Fix potential memory leaks found by the Clang static analyzer.
[tinc] / src / tincd.c
1 /*
2     tincd.c -- the main file for tincd
3     Copyright (C) 1998-2005 Ivo Timmermans
4                   2000-2016 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 "conf.h"
47 #include "control.h"
48 #include "crypto.h"
49 #include "device.h"
50 #include "event.h"
51 #include "logger.h"
52 #include "names.h"
53 #include "net.h"
54 #include "netutl.h"
55 #include "process.h"
56 #include "protocol.h"
57 #include "utils.h"
58 #include "xalloc.h"
59 #include "version.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 /* If nonzero, use syslog instead of stderr in no-detach mode. */
87 bool use_syslog = false;
88
89 char **g_argv;                  /* a copy of the cmdline arguments */
90
91 static int status = 1;
92
93 static struct option const long_options[] = {
94         {"config", required_argument, NULL, 'c'},
95         {"net", required_argument, NULL, 'n'},
96         {"help", no_argument, NULL, 1},
97         {"version", no_argument, NULL, 2},
98         {"no-detach", no_argument, NULL, 'D'},
99         {"debug", optional_argument, NULL, 'd'},
100         {"bypass-security", no_argument, NULL, 3},
101         {"mlock", no_argument, NULL, 'L'},
102         {"chroot", no_argument, NULL, 'R'},
103         {"user", required_argument, NULL, 'U'},
104         {"logfile", optional_argument, NULL, 4},
105         {"syslog", no_argument, NULL, 's'},
106         {"pidfile", required_argument, NULL, 5},
107         {"option", required_argument, NULL, 'o'},
108         {NULL, 0, NULL, 0}
109 };
110
111 #ifdef HAVE_MINGW
112 static struct WSAData wsa_state;
113 int main2(int argc, char **argv);
114 #endif
115
116 static void usage(bool status) {
117         if(status)
118                 fprintf(stderr, "Try `%s --help\' for more information.\n",
119                                 program_name);
120         else {
121                 printf("Usage: %s [option]...\n\n", program_name);
122                 printf( "  -c, --config=DIR              Read configuration options from DIR.\n"
123                                 "  -D, --no-detach               Don't fork and detach.\n"
124                                 "  -d, --debug[=LEVEL]           Increase debug level or set it to LEVEL.\n"
125                                 "  -n, --net=NETNAME             Connect to net NETNAME.\n"
126 #ifdef HAVE_MLOCKALL
127                                 "  -L, --mlock                   Lock tinc into main memory.\n"
128 #endif
129                                 "      --logfile[=FILENAME]      Write log entries to a logfile.\n"
130                                 "  -s  --syslog                  Use syslog instead of stderr with --no-detach.\n"
131                                 "      --pidfile=FILENAME        Write PID and control socket cookie to FILENAME.\n"
132                                 "      --bypass-security         Disables meta protocol security, for debugging.\n"
133                                 "  -o, --option[HOST.]KEY=VALUE  Set global/host configuration value.\n"
134 #ifndef HAVE_MINGW
135                                 "  -R, --chroot                  chroot to NET dir at startup.\n"
136                                 "  -U, --user=USER               setuid to given USER at startup.\n"
137 #endif
138                                 "      --help                    Display this help and exit.\n"
139                                 "      --version                 Output version information and exit.\n\n");
140                 printf("Report bugs to tinc@tinc-vpn.org.\n");
141         }
142 }
143
144 static bool parse_options(int argc, char **argv) {
145         config_t *cfg;
146         int r;
147         int option_index = 0;
148         int lineno = 0;
149
150         cmdline_conf = list_alloc((list_action_t)free_config);
151
152         while((r = getopt_long(argc, argv, "c:DLd::n:so:RU:", long_options, &option_index)) != EOF) {
153                 switch (r) {
154                         case 0:   /* long option */
155                                 break;
156
157                         case 'c': /* config file */
158                                 confbase = xstrdup(optarg);
159                                 break;
160
161                         case 'D': /* no detach */
162                                 do_detach = false;
163                                 break;
164
165                         case 'L': /* no detach */
166 #ifndef HAVE_MLOCKALL
167                                 logger(DEBUG_ALWAYS, LOG_ERR, "The %s option is not supported on this platform.", argv[optind - 1]);
168                                 return false;
169 #else
170                                 do_mlock = true;
171                                 break;
172 #endif
173
174                         case 'd': /* increase debug level */
175                                 if(!optarg && optind < argc && *argv[optind] != '-')
176                                         optarg = argv[optind++];
177                                 if(optarg)
178                                         debug_level = atoi(optarg);
179                                 else
180                                         debug_level++;
181                                 break;
182
183                         case 'n': /* net name given */
184                                 netname = xstrdup(optarg);
185                                 break;
186
187                         case 's': /* syslog */
188                                 use_logfile = false;
189                                 use_syslog = true;
190                                 break;
191
192                         case 'o': /* option */
193                                 cfg = parse_config_line(optarg, NULL, ++lineno);
194                                 if (!cfg)
195                                         return false;
196                                 list_insert_tail(cmdline_conf, cfg);
197                                 break;
198
199 #ifdef HAVE_MINGW
200                         case 'R':
201                         case 'U':
202                                 logger(DEBUG_ALWAYS, LOG_ERR, "The %s option is not supported on this platform.", argv[optind - 1]);
203                                 return false;
204 #else
205                         case 'R': /* chroot to NETNAME dir */
206                                 do_chroot = true;
207                                 break;
208
209                         case 'U': /* setuid to USER */
210                                 switchuser = optarg;
211                                 break;
212 #endif
213
214                         case 1:   /* show help */
215                                 show_help = true;
216                                 break;
217
218                         case 2:   /* show version */
219                                 show_version = true;
220                                 break;
221
222                         case 3:   /* bypass security */
223                                 bypass_security = true;
224                                 break;
225
226                         case 4:   /* write log entries to a file */
227                                 use_syslog = false;
228                                 use_logfile = true;
229                                 if(!optarg && optind < argc && *argv[optind] != '-')
230                                         optarg = argv[optind++];
231                                 if(optarg)
232                                         logfilename = xstrdup(optarg);
233                                 break;
234
235                         case 5:   /* open control socket here */
236                                 pidfilename = xstrdup(optarg);
237                                 break;
238
239                         case '?': /* wrong options */
240                                 usage(true);
241                                 return false;
242
243                         default:
244                                 break;
245                 }
246         }
247
248         if(optind < argc) {
249                 fprintf(stderr, "%s: unrecognized argument '%s'\n", argv[0], argv[optind]);
250                 usage(true);
251                 return false;
252         }
253
254         if(!netname && (netname = getenv("NETNAME")))
255                 netname = xstrdup(netname);
256
257         /* netname "." is special: a "top-level name" */
258
259         if(netname && (!*netname || !strcmp(netname, "."))) {
260                 free(netname);
261                 netname = NULL;
262         }
263
264         if(netname && !check_netname(netname, false)) {
265                 fprintf(stderr, "Invalid character in netname!\n");
266                 return false;
267         }
268
269         if(netname && !check_netname(netname, true))
270                 fprintf(stderr, "Warning: unsafe character in netname!\n");
271
272         return true;
273 }
274
275 static bool drop_privs(void) {
276 #ifndef HAVE_MINGW
277         uid_t uid = 0;
278         if (switchuser) {
279                 struct passwd *pw = getpwnam(switchuser);
280                 if (!pw) {
281                         logger(DEBUG_ALWAYS, LOG_ERR, "unknown user `%s'", switchuser);
282                         return false;
283                 }
284                 uid = pw->pw_uid;
285                 if (initgroups(switchuser, pw->pw_gid) != 0 ||
286                     setgid(pw->pw_gid) != 0) {
287                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
288                                "initgroups", strerror(errno));
289                         return false;
290                 }
291 #ifndef __ANDROID__
292 // Not supported in android NDK
293                 endgrent();
294                 endpwent();
295 #endif
296         }
297         if (do_chroot) {
298                 tzset();        /* for proper timestamps in logs */
299                 if (chroot(confbase) != 0 || chdir("/") != 0) {
300                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
301                                "chroot", strerror(errno));
302                         return false;
303                 }
304                 free(confbase);
305                 confbase = xstrdup("");
306         }
307         if (switchuser)
308                 if (setuid(uid) != 0) {
309                         logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s",
310                                "setuid", strerror(errno));
311                         return false;
312                 }
313 #endif
314         return true;
315 }
316
317 #ifdef HAVE_MINGW
318 # define setpriority(level) !SetPriorityClass(GetCurrentProcess(), (level))
319
320 static void stop_handler(void *data, int flags) {
321         event_exit();
322 }
323
324 static BOOL WINAPI console_ctrl_handler(DWORD type) {
325         logger(DEBUG_ALWAYS, LOG_NOTICE, "Got console shutdown request");
326         if (WSASetEvent(stop_io.event) == FALSE)
327                 abort();
328         return TRUE;
329 }
330 #else
331 # define NORMAL_PRIORITY_CLASS 0
332 # define BELOW_NORMAL_PRIORITY_CLASS 10
333 # define HIGH_PRIORITY_CLASS -10
334 # define setpriority(level) (setpriority(PRIO_PROCESS, 0, (level)))
335 #endif
336
337 int main(int argc, char **argv) {
338         program_name = argv[0];
339
340         if(!parse_options(argc, argv))
341                 return 1;
342
343         make_names(true);
344         chdir(confbase);
345
346         if(show_version) {
347                 printf("%s version %s (built %s %s, protocol %d.%d)\n", PACKAGE,
348                            BUILD_VERSION, BUILD_DATE, BUILD_TIME, PROT_MAJOR, PROT_MINOR);
349                 printf("Copyright (C) 1998-2016 Ivo Timmermans, Guus Sliepen and others.\n"
350                                 "See the AUTHORS file for a complete list.\n\n"
351                                 "tinc comes with ABSOLUTELY NO WARRANTY.  This is free software,\n"
352                                 "and you are welcome to redistribute it under certain conditions;\n"
353                                 "see the file COPYING for details.\n");
354
355                 return 0;
356         }
357
358         if(show_help) {
359                 usage(false);
360                 return 0;
361         }
362
363 #ifdef HAVE_MINGW
364         if(WSAStartup(MAKEWORD(2, 2), &wsa_state)) {
365                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "WSAStartup", winerror(GetLastError()));
366                 return 1;
367         }
368 #else
369         // Check if we got an umbilical fd from the process that started us
370         char *umbstr = getenv("TINC_UMBILICAL");
371         if(umbstr) {
372                 umbilical = atoi(umbstr);
373                 if(fcntl(umbilical, F_GETFL) < 0)
374                         umbilical = 0;
375 #ifdef FD_CLOEXEC
376                 if(umbilical)
377                         fcntl(umbilical, F_SETFD, FD_CLOEXEC);
378 #endif
379         }
380 #endif
381
382         openlogger("tinc", use_logfile?LOGMODE_FILE:LOGMODE_STDERR);
383
384         g_argv = argv;
385
386         if(getenv("LISTEN_PID") && atoi(getenv("LISTEN_PID")) == getpid())
387                 do_detach = false;
388 #ifdef HAVE_UNSETENV
389         unsetenv("LISTEN_PID");
390 #endif
391
392         init_configuration(&config_tree);
393
394         /* Slllluuuuuuurrrrp! */
395
396         gettimeofday(&now, NULL);
397         srand(now.tv_sec + now.tv_usec);
398         crypto_init();
399
400         if(!read_server_config())
401                 return 1;
402
403 #ifdef HAVE_LZO
404         if(lzo_init() != LZO_E_OK) {
405                 logger(DEBUG_ALWAYS, LOG_ERR, "Error initializing LZO compressor!");
406                 return 1;
407         }
408 #endif
409
410 #ifdef HAVE_MINGW
411         io_add_event(&stop_io, stop_handler, NULL, WSACreateEvent());
412         if (stop_io.event == FALSE)
413                 abort();
414
415         int result;
416         if(!do_detach || !init_service()) {
417                 SetConsoleCtrlHandler(console_ctrl_handler, TRUE);
418                 result = main2(argc, argv);
419         } else
420                 result = 1;
421
422         if (WSACloseEvent(stop_io.event) == FALSE)
423                 abort();
424         io_del(&stop_io);
425         return result;
426 }
427
428 int main2(int argc, char **argv) {
429 #endif
430         char *priority = NULL;
431
432         if(!detach())
433                 return 1;
434
435 #ifdef HAVE_MLOCKALL
436         /* Lock all pages into memory if requested.
437          * This has to be done after daemon()/fork() so it works for child.
438          * No need to do that in parent as it's very short-lived. */
439         if(do_mlock && mlockall(MCL_CURRENT | MCL_FUTURE) != 0) {
440                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "mlockall",
441                    strerror(errno));
442                 return 1;
443         }
444 #endif
445
446         /* Setup sockets and open device. */
447
448         if(!setup_network())
449                 goto end;
450
451         /* Change process priority */
452
453         if(get_config_string(lookup_config(config_tree, "ProcessPriority"), &priority)) {
454                 if(!strcasecmp(priority, "Normal")) {
455                         if (setpriority(NORMAL_PRIORITY_CLASS) != 0) {
456                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
457                                 goto end;
458                         }
459                 } else if(!strcasecmp(priority, "Low")) {
460                         if (setpriority(BELOW_NORMAL_PRIORITY_CLASS) != 0) {
461                                        logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
462                                 goto end;
463                         }
464                 } else if(!strcasecmp(priority, "High")) {
465                         if (setpriority(HIGH_PRIORITY_CLASS) != 0) {
466                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setpriority", strerror(errno));
467                                 goto end;
468                         }
469                 } else {
470                         logger(DEBUG_ALWAYS, LOG_ERR, "Invalid priority `%s`!", priority);
471                         goto end;
472                 }
473         }
474
475         /* drop privileges */
476         if (!drop_privs())
477                 goto end;
478
479         /* Start main loop. It only exits when tinc is killed. */
480
481         logger(DEBUG_ALWAYS, LOG_NOTICE, "Ready");
482
483         if(umbilical) { // snip!
484                 write(umbilical, "", 1);
485                 close(umbilical);
486                 umbilical = 0;
487         }
488
489         try_outgoing_connections();
490
491         status = main_loop();
492
493         /* Shutdown properly. */
494
495 end:
496         close_network_connections();
497
498         logger(DEBUG_ALWAYS, LOG_NOTICE, "Terminating");
499
500         free(priority);
501
502         crypto_exit();
503
504         exit_configuration(&config_tree);
505         free(cmdline_conf);
506         free_names();
507
508         return status;
509 }