rpc.subproj/xdr_rec.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Portions Copyright (c) 1999 Apple Computer, Inc.  All Rights
   7  * Reserved.  This file contains Original Code and/or Modifications of
   8  * Original Code as defined in and that are subject to the Apple Public
   9  * Source License Version 1.1 (the "License").  You may not use this file
  10  * except in compliance with the License.  Please obtain a copy of the
  11  * License at http://www.apple.com/publicsource and read it before using
  12  * this file.
  13  *
  14  * The Original Code and all software distributed under the License are
  15  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  16  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  17  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE OR NON- INFRINGEMENT.  Please see the
  19  * License for the specific language governing rights and limitations
  20  * under the License.
  21  *
  22  * @APPLE_LICENSE_HEADER_END@
  23  */
  24
  25 /*      $NetBSD: xdr_rec.c,v 1.18 2000/07/06 03:10:35 christos Exp $    */
  26
  27 /*
  28  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
  29  * unrestricted use provided that this legend is included on all tape
  30  * media and as a part of the software program in whole or part.  Users
  31  * may copy or modify Sun RPC without charge, but are not authorized
  32  * to license or distribute it to anyone else except as part of a product or
  33  * program developed by the user.
  34  *
  35  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
  36  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
  37  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
  38  *
  39  * Sun RPC is provided with no support and without any obligation on the
  40  * part of Sun Microsystems, Inc. to assist in its use, correction,
  41  * modification or enhancement.
  42  *
  43  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
  44  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
  45  * OR ANY PART THEREOF.
  46  *
  47  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
  48  * or profits or other special, indirect and consequential damages, even if
  49  * Sun has been advised of the possibility of such damages.
  50  *
  51  * Sun Microsystems, Inc.
  52  * 2550 Garcia Avenue
  53  * Mountain View, California  94043
  54  */
  55
  56 #include <sys/cdefs.h>
  57 #if defined(LIBC_SCCS) && !defined(lint)
  58 static char *sccsid = "@(#)xdr_rec.c 1.21 87/08/11 Copyr 1984 Sun Micro";
  59 static char *sccsid = "@(#)xdr_rec.c    2.2 88/08/01 4.0 RPCSRC";
  60 #endif
  61 #include <sys/cdefs.h>
  62
  63 /*
  64  * xdr_rec.c, Implements TCP/IP based XDR streams with a "record marking"
  65  * layer above tcp (for rpc's use).
  66  *
  67  * Copyright (C) 1984, Sun Microsystems, Inc.
  68  *
  69  * These routines interface XDRSTREAMS to a tcp/ip connection.
  70  * There is a record marking layer between the xdr stream
  71  * and the tcp transport level.  A record is composed on one or more
  72  * record fragments.  A record fragment is a thirty-two bit header followed
  73  * by n bytes of data, where n is contained in the header.  The header
  74  * is in network byte order.  Thegh order bit encodes
  75  * whether or not the fragment is the last fragment of the record
  76  * (1 => fragment is last, 0 => more fragments to follow.
  77  * The other 31 bits encode the byte length of the fragment.
  78  */
  79
  80 #include <sys/types.h>
  81
  82 #include <netinet/in.h>
  83
  84 #include <err.h>
  85 #include <stdio.h>
  86 #include <stdlib.h>
  87 #include <string.h>
  88 #include <unistd.h>
  89
  90 #include <rpc/types.h>
  91 #include <rpc/xdr.h>
  92 #include <rpc/auth.h>
  93 #include <rpc/svc.h>
  94 #include <rpc/clnt.h>
  95
  96 #ifdef __LP64__
  97 static bool_t   xdrrec_getlong(XDR *, int *);
  98 static bool_t   xdrrec_putlong(XDR *, const int *);
  99 #else
 100 static bool_t   xdrrec_getlong(XDR *, long *);
 101 static bool_t   xdrrec_putlong(XDR *, const long *);
 102 #endif
 103
 104 static bool_t   xdrrec_getbytes(XDR *, char *, u_int);
 105
 106 static bool_t   xdrrec_putbytes(XDR *, const char *, u_int);
 107 static u_int    xdrrec_getpos(XDR *);
 108 static bool_t   xdrrec_setpos(XDR *, u_int);
 109 static int32_t *xdrrec_inline(XDR *, u_int);
 110 static void     xdrrec_destroy(XDR *);
 111
 112 bool_t __xdrrec_getrec(XDR *, enum xprt_stat *, bool_t);
 113
 114 static const struct  xdr_ops xdrrec_ops = {
 115         xdrrec_getlong,
 116         xdrrec_putlong,
 117         xdrrec_getbytes,
 118         xdrrec_putbytes,
 119         xdrrec_getpos,
 120         xdrrec_setpos,
 121         xdrrec_inline,
 122         xdrrec_destroy
 123 };
 124
 125 /*
 126  * A record is composed of one or more record fragments.
 127  * A record fragment is a four-byte header followed by zero to
 128  * 2**32-1 bytes.  The header is treated as an unsigned 32-bit integer and is
 129  * encode/decoded to the network via htonl/ntohl.  The low order 31 bits
 130  * are a byte count of the fragment.  The highest order bit is a boolean:
 131  * 1 => this fragment is the last fragment of the record,
 132  * 0 => this fragment is followed by more fragment(s).
 133  *
 134  * The fragment/record machinery is not general;  it is constructed to
 135  * meet the needs of xdr and rpc based on tcp.
 136  */
 137
 138 #define LAST_FRAG ((u_int32_t)(1 << 31))
 139
 140 typedef struct rec_strm {
 141         void *tcp_handle;
 142         /*
 143          * out-goung bits
 144          */
 145         int (*writeit)(void *, void *, int);
 146         char *out_base; /* output buffer (points to frag header) */
 147         char *out_finger;       /* next output position */
 148         char *out_boundry;      /* data cannot up to this address */
 149         u_int32_t *frag_header; /* beginning of curren fragment */
 150         bool_t frag_sent;       /* true if buffer sent in middle of record */
 151         /*
 152          * in-coming bits
 153          */
 154         int (*readit)(void *, void *, int);
 155         size_t in_size; /* fixed size of the input buffer */
 156         char *in_base;
 157         char *in_finger;        /* location of next byte to be had */
 158         char *in_boundry;       /* can read up to this location */
 159         int fbtbc;              /* fragment bytes to be consumed */
 160         bool_t last_frag;
 161         u_int sendsize;
 162         u_int recvsize;
 163
 164         bool_t nonblock;
 165         bool_t in_haveheader;
 166         u_int32_t in_header;
 167         char *in_hdrp;
 168         int in_hdrlen;
 169         int in_reclen;
 170         int in_received;
 171         int in_maxrec;
 172 } RECSTREAM;
 173
 174 static u_int    fix_buf_size(u_int);
 175 static bool_t   flush_out(RECSTREAM *, bool_t);
 176 static bool_t   fill_input_buf(RECSTREAM *);
 177 static bool_t   get_input_bytes(RECSTREAM *, char *, int);
 178 static bool_t   set_input_fragment(RECSTREAM *);
 179 static bool_t   skip_input_bytes(RECSTREAM *, int);
 180 static bool_t   realloc_stream(RECSTREAM *, int);
 181
 182
 183 /*
 184  * Create an xdr handle for xdrrec
 185  * xdrrec_create fills in xdrs.  Sendsize and recvsize are
 186  * send and recv buffer sizes (0 => use default).
 187  * tcp_handle is an opaque handle that is passed as the first parameter to
 188  * the procedures readit and writeit.  Readit and writeit are read and
 189  * write respectively.   They are like the system
 190  * calls expect that they take an opaque handle rather than an fd.
 191  */
 192 void
 193 xdrrec_create(xdrs, sendsize, recvsize, tcp_handle, readit, writeit)
 194         XDR *xdrs;
 195         u_int sendsize;
 196         u_int recvsize;
 197         void *tcp_handle;
 198         /* like read, but pass it a tcp_handle, not sock */
 199         int (*readit)(void *, void *, int);
 200         /* like write, but pass it a tcp_handle, not sock */
 201         int (*writeit)(void *, void *, int);
 202 {
 203         RECSTREAM *rstrm = mem_alloc(sizeof(RECSTREAM));
 204
 205         if (rstrm == NULL) {
 206                 warnx("xdrrec_create: out of memory");
 207                 /*
 208                  *  This is bad.  Should rework xdrrec_create to
 209                  *  return a handle, and in this case return NULL
 210                  */
 211                 return;
 212         }
 213         rstrm->sendsize = sendsize = fix_buf_size(sendsize);
 214         rstrm->out_base = mem_alloc(rstrm->sendsize);
 215         if (rstrm->out_base == NULL) {
 216                 warnx("xdrrec_create: out of memory");
 217                 mem_free(rstrm, sizeof(RECSTREAM));
 218                 return;
 219         }
 220         rstrm->recvsize = recvsize = fix_buf_size(recvsize);
 221         rstrm->in_base = mem_alloc(recvsize);
 222         if (rstrm->in_base == NULL) {
 223                 warnx("xdrrec_create: out of memory");
 224                 mem_free(rstrm->out_base, sendsize);
 225                 mem_free(rstrm, sizeof(RECSTREAM));
 226                 return;
 227         }
 228         /*
 229          * now the rest ...
 230          */
 231         xdrs->x_ops = &xdrrec_ops;
 232         xdrs->x_private = rstrm;
 233         rstrm->tcp_handle = tcp_handle;
 234         rstrm->readit = readit;
 235         rstrm->writeit = writeit;
 236         rstrm->out_finger = rstrm->out_boundry = rstrm->out_base;
 237         rstrm->frag_header = (u_int32_t *)(void *)rstrm->out_base;
 238         rstrm->out_finger += sizeof(u_int32_t);
 239         rstrm->out_boundry += sendsize;
 240         rstrm->frag_sent = FALSE;
 241         rstrm->in_size = recvsize;
 242         rstrm->in_boundry = rstrm->in_base;
 243         rstrm->in_finger = (rstrm->in_boundry += recvsize);
 244         rstrm->fbtbc = 0;
 245         rstrm->last_frag = TRUE;
 246         rstrm->in_haveheader = FALSE;
 247         rstrm->in_hdrlen = 0;
 248         rstrm->in_hdrp = (char *)(void *)&rstrm->in_header;
 249         rstrm->nonblock = FALSE;
 250         rstrm->in_reclen = 0;
 251         rstrm->in_received = 0;
 252 }
 253
 254
 255 /*
 256  * The reoutines defined below are the xdr ops which will go into the
 257  * xdr handle filled in by xdrrec_create.
 258  */
 259
 260 static bool_t
 261 xdrrec_getlong(xdrs, lp)
 262         XDR *xdrs;
 263 #ifdef __LP64__
 264         int *lp;
 265 #else
 266         long *lp;
 267 #endif
 268 {
 269         RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
 270         int32_t *buflp = (int32_t *)(void *)(rstrm->in_finger);
 271         int32_t mylong;
 272
 273         /* first try the inline, fast case */
 274         if ((rstrm->fbtbc >= sizeof(int32_t)) && ((rstrm->in_boundry - (char *)buflp) >= sizeof(int32_t)))
 275         {
 276                 *lp = ntohl(*buflp);
 277                 rstrm->fbtbc -= sizeof(int32_t);
 278                 rstrm->in_finger += sizeof(int32_t);
 279         }
 280         else
 281         {
 282                 if (! xdrrec_getbytes(xdrs, (char *)(void *)&mylong, sizeof(int32_t))) return (FALSE);
 283                 *lp = ntohl(mylong);
 284         }
 285
 286         return (TRUE);
 287 }
 288
 289 static bool_t
 290 xdrrec_putlong(xdrs, lp)
 291         XDR *xdrs;
 292 #ifdef __LP64__
 293         const int *lp;
 294 #else
 295         const long *lp;
 296 #endif
 297 {
 298         RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
 299         int32_t *dest_lp = ((int32_t *)(void *)(rstrm->out_finger));
 300
 301         if ((rstrm->out_finger += sizeof(int32_t)) > rstrm->out_boundry)
 302         {
 303                 /*
 304                  * this case should almost never happen so the code is
 305                  * inefficient
 306                  */
 307                 rstrm->out_finger -= sizeof(int32_t);
 308                 rstrm->frag_sent = TRUE;
 309                 if (! flush_out(rstrm, FALSE)) return (FALSE);
 310                 dest_lp = ((int32_t *)(void *)(rstrm->out_finger));
 311                 rstrm->out_finger += sizeof(int32_t);
 312         }
 313
 314         *dest_lp = htonl(*lp);
 315         return (TRUE);
 316 }
 317
 318 static bool_t  /* must manage buffers, fragments, and records */
 319 xdrrec_getbytes(xdrs, addr, len)
 320         XDR *xdrs;
 321         char *addr;
 322         u_int len;
 323 {
 324         RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
 325         int current;
 326
 327         while (len > 0) {
 328                 current = (int)rstrm->fbtbc;
 329                 if (current == 0) {
 330                         if (rstrm->last_frag)
 331                                 return (FALSE);
 332                         if (! set_input_fragment(rstrm))
 333                                 return (FALSE);
 334                         continue;
 335                 }
 336                 current = (len < current) ? len : current;
 337                 if (! get_input_bytes(rstrm, addr, current))
 338                         return (FALSE);
 339                 addr += current;
 340                 rstrm->fbtbc -= current;
 341                 len -= current;
 342         }
 343         return (TRUE);
 344 }
 345
 346 static bool_t
 347 xdrrec_putbytes(xdrs, addr, len)
 348         XDR *xdrs;
 349         const char *addr;
 350         u_int len;
 351 {
 352         RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
 353         size_t current;
 354
 355         while (len > 0) {
 356                 current = (size_t)(rstrm->out_boundry - rstrm->out_finger);
 357                 current = (len < current) ? len : current;
 358                 memmove(rstrm->out_finger, addr, current);
 359                 rstrm->out_finger += current;
 360                 addr += current;
 361                 len -= current;
 362                 if (rstrm->out_finger == rstrm->out_boundry) {
 363                         rstrm->frag_sent = TRUE;
 364                         if (! flush_out(rstrm, FALSE))
 365                                 return (FALSE);
 366                 }
 367         }
 368         return (TRUE);
 369 }
 370
 371 static u_int
 372 xdrrec_getpos(xdrs)
 373         XDR *xdrs;
 374 {
 375         RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
 376         off_t pos;
 377         int hfd;
 378
 379         /* tcp_handle is in actual fact just a file descriptor */
 380         hfd = 0;
 381         memcpy(&hfd, rstrm->tcp_handle, sizeof(hfd));
 382
 383         pos = lseek(hfd, 0, 1);
 384         if (pos != -1)
 385                 switch (xdrs->x_op) {
 386
 387                 case XDR_ENCODE:
 388                         pos += rstrm->out_finger - rstrm->out_base;
 389                         break;
 390
 391                 case XDR_DECODE:
 392                         pos -= rstrm->in_boundry - rstrm->in_finger;
 393                         break;
 394
 395                 default:
 396                         pos = (off_t) -1;
 397                         break;
 398                 }
 399         return ((u_int) pos);
 400 }
 401
 402 static bool_t
 403 xdrrec_setpos(xdrs, pos)
 404         XDR *xdrs;
 405         u_int pos;
 406 {
 407         RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
 408         u_int currpos = xdrrec_getpos(xdrs);
 409         int delta = currpos - pos;
 410         char *newpos;
 411
 412         if ((int)currpos != -1)
 413                 switch (xdrs->x_op) {
 414
 415                 case XDR_ENCODE:
 416                         newpos = rstrm->out_finger - delta;
 417                         if ((newpos > (char *)(void *)(rstrm->frag_header)) &&
 418                                 (newpos < rstrm->out_boundry)) {
 419                                 rstrm->out_finger = newpos;
 420                                 return (TRUE);
 421                         }
 422                         break;
 423
 424                 case XDR_DECODE:
 425                         newpos = rstrm->in_finger - delta;
 426                         if ((delta < (int)(rstrm->fbtbc)) &&
 427                                 (newpos <= rstrm->in_boundry) &&
 428                                 (newpos >= rstrm->in_base)) {
 429                                 rstrm->in_finger = newpos;
 430                                 rstrm->fbtbc -= delta;
 431                                 return (TRUE);
 432                         }
 433                         break;
 434
 435                 case XDR_FREE:
 436                         break;
 437                 }
 438         return (FALSE);
 439 }
 440
 441 static int32_t *
 442 xdrrec_inline(xdrs, len)
 443         XDR *xdrs;
 444         u_int len;
 445 {
 446         RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
 447         int32_t *buf = NULL;
 448
 449         switch (xdrs->x_op) {
 450
 451         case XDR_ENCODE:
 452                 if ((rstrm->out_finger + len) <= rstrm->out_boundry) {
 453                         buf = (int32_t *)(void *)rstrm->out_finger;
 454                         rstrm->out_finger += len;
 455                 }
 456                 break;
 457
 458         case XDR_DECODE:
 459                 if ((len <= rstrm->fbtbc) &&
 460                         ((rstrm->in_finger + len) <= rstrm->in_boundry)) {
 461                         buf = (int32_t *)(void *)rstrm->in_finger;
 462                         rstrm->fbtbc -= len;
 463                         rstrm->in_finger += len;
 464                 }
 465                 break;
 466
 467         case XDR_FREE:
 468                 break;
 469         }
 470         return (buf);
 471 }
 472
 473 static void
 474 xdrrec_destroy(xdrs)
 475         XDR *xdrs;
 476 {
 477         RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
 478
 479         mem_free(rstrm->out_base, rstrm->sendsize);
 480         mem_free(rstrm->in_base, rstrm->recvsize);
 481         mem_free(rstrm, sizeof(RECSTREAM));
 482 }
 483
 484
 485 /*
 486  * Exported routines to manage xdr records
 487  */
 488
 489 /*
 490  * Before reading (deserializing from the stream, one should always call
 491  * this procedure to guarantee proper record alignment.
 492  */
 493 bool_t
 494 xdrrec_skiprecord(xdrs)
 495         XDR *xdrs;
 496 {
 497         RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
 498         enum xprt_stat xstat;
 499
 500         if (rstrm->nonblock) {
 501                 if (__xdrrec_getrec(xdrs, &xstat, FALSE)) {
 502                         rstrm->fbtbc = 0;
 503                         return TRUE;
 504                 }
 505                 if (rstrm->in_finger == rstrm->in_boundry &&
 506                     xstat == XPRT_MOREREQS) {
 507                         rstrm->fbtbc = 0;
 508                         return TRUE;
 509                 }
 510                 return FALSE;
 511         }
 512
 513         while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) {
 514                 if (! skip_input_bytes(rstrm, rstrm->fbtbc))
 515                         return (FALSE);
 516                 rstrm->fbtbc = 0;
 517                 if ((! rstrm->last_frag) && (! set_input_fragment(rstrm)))
 518                         return (FALSE);
 519         }
 520         rstrm->last_frag = FALSE;
 521         return (TRUE);
 522 }
 523
 524 /*
 525  * Look ahead function.
 526  * Returns TRUE iff there is no more input in the buffer
 527  * after consuming the rest of the current record.
 528  */
 529 bool_t
 530 xdrrec_eof(xdrs)
 531         XDR *xdrs;
 532 {
 533         RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
 534
 535         while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) {
 536                 if (! skip_input_bytes(rstrm, rstrm->fbtbc))
 537                         return (TRUE);
 538                 rstrm->fbtbc = 0;
 539                 if ((! rstrm->last_frag) && (! set_input_fragment(rstrm)))
 540                         return (TRUE);
 541         }
 542         if (rstrm->in_finger == rstrm->in_boundry)
 543                 return (TRUE);
 544         return (FALSE);
 545 }
 546
 547 /*
 548  * The client must tell the package when an end-of-record has occurred.
 549  * The second paraemters tells whether the record should be flushed to the
 550  * (output) tcp stream.  (This let's the package support batched or
 551  * pipelined procedure calls.)  TRUE => immmediate flush to tcp connection.
 552  */
 553 bool_t
 554 xdrrec_endofrecord(xdrs, sendnow)
 555         XDR *xdrs;
 556         bool_t sendnow;
 557 {
 558         RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
 559         unsigned int len;  /* fragment length */
 560
 561         if (sendnow || rstrm->frag_sent ||
 562                 (rstrm->out_finger + sizeof(u_int32_t) >= rstrm->out_boundry)) {
 563                 rstrm->frag_sent = FALSE;
 564                 return (flush_out(rstrm, TRUE));
 565         }
 566         len = rstrm->out_finger - (char *)(rstrm->frag_header) - sizeof(u_int32_t);
 567         *(rstrm->frag_header) = htonl(len | LAST_FRAG);
 568         rstrm->frag_header = (u_int32_t *)(void *)rstrm->out_finger;
 569         rstrm->out_finger += sizeof(u_int32_t);
 570         return (TRUE);
 571 }
 572
 573 /*
 574  * Fill the stream buffer with a record for a non-blocking connection.
 575  * Return true if a record is available in the buffer, false if not.
 576  */
 577 bool_t
 578 __xdrrec_getrec(xdrs, statp, expectdata)
 579         XDR *xdrs;
 580         enum xprt_stat *statp;
 581         bool_t expectdata;
 582 {
 583         RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
 584         ssize_t n;
 585         int fraglen;
 586
 587         if (!rstrm->in_haveheader) {
 588                 n = rstrm->readit(rstrm->tcp_handle, rstrm->in_hdrp,
 589                     (int)sizeof (rstrm->in_header) - rstrm->in_hdrlen);
 590                 if (n == 0) {
 591                         *statp = expectdata ? XPRT_DIED : XPRT_IDLE;
 592                         return FALSE;
 593                 }
 594                 if (n < 0) {
 595                         *statp = XPRT_DIED;
 596                         return FALSE;
 597                 }
 598                 rstrm->in_hdrp += n;
 599                 rstrm->in_hdrlen += n;
 600                 if (rstrm->in_hdrlen < sizeof (rstrm->in_header)) {
 601                         *statp = XPRT_MOREREQS;
 602                         return FALSE;
 603                 }
 604                 rstrm->in_header = ntohl(rstrm->in_header);
 605                 fraglen = (int)(rstrm->in_header & ~LAST_FRAG);
 606                 if (fraglen == 0 || fraglen > rstrm->in_maxrec ||
 607                     (rstrm->in_reclen + fraglen) > rstrm->in_maxrec) {
 608                         *statp = XPRT_DIED;
 609                         return FALSE;
 610                 }
 611                 rstrm->in_reclen += fraglen;
 612                 if (rstrm->in_reclen > rstrm->recvsize)
 613                         realloc_stream(rstrm, rstrm->in_reclen);
 614                 if (rstrm->in_header & LAST_FRAG) {
 615                         rstrm->in_header &= ~LAST_FRAG;
 616                         rstrm->last_frag = TRUE;
 617                 }
 618         }
 619
 620         n =  rstrm->readit(rstrm->tcp_handle,
 621             rstrm->in_base + rstrm->in_received,
 622             (rstrm->in_reclen - rstrm->in_received));
 623
 624         if (n < 0) {
 625                 *statp = XPRT_DIED;
 626                 return FALSE;
 627         }
 628
 629         if (n == 0) {
 630                 *statp = expectdata ? XPRT_DIED : XPRT_IDLE;
 631                 return FALSE;
 632         }
 633
 634         rstrm->in_received += n;
 635
 636         if (rstrm->in_received == rstrm->in_reclen) {
 637                 rstrm->in_haveheader = FALSE;
 638                 rstrm->in_hdrp = (char *)(void *)&rstrm->in_header;
 639                 rstrm->in_hdrlen = 0;
 640                 if (rstrm->last_frag) {
 641                         rstrm->fbtbc = rstrm->in_reclen;
 642                         rstrm->in_boundry = rstrm->in_base + rstrm->in_reclen;
 643                         rstrm->in_finger = rstrm->in_base;
 644                         rstrm->in_reclen = rstrm->in_received = 0;
 645                         *statp = XPRT_MOREREQS;
 646                         return TRUE;
 647                 }
 648         }
 649
 650         *statp = XPRT_MOREREQS;
 651         return FALSE;
 652 }
 653
 654 bool_t
 655 __xdrrec_setnonblock(xdrs, maxrec)
 656         XDR *xdrs;
 657         int maxrec;
 658 {
 659         RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
 660
 661         rstrm->nonblock = TRUE;
 662         if (maxrec == 0)
 663                 maxrec = rstrm->recvsize;
 664         rstrm->in_maxrec = maxrec;
 665         return TRUE;
 666 }
 667
 668 /*
 669  * Internal useful routines
 670  */
 671 static bool_t
 672 flush_out(rstrm, eor)
 673         RECSTREAM *rstrm;
 674         bool_t eor;
 675 {
 676         u_int32_t eormask = (eor == TRUE) ? LAST_FRAG : 0;
 677         u_int32_t len = rstrm->out_finger - (char *)(rstrm->frag_header) - sizeof(u_int32_t);
 678
 679         *(rstrm->frag_header) = htonl(len | eormask);
 680         len = rstrm->out_finger - rstrm->out_base;
 681         if ((*(rstrm->writeit))(rstrm->tcp_handle, rstrm->out_base, len) != len)
 682                 return (FALSE);
 683         rstrm->frag_header = (u_int32_t *)(void *)rstrm->out_base;
 684         rstrm->out_finger = (char *)rstrm->out_base + sizeof(u_int32_t);
 685         return (TRUE);
 686 }
 687
 688 static bool_t  /* knows nothing about records!  Only about input buffers */
 689 fill_input_buf(rstrm)
 690         RECSTREAM *rstrm;
 691 {
 692         char *where;
 693         u_int32_t i;
 694         int len;
 695
 696         if (rstrm->nonblock)
 697                 return FALSE;
 698
 699         where = rstrm->in_base;
 700         i = (size_t)(rstrm->in_boundry) % BYTES_PER_XDR_UNIT;
 701         where += i;
 702         len = rstrm->in_size - i;
 703         if ((len = (*(rstrm->readit))(rstrm->tcp_handle, where, len)) == -1)
 704                 return (FALSE);
 705         rstrm->in_finger = where;
 706         where += len;
 707         rstrm->in_boundry = where;
 708         return (TRUE);
 709 }
 710
 711 static bool_t  /* knows nothing about records!  Only about input buffers */
 712 get_input_bytes(rstrm, addr, len)
 713         RECSTREAM *rstrm;
 714         char *addr;
 715         int len;
 716 {
 717         size_t current;
 718
 719         if (rstrm->nonblock) {
 720                 if (len > (int)(rstrm->in_boundry - rstrm->in_finger))
 721                         return FALSE;
 722                 memcpy(addr, rstrm->in_finger, (size_t)len);
 723                 rstrm->in_finger += len;
 724                 return TRUE;
 725         }
 726
 727         while (len > 0) {
 728                 current = (size_t)(rstrm->in_boundry - rstrm->in_finger);
 729                 if (current == 0) {
 730                         if (! fill_input_buf(rstrm))
 731                                 return (FALSE);
 732                         continue;
 733                 }
 734                 current = (len < current) ? len : current;
 735                 memmove(addr, rstrm->in_finger, current);
 736                 rstrm->in_finger += current;
 737                 addr += current;
 738                 len -= current;
 739         }
 740         return (TRUE);
 741 }
 742
 743 static bool_t  /* next two bytes of the input stream are treated as a header */
 744 set_input_fragment(rstrm)
 745         RECSTREAM *rstrm;
 746 {
 747         u_int32_t header;
 748
 749         if (rstrm->nonblock)
 750                 return FALSE;
 751         if (! get_input_bytes(rstrm, (char *)(void *)&header, sizeof(header)))
 752                 return (FALSE);
 753         header = ntohl(header);
 754         rstrm->last_frag = ((header & LAST_FRAG) == 0) ? FALSE : TRUE;
 755         /*
 756          * Sanity check. Try not to accept wildly incorrect
 757          * record sizes. Unfortunately, the only record size
 758          * we can positively identify as being 'wildly incorrect'
 759          * is zero. Ridiculously large record sizes may look wrong,
 760          * but we don't have any way to be certain that they aren't
 761          * what the client actually intended to send us.
 762          */
 763         if (header == 0)
 764                 return(FALSE);
 765         rstrm->fbtbc = header & (~LAST_FRAG);
 766         return (TRUE);
 767 }
 768
 769 static bool_t  /* consumes input bytes; knows nothing about records! */
 770 skip_input_bytes(rstrm, cnt)
 771         RECSTREAM *rstrm;
 772         int cnt;
 773 {
 774         u_int32_t current;
 775
 776         while (cnt > 0) {
 777                 current = (size_t)(rstrm->in_boundry - rstrm->in_finger);
 778                 if (current == 0) {
 779                         if (! fill_input_buf(rstrm))
 780                                 return (FALSE);
 781                         continue;
 782                 }
 783                 current = (cnt < current) ? cnt : current;
 784                 rstrm->in_finger += current;
 785                 cnt -= current;
 786         }
 787         return (TRUE);
 788 }
 789
 790 static u_int
 791 fix_buf_size(s)
 792         u_int s;
 793 {
 794
 795         if (s < 100)
 796                 s = 4000;
 797         return (RNDUP(s));
 798 }
 799
 800 /*
 801  * Reallocate the input buffer for a non-block stream.
 802  */
 803 static bool_t
 804 realloc_stream(rstrm, size)
 805         RECSTREAM *rstrm;
 806         int size;
 807 {
 808         int diff;
 809         char *buf;
 810
 811         if (size > rstrm->recvsize) {
 812                 buf = realloc(rstrm->in_base, (size_t)size);
 813                 if (buf == NULL)
 814                         return FALSE;
 815                 diff = buf - rstrm->in_base;
 816                 rstrm->in_finger += diff;
 817                 rstrm->in_base = buf;
 818                 rstrm->in_boundry = buf + size;
 819                 rstrm->recvsize = size;
 820                 rstrm->in_size = size;
 821         }
 822
 823         return TRUE;
 824 }