1 /* $NetBSD: xdr_rec.c,v 1.18 2000/07/06 03:10:35 christos 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 1.18 2000/07/06 03:10:35 christos 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_long). 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 *, long *)); 81 static bool_t xdrrec_putlong __P((XDR *, const long *)); 82 static bool_t xdrrec_getbytes __P((XDR *, char *, u_int)); 83 84 static bool_t xdrrec_putbytes __P((XDR *, const char *, u_int)); 85 static u_int xdrrec_getpos __P((XDR *)); 86 static bool_t xdrrec_setpos __P((XDR *, u_int)); 87 static int32_t *xdrrec_inline __P((XDR *, u_int)); 88 static void xdrrec_destroy __P((XDR *)); 89 90 static const 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 char *tcp_handle; 118 char *the_buffer; 119 /* 120 * out-goung bits 121 */ 122 int (*writeit) __P((char *, char *, int)); 123 char *out_base; /* output buffer (points to frag header) */ 124 char *out_finger; /* next output position */ 125 char *out_boundry; /* data cannot up to this address */ 126 u_int32_t *frag_header; /* beginning of curren fragment */ 127 bool_t frag_sent; /* true if buffer sent in middle of record */ 128 /* 129 * in-coming bits 130 */ 131 int (*readit) __P((char *, char *, int)); 132 u_long in_size; /* fixed size of the input buffer */ 133 char *in_base; 134 char *in_finger; /* location of next byte to be had */ 135 char *in_boundry; /* can read up to this location */ 136 long fbtbc; /* fragment bytes to be consumed */ 137 bool_t last_frag; 138 u_int sendsize; 139 u_int recvsize; 140 } RECSTREAM; 141 142 static u_int fix_buf_size __P((u_int)); 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 *, char *, int)); 146 static bool_t set_input_fragment __P((RECSTREAM *)); 147 static bool_t skip_input_bytes __P((RECSTREAM *, long)); 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 u_int sendsize; 163 u_int recvsize; 164 char *tcp_handle; 165 /* like read, but pass it a tcp_handle, not sock */ 166 int (*readit) __P((char *, char *, int)); 167 /* like write, but pass it a tcp_handle, not sock */ 168 int (*writeit) __P((char *, char *, int)); 169 { 170 RECSTREAM *rstrm = mem_alloc(sizeof(RECSTREAM)); 171 172 if (rstrm == NULL) { 173 warnx("xdrrec_create: out of memory"); 174 /* 175 * This is bad. Should rework xdrrec_create to 176 * return a handle, and in this case return NULL 177 */ 178 return; 179 } 180 /* 181 * adjust sizes and allocate buffer quad byte aligned 182 */ 183 rstrm->sendsize = sendsize = fix_buf_size(sendsize); 184 rstrm->recvsize = recvsize = fix_buf_size(recvsize); 185 rstrm->the_buffer = mem_alloc(sendsize + recvsize + BYTES_PER_XDR_UNIT); 186 if (rstrm->the_buffer == NULL) { 187 warnx("xdrrec_create: out of memory"); 188 return; 189 } 190 for (rstrm->out_base = rstrm->the_buffer; 191 (u_long)rstrm->out_base % BYTES_PER_XDR_UNIT != 0; 192 rstrm->out_base++); 193 rstrm->in_base = rstrm->out_base + sendsize; 194 /* 195 * now the rest ... 196 */ 197 xdrs->x_ops = &xdrrec_ops; 198 xdrs->x_private = rstrm; 199 rstrm->tcp_handle = tcp_handle; 200 rstrm->readit = readit; 201 rstrm->writeit = writeit; 202 rstrm->out_finger = rstrm->out_boundry = rstrm->out_base; 203 rstrm->frag_header = (u_int32_t *)(void *)rstrm->out_base; 204 rstrm->out_finger += sizeof(u_int32_t); 205 rstrm->out_boundry += sendsize; 206 rstrm->frag_sent = FALSE; 207 rstrm->in_size = recvsize; 208 rstrm->in_boundry = rstrm->in_base; 209 rstrm->in_finger = (rstrm->in_boundry += recvsize); 210 rstrm->fbtbc = 0; 211 rstrm->last_frag = TRUE; 212 } 213 214 215 /* 216 * The reoutines defined below are the xdr ops which will go into the 217 * xdr handle filled in by xdrrec_create. 218 */ 219 220 static bool_t 221 xdrrec_getlong(xdrs, lp) 222 XDR *xdrs; 223 long *lp; 224 { 225 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 226 int32_t *buflp = (int32_t *)(void *)(rstrm->in_finger); 227 int32_t mylong; 228 229 /* first try the inline, fast case */ 230 if ((rstrm->fbtbc >= sizeof(int32_t)) && 231 (((long)rstrm->in_boundry - (long)buflp) >= sizeof(int32_t))) { 232 *lp = (long)ntohl((u_int32_t)(*buflp)); 233 rstrm->fbtbc -= sizeof(int32_t); 234 rstrm->in_finger += sizeof(int32_t); 235 } else { 236 if (! xdrrec_getbytes(xdrs, (char *)(void *)&mylong, 237 sizeof(int32_t))) 238 return (FALSE); 239 *lp = (long)ntohl((u_int32_t)mylong); 240 } 241 return (TRUE); 242 } 243 244 static bool_t 245 xdrrec_putlong(xdrs, lp) 246 XDR *xdrs; 247 const long *lp; 248 { 249 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 250 int32_t *dest_lp = ((int32_t *)(void *)(rstrm->out_finger)); 251 252 if ((rstrm->out_finger += sizeof(int32_t)) > rstrm->out_boundry) { 253 /* 254 * this case should almost never happen so the code is 255 * inefficient 256 */ 257 rstrm->out_finger -= sizeof(int32_t); 258 rstrm->frag_sent = TRUE; 259 if (! flush_out(rstrm, FALSE)) 260 return (FALSE); 261 dest_lp = ((int32_t *)(void *)(rstrm->out_finger)); 262 rstrm->out_finger += sizeof(int32_t); 263 } 264 *dest_lp = (int32_t)htonl((u_int32_t)(*lp)); 265 return (TRUE); 266 } 267 268 static bool_t /* must manage buffers, fragments, and records */ 269 xdrrec_getbytes(xdrs, addr, len) 270 XDR *xdrs; 271 char *addr; 272 u_int len; 273 { 274 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 275 int current; 276 277 while (len > 0) { 278 current = (int)rstrm->fbtbc; 279 if (current == 0) { 280 if (rstrm->last_frag) 281 return (FALSE); 282 if (! set_input_fragment(rstrm)) 283 return (FALSE); 284 continue; 285 } 286 current = (len < current) ? len : current; 287 if (! get_input_bytes(rstrm, addr, current)) 288 return (FALSE); 289 addr += current; 290 rstrm->fbtbc -= current; 291 len -= current; 292 } 293 return (TRUE); 294 } 295 296 static bool_t 297 xdrrec_putbytes(xdrs, addr, len) 298 XDR *xdrs; 299 const char *addr; 300 u_int len; 301 { 302 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 303 size_t current; 304 305 while (len > 0) { 306 current = (size_t)((u_long)rstrm->out_boundry - 307 (u_long)rstrm->out_finger); 308 current = (len < current) ? len : current; 309 memmove(rstrm->out_finger, addr, current); 310 rstrm->out_finger += current; 311 addr += current; 312 len -= current; 313 if (rstrm->out_finger == rstrm->out_boundry) { 314 rstrm->frag_sent = TRUE; 315 if (! flush_out(rstrm, FALSE)) 316 return (FALSE); 317 } 318 } 319 return (TRUE); 320 } 321 322 static u_int 323 xdrrec_getpos(xdrs) 324 XDR *xdrs; 325 { 326 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; 327 off_t pos; 328 329 pos = lseek((int)(u_long)rstrm->tcp_handle, (off_t)0, 1); 330 if (pos != -1) 331 switch (xdrs->x_op) { 332 333 case XDR_ENCODE: 334 pos += rstrm->out_finger - rstrm->out_base; 335 break; 336 337 case XDR_DECODE: 338 pos -= rstrm->in_boundry - rstrm->in_finger; 339 break; 340 341 default: 342 pos = (off_t) -1; 343 break; 344 } 345 return ((u_int) pos); 346 } 347 348 static bool_t 349 xdrrec_setpos(xdrs, pos) 350 XDR *xdrs; 351 u_int pos; 352 { 353 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; 354 u_int currpos = xdrrec_getpos(xdrs); 355 int delta = currpos - pos; 356 char *newpos; 357 358 if ((int)currpos != -1) 359 switch (xdrs->x_op) { 360 361 case XDR_ENCODE: 362 newpos = rstrm->out_finger - delta; 363 if ((newpos > (char *)(void *)(rstrm->frag_header)) && 364 (newpos < rstrm->out_boundry)) { 365 rstrm->out_finger = newpos; 366 return (TRUE); 367 } 368 break; 369 370 case XDR_DECODE: 371 newpos = rstrm->in_finger - delta; 372 if ((delta < (int)(rstrm->fbtbc)) && 373 (newpos <= rstrm->in_boundry) && 374 (newpos >= rstrm->in_base)) { 375 rstrm->in_finger = newpos; 376 rstrm->fbtbc -= delta; 377 return (TRUE); 378 } 379 break; 380 381 case XDR_FREE: 382 break; 383 } 384 return (FALSE); 385 } 386 387 static int32_t * 388 xdrrec_inline(xdrs, len) 389 XDR *xdrs; 390 u_int len; 391 { 392 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; 393 int32_t *buf = NULL; 394 395 switch (xdrs->x_op) { 396 397 case XDR_ENCODE: 398 if ((rstrm->out_finger + len) <= rstrm->out_boundry) { 399 buf = (int32_t *)(void *)rstrm->out_finger; 400 rstrm->out_finger += len; 401 } 402 break; 403 404 case XDR_DECODE: 405 if ((len <= rstrm->fbtbc) && 406 ((rstrm->in_finger + len) <= rstrm->in_boundry)) { 407 buf = (int32_t *)(void *)rstrm->in_finger; 408 rstrm->fbtbc -= len; 409 rstrm->in_finger += len; 410 } 411 break; 412 413 case XDR_FREE: 414 break; 415 } 416 return (buf); 417 } 418 419 static void 420 xdrrec_destroy(xdrs) 421 XDR *xdrs; 422 { 423 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; 424 425 mem_free(rstrm->the_buffer, 426 rstrm->sendsize + rstrm->recvsize + BYTES_PER_XDR_UNIT); 427 mem_free(rstrm, sizeof(RECSTREAM)); 428 } 429 430 431 /* 432 * Exported routines to manage xdr records 433 */ 434 435 /* 436 * Before reading (deserializing from the stream, one should always call 437 * this procedure to guarantee proper record alignment. 438 */ 439 bool_t 440 xdrrec_skiprecord(xdrs) 441 XDR *xdrs; 442 { 443 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 (FALSE); 448 rstrm->fbtbc = 0; 449 if ((! rstrm->last_frag) && (! set_input_fragment(rstrm))) 450 return (FALSE); 451 } 452 rstrm->last_frag = FALSE; 453 return (TRUE); 454 } 455 456 /* 457 * Look ahead fuction. 458 * Returns TRUE iff there is no more input in the buffer 459 * after consuming the rest of the current record. 460 */ 461 bool_t 462 xdrrec_eof(xdrs) 463 XDR *xdrs; 464 { 465 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 466 467 while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) { 468 if (! skip_input_bytes(rstrm, rstrm->fbtbc)) 469 return (TRUE); 470 rstrm->fbtbc = 0; 471 if ((! rstrm->last_frag) && (! set_input_fragment(rstrm))) 472 return (TRUE); 473 } 474 if (rstrm->in_finger == rstrm->in_boundry) 475 return (TRUE); 476 return (FALSE); 477 } 478 479 /* 480 * The client must tell the package when an end-of-record has occurred. 481 * The second paraemters tells whether the record should be flushed to the 482 * (output) tcp stream. (This let's the package support batched or 483 * pipelined procedure calls.) TRUE => immmediate flush to tcp connection. 484 */ 485 bool_t 486 xdrrec_endofrecord(xdrs, sendnow) 487 XDR *xdrs; 488 bool_t sendnow; 489 { 490 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 491 u_long len; /* fragment length */ 492 493 if (sendnow || rstrm->frag_sent || 494 ((u_long)rstrm->out_finger + sizeof(u_int32_t) >= 495 (u_long)rstrm->out_boundry)) { 496 rstrm->frag_sent = FALSE; 497 return (flush_out(rstrm, TRUE)); 498 } 499 len = (u_long)(rstrm->out_finger) - (u_long)(rstrm->frag_header) - 500 sizeof(u_int32_t); 501 *(rstrm->frag_header) = htonl((u_int32_t)len | LAST_FRAG); 502 rstrm->frag_header = (u_int32_t *)(void *)rstrm->out_finger; 503 rstrm->out_finger += sizeof(u_int32_t); 504 return (TRUE); 505 } 506 507 508 /* 509 * Internal useful routines 510 */ 511 static bool_t 512 flush_out(rstrm, eor) 513 RECSTREAM *rstrm; 514 bool_t eor; 515 { 516 u_int32_t eormask = (eor == TRUE) ? LAST_FRAG : 0; 517 u_int32_t len = (u_int32_t)((u_long)(rstrm->out_finger) - 518 (u_long)(rstrm->frag_header) - sizeof(u_int32_t)); 519 520 *(rstrm->frag_header) = htonl(len | eormask); 521 len = (u_int32_t)((u_long)(rstrm->out_finger) - 522 (u_long)(rstrm->out_base)); 523 if ((*(rstrm->writeit))(rstrm->tcp_handle, rstrm->out_base, (int)len) 524 != (int)len) 525 return (FALSE); 526 rstrm->frag_header = (u_int32_t *)(void *)rstrm->out_base; 527 rstrm->out_finger = (char *)rstrm->out_base + sizeof(u_int32_t); 528 return (TRUE); 529 } 530 531 static bool_t /* knows nothing about records! Only about input buffers */ 532 fill_input_buf(rstrm) 533 RECSTREAM *rstrm; 534 { 535 char *where; 536 u_int32_t i; 537 int len; 538 539 where = rstrm->in_base; 540 i = (u_int32_t)((u_long)rstrm->in_boundry % BYTES_PER_XDR_UNIT); 541 where += i; 542 len = (u_int32_t)(rstrm->in_size - i); 543 if ((len = (*(rstrm->readit))(rstrm->tcp_handle, where, len)) == -1) 544 return (FALSE); 545 rstrm->in_finger = where; 546 where += len; 547 rstrm->in_boundry = where; 548 return (TRUE); 549 } 550 551 static bool_t /* knows nothing about records! Only about input buffers */ 552 get_input_bytes(rstrm, addr, len) 553 RECSTREAM *rstrm; 554 char *addr; 555 int len; 556 { 557 size_t current; 558 559 while (len > 0) { 560 current = (size_t)((long)rstrm->in_boundry - 561 (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, (char *)(void *)&header, sizeof(header))) 583 return (FALSE); 584 header = ntohl(header); 585 rstrm->last_frag = ((header & LAST_FRAG) == 0) ? FALSE : TRUE; 586 /* 587 * Sanity check. Try not to accept wildly incorrect 588 * record sizes. Unfortunately, the only record size 589 * we can positively identify as being 'wildly incorrect' 590 * is zero. Ridiculously large record sizes may look wrong, 591 * but we don't have any way to be certain that they aren't 592 * what the client actually intended to send us. 593 */ 594 if ((header & (~LAST_FRAG)) == 0) 595 return(FALSE); 596 rstrm->fbtbc = header & (~LAST_FRAG); 597 return (TRUE); 598 } 599 600 static bool_t /* consumes input bytes; knows nothing about records! */ 601 skip_input_bytes(rstrm, cnt) 602 RECSTREAM *rstrm; 603 long cnt; 604 { 605 u_int32_t current; 606 607 while (cnt > 0) { 608 current = (size_t)((long)rstrm->in_boundry - 609 (long)rstrm->in_finger); 610 if (current == 0) { 611 if (! fill_input_buf(rstrm)) 612 return (FALSE); 613 continue; 614 } 615 current = (u_int32_t)((cnt < current) ? cnt : current); 616 rstrm->in_finger += current; 617 cnt -= current; 618 } 619 return (TRUE); 620 } 621 622 static u_int 623 fix_buf_size(s) 624 u_int s; 625 { 626 627 if (s < 100) 628 s = 4000; 629 return (RNDUP(s)); 630 } 631