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