xref: /freebsd/usr.sbin/rpcbind/check_bound.c (revision f39bffc62c1395bde25d152c7f68fdf7cbaab414)
1 /*	$NetBSD: check_bound.c,v 1.2 2000/06/22 08:09:26 fvdl Exp $	*/
2 /*	$FreeBSD$ */
3 
4 /*-
5  * SPDX-License-Identifier: BSD-3-Clause
6  *
7  * Copyright (c) 2009, Sun Microsystems, Inc.
8  * All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions are met:
12  * - Redistributions of source code must retain the above copyright notice,
13  *   this list of conditions and the following disclaimer.
14  * - Redistributions in binary form must reproduce the above copyright notice,
15  *   this list of conditions and the following disclaimer in the documentation
16  *   and/or other materials provided with the distribution.
17  * - Neither the name of Sun Microsystems, Inc. nor the names of its
18  *   contributors may be used to endorse or promote products derived
19  *   from this software without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
22  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
25  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31  * POSSIBILITY OF SUCH DAMAGE.
32  */
33 /*
34  * Copyright (c) 1986 - 1991 by Sun Microsystems, Inc.
35  */
36 
37 /* #ident	"@(#)check_bound.c	1.15	93/07/05 SMI" */
38 
39 #if 0
40 #ifndef lint
41 static	char sccsid[] = "@(#)check_bound.c 1.11 89/04/21 Copyr 1989 Sun Micro";
42 #endif
43 #endif
44 
45 /*
46  * check_bound.c
47  * Checks to see whether the program is still bound to the
48  * claimed address and returns the universal merged address
49  *
50  */
51 
52 #include <sys/types.h>
53 #include <sys/socket.h>
54 #include <rpc/rpc.h>
55 #include <rpc/svc_dg.h>
56 #include <netconfig.h>
57 #include <syslog.h>
58 #include <string.h>
59 #include <unistd.h>
60 #include <stdlib.h>
61 
62 #include "rpcbind.h"
63 
64 struct fdlist {
65 	int fd;
66 	struct netconfig *nconf;
67 	struct fdlist *next;
68 	int check_binding;
69 };
70 
71 static struct fdlist *fdhead;	/* Link list of the check fd's */
72 static struct fdlist *fdtail;
73 static char *nullstring = "";
74 
75 static bool_t check_bound(struct fdlist *, char *uaddr);
76 
77 /*
78  * Returns 1 if the given address is bound for the given addr & transport
79  * For all error cases, we assume that the address is bound
80  * Returns 0 for success.
81  */
82 static bool_t
83 check_bound(struct fdlist *fdl, char *uaddr)
84 {
85 	int fd;
86 	struct netbuf *na;
87 	int ans;
88 
89 	if (fdl->check_binding == FALSE)
90 		return (TRUE);
91 
92 	na = uaddr2taddr(fdl->nconf, uaddr);
93 	if (!na)
94 		return (TRUE); /* punt, should never happen */
95 
96 	fd = __rpc_nconf2fd(fdl->nconf);
97 	if (fd < 0) {
98 		free(na->buf);
99 		free(na);
100 		return (TRUE);
101 	}
102 
103 	ans = bind(fd, (struct sockaddr *)na->buf, na->len);
104 
105 	close(fd);
106 	free(na->buf);
107 	free(na);
108 
109 	return (ans == 0 ? FALSE : TRUE);
110 }
111 
112 int
113 add_bndlist(struct netconfig *nconf, struct netbuf *baddr __unused)
114 {
115 	struct fdlist *fdl;
116 	struct netconfig *newnconf;
117 
118 	newnconf = getnetconfigent(nconf->nc_netid);
119 	if (newnconf == NULL)
120 		return (-1);
121 	fdl = malloc(sizeof (struct fdlist));
122 	if (fdl == NULL) {
123 		freenetconfigent(newnconf);
124 		syslog(LOG_ERR, "no memory!");
125 		return (-1);
126 	}
127 	fdl->nconf = newnconf;
128 	fdl->next = NULL;
129 	if (fdhead == NULL) {
130 		fdhead = fdl;
131 		fdtail = fdl;
132 	} else {
133 		fdtail->next = fdl;
134 		fdtail = fdl;
135 	}
136 	/* XXX no bound checking for now */
137 	fdl->check_binding = FALSE;
138 
139 	return 0;
140 }
141 
142 bool_t
143 is_bound(char *netid, char *uaddr)
144 {
145 	struct fdlist *fdl;
146 
147 	for (fdl = fdhead; fdl; fdl = fdl->next)
148 		if (strcmp(fdl->nconf->nc_netid, netid) == 0)
149 			break;
150 	if (fdl == NULL)
151 		return (TRUE);
152 	return (check_bound(fdl, uaddr));
153 }
154 
155 /*
156  * Returns NULL if there was some system error.
157  * Returns "" if the address was not bound, i.e the server crashed.
158  * Returns the merged address otherwise.
159  */
160 char *
161 mergeaddr(SVCXPRT *xprt, char *netid, char *uaddr, char *saddr)
162 {
163 	struct fdlist *fdl;
164 	struct svc_dg_data *dg_data;
165 	char *c_uaddr, *s_uaddr, *m_uaddr, *allocated_uaddr = NULL;
166 
167 	for (fdl = fdhead; fdl; fdl = fdl->next)
168 		if (strcmp(fdl->nconf->nc_netid, netid) == 0)
169 			break;
170 	if (fdl == NULL)
171 		return (NULL);
172 	if (check_bound(fdl, uaddr) == FALSE)
173 		/* that server died */
174 		return (nullstring);
175 	/*
176 	 * Try to determine the local address on which the client contacted us,
177 	 * so we can send a reply from the same address.  If it's unknown, then
178 	 * try to determine which address the client used, and pick a nearby
179 	 * local address.
180 	 *
181 	 * If saddr is not NULL, the remote client may have included the
182 	 * address by which it contacted us.  Use that for the "client" uaddr,
183 	 * otherwise use the info from the SVCXPRT.
184 	 */
185 	dg_data = (struct svc_dg_data*)xprt->xp_p2;
186 	if (dg_data != NULL && dg_data->su_srcaddr.buf != NULL) {
187 		c_uaddr = taddr2uaddr(fdl->nconf, &dg_data->su_srcaddr);
188 		allocated_uaddr = c_uaddr;
189 	}
190 	else if (saddr != NULL) {
191 		c_uaddr = saddr;
192 	} else {
193 		c_uaddr = taddr2uaddr(fdl->nconf, svc_getrpccaller(xprt));
194 		allocated_uaddr = c_uaddr;
195 	}
196 	if (c_uaddr == NULL) {
197 		syslog(LOG_ERR, "taddr2uaddr failed for %s",
198 			fdl->nconf->nc_netid);
199 		return (NULL);
200 	}
201 
202 #ifdef ND_DEBUG
203 	if (debugging) {
204 		if (saddr == NULL) {
205 			fprintf(stderr, "mergeaddr: client uaddr = %s\n",
206 			    c_uaddr);
207 		} else {
208 			fprintf(stderr, "mergeaddr: contact uaddr = %s\n",
209 			    c_uaddr);
210 		}
211 	}
212 #endif
213 	s_uaddr = uaddr;
214 	/*
215 	 * This is all we should need for IP 4 and 6
216 	 */
217 	m_uaddr = addrmerge(svc_getrpccaller(xprt), s_uaddr, c_uaddr, netid);
218 #ifdef ND_DEBUG
219 	if (debugging)
220 		fprintf(stderr, "mergeaddr: uaddr = %s, merged uaddr = %s\n",
221 				uaddr, m_uaddr);
222 #endif
223 	free(allocated_uaddr);
224 	return (m_uaddr);
225 }
226 
227 /*
228  * Returns a netconf structure from its internal list.  This
229  * structure should not be freed.
230  */
231 struct netconfig *
232 rpcbind_get_conf(const char *netid)
233 {
234 	struct fdlist *fdl;
235 
236 	for (fdl = fdhead; fdl; fdl = fdl->next)
237 		if (strcmp(fdl->nconf->nc_netid, netid) == 0)
238 			break;
239 	if (fdl == NULL)
240 		return (NULL);
241 	return (fdl->nconf);
242 }
243