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 
__libc_lock_define_initialized(static,callback)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
internal_nis_do_callback(struct dir_binding * bptr,netobj * cookie,struct nis_cb * cb)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
__nis_do_callback(struct dir_binding * bptr,netobj * cookie,struct nis_cb * cb)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 *
__nis_create_callback(int (* callback)(const_nis_name,const nis_object *,const void *),const void * userdata,unsigned int flags)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
__nis_destroy_callback(struct nis_cb * cb)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 }
380