xdr_rec.c revision 1.2
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 1.2 1994/03/28 02:19:44 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 static u_int fix_buf_size(); 59 static bool_t flush_out(); 60 static bool_t get_input_bytes(); 61 static bool_t set_input_fragment(); 62 static bool_t skip_input_bytes(); 63 64 static bool_t xdrrec_getlong(); 65 static bool_t xdrrec_putlong(); 66 static bool_t xdrrec_getbytes(); 67 static bool_t xdrrec_putbytes(); 68 static u_int xdrrec_getpos(); 69 static bool_t xdrrec_setpos(); 70 static long * xdrrec_inline(); 71 static void xdrrec_destroy(); 72 73 static struct xdr_ops xdrrec_ops = { 74 xdrrec_getlong, 75 xdrrec_putlong, 76 xdrrec_getbytes, 77 xdrrec_putbytes, 78 xdrrec_getpos, 79 xdrrec_setpos, 80 xdrrec_inline, 81 xdrrec_destroy 82 }; 83 84 /* 85 * A record is composed of one or more record fragments. 86 * A record fragment is a two-byte header followed by zero to 87 * 2**32-1 bytes. The header is treated as a long unsigned and is 88 * encode/decoded to the network via htonl/ntohl. The low order 31 bits 89 * are a byte count of the fragment. The highest order bit is a boolean: 90 * 1 => this fragment is the last fragment of the record, 91 * 0 => this fragment is followed by more fragment(s). 92 * 93 * The fragment/record machinery is not general; it is constructed to 94 * meet the needs of xdr and rpc based on tcp. 95 */ 96 97 #define LAST_FRAG ((u_long)(1 << 31)) 98 99 typedef struct rec_strm { 100 caddr_t tcp_handle; 101 caddr_t the_buffer; 102 /* 103 * out-goung bits 104 */ 105 int (*writeit)(); 106 caddr_t out_base; /* output buffer (points to frag header) */ 107 caddr_t out_finger; /* next output position */ 108 caddr_t out_boundry; /* data cannot up to this address */ 109 u_long *frag_header; /* beginning of curren fragment */ 110 bool_t frag_sent; /* true if buffer sent in middle of record */ 111 /* 112 * in-coming bits 113 */ 114 int (*readit)(); 115 u_long in_size; /* fixed size of the input buffer */ 116 caddr_t in_base; 117 caddr_t in_finger; /* location of next byte to be had */ 118 caddr_t in_boundry; /* can read up to this location */ 119 long fbtbc; /* fragment bytes to be consumed */ 120 bool_t last_frag; 121 u_int sendsize; 122 u_int recvsize; 123 } RECSTREAM; 124 125 126 /* 127 * Create an xdr handle for xdrrec 128 * xdrrec_create fills in xdrs. Sendsize and recvsize are 129 * send and recv buffer sizes (0 => use default). 130 * tcp_handle is an opaque handle that is passed as the first parameter to 131 * the procedures readit and writeit. Readit and writeit are read and 132 * write respectively. They are like the system 133 * calls expect that they take an opaque handle rather than an fd. 134 */ 135 void 136 xdrrec_create(xdrs, sendsize, recvsize, tcp_handle, readit, writeit) 137 register XDR *xdrs; 138 register u_int sendsize; 139 register u_int recvsize; 140 caddr_t tcp_handle; 141 int (*readit)(); /* like read, but pass it a tcp_handle, not sock */ 142 int (*writeit)(); /* like write, but pass it a tcp_handle, not sock */ 143 { 144 register RECSTREAM *rstrm = 145 (RECSTREAM *)mem_alloc(sizeof(RECSTREAM)); 146 147 if (rstrm == NULL) { 148 (void)fprintf(stderr, "xdrrec_create: out of memory\n"); 149 /* 150 * This is bad. Should rework xdrrec_create to 151 * return a handle, and in this case return NULL 152 */ 153 return; 154 } 155 /* 156 * adjust sizes and allocate buffer quad byte aligned 157 */ 158 rstrm->sendsize = sendsize = fix_buf_size(sendsize); 159 rstrm->recvsize = recvsize = fix_buf_size(recvsize); 160 rstrm->the_buffer = mem_alloc(sendsize + recvsize + BYTES_PER_XDR_UNIT); 161 if (rstrm->the_buffer == NULL) { 162 (void)fprintf(stderr, "xdrrec_create: out of memory\n"); 163 return; 164 } 165 for (rstrm->out_base = rstrm->the_buffer; 166 (u_int)rstrm->out_base % BYTES_PER_XDR_UNIT != 0; 167 rstrm->out_base++); 168 rstrm->in_base = rstrm->out_base + sendsize; 169 /* 170 * now the rest ... 171 */ 172 xdrs->x_ops = &xdrrec_ops; 173 xdrs->x_private = (caddr_t)rstrm; 174 rstrm->tcp_handle = tcp_handle; 175 rstrm->readit = readit; 176 rstrm->writeit = writeit; 177 rstrm->out_finger = rstrm->out_boundry = rstrm->out_base; 178 rstrm->frag_header = (u_long *)rstrm->out_base; 179 rstrm->out_finger += sizeof(u_long); 180 rstrm->out_boundry += sendsize; 181 rstrm->frag_sent = FALSE; 182 rstrm->in_size = recvsize; 183 rstrm->in_boundry = rstrm->in_base; 184 rstrm->in_finger = (rstrm->in_boundry += recvsize); 185 rstrm->fbtbc = 0; 186 rstrm->last_frag = TRUE; 187 } 188 189 190 /* 191 * The reoutines defined below are the xdr ops which will go into the 192 * xdr handle filled in by xdrrec_create. 193 */ 194 195 static bool_t 196 xdrrec_getlong(xdrs, lp) 197 XDR *xdrs; 198 long *lp; 199 { 200 register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 201 register long *buflp = (long *)(rstrm->in_finger); 202 long mylong; 203 204 /* first try the inline, fast case */ 205 if ((rstrm->fbtbc >= sizeof(long)) && 206 (((int)rstrm->in_boundry - (int)buflp) >= sizeof(long))) { 207 *lp = (long)ntohl((u_long)(*buflp)); 208 rstrm->fbtbc -= sizeof(long); 209 rstrm->in_finger += sizeof(long); 210 } else { 211 if (! xdrrec_getbytes(xdrs, (caddr_t)&mylong, sizeof(long))) 212 return (FALSE); 213 *lp = (long)ntohl((u_long)mylong); 214 } 215 return (TRUE); 216 } 217 218 static bool_t 219 xdrrec_putlong(xdrs, lp) 220 XDR *xdrs; 221 long *lp; 222 { 223 register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 224 register long *dest_lp = ((long *)(rstrm->out_finger)); 225 226 if ((rstrm->out_finger += sizeof(long)) > rstrm->out_boundry) { 227 /* 228 * this case should almost never happen so the code is 229 * inefficient 230 */ 231 rstrm->out_finger -= sizeof(long); 232 rstrm->frag_sent = TRUE; 233 if (! flush_out(rstrm, FALSE)) 234 return (FALSE); 235 dest_lp = ((long *)(rstrm->out_finger)); 236 rstrm->out_finger += sizeof(long); 237 } 238 *dest_lp = (long)htonl((u_long)(*lp)); 239 return (TRUE); 240 } 241 242 static bool_t /* must manage buffers, fragments, and records */ 243 xdrrec_getbytes(xdrs, addr, len) 244 XDR *xdrs; 245 register caddr_t addr; 246 register u_int len; 247 { 248 register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 249 register int current; 250 251 while (len > 0) { 252 current = rstrm->fbtbc; 253 if (current == 0) { 254 if (rstrm->last_frag) 255 return (FALSE); 256 if (! set_input_fragment(rstrm)) 257 return (FALSE); 258 continue; 259 } 260 current = (len < current) ? len : current; 261 if (! get_input_bytes(rstrm, addr, current)) 262 return (FALSE); 263 addr += current; 264 rstrm->fbtbc -= current; 265 len -= current; 266 } 267 return (TRUE); 268 } 269 270 static bool_t 271 xdrrec_putbytes(xdrs, addr, len) 272 XDR *xdrs; 273 register caddr_t addr; 274 register u_int len; 275 { 276 register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 277 register int current; 278 279 while (len > 0) { 280 current = (u_int)rstrm->out_boundry - (u_int)rstrm->out_finger; 281 current = (len < current) ? len : current; 282 bcopy(addr, rstrm->out_finger, current); 283 rstrm->out_finger += current; 284 addr += current; 285 len -= current; 286 if (rstrm->out_finger == rstrm->out_boundry) { 287 rstrm->frag_sent = TRUE; 288 if (! flush_out(rstrm, FALSE)) 289 return (FALSE); 290 } 291 } 292 return (TRUE); 293 } 294 295 static u_int 296 xdrrec_getpos(xdrs) 297 register XDR *xdrs; 298 { 299 register RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; 300 register long pos; 301 302 pos = lseek((int)rstrm->tcp_handle, (long) 0, 1); 303 if (pos != -1) 304 switch (xdrs->x_op) { 305 306 case XDR_ENCODE: 307 pos += rstrm->out_finger - rstrm->out_base; 308 break; 309 310 case XDR_DECODE: 311 pos -= rstrm->in_boundry - rstrm->in_finger; 312 break; 313 314 default: 315 pos = (u_int) -1; 316 break; 317 } 318 return ((u_int) pos); 319 } 320 321 static bool_t 322 xdrrec_setpos(xdrs, pos) 323 register XDR *xdrs; 324 u_int pos; 325 { 326 register RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; 327 u_int currpos = xdrrec_getpos(xdrs); 328 int delta = currpos - pos; 329 caddr_t newpos; 330 331 if ((int)currpos != -1) 332 switch (xdrs->x_op) { 333 334 case XDR_ENCODE: 335 newpos = rstrm->out_finger - delta; 336 if ((newpos > (caddr_t)(rstrm->frag_header)) && 337 (newpos < rstrm->out_boundry)) { 338 rstrm->out_finger = newpos; 339 return (TRUE); 340 } 341 break; 342 343 case XDR_DECODE: 344 newpos = rstrm->in_finger - delta; 345 if ((delta < (int)(rstrm->fbtbc)) && 346 (newpos <= rstrm->in_boundry) && 347 (newpos >= rstrm->in_base)) { 348 rstrm->in_finger = newpos; 349 rstrm->fbtbc -= delta; 350 return (TRUE); 351 } 352 break; 353 } 354 return (FALSE); 355 } 356 357 static long * 358 xdrrec_inline(xdrs, len) 359 register XDR *xdrs; 360 int len; 361 { 362 register RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; 363 long * buf = NULL; 364 365 switch (xdrs->x_op) { 366 367 case XDR_ENCODE: 368 if ((rstrm->out_finger + len) <= rstrm->out_boundry) { 369 buf = (long *) rstrm->out_finger; 370 rstrm->out_finger += len; 371 } 372 break; 373 374 case XDR_DECODE: 375 if ((len <= rstrm->fbtbc) && 376 ((rstrm->in_finger + len) <= rstrm->in_boundry)) { 377 buf = (long *) rstrm->in_finger; 378 rstrm->fbtbc -= len; 379 rstrm->in_finger += len; 380 } 381 break; 382 } 383 return (buf); 384 } 385 386 static void 387 xdrrec_destroy(xdrs) 388 register XDR *xdrs; 389 { 390 register RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; 391 392 mem_free(rstrm->the_buffer, 393 rstrm->sendsize + rstrm->recvsize + BYTES_PER_XDR_UNIT); 394 mem_free((caddr_t)rstrm, sizeof(RECSTREAM)); 395 } 396 397 398 /* 399 * Exported routines to manage xdr records 400 */ 401 402 /* 403 * Before reading (deserializing from the stream, one should always call 404 * this procedure to guarantee proper record alignment. 405 */ 406 bool_t 407 xdrrec_skiprecord(xdrs) 408 XDR *xdrs; 409 { 410 register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 411 412 while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) { 413 if (! skip_input_bytes(rstrm, rstrm->fbtbc)) 414 return (FALSE); 415 rstrm->fbtbc = 0; 416 if ((! rstrm->last_frag) && (! set_input_fragment(rstrm))) 417 return (FALSE); 418 } 419 rstrm->last_frag = FALSE; 420 return (TRUE); 421 } 422 423 /* 424 * Look ahead fuction. 425 * Returns TRUE iff there is no more input in the buffer 426 * after consuming the rest of the current record. 427 */ 428 bool_t 429 xdrrec_eof(xdrs) 430 XDR *xdrs; 431 { 432 register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 433 434 while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) { 435 if (! skip_input_bytes(rstrm, rstrm->fbtbc)) 436 return (TRUE); 437 rstrm->fbtbc = 0; 438 if ((! rstrm->last_frag) && (! set_input_fragment(rstrm))) 439 return (TRUE); 440 } 441 if (rstrm->in_finger == rstrm->in_boundry) 442 return (TRUE); 443 return (FALSE); 444 } 445 446 /* 447 * The client must tell the package when an end-of-record has occurred. 448 * The second paraemters tells whether the record should be flushed to the 449 * (output) tcp stream. (This let's the package support batched or 450 * pipelined procedure calls.) TRUE => immmediate flush to tcp connection. 451 */ 452 bool_t 453 xdrrec_endofrecord(xdrs, sendnow) 454 XDR *xdrs; 455 bool_t sendnow; 456 { 457 register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 458 register u_long len; /* fragment length */ 459 460 if (sendnow || rstrm->frag_sent || 461 ((u_long)rstrm->out_finger + sizeof(u_long) >= 462 (u_long)rstrm->out_boundry)) { 463 rstrm->frag_sent = FALSE; 464 return (flush_out(rstrm, TRUE)); 465 } 466 len = (u_long)(rstrm->out_finger) - (u_long)(rstrm->frag_header) - 467 sizeof(u_long); 468 *(rstrm->frag_header) = htonl((u_long)len | LAST_FRAG); 469 rstrm->frag_header = (u_long *)rstrm->out_finger; 470 rstrm->out_finger += sizeof(u_long); 471 return (TRUE); 472 } 473 474 475 /* 476 * Internal useful routines 477 */ 478 static bool_t 479 flush_out(rstrm, eor) 480 register RECSTREAM *rstrm; 481 bool_t eor; 482 { 483 register u_long eormask = (eor == TRUE) ? LAST_FRAG : 0; 484 register u_long len = (u_long)(rstrm->out_finger) - 485 (u_long)(rstrm->frag_header) - sizeof(u_long); 486 487 *(rstrm->frag_header) = htonl(len | eormask); 488 len = (u_long)(rstrm->out_finger) - (u_long)(rstrm->out_base); 489 if ((*(rstrm->writeit))(rstrm->tcp_handle, rstrm->out_base, (int)len) 490 != (int)len) 491 return (FALSE); 492 rstrm->frag_header = (u_long *)rstrm->out_base; 493 rstrm->out_finger = (caddr_t)rstrm->out_base + sizeof(u_long); 494 return (TRUE); 495 } 496 497 static bool_t /* knows nothing about records! Only about input buffers */ 498 fill_input_buf(rstrm) 499 register RECSTREAM *rstrm; 500 { 501 register caddr_t where; 502 u_int i; 503 register int len; 504 505 where = rstrm->in_base; 506 i = (u_int)rstrm->in_boundry % BYTES_PER_XDR_UNIT; 507 where += i; 508 len = rstrm->in_size - i; 509 if ((len = (*(rstrm->readit))(rstrm->tcp_handle, where, len)) == -1) 510 return (FALSE); 511 rstrm->in_finger = where; 512 where += len; 513 rstrm->in_boundry = where; 514 return (TRUE); 515 } 516 517 static bool_t /* knows nothing about records! Only about input buffers */ 518 get_input_bytes(rstrm, addr, len) 519 register RECSTREAM *rstrm; 520 register caddr_t addr; 521 register int len; 522 { 523 register int current; 524 525 while (len > 0) { 526 current = (int)rstrm->in_boundry - (int)rstrm->in_finger; 527 if (current == 0) { 528 if (! fill_input_buf(rstrm)) 529 return (FALSE); 530 continue; 531 } 532 current = (len < current) ? len : current; 533 bcopy(rstrm->in_finger, addr, current); 534 rstrm->in_finger += current; 535 addr += current; 536 len -= current; 537 } 538 return (TRUE); 539 } 540 541 static bool_t /* next two bytes of the input stream are treated as a header */ 542 set_input_fragment(rstrm) 543 register RECSTREAM *rstrm; 544 { 545 u_long header; 546 547 if (! get_input_bytes(rstrm, (caddr_t)&header, sizeof(header))) 548 return (FALSE); 549 header = (long)ntohl(header); 550 rstrm->last_frag = ((header & LAST_FRAG) == 0) ? FALSE : TRUE; 551 rstrm->fbtbc = header & (~LAST_FRAG); 552 return (TRUE); 553 } 554 555 static bool_t /* consumes input bytes; knows nothing about records! */ 556 skip_input_bytes(rstrm, cnt) 557 register RECSTREAM *rstrm; 558 long cnt; 559 { 560 register int current; 561 562 while (cnt > 0) { 563 current = (int)rstrm->in_boundry - (int)rstrm->in_finger; 564 if (current == 0) { 565 if (! fill_input_buf(rstrm)) 566 return (FALSE); 567 continue; 568 } 569 current = (cnt < current) ? cnt : current; 570 rstrm->in_finger += current; 571 cnt -= current; 572 } 573 return (TRUE); 574 } 575 576 static u_int 577 fix_buf_size(s) 578 register u_int s; 579 { 580 581 if (s < 100) 582 s = 4000; 583 return (RNDUP(s)); 584 } 585
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