1 /* $NetBSD: check_bound.c,v 1.9 2020/06/17 00:16:22 kamil 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_syscallshotgun.h>
63 #include <rump/rump_syscalls.h>
64 #endif
65
66 #include "rpcbind.h"
67
68 struct fdlist {
69 int fd;
70 struct netconfig *nconf;
71 struct fdlist *next;
72 int check_binding;
73 };
74
75 static struct fdlist *fdhead; /* Link list of the check fd's */
76 static struct fdlist *fdtail;
77 static char nullstring[] = "";
78
79 static bool_t check_bound(struct fdlist *, const char *uaddr);
80
81 /*
82 * Returns 1 if the given address is bound for the given addr & transport
83 * For all error cases, we assume that the address is bound
84 * Returns 0 for success.
85 */
86 static bool_t
check_bound(struct fdlist * fdl,const char * uaddr)87 check_bound(struct fdlist *fdl, const char *uaddr)
88 {
89 int fd;
90 struct netbuf *na;
91 int ans;
92
93 if (fdl->check_binding == FALSE)
94 return (TRUE);
95
96 na = uaddr2taddr(fdl->nconf, uaddr);
97 if (!na)
98 return (TRUE); /* punt, should never happen */
99
100 fd = __rpc_nconf2fd(fdl->nconf);
101 if (fd < 0) {
102 free(na->buf);
103 free(na);
104 return (TRUE);
105 }
106
107 ans = bind(fd, (struct sockaddr *)na->buf, na->len);
108
109 #ifdef RPCBIND_RUMP
110 rump_sys_close(fd);
111 #else
112 close(fd);
113 #endif
114 free(na->buf);
115 free(na);
116
117 return (ans == 0 ? FALSE : TRUE);
118 }
119
120 int
add_bndlist(struct netconfig * nconf,struct netbuf * baddr __unused)121 add_bndlist(struct netconfig *nconf, struct netbuf *baddr __unused)
122 {
123 struct fdlist *fdl;
124 struct netconfig *newnconf;
125
126 newnconf = getnetconfigent(nconf->nc_netid);
127 if (newnconf == NULL)
128 return (-1);
129 fdl = malloc(sizeof(*fdl));
130 if (fdl == NULL) {
131 freenetconfigent(newnconf);
132 syslog(LOG_ERR, "no memory!");
133 return (-1);
134 }
135 fdl->nconf = newnconf;
136 fdl->next = NULL;
137 if (fdhead == NULL) {
138 fdhead = fdl;
139 fdtail = fdl;
140 } else {
141 fdtail->next = fdl;
142 fdtail = fdl;
143 }
144 /* XXX no bound checking for now */
145 fdl->check_binding = FALSE;
146
147 return 0;
148 }
149
150 bool_t
is_bound(const char * netid,const char * uaddr)151 is_bound(const char *netid, const char *uaddr)
152 {
153 struct fdlist *fdl;
154
155 for (fdl = fdhead; fdl; fdl = fdl->next)
156 if (strcmp(fdl->nconf->nc_netid, netid) == 0)
157 break;
158 if (fdl == NULL)
159 return (TRUE);
160 return (check_bound(fdl, uaddr));
161 }
162
163 /*
164 * Returns NULL if there was some system error.
165 * Returns "" if the address was not bound, i.e the server crashed.
166 * Returns the merged address otherwise.
167 */
168 char *
mergeaddr(SVCXPRT * xprt,char * netid,char * uaddr,char * saddr)169 mergeaddr(SVCXPRT *xprt, char *netid, char *uaddr, char *saddr)
170 {
171 struct fdlist *fdl;
172 char *c_uaddr, *s_uaddr, *m_uaddr, *allocated_uaddr = NULL;
173
174 for (fdl = fdhead; fdl; fdl = fdl->next)
175 if (strcmp(fdl->nconf->nc_netid, netid) == 0)
176 break;
177 if (fdl == NULL)
178 return (NULL);
179 if (check_bound(fdl, uaddr) == FALSE)
180 /* that server died */
181 return nullstring;
182 /*
183 * Try to determine the local address on which the client contacted us,
184 * so we can send a reply from the same address. If it's unknown, then
185 * try to determine which address the client used, and pick a nearby
186 * local address.
187 *
188 * If saddr is not NULL, the remote client may have included the
189 * address by which it contacted us. Use that for the "client" uaddr,
190 * otherwise use the info from the SVCXPRT.
191 */
192 if (xprt->xp_rtaddr.buf != NULL) {
193 c_uaddr = taddr2uaddr(fdl->nconf, &xprt->xp_rtaddr);
194 allocated_uaddr = c_uaddr;
195 } else if (saddr != NULL) {
196 c_uaddr = saddr;
197 } else {
198 c_uaddr = taddr2uaddr(fdl->nconf, svc_getrpccaller(xprt));
199 allocated_uaddr = c_uaddr;
200 }
201 if (c_uaddr == NULL) {
202 syslog(LOG_ERR, "taddr2uaddr failed for %s",
203 fdl->nconf->nc_netid);
204 return (NULL);
205 }
206
207 #ifdef RPCBIND_DEBUG
208 if (debugging) {
209 if (saddr == NULL) {
210 fprintf(stderr, "mergeaddr: client uaddr = %s\n",
211 c_uaddr);
212 } else {
213 fprintf(stderr, "mergeaddr: contact uaddr = %s\n",
214 c_uaddr);
215 }
216 }
217 #endif
218 s_uaddr = uaddr;
219 /*
220 * This is all we should need for IP 4 and 6
221 */
222 m_uaddr = addrmerge(svc_getrpccaller(xprt), s_uaddr, c_uaddr, netid);
223 #ifdef RPCBIND_DEBUG
224 if (debugging)
225 fprintf(stderr, "mergeaddr: uaddr = %s, merged uaddr = %s\n",
226 uaddr, m_uaddr);
227 #endif
228 free(allocated_uaddr);
229 return (m_uaddr);
230 }
231
232 /*
233 * Returns a netconf structure from its internal list. This
234 * structure should not be freed.
235 */
236 struct netconfig *
rpcbind_get_conf(const char * netid)237 rpcbind_get_conf(const char *netid)
238 {
239 struct fdlist *fdl;
240
241 for (fdl = fdhead; fdl; fdl = fdl->next)
242 if (strcmp(fdl->nconf->nc_netid, netid) == 0)
243 break;
244 if (fdl == NULL)
245 return (NULL);
246 return (fdl->nconf);
247 }
248