xref: /openbsd/lib/libc/rpc/clnt_udp.c (revision e9b2b68c) 
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 1.6 1996/08/19 08:31:30 tholo 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 
119 	cl = (CLIENT *)mem_alloc(sizeof(CLIENT));
120 	if (cl == NULL) {
121 		(void) fprintf(stderr, "clntudp_create: out of memory\n");
122 		rpc_createerr.cf_stat = RPC_SYSTEMERROR;
123 		rpc_createerr.cf_error.re_errno = errno;
124 		goto fooy;
125 	}
126 	sendsz = ((sendsz + 3) / 4) * 4;
127 	recvsz = ((recvsz + 3) / 4) * 4;
128 	cu = (struct cu_data *)mem_alloc(sizeof(*cu) + sendsz + recvsz);
129 	if (cu == NULL) {
130 		(void) fprintf(stderr, "clntudp_create: out of memory\n");
131 		rpc_createerr.cf_stat = RPC_SYSTEMERROR;
132 		rpc_createerr.cf_error.re_errno = errno;
133 		goto fooy;
134 	}
135 	cu->cu_outbuf = &cu->cu_inbuf[recvsz];
136 
137 	(void)gettimeofday(&now, (struct timezone *)0);
138 	if (raddr->sin_port == 0) {
139 		u_short port;
140 		if ((port =
141 		    pmap_getport(raddr, program, version, IPPROTO_UDP)) == 0) {
142 			goto fooy;
143 		}
144 		raddr->sin_port = htons(port);
145 	}
146 	cl->cl_ops = &udp_ops;
147 	cl->cl_private = (caddr_t)cu;
148 	cu->cu_raddr = *raddr;
149 	cu->cu_rlen = sizeof (cu->cu_raddr);
150 	cu->cu_wait = wait;
151 	cu->cu_total.tv_sec = -1;
152 	cu->cu_total.tv_usec = -1;
153 	cu->cu_sendsz = sendsz;
154 	cu->cu_recvsz = recvsz;
155 	call_msg.rm_xid = getpid() ^ now.tv_sec ^ now.tv_usec;
156 	call_msg.rm_direction = CALL;
157 	call_msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
158 	call_msg.rm_call.cb_prog = program;
159 	call_msg.rm_call.cb_vers = version;
160 	xdrmem_create(&(cu->cu_outxdrs), cu->cu_outbuf,
161 	    sendsz, XDR_ENCODE);
162 	if (! xdr_callhdr(&(cu->cu_outxdrs), &call_msg)) {
163 		goto fooy;
164 	}
165 	cu->cu_xdrpos = XDR_GETPOS(&(cu->cu_outxdrs));
166 	if (*sockp < 0) {
167 		int dontblock = 1;
168 
169 		*sockp = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
170 		if (*sockp < 0) {
171 			rpc_createerr.cf_stat = RPC_SYSTEMERROR;
172 			rpc_createerr.cf_error.re_errno = errno;
173 			goto fooy;
174 		}
175 		/* attempt to bind to priv port */
176 		(void)bindresvport(*sockp, (struct sockaddr_in *)0);
177 		/* the sockets rpc controls are non-blocking */
178 		(void)ioctl(*sockp, FIONBIO, (char *) &dontblock);
179 		cu->cu_closeit = TRUE;
180 	} else {
181 		cu->cu_closeit = FALSE;
182 	}
183 	cu->cu_sock = *sockp;
184 	cl->cl_auth = authnone_create();
185 	return (cl);
186 fooy:
187 	if (cu)
188 		mem_free((caddr_t)cu, sizeof(*cu) + sendsz + recvsz);
189 	if (cl)
190 		mem_free((caddr_t)cl, sizeof(CLIENT));
191 	return ((CLIENT *)NULL);
192 }
193 
194 CLIENT *
195 clntudp_create(raddr, program, version, wait, sockp)
196 	struct sockaddr_in *raddr;
197 	u_long program;
198 	u_long version;
199 	struct timeval wait;
200 	register int *sockp;
201 {
202 
203 	return(clntudp_bufcreate(raddr, program, version, wait, sockp,
204 	    UDPMSGSIZE, UDPMSGSIZE));
205 }
206 
207 static enum clnt_stat
208 clntudp_call(cl, proc, xargs, argsp, xresults, resultsp, utimeout)
209 	register CLIENT	*cl;		/* client handle */
210 	u_long		proc;		/* procedure number */
211 	xdrproc_t	xargs;		/* xdr routine for args */
212 	caddr_t		argsp;		/* pointer to args */
213 	xdrproc_t	xresults;	/* xdr routine for results */
214 	caddr_t		resultsp;	/* pointer to results */
215 	struct timeval	utimeout;	/* seconds to wait before giving up */
216 {
217 	register struct cu_data *cu = (struct cu_data *)cl->cl_private;
218 	register XDR *xdrs;
219 	register int outlen;
220 	register int inlen;
221 	int fromlen;
222 	fd_set *fds, readfds;
223 	struct sockaddr_in from;
224 	struct rpc_msg reply_msg;
225 	XDR reply_xdrs;
226 	struct timeval time_waited, start, after, tmp1, tmp2;
227 	bool_t ok;
228 	int nrefreshes = 2;	/* number of times to refresh cred */
229 	struct timeval timeout;
230 
231 	if (cu->cu_total.tv_usec == -1)
232 		timeout = utimeout;     /* use supplied timeout */
233 	else
234 		timeout = cu->cu_total; /* use default timeout */
235 
236 	if (cu->cu_sock+1 > FD_SETSIZE) {
237 		fds = (fd_set *)malloc(howmany(cu->cu_sock+1, NBBY));
238 		if (fds == NULL)
239 			return (cu->cu_error.re_status = RPC_CANTSEND);
240 		memset(fds, '\0', howmany(cu->cu_sock+1, NBBY));
241 	} else {
242 		fds = &readfds;
243 		FD_ZERO(fds);
244 	}
245 
246 	timerclear(&time_waited);
247 call_again:
248 	xdrs = &(cu->cu_outxdrs);
249 	xdrs->x_op = XDR_ENCODE;
250 	XDR_SETPOS(xdrs, cu->cu_xdrpos);
251 	/*
252 	 * the transaction is the first thing in the out buffer
253 	 */
254 	(*(u_short *)(cu->cu_outbuf))++;
255 	if (!XDR_PUTLONG(xdrs, (long *)&proc) ||
256 	    !AUTH_MARSHALL(cl->cl_auth, xdrs) ||
257 	    !(*xargs)(xdrs, argsp)) {
258 		if (fds != &readfds)
259 			free(fds);
260 		return (cu->cu_error.re_status = RPC_CANTENCODEARGS);
261 	}
262 	outlen = (int)XDR_GETPOS(xdrs);
263 
264 send_again:
265 	if (sendto(cu->cu_sock, cu->cu_outbuf, outlen, 0,
266 	    (struct sockaddr *)&(cu->cu_raddr), cu->cu_rlen) != outlen) {
267 		cu->cu_error.re_errno = errno;
268 		if (fds != &readfds)
269 			free(fds);
270 		return (cu->cu_error.re_status = RPC_CANTSEND);
271 	}
272 
273 	/*
274 	 * Hack to provide rpc-based message passing
275 	 */
276 	if (!timerisset(&timeout)) {
277 		if (fds != &readfds)
278 			free(fds);
279 		return (cu->cu_error.re_status = RPC_TIMEDOUT);
280 	}
281 
282 	/*
283 	 * sub-optimal code appears here because we have
284 	 * some clock time to spare while the packets are in flight.
285 	 * (We assume that this is actually only executed once.)
286 	 */
287 	reply_msg.acpted_rply.ar_verf = _null_auth;
288 	reply_msg.acpted_rply.ar_results.where = resultsp;
289 	reply_msg.acpted_rply.ar_results.proc = xresults;
290 
291 	gettimeofday(&start, NULL);
292 	for (;;) {
293 		/* XXX we know the other bits are still clear */
294 		FD_SET(cu->cu_sock, fds);
295 		switch (select(cu->cu_sock+1, fds, NULL, NULL, &cu->cu_wait)) {
296 		case 0:
297 			timeradd(&time_waited, &cu->cu_wait, &tmp1);
298 			time_waited = tmp1;
299 			if (timercmp(&time_waited, &timeout, <))
300 				goto send_again;
301 			if (fds != &readfds)
302 				free(fds);
303 			return (cu->cu_error.re_status = RPC_TIMEDOUT);
304 		case -1:
305 			if (errno == EINTR) {
306 				gettimeofday(&after, NULL);
307 				timersub(&after, &start, &tmp1);
308 				timeradd(&time_waited, &tmp1, &tmp2);
309 				time_waited = tmp2;
310 				if (timercmp(&time_waited, &timeout, <))
311 					continue;
312 				if (fds != &readfds)
313 					free(fds);
314 				return (cu->cu_error.re_status = RPC_TIMEDOUT);
315 			}
316 			cu->cu_error.re_errno = errno;
317 			if (fds != &readfds)
318 				free(fds);
319 			return (cu->cu_error.re_status = RPC_CANTRECV);
320 		}
321 
322 		do {
323 			fromlen = sizeof(struct sockaddr);
324 			inlen = recvfrom(cu->cu_sock, cu->cu_inbuf,
325 			    (int) cu->cu_recvsz, 0,
326 			    (struct sockaddr *)&from, &fromlen);
327 		} while (inlen < 0 && errno == EINTR);
328 		if (inlen < 0) {
329 			if (errno == EWOULDBLOCK)
330 				continue;
331 			cu->cu_error.re_errno = errno;
332 			if (fds != &readfds)
333 				free(fds);
334 			return (cu->cu_error.re_status = RPC_CANTRECV);
335 		}
336 		if (inlen < sizeof(u_int32_t))
337 			continue;
338 		/* see if reply transaction id matches sent id */
339 		if (*((u_int32_t *)(cu->cu_inbuf)) != *((u_int32_t *)(cu->cu_outbuf)))
340 			continue;
341 		/* we now assume we have the proper reply */
342 		break;
343 	}
344 
345 	/*
346 	 * now decode and validate the response
347 	 */
348 	xdrmem_create(&reply_xdrs, cu->cu_inbuf, (u_int)inlen, XDR_DECODE);
349 	ok = xdr_replymsg(&reply_xdrs, &reply_msg);
350 	/* XDR_DESTROY(&reply_xdrs);  save a few cycles on noop destroy */
351 	if (ok) {
352 		_seterr_reply(&reply_msg, &(cu->cu_error));
353 		if (cu->cu_error.re_status == RPC_SUCCESS) {
354 			if (! AUTH_VALIDATE(cl->cl_auth,
355 			    &reply_msg.acpted_rply.ar_verf)) {
356 				cu->cu_error.re_status = RPC_AUTHERROR;
357 				cu->cu_error.re_why = AUTH_INVALIDRESP;
358 			}
359 			if (reply_msg.acpted_rply.ar_verf.oa_base != NULL) {
360 				xdrs->x_op = XDR_FREE;
361 				(void)xdr_opaque_auth(xdrs,
362 				    &(reply_msg.acpted_rply.ar_verf));
363 			}
364 		} else {
365 			/* maybe our credentials need to be refreshed ... */
366 			if (nrefreshes > 0 && AUTH_REFRESH(cl->cl_auth)) {
367 				nrefreshes--;
368 				goto call_again;
369 			}
370 		}
371 	} else
372 		cu->cu_error.re_status = RPC_CANTDECODERES;
373 
374 	if (fds != &readfds)
375 		free(fds);
376 	return (cu->cu_error.re_status);
377 }
378 
379 static void
380 clntudp_geterr(cl, errp)
381 	CLIENT *cl;
382 	struct rpc_err *errp;
383 {
384 	register struct cu_data *cu = (struct cu_data *)cl->cl_private;
385 
386 	*errp = cu->cu_error;
387 }
388 
389 
390 static bool_t
391 clntudp_freeres(cl, xdr_res, res_ptr)
392 	CLIENT *cl;
393 	xdrproc_t xdr_res;
394 	caddr_t res_ptr;
395 {
396 	register struct cu_data *cu = (struct cu_data *)cl->cl_private;
397 	register XDR *xdrs = &(cu->cu_outxdrs);
398 
399 	xdrs->x_op = XDR_FREE;
400 	return ((*xdr_res)(xdrs, res_ptr));
401 }
402 
403 static void
404 clntudp_abort(/*h*/)
405 	/*CLIENT *h;*/
406 {
407 }
408 
409 static bool_t
410 clntudp_control(cl, request, info)
411 	CLIENT *cl;
412 	int request;
413 	char *info;
414 {
415 	register struct cu_data *cu = (struct cu_data *)cl->cl_private;
416 
417 	switch (request) {
418 	case CLSET_TIMEOUT:
419 		cu->cu_total = *(struct timeval *)info;
420 		break;
421 	case CLGET_TIMEOUT:
422 		*(struct timeval *)info = cu->cu_total;
423 		break;
424 	case CLSET_RETRY_TIMEOUT:
425 		cu->cu_wait = *(struct timeval *)info;
426 		break;
427 	case CLGET_RETRY_TIMEOUT:
428 		*(struct timeval *)info = cu->cu_wait;
429 		break;
430 	case CLGET_SERVER_ADDR:
431 		*(struct sockaddr_in *)info = cu->cu_raddr;
432 		break;
433 	default:
434 		return (FALSE);
435 	}
436 	return (TRUE);
437 }
438 
439 static void
440 clntudp_destroy(cl)
441 	CLIENT *cl;
442 {
443 	register struct cu_data *cu = (struct cu_data *)cl->cl_private;
444 
445 	if (cu->cu_closeit) {
446 		(void)close(cu->cu_sock);
447 	}
448 	XDR_DESTROY(&(cu->cu_outxdrs));
449 	mem_free((caddr_t)cu, (sizeof(*cu) + cu->cu_sendsz + cu->cu_recvsz));
450 	mem_free((caddr_t)cl, sizeof(CLIENT));
451 }
452