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