1 /* $NetBSD: xdr_rec.c,v 1.39 2023/06/16 20:01:20 andvar Exp $ */
2
3 /*
4 * Copyright (c) 2010, Oracle America, Inc.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are
8 * met:
9 *
10 * * Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * * Redistributions in binary form must reproduce the above
13 * copyright notice, this list of conditions and the following
14 * disclaimer in the documentation and/or other materials
15 * provided with the distribution.
16 * * Neither the name of the "Oracle America, Inc." nor the names of its
17 * contributors may be used to endorse or promote products derived
18 * from this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
24 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
25 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
27 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
29 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
30 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34 #include <sys/cdefs.h>
35 #if defined(LIBC_SCCS) && !defined(lint)
36 #if 0
37 static char *sccsid = "@(#)xdr_rec.c 1.21 87/08/11 Copyr 1984 Sun Micro";
38 static char *sccsid = "@(#)xdr_rec.c 2.2 88/08/01 4.0 RPCSRC";
39 #else
40 __RCSID("$NetBSD: xdr_rec.c,v 1.39 2023/06/16 20:01:20 andvar Exp $");
41 #endif
42 #endif
43
44 /*
45 * xdr_rec.c, Implements TCP/IP based XDR streams with a "record marking"
46 * layer above tcp (for rpc's use).
47 *
48 * Copyright (C) 1984, Sun Microsystems, Inc.
49 *
50 * These routines interface XDRSTREAMS to a tcp/ip connection.
51 * There is a record marking layer between the xdr stream
52 * and the tcp transport level. A record is composed on one or more
53 * record fragments. A record fragment is a thirty-two bit header followed
54 * by n bytes of data, where n is contained in the header. The header
55 * is represented as a htonl(u_long). Thegh order bit encodes
56 * whether or not the fragment is the last fragment of the record
57 * (1 => fragment is last, 0 => more fragments to follow.
58 * The other 31 bits encode the byte length of the fragment.
59 */
60
61 #include "namespace.h"
62
63 #include <sys/types.h>
64
65 #include <netinet/in.h>
66
67 #include <assert.h>
68 #include <err.h>
69 #include <stddef.h>
70 #include <stdio.h>
71 #include <stdlib.h>
72 #include <string.h>
73
74 #include <rpc/types.h>
75 #include <rpc/xdr.h>
76 #include <rpc/auth.h>
77 #include <rpc/svc.h>
78 #include <rpc/clnt.h>
79
80 #include "rpc_internal.h"
81
82 #ifdef __weak_alias
83 __weak_alias(xdrrec_create,_xdrrec_create)
84 __weak_alias(xdrrec_endofrecord,_xdrrec_endofrecord)
85 __weak_alias(xdrrec_eof,_xdrrec_eof)
86 __weak_alias(xdrrec_skiprecord,_xdrrec_skiprecord)
87 #endif
88
89 static bool_t xdrrec_getlong(XDR *, long *);
90 static bool_t xdrrec_putlong(XDR *, const long *);
91 static bool_t xdrrec_getbytes(XDR *, char *, u_int);
92
93 static bool_t xdrrec_putbytes(XDR *, const char *, u_int);
94 static u_int xdrrec_getpos(XDR *);
95 static bool_t xdrrec_setpos(XDR *, u_int);
96 static int32_t *xdrrec_inline(XDR *, u_int);
97 static void xdrrec_destroy(XDR *);
98
99 static const struct xdr_ops xdrrec_ops = {
100 xdrrec_getlong,
101 xdrrec_putlong,
102 xdrrec_getbytes,
103 xdrrec_putbytes,
104 xdrrec_getpos,
105 xdrrec_setpos,
106 xdrrec_inline,
107 xdrrec_destroy,
108 NULL, /* xdrrec_control */
109 };
110
111 /*
112 * A record is composed of one or more record fragments.
113 * A record fragment is a four-byte header followed by zero to
114 * 2**32-1 bytes. The header is treated as a long unsigned and is
115 * encode/decoded to the network via htonl/ntohl. The low order 31 bits
116 * are a byte count of the fragment. The highest order bit is a boolean:
117 * 1 => this fragment is the last fragment of the record,
118 * 0 => this fragment is followed by more fragment(s).
119 *
120 * The fragment/record machinery is not general; it is constructed to
121 * meet the needs of xdr and rpc based on tcp.
122 */
123
124 #define LAST_FRAG ((uint32_t)(1U << 31))
125
126 typedef struct rec_strm {
127 char *tcp_handle;
128 /*
129 * out-goung bits
130 */
131 int (*writeit)(char *, char *, int);
132 char *out_base; /* output buffer (points to frag header) */
133 char *out_finger; /* next output position */
134 char *out_boundry; /* data cannot up to this address */
135 uint32_t *frag_header; /* beginning of current fragment */
136 bool_t frag_sent; /* true if buffer sent in middle of record */
137 /*
138 * in-coming bits
139 */
140 int (*readit)(char *, char *, int);
141 u_long in_size; /* fixed size of the input buffer */
142 char *in_base;
143 char *in_finger; /* location of next byte to be had */
144 char *in_boundry; /* can read up to this location */
145 long fbtbc; /* fragment bytes to be consumed */
146 bool_t last_frag;
147 u_int sendsize;
148 u_int recvsize;
149
150 bool_t nonblock;
151 bool_t in_haveheader;
152 uint32_t in_header;
153 char *in_hdrp;
154 int in_hdrlen;
155 int in_reclen;
156 int in_received;
157 int in_maxrec;
158 } RECSTREAM;
159
160 static u_int fix_buf_size(u_int);
161 static bool_t flush_out(RECSTREAM *, bool_t);
162 static bool_t fill_input_buf(RECSTREAM *);
163 static bool_t get_input_bytes(RECSTREAM *, char *, u_int);
164 static bool_t set_input_fragment(RECSTREAM *);
165 static bool_t skip_input_bytes(RECSTREAM *, long);
166 static bool_t realloc_stream(RECSTREAM *, int);
167
168
169 /*
170 * Create an xdr handle for xdrrec
171 * xdrrec_create fills in xdrs. Sendsize and recvsize are
172 * send and recv buffer sizes (0 => use default).
173 * tcp_handle is an opaque handle that is passed as the first parameter to
174 * the procedures readit and writeit. Readit and writeit are read and
175 * write respectively. They are like the system
176 * calls expect that they take an opaque handle rather than an fd.
177 */
178 void
xdrrec_create(XDR * xdrs,u_int sendsize,u_int recvsize,char * tcp_handle,int (* readit)(char *,char *,int),int (* writeit)(char *,char *,int))179 xdrrec_create(
180 XDR *xdrs,
181 u_int sendsize,
182 u_int recvsize,
183 char *tcp_handle,
184 /* like read, but pass it a tcp_handle, not sock */
185 int (*readit)(char *, char *, int),
186 /* like write, but pass it a tcp_handle, not sock */
187 int (*writeit)(char *, char *, int))
188 {
189 RECSTREAM *rstrm = mem_alloc(sizeof(RECSTREAM));
190
191 if (rstrm == NULL) {
192 warn("%s: out of memory", __func__);
193 /*
194 * This is bad. Should rework xdrrec_create to
195 * return a handle, and in this case return NULL
196 */
197 return;
198 }
199
200 rstrm->sendsize = sendsize = fix_buf_size(sendsize);
201 rstrm->out_base = malloc(rstrm->sendsize);
202 if (rstrm->out_base == NULL) {
203 warn("%s: out of memory", __func__);
204 mem_free(rstrm, sizeof(RECSTREAM));
205 return;
206 }
207
208 rstrm->recvsize = recvsize = fix_buf_size(recvsize);
209 rstrm->in_base = malloc(recvsize);
210 if (rstrm->in_base == NULL) {
211 warn("%s: out of memory", __func__);
212 mem_free(rstrm->out_base, sendsize);
213 mem_free(rstrm, sizeof(RECSTREAM));
214 return;
215 }
216 /*
217 * now the rest ...
218 */
219 xdrs->x_ops = &xdrrec_ops;
220 xdrs->x_private = rstrm;
221 rstrm->tcp_handle = tcp_handle;
222 rstrm->readit = readit;
223 rstrm->writeit = writeit;
224 rstrm->out_finger = rstrm->out_boundry = rstrm->out_base;
225 rstrm->frag_header = (uint32_t *)(void *)rstrm->out_base;
226 rstrm->out_finger += sizeof(uint32_t);
227 rstrm->out_boundry += sendsize;
228 rstrm->frag_sent = FALSE;
229 rstrm->in_size = recvsize;
230 rstrm->in_boundry = rstrm->in_base;
231 rstrm->in_finger = (rstrm->in_boundry += recvsize);
232 rstrm->fbtbc = 0;
233 rstrm->last_frag = TRUE;
234 rstrm->in_haveheader = FALSE;
235 rstrm->in_hdrlen = 0;
236 rstrm->in_hdrp = (char *)(void *)&rstrm->in_header;
237 rstrm->nonblock = FALSE;
238 rstrm->in_reclen = 0;
239 rstrm->in_received = 0;
240 }
241
242
243 /*
244 * The reoutines defined below are the xdr ops which will go into the
245 * xdr handle filled in by xdrrec_create.
246 */
247
248 static bool_t
xdrrec_getlong(XDR * xdrs,long * lp)249 xdrrec_getlong(XDR *xdrs, long *lp)
250 {
251 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
252 int32_t *buflp = (int32_t *)(void *)(rstrm->in_finger);
253 int32_t mylong;
254
255 /* first try the inline, fast case */
256 if ((rstrm->fbtbc >= (long)sizeof(int32_t)) &&
257 (((uintptr_t)rstrm->in_boundry - (uintptr_t)buflp) >= sizeof(int32_t))) {
258 *lp = (long)ntohl((uint32_t)(*buflp));
259 rstrm->fbtbc -= sizeof(int32_t);
260 rstrm->in_finger += sizeof(int32_t);
261 } else {
262 if (! xdrrec_getbytes(xdrs, (char *)(void *)&mylong,
263 (u_int)sizeof(int32_t)))
264 return (FALSE);
265 *lp = (long)ntohl((uint32_t)mylong);
266 }
267 return (TRUE);
268 }
269
270 static bool_t
xdrrec_putlong(XDR * xdrs,const long * lp)271 xdrrec_putlong(XDR *xdrs, const long *lp)
272 {
273 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
274 int32_t *dest_lp = ((int32_t *)(void *)(rstrm->out_finger));
275
276 if ((rstrm->out_finger += sizeof(int32_t)) > rstrm->out_boundry) {
277 /*
278 * this case should almost never happen so the code is
279 * inefficient
280 */
281 rstrm->out_finger -= sizeof(int32_t);
282 rstrm->frag_sent = TRUE;
283 if (! flush_out(rstrm, FALSE))
284 return (FALSE);
285 dest_lp = ((int32_t *)(void *)(rstrm->out_finger));
286 rstrm->out_finger += sizeof(int32_t);
287 }
288 *dest_lp = (int32_t)htonl((uint32_t)(*lp));
289 return (TRUE);
290 }
291
292 static bool_t /* must manage buffers, fragments, and records */
xdrrec_getbytes(XDR * xdrs,char * addr,u_int len)293 xdrrec_getbytes(XDR *xdrs, char *addr, u_int len)
294 {
295 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
296 u_int current;
297
298 while (len > 0) {
299 current = (u_int)rstrm->fbtbc;
300 if (current == 0) {
301 if (rstrm->last_frag)
302 return (FALSE);
303 if (! set_input_fragment(rstrm))
304 return (FALSE);
305 continue;
306 }
307 current = (len < current) ? len : current;
308 if (! get_input_bytes(rstrm, addr, current))
309 return (FALSE);
310 addr += current;
311 rstrm->fbtbc -= current;
312 len -= current;
313 }
314 return (TRUE);
315 }
316
317 static bool_t
xdrrec_putbytes(XDR * xdrs,const char * addr,u_int len)318 xdrrec_putbytes(XDR *xdrs, const char *addr, u_int len)
319 {
320 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
321 size_t current;
322
323 while (len > 0) {
324 current = (size_t)((u_long)rstrm->out_boundry -
325 (u_long)rstrm->out_finger);
326 current = (len < current) ? len : current;
327 memmove(rstrm->out_finger, addr, current);
328 rstrm->out_finger += current;
329 addr += current;
330 _DIAGASSERT(__type_fit(u_int, current));
331 len -= (u_int)current;
332 if (rstrm->out_finger == rstrm->out_boundry) {
333 rstrm->frag_sent = TRUE;
334 if (! flush_out(rstrm, FALSE))
335 return (FALSE);
336 }
337 }
338 return (TRUE);
339 }
340
341 static u_int
xdrrec_getpos(XDR * xdrs)342 xdrrec_getpos(XDR *xdrs)
343 {
344 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
345 off_t pos;
346
347 pos = lseek((int)(u_long)rstrm->tcp_handle, (off_t)0, 1);
348 if (pos != -1)
349 switch (xdrs->x_op) {
350
351 case XDR_ENCODE:
352 pos += rstrm->out_finger - rstrm->out_base;
353 break;
354
355 case XDR_DECODE:
356 pos -= rstrm->in_boundry - rstrm->in_finger;
357 break;
358
359 default:
360 pos = (off_t) -1;
361 break;
362 }
363 return ((u_int) pos);
364 }
365
366 static bool_t
xdrrec_setpos(XDR * xdrs,u_int pos)367 xdrrec_setpos(XDR *xdrs, u_int pos)
368 {
369 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
370 u_int currpos = xdrrec_getpos(xdrs);
371 int delta = currpos - pos;
372 char *newpos;
373
374 if ((int)currpos != -1)
375 switch (xdrs->x_op) {
376
377 case XDR_ENCODE:
378 newpos = rstrm->out_finger - delta;
379 if ((newpos > (char *)(void *)(rstrm->frag_header)) &&
380 (newpos < rstrm->out_boundry)) {
381 rstrm->out_finger = newpos;
382 return (TRUE);
383 }
384 break;
385
386 case XDR_DECODE:
387 newpos = rstrm->in_finger - delta;
388 if ((delta < (int)(rstrm->fbtbc)) &&
389 (newpos <= rstrm->in_boundry) &&
390 (newpos >= rstrm->in_base)) {
391 rstrm->in_finger = newpos;
392 rstrm->fbtbc -= delta;
393 return (TRUE);
394 }
395 break;
396
397 case XDR_FREE:
398 break;
399 }
400 return (FALSE);
401 }
402
403 static int32_t *
xdrrec_inline(XDR * xdrs,u_int len)404 xdrrec_inline(XDR *xdrs, u_int len)
405 {
406 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
407 int32_t *buf = NULL;
408
409 switch (xdrs->x_op) {
410
411 case XDR_ENCODE:
412 if ((rstrm->out_finger + len) <= rstrm->out_boundry) {
413 buf = (int32_t *)(void *)rstrm->out_finger;
414 rstrm->out_finger += len;
415 }
416 break;
417
418 case XDR_DECODE:
419 if ((len <= (u_int)rstrm->fbtbc) &&
420 ((rstrm->in_finger + len) <= rstrm->in_boundry)) {
421 buf = (int32_t *)(void *)rstrm->in_finger;
422 rstrm->fbtbc -= len;
423 rstrm->in_finger += len;
424 }
425 break;
426
427 case XDR_FREE:
428 break;
429 }
430 return (buf);
431 }
432
433 static void
xdrrec_destroy(XDR * xdrs)434 xdrrec_destroy(XDR *xdrs)
435 {
436 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
437
438 mem_free(rstrm->out_base, rstrm->sendsize);
439 mem_free(rstrm->in_base, rstrm->recvsize);
440 mem_free(rstrm, sizeof(RECSTREAM));
441 }
442
443
444 /*
445 * Exported routines to manage xdr records
446 */
447
448 /*
449 * Before reading (deserializing from the stream, one should always call
450 * this procedure to guarantee proper record alignment.
451 */
452 bool_t
xdrrec_skiprecord(XDR * xdrs)453 xdrrec_skiprecord(XDR *xdrs)
454 {
455 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
456 enum xprt_stat xstat;
457
458 if (rstrm->nonblock) {
459 if (__xdrrec_getrec(xdrs, &xstat, FALSE)) {
460 rstrm->fbtbc = 0;
461 return TRUE;
462 }
463 if (rstrm->in_finger == rstrm->in_boundry &&
464 xstat == XPRT_MOREREQS) {
465 rstrm->fbtbc = 0;
466 return TRUE;
467 }
468 return FALSE;
469 }
470 while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) {
471 if (! skip_input_bytes(rstrm, rstrm->fbtbc))
472 return (FALSE);
473 rstrm->fbtbc = 0;
474 if ((! rstrm->last_frag) && (! set_input_fragment(rstrm)))
475 return (FALSE);
476 }
477 rstrm->last_frag = FALSE;
478 return (TRUE);
479 }
480
481 /*
482 * Look ahead function.
483 * Returns TRUE iff there is no more input in the buffer
484 * after consuming the rest of the current record.
485 */
486 bool_t
xdrrec_eof(XDR * xdrs)487 xdrrec_eof(XDR *xdrs)
488 {
489 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
490
491 while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) {
492 if (!skip_input_bytes(rstrm, rstrm->fbtbc))
493 return (TRUE);
494 rstrm->fbtbc = 0;
495 if ((!rstrm->last_frag) && (!set_input_fragment(rstrm)))
496 return (TRUE);
497 }
498 if (rstrm->in_finger == rstrm->in_boundry)
499 return (TRUE);
500 return (FALSE);
501 }
502
503 /*
504 * The client must tell the package when an end-of-record has occurred.
505 * The second paraemters tells whether the record should be flushed to the
506 * (output) tcp stream. (This let's the package support batched or
507 * pipelined procedure calls.) TRUE => immmediate flush to tcp connection.
508 */
509 bool_t
xdrrec_endofrecord(XDR * xdrs,int sendnow)510 xdrrec_endofrecord(XDR *xdrs, int sendnow)
511 {
512 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
513 u_long len; /* fragment length */
514
515 if (sendnow || rstrm->frag_sent ||
516 ((u_long)rstrm->out_finger + sizeof(uint32_t) >=
517 (u_long)rstrm->out_boundry)) {
518 rstrm->frag_sent = FALSE;
519 return (flush_out(rstrm, TRUE));
520 }
521 len = (u_long)(rstrm->out_finger) - (u_long)(rstrm->frag_header) -
522 sizeof(uint32_t);
523 *(rstrm->frag_header) = htonl((uint32_t)len | LAST_FRAG);
524 rstrm->frag_header = (uint32_t *)(void *)rstrm->out_finger;
525 rstrm->out_finger += sizeof(uint32_t);
526 return (TRUE);
527 }
528
529 /*
530 * Fill the stream buffer with a record for a non-blocking connection.
531 * Return true if a record is available in the buffer, false if not.
532 */
533 bool_t
__xdrrec_getrec(XDR * xdrs,enum xprt_stat * statp,bool_t expectdata)534 __xdrrec_getrec(XDR *xdrs, enum xprt_stat *statp, bool_t expectdata)
535 {
536 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
537 ssize_t n;
538 int fraglen;
539
540 if (!rstrm->in_haveheader) {
541 n = rstrm->readit(rstrm->tcp_handle, rstrm->in_hdrp,
542 (int)sizeof (rstrm->in_header) - rstrm->in_hdrlen);
543 if (n == 0) {
544 *statp = expectdata ? XPRT_DIED : XPRT_IDLE;
545 return FALSE;
546 }
547 if (n < 0) {
548 *statp = XPRT_DIED;
549 return FALSE;
550 }
551 rstrm->in_hdrp += n;
552 _DIAGASSERT(__type_fit(int, n));
553 rstrm->in_hdrlen += (int)n;
554 if (rstrm->in_hdrlen < (int)sizeof(rstrm->in_header)) {
555 *statp = XPRT_MOREREQS;
556 return FALSE;
557 }
558 rstrm->in_header = ntohl(rstrm->in_header);
559 fraglen = (int)(rstrm->in_header & ~LAST_FRAG);
560 if (fraglen == 0 || fraglen > rstrm->in_maxrec ||
561 (rstrm->in_reclen + fraglen) > rstrm->in_maxrec) {
562 *statp = XPRT_DIED;
563 return FALSE;
564 }
565 rstrm->in_reclen += fraglen;
566 if ((u_int)rstrm->in_reclen > rstrm->recvsize) {
567 if (!realloc_stream(rstrm, rstrm->in_reclen)) {
568 *statp = XPRT_DIED;
569 return FALSE;
570 }
571 }
572 if (rstrm->in_header & LAST_FRAG) {
573 rstrm->in_header &= ~LAST_FRAG;
574 rstrm->last_frag = TRUE;
575 }
576 }
577
578 n = rstrm->readit(rstrm->tcp_handle,
579 rstrm->in_base + rstrm->in_received,
580 (rstrm->in_reclen - rstrm->in_received));
581
582 if (n < 0) {
583 *statp = XPRT_DIED;
584 return FALSE;
585 }
586
587 if (n == 0) {
588 *statp = expectdata ? XPRT_DIED : XPRT_IDLE;
589 return FALSE;
590 }
591
592 _DIAGASSERT(__type_fit(int, n));
593 rstrm->in_received += (int)n;
594
595 if (rstrm->in_received == rstrm->in_reclen) {
596 rstrm->in_haveheader = FALSE;
597 rstrm->in_hdrp = (char *)(void *)&rstrm->in_header;
598 rstrm->in_hdrlen = 0;
599 if (rstrm->last_frag) {
600 rstrm->fbtbc = rstrm->in_reclen;
601 rstrm->in_boundry = rstrm->in_base + rstrm->in_reclen;
602 rstrm->in_finger = rstrm->in_base;
603 rstrm->in_reclen = rstrm->in_received = 0;
604 *statp = XPRT_MOREREQS;
605 return TRUE;
606 }
607 }
608
609 *statp = XPRT_MOREREQS;
610 return FALSE;
611 }
612
613 bool_t
__xdrrec_setnonblock(XDR * xdrs,int maxrec)614 __xdrrec_setnonblock(XDR *xdrs, int maxrec)
615 {
616 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
617
618 rstrm->nonblock = TRUE;
619 if (maxrec == 0)
620 maxrec = rstrm->recvsize;
621 rstrm->in_maxrec = maxrec;
622 return TRUE;
623 }
624
625
626 /*
627 * Internal useful routines
628 */
629 static bool_t
flush_out(RECSTREAM * rstrm,bool_t eor)630 flush_out(RECSTREAM *rstrm, bool_t eor)
631 {
632 uint32_t eormask = (eor == TRUE) ? LAST_FRAG : 0;
633 uint32_t len = (uint32_t)((u_long)(rstrm->out_finger) -
634 (u_long)(rstrm->frag_header) - sizeof(uint32_t));
635
636 *(rstrm->frag_header) = htonl(len | eormask);
637 len = (uint32_t)((u_long)(rstrm->out_finger) -
638 (u_long)(rstrm->out_base));
639 if ((*(rstrm->writeit))(rstrm->tcp_handle, rstrm->out_base, (int)len)
640 != (int)len)
641 return (FALSE);
642 rstrm->frag_header = (uint32_t *)(void *)rstrm->out_base;
643 rstrm->out_finger = (char *)rstrm->out_base + sizeof(uint32_t);
644 return (TRUE);
645 }
646
647 static bool_t /* knows nothing about records! Only about input buffers */
fill_input_buf(RECSTREAM * rstrm)648 fill_input_buf(RECSTREAM *rstrm)
649 {
650 char *where;
651 uint32_t i;
652 int len;
653
654 if (rstrm->nonblock)
655 return FALSE;
656 where = rstrm->in_base;
657 i = (uint32_t)((u_long)rstrm->in_boundry % BYTES_PER_XDR_UNIT);
658 where += i;
659 len = (uint32_t)(rstrm->in_size - i);
660 if ((len = (*(rstrm->readit))(rstrm->tcp_handle, where, len)) == -1)
661 return (FALSE);
662 rstrm->in_finger = where;
663 where += len;
664 rstrm->in_boundry = where;
665 return (TRUE);
666 }
667
668 static bool_t /* knows nothing about records! Only about input buffers */
get_input_bytes(RECSTREAM * rstrm,char * addr,u_int len)669 get_input_bytes(RECSTREAM *rstrm, char *addr, u_int len)
670 {
671 u_int current;
672
673 if (rstrm->nonblock) {
674 if (len > ((uintptr_t)rstrm->in_boundry - (uintptr_t)rstrm->in_finger))
675 return FALSE;
676 memcpy(addr, rstrm->in_finger, len);
677 rstrm->in_finger += len;
678 return TRUE;
679 }
680
681 while (len > 0) {
682 uintptr_t d = ((uintptr_t)rstrm->in_boundry -
683 (uintptr_t)rstrm->in_finger);
684 _DIAGASSERT(__type_fit(u_int, d));
685 current = (u_int)d;
686 if (current == 0) {
687 if (! fill_input_buf(rstrm))
688 return (FALSE);
689 continue;
690 }
691 current = (len < current) ? len : current;
692 memmove(addr, rstrm->in_finger, current);
693 rstrm->in_finger += current;
694 addr += current;
695 len -= current;
696 }
697 return (TRUE);
698 }
699
700 static bool_t /* next two bytes of the input stream are treated as a header */
set_input_fragment(RECSTREAM * rstrm)701 set_input_fragment(RECSTREAM *rstrm)
702 {
703 uint32_t header;
704
705 if (rstrm->nonblock)
706 return FALSE;
707 if (! get_input_bytes(rstrm, (char *)(void *)&header,
708 (u_int)sizeof(header)))
709 return (FALSE);
710 header = ntohl(header);
711 rstrm->last_frag = ((header & LAST_FRAG) == 0) ? FALSE : TRUE;
712 /*
713 * Sanity check. Try not to accept wildly incorrect
714 * record sizes. Unfortunately, the only record size
715 * we can positively identify as being 'wildly incorrect'
716 * is zero. Ridiculously large record sizes may look wrong,
717 * but we don't have any way to be certain that they aren't
718 * what the client actually intended to send us.
719 */
720 if (header == 0)
721 return(FALSE);
722 rstrm->fbtbc = header & (~LAST_FRAG);
723 return (TRUE);
724 }
725
726 static bool_t /* consumes input bytes; knows nothing about records! */
skip_input_bytes(RECSTREAM * rstrm,long cnt)727 skip_input_bytes(RECSTREAM *rstrm, long cnt)
728 {
729 uint32_t current;
730
731 while (cnt > 0) {
732 current = (uint32_t)((long)rstrm->in_boundry -
733 (long)rstrm->in_finger);
734 if (current == 0) {
735 if (! fill_input_buf(rstrm))
736 return (FALSE);
737 continue;
738 }
739 current = ((uint32_t)cnt < current) ? (uint32_t)cnt : current;
740 rstrm->in_finger += current;
741 cnt -= current;
742 }
743 return (TRUE);
744 }
745
746 static u_int
fix_buf_size(u_int s)747 fix_buf_size(u_int s)
748 {
749
750 if (s < 100)
751 s = 4000;
752 return (RNDUP(s));
753 }
754
755 /*
756 * Reallocate the input buffer for a non-block stream.
757 */
758 static bool_t
realloc_stream(RECSTREAM * rstrm,int size)759 realloc_stream(RECSTREAM *rstrm, int size)
760 {
761 ptrdiff_t diff;
762 char *buf;
763
764 if ((u_int)size > rstrm->recvsize) {
765 buf = realloc(rstrm->in_base, (size_t)size);
766 if (buf == NULL)
767 return FALSE;
768 diff = buf - rstrm->in_base;
769 rstrm->in_finger += diff;
770 rstrm->in_base = buf;
771 rstrm->in_boundry = buf + size;
772 rstrm->recvsize = size;
773 rstrm->in_size = size;
774 }
775
776 return TRUE;
777 }
778