2 * SPDX-License-Identifier: BSD-4-Clause
5 * Bill Paul <wpaul@ctr.columbia.edu>. All rights reserved.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgement:
17 * This product includes software developed by Bill Paul.
18 * 4. Neither the name of the author nor the names of any co-contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL Bill Paul OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
41 #include <rpcsvc/yp.h>
42 #include <rpcsvc/yppasswd.h>
43 #include <rpcsvc/ypxfrd.h>
44 #include <sys/types.h>
47 #include <sys/socket.h>
48 #include <netinet/in.h>
49 #include <arpa/inet.h>
51 #include <sys/fcntl.h>
54 #include <sys/param.h>
55 #include "yp_extern.h"
62 static const char *yp_procs[] = {
66 "ypoldproc_domain_nonack",
73 "badproc1", /* placeholder */
74 "badproc2", /* placeholder */
75 "badproc3", /* placeholder */
80 "ypproc_domain_nonack",
95 struct securenet *next;
98 static struct securenet *securenets;
100 #define LINEBUFSZ 1024
103 int hosts_ctl(char *, char *, char *, char *);
107 * Read /var/yp/securenets file and initialize the securenets
108 * list. If the file doesn't exist, we set up a dummy entry that
109 * allows all hosts to connect.
112 load_securenets(void)
115 char path[MAXPATHLEN + 2];
116 char linebuf[1024 + 2];
117 struct securenet *tmp;
120 * If securenets is not NULL, we are being called to reload
121 * the list; free the existing list before re-reading the
125 tmp = securenets->next;
130 snprintf(path, MAXPATHLEN, "%s/securenets", yp_dir);
132 if ((fp = fopen(path, "r")) == NULL) {
133 if (errno == ENOENT) {
134 securenets = malloc(sizeof(struct securenet));
135 securenets->net.s_addr = INADDR_ANY;
136 securenets->mask.s_addr = INADDR_ANY;
137 securenets->next = NULL;
140 yp_error("fopen(%s) failed: %s", path, strerror(errno));
147 while (fgets(linebuf, LINEBUFSZ, fp)) {
148 char addr1[20], addr2[20];
150 if ((linebuf[0] == '#')
151 || (strspn(linebuf, " \t\r\n") == strlen(linebuf)))
153 if (sscanf(linebuf, "%s %s", addr1, addr2) < 2) {
154 yp_error("badly formatted securenets entry: %s",
159 tmp = malloc(sizeof(struct securenet));
161 if (!inet_aton((char *)&addr1, (struct in_addr *)&tmp->net)) {
162 yp_error("badly formatted securenets entry: %s", addr1);
167 if (!inet_aton((char *)&addr2, (struct in_addr *)&tmp->mask)) {
168 yp_error("badly formatted securenets entry: %s", addr2);
173 tmp->next = securenets;
182 * Access control functions.
184 * yp_access() checks the mapname and client host address and watches for
185 * the following things:
187 * - If the client is referencing one of the master.passwd.* or shadow.* maps,
188 * it must be using a privileged port to make its RPC to us. If it is, then
189 * we can assume that the caller is root and allow the RPC to succeed. If it
190 * isn't access is denied.
192 * - The client's IP address is checked against the securenets rules.
193 * There are two kinds of securenets support: the built-in support,
194 * which is very simple and depends on the presence of a
195 * /var/yp/securenets file, and tcp-wrapper support, which requires
196 * Wietse Venema's libwrap.a and tcpd.h. (Since the tcp-wrapper
197 * package does not ship with FreeBSD, we use the built-in support
198 * by default. Users can recompile the server with the tcp-wrapper library
199 * if they already have it installed and want to use hosts.allow and
200 * hosts.deny to control access instead of having a separate securenets
203 * If no /var/yp/securenets file is present, the host access checks
204 * are bypassed and all hosts are allowed to connect.
206 * The yp_validdomain() function checks the domain specified by the caller
207 * to make sure it's actually served by this server. This is more a sanity
208 * check than an a security check, but this seems to be the best place for
214 yp_access(const char *map, const char *domain, const struct svc_req *rqstp)
217 yp_access(const char *map, const struct svc_req *rqstp)
220 struct sockaddr_in *rqhost;
221 int status_securenets = 0;
225 static unsigned long oldaddr = 0;
226 struct securenet *tmp;
227 const char *yp_procedure = NULL;
230 if (rqstp->rq_prog != YPPASSWDPROG && rqstp->rq_prog != YPPROG) {
231 snprintf(procbuf, sizeof(procbuf), "#%lu/#%lu",
232 (unsigned long)rqstp->rq_prog,
233 (unsigned long)rqstp->rq_proc);
234 yp_procedure = (char *)&procbuf;
236 yp_procedure = rqstp->rq_prog == YPPASSWDPROG ?
237 "yppasswdprog_update" :
238 yp_procs[rqstp->rq_proc + (12 * (rqstp->rq_vers - 1))];
241 rqhost = svc_getcaller(rqstp->rq_xprt);
244 yp_error("procedure %s called from %s:%d", yp_procedure,
245 inet_ntoa(rqhost->sin_addr),
246 ntohs(rqhost->sin_port));
248 yp_error("client is referencing map \"%s\".", map);
251 /* Check the map name if one was supplied. */
253 if (strchr(map, '/')) {
254 yp_error("embedded slash in map name \"%s\" -- \
255 possible spoof attempt from %s:%d",
256 map, inet_ntoa(rqhost->sin_addr),
257 ntohs(rqhost->sin_port));
261 if ((yp_testflag((char *)map, (char *)domain, YP_SECURE) ||
263 if ((strstr(map, "master.passwd.") || strstr(map, "shadow.") ||
265 (rqstp->rq_prog == YPPROG &&
266 rqstp->rq_proc == YPPROC_XFR) ||
267 (rqstp->rq_prog == YPXFRD_FREEBSD_PROG &&
268 rqstp->rq_proc == YPXFRD_GETMAP)) &&
269 ntohs(rqhost->sin_port) >= IPPORT_RESERVED) {
270 yp_error("access to %s denied -- client %s:%d \
271 not privileged", map, inet_ntoa(rqhost->sin_addr), ntohs(rqhost->sin_port));
277 status_tcpwrap = hosts_ctl("ypserv", STRING_UNKNOWN,
278 inet_ntoa(rqhost->sin_addr), "");
282 if (((rqhost->sin_addr.s_addr & ~tmp->mask.s_addr)
283 | tmp->net.s_addr) == rqhost->sin_addr.s_addr) {
284 status_securenets = 1;
291 if (status_securenets == 0 || status_tcpwrap == 0) {
293 if (status_securenets == 0) {
296 * One of the following two events occurred:
298 * (1) The /var/yp/securenets exists and the remote host does not
299 * match any of the networks specified in it.
300 * (2) The hosts.allow file has denied access and TCP_WRAPPER is
303 * In either case deny access.
305 if (rqhost->sin_addr.s_addr != oldaddr) {
306 yp_error("connect from %s:%d to procedure %s refused",
307 inet_ntoa(rqhost->sin_addr),
308 ntohs(rqhost->sin_port),
310 oldaddr = rqhost->sin_addr.s_addr;
319 yp_validdomain(const char *domain)
322 char dompath[MAXPATHLEN + 2];
324 if (domain == NULL || strstr(domain, "binding") ||
325 !strcmp(domain, ".") || !strcmp(domain, "..") ||
326 strchr(domain, '/') || strlen(domain) > YPMAXDOMAIN)
329 snprintf(dompath, sizeof(dompath), "%s/%s", yp_dir, domain);
331 if (stat(dompath, &statbuf) < 0 || !S_ISDIR(statbuf.st_mode))