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Add an invitation protocol.
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1 /*
2     tincd.c -- the main file for tincd
3     Copyright (C) 1998-2005 Ivo Timmermans
4                   2000-2013 Guus Sliepen <guus@tinc-vpn.org>
5                   2008      Max Rijevski <maksuf@gmail.com>
6                   2009      Michael Tokarev <mjt@tls.msk.ru>
7                   2010      Julien Muchembled <jm@jmuchemb.eu>
8                   2010      Timothy Redaelli <timothy@redaelli.eu>
9
10     This program is free software; you can redistribute it and/or modify
11     it under the terms of the GNU General Public License as published by
12     the Free Software Foundation; either version 2 of the License, or
13     (at your option) any later version.
14
15     This program is distributed in the hope that it will be useful,
16     but WITHOUT ANY WARRANTY; without even the implied warranty of
17     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18     GNU General Public License for more details.
19
20     You should have received a copy of the GNU General Public License along
21     with this program; if not, write to the Free Software Foundation, Inc.,
22     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
23 */
24
25 #include "system.h"
26
27 /* Darwin (MacOS/X) needs the following definition... */
28 #ifndef _P1003_1B_VISIBLE
29 #define _P1003_1B_VISIBLE
30 #endif
31
32 #ifdef HAVE_SYS_MMAN_H
33 #include <sys/mman.h>
34 #endif
35
36 #ifdef HAVE_LZO
37 #include LZO1X_H
38 #endif
39
40 #ifndef HAVE_MINGW
41 #include <pwd.h>
42 #include <grp.h>
43 #include <time.h>
44 #endif
45
46 #include <getopt.h>
47
48 #include "conf.h"
49 #include "control.h"
50 #include "crypto.h"
51 #include "device.h"
52 #include "logger.h"
53 #include "names.h"
54 #include "net.h"
55 #include "netutl.h"
56 #include "process.h"
57 #include "protocol.h"
58 #include "utils.h"
59 #include "xalloc.h"
60
61 /* If nonzero, display usage information and exit. */
62 static bool show_help = false;
63
64 /* If nonzero, print the version on standard output and exit.  */
65 static bool show_version = false;
66
67 /* If nonzero, use null ciphers and skip all key exchanges. */
68 bool bypass_security = false;
69
70 #ifdef HAVE_MLOCKALL
71 /* If nonzero, disable swapping for this process. */
72 static bool do_mlock = false;
73 #endif
74
75 #ifndef HAVE_MINGW
76 /* If nonzero, chroot to netdir after startup. */
77 static bool do_chroot = false;
78
79 /* If !NULL, do setuid to given user after startup */
80 static const char *switchuser = NULL;
81 #endif
82
83 /* If nonzero, write log entries to a separate file. */
84 bool use_logfile = false;
85
86 char **g_argv;                  /* a copy of the cmdline arguments */
87
88 static int status = 1;
89
90 static struct option const long_options[] = {
91         {"config", required_argument, NULL, 'c'},
92         {"net", required_argument, NULL, 'n'},
93         {"help", no_argument, NULL, 1},
94         {"version", no_argument, NULL, 2},
95         {"no-detach", no_argument, NULL, 'D'},
96         {"debug", optional_argument, NULL, 'd'},
97         {"bypass-security", no_argument, NULL, 3},
98         {"mlock", no_argument, NULL, 'L'},
99         {"chroot", no_argument, NULL, 'R'},
100         {"user", required_argument, NULL, 'U'},
101         {"logfile", optional_argument, NULL, 4},
102         {"pidfile", required_argument, NULL, 5},
103         {"option", required_argument, NULL, 'o'},
104         {NULL, 0, NULL, 0}
105 };
106
107 #ifdef HAVE_MINGW
108 static struct WSAData wsa_state;
109 CRITICAL_SECTION mutex;
110 int main2(int argc, char **argv);
111 #endif
112
113 static void usage(bool status) {
114         if(status)
115                 fprintf(stderr, "Try `%s --help\' for more information.\n",
116                                 program_name);
117         else {
118                 printf("Usage: %s [option]...\n\n", program_name);
119                 printf( "  -c, --config=DIR              Read configuration options from DIR.\n"
120                                 "  -D, --no-detach               Don't fork and detach.\n"
121                                 "  -d, --debug[=LEVEL]           Increase debug level or set it to LEVEL.\n"
122                                 "  -n, --net=NETNAME             Connect to net NETNAME.\n"
123 #ifdef HAVE_MLOCKALL
124                                 "  -L, --mlock                   Lock tinc into main memory.\n"
125 #endif
126                                 "      --logfile[=FILENAME]      Write log entries to a logfile.\n"
127                                 "      --pidfile=FILENAME        Write PID and control socket cookie to FILENAME.\n"
128                                 "      --bypass-security         Disables meta protocol security, for debugging.\n"
129                                 "  -o, --option[HOST.]KEY=VALUE  Set global/host configuration value.\n"
130 #ifndef HAVE_MINGW
131                                 "  -R, --chroot                  chroot to NET dir at startup.\n"
132                                 "  -U, --user=USER               setuid to given USER at startup.\n"
133 #endif
134                                 "      --help                    Display this help and exit.\n"
135                                 "      --version                 Output version information and exit.\n\n");
136                 printf("Report bugs to tinc@tinc-vpn.org.\n");
137         }
138 }
139
140 static bool parse_options(int argc, char **argv) {
141         config_t *cfg;
142         int r;
143         int option_index = 0;
144         int lineno = 0;
145
146         cmdline_conf = list_alloc((list_action_t)free_config);
147
148         while((r = getopt_long(argc, argv, "c:DLd::n:o:RU:", long_options, &option_index)) != EOF) {
149                 switch (r) {
150                         case 0:   /* long option */
151                                 break;
152
153                         case 'c': /* config file */
154                                 confbase = xstrdup(optarg);
155                                 break;
156
157                         case 'D': /* no detach */
158                                 do_detach = false;
159                                 break;
160
161                         case 'L': /* no detach */
162 #ifndef HAVE_MLOCKALL
163                                 logger(DEBUG_ALWAYS, LOG_ERR, "The %s option is not supported on this platform.", argv[optind - 1]);
164                                 return false;
165 #else
166                                 do_mlock = true;
167                                 break;
168 #endif
169
170                         case 'd': /* inc debug level */
171                                 if(optarg)
172                                         debug_level = atoi(optarg);
173                                 else
174                                         debug_level++;
175                                 break;
176
177                         case 'n': /* net name given */
178                                 netname = xstrdup(optarg);
179                                 break;
180
181                         case 'o': /* option */
182                                 cfg = parse_config_line(optarg, NULL, ++lineno);
183                                 if (!cfg)
184                                         return false;
185                                 list_insert_tail(cmdline_conf, cfg);
186                                 break;
187
188 #ifdef HAVE_MINGW
189                         case 'R':
190                         case 'U':
191                                 logger(DEBUG_ALWAYS, LOG_ERR, "The %s option is not supported on this platform.", argv[optind - 1]);
192                                 return false;
193 #else
194                         case 'R': /* chroot to NETNAME dir */
195                                 do_chroot = true;
196                                 break;
197
198                         case 'U': /* setuid to USER */
199                                 switchuser = optarg;
200                                 break;
201 #endif
202
203                         case 1:   /* show help */
204                                 show_help = true;
205                                 break;
206
207                         case 2:   /* show version */
208                                 show_version = true;
209                                 break;
210
211                         case 3:   /* bypass security */
212                                 bypass_security = true;
213                                 break;
214
215                         case 4:   /* write log entries to a file */
216                                 use_logfile = true;
217                                 if(optarg)
218                                         logfilename = xstrdup(optarg);
219                                 break;
220
221                         case 5:   /* open control socket here */
222                                 pidfilename = xstrdup(optarg);
223                                 break;
224
225                         case '?': /* wrong options */
226                                 usage(true);
227                                 return false;
228
229                         default:
230                                 break;
231                 }
232         }
233
234         if(!netname && (netname = getenv("NETNAME")))
235                 netname = xstrdup(netname);
236
237         /* netname "." is special: a "top-level name" */
238
239         if(netname && (!*netname || !strcmp(netname, "."))) {
240                 free(netname);
241                 netname = NULL;
242         }
243
244         if(netname && (strpbrk(netname, "\\/") || *netname == '.')) {
245                 fprintf(stderr, "Invalid character in netname!\n");
246                 return false;
247         }
248
249         return true;
250 }
251
252 static bool drop_privs(void) {
253 #ifndef HAVE_MINGW
254         uid_t uid = 0;
255         if (switchuser) {
256                 struct passwd *pw = getpwnam(switchuser);
257                 if (!pw) {
258                         logger(DEBUG_ALWAYS, LOG_ERR, "unknown user `%s'", switchuser);
259                         return false;
260                 }
261                 uid = pw->pw_uid;
262                 if (initgroups(switchuser, pw->pw_gid) != 0 ||
263                     setgid(pw->pw_gid) != 0) {
264                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
265                                "initgroups", strerror(errno));
266                         return false;
267                 }
268 #ifndef __ANDROID__
269 // Not supported in android NDK
270                 endgrent();
271                 endpwent();
272 #endif
273         }
274         if (do_chroot) {
275                 tzset();        /* for proper timestamps in logs */
276                 if (chroot(confbase) != 0 || chdir("/") != 0) {
277                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
278                                "chroot", strerror(errno));
279                         return false;
280                 }
281                 free(confbase);
282                 confbase = xstrdup("");
283         }
284         if (switchuser)
285                 if (setuid(uid) != 0) {
286                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
287                                "setuid", strerror(errno));
288                         return false;
289                 }
290 #endif
291         return true;
292 }
293
294 #ifdef HAVE_MINGW
295 # define setpriority(level) !SetPriorityClass(GetCurrentProcess(), (level))
296 #else
297 # define NORMAL_PRIORITY_CLASS 0
298 # define BELOW_NORMAL_PRIORITY_CLASS 10
299 # define HIGH_PRIORITY_CLASS -10
300 # define setpriority(level) (setpriority(PRIO_PROCESS, 0, (level)))
301 #endif
302
303 int main(int argc, char **argv) {
304         program_name = argv[0];
305
306         if(!parse_options(argc, argv))
307                 return 1;
308
309         make_names();
310
311         if(show_version) {
312                 printf("%s version %s (built %s %s, protocol %d.%d)\n", PACKAGE,
313                            VERSION, __DATE__, __TIME__, PROT_MAJOR, PROT_MINOR);
314                 printf("Copyright (C) 1998-2012 Ivo Timmermans, Guus Sliepen and others.\n"
315                                 "See the AUTHORS file for a complete list.\n\n"
316                                 "tinc comes with ABSOLUTELY NO WARRANTY.  This is free software,\n"
317                                 "and you are welcome to redistribute it under certain conditions;\n"
318                                 "see the file COPYING for details.\n");
319
320                 return 0;
321         }
322
323         if(show_help) {
324                 usage(false);
325                 return 0;
326         }
327
328 #ifdef HAVE_MINGW
329         if(WSAStartup(MAKEWORD(2, 2), &wsa_state)) {
330                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "WSAStartup", winerror(GetLastError()));
331                 return 1;
332         }
333 #endif
334
335         openlogger("tinc", use_logfile?LOGMODE_FILE:LOGMODE_STDERR);
336
337         g_argv = argv;
338
339         if(getenv("LISTEN_PID") && atoi(getenv("LISTEN_PID")) == getpid())
340                 do_detach = false;
341 #ifdef HAVE_UNSETENV
342         unsetenv("LISTEN_PID");
343 #endif
344
345         init_configuration(&config_tree);
346
347         /* Slllluuuuuuurrrrp! */
348
349         gettimeofday(&now, NULL);
350         srand(now.tv_sec + now.tv_usec);
351         crypto_init();
352
353         if(!read_server_config())
354                 return 1;
355
356 #ifdef HAVE_LZO
357         if(lzo_init() != LZO_E_OK) {
358                 logger(DEBUG_ALWAYS, LOG_ERR, "Error initializing LZO compressor!");
359                 return 1;
360         }
361 #endif
362
363 #ifdef HAVE_MINGW
364         if(!do_detach || !init_service())
365                 return main2(argc, argv);
366         else
367                 return 1;
368 }
369
370 int main2(int argc, char **argv) {
371         InitializeCriticalSection(&mutex);
372         EnterCriticalSection(&mutex);
373 #endif
374         char *priority = NULL;
375
376         if(!detach())
377                 return 1;
378
379 #ifdef HAVE_MLOCKALL
380         /* Lock all pages into memory if requested.
381          * This has to be done after daemon()/fork() so it works for child.
382          * No need to do that in parent as it's very short-lived. */
383         if(do_mlock && mlockall(MCL_CURRENT | MCL_FUTURE) != 0) {
384                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "mlockall",
385                    strerror(errno));
386                 return 1;
387         }
388 #endif
389
390         /* Setup sockets and open device. */
391
392         if(!setup_network())
393                 goto end_nonet;
394
395         if(!init_control())
396                 goto end_nonet;
397
398         /* Initiate all outgoing connections. */
399
400         try_outgoing_connections();
401
402         /* Change process priority */
403
404         if(get_config_string(lookup_config(config_tree, "ProcessPriority"), &priority)) {
405                 if(!strcasecmp(priority, "Normal")) {
406                         if (setpriority(NORMAL_PRIORITY_CLASS) != 0) {
407                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
408                                 goto end;
409                         }
410                 } else if(!strcasecmp(priority, "Low")) {
411                         if (setpriority(BELOW_NORMAL_PRIORITY_CLASS) != 0) {
412                                        logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
413                                 goto end;
414                         }
415                 } else if(!strcasecmp(priority, "High")) {
416                         if (setpriority(HIGH_PRIORITY_CLASS) != 0) {
417                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
418                                 goto end;
419                         }
420                 } else {
421                         logger(DEBUG_ALWAYS, LOG_ERR, "Invalid priority `%s`!", priority);
422                         goto end;
423                 }
424         }
425
426         /* drop privileges */
427         if (!drop_privs())
428                 goto end;
429
430         /* Start main loop. It only exits when tinc is killed. */
431
432         status = main_loop();
433
434         /* Shutdown properly. */
435
436         if(debug_level >= DEBUG_CONNECTIONS)
437                 devops.dump_stats();
438
439         close_network_connections();
440
441 end:
442         exit_control();
443
444 end_nonet:
445         logger(DEBUG_ALWAYS, LOG_NOTICE, "Terminating");
446
447         free(priority);
448
449         crypto_exit();
450
451         exit_configuration(&config_tree);
452         free(cmdline_conf);
453         free_names();
454
455         return status;
456 }