1 /* $NetBSD: xdr_rec.c,v 1.18 2000/07/06 03:10:35 christos 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 #if defined(LIBC_SCCS) && !defined(lint)
35 static char *sccsid2 = "@(#)xdr_rec.c 1.21 87/08/11 Copyr 1984 Sun Micro";
36 static char *sccsid = "@(#)xdr_rec.c 2.2 88/08/01 4.0 RPCSRC";
37 #endif
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40
41 /*
42 * xdr_rec.c, Implements TCP/IP based XDR streams with a "record marking"
43 * layer above tcp (for rpc's use).
44 *
45 * These routines interface XDRSTREAMS to a tcp/ip connection.
46 * There is a record marking layer between the xdr stream
47 * and the tcp transport level. A record is composed on one or more
48 * record fragments. A record fragment is a thirty-two bit header followed
49 * by n bytes of data, where n is contained in the header. The header
50 * is represented as a htonl(u_long). Thegh order bit encodes
51 * whether or not the fragment is the last fragment of the record
52 * (1 => fragment is last, 0 => more fragments to follow.
53 * The other 31 bits encode the byte length of the fragment.
54 */
55
56 #include "namespace.h"
57 #include <sys/types.h>
58
59 #include <netinet/in.h>
60
61 #include <err.h>
62 #include <stdio.h>
63 #include <stdlib.h>
64 #include <string.h>
65
66 #include <rpc/types.h>
67 #include <rpc/xdr.h>
68 #include <rpc/auth.h>
69 #include <rpc/svc.h>
70 #include <rpc/clnt.h>
71 #include <sys/stddef.h>
72 #include "un-namespace.h"
73 #include "rpc_com.h"
74
75 static bool_t xdrrec_getlong(XDR *, long *);
76 static bool_t xdrrec_putlong(XDR *, const long *);
77 static bool_t xdrrec_getbytes(XDR *, char *, u_int);
78
79 static bool_t xdrrec_putbytes(XDR *, const char *, u_int);
80 static u_int xdrrec_getpos(XDR *);
81 static bool_t xdrrec_setpos(XDR *, u_int);
82 static int32_t *xdrrec_inline(XDR *, u_int);
83 static void xdrrec_destroy(XDR *);
84
85 static const struct xdr_ops xdrrec_ops = {
86 xdrrec_getlong,
87 xdrrec_putlong,
88 xdrrec_getbytes,
89 xdrrec_putbytes,
90 xdrrec_getpos,
91 xdrrec_setpos,
92 xdrrec_inline,
93 xdrrec_destroy
94 };
95
96 /*
97 * A record is composed of one or more record fragments.
98 * A record fragment is a four-byte header followed by zero to
99 * 2**32-1 bytes. The header is treated as a long unsigned and is
100 * encode/decoded to the network via htonl/ntohl. The low order 31 bits
101 * are a byte count of the fragment. The highest order bit is a boolean:
102 * 1 => this fragment is the last fragment of the record,
103 * 0 => this fragment is followed by more fragment(s).
104 *
105 * The fragment/record machinery is not general; it is constructed to
106 * meet the needs of xdr and rpc based on tcp.
107 */
108
109 #define LAST_FRAG ((u_int32_t)(1U << 31))
110
111 typedef struct rec_strm {
112 char *tcp_handle;
113 /*
114 * out-goung bits
115 */
116 int (*writeit)(void *, void *, int);
117 char *out_base; /* output buffer (points to frag header) */
118 char *out_finger; /* next output position */
119 char *out_boundry; /* data cannot up to this address */
120 u_int32_t *frag_header; /* beginning of curren fragment */
121 bool_t frag_sent; /* true if buffer sent in middle of record */
122 /*
123 * in-coming bits
124 */
125 int (*readit)(void *, void *, int);
126 u_long in_size; /* fixed size of the input buffer */
127 char *in_base;
128 char *in_finger; /* location of next byte to be had */
129 char *in_boundry; /* can read up to this location */
130 long fbtbc; /* fragment bytes to be consumed */
131 bool_t last_frag;
132 u_int sendsize;
133 u_int recvsize;
134
135 bool_t nonblock;
136 bool_t in_haveheader;
137 u_int32_t in_header;
138 char *in_hdrp;
139 int in_hdrlen;
140 int in_reclen;
141 int in_received;
142 int in_maxrec;
143 } RECSTREAM;
144
145 static u_int fix_buf_size(u_int);
146 static bool_t flush_out(RECSTREAM *, bool_t);
147 static bool_t fill_input_buf(RECSTREAM *);
148 static bool_t get_input_bytes(RECSTREAM *, char *, int);
149 static bool_t set_input_fragment(RECSTREAM *);
150 static bool_t skip_input_bytes(RECSTREAM *, long);
151 static bool_t realloc_stream(RECSTREAM *, int);
152
153
154 /*
155 * Create an xdr handle for xdrrec
156 * xdrrec_create fills in xdrs. Sendsize and recvsize are
157 * send and recv buffer sizes (0 => use default).
158 * tcp_handle is an opaque handle that is passed as the first parameter to
159 * the procedures readit and writeit. Readit and writeit are read and
160 * write respectively. They are like the system
161 * calls expect that they take an opaque handle rather than an fd.
162 */
163 void
xdrrec_create(XDR * xdrs,u_int sendsize,u_int recvsize,void * tcp_handle,int (* readit)(void *,void *,int),int (* writeit)(void *,void *,int))164 xdrrec_create(XDR *xdrs, u_int sendsize, u_int recvsize, void *tcp_handle,
165 int (*readit)(void *, void *, int), int (*writeit)(void *, void *, int))
166 /*
167 * XDR *xdrs;
168 * u_int sendsize;
169 * u_int recvsize;
170 * void *tcp_handle;
171 * // like read, but pass it a tcp_handle, not sock
172 * int (*readit)(void *, void *, int);
173 * // like write, but pass it a tcp_handle, not sock
174 * int (*writeit)(void *, void *, int);
175 */
176 {
177 RECSTREAM *rstrm = mem_alloc(sizeof(RECSTREAM));
178
179 if (rstrm == NULL) {
180 warnx("xdrrec_create: out of memory");
181 /*
182 * This is bad. Should rework xdrrec_create to
183 * return a handle, and in this case return NULL
184 */
185 return;
186 }
187 rstrm->sendsize = sendsize = fix_buf_size(sendsize);
188 rstrm->out_base = mem_alloc(rstrm->sendsize);
189 if (rstrm->out_base == NULL) {
190 warnx("xdrrec_create: out of memory");
191 mem_free(rstrm, sizeof(RECSTREAM));
192 return;
193 }
194 rstrm->recvsize = recvsize = fix_buf_size(recvsize);
195 rstrm->in_base = mem_alloc(recvsize);
196 if (rstrm->in_base == NULL) {
197 warnx("xdrrec_create: out of memory");
198 mem_free(rstrm->out_base, sendsize);
199 mem_free(rstrm, sizeof(RECSTREAM));
200 return;
201 }
202 /*
203 * now the rest ...
204 */
205 xdrs->x_ops = &xdrrec_ops;
206 xdrs->x_private = rstrm;
207 rstrm->tcp_handle = tcp_handle;
208 rstrm->readit = readit;
209 rstrm->writeit = writeit;
210 rstrm->out_finger = rstrm->out_boundry = rstrm->out_base;
211 rstrm->frag_header = (u_int32_t *)(void *)rstrm->out_base;
212 rstrm->out_finger += sizeof(u_int32_t);
213 rstrm->out_boundry += sendsize;
214 rstrm->frag_sent = FALSE;
215 rstrm->in_size = recvsize;
216 rstrm->in_boundry = rstrm->in_base;
217 rstrm->in_finger = (rstrm->in_boundry += recvsize);
218 rstrm->fbtbc = 0;
219 rstrm->last_frag = TRUE;
220 rstrm->in_haveheader = FALSE;
221 rstrm->in_hdrlen = 0;
222 rstrm->in_hdrp = (char *)(void *)&rstrm->in_header;
223 rstrm->nonblock = FALSE;
224 rstrm->in_reclen = 0;
225 rstrm->in_received = 0;
226 }
227
228
229 /*
230 * The reoutines defined below are the xdr ops which will go into the
231 * xdr handle filled in by xdrrec_create.
232 */
233
234 static bool_t
xdrrec_getlong(XDR * xdrs,long * lp)235 xdrrec_getlong(XDR *xdrs, long *lp)
236 {
237 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
238 int32_t *buflp = (int32_t *)(void *)(rstrm->in_finger);
239 int32_t mylong;
240
241 /* first try the inline, fast case */
242 if ((rstrm->fbtbc >= sizeof(int32_t)) &&
243 (((long)rstrm->in_boundry - (long)buflp) >= sizeof(int32_t))) {
244 *lp = (long)ntohl((u_int32_t)(*buflp));
245 rstrm->fbtbc -= sizeof(int32_t);
246 rstrm->in_finger += sizeof(int32_t);
247 } else {
248 if (! xdrrec_getbytes(xdrs, (char *)(void *)&mylong,
249 sizeof(int32_t)))
250 return (FALSE);
251 *lp = (long)ntohl((u_int32_t)mylong);
252 }
253 return (TRUE);
254 }
255
256 static bool_t
xdrrec_putlong(XDR * xdrs,const long * lp)257 xdrrec_putlong(XDR *xdrs, const long *lp)
258 {
259 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
260 int32_t *dest_lp = ((int32_t *)(void *)(rstrm->out_finger));
261
262 if ((rstrm->out_finger += sizeof(int32_t)) > rstrm->out_boundry) {
263 /*
264 * this case should almost never happen so the code is
265 * inefficient
266 */
267 rstrm->out_finger -= sizeof(int32_t);
268 rstrm->frag_sent = TRUE;
269 if (! flush_out(rstrm, FALSE))
270 return (FALSE);
271 dest_lp = ((int32_t *)(void *)(rstrm->out_finger));
272 rstrm->out_finger += sizeof(int32_t);
273 }
274 *dest_lp = (int32_t)htonl((u_int32_t)(*lp));
275 return (TRUE);
276 }
277
278 static bool_t /* must manage buffers, fragments, and records */
xdrrec_getbytes(XDR * xdrs,char * addr,u_int len)279 xdrrec_getbytes(XDR *xdrs, char *addr, u_int len)
280 {
281 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
282 int current;
283
284 while (len > 0) {
285 current = (int)rstrm->fbtbc;
286 if (current == 0) {
287 if (rstrm->last_frag)
288 return (FALSE);
289 if (! set_input_fragment(rstrm))
290 return (FALSE);
291 continue;
292 }
293 current = (len < current) ? len : current;
294 if (! get_input_bytes(rstrm, addr, current))
295 return (FALSE);
296 addr += current;
297 rstrm->fbtbc -= current;
298 len -= current;
299 }
300 return (TRUE);
301 }
302
303 static bool_t
xdrrec_putbytes(XDR * xdrs,const char * addr,u_int len)304 xdrrec_putbytes(XDR *xdrs, const char *addr, u_int len)
305 {
306 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
307 size_t current;
308
309 while (len > 0) {
310 current = (size_t)((u_long)rstrm->out_boundry -
311 (u_long)rstrm->out_finger);
312 current = (len < current) ? len : current;
313 memmove(rstrm->out_finger, addr, current);
314 rstrm->out_finger += current;
315 addr += current;
316 len -= current;
317 if (rstrm->out_finger == rstrm->out_boundry) {
318 rstrm->frag_sent = TRUE;
319 if (! flush_out(rstrm, FALSE))
320 return (FALSE);
321 }
322 }
323 return (TRUE);
324 }
325
326 static u_int
xdrrec_getpos(XDR * xdrs)327 xdrrec_getpos(XDR *xdrs)
328 {
329 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
330 off_t pos;
331
332 pos = lseek((int)(u_long)rstrm->tcp_handle, (off_t)0, 1);
333 if (pos == -1)
334 pos = 0;
335 switch (xdrs->x_op) {
336
337 case XDR_ENCODE:
338 pos += rstrm->out_finger - rstrm->out_base;
339 break;
340
341 case XDR_DECODE:
342 pos -= rstrm->in_boundry - rstrm->in_finger;
343 break;
344
345 default:
346 pos = (off_t) -1;
347 break;
348 }
349 return ((u_int) pos);
350 }
351
352 static bool_t
xdrrec_setpos(XDR * xdrs,u_int pos)353 xdrrec_setpos(XDR *xdrs, u_int pos)
354 {
355 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
356 u_int currpos = xdrrec_getpos(xdrs);
357 int delta = currpos - pos;
358 char *newpos;
359
360 if ((int)currpos != -1)
361 switch (xdrs->x_op) {
362
363 case XDR_ENCODE:
364 newpos = rstrm->out_finger - delta;
365 if ((newpos > (char *)(void *)(rstrm->frag_header)) &&
366 (newpos < rstrm->out_boundry)) {
367 rstrm->out_finger = newpos;
368 return (TRUE);
369 }
370 break;
371
372 case XDR_DECODE:
373 newpos = rstrm->in_finger - delta;
374 if ((delta < (int)(rstrm->fbtbc)) &&
375 (newpos <= rstrm->in_boundry) &&
376 (newpos >= rstrm->in_base)) {
377 rstrm->in_finger = newpos;
378 rstrm->fbtbc -= delta;
379 return (TRUE);
380 }
381 break;
382
383 case XDR_FREE:
384 break;
385 }
386 return (FALSE);
387 }
388
389 static int32_t *
xdrrec_inline(XDR * xdrs,u_int len)390 xdrrec_inline(XDR *xdrs, u_int len)
391 {
392 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
393 int32_t *buf = NULL;
394
395 switch (xdrs->x_op) {
396
397 case XDR_ENCODE:
398 if ((rstrm->out_finger + len) <= rstrm->out_boundry) {
399 buf = (int32_t *)(void *)rstrm->out_finger;
400 rstrm->out_finger += len;
401 }
402 break;
403
404 case XDR_DECODE:
405 if ((len <= rstrm->fbtbc) &&
406 ((rstrm->in_finger + len) <= rstrm->in_boundry)) {
407 buf = (int32_t *)(void *)rstrm->in_finger;
408 rstrm->fbtbc -= len;
409 rstrm->in_finger += len;
410 }
411 break;
412
413 case XDR_FREE:
414 break;
415 }
416 return (buf);
417 }
418
419 static void
xdrrec_destroy(XDR * xdrs)420 xdrrec_destroy(XDR *xdrs)
421 {
422 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
423
424 mem_free(rstrm->out_base, rstrm->sendsize);
425 mem_free(rstrm->in_base, rstrm->recvsize);
426 mem_free(rstrm, sizeof(RECSTREAM));
427 }
428
429
430 /*
431 * Exported routines to manage xdr records
432 */
433
434 /*
435 * Before reading (deserializing from the stream, one should always call
436 * this procedure to guarantee proper record alignment.
437 */
438 bool_t
xdrrec_skiprecord(XDR * xdrs)439 xdrrec_skiprecord(XDR *xdrs)
440 {
441 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
442 enum xprt_stat xstat;
443
444 if (rstrm->nonblock) {
445 if (__xdrrec_getrec(xdrs, &xstat, FALSE)) {
446 rstrm->fbtbc = 0;
447 return TRUE;
448 }
449 if (rstrm->in_finger == rstrm->in_boundry &&
450 xstat == XPRT_MOREREQS) {
451 rstrm->fbtbc = 0;
452 return TRUE;
453 }
454 return FALSE;
455 }
456
457 while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) {
458 if (! skip_input_bytes(rstrm, rstrm->fbtbc))
459 return (FALSE);
460 rstrm->fbtbc = 0;
461 if ((! rstrm->last_frag) && (! set_input_fragment(rstrm)))
462 return (FALSE);
463 }
464 rstrm->last_frag = FALSE;
465 return (TRUE);
466 }
467
468 /*
469 * Look ahead function.
470 * Returns TRUE iff there is no more input in the buffer
471 * after consuming the rest of the current record.
472 */
473 bool_t
xdrrec_eof(XDR * xdrs)474 xdrrec_eof(XDR *xdrs)
475 {
476 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
477
478 while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) {
479 if (! skip_input_bytes(rstrm, rstrm->fbtbc))
480 return (TRUE);
481 rstrm->fbtbc = 0;
482 if ((! rstrm->last_frag) && (! set_input_fragment(rstrm)))
483 return (TRUE);
484 }
485 if (rstrm->in_finger == rstrm->in_boundry)
486 return (TRUE);
487 return (FALSE);
488 }
489
490 /*
491 * The client must tell the package when an end-of-record has occurred.
492 * The second paraemters tells whether the record should be flushed to the
493 * (output) tcp stream. (This let's the package support batched or
494 * pipelined procedure calls.) TRUE => immmediate flush to tcp connection.
495 */
496 bool_t
xdrrec_endofrecord(XDR * xdrs,bool_t sendnow)497 xdrrec_endofrecord(XDR *xdrs, bool_t sendnow)
498 {
499 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
500 u_long len; /* fragment length */
501
502 if (sendnow || rstrm->frag_sent ||
503 ((u_long)rstrm->out_finger + sizeof(u_int32_t) >=
504 (u_long)rstrm->out_boundry)) {
505 rstrm->frag_sent = FALSE;
506 return (flush_out(rstrm, TRUE));
507 }
508 len = (u_long)(rstrm->out_finger) - (u_long)(rstrm->frag_header) -
509 sizeof(u_int32_t);
510 *(rstrm->frag_header) = htonl((u_int32_t)len | LAST_FRAG);
511 rstrm->frag_header = (u_int32_t *)(void *)rstrm->out_finger;
512 rstrm->out_finger += sizeof(u_int32_t);
513 return (TRUE);
514 }
515
516 /*
517 * Fill the stream buffer with a record for a non-blocking connection.
518 * Return true if a record is available in the buffer, false if not.
519 */
520 bool_t
__xdrrec_getrec(XDR * xdrs,enum xprt_stat * statp,bool_t expectdata)521 __xdrrec_getrec(XDR *xdrs, enum xprt_stat *statp, bool_t expectdata)
522 {
523 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
524 ssize_t n;
525 int fraglen;
526
527 if (!rstrm->in_haveheader) {
528 n = rstrm->readit(rstrm->tcp_handle, rstrm->in_hdrp,
529 (int)sizeof (rstrm->in_header) - rstrm->in_hdrlen);
530 if (n == 0) {
531 *statp = expectdata ? XPRT_DIED : XPRT_IDLE;
532 return FALSE;
533 }
534 if (n < 0) {
535 *statp = XPRT_DIED;
536 return FALSE;
537 }
538 rstrm->in_hdrp += n;
539 rstrm->in_hdrlen += n;
540 if (rstrm->in_hdrlen < sizeof (rstrm->in_header)) {
541 *statp = XPRT_MOREREQS;
542 return FALSE;
543 }
544 rstrm->in_header = ntohl(rstrm->in_header);
545 fraglen = (int)(rstrm->in_header & ~LAST_FRAG);
546 if (fraglen == 0 || fraglen > rstrm->in_maxrec ||
547 (rstrm->in_reclen + fraglen) > rstrm->in_maxrec) {
548 *statp = XPRT_DIED;
549 return FALSE;
550 }
551 rstrm->in_reclen += fraglen;
552 if (rstrm->in_reclen > rstrm->recvsize)
553 realloc_stream(rstrm, rstrm->in_reclen);
554 if (rstrm->in_header & LAST_FRAG) {
555 rstrm->in_header &= ~LAST_FRAG;
556 rstrm->last_frag = TRUE;
557 }
558 /*
559 * We can only reasonably expect to read once from a
560 * non-blocking stream. Reading the fragment header
561 * may have drained the stream.
562 */
563 expectdata = FALSE;
564 }
565
566 n = rstrm->readit(rstrm->tcp_handle,
567 rstrm->in_base + rstrm->in_received,
568 (rstrm->in_reclen - rstrm->in_received));
569
570 if (n < 0) {
571 *statp = XPRT_DIED;
572 return FALSE;
573 }
574
575 if (n == 0) {
576 *statp = expectdata ? XPRT_DIED : XPRT_IDLE;
577 return FALSE;
578 }
579
580 rstrm->in_received += n;
581
582 if (rstrm->in_received == rstrm->in_reclen) {
583 rstrm->in_haveheader = FALSE;
584 rstrm->in_hdrp = (char *)(void *)&rstrm->in_header;
585 rstrm->in_hdrlen = 0;
586 if (rstrm->last_frag) {
587 rstrm->fbtbc = rstrm->in_reclen;
588 rstrm->in_boundry = rstrm->in_base + rstrm->in_reclen;
589 rstrm->in_finger = rstrm->in_base;
590 rstrm->in_reclen = rstrm->in_received = 0;
591 *statp = XPRT_MOREREQS;
592 return TRUE;
593 }
594 }
595
596 *statp = XPRT_MOREREQS;
597 return FALSE;
598 }
599
600 bool_t
__xdrrec_setnonblock(XDR * xdrs,int maxrec)601 __xdrrec_setnonblock(XDR *xdrs, int maxrec)
602 {
603 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
604
605 rstrm->nonblock = TRUE;
606 if (maxrec == 0)
607 maxrec = rstrm->recvsize;
608 rstrm->in_maxrec = maxrec;
609 return TRUE;
610 }
611
612 /*
613 * Internal useful routines
614 */
615 static bool_t
flush_out(RECSTREAM * rstrm,bool_t eor)616 flush_out(RECSTREAM *rstrm, bool_t eor)
617 {
618 u_int32_t eormask = (eor == TRUE) ? LAST_FRAG : 0;
619 u_int32_t len = (u_int32_t)((u_long)(rstrm->out_finger) -
620 (u_long)(rstrm->frag_header) - sizeof(u_int32_t));
621
622 *(rstrm->frag_header) = htonl(len | eormask);
623 len = (u_int32_t)((u_long)(rstrm->out_finger) -
624 (u_long)(rstrm->out_base));
625 if ((*(rstrm->writeit))(rstrm->tcp_handle, rstrm->out_base, (int)len)
626 != (int)len)
627 return (FALSE);
628 rstrm->frag_header = (u_int32_t *)(void *)rstrm->out_base;
629 rstrm->out_finger = (char *)rstrm->out_base + sizeof(u_int32_t);
630 return (TRUE);
631 }
632
633 static bool_t /* knows nothing about records! Only about input buffers */
fill_input_buf(RECSTREAM * rstrm)634 fill_input_buf(RECSTREAM *rstrm)
635 {
636 char *where;
637 u_int32_t i;
638 int len;
639
640 if (rstrm->nonblock)
641 return FALSE;
642
643 where = rstrm->in_base;
644 i = (u_int32_t)((u_long)rstrm->in_boundry % BYTES_PER_XDR_UNIT);
645 where += i;
646 len = (u_int32_t)(rstrm->in_size - i);
647 if ((len = (*(rstrm->readit))(rstrm->tcp_handle, where, len)) == -1)
648 return (FALSE);
649 rstrm->in_finger = where;
650 where += len;
651 rstrm->in_boundry = where;
652 return (TRUE);
653 }
654
655 static bool_t /* knows nothing about records! Only about input buffers */
get_input_bytes(RECSTREAM * rstrm,char * addr,int len)656 get_input_bytes(RECSTREAM *rstrm, char *addr, int len)
657 {
658 size_t current;
659
660 if (rstrm->nonblock) {
661 if (len > (int)(rstrm->in_boundry - rstrm->in_finger))
662 return FALSE;
663 memcpy(addr, rstrm->in_finger, (size_t)len);
664 rstrm->in_finger += len;
665 return TRUE;
666 }
667
668 while (len > 0) {
669 current = (size_t)((long)rstrm->in_boundry -
670 (long)rstrm->in_finger);
671 if (current == 0) {
672 if (! fill_input_buf(rstrm))
673 return (FALSE);
674 continue;
675 }
676 current = (len < current) ? len : current;
677 memmove(addr, rstrm->in_finger, current);
678 rstrm->in_finger += current;
679 addr += current;
680 len -= current;
681 }
682 return (TRUE);
683 }
684
685 static bool_t /* next two bytes of the input stream are treated as a header */
set_input_fragment(RECSTREAM * rstrm)686 set_input_fragment(RECSTREAM *rstrm)
687 {
688 u_int32_t header;
689
690 if (rstrm->nonblock)
691 return FALSE;
692 if (! get_input_bytes(rstrm, (char *)(void *)&header, sizeof(header)))
693 return (FALSE);
694 header = ntohl(header);
695 rstrm->last_frag = ((header & LAST_FRAG) == 0) ? FALSE : TRUE;
696 /*
697 * Sanity check. Try not to accept wildly incorrect
698 * record sizes. Unfortunately, the only record size
699 * we can positively identify as being 'wildly incorrect'
700 * is zero. Ridiculously large record sizes may look wrong,
701 * but we don't have any way to be certain that they aren't
702 * what the client actually intended to send us.
703 */
704 if (header == 0)
705 return(FALSE);
706 rstrm->fbtbc = header & (~LAST_FRAG);
707 return (TRUE);
708 }
709
710 static bool_t /* consumes input bytes; knows nothing about records! */
skip_input_bytes(RECSTREAM * rstrm,long cnt)711 skip_input_bytes(RECSTREAM *rstrm, long cnt)
712 {
713 u_int32_t current;
714
715 while (cnt > 0) {
716 current = (size_t)((long)rstrm->in_boundry -
717 (long)rstrm->in_finger);
718 if (current == 0) {
719 if (! fill_input_buf(rstrm))
720 return (FALSE);
721 continue;
722 }
723 current = (u_int32_t)((cnt < current) ? cnt : current);
724 rstrm->in_finger += current;
725 cnt -= current;
726 }
727 return (TRUE);
728 }
729
730 static u_int
fix_buf_size(u_int s)731 fix_buf_size(u_int s)
732 {
733
734 if (s < 100)
735 s = 4000;
736 return (RNDUP(s));
737 }
738
739 /*
740 * Reallocate the input buffer for a non-block stream.
741 */
742 static bool_t
realloc_stream(RECSTREAM * rstrm,int size)743 realloc_stream(RECSTREAM *rstrm, int size)
744 {
745 ptrdiff_t diff;
746 char *buf;
747
748 if (size > rstrm->recvsize) {
749 buf = realloc(rstrm->in_base, (size_t)size);
750 if (buf == NULL)
751 return FALSE;
752 diff = buf - rstrm->in_base;
753 rstrm->in_finger += diff;
754 rstrm->in_base = buf;
755 rstrm->in_boundry = buf + size;
756 rstrm->recvsize = size;
757 rstrm->in_size = size;
758 }
759
760 return TRUE;
761 }
762