1 /* $NetBSD: xdr_rec.c,v 1.18 2000/07/06 03:10:35 christos Exp $ */
2
3 /*-
4 * SPDX-License-Identifier: BSD-3-Clause
5 *
6 * Copyright (c) 2010, Oracle America, Inc.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions are
10 * met:
11 *
12 * * Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * * Redistributions in binary form must reproduce the above
15 * copyright notice, this list of conditions and the following
16 * disclaimer in the documentation and/or other materials
17 * provided with the distribution.
18 * * Neither the name of the "Oracle America, Inc." nor the names of its
19 * contributors may be used to endorse or promote products derived
20 * from this software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
25 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
26 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
27 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
29 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
31 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
33 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 */
35
36 /*
37 * xdr_rec.c, Implements TCP/IP based XDR streams with a "record marking"
38 * layer above tcp (for rpc's use).
39 *
40 * These routines interface XDRSTREAMS to a tcp/ip connection.
41 * There is a record marking layer between the xdr stream
42 * and the tcp transport level. A record is composed on one or more
43 * record fragments. A record fragment is a thirty-two bit header followed
44 * by n bytes of data, where n is contained in the header. The header
45 * is represented as a htonl(u_long). Thegh order bit encodes
46 * whether or not the fragment is the last fragment of the record
47 * (1 => fragment is last, 0 => more fragments to follow.
48 * The other 31 bits encode the byte length of the fragment.
49 */
50
51 #include "namespace.h"
52 #include <sys/types.h>
53
54 #include <netinet/in.h>
55
56 #include <err.h>
57 #include <stdio.h>
58 #include <stdlib.h>
59 #include <string.h>
60
61 #include <rpc/types.h>
62 #include <rpc/xdr.h>
63 #include <rpc/auth.h>
64 #include <rpc/svc.h>
65 #include <rpc/clnt.h>
66 #include <sys/stddef.h>
67 #include "un-namespace.h"
68 #include "rpc_com.h"
69
70 static bool_t xdrrec_getlong(XDR *, long *);
71 static bool_t xdrrec_putlong(XDR *, const long *);
72 static bool_t xdrrec_getbytes(XDR *, char *, u_int);
73
74 static bool_t xdrrec_putbytes(XDR *, const char *, u_int);
75 static u_int xdrrec_getpos(XDR *);
76 static bool_t xdrrec_setpos(XDR *, u_int);
77 static int32_t *xdrrec_inline(XDR *, u_int);
78 static void xdrrec_destroy(XDR *);
79
80 static const struct xdr_ops xdrrec_ops = {
81 xdrrec_getlong,
82 xdrrec_putlong,
83 xdrrec_getbytes,
84 xdrrec_putbytes,
85 xdrrec_getpos,
86 xdrrec_setpos,
87 xdrrec_inline,
88 xdrrec_destroy
89 };
90
91 /*
92 * A record is composed of one or more record fragments.
93 * A record fragment is a four-byte header followed by zero to
94 * 2**32-1 bytes. The header is treated as a long unsigned and is
95 * encode/decoded to the network via htonl/ntohl. The low order 31 bits
96 * are a byte count of the fragment. The highest order bit is a boolean:
97 * 1 => this fragment is the last fragment of the record,
98 * 0 => this fragment is followed by more fragment(s).
99 *
100 * The fragment/record machinery is not general; it is constructed to
101 * meet the needs of xdr and rpc based on tcp.
102 */
103
104 #define LAST_FRAG ((u_int32_t)(1U << 31))
105
106 typedef struct rec_strm {
107 char *tcp_handle;
108 /*
109 * out-goung bits
110 */
111 int (*writeit)(void *, void *, int);
112 char *out_base; /* output buffer (points to frag header) */
113 char *out_finger; /* next output position */
114 char *out_boundry; /* data cannot up to this address */
115 u_int32_t *frag_header; /* beginning of current fragment */
116 bool_t frag_sent; /* true if buffer sent in middle of record */
117 /*
118 * in-coming bits
119 */
120 int (*readit)(void *, void *, int);
121 u_long in_size; /* fixed size of the input buffer */
122 char *in_base;
123 char *in_finger; /* location of next byte to be had */
124 char *in_boundry; /* can read up to this location */
125 long fbtbc; /* fragment bytes to be consumed */
126 bool_t last_frag;
127 u_int sendsize;
128 u_int recvsize;
129
130 bool_t nonblock;
131 bool_t in_haveheader;
132 u_int32_t in_header;
133 char *in_hdrp;
134 int in_hdrlen;
135 int in_reclen;
136 int in_received;
137 int in_maxrec;
138 } RECSTREAM;
139
140 static u_int fix_buf_size(u_int);
141 static bool_t flush_out(RECSTREAM *, bool_t);
142 static bool_t fill_input_buf(RECSTREAM *);
143 static bool_t get_input_bytes(RECSTREAM *, char *, int);
144 static bool_t set_input_fragment(RECSTREAM *);
145 static bool_t skip_input_bytes(RECSTREAM *, long);
146 static bool_t realloc_stream(RECSTREAM *, int);
147
148
149 /*
150 * Create an xdr handle for xdrrec
151 * xdrrec_create fills in xdrs. Sendsize and recvsize are
152 * send and recv buffer sizes (0 => use default).
153 * tcp_handle is an opaque handle that is passed as the first parameter to
154 * the procedures readit and writeit. Readit and writeit are read and
155 * write respectively. They are like the system
156 * calls expect that they take an opaque handle rather than an fd.
157 */
158 void
xdrrec_create(XDR * xdrs,u_int sendsize,u_int recvsize,void * tcp_handle,int (* readit)(void *,void *,int),int (* writeit)(void *,void *,int))159 xdrrec_create(XDR *xdrs, u_int sendsize, u_int recvsize, void *tcp_handle,
160 int (*readit)(void *, void *, int), int (*writeit)(void *, void *, int))
161 /*
162 * XDR *xdrs;
163 * u_int sendsize;
164 * u_int recvsize;
165 * void *tcp_handle;
166 * // like read, but pass it a tcp_handle, not sock
167 * int (*readit)(void *, void *, int);
168 * // like write, but pass it a tcp_handle, not sock
169 * int (*writeit)(void *, void *, int);
170 */
171 {
172 RECSTREAM *rstrm = mem_alloc(sizeof(RECSTREAM));
173
174 if (rstrm == NULL) {
175 warnx("xdrrec_create: out of memory");
176 /*
177 * This is bad. Should rework xdrrec_create to
178 * return a handle, and in this case return NULL
179 */
180 return;
181 }
182 rstrm->sendsize = sendsize = fix_buf_size(sendsize);
183 rstrm->out_base = mem_alloc(rstrm->sendsize);
184 if (rstrm->out_base == NULL) {
185 warnx("xdrrec_create: out of memory");
186 mem_free(rstrm, sizeof(RECSTREAM));
187 return;
188 }
189 rstrm->recvsize = recvsize = fix_buf_size(recvsize);
190 rstrm->in_base = mem_alloc(recvsize);
191 if (rstrm->in_base == NULL) {
192 warnx("xdrrec_create: out of memory");
193 mem_free(rstrm->out_base, sendsize);
194 mem_free(rstrm, sizeof(RECSTREAM));
195 return;
196 }
197 /*
198 * now the rest ...
199 */
200 xdrs->x_ops = &xdrrec_ops;
201 xdrs->x_private = rstrm;
202 rstrm->tcp_handle = tcp_handle;
203 rstrm->readit = readit;
204 rstrm->writeit = writeit;
205 rstrm->out_finger = rstrm->out_boundry = rstrm->out_base;
206 rstrm->frag_header = (u_int32_t *)(void *)rstrm->out_base;
207 rstrm->out_finger += sizeof(u_int32_t);
208 rstrm->out_boundry += sendsize;
209 rstrm->frag_sent = FALSE;
210 rstrm->in_size = recvsize;
211 rstrm->in_boundry = rstrm->in_base;
212 rstrm->in_finger = (rstrm->in_boundry += recvsize);
213 rstrm->fbtbc = 0;
214 rstrm->last_frag = TRUE;
215 rstrm->in_haveheader = FALSE;
216 rstrm->in_hdrlen = 0;
217 rstrm->in_hdrp = (char *)(void *)&rstrm->in_header;
218 rstrm->nonblock = FALSE;
219 rstrm->in_reclen = 0;
220 rstrm->in_received = 0;
221 }
222
223
224 /*
225 * The routines defined below are the xdr ops which will go into the
226 * xdr handle filled in by xdrrec_create.
227 */
228
229 static bool_t
xdrrec_getlong(XDR * xdrs,long * lp)230 xdrrec_getlong(XDR *xdrs, long *lp)
231 {
232 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
233 int32_t *buflp = (int32_t *)(void *)(rstrm->in_finger);
234 int32_t mylong;
235
236 /* first try the inline, fast case */
237 if ((rstrm->fbtbc >= sizeof(int32_t)) &&
238 (((long)rstrm->in_boundry - (long)buflp) >= sizeof(int32_t))) {
239 *lp = (long)ntohl((u_int32_t)(*buflp));
240 rstrm->fbtbc -= sizeof(int32_t);
241 rstrm->in_finger += sizeof(int32_t);
242 } else {
243 if (! xdrrec_getbytes(xdrs, (char *)(void *)&mylong,
244 sizeof(int32_t)))
245 return (FALSE);
246 *lp = (long)ntohl((u_int32_t)mylong);
247 }
248 return (TRUE);
249 }
250
251 static bool_t
xdrrec_putlong(XDR * xdrs,const long * lp)252 xdrrec_putlong(XDR *xdrs, const long *lp)
253 {
254 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
255 int32_t *dest_lp = ((int32_t *)(void *)(rstrm->out_finger));
256
257 if ((rstrm->out_finger += sizeof(int32_t)) > rstrm->out_boundry) {
258 /*
259 * this case should almost never happen so the code is
260 * inefficient
261 */
262 rstrm->out_finger -= sizeof(int32_t);
263 rstrm->frag_sent = TRUE;
264 if (! flush_out(rstrm, FALSE))
265 return (FALSE);
266 dest_lp = ((int32_t *)(void *)(rstrm->out_finger));
267 rstrm->out_finger += sizeof(int32_t);
268 }
269 *dest_lp = (int32_t)htonl((u_int32_t)(*lp));
270 return (TRUE);
271 }
272
273 static bool_t /* must manage buffers, fragments, and records */
xdrrec_getbytes(XDR * xdrs,char * addr,u_int len)274 xdrrec_getbytes(XDR *xdrs, char *addr, u_int len)
275 {
276 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
277 int current;
278
279 while (len > 0) {
280 current = (int)rstrm->fbtbc;
281 if (current == 0) {
282 if (rstrm->last_frag)
283 return (FALSE);
284 if (! set_input_fragment(rstrm))
285 return (FALSE);
286 continue;
287 }
288 current = (len < current) ? len : current;
289 if (! get_input_bytes(rstrm, addr, current))
290 return (FALSE);
291 addr += current;
292 rstrm->fbtbc -= current;
293 len -= current;
294 }
295 return (TRUE);
296 }
297
298 static bool_t
xdrrec_putbytes(XDR * xdrs,const char * addr,u_int len)299 xdrrec_putbytes(XDR *xdrs, const char *addr, u_int len)
300 {
301 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
302 size_t current;
303
304 while (len > 0) {
305 current = (size_t)((u_long)rstrm->out_boundry -
306 (u_long)rstrm->out_finger);
307 current = (len < current) ? len : current;
308 memmove(rstrm->out_finger, addr, current);
309 rstrm->out_finger += current;
310 addr += current;
311 len -= current;
312 if (rstrm->out_finger == rstrm->out_boundry) {
313 rstrm->frag_sent = TRUE;
314 if (! flush_out(rstrm, FALSE))
315 return (FALSE);
316 }
317 }
318 return (TRUE);
319 }
320
321 static u_int
xdrrec_getpos(XDR * xdrs)322 xdrrec_getpos(XDR *xdrs)
323 {
324 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
325 off_t pos;
326
327 pos = lseek((int)(u_long)rstrm->tcp_handle, (off_t)0, 1);
328 if (pos == -1)
329 pos = 0;
330 switch (xdrs->x_op) {
331
332 case XDR_ENCODE:
333 pos += rstrm->out_finger - rstrm->out_base;
334 break;
335
336 case XDR_DECODE:
337 pos -= rstrm->in_boundry - rstrm->in_finger;
338 break;
339
340 default:
341 pos = (off_t) -1;
342 break;
343 }
344 return ((u_int) pos);
345 }
346
347 static bool_t
xdrrec_setpos(XDR * xdrs,u_int pos)348 xdrrec_setpos(XDR *xdrs, u_int pos)
349 {
350 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
351 u_int currpos = xdrrec_getpos(xdrs);
352 int delta = currpos - pos;
353 char *newpos;
354
355 if ((int)currpos != -1)
356 switch (xdrs->x_op) {
357
358 case XDR_ENCODE:
359 newpos = rstrm->out_finger - delta;
360 if ((newpos > (char *)(void *)(rstrm->frag_header)) &&
361 (newpos < rstrm->out_boundry)) {
362 rstrm->out_finger = newpos;
363 return (TRUE);
364 }
365 break;
366
367 case XDR_DECODE:
368 newpos = rstrm->in_finger - delta;
369 if ((delta < (int)(rstrm->fbtbc)) &&
370 (newpos <= rstrm->in_boundry) &&
371 (newpos >= rstrm->in_base)) {
372 rstrm->in_finger = newpos;
373 rstrm->fbtbc -= delta;
374 return (TRUE);
375 }
376 break;
377
378 case XDR_FREE:
379 break;
380 }
381 return (FALSE);
382 }
383
384 static int32_t *
xdrrec_inline(XDR * xdrs,u_int len)385 xdrrec_inline(XDR *xdrs, u_int len)
386 {
387 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
388 int32_t *buf = NULL;
389
390 switch (xdrs->x_op) {
391
392 case XDR_ENCODE:
393 if ((rstrm->out_finger + len) <= rstrm->out_boundry) {
394 buf = (int32_t *)(void *)rstrm->out_finger;
395 rstrm->out_finger += len;
396 }
397 break;
398
399 case XDR_DECODE:
400 if ((len <= rstrm->fbtbc) &&
401 ((rstrm->in_finger + len) <= rstrm->in_boundry)) {
402 buf = (int32_t *)(void *)rstrm->in_finger;
403 rstrm->fbtbc -= len;
404 rstrm->in_finger += len;
405 }
406 break;
407
408 case XDR_FREE:
409 break;
410 }
411 return (buf);
412 }
413
414 static void
xdrrec_destroy(XDR * xdrs)415 xdrrec_destroy(XDR *xdrs)
416 {
417 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
418
419 mem_free(rstrm->out_base, rstrm->sendsize);
420 mem_free(rstrm->in_base, rstrm->recvsize);
421 mem_free(rstrm, sizeof(RECSTREAM));
422 }
423
424
425 /*
426 * Exported routines to manage xdr records
427 */
428
429 /*
430 * Before reading (deserializing from the stream, one should always call
431 * this procedure to guarantee proper record alignment.
432 */
433 bool_t
xdrrec_skiprecord(XDR * xdrs)434 xdrrec_skiprecord(XDR *xdrs)
435 {
436 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
437 enum xprt_stat xstat;
438
439 if (rstrm->nonblock) {
440 if (__xdrrec_getrec(xdrs, &xstat, FALSE)) {
441 rstrm->fbtbc = 0;
442 return TRUE;
443 }
444 if (rstrm->in_finger == rstrm->in_boundry &&
445 xstat == XPRT_MOREREQS) {
446 rstrm->fbtbc = 0;
447 return TRUE;
448 }
449 return FALSE;
450 }
451
452 while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) {
453 if (! skip_input_bytes(rstrm, rstrm->fbtbc))
454 return (FALSE);
455 rstrm->fbtbc = 0;
456 if ((! rstrm->last_frag) && (! set_input_fragment(rstrm)))
457 return (FALSE);
458 }
459 rstrm->last_frag = FALSE;
460 return (TRUE);
461 }
462
463 /*
464 * Look ahead function.
465 * Returns TRUE iff there is no more input in the buffer
466 * after consuming the rest of the current record.
467 */
468 bool_t
xdrrec_eof(XDR * xdrs)469 xdrrec_eof(XDR *xdrs)
470 {
471 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
472
473 while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) {
474 if (! skip_input_bytes(rstrm, rstrm->fbtbc))
475 return (TRUE);
476 rstrm->fbtbc = 0;
477 if ((! rstrm->last_frag) && (! set_input_fragment(rstrm)))
478 return (TRUE);
479 }
480 if (rstrm->in_finger == rstrm->in_boundry)
481 return (TRUE);
482 return (FALSE);
483 }
484
485 /*
486 * The client must tell the package when an end-of-record has occurred.
487 * The second parameters tells whether the record should be flushed to the
488 * (output) tcp stream. (This let's the package support batched or
489 * pipelined procedure calls.) TRUE => immediate flush to tcp connection.
490 */
491 bool_t
xdrrec_endofrecord(XDR * xdrs,bool_t sendnow)492 xdrrec_endofrecord(XDR *xdrs, bool_t sendnow)
493 {
494 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
495 u_long len; /* fragment length */
496
497 if (sendnow || rstrm->frag_sent ||
498 ((u_long)rstrm->out_finger + sizeof(u_int32_t) >=
499 (u_long)rstrm->out_boundry)) {
500 rstrm->frag_sent = FALSE;
501 return (flush_out(rstrm, TRUE));
502 }
503 len = (u_long)(rstrm->out_finger) - (u_long)(rstrm->frag_header) -
504 sizeof(u_int32_t);
505 *(rstrm->frag_header) = htonl((u_int32_t)len | LAST_FRAG);
506 rstrm->frag_header = (u_int32_t *)(void *)rstrm->out_finger;
507 rstrm->out_finger += sizeof(u_int32_t);
508 return (TRUE);
509 }
510
511 /*
512 * Fill the stream buffer with a record for a non-blocking connection.
513 * Return true if a record is available in the buffer, false if not.
514 */
515 bool_t
__xdrrec_getrec(XDR * xdrs,enum xprt_stat * statp,bool_t expectdata)516 __xdrrec_getrec(XDR *xdrs, enum xprt_stat *statp, bool_t expectdata)
517 {
518 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
519 ssize_t n;
520 int fraglen;
521
522 if (!rstrm->in_haveheader) {
523 n = rstrm->readit(rstrm->tcp_handle, rstrm->in_hdrp,
524 (int)sizeof (rstrm->in_header) - rstrm->in_hdrlen);
525 if (n == 0) {
526 *statp = expectdata ? XPRT_DIED : XPRT_IDLE;
527 return FALSE;
528 }
529 if (n < 0) {
530 *statp = XPRT_DIED;
531 return FALSE;
532 }
533 rstrm->in_hdrp += n;
534 rstrm->in_hdrlen += n;
535 if (rstrm->in_hdrlen < sizeof (rstrm->in_header)) {
536 *statp = XPRT_MOREREQS;
537 return FALSE;
538 }
539 rstrm->in_header = ntohl(rstrm->in_header);
540 fraglen = (int)(rstrm->in_header & ~LAST_FRAG);
541 if (fraglen == 0 || fraglen > rstrm->in_maxrec ||
542 (rstrm->in_reclen + fraglen) > rstrm->in_maxrec) {
543 *statp = XPRT_DIED;
544 return FALSE;
545 }
546 rstrm->in_reclen += fraglen;
547 if (rstrm->in_reclen > rstrm->recvsize)
548 realloc_stream(rstrm, rstrm->in_reclen);
549 if (rstrm->in_header & LAST_FRAG) {
550 rstrm->in_header &= ~LAST_FRAG;
551 rstrm->last_frag = TRUE;
552 }
553 /*
554 * We can only reasonably expect to read once from a
555 * non-blocking stream. Reading the fragment header
556 * may have drained the stream.
557 */
558 expectdata = FALSE;
559 }
560
561 n = rstrm->readit(rstrm->tcp_handle,
562 rstrm->in_base + rstrm->in_received,
563 (rstrm->in_reclen - rstrm->in_received));
564
565 if (n < 0) {
566 *statp = XPRT_DIED;
567 return FALSE;
568 }
569
570 if (n == 0) {
571 *statp = expectdata ? XPRT_DIED : XPRT_IDLE;
572 return FALSE;
573 }
574
575 rstrm->in_received += n;
576
577 if (rstrm->in_received == rstrm->in_reclen) {
578 rstrm->in_haveheader = FALSE;
579 rstrm->in_hdrp = (char *)(void *)&rstrm->in_header;
580 rstrm->in_hdrlen = 0;
581 if (rstrm->last_frag) {
582 rstrm->fbtbc = rstrm->in_reclen;
583 rstrm->in_boundry = rstrm->in_base + rstrm->in_reclen;
584 rstrm->in_finger = rstrm->in_base;
585 rstrm->in_reclen = rstrm->in_received = 0;
586 *statp = XPRT_MOREREQS;
587 return TRUE;
588 }
589 }
590
591 *statp = XPRT_MOREREQS;
592 return FALSE;
593 }
594
595 bool_t
__xdrrec_setnonblock(XDR * xdrs,int maxrec)596 __xdrrec_setnonblock(XDR *xdrs, int maxrec)
597 {
598 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
599
600 rstrm->nonblock = TRUE;
601 if (maxrec == 0)
602 maxrec = rstrm->recvsize;
603 rstrm->in_maxrec = maxrec;
604 return TRUE;
605 }
606
607 /*
608 * Internal useful routines
609 */
610 static bool_t
flush_out(RECSTREAM * rstrm,bool_t eor)611 flush_out(RECSTREAM *rstrm, bool_t eor)
612 {
613 u_int32_t eormask = (eor == TRUE) ? LAST_FRAG : 0;
614 u_int32_t len = (u_int32_t)((u_long)(rstrm->out_finger) -
615 (u_long)(rstrm->frag_header) - sizeof(u_int32_t));
616
617 *(rstrm->frag_header) = htonl(len | eormask);
618 len = (u_int32_t)((u_long)(rstrm->out_finger) -
619 (u_long)(rstrm->out_base));
620 if ((*(rstrm->writeit))(rstrm->tcp_handle, rstrm->out_base, (int)len)
621 != (int)len)
622 return (FALSE);
623 rstrm->frag_header = (u_int32_t *)(void *)rstrm->out_base;
624 rstrm->out_finger = (char *)rstrm->out_base + sizeof(u_int32_t);
625 return (TRUE);
626 }
627
628 static bool_t /* knows nothing about records! Only about input buffers */
fill_input_buf(RECSTREAM * rstrm)629 fill_input_buf(RECSTREAM *rstrm)
630 {
631 char *where;
632 u_int32_t i;
633 int len;
634
635 if (rstrm->nonblock)
636 return FALSE;
637
638 where = rstrm->in_base;
639 i = (u_int32_t)((u_long)rstrm->in_boundry % BYTES_PER_XDR_UNIT);
640 where += i;
641 len = (u_int32_t)(rstrm->in_size - i);
642 if ((len = (*(rstrm->readit))(rstrm->tcp_handle, where, len)) == -1)
643 return (FALSE);
644 rstrm->in_finger = where;
645 where += len;
646 rstrm->in_boundry = where;
647 return (TRUE);
648 }
649
650 static bool_t /* knows nothing about records! Only about input buffers */
get_input_bytes(RECSTREAM * rstrm,char * addr,int len)651 get_input_bytes(RECSTREAM *rstrm, char *addr, int len)
652 {
653 size_t current;
654
655 if (rstrm->nonblock) {
656 if (len > (int)(rstrm->in_boundry - rstrm->in_finger))
657 return FALSE;
658 memcpy(addr, rstrm->in_finger, (size_t)len);
659 rstrm->in_finger += len;
660 return TRUE;
661 }
662
663 while (len > 0) {
664 current = (size_t)((long)rstrm->in_boundry -
665 (long)rstrm->in_finger);
666 if (current == 0) {
667 if (! fill_input_buf(rstrm))
668 return (FALSE);
669 continue;
670 }
671 current = (len < current) ? len : current;
672 memmove(addr, rstrm->in_finger, current);
673 rstrm->in_finger += current;
674 addr += current;
675 len -= current;
676 }
677 return (TRUE);
678 }
679
680 static bool_t /* next two bytes of the input stream are treated as a header */
set_input_fragment(RECSTREAM * rstrm)681 set_input_fragment(RECSTREAM *rstrm)
682 {
683 u_int32_t header;
684
685 if (rstrm->nonblock)
686 return FALSE;
687 if (! get_input_bytes(rstrm, (char *)(void *)&header, sizeof(header)))
688 return (FALSE);
689 header = ntohl(header);
690 rstrm->last_frag = ((header & LAST_FRAG) == 0) ? FALSE : TRUE;
691 /*
692 * Sanity check. Try not to accept wildly incorrect
693 * record sizes. Unfortunately, the only record size
694 * we can positively identify as being 'wildly incorrect'
695 * is zero. Ridiculously large record sizes may look wrong,
696 * but we don't have any way to be certain that they aren't
697 * what the client actually intended to send us.
698 */
699 if (header == 0)
700 return(FALSE);
701 rstrm->fbtbc = header & (~LAST_FRAG);
702 return (TRUE);
703 }
704
705 static bool_t /* consumes input bytes; knows nothing about records! */
skip_input_bytes(RECSTREAM * rstrm,long cnt)706 skip_input_bytes(RECSTREAM *rstrm, long cnt)
707 {
708 u_int32_t current;
709
710 while (cnt > 0) {
711 current = (size_t)((long)rstrm->in_boundry -
712 (long)rstrm->in_finger);
713 if (current == 0) {
714 if (! fill_input_buf(rstrm))
715 return (FALSE);
716 continue;
717 }
718 current = (u_int32_t)((cnt < current) ? cnt : current);
719 rstrm->in_finger += current;
720 cnt -= current;
721 }
722 return (TRUE);
723 }
724
725 static u_int
fix_buf_size(u_int s)726 fix_buf_size(u_int s)
727 {
728
729 if (s < 100)
730 s = 4000;
731 return (RNDUP(s));
732 }
733
734 /*
735 * Reallocate the input buffer for a non-block stream.
736 */
737 static bool_t
realloc_stream(RECSTREAM * rstrm,int size)738 realloc_stream(RECSTREAM *rstrm, int size)
739 {
740 ptrdiff_t diff;
741 char *buf;
742
743 if (size > rstrm->recvsize) {
744 buf = realloc(rstrm->in_base, (size_t)size);
745 if (buf == NULL)
746 return FALSE;
747 diff = buf - rstrm->in_base;
748 rstrm->in_finger += diff;
749 rstrm->in_base = buf;
750 rstrm->in_boundry = buf + size;
751 rstrm->recvsize = size;
752 rstrm->in_size = size;
753 }
754
755 return TRUE;
756 }
757