nis/nis_findserv.c

   1 /* Copyright (C) 1997, 1998 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 Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    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    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #include <string.h>
  21 #include <unistd.h>
  22 #include <sys/ioctl.h>
  23 #include <sys/socket.h>
  24 #include <rpc/pmap_prot.h>
  25 #include <rpc/pmap_clnt.h>
  26 #include <rpcsvc/nis.h>
  27
  28 #include "nis_intern.h"
  29
  30 /* Private data kept per client handle, from sunrpc/clnt_udp.c */
  31 struct cu_data
  32   {
  33     int cu_sock;
  34     bool_t cu_closeit;
  35     struct sockaddr_in cu_raddr;
  36     int cu_rlen;
  37     struct timeval cu_wait;
  38     struct timeval cu_total;
  39     struct rpc_err cu_error;
  40     XDR cu_outxdrs;
  41     u_int cu_xdrpos;
  42     u_int cu_sendsz;
  43     char *cu_outbuf;
  44     u_int cu_recvsz;
  45     char cu_inbuf[1];
  46   };
  47
  48
  49 /* The following is the original routine from sunrpc/pm_getport.c.
  50    The only change is the much shorter timeout. */
  51 /*
  52  * pmap_getport.c
  53  * Client interface to pmap rpc service.
  54  *
  55  * Copyright (C) 1984, Sun Microsystems, Inc.
  56  */
  57
  58 /*
  59  * Find the mapped port for program,version.
  60  * Calls the pmap service remotely to do the lookup.
  61  * Returns 0 if no map exists.
  62  */
  63 static u_short
  64 __pmap_getport (struct sockaddr_in *address, u_long program,
  65                 u_long version, u_int protocol)
  66 {
  67   const struct timeval timeout = {1, 0};
  68   const struct timeval tottimeout = {1, 0};
  69   u_short port = 0;
  70   int socket = -1;
  71   CLIENT *client;
  72   struct pmap parms;
  73
  74   address->sin_port = htons (PMAPPORT);
  75   client = clntudp_bufcreate (address, PMAPPROG, PMAPVERS, timeout, &socket,
  76                               RPCSMALLMSGSIZE, RPCSMALLMSGSIZE);
  77   if (client != (CLIENT *) NULL)
  78     {
  79       parms.pm_prog = program;
  80       parms.pm_vers = version;
  81       parms.pm_prot = protocol;
  82       parms.pm_port = 0;        /* not needed or used */
  83       if (CLNT_CALL (client, PMAPPROC_GETPORT, (xdrproc_t) xdr_pmap,
  84                      (caddr_t) & parms, (xdrproc_t) xdr_u_short,
  85                      (caddr_t) & port, tottimeout) != RPC_SUCCESS)
  86         {
  87           rpc_createerr.cf_stat = RPC_PMAPFAILURE;
  88           clnt_geterr (client, &rpc_createerr.cf_error);
  89         }
  90       else
  91         {
  92           if (port == 0)
  93             rpc_createerr.cf_stat = RPC_PROGNOTREGISTERED;
  94         }
  95       CLNT_DESTROY (client);
  96     }
  97   /* (void)close(socket); CLNT_DESTROY already closed it */
  98   address->sin_port = 0;
  99   return port;
 100 }
 101
 102 /* This is now the public function, which should find the fastest server */
 103
 104 struct findserv_req
 105 {
 106   struct sockaddr_in sin;
 107   u_int32_t xid;
 108   u_int server_nr;
 109   u_int server_ep;
 110 };
 111
 112 long
 113 __nis_findfastest (dir_binding * bind)
 114 {
 115   const struct timeval TIMEOUT50 = {5, 0};
 116   const struct timeval TIMEOUT00 = {0, 0};
 117   struct findserv_req **pings;
 118   struct sockaddr_in sin, saved_sin;
 119   int found = -1;
 120   u_int32_t xid_seed, xid_lookup;
 121   int sock, dontblock = 1;
 122   CLIENT *clnt;
 123   char clnt_res;
 124   void *foo = NULL;
 125   u_long i, j, pings_count, pings_max;
 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   memset (&sin, '\0', sizeof (sin));
 135   sin.sin_family = AF_INET;
 136   for (i = 0; i < bind->server_len; i++)
 137     for (j = 0; j < bind->server_val[i].ep.ep_len; ++j)
 138       if (strcmp (bind->server_val[i].ep.ep_val[j].family, "inet") == 0)
 139         if ((bind->server_val[i].ep.ep_val[j].proto == NULL) ||
 140             (strcmp (bind->server_val[i].ep.ep_val[j].proto, "-") == 0) ||
 141             (strlen (bind->server_val[i].ep.ep_val[j].proto) == 0))
 142           {
 143             sin.sin_addr.s_addr =
 144               inetstr2int (bind->server_val[i].ep.ep_val[j].uaddr);
 145             if (sin.sin_addr.s_addr == 0)
 146               continue;
 147             sin.sin_port = htons (__pmap_getport (&sin, NIS_PROG,
 148                                                   NIS_VERSION, IPPROTO_UDP));
 149             if (sin.sin_port == 0)
 150               continue;
 151
 152             if (pings_count >= pings_max)
 153               {
 154                 pings_max += 10;
 155                 pings = realloc (pings, sizeof (struct findserv_req) *
 156                                  pings_max);
 157               }
 158             pings[pings_count] = calloc (1, sizeof (struct findserv_req));
 159             memcpy ((char *) &pings[pings_count]->sin, (char *) &sin,
 160                     sizeof (sin));
 161             memcpy ((char *)&saved_sin, (char *)&sin, sizeof(sin));
 162             pings[pings_count]->xid = xid_seed;
 163             pings[pings_count]->server_nr = i;
 164             pings[pings_count]->server_ep = j;
 165             ++xid_seed;
 166             ++pings_count;
 167           }
 168
 169   /* Make sure at least one server was assigned */
 170   if (pings_count == 0)
 171     {
 172       free (pings);
 173       return -1;
 174     }
 175
 176   /* Create RPC handle */
 177   sock = socket (AF_INET, SOCK_DGRAM, IPPROTO_UDP);
 178   clnt = clntudp_create (&saved_sin, NIS_PROG, NIS_VERSION, TIMEOUT50, &sock);
 179   if (clnt == NULL)
 180     {
 181       close (sock);
 182       for (i = 0; i < pings_count; ++i)
 183         free (pings[i]);
 184       free (pings);
 185       return -1;
 186     }
 187   clnt->cl_auth = authunix_create_default ();
 188   cu = (struct cu_data *) clnt->cl_private;
 189   clnt_control (clnt, CLSET_TIMEOUT, (char *) &TIMEOUT00);
 190   ioctl (sock, FIONBIO, &dontblock);
 191
 192   /* Send to all servers the NULLPROC */
 193   for (i = 0; i < pings_count; ++i)
 194     {
 195       /* clntudp_call() will increment, subtract one */
 196       *((u_int32_t *) (cu->cu_outbuf)) = pings[i]->xid - 1;
 197       memcpy ((char *) &cu->cu_raddr, (char *) &pings[i]->sin,
 198               sizeof (struct sockaddr_in));
 199       /* Transmit to NULLPROC, return immediately. */
 200       clnt_call (clnt, NULLPROC, (xdrproc_t) xdr_void, (caddr_t) foo,
 201                  (xdrproc_t) xdr_void, (caddr_t) & clnt_res, TIMEOUT00);
 202     }
 203
 204   /* Receive reply from NULLPROC asynchronously */
 205   memset ((char *) &clnt_res, 0, sizeof (clnt_res));
 206   clnt_call (clnt, NULLPROC, (xdrproc_t) NULL, (caddr_t) foo,
 207              (xdrproc_t) xdr_void, (caddr_t) &clnt_res, TIMEOUT00);
 208
 209   xid_lookup = *((u_int32_t *) (cu->cu_inbuf));
 210   for (i = 0; i < pings_count; i++)
 211     {
 212       if (pings[i]->xid == xid_lookup)
 213         {
 214           bind->server_used = pings[i]->server_nr;
 215           bind->current_ep = pings[i]->server_ep;
 216           found = 1;
 217         }
 218     }
 219
 220   auth_destroy (clnt->cl_auth);
 221   clnt_destroy (clnt);
 222   close (sock);
 223
 224   for (i = 0; i < pings_count; ++i)
 225     free (pings[i]);
 226   free (pings);
 227
 228   return found;
 229 }