tinc-vpn.org Git - tinc/blob - src/uml_socket/device.c

   1 /*
   2     device.c -- UML network socket
   3     Copyright (C) 2002-2005 Ivo Timmermans,
   4                   2002-2009 Guus Sliepen <guus@tinc-vpn.org>
   5
   6     This program is free software; you can redistribute it and/or modify
   7     it under the terms of the GNU General Public License as published by
   8     the Free Software Foundation; either version 2 of the License, or
   9     (at your option) any later version.
  10
  11     This program is distributed in the hope that it will be useful,
  12     but WITHOUT ANY WARRANTY; without even the implied warranty of
  13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14     GNU General Public License for more details.
  15
  16     You should have received a copy of the GNU General Public License along
  17     with this program; if not, write to the Free Software Foundation, Inc.,
  18     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19 */
  20
  21 #include "system.h"
  22
  23 #include <sys/un.h>
  24
  25 #include "conf.h"
  26 #include "device.h"
  27 #include "net.h"
  28 #include "logger.h"
  29 #include "utils.h"
  30 #include "route.h"
  31 #include "xalloc.h"
  32
  33 int device_fd = -1;
  34 static int listen_fd = -1;
  35 static int request_fd = -1;
  36 static int data_fd = -1;
  37 static int write_fd = -1;
  38 static int state = 0;
  39 char *device = NULL;
  40 char *iface = NULL;
  41 static char *device_info;
  42
  43 extern char *identname;
  44 extern volatile bool running;
  45
  46 static uint64_t device_total_in = 0;
  47 static uint64_t device_total_out = 0;
  48
  49 enum request_type { REQ_NEW_CONTROL };
  50
  51 static struct request {
  52   uint32_t magic;
  53   uint32_t version;
  54   enum request_type type;
  55   struct sockaddr_un sock;
  56 } request;
  57
  58 static struct sockaddr_un data_sun;
  59
  60 bool setup_device(void) {
  61         struct sockaddr_un listen_sun;
  62         static const int one = 1;
  63         struct {
  64                 char zero;
  65                 int pid;
  66                 int usecs;
  67         } name;
  68         struct timeval tv;
  69
  70         if(!get_config_string(lookup_config(config_tree, "Device"), &device))
  71                 xasprintf(&device, LOCALSTATEDIR "/run/%s.umlsocket", identname);
  72
  73         get_config_string(lookup_config(config_tree, "Interface"), &iface);
  74
  75         device_info = "UML network socket";
  76
  77         if((write_fd = socket(PF_UNIX, SOCK_DGRAM, 0)) < 0) {
  78                 logger(LOG_ERR, "Could not open write %s: %s", device_info, strerror(errno));
  79                 running = false;
  80                 return false;
  81         }
  82
  83         setsockopt(write_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof one);
  84
  85         if(fcntl(write_fd, F_SETFL, O_NONBLOCK) < 0) {
  86                 logger(LOG_ERR, "System call `%s' failed: %s", "fcntl", strerror(errno));
  87                 running = false;
  88                 return false;
  89         }
  90
  91         if((data_fd = socket(PF_UNIX, SOCK_DGRAM, 0)) < 0) {
  92                 logger(LOG_ERR, "Could not open data %s: %s", device_info, strerror(errno));
  93                 running = false;
  94                 return false;
  95         }
  96
  97         setsockopt(data_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof one);
  98
  99         if(fcntl(data_fd, F_SETFL, O_NONBLOCK) < 0) {
 100                 logger(LOG_ERR, "System call `%s' failed: %s", "fcntl", strerror(errno));
 101                 running = false;
 102                 return false;
 103         }
 104
 105         name.zero = 0;
 106         name.pid = getpid();
 107         gettimeofday(&tv, NULL);
 108         name.usecs = tv.tv_usec;
 109         data_sun.sun_family = AF_UNIX;
 110         memcpy(&data_sun.sun_path, &name, sizeof name);
 111
 112         if(bind(data_fd, (struct sockaddr *)&data_sun, sizeof data_sun) < 0) {
 113                 logger(LOG_ERR, "Could not bind data %s: %s", device_info, strerror(errno));
 114                 running = false;
 115                 return false;
 116         }
 117
 118         if((listen_fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
 119                 logger(LOG_ERR, "Could not open %s: %s", device_info,
 120                            strerror(errno));
 121                 return false;
 122         }
 123
 124         setsockopt(listen_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof one);
 125
 126         if(fcntl(listen_fd, F_SETFL, O_NONBLOCK) < 0) {
 127                 logger(LOG_ERR, "System call `%s' failed: %s", "fcntl", strerror(errno));
 128                 return false;
 129         }
 130
 131         listen_sun.sun_family = AF_UNIX;
 132         strncpy(listen_sun.sun_path, device, sizeof listen_sun.sun_path);
 133         if(bind(listen_fd, (struct sockaddr *)&listen_sun, sizeof listen_sun) < 0) {
 134                 logger(LOG_ERR, "Could not bind %s to %s: %s", device_info, device, strerror(errno));
 135                 return false;
 136         }
 137
 138         if(listen(listen_fd, 1) < 0) {
 139                 logger(LOG_ERR, "Could not listen on %s %s: %s", device_info, device, strerror(errno));
 140                 return false;
 141         }
 142
 143         device_fd = listen_fd;
 144         state = 0;
 145
 146         logger(LOG_INFO, "%s is a %s", device, device_info);
 147
 148         if(routing_mode == RMODE_ROUTER)
 149                 overwrite_mac = true;
 150
 151         return true;
 152 }
 153
 154 void close_device(void) {
 155         if(listen_fd >= 0)
 156                 close(listen_fd);
 157
 158         if(request_fd >= 0)
 159                 close(request_fd);
 160
 161         if(data_fd >= 0)
 162                 close(data_fd);
 163
 164         if(write_fd >= 0)
 165                 close(write_fd);
 166
 167         unlink(device);
 168
 169         free(device);
 170         if(iface) free(iface);
 171 }
 172
 173 bool read_packet(vpn_packet_t *packet) {
 174         int lenin;
 175
 176         switch(state) {
 177                 case 0: {
 178                         struct sockaddr sa;
 179                         socklen_t salen = sizeof sa;
 180
 181                         request_fd = accept(listen_fd, &sa, &salen);
 182                         if(request_fd < 0) {
 183                                 logger(LOG_ERR, "Could not accept connection to %s %s: %s", device_info, device, strerror(errno));
 184                                 return false;
 185                         }
 186
 187                         if(fcntl(listen_fd, F_SETFL, O_NONBLOCK) < 0) {
 188                                 logger(LOG_ERR, "System call `%s' failed: %s", "fcntl", strerror(errno));
 189                                 running = false;
 190                                 return false;
 191                         }
 192
 193                         close(listen_fd);
 194                         listen_fd = -1;
 195                         device_fd = request_fd;
 196                         state = 1;
 197
 198                         return false;
 199                 }
 200
 201                 case 1: {
 202                         if((lenin = read(request_fd, &request, sizeof request)) != sizeof request) {
 203                                 logger(LOG_ERR, "Error while reading request from %s %s: %s", device_info,
 204                                            device, strerror(errno));
 205                                 running = false;
 206                                 return false;
 207                         }
 208
 209                         if(request.magic != 0xfeedface || request.version != 3 || request.type != REQ_NEW_CONTROL) {
 210                                 logger(LOG_ERR, "Unknown magic %x, version %d, request type %d from %s %s",
 211                                                 request.magic, request.version, request.type, device_info, device);
 212                                 running = false;
 213                                 return false;
 214                         }
 215
 216                         if(connect(write_fd, &request.sock, sizeof request.sock) < 0) {
 217                                 logger(LOG_ERR, "Could not bind write %s: %s", device_info, strerror(errno));
 218                                 running = false;
 219                                 return false;
 220                         }
 221
 222                         write(request_fd, &data_sun, sizeof data_sun);
 223                         device_fd = data_fd;
 224
 225                         logger(LOG_INFO, "Connection with UML established");
 226
 227                         state = 2;
 228                         return false;
 229                 }
 230
 231                 case 2: {
 232                         if((lenin = read(data_fd, packet->data, MTU)) <= 0) {
 233                                 logger(LOG_ERR, "Error while reading from %s %s: %s", device_info,
 234                                            device, strerror(errno));
 235                                 running = false;
 236                                 return false;
 237                         }
 238
 239                         packet->len = lenin;
 240
 241                         device_total_in += packet->len;
 242
 243                         ifdebug(TRAFFIC) logger(LOG_DEBUG, "Read packet of %d bytes from %s", packet->len,
 244                                            device_info);
 245
 246                         return true;
 247                 }
 248
 249                 default:
 250                         logger(LOG_ERR, "Invalid value for state variable in " __FILE__);
 251                         abort();
 252         }
 253 }
 254
 255 bool write_packet(vpn_packet_t *packet) {
 256         if(state != 2) {
 257                 ifdebug(TRAFFIC) logger(LOG_DEBUG, "Dropping packet of %d bytes to %s: not connected to UML yet",
 258                                 packet->len, device_info);
 259                 return false;
 260         }
 261
 262         ifdebug(TRAFFIC) logger(LOG_DEBUG, "Writing packet of %d bytes to %s",
 263                            packet->len, device_info);
 264
 265         if(write(write_fd, packet->data, packet->len) < 0) {
 266                 if(errno != EINTR && errno != EAGAIN) {
 267                         logger(LOG_ERR, "Can't write to %s %s: %s", device_info, device, strerror(errno));
 268                         running = false;
 269                 }
 270
 271                 return false;
 272         }
 273
 274         device_total_out += packet->len;
 275
 276         return true;
 277 }
 278
 279 void dump_device_stats(void) {
 280         logger(LOG_DEBUG, "Statistics for %s %s:", device_info, device);
 281         logger(LOG_DEBUG, " total bytes in:  %10"PRIu64, device_total_in);
 282         logger(LOG_DEBUG, " total bytes out: %10"PRIu64, device_total_out);
 283 }