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