xref: /illumos-gate/usr/src/uts/common/rpc/xdr.c (revision 8b80e8cb6855118d46f605e91b5ed4ce83417395)
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 (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /*	Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T	*/
27 /*	  All Rights Reserved  	*/
28 
29 /*
30  * Portions of this source code were derived from Berkeley 4.3 BSD
31  * under license from the Regents of the University of California.
32  */
33 
34 /*
35  * xdr.c, generic XDR routines implementation.
36  * These are the "generic" xdr routines used to serialize and de-serialize
37  * most common data items.  See xdr.h for more info on the interface to
38  * xdr.
39  */
40 
41 #include <sys/param.h>
42 #include <sys/cmn_err.h>
43 #include <sys/types.h>
44 #include <sys/systm.h>
45 
46 #include <rpc/types.h>
47 #include <rpc/xdr.h>
48 #include <sys/isa_defs.h>
49 
50 #pragma weak xdr_int32_t = xdr_int
51 #pragma weak xdr_uint32_t = xdr_u_int
52 #pragma weak xdr_int64_t = xdr_longlong_t
53 #pragma weak xdr_uint64_t = xdr_u_longlong_t
54 
55 #if !defined(_BIG_ENDIAN) && !defined(_LITTLE_ENDIAN)
56 #error "Exactly one of _BIG_ENDIAN or _LITTLE_ENDIAN must be defined"
57 #elif defined(_BIG_ENDIAN) && defined(_LITTLE_ENDIAN)
58 #error "Only one of _BIG_ENDIAN or _LITTLE_ENDIAN may be defined"
59 #endif
60 
61 /*
62  * constants specific to the xdr "protocol"
63  */
64 #define	XDR_FALSE	((int32_t)0)
65 #define	XDR_TRUE	((int32_t)1)
66 #define	LASTUNSIGNED	((uint_t)0-1)
67 
68 /*
69  * for unit alignment
70  */
71 static char xdr_zero[BYTES_PER_XDR_UNIT] = { 0, 0, 0, 0 };
72 
73 /*
74  * Free a data structure using XDR
75  * Not a filter, but a convenient utility nonetheless
76  */
77 void
78 xdr_free(xdrproc_t proc, char *objp)
79 {
80 	XDR x;
81 
82 	x.x_op = XDR_FREE;
83 	(*proc)(&x, objp);
84 }
85 
86 /*
87  * XDR nothing
88  */
89 bool_t
90 xdr_void(void)
91 {
92 	return (TRUE);
93 }
94 
95 /*
96  * XDR integers
97  *
98  * PSARC 2003/523 Contract Private Interface
99  * xdr_int
100  * Changes must be reviewed by Solaris File Sharing
101  * Changes must be communicated to contract-2003-523@sun.com
102  */
103 bool_t
104 xdr_int(XDR *xdrs, int *ip)
105 {
106 	if (xdrs->x_op == XDR_ENCODE)
107 		return (XDR_PUTINT32(xdrs, ip));
108 
109 	if (xdrs->x_op == XDR_DECODE)
110 		return (XDR_GETINT32(xdrs, ip));
111 
112 	if (xdrs->x_op == XDR_FREE)
113 		return (TRUE);
114 
115 	return (FALSE);
116 }
117 
118 /*
119  * XDR unsigned integers
120  *
121  * PSARC 2003/523 Contract Private Interface
122  * xdr_u_int
123  * Changes must be reviewed by Solaris File Sharing
124  * Changes must be communicated to contract-2003-523@sun.com
125  */
126 bool_t
127 xdr_u_int(XDR *xdrs, uint_t *up)
128 {
129 	if (xdrs->x_op == XDR_ENCODE)
130 		return (XDR_PUTINT32(xdrs, (int32_t *)up));
131 
132 	if (xdrs->x_op == XDR_DECODE)
133 		return (XDR_GETINT32(xdrs, (int32_t *)up));
134 
135 	if (xdrs->x_op == XDR_FREE)
136 		return (TRUE);
137 
138 	return (FALSE);
139 }
140 
141 
142 #if defined(_ILP32)
143 /*
144  * xdr_long and xdr_u_long for binary compatability on ILP32 kernels.
145  *
146  * No prototypes since new code should not be using these interfaces.
147  */
148 bool_t
149 xdr_long(XDR *xdrs, long *ip)
150 {
151 	return (xdr_int(xdrs, (int *)ip));
152 }
153 
154 bool_t
155 xdr_u_long(XDR *xdrs, unsigned long *up)
156 {
157 	return (xdr_u_int(xdrs, (uint_t *)up));
158 }
159 #endif /* _ILP32 */
160 
161 
162 /*
163  * XDR long long integers
164  */
165 bool_t
166 xdr_longlong_t(XDR *xdrs, longlong_t *hp)
167 {
168 	if (xdrs->x_op == XDR_ENCODE) {
169 #if defined(_LITTLE_ENDIAN)
170 		if (XDR_PUTINT32(xdrs, (int32_t *)((char *)hp +
171 		    BYTES_PER_XDR_UNIT)) == TRUE) {
172 			return (XDR_PUTINT32(xdrs, (int32_t *)hp));
173 		}
174 #elif defined(_BIG_ENDIAN)
175 		if (XDR_PUTINT32(xdrs, (int32_t *)hp) == TRUE) {
176 			return (XDR_PUTINT32(xdrs, (int32_t *)((char *)hp +
177 			    BYTES_PER_XDR_UNIT)));
178 		}
179 #endif
180 		return (FALSE);
181 
182 	}
183 	if (xdrs->x_op == XDR_DECODE) {
184 #if defined(_LITTLE_ENDIAN)
185 		if (XDR_GETINT32(xdrs, (int32_t *)((char *)hp +
186 		    BYTES_PER_XDR_UNIT)) == TRUE) {
187 			return (XDR_GETINT32(xdrs, (int32_t *)hp));
188 		}
189 #elif defined(_BIG_ENDIAN)
190 		if (XDR_GETINT32(xdrs, (int32_t *)hp) == TRUE) {
191 			return (XDR_GETINT32(xdrs, (int32_t *)((char *)hp +
192 			    BYTES_PER_XDR_UNIT)));
193 		}
194 #endif
195 		return (FALSE);
196 	}
197 	return (TRUE);
198 }
199 
200 /*
201  * XDR unsigned long long integers
202  */
203 bool_t
204 xdr_u_longlong_t(XDR *xdrs, u_longlong_t *hp)
205 {
206 
207 	if (xdrs->x_op == XDR_ENCODE) {
208 #if defined(_LITTLE_ENDIAN)
209 		if (XDR_PUTINT32(xdrs, (int32_t *)((char *)hp +
210 		    BYTES_PER_XDR_UNIT)) == TRUE) {
211 			return (XDR_PUTINT32(xdrs, (int32_t *)hp));
212 		}
213 #elif defined(_BIG_ENDIAN)
214 		if (XDR_PUTINT32(xdrs, (int32_t *)hp) == TRUE) {
215 			return (XDR_PUTINT32(xdrs, (int32_t *)((char *)hp +
216 			    BYTES_PER_XDR_UNIT)));
217 		}
218 #endif
219 		return (FALSE);
220 
221 	}
222 	if (xdrs->x_op == XDR_DECODE) {
223 #if defined(_LITTLE_ENDIAN)
224 		if (XDR_GETINT32(xdrs, (int32_t *)((char *)hp +
225 		    BYTES_PER_XDR_UNIT)) == TRUE) {
226 			return (XDR_GETINT32(xdrs, (int32_t *)hp));
227 		}
228 #elif defined(_BIG_ENDIAN)
229 		if (XDR_GETINT32(xdrs, (int32_t *)hp) == TRUE) {
230 			return (XDR_GETINT32(xdrs, (int32_t *)((char *)hp +
231 			    BYTES_PER_XDR_UNIT)));
232 		}
233 #endif
234 		return (FALSE);
235 	}
236 	return (TRUE);
237 }
238 
239 /*
240  * XDR short integers
241  */
242 bool_t
243 xdr_short(XDR *xdrs, short *sp)
244 {
245 	int32_t l;
246 
247 	switch (xdrs->x_op) {
248 
249 	case XDR_ENCODE:
250 		l = (int32_t)*sp;
251 		return (XDR_PUTINT32(xdrs, &l));
252 
253 	case XDR_DECODE:
254 		if (!XDR_GETINT32(xdrs, &l))
255 			return (FALSE);
256 		*sp = (short)l;
257 		return (TRUE);
258 
259 	case XDR_FREE:
260 		return (TRUE);
261 	}
262 	return (FALSE);
263 }
264 
265 /*
266  * XDR unsigned short integers
267  */
268 bool_t
269 xdr_u_short(XDR *xdrs, ushort_t *usp)
270 {
271 	uint32_t l;
272 
273 	switch (xdrs->x_op) {
274 
275 	case XDR_ENCODE:
276 		l = (uint32_t)*usp;
277 		return (XDR_PUTINT32(xdrs, (int32_t *)&l));
278 
279 	case XDR_DECODE:
280 		if (!XDR_GETINT32(xdrs, (int32_t *)&l)) {
281 			return (FALSE);
282 		}
283 		*usp = (ushort_t)l;
284 		return (TRUE);
285 
286 	case XDR_FREE:
287 		return (TRUE);
288 	}
289 	return (FALSE);
290 }
291 
292 
293 /*
294  * XDR a char
295  */
296 bool_t
297 xdr_char(XDR *xdrs, char *cp)
298 {
299 	int i;
300 
301 	i = (*cp);
302 	if (!xdr_int(xdrs, &i)) {
303 		return (FALSE);
304 	}
305 	*cp = (char)i;
306 	return (TRUE);
307 }
308 
309 /*
310  * XDR booleans
311  *
312  * PSARC 2003/523 Contract Private Interface
313  * xdr_bool
314  * Changes must be reviewed by Solaris File Sharing
315  * Changes must be communicated to contract-2003-523@sun.com
316  */
317 bool_t
318 xdr_bool(XDR *xdrs, bool_t *bp)
319 {
320 	int32_t i32b;
321 
322 	switch (xdrs->x_op) {
323 
324 	case XDR_ENCODE:
325 		i32b = *bp ? XDR_TRUE : XDR_FALSE;
326 		return (XDR_PUTINT32(xdrs, &i32b));
327 
328 	case XDR_DECODE:
329 		if (!XDR_GETINT32(xdrs, &i32b)) {
330 			return (FALSE);
331 		}
332 		*bp = (i32b == XDR_FALSE) ? FALSE : TRUE;
333 		return (TRUE);
334 
335 	case XDR_FREE:
336 		return (TRUE);
337 	}
338 	return (FALSE);
339 }
340 
341 /*
342  * XDR enumerations
343  *
344  * PSARC 2003/523 Contract Private Interface
345  * xdr_enum
346  * Changes must be reviewed by Solaris File Sharing
347  * Changes must be communicated to contract-2003-523@sun.com
348  */
349 #ifndef lint
350 enum sizecheck { SIZEVAL } sizecheckvar;	/* used to find the size of */
351 						/* an enum */
352 #endif
353 bool_t
354 xdr_enum(XDR *xdrs, enum_t *ep)
355 {
356 #ifndef lint
357 	/*
358 	 * enums are treated as ints
359 	 */
360 	if (sizeof (sizecheckvar) == sizeof (int32_t)) {
361 		return (xdr_int(xdrs, (int32_t *)ep));
362 	} else if (sizeof (sizecheckvar) == sizeof (short)) {
363 		return (xdr_short(xdrs, (short *)ep));
364 	} else {
365 		return (FALSE);
366 	}
367 #else
368 	(void) (xdr_short(xdrs, (short *)ep));
369 	return (xdr_int(xdrs, (int32_t *)ep));
370 #endif
371 }
372 
373 /*
374  * XDR opaque data
375  * Allows the specification of a fixed size sequence of opaque bytes.
376  * cp points to the opaque object and cnt gives the byte length.
377  *
378  * PSARC 2003/523 Contract Private Interface
379  * xdr_opaque
380  * Changes must be reviewed by Solaris File Sharing
381  * Changes must be communicated to contract-2003-523@sun.com
382  */
383 bool_t
384 xdr_opaque(XDR *xdrs, caddr_t cp, const uint_t cnt)
385 {
386 	uint_t rndup;
387 	static char crud[BYTES_PER_XDR_UNIT];
388 
389 	/*
390 	 * if no data we are done
391 	 */
392 	if (cnt == 0)
393 		return (TRUE);
394 
395 	/*
396 	 * round byte count to full xdr units
397 	 */
398 	rndup = cnt % BYTES_PER_XDR_UNIT;
399 	if (rndup != 0)
400 		rndup = BYTES_PER_XDR_UNIT - rndup;
401 
402 	if (xdrs->x_op == XDR_DECODE) {
403 		if (!XDR_GETBYTES(xdrs, cp, cnt)) {
404 			return (FALSE);
405 		}
406 		if (rndup == 0)
407 			return (TRUE);
408 		return (XDR_GETBYTES(xdrs, (caddr_t)crud, rndup));
409 	}
410 
411 	if (xdrs->x_op == XDR_ENCODE) {
412 		if (!XDR_PUTBYTES(xdrs, cp, cnt)) {
413 			return (FALSE);
414 		}
415 		if (rndup == 0)
416 			return (TRUE);
417 		return (XDR_PUTBYTES(xdrs, xdr_zero, rndup));
418 	}
419 
420 	if (xdrs->x_op == XDR_FREE)
421 		return (TRUE);
422 
423 	return (FALSE);
424 }
425 
426 /*
427  * XDR counted bytes
428  * *cpp is a pointer to the bytes, *sizep is the count.
429  * If *cpp is NULL maxsize bytes are allocated
430  *
431  * PSARC 2003/523 Contract Private Interface
432  * xdr_bytes
433  * Changes must be reviewed by Solaris File Sharing
434  * Changes must be communicated to contract-2003-523@sun.com
435  */
436 bool_t
437 xdr_bytes(XDR *xdrs, char **cpp, uint_t *sizep, const uint_t maxsize)
438 {
439 	char *sp = *cpp;  /* sp is the actual string pointer */
440 	uint_t nodesize;
441 
442 	/*
443 	 * first deal with the length since xdr bytes are counted
444 	 */
445 	if (!xdr_u_int(xdrs, sizep)) {
446 		return (FALSE);
447 	}
448 	nodesize = *sizep;
449 	if ((nodesize > maxsize) && (xdrs->x_op != XDR_FREE)) {
450 		return (FALSE);
451 	}
452 
453 	/*
454 	 * now deal with the actual bytes
455 	 */
456 	switch (xdrs->x_op) {
457 	case XDR_DECODE:
458 		if (nodesize == 0)
459 			return (TRUE);
460 		if (sp == NULL)
461 			*cpp = sp = (char *)mem_alloc(nodesize);
462 		/* FALLTHROUGH */
463 
464 	case XDR_ENCODE:
465 		return (xdr_opaque(xdrs, sp, nodesize));
466 
467 	case XDR_FREE:
468 		if (sp != NULL) {
469 			mem_free(sp, nodesize);
470 			*cpp = NULL;
471 		}
472 		return (TRUE);
473 	}
474 	return (FALSE);
475 }
476 
477 /*
478  * Implemented here due to commonality of the object.
479  */
480 bool_t
481 xdr_netobj(XDR *xdrs, struct netobj *np)
482 {
483 	return (xdr_bytes(xdrs, &np->n_bytes, &np->n_len, MAX_NETOBJ_SZ));
484 }
485 
486 /*
487  * XDR a descriminated union
488  * Support routine for discriminated unions.
489  * You create an array of xdrdiscrim structures, terminated with
490  * an entry with a null procedure pointer.  The routine gets
491  * the discriminant value and then searches the array of xdrdiscrims
492  * looking for that value.  It calls the procedure given in the xdrdiscrim
493  * to handle the discriminant.  If there is no specific routine a default
494  * routine may be called.
495  * If there is no specific or default routine an error is returned.
496  */
497 bool_t
498 xdr_union(XDR *xdrs, enum_t *dscmp, char *unp,
499 	const struct xdr_discrim *choices, const xdrproc_t dfault)
500 {
501 	enum_t dscm;
502 
503 	/*
504 	 * we deal with the discriminator;  it's an enum
505 	 */
506 	if (!xdr_enum(xdrs, dscmp)) {
507 		return (FALSE);
508 	}
509 	dscm = *dscmp;
510 
511 	/*
512 	 * search choices for a value that matches the discriminator.
513 	 * if we find one, execute the xdr routine for that value.
514 	 */
515 	for (; choices->proc != NULL_xdrproc_t; choices++) {
516 		if (choices->value == dscm)
517 			return ((*(choices->proc))(xdrs, unp, LASTUNSIGNED));
518 	}
519 
520 	/*
521 	 * no match - execute the default xdr routine if there is one
522 	 */
523 	return ((dfault == NULL_xdrproc_t) ? FALSE :
524 	    (*dfault)(xdrs, unp, LASTUNSIGNED));
525 }
526 
527 
528 /*
529  * Non-portable xdr primitives.
530  * Care should be taken when moving these routines to new architectures.
531  */
532 
533 
534 /*
535  * XDR null terminated ASCII strings
536  * xdr_string deals with "C strings" - arrays of bytes that are
537  * terminated by a NULL character.  The parameter cpp references a
538  * pointer to storage; If the pointer is null, then the necessary
539  * storage is allocated.  The last parameter is the max allowed length
540  * of the string as specified by a protocol.
541  */
542 bool_t
543 xdr_string(XDR *xdrs, char **cpp, const uint_t maxsize)
544 {
545 	char *sp = *cpp;  /* sp is the actual string pointer */
546 	uint_t size;
547 	uint_t nodesize;
548 
549 	/*
550 	 * first deal with the length since xdr strings are counted-strings
551 	 */
552 	switch (xdrs->x_op) {
553 	case XDR_FREE:
554 		if (sp == NULL)
555 			return (TRUE);	/* already free */
556 		/* FALLTHROUGH */
557 	case XDR_ENCODE:
558 		size = (sp != NULL) ? (uint_t)strlen(sp) : 0;
559 		break;
560 	case XDR_DECODE:
561 		break;
562 	}
563 	if (!xdr_u_int(xdrs, &size)) {
564 		return (FALSE);
565 	}
566 	if (size > maxsize) {
567 		return (FALSE);
568 	}
569 	nodesize = size + 1;
570 
571 	/*
572 	 * now deal with the actual bytes
573 	 */
574 	switch (xdrs->x_op) {
575 	case XDR_DECODE:
576 		if (nodesize == 0)
577 			return (TRUE);
578 		if (sp == NULL)
579 			sp = (char *)mem_alloc(nodesize);
580 		sp[size] = 0;
581 		if (!xdr_opaque(xdrs, sp, size)) {
582 			/*
583 			 * free up memory if allocated here
584 			 */
585 			if (*cpp == NULL) {
586 				mem_free(sp, nodesize);
587 			}
588 			return (FALSE);
589 		}
590 		if (strlen(sp) != size) {
591 			if (*cpp == NULL) {
592 				mem_free(sp, nodesize);
593 			}
594 			return (FALSE);
595 		}
596 		*cpp = sp;
597 		return (TRUE);
598 
599 	case XDR_ENCODE:
600 		return (xdr_opaque(xdrs, sp, size));
601 
602 	case XDR_FREE:
603 		mem_free(sp, nodesize);
604 		*cpp = NULL;
605 		return (TRUE);
606 	}
607 	return (FALSE);
608 }
609 
610 /*
611  * Wrapper for xdr_string that can be called directly from
612  * routines like clnt_call
613  */
614 bool_t
615 xdr_wrapstring(XDR *xdrs, char **cpp)
616 {
617 	if (xdr_string(xdrs, cpp, LASTUNSIGNED))
618 		return (TRUE);
619 	return (FALSE);
620 }
621