xref: /freebsd/usr.sbin/rpcbind/check_bound.c (revision 396c556d77189a5c474d35cec6f44a762e310b7d)
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 <stdio.h>
57 #include <netconfig.h>
58 #include <syslog.h>
59 #include <string.h>
60 #include <unistd.h>
61 #include <stdlib.h>
62 
63 #include "rpcbind.h"
64 
65 struct fdlist {
66 	int fd;
67 	struct netconfig *nconf;
68 	struct fdlist *next;
69 	int check_binding;
70 };
71 
72 static struct fdlist *fdhead;	/* Link list of the check fd's */
73 static struct fdlist *fdtail;
74 static char *nullstring = "";
75 
76 static bool_t check_bound(struct fdlist *, char *uaddr);
77 
78 /*
79  * Returns 1 if the given address is bound for the given addr & transport
80  * For all error cases, we assume that the address is bound
81  * Returns 0 for success.
82  */
83 static bool_t
84 check_bound(struct fdlist *fdl, char *uaddr)
85 {
86 	int fd;
87 	struct netbuf *na;
88 	int ans;
89 
90 	if (fdl->check_binding == FALSE)
91 		return (TRUE);
92 
93 	na = uaddr2taddr(fdl->nconf, uaddr);
94 	if (!na)
95 		return (TRUE); /* punt, should never happen */
96 
97 	fd = __rpc_nconf2fd(fdl->nconf);
98 	if (fd < 0) {
99 		free(na->buf);
100 		free(na);
101 		return (TRUE);
102 	}
103 
104 	ans = bind(fd, (struct sockaddr *)na->buf, na->len);
105 
106 	close(fd);
107 	free(na->buf);
108 	free(na);
109 
110 	return (ans == 0 ? FALSE : TRUE);
111 }
112 
113 int
114 add_bndlist(struct netconfig *nconf, struct netbuf *baddr __unused)
115 {
116 	struct fdlist *fdl;
117 	struct netconfig *newnconf;
118 
119 	newnconf = getnetconfigent(nconf->nc_netid);
120 	if (newnconf == NULL)
121 		return (-1);
122 	fdl = malloc(sizeof (struct fdlist));
123 	if (fdl == NULL) {
124 		freenetconfigent(newnconf);
125 		syslog(LOG_ERR, "no memory!");
126 		return (-1);
127 	}
128 	fdl->nconf = newnconf;
129 	fdl->next = NULL;
130 	if (fdhead == NULL) {
131 		fdhead = fdl;
132 		fdtail = fdl;
133 	} else {
134 		fdtail->next = fdl;
135 		fdtail = fdl;
136 	}
137 	/* XXX no bound checking for now */
138 	fdl->check_binding = FALSE;
139 
140 	return 0;
141 }
142 
143 bool_t
144 is_bound(char *netid, char *uaddr)
145 {
146 	struct fdlist *fdl;
147 
148 	for (fdl = fdhead; fdl; fdl = fdl->next)
149 		if (strcmp(fdl->nconf->nc_netid, netid) == 0)
150 			break;
151 	if (fdl == NULL)
152 		return (TRUE);
153 	return (check_bound(fdl, uaddr));
154 }
155 
156 /*
157  * Returns NULL if there was some system error.
158  * Returns "" if the address was not bound, i.e the server crashed.
159  * Returns the merged address otherwise.
160  */
161 char *
162 mergeaddr(SVCXPRT *xprt, char *netid, char *uaddr, char *saddr)
163 {
164 	struct fdlist *fdl;
165 	struct svc_dg_data *dg_data;
166 	char *c_uaddr, *s_uaddr, *m_uaddr, *allocated_uaddr = NULL;
167 
168 	for (fdl = fdhead; fdl; fdl = fdl->next)
169 		if (strcmp(fdl->nconf->nc_netid, netid) == 0)
170 			break;
171 	if (fdl == NULL)
172 		return (NULL);
173 	if (check_bound(fdl, uaddr) == FALSE)
174 		/* that server died */
175 		return (nullstring);
176 	/*
177 	 * Try to determine the local address on which the client contacted us,
178 	 * so we can send a reply from the same address.  If it's unknown, then
179 	 * try to determine which address the client used, and pick a nearby
180 	 * local address.
181 	 *
182 	 * If saddr is not NULL, the remote client may have included the
183 	 * address by which it contacted us.  Use that for the "client" uaddr,
184 	 * otherwise use the info from the SVCXPRT.
185 	 */
186 	dg_data = (struct svc_dg_data*)xprt->xp_p2;
187 	if (dg_data != NULL && dg_data->su_srcaddr.buf != NULL) {
188 		c_uaddr = taddr2uaddr(fdl->nconf, &dg_data->su_srcaddr);
189 		allocated_uaddr = c_uaddr;
190 	}
191 	else if (saddr != NULL) {
192 		c_uaddr = saddr;
193 	} else {
194 		c_uaddr = taddr2uaddr(fdl->nconf, svc_getrpccaller(xprt));
195 		allocated_uaddr = c_uaddr;
196 	}
197 	if (c_uaddr == NULL) {
198 		syslog(LOG_ERR, "taddr2uaddr failed for %s",
199 			fdl->nconf->nc_netid);
200 		return (NULL);
201 	}
202 
203 #ifdef ND_DEBUG
204 	if (debugging) {
205 		if (saddr == NULL) {
206 			fprintf(stderr, "mergeaddr: client uaddr = %s\n",
207 			    c_uaddr);
208 		} else {
209 			fprintf(stderr, "mergeaddr: contact uaddr = %s\n",
210 			    c_uaddr);
211 		}
212 	}
213 #endif
214 	s_uaddr = uaddr;
215 	/*
216 	 * This is all we should need for IP 4 and 6
217 	 */
218 	m_uaddr = addrmerge(svc_getrpccaller(xprt), s_uaddr, c_uaddr, netid);
219 #ifdef ND_DEBUG
220 	if (debugging)
221 		fprintf(stderr, "mergeaddr: uaddr = %s, merged uaddr = %s\n",
222 				uaddr, m_uaddr);
223 #endif
224 	free(allocated_uaddr);
225 	return (m_uaddr);
226 }
227 
228 /*
229  * Returns a netconf structure from its internal list.  This
230  * structure should not be freed.
231  */
232 struct netconfig *
233 rpcbind_get_conf(const char *netid)
234 {
235 	struct fdlist *fdl;
236 
237 	for (fdl = fdhead; fdl; fdl = fdl->next)
238 		if (strcmp(fdl->nconf->nc_netid, netid) == 0)
239 			break;
240 	if (fdl == NULL)
241 		return (NULL);
242 	return (fdl->nconf);
243 }
244