yp*(8): Fix building with -fno-common.
[dragonfly.git] / usr.sbin / ypserv / yp_access.c
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1/*
2 * Copyright (c) 1995
3 * Bill Paul <wpaul@ctr.columbia.edu>. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by Bill Paul.
16 * 4. Neither the name of the author nor the names of any co-contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL Bill Paul OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
ce0e08e2 32 * $FreeBSD: src/usr.sbin/ypserv/yp_access.c,v 1.23 2006/05/31 22:31:08 cperciva Exp $
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33 */
34
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35#include <stdlib.h>
36#include <rpc/rpc.h>
37#include <rpcsvc/yp.h>
38#include <rpcsvc/yppasswd.h>
39#include <rpcsvc/ypxfrd.h>
40#include <sys/types.h>
41#include <limits.h>
42#include <db.h>
43#include <sys/socket.h>
44#include <netinet/in.h>
45#include <arpa/inet.h>
46#include <sys/stat.h>
47#include <sys/fcntl.h>
48#include <paths.h>
49#include <errno.h>
50#include <sys/param.h>
51#include "yp_extern.h"
52#ifdef TCP_WRAPPER
53#include "tcpd.h"
54#endif
55
b90fe988 56static const char *yp_procs[] = {
04277bb2 57 /* NIS v1 */
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58 "ypoldproc_null",
59 "ypoldproc_domain",
60 "ypoldproc_domain_nonack",
61 "ypoldproc_match",
62 "ypoldproc_first",
63 "ypoldproc_next",
64 "ypoldproc_poll",
65 "ypoldproc_push",
66 "ypoldproc_get",
67 "badproc1", /* placeholder */
68 "badproc2", /* placeholder */
69 "badproc3", /* placeholder */
70
71 /* NIS v2 */
72 "ypproc_null",
73 "ypproc_domain",
74 "ypproc_domain_nonack",
75 "ypproc_match",
76 "ypproc_first",
77 "ypproc_next",
78 "ypproc_xfr",
79 "ypproc_clear",
80 "ypproc_all",
81 "ypproc_master",
82 "ypproc_order",
83 "ypproc_maplist"
84};
984263bc 85
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86struct securenet {
87 struct in_addr net;
88 struct in_addr mask;
89 struct securenet *next;
90};
91
b90fe988 92static struct securenet *securenets;
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93
94#define LINEBUFSZ 1024
95
96/*
97 * Read /var/yp/securenets file and initialize the securenets
98 * list. If the file doesn't exist, we set up a dummy entry that
99 * allows all hosts to connect.
100 */
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101void
102load_securenets(void)
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103{
104 FILE *fp;
105 char path[MAXPATHLEN + 2];
106 char linebuf[1024 + 2];
107 struct securenet *tmp;
108
109 /*
110 * If securenets is not NULL, we are being called to reload
111 * the list; free the existing list before re-reading the
112 * securenets file.
113 */
114 while (securenets) {
115 tmp = securenets->next;
116 free(securenets);
117 securenets = tmp;
118 }
119
120 snprintf(path, MAXPATHLEN, "%s/securenets", yp_dir);
121
122 if ((fp = fopen(path, "r")) == NULL) {
123 if (errno == ENOENT) {
124 securenets = (struct securenet *)malloc(sizeof(struct securenet));
125 securenets->net.s_addr = INADDR_ANY;
126 securenets->mask.s_addr = INADDR_ANY;
127 securenets->next = NULL;
128 return;
129 } else {
130 yp_error("fopen(%s) failed: %s", path, strerror(errno));
131 exit(1);
132 }
133 }
134
135 securenets = NULL;
136
137 while (fgets(linebuf, LINEBUFSZ, fp)) {
138 char addr1[20], addr2[20];
139
140 if ((linebuf[0] == '#')
141 || (strspn(linebuf, " \t\r\n") == strlen(linebuf)))
142 continue;
143 if (sscanf(linebuf, "%s %s", addr1, addr2) < 2) {
144 yp_error("badly formatted securenets entry: %s",
145 linebuf);
146 continue;
147 }
148
149 tmp = (struct securenet *)malloc(sizeof(struct securenet));
150
151 if (!inet_aton((char *)&addr1, (struct in_addr *)&tmp->net)) {
152 yp_error("badly formatted securenets entry: %s", addr1);
153 free(tmp);
154 continue;
155 }
156
157 if (!inet_aton((char *)&addr2, (struct in_addr *)&tmp->mask)) {
158 yp_error("badly formatted securenets entry: %s", addr2);
159 free(tmp);
160 continue;
161 }
162
163 tmp->next = securenets;
164 securenets = tmp;
165 }
166
167 fclose(fp);
168
169}
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170
171/*
172 * Access control functions.
173 *
174 * yp_access() checks the mapname and client host address and watches for
175 * the following things:
176 *
177 * - If the client is referencing one of the master.passwd.* maps, it must
178 * be using a privileged port to make its RPC to us. If it is, then we can
179 * assume that the caller is root and allow the RPC to succeed. If it
180 * isn't access is denied.
181 *
182 * - The client's IP address is checked against the securenets rules.
183 * There are two kinds of securenets support: the built-in support,
184 * which is very simple and depends on the presence of a
185 * /var/yp/securenets file, and tcp-wrapper support, which requires
186 * Wietse Venema's libwrap.a and tcpd.h. (Since the tcp-wrapper
187 * package does not ship with FreeBSD, we use the built-in support
188 * by default. Users can recompile the server with the tcp-wrapper library
189 * if they already have it installed and want to use hosts.allow and
7a44d1cb 190 * hosts.deny to control access instead of having a separate securenets
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191 * file.)
192 *
193 * If no /var/yp/securenets file is present, the host access checks
194 * are bypassed and all hosts are allowed to connect.
195 *
196 * The yp_validdomain() function checks the domain specified by the caller
197 * to make sure it's actually served by this server. This is more a sanity
198 * check than an a security check, but this seems to be the best place for
199 * it.
200 */
201
202#ifdef DB_CACHE
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203int
204yp_access(const char *map, const char *domain, const struct svc_req *rqstp)
984263bc 205#else
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206int
207yp_access(const char *map, const struct svc_req *rqstp)
984263bc 208#endif
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209{
210 struct sockaddr_in *rqhost;
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211 int status_securenets = 0;
212#ifdef TCP_WRAPPER
213 int status_tcpwrap;
214#endif
984263bc 215 static unsigned long oldaddr = 0;
984263bc 216 struct securenet *tmp;
ce0e08e2 217 const char *yp_procedure = NULL;
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218 char procbuf[50];
219
220 if (rqstp->rq_prog != YPPASSWDPROG && rqstp->rq_prog != YPPROG) {
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221 snprintf(procbuf, sizeof(procbuf), "#%lu/#%lu",
222 (unsigned long)rqstp->rq_prog,
223 (unsigned long)rqstp->rq_proc);
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224 yp_procedure = (char *)&procbuf;
225 } else {
226 yp_procedure = rqstp->rq_prog == YPPASSWDPROG ?
227 "yppasswdprog_update" :
228 yp_procs[rqstp->rq_proc + (12 * (rqstp->rq_vers - 1))];
229 }
230
231 rqhost = svc_getcaller(rqstp->rq_xprt);
232
233 if (debug) {
234 yp_error("procedure %s called from %s:%d", yp_procedure,
235 inet_ntoa(rqhost->sin_addr),
236 ntohs(rqhost->sin_port));
237 if (map != NULL)
238 yp_error("client is referencing map \"%s\".", map);
239 }
240
241 /* Check the map name if one was supplied. */
242 if (map != NULL) {
243 if (strchr(map, '/')) {
244 yp_error("embedded slash in map name \"%s\" -- \
245possible spoof attempt from %s:%d",
246 map, inet_ntoa(rqhost->sin_addr),
247 ntohs(rqhost->sin_port));
248 return(1);
249 }
250#ifdef DB_CACHE
251 if ((yp_testflag((char *)map, (char *)domain, YP_SECURE) ||
252#else
253 if ((strstr(map, "master.passwd.") ||
254#endif
255 (rqstp->rq_prog == YPPROG &&
256 rqstp->rq_proc == YPPROC_XFR) ||
257 (rqstp->rq_prog == YPXFRD_FREEBSD_PROG &&
258 rqstp->rq_proc == YPXFRD_GETMAP)) &&
259 ntohs(rqhost->sin_port) >= IPPORT_RESERVED) {
260 yp_error("access to %s denied -- client %s:%d \
261not privileged", map, inet_ntoa(rqhost->sin_addr), ntohs(rqhost->sin_port));
262 return(1);
263 }
264 }
265
266#ifdef TCP_WRAPPER
280b7f98 267 status_tcpwrap = hosts_ctl("ypserv", STRING_UNKNOWN,
984263bc 268 inet_ntoa(rqhost->sin_addr), "");
280b7f98 269#endif
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270 tmp = securenets;
271 while (tmp) {
272 if (((rqhost->sin_addr.s_addr & ~tmp->mask.s_addr)
273 | tmp->net.s_addr) == rqhost->sin_addr.s_addr) {
280b7f98 274 status_securenets = 1;
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275 break;
276 }
277 tmp = tmp->next;
278 }
984263bc 279
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280#ifdef TCP_WRAPPER
281 if (status_securenets == 0 || status_tcpwrap == 0) {
282#else
283 if (status_securenets == 0) {
284#endif
285 /*
b90fe988 286 * One of the following two events occurred:
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287 *
288 * (1) The /var/yp/securenets exists and the remote host does not
289 * match any of the networks specified in it.
290 * (2) The hosts.allow file has denied access and TCP_WRAPPER is
291 * defined.
292 *
293 * In either case deny access.
294 */
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295 if (rqhost->sin_addr.s_addr != oldaddr) {
296 yp_error("connect from %s:%d to procedure %s refused",
297 inet_ntoa(rqhost->sin_addr),
298 ntohs(rqhost->sin_port),
299 yp_procedure);
300 oldaddr = rqhost->sin_addr.s_addr;
301 }
302 return(1);
303 }
304 return(0);
305
306}
307
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308int
309yp_validdomain(const char *domain)
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310{
311 struct stat statbuf;
312 char dompath[MAXPATHLEN + 2];
313
314 if (domain == NULL || strstr(domain, "binding") ||
315 !strcmp(domain, ".") || !strcmp(domain, "..") ||
316 strchr(domain, '/') || strlen(domain) > YPMAXDOMAIN)
317 return(1);
318
319 snprintf(dompath, sizeof(dompath), "%s/%s", yp_dir, domain);
320
321 if (stat(dompath, &statbuf) < 0 || !S_ISDIR(statbuf.st_mode))
322 return(1);
323
324
325 return(0);
326}