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