nis/nis_callback.c

   1 /* Copyright (C) 1997-2022 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <unistd.h>
  22 #include <libintl.h>
  23 #include <rpc/rpc.h>
  24 #include <rpc/pmap_clnt.h>
  25 #include <string.h>
  26 #include <memory.h>
  27 #include <syslog.h>
  28 #include <sys/poll.h>
  29 #include <sys/socket.h>
  30 #include <netinet/in.h>
  31 #include <arpa/inet.h>
  32 #include <rpc/key_prot.h>
  33 #include <rpcsvc/nis.h>
  34 #include <rpcsvc/nis_callback.h>
  35 #include <libc-lock.h>
  36
  37 #include "nis_xdr.h"
  38 #include "nis_intern.h"
  39
  40 /* Sorry, we are not able to make this threadsafe. Stupid. But some
  41    functions doesn't send us a nis_result obj, so we don't have a
  42    cookie. Maybe we could use keys for threads ? Have to learn more
  43    about pthreads -- kukuk@vt.uni-paderborn.de */
  44
  45 static nis_cb *data;
  46
  47 __libc_lock_define_initialized (static, callback)
  48
  49
  50 #if 0
  51 static char *
  52 __nis_getpkey(const char *sname)
  53 {
  54   char buf[(strlen (sname) + 1) * 2 + 40];
  55   char pkey[HEXKEYBYTES + 1];
  56   char *cp, *domain;
  57   nis_result *res;
  58   unsigned int len = 0;
  59
  60   domain = strchr (sname, '.');
  61   if (domain == NULL)
  62     return NULL;
  63
  64   /* Remove prefixing dot */
  65   ++domain;
  66
  67   cp = stpcpy (buf, "[cname=");
  68   cp = stpcpy (cp, sname);
  69   cp = stpcpy (cp, ",auth_type=DES],cred.org_dir.");
  70   cp = stpcpy (cp, domain);
  71
  72   res = nis_list (buf, USE_DGRAM|NO_AUTHINFO|FOLLOW_LINKS|FOLLOW_PATH,
  73                   NULL, NULL);
  74
  75   if (res == NULL)
  76     return NULL;
  77
  78   if (NIS_RES_STATUS (res) != NIS_SUCCESS)
  79     {
  80       nis_freeresult (res);
  81       return NULL;
  82     }
  83
  84   len = ENTRY_LEN(NIS_RES_OBJECT(res), 3);
  85   strncpy (pkey, ENTRY_VAL(NIS_RES_OBJECT(res), 3), len);
  86   pkey[len] = '\0';
  87   cp = strchr (pkey, ':');
  88   if (cp != NULL)
  89     *cp = '\0';
  90
  91   nis_freeresult (res);
  92
  93   return strdup (pkey);
  94 }
  95 #endif
  96
  97 static void
  98 cb_prog_1 (struct svc_req *rqstp, SVCXPRT *transp)
  99 {
 100   union
 101     {
 102       cback_data cbproc_receive_1_arg;
 103       nis_error cbproc_error_1_arg;
 104     }
 105   argument;
 106   char *result;
 107   xdrproc_t xdr_argument, xdr_result;
 108   bool_t bool_result;
 109
 110   switch (rqstp->rq_proc)
 111     {
 112     case NULLPROC:
 113       svc_sendreply (transp, (xdrproc_t) xdr_void, (char *) NULL);
 114       return;
 115
 116     case CBPROC_RECEIVE:
 117       {
 118         unsigned int i;
 119
 120         xdr_argument = (xdrproc_t) xdr_cback_data;
 121         xdr_result = (xdrproc_t) xdr_bool;
 122         memset (&argument, 0, sizeof (argument));
 123         if (!svc_getargs (transp, xdr_argument, (caddr_t) & argument))
 124           {
 125             svcerr_decode (transp);
 126             return;
 127           }
 128         bool_result = FALSE;
 129         for (i = 0; i < argument.cbproc_receive_1_arg.entries.entries_len; ++i)
 130           {
 131 #define cbproc_entry(a) argument.cbproc_receive_1_arg.entries.entries_val[a]
 132             char name[strlen (cbproc_entry(i)->zo_name)
 133                       + strlen (cbproc_entry(i)->zo_domain) + 3];
 134             char *cp;
 135
 136             cp = stpcpy (name, cbproc_entry(i)->zo_name);
 137             *cp++ = '.';
 138             cp = stpcpy (cp, cbproc_entry(i)->zo_domain);
 139
 140             if ((data->callback) (name, cbproc_entry(i), data->userdata))
 141               {
 142                 bool_result = TRUE;
 143                 data->nomore = 1;
 144                 data->result = NIS_SUCCESS;
 145                 break;
 146               }
 147           }
 148         result = (char *) &bool_result;
 149       }
 150       break;
 151     case CBPROC_FINISH:
 152       xdr_argument = (xdrproc_t) xdr_void;
 153       xdr_result = (xdrproc_t) xdr_void;
 154       memset (&argument, 0, sizeof (argument));
 155       if (!svc_getargs (transp, xdr_argument, (caddr_t) & argument))
 156         {
 157           svcerr_decode (transp);
 158           return;
 159         }
 160       data->nomore = 1;
 161       data->result = NIS_SUCCESS;
 162       bool_result = TRUE;       /* to make gcc happy, not necessary */
 163       result = (char *) &bool_result;
 164       break;
 165     case CBPROC_ERROR:
 166       xdr_argument = (xdrproc_t) _xdr_nis_error;
 167       xdr_result = (xdrproc_t) xdr_void;
 168       memset (&argument, 0, sizeof (argument));
 169       if (!svc_getargs (transp, xdr_argument, (caddr_t) & argument))
 170         {
 171           svcerr_decode (transp);
 172           return;
 173         }
 174       data->nomore = 1;
 175       data->result = argument.cbproc_error_1_arg;
 176       bool_result = TRUE;       /* to make gcc happy, not necessary */
 177       result = (char *) &bool_result;
 178       break;
 179     default:
 180       svcerr_noproc (transp);
 181       return;
 182     }
 183   if (result != NULL && !svc_sendreply (transp, xdr_result, result))
 184     svcerr_systemerr (transp);
 185   if (!svc_freeargs (transp, xdr_argument, (caddr_t) & argument))
 186     {
 187       fputs (_ ("unable to free arguments"), stderr);
 188       exit (1);
 189     }
 190   return;
 191 }
 192
 193 static nis_error
 194 internal_nis_do_callback (struct dir_binding *bptr, netobj *cookie,
 195                           struct nis_cb *cb)
 196 {
 197   struct timeval TIMEOUT = {25, 0};
 198   bool_t cb_is_running;
 199
 200   data = cb;
 201
 202   for (;;)
 203     {
 204       struct pollfd my_pollfd[svc_max_pollfd];
 205       int i;
 206
 207       if (svc_max_pollfd == 0 && svc_pollfd == NULL)
 208         return NIS_CBERROR;
 209
 210       for (i = 0; i < svc_max_pollfd; ++i)
 211         {
 212           my_pollfd[i].fd = svc_pollfd[i].fd;
 213           my_pollfd[i].events = svc_pollfd[i].events;
 214           my_pollfd[i].revents = 0;
 215         }
 216
 217       switch (i = TEMP_FAILURE_RETRY (__poll (my_pollfd, svc_max_pollfd,
 218                                               25*1000)))
 219         {
 220         case -1:
 221           return NIS_CBERROR;
 222         case 0:
 223           /* See if callback 'thread' in the server is still alive. */
 224           cb_is_running = FALSE;
 225           if (clnt_call (bptr->clnt, NIS_CALLBACK, (xdrproc_t) xdr_netobj,
 226                          (caddr_t) cookie, (xdrproc_t) xdr_bool,
 227                          (caddr_t) &cb_is_running, TIMEOUT) != RPC_SUCCESS)
 228             cb_is_running = FALSE;
 229
 230           if (cb_is_running == FALSE)
 231             {
 232               syslog (LOG_ERR, "NIS+: callback timed out");
 233               return NIS_CBERROR;
 234             }
 235           break;
 236         default:
 237           svc_getreq_poll (my_pollfd, i);
 238           if (data->nomore)
 239             return data->result;
 240         }
 241     }
 242 }
 243
 244 nis_error
 245 __nis_do_callback (struct dir_binding *bptr, netobj *cookie,
 246                    struct nis_cb *cb)
 247 {
 248   nis_error result;
 249
 250   __libc_lock_lock (callback);
 251
 252   result = internal_nis_do_callback (bptr, cookie, cb);
 253
 254   __libc_lock_unlock (callback);
 255
 256   return result;
 257 }
 258
 259 struct nis_cb *
 260 __nis_create_callback (int (*callback) (const_nis_name, const nis_object *,
 261                                         const void *),
 262                        const void *userdata, unsigned int flags)
 263 {
 264   struct nis_cb *cb;
 265   int sock = RPC_ANYSOCK;
 266   struct sockaddr_in sin;
 267   socklen_t len = sizeof (struct sockaddr_in);
 268   unsigned short port;
 269   int nomsg = 0;
 270
 271   cb = (struct nis_cb *) calloc (1,
 272                                  sizeof (struct nis_cb) + sizeof (nis_server));
 273   if (__glibc_unlikely (cb == NULL))
 274     goto failed;
 275   cb->serv = (nis_server *) (cb + 1);
 276   cb->serv->name = strdup (nis_local_principal ());
 277   if (__glibc_unlikely (cb->serv->name == NULL))
 278     goto failed;
 279   cb->serv->ep.ep_val = (endpoint *) calloc (2, sizeof (endpoint));
 280   if (__glibc_unlikely (cb->serv->ep.ep_val == NULL))
 281     goto failed;
 282   cb->serv->ep.ep_len = 1;
 283   cb->serv->ep.ep_val[0].family = strdup ("inet");
 284   if (__glibc_unlikely (cb->serv->ep.ep_val[0].family == NULL))
 285     goto failed;
 286   cb->callback = callback;
 287   cb->userdata = userdata;
 288
 289   if ((flags & NO_AUTHINFO) || !key_secretkey_is_set ())
 290     {
 291       cb->serv->key_type = NIS_PK_NONE;
 292       cb->serv->pkey.n_bytes = NULL;
 293       cb->serv->pkey.n_len = 0;
 294     }
 295   else
 296     {
 297 #if 0
 298       if ((cb->serv->pkey.n_bytes = __nis_getpkey (cb->serv->name)) == NULL)
 299         {
 300           cb->serv->pkey.n_len = 0;
 301           cb->serv->key_type = NIS_PK_NONE;
 302         }
 303       else
 304         {
 305           cb->serv->key_type = NIS_PK_DH;
 306           cb->serv->pkey.n_len = strlen(cb->serv->pkey.n_bytes);
 307         }
 308 #else
 309       cb->serv->pkey.n_len =0;
 310       cb->serv->pkey.n_bytes = NULL;
 311       cb->serv->key_type = NIS_PK_NONE;
 312 #endif
 313     }
 314
 315   cb->serv->ep.ep_val[0].proto = strdup ((flags & USE_DGRAM) ? "udp" : "tcp");
 316   if (__glibc_unlikely (cb->serv->ep.ep_val[0].proto == NULL))
 317     goto failed;
 318   cb->xprt = ((flags & USE_DGRAM)
 319               ? svcudp_bufcreate (sock, 100, 8192)
 320               : svctcp_create (sock, 100, 8192));
 321   if (cb->xprt == NULL)
 322     {
 323       nomsg = 1;
 324       goto failed;
 325     }
 326   cb->sock = cb->xprt->xp_sock;
 327   if (!svc_register (cb->xprt, CB_PROG, CB_VERS, cb_prog_1, 0))
 328     {
 329       xprt_unregister (cb->xprt);
 330       svc_destroy (cb->xprt);
 331       xdr_free ((xdrproc_t) _xdr_nis_server, (char *) cb->serv);
 332       free (cb);
 333       syslog (LOG_ERR, "NIS+: failed to register callback dispatcher");
 334       return NULL;
 335     }
 336
 337   if (getsockname (cb->sock, (struct sockaddr *) &sin, &len) == -1)
 338     {
 339       xprt_unregister (cb->xprt);
 340       svc_destroy (cb->xprt);
 341       xdr_free ((xdrproc_t) _xdr_nis_server, (char *) cb->serv);
 342       free (cb);
 343       syslog (LOG_ERR, "NIS+: failed to read local socket info");
 344       return NULL;
 345     }
 346   port = ntohs (sin.sin_port);
 347   get_myaddress (&sin);
 348
 349   if (asprintf (&cb->serv->ep.ep_val[0].uaddr, "%s.%d.%d",
 350                 inet_ntoa (sin.sin_addr), (port & 0xFF00) >> 8, port & 0x00FF)
 351       < 0)
 352     goto failed;
 353
 354   return cb;
 355
 356  failed:
 357   if (cb)
 358     {
 359       if (cb->xprt)
 360         svc_destroy (cb->xprt);
 361       xdr_free ((xdrproc_t) _xdr_nis_server, (char *) cb->serv);
 362       free (cb);
 363     }
 364   if (!nomsg)
 365     syslog (LOG_ERR, "NIS+: out of memory allocating callback");
 366   return NULL;
 367 }
 368
 369 nis_error
 370 __nis_destroy_callback (struct nis_cb *cb)
 371 {
 372   xprt_unregister (cb->xprt);
 373   svc_destroy (cb->xprt);
 374   close (cb->sock);
 375   xdr_free ((xdrproc_t) _xdr_nis_server, (char *) cb->serv);
 376   free (cb);
 377
 378   return NIS_SUCCESS;
 379 }