xdr_rec.c revision 1.5.4.1
1 /* $NetBSD: xdr_rec.c,v 1.5.4.1 1996/09/16 23:44:47 jtc 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 #if defined(LIBC_SCCS) && !defined(lint) 32 /*static char *sccsid = "from: @(#)xdr_rec.c 1.21 87/08/11 Copyr 1984 Sun Micro";*/ 33 /*static char *sccsid = "from: @(#)xdr_rec.c 2.2 88/08/01 4.0 RPCSRC";*/ 34 static char *rcsid = "$NetBSD: xdr_rec.c,v 1.5.4.1 1996/09/16 23:44:47 jtc Exp $"; 35 #endif 36 37 /* 38 * xdr_rec.c, Implements TCP/IP based XDR streams with a "record marking" 39 * layer above tcp (for rpc's use). 40 * 41 * Copyright (C) 1984, Sun Microsystems, Inc. 42 * 43 * These routines interface XDRSTREAMS to a tcp/ip connection. 44 * There is a record marking layer between the xdr stream 45 * and the tcp transport level. A record is composed on one or more 46 * record fragments. A record fragment is a thirty-two bit header followed 47 * by n bytes of data, where n is contained in the header. The header 48 * is represented as a htonl(u_long). Thegh order bit encodes 49 * whether or not the fragment is the last fragment of the record 50 * (1 => fragment is last, 0 => more fragments to follow. 51 * The other 31 bits encode the byte length of the fragment. 52 */ 53 54 #include "namespace.h" 55 #include <stdio.h> 56 #include <stdlib.h> 57 #include <rpc/types.h> 58 #include <rpc/xdr.h> 59 #include <netinet/in.h> 60 61 #ifdef __weak_alias 62 __weak_alias(xdrrec_create,_xdrrec_create); 63 __weak_alias(xdrrec_endofrecord,_xdrrec_endofrecord); 64 __weak_alias(xdrrec_eof,_xdrrec_eof); 65 __weak_alias(xdrrec_skiprecord,_xdrrec_skiprecord); 66 #endif 67 68 static u_int fix_buf_size(); 69 static bool_t flush_out(); 70 static bool_t get_input_bytes(); 71 static bool_t set_input_fragment(); 72 static bool_t skip_input_bytes(); 73 74 static bool_t xdrrec_getlong(); 75 static bool_t xdrrec_putlong(); 76 static bool_t xdrrec_getbytes(); 77 static bool_t xdrrec_putbytes(); 78 static u_int xdrrec_getpos(); 79 static bool_t xdrrec_setpos(); 80 static int32_t *xdrrec_inline(); 81 static void xdrrec_destroy(); 82 83 static struct xdr_ops xdrrec_ops = { 84 xdrrec_getlong, 85 xdrrec_putlong, 86 xdrrec_getbytes, 87 xdrrec_putbytes, 88 xdrrec_getpos, 89 xdrrec_setpos, 90 xdrrec_inline, 91 xdrrec_destroy 92 }; 93 94 /* 95 * A record is composed of one or more record fragments. 96 * A record fragment is a two-byte header followed by zero to 97 * 2**32-1 bytes. The header is treated as a long unsigned and is 98 * encode/decoded to the network via htonl/ntohl. The low order 31 bits 99 * are a byte count of the fragment. The highest order bit is a boolean: 100 * 1 => this fragment is the last fragment of the record, 101 * 0 => this fragment is followed by more fragment(s). 102 * 103 * The fragment/record machinery is not general; it is constructed to 104 * meet the needs of xdr and rpc based on tcp. 105 */ 106 107 #define LAST_FRAG ((u_int32_t)(1 << 31)) 108 109 typedef struct rec_strm { 110 caddr_t tcp_handle; 111 caddr_t the_buffer; 112 /* 113 * out-goung bits 114 */ 115 int (*writeit) __P((caddr_t, caddr_t, int)); 116 caddr_t out_base; /* output buffer (points to frag header) */ 117 caddr_t out_finger; /* next output position */ 118 caddr_t out_boundry; /* data cannot up to this address */ 119 u_int32_t *frag_header; /* beginning of curren fragment */ 120 bool_t frag_sent; /* true if buffer sent in middle of record */ 121 /* 122 * in-coming bits 123 */ 124 int (*readit) __P((caddr_t, caddr_t, int)); 125 u_long in_size; /* fixed size of the input buffer */ 126 caddr_t in_base; 127 caddr_t in_finger; /* location of next byte to be had */ 128 caddr_t in_boundry; /* can read up to this location */ 129 long fbtbc; /* fragment bytes to be consumed */ 130 bool_t last_frag; 131 u_int sendsize; 132 u_int recvsize; 133 } RECSTREAM; 134 135 136 /* 137 * Create an xdr handle for xdrrec 138 * xdrrec_create fills in xdrs. Sendsize and recvsize are 139 * send and recv buffer sizes (0 => use default). 140 * tcp_handle is an opaque handle that is passed as the first parameter to 141 * the procedures readit and writeit. Readit and writeit are read and 142 * write respectively. They are like the system 143 * calls expect that they take an opaque handle rather than an fd. 144 */ 145 void 146 xdrrec_create(xdrs, sendsize, recvsize, tcp_handle, readit, writeit) 147 register XDR *xdrs; 148 register u_int sendsize; 149 register u_int recvsize; 150 caddr_t tcp_handle; 151 int (*readit)(); /* like read, but pass it a tcp_handle, not sock */ 152 int (*writeit)(); /* like write, but pass it a tcp_handle, not sock */ 153 { 154 register RECSTREAM *rstrm = 155 (RECSTREAM *)mem_alloc(sizeof(RECSTREAM)); 156 157 if (rstrm == NULL) { 158 (void)fprintf(stderr, "xdrrec_create: out of memory\n"); 159 /* 160 * This is bad. Should rework xdrrec_create to 161 * return a handle, and in this case return NULL 162 */ 163 return; 164 } 165 /* 166 * adjust sizes and allocate buffer quad byte aligned 167 */ 168 rstrm->sendsize = sendsize = fix_buf_size(sendsize); 169 rstrm->recvsize = recvsize = fix_buf_size(recvsize); 170 rstrm->the_buffer = mem_alloc(sendsize + recvsize + BYTES_PER_XDR_UNIT); 171 if (rstrm->the_buffer == NULL) { 172 (void)fprintf(stderr, "xdrrec_create: out of memory\n"); 173 return; 174 } 175 for (rstrm->out_base = rstrm->the_buffer; 176 (u_long)rstrm->out_base % BYTES_PER_XDR_UNIT != 0; 177 rstrm->out_base++); 178 rstrm->in_base = rstrm->out_base + sendsize; 179 /* 180 * now the rest ... 181 */ 182 xdrs->x_ops = &xdrrec_ops; 183 xdrs->x_private = (caddr_t)rstrm; 184 rstrm->tcp_handle = tcp_handle; 185 rstrm->readit = readit; 186 rstrm->writeit = writeit; 187 rstrm->out_finger = rstrm->out_boundry = rstrm->out_base; 188 rstrm->frag_header = (u_int32_t *)rstrm->out_base; 189 rstrm->out_finger += sizeof(u_int32_t); 190 rstrm->out_boundry += sendsize; 191 rstrm->frag_sent = FALSE; 192 rstrm->in_size = recvsize; 193 rstrm->in_boundry = rstrm->in_base; 194 rstrm->in_finger = (rstrm->in_boundry += recvsize); 195 rstrm->fbtbc = 0; 196 rstrm->last_frag = TRUE; 197 } 198 199 200 /* 201 * The reoutines defined below are the xdr ops which will go into the 202 * xdr handle filled in by xdrrec_create. 203 */ 204 205 static bool_t 206 xdrrec_getlong(xdrs, lp) 207 XDR *xdrs; 208 long *lp; 209 { 210 register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 211 register int32_t *buflp = (int32_t *)(rstrm->in_finger); 212 int32_t mylong; 213 214 /* first try the inline, fast case */ 215 if ((rstrm->fbtbc >= sizeof(int32_t)) && 216 (((long)rstrm->in_boundry - (long)buflp) >= sizeof(int32_t))) { 217 *lp = (long)ntohl((u_int32_t)(*buflp)); 218 rstrm->fbtbc -= sizeof(int32_t); 219 rstrm->in_finger += sizeof(int32_t); 220 } else { 221 if (! xdrrec_getbytes(xdrs, (caddr_t)&mylong, sizeof(int32_t))) 222 return (FALSE); 223 *lp = (long)ntohl((u_int32_t)mylong); 224 } 225 return (TRUE); 226 } 227 228 static bool_t 229 xdrrec_putlong(xdrs, lp) 230 XDR *xdrs; 231 long *lp; 232 { 233 register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 234 register int32_t *dest_lp = ((int32_t *)(rstrm->out_finger)); 235 236 if ((rstrm->out_finger += sizeof(int32_t)) > rstrm->out_boundry) { 237 /* 238 * this case should almost never happen so the code is 239 * inefficient 240 */ 241 rstrm->out_finger -= sizeof(int32_t); 242 rstrm->frag_sent = TRUE; 243 if (! flush_out(rstrm, FALSE)) 244 return (FALSE); 245 dest_lp = ((int32_t *)(rstrm->out_finger)); 246 rstrm->out_finger += sizeof(int32_t); 247 } 248 *dest_lp = (int32_t)htonl((u_int32_t)(*lp)); 249 return (TRUE); 250 } 251 252 static bool_t /* must manage buffers, fragments, and records */ 253 xdrrec_getbytes(xdrs, addr, len) 254 XDR *xdrs; 255 register caddr_t addr; 256 register u_int len; 257 { 258 register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 259 register int current; 260 261 while (len > 0) { 262 current = rstrm->fbtbc; 263 if (current == 0) { 264 if (rstrm->last_frag) 265 return (FALSE); 266 if (! set_input_fragment(rstrm)) 267 return (FALSE); 268 continue; 269 } 270 current = (len < current) ? len : current; 271 if (! get_input_bytes(rstrm, addr, current)) 272 return (FALSE); 273 addr += current; 274 rstrm->fbtbc -= current; 275 len -= current; 276 } 277 return (TRUE); 278 } 279 280 static bool_t 281 xdrrec_putbytes(xdrs, addr, len) 282 XDR *xdrs; 283 register caddr_t addr; 284 register u_int len; 285 { 286 register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 287 register long current; 288 289 while (len > 0) { 290 current = (u_long)rstrm->out_boundry - 291 (u_long)rstrm->out_finger; 292 current = (len < current) ? len : current; 293 bcopy(addr, rstrm->out_finger, current); 294 rstrm->out_finger += current; 295 addr += current; 296 len -= current; 297 if (rstrm->out_finger == rstrm->out_boundry) { 298 rstrm->frag_sent = TRUE; 299 if (! flush_out(rstrm, FALSE)) 300 return (FALSE); 301 } 302 } 303 return (TRUE); 304 } 305 306 static u_int 307 xdrrec_getpos(xdrs) 308 register XDR *xdrs; 309 { 310 register RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; 311 register long pos; 312 313 pos = lseek((off_t)(long)rstrm->tcp_handle, 0, 1); 314 if (pos != -1) 315 switch (xdrs->x_op) { 316 317 case XDR_ENCODE: 318 pos += rstrm->out_finger - rstrm->out_base; 319 break; 320 321 case XDR_DECODE: 322 pos -= rstrm->in_boundry - rstrm->in_finger; 323 break; 324 325 default: 326 pos = (u_int) -1; 327 break; 328 } 329 return ((u_int) pos); 330 } 331 332 static bool_t 333 xdrrec_setpos(xdrs, pos) 334 register XDR *xdrs; 335 u_int pos; 336 { 337 register RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; 338 u_int currpos = xdrrec_getpos(xdrs); 339 int delta = currpos - pos; 340 caddr_t newpos; 341 342 if ((int)currpos != -1) 343 switch (xdrs->x_op) { 344 345 case XDR_ENCODE: 346 newpos = rstrm->out_finger - delta; 347 if ((newpos > (caddr_t)(rstrm->frag_header)) && 348 (newpos < rstrm->out_boundry)) { 349 rstrm->out_finger = newpos; 350 return (TRUE); 351 } 352 break; 353 354 case XDR_DECODE: 355 newpos = rstrm->in_finger - delta; 356 if ((delta < (int)(rstrm->fbtbc)) && 357 (newpos <= rstrm->in_boundry) && 358 (newpos >= rstrm->in_base)) { 359 rstrm->in_finger = newpos; 360 rstrm->fbtbc -= delta; 361 return (TRUE); 362 } 363 break; 364 } 365 return (FALSE); 366 } 367 368 static int32_t * 369 xdrrec_inline(xdrs, len) 370 register XDR *xdrs; 371 int len; 372 { 373 register RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; 374 int32_t *buf = NULL; 375 376 switch (xdrs->x_op) { 377 378 case XDR_ENCODE: 379 if ((rstrm->out_finger + len) <= rstrm->out_boundry) { 380 buf = (int32_t *) rstrm->out_finger; 381 rstrm->out_finger += len; 382 } 383 break; 384 385 case XDR_DECODE: 386 if ((len <= rstrm->fbtbc) && 387 ((rstrm->in_finger + len) <= rstrm->in_boundry)) { 388 buf = (int32_t *) rstrm->in_finger; 389 rstrm->fbtbc -= len; 390 rstrm->in_finger += len; 391 } 392 break; 393 } 394 return (buf); 395 } 396 397 static void 398 xdrrec_destroy(xdrs) 399 register XDR *xdrs; 400 { 401 register RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; 402 403 mem_free(rstrm->the_buffer, 404 rstrm->sendsize + rstrm->recvsize + BYTES_PER_XDR_UNIT); 405 mem_free((caddr_t)rstrm, sizeof(RECSTREAM)); 406 } 407 408 409 /* 410 * Exported routines to manage xdr records 411 */ 412 413 /* 414 * Before reading (deserializing from the stream, one should always call 415 * this procedure to guarantee proper record alignment. 416 */ 417 bool_t 418 xdrrec_skiprecord(xdrs) 419 XDR *xdrs; 420 { 421 register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 422 423 while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) { 424 if (! skip_input_bytes(rstrm, rstrm->fbtbc)) 425 return (FALSE); 426 rstrm->fbtbc = 0; 427 if ((! rstrm->last_frag) && (! set_input_fragment(rstrm))) 428 return (FALSE); 429 } 430 rstrm->last_frag = FALSE; 431 return (TRUE); 432 } 433 434 /* 435 * Look ahead fuction. 436 * Returns TRUE iff there is no more input in the buffer 437 * after consuming the rest of the current record. 438 */ 439 bool_t 440 xdrrec_eof(xdrs) 441 XDR *xdrs; 442 { 443 register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 444 445 while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) { 446 if (! skip_input_bytes(rstrm, rstrm->fbtbc)) 447 return (TRUE); 448 rstrm->fbtbc = 0; 449 if ((! rstrm->last_frag) && (! set_input_fragment(rstrm))) 450 return (TRUE); 451 } 452 if (rstrm->in_finger == rstrm->in_boundry) 453 return (TRUE); 454 return (FALSE); 455 } 456 457 /* 458 * The client must tell the package when an end-of-record has occurred. 459 * The second paraemters tells whether the record should be flushed to the 460 * (output) tcp stream. (This let's the package support batched or 461 * pipelined procedure calls.) TRUE => immmediate flush to tcp connection. 462 */ 463 bool_t 464 xdrrec_endofrecord(xdrs, sendnow) 465 XDR *xdrs; 466 bool_t sendnow; 467 { 468 register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 469 register u_long len; /* fragment length */ 470 471 if (sendnow || rstrm->frag_sent || 472 ((u_long)rstrm->out_finger + sizeof(u_int32_t) >= 473 (u_long)rstrm->out_boundry)) { 474 rstrm->frag_sent = FALSE; 475 return (flush_out(rstrm, TRUE)); 476 } 477 len = (u_long)(rstrm->out_finger) - (u_long)(rstrm->frag_header) - 478 sizeof(u_int32_t); 479 *(rstrm->frag_header) = htonl((u_long)len | LAST_FRAG); 480 rstrm->frag_header = (u_int32_t *)rstrm->out_finger; 481 rstrm->out_finger += sizeof(u_int32_t); 482 return (TRUE); 483 } 484 485 486 /* 487 * Internal useful routines 488 */ 489 static bool_t 490 flush_out(rstrm, eor) 491 register RECSTREAM *rstrm; 492 bool_t eor; 493 { 494 register u_long eormask = (eor == TRUE) ? LAST_FRAG : 0; 495 register u_int32_t len = (u_long)(rstrm->out_finger) - 496 (u_long)(rstrm->frag_header) - sizeof(u_int32_t); 497 498 *(rstrm->frag_header) = htonl(len | eormask); 499 len = (u_long)(rstrm->out_finger) - (u_long)(rstrm->out_base); 500 if ((*(rstrm->writeit))(rstrm->tcp_handle, rstrm->out_base, (int)len) 501 != (int)len) 502 return (FALSE); 503 rstrm->frag_header = (u_int32_t *)rstrm->out_base; 504 rstrm->out_finger = (caddr_t)rstrm->out_base + sizeof(u_int32_t); 505 return (TRUE); 506 } 507 508 static bool_t /* knows nothing about records! Only about input buffers */ 509 fill_input_buf(rstrm) 510 register RECSTREAM *rstrm; 511 { 512 register caddr_t where; 513 u_long i; 514 register long len; 515 516 where = rstrm->in_base; 517 i = (u_long)rstrm->in_boundry % BYTES_PER_XDR_UNIT; 518 where += i; 519 len = rstrm->in_size - i; 520 if ((len = (*(rstrm->readit))(rstrm->tcp_handle, where, len)) == -1) 521 return (FALSE); 522 rstrm->in_finger = where; 523 where += len; 524 rstrm->in_boundry = where; 525 return (TRUE); 526 } 527 528 static bool_t /* knows nothing about records! Only about input buffers */ 529 get_input_bytes(rstrm, addr, len) 530 register RECSTREAM *rstrm; 531 register caddr_t addr; 532 register int len; 533 { 534 register long current; 535 536 while (len > 0) { 537 current = (long)rstrm->in_boundry - (long)rstrm->in_finger; 538 if (current == 0) { 539 if (! fill_input_buf(rstrm)) 540 return (FALSE); 541 continue; 542 } 543 current = (len < current) ? len : current; 544 bcopy(rstrm->in_finger, addr, current); 545 rstrm->in_finger += current; 546 addr += current; 547 len -= current; 548 } 549 return (TRUE); 550 } 551 552 static bool_t /* next two bytes of the input stream are treated as a header */ 553 set_input_fragment(rstrm) 554 register RECSTREAM *rstrm; 555 { 556 u_int32_t header; 557 558 if (! get_input_bytes(rstrm, (caddr_t)&header, sizeof(header))) 559 return (FALSE); 560 header = (long)ntohl(header); 561 rstrm->last_frag = ((header & LAST_FRAG) == 0) ? FALSE : TRUE; 562 rstrm->fbtbc = header & (~LAST_FRAG); 563 return (TRUE); 564 } 565 566 static bool_t /* consumes input bytes; knows nothing about records! */ 567 skip_input_bytes(rstrm, cnt) 568 register RECSTREAM *rstrm; 569 long cnt; 570 { 571 register long current; 572 573 while (cnt > 0) { 574 current = (long)rstrm->in_boundry - (long)rstrm->in_finger; 575 if (current == 0) { 576 if (! fill_input_buf(rstrm)) 577 return (FALSE); 578 continue; 579 } 580 current = (cnt < current) ? cnt : current; 581 rstrm->in_finger += current; 582 cnt -= current; 583 } 584 return (TRUE); 585 } 586 587 static u_int 588 fix_buf_size(s) 589 register u_int s; 590 { 591 592 if (s < 100) 593 s = 4000; 594 return (RNDUP(s)); 595 } 596
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