1 /* $NetBSD: xdr_rec.c,v 1.18 2000/07/06 03:10:35 christos Exp $ */ 2 3 /* 4 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for 5 * unrestricted use provided that this legend is included on all tape 6 * media and as a part of the software program in whole or part. Users 7 * may copy or modify Sun RPC without charge, but are not authorized 8 * to license or distribute it to anyone else except as part of a product or 9 * program developed by the user. 10 * 11 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE 12 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR 13 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE. 14 * 15 * Sun RPC is provided with no support and without any obligation on the 16 * part of Sun Microsystems, Inc. to assist in its use, correction, 17 * modification or enhancement. 18 * 19 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE 20 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC 21 * OR ANY PART THEREOF. 22 * 23 * In no event will Sun Microsystems, Inc. be liable for any lost revenue 24 * or profits or other special, indirect and consequential damages, even if 25 * Sun has been advised of the possibility of such damages. 26 * 27 * Sun Microsystems, Inc. 28 * 2550 Garcia Avenue 29 * Mountain View, California 94043 30 */ 31 32 #if defined(LIBC_SCCS) && !defined(lint) 33 static char *sccsid2 = "@(#)xdr_rec.c 1.21 87/08/11 Copyr 1984 Sun Micro"; 34 static char *sccsid = "@(#)xdr_rec.c 2.2 88/08/01 4.0 RPCSRC"; 35 #endif 36 #include <sys/cdefs.h> 37 __FBSDID("$FreeBSD$"); 38 39 /* 40 * xdr_rec.c, Implements TCP/IP based XDR streams with a "record marking" 41 * layer above tcp (for rpc's use). 42 * 43 * Copyright (C) 1984, Sun Microsystems, Inc. 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)(1 << 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 164 xdrrec_create(xdrs, sendsize, recvsize, tcp_handle, readit, writeit) 165 XDR *xdrs; 166 u_int sendsize; 167 u_int recvsize; 168 void *tcp_handle; 169 /* like read, but pass it a tcp_handle, not sock */ 170 int (*readit)(void *, void *, int); 171 /* like write, but pass it a tcp_handle, not sock */ 172 int (*writeit)(void *, void *, int); 173 { 174 RECSTREAM *rstrm = mem_alloc(sizeof(RECSTREAM)); 175 176 if (rstrm == NULL) { 177 warnx("xdrrec_create: out of memory"); 178 /* 179 * This is bad. Should rework xdrrec_create to 180 * return a handle, and in this case return NULL 181 */ 182 return; 183 } 184 rstrm->sendsize = sendsize = fix_buf_size(sendsize); 185 rstrm->out_base = mem_alloc(rstrm->sendsize); 186 if (rstrm->out_base == NULL) { 187 warnx("xdrrec_create: out of memory"); 188 mem_free(rstrm, sizeof(RECSTREAM)); 189 return; 190 } 191 rstrm->recvsize = recvsize = fix_buf_size(recvsize); 192 rstrm->in_base = mem_alloc(recvsize); 193 if (rstrm->in_base == NULL) { 194 warnx("xdrrec_create: out of memory"); 195 mem_free(rstrm->out_base, sendsize); 196 mem_free(rstrm, sizeof(RECSTREAM)); 197 return; 198 } 199 /* 200 * now the rest ... 201 */ 202 xdrs->x_ops = &xdrrec_ops; 203 xdrs->x_private = rstrm; 204 rstrm->tcp_handle = tcp_handle; 205 rstrm->readit = readit; 206 rstrm->writeit = writeit; 207 rstrm->out_finger = rstrm->out_boundry = rstrm->out_base; 208 rstrm->frag_header = (u_int32_t *)(void *)rstrm->out_base; 209 rstrm->out_finger += sizeof(u_int32_t); 210 rstrm->out_boundry += sendsize; 211 rstrm->frag_sent = FALSE; 212 rstrm->in_size = recvsize; 213 rstrm->in_boundry = rstrm->in_base; 214 rstrm->in_finger = (rstrm->in_boundry += recvsize); 215 rstrm->fbtbc = 0; 216 rstrm->last_frag = TRUE; 217 rstrm->in_haveheader = FALSE; 218 rstrm->in_hdrlen = 0; 219 rstrm->in_hdrp = (char *)(void *)&rstrm->in_header; 220 rstrm->nonblock = FALSE; 221 rstrm->in_reclen = 0; 222 rstrm->in_received = 0; 223 } 224 225 226 /* 227 * The reoutines defined below are the xdr ops which will go into the 228 * xdr handle filled in by xdrrec_create. 229 */ 230 231 static bool_t 232 xdrrec_getlong(xdrs, lp) 233 XDR *xdrs; 234 long *lp; 235 { 236 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 237 int32_t *buflp = (int32_t *)(void *)(rstrm->in_finger); 238 int32_t mylong; 239 240 /* first try the inline, fast case */ 241 if ((rstrm->fbtbc >= sizeof(int32_t)) && 242 (((long)rstrm->in_boundry - (long)buflp) >= sizeof(int32_t))) { 243 *lp = (long)ntohl((u_int32_t)(*buflp)); 244 rstrm->fbtbc -= sizeof(int32_t); 245 rstrm->in_finger += sizeof(int32_t); 246 } else { 247 if (! xdrrec_getbytes(xdrs, (char *)(void *)&mylong, 248 sizeof(int32_t))) 249 return (FALSE); 250 *lp = (long)ntohl((u_int32_t)mylong); 251 } 252 return (TRUE); 253 } 254 255 static bool_t 256 xdrrec_putlong(xdrs, lp) 257 XDR *xdrs; 258 const long *lp; 259 { 260 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 261 int32_t *dest_lp = ((int32_t *)(void *)(rstrm->out_finger)); 262 263 if ((rstrm->out_finger += sizeof(int32_t)) > rstrm->out_boundry) { 264 /* 265 * this case should almost never happen so the code is 266 * inefficient 267 */ 268 rstrm->out_finger -= sizeof(int32_t); 269 rstrm->frag_sent = TRUE; 270 if (! flush_out(rstrm, FALSE)) 271 return (FALSE); 272 dest_lp = ((int32_t *)(void *)(rstrm->out_finger)); 273 rstrm->out_finger += sizeof(int32_t); 274 } 275 *dest_lp = (int32_t)htonl((u_int32_t)(*lp)); 276 return (TRUE); 277 } 278 279 static bool_t /* must manage buffers, fragments, and records */ 280 xdrrec_getbytes(xdrs, addr, len) 281 XDR *xdrs; 282 char *addr; 283 u_int len; 284 { 285 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 286 int current; 287 288 while (len > 0) { 289 current = (int)rstrm->fbtbc; 290 if (current == 0) { 291 if (rstrm->last_frag) 292 return (FALSE); 293 if (! set_input_fragment(rstrm)) 294 return (FALSE); 295 continue; 296 } 297 current = (len < current) ? len : current; 298 if (! get_input_bytes(rstrm, addr, current)) 299 return (FALSE); 300 addr += current; 301 rstrm->fbtbc -= current; 302 len -= current; 303 } 304 return (TRUE); 305 } 306 307 static bool_t 308 xdrrec_putbytes(xdrs, addr, len) 309 XDR *xdrs; 310 const char *addr; 311 u_int len; 312 { 313 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 314 size_t current; 315 316 while (len > 0) { 317 current = (size_t)((u_long)rstrm->out_boundry - 318 (u_long)rstrm->out_finger); 319 current = (len < current) ? len : current; 320 memmove(rstrm->out_finger, addr, current); 321 rstrm->out_finger += current; 322 addr += current; 323 len -= current; 324 if (rstrm->out_finger == rstrm->out_boundry) { 325 rstrm->frag_sent = TRUE; 326 if (! flush_out(rstrm, FALSE)) 327 return (FALSE); 328 } 329 } 330 return (TRUE); 331 } 332 333 static u_int 334 xdrrec_getpos(xdrs) 335 XDR *xdrs; 336 { 337 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; 338 off_t pos; 339 340 pos = lseek((int)(u_long)rstrm->tcp_handle, (off_t)0, 1); 341 if (pos == -1) 342 pos = 0; 343 switch (xdrs->x_op) { 344 345 case XDR_ENCODE: 346 pos += rstrm->out_finger - rstrm->out_base; 347 break; 348 349 case XDR_DECODE: 350 pos -= rstrm->in_boundry - rstrm->in_finger; 351 break; 352 353 default: 354 pos = (off_t) -1; 355 break; 356 } 357 return ((u_int) pos); 358 } 359 360 static bool_t 361 xdrrec_setpos(xdrs, pos) 362 XDR *xdrs; 363 u_int pos; 364 { 365 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; 366 u_int currpos = xdrrec_getpos(xdrs); 367 int delta = currpos - pos; 368 char *newpos; 369 370 if ((int)currpos != -1) 371 switch (xdrs->x_op) { 372 373 case XDR_ENCODE: 374 newpos = rstrm->out_finger - delta; 375 if ((newpos > (char *)(void *)(rstrm->frag_header)) && 376 (newpos < rstrm->out_boundry)) { 377 rstrm->out_finger = newpos; 378 return (TRUE); 379 } 380 break; 381 382 case XDR_DECODE: 383 newpos = rstrm->in_finger - delta; 384 if ((delta < (int)(rstrm->fbtbc)) && 385 (newpos <= rstrm->in_boundry) && 386 (newpos >= rstrm->in_base)) { 387 rstrm->in_finger = newpos; 388 rstrm->fbtbc -= delta; 389 return (TRUE); 390 } 391 break; 392 393 case XDR_FREE: 394 break; 395 } 396 return (FALSE); 397 } 398 399 static int32_t * 400 xdrrec_inline(xdrs, len) 401 XDR *xdrs; 402 u_int len; 403 { 404 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; 405 int32_t *buf = NULL; 406 407 switch (xdrs->x_op) { 408 409 case XDR_ENCODE: 410 if ((rstrm->out_finger + len) <= rstrm->out_boundry) { 411 buf = (int32_t *)(void *)rstrm->out_finger; 412 rstrm->out_finger += len; 413 } 414 break; 415 416 case XDR_DECODE: 417 if ((len <= rstrm->fbtbc) && 418 ((rstrm->in_finger + len) <= rstrm->in_boundry)) { 419 buf = (int32_t *)(void *)rstrm->in_finger; 420 rstrm->fbtbc -= len; 421 rstrm->in_finger += len; 422 } 423 break; 424 425 case XDR_FREE: 426 break; 427 } 428 return (buf); 429 } 430 431 static void 432 xdrrec_destroy(xdrs) 433 XDR *xdrs; 434 { 435 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; 436 437 mem_free(rstrm->out_base, rstrm->sendsize); 438 mem_free(rstrm->in_base, rstrm->recvsize); 439 mem_free(rstrm, sizeof(RECSTREAM)); 440 } 441 442 443 /* 444 * Exported routines to manage xdr records 445 */ 446 447 /* 448 * Before reading (deserializing from the stream, one should always call 449 * this procedure to guarantee proper record alignment. 450 */ 451 bool_t 452 xdrrec_skiprecord(xdrs) 453 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 } 470 471 while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) { 472 if (! skip_input_bytes(rstrm, rstrm->fbtbc)) 473 return (FALSE); 474 rstrm->fbtbc = 0; 475 if ((! rstrm->last_frag) && (! set_input_fragment(rstrm))) 476 return (FALSE); 477 } 478 rstrm->last_frag = FALSE; 479 return (TRUE); 480 } 481 482 /* 483 * Look ahead function. 484 * Returns TRUE iff there is no more input in the buffer 485 * after consuming the rest of the current record. 486 */ 487 bool_t 488 xdrrec_eof(xdrs) 489 XDR *xdrs; 490 { 491 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 492 493 while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) { 494 if (! skip_input_bytes(rstrm, rstrm->fbtbc)) 495 return (TRUE); 496 rstrm->fbtbc = 0; 497 if ((! rstrm->last_frag) && (! set_input_fragment(rstrm))) 498 return (TRUE); 499 } 500 if (rstrm->in_finger == rstrm->in_boundry) 501 return (TRUE); 502 return (FALSE); 503 } 504 505 /* 506 * The client must tell the package when an end-of-record has occurred. 507 * The second paraemters tells whether the record should be flushed to the 508 * (output) tcp stream. (This let's the package support batched or 509 * pipelined procedure calls.) TRUE => immmediate flush to tcp connection. 510 */ 511 bool_t 512 xdrrec_endofrecord(xdrs, sendnow) 513 XDR *xdrs; 514 bool_t sendnow; 515 { 516 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 517 u_long len; /* fragment length */ 518 519 if (sendnow || rstrm->frag_sent || 520 ((u_long)rstrm->out_finger + sizeof(u_int32_t) >= 521 (u_long)rstrm->out_boundry)) { 522 rstrm->frag_sent = FALSE; 523 return (flush_out(rstrm, TRUE)); 524 } 525 len = (u_long)(rstrm->out_finger) - (u_long)(rstrm->frag_header) - 526 sizeof(u_int32_t); 527 *(rstrm->frag_header) = htonl((u_int32_t)len | LAST_FRAG); 528 rstrm->frag_header = (u_int32_t *)(void *)rstrm->out_finger; 529 rstrm->out_finger += sizeof(u_int32_t); 530 return (TRUE); 531 } 532 533 /* 534 * Fill the stream buffer with a record for a non-blocking connection. 535 * Return true if a record is available in the buffer, false if not. 536 */ 537 bool_t 538 __xdrrec_getrec(xdrs, statp, expectdata) 539 XDR *xdrs; 540 enum xprt_stat *statp; 541 bool_t expectdata; 542 { 543 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 544 ssize_t n; 545 int fraglen; 546 547 if (!rstrm->in_haveheader) { 548 n = rstrm->readit(rstrm->tcp_handle, rstrm->in_hdrp, 549 (int)sizeof (rstrm->in_header) - rstrm->in_hdrlen); 550 if (n == 0) { 551 *statp = expectdata ? XPRT_DIED : XPRT_IDLE; 552 return FALSE; 553 } 554 if (n < 0) { 555 *statp = XPRT_DIED; 556 return FALSE; 557 } 558 rstrm->in_hdrp += n; 559 rstrm->in_hdrlen += n; 560 if (rstrm->in_hdrlen < sizeof (rstrm->in_header)) { 561 *statp = XPRT_MOREREQS; 562 return FALSE; 563 } 564 rstrm->in_header = ntohl(rstrm->in_header); 565 fraglen = (int)(rstrm->in_header & ~LAST_FRAG); 566 if (fraglen == 0 || fraglen > rstrm->in_maxrec || 567 (rstrm->in_reclen + fraglen) > rstrm->in_maxrec) { 568 *statp = XPRT_DIED; 569 return FALSE; 570 } 571 rstrm->in_reclen += fraglen; 572 if (rstrm->in_reclen > rstrm->recvsize) 573 realloc_stream(rstrm, rstrm->in_reclen); 574 if (rstrm->in_header & LAST_FRAG) { 575 rstrm->in_header &= ~LAST_FRAG; 576 rstrm->last_frag = TRUE; 577 } 578 /* 579 * We can only reasonably expect to read once from a 580 * non-blocking stream. Reading the fragment header 581 * may have drained the stream. 582 */ 583 expectdata = FALSE; 584 } 585 586 n = rstrm->readit(rstrm->tcp_handle, 587 rstrm->in_base + rstrm->in_received, 588 (rstrm->in_reclen - rstrm->in_received)); 589 590 if (n < 0) { 591 *statp = XPRT_DIED; 592 return FALSE; 593 } 594 595 if (n == 0) { 596 *statp = expectdata ? XPRT_DIED : XPRT_IDLE; 597 return FALSE; 598 } 599 600 rstrm->in_received += n; 601 602 if (rstrm->in_received == rstrm->in_reclen) { 603 rstrm->in_haveheader = FALSE; 604 rstrm->in_hdrp = (char *)(void *)&rstrm->in_header; 605 rstrm->in_hdrlen = 0; 606 if (rstrm->last_frag) { 607 rstrm->fbtbc = rstrm->in_reclen; 608 rstrm->in_boundry = rstrm->in_base + rstrm->in_reclen; 609 rstrm->in_finger = rstrm->in_base; 610 rstrm->in_reclen = rstrm->in_received = 0; 611 *statp = XPRT_MOREREQS; 612 return TRUE; 613 } 614 } 615 616 *statp = XPRT_MOREREQS; 617 return FALSE; 618 } 619 620 bool_t 621 __xdrrec_setnonblock(xdrs, maxrec) 622 XDR *xdrs; 623 int maxrec; 624 { 625 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 626 627 rstrm->nonblock = TRUE; 628 if (maxrec == 0) 629 maxrec = rstrm->recvsize; 630 rstrm->in_maxrec = maxrec; 631 return TRUE; 632 } 633 634 /* 635 * Internal useful routines 636 */ 637 static bool_t 638 flush_out(rstrm, eor) 639 RECSTREAM *rstrm; 640 bool_t eor; 641 { 642 u_int32_t eormask = (eor == TRUE) ? LAST_FRAG : 0; 643 u_int32_t len = (u_int32_t)((u_long)(rstrm->out_finger) - 644 (u_long)(rstrm->frag_header) - sizeof(u_int32_t)); 645 646 *(rstrm->frag_header) = htonl(len | eormask); 647 len = (u_int32_t)((u_long)(rstrm->out_finger) - 648 (u_long)(rstrm->out_base)); 649 if ((*(rstrm->writeit))(rstrm->tcp_handle, rstrm->out_base, (int)len) 650 != (int)len) 651 return (FALSE); 652 rstrm->frag_header = (u_int32_t *)(void *)rstrm->out_base; 653 rstrm->out_finger = (char *)rstrm->out_base + sizeof(u_int32_t); 654 return (TRUE); 655 } 656 657 static bool_t /* knows nothing about records! Only about input buffers */ 658 fill_input_buf(rstrm) 659 RECSTREAM *rstrm; 660 { 661 char *where; 662 u_int32_t i; 663 int len; 664 665 if (rstrm->nonblock) 666 return FALSE; 667 668 where = rstrm->in_base; 669 i = (u_int32_t)((u_long)rstrm->in_boundry % BYTES_PER_XDR_UNIT); 670 where += i; 671 len = (u_int32_t)(rstrm->in_size - i); 672 if ((len = (*(rstrm->readit))(rstrm->tcp_handle, where, len)) == -1) 673 return (FALSE); 674 rstrm->in_finger = where; 675 where += len; 676 rstrm->in_boundry = where; 677 return (TRUE); 678 } 679 680 static bool_t /* knows nothing about records! Only about input buffers */ 681 get_input_bytes(rstrm, addr, len) 682 RECSTREAM *rstrm; 683 char *addr; 684 int len; 685 { 686 size_t current; 687 688 if (rstrm->nonblock) { 689 if (len > (int)(rstrm->in_boundry - rstrm->in_finger)) 690 return FALSE; 691 memcpy(addr, rstrm->in_finger, (size_t)len); 692 rstrm->in_finger += len; 693 return TRUE; 694 } 695 696 while (len > 0) { 697 current = (size_t)((long)rstrm->in_boundry - 698 (long)rstrm->in_finger); 699 if (current == 0) { 700 if (! fill_input_buf(rstrm)) 701 return (FALSE); 702 continue; 703 } 704 current = (len < current) ? len : current; 705 memmove(addr, rstrm->in_finger, current); 706 rstrm->in_finger += current; 707 addr += current; 708 len -= current; 709 } 710 return (TRUE); 711 } 712 713 static bool_t /* next two bytes of the input stream are treated as a header */ 714 set_input_fragment(rstrm) 715 RECSTREAM *rstrm; 716 { 717 u_int32_t header; 718 719 if (rstrm->nonblock) 720 return FALSE; 721 if (! get_input_bytes(rstrm, (char *)(void *)&header, sizeof(header))) 722 return (FALSE); 723 header = ntohl(header); 724 rstrm->last_frag = ((header & LAST_FRAG) == 0) ? FALSE : TRUE; 725 /* 726 * Sanity check. Try not to accept wildly incorrect 727 * record sizes. Unfortunately, the only record size 728 * we can positively identify as being 'wildly incorrect' 729 * is zero. Ridiculously large record sizes may look wrong, 730 * but we don't have any way to be certain that they aren't 731 * what the client actually intended to send us. 732 */ 733 if (header == 0) 734 return(FALSE); 735 rstrm->fbtbc = header & (~LAST_FRAG); 736 return (TRUE); 737 } 738 739 static bool_t /* consumes input bytes; knows nothing about records! */ 740 skip_input_bytes(rstrm, cnt) 741 RECSTREAM *rstrm; 742 long cnt; 743 { 744 u_int32_t current; 745 746 while (cnt > 0) { 747 current = (size_t)((long)rstrm->in_boundry - 748 (long)rstrm->in_finger); 749 if (current == 0) { 750 if (! fill_input_buf(rstrm)) 751 return (FALSE); 752 continue; 753 } 754 current = (u_int32_t)((cnt < current) ? cnt : current); 755 rstrm->in_finger += current; 756 cnt -= current; 757 } 758 return (TRUE); 759 } 760 761 static u_int 762 fix_buf_size(s) 763 u_int s; 764 { 765 766 if (s < 100) 767 s = 4000; 768 return (RNDUP(s)); 769 } 770 771 /* 772 * Reallocate the input buffer for a non-block stream. 773 */ 774 static bool_t 775 realloc_stream(rstrm, size) 776 RECSTREAM *rstrm; 777 int size; 778 { 779 ptrdiff_t diff; 780 char *buf; 781 782 if (size > rstrm->recvsize) { 783 buf = realloc(rstrm->in_base, (size_t)size); 784 if (buf == NULL) 785 return FALSE; 786 diff = buf - rstrm->in_base; 787 rstrm->in_finger += diff; 788 rstrm->in_base = buf; 789 rstrm->in_boundry = buf + size; 790 rstrm->recvsize = size; 791 rstrm->in_size = size; 792 } 793 794 return TRUE; 795 } 796