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 "net.h"
  27 #include "logger.h"
  28 #include "utils.h"
  29 #include "route.h"
  30
  31 int device_fd = -1;
  32 static int listen_fd = -1;
  33 static int request_fd = -1;
  34 static int data_fd = -1;
  35 static int write_fd = -1;
  36 static int state = 0;
  37 char *device = NULL;
  38 char *iface = NULL;
  39 static char *device_info;
  40
  41 extern char *identname;
  42 extern bool running;
  43
  44 static uint64_t device_total_in = 0;
  45 static uint64_t device_total_out = 0;
  46
  47 enum request_type { REQ_NEW_CONTROL };
  48
  49 static struct request {
  50   uint32_t magic;
  51   uint32_t version;
  52   enum request_type type;
  53   struct sockaddr_un sock;
  54 } request;
  55
  56 static struct sockaddr_un data_sun;
  57
  58 bool setup_device(void) {
  59         struct sockaddr_un listen_sun;
  60         static const int one = 1;
  61         struct {
  62                 char zero;
  63                 int pid;
  64                 int usecs;
  65         } name;
  66         struct timeval tv;
  67
  68         if(!get_config_string(lookup_config(config_tree, "Device"), &device))
  69                 xasprintf(&device, LOCALSTATEDIR "/run/%s.umlsocket", identname);
  70
  71         get_config_string(lookup_config(config_tree, "Interface"), &iface);
  72
  73         device_info = "UML network socket";
  74
  75         if((write_fd = socket(PF_UNIX, SOCK_DGRAM, 0)) < 0) {
  76                 logger(LOG_ERR, "Could not open write %s: %s", device_info, strerror(errno));
  77                 running = false;
  78                 return false;
  79         }
  80
  81         setsockopt(write_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof one);
  82
  83         if(fcntl(write_fd, F_SETFL, O_NONBLOCK) < 0) {
  84                 logger(LOG_ERR, "System call `%s' failed: %s", "fcntl", strerror(errno));
  85                 running = false;
  86                 return false;
  87         }
  88
  89         if((data_fd = socket(PF_UNIX, SOCK_DGRAM, 0)) < 0) {
  90                 logger(LOG_ERR, "Could not open data %s: %s", device_info, strerror(errno));
  91                 running = false;
  92                 return false;
  93         }
  94
  95         setsockopt(data_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof one);
  96
  97         if(fcntl(data_fd, F_SETFL, O_NONBLOCK) < 0) {
  98                 logger(LOG_ERR, "System call `%s' failed: %s", "fcntl", strerror(errno));
  99                 running = false;
 100                 return false;
 101         }
 102
 103         name.zero = 0;
 104         name.pid = getpid();
 105         gettimeofday(&tv, NULL);
 106         name.usecs = tv.tv_usec;
 107         data_sun.sun_family = AF_UNIX;
 108         memcpy(&data_sun.sun_path, &name, sizeof name);
 109
 110         if(bind(data_fd, (struct sockaddr *)&data_sun, sizeof data_sun) < 0) {
 111                 logger(LOG_ERR, "Could not bind data %s: %s", device_info, strerror(errno));
 112                 running = false;
 113                 return false;
 114         }
 115
 116         if((listen_fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
 117                 logger(LOG_ERR, "Could not open %s: %s", device_info,
 118                            strerror(errno));
 119                 return false;
 120         }
 121
 122         setsockopt(listen_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof one);
 123
 124         if(fcntl(listen_fd, F_SETFL, O_NONBLOCK) < 0) {
 125                 logger(LOG_ERR, "System call `%s' failed: %s", "fcntl", strerror(errno));
 126                 return false;
 127         }
 128
 129         listen_sun.sun_family = AF_UNIX;
 130         strncpy(listen_sun.sun_path, device, sizeof listen_sun.sun_path);
 131         if(bind(listen_fd, (struct sockaddr *)&listen_sun, sizeof listen_sun) < 0) {
 132                 logger(LOG_ERR, "Could not bind %s to %s: %s", device_info, device, strerror(errno));
 133                 return false;
 134         }
 135
 136         if(listen(listen_fd, 1) < 0) {
 137                 logger(LOG_ERR, "Could not listen on %s %s: %s", device_info, device, strerror(errno));
 138                 return false;
 139         }
 140
 141         device_fd = listen_fd;
 142         state = 0;
 143
 144         logger(LOG_INFO, "%s is a %s", device, device_info);
 145
 146         if(routing_mode == RMODE_ROUTER)
 147                 overwrite_mac = true;
 148
 149         return true;
 150 }
 151
 152 void close_device(void) {
 153         if(listen_fd >= 0)
 154                 close(listen_fd);
 155
 156         if(request_fd >= 0)
 157                 close(request_fd);
 158
 159         if(data_fd >= 0)
 160                 close(data_fd);
 161
 162         if(write_fd >= 0)
 163                 close(write_fd);
 164
 165         unlink(device);
 166
 167         free(device);
 168         if(iface) free(iface);
 169 }
 170
 171 bool read_packet(vpn_packet_t *packet) {
 172         int inlen;
 173
 174         switch(state) {
 175                 case 0: {
 176                         struct sockaddr sa;
 177                         int salen = sizeof sa;
 178
 179                         request_fd = accept(listen_fd, &sa, &salen);
 180                         if(request_fd < 0) {
 181                                 logger(LOG_ERR, "Could not accept connection to %s %s: %s", device_info, device, strerror(errno));
 182                                 return false;
 183                         }
 184
 185                         if(fcntl(listen_fd, F_SETFL, O_NONBLOCK) < 0) {
 186                                 logger(LOG_ERR, "System call `%s' failed: %s", "fcntl", strerror(errno));
 187                                 running = false;
 188                                 return false;
 189                         }
 190
 191                         close(listen_fd);
 192                         listen_fd = -1;
 193                         device_fd = request_fd;
 194                         state = 1;
 195
 196                         return false;
 197                 }
 198
 199                 case 1: {
 200                         if((inlen = read(request_fd, &request, sizeof request)) != sizeof request) {
 201                                 logger(LOG_ERR, "Error while reading request from %s %s: %s", device_info,
 202                                            device, strerror(errno));
 203                                 running = false;
 204                                 return false;
 205                         }
 206
 207                         if(request.magic != 0xfeedface || request.version != 3 || request.type != REQ_NEW_CONTROL) {
 208                                 logger(LOG_ERR, "Unknown magic %x, version %d, request type %d from %s %s",
 209                                                 request.magic, request.version, request.type, device_info, device);
 210                                 running = false;
 211                                 return false;
 212                         }
 213
 214                         if(connect(write_fd, &request.sock, sizeof request.sock) < 0) {
 215                                 logger(LOG_ERR, "Could not bind write %s: %s", device_info, strerror(errno));
 216                                 running = false;
 217                                 return false;
 218                         }
 219
 220                         write(request_fd, &data_sun, sizeof data_sun);
 221                         device_fd = data_fd;
 222
 223                         logger(LOG_INFO, "Connection with UML established");
 224
 225                         state = 2;
 226                         return false;
 227                 }
 228
 229                 case 2: {
 230                         if((inlen = read(data_fd, packet->data, MTU)) <= 0) {
 231                                 logger(LOG_ERR, "Error while reading from %s %s: %s", device_info,
 232                                            device, strerror(errno));
 233                                 running = false;
 234                                 return false;
 235                         }
 236
 237                         packet->len = inlen;
 238
 239                         device_total_in += packet->len;
 240
 241                         ifdebug(TRAFFIC) logger(LOG_DEBUG, "Read packet of %d bytes from %s", packet->len,
 242                                            device_info);
 243
 244                         return true;
 245                 }
 246         }
 247 }
 248
 249 bool write_packet(vpn_packet_t *packet) {
 250         if(state != 2) {
 251                 ifdebug(TRAFFIC) logger(LOG_DEBUG, "Dropping packet of %d bytes to %s: not connected to UML yet",
 252                                 packet->len, device_info);
 253                 return false;
 254         }
 255
 256         ifdebug(TRAFFIC) logger(LOG_DEBUG, "Writing packet of %d bytes to %s",
 257                            packet->len, device_info);
 258
 259         if(write(write_fd, packet->data, packet->len) < 0) {
 260                 if(errno != EINTR && errno != EAGAIN) {
 261                         logger(LOG_ERR, "Can't write to %s %s: %s", device_info, device, strerror(errno));
 262                         running = false;
 263                 }
 264
 265                 return false;
 266         }
 267
 268         device_total_out += packet->len;
 269
 270         return true;
 271 }
 272
 273 void dump_device_stats(void) {
 274         logger(LOG_DEBUG, "Statistics for %s %s:", device_info, device);
 275         logger(LOG_DEBUG, " total bytes in:  %10"PRIu64, device_total_in);
 276         logger(LOG_DEBUG, " total bytes out: %10"PRIu64, device_total_out);
 277 }