xref: /openbsd/lib/libc/rpc/pmap_rmt.c (revision 771fbea0)
1 /*	$OpenBSD: pmap_rmt.c,v 1.36 2020/12/30 18:56:35 benno Exp $ */
2 
3 /*
4  * Copyright (c) 2010, Oracle America, Inc.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions are
8  * met:
9  *
10  *     * Redistributions of source code must retain the above copyright
11  *       notice, this list of conditions and the following disclaimer.
12  *     * Redistributions in binary form must reproduce the above
13  *       copyright notice, this list of conditions and the following
14  *       disclaimer in the documentation and/or other materials
15  *       provided with the distribution.
16  *     * Neither the name of the "Oracle America, 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
21  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  *   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
24  *   COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
25  *   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  *   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
27  *   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28  *   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
29  *   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
30  *   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 /*
35  * pmap_rmt.c
36  * Client interface to pmap rpc service.
37  * remote call and broadcast service
38  */
39 
40 #include <rpc/rpc.h>
41 #include <rpc/pmap_prot.h>
42 #include <rpc/pmap_clnt.h>
43 #include <rpc/pmap_rmt.h>
44 #include <sys/socket.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <unistd.h>
48 #include <errno.h>
49 #include <string.h>
50 #include <net/if.h>
51 #include <sys/ioctl.h>
52 #include <arpa/inet.h>
53 #include <ifaddrs.h>
54 #define MAX_BROADCAST_SIZE 1400
55 
56 static struct timeval timeout = { 3, 0 };
57 
58 
59 /*
60  * pmapper remote-call-service interface.
61  * This routine is used to call the pmapper remote call service
62  * which will look up a service program in the port maps, and then
63  * remotely call that routine with the given parameters.  This allows
64  * programs to do a lookup and call in one step.
65 */
66 enum clnt_stat
67 pmap_rmtcall(struct sockaddr_in *addr, u_long prog, u_long vers, u_long proc,
68     xdrproc_t xdrargs, caddr_t argsp, xdrproc_t xdrres, caddr_t resp,
69     struct timeval tout, u_long *port_ptr)
70 {
71 	int sock = -1;
72 	CLIENT *client;
73 	struct rmtcallargs a;
74 	struct rmtcallres r;
75 	enum clnt_stat stat;
76 
77 	addr->sin_port = htons(PMAPPORT);
78 	client = clntudp_create(addr, PMAPPROG, PMAPVERS, timeout, &sock);
79 	if (client != NULL) {
80 		a.prog = prog;
81 		a.vers = vers;
82 		a.proc = proc;
83 		a.args_ptr = argsp;
84 		a.xdr_args = xdrargs;
85 		r.port_ptr = port_ptr;
86 		r.results_ptr = resp;
87 		r.xdr_results = xdrres;
88 		stat = CLNT_CALL(client, PMAPPROC_CALLIT, xdr_rmtcall_args, &a,
89 		    xdr_rmtcallres, &r, tout);
90 		CLNT_DESTROY(client);
91 	} else {
92 		stat = RPC_FAILED;
93 	}
94 	addr->sin_port = 0;
95 	return (stat);
96 }
97 
98 
99 /*
100  * XDR remote call arguments
101  * written for XDR_ENCODE direction only
102  */
103 bool_t
104 xdr_rmtcall_args(XDR *xdrs, struct rmtcallargs *cap)
105 {
106 	u_int lenposition, argposition, position;
107 
108 	if (xdr_u_long(xdrs, &(cap->prog)) &&
109 	    xdr_u_long(xdrs, &(cap->vers)) &&
110 	    xdr_u_long(xdrs, &(cap->proc))) {
111 		lenposition = XDR_GETPOS(xdrs);
112 		if (! xdr_u_long(xdrs, &(cap->arglen)))
113 		    return (FALSE);
114 		argposition = XDR_GETPOS(xdrs);
115 		if (! (*(cap->xdr_args))(xdrs, cap->args_ptr))
116 		    return (FALSE);
117 		position = XDR_GETPOS(xdrs);
118 		cap->arglen = (u_long)position - (u_long)argposition;
119 		XDR_SETPOS(xdrs, lenposition);
120 		if (! xdr_u_long(xdrs, &(cap->arglen)))
121 		    return (FALSE);
122 		XDR_SETPOS(xdrs, position);
123 		return (TRUE);
124 	}
125 	return (FALSE);
126 }
127 DEF_WEAK(xdr_rmtcall_args);
128 
129 /*
130  * XDR remote call results
131  * written for XDR_DECODE direction only
132  */
133 bool_t
134 xdr_rmtcallres(XDR *xdrs, struct rmtcallres *crp)
135 {
136 	caddr_t port_ptr;
137 
138 	port_ptr = (caddr_t)crp->port_ptr;
139 	if (xdr_reference(xdrs, &port_ptr, sizeof (u_long),
140 	    xdr_u_long) && xdr_u_long(xdrs, &crp->resultslen)) {
141 		crp->port_ptr = (u_long *)port_ptr;
142 		return ((*(crp->xdr_results))(xdrs, crp->results_ptr));
143 	}
144 	return (FALSE);
145 }
146 DEF_WEAK(xdr_rmtcallres);
147 
148 
149 /*
150  * The following is kludged-up support for simple rpc broadcasts.
151  * Someday a large, complicated system will replace these trivial
152  * routines which only support udp/ip .
153  */
154 static int
155 newgetbroadcastnets(struct in_addr **addrsp)
156 {
157 	struct ifaddrs *ifap, *ifa;
158 	struct sockaddr_in *sin;
159 	struct in_addr *addrs;
160 	int i = 0, n = 0;
161 
162 	if (getifaddrs(&ifap) != 0)
163 		return 0;
164 
165 	for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
166 		if (ifa->ifa_addr == NULL ||
167 		    ifa->ifa_addr->sa_family != AF_INET)
168 			continue;
169 		if ((ifa->ifa_flags & IFF_BROADCAST) &&
170 		    (ifa->ifa_flags & IFF_UP) &&
171 		    ifa->ifa_broadaddr &&
172 		    ifa->ifa_broadaddr->sa_family == AF_INET) {
173 			n++;
174 		}
175 	}
176 
177 	addrs = calloc(n, sizeof(*addrs));
178 	if (addrs == NULL) {
179 		freeifaddrs(ifap);
180 		return 0;
181 	}
182 
183 	for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
184 		if (ifa->ifa_addr == NULL ||
185 		    ifa->ifa_addr->sa_family != AF_INET)
186 			continue;
187 		if ((ifa->ifa_flags & IFF_BROADCAST) &&
188 		    (ifa->ifa_flags & IFF_UP) &&
189 		    ifa->ifa_broadaddr &&
190 		    ifa->ifa_broadaddr->sa_family == AF_INET) {
191 			sin = (struct sockaddr_in *)ifa->ifa_broadaddr;
192 			addrs[i++] = sin->sin_addr;
193 		}
194 	}
195 
196 	freeifaddrs(ifap);
197 	*addrsp = addrs;
198 	return i;
199 }
200 
201 typedef bool_t (*resultproc_t)(caddr_t, struct sockaddr_in *);
202 
203 enum clnt_stat
204 clnt_broadcast(u_long prog,	/* program number */
205     u_long vers,		/* version number */
206     u_long proc,		/* procedure number */
207     xdrproc_t xargs,		/* xdr routine for args */
208     caddr_t argsp,		/* pointer to args */
209     xdrproc_t xresults,		/* xdr routine for results */
210     caddr_t resultsp,		/* pointer to results */
211     resultproc_t eachresult)	/* call with each result obtained */
212 {
213 	enum clnt_stat stat;
214 	AUTH *unix_auth;
215 	XDR xdr_stream;
216 	XDR *xdrs = &xdr_stream;
217 	int outlen, inlen, nets;
218 	socklen_t fromlen;
219 	int sock = -1;
220 	int on = 1;
221 	struct pollfd pfd[1];
222 	int i;
223 	int timo;
224 	bool_t done = FALSE;
225 	u_long xid;
226 	u_long port;
227 	struct in_addr *addrs = NULL;
228 	struct sockaddr_in baddr, raddr; /* broadcast and response addresses */
229 	struct rmtcallargs a;
230 	struct rmtcallres r;
231 	struct rpc_msg msg;
232 	char outbuf[MAX_BROADCAST_SIZE], inbuf[UDPMSGSIZE];
233 
234 	if ((unix_auth = authunix_create_default()) == NULL) {
235 		stat = RPC_AUTHERROR;
236 		goto done_broad;
237 	}
238 
239 	/*
240 	 * initialization: create a socket, a broadcast address, and
241 	 * preserialize the arguments into a send buffer.
242 	 */
243 	if ((sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1) {
244 		stat = RPC_CANTSEND;
245 		goto done_broad;
246 	}
247 #ifdef SO_BROADCAST
248 	if (setsockopt(sock, SOL_SOCKET, SO_BROADCAST, &on, sizeof (on)) == -1) {
249 		stat = RPC_CANTSEND;
250 		goto done_broad;
251 	}
252 #endif /* def SO_BROADCAST */
253 
254 	pfd[0].fd = sock;
255 	pfd[0].events = POLLIN;
256 
257 	nets = newgetbroadcastnets(&addrs);
258 	if (nets == 0) {
259 		stat = RPC_CANTSEND;
260 		goto done_broad;
261 	}
262 
263 	memset(&baddr, 0, sizeof (baddr));
264 	baddr.sin_len = sizeof(struct sockaddr_in);
265 	baddr.sin_family = AF_INET;
266 	baddr.sin_port = htons(PMAPPORT);
267 	baddr.sin_addr.s_addr = htonl(INADDR_ANY);
268 	msg.rm_xid = xid = arc4random();
269 	msg.rm_direction = CALL;
270 	msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
271 	msg.rm_call.cb_prog = PMAPPROG;
272 	msg.rm_call.cb_vers = PMAPVERS;
273 	msg.rm_call.cb_proc = PMAPPROC_CALLIT;
274 	msg.rm_call.cb_cred = unix_auth->ah_cred;
275 	msg.rm_call.cb_verf = unix_auth->ah_verf;
276 	a.prog = prog;
277 	a.vers = vers;
278 	a.proc = proc;
279 	a.xdr_args = xargs;
280 	a.args_ptr = argsp;
281 	r.port_ptr = &port;
282 	r.xdr_results = xresults;
283 	r.results_ptr = resultsp;
284 	xdrmem_create(xdrs, outbuf, MAX_BROADCAST_SIZE, XDR_ENCODE);
285 	if (!xdr_callmsg(xdrs, &msg) || !xdr_rmtcall_args(xdrs, &a)) {
286 		stat = RPC_CANTENCODEARGS;
287 		goto done_broad;
288 	}
289 	outlen = (int)xdr_getpos(xdrs);
290 	xdr_destroy(xdrs);
291 
292 	/*
293 	 * Basic loop: broadcast a packet and wait a while for response(s).
294 	 * The response timeout grows larger per iteration.
295 	 *
296 	 * XXX This will loop about 5 times the stop. If there are
297 	 * lots of signals being received by the process it will quit
298 	 * send them all in one quick burst, not paying attention to
299 	 * the intended function of sending them slowly over half a
300 	 * minute or so
301 	 */
302 	for (timo = 4000; timo <= 14000; timo += 2000) {
303 		for (i = 0; i < nets; i++) {
304 			baddr.sin_addr = addrs[i];
305 			if (sendto(sock, outbuf, outlen, 0,
306 			    (struct sockaddr *)&baddr,
307 			    sizeof (struct sockaddr)) != outlen) {
308 				stat = RPC_CANTSEND;
309 				goto done_broad;
310 			}
311 		}
312 		if (eachresult == NULL) {
313 			stat = RPC_SUCCESS;
314 			goto done_broad;
315 		}
316 	recv_again:
317 		msg.acpted_rply.ar_verf = _null_auth;
318 		msg.acpted_rply.ar_results.where = (caddr_t)&r;
319 		msg.acpted_rply.ar_results.proc = xdr_rmtcallres;
320 
321 		switch (poll(pfd, 1, timo)) {
322 		case 0:  /* timed out */
323 			stat = RPC_TIMEDOUT;
324 			continue;
325 		case 1:
326 			if (pfd[0].revents & POLLNVAL)
327 				errno = EBADF;
328 			else if (pfd[0].revents & POLLERR)
329 				errno = EIO;
330 			else
331 				break;
332 			/* FALLTHROUGH */
333 		case -1:  /* some kind of error */
334 			if (errno == EINTR)
335 				goto recv_again;
336 			stat = RPC_CANTRECV;
337 			goto done_broad;
338 		}
339 	try_again:
340 		fromlen = sizeof(struct sockaddr);
341 		inlen = recvfrom(sock, inbuf, UDPMSGSIZE, 0,
342 		    (struct sockaddr *)&raddr, &fromlen);
343 		if (inlen == -1) {
344 			if (errno == EINTR)
345 				goto try_again;
346 			stat = RPC_CANTRECV;
347 			goto done_broad;
348 		}
349 		if (inlen < sizeof(u_int32_t))
350 			goto recv_again;
351 		/*
352 		 * see if reply transaction id matches sent id.
353 		 * If so, decode the results.
354 		 */
355 		xdrmem_create(xdrs, inbuf, (u_int)inlen, XDR_DECODE);
356 		if (xdr_replymsg(xdrs, &msg)) {
357 			if ((msg.rm_xid == xid) &&
358 			    (msg.rm_reply.rp_stat == MSG_ACCEPTED) &&
359 			    (msg.acpted_rply.ar_stat == SUCCESS)) {
360 				raddr.sin_port = htons((u_short)port);
361 				done = (*eachresult)(resultsp, &raddr);
362 			}
363 			/* otherwise, we just ignore the errors ... */
364 		}
365 		xdrs->x_op = XDR_FREE;
366 		msg.acpted_rply.ar_results.proc = xdr_void;
367 		(void)xdr_replymsg(xdrs, &msg);
368 		(void)(*xresults)(xdrs, resultsp);
369 		xdr_destroy(xdrs);
370 		if (done) {
371 			stat = RPC_SUCCESS;
372 			goto done_broad;
373 		} else {
374 			goto recv_again;
375 		}
376 	}
377 done_broad:
378 	free(addrs);
379 	if (sock >= 0)
380 		(void)close(sock);
381 	if (unix_auth != NULL)
382 		AUTH_DESTROY(unix_auth);
383 	return (stat);
384 }
385