source: rtems/cpukit/librpc/src/xdr/xdr_rec.c @ f26145b

4.104.114.84.95
Last change on this file since f26145b was df49c60, checked in by Joel Sherrill <joel.sherrill@…>, on 06/12/00 at 15:00:15

Merged from 4.5.0-beta3a

  • Property mode set to 100644
File size: 16.0 KB
Line 
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#if defined(LIBC_SCCS) && !defined(lint)
30/*static char *sccsid = "from: @(#)xdr_rec.c 1.21 87/08/11 Copyr 1984 Sun Micro";*/
31/*static char *sccsid = "from: @(#)xdr_rec.c    2.2 88/08/01 4.0 RPCSRC";*/
32static char *rcsid = "$FreeBSD: src/lib/libc/xdr/xdr_rec.c,v 1.12 2000/01/19 06:12:32 wpaul Exp $";
33#endif
34
35/*
36 * xdr_rec.c, Implements TCP/IP based XDR streams with a "record marking"
37 * layer above tcp (for rpc's use).
38 *
39 * Copyright (C) 1984, Sun Microsystems, Inc.
40 *
41 * These routines interface XDRSTREAMS to a tcp/ip connection.
42 * There is a record marking layer between the xdr stream
43 * and the tcp transport level.  A record is composed on one or more
44 * record fragments.  A record fragment is a thirty-two bit header followed
45 * by n bytes of data, where n is contained in the header.  The header
46 * is represented as a htonl(u_long).  Thegh order bit encodes
47 * whether or not the fragment is the last fragment of the record
48 * (1 => fragment is last, 0 => more fragments to follow.
49 * The other 31 bits encode the byte length of the fragment.
50 */
51
52#include <stdio.h>
53#include <stdlib.h>
54#include <string.h>
55#include <rpc/types.h>
56#include <rpc/xdr.h>
57#include <netinet/in.h>
58#include <unistd.h>   /* for lseek() */
59
60static u_int    fix_buf_size();
61static bool_t   flush_out();
62static bool_t   get_input_bytes();
63static bool_t   set_input_fragment();
64static bool_t   skip_input_bytes();
65
66static bool_t   xdrrec_getlong();
67static bool_t   xdrrec_putlong();
68static bool_t   xdrrec_getbytes();
69static bool_t   xdrrec_putbytes();
70static u_int    xdrrec_getpos();
71static bool_t   xdrrec_setpos();
72static int32_t *xdrrec_inline();
73static void     xdrrec_destroy();
74
75static struct  xdr_ops xdrrec_ops = {
76        xdrrec_getlong,
77        xdrrec_putlong,
78        xdrrec_getbytes,
79        xdrrec_putbytes,
80        xdrrec_getpos,
81        xdrrec_setpos,
82        xdrrec_inline,
83        xdrrec_destroy
84};
85
86/*
87 * A record is composed of one or more record fragments.
88 * A record fragment is a two-byte header followed by zero to
89 * 2**32-1 bytes.  The header is treated as a long unsigned and is
90 * encode/decoded to the network via htonl/ntohl.  The low order 31 bits
91 * are a byte count of the fragment.  The highest order bit is a boolean:
92 * 1 => this fragment is the last fragment of the record,
93 * 0 => this fragment is followed by more fragment(s).
94 *
95 * The fragment/record machinery is not general;  it is constructed to
96 * meet the needs of xdr and rpc based on tcp.
97 */
98
99#define LAST_FRAG ((u_int32_t)(1 << 31))
100
101typedef struct rec_strm {
102        caddr_t tcp_handle;
103        caddr_t the_buffer;
104        /*
105         * out-goung bits
106         */
107        int (*writeit) __P((caddr_t, caddr_t, int));
108        caddr_t out_base;       /* output buffer (points to frag header) */
109        caddr_t out_finger;     /* next output position */
110        caddr_t out_boundry;    /* data cannot up to this address */
111        u_int32_t *frag_header; /* beginning of current fragment */
112        bool_t frag_sent;       /* true if buffer sent in middle of record */
113        /*
114         * in-coming bits
115         */
116        int (*readit) __P((caddr_t, caddr_t, int));
117        u_long in_size; /* fixed size of the input buffer */
118        caddr_t in_base;
119        caddr_t in_finger;      /* location of next byte to be had */
120        caddr_t in_boundry;     /* can read up to this location */
121        long fbtbc;             /* fragment bytes to be consumed */
122        bool_t last_frag;
123        u_int sendsize;
124        u_int recvsize;
125} RECSTREAM;
126
127
128/*
129 * Create an xdr handle for xdrrec
130 * xdrrec_create fills in xdrs.  Sendsize and recvsize are
131 * send and recv buffer sizes (0 => use default).
132 * tcp_handle is an opaque handle that is passed as the first parameter to
133 * the procedures readit and writeit.  Readit and writeit are read and
134 * write respectively.   They are like the system
135 * calls expect that they take an opaque handle rather than an fd.
136 */
137void
138xdrrec_create(xdrs, sendsize, recvsize, tcp_handle, readit, writeit)
139        register XDR *xdrs;
140        register u_int sendsize;
141        register u_int recvsize;
142        caddr_t tcp_handle;
143        int (*readit)();  /* like read, but pass it a tcp_handle, not sock */
144        int (*writeit)();  /* like write, but pass it a tcp_handle, not sock */
145{
146        register RECSTREAM *rstrm =
147                (RECSTREAM *)mem_alloc(sizeof(RECSTREAM));
148
149        if (rstrm == NULL) {
150                (void)fprintf(stderr, "xdrrec_create: out of memory\n");
151                /*
152                 *  This is bad.  Should rework xdrrec_create to
153                 *  return a handle, and in this case return NULL
154                 */
155                return;
156        }
157        /*
158         * adjust sizes and allocate buffer quad byte aligned
159         */
160        rstrm->sendsize = sendsize = fix_buf_size(sendsize);
161        rstrm->recvsize = recvsize = fix_buf_size(recvsize);
162        rstrm->the_buffer = mem_alloc(sendsize + recvsize + BYTES_PER_XDR_UNIT);
163        if (rstrm->the_buffer == NULL) {
164                (void)fprintf(stderr, "xdrrec_create: out of memory\n");
165                return;
166        }
167        for (rstrm->out_base = rstrm->the_buffer;
168                (u_long)rstrm->out_base % BYTES_PER_XDR_UNIT != 0;
169                rstrm->out_base++);
170        rstrm->in_base = rstrm->out_base + sendsize;
171        /*
172         * now the rest ...
173         */
174        xdrs->x_ops = &xdrrec_ops;
175        xdrs->x_private = (caddr_t)rstrm;
176        rstrm->tcp_handle = tcp_handle;
177        rstrm->readit = readit;
178        rstrm->writeit = writeit;
179        rstrm->out_finger = rstrm->out_boundry = rstrm->out_base;
180        rstrm->frag_header = (u_int32_t *)rstrm->out_base;
181        rstrm->out_finger += sizeof(u_int32_t);
182        rstrm->out_boundry += sendsize;
183        rstrm->frag_sent = FALSE;
184        rstrm->in_size = recvsize;
185        rstrm->in_boundry = rstrm->in_base;
186        rstrm->in_finger = (rstrm->in_boundry += recvsize);
187        rstrm->fbtbc = 0;
188        rstrm->last_frag = TRUE;
189}
190
191
192/*
193 * The reoutines defined below are the xdr ops which will go into the
194 * xdr handle filled in by xdrrec_create.
195 */
196
197static bool_t
198xdrrec_getlong(xdrs, lp)
199        XDR *xdrs;
200        long *lp;
201{
202        register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
203        register int32_t *buflp = (int32_t *)(rstrm->in_finger);
204        int32_t mylong;
205
206        /* first try the inline, fast case */
207        if ((rstrm->fbtbc >= sizeof(int32_t)) &&
208                (((long)rstrm->in_boundry - (long)buflp) >= sizeof(int32_t))) {
209                *lp = (long)ntohl((u_int32_t)(*buflp));
210                rstrm->fbtbc -= sizeof(int32_t);
211                rstrm->in_finger += sizeof(int32_t);
212        } else {
213                if (! xdrrec_getbytes(xdrs, (caddr_t)&mylong, sizeof(int32_t)))
214                        return (FALSE);
215                *lp = (long)ntohl((u_int32_t)mylong);
216        }
217        return (TRUE);
218}
219
220static bool_t
221xdrrec_putlong(xdrs, lp)
222        XDR *xdrs;
223        long *lp;
224{
225        register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
226        register int32_t *dest_lp = ((int32_t *)(rstrm->out_finger));
227
228        if ((rstrm->out_finger += sizeof(int32_t)) > rstrm->out_boundry) {
229                /*
230                 * this case should almost never happen so the code is
231                 * inefficient
232                 */
233                rstrm->out_finger -= sizeof(int32_t);
234                rstrm->frag_sent = TRUE;
235                if (! flush_out(rstrm, FALSE))
236                        return (FALSE);
237                dest_lp = ((int32_t *)(rstrm->out_finger));
238                rstrm->out_finger += sizeof(int32_t);
239        }
240        *dest_lp = (int32_t)htonl((u_int32_t)(*lp));
241        return (TRUE);
242}
243
244static bool_t  /* must manage buffers, fragments, and records */
245xdrrec_getbytes(xdrs, addr, len)
246        XDR *xdrs;
247        register caddr_t addr;
248        register u_int len;
249{
250        register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
251        register int current;
252
253        while (len > 0) {
254                current = rstrm->fbtbc;
255                if (current == 0) {
256                        if (rstrm->last_frag)
257                                return (FALSE);
258                        if (! set_input_fragment(rstrm))
259                                return (FALSE);
260                        continue;
261                }
262                current = (len < current) ? len : current;
263                if (! get_input_bytes(rstrm, addr, current))
264                        return (FALSE);
265                addr += current;
266                rstrm->fbtbc -= current;
267                len -= current;
268        }
269        return (TRUE);
270}
271
272static bool_t
273xdrrec_putbytes(xdrs, addr, len)
274        XDR *xdrs;
275        register caddr_t addr;
276        register u_int len;
277{
278        register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
279        register long current;
280
281        while (len > 0) {
282                current = (u_long)rstrm->out_boundry -
283                        (u_long)rstrm->out_finger;
284                current = (len < current) ? len : current;
285                memcpy(rstrm->out_finger, addr, current);
286                rstrm->out_finger += current;
287                addr += current;
288                len -= current;
289                if (rstrm->out_finger == rstrm->out_boundry) {
290                        rstrm->frag_sent = TRUE;
291                        if (! flush_out(rstrm, FALSE))
292                                return (FALSE);
293                }
294        }
295        return (TRUE);
296}
297
298static u_int
299xdrrec_getpos(xdrs)
300        register XDR *xdrs;
301{
302        register RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
303        register long pos;
304
305        pos = lseek((int)(long)rstrm->tcp_handle, (off_t) 0, 1);
306        if (pos != -1)
307                switch (xdrs->x_op) {
308
309                case XDR_ENCODE:
310                        pos += rstrm->out_finger - rstrm->out_base;
311                        break;
312
313                case XDR_DECODE:
314                        pos -= rstrm->in_boundry - rstrm->in_finger;
315                        break;
316
317                default:
318                        pos = -1;
319                        break;
320                }
321        return ((u_int) pos);
322}
323
324static bool_t
325xdrrec_setpos(xdrs, pos)
326        register XDR *xdrs;
327        u_int pos;
328{
329        register RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
330        u_int currpos = xdrrec_getpos(xdrs);
331        int delta = currpos - pos;
332        caddr_t newpos;
333
334        if ((int)currpos != -1)
335                switch (xdrs->x_op) {
336
337                case XDR_ENCODE:
338                        newpos = rstrm->out_finger - delta;
339                        if ((newpos > (caddr_t)(rstrm->frag_header)) &&
340                                (newpos < rstrm->out_boundry)) {
341                                rstrm->out_finger = newpos;
342                                return (TRUE);
343                        }
344                        break;
345
346                case XDR_DECODE:
347                        newpos = rstrm->in_finger - delta;
348                        if ((delta < (int)(rstrm->fbtbc)) &&
349                                (newpos <= rstrm->in_boundry) &&
350                                (newpos >= rstrm->in_base)) {
351                                rstrm->in_finger = newpos;
352                                rstrm->fbtbc -= delta;
353                                return (TRUE);
354                        }
355                        break;
356                case XDR_FREE:  /* to avoid warning */
357                        break;
358                }
359        return (FALSE);
360}
361
362static int32_t *
363xdrrec_inline(xdrs, len)
364        register XDR *xdrs;
365        int len;
366{
367        register RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
368        int32_t * buf = NULL;
369
370        switch (xdrs->x_op) {
371
372        case XDR_ENCODE:
373                if ((rstrm->out_finger + len) <= rstrm->out_boundry) {
374                        buf = (int32_t *) rstrm->out_finger;
375                        rstrm->out_finger += len;
376                }
377                break;
378
379        case XDR_DECODE:
380                if ((len <= rstrm->fbtbc) &&
381                        ((rstrm->in_finger + len) <= rstrm->in_boundry)) {
382                        buf = (int32_t *) rstrm->in_finger;
383                        rstrm->fbtbc -= len;
384                        rstrm->in_finger += len;
385                }
386                break;
387        case XDR_FREE:  /* to avoid warning */
388                break;
389        }
390        return (buf);
391}
392
393static void
394xdrrec_destroy(xdrs)
395        register XDR *xdrs;
396{
397        register RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
398
399        mem_free(rstrm->the_buffer,
400                rstrm->sendsize + rstrm->recvsize + BYTES_PER_XDR_UNIT);
401        mem_free((caddr_t)rstrm, sizeof(RECSTREAM));
402}
403
404
405/*
406 * Exported routines to manage xdr records
407 */
408
409/*
410 * Before reading (deserializing from the stream, one should always call
411 * this procedure to guarantee proper record alignment.
412 */
413bool_t
414xdrrec_skiprecord(xdrs)
415        XDR *xdrs;
416{
417        register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
418
419        while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) {
420                if (! skip_input_bytes(rstrm, rstrm->fbtbc))
421                        return (FALSE);
422                rstrm->fbtbc = 0;
423                if ((! rstrm->last_frag) && (! set_input_fragment(rstrm)))
424                        return (FALSE);
425        }
426        rstrm->last_frag = FALSE;
427        return (TRUE);
428}
429
430/*
431 * Look ahead fuction.
432 * Returns TRUE iff there is no more input in the buffer
433 * after consuming the rest of the current record.
434 */
435bool_t
436xdrrec_eof(xdrs)
437        XDR *xdrs;
438{
439        register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
440
441        while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) {
442                if (! skip_input_bytes(rstrm, rstrm->fbtbc))
443                        return (TRUE);
444                rstrm->fbtbc = 0;
445                if ((! rstrm->last_frag) && (! set_input_fragment(rstrm)))
446                        return (TRUE);
447        }
448        if (rstrm->in_finger == rstrm->in_boundry)
449                return (TRUE);
450        return (FALSE);
451}
452
453/*
454 * The client must tell the package when an end-of-record has occurred.
455 * The second paraemters tells whether the record should be flushed to the
456 * (output) tcp stream.  (This let's the package support batched or
457 * pipelined procedure calls.)  TRUE => immmediate flush to tcp connection.
458 */
459bool_t
460xdrrec_endofrecord(xdrs, sendnow)
461        XDR *xdrs;
462        bool_t sendnow;
463{
464        register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
465        register u_long len;  /* fragment length */
466
467        if (sendnow || rstrm->frag_sent ||
468                ((u_long)rstrm->out_finger + sizeof(u_int32_t) >=
469                (u_long)rstrm->out_boundry)) {
470                rstrm->frag_sent = FALSE;
471                return (flush_out(rstrm, TRUE));
472        }
473        len = (u_long)(rstrm->out_finger) - (u_long)(rstrm->frag_header) -
474           sizeof(u_int32_t);
475        *(rstrm->frag_header) = htonl((u_long)len | LAST_FRAG);
476        rstrm->frag_header = (u_int32_t *)rstrm->out_finger;
477        rstrm->out_finger += sizeof(u_int32_t);
478        return (TRUE);
479}
480
481
482/*
483 * Internal useful routines
484 */
485static bool_t
486flush_out(rstrm, eor)
487        register RECSTREAM *rstrm;
488        bool_t eor;
489{
490        register u_long eormask = (eor == TRUE) ? LAST_FRAG : 0;
491        register u_int32_t len = (u_long)(rstrm->out_finger) -
492                (u_long)(rstrm->frag_header) - sizeof(u_int32_t);
493
494        *(rstrm->frag_header) = htonl(len | eormask);
495        len = (u_long)(rstrm->out_finger) - (u_long)(rstrm->out_base);
496        if ((*(rstrm->writeit))(rstrm->tcp_handle, rstrm->out_base, (int)len)
497                != (int)len)
498                return (FALSE);
499        rstrm->frag_header = (u_int32_t *)rstrm->out_base;
500        rstrm->out_finger = (caddr_t)rstrm->out_base + sizeof(u_int32_t);
501        return (TRUE);
502}
503
504static bool_t  /* knows nothing about records!  Only about input buffers */
505fill_input_buf(rstrm)
506        register RECSTREAM *rstrm;
507{
508        register caddr_t where;
509        u_long i;
510        register long len;
511
512        where = rstrm->in_base;
513        i = (u_long)rstrm->in_boundry % BYTES_PER_XDR_UNIT;
514        where += i;
515        len = rstrm->in_size - i;
516        if ((len = (*(rstrm->readit))(rstrm->tcp_handle, where, len)) == -1)
517                return (FALSE);
518        rstrm->in_finger = where;
519        where += len;
520        rstrm->in_boundry = where;
521        return (TRUE);
522}
523
524static bool_t  /* knows nothing about records!  Only about input buffers */
525get_input_bytes(rstrm, addr, len)
526        register RECSTREAM *rstrm;
527        register caddr_t addr;
528        register int len;
529{
530        register long current;
531
532        while (len > 0) {
533                current = (long)rstrm->in_boundry - (long)rstrm->in_finger;
534                if (current == 0) {
535                        if (! fill_input_buf(rstrm))
536                                return (FALSE);
537                        continue;
538                }
539                current = (len < current) ? len : current;
540                memcpy(addr, rstrm->in_finger, current);
541                rstrm->in_finger += current;
542                addr += current;
543                len -= current;
544        }
545        return (TRUE);
546}
547
548static bool_t  /* next two bytes of the input stream are treated as a header */
549set_input_fragment(rstrm)
550        register RECSTREAM *rstrm;
551{
552        u_int32_t header;
553
554        if (! get_input_bytes(rstrm, (caddr_t)&header, sizeof(header)))
555                return (FALSE);
556        header = (long)ntohl(header);
557        rstrm->last_frag = ((header & LAST_FRAG) == 0) ? FALSE : TRUE;
558        /*
559         * Sanity check. Try not to accept wildly incorrect
560         * record sizes. Unfortunately, the only record size
561         * we can positively identify as being 'wildly incorrect'
562         * is zero. Ridiculously large record sizes may look wrong,
563         * but we don't have any way to be certain that they aren't
564         * what the client actually intended to send us.
565         */
566        if (header == 0)
567                return(FALSE);
568        rstrm->fbtbc = header & (~LAST_FRAG);
569        return (TRUE);
570}
571
572static bool_t  /* consumes input bytes; knows nothing about records! */
573skip_input_bytes(rstrm, cnt)
574        register RECSTREAM *rstrm;
575        long cnt;
576{
577        register long current;
578
579        while (cnt > 0) {
580                current = (long)rstrm->in_boundry - (long)rstrm->in_finger;
581                if (current == 0) {
582                        if (! fill_input_buf(rstrm))
583                                return (FALSE);
584                        continue;
585                }
586                current = (cnt < current) ? cnt : current;
587                rstrm->in_finger += current;
588                cnt -= current;
589        }
590        return (TRUE);
591}
592
593static u_int
594fix_buf_size(s)
595        register u_int s;
596{
597
598        if (s < 100)
599                s = 4000;
600        return (RNDUP(s));
601}
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