xio-tun.c

   1 /* source: xio-tun.c */
   2 /* Copyright Gerhard Rieger and contributors (see file CHANGES) */
   3 /* Published under the GNU General Public License V.2, see file COPYING */
   4
   5 /* this file contains the source for opening addresses of tun/tap type */
   6
   7 #include "xiosysincludes.h"
   8 #if WITH_TUN
   9 #include "xioopen.h"
  10
  11 #include "xio-named.h"
  12 #include "xio-socket.h"
  13 #include "xio-ip.h"
  14 #include "xio-interface.h"
  15
  16 #include "xio-tun.h"
  17
  18
  19 static int xioopen_tun(int argc, const char *argv[], struct opt *opts, int xioflags, xiofile_t *xfd, const struct addrdesc *addrdesc);
  20
  21 /****** TUN options ******/
  22 const struct optdesc opt_tun_device    = { "tun-device",     NULL,      OPT_TUN_DEVICE,      GROUP_TUN,       PH_OPEN, TYPE_FILENAME, OFUNC_SPEC };
  23 const struct optdesc opt_tun_name      = { "tun-name",       NULL,      OPT_TUN_NAME,        GROUP_INTERFACE, PH_FD,   TYPE_STRING,   OFUNC_SPEC };
  24 const struct optdesc opt_tun_type      = { "tun-type",       NULL,      OPT_TUN_TYPE,        GROUP_INTERFACE, PH_FD,   TYPE_STRING,   OFUNC_SPEC };
  25 const struct optdesc opt_iff_no_pi     = { "iff-no-pi",      "no-pi",   OPT_IFF_NO_PI,       GROUP_TUN,       PH_FD,   TYPE_BOOL,     OFUNC_SPEC };
  26
  27 /****** TUN addresses ******/
  28 const struct addrdesc xioaddr_tun    = { "TUN",    3, xioopen_tun, GROUP_FD|GROUP_CHR|GROUP_OPEN|GROUP_TUN, 0, 0, 0 HELP("[:<ip-addr>/<bits>]") };
  29 /* "if-name"=tun3
  30 // "route"=address/netmask
  31 // "ip6-route"=address/netmask
  32 // "iff-broadcast"
  33 // "iff-debug"
  34 // "iff-promisc"
  35 // see .../linux/if.h
  36 */
  37
  38
  39 #if LATER
  40 /* sub options for route option */
  41 #define IFOPT_ROUTE 1
  42 static const struct optdesc opt_route_tos = { "route", NULL, IFOPT_ROUTE, };
  43 static const struct optname xio_route_options[] = {
  44    {"tos", &xio_route_tos }
  45 } ;
  46 #endif
  47
  48 static int xioopen_tun(
  49         int argc,
  50         const char *argv[],
  51         struct opt *opts,
  52         int xioflags,
  53         xiofile_t *xfd,
  54         const struct addrdesc *addrdesc)
  55 {
  56    struct single *sfd = &xfd->stream;
  57    char *tundevice = NULL;
  58    char *tunname = NULL, *tuntype = NULL;
  59    int pf = /*! PF_UNSPEC*/ PF_INET;
  60    struct xiorange network;
  61    bool no_pi = false;
  62    const char *namedargv[] = { "tun", NULL, NULL };
  63    int rw = (xioflags & XIO_ACCMODE);
  64    bool exists;
  65    struct ifreq ifr;
  66    int sockfd;
  67    char *ifaddr;
  68    int result;
  69
  70    if (argc > 2 || argc < 0) {
  71 #if WITH_HELP
  72       Error3("%s: wrong number of parameters (%d instead of 0 or 1); usage: %s",
  73              argv[0], argc-1, addrdesc->syntax);
  74 #else
  75       Error2("%s: wrong number of parameters (%d instead of 0 or 1)",
  76              argv[0], argc-1);
  77 #endif
  78    }
  79
  80    if (retropt_string(opts, OPT_TUN_DEVICE, &tundevice) != 0) {
  81       tundevice = strdup("/dev/net/tun");
  82    }
  83
  84    /*! socket option here? */
  85    retropt_socket_pf(opts, &pf);
  86
  87    namedargv[1] = tundevice;
  88    /* open the tun cloning device */
  89    if ((result = _xioopen_named_early(2, namedargv, xfd, addrdesc->groups,
  90                                       &exists, opts, addrdesc->syntax)) < 0) {
  91       return result;
  92    }
  93
  94    /*========================= the tunnel interface =========================*/
  95    Notice("creating tunnel network interface");
  96    applyopts_optgroup(&xfd->stream, -1, opts, GROUP_PROCESS);
  97    if ((result = _xioopen_open(tundevice, rw, opts)) < 0)
  98       return result;
  99    sfd->fd = result;
 100
 101    /* prepare configuration of the new network interface */
 102    memset(&ifr, 0, sizeof(ifr));
 103
 104    if (retropt_string(opts, OPT_TUN_NAME, &tunname) == 0) {
 105       strncpy(ifr.ifr_name, tunname, IFNAMSIZ); /* ok */
 106       free(tunname);
 107    } else {
 108       ifr.ifr_name[0] = '\0';
 109    }
 110
 111    ifr.ifr_flags = IFF_TUN;
 112    if (retropt_string(opts, OPT_TUN_TYPE, &tuntype) == 0) {
 113       if (!strcmp(tuntype, "tap")) {
 114          ifr.ifr_flags = IFF_TAP;
 115       } else if (strcmp(tuntype, "tun")) {
 116          Error1("unknown tun-type \"%s\"", tuntype);
 117       }
 118    }
 119
 120    if (retropt_bool(opts, OPT_IFF_NO_PI, &no_pi) == 0) {
 121       if (no_pi) {
 122          ifr.ifr_flags |= IFF_NO_PI;
 123 #if 0 /* not neccessary for now */
 124       } else {
 125          ifr.ifr_flags &= ~IFF_NO_PI;
 126 #endif
 127       }
 128    }
 129
 130    if (Ioctl(sfd->fd, TUNSETIFF, &ifr) < 0) {
 131       Error3("ioctl(%d, TUNSETIFF, {\"%s\"}: %s",
 132              sfd->fd, ifr.ifr_name, strerror(errno));
 133       Close(sfd->fd);
 134    }
 135    Notice1("TUN: new device \"%s\"", ifr.ifr_name);
 136
 137    /*===================== setting interface properties =====================*/
 138
 139    /* we seem to need a socket for manipulating the interface */
 140    if ((sockfd = Socket(PF_INET, SOCK_DGRAM, 0)) < 0) {
 141       Error1("socket(PF_INET, SOCK_DGRAM, 0): %s", strerror(errno));
 142       sockfd = sfd->fd; /* desparate fallback attempt */
 143    }
 144
 145    /*--------------------- setting interface address and netmask ------------*/
 146    if (argc == 2) {
 147        if ((ifaddr = strdup(argv[1])) == NULL) {
 148           Error1("strdup(\"%s\"): out of memory", argv[1]);
 149           return STAT_RETRYLATER;
 150        }
 151        if ((result = xioparsenetwork(ifaddr, pf, &network,
 152                                      sfd->para.socket.ip.ai_flags))
 153            != STAT_OK) {
 154           /*! recover */
 155           return result;
 156        }
 157        socket_init(pf, (union sockaddr_union *)&ifr.ifr_addr);
 158        ((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr =
 159           network.netaddr.ip4.sin_addr;
 160        if (Ioctl(sockfd, SIOCSIFADDR, &ifr) < 0) {
 161           Error4("ioctl(%d, SIOCSIFADDR, {\"%s\", \"%s\"}: %s",
 162              sockfd, ifr.ifr_name, ifaddr, strerror(errno));
 163        }
 164        ((struct sockaddr_in *)&ifr.ifr_netmask)->sin_addr =
 165           network.netmask.ip4.sin_addr;
 166        if (Ioctl(sockfd, SIOCSIFNETMASK, &ifr) < 0) {
 167           Error4("ioctl(%d, SIOCSIFNETMASK, {\"0x%08u\", \"%s\"}, %s",
 168              sockfd, ((struct sockaddr_in *)&ifr.ifr_netmask)->sin_addr.s_addr,
 169              ifaddr, strerror(errno));
 170        }
 171        free(ifaddr);
 172    }
 173    /*--------------------- setting interface flags --------------------------*/
 174    applyopts_single(sfd, opts, PH_FD);
 175
 176    _xiointerface_apply_iff(sockfd, ifr.ifr_name, sfd->para.interface.iff_opts);
 177    if (_interface_retrieve_vlan(&xfd->stream, opts) < 0)
 178       return STAT_NORETRY;
 179
 180    applyopts(sfd, -1, opts, PH_FD);
 181    applyopts_cloexec(sfd->fd, opts);
 182
 183    applyopts_fchown(sfd->fd, opts);
 184
 185    if ((result = _xio_openlate(sfd, opts)) < 0)
 186       return result;
 187
 188    return 0;
 189 }
 190
 191 #endif /* WITH_TUN */