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#if defined(LIBC_SCCS) && !defined(lint) 37static char *sccsid2 = "@(#)xdr_rec.c 1.21 87/08/11 Copyr 1984 Sun Micro"; 38static char *sccsid = "@(#)xdr_rec.c 2.2 88/08/01 4.0 RPCSRC"; 39#endif 40#include <sys/cdefs.h> 41__FBSDID("$FreeBSD$"); 42 43/* 44 * xdr_rec.c, Implements TCP/IP based XDR streams with a "record marking" 45 * layer above tcp (for rpc's use). 46 * 47 * These routines interface XDRSTREAMS to a tcp/ip connection. 48 * There is a record marking layer between the xdr stream 49 * and the tcp transport level. A record is composed on one or more 50 * record fragments. A record fragment is a thirty-two bit header followed 51 * by n bytes of data, where n is contained in the header. The header 52 * is represented as a htonl(u_long). Thegh order bit encodes 53 * whether or not the fragment is the last fragment of the record 54 * (1 => fragment is last, 0 => more fragments to follow. 55 * The other 31 bits encode the byte length of the fragment. 56 */ 57 58#include "namespace.h" 59#include <sys/types.h> 60 61#include <netinet/in.h> 62 63#include <err.h> 64#include <stdio.h> 65#include <stdlib.h> 66#include <string.h> 67 68#include <rpc/types.h> 69#include <rpc/xdr.h> 70#include <rpc/auth.h> 71#include <rpc/svc.h> 72#include <rpc/clnt.h> 73#include <sys/stddef.h> 74#include "un-namespace.h" 75#include "rpc_com.h" 76 77static bool_t xdrrec_getlong(XDR *, long *); 78static bool_t xdrrec_putlong(XDR *, const long *); 79static bool_t xdrrec_getbytes(XDR *, char *, u_int); 80 81static bool_t xdrrec_putbytes(XDR *, const char *, u_int); 82static u_int xdrrec_getpos(XDR *); 83static bool_t xdrrec_setpos(XDR *, u_int); 84static int32_t *xdrrec_inline(XDR *, u_int); 85static void xdrrec_destroy(XDR *); 86 87static const struct xdr_ops xdrrec_ops = { 88 xdrrec_getlong, 89 xdrrec_putlong, 90 xdrrec_getbytes, 91 xdrrec_putbytes, 92 xdrrec_getpos, 93 xdrrec_setpos, 94 xdrrec_inline, 95 xdrrec_destroy 96}; 97 98/* 99 * A record is composed of one or more record fragments. 100 * A record fragment is a four-byte header followed by zero to 101 * 2**32-1 bytes. The header is treated as a long unsigned and is 102 * encode/decoded to the network via htonl/ntohl. The low order 31 bits 103 * are a byte count of the fragment. The highest order bit is a boolean: 104 * 1 => this fragment is the last fragment of the record, 105 * 0 => this fragment is followed by more fragment(s). 106 * 107 * The fragment/record machinery is not general; it is constructed to 108 * meet the needs of xdr and rpc based on tcp. 109 */ 110 111#define LAST_FRAG ((u_int32_t)(1U << 31)) 112 113typedef struct rec_strm { 114 char *tcp_handle; 115 /* 116 * out-goung bits 117 */ 118 int (*writeit)(void *, void *, int); 119 char *out_base; /* output buffer (points to frag header) */ 120 char *out_finger; /* next output position */ 121 char *out_boundry; /* data cannot up to this address */ 122 u_int32_t *frag_header; /* beginning of curren fragment */ 123 bool_t frag_sent; /* true if buffer sent in middle of record */ 124 /* 125 * in-coming bits 126 */ 127 int (*readit)(void *, void *, int); 128 u_long in_size; /* fixed size of the input buffer */ 129 char *in_base; 130 char *in_finger; /* location of next byte to be had */ 131 char *in_boundry; /* can read up to this location */ 132 long fbtbc; /* fragment bytes to be consumed */ 133 bool_t last_frag; 134 u_int sendsize; 135 u_int recvsize; 136 137 bool_t nonblock; 138 bool_t in_haveheader; 139 u_int32_t in_header; 140 char *in_hdrp; 141 int in_hdrlen; 142 int in_reclen; 143 int in_received; 144 int in_maxrec; 145} RECSTREAM; 146 147static u_int fix_buf_size(u_int); 148static bool_t flush_out(RECSTREAM *, bool_t); 149static bool_t fill_input_buf(RECSTREAM *); 150static bool_t get_input_bytes(RECSTREAM *, char *, int); 151static bool_t set_input_fragment(RECSTREAM *); 152static bool_t skip_input_bytes(RECSTREAM *, long); 153static bool_t realloc_stream(RECSTREAM *, int); 154 155 156/* 157 * Create an xdr handle for xdrrec 158 * xdrrec_create fills in xdrs. Sendsize and recvsize are 159 * send and recv buffer sizes (0 => use default). 160 * tcp_handle is an opaque handle that is passed as the first parameter to 161 * the procedures readit and writeit. Readit and writeit are read and 162 * write respectively. They are like the system 163 * calls expect that they take an opaque handle rather than an fd. 164 */ 165void 166xdrrec_create(XDR *xdrs, u_int sendsize, u_int recvsize, void *tcp_handle, 167 int (*readit)(void *, void *, int), int (*writeit)(void *, void *, int)) 168/* 169 * XDR *xdrs; 170 * u_int sendsize; 171 * u_int recvsize; 172 * void *tcp_handle; 173 * // like read, but pass it a tcp_handle, not sock 174 * int (*readit)(void *, void *, int); 175 * // like write, but pass it a tcp_handle, not sock 176 * int (*writeit)(void *, void *, int); 177 */ 178{ 179 RECSTREAM *rstrm = mem_alloc(sizeof(RECSTREAM)); 180 181 if (rstrm == NULL) { 182 warnx("xdrrec_create: out of memory"); 183 /* 184 * This is bad. Should rework xdrrec_create to 185 * return a handle, and in this case return NULL 186 */ 187 return; 188 } 189 rstrm->sendsize = sendsize = fix_buf_size(sendsize); 190 rstrm->out_base = mem_alloc(rstrm->sendsize); 191 if (rstrm->out_base == NULL) { 192 warnx("xdrrec_create: out of memory"); 193 mem_free(rstrm, sizeof(RECSTREAM)); 194 return; 195 } 196 rstrm->recvsize = recvsize = fix_buf_size(recvsize); 197 rstrm->in_base = mem_alloc(recvsize); 198 if (rstrm->in_base == NULL) { 199 warnx("xdrrec_create: out of memory"); 200 mem_free(rstrm->out_base, sendsize); 201 mem_free(rstrm, sizeof(RECSTREAM)); 202 return; 203 } 204 /* 205 * now the rest ... 206 */ 207 xdrs->x_ops = &xdrrec_ops; 208 xdrs->x_private = rstrm; 209 rstrm->tcp_handle = tcp_handle; 210 rstrm->readit = readit; 211 rstrm->writeit = writeit; 212 rstrm->out_finger = rstrm->out_boundry = rstrm->out_base; 213 rstrm->frag_header = (u_int32_t *)(void *)rstrm->out_base; 214 rstrm->out_finger += sizeof(u_int32_t); 215 rstrm->out_boundry += sendsize; 216 rstrm->frag_sent = FALSE; 217 rstrm->in_size = recvsize; 218 rstrm->in_boundry = rstrm->in_base; 219 rstrm->in_finger = (rstrm->in_boundry += recvsize); 220 rstrm->fbtbc = 0; 221 rstrm->last_frag = TRUE; 222 rstrm->in_haveheader = FALSE; 223 rstrm->in_hdrlen = 0; 224 rstrm->in_hdrp = (char *)(void *)&rstrm->in_header; 225 rstrm->nonblock = FALSE; 226 rstrm->in_reclen = 0; 227 rstrm->in_received = 0; 228} 229 230 231/* 232 * The reoutines defined below are the xdr ops which will go into the 233 * xdr handle filled in by xdrrec_create. 234 */ 235 236static bool_t 237xdrrec_getlong(XDR *xdrs, long *lp) 238{ 239 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 240 int32_t *buflp = (int32_t *)(void *)(rstrm->in_finger); 241 int32_t mylong; 242 243 /* first try the inline, fast case */ 244 if ((rstrm->fbtbc >= sizeof(int32_t)) && 245 (((long)rstrm->in_boundry - (long)buflp) >= sizeof(int32_t))) { 246 *lp = (long)ntohl((u_int32_t)(*buflp)); 247 rstrm->fbtbc -= sizeof(int32_t); 248 rstrm->in_finger += sizeof(int32_t); 249 } else { 250 if (! xdrrec_getbytes(xdrs, (char *)(void *)&mylong, 251 sizeof(int32_t))) 252 return (FALSE); 253 *lp = (long)ntohl((u_int32_t)mylong); 254 } 255 return (TRUE); 256} 257 258static bool_t 259xdrrec_putlong(XDR *xdrs, const long *lp) 260{ 261 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 262 int32_t *dest_lp = ((int32_t *)(void *)(rstrm->out_finger)); 263 264 if ((rstrm->out_finger += sizeof(int32_t)) > rstrm->out_boundry) { 265 /* 266 * this case should almost never happen so the code is 267 * inefficient 268 */ 269 rstrm->out_finger -= sizeof(int32_t); 270 rstrm->frag_sent = TRUE; 271 if (! flush_out(rstrm, FALSE)) 272 return (FALSE); 273 dest_lp = ((int32_t *)(void *)(rstrm->out_finger)); 274 rstrm->out_finger += sizeof(int32_t); 275 } 276 *dest_lp = (int32_t)htonl((u_int32_t)(*lp)); 277 return (TRUE); 278} 279 280static bool_t /* must manage buffers, fragments, and records */ 281xdrrec_getbytes(XDR *xdrs, char *addr, u_int len) 282{ 283 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 284 int current; 285 286 while (len > 0) { 287 current = (int)rstrm->fbtbc; 288 if (current == 0) { 289 if (rstrm->last_frag) 290 return (FALSE); 291 if (! set_input_fragment(rstrm)) 292 return (FALSE); 293 continue; 294 } 295 current = (len < current) ? len : current; 296 if (! get_input_bytes(rstrm, addr, current)) 297 return (FALSE); 298 addr += current; 299 rstrm->fbtbc -= current; 300 len -= current; 301 } 302 return (TRUE); 303} 304 305static bool_t 306xdrrec_putbytes(XDR *xdrs, const char *addr, u_int len) 307{ 308 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 309 size_t current; 310 311 while (len > 0) { 312 current = (size_t)((u_long)rstrm->out_boundry - 313 (u_long)rstrm->out_finger); 314 current = (len < current) ? len : current; 315 memmove(rstrm->out_finger, addr, current); 316 rstrm->out_finger += current; 317 addr += current; 318 len -= current; 319 if (rstrm->out_finger == rstrm->out_boundry) { 320 rstrm->frag_sent = TRUE; 321 if (! flush_out(rstrm, FALSE)) 322 return (FALSE); 323 } 324 } 325 return (TRUE); 326} 327 328static u_int 329xdrrec_getpos(XDR *xdrs) 330{ 331 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; 332 off_t pos; 333 334 pos = lseek((int)(u_long)rstrm->tcp_handle, (off_t)0, 1); 335 if (pos == -1) 336 pos = 0; 337 switch (xdrs->x_op) { 338 339 case XDR_ENCODE: 340 pos += rstrm->out_finger - rstrm->out_base; 341 break; 342 343 case XDR_DECODE: 344 pos -= rstrm->in_boundry - rstrm->in_finger; 345 break; 346 347 default: 348 pos = (off_t) -1; 349 break; 350 } 351 return ((u_int) pos); 352} 353 354static bool_t 355xdrrec_setpos(XDR *xdrs, u_int pos) 356{ 357 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; 358 u_int currpos = xdrrec_getpos(xdrs); 359 int delta = currpos - pos; 360 char *newpos; 361 362 if ((int)currpos != -1) 363 switch (xdrs->x_op) { 364 365 case XDR_ENCODE: 366 newpos = rstrm->out_finger - delta; 367 if ((newpos > (char *)(void *)(rstrm->frag_header)) && 368 (newpos < rstrm->out_boundry)) { 369 rstrm->out_finger = newpos; 370 return (TRUE); 371 } 372 break; 373 374 case XDR_DECODE: 375 newpos = rstrm->in_finger - delta; 376 if ((delta < (int)(rstrm->fbtbc)) && 377 (newpos <= rstrm->in_boundry) && 378 (newpos >= rstrm->in_base)) { 379 rstrm->in_finger = newpos; 380 rstrm->fbtbc -= delta; 381 return (TRUE); 382 } 383 break; 384 385 case XDR_FREE: 386 break; 387 } 388 return (FALSE); 389} 390 391static int32_t * 392xdrrec_inline(XDR *xdrs, u_int len) 393{ 394 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; 395 int32_t *buf = NULL; 396 397 switch (xdrs->x_op) { 398 399 case XDR_ENCODE: 400 if ((rstrm->out_finger + len) <= rstrm->out_boundry) { 401 buf = (int32_t *)(void *)rstrm->out_finger; 402 rstrm->out_finger += len; 403 } 404 break; 405 406 case XDR_DECODE: 407 if ((len <= rstrm->fbtbc) && 408 ((rstrm->in_finger + len) <= rstrm->in_boundry)) { 409 buf = (int32_t *)(void *)rstrm->in_finger; 410 rstrm->fbtbc -= len; 411 rstrm->in_finger += len; 412 } 413 break; 414 415 case XDR_FREE: 416 break; 417 } 418 return (buf); 419} 420 421static void 422xdrrec_destroy(XDR *xdrs) 423{ 424 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; 425 426 mem_free(rstrm->out_base, rstrm->sendsize); 427 mem_free(rstrm->in_base, rstrm->recvsize); 428 mem_free(rstrm, sizeof(RECSTREAM)); 429} 430 431 432/* 433 * Exported routines to manage xdr records 434 */ 435 436/* 437 * Before reading (deserializing from the stream, one should always call 438 * this procedure to guarantee proper record alignment. 439 */ 440bool_t 441xdrrec_skiprecord(XDR *xdrs) 442{ 443 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 444 enum xprt_stat xstat; 445 446 if (rstrm->nonblock) { 447 if (__xdrrec_getrec(xdrs, &xstat, FALSE)) { 448 rstrm->fbtbc = 0; 449 return TRUE; 450 } 451 if (rstrm->in_finger == rstrm->in_boundry && 452 xstat == XPRT_MOREREQS) { 453 rstrm->fbtbc = 0; 454 return TRUE; 455 } 456 return FALSE; 457 } 458 459 while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) { 460 if (! skip_input_bytes(rstrm, rstrm->fbtbc)) 461 return (FALSE); 462 rstrm->fbtbc = 0; 463 if ((! rstrm->last_frag) && (! set_input_fragment(rstrm))) 464 return (FALSE); 465 } 466 rstrm->last_frag = FALSE; 467 return (TRUE); 468} 469 470/* 471 * Look ahead function. 472 * Returns TRUE iff there is no more input in the buffer 473 * after consuming the rest of the current record. 474 */ 475bool_t 476xdrrec_eof(XDR *xdrs) 477{ 478 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 479 480 while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) { 481 if (! skip_input_bytes(rstrm, rstrm->fbtbc)) 482 return (TRUE); 483 rstrm->fbtbc = 0; 484 if ((! rstrm->last_frag) && (! set_input_fragment(rstrm))) 485 return (TRUE); 486 } 487 if (rstrm->in_finger == rstrm->in_boundry) 488 return (TRUE); 489 return (FALSE); 490} 491 492/* 493 * The client must tell the package when an end-of-record has occurred. 494 * The second paraemters tells whether the record should be flushed to the 495 * (output) tcp stream. (This let's the package support batched or 496 * pipelined procedure calls.) TRUE => immmediate flush to tcp connection. 497 */ 498bool_t 499xdrrec_endofrecord(XDR *xdrs, bool_t sendnow) 500{ 501 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 502 u_long len; /* fragment length */ 503 504 if (sendnow || rstrm->frag_sent || 505 ((u_long)rstrm->out_finger + sizeof(u_int32_t) >= 506 (u_long)rstrm->out_boundry)) { 507 rstrm->frag_sent = FALSE; 508 return (flush_out(rstrm, TRUE)); 509 } 510 len = (u_long)(rstrm->out_finger) - (u_long)(rstrm->frag_header) - 511 sizeof(u_int32_t); 512 *(rstrm->frag_header) = htonl((u_int32_t)len | LAST_FRAG); 513 rstrm->frag_header = (u_int32_t *)(void *)rstrm->out_finger; 514 rstrm->out_finger += sizeof(u_int32_t); 515 return (TRUE); 516} 517 518/* 519 * Fill the stream buffer with a record for a non-blocking connection. 520 * Return true if a record is available in the buffer, false if not. 521 */ 522bool_t 523__xdrrec_getrec(XDR *xdrs, enum xprt_stat *statp, bool_t expectdata) 524{ 525 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 526 ssize_t n; 527 int fraglen; 528 529 if (!rstrm->in_haveheader) { 530 n = rstrm->readit(rstrm->tcp_handle, rstrm->in_hdrp, 531 (int)sizeof (rstrm->in_header) - rstrm->in_hdrlen); 532 if (n == 0) { 533 *statp = expectdata ? XPRT_DIED : XPRT_IDLE; 534 return FALSE; 535 } 536 if (n < 0) { 537 *statp = XPRT_DIED; 538 return FALSE; 539 } 540 rstrm->in_hdrp += n; 541 rstrm->in_hdrlen += n; 542 if (rstrm->in_hdrlen < sizeof (rstrm->in_header)) { 543 *statp = XPRT_MOREREQS; 544 return FALSE; 545 } 546 rstrm->in_header = ntohl(rstrm->in_header); 547 fraglen = (int)(rstrm->in_header & ~LAST_FRAG); 548 if (fraglen == 0 || fraglen > rstrm->in_maxrec || 549 (rstrm->in_reclen + fraglen) > rstrm->in_maxrec) { 550 *statp = XPRT_DIED; 551 return FALSE; 552 } 553 rstrm->in_reclen += fraglen; 554 if (rstrm->in_reclen > rstrm->recvsize) 555 realloc_stream(rstrm, rstrm->in_reclen); 556 if (rstrm->in_header & LAST_FRAG) { 557 rstrm->in_header &= ~LAST_FRAG; 558 rstrm->last_frag = TRUE; 559 } 560 /* 561 * We can only reasonably expect to read once from a 562 * non-blocking stream. Reading the fragment header 563 * may have drained the stream. 564 */ 565 expectdata = FALSE; 566 } 567 568 n = rstrm->readit(rstrm->tcp_handle, 569 rstrm->in_base + rstrm->in_received, 570 (rstrm->in_reclen - rstrm->in_received)); 571 572 if (n < 0) { 573 *statp = XPRT_DIED; 574 return FALSE; 575 } 576 577 if (n == 0) { 578 *statp = expectdata ? XPRT_DIED : XPRT_IDLE; 579 return FALSE; 580 } 581 582 rstrm->in_received += n; 583 584 if (rstrm->in_received == rstrm->in_reclen) { 585 rstrm->in_haveheader = FALSE; 586 rstrm->in_hdrp = (char *)(void *)&rstrm->in_header; 587 rstrm->in_hdrlen = 0; 588 if (rstrm->last_frag) { 589 rstrm->fbtbc = rstrm->in_reclen; 590 rstrm->in_boundry = rstrm->in_base + rstrm->in_reclen; 591 rstrm->in_finger = rstrm->in_base; 592 rstrm->in_reclen = rstrm->in_received = 0; 593 *statp = XPRT_MOREREQS; 594 return TRUE; 595 } 596 } 597 598 *statp = XPRT_MOREREQS; 599 return FALSE; 600} 601 602bool_t 603__xdrrec_setnonblock(XDR *xdrs, int maxrec) 604{ 605 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 606 607 rstrm->nonblock = TRUE; 608 if (maxrec == 0) 609 maxrec = rstrm->recvsize; 610 rstrm->in_maxrec = maxrec; 611 return TRUE; 612} 613 614/* 615 * Internal useful routines 616 */ 617static bool_t 618flush_out(RECSTREAM *rstrm, bool_t eor) 619{ 620 u_int32_t eormask = (eor == TRUE) ? LAST_FRAG : 0; 621 u_int32_t len = (u_int32_t)((u_long)(rstrm->out_finger) - 622 (u_long)(rstrm->frag_header) - sizeof(u_int32_t)); 623 624 *(rstrm->frag_header) = htonl(len | eormask); 625 len = (u_int32_t)((u_long)(rstrm->out_finger) - 626 (u_long)(rstrm->out_base)); 627 if ((*(rstrm->writeit))(rstrm->tcp_handle, rstrm->out_base, (int)len) 628 != (int)len) 629 return (FALSE); 630 rstrm->frag_header = (u_int32_t *)(void *)rstrm->out_base; 631 rstrm->out_finger = (char *)rstrm->out_base + sizeof(u_int32_t); 632 return (TRUE); 633} 634 635static bool_t /* knows nothing about records! Only about input buffers */ 636fill_input_buf(RECSTREAM *rstrm) 637{ 638 char *where; 639 u_int32_t i; 640 int len; 641 642 if (rstrm->nonblock) 643 return FALSE; 644 645 where = rstrm->in_base; 646 i = (u_int32_t)((u_long)rstrm->in_boundry % BYTES_PER_XDR_UNIT); 647 where += i; 648 len = (u_int32_t)(rstrm->in_size - i); 649 if ((len = (*(rstrm->readit))(rstrm->tcp_handle, where, len)) == -1) 650 return (FALSE); 651 rstrm->in_finger = where; 652 where += len; 653 rstrm->in_boundry = where; 654 return (TRUE); 655} 656 657static bool_t /* knows nothing about records! Only about input buffers */ 658get_input_bytes(RECSTREAM *rstrm, char *addr, int len) 659{ 660 size_t current; 661 662 if (rstrm->nonblock) { 663 if (len > (int)(rstrm->in_boundry - rstrm->in_finger)) 664 return FALSE; 665 memcpy(addr, rstrm->in_finger, (size_t)len); 666 rstrm->in_finger += len; 667 return TRUE; 668 } 669 670 while (len > 0) { 671 current = (size_t)((long)rstrm->in_boundry - 672 (long)rstrm->in_finger); 673 if (current == 0) { 674 if (! fill_input_buf(rstrm)) 675 return (FALSE); 676 continue; 677 } 678 current = (len < current) ? len : current; 679 memmove(addr, rstrm->in_finger, current); 680 rstrm->in_finger += current; 681 addr += current; 682 len -= current; 683 } 684 return (TRUE); 685} 686 687static bool_t /* next two bytes of the input stream are treated as a header */ 688set_input_fragment(RECSTREAM *rstrm) 689{ 690 u_int32_t header; 691 692 if (rstrm->nonblock) 693 return FALSE; 694 if (! get_input_bytes(rstrm, (char *)(void *)&header, sizeof(header))) 695 return (FALSE); 696 header = ntohl(header); 697 rstrm->last_frag = ((header & LAST_FRAG) == 0) ? FALSE : TRUE; 698 /* 699 * Sanity check. Try not to accept wildly incorrect 700 * record sizes. Unfortunately, the only record size 701 * we can positively identify as being 'wildly incorrect' 702 * is zero. Ridiculously large record sizes may look wrong, 703 * but we don't have any way to be certain that they aren't 704 * what the client actually intended to send us. 705 */ 706 if (header == 0) 707 return(FALSE); 708 rstrm->fbtbc = header & (~LAST_FRAG); 709 return (TRUE); 710} 711 712static bool_t /* consumes input bytes; knows nothing about records! */ 713skip_input_bytes(RECSTREAM *rstrm, long cnt) 714{ 715 u_int32_t current; 716 717 while (cnt > 0) { 718 current = (size_t)((long)rstrm->in_boundry - 719 (long)rstrm->in_finger); 720 if (current == 0) { 721 if (! fill_input_buf(rstrm)) 722 return (FALSE); 723 continue; 724 } 725 current = (u_int32_t)((cnt < current) ? cnt : current); 726 rstrm->in_finger += current; 727 cnt -= current; 728 } 729 return (TRUE); 730} 731 732static u_int 733fix_buf_size(u_int s) 734{ 735 736 if (s < 100) 737 s = 4000; 738 return (RNDUP(s)); 739} 740 741/* 742 * Reallocate the input buffer for a non-block stream. 743 */ 744static bool_t 745realloc_stream(RECSTREAM *rstrm, int size) 746{ 747 ptrdiff_t diff; 748 char *buf; 749 750 if (size > rstrm->recvsize) { 751 buf = realloc(rstrm->in_base, (size_t)size); 752 if (buf == NULL) 753 return FALSE; 754 diff = buf - rstrm->in_base; 755 rstrm->in_finger += diff; 756 rstrm->in_base = buf; 757 rstrm->in_boundry = buf + size; 758 rstrm->recvsize = size; 759 rstrm->in_size = size; 760 } 761 762 return TRUE; 763} 764