xref: /illumos-gate/usr/src/ucblib/librpcsoc/clnt_udp.c (revision f37b3cbb6f67aaea5eec1c335bdc7bf432867d64)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*
28  * Copyright (c) 1984, 1986, 1987, 1988, 1989, 1996 AT&T
29  * All Rights Reserved
30  */
31 
32 /*
33  * University Copyright- Copyright (c) 1982, 1986, 1988
34  * The Regents of the University of California
35  * All Rights Reserved
36  *
37  * University Acknowledgment- Portions of this document are derived from
38  * software developed by the University of California, Berkeley, and its
39  * contributors.
40  */
41 
42 /*
43  * clnt_udp.c, Implements a UDP/IP based, client side RPC.
44  */
45 
46 #include <rpc/rpc.h>
47 #include <sys/socket.h>
48 #include <sys/time.h>
49 #include <sys/ioctl.h>
50 #include <netdb.h>
51 #include <errno.h>
52 #include <rpc/pmap_clnt.h>
53 #include <rpc/clnt_soc.h>
54 #include <syslog.h>
55 #include <sys/filio.h>
56 #include <malloc.h>
57 #include <unistd.h>
58 #include <stropts.h>
59 #include <stdio.h>
60 
61 
62 extern int errno;
63 
64 extern int _socket(int, int, int);
65 extern pid_t getpid();
66 extern int bindresvport(int, struct sockaddr_in *);
67 extern bool_t   xdr_opaque_auth(XDR *, struct opaque_auth *);
68 extern int _sendto(int, const char *, int, int,
69 	const struct sockaddr *, int);
70 extern int _recvfrom(int, char *, int, int,
71 	struct sockaddr *, int *);
72 
73 
74 static struct clnt_ops *clntudp_ops();
75 
76 /*
77  * Private data kept per client handle
78  */
79 struct cu_data {
80 	int		   cu_sock;
81 	bool_t		   cu_closeit;
82 	struct sockaddr_in cu_raddr;
83 	int		   cu_rlen;
84 	struct timeval	   cu_wait;
85 	struct timeval	   cu_total;
86 	struct rpc_err	   cu_error;
87 	XDR		   cu_outxdrs;
88 	u_int		   cu_xdrpos;
89 	u_int		   cu_sendsz;
90 	char		   *cu_outbuf;
91 	u_int		   cu_recvsz;
92 	char		   cu_inbuf[1];
93 };
94 
95 /*
96  * Create a UDP based client handle.
97  * If *sockp<0, *sockp is set to a newly created UPD socket.
98  * If raddr->sin_port is 0 a binder on the remote machine
99  * is consulted for the correct port number.
100  * NB: It is the clients responsibility to close *sockp.
101  * NB: The rpch->cl_auth is initialized to null authentication.
102  *	Caller may wish to set this something more useful.
103  *
104  * wait is the amount of time used between retransmitting a call if
105  * no response has been heard;  retransmition occurs until the actual
106  * rpc call times out.
107  *
108  * sendsz and recvsz are the maximum allowable packet sizes that can be
109  * sent and received.
110  */
111 CLIENT *
112 clntudp_bufcreate(raddr, program, version, wait, sockp, sendsz, recvsz)
113 	struct sockaddr_in *raddr;
114 	rpcprog_t program;
115 	rpcvers_t version;
116 	struct timeval wait;
117 	register int *sockp;
118 	u_int sendsz;
119 	u_int recvsz;
120 {
121 	CLIENT *cl;
122 	register struct cu_data *cu;
123 	struct timeval now;
124 	struct rpc_msg call_msg;
125 
126 	cl = (CLIENT *)mem_alloc(sizeof (CLIENT));
127 	if (cl == NULL) {
128 		(void) syslog(LOG_ERR, "clntudp_create: out of memory");
129 		rpc_createerr.cf_stat = RPC_SYSTEMERROR;
130 		rpc_createerr.cf_error.re_errno = errno;
131 		goto fooy;
132 	}
133 	sendsz = ((sendsz + 3) / 4) * 4;
134 	recvsz = ((recvsz + 3) / 4) * 4;
135 	cu = (struct cu_data *)mem_alloc(sizeof (*cu) + sendsz + recvsz);
136 	if (cu == NULL) {
137 		(void) syslog(LOG_ERR, "clntudp_create: out of memory");
138 		rpc_createerr.cf_stat = RPC_SYSTEMERROR;
139 		rpc_createerr.cf_error.re_errno = errno;
140 		goto fooy;
141 	}
142 	cu->cu_outbuf = &cu->cu_inbuf[recvsz];
143 
144 	(void) gettimeofday(&now, (struct timezone *)0);
145 	if (raddr->sin_port == 0) {
146 		u_short port;
147 		if ((port =
148 		    pmap_getport(raddr, program, version, IPPROTO_UDP)) == 0) {
149 			goto fooy;
150 		}
151 		raddr->sin_port = htons(port);
152 	}
153 	cl->cl_ops = clntudp_ops();
154 	cl->cl_private = (caddr_t)cu;
155 	cu->cu_raddr = *raddr;
156 	cu->cu_rlen = sizeof (cu->cu_raddr);
157 	cu->cu_wait = wait;
158 	cu->cu_total.tv_sec = -1;
159 	cu->cu_total.tv_usec = -1;
160 	cu->cu_sendsz = sendsz;
161 	cu->cu_recvsz = recvsz;
162 	call_msg.rm_xid = getpid() ^ now.tv_sec ^ now.tv_usec;
163 	call_msg.rm_direction = CALL;
164 	call_msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
165 	call_msg.rm_call.cb_prog = program;
166 	call_msg.rm_call.cb_vers = version;
167 	xdrmem_create(&(cu->cu_outxdrs), cu->cu_outbuf,
168 	    sendsz, XDR_ENCODE);
169 	if (! xdr_callhdr(&(cu->cu_outxdrs), &call_msg)) {
170 		goto fooy;
171 	}
172 	cu->cu_xdrpos = XDR_GETPOS(&(cu->cu_outxdrs));
173 	if (*sockp < 0) {
174 		int dontblock = 1;
175 
176 		*sockp = _socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
177 		if (*sockp < 0) {
178 			rpc_createerr.cf_stat = RPC_SYSTEMERROR;
179 			rpc_createerr.cf_error.re_errno = errno;
180 			goto fooy;
181 		}
182 		/* attempt to bind to prov port */
183 		(void) bindresvport(*sockp, (struct sockaddr_in *)0);
184 		/* the sockets rpc controls are non-blocking */
185 		(void) ioctl(*sockp, FIONBIO, (char *) &dontblock);
186 		cu->cu_closeit = TRUE;
187 	} else {
188 		cu->cu_closeit = FALSE;
189 	}
190 	cu->cu_sock = *sockp;
191 	cl->cl_auth = authnone_create();
192 	return (cl);
193 fooy:
194 	if (cu)
195 		mem_free((caddr_t)cu, sizeof (*cu) + sendsz + recvsz);
196 	if (cl)
197 		mem_free((caddr_t)cl, sizeof (CLIENT));
198 	return ((CLIENT *)NULL);
199 }
200 
201 CLIENT *
202 clntudp_create(raddr, program, version, wait, sockp)
203 	struct sockaddr_in *raddr;
204 	rpcprog_t program;
205 	rpcvers_t version;
206 	struct timeval wait;
207 	register int *sockp;
208 {
209 
210 	return (clntudp_bufcreate(raddr, program, version, wait, sockp,
211 	    UDPMSGSIZE, UDPMSGSIZE));
212 }
213 
214 static enum clnt_stat
215 clntudp_call(cl, proc, xargs, argsp, xresults, resultsp, utimeout)
216 	register CLIENT	*cl;		/* client handle */
217 	rpcproc_t	proc;		/* procedure number */
218 	xdrproc_t	xargs;		/* xdr routine for args */
219 	caddr_t		argsp;		/* pointer to args */
220 	xdrproc_t	xresults;	/* xdr routine for results */
221 	caddr_t		resultsp;	/* pointer to results */
222 	struct timeval	utimeout;	/* seconds to wait before giving up */
223 {
224 	register struct cu_data *cu = (struct cu_data *)cl->cl_private;
225 	register XDR *xdrs;
226 	register int outlen;
227 	register int inlen;
228 	int fromlen;
229 	fd_set readfds;
230 	fd_set mask;
231 	struct sockaddr_in from;
232 	struct rpc_msg reply_msg;
233 	XDR reply_xdrs;
234 	struct timeval startime, curtime;
235 	int firsttimeout = 1;
236 	struct timeval time_waited;
237 	struct timeval retransmit_time;
238 	bool_t ok;
239 	int nrefreshes = 2;	/* number of times to refresh cred */
240 	struct timeval timeout;
241 
242 	if (cu->cu_total.tv_usec == -1) {
243 		timeout = utimeout;	/* use supplied timeout */
244 	} else {
245 		timeout = cu->cu_total; /* use default timeout */
246 	}
247 
248 	time_waited.tv_sec = 0;
249 	time_waited.tv_usec = 0;
250 	retransmit_time = cu->cu_wait;
251 
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_PUTINT32(xdrs, (int32_t *)&proc)) ||
261 	    (! AUTH_MARSHALL(cl->cl_auth, xdrs)) ||
262 	    (! (*xargs)(xdrs, argsp)))
263 		return (cu->cu_error.re_status = RPC_CANTENCODEARGS);
264 	outlen = (int)XDR_GETPOS(xdrs);
265 
266 send_again:
267 	if (_sendto(cu->cu_sock, cu->cu_outbuf, outlen, 0,
268 	    (struct sockaddr *)&(cu->cu_raddr), cu->cu_rlen)
269 	    != outlen) {
270 		cu->cu_error.re_errno = errno;
271 		return (cu->cu_error.re_status = RPC_CANTSEND);
272 	}
273 
274 	/*
275 	 * Hack to provide rpc-based message passing
276 	 */
277 	if (timeout.tv_sec == 0 && timeout.tv_usec == 0) {
278 		return (cu->cu_error.re_status = RPC_TIMEDOUT);
279 	}
280 	/*
281 	 * sub-optimal code appears here because we have
282 	 * some clock time to spare while the packets are in flight.
283 	 * (We assume that this is actually only executed once.)
284 	 */
285 	reply_msg.acpted_rply.ar_verf = _null_auth;
286 	reply_msg.acpted_rply.ar_results.where = resultsp;
287 	reply_msg.acpted_rply.ar_results.proc = xresults;
288 	FD_ZERO(&mask);
289 	FD_SET(cu->cu_sock, &mask);
290 	for (;;) {
291 		readfds = mask;
292 		switch (select(__rpc_dtbsize(), &readfds, NULL,
293 		    NULL, &(retransmit_time))) {
294 
295 		case 0:
296 			time_waited.tv_sec += retransmit_time.tv_sec;
297 			time_waited.tv_usec += retransmit_time.tv_usec;
298 			while (time_waited.tv_usec >= 1000000) {
299 				time_waited.tv_sec++;
300 				time_waited.tv_usec -= 1000000;
301 			}
302 
303 			/* update retransmit_time */
304 
305 			if (retransmit_time.tv_sec < RPC_MAX_BACKOFF) {
306 			retransmit_time.tv_usec += retransmit_time.tv_usec;
307 			retransmit_time.tv_sec += retransmit_time.tv_sec;
308 			while (retransmit_time.tv_usec >= 1000000) {
309 				retransmit_time.tv_sec++;
310 				retransmit_time.tv_usec -= 1000000;
311 				}
312 			}
313 
314 			if ((time_waited.tv_sec < timeout.tv_sec) ||
315 				((time_waited.tv_sec == timeout.tv_sec) &&
316 				(time_waited.tv_usec < timeout.tv_usec)))
317 				goto send_again;
318 			return (cu->cu_error.re_status = RPC_TIMEDOUT);
319 
320 		/*
321 		 * buggy in other cases because time_waited is not being
322 		 * updated.
323 		 */
324 		case -1:
325 			if (errno != EINTR) {
326 				cu->cu_error.re_errno = errno;
327 				return (cu->cu_error.re_status = RPC_CANTRECV);
328 			}
329 
330 			/* interrupted by another signal, update time_waited */
331 			if (firsttimeout) {
332 				/*
333 				 * Could have done gettimeofday before clnt_call
334 				 * but that means 1 more system call per each
335 				 * clnt_call, so do it after first time out
336 				 */
337 				if (gettimeofday(&startime,
338 					(struct timezone *) NULL) == -1) {
339 					errno = 0;
340 					continue;
341 				}
342 				firsttimeout = 0;
343 				errno = 0;
344 				continue;
345 			};
346 
347 			if (gettimeofday(&curtime,
348 				(struct timezone *) NULL) == -1) {
349 				errno = 0;
350 				continue;
351 			};
352 
353 			time_waited.tv_sec += curtime.tv_sec - startime.tv_sec;
354 			time_waited.tv_usec += curtime.tv_usec -
355 							startime.tv_usec;
356 			while (time_waited.tv_usec < 0) {
357 				time_waited.tv_sec--;
358 				time_waited.tv_usec += 1000000;
359 			};
360 			while (time_waited.tv_usec >= 1000000) {
361 				time_waited.tv_sec++;
362 				time_waited.tv_usec -= 1000000;
363 			}
364 			startime.tv_sec = curtime.tv_sec;
365 			startime.tv_usec = curtime.tv_usec;
366 			if ((time_waited.tv_sec > timeout.tv_sec) ||
367 				((time_waited.tv_sec == timeout.tv_sec) &&
368 				(time_waited.tv_usec > timeout.tv_usec))) {
369 				return (cu->cu_error.re_status = RPC_TIMEDOUT);
370 			}
371 			errno = 0; /* reset it */
372 			continue;
373 
374 		}
375 		do {
376 			fromlen = sizeof (struct sockaddr);
377 			inlen = _recvfrom(cu->cu_sock, cu->cu_inbuf,
378 				(int) cu->cu_recvsz, 0,
379 				(struct sockaddr *)&from, &fromlen);
380 		} while (inlen < 0 && errno == EINTR);
381 		if (inlen < 0) {
382 			if (errno == EWOULDBLOCK)
383 				continue;
384 			cu->cu_error.re_errno = errno;
385 			return (cu->cu_error.re_status = RPC_CANTRECV);
386 		}
387 		if (inlen < sizeof (uint32_t))
388 			continue;
389 		/* see if reply transaction id matches sent id */
390 		if (*((uint32_t *)(cu->cu_inbuf)) !=
391 				*((uint32_t *)(cu->cu_outbuf)))
392 			continue;
393 		/* we now assume we have the proper reply */
394 		break;
395 	}
396 
397 	/*
398 	 * now decode and validate the response
399 	 */
400 	xdrmem_create(&reply_xdrs, cu->cu_inbuf, (u_int)inlen, XDR_DECODE);
401 	ok = xdr_replymsg(&reply_xdrs, &reply_msg);
402 	/* XDR_DESTROY(&reply_xdrs);  save a few cycles on noop destroy */
403 	if (ok) {
404 		__seterr_reply(&reply_msg, &(cu->cu_error));
405 		if (cu->cu_error.re_status == RPC_SUCCESS) {
406 			if (! AUTH_VALIDATE(cl->cl_auth,
407 				&reply_msg.acpted_rply.ar_verf)) {
408 				cu->cu_error.re_status = RPC_AUTHERROR;
409 				cu->cu_error.re_why = AUTH_INVALIDRESP;
410 			}
411 			if (reply_msg.acpted_rply.ar_verf.oa_base != NULL) {
412 				xdrs->x_op = XDR_FREE;
413 				(void) xdr_opaque_auth(xdrs,
414 				    &(reply_msg.acpted_rply.ar_verf));
415 			}
416 		}  /* end successful completion */
417 		else {
418 			/* maybe our credentials need to be refreshed ... */
419 			if (nrefreshes > 0 &&
420 				AUTH_REFRESH(cl->cl_auth, &reply_msg)) {
421 				nrefreshes--;
422 				goto call_again;
423 			}
424 		}  /* end of unsuccessful completion */
425 	}  /* end of valid reply message */
426 	else {
427 		cu->cu_error.re_status = RPC_CANTDECODERES;
428 	}
429 	return (cu->cu_error.re_status);
430 }
431 
432 static void
433 clntudp_geterr(cl, errp)
434 	CLIENT *cl;
435 	struct rpc_err *errp;
436 {
437 	register struct cu_data *cu = (struct cu_data *)cl->cl_private;
438 
439 	*errp = cu->cu_error;
440 }
441 
442 
443 static bool_t
444 clntudp_freeres(cl, xdr_res, res_ptr)
445 	CLIENT *cl;
446 	xdrproc_t xdr_res;
447 	caddr_t res_ptr;
448 {
449 	register struct cu_data *cu = (struct cu_data *)cl->cl_private;
450 	register XDR *xdrs = &(cu->cu_outxdrs);
451 
452 	xdrs->x_op = XDR_FREE;
453 	return ((*xdr_res)(xdrs, res_ptr));
454 }
455 
456 static void
457 clntudp_abort()
458 	/* CLIENT *h; */
459 {
460 }
461 
462 static bool_t
463 clntudp_control(cl, request, info)
464 	CLIENT *cl;
465 	int request;
466 	char *info;
467 {
468 	register struct cu_data *cu = (struct cu_data *)cl->cl_private;
469 
470 	switch (request) {
471 	case CLSET_TIMEOUT:
472 		cu->cu_total = *(struct timeval *)info;
473 		break;
474 	case CLGET_TIMEOUT:
475 		*(struct timeval *)info = cu->cu_total;
476 		break;
477 	case CLSET_RETRY_TIMEOUT:
478 		cu->cu_wait = *(struct timeval *)info;
479 		break;
480 	case CLGET_RETRY_TIMEOUT:
481 		*(struct timeval *)info = cu->cu_wait;
482 		break;
483 	case CLGET_SERVER_ADDR:
484 		*(struct sockaddr_in *)info = cu->cu_raddr;
485 		break;
486 	case CLGET_FD:
487 		*(int *)info = cu->cu_sock;
488 		break;
489 	case CLSET_FD_CLOSE:
490 		cu->cu_closeit = TRUE;
491 		break;
492 	case CLSET_FD_NCLOSE:
493 		cu->cu_closeit = FALSE;
494 		break;
495 	default:
496 		return (FALSE);
497 	}
498 	return (TRUE);
499 }
500 
501 static void
502 clntudp_destroy(cl)
503 	CLIENT *cl;
504 {
505 	register struct cu_data *cu = (struct cu_data *)cl->cl_private;
506 
507 	if (cu->cu_closeit) {
508 		(void) close(cu->cu_sock);
509 	}
510 	XDR_DESTROY(&(cu->cu_outxdrs));
511 	mem_free((caddr_t)cu, (sizeof (*cu) + cu->cu_sendsz + cu->cu_recvsz));
512 	mem_free((caddr_t)cl, sizeof (CLIENT));
513 }
514 
515 static struct clnt_ops *
516 clntudp_ops()
517 {
518 	static struct clnt_ops ops;
519 
520 	if (ops.cl_call == NULL) {
521 		ops.cl_call = clntudp_call;
522 		ops.cl_abort = clntudp_abort;
523 		ops.cl_geterr = clntudp_geterr;
524 		ops.cl_freeres = clntudp_freeres;
525 		ops.cl_destroy = clntudp_destroy;
526 		ops.cl_control = clntudp_control;
527 	}
528 	return (&ops);
529 }
530