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 <time.h>
  18 #include <netinet/in.h>
  19 #include <arpa/inet.h>
  20 #include <unistd.h>
  21 #include <fcntl.h>
  22 #include <errno.h>
  23 #include <ctype.h>
  24 #include <pwd.h>
  25 #include <grp.h>
  26 #include "misc.h"
  27 #include "nfslib.h"
  28 #include "exportfs.h"
  29 #include "mountd.h"
  30 #include "xmalloc.h"
  31
  32 #include "blkid/blkid.h"
  33
  34
  35 enum nfsd_fsid {
  36         FSID_DEV = 0,
  37         FSID_NUM,
  38         FSID_MAJOR_MINOR,
  39         FSID_ENCODE_DEV,
  40         FSID_UUID4_INUM,
  41         FSID_UUID8,
  42         FSID_UUID16,
  43         FSID_UUID16_INUM,
  44 };
  45
  46 /*
  47  * Support routines for text-based upcalls.
  48  * Fields are separated by spaces.
  49  * Fields are either mangled to quote space tab newline slosh with slosh
  50  * or a hexified with a leading \x
  51  * Record is terminated with newline.
  52  *
  53  */
  54 int cache_export_ent(char *domain, struct exportent *exp);
  55
  56
  57 char *lbuf  = NULL;
  58 int lbuflen = 0;
  59
  60 void auth_unix_ip(FILE *f)
  61 {
  62         /* requests are
  63          *  class IP-ADDR
  64          * Ignore if class != "nfsd"
  65          * Otherwise find domainname and write back:
  66          *
  67          *  "nfsd" IP-ADDR expiry domainname
  68          */
  69         char *cp;
  70         char class[20];
  71         char ipaddr[20];
  72         char *client;
  73         struct in_addr addr;
  74         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
  75                 return;
  76
  77         cp = lbuf;
  78
  79         if (qword_get(&cp, class, 20) <= 0 ||
  80             strcmp(class, "nfsd") != 0)
  81                 return;
  82
  83         if (qword_get(&cp, ipaddr, 20) <= 0)
  84                 return;
  85
  86         if (inet_aton(ipaddr, &addr)==0)
  87                 return;
  88
  89         auth_reload();
  90
  91         /* addr is a valid, interesting address, find the domain name... */
  92         client = client_compose(addr);
  93
  94
  95         qword_print(f, "nfsd");
  96         qword_print(f, ipaddr);
  97         qword_printint(f, time(0)+30*60);
  98         if (client)
  99                 qword_print(f, *client?client:"DEFAULT");
 100         qword_eol(f);
 101
 102         if (client) free(client);
 103
 104 }
 105
 106 void auth_unix_gid(FILE *f)
 107 {
 108         /* Request are
 109          *  uid
 110          * reply is
 111          *  uid expiry count list of group ids
 112          */
 113         int uid;
 114         struct passwd *pw;
 115         gid_t glist[100], *groups = glist;
 116         int ngroups = 100;
 117         int rv, i;
 118         char *cp;
 119
 120         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
 121                 return;
 122
 123         cp = lbuf;
 124         if (qword_get_int(&cp, &uid) != 0)
 125                 return;
 126
 127         pw = getpwuid(uid);
 128         if (!pw)
 129                 rv = -1;
 130         else {
 131                 rv = getgrouplist(pw->pw_name, pw->pw_gid, groups, &ngroups);
 132                 if (rv == -1 && ngroups >= 100) {
 133                         groups = malloc(sizeof(gid_t)*ngroups);
 134                         if (!groups)
 135                                 rv = -1;
 136                         else
 137                                 rv = getgrouplist(pw->pw_name, pw->pw_gid,
 138                                                   groups, &ngroups);
 139                 }
 140         }
 141         qword_printint(f, uid);
 142         qword_printint(f, time(0)+30*60);
 143         if (rv >= 0) {
 144                 qword_printint(f, ngroups);
 145                 for (i=0; i<ngroups; i++)
 146                         qword_printint(f, groups[i]);
 147         }
 148         qword_eol(f);
 149         if (groups != glist)
 150                 free(groups);
 151 }
 152
 153 int get_uuid(char *path, char *uuid, int uuidlen, char *u)
 154 {
 155         /* extract hex digits from uuidstr and compose a uuid
 156          * of the given length (max 16), xoring bytes to make
 157          * a smaller uuid.  Then compare with uuid
 158          */
 159         int i = 0;
 160         const char *val;
 161
 162         if (path) {
 163                 static blkid_cache cache = NULL;
 164                 struct stat stb;
 165                 char *devname;
 166                 blkid_tag_iterate iter;
 167                 blkid_dev dev;
 168                 const char *type;
 169                 if (cache == NULL)
 170                         blkid_get_cache(&cache, NULL);
 171
 172                 blkid_probe_all_new(cache);
 173
 174                 if (stat(path, &stb) != 0)
 175                         return 0;
 176                 devname = blkid_devno_to_devname(stb.st_dev);
 177                 if (!devname)
 178                         return 0;
 179                 dev = blkid_get_dev(cache, devname, BLKID_DEV_NORMAL);
 180                 free(devname);
 181                 if (!dev)
 182                         return 0;
 183                 iter = blkid_tag_iterate_begin(dev);
 184                 if (!iter)
 185                         return 0;
 186                 while (blkid_tag_next(iter, &type, &val) == 0)
 187                         if (strcmp(type, "UUID") == 0)
 188                                 break;
 189                 blkid_tag_iterate_end(iter);
 190                 if (!type)
 191                         return 0;
 192         } else {
 193                 val = uuid;
 194         }
 195
 196         memset(u, 0, uuidlen);
 197         for ( ; *val ; val++) {
 198                 char c = *val;
 199                 if (!isxdigit(c))
 200                         continue;
 201                 if (isalpha(c)) {
 202                         if (isupper(c))
 203                                 c = c - 'A' + 10;
 204                         else
 205                                 c = c - 'a' + 10;
 206                 } else
 207                         c = c - '0' + 0;
 208                 if ((i&1) == 0)
 209                         c <<= 4;
 210                 u[i/2] ^= c;
 211                 i++;
 212                 if (i == uuidlen*2)
 213                         i = 0;
 214         }
 215         return 1;
 216 }
 217
 218
 219 void nfsd_fh(FILE *f)
 220 {
 221         /* request are:
 222          *  domain fsidtype fsid
 223          * interpret fsid, find export point and options, and write:
 224          *  domain fsidtype fsid expiry path
 225          */
 226         char *cp;
 227         char *dom;
 228         int fsidtype;
 229         int fsidlen;
 230         unsigned int dev, major=0, minor=0;
 231         unsigned int inode=0;
 232         unsigned long long inode64;
 233         unsigned int fsidnum=0;
 234         char fsid[32];
 235         struct exportent *found = NULL;
 236         nfs_export *exp;
 237         int i;
 238         int dev_missing = 0;
 239         int uuidlen = 0;
 240         char *fhuuid = NULL;
 241
 242         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
 243                 return;
 244
 245         cp = lbuf;
 246
 247         dom = malloc(strlen(cp));
 248         if (dom == NULL)
 249                 return;
 250         if (qword_get(&cp, dom, strlen(cp)) <= 0)
 251                 goto out;
 252         if (qword_get_int(&cp, &fsidtype) != 0)
 253                 goto out;
 254         if (fsidtype < 0 || fsidtype > 7)
 255                 goto out; /* unknown type */
 256         if ((fsidlen = qword_get(&cp, fsid, 32)) <= 0)
 257                 goto out;
 258         switch(fsidtype) {
 259         case FSID_DEV: /* 4 bytes: 2 major, 2 minor, 4 inode */
 260                 if (fsidlen != 8)
 261                         goto out;
 262                 memcpy(&dev, fsid, 4);
 263                 memcpy(&inode, fsid+4, 4);
 264                 major = ntohl(dev)>>16;
 265                 minor = ntohl(dev) & 0xFFFF;
 266                 break;
 267
 268         case FSID_NUM: /* 4 bytes - fsid */
 269                 if (fsidlen != 4)
 270                         goto out;
 271                 memcpy(&fsidnum, fsid, 4);
 272                 break;
 273
 274         case FSID_MAJOR_MINOR: /* 12 bytes: 4 major, 4 minor, 4 inode
 275                  * This format is never actually used but was
 276                  * an historical accident
 277                  */
 278                 if (fsidlen != 12)
 279                         goto out;
 280                 memcpy(&dev, fsid, 4); major = ntohl(dev);
 281                 memcpy(&dev, fsid+4, 4); minor = ntohl(dev);
 282                 memcpy(&inode, fsid+8, 4);
 283                 break;
 284
 285         case FSID_ENCODE_DEV: /* 8 bytes: 4 byte packed device number, 4 inode */
 286                 /* This is *host* endian, not net-byte-order, because
 287                  * no-one outside this host has any business interpreting it
 288                  */
 289                 if (fsidlen != 8)
 290                         goto out;
 291                 memcpy(&dev, fsid, 4);
 292                 memcpy(&inode, fsid+4, 4);
 293                 major = (dev & 0xfff00) >> 8;
 294                 minor = (dev & 0xff) | ((dev >> 12) & 0xfff00);
 295                 break;
 296
 297         case FSID_UUID4_INUM: /* 4 byte inode number and 4 byte uuid */
 298                 if (fsidlen != 8)
 299                         goto out;
 300                 memcpy(&inode, fsid, 4);
 301                 uuidlen = 4;
 302                 fhuuid = fsid+4;
 303                 break;
 304         case FSID_UUID8: /* 8 byte uuid */
 305                 if (fsidlen != 8)
 306                         goto out;
 307                 uuidlen = 8;
 308                 fhuuid = fsid;
 309                 break;
 310         case FSID_UUID16: /* 16 byte uuid */
 311                 if (fsidlen != 16)
 312                         goto out;
 313                 uuidlen = 16;
 314                 fhuuid = fsid;
 315                 break;
 316         case FSID_UUID16_INUM: /* 8 byte inode number and 16 byte uuid */
 317                 if (fsidlen != 24)
 318                         goto out;
 319                 memcpy(&inode64, fsid, 8);
 320                 inode = inode64;
 321                 uuidlen = 16;
 322                 fhuuid = fsid+8;
 323                 break;
 324         }
 325
 326         auth_reload();
 327
 328         /* Now determine export point for this fsid/domain */
 329         for (i=0 ; i < MCL_MAXTYPES; i++) {
 330                 for (exp = exportlist[i]; exp; exp = exp->m_next) {
 331                         struct stat stb;
 332                         char u[16];
 333
 334                         if (!client_member(dom, exp->m_client->m_hostname))
 335                                 continue;
 336                         if (exp->m_export.e_mountpoint &&
 337                             !is_mountpoint(exp->m_export.e_mountpoint[0]?
 338                                            exp->m_export.e_mountpoint:
 339                                            exp->m_export.e_path))
 340                                 dev_missing ++;
 341                         if (stat(exp->m_export.e_path, &stb) != 0)
 342                                 continue;
 343                         switch(fsidtype){
 344                         case FSID_DEV:
 345                         case FSID_MAJOR_MINOR:
 346                         case FSID_ENCODE_DEV:
 347                                 if (stb.st_ino != inode)
 348                                         continue;
 349                                 if (major != major(stb.st_dev) ||
 350                                     minor != minor(stb.st_dev))
 351                                         continue;
 352                                 break;
 353                         case FSID_NUM:
 354                                 if (((exp->m_export.e_flags & NFSEXP_FSID) == 0 ||
 355                                      exp->m_export.e_fsid != fsidnum))
 356                                         continue;
 357                                 break;
 358                         case FSID_UUID4_INUM:
 359                         case FSID_UUID16_INUM:
 360                                 if (stb.st_ino != inode)
 361                                         continue;
 362                                 goto check_uuid;
 363                         case FSID_UUID8:
 364                         case FSID_UUID16:
 365                                 if (!is_mountpoint(exp->m_export.e_path))
 366                                         continue;
 367                         check_uuid:
 368                                 if (exp->m_export.e_uuid)
 369                                         get_uuid(NULL, exp->m_export.e_uuid,
 370                                                  uuidlen, u);
 371                                 else if (get_uuid(exp->m_export.e_path, NULL,
 372                                                   uuidlen, u) == 0)
 373                                         continue;
 374
 375                                 if (memcmp(u, fhuuid, uuidlen) != 0)
 376                                         continue;
 377                                 break;
 378                         }
 379                         /* It's a match !! */
 380                         if (!found)
 381                                 found = &exp->m_export;
 382                         else if (strcmp(found->e_path, exp->m_export.e_path)!= 0)
 383                         {
 384                                 xlog(L_WARNING, "%s and %s have same filehandle for %s, using first",
 385                                      found->e_path, exp->m_export.e_path, dom);
 386                         }
 387                 }
 388         }
 389         if (found &&
 390             found->e_mountpoint &&
 391             !is_mountpoint(found->e_mountpoint[0]?
 392                            found->e_mountpoint:
 393                            found->e_path)) {
 394                 /* Cannot export this yet
 395                  * should log a warning, but need to rate limit
 396                    xlog(L_WARNING, "%s not exported as %d not a mountpoint",
 397                    found->e_path, found->e_mountpoint);
 398                  */
 399                 /* FIXME we need to make sure we re-visit this later */
 400                 goto out;
 401         }
 402         if (!found && dev_missing) {
 403                 /* The missing dev could be what we want, so just be
 404                  * quite rather than returning stale yet
 405                  */
 406                 goto out;
 407         }
 408
 409         if (found)
 410                 cache_export_ent(dom, found);
 411
 412         qword_print(f, dom);
 413         qword_printint(f, fsidtype);
 414         qword_printhex(f, fsid, fsidlen);
 415         qword_printint(f, time(0)+30*60);
 416         if (found)
 417                 qword_print(f, found->e_path);
 418         qword_eol(f);
 419  out:
 420         free(dom);
 421         return;
 422 }
 423
 424 static int dump_to_cache(FILE *f, char *domain, char *path, struct exportent *exp)
 425 {
 426         qword_print(f, domain);
 427         qword_print(f, path);
 428         qword_printint(f, time(0)+30*60);
 429         if (exp) {
 430                 qword_printint(f, exp->e_flags);
 431                 qword_printint(f, exp->e_anonuid);
 432                 qword_printint(f, exp->e_anongid);
 433                 qword_printint(f, exp->e_fsid);
 434                 if (exp->e_uuid == NULL) {
 435                         char u[16];
 436                         if (get_uuid(exp->e_path, NULL, 16, u)) {
 437                                 qword_print(f, "uuid");
 438                                 qword_printhex(f, u, 16);
 439                         }
 440                 } else if (exp->e_uuid) {
 441                         qword_print(f, "uuid");
 442                         qword_printhex(f, exp->e_uuid, 16);
 443                 }
 444         }
 445         return qword_eol(f);
 446 }
 447
 448 void nfsd_export(FILE *f)
 449 {
 450         /* requests are:
 451          *  domain path
 452          * determine export options and return:
 453          *  domain path expiry flags anonuid anongid fsid
 454          */
 455
 456         char *cp;
 457         int i;
 458         char *dom, *path;
 459         nfs_export *exp, *found = NULL;
 460
 461
 462         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
 463                 return;
 464
 465         cp = lbuf;
 466         dom = malloc(strlen(cp));
 467         path = malloc(strlen(cp));
 468
 469         if (!dom || !path)
 470                 goto out;
 471
 472         if (qword_get(&cp, dom, strlen(lbuf)) <= 0)
 473                 goto out;
 474         if (qword_get(&cp, path, strlen(lbuf)) <= 0)
 475                 goto out;
 476
 477         auth_reload();
 478
 479         /* now find flags for this export point in this domain */
 480         for (i=0 ; i < MCL_MAXTYPES; i++) {
 481                 for (exp = exportlist[i]; exp; exp = exp->m_next) {
 482                         if (!client_member(dom, exp->m_client->m_hostname))
 483                                 continue;
 484                         if (strcmp(path, exp->m_export.e_path))
 485                                 continue;
 486                         if (!found)
 487                                 found = exp;
 488                         else {
 489                                 xlog(L_WARNING, "%s exported to both %s and %s in %s",
 490                                      path, exp->m_client->m_hostname, found->m_client->m_hostname,
 491                                      dom);
 492                         }
 493                 }
 494         }
 495
 496         if (found) {
 497                 dump_to_cache(f, dom, path, &found->m_export);
 498                 mountlist_add(dom, path);
 499         } else {
 500                 dump_to_cache(f, dom, path, NULL);
 501         }
 502  out:
 503         if (dom) free(dom);
 504         if (path) free(path);
 505 }
 506
 507
 508 struct {
 509         char *cache_name;
 510         void (*cache_handle)(FILE *f);
 511         FILE *f;
 512 } cachelist[] = {
 513         { "auth.unix.ip", auth_unix_ip},
 514         { "auth.unix.gid", auth_unix_gid},
 515         { "nfsd.export", nfsd_export},
 516         { "nfsd.fh", nfsd_fh},
 517         { NULL, NULL }
 518 };
 519
 520 extern int manage_gids;
 521 void cache_open(void)
 522 {
 523         int i;
 524         for (i=0; cachelist[i].cache_name; i++ ) {
 525                 char path[100];
 526                 if (!manage_gids && cachelist[i].f == auth_unix_gid)
 527                         continue;
 528                 sprintf(path, "/proc/net/rpc/%s/channel", cachelist[i].cache_name);
 529                 cachelist[i].f = fopen(path, "r+");
 530         }
 531 }
 532
 533 void cache_set_fds(fd_set *fdset)
 534 {
 535         int i;
 536         for (i=0; cachelist[i].cache_name; i++) {
 537                 if (cachelist[i].f)
 538                         FD_SET(fileno(cachelist[i].f), fdset);
 539         }
 540 }
 541
 542 int cache_process_req(fd_set *readfds)
 543 {
 544         int i;
 545         int cnt = 0;
 546         for (i=0; cachelist[i].cache_name; i++) {
 547                 if (cachelist[i].f != NULL &&
 548                     FD_ISSET(fileno(cachelist[i].f), readfds)) {
 549                         cnt++;
 550                         cachelist[i].cache_handle(cachelist[i].f);
 551                         FD_CLR(fileno(cachelist[i].f), readfds);
 552                 }
 553         }
 554         return cnt;
 555 }
 556
 557
 558 /*
 559  * Give IP->domain and domain+path->options to kernel
 560  * % echo nfsd $IP  $[now+30*60] $domain > /proc/net/rpc/auth.unix.ip/channel
 561  * % echo $domain $path $[now+30*60] $options $anonuid $anongid $fsid > /proc/net/rpc/nfsd.export/channel
 562  */
 563
 564 int cache_export_ent(char *domain, struct exportent *exp)
 565 {
 566         int err;
 567         FILE *f = fopen("/proc/net/rpc/nfsd.export/channel", "w");
 568         if (!f)
 569                 return -1;
 570
 571         err = dump_to_cache(f, domain, exp->e_path, exp);
 572         fclose(f);
 573         mountlist_add(domain, exp->e_path);
 574         return err;
 575 }
 576
 577 int cache_export(nfs_export *exp)
 578 {
 579         int err;
 580         FILE *f;
 581
 582         if (exp->m_export.e_maptype != CLE_MAP_IDENT) {
 583                 xlog(L_ERROR, "%s: unsupported mapping; kernel supports only 'identity' (default)",
 584                     exp->m_export.m_path);
 585                 return -1;
 586         }
 587
 588         f = fopen("/proc/net/rpc/auth.unix.ip/channel", "w");
 589         if (!f)
 590                 return -1;
 591
 592         qword_print(f, "nfsd");
 593         qword_print(f, inet_ntoa(exp->m_client->m_addrlist[0]));
 594         qword_printint(f, time(0)+30*60);
 595         qword_print(f, exp->m_client->m_hostname);
 596         err = qword_eol(f);
 597
 598         fclose(f);
 599
 600         err = cache_export_ent(exp->m_client->m_hostname, &exp->m_export)
 601                 || err;
 602         return err;
 603 }
 604
 605 /* Get a filehandle.
 606  * {
 607  *   echo $domain $path $length
 608  *   read filehandle <&0
 609  * } <> /proc/fs/nfsd/filehandle
 610  */
 611 struct nfs_fh_len *
 612 cache_get_filehandle(nfs_export *exp, int len, char *p)
 613 {
 614         FILE *f = fopen("/proc/fs/nfsd/filehandle", "r+");
 615         char buf[200];
 616         char *bp = buf;
 617         int failed;
 618         static struct nfs_fh_len fh;
 619
 620         if (!f)
 621                 f = fopen("/proc/fs/nfs/filehandle", "r+");
 622         if (!f)
 623                 return NULL;
 624
 625         qword_print(f, exp->m_client->m_hostname);
 626         qword_print(f, p);
 627         qword_printint(f, len);
 628         failed = qword_eol(f);
 629
 630         if (!failed)
 631                 failed = (fgets(buf, sizeof(buf), f) == NULL);
 632         fclose(f);
 633         if (failed)
 634                 return NULL;
 635         memset(fh.fh_handle, 0, sizeof(fh.fh_handle));
 636         fh.fh_size = qword_get(&bp, (char *)fh.fh_handle, NFS3_FHSIZE);
 637         return &fh;
 638 }
 639