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
55 struct fdlist {
56 int fd;
57 struct netconfig *nconf;
58 struct fdlist *next;
59 int check_binding;
60 };
61
62 static struct fdlist *fdhead; /* Link list of the check fd's */
63 static struct fdlist *fdtail;
64 static char *nullstring = "";
65
66 static 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 */
73 static bool_t
check_bound(struct fdlist * fdl,char * uaddr)74 check_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
103 int
add_bndlist(struct netconfig * nconf,struct netbuf * baddr __unused)104 add_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
133 bool_t
is_bound(char * netid,char * uaddr)134 is_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 */
151 char *
mergeaddr(SVCXPRT * xprt,char * netid,char * uaddr,char * saddr)152 mergeaddr(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 */
221 struct netconfig *
rpcbind_get_conf(const char * netid)222 rpcbind_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