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
46 #include <rpc/rpc.h>
47 #include <rpc/svc_dg.h>
48
49 #include <netconfig.h>
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <string.h>
53 #include <syslog.h>
54 #include <unistd.h>
55
56 #include "rpcbind.h"
57
58 struct fdlist {
59 int fd;
60 struct netconfig *nconf;
61 struct fdlist *next;
62 int check_binding;
63 };
64
65 static struct fdlist *fdhead; /* Link list of the check fd's */
66 static struct fdlist *fdtail;
67 static char nullstring[] = "";
68
69 static bool_t check_bound(struct fdlist *, const char *uaddr);
70
71 /*
72 * Returns 1 if the given address is bound for the given addr & transport
73 * For all error cases, we assume that the address is bound
74 * Returns 0 for success.
75 */
76 static bool_t
check_bound(struct fdlist * fdl,const char * uaddr)77 check_bound(struct fdlist *fdl, const char *uaddr)
78 {
79 int fd;
80 struct netbuf *na;
81 int ans;
82
83 if (fdl->check_binding == FALSE)
84 return (TRUE);
85
86 na = uaddr2taddr(fdl->nconf, uaddr);
87 if (!na)
88 return (TRUE); /* punt, should never happen */
89
90 fd = __rpc_nconf2fd(fdl->nconf);
91 if (fd < 0) {
92 free(na->buf);
93 free(na);
94 return (TRUE);
95 }
96
97 ans = bind(fd, (struct sockaddr *)na->buf, na->len);
98
99 close(fd);
100 free(na->buf);
101 free(na);
102
103 return (ans == 0 ? FALSE : TRUE);
104 }
105
106 int
add_bndlist(const struct netconfig * nconf,struct netbuf * baddr __unused)107 add_bndlist(const struct netconfig *nconf, struct netbuf *baddr __unused)
108 {
109 struct fdlist *fdl;
110 struct netconfig *newnconf;
111
112 newnconf = getnetconfigent(nconf->nc_netid);
113 if (newnconf == NULL)
114 return (-1);
115 fdl = malloc(sizeof(*fdl));
116 if (fdl == NULL) {
117 freenetconfigent(newnconf);
118 syslog(LOG_ERR, "no memory!");
119 return (-1);
120 }
121 fdl->nconf = newnconf;
122 fdl->next = NULL;
123 if (fdhead == NULL) {
124 fdhead = fdl;
125 fdtail = fdl;
126 } else {
127 fdtail->next = fdl;
128 fdtail = fdl;
129 }
130 /* XXX no bound checking for now */
131 fdl->check_binding = FALSE;
132
133 return 0;
134 }
135
136 bool_t
is_bound(const char * netid,const char * uaddr)137 is_bound(const char *netid, const char *uaddr)
138 {
139 struct fdlist *fdl;
140
141 for (fdl = fdhead; fdl; fdl = fdl->next)
142 if (strcmp(fdl->nconf->nc_netid, netid) == 0)
143 break;
144 if (fdl == NULL)
145 return (TRUE);
146 return (check_bound(fdl, uaddr));
147 }
148
149 /*
150 * Returns NULL if there was some system error.
151 * Returns "" if the address was not bound, i.e the server crashed.
152 * Returns the merged address otherwise.
153 */
154 char *
mergeaddr(SVCXPRT * xprt,char * netid,char * uaddr,char * saddr)155 mergeaddr(SVCXPRT *xprt, char *netid, char *uaddr, char *saddr)
156 {
157 struct fdlist *fdl;
158 struct netbuf *callee;
159 char *c_uaddr, *s_uaddr, *m_uaddr, *allocated_uaddr = NULL;
160
161 for (fdl = fdhead; fdl; fdl = fdl->next)
162 if (strcmp(fdl->nconf->nc_netid, netid) == 0)
163 break;
164 if (fdl == NULL)
165 return (NULL);
166 if (check_bound(fdl, uaddr) == FALSE)
167 /* that server died */
168 return (nullstring);
169 /*
170 * Try to determine the local address on which the client contacted us,
171 * so we can send a reply from the same address. If it's unknown, then
172 * try to determine which address the client used, and pick a nearby
173 * local address.
174 *
175 * If saddr is not NULL, the remote client may have included the
176 * address by which it contacted us. Use that for the "client" uaddr,
177 * otherwise use the info from the SVCXPRT.
178 */
179 callee = svc_getrpccallee(xprt);
180 if (callee != NULL && callee->buf != NULL) {
181 c_uaddr = taddr2uaddr(fdl->nconf, callee);
182 allocated_uaddr = c_uaddr;
183 } else if (saddr != NULL) {
184 c_uaddr = saddr;
185 } else {
186 c_uaddr = taddr2uaddr(fdl->nconf, svc_getrpccaller(xprt));
187 allocated_uaddr = c_uaddr;
188 }
189 if (c_uaddr == NULL) {
190 syslog(LOG_ERR, "taddr2uaddr failed for %s",
191 fdl->nconf->nc_netid);
192 return (NULL);
193 }
194
195 #ifdef RPCBIND_DEBUG
196 if (debugging) {
197 if (saddr == NULL) {
198 fprintf(stderr, "mergeaddr: client uaddr = %s\n",
199 c_uaddr);
200 } else {
201 fprintf(stderr, "mergeaddr: contact uaddr = %s\n",
202 c_uaddr);
203 }
204 }
205 #endif
206 s_uaddr = uaddr;
207 /*
208 * This is all we should need for IP 4 and 6
209 */
210 m_uaddr = addrmerge(svc_getrpccaller(xprt), s_uaddr, c_uaddr, netid);
211 #ifdef RPCBIND_DEBUG
212 if (debugging)
213 fprintf(stderr, "mergeaddr: uaddr = %s, merged uaddr = %s\n",
214 uaddr, m_uaddr);
215 #endif
216 free(allocated_uaddr);
217 return (m_uaddr);
218 }
219
220 /*
221 * Returns a netconf structure from its internal list. This
222 * structure should not be freed.
223 */
224 struct netconfig *
rpcbind_get_conf(const char * netid)225 rpcbind_get_conf(const char *netid)
226 {
227 struct fdlist *fdl;
228
229 for (fdl = fdhead; fdl; fdl = fdl->next)
230 if (strcmp(fdl->nconf->nc_netid, netid) == 0)
231 break;
232 if (fdl == NULL)
233 return (NULL);
234 return (fdl->nconf);
235 }
236