xref: /freebsd/usr.sbin/ypbind/yp_ping.c (revision 59c8e88e72633afbc47a4ace0d2170d00d51f7dc)
1 /*
2  * SPDX-License-Identifier: BSD-4-Clause
3  *
4  * Copyright (c) 1996, 1997
5  *	Bill Paul <wpaul@ctr.columbia.edu>.  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 Bill Paul.
18  * 4. Neither the name of the author nor the names of any co-contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL Bill Paul OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 /*-
36  * Copyright (c) 2009, Sun Microsystems, Inc.
37  * All rights reserved.
38  *
39  * Redistribution and use in source and binary forms, with or without
40  * modification, are permitted provided that the following conditions are met:
41  * - Redistributions of source code must retain the above copyright notice,
42  *   this list of conditions and the following disclaimer.
43  * - Redistributions in binary form must reproduce the above copyright notice,
44  *   this list of conditions and the following disclaimer in the documentation
45  *   and/or other materials provided with the distribution.
46  * - Neither the name of Sun Microsystems, Inc. nor the names of its
47  *   contributors may be used to endorse or promote products derived
48  *   from this software without specific prior written permission.
49  *
50  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
51  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
52  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
53  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
54  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
55  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
56  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
57  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
58  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
59  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
60  * POSSIBILITY OF SUCH DAMAGE.
61  */
62 /*
63  * clnt_udp.c, Implements a UDP/IP based, client side RPC.
64  *
65  * Copyright (C) 1984, Sun Microsystems, Inc.
66  */
67 
68 #include <errno.h>
69 #include <netdb.h>
70 #include <stdio.h>
71 #include <stdlib.h>
72 #include <string.h>
73 #include <unistd.h>
74 #include <pthread.h>
75 #include <rpc/rpc.h>
76 #include <rpc/pmap_clnt.h>
77 #include <rpc/pmap_prot.h>
78 #include <rpcsvc/yp.h>
79 #include <sys/types.h>
80 #include <sys/poll.h>
81 #include <sys/socket.h>
82 #include <sys/signal.h>
83 #include <sys/ioctl.h>
84 #include <arpa/inet.h>
85 #include <net/if.h>
86 
87 #include "yp_ping.h"
88 
89 /*
90  * pmap_getport.c
91  * Client interface to pmap rpc service.
92  *
93  * Copyright (C) 1984, Sun Microsystems, Inc.
94  */
95 
96 
97 static struct timeval timeout = { 1, 0 };
98 static struct timeval tottimeout = { 1, 0 };
99 
100 /*
101  * Find the mapped port for program,version.
102  * Calls the pmap service remotely to do the lookup.
103  * Returns 0 if no map exists.
104  */
105 static u_short
106 __pmap_getport(struct sockaddr_in *address, u_long program, u_long version,
107     u_int protocol)
108 {
109 	u_short port = 0;
110 	int sock = -1;
111 	register CLIENT *client;
112 	struct pmap parms;
113 
114 	address->sin_port = htons(PMAPPORT);
115 
116 	client = clntudp_bufcreate(address, PMAPPROG,
117 	    PMAPVERS, timeout, &sock, RPCSMALLMSGSIZE, RPCSMALLMSGSIZE);
118 	if (client != (CLIENT *)NULL) {
119 		parms.pm_prog = program;
120 		parms.pm_vers = version;
121 		parms.pm_prot = protocol;
122 		parms.pm_port = 0;  /* not needed or used */
123 		if (CLNT_CALL(client, PMAPPROC_GETPORT,
124 			(xdrproc_t)xdr_pmap, &parms,
125 			(xdrproc_t)xdr_u_short, &port,
126 			tottimeout) != RPC_SUCCESS){
127 			rpc_createerr.cf_stat = RPC_PMAPFAILURE;
128 			clnt_geterr(client, &rpc_createerr.cf_error);
129 		} else if (port == 0) {
130 			rpc_createerr.cf_stat = RPC_PROGNOTREGISTERED;
131 		}
132 		CLNT_DESTROY(client);
133 	}
134 	if (sock != -1)
135 		(void)close(sock);
136 	address->sin_port = 0;
137 	return (port);
138 }
139 
140 /*
141  * Transmit to YPPROC_DOMAIN_NONACK, return immediately.
142  */
143 static bool_t *
144 ypproc_domain_nonack_2_send(domainname *argp, CLIENT *clnt)
145 {
146 	static bool_t clnt_res;
147 	struct timeval TIMEOUT = { 0, 0 };
148 
149 	memset((char *)&clnt_res, 0, sizeof (clnt_res));
150 	if (clnt_call(clnt, YPPROC_DOMAIN_NONACK,
151 		(xdrproc_t) xdr_domainname, (caddr_t) argp,
152 		(xdrproc_t) xdr_bool, (caddr_t) &clnt_res,
153 		TIMEOUT) != RPC_SUCCESS) {
154 		return (NULL);
155 	}
156 	return (&clnt_res);
157 }
158 
159 /*
160  * Receive response from YPPROC_DOMAIN_NONACK asynchronously.
161  */
162 static bool_t *
163 ypproc_domain_nonack_2_recv(domainname *argp, CLIENT *clnt)
164 {
165 	static bool_t clnt_res;
166 	struct timeval TIMEOUT = { 0, 0 };
167 
168 	memset((char *)&clnt_res, 0, sizeof (clnt_res));
169 	if (clnt_call(clnt, YPPROC_DOMAIN_NONACK,
170 		(xdrproc_t) NULL, (caddr_t) argp,
171 		(xdrproc_t) xdr_bool, (caddr_t) &clnt_res,
172 		TIMEOUT) != RPC_SUCCESS) {
173 		return (NULL);
174 	}
175 	return (&clnt_res);
176 }
177 
178 /*
179  * "We have the machine that goes 'ping!'" -- Monty Python
180  *
181  * This function blasts packets at the YPPROC_DOMAIN_NONACK procedures
182  * of the NIS servers listed in restricted_addrs structure.
183  * Whoever replies the fastest becomes our chosen server.
184  *
185  * Note: THIS IS NOT A BROADCAST OPERATION! We could use clnt_broadcast()
186  * for this, but that has the following problems:
187  * - We only get the address of the machine that replied in the
188  *   'eachresult' callback, and on multi-homed machines this can
189  *   lead to confusion.
190  * - clnt_broadcast() only transmits to local networks, whereas with
191  *   NIS+ you can have a perfectly good server located anywhere on or
192  *   off the local network.
193  * - clnt_broadcast() blocks for an arbitrary amount of time which the
194  *   caller can't control -- we want to avoid that.
195  *
196  * Also note that this has nothing to do with the NIS_PING procedure used
197  * for replica updates.
198  */
199 
200 struct ping_req {
201 	struct sockaddr_in	sin;
202 	u_int32_t		xid;
203 };
204 
205 int
206 __yp_ping(struct in_addr *restricted_addrs, int cnt, char *dom, short *port)
207 {
208 	struct timeval		tv = { 5, 0 };
209 	struct ping_req		**reqs;
210 	unsigned long		i;
211 	int			async;
212 	struct sockaddr_in	sin, *any = NULL;
213 	struct netbuf		addr;
214 	int			winner = -1;
215 	u_int32_t		xid_seed, xid_lookup;
216 	int			sock, dontblock = 1;
217 	CLIENT			*clnt;
218 	char			*foo = dom;
219 	int			validsrvs = 0;
220 
221 	/* Set up handles. */
222 	reqs = calloc(cnt, sizeof(struct ping_req *));
223 	xid_seed = time(NULL) ^ getpid();
224 
225 	for (i = 0; i < cnt; i++) {
226 		bzero((char *)&sin, sizeof(sin));
227 		sin.sin_family = AF_INET;
228 		bcopy((char *)&restricted_addrs[i],
229 			(char *)&sin.sin_addr, sizeof(struct in_addr));
230 		sin.sin_port = htons(__pmap_getport(&sin, YPPROG,
231 					YPVERS, IPPROTO_UDP));
232 		if (sin.sin_port == 0)
233 			continue;
234 		reqs[i] = calloc(1, sizeof(struct ping_req));
235 		bcopy((char *)&sin, (char *)&reqs[i]->sin, sizeof(sin));
236 		any = &reqs[i]->sin;
237 		reqs[i]->xid = xid_seed;
238 		xid_seed++;
239 		validsrvs++;
240 	}
241 
242 	/* Make sure at least one server was assigned */
243 	if (!validsrvs) {
244 		free(reqs);
245 		return(-1);
246 	}
247 
248 	/* Create RPC handle */
249 	sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
250 	clnt = clntudp_create(any, YPPROG, YPVERS, tv, &sock);
251 	if (clnt == NULL) {
252 		close(sock);
253 		for (i = 0; i < cnt; i++)
254 			if (reqs[i] != NULL)
255 				free(reqs[i]);
256 		free(reqs);
257 		return(-1);
258 	}
259 	clnt->cl_auth = authunix_create_default();
260 	tv.tv_sec = 0;
261 
262 	clnt_control(clnt, CLSET_TIMEOUT, (char *)&tv);
263 	async = TRUE;
264 	clnt_control(clnt, CLSET_ASYNC, (char *)&async);
265 	ioctl(sock, FIONBIO, &dontblock);
266 
267 	/* Transmit */
268 	for (i = 0; i < cnt; i++) {
269 		if (reqs[i] != NULL) {
270 			clnt_control(clnt, CLSET_XID, (char *)&reqs[i]->xid);
271 			addr.len = sizeof(reqs[i]->sin);
272 			addr.buf = (char *) &reqs[i]->sin;
273 			clnt_control(clnt, CLSET_SVC_ADDR, &addr);
274 			ypproc_domain_nonack_2_send(&foo, clnt);
275 		}
276 	}
277 
278 	/* Receive reply */
279 	ypproc_domain_nonack_2_recv(&foo, clnt);
280 
281 	/* Got a winner -- look him up. */
282 	clnt_control(clnt, CLGET_XID, (char *)&xid_lookup);
283 	for (i = 0; i < cnt; i++) {
284 		if (reqs[i] != NULL && reqs[i]->xid == xid_lookup) {
285 			winner = i;
286 			*port = reqs[i]->sin.sin_port;
287 		}
288 	}
289 
290 	/* Shut everything down */
291 	auth_destroy(clnt->cl_auth);
292 	clnt_destroy(clnt);
293 	close(sock);
294 
295 	for (i = 0; i < cnt; i++)
296 		if (reqs[i] != NULL)
297 			free(reqs[i]);
298 	free(reqs);
299 
300 	return(winner);
301 }
302