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  * Invoked by RPC service loop
  42  */
  43 void    cache_set_fds(fd_set *fdset);
  44 int     cache_process_req(fd_set *readfds);
  45
  46 enum nfsd_fsid {
  47         FSID_DEV = 0,
  48         FSID_NUM,
  49         FSID_MAJOR_MINOR,
  50         FSID_ENCODE_DEV,
  51         FSID_UUID4_INUM,
  52         FSID_UUID8,
  53         FSID_UUID16,
  54         FSID_UUID16_INUM,
  55 };
  56
  57 /*
  58  * Support routines for text-based upcalls.
  59  * Fields are separated by spaces.
  60  * Fields are either mangled to quote space tab newline slosh with slosh
  61  * or a hexified with a leading \x
  62  * Record is terminated with newline.
  63  *
  64  */
  65 static int cache_export_ent(char *domain, struct exportent *exp, char *p);
  66
  67 #define INITIAL_MANAGED_GROUPS 100
  68
  69 char *lbuf  = NULL;
  70 int lbuflen = 0;
  71 extern int use_ipaddr;
  72
  73 static void auth_unix_ip(FILE *f)
  74 {
  75         /* requests are
  76          *  class IP-ADDR
  77          * Ignore if class != "nfsd"
  78          * Otherwise find domainname and write back:
  79          *
  80          *  "nfsd" IP-ADDR expiry domainname
  81          */
  82         char *cp;
  83         char class[20];
  84         char ipaddr[INET6_ADDRSTRLEN];
  85         char *client = NULL;
  86         struct addrinfo *tmp = NULL;
  87         struct addrinfo *ai = NULL;
  88         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
  89                 return;
  90
  91         xlog(D_CALL, "auth_unix_ip: inbuf '%s'", lbuf);
  92
  93         cp = lbuf;
  94
  95         if (qword_get(&cp, class, 20) <= 0 ||
  96             strcmp(class, "nfsd") != 0)
  97                 return;
  98
  99         if (qword_get(&cp, ipaddr, sizeof(ipaddr)) <= 0)
 100                 return;
 101
 102         tmp = host_pton(ipaddr);
 103         if (tmp == NULL)
 104                 return;
 105
 106         auth_reload();
 107
 108         /* addr is a valid, interesting address, find the domain name... */
 109         if (!use_ipaddr) {
 110                 ai = client_resolve(tmp->ai_addr);
 111                 client = client_compose(ai);
 112                 freeaddrinfo(ai);
 113         }
 114         freeaddrinfo(tmp);
 115
 116         qword_print(f, "nfsd");
 117         qword_print(f, ipaddr);
 118         qword_printuint(f, time(0) + DEFAULT_TTL);
 119         if (use_ipaddr)
 120                 qword_print(f, ipaddr);
 121         else if (client)
 122                 qword_print(f, *client?client:"DEFAULT");
 123         qword_eol(f);
 124         xlog(D_CALL, "auth_unix_ip: client %p '%s'", client, client?client: "DEFAULT");
 125
 126         free(client);
 127 }
 128
 129 static void auth_unix_gid(FILE *f)
 130 {
 131         /* Request are
 132          *  uid
 133          * reply is
 134          *  uid expiry count list of group ids
 135          */
 136         uid_t uid;
 137         struct passwd *pw;
 138         static gid_t *groups = NULL;
 139         static int groups_len = 0;
 140         gid_t *more_groups;
 141         int ngroups = 0;
 142         int rv, i;
 143         char *cp;
 144
 145         if (groups_len == 0) {
 146                 groups = malloc(sizeof(gid_t) * INITIAL_MANAGED_GROUPS);
 147                 if (!groups)
 148                         return;
 149
 150                 groups_len = ngroups = INITIAL_MANAGED_GROUPS;
 151         }
 152
 153         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
 154                 return;
 155
 156         cp = lbuf;
 157         if (qword_get_uint(&cp, &uid) != 0)
 158                 return;
 159
 160         pw = getpwuid(uid);
 161         if (!pw)
 162                 rv = -1;
 163         else {
 164                 rv = getgrouplist(pw->pw_name, pw->pw_gid, groups, &ngroups);
 165                 if (rv == -1 && ngroups >= groups_len) {
 166                         more_groups = realloc(groups, sizeof(gid_t)*ngroups);
 167                         if (!more_groups)
 168                                 rv = -1;
 169                         else {
 170                                 groups = more_groups;
 171                                 groups_len = ngroups;
 172                                 rv = getgrouplist(pw->pw_name, pw->pw_gid,
 173                                                   groups, &ngroups);
 174                         }
 175                 }
 176         }
 177         qword_printuint(f, uid);
 178         qword_printuint(f, time(0) + DEFAULT_TTL);
 179         if (rv >= 0) {
 180                 qword_printuint(f, ngroups);
 181                 for (i=0; i<ngroups; i++)
 182                         qword_printuint(f, groups[i]);
 183         } else
 184                 qword_printuint(f, 0);
 185         qword_eol(f);
 186 }
 187
 188 #if USE_BLKID
 189 static const char *get_uuid_blkdev(char *path)
 190 {
 191         /* We set *safe if we know that we need the
 192          * fsid from statfs too.
 193          */
 194         static blkid_cache cache = NULL;
 195         struct stat stb;
 196         char *devname;
 197         blkid_tag_iterate iter;
 198         blkid_dev dev;
 199         const char *type;
 200         const char *val, *uuid = NULL;
 201
 202         if (cache == NULL)
 203                 blkid_get_cache(&cache, NULL);
 204
 205         if (stat(path, &stb) != 0)
 206                 return NULL;
 207         devname = blkid_devno_to_devname(stb.st_dev);
 208         if (!devname)
 209                 return NULL;
 210         dev = blkid_get_dev(cache, devname, BLKID_DEV_NORMAL);
 211         free(devname);
 212         if (!dev)
 213                 return NULL;
 214         iter = blkid_tag_iterate_begin(dev);
 215         if (!iter)
 216                 return NULL;
 217         while (blkid_tag_next(iter, &type, &val) == 0) {
 218                 if (strcmp(type, "UUID") == 0)
 219                         uuid = val;
 220                 if (strcmp(type, "TYPE") == 0 &&
 221                     strcmp(val, "btrfs") == 0) {
 222                         uuid = NULL;
 223                         break;
 224                 }
 225         }
 226         blkid_tag_iterate_end(iter);
 227         return uuid;
 228 }
 229 #else
 230 #define get_uuid_blkdev(path) (NULL)
 231 #endif
 232
 233 static int get_uuid(const char *val, int uuidlen, char *u)
 234 {
 235         /* extract hex digits from uuidstr and compose a uuid
 236          * of the given length (max 16), xoring bytes to make
 237          * a smaller uuid.
 238          */
 239         int i = 0;
 240
 241         memset(u, 0, uuidlen);
 242         for ( ; *val ; val++) {
 243                 char c = *val;
 244                 if (!isxdigit(c))
 245                         continue;
 246                 if (isalpha(c)) {
 247                         if (isupper(c))
 248                                 c = c - 'A' + 10;
 249                         else
 250                                 c = c - 'a' + 10;
 251                 } else
 252                         c = c - '0' + 0;
 253                 if ((i&1) == 0)
 254                         c <<= 4;
 255                 u[i/2] ^= c;
 256                 i++;
 257                 if (i == uuidlen*2)
 258                         i = 0;
 259         }
 260         return 1;
 261 }
 262
 263 static int uuid_by_path(char *path, int type, int uuidlen, char *uuid)
 264 {
 265         /* get a uuid for the filesystem found at 'path'.
 266          * There are several possible ways of generating the
 267          * uuids (types).
 268          * Type 0 is used for new filehandles, while other types
 269          * may be used to interpret old filehandle - to ensure smooth
 270          * forward migration.
 271          * We return 1 if a uuid was found (and it might be worth
 272          * trying the next type) or 0 if no more uuid types can be
 273          * extracted.
 274          */
 275
 276         /* Possible sources of uuid are
 277          * - blkid uuid
 278          * - statfs64 uuid
 279          *
 280          * On some filesystems (e.g. vfat) the statfs64 uuid is simply an
 281          * encoding of the device that the filesystem is mounted from, so
 282          * it we be very bad to use that (as device numbers change).  blkid
 283          * must be preferred.
 284          * On other filesystems (e.g. btrfs) the statfs64 uuid contains
 285          * important info that the blkid uuid cannot contain:  This happens
 286          * when multiple subvolumes are exported (they have the same
 287          * blkid uuid but different statfs64 uuids).
 288          * We rely on get_uuid_blkdev *knowing* which is which and not returning
 289          * a uuid for filesystems where the statfs64 uuid is better.
 290          *
 291          */
 292         struct statfs64 st;
 293         char fsid_val[17];
 294         const char *blkid_val;
 295         const char *val;
 296
 297         blkid_val = get_uuid_blkdev(path);
 298
 299         if (statfs64(path, &st) == 0 &&
 300             (st.f_fsid.__val[0] || st.f_fsid.__val[1]))
 301                 snprintf(fsid_val, 17, "%08x%08x",
 302                          st.f_fsid.__val[0], st.f_fsid.__val[1]);
 303         else
 304                 fsid_val[0] = 0;
 305
 306         if (blkid_val && (type--) == 0)
 307                 val = blkid_val;
 308         else if (fsid_val[0] && (type--) == 0)
 309                 val = fsid_val;
 310         else
 311                 return 0;
 312
 313         get_uuid(val, uuidlen, uuid);
 314         return 1;
 315 }
 316
 317 /* Iterate through /etc/mtab, finding mountpoints
 318  * at or below a given path
 319  */
 320 static char *next_mnt(void **v, char *p)
 321 {
 322         FILE *f;
 323         struct mntent *me;
 324         int l = strlen(p);
 325         if (*v == NULL) {
 326                 f = setmntent("/etc/mtab", "r");
 327                 *v = f;
 328         } else
 329                 f = *v;
 330         while ((me = getmntent(f)) != NULL &&
 331                (strncmp(me->mnt_dir, p, l) != 0 ||
 332                 me->mnt_dir[l] != '/'))
 333                 ;
 334         if (me == NULL) {
 335                 endmntent(f);
 336                 *v = NULL;
 337                 return NULL;
 338         }
 339         return me->mnt_dir;
 340 }
 341
 342 static void nfsd_fh(FILE *f)
 343 {
 344         /* request are:
 345          *  domain fsidtype fsid
 346          * interpret fsid, find export point and options, and write:
 347          *  domain fsidtype fsid expiry path
 348          */
 349         char *cp;
 350         char *dom;
 351         int fsidtype;
 352         int fsidlen;
 353         unsigned int dev, major=0, minor=0;
 354         unsigned int inode=0;
 355         unsigned long long inode64;
 356         unsigned int fsidnum=0;
 357         char fsid[32];
 358         struct exportent *found = NULL;
 359         struct addrinfo *ai = NULL;
 360         char *found_path = NULL;
 361         nfs_export *exp;
 362         int i;
 363         int dev_missing = 0;
 364         int uuidlen = 0;
 365         char *fhuuid = NULL;
 366
 367         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
 368                 return;
 369
 370         xlog(D_CALL, "nfsd_fh: inbuf '%s'", lbuf);
 371
 372         cp = lbuf;
 373
 374         dom = malloc(strlen(cp));
 375         if (dom == NULL)
 376                 return;
 377         if (qword_get(&cp, dom, strlen(cp)) <= 0)
 378                 goto out;
 379         if (qword_get_int(&cp, &fsidtype) != 0)
 380                 goto out;
 381         if (fsidtype < 0 || fsidtype > 7)
 382                 goto out; /* unknown type */
 383         if ((fsidlen = qword_get(&cp, fsid, 32)) <= 0)
 384                 goto out;
 385         switch(fsidtype) {
 386         case FSID_DEV: /* 4 bytes: 2 major, 2 minor, 4 inode */
 387                 if (fsidlen != 8)
 388                         goto out;
 389                 memcpy(&dev, fsid, 4);
 390                 memcpy(&inode, fsid+4, 4);
 391                 major = ntohl(dev)>>16;
 392                 minor = ntohl(dev) & 0xFFFF;
 393                 break;
 394
 395         case FSID_NUM: /* 4 bytes - fsid */
 396                 if (fsidlen != 4)
 397                         goto out;
 398                 memcpy(&fsidnum, fsid, 4);
 399                 break;
 400
 401         case FSID_MAJOR_MINOR: /* 12 bytes: 4 major, 4 minor, 4 inode
 402                  * This format is never actually used but was
 403                  * an historical accident
 404                  */
 405                 if (fsidlen != 12)
 406                         goto out;
 407                 memcpy(&dev, fsid, 4); major = ntohl(dev);
 408                 memcpy(&dev, fsid+4, 4); minor = ntohl(dev);
 409                 memcpy(&inode, fsid+8, 4);
 410                 break;
 411
 412         case FSID_ENCODE_DEV: /* 8 bytes: 4 byte packed device number, 4 inode */
 413                 /* This is *host* endian, not net-byte-order, because
 414                  * no-one outside this host has any business interpreting it
 415                  */
 416                 if (fsidlen != 8)
 417                         goto out;
 418                 memcpy(&dev, fsid, 4);
 419                 memcpy(&inode, fsid+4, 4);
 420                 major = (dev & 0xfff00) >> 8;
 421                 minor = (dev & 0xff) | ((dev >> 12) & 0xfff00);
 422                 break;
 423
 424         case FSID_UUID4_INUM: /* 4 byte inode number and 4 byte uuid */
 425                 if (fsidlen != 8)
 426                         goto out;
 427                 memcpy(&inode, fsid, 4);
 428                 uuidlen = 4;
 429                 fhuuid = fsid+4;
 430                 break;
 431         case FSID_UUID8: /* 8 byte uuid */
 432                 if (fsidlen != 8)
 433                         goto out;
 434                 uuidlen = 8;
 435                 fhuuid = fsid;
 436                 break;
 437         case FSID_UUID16: /* 16 byte uuid */
 438                 if (fsidlen != 16)
 439                         goto out;
 440                 uuidlen = 16;
 441                 fhuuid = fsid;
 442                 break;
 443         case FSID_UUID16_INUM: /* 8 byte inode number and 16 byte uuid */
 444                 if (fsidlen != 24)
 445                         goto out;
 446                 memcpy(&inode64, fsid, 8);
 447                 inode = inode64;
 448                 uuidlen = 16;
 449                 fhuuid = fsid+8;
 450                 break;
 451         }
 452
 453         auth_reload();
 454
 455         /* Now determine export point for this fsid/domain */
 456         for (i=0 ; i < MCL_MAXTYPES; i++) {
 457                 nfs_export *next_exp;
 458                 for (exp = exportlist[i].p_head; exp; exp = next_exp) {
 459                         struct stat stb;
 460                         char u[16];
 461                         char *path;
 462                         int type;
 463
 464                         if (exp->m_export.e_flags & NFSEXP_CROSSMOUNT) {
 465                                 static nfs_export *prev = NULL;
 466                                 static void *mnt = NULL;
 467
 468                                 if (prev == exp) {
 469                                         /* try a submount */
 470                                         path = next_mnt(&mnt, exp->m_export.e_path);
 471                                         if (!path) {
 472                                                 next_exp = exp->m_next;
 473                                                 prev = NULL;
 474                                                 continue;
 475                                         }
 476                                         next_exp = exp;
 477                                 } else {
 478                                         prev = exp;
 479                                         mnt = NULL;
 480                                         path = exp->m_export.e_path;
 481                                         next_exp = exp;
 482                                 }
 483                         } else {
 484                                 path = exp->m_export.e_path;
 485                                 next_exp = exp->m_next;
 486                         }
 487
 488                         if (!use_ipaddr && !client_member(dom, exp->m_client->m_hostname))
 489                                 continue;
 490                         if (exp->m_export.e_mountpoint &&
 491                             !is_mountpoint(exp->m_export.e_mountpoint[0]?
 492                                            exp->m_export.e_mountpoint:
 493                                            exp->m_export.e_path))
 494                                 dev_missing ++;
 495                         if (stat(path, &stb) != 0)
 496                                 continue;
 497                         if (!S_ISDIR(stb.st_mode) && !S_ISREG(stb.st_mode)) {
 498                                 continue;
 499                         }
 500                         switch(fsidtype){
 501                         case FSID_DEV:
 502                         case FSID_MAJOR_MINOR:
 503                         case FSID_ENCODE_DEV:
 504                                 if (stb.st_ino != inode)
 505                                         continue;
 506                                 if (major != major(stb.st_dev) ||
 507                                     minor != minor(stb.st_dev))
 508                                         continue;
 509                                 break;
 510                         case FSID_NUM:
 511                                 if (((exp->m_export.e_flags & NFSEXP_FSID) == 0 ||
 512                                      exp->m_export.e_fsid != fsidnum))
 513                                         continue;
 514                                 break;
 515                         case FSID_UUID4_INUM:
 516                         case FSID_UUID16_INUM:
 517                                 if (stb.st_ino != inode)
 518                                         continue;
 519                                 goto check_uuid;
 520                         case FSID_UUID8:
 521                         case FSID_UUID16:
 522                                 if (!is_mountpoint(path))
 523                                         continue;
 524                         check_uuid:
 525                                 if (exp->m_export.e_uuid)
 526                                         get_uuid(exp->m_export.e_uuid,
 527                                                  uuidlen, u);
 528                                 else
 529                                         for (type = 0;
 530                                              uuid_by_path(path, type, uuidlen, u);
 531                                              type++)
 532                                                 if (memcmp(u, fhuuid, uuidlen) == 0)
 533                                                         break;
 534
 535                                 if (memcmp(u, fhuuid, uuidlen) != 0)
 536                                         continue;
 537                                 break;
 538                         }
 539                         if (use_ipaddr) {
 540                                 if (ai == NULL) {
 541                                         struct addrinfo *tmp;
 542                                         tmp = host_pton(dom);
 543                                         if (tmp == NULL)
 544                                                 goto out;
 545                                         ai = client_resolve(tmp->ai_addr);
 546                                         freeaddrinfo(tmp);
 547                                 }
 548                                 if (!client_check(exp->m_client, ai))
 549                                         continue;
 550                         }
 551                         /* It's a match !! */
 552                         if (!found) {
 553                                 found = &exp->m_export;
 554                                 found_path = strdup(path);
 555                                 if (found_path == NULL)
 556                                         goto out;
 557                         } else if (strcmp(found->e_path, exp->m_export.e_path)!= 0)
 558                         {
 559                                 xlog(L_WARNING, "%s and %s have same filehandle for %s, using first",
 560                                      found_path, path, dom);
 561                         }
 562                 }
 563         }
 564         if (found &&
 565             found->e_mountpoint &&
 566             !is_mountpoint(found->e_mountpoint[0]?
 567                            found->e_mountpoint:
 568                            found->e_path)) {
 569                 /* Cannot export this yet
 570                  * should log a warning, but need to rate limit
 571                    xlog(L_WARNING, "%s not exported as %d not a mountpoint",
 572                    found->e_path, found->e_mountpoint);
 573                  */
 574                 /* FIXME we need to make sure we re-visit this later */
 575                 goto out;
 576         }
 577         if (!found && dev_missing) {
 578                 /* The missing dev could be what we want, so just be
 579                  * quite rather than returning stale yet
 580                  */
 581                 goto out;
 582         }
 583
 584         if (found)
 585                 if (cache_export_ent(dom, found, found_path) < 0)
 586                         found = 0;
 587
 588         qword_print(f, dom);
 589         qword_printint(f, fsidtype);
 590         qword_printhex(f, fsid, fsidlen);
 591         /* The fsid -> path lookup can be quite expensive as it
 592          * potentially stats and reads lots of devices, and some of those
 593          * might have spun-down.  The Answer is not likely to
 594          * change underneath us, and an 'exportfs -f' can always
 595          * remove this from the kernel, so use a really log
 596          * timeout.  Maybe this should be configurable on the command
 597          * line.
 598          */
 599         qword_printint(f, 0x7fffffff);
 600         if (found)
 601                 qword_print(f, found_path);
 602         qword_eol(f);
 603  out:
 604         if (found_path)
 605                 free(found_path);
 606         freeaddrinfo(ai);
 607         free(dom);
 608         xlog(D_CALL, "nfsd_fh: found %p path %s", found, found ? found->e_path : NULL);
 609         return;
 610 }
 611
 612 static void write_fsloc(FILE *f, struct exportent *ep)
 613 {
 614         struct servers *servers;
 615
 616         if (ep->e_fslocmethod == FSLOC_NONE)
 617                 return;
 618
 619         servers = replicas_lookup(ep->e_fslocmethod, ep->e_fslocdata);
 620         if (!servers)
 621                 return;
 622         qword_print(f, "fsloc");
 623         qword_printint(f, servers->h_num);
 624         if (servers->h_num >= 0) {
 625                 int i;
 626                 for (i=0; i<servers->h_num; i++) {
 627                         qword_print(f, servers->h_mp[i]->h_host);
 628                         qword_print(f, servers->h_mp[i]->h_path);
 629                 }
 630         }
 631         qword_printint(f, servers->h_referral);
 632         release_replicas(servers);
 633 }
 634
 635 static void write_secinfo(FILE *f, struct exportent *ep, int flag_mask)
 636 {
 637         struct sec_entry *p;
 638
 639         for (p = ep->e_secinfo; p->flav; p++)
 640                 ; /* Do nothing */
 641         if (p == ep->e_secinfo) {
 642                 /* There was no sec= option */
 643                 return;
 644         }
 645         qword_print(f, "secinfo");
 646         qword_printint(f, p - ep->e_secinfo);
 647         for (p = ep->e_secinfo; p->flav; p++) {
 648                 qword_printint(f, p->flav->fnum);
 649                 qword_printint(f, p->flags & flag_mask);
 650         }
 651
 652 }
 653
 654 static int dump_to_cache(FILE *f, char *domain, char *path, struct exportent *exp)
 655 {
 656         qword_print(f, domain);
 657         qword_print(f, path);
 658         if (exp) {
 659                 int different_fs = strcmp(path, exp->e_path) != 0;
 660                 int flag_mask = different_fs ? ~NFSEXP_FSID : ~0;
 661
 662                 qword_printuint(f, time(0) + exp->e_ttl);
 663                 qword_printint(f, exp->e_flags & flag_mask);
 664                 qword_printint(f, exp->e_anonuid);
 665                 qword_printint(f, exp->e_anongid);
 666                 qword_printint(f, exp->e_fsid);
 667                 write_fsloc(f, exp);
 668                 write_secinfo(f, exp, flag_mask);
 669                 if (exp->e_uuid == NULL || different_fs) {
 670                         char u[16];
 671                         if (uuid_by_path(path, 0, 16, u)) {
 672                                 qword_print(f, "uuid");
 673                                 qword_printhex(f, u, 16);
 674                         }
 675                 } else {
 676                         char u[16];
 677                         get_uuid(exp->e_uuid, 16, u);
 678                         qword_print(f, "uuid");
 679                         qword_printhex(f, u, 16);
 680                 }
 681         } else
 682                 qword_printuint(f, time(0) + DEFAULT_TTL);
 683         return qword_eol(f);
 684 }
 685
 686 static int is_subdirectory(char *child, char *parent)
 687 {
 688         int l = strlen(parent);
 689
 690         return strcmp(child, parent) == 0
 691                 || (strncmp(child, parent, l) == 0 && child[l] == '/');
 692 }
 693
 694 static int path_matches(nfs_export *exp, char *path)
 695 {
 696         if (exp->m_export.e_flags & NFSEXP_CROSSMOUNT)
 697                 return is_subdirectory(path, exp->m_export.e_path);
 698         return strcmp(path, exp->m_export.e_path) == 0;
 699 }
 700
 701 static int
 702 client_matches(nfs_export *exp, char *dom, struct addrinfo *ai)
 703 {
 704         if (use_ipaddr)
 705                 return client_check(exp->m_client, ai);
 706         return client_member(dom, exp->m_client->m_hostname);
 707 }
 708
 709 static int
 710 export_matches(nfs_export *exp, char *dom, char *path, struct addrinfo *ai)
 711 {
 712         return path_matches(exp, path) && client_matches(exp, dom, ai);
 713 }
 714
 715 static nfs_export *
 716 lookup_export(char *dom, char *path, struct addrinfo *ai)
 717 {
 718         nfs_export *exp;
 719         nfs_export *found = NULL;
 720         int found_type = 0;
 721         int i;
 722
 723         for (i=0 ; i < MCL_MAXTYPES; i++) {
 724                 for (exp = exportlist[i].p_head; exp; exp = exp->m_next) {
 725                         if (!export_matches(exp, dom, path, ai))
 726                                 continue;
 727                         if (!found) {
 728                                 found = exp;
 729                                 found_type = i;
 730                                 continue;
 731                         }
 732
 733                         /* Always prefer non-V4ROOT mounts */
 734                         if (found->m_export.e_flags & NFSEXP_V4ROOT)
 735                                 continue;
 736
 737                         /* If one is a CROSSMOUNT, then prefer the longest path */
 738                         if (((found->m_export.e_flags & NFSEXP_CROSSMOUNT) ||
 739                              (exp->m_export.e_flags & NFSEXP_CROSSMOUNT)) &&
 740                             strlen(found->m_export.e_path) !=
 741                             strlen(exp->m_export.e_path)) {
 742
 743                                 if (strlen(exp->m_export.e_path) >
 744                                     strlen(found->m_export.e_path)) {
 745                                         found = exp;
 746                                         found_type = i;
 747                                 }
 748                                 continue;
 749
 750                         } else if (found_type == i && found->m_warned == 0) {
 751                                 xlog(L_WARNING, "%s exported to both %s and %s, "
 752                                      "arbitrarily choosing options from first",
 753                                      path, found->m_client->m_hostname, exp->m_client->m_hostname,
 754                                      dom);
 755                                 found->m_warned = 1;
 756                         }
 757                 }
 758         }
 759         return found;
 760 }
 761
 762 static void nfsd_export(FILE *f)
 763 {
 764         /* requests are:
 765          *  domain path
 766          * determine export options and return:
 767          *  domain path expiry flags anonuid anongid fsid
 768          */
 769
 770         char *cp;
 771         char *dom, *path;
 772         nfs_export *found = NULL;
 773         struct addrinfo *ai = NULL;
 774
 775         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
 776                 return;
 777
 778         xlog(D_CALL, "nfsd_export: inbuf '%s'", lbuf);
 779
 780         cp = lbuf;
 781         dom = malloc(strlen(cp));
 782         path = malloc(strlen(cp));
 783
 784         if (!dom || !path)
 785                 goto out;
 786
 787         if (qword_get(&cp, dom, strlen(lbuf)) <= 0)
 788                 goto out;
 789         if (qword_get(&cp, path, strlen(lbuf)) <= 0)
 790                 goto out;
 791
 792         auth_reload();
 793
 794         if (use_ipaddr) {
 795                 struct addrinfo *tmp;
 796                 tmp = host_pton(dom);
 797                 if (tmp == NULL)
 798                         goto out;
 799                 ai = client_resolve(tmp->ai_addr);
 800                 freeaddrinfo(tmp);
 801                         goto out;
 802         }
 803
 804         found = lookup_export(dom, path, ai);
 805
 806         if (found) {
 807                 if (dump_to_cache(f, dom, path, &found->m_export) < 0) {
 808                         xlog(L_WARNING,
 809                              "Cannot export %s, possibly unsupported filesystem"
 810                              " or fsid= required", path);
 811                         dump_to_cache(f, dom, path, NULL);
 812                 }
 813         } else {
 814                 dump_to_cache(f, dom, path, NULL);
 815         }
 816  out:
 817         xlog(D_CALL, "nfsd_export: found %p path %s", found, path ? path : NULL);
 818         if (dom) free(dom);
 819         if (path) free(path);
 820         freeaddrinfo(ai);
 821 }
 822
 823
 824 struct {
 825         char *cache_name;
 826         void (*cache_handle)(FILE *f);
 827         FILE *f;
 828         char vbuf[RPC_CHAN_BUF_SIZE];
 829 } cachelist[] = {
 830         { "auth.unix.ip", auth_unix_ip, NULL},
 831         { "auth.unix.gid", auth_unix_gid, NULL},
 832         { "nfsd.export", nfsd_export, NULL},
 833         { "nfsd.fh", nfsd_fh, NULL},
 834         { NULL, NULL, NULL }
 835 };
 836
 837 extern int manage_gids;
 838
 839 /**
 840  * cache_open - prepare communications channels with kernel RPC caches
 841  *
 842  */
 843 void cache_open(void)
 844 {
 845         int i;
 846         for (i=0; cachelist[i].cache_name; i++ ) {
 847                 char path[100];
 848                 if (!manage_gids && cachelist[i].cache_handle == auth_unix_gid)
 849                         continue;
 850                 sprintf(path, "/proc/net/rpc/%s/channel", cachelist[i].cache_name);
 851                 cachelist[i].f = fopen(path, "r+");
 852                 if (cachelist[i].f != NULL) {
 853                         setvbuf(cachelist[i].f, cachelist[i].vbuf, _IOLBF,
 854                                 RPC_CHAN_BUF_SIZE);
 855                 }
 856         }
 857 }
 858
 859 /**
 860  * cache_set_fds - prepare cache file descriptors for one iteration of the service loop
 861  * @fdset: pointer to fd_set to prepare
 862  */
 863 void cache_set_fds(fd_set *fdset)
 864 {
 865         int i;
 866         for (i=0; cachelist[i].cache_name; i++) {
 867                 if (cachelist[i].f)
 868                         FD_SET(fileno(cachelist[i].f), fdset);
 869         }
 870 }
 871
 872 /**
 873  * cache_process_req - process any active cache file descriptors during service loop iteration
 874  * @fdset: pointer to fd_set to examine for activity
 875  */
 876 int cache_process_req(fd_set *readfds)
 877 {
 878         int i;
 879         int cnt = 0;
 880         for (i=0; cachelist[i].cache_name; i++) {
 881                 if (cachelist[i].f != NULL &&
 882                     FD_ISSET(fileno(cachelist[i].f), readfds)) {
 883                         cnt++;
 884                         cachelist[i].cache_handle(cachelist[i].f);
 885                         FD_CLR(fileno(cachelist[i].f), readfds);
 886                 }
 887         }
 888         return cnt;
 889 }
 890
 891
 892 /*
 893  * Give IP->domain and domain+path->options to kernel
 894  * % echo nfsd $IP  $[now+DEFAULT_TTL] $domain > /proc/net/rpc/auth.unix.ip/channel
 895  * % echo $domain $path $[now+DEFAULT_TTL] $options $anonuid $anongid $fsid > /proc/net/rpc/nfsd.export/channel
 896  */
 897
 898 static int cache_export_ent(char *domain, struct exportent *exp, char *path)
 899 {
 900         int err;
 901         FILE *f = fopen("/proc/net/rpc/nfsd.export/channel", "w");
 902         if (!f)
 903                 return -1;
 904
 905         err = dump_to_cache(f, domain, exp->e_path, exp);
 906         if (err) {
 907                 xlog(L_WARNING,
 908                      "Cannot export %s, possibly unsupported filesystem or"
 909                      " fsid= required", exp->e_path);
 910         }
 911
 912         while (err == 0 && (exp->e_flags & NFSEXP_CROSSMOUNT) && path) {
 913                 /* really an 'if', but we can break out of
 914                  * a 'while' more easily */
 915                 /* Look along 'path' for other filesystems
 916                  * and export them with the same options
 917                  */
 918                 struct stat stb;
 919                 size_t l = strlen(exp->e_path);
 920                 __dev_t dev;
 921
 922                 if (strlen(path) <= l || path[l] != '/' ||
 923                     strncmp(exp->e_path, path, l) != 0)
 924                         break;
 925                 if (stat(exp->e_path, &stb) != 0)
 926                         break;
 927                 dev = stb.st_dev;
 928                 while(path[l] == '/') {
 929                         char c;
 930                         /* errors for submount should fail whole filesystem */
 931                         int err2;
 932
 933                         l++;
 934                         while (path[l] != '/' && path[l])
 935                                 l++;
 936                         c = path[l];
 937                         path[l] = 0;
 938                         err2 = lstat(path, &stb);
 939                         path[l] = c;
 940                         if (err2 < 0)
 941                                 break;
 942                         if (stb.st_dev == dev)
 943                                 continue;
 944                         dev = stb.st_dev;
 945                         path[l] = 0;
 946                         dump_to_cache(f, domain, path, exp);
 947                         path[l] = c;
 948                 }
 949                 break;
 950         }
 951
 952         fclose(f);
 953         return err;
 954 }
 955
 956 /**
 957  * cache_export - Inform kernel of a new nfs_export
 958  * @exp: target nfs_export
 959  * @path: NUL-terminated C string containing export path
 960  */
 961 int cache_export(nfs_export *exp, char *path)
 962 {
 963         char buf[INET6_ADDRSTRLEN];
 964         int err;
 965         FILE *f;
 966
 967         f = fopen("/proc/net/rpc/auth.unix.ip/channel", "w");
 968         if (!f)
 969                 return -1;
 970
 971
 972         qword_print(f, "nfsd");
 973         qword_print(f,
 974                 host_ntop(get_addrlist(exp->m_client, 0), buf, sizeof(buf)));
 975         qword_printuint(f, time(0) + exp->m_export.e_ttl);
 976         qword_print(f, exp->m_client->m_hostname);
 977         err = qword_eol(f);
 978
 979         fclose(f);
 980
 981         err = cache_export_ent(exp->m_client->m_hostname, &exp->m_export, path)
 982                 || err;
 983         return err;
 984 }
 985
 986 /**
 987  * cache_get_filehandle - given an nfs_export, get its root filehandle
 988  * @exp: target nfs_export
 989  * @len: length of requested file handle
 990  * @p: NUL-terminated C string containing export path
 991  *
 992  * Returns pointer to NFS file handle of root directory of export
 993  *
 994  * {
 995  *   echo $domain $path $length
 996  *   read filehandle <&0
 997  * } <> /proc/fs/nfsd/filehandle
 998  */
 999 struct nfs_fh_len *
1000 cache_get_filehandle(nfs_export *exp, int len, char *p)
1001 {
1002         FILE *f = fopen("/proc/fs/nfsd/filehandle", "r+");
1003         char buf[200];
1004         char *bp = buf;
1005         int failed;
1006         static struct nfs_fh_len fh;
1007
1008         if (!f)
1009                 f = fopen("/proc/fs/nfs/filehandle", "r+");
1010         if (!f)
1011                 return NULL;
1012
1013         qword_print(f, exp->m_client->m_hostname);
1014         qword_print(f, p);
1015         qword_printint(f, len);
1016         failed = qword_eol(f);
1017
1018         if (!failed)
1019                 failed = (fgets(buf, sizeof(buf), f) == NULL);
1020         fclose(f);
1021         if (failed)
1022                 return NULL;
1023         memset(fh.fh_handle, 0, sizeof(fh.fh_handle));
1024         fh.fh_size = qword_get(&bp, (char *)fh.fh_handle, NFS3_FHSIZE);
1025         return &fh;
1026 }