sbin/hammer/cmd_pseudofs.c

   1 /*
   2  * Copyright (c) 2008 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Matthew Dillon <dillon@backplane.com>
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  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
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  * $DragonFly: src/sbin/hammer/cmd_pseudofs.c,v 1.12 2008/10/08 21:01:54 thomas Exp $
  35  */
  36
  37 #include "hammer.h"
  38
  39 static void parse_pfsd_options(char **av, int ac, hammer_pseudofs_data_t pfsd);
  40 static void init_pfsd(hammer_pseudofs_data_t pfsd, int is_slave);
  41 static void dump_pfsd(hammer_pseudofs_data_t pfsd);
  42 static void pseudofs_usage(int code);
  43 static int getyn(void);
  44
  45 /*
  46  * Calculate the pfs_id given a path to a directory or a @@PFS or @@%llx:%d
  47  * softlink.
  48  */
  49 int
  50 getpfs(struct hammer_ioc_pseudofs_rw *pfs, const char *path)
  51 {
  52         hammer_tid_t dummy_tid;
  53         struct stat st;
  54         char *dirpath;
  55         char buf[64];
  56         int fd;
  57         int n;
  58
  59         bzero(pfs, sizeof(*pfs));
  60         pfs->ondisk = malloc(sizeof(*pfs->ondisk));
  61         bzero(pfs->ondisk, sizeof(*pfs->ondisk));
  62         pfs->bytes = sizeof(*pfs->ondisk);
  63
  64         /*
  65          * Calculate the directory containing the softlink
  66          */
  67         dirpath = strdup(path);
  68         if (strrchr(dirpath, '/')) {
  69                 *strrchr(dirpath, '/') = 0;
  70                 if (strlen(dirpath) == 0) {
  71                         free(dirpath);
  72                         dirpath = strdup("/");
  73                 }
  74         } else {
  75                 free(dirpath);
  76                 dirpath = strdup(".");
  77         }
  78
  79         if (lstat(path, &st) == 0 && S_ISLNK(st.st_mode)) {
  80                 /*
  81                  * Avoid foot-shooting.  Don't let the user access a PFS
  82                  * softlink via a PFS.  PFS softlinks may only be accessed
  83                  * via the master filesystem.
  84                  */
  85                 fd = open(dirpath, O_RDONLY);
  86                 if (fd < 0)
  87                         goto done;
  88                 pfs->pfs_id = -1;
  89                 ioctl(fd, HAMMERIOC_GET_PSEUDOFS, pfs);
  90                 if (pfs->pfs_id != 0) {
  91                         fprintf(stderr,
  92                                 "You are attempting to access a PFS softlink "
  93                                 "from a PFS.  It may not represent the PFS\n"
  94                                 "on the main filesystem mount that you "
  95                                 "expect!  You may only access PFS softlinks\n"
  96                                 "via the main filesystem mount!\n");
  97                         exit(1);
  98                 }
  99                 close(fd);
 100
 101                 /*
 102                  * Extract the PFS from the link.  HAMMER will automatically
 103                  * convert @@PFS%05d links so if actually see one in that
 104                  * form the target PFS may not exist or may be corrupt.  But
 105                  * we can extract the PFS id anyway.
 106                  */
 107                 n = readlink(path, buf, sizeof(buf) - 1);
 108                 if (n < 0)
 109                         n = 0;
 110                 buf[n] = 0;
 111                 if (sscanf(buf, "@@PFS%d", &pfs->pfs_id) == 1) {
 112                         fd = open(dirpath, O_RDONLY);
 113                         goto done;
 114                 }
 115                 if (sscanf(buf, "@@%llx:%d", &dummy_tid, &pfs->pfs_id) == 2) {
 116                         fd = open(dirpath, O_RDONLY);
 117                         goto done;
 118                 }
 119         }
 120
 121         /*
 122          * Try to open the path and request the pfs_id that way.
 123          */
 124         fd = open(path, O_RDONLY);
 125         if (fd >= 0) {
 126                 pfs->pfs_id = -1;
 127                 ioctl(fd, HAMMERIOC_GET_PSEUDOFS, pfs);
 128                 if (pfs->pfs_id == -1) {
 129                         close(fd);
 130                         fd = -1;
 131                 }
 132         }
 133
 134         /*
 135          * Cleanup
 136          */
 137 done:
 138         if (fd < 0) {
 139                 fprintf(stderr, "Cannot access PFS %s: %s\n",
 140                         path, strerror(errno));
 141                 exit(1);
 142         }
 143         if (ioctl(fd, HAMMERIOC_GET_PSEUDOFS, pfs) < 0) {
 144                 fprintf(stderr, "Cannot access PFS %s: %s\n",
 145                         path, strerror(errno));
 146                 exit(1);
 147         }
 148         free(dirpath);
 149         return(fd);
 150 }
 151
 152 void
 153 relpfs(int fd, struct hammer_ioc_pseudofs_rw *pfs)
 154 {
 155         close(fd);
 156         if (pfs->ondisk) {
 157                 free(pfs->ondisk);
 158                 pfs->ondisk = NULL;
 159         }
 160 }
 161
 162 void
 163 hammer_cmd_pseudofs_status(char **av, int ac)
 164 {
 165         struct hammer_ioc_pseudofs_rw pfs;
 166         int i;
 167         int fd;
 168
 169         if (ac == 0)
 170                 pseudofs_usage(1);
 171
 172         for (i = 0; i < ac; ++i) {
 173                 printf("%s\t", av[i]);
 174                 fd = getpfs(&pfs, av[i]);
 175                 if (fd < 0 || ioctl(fd, HAMMERIOC_GET_PSEUDOFS, &pfs) < 0) {
 176                         printf("Not a HAMMER root\n");
 177                 } else {
 178                         printf("PFS #%d {\n", pfs.pfs_id);
 179                         dump_pfsd(pfs.ondisk);
 180                         printf("}\n");
 181                 }
 182                 if (fd >= 0)
 183                         close(fd);
 184                 if (pfs.ondisk)
 185                         free(pfs.ondisk);
 186         }
 187 }
 188
 189 void
 190 hammer_cmd_pseudofs_create(char **av, int ac, int is_slave)
 191 {
 192         struct hammer_ioc_pseudofs_rw pfs;
 193         struct hammer_pseudofs_data pfsd;
 194         struct stat st;
 195         const char *path;
 196         char *dirpath;
 197         char *linkpath;
 198         int pfs_id;
 199         int fd;
 200         int error;
 201
 202         if (ac == 0)
 203                 pseudofs_usage(1);
 204         path = av[0];
 205         if (lstat(path, &st) == 0) {
 206                 fprintf(stderr, "Cannot create %s, file exists!\n", path);
 207                 exit(1);
 208         }
 209
 210         dirpath = strdup(path);
 211         if (strrchr(dirpath, '/') != NULL) {
 212                 *strrchr(dirpath, '/') = 0;
 213         } else {
 214                 free(dirpath);
 215                 dirpath = strdup(".");
 216         }
 217         fd = open(dirpath, O_RDONLY);
 218         if (fd < 0) {
 219                 fprintf(stderr, "Cannot open directory %s\n", dirpath);
 220                 exit(1);
 221         }
 222
 223         error = 0;
 224         for (pfs_id = 0; pfs_id < HAMMER_MAX_PFS; ++pfs_id) {
 225                 bzero(&pfs, sizeof(pfs));
 226                 bzero(&pfsd, sizeof(pfsd));
 227                 pfs.pfs_id = pfs_id;
 228                 pfs.ondisk = &pfsd;
 229                 pfs.bytes = sizeof(pfsd);
 230                 pfs.version = HAMMER_IOC_PSEUDOFS_VERSION;
 231                 if (ioctl(fd, HAMMERIOC_GET_PSEUDOFS, &pfs) < 0) {
 232                         error = errno;
 233                         break;
 234                 }
 235         }
 236         if (pfs_id == HAMMER_MAX_PFS) {
 237                 fprintf(stderr, "Cannot create %s, all PFSs in use\n", path);
 238                 exit(1);
 239         }
 240         if (error != ENOENT) {
 241                 fprintf(stderr, "Cannot create %s, got %s during scan\n",
 242                         path, strerror(error));
 243                 exit(1);
 244         }
 245
 246         /*
 247          * Create the new PFS
 248          */
 249         printf("Creating PFS #%d\t", pfs_id);
 250         bzero(&pfsd, sizeof(pfsd));
 251         init_pfsd(&pfsd, is_slave);
 252         pfs.pfs_id = pfs_id;
 253         pfs.ondisk = &pfsd;
 254         pfs.bytes = sizeof(pfsd);
 255         pfs.version = HAMMER_IOC_PSEUDOFS_VERSION;
 256
 257         if (ioctl(fd, HAMMERIOC_SET_PSEUDOFS, &pfs) < 0) {
 258                 printf("failed: %s\n", strerror(errno));
 259         } else {
 260                 /* special symlink, must be exactly 10 characters */
 261                 asprintf(&linkpath, "@@PFS%05d", pfs_id);
 262                 if (symlink(linkpath, path) < 0) {
 263                         printf("failed: cannot create symlink: %s\n",
 264                                 strerror(errno));
 265                 } else {
 266                         printf("succeeded!\n");
 267                         hammer_cmd_pseudofs_update(av, ac);
 268                 }
 269         }
 270         close(fd);
 271 }
 272
 273 void
 274 hammer_cmd_pseudofs_destroy(char **av, int ac)
 275 {
 276         struct hammer_ioc_pseudofs_rw pfs;
 277         struct stat st;
 278         int fd;
 279         int i;
 280
 281         if (ac == 0)
 282                 pseudofs_usage(1);
 283         bzero(&pfs, sizeof(pfs));
 284         fd = getpfs(&pfs, av[0]);
 285
 286         if (pfs.pfs_id == 0) {
 287                 fprintf(stderr, "You cannot destroy PFS#0\n");
 288                 exit(1);
 289         }
 290         printf("You have requested that PFS#%d (%s) be destroyed\n",
 291                 pfs.pfs_id, pfs.ondisk->label);
 292         printf("This will irrevocably destroy all data on this PFS!!!!!\n");
 293         printf("Do you really want to do this? ");
 294         fflush(stdout);
 295         if (getyn() == 0) {
 296                 fprintf(stderr, "No action taken on PFS#%d\n", pfs.pfs_id);
 297                 exit(1);
 298         }
 299
 300         if ((pfs.ondisk->mirror_flags & HAMMER_PFSD_SLAVE) == 0) {
 301                 printf("This PFS is currently setup as a MASTER!\n");
 302                 printf("Are you absolutely sure you want to destroy it? ");
 303                 fflush(stdout);
 304                 if (getyn() == 0) {
 305                         fprintf(stderr, "No action taken on PFS#%d\n",
 306                                 pfs.pfs_id);
 307                         exit(1);
 308                 }
 309         }
 310
 311         printf("Destroying PFS #%d (%s) in ", pfs.pfs_id, pfs.ondisk->label);
 312         for (i = 5; i; --i) {
 313                 printf(" %d", i);
 314                 fflush(stdout);
 315                 sleep(1);
 316         }
 317         printf(".. starting destruction pass\n");
 318         fflush(stdout);
 319
 320         /*
 321          * Set the sync_beg_tid and sync_end_tid's to 1, once we start the
 322          * RMR the PFS is basically destroyed even if someone ^C's it.
 323          */
 324         pfs.ondisk->mirror_flags |= HAMMER_PFSD_SLAVE;
 325         pfs.ondisk->reserved01 = -1;
 326         pfs.ondisk->sync_beg_tid = 1;
 327         pfs.ondisk->sync_end_tid = 1;
 328
 329         if (ioctl(fd, HAMMERIOC_SET_PSEUDOFS, &pfs) < 0) {
 330                 fprintf(stderr, "Unable to update the PFS configuration: %s\n",
 331                         strerror(errno));
 332                 exit(1);
 333         }
 334
 335         /*
 336          * Ok, do it.  Remove the softlink on success.
 337          */
 338         if (ioctl(fd, HAMMERIOC_RMR_PSEUDOFS, &pfs) == 0) {
 339                 printf("pfs-destroy of PFS#%d succeeded!\n", pfs.pfs_id);
 340                 if (lstat(av[0], &st) == 0 && S_ISLNK(st.st_mode)) {
 341                         if (remove(av[0]) < 0) {
 342                                 fprintf(stderr, "Unable to remove softlink: %s "
 343                                         "(but the PFS has been destroyed)\n",
 344                                         av[0]);
 345                                 /* exit status 0 anyway */
 346                         }
 347                 }
 348         } else {
 349                 printf("pfs-destroy of PFS#%d failed: %s\n",
 350                         pfs.pfs_id, strerror(errno));
 351         }
 352 }
 353
 354 void
 355 hammer_cmd_pseudofs_upgrade(char **av, int ac)
 356 {
 357         struct hammer_ioc_pseudofs_rw pfs;
 358         int fd;
 359
 360         if (ac == 0)
 361                 pseudofs_usage(1);
 362         bzero(&pfs, sizeof(pfs));
 363         fd = getpfs(&pfs, av[0]);
 364
 365         if (pfs.pfs_id == 0) {
 366                 fprintf(stderr, "You cannot upgrade PFS#0"
 367                                 " (It should already be a master)\n");
 368                 exit(1);
 369         }
 370         if (ioctl(fd, HAMMERIOC_UPG_PSEUDOFS, &pfs) == 0) {
 371                 printf("pfs-upgrade of PFS#%d (%s) succeeded\n",
 372                         pfs.pfs_id, pfs.ondisk->label);
 373         } else {
 374                 fprintf(stderr, "pfs-upgrade of PFS#%d (%s) failed: %s\n",
 375                         pfs.pfs_id, pfs.ondisk->label, strerror(errno));
 376         }
 377 }
 378
 379 void
 380 hammer_cmd_pseudofs_downgrade(char **av, int ac)
 381 {
 382         struct hammer_ioc_pseudofs_rw pfs;
 383         int fd;
 384
 385         if (ac == 0)
 386                 pseudofs_usage(1);
 387         bzero(&pfs, sizeof(pfs));
 388         fd = getpfs(&pfs, av[0]);
 389
 390         if (pfs.pfs_id == 0) {
 391                 fprintf(stderr, "You cannot downgrade PFS#0\n");
 392                 exit(1);
 393         }
 394
 395         if (ioctl(fd, HAMMERIOC_DGD_PSEUDOFS, &pfs) == 0) {
 396                 printf("pfs-downgrade of PFS#%d (%s) succeeded\n",
 397                         pfs.pfs_id, pfs.ondisk->label);
 398         } else {
 399                 fprintf(stderr, "pfs-upgrade of PFS#%d (%s) failed: %s\n",
 400                         pfs.pfs_id, pfs.ondisk->label, strerror(errno));
 401         }
 402 }
 403
 404 void
 405 hammer_cmd_pseudofs_update(char **av, int ac)
 406 {
 407         struct hammer_ioc_pseudofs_rw pfs;
 408         int fd;
 409
 410         if (ac == 0)
 411                 pseudofs_usage(1);
 412         bzero(&pfs, sizeof(pfs));
 413         fd = getpfs(&pfs, av[0]);
 414
 415         printf("%s\n", av[0]);
 416         fflush(stdout);
 417
 418         if (ioctl(fd, HAMMERIOC_GET_PSEUDOFS, &pfs) == 0) {
 419                 parse_pfsd_options(av + 1, ac - 1, pfs.ondisk);
 420                 if ((pfs.ondisk->mirror_flags & HAMMER_PFSD_SLAVE) &&
 421                     pfs.pfs_id == 0) {
 422                         printf("The real mount point cannot be made a PFS "
 423                                "slave, only PFS sub-directories can be made "
 424                                "slaves\n");
 425                         exit(1);
 426                 }
 427                 pfs.bytes = sizeof(*pfs.ondisk);
 428                 if (ioctl(fd, HAMMERIOC_SET_PSEUDOFS, &pfs) == 0) {
 429                         if (ioctl(fd, HAMMERIOC_GET_PSEUDOFS, &pfs) == 0) {
 430                                 dump_pfsd(pfs.ondisk);
 431                         } else {
 432                                 printf("Unable to retrieve pfs configuration "
 433                                         "after successful update: %s\n",
 434                                         strerror(errno));
 435                                 exit(1);
 436                         }
 437                 } else {
 438                         printf("Unable to adjust pfs configuration: %s\n",
 439                                 strerror(errno));
 440                         exit(1);
 441                 }
 442         }
 443 }
 444
 445 static void
 446 init_pfsd(hammer_pseudofs_data_t pfsd, int is_slave)
 447 {
 448         uint32_t status;
 449
 450         pfsd->sync_beg_tid = 1;
 451         pfsd->sync_end_tid = 1;
 452         pfsd->sync_beg_ts = 0;
 453         pfsd->sync_end_ts = 0;
 454         uuid_create(&pfsd->shared_uuid, &status);
 455         uuid_create(&pfsd->unique_uuid, &status);
 456         if (is_slave)
 457                 pfsd->mirror_flags |= HAMMER_PFSD_SLAVE;
 458 }
 459
 460 static
 461 void
 462 dump_pfsd(hammer_pseudofs_data_t pfsd)
 463 {
 464         u_int32_t status;
 465         char *str = NULL;
 466
 467         printf("    sync-beg-tid=0x%016llx\n", pfsd->sync_beg_tid);
 468         printf("    sync-end-tid=0x%016llx\n", pfsd->sync_end_tid);
 469         uuid_to_string(&pfsd->shared_uuid, &str, &status);
 470         printf("    shared-uuid=%s\n", str);
 471         uuid_to_string(&pfsd->unique_uuid, &str, &status);
 472         printf("    unique-uuid=%s\n", str);
 473         if (pfsd->mirror_flags & HAMMER_PFSD_SLAVE) {
 474                 printf("    slave\n");
 475         }
 476         printf("    label=\"%s\"\n", pfsd->label);
 477         if (pfsd->snapshots[0])
 478                 printf("    snapshots=\"%s\"\n", pfsd->snapshots);
 479         if (pfsd->mirror_flags & HAMMER_PFSD_SLAVE) {
 480                 printf("    operating as a SLAVE\n");
 481                 if (pfsd->snapshots[0] == 0)
 482                         printf("    snapshots directory not set for slave\n");
 483         } else {
 484                 printf("    operating as a MASTER\n");
 485                 if (pfsd->snapshots[0] == 0) {
 486                         printf("    snapshots dir for master "
 487                                "defaults to <fs>/snapshots\n");
 488                 }
 489         }
 490 }
 491
 492 static void
 493 parse_pfsd_options(char **av, int ac, hammer_pseudofs_data_t pfsd)
 494 {
 495         char *cmd;
 496         char *ptr;
 497         int len;
 498         uint32_t status;
 499
 500         while (ac) {
 501                 cmd = *av;
 502                 if ((ptr = strchr(cmd, '=')) != NULL)
 503                         *ptr++ = 0;
 504
 505                 /*
 506                  * Basic assignment value test
 507                  */
 508                 if (ptr == NULL) {
 509                         fprintf(stderr,
 510                                 "option %s requires an assignment\n",
 511                                 cmd);
 512                         exit(1);
 513                 }
 514
 515                 status = uuid_s_ok;
 516                 if (strcmp(cmd, "sync-beg-tid") == 0) {
 517                         pfsd->sync_beg_tid = strtoull(ptr, NULL, 16);
 518                 } else if (strcmp(cmd, "sync-end-tid") == 0) {
 519                         pfsd->sync_end_tid = strtoull(ptr, NULL, 16);
 520                 } else if (strcmp(cmd, "shared-uuid") == 0) {
 521                         uuid_from_string(ptr, &pfsd->shared_uuid, &status);
 522                 } else if (strcmp(cmd, "unique-uuid") == 0) {
 523                         uuid_from_string(ptr, &pfsd->unique_uuid, &status);
 524                 } else if (strcmp(cmd, "label") == 0) {
 525                         len = strlen(ptr);
 526                         if (ptr[0] == '"' && ptr[len-1] == '"') {
 527                                 ptr[len-1] = 0;
 528                                 ++ptr;
 529                         } else if (ptr[0] == '"') {
 530                                 fprintf(stderr,
 531                                         "option %s: malformed string\n",
 532                                         cmd);
 533                                 exit(1);
 534                         }
 535                         snprintf(pfsd->label, sizeof(pfsd->label), "%s", ptr);
 536                 } else if (strcmp(cmd, "snapshots") == 0) {
 537                         len = strlen(ptr);
 538                         if (ptr[0] != '/') {
 539                                 fprintf(stderr,
 540                                         "option %s: '%s' must be an "
 541                                         "absolute path\n", cmd, ptr);
 542                                 if (ptr[0] == 0) {
 543                                         fprintf(stderr,
 544                                                 "use 'snapshots-clear' "
 545                                                 "to unset snapshots dir\n");
 546                                 }
 547                                 exit(1);
 548                         }
 549                         if (len >= (int)sizeof(pfsd->snapshots)) {
 550                                 fprintf(stderr,
 551                                         "option %s: path too long, %d "
 552                                         "character limit\n", cmd, len);
 553                                 exit(1);
 554                         }
 555                         snprintf(pfsd->snapshots, sizeof(pfsd->snapshots),
 556                                  "%s", ptr);
 557                 } else if (strcmp(cmd, "snapshots-clear") == 0) {
 558                         pfsd->snapshots[0] = 0;
 559                 } else {
 560                         fprintf(stderr, "invalid option: %s\n", cmd);
 561                         exit(1);
 562                 }
 563                 if (status != uuid_s_ok) {
 564                         fprintf(stderr, "option %s: error parsing uuid %s\n",
 565                                 cmd, ptr);
 566                         exit(1);
 567                 }
 568                 --ac;
 569                 ++av;
 570         }
 571 }
 572
 573 static
 574 void
 575 pseudofs_usage(int code)
 576 {
 577         fprintf(stderr,
 578                 "hammer pfs-status <dirpath> ...\n"
 579                 "hammer pfs-master <dirpath> [options]\n"
 580                 "hammer pfs-slave <dirpath> [options]\n"
 581                 "hammer pfs-update <dirpath> [options]\n"
 582                 "hammer pfs-upgrade <dirpath>\n"
 583                 "hammer pfs-downgrade <dirpath>\n"
 584                 "hammer pfs-destroy <dirpath>\n"
 585                 "\n"
 586                 "options:\n"
 587                 "    sync-beg-tid=0x16llx\n"
 588                 "    sync-end-tid=0x16llx\n"
 589                 "    shared-uuid=0x16llx\n"
 590                 "    unique-uuid=0x16llx\n"
 591                 "    label=\"string\"\n"
 592                 "    snapshots=\"/path\"\n"
 593                 "    snapshots-clear\n"
 594         );
 595         exit(code);
 596 }
 597
 598 static
 599 int
 600 getyn(void)
 601 {
 602         char buf[256];
 603         int len;
 604
 605         if (fgets(buf, sizeof(buf), stdin) == NULL)
 606                 return(0);
 607         len = strlen(buf);
 608         while (len && (buf[len-1] == '\n' || buf[len-1] == '\r'))
 609                 --len;
 610         buf[len] = 0;
 611         if (strcmp(buf, "y") == 0 ||
 612             strcmp(buf, "yes") == 0 ||
 613             strcmp(buf, "Y") == 0 ||
 614             strcmp(buf, "YES") == 0) {
 615                 return(1);
 616         }
 617         return(0);
 618 }
 619