check_bound.c revision 296994 
1/*	$NetBSD: check_bound.c,v 1.2 2000/06/22 08:09:26 fvdl Exp $	*/
2/*	$FreeBSD: stable/10/usr.sbin/rpcbind/check_bound.c 296994 2016-03-17 20:00:49Z asomers $ */
3
4/*
5 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
6 * unrestricted use provided that this legend is included on all tape
7 * media and as a part of the software program in whole or part.  Users
8 * may copy or modify Sun RPC without charge, but are not authorized
9 * to license or distribute it to anyone else except as part of a product or
10 * program developed by the user.
11 *
12 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
13 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
14 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
15 *
16 * Sun RPC is provided with no support and without any obligation on the
17 * part of Sun Microsystems, Inc. to assist in its use, correction,
18 * modification or enhancement.
19 *
20 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
21 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
22 * OR ANY PART THEREOF.
23 *
24 * In no event will Sun Microsystems, Inc. be liable for any lost revenue
25 * or profits or other special, indirect and consequential damages, even if
26 * Sun has been advised of the possibility of such damages.
27 *
28 * Sun Microsystems, Inc.
29 * 2550 Garcia Avenue
30 * Mountain View, California  94043
31 */
32/*
33 * Copyright (c) 1986 - 1991 by Sun Microsystems, Inc.
34 */
35
36/* #ident	"@(#)check_bound.c	1.15	93/07/05 SMI" */
37
38#if 0
39#ifndef lint
40static	char sccsid[] = "@(#)check_bound.c 1.11 89/04/21 Copyr 1989 Sun Micro";
41#endif
42#endif
43
44/*
45 * check_bound.c
46 * Checks to see whether the program is still bound to the
47 * claimed address and returns the universal merged address
48 *
49 */
50
51#include <sys/types.h>
52#include <sys/socket.h>
53#include <rpc/rpc.h>
54#include <rpc/svc_dg.h>
55#include <stdio.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
64struct fdlist {
65	int fd;
66	struct netconfig *nconf;
67	struct fdlist *next;
68	int check_binding;
69};
70
71static struct fdlist *fdhead;	/* Link list of the check fd's */
72static struct fdlist *fdtail;
73static char *nullstring = "";
74
75static 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 */
82static bool_t
83check_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
112int
113add_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
142bool_t
143is_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 */
160char *
161mergeaddr(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	if (allocated_uaddr != NULL)
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