1 /* $OpenBSD: proc.c,v 1.1 2014/07/12 23:34:54 reyk 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/types.h> 21 #include <sys/queue.h> 22 #include <sys/socket.h> 23 #include <sys/wait.h> 24 #include <sys/tree.h> 25 26 #include <net/if.h> 27 #include <netinet/in_systm.h> 28 #include <netinet/in.h> 29 #include <netinet/ip.h> 30 #include <arpa/inet.h> 31 32 #include <stdio.h> 33 #include <stdlib.h> 34 #include <unistd.h> 35 #include <string.h> 36 #include <errno.h> 37 #include <signal.h> 38 #include <pwd.h> 39 #include <event.h> 40 41 #include <openssl/ssl.h> 42 43 #include "httpd.h" 44 45 void proc_open(struct privsep *, struct privsep_proc *, 46 struct privsep_proc *, size_t); 47 void proc_close(struct privsep *); 48 int proc_ispeer(struct privsep_proc *, u_int, enum privsep_procid); 49 void proc_shutdown(struct privsep_proc *); 50 void proc_sig_handler(int, short, void *); 51 void proc_range(struct privsep *, enum privsep_procid, int *, int *); 52 53 int 54 proc_ispeer(struct privsep_proc *procs, u_int nproc, enum privsep_procid type) 55 { 56 u_int i; 57 58 for (i = 0; i < nproc; i++) 59 if (procs[i].p_id == type) 60 return (1); 61 return (0); 62 } 63 64 void 65 proc_init(struct privsep *ps, struct privsep_proc *procs, u_int nproc) 66 { 67 u_int i, j, src, dst; 68 struct privsep_pipes *pp; 69 70 /* 71 * Allocate pipes for all process instances (incl. parent) 72 * 73 * - ps->ps_pipes: N:M mapping 74 * N source processes connected to M destination processes: 75 * [src][instances][dst][instances], for example 76 * [PROC_RELAY][3][PROC_CA][3] 77 * 78 * - ps->ps_pp: per-process 1:M part of ps->ps_pipes 79 * Each process instance has a destination array of socketpair fds: 80 * [dst][instances], for example 81 * [PROC_PARENT][0] 82 */ 83 for (src = 0; src < PROC_MAX; src++) { 84 /* Allocate destination array for each process */ 85 if ((ps->ps_pipes[src] = calloc(ps->ps_ninstances, 86 sizeof(struct privsep_pipes))) == NULL) 87 fatal("proc_init: calloc"); 88 89 for (i = 0; i < ps->ps_ninstances; i++) { 90 pp = &ps->ps_pipes[src][i]; 91 92 for (dst = 0; dst < PROC_MAX; dst++) { 93 /* Allocate maximum fd integers */ 94 if ((pp->pp_pipes[dst] = 95 calloc(ps->ps_ninstances, 96 sizeof(int))) == NULL) 97 fatal("proc_init: calloc"); 98 99 /* Mark fd as unused */ 100 for (j = 0; j < ps->ps_ninstances; j++) 101 pp->pp_pipes[dst][j] = -1; 102 } 103 } 104 } 105 106 /* 107 * Setup and run the parent and its children 108 */ 109 privsep_process = PROC_PARENT; 110 ps->ps_instances[PROC_PARENT] = 1; 111 ps->ps_title[PROC_PARENT] = "parent"; 112 ps->ps_pid[PROC_PARENT] = getpid(); 113 ps->ps_pp = &ps->ps_pipes[privsep_process][0]; 114 115 for (i = 0; i < nproc; i++) { 116 /* Default to 1 process instance */ 117 if (ps->ps_instances[procs[i].p_id] < 1) 118 ps->ps_instances[procs[i].p_id] = 1; 119 ps->ps_title[procs[i].p_id] = procs[i].p_title; 120 } 121 122 proc_open(ps, NULL, procs, nproc); 123 124 /* Engage! */ 125 for (i = 0; i < nproc; i++) 126 ps->ps_pid[procs[i].p_id] = (*procs[i].p_init)(ps, &procs[i]); 127 } 128 129 void 130 proc_kill(struct privsep *ps) 131 { 132 pid_t pid; 133 u_int i; 134 135 if (privsep_process != PROC_PARENT) 136 return; 137 138 for (i = 0; i < PROC_MAX; i++) { 139 if (ps->ps_pid[i] == 0) 140 continue; 141 killpg(ps->ps_pid[i], SIGTERM); 142 } 143 144 do { 145 pid = waitpid(WAIT_ANY, NULL, 0); 146 } while (pid != -1 || (pid == -1 && errno == EINTR)); 147 148 proc_close(ps); 149 } 150 151 void 152 proc_open(struct privsep *ps, struct privsep_proc *p, 153 struct privsep_proc *procs, size_t nproc) 154 { 155 struct privsep_pipes *pa, *pb; 156 int fds[2]; 157 u_int i, j, src, proc; 158 159 if (p == NULL) 160 src = privsep_process; /* parent */ 161 else 162 src = p->p_id; 163 164 /* 165 * Open socket pairs for our peers 166 */ 167 for (proc = 0; proc < nproc; proc++) { 168 procs[proc].p_ps = ps; 169 procs[proc].p_env = ps->ps_env; 170 171 for (i = 0; i < ps->ps_instances[src]; i++) { 172 for (j = 0; j < ps->ps_instances[procs[proc].p_id]; 173 j++) { 174 pa = &ps->ps_pipes[src][i]; 175 pb = &ps->ps_pipes[procs[proc].p_id][j]; 176 177 /* Check if fds are already set by peer */ 178 if (pa->pp_pipes[procs[proc].p_id][j] != -1) 179 continue; 180 181 if (socketpair(AF_UNIX, SOCK_STREAM, 182 PF_UNSPEC, fds) == -1) 183 fatal("socketpair"); 184 185 socket_set_blockmode(fds[0], BM_NONBLOCK); 186 socket_set_blockmode(fds[1], BM_NONBLOCK); 187 188 pa->pp_pipes[procs[proc].p_id][j] = fds[0]; 189 pb->pp_pipes[src][i] = fds[1]; 190 } 191 } 192 } 193 } 194 195 void 196 proc_listen(struct privsep *ps, struct privsep_proc *procs, size_t nproc) 197 { 198 u_int i, dst, src, n, m; 199 struct privsep_pipes *pp; 200 201 /* 202 * Close unused pipes 203 */ 204 for (src = 0; src < PROC_MAX; src++) { 205 for (n = 0; n < ps->ps_instances[src]; n++) { 206 /* Ingore current process */ 207 if (src == (u_int)privsep_process && 208 n == ps->ps_instance) 209 continue; 210 211 pp = &ps->ps_pipes[src][n]; 212 213 for (dst = 0; dst < PROC_MAX; dst++) { 214 if (src == dst) 215 continue; 216 for (m = 0; m < ps->ps_instances[dst]; m++) { 217 if (pp->pp_pipes[dst][m] == -1) 218 continue; 219 220 /* Close and invalidate fd */ 221 close(pp->pp_pipes[dst][m]); 222 pp->pp_pipes[dst][m] = -1; 223 } 224 } 225 } 226 } 227 228 src = privsep_process; 229 ps->ps_pp = pp = &ps->ps_pipes[src][ps->ps_instance]; 230 231 /* 232 * Listen on appropriate pipes 233 */ 234 for (i = 0; i < nproc; i++) { 235 dst = procs[i].p_id; 236 237 if (src == dst) 238 fatal("proc_listen: cannot peer with oneself"); 239 240 if ((ps->ps_ievs[dst] = calloc(ps->ps_instances[dst], 241 sizeof(struct imsgev))) == NULL) 242 fatal("proc_open"); 243 244 for (n = 0; n < ps->ps_instances[dst]; n++) { 245 if (pp->pp_pipes[dst][n] == -1) 246 continue; 247 248 imsg_init(&(ps->ps_ievs[dst][n].ibuf), 249 pp->pp_pipes[dst][n]); 250 ps->ps_ievs[dst][n].handler = proc_dispatch; 251 ps->ps_ievs[dst][n].events = EV_READ; 252 ps->ps_ievs[dst][n].proc = &procs[i]; 253 ps->ps_ievs[dst][n].data = &ps->ps_ievs[dst][n]; 254 procs[i].p_instance = n; 255 256 event_set(&(ps->ps_ievs[dst][n].ev), 257 ps->ps_ievs[dst][n].ibuf.fd, 258 ps->ps_ievs[dst][n].events, 259 ps->ps_ievs[dst][n].handler, 260 ps->ps_ievs[dst][n].data); 261 event_add(&(ps->ps_ievs[dst][n].ev), NULL); 262 } 263 } 264 } 265 266 void 267 proc_close(struct privsep *ps) 268 { 269 u_int dst, n; 270 struct privsep_pipes *pp; 271 272 if (ps == NULL) 273 return; 274 275 pp = ps->ps_pp; 276 277 for (dst = 0; dst < PROC_MAX; dst++) { 278 if (ps->ps_ievs[dst] == NULL) 279 continue; 280 281 for (n = 0; n < ps->ps_instances[dst]; n++) { 282 if (pp->pp_pipes[dst][n] == -1) 283 continue; 284 285 /* Cancel the fd, close and invalidate the fd */ 286 event_del(&(ps->ps_ievs[dst][n].ev)); 287 imsg_clear(&(ps->ps_ievs[dst][n].ibuf)); 288 close(pp->pp_pipes[dst][n]); 289 pp->pp_pipes[dst][n] = -1; 290 } 291 free(ps->ps_ievs[dst]); 292 } 293 } 294 295 void 296 proc_shutdown(struct privsep_proc *p) 297 { 298 struct privsep *ps = p->p_ps; 299 300 if (p->p_id == PROC_CONTROL && ps) 301 control_cleanup(&ps->ps_csock); 302 303 if (p->p_shutdown != NULL) 304 (*p->p_shutdown)(); 305 306 proc_close(ps); 307 308 log_info("%s exiting, pid %d", p->p_title, getpid()); 309 310 _exit(0); 311 } 312 313 void 314 proc_sig_handler(int sig, short event, void *arg) 315 { 316 struct privsep_proc *p = arg; 317 318 switch (sig) { 319 case SIGINT: 320 case SIGTERM: 321 proc_shutdown(p); 322 break; 323 case SIGCHLD: 324 case SIGHUP: 325 case SIGPIPE: 326 /* ignore */ 327 break; 328 default: 329 fatalx("proc_sig_handler: unexpected signal"); 330 /* NOTREACHED */ 331 } 332 } 333 334 pid_t 335 proc_run(struct privsep *ps, struct privsep_proc *p, 336 struct privsep_proc *procs, u_int nproc, 337 void (*init)(struct privsep *, struct privsep_proc *, void *), void *arg) 338 { 339 pid_t pid; 340 struct passwd *pw; 341 const char *root; 342 struct control_sock *rcs; 343 u_int n; 344 345 if (ps->ps_noaction) 346 return (0); 347 348 proc_open(ps, p, procs, nproc); 349 350 /* Fork child handlers */ 351 switch (pid = fork()) { 352 case -1: 353 fatal("proc_run: cannot fork"); 354 case 0: 355 /* Set the process group of the current process */ 356 setpgrp(0, getpid()); 357 break; 358 default: 359 return (pid); 360 } 361 362 pw = ps->ps_pw; 363 364 if (p->p_id == PROC_CONTROL && ps->ps_instance == 0) { 365 if (control_init(ps, &ps->ps_csock) == -1) 366 fatalx(p->p_title); 367 TAILQ_FOREACH(rcs, &ps->ps_rcsocks, cs_entry) 368 if (control_init(ps, rcs) == -1) 369 fatalx(p->p_title); 370 } 371 372 /* Change root directory */ 373 if (p->p_chroot != NULL) 374 root = p->p_chroot; 375 else 376 root = pw->pw_dir; 377 378 if (chroot(root) == -1) 379 fatal("proc_run: chroot"); 380 if (chdir("/") == -1) 381 fatal("proc_run: chdir(\"/\")"); 382 383 privsep_process = p->p_id; 384 385 setproctitle("%s", p->p_title); 386 387 if (setgroups(1, &pw->pw_gid) || 388 setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) || 389 setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid)) 390 fatal("proc_run: cannot drop privileges"); 391 392 /* Fork child handlers */ 393 for (n = 1; n < ps->ps_instances[p->p_id]; n++) { 394 if (fork() == 0) { 395 ps->ps_instance = p->p_instance = n; 396 break; 397 } 398 } 399 400 #ifdef DEBUG 401 log_debug("%s: %s %d/%d, pid %d", __func__, p->p_title, 402 ps->ps_instance + 1, ps->ps_instances[p->p_id], getpid()); 403 #endif 404 405 event_init(); 406 407 signal_set(&ps->ps_evsigint, SIGINT, proc_sig_handler, p); 408 signal_set(&ps->ps_evsigterm, SIGTERM, proc_sig_handler, p); 409 signal_set(&ps->ps_evsigchld, SIGCHLD, proc_sig_handler, p); 410 signal_set(&ps->ps_evsighup, SIGHUP, proc_sig_handler, p); 411 signal_set(&ps->ps_evsigpipe, SIGPIPE, proc_sig_handler, p); 412 413 signal_add(&ps->ps_evsigint, NULL); 414 signal_add(&ps->ps_evsigterm, NULL); 415 signal_add(&ps->ps_evsigchld, NULL); 416 signal_add(&ps->ps_evsighup, NULL); 417 signal_add(&ps->ps_evsigpipe, NULL); 418 419 proc_listen(ps, procs, nproc); 420 421 if (p->p_id == PROC_CONTROL && ps->ps_instance == 0) { 422 TAILQ_INIT(&ctl_conns); 423 if (control_listen(&ps->ps_csock) == -1) 424 fatalx(p->p_title); 425 TAILQ_FOREACH(rcs, &ps->ps_rcsocks, cs_entry) 426 if (control_listen(rcs) == -1) 427 fatalx(p->p_title); 428 } 429 430 if (init != NULL) 431 init(ps, p, arg); 432 433 event_dispatch(); 434 435 proc_shutdown(p); 436 437 return (0); 438 } 439 440 void 441 proc_dispatch(int fd, short event, void *arg) 442 { 443 struct imsgev *iev = arg; 444 struct privsep_proc *p = iev->proc; 445 struct privsep *ps = p->p_ps; 446 struct imsgbuf *ibuf; 447 struct imsg imsg; 448 ssize_t n; 449 int verbose; 450 const char *title; 451 452 title = ps->ps_title[privsep_process]; 453 ibuf = &iev->ibuf; 454 455 if (event & EV_READ) { 456 if ((n = imsg_read(ibuf)) == -1) 457 fatal(title); 458 if (n == 0) { 459 /* this pipe is dead, so remove the event handler */ 460 event_del(&iev->ev); 461 event_loopexit(NULL); 462 return; 463 } 464 } 465 466 if (event & EV_WRITE) { 467 if (msgbuf_write(&ibuf->w) <= 0 && errno != EAGAIN) 468 fatal(title); 469 } 470 471 for (;;) { 472 if ((n = imsg_get(ibuf, &imsg)) == -1) 473 fatal(title); 474 if (n == 0) 475 break; 476 477 #if DEBUG > 1 478 log_debug("%s: %s %d got imsg %d from %s %d", 479 __func__, title, ps->ps_instance + 1, 480 imsg.hdr.type, p->p_title, p->p_instance); 481 #endif 482 483 /* 484 * Check the message with the program callback 485 */ 486 if ((p->p_cb)(fd, p, &imsg) == 0) { 487 /* Message was handled by the callback, continue */ 488 imsg_free(&imsg); 489 continue; 490 } 491 492 /* 493 * Generic message handling 494 */ 495 switch (imsg.hdr.type) { 496 case IMSG_CTL_VERBOSE: 497 IMSG_SIZE_CHECK(&imsg, &verbose); 498 memcpy(&verbose, imsg.data, sizeof(verbose)); 499 log_verbose(verbose); 500 break; 501 default: 502 log_warnx("%s: %s %d got invalid imsg %d from %s %d", 503 __func__, title, ps->ps_instance + 1, 504 imsg.hdr.type, p->p_title, p->p_instance); 505 fatalx(title); 506 } 507 imsg_free(&imsg); 508 } 509 imsg_event_add(iev); 510 } 511 512 /* 513 * imsg helper functions 514 */ 515 516 void 517 imsg_event_add(struct imsgev *iev) 518 { 519 if (iev->handler == NULL) { 520 imsg_flush(&iev->ibuf); 521 return; 522 } 523 524 iev->events = EV_READ; 525 if (iev->ibuf.w.queued) 526 iev->events |= EV_WRITE; 527 528 event_del(&iev->ev); 529 event_set(&iev->ev, iev->ibuf.fd, iev->events, iev->handler, iev->data); 530 event_add(&iev->ev, NULL); 531 } 532 533 int 534 imsg_compose_event(struct imsgev *iev, u_int16_t type, u_int32_t peerid, 535 pid_t pid, int fd, void *data, u_int16_t datalen) 536 { 537 int ret; 538 539 if ((ret = imsg_compose(&iev->ibuf, type, peerid, 540 pid, fd, data, datalen)) == -1) 541 return (ret); 542 imsg_event_add(iev); 543 return (ret); 544 } 545 546 int 547 imsg_composev_event(struct imsgev *iev, u_int16_t type, u_int32_t peerid, 548 pid_t pid, int fd, const struct iovec *iov, int iovcnt) 549 { 550 int ret; 551 552 if ((ret = imsg_composev(&iev->ibuf, type, peerid, 553 pid, fd, iov, iovcnt)) == -1) 554 return (ret); 555 imsg_event_add(iev); 556 return (ret); 557 } 558 559 void 560 proc_range(struct privsep *ps, enum privsep_procid id, int *n, int *m) 561 { 562 if (*n == -1) { 563 /* Use a range of all target instances */ 564 *n = 0; 565 *m = ps->ps_instances[id]; 566 } else { 567 /* Use only a single slot of the specified peer process */ 568 *m = *n + 1; 569 } 570 } 571 572 int 573 proc_compose_imsg(struct privsep *ps, enum privsep_procid id, int n, 574 u_int16_t type, int fd, void *data, u_int16_t datalen) 575 { 576 int m; 577 578 proc_range(ps, id, &n, &m); 579 for (; n < m; n++) { 580 if (imsg_compose_event(&ps->ps_ievs[id][n], 581 type, -1, 0, fd, data, datalen) == -1) 582 return (-1); 583 } 584 585 return (0); 586 } 587 588 int 589 proc_composev_imsg(struct privsep *ps, enum privsep_procid id, int n, 590 u_int16_t type, int fd, const struct iovec *iov, int iovcnt) 591 { 592 int m; 593 594 proc_range(ps, id, &n, &m); 595 for (; n < m; n++) 596 if (imsg_composev_event(&ps->ps_ievs[id][n], 597 type, -1, 0, fd, iov, iovcnt) == -1) 598 return (-1); 599 600 return (0); 601 } 602 603 int 604 proc_forward_imsg(struct privsep *ps, struct imsg *imsg, 605 enum privsep_procid id, int n) 606 { 607 return (proc_compose_imsg(ps, id, n, imsg->hdr.type, 608 imsg->fd, imsg->data, IMSG_DATA_SIZE(imsg))); 609 } 610 611 struct imsgbuf * 612 proc_ibuf(struct privsep *ps, enum privsep_procid id, int n) 613 { 614 int m; 615 616 proc_range(ps, id, &n, &m); 617 return (&ps->ps_ievs[id][n].ibuf); 618 } 619 620 struct imsgev * 621 proc_iev(struct privsep *ps, enum privsep_procid id, int n) 622 { 623 int m; 624 625 proc_range(ps, id, &n, &m); 626 return (&ps->ps_ievs[id][n]); 627 } 628