lib/netio.c

   1 /* netio.c      network I/O functions
   2  * Copyright (C) 2002, 2003  Simon Josefsson
   3  *
   4  * This file is part of Shishi.
   5  *
   6  * Shishi is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * Shishi 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
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with Shishi; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  *
  20  */
  21
  22 #include "internal.h"
  23
  24 static int
  25 shishi_sendrecv_udp (Shishi * handle,
  26                      struct sockaddr *addr,
  27                      const char *indata, int inlen,
  28                      char *outdata, int *outlen, int timeout)
  29 {
  30   struct sockaddr lsa;
  31   struct sockaddr_in *lsa_inp = (struct sockaddr_in *) &lsa;
  32   int sockfd;
  33   int bytes_sent;
  34   struct sockaddr_storage from_sa;
  35   int length = sizeof (struct sockaddr_storage);
  36   fd_set readfds;
  37   struct timeval tout;
  38   int rc;
  39
  40   memset (&lsa, 0, sizeof (lsa));
  41   lsa_inp->sin_family = AF_INET;
  42   lsa_inp->sin_addr.s_addr = htonl (INADDR_ANY);
  43
  44   sockfd = socket (AF_INET, SOCK_DGRAM, 0);
  45   if (sockfd < 0)
  46     {
  47       shishi_error_set (handle, strerror (errno));
  48       return SHISHI_SOCKET_ERROR;
  49     }
  50
  51   if (bind (sockfd, (struct sockaddr *) &lsa, sizeof (lsa)) != 0)
  52     {
  53       shishi_error_set (handle, strerror (errno));
  54       close (sockfd);
  55       return SHISHI_BIND_ERROR;
  56     }
  57
  58   bytes_sent = sendto (sockfd, (const void *) indata, inlen,
  59                        0, addr, sizeof (*addr));
  60   if (bytes_sent != inlen)
  61     {
  62       shishi_error_set (handle, strerror (errno));
  63       return SHISHI_SENDTO_ERROR;
  64     }
  65
  66   FD_ZERO (&readfds);
  67   FD_SET (sockfd, &readfds);
  68   tout.tv_sec = timeout;
  69   tout.tv_usec = 0;
  70   if ((rc = select (sockfd + 1, &readfds, NULL, NULL, &tout)) != 1)
  71     {
  72       if (rc == -1)
  73         shishi_error_set (handle, strerror (errno));
  74       else
  75         shishi_error_clear (handle);
  76       return SHISHI_KDC_TIMEOUT;
  77     }
  78
  79   *outlen = recvfrom (sockfd, outdata, *outlen, 0,
  80                       (struct sockaddr *) &from_sa, &length);
  81
  82   if (*outlen == -1)
  83     {
  84       shishi_error_set (handle, strerror (errno));
  85       return SHISHI_RECVFROM_ERROR;
  86     }
  87
  88   if (close (sockfd) != 0)
  89     {
  90       shishi_error_set (handle, strerror (errno));
  91       return SHISHI_CLOSE_ERROR;
  92     }
  93
  94   return SHISHI_OK;
  95 }
  96
  97 static int
  98 shishi_kdc_sendrecv_static (Shishi * handle, char *realm,
  99                             const char *indata, size_t inlen,
 100                             char *outdata, size_t * outlen)
 101 {
 102   int i, j, k;
 103   int rc;
 104
 105   for (i = 0; i < handle->nrealminfos; i++)
 106     if (realm && strcmp (handle->realminfos[i].name, realm) == 0)
 107       {
 108         for (j = 0; j < handle->kdcretries; j++)
 109           for (k = 0; k < handle->realminfos[i].nkdcaddresses; k++)
 110             {
 111               struct Shishi_kdcinfo *ki =
 112                 &handle->realminfos[i].kdcaddresses[k];
 113
 114               if (VERBOSE (handle))
 115                 {
 116                   printf ("Sending to %s (%s)...\n", ki->name,
 117                           inet_ntoa (((struct sockaddr_in *)
 118                                       &ki->sockaddress)->sin_addr));
 119                 }
 120
 121               rc = shishi_sendrecv_udp (handle, &ki->sockaddress,
 122                                         indata, inlen, outdata, outlen,
 123                                         handle->kdctimeout);
 124               if (rc != SHISHI_KDC_TIMEOUT)
 125                 return rc;
 126             }
 127
 128         shishi_error_clear (handle);
 129         return SHISHI_KDC_TIMEOUT;
 130       }
 131
 132   shishi_error_printf (handle, "No KDC defined for realm %s", realm);
 133   return SHISHI_KDC_NOT_KNOWN_FOR_REALM;
 134 }
 135
 136 static int
 137 shishi_kdc_sendrecv_srv_1 (Shishi * handle, char *realm,
 138                            const char *indata, size_t inlen,
 139                            char *outdata, size_t * outlen,
 140                            dnshost_t rrs)
 141 {
 142   int rc;
 143
 144   for (; rrs; rrs = rrs->next)
 145     {
 146       dns_srv_t srv = (dns_srv_t) rrs->rr;
 147       struct addrinfo hints;
 148       struct addrinfo *ai;
 149       char *port;
 150
 151       if (rrs->class != C_IN)
 152         continue;
 153       if (rrs->type != T_SRV)
 154         continue;
 155
 156       if (VERBOSE (handle))
 157         printf ("Located SRV RRs server %s:%d...\n", srv->name, srv->port);
 158
 159       memset (&hints, 0, sizeof(hints));
 160       hints.ai_socktype = SOCK_DGRAM;
 161       asprintf (&port, "%d", srv->port);
 162       rc = getaddrinfo (srv->name, port, &hints, &ai);
 163       free (port);
 164
 165       if (rc != 0)
 166         {
 167           shishi_warn (handle, "Unknown KDC host `%s' (gai rc %d)",
 168                        srv->name, rc);
 169           freeaddrinfo (ai);
 170           continue;
 171         }
 172
 173       if (VERBOSE (handle))
 174         printf ("Sending to %s:%d (%s)...\n", srv->name, srv->port,
 175                 inet_ntoa (((struct sockaddr_in *)ai->ai_addr)->sin_addr));
 176
 177       rc = shishi_sendrecv_udp (handle, ai->ai_addr,
 178                                 indata, inlen, outdata, outlen,
 179                                 handle->kdctimeout);
 180
 181       freeaddrinfo (ai);
 182
 183       if (rc != SHISHI_KDC_TIMEOUT)
 184         return rc;
 185     }
 186
 187   return SHISHI_KDC_TIMEOUT;
 188 }
 189
 190 static int
 191 shishi_kdc_sendrecv_srv (Shishi * handle, char *realm,
 192                          const char *indata, size_t inlen,
 193                          char *outdata, size_t * outlen)
 194 {
 195   dnshost_t rrs;
 196   char *tmp;
 197   int rc;
 198
 199   if (VERBOSE (handle))
 200     printf ("Finding SRV RRs for %s...\n", realm);
 201
 202   asprintf (&tmp, "_kerberos._udp.%s", realm);
 203   rrs = _shishi_resolv(tmp, T_SRV);
 204   free (tmp);
 205
 206   if (rrs)
 207     rc = shishi_kdc_sendrecv_srv_1 (handle, realm, indata, inlen,
 208                                     outdata, outlen, rrs);
 209   else
 210     {
 211       shishi_error_printf (handle, "No KDC SRV RRs for realm %s", realm);
 212       rc = SHISHI_KDC_NOT_KNOWN_FOR_REALM;
 213     }
 214
 215   _shishi_resolv_free (rrs);
 216
 217   return rc;
 218 }
 219
 220 static int
 221 shishi_kdc_sendrecv_direct (Shishi * handle, char *realm,
 222                             const char *indata, size_t inlen,
 223                             char *outdata, size_t * outlen)
 224 {
 225   struct servent *se;
 226   struct addrinfo hints;
 227   struct addrinfo *ai;
 228   char *port;
 229   int rc;
 230
 231   if (VERBOSE (handle))
 232     printf ("Trying direct realm host mapping for %s...\n", realm);
 233
 234   se = getservbyname ("kerberos", NULL);
 235   if (se)
 236     asprintf (&port, "%d", ntohs(se->s_port));
 237   else
 238     asprintf (&port, "%d", 88);
 239
 240   memset (&hints, 0, sizeof(hints));
 241   hints.ai_socktype = SOCK_DGRAM;
 242   rc = getaddrinfo (realm, port, &hints, &ai);
 243
 244   free (port);
 245
 246   if (rc != 0)
 247     {
 248       shishi_error_printf (handle, "No direct realm host for realm %s", realm);
 249       return SHISHI_KDC_NOT_KNOWN_FOR_REALM;
 250     }
 251
 252   if (VERBOSE (handle))
 253     printf ("Sending to %s:%s (%s)...\n", realm, port,
 254             inet_ntoa (((struct sockaddr_in *)ai->ai_addr)->sin_addr));
 255
 256   rc = shishi_sendrecv_udp (handle, ai->ai_addr,
 257                             indata, inlen, outdata, outlen,
 258                             handle->kdctimeout);
 259
 260   freeaddrinfo (ai);
 261
 262   return rc;
 263 }
 264
 265 int
 266 shishi_kdc_sendrecv (Shishi * handle, char *realm,
 267                      const char *indata, size_t inlen,
 268                      char *outdata, size_t * outlen)
 269 {
 270   int rc;
 271
 272   rc = shishi_kdc_sendrecv_static (handle, realm,
 273                                    indata, inlen, outdata, outlen);
 274
 275   if (rc == SHISHI_KDC_TIMEOUT || rc == SHISHI_KDC_NOT_KNOWN_FOR_REALM)
 276     rc = shishi_kdc_sendrecv_srv (handle, realm,
 277                                   indata, inlen, outdata, outlen);
 278   if (rc == SHISHI_KDC_TIMEOUT || rc == SHISHI_KDC_NOT_KNOWN_FOR_REALM)
 279     rc = shishi_kdc_sendrecv_direct (handle, realm,
 280                                      indata, inlen, outdata, outlen);
 281
 282   return rc;
 283 }