1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright 2007 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 #pragma ident "%Z%%M% %I% %E% SMI" 27 28 /* 29 * fork.c - safe forking for svc.startd 30 * 31 * fork_configd() and fork_sulogin() are related, special cases that handle the 32 * spawning of specific client processes for svc.startd. 33 */ 34 35 #include <sys/contract/process.h> 36 #include <sys/corectl.h> 37 #include <sys/ctfs.h> 38 #include <sys/stat.h> 39 #include <sys/types.h> 40 #include <sys/uio.h> 41 #include <sys/wait.h> 42 #include <assert.h> 43 #include <errno.h> 44 #include <fcntl.h> 45 #include <libcontract.h> 46 #include <libcontract_priv.h> 47 #include <limits.h> 48 #include <port.h> 49 #include <signal.h> 50 #include <stdarg.h> 51 #include <stdio.h> 52 #include <stdlib.h> 53 #include <string.h> 54 #include <unistd.h> 55 #include <utmpx.h> 56 57 #include "configd_exit.h" 58 #include "protocol.h" 59 #include "startd.h" 60 61 static struct utmpx *utmpp; /* pointer for getutxent() */ 62 63 pid_t 64 startd_fork1(int *forkerr) 65 { 66 pid_t p; 67 68 /* 69 * prefork stack 70 */ 71 wait_prefork(); 72 73 p = fork1(); 74 75 if (p == -1 && forkerr != NULL) 76 *forkerr = errno; 77 78 /* 79 * postfork stack 80 */ 81 wait_postfork(p); 82 83 return (p); 84 } 85 86 /* 87 * void fork_mount(char *, char *) 88 * Run mount(1M) with the given options and mount point. (mount(1M) has much 89 * hidden knowledge; it's much less correct to reimplement that logic here to 90 * save a fork(2)/exec(2) invocation.) 91 */ 92 int 93 fork_mount(char *path, char *opts) 94 { 95 pid_t pid; 96 uint_t tries = 0; 97 int status; 98 99 for (pid = fork1(); pid == -1; pid = fork1()) { 100 if (++tries > MAX_MOUNT_RETRIES) 101 return (-1); 102 103 (void) sleep(tries); 104 } 105 106 if (pid != 0) { 107 (void) waitpid(pid, &status, 0); 108 109 /* 110 * If our mount(1M) invocation exited by peculiar means, or with 111 * a non-zero status, our mount likelihood is low. 112 */ 113 if (!WIFEXITED(status) || 114 WEXITSTATUS(status) != 0) 115 return (-1); 116 117 return (0); 118 } 119 120 (void) execl("/sbin/mount", "mount", "-o", opts, path, NULL); 121 122 return (-1); 123 } 124 125 /* 126 * pid_t fork_common(...) 127 * Common routine used by fork_sulogin and fork_configd to fork a 128 * process in a contract with the provided terms. Invokes 129 * fork_sulogin (with its no-fork argument set) on errors. 130 */ 131 static pid_t 132 fork_common(const char *name, int retries, ctid_t *ctidp, 133 uint_t inf, uint_t crit, uint_t fatal, uint_t param, uint64_t cookie) 134 { 135 uint_t tries = 0; 136 int ctfd, err; 137 pid_t pid; 138 139 /* 140 * Establish process contract terms. 141 */ 142 if ((ctfd = open64(CTFS_ROOT "/process/template", O_RDWR)) == -1) { 143 fork_sulogin(B_TRUE, "Could not open process contract template " 144 "for %s: %s\n", name, strerror(errno)); 145 /* NOTREACHED */ 146 } 147 148 err = ct_tmpl_set_critical(ctfd, crit); 149 err |= ct_pr_tmpl_set_fatal(ctfd, fatal); 150 err |= ct_tmpl_set_informative(ctfd, inf); 151 err |= ct_pr_tmpl_set_param(ctfd, param); 152 err |= ct_tmpl_set_cookie(ctfd, cookie); 153 if (err) { 154 (void) close(ctfd); 155 fork_sulogin(B_TRUE, "Could not set %s process contract " 156 "terms\n", name); 157 /* NOTREACHED */ 158 } 159 160 if (err = ct_tmpl_activate(ctfd)) { 161 (void) close(ctfd); 162 fork_sulogin(B_TRUE, "Could not activate %s process contract " 163 "template: %s\n", name, strerror(err)); 164 /* NOTREACHED */ 165 } 166 167 /* 168 * Attempt to fork "retries" times. 169 */ 170 for (pid = fork1(); pid == -1; pid = fork1()) { 171 if (++tries > retries) { 172 /* 173 * When we exit the sulogin session, init(1M) 174 * will restart svc.startd(1M). 175 */ 176 err = errno; 177 (void) ct_tmpl_clear(ctfd); 178 (void) close(ctfd); 179 fork_sulogin(B_TRUE, "Could not fork to start %s: %s\n", 180 name, strerror(err)); 181 /* NOTREACHED */ 182 } 183 (void) sleep(tries); 184 } 185 186 /* 187 * Clean up, return pid and ctid. 188 */ 189 if (pid != 0 && (errno = contract_latest(ctidp)) != 0) 190 uu_die("Could not get new contract id for %s\n", name); 191 (void) ct_tmpl_clear(ctfd); 192 (void) close(ctfd); 193 194 return (pid); 195 } 196 197 /* 198 * void fork_sulogin(boolean_t, const char *, ...) 199 * When we are invoked with the -s flag from boot (or run into an unfixable 200 * situation), we run a private copy of sulogin. When the sulogin session 201 * is ended, we continue. This is the last fallback action for system 202 * maintenance. 203 * 204 * If immediate is true, fork_sulogin() executes sulogin(1M) directly, without 205 * forking. 206 * 207 * Because fork_sulogin() is needed potentially before we daemonize, we leave 208 * it outside the wait_register() framework. 209 */ 210 /*PRINTFLIKE2*/ 211 void 212 fork_sulogin(boolean_t immediate, const char *format, ...) 213 { 214 va_list args; 215 int i, fd_console; 216 217 (void) printf("Requesting System Maintenance Mode\n"); 218 219 if (!booting_to_single_user) 220 (void) printf("(See /lib/svc/share/README for more " 221 "information.)\n"); 222 223 va_start(args, format); 224 (void) vprintf(format, args); 225 va_end(args); 226 227 if (!immediate) { 228 ctid_t ctid; 229 pid_t pid; 230 231 pid = fork_common("sulogin", MAX_SULOGIN_RETRIES, &ctid, 232 CT_PR_EV_HWERR, 0, CT_PR_EV_HWERR, CT_PR_PGRPONLY, 233 SULOGIN_COOKIE); 234 235 if (pid != 0) { 236 (void) waitpid(pid, NULL, 0); 237 contract_abandon(ctid); 238 return; 239 } 240 /* close all inherited fds */ 241 closefrom(0); 242 } else { 243 (void) printf("Directly executing sulogin.\n"); 244 /* 245 * Can't call closefrom() in this MT section 246 * so safely close a minimum set of fds. 247 */ 248 for (i = 0; i < 3; i++) 249 (void) close(i); 250 } 251 252 (void) setpgrp(); 253 254 /* open the console for sulogin */ 255 if ((fd_console = open("/dev/console", O_RDWR)) >= 0) { 256 if (fd_console != STDIN_FILENO) 257 while (dup2(fd_console, STDIN_FILENO) < 0 && 258 errno == EINTR) 259 ; 260 if (fd_console != STDOUT_FILENO) 261 while (dup2(fd_console, STDOUT_FILENO) < 0 && 262 errno == EINTR) 263 ; 264 if (fd_console != STDERR_FILENO) 265 while (dup2(fd_console, STDERR_FILENO) < 0 && 266 errno == EINTR) 267 ; 268 if (fd_console > 2) 269 (void) close(fd_console); 270 } 271 272 setutxent(); 273 while ((utmpp = getutxent()) != NULL) { 274 if (strcmp(utmpp->ut_user, "LOGIN") != 0) { 275 if (strcmp(utmpp->ut_line, "console") == 0) { 276 (void) kill(utmpp->ut_pid, 9); 277 break; 278 } 279 } 280 } 281 282 (void) execl("/sbin/sulogin", "sulogin", NULL); 283 284 uu_warn("Could not exec() sulogin"); 285 286 exit(1); 287 } 288 289 #define CONFIGD_PATH "/lib/svc/bin/svc.configd" 290 291 /* 292 * void fork_configd(int status) 293 * We are interested in exit events (since the parent's exiting means configd 294 * is ready to run and since the child's exiting indicates an error case) and 295 * in empty events. This means we have a unique template for initiating 296 * configd. 297 */ 298 /*ARGSUSED*/ 299 void 300 fork_configd(int exitstatus) 301 { 302 pid_t pid; 303 ctid_t ctid = -1; 304 int err; 305 char path[PATH_MAX]; 306 307 retry: 308 log_framework(LOG_DEBUG, "fork_configd trying to start svc.configd\n"); 309 310 /* 311 * If we're retrying, we will have an old contract lying around 312 * from the failure. Since we're going to be creating a new 313 * contract shortly, we abandon the old one now. 314 */ 315 if (ctid != -1) 316 contract_abandon(ctid); 317 ctid = -1; 318 319 pid = fork_common("svc.configd", MAX_CONFIGD_RETRIES, &ctid, 320 0, CT_PR_EV_EXIT, 0, CT_PR_INHERIT | CT_PR_REGENT, CONFIGD_COOKIE); 321 322 if (pid != 0) { 323 int exitstatus; 324 325 st->st_configd_pid = pid; 326 327 if (waitpid(pid, &exitstatus, 0) == -1) { 328 fork_sulogin(B_FALSE, "waitpid on svc.configd " 329 "failed: %s\n", strerror(errno)); 330 } else if (WIFEXITED(exitstatus)) { 331 char *errstr; 332 333 /* 334 * Examine exitstatus. This will eventually get more 335 * complicated, as we will want to teach startd how to 336 * invoke configd with alternate repositories, etc. 337 * 338 * Note that exec(2) failure results in an exit status 339 * of 1, resulting in the default clause below. 340 */ 341 342 /* 343 * Assign readable strings to cases we don't handle, or 344 * have error outcomes that cannot be eliminated. 345 */ 346 switch (WEXITSTATUS(exitstatus)) { 347 case CONFIGD_EXIT_BAD_ARGS: 348 errstr = "bad arguments"; 349 break; 350 351 case CONFIGD_EXIT_DATABASE_BAD: 352 errstr = "database corrupt"; 353 break; 354 355 case CONFIGD_EXIT_DATABASE_LOCKED: 356 errstr = "database locked"; 357 break; 358 case CONFIGD_EXIT_INIT_FAILED: 359 errstr = "initialization failure"; 360 break; 361 case CONFIGD_EXIT_DOOR_INIT_FAILED: 362 errstr = "door initialization failure"; 363 break; 364 case CONFIGD_EXIT_DATABASE_INIT_FAILED: 365 errstr = "database initialization failure"; 366 break; 367 case CONFIGD_EXIT_NO_THREADS: 368 errstr = "no threads available"; 369 break; 370 case CONFIGD_EXIT_LOST_MAIN_DOOR: 371 errstr = "lost door server attachment"; 372 break; 373 case 1: 374 errstr = "execution failure"; 375 break; 376 default: 377 errstr = "unknown error"; 378 break; 379 } 380 381 /* 382 * Remedial actions for various configd failures. 383 */ 384 switch (WEXITSTATUS(exitstatus)) { 385 case CONFIGD_EXIT_OKAY: 386 break; 387 388 case CONFIGD_EXIT_DATABASE_LOCKED: 389 /* attempt remount of / read-write */ 390 if (fs_is_read_only("/", NULL) == 1) { 391 if (fs_remount("/") == -1) 392 fork_sulogin(B_FALSE, 393 "remount of root " 394 "filesystem failed\n"); 395 396 goto retry; 397 } 398 break; 399 400 default: 401 fork_sulogin(B_FALSE, "svc.configd exited " 402 "with status %d (%s)\n", 403 WEXITSTATUS(exitstatus), errstr); 404 goto retry; 405 } 406 } else if (WIFSIGNALED(exitstatus)) { 407 char signame[SIG2STR_MAX]; 408 409 if (sig2str(WTERMSIG(exitstatus), signame)) 410 (void) snprintf(signame, SIG2STR_MAX, 411 "signum %d", WTERMSIG(exitstatus)); 412 413 fork_sulogin(B_FALSE, "svc.configd signalled:" 414 " %s\n", signame); 415 416 goto retry; 417 } else { 418 fork_sulogin(B_FALSE, "svc.configd non-exit " 419 "condition: 0x%x\n", exitstatus); 420 421 goto retry; 422 } 423 424 /* 425 * Announce that we have a valid svc.configd status. 426 */ 427 MUTEX_LOCK(&st->st_configd_live_lock); 428 st->st_configd_lives = 1; 429 err = pthread_cond_broadcast(&st->st_configd_live_cv); 430 assert(err == 0); 431 MUTEX_UNLOCK(&st->st_configd_live_lock); 432 433 log_framework(LOG_DEBUG, "fork_configd broadcasts configd is " 434 "live\n"); 435 return; 436 } 437 438 /* 439 * Set our per-process core file path to leave core files in 440 * /etc/svc/volatile directory, named after the PID to aid in debugging. 441 */ 442 (void) snprintf(path, sizeof (path), 443 "/etc/svc/volatile/core.configd.%%p"); 444 445 (void) core_set_process_path(path, strlen(path) + 1, getpid()); 446 447 log_framework(LOG_DEBUG, "executing svc.configd\n"); 448 449 (void) execl(CONFIGD_PATH, CONFIGD_PATH, NULL); 450 451 /* 452 * Status code is used above to identify configd exec failure. 453 */ 454 exit(1); 455 } 456 457 void * 458 fork_configd_thread(void *vctid) 459 { 460 int fd, err; 461 ctid_t configd_ctid = (ctid_t)vctid; 462 463 if (configd_ctid == -1) { 464 log_framework(LOG_DEBUG, 465 "fork_configd_thread starting svc.configd\n"); 466 fork_configd(0); 467 } else { 468 /* 469 * configd_ctid is known: we broadcast and continue. 470 * test contract for appropriate state by verifying that 471 * there is one or more processes within it? 472 */ 473 log_framework(LOG_DEBUG, 474 "fork_configd_thread accepting svc.configd with CTID %ld\n", 475 configd_ctid); 476 MUTEX_LOCK(&st->st_configd_live_lock); 477 st->st_configd_lives = 1; 478 (void) pthread_cond_broadcast(&st->st_configd_live_cv); 479 MUTEX_UNLOCK(&st->st_configd_live_lock); 480 } 481 482 fd = open64(CTFS_ROOT "/process/pbundle", O_RDONLY); 483 if (fd == -1) 484 uu_die("process bundle open failed"); 485 486 /* 487 * Make sure we get all events (including those generated by configd 488 * before this thread was started). 489 */ 490 err = ct_event_reset(fd); 491 assert(err == 0); 492 493 for (;;) { 494 int efd, sfd; 495 ct_evthdl_t ev; 496 uint32_t type; 497 ctevid_t evid; 498 ct_stathdl_t status; 499 ctid_t ctid; 500 uint64_t cookie; 501 pid_t pid; 502 503 if (err = ct_event_read_critical(fd, &ev)) { 504 assert(err != EINVAL && err != EAGAIN); 505 log_error(LOG_WARNING, 506 "Error reading next contract event: %s", 507 strerror(err)); 508 continue; 509 } 510 511 evid = ct_event_get_evid(ev); 512 ctid = ct_event_get_ctid(ev); 513 type = ct_event_get_type(ev); 514 515 /* Fetch cookie. */ 516 sfd = contract_open(ctid, "process", "status", O_RDONLY); 517 if (sfd < 0) { 518 ct_event_free(ev); 519 continue; 520 } 521 522 if (err = ct_status_read(sfd, CTD_COMMON, &status)) { 523 log_framework(LOG_WARNING, "Could not get status for " 524 "contract %ld: %s\n", ctid, strerror(err)); 525 526 ct_event_free(ev); 527 startd_close(sfd); 528 continue; 529 } 530 531 cookie = ct_status_get_cookie(status); 532 533 ct_status_free(status); 534 535 startd_close(sfd); 536 537 /* 538 * Don't process events from contracts we aren't interested in. 539 */ 540 if (cookie != CONFIGD_COOKIE) { 541 ct_event_free(ev); 542 continue; 543 } 544 545 if (type == CT_PR_EV_EXIT) { 546 int exitstatus; 547 548 (void) ct_pr_event_get_pid(ev, &pid); 549 (void) ct_pr_event_get_exitstatus(ev, 550 &exitstatus); 551 552 if (st->st_configd_pid != pid) { 553 /* 554 * This is the child exiting, so we 555 * abandon the contract and restart 556 * configd. 557 */ 558 contract_abandon(ctid); 559 fork_configd(exitstatus); 560 } 561 } 562 563 efd = contract_open(ctid, "process", "ctl", O_WRONLY); 564 if (efd != -1) { 565 (void) ct_ctl_ack(efd, evid); 566 startd_close(efd); 567 } 568 569 ct_event_free(ev); 570 571 } 572 573 /*NOTREACHED*/ 574 return (NULL); 575 } 576 577 void 578 fork_rc_script(char rl, const char *arg, boolean_t wait) 579 { 580 pid_t pid; 581 int tmpl, err, stat; 582 char path[20] = "/sbin/rc.", log[20] = "rc..log", timebuf[20]; 583 time_t now; 584 struct tm ltime; 585 size_t sz; 586 char *pathenv; 587 char **nenv; 588 589 path[8] = rl; 590 591 tmpl = open64(CTFS_ROOT "/process/template", O_RDWR); 592 if (tmpl >= 0) { 593 err = ct_tmpl_set_critical(tmpl, 0); 594 assert(err == 0); 595 596 err = ct_tmpl_set_informative(tmpl, 0); 597 assert(err == 0); 598 599 err = ct_pr_tmpl_set_fatal(tmpl, 0); 600 assert(err == 0); 601 602 err = ct_tmpl_activate(tmpl); 603 assert(err == 0); 604 605 err = close(tmpl); 606 assert(err == 0); 607 } else { 608 uu_warn("Could not create contract template for %s.\n", path); 609 } 610 611 pid = startd_fork1(NULL); 612 if (pid < 0) { 613 return; 614 } else if (pid != 0) { 615 /* parent */ 616 if (wait) { 617 do 618 err = waitpid(pid, &stat, 0); 619 while (err != 0 && errno == EINTR) 620 ; 621 622 if (!WIFEXITED(stat)) { 623 log_framework(LOG_INFO, 624 "%s terminated with waitpid() status %d.\n", 625 path, stat); 626 } else if (WEXITSTATUS(stat) != 0) { 627 log_framework(LOG_INFO, 628 "%s failed with status %d.\n", path, 629 WEXITSTATUS(stat)); 630 } 631 } 632 633 return; 634 } 635 636 /* child */ 637 638 log[2] = rl; 639 640 setlog(log); 641 642 now = time(NULL); 643 sz = strftime(timebuf, sizeof (timebuf), "%b %e %T", 644 localtime_r(&now, <ime)); 645 assert(sz != 0); 646 647 (void) fprintf(stderr, "%s Executing %s %s\n", timebuf, path, arg); 648 649 if (rl == 'S') 650 pathenv = "PATH=/sbin:/usr/sbin:/usr/bin"; 651 else 652 pathenv = "PATH=/usr/sbin:/usr/bin"; 653 654 nenv = set_smf_env(NULL, 0, pathenv, NULL, NULL); 655 656 (void) execle(path, path, arg, 0, nenv); 657 658 perror("exec"); 659 exit(0); 660 } 661