h misc.c misc.h readconf.c servconf.c]
     [serverloop.c ssh.c ssh_config.5 sshd_config.5 configure.ac]
     two changes to the new ssh tunnel support. this breaks compatibility
     with the initial commit but is required for a portable approach.
     - make the tunnel id u_int and platform friendly, use predefined types.
     - support configuration of layer 2 (ethernet) or layer 3
     (point-to-point, default) modes. configuration is done using the
     Tunnel (yes|point-to-point|ethernet|no) option is ssh_config(5) and
     restricted by the PermitTunnel (yes|point-to-point|ethernet|no) option
     in sshd_config(5).
     ok djm@, man page bits by jmc@

1 files changed, 54 insertions, 21 deletions

diff --git a/misc.c b/misc.c
index 9b23e2c37..4f41332f9 100644
--- a/misc.c
+++ b/misc.c
@@ -24,7 +24,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: misc.c,v 1.36 2005/12/06 22:38:27 reyk Exp $");
+RCSID("$OpenBSD: misc.c,v 1.37 2005/12/08 18:34:11 reyk Exp $");
 
 #include "misc.h"
 #include "log.h"
@@ -202,7 +202,7 @@ a2tun(const char *s, int *remote)
         int tun;
 
         if (remote != NULL) {
-                *remote = -1;
+                *remote = SSH_TUNID_ANY;
                 sp = xstrdup(s);
                 if ((ep = strchr(sp, ':')) == NULL) {
                         xfree(sp);
@@ -212,15 +212,15 @@ a2tun(const char *s, int *remote)
                 *remote = a2tun(ep, NULL);
                 tun = a2tun(sp, NULL);
                 xfree(sp);
-                return (tun);
+                return (*remote == SSH_TUNID_ERR ? *remote : tun);
         }
 
         if (strcasecmp(s, "any") == 0)
-                return (-1);
+                return (SSH_TUNID_ANY);
 
-        tun = strtonum(s, 0, INT_MAX, &errstr);
-        if (errstr != NULL || tun < -1)
-                return (-2);
+        tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr);
+        if (errstr != NULL)
+                return (SSH_TUNID_ERR);
 
         return (tun);
 }
@@ -539,27 +539,60 @@ read_keyfile_line(FILE *f, const char *filename, char *buf, size_t bufsz,
 }
 
 int
-tun_open(int tun)
+tun_open(int tun, int mode)
 {
+        struct ifreq ifr;
         char name[100];
-        int i, fd;
+        int fd = -1, sock;
 
-        if (tun > -1) {
+        /* Open the tunnel device */
+        if (tun <= SSH_TUNID_MAX) {
                 snprintf(name, sizeof(name), "/dev/tun%d", tun);
-                if ((fd = open(name, O_RDWR)) >= 0)  {
-                        debug("%s: %s: %d", __func__, name, fd);
-                        return (fd);
+                fd = open(name, O_RDWR);
+        } else if (tun == SSH_TUNID_ANY) {
+                for (tun = 100; tun >= 0; tun--) {
+                        snprintf(name, sizeof(name), "/dev/tun%d", tun);
+                        if ((fd = open(name, O_RDWR)) >= 0)
+                                break;
                 }
         } else {
-                for (i = 100; i >= 0; i--) {
-                        snprintf(name, sizeof(name), "/dev/tun%d", i);
-                        if ((fd = open(name, O_RDWR)) >= 0)  {
-                                debug("%s: %s: %d", __func__, name, fd);
-                                return (fd);
-                        }
-                }
+                debug("%s: invalid tunnel %u\n", __func__, tun);
+                return (-1);
+        }
+
+        if (fd < 0) {
+                debug("%s: %s open failed: %s", __func__, name, strerror(errno));
+                return (-1);
+        }
+
+        debug("%s: %s mode %d fd %d", __func__, name, mode, fd);
+
+        /* Set the tunnel device operation mode */
+        snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "tun%d", tun);
+        if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
+                goto failed;
+
+        if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1)
+                goto failed;
+        if (mode == SSH_TUNMODE_ETHERNET) {
+                ifr.ifr_flags |= IFF_LINK0;
+                if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
+                        goto failed;
         }
-        debug("%s: %s failed: %s", __func__, name, strerror(errno));
+        ifr.ifr_flags |= IFF_UP;
+        if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
+                goto failed;
+
+        close(sock);
+        return (fd);
+
+ failed:
+        if (fd >= 0)
+                close(fd);
+        if (sock >= 0)
+                close(sock);
+        debug("%s: failed to set %s mode %d: %s", __func__, name,
+            mode, strerror(errno));
         return (-1);
 }