yplib.c revision 1.26 1 /* $NetBSD: yplib.c,v 1.26 1997/01/21 20:40:07 thorpej Exp $ */
2
3 /*
4 * Copyright (c) 1992, 1993 Theo de Raadt <deraadt (at) fsa.ca>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgement:
17 * This product includes software developed by Theo de Raadt.
18 * 4. The name of the author may not be used to endorse or promote products
19 * derived from this software without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
22 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
23 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
25 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 #if defined(LIBC_SCCS) && !defined(lint)
35 static char rcsid[] = "$NetBSD: yplib.c,v 1.26 1997/01/21 20:40:07 thorpej Exp $";
36 #endif
37
38 #include <sys/param.h>
39 #include <sys/types.h>
40 #include <sys/socket.h>
41 #include <sys/file.h>
42 #include <sys/uio.h>
43 #include <errno.h>
44 #include <stdio.h>
45 #include <stdlib.h>
46 #include <string.h>
47 #include <unistd.h>
48 #include <rpc/rpc.h>
49 #include <rpc/xdr.h>
50 #include <rpcsvc/yp_prot.h>
51 #include <rpcsvc/ypclnt.h>
52
53 #define BINDINGDIR "/var/yp/binding"
54 #define YPBINDLOCK "/var/run/ypbind.lock"
55
56 struct dom_binding *_ypbindlist;
57 char _yp_domain[MAXHOSTNAMELEN];
58
59 #define YPLIB_TIMEOUT 10
60 #define YPLIB_RPC_RETRIES 4
61
62 struct timeval _yplib_timeout = { YPLIB_TIMEOUT, 0 };
63 struct timeval _yplib_rpc_timeout = { YPLIB_TIMEOUT / YPLIB_RPC_RETRIES,
64 1000000 * (YPLIB_TIMEOUT % YPLIB_RPC_RETRIES) / YPLIB_RPC_RETRIES };
65 int _yplib_nerrs = 5;
66
67 void _yp_unbind __P((struct dom_binding *));
68
69 int
70 _yp_dobind(dom, ypdb)
71 const char *dom;
72 struct dom_binding **ypdb;
73 {
74 static int pid = -1;
75 char path[MAXPATHLEN];
76 struct dom_binding *ysd, *ysd2;
77 struct ypbind_resp ypbr;
78 struct sockaddr_in clnt_sin;
79 int clnt_sock, fd, gpid;
80 CLIENT *client;
81 int new = 0, r;
82 int nerrs = 0;
83
84 if (dom == NULL || *dom == 0)
85 return YPERR_BADARGS;
86
87 /*
88 * test if YP is running or not
89 */
90 if ((fd = open(YPBINDLOCK, O_RDONLY)) == -1)
91 return YPERR_YPBIND;
92 if (!(flock(fd, LOCK_EX | LOCK_NB) == -1 && errno == EWOULDBLOCK)) {
93 (void)close(fd);
94 return YPERR_YPBIND;
95 }
96 (void)close(fd);
97
98 gpid = getpid();
99 if (!(pid == -1 || pid == gpid)) {
100 ysd = _ypbindlist;
101 while (ysd) {
102 if (ysd->dom_client)
103 clnt_destroy(ysd->dom_client);
104 ysd2 = ysd->dom_pnext;
105 free(ysd);
106 ysd = ysd2;
107 }
108 _ypbindlist = NULL;
109 }
110 pid = gpid;
111
112 if (ypdb != NULL)
113 *ypdb = NULL;
114
115 for (ysd = _ypbindlist; ysd; ysd = ysd->dom_pnext)
116 if (strcmp(dom, ysd->dom_domain) == 0)
117 break;
118 if (ysd == NULL) {
119 if ((ysd = malloc(sizeof *ysd)) == NULL)
120 return YPERR_YPERR;
121 (void)memset(ysd, 0, sizeof *ysd);
122 ysd->dom_socket = -1;
123 ysd->dom_vers = 0;
124 new = 1;
125 }
126 again:
127 if (ysd->dom_vers == 0) {
128 (void) snprintf(path, sizeof(path), "%s/%s.%d",
129 BINDINGDIR, dom, 2);
130 if ((fd = open(path, O_RDONLY)) == -1) {
131 /*
132 * no binding file, YP is dead, or not yet fully
133 * alive.
134 */
135 goto trynet;
136 }
137 if (flock(fd, LOCK_EX | LOCK_NB) == -1 &&
138 errno == EWOULDBLOCK) {
139 struct iovec iov[2];
140 struct ypbind_resp ybr;
141 u_short ypb_port;
142 struct ypbind_binding *bn;
143
144 iov[0].iov_base = (caddr_t) & ypb_port;
145 iov[0].iov_len = sizeof ypb_port;
146 iov[1].iov_base = (caddr_t) & ybr;
147 iov[1].iov_len = sizeof ybr;
148
149 r = readv(fd, iov, 2);
150 if (r != iov[0].iov_len + iov[1].iov_len) {
151 (void)close(fd);
152 ysd->dom_vers = -1;
153 goto again;
154 }
155 (void)memset(&ysd->dom_server_addr, 0,
156 sizeof ysd->dom_server_addr);
157 ysd->dom_server_addr.sin_len =
158 sizeof(struct sockaddr_in);
159 ysd->dom_server_addr.sin_family = AF_INET;
160 bn = &ybr.ypbind_respbody.ypbind_bindinfo;
161 ysd->dom_server_addr.sin_port =
162 bn->ypbind_binding_port;
163
164 ysd->dom_server_addr.sin_addr =
165 bn->ypbind_binding_addr;
166
167 ysd->dom_server_port = ysd->dom_server_addr.sin_port;
168 (void)close(fd);
169 goto gotit;
170 } else {
171 /* no lock on binding file, YP is dead. */
172 (void)close(fd);
173 if (new)
174 free(ysd);
175 return YPERR_YPBIND;
176 }
177 }
178 trynet:
179 if (ysd->dom_vers == -1 || ysd->dom_vers == 0) {
180 struct ypbind_binding *bn;
181 (void)memset(&clnt_sin, 0, sizeof clnt_sin);
182 clnt_sin.sin_len = sizeof(struct sockaddr_in);
183 clnt_sin.sin_family = AF_INET;
184 clnt_sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
185
186 clnt_sock = RPC_ANYSOCK;
187 client = clnttcp_create(&clnt_sin, YPBINDPROG, YPBINDVERS,
188 &clnt_sock, 0, 0);
189 if (client == NULL) {
190 clnt_pcreateerror("clnttcp_create");
191 if (new)
192 free(ysd);
193 return YPERR_YPBIND;
194 }
195 r = clnt_call(client, YPBINDPROC_DOMAIN,
196 xdr_ypdomain_wrap_string, &dom, xdr_ypbind_resp,
197 &ypbr, _yplib_timeout);
198 if (r != RPC_SUCCESS) {
199 if (new == 0 && ++nerrs == _yplib_nerrs) {
200 nerrs = 0;
201 fprintf(stderr,
202 "YP server for domain %s not responding, still trying\n",
203 dom);
204 }
205 clnt_destroy(client);
206 ysd->dom_vers = -1;
207 goto again;
208 }
209 clnt_destroy(client);
210
211 (void)memset(&ysd->dom_server_addr, 0,
212 sizeof ysd->dom_server_addr);
213 ysd->dom_server_addr.sin_len = sizeof(struct sockaddr_in);
214 ysd->dom_server_addr.sin_family = AF_INET;
215 bn = &ypbr.ypbind_respbody.ypbind_bindinfo;
216 ysd->dom_server_addr.sin_port =
217 bn->ypbind_binding_port;
218 ysd->dom_server_addr.sin_addr.s_addr =
219 bn->ypbind_binding_addr.s_addr;
220 ysd->dom_server_port =
221 bn->ypbind_binding_port;
222 gotit:
223 ysd->dom_vers = YPVERS;
224 (void)strcpy(ysd->dom_domain, dom);
225 }
226 if (ysd->dom_client)
227 clnt_destroy(ysd->dom_client);
228 ysd->dom_socket = RPC_ANYSOCK;
229 ysd->dom_client = clntudp_create(&ysd->dom_server_addr,
230 YPPROG, YPVERS, _yplib_rpc_timeout, &ysd->dom_socket);
231 if (ysd->dom_client == NULL) {
232 clnt_pcreateerror("clntudp_create");
233 ysd->dom_vers = -1;
234 goto again;
235 }
236 if (fcntl(ysd->dom_socket, F_SETFD, 1) == -1)
237 perror("fcntl: F_SETFD");
238
239 if (new) {
240 ysd->dom_pnext = _ypbindlist;
241 _ypbindlist = ysd;
242 }
243 if (ypdb != NULL)
244 *ypdb = ysd;
245 return 0;
246 }
247
248 void
249 _yp_unbind(ypb)
250 struct dom_binding *ypb;
251 {
252 clnt_destroy(ypb->dom_client);
253 ypb->dom_client = NULL;
254 ypb->dom_socket = -1;
255 }
256
257 int
258 yp_bind(dom)
259 const char *dom;
260 {
261 return _yp_dobind(dom, NULL);
262 }
263
264 void
265 yp_unbind(dom)
266 const char *dom;
267 {
268 struct dom_binding *ypb, *ypbp;
269
270 ypbp = NULL;
271 for (ypb = _ypbindlist; ypb; ypb = ypb->dom_pnext) {
272 if (strcmp(dom, ypb->dom_domain) == 0) {
273 clnt_destroy(ypb->dom_client);
274 if (ypbp)
275 ypbp->dom_pnext = ypb->dom_pnext;
276 else
277 _ypbindlist = ypb->dom_pnext;
278 free(ypb);
279 return;
280 }
281 ypbp = ypb;
282 }
283 return;
284 }
285
286 int
287 yp_get_default_domain(domp)
288 char **domp;
289 {
290 *domp = NULL;
291 if (_yp_domain[0] == '\0')
292 if (getdomainname(_yp_domain, sizeof _yp_domain))
293 return YPERR_NODOM;
294 *domp = _yp_domain;
295 return 0;
296 }
297
298 int
299 _yp_check(dom)
300 char **dom;
301 {
302 char *unused;
303
304 if (_yp_domain[0] == '\0')
305 if (yp_get_default_domain(&unused))
306 return 0;
307
308 if (dom)
309 *dom = _yp_domain;
310
311 if (yp_bind(_yp_domain) == 0)
312 return 1;
313 return 0;
314 }
315