4.3BSD - /usr/src/new/sunrpc/xdr_rec.c

   1: /*
   2:  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
   3:  * unrestricted use provided that this legend is included on all tape
   4:  * media and as a part of the software program in whole or part.  Users
   5:  * may copy or modify Sun RPC without charge, but are not authorized
   6:  * to license or distribute it to anyone else except as part of a product or
   7:  * program developed by the user.
   8:  *
   9:  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
  10:  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
  11:  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
  12:  *
  13:  * Sun RPC is provided with no support and without any obligation on the
  14:  * part of Sun Microsystems, Inc. to assist in its use, correction,
  15:  * modification or enhancement.
  16:  *
  17:  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
  18:  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
  19:  * OR ANY PART THEREOF.
  20:  *
  21:  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
  22:  * or profits or other special, indirect and consequential damages, even if
  23:  * Sun has been advised of the possibility of such damages.
  24:  *
  25:  * Sun Microsystems, Inc.
  26:  * 2550 Garcia Avenue
  27:  * Mountain View, California  94043
  28:  */
  29: #ifndef lint
  30: static char sccsid[] = "@(#)xdr_rec.c 1.5 85/03/14 Copyr 1984 Sun Micro";
  31: #endif
  32: 
  33: /*
  34:  * xdr_rec.c, Implements TCP/IP based XDR streams with a "record marking"
  35:  * layer above tcp (for rpc's use).
  36:  *
  37:  * Copyright (C) 1984, Sun Microsystems, Inc.
  38:  *
  39:  * These routines interface XDRSTREAMS to a tcp/ip connection.
  40:  * There is a record marking layer between the xdr stream
  41:  * and the tcp transport level.  A record is composed on one or more
  42:  * record fragments.  A record fragment is a thirty-two bit header followed
  43:  * by n bytes of data, where n is contained in the header.  The header
  44:  * is represented as a htonl(u_long).  Thegh order bit encodes
  45:  * whether or not the fragment is the last fragment of the record
  46:  * (1 => fragment is last, 0 => more fragments to follow.
  47:  * The other 31 bits encode the byte length of the fragment.
  48:  */
  49: 
  50: #include <stdio.h>
  51: #include "types.h"
  52: #include "xdr.h"
  53: #include <sys/time.h>
  54: #include <netinet/in.h>
  55: 
  56: char *mem_alloc();
  57: 
  58: static u_int    fix_buf_size();
  59: 
  60: static bool_t   xdrrec_getlong();
  61: static bool_t   xdrrec_putlong();
  62: static bool_t   xdrrec_getbytes();
  63: static bool_t   xdrrec_putbytes();
  64: static u_int    xdrrec_getpos();
  65: static bool_t   xdrrec_setpos();
  66: static long *   xdrrec_inline();
  67: static void xdrrec_destroy();
  68: 
  69: static struct  xdr_ops xdrrec_ops = {
  70:     xdrrec_getlong,
  71:     xdrrec_putlong,
  72:     xdrrec_getbytes,
  73:     xdrrec_putbytes,
  74:     xdrrec_getpos,
  75:     xdrrec_setpos,
  76:     xdrrec_inline,
  77:     xdrrec_destroy
  78: };
  79: 
  80: /*
  81:  * A record is composed of one or more record fragments.
  82:  * A record fragment is a two-byte header followed by zero to
  83:  * 2**32-1 bytes.  The header is treated as a long unsigned and is
  84:  * encode/decoded to the network via htonl/ntohl.  The low order 31 bits
  85:  * are a byte count of the fragment.  The highest order bit is a boolean:
  86:  * 1 => this fragment is the last fragment of the record,
  87:  * 0 => this fragment is followed by more fragment(s).
  88:  *
  89:  * The fragment/record machinery is not general;  it is constructed to
  90:  * meet the needs of xdr and rpc based on tcp.
  91:  */
  92: 
  93: #define LAST_FRAG ((u_long)(1 << 31))
  94: 
  95: typedef struct rec_strm {
  96:     caddr_t tcp_handle;
  97:     /*
  98: 	 * out-goung bits
  99: 	 */
 100:     int (*writeit)();
 101:     caddr_t out_base;   /* output buffer (points to frag header) */
 102:     caddr_t out_finger; /* next output position */
 103:     caddr_t out_boundry;    /* data cannot up to this address */
 104:     u_long *frag_header;    /* beginning of curren fragment */
 105:     bool_t frag_sent;   /* true if buffer sent in middle of record */
 106:     /*
 107: 	 * in-coming bits
 108: 	 */
 109:     int (*readit)();
 110:     u_long in_size; /* fixed size of the input buffer */
 111:     caddr_t in_base;
 112:     caddr_t in_finger;  /* location of next byte to be had */
 113:     caddr_t in_boundry; /* can read up to this location */
 114:     long fbtbc;     /* fragment bytes to be consumed */
 115:     bool_t last_frag;
 116:     u_int sendsize;
 117:     u_int recvsize;
 118: } RECSTREAM;
 119: 
 120: 
 121: /*
 122:  * Create an xdr handle for xdrrec
 123:  * xdrrec_create fills in xdrs.  Sendsize and recvsize are
 124:  * send and recv buffer sizes (0 => use default).
 125:  * tcp_handle is an opaque handle that is passed as the first parameter to
 126:  * the procedures readit and writeit.  Readit and writeit are read and
 127:  * write respectively.   They are like the system
 128:  * calls expect that they take an opaque handle rather than an fd.
 129:  */
 130: void
 131: xdrrec_create(xdrs, sendsize, recvsize, tcp_handle, readit, writeit)
 132:     register XDR *xdrs;
 133:     u_int sendsize;
 134:     u_int recvsize;
 135:     caddr_t tcp_handle;
 136:     int (*readit)();  /* like read, but pass it a tcp_handle, not sock */
 137:     int (*writeit)();  /* like write, but pass it a tcp_handle, not sock */
 138: {
 139:     register RECSTREAM *rstrm =
 140:         (RECSTREAM *)mem_alloc(sizeof(RECSTREAM));
 141: 
 142:     if (rstrm == NULL) {
 143:         fprintf(stderr, "xdrrec_create: out of memory\n");
 144:         /*
 145: 		 *  This is bad.  Should rework xdrrec_create to
 146: 		 *  return a handle, and in this case return NULL
 147: 		 */
 148:         return;
 149:     }
 150:     xdrs->x_ops = &xdrrec_ops;
 151:     xdrs->x_private = (caddr_t)rstrm;
 152:     rstrm->tcp_handle = tcp_handle;
 153:     rstrm->readit = readit;
 154:     rstrm->writeit = writeit;
 155:     sendsize = fix_buf_size(sendsize);
 156:     if ((rstrm->out_base = rstrm->out_finger = rstrm->out_boundry =
 157:         mem_alloc(sendsize)) == NULL) {
 158:         fprintf(stderr, "xdrrec_create: out of memory\n");
 159:         return;
 160:     }
 161:     rstrm->frag_header = (u_long *)rstrm->out_base;
 162:     rstrm->out_finger += sizeof(u_long);
 163:     rstrm->out_boundry += sendsize;
 164:     rstrm->frag_sent = FALSE;
 165:     rstrm->in_size = recvsize = fix_buf_size(recvsize);
 166:     if ((rstrm->in_base = rstrm->in_boundry=mem_alloc(recvsize)) == NULL) {
 167:         fprintf(stderr, "xdrrec_create: out of memory\n");
 168:         return;
 169:     }
 170:     rstrm->in_finger = (rstrm->in_boundry += recvsize);
 171:     rstrm->fbtbc = 0;
 172:     rstrm->last_frag = TRUE;
 173:     rstrm->sendsize = sendsize;
 174:     rstrm->recvsize = recvsize;
 175: }
 176: 
 177: 
 178: /*
 179:  * The reoutines defined below are the xdr ops which will go into the
 180:  * xdr handle filled in by xdrrec_create.
 181:  */
 182: 
 183: static bool_t
 184: xdrrec_getlong(xdrs, lp)
 185:     XDR *xdrs;
 186:     long *lp;
 187: {
 188:     register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
 189:     register long *buflp = (long *)(rstrm->in_finger);
 190:     long mylong;
 191: 
 192:     /* first try the inline, fast case */
 193:     if ((rstrm->fbtbc >= sizeof(long)) &&
 194:         (((int)rstrm->in_boundry - (int)buflp) >= sizeof(long))) {
 195:         *lp = ntohl(*buflp);
 196:         rstrm->fbtbc -= sizeof(long);
 197:         rstrm->in_finger += sizeof(long);
 198:     } else {
 199:         if (! xdrrec_getbytes(xdrs, (caddr_t)&mylong, sizeof(long)))
 200:             return (FALSE);
 201:         *lp = ntohl(mylong);
 202:     }
 203:     return (TRUE);
 204: }
 205: 
 206: static bool_t
 207: xdrrec_putlong(xdrs, lp)
 208:     XDR *xdrs;
 209:     long *lp;
 210: {
 211:     register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
 212:     register long *dest_lp = ((long *)(rstrm->out_finger));
 213: 
 214:     if ((rstrm->out_finger += sizeof(long)) > rstrm->out_boundry) {
 215:         /*
 216: 		 * this case should almost never happen so the code is
 217: 		 * inefficient
 218: 		 */
 219:         rstrm->out_finger -= sizeof(long);
 220:         rstrm->frag_sent = TRUE;
 221:         if (! flush_out(rstrm, FALSE))
 222:             return (FALSE);
 223:         dest_lp = ((long *)(rstrm->out_finger));
 224:         rstrm->out_finger += sizeof(long);
 225:     }
 226:     *dest_lp = htonl(*lp);
 227:     return (TRUE);
 228: }
 229: 
 230: static bool_t  /* must manage buffers, fragments, and records */
 231: xdrrec_getbytes(xdrs, addr, len)
 232:     XDR *xdrs;
 233:     register caddr_t addr;
 234:     register u_int len;
 235: {
 236:     register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
 237:     register int current;
 238: 
 239:     while (len > 0) {
 240:         current = rstrm->fbtbc;
 241:         if (current == 0) {
 242:             if (rstrm->last_frag)
 243:                 return (FALSE);
 244:             if (! set_input_fragment(rstrm))
 245:                 return (FALSE);
 246:             continue;
 247:         }
 248:         current = (len < current) ? len : current;
 249:         if (! get_input_bytes(rstrm, addr, current))
 250:             return (FALSE);
 251:         addr += current;
 252:         rstrm->fbtbc -= current;
 253:         len -= current;
 254:     }
 255:     return (TRUE);
 256: }
 257: 
 258: static bool_t
 259: xdrrec_putbytes(xdrs, addr, len)
 260:     XDR *xdrs;
 261:     register caddr_t addr;
 262:     register u_int len;
 263: {
 264:     register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
 265:     register int current;
 266: 
 267:     while (len > 0) {
 268:         current = (u_int)rstrm->out_boundry - (u_int)rstrm->out_finger;
 269:         current = (len < current) ? len : current;
 270:         bcopy(addr, rstrm->out_finger, current);
 271:         rstrm->out_finger += current;
 272:         addr += current;
 273:         len -= current;
 274:         if (rstrm->out_finger == rstrm->out_boundry) {
 275:             rstrm->frag_sent = TRUE;
 276:             if (! flush_out(rstrm, FALSE))
 277:                 return (FALSE);
 278:         }
 279:     }
 280:     return (TRUE);
 281: }
 282: 
 283: static u_int
 284: xdrrec_getpos(xdrs)
 285:     register XDR *xdrs;
 286: {
 287:     register RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
 288:     register u_int pos;
 289: 
 290:     pos = lseek((int)rstrm->tcp_handle, 0, 1);
 291:     if ((int)pos != -1)
 292:         switch (xdrs->x_op) {
 293: 
 294:         case XDR_ENCODE:
 295:             pos += rstrm->out_finger - rstrm->out_base;
 296:             break;
 297: 
 298:         case XDR_DECODE:
 299:             pos -= rstrm->in_boundry - rstrm->in_finger;
 300:             break;
 301: 
 302:         default:
 303:             pos = (u_int) -1;
 304:             break;
 305:         }
 306:     return (pos);
 307: }
 308: 
 309: static bool_t
 310: xdrrec_setpos(xdrs, pos)
 311:     register XDR *xdrs;
 312:     u_int pos;
 313: {
 314:     register RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
 315:     u_int currpos = xdrrec_getpos(xdrs);
 316:     int delta = currpos - pos;
 317:     caddr_t newpos;
 318: 
 319:     if ((int)currpos != -1)
 320:         switch (xdrs->x_op) {
 321: 
 322:         case XDR_ENCODE:
 323:             newpos = rstrm->out_finger - delta;
 324:             if ((newpos > (caddr_t)(rstrm->frag_header)) &&
 325:                 (newpos < rstrm->out_boundry)) {
 326:                 rstrm->out_finger = newpos;
 327:                 return (TRUE);
 328:             }
 329:             break;
 330: 
 331:         case XDR_DECODE:
 332:             newpos = rstrm->in_finger - delta;
 333:             if ((delta < (int)(rstrm->fbtbc)) &&
 334:                 (newpos <= rstrm->in_boundry) &&
 335:                 (newpos >= rstrm->in_base)) {
 336:                 rstrm->in_finger = newpos;
 337:                 rstrm->fbtbc -= delta;
 338:                 return (TRUE);
 339:             }
 340:             break;
 341:         }
 342:     return (FALSE);
 343: }
 344: 
 345: static long *
 346: xdrrec_inline(xdrs, len)
 347:     register XDR *xdrs;
 348:     int len;
 349: {
 350:     register RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
 351:     long * buf = NULL;
 352: 
 353:     switch (xdrs->x_op) {
 354: 
 355:     case XDR_ENCODE:
 356:         if ((rstrm->out_finger + len) <= rstrm->out_boundry) {
 357:             buf = (long *) rstrm->out_finger;
 358:             rstrm->out_finger += len;
 359:         }
 360:         break;
 361: 
 362:     case XDR_DECODE:
 363:         if ((len <= rstrm->fbtbc) &&
 364:             ((rstrm->in_finger + len) <= rstrm->in_boundry)) {
 365:             buf = (long *) rstrm->in_finger;
 366:             rstrm->fbtbc -= len;
 367:             rstrm->in_finger += len;
 368:         }
 369:         break;
 370:     }
 371:     return (buf);
 372: }
 373: 
 374: static void
 375: xdrrec_destroy(xdrs)
 376:     register XDR *xdrs;
 377: {
 378:     register RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private;
 379: 
 380:     mem_free(rstrm->out_base, rstrm->sendsize);
 381:     mem_free(rstrm->in_base, rstrm->recvsize);
 382:     mem_free((caddr_t)rstrm, sizeof(RECSTREAM));
 383: }
 384: 
 385: 
 386: /*
 387:  * Exported routines to manage xdr records
 388:  */
 389: 
 390: /*
 391:  * Before reading (deserializing from the stream, one should always call
 392:  * this procedure to guarantee proper record alignment.
 393:  */
 394: bool_t
 395: xdrrec_skiprecord(xdrs)
 396:     XDR *xdrs;
 397: {
 398:     register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
 399: 
 400:     while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) {
 401:         if (! skip_input_bytes(rstrm, rstrm->fbtbc))
 402:             return (FALSE);
 403:         rstrm->fbtbc = 0;
 404:         if ((! rstrm->last_frag) && (! set_input_fragment(rstrm)))
 405:             return (FALSE);
 406:     }
 407:     rstrm->last_frag = FALSE;
 408:     return (TRUE);
 409: }
 410: 
 411: /*
 412:  * Look ahead fuction.
 413:  * Returns TRUE iff there is no more input in the buffer
 414:  * after consuming the rest of the current record.
 415:  */
 416: bool_t
 417: xdrrec_eof(xdrs)
 418:     XDR *xdrs;
 419: {
 420:     register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
 421: 
 422:     while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) {
 423:         if (! skip_input_bytes(rstrm, rstrm->fbtbc))
 424:             return (TRUE);
 425:         rstrm->fbtbc = 0;
 426:         if ((! rstrm->last_frag) && (! set_input_fragment(rstrm)))
 427:             return (TRUE);
 428:     }
 429:     if (rstrm->in_finger == rstrm->in_boundry)
 430:         return (TRUE);
 431:     return (FALSE);
 432: }
 433: 
 434: /*
 435:  * The client must tell the package when an end-of-record has occurred.
 436:  * The second paraemters tells whether the record should be flushed to the
 437:  * (output) tcp stream.  (This let's the package support batched or
 438:  * pipelined procedure calls.)  TRUE => immmediate flush to tcp connection.
 439:  */
 440: bool_t
 441: xdrrec_endofrecord(xdrs, sendnow)
 442:     XDR *xdrs;
 443:     bool_t sendnow;
 444: {
 445:     register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private);
 446:     register u_long len;  /* fragment length */
 447: 
 448:     if (sendnow || rstrm->frag_sent ||
 449:         ((u_long)rstrm->out_finger + sizeof(u_long) >=
 450:         (u_long)rstrm->out_boundry)) {
 451:         rstrm->frag_sent = FALSE;
 452:         return (flush_out(rstrm, TRUE));
 453:     }
 454:     len = (u_long)(rstrm->out_finger) - (u_long)(rstrm->frag_header) -
 455:        sizeof(u_long);
 456:     *(rstrm->frag_header) = htonl(len | LAST_FRAG);
 457:     rstrm->frag_header = (u_long *)rstrm->out_finger;
 458:     rstrm->out_finger += sizeof(u_long);
 459:     return (TRUE);
 460: }
 461: 
 462: 
 463: /*
 464:  * Internal useful routines
 465:  */
 466: static bool_t
 467: flush_out(rstrm, eor)
 468:     register RECSTREAM *rstrm;
 469:     bool_t eor;
 470: {
 471:     register u_long eormask = (eor == TRUE) ? LAST_FRAG : 0;
 472:     register u_long len = (u_long)(rstrm->out_finger) -
 473:         (u_long)(rstrm->frag_header) - sizeof(u_long);
 474: 
 475:     *(rstrm->frag_header) = htonl(len | eormask);
 476:     len = (u_long)(rstrm->out_finger) - (u_long)(rstrm->out_base);
 477:     if ((*(rstrm->writeit))(rstrm->tcp_handle, rstrm->out_base, (int)len)
 478:         != (int)len)
 479:         return (FALSE);
 480:     rstrm->frag_header = (u_long *)rstrm->out_base;
 481:     rstrm->out_finger = (caddr_t)rstrm->out_base + sizeof(u_long);
 482:     return (TRUE);
 483: }
 484: 
 485: static bool_t  /* knows nothing about records!  Only about input buffers */
 486: fill_input_buf(rstrm)
 487:     register RECSTREAM *rstrm;
 488: {
 489:     register caddr_t where = rstrm->in_base;
 490:     register int len = rstrm->in_size;
 491: 
 492:     if (((int)rstrm->in_boundry % 2) != 0) {
 493:         /* keep stream odd bytes aligned with memory odd bytes */
 494:         where++;
 495:         len--;
 496:     }
 497:     if ((len = (*(rstrm->readit))(rstrm->tcp_handle, where, len)) == -1)
 498:         return (FALSE);
 499:     rstrm->in_finger = where;
 500:     where += len;
 501:     rstrm->in_boundry = where;
 502:     return (TRUE);
 503: }
 504: 
 505: static bool_t  /* knows nothing about records!  Only about input buffers */
 506: get_input_bytes(rstrm, addr, len)
 507:     register RECSTREAM *rstrm;
 508:     register caddr_t addr;
 509:     register int len;
 510: {
 511:     register int current;
 512: 
 513:     while (len > 0) {
 514:         current = (int)rstrm->in_boundry - (int)rstrm->in_finger;
 515:         if (current == 0) {
 516:             if (! fill_input_buf(rstrm))
 517:                 return (FALSE);
 518:             continue;
 519:         }
 520:         current = (len < current) ? len : current;
 521:         bcopy(rstrm->in_finger, addr, current);
 522:         rstrm->in_finger += current;
 523:         addr += current;
 524:         len -= current;
 525:     }
 526:     return (TRUE);
 527: }
 528: 
 529: static bool_t  /* next two bytes of the input stream are treated as a header */
 530: set_input_fragment(rstrm)
 531:     register RECSTREAM *rstrm;
 532: {
 533:     u_long header;
 534: 
 535:     if (! get_input_bytes(rstrm, (caddr_t)&header, sizeof(header)))
 536:         return (FALSE);
 537:     header = ntohl(header);
 538:     rstrm->last_frag = ((header & LAST_FRAG) == 0) ? FALSE : TRUE;
 539:     rstrm->fbtbc = header & (~LAST_FRAG);
 540:     return (TRUE);
 541: }
 542: 
 543: static bool_t  /* consumes input bytes; knows nothing about records! */
 544: skip_input_bytes(rstrm, cnt)
 545:     register RECSTREAM *rstrm;
 546:     int cnt;
 547: {
 548:     register int current;
 549: 
 550:     while (cnt > 0) {
 551:         current = (int)rstrm->in_boundry - (int)rstrm->in_finger;
 552:         if (current == 0) {
 553:             if (! fill_input_buf(rstrm))
 554:                 return (FALSE);
 555:             continue;
 556:         }
 557:         current = (cnt < current) ? cnt : current;
 558:         rstrm->in_finger += current;
 559:         cnt -= current;
 560:     }
 561:     return (TRUE);
 562: }
 563: 
 564: static u_int
 565: fix_buf_size(s)
 566:     register u_int s;
 567: {
 568: 
 569:     if (s < 100)
 570:         return (3998);
 571:     for (; (s % 4) != 2; --s);
 572:     return (s);
 573: }

Defined functions

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Defined struct's

Defined typedef's

Defined macros