nis/nis_findserv.c

   1 /* Copyright (C) 1997, 1998, 2000, 2001 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, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <string.h>
  21 #include <time.h>
  22 #include <unistd.h>
  23 #include <sys/ioctl.h>
  24 #include <sys/socket.h>
  25 #include <rpc/pmap_prot.h>
  26 #include <rpc/pmap_clnt.h>
  27 #include <rpcsvc/nis.h>
  28
  29 #include "nis_intern.h"
  30
  31 /* Private data kept per client handle, from sunrpc/clnt_udp.c */
  32 struct cu_data
  33   {
  34     int cu_sock;
  35     bool_t cu_closeit;
  36     struct sockaddr_in cu_raddr;
  37     int cu_rlen;
  38     struct timeval cu_wait;
  39     struct timeval cu_total;
  40     struct rpc_err cu_error;
  41     XDR cu_outxdrs;
  42     u_int cu_xdrpos;
  43     u_int cu_sendsz;
  44     char *cu_outbuf;
  45     u_int cu_recvsz;
  46     char cu_inbuf[1];
  47   };
  48
  49
  50 /* The following is the original routine from sunrpc/pm_getport.c.
  51    The only change is the much shorter timeout. */
  52 /*
  53  * pmap_getport.c
  54  * Client interface to pmap rpc service.
  55  *
  56  * Copyright (C) 1984, Sun Microsystems, Inc.
  57  */
  58
  59 /*
  60  * Find the mapped port for program,version.
  61  * Calls the pmap service remotely to do the lookup.
  62  * Returns 0 if no map exists.
  63  */
  64 u_short
  65 __pmap_getnisport (struct sockaddr_in *address, u_long program,
  66                    u_long version, u_int protocol)
  67 {
  68   const struct timeval timeout = {1, 0};
  69   const struct timeval tottimeout = {1, 0};
  70   u_short port = 0;
  71   int socket = -1;
  72   CLIENT *client;
  73   struct pmap parms;
  74
  75   address->sin_port = htons (PMAPPORT);
  76   client = clntudp_bufcreate (address, PMAPPROG, PMAPVERS, timeout, &socket,
  77                               RPCSMALLMSGSIZE, RPCSMALLMSGSIZE);
  78   if (client != (CLIENT *) NULL)
  79     {
  80       parms.pm_prog = program;
  81       parms.pm_vers = version;
  82       parms.pm_prot = protocol;
  83       parms.pm_port = 0;        /* not needed or used */
  84       if (CLNT_CALL (client, PMAPPROC_GETPORT, (xdrproc_t) xdr_pmap,
  85                      (caddr_t) & parms, (xdrproc_t) xdr_u_short,
  86                      (caddr_t) & port, tottimeout) != RPC_SUCCESS)
  87         {
  88           rpc_createerr.cf_stat = RPC_PMAPFAILURE;
  89           clnt_geterr (client, &rpc_createerr.cf_error);
  90         }
  91       else
  92         {
  93           if (port == 0)
  94             rpc_createerr.cf_stat = RPC_PROGNOTREGISTERED;
  95         }
  96       CLNT_DESTROY (client);
  97     }
  98   /* (void)close(socket); CLNT_DESTROY already closed it */
  99   address->sin_port = 0;
 100   return port;
 101 }
 102
 103 /* This is now the public function, which should find the fastest server */
 104
 105 struct findserv_req
 106 {
 107   struct sockaddr_in sin;
 108   u_int32_t xid;
 109   u_int server_nr;
 110   u_int server_ep;
 111 };
 112
 113
 114 static long int
 115 __nis_findfastest_with_timeout (dir_binding *bind,
 116                                 const struct timeval *timeout)
 117 {
 118   static const struct timeval TIMEOUT00 = { 0, 0 };
 119   struct findserv_req *pings;
 120   struct sockaddr_in sin, saved_sin;
 121   int found = -1;
 122   u_int32_t xid_seed;
 123   int sock, dontblock = 1;
 124   CLIENT *clnt;
 125   u_long i, j, pings_count, pings_max, fastest = -1;
 126   struct cu_data *cu;
 127
 128   pings_max = bind->server_len * 2;     /* Reserve a little bit more memory
 129                                            for multihomed hosts */
 130   pings_count = 0;
 131   pings = malloc (sizeof (struct findserv_req) * pings_max);
 132   xid_seed = (u_int32_t) (time (NULL) ^ getpid ());
 133
 134   if (__builtin_expect (pings == NULL, 0))
 135     return -1;
 136
 137   memset (&sin, '\0', sizeof (sin));
 138   sin.sin_family = AF_INET;
 139   for (i = 0; i < bind->server_len; i++)
 140     for (j = 0; j < bind->server_val[i].ep.ep_len; ++j)
 141       if (strcmp (bind->server_val[i].ep.ep_val[j].family, "inet") == 0)
 142         if ((bind->server_val[i].ep.ep_val[j].proto == NULL) ||
 143             (bind->server_val[i].ep.ep_val[j].proto[0] == '-') ||
 144             (bind->server_val[i].ep.ep_val[j].proto[0] == '\0'))
 145           {
 146             sin.sin_addr.s_addr =
 147               inetstr2int (bind->server_val[i].ep.ep_val[j].uaddr);
 148             if (sin.sin_addr.s_addr == 0)
 149               continue;
 150             sin.sin_port = htons (__pmap_getnisport (&sin, NIS_PROG,
 151                                                      NIS_VERSION,
 152                                                      IPPROTO_UDP));
 153             if (sin.sin_port == 0)
 154               continue;
 155
 156             if (pings_count >= pings_max)
 157               {
 158                 struct findserv_req *new_pings;
 159
 160                 pings_max += 10;
 161                 new_pings = realloc (pings, sizeof (struct findserv_req) *
 162                                      pings_max);
 163                 if (__builtin_expect (new_pings == NULL, 0))
 164                   {
 165                     free (pings);
 166                     return -1;
 167                   }
 168                 pings = new_pings;
 169               }
 170             memcpy ((char *) &pings[pings_count].sin, (char *) &sin,
 171                     sizeof (sin));
 172             memcpy ((char *)&saved_sin, (char *)&sin, sizeof(sin));
 173             pings[pings_count].xid = xid_seed + pings_count;
 174             pings[pings_count].server_nr = i;
 175             pings[pings_count].server_ep = j;
 176             ++pings_count;
 177           }
 178
 179   /* Make sure at least one server was assigned */
 180   if (pings_count == 0)
 181     {
 182       free (pings);
 183       return -1;
 184     }
 185
 186   /* Create RPC handle */
 187   sock = socket (AF_INET, SOCK_DGRAM, IPPROTO_UDP);
 188   clnt = clntudp_create (&saved_sin, NIS_PROG, NIS_VERSION, *timeout, &sock);
 189   if (clnt == NULL)
 190     {
 191       close (sock);
 192       free (pings);
 193       return -1;
 194     }
 195   auth_destroy (clnt->cl_auth);
 196   clnt->cl_auth = authunix_create_default ();
 197   cu = (struct cu_data *) clnt->cl_private;
 198   ioctl (sock, FIONBIO, &dontblock);
 199   /* Send to all servers the NULLPROC */
 200   for (i = 0; i < pings_count; ++i)
 201     {
 202       /* clntudp_call() will increment, subtract one */
 203       *((u_int32_t *) (cu->cu_outbuf)) = pings[i].xid - 1;
 204       memcpy ((char *) &cu->cu_raddr, (char *) &pings[i].sin,
 205               sizeof (struct sockaddr_in));
 206       /* Transmit to NULLPROC, return immediately. */
 207       clnt_call (clnt, NULLPROC,
 208                  (xdrproc_t) xdr_void, (caddr_t) 0,
 209                  (xdrproc_t) xdr_void, (caddr_t) 0, TIMEOUT00);
 210     }
 211
 212   while (found == -1) {
 213     /* Receive reply from NULLPROC asynchronously. Note null inproc. */
 214     int rc = clnt_call (clnt, NULLPROC,
 215                         (xdrproc_t) NULL, (caddr_t) 0,
 216                         (xdrproc_t) xdr_void, (caddr_t) 0,
 217                         *timeout);
 218     if (RPC_SUCCESS == rc) {
 219       fastest = *((u_int32_t *) (cu->cu_inbuf)) - xid_seed;
 220       if (fastest < pings_count) {
 221         bind->server_used = pings[fastest].server_nr;
 222         bind->current_ep = pings[fastest].server_ep;
 223         found = 1;
 224       }
 225     } else {
 226       /*      clnt_perror(clnt, "__nis_findfastest"); */
 227       break;
 228     }
 229   }
 230
 231
 232   auth_destroy (clnt->cl_auth);
 233   clnt_destroy (clnt);
 234   close (sock);
 235
 236   free (pings);
 237
 238   return found;
 239 }
 240
 241
 242 long int
 243 __nis_findfastest (dir_binding *bind)
 244 {
 245   struct timeval timeout = { __NIS_PING_TIMEOUT_START, 0 };
 246   long int found = -1;
 247   long int retry = __NIS_PING_RETRY + 1;
 248
 249   while (retry--)
 250     {
 251       found = __nis_findfastest_with_timeout (bind, &timeout);
 252       if (found != -1)
 253         break;
 254       timeout.tv_sec += __NIS_PING_TIMEOUT_INCREMENT;
 255     }
 256
 257   return found;
 258 }