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