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 /* True iff e1 is a child of e2 and e2 has crossmnt set: */
 345 static bool subexport(struct exportent *e1, struct exportent *e2)
 346 {
 347         char *p1 = e1->e_path, *p2 = e2->e_path;
 348         int l2 = strlen(p2);
 349
 350         return e2->e_flags & NFSEXP_CROSSMOUNT
 351                && strncmp(p1, p2, l2) == 0
 352                && p1[l2] == '/';
 353 }
 354
 355 struct parsed_fsid {
 356         int fsidtype;
 357         /* We could use a union for this, but it would be more
 358          * complicated; why bother? */
 359         unsigned int inode;
 360         unsigned int minor;
 361         unsigned int major;
 362         unsigned int fsidnum;
 363         int uuidlen;
 364         char *fhuuid;
 365 };
 366
 367 int parse_fsid(int fsidtype, int fsidlen, char *fsid, struct parsed_fsid *parsed)
 368 {
 369         unsigned int dev;
 370         unsigned long long inode64;
 371
 372         parsed->fsidtype = fsidtype;
 373         switch(fsidtype) {
 374         case FSID_DEV: /* 4 bytes: 2 major, 2 minor, 4 inode */
 375                 if (fsidlen != 8)
 376                         return -1;
 377                 memcpy(&dev, fsid, 4);
 378                 memcpy(&parsed->inode, fsid+4, 4);
 379                 parsed->major = ntohl(dev)>>16;
 380                 parsed->minor = ntohl(dev) & 0xFFFF;
 381                 break;
 382
 383         case FSID_NUM: /* 4 bytes - fsid */
 384                 if (fsidlen != 4)
 385                         return -1;
 386                 memcpy(&parsed->fsidnum, fsid, 4);
 387                 break;
 388
 389         case FSID_MAJOR_MINOR: /* 12 bytes: 4 major, 4 minor, 4 inode
 390                  * This format is never actually used but was
 391                  * an historical accident
 392                  */
 393                 if (fsidlen != 12)
 394                         return -1;
 395                 memcpy(&dev, fsid, 4);
 396                 parsed->major = ntohl(dev);
 397                 memcpy(&dev, fsid+4, 4);
 398                 parsed->minor = ntohl(dev);
 399                 memcpy(&parsed->inode, fsid+8, 4);
 400                 break;
 401
 402         case FSID_ENCODE_DEV: /* 8 bytes: 4 byte packed device number, 4 inode */
 403                 /* This is *host* endian, not net-byte-order, because
 404                  * no-one outside this host has any business interpreting it
 405                  */
 406                 if (fsidlen != 8)
 407                         return -1;
 408                 memcpy(&dev, fsid, 4);
 409                 memcpy(&parsed->inode, fsid+4, 4);
 410                 parsed->major = (dev & 0xfff00) >> 8;
 411                 parsed->minor = (dev & 0xff) | ((dev >> 12) & 0xfff00);
 412                 break;
 413
 414         case FSID_UUID4_INUM: /* 4 byte inode number and 4 byte uuid */
 415                 if (fsidlen != 8)
 416                         return -1;
 417                 memcpy(&parsed->inode, fsid, 4);
 418                 parsed->uuidlen = 4;
 419                 parsed->fhuuid = fsid+4;
 420                 break;
 421         case FSID_UUID8: /* 8 byte uuid */
 422                 if (fsidlen != 8)
 423                         return -1;
 424                 parsed->uuidlen = 8;
 425                 parsed->fhuuid = fsid;
 426                 break;
 427         case FSID_UUID16: /* 16 byte uuid */
 428                 if (fsidlen != 16)
 429                         return -1;
 430                 parsed->uuidlen = 16;
 431                 parsed->fhuuid = fsid;
 432                 break;
 433         case FSID_UUID16_INUM: /* 8 byte inode number and 16 byte uuid */
 434                 if (fsidlen != 24)
 435                         return -1;
 436                 memcpy(&inode64, fsid, 8);
 437                 parsed->inode = inode64;
 438                 parsed->uuidlen = 16;
 439                 parsed->fhuuid = fsid+8;
 440                 break;
 441         }
 442         return 0;
 443 }
 444
 445 static bool match_fsid(struct parsed_fsid *parsed, nfs_export *exp, char *path)
 446 {
 447         struct stat stb;
 448         int type;
 449         char u[16];
 450
 451         if (stat(path, &stb) != 0)
 452                 return false;
 453         if (!S_ISDIR(stb.st_mode) && !S_ISREG(stb.st_mode))
 454                 return false;
 455
 456         switch (parsed->fsidtype) {
 457         case FSID_DEV:
 458         case FSID_MAJOR_MINOR:
 459         case FSID_ENCODE_DEV:
 460                 if (stb.st_ino != parsed->inode)
 461                         return false;
 462                 if (parsed->major != major(stb.st_dev) ||
 463                     parsed->minor != minor(stb.st_dev))
 464                         return false;
 465                 return true;
 466         case FSID_NUM:
 467                 if (((exp->m_export.e_flags & NFSEXP_FSID) == 0 ||
 468                      exp->m_export.e_fsid != parsed->fsidnum))
 469                         return false;
 470                 return true;
 471         case FSID_UUID4_INUM:
 472         case FSID_UUID16_INUM:
 473                 if (stb.st_ino != parsed->inode)
 474                         return false;
 475                 goto check_uuid;
 476         case FSID_UUID8:
 477         case FSID_UUID16:
 478                 if (!is_mountpoint(path))
 479                         return false;
 480         check_uuid:
 481                 if (exp->m_export.e_uuid)
 482                         get_uuid(exp->m_export.e_uuid, parsed->uuidlen, u);
 483                 else
 484                         for (type = 0;
 485                              uuid_by_path(path, type, parsed->uuidlen, u);
 486                              type++)
 487                                 if (memcmp(u, parsed->fhuuid, parsed->uuidlen) == 0)
 488                                         return true;
 489
 490                 if (memcmp(u, parsed->fhuuid, parsed->uuidlen) != 0)
 491                         return false;
 492                 return true;
 493         }
 494         /* Well, unreachable, actually: */
 495         return false;
 496 }
 497
 498 static void nfsd_fh(FILE *f)
 499 {
 500         /* request are:
 501          *  domain fsidtype fsid
 502          * interpret fsid, find export point and options, and write:
 503          *  domain fsidtype fsid expiry path
 504          */
 505         char *cp;
 506         char *dom;
 507         int fsidtype;
 508         int fsidlen;
 509         char fsid[32];
 510         struct parsed_fsid parsed;
 511         struct exportent *found = NULL;
 512         struct addrinfo *ai = NULL;
 513         char *found_path = NULL;
 514         nfs_export *exp;
 515         int i;
 516         int dev_missing = 0;
 517
 518         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
 519                 return;
 520
 521         xlog(D_CALL, "nfsd_fh: inbuf '%s'", lbuf);
 522
 523         cp = lbuf;
 524
 525         dom = malloc(strlen(cp));
 526         if (dom == NULL)
 527                 return;
 528         if (qword_get(&cp, dom, strlen(cp)) <= 0)
 529                 goto out;
 530         if (qword_get_int(&cp, &fsidtype) != 0)
 531                 goto out;
 532         if (fsidtype < 0 || fsidtype > 7)
 533                 goto out; /* unknown type */
 534         if ((fsidlen = qword_get(&cp, fsid, 32)) <= 0)
 535                 goto out;
 536         if (parse_fsid(fsidtype, fsidlen, fsid, &parsed))
 537                 goto out;
 538
 539         auth_reload();
 540
 541         /* Now determine export point for this fsid/domain */
 542         for (i=0 ; i < MCL_MAXTYPES; i++) {
 543                 nfs_export *next_exp;
 544                 for (exp = exportlist[i].p_head; exp; exp = next_exp) {
 545                         char *path;
 546
 547                         if (exp->m_export.e_flags & NFSEXP_CROSSMOUNT) {
 548                                 static nfs_export *prev = NULL;
 549                                 static void *mnt = NULL;
 550
 551                                 if (prev == exp) {
 552                                         /* try a submount */
 553                                         path = next_mnt(&mnt, exp->m_export.e_path);
 554                                         if (!path) {
 555                                                 next_exp = exp->m_next;
 556                                                 prev = NULL;
 557                                                 continue;
 558                                         }
 559                                         next_exp = exp;
 560                                 } else {
 561                                         prev = exp;
 562                                         mnt = NULL;
 563                                         path = exp->m_export.e_path;
 564                                         next_exp = exp;
 565                                 }
 566                         } else {
 567                                 path = exp->m_export.e_path;
 568                                 next_exp = exp->m_next;
 569                         }
 570
 571                         if (!use_ipaddr && !client_member(dom, exp->m_client->m_hostname))
 572                                 continue;
 573                         if (exp->m_export.e_mountpoint &&
 574                             !is_mountpoint(exp->m_export.e_mountpoint[0]?
 575                                            exp->m_export.e_mountpoint:
 576                                            exp->m_export.e_path))
 577                                 dev_missing ++;
 578
 579                         if (!match_fsid(&parsed, exp, path))
 580                                 continue;
 581                         if (use_ipaddr) {
 582                                 if (ai == NULL) {
 583                                         struct addrinfo *tmp;
 584                                         tmp = host_pton(dom);
 585                                         if (tmp == NULL)
 586                                                 goto out;
 587                                         ai = client_resolve(tmp->ai_addr);
 588                                         freeaddrinfo(tmp);
 589                                 }
 590                                 if (!client_check(exp->m_client, ai))
 591                                         continue;
 592                         }
 593                         if (!found || subexport(&exp->m_export, found)) {
 594                                 found = &exp->m_export;
 595                                 free(found_path);
 596                                 found_path = strdup(path);
 597                                 if (found_path == NULL)
 598                                         goto out;
 599                         } else if (strcmp(found->e_path, exp->m_export.e_path) != 0
 600                                    && !subexport(found, &exp->m_export))
 601                         {
 602                                 xlog(L_WARNING, "%s and %s have same filehandle for %s, using first",
 603                                      found_path, path, dom);
 604                         } else {
 605                                 /* same path, if one is V4ROOT, choose the other */
 606                                 if (found->e_flags & NFSEXP_V4ROOT) {
 607                                         found = &exp->m_export;
 608                                         free(found_path);
 609                                         found_path = strdup(path);
 610                                         if (found_path == NULL)
 611                                                 goto out;
 612                                 }
 613                         }
 614                 }
 615         }
 616         if (found &&
 617             found->e_mountpoint &&
 618             !is_mountpoint(found->e_mountpoint[0]?
 619                            found->e_mountpoint:
 620                            found->e_path)) {
 621                 /* Cannot export this yet
 622                  * should log a warning, but need to rate limit
 623                    xlog(L_WARNING, "%s not exported as %d not a mountpoint",
 624                    found->e_path, found->e_mountpoint);
 625                  */
 626                 /* FIXME we need to make sure we re-visit this later */
 627                 goto out;
 628         }
 629         if (!found && dev_missing) {
 630                 /* The missing dev could be what we want, so just be
 631                  * quite rather than returning stale yet
 632                  */
 633                 goto out;
 634         }
 635
 636         if (found)
 637                 if (cache_export_ent(dom, found, found_path) < 0)
 638                         found = 0;
 639
 640         qword_print(f, dom);
 641         qword_printint(f, fsidtype);
 642         qword_printhex(f, fsid, fsidlen);
 643         /* The fsid -> path lookup can be quite expensive as it
 644          * potentially stats and reads lots of devices, and some of those
 645          * might have spun-down.  The Answer is not likely to
 646          * change underneath us, and an 'exportfs -f' can always
 647          * remove this from the kernel, so use a really log
 648          * timeout.  Maybe this should be configurable on the command
 649          * line.
 650          */
 651         qword_printint(f, 0x7fffffff);
 652         if (found)
 653                 qword_print(f, found_path);
 654         qword_eol(f);
 655  out:
 656         if (found_path)
 657                 free(found_path);
 658         freeaddrinfo(ai);
 659         free(dom);
 660         xlog(D_CALL, "nfsd_fh: found %p path %s", found, found ? found->e_path : NULL);
 661         return;
 662 }
 663
 664 static void write_fsloc(FILE *f, struct exportent *ep)
 665 {
 666         struct servers *servers;
 667
 668         if (ep->e_fslocmethod == FSLOC_NONE)
 669                 return;
 670
 671         servers = replicas_lookup(ep->e_fslocmethod, ep->e_fslocdata);
 672         if (!servers)
 673                 return;
 674         qword_print(f, "fsloc");
 675         qword_printint(f, servers->h_num);
 676         if (servers->h_num >= 0) {
 677                 int i;
 678                 for (i=0; i<servers->h_num; i++) {
 679                         qword_print(f, servers->h_mp[i]->h_host);
 680                         qword_print(f, servers->h_mp[i]->h_path);
 681                 }
 682         }
 683         qword_printint(f, servers->h_referral);
 684         release_replicas(servers);
 685 }
 686
 687 static void write_secinfo(FILE *f, struct exportent *ep, int flag_mask)
 688 {
 689         struct sec_entry *p;
 690
 691         for (p = ep->e_secinfo; p->flav; p++)
 692                 ; /* Do nothing */
 693         if (p == ep->e_secinfo) {
 694                 /* There was no sec= option */
 695                 return;
 696         }
 697         qword_print(f, "secinfo");
 698         qword_printint(f, p - ep->e_secinfo);
 699         for (p = ep->e_secinfo; p->flav; p++) {
 700                 qword_printint(f, p->flav->fnum);
 701                 qword_printint(f, p->flags & flag_mask);
 702         }
 703
 704 }
 705
 706 static int dump_to_cache(FILE *f, char *domain, char *path, struct exportent *exp)
 707 {
 708         qword_print(f, domain);
 709         qword_print(f, path);
 710         if (exp) {
 711                 int different_fs = strcmp(path, exp->e_path) != 0;
 712                 int flag_mask = different_fs ? ~NFSEXP_FSID : ~0;
 713
 714                 qword_printuint(f, time(0) + exp->e_ttl);
 715                 qword_printint(f, exp->e_flags & flag_mask);
 716                 qword_printint(f, exp->e_anonuid);
 717                 qword_printint(f, exp->e_anongid);
 718                 qword_printint(f, exp->e_fsid);
 719                 write_fsloc(f, exp);
 720                 write_secinfo(f, exp, flag_mask);
 721                 if (exp->e_uuid == NULL || different_fs) {
 722                         char u[16];
 723                         if (uuid_by_path(path, 0, 16, u)) {
 724                                 qword_print(f, "uuid");
 725                                 qword_printhex(f, u, 16);
 726                         }
 727                 } else {
 728                         char u[16];
 729                         get_uuid(exp->e_uuid, 16, u);
 730                         qword_print(f, "uuid");
 731                         qword_printhex(f, u, 16);
 732                 }
 733         } else
 734                 qword_printuint(f, time(0) + DEFAULT_TTL);
 735         return qword_eol(f);
 736 }
 737
 738 static int is_subdirectory(char *child, char *parent)
 739 {
 740         int l = strlen(parent);
 741
 742         return strcmp(child, parent) == 0
 743                 || (strncmp(child, parent, l) == 0 && child[l] == '/');
 744 }
 745
 746 static int path_matches(nfs_export *exp, char *path)
 747 {
 748         if (exp->m_export.e_flags & NFSEXP_CROSSMOUNT)
 749                 return is_subdirectory(path, exp->m_export.e_path);
 750         return strcmp(path, exp->m_export.e_path) == 0;
 751 }
 752
 753 static int
 754 client_matches(nfs_export *exp, char *dom, struct addrinfo *ai)
 755 {
 756         if (use_ipaddr)
 757                 return client_check(exp->m_client, ai);
 758         return client_member(dom, exp->m_client->m_hostname);
 759 }
 760
 761 static int
 762 export_matches(nfs_export *exp, char *dom, char *path, struct addrinfo *ai)
 763 {
 764         return path_matches(exp, path) && client_matches(exp, dom, ai);
 765 }
 766
 767 static nfs_export *
 768 lookup_export(char *dom, char *path, struct addrinfo *ai)
 769 {
 770         nfs_export *exp;
 771         nfs_export *found = NULL;
 772         int found_type = 0;
 773         int i;
 774
 775         for (i=0 ; i < MCL_MAXTYPES; i++) {
 776                 for (exp = exportlist[i].p_head; exp; exp = exp->m_next) {
 777                         if (!export_matches(exp, dom, path, ai))
 778                                 continue;
 779                         if (!found) {
 780                                 found = exp;
 781                                 found_type = i;
 782                                 continue;
 783                         }
 784                         /* Always prefer non-V4ROOT exports */
 785                         if (exp->m_export.e_flags & NFSEXP_V4ROOT)
 786                                 continue;
 787                         if (found->m_export.e_flags & NFSEXP_V4ROOT) {
 788                                 found = exp;
 789                                 found_type = i;
 790                                 continue;
 791                         }
 792
 793                         /* If one is a CROSSMOUNT, then prefer the longest path */
 794                         if (((found->m_export.e_flags & NFSEXP_CROSSMOUNT) ||
 795                              (exp->m_export.e_flags & NFSEXP_CROSSMOUNT)) &&
 796                             strlen(found->m_export.e_path) !=
 797                             strlen(exp->m_export.e_path)) {
 798
 799                                 if (strlen(exp->m_export.e_path) >
 800                                     strlen(found->m_export.e_path)) {
 801                                         found = exp;
 802                                         found_type = i;
 803                                 }
 804                                 continue;
 805
 806                         } else if (found_type == i && found->m_warned == 0) {
 807                                 xlog(L_WARNING, "%s exported to both %s and %s, "
 808                                      "arbitrarily choosing options from first",
 809                                      path, found->m_client->m_hostname, exp->m_client->m_hostname,
 810                                      dom);
 811                                 found->m_warned = 1;
 812                         }
 813                 }
 814         }
 815         return found;
 816 }
 817
 818 #ifdef HAVE_NFS_PLUGIN_H
 819 #include <dlfcn.h>
 820 #include <nfs-plugin.h>
 821
 822 /*
 823  * Walk through a set of FS locations and build a set of export options.
 824  * Returns true if all went to plan; otherwise, false.
 825  */
 826 static _Bool
 827 locations_to_options(struct jp_ops *ops, nfs_fsloc_set_t locations,
 828                 char *options, size_t remaining, int *ttl)
 829 {
 830         char *server, *last_path, *rootpath, *ptr;
 831         _Bool seen = false;
 832
 833         last_path = NULL;
 834         rootpath = NULL;
 835         server = NULL;
 836         ptr = options;
 837         *ttl = 0;
 838
 839         for (;;) {
 840                 enum jp_status status;
 841                 int len;
 842
 843                 status = ops->jp_get_next_location(locations, &server,
 844                                                         &rootpath, ttl);
 845                 if (status == JP_EMPTY)
 846                         break;
 847                 if (status != JP_OK) {
 848                         xlog(D_GENERAL, "%s: failed to parse location: %s",
 849                                 __func__, ops->jp_error(status));
 850                         goto out_false;
 851                 }
 852                 xlog(D_GENERAL, "%s: Location: %s:%s",
 853                         __func__, server, rootpath);
 854
 855                 if (last_path && strcmp(rootpath, last_path) == 0) {
 856                         len = snprintf(ptr, remaining, "+%s", server);
 857                         if (len < 0) {
 858                                 xlog(D_GENERAL, "%s: snprintf: %m", __func__);
 859                                 goto out_false;
 860                         }
 861                         if ((size_t)len >= remaining) {
 862                                 xlog(D_GENERAL, "%s: options buffer overflow", __func__);
 863                                 goto out_false;
 864                         }
 865                         remaining -= (size_t)len;
 866                         ptr += len;
 867                 } else {
 868                         if (last_path == NULL)
 869                                 len = snprintf(ptr, remaining, "refer=%s@%s",
 870                                                         rootpath, server);
 871                         else
 872                                 len = snprintf(ptr, remaining, ":%s@%s",
 873                                                         rootpath, server);
 874                         if (len < 0) {
 875                                 xlog(D_GENERAL, "%s: snprintf: %m", __func__);
 876                                 goto out_false;
 877                         }
 878                         if ((size_t)len >= remaining) {
 879                                 xlog(D_GENERAL, "%s: options buffer overflow",
 880                                         __func__);
 881                                 goto out_false;
 882                         }
 883                         remaining -= (size_t)len;
 884                         ptr += len;
 885                         last_path = rootpath;
 886                 }
 887
 888                 seen = true;
 889                 free(rootpath);
 890                 free(server);
 891         }
 892
 893         xlog(D_CALL, "%s: options='%s', ttl=%d",
 894                 __func__, options, *ttl);
 895         return seen;
 896
 897 out_false:
 898         free(rootpath);
 899         free(server);
 900         return false;
 901 }
 902
 903 /*
 904  * Walk through the set of FS locations and build an exportent.
 905  * Returns pointer to an exportent if "junction" refers to a junction.
 906  *
 907  * Returned exportent points to static memory.
 908  */
 909 static struct exportent *do_locations_to_export(struct jp_ops *ops,
 910                 nfs_fsloc_set_t locations, const char *junction,
 911                 char *options, size_t options_len)
 912 {
 913         struct exportent *exp;
 914         int ttl;
 915
 916         if (!locations_to_options(ops, locations, options, options_len, &ttl))
 917                 return NULL;
 918
 919         exp = mkexportent("*", (char *)junction, options);
 920         if (exp == NULL) {
 921                 xlog(L_ERROR, "%s: Failed to construct exportent", __func__);
 922                 return NULL;
 923         }
 924
 925         exp->e_uuid = NULL;
 926         exp->e_ttl = ttl;
 927         return exp;
 928 }
 929
 930 /*
 931  * Convert set of FS locations to an exportent.  Returns pointer to
 932  * an exportent if "junction" refers to a junction.
 933  *
 934  * Returned exportent points to static memory.
 935  */
 936 static struct exportent *locations_to_export(struct jp_ops *ops,
 937                 nfs_fsloc_set_t locations, const char *junction)
 938 {
 939         struct exportent *exp;
 940         char *options;
 941
 942         options = malloc(BUFSIZ);
 943         if (options == NULL) {
 944                 xlog(D_GENERAL, "%s: failed to allocate options buffer",
 945                         __func__);
 946                 return NULL;
 947         }
 948         options[0] = '\0';
 949
 950         exp = do_locations_to_export(ops, locations, junction,
 951                                                 options, BUFSIZ);
 952
 953         free(options);
 954         return exp;
 955 }
 956
 957 /*
 958  * Retrieve locations information in "junction" and dump it to the
 959  * kernel.  Returns pointer to an exportent if "junction" refers
 960  * to a junction.
 961  *
 962  * Returned exportent points to static memory.
 963  */
 964 static struct exportent *invoke_junction_ops(void *handle,
 965                 const char *junction)
 966 {
 967         nfs_fsloc_set_t locations;
 968         struct exportent *exp;
 969         enum jp_status status;
 970         struct jp_ops *ops;
 971         char *error;
 972
 973         ops = (struct jp_ops *)dlsym(handle, "nfs_junction_ops");
 974         error = dlerror();
 975         if (error != NULL) {
 976                 xlog(D_GENERAL, "%s: dlsym(jp_junction_ops): %s",
 977                         __func__, error);
 978                 return NULL;
 979         }
 980         if (ops->jp_api_version != JP_API_VERSION) {
 981                 xlog(D_GENERAL, "%s: unrecognized junction API version: %u",
 982                         __func__, ops->jp_api_version);
 983                 return NULL;
 984         }
 985
 986         status = ops->jp_init(false);
 987         if (status != JP_OK) {
 988                 xlog(D_GENERAL, "%s: failed to resolve %s: %s",
 989                         __func__, junction, ops->jp_error(status));
 990                 return NULL;
 991         }
 992
 993         status = ops->jp_get_locations(junction, &locations);
 994         if (status != JP_OK) {
 995                 xlog(D_GENERAL, "%s: failed to resolve %s: %s",
 996                         __func__, junction, ops->jp_error(status));
 997                 return NULL;
 998         }
 999
1000         exp = locations_to_export(ops, locations, junction);
1001
1002         ops->jp_put_locations(locations);
1003         ops->jp_done();
1004         return exp;
1005 }
1006
1007 /*
1008  * Load the junction plug-in, then try to resolve "pathname".
1009  * Returns pointer to an initialized exportent if "junction"
1010  * refers to a junction, or NULL if not.
1011  *
1012  * Returned exportent points to static memory.
1013  */
1014 static struct exportent *lookup_junction(const char *pathname)
1015 {
1016         struct exportent *exp;
1017         void *handle;
1018
1019         handle = dlopen("libnfsjunct.so", RTLD_NOW);
1020         if (handle == NULL) {
1021                 xlog(D_GENERAL, "%s: dlopen: %s", __func__, dlerror());
1022                 return NULL;
1023         }
1024         (void)dlerror();        /* Clear any error */
1025
1026         exp = invoke_junction_ops(handle, pathname);
1027
1028         /* We could leave it loaded to make junction resolution
1029          * faster next time.  However, if we want to replace the
1030          * library, that would require restarting mountd. */
1031         (void)dlclose(handle);
1032         return exp;
1033 }
1034 #else   /* !HAVE_NFS_PLUGIN_H */
1035 static inline struct exportent *lookup_junction(const char *UNUSED(pathname))
1036 {
1037         return NULL;
1038 }
1039 #endif  /* !HAVE_NFS_PLUGIN_H */
1040
1041 static void nfsd_export(FILE *f)
1042 {
1043         /* requests are:
1044          *  domain path
1045          * determine export options and return:
1046          *  domain path expiry flags anonuid anongid fsid
1047          */
1048
1049         char *cp;
1050         char *dom, *path;
1051         nfs_export *found = NULL;
1052         struct addrinfo *ai = NULL;
1053
1054         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
1055                 return;
1056
1057         xlog(D_CALL, "nfsd_export: inbuf '%s'", lbuf);
1058
1059         cp = lbuf;
1060         dom = malloc(strlen(cp));
1061         path = malloc(strlen(cp));
1062
1063         if (!dom || !path)
1064                 goto out;
1065
1066         if (qword_get(&cp, dom, strlen(lbuf)) <= 0)
1067                 goto out;
1068         if (qword_get(&cp, path, strlen(lbuf)) <= 0)
1069                 goto out;
1070
1071         auth_reload();
1072
1073         if (use_ipaddr) {
1074                 struct addrinfo *tmp;
1075                 tmp = host_pton(dom);
1076                 if (tmp == NULL)
1077                         goto out;
1078                 ai = client_resolve(tmp->ai_addr);
1079                 freeaddrinfo(tmp);
1080                         goto out;
1081         }
1082
1083         found = lookup_export(dom, path, ai);
1084
1085         if (found) {
1086                 if (dump_to_cache(f, dom, path, &found->m_export) < 0) {
1087                         xlog(L_WARNING,
1088                              "Cannot export %s, possibly unsupported filesystem"
1089                              " or fsid= required", path);
1090                         dump_to_cache(f, dom, path, NULL);
1091                 }
1092         } else {
1093                 dump_to_cache(f, dom, path, lookup_junction(path));
1094         }
1095  out:
1096         xlog(D_CALL, "nfsd_export: found %p path %s", found, path ? path : NULL);
1097         if (dom) free(dom);
1098         if (path) free(path);
1099         freeaddrinfo(ai);
1100 }
1101
1102
1103 struct {
1104         char *cache_name;
1105         void (*cache_handle)(FILE *f);
1106         FILE *f;
1107         char vbuf[RPC_CHAN_BUF_SIZE];
1108 } cachelist[] = {
1109         { "auth.unix.ip", auth_unix_ip, NULL, ""},
1110         { "auth.unix.gid", auth_unix_gid, NULL, ""},
1111         { "nfsd.export", nfsd_export, NULL, ""},
1112         { "nfsd.fh", nfsd_fh, NULL, ""},
1113         { NULL, NULL, NULL, ""}
1114 };
1115
1116 extern int manage_gids;
1117
1118 /**
1119  * cache_open - prepare communications channels with kernel RPC caches
1120  *
1121  */
1122 void cache_open(void)
1123 {
1124         int i;
1125         for (i=0; cachelist[i].cache_name; i++ ) {
1126                 char path[100];
1127                 if (!manage_gids && cachelist[i].cache_handle == auth_unix_gid)
1128                         continue;
1129                 sprintf(path, "/proc/net/rpc/%s/channel", cachelist[i].cache_name);
1130                 cachelist[i].f = fopen(path, "r+");
1131                 if (cachelist[i].f != NULL) {
1132                         setvbuf(cachelist[i].f, cachelist[i].vbuf, _IOLBF,
1133                                 RPC_CHAN_BUF_SIZE);
1134                 }
1135         }
1136 }
1137
1138 /**
1139  * cache_set_fds - prepare cache file descriptors for one iteration of the service loop
1140  * @fdset: pointer to fd_set to prepare
1141  */
1142 void cache_set_fds(fd_set *fdset)
1143 {
1144         int i;
1145         for (i=0; cachelist[i].cache_name; i++) {
1146                 if (cachelist[i].f)
1147                         FD_SET(fileno(cachelist[i].f), fdset);
1148         }
1149 }
1150
1151 /**
1152  * cache_process_req - process any active cache file descriptors during service loop iteration
1153  * @fdset: pointer to fd_set to examine for activity
1154  */
1155 int cache_process_req(fd_set *readfds)
1156 {
1157         int i;
1158         int cnt = 0;
1159         for (i=0; cachelist[i].cache_name; i++) {
1160                 if (cachelist[i].f != NULL &&
1161                     FD_ISSET(fileno(cachelist[i].f), readfds)) {
1162                         cnt++;
1163                         cachelist[i].cache_handle(cachelist[i].f);
1164                         FD_CLR(fileno(cachelist[i].f), readfds);
1165                 }
1166         }
1167         return cnt;
1168 }
1169
1170
1171 /*
1172  * Give IP->domain and domain+path->options to kernel
1173  * % echo nfsd $IP  $[now+DEFAULT_TTL] $domain > /proc/net/rpc/auth.unix.ip/channel
1174  * % echo $domain $path $[now+DEFAULT_TTL] $options $anonuid $anongid $fsid > /proc/net/rpc/nfsd.export/channel
1175  */
1176
1177 static int cache_export_ent(char *domain, struct exportent *exp, char *path)
1178 {
1179         int err;
1180         FILE *f = fopen("/proc/net/rpc/nfsd.export/channel", "w");
1181         if (!f)
1182                 return -1;
1183
1184         err = dump_to_cache(f, domain, exp->e_path, exp);
1185         if (err) {
1186                 xlog(L_WARNING,
1187                      "Cannot export %s, possibly unsupported filesystem or"
1188                      " fsid= required", exp->e_path);
1189         }
1190
1191         while (err == 0 && (exp->e_flags & NFSEXP_CROSSMOUNT) && path) {
1192                 /* really an 'if', but we can break out of
1193                  * a 'while' more easily */
1194                 /* Look along 'path' for other filesystems
1195                  * and export them with the same options
1196                  */
1197                 struct stat stb;
1198                 size_t l = strlen(exp->e_path);
1199                 __dev_t dev;
1200
1201                 if (strlen(path) <= l || path[l] != '/' ||
1202                     strncmp(exp->e_path, path, l) != 0)
1203                         break;
1204                 if (stat(exp->e_path, &stb) != 0)
1205                         break;
1206                 dev = stb.st_dev;
1207                 while(path[l] == '/') {
1208                         char c;
1209                         /* errors for submount should fail whole filesystem */
1210                         int err2;
1211
1212                         l++;
1213                         while (path[l] != '/' && path[l])
1214                                 l++;
1215                         c = path[l];
1216                         path[l] = 0;
1217                         err2 = lstat(path, &stb);
1218                         path[l] = c;
1219                         if (err2 < 0)
1220                                 break;
1221                         if (stb.st_dev == dev)
1222                                 continue;
1223                         dev = stb.st_dev;
1224                         path[l] = 0;
1225                         dump_to_cache(f, domain, path, exp);
1226                         path[l] = c;
1227                 }
1228                 break;
1229         }
1230
1231         fclose(f);
1232         return err;
1233 }
1234
1235 /**
1236  * cache_export - Inform kernel of a new nfs_export
1237  * @exp: target nfs_export
1238  * @path: NUL-terminated C string containing export path
1239  */
1240 int cache_export(nfs_export *exp, char *path)
1241 {
1242         char buf[INET6_ADDRSTRLEN];
1243         int err;
1244         FILE *f;
1245
1246         f = fopen("/proc/net/rpc/auth.unix.ip/channel", "w");
1247         if (!f)
1248                 return -1;
1249
1250
1251         qword_print(f, "nfsd");
1252         qword_print(f,
1253                 host_ntop(get_addrlist(exp->m_client, 0), buf, sizeof(buf)));
1254         qword_printuint(f, time(0) + exp->m_export.e_ttl);
1255         qword_print(f, exp->m_client->m_hostname);
1256         err = qword_eol(f);
1257
1258         fclose(f);
1259
1260         err = cache_export_ent(exp->m_client->m_hostname, &exp->m_export, path)
1261                 || err;
1262         return err;
1263 }
1264
1265 /**
1266  * cache_get_filehandle - given an nfs_export, get its root filehandle
1267  * @exp: target nfs_export
1268  * @len: length of requested file handle
1269  * @p: NUL-terminated C string containing export path
1270  *
1271  * Returns pointer to NFS file handle of root directory of export
1272  *
1273  * {
1274  *   echo $domain $path $length
1275  *   read filehandle <&0
1276  * } <> /proc/fs/nfsd/filehandle
1277  */
1278 struct nfs_fh_len *
1279 cache_get_filehandle(nfs_export *exp, int len, char *p)
1280 {
1281         FILE *f = fopen("/proc/fs/nfsd/filehandle", "r+");
1282         char buf[200];
1283         char *bp = buf;
1284         int failed;
1285         static struct nfs_fh_len fh;
1286
1287         if (!f)
1288                 f = fopen("/proc/fs/nfs/filehandle", "r+");
1289         if (!f)
1290                 return NULL;
1291
1292         qword_print(f, exp->m_client->m_hostname);
1293         qword_print(f, p);
1294         qword_printint(f, len);
1295         failed = qword_eol(f);
1296
1297         if (!failed)
1298                 failed = (fgets(buf, sizeof(buf), f) == NULL);
1299         fclose(f);
1300         if (failed)
1301                 return NULL;
1302         memset(fh.fh_handle, 0, sizeof(fh.fh_handle));
1303         fh.fh_size = qword_get(&bp, (char *)fh.fh_handle, NFS3_FHSIZE);
1304         return &fh;
1305 }