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 /*static char *sccsid = "from: @(#)xdr_rec.c 1.21 87/08/11 Copyr 1984 Sun Micro";*/ 35 /*static char *sccsid = "from: @(#)xdr_rec.c 2.2 88/08/01 4.0 RPCSRC";*/ 36 static char *rcsid = "$FreeBSD$"; 37 #endif 38 39 /* 40 * xdr_rec.c, Implements TCP/IP based XDR streams with a "record marking" 41 * layer above tcp (for rpc's use). 42 * 43 * Copyright (C) 1984, Sun Microsystems, Inc. 44 * 45 * These routines interface XDRSTREAMS to a tcp/ip connection. 46 * There is a record marking layer between the xdr stream 47 * and the tcp transport level. A record is composed on one or more 48 * record fragments. A record fragment is a thirty-two bit header followed 49 * by n bytes of data, where n is contained in the header. The header 50 * is represented as a htonl(u_long). Thegh order bit encodes 51 * whether or not the fragment is the last fragment of the record 52 * (1 => fragment is last, 0 => more fragments to follow. 53 * The other 31 bits encode the byte length of the fragment. 54 */ 55 56 #include "namespace.h" 57 #include <sys/types.h> 58 59 #include <netinet/in.h> 60 61 #include <err.h> 62 #include <stdio.h> 63 #include <stdlib.h> 64 #include <string.h> 65 66 #include <rpc/types.h> 67 #include <rpc/xdr.h> 68 #include "un-namespace.h" 69 70 static bool_t xdrrec_getlong __P((XDR *, long *)); 71 static bool_t xdrrec_putlong __P((XDR *, const long *)); 72 static bool_t xdrrec_getbytes __P((XDR *, char *, u_int)); 73 74 static bool_t xdrrec_putbytes __P((XDR *, const char *, u_int)); 75 static u_int xdrrec_getpos __P((XDR *)); 76 static bool_t xdrrec_setpos __P((XDR *, u_int)); 77 static int32_t *xdrrec_inline __P((XDR *, u_int)); 78 static void xdrrec_destroy __P((XDR *)); 79 80 static const struct xdr_ops xdrrec_ops = { 81 xdrrec_getlong, 82 xdrrec_putlong, 83 xdrrec_getbytes, 84 xdrrec_putbytes, 85 xdrrec_getpos, 86 xdrrec_setpos, 87 xdrrec_inline, 88 xdrrec_destroy 89 }; 90 91 /* 92 * A record is composed of one or more record fragments. 93 * A record fragment is a two-byte header followed by zero to 94 * 2**32-1 bytes. The header is treated as a long unsigned and is 95 * encode/decoded to the network via htonl/ntohl. The low order 31 bits 96 * are a byte count of the fragment. The highest order bit is a boolean: 97 * 1 => this fragment is the last fragment of the record, 98 * 0 => this fragment is followed by more fragment(s). 99 * 100 * The fragment/record machinery is not general; it is constructed to 101 * meet the needs of xdr and rpc based on tcp. 102 */ 103 104 #define LAST_FRAG ((u_int32_t)(1 << 31)) 105 106 typedef struct rec_strm { 107 char *tcp_handle; 108 char *the_buffer; 109 /* 110 * out-goung bits 111 */ 112 int (*writeit) __P((char *, char *, int)); 113 char *out_base; /* output buffer (points to frag header) */ 114 char *out_finger; /* next output position */ 115 char *out_boundry; /* data cannot up to this address */ 116 u_int32_t *frag_header; /* beginning of curren fragment */ 117 bool_t frag_sent; /* true if buffer sent in middle of record */ 118 /* 119 * in-coming bits 120 */ 121 int (*readit) __P((char *, char *, int)); 122 u_long in_size; /* fixed size of the input buffer */ 123 char *in_base; 124 char *in_finger; /* location of next byte to be had */ 125 char *in_boundry; /* can read up to this location */ 126 long fbtbc; /* fragment bytes to be consumed */ 127 bool_t last_frag; 128 u_int sendsize; 129 u_int recvsize; 130 } RECSTREAM; 131 132 static u_int fix_buf_size __P((u_int)); 133 static bool_t flush_out __P((RECSTREAM *, bool_t)); 134 static bool_t fill_input_buf __P((RECSTREAM *)); 135 static bool_t get_input_bytes __P((RECSTREAM *, char *, int)); 136 static bool_t set_input_fragment __P((RECSTREAM *)); 137 static bool_t skip_input_bytes __P((RECSTREAM *, long)); 138 139 140 /* 141 * Create an xdr handle for xdrrec 142 * xdrrec_create fills in xdrs. Sendsize and recvsize are 143 * send and recv buffer sizes (0 => use default). 144 * tcp_handle is an opaque handle that is passed as the first parameter to 145 * the procedures readit and writeit. Readit and writeit are read and 146 * write respectively. They are like the system 147 * calls expect that they take an opaque handle rather than an fd. 148 */ 149 void 150 xdrrec_create(xdrs, sendsize, recvsize, tcp_handle, readit, writeit) 151 XDR *xdrs; 152 u_int sendsize; 153 u_int recvsize; 154 char *tcp_handle; 155 /* like read, but pass it a tcp_handle, not sock */ 156 int (*readit) __P((char *, char *, int)); 157 /* like write, but pass it a tcp_handle, not sock */ 158 int (*writeit) __P((char *, char *, int)); 159 { 160 RECSTREAM *rstrm = mem_alloc(sizeof(RECSTREAM)); 161 162 if (rstrm == NULL) { 163 warnx("xdrrec_create: out of memory"); 164 /* 165 * This is bad. Should rework xdrrec_create to 166 * return a handle, and in this case return NULL 167 */ 168 return; 169 } 170 /* 171 * adjust sizes and allocate buffer quad byte aligned 172 */ 173 rstrm->sendsize = sendsize = fix_buf_size(sendsize); 174 rstrm->recvsize = recvsize = fix_buf_size(recvsize); 175 rstrm->the_buffer = mem_alloc(sendsize + recvsize + BYTES_PER_XDR_UNIT); 176 if (rstrm->the_buffer == NULL) { 177 warnx("xdrrec_create: out of memory"); 178 return; 179 } 180 for (rstrm->out_base = rstrm->the_buffer; 181 (u_long)rstrm->out_base % BYTES_PER_XDR_UNIT != 0; 182 rstrm->out_base++); 183 rstrm->in_base = rstrm->out_base + sendsize; 184 /* 185 * now the rest ... 186 */ 187 xdrs->x_ops = &xdrrec_ops; 188 xdrs->x_private = rstrm; 189 rstrm->tcp_handle = tcp_handle; 190 rstrm->readit = readit; 191 rstrm->writeit = writeit; 192 rstrm->out_finger = rstrm->out_boundry = rstrm->out_base; 193 rstrm->frag_header = (u_int32_t *)(void *)rstrm->out_base; 194 rstrm->out_finger += sizeof(u_int32_t); 195 rstrm->out_boundry += sendsize; 196 rstrm->frag_sent = FALSE; 197 rstrm->in_size = recvsize; 198 rstrm->in_boundry = rstrm->in_base; 199 rstrm->in_finger = (rstrm->in_boundry += recvsize); 200 rstrm->fbtbc = 0; 201 rstrm->last_frag = TRUE; 202 } 203 204 205 /* 206 * The reoutines defined below are the xdr ops which will go into the 207 * xdr handle filled in by xdrrec_create. 208 */ 209 210 static bool_t 211 xdrrec_getlong(xdrs, lp) 212 XDR *xdrs; 213 long *lp; 214 { 215 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 216 int32_t *buflp = (int32_t *)(void *)(rstrm->in_finger); 217 int32_t mylong; 218 219 /* first try the inline, fast case */ 220 if ((rstrm->fbtbc >= sizeof(int32_t)) && 221 (((long)rstrm->in_boundry - (long)buflp) >= sizeof(int32_t))) { 222 *lp = (long)ntohl((u_int32_t)(*buflp)); 223 rstrm->fbtbc -= sizeof(int32_t); 224 rstrm->in_finger += sizeof(int32_t); 225 } else { 226 if (! xdrrec_getbytes(xdrs, (char *)(void *)&mylong, 227 sizeof(int32_t))) 228 return (FALSE); 229 *lp = (long)ntohl((u_int32_t)mylong); 230 } 231 return (TRUE); 232 } 233 234 static bool_t 235 xdrrec_putlong(xdrs, lp) 236 XDR *xdrs; 237 const long *lp; 238 { 239 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 240 int32_t *dest_lp = ((int32_t *)(void *)(rstrm->out_finger)); 241 242 if ((rstrm->out_finger += sizeof(int32_t)) > rstrm->out_boundry) { 243 /* 244 * this case should almost never happen so the code is 245 * inefficient 246 */ 247 rstrm->out_finger -= sizeof(int32_t); 248 rstrm->frag_sent = TRUE; 249 if (! flush_out(rstrm, FALSE)) 250 return (FALSE); 251 dest_lp = ((int32_t *)(void *)(rstrm->out_finger)); 252 rstrm->out_finger += sizeof(int32_t); 253 } 254 *dest_lp = (int32_t)htonl((u_int32_t)(*lp)); 255 return (TRUE); 256 } 257 258 static bool_t /* must manage buffers, fragments, and records */ 259 xdrrec_getbytes(xdrs, addr, len) 260 XDR *xdrs; 261 char *addr; 262 u_int len; 263 { 264 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 265 int current; 266 267 while (len > 0) { 268 current = (int)rstrm->fbtbc; 269 if (current == 0) { 270 if (rstrm->last_frag) 271 return (FALSE); 272 if (! set_input_fragment(rstrm)) 273 return (FALSE); 274 continue; 275 } 276 current = (len < current) ? len : current; 277 if (! get_input_bytes(rstrm, addr, current)) 278 return (FALSE); 279 addr += current; 280 rstrm->fbtbc -= current; 281 len -= current; 282 } 283 return (TRUE); 284 } 285 286 static bool_t 287 xdrrec_putbytes(xdrs, addr, len) 288 XDR *xdrs; 289 const char *addr; 290 u_int len; 291 { 292 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 293 size_t current; 294 295 while (len > 0) { 296 current = (size_t)((u_long)rstrm->out_boundry - 297 (u_long)rstrm->out_finger); 298 current = (len < current) ? len : current; 299 memmove(rstrm->out_finger, addr, current); 300 rstrm->out_finger += current; 301 addr += current; 302 len -= current; 303 if (rstrm->out_finger == rstrm->out_boundry) { 304 rstrm->frag_sent = TRUE; 305 if (! flush_out(rstrm, FALSE)) 306 return (FALSE); 307 } 308 } 309 return (TRUE); 310 } 311 312 static u_int 313 xdrrec_getpos(xdrs) 314 XDR *xdrs; 315 { 316 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; 317 off_t pos; 318 319 pos = lseek((int)(u_long)rstrm->tcp_handle, (off_t)0, 1); 320 if (pos != -1) 321 switch (xdrs->x_op) { 322 323 case XDR_ENCODE: 324 pos += rstrm->out_finger - rstrm->out_base; 325 break; 326 327 case XDR_DECODE: 328 pos -= rstrm->in_boundry - rstrm->in_finger; 329 break; 330 331 default: 332 pos = (off_t) -1; 333 break; 334 } 335 return ((u_int) pos); 336 } 337 338 static bool_t 339 xdrrec_setpos(xdrs, pos) 340 XDR *xdrs; 341 u_int pos; 342 { 343 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; 344 u_int currpos = xdrrec_getpos(xdrs); 345 int delta = currpos - pos; 346 char *newpos; 347 348 if ((int)currpos != -1) 349 switch (xdrs->x_op) { 350 351 case XDR_ENCODE: 352 newpos = rstrm->out_finger - delta; 353 if ((newpos > (char *)(void *)(rstrm->frag_header)) && 354 (newpos < rstrm->out_boundry)) { 355 rstrm->out_finger = newpos; 356 return (TRUE); 357 } 358 break; 359 360 case XDR_DECODE: 361 newpos = rstrm->in_finger - delta; 362 if ((delta < (int)(rstrm->fbtbc)) && 363 (newpos <= rstrm->in_boundry) && 364 (newpos >= rstrm->in_base)) { 365 rstrm->in_finger = newpos; 366 rstrm->fbtbc -= delta; 367 return (TRUE); 368 } 369 break; 370 371 case XDR_FREE: 372 break; 373 } 374 return (FALSE); 375 } 376 377 static int32_t * 378 xdrrec_inline(xdrs, len) 379 XDR *xdrs; 380 u_int len; 381 { 382 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; 383 int32_t *buf = NULL; 384 385 switch (xdrs->x_op) { 386 387 case XDR_ENCODE: 388 if ((rstrm->out_finger + len) <= rstrm->out_boundry) { 389 buf = (int32_t *)(void *)rstrm->out_finger; 390 rstrm->out_finger += len; 391 } 392 break; 393 394 case XDR_DECODE: 395 if ((len <= rstrm->fbtbc) && 396 ((rstrm->in_finger + len) <= rstrm->in_boundry)) { 397 buf = (int32_t *)(void *)rstrm->in_finger; 398 rstrm->fbtbc -= len; 399 rstrm->in_finger += len; 400 } 401 break; 402 403 case XDR_FREE: 404 break; 405 } 406 return (buf); 407 } 408 409 static void 410 xdrrec_destroy(xdrs) 411 XDR *xdrs; 412 { 413 RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; 414 415 mem_free(rstrm->the_buffer, 416 rstrm->sendsize + rstrm->recvsize + BYTES_PER_XDR_UNIT); 417 mem_free(rstrm, sizeof(RECSTREAM)); 418 } 419 420 421 /* 422 * Exported routines to manage xdr records 423 */ 424 425 /* 426 * Before reading (deserializing from the stream, one should always call 427 * this procedure to guarantee proper record alignment. 428 */ 429 bool_t 430 xdrrec_skiprecord(xdrs) 431 XDR *xdrs; 432 { 433 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 434 435 while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) { 436 if (! skip_input_bytes(rstrm, rstrm->fbtbc)) 437 return (FALSE); 438 rstrm->fbtbc = 0; 439 if ((! rstrm->last_frag) && (! set_input_fragment(rstrm))) 440 return (FALSE); 441 } 442 rstrm->last_frag = FALSE; 443 return (TRUE); 444 } 445 446 /* 447 * Look ahead function. 448 * Returns TRUE iff there is no more input in the buffer 449 * after consuming the rest of the current record. 450 */ 451 bool_t 452 xdrrec_eof(xdrs) 453 XDR *xdrs; 454 { 455 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 456 457 while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) { 458 if (! skip_input_bytes(rstrm, rstrm->fbtbc)) 459 return (TRUE); 460 rstrm->fbtbc = 0; 461 if ((! rstrm->last_frag) && (! set_input_fragment(rstrm))) 462 return (TRUE); 463 } 464 if (rstrm->in_finger == rstrm->in_boundry) 465 return (TRUE); 466 return (FALSE); 467 } 468 469 /* 470 * The client must tell the package when an end-of-record has occurred. 471 * The second paraemters tells whether the record should be flushed to the 472 * (output) tcp stream. (This let's the package support batched or 473 * pipelined procedure calls.) TRUE => immmediate flush to tcp connection. 474 */ 475 bool_t 476 xdrrec_endofrecord(xdrs, sendnow) 477 XDR *xdrs; 478 bool_t sendnow; 479 { 480 RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); 481 u_long len; /* fragment length */ 482 483 if (sendnow || rstrm->frag_sent || 484 ((u_long)rstrm->out_finger + sizeof(u_int32_t) >= 485 (u_long)rstrm->out_boundry)) { 486 rstrm->frag_sent = FALSE; 487 return (flush_out(rstrm, TRUE)); 488 } 489 len = (u_long)(rstrm->out_finger) - (u_long)(rstrm->frag_header) - 490 sizeof(u_int32_t); 491 *(rstrm->frag_header) = htonl((u_int32_t)len | LAST_FRAG); 492 rstrm->frag_header = (u_int32_t *)(void *)rstrm->out_finger; 493 rstrm->out_finger += sizeof(u_int32_t); 494 return (TRUE); 495 } 496 497 498 /* 499 * Internal useful routines 500 */ 501 static bool_t 502 flush_out(rstrm, eor) 503 RECSTREAM *rstrm; 504 bool_t eor; 505 { 506 u_int32_t eormask = (eor == TRUE) ? LAST_FRAG : 0; 507 u_int32_t len = (u_int32_t)((u_long)(rstrm->out_finger) - 508 (u_long)(rstrm->frag_header) - sizeof(u_int32_t)); 509 510 *(rstrm->frag_header) = htonl(len | eormask); 511 len = (u_int32_t)((u_long)(rstrm->out_finger) - 512 (u_long)(rstrm->out_base)); 513 if ((*(rstrm->writeit))(rstrm->tcp_handle, rstrm->out_base, (int)len) 514 != (int)len) 515 return (FALSE); 516 rstrm->frag_header = (u_int32_t *)(void *)rstrm->out_base; 517 rstrm->out_finger = (char *)rstrm->out_base + sizeof(u_int32_t); 518 return (TRUE); 519 } 520 521 static bool_t /* knows nothing about records! Only about input buffers */ 522 fill_input_buf(rstrm) 523 RECSTREAM *rstrm; 524 { 525 char *where; 526 u_int32_t i; 527 int len; 528 529 where = rstrm->in_base; 530 i = (u_int32_t)((u_long)rstrm->in_boundry % BYTES_PER_XDR_UNIT); 531 where += i; 532 len = (u_int32_t)(rstrm->in_size - i); 533 if ((len = (*(rstrm->readit))(rstrm->tcp_handle, where, len)) == -1) 534 return (FALSE); 535 rstrm->in_finger = where; 536 where += len; 537 rstrm->in_boundry = where; 538 return (TRUE); 539 } 540 541 static bool_t /* knows nothing about records! Only about input buffers */ 542 get_input_bytes(rstrm, addr, len) 543 RECSTREAM *rstrm; 544 char *addr; 545 int len; 546 { 547 size_t current; 548 549 while (len > 0) { 550 current = (size_t)((long)rstrm->in_boundry - 551 (long)rstrm->in_finger); 552 if (current == 0) { 553 if (! fill_input_buf(rstrm)) 554 return (FALSE); 555 continue; 556 } 557 current = (len < current) ? len : current; 558 memmove(addr, rstrm->in_finger, current); 559 rstrm->in_finger += current; 560 addr += current; 561 len -= current; 562 } 563 return (TRUE); 564 } 565 566 static bool_t /* next two bytes of the input stream are treated as a header */ 567 set_input_fragment(rstrm) 568 RECSTREAM *rstrm; 569 { 570 u_int32_t header; 571 572 if (! get_input_bytes(rstrm, (char *)(void *)&header, sizeof(header))) 573 return (FALSE); 574 header = ntohl(header); 575 rstrm->last_frag = ((header & LAST_FRAG) == 0) ? FALSE : TRUE; 576 /* 577 * Sanity check. Try not to accept wildly incorrect 578 * record sizes. Unfortunately, the only record size 579 * we can positively identify as being 'wildly incorrect' 580 * is zero. Ridiculously large record sizes may look wrong, 581 * but we don't have any way to be certain that they aren't 582 * what the client actually intended to send us. 583 */ 584 if (header == 0) 585 return(FALSE); 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 long cnt; 594 { 595 u_int32_t current; 596 597 while (cnt > 0) { 598 current = (size_t)((long)rstrm->in_boundry - 599 (long)rstrm->in_finger); 600 if (current == 0) { 601 if (! fill_input_buf(rstrm)) 602 return (FALSE); 603 continue; 604 } 605 current = (u_int32_t)((cnt < current) ? cnt : current); 606 rstrm->in_finger += current; 607 cnt -= current; 608 } 609 return (TRUE); 610 } 611 612 static u_int 613 fix_buf_size(s) 614 u_int s; 615 { 616 617 if (s < 100) 618 s = 4000; 619 return (RNDUP(s)); 620 } 621