xdr_rec.c revision 1.1
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 #if defined(LIBC_SCCS) && !defined(lint) 30 /*static char *sccsid = "from: @(#)xdr_rec.c 1.21 87/08/11 Copyr 1984 Sun Micro";*/ 31 /*static char *sccsid = "from: @(#)xdr_rec.c 2.2 88/08/01 4.0 RPCSRC";*/ 32 static char *rcsid = "$Id: xdr_rec.c,v 1.1 1993/10/07 07:30:27 cgd Exp $"; 33 #endif 34 35 /* 36 * xdr_rec.c, Implements TCP/IP based XDR streams with a "record marking" 37 * layer above tcp (for rpc's use). 38 * 39 * Copyright (C) 1984, Sun Microsystems, Inc. 40 * 41 * These routines interface XDRSTREAMS to a tcp/ip connection. 42 * There is a record marking layer between the xdr stream 43 * and the tcp transport level. A record is composed on one or more 44 * record fragments. A record fragment is a thirty-two bit header followed 45 * by n bytes of data, where n is contained in the header. The header 46 * is represented as a htonl(u_long). Thegh order bit encodes 47 * whether or not the fragment is the last fragment of the record 48 * (1 => fragment is last, 0 => more fragments to follow. 49 * The other 31 bits encode the byte length of the fragment. 50 */ 51 52 #include <stdio.h> 53 #include <stdlib.h> 54 #include <rpc/types.h> 55 #include <rpc/xdr.h> 56 #include <netinet/in.h> 57 58 extern long lseek(); 59 60 static u_int fix_buf_size(); 61 static bool_t flush_out(); 62 static bool_t get_input_bytes(); 63 static bool_t set_input_fragment(); 64 static bool_t skip_input_bytes(); 65 66 static bool_t xdrrec_getlong(); 67 static bool_t xdrrec_putlong(); 68 static bool_t xdrrec_getbytes(); 69 static bool_t xdrrec_putbytes(); 70 static u_int xdrrec_getpos(); 71 static bool_t xdrrec_setpos(); 72 static long * xdrrec_inline(); 73 static void xdrrec_destroy(); 74 75 static struct xdr_ops xdrrec_ops = { 76 xdrrec_getlong, 77 xdrrec_putlong, 78 xdrrec_getbytes, 79 xdrrec_putbytes, 80 xdrrec_getpos, 81 xdrrec_setpos, 82 xdrrec_inline, 83 xdrrec_destroy 84 }; 85 86 /* 87 * A record is composed of one or more record fragments. 88 * A record fragment is a two-byte header followed by zero to 89 * 2**32-1 bytes. The header is treated as a long unsigned and is 90 * encode/decoded to the network via htonl/ntohl. The low order 31 bits 91 * are a byte count of the fragment. The highest order bit is a boolean: 92 * 1 => this fragment is the last fragment of the record, 93 * 0 => this fragment is followed by more fragment(s). 94 * 95 * The fragment/record machinery is not general; it is constructed to 96 * meet the needs of xdr and rpc based on tcp. 97 */ 98 99 #define LAST_FRAG ((u_long)(1 << 31)) 100 101 typedef struct rec_strm { 102 caddr_t tcp_handle; 103 caddr_t the_buffer; 104 /* 105 * out-goung bits 106 */ 107 int (*writeit)(); 108 caddr_t out_base; /* output buffer (points to frag header) */ 109 caddr_t out_finger; /* next output position */ 110 caddr_t out_boundry; /* data cannot up to this address */ 111 u_long *frag_header; /* beginning of curren fragment */ 112 bool_t frag_sent; /* true if buffer sent in middle of record */ 113 /* 114 * in-coming bits 115 */ 116 int (*readit)(); 117 u_long in_size; /* fixed size of the input buffer */ 118 caddr_t in_base; 119 caddr_t in_finger; /* location of next byte to be had */ 120 caddr_t in_boundry; /* can read up to this location */ 121 long fbtbc; /* fragment bytes to be consumed */ 122 bool_t last_frag; 123 u_int sendsize; 124 u_int recvsize; 125 } RECSTREAM; 126 127 128 /* 129 * Create an xdr handle for xdrrec 130 * xdrrec_create fills in xdrs. Sendsize and recvsize are 131 * send and recv buffer sizes (0 => use default). 132 * tcp_handle is an opaque handle that is passed as the first parameter to 133 * the procedures readit and writeit. Readit and writeit are read and 134 * write respectively. They are like the system 135 * calls expect that they take an opaque handle rather than an fd. 136 */ 137 void 138 xdrrec_create(xdrs, sendsize, recvsize, tcp_handle, readit, writeit) 139 register XDR *xdrs; 140 register u_int sendsize; 141 register u_int recvsize; 142 caddr_t tcp_handle; 143 int (*readit)(); /* like read, but pass it a tcp_handle, not sock */ 144 int (*writeit)(); /* like write, but pass it a tcp_handle, not sock */ 145 { 146 register RECSTREAM *rstrm = 147 (RECSTREAM *)mem_alloc(sizeof(RECSTREAM)); 148 149 if (rstrm == NULL) { 150 (void)fprintf(stderr, "xdrrec_create: out of memory\n"); 151 /* 152 * This is bad. Should rework xdrrec_create to 153 * return a handle, and in this case return NULL 154 */ 155 return; 156 } 157 /* 158 * adjust sizes and allocate buffer quad byte aligned 159 */ 160 rstrm->sendsize = sendsize = fix_buf_size(sendsize); 161 rstrm->recvsize = recvsize = fix_buf_size(recvsize); 162 rstrm->the_buffer = mem_alloc(sendsize + recvsize + BYTES_PER_XDR_UNIT); 163 if (rstrm->the_buffer == NULL) { 164 (void)fprintf(stderr, "xdrrec_create: out of memory\n"); 165 return; 166 } 167 for (rstrm->out_base = rstrm->the_buffer; 168 (u_int)rstrm->out_base % BYTES_PER_XDR_UNIT != 0; 169 rstrm->out_base++); 170 rstrm->in_base = rstrm->out_base + sendsize; 171 /* 172 * now the rest ... 173 */ 174 xdrs->x_ops = &xdrrec_ops; 175 xdrs->x_private = (caddr_t)rstrm; 176 rstrm->tcp_handle = tcp_handle; 177 rstrm->readit = readit; 178 rstrm->writeit = writeit; 179 rstrm->out_finger = rstrm->out_boundry = rstrm->out_base; 180 rstrm->frag_header = (u_long *)rstrm->out_base; 181 rstrm->out_finger += sizeof(u_long); 182 rstrm->out_boundry += sendsize; 183 rstrm->frag_sent = FALSE; 184 rstrm->in_size = recvsize; 185 rstrm->in_boundry = rstrm->in_base; 186 rstrm->in_finger = (rstrm->in_boundry += recvsize); 187 rstrm->fbtbc = 0; 188 rstrm->last_frag = TRUE; 189 } 190 191 192 /* 193 * The reoutines defined below are the xdr ops which will go into the 194 * xdr handle filled in by xdrrec_create. 195 */ 196 197 static bool_t 198 xdrrec_getlong(xdrs, lp) 199 XDR *xdrs; 200 long *lp; 201 { 202 register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 203 register long *buflp = (long *)(rstrm->in_finger); 204 long mylong; 205 206 /* first try the inline, fast case */ 207 if ((rstrm->fbtbc >= sizeof(long)) && 208 (((int)rstrm->in_boundry - (int)buflp) >= sizeof(long))) { 209 *lp = (long)ntohl((u_long)(*buflp)); 210 rstrm->fbtbc -= sizeof(long); 211 rstrm->in_finger += sizeof(long); 212 } else { 213 if (! xdrrec_getbytes(xdrs, (caddr_t)&mylong, sizeof(long))) 214 return (FALSE); 215 *lp = (long)ntohl((u_long)mylong); 216 } 217 return (TRUE); 218 } 219 220 static bool_t 221 xdrrec_putlong(xdrs, lp) 222 XDR *xdrs; 223 long *lp; 224 { 225 register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 226 register long *dest_lp = ((long *)(rstrm->out_finger)); 227 228 if ((rstrm->out_finger += sizeof(long)) > rstrm->out_boundry) { 229 /* 230 * this case should almost never happen so the code is 231 * inefficient 232 */ 233 rstrm->out_finger -= sizeof(long); 234 rstrm->frag_sent = TRUE; 235 if (! flush_out(rstrm, FALSE)) 236 return (FALSE); 237 dest_lp = ((long *)(rstrm->out_finger)); 238 rstrm->out_finger += sizeof(long); 239 } 240 *dest_lp = (long)htonl((u_long)(*lp)); 241 return (TRUE); 242 } 243 244 static bool_t /* must manage buffers, fragments, and records */ 245 xdrrec_getbytes(xdrs, addr, len) 246 XDR *xdrs; 247 register caddr_t addr; 248 register u_int len; 249 { 250 register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 251 register int current; 252 253 while (len > 0) { 254 current = rstrm->fbtbc; 255 if (current == 0) { 256 if (rstrm->last_frag) 257 return (FALSE); 258 if (! set_input_fragment(rstrm)) 259 return (FALSE); 260 continue; 261 } 262 current = (len < current) ? len : current; 263 if (! get_input_bytes(rstrm, addr, current)) 264 return (FALSE); 265 addr += current; 266 rstrm->fbtbc -= current; 267 len -= current; 268 } 269 return (TRUE); 270 } 271 272 static bool_t 273 xdrrec_putbytes(xdrs, addr, len) 274 XDR *xdrs; 275 register caddr_t addr; 276 register u_int len; 277 { 278 register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 279 register int current; 280 281 while (len > 0) { 282 current = (u_int)rstrm->out_boundry - (u_int)rstrm->out_finger; 283 current = (len < current) ? len : current; 284 bcopy(addr, rstrm->out_finger, current); 285 rstrm->out_finger += current; 286 addr += current; 287 len -= current; 288 if (rstrm->out_finger == rstrm->out_boundry) { 289 rstrm->frag_sent = TRUE; 290 if (! flush_out(rstrm, FALSE)) 291 return (FALSE); 292 } 293 } 294 return (TRUE); 295 } 296 297 static u_int 298 xdrrec_getpos(xdrs) 299 register XDR *xdrs; 300 { 301 register RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; 302 register long pos; 303 304 pos = lseek((int)rstrm->tcp_handle, (long) 0, 1); 305 if (pos != -1) 306 switch (xdrs->x_op) { 307 308 case XDR_ENCODE: 309 pos += rstrm->out_finger - rstrm->out_base; 310 break; 311 312 case XDR_DECODE: 313 pos -= rstrm->in_boundry - rstrm->in_finger; 314 break; 315 316 default: 317 pos = (u_int) -1; 318 break; 319 } 320 return ((u_int) pos); 321 } 322 323 static bool_t 324 xdrrec_setpos(xdrs, pos) 325 register XDR *xdrs; 326 u_int pos; 327 { 328 register RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; 329 u_int currpos = xdrrec_getpos(xdrs); 330 int delta = currpos - pos; 331 caddr_t newpos; 332 333 if ((int)currpos != -1) 334 switch (xdrs->x_op) { 335 336 case XDR_ENCODE: 337 newpos = rstrm->out_finger - delta; 338 if ((newpos > (caddr_t)(rstrm->frag_header)) && 339 (newpos < rstrm->out_boundry)) { 340 rstrm->out_finger = newpos; 341 return (TRUE); 342 } 343 break; 344 345 case XDR_DECODE: 346 newpos = rstrm->in_finger - delta; 347 if ((delta < (int)(rstrm->fbtbc)) && 348 (newpos <= rstrm->in_boundry) && 349 (newpos >= rstrm->in_base)) { 350 rstrm->in_finger = newpos; 351 rstrm->fbtbc -= delta; 352 return (TRUE); 353 } 354 break; 355 } 356 return (FALSE); 357 } 358 359 static long * 360 xdrrec_inline(xdrs, len) 361 register XDR *xdrs; 362 int len; 363 { 364 register RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; 365 long * buf = NULL; 366 367 switch (xdrs->x_op) { 368 369 case XDR_ENCODE: 370 if ((rstrm->out_finger + len) <= rstrm->out_boundry) { 371 buf = (long *) rstrm->out_finger; 372 rstrm->out_finger += len; 373 } 374 break; 375 376 case XDR_DECODE: 377 if ((len <= rstrm->fbtbc) && 378 ((rstrm->in_finger + len) <= rstrm->in_boundry)) { 379 buf = (long *) rstrm->in_finger; 380 rstrm->fbtbc -= len; 381 rstrm->in_finger += len; 382 } 383 break; 384 } 385 return (buf); 386 } 387 388 static void 389 xdrrec_destroy(xdrs) 390 register XDR *xdrs; 391 { 392 register RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; 393 394 mem_free(rstrm->the_buffer, 395 rstrm->sendsize + rstrm->recvsize + BYTES_PER_XDR_UNIT); 396 mem_free((caddr_t)rstrm, sizeof(RECSTREAM)); 397 } 398 399 400 /* 401 * Exported routines to manage xdr records 402 */ 403 404 /* 405 * Before reading (deserializing from the stream, one should always call 406 * this procedure to guarantee proper record alignment. 407 */ 408 bool_t 409 xdrrec_skiprecord(xdrs) 410 XDR *xdrs; 411 { 412 register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 413 414 while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) { 415 if (! skip_input_bytes(rstrm, rstrm->fbtbc)) 416 return (FALSE); 417 rstrm->fbtbc = 0; 418 if ((! rstrm->last_frag) && (! set_input_fragment(rstrm))) 419 return (FALSE); 420 } 421 rstrm->last_frag = FALSE; 422 return (TRUE); 423 } 424 425 /* 426 * Look ahead fuction. 427 * Returns TRUE iff there is no more input in the buffer 428 * after consuming the rest of the current record. 429 */ 430 bool_t 431 xdrrec_eof(xdrs) 432 XDR *xdrs; 433 { 434 register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 435 436 while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) { 437 if (! skip_input_bytes(rstrm, rstrm->fbtbc)) 438 return (TRUE); 439 rstrm->fbtbc = 0; 440 if ((! rstrm->last_frag) && (! set_input_fragment(rstrm))) 441 return (TRUE); 442 } 443 if (rstrm->in_finger == rstrm->in_boundry) 444 return (TRUE); 445 return (FALSE); 446 } 447 448 /* 449 * The client must tell the package when an end-of-record has occurred. 450 * The second paraemters tells whether the record should be flushed to the 451 * (output) tcp stream. (This let's the package support batched or 452 * pipelined procedure calls.) TRUE => immmediate flush to tcp connection. 453 */ 454 bool_t 455 xdrrec_endofrecord(xdrs, sendnow) 456 XDR *xdrs; 457 bool_t sendnow; 458 { 459 register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 460 register u_long len; /* fragment length */ 461 462 if (sendnow || rstrm->frag_sent || 463 ((u_long)rstrm->out_finger + sizeof(u_long) >= 464 (u_long)rstrm->out_boundry)) { 465 rstrm->frag_sent = FALSE; 466 return (flush_out(rstrm, TRUE)); 467 } 468 len = (u_long)(rstrm->out_finger) - (u_long)(rstrm->frag_header) - 469 sizeof(u_long); 470 *(rstrm->frag_header) = htonl((u_long)len | LAST_FRAG); 471 rstrm->frag_header = (u_long *)rstrm->out_finger; 472 rstrm->out_finger += sizeof(u_long); 473 return (TRUE); 474 } 475 476 477 /* 478 * Internal useful routines 479 */ 480 static bool_t 481 flush_out(rstrm, eor) 482 register RECSTREAM *rstrm; 483 bool_t eor; 484 { 485 register u_long eormask = (eor == TRUE) ? LAST_FRAG : 0; 486 register u_long len = (u_long)(rstrm->out_finger) - 487 (u_long)(rstrm->frag_header) - sizeof(u_long); 488 489 *(rstrm->frag_header) = htonl(len | eormask); 490 len = (u_long)(rstrm->out_finger) - (u_long)(rstrm->out_base); 491 if ((*(rstrm->writeit))(rstrm->tcp_handle, rstrm->out_base, (int)len) 492 != (int)len) 493 return (FALSE); 494 rstrm->frag_header = (u_long *)rstrm->out_base; 495 rstrm->out_finger = (caddr_t)rstrm->out_base + sizeof(u_long); 496 return (TRUE); 497 } 498 499 static bool_t /* knows nothing about records! Only about input buffers */ 500 fill_input_buf(rstrm) 501 register RECSTREAM *rstrm; 502 { 503 register caddr_t where; 504 u_int i; 505 register int len; 506 507 where = rstrm->in_base; 508 i = (u_int)rstrm->in_boundry % BYTES_PER_XDR_UNIT; 509 where += i; 510 len = rstrm->in_size - i; 511 if ((len = (*(rstrm->readit))(rstrm->tcp_handle, where, len)) == -1) 512 return (FALSE); 513 rstrm->in_finger = where; 514 where += len; 515 rstrm->in_boundry = where; 516 return (TRUE); 517 } 518 519 static bool_t /* knows nothing about records! Only about input buffers */ 520 get_input_bytes(rstrm, addr, len) 521 register RECSTREAM *rstrm; 522 register caddr_t addr; 523 register int len; 524 { 525 register int current; 526 527 while (len > 0) { 528 current = (int)rstrm->in_boundry - (int)rstrm->in_finger; 529 if (current == 0) { 530 if (! fill_input_buf(rstrm)) 531 return (FALSE); 532 continue; 533 } 534 current = (len < current) ? len : current; 535 bcopy(rstrm->in_finger, addr, current); 536 rstrm->in_finger += current; 537 addr += current; 538 len -= current; 539 } 540 return (TRUE); 541 } 542 543 static bool_t /* next two bytes of the input stream are treated as a header */ 544 set_input_fragment(rstrm) 545 register RECSTREAM *rstrm; 546 { 547 u_long header; 548 549 if (! get_input_bytes(rstrm, (caddr_t)&header, sizeof(header))) 550 return (FALSE); 551 header = (long)ntohl(header); 552 rstrm->last_frag = ((header & LAST_FRAG) == 0) ? FALSE : TRUE; 553 rstrm->fbtbc = header & (~LAST_FRAG); 554 return (TRUE); 555 } 556 557 static bool_t /* consumes input bytes; knows nothing about records! */ 558 skip_input_bytes(rstrm, cnt) 559 register RECSTREAM *rstrm; 560 long cnt; 561 { 562 register int current; 563 564 while (cnt > 0) { 565 current = (int)rstrm->in_boundry - (int)rstrm->in_finger; 566 if (current == 0) { 567 if (! fill_input_buf(rstrm)) 568 return (FALSE); 569 continue; 570 } 571 current = (cnt < current) ? cnt : current; 572 rstrm->in_finger += current; 573 cnt -= current; 574 } 575 return (TRUE); 576 } 577 578 static u_int 579 fix_buf_size(s) 580 register u_int s; 581 { 582 583 if (s < 100) 584 s = 4000; 585 return (RNDUP(s)); 586 } 587
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