nis/nis_call.c

   1 /* Copyright (C) 1997-2022 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include <fcntl.h>
  20 #include <string.h>
  21 #include <libintl.h>
  22 #include <rpc/rpc.h>
  23 #include <rpc/auth.h>
  24 #include <rpcsvc/nis.h>
  25 #include <sys/socket.h>
  26 #include <sys/stat.h>
  27 #include <unistd.h>
  28 #include <netinet/in.h>
  29 #include <arpa/inet.h>
  30 #include <libc-lock.h>
  31
  32 #include "nis_xdr.h"
  33 #include "nis_intern.h"
  34 #include <libnsl.h>
  35 #include <shlib-compat.h>
  36
  37 static const struct timeval RPCTIMEOUT = {10, 0};
  38 static const struct timeval UDPTIMEOUT = {5, 0};
  39
  40 extern u_short __pmap_getnisport (struct sockaddr_in *address, u_long program,
  41                                   u_long version, u_int protocol);
  42
  43 unsigned long int
  44 inetstr2int (const char *str)
  45 {
  46   size_t j = 0;
  47   for (size_t i = 0; str[i] != '\0'; ++i)
  48     if (str[i] == '.' && __builtin_expect (++j == 4, 0))
  49       {
  50         char buffer[i + 1];
  51         buffer[i] = '\0';
  52         return inet_addr (memcpy (buffer, str, i));
  53       }
  54
  55   return inet_addr (str);
  56 }
  57
  58 void
  59 __nisbind_destroy (dir_binding *bind)
  60 {
  61   if (bind->clnt != NULL)
  62     {
  63       if (bind->use_auth)
  64         auth_destroy (bind->clnt->cl_auth);
  65       clnt_destroy (bind->clnt);
  66     }
  67 }
  68 libnsl_hidden_nolink_def (__nisbind_destroy, GLIBC_2_1)
  69
  70 nis_error
  71 __nisbind_next (dir_binding *bind)
  72 {
  73   if (bind->clnt != NULL)
  74     {
  75       if (bind->use_auth)
  76         auth_destroy (bind->clnt->cl_auth);
  77       clnt_destroy (bind->clnt);
  78       bind->clnt = NULL;
  79     }
  80
  81   if (bind->trys >= bind->server_len)
  82     return NIS_FAIL;
  83
  84   for (u_int j = bind->current_ep + 1;
  85        j < bind->server_val[bind->server_used].ep.ep_len; ++j)
  86     if (strcmp (bind->server_val[bind->server_used].ep.ep_val[j].family,
  87                 "inet") == 0)
  88       if (bind->server_val[bind->server_used].ep.ep_val[j].proto[0] == '-')
  89         {
  90           bind->current_ep = j;
  91           return NIS_SUCCESS;
  92         }
  93
  94   ++bind->trys;
  95   ++bind->server_used;
  96   if (bind->server_used >= bind->server_len)
  97     bind->server_used = 0;
  98
  99   for (u_int j = 0; j < bind->server_val[bind->server_used].ep.ep_len; ++j)
 100     if (strcmp (bind->server_val[bind->server_used].ep.ep_val[j].family,
 101                 "inet") == 0)
 102       if (bind->server_val[bind->server_used].ep.ep_val[j].proto[0] == '-')
 103         {
 104           bind->current_ep = j;
 105           return NIS_SUCCESS;
 106         }
 107
 108   return NIS_FAIL;
 109 }
 110 libnsl_hidden_nolink_def (__nisbind_next, GLIBC_2_1)
 111
 112 static struct ckey_cache_entry
 113 {
 114   struct in_addr inaddr;
 115   in_port_t port;
 116   unsigned int protocol;
 117   des_block ckey;
 118 } *ckey_cache;
 119 static size_t ckey_cache_size;
 120 static size_t ckey_cache_allocated;
 121 static pid_t ckey_cache_pid;
 122 static uid_t ckey_cache_euid;
 123 __libc_lock_define_initialized (static, ckey_cache_lock)
 124
 125 static bool_t
 126 get_ckey (des_block *ckey, struct sockaddr_in *addr, unsigned int protocol)
 127 {
 128   size_t i;
 129   pid_t pid = getpid ();
 130   uid_t euid = geteuid ();
 131   bool_t ret = FALSE;
 132
 133   __libc_lock_lock (ckey_cache_lock);
 134
 135   if (ckey_cache_pid != pid || ckey_cache_euid != euid)
 136     {
 137       ckey_cache_size = 0;
 138       ckey_cache_pid = pid;
 139       ckey_cache_euid = euid;
 140     }
 141
 142   for (i = 0; i < ckey_cache_size; ++i)
 143     if (ckey_cache[i].port == addr->sin_port
 144         && ckey_cache[i].protocol == protocol
 145         && memcmp (&ckey_cache[i].inaddr, &addr->sin_addr,
 146                    sizeof (addr->sin_addr)) == 0)
 147       {
 148         *ckey = ckey_cache[i].ckey;
 149         ret = TRUE;
 150         break;
 151       }
 152
 153   if (!ret && key_gendes (ckey) >= 0)
 154     {
 155       ret = TRUE;
 156       /* Don't grow the cache indefinitely.  */
 157       if (ckey_cache_size == 256)
 158         ckey_cache_size = 0;
 159       if (ckey_cache_size == ckey_cache_allocated)
 160         {
 161           size_t size = ckey_cache_allocated ? ckey_cache_allocated * 2 : 16;
 162           struct ckey_cache_entry *new_cache
 163             = realloc (ckey_cache, size * sizeof (*ckey_cache));
 164           if (new_cache != NULL)
 165             {
 166               ckey_cache = new_cache;
 167               ckey_cache_allocated = size;
 168             }
 169         }
 170       ckey_cache[ckey_cache_size].inaddr = addr->sin_addr;
 171       ckey_cache[ckey_cache_size].port = addr->sin_port;
 172       ckey_cache[ckey_cache_size].protocol = protocol;
 173       ckey_cache[ckey_cache_size++].ckey = *ckey;
 174     }
 175
 176   __libc_lock_unlock (ckey_cache_lock);
 177   return ret;
 178 }
 179
 180 nis_error
 181 __nisbind_connect (dir_binding *dbp)
 182 {
 183   nis_server *serv;
 184   u_short port;
 185
 186   if (dbp == NULL)
 187     return NIS_FAIL;
 188
 189   serv = &dbp->server_val[dbp->server_used];
 190
 191   memset (&dbp->addr, '\0', sizeof (dbp->addr));
 192   dbp->addr.sin_family = AF_INET;
 193
 194   dbp->addr.sin_addr.s_addr =
 195     inetstr2int (serv->ep.ep_val[dbp->current_ep].uaddr);
 196
 197   if (dbp->addr.sin_addr.s_addr == INADDR_NONE)
 198     return NIS_FAIL;
 199
 200   /* Check, if the host is online and rpc.nisd is running. Much faster
 201      then the clnt*_create functions: */
 202   port = __pmap_getnisport (&dbp->addr, NIS_PROG, NIS_VERSION,
 203                             dbp->use_udp ? IPPROTO_UDP : IPPROTO_TCP);
 204   if (port == 0)
 205     return NIS_RPCERROR;
 206
 207   dbp->addr.sin_port = htons (port);
 208   dbp->socket = RPC_ANYSOCK;
 209   if (dbp->use_udp)
 210     dbp->clnt = clntudp_create (&dbp->addr, NIS_PROG, NIS_VERSION,
 211                                  UDPTIMEOUT, &dbp->socket);
 212   else
 213     dbp->clnt = clnttcp_create (&dbp->addr, NIS_PROG, NIS_VERSION,
 214                                  &dbp->socket, 0, 0);
 215
 216   if (dbp->clnt == NULL)
 217     return NIS_RPCERROR;
 218
 219   clnt_control (dbp->clnt, CLSET_TIMEOUT, (caddr_t) &RPCTIMEOUT);
 220   /* If the program exists, close the socket */
 221   if (fcntl (dbp->socket, F_SETFD, 1) == -1)
 222     perror ("fcntl: F_SETFD");
 223
 224   if (dbp->use_auth)
 225     {
 226       if (serv->key_type == NIS_PK_DH)
 227         {
 228           char netname[MAXNETNAMELEN + 1];
 229           char *p;
 230           des_block ckey;
 231
 232           p = stpcpy (netname, "unix@");
 233           strncpy (p, serv->name, MAXNETNAMELEN - 5);
 234           netname[MAXNETNAMELEN] = '\0';
 235           dbp->clnt->cl_auth = NULL;
 236           if (get_ckey (&ckey, &dbp->addr,
 237                         dbp->use_udp ? IPPROTO_UDP : IPPROTO_TCP))
 238             dbp->clnt->cl_auth =
 239               authdes_pk_create (netname, &serv->pkey, 300, NULL, &ckey);
 240           if (!dbp->clnt->cl_auth)
 241             dbp->clnt->cl_auth = authunix_create_default ();
 242         }
 243       else
 244         dbp->clnt->cl_auth = authunix_create_default ();
 245     }
 246
 247   return NIS_SUCCESS;
 248 }
 249 libnsl_hidden_nolink_def (__nisbind_connect, GLIBC_2_1)
 250
 251 nis_error
 252 __nisbind_create (dir_binding *dbp, const nis_server *serv_val,
 253                   unsigned int serv_len, unsigned int server_used,
 254                   unsigned int current_ep, unsigned int flags)
 255 {
 256   dbp->clnt = NULL;
 257
 258   dbp->server_len = serv_len;
 259   dbp->server_val = (nis_server *)serv_val;
 260
 261   if (flags & USE_DGRAM)
 262     dbp->use_udp = TRUE;
 263   else
 264     dbp->use_udp = FALSE;
 265
 266   if (flags & NO_AUTHINFO)
 267     dbp->use_auth = FALSE;
 268   else
 269     dbp->use_auth = TRUE;
 270
 271   if (flags & MASTER_ONLY)
 272     dbp->master_only = TRUE;
 273   else
 274     dbp->master_only = FALSE;
 275
 276   /* We try the first server */
 277   dbp->trys = 1;
 278
 279   dbp->class = -1;
 280   if (server_used == ~0)
 281     {
 282       if (__nis_findfastest (dbp) < 1)
 283         return NIS_NAMEUNREACHABLE;
 284     }
 285   else
 286     {
 287       dbp->server_used = server_used;
 288       dbp->current_ep = current_ep;
 289     }
 290
 291   return NIS_SUCCESS;
 292 }
 293 libnsl_hidden_nolink_def (__nisbind_create, GLIBC_2_1)
 294
 295 /* __nisbind_connect (dbp) must be run before calling this function !
 296    So we could use the same binding twice */
 297 nis_error
 298 __do_niscall3 (dir_binding *dbp, u_long prog, xdrproc_t xargs, caddr_t req,
 299                xdrproc_t xres, caddr_t resp, unsigned int flags, nis_cb *cb)
 300 {
 301   enum clnt_stat result;
 302   nis_error retcode;
 303
 304   if (dbp == NULL)
 305     return NIS_NAMEUNREACHABLE;
 306
 307   do
 308     {
 309     again:
 310       result = clnt_call (dbp->clnt, prog, xargs, req, xres, resp, RPCTIMEOUT);
 311
 312       if (result != RPC_SUCCESS)
 313         retcode = NIS_RPCERROR;
 314       else
 315         {
 316           switch (prog)
 317             {
 318             case NIS_IBLIST:
 319               if ((((nis_result *)resp)->status == NIS_CBRESULTS)
 320                   && (cb != NULL))
 321                 {
 322                   __nis_do_callback (dbp, &((nis_result *) resp)->cookie, cb);
 323                   break;
 324                 }
 325               /* Yes, the missing break is correct. If we doesn't have to
 326                  start a callback, look if we have to search another server */
 327               /* Fall through.  */
 328             case NIS_LOOKUP:
 329             case NIS_ADD:
 330             case NIS_MODIFY:
 331             case NIS_REMOVE:
 332             case NIS_IBADD:
 333             case NIS_IBMODIFY:
 334             case NIS_IBREMOVE:
 335             case NIS_IBFIRST:
 336             case NIS_IBNEXT:
 337               if (((nis_result *)resp)->status == NIS_SYSTEMERROR
 338                   || ((nis_result *)resp)->status == NIS_NOSUCHNAME
 339                   || ((nis_result *)resp)->status == NIS_NOT_ME)
 340                 {
 341                 next_server:
 342                   if (__nisbind_next (dbp) == NIS_SUCCESS)
 343                     {
 344                       while (__nisbind_connect (dbp) != NIS_SUCCESS)
 345                         {
 346                           if (__nisbind_next (dbp) != NIS_SUCCESS)
 347                               return NIS_SUCCESS;
 348                         }
 349                     }
 350                   else
 351                     break; /* No more servers to search in */
 352                   goto again;
 353                 }
 354               break;
 355             case NIS_FINDDIRECTORY:
 356               if (((fd_result *)resp)->status == NIS_SYSTEMERROR
 357                   || ((fd_result *)resp)->status == NIS_NOSUCHNAME
 358                   || ((fd_result *)resp)->status == NIS_NOT_ME)
 359                 goto next_server;
 360               break;
 361             case NIS_DUMPLOG: /* log_result */
 362             case NIS_DUMP:
 363               if (((log_result *)resp)->lr_status == NIS_SYSTEMERROR
 364                   || ((log_result *)resp)->lr_status == NIS_NOSUCHNAME
 365                   || ((log_result *)resp)->lr_status == NIS_NOT_ME)
 366                 goto next_server;
 367               break;
 368             default:
 369               break;
 370             }
 371           retcode = NIS_SUCCESS;
 372         }
 373     }
 374   while ((flags & HARD_LOOKUP) && retcode == NIS_RPCERROR);
 375
 376   return retcode;
 377 }
 378 libnsl_hidden_nolink_def (__do_niscall3, GLIBC_PRIVATE)
 379
 380
 381 nis_error
 382 __do_niscall2 (const nis_server *server, u_int server_len, u_long prog,
 383                xdrproc_t xargs, caddr_t req, xdrproc_t xres, caddr_t resp,
 384                unsigned int flags, nis_cb *cb)
 385 {
 386   dir_binding dbp;
 387   nis_error status;
 388
 389   if (flags & MASTER_ONLY)
 390     server_len = 1;
 391
 392   status = __nisbind_create (&dbp, server, server_len, ~0, ~0, flags);
 393   if (status != NIS_SUCCESS)
 394     return status;
 395
 396   while (__nisbind_connect (&dbp) != NIS_SUCCESS)
 397     if (__nisbind_next (&dbp) != NIS_SUCCESS)
 398       return NIS_NAMEUNREACHABLE;
 399
 400   status = __do_niscall3 (&dbp, prog, xargs, req, xres, resp, flags, cb);
 401
 402   __nisbind_destroy (&dbp);
 403
 404   return status;
 405
 406 }
 407
 408 static directory_obj *
 409 rec_dirsearch (const_nis_name name, directory_obj *dir, nis_error *status)
 410 {
 411   fd_result *fd_res;
 412   XDR xdrs;
 413
 414   switch (nis_dir_cmp (name, dir->do_name))
 415     {
 416     case SAME_NAME:
 417       *status = NIS_SUCCESS;
 418       return dir;
 419     case NOT_SEQUENTIAL:
 420       /* NOT_SEQUENTIAL means, go one up and try it there ! */
 421     case HIGHER_NAME:
 422       { /* We need data from a parent domain */
 423         directory_obj *obj;
 424         const char *ndomain = __nis_domain_of (dir->do_name);
 425
 426         /* The root server of our domain is a replica of the parent
 427            domain ! (Now I understand why a root server must be a
 428            replica of the parent domain) */
 429         fd_res = __nis_finddirectory (dir, ndomain);
 430         if (fd_res == NULL)
 431           {
 432             nis_free_directory (dir);
 433             *status = NIS_NOMEMORY;
 434             return NULL;
 435           }
 436         *status = fd_res->status;
 437         if (fd_res->status != NIS_SUCCESS)
 438           {
 439             /* Try the current directory obj, maybe it works */
 440             __free_fdresult (fd_res);
 441             return dir;
 442           }
 443         nis_free_directory (dir);
 444         obj = calloc (1, sizeof (directory_obj));
 445         if (obj == NULL)
 446           {
 447             __free_fdresult (fd_res);
 448             *status = NIS_NOMEMORY;
 449             return NULL;
 450           }
 451         xdrmem_create (&xdrs, fd_res->dir_data.dir_data_val,
 452                        fd_res->dir_data.dir_data_len, XDR_DECODE);
 453         _xdr_directory_obj (&xdrs, obj);
 454         xdr_destroy (&xdrs);
 455         __free_fdresult (fd_res);
 456
 457         /* We have found a NIS+ server serving ndomain, now
 458            let us search for "name" */
 459         return rec_dirsearch (name, obj, status);
 460       }
 461       break;
 462     case LOWER_NAME:
 463       {
 464         directory_obj *obj;
 465         size_t namelen = strlen (name);
 466         char leaf[namelen + 3];
 467         char domain[namelen + 3];
 468         const char *ndomain;
 469         char *cp;
 470
 471         strcpy (domain, name);
 472
 473         do
 474           {
 475             if (domain[0] == '\0')
 476               {
 477                 nis_free_directory (dir);
 478                 return NULL;
 479               }
 480             nis_leaf_of_r (domain, leaf, sizeof (leaf));
 481             ndomain = __nis_domain_of (domain);
 482             memmove (domain, ndomain, strlen (ndomain) + 1);
 483           }
 484         while (nis_dir_cmp (domain, dir->do_name) != SAME_NAME);
 485
 486         cp = rawmemchr (leaf, '\0');
 487         *cp++ = '.';
 488         strcpy (cp, domain);
 489
 490         fd_res = __nis_finddirectory (dir, leaf);
 491         if (fd_res == NULL)
 492           {
 493             nis_free_directory (dir);
 494             *status = NIS_NOMEMORY;
 495             return NULL;
 496           }
 497         *status = fd_res->status;
 498         if (fd_res->status != NIS_SUCCESS)
 499           {
 500             /* Try the current directory object, maybe it works */
 501             __free_fdresult (fd_res);
 502             return dir;
 503           }
 504         nis_free_directory (dir);
 505         obj = calloc (1, sizeof (directory_obj));
 506         if (obj == NULL)
 507           {
 508             __free_fdresult (fd_res);
 509             *status = NIS_NOMEMORY;
 510             return NULL;
 511           }
 512         xdrmem_create (&xdrs, fd_res->dir_data.dir_data_val,
 513                        fd_res->dir_data.dir_data_len, XDR_DECODE);
 514         _xdr_directory_obj (&xdrs, obj);
 515         xdr_destroy (&xdrs);
 516         __free_fdresult (fd_res);
 517         /* We have found a NIS+ server serving ndomain, now
 518            let us search for "name" */
 519         return rec_dirsearch (name, obj, status);
 520       }
 521       break;
 522     case BAD_NAME:
 523       nis_free_directory (dir);
 524       *status = NIS_BADNAME;
 525       return NULL;
 526     }
 527   nis_free_directory (dir);
 528   *status = NIS_FAIL;
 529   return NULL;
 530 }
 531
 532 /* We try to query the current server for the searched object,
 533    maybe he know about it ? */
 534 static directory_obj *
 535 first_shoot (const_nis_name name, directory_obj *dir)
 536 {
 537   directory_obj *obj = NULL;
 538   fd_result *fd_res;
 539   XDR xdrs;
 540
 541   if (nis_dir_cmp (name, dir->do_name) == SAME_NAME)
 542     return dir;
 543
 544   fd_res = __nis_finddirectory (dir, name);
 545   if (fd_res == NULL)
 546     return NULL;
 547   if (fd_res->status == NIS_SUCCESS
 548       && (obj = calloc (1, sizeof (directory_obj))) != NULL)
 549     {
 550       xdrmem_create (&xdrs, fd_res->dir_data.dir_data_val,
 551                      fd_res->dir_data.dir_data_len, XDR_DECODE);
 552       _xdr_directory_obj (&xdrs, obj);
 553       xdr_destroy (&xdrs);
 554
 555       if (strcmp (dir->do_name, obj->do_name) != 0)
 556         {
 557           nis_free_directory (obj);
 558           obj = NULL;
 559         }
 560     }
 561
 562   __free_fdresult (fd_res);
 563
 564   if (obj != NULL)
 565     nis_free_directory (dir);
 566
 567   return obj;
 568 }
 569
 570 static struct nis_server_cache
 571 {
 572   int search_parent;
 573   int uses;
 574   unsigned int size;
 575   unsigned int server_used;
 576   unsigned int current_ep;
 577   time_t expires;
 578   char name[];
 579 } *nis_server_cache[16];
 580 static time_t nis_cold_start_mtime;
 581 __libc_lock_define_initialized (static, nis_server_cache_lock)
 582
 583 static directory_obj *
 584 nis_server_cache_search (const_nis_name name, int search_parent,
 585                          unsigned int *server_used, unsigned int *current_ep,
 586                          struct timespec *now)
 587 {
 588   directory_obj *ret = NULL;
 589   int i;
 590   char *addr;
 591   XDR xdrs;
 592   struct stat64 st;
 593
 594   int saved_errno = errno;
 595   if (stat64 ("/var/nis/NIS_COLD_START", &st) < 0)
 596     st.st_mtime = nis_cold_start_mtime + 1;
 597   __set_errno (saved_errno);
 598
 599   __libc_lock_lock (nis_server_cache_lock);
 600
 601   for (i = 0; i < 16; ++i)
 602     if (nis_server_cache[i] == NULL)
 603       continue;
 604     else if (st.st_mtime != nis_cold_start_mtime
 605              || now->tv_sec > nis_server_cache[i]->expires)
 606       {
 607         free (nis_server_cache[i]);
 608         nis_server_cache[i] = NULL;
 609       }
 610     else if (nis_server_cache[i]->search_parent == search_parent
 611              && strcmp (nis_server_cache[i]->name, name) == 0)
 612       {
 613         ret = calloc (1, sizeof (directory_obj));
 614         if (ret == NULL)
 615           break;
 616
 617         addr = rawmemchr (nis_server_cache[i]->name, '\0') + 8;
 618         addr = (char *) ((uintptr_t) addr & ~(uintptr_t) 7);
 619         xdrmem_create (&xdrs, addr, nis_server_cache[i]->size, XDR_DECODE);
 620         if (!_xdr_directory_obj (&xdrs, ret))
 621           {
 622             xdr_destroy (&xdrs);
 623             free (ret);
 624             ret = NULL;
 625             free (nis_server_cache[i]);
 626             nis_server_cache[i] = NULL;
 627             break;
 628           }
 629         xdr_destroy (&xdrs);
 630         *server_used = nis_server_cache[i]->server_used;
 631         *current_ep = nis_server_cache[i]->current_ep;
 632         break;
 633       }
 634
 635   nis_cold_start_mtime = st.st_mtime;
 636
 637   __libc_lock_unlock (nis_server_cache_lock);
 638   return ret;
 639 }
 640
 641 static void
 642 nis_server_cache_add (const_nis_name name, int search_parent,
 643                       directory_obj *dir, unsigned int server_used,
 644                       unsigned int current_ep, struct timespec *now)
 645 {
 646   struct nis_server_cache **loc;
 647   struct nis_server_cache *new;
 648   struct nis_server_cache *old;
 649   int i;
 650   char *addr;
 651   unsigned int size;
 652   XDR xdrs;
 653
 654   if (dir == NULL)
 655     return;
 656
 657   size = xdr_sizeof ((xdrproc_t) _xdr_directory_obj, (char *) dir);
 658   new = calloc (1, sizeof (*new) + strlen (name) + 8 + size);
 659   if (new == NULL)
 660     return;
 661   new->search_parent = search_parent;
 662   new->uses = 1;
 663   new->expires = now->tv_sec + dir->do_ttl;
 664   new->size = size;
 665   new->server_used = server_used;
 666   new->current_ep = current_ep;
 667   addr = stpcpy (new->name, name) + 8;
 668   addr = (char *) ((uintptr_t) addr & ~(uintptr_t) 7);
 669
 670   xdrmem_create(&xdrs, addr, size, XDR_ENCODE);
 671   if (!_xdr_directory_obj (&xdrs, dir))
 672     {
 673       xdr_destroy (&xdrs);
 674       free (new);
 675       return;
 676     }
 677   xdr_destroy (&xdrs);
 678
 679   __libc_lock_lock (nis_server_cache_lock);
 680
 681   /* Choose which entry should be evicted from the cache.  */
 682   loc = &nis_server_cache[0];
 683   if (*loc != NULL)
 684     {
 685       for (i = 1; i < 16; ++i)
 686         if (nis_server_cache[i] == NULL)
 687           {
 688             loc = &nis_server_cache[i];
 689             break;
 690           }
 691         else if ((*loc)->uses > nis_server_cache[i]->uses
 692                  || ((*loc)->uses == nis_server_cache[i]->uses
 693                      && (*loc)->expires > nis_server_cache[i]->expires))
 694           loc = &nis_server_cache[i];
 695     }
 696   old = *loc;
 697   *loc = new;
 698
 699   __libc_lock_unlock (nis_server_cache_lock);
 700   free (old);
 701 }
 702
 703 nis_error
 704 __nisfind_server (const_nis_name name, int search_parent,
 705                   directory_obj **dir, dir_binding *dbp, unsigned int flags)
 706 {
 707   nis_error result = NIS_SUCCESS;
 708   nis_error status;
 709   directory_obj *obj;
 710   struct timespec ts;
 711   unsigned int server_used = ~0;
 712   unsigned int current_ep = ~0;
 713
 714   if (name == NULL)
 715     return NIS_BADNAME;
 716
 717   if (*dir != NULL)
 718     return NIS_SUCCESS;
 719
 720   clock_gettime (CLOCK_REALTIME, &ts);
 721
 722   if ((flags & NO_CACHE) == 0)
 723     *dir = nis_server_cache_search (name, search_parent, &server_used,
 724                                     &current_ep, &ts);
 725   if (*dir != NULL)
 726     {
 727       unsigned int server_len = (*dir)->do_servers.do_servers_len;
 728       if (flags & MASTER_ONLY)
 729         {
 730           server_len = 1;
 731           if (server_used != 0)
 732             {
 733               server_used = ~0;
 734               current_ep = ~0;
 735             }
 736         }
 737       result = __nisbind_create (dbp, (*dir)->do_servers.do_servers_val,
 738                                  server_len, server_used, current_ep, flags);
 739       if (result != NIS_SUCCESS)
 740         {
 741           nis_free_directory (*dir);
 742           *dir = NULL;
 743         }
 744       return result;
 745     }
 746
 747   int saved_errno = errno;
 748   *dir = readColdStartFile ();
 749   __set_errno (saved_errno);
 750   if (*dir == NULL)
 751     /* No /var/nis/NIS_COLD_START->no NIS+ installed.  */
 752     return NIS_UNAVAIL;
 753
 754   /* Try at first, if servers in "dir" know our object */
 755   const char *search_name = name;
 756   if (search_parent)
 757     search_name = __nis_domain_of (name);
 758   obj = first_shoot (search_name, *dir);
 759   if (obj == NULL)
 760     {
 761       obj = rec_dirsearch (search_name, *dir, &status);
 762       if (obj == NULL)
 763         result = status;
 764     }
 765
 766   if (result == NIS_SUCCESS)
 767     {
 768       unsigned int server_len = obj->do_servers.do_servers_len;
 769       if (flags & MASTER_ONLY)
 770         server_len = 1;
 771       result = __nisbind_create (dbp, obj->do_servers.do_servers_val,
 772                                  server_len, ~0, ~0, flags);
 773       if (result == NIS_SUCCESS)
 774         {
 775           if ((flags & MASTER_ONLY) == 0
 776               || obj->do_servers.do_servers_len == 1)
 777             {
 778               server_used = dbp->server_used;
 779               current_ep = dbp->current_ep;
 780             }
 781           if ((flags & NO_CACHE) == 0)
 782             nis_server_cache_add (name, search_parent, obj,
 783                                   server_used, current_ep, &ts);
 784         }
 785       else
 786         {
 787           nis_free_directory (obj);
 788           obj = NULL;
 789         }
 790     }
 791
 792   *dir = obj;
 793
 794   return result;
 795 }
 796
 797
 798 nis_error
 799 __prepare_niscall (const_nis_name name, directory_obj **dirp,
 800                    dir_binding *bptrp, unsigned int flags)
 801 {
 802   nis_error retcode = __nisfind_server (name, 1, dirp, bptrp, flags);
 803   if (__glibc_unlikely (retcode != NIS_SUCCESS))
 804     return retcode;
 805
 806   do
 807     if (__nisbind_connect (bptrp) == NIS_SUCCESS)
 808       return NIS_SUCCESS;
 809   while (__nisbind_next (bptrp) == NIS_SUCCESS);
 810
 811   __nisbind_destroy (bptrp);
 812   memset (bptrp, '\0', sizeof (*bptrp));
 813
 814   retcode = NIS_NAMEUNREACHABLE;
 815   nis_free_directory (*dirp);
 816   *dirp = NULL;
 817
 818   return retcode;
 819 }
 820 libnsl_hidden_nolink_def (__prepare_niscall, GLIBC_PRIVATE)
 821
 822
 823 nis_error
 824 __do_niscall (const_nis_name name, u_long prog, xdrproc_t xargs,
 825               caddr_t req, xdrproc_t xres, caddr_t resp, unsigned int flags,
 826               nis_cb *cb)
 827 {
 828   dir_binding bptr;
 829   directory_obj *dir = NULL;
 830   int saved_errno = errno;
 831
 832   nis_error retcode = __prepare_niscall (name, &dir, &bptr, flags);
 833   if (retcode == NIS_SUCCESS)
 834     {
 835       retcode = __do_niscall3 (&bptr, prog, xargs, req, xres, resp, flags, cb);
 836
 837       __nisbind_destroy (&bptr);
 838
 839       nis_free_directory (dir);
 840     }
 841
 842   __set_errno (saved_errno);
 843
 844   return retcode;
 845 }