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 represented as a htonl(u_long).  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
  89 #include <rpc/types.h>
  90 #include <rpc/xdr.h>
  91 #include <rpc/auth.h>
  92 #include <rpc/svc.h>
  93 #include <rpc/clnt.h>
  94
  95 static bool_t   xdrrec_getlong(XDR *, long *);
  96 static bool_t   xdrrec_putlong(XDR *, const long *);
  97 static bool_t   xdrrec_getbytes(XDR *, char *, u_int);
  98
  99 static bool_t   xdrrec_putbytes(XDR *, const char *, u_int);
 100 static u_int    xdrrec_getpos(XDR *);
 101 static bool_t   xdrrec_setpos(XDR *, u_int);
 102 static int32_t *xdrrec_inline(XDR *, u_int);
 103 static void     xdrrec_destroy(XDR *);
 104
 105 static const struct  xdr_ops xdrrec_ops = {
 106         xdrrec_getlong,
 107         xdrrec_putlong,
 108         xdrrec_getbytes,
 109         xdrrec_putbytes,
 110         xdrrec_getpos,
 111         xdrrec_setpos,
 112         xdrrec_inline,
 113         xdrrec_destroy
 114 };
 115
 116 /*
 117  * A record is composed of one or more record fragments.
 118  * A record fragment is a four-byte header followed by zero to
 119  * 2**32-1 bytes.  The header is treated as a long unsigned and is
 120  * encode/decoded to the network via htonl/ntohl.  The low order 31 bits
 121  * are a byte count of the fragment.  The highest order bit is a boolean:
 122  * 1 => this fragment is the last fragment of the record,
 123  * 0 => this fragment is followed by more fragment(s).
 124  *
 125  * The fragment/record machinery is not general;  it is constructed to
 126  * meet the needs of xdr and rpc based on tcp.
 127  */
 128
 129 #define LAST_FRAG ((u_int32_t)(1 << 31))
 130
 131 typedef struct rec_strm {
 132         char *tcp_handle;
 133         /*
 134          * out-goung bits
 135          */
 136         int (*writeit)(void *, void *, int);
 137         char *out_base; /* output buffer (points to frag header) */
 138         char *out_finger;       /* next output position */
 139         char *out_boundry;      /* data cannot up to this address */
 140         u_int32_t *frag_header; /* beginning of curren fragment */
 141         bool_t frag_sent;       /* true if buffer sent in middle of record */
 142         /*
 143          * in-coming bits
 144          */
 145         int (*readit)(void *, void *, int);
 146         u_long in_size; /* fixed size of the input buffer */
 147         char *in_base;
 148         char *in_finger;        /* location of next byte to be had */
 149         char *in_boundry;       /* can read up to this location */
 150         long fbtbc;             /* fragment bytes to be consumed */
 151         bool_t last_frag;
 152         u_int sendsize;
 153         u_int recvsize;
 154
 155         bool_t nonblock;
 156         bool_t in_haveheader;
 157         u_int32_t in_header;
 158         char *in_hdrp;
 159         int in_hdrlen;
 160         int in_reclen;
 161         int in_received;
 162         int in_maxrec;
 163 } RECSTREAM;
 164
 165 static u_int    fix_buf_size(u_int);
 166 static bool_t   flush_out(RECSTREAM *, bool_t);
 167 static bool_t   fill_input_buf(RECSTREAM *);
 168 static bool_t   get_input_bytes(RECSTREAM *, char *, int);
 169 static bool_t   set_input_fragment(RECSTREAM *);
 170 static bool_t   skip_input_bytes(RECSTREAM *, long);
 171 static bool_t   realloc_stream(RECSTREAM *, int);
 172
 173
 174 /*
 175  * Create an xdr handle for xdrrec
 176  * xdrrec_create fills in xdrs.  Sendsize and recvsize are
 177  * send and recv buffer sizes (0 => use default).
 178  * tcp_handle is an opaque handle that is passed as the first parameter to
 179  * the procedures readit and writeit.  Readit and writeit are read and
 180  * write respectively.   They are like the system
 181  * calls expect that they take an opaque handle rather than an fd.
 182  */
 183 void
 184 xdrrec_create(xdrs, sendsize, recvsize, tcp_handle, readit, writeit)
 185         XDR *xdrs;
 186         u_int sendsize;
 187         u_int recvsize;
 188         void *tcp_handle;
 189         /* like read, but pass it a tcp_handle, not sock */
 190         int (*readit)(void *, void *, int);
 191         /* like write, but pass it a tcp_handle, not sock */
 192         int (*writeit)(void *, void *, int);
 193 {
 194         RECSTREAM *rstrm = mem_alloc(sizeof(RECSTREAM));
 195
 196         if (rstrm == NULL) {
 197                 warnx("xdrrec_create: out of memory");
 198                 /*
 199                  *  This is bad.  Should rework xdrrec_create to
 200                  *  return a handle, and in this case return NULL
 201                  */
 202                 return;
 203         }
 204         rstrm->sendsize = sendsize = fix_buf_size(sendsize);
 205         rstrm->out_base = mem_alloc(rstrm->sendsize);
 206         if (rstrm->out_base == NULL) {
 207                 warnx("xdrrec_create: out of memory");
 208                 mem_free(rstrm, sizeof(RECSTREAM));
 209                 return;
 210         }
 211         rstrm->recvsize = recvsize = fix_buf_size(recvsize);
 212         rstrm->in_base = mem_alloc(recvsize);
 213         if (rstrm->in_base == NULL) {
 214                 warnx("xdrrec_create: out of memory");
 215                 mem_free(rstrm->out_base, sendsize);
 216                 mem_free(rstrm, sizeof(RECSTREAM));
 217                 return;
 218         }
 219         /*
 220          * now the rest ...
 221          */
 222         xdrs->x_ops = &xdrrec_ops;
 223         xdrs->x_private = rstrm;
 224         rstrm->tcp_handle = tcp_handle;
 225         rstrm->readit = readit;
 226         rstrm->writeit = writeit;
 227         rstrm->out_finger = rstrm->out_boundry = rstrm->out_base;
 228         rstrm->frag_header = (u_int32_t *)(void *)rstrm->out_base;
 229         rstrm->out_finger += sizeof(u_int32_t);
 230         rstrm->out_boundry += sendsize;
 231         rstrm->frag_sent = FALSE;
 232         rstrm->in_size = recvsize;
 233         rstrm->in_boundry = rstrm->in_base;
 234         rstrm->in_finger = (rstrm->in_boundry += recvsize);
 235         rstrm->fbtbc = 0;
 236         rstrm->last_frag = TRUE;
 237         rstrm->in_haveheader = FALSE;
 238         rstrm->in_hdrlen = 0;
 239         rstrm->in_hdrp = (char *)(void *)&rstrm->in_header;
 240         rstrm->nonblock = FALSE;
 241         rstrm->in_reclen = 0;
 242         rstrm->in_received = 0;
 243 }
 244
 245
 246 /*
 247  * The reoutines defined below are the xdr ops which will go into the
 248  * xdr handle filled in by xdrrec_create.
 249  */
 250
 251 static bool_t
 252 xdrrec_getlong(xdrs, lp)
 253         XDR *xdrs;
 254         long *lp;
 255 {
 256         RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
 257         int32_t *buflp = (int32_t *)(void *)(rstrm->in_finger);
 258         int32_t mylong;
 259
 260         /* first try the inline, fast case */
 261         if ((rstrm->fbtbc >= sizeof(int32_t)) &&
 262                 (((long)rstrm->in_boundry - (long)buflp) >= sizeof(int32_t))) {
 263                 *lp = (long)ntohl((u_int32_t)(*buflp));
 264                 rstrm->fbtbc -= sizeof(int32_t);
 265                 rstrm->in_finger += sizeof(int32_t);
 266         } else {
 267                 if (! xdrrec_getbytes(xdrs, (char *)(void *)&mylong,
 268                     sizeof(int32_t)))
 269                         return (FALSE);
 270                 *lp = (long)ntohl((u_int32_t)mylong);
 271         }
 272         return (TRUE);
 273 }
 274
 275 static bool_t
 276 xdrrec_putlong(xdrs, lp)
 277         XDR *xdrs;
 278         const long *lp;
 279 {
 280         RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
 281         int32_t *dest_lp = ((int32_t *)(void *)(rstrm->out_finger));
 282
 283         if ((rstrm->out_finger += sizeof(int32_t)) > rstrm->out_boundry) {
 284                 /*
 285                  * this case should almost never happen so the code is
 286                  * inefficient
 287                  */
 288                 rstrm->out_finger -= sizeof(int32_t);
 289                 rstrm->frag_sent = TRUE;
 290                 if (! flush_out(rstrm, FALSE))
 291                         return (FALSE);
 292                 dest_lp = ((int32_t *)(void *)(rstrm->out_finger));
 293                 rstrm->out_finger += sizeof(int32_t);
 294         }
 295         *dest_lp = (int32_t)htonl((u_int32_t)(*lp));
 296         return (TRUE);
 297 }
 298
 299 static bool_t  /* must manage buffers, fragments, and records */
 300 xdrrec_getbytes(xdrs, addr, len)
 301         XDR *xdrs;
 302         char *addr;
 303         u_int len;
 304 {
 305         RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
 306         int current;
 307
 308         while (len > 0) {
 309                 current = (int)rstrm->fbtbc;
 310                 if (current == 0) {
 311                         if (rstrm->last_frag)
 312                                 return (FALSE);
 313                         if (! set_input_fragment(rstrm))
 314                                 return (FALSE);
 315                         continue;
 316                 }
 317                 current = (len < current) ? len : current;
 318                 if (! get_input_bytes(rstrm, addr, current))
 319                         return (FALSE);
 320                 addr += current;
 321                 rstrm->fbtbc -= current;
 322                 len -= current;
 323         }
 324         return (TRUE);
 325 }
 326
 327 static bool_t
 328 xdrrec_putbytes(xdrs, addr, len)
 329         XDR *xdrs;
 330         const char *addr;
 331         u_int len;
 332 {
 333         RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
 334         size_t current;
 335
 336         while (len > 0) {
 337                 current = (size_t)((u_long)rstrm->out_boundry -
 338                     (u_long)rstrm->out_finger);
 339                 current = (len < current) ? len : current;
 340                 memmove(rstrm->out_finger, addr, current);
 341                 rstrm->out_finger += current;
 342                 addr += current;
 343                 len -= current;
 344                 if (rstrm->out_finger == rstrm->out_boundry) {
 345                         rstrm->frag_sent = TRUE;
 346                         if (! flush_out(rstrm, FALSE))
 347                                 return (FALSE);
 348                 }
 349         }
 350         return (TRUE);
 351 }
 352
 353 static u_int
 354 xdrrec_getpos(xdrs)
 355         XDR *xdrs;
 356 {
 357         RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
 358         off_t pos;
 359
 360         pos = lseek((int)(u_long)rstrm->tcp_handle, (off_t)0, 1);
 361         if (pos != -1)
 362                 switch (xdrs->x_op) {
 363
 364                 case XDR_ENCODE:
 365                         pos += rstrm->out_finger - rstrm->out_base;
 366                         break;
 367
 368                 case XDR_DECODE:
 369                         pos -= rstrm->in_boundry - rstrm->in_finger;
 370                         break;
 371
 372                 default:
 373                         pos = (off_t) -1;
 374                         break;
 375                 }
 376         return ((u_int) pos);
 377 }
 378
 379 static bool_t
 380 xdrrec_setpos(xdrs, pos)
 381         XDR *xdrs;
 382         u_int pos;
 383 {
 384         RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
 385         u_int currpos = xdrrec_getpos(xdrs);
 386         int delta = currpos - pos;
 387         char *newpos;
 388
 389         if ((int)currpos != -1)
 390                 switch (xdrs->x_op) {
 391
 392                 case XDR_ENCODE:
 393                         newpos = rstrm->out_finger - delta;
 394                         if ((newpos > (char *)(void *)(rstrm->frag_header)) &&
 395                                 (newpos < rstrm->out_boundry)) {
 396                                 rstrm->out_finger = newpos;
 397                                 return (TRUE);
 398                         }
 399                         break;
 400
 401                 case XDR_DECODE:
 402                         newpos = rstrm->in_finger - delta;
 403                         if ((delta < (int)(rstrm->fbtbc)) &&
 404                                 (newpos <= rstrm->in_boundry) &&
 405                                 (newpos >= rstrm->in_base)) {
 406                                 rstrm->in_finger = newpos;
 407                                 rstrm->fbtbc -= delta;
 408                                 return (TRUE);
 409                         }
 410                         break;
 411
 412                 case XDR_FREE:
 413                         break;
 414                 }
 415         return (FALSE);
 416 }
 417
 418 static int32_t *
 419 xdrrec_inline(xdrs, len)
 420         XDR *xdrs;
 421         u_int len;
 422 {
 423         RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
 424         int32_t *buf = NULL;
 425
 426         switch (xdrs->x_op) {
 427
 428         case XDR_ENCODE:
 429                 if ((rstrm->out_finger + len) <= rstrm->out_boundry) {
 430                         buf = (int32_t *)(void *)rstrm->out_finger;
 431                         rstrm->out_finger += len;
 432                 }
 433                 break;
 434
 435         case XDR_DECODE:
 436                 if ((len <= rstrm->fbtbc) &&
 437                         ((rstrm->in_finger + len) <= rstrm->in_boundry)) {
 438                         buf = (int32_t *)(void *)rstrm->in_finger;
 439                         rstrm->fbtbc -= len;
 440                         rstrm->in_finger += len;
 441                 }
 442                 break;
 443
 444         case XDR_FREE:
 445                 break;
 446         }
 447         return (buf);
 448 }
 449
 450 static void
 451 xdrrec_destroy(xdrs)
 452         XDR *xdrs;
 453 {
 454         RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
 455
 456         mem_free(rstrm->out_base, rstrm->sendsize);
 457         mem_free(rstrm->in_base, rstrm->recvsize);
 458         mem_free(rstrm, sizeof(RECSTREAM));
 459 }
 460
 461
 462 /*
 463  * Exported routines to manage xdr records
 464  */
 465
 466 /*
 467  * Before reading (deserializing from the stream, one should always call
 468  * this procedure to guarantee proper record alignment.
 469  */
 470 bool_t
 471 xdrrec_skiprecord(xdrs)
 472         XDR *xdrs;
 473 {
 474         RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
 475         enum xprt_stat xstat;
 476
 477         if (rstrm->nonblock) {
 478                 if (__xdrrec_getrec(xdrs, &xstat, FALSE)) {
 479                         rstrm->fbtbc = 0;
 480                         return TRUE;
 481                 }
 482                 if (rstrm->in_finger == rstrm->in_boundry &&
 483                     xstat == XPRT_MOREREQS) {
 484                         rstrm->fbtbc = 0;
 485                         return TRUE;
 486                 }
 487                 return FALSE;
 488         }
 489
 490         while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) {
 491                 if (! skip_input_bytes(rstrm, rstrm->fbtbc))
 492                         return (FALSE);
 493                 rstrm->fbtbc = 0;
 494                 if ((! rstrm->last_frag) && (! set_input_fragment(rstrm)))
 495                         return (FALSE);
 496         }
 497         rstrm->last_frag = FALSE;
 498         return (TRUE);
 499 }
 500
 501 /*
 502  * Look ahead function.
 503  * Returns TRUE iff there is no more input in the buffer
 504  * after consuming the rest of the current record.
 505  */
 506 bool_t
 507 xdrrec_eof(xdrs)
 508         XDR *xdrs;
 509 {
 510         RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
 511
 512         while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) {
 513                 if (! skip_input_bytes(rstrm, rstrm->fbtbc))
 514                         return (TRUE);
 515                 rstrm->fbtbc = 0;
 516                 if ((! rstrm->last_frag) && (! set_input_fragment(rstrm)))
 517                         return (TRUE);
 518         }
 519         if (rstrm->in_finger == rstrm->in_boundry)
 520                 return (TRUE);
 521         return (FALSE);
 522 }
 523
 524 /*
 525  * The client must tell the package when an end-of-record has occurred.
 526  * The second paraemters tells whether the record should be flushed to the
 527  * (output) tcp stream.  (This let's the package support batched or
 528  * pipelined procedure calls.)  TRUE => immmediate flush to tcp connection.
 529  */
 530 bool_t
 531 xdrrec_endofrecord(xdrs, sendnow)
 532         XDR *xdrs;
 533         bool_t sendnow;
 534 {
 535         RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
 536         u_long len;  /* fragment length */
 537
 538         if (sendnow || rstrm->frag_sent ||
 539                 ((u_long)rstrm->out_finger + sizeof(u_int32_t) >=
 540                 (u_long)rstrm->out_boundry)) {
 541                 rstrm->frag_sent = FALSE;
 542                 return (flush_out(rstrm, TRUE));
 543         }
 544         len = (u_long)(rstrm->out_finger) - (u_long)(rstrm->frag_header) -
 545            sizeof(u_int32_t);
 546         *(rstrm->frag_header) = htonl((u_int32_t)len | LAST_FRAG);
 547         rstrm->frag_header = (u_int32_t *)(void *)rstrm->out_finger;
 548         rstrm->out_finger += sizeof(u_int32_t);
 549         return (TRUE);
 550 }
 551
 552 /*
 553  * Fill the stream buffer with a record for a non-blocking connection.
 554  * Return true if a record is available in the buffer, false if not.
 555  */
 556 bool_t
 557 __xdrrec_getrec(xdrs, statp, expectdata)
 558         XDR *xdrs;
 559         enum xprt_stat *statp;
 560         bool_t expectdata;
 561 {
 562         RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
 563         ssize_t n;
 564         int fraglen;
 565
 566         if (!rstrm->in_haveheader) {
 567                 n = rstrm->readit(rstrm->tcp_handle, rstrm->in_hdrp,
 568                     (int)sizeof (rstrm->in_header) - rstrm->in_hdrlen);
 569                 if (n == 0) {
 570                         *statp = expectdata ? XPRT_DIED : XPRT_IDLE;
 571                         return FALSE;
 572                 }
 573                 if (n < 0) {
 574                         *statp = XPRT_DIED;
 575                         return FALSE;
 576                 }
 577                 rstrm->in_hdrp += n;
 578                 rstrm->in_hdrlen += n;
 579                 if (rstrm->in_hdrlen < sizeof (rstrm->in_header)) {
 580                         *statp = XPRT_MOREREQS;
 581                         return FALSE;
 582                 }
 583                 rstrm->in_header = ntohl(rstrm->in_header);
 584                 fraglen = (int)(rstrm->in_header & ~LAST_FRAG);
 585                 if (fraglen == 0 || fraglen > rstrm->in_maxrec ||
 586                     (rstrm->in_reclen + fraglen) > rstrm->in_maxrec) {
 587                         *statp = XPRT_DIED;
 588                         return FALSE;
 589                 }
 590                 rstrm->in_reclen += fraglen;
 591                 if (rstrm->in_reclen > rstrm->recvsize)
 592                         realloc_stream(rstrm, rstrm->in_reclen);
 593                 if (rstrm->in_header & LAST_FRAG) {
 594                         rstrm->in_header &= ~LAST_FRAG;
 595                         rstrm->last_frag = TRUE;
 596                 }
 597         }
 598
 599         n =  rstrm->readit(rstrm->tcp_handle,
 600             rstrm->in_base + rstrm->in_received,
 601             (rstrm->in_reclen - rstrm->in_received));
 602
 603         if (n < 0) {
 604                 *statp = XPRT_DIED;
 605                 return FALSE;
 606         }
 607
 608         if (n == 0) {
 609                 *statp = expectdata ? XPRT_DIED : XPRT_IDLE;
 610                 return FALSE;
 611         }
 612
 613         rstrm->in_received += n;
 614
 615         if (rstrm->in_received == rstrm->in_reclen) {
 616                 rstrm->in_haveheader = FALSE;
 617                 rstrm->in_hdrp = (char *)(void *)&rstrm->in_header;
 618                 rstrm->in_hdrlen = 0;
 619                 if (rstrm->last_frag) {
 620                         rstrm->fbtbc = rstrm->in_reclen;
 621                         rstrm->in_boundry = rstrm->in_base + rstrm->in_reclen;
 622                         rstrm->in_finger = rstrm->in_base;
 623                         rstrm->in_reclen = rstrm->in_received = 0;
 624                         *statp = XPRT_MOREREQS;
 625                         return TRUE;
 626                 }
 627         }
 628
 629         *statp = XPRT_MOREREQS;
 630         return FALSE;
 631 }
 632
 633 bool_t
 634 __xdrrec_setnonblock(xdrs, maxrec)
 635         XDR *xdrs;
 636         int maxrec;
 637 {
 638         RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
 639
 640         rstrm->nonblock = TRUE;
 641         if (maxrec == 0)
 642                 maxrec = rstrm->recvsize;
 643         rstrm->in_maxrec = maxrec;
 644         return TRUE;
 645 }
 646
 647 /*
 648  * Internal useful routines
 649  */
 650 static bool_t
 651 flush_out(rstrm, eor)
 652         RECSTREAM *rstrm;
 653         bool_t eor;
 654 {
 655         u_int32_t eormask = (eor == TRUE) ? LAST_FRAG : 0;
 656         u_int32_t len = (u_int32_t)((u_long)(rstrm->out_finger) -
 657                 (u_long)(rstrm->frag_header) - sizeof(u_int32_t));
 658
 659         *(rstrm->frag_header) = htonl(len | eormask);
 660         len = (u_int32_t)((u_long)(rstrm->out_finger) -
 661             (u_long)(rstrm->out_base));
 662         if ((*(rstrm->writeit))(rstrm->tcp_handle, rstrm->out_base, (int)len)
 663                 != (int)len)
 664                 return (FALSE);
 665         rstrm->frag_header = (u_int32_t *)(void *)rstrm->out_base;
 666         rstrm->out_finger = (char *)rstrm->out_base + sizeof(u_int32_t);
 667         return (TRUE);
 668 }
 669
 670 static bool_t  /* knows nothing about records!  Only about input buffers */
 671 fill_input_buf(rstrm)
 672         RECSTREAM *rstrm;
 673 {
 674         char *where;
 675         u_int32_t i;
 676         int len;
 677
 678         if (rstrm->nonblock)
 679                 return FALSE;
 680
 681         where = rstrm->in_base;
 682         i = (u_int32_t)((u_long)rstrm->in_boundry % BYTES_PER_XDR_UNIT);
 683         where += i;
 684         len = (u_int32_t)(rstrm->in_size - i);
 685         if ((len = (*(rstrm->readit))(rstrm->tcp_handle, where, len)) == -1)
 686                 return (FALSE);
 687         rstrm->in_finger = where;
 688         where += len;
 689         rstrm->in_boundry = where;
 690         return (TRUE);
 691 }
 692
 693 static bool_t  /* knows nothing about records!  Only about input buffers */
 694 get_input_bytes(rstrm, addr, len)
 695         RECSTREAM *rstrm;
 696         char *addr;
 697         int len;
 698 {
 699         size_t current;
 700
 701         if (rstrm->nonblock) {
 702                 if (len > (int)(rstrm->in_boundry - rstrm->in_finger))
 703                         return FALSE;
 704                 memcpy(addr, rstrm->in_finger, (size_t)len);
 705                 rstrm->in_finger += len;
 706                 return TRUE;
 707         }
 708
 709         while (len > 0) {
 710                 current = (size_t)((long)rstrm->in_boundry -
 711                     (long)rstrm->in_finger);
 712                 if (current == 0) {
 713                         if (! fill_input_buf(rstrm))
 714                                 return (FALSE);
 715                         continue;
 716                 }
 717                 current = (len < current) ? len : current;
 718                 memmove(addr, rstrm->in_finger, current);
 719                 rstrm->in_finger += current;
 720                 addr += current;
 721                 len -= current;
 722         }
 723         return (TRUE);
 724 }
 725
 726 static bool_t  /* next two bytes of the input stream are treated as a header */
 727 set_input_fragment(rstrm)
 728         RECSTREAM *rstrm;
 729 {
 730         u_int32_t header;
 731
 732         if (rstrm->nonblock)
 733                 return FALSE;
 734         if (! get_input_bytes(rstrm, (char *)(void *)&header, sizeof(header)))
 735                 return (FALSE);
 736         header = ntohl(header);
 737         rstrm->last_frag = ((header & LAST_FRAG) == 0) ? FALSE : TRUE;
 738         /*
 739          * Sanity check. Try not to accept wildly incorrect
 740          * record sizes. Unfortunately, the only record size
 741          * we can positively identify as being 'wildly incorrect'
 742          * is zero. Ridiculously large record sizes may look wrong,
 743          * but we don't have any way to be certain that they aren't
 744          * what the client actually intended to send us.
 745          */
 746         if (header == 0)
 747                 return(FALSE);
 748         rstrm->fbtbc = header & (~LAST_FRAG);
 749         return (TRUE);
 750 }
 751
 752 static bool_t  /* consumes input bytes; knows nothing about records! */
 753 skip_input_bytes(rstrm, cnt)
 754         RECSTREAM *rstrm;
 755         long cnt;
 756 {
 757         u_int32_t current;
 758
 759         while (cnt > 0) {
 760                 current = (size_t)((long)rstrm->in_boundry -
 761                     (long)rstrm->in_finger);
 762                 if (current == 0) {
 763                         if (! fill_input_buf(rstrm))
 764                                 return (FALSE);
 765                         continue;
 766                 }
 767                 current = (u_int32_t)((cnt < current) ? cnt : current);
 768                 rstrm->in_finger += current;
 769                 cnt -= current;
 770         }
 771         return (TRUE);
 772 }
 773
 774 static u_int
 775 fix_buf_size(s)
 776         u_int s;
 777 {
 778
 779         if (s < 100)
 780                 s = 4000;
 781         return (RNDUP(s));
 782 }
 783
 784 /*
 785  * Reallocate the input buffer for a non-block stream.
 786  */
 787 static bool_t
 788 realloc_stream(rstrm, size)
 789         RECSTREAM *rstrm;
 790         int size;
 791 {
 792         long diff;
 793         char *buf;
 794
 795         if (size > rstrm->recvsize) {
 796                 buf = realloc(rstrm->in_base, (size_t)size);
 797                 if (buf == NULL)
 798                         return FALSE;
 799                 diff = buf - rstrm->in_base;
 800                 rstrm->in_finger += diff;
 801                 rstrm->in_base = buf;
 802                 rstrm->in_boundry = buf + size;
 803                 rstrm->recvsize = size;
 804                 rstrm->in_size = size;
 805         }
 806
 807         return TRUE;
 808 }