xref: /netbsd-src/usr.sbin/rpcbind/check_bound.c (revision deb6f0161a9109e7de9b519dc8dfb9478668dcdd)
1 /*	$NetBSD: check_bound.c,v 1.7 2017/08/16 08:44:40 christos Exp $	*/
2 /*	$FreeBSD: head/usr.sbin/rpcbind/check_bound.c 300942 2016-05-29 06:01:18Z ngie $ */
3 
4 /*-
5  * Copyright (c) 2009, Sun Microsystems, Inc.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions are met:
10  * - Redistributions of source code must retain the above copyright notice,
11  *   this list of conditions and the following disclaimer.
12  * - Redistributions in binary form must reproduce the above copyright notice,
13  *   this list of conditions and the following disclaimer in the documentation
14  *   and/or other materials provided with the distribution.
15  * - Neither the name of Sun Microsystems, Inc. nor the names of its
16  *   contributors may be used to endorse or promote products derived
17  *   from this software without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
20  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
23  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 /*
32  * Copyright (c) 1986 - 1991 by Sun Microsystems, Inc.
33  */
34 
35 /* #ident	"@(#)check_bound.c	1.15	93/07/05 SMI" */
36 
37 #if 0
38 #ifndef lint
39 static	char sccsid[] = "@(#)check_bound.c 1.11 89/04/21 Copyr 1989 Sun Micro";
40 #endif
41 #endif
42 
43 /*
44  * check_bound.c
45  * Checks to see whether the program is still bound to the
46  * claimed address and returns the universal merged address
47  *
48  */
49 
50 #include <sys/types.h>
51 #include <sys/socket.h>
52 #include <rpc/rpc.h>
53 #include <stdio.h>
54 #include <netconfig.h>
55 #include <syslog.h>
56 #include <string.h>
57 #include <unistd.h>
58 #include <stdlib.h>
59 
60 #ifdef RPCBIND_RUMP
61 #include <rump/rump.h>
62 #include <rump/rump_syscalls.h>
63 #endif
64 
65 #include "rpcbind.h"
66 
67 struct fdlist {
68 	int fd;
69 	struct netconfig *nconf;
70 	struct fdlist *next;
71 	int check_binding;
72 };
73 
74 static struct fdlist *fdhead;	/* Link list of the check fd's */
75 static struct fdlist *fdtail;
76 static char nullstring[] = "";
77 
78 static bool_t check_bound(struct fdlist *, const char *uaddr);
79 
80 /*
81  * Returns 1 if the given address is bound for the given addr & transport
82  * For all error cases, we assume that the address is bound
83  * Returns 0 for success.
84  */
85 static bool_t
86 check_bound(struct fdlist *fdl, const char *uaddr)
87 {
88 	int fd;
89 	struct netbuf *na;
90 	int ans;
91 
92 	if (fdl->check_binding == FALSE)
93 		return (TRUE);
94 
95 	na = uaddr2taddr(fdl->nconf, uaddr);
96 	if (!na)
97 		return (TRUE); /* punt, should never happen */
98 
99 	fd = __rpc_nconf2fd(fdl->nconf);
100 	if (fd < 0) {
101 		free(na->buf);
102 		free(na);
103 		return (TRUE);
104 	}
105 
106 	ans = bind(fd, (struct sockaddr *)na->buf, na->len);
107 
108 #ifdef RPCBIND_RUMP
109 	rump_sys_close(fd);
110 #else
111 	close(fd);
112 #endif
113 	free(na->buf);
114 	free(na);
115 
116 	return (ans == 0 ? FALSE : TRUE);
117 }
118 
119 int
120 add_bndlist(struct netconfig *nconf, struct netbuf *baddr __unused)
121 {
122 	struct fdlist *fdl;
123 	struct netconfig *newnconf;
124 
125 	newnconf = getnetconfigent(nconf->nc_netid);
126 	if (newnconf == NULL)
127 		return (-1);
128 	fdl = malloc(sizeof(struct fdlist));
129 	if (fdl == NULL) {
130 		freenetconfigent(newnconf);
131 		syslog(LOG_ERR, "no memory!");
132 		return (-1);
133 	}
134 	fdl->nconf = newnconf;
135 	fdl->next = NULL;
136 	if (fdhead == NULL) {
137 		fdhead = fdl;
138 		fdtail = fdl;
139 	} else {
140 		fdtail->next = fdl;
141 		fdtail = fdl;
142 	}
143 	/* XXX no bound checking for now */
144 	fdl->check_binding = FALSE;
145 
146 	return 0;
147 }
148 
149 bool_t
150 is_bound(const char *netid, const char *uaddr)
151 {
152 	struct fdlist *fdl;
153 
154 	for (fdl = fdhead; fdl; fdl = fdl->next)
155 		if (strcmp(fdl->nconf->nc_netid, netid) == 0)
156 			break;
157 	if (fdl == NULL)
158 		return (TRUE);
159 	return (check_bound(fdl, uaddr));
160 }
161 
162 /*
163  * Returns NULL if there was some system error.
164  * Returns "" if the address was not bound, i.e the server crashed.
165  * Returns the merged address otherwise.
166  */
167 char *
168 mergeaddr(SVCXPRT *xprt, char *netid, char *uaddr, char *saddr)
169 {
170 	struct fdlist *fdl;
171 	char *c_uaddr, *s_uaddr, *m_uaddr, *allocated_uaddr = NULL;
172 
173 	for (fdl = fdhead; fdl; fdl = fdl->next)
174 		if (strcmp(fdl->nconf->nc_netid, netid) == 0)
175 			break;
176 	if (fdl == NULL)
177 		return (NULL);
178 	if (check_bound(fdl, uaddr) == FALSE)
179 		/* that server died */
180 		return nullstring;
181 	/*
182 	 * Try to determine the local address on which the client contacted us,
183 	 * so we can send a reply from the same address.  If it's unknown, then
184 	 * try to determine which address the client used, and pick a nearby
185 	 * local address.
186 	 *
187 	 * If saddr is not NULL, the remote client may have included the
188 	 * address by which it contacted us.  Use that for the "client" uaddr,
189 	 * otherwise use the info from the SVCXPRT.
190 	 */
191 	if (xprt->xp_rtaddr.buf != NULL) {
192 		c_uaddr = taddr2uaddr(fdl->nconf, &xprt->xp_rtaddr);
193 		allocated_uaddr = c_uaddr;
194 	} else if (saddr != NULL) {
195 		c_uaddr = saddr;
196 	} else {
197 		c_uaddr = taddr2uaddr(fdl->nconf, svc_getrpccaller(xprt));
198 		allocated_uaddr = c_uaddr;
199 	}
200 	if (c_uaddr == NULL) {
201 		syslog(LOG_ERR, "taddr2uaddr failed for %s",
202 			fdl->nconf->nc_netid);
203 		return (NULL);
204 	}
205 
206 #ifdef RPCBIND_DEBUG
207 	if (debugging) {
208 		if (saddr == NULL) {
209 			fprintf(stderr, "mergeaddr: client uaddr = %s\n",
210 			    c_uaddr);
211 		} else {
212 			fprintf(stderr, "mergeaddr: contact uaddr = %s\n",
213 			    c_uaddr);
214 		}
215 	}
216 #endif
217 	s_uaddr = uaddr;
218 	/*
219 	 * This is all we should need for IP 4 and 6
220 	 */
221 	m_uaddr = addrmerge(svc_getrpccaller(xprt), s_uaddr, c_uaddr, netid);
222 #ifdef RPCBIND_DEBUG
223 	if (debugging)
224 		fprintf(stderr, "mergeaddr: uaddr = %s, merged uaddr = %s\n",
225 				uaddr, m_uaddr);
226 #endif
227 	free(allocated_uaddr);
228 	return (m_uaddr);
229 }
230 
231 /*
232  * Returns a netconf structure from its internal list.  This
233  * structure should not be freed.
234  */
235 struct netconfig *
236 rpcbind_get_conf(const char *netid)
237 {
238 	struct fdlist *fdl;
239 
240 	for (fdl = fdhead; fdl; fdl = fdl->next)
241 		if (strcmp(fdl->nconf->nc_netid, netid) == 0)
242 			break;
243 	if (fdl == NULL)
244 		return (NULL);
245 	return (fdl->nconf);
246 }
247