support/nfs/exports.c

   1 /*
   2  * support/nfs/export.c
   3  *
   4  * Parse the exports file. Derived from the unfsd implementation.
   5  *
   6  * Authors:     Donald J. Becker, <becker@super.org>
   7  *              Rick Sladkey, <jrs@world.std.com>
   8  *              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
   9  *              Olaf Kirch, <okir@monad.swb.de>
  10  *              Alexander O. Yuriev, <alex@bach.cis.temple.edu>
  11  *
  12  *              This software maybe be used for any purpose provided
  13  *              the above copyright notice is retained.  It is supplied
  14  *              as is, with no warranty expressed or implied.
  15  */
  16
  17 #include "config.h"
  18
  19 #include <sys/param.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <stdio.h>
  23 #include <ctype.h>
  24 #include <unistd.h>
  25 #include <errno.h>
  26 #include "nfslib.h"
  27 #include "exportfs.h"
  28 #include "xmalloc.h"
  29 #include "xlog.h"
  30 #include "xio.h"
  31
  32 #define EXPORT_DEFAULT_FLAGS    \
  33   (NFSEXP_READONLY|NFSEXP_ROOTSQUASH|NFSEXP_GATHERED_WRITES)
  34
  35 int export_errno;
  36
  37 static char     *efname = NULL;
  38 static XFILE    *efp = NULL;
  39 static int      first;
  40 static int      *squids = NULL, nsquids = 0,
  41                 *sqgids = NULL, nsqgids = 0;
  42
  43 static int      getexport(char *exp, int len);
  44 static int      getpath(char *path, int len);
  45 static int      parseopts(char *cp, struct exportent *ep, int warn);
  46 static int      parsesquash(char *list, int **idp, int *lenp, char **ep);
  47 static int      parsenum(char **cpp);
  48 static int      parsemaptype(char *type);
  49 static void     freesquash(void);
  50 static void     syntaxerr(char *msg);
  51
  52 void
  53 setexportent(char *fname, char *type)
  54 {
  55         if (efp)
  56                 endexportent();
  57         if (!fname)
  58                 fname = _PATH_EXPORTS;
  59         if (!(efp = xfopen(fname, type)))
  60                 xlog(L_ERROR, "can't open %s for %sing",
  61                                 fname, strcmp(type, "r")? "writ" : "read");
  62         efname = strdup(fname);
  63         first = 1;
  64 }
  65
  66 struct exportent *
  67 getexportent(int fromkernel, int fromexports)
  68 {
  69         static struct exportent ee;
  70         char            exp[512];
  71         char            rpath[MAXPATHLEN+1];
  72         char            *opt, *sp;
  73         int             ok;
  74
  75         if (!efp)
  76                 return NULL;
  77
  78         freesquash();
  79         ee.e_flags = EXPORT_DEFAULT_FLAGS;
  80         /* some kernels assume the default is sync rather than
  81          * async.  More recent kernels always report one or other,
  82          * but this test makes sure we assume same as kernel
  83          * Ditto for wgather
  84          */
  85         if (fromkernel) {
  86                 ee.e_flags &= ~NFSEXP_ASYNC;
  87                 ee.e_flags &= ~NFSEXP_GATHERED_WRITES;
  88         }
  89         ee.e_maptype = CLE_MAP_IDENT;
  90         ee.e_anonuid = -2;
  91         ee.e_anongid = -2;
  92         ee.e_squids = NULL;
  93         ee.e_sqgids = NULL;
  94         ee.e_mountpoint = NULL;
  95         ee.e_nsquids = 0;
  96         ee.e_nsqgids = 0;
  97
  98         if (first || (ok = getexport(exp, sizeof(exp))) == 0) {
  99                 ok = getpath(ee.e_path, sizeof(ee.e_path));
 100                 if (ok <= 0)
 101                         return NULL;
 102                 strncpy (ee.m_path, ee.e_path, sizeof (ee.m_path) - 1);
 103                 ee.m_path [sizeof (ee.m_path) - 1] = '\0';
 104                 ok = getexport(exp, sizeof(exp));
 105         }
 106         if (ok < 0) {
 107                 xlog(L_ERROR, "expected client(options...)");
 108                 export_errno = EINVAL;
 109                 return NULL;
 110         }
 111         first = 0;
 112
 113         /* Check for default client */
 114         if (ok == 0)
 115                 exp[0] = '\0';
 116         if ((opt = strchr(exp, '(')) != NULL) {
 117                 if (opt == exp)
 118                         xlog(L_WARNING, "No host name given with %s %s, suggest *%s to avoid warning", ee.e_path, exp, exp);
 119                 *opt++ = '\0';
 120                 if (!(sp = strchr(opt, ')')) || sp[1] != '\0') {
 121                         syntaxerr("bad option list");
 122                         export_errno = EINVAL;
 123                         return NULL;
 124                 }
 125                 *sp = '\0';
 126         } else {
 127             xlog(L_WARNING, "No options for %s %s: suggest %s(sync) to avoid warning", ee.e_path, exp, exp);
 128         }
 129         if (strlen(exp) >= sizeof(ee.e_hostname)) {
 130                 syntaxerr("client name too long");
 131                 export_errno = EINVAL;
 132                 return NULL;
 133         }
 134         strncpy(ee.e_hostname, exp, sizeof (ee.e_hostname) - 1);
 135         ee.e_hostname[sizeof (ee.e_hostname) - 1] = '\0';
 136
 137         if (parseopts(opt, &ee, fromexports) < 0)
 138                 return NULL;
 139
 140         /* resolve symlinks */
 141         if (realpath(ee.e_path, rpath) != NULL) {
 142                 rpath[sizeof (rpath) - 1] = '\0';
 143                 strncpy(ee.e_path, rpath, sizeof (ee.e_path) - 1);
 144                 ee.e_path[sizeof (ee.e_path) - 1] = '\0';
 145                 strncpy (ee.m_path, ee.e_path, sizeof (ee.m_path) - 1);
 146                 ee.m_path [sizeof (ee.m_path) - 1] = '\0';
 147         }
 148
 149         return &ee;
 150 }
 151
 152 void
 153 putexportent(struct exportent *ep)
 154 {
 155         FILE    *fp;
 156         int     *id, i;
 157         char    *esc=ep->e_path;
 158
 159         if (!efp)
 160                 return;
 161
 162         fp = efp->x_fp;
 163         for (i=0; esc[i]; i++)
 164                 if (iscntrl(esc[i]) || esc[i] == '"' || esc[i] == '\\'|| isspace(esc[i]))
 165                         fprintf(fp, "\\%03o", esc[i]);
 166                 else
 167                         fprintf(fp, "%c", esc[i]);
 168
 169         fprintf(fp, "\t%s(", ep->e_hostname);
 170         fprintf(fp, "%s,", (ep->e_flags & NFSEXP_READONLY)? "ro" : "rw");
 171         fprintf(fp, "%ssync,", (ep->e_flags & NFSEXP_ASYNC)? "a" : "");
 172         fprintf(fp, "%swdelay,", (ep->e_flags & NFSEXP_GATHERED_WRITES)?
 173                                 "" : "no_");
 174         fprintf(fp, "%shide,", (ep->e_flags & NFSEXP_NOHIDE)?
 175                                 "no" : "");
 176         fprintf(fp, "%scrossmnt,", (ep->e_flags & NFSEXP_CROSSMOUNT)?
 177                                 "" : "no");
 178         fprintf(fp, "%ssecure,", (ep->e_flags & NFSEXP_INSECURE_PORT)?
 179                                 "in" : "");
 180         fprintf(fp, "%sroot_squash,", (ep->e_flags & NFSEXP_ROOTSQUASH)?
 181                                 "" : "no_");
 182         fprintf(fp, "%sall_squash,", (ep->e_flags & NFSEXP_ALLSQUASH)?
 183                                 "" : "no_");
 184         fprintf(fp, "%ssubtree_check,", (ep->e_flags & NFSEXP_NOSUBTREECHECK)?
 185                 "no_" : "");
 186         fprintf(fp, "%ssecure_locks,", (ep->e_flags & NFSEXP_NOAUTHNLM)?
 187                 "in" : "");
 188         fprintf(fp, "%sacl,", (ep->e_flags & NFSEXP_NOACL)?
 189                 "no_" : "");
 190         if (ep->e_flags & NFSEXP_FSID) {
 191                 fprintf(fp, "fsid=%d,", ep->e_fsid);
 192         }
 193         if (ep->e_mountpoint)
 194                 fprintf(fp, "mountpoint%s%s,",
 195                         ep->e_mountpoint[0]?"=":"", ep->e_mountpoint);
 196
 197         fprintf(fp, "mapping=");
 198         switch (ep->e_maptype) {
 199         case CLE_MAP_IDENT:
 200                 fprintf(fp, "identity,");
 201                 break;
 202         case CLE_MAP_UGIDD:
 203                 fprintf(fp, "ugidd,");
 204                 break;
 205         case CLE_MAP_FILE:
 206                 fprintf(fp, "file,");
 207                 break;
 208         default:
 209                 xlog(L_ERROR, "unknown mapping type for %s:%s",
 210                                         ep->e_hostname, ep->e_path);
 211         }
 212         if ((id = ep->e_squids) != NULL) {
 213                 fprintf(fp, "squash_uids=");
 214                 for (i = 0; i < ep->e_nsquids; i += 2)
 215                         if (id[i] != id[i+1])
 216                                 fprintf(fp, "%d-%d,", id[i], id[i+1]);
 217                         else
 218                                 fprintf(fp, "%d,", id[i]);
 219         }
 220         if ((id = ep->e_sqgids) != NULL) {
 221                 fprintf(fp, "squash_gids=");
 222                 for (i = 0; i < ep->e_nsquids; i += 2)
 223                         if (id[i] != id[i+1])
 224                                 fprintf(fp, "%d-%d,", id[i], id[i+1]);
 225                         else
 226                                 fprintf(fp, "%d,", id[i]);
 227         }
 228         fprintf(fp, "anonuid=%d,anongid=%d)\n", ep->e_anonuid, ep->e_anongid);
 229 }
 230
 231 void
 232 endexportent(void)
 233 {
 234         if (efp)
 235                 xfclose(efp);
 236         efp = NULL;
 237         if (efname)
 238                 free(efname);
 239         efname = NULL;
 240         freesquash();
 241 }
 242
 243 void
 244 dupexportent(struct exportent *dst, struct exportent *src)
 245 {
 246         int     n;
 247
 248         *dst = *src;
 249         if ((n = src->e_nsquids) != 0) {
 250                 dst->e_squids = (int *) xmalloc(n * sizeof(int));
 251                 memcpy(dst->e_squids, src->e_squids, n * sizeof(int));
 252         }
 253         if ((n = src->e_nsqgids) != 0) {
 254                 dst->e_sqgids = (int *) xmalloc(n * sizeof(int));
 255                 memcpy(dst->e_sqgids, src->e_sqgids, n * sizeof(int));
 256         }
 257         if (src->e_mountpoint)
 258                 dst->e_mountpoint = strdup(src->e_mountpoint);
 259 }
 260
 261 struct exportent *
 262 mkexportent(char *hname, char *path, char *options)
 263 {
 264         static struct exportent ee;
 265
 266         ee.e_flags = EXPORT_DEFAULT_FLAGS;
 267         ee.e_maptype = CLE_MAP_IDENT;
 268         ee.e_anonuid = -2;
 269         ee.e_anongid = -2;
 270         ee.e_squids = NULL;
 271         ee.e_sqgids = NULL;
 272         ee.e_mountpoint = NULL;
 273         ee.e_nsquids = 0;
 274         ee.e_nsqgids = 0;
 275
 276         if (strlen(hname) >= sizeof(ee.e_hostname)) {
 277                 xlog(L_WARNING, "client name %s too long", hname);
 278                 return NULL;
 279         }
 280         strncpy(ee.e_hostname, hname, sizeof (ee.e_hostname) - 1);
 281         ee.e_hostname[sizeof (ee.e_hostname) - 1] = '\0';
 282         if (strlen(path) >= sizeof(ee.e_path)) {
 283                 xlog(L_WARNING, "path name %s too long", path);
 284                 return NULL;
 285         }
 286         strncpy(ee.e_path, path, sizeof (ee.e_path));
 287         ee.e_path[sizeof (ee.e_path) - 1] = '\0';
 288         strncpy (ee.m_path, ee.e_path, sizeof (ee.m_path) - 1);
 289         ee.m_path [sizeof (ee.m_path) - 1] = '\0';
 290         if (parseopts(options, &ee, 0) < 0)
 291                 return NULL;
 292         return &ee;
 293 }
 294
 295 int
 296 updateexportent(struct exportent *eep, char *options)
 297 {
 298         if (parseopts(options, eep, 0) < 0)
 299                 return 0;
 300         return 1;
 301 }
 302
 303 /*
 304  * Parse option string pointed to by cp and set mount options accordingly.
 305  */
 306 static int
 307 parseopts(char *cp, struct exportent *ep, int warn)
 308 {
 309         int     had_sync_opt = 0;
 310         char    *flname = efname?efname:"command line";
 311         int     flline = efp?efp->x_line:0;
 312
 313         squids = ep->e_squids; nsquids = ep->e_nsquids;
 314         sqgids = ep->e_sqgids; nsqgids = ep->e_nsqgids;
 315
 316         if (!cp)
 317                 goto out;
 318
 319         while (isblank(*cp))
 320                 cp++;
 321
 322         while (*cp) {
 323                 char *opt = strdup(cp);
 324                 char *optstart = cp;
 325                 while (*cp && *cp != ',')
 326                         cp++;
 327                 if (*cp) {
 328                         opt[cp-optstart] = '\0';
 329                         cp++;
 330                 }
 331
 332                 /* process keyword */
 333                 if (strcmp(opt, "ro") == 0)
 334                         ep->e_flags |= NFSEXP_READONLY;
 335                 else if (strcmp(opt, "rw") == 0)
 336                         ep->e_flags &= ~NFSEXP_READONLY;
 337                 else if (!strcmp(opt, "secure"))
 338                         ep->e_flags &= ~NFSEXP_INSECURE_PORT;
 339                 else if (!strcmp(opt, "insecure"))
 340                         ep->e_flags |= NFSEXP_INSECURE_PORT;
 341                 else if (!strcmp(opt, "sync")) {
 342                         had_sync_opt = 1;
 343                         ep->e_flags &= ~NFSEXP_ASYNC;
 344                 } else if (!strcmp(opt, "async")) {
 345                         had_sync_opt = 1;
 346                         ep->e_flags |= NFSEXP_ASYNC;
 347                 } else if (!strcmp(opt, "nohide"))
 348                         ep->e_flags |= NFSEXP_NOHIDE;
 349                 else if (!strcmp(opt, "hide"))
 350                         ep->e_flags &= ~NFSEXP_NOHIDE;
 351                 else if (!strcmp(opt, "crossmnt"))
 352                         ep->e_flags |= NFSEXP_CROSSMOUNT;
 353                 else if (!strcmp(opt, "nocrossmnt"))
 354                         ep->e_flags &= ~NFSEXP_CROSSMOUNT;
 355                 else if (!strcmp(opt, "wdelay"))
 356                         ep->e_flags |= NFSEXP_GATHERED_WRITES;
 357                 else if (!strcmp(opt, "no_wdelay"))
 358                         ep->e_flags &= ~NFSEXP_GATHERED_WRITES;
 359                 else if (strcmp(opt, "root_squash") == 0)
 360                         ep->e_flags |= NFSEXP_ROOTSQUASH;
 361                 else if (!strcmp(opt, "no_root_squash"))
 362                         ep->e_flags &= ~NFSEXP_ROOTSQUASH;
 363                 else if (strcmp(opt, "all_squash") == 0)
 364                         ep->e_flags |= NFSEXP_ALLSQUASH;
 365                 else if (strcmp(opt, "no_all_squash") == 0)
 366                         ep->e_flags &= ~NFSEXP_ALLSQUASH;
 367                 else if (strcmp(opt, "subtree_check") == 0)
 368                         ep->e_flags &= ~NFSEXP_NOSUBTREECHECK;
 369                 else if (strcmp(opt, "no_subtree_check") == 0)
 370                         ep->e_flags |= NFSEXP_NOSUBTREECHECK;
 371                 else if (strcmp(opt, "auth_nlm") == 0)
 372                         ep->e_flags &= ~NFSEXP_NOAUTHNLM;
 373                 else if (strcmp(opt, "no_auth_nlm") == 0)
 374                         ep->e_flags |= NFSEXP_NOAUTHNLM;
 375                 else if (strcmp(opt, "secure_locks") == 0)
 376                         ep->e_flags &= ~NFSEXP_NOAUTHNLM;
 377                 else if (strcmp(opt, "insecure_locks") == 0)
 378                         ep->e_flags |= NFSEXP_NOAUTHNLM;
 379                 else if (strcmp(opt, "acl") == 0)
 380                         ep->e_flags &= ~NFSEXP_NOACL;
 381                 else if (strcmp(opt, "no_acl") == 0)
 382                         ep->e_flags |= NFSEXP_NOACL;
 383                 else if (strncmp(opt, "mapping=", 8) == 0)
 384                         ep->e_maptype = parsemaptype(opt+8);
 385                 else if (strcmp(opt, "map_identity") == 0)      /* old style */
 386                         ep->e_maptype = CLE_MAP_IDENT;
 387                 else if (strcmp(opt, "map_daemon") == 0)        /* old style */
 388                         ep->e_maptype = CLE_MAP_UGIDD;
 389                 else if (strncmp(opt, "anonuid=", 8) == 0) {
 390                         char *oe;
 391                         ep->e_anonuid = strtol(opt+8, &oe, 10);
 392                         if (opt[8]=='\0' || *oe != '\0') {
 393                                 xlog(L_ERROR, "%s: %d: bad anonuid \"%s\"\n",
 394                                      flname, flline, opt);
 395 bad_option:
 396                                 free(opt);
 397                                 export_errno = EINVAL;
 398                                 return -1;
 399                         }
 400                 } else if (strncmp(opt, "anongid=", 8) == 0) {
 401                         char *oe;
 402                         ep->e_anongid = strtol(opt+8, &oe, 10);
 403                         if (opt[8]=='\0' || *oe != '\0') {
 404                                 xlog(L_ERROR, "%s: %d: bad anongid \"%s\"\n",
 405                                      flname, flline, opt);
 406                                 goto bad_option;
 407                         }
 408                 } else if (strncmp(opt, "squash_uids=", 12) == 0) {
 409                         if (parsesquash(opt+12, &squids, &nsquids, &cp) < 0) {
 410                                 goto bad_option;
 411                         }
 412                 } else if (strncmp(opt, "squash_gids=", 12) == 0) {
 413                         if (parsesquash(opt+12, &sqgids, &nsqgids, &cp) < 0) {
 414                                 goto bad_option;
 415                         }
 416                 } else if (strncmp(opt, "fsid=", 5) == 0) {
 417                         char *oe;
 418                         ep->e_fsid = strtoul(opt+5, &oe, 0);
 419                         if (opt[5]=='\0' || *oe != '\0') {
 420                                 xlog(L_ERROR, "%s: %d: bad fsid \"%s\"\n",
 421                                      flname, flline, opt);
 422                                 goto bad_option;
 423                         }
 424                         ep->e_flags |= NFSEXP_FSID;
 425                 } else if (strcmp(opt, "mountpoint")==0 ||
 426                            strcmp(opt, "mp") == 0 ||
 427                            strncmp(opt, "mountpoint=", 11)==0 ||
 428                            strncmp(opt, "mp=", 3) == 0) {
 429                         char * mp = strchr(opt, '=');
 430                         if (mp)
 431                                 ep->e_mountpoint = strdup(mp+1);
 432                         else
 433                                 ep->e_mountpoint = strdup("");
 434                 } else {
 435                         xlog(L_ERROR, "%s:%d: unknown keyword \"%s\"\n",
 436                                         flname, flline, opt);
 437                         ep->e_flags |= NFSEXP_ALLSQUASH | NFSEXP_READONLY;
 438                         goto bad_option;
 439                 }
 440                 free(opt);
 441                 while (isblank(*cp))
 442                         cp++;
 443         }
 444
 445         ep->e_squids = squids;
 446         ep->e_sqgids = sqgids;
 447         ep->e_nsquids = nsquids;
 448         ep->e_nsqgids = nsqgids;
 449
 450 out:
 451         if (warn && !had_sync_opt)
 452                 xlog(L_WARNING, "%s [%d]: No 'sync' or 'async' option specified for export \"%s:%s\".\n"
 453                                 "  Assuming default behaviour ('sync').\n"
 454                                 "  NOTE: this default has changed from previous versions\n",
 455
 456                                 flname, flline,
 457                                 ep->e_hostname, ep->e_path);
 458
 459         return 1;
 460 }
 461
 462 static int
 463 parsesquash(char *list, int **idp, int *lenp, char **ep)
 464 {
 465         char    *cp = list;
 466         int     id0, id1;
 467         int     len = *lenp;
 468         int     *id = *idp;
 469
 470         if (**ep)
 471             *--(*ep) = ',';
 472
 473         do {
 474                 id0 = parsenum(&cp);
 475                 if (*cp == '-') {
 476                         cp++;
 477                         id1 = parsenum(&cp);
 478                 } else {
 479                         id1 = id0;
 480                 }
 481                 if (id0 == -1 || id1 == -1) {
 482                         syntaxerr("uid/gid -1 not permitted");
 483                         return -1;
 484                 }
 485                 if ((len % 8) == 0)
 486                         id = (int *) xrealloc(id, (len + 8) * sizeof(*id));
 487                 id[len++] = id0;
 488                 id[len++] = id1;
 489                 if (!*cp || *cp == ')' || (*cp == ',' && !isdigit(cp[1])))
 490                         break;
 491                 if (*cp != ',') {
 492                         syntaxerr("bad uid/gid list");
 493                         return -1;
 494                 }
 495                 cp++;
 496         } while(1);
 497
 498         if (**ep == ',') (*ep)++;
 499
 500         *lenp = len;
 501         *idp = id;
 502         return 1;
 503 }
 504
 505 static void
 506 freesquash(void)
 507 {
 508         if (squids) {
 509                 xfree (squids);
 510                 squids = NULL;
 511                 nsquids = 0;
 512         }
 513         if (sqgids) {
 514                 xfree (sqgids);
 515                 sqgids = NULL;
 516                 nsqgids = 0;
 517         }
 518 }
 519
 520 static int
 521 parsenum(char **cpp)
 522 {
 523         char    *cp = *cpp, c;
 524         int     num = 0;
 525
 526         if (**cpp == '-')
 527                 (*cpp)++;
 528         while (isdigit(**cpp))
 529                 (*cpp)++;
 530         c = **cpp; **cpp = '\0'; num = atoi(cp); **cpp = c;
 531         return num;
 532 }
 533
 534 static int
 535 parsemaptype(char *type)
 536 {
 537         if (!strcmp(type, "identity"))
 538                 return CLE_MAP_IDENT;
 539         if (!strcmp(type, "ugidd"))
 540                 return CLE_MAP_UGIDD;
 541         if (!strcmp(type, "file"))
 542                 return CLE_MAP_FILE;
 543         syntaxerr("invalid map type");
 544         return CLE_MAP_IDENT;   /* default */
 545 }
 546
 547 static int
 548 getpath(char *path, int len)
 549 {
 550         xskip(efp, " \t\n");
 551         return xgettok(efp, 0, path, len);
 552 }
 553
 554 static int
 555 getexport(char *exp, int len)
 556 {
 557         int     ok;
 558
 559         xskip(efp, " \t");
 560         if ((ok = xgettok(efp, 0, exp, len)) < 0)
 561                 xlog(L_ERROR, "%s:%d: syntax error",
 562                         efname?"command line":efname, efp->x_line);
 563         return ok;
 564 }
 565
 566 static void
 567 syntaxerr(char *msg)
 568 {
 569         xlog(L_ERROR, "%s:%d: syntax error: %s",
 570                         efname, efp?efp->x_line:0, msg);
 571 }
 572