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
  32 int device_fd = -1;
  33 static int listen_fd = -1;
  34 static int request_fd = -1;
  35 static int data_fd = -1;
  36 static int write_fd = -1;
  37 static int state = 0;
  38 char *device = NULL;
  39 char *iface = NULL;
  40 static char *device_info;
  41
  42 extern char *identname;
  43 extern bool running;
  44
  45 static uint64_t device_total_in = 0;
  46 static uint64_t device_total_out = 0;
  47
  48 enum request_type { REQ_NEW_CONTROL };
  49
  50 static struct request {
  51   uint32_t magic;
  52   uint32_t version;
  53   enum request_type type;
  54   struct sockaddr_un sock;
  55 } request;
  56
  57 static struct sockaddr_un data_sun;
  58
  59 bool setup_device(void) {
  60         struct sockaddr_un listen_sun;
  61         static const int one = 1;
  62         struct {
  63                 char zero;
  64                 int pid;
  65                 int usecs;
  66         } name;
  67         struct timeval tv;
  68
  69         if(!get_config_string(lookup_config(config_tree, "Device"), &device))
  70                 xasprintf(&device, LOCALSTATEDIR "/run/%s.umlsocket", identname);
  71
  72         get_config_string(lookup_config(config_tree, "Interface"), &iface);
  73
  74         device_info = "UML network socket";
  75
  76         if((write_fd = socket(PF_UNIX, SOCK_DGRAM, 0)) < 0) {
  77                 logger(LOG_ERR, "Could not open write %s: %s", device_info, strerror(errno));
  78                 running = false;
  79                 return false;
  80         }
  81
  82         setsockopt(write_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof one);
  83
  84         if(fcntl(write_fd, F_SETFL, O_NONBLOCK) < 0) {
  85                 logger(LOG_ERR, "System call `%s' failed: %s", "fcntl", strerror(errno));
  86                 running = false;
  87                 return false;
  88         }
  89
  90         if((data_fd = socket(PF_UNIX, SOCK_DGRAM, 0)) < 0) {
  91                 logger(LOG_ERR, "Could not open data %s: %s", device_info, strerror(errno));
  92                 running = false;
  93                 return false;
  94         }
  95
  96         setsockopt(data_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof one);
  97
  98         if(fcntl(data_fd, F_SETFL, O_NONBLOCK) < 0) {
  99                 logger(LOG_ERR, "System call `%s' failed: %s", "fcntl", strerror(errno));
 100                 running = false;
 101                 return false;
 102         }
 103
 104         name.zero = 0;
 105         name.pid = getpid();
 106         gettimeofday(&tv, NULL);
 107         name.usecs = tv.tv_usec;
 108         data_sun.sun_family = AF_UNIX;
 109         memcpy(&data_sun.sun_path, &name, sizeof name);
 110
 111         if(bind(data_fd, (struct sockaddr *)&data_sun, sizeof data_sun) < 0) {
 112                 logger(LOG_ERR, "Could not bind data %s: %s", device_info, strerror(errno));
 113                 running = false;
 114                 return false;
 115         }
 116
 117         if((listen_fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
 118                 logger(LOG_ERR, "Could not open %s: %s", device_info,
 119                            strerror(errno));
 120                 return false;
 121         }
 122
 123         setsockopt(listen_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof one);
 124
 125         if(fcntl(listen_fd, F_SETFL, O_NONBLOCK) < 0) {
 126                 logger(LOG_ERR, "System call `%s' failed: %s", "fcntl", strerror(errno));
 127                 return false;
 128         }
 129
 130         listen_sun.sun_family = AF_UNIX;
 131         strncpy(listen_sun.sun_path, device, sizeof listen_sun.sun_path);
 132         if(bind(listen_fd, (struct sockaddr *)&listen_sun, sizeof listen_sun) < 0) {
 133                 logger(LOG_ERR, "Could not bind %s to %s: %s", device_info, device, strerror(errno));
 134                 return false;
 135         }
 136
 137         if(listen(listen_fd, 1) < 0) {
 138                 logger(LOG_ERR, "Could not listen on %s %s: %s", device_info, device, strerror(errno));
 139                 return false;
 140         }
 141
 142         device_fd = listen_fd;
 143         state = 0;
 144
 145         logger(LOG_INFO, "%s is a %s", device, device_info);
 146
 147         if(routing_mode == RMODE_ROUTER)
 148                 overwrite_mac = true;
 149
 150         return true;
 151 }
 152
 153 void close_device(void) {
 154         if(listen_fd >= 0)
 155                 close(listen_fd);
 156
 157         if(request_fd >= 0)
 158                 close(request_fd);
 159
 160         if(data_fd >= 0)
 161                 close(data_fd);
 162
 163         if(write_fd >= 0)
 164                 close(write_fd);
 165
 166         unlink(device);
 167
 168         free(device);
 169         if(iface) free(iface);
 170 }
 171
 172 bool read_packet(vpn_packet_t *packet) {
 173         int inlen;
 174
 175         switch(state) {
 176                 case 0: {
 177                         struct sockaddr sa;
 178                         int salen = sizeof sa;
 179
 180                         request_fd = accept(listen_fd, &sa, &salen);
 181                         if(request_fd < 0) {
 182                                 logger(LOG_ERR, "Could not accept connection to %s %s: %s", device_info, device, strerror(errno));
 183                                 return false;
 184                         }
 185
 186                         if(fcntl(listen_fd, F_SETFL, O_NONBLOCK) < 0) {
 187                                 logger(LOG_ERR, "System call `%s' failed: %s", "fcntl", strerror(errno));
 188                                 running = false;
 189                                 return false;
 190                         }
 191
 192                         close(listen_fd);
 193                         listen_fd = -1;
 194                         device_fd = request_fd;
 195                         state = 1;
 196
 197                         return false;
 198                 }
 199
 200                 case 1: {
 201                         if((inlen = read(request_fd, &request, sizeof request)) != sizeof request) {
 202                                 logger(LOG_ERR, "Error while reading request from %s %s: %s", device_info,
 203                                            device, strerror(errno));
 204                                 running = false;
 205                                 return false;
 206                         }
 207
 208                         if(request.magic != 0xfeedface || request.version != 3 || request.type != REQ_NEW_CONTROL) {
 209                                 logger(LOG_ERR, "Unknown magic %x, version %d, request type %d from %s %s",
 210                                                 request.magic, request.version, request.type, device_info, device);
 211                                 running = false;
 212                                 return false;
 213                         }
 214
 215                         if(connect(write_fd, &request.sock, sizeof request.sock) < 0) {
 216                                 logger(LOG_ERR, "Could not bind write %s: %s", device_info, strerror(errno));
 217                                 running = false;
 218                                 return false;
 219                         }
 220
 221                         write(request_fd, &data_sun, sizeof data_sun);
 222                         device_fd = data_fd;
 223
 224                         logger(LOG_INFO, "Connection with UML established");
 225
 226                         state = 2;
 227                         return false;
 228                 }
 229
 230                 case 2: {
 231                         if((inlen = read(data_fd, packet->data, MTU)) <= 0) {
 232                                 logger(LOG_ERR, "Error while reading from %s %s: %s", device_info,
 233                                            device, strerror(errno));
 234                                 running = false;
 235                                 return false;
 236                         }
 237
 238                         packet->len = inlen;
 239
 240                         device_total_in += packet->len;
 241
 242                         ifdebug(TRAFFIC) logger(LOG_DEBUG, "Read packet of %d bytes from %s", packet->len,
 243                                            device_info);
 244
 245                         return true;
 246                 }
 247         }
 248 }
 249
 250 bool write_packet(vpn_packet_t *packet) {
 251         if(state != 2) {
 252                 ifdebug(TRAFFIC) logger(LOG_DEBUG, "Dropping packet of %d bytes to %s: not connected to UML yet",
 253                                 packet->len, device_info);
 254                 return false;
 255         }
 256
 257         ifdebug(TRAFFIC) logger(LOG_DEBUG, "Writing packet of %d bytes to %s",
 258                            packet->len, device_info);
 259
 260         if(write(write_fd, packet->data, packet->len) < 0) {
 261                 if(errno != EINTR && errno != EAGAIN) {
 262                         logger(LOG_ERR, "Can't write to %s %s: %s", device_info, device, strerror(errno));
 263                         running = false;
 264                 }
 265
 266                 return false;
 267         }
 268
 269         device_total_out += packet->len;
 270
 271         return true;
 272 }
 273
 274 void dump_device_stats(void) {
 275         logger(LOG_DEBUG, "Statistics for %s %s:", device_info, device);
 276         logger(LOG_DEBUG, " total bytes in:  %10"PRIu64, device_total_in);
 277         logger(LOG_DEBUG, " total bytes out: %10"PRIu64, device_total_out);
 278 }