xref: /freebsd/usr.sbin/rpcbind/check_bound.c (revision a2f733abcff64628b7771a47089628b7327a88bd)
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 #if 0
37 #endif
38 
39 /*
40  * check_bound.c
41  * Checks to see whether the program is still bound to the
42  * claimed address and returns the universal merged address
43  *
44  */
45 
46 #include <sys/types.h>
47 #include <sys/socket.h>
48 #include <rpc/rpc.h>
49 #include <rpc/svc_dg.h>
50 #include <netconfig.h>
51 #include <syslog.h>
52 #include <string.h>
53 #include <unistd.h>
54 #include <stdlib.h>
55 
56 #include "rpcbind.h"
57 
58 struct fdlist {
59 	int fd;
60 	struct netconfig *nconf;
61 	struct fdlist *next;
62 	int check_binding;
63 };
64 
65 static struct fdlist *fdhead;	/* Link list of the check fd's */
66 static struct fdlist *fdtail;
67 static char *nullstring = "";
68 
69 static bool_t check_bound(struct fdlist *, char *uaddr);
70 
71 /*
72  * Returns 1 if the given address is bound for the given addr & transport
73  * For all error cases, we assume that the address is bound
74  * Returns 0 for success.
75  */
76 static bool_t
77 check_bound(struct fdlist *fdl, char *uaddr)
78 {
79 	int fd;
80 	struct netbuf *na;
81 	int ans;
82 
83 	if (fdl->check_binding == FALSE)
84 		return (TRUE);
85 
86 	na = uaddr2taddr(fdl->nconf, uaddr);
87 	if (!na)
88 		return (TRUE); /* punt, should never happen */
89 
90 	fd = __rpc_nconf2fd(fdl->nconf);
91 	if (fd < 0) {
92 		free(na->buf);
93 		free(na);
94 		return (TRUE);
95 	}
96 
97 	ans = bind(fd, (struct sockaddr *)na->buf, na->len);
98 
99 	close(fd);
100 	free(na->buf);
101 	free(na);
102 
103 	return (ans == 0 ? FALSE : TRUE);
104 }
105 
106 int
107 add_bndlist(struct netconfig *nconf, struct netbuf *baddr __unused)
108 {
109 	struct fdlist *fdl;
110 	struct netconfig *newnconf;
111 
112 	newnconf = getnetconfigent(nconf->nc_netid);
113 	if (newnconf == NULL)
114 		return (-1);
115 	fdl = malloc(sizeof (struct fdlist));
116 	if (fdl == NULL) {
117 		freenetconfigent(newnconf);
118 		syslog(LOG_ERR, "no memory!");
119 		return (-1);
120 	}
121 	fdl->nconf = newnconf;
122 	fdl->next = NULL;
123 	if (fdhead == NULL) {
124 		fdhead = fdl;
125 		fdtail = fdl;
126 	} else {
127 		fdtail->next = fdl;
128 		fdtail = fdl;
129 	}
130 	/* XXX no bound checking for now */
131 	fdl->check_binding = FALSE;
132 
133 	return 0;
134 }
135 
136 bool_t
137 is_bound(char *netid, char *uaddr)
138 {
139 	struct fdlist *fdl;
140 
141 	for (fdl = fdhead; fdl; fdl = fdl->next)
142 		if (strcmp(fdl->nconf->nc_netid, netid) == 0)
143 			break;
144 	if (fdl == NULL)
145 		return (TRUE);
146 	return (check_bound(fdl, uaddr));
147 }
148 
149 /*
150  * Returns NULL if there was some system error.
151  * Returns "" if the address was not bound, i.e the server crashed.
152  * Returns the merged address otherwise.
153  */
154 char *
155 mergeaddr(SVCXPRT *xprt, char *netid, char *uaddr, char *saddr)
156 {
157 	struct fdlist *fdl;
158 	struct netbuf *callee;
159 	char *c_uaddr, *s_uaddr, *m_uaddr, *allocated_uaddr = NULL;
160 
161 	for (fdl = fdhead; fdl; fdl = fdl->next)
162 		if (strcmp(fdl->nconf->nc_netid, netid) == 0)
163 			break;
164 	if (fdl == NULL)
165 		return (NULL);
166 	if (check_bound(fdl, uaddr) == FALSE)
167 		/* that server died */
168 		return (nullstring);
169 	/*
170 	 * Try to determine the local address on which the client contacted us,
171 	 * so we can send a reply from the same address.  If it's unknown, then
172 	 * try to determine which address the client used, and pick a nearby
173 	 * local address.
174 	 *
175 	 * If saddr is not NULL, the remote client may have included the
176 	 * address by which it contacted us.  Use that for the "client" uaddr,
177 	 * otherwise use the info from the SVCXPRT.
178 	 */
179 	callee = svc_getrpccallee(xprt);
180 	if (callee != NULL && callee->buf != NULL) {
181 		c_uaddr = taddr2uaddr(fdl->nconf, callee);
182 		allocated_uaddr = c_uaddr;
183 	} else if (saddr != NULL) {
184 		c_uaddr = saddr;
185 	} else {
186 		c_uaddr = taddr2uaddr(fdl->nconf, svc_getrpccaller(xprt));
187 		allocated_uaddr = c_uaddr;
188 	}
189 	if (c_uaddr == NULL) {
190 		syslog(LOG_ERR, "taddr2uaddr failed for %s",
191 			fdl->nconf->nc_netid);
192 		return (NULL);
193 	}
194 
195 #ifdef ND_DEBUG
196 	if (debugging) {
197 		if (saddr == NULL) {
198 			fprintf(stderr, "mergeaddr: client uaddr = %s\n",
199 			    c_uaddr);
200 		} else {
201 			fprintf(stderr, "mergeaddr: contact uaddr = %s\n",
202 			    c_uaddr);
203 		}
204 	}
205 #endif
206 	s_uaddr = uaddr;
207 	/*
208 	 * This is all we should need for IP 4 and 6
209 	 */
210 	m_uaddr = addrmerge(svc_getrpccaller(xprt), s_uaddr, c_uaddr, netid);
211 #ifdef ND_DEBUG
212 	if (debugging)
213 		fprintf(stderr, "mergeaddr: uaddr = %s, merged uaddr = %s\n",
214 				uaddr, m_uaddr);
215 #endif
216 	free(allocated_uaddr);
217 	return (m_uaddr);
218 }
219 
220 /*
221  * Returns a netconf structure from its internal list.  This
222  * structure should not be freed.
223  */
224 struct netconfig *
225 rpcbind_get_conf(const char *netid)
226 {
227 	struct fdlist *fdl;
228 
229 	for (fdl = fdhead; fdl; fdl = fdl->next)
230 		if (strcmp(fdl->nconf->nc_netid, netid) == 0)
231 			break;
232 	if (fdl == NULL)
233 		return (NULL);
234 	return (fdl->nconf);
235 }
236