nis/nis_callback.c

   1 /* Copyright (C) 1997-2020 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Thorsten Kukuk <kukuk@suse.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, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <unistd.h>
  23 #include <libintl.h>
  24 #include <rpc/rpc.h>
  25 #include <rpc/pmap_clnt.h>
  26 #include <string.h>
  27 #include <memory.h>
  28 #include <syslog.h>
  29 #include <sys/poll.h>
  30 #include <sys/socket.h>
  31 #include <netinet/in.h>
  32 #include <arpa/inet.h>
  33 #include <rpc/key_prot.h>
  34 #include <rpcsvc/nis.h>
  35 #include <rpcsvc/nis_callback.h>
  36 #include <libc-lock.h>
  37
  38 #include "nis_xdr.h"
  39 #include "nis_intern.h"
  40
  41 /* Sorry, we are not able to make this threadsafe. Stupid. But some
  42    functions doesn't send us a nis_result obj, so we don't have a
  43    cookie. Maybe we could use keys for threads ? Have to learn more
  44    about pthreads -- kukuk@vt.uni-paderborn.de */
  45
  46 static nis_cb *data;
  47
  48 __libc_lock_define_initialized (static, callback)
  49
  50
  51 #if 0
  52 static char *
  53 __nis_getpkey(const char *sname)
  54 {
  55   char buf[(strlen (sname) + 1) * 2 + 40];
  56   char pkey[HEXKEYBYTES + 1];
  57   char *cp, *domain;
  58   nis_result *res;
  59   unsigned int len = 0;
  60
  61   domain = strchr (sname, '.');
  62   if (domain == NULL)
  63     return NULL;
  64
  65   /* Remove prefixing dot */
  66   ++domain;
  67
  68   cp = stpcpy (buf, "[cname=");
  69   cp = stpcpy (cp, sname);
  70   cp = stpcpy (cp, ",auth_type=DES],cred.org_dir.");
  71   cp = stpcpy (cp, domain);
  72
  73   res = nis_list (buf, USE_DGRAM|NO_AUTHINFO|FOLLOW_LINKS|FOLLOW_PATH,
  74                   NULL, NULL);
  75
  76   if (res == NULL)
  77     return NULL;
  78
  79   if (NIS_RES_STATUS (res) != NIS_SUCCESS)
  80     {
  81       nis_freeresult (res);
  82       return NULL;
  83     }
  84
  85   len = ENTRY_LEN(NIS_RES_OBJECT(res), 3);
  86   strncpy (pkey, ENTRY_VAL(NIS_RES_OBJECT(res), 3), len);
  87   pkey[len] = '\0';
  88   cp = strchr (pkey, ':');
  89   if (cp != NULL)
  90     *cp = '\0';
  91
  92   nis_freeresult (res);
  93
  94   return strdup (pkey);
  95 }
  96 #endif
  97
  98 static void
  99 cb_prog_1 (struct svc_req *rqstp, SVCXPRT *transp)
 100 {
 101   union
 102     {
 103       cback_data cbproc_receive_1_arg;
 104       nis_error cbproc_error_1_arg;
 105     }
 106   argument;
 107   char *result;
 108   xdrproc_t xdr_argument, xdr_result;
 109   bool_t bool_result;
 110
 111   switch (rqstp->rq_proc)
 112     {
 113     case NULLPROC:
 114       svc_sendreply (transp, (xdrproc_t) xdr_void, (char *) NULL);
 115       return;
 116
 117     case CBPROC_RECEIVE:
 118       {
 119         unsigned int i;
 120
 121         xdr_argument = (xdrproc_t) xdr_cback_data;
 122         xdr_result = (xdrproc_t) xdr_bool;
 123         memset (&argument, 0, sizeof (argument));
 124         if (!svc_getargs (transp, xdr_argument, (caddr_t) & argument))
 125           {
 126             svcerr_decode (transp);
 127             return;
 128           }
 129         bool_result = FALSE;
 130         for (i = 0; i < argument.cbproc_receive_1_arg.entries.entries_len; ++i)
 131           {
 132 #define cbproc_entry(a) argument.cbproc_receive_1_arg.entries.entries_val[a]
 133             char name[strlen (cbproc_entry(i)->zo_name)
 134                       + strlen (cbproc_entry(i)->zo_domain) + 3];
 135             char *cp;
 136
 137             cp = stpcpy (name, cbproc_entry(i)->zo_name);
 138             *cp++ = '.';
 139             cp = stpcpy (cp, cbproc_entry(i)->zo_domain);
 140
 141             if ((data->callback) (name, cbproc_entry(i), data->userdata))
 142               {
 143                 bool_result = TRUE;
 144                 data->nomore = 1;
 145                 data->result = NIS_SUCCESS;
 146                 break;
 147               }
 148           }
 149         result = (char *) &bool_result;
 150       }
 151       break;
 152     case CBPROC_FINISH:
 153       xdr_argument = (xdrproc_t) xdr_void;
 154       xdr_result = (xdrproc_t) xdr_void;
 155       memset (&argument, 0, sizeof (argument));
 156       if (!svc_getargs (transp, xdr_argument, (caddr_t) & argument))
 157         {
 158           svcerr_decode (transp);
 159           return;
 160         }
 161       data->nomore = 1;
 162       data->result = NIS_SUCCESS;
 163       bool_result = TRUE;       /* to make gcc happy, not necessary */
 164       result = (char *) &bool_result;
 165       break;
 166     case CBPROC_ERROR:
 167       xdr_argument = (xdrproc_t) _xdr_nis_error;
 168       xdr_result = (xdrproc_t) xdr_void;
 169       memset (&argument, 0, sizeof (argument));
 170       if (!svc_getargs (transp, xdr_argument, (caddr_t) & argument))
 171         {
 172           svcerr_decode (transp);
 173           return;
 174         }
 175       data->nomore = 1;
 176       data->result = argument.cbproc_error_1_arg;
 177       bool_result = TRUE;       /* to make gcc happy, not necessary */
 178       result = (char *) &bool_result;
 179       break;
 180     default:
 181       svcerr_noproc (transp);
 182       return;
 183     }
 184   if (result != NULL && !svc_sendreply (transp, xdr_result, result))
 185     svcerr_systemerr (transp);
 186   if (!svc_freeargs (transp, xdr_argument, (caddr_t) & argument))
 187     {
 188       fputs (_ ("unable to free arguments"), stderr);
 189       exit (1);
 190     }
 191   return;
 192 }
 193
 194 static nis_error
 195 internal_nis_do_callback (struct dir_binding *bptr, netobj *cookie,
 196                           struct nis_cb *cb)
 197 {
 198   struct timeval TIMEOUT = {25, 0};
 199   bool_t cb_is_running;
 200
 201   data = cb;
 202
 203   for (;;)
 204     {
 205       struct pollfd my_pollfd[svc_max_pollfd];
 206       int i;
 207
 208       if (svc_max_pollfd == 0 && svc_pollfd == NULL)
 209         return NIS_CBERROR;
 210
 211       for (i = 0; i < svc_max_pollfd; ++i)
 212         {
 213           my_pollfd[i].fd = svc_pollfd[i].fd;
 214           my_pollfd[i].events = svc_pollfd[i].events;
 215           my_pollfd[i].revents = 0;
 216         }
 217
 218       switch (i = TEMP_FAILURE_RETRY (__poll (my_pollfd, svc_max_pollfd,
 219                                               25*1000)))
 220         {
 221         case -1:
 222           return NIS_CBERROR;
 223         case 0:
 224           /* See if callback 'thread' in the server is still alive. */
 225           cb_is_running = FALSE;
 226           if (clnt_call (bptr->clnt, NIS_CALLBACK, (xdrproc_t) xdr_netobj,
 227                          (caddr_t) cookie, (xdrproc_t) xdr_bool,
 228                          (caddr_t) &cb_is_running, TIMEOUT) != RPC_SUCCESS)
 229             cb_is_running = FALSE;
 230
 231           if (cb_is_running == FALSE)
 232             {
 233               syslog (LOG_ERR, "NIS+: callback timed out");
 234               return NIS_CBERROR;
 235             }
 236           break;
 237         default:
 238           svc_getreq_poll (my_pollfd, i);
 239           if (data->nomore)
 240             return data->result;
 241         }
 242     }
 243 }
 244
 245 nis_error
 246 __nis_do_callback (struct dir_binding *bptr, netobj *cookie,
 247                    struct nis_cb *cb)
 248 {
 249   nis_error result;
 250
 251   __libc_lock_lock (callback);
 252
 253   result = internal_nis_do_callback (bptr, cookie, cb);
 254
 255   __libc_lock_unlock (callback);
 256
 257   return result;
 258 }
 259
 260 struct nis_cb *
 261 __nis_create_callback (int (*callback) (const_nis_name, const nis_object *,
 262                                         const void *),
 263                        const void *userdata, unsigned int flags)
 264 {
 265   struct nis_cb *cb;
 266   int sock = RPC_ANYSOCK;
 267   struct sockaddr_in sin;
 268   socklen_t len = sizeof (struct sockaddr_in);
 269   unsigned short port;
 270   int nomsg = 0;
 271
 272   cb = (struct nis_cb *) calloc (1,
 273                                  sizeof (struct nis_cb) + sizeof (nis_server));
 274   if (__glibc_unlikely (cb == NULL))
 275     goto failed;
 276   cb->serv = (nis_server *) (cb + 1);
 277   cb->serv->name = strdup (nis_local_principal ());
 278   if (__glibc_unlikely (cb->serv->name == NULL))
 279     goto failed;
 280   cb->serv->ep.ep_val = (endpoint *) calloc (2, sizeof (endpoint));
 281   if (__glibc_unlikely (cb->serv->ep.ep_val == NULL))
 282     goto failed;
 283   cb->serv->ep.ep_len = 1;
 284   cb->serv->ep.ep_val[0].family = strdup ("inet");
 285   if (__glibc_unlikely (cb->serv->ep.ep_val[0].family == NULL))
 286     goto failed;
 287   cb->callback = callback;
 288   cb->userdata = userdata;
 289
 290   if ((flags & NO_AUTHINFO) || !key_secretkey_is_set ())
 291     {
 292       cb->serv->key_type = NIS_PK_NONE;
 293       cb->serv->pkey.n_bytes = NULL;
 294       cb->serv->pkey.n_len = 0;
 295     }
 296   else
 297     {
 298 #if 0
 299       if ((cb->serv->pkey.n_bytes = __nis_getpkey (cb->serv->name)) == NULL)
 300         {
 301           cb->serv->pkey.n_len = 0;
 302           cb->serv->key_type = NIS_PK_NONE;
 303         }
 304       else
 305         {
 306           cb->serv->key_type = NIS_PK_DH;
 307           cb->serv->pkey.n_len = strlen(cb->serv->pkey.n_bytes);
 308         }
 309 #else
 310       cb->serv->pkey.n_len =0;
 311       cb->serv->pkey.n_bytes = NULL;
 312       cb->serv->key_type = NIS_PK_NONE;
 313 #endif
 314     }
 315
 316   cb->serv->ep.ep_val[0].proto = strdup ((flags & USE_DGRAM) ? "udp" : "tcp");
 317   if (__glibc_unlikely (cb->serv->ep.ep_val[0].proto == NULL))
 318     goto failed;
 319   cb->xprt = ((flags & USE_DGRAM)
 320               ? svcudp_bufcreate (sock, 100, 8192)
 321               : svctcp_create (sock, 100, 8192));
 322   if (cb->xprt == NULL)
 323     {
 324       nomsg = 1;
 325       goto failed;
 326     }
 327   cb->sock = cb->xprt->xp_sock;
 328   if (!svc_register (cb->xprt, CB_PROG, CB_VERS, cb_prog_1, 0))
 329     {
 330       xprt_unregister (cb->xprt);
 331       svc_destroy (cb->xprt);
 332       xdr_free ((xdrproc_t) _xdr_nis_server, (char *) cb->serv);
 333       free (cb);
 334       syslog (LOG_ERR, "NIS+: failed to register callback dispatcher");
 335       return NULL;
 336     }
 337
 338   if (getsockname (cb->sock, (struct sockaddr *) &sin, &len) == -1)
 339     {
 340       xprt_unregister (cb->xprt);
 341       svc_destroy (cb->xprt);
 342       xdr_free ((xdrproc_t) _xdr_nis_server, (char *) cb->serv);
 343       free (cb);
 344       syslog (LOG_ERR, "NIS+: failed to read local socket info");
 345       return NULL;
 346     }
 347   port = ntohs (sin.sin_port);
 348   get_myaddress (&sin);
 349
 350   if (asprintf (&cb->serv->ep.ep_val[0].uaddr, "%s.%d.%d",
 351                 inet_ntoa (sin.sin_addr), (port & 0xFF00) >> 8, port & 0x00FF)
 352       < 0)
 353     goto failed;
 354
 355   return cb;
 356
 357  failed:
 358   if (cb)
 359     {
 360       if (cb->xprt)
 361         svc_destroy (cb->xprt);
 362       xdr_free ((xdrproc_t) _xdr_nis_server, (char *) cb->serv);
 363       free (cb);
 364     }
 365   if (!nomsg)
 366     syslog (LOG_ERR, "NIS+: out of memory allocating callback");
 367   return NULL;
 368 }
 369
 370 nis_error
 371 __nis_destroy_callback (struct nis_cb *cb)
 372 {
 373   xprt_unregister (cb->xprt);
 374   svc_destroy (cb->xprt);
 375   close (cb->sock);
 376   xdr_free ((xdrproc_t) _xdr_nis_server, (char *) cb->serv);
 377   free (cb);
 378
 379   return NIS_SUCCESS;
 380 }