utils/mountd/cache.c

   1
   2 /*
   3  * Handle communication with knfsd internal cache
   4  *
   5  * We open /proc/net/rpc/{auth.unix.ip,nfsd.export,nfsd.fh}/channel
   6  * and listen for requests (using my_svc_run)
   7  *
   8  */
   9
  10 #ifdef HAVE_CONFIG_H
  11 #include <config.h>
  12 #endif
  13
  14 #include <sys/types.h>
  15 #include <sys/select.h>
  16 #include <sys/stat.h>
  17 #include <time.h>
  18 #include <netinet/in.h>
  19 #include <arpa/inet.h>
  20 #include <unistd.h>
  21 #include <fcntl.h>
  22 #include <errno.h>
  23 #include <ctype.h>
  24 #include <pwd.h>
  25 #include <grp.h>
  26 #include <mntent.h>
  27 #include "misc.h"
  28 #include "nfslib.h"
  29 #include "exportfs.h"
  30 #include "mountd.h"
  31 #include "xmalloc.h"
  32 #include "fsloc.h"
  33
  34 #include "blkid/blkid.h"
  35
  36
  37 enum nfsd_fsid {
  38         FSID_DEV = 0,
  39         FSID_NUM,
  40         FSID_MAJOR_MINOR,
  41         FSID_ENCODE_DEV,
  42         FSID_UUID4_INUM,
  43         FSID_UUID8,
  44         FSID_UUID16,
  45         FSID_UUID16_INUM,
  46 };
  47
  48 /*
  49  * Support routines for text-based upcalls.
  50  * Fields are separated by spaces.
  51  * Fields are either mangled to quote space tab newline slosh with slosh
  52  * or a hexified with a leading \x
  53  * Record is terminated with newline.
  54  *
  55  */
  56 int cache_export_ent(char *domain, struct exportent *exp, char *p);
  57
  58
  59 char *lbuf  = NULL;
  60 int lbuflen = 0;
  61
  62 void auth_unix_ip(FILE *f)
  63 {
  64         /* requests are
  65          *  class IP-ADDR
  66          * Ignore if class != "nfsd"
  67          * Otherwise find domainname and write back:
  68          *
  69          *  "nfsd" IP-ADDR expiry domainname
  70          */
  71         char *cp;
  72         char class[20];
  73         char ipaddr[20];
  74         char *client;
  75         struct in_addr addr;
  76         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
  77                 return;
  78
  79         cp = lbuf;
  80
  81         if (qword_get(&cp, class, 20) <= 0 ||
  82             strcmp(class, "nfsd") != 0)
  83                 return;
  84
  85         if (qword_get(&cp, ipaddr, 20) <= 0)
  86                 return;
  87
  88         if (inet_aton(ipaddr, &addr)==0)
  89                 return;
  90
  91         auth_reload();
  92
  93         /* addr is a valid, interesting address, find the domain name... */
  94         client = client_compose(addr);
  95
  96
  97         qword_print(f, "nfsd");
  98         qword_print(f, ipaddr);
  99         qword_printint(f, time(0)+30*60);
 100         if (client)
 101                 qword_print(f, *client?client:"DEFAULT");
 102         qword_eol(f);
 103
 104         if (client) free(client);
 105
 106 }
 107
 108 void auth_unix_gid(FILE *f)
 109 {
 110         /* Request are
 111          *  uid
 112          * reply is
 113          *  uid expiry count list of group ids
 114          */
 115         int uid;
 116         struct passwd *pw;
 117         gid_t glist[100], *groups = glist;
 118         int ngroups = 100;
 119         int rv, i;
 120         char *cp;
 121
 122         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
 123                 return;
 124
 125         cp = lbuf;
 126         if (qword_get_int(&cp, &uid) != 0)
 127                 return;
 128
 129         pw = getpwuid(uid);
 130         if (!pw)
 131                 rv = -1;
 132         else {
 133                 rv = getgrouplist(pw->pw_name, pw->pw_gid, groups, &ngroups);
 134                 if (rv == -1 && ngroups >= 100) {
 135                         groups = malloc(sizeof(gid_t)*ngroups);
 136                         if (!groups)
 137                                 rv = -1;
 138                         else
 139                                 rv = getgrouplist(pw->pw_name, pw->pw_gid,
 140                                                   groups, &ngroups);
 141                 }
 142         }
 143         qword_printint(f, uid);
 144         qword_printint(f, time(0)+30*60);
 145         if (rv >= 0) {
 146                 qword_printint(f, ngroups);
 147                 for (i=0; i<ngroups; i++)
 148                         qword_printint(f, groups[i]);
 149         }
 150         qword_eol(f);
 151         if (groups != glist)
 152                 free(groups);
 153 }
 154
 155 int get_uuid(char *path, char *uuid, int uuidlen, char *u)
 156 {
 157         /* extract hex digits from uuidstr and compose a uuid
 158          * of the given length (max 16), xoring bytes to make
 159          * a smaller uuid.  Then compare with uuid
 160          */
 161         int i = 0;
 162         const char *val;
 163
 164         if (path) {
 165                 static blkid_cache cache = NULL;
 166                 struct stat stb;
 167                 char *devname;
 168                 blkid_tag_iterate iter;
 169                 blkid_dev dev;
 170                 const char *type;
 171                 if (cache == NULL)
 172                         blkid_get_cache(&cache, NULL);
 173
 174                 blkid_probe_all_new(cache);
 175
 176                 if (stat(path, &stb) != 0)
 177                         return 0;
 178                 devname = blkid_devno_to_devname(stb.st_dev);
 179                 if (!devname)
 180                         return 0;
 181                 dev = blkid_get_dev(cache, devname, BLKID_DEV_NORMAL);
 182                 free(devname);
 183                 if (!dev)
 184                         return 0;
 185                 iter = blkid_tag_iterate_begin(dev);
 186                 if (!iter)
 187                         return 0;
 188                 while (blkid_tag_next(iter, &type, &val) == 0)
 189                         if (strcmp(type, "UUID") == 0)
 190                                 break;
 191                 blkid_tag_iterate_end(iter);
 192                 if (!type)
 193                         return 0;
 194         } else {
 195                 val = uuid;
 196         }
 197
 198         memset(u, 0, uuidlen);
 199         for ( ; *val ; val++) {
 200                 char c = *val;
 201                 if (!isxdigit(c))
 202                         continue;
 203                 if (isalpha(c)) {
 204                         if (isupper(c))
 205                                 c = c - 'A' + 10;
 206                         else
 207                                 c = c - 'a' + 10;
 208                 } else
 209                         c = c - '0' + 0;
 210                 if ((i&1) == 0)
 211                         c <<= 4;
 212                 u[i/2] ^= c;
 213                 i++;
 214                 if (i == uuidlen*2)
 215                         i = 0;
 216         }
 217         return 1;
 218 }
 219
 220 /* Iterate through /etc/mtab, finding mountpoints
 221  * at or below a given path
 222  */
 223 static char *next_mnt(void **v, char *p)
 224 {
 225         FILE *f;
 226         struct mntent *me;
 227         int l = strlen(p);
 228         if (*v == NULL) {
 229                 f = setmntent("/etc/mtab", "r");
 230                 *v = f;
 231         } else
 232                 f = *v;
 233         while ((me = getmntent(f)) != NULL &&
 234                (strncmp(me->mnt_dir, p, l) != 0 ||
 235                 me->mnt_dir[l] != '/'))
 236                 ;
 237         if (me == NULL) {
 238                 endmntent(f);
 239                 *v = NULL;
 240                 return NULL;
 241         }
 242         return me->mnt_dir;
 243 }
 244
 245 void nfsd_fh(FILE *f)
 246 {
 247         /* request are:
 248          *  domain fsidtype fsid
 249          * interpret fsid, find export point and options, and write:
 250          *  domain fsidtype fsid expiry path
 251          */
 252         char *cp;
 253         char *dom;
 254         int fsidtype;
 255         int fsidlen;
 256         unsigned int dev, major=0, minor=0;
 257         unsigned int inode=0;
 258         unsigned long long inode64;
 259         unsigned int fsidnum=0;
 260         char fsid[32];
 261         struct exportent *found = NULL;
 262         char *found_path = NULL;
 263         nfs_export *exp;
 264         int i;
 265         int dev_missing = 0;
 266         int uuidlen = 0;
 267         char *fhuuid = NULL;
 268
 269         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
 270                 return;
 271
 272         cp = lbuf;
 273
 274         dom = malloc(strlen(cp));
 275         if (dom == NULL)
 276                 return;
 277         if (qword_get(&cp, dom, strlen(cp)) <= 0)
 278                 goto out;
 279         if (qword_get_int(&cp, &fsidtype) != 0)
 280                 goto out;
 281         if (fsidtype < 0 || fsidtype > 7)
 282                 goto out; /* unknown type */
 283         if ((fsidlen = qword_get(&cp, fsid, 32)) <= 0)
 284                 goto out;
 285         switch(fsidtype) {
 286         case FSID_DEV: /* 4 bytes: 2 major, 2 minor, 4 inode */
 287                 if (fsidlen != 8)
 288                         goto out;
 289                 memcpy(&dev, fsid, 4);
 290                 memcpy(&inode, fsid+4, 4);
 291                 major = ntohl(dev)>>16;
 292                 minor = ntohl(dev) & 0xFFFF;
 293                 break;
 294
 295         case FSID_NUM: /* 4 bytes - fsid */
 296                 if (fsidlen != 4)
 297                         goto out;
 298                 memcpy(&fsidnum, fsid, 4);
 299                 break;
 300
 301         case FSID_MAJOR_MINOR: /* 12 bytes: 4 major, 4 minor, 4 inode
 302                  * This format is never actually used but was
 303                  * an historical accident
 304                  */
 305                 if (fsidlen != 12)
 306                         goto out;
 307                 memcpy(&dev, fsid, 4); major = ntohl(dev);
 308                 memcpy(&dev, fsid+4, 4); minor = ntohl(dev);
 309                 memcpy(&inode, fsid+8, 4);
 310                 break;
 311
 312         case FSID_ENCODE_DEV: /* 8 bytes: 4 byte packed device number, 4 inode */
 313                 /* This is *host* endian, not net-byte-order, because
 314                  * no-one outside this host has any business interpreting it
 315                  */
 316                 if (fsidlen != 8)
 317                         goto out;
 318                 memcpy(&dev, fsid, 4);
 319                 memcpy(&inode, fsid+4, 4);
 320                 major = (dev & 0xfff00) >> 8;
 321                 minor = (dev & 0xff) | ((dev >> 12) & 0xfff00);
 322                 break;
 323
 324         case FSID_UUID4_INUM: /* 4 byte inode number and 4 byte uuid */
 325                 if (fsidlen != 8)
 326                         goto out;
 327                 memcpy(&inode, fsid, 4);
 328                 uuidlen = 4;
 329                 fhuuid = fsid+4;
 330                 break;
 331         case FSID_UUID8: /* 8 byte uuid */
 332                 if (fsidlen != 8)
 333                         goto out;
 334                 uuidlen = 8;
 335                 fhuuid = fsid;
 336                 break;
 337         case FSID_UUID16: /* 16 byte uuid */
 338                 if (fsidlen != 16)
 339                         goto out;
 340                 uuidlen = 16;
 341                 fhuuid = fsid;
 342                 break;
 343         case FSID_UUID16_INUM: /* 8 byte inode number and 16 byte uuid */
 344                 if (fsidlen != 24)
 345                         goto out;
 346                 memcpy(&inode64, fsid, 8);
 347                 inode = inode64;
 348                 uuidlen = 16;
 349                 fhuuid = fsid+8;
 350                 break;
 351         }
 352
 353         auth_reload();
 354
 355         /* Now determine export point for this fsid/domain */
 356         for (i=0 ; i < MCL_MAXTYPES; i++) {
 357                 nfs_export *next_exp;
 358                 for (exp = exportlist[i]; exp; exp = next_exp) {
 359                         struct stat stb;
 360                         char u[16];
 361                         char *path;
 362
 363                         if (exp->m_export.e_flags & NFSEXP_CROSSMOUNT) {
 364                                 static nfs_export *prev = NULL;
 365                                 static void *mnt = NULL;
 366
 367                                 if (prev == exp) {
 368                                         /* try a submount */
 369                                         path = next_mnt(&mnt, exp->m_export.e_path);
 370                                         if (!path) {
 371                                                 next_exp = exp->m_next;
 372                                                 prev = NULL;
 373                                                 continue;
 374                                         }
 375                                         next_exp = exp;
 376                                 } else {
 377                                         prev = exp;
 378                                         mnt = NULL;
 379                                         path = exp->m_export.e_path;
 380                                         next_exp = exp;
 381                                 }
 382                         } else {
 383                                 path = exp->m_export.e_path;
 384                                 next_exp = exp->m_next;
 385                         }
 386
 387                         if (!client_member(dom, exp->m_client->m_hostname))
 388                                 continue;
 389                         if (exp->m_export.e_mountpoint &&
 390                             !is_mountpoint(exp->m_export.e_mountpoint[0]?
 391                                            exp->m_export.e_mountpoint:
 392                                            exp->m_export.e_path))
 393                                 dev_missing ++;
 394                         if (stat(path, &stb) != 0)
 395                                 continue;
 396                         switch(fsidtype){
 397                         case FSID_DEV:
 398                         case FSID_MAJOR_MINOR:
 399                         case FSID_ENCODE_DEV:
 400                                 if (stb.st_ino != inode)
 401                                         continue;
 402                                 if (major != major(stb.st_dev) ||
 403                                     minor != minor(stb.st_dev))
 404                                         continue;
 405                                 break;
 406                         case FSID_NUM:
 407                                 if (((exp->m_export.e_flags & NFSEXP_FSID) == 0 ||
 408                                      exp->m_export.e_fsid != fsidnum))
 409                                         continue;
 410                                 break;
 411                         case FSID_UUID4_INUM:
 412                         case FSID_UUID16_INUM:
 413                                 if (stb.st_ino != inode)
 414                                         continue;
 415                                 goto check_uuid;
 416                         case FSID_UUID8:
 417                         case FSID_UUID16:
 418                                 if (!is_mountpoint(path))
 419                                         continue;
 420                         check_uuid:
 421                                 if (exp->m_export.e_uuid)
 422                                         get_uuid(NULL, exp->m_export.e_uuid,
 423                                                  uuidlen, u);
 424                                 else if (get_uuid(path, NULL,
 425                                                   uuidlen, u) == 0)
 426                                         continue;
 427
 428                                 if (memcmp(u, fhuuid, uuidlen) != 0)
 429                                         continue;
 430                                 break;
 431                         }
 432                         /* It's a match !! */
 433                         if (!found) {
 434                                 found = &exp->m_export;
 435                                 found_path = strdup(path);
 436                         } else if (strcmp(found->e_path, exp->m_export.e_path)!= 0)
 437                         {
 438                                 xlog(L_WARNING, "%s and %s have same filehandle for %s, using first",
 439                                      found_path, path, dom);
 440                         }
 441                 }
 442         }
 443         if (found &&
 444             found->e_mountpoint &&
 445             !is_mountpoint(found->e_mountpoint[0]?
 446                            found->e_mountpoint:
 447                            found->e_path)) {
 448                 /* Cannot export this yet
 449                  * should log a warning, but need to rate limit
 450                    xlog(L_WARNING, "%s not exported as %d not a mountpoint",
 451                    found->e_path, found->e_mountpoint);
 452                  */
 453                 /* FIXME we need to make sure we re-visit this later */
 454                 goto out;
 455         }
 456         if (!found && dev_missing) {
 457                 /* The missing dev could be what we want, so just be
 458                  * quite rather than returning stale yet
 459                  */
 460                 goto out;
 461         }
 462
 463         if (found)
 464                 cache_export_ent(dom, found, found_path);
 465
 466         qword_print(f, dom);
 467         qword_printint(f, fsidtype);
 468         qword_printhex(f, fsid, fsidlen);
 469         /* The fsid -> path lookup can be quite expensive as it
 470          * potentially stats and reads lots of devices, and some of those
 471          * might have spun-down.  The Answer is not likely to
 472          * change underneath us, and an 'exportfs -f' can always
 473          * remove this from the kernel, so use a really log
 474          * timeout.  Maybe this should be configurable on the command
 475          * line.
 476          */
 477         qword_printint(f, 0x7fffffff);
 478         if (found)
 479                 qword_print(f, found->e_path);
 480         qword_eol(f);
 481  out:
 482         free(dom);
 483         return;
 484 }
 485
 486 static void write_fsloc(FILE *f, struct exportent *ep, char *path)
 487 {
 488         struct servers *servers;
 489
 490         if (ep->e_fslocmethod == FSLOC_NONE)
 491                 return;
 492
 493         servers = replicas_lookup(ep->e_fslocmethod, ep->e_fslocdata, path);
 494         if (!servers)
 495                 return;
 496         qword_print(f, "fsloc");
 497         qword_printint(f, servers->h_num);
 498         if (servers->h_num >= 0) {
 499                 int i;
 500                 for (i=0; i<servers->h_num; i++) {
 501                         qword_print(f, servers->h_mp[i]->h_host);
 502                         qword_print(f, servers->h_mp[i]->h_path);
 503                 }
 504         }
 505         qword_printint(f, servers->h_referral);
 506         release_replicas(servers);
 507 }
 508
 509 static int dump_to_cache(FILE *f, char *domain, char *path, struct exportent *exp)
 510 {
 511         qword_print(f, domain);
 512         qword_print(f, path);
 513         qword_printint(f, time(0)+30*60);
 514         if (exp) {
 515                 qword_printint(f, exp->e_flags);
 516                 qword_printint(f, exp->e_anonuid);
 517                 qword_printint(f, exp->e_anongid);
 518                 qword_printint(f, exp->e_fsid);
 519                 write_fsloc(f, exp, path);
 520                 if (exp->e_uuid == NULL) {
 521                         char u[16];
 522                         if (get_uuid(path, NULL, 16, u)) {
 523                                 qword_print(f, "uuid");
 524                                 qword_printhex(f, u, 16);
 525                         }
 526                 } else if (exp->e_uuid) {
 527                         qword_print(f, "uuid");
 528                         qword_printhex(f, exp->e_uuid, 16);
 529                 }
 530         }
 531         return qword_eol(f);
 532 }
 533
 534 void nfsd_export(FILE *f)
 535 {
 536         /* requests are:
 537          *  domain path
 538          * determine export options and return:
 539          *  domain path expiry flags anonuid anongid fsid
 540          */
 541
 542         char *cp;
 543         int i;
 544         char *dom, *path;
 545         nfs_export *exp, *found = NULL;
 546         int found_type = 0;
 547
 548
 549         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
 550                 return;
 551
 552         cp = lbuf;
 553         dom = malloc(strlen(cp));
 554         path = malloc(strlen(cp));
 555
 556         if (!dom || !path)
 557                 goto out;
 558
 559         if (qword_get(&cp, dom, strlen(lbuf)) <= 0)
 560                 goto out;
 561         if (qword_get(&cp, path, strlen(lbuf)) <= 0)
 562                 goto out;
 563
 564         auth_reload();
 565
 566         /* now find flags for this export point in this domain */
 567         for (i=0 ; i < MCL_MAXTYPES; i++) {
 568                 for (exp = exportlist[i]; exp; exp = exp->m_next) {
 569                         if (!client_member(dom, exp->m_client->m_hostname))
 570                                 continue;
 571                         if (exp->m_export.e_flags & NFSEXP_CROSSMOUNT) {
 572                                 /* if path is a mountpoint below e_path, then OK */
 573                                 int l = strlen(exp->m_export.e_path);
 574                                 if (strcmp(path, exp->m_export.e_path) == 0 ||
 575                                     (strncmp(path, exp->m_export.e_path, l) == 0 &&
 576                                      path[l] == '/' &&
 577                                      is_mountpoint(path)))
 578                                         /* ok */;
 579                                 else
 580                                         continue;
 581                         } else if (strcmp(path, exp->m_export.e_path) != 0)
 582                                 continue;
 583                         if (!found) {
 584                                 found = exp;
 585                                 found_type = i;
 586                                 continue;
 587                         }
 588                         /* If one is a CROSSMOUNT, then prefer the longest path */
 589                         if (((found->m_export.e_flags & NFSEXP_CROSSMOUNT) ||
 590                              (found->m_export.e_flags & NFSEXP_CROSSMOUNT)) &&
 591                             strlen(found->m_export.e_path) !=
 592                             strlen(found->m_export.e_path)) {
 593
 594                                 if (strlen(exp->m_export.e_path) >
 595                                     strlen(found->m_export.e_path)) {
 596                                         found = exp;
 597                                         found_type = i;
 598                                 }
 599                                 continue;
 600
 601                         } else if (found_type == i && found->m_warned == 0) {
 602                                 xlog(L_WARNING, "%s exported to both %s and %s, "
 603                                      "arbitrarily choosing options from first",
 604                                      path, found->m_client->m_hostname, exp->m_client->m_hostname,
 605                                      dom);
 606                                 found->m_warned = 1;
 607                         }
 608                 }
 609         }
 610
 611         if (found) {
 612                 dump_to_cache(f, dom, path, &found->m_export);
 613                 mountlist_add(dom, path);
 614         } else {
 615                 dump_to_cache(f, dom, path, NULL);
 616         }
 617  out:
 618         if (dom) free(dom);
 619         if (path) free(path);
 620 }
 621
 622
 623 struct {
 624         char *cache_name;
 625         void (*cache_handle)(FILE *f);
 626         FILE *f;
 627 } cachelist[] = {
 628         { "auth.unix.ip", auth_unix_ip},
 629         { "auth.unix.gid", auth_unix_gid},
 630         { "nfsd.export", nfsd_export},
 631         { "nfsd.fh", nfsd_fh},
 632         { NULL, NULL }
 633 };
 634
 635 extern int manage_gids;
 636 void cache_open(void)
 637 {
 638         int i;
 639         for (i=0; cachelist[i].cache_name; i++ ) {
 640                 char path[100];
 641                 if (!manage_gids && cachelist[i].cache_handle == auth_unix_gid)
 642                         continue;
 643                 sprintf(path, "/proc/net/rpc/%s/channel", cachelist[i].cache_name);
 644                 cachelist[i].f = fopen(path, "r+");
 645         }
 646 }
 647
 648 void cache_set_fds(fd_set *fdset)
 649 {
 650         int i;
 651         for (i=0; cachelist[i].cache_name; i++) {
 652                 if (cachelist[i].f)
 653                         FD_SET(fileno(cachelist[i].f), fdset);
 654         }
 655 }
 656
 657 int cache_process_req(fd_set *readfds)
 658 {
 659         int i;
 660         int cnt = 0;
 661         for (i=0; cachelist[i].cache_name; i++) {
 662                 if (cachelist[i].f != NULL &&
 663                     FD_ISSET(fileno(cachelist[i].f), readfds)) {
 664                         cnt++;
 665                         cachelist[i].cache_handle(cachelist[i].f);
 666                         FD_CLR(fileno(cachelist[i].f), readfds);
 667                 }
 668         }
 669         return cnt;
 670 }
 671
 672
 673 /*
 674  * Give IP->domain and domain+path->options to kernel
 675  * % echo nfsd $IP  $[now+30*60] $domain > /proc/net/rpc/auth.unix.ip/channel
 676  * % echo $domain $path $[now+30*60] $options $anonuid $anongid $fsid > /proc/net/rpc/nfsd.export/channel
 677  */
 678
 679 int cache_export_ent(char *domain, struct exportent *exp, char *path)
 680 {
 681         int err;
 682         FILE *f = fopen("/proc/net/rpc/nfsd.export/channel", "w");
 683         if (!f)
 684                 return -1;
 685
 686         err = dump_to_cache(f, domain, exp->e_path, exp);
 687         mountlist_add(domain, exp->e_path);
 688
 689         while ((exp->e_flags & NFSEXP_CROSSMOUNT) && path) {
 690                 /* really an 'if', but we can break out of
 691                  * a 'while' more easily */
 692                 /* Look along 'path' for other filesystems
 693                  * and export them with the same options
 694                  */
 695                 struct stat stb;
 696                 int l = strlen(exp->e_path);
 697                 int dev;
 698
 699                 if (strlen(path) <= l || path[l] != '/' ||
 700                     strncmp(exp->e_path, path, l) != 0)
 701                         break;
 702                 if (stat(exp->e_path, &stb) != 0)
 703                         break;
 704                 dev = stb.st_dev;
 705                 while(path[l] == '/') {
 706                         char c;
 707                         int err;
 708
 709                         l++;
 710                         while (path[l] != '/' && path[l])
 711                                 l++;
 712                         c = path[l];
 713                         path[l] = 0;
 714                         err = lstat(path, &stb);
 715                         path[l] = c;
 716                         if (err < 0)
 717                                 break;
 718                         if (stb.st_dev == dev)
 719                                 continue;
 720                         dev = stb.st_dev;
 721                         path[l] = 0;
 722                         dump_to_cache(f, domain, path, exp);
 723                         path[l] = c;
 724                 }
 725                 break;
 726         }
 727
 728         fclose(f);
 729         return err;
 730 }
 731
 732 int cache_export(nfs_export *exp, char *path)
 733 {
 734         int err;
 735         FILE *f;
 736
 737         f = fopen("/proc/net/rpc/auth.unix.ip/channel", "w");
 738         if (!f)
 739                 return -1;
 740
 741         qword_print(f, "nfsd");
 742         qword_print(f, inet_ntoa(exp->m_client->m_addrlist[0]));
 743         qword_printint(f, time(0)+30*60);
 744         qword_print(f, exp->m_client->m_hostname);
 745         err = qword_eol(f);
 746
 747         fclose(f);
 748
 749         err = cache_export_ent(exp->m_client->m_hostname, &exp->m_export, path)
 750                 || err;
 751         return err;
 752 }
 753
 754 /* Get a filehandle.
 755  * {
 756  *   echo $domain $path $length
 757  *   read filehandle <&0
 758  * } <> /proc/fs/nfsd/filehandle
 759  */
 760 struct nfs_fh_len *
 761 cache_get_filehandle(nfs_export *exp, int len, char *p)
 762 {
 763         FILE *f = fopen("/proc/fs/nfsd/filehandle", "r+");
 764         char buf[200];
 765         char *bp = buf;
 766         int failed;
 767         static struct nfs_fh_len fh;
 768
 769         if (!f)
 770                 f = fopen("/proc/fs/nfs/filehandle", "r+");
 771         if (!f)
 772                 return NULL;
 773
 774         qword_print(f, exp->m_client->m_hostname);
 775         qword_print(f, p);
 776         qword_printint(f, len);
 777         failed = qword_eol(f);
 778
 779         if (!failed)
 780                 failed = (fgets(buf, sizeof(buf), f) == NULL);
 781         fclose(f);
 782         if (failed)
 783                 return NULL;
 784         memset(fh.fh_handle, 0, sizeof(fh.fh_handle));
 785         fh.fh_size = qword_get(&bp, (char *)fh.fh_handle, NFS3_FHSIZE);
 786         return &fh;
 787 }
 788