1 /* $OpenBSD: proc.c,v 1.22 2015/01/16 06:39:58 deraadt Exp $ */ 2 3 /* 4 * Copyright (c) 2010 - 2014 Reyk Floeter <reyk@openbsd.org> 5 * Copyright (c) 2008 Pierre-Yves Ritschard <pyr@openbsd.org> 6 * 7 * Permission to use, copy, modify, and distribute this software for any 8 * purpose with or without fee is hereby granted, provided that the above 9 * copyright notice and this permission notice appear in all copies. 10 * 11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 17 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 18 */ 19 20 #include <sys/queue.h> 21 #include <sys/socket.h> 22 #include <sys/wait.h> 23 #include <sys/tree.h> 24 25 #include <net/if.h> 26 #include <netinet/in.h> 27 #include <netinet/ip.h> 28 #include <arpa/inet.h> 29 30 #include <stdio.h> 31 #include <stdlib.h> 32 #include <unistd.h> 33 #include <string.h> 34 #include <errno.h> 35 #include <signal.h> 36 #include <pwd.h> 37 #include <event.h> 38 39 #include "iked.h" 40 41 void proc_open(struct privsep *, struct privsep_proc *, 42 struct privsep_proc *, size_t); 43 void proc_close(struct privsep *); 44 int proc_ispeer(struct privsep_proc *, u_int, enum privsep_procid); 45 void proc_shutdown(struct privsep_proc *); 46 void proc_sig_handler(int, short, void *); 47 void proc_range(struct privsep *, enum privsep_procid, int *, int *); 48 49 int 50 proc_ispeer(struct privsep_proc *procs, u_int nproc, enum privsep_procid type) 51 { 52 u_int i; 53 54 for (i = 0; i < nproc; i++) 55 if (procs[i].p_id == type) 56 return (1); 57 return (0); 58 } 59 60 void 61 proc_init(struct privsep *ps, struct privsep_proc *procs, u_int nproc) 62 { 63 u_int i, j, src, dst; 64 struct privsep_pipes *pp; 65 66 /* 67 * Allocate pipes for all process instances (incl. parent) 68 * 69 * - ps->ps_pipes: N:M mapping 70 * N source processes connected to M destination processes: 71 * [src][instances][dst][instances], for example 72 * [PROC_RELAY][3][PROC_CA][3] 73 * 74 * - ps->ps_pp: per-process 1:M part of ps->ps_pipes 75 * Each process instance has a destination array of socketpair fds: 76 * [dst][instances], for example 77 * [PROC_PARENT][0] 78 */ 79 for (src = 0; src < PROC_MAX; src++) { 80 /* Allocate destination array for each process */ 81 if ((ps->ps_pipes[src] = calloc(ps->ps_ninstances, 82 sizeof(struct privsep_pipes))) == NULL) 83 fatal("proc_init: calloc"); 84 85 for (i = 0; i < ps->ps_ninstances; i++) { 86 pp = &ps->ps_pipes[src][i]; 87 88 for (dst = 0; dst < PROC_MAX; dst++) { 89 /* Allocate maximum fd integers */ 90 if ((pp->pp_pipes[dst] = 91 calloc(ps->ps_ninstances, 92 sizeof(int))) == NULL) 93 fatal("proc_init: calloc"); 94 95 /* Mark fd as unused */ 96 for (j = 0; j < ps->ps_ninstances; j++) 97 pp->pp_pipes[dst][j] = -1; 98 } 99 } 100 } 101 102 /* 103 * Setup and run the parent and its children 104 */ 105 privsep_process = PROC_PARENT; 106 ps->ps_instances[PROC_PARENT] = 1; 107 ps->ps_title[PROC_PARENT] = "parent"; 108 ps->ps_pid[PROC_PARENT] = getpid(); 109 ps->ps_pp = &ps->ps_pipes[privsep_process][0]; 110 111 for (i = 0; i < nproc; i++) { 112 /* Default to 1 process instance */ 113 if (ps->ps_instances[procs[i].p_id] < 1) 114 ps->ps_instances[procs[i].p_id] = 1; 115 ps->ps_title[procs[i].p_id] = procs[i].p_title; 116 } 117 118 proc_open(ps, NULL, procs, nproc); 119 120 /* Engage! */ 121 for (i = 0; i < nproc; i++) 122 ps->ps_pid[procs[i].p_id] = (*procs[i].p_init)(ps, &procs[i]); 123 } 124 125 void 126 proc_kill(struct privsep *ps) 127 { 128 pid_t pid; 129 u_int i; 130 131 if (privsep_process != PROC_PARENT) 132 return; 133 134 for (i = 0; i < PROC_MAX; i++) { 135 if (ps->ps_pid[i] == 0) 136 continue; 137 killpg(ps->ps_pid[i], SIGTERM); 138 } 139 140 do { 141 pid = waitpid(WAIT_ANY, NULL, 0); 142 } while (pid != -1 || (pid == -1 && errno == EINTR)); 143 144 proc_close(ps); 145 } 146 147 void 148 proc_open(struct privsep *ps, struct privsep_proc *p, 149 struct privsep_proc *procs, size_t nproc) 150 { 151 struct privsep_pipes *pa, *pb; 152 int fds[2]; 153 u_int i, j, src, proc; 154 155 if (p == NULL) 156 src = privsep_process; /* parent */ 157 else 158 src = p->p_id; 159 160 /* 161 * Open socket pairs for our peers 162 */ 163 for (proc = 0; proc < nproc; proc++) { 164 procs[proc].p_ps = ps; 165 procs[proc].p_env = ps->ps_env; 166 167 for (i = 0; i < ps->ps_instances[src]; i++) { 168 for (j = 0; j < ps->ps_instances[procs[proc].p_id]; 169 j++) { 170 pa = &ps->ps_pipes[src][i]; 171 pb = &ps->ps_pipes[procs[proc].p_id][j]; 172 173 /* Check if fds are already set by peer */ 174 if (pa->pp_pipes[procs[proc].p_id][j] != -1) 175 continue; 176 177 if (socketpair(AF_UNIX, SOCK_STREAM, 178 PF_UNSPEC, fds) == -1) 179 fatal("socketpair"); 180 181 socket_set_blockmode(fds[0], BM_NONBLOCK); 182 socket_set_blockmode(fds[1], BM_NONBLOCK); 183 184 pa->pp_pipes[procs[proc].p_id][j] = fds[0]; 185 pb->pp_pipes[src][i] = fds[1]; 186 } 187 } 188 } 189 } 190 191 void 192 proc_listen(struct privsep *ps, struct privsep_proc *procs, size_t nproc) 193 { 194 u_int i, dst, src, n, m; 195 struct privsep_pipes *pp; 196 197 /* 198 * Close unused pipes 199 */ 200 for (src = 0; src < PROC_MAX; src++) { 201 for (n = 0; n < ps->ps_instances[src]; n++) { 202 /* Ingore current process */ 203 if (src == (u_int)privsep_process && 204 n == ps->ps_instance) 205 continue; 206 207 pp = &ps->ps_pipes[src][n]; 208 209 for (dst = 0; dst < PROC_MAX; dst++) { 210 if (src == dst) 211 continue; 212 for (m = 0; m < ps->ps_instances[dst]; m++) { 213 if (pp->pp_pipes[dst][m] == -1) 214 continue; 215 216 /* Close and invalidate fd */ 217 close(pp->pp_pipes[dst][m]); 218 pp->pp_pipes[dst][m] = -1; 219 } 220 } 221 } 222 } 223 224 src = privsep_process; 225 ps->ps_pp = pp = &ps->ps_pipes[src][ps->ps_instance]; 226 227 /* 228 * Listen on appropriate pipes 229 */ 230 for (i = 0; i < nproc; i++) { 231 dst = procs[i].p_id; 232 233 if (src == dst) 234 fatal("proc_listen: cannot peer with oneself"); 235 236 if ((ps->ps_ievs[dst] = calloc(ps->ps_instances[dst], 237 sizeof(struct imsgev))) == NULL) 238 fatal("proc_open"); 239 240 for (n = 0; n < ps->ps_instances[dst]; n++) { 241 if (pp->pp_pipes[dst][n] == -1) 242 continue; 243 244 imsg_init(&(ps->ps_ievs[dst][n].ibuf), 245 pp->pp_pipes[dst][n]); 246 ps->ps_ievs[dst][n].handler = proc_dispatch; 247 ps->ps_ievs[dst][n].events = EV_READ; 248 ps->ps_ievs[dst][n].proc = &procs[i]; 249 ps->ps_ievs[dst][n].data = &ps->ps_ievs[dst][n]; 250 procs[i].p_instance = n; 251 252 event_set(&(ps->ps_ievs[dst][n].ev), 253 ps->ps_ievs[dst][n].ibuf.fd, 254 ps->ps_ievs[dst][n].events, 255 ps->ps_ievs[dst][n].handler, 256 ps->ps_ievs[dst][n].data); 257 event_add(&(ps->ps_ievs[dst][n].ev), NULL); 258 } 259 } 260 } 261 262 void 263 proc_close(struct privsep *ps) 264 { 265 u_int dst, n; 266 struct privsep_pipes *pp; 267 268 if (ps == NULL) 269 return; 270 271 pp = ps->ps_pp; 272 273 for (dst = 0; dst < PROC_MAX; dst++) { 274 if (ps->ps_ievs[dst] == NULL) 275 continue; 276 277 for (n = 0; n < ps->ps_instances[dst]; n++) { 278 if (pp->pp_pipes[dst][n] == -1) 279 continue; 280 281 /* Cancel the fd, close and invalidate the fd */ 282 event_del(&(ps->ps_ievs[dst][n].ev)); 283 imsg_clear(&(ps->ps_ievs[dst][n].ibuf)); 284 close(pp->pp_pipes[dst][n]); 285 pp->pp_pipes[dst][n] = -1; 286 } 287 free(ps->ps_ievs[dst]); 288 } 289 } 290 291 void 292 proc_shutdown(struct privsep_proc *p) 293 { 294 struct privsep *ps = p->p_ps; 295 296 if (p->p_id == PROC_CONTROL && ps) 297 control_cleanup(&ps->ps_csock); 298 299 if (p->p_shutdown != NULL) 300 (*p->p_shutdown)(); 301 302 proc_close(ps); 303 304 log_info("%s exiting, pid %d", p->p_title, getpid()); 305 306 _exit(0); 307 } 308 309 void 310 proc_sig_handler(int sig, short event, void *arg) 311 { 312 struct privsep_proc *p = arg; 313 314 switch (sig) { 315 case SIGINT: 316 case SIGTERM: 317 proc_shutdown(p); 318 break; 319 case SIGCHLD: 320 case SIGHUP: 321 case SIGPIPE: 322 case SIGUSR1: 323 /* ignore */ 324 break; 325 default: 326 fatalx("proc_sig_handler: unexpected signal"); 327 /* NOTREACHED */ 328 } 329 } 330 331 pid_t 332 proc_run(struct privsep *ps, struct privsep_proc *p, 333 struct privsep_proc *procs, u_int nproc, 334 void (*init)(struct privsep *, struct privsep_proc *, void *), void *arg) 335 { 336 pid_t pid; 337 struct passwd *pw; 338 const char *root; 339 struct control_sock *rcs; 340 u_int n; 341 342 if (ps->ps_noaction) 343 return (0); 344 345 proc_open(ps, p, procs, nproc); 346 347 /* Fork child handlers */ 348 switch (pid = fork()) { 349 case -1: 350 fatal("proc_run: cannot fork"); 351 case 0: 352 /* Set the process group of the current process */ 353 setpgid(0, 0); 354 break; 355 default: 356 return (pid); 357 } 358 359 pw = ps->ps_pw; 360 361 if (p->p_id == PROC_CONTROL && ps->ps_instance == 0) { 362 if (control_init(ps, &ps->ps_csock) == -1) 363 fatalx(p->p_title); 364 TAILQ_FOREACH(rcs, &ps->ps_rcsocks, cs_entry) 365 if (control_init(ps, rcs) == -1) 366 fatalx(p->p_title); 367 } 368 369 /* Change root directory */ 370 if (p->p_chroot != NULL) 371 root = p->p_chroot; 372 else 373 root = pw->pw_dir; 374 375 if (chroot(root) == -1) 376 fatal("proc_run: chroot"); 377 if (chdir("/") == -1) 378 fatal("proc_run: chdir(\"/\")"); 379 380 privsep_process = p->p_id; 381 382 setproctitle("%s", p->p_title); 383 384 if (setgroups(1, &pw->pw_gid) || 385 setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) || 386 setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid)) 387 fatal("proc_run: cannot drop privileges"); 388 389 /* Fork child handlers */ 390 for (n = 1; n < ps->ps_instances[p->p_id]; n++) { 391 if (fork() == 0) { 392 ps->ps_instance = p->p_instance = n; 393 break; 394 } 395 } 396 397 #ifdef DEBUG 398 log_debug("%s: %s %d/%d, pid %d", __func__, p->p_title, 399 ps->ps_instance + 1, ps->ps_instances[p->p_id], getpid()); 400 #endif 401 402 event_init(); 403 404 signal_set(&ps->ps_evsigint, SIGINT, proc_sig_handler, p); 405 signal_set(&ps->ps_evsigterm, SIGTERM, proc_sig_handler, p); 406 signal_set(&ps->ps_evsigchld, SIGCHLD, proc_sig_handler, p); 407 signal_set(&ps->ps_evsighup, SIGHUP, proc_sig_handler, p); 408 signal_set(&ps->ps_evsigpipe, SIGPIPE, proc_sig_handler, p); 409 signal_set(&ps->ps_evsigusr1, SIGUSR1, proc_sig_handler, p); 410 411 signal_add(&ps->ps_evsigint, NULL); 412 signal_add(&ps->ps_evsigterm, NULL); 413 signal_add(&ps->ps_evsigchld, NULL); 414 signal_add(&ps->ps_evsighup, NULL); 415 signal_add(&ps->ps_evsigpipe, NULL); 416 signal_add(&ps->ps_evsigusr1, NULL); 417 418 proc_listen(ps, procs, nproc); 419 420 if (p->p_id == PROC_CONTROL && ps->ps_instance == 0) { 421 TAILQ_INIT(&ctl_conns); 422 if (control_listen(&ps->ps_csock) == -1) 423 fatalx(p->p_title); 424 TAILQ_FOREACH(rcs, &ps->ps_rcsocks, cs_entry) 425 if (control_listen(rcs) == -1) 426 fatalx(p->p_title); 427 } 428 429 if (init != NULL) 430 init(ps, p, arg); 431 432 event_dispatch(); 433 434 proc_shutdown(p); 435 436 return (0); 437 } 438 439 void 440 proc_dispatch(int fd, short event, void *arg) 441 { 442 struct imsgev *iev = arg; 443 struct privsep_proc *p = iev->proc; 444 struct privsep *ps = p->p_ps; 445 struct imsgbuf *ibuf; 446 struct imsg imsg; 447 ssize_t n; 448 int verbose; 449 const char *title; 450 451 title = ps->ps_title[privsep_process]; 452 ibuf = &iev->ibuf; 453 454 if (event & EV_READ) { 455 if ((n = imsg_read(ibuf)) == -1) 456 fatal(title); 457 if (n == 0) { 458 /* this pipe is dead, so remove the event handler */ 459 event_del(&iev->ev); 460 event_loopexit(NULL); 461 return; 462 } 463 } 464 465 if (event & EV_WRITE) { 466 if (msgbuf_write(&ibuf->w) <= 0 && errno != EAGAIN) 467 fatal(title); 468 } 469 470 for (;;) { 471 if ((n = imsg_get(ibuf, &imsg)) == -1) 472 fatal(title); 473 if (n == 0) 474 break; 475 476 #if DEBUG > 1 477 log_debug("%s: %s %d got imsg %d from %s %d", 478 __func__, title, ps->ps_instance + 1, 479 imsg.hdr.type, p->p_title, p->p_instance); 480 #endif 481 482 /* 483 * Check the message with the program callback 484 */ 485 if ((p->p_cb)(fd, p, &imsg) == 0) { 486 /* Message was handled by the callback, continue */ 487 imsg_free(&imsg); 488 continue; 489 } 490 491 /* 492 * Generic message handling 493 */ 494 switch (imsg.hdr.type) { 495 case IMSG_CTL_VERBOSE: 496 IMSG_SIZE_CHECK(&imsg, &verbose); 497 memcpy(&verbose, imsg.data, sizeof(verbose)); 498 log_verbose(verbose); 499 break; 500 default: 501 log_warnx("%s: %s %d got invalid imsg %d from %s %d", 502 __func__, title, ps->ps_instance + 1, 503 imsg.hdr.type, p->p_title, p->p_instance); 504 fatalx(title); 505 } 506 imsg_free(&imsg); 507 } 508 imsg_event_add(iev); 509 } 510 511 /* 512 * imsg helper functions 513 */ 514 515 void 516 imsg_event_add(struct imsgev *iev) 517 { 518 if (iev->handler == NULL) { 519 imsg_flush(&iev->ibuf); 520 return; 521 } 522 523 iev->events = EV_READ; 524 if (iev->ibuf.w.queued) 525 iev->events |= EV_WRITE; 526 527 event_del(&iev->ev); 528 event_set(&iev->ev, iev->ibuf.fd, iev->events, iev->handler, iev->data); 529 event_add(&iev->ev, NULL); 530 } 531 532 int 533 imsg_compose_event(struct imsgev *iev, u_int16_t type, u_int32_t peerid, 534 pid_t pid, int fd, void *data, u_int16_t datalen) 535 { 536 int ret; 537 538 if ((ret = imsg_compose(&iev->ibuf, type, peerid, 539 pid, fd, data, datalen)) == -1) 540 return (ret); 541 imsg_event_add(iev); 542 return (ret); 543 } 544 545 int 546 imsg_composev_event(struct imsgev *iev, u_int16_t type, u_int32_t peerid, 547 pid_t pid, int fd, const struct iovec *iov, int iovcnt) 548 { 549 int ret; 550 551 if ((ret = imsg_composev(&iev->ibuf, type, peerid, 552 pid, fd, iov, iovcnt)) == -1) 553 return (ret); 554 imsg_event_add(iev); 555 return (ret); 556 } 557 558 void 559 proc_range(struct privsep *ps, enum privsep_procid id, int *n, int *m) 560 { 561 if (*n == -1) { 562 /* Use a range of all target instances */ 563 *n = 0; 564 *m = ps->ps_instances[id]; 565 } else { 566 /* Use only a single slot of the specified peer process */ 567 *m = *n + 1; 568 } 569 } 570 571 int 572 proc_compose_imsg(struct privsep *ps, enum privsep_procid id, int n, 573 u_int16_t type, int fd, void *data, u_int16_t datalen) 574 { 575 int m; 576 577 proc_range(ps, id, &n, &m); 578 for (; n < m; n++) { 579 if (imsg_compose_event(&ps->ps_ievs[id][n], 580 type, -1, 0, fd, data, datalen) == -1) 581 return (-1); 582 } 583 584 return (0); 585 } 586 587 int 588 proc_composev_imsg(struct privsep *ps, enum privsep_procid id, int n, 589 u_int16_t type, int fd, const struct iovec *iov, int iovcnt) 590 { 591 int m; 592 593 proc_range(ps, id, &n, &m); 594 for (; n < m; n++) 595 if (imsg_composev_event(&ps->ps_ievs[id][n], 596 type, -1, 0, fd, iov, iovcnt) == -1) 597 return (-1); 598 599 return (0); 600 } 601 602 int 603 proc_forward_imsg(struct privsep *ps, struct imsg *imsg, 604 enum privsep_procid id, int n) 605 { 606 return (proc_compose_imsg(ps, id, n, imsg->hdr.type, 607 imsg->fd, imsg->data, IMSG_DATA_SIZE(imsg))); 608 } 609 610 struct imsgbuf * 611 proc_ibuf(struct privsep *ps, enum privsep_procid id, int n) 612 { 613 int m; 614 615 proc_range(ps, id, &n, &m); 616 return (&ps->ps_ievs[id][n].ibuf); 617 } 618 619 struct imsgev * 620 proc_iev(struct privsep *ps, enum privsep_procid id, int n) 621 { 622 int m; 623 624 proc_range(ps, id, &n, &m); 625 return (&ps->ps_ievs[id][n]); 626 } 627