1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2012 The FreeBSD Foundation 5 * 6 * This software was developed by Edward Tomasz Napierala under sponsorship 7 * from the FreeBSD Foundation. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include <sys/types.h> 36 #include <sys/time.h> 37 #include <sys/ioctl.h> 38 #include <sys/param.h> 39 #include <sys/linker.h> 40 #include <sys/socket.h> 41 #include <sys/capsicum.h> 42 #include <sys/wait.h> 43 #include <netinet/in.h> 44 #include <assert.h> 45 #include <capsicum_helpers.h> 46 #include <errno.h> 47 #include <fcntl.h> 48 #include <libutil.h> 49 #include <netdb.h> 50 #include <signal.h> 51 #include <stdbool.h> 52 #include <stdint.h> 53 #include <stdio.h> 54 #include <stdlib.h> 55 #include <string.h> 56 #include <unistd.h> 57 58 #include "iscsid.h" 59 60 static volatile bool sigalrm_received = false; 61 62 static int nchildren = 0; 63 64 static void 65 usage(void) 66 { 67 68 fprintf(stderr, "usage: iscsid [-P pidfile][-d][-m maxproc][-t timeout]\n"); 69 exit(1); 70 } 71 72 char * 73 checked_strdup(const char *s) 74 { 75 char *c; 76 77 c = strdup(s); 78 if (c == NULL) 79 log_err(1, "strdup"); 80 return (c); 81 } 82 83 static void 84 resolve_addr(const struct connection *conn, const char *address, 85 struct addrinfo **ai, bool initiator_side) 86 { 87 struct addrinfo hints; 88 char *arg, *addr, *ch; 89 const char *port; 90 int error, colons = 0; 91 92 arg = checked_strdup(address); 93 94 if (arg[0] == '\0') { 95 fail(conn, "empty address"); 96 log_errx(1, "empty address"); 97 } 98 if (arg[0] == '[') { 99 /* 100 * IPv6 address in square brackets, perhaps with port. 101 */ 102 arg++; 103 addr = strsep(&arg, "]"); 104 if (arg == NULL) { 105 fail(conn, "malformed address"); 106 log_errx(1, "malformed address %s", address); 107 } 108 if (arg[0] == '\0') { 109 port = NULL; 110 } else if (arg[0] == ':') { 111 port = arg + 1; 112 } else { 113 fail(conn, "malformed address"); 114 log_errx(1, "malformed address %s", address); 115 } 116 } else { 117 /* 118 * Either IPv6 address without brackets - and without 119 * a port - or IPv4 address. Just count the colons. 120 */ 121 for (ch = arg; *ch != '\0'; ch++) { 122 if (*ch == ':') 123 colons++; 124 } 125 if (colons > 1) { 126 addr = arg; 127 port = NULL; 128 } else { 129 addr = strsep(&arg, ":"); 130 if (arg == NULL) 131 port = NULL; 132 else 133 port = arg; 134 } 135 } 136 137 if (port == NULL && !initiator_side) 138 port = "3260"; 139 140 memset(&hints, 0, sizeof(hints)); 141 hints.ai_family = PF_UNSPEC; 142 hints.ai_socktype = SOCK_STREAM; 143 hints.ai_flags = AI_ADDRCONFIG | AI_NUMERICSERV; 144 if (initiator_side) 145 hints.ai_flags |= AI_PASSIVE; 146 147 error = getaddrinfo(addr, port, &hints, ai); 148 if (error != 0) { 149 fail(conn, gai_strerror(error)); 150 log_errx(1, "getaddrinfo for %s failed: %s", 151 address, gai_strerror(error)); 152 } 153 154 free(addr); 155 } 156 157 static struct connection * 158 connection_new(int iscsi_fd, const struct iscsi_daemon_request *request) 159 { 160 struct connection *conn; 161 struct iscsi_session_limits *isl; 162 struct addrinfo *from_ai, *to_ai; 163 const char *from_addr, *to_addr; 164 #ifdef ICL_KERNEL_PROXY 165 struct iscsi_daemon_connect idc; 166 #endif 167 int error, sockbuf; 168 169 conn = calloc(1, sizeof(*conn)); 170 if (conn == NULL) 171 log_err(1, "calloc"); 172 173 /* 174 * Default values, from RFC 3720, section 12. 175 */ 176 conn->conn_protocol_level = 0; 177 conn->conn_header_digest = CONN_DIGEST_NONE; 178 conn->conn_data_digest = CONN_DIGEST_NONE; 179 conn->conn_initial_r2t = true; 180 conn->conn_immediate_data = true; 181 conn->conn_max_recv_data_segment_length = 8192; 182 conn->conn_max_send_data_segment_length = 8192; 183 conn->conn_max_burst_length = 262144; 184 conn->conn_first_burst_length = 65536; 185 conn->conn_iscsi_fd = iscsi_fd; 186 187 conn->conn_session_id = request->idr_session_id; 188 memcpy(&conn->conn_conf, &request->idr_conf, sizeof(conn->conn_conf)); 189 memcpy(&conn->conn_isid, &request->idr_isid, sizeof(conn->conn_isid)); 190 conn->conn_tsih = request->idr_tsih; 191 192 /* 193 * Read the driver limits and provide reasonable defaults for the ones 194 * the driver doesn't care about. If a max_snd_dsl is not explicitly 195 * provided by the driver then we'll make sure both conn->max_snd_dsl 196 * and isl->max_snd_dsl are set to the rcv_dsl. This preserves historic 197 * behavior. 198 */ 199 isl = &conn->conn_limits; 200 memcpy(isl, &request->idr_limits, sizeof(*isl)); 201 if (isl->isl_max_recv_data_segment_length == 0) 202 isl->isl_max_recv_data_segment_length = (1 << 24) - 1; 203 if (isl->isl_max_send_data_segment_length == 0) 204 isl->isl_max_send_data_segment_length = 205 isl->isl_max_recv_data_segment_length; 206 if (isl->isl_max_burst_length == 0) 207 isl->isl_max_burst_length = (1 << 24) - 1; 208 if (isl->isl_first_burst_length == 0) 209 isl->isl_first_burst_length = (1 << 24) - 1; 210 if (isl->isl_first_burst_length > isl->isl_max_burst_length) 211 isl->isl_first_burst_length = isl->isl_max_burst_length; 212 213 /* 214 * Limit default send length in case it won't be negotiated. 215 * We can't do it for other limits, since they may affect both 216 * sender and receiver operation, and we must obey defaults. 217 */ 218 if (conn->conn_max_send_data_segment_length > 219 isl->isl_max_send_data_segment_length) { 220 conn->conn_max_send_data_segment_length = 221 isl->isl_max_send_data_segment_length; 222 } 223 224 from_addr = conn->conn_conf.isc_initiator_addr; 225 to_addr = conn->conn_conf.isc_target_addr; 226 227 if (from_addr[0] != '\0') 228 resolve_addr(conn, from_addr, &from_ai, true); 229 else 230 from_ai = NULL; 231 232 resolve_addr(conn, to_addr, &to_ai, false); 233 234 #ifdef ICL_KERNEL_PROXY 235 if (conn->conn_conf.isc_iser) { 236 memset(&idc, 0, sizeof(idc)); 237 idc.idc_session_id = conn->conn_session_id; 238 if (conn->conn_conf.isc_iser) 239 idc.idc_iser = 1; 240 idc.idc_domain = to_ai->ai_family; 241 idc.idc_socktype = to_ai->ai_socktype; 242 idc.idc_protocol = to_ai->ai_protocol; 243 if (from_ai != NULL) { 244 idc.idc_from_addr = from_ai->ai_addr; 245 idc.idc_from_addrlen = from_ai->ai_addrlen; 246 } 247 idc.idc_to_addr = to_ai->ai_addr; 248 idc.idc_to_addrlen = to_ai->ai_addrlen; 249 250 log_debugx("connecting to %s using ICL kernel proxy", to_addr); 251 error = ioctl(iscsi_fd, ISCSIDCONNECT, &idc); 252 if (error != 0) { 253 fail(conn, strerror(errno)); 254 log_err(1, "failed to connect to %s " 255 "using ICL kernel proxy: ISCSIDCONNECT", to_addr); 256 } 257 258 if (from_ai != NULL) 259 freeaddrinfo(from_ai); 260 freeaddrinfo(to_ai); 261 262 return (conn); 263 } 264 #endif /* ICL_KERNEL_PROXY */ 265 266 if (conn->conn_conf.isc_iser) { 267 fail(conn, "iSER not supported"); 268 log_errx(1, "iscsid(8) compiled without ICL_KERNEL_PROXY " 269 "does not support iSER"); 270 } 271 272 conn->conn_socket = socket(to_ai->ai_family, to_ai->ai_socktype, 273 to_ai->ai_protocol); 274 if (conn->conn_socket < 0) { 275 fail(conn, strerror(errno)); 276 log_err(1, "failed to create socket for %s", from_addr); 277 } 278 sockbuf = SOCKBUF_SIZE; 279 if (setsockopt(conn->conn_socket, SOL_SOCKET, SO_RCVBUF, 280 &sockbuf, sizeof(sockbuf)) == -1) 281 log_warn("setsockopt(SO_RCVBUF) failed"); 282 sockbuf = SOCKBUF_SIZE; 283 if (setsockopt(conn->conn_socket, SOL_SOCKET, SO_SNDBUF, 284 &sockbuf, sizeof(sockbuf)) == -1) 285 log_warn("setsockopt(SO_SNDBUF) failed"); 286 if (conn->conn_conf.isc_dscp != -1) { 287 int tos = conn->conn_conf.isc_dscp << 2; 288 if (to_ai->ai_family == AF_INET) { 289 if (setsockopt(conn->conn_socket, 290 IPPROTO_IP, IP_TOS, 291 &tos, sizeof(tos)) == -1) 292 log_warn("setsockopt(IP_TOS) " 293 "failed for %s", 294 from_addr); 295 } else 296 if (to_ai->ai_family == AF_INET6) { 297 if (setsockopt(conn->conn_socket, 298 IPPROTO_IPV6, IPV6_TCLASS, 299 &tos, sizeof(tos)) == -1) 300 log_warn("setsockopt(IPV6_TCLASS) " 301 "failed for %s", 302 from_addr); 303 } 304 } 305 if (conn->conn_conf.isc_pcp != -1) { 306 int pcp = conn->conn_conf.isc_pcp; 307 if (to_ai->ai_family == AF_INET) { 308 if (setsockopt(conn->conn_socket, 309 IPPROTO_IP, IP_VLAN_PCP, 310 &pcp, sizeof(pcp)) == -1) 311 log_warn("setsockopt(IP_VLAN_PCP) " 312 "failed for %s", 313 from_addr); 314 } else 315 if (to_ai->ai_family == AF_INET6) { 316 if (setsockopt(conn->conn_socket, 317 IPPROTO_IPV6, IPV6_VLAN_PCP, 318 &pcp, sizeof(pcp)) == -1) 319 log_warn("setsockopt(IPV6_VLAN_PCP) " 320 "failed for %s", 321 from_addr); 322 } 323 } 324 if (from_ai != NULL) { 325 error = bind(conn->conn_socket, from_ai->ai_addr, 326 from_ai->ai_addrlen); 327 if (error != 0) { 328 fail(conn, strerror(errno)); 329 log_err(1, "failed to bind to %s", from_addr); 330 } 331 } 332 log_debugx("connecting to %s", to_addr); 333 error = connect(conn->conn_socket, to_ai->ai_addr, to_ai->ai_addrlen); 334 if (error != 0) { 335 fail(conn, strerror(errno)); 336 log_err(1, "failed to connect to %s", to_addr); 337 } 338 339 if (from_ai != NULL) 340 freeaddrinfo(from_ai); 341 freeaddrinfo(to_ai); 342 343 return (conn); 344 } 345 346 static void 347 handoff(struct connection *conn) 348 { 349 struct iscsi_daemon_handoff idh; 350 int error; 351 352 log_debugx("handing off connection to the kernel"); 353 354 memset(&idh, 0, sizeof(idh)); 355 idh.idh_session_id = conn->conn_session_id; 356 idh.idh_socket = conn->conn_socket; 357 strlcpy(idh.idh_target_alias, conn->conn_target_alias, 358 sizeof(idh.idh_target_alias)); 359 idh.idh_tsih = conn->conn_tsih; 360 idh.idh_statsn = conn->conn_statsn; 361 idh.idh_protocol_level = conn->conn_protocol_level; 362 idh.idh_header_digest = conn->conn_header_digest; 363 idh.idh_data_digest = conn->conn_data_digest; 364 idh.idh_initial_r2t = conn->conn_initial_r2t; 365 idh.idh_immediate_data = conn->conn_immediate_data; 366 idh.idh_max_recv_data_segment_length = 367 conn->conn_max_recv_data_segment_length; 368 idh.idh_max_send_data_segment_length = 369 conn->conn_max_send_data_segment_length; 370 idh.idh_max_burst_length = conn->conn_max_burst_length; 371 idh.idh_first_burst_length = conn->conn_first_burst_length; 372 373 error = ioctl(conn->conn_iscsi_fd, ISCSIDHANDOFF, &idh); 374 if (error != 0) 375 log_err(1, "ISCSIDHANDOFF"); 376 } 377 378 void 379 fail(const struct connection *conn, const char *reason) 380 { 381 struct iscsi_daemon_fail idf; 382 int error, saved_errno; 383 384 saved_errno = errno; 385 386 memset(&idf, 0, sizeof(idf)); 387 idf.idf_session_id = conn->conn_session_id; 388 strlcpy(idf.idf_reason, reason, sizeof(idf.idf_reason)); 389 390 error = ioctl(conn->conn_iscsi_fd, ISCSIDFAIL, &idf); 391 if (error != 0) 392 log_err(1, "ISCSIDFAIL"); 393 394 errno = saved_errno; 395 } 396 397 /* 398 * XXX: I CANT INTO LATIN 399 */ 400 static void 401 capsicate(struct connection *conn) 402 { 403 cap_rights_t rights; 404 #ifdef ICL_KERNEL_PROXY 405 const unsigned long cmds[] = { ISCSIDCONNECT, ISCSIDSEND, ISCSIDRECEIVE, 406 ISCSIDHANDOFF, ISCSIDFAIL, ISCSISADD, ISCSISREMOVE, ISCSISMODIFY }; 407 #else 408 const unsigned long cmds[] = { ISCSIDHANDOFF, ISCSIDFAIL, ISCSISADD, 409 ISCSISREMOVE, ISCSISMODIFY }; 410 #endif 411 412 cap_rights_init(&rights, CAP_IOCTL); 413 if (caph_rights_limit(conn->conn_iscsi_fd, &rights) < 0) 414 log_err(1, "cap_rights_limit"); 415 416 if (caph_ioctls_limit(conn->conn_iscsi_fd, cmds, nitems(cmds)) < 0) 417 log_err(1, "cap_ioctls_limit"); 418 419 if (caph_enter() != 0) 420 log_err(1, "cap_enter"); 421 422 if (cap_sandboxed()) 423 log_debugx("Capsicum capability mode enabled"); 424 else 425 log_warnx("Capsicum capability mode not supported"); 426 } 427 428 bool 429 timed_out(void) 430 { 431 432 return (sigalrm_received); 433 } 434 435 static void 436 sigalrm_handler(int dummy __unused) 437 { 438 /* 439 * It would be easiest to just log an error and exit. We can't 440 * do this, though, because log_errx() is not signal safe, since 441 * it calls syslog(3). Instead, set a flag checked by pdu_send() 442 * and pdu_receive(), to call log_errx() there. Should they fail 443 * to notice, we'll exit here one second later. 444 */ 445 if (sigalrm_received) { 446 /* 447 * Oh well. Just give up and quit. 448 */ 449 _exit(2); 450 } 451 452 sigalrm_received = true; 453 } 454 455 static void 456 set_timeout(int timeout) 457 { 458 struct sigaction sa; 459 struct itimerval itv; 460 int error; 461 462 if (timeout <= 0) { 463 log_debugx("session timeout disabled"); 464 return; 465 } 466 467 bzero(&sa, sizeof(sa)); 468 sa.sa_handler = sigalrm_handler; 469 sigfillset(&sa.sa_mask); 470 error = sigaction(SIGALRM, &sa, NULL); 471 if (error != 0) 472 log_err(1, "sigaction"); 473 474 /* 475 * First SIGALRM will arive after conf_timeout seconds. 476 * If we do nothing, another one will arrive a second later. 477 */ 478 bzero(&itv, sizeof(itv)); 479 itv.it_interval.tv_sec = 1; 480 itv.it_value.tv_sec = timeout; 481 482 log_debugx("setting session timeout to %d seconds", 483 timeout); 484 error = setitimer(ITIMER_REAL, &itv, NULL); 485 if (error != 0) 486 log_err(1, "setitimer"); 487 } 488 489 static void 490 sigchld_handler(int dummy __unused) 491 { 492 493 /* 494 * The only purpose of this handler is to make SIGCHLD 495 * interrupt the ISCSIDWAIT ioctl(2), so we can call 496 * wait_for_children(). 497 */ 498 } 499 500 static void 501 register_sigchld(void) 502 { 503 struct sigaction sa; 504 int error; 505 506 bzero(&sa, sizeof(sa)); 507 sa.sa_handler = sigchld_handler; 508 sigfillset(&sa.sa_mask); 509 error = sigaction(SIGCHLD, &sa, NULL); 510 if (error != 0) 511 log_err(1, "sigaction"); 512 513 } 514 515 static void 516 handle_request(int iscsi_fd, const struct iscsi_daemon_request *request, int timeout) 517 { 518 struct connection *conn; 519 520 log_set_peer_addr(request->idr_conf.isc_target_addr); 521 if (request->idr_conf.isc_target[0] != '\0') { 522 log_set_peer_name(request->idr_conf.isc_target); 523 setproctitle("%s (%s)", request->idr_conf.isc_target_addr, request->idr_conf.isc_target); 524 } else { 525 setproctitle("%s", request->idr_conf.isc_target_addr); 526 } 527 528 conn = connection_new(iscsi_fd, request); 529 set_timeout(timeout); 530 capsicate(conn); 531 login(conn); 532 if (conn->conn_conf.isc_discovery != 0) 533 discovery(conn); 534 else 535 handoff(conn); 536 537 log_debugx("nothing more to do; exiting"); 538 exit (0); 539 } 540 541 static int 542 wait_for_children(bool block) 543 { 544 pid_t pid; 545 int status; 546 int num = 0; 547 548 for (;;) { 549 /* 550 * If "block" is true, wait for at least one process. 551 */ 552 if (block && num == 0) 553 pid = wait4(-1, &status, 0, NULL); 554 else 555 pid = wait4(-1, &status, WNOHANG, NULL); 556 if (pid <= 0) 557 break; 558 if (WIFSIGNALED(status)) { 559 log_warnx("child process %d terminated with signal %d", 560 pid, WTERMSIG(status)); 561 } else if (WEXITSTATUS(status) != 0) { 562 log_warnx("child process %d terminated with exit status %d", 563 pid, WEXITSTATUS(status)); 564 } else { 565 log_debugx("child process %d terminated gracefully", pid); 566 } 567 num++; 568 } 569 570 return (num); 571 } 572 573 int 574 main(int argc, char **argv) 575 { 576 int ch, debug = 0, error, iscsi_fd, maxproc = 30, retval, saved_errno, 577 timeout = 60; 578 bool dont_daemonize = false; 579 struct pidfh *pidfh; 580 pid_t pid, otherpid; 581 const char *pidfile_path = DEFAULT_PIDFILE; 582 struct iscsi_daemon_request request; 583 584 while ((ch = getopt(argc, argv, "P:dl:m:t:")) != -1) { 585 switch (ch) { 586 case 'P': 587 pidfile_path = optarg; 588 break; 589 case 'd': 590 dont_daemonize = true; 591 debug++; 592 break; 593 case 'l': 594 debug = atoi(optarg); 595 break; 596 case 'm': 597 maxproc = atoi(optarg); 598 break; 599 case 't': 600 timeout = atoi(optarg); 601 break; 602 case '?': 603 default: 604 usage(); 605 } 606 } 607 argc -= optind; 608 if (argc != 0) 609 usage(); 610 611 log_init(debug); 612 613 pidfh = pidfile_open(pidfile_path, 0600, &otherpid); 614 if (pidfh == NULL) { 615 if (errno == EEXIST) 616 log_errx(1, "daemon already running, pid: %jd.", 617 (intmax_t)otherpid); 618 log_err(1, "cannot open or create pidfile \"%s\"", 619 pidfile_path); 620 } 621 622 iscsi_fd = open(ISCSI_PATH, O_RDWR); 623 if (iscsi_fd < 0 && errno == ENOENT) { 624 saved_errno = errno; 625 retval = kldload("iscsi"); 626 if (retval != -1) 627 iscsi_fd = open(ISCSI_PATH, O_RDWR); 628 else 629 errno = saved_errno; 630 } 631 if (iscsi_fd < 0) 632 log_err(1, "failed to open %s", ISCSI_PATH); 633 634 if (dont_daemonize == false) { 635 if (daemon(0, 0) == -1) { 636 log_warn("cannot daemonize"); 637 pidfile_remove(pidfh); 638 exit(1); 639 } 640 } 641 642 pidfile_write(pidfh); 643 644 register_sigchld(); 645 646 for (;;) { 647 log_debugx("waiting for request from the kernel"); 648 649 memset(&request, 0, sizeof(request)); 650 error = ioctl(iscsi_fd, ISCSIDWAIT, &request); 651 if (error != 0) { 652 if (errno == EINTR) { 653 nchildren -= wait_for_children(false); 654 assert(nchildren >= 0); 655 continue; 656 } 657 658 log_err(1, "ISCSIDWAIT"); 659 } 660 661 if (dont_daemonize) { 662 log_debugx("not forking due to -d flag; " 663 "will exit after servicing a single request"); 664 } else { 665 nchildren -= wait_for_children(false); 666 assert(nchildren >= 0); 667 668 while (maxproc > 0 && nchildren >= maxproc) { 669 log_debugx("maxproc limit of %d child processes hit; " 670 "waiting for child process to exit", maxproc); 671 nchildren -= wait_for_children(true); 672 assert(nchildren >= 0); 673 } 674 log_debugx("incoming connection; forking child process #%d", 675 nchildren); 676 nchildren++; 677 678 pid = fork(); 679 if (pid < 0) 680 log_err(1, "fork"); 681 if (pid > 0) 682 continue; 683 } 684 685 pidfile_close(pidfh); 686 handle_request(iscsi_fd, &request, timeout); 687 } 688 689 return (0); 690 } 691