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 addrinfo *tmp = NULL;
  81         struct addrinfo *ai = 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         tmp = host_pton(ipaddr);
  97         if (tmp == NULL)
  98                 return;
  99
 100         auth_reload();
 101
 102         /* addr is a valid, interesting address, find the domain name... */
 103         if (!use_ipaddr) {
 104                 ai = client_resolve(tmp->ai_addr);
 105                 client = client_compose(ai);
 106                 freeaddrinfo(ai);
 107         }
 108         freeaddrinfo(tmp);
 109
 110         qword_print(f, "nfsd");
 111         qword_print(f, ipaddr);
 112         qword_printint(f, time(0)+30*60);
 113         if (use_ipaddr)
 114                 qword_print(f, ipaddr);
 115         else if (client)
 116                 qword_print(f, *client?client:"DEFAULT");
 117         qword_eol(f);
 118         xlog(D_CALL, "auth_unix_ip: client %p '%s'", client, client?client: "DEFAULT");
 119
 120         free(client);
 121 }
 122
 123 void auth_unix_gid(FILE *f)
 124 {
 125         /* Request are
 126          *  uid
 127          * reply is
 128          *  uid expiry count list of group ids
 129          */
 130         uid_t uid;
 131         struct passwd *pw;
 132         gid_t glist[100], *groups = glist;
 133         int ngroups = 100;
 134         int rv, i;
 135         char *cp;
 136
 137         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
 138                 return;
 139
 140         cp = lbuf;
 141         if (qword_get_uint(&cp, &uid) != 0)
 142                 return;
 143
 144         pw = getpwuid(uid);
 145         if (!pw)
 146                 rv = -1;
 147         else {
 148                 rv = getgrouplist(pw->pw_name, pw->pw_gid, groups, &ngroups);
 149                 if (rv == -1 && ngroups >= 100) {
 150                         groups = malloc(sizeof(gid_t)*ngroups);
 151                         if (!groups)
 152                                 rv = -1;
 153                         else
 154                                 rv = getgrouplist(pw->pw_name, pw->pw_gid,
 155                                                   groups, &ngroups);
 156                 }
 157         }
 158         qword_printuint(f, uid);
 159         qword_printuint(f, time(0)+30*60);
 160         if (rv >= 0) {
 161                 qword_printuint(f, ngroups);
 162                 for (i=0; i<ngroups; i++)
 163                         qword_printuint(f, groups[i]);
 164         } else
 165                 qword_printuint(f, 0);
 166         qword_eol(f);
 167
 168         if (groups != glist)
 169                 free(groups);
 170 }
 171
 172 #if USE_BLKID
 173 static const char *get_uuid_blkdev(char *path)
 174 {
 175         /* We set *safe if we know that we need the
 176          * fsid from statfs too.
 177          */
 178         static blkid_cache cache = NULL;
 179         struct stat stb;
 180         char *devname;
 181         blkid_tag_iterate iter;
 182         blkid_dev dev;
 183         const char *type;
 184         const char *val, *uuid = NULL;
 185
 186         if (cache == NULL)
 187                 blkid_get_cache(&cache, NULL);
 188
 189         if (stat(path, &stb) != 0)
 190                 return NULL;
 191         devname = blkid_devno_to_devname(stb.st_dev);
 192         if (!devname)
 193                 return NULL;
 194         dev = blkid_get_dev(cache, devname, BLKID_DEV_NORMAL);
 195         free(devname);
 196         if (!dev)
 197                 return NULL;
 198         iter = blkid_tag_iterate_begin(dev);
 199         if (!iter)
 200                 return NULL;
 201         while (blkid_tag_next(iter, &type, &val) == 0) {
 202                 if (strcmp(type, "UUID") == 0)
 203                         uuid = val;
 204                 if (strcmp(type, "TYPE") == 0 &&
 205                     strcmp(val, "btrfs") == 0) {
 206                         uuid = NULL;
 207                         break;
 208                 }
 209         }
 210         blkid_tag_iterate_end(iter);
 211         return uuid;
 212 }
 213 #else
 214 #define get_uuid_blkdev(path) (NULL)
 215 #endif
 216
 217 int get_uuid(const char *val, int uuidlen, char *u)
 218 {
 219         /* extract hex digits from uuidstr and compose a uuid
 220          * of the given length (max 16), xoring bytes to make
 221          * a smaller uuid.
 222          */
 223         int i = 0;
 224
 225         memset(u, 0, uuidlen);
 226         for ( ; *val ; val++) {
 227                 char c = *val;
 228                 if (!isxdigit(c))
 229                         continue;
 230                 if (isalpha(c)) {
 231                         if (isupper(c))
 232                                 c = c - 'A' + 10;
 233                         else
 234                                 c = c - 'a' + 10;
 235                 } else
 236                         c = c - '0' + 0;
 237                 if ((i&1) == 0)
 238                         c <<= 4;
 239                 u[i/2] ^= c;
 240                 i++;
 241                 if (i == uuidlen*2)
 242                         i = 0;
 243         }
 244         return 1;
 245 }
 246
 247 int uuid_by_path(char *path, int type, int uuidlen, char *uuid)
 248 {
 249         /* get a uuid for the filesystem found at 'path'.
 250          * There are several possible ways of generating the
 251          * uuids (types).
 252          * Type 0 is used for new filehandles, while other types
 253          * may be used to interpret old filehandle - to ensure smooth
 254          * forward migration.
 255          * We return 1 if a uuid was found (and it might be worth
 256          * trying the next type) or 0 if no more uuid types can be
 257          * extracted.
 258          */
 259
 260         /* Possible sources of uuid are
 261          * - blkid uuid
 262          * - statfs64 uuid
 263          *
 264          * On some filesystems (e.g. vfat) the statfs64 uuid is simply an
 265          * encoding of the device that the filesystem is mounted from, so
 266          * it we be very bad to use that (as device numbers change).  blkid
 267          * must be preferred.
 268          * On other filesystems (e.g. btrfs) the statfs64 uuid contains
 269          * important info that the blkid uuid cannot contain:  This happens
 270          * when multiple subvolumes are exported (they have the same
 271          * blkid uuid but different statfs64 uuids).
 272          * We rely on get_uuid_blkdev *knowing* which is which and not returning
 273          * a uuid for filesystems where the statfs64 uuid is better.
 274          *
 275          */
 276         struct statfs64 st;
 277         char fsid_val[17];
 278         const char *blkid_val;
 279         const char *val;
 280
 281         blkid_val = get_uuid_blkdev(path);
 282
 283         if (statfs64(path, &st) == 0 &&
 284             (st.f_fsid.__val[0] || st.f_fsid.__val[1]))
 285                 snprintf(fsid_val, 17, "%08x%08x",
 286                          st.f_fsid.__val[0], st.f_fsid.__val[1]);
 287         else
 288                 fsid_val[0] = 0;
 289
 290         if (blkid_val && (type--) == 0)
 291                 val = blkid_val;
 292         else if (fsid_val[0] && (type--) == 0)
 293                 val = fsid_val;
 294         else
 295                 return 0;
 296
 297         get_uuid(val, uuidlen, uuid);
 298         return 1;
 299 }
 300
 301 /* Iterate through /etc/mtab, finding mountpoints
 302  * at or below a given path
 303  */
 304 static char *next_mnt(void **v, char *p)
 305 {
 306         FILE *f;
 307         struct mntent *me;
 308         int l = strlen(p);
 309         if (*v == NULL) {
 310                 f = setmntent("/etc/mtab", "r");
 311                 *v = f;
 312         } else
 313                 f = *v;
 314         while ((me = getmntent(f)) != NULL &&
 315                (strncmp(me->mnt_dir, p, l) != 0 ||
 316                 me->mnt_dir[l] != '/'))
 317                 ;
 318         if (me == NULL) {
 319                 endmntent(f);
 320                 *v = NULL;
 321                 return NULL;
 322         }
 323         return me->mnt_dir;
 324 }
 325
 326 void nfsd_fh(FILE *f)
 327 {
 328         /* request are:
 329          *  domain fsidtype fsid
 330          * interpret fsid, find export point and options, and write:
 331          *  domain fsidtype fsid expiry path
 332          */
 333         char *cp;
 334         char *dom;
 335         int fsidtype;
 336         int fsidlen;
 337         unsigned int dev, major=0, minor=0;
 338         unsigned int inode=0;
 339         unsigned long long inode64;
 340         unsigned int fsidnum=0;
 341         char fsid[32];
 342         struct exportent *found = NULL;
 343         struct addrinfo *ai = NULL;
 344         char *found_path = NULL;
 345         nfs_export *exp;
 346         int i;
 347         int dev_missing = 0;
 348         int uuidlen = 0;
 349         char *fhuuid = NULL;
 350
 351         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
 352                 return;
 353
 354         xlog(D_CALL, "nfsd_fh: inbuf '%s'", lbuf);
 355
 356         cp = lbuf;
 357
 358         dom = malloc(strlen(cp));
 359         if (dom == NULL)
 360                 return;
 361         if (qword_get(&cp, dom, strlen(cp)) <= 0)
 362                 goto out;
 363         if (qword_get_int(&cp, &fsidtype) != 0)
 364                 goto out;
 365         if (fsidtype < 0 || fsidtype > 7)
 366                 goto out; /* unknown type */
 367         if ((fsidlen = qword_get(&cp, fsid, 32)) <= 0)
 368                 goto out;
 369         switch(fsidtype) {
 370         case FSID_DEV: /* 4 bytes: 2 major, 2 minor, 4 inode */
 371                 if (fsidlen != 8)
 372                         goto out;
 373                 memcpy(&dev, fsid, 4);
 374                 memcpy(&inode, fsid+4, 4);
 375                 major = ntohl(dev)>>16;
 376                 minor = ntohl(dev) & 0xFFFF;
 377                 break;
 378
 379         case FSID_NUM: /* 4 bytes - fsid */
 380                 if (fsidlen != 4)
 381                         goto out;
 382                 memcpy(&fsidnum, fsid, 4);
 383                 break;
 384
 385         case FSID_MAJOR_MINOR: /* 12 bytes: 4 major, 4 minor, 4 inode
 386                  * This format is never actually used but was
 387                  * an historical accident
 388                  */
 389                 if (fsidlen != 12)
 390                         goto out;
 391                 memcpy(&dev, fsid, 4); major = ntohl(dev);
 392                 memcpy(&dev, fsid+4, 4); minor = ntohl(dev);
 393                 memcpy(&inode, fsid+8, 4);
 394                 break;
 395
 396         case FSID_ENCODE_DEV: /* 8 bytes: 4 byte packed device number, 4 inode */
 397                 /* This is *host* endian, not net-byte-order, because
 398                  * no-one outside this host has any business interpreting it
 399                  */
 400                 if (fsidlen != 8)
 401                         goto out;
 402                 memcpy(&dev, fsid, 4);
 403                 memcpy(&inode, fsid+4, 4);
 404                 major = (dev & 0xfff00) >> 8;
 405                 minor = (dev & 0xff) | ((dev >> 12) & 0xfff00);
 406                 break;
 407
 408         case FSID_UUID4_INUM: /* 4 byte inode number and 4 byte uuid */
 409                 if (fsidlen != 8)
 410                         goto out;
 411                 memcpy(&inode, fsid, 4);
 412                 uuidlen = 4;
 413                 fhuuid = fsid+4;
 414                 break;
 415         case FSID_UUID8: /* 8 byte uuid */
 416                 if (fsidlen != 8)
 417                         goto out;
 418                 uuidlen = 8;
 419                 fhuuid = fsid;
 420                 break;
 421         case FSID_UUID16: /* 16 byte uuid */
 422                 if (fsidlen != 16)
 423                         goto out;
 424                 uuidlen = 16;
 425                 fhuuid = fsid;
 426                 break;
 427         case FSID_UUID16_INUM: /* 8 byte inode number and 16 byte uuid */
 428                 if (fsidlen != 24)
 429                         goto out;
 430                 memcpy(&inode64, fsid, 8);
 431                 inode = inode64;
 432                 uuidlen = 16;
 433                 fhuuid = fsid+8;
 434                 break;
 435         }
 436
 437         auth_reload();
 438
 439         /* Now determine export point for this fsid/domain */
 440         for (i=0 ; i < MCL_MAXTYPES; i++) {
 441                 nfs_export *next_exp;
 442                 for (exp = exportlist[i].p_head; exp; exp = next_exp) {
 443                         struct stat stb;
 444                         char u[16];
 445                         char *path;
 446                         int type;
 447
 448                         if (exp->m_export.e_flags & NFSEXP_CROSSMOUNT) {
 449                                 static nfs_export *prev = NULL;
 450                                 static void *mnt = NULL;
 451
 452                                 if (prev == exp) {
 453                                         /* try a submount */
 454                                         path = next_mnt(&mnt, exp->m_export.e_path);
 455                                         if (!path) {
 456                                                 next_exp = exp->m_next;
 457                                                 prev = NULL;
 458                                                 continue;
 459                                         }
 460                                         next_exp = exp;
 461                                 } else {
 462                                         prev = exp;
 463                                         mnt = NULL;
 464                                         path = exp->m_export.e_path;
 465                                         next_exp = exp;
 466                                 }
 467                         } else {
 468                                 path = exp->m_export.e_path;
 469                                 next_exp = exp->m_next;
 470                         }
 471
 472                         if (!use_ipaddr && !client_member(dom, exp->m_client->m_hostname))
 473                                 continue;
 474                         if (exp->m_export.e_mountpoint &&
 475                             !is_mountpoint(exp->m_export.e_mountpoint[0]?
 476                                            exp->m_export.e_mountpoint:
 477                                            exp->m_export.e_path))
 478                                 dev_missing ++;
 479                         if (stat(path, &stb) != 0)
 480                                 continue;
 481                         if (!S_ISDIR(stb.st_mode) && !S_ISREG(stb.st_mode)) {
 482                                 continue;
 483                         }
 484                         switch(fsidtype){
 485                         case FSID_DEV:
 486                         case FSID_MAJOR_MINOR:
 487                         case FSID_ENCODE_DEV:
 488                                 if (stb.st_ino != inode)
 489                                         continue;
 490                                 if (major != major(stb.st_dev) ||
 491                                     minor != minor(stb.st_dev))
 492                                         continue;
 493                                 break;
 494                         case FSID_NUM:
 495                                 if (((exp->m_export.e_flags & NFSEXP_FSID) == 0 ||
 496                                      exp->m_export.e_fsid != fsidnum))
 497                                         continue;
 498                                 break;
 499                         case FSID_UUID4_INUM:
 500                         case FSID_UUID16_INUM:
 501                                 if (stb.st_ino != inode)
 502                                         continue;
 503                                 goto check_uuid;
 504                         case FSID_UUID8:
 505                         case FSID_UUID16:
 506                                 if (!is_mountpoint(path))
 507                                         continue;
 508                         check_uuid:
 509                                 if (exp->m_export.e_uuid)
 510                                         get_uuid(exp->m_export.e_uuid,
 511                                                  uuidlen, u);
 512                                 else
 513                                         for (type = 0;
 514                                              uuid_by_path(path, type, uuidlen, u);
 515                                              type++)
 516                                                 if (memcmp(u, fhuuid, uuidlen) == 0)
 517                                                         break;
 518
 519                                 if (memcmp(u, fhuuid, uuidlen) != 0)
 520                                         continue;
 521                                 break;
 522                         }
 523                         if (use_ipaddr) {
 524                                 if (ai == NULL) {
 525                                         struct addrinfo *tmp;
 526                                         tmp = host_pton(dom);
 527                                         if (tmp == NULL)
 528                                                 goto out;
 529                                         ai = client_resolve(tmp->ai_addr);
 530                                         freeaddrinfo(tmp);
 531                                 }
 532                                 if (!client_check(exp->m_client, ai))
 533                                         continue;
 534                         }
 535                         /* It's a match !! */
 536                         if (!found) {
 537                                 found = &exp->m_export;
 538                                 found_path = strdup(path);
 539                                 if (found_path == NULL)
 540                                         goto out;
 541                         } else if (strcmp(found->e_path, exp->m_export.e_path)!= 0)
 542                         {
 543                                 xlog(L_WARNING, "%s and %s have same filehandle for %s, using first",
 544                                      found_path, path, dom);
 545                         }
 546                 }
 547         }
 548         if (found &&
 549             found->e_mountpoint &&
 550             !is_mountpoint(found->e_mountpoint[0]?
 551                            found->e_mountpoint:
 552                            found->e_path)) {
 553                 /* Cannot export this yet
 554                  * should log a warning, but need to rate limit
 555                    xlog(L_WARNING, "%s not exported as %d not a mountpoint",
 556                    found->e_path, found->e_mountpoint);
 557                  */
 558                 /* FIXME we need to make sure we re-visit this later */
 559                 goto out;
 560         }
 561         if (!found && dev_missing) {
 562                 /* The missing dev could be what we want, so just be
 563                  * quite rather than returning stale yet
 564                  */
 565                 goto out;
 566         }
 567
 568         if (found)
 569                 if (cache_export_ent(dom, found, found_path) < 0)
 570                         found = 0;
 571
 572         qword_print(f, dom);
 573         qword_printint(f, fsidtype);
 574         qword_printhex(f, fsid, fsidlen);
 575         /* The fsid -> path lookup can be quite expensive as it
 576          * potentially stats and reads lots of devices, and some of those
 577          * might have spun-down.  The Answer is not likely to
 578          * change underneath us, and an 'exportfs -f' can always
 579          * remove this from the kernel, so use a really log
 580          * timeout.  Maybe this should be configurable on the command
 581          * line.
 582          */
 583         qword_printint(f, 0x7fffffff);
 584         if (found)
 585                 qword_print(f, found_path);
 586         qword_eol(f);
 587  out:
 588         if (found_path)
 589                 free(found_path);
 590         freeaddrinfo(ai);
 591         free(dom);
 592         xlog(D_CALL, "nfsd_fh: found %p path %s", found, found ? found->e_path : NULL);
 593         return;
 594 }
 595
 596 static void write_fsloc(FILE *f, struct exportent *ep, char *path)
 597 {
 598         struct servers *servers;
 599
 600         if (ep->e_fslocmethod == FSLOC_NONE)
 601                 return;
 602
 603         servers = replicas_lookup(ep->e_fslocmethod, ep->e_fslocdata);
 604         if (!servers)
 605                 return;
 606         qword_print(f, "fsloc");
 607         qword_printint(f, servers->h_num);
 608         if (servers->h_num >= 0) {
 609                 int i;
 610                 for (i=0; i<servers->h_num; i++) {
 611                         qword_print(f, servers->h_mp[i]->h_host);
 612                         qword_print(f, servers->h_mp[i]->h_path);
 613                 }
 614         }
 615         qword_printint(f, servers->h_referral);
 616         release_replicas(servers);
 617 }
 618
 619 static void write_secinfo(FILE *f, struct exportent *ep, int flag_mask)
 620 {
 621         struct sec_entry *p;
 622
 623         for (p = ep->e_secinfo; p->flav; p++)
 624                 ; /* Do nothing */
 625         if (p == ep->e_secinfo) {
 626                 /* There was no sec= option */
 627                 return;
 628         }
 629         qword_print(f, "secinfo");
 630         qword_printint(f, p - ep->e_secinfo);
 631         for (p = ep->e_secinfo; p->flav; p++) {
 632                 qword_printint(f, p->flav->fnum);
 633                 qword_printint(f, p->flags & flag_mask);
 634         }
 635
 636 }
 637
 638 static int dump_to_cache(FILE *f, char *domain, char *path, struct exportent *exp)
 639 {
 640         qword_print(f, domain);
 641         qword_print(f, path);
 642         qword_printint(f, time(0)+30*60);
 643         if (exp) {
 644                 int different_fs = strcmp(path, exp->e_path) != 0;
 645                 int flag_mask = different_fs ? ~NFSEXP_FSID : ~0;
 646
 647                 qword_printint(f, exp->e_flags & flag_mask);
 648                 qword_printint(f, exp->e_anonuid);
 649                 qword_printint(f, exp->e_anongid);
 650                 qword_printint(f, exp->e_fsid);
 651                 write_fsloc(f, exp, path);
 652                 write_secinfo(f, exp, flag_mask);
 653                 if (exp->e_uuid == NULL || different_fs) {
 654                         char u[16];
 655                         if (uuid_by_path(path, 0, 16, u)) {
 656                                 qword_print(f, "uuid");
 657                                 qword_printhex(f, u, 16);
 658                         }
 659                 } else {
 660                         char u[16];
 661                         get_uuid(exp->e_uuid, 16, u);
 662                         qword_print(f, "uuid");
 663                         qword_printhex(f, u, 16);
 664                 }
 665         }
 666         return qword_eol(f);
 667 }
 668
 669 static int is_subdirectory(char *child, char *parent)
 670 {
 671         int l = strlen(parent);
 672
 673         return strcmp(child, parent) == 0
 674                 || (strncmp(child, parent, l) == 0 && child[l] == '/');
 675 }
 676
 677 static int path_matches(nfs_export *exp, char *path)
 678 {
 679         if (exp->m_export.e_flags & NFSEXP_CROSSMOUNT)
 680                 return is_subdirectory(path, exp->m_export.e_path);
 681         return strcmp(path, exp->m_export.e_path) == 0;
 682 }
 683
 684 static int
 685 client_matches(nfs_export *exp, char *dom, struct addrinfo *ai)
 686 {
 687         if (use_ipaddr)
 688                 return client_check(exp->m_client, ai);
 689         return client_member(dom, exp->m_client->m_hostname);
 690 }
 691
 692 static int
 693 export_matches(nfs_export *exp, char *dom, char *path, struct addrinfo *ai)
 694 {
 695         return path_matches(exp, path) && client_matches(exp, dom, ai);
 696 }
 697
 698 static nfs_export *
 699 lookup_export(char *dom, char *path, struct addrinfo *ai)
 700 {
 701         nfs_export *exp;
 702         nfs_export *found = NULL;
 703         int found_type = 0;
 704         int i;
 705
 706         for (i=0 ; i < MCL_MAXTYPES; i++) {
 707                 for (exp = exportlist[i].p_head; exp; exp = exp->m_next) {
 708                         if (!export_matches(exp, dom, path, ai))
 709                                 continue;
 710                         if (!found) {
 711                                 found = exp;
 712                                 found_type = i;
 713                                 continue;
 714                         }
 715
 716                         /* Always prefer non-V4ROOT mounts */
 717                         if (found->m_export.e_flags & NFSEXP_V4ROOT)
 718                                 continue;
 719
 720                         /* If one is a CROSSMOUNT, then prefer the longest path */
 721                         if (((found->m_export.e_flags & NFSEXP_CROSSMOUNT) ||
 722                              (exp->m_export.e_flags & NFSEXP_CROSSMOUNT)) &&
 723                             strlen(found->m_export.e_path) !=
 724                             strlen(exp->m_export.e_path)) {
 725
 726                                 if (strlen(exp->m_export.e_path) >
 727                                     strlen(found->m_export.e_path)) {
 728                                         found = exp;
 729                                         found_type = i;
 730                                 }
 731                                 continue;
 732
 733                         } else if (found_type == i && found->m_warned == 0) {
 734                                 xlog(L_WARNING, "%s exported to both %s and %s, "
 735                                      "arbitrarily choosing options from first",
 736                                      path, found->m_client->m_hostname, exp->m_client->m_hostname,
 737                                      dom);
 738                                 found->m_warned = 1;
 739                         }
 740                 }
 741         }
 742         return found;
 743 }
 744
 745 void nfsd_export(FILE *f)
 746 {
 747         /* requests are:
 748          *  domain path
 749          * determine export options and return:
 750          *  domain path expiry flags anonuid anongid fsid
 751          */
 752
 753         char *cp;
 754         char *dom, *path;
 755         nfs_export *found = NULL;
 756         struct addrinfo *ai = NULL;
 757
 758         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
 759                 return;
 760
 761         xlog(D_CALL, "nfsd_export: inbuf '%s'", lbuf);
 762
 763         cp = lbuf;
 764         dom = malloc(strlen(cp));
 765         path = malloc(strlen(cp));
 766
 767         if (!dom || !path)
 768                 goto out;
 769
 770         if (qword_get(&cp, dom, strlen(lbuf)) <= 0)
 771                 goto out;
 772         if (qword_get(&cp, path, strlen(lbuf)) <= 0)
 773                 goto out;
 774
 775         auth_reload();
 776
 777         if (use_ipaddr) {
 778                 struct addrinfo *tmp;
 779                 tmp = host_pton(dom);
 780                 if (tmp == NULL)
 781                         goto out;
 782                 ai = client_resolve(tmp->ai_addr);
 783                 freeaddrinfo(tmp);
 784                         goto out;
 785         }
 786
 787         found = lookup_export(dom, path, ai);
 788
 789         if (found) {
 790                 if (dump_to_cache(f, dom, path, &found->m_export) < 0) {
 791                         xlog(L_WARNING,
 792                              "Cannot export %s, possibly unsupported filesystem"
 793                              " or fsid= required", path);
 794                         dump_to_cache(f, dom, path, NULL);
 795                 }
 796         } else {
 797                 dump_to_cache(f, dom, path, NULL);
 798         }
 799  out:
 800         xlog(D_CALL, "nfsd_export: found %p path %s", found, path ? path : NULL);
 801         if (dom) free(dom);
 802         if (path) free(path);
 803         freeaddrinfo(ai);
 804 }
 805
 806
 807 struct {
 808         char *cache_name;
 809         void (*cache_handle)(FILE *f);
 810         FILE *f;
 811 } cachelist[] = {
 812         { "auth.unix.ip", auth_unix_ip},
 813         { "auth.unix.gid", auth_unix_gid},
 814         { "nfsd.export", nfsd_export},
 815         { "nfsd.fh", nfsd_fh},
 816         { NULL, NULL }
 817 };
 818
 819 extern int manage_gids;
 820 void cache_open(void)
 821 {
 822         int i;
 823         for (i=0; cachelist[i].cache_name; i++ ) {
 824                 char path[100];
 825                 if (!manage_gids && cachelist[i].cache_handle == auth_unix_gid)
 826                         continue;
 827                 sprintf(path, "/proc/net/rpc/%s/channel", cachelist[i].cache_name);
 828                 cachelist[i].f = fopen(path, "r+");
 829         }
 830 }
 831
 832 void cache_set_fds(fd_set *fdset)
 833 {
 834         int i;
 835         for (i=0; cachelist[i].cache_name; i++) {
 836                 if (cachelist[i].f)
 837                         FD_SET(fileno(cachelist[i].f), fdset);
 838         }
 839 }
 840
 841 int cache_process_req(fd_set *readfds)
 842 {
 843         int i;
 844         int cnt = 0;
 845         for (i=0; cachelist[i].cache_name; i++) {
 846                 if (cachelist[i].f != NULL &&
 847                     FD_ISSET(fileno(cachelist[i].f), readfds)) {
 848                         cnt++;
 849                         cachelist[i].cache_handle(cachelist[i].f);
 850                         FD_CLR(fileno(cachelist[i].f), readfds);
 851                 }
 852         }
 853         return cnt;
 854 }
 855
 856
 857 /*
 858  * Give IP->domain and domain+path->options to kernel
 859  * % echo nfsd $IP  $[now+30*60] $domain > /proc/net/rpc/auth.unix.ip/channel
 860  * % echo $domain $path $[now+30*60] $options $anonuid $anongid $fsid > /proc/net/rpc/nfsd.export/channel
 861  */
 862
 863 int cache_export_ent(char *domain, struct exportent *exp, char *path)
 864 {
 865         int err;
 866         FILE *f = fopen("/proc/net/rpc/nfsd.export/channel", "w");
 867         if (!f)
 868                 return -1;
 869
 870         err = dump_to_cache(f, domain, exp->e_path, exp);
 871         if (err) {
 872                 xlog(L_WARNING,
 873                      "Cannot export %s, possibly unsupported filesystem or"
 874                      " fsid= required", exp->e_path);
 875         }
 876
 877         while (err == 0 && (exp->e_flags & NFSEXP_CROSSMOUNT) && path) {
 878                 /* really an 'if', but we can break out of
 879                  * a 'while' more easily */
 880                 /* Look along 'path' for other filesystems
 881                  * and export them with the same options
 882                  */
 883                 struct stat stb;
 884                 int l = strlen(exp->e_path);
 885                 int dev;
 886
 887                 if (strlen(path) <= l || path[l] != '/' ||
 888                     strncmp(exp->e_path, path, l) != 0)
 889                         break;
 890                 if (stat(exp->e_path, &stb) != 0)
 891                         break;
 892                 dev = stb.st_dev;
 893                 while(path[l] == '/') {
 894                         char c;
 895                         /* errors for submount should fail whole filesystem */
 896                         int err2;
 897
 898                         l++;
 899                         while (path[l] != '/' && path[l])
 900                                 l++;
 901                         c = path[l];
 902                         path[l] = 0;
 903                         err2 = lstat(path, &stb);
 904                         path[l] = c;
 905                         if (err2 < 0)
 906                                 break;
 907                         if (stb.st_dev == dev)
 908                                 continue;
 909                         dev = stb.st_dev;
 910                         path[l] = 0;
 911                         dump_to_cache(f, domain, path, exp);
 912                         path[l] = c;
 913                 }
 914                 break;
 915         }
 916
 917         fclose(f);
 918         return err;
 919 }
 920
 921 int cache_export(nfs_export *exp, char *path)
 922 {
 923         char buf[INET_ADDRSTRLEN];
 924         int err;
 925         FILE *f;
 926
 927         f = fopen("/proc/net/rpc/auth.unix.ip/channel", "w");
 928         if (!f)
 929                 return -1;
 930
 931
 932         qword_print(f, "nfsd");
 933         qword_print(f,
 934                 host_ntop(get_addrlist(exp->m_client, 0), buf, sizeof(buf)));
 935         qword_printint(f, time(0)+30*60);
 936         qword_print(f, exp->m_client->m_hostname);
 937         err = qword_eol(f);
 938
 939         fclose(f);
 940
 941         err = cache_export_ent(exp->m_client->m_hostname, &exp->m_export, path)
 942                 || err;
 943         return err;
 944 }
 945
 946 /* Get a filehandle.
 947  * {
 948  *   echo $domain $path $length
 949  *   read filehandle <&0
 950  * } <> /proc/fs/nfsd/filehandle
 951  */
 952 struct nfs_fh_len *
 953 cache_get_filehandle(nfs_export *exp, int len, char *p)
 954 {
 955         FILE *f = fopen("/proc/fs/nfsd/filehandle", "r+");
 956         char buf[200];
 957         char *bp = buf;
 958         int failed;
 959         static struct nfs_fh_len fh;
 960
 961         if (!f)
 962                 f = fopen("/proc/fs/nfs/filehandle", "r+");
 963         if (!f)
 964                 return NULL;
 965
 966         qword_print(f, exp->m_client->m_hostname);
 967         qword_print(f, p);
 968         qword_printint(f, len);
 969         failed = qword_eol(f);
 970
 971         if (!failed)
 972                 failed = (fgets(buf, sizeof(buf), f) == NULL);
 973         fclose(f);
 974         if (failed)
 975                 return NULL;
 976         memset(fh.fh_handle, 0, sizeof(fh.fh_handle));
 977         fh.fh_size = qword_get(&bp, (char *)fh.fh_handle, NFS3_FHSIZE);
 978         return &fh;
 979 }
 980