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 70static bool_t xdrrec_getlong(XDR *, long *); 71static bool_t xdrrec_putlong(XDR *, const long *); 72static bool_t xdrrec_getbytes(XDR *, char *, u_int); 73 74static bool_t xdrrec_putbytes(XDR *, const char *, u_int); 75static u_int xdrrec_getpos(XDR *); 76static bool_t xdrrec_setpos(XDR *, u_int); 77static int32_t *xdrrec_inline(XDR *, u_int); 78static void xdrrec_destroy(XDR *); 79 80static 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 106typedef 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 140static u_int fix_buf_size(u_int); 141static bool_t flush_out(RECSTREAM *, bool_t); 142static bool_t fill_input_buf(RECSTREAM *); 143static bool_t get_input_bytes(RECSTREAM *, char *, int); 144static bool_t set_input_fragment(RECSTREAM *); 145static bool_t skip_input_bytes(RECSTREAM *, long); 146static 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 */ 158void 159xdrrec_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 229static bool_t 230xdrrec_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 251static bool_t 252xdrrec_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 273static bool_t /* must manage buffers, fragments, and records */ 274xdrrec_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 298static bool_t 299xdrrec_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 321static u_int 322xdrrec_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 347static bool_t 348xdrrec_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 384static int32_t * 385xdrrec_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 414static void 415xdrrec_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 */ 433bool_t 434xdrrec_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 */ 468bool_t 469xdrrec_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 */ 491bool_t 492xdrrec_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 */ 515bool_t 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 595bool_t 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 */ 610static bool_t 611flush_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 628static bool_t /* knows nothing about records! Only about input buffers */ 629fill_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 650static bool_t /* knows nothing about records! Only about input buffers */ 651get_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 680static bool_t /* next two bytes of the input stream are treated as a header */ 681set_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 705static bool_t /* consumes input bytes; knows nothing about records! */ 706skip_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 725static u_int 726fix_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 */ 737static bool_t 738realloc_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