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