xref: /openbsd/lib/libc/rpc/clnt_udp.c (revision 52091252)
1 /*
2  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
3  * unrestricted use provided that this legend is included on all tape
4  * media and as a part of the software program in whole or part.  Users
5  * may copy or modify Sun RPC without charge, but are not authorized
6  * to license or distribute it to anyone else except as part of a product or
7  * program developed by the user.
8  *
9  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
10  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
11  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
12  *
13  * Sun RPC is provided with no support and without any obligation on the
14  * part of Sun Microsystems, Inc. to assist in its use, correction,
15  * modification or enhancement.
16  *
17  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
18  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
19  * OR ANY PART THEREOF.
20  *
21  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
22  * or profits or other special, indirect and consequential damages, even if
23  * Sun has been advised of the possibility of such damages.
24  *
25  * Sun Microsystems, Inc.
26  * 2550 Garcia Avenue
27  * Mountain View, California  94043
28  */
29 
30 #if defined(LIBC_SCCS) && !defined(lint)
31 static char *rcsid = "$OpenBSD: clnt_udp.c,v 1.9 1996/11/14 06:51:48 etheisen Exp $";
32 #endif /* LIBC_SCCS and not lint */
33 
34 /*
35  * clnt_udp.c, Implements a UDP/IP based, client side RPC.
36  *
37  * Copyright (C) 1984, Sun Microsystems, Inc.
38  */
39 
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <unistd.h>
43 #include <rpc/rpc.h>
44 #include <sys/socket.h>
45 #include <sys/ioctl.h>
46 #include <netdb.h>
47 #include <errno.h>
48 #include <rpc/pmap_clnt.h>
49 
50 /*
51  * UDP bases client side rpc operations
52  */
53 static enum clnt_stat	clntudp_call();
54 static void		clntudp_abort();
55 static void		clntudp_geterr();
56 static bool_t		clntudp_freeres();
57 static bool_t           clntudp_control();
58 static void		clntudp_destroy();
59 
60 static struct clnt_ops udp_ops = {
61 	clntudp_call,
62 	clntudp_abort,
63 	clntudp_geterr,
64 	clntudp_freeres,
65 	clntudp_destroy,
66 	clntudp_control
67 };
68 
69 /*
70  * Private data kept per client handle
71  */
72 struct cu_data {
73 	int		   cu_sock;
74 	bool_t		   cu_closeit;
75 	struct sockaddr_in cu_raddr;
76 	int		   cu_rlen;
77 	struct timeval	   cu_wait;
78 	struct timeval     cu_total;
79 	struct rpc_err	   cu_error;
80 	XDR		   cu_outxdrs;
81 	u_int		   cu_xdrpos;
82 	u_int		   cu_sendsz;
83 	char		   *cu_outbuf;
84 	u_int		   cu_recvsz;
85 	char		   cu_inbuf[1];
86 };
87 
88 /*
89  * Create a UDP based client handle.
90  * If *sockp<0, *sockp is set to a newly created UPD socket.
91  * If raddr->sin_port is 0 a binder on the remote machine
92  * is consulted for the correct port number.
93  * NB: It is the clients responsibility to close *sockp.
94  * NB: The rpch->cl_auth is initialized to null authentication.
95  *     Caller may wish to set this something more useful.
96  *
97  * wait is the amount of time used between retransmitting a call if
98  * no response has been heard;  retransmition occurs until the actual
99  * rpc call times out.
100  *
101  * sendsz and recvsz are the maximum allowable packet sizes that can be
102  * sent and received.
103  */
104 CLIENT *
105 clntudp_bufcreate(raddr, program, version, wait, sockp, sendsz, recvsz)
106 	struct sockaddr_in *raddr;
107 	u_long program;
108 	u_long version;
109 	struct timeval wait;
110 	register int *sockp;
111 	u_int sendsz;
112 	u_int recvsz;
113 {
114 	CLIENT *cl;
115 	register struct cu_data *cu;
116 	struct timeval now;
117 	struct rpc_msg call_msg;
118 	static u_int32_t disrupt;
119 
120 	if (disrupt == 0)
121 		disrupt = (u_int32_t)(long)raddr;
122 
123 	cl = (CLIENT *)mem_alloc(sizeof(CLIENT));
124 	if (cl == NULL) {
125 		(void) fprintf(stderr, "clntudp_create: out of memory\n");
126 		rpc_createerr.cf_stat = RPC_SYSTEMERROR;
127 		rpc_createerr.cf_error.re_errno = errno;
128 		goto fooy;
129 	}
130 	sendsz = ((sendsz + 3) / 4) * 4;
131 	recvsz = ((recvsz + 3) / 4) * 4;
132 	cu = (struct cu_data *)mem_alloc(sizeof(*cu) + sendsz + recvsz);
133 	if (cu == NULL) {
134 		(void) fprintf(stderr, "clntudp_create: out of memory\n");
135 		rpc_createerr.cf_stat = RPC_SYSTEMERROR;
136 		rpc_createerr.cf_error.re_errno = errno;
137 		goto fooy;
138 	}
139 	cu->cu_outbuf = &cu->cu_inbuf[recvsz];
140 
141 	(void)gettimeofday(&now, (struct timezone *)0);
142 	if (raddr->sin_port == 0) {
143 		u_short port;
144 		if ((port =
145 		    pmap_getport(raddr, program, version, IPPROTO_UDP)) == 0) {
146 			goto fooy;
147 		}
148 		raddr->sin_port = htons(port);
149 	}
150 	cl->cl_ops = &udp_ops;
151 	cl->cl_private = (caddr_t)cu;
152 	cu->cu_raddr = *raddr;
153 	cu->cu_rlen = sizeof (cu->cu_raddr);
154 	cu->cu_wait = wait;
155 	cu->cu_total.tv_sec = -1;
156 	cu->cu_total.tv_usec = -1;
157 	cu->cu_sendsz = sendsz;
158 	cu->cu_recvsz = recvsz;
159 	call_msg.rm_xid = (++disrupt) ^ getpid() ^ now.tv_sec ^ now.tv_usec;
160 	call_msg.rm_direction = CALL;
161 	call_msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
162 	call_msg.rm_call.cb_prog = program;
163 	call_msg.rm_call.cb_vers = version;
164 	xdrmem_create(&(cu->cu_outxdrs), cu->cu_outbuf,
165 	    sendsz, XDR_ENCODE);
166 	if (! xdr_callhdr(&(cu->cu_outxdrs), &call_msg)) {
167 		goto fooy;
168 	}
169 	cu->cu_xdrpos = XDR_GETPOS(&(cu->cu_outxdrs));
170 	if (*sockp < 0) {
171 		int dontblock = 1;
172 
173 		*sockp = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
174 		if (*sockp < 0) {
175 			rpc_createerr.cf_stat = RPC_SYSTEMERROR;
176 			rpc_createerr.cf_error.re_errno = errno;
177 			goto fooy;
178 		}
179 		/* attempt to bind to priv port */
180 		(void)bindresvport(*sockp, (struct sockaddr_in *)0);
181 		/* the sockets rpc controls are non-blocking */
182 		(void)ioctl(*sockp, FIONBIO, (char *) &dontblock);
183 		cu->cu_closeit = TRUE;
184 	} else {
185 		cu->cu_closeit = FALSE;
186 	}
187 	cu->cu_sock = *sockp;
188 	cl->cl_auth = authnone_create();
189 	return (cl);
190 fooy:
191 	if (cu)
192 		mem_free((caddr_t)cu, sizeof(*cu) + sendsz + recvsz);
193 	if (cl)
194 		mem_free((caddr_t)cl, sizeof(CLIENT));
195 	return ((CLIENT *)NULL);
196 }
197 
198 CLIENT *
199 clntudp_create(raddr, program, version, wait, sockp)
200 	struct sockaddr_in *raddr;
201 	u_long program;
202 	u_long version;
203 	struct timeval wait;
204 	register int *sockp;
205 {
206 
207 	return(clntudp_bufcreate(raddr, program, version, wait, sockp,
208 	    UDPMSGSIZE, UDPMSGSIZE));
209 }
210 
211 static enum clnt_stat
212 clntudp_call(cl, proc, xargs, argsp, xresults, resultsp, utimeout)
213 	register CLIENT	*cl;		/* client handle */
214 	u_long		proc;		/* procedure number */
215 	xdrproc_t	xargs;		/* xdr routine for args */
216 	caddr_t		argsp;		/* pointer to args */
217 	xdrproc_t	xresults;	/* xdr routine for results */
218 	caddr_t		resultsp;	/* pointer to results */
219 	struct timeval	utimeout;	/* seconds to wait before giving up */
220 {
221 	register struct cu_data *cu = (struct cu_data *)cl->cl_private;
222 	register XDR *xdrs;
223 	register int outlen;
224 	register int inlen;
225 	int fromlen;
226 	fd_set *fds, readfds;
227 	struct sockaddr_in from;
228 	struct rpc_msg reply_msg;
229 	XDR reply_xdrs;
230 	struct timeval time_waited, start, after, tmp1, tmp2;
231 	bool_t ok;
232 	int nrefreshes = 2;	/* number of times to refresh cred */
233 	struct timeval timeout;
234 
235 	if (cu->cu_total.tv_usec == -1)
236 		timeout = utimeout;     /* use supplied timeout */
237 	else
238 		timeout = cu->cu_total; /* use default timeout */
239 
240 	if (cu->cu_sock+1 > FD_SETSIZE) {
241 		int bytes = howmany(cu->cu_sock+1, NFDBITS) * sizeof(fd_mask);
242 		fds = (fd_set *)malloc(bytes);
243 		if (fds == NULL)
244 			return (cu->cu_error.re_status = RPC_CANTSEND);
245 		memset(fds, 0, bytes);
246 	} else {
247 		fds = &readfds;
248 		FD_ZERO(fds);
249 	}
250 
251 	timerclear(&time_waited);
252 call_again:
253 	xdrs = &(cu->cu_outxdrs);
254 	xdrs->x_op = XDR_ENCODE;
255 	XDR_SETPOS(xdrs, cu->cu_xdrpos);
256 	/*
257 	 * the transaction is the first thing in the out buffer
258 	 */
259 	(*(u_short *)(cu->cu_outbuf))++;
260 	if (!XDR_PUTLONG(xdrs, (long *)&proc) ||
261 	    !AUTH_MARSHALL(cl->cl_auth, xdrs) ||
262 	    !(*xargs)(xdrs, argsp)) {
263 		if (fds != &readfds)
264 			free(fds);
265 		return (cu->cu_error.re_status = RPC_CANTENCODEARGS);
266 	}
267 	outlen = (int)XDR_GETPOS(xdrs);
268 
269 send_again:
270 	if (sendto(cu->cu_sock, cu->cu_outbuf, outlen, 0,
271 	    (struct sockaddr *)&(cu->cu_raddr), cu->cu_rlen) != outlen) {
272 		cu->cu_error.re_errno = errno;
273 		if (fds != &readfds)
274 			free(fds);
275 		return (cu->cu_error.re_status = RPC_CANTSEND);
276 	}
277 
278 	/*
279 	 * Hack to provide rpc-based message passing
280 	 */
281 	if (!timerisset(&timeout)) {
282 		if (fds != &readfds)
283 			free(fds);
284 		return (cu->cu_error.re_status = RPC_TIMEDOUT);
285 	}
286 
287 	/*
288 	 * sub-optimal code appears here because we have
289 	 * some clock time to spare while the packets are in flight.
290 	 * (We assume that this is actually only executed once.)
291 	 */
292 	reply_msg.acpted_rply.ar_verf = _null_auth;
293 	reply_msg.acpted_rply.ar_results.where = resultsp;
294 	reply_msg.acpted_rply.ar_results.proc = xresults;
295 
296 	gettimeofday(&start, NULL);
297 	for (;;) {
298 		/* XXX we know the other bits are still clear */
299 		FD_SET(cu->cu_sock, fds);
300 		switch (select(cu->cu_sock+1, fds, NULL, NULL, &cu->cu_wait)) {
301 		case 0:
302 			timeradd(&time_waited, &cu->cu_wait, &tmp1);
303 			time_waited = tmp1;
304 			if (timercmp(&time_waited, &timeout, <))
305 				goto send_again;
306 			if (fds != &readfds)
307 				free(fds);
308 			return (cu->cu_error.re_status = RPC_TIMEDOUT);
309 		case -1:
310 			if (errno == EINTR) {
311 				gettimeofday(&after, NULL);
312 				timersub(&after, &start, &tmp1);
313 				timeradd(&time_waited, &tmp1, &tmp2);
314 				time_waited = tmp2;
315 				if (timercmp(&time_waited, &timeout, <))
316 					continue;
317 				if (fds != &readfds)
318 					free(fds);
319 				return (cu->cu_error.re_status = RPC_TIMEDOUT);
320 			}
321 			cu->cu_error.re_errno = errno;
322 			if (fds != &readfds)
323 				free(fds);
324 			return (cu->cu_error.re_status = RPC_CANTRECV);
325 		}
326 
327 		do {
328 			fromlen = sizeof(struct sockaddr);
329 			inlen = recvfrom(cu->cu_sock, cu->cu_inbuf,
330 			    (int) cu->cu_recvsz, 0,
331 			    (struct sockaddr *)&from, &fromlen);
332 		} while (inlen < 0 && errno == EINTR);
333 		if (inlen < 0) {
334 			if (errno == EWOULDBLOCK)
335 				continue;
336 			cu->cu_error.re_errno = errno;
337 			if (fds != &readfds)
338 				free(fds);
339 			return (cu->cu_error.re_status = RPC_CANTRECV);
340 		}
341 		if (inlen < sizeof(u_int32_t))
342 			continue;
343 		/* see if reply transaction id matches sent id */
344 		if (*((u_int32_t *)(cu->cu_inbuf)) != *((u_int32_t *)(cu->cu_outbuf)))
345 			continue;
346 		/* we now assume we have the proper reply */
347 		break;
348 	}
349 
350 	/*
351 	 * now decode and validate the response
352 	 */
353 	xdrmem_create(&reply_xdrs, cu->cu_inbuf, (u_int)inlen, XDR_DECODE);
354 	ok = xdr_replymsg(&reply_xdrs, &reply_msg);
355 	/* XDR_DESTROY(&reply_xdrs);  save a few cycles on noop destroy */
356 	if (ok) {
357 		_seterr_reply(&reply_msg, &(cu->cu_error));
358 		if (cu->cu_error.re_status == RPC_SUCCESS) {
359 			if (! AUTH_VALIDATE(cl->cl_auth,
360 			    &reply_msg.acpted_rply.ar_verf)) {
361 				cu->cu_error.re_status = RPC_AUTHERROR;
362 				cu->cu_error.re_why = AUTH_INVALIDRESP;
363 			}
364 			if (reply_msg.acpted_rply.ar_verf.oa_base != NULL) {
365 				xdrs->x_op = XDR_FREE;
366 				(void)xdr_opaque_auth(xdrs,
367 				    &(reply_msg.acpted_rply.ar_verf));
368 			}
369 		} else {
370 			/* maybe our credentials need to be refreshed ... */
371 			if (nrefreshes > 0 && AUTH_REFRESH(cl->cl_auth)) {
372 				nrefreshes--;
373 				goto call_again;
374 			}
375 		}
376 	} else
377 		cu->cu_error.re_status = RPC_CANTDECODERES;
378 
379 	if (fds != &readfds)
380 		free(fds);
381 	return (cu->cu_error.re_status);
382 }
383 
384 static void
385 clntudp_geterr(cl, errp)
386 	CLIENT *cl;
387 	struct rpc_err *errp;
388 {
389 	register struct cu_data *cu = (struct cu_data *)cl->cl_private;
390 
391 	*errp = cu->cu_error;
392 }
393 
394 
395 static bool_t
396 clntudp_freeres(cl, xdr_res, res_ptr)
397 	CLIENT *cl;
398 	xdrproc_t xdr_res;
399 	caddr_t res_ptr;
400 {
401 	register struct cu_data *cu = (struct cu_data *)cl->cl_private;
402 	register XDR *xdrs = &(cu->cu_outxdrs);
403 
404 	xdrs->x_op = XDR_FREE;
405 	return ((*xdr_res)(xdrs, res_ptr));
406 }
407 
408 static void
409 clntudp_abort(/*h*/)
410 	/*CLIENT *h;*/
411 {
412 }
413 
414 static bool_t
415 clntudp_control(cl, request, info)
416 	CLIENT *cl;
417 	int request;
418 	char *info;
419 {
420 	register struct cu_data *cu = (struct cu_data *)cl->cl_private;
421 
422 	switch (request) {
423 	case CLSET_TIMEOUT:
424 		cu->cu_total = *(struct timeval *)info;
425 		break;
426 	case CLGET_TIMEOUT:
427 		*(struct timeval *)info = cu->cu_total;
428 		break;
429 	case CLSET_RETRY_TIMEOUT:
430 		cu->cu_wait = *(struct timeval *)info;
431 		break;
432 	case CLGET_RETRY_TIMEOUT:
433 		*(struct timeval *)info = cu->cu_wait;
434 		break;
435 	case CLGET_SERVER_ADDR:
436 		*(struct sockaddr_in *)info = cu->cu_raddr;
437 		break;
438 	default:
439 		return (FALSE);
440 	}
441 	return (TRUE);
442 }
443 
444 static void
445 clntudp_destroy(cl)
446 	CLIENT *cl;
447 {
448 	register struct cu_data *cu = (struct cu_data *)cl->cl_private;
449 
450 	if (cu->cu_closeit) {
451 		(void)close(cu->cu_sock);
452 	}
453 	XDR_DESTROY(&(cu->cu_outxdrs));
454 	mem_free((caddr_t)cu, (sizeof(*cu) + cu->cu_sendsz + cu->cu_recvsz));
455 	mem_free((caddr_t)cl, sizeof(CLIENT));
456 }
457