1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2012 The FreeBSD Foundation 5 * All rights reserved. 6 * 7 * This software was developed by Edward Tomasz Napierala under sponsorship 8 * from the FreeBSD Foundation. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 */ 32 33 #include <sys/cdefs.h> 34 __FBSDID("$FreeBSD$"); 35 36 #include <sys/types.h> 37 #include <sys/time.h> 38 #include <sys/ioctl.h> 39 #include <sys/param.h> 40 #include <sys/linker.h> 41 #include <sys/socket.h> 42 #include <sys/capsicum.h> 43 #include <sys/wait.h> 44 #include <assert.h> 45 #include <errno.h> 46 #include <fcntl.h> 47 #include <libutil.h> 48 #include <netdb.h> 49 #include <signal.h> 50 #include <stdbool.h> 51 #include <stdint.h> 52 #include <stdio.h> 53 #include <stdlib.h> 54 #include <string.h> 55 #include <unistd.h> 56 57 #include "iscsid.h" 58 59 static volatile bool sigalrm_received = false; 60 61 static int nchildren = 0; 62 63 static void 64 usage(void) 65 { 66 67 fprintf(stderr, "usage: iscsid [-P pidfile][-d][-m maxproc][-t timeout]\n"); 68 exit(1); 69 } 70 71 char * 72 checked_strdup(const char *s) 73 { 74 char *c; 75 76 c = strdup(s); 77 if (c == NULL) 78 log_err(1, "strdup"); 79 return (c); 80 } 81 82 static void 83 resolve_addr(const struct connection *conn, const char *address, 84 struct addrinfo **ai, bool initiator_side) 85 { 86 struct addrinfo hints; 87 char *arg, *addr, *ch; 88 const char *port; 89 int error, colons = 0; 90 91 arg = checked_strdup(address); 92 93 if (arg[0] == '\0') { 94 fail(conn, "empty address"); 95 log_errx(1, "empty address"); 96 } 97 if (arg[0] == '[') { 98 /* 99 * IPv6 address in square brackets, perhaps with port. 100 */ 101 arg++; 102 addr = strsep(&arg, "]"); 103 if (arg == NULL) { 104 fail(conn, "malformed address"); 105 log_errx(1, "malformed address %s", address); 106 } 107 if (arg[0] == '\0') { 108 port = NULL; 109 } else if (arg[0] == ':') { 110 port = arg + 1; 111 } else { 112 fail(conn, "malformed address"); 113 log_errx(1, "malformed address %s", address); 114 } 115 } else { 116 /* 117 * Either IPv6 address without brackets - and without 118 * a port - or IPv4 address. Just count the colons. 119 */ 120 for (ch = arg; *ch != '\0'; ch++) { 121 if (*ch == ':') 122 colons++; 123 } 124 if (colons > 1) { 125 addr = arg; 126 port = NULL; 127 } else { 128 addr = strsep(&arg, ":"); 129 if (arg == NULL) 130 port = NULL; 131 else 132 port = arg; 133 } 134 } 135 136 if (port == NULL && !initiator_side) 137 port = "3260"; 138 139 memset(&hints, 0, sizeof(hints)); 140 hints.ai_family = PF_UNSPEC; 141 hints.ai_socktype = SOCK_STREAM; 142 hints.ai_flags = AI_ADDRCONFIG | AI_NUMERICSERV; 143 if (initiator_side) 144 hints.ai_flags |= AI_PASSIVE; 145 146 error = getaddrinfo(addr, port, &hints, ai); 147 if (error != 0) { 148 fail(conn, gai_strerror(error)); 149 log_errx(1, "getaddrinfo for %s failed: %s", 150 address, gai_strerror(error)); 151 } 152 } 153 154 static struct connection * 155 connection_new(int iscsi_fd, const struct iscsi_daemon_request *request) 156 { 157 struct connection *conn; 158 struct iscsi_session_limits *isl; 159 struct addrinfo *from_ai, *to_ai; 160 const char *from_addr, *to_addr; 161 #ifdef ICL_KERNEL_PROXY 162 struct iscsi_daemon_connect idc; 163 #endif 164 int error, sockbuf; 165 166 conn = calloc(1, sizeof(*conn)); 167 if (conn == NULL) 168 log_err(1, "calloc"); 169 170 /* 171 * Default values, from RFC 3720, section 12. 172 */ 173 conn->conn_header_digest = CONN_DIGEST_NONE; 174 conn->conn_data_digest = CONN_DIGEST_NONE; 175 conn->conn_initial_r2t = true; 176 conn->conn_immediate_data = true; 177 conn->conn_max_recv_data_segment_length = 8192; 178 conn->conn_max_send_data_segment_length = 8192; 179 conn->conn_max_burst_length = 262144; 180 conn->conn_first_burst_length = 65536; 181 conn->conn_iscsi_fd = iscsi_fd; 182 183 conn->conn_session_id = request->idr_session_id; 184 memcpy(&conn->conn_conf, &request->idr_conf, sizeof(conn->conn_conf)); 185 memcpy(&conn->conn_isid, &request->idr_isid, sizeof(conn->conn_isid)); 186 conn->conn_tsih = request->idr_tsih; 187 188 /* 189 * Read the driver limits and provide reasonable defaults for the ones 190 * the driver doesn't care about. If a max_snd_dsl is not explicitly 191 * provided by the driver then we'll make sure both conn->max_snd_dsl 192 * and isl->max_snd_dsl are set to the rcv_dsl. This preserves historic 193 * behavior. 194 */ 195 isl = &conn->conn_limits; 196 memcpy(isl, &request->idr_limits, sizeof(*isl)); 197 if (isl->isl_max_recv_data_segment_length == 0) 198 isl->isl_max_recv_data_segment_length = (1 << 24) - 1; 199 if (isl->isl_max_send_data_segment_length == 0) 200 isl->isl_max_send_data_segment_length = 201 isl->isl_max_recv_data_segment_length; 202 if (isl->isl_max_burst_length == 0) 203 isl->isl_max_burst_length = (1 << 24) - 1; 204 if (isl->isl_first_burst_length == 0) 205 isl->isl_first_burst_length = (1 << 24) - 1; 206 if (isl->isl_first_burst_length > isl->isl_max_burst_length) 207 isl->isl_first_burst_length = isl->isl_max_burst_length; 208 209 /* 210 * Limit default send length in case it won't be negotiated. 211 * We can't do it for other limits, since they may affect both 212 * sender and receiver operation, and we must obey defaults. 213 */ 214 if (conn->conn_max_send_data_segment_length > 215 isl->isl_max_send_data_segment_length) { 216 conn->conn_max_send_data_segment_length = 217 isl->isl_max_send_data_segment_length; 218 } 219 220 from_addr = conn->conn_conf.isc_initiator_addr; 221 to_addr = conn->conn_conf.isc_target_addr; 222 223 if (from_addr[0] != '\0') 224 resolve_addr(conn, from_addr, &from_ai, true); 225 else 226 from_ai = NULL; 227 228 resolve_addr(conn, to_addr, &to_ai, false); 229 230 #ifdef ICL_KERNEL_PROXY 231 if (conn->conn_conf.isc_iser) { 232 memset(&idc, 0, sizeof(idc)); 233 idc.idc_session_id = conn->conn_session_id; 234 if (conn->conn_conf.isc_iser) 235 idc.idc_iser = 1; 236 idc.idc_domain = to_ai->ai_family; 237 idc.idc_socktype = to_ai->ai_socktype; 238 idc.idc_protocol = to_ai->ai_protocol; 239 if (from_ai != NULL) { 240 idc.idc_from_addr = from_ai->ai_addr; 241 idc.idc_from_addrlen = from_ai->ai_addrlen; 242 } 243 idc.idc_to_addr = to_ai->ai_addr; 244 idc.idc_to_addrlen = to_ai->ai_addrlen; 245 246 log_debugx("connecting to %s using ICL kernel proxy", to_addr); 247 error = ioctl(iscsi_fd, ISCSIDCONNECT, &idc); 248 if (error != 0) { 249 fail(conn, strerror(errno)); 250 log_err(1, "failed to connect to %s " 251 "using ICL kernel proxy: ISCSIDCONNECT", to_addr); 252 } 253 254 return (conn); 255 } 256 #endif /* ICL_KERNEL_PROXY */ 257 258 if (conn->conn_conf.isc_iser) { 259 fail(conn, "iSER not supported"); 260 log_errx(1, "iscsid(8) compiled without ICL_KERNEL_PROXY " 261 "does not support iSER"); 262 } 263 264 conn->conn_socket = socket(to_ai->ai_family, to_ai->ai_socktype, 265 to_ai->ai_protocol); 266 if (conn->conn_socket < 0) { 267 fail(conn, strerror(errno)); 268 log_err(1, "failed to create socket for %s", from_addr); 269 } 270 sockbuf = SOCKBUF_SIZE; 271 if (setsockopt(conn->conn_socket, SOL_SOCKET, SO_RCVBUF, 272 &sockbuf, sizeof(sockbuf)) == -1) 273 log_warn("setsockopt(SO_RCVBUF) failed"); 274 sockbuf = SOCKBUF_SIZE; 275 if (setsockopt(conn->conn_socket, SOL_SOCKET, SO_SNDBUF, 276 &sockbuf, sizeof(sockbuf)) == -1) 277 log_warn("setsockopt(SO_SNDBUF) failed"); 278 if (from_ai != NULL) { 279 error = bind(conn->conn_socket, from_ai->ai_addr, 280 from_ai->ai_addrlen); 281 if (error != 0) { 282 fail(conn, strerror(errno)); 283 log_err(1, "failed to bind to %s", from_addr); 284 } 285 } 286 log_debugx("connecting to %s", to_addr); 287 error = connect(conn->conn_socket, to_ai->ai_addr, to_ai->ai_addrlen); 288 if (error != 0) { 289 fail(conn, strerror(errno)); 290 log_err(1, "failed to connect to %s", to_addr); 291 } 292 293 return (conn); 294 } 295 296 static void 297 handoff(struct connection *conn) 298 { 299 struct iscsi_daemon_handoff idh; 300 int error; 301 302 log_debugx("handing off connection to the kernel"); 303 304 memset(&idh, 0, sizeof(idh)); 305 idh.idh_session_id = conn->conn_session_id; 306 idh.idh_socket = conn->conn_socket; 307 strlcpy(idh.idh_target_alias, conn->conn_target_alias, 308 sizeof(idh.idh_target_alias)); 309 idh.idh_tsih = conn->conn_tsih; 310 idh.idh_statsn = conn->conn_statsn; 311 idh.idh_header_digest = conn->conn_header_digest; 312 idh.idh_data_digest = conn->conn_data_digest; 313 idh.idh_initial_r2t = conn->conn_initial_r2t; 314 idh.idh_immediate_data = conn->conn_immediate_data; 315 idh.idh_max_recv_data_segment_length = 316 conn->conn_max_recv_data_segment_length; 317 idh.idh_max_send_data_segment_length = 318 conn->conn_max_send_data_segment_length; 319 idh.idh_max_burst_length = conn->conn_max_burst_length; 320 idh.idh_first_burst_length = conn->conn_first_burst_length; 321 322 error = ioctl(conn->conn_iscsi_fd, ISCSIDHANDOFF, &idh); 323 if (error != 0) 324 log_err(1, "ISCSIDHANDOFF"); 325 } 326 327 void 328 fail(const struct connection *conn, const char *reason) 329 { 330 struct iscsi_daemon_fail idf; 331 int error, saved_errno; 332 333 saved_errno = errno; 334 335 memset(&idf, 0, sizeof(idf)); 336 idf.idf_session_id = conn->conn_session_id; 337 strlcpy(idf.idf_reason, reason, sizeof(idf.idf_reason)); 338 339 error = ioctl(conn->conn_iscsi_fd, ISCSIDFAIL, &idf); 340 if (error != 0) 341 log_err(1, "ISCSIDFAIL"); 342 343 errno = saved_errno; 344 } 345 346 /* 347 * XXX: I CANT INTO LATIN 348 */ 349 static void 350 capsicate(struct connection *conn) 351 { 352 int error; 353 cap_rights_t rights; 354 #ifdef ICL_KERNEL_PROXY 355 const unsigned long cmds[] = { ISCSIDCONNECT, ISCSIDSEND, ISCSIDRECEIVE, 356 ISCSIDHANDOFF, ISCSIDFAIL, ISCSISADD, ISCSISREMOVE, ISCSISMODIFY }; 357 #else 358 const unsigned long cmds[] = { ISCSIDHANDOFF, ISCSIDFAIL, ISCSISADD, 359 ISCSISREMOVE, ISCSISMODIFY }; 360 #endif 361 362 cap_rights_init(&rights, CAP_IOCTL); 363 error = cap_rights_limit(conn->conn_iscsi_fd, &rights); 364 if (error != 0 && errno != ENOSYS) 365 log_err(1, "cap_rights_limit"); 366 367 error = cap_ioctls_limit(conn->conn_iscsi_fd, cmds, nitems(cmds)); 368 369 if (error != 0 && errno != ENOSYS) 370 log_err(1, "cap_ioctls_limit"); 371 372 error = cap_enter(); 373 if (error != 0 && errno != ENOSYS) 374 log_err(1, "cap_enter"); 375 376 if (cap_sandboxed()) 377 log_debugx("Capsicum capability mode enabled"); 378 else 379 log_warnx("Capsicum capability mode not supported"); 380 } 381 382 bool 383 timed_out(void) 384 { 385 386 return (sigalrm_received); 387 } 388 389 static void 390 sigalrm_handler(int dummy __unused) 391 { 392 /* 393 * It would be easiest to just log an error and exit. We can't 394 * do this, though, because log_errx() is not signal safe, since 395 * it calls syslog(3). Instead, set a flag checked by pdu_send() 396 * and pdu_receive(), to call log_errx() there. Should they fail 397 * to notice, we'll exit here one second later. 398 */ 399 if (sigalrm_received) { 400 /* 401 * Oh well. Just give up and quit. 402 */ 403 _exit(2); 404 } 405 406 sigalrm_received = true; 407 } 408 409 static void 410 set_timeout(int timeout) 411 { 412 struct sigaction sa; 413 struct itimerval itv; 414 int error; 415 416 if (timeout <= 0) { 417 log_debugx("session timeout disabled"); 418 return; 419 } 420 421 bzero(&sa, sizeof(sa)); 422 sa.sa_handler = sigalrm_handler; 423 sigfillset(&sa.sa_mask); 424 error = sigaction(SIGALRM, &sa, NULL); 425 if (error != 0) 426 log_err(1, "sigaction"); 427 428 /* 429 * First SIGALRM will arive after conf_timeout seconds. 430 * If we do nothing, another one will arrive a second later. 431 */ 432 bzero(&itv, sizeof(itv)); 433 itv.it_interval.tv_sec = 1; 434 itv.it_value.tv_sec = timeout; 435 436 log_debugx("setting session timeout to %d seconds", 437 timeout); 438 error = setitimer(ITIMER_REAL, &itv, NULL); 439 if (error != 0) 440 log_err(1, "setitimer"); 441 } 442 443 static void 444 sigchld_handler(int dummy __unused) 445 { 446 447 /* 448 * The only purpose of this handler is to make SIGCHLD 449 * interrupt the ISCSIDWAIT ioctl(2), so we can call 450 * wait_for_children(). 451 */ 452 } 453 454 static void 455 register_sigchld(void) 456 { 457 struct sigaction sa; 458 int error; 459 460 bzero(&sa, sizeof(sa)); 461 sa.sa_handler = sigchld_handler; 462 sigfillset(&sa.sa_mask); 463 error = sigaction(SIGCHLD, &sa, NULL); 464 if (error != 0) 465 log_err(1, "sigaction"); 466 467 } 468 469 static void 470 handle_request(int iscsi_fd, const struct iscsi_daemon_request *request, int timeout) 471 { 472 struct connection *conn; 473 474 log_set_peer_addr(request->idr_conf.isc_target_addr); 475 if (request->idr_conf.isc_target[0] != '\0') { 476 log_set_peer_name(request->idr_conf.isc_target); 477 setproctitle("%s (%s)", request->idr_conf.isc_target_addr, request->idr_conf.isc_target); 478 } else { 479 setproctitle("%s", request->idr_conf.isc_target_addr); 480 } 481 482 conn = connection_new(iscsi_fd, request); 483 set_timeout(timeout); 484 capsicate(conn); 485 login(conn); 486 if (conn->conn_conf.isc_discovery != 0) 487 discovery(conn); 488 else 489 handoff(conn); 490 491 log_debugx("nothing more to do; exiting"); 492 exit (0); 493 } 494 495 static int 496 wait_for_children(bool block) 497 { 498 pid_t pid; 499 int status; 500 int num = 0; 501 502 for (;;) { 503 /* 504 * If "block" is true, wait for at least one process. 505 */ 506 if (block && num == 0) 507 pid = wait4(-1, &status, 0, NULL); 508 else 509 pid = wait4(-1, &status, WNOHANG, NULL); 510 if (pid <= 0) 511 break; 512 if (WIFSIGNALED(status)) { 513 log_warnx("child process %d terminated with signal %d", 514 pid, WTERMSIG(status)); 515 } else if (WEXITSTATUS(status) != 0) { 516 log_warnx("child process %d terminated with exit status %d", 517 pid, WEXITSTATUS(status)); 518 } else { 519 log_debugx("child process %d terminated gracefully", pid); 520 } 521 num++; 522 } 523 524 return (num); 525 } 526 527 int 528 main(int argc, char **argv) 529 { 530 int ch, debug = 0, error, iscsi_fd, maxproc = 30, retval, saved_errno, 531 timeout = 60; 532 bool dont_daemonize = false; 533 struct pidfh *pidfh; 534 pid_t pid, otherpid; 535 const char *pidfile_path = DEFAULT_PIDFILE; 536 struct iscsi_daemon_request request; 537 538 while ((ch = getopt(argc, argv, "P:dl:m:t:")) != -1) { 539 switch (ch) { 540 case 'P': 541 pidfile_path = optarg; 542 break; 543 case 'd': 544 dont_daemonize = true; 545 debug++; 546 break; 547 case 'l': 548 debug = atoi(optarg); 549 break; 550 case 'm': 551 maxproc = atoi(optarg); 552 break; 553 case 't': 554 timeout = atoi(optarg); 555 break; 556 case '?': 557 default: 558 usage(); 559 } 560 } 561 argc -= optind; 562 if (argc != 0) 563 usage(); 564 565 log_init(debug); 566 567 pidfh = pidfile_open(pidfile_path, 0600, &otherpid); 568 if (pidfh == NULL) { 569 if (errno == EEXIST) 570 log_errx(1, "daemon already running, pid: %jd.", 571 (intmax_t)otherpid); 572 log_err(1, "cannot open or create pidfile \"%s\"", 573 pidfile_path); 574 } 575 576 iscsi_fd = open(ISCSI_PATH, O_RDWR); 577 if (iscsi_fd < 0 && errno == ENOENT) { 578 saved_errno = errno; 579 retval = kldload("iscsi"); 580 if (retval != -1) 581 iscsi_fd = open(ISCSI_PATH, O_RDWR); 582 else 583 errno = saved_errno; 584 } 585 if (iscsi_fd < 0) 586 log_err(1, "failed to open %s", ISCSI_PATH); 587 588 if (dont_daemonize == false) { 589 if (daemon(0, 0) == -1) { 590 log_warn("cannot daemonize"); 591 pidfile_remove(pidfh); 592 exit(1); 593 } 594 } 595 596 pidfile_write(pidfh); 597 598 register_sigchld(); 599 600 for (;;) { 601 log_debugx("waiting for request from the kernel"); 602 603 memset(&request, 0, sizeof(request)); 604 error = ioctl(iscsi_fd, ISCSIDWAIT, &request); 605 if (error != 0) { 606 if (errno == EINTR) { 607 nchildren -= wait_for_children(false); 608 assert(nchildren >= 0); 609 continue; 610 } 611 612 log_err(1, "ISCSIDWAIT"); 613 } 614 615 if (dont_daemonize) { 616 log_debugx("not forking due to -d flag; " 617 "will exit after servicing a single request"); 618 } else { 619 nchildren -= wait_for_children(false); 620 assert(nchildren >= 0); 621 622 while (maxproc > 0 && nchildren >= maxproc) { 623 log_debugx("maxproc limit of %d child processes hit; " 624 "waiting for child process to exit", maxproc); 625 nchildren -= wait_for_children(true); 626 assert(nchildren >= 0); 627 } 628 log_debugx("incoming connection; forking child process #%d", 629 nchildren); 630 nchildren++; 631 632 pid = fork(); 633 if (pid < 0) 634 log_err(1, "fork"); 635 if (pid > 0) 636 continue; 637 } 638 639 pidfile_close(pidfh); 640 handle_request(iscsi_fd, &request, timeout); 641 } 642 643 return (0); 644 } 645