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; 396 397 if (asprintf(&tmpfile, "%s%s", ZFS_EXPORTS_FILE, ".XXXXXXXX") == -1) { 398 fprintf(stderr, "Unable to allocate temporary file\n"); 399 return (NULL); 400 } 401 402 int fd = mkstemp(tmpfile); 403 if (fd == -1) { 404 fprintf(stderr, "Unable to create temporary file: %s", 405 strerror(errno)); 406 free(tmpfile); 407 return (NULL); 408 } 409 close(fd); 410 return (tmpfile); 411 } 412 413 static int 414 nfs_fini_tmpfile(char *tmpfile) 415 { 416 if (rename(tmpfile, ZFS_EXPORTS_FILE) == -1) { 417 fprintf(stderr, "Unable to rename %s: %s\n", tmpfile, 418 strerror(errno)); 419 unlink(tmpfile); 420 free(tmpfile); 421 return (SA_SYSTEM_ERR); 422 } 423 free(tmpfile); 424 return (SA_OK); 425 } 426 427 /* 428 * This function populates an entry into /etc/exports.d/zfs.exports. 429 * This file is consumed by the linux nfs server so that zfs shares are 430 * automatically exported upon boot or whenever the nfs server restarts. 431 */ 432 static int 433 nfs_add_entry(const char *filename, const char *sharepath, 434 const char *host, const char *security, const char *access_opts, 435 void *pcookie) 436 { 437 int error; 438 char *linuxhost; 439 const char *linux_opts = (const char *)pcookie; 440 441 error = get_linux_hostspec(host, &linuxhost); 442 if (error != SA_OK) 443 return (error); 444 445 if (linux_opts == NULL) 446 linux_opts = ""; 447 448 FILE *fp = fopen(filename, "a+"); 449 if (fp == NULL) { 450 fprintf(stderr, "failed to open %s file: %s", filename, 451 strerror(errno)); 452 free(linuxhost); 453 return (SA_SYSTEM_ERR); 454 } 455 456 if (fprintf(fp, "%s %s(sec=%s,%s,%s)\n", sharepath, linuxhost, 457 security, access_opts, linux_opts) < 0) { 458 fprintf(stderr, "failed to write to %s\n", filename); 459 free(linuxhost); 460 fclose(fp); 461 return (SA_SYSTEM_ERR); 462 } 463 464 free(linuxhost); 465 if (fclose(fp) != 0) { 466 fprintf(stderr, "Unable to close file %s: %s\n", 467 filename, strerror(errno)); 468 return (SA_SYSTEM_ERR); 469 } 470 return (SA_OK); 471 } 472 473 /* 474 * This function copies all entries from the exports file to "filename", 475 * omitting any entries for the specified mountpoint. 476 */ 477 static int 478 nfs_copy_entries(char *filename, const char *mountpoint) 479 { 480 char *buf = NULL; 481 size_t buflen = 0; 482 int error = SA_OK; 483 484 /* 485 * If the file doesn't exist then there is nothing more 486 * we need to do. 487 */ 488 FILE *oldfp = fopen(ZFS_EXPORTS_FILE, "r"); 489 if (oldfp == NULL) 490 return (SA_OK); 491 492 FILE *newfp = fopen(filename, "w+"); 493 fputs(FILE_HEADER, newfp); 494 while ((getline(&buf, &buflen, oldfp)) != -1) { 495 char *space = NULL; 496 497 if (buf[0] == '\n' || buf[0] == '#') 498 continue; 499 500 if ((space = strchr(buf, ' ')) != NULL) { 501 int mountpoint_len = strlen(mountpoint); 502 503 if (space - buf == mountpoint_len && 504 strncmp(mountpoint, buf, mountpoint_len) == 0) { 505 continue; 506 } 507 } 508 fputs(buf, newfp); 509 } 510 511 if (oldfp != NULL && ferror(oldfp) != 0) { 512 error = ferror(oldfp); 513 } 514 if (error == 0 && ferror(newfp) != 0) { 515 error = ferror(newfp); 516 } 517 518 free(buf); 519 if (fclose(newfp) != 0) { 520 fprintf(stderr, "Unable to close file %s: %s\n", 521 filename, strerror(errno)); 522 error = error != 0 ? error : SA_SYSTEM_ERR; 523 } 524 fclose(oldfp); 525 526 return (error); 527 } 528 529 /* 530 * Enables NFS sharing for the specified share. 531 */ 532 static int 533 nfs_enable_share(sa_share_impl_t impl_share) 534 { 535 char *shareopts, *linux_opts; 536 char *filename = NULL; 537 int error; 538 539 if ((filename = nfs_init_tmpfile()) == NULL) 540 return (SA_SYSTEM_ERR); 541 542 error = nfs_exports_lock(); 543 if (error != 0) { 544 unlink(filename); 545 free(filename); 546 return (error); 547 } 548 549 error = nfs_copy_entries(filename, impl_share->sa_mountpoint); 550 if (error != SA_OK) { 551 unlink(filename); 552 free(filename); 553 nfs_exports_unlock(); 554 return (error); 555 } 556 557 shareopts = FSINFO(impl_share, nfs_fstype)->shareopts; 558 error = get_linux_shareopts(shareopts, &linux_opts); 559 if (error != SA_OK) { 560 unlink(filename); 561 free(filename); 562 nfs_exports_unlock(); 563 return (error); 564 } 565 566 error = foreach_nfs_host(impl_share, filename, nfs_add_entry, 567 linux_opts); 568 free(linux_opts); 569 if (error == 0) { 570 error = nfs_fini_tmpfile(filename); 571 } else { 572 unlink(filename); 573 free(filename); 574 } 575 nfs_exports_unlock(); 576 return (error); 577 } 578 579 /* 580 * Disables NFS sharing for the specified share. 581 */ 582 static int 583 nfs_disable_share(sa_share_impl_t impl_share) 584 { 585 int error; 586 char *filename = NULL; 587 588 if ((filename = nfs_init_tmpfile()) == NULL) 589 return (SA_SYSTEM_ERR); 590 591 error = nfs_exports_lock(); 592 if (error != 0) { 593 unlink(filename); 594 free(filename); 595 return (error); 596 } 597 598 error = nfs_copy_entries(filename, impl_share->sa_mountpoint); 599 if (error != SA_OK) { 600 unlink(filename); 601 free(filename); 602 nfs_exports_unlock(); 603 return (error); 604 } 605 error = nfs_fini_tmpfile(filename); 606 nfs_exports_unlock(); 607 return (error); 608 } 609 610 static boolean_t 611 nfs_is_shared(sa_share_impl_t impl_share) 612 { 613 size_t buflen = 0; 614 char *buf = NULL; 615 616 FILE *fp = fopen(ZFS_EXPORTS_FILE, "r"); 617 if (fp == NULL) { 618 return (B_FALSE); 619 } 620 while ((getline(&buf, &buflen, fp)) != -1) { 621 char *space = NULL; 622 623 if ((space = strchr(buf, ' ')) != NULL) { 624 int mountpoint_len = strlen(impl_share->sa_mountpoint); 625 626 if (space - buf == mountpoint_len && 627 strncmp(impl_share->sa_mountpoint, buf, 628 mountpoint_len) == 0) { 629 fclose(fp); 630 free(buf); 631 return (B_TRUE); 632 } 633 } 634 } 635 free(buf); 636 fclose(fp); 637 return (B_FALSE); 638 } 639 640 /* 641 * Checks whether the specified NFS share options are syntactically correct. 642 */ 643 static int 644 nfs_validate_shareopts(const char *shareopts) 645 { 646 char *linux_opts; 647 int error; 648 649 error = get_linux_shareopts(shareopts, &linux_opts); 650 651 if (error != SA_OK) 652 return (error); 653 654 free(linux_opts); 655 return (SA_OK); 656 } 657 658 static int 659 nfs_update_shareopts(sa_share_impl_t impl_share, const char *shareopts) 660 { 661 FSINFO(impl_share, nfs_fstype)->shareopts = (char *)shareopts; 662 return (SA_OK); 663 } 664 665 /* 666 * Clears a share's NFS options. Used by libshare to 667 * clean up shares that are about to be free()'d. 668 */ 669 static void 670 nfs_clear_shareopts(sa_share_impl_t impl_share) 671 { 672 FSINFO(impl_share, nfs_fstype)->shareopts = NULL; 673 } 674 675 static int 676 nfs_commit_shares(void) 677 { 678 char *argv[] = { 679 "/usr/sbin/exportfs", 680 "-ra", 681 NULL 682 }; 683 684 return (libzfs_run_process(argv[0], argv, 0)); 685 } 686 687 static const sa_share_ops_t nfs_shareops = { 688 .enable_share = nfs_enable_share, 689 .disable_share = nfs_disable_share, 690 .is_shared = nfs_is_shared, 691 692 .validate_shareopts = nfs_validate_shareopts, 693 .update_shareopts = nfs_update_shareopts, 694 .clear_shareopts = nfs_clear_shareopts, 695 .commit_shares = nfs_commit_shares, 696 }; 697 698 /* 699 * Initializes the NFS functionality of libshare. 700 */ 701 void 702 libshare_nfs_init(void) 703 { 704 struct stat sb; 705 706 nfs_fstype = register_fstype("nfs", &nfs_shareops); 707 708 if (stat(ZFS_EXPORTS_DIR, &sb) < 0 && 709 mkdir(ZFS_EXPORTS_DIR, 0755) < 0) { 710 fprintf(stderr, "failed to create %s: %s\n", 711 ZFS_EXPORTS_DIR, strerror(errno)); 712 } 713 } 714