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
  68 char *lbuf  = NULL;
  69 int lbuflen = 0;
  70 extern int use_ipaddr;
  71
  72 static void auth_unix_ip(FILE *f)
  73 {
  74         /* requests are
  75          *  class IP-ADDR
  76          * Ignore if class != "nfsd"
  77          * Otherwise find domainname and write back:
  78          *
  79          *  "nfsd" IP-ADDR expiry domainname
  80          */
  81         char *cp;
  82         char class[20];
  83         char ipaddr[INET6_ADDRSTRLEN];
  84         char *client = NULL;
  85         struct addrinfo *tmp = NULL;
  86         struct addrinfo *ai = NULL;
  87         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
  88                 return;
  89
  90         xlog(D_CALL, "auth_unix_ip: inbuf '%s'", lbuf);
  91
  92         cp = lbuf;
  93
  94         if (qword_get(&cp, class, 20) <= 0 ||
  95             strcmp(class, "nfsd") != 0)
  96                 return;
  97
  98         if (qword_get(&cp, ipaddr, sizeof(ipaddr)) <= 0)
  99                 return;
 100
 101         tmp = host_pton(ipaddr);
 102         if (tmp == NULL)
 103                 return;
 104
 105         auth_reload();
 106
 107         /* addr is a valid, interesting address, find the domain name... */
 108         if (!use_ipaddr) {
 109                 ai = client_resolve(tmp->ai_addr);
 110                 client = client_compose(ai);
 111                 freeaddrinfo(ai);
 112         }
 113         freeaddrinfo(tmp);
 114
 115         qword_print(f, "nfsd");
 116         qword_print(f, ipaddr);
 117         qword_printint(f, time(0)+30*60);
 118         if (use_ipaddr)
 119                 qword_print(f, ipaddr);
 120         else if (client)
 121                 qword_print(f, *client?client:"DEFAULT");
 122         qword_eol(f);
 123         xlog(D_CALL, "auth_unix_ip: client %p '%s'", client, client?client: "DEFAULT");
 124
 125         free(client);
 126 }
 127
 128 static void auth_unix_gid(FILE *f)
 129 {
 130         /* Request are
 131          *  uid
 132          * reply is
 133          *  uid expiry count list of group ids
 134          */
 135         uid_t uid;
 136         struct passwd *pw;
 137         gid_t glist[100], *groups = glist;
 138         int ngroups = 100;
 139         int rv, i;
 140         char *cp;
 141
 142         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
 143                 return;
 144
 145         cp = lbuf;
 146         if (qword_get_uint(&cp, &uid) != 0)
 147                 return;
 148
 149         pw = getpwuid(uid);
 150         if (!pw)
 151                 rv = -1;
 152         else {
 153                 rv = getgrouplist(pw->pw_name, pw->pw_gid, groups, &ngroups);
 154                 if (rv == -1 && ngroups >= 100) {
 155                         groups = malloc(sizeof(gid_t)*ngroups);
 156                         if (!groups)
 157                                 rv = -1;
 158                         else
 159                                 rv = getgrouplist(pw->pw_name, pw->pw_gid,
 160                                                   groups, &ngroups);
 161                 }
 162         }
 163         qword_printuint(f, uid);
 164         qword_printuint(f, time(0)+30*60);
 165         if (rv >= 0) {
 166                 qword_printuint(f, ngroups);
 167                 for (i=0; i<ngroups; i++)
 168                         qword_printuint(f, groups[i]);
 169         } else
 170                 qword_printuint(f, 0);
 171         qword_eol(f);
 172
 173         if (groups != glist)
 174                 free(groups);
 175 }
 176
 177 #if USE_BLKID
 178 static const char *get_uuid_blkdev(char *path)
 179 {
 180         /* We set *safe if we know that we need the
 181          * fsid from statfs too.
 182          */
 183         static blkid_cache cache = NULL;
 184         struct stat stb;
 185         char *devname;
 186         blkid_tag_iterate iter;
 187         blkid_dev dev;
 188         const char *type;
 189         const char *val, *uuid = NULL;
 190
 191         if (cache == NULL)
 192                 blkid_get_cache(&cache, NULL);
 193
 194         if (stat(path, &stb) != 0)
 195                 return NULL;
 196         devname = blkid_devno_to_devname(stb.st_dev);
 197         if (!devname)
 198                 return NULL;
 199         dev = blkid_get_dev(cache, devname, BLKID_DEV_NORMAL);
 200         free(devname);
 201         if (!dev)
 202                 return NULL;
 203         iter = blkid_tag_iterate_begin(dev);
 204         if (!iter)
 205                 return NULL;
 206         while (blkid_tag_next(iter, &type, &val) == 0) {
 207                 if (strcmp(type, "UUID") == 0)
 208                         uuid = val;
 209                 if (strcmp(type, "TYPE") == 0 &&
 210                     strcmp(val, "btrfs") == 0) {
 211                         uuid = NULL;
 212                         break;
 213                 }
 214         }
 215         blkid_tag_iterate_end(iter);
 216         return uuid;
 217 }
 218 #else
 219 #define get_uuid_blkdev(path) (NULL)
 220 #endif
 221
 222 static int get_uuid(const char *val, int uuidlen, char *u)
 223 {
 224         /* extract hex digits from uuidstr and compose a uuid
 225          * of the given length (max 16), xoring bytes to make
 226          * a smaller uuid.
 227          */
 228         int i = 0;
 229
 230         memset(u, 0, uuidlen);
 231         for ( ; *val ; val++) {
 232                 char c = *val;
 233                 if (!isxdigit(c))
 234                         continue;
 235                 if (isalpha(c)) {
 236                         if (isupper(c))
 237                                 c = c - 'A' + 10;
 238                         else
 239                                 c = c - 'a' + 10;
 240                 } else
 241                         c = c - '0' + 0;
 242                 if ((i&1) == 0)
 243                         c <<= 4;
 244                 u[i/2] ^= c;
 245                 i++;
 246                 if (i == uuidlen*2)
 247                         i = 0;
 248         }
 249         return 1;
 250 }
 251
 252 static int uuid_by_path(char *path, int type, int uuidlen, char *uuid)
 253 {
 254         /* get a uuid for the filesystem found at 'path'.
 255          * There are several possible ways of generating the
 256          * uuids (types).
 257          * Type 0 is used for new filehandles, while other types
 258          * may be used to interpret old filehandle - to ensure smooth
 259          * forward migration.
 260          * We return 1 if a uuid was found (and it might be worth
 261          * trying the next type) or 0 if no more uuid types can be
 262          * extracted.
 263          */
 264
 265         /* Possible sources of uuid are
 266          * - blkid uuid
 267          * - statfs64 uuid
 268          *
 269          * On some filesystems (e.g. vfat) the statfs64 uuid is simply an
 270          * encoding of the device that the filesystem is mounted from, so
 271          * it we be very bad to use that (as device numbers change).  blkid
 272          * must be preferred.
 273          * On other filesystems (e.g. btrfs) the statfs64 uuid contains
 274          * important info that the blkid uuid cannot contain:  This happens
 275          * when multiple subvolumes are exported (they have the same
 276          * blkid uuid but different statfs64 uuids).
 277          * We rely on get_uuid_blkdev *knowing* which is which and not returning
 278          * a uuid for filesystems where the statfs64 uuid is better.
 279          *
 280          */
 281         struct statfs64 st;
 282         char fsid_val[17];
 283         const char *blkid_val;
 284         const char *val;
 285
 286         blkid_val = get_uuid_blkdev(path);
 287
 288         if (statfs64(path, &st) == 0 &&
 289             (st.f_fsid.__val[0] || st.f_fsid.__val[1]))
 290                 snprintf(fsid_val, 17, "%08x%08x",
 291                          st.f_fsid.__val[0], st.f_fsid.__val[1]);
 292         else
 293                 fsid_val[0] = 0;
 294
 295         if (blkid_val && (type--) == 0)
 296                 val = blkid_val;
 297         else if (fsid_val[0] && (type--) == 0)
 298                 val = fsid_val;
 299         else
 300                 return 0;
 301
 302         get_uuid(val, uuidlen, uuid);
 303         return 1;
 304 }
 305
 306 /* Iterate through /etc/mtab, finding mountpoints
 307  * at or below a given path
 308  */
 309 static char *next_mnt(void **v, char *p)
 310 {
 311         FILE *f;
 312         struct mntent *me;
 313         int l = strlen(p);
 314         if (*v == NULL) {
 315                 f = setmntent("/etc/mtab", "r");
 316                 *v = f;
 317         } else
 318                 f = *v;
 319         while ((me = getmntent(f)) != NULL &&
 320                (strncmp(me->mnt_dir, p, l) != 0 ||
 321                 me->mnt_dir[l] != '/'))
 322                 ;
 323         if (me == NULL) {
 324                 endmntent(f);
 325                 *v = NULL;
 326                 return NULL;
 327         }
 328         return me->mnt_dir;
 329 }
 330
 331 static void nfsd_fh(FILE *f)
 332 {
 333         /* request are:
 334          *  domain fsidtype fsid
 335          * interpret fsid, find export point and options, and write:
 336          *  domain fsidtype fsid expiry path
 337          */
 338         char *cp;
 339         char *dom;
 340         int fsidtype;
 341         int fsidlen;
 342         unsigned int dev, major=0, minor=0;
 343         unsigned int inode=0;
 344         unsigned long long inode64;
 345         unsigned int fsidnum=0;
 346         char fsid[32];
 347         struct exportent *found = NULL;
 348         struct addrinfo *ai = NULL;
 349         char *found_path = NULL;
 350         nfs_export *exp;
 351         int i;
 352         int dev_missing = 0;
 353         int uuidlen = 0;
 354         char *fhuuid = NULL;
 355
 356         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
 357                 return;
 358
 359         xlog(D_CALL, "nfsd_fh: inbuf '%s'", lbuf);
 360
 361         cp = lbuf;
 362
 363         dom = malloc(strlen(cp));
 364         if (dom == NULL)
 365                 return;
 366         if (qword_get(&cp, dom, strlen(cp)) <= 0)
 367                 goto out;
 368         if (qword_get_int(&cp, &fsidtype) != 0)
 369                 goto out;
 370         if (fsidtype < 0 || fsidtype > 7)
 371                 goto out; /* unknown type */
 372         if ((fsidlen = qword_get(&cp, fsid, 32)) <= 0)
 373                 goto out;
 374         switch(fsidtype) {
 375         case FSID_DEV: /* 4 bytes: 2 major, 2 minor, 4 inode */
 376                 if (fsidlen != 8)
 377                         goto out;
 378                 memcpy(&dev, fsid, 4);
 379                 memcpy(&inode, fsid+4, 4);
 380                 major = ntohl(dev)>>16;
 381                 minor = ntohl(dev) & 0xFFFF;
 382                 break;
 383
 384         case FSID_NUM: /* 4 bytes - fsid */
 385                 if (fsidlen != 4)
 386                         goto out;
 387                 memcpy(&fsidnum, fsid, 4);
 388                 break;
 389
 390         case FSID_MAJOR_MINOR: /* 12 bytes: 4 major, 4 minor, 4 inode
 391                  * This format is never actually used but was
 392                  * an historical accident
 393                  */
 394                 if (fsidlen != 12)
 395                         goto out;
 396                 memcpy(&dev, fsid, 4); major = ntohl(dev);
 397                 memcpy(&dev, fsid+4, 4); minor = ntohl(dev);
 398                 memcpy(&inode, fsid+8, 4);
 399                 break;
 400
 401         case FSID_ENCODE_DEV: /* 8 bytes: 4 byte packed device number, 4 inode */
 402                 /* This is *host* endian, not net-byte-order, because
 403                  * no-one outside this host has any business interpreting it
 404                  */
 405                 if (fsidlen != 8)
 406                         goto out;
 407                 memcpy(&dev, fsid, 4);
 408                 memcpy(&inode, fsid+4, 4);
 409                 major = (dev & 0xfff00) >> 8;
 410                 minor = (dev & 0xff) | ((dev >> 12) & 0xfff00);
 411                 break;
 412
 413         case FSID_UUID4_INUM: /* 4 byte inode number and 4 byte uuid */
 414                 if (fsidlen != 8)
 415                         goto out;
 416                 memcpy(&inode, fsid, 4);
 417                 uuidlen = 4;
 418                 fhuuid = fsid+4;
 419                 break;
 420         case FSID_UUID8: /* 8 byte uuid */
 421                 if (fsidlen != 8)
 422                         goto out;
 423                 uuidlen = 8;
 424                 fhuuid = fsid;
 425                 break;
 426         case FSID_UUID16: /* 16 byte uuid */
 427                 if (fsidlen != 16)
 428                         goto out;
 429                 uuidlen = 16;
 430                 fhuuid = fsid;
 431                 break;
 432         case FSID_UUID16_INUM: /* 8 byte inode number and 16 byte uuid */
 433                 if (fsidlen != 24)
 434                         goto out;
 435                 memcpy(&inode64, fsid, 8);
 436                 inode = inode64;
 437                 uuidlen = 16;
 438                 fhuuid = fsid+8;
 439                 break;
 440         }
 441
 442         auth_reload();
 443
 444         /* Now determine export point for this fsid/domain */
 445         for (i=0 ; i < MCL_MAXTYPES; i++) {
 446                 nfs_export *next_exp;
 447                 for (exp = exportlist[i].p_head; exp; exp = next_exp) {
 448                         struct stat stb;
 449                         char u[16];
 450                         char *path;
 451                         int type;
 452
 453                         if (exp->m_export.e_flags & NFSEXP_CROSSMOUNT) {
 454                                 static nfs_export *prev = NULL;
 455                                 static void *mnt = NULL;
 456
 457                                 if (prev == exp) {
 458                                         /* try a submount */
 459                                         path = next_mnt(&mnt, exp->m_export.e_path);
 460                                         if (!path) {
 461                                                 next_exp = exp->m_next;
 462                                                 prev = NULL;
 463                                                 continue;
 464                                         }
 465                                         next_exp = exp;
 466                                 } else {
 467                                         prev = exp;
 468                                         mnt = NULL;
 469                                         path = exp->m_export.e_path;
 470                                         next_exp = exp;
 471                                 }
 472                         } else {
 473                                 path = exp->m_export.e_path;
 474                                 next_exp = exp->m_next;
 475                         }
 476
 477                         if (!use_ipaddr && !client_member(dom, exp->m_client->m_hostname))
 478                                 continue;
 479                         if (exp->m_export.e_mountpoint &&
 480                             !is_mountpoint(exp->m_export.e_mountpoint[0]?
 481                                            exp->m_export.e_mountpoint:
 482                                            exp->m_export.e_path))
 483                                 dev_missing ++;
 484                         if (stat(path, &stb) != 0)
 485                                 continue;
 486                         if (!S_ISDIR(stb.st_mode) && !S_ISREG(stb.st_mode)) {
 487                                 continue;
 488                         }
 489                         switch(fsidtype){
 490                         case FSID_DEV:
 491                         case FSID_MAJOR_MINOR:
 492                         case FSID_ENCODE_DEV:
 493                                 if (stb.st_ino != inode)
 494                                         continue;
 495                                 if (major != major(stb.st_dev) ||
 496                                     minor != minor(stb.st_dev))
 497                                         continue;
 498                                 break;
 499                         case FSID_NUM:
 500                                 if (((exp->m_export.e_flags & NFSEXP_FSID) == 0 ||
 501                                      exp->m_export.e_fsid != fsidnum))
 502                                         continue;
 503                                 break;
 504                         case FSID_UUID4_INUM:
 505                         case FSID_UUID16_INUM:
 506                                 if (stb.st_ino != inode)
 507                                         continue;
 508                                 goto check_uuid;
 509                         case FSID_UUID8:
 510                         case FSID_UUID16:
 511                                 if (!is_mountpoint(path))
 512                                         continue;
 513                         check_uuid:
 514                                 if (exp->m_export.e_uuid)
 515                                         get_uuid(exp->m_export.e_uuid,
 516                                                  uuidlen, u);
 517                                 else
 518                                         for (type = 0;
 519                                              uuid_by_path(path, type, uuidlen, u);
 520                                              type++)
 521                                                 if (memcmp(u, fhuuid, uuidlen) == 0)
 522                                                         break;
 523
 524                                 if (memcmp(u, fhuuid, uuidlen) != 0)
 525                                         continue;
 526                                 break;
 527                         }
 528                         if (use_ipaddr) {
 529                                 if (ai == NULL) {
 530                                         struct addrinfo *tmp;
 531                                         tmp = host_pton(dom);
 532                                         if (tmp == NULL)
 533                                                 goto out;
 534                                         ai = client_resolve(tmp->ai_addr);
 535                                         freeaddrinfo(tmp);
 536                                 }
 537                                 if (!client_check(exp->m_client, ai))
 538                                         continue;
 539                         }
 540                         /* It's a match !! */
 541                         if (!found) {
 542                                 found = &exp->m_export;
 543                                 found_path = strdup(path);
 544                                 if (found_path == NULL)
 545                                         goto out;
 546                         } else if (strcmp(found->e_path, exp->m_export.e_path)!= 0)
 547                         {
 548                                 xlog(L_WARNING, "%s and %s have same filehandle for %s, using first",
 549                                      found_path, path, dom);
 550                         }
 551                 }
 552         }
 553         if (found &&
 554             found->e_mountpoint &&
 555             !is_mountpoint(found->e_mountpoint[0]?
 556                            found->e_mountpoint:
 557                            found->e_path)) {
 558                 /* Cannot export this yet
 559                  * should log a warning, but need to rate limit
 560                    xlog(L_WARNING, "%s not exported as %d not a mountpoint",
 561                    found->e_path, found->e_mountpoint);
 562                  */
 563                 /* FIXME we need to make sure we re-visit this later */
 564                 goto out;
 565         }
 566         if (!found && dev_missing) {
 567                 /* The missing dev could be what we want, so just be
 568                  * quite rather than returning stale yet
 569                  */
 570                 goto out;
 571         }
 572
 573         if (found)
 574                 if (cache_export_ent(dom, found, found_path) < 0)
 575                         found = 0;
 576
 577         qword_print(f, dom);
 578         qword_printint(f, fsidtype);
 579         qword_printhex(f, fsid, fsidlen);
 580         /* The fsid -> path lookup can be quite expensive as it
 581          * potentially stats and reads lots of devices, and some of those
 582          * might have spun-down.  The Answer is not likely to
 583          * change underneath us, and an 'exportfs -f' can always
 584          * remove this from the kernel, so use a really log
 585          * timeout.  Maybe this should be configurable on the command
 586          * line.
 587          */
 588         qword_printint(f, 0x7fffffff);
 589         if (found)
 590                 qword_print(f, found_path);
 591         qword_eol(f);
 592  out:
 593         if (found_path)
 594                 free(found_path);
 595         freeaddrinfo(ai);
 596         free(dom);
 597         xlog(D_CALL, "nfsd_fh: found %p path %s", found, found ? found->e_path : NULL);
 598         return;
 599 }
 600
 601 static void write_fsloc(FILE *f, struct exportent *ep)
 602 {
 603         struct servers *servers;
 604
 605         if (ep->e_fslocmethod == FSLOC_NONE)
 606                 return;
 607
 608         servers = replicas_lookup(ep->e_fslocmethod, ep->e_fslocdata);
 609         if (!servers)
 610                 return;
 611         qword_print(f, "fsloc");
 612         qword_printint(f, servers->h_num);
 613         if (servers->h_num >= 0) {
 614                 int i;
 615                 for (i=0; i<servers->h_num; i++) {
 616                         qword_print(f, servers->h_mp[i]->h_host);
 617                         qword_print(f, servers->h_mp[i]->h_path);
 618                 }
 619         }
 620         qword_printint(f, servers->h_referral);
 621         release_replicas(servers);
 622 }
 623
 624 static void write_secinfo(FILE *f, struct exportent *ep, int flag_mask)
 625 {
 626         struct sec_entry *p;
 627
 628         for (p = ep->e_secinfo; p->flav; p++)
 629                 ; /* Do nothing */
 630         if (p == ep->e_secinfo) {
 631                 /* There was no sec= option */
 632                 return;
 633         }
 634         qword_print(f, "secinfo");
 635         qword_printint(f, p - ep->e_secinfo);
 636         for (p = ep->e_secinfo; p->flav; p++) {
 637                 qword_printint(f, p->flav->fnum);
 638                 qword_printint(f, p->flags & flag_mask);
 639         }
 640
 641 }
 642
 643 static int dump_to_cache(FILE *f, char *domain, char *path, struct exportent *exp)
 644 {
 645         qword_print(f, domain);
 646         qword_print(f, path);
 647         qword_printint(f, time(0)+30*60);
 648         if (exp) {
 649                 int different_fs = strcmp(path, exp->e_path) != 0;
 650                 int flag_mask = different_fs ? ~NFSEXP_FSID : ~0;
 651
 652                 qword_printint(f, exp->e_flags & flag_mask);
 653                 qword_printint(f, exp->e_anonuid);
 654                 qword_printint(f, exp->e_anongid);
 655                 qword_printint(f, exp->e_fsid);
 656                 write_fsloc(f, exp);
 657                 write_secinfo(f, exp, flag_mask);
 658                 if (exp->e_uuid == NULL || different_fs) {
 659                         char u[16];
 660                         if (uuid_by_path(path, 0, 16, u)) {
 661                                 qword_print(f, "uuid");
 662                                 qword_printhex(f, u, 16);
 663                         }
 664                 } else {
 665                         char u[16];
 666                         get_uuid(exp->e_uuid, 16, u);
 667                         qword_print(f, "uuid");
 668                         qword_printhex(f, u, 16);
 669                 }
 670         }
 671         return qword_eol(f);
 672 }
 673
 674 static int is_subdirectory(char *child, char *parent)
 675 {
 676         int l = strlen(parent);
 677
 678         return strcmp(child, parent) == 0
 679                 || (strncmp(child, parent, l) == 0 && child[l] == '/');
 680 }
 681
 682 static int path_matches(nfs_export *exp, char *path)
 683 {
 684         if (exp->m_export.e_flags & NFSEXP_CROSSMOUNT)
 685                 return is_subdirectory(path, exp->m_export.e_path);
 686         return strcmp(path, exp->m_export.e_path) == 0;
 687 }
 688
 689 static int
 690 client_matches(nfs_export *exp, char *dom, struct addrinfo *ai)
 691 {
 692         if (use_ipaddr)
 693                 return client_check(exp->m_client, ai);
 694         return client_member(dom, exp->m_client->m_hostname);
 695 }
 696
 697 static int
 698 export_matches(nfs_export *exp, char *dom, char *path, struct addrinfo *ai)
 699 {
 700         return path_matches(exp, path) && client_matches(exp, dom, ai);
 701 }
 702
 703 static nfs_export *
 704 lookup_export(char *dom, char *path, struct addrinfo *ai)
 705 {
 706         nfs_export *exp;
 707         nfs_export *found = NULL;
 708         int found_type = 0;
 709         int i;
 710
 711         for (i=0 ; i < MCL_MAXTYPES; i++) {
 712                 for (exp = exportlist[i].p_head; exp; exp = exp->m_next) {
 713                         if (!export_matches(exp, dom, path, ai))
 714                                 continue;
 715                         if (!found) {
 716                                 found = exp;
 717                                 found_type = i;
 718                                 continue;
 719                         }
 720
 721                         /* Always prefer non-V4ROOT mounts */
 722                         if (found->m_export.e_flags & NFSEXP_V4ROOT)
 723                                 continue;
 724
 725                         /* If one is a CROSSMOUNT, then prefer the longest path */
 726                         if (((found->m_export.e_flags & NFSEXP_CROSSMOUNT) ||
 727                              (exp->m_export.e_flags & NFSEXP_CROSSMOUNT)) &&
 728                             strlen(found->m_export.e_path) !=
 729                             strlen(exp->m_export.e_path)) {
 730
 731                                 if (strlen(exp->m_export.e_path) >
 732                                     strlen(found->m_export.e_path)) {
 733                                         found = exp;
 734                                         found_type = i;
 735                                 }
 736                                 continue;
 737
 738                         } else if (found_type == i && found->m_warned == 0) {
 739                                 xlog(L_WARNING, "%s exported to both %s and %s, "
 740                                      "arbitrarily choosing options from first",
 741                                      path, found->m_client->m_hostname, exp->m_client->m_hostname,
 742                                      dom);
 743                                 found->m_warned = 1;
 744                         }
 745                 }
 746         }
 747         return found;
 748 }
 749
 750 static void nfsd_export(FILE *f)
 751 {
 752         /* requests are:
 753          *  domain path
 754          * determine export options and return:
 755          *  domain path expiry flags anonuid anongid fsid
 756          */
 757
 758         char *cp;
 759         char *dom, *path;
 760         nfs_export *found = NULL;
 761         struct addrinfo *ai = NULL;
 762
 763         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
 764                 return;
 765
 766         xlog(D_CALL, "nfsd_export: inbuf '%s'", lbuf);
 767
 768         cp = lbuf;
 769         dom = malloc(strlen(cp));
 770         path = malloc(strlen(cp));
 771
 772         if (!dom || !path)
 773                 goto out;
 774
 775         if (qword_get(&cp, dom, strlen(lbuf)) <= 0)
 776                 goto out;
 777         if (qword_get(&cp, path, strlen(lbuf)) <= 0)
 778                 goto out;
 779
 780         auth_reload();
 781
 782         if (use_ipaddr) {
 783                 struct addrinfo *tmp;
 784                 tmp = host_pton(dom);
 785                 if (tmp == NULL)
 786                         goto out;
 787                 ai = client_resolve(tmp->ai_addr);
 788                 freeaddrinfo(tmp);
 789                         goto out;
 790         }
 791
 792         found = lookup_export(dom, path, ai);
 793
 794         if (found) {
 795                 if (dump_to_cache(f, dom, path, &found->m_export) < 0) {
 796                         xlog(L_WARNING,
 797                              "Cannot export %s, possibly unsupported filesystem"
 798                              " or fsid= required", path);
 799                         dump_to_cache(f, dom, path, NULL);
 800                 }
 801         } else {
 802                 dump_to_cache(f, dom, path, NULL);
 803         }
 804  out:
 805         xlog(D_CALL, "nfsd_export: found %p path %s", found, path ? path : NULL);
 806         if (dom) free(dom);
 807         if (path) free(path);
 808         freeaddrinfo(ai);
 809 }
 810
 811
 812 struct {
 813         char *cache_name;
 814         void (*cache_handle)(FILE *f);
 815         FILE *f;
 816 } cachelist[] = {
 817         { "auth.unix.ip", auth_unix_ip, NULL},
 818         { "auth.unix.gid", auth_unix_gid, NULL},
 819         { "nfsd.export", nfsd_export, NULL},
 820         { "nfsd.fh", nfsd_fh, NULL},
 821         { NULL, NULL, NULL }
 822 };
 823
 824 extern int manage_gids;
 825
 826 /**
 827  * cache_open - prepare communications channels with kernel RPC caches
 828  *
 829  */
 830 void cache_open(void)
 831 {
 832         int i;
 833         for (i=0; cachelist[i].cache_name; i++ ) {
 834                 char path[100];
 835                 if (!manage_gids && cachelist[i].cache_handle == auth_unix_gid)
 836                         continue;
 837                 sprintf(path, "/proc/net/rpc/%s/channel", cachelist[i].cache_name);
 838                 cachelist[i].f = fopen(path, "r+");
 839         }
 840 }
 841
 842 /**
 843  * cache_set_fds - prepare cache file descriptors for one iteration of the service loop
 844  * @fdset: pointer to fd_set to prepare
 845  */
 846 void cache_set_fds(fd_set *fdset)
 847 {
 848         int i;
 849         for (i=0; cachelist[i].cache_name; i++) {
 850                 if (cachelist[i].f)
 851                         FD_SET(fileno(cachelist[i].f), fdset);
 852         }
 853 }
 854
 855 /**
 856  * cache_process_req - process any active cache file descriptors during service loop iteration
 857  * @fdset: pointer to fd_set to examine for activity
 858  */
 859 int cache_process_req(fd_set *readfds)
 860 {
 861         int i;
 862         int cnt = 0;
 863         for (i=0; cachelist[i].cache_name; i++) {
 864                 if (cachelist[i].f != NULL &&
 865                     FD_ISSET(fileno(cachelist[i].f), readfds)) {
 866                         cnt++;
 867                         cachelist[i].cache_handle(cachelist[i].f);
 868                         FD_CLR(fileno(cachelist[i].f), readfds);
 869                 }
 870         }
 871         return cnt;
 872 }
 873
 874
 875 /*
 876  * Give IP->domain and domain+path->options to kernel
 877  * % echo nfsd $IP  $[now+30*60] $domain > /proc/net/rpc/auth.unix.ip/channel
 878  * % echo $domain $path $[now+30*60] $options $anonuid $anongid $fsid > /proc/net/rpc/nfsd.export/channel
 879  */
 880
 881 static int cache_export_ent(char *domain, struct exportent *exp, char *path)
 882 {
 883         int err;
 884         FILE *f = fopen("/proc/net/rpc/nfsd.export/channel", "w");
 885         if (!f)
 886                 return -1;
 887
 888         err = dump_to_cache(f, domain, exp->e_path, exp);
 889         if (err) {
 890                 xlog(L_WARNING,
 891                      "Cannot export %s, possibly unsupported filesystem or"
 892                      " fsid= required", exp->e_path);
 893         }
 894
 895         while (err == 0 && (exp->e_flags & NFSEXP_CROSSMOUNT) && path) {
 896                 /* really an 'if', but we can break out of
 897                  * a 'while' more easily */
 898                 /* Look along 'path' for other filesystems
 899                  * and export them with the same options
 900                  */
 901                 struct stat stb;
 902                 size_t l = strlen(exp->e_path);
 903                 __dev_t dev;
 904
 905                 if (strlen(path) <= l || path[l] != '/' ||
 906                     strncmp(exp->e_path, path, l) != 0)
 907                         break;
 908                 if (stat(exp->e_path, &stb) != 0)
 909                         break;
 910                 dev = stb.st_dev;
 911                 while(path[l] == '/') {
 912                         char c;
 913                         /* errors for submount should fail whole filesystem */
 914                         int err2;
 915
 916                         l++;
 917                         while (path[l] != '/' && path[l])
 918                                 l++;
 919                         c = path[l];
 920                         path[l] = 0;
 921                         err2 = lstat(path, &stb);
 922                         path[l] = c;
 923                         if (err2 < 0)
 924                                 break;
 925                         if (stb.st_dev == dev)
 926                                 continue;
 927                         dev = stb.st_dev;
 928                         path[l] = 0;
 929                         dump_to_cache(f, domain, path, exp);
 930                         path[l] = c;
 931                 }
 932                 break;
 933         }
 934
 935         fclose(f);
 936         return err;
 937 }
 938
 939 /**
 940  * cache_export - Inform kernel of a new nfs_export
 941  * @exp: target nfs_export
 942  * @path: NUL-terminated C string containing export path
 943  */
 944 int cache_export(nfs_export *exp, char *path)
 945 {
 946         char buf[INET6_ADDRSTRLEN];
 947         int err;
 948         FILE *f;
 949
 950         f = fopen("/proc/net/rpc/auth.unix.ip/channel", "w");
 951         if (!f)
 952                 return -1;
 953
 954
 955         qword_print(f, "nfsd");
 956         qword_print(f,
 957                 host_ntop(get_addrlist(exp->m_client, 0), buf, sizeof(buf)));
 958         qword_printint(f, time(0)+30*60);
 959         qword_print(f, exp->m_client->m_hostname);
 960         err = qword_eol(f);
 961
 962         fclose(f);
 963
 964         err = cache_export_ent(exp->m_client->m_hostname, &exp->m_export, path)
 965                 || err;
 966         return err;
 967 }
 968
 969 /**
 970  * cache_get_filehandle - given an nfs_export, get its root filehandle
 971  * @exp: target nfs_export
 972  * @len: length of requested file handle
 973  * @p: NUL-terminated C string containing export path
 974  *
 975  * Returns pointer to NFS file handle of root directory of export
 976  *
 977  * {
 978  *   echo $domain $path $length
 979  *   read filehandle <&0
 980  * } <> /proc/fs/nfsd/filehandle
 981  */
 982 struct nfs_fh_len *
 983 cache_get_filehandle(nfs_export *exp, int len, char *p)
 984 {
 985         FILE *f = fopen("/proc/fs/nfsd/filehandle", "r+");
 986         char buf[200];
 987         char *bp = buf;
 988         int failed;
 989         static struct nfs_fh_len fh;
 990
 991         if (!f)
 992                 f = fopen("/proc/fs/nfs/filehandle", "r+");
 993         if (!f)
 994                 return NULL;
 995
 996         qword_print(f, exp->m_client->m_hostname);
 997         qword_print(f, p);
 998         qword_printint(f, len);
 999         failed = qword_eol(f);
1000
1001         if (!failed)
1002                 failed = (fgets(buf, sizeof(buf), f) == NULL);
1003         fclose(f);
1004         if (failed)
1005                 return NULL;
1006         memset(fh.fh_handle, 0, sizeof(fh.fh_handle));
1007         fh.fh_size = qword_get(&bp, (char *)fh.fh_handle, NFS3_FHSIZE);
1008         return &fh;
1009 }