check_bound.c revision 330897 
1/*	$NetBSD: check_bound.c,v 1.2 2000/06/22 08:09:26 fvdl Exp $	*/
2/*	$FreeBSD: stable/11/usr.sbin/rpcbind/check_bound.c 330897 2018-03-14 03:19:51Z eadler $ */
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
41static	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
65struct fdlist {
66	int fd;
67	struct netconfig *nconf;
68	struct fdlist *next;
69	int check_binding;
70};
71
72static struct fdlist *fdhead;	/* Link list of the check fd's */
73static struct fdlist *fdtail;
74static char *nullstring = "";
75
76static 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 */
83static bool_t
84check_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
113int
114add_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
143bool_t
144is_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 */
161char *
162mergeaddr(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 */
232struct netconfig *
233rpcbind_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