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;
 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 = INITIAL_MANAGED_GROUPS;
 151         }
 152
 153         ngroups = groups_len;
 154
 155         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
 156                 return;
 157
 158         cp = lbuf;
 159         if (qword_get_uint(&cp, &uid) != 0)
 160                 return;
 161
 162         pw = getpwuid(uid);
 163         if (!pw)
 164                 rv = -1;
 165         else {
 166                 rv = getgrouplist(pw->pw_name, pw->pw_gid, groups, &ngroups);
 167                 if (rv == -1 && ngroups >= groups_len) {
 168                         more_groups = realloc(groups, sizeof(gid_t)*ngroups);
 169                         if (!more_groups)
 170                                 rv = -1;
 171                         else {
 172                                 groups = more_groups;
 173                                 groups_len = ngroups;
 174                                 rv = getgrouplist(pw->pw_name, pw->pw_gid,
 175                                                   groups, &ngroups);
 176                         }
 177                 }
 178         }
 179         qword_printuint(f, uid);
 180         qword_printuint(f, time(0) + DEFAULT_TTL);
 181         if (rv >= 0) {
 182                 qword_printuint(f, ngroups);
 183                 for (i=0; i<ngroups; i++)
 184                         qword_printuint(f, groups[i]);
 185         } else
 186                 qword_printuint(f, 0);
 187         qword_eol(f);
 188 }
 189
 190 #if USE_BLKID
 191 static const char *get_uuid_blkdev(char *path)
 192 {
 193         /* We set *safe if we know that we need the
 194          * fsid from statfs too.
 195          */
 196         static blkid_cache cache = NULL;
 197         struct stat stb;
 198         char *devname;
 199         blkid_tag_iterate iter;
 200         blkid_dev dev;
 201         const char *type;
 202         const char *val, *uuid = NULL;
 203
 204         if (cache == NULL)
 205                 blkid_get_cache(&cache, NULL);
 206
 207         if (stat(path, &stb) != 0)
 208                 return NULL;
 209         devname = blkid_devno_to_devname(stb.st_dev);
 210         if (!devname)
 211                 return NULL;
 212         dev = blkid_get_dev(cache, devname, BLKID_DEV_NORMAL);
 213         free(devname);
 214         if (!dev)
 215                 return NULL;
 216         iter = blkid_tag_iterate_begin(dev);
 217         if (!iter)
 218                 return NULL;
 219         while (blkid_tag_next(iter, &type, &val) == 0) {
 220                 if (strcmp(type, "UUID") == 0)
 221                         uuid = val;
 222                 if (strcmp(type, "TYPE") == 0 &&
 223                     strcmp(val, "btrfs") == 0) {
 224                         uuid = NULL;
 225                         break;
 226                 }
 227         }
 228         blkid_tag_iterate_end(iter);
 229         return uuid;
 230 }
 231 #else
 232 #define get_uuid_blkdev(path) (NULL)
 233 #endif
 234
 235 static int get_uuid(const char *val, int uuidlen, char *u)
 236 {
 237         /* extract hex digits from uuidstr and compose a uuid
 238          * of the given length (max 16), xoring bytes to make
 239          * a smaller uuid.
 240          */
 241         int i = 0;
 242
 243         memset(u, 0, uuidlen);
 244         for ( ; *val ; val++) {
 245                 char c = *val;
 246                 if (!isxdigit(c))
 247                         continue;
 248                 if (isalpha(c)) {
 249                         if (isupper(c))
 250                                 c = c - 'A' + 10;
 251                         else
 252                                 c = c - 'a' + 10;
 253                 } else
 254                         c = c - '0' + 0;
 255                 if ((i&1) == 0)
 256                         c <<= 4;
 257                 u[i/2] ^= c;
 258                 i++;
 259                 if (i == uuidlen*2)
 260                         i = 0;
 261         }
 262         return 1;
 263 }
 264
 265 static int uuid_by_path(char *path, int type, int uuidlen, char *uuid)
 266 {
 267         /* get a uuid for the filesystem found at 'path'.
 268          * There are several possible ways of generating the
 269          * uuids (types).
 270          * Type 0 is used for new filehandles, while other types
 271          * may be used to interpret old filehandle - to ensure smooth
 272          * forward migration.
 273          * We return 1 if a uuid was found (and it might be worth
 274          * trying the next type) or 0 if no more uuid types can be
 275          * extracted.
 276          */
 277
 278         /* Possible sources of uuid are
 279          * - blkid uuid
 280          * - statfs64 uuid
 281          *
 282          * On some filesystems (e.g. vfat) the statfs64 uuid is simply an
 283          * encoding of the device that the filesystem is mounted from, so
 284          * it we be very bad to use that (as device numbers change).  blkid
 285          * must be preferred.
 286          * On other filesystems (e.g. btrfs) the statfs64 uuid contains
 287          * important info that the blkid uuid cannot contain:  This happens
 288          * when multiple subvolumes are exported (they have the same
 289          * blkid uuid but different statfs64 uuids).
 290          * We rely on get_uuid_blkdev *knowing* which is which and not returning
 291          * a uuid for filesystems where the statfs64 uuid is better.
 292          *
 293          */
 294         struct statfs64 st;
 295         char fsid_val[17];
 296         const char *blkid_val;
 297         const char *val;
 298
 299         blkid_val = get_uuid_blkdev(path);
 300
 301         if (statfs64(path, &st) == 0 &&
 302             (st.f_fsid.__val[0] || st.f_fsid.__val[1]))
 303                 snprintf(fsid_val, 17, "%08x%08x",
 304                          st.f_fsid.__val[0], st.f_fsid.__val[1]);
 305         else
 306                 fsid_val[0] = 0;
 307
 308         if (blkid_val && (type--) == 0)
 309                 val = blkid_val;
 310         else if (fsid_val[0] && (type--) == 0)
 311                 val = fsid_val;
 312         else
 313                 return 0;
 314
 315         get_uuid(val, uuidlen, uuid);
 316         return 1;
 317 }
 318
 319 /* Iterate through /etc/mtab, finding mountpoints
 320  * at or below a given path
 321  */
 322 static char *next_mnt(void **v, char *p)
 323 {
 324         FILE *f;
 325         struct mntent *me;
 326         int l = strlen(p);
 327         if (*v == NULL) {
 328                 f = setmntent("/etc/mtab", "r");
 329                 *v = f;
 330         } else
 331                 f = *v;
 332         while ((me = getmntent(f)) != NULL &&
 333                (strncmp(me->mnt_dir, p, l) != 0 ||
 334                 me->mnt_dir[l] != '/'))
 335                 ;
 336         if (me == NULL) {
 337                 endmntent(f);
 338                 *v = NULL;
 339                 return NULL;
 340         }
 341         return me->mnt_dir;
 342 }
 343
 344 static void nfsd_fh(FILE *f)
 345 {
 346         /* request are:
 347          *  domain fsidtype fsid
 348          * interpret fsid, find export point and options, and write:
 349          *  domain fsidtype fsid expiry path
 350          */
 351         char *cp;
 352         char *dom;
 353         int fsidtype;
 354         int fsidlen;
 355         unsigned int dev, major=0, minor=0;
 356         unsigned int inode=0;
 357         unsigned long long inode64;
 358         unsigned int fsidnum=0;
 359         char fsid[32];
 360         struct exportent *found = NULL;
 361         struct addrinfo *ai = NULL;
 362         char *found_path = NULL;
 363         nfs_export *exp;
 364         int i;
 365         int dev_missing = 0;
 366         int uuidlen = 0;
 367         char *fhuuid = NULL;
 368
 369         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
 370                 return;
 371
 372         xlog(D_CALL, "nfsd_fh: inbuf '%s'", lbuf);
 373
 374         cp = lbuf;
 375
 376         dom = malloc(strlen(cp));
 377         if (dom == NULL)
 378                 return;
 379         if (qword_get(&cp, dom, strlen(cp)) <= 0)
 380                 goto out;
 381         if (qword_get_int(&cp, &fsidtype) != 0)
 382                 goto out;
 383         if (fsidtype < 0 || fsidtype > 7)
 384                 goto out; /* unknown type */
 385         if ((fsidlen = qword_get(&cp, fsid, 32)) <= 0)
 386                 goto out;
 387         switch(fsidtype) {
 388         case FSID_DEV: /* 4 bytes: 2 major, 2 minor, 4 inode */
 389                 if (fsidlen != 8)
 390                         goto out;
 391                 memcpy(&dev, fsid, 4);
 392                 memcpy(&inode, fsid+4, 4);
 393                 major = ntohl(dev)>>16;
 394                 minor = ntohl(dev) & 0xFFFF;
 395                 break;
 396
 397         case FSID_NUM: /* 4 bytes - fsid */
 398                 if (fsidlen != 4)
 399                         goto out;
 400                 memcpy(&fsidnum, fsid, 4);
 401                 break;
 402
 403         case FSID_MAJOR_MINOR: /* 12 bytes: 4 major, 4 minor, 4 inode
 404                  * This format is never actually used but was
 405                  * an historical accident
 406                  */
 407                 if (fsidlen != 12)
 408                         goto out;
 409                 memcpy(&dev, fsid, 4); major = ntohl(dev);
 410                 memcpy(&dev, fsid+4, 4); minor = ntohl(dev);
 411                 memcpy(&inode, fsid+8, 4);
 412                 break;
 413
 414         case FSID_ENCODE_DEV: /* 8 bytes: 4 byte packed device number, 4 inode */
 415                 /* This is *host* endian, not net-byte-order, because
 416                  * no-one outside this host has any business interpreting it
 417                  */
 418                 if (fsidlen != 8)
 419                         goto out;
 420                 memcpy(&dev, fsid, 4);
 421                 memcpy(&inode, fsid+4, 4);
 422                 major = (dev & 0xfff00) >> 8;
 423                 minor = (dev & 0xff) | ((dev >> 12) & 0xfff00);
 424                 break;
 425
 426         case FSID_UUID4_INUM: /* 4 byte inode number and 4 byte uuid */
 427                 if (fsidlen != 8)
 428                         goto out;
 429                 memcpy(&inode, fsid, 4);
 430                 uuidlen = 4;
 431                 fhuuid = fsid+4;
 432                 break;
 433         case FSID_UUID8: /* 8 byte uuid */
 434                 if (fsidlen != 8)
 435                         goto out;
 436                 uuidlen = 8;
 437                 fhuuid = fsid;
 438                 break;
 439         case FSID_UUID16: /* 16 byte uuid */
 440                 if (fsidlen != 16)
 441                         goto out;
 442                 uuidlen = 16;
 443                 fhuuid = fsid;
 444                 break;
 445         case FSID_UUID16_INUM: /* 8 byte inode number and 16 byte uuid */
 446                 if (fsidlen != 24)
 447                         goto out;
 448                 memcpy(&inode64, fsid, 8);
 449                 inode = inode64;
 450                 uuidlen = 16;
 451                 fhuuid = fsid+8;
 452                 break;
 453         }
 454
 455         auth_reload();
 456
 457         /* Now determine export point for this fsid/domain */
 458         for (i=0 ; i < MCL_MAXTYPES; i++) {
 459                 nfs_export *next_exp;
 460                 for (exp = exportlist[i].p_head; exp; exp = next_exp) {
 461                         struct stat stb;
 462                         char u[16];
 463                         char *path;
 464                         int type;
 465
 466                         if (exp->m_export.e_flags & NFSEXP_CROSSMOUNT) {
 467                                 static nfs_export *prev = NULL;
 468                                 static void *mnt = NULL;
 469
 470                                 if (prev == exp) {
 471                                         /* try a submount */
 472                                         path = next_mnt(&mnt, exp->m_export.e_path);
 473                                         if (!path) {
 474                                                 next_exp = exp->m_next;
 475                                                 prev = NULL;
 476                                                 continue;
 477                                         }
 478                                         next_exp = exp;
 479                                 } else {
 480                                         prev = exp;
 481                                         mnt = NULL;
 482                                         path = exp->m_export.e_path;
 483                                         next_exp = exp;
 484                                 }
 485                         } else {
 486                                 path = exp->m_export.e_path;
 487                                 next_exp = exp->m_next;
 488                         }
 489
 490                         if (!use_ipaddr && !client_member(dom, exp->m_client->m_hostname))
 491                                 continue;
 492                         if (exp->m_export.e_mountpoint &&
 493                             !is_mountpoint(exp->m_export.e_mountpoint[0]?
 494                                            exp->m_export.e_mountpoint:
 495                                            exp->m_export.e_path))
 496                                 dev_missing ++;
 497                         if (stat(path, &stb) != 0)
 498                                 continue;
 499                         if (!S_ISDIR(stb.st_mode) && !S_ISREG(stb.st_mode)) {
 500                                 continue;
 501                         }
 502                         switch(fsidtype){
 503                         case FSID_DEV:
 504                         case FSID_MAJOR_MINOR:
 505                         case FSID_ENCODE_DEV:
 506                                 if (stb.st_ino != inode)
 507                                         continue;
 508                                 if (major != major(stb.st_dev) ||
 509                                     minor != minor(stb.st_dev))
 510                                         continue;
 511                                 break;
 512                         case FSID_NUM:
 513                                 if (((exp->m_export.e_flags & NFSEXP_FSID) == 0 ||
 514                                      exp->m_export.e_fsid != fsidnum))
 515                                         continue;
 516                                 break;
 517                         case FSID_UUID4_INUM:
 518                         case FSID_UUID16_INUM:
 519                                 if (stb.st_ino != inode)
 520                                         continue;
 521                                 goto check_uuid;
 522                         case FSID_UUID8:
 523                         case FSID_UUID16:
 524                                 if (!is_mountpoint(path))
 525                                         continue;
 526                         check_uuid:
 527                                 if (exp->m_export.e_uuid)
 528                                         get_uuid(exp->m_export.e_uuid,
 529                                                  uuidlen, u);
 530                                 else
 531                                         for (type = 0;
 532                                              uuid_by_path(path, type, uuidlen, u);
 533                                              type++)
 534                                                 if (memcmp(u, fhuuid, uuidlen) == 0)
 535                                                         break;
 536
 537                                 if (memcmp(u, fhuuid, uuidlen) != 0)
 538                                         continue;
 539                                 break;
 540                         }
 541                         if (use_ipaddr) {
 542                                 if (ai == NULL) {
 543                                         struct addrinfo *tmp;
 544                                         tmp = host_pton(dom);
 545                                         if (tmp == NULL)
 546                                                 goto out;
 547                                         ai = client_resolve(tmp->ai_addr);
 548                                         freeaddrinfo(tmp);
 549                                 }
 550                                 if (!client_check(exp->m_client, ai))
 551                                         continue;
 552                         }
 553                         /* It's a match !! */
 554                         if (!found) {
 555                                 found = &exp->m_export;
 556                                 found_path = strdup(path);
 557                                 if (found_path == NULL)
 558                                         goto out;
 559                         } else if (strcmp(found->e_path, exp->m_export.e_path)!= 0)
 560                         {
 561                                 xlog(L_WARNING, "%s and %s have same filehandle for %s, using first",
 562                                      found_path, path, dom);
 563                         }
 564                 }
 565         }
 566         if (found &&
 567             found->e_mountpoint &&
 568             !is_mountpoint(found->e_mountpoint[0]?
 569                            found->e_mountpoint:
 570                            found->e_path)) {
 571                 /* Cannot export this yet
 572                  * should log a warning, but need to rate limit
 573                    xlog(L_WARNING, "%s not exported as %d not a mountpoint",
 574                    found->e_path, found->e_mountpoint);
 575                  */
 576                 /* FIXME we need to make sure we re-visit this later */
 577                 goto out;
 578         }
 579         if (!found && dev_missing) {
 580                 /* The missing dev could be what we want, so just be
 581                  * quite rather than returning stale yet
 582                  */
 583                 goto out;
 584         }
 585
 586         if (found)
 587                 if (cache_export_ent(dom, found, found_path) < 0)
 588                         found = 0;
 589
 590         qword_print(f, dom);
 591         qword_printint(f, fsidtype);
 592         qword_printhex(f, fsid, fsidlen);
 593         /* The fsid -> path lookup can be quite expensive as it
 594          * potentially stats and reads lots of devices, and some of those
 595          * might have spun-down.  The Answer is not likely to
 596          * change underneath us, and an 'exportfs -f' can always
 597          * remove this from the kernel, so use a really log
 598          * timeout.  Maybe this should be configurable on the command
 599          * line.
 600          */
 601         qword_printint(f, 0x7fffffff);
 602         if (found)
 603                 qword_print(f, found_path);
 604         qword_eol(f);
 605  out:
 606         if (found_path)
 607                 free(found_path);
 608         freeaddrinfo(ai);
 609         free(dom);
 610         xlog(D_CALL, "nfsd_fh: found %p path %s", found, found ? found->e_path : NULL);
 611         return;
 612 }
 613
 614 static void write_fsloc(FILE *f, struct exportent *ep)
 615 {
 616         struct servers *servers;
 617
 618         if (ep->e_fslocmethod == FSLOC_NONE)
 619                 return;
 620
 621         servers = replicas_lookup(ep->e_fslocmethod, ep->e_fslocdata);
 622         if (!servers)
 623                 return;
 624         qword_print(f, "fsloc");
 625         qword_printint(f, servers->h_num);
 626         if (servers->h_num >= 0) {
 627                 int i;
 628                 for (i=0; i<servers->h_num; i++) {
 629                         qword_print(f, servers->h_mp[i]->h_host);
 630                         qword_print(f, servers->h_mp[i]->h_path);
 631                 }
 632         }
 633         qword_printint(f, servers->h_referral);
 634         release_replicas(servers);
 635 }
 636
 637 static void write_secinfo(FILE *f, struct exportent *ep, int flag_mask)
 638 {
 639         struct sec_entry *p;
 640
 641         for (p = ep->e_secinfo; p->flav; p++)
 642                 ; /* Do nothing */
 643         if (p == ep->e_secinfo) {
 644                 /* There was no sec= option */
 645                 return;
 646         }
 647         qword_print(f, "secinfo");
 648         qword_printint(f, p - ep->e_secinfo);
 649         for (p = ep->e_secinfo; p->flav; p++) {
 650                 qword_printint(f, p->flav->fnum);
 651                 qword_printint(f, p->flags & flag_mask);
 652         }
 653
 654 }
 655
 656 static int dump_to_cache(FILE *f, char *domain, char *path, struct exportent *exp)
 657 {
 658         qword_print(f, domain);
 659         qword_print(f, path);
 660         if (exp) {
 661                 int different_fs = strcmp(path, exp->e_path) != 0;
 662                 int flag_mask = different_fs ? ~NFSEXP_FSID : ~0;
 663
 664                 qword_printuint(f, time(0) + exp->e_ttl);
 665                 qword_printint(f, exp->e_flags & flag_mask);
 666                 qword_printint(f, exp->e_anonuid);
 667                 qword_printint(f, exp->e_anongid);
 668                 qword_printint(f, exp->e_fsid);
 669                 write_fsloc(f, exp);
 670                 write_secinfo(f, exp, flag_mask);
 671                 if (exp->e_uuid == NULL || different_fs) {
 672                         char u[16];
 673                         if (uuid_by_path(path, 0, 16, u)) {
 674                                 qword_print(f, "uuid");
 675                                 qword_printhex(f, u, 16);
 676                         }
 677                 } else {
 678                         char u[16];
 679                         get_uuid(exp->e_uuid, 16, u);
 680                         qword_print(f, "uuid");
 681                         qword_printhex(f, u, 16);
 682                 }
 683         } else
 684                 qword_printuint(f, time(0) + DEFAULT_TTL);
 685         return qword_eol(f);
 686 }
 687
 688 static int is_subdirectory(char *child, char *parent)
 689 {
 690         int l = strlen(parent);
 691
 692         return strcmp(child, parent) == 0
 693                 || (strncmp(child, parent, l) == 0 && child[l] == '/');
 694 }
 695
 696 static int path_matches(nfs_export *exp, char *path)
 697 {
 698         if (exp->m_export.e_flags & NFSEXP_CROSSMOUNT)
 699                 return is_subdirectory(path, exp->m_export.e_path);
 700         return strcmp(path, exp->m_export.e_path) == 0;
 701 }
 702
 703 static int
 704 client_matches(nfs_export *exp, char *dom, struct addrinfo *ai)
 705 {
 706         if (use_ipaddr)
 707                 return client_check(exp->m_client, ai);
 708         return client_member(dom, exp->m_client->m_hostname);
 709 }
 710
 711 static int
 712 export_matches(nfs_export *exp, char *dom, char *path, struct addrinfo *ai)
 713 {
 714         return path_matches(exp, path) && client_matches(exp, dom, ai);
 715 }
 716
 717 static nfs_export *
 718 lookup_export(char *dom, char *path, struct addrinfo *ai)
 719 {
 720         nfs_export *exp;
 721         nfs_export *found = NULL;
 722         int found_type = 0;
 723         int i;
 724
 725         for (i=0 ; i < MCL_MAXTYPES; i++) {
 726                 for (exp = exportlist[i].p_head; exp; exp = exp->m_next) {
 727                         if (!export_matches(exp, dom, path, ai))
 728                                 continue;
 729                         if (!found) {
 730                                 found = exp;
 731                                 found_type = i;
 732                                 continue;
 733                         }
 734
 735                         /* Always prefer non-V4ROOT mounts */
 736                         if (found->m_export.e_flags & NFSEXP_V4ROOT)
 737                                 continue;
 738
 739                         /* If one is a CROSSMOUNT, then prefer the longest path */
 740                         if (((found->m_export.e_flags & NFSEXP_CROSSMOUNT) ||
 741                              (exp->m_export.e_flags & NFSEXP_CROSSMOUNT)) &&
 742                             strlen(found->m_export.e_path) !=
 743                             strlen(exp->m_export.e_path)) {
 744
 745                                 if (strlen(exp->m_export.e_path) >
 746                                     strlen(found->m_export.e_path)) {
 747                                         found = exp;
 748                                         found_type = i;
 749                                 }
 750                                 continue;
 751
 752                         } else if (found_type == i && found->m_warned == 0) {
 753                                 xlog(L_WARNING, "%s exported to both %s and %s, "
 754                                      "arbitrarily choosing options from first",
 755                                      path, found->m_client->m_hostname, exp->m_client->m_hostname,
 756                                      dom);
 757                                 found->m_warned = 1;
 758                         }
 759                 }
 760         }
 761         return found;
 762 }
 763
 764 static void nfsd_export(FILE *f)
 765 {
 766         /* requests are:
 767          *  domain path
 768          * determine export options and return:
 769          *  domain path expiry flags anonuid anongid fsid
 770          */
 771
 772         char *cp;
 773         char *dom, *path;
 774         nfs_export *found = NULL;
 775         struct addrinfo *ai = NULL;
 776
 777         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
 778                 return;
 779
 780         xlog(D_CALL, "nfsd_export: inbuf '%s'", lbuf);
 781
 782         cp = lbuf;
 783         dom = malloc(strlen(cp));
 784         path = malloc(strlen(cp));
 785
 786         if (!dom || !path)
 787                 goto out;
 788
 789         if (qword_get(&cp, dom, strlen(lbuf)) <= 0)
 790                 goto out;
 791         if (qword_get(&cp, path, strlen(lbuf)) <= 0)
 792                 goto out;
 793
 794         auth_reload();
 795
 796         if (use_ipaddr) {
 797                 struct addrinfo *tmp;
 798                 tmp = host_pton(dom);
 799                 if (tmp == NULL)
 800                         goto out;
 801                 ai = client_resolve(tmp->ai_addr);
 802                 freeaddrinfo(tmp);
 803                         goto out;
 804         }
 805
 806         found = lookup_export(dom, path, ai);
 807
 808         if (found) {
 809                 if (dump_to_cache(f, dom, path, &found->m_export) < 0) {
 810                         xlog(L_WARNING,
 811                              "Cannot export %s, possibly unsupported filesystem"
 812                              " or fsid= required", path);
 813                         dump_to_cache(f, dom, path, NULL);
 814                 }
 815         } else {
 816                 dump_to_cache(f, dom, path, NULL);
 817         }
 818  out:
 819         xlog(D_CALL, "nfsd_export: found %p path %s", found, path ? path : NULL);
 820         if (dom) free(dom);
 821         if (path) free(path);
 822         freeaddrinfo(ai);
 823 }
 824
 825
 826 struct {
 827         char *cache_name;
 828         void (*cache_handle)(FILE *f);
 829         FILE *f;
 830         char vbuf[RPC_CHAN_BUF_SIZE];
 831 } cachelist[] = {
 832         { "auth.unix.ip", auth_unix_ip, NULL, ""},
 833         { "auth.unix.gid", auth_unix_gid, NULL, ""},
 834         { "nfsd.export", nfsd_export, NULL, ""},
 835         { "nfsd.fh", nfsd_fh, NULL, ""},
 836         { NULL, NULL, NULL, ""}
 837 };
 838
 839 extern int manage_gids;
 840
 841 /**
 842  * cache_open - prepare communications channels with kernel RPC caches
 843  *
 844  */
 845 void cache_open(void)
 846 {
 847         int i;
 848         for (i=0; cachelist[i].cache_name; i++ ) {
 849                 char path[100];
 850                 if (!manage_gids && cachelist[i].cache_handle == auth_unix_gid)
 851                         continue;
 852                 sprintf(path, "/proc/net/rpc/%s/channel", cachelist[i].cache_name);
 853                 cachelist[i].f = fopen(path, "r+");
 854                 if (cachelist[i].f != NULL) {
 855                         setvbuf(cachelist[i].f, cachelist[i].vbuf, _IOLBF,
 856                                 RPC_CHAN_BUF_SIZE);
 857                 }
 858         }
 859 }
 860
 861 /**
 862  * cache_set_fds - prepare cache file descriptors for one iteration of the service loop
 863  * @fdset: pointer to fd_set to prepare
 864  */
 865 void cache_set_fds(fd_set *fdset)
 866 {
 867         int i;
 868         for (i=0; cachelist[i].cache_name; i++) {
 869                 if (cachelist[i].f)
 870                         FD_SET(fileno(cachelist[i].f), fdset);
 871         }
 872 }
 873
 874 /**
 875  * cache_process_req - process any active cache file descriptors during service loop iteration
 876  * @fdset: pointer to fd_set to examine for activity
 877  */
 878 int cache_process_req(fd_set *readfds)
 879 {
 880         int i;
 881         int cnt = 0;
 882         for (i=0; cachelist[i].cache_name; i++) {
 883                 if (cachelist[i].f != NULL &&
 884                     FD_ISSET(fileno(cachelist[i].f), readfds)) {
 885                         cnt++;
 886                         cachelist[i].cache_handle(cachelist[i].f);
 887                         FD_CLR(fileno(cachelist[i].f), readfds);
 888                 }
 889         }
 890         return cnt;
 891 }
 892
 893
 894 /*
 895  * Give IP->domain and domain+path->options to kernel
 896  * % echo nfsd $IP  $[now+DEFAULT_TTL] $domain > /proc/net/rpc/auth.unix.ip/channel
 897  * % echo $domain $path $[now+DEFAULT_TTL] $options $anonuid $anongid $fsid > /proc/net/rpc/nfsd.export/channel
 898  */
 899
 900 static int cache_export_ent(char *domain, struct exportent *exp, char *path)
 901 {
 902         int err;
 903         FILE *f = fopen("/proc/net/rpc/nfsd.export/channel", "w");
 904         if (!f)
 905                 return -1;
 906
 907         err = dump_to_cache(f, domain, exp->e_path, exp);
 908         if (err) {
 909                 xlog(L_WARNING,
 910                      "Cannot export %s, possibly unsupported filesystem or"
 911                      " fsid= required", exp->e_path);
 912         }
 913
 914         while (err == 0 && (exp->e_flags & NFSEXP_CROSSMOUNT) && path) {
 915                 /* really an 'if', but we can break out of
 916                  * a 'while' more easily */
 917                 /* Look along 'path' for other filesystems
 918                  * and export them with the same options
 919                  */
 920                 struct stat stb;
 921                 size_t l = strlen(exp->e_path);
 922                 __dev_t dev;
 923
 924                 if (strlen(path) <= l || path[l] != '/' ||
 925                     strncmp(exp->e_path, path, l) != 0)
 926                         break;
 927                 if (stat(exp->e_path, &stb) != 0)
 928                         break;
 929                 dev = stb.st_dev;
 930                 while(path[l] == '/') {
 931                         char c;
 932                         /* errors for submount should fail whole filesystem */
 933                         int err2;
 934
 935                         l++;
 936                         while (path[l] != '/' && path[l])
 937                                 l++;
 938                         c = path[l];
 939                         path[l] = 0;
 940                         err2 = lstat(path, &stb);
 941                         path[l] = c;
 942                         if (err2 < 0)
 943                                 break;
 944                         if (stb.st_dev == dev)
 945                                 continue;
 946                         dev = stb.st_dev;
 947                         path[l] = 0;
 948                         dump_to_cache(f, domain, path, exp);
 949                         path[l] = c;
 950                 }
 951                 break;
 952         }
 953
 954         fclose(f);
 955         return err;
 956 }
 957
 958 /**
 959  * cache_export - Inform kernel of a new nfs_export
 960  * @exp: target nfs_export
 961  * @path: NUL-terminated C string containing export path
 962  */
 963 int cache_export(nfs_export *exp, char *path)
 964 {
 965         char buf[INET6_ADDRSTRLEN];
 966         int err;
 967         FILE *f;
 968
 969         f = fopen("/proc/net/rpc/auth.unix.ip/channel", "w");
 970         if (!f)
 971                 return -1;
 972
 973
 974         qword_print(f, "nfsd");
 975         qword_print(f,
 976                 host_ntop(get_addrlist(exp->m_client, 0), buf, sizeof(buf)));
 977         qword_printuint(f, time(0) + exp->m_export.e_ttl);
 978         qword_print(f, exp->m_client->m_hostname);
 979         err = qword_eol(f);
 980
 981         fclose(f);
 982
 983         err = cache_export_ent(exp->m_client->m_hostname, &exp->m_export, path)
 984                 || err;
 985         return err;
 986 }
 987
 988 /**
 989  * cache_get_filehandle - given an nfs_export, get its root filehandle
 990  * @exp: target nfs_export
 991  * @len: length of requested file handle
 992  * @p: NUL-terminated C string containing export path
 993  *
 994  * Returns pointer to NFS file handle of root directory of export
 995  *
 996  * {
 997  *   echo $domain $path $length
 998  *   read filehandle <&0
 999  * } <> /proc/fs/nfsd/filehandle
1000  */
1001 struct nfs_fh_len *
1002 cache_get_filehandle(nfs_export *exp, int len, char *p)
1003 {
1004         FILE *f = fopen("/proc/fs/nfsd/filehandle", "r+");
1005         char buf[200];
1006         char *bp = buf;
1007         int failed;
1008         static struct nfs_fh_len fh;
1009
1010         if (!f)
1011                 f = fopen("/proc/fs/nfs/filehandle", "r+");
1012         if (!f)
1013                 return NULL;
1014
1015         qword_print(f, exp->m_client->m_hostname);
1016         qword_print(f, p);
1017         qword_printint(f, len);
1018         failed = qword_eol(f);
1019
1020         if (!failed)
1021                 failed = (fgets(buf, sizeof(buf), f) == NULL);
1022         fclose(f);
1023         if (failed)
1024                 return NULL;
1025         memset(fh.fh_handle, 0, sizeof(fh.fh_handle));
1026         fh.fh_size = qword_get(&bp, (char *)fh.fh_handle, NFS3_FHSIZE);
1027         return &fh;
1028 }