server/bulkcrypto.c (gencomp_chal): Remove pointless extra `tagsz' member.

[tripe] / server / tun-std.c

/* -*-c-*-
 *
 * Tunnel interface for Linux-tun-shaped arrangements
 *
 * (c) 2003 Straylight/Edgeware
 */

/*----- Licensing notice --------------------------------------------------*
 *
 * This file is part of Trivial IP Encryption (TrIPE).
 *
 * TrIPE is free software: you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 3 of the License, or (at your
 * option) any later version.
 *
 * TrIPE is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with TrIPE.  If not, see <https://www.gnu.org/licenses/>.
 */

/*----- Header files ------------------------------------------------------*/

#define TUN_INTERNALS

#include "tripe.h"

/*----- Main code ---------------------------------------------------------*/

#if defined(TUN_LINUX) || defined(TUN_BSD) || defined(TUN_UNET)

struct tunnel {
  const tunnel_ops *ops;		/* Pointer to operations */
  sel_file f;				/* Selector for TUN/TAP device */
  struct peer *p;			/* Pointer to my peer */
};

/* --- @t_read@ --- *
 *
 * Arguments:	@int fd@ = file descriptor to read
 *		@unsigned mode@ = what's happened
 *		@void *v@ = pointer to tunnel block
 *
 * Returns:	---
 *
 * Use:		Reads data from the tunnel.
 */

static void t_read(int fd, unsigned mode, void *v)
{
  tunnel *t = v;
  ssize_t n;
  buf b;

  n = read(fd, buf_i, sizeof(buf_i));
  if (n < 0) {
    a_warn("TUN", "%s", p_ifname(t->p), "%s", t->ops->name,
	   "read-error", "?ERRNO", A_END);
    return;
  }
  IF_TRACING(T_TUNNEL, {
    trace(T_TUNNEL, "tun-%s: packet arrived", t->ops->name);
    trace_block(T_PACKET, "tunnel: packet contents", buf_i, n);
  })
  buf_init(&b, buf_i, n);
  p_tun(t->p, &b);
}

/* --- @t_init@ --- *
 *
 * Arguments:	---
 *
 * Returns:	---
 *
 * Use:		Initializes the tunneling system.  Maybe this will require
 *		opening file descriptors or something.
 */

static void t_init(void) { return; }

/* --- @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, const tunnel_ops *ops)
{
  tunnel *t;

  fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
  t = CREATE(tunnel);
  t->ops = ops;
  t->p = p;
  sel_initfile(&sel, &t->f, fd, SEL_READ, t_read, t);
  sel_addfile(&t->f);
  return (t);
}

/* --- @t_inject@ --- *
 *
 * Arguments:	@tunnel *t@ = pointer to tunnel block
 *		@buf *b@ = buffer to send
 *
 * Returns:	---
 *
 * Use:		Injects a packet into the local network stack.
 */

static void t_inject(tunnel *t, buf *b)
{
  IF_TRACING(T_TUNNEL, {
    trace(T_TUNNEL, "tun-%s: inject decrypted packet", t->ops->name);
    trace_block(T_PACKET, "tunnel: packet contents", BBASE(b), BLEN(b));
  })
  DISCARD(write(t->f.fd, BBASE(b), BLEN(b)));
}

/* --- @t_destroy@ --- *
 *
 * Arguments:	@tunnel *t@ = pointer to tunnel block
 *
 * Returns:	---
 *
 * Use:		Destroys a tunnel.
 */

static void t_destroy(tunnel *t)
  { sel_rmfile(&t->f); close(t->f.fd); DESTROY(t); }

#define DEFOPS(name)							\
									\
static tunnel *t_create_##name(peer *p, int fd, char **ifn);		\
									\
const tunnel_ops tun_##name = {						\
  #name, TUNF_PRIVOPEN,							\
  t_init, t_create_##name, 0, t_inject, t_destroy			\
};									\
									\
static tunnel *t_create_##name(peer *p, int fd, char **ifn)		\
  { return t_create(p, fd, ifn, &tun_##name); }

#ifdef TUN_LINUX
  DEFOPS(linux)
#endif

#ifdef TUN_BSD
  DEFOPS(bsd)
#endif

#ifdef TUN_UNET
  DEFOPS(unet)
#endif

#endif

/*----- That's all, folks -------------------------------------------------*/