xref: /freebsd/lib/libc/xdr/xdr.c (revision 417ed37975261df51f61d13e179ad04d8f4839c7)
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 *sccsid = "from: @(#)xdr.c 1.35 87/08/12";*/
32 /*static char *sccsid = "from: @(#)xdr.c	2.1 88/07/29 4.0 RPCSRC";*/
33 static char *rcsid = "$Id: xdr.c,v 1.1 1993/10/27 05:41:06 paul Exp $";
34 #endif
35 
36 /*
37  * xdr.c, Generic XDR routines implementation.
38  *
39  * Copyright (C) 1986, Sun Microsystems, Inc.
40  *
41  * These are the "generic" xdr routines used to serialize and de-serialize
42  * most common data items.  See xdr.h for more info on the interface to
43  * xdr.
44  */
45 
46 #include <stdio.h>
47 
48 #include <rpc/types.h>
49 #include <rpc/xdr.h>
50 
51 /*
52  * constants specific to the xdr "protocol"
53  */
54 #define XDR_FALSE	((long) 0)
55 #define XDR_TRUE	((long) 1)
56 #define LASTUNSIGNED	((u_int) 0-1)
57 
58 /*
59  * for unit alignment
60  */
61 static char xdr_zero[BYTES_PER_XDR_UNIT] = { 0, 0, 0, 0 };
62 
63 /*
64  * Free a data structure using XDR
65  * Not a filter, but a convenient utility nonetheless
66  */
67 void
68 xdr_free(proc, objp)
69 	xdrproc_t proc;
70 	char *objp;
71 {
72 	XDR x;
73 
74 	x.x_op = XDR_FREE;
75 	(*proc)(&x, objp);
76 }
77 
78 /*
79  * XDR nothing
80  */
81 bool_t
82 xdr_void(/* xdrs, addr */)
83 	/* XDR *xdrs; */
84 	/* caddr_t addr; */
85 {
86 
87 	return (TRUE);
88 }
89 
90 /*
91  * XDR integers
92  */
93 bool_t
94 xdr_int(xdrs, ip)
95 	XDR *xdrs;
96 	int *ip;
97 {
98 
99 #ifdef lint
100 	(void) (xdr_short(xdrs, (short *)ip));
101 	return (xdr_long(xdrs, (long *)ip));
102 #else
103 	if (sizeof (int) == sizeof (long)) {
104 		return (xdr_long(xdrs, (long *)ip));
105 	} else {
106 		return (xdr_short(xdrs, (short *)ip));
107 	}
108 #endif
109 }
110 
111 /*
112  * XDR unsigned integers
113  */
114 bool_t
115 xdr_u_int(xdrs, up)
116 	XDR *xdrs;
117 	u_int *up;
118 {
119 
120 #ifdef lint
121 	(void) (xdr_short(xdrs, (short *)up));
122 	return (xdr_u_long(xdrs, (u_long *)up));
123 #else
124 	if (sizeof (u_int) == sizeof (u_long)) {
125 		return (xdr_u_long(xdrs, (u_long *)up));
126 	} else {
127 		return (xdr_short(xdrs, (short *)up));
128 	}
129 #endif
130 }
131 
132 /*
133  * XDR long integers
134  * same as xdr_u_long - open coded to save a proc call!
135  */
136 bool_t
137 xdr_long(xdrs, lp)
138 	register XDR *xdrs;
139 	long *lp;
140 {
141 
142 	if (xdrs->x_op == XDR_ENCODE)
143 		return (XDR_PUTLONG(xdrs, lp));
144 
145 	if (xdrs->x_op == XDR_DECODE)
146 		return (XDR_GETLONG(xdrs, lp));
147 
148 	if (xdrs->x_op == XDR_FREE)
149 		return (TRUE);
150 
151 	return (FALSE);
152 }
153 
154 /*
155  * XDR unsigned long integers
156  * same as xdr_long - open coded to save a proc call!
157  */
158 bool_t
159 xdr_u_long(xdrs, ulp)
160 	register XDR *xdrs;
161 	u_long *ulp;
162 {
163 
164 	if (xdrs->x_op == XDR_DECODE)
165 		return (XDR_GETLONG(xdrs, (long *)ulp));
166 	if (xdrs->x_op == XDR_ENCODE)
167 		return (XDR_PUTLONG(xdrs, (long *)ulp));
168 	if (xdrs->x_op == XDR_FREE)
169 		return (TRUE);
170 	return (FALSE);
171 }
172 
173 /*
174  * XDR short integers
175  */
176 bool_t
177 xdr_short(xdrs, sp)
178 	register XDR *xdrs;
179 	short *sp;
180 {
181 	long l;
182 
183 	switch (xdrs->x_op) {
184 
185 	case XDR_ENCODE:
186 		l = (long) *sp;
187 		return (XDR_PUTLONG(xdrs, &l));
188 
189 	case XDR_DECODE:
190 		if (!XDR_GETLONG(xdrs, &l)) {
191 			return (FALSE);
192 		}
193 		*sp = (short) l;
194 		return (TRUE);
195 
196 	case XDR_FREE:
197 		return (TRUE);
198 	}
199 	return (FALSE);
200 }
201 
202 /*
203  * XDR unsigned short integers
204  */
205 bool_t
206 xdr_u_short(xdrs, usp)
207 	register XDR *xdrs;
208 	u_short *usp;
209 {
210 	u_long l;
211 
212 	switch (xdrs->x_op) {
213 
214 	case XDR_ENCODE:
215 		l = (u_long) *usp;
216 		return (XDR_PUTLONG(xdrs, &l));
217 
218 	case XDR_DECODE:
219 		if (!XDR_GETLONG(xdrs, &l)) {
220 			return (FALSE);
221 		}
222 		*usp = (u_short) l;
223 		return (TRUE);
224 
225 	case XDR_FREE:
226 		return (TRUE);
227 	}
228 	return (FALSE);
229 }
230 
231 
232 /*
233  * XDR a char
234  */
235 bool_t
236 xdr_char(xdrs, cp)
237 	XDR *xdrs;
238 	char *cp;
239 {
240 	int i;
241 
242 	i = (*cp);
243 	if (!xdr_int(xdrs, &i)) {
244 		return (FALSE);
245 	}
246 	*cp = i;
247 	return (TRUE);
248 }
249 
250 /*
251  * XDR an unsigned char
252  */
253 bool_t
254 xdr_u_char(xdrs, cp)
255 	XDR *xdrs;
256 	char *cp;
257 {
258 	u_int u;
259 
260 	u = (*cp);
261 	if (!xdr_u_int(xdrs, &u)) {
262 		return (FALSE);
263 	}
264 	*cp = u;
265 	return (TRUE);
266 }
267 
268 /*
269  * XDR booleans
270  */
271 bool_t
272 xdr_bool(xdrs, bp)
273 	register XDR *xdrs;
274 	bool_t *bp;
275 {
276 	long lb;
277 
278 	switch (xdrs->x_op) {
279 
280 	case XDR_ENCODE:
281 		lb = *bp ? XDR_TRUE : XDR_FALSE;
282 		return (XDR_PUTLONG(xdrs, &lb));
283 
284 	case XDR_DECODE:
285 		if (!XDR_GETLONG(xdrs, &lb)) {
286 			return (FALSE);
287 		}
288 		*bp = (lb == XDR_FALSE) ? FALSE : TRUE;
289 		return (TRUE);
290 
291 	case XDR_FREE:
292 		return (TRUE);
293 	}
294 	return (FALSE);
295 }
296 
297 /*
298  * XDR enumerations
299  */
300 bool_t
301 xdr_enum(xdrs, ep)
302 	XDR *xdrs;
303 	enum_t *ep;
304 {
305 #ifndef lint
306 	enum sizecheck { SIZEVAL };	/* used to find the size of an enum */
307 
308 	/*
309 	 * enums are treated as ints
310 	 */
311 	if (sizeof (enum sizecheck) == sizeof (long)) {
312 		return (xdr_long(xdrs, (long *)ep));
313 	} else if (sizeof (enum sizecheck) == sizeof (short)) {
314 		return (xdr_short(xdrs, (short *)ep));
315 	} else {
316 		return (FALSE);
317 	}
318 #else
319 	(void) (xdr_short(xdrs, (short *)ep));
320 	return (xdr_long(xdrs, (long *)ep));
321 #endif
322 }
323 
324 /*
325  * XDR opaque data
326  * Allows the specification of a fixed size sequence of opaque bytes.
327  * cp points to the opaque object and cnt gives the byte length.
328  */
329 bool_t
330 xdr_opaque(xdrs, cp, cnt)
331 	register XDR *xdrs;
332 	caddr_t cp;
333 	register u_int cnt;
334 {
335 	register u_int rndup;
336 	static crud[BYTES_PER_XDR_UNIT];
337 
338 	/*
339 	 * if no data we are done
340 	 */
341 	if (cnt == 0)
342 		return (TRUE);
343 
344 	/*
345 	 * round byte count to full xdr units
346 	 */
347 	rndup = cnt % BYTES_PER_XDR_UNIT;
348 	if (rndup > 0)
349 		rndup = BYTES_PER_XDR_UNIT - rndup;
350 
351 	if (xdrs->x_op == XDR_DECODE) {
352 		if (!XDR_GETBYTES(xdrs, cp, cnt)) {
353 			return (FALSE);
354 		}
355 		if (rndup == 0)
356 			return (TRUE);
357 		return (XDR_GETBYTES(xdrs, crud, rndup));
358 	}
359 
360 	if (xdrs->x_op == XDR_ENCODE) {
361 		if (!XDR_PUTBYTES(xdrs, cp, cnt)) {
362 			return (FALSE);
363 		}
364 		if (rndup == 0)
365 			return (TRUE);
366 		return (XDR_PUTBYTES(xdrs, xdr_zero, rndup));
367 	}
368 
369 	if (xdrs->x_op == XDR_FREE) {
370 		return (TRUE);
371 	}
372 
373 	return (FALSE);
374 }
375 
376 /*
377  * XDR counted bytes
378  * *cpp is a pointer to the bytes, *sizep is the count.
379  * If *cpp is NULL maxsize bytes are allocated
380  */
381 bool_t
382 xdr_bytes(xdrs, cpp, sizep, maxsize)
383 	register XDR *xdrs;
384 	char **cpp;
385 	register u_int *sizep;
386 	u_int maxsize;
387 {
388 	register char *sp = *cpp;  /* sp is the actual string pointer */
389 	register u_int nodesize;
390 
391 	/*
392 	 * first deal with the length since xdr bytes are counted
393 	 */
394 	if (! xdr_u_int(xdrs, sizep)) {
395 		return (FALSE);
396 	}
397 	nodesize = *sizep;
398 	if ((nodesize > maxsize) && (xdrs->x_op != XDR_FREE)) {
399 		return (FALSE);
400 	}
401 
402 	/*
403 	 * now deal with the actual bytes
404 	 */
405 	switch (xdrs->x_op) {
406 
407 	case XDR_DECODE:
408 		if (nodesize == 0) {
409 			return (TRUE);
410 		}
411 		if (sp == NULL) {
412 			*cpp = sp = (char *)mem_alloc(nodesize);
413 		}
414 		if (sp == NULL) {
415 			(void) fprintf(stderr, "xdr_bytes: out of memory\n");
416 			return (FALSE);
417 		}
418 		/* fall into ... */
419 
420 	case XDR_ENCODE:
421 		return (xdr_opaque(xdrs, sp, nodesize));
422 
423 	case XDR_FREE:
424 		if (sp != NULL) {
425 			mem_free(sp, nodesize);
426 			*cpp = NULL;
427 		}
428 		return (TRUE);
429 	}
430 	return (FALSE);
431 }
432 
433 /*
434  * Implemented here due to commonality of the object.
435  */
436 bool_t
437 xdr_netobj(xdrs, np)
438 	XDR *xdrs;
439 	struct netobj *np;
440 {
441 
442 	return (xdr_bytes(xdrs, &np->n_bytes, &np->n_len, MAX_NETOBJ_SZ));
443 }
444 
445 /*
446  * XDR a descriminated union
447  * Support routine for discriminated unions.
448  * You create an array of xdrdiscrim structures, terminated with
449  * an entry with a null procedure pointer.  The routine gets
450  * the discriminant value and then searches the array of xdrdiscrims
451  * looking for that value.  It calls the procedure given in the xdrdiscrim
452  * to handle the discriminant.  If there is no specific routine a default
453  * routine may be called.
454  * If there is no specific or default routine an error is returned.
455  */
456 bool_t
457 xdr_union(xdrs, dscmp, unp, choices, dfault)
458 	register XDR *xdrs;
459 	enum_t *dscmp;		/* enum to decide which arm to work on */
460 	char *unp;		/* the union itself */
461 	struct xdr_discrim *choices;	/* [value, xdr proc] for each arm */
462 	xdrproc_t dfault;	/* default xdr routine */
463 {
464 	register enum_t dscm;
465 
466 	/*
467 	 * we deal with the discriminator;  it's an enum
468 	 */
469 	if (! xdr_enum(xdrs, dscmp)) {
470 		return (FALSE);
471 	}
472 	dscm = *dscmp;
473 
474 	/*
475 	 * search choices for a value that matches the discriminator.
476 	 * if we find one, execute the xdr routine for that value.
477 	 */
478 	for (; choices->proc != NULL_xdrproc_t; choices++) {
479 		if (choices->value == dscm)
480 			return ((*(choices->proc))(xdrs, unp, LASTUNSIGNED));
481 	}
482 
483 	/*
484 	 * no match - execute the default xdr routine if there is one
485 	 */
486 	return ((dfault == NULL_xdrproc_t) ? FALSE :
487 	    (*dfault)(xdrs, unp, LASTUNSIGNED));
488 }
489 
490 
491 /*
492  * Non-portable xdr primitives.
493  * Care should be taken when moving these routines to new architectures.
494  */
495 
496 
497 /*
498  * XDR null terminated ASCII strings
499  * xdr_string deals with "C strings" - arrays of bytes that are
500  * terminated by a NULL character.  The parameter cpp references a
501  * pointer to storage; If the pointer is null, then the necessary
502  * storage is allocated.  The last parameter is the max allowed length
503  * of the string as specified by a protocol.
504  */
505 bool_t
506 xdr_string(xdrs, cpp, maxsize)
507 	register XDR *xdrs;
508 	char **cpp;
509 	u_int maxsize;
510 {
511 	register char *sp = *cpp;  /* sp is the actual string pointer */
512 	u_int size;
513 	u_int nodesize;
514 
515 	/*
516 	 * first deal with the length since xdr strings are counted-strings
517 	 */
518 	switch (xdrs->x_op) {
519 	case XDR_FREE:
520 		if (sp == NULL) {
521 			return(TRUE);	/* already free */
522 		}
523 		/* fall through... */
524 	case XDR_ENCODE:
525 		size = strlen(sp);
526 		break;
527 	}
528 	if (! xdr_u_int(xdrs, &size)) {
529 		return (FALSE);
530 	}
531 	if (size > maxsize) {
532 		return (FALSE);
533 	}
534 	nodesize = size + 1;
535 
536 	/*
537 	 * now deal with the actual bytes
538 	 */
539 	switch (xdrs->x_op) {
540 
541 	case XDR_DECODE:
542 		if (nodesize == 0) {
543 			return (TRUE);
544 		}
545 		if (sp == NULL)
546 			*cpp = sp = (char *)mem_alloc(nodesize);
547 		if (sp == NULL) {
548 			(void) fprintf(stderr, "xdr_string: out of memory\n");
549 			return (FALSE);
550 		}
551 		sp[size] = 0;
552 		/* fall into ... */
553 
554 	case XDR_ENCODE:
555 		return (xdr_opaque(xdrs, sp, size));
556 
557 	case XDR_FREE:
558 		mem_free(sp, nodesize);
559 		*cpp = NULL;
560 		return (TRUE);
561 	}
562 	return (FALSE);
563 }
564 
565 /*
566  * Wrapper for xdr_string that can be called directly from
567  * routines like clnt_call
568  */
569 bool_t
570 xdr_wrapstring(xdrs, cpp)
571 	XDR *xdrs;
572 	char **cpp;
573 {
574 	if (xdr_string(xdrs, cpp, LASTUNSIGNED)) {
575 		return (TRUE);
576 	}
577 	return (FALSE);
578 }
579