1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved. 24 * Copyright (c) 2011 Gunnar Beutner 25 * Copyright (c) 2012 Cyril Plisko. All rights reserved. 26 * Copyright (c) 2019, 2020 by Delphix. All rights reserved. 27 */ 28 29 #include <dirent.h> 30 #include <stdio.h> 31 #include <string.h> 32 #include <strings.h> 33 #include <errno.h> 34 #include <fcntl.h> 35 #include <sys/file.h> 36 #include <sys/stat.h> 37 #include <sys/types.h> 38 #include <sys/wait.h> 39 #include <unistd.h> 40 #include <libzfs.h> 41 #include <libshare.h> 42 #include "libshare_impl.h" 43 #include "nfs.h" 44 45 #define FILE_HEADER "# !!! DO NOT EDIT THIS FILE MANUALLY !!!\n\n" 46 #define ZFS_EXPORTS_DIR "/etc/exports.d" 47 #define ZFS_EXPORTS_FILE ZFS_EXPORTS_DIR"/zfs.exports" 48 #define ZFS_EXPORTS_LOCK ZFS_EXPORTS_FILE".lock" 49 50 static sa_fstype_t *nfs_fstype; 51 52 typedef int (*nfs_shareopt_callback_t)(const char *opt, const char *value, 53 void *cookie); 54 55 typedef int (*nfs_host_callback_t)(const char *sharepath, const char *filename, 56 const char *host, const char *security, const char *access, void *cookie); 57 58 static int nfs_lock_fd = -1; 59 60 /* 61 * The nfs_exports_[lock|unlock] is used to guard against conconcurrent 62 * updates to the exports file. Each protocol is responsible for 63 * providing the necessary locking to ensure consistency. 64 */ 65 static int 66 nfs_exports_lock(void) 67 { 68 nfs_lock_fd = open(ZFS_EXPORTS_LOCK, 69 O_RDWR | O_CREAT, 0600); 70 if (nfs_lock_fd == -1) { 71 fprintf(stderr, "failed to lock %s: %s\n", 72 ZFS_EXPORTS_LOCK, strerror(errno)); 73 return (errno); 74 } 75 if (flock(nfs_lock_fd, LOCK_EX) != 0) { 76 fprintf(stderr, "failed to lock %s: %s\n", 77 ZFS_EXPORTS_LOCK, strerror(errno)); 78 return (errno); 79 } 80 return (0); 81 } 82 83 static void 84 nfs_exports_unlock(void) 85 { 86 verify(nfs_lock_fd > 0); 87 88 if (flock(nfs_lock_fd, LOCK_UN) != 0) { 89 fprintf(stderr, "failed to unlock %s: %s\n", 90 ZFS_EXPORTS_LOCK, strerror(errno)); 91 } 92 close(nfs_lock_fd); 93 nfs_lock_fd = -1; 94 } 95 96 /* 97 * Invokes the specified callback function for each Solaris share option 98 * listed in the specified string. 99 */ 100 static int 101 foreach_nfs_shareopt(const char *shareopts, 102 nfs_shareopt_callback_t callback, void *cookie) 103 { 104 char *shareopts_dup, *opt, *cur, *value; 105 int was_nul, error; 106 107 if (shareopts == NULL) 108 return (SA_OK); 109 110 if (strcmp(shareopts, "on") == 0) 111 shareopts = "rw,crossmnt"; 112 113 shareopts_dup = strdup(shareopts); 114 115 116 if (shareopts_dup == NULL) 117 return (SA_NO_MEMORY); 118 119 opt = shareopts_dup; 120 was_nul = 0; 121 122 while (1) { 123 cur = opt; 124 125 while (*cur != ',' && *cur != '\0') 126 cur++; 127 128 if (*cur == '\0') 129 was_nul = 1; 130 131 *cur = '\0'; 132 133 if (cur > opt) { 134 value = strchr(opt, '='); 135 136 if (value != NULL) { 137 *value = '\0'; 138 value++; 139 } 140 141 error = callback(opt, value, cookie); 142 143 if (error != SA_OK) { 144 free(shareopts_dup); 145 return (error); 146 } 147 } 148 149 opt = cur + 1; 150 151 if (was_nul) 152 break; 153 } 154 155 free(shareopts_dup); 156 157 return (SA_OK); 158 } 159 160 typedef struct nfs_host_cookie_s { 161 nfs_host_callback_t callback; 162 const char *sharepath; 163 void *cookie; 164 const char *filename; 165 const char *security; 166 } nfs_host_cookie_t; 167 168 /* 169 * Helper function for foreach_nfs_host. This function checks whether the 170 * current share option is a host specification and invokes a callback 171 * function with information about the host. 172 */ 173 static int 174 foreach_nfs_host_cb(const char *opt, const char *value, void *pcookie) 175 { 176 int error; 177 const char *access; 178 char *host_dup, *host, *next; 179 nfs_host_cookie_t *udata = (nfs_host_cookie_t *)pcookie; 180 181 #ifdef DEBUG 182 fprintf(stderr, "foreach_nfs_host_cb: key=%s, value=%s\n", opt, value); 183 #endif 184 185 if (strcmp(opt, "sec") == 0) 186 udata->security = value; 187 188 if (strcmp(opt, "rw") == 0 || strcmp(opt, "ro") == 0) { 189 if (value == NULL) 190 value = "*"; 191 192 access = opt; 193 194 host_dup = strdup(value); 195 196 if (host_dup == NULL) 197 return (SA_NO_MEMORY); 198 199 host = host_dup; 200 201 do { 202 next = strchr(host, ':'); 203 if (next != NULL) { 204 *next = '\0'; 205 next++; 206 } 207 208 error = udata->callback(udata->filename, 209 udata->sharepath, host, udata->security, 210 access, udata->cookie); 211 212 if (error != SA_OK) { 213 free(host_dup); 214 215 return (error); 216 } 217 218 host = next; 219 } while (host != NULL); 220 221 free(host_dup); 222 } 223 224 return (SA_OK); 225 } 226 227 /* 228 * Invokes a callback function for all NFS hosts that are set for a share. 229 */ 230 static int 231 foreach_nfs_host(sa_share_impl_t impl_share, char *filename, 232 nfs_host_callback_t callback, void *cookie) 233 { 234 nfs_host_cookie_t udata; 235 char *shareopts; 236 237 udata.callback = callback; 238 udata.sharepath = impl_share->sa_mountpoint; 239 udata.cookie = cookie; 240 udata.filename = filename; 241 udata.security = "sys"; 242 243 shareopts = FSINFO(impl_share, nfs_fstype)->shareopts; 244 245 return (foreach_nfs_shareopt(shareopts, foreach_nfs_host_cb, 246 &udata)); 247 } 248 249 /* 250 * Converts a Solaris NFS host specification to its Linux equivalent. 251 */ 252 static int 253 get_linux_hostspec(const char *solaris_hostspec, char **plinux_hostspec) 254 { 255 /* 256 * For now we just support CIDR masks (e.g. @192.168.0.0/16) and host 257 * wildcards (e.g. *.example.org). 258 */ 259 if (solaris_hostspec[0] == '@') { 260 /* 261 * Solaris host specifier, e.g. @192.168.0.0/16; we just need 262 * to skip the @ in this case 263 */ 264 *plinux_hostspec = strdup(solaris_hostspec + 1); 265 } else { 266 *plinux_hostspec = strdup(solaris_hostspec); 267 } 268 269 if (*plinux_hostspec == NULL) { 270 return (SA_NO_MEMORY); 271 } 272 273 return (SA_OK); 274 } 275 276 /* 277 * Adds a Linux share option to an array of NFS options. 278 */ 279 static int 280 add_linux_shareopt(char **plinux_opts, const char *key, const char *value) 281 { 282 size_t len = 0; 283 char *new_linux_opts; 284 285 if (*plinux_opts != NULL) 286 len = strlen(*plinux_opts); 287 288 new_linux_opts = realloc(*plinux_opts, len + 1 + strlen(key) + 289 (value ? 1 + strlen(value) : 0) + 1); 290 291 if (new_linux_opts == NULL) 292 return (SA_NO_MEMORY); 293 294 new_linux_opts[len] = '\0'; 295 296 if (len > 0) 297 strcat(new_linux_opts, ","); 298 299 strcat(new_linux_opts, key); 300 301 if (value != NULL) { 302 strcat(new_linux_opts, "="); 303 strcat(new_linux_opts, value); 304 } 305 306 *plinux_opts = new_linux_opts; 307 308 return (SA_OK); 309 } 310 311 /* 312 * Validates and converts a single Solaris share option to its Linux 313 * equivalent. 314 */ 315 static int 316 get_linux_shareopts_cb(const char *key, const char *value, void *cookie) 317 { 318 char **plinux_opts = (char **)cookie; 319 320 /* host-specific options, these are taken care of elsewhere */ 321 if (strcmp(key, "ro") == 0 || strcmp(key, "rw") == 0 || 322 strcmp(key, "sec") == 0) 323 return (SA_OK); 324 325 if (strcmp(key, "anon") == 0) 326 key = "anonuid"; 327 328 if (strcmp(key, "root_mapping") == 0) { 329 (void) add_linux_shareopt(plinux_opts, "root_squash", NULL); 330 key = "anonuid"; 331 } 332 333 if (strcmp(key, "nosub") == 0) 334 key = "subtree_check"; 335 336 if (strcmp(key, "insecure") != 0 && strcmp(key, "secure") != 0 && 337 strcmp(key, "async") != 0 && strcmp(key, "sync") != 0 && 338 strcmp(key, "no_wdelay") != 0 && strcmp(key, "wdelay") != 0 && 339 strcmp(key, "nohide") != 0 && strcmp(key, "hide") != 0 && 340 strcmp(key, "crossmnt") != 0 && 341 strcmp(key, "no_subtree_check") != 0 && 342 strcmp(key, "subtree_check") != 0 && 343 strcmp(key, "insecure_locks") != 0 && 344 strcmp(key, "secure_locks") != 0 && 345 strcmp(key, "no_auth_nlm") != 0 && strcmp(key, "auth_nlm") != 0 && 346 strcmp(key, "no_acl") != 0 && strcmp(key, "mountpoint") != 0 && 347 strcmp(key, "mp") != 0 && strcmp(key, "fsuid") != 0 && 348 strcmp(key, "refer") != 0 && strcmp(key, "replicas") != 0 && 349 strcmp(key, "root_squash") != 0 && 350 strcmp(key, "no_root_squash") != 0 && 351 strcmp(key, "all_squash") != 0 && 352 strcmp(key, "no_all_squash") != 0 && strcmp(key, "fsid") != 0 && 353 strcmp(key, "anonuid") != 0 && strcmp(key, "anongid") != 0) { 354 return (SA_SYNTAX_ERR); 355 } 356 357 (void) add_linux_shareopt(plinux_opts, key, value); 358 359 return (SA_OK); 360 } 361 362 /* 363 * Takes a string containing Solaris share options (e.g. "sync,no_acl") and 364 * converts them to a NULL-terminated array of Linux NFS options. 365 */ 366 static int 367 get_linux_shareopts(const char *shareopts, char **plinux_opts) 368 { 369 int error; 370 371 assert(plinux_opts != NULL); 372 373 *plinux_opts = NULL; 374 375 /* no_subtree_check - Default as of nfs-utils v1.1.0 */ 376 (void) add_linux_shareopt(plinux_opts, "no_subtree_check", NULL); 377 378 /* mountpoint - Restrict exports to ZFS mountpoints */ 379 (void) add_linux_shareopt(plinux_opts, "mountpoint", NULL); 380 381 error = foreach_nfs_shareopt(shareopts, get_linux_shareopts_cb, 382 plinux_opts); 383 384 if (error != SA_OK) { 385 free(*plinux_opts); 386 *plinux_opts = NULL; 387 } 388 389 return (error); 390 } 391 392 static char * 393 nfs_init_tmpfile(void) 394 { 395 char *tmpfile = NULL; 396 struct stat sb; 397 398 if (stat(ZFS_EXPORTS_DIR, &sb) < 0 && 399 mkdir(ZFS_EXPORTS_DIR, 0755) < 0) { 400 fprintf(stderr, "failed to create %s: %s\n", 401 ZFS_EXPORTS_DIR, strerror(errno)); 402 return (NULL); 403 } 404 405 if (asprintf(&tmpfile, "%s%s", ZFS_EXPORTS_FILE, ".XXXXXXXX") == -1) { 406 fprintf(stderr, "Unable to allocate temporary file\n"); 407 return (NULL); 408 } 409 410 int fd = mkstemp(tmpfile); 411 if (fd == -1) { 412 fprintf(stderr, "Unable to create temporary file: %s", 413 strerror(errno)); 414 free(tmpfile); 415 return (NULL); 416 } 417 close(fd); 418 return (tmpfile); 419 } 420 421 static int 422 nfs_fini_tmpfile(char *tmpfile) 423 { 424 if (rename(tmpfile, ZFS_EXPORTS_FILE) == -1) { 425 fprintf(stderr, "Unable to rename %s: %s\n", tmpfile, 426 strerror(errno)); 427 unlink(tmpfile); 428 free(tmpfile); 429 return (SA_SYSTEM_ERR); 430 } 431 free(tmpfile); 432 return (SA_OK); 433 } 434 435 /* 436 * This function populates an entry into /etc/exports.d/zfs.exports. 437 * This file is consumed by the linux nfs server so that zfs shares are 438 * automatically exported upon boot or whenever the nfs server restarts. 439 */ 440 static int 441 nfs_add_entry(const char *filename, const char *sharepath, 442 const char *host, const char *security, const char *access_opts, 443 void *pcookie) 444 { 445 int error; 446 char *linuxhost; 447 const char *linux_opts = (const char *)pcookie; 448 449 error = get_linux_hostspec(host, &linuxhost); 450 if (error != SA_OK) 451 return (error); 452 453 if (linux_opts == NULL) 454 linux_opts = ""; 455 456 FILE *fp = fopen(filename, "a+"); 457 if (fp == NULL) { 458 fprintf(stderr, "failed to open %s file: %s", filename, 459 strerror(errno)); 460 free(linuxhost); 461 return (SA_SYSTEM_ERR); 462 } 463 464 if (fprintf(fp, "%s %s(sec=%s,%s,%s)\n", sharepath, linuxhost, 465 security, access_opts, linux_opts) < 0) { 466 fprintf(stderr, "failed to write to %s\n", filename); 467 free(linuxhost); 468 fclose(fp); 469 return (SA_SYSTEM_ERR); 470 } 471 472 free(linuxhost); 473 if (fclose(fp) != 0) { 474 fprintf(stderr, "Unable to close file %s: %s\n", 475 filename, strerror(errno)); 476 return (SA_SYSTEM_ERR); 477 } 478 return (SA_OK); 479 } 480 481 /* 482 * This function copies all entries from the exports file to "filename", 483 * omitting any entries for the specified mountpoint. 484 */ 485 static int 486 nfs_copy_entries(char *filename, const char *mountpoint) 487 { 488 char *buf = NULL; 489 size_t buflen = 0; 490 int error = SA_OK; 491 492 FILE *oldfp = fopen(ZFS_EXPORTS_FILE, "r"); 493 FILE *newfp = fopen(filename, "w+"); 494 if (newfp == NULL) { 495 fprintf(stderr, "failed to open %s file: %s", filename, 496 strerror(errno)); 497 fclose(oldfp); 498 return (SA_SYSTEM_ERR); 499 } 500 fputs(FILE_HEADER, newfp); 501 502 /* 503 * The ZFS_EXPORTS_FILE may not exist yet. If that's the 504 * case then just write out the new file. 505 */ 506 if (oldfp != NULL) { 507 while (getline(&buf, &buflen, oldfp) != -1) { 508 char *space = NULL; 509 510 if (buf[0] == '\n' || buf[0] == '#') 511 continue; 512 513 if ((space = strchr(buf, ' ')) != NULL) { 514 int mountpoint_len = strlen(mountpoint); 515 516 if (space - buf == mountpoint_len && 517 strncmp(mountpoint, buf, 518 mountpoint_len) == 0) { 519 continue; 520 } 521 } 522 fputs(buf, newfp); 523 } 524 525 if (ferror(oldfp) != 0) { 526 error = ferror(oldfp); 527 } 528 if (fclose(oldfp) != 0) { 529 fprintf(stderr, "Unable to close file %s: %s\n", 530 filename, strerror(errno)); 531 error = error != 0 ? error : SA_SYSTEM_ERR; 532 } 533 } 534 535 if (error == 0 && ferror(newfp) != 0) { 536 error = ferror(newfp); 537 } 538 539 free(buf); 540 if (fclose(newfp) != 0) { 541 fprintf(stderr, "Unable to close file %s: %s\n", 542 filename, strerror(errno)); 543 error = error != 0 ? error : SA_SYSTEM_ERR; 544 } 545 return (error); 546 } 547 548 /* 549 * Enables NFS sharing for the specified share. 550 */ 551 static int 552 nfs_enable_share(sa_share_impl_t impl_share) 553 { 554 char *shareopts, *linux_opts; 555 char *filename = NULL; 556 int error; 557 558 if ((filename = nfs_init_tmpfile()) == NULL) 559 return (SA_SYSTEM_ERR); 560 561 error = nfs_exports_lock(); 562 if (error != 0) { 563 unlink(filename); 564 free(filename); 565 return (error); 566 } 567 568 error = nfs_copy_entries(filename, impl_share->sa_mountpoint); 569 if (error != SA_OK) { 570 unlink(filename); 571 free(filename); 572 nfs_exports_unlock(); 573 return (error); 574 } 575 576 shareopts = FSINFO(impl_share, nfs_fstype)->shareopts; 577 error = get_linux_shareopts(shareopts, &linux_opts); 578 if (error != SA_OK) { 579 unlink(filename); 580 free(filename); 581 nfs_exports_unlock(); 582 return (error); 583 } 584 585 error = foreach_nfs_host(impl_share, filename, nfs_add_entry, 586 linux_opts); 587 free(linux_opts); 588 if (error == 0) { 589 error = nfs_fini_tmpfile(filename); 590 } else { 591 unlink(filename); 592 free(filename); 593 } 594 nfs_exports_unlock(); 595 return (error); 596 } 597 598 /* 599 * Disables NFS sharing for the specified share. 600 */ 601 static int 602 nfs_disable_share(sa_share_impl_t impl_share) 603 { 604 int error; 605 char *filename = NULL; 606 607 if ((filename = nfs_init_tmpfile()) == NULL) 608 return (SA_SYSTEM_ERR); 609 610 error = nfs_exports_lock(); 611 if (error != 0) { 612 unlink(filename); 613 free(filename); 614 return (error); 615 } 616 617 error = nfs_copy_entries(filename, impl_share->sa_mountpoint); 618 if (error != SA_OK) { 619 unlink(filename); 620 free(filename); 621 nfs_exports_unlock(); 622 return (error); 623 } 624 error = nfs_fini_tmpfile(filename); 625 nfs_exports_unlock(); 626 return (error); 627 } 628 629 static boolean_t 630 nfs_is_shared(sa_share_impl_t impl_share) 631 { 632 size_t buflen = 0; 633 char *buf = NULL; 634 635 FILE *fp = fopen(ZFS_EXPORTS_FILE, "r"); 636 if (fp == NULL) { 637 return (B_FALSE); 638 } 639 while ((getline(&buf, &buflen, fp)) != -1) { 640 char *space = NULL; 641 642 if ((space = strchr(buf, ' ')) != NULL) { 643 int mountpoint_len = strlen(impl_share->sa_mountpoint); 644 645 if (space - buf == mountpoint_len && 646 strncmp(impl_share->sa_mountpoint, buf, 647 mountpoint_len) == 0) { 648 fclose(fp); 649 free(buf); 650 return (B_TRUE); 651 } 652 } 653 } 654 free(buf); 655 fclose(fp); 656 return (B_FALSE); 657 } 658 659 /* 660 * Checks whether the specified NFS share options are syntactically correct. 661 */ 662 static int 663 nfs_validate_shareopts(const char *shareopts) 664 { 665 char *linux_opts; 666 int error; 667 668 error = get_linux_shareopts(shareopts, &linux_opts); 669 670 if (error != SA_OK) 671 return (error); 672 673 free(linux_opts); 674 return (SA_OK); 675 } 676 677 static int 678 nfs_update_shareopts(sa_share_impl_t impl_share, const char *shareopts) 679 { 680 FSINFO(impl_share, nfs_fstype)->shareopts = (char *)shareopts; 681 return (SA_OK); 682 } 683 684 /* 685 * Clears a share's NFS options. Used by libshare to 686 * clean up shares that are about to be free()'d. 687 */ 688 static void 689 nfs_clear_shareopts(sa_share_impl_t impl_share) 690 { 691 FSINFO(impl_share, nfs_fstype)->shareopts = NULL; 692 } 693 694 static int 695 nfs_commit_shares(void) 696 { 697 char *argv[] = { 698 "/usr/sbin/exportfs", 699 "-ra", 700 NULL 701 }; 702 703 return (libzfs_run_process(argv[0], argv, 0)); 704 } 705 706 static const sa_share_ops_t nfs_shareops = { 707 .enable_share = nfs_enable_share, 708 .disable_share = nfs_disable_share, 709 .is_shared = nfs_is_shared, 710 711 .validate_shareopts = nfs_validate_shareopts, 712 .update_shareopts = nfs_update_shareopts, 713 .clear_shareopts = nfs_clear_shareopts, 714 .commit_shares = nfs_commit_shares, 715 }; 716 717 /* 718 * Initializes the NFS functionality of libshare. 719 */ 720 void 721 libshare_nfs_init(void) 722 { 723 nfs_fstype = register_fstype("nfs", &nfs_shareops); 724 } 725