Re: bin/39233: OpenSSH fails to initialize tun(4) tunnels correctly

[Taylor R Campbell <campbell%mumble.net@localhost>]

The following reply was made to PR bin/39233; it has been noted by GNATS.

From: Taylor R Campbell <campbell%mumble.net@localhost>
To: cube%cubidou.net@localhost
Cc: gnats-bugs%NetBSD.org@localhost
Subject: Re: bin/39233: OpenSSH fails to initialize tun(4) tunnels correctly
Date: Mon, 28 Jul 2008 16:06:38 -0400

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 ..actually attached this time.
 
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 Content-Transfer-Encoding: quoted-printable
 Content-Disposition: attachment; filename="ssh-tun.patch"
 
 Index: misc.c
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 RCS file: /cvsroot/src/crypto/dist/ssh/misc.c,v
 retrieving revision 1.21
 diff -u -r1.21 misc.c
 --- misc.c     6 Apr 2008 23:38:19 -0000       1.21
 +++ misc.c     28 Jul 2008 17:41:32 -0000
 @@ -35,6 +35,9 @@
  #include <net/if.h>
  #include <netinet/in.h>
  #include <netinet/tcp.h>
 +#ifdef __NetBSD__
 +# include <net/if_tun.h>
 +#endif
 =20
  #include <errno.h>
  #include <fcntl.h>
 @@ -636,20 +639,62 @@
        return -1;
  }
 =20
 +#if defined(__NetBSD__)
 +
 +# define TUN_POINTOPOINT_DEVICE "tun"
 +# define TUN_ETHERNET_DEVICE "tap"
 +
 +static int
 +tun_set_if_mode(int tun, int mode, int fd, int sock, struct ifreq *ifr)
 +{
 +      if (mode =3D=3D SSH_TUNMODE_POINTOPOINT) {
 +              int one =3D 1;
 +              return ioctl(fd, TUNSIFHEAD, &one);
 +      }
 +      return 0;
 +}
 +
 +#elif defined(__OpenBSD__) || defined(__FreeBSD__)
 +
 +# define TUN_POINTOPOINT_DEVICE "tun"
 +# define TUN_ETHERNET_DEVICE "tun"
 +
 +static int
 +tun_set_if_mode(int tun, int mode, int fd, int sock, struct ifreq *ifr)
 +{
 +      ifr->ifr_flags &=3D ~IFF_IP;
 +      if (mode =3D=3D SSH_TUNMODE_ETHERNET)
 +              ifr->ifr_flags |=3D IFF_LINK0;
 +      else
 +              ifr->ifr_flags &=3D ~IFF_LINK0;
 +      return ioctl(sock, SIOCSIFFLAGS, ifr);
 +}
 +
 +#endif
 +
  int
  tun_open(int tun, int mode)
  {
        struct ifreq ifr;
 -      char name[100];
 +      char name[100], *device;
        int fd =3D -1, sock;
 =20
 +      if (mode =3D=3D SSH_TUNMODE_POINTOPOINT)
 +              device =3D TUN_POINTOPOINT_DEVICE;
 +      else if (mode =3D=3D SSH_TUNMODE_ETHERNET)
 +              device =3D TUN_ETHERNET_DEVICE;
 +      else {
 +              debug("%s: invalid tunnel mode %d", __func__, tun);
 +              return (-1);
 +      }
 +
        /* Open the tunnel device */
        if (tun <=3D SSH_TUNID_MAX) {
 -              snprintf(name, sizeof(name), "/dev/tun%d", tun);
 +              snprintf(name, sizeof(name), "/dev/%s%d", device, tun);
                fd =3D open(name, O_RDWR);
        } else if (tun =3D=3D SSH_TUNID_ANY) {
                for (tun =3D 100; tun >=3D 0; tun--) {
 -                      snprintf(name, sizeof(name), "/dev/tun%d", tun);
 +                      snprintf(name, sizeof(name), "/dev/%s%d", device, tun);
                        if ((fd =3D open(name, O_RDWR)) >=3D 0)
                                break;
                }
 @@ -666,7 +711,7 @@
        debug("%s: %s mode %d fd %d", __func__, name, mode, fd);
 =20
        /* Set the tunnel device operation mode */
 -      snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "tun%d", tun);
 +      snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", device, tun);
        if ((sock =3D socket(PF_UNIX, SOCK_STREAM, 0)) =3D=3D -1)
                goto failed;
 =20
 @@ -674,12 +719,7 @@
                goto failed;
 =20
        /* Set interface mode */
 -      ifr.ifr_flags &=3D ~IFF_UP;
 -      if (mode =3D=3D SSH_TUNMODE_ETHERNET)
 -              ifr.ifr_flags |=3D IFF_LINK0;
 -      else
 -              ifr.ifr_flags &=3D ~IFF_LINK0;
 -      if (ioctl(sock, SIOCSIFFLAGS, &ifr) =3D=3D -1)
 +      if (tun_set_if_mode(tun, mode, fd, sock, &ifr) =3D=3D -1)
                goto failed;
 =20
        /* Bring interface up */
 
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