nis/nis_call.c

   1 /* Copyright (C) 1997, 1998, 2001, 2004, 2005, 2006, 2007
   2    Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Thorsten Kukuk <kukuk@vt.uni-paderborn.de>, 1997.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #include <errno.h>
  22 #include <fcntl.h>
  23 #include <string.h>
  24 #include <libintl.h>
  25 #include <rpc/rpc.h>
  26 #include <rpc/auth.h>
  27 #include <rpcsvc/nis.h>
  28 #include <sys/socket.h>
  29 #include <sys/stat.h>
  30 #include <unistd.h>
  31 #include <netinet/in.h>
  32 #include <arpa/inet.h>
  33 #include <bits/libc-lock.h>
  34
  35 #include "nis_xdr.h"
  36 #include "nis_intern.h"
  37 #include <libnsl.h>
  38
  39 static const struct timeval RPCTIMEOUT = {10, 0};
  40 static const struct timeval UDPTIMEOUT = {5, 0};
  41
  42 extern u_short __pmap_getnisport (struct sockaddr_in *address, u_long program,
  43                                   u_long version, u_int protocol);
  44
  45 unsigned long int
  46 inetstr2int (const char *str)
  47 {
  48   size_t j = 0;
  49   for (size_t i = 0; str[i] != '\0'; ++i)
  50     if (str[i] == '.' && __builtin_expect (++j == 4, 0))
  51       {
  52         char buffer[i + 1];
  53         buffer[i] = '\0';
  54         return inet_addr (memcpy (buffer, str, i));
  55       }
  56
  57   return inet_addr (str);
  58 }
  59
  60 void
  61 __nisbind_destroy (dir_binding *bind)
  62 {
  63   if (bind->clnt != NULL)
  64     {
  65       if (bind->use_auth)
  66         auth_destroy (bind->clnt->cl_auth);
  67       clnt_destroy (bind->clnt);
  68     }
  69 }
  70 libnsl_hidden_def (__nisbind_destroy)
  71
  72 nis_error
  73 __nisbind_next (dir_binding *bind)
  74 {
  75   if (bind->clnt != NULL)
  76     {
  77       if (bind->use_auth)
  78         auth_destroy (bind->clnt->cl_auth);
  79       clnt_destroy (bind->clnt);
  80       bind->clnt = NULL;
  81     }
  82
  83   if (bind->trys >= bind->server_len)
  84     return NIS_FAIL;
  85
  86   for (u_int j = bind->current_ep + 1;
  87        j < bind->server_val[bind->server_used].ep.ep_len; ++j)
  88     if (strcmp (bind->server_val[bind->server_used].ep.ep_val[j].family,
  89                 "inet") == 0)
  90       if (bind->server_val[bind->server_used].ep.ep_val[j].proto[0] == '-')
  91         {
  92           bind->current_ep = j;
  93           return NIS_SUCCESS;
  94         }
  95
  96   ++bind->trys;
  97   ++bind->server_used;
  98   if (bind->server_used >= bind->server_len)
  99     bind->server_used = 0;
 100
 101   for (u_int j = 0; j < bind->server_val[bind->server_used].ep.ep_len; ++j)
 102     if (strcmp (bind->server_val[bind->server_used].ep.ep_val[j].family,
 103                 "inet") == 0)
 104       if (bind->server_val[bind->server_used].ep.ep_val[j].proto[0] == '-')
 105         {
 106           bind->current_ep = j;
 107           return NIS_SUCCESS;
 108         }
 109
 110   return NIS_FAIL;
 111 }
 112 libnsl_hidden_def (__nisbind_next)
 113
 114 static struct ckey_cache_entry
 115 {
 116   struct in_addr inaddr;
 117   in_port_t port;
 118   unsigned int protocol;
 119   des_block ckey;
 120 } *ckey_cache;
 121 static size_t ckey_cache_size;
 122 static size_t ckey_cache_allocated;
 123 static pid_t ckey_cache_pid;
 124 static uid_t ckey_cache_euid;
 125 __libc_lock_define_initialized (static, ckey_cache_lock)
 126
 127 static bool_t
 128 get_ckey (des_block *ckey, struct sockaddr_in *addr, unsigned int protocol)
 129 {
 130   size_t i;
 131   pid_t pid = getpid ();
 132   uid_t euid = geteuid ();
 133   bool_t ret = FALSE;
 134
 135   __libc_lock_lock (ckey_cache_lock);
 136
 137   if (ckey_cache_pid != pid || ckey_cache_euid != euid)
 138     {
 139       ckey_cache_size = 0;
 140       ckey_cache_pid = pid;
 141       ckey_cache_euid = euid;
 142     }
 143
 144   for (i = 0; i < ckey_cache_size; ++i)
 145     if (ckey_cache[i].port == addr->sin_port
 146         && ckey_cache[i].protocol == protocol
 147         && memcmp (&ckey_cache[i].inaddr, &addr->sin_addr,
 148                    sizeof (addr->sin_addr)) == 0)
 149       {
 150         *ckey = ckey_cache[i].ckey;
 151         ret = TRUE;
 152         break;
 153       }
 154
 155   if (!ret && key_gendes (ckey) >= 0)
 156     {
 157       ret = TRUE;
 158       /* Don't grow the cache indefinitely.  */
 159       if (ckey_cache_size == 256)
 160         ckey_cache_size = 0;
 161       if (ckey_cache_size == ckey_cache_allocated)
 162         {
 163           size_t size = ckey_cache_allocated ? ckey_cache_allocated * 2 : 16;
 164           struct ckey_cache_entry *new_cache
 165             = realloc (ckey_cache, size * sizeof (*ckey_cache));
 166           if (new_cache != NULL)
 167             {
 168               ckey_cache = new_cache;
 169               ckey_cache_allocated = size;
 170             }
 171         }
 172       ckey_cache[ckey_cache_size].inaddr = addr->sin_addr;
 173       ckey_cache[ckey_cache_size].port = addr->sin_port;
 174       ckey_cache[ckey_cache_size].protocol = protocol;
 175       ckey_cache[ckey_cache_size++].ckey = *ckey;
 176     }
 177
 178   __libc_lock_unlock (ckey_cache_lock);
 179   return ret;
 180 }
 181
 182 nis_error
 183 __nisbind_connect (dir_binding *dbp)
 184 {
 185   nis_server *serv;
 186   u_short port;
 187
 188   if (dbp == NULL)
 189     return NIS_FAIL;
 190
 191   serv = &dbp->server_val[dbp->server_used];
 192
 193   memset (&dbp->addr, '\0', sizeof (dbp->addr));
 194   dbp->addr.sin_family = AF_INET;
 195
 196   dbp->addr.sin_addr.s_addr =
 197     inetstr2int (serv->ep.ep_val[dbp->current_ep].uaddr);
 198
 199   if (dbp->addr.sin_addr.s_addr == INADDR_NONE)
 200     return NIS_FAIL;
 201
 202   /* Check, if the host is online and rpc.nisd is running. Much faster
 203      then the clnt*_create functions: */
 204   port = __pmap_getnisport (&dbp->addr, NIS_PROG, NIS_VERSION,
 205                             dbp->use_udp ? IPPROTO_UDP : IPPROTO_TCP);
 206   if (port == 0)
 207     return NIS_RPCERROR;
 208
 209   dbp->addr.sin_port = htons (port);
 210   dbp->socket = RPC_ANYSOCK;
 211   if (dbp->use_udp)
 212     dbp->clnt = clntudp_create (&dbp->addr, NIS_PROG, NIS_VERSION,
 213                                  UDPTIMEOUT, &dbp->socket);
 214   else
 215     dbp->clnt = clnttcp_create (&dbp->addr, NIS_PROG, NIS_VERSION,
 216                                  &dbp->socket, 0, 0);
 217
 218   if (dbp->clnt == NULL)
 219     return NIS_RPCERROR;
 220
 221   clnt_control (dbp->clnt, CLSET_TIMEOUT, (caddr_t) &RPCTIMEOUT);
 222   /* If the program exists, close the socket */
 223   if (fcntl (dbp->socket, F_SETFD, 1) == -1)
 224     perror ("fcntl: F_SETFD");
 225
 226   if (dbp->use_auth)
 227     {
 228       if (serv->key_type == NIS_PK_DH)
 229         {
 230           char netname[MAXNETNAMELEN + 1];
 231           char *p;
 232           des_block ckey;
 233
 234           p = stpcpy (netname, "unix@");
 235           strncpy (p, serv->name, MAXNETNAMELEN - 5);
 236           netname[MAXNETNAMELEN] = '\0';
 237           dbp->clnt->cl_auth = NULL;
 238           if (get_ckey (&ckey, &dbp->addr,
 239                         dbp->use_udp ? IPPROTO_UDP : IPPROTO_TCP))
 240             dbp->clnt->cl_auth =
 241               authdes_pk_create (netname, &serv->pkey, 300, NULL, &ckey);
 242           if (!dbp->clnt->cl_auth)
 243             dbp->clnt->cl_auth = authunix_create_default ();
 244         }
 245       else
 246         dbp->clnt->cl_auth = authunix_create_default ();
 247     }
 248
 249   return NIS_SUCCESS;
 250 }
 251 libnsl_hidden_def (__nisbind_connect)
 252
 253 nis_error
 254 __nisbind_create (dir_binding *dbp, const nis_server *serv_val,
 255                   unsigned int serv_len, unsigned int server_used,
 256                   unsigned int current_ep, unsigned int flags)
 257 {
 258   dbp->clnt = NULL;
 259
 260   dbp->server_len = serv_len;
 261   dbp->server_val = (nis_server *)serv_val;
 262
 263   if (flags & USE_DGRAM)
 264     dbp->use_udp = TRUE;
 265   else
 266     dbp->use_udp = FALSE;
 267
 268   if (flags & NO_AUTHINFO)
 269     dbp->use_auth = FALSE;
 270   else
 271     dbp->use_auth = TRUE;
 272
 273   if (flags & MASTER_ONLY)
 274     dbp->master_only = TRUE;
 275   else
 276     dbp->master_only = FALSE;
 277
 278   /* We try the first server */
 279   dbp->trys = 1;
 280
 281   dbp->class = -1;
 282   if (server_used == ~0)
 283     {
 284       if (__nis_findfastest (dbp) < 1)
 285         return NIS_NAMEUNREACHABLE;
 286     }
 287   else
 288     {
 289       dbp->server_used = server_used;
 290       dbp->current_ep = current_ep;
 291     }
 292
 293   return NIS_SUCCESS;
 294 }
 295 libnsl_hidden_def (__nisbind_create)
 296
 297 /* __nisbind_connect (dbp) must be run before calling this function !
 298    So we could use the same binding twice */
 299 nis_error
 300 __do_niscall3 (dir_binding *dbp, u_long prog, xdrproc_t xargs, caddr_t req,
 301                xdrproc_t xres, caddr_t resp, unsigned int flags, nis_cb *cb)
 302 {
 303   enum clnt_stat result;
 304   nis_error retcode;
 305
 306   if (dbp == NULL)
 307     return NIS_NAMEUNREACHABLE;
 308
 309   do
 310     {
 311     again:
 312       result = clnt_call (dbp->clnt, prog, xargs, req, xres, resp, RPCTIMEOUT);
 313
 314       if (result != RPC_SUCCESS)
 315         retcode = NIS_RPCERROR;
 316       else
 317         {
 318           switch (prog)
 319             {
 320             case NIS_IBLIST:
 321               if ((((nis_result *)resp)->status == NIS_CBRESULTS) &&
 322                   (cb != NULL))
 323                 {
 324                   __nis_do_callback (dbp, &((nis_result *) resp)->cookie, cb);
 325                   break;
 326                 }
 327               /* Yes, the missing break is correct. If we doesn't have to
 328                  start a callback, look if we have to search another server */
 329             case NIS_LOOKUP:
 330             case NIS_ADD:
 331             case NIS_MODIFY:
 332             case NIS_REMOVE:
 333             case NIS_IBADD:
 334             case NIS_IBMODIFY:
 335             case NIS_IBREMOVE:
 336             case NIS_IBFIRST:
 337             case NIS_IBNEXT:
 338               if (((nis_result *)resp)->status == NIS_SYSTEMERROR
 339                   || ((nis_result *)resp)->status == NIS_NOSUCHNAME
 340                   || ((nis_result *)resp)->status == NIS_NOT_ME)
 341                 {
 342                 next_server:
 343                   if (__nisbind_next (dbp) == NIS_SUCCESS)
 344                     {
 345                       while (__nisbind_connect (dbp) != NIS_SUCCESS)
 346                         {
 347                           if (__nisbind_next (dbp) != NIS_SUCCESS)
 348                               return NIS_SUCCESS;
 349                         }
 350                     }
 351                   else
 352                     break; /* No more servers to search in */
 353                   goto again;
 354                 }
 355               break;
 356             case NIS_FINDDIRECTORY:
 357               if (((fd_result *)resp)->status == NIS_SYSTEMERROR
 358                   || ((fd_result *)resp)->status == NIS_NOSUCHNAME
 359                   || ((fd_result *)resp)->status == NIS_NOT_ME)
 360                 goto next_server;
 361               break;
 362             case NIS_DUMPLOG: /* log_result */
 363             case NIS_DUMP:
 364               if (((log_result *)resp)->lr_status == NIS_SYSTEMERROR
 365                   || ((log_result *)resp)->lr_status == NIS_NOSUCHNAME
 366                   || ((log_result *)resp)->lr_status == NIS_NOT_ME)
 367                 goto next_server;
 368               break;
 369             default:
 370               break;
 371             }
 372           retcode = NIS_SUCCESS;
 373         }
 374     }
 375   while ((flags & HARD_LOOKUP) && retcode == NIS_RPCERROR);
 376
 377   return retcode;
 378 }
 379 libnsl_hidden_def (__do_niscall3)
 380
 381
 382 nis_error
 383 __do_niscall2 (const nis_server *server, u_int server_len, u_long prog,
 384                xdrproc_t xargs, caddr_t req, xdrproc_t xres, caddr_t resp,
 385                unsigned int flags, nis_cb *cb)
 386 {
 387   dir_binding dbp;
 388   nis_error status;
 389
 390   if (flags & MASTER_ONLY)
 391     server_len = 1;
 392
 393   status = __nisbind_create (&dbp, server, server_len, ~0, ~0, flags);
 394   if (status != NIS_SUCCESS)
 395     return status;
 396
 397   while (__nisbind_connect (&dbp) != NIS_SUCCESS)
 398     if (__nisbind_next (&dbp) != NIS_SUCCESS)
 399       return NIS_NAMEUNREACHABLE;
 400
 401   status = __do_niscall3 (&dbp, prog, xargs, req, xres, resp, flags, cb);
 402
 403   __nisbind_destroy (&dbp);
 404
 405   return status;
 406
 407 }
 408
 409 static directory_obj *
 410 rec_dirsearch (const_nis_name name, directory_obj *dir, nis_error *status)
 411 {
 412   fd_result *fd_res;
 413   XDR xdrs;
 414
 415   switch (nis_dir_cmp (name, dir->do_name))
 416     {
 417     case SAME_NAME:
 418       *status = NIS_SUCCESS;
 419       return dir;
 420     case NOT_SEQUENTIAL:
 421       /* NOT_SEQUENTIAL means, go one up and try it there ! */
 422     case HIGHER_NAME:
 423       { /* We need data from a parent domain */
 424         directory_obj *obj;
 425         const char *ndomain = __nis_domain_of (dir->do_name);
 426
 427         /* The root server of our domain is a replica of the parent
 428            domain ! (Now I understand why a root server must be a
 429            replica of the parent domain) */
 430         fd_res = __nis_finddirectory (dir, ndomain);
 431         if (fd_res == NULL)
 432           {
 433             nis_free_directory (dir);
 434             *status = NIS_NOMEMORY;
 435             return NULL;
 436           }
 437         *status = fd_res->status;
 438         if (fd_res->status != NIS_SUCCESS)
 439           {
 440             /* Try the current directory obj, maybe it works */
 441             __free_fdresult (fd_res);
 442             return dir;
 443           }
 444         nis_free_directory (dir);
 445         obj = calloc (1, sizeof (directory_obj));
 446         if (obj == NULL)
 447           {
 448             __free_fdresult (fd_res);
 449             *status = NIS_NOMEMORY;
 450             return NULL;
 451           }
 452         xdrmem_create (&xdrs, fd_res->dir_data.dir_data_val,
 453                        fd_res->dir_data.dir_data_len, XDR_DECODE);
 454         _xdr_directory_obj (&xdrs, obj);
 455         xdr_destroy (&xdrs);
 456         __free_fdresult (fd_res);
 457
 458         /* We have found a NIS+ server serving ndomain, now
 459            let us search for "name" */
 460         return rec_dirsearch (name, obj, status);
 461       }
 462       break;
 463     case LOWER_NAME:
 464       {
 465         directory_obj *obj;
 466         size_t namelen = strlen (name);
 467         char leaf[namelen + 3];
 468         char domain[namelen + 3];
 469         const char *ndomain;
 470         char *cp;
 471
 472         strcpy (domain, name);
 473
 474         do
 475           {
 476             if (domain[0] == '\0')
 477               {
 478                 nis_free_directory (dir);
 479                 return NULL;
 480               }
 481             nis_leaf_of_r (domain, leaf, sizeof (leaf));
 482             ndomain = __nis_domain_of (domain);
 483             memmove (domain, ndomain, strlen (ndomain) + 1);
 484           }
 485         while (nis_dir_cmp (domain, dir->do_name) != SAME_NAME);
 486
 487         cp = rawmemchr (leaf, '\0');
 488         *cp++ = '.';
 489         strcpy (cp, domain);
 490
 491         fd_res = __nis_finddirectory (dir, leaf);
 492         if (fd_res == NULL)
 493           {
 494             nis_free_directory (dir);
 495             *status = NIS_NOMEMORY;
 496             return NULL;
 497           }
 498         *status = fd_res->status;
 499         if (fd_res->status != NIS_SUCCESS)
 500           {
 501             /* Try the current directory object, maybe it works */
 502             __free_fdresult (fd_res);
 503             return dir;
 504           }
 505         nis_free_directory (dir);
 506         obj = calloc (1, sizeof(directory_obj));
 507         if (obj == NULL)
 508           {
 509             __free_fdresult (fd_res);
 510             *status = NIS_NOMEMORY;
 511             return NULL;
 512           }
 513         xdrmem_create (&xdrs, fd_res->dir_data.dir_data_val,
 514                        fd_res->dir_data.dir_data_len, XDR_DECODE);
 515         _xdr_directory_obj (&xdrs, obj);
 516         xdr_destroy (&xdrs);
 517         __free_fdresult (fd_res);
 518         /* We have found a NIS+ server serving ndomain, now
 519            let us search for "name" */
 520         return rec_dirsearch (name, obj, status);
 521       }
 522       break;
 523     case BAD_NAME:
 524       nis_free_directory (dir);
 525       *status = NIS_BADNAME;
 526       return NULL;
 527     }
 528   nis_free_directory (dir);
 529   *status = NIS_FAIL;
 530   return NULL;
 531 }
 532
 533 /* We try to query the current server for the searched object,
 534    maybe he know about it ? */
 535 static directory_obj *
 536 first_shoot (const_nis_name name, directory_obj *dir)
 537 {
 538   directory_obj *obj = NULL;
 539   fd_result *fd_res;
 540   XDR xdrs;
 541
 542   if (nis_dir_cmp (name, dir->do_name) == SAME_NAME)
 543     return dir;
 544
 545   fd_res = __nis_finddirectory (dir, name);
 546   if (fd_res == NULL)
 547     return NULL;
 548   if (fd_res->status == NIS_SUCCESS
 549       && (obj = calloc (1, sizeof (directory_obj))) != NULL)
 550     {
 551       xdrmem_create (&xdrs, fd_res->dir_data.dir_data_val,
 552                      fd_res->dir_data.dir_data_len, XDR_DECODE);
 553       _xdr_directory_obj (&xdrs, obj);
 554       xdr_destroy (&xdrs);
 555
 556       if (strcmp (dir->do_name, obj->do_name) != 0)
 557         {
 558           nis_free_directory (obj);
 559           obj = NULL;
 560         }
 561     }
 562
 563   __free_fdresult (fd_res);
 564
 565   if (obj != NULL)
 566     nis_free_directory (dir);
 567
 568   return obj;
 569 }
 570
 571 static struct nis_server_cache
 572 {
 573   int search_parent;
 574   int uses;
 575   unsigned int size;
 576   unsigned int server_used;
 577   unsigned int current_ep;
 578   time_t expires;
 579   char name[];
 580 } *nis_server_cache[16];
 581 static time_t nis_cold_start_mtime;
 582 __libc_lock_define_initialized (static, nis_server_cache_lock)
 583
 584 static directory_obj *
 585 nis_server_cache_search (const_nis_name name, int search_parent,
 586                          unsigned int *server_used, unsigned int *current_ep,
 587                          struct timeval *now)
 588 {
 589   directory_obj *ret = NULL;
 590   int i;
 591   char *addr;
 592   XDR xdrs;
 593   struct stat64 st;
 594
 595   if (stat64 ("/var/nis/NIS_COLD_START", &st) < 0)
 596     st.st_mtime = nis_cold_start_mtime + 1;
 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   *dir = readColdStartFile ();
 745   if (*dir == NULL)
 746     /* No /var/nis/NIS_COLD_START->no NIS+ installed.  */
 747     return NIS_UNAVAIL;
 748
 749   /* Try at first, if servers in "dir" know our object */
 750   const char *search_name = name;
 751   if (search_parent)
 752     search_name = __nis_domain_of (name);
 753   obj = first_shoot (search_name, *dir);
 754   if (obj == NULL)
 755     {
 756       obj = rec_dirsearch (search_name, *dir, &status);
 757       if (obj == NULL)
 758         result = status;
 759     }
 760
 761   if (result == NIS_SUCCESS)
 762     {
 763       unsigned int server_len = obj->do_servers.do_servers_len;
 764       if (flags & MASTER_ONLY)
 765         server_len = 1;
 766       result = __nisbind_create (dbp, obj->do_servers.do_servers_val,
 767                                  server_len, ~0, ~0, flags);
 768       if (result == NIS_SUCCESS)
 769         {
 770           if ((flags & MASTER_ONLY) == 0
 771               || obj->do_servers.do_servers_len == 1)
 772             {
 773               server_used = dbp->server_used;
 774               current_ep = dbp->current_ep;
 775             }
 776           if ((flags & NO_CACHE) == 0)
 777             nis_server_cache_add (name, search_parent, obj,
 778                                   server_used, current_ep, &now);
 779         }
 780       else
 781         {
 782           nis_free_directory (obj);
 783           obj = NULL;
 784         }
 785     }
 786
 787   *dir = obj;
 788
 789   return result;
 790 }
 791
 792
 793 nis_error
 794 __prepare_niscall (const_nis_name name, directory_obj **dirp,
 795                    dir_binding *bptrp, unsigned int flags)
 796 {
 797   nis_error retcode = __nisfind_server (name, 1, dirp, bptrp, flags);
 798   if (__builtin_expect (retcode != NIS_SUCCESS, 0))
 799     return retcode;
 800
 801   do
 802     if (__nisbind_connect (bptrp) == NIS_SUCCESS)
 803       return NIS_SUCCESS;
 804   while (__nisbind_next (bptrp) == NIS_SUCCESS);
 805
 806   __nisbind_destroy (bptrp);
 807   memset (bptrp, '\0', sizeof (*bptrp));
 808
 809   retcode = NIS_NAMEUNREACHABLE;
 810   nis_free_directory (*dirp);
 811   *dirp = NULL;
 812
 813   return retcode;
 814 }
 815 libnsl_hidden_def (__prepare_niscall)
 816
 817
 818 nis_error
 819 __do_niscall (const_nis_name name, u_long prog, xdrproc_t xargs,
 820               caddr_t req, xdrproc_t xres, caddr_t resp, unsigned int flags,
 821               nis_cb *cb)
 822 {
 823   dir_binding bptr;
 824   directory_obj *dir = NULL;
 825   int saved_errno = errno;
 826
 827   nis_error retcode = __prepare_niscall (name, &dir, &bptr, flags);
 828   if (retcode == NIS_SUCCESS)
 829     {
 830       retcode = __do_niscall3 (&bptr, prog, xargs, req, xres, resp, flags, cb);
 831
 832       __nisbind_destroy (&bptr);
 833
 834       nis_free_directory (dir);
 835     }
 836
 837   __set_errno (saved_errno);
 838
 839   return retcode;
 840 }