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 } 154 155 static struct connection * 156 connection_new(int iscsi_fd, const struct iscsi_daemon_request *request) 157 { 158 struct connection *conn; 159 struct iscsi_session_limits *isl; 160 struct addrinfo *from_ai, *to_ai; 161 const char *from_addr, *to_addr; 162 #ifdef ICL_KERNEL_PROXY 163 struct iscsi_daemon_connect idc; 164 #endif 165 int error, sockbuf; 166 167 conn = calloc(1, sizeof(*conn)); 168 if (conn == NULL) 169 log_err(1, "calloc"); 170 171 /* 172 * Default values, from RFC 3720, section 12. 173 */ 174 conn->conn_protocol_level = 0; 175 conn->conn_header_digest = CONN_DIGEST_NONE; 176 conn->conn_data_digest = CONN_DIGEST_NONE; 177 conn->conn_initial_r2t = true; 178 conn->conn_immediate_data = true; 179 conn->conn_max_recv_data_segment_length = 8192; 180 conn->conn_max_send_data_segment_length = 8192; 181 conn->conn_max_burst_length = 262144; 182 conn->conn_first_burst_length = 65536; 183 conn->conn_iscsi_fd = iscsi_fd; 184 185 conn->conn_session_id = request->idr_session_id; 186 memcpy(&conn->conn_conf, &request->idr_conf, sizeof(conn->conn_conf)); 187 memcpy(&conn->conn_isid, &request->idr_isid, sizeof(conn->conn_isid)); 188 conn->conn_tsih = request->idr_tsih; 189 190 /* 191 * Read the driver limits and provide reasonable defaults for the ones 192 * the driver doesn't care about. If a max_snd_dsl is not explicitly 193 * provided by the driver then we'll make sure both conn->max_snd_dsl 194 * and isl->max_snd_dsl are set to the rcv_dsl. This preserves historic 195 * behavior. 196 */ 197 isl = &conn->conn_limits; 198 memcpy(isl, &request->idr_limits, sizeof(*isl)); 199 if (isl->isl_max_recv_data_segment_length == 0) 200 isl->isl_max_recv_data_segment_length = (1 << 24) - 1; 201 if (isl->isl_max_send_data_segment_length == 0) 202 isl->isl_max_send_data_segment_length = 203 isl->isl_max_recv_data_segment_length; 204 if (isl->isl_max_burst_length == 0) 205 isl->isl_max_burst_length = (1 << 24) - 1; 206 if (isl->isl_first_burst_length == 0) 207 isl->isl_first_burst_length = (1 << 24) - 1; 208 if (isl->isl_first_burst_length > isl->isl_max_burst_length) 209 isl->isl_first_burst_length = isl->isl_max_burst_length; 210 211 /* 212 * Limit default send length in case it won't be negotiated. 213 * We can't do it for other limits, since they may affect both 214 * sender and receiver operation, and we must obey defaults. 215 */ 216 if (conn->conn_max_send_data_segment_length > 217 isl->isl_max_send_data_segment_length) { 218 conn->conn_max_send_data_segment_length = 219 isl->isl_max_send_data_segment_length; 220 } 221 222 from_addr = conn->conn_conf.isc_initiator_addr; 223 to_addr = conn->conn_conf.isc_target_addr; 224 225 if (from_addr[0] != '\0') 226 resolve_addr(conn, from_addr, &from_ai, true); 227 else 228 from_ai = NULL; 229 230 resolve_addr(conn, to_addr, &to_ai, false); 231 232 #ifdef ICL_KERNEL_PROXY 233 if (conn->conn_conf.isc_iser) { 234 memset(&idc, 0, sizeof(idc)); 235 idc.idc_session_id = conn->conn_session_id; 236 if (conn->conn_conf.isc_iser) 237 idc.idc_iser = 1; 238 idc.idc_domain = to_ai->ai_family; 239 idc.idc_socktype = to_ai->ai_socktype; 240 idc.idc_protocol = to_ai->ai_protocol; 241 if (from_ai != NULL) { 242 idc.idc_from_addr = from_ai->ai_addr; 243 idc.idc_from_addrlen = from_ai->ai_addrlen; 244 } 245 idc.idc_to_addr = to_ai->ai_addr; 246 idc.idc_to_addrlen = to_ai->ai_addrlen; 247 248 log_debugx("connecting to %s using ICL kernel proxy", to_addr); 249 error = ioctl(iscsi_fd, ISCSIDCONNECT, &idc); 250 if (error != 0) { 251 fail(conn, strerror(errno)); 252 log_err(1, "failed to connect to %s " 253 "using ICL kernel proxy: ISCSIDCONNECT", to_addr); 254 } 255 256 return (conn); 257 } 258 #endif /* ICL_KERNEL_PROXY */ 259 260 if (conn->conn_conf.isc_iser) { 261 fail(conn, "iSER not supported"); 262 log_errx(1, "iscsid(8) compiled without ICL_KERNEL_PROXY " 263 "does not support iSER"); 264 } 265 266 conn->conn_socket = socket(to_ai->ai_family, to_ai->ai_socktype, 267 to_ai->ai_protocol); 268 if (conn->conn_socket < 0) { 269 fail(conn, strerror(errno)); 270 log_err(1, "failed to create socket for %s", from_addr); 271 } 272 sockbuf = SOCKBUF_SIZE; 273 if (setsockopt(conn->conn_socket, SOL_SOCKET, SO_RCVBUF, 274 &sockbuf, sizeof(sockbuf)) == -1) 275 log_warn("setsockopt(SO_RCVBUF) failed"); 276 sockbuf = SOCKBUF_SIZE; 277 if (setsockopt(conn->conn_socket, SOL_SOCKET, SO_SNDBUF, 278 &sockbuf, sizeof(sockbuf)) == -1) 279 log_warn("setsockopt(SO_SNDBUF) failed"); 280 if (conn->conn_conf.isc_dscp != -1) { 281 int tos = conn->conn_conf.isc_dscp << 2; 282 if (to_ai->ai_family == AF_INET) { 283 if (setsockopt(conn->conn_socket, 284 IPPROTO_IP, IP_TOS, 285 &tos, sizeof(tos)) == -1) 286 log_warn("setsockopt(IP_TOS) " 287 "failed for %s", 288 from_addr); 289 } else 290 if (to_ai->ai_family == AF_INET6) { 291 if (setsockopt(conn->conn_socket, 292 IPPROTO_IPV6, IPV6_TCLASS, 293 &tos, sizeof(tos)) == -1) 294 log_warn("setsockopt(IPV6_TCLASS) " 295 "failed for %s", 296 from_addr); 297 } 298 } 299 if (conn->conn_conf.isc_pcp != -1) { 300 int pcp = conn->conn_conf.isc_pcp; 301 if (to_ai->ai_family == AF_INET) { 302 if (setsockopt(conn->conn_socket, 303 IPPROTO_IP, IP_VLAN_PCP, 304 &pcp, sizeof(pcp)) == -1) 305 log_warn("setsockopt(IP_VLAN_PCP) " 306 "failed for %s", 307 from_addr); 308 } else 309 if (to_ai->ai_family == AF_INET6) { 310 if (setsockopt(conn->conn_socket, 311 IPPROTO_IPV6, IPV6_VLAN_PCP, 312 &pcp, sizeof(pcp)) == -1) 313 log_warn("setsockopt(IPV6_VLAN_PCP) " 314 "failed for %s", 315 from_addr); 316 } 317 } 318 if (from_ai != NULL) { 319 error = bind(conn->conn_socket, from_ai->ai_addr, 320 from_ai->ai_addrlen); 321 if (error != 0) { 322 fail(conn, strerror(errno)); 323 log_err(1, "failed to bind to %s", from_addr); 324 } 325 } 326 log_debugx("connecting to %s", to_addr); 327 error = connect(conn->conn_socket, to_ai->ai_addr, to_ai->ai_addrlen); 328 if (error != 0) { 329 fail(conn, strerror(errno)); 330 log_err(1, "failed to connect to %s", to_addr); 331 } 332 333 return (conn); 334 } 335 336 static void 337 handoff(struct connection *conn) 338 { 339 struct iscsi_daemon_handoff idh; 340 int error; 341 342 log_debugx("handing off connection to the kernel"); 343 344 memset(&idh, 0, sizeof(idh)); 345 idh.idh_session_id = conn->conn_session_id; 346 idh.idh_socket = conn->conn_socket; 347 strlcpy(idh.idh_target_alias, conn->conn_target_alias, 348 sizeof(idh.idh_target_alias)); 349 idh.idh_tsih = conn->conn_tsih; 350 idh.idh_statsn = conn->conn_statsn; 351 idh.idh_protocol_level = conn->conn_protocol_level; 352 idh.idh_header_digest = conn->conn_header_digest; 353 idh.idh_data_digest = conn->conn_data_digest; 354 idh.idh_initial_r2t = conn->conn_initial_r2t; 355 idh.idh_immediate_data = conn->conn_immediate_data; 356 idh.idh_max_recv_data_segment_length = 357 conn->conn_max_recv_data_segment_length; 358 idh.idh_max_send_data_segment_length = 359 conn->conn_max_send_data_segment_length; 360 idh.idh_max_burst_length = conn->conn_max_burst_length; 361 idh.idh_first_burst_length = conn->conn_first_burst_length; 362 363 error = ioctl(conn->conn_iscsi_fd, ISCSIDHANDOFF, &idh); 364 if (error != 0) 365 log_err(1, "ISCSIDHANDOFF"); 366 } 367 368 void 369 fail(const struct connection *conn, const char *reason) 370 { 371 struct iscsi_daemon_fail idf; 372 int error, saved_errno; 373 374 saved_errno = errno; 375 376 memset(&idf, 0, sizeof(idf)); 377 idf.idf_session_id = conn->conn_session_id; 378 strlcpy(idf.idf_reason, reason, sizeof(idf.idf_reason)); 379 380 error = ioctl(conn->conn_iscsi_fd, ISCSIDFAIL, &idf); 381 if (error != 0) 382 log_err(1, "ISCSIDFAIL"); 383 384 errno = saved_errno; 385 } 386 387 /* 388 * XXX: I CANT INTO LATIN 389 */ 390 static void 391 capsicate(struct connection *conn) 392 { 393 cap_rights_t rights; 394 #ifdef ICL_KERNEL_PROXY 395 const unsigned long cmds[] = { ISCSIDCONNECT, ISCSIDSEND, ISCSIDRECEIVE, 396 ISCSIDHANDOFF, ISCSIDFAIL, ISCSISADD, ISCSISREMOVE, ISCSISMODIFY }; 397 #else 398 const unsigned long cmds[] = { ISCSIDHANDOFF, ISCSIDFAIL, ISCSISADD, 399 ISCSISREMOVE, ISCSISMODIFY }; 400 #endif 401 402 cap_rights_init(&rights, CAP_IOCTL); 403 if (caph_rights_limit(conn->conn_iscsi_fd, &rights) < 0) 404 log_err(1, "cap_rights_limit"); 405 406 if (caph_ioctls_limit(conn->conn_iscsi_fd, cmds, nitems(cmds)) < 0) 407 log_err(1, "cap_ioctls_limit"); 408 409 if (caph_enter() != 0) 410 log_err(1, "cap_enter"); 411 412 if (cap_sandboxed()) 413 log_debugx("Capsicum capability mode enabled"); 414 else 415 log_warnx("Capsicum capability mode not supported"); 416 } 417 418 bool 419 timed_out(void) 420 { 421 422 return (sigalrm_received); 423 } 424 425 static void 426 sigalrm_handler(int dummy __unused) 427 { 428 /* 429 * It would be easiest to just log an error and exit. We can't 430 * do this, though, because log_errx() is not signal safe, since 431 * it calls syslog(3). Instead, set a flag checked by pdu_send() 432 * and pdu_receive(), to call log_errx() there. Should they fail 433 * to notice, we'll exit here one second later. 434 */ 435 if (sigalrm_received) { 436 /* 437 * Oh well. Just give up and quit. 438 */ 439 _exit(2); 440 } 441 442 sigalrm_received = true; 443 } 444 445 static void 446 set_timeout(int timeout) 447 { 448 struct sigaction sa; 449 struct itimerval itv; 450 int error; 451 452 if (timeout <= 0) { 453 log_debugx("session timeout disabled"); 454 return; 455 } 456 457 bzero(&sa, sizeof(sa)); 458 sa.sa_handler = sigalrm_handler; 459 sigfillset(&sa.sa_mask); 460 error = sigaction(SIGALRM, &sa, NULL); 461 if (error != 0) 462 log_err(1, "sigaction"); 463 464 /* 465 * First SIGALRM will arive after conf_timeout seconds. 466 * If we do nothing, another one will arrive a second later. 467 */ 468 bzero(&itv, sizeof(itv)); 469 itv.it_interval.tv_sec = 1; 470 itv.it_value.tv_sec = timeout; 471 472 log_debugx("setting session timeout to %d seconds", 473 timeout); 474 error = setitimer(ITIMER_REAL, &itv, NULL); 475 if (error != 0) 476 log_err(1, "setitimer"); 477 } 478 479 static void 480 sigchld_handler(int dummy __unused) 481 { 482 483 /* 484 * The only purpose of this handler is to make SIGCHLD 485 * interrupt the ISCSIDWAIT ioctl(2), so we can call 486 * wait_for_children(). 487 */ 488 } 489 490 static void 491 register_sigchld(void) 492 { 493 struct sigaction sa; 494 int error; 495 496 bzero(&sa, sizeof(sa)); 497 sa.sa_handler = sigchld_handler; 498 sigfillset(&sa.sa_mask); 499 error = sigaction(SIGCHLD, &sa, NULL); 500 if (error != 0) 501 log_err(1, "sigaction"); 502 503 } 504 505 static void 506 handle_request(int iscsi_fd, const struct iscsi_daemon_request *request, int timeout) 507 { 508 struct connection *conn; 509 510 log_set_peer_addr(request->idr_conf.isc_target_addr); 511 if (request->idr_conf.isc_target[0] != '\0') { 512 log_set_peer_name(request->idr_conf.isc_target); 513 setproctitle("%s (%s)", request->idr_conf.isc_target_addr, request->idr_conf.isc_target); 514 } else { 515 setproctitle("%s", request->idr_conf.isc_target_addr); 516 } 517 518 conn = connection_new(iscsi_fd, request); 519 set_timeout(timeout); 520 capsicate(conn); 521 login(conn); 522 if (conn->conn_conf.isc_discovery != 0) 523 discovery(conn); 524 else 525 handoff(conn); 526 527 log_debugx("nothing more to do; exiting"); 528 exit (0); 529 } 530 531 static int 532 wait_for_children(bool block) 533 { 534 pid_t pid; 535 int status; 536 int num = 0; 537 538 for (;;) { 539 /* 540 * If "block" is true, wait for at least one process. 541 */ 542 if (block && num == 0) 543 pid = wait4(-1, &status, 0, NULL); 544 else 545 pid = wait4(-1, &status, WNOHANG, NULL); 546 if (pid <= 0) 547 break; 548 if (WIFSIGNALED(status)) { 549 log_warnx("child process %d terminated with signal %d", 550 pid, WTERMSIG(status)); 551 } else if (WEXITSTATUS(status) != 0) { 552 log_warnx("child process %d terminated with exit status %d", 553 pid, WEXITSTATUS(status)); 554 } else { 555 log_debugx("child process %d terminated gracefully", pid); 556 } 557 num++; 558 } 559 560 return (num); 561 } 562 563 int 564 main(int argc, char **argv) 565 { 566 int ch, debug = 0, error, iscsi_fd, maxproc = 30, retval, saved_errno, 567 timeout = 60; 568 bool dont_daemonize = false; 569 struct pidfh *pidfh; 570 pid_t pid, otherpid; 571 const char *pidfile_path = DEFAULT_PIDFILE; 572 struct iscsi_daemon_request request; 573 574 while ((ch = getopt(argc, argv, "P:dl:m:t:")) != -1) { 575 switch (ch) { 576 case 'P': 577 pidfile_path = optarg; 578 break; 579 case 'd': 580 dont_daemonize = true; 581 debug++; 582 break; 583 case 'l': 584 debug = atoi(optarg); 585 break; 586 case 'm': 587 maxproc = atoi(optarg); 588 break; 589 case 't': 590 timeout = atoi(optarg); 591 break; 592 case '?': 593 default: 594 usage(); 595 } 596 } 597 argc -= optind; 598 if (argc != 0) 599 usage(); 600 601 log_init(debug); 602 603 pidfh = pidfile_open(pidfile_path, 0600, &otherpid); 604 if (pidfh == NULL) { 605 if (errno == EEXIST) 606 log_errx(1, "daemon already running, pid: %jd.", 607 (intmax_t)otherpid); 608 log_err(1, "cannot open or create pidfile \"%s\"", 609 pidfile_path); 610 } 611 612 iscsi_fd = open(ISCSI_PATH, O_RDWR); 613 if (iscsi_fd < 0 && errno == ENOENT) { 614 saved_errno = errno; 615 retval = kldload("iscsi"); 616 if (retval != -1) 617 iscsi_fd = open(ISCSI_PATH, O_RDWR); 618 else 619 errno = saved_errno; 620 } 621 if (iscsi_fd < 0) 622 log_err(1, "failed to open %s", ISCSI_PATH); 623 624 if (dont_daemonize == false) { 625 if (daemon(0, 0) == -1) { 626 log_warn("cannot daemonize"); 627 pidfile_remove(pidfh); 628 exit(1); 629 } 630 } 631 632 pidfile_write(pidfh); 633 634 register_sigchld(); 635 636 for (;;) { 637 log_debugx("waiting for request from the kernel"); 638 639 memset(&request, 0, sizeof(request)); 640 error = ioctl(iscsi_fd, ISCSIDWAIT, &request); 641 if (error != 0) { 642 if (errno == EINTR) { 643 nchildren -= wait_for_children(false); 644 assert(nchildren >= 0); 645 continue; 646 } 647 648 log_err(1, "ISCSIDWAIT"); 649 } 650 651 if (dont_daemonize) { 652 log_debugx("not forking due to -d flag; " 653 "will exit after servicing a single request"); 654 } else { 655 nchildren -= wait_for_children(false); 656 assert(nchildren >= 0); 657 658 while (maxproc > 0 && nchildren >= maxproc) { 659 log_debugx("maxproc limit of %d child processes hit; " 660 "waiting for child process to exit", maxproc); 661 nchildren -= wait_for_children(true); 662 assert(nchildren >= 0); 663 } 664 log_debugx("incoming connection; forking child process #%d", 665 nchildren); 666 nchildren++; 667 668 pid = fork(); 669 if (pid < 0) 670 log_err(1, "fork"); 671 if (pid > 0) 672 continue; 673 } 674 675 pidfile_close(pidfh); 676 handle_request(iscsi_fd, &request, timeout); 677 } 678 679 return (0); 680 } 681