nis/nis_call.c

   1 /* Copyright (C) 1997, 1998, 2001, 2004, 2005, 2006, 2007, 2008
   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, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include <errno.h>
  21 #include <fcntl.h>
  22 #include <string.h>
  23 #include <libintl.h>
  24 #include <rpc/rpc.h>
  25 #include <rpc/auth.h>
  26 #include <rpcsvc/nis.h>
  27 #include <sys/socket.h>
  28 #include <sys/stat.h>
  29 #include <unistd.h>
  30 #include <netinet/in.h>
  31 #include <arpa/inet.h>
  32 #include <bits/libc-lock.h>
  33
  34 #include "nis_xdr.h"
  35 #include "nis_intern.h"
  36 #include <libnsl.h>
  37
  38 static const struct timeval RPCTIMEOUT = {10, 0};
  39 static const struct timeval UDPTIMEOUT = {5, 0};
  40
  41 extern u_short __pmap_getnisport (struct sockaddr_in *address, u_long program,
  42                                   u_long version, u_int protocol);
  43
  44 unsigned long int
  45 inetstr2int (const char *str)
  46 {
  47   size_t j = 0;
  48   for (size_t i = 0; str[i] != '\0'; ++i)
  49     if (str[i] == '.' && __builtin_expect (++j == 4, 0))
  50       {
  51         char buffer[i + 1];
  52         buffer[i] = '\0';
  53         return inet_addr (memcpy (buffer, str, i));
  54       }
  55
  56   return inet_addr (str);
  57 }
  58
  59 void
  60 __nisbind_destroy (dir_binding *bind)
  61 {
  62   if (bind->clnt != NULL)
  63     {
  64       if (bind->use_auth)
  65         auth_destroy (bind->clnt->cl_auth);
  66       clnt_destroy (bind->clnt);
  67     }
  68 }
  69 libnsl_hidden_def (__nisbind_destroy)
  70
  71 nis_error
  72 __nisbind_next (dir_binding *bind)
  73 {
  74   if (bind->clnt != NULL)
  75     {
  76       if (bind->use_auth)
  77         auth_destroy (bind->clnt->cl_auth);
  78       clnt_destroy (bind->clnt);
  79       bind->clnt = NULL;
  80     }
  81
  82   if (bind->trys >= bind->server_len)
  83     return NIS_FAIL;
  84
  85   for (u_int j = bind->current_ep + 1;
  86        j < bind->server_val[bind->server_used].ep.ep_len; ++j)
  87     if (strcmp (bind->server_val[bind->server_used].ep.ep_val[j].family,
  88                 "inet") == 0)
  89       if (bind->server_val[bind->server_used].ep.ep_val[j].proto[0] == '-')
  90         {
  91           bind->current_ep = j;
  92           return NIS_SUCCESS;
  93         }
  94
  95   ++bind->trys;
  96   ++bind->server_used;
  97   if (bind->server_used >= bind->server_len)
  98     bind->server_used = 0;
  99
 100   for (u_int j = 0; j < bind->server_val[bind->server_used].ep.ep_len; ++j)
 101     if (strcmp (bind->server_val[bind->server_used].ep.ep_val[j].family,
 102                 "inet") == 0)
 103       if (bind->server_val[bind->server_used].ep.ep_val[j].proto[0] == '-')
 104         {
 105           bind->current_ep = j;
 106           return NIS_SUCCESS;
 107         }
 108
 109   return NIS_FAIL;
 110 }
 111 libnsl_hidden_def (__nisbind_next)
 112
 113 static struct ckey_cache_entry
 114 {
 115   struct in_addr inaddr;
 116   in_port_t port;
 117   unsigned int protocol;
 118   des_block ckey;
 119 } *ckey_cache;
 120 static size_t ckey_cache_size;
 121 static size_t ckey_cache_allocated;
 122 static pid_t ckey_cache_pid;
 123 static uid_t ckey_cache_euid;
 124 __libc_lock_define_initialized (static, ckey_cache_lock)
 125
 126 static bool_t
 127 get_ckey (des_block *ckey, struct sockaddr_in *addr, unsigned int protocol)
 128 {
 129   size_t i;
 130   pid_t pid = getpid ();
 131   uid_t euid = geteuid ();
 132   bool_t ret = FALSE;
 133
 134   __libc_lock_lock (ckey_cache_lock);
 135
 136   if (ckey_cache_pid != pid || ckey_cache_euid != euid)
 137     {
 138       ckey_cache_size = 0;
 139       ckey_cache_pid = pid;
 140       ckey_cache_euid = euid;
 141     }
 142
 143   for (i = 0; i < ckey_cache_size; ++i)
 144     if (ckey_cache[i].port == addr->sin_port
 145         && ckey_cache[i].protocol == protocol
 146         && memcmp (&ckey_cache[i].inaddr, &addr->sin_addr,
 147                    sizeof (addr->sin_addr)) == 0)
 148       {
 149         *ckey = ckey_cache[i].ckey;
 150         ret = TRUE;
 151         break;
 152       }
 153
 154   if (!ret && key_gendes (ckey) >= 0)
 155     {
 156       ret = TRUE;
 157       /* Don't grow the cache indefinitely.  */
 158       if (ckey_cache_size == 256)
 159         ckey_cache_size = 0;
 160       if (ckey_cache_size == ckey_cache_allocated)
 161         {
 162           size_t size = ckey_cache_allocated ? ckey_cache_allocated * 2 : 16;
 163           struct ckey_cache_entry *new_cache
 164             = realloc (ckey_cache, size * sizeof (*ckey_cache));
 165           if (new_cache != NULL)
 166             {
 167               ckey_cache = new_cache;
 168               ckey_cache_allocated = size;
 169             }
 170         }
 171       ckey_cache[ckey_cache_size].inaddr = addr->sin_addr;
 172       ckey_cache[ckey_cache_size].port = addr->sin_port;
 173       ckey_cache[ckey_cache_size].protocol = protocol;
 174       ckey_cache[ckey_cache_size++].ckey = *ckey;
 175     }
 176
 177   __libc_lock_unlock (ckey_cache_lock);
 178   return ret;
 179 }
 180
 181 nis_error
 182 __nisbind_connect (dir_binding *dbp)
 183 {
 184   nis_server *serv;
 185   u_short port;
 186
 187   if (dbp == NULL)
 188     return NIS_FAIL;
 189
 190   serv = &dbp->server_val[dbp->server_used];
 191
 192   memset (&dbp->addr, '\0', sizeof (dbp->addr));
 193   dbp->addr.sin_family = AF_INET;
 194
 195   dbp->addr.sin_addr.s_addr =
 196     inetstr2int (serv->ep.ep_val[dbp->current_ep].uaddr);
 197
 198   if (dbp->addr.sin_addr.s_addr == INADDR_NONE)
 199     return NIS_FAIL;
 200
 201   /* Check, if the host is online and rpc.nisd is running. Much faster
 202      then the clnt*_create functions: */
 203   port = __pmap_getnisport (&dbp->addr, NIS_PROG, NIS_VERSION,
 204                             dbp->use_udp ? IPPROTO_UDP : IPPROTO_TCP);
 205   if (port == 0)
 206     return NIS_RPCERROR;
 207
 208   dbp->addr.sin_port = htons (port);
 209   dbp->socket = RPC_ANYSOCK;
 210   if (dbp->use_udp)
 211     dbp->clnt = clntudp_create (&dbp->addr, NIS_PROG, NIS_VERSION,
 212                                  UDPTIMEOUT, &dbp->socket);
 213   else
 214     dbp->clnt = clnttcp_create (&dbp->addr, NIS_PROG, NIS_VERSION,
 215                                  &dbp->socket, 0, 0);
 216
 217   if (dbp->clnt == NULL)
 218     return NIS_RPCERROR;
 219
 220   clnt_control (dbp->clnt, CLSET_TIMEOUT, (caddr_t) &RPCTIMEOUT);
 221   /* If the program exists, close the socket */
 222   if (fcntl (dbp->socket, F_SETFD, 1) == -1)
 223     perror ("fcntl: F_SETFD");
 224
 225   if (dbp->use_auth)
 226     {
 227       if (serv->key_type == NIS_PK_DH)
 228         {
 229           char netname[MAXNETNAMELEN + 1];
 230           char *p;
 231           des_block ckey;
 232
 233           p = stpcpy (netname, "unix@");
 234           strncpy (p, serv->name, MAXNETNAMELEN - 5);
 235           netname[MAXNETNAMELEN] = '\0';
 236           dbp->clnt->cl_auth = NULL;
 237           if (get_ckey (&ckey, &dbp->addr,
 238                         dbp->use_udp ? IPPROTO_UDP : IPPROTO_TCP))
 239             dbp->clnt->cl_auth =
 240               authdes_pk_create (netname, &serv->pkey, 300, NULL, &ckey);
 241           if (!dbp->clnt->cl_auth)
 242             dbp->clnt->cl_auth = authunix_create_default ();
 243         }
 244       else
 245         dbp->clnt->cl_auth = authunix_create_default ();
 246     }
 247
 248   return NIS_SUCCESS;
 249 }
 250 libnsl_hidden_def (__nisbind_connect)
 251
 252 nis_error
 253 __nisbind_create (dir_binding *dbp, const nis_server *serv_val,
 254                   unsigned int serv_len, unsigned int server_used,
 255                   unsigned int current_ep, unsigned int flags)
 256 {
 257   dbp->clnt = NULL;
 258
 259   dbp->server_len = serv_len;
 260   dbp->server_val = (nis_server *)serv_val;
 261
 262   if (flags & USE_DGRAM)
 263     dbp->use_udp = TRUE;
 264   else
 265     dbp->use_udp = FALSE;
 266
 267   if (flags & NO_AUTHINFO)
 268     dbp->use_auth = FALSE;
 269   else
 270     dbp->use_auth = TRUE;
 271
 272   if (flags & MASTER_ONLY)
 273     dbp->master_only = TRUE;
 274   else
 275     dbp->master_only = FALSE;
 276
 277   /* We try the first server */
 278   dbp->trys = 1;
 279
 280   dbp->class = -1;
 281   if (server_used == ~0)
 282     {
 283       if (__nis_findfastest (dbp) < 1)
 284         return NIS_NAMEUNREACHABLE;
 285     }
 286   else
 287     {
 288       dbp->server_used = server_used;
 289       dbp->current_ep = current_ep;
 290     }
 291
 292   return NIS_SUCCESS;
 293 }
 294 libnsl_hidden_def (__nisbind_create)
 295
 296 /* __nisbind_connect (dbp) must be run before calling this function !
 297    So we could use the same binding twice */
 298 nis_error
 299 __do_niscall3 (dir_binding *dbp, u_long prog, xdrproc_t xargs, caddr_t req,
 300                xdrproc_t xres, caddr_t resp, unsigned int flags, nis_cb *cb)
 301 {
 302   enum clnt_stat result;
 303   nis_error retcode;
 304
 305   if (dbp == NULL)
 306     return NIS_NAMEUNREACHABLE;
 307
 308   do
 309     {
 310     again:
 311       result = clnt_call (dbp->clnt, prog, xargs, req, xres, resp, RPCTIMEOUT);
 312
 313       if (result != RPC_SUCCESS)
 314         retcode = NIS_RPCERROR;
 315       else
 316         {
 317           switch (prog)
 318             {
 319             case NIS_IBLIST:
 320               if ((((nis_result *)resp)->status == NIS_CBRESULTS) &&
 321                   (cb != NULL))
 322                 {
 323                   __nis_do_callback (dbp, &((nis_result *) resp)->cookie, cb);
 324                   break;
 325                 }
 326               /* Yes, the missing break is correct. If we doesn't have to
 327                  start a callback, look if we have to search another server */
 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_def (__do_niscall3)
 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 timeval *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 timeval *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     for (i = 1; i < 16; ++i)
 685       if (nis_server_cache[i] == NULL)
 686         {
 687           loc = &nis_server_cache[i];
 688           break;
 689         }
 690       else if ((*loc)->uses > nis_server_cache[i]->uses
 691                || ((*loc)->uses == nis_server_cache[i]->uses
 692                    && (*loc)->expires > nis_server_cache[i]->expires))
 693         loc = &nis_server_cache[i];
 694   old = *loc;
 695   *loc = new;
 696
 697   __libc_lock_unlock (nis_server_cache_lock);
 698   free (old);
 699 }
 700
 701 nis_error
 702 __nisfind_server (const_nis_name name, int search_parent,
 703                   directory_obj **dir, dir_binding *dbp, unsigned int flags)
 704 {
 705   nis_error result = NIS_SUCCESS;
 706   nis_error status;
 707   directory_obj *obj;
 708   struct timeval now;
 709   unsigned int server_used = ~0;
 710   unsigned int current_ep = ~0;
 711
 712   if (name == NULL)
 713     return NIS_BADNAME;
 714
 715   if (*dir != NULL)
 716     return NIS_SUCCESS;
 717
 718   (void) gettimeofday (&now, NULL);
 719
 720   if ((flags & NO_CACHE) == 0)
 721     *dir = nis_server_cache_search (name, search_parent, &server_used,
 722                                     &current_ep, &now);
 723   if (*dir != NULL)
 724     {
 725       unsigned int server_len = (*dir)->do_servers.do_servers_len;
 726       if (flags & MASTER_ONLY)
 727         {
 728           server_len = 1;
 729           if (server_used != 0)
 730             {
 731               server_used = ~0;
 732               current_ep = ~0;
 733             }
 734         }
 735       result = __nisbind_create (dbp, (*dir)->do_servers.do_servers_val,
 736                                  server_len, server_used, current_ep, flags);
 737       if (result != NIS_SUCCESS)
 738         {
 739           nis_free_directory (*dir);
 740           *dir = NULL;
 741         }
 742       return result;
 743     }
 744
 745   int saved_errno = errno;
 746   *dir = readColdStartFile ();
 747   __set_errno (saved_errno);
 748   if (*dir == NULL)
 749     /* No /var/nis/NIS_COLD_START->no NIS+ installed.  */
 750     return NIS_UNAVAIL;
 751
 752   /* Try at first, if servers in "dir" know our object */
 753   const char *search_name = name;
 754   if (search_parent)
 755     search_name = __nis_domain_of (name);
 756   obj = first_shoot (search_name, *dir);
 757   if (obj == NULL)
 758     {
 759       obj = rec_dirsearch (search_name, *dir, &status);
 760       if (obj == NULL)
 761         result = status;
 762     }
 763
 764   if (result == NIS_SUCCESS)
 765     {
 766       unsigned int server_len = obj->do_servers.do_servers_len;
 767       if (flags & MASTER_ONLY)
 768         server_len = 1;
 769       result = __nisbind_create (dbp, obj->do_servers.do_servers_val,
 770                                  server_len, ~0, ~0, flags);
 771       if (result == NIS_SUCCESS)
 772         {
 773           if ((flags & MASTER_ONLY) == 0
 774               || obj->do_servers.do_servers_len == 1)
 775             {
 776               server_used = dbp->server_used;
 777               current_ep = dbp->current_ep;
 778             }
 779           if ((flags & NO_CACHE) == 0)
 780             nis_server_cache_add (name, search_parent, obj,
 781                                   server_used, current_ep, &now);
 782         }
 783       else
 784         {
 785           nis_free_directory (obj);
 786           obj = NULL;
 787         }
 788     }
 789
 790   *dir = obj;
 791
 792   return result;
 793 }
 794
 795
 796 nis_error
 797 __prepare_niscall (const_nis_name name, directory_obj **dirp,
 798                    dir_binding *bptrp, unsigned int flags)
 799 {
 800   nis_error retcode = __nisfind_server (name, 1, dirp, bptrp, flags);
 801   if (__builtin_expect (retcode != NIS_SUCCESS, 0))
 802     return retcode;
 803
 804   do
 805     if (__nisbind_connect (bptrp) == NIS_SUCCESS)
 806       return NIS_SUCCESS;
 807   while (__nisbind_next (bptrp) == NIS_SUCCESS);
 808
 809   __nisbind_destroy (bptrp);
 810   memset (bptrp, '\0', sizeof (*bptrp));
 811
 812   retcode = NIS_NAMEUNREACHABLE;
 813   nis_free_directory (*dirp);
 814   *dirp = NULL;
 815
 816   return retcode;
 817 }
 818 libnsl_hidden_def (__prepare_niscall)
 819
 820
 821 nis_error
 822 __do_niscall (const_nis_name name, u_long prog, xdrproc_t xargs,
 823               caddr_t req, xdrproc_t xres, caddr_t resp, unsigned int flags,
 824               nis_cb *cb)
 825 {
 826   dir_binding bptr;
 827   directory_obj *dir = NULL;
 828   int saved_errno = errno;
 829
 830   nis_error retcode = __prepare_niscall (name, &dir, &bptr, flags);
 831   if (retcode == NIS_SUCCESS)
 832     {
 833       retcode = __do_niscall3 (&bptr, prog, xargs, req, xres, resp, flags, cb);
 834
 835       __nisbind_destroy (&bptr);
 836
 837       nis_free_directory (dir);
 838     }
 839
 840   __set_errno (saved_errno);
 841
 842   return retcode;
 843 }