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 /*
322 * XXX: xdrrec operates on a TCP stream and doesn't keep record of how many
323 * bytes were sent/received overall. Thus, the XDR_GETPOS() and XDR_SETPOS()
324 * can operate only within small internal buffer. So far, the limited set of
325 * consumers of this xdr are fine with that. It also seems that methods are
326 * never called in the XDR_DECODE mode.
327 */
328 static u_int
xdrrec_getpos(XDR * xdrs)329 xdrrec_getpos(XDR *xdrs)
330 {
331 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
332 ptrdiff_t pos;
333
334 switch (xdrs->x_op) {
335 case XDR_ENCODE:
336 pos = rstrm->out_finger - rstrm->out_base;
337 break;
338
339 case XDR_DECODE:
340 pos = rstrm->in_finger - rstrm->in_base;
341 break;
342
343 case XDR_FREE:
344 pos = -1;
345 break;
346 }
347 return ((u_int) pos);
348 }
349
350 static bool_t
xdrrec_setpos(XDR * xdrs,u_int pos)351 xdrrec_setpos(XDR *xdrs, u_int pos)
352 {
353 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
354 u_int currpos = xdrrec_getpos(xdrs);
355 int delta = currpos - pos;
356 char *newpos;
357
358 switch (xdrs->x_op) {
359 case XDR_ENCODE:
360 newpos = rstrm->out_finger - delta;
361 if ((newpos > (char *)(void *)(rstrm->frag_header)) &&
362 (newpos < rstrm->out_boundry)) {
363 rstrm->out_finger = newpos;
364 return (TRUE);
365 }
366 break;
367
368 case XDR_DECODE:
369 newpos = rstrm->in_finger - delta;
370 if ((delta < (int)(rstrm->fbtbc)) &&
371 (newpos <= rstrm->in_boundry) &&
372 (newpos >= rstrm->in_base)) {
373 rstrm->in_finger = newpos;
374 rstrm->fbtbc -= delta;
375 return (TRUE);
376 }
377 break;
378
379 case XDR_FREE:
380 break;
381 }
382 return (FALSE);
383 }
384
385 static int32_t *
xdrrec_inline(XDR * xdrs,u_int len)386 xdrrec_inline(XDR *xdrs, u_int len)
387 {
388 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
389 int32_t *buf = NULL;
390
391 switch (xdrs->x_op) {
392
393 case XDR_ENCODE:
394 if ((rstrm->out_finger + len) <= rstrm->out_boundry) {
395 buf = (int32_t *)(void *)rstrm->out_finger;
396 rstrm->out_finger += len;
397 }
398 break;
399
400 case XDR_DECODE:
401 if ((len <= rstrm->fbtbc) &&
402 ((rstrm->in_finger + len) <= rstrm->in_boundry)) {
403 buf = (int32_t *)(void *)rstrm->in_finger;
404 rstrm->fbtbc -= len;
405 rstrm->in_finger += len;
406 }
407 break;
408
409 case XDR_FREE:
410 break;
411 }
412 return (buf);
413 }
414
415 static void
xdrrec_destroy(XDR * xdrs)416 xdrrec_destroy(XDR *xdrs)
417 {
418 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
419
420 mem_free(rstrm->out_base, rstrm->sendsize);
421 mem_free(rstrm->in_base, rstrm->recvsize);
422 mem_free(rstrm, sizeof(RECSTREAM));
423 }
424
425
426 /*
427 * Exported routines to manage xdr records
428 */
429
430 /*
431 * Before reading (deserializing from the stream, one should always call
432 * this procedure to guarantee proper record alignment.
433 */
434 bool_t
xdrrec_skiprecord(XDR * xdrs)435 xdrrec_skiprecord(XDR *xdrs)
436 {
437 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
438 enum xprt_stat xstat;
439
440 if (rstrm->nonblock) {
441 if (__xdrrec_getrec(xdrs, &xstat, FALSE)) {
442 rstrm->fbtbc = 0;
443 return TRUE;
444 }
445 if (rstrm->in_finger == rstrm->in_boundry &&
446 xstat == XPRT_MOREREQS) {
447 rstrm->fbtbc = 0;
448 return TRUE;
449 }
450 return FALSE;
451 }
452
453 while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) {
454 if (! skip_input_bytes(rstrm, rstrm->fbtbc))
455 return (FALSE);
456 rstrm->fbtbc = 0;
457 if ((! rstrm->last_frag) && (! set_input_fragment(rstrm)))
458 return (FALSE);
459 }
460 rstrm->last_frag = FALSE;
461 return (TRUE);
462 }
463
464 /*
465 * Look ahead function.
466 * Returns TRUE iff there is no more input in the buffer
467 * after consuming the rest of the current record.
468 */
469 bool_t
xdrrec_eof(XDR * xdrs)470 xdrrec_eof(XDR *xdrs)
471 {
472 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
473
474 while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) {
475 if (! skip_input_bytes(rstrm, rstrm->fbtbc))
476 return (TRUE);
477 rstrm->fbtbc = 0;
478 if ((! rstrm->last_frag) && (! set_input_fragment(rstrm)))
479 return (TRUE);
480 }
481 if (rstrm->in_finger == rstrm->in_boundry)
482 return (TRUE);
483 return (FALSE);
484 }
485
486 /*
487 * The client must tell the package when an end-of-record has occurred.
488 * The second parameters tells whether the record should be flushed to the
489 * (output) tcp stream. (This let's the package support batched or
490 * pipelined procedure calls.) TRUE => immediate flush to tcp connection.
491 */
492 bool_t
xdrrec_endofrecord(XDR * xdrs,bool_t sendnow)493 xdrrec_endofrecord(XDR *xdrs, bool_t sendnow)
494 {
495 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
496 u_long len; /* fragment length */
497
498 if (sendnow || rstrm->frag_sent ||
499 ((u_long)rstrm->out_finger + sizeof(u_int32_t) >=
500 (u_long)rstrm->out_boundry)) {
501 rstrm->frag_sent = FALSE;
502 return (flush_out(rstrm, TRUE));
503 }
504 len = (u_long)(rstrm->out_finger) - (u_long)(rstrm->frag_header) -
505 sizeof(u_int32_t);
506 *(rstrm->frag_header) = htonl((u_int32_t)len | LAST_FRAG);
507 rstrm->frag_header = (u_int32_t *)(void *)rstrm->out_finger;
508 rstrm->out_finger += sizeof(u_int32_t);
509 return (TRUE);
510 }
511
512 /*
513 * Fill the stream buffer with a record for a non-blocking connection.
514 * Return true if a record is available in the buffer, false if not.
515 */
516 bool_t
__xdrrec_getrec(XDR * xdrs,enum xprt_stat * statp,bool_t expectdata)517 __xdrrec_getrec(XDR *xdrs, enum xprt_stat *statp, bool_t expectdata)
518 {
519 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
520 ssize_t n;
521 int fraglen;
522
523 if (!rstrm->in_haveheader) {
524 n = rstrm->readit(rstrm->tcp_handle, rstrm->in_hdrp,
525 (int)sizeof (rstrm->in_header) - rstrm->in_hdrlen);
526 if (n == 0) {
527 *statp = expectdata ? XPRT_DIED : XPRT_IDLE;
528 return FALSE;
529 }
530 if (n < 0) {
531 *statp = XPRT_DIED;
532 return FALSE;
533 }
534 rstrm->in_hdrp += n;
535 rstrm->in_hdrlen += n;
536 if (rstrm->in_hdrlen < sizeof (rstrm->in_header)) {
537 *statp = XPRT_MOREREQS;
538 return FALSE;
539 }
540 rstrm->in_header = ntohl(rstrm->in_header);
541 fraglen = (int)(rstrm->in_header & ~LAST_FRAG);
542 if (fraglen == 0 || fraglen > rstrm->in_maxrec ||
543 (rstrm->in_reclen + fraglen) > rstrm->in_maxrec) {
544 *statp = XPRT_DIED;
545 return FALSE;
546 }
547 rstrm->in_reclen += fraglen;
548 if (rstrm->in_reclen > rstrm->recvsize)
549 realloc_stream(rstrm, rstrm->in_reclen);
550 if (rstrm->in_header & LAST_FRAG) {
551 rstrm->in_header &= ~LAST_FRAG;
552 rstrm->last_frag = TRUE;
553 }
554 /*
555 * We can only reasonably expect to read once from a
556 * non-blocking stream. Reading the fragment header
557 * may have drained the stream.
558 */
559 expectdata = FALSE;
560 }
561
562 n = rstrm->readit(rstrm->tcp_handle,
563 rstrm->in_base + rstrm->in_received,
564 (rstrm->in_reclen - rstrm->in_received));
565
566 if (n < 0) {
567 *statp = XPRT_DIED;
568 return FALSE;
569 }
570
571 if (n == 0) {
572 *statp = expectdata ? XPRT_DIED : XPRT_IDLE;
573 return FALSE;
574 }
575
576 rstrm->in_received += n;
577
578 if (rstrm->in_received == rstrm->in_reclen) {
579 rstrm->in_haveheader = FALSE;
580 rstrm->in_hdrp = (char *)(void *)&rstrm->in_header;
581 rstrm->in_hdrlen = 0;
582 if (rstrm->last_frag) {
583 rstrm->fbtbc = rstrm->in_reclen;
584 rstrm->in_boundry = rstrm->in_base + rstrm->in_reclen;
585 rstrm->in_finger = rstrm->in_base;
586 rstrm->in_reclen = rstrm->in_received = 0;
587 *statp = XPRT_MOREREQS;
588 return TRUE;
589 }
590 }
591
592 *statp = XPRT_MOREREQS;
593 return FALSE;
594 }
595
596 bool_t
__xdrrec_setnonblock(XDR * xdrs,int maxrec)597 __xdrrec_setnonblock(XDR *xdrs, int maxrec)
598 {
599 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
600
601 rstrm->nonblock = TRUE;
602 if (maxrec == 0)
603 maxrec = rstrm->recvsize;
604 rstrm->in_maxrec = maxrec;
605 return TRUE;
606 }
607
608 /*
609 * Internal useful routines
610 */
611 static bool_t
flush_out(RECSTREAM * rstrm,bool_t eor)612 flush_out(RECSTREAM *rstrm, bool_t eor)
613 {
614 u_int32_t eormask = (eor == TRUE) ? LAST_FRAG : 0;
615 u_int32_t len = (u_int32_t)((u_long)(rstrm->out_finger) -
616 (u_long)(rstrm->frag_header) - sizeof(u_int32_t));
617
618 *(rstrm->frag_header) = htonl(len | eormask);
619 len = (u_int32_t)((u_long)(rstrm->out_finger) -
620 (u_long)(rstrm->out_base));
621 if ((*(rstrm->writeit))(rstrm->tcp_handle, rstrm->out_base, (int)len)
622 != (int)len)
623 return (FALSE);
624 rstrm->frag_header = (u_int32_t *)(void *)rstrm->out_base;
625 rstrm->out_finger = (char *)rstrm->out_base + sizeof(u_int32_t);
626 return (TRUE);
627 }
628
629 static bool_t /* knows nothing about records! Only about input buffers */
fill_input_buf(RECSTREAM * rstrm)630 fill_input_buf(RECSTREAM *rstrm)
631 {
632 char *where;
633 u_int32_t i;
634 int len;
635
636 if (rstrm->nonblock)
637 return FALSE;
638
639 where = rstrm->in_base;
640 i = (u_int32_t)((u_long)rstrm->in_boundry % BYTES_PER_XDR_UNIT);
641 where += i;
642 len = (u_int32_t)(rstrm->in_size - i);
643 if ((len = (*(rstrm->readit))(rstrm->tcp_handle, where, len)) == -1)
644 return (FALSE);
645 rstrm->in_finger = where;
646 where += len;
647 rstrm->in_boundry = where;
648 return (TRUE);
649 }
650
651 static bool_t /* knows nothing about records! Only about input buffers */
get_input_bytes(RECSTREAM * rstrm,char * addr,int len)652 get_input_bytes(RECSTREAM *rstrm, char *addr, int len)
653 {
654 size_t current;
655
656 if (rstrm->nonblock) {
657 if (len > (int)(rstrm->in_boundry - rstrm->in_finger))
658 return FALSE;
659 memcpy(addr, rstrm->in_finger, (size_t)len);
660 rstrm->in_finger += len;
661 return TRUE;
662 }
663
664 while (len > 0) {
665 current = (size_t)((long)rstrm->in_boundry -
666 (long)rstrm->in_finger);
667 if (current == 0) {
668 if (! fill_input_buf(rstrm))
669 return (FALSE);
670 continue;
671 }
672 current = (len < current) ? len : current;
673 memmove(addr, rstrm->in_finger, current);
674 rstrm->in_finger += current;
675 addr += current;
676 len -= current;
677 }
678 return (TRUE);
679 }
680
681 static bool_t /* next two bytes of the input stream are treated as a header */
set_input_fragment(RECSTREAM * rstrm)682 set_input_fragment(RECSTREAM *rstrm)
683 {
684 u_int32_t header;
685
686 if (rstrm->nonblock)
687 return FALSE;
688 if (! get_input_bytes(rstrm, (char *)(void *)&header, sizeof(header)))
689 return (FALSE);
690 header = ntohl(header);
691 rstrm->last_frag = ((header & LAST_FRAG) == 0) ? FALSE : TRUE;
692 /*
693 * Sanity check. Try not to accept wildly incorrect
694 * record sizes. Unfortunately, the only record size
695 * we can positively identify as being 'wildly incorrect'
696 * is zero. Ridiculously large record sizes may look wrong,
697 * but we don't have any way to be certain that they aren't
698 * what the client actually intended to send us.
699 */
700 if (header == 0)
701 return(FALSE);
702 rstrm->fbtbc = header & (~LAST_FRAG);
703 return (TRUE);
704 }
705
706 static bool_t /* consumes input bytes; knows nothing about records! */
skip_input_bytes(RECSTREAM * rstrm,long cnt)707 skip_input_bytes(RECSTREAM *rstrm, long cnt)
708 {
709 u_int32_t current;
710
711 while (cnt > 0) {
712 current = (size_t)((long)rstrm->in_boundry -
713 (long)rstrm->in_finger);
714 if (current == 0) {
715 if (! fill_input_buf(rstrm))
716 return (FALSE);
717 continue;
718 }
719 current = (u_int32_t)((cnt < current) ? cnt : current);
720 rstrm->in_finger += current;
721 cnt -= current;
722 }
723 return (TRUE);
724 }
725
726 static u_int
fix_buf_size(u_int s)727 fix_buf_size(u_int s)
728 {
729
730 if (s < 100)
731 s = 4000;
732 return (RNDUP(s));
733 }
734
735 /*
736 * Reallocate the input buffer for a non-block stream.
737 */
738 static bool_t
realloc_stream(RECSTREAM * rstrm,int size)739 realloc_stream(RECSTREAM *rstrm, int size)
740 {
741 ptrdiff_t diff;
742 char *buf;
743
744 if (size > rstrm->recvsize) {
745 buf = realloc(rstrm->in_base, (size_t)size);
746 if (buf == NULL)
747 return FALSE;
748 diff = buf - rstrm->in_base;
749 rstrm->in_finger += diff;
750 rstrm->in_base = buf;
751 rstrm->in_boundry = buf + size;
752 rstrm->recvsize = size;
753 rstrm->in_size = size;
754 }
755
756 return TRUE;
757 }
758