nis/nis_call.c

   1 /* Copyright (C) 1997-2015 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Thorsten Kukuk <kukuk@vt.uni-paderborn.de>, 1997.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include <fcntl.h>
  21 #include <string.h>
  22 #include <libintl.h>
  23 #include <rpc/rpc.h>
  24 #include <rpc/auth.h>
  25 #include <rpcsvc/nis.h>
  26 #include <sys/socket.h>
  27 #include <sys/stat.h>
  28 #include <unistd.h>
  29 #include <netinet/in.h>
  30 #include <arpa/inet.h>
  31 #include <bits/libc-lock.h>
  32
  33 #include "nis_xdr.h"
  34 #include "nis_intern.h"
  35 #include <libnsl.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_def (__nisbind_destroy)
  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_def (__nisbind_next)
 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_def (__nisbind_connect)
 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_def (__nisbind_create)
 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             case NIS_LOOKUP:
 328             case NIS_ADD:
 329             case NIS_MODIFY:
 330             case NIS_REMOVE:
 331             case NIS_IBADD:
 332             case NIS_IBMODIFY:
 333             case NIS_IBREMOVE:
 334             case NIS_IBFIRST:
 335             case NIS_IBNEXT:
 336               if (((nis_result *)resp)->status == NIS_SYSTEMERROR
 337                   || ((nis_result *)resp)->status == NIS_NOSUCHNAME
 338                   || ((nis_result *)resp)->status == NIS_NOT_ME)
 339                 {
 340                 next_server:
 341                   if (__nisbind_next (dbp) == NIS_SUCCESS)
 342                     {
 343                       while (__nisbind_connect (dbp) != NIS_SUCCESS)
 344                         {
 345                           if (__nisbind_next (dbp) != NIS_SUCCESS)
 346                               return NIS_SUCCESS;
 347                         }
 348                     }
 349                   else
 350                     break; /* No more servers to search in */
 351                   goto again;
 352                 }
 353               break;
 354             case NIS_FINDDIRECTORY:
 355               if (((fd_result *)resp)->status == NIS_SYSTEMERROR
 356                   || ((fd_result *)resp)->status == NIS_NOSUCHNAME
 357                   || ((fd_result *)resp)->status == NIS_NOT_ME)
 358                 goto next_server;
 359               break;
 360             case NIS_DUMPLOG: /* log_result */
 361             case NIS_DUMP:
 362               if (((log_result *)resp)->lr_status == NIS_SYSTEMERROR
 363                   || ((log_result *)resp)->lr_status == NIS_NOSUCHNAME
 364                   || ((log_result *)resp)->lr_status == NIS_NOT_ME)
 365                 goto next_server;
 366               break;
 367             default:
 368               break;
 369             }
 370           retcode = NIS_SUCCESS;
 371         }
 372     }
 373   while ((flags & HARD_LOOKUP) && retcode == NIS_RPCERROR);
 374
 375   return retcode;
 376 }
 377 libnsl_hidden_def (__do_niscall3)
 378
 379
 380 nis_error
 381 __do_niscall2 (const nis_server *server, u_int server_len, u_long prog,
 382                xdrproc_t xargs, caddr_t req, xdrproc_t xres, caddr_t resp,
 383                unsigned int flags, nis_cb *cb)
 384 {
 385   dir_binding dbp;
 386   nis_error status;
 387
 388   if (flags & MASTER_ONLY)
 389     server_len = 1;
 390
 391   status = __nisbind_create (&dbp, server, server_len, ~0, ~0, flags);
 392   if (status != NIS_SUCCESS)
 393     return status;
 394
 395   while (__nisbind_connect (&dbp) != NIS_SUCCESS)
 396     if (__nisbind_next (&dbp) != NIS_SUCCESS)
 397       return NIS_NAMEUNREACHABLE;
 398
 399   status = __do_niscall3 (&dbp, prog, xargs, req, xres, resp, flags, cb);
 400
 401   __nisbind_destroy (&dbp);
 402
 403   return status;
 404
 405 }
 406
 407 static directory_obj *
 408 rec_dirsearch (const_nis_name name, directory_obj *dir, nis_error *status)
 409 {
 410   fd_result *fd_res;
 411   XDR xdrs;
 412
 413   switch (nis_dir_cmp (name, dir->do_name))
 414     {
 415     case SAME_NAME:
 416       *status = NIS_SUCCESS;
 417       return dir;
 418     case NOT_SEQUENTIAL:
 419       /* NOT_SEQUENTIAL means, go one up and try it there ! */
 420     case HIGHER_NAME:
 421       { /* We need data from a parent domain */
 422         directory_obj *obj;
 423         const char *ndomain = __nis_domain_of (dir->do_name);
 424
 425         /* The root server of our domain is a replica of the parent
 426            domain ! (Now I understand why a root server must be a
 427            replica of the parent domain) */
 428         fd_res = __nis_finddirectory (dir, ndomain);
 429         if (fd_res == NULL)
 430           {
 431             nis_free_directory (dir);
 432             *status = NIS_NOMEMORY;
 433             return NULL;
 434           }
 435         *status = fd_res->status;
 436         if (fd_res->status != NIS_SUCCESS)
 437           {
 438             /* Try the current directory obj, maybe it works */
 439             __free_fdresult (fd_res);
 440             return dir;
 441           }
 442         nis_free_directory (dir);
 443         obj = calloc (1, sizeof (directory_obj));
 444         if (obj == NULL)
 445           {
 446             __free_fdresult (fd_res);
 447             *status = NIS_NOMEMORY;
 448             return NULL;
 449           }
 450         xdrmem_create (&xdrs, fd_res->dir_data.dir_data_val,
 451                        fd_res->dir_data.dir_data_len, XDR_DECODE);
 452         _xdr_directory_obj (&xdrs, obj);
 453         xdr_destroy (&xdrs);
 454         __free_fdresult (fd_res);
 455
 456         /* We have found a NIS+ server serving ndomain, now
 457            let us search for "name" */
 458         return rec_dirsearch (name, obj, status);
 459       }
 460       break;
 461     case LOWER_NAME:
 462       {
 463         directory_obj *obj;
 464         size_t namelen = strlen (name);
 465         char leaf[namelen + 3];
 466         char domain[namelen + 3];
 467         const char *ndomain;
 468         char *cp;
 469
 470         strcpy (domain, name);
 471
 472         do
 473           {
 474             if (domain[0] == '\0')
 475               {
 476                 nis_free_directory (dir);
 477                 return NULL;
 478               }
 479             nis_leaf_of_r (domain, leaf, sizeof (leaf));
 480             ndomain = __nis_domain_of (domain);
 481             memmove (domain, ndomain, strlen (ndomain) + 1);
 482           }
 483         while (nis_dir_cmp (domain, dir->do_name) != SAME_NAME);
 484
 485         cp = rawmemchr (leaf, '\0');
 486         *cp++ = '.';
 487         strcpy (cp, domain);
 488
 489         fd_res = __nis_finddirectory (dir, leaf);
 490         if (fd_res == NULL)
 491           {
 492             nis_free_directory (dir);
 493             *status = NIS_NOMEMORY;
 494             return NULL;
 495           }
 496         *status = fd_res->status;
 497         if (fd_res->status != NIS_SUCCESS)
 498           {
 499             /* Try the current directory object, maybe it works */
 500             __free_fdresult (fd_res);
 501             return dir;
 502           }
 503         nis_free_directory (dir);
 504         obj = calloc (1, sizeof(directory_obj));
 505         if (obj == NULL)
 506           {
 507             __free_fdresult (fd_res);
 508             *status = NIS_NOMEMORY;
 509             return NULL;
 510           }
 511         xdrmem_create (&xdrs, fd_res->dir_data.dir_data_val,
 512                        fd_res->dir_data.dir_data_len, XDR_DECODE);
 513         _xdr_directory_obj (&xdrs, obj);
 514         xdr_destroy (&xdrs);
 515         __free_fdresult (fd_res);
 516         /* We have found a NIS+ server serving ndomain, now
 517            let us search for "name" */
 518         return rec_dirsearch (name, obj, status);
 519       }
 520       break;
 521     case BAD_NAME:
 522       nis_free_directory (dir);
 523       *status = NIS_BADNAME;
 524       return NULL;
 525     }
 526   nis_free_directory (dir);
 527   *status = NIS_FAIL;
 528   return NULL;
 529 }
 530
 531 /* We try to query the current server for the searched object,
 532    maybe he know about it ? */
 533 static directory_obj *
 534 first_shoot (const_nis_name name, directory_obj *dir)
 535 {
 536   directory_obj *obj = NULL;
 537   fd_result *fd_res;
 538   XDR xdrs;
 539
 540   if (nis_dir_cmp (name, dir->do_name) == SAME_NAME)
 541     return dir;
 542
 543   fd_res = __nis_finddirectory (dir, name);
 544   if (fd_res == NULL)
 545     return NULL;
 546   if (fd_res->status == NIS_SUCCESS
 547       && (obj = calloc (1, sizeof (directory_obj))) != NULL)
 548     {
 549       xdrmem_create (&xdrs, fd_res->dir_data.dir_data_val,
 550                      fd_res->dir_data.dir_data_len, XDR_DECODE);
 551       _xdr_directory_obj (&xdrs, obj);
 552       xdr_destroy (&xdrs);
 553
 554       if (strcmp (dir->do_name, obj->do_name) != 0)
 555         {
 556           nis_free_directory (obj);
 557           obj = NULL;
 558         }
 559     }
 560
 561   __free_fdresult (fd_res);
 562
 563   if (obj != NULL)
 564     nis_free_directory (dir);
 565
 566   return obj;
 567 }
 568
 569 static struct nis_server_cache
 570 {
 571   int search_parent;
 572   int uses;
 573   unsigned int size;
 574   unsigned int server_used;
 575   unsigned int current_ep;
 576   time_t expires;
 577   char name[];
 578 } *nis_server_cache[16];
 579 static time_t nis_cold_start_mtime;
 580 __libc_lock_define_initialized (static, nis_server_cache_lock)
 581
 582 static directory_obj *
 583 nis_server_cache_search (const_nis_name name, int search_parent,
 584                          unsigned int *server_used, unsigned int *current_ep,
 585                          struct timeval *now)
 586 {
 587   directory_obj *ret = NULL;
 588   int i;
 589   char *addr;
 590   XDR xdrs;
 591   struct stat64 st;
 592
 593   int saved_errno = errno;
 594   if (stat64 ("/var/nis/NIS_COLD_START", &st) < 0)
 595     st.st_mtime = nis_cold_start_mtime + 1;
 596   __set_errno (saved_errno);
 597
 598   __libc_lock_lock (nis_server_cache_lock);
 599
 600   for (i = 0; i < 16; ++i)
 601     if (nis_server_cache[i] == NULL)
 602       continue;
 603     else if (st.st_mtime != nis_cold_start_mtime
 604              || now->tv_sec > nis_server_cache[i]->expires)
 605       {
 606         free (nis_server_cache[i]);
 607         nis_server_cache[i] = NULL;
 608       }
 609     else if (nis_server_cache[i]->search_parent == search_parent
 610              && strcmp (nis_server_cache[i]->name, name) == 0)
 611       {
 612         ret = calloc (1, sizeof (directory_obj));
 613         if (ret == NULL)
 614           break;
 615
 616         addr = rawmemchr (nis_server_cache[i]->name, '\0') + 8;
 617         addr = (char *) ((uintptr_t) addr & ~(uintptr_t) 7);
 618         xdrmem_create (&xdrs, addr, nis_server_cache[i]->size, XDR_DECODE);
 619         if (!_xdr_directory_obj (&xdrs, ret))
 620           {
 621             xdr_destroy (&xdrs);
 622             free (ret);
 623             ret = NULL;
 624             free (nis_server_cache[i]);
 625             nis_server_cache[i] = NULL;
 626             break;
 627           }
 628         xdr_destroy (&xdrs);
 629         *server_used = nis_server_cache[i]->server_used;
 630         *current_ep = nis_server_cache[i]->current_ep;
 631         break;
 632       }
 633
 634   nis_cold_start_mtime = st.st_mtime;
 635
 636   __libc_lock_unlock (nis_server_cache_lock);
 637   return ret;
 638 }
 639
 640 static void
 641 nis_server_cache_add (const_nis_name name, int search_parent,
 642                       directory_obj *dir, unsigned int server_used,
 643                       unsigned int current_ep, struct timeval *now)
 644 {
 645   struct nis_server_cache **loc;
 646   struct nis_server_cache *new;
 647   struct nis_server_cache *old;
 648   int i;
 649   char *addr;
 650   unsigned int size;
 651   XDR xdrs;
 652
 653   if (dir == NULL)
 654     return;
 655
 656   size = xdr_sizeof ((xdrproc_t) _xdr_directory_obj, (char *) dir);
 657   new = calloc (1, sizeof (*new) + strlen (name) + 8 + size);
 658   if (new == NULL)
 659     return;
 660   new->search_parent = search_parent;
 661   new->uses = 1;
 662   new->expires = now->tv_sec + dir->do_ttl;
 663   new->size = size;
 664   new->server_used = server_used;
 665   new->current_ep = current_ep;
 666   addr = stpcpy (new->name, name) + 8;
 667   addr = (char *) ((uintptr_t) addr & ~(uintptr_t) 7);
 668
 669   xdrmem_create(&xdrs, addr, size, XDR_ENCODE);
 670   if (!_xdr_directory_obj (&xdrs, dir))
 671     {
 672       xdr_destroy (&xdrs);
 673       free (new);
 674       return;
 675     }
 676   xdr_destroy (&xdrs);
 677
 678   __libc_lock_lock (nis_server_cache_lock);
 679
 680   /* Choose which entry should be evicted from the cache.  */
 681   loc = &nis_server_cache[0];
 682   if (*loc != NULL)
 683     for (i = 1; i < 16; ++i)
 684       if (nis_server_cache[i] == NULL)
 685         {
 686           loc = &nis_server_cache[i];
 687           break;
 688         }
 689       else if ((*loc)->uses > nis_server_cache[i]->uses
 690                || ((*loc)->uses == nis_server_cache[i]->uses
 691                    && (*loc)->expires > nis_server_cache[i]->expires))
 692         loc = &nis_server_cache[i];
 693   old = *loc;
 694   *loc = new;
 695
 696   __libc_lock_unlock (nis_server_cache_lock);
 697   free (old);
 698 }
 699
 700 nis_error
 701 __nisfind_server (const_nis_name name, int search_parent,
 702                   directory_obj **dir, dir_binding *dbp, unsigned int flags)
 703 {
 704   nis_error result = NIS_SUCCESS;
 705   nis_error status;
 706   directory_obj *obj;
 707   struct timeval now;
 708   unsigned int server_used = ~0;
 709   unsigned int current_ep = ~0;
 710
 711   if (name == NULL)
 712     return NIS_BADNAME;
 713
 714   if (*dir != NULL)
 715     return NIS_SUCCESS;
 716
 717   (void) gettimeofday (&now, NULL);
 718
 719   if ((flags & NO_CACHE) == 0)
 720     *dir = nis_server_cache_search (name, search_parent, &server_used,
 721                                     &current_ep, &now);
 722   if (*dir != NULL)
 723     {
 724       unsigned int server_len = (*dir)->do_servers.do_servers_len;
 725       if (flags & MASTER_ONLY)
 726         {
 727           server_len = 1;
 728           if (server_used != 0)
 729             {
 730               server_used = ~0;
 731               current_ep = ~0;
 732             }
 733         }
 734       result = __nisbind_create (dbp, (*dir)->do_servers.do_servers_val,
 735                                  server_len, server_used, current_ep, flags);
 736       if (result != NIS_SUCCESS)
 737         {
 738           nis_free_directory (*dir);
 739           *dir = NULL;
 740         }
 741       return result;
 742     }
 743
 744   int saved_errno = errno;
 745   *dir = readColdStartFile ();
 746   __set_errno (saved_errno);
 747   if (*dir == NULL)
 748     /* No /var/nis/NIS_COLD_START->no NIS+ installed.  */
 749     return NIS_UNAVAIL;
 750
 751   /* Try at first, if servers in "dir" know our object */
 752   const char *search_name = name;
 753   if (search_parent)
 754     search_name = __nis_domain_of (name);
 755   obj = first_shoot (search_name, *dir);
 756   if (obj == NULL)
 757     {
 758       obj = rec_dirsearch (search_name, *dir, &status);
 759       if (obj == NULL)
 760         result = status;
 761     }
 762
 763   if (result == NIS_SUCCESS)
 764     {
 765       unsigned int server_len = obj->do_servers.do_servers_len;
 766       if (flags & MASTER_ONLY)
 767         server_len = 1;
 768       result = __nisbind_create (dbp, obj->do_servers.do_servers_val,
 769                                  server_len, ~0, ~0, flags);
 770       if (result == NIS_SUCCESS)
 771         {
 772           if ((flags & MASTER_ONLY) == 0
 773               || obj->do_servers.do_servers_len == 1)
 774             {
 775               server_used = dbp->server_used;
 776               current_ep = dbp->current_ep;
 777             }
 778           if ((flags & NO_CACHE) == 0)
 779             nis_server_cache_add (name, search_parent, obj,
 780                                   server_used, current_ep, &now);
 781         }
 782       else
 783         {
 784           nis_free_directory (obj);
 785           obj = NULL;
 786         }
 787     }
 788
 789   *dir = obj;
 790
 791   return result;
 792 }
 793
 794
 795 nis_error
 796 __prepare_niscall (const_nis_name name, directory_obj **dirp,
 797                    dir_binding *bptrp, unsigned int flags)
 798 {
 799   nis_error retcode = __nisfind_server (name, 1, dirp, bptrp, flags);
 800   if (__glibc_unlikely (retcode != NIS_SUCCESS))
 801     return retcode;
 802
 803   do
 804     if (__nisbind_connect (bptrp) == NIS_SUCCESS)
 805       return NIS_SUCCESS;
 806   while (__nisbind_next (bptrp) == NIS_SUCCESS);
 807
 808   __nisbind_destroy (bptrp);
 809   memset (bptrp, '\0', sizeof (*bptrp));
 810
 811   retcode = NIS_NAMEUNREACHABLE;
 812   nis_free_directory (*dirp);
 813   *dirp = NULL;
 814
 815   return retcode;
 816 }
 817 libnsl_hidden_def (__prepare_niscall)
 818
 819
 820 nis_error
 821 __do_niscall (const_nis_name name, u_long prog, xdrproc_t xargs,
 822               caddr_t req, xdrproc_t xres, caddr_t resp, unsigned int flags,
 823               nis_cb *cb)
 824 {
 825   dir_binding bptr;
 826   directory_obj *dir = NULL;
 827   int saved_errno = errno;
 828
 829   nis_error retcode = __prepare_niscall (name, &dir, &bptr, flags);
 830   if (retcode == NIS_SUCCESS)
 831     {
 832       retcode = __do_niscall3 (&bptr, prog, xargs, req, xres, resp, flags, cb);
 833
 834       __nisbind_destroy (&bptr);
 835
 836       nis_free_directory (dir);
 837     }
 838
 839   __set_errno (saved_errno);
 840
 841   return retcode;
 842 }