| 1 | /* |
| 2 | * This file is part of secnet. |
| 3 | * See README for full list of copyright holders. |
| 4 | * |
| 5 | * secnet is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License as published by |
| 7 | * the Free Software Foundation; either version 3 of the License, or |
| 8 | * (at your option) any later version. |
| 9 | * |
| 10 | * secnet is distributed in the hope that it will be useful, but |
| 11 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | * General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * version 3 along with secnet; if not, see |
| 17 | * https://www.gnu.org/licenses/gpl.html. |
| 18 | */ |
| 19 | |
| 20 | #include "secnet.h" |
| 21 | #include <stdio.h> |
| 22 | #include <assert.h> |
| 23 | #include <limits.h> |
| 24 | #include <string.h> |
| 25 | #include <getopt.h> |
| 26 | #include <errno.h> |
| 27 | #include <unistd.h> |
| 28 | #include <sys/socket.h> |
| 29 | #include <arpa/inet.h> |
| 30 | #include <pwd.h> |
| 31 | #include <grp.h> |
| 32 | |
| 33 | #include "util.h" |
| 34 | #include "conffile.h" |
| 35 | #include "process.h" |
| 36 | |
| 37 | #if __APPLE__ |
| 38 | /* apple's poll() does not work on char devs */ |
| 39 | # define USE_SELECT 1 |
| 40 | #endif |
| 41 | |
| 42 | /* XXX should be from autoconf */ |
| 43 | static const char *configfile="/etc/secnet/secnet.conf"; |
| 44 | static const char *sites_key="sites"; |
| 45 | bool_t just_check_config=False; |
| 46 | static char *userid=NULL; |
| 47 | static uid_t uid=0; |
| 48 | static gid_t gid; |
| 49 | bool_t background=True; |
| 50 | static char *pidfile=NULL; |
| 51 | bool_t require_root_privileges=False; |
| 52 | cstring_t require_root_privileges_explanation=NULL; |
| 53 | |
| 54 | static pid_t secnet_pid; |
| 55 | |
| 56 | /* Structures dealing with poll() call */ |
| 57 | struct poll_interest { |
| 58 | beforepoll_fn *before; /* 0 if deregistered and waiting to be deleted */ |
| 59 | afterpoll_fn *after; |
| 60 | void *state; |
| 61 | int32_t nfds; |
| 62 | cstring_t desc; |
| 63 | LIST_ENTRY(poll_interest) entry; |
| 64 | }; |
| 65 | static LIST_HEAD(, poll_interest) reg = LIST_HEAD_INITIALIZER(®); |
| 66 | |
| 67 | static bool_t interest_isregistered(const struct poll_interest *i) |
| 68 | { |
| 69 | return !!i->before; |
| 70 | } |
| 71 | |
| 72 | static bool_t finished=False; |
| 73 | |
| 74 | /* Parse the command line options */ |
| 75 | static void parse_options(int argc, char **argv) |
| 76 | { |
| 77 | int c; |
| 78 | |
| 79 | while (True) { |
| 80 | int option_index = 0; |
| 81 | static struct option long_options[] = { |
| 82 | {"verbose", 0, 0, 'v'}, |
| 83 | {"nowarnings", 0, 0, 'w'}, |
| 84 | {"help", 0, 0, 2}, |
| 85 | {"version", 0, 0, 1}, |
| 86 | {"nodetach", 0, 0, 'n'}, |
| 87 | {"managed", 0, 0, 'm'}, |
| 88 | {"silent", 0, 0, 'f'}, |
| 89 | {"quiet", 0, 0, 'f'}, |
| 90 | {"debug", 0, 0, 'd'}, |
| 91 | {"config", 1, 0, 'c'}, |
| 92 | {"just-check-config", 0, 0, 'j'}, |
| 93 | {"sites-key", 1, 0, 's'}, |
| 94 | {0,0,0,0} |
| 95 | }; |
| 96 | |
| 97 | c=getopt_long(argc, argv, "vwdnjc:ft:s:m", |
| 98 | long_options, &option_index); |
| 99 | if (c==-1) |
| 100 | break; |
| 101 | |
| 102 | switch(c) { |
| 103 | case 2: |
| 104 | /* Help */ |
| 105 | printf("Usage: secnet [OPTION]...\n\n" |
| 106 | " -f, --silent, --quiet suppress error messages\n" |
| 107 | " -w, --nowarnings suppress warnings\n" |
| 108 | " -v, --verbose output extra diagnostics\n" |
| 109 | " -c, --config=filename specify a configuration file\n" |
| 110 | " -j, --just-check-config stop after reading " |
| 111 | "configuration file\n" |
| 112 | " -s, --sites-key=name configuration key that " |
| 113 | "specifies active sites\n" |
| 114 | " -n, --nodetach do not run in background\n" |
| 115 | " -m, --managed running under a supervisor\n" |
| 116 | " -d, --debug output debug messages\n" |
| 117 | " --help display this help and exit\n" |
| 118 | " --version output version information " |
| 119 | "and exit\n" |
| 120 | ); |
| 121 | exit(0); |
| 122 | break; |
| 123 | |
| 124 | case 1: |
| 125 | /* Version */ |
| 126 | printf("%s\n",version); |
| 127 | exit(0); |
| 128 | break; |
| 129 | |
| 130 | case 'd': |
| 131 | message_level|=M_DEBUG_CONFIG|M_DEBUG_PHASE|M_DEBUG; |
| 132 | /* fall through */ |
| 133 | case 'v': |
| 134 | message_level|=M_INFO|M_NOTICE|M_WARNING|M_ERR|M_SECURITY| |
| 135 | M_FATAL; |
| 136 | break; |
| 137 | |
| 138 | case 'w': |
| 139 | message_level&=(~M_WARNING); |
| 140 | break; |
| 141 | |
| 142 | case 'f': |
| 143 | message_level=M_FATAL; |
| 144 | break; |
| 145 | |
| 146 | case 'n': |
| 147 | background=False; |
| 148 | break; |
| 149 | |
| 150 | case 'm': |
| 151 | secnet_is_daemon=True; |
| 152 | break; |
| 153 | |
| 154 | case 'c': |
| 155 | if (optarg) |
| 156 | configfile=safe_strdup(optarg,"config_filename"); |
| 157 | else |
| 158 | fatal("secnet: no config filename specified"); |
| 159 | break; |
| 160 | |
| 161 | case 'j': |
| 162 | just_check_config=True; |
| 163 | break; |
| 164 | |
| 165 | case 's': |
| 166 | if (optarg) |
| 167 | sites_key=safe_strdup(optarg,"sites-key"); |
| 168 | else |
| 169 | fatal("secnet: no sites key specified"); |
| 170 | break; |
| 171 | |
| 172 | case '?': |
| 173 | exit(1); |
| 174 | break; |
| 175 | |
| 176 | default: |
| 177 | Message(M_ERR,"secnet: Unknown getopt code %c\n",c); |
| 178 | } |
| 179 | } |
| 180 | |
| 181 | if (argc-optind != 0) { |
| 182 | Message(M_ERR,"secnet: You gave extra command line parameters, " |
| 183 | "which were ignored.\n"); |
| 184 | } |
| 185 | } |
| 186 | |
| 187 | static void setup(dict_t *config) |
| 188 | { |
| 189 | list_t *l; |
| 190 | item_t *site; |
| 191 | dict_t *system; |
| 192 | struct passwd *pw; |
| 193 | struct cloc loc; |
| 194 | int i; |
| 195 | |
| 196 | l=dict_lookup(config,"system"); |
| 197 | |
| 198 | if (!l || list_elem(l,0)->type!=t_dict) { |
| 199 | fatal("configuration does not include a \"system\" dictionary"); |
| 200 | } |
| 201 | system=list_elem(l,0)->data.dict; |
| 202 | loc=list_elem(l,0)->loc; |
| 203 | |
| 204 | /* Arrange systemwide log facility */ |
| 205 | l=dict_lookup(system,"log"); |
| 206 | if (!l) { |
| 207 | fatal("configuration does not include a system/log facility"); |
| 208 | } |
| 209 | system_log=init_log(l); |
| 210 | |
| 211 | /* Who are we supposed to run as? */ |
| 212 | userid=dict_read_string(system,"userid",False,"system",loc); |
| 213 | if (userid) { |
| 214 | if (!(pw=getpwnam(userid))) |
| 215 | fatal("userid \"%s\" not found",userid); |
| 216 | uid=pw->pw_uid; |
| 217 | gid=pw->pw_gid; |
| 218 | } |
| 219 | |
| 220 | /* Pidfile name */ |
| 221 | pidfile=dict_read_string(system,"pidfile",False,"system",loc); |
| 222 | |
| 223 | /* Check whether we need root privileges */ |
| 224 | if (require_root_privileges && uid!=0) { |
| 225 | fatal("the configured feature \"%s\" requires " |
| 226 | "that secnet retain root privileges while running.", |
| 227 | require_root_privileges_explanation); |
| 228 | } |
| 229 | |
| 230 | /* Go along site list, starting sites */ |
| 231 | l=dict_lookup(config,sites_key); |
| 232 | if (!l) { |
| 233 | Message(M_WARNING,"secnet: configuration key \"%s\" is missing; no " |
| 234 | "remote sites are defined\n",sites_key); |
| 235 | } else { |
| 236 | i=0; |
| 237 | while ((site=list_elem(l, i++))) { |
| 238 | struct site_if *s; |
| 239 | if (site->type!=t_closure) { |
| 240 | cfgfatal(site->loc,"system","non-closure in site list"); |
| 241 | } |
| 242 | if (site->data.closure->type!=CL_SITE) { |
| 243 | cfgfatal(site->loc,"system","non-site closure in site list"); |
| 244 | } |
| 245 | s=site->data.closure->interface; |
| 246 | s->control(s->st,True); |
| 247 | } |
| 248 | } |
| 249 | } |
| 250 | |
| 251 | struct poll_interest *register_for_poll(void *st, beforepoll_fn *before, |
| 252 | afterpoll_fn *after, cstring_t desc) |
| 253 | { |
| 254 | struct poll_interest *i; |
| 255 | |
| 256 | NEW(i); |
| 257 | i->before=before; |
| 258 | i->after=after; |
| 259 | i->state=st; |
| 260 | i->nfds=0; |
| 261 | i->desc=desc; |
| 262 | LIST_INSERT_HEAD(®, i, entry); |
| 263 | return i; |
| 264 | } |
| 265 | |
| 266 | void deregister_for_poll(struct poll_interest *i) |
| 267 | { |
| 268 | /* We cannot simply throw this away because we're reentrantly |
| 269 | * inside the main loop, which needs to remember which range of |
| 270 | * fds corresponds to this now-obsolete interest */ |
| 271 | i->before=0; |
| 272 | } |
| 273 | |
| 274 | static void system_phase_hook(void *sst, uint32_t newphase) |
| 275 | { |
| 276 | if (newphase==PHASE_SHUTDOWN && pidfile) { |
| 277 | /* Try to unlink the pidfile; don't care if it fails */ |
| 278 | unlink(pidfile); |
| 279 | } |
| 280 | } |
| 281 | |
| 282 | #if USE_SELECT |
| 283 | static int fakepoll(struct pollfd *fds, int nfds, int timeout) { |
| 284 | fd_set infds[1], outfds[1]; |
| 285 | int maxfd = -1, i, rc; |
| 286 | struct timeval tvtimeout; |
| 287 | FD_ZERO(infds); |
| 288 | FD_ZERO(outfds); |
| 289 | for(i = 0; i < nfds; ++i) { |
| 290 | if(fds[i].events & POLLIN) |
| 291 | FD_SET(fds[i].fd, infds); |
| 292 | if(fds[i].events & POLLOUT) |
| 293 | FD_SET(fds[i].fd, outfds); |
| 294 | if(fds[i].fd > maxfd) |
| 295 | maxfd = fds[i].fd; |
| 296 | } |
| 297 | if(timeout != -1) { |
| 298 | tvtimeout.tv_sec = timeout / 1000; |
| 299 | tvtimeout.tv_usec = 1000 * (timeout % 1000); |
| 300 | } |
| 301 | rc = select(maxfd + 1, infds, outfds, NULL, |
| 302 | timeout == -1 ? NULL : &tvtimeout); |
| 303 | if(rc >= 0) { |
| 304 | for(i = 0; i < nfds; ++i) { |
| 305 | int revents = 0; |
| 306 | if(FD_ISSET(fds[i].fd, infds)) |
| 307 | revents |= POLLIN; |
| 308 | if(FD_ISSET(fds[i].fd, outfds)) |
| 309 | revents |= POLLOUT; |
| 310 | fds[i].revents = revents; |
| 311 | } |
| 312 | } |
| 313 | return rc; |
| 314 | } |
| 315 | #endif |
| 316 | |
| 317 | struct timeval tv_now_global; |
| 318 | uint64_t now_global; |
| 319 | |
| 320 | static void run(void) |
| 321 | { |
| 322 | struct poll_interest *i, *itmp; |
| 323 | int rv, nfds, idx; |
| 324 | int timeout; |
| 325 | struct pollfd *fds=0; |
| 326 | int allocdfds=0, shortfall=0; |
| 327 | |
| 328 | Message(M_NOTICE,"%s [%d]: starting\n",version,secnet_pid); |
| 329 | |
| 330 | do { |
| 331 | if (gettimeofday(&tv_now_global, NULL)!=0) { |
| 332 | fatal_perror("main loop: gettimeofday"); |
| 333 | } |
| 334 | now_global=((uint64_t)tv_now_global.tv_sec*(uint64_t)1000)+ |
| 335 | ((uint64_t)tv_now_global.tv_usec/(uint64_t)1000); |
| 336 | idx=0; |
| 337 | LIST_FOREACH(i, ®, entry) { |
| 338 | int check; |
| 339 | if (interest_isregistered(i)) { |
| 340 | for (check=0; check<i->nfds; check++) { |
| 341 | if(fds[idx+check].revents & POLLNVAL) { |
| 342 | fatal("run: poll (%s#%d) set POLLNVAL", i->desc, check); |
| 343 | } |
| 344 | } |
| 345 | i->after(i->state, fds+idx, i->nfds); |
| 346 | } |
| 347 | idx+=i->nfds; |
| 348 | } |
| 349 | if (shortfall) { |
| 350 | allocdfds *= 2; |
| 351 | allocdfds += shortfall; |
| 352 | REALLOC_ARY(fds,allocdfds); |
| 353 | } |
| 354 | shortfall=0; |
| 355 | idx=0; |
| 356 | timeout=-1; |
| 357 | LIST_FOREACH_SAFE(i, ®, entry, itmp) { |
| 358 | int remain=allocdfds-idx; |
| 359 | nfds=remain; |
| 360 | if (interest_isregistered(i)) { |
| 361 | rv=i->before(i->state, fds+idx, &nfds, &timeout); |
| 362 | if (rv!=0) { |
| 363 | if (rv!=ERANGE) |
| 364 | fatal("run: beforepoll_fn (%s) returns %d",i->desc,rv); |
| 365 | assert(nfds < INT_MAX/4 - shortfall); |
| 366 | shortfall += nfds-remain; |
| 367 | nfds=0; |
| 368 | timeout=0; |
| 369 | } |
| 370 | } else { |
| 371 | nfds=0; |
| 372 | } |
| 373 | if (timeout<-1) { |
| 374 | fatal("run: beforepoll_fn (%s) set timeout to %d", |
| 375 | i->desc,timeout); |
| 376 | } |
| 377 | if (!interest_isregistered(i)) { |
| 378 | /* check this here, rather than earlier, so that we |
| 379 | handle the case where i->before() calls deregister */ |
| 380 | LIST_REMOVE(i, entry); |
| 381 | free(i); |
| 382 | continue; |
| 383 | } |
| 384 | idx+=nfds; |
| 385 | i->nfds=nfds; |
| 386 | } |
| 387 | do { |
| 388 | if (finished) break; |
| 389 | #if USE_SELECT |
| 390 | rv=fakepoll(fds, idx, timeout); |
| 391 | #else |
| 392 | rv=poll(fds, idx, timeout); |
| 393 | #endif |
| 394 | if (rv<0) { |
| 395 | if (errno!=EINTR) { |
| 396 | fatal_perror("run: poll"); |
| 397 | } |
| 398 | } |
| 399 | } while (rv<0); |
| 400 | } while (!finished); |
| 401 | free(fds); |
| 402 | } |
| 403 | |
| 404 | bool_t will_droppriv(void) |
| 405 | { |
| 406 | assert(current_phase >= PHASE_SETUP); |
| 407 | return !!uid; |
| 408 | } |
| 409 | |
| 410 | /* Surrender privileges, if necessary */ |
| 411 | static void droppriv(void) |
| 412 | { |
| 413 | if (userid) { |
| 414 | if (setgid(gid)!=0) |
| 415 | fatal_perror("can't set gid to %ld",(long)gid); |
| 416 | if (initgroups(userid, gid) < 0) |
| 417 | fatal_perror("initgroups"); |
| 418 | if (setuid(uid)!=0) { |
| 419 | fatal_perror("can't set uid to \"%s\"",userid); |
| 420 | } |
| 421 | assert(getuid() == uid); |
| 422 | assert(geteuid() == uid); |
| 423 | assert(getgid() == gid); |
| 424 | assert(getegid() == gid); |
| 425 | } |
| 426 | } |
| 427 | |
| 428 | /* Become a daemon, if necessary */ |
| 429 | static void become_daemon(void) |
| 430 | { |
| 431 | FILE *pf=NULL; |
| 432 | pid_t p; |
| 433 | int errfds[2]; |
| 434 | |
| 435 | add_hook(PHASE_SHUTDOWN,system_phase_hook,NULL); |
| 436 | |
| 437 | /* We only want to become a daemon if we are not one |
| 438 | already */ |
| 439 | if (background && !secnet_is_daemon) { |
| 440 | p=fork(); |
| 441 | if (p>0) { |
| 442 | /* Parent process - just exit */ |
| 443 | _exit(0); |
| 444 | } else if (p==0) { |
| 445 | /* Child process - all done, just carry on */ |
| 446 | secnet_is_daemon=True; |
| 447 | if (setsid() < 0) |
| 448 | fatal_perror("setsid"); |
| 449 | } else { |
| 450 | /* Error */ |
| 451 | fatal_perror("cannot fork"); |
| 452 | exit(1); |
| 453 | } |
| 454 | } |
| 455 | if (secnet_is_daemon) { |
| 456 | /* stderr etc are redirected to the system/log facility */ |
| 457 | pipe_cloexec(errfds); |
| 458 | if (dup2(errfds[1],0) < 0 |
| 459 | || dup2(errfds[1],1) < 0 |
| 460 | || dup2(errfds[1],2) < 0) |
| 461 | fatal_perror("can't dup2 pipe"); |
| 462 | if (close(errfds[1]) < 0) |
| 463 | fatal_perror("can't close redundant pipe endpoint"); |
| 464 | log_from_fd(errfds[0],"stderr",system_log); |
| 465 | } |
| 466 | secnet_pid=getpid(); |
| 467 | |
| 468 | /* Now we can write the pidfile */ |
| 469 | if (pidfile) { |
| 470 | pf=fopen(pidfile,"w"); |
| 471 | if (!pf) { |
| 472 | fatal_perror("cannot open pidfile \"%s\"",pidfile); |
| 473 | } |
| 474 | if (fprintf(pf,"%ld\n",(long)secnet_pid) < 0 |
| 475 | || fclose(pf) < 0) |
| 476 | fatal_perror("cannot write to pidfile \"%s\"",pidfile); |
| 477 | } |
| 478 | } |
| 479 | |
| 480 | static signal_notify_fn finish,ignore_hup; |
| 481 | static void finish(void *st, int signum) |
| 482 | { |
| 483 | finished=True; |
| 484 | Message(M_NOTICE,"%s [%d]: received %s\n",version,secnet_pid,(string_t)st); |
| 485 | } |
| 486 | static void ignore_hup(void *st, int signum) |
| 487 | { |
| 488 | Message(M_INFO,"%s [%d]: received SIGHUP\n",version,secnet_pid); |
| 489 | return; |
| 490 | } |
| 491 | |
| 492 | int main(int argc, char **argv) |
| 493 | { |
| 494 | dict_t *config; |
| 495 | |
| 496 | phase_hooks_init(); |
| 497 | |
| 498 | enter_phase(PHASE_GETOPTS); |
| 499 | parse_options(argc,argv); |
| 500 | |
| 501 | enter_phase(PHASE_READCONFIG); |
| 502 | config=read_conffile(configfile); |
| 503 | |
| 504 | enter_phase(PHASE_SETUP); |
| 505 | setup(config); |
| 506 | |
| 507 | if (just_check_config) { |
| 508 | Message(M_INFO,"configuration file check complete\n"); |
| 509 | exit(0); |
| 510 | } |
| 511 | |
| 512 | enter_phase(PHASE_DAEMONIZE); |
| 513 | become_daemon(); |
| 514 | |
| 515 | enter_phase(PHASE_GETRESOURCES); |
| 516 | /* Appropriate phase hooks will have been run */ |
| 517 | |
| 518 | enter_phase(PHASE_DROPPRIV); |
| 519 | droppriv(); |
| 520 | |
| 521 | start_signal_handling(); |
| 522 | request_signal_notification(SIGTERM,finish,safe_strdup("SIGTERM","run")); |
| 523 | if (!background) request_signal_notification(SIGINT,finish, |
| 524 | safe_strdup("SIGINT","run")); |
| 525 | request_signal_notification(SIGHUP,ignore_hup,NULL); |
| 526 | enter_phase(PHASE_RUN); |
| 527 | run(); |
| 528 | |
| 529 | enter_phase(PHASE_SHUTDOWN); |
| 530 | Message(M_NOTICE,"%s [%d]: finished\n",version,secnet_pid); |
| 531 | |
| 532 | return 0; |
| 533 | } |