lib/tun.h

   1 /*
   2  * TUN interface functions.
   3  * Copyright (C) 2002, 2003 Mondru AB.
   4  * Copyright (C) 2017 by Harald Welte <laforge@gnumonks.org>
   5  *
   6  * The contents of this file may be used under the terms of the GNU
   7  * General Public License Version 2, provided that the above copyright
   8  * notice and this permission notice is included in all copies or
   9  * substantial portions of the software.
  10  *
  11  */
  12
  13 #ifndef _TUN_H
  14 #define _TUN_H
  15
  16 #include <net/if.h>
  17
  18 #include "../lib/in46_addr.h"
  19
  20 #define PACKET_MAX      8196    /* Maximum packet size we receive */
  21 #define TUN_SCRIPTSIZE   256
  22 #define TUN_ADDRSIZE     128
  23 #define TUN_NLBUFSIZE   1024
  24
  25 #include "config.h"
  26 #ifndef HAVE_IPHDR
  27 struct iphdr
  28   {
  29 #if __BYTE_ORDER == __LITTLE_ENDIAN
  30     unsigned int ihl:4;
  31     unsigned int version:4;
  32 #elif __BYTE_ORDER == __BIG_ENDIAN
  33     unsigned int version:4;
  34     unsigned int ihl:4;
  35 #else
  36 # error "Please fix <bits/endian.h>"
  37 #endif
  38     u_int8_t tos;
  39     u_int16_t tot_len;
  40     u_int16_t id;
  41     u_int16_t frag_off;
  42     u_int8_t ttl;
  43     u_int8_t protocol;
  44     u_int16_t check;
  45     u_int32_t saddr;
  46     u_int32_t daddr;
  47     /*The options start here. */
  48   };
  49 #endif /* !HAVE_IPHDR */
  50
  51 /* ***********************************************************
  52  * Information storage for each tun instance
  53  *************************************************************/
  54
  55 struct tun_t {
  56         int fd;                 /* File descriptor to tun interface */
  57         struct in_addr addr;
  58         struct in_addr dstaddr;
  59         struct in_addr netmask;
  60         int addrs;              /* Number of allocated IP addresses */
  61         int routes;             /* One if we allocated an automatic route */
  62         char devname[IFNAMSIZ]; /* Name of the tun device */
  63         int (*cb_ind) (struct tun_t * tun, void *pack, unsigned len);
  64         /* to be used by libgtp callers/users (to attach their own private state) */
  65         void *priv;
  66 };
  67
  68 extern int tun_new(struct tun_t **tun);
  69 extern int tun_free(struct tun_t *tun);
  70 extern int tun_decaps(struct tun_t *this);
  71 extern int tun_encaps(struct tun_t *tun, void *pack, unsigned len);
  72
  73 extern int tun_addaddr(struct tun_t *this, struct in_addr *addr,
  74                        struct in_addr *dstaddr, struct in_addr *netmask);
  75
  76 extern int tun_setaddr(struct tun_t *this, struct in46_addr *our_adr,
  77                        struct in46_addr *his_adr, size_t prefixlen);
  78
  79 int tun_addroute(struct tun_t *this, struct in_addr *dst,
  80                  struct in_addr *gateway, struct in_addr *mask);
  81
  82 extern int tun_set_cb_ind(struct tun_t *this,
  83                           int (*cb_ind) (struct tun_t * tun, void *pack,
  84                                          unsigned len));
  85
  86 extern int tun_runscript(struct tun_t *tun, char *script);
  87
  88 #endif /* !_TUN_H */