xref: /freebsd/usr.sbin/rpcbind/check_bound.c (revision 2008043f386721d58158e37e0d7e50df8095942d)
1 /*	$NetBSD: check_bound.c,v 1.2 2000/06/22 08:09:26 fvdl Exp $	*/
2 
3 /*-
4  * SPDX-License-Identifier: BSD-3-Clause
5  *
6  * Copyright (c) 2009, Sun Microsystems, Inc.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions are met:
11  * - Redistributions of source code must retain the above copyright notice,
12  *   this list of conditions and the following disclaimer.
13  * - Redistributions in binary form must reproduce the above copyright notice,
14  *   this list of conditions and the following disclaimer in the documentation
15  *   and/or other materials provided with the distribution.
16  * - Neither the name of Sun Microsystems, Inc. nor the names of its
17  *   contributors may be used to endorse or promote products derived
18  *   from this software without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
21  * AND 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 THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
24  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 /*
33  * Copyright (c) 1986 - 1991 by Sun Microsystems, Inc.
34  */
35 
36 /* #ident	"@(#)check_bound.c	1.15	93/07/05 SMI" */
37 
38 #if 0
39 #ifndef lint
40 static	char sccsid[] = "@(#)check_bound.c 1.11 89/04/21 Copyr 1989 Sun Micro";
41 #endif
42 #endif
43 
44 /*
45  * check_bound.c
46  * Checks to see whether the program is still bound to the
47  * claimed address and returns the universal merged address
48  *
49  */
50 
51 #include <sys/types.h>
52 #include <sys/socket.h>
53 #include <rpc/rpc.h>
54 #include <rpc/svc_dg.h>
55 #include <netconfig.h>
56 #include <syslog.h>
57 #include <string.h>
58 #include <unistd.h>
59 #include <stdlib.h>
60 
61 #include "rpcbind.h"
62 
63 struct fdlist {
64 	int fd;
65 	struct netconfig *nconf;
66 	struct fdlist *next;
67 	int check_binding;
68 };
69 
70 static struct fdlist *fdhead;	/* Link list of the check fd's */
71 static struct fdlist *fdtail;
72 static char *nullstring = "";
73 
74 static bool_t check_bound(struct fdlist *, char *uaddr);
75 
76 /*
77  * Returns 1 if the given address is bound for the given addr & transport
78  * For all error cases, we assume that the address is bound
79  * Returns 0 for success.
80  */
81 static bool_t
82 check_bound(struct fdlist *fdl, char *uaddr)
83 {
84 	int fd;
85 	struct netbuf *na;
86 	int ans;
87 
88 	if (fdl->check_binding == FALSE)
89 		return (TRUE);
90 
91 	na = uaddr2taddr(fdl->nconf, uaddr);
92 	if (!na)
93 		return (TRUE); /* punt, should never happen */
94 
95 	fd = __rpc_nconf2fd(fdl->nconf);
96 	if (fd < 0) {
97 		free(na->buf);
98 		free(na);
99 		return (TRUE);
100 	}
101 
102 	ans = bind(fd, (struct sockaddr *)na->buf, na->len);
103 
104 	close(fd);
105 	free(na->buf);
106 	free(na);
107 
108 	return (ans == 0 ? FALSE : TRUE);
109 }
110 
111 int
112 add_bndlist(struct netconfig *nconf, struct netbuf *baddr __unused)
113 {
114 	struct fdlist *fdl;
115 	struct netconfig *newnconf;
116 
117 	newnconf = getnetconfigent(nconf->nc_netid);
118 	if (newnconf == NULL)
119 		return (-1);
120 	fdl = malloc(sizeof (struct fdlist));
121 	if (fdl == NULL) {
122 		freenetconfigent(newnconf);
123 		syslog(LOG_ERR, "no memory!");
124 		return (-1);
125 	}
126 	fdl->nconf = newnconf;
127 	fdl->next = NULL;
128 	if (fdhead == NULL) {
129 		fdhead = fdl;
130 		fdtail = fdl;
131 	} else {
132 		fdtail->next = fdl;
133 		fdtail = fdl;
134 	}
135 	/* XXX no bound checking for now */
136 	fdl->check_binding = FALSE;
137 
138 	return 0;
139 }
140 
141 bool_t
142 is_bound(char *netid, char *uaddr)
143 {
144 	struct fdlist *fdl;
145 
146 	for (fdl = fdhead; fdl; fdl = fdl->next)
147 		if (strcmp(fdl->nconf->nc_netid, netid) == 0)
148 			break;
149 	if (fdl == NULL)
150 		return (TRUE);
151 	return (check_bound(fdl, uaddr));
152 }
153 
154 /*
155  * Returns NULL if there was some system error.
156  * Returns "" if the address was not bound, i.e the server crashed.
157  * Returns the merged address otherwise.
158  */
159 char *
160 mergeaddr(SVCXPRT *xprt, char *netid, char *uaddr, char *saddr)
161 {
162 	struct fdlist *fdl;
163 	struct netbuf *callee;
164 	char *c_uaddr, *s_uaddr, *m_uaddr, *allocated_uaddr = NULL;
165 
166 	for (fdl = fdhead; fdl; fdl = fdl->next)
167 		if (strcmp(fdl->nconf->nc_netid, netid) == 0)
168 			break;
169 	if (fdl == NULL)
170 		return (NULL);
171 	if (check_bound(fdl, uaddr) == FALSE)
172 		/* that server died */
173 		return (nullstring);
174 	/*
175 	 * Try to determine the local address on which the client contacted us,
176 	 * so we can send a reply from the same address.  If it's unknown, then
177 	 * try to determine which address the client used, and pick a nearby
178 	 * local address.
179 	 *
180 	 * If saddr is not NULL, the remote client may have included the
181 	 * address by which it contacted us.  Use that for the "client" uaddr,
182 	 * otherwise use the info from the SVCXPRT.
183 	 */
184 	callee = svc_getrpccallee(xprt);
185 	if (callee != NULL && callee->buf != NULL) {
186 		c_uaddr = taddr2uaddr(fdl->nconf, callee);
187 		allocated_uaddr = c_uaddr;
188 	} else if (saddr != NULL) {
189 		c_uaddr = saddr;
190 	} else {
191 		c_uaddr = taddr2uaddr(fdl->nconf, svc_getrpccaller(xprt));
192 		allocated_uaddr = c_uaddr;
193 	}
194 	if (c_uaddr == NULL) {
195 		syslog(LOG_ERR, "taddr2uaddr failed for %s",
196 			fdl->nconf->nc_netid);
197 		return (NULL);
198 	}
199 
200 #ifdef ND_DEBUG
201 	if (debugging) {
202 		if (saddr == NULL) {
203 			fprintf(stderr, "mergeaddr: client uaddr = %s\n",
204 			    c_uaddr);
205 		} else {
206 			fprintf(stderr, "mergeaddr: contact uaddr = %s\n",
207 			    c_uaddr);
208 		}
209 	}
210 #endif
211 	s_uaddr = uaddr;
212 	/*
213 	 * This is all we should need for IP 4 and 6
214 	 */
215 	m_uaddr = addrmerge(svc_getrpccaller(xprt), s_uaddr, c_uaddr, netid);
216 #ifdef ND_DEBUG
217 	if (debugging)
218 		fprintf(stderr, "mergeaddr: uaddr = %s, merged uaddr = %s\n",
219 				uaddr, m_uaddr);
220 #endif
221 	free(allocated_uaddr);
222 	return (m_uaddr);
223 }
224 
225 /*
226  * Returns a netconf structure from its internal list.  This
227  * structure should not be freed.
228  */
229 struct netconfig *
230 rpcbind_get_conf(const char *netid)
231 {
232 	struct fdlist *fdl;
233 
234 	for (fdl = fdhead; fdl; fdl = fdl->next)
235 		if (strcmp(fdl->nconf->nc_netid, netid) == 0)
236 			break;
237 	if (fdl == NULL)
238 		return (NULL);
239 	return (fdl->nconf);
240 }
241