git.tinc-vpn.org Git - tinc/blob - src/uml_device.c

   1 /*
   2     device.c -- UML network socket
   3     Copyright (C) 2002-2005 Ivo Timmermans,
   4                   2002-2013 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 "names.h"
  28 #include "net.h"
  29 #include "logger.h"
  30 #include "utils.h"
  31 #include "route.h"
  32 #include "xalloc.h"
  33
  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 static char *device_info;
  40
  41 static uint64_t device_total_in = 0;
  42 static uint64_t device_total_out = 0;
  43
  44 enum request_type { REQ_NEW_CONTROL };
  45
  46 static struct request {
  47   uint32_t magic;
  48   uint32_t version;
  49   enum request_type type;
  50   struct sockaddr_un sock;
  51 } request;
  52
  53 static struct sockaddr_un data_sun;
  54
  55 static bool setup_device(void) {
  56         struct sockaddr_un listen_sun;
  57         static const int one = 1;
  58         struct {
  59                 char zero;
  60                 int pid;
  61                 int usecs;
  62         } name;
  63         struct timeval tv;
  64
  65         if(!get_config_string(lookup_config(config_tree, "Device"), &device))
  66                 xasprintf(&device, LOCALSTATEDIR "/run/%s.umlsocket", identname);
  67
  68         get_config_string(lookup_config(config_tree, "Interface"), &iface);
  69
  70         device_info = "UML network socket";
  71
  72         if((write_fd = socket(PF_UNIX, SOCK_DGRAM, 0)) < 0) {
  73                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not open write %s: %s", device_info, strerror(errno));
  74                 event_exit();
  75                 return false;
  76         }
  77
  78 #ifdef FD_CLOEXEC
  79         fcntl(write_fd, F_SETFD, FD_CLOEXEC);
  80 #endif
  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(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "fcntl", strerror(errno));
  86                 event_exit();
  87                 return false;
  88         }
  89
  90         if((data_fd = socket(PF_UNIX, SOCK_DGRAM, 0)) < 0) {
  91                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not open data %s: %s", device_info, strerror(errno));
  92                 event_exit();
  93                 return false;
  94         }
  95
  96 #ifdef FD_CLOEXEC
  97         fcntl(data_fd, F_SETFD, FD_CLOEXEC);
  98 #endif
  99
 100         setsockopt(data_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof one);
 101
 102         if(fcntl(data_fd, F_SETFL, O_NONBLOCK) < 0) {
 103                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "fcntl", strerror(errno));
 104                 event_exit();
 105                 return false;
 106         }
 107
 108         name.zero = 0;
 109         name.pid = getpid();
 110         gettimeofday(&tv, NULL);
 111         name.usecs = tv.tv_usec;
 112         data_sun.sun_family = AF_UNIX;
 113         memcpy(&data_sun.sun_path, &name, sizeof name);
 114
 115         if(bind(data_fd, (struct sockaddr *)&data_sun, sizeof data_sun) < 0) {
 116                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not bind data %s: %s", device_info, strerror(errno));
 117                 event_exit();
 118                 return false;
 119         }
 120
 121         if((listen_fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
 122                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not open %s: %s", device_info,
 123                            strerror(errno));
 124                 return false;
 125         }
 126
 127 #ifdef FD_CLOEXEC
 128         fcntl(device_fd, F_SETFD, FD_CLOEXEC);
 129 #endif
 130
 131         setsockopt(listen_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof one);
 132
 133         if(fcntl(listen_fd, F_SETFL, O_NONBLOCK) < 0) {
 134                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "fcntl", strerror(errno));
 135                 return false;
 136         }
 137
 138         listen_sun.sun_family = AF_UNIX;
 139         strncpy(listen_sun.sun_path, device, sizeof listen_sun.sun_path);
 140         if(bind(listen_fd, (struct sockaddr *)&listen_sun, sizeof listen_sun) < 0) {
 141                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not bind %s to %s: %s", device_info, device, strerror(errno));
 142                 return false;
 143         }
 144
 145         if(listen(listen_fd, 1) < 0) {
 146                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not listen on %s %s: %s", device_info, device, strerror(errno));
 147                 return false;
 148         }
 149
 150         device_fd = listen_fd;
 151         state = 0;
 152
 153         logger(DEBUG_ALWAYS, LOG_INFO, "%s is a %s", device, device_info);
 154
 155         if(routing_mode == RMODE_ROUTER)
 156                 overwrite_mac = true;
 157
 158         return true;
 159 }
 160
 161 void close_device(void) {
 162         if(listen_fd >= 0)
 163                 close(listen_fd);
 164
 165         if(request_fd >= 0)
 166                 close(request_fd);
 167
 168         if(data_fd >= 0)
 169                 close(data_fd);
 170
 171         if(write_fd >= 0)
 172                 close(write_fd);
 173
 174         unlink(device);
 175
 176         free(device);
 177         if(iface) free(iface);
 178 }
 179
 180 static bool read_packet(vpn_packet_t *packet) {
 181         int inlen;
 182
 183         switch(state) {
 184                 case 0: {
 185                         struct sockaddr sa;
 186                         socklen_t salen = sizeof sa;
 187
 188                         request_fd = accept(listen_fd, &sa, &salen);
 189                         if(request_fd < 0) {
 190                                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not accept connection to %s %s: %s", device_info, device, strerror(errno));
 191                                 return false;
 192                         }
 193
 194 #ifdef FD_CLOEXEC
 195                         fcntl(request_fd, F_SETFD, FD_CLOEXEC);
 196 #endif
 197
 198                         if(fcntl(listen_fd, F_SETFL, O_NONBLOCK) < 0) {
 199                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "fcntl", strerror(errno));
 200                                 event_exit();
 201                                 return false;
 202                         }
 203
 204                         close(listen_fd);
 205                         listen_fd = -1;
 206                         device_fd = request_fd;
 207                         state = 1;
 208
 209                         return false;
 210                 }
 211
 212                 case 1: {
 213                         if((inlen = read(request_fd, &request, sizeof request)) != sizeof request) {
 214                                 logger(DEBUG_ALWAYS, LOG_ERR, "Error while reading request from %s %s: %s", device_info,
 215                                            device, strerror(errno));
 216                                 event_exit();
 217                                 return false;
 218                         }
 219
 220                         if(request.magic != 0xfeedface || request.version != 3 || request.type != REQ_NEW_CONTROL) {
 221                                 logger(DEBUG_ALWAYS, LOG_ERR, "Unknown magic %x, version %d, request type %d from %s %s",
 222                                                 request.magic, request.version, request.type, device_info, device);
 223                                 event_exit();
 224                                 return false;
 225                         }
 226
 227                         if(connect(write_fd, &request.sock, sizeof request.sock) < 0) {
 228                                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not bind write %s: %s", device_info, strerror(errno));
 229                                 event_exit();
 230                                 return false;
 231                         }
 232
 233                         write(request_fd, &data_sun, sizeof data_sun);
 234                         device_fd = data_fd;
 235
 236                         logger(DEBUG_ALWAYS, LOG_INFO, "Connection with UML established");
 237
 238                         state = 2;
 239                         return false;
 240                 }
 241
 242                 case 2: {
 243                         if((inlen = read(data_fd, packet->data, MTU)) <= 0) {
 244                                 logger(DEBUG_ALWAYS, LOG_ERR, "Error while reading from %s %s: %s", device_info,
 245                                            device, strerror(errno));
 246                                 event_exit();
 247                                 return false;
 248                         }
 249
 250                         packet->len = inlen;
 251
 252                         device_total_in += packet->len;
 253
 254                         logger(DEBUG_TRAFFIC, LOG_DEBUG, "Read packet of %d bytes from %s", packet->len,
 255                                            device_info);
 256
 257                         return true;
 258                 }
 259
 260                 default:
 261                         logger(DEBUG_ALWAYS, LOG_ERR, "Invalid value for state variable in " __FILE__);
 262                         abort();
 263         }
 264 }
 265
 266 static bool write_packet(vpn_packet_t *packet) {
 267         if(state != 2) {
 268                 logger(DEBUG_TRAFFIC, LOG_DEBUG, "Dropping packet of %d bytes to %s: not connected to UML yet",
 269                                 packet->len, device_info);
 270                 return false;
 271         }
 272
 273         logger(DEBUG_TRAFFIC, LOG_DEBUG, "Writing packet of %d bytes to %s",
 274                            packet->len, device_info);
 275
 276         if(write(write_fd, packet->data, packet->len) < 0) {
 277                 if(errno != EINTR && errno != EAGAIN) {
 278                         logger(DEBUG_ALWAYS, LOG_ERR, "Can't write to %s %s: %s", device_info, device, strerror(errno));
 279                         event_exit();
 280                 }
 281
 282                 return false;
 283         }
 284
 285         device_total_out += packet->len;
 286
 287         return true;
 288 }
 289
 290 static void dump_device_stats(void) {
 291         logger(DEBUG_ALWAYS, LOG_DEBUG, "Statistics for %s %s:", device_info, device);
 292         logger(DEBUG_ALWAYS, LOG_DEBUG, " total bytes in:  %10"PRIu64, device_total_in);
 293         logger(DEBUG_ALWAYS, LOG_DEBUG, " total bytes out: %10"PRIu64, device_total_out);
 294 }
 295
 296 const devops_t uml_devops = {
 297         .setup = setup_device,
 298         .close = close_device,
 299         .read = read_packet,
 300         .write = write_packet,
 301         .dump_stats = dump_device_stats,
 302 };