xdr_rec.c revision 1.9
1 /* $NetBSD: xdr_rec.c,v 1.9 1998/02/10 04:55:02 lukem Exp $ */ 2 3 /* 4 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for 5 * unrestricted use provided that this legend is included on all tape 6 * media and as a part of the software program in whole or part. Users 7 * may copy or modify Sun RPC without charge, but are not authorized 8 * to license or distribute it to anyone else except as part of a product or 9 * program developed by the user. 10 * 11 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE 12 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR 13 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE. 14 * 15 * Sun RPC is provided with no support and without any obligation on the 16 * part of Sun Microsystems, Inc. to assist in its use, correction, 17 * modification or enhancement. 18 * 19 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE 20 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC 21 * OR ANY PART THEREOF. 22 * 23 * In no event will Sun Microsystems, Inc. be liable for any lost revenue 24 * or profits or other special, indirect and consequential damages, even if 25 * Sun has been advised of the possibility of such damages. 26 * 27 * Sun Microsystems, Inc. 28 * 2550 Garcia Avenue 29 * Mountain View, California 94043 30 */ 31 32 #include <sys/cdefs.h> 33 #if defined(LIBC_SCCS) && !defined(lint) 34 #if 0 35 static char *sccsid = "@(#)xdr_rec.c 1.21 87/08/11 Copyr 1984 Sun Micro"; 36 static char *sccsid = "@(#)xdr_rec.c 2.2 88/08/01 4.0 RPCSRC"; 37 #else 38 __RCSID("$NetBSD: xdr_rec.c,v 1.9 1998/02/10 04:55:02 lukem Exp $"); 39 #endif 40 #endif 41 42 /* 43 * xdr_rec.c, Implements TCP/IP based XDR streams with a "record marking" 44 * layer above tcp (for rpc's use). 45 * 46 * Copyright (C) 1984, Sun Microsystems, Inc. 47 * 48 * These routines interface XDRSTREAMS to a tcp/ip connection. 49 * There is a record marking layer between the xdr stream 50 * and the tcp transport level. A record is composed on one or more 51 * record fragments. A record fragment is a thirty-two bit header followed 52 * by n bytes of data, where n is contained in the header. The header 53 * is represented as a htonl(u_int32_t). Thegh order bit encodes 54 * whether or not the fragment is the last fragment of the record 55 * (1 => fragment is last, 0 => more fragments to follow. 56 * The other 31 bits encode the byte length of the fragment. 57 */ 58 59 #include "namespace.h" 60 61 #include <sys/types.h> 62 63 #include <netinet/in.h> 64 65 #include <err.h> 66 #include <stdio.h> 67 #include <stdlib.h> 68 #include <string.h> 69 70 #include <rpc/types.h> 71 #include <rpc/xdr.h> 72 73 #ifdef __weak_alias 74 __weak_alias(xdrrec_create,_xdrrec_create); 75 __weak_alias(xdrrec_endofrecord,_xdrrec_endofrecord); 76 __weak_alias(xdrrec_eof,_xdrrec_eof); 77 __weak_alias(xdrrec_skiprecord,_xdrrec_skiprecord); 78 #endif 79 80 static bool_t xdrrec_getlong __P((XDR *, int32_t *)); 81 static bool_t xdrrec_putlong __P((XDR *, int32_t *)); 82 static bool_t xdrrec_getbytes __P((XDR *, caddr_t, size_t)); 83 84 static bool_t xdrrec_putbytes __P((XDR *, caddr_t, size_t)); 85 static size_t xdrrec_getpos __P((XDR *)); 86 static bool_t xdrrec_setpos __P((XDR *, size_t)); 87 static int32_t *xdrrec_inline __P((XDR *, size_t)); 88 static void xdrrec_destroy __P((XDR *)); 89 90 static struct xdr_ops xdrrec_ops = { 91 xdrrec_getlong, 92 xdrrec_putlong, 93 xdrrec_getbytes, 94 xdrrec_putbytes, 95 xdrrec_getpos, 96 xdrrec_setpos, 97 xdrrec_inline, 98 xdrrec_destroy 99 }; 100 101 /* 102 * A record is composed of one or more record fragments. 103 * A record fragment is a two-byte header followed by zero to 104 * 2**32-1 bytes. The header is treated as a long unsigned and is 105 * encode/decoded to the network via htonl/ntohl. The low order 31 bits 106 * are a byte count of the fragment. The highest order bit is a boolean: 107 * 1 => this fragment is the last fragment of the record, 108 * 0 => this fragment is followed by more fragment(s). 109 * 110 * The fragment/record machinery is not general; it is constructed to 111 * meet the needs of xdr and rpc based on tcp. 112 */ 113 114 #define LAST_FRAG ((u_int32_t)(1 << 31)) 115 116 typedef struct rec_strm { 117 caddr_t tcp_handle; 118 caddr_t the_buffer; 119 /* 120 * out-goung bits 121 */ 122 int (*writeit) __P((caddr_t, caddr_t, size_t)); 123 caddr_t out_base; /* output buffer (points to frag header) */ 124 caddr_t out_finger; /* next output position */ 125 caddr_t out_boundry; /* data cannot up to this address */ 126 u_int32_t *frag_header; /* beginning of current fragment */ 127 bool_t frag_sent; /* true if buffer sent in middle of record */ 128 /* 129 * in-coming bits 130 */ 131 int (*readit) __P((caddr_t , caddr_t , size_t)); 132 u_int32_t in_size; /* fixed size of the input buffer */ 133 caddr_t in_base; 134 caddr_t in_finger; /* location of next byte to be had */ 135 caddr_t in_boundry; /* can read up to this location */ 136 u_int32_t fbtbc; /* fragment bytes to be consumed */ 137 bool_t last_frag; 138 size_t sendsize; 139 size_t recvsize; 140 } RECSTREAM; 141 142 static size_t fix_buf_size __P((size_t)); 143 static bool_t flush_out __P((RECSTREAM *, bool_t)); 144 static bool_t fill_input_buf __P((RECSTREAM *)); 145 static bool_t get_input_bytes __P((RECSTREAM *, caddr_t, int)); 146 static bool_t set_input_fragment __P((RECSTREAM *)); 147 static bool_t skip_input_bytes __P((RECSTREAM *, int32_t)); 148 149 150 /* 151 * Create an xdr handle for xdrrec 152 * xdrrec_create fills in xdrs. Sendsize and recvsize are 153 * send and recv buffer sizes (0 => use default). 154 * tcp_handle is an opaque handle that is passed as the first parameter to 155 * the procedures readit and writeit. Readit and writeit are read and 156 * write respectively. They are like the system 157 * calls expect that they take an opaque handle rather than an fd. 158 */ 159 void 160 xdrrec_create(xdrs, sendsize, recvsize, tcp_handle, readit, writeit) 161 XDR *xdrs; 162 size_t sendsize; 163 size_t recvsize; 164 caddr_t tcp_handle; 165 /* like read, but pass it a tcp_handle, not sock */ 166 int (*readit) __P((caddr_t, caddr_t, size_t)); 167 /* like write, but pass it a tcp_handle, not sock */ 168 int (*writeit) __P((caddr_t, caddr_t, size_t)); 169 { 170 RECSTREAM *rstrm = 171 (RECSTREAM *)mem_alloc(sizeof(RECSTREAM)); 172 173 if (rstrm == NULL) { 174 warnx("xdrrec_create: out of memory"); 175 /* 176 * This is bad. Should rework xdrrec_create to 177 * return a handle, and in this case return NULL 178 */ 179 return; 180 } 181 /* 182 * adjust sizes and allocate buffer quad byte aligned 183 */ 184 rstrm->sendsize = sendsize = fix_buf_size(sendsize); 185 rstrm->recvsize = recvsize = fix_buf_size(recvsize); 186 rstrm->the_buffer = 187 mem_alloc((size_t)(sendsize + recvsize + BYTES_PER_XDR_UNIT)); 188 if (rstrm->the_buffer == NULL) { 189 warnx("xdrrec_create: out of memory"); 190 return; 191 } 192 for (rstrm->out_base = rstrm->the_buffer; 193 (u_int32_t)rstrm->out_base % BYTES_PER_XDR_UNIT != 0; 194 rstrm->out_base++); 195 rstrm->in_base = rstrm->out_base + sendsize; 196 /* 197 * now the rest ... 198 */ 199 xdrs->x_ops = &xdrrec_ops; 200 xdrs->x_private = (caddr_t)rstrm; 201 rstrm->tcp_handle = tcp_handle; 202 rstrm->readit = readit; 203 rstrm->writeit = writeit; 204 rstrm->out_finger = rstrm->out_boundry = rstrm->out_base; 205 rstrm->frag_header = (u_int32_t *)rstrm->out_base; 206 rstrm->out_finger += sizeof(u_int32_t); 207 rstrm->out_boundry += sendsize; 208 rstrm->frag_sent = FALSE; 209 rstrm->in_size = recvsize; 210 rstrm->in_boundry = rstrm->in_base; 211 rstrm->in_finger = (rstrm->in_boundry += recvsize); 212 rstrm->fbtbc = 0; 213 rstrm->last_frag = TRUE; 214 } 215 216 217 /* 218 * The routines defined below are the xdr ops which will go into the 219 * xdr handle filled in by xdrrec_create. 220 */ 221 222 static bool_t 223 xdrrec_getlong(xdrs, lp) 224 XDR *xdrs; 225 int32_t *lp; 226 { 227 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 228 int32_t *buflp = (int32_t *)(rstrm->in_finger); 229 int32_t mylong; 230 231 /* first try the inline, fast case */ 232 if ((rstrm->fbtbc >= sizeof(int32_t)) 233 && (((int32_t)rstrm->in_boundry - (int32_t)buflp) 234 >= sizeof(int32_t))) { 235 *lp = (int32_t)ntohl((u_int32_t)(*buflp)); 236 rstrm->fbtbc -= sizeof(int32_t); 237 rstrm->in_finger += sizeof(int32_t); 238 } else { 239 if (! xdrrec_getbytes(xdrs, (caddr_t)&mylong, sizeof(int32_t))) 240 return (FALSE); 241 *lp = (int32_t)ntohl((u_int32_t)mylong); 242 } 243 return (TRUE); 244 } 245 246 static bool_t 247 xdrrec_putlong(xdrs, lp) 248 XDR *xdrs; 249 int32_t *lp; 250 { 251 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 252 int32_t *dest_lp = ((int32_t *)(rstrm->out_finger)); 253 254 if ((rstrm->out_finger += sizeof(int32_t)) > rstrm->out_boundry) { 255 /* 256 * this case should almost never happen so the code is 257 * inefficient 258 */ 259 rstrm->out_finger -= sizeof(int32_t); 260 rstrm->frag_sent = TRUE; 261 if (! flush_out(rstrm, FALSE)) 262 return (FALSE); 263 dest_lp = ((int32_t *)(rstrm->out_finger)); 264 rstrm->out_finger += sizeof(int32_t); 265 } 266 *dest_lp = (int32_t)htonl((u_int32_t)(*lp)); 267 return (TRUE); 268 } 269 270 static bool_t /* must manage buffers, fragments, and records */ 271 xdrrec_getbytes(xdrs, addr, len) 272 XDR *xdrs; 273 caddr_t addr; 274 size_t len; 275 { 276 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 277 int current; 278 279 while (len > 0) { 280 current = rstrm->fbtbc; 281 if (current == 0) { 282 if (rstrm->last_frag) 283 return (FALSE); 284 if (! set_input_fragment(rstrm)) 285 return (FALSE); 286 continue; 287 } 288 current = (len < current) ? len : current; 289 if (! get_input_bytes(rstrm, addr, current)) 290 return (FALSE); 291 addr += current; 292 rstrm->fbtbc -= current; 293 len -= current; 294 } 295 return (TRUE); 296 } 297 298 static bool_t 299 xdrrec_putbytes(xdrs, addr, len) 300 XDR *xdrs; 301 caddr_t addr; 302 size_t len; 303 { 304 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 305 int32_t current; 306 307 while (len > 0) { 308 current = (u_int32_t)rstrm->out_boundry - 309 (u_int32_t)rstrm->out_finger; 310 current = (len < current) ? len : current; 311 memmove(rstrm->out_finger, addr, current); 312 rstrm->out_finger += current; 313 addr += current; 314 len -= current; 315 if (rstrm->out_finger == rstrm->out_boundry) { 316 rstrm->frag_sent = TRUE; 317 if (! flush_out(rstrm, FALSE)) 318 return (FALSE); 319 } 320 } 321 return (TRUE); 322 } 323 324 static size_t 325 xdrrec_getpos(xdrs) 326 XDR *xdrs; 327 { 328 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; 329 int32_t pos; 330 331 pos = lseek((off_t)(int32_t)rstrm->tcp_handle, 0, 1); 332 if (pos != -1) 333 switch (xdrs->x_op) { 334 335 case XDR_ENCODE: 336 pos += rstrm->out_finger - rstrm->out_base; 337 break; 338 339 case XDR_DECODE: 340 pos -= rstrm->in_boundry - rstrm->in_finger; 341 break; 342 343 default: 344 pos = (size_t) -1; 345 break; 346 } 347 return ((size_t) pos); 348 } 349 350 static bool_t 351 xdrrec_setpos(xdrs, pos) 352 XDR *xdrs; 353 size_t pos; 354 { 355 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; 356 size_t currpos = xdrrec_getpos(xdrs); 357 int delta = currpos - pos; 358 caddr_t newpos; 359 360 if ((int)currpos != -1) 361 switch (xdrs->x_op) { 362 363 case XDR_ENCODE: 364 newpos = rstrm->out_finger - delta; 365 if ((newpos > (caddr_t)(rstrm->frag_header)) && 366 (newpos < rstrm->out_boundry)) { 367 rstrm->out_finger = newpos; 368 return (TRUE); 369 } 370 break; 371 372 case XDR_DECODE: 373 newpos = rstrm->in_finger - delta; 374 if ((delta < (int)(rstrm->fbtbc)) && 375 (newpos <= rstrm->in_boundry) && 376 (newpos >= rstrm->in_base)) { 377 rstrm->in_finger = newpos; 378 rstrm->fbtbc -= delta; 379 return (TRUE); 380 } 381 break; 382 383 case XDR_FREE: 384 break; 385 } 386 return (FALSE); 387 } 388 389 static int32_t * 390 xdrrec_inline(xdrs, len) 391 XDR *xdrs; 392 size_t len; 393 { 394 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; 395 int32_t *buf = NULL; 396 397 switch (xdrs->x_op) { 398 399 case XDR_ENCODE: 400 if ((rstrm->out_finger + len) <= rstrm->out_boundry) { 401 buf = (int32_t *) rstrm->out_finger; 402 rstrm->out_finger += len; 403 } 404 break; 405 406 case XDR_DECODE: 407 if ((len <= rstrm->fbtbc) && 408 ((rstrm->in_finger + len) <= rstrm->in_boundry)) { 409 buf = (int32_t *) rstrm->in_finger; 410 rstrm->fbtbc -= len; 411 rstrm->in_finger += len; 412 } 413 break; 414 415 case XDR_FREE: 416 break; 417 } 418 return (buf); 419 } 420 421 static void 422 xdrrec_destroy(xdrs) 423 XDR *xdrs; 424 { 425 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; 426 427 mem_free(rstrm->the_buffer, 428 rstrm->sendsize + rstrm->recvsize + BYTES_PER_XDR_UNIT); 429 mem_free(rstrm, sizeof(RECSTREAM)); 430 } 431 432 433 /* 434 * Exported routines to manage xdr records 435 */ 436 437 /* 438 * Before reading (deserializing from the stream, one should always call 439 * this procedure to guarantee proper record alignment. 440 */ 441 bool_t 442 xdrrec_skiprecord(xdrs) 443 XDR *xdrs; 444 { 445 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 446 447 while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) { 448 if (! skip_input_bytes(rstrm, rstrm->fbtbc)) 449 return (FALSE); 450 rstrm->fbtbc = 0; 451 if ((! rstrm->last_frag) && (! set_input_fragment(rstrm))) 452 return (FALSE); 453 } 454 rstrm->last_frag = FALSE; 455 return (TRUE); 456 } 457 458 /* 459 * Look ahead fuction. 460 * Returns TRUE iff there is no more input in the buffer 461 * after consuming the rest of the current record. 462 */ 463 bool_t 464 xdrrec_eof(xdrs) 465 XDR *xdrs; 466 { 467 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 468 469 while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) { 470 if (! skip_input_bytes(rstrm, rstrm->fbtbc)) 471 return (TRUE); 472 rstrm->fbtbc = 0; 473 if ((! rstrm->last_frag) && (! set_input_fragment(rstrm))) 474 return (TRUE); 475 } 476 if (rstrm->in_finger == rstrm->in_boundry) 477 return (TRUE); 478 return (FALSE); 479 } 480 481 /* 482 * The client must tell the package when an end-of-record has occurred. 483 * The second paraemters tells whether the record should be flushed to the 484 * (output) tcp stream. (This let's the package support batched or 485 * pipelined procedure calls.) TRUE => immmediate flush to tcp connection. 486 */ 487 bool_t 488 xdrrec_endofrecord(xdrs, sendnow) 489 XDR *xdrs; 490 bool_t sendnow; 491 { 492 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 493 u_int32_t len; /* fragment length */ 494 495 if (sendnow || rstrm->frag_sent || 496 ((u_int32_t)rstrm->out_finger + sizeof(u_int32_t) >= 497 (u_int32_t)rstrm->out_boundry)) { 498 rstrm->frag_sent = FALSE; 499 return (flush_out(rstrm, TRUE)); 500 } 501 len = (u_int32_t)(rstrm->out_finger) - (u_long)(rstrm->frag_header) - 502 sizeof(u_int32_t); 503 *(rstrm->frag_header) = htonl((u_int32_t)len | LAST_FRAG); 504 rstrm->frag_header = (u_int32_t *)rstrm->out_finger; 505 rstrm->out_finger += sizeof(u_int32_t); 506 return (TRUE); 507 } 508 509 510 /* 511 * Internal useful routines 512 */ 513 static bool_t 514 flush_out(rstrm, eor) 515 RECSTREAM *rstrm; 516 bool_t eor; 517 { 518 u_int32_t eormask = (eor == TRUE) ? LAST_FRAG : 0; 519 u_int32_t len = (u_long)(rstrm->out_finger) - 520 (u_long)(rstrm->frag_header) - sizeof(u_int32_t); 521 522 *(rstrm->frag_header) = htonl(len | eormask); 523 len = (u_long)(rstrm->out_finger) - (u_long)(rstrm->out_base); 524 if ((*(rstrm->writeit))(rstrm->tcp_handle, rstrm->out_base, (int)len) 525 != (int)len) 526 return (FALSE); 527 rstrm->frag_header = (u_int32_t *)rstrm->out_base; 528 rstrm->out_finger = (caddr_t)rstrm->out_base + sizeof(u_int32_t); 529 return (TRUE); 530 } 531 532 static bool_t /* knows nothing about records! Only about input buffers */ 533 fill_input_buf(rstrm) 534 RECSTREAM *rstrm; 535 { 536 caddr_t where; 537 u_int32_t i; 538 long len; 539 540 where = rstrm->in_base; 541 i = (u_int32_t)rstrm->in_boundry % BYTES_PER_XDR_UNIT; 542 where += i; 543 len = rstrm->in_size - i; 544 if ((len = (*(rstrm->readit))(rstrm->tcp_handle, where, len)) == -1) 545 return (FALSE); 546 rstrm->in_finger = where; 547 where += len; 548 rstrm->in_boundry = where; 549 return (TRUE); 550 } 551 552 static bool_t /* knows nothing about records! Only about input buffers */ 553 get_input_bytes(rstrm, addr, len) 554 RECSTREAM *rstrm; 555 caddr_t addr; 556 int len; 557 { 558 long current; 559 560 while (len > 0) { 561 current = (long)rstrm->in_boundry - (long)rstrm->in_finger; 562 if (current == 0) { 563 if (! fill_input_buf(rstrm)) 564 return (FALSE); 565 continue; 566 } 567 current = (len < current) ? len : current; 568 memmove(addr, rstrm->in_finger, current); 569 rstrm->in_finger += current; 570 addr += current; 571 len -= current; 572 } 573 return (TRUE); 574 } 575 576 static bool_t /* next two bytes of the input stream are treated as a header */ 577 set_input_fragment(rstrm) 578 RECSTREAM *rstrm; 579 { 580 u_int32_t header; 581 582 if (! get_input_bytes(rstrm, (caddr_t)&header, sizeof(header))) 583 return (FALSE); 584 header = (long)ntohl(header); 585 rstrm->last_frag = ((header & LAST_FRAG) == 0) ? FALSE : TRUE; 586 rstrm->fbtbc = header & (~LAST_FRAG); 587 return (TRUE); 588 } 589 590 static bool_t /* consumes input bytes; knows nothing about records! */ 591 skip_input_bytes(rstrm, cnt) 592 RECSTREAM *rstrm; 593 int32_t cnt; 594 { 595 int32_t current; 596 597 while (cnt > 0) { 598 current = (size_t)rstrm->in_boundry - (size_t)rstrm->in_finger; 599 if (current == 0) { 600 if (! fill_input_buf(rstrm)) 601 return (FALSE); 602 continue; 603 } 604 current = (cnt < current) ? cnt : current; 605 rstrm->in_finger += current; 606 cnt -= current; 607 } 608 return (TRUE); 609 } 610 611 static size_t 612 fix_buf_size(s) 613 size_t s; 614 { 615 616 if (s < 100) 617 s = 4000; 618 return (RNDUP(s)); 619 } 620
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