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