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 <sys/vfs.h>
  18 #include <time.h>
  19 #include <netinet/in.h>
  20 #include <arpa/inet.h>
  21 #include <unistd.h>
  22 #include <fcntl.h>
  23 #include <errno.h>
  24 #include <ctype.h>
  25 #include <pwd.h>
  26 #include <grp.h>
  27 #include <mntent.h>
  28 #include "misc.h"
  29 #include "nfslib.h"
  30 #include "exportfs.h"
  31 #include "mountd.h"
  32 #include "xmalloc.h"
  33 #include "fsloc.h"
  34 #include "pseudoflavors.h"
  35
  36 #ifdef USE_BLKID
  37 #include "blkid/blkid.h"
  38 #endif
  39
  40
  41 enum nfsd_fsid {
  42         FSID_DEV = 0,
  43         FSID_NUM,
  44         FSID_MAJOR_MINOR,
  45         FSID_ENCODE_DEV,
  46         FSID_UUID4_INUM,
  47         FSID_UUID8,
  48         FSID_UUID16,
  49         FSID_UUID16_INUM,
  50 };
  51
  52 /*
  53  * Support routines for text-based upcalls.
  54  * Fields are separated by spaces.
  55  * Fields are either mangled to quote space tab newline slosh with slosh
  56  * or a hexified with a leading \x
  57  * Record is terminated with newline.
  58  *
  59  */
  60 int cache_export_ent(char *domain, struct exportent *exp, char *p);
  61
  62
  63 char *lbuf  = NULL;
  64 int lbuflen = 0;
  65 extern int use_ipaddr;
  66
  67 void auth_unix_ip(FILE *f)
  68 {
  69         /* requests are
  70          *  class IP-ADDR
  71          * Ignore if class != "nfsd"
  72          * Otherwise find domainname and write back:
  73          *
  74          *  "nfsd" IP-ADDR expiry domainname
  75          */
  76         char *cp;
  77         char class[20];
  78         char ipaddr[20];
  79         char *client = NULL;
  80         struct in_addr addr;
  81         struct hostent *he = NULL;
  82         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
  83                 return;
  84
  85         xlog(D_CALL, "auth_unix_ip: inbuf '%s'", lbuf);
  86
  87         cp = lbuf;
  88
  89         if (qword_get(&cp, class, 20) <= 0 ||
  90             strcmp(class, "nfsd") != 0)
  91                 return;
  92
  93         if (qword_get(&cp, ipaddr, 20) <= 0)
  94                 return;
  95
  96         if (inet_aton(ipaddr, &addr)==0)
  97                 return;
  98
  99         auth_reload();
 100
 101         /* addr is a valid, interesting address, find the domain name... */
 102         if (!use_ipaddr) {
 103                 he = client_resolve(addr);
 104                 client = client_compose(he);
 105         }
 106
 107         qword_print(f, "nfsd");
 108         qword_print(f, ipaddr);
 109         qword_printint(f, time(0)+30*60);
 110         if (use_ipaddr)
 111                 qword_print(f, ipaddr);
 112         else if (client)
 113                 qword_print(f, *client?client:"DEFAULT");
 114         qword_eol(f);
 115         xlog(D_CALL, "auth_unix_ip: client %p '%s'", client, client?client: "DEFAULT");
 116
 117         if (client) free(client);
 118         free(he);
 119 }
 120
 121 void auth_unix_gid(FILE *f)
 122 {
 123         /* Request are
 124          *  uid
 125          * reply is
 126          *  uid expiry count list of group ids
 127          */
 128         uid_t uid;
 129         struct passwd *pw;
 130         gid_t glist[100], *groups = glist;
 131         int ngroups = 100;
 132         int rv, i;
 133         char *cp;
 134
 135         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
 136                 return;
 137
 138         cp = lbuf;
 139         if (qword_get_uint(&cp, &uid) != 0)
 140                 return;
 141
 142         pw = getpwuid(uid);
 143         if (!pw)
 144                 rv = -1;
 145         else {
 146                 rv = getgrouplist(pw->pw_name, pw->pw_gid, groups, &ngroups);
 147                 if (rv == -1 && ngroups >= 100) {
 148                         groups = malloc(sizeof(gid_t)*ngroups);
 149                         if (!groups)
 150                                 rv = -1;
 151                         else
 152                                 rv = getgrouplist(pw->pw_name, pw->pw_gid,
 153                                                   groups, &ngroups);
 154                 }
 155         }
 156         qword_printuint(f, uid);
 157         qword_printuint(f, time(0)+30*60);
 158         if (rv >= 0) {
 159                 qword_printuint(f, ngroups);
 160                 for (i=0; i<ngroups; i++)
 161                         qword_printuint(f, groups[i]);
 162         } else
 163                 qword_printuint(f, 0);
 164         qword_eol(f);
 165
 166         if (groups != glist)
 167                 free(groups);
 168 }
 169
 170 #if USE_BLKID
 171 static const char *get_uuid_blkdev(char *path)
 172 {
 173         /* We set *safe if we know that we need the
 174          * fsid from statfs too.
 175          */
 176         static blkid_cache cache = NULL;
 177         struct stat stb;
 178         char *devname;
 179         blkid_tag_iterate iter;
 180         blkid_dev dev;
 181         const char *type;
 182         const char *val, *uuid = NULL;
 183
 184         if (cache == NULL)
 185                 blkid_get_cache(&cache, NULL);
 186
 187         if (stat(path, &stb) != 0)
 188                 return NULL;
 189         devname = blkid_devno_to_devname(stb.st_dev);
 190         if (!devname)
 191                 return NULL;
 192         dev = blkid_get_dev(cache, devname, BLKID_DEV_NORMAL);
 193         free(devname);
 194         if (!dev)
 195                 return NULL;
 196         iter = blkid_tag_iterate_begin(dev);
 197         if (!iter)
 198                 return NULL;
 199         while (blkid_tag_next(iter, &type, &val) == 0) {
 200                 if (strcmp(type, "UUID") == 0)
 201                         uuid = val;
 202                 if (strcmp(type, "TYPE") == 0 &&
 203                     strcmp(val, "btrfs") == 0) {
 204                         uuid = NULL;
 205                         break;
 206                 }
 207         }
 208         blkid_tag_iterate_end(iter);
 209         return uuid;
 210 }
 211 #else
 212 #define get_uuid_blkdev(path) (NULL)
 213 #endif
 214
 215 int get_uuid(const char *val, int uuidlen, char *u)
 216 {
 217         /* extract hex digits from uuidstr and compose a uuid
 218          * of the given length (max 16), xoring bytes to make
 219          * a smaller uuid.
 220          */
 221         int i = 0;
 222
 223         memset(u, 0, uuidlen);
 224         for ( ; *val ; val++) {
 225                 char c = *val;
 226                 if (!isxdigit(c))
 227                         continue;
 228                 if (isalpha(c)) {
 229                         if (isupper(c))
 230                                 c = c - 'A' + 10;
 231                         else
 232                                 c = c - 'a' + 10;
 233                 } else
 234                         c = c - '0' + 0;
 235                 if ((i&1) == 0)
 236                         c <<= 4;
 237                 u[i/2] ^= c;
 238                 i++;
 239                 if (i == uuidlen*2)
 240                         i = 0;
 241         }
 242         return 1;
 243 }
 244
 245 int uuid_by_path(char *path, int type, int uuidlen, char *uuid)
 246 {
 247         /* get a uuid for the filesystem found at 'path'.
 248          * There are several possible ways of generating the
 249          * uuids (types).
 250          * Type 0 is used for new filehandles, while other types
 251          * may be used to interpret old filehandle - to ensure smooth
 252          * forward migration.
 253          * We return 1 if a uuid was found (and it might be worth
 254          * trying the next type) or 0 if no more uuid types can be
 255          * extracted.
 256          */
 257
 258         /* Possible sources of uuid are
 259          * - blkid uuid
 260          * - statfs64 uuid
 261          *
 262          * On some filesystems (e.g. vfat) the statfs64 uuid is simply an
 263          * encoding of the device that the filesystem is mounted from, so
 264          * it we be very bad to use that (as device numbers change).  blkid
 265          * must be preferred.
 266          * On other filesystems (e.g. btrfs) the statfs64 uuid contains
 267          * important info that the blkid uuid cannot contain:  This happens
 268          * when multiple subvolumes are exported (they have the same
 269          * blkid uuid but different statfs64 uuids).
 270          * We rely on get_uuid_blkdev *knowing* which is which and not returning
 271          * a uuid for filesystems where the statfs64 uuid is better.
 272          *
 273          */
 274         struct statfs64 st;
 275         char fsid_val[17];
 276         const char *blkid_val;
 277         const char *val;
 278
 279         blkid_val = get_uuid_blkdev(path);
 280
 281         if (statfs64(path, &st) == 0 &&
 282             (st.f_fsid.__val[0] || st.f_fsid.__val[1]))
 283                 snprintf(fsid_val, 17, "%08x%08x",
 284                          st.f_fsid.__val[0], st.f_fsid.__val[1]);
 285         else
 286                 fsid_val[0] = 0;
 287
 288         if (blkid_val && (type--) == 0)
 289                 val = blkid_val;
 290         else if (fsid_val[0] && (type--) == 0)
 291                 val = fsid_val;
 292         else
 293                 return 0;
 294
 295         get_uuid(val, uuidlen, uuid);
 296         return 1;
 297 }
 298
 299 /* Iterate through /etc/mtab, finding mountpoints
 300  * at or below a given path
 301  */
 302 static char *next_mnt(void **v, char *p)
 303 {
 304         FILE *f;
 305         struct mntent *me;
 306         int l = strlen(p);
 307         if (*v == NULL) {
 308                 f = setmntent("/etc/mtab", "r");
 309                 *v = f;
 310         } else
 311                 f = *v;
 312         while ((me = getmntent(f)) != NULL &&
 313                (strncmp(me->mnt_dir, p, l) != 0 ||
 314                 me->mnt_dir[l] != '/'))
 315                 ;
 316         if (me == NULL) {
 317                 endmntent(f);
 318                 *v = NULL;
 319                 return NULL;
 320         }
 321         return me->mnt_dir;
 322 }
 323
 324 void nfsd_fh(FILE *f)
 325 {
 326         /* request are:
 327          *  domain fsidtype fsid
 328          * interpret fsid, find export point and options, and write:
 329          *  domain fsidtype fsid expiry path
 330          */
 331         char *cp;
 332         char *dom;
 333         int fsidtype;
 334         int fsidlen;
 335         unsigned int dev, major=0, minor=0;
 336         unsigned int inode=0;
 337         unsigned long long inode64;
 338         unsigned int fsidnum=0;
 339         char fsid[32];
 340         struct exportent *found = NULL;
 341         struct hostent *he = NULL;
 342         struct in_addr addr;
 343         char *found_path = NULL;
 344         nfs_export *exp;
 345         int i;
 346         int dev_missing = 0;
 347         int uuidlen = 0;
 348         char *fhuuid = NULL;
 349
 350         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
 351                 return;
 352
 353         xlog(D_CALL, "nfsd_fh: inbuf '%s'", lbuf);
 354
 355         cp = lbuf;
 356
 357         dom = malloc(strlen(cp));
 358         if (dom == NULL)
 359                 return;
 360         if (qword_get(&cp, dom, strlen(cp)) <= 0)
 361                 goto out;
 362         if (qword_get_int(&cp, &fsidtype) != 0)
 363                 goto out;
 364         if (fsidtype < 0 || fsidtype > 7)
 365                 goto out; /* unknown type */
 366         if ((fsidlen = qword_get(&cp, fsid, 32)) <= 0)
 367                 goto out;
 368         switch(fsidtype) {
 369         case FSID_DEV: /* 4 bytes: 2 major, 2 minor, 4 inode */
 370                 if (fsidlen != 8)
 371                         goto out;
 372                 memcpy(&dev, fsid, 4);
 373                 memcpy(&inode, fsid+4, 4);
 374                 major = ntohl(dev)>>16;
 375                 minor = ntohl(dev) & 0xFFFF;
 376                 break;
 377
 378         case FSID_NUM: /* 4 bytes - fsid */
 379                 if (fsidlen != 4)
 380                         goto out;
 381                 memcpy(&fsidnum, fsid, 4);
 382                 break;
 383
 384         case FSID_MAJOR_MINOR: /* 12 bytes: 4 major, 4 minor, 4 inode
 385                  * This format is never actually used but was
 386                  * an historical accident
 387                  */
 388                 if (fsidlen != 12)
 389                         goto out;
 390                 memcpy(&dev, fsid, 4); major = ntohl(dev);
 391                 memcpy(&dev, fsid+4, 4); minor = ntohl(dev);
 392                 memcpy(&inode, fsid+8, 4);
 393                 break;
 394
 395         case FSID_ENCODE_DEV: /* 8 bytes: 4 byte packed device number, 4 inode */
 396                 /* This is *host* endian, not net-byte-order, because
 397                  * no-one outside this host has any business interpreting it
 398                  */
 399                 if (fsidlen != 8)
 400                         goto out;
 401                 memcpy(&dev, fsid, 4);
 402                 memcpy(&inode, fsid+4, 4);
 403                 major = (dev & 0xfff00) >> 8;
 404                 minor = (dev & 0xff) | ((dev >> 12) & 0xfff00);
 405                 break;
 406
 407         case FSID_UUID4_INUM: /* 4 byte inode number and 4 byte uuid */
 408                 if (fsidlen != 8)
 409                         goto out;
 410                 memcpy(&inode, fsid, 4);
 411                 uuidlen = 4;
 412                 fhuuid = fsid+4;
 413                 break;
 414         case FSID_UUID8: /* 8 byte uuid */
 415                 if (fsidlen != 8)
 416                         goto out;
 417                 uuidlen = 8;
 418                 fhuuid = fsid;
 419                 break;
 420         case FSID_UUID16: /* 16 byte uuid */
 421                 if (fsidlen != 16)
 422                         goto out;
 423                 uuidlen = 16;
 424                 fhuuid = fsid;
 425                 break;
 426         case FSID_UUID16_INUM: /* 8 byte inode number and 16 byte uuid */
 427                 if (fsidlen != 24)
 428                         goto out;
 429                 memcpy(&inode64, fsid, 8);
 430                 inode = inode64;
 431                 uuidlen = 16;
 432                 fhuuid = fsid+8;
 433                 break;
 434         }
 435
 436         auth_reload();
 437
 438         /* Now determine export point for this fsid/domain */
 439         for (i=0 ; i < MCL_MAXTYPES; i++) {
 440                 nfs_export *next_exp;
 441                 for (exp = exportlist[i].p_head; exp; exp = next_exp) {
 442                         struct stat stb;
 443                         char u[16];
 444                         char *path;
 445                         int type;
 446
 447                         if (exp->m_export.e_flags & NFSEXP_CROSSMOUNT) {
 448                                 static nfs_export *prev = NULL;
 449                                 static void *mnt = NULL;
 450
 451                                 if (prev == exp) {
 452                                         /* try a submount */
 453                                         path = next_mnt(&mnt, exp->m_export.e_path);
 454                                         if (!path) {
 455                                                 next_exp = exp->m_next;
 456                                                 prev = NULL;
 457                                                 continue;
 458                                         }
 459                                         next_exp = exp;
 460                                 } else {
 461                                         prev = exp;
 462                                         mnt = NULL;
 463                                         path = exp->m_export.e_path;
 464                                         next_exp = exp;
 465                                 }
 466                         } else {
 467                                 path = exp->m_export.e_path;
 468                                 next_exp = exp->m_next;
 469                         }
 470
 471                         if (!use_ipaddr && !client_member(dom, exp->m_client->m_hostname))
 472                                 continue;
 473                         if (exp->m_export.e_mountpoint &&
 474                             !is_mountpoint(exp->m_export.e_mountpoint[0]?
 475                                            exp->m_export.e_mountpoint:
 476                                            exp->m_export.e_path))
 477                                 dev_missing ++;
 478                         if (stat(path, &stb) != 0)
 479                                 continue;
 480                         if (!S_ISDIR(stb.st_mode) && !S_ISREG(stb.st_mode)) {
 481                                 continue;
 482                         }
 483                         switch(fsidtype){
 484                         case FSID_DEV:
 485                         case FSID_MAJOR_MINOR:
 486                         case FSID_ENCODE_DEV:
 487                                 if (stb.st_ino != inode)
 488                                         continue;
 489                                 if (major != major(stb.st_dev) ||
 490                                     minor != minor(stb.st_dev))
 491                                         continue;
 492                                 break;
 493                         case FSID_NUM:
 494                                 if (((exp->m_export.e_flags & NFSEXP_FSID) == 0 ||
 495                                      exp->m_export.e_fsid != fsidnum))
 496                                         continue;
 497                                 break;
 498                         case FSID_UUID4_INUM:
 499                         case FSID_UUID16_INUM:
 500                                 if (stb.st_ino != inode)
 501                                         continue;
 502                                 goto check_uuid;
 503                         case FSID_UUID8:
 504                         case FSID_UUID16:
 505                                 if (!is_mountpoint(path))
 506                                         continue;
 507                         check_uuid:
 508                                 if (exp->m_export.e_uuid)
 509                                         get_uuid(exp->m_export.e_uuid,
 510                                                  uuidlen, u);
 511                                 else
 512                                         for (type = 0;
 513                                              uuid_by_path(path, type, uuidlen, u);
 514                                              type++)
 515                                                 if (memcmp(u, fhuuid, uuidlen) != 0)
 516                                                         break;
 517
 518                                 if (memcmp(u, fhuuid, uuidlen) != 0)
 519                                         continue;
 520                                 break;
 521                         }
 522                         if (use_ipaddr) {
 523                                 if (he == NULL) {
 524                                         if (!inet_aton(dom, &addr))
 525                                                 goto out;
 526                                         he = client_resolve(addr);
 527                                 }
 528                                 if (!client_check(exp->m_client, he))
 529                                         continue;
 530                         }
 531                         /* It's a match !! */
 532                         if (!found) {
 533                                 found = &exp->m_export;
 534                                 found_path = strdup(path);
 535                                 if (found_path == NULL)
 536                                         goto out;
 537                         } else if (strcmp(found->e_path, exp->m_export.e_path)!= 0)
 538                         {
 539                                 xlog(L_WARNING, "%s and %s have same filehandle for %s, using first",
 540                                      found_path, path, dom);
 541                         }
 542                 }
 543         }
 544         if (found &&
 545             found->e_mountpoint &&
 546             !is_mountpoint(found->e_mountpoint[0]?
 547                            found->e_mountpoint:
 548                            found->e_path)) {
 549                 /* Cannot export this yet
 550                  * should log a warning, but need to rate limit
 551                    xlog(L_WARNING, "%s not exported as %d not a mountpoint",
 552                    found->e_path, found->e_mountpoint);
 553                  */
 554                 /* FIXME we need to make sure we re-visit this later */
 555                 goto out;
 556         }
 557         if (!found && dev_missing) {
 558                 /* The missing dev could be what we want, so just be
 559                  * quite rather than returning stale yet
 560                  */
 561                 goto out;
 562         }
 563
 564         if (found)
 565                 if (cache_export_ent(dom, found, found_path) < 0)
 566                         found = 0;
 567
 568         qword_print(f, dom);
 569         qword_printint(f, fsidtype);
 570         qword_printhex(f, fsid, fsidlen);
 571         /* The fsid -> path lookup can be quite expensive as it
 572          * potentially stats and reads lots of devices, and some of those
 573          * might have spun-down.  The Answer is not likely to
 574          * change underneath us, and an 'exportfs -f' can always
 575          * remove this from the kernel, so use a really log
 576          * timeout.  Maybe this should be configurable on the command
 577          * line.
 578          */
 579         qword_printint(f, 0x7fffffff);
 580         if (found)
 581                 qword_print(f, found_path);
 582         qword_eol(f);
 583  out:
 584         if (found_path)
 585                 free(found_path);
 586         if (he)
 587                 free(he);
 588         free(dom);
 589         xlog(D_CALL, "nfsd_fh: found %p path %s", found, found ? found->e_path : NULL);
 590         return;
 591 }
 592
 593 static void write_fsloc(FILE *f, struct exportent *ep, char *path)
 594 {
 595         struct servers *servers;
 596
 597         if (ep->e_fslocmethod == FSLOC_NONE)
 598                 return;
 599
 600         servers = replicas_lookup(ep->e_fslocmethod, ep->e_fslocdata, path);
 601         if (!servers)
 602                 return;
 603         qword_print(f, "fsloc");
 604         qword_printint(f, servers->h_num);
 605         if (servers->h_num >= 0) {
 606                 int i;
 607                 for (i=0; i<servers->h_num; i++) {
 608                         qword_print(f, servers->h_mp[i]->h_host);
 609                         qword_print(f, servers->h_mp[i]->h_path);
 610                 }
 611         }
 612         qword_printint(f, servers->h_referral);
 613         release_replicas(servers);
 614 }
 615
 616 static void write_secinfo(FILE *f, struct exportent *ep, int flag_mask)
 617 {
 618         struct sec_entry *p;
 619
 620         for (p = ep->e_secinfo; p->flav; p++)
 621                 ; /* Do nothing */
 622         if (p == ep->e_secinfo) {
 623                 /* There was no sec= option */
 624                 return;
 625         }
 626         qword_print(f, "secinfo");
 627         qword_printint(f, p - ep->e_secinfo);
 628         for (p = ep->e_secinfo; p->flav; p++) {
 629                 qword_printint(f, p->flav->fnum);
 630                 qword_printint(f, p->flags & flag_mask);
 631         }
 632
 633 }
 634
 635 static int dump_to_cache(FILE *f, char *domain, char *path, struct exportent *exp)
 636 {
 637         qword_print(f, domain);
 638         qword_print(f, path);
 639         qword_printint(f, time(0)+30*60);
 640         if (exp) {
 641                 int different_fs = strcmp(path, exp->e_path) != 0;
 642                 int flag_mask = different_fs ? ~NFSEXP_FSID : ~0;
 643
 644                 qword_printint(f, exp->e_flags & flag_mask);
 645                 qword_printint(f, exp->e_anonuid);
 646                 qword_printint(f, exp->e_anongid);
 647                 qword_printint(f, exp->e_fsid);
 648                 write_fsloc(f, exp, path);
 649                 write_secinfo(f, exp, flag_mask);
 650                 if (exp->e_uuid == NULL || different_fs) {
 651                         char u[16];
 652                         if (uuid_by_path(path, 0, 16, u)) {
 653                                 qword_print(f, "uuid");
 654                                 qword_printhex(f, u, 16);
 655                         }
 656                 } else {
 657                         char u[16];
 658                         get_uuid(exp->e_uuid, 16, u);
 659                         qword_print(f, "uuid");
 660                         qword_printhex(f, u, 16);
 661                 }
 662         }
 663         return qword_eol(f);
 664 }
 665
 666 static int is_subdirectory(char *child, char *parent)
 667 {
 668         int l = strlen(parent);
 669
 670         return strcmp(child, parent) == 0
 671                 || (strncmp(child, parent, l) == 0 && child[l] == '/');
 672 }
 673
 674 static int path_matches(nfs_export *exp, char *path)
 675 {
 676         if (exp->m_export.e_flags & NFSEXP_CROSSMOUNT)
 677                 return is_subdirectory(path, exp->m_export.e_path);
 678         return strcmp(path, exp->m_export.e_path) == 0;
 679 }
 680
 681 static int client_matches(nfs_export *exp, char *dom, struct hostent *he)
 682 {
 683         if (use_ipaddr)
 684                 return client_check(exp->m_client, he);
 685         return client_member(dom, exp->m_client->m_hostname);
 686 }
 687
 688 static int export_matches(nfs_export *exp, char *dom, char *path, struct hostent *he)
 689 {
 690         return path_matches(exp, path) && client_matches(exp, dom, he);
 691 }
 692
 693 static nfs_export *lookup_export(char *dom, char *path, struct hostent *he)
 694 {
 695         nfs_export *exp;
 696         nfs_export *found = NULL;
 697         int found_type = 0;
 698         int i;
 699
 700         for (i=0 ; i < MCL_MAXTYPES; i++) {
 701                 for (exp = exportlist[i].p_head; exp; exp = exp->m_next) {
 702                         if (!export_matches(exp, dom, path, he))
 703                                 continue;
 704                         if (!found) {
 705                                 found = exp;
 706                                 found_type = i;
 707                                 continue;
 708                         }
 709
 710                         /* Always prefer non-V4ROOT mounts */
 711                         if (found->m_export.e_flags & NFSEXP_V4ROOT)
 712                                 continue;
 713
 714                         /* If one is a CROSSMOUNT, then prefer the longest path */
 715                         if (((found->m_export.e_flags & NFSEXP_CROSSMOUNT) ||
 716                              (exp->m_export.e_flags & NFSEXP_CROSSMOUNT)) &&
 717                             strlen(found->m_export.e_path) !=
 718                             strlen(exp->m_export.e_path)) {
 719
 720                                 if (strlen(exp->m_export.e_path) >
 721                                     strlen(found->m_export.e_path)) {
 722                                         found = exp;
 723                                         found_type = i;
 724                                 }
 725                                 continue;
 726
 727                         } else if (found_type == i && found->m_warned == 0) {
 728                                 xlog(L_WARNING, "%s exported to both %s and %s, "
 729                                      "arbitrarily choosing options from first",
 730                                      path, found->m_client->m_hostname, exp->m_client->m_hostname,
 731                                      dom);
 732                                 found->m_warned = 1;
 733                         }
 734                 }
 735         }
 736         return found;
 737 }
 738
 739 void nfsd_export(FILE *f)
 740 {
 741         /* requests are:
 742          *  domain path
 743          * determine export options and return:
 744          *  domain path expiry flags anonuid anongid fsid
 745          */
 746
 747         char *cp;
 748         char *dom, *path;
 749         nfs_export *found = NULL;
 750         struct in_addr addr;
 751         struct hostent *he = NULL;
 752
 753
 754         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
 755                 return;
 756
 757         xlog(D_CALL, "nfsd_export: inbuf '%s'", lbuf);
 758
 759         cp = lbuf;
 760         dom = malloc(strlen(cp));
 761         path = malloc(strlen(cp));
 762
 763         if (!dom || !path)
 764                 goto out;
 765
 766         if (qword_get(&cp, dom, strlen(lbuf)) <= 0)
 767                 goto out;
 768         if (qword_get(&cp, path, strlen(lbuf)) <= 0)
 769                 goto out;
 770
 771         auth_reload();
 772
 773         if (use_ipaddr) {
 774                 if (!inet_aton(dom, &addr))
 775                         goto out;
 776                 he = client_resolve(addr);
 777         }
 778
 779         found = lookup_export(dom, path, he);
 780
 781         if (found) {
 782                 if (dump_to_cache(f, dom, path, &found->m_export) < 0) {
 783                         xlog(L_WARNING,
 784                              "Cannot export %s, possibly unsupported filesystem"
 785                              " or fsid= required", path);
 786                         dump_to_cache(f, dom, path, NULL);
 787                 }
 788         } else {
 789                 dump_to_cache(f, dom, path, NULL);
 790         }
 791  out:
 792         xlog(D_CALL, "nfsd_export: found %p path %s", found, path ? path : NULL);
 793         if (dom) free(dom);
 794         if (path) free(path);
 795         if (he) free(he);
 796 }
 797
 798
 799 struct {
 800         char *cache_name;
 801         void (*cache_handle)(FILE *f);
 802         FILE *f;
 803 } cachelist[] = {
 804         { "auth.unix.ip", auth_unix_ip},
 805         { "auth.unix.gid", auth_unix_gid},
 806         { "nfsd.export", nfsd_export},
 807         { "nfsd.fh", nfsd_fh},
 808         { NULL, NULL }
 809 };
 810
 811 extern int manage_gids;
 812 void cache_open(void)
 813 {
 814         int i;
 815         for (i=0; cachelist[i].cache_name; i++ ) {
 816                 char path[100];
 817                 if (!manage_gids && cachelist[i].cache_handle == auth_unix_gid)
 818                         continue;
 819                 sprintf(path, "/proc/net/rpc/%s/channel", cachelist[i].cache_name);
 820                 cachelist[i].f = fopen(path, "r+");
 821         }
 822 }
 823
 824 void cache_set_fds(fd_set *fdset)
 825 {
 826         int i;
 827         for (i=0; cachelist[i].cache_name; i++) {
 828                 if (cachelist[i].f)
 829                         FD_SET(fileno(cachelist[i].f), fdset);
 830         }
 831 }
 832
 833 int cache_process_req(fd_set *readfds)
 834 {
 835         int i;
 836         int cnt = 0;
 837         for (i=0; cachelist[i].cache_name; i++) {
 838                 if (cachelist[i].f != NULL &&
 839                     FD_ISSET(fileno(cachelist[i].f), readfds)) {
 840                         cnt++;
 841                         cachelist[i].cache_handle(cachelist[i].f);
 842                         FD_CLR(fileno(cachelist[i].f), readfds);
 843                 }
 844         }
 845         return cnt;
 846 }
 847
 848
 849 /*
 850  * Give IP->domain and domain+path->options to kernel
 851  * % echo nfsd $IP  $[now+30*60] $domain > /proc/net/rpc/auth.unix.ip/channel
 852  * % echo $domain $path $[now+30*60] $options $anonuid $anongid $fsid > /proc/net/rpc/nfsd.export/channel
 853  */
 854
 855 int cache_export_ent(char *domain, struct exportent *exp, char *path)
 856 {
 857         int err;
 858         FILE *f = fopen("/proc/net/rpc/nfsd.export/channel", "w");
 859         if (!f)
 860                 return -1;
 861
 862         err = dump_to_cache(f, domain, exp->e_path, exp);
 863         if (err) {
 864                 xlog(L_WARNING,
 865                      "Cannot export %s, possibly unsupported filesystem or"
 866                      " fsid= required", exp->e_path);
 867         }
 868
 869         while (err == 0 && (exp->e_flags & NFSEXP_CROSSMOUNT) && path) {
 870                 /* really an 'if', but we can break out of
 871                  * a 'while' more easily */
 872                 /* Look along 'path' for other filesystems
 873                  * and export them with the same options
 874                  */
 875                 struct stat stb;
 876                 int l = strlen(exp->e_path);
 877                 int dev;
 878
 879                 if (strlen(path) <= l || path[l] != '/' ||
 880                     strncmp(exp->e_path, path, l) != 0)
 881                         break;
 882                 if (stat(exp->e_path, &stb) != 0)
 883                         break;
 884                 dev = stb.st_dev;
 885                 while(path[l] == '/') {
 886                         char c;
 887                         /* errors for submount should fail whole filesystem */
 888                         int err2;
 889
 890                         l++;
 891                         while (path[l] != '/' && path[l])
 892                                 l++;
 893                         c = path[l];
 894                         path[l] = 0;
 895                         err2 = lstat(path, &stb);
 896                         path[l] = c;
 897                         if (err2 < 0)
 898                                 break;
 899                         if (stb.st_dev == dev)
 900                                 continue;
 901                         dev = stb.st_dev;
 902                         path[l] = 0;
 903                         dump_to_cache(f, domain, path, exp);
 904                         path[l] = c;
 905                 }
 906                 break;
 907         }
 908
 909         fclose(f);
 910         return err;
 911 }
 912
 913 int cache_export(nfs_export *exp, char *path)
 914 {
 915         char buf[INET_ADDRSTRLEN];
 916         int err;
 917         FILE *f;
 918
 919         f = fopen("/proc/net/rpc/auth.unix.ip/channel", "w");
 920         if (!f)
 921                 return -1;
 922
 923
 924         qword_print(f, "nfsd");
 925         qword_print(f,
 926                 host_ntop(get_addrlist(exp->m_client, 0), buf, sizeof(buf)));
 927         qword_printint(f, time(0)+30*60);
 928         qword_print(f, exp->m_client->m_hostname);
 929         err = qword_eol(f);
 930
 931         fclose(f);
 932
 933         err = cache_export_ent(exp->m_client->m_hostname, &exp->m_export, path)
 934                 || err;
 935         return err;
 936 }
 937
 938 /* Get a filehandle.
 939  * {
 940  *   echo $domain $path $length
 941  *   read filehandle <&0
 942  * } <> /proc/fs/nfsd/filehandle
 943  */
 944 struct nfs_fh_len *
 945 cache_get_filehandle(nfs_export *exp, int len, char *p)
 946 {
 947         FILE *f = fopen("/proc/fs/nfsd/filehandle", "r+");
 948         char buf[200];
 949         char *bp = buf;
 950         int failed;
 951         static struct nfs_fh_len fh;
 952
 953         if (!f)
 954                 f = fopen("/proc/fs/nfs/filehandle", "r+");
 955         if (!f)
 956                 return NULL;
 957
 958         qword_print(f, exp->m_client->m_hostname);
 959         qword_print(f, p);
 960         qword_printint(f, len);
 961         failed = qword_eol(f);
 962
 963         if (!failed)
 964                 failed = (fgets(buf, sizeof(buf), f) == NULL);
 965         fclose(f);
 966         if (failed)
 967                 return NULL;
 968         memset(fh.fh_handle, 0, sizeof(fh.fh_handle));
 969         fh.fh_size = qword_get(&bp, (char *)fh.fh_handle, NFS3_FHSIZE);
 970         return &fh;
 971 }
 972