1 /*- 2 * Copyright (c) 1997 Brian Somers <brian@Awfulhak.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $Id: deflate.c,v 1.13 1999/05/08 11:06:25 brian Exp $ 27 */ 28 29 #include <sys/types.h> 30 31 #include <stdio.h> 32 #include <stdlib.h> 33 #include <termios.h> 34 #include <zlib.h> 35 36 #include "defs.h" 37 #include "mbuf.h" 38 #include "log.h" 39 #include "timer.h" 40 #include "lqr.h" 41 #include "hdlc.h" 42 #include "fsm.h" 43 #include "lcp.h" 44 #include "ccp.h" 45 #include "deflate.h" 46 47 /* Our state */ 48 struct deflate_state { 49 u_short seqno; 50 int uncomp_rec; 51 int winsize; 52 z_stream cx; 53 }; 54 55 static char garbage[10]; 56 static u_char EMPTY_BLOCK[4] = { 0x00, 0x00, 0xff, 0xff }; 57 58 #define DEFLATE_CHUNK_LEN 1600 /* Allocate mbufs this size */ 59 60 static void 61 DeflateResetOutput(void *v) 62 { 63 struct deflate_state *state = (struct deflate_state *)v; 64 65 state->seqno = 0; 66 state->uncomp_rec = 0; 67 deflateReset(&state->cx); 68 log_Printf(LogCCP, "Deflate: Output channel reset\n"); 69 } 70 71 static struct mbuf * 72 DeflateOutput(void *v, struct ccp *ccp, struct link *l, int pri, u_short *proto, 73 struct mbuf *mp) 74 { 75 struct deflate_state *state = (struct deflate_state *)v; 76 u_char *wp, *rp; 77 int olen, ilen, len, res, flush; 78 struct mbuf *mo_head, *mo, *mi_head, *mi; 79 80 ilen = mbuf_Length(mp); 81 log_Printf(LogDEBUG, "DeflateOutput: Proto %02x (%d bytes)\n", *proto, ilen); 82 log_DumpBp(LogDEBUG, "DeflateOutput: Compress packet:", mp); 83 84 /* Stuff the protocol in front of the input */ 85 mi_head = mi = mbuf_Alloc(2, MB_CCPOUT); 86 mi->next = mp; 87 rp = MBUF_CTOP(mi); 88 if (*proto < 0x100) { /* Compress the protocol */ 89 rp[0] = *proto & 0377; 90 mi->cnt = 1; 91 } else { /* Don't compress the protocol */ 92 rp[0] = *proto >> 8; 93 rp[1] = *proto & 0377; 94 mi->cnt = 2; 95 } 96 97 /* Allocate the initial output mbuf */ 98 mo_head = mo = mbuf_Alloc(DEFLATE_CHUNK_LEN, MB_CCPOUT); 99 mo->cnt = 2; 100 wp = MBUF_CTOP(mo); 101 *wp++ = state->seqno >> 8; 102 *wp++ = state->seqno & 0377; 103 log_Printf(LogDEBUG, "DeflateOutput: Seq %d\n", state->seqno); 104 state->seqno++; 105 106 /* Set up the deflation context */ 107 state->cx.next_out = wp; 108 state->cx.avail_out = DEFLATE_CHUNK_LEN - 2; 109 state->cx.next_in = MBUF_CTOP(mi); 110 state->cx.avail_in = mi->cnt; 111 flush = Z_NO_FLUSH; 112 113 olen = 0; 114 while (1) { 115 if ((res = deflate(&state->cx, flush)) != Z_OK) { 116 if (res == Z_STREAM_END) 117 break; /* Done */ 118 log_Printf(LogWARN, "DeflateOutput: deflate returned %d (%s)\n", 119 res, state->cx.msg ? state->cx.msg : ""); 120 mbuf_Free(mo_head); 121 mbuf_FreeSeg(mi_head); 122 state->seqno--; 123 return mp; /* Our dictionary's probably dead now :-( */ 124 } 125 126 if (flush == Z_SYNC_FLUSH && state->cx.avail_out != 0) 127 break; 128 129 if (state->cx.avail_in == 0 && mi->next != NULL) { 130 mi = mi->next; 131 state->cx.next_in = MBUF_CTOP(mi); 132 state->cx.avail_in = mi->cnt; 133 if (mi->next == NULL) 134 flush = Z_SYNC_FLUSH; 135 } 136 137 if (state->cx.avail_out == 0) { 138 mo->next = mbuf_Alloc(DEFLATE_CHUNK_LEN, MB_CCPOUT); 139 olen += (mo->cnt = DEFLATE_CHUNK_LEN); 140 mo = mo->next; 141 mo->cnt = 0; 142 state->cx.next_out = MBUF_CTOP(mo); 143 state->cx.avail_out = DEFLATE_CHUNK_LEN; 144 } 145 } 146 147 olen += (mo->cnt = DEFLATE_CHUNK_LEN - state->cx.avail_out); 148 olen -= 4; /* exclude the trailing EMPTY_BLOCK */ 149 150 /* 151 * If the output packet (including seqno and excluding the EMPTY_BLOCK) 152 * got bigger, send the original. 153 */ 154 if (olen >= ilen) { 155 mbuf_Free(mo_head); 156 mbuf_FreeSeg(mi_head); 157 log_Printf(LogDEBUG, "DeflateOutput: %d => %d: Uncompressible (0x%04x)\n", 158 ilen, olen, *proto); 159 ccp->uncompout += ilen; 160 ccp->compout += ilen; /* We measure this stuff too */ 161 return mp; 162 } 163 164 mbuf_Free(mi_head); 165 166 /* 167 * Lose the last four bytes of our output. 168 * XXX: We should probably assert that these are the same as the 169 * contents of EMPTY_BLOCK. 170 */ 171 for (mo = mo_head, len = mo->cnt; len < olen; mo = mo->next, len += mo->cnt) 172 ; 173 mo->cnt -= len - olen; 174 if (mo->next != NULL) { 175 mbuf_Free(mo->next); 176 mo->next = NULL; 177 } 178 179 ccp->uncompout += ilen; 180 ccp->compout += olen; 181 182 log_Printf(LogDEBUG, "DeflateOutput: %d => %d bytes, proto 0x%04x\n", 183 ilen, olen, *proto); 184 185 *proto = ccp_Proto(ccp); 186 return mo_head; 187 } 188 189 static void 190 DeflateResetInput(void *v) 191 { 192 struct deflate_state *state = (struct deflate_state *)v; 193 194 state->seqno = 0; 195 state->uncomp_rec = 0; 196 inflateReset(&state->cx); 197 log_Printf(LogCCP, "Deflate: Input channel reset\n"); 198 } 199 200 static struct mbuf * 201 DeflateInput(void *v, struct ccp *ccp, u_short *proto, struct mbuf *mi) 202 { 203 struct deflate_state *state = (struct deflate_state *)v; 204 struct mbuf *mo, *mo_head, *mi_head; 205 u_char *wp; 206 int ilen, olen; 207 int seq, flush, res, first; 208 u_char hdr[2]; 209 210 log_DumpBp(LogDEBUG, "DeflateInput: Decompress packet:", mi); 211 mi_head = mi = mbuf_Read(mi, hdr, 2); 212 ilen = 2; 213 214 /* Check the sequence number. */ 215 seq = (hdr[0] << 8) + hdr[1]; 216 log_Printf(LogDEBUG, "DeflateInput: Seq %d\n", seq); 217 if (seq != state->seqno) { 218 if (seq <= state->uncomp_rec) 219 /* 220 * So the peer's started at zero again - fine ! If we're wrong, 221 * inflate() will fail. This is better than getting into a loop 222 * trying to get a ResetReq to a busy sender. 223 */ 224 state->seqno = seq; 225 else { 226 log_Printf(LogCCP, "DeflateInput: Seq error: Got %d, expected %d\n", 227 seq, state->seqno); 228 mbuf_Free(mi_head); 229 ccp_SendResetReq(&ccp->fsm); 230 return NULL; 231 } 232 } 233 state->seqno++; 234 state->uncomp_rec = 0; 235 236 /* Allocate an output mbuf */ 237 mo_head = mo = mbuf_Alloc(DEFLATE_CHUNK_LEN, MB_CCPIN); 238 239 /* Our proto starts with 0 if it's compressed */ 240 wp = MBUF_CTOP(mo); 241 wp[0] = '\0'; 242 243 /* 244 * We set avail_out to 1 initially so we can look at the first 245 * byte of the output and decide whether we have a compressed 246 * proto field. 247 */ 248 state->cx.next_in = MBUF_CTOP(mi); 249 state->cx.avail_in = mi->cnt; 250 state->cx.next_out = wp + 1; 251 state->cx.avail_out = 1; 252 ilen += mi->cnt; 253 254 flush = mi->next ? Z_NO_FLUSH : Z_SYNC_FLUSH; 255 first = 1; 256 olen = 0; 257 258 while (1) { 259 if ((res = inflate(&state->cx, flush)) != Z_OK) { 260 if (res == Z_STREAM_END) 261 break; /* Done */ 262 log_Printf(LogCCP, "DeflateInput: inflate returned %d (%s)\n", 263 res, state->cx.msg ? state->cx.msg : ""); 264 mbuf_Free(mo_head); 265 mbuf_Free(mi); 266 ccp_SendResetReq(&ccp->fsm); 267 return NULL; 268 } 269 270 if (flush == Z_SYNC_FLUSH && state->cx.avail_out != 0) 271 break; 272 273 if (state->cx.avail_in == 0 && mi && (mi = mbuf_FreeSeg(mi)) != NULL) { 274 /* underflow */ 275 state->cx.next_in = MBUF_CTOP(mi); 276 ilen += (state->cx.avail_in = mi->cnt); 277 if (mi->next == NULL) 278 flush = Z_SYNC_FLUSH; 279 } 280 281 if (state->cx.avail_out == 0) { 282 /* overflow */ 283 if (first) { 284 if (!(wp[1] & 1)) { 285 /* 2 byte proto, shuffle it back in output */ 286 wp[0] = wp[1]; 287 state->cx.next_out--; 288 state->cx.avail_out = DEFLATE_CHUNK_LEN-1; 289 } else 290 state->cx.avail_out = DEFLATE_CHUNK_LEN-2; 291 first = 0; 292 } else { 293 olen += (mo->cnt = DEFLATE_CHUNK_LEN); 294 mo->next = mbuf_Alloc(DEFLATE_CHUNK_LEN, MB_CCPIN); 295 mo = mo->next; 296 state->cx.next_out = MBUF_CTOP(mo); 297 state->cx.avail_out = DEFLATE_CHUNK_LEN; 298 } 299 } 300 } 301 302 if (mi != NULL) 303 mbuf_Free(mi); 304 305 if (first) { 306 log_Printf(LogCCP, "DeflateInput: Length error\n"); 307 mbuf_Free(mo_head); 308 ccp_SendResetReq(&ccp->fsm); 309 return NULL; 310 } 311 312 olen += (mo->cnt = DEFLATE_CHUNK_LEN - state->cx.avail_out); 313 314 *proto = ((u_short)wp[0] << 8) | wp[1]; 315 mo_head->offset += 2; 316 mo_head->cnt -= 2; 317 olen -= 2; 318 319 ccp->compin += ilen; 320 ccp->uncompin += olen; 321 322 log_Printf(LogDEBUG, "DeflateInput: %d => %d bytes, proto 0x%04x\n", 323 ilen, olen, *proto); 324 325 /* 326 * Simulate an EMPTY_BLOCK so that our dictionary stays in sync. 327 * The peer will have silently removed this! 328 */ 329 state->cx.next_out = garbage; 330 state->cx.avail_out = sizeof garbage; 331 state->cx.next_in = EMPTY_BLOCK; 332 state->cx.avail_in = sizeof EMPTY_BLOCK; 333 inflate(&state->cx, Z_SYNC_FLUSH); 334 335 return mo_head; 336 } 337 338 static void 339 DeflateDictSetup(void *v, struct ccp *ccp, u_short proto, struct mbuf *mi) 340 { 341 struct deflate_state *state = (struct deflate_state *)v; 342 int res, flush, expect_error; 343 u_char *rp; 344 struct mbuf *mi_head; 345 short len; 346 347 log_Printf(LogDEBUG, "DeflateDictSetup: Got seq %d\n", state->seqno); 348 349 /* 350 * Stuff an ``uncompressed data'' block header followed by the 351 * protocol in front of the input 352 */ 353 mi_head = mbuf_Alloc(7, MB_CCPOUT); 354 mi_head->next = mi; 355 len = mbuf_Length(mi); 356 mi = mi_head; 357 rp = MBUF_CTOP(mi); 358 if (proto < 0x100) { /* Compress the protocol */ 359 rp[5] = proto & 0377; 360 mi->cnt = 6; 361 len++; 362 } else { /* Don't compress the protocol */ 363 rp[5] = proto >> 8; 364 rp[6] = proto & 0377; 365 mi->cnt = 7; 366 len += 2; 367 } 368 rp[0] = 0x80; /* BITS: 100xxxxx */ 369 rp[1] = len & 0377; /* The length */ 370 rp[2] = len >> 8; 371 rp[3] = (~len) & 0377; /* One's compliment of the length */ 372 rp[4] = (~len) >> 8; 373 374 state->cx.next_in = rp; 375 state->cx.avail_in = mi->cnt; 376 state->cx.next_out = garbage; 377 state->cx.avail_out = sizeof garbage; 378 flush = Z_NO_FLUSH; 379 expect_error = 0; 380 381 while (1) { 382 if ((res = inflate(&state->cx, flush)) != Z_OK) { 383 if (res == Z_STREAM_END) 384 break; /* Done */ 385 if (expect_error && res == Z_BUF_ERROR) 386 break; 387 log_Printf(LogCCP, "DeflateDictSetup: inflate returned %d (%s)\n", 388 res, state->cx.msg ? state->cx.msg : ""); 389 log_Printf(LogCCP, "DeflateDictSetup: avail_in %d, avail_out %d\n", 390 state->cx.avail_in, state->cx.avail_out); 391 ccp_SendResetReq(&ccp->fsm); 392 mbuf_FreeSeg(mi_head); /* lose our allocated ``head'' buf */ 393 return; 394 } 395 396 if (flush == Z_SYNC_FLUSH && state->cx.avail_out != 0) 397 break; 398 399 if (state->cx.avail_in == 0 && mi && (mi = mi->next) != NULL) { 400 /* underflow */ 401 state->cx.next_in = MBUF_CTOP(mi); 402 state->cx.avail_in = mi->cnt; 403 if (mi->next == NULL) 404 flush = Z_SYNC_FLUSH; 405 } 406 407 if (state->cx.avail_out == 0) { 408 if (state->cx.avail_in == 0) 409 /* 410 * This seems to be a bug in libz ! If inflate() finished 411 * with 0 avail_in and 0 avail_out *and* this is the end of 412 * our input *and* inflate() *has* actually written all the 413 * output it's going to, it *doesn't* return Z_STREAM_END ! 414 * When we subsequently call it with no more input, it gives 415 * us Z_BUF_ERROR :-( It seems pretty safe to ignore this 416 * error (the dictionary seems to stay in sync). In the worst 417 * case, we'll drop the next compressed packet and do a 418 * CcpReset() then. 419 */ 420 expect_error = 1; 421 /* overflow */ 422 state->cx.next_out = garbage; 423 state->cx.avail_out = sizeof garbage; 424 } 425 } 426 427 ccp->compin += len; 428 ccp->uncompin += len; 429 430 state->seqno++; 431 state->uncomp_rec++; 432 mbuf_FreeSeg(mi_head); /* lose our allocated ``head'' buf */ 433 } 434 435 static const char * 436 DeflateDispOpts(struct lcp_opt *o) 437 { 438 static char disp[7]; /* Must be used immediately */ 439 440 sprintf(disp, "win %d", (o->data[0]>>4) + 8); 441 return disp; 442 } 443 444 static void 445 DeflateInitOptsOutput(struct lcp_opt *o, const struct ccp_config *cfg) 446 { 447 o->len = 4; 448 o->data[0] = ((cfg->deflate.out.winsize - 8) << 4) + 8; 449 o->data[1] = '\0'; 450 } 451 452 static int 453 DeflateSetOptsOutput(struct lcp_opt *o) 454 { 455 if (o->len != 4 || (o->data[0] & 15) != 8 || o->data[1] != '\0') 456 return MODE_REJ; 457 458 if ((o->data[0] >> 4) + 8 > 15) { 459 o->data[0] = ((15 - 8) << 4) + 8; 460 return MODE_NAK; 461 } 462 463 return MODE_ACK; 464 } 465 466 static int 467 DeflateSetOptsInput(struct lcp_opt *o, const struct ccp_config *cfg) 468 { 469 int want; 470 471 if (o->len != 4 || (o->data[0] & 15) != 8 || o->data[1] != '\0') 472 return MODE_REJ; 473 474 want = (o->data[0] >> 4) + 8; 475 if (cfg->deflate.in.winsize == 0) { 476 if (want < 8 || want > 15) { 477 o->data[0] = ((15 - 8) << 4) + 8; 478 } 479 } else if (want != cfg->deflate.in.winsize) { 480 o->data[0] = ((cfg->deflate.in.winsize - 8) << 4) + 8; 481 return MODE_NAK; 482 } 483 484 return MODE_ACK; 485 } 486 487 static void * 488 DeflateInitInput(struct lcp_opt *o) 489 { 490 struct deflate_state *state; 491 492 state = (struct deflate_state *)malloc(sizeof(struct deflate_state)); 493 if (state != NULL) { 494 state->winsize = (o->data[0] >> 4) + 8; 495 state->cx.zalloc = NULL; 496 state->cx.opaque = NULL; 497 state->cx.zfree = NULL; 498 state->cx.next_out = NULL; 499 if (inflateInit2(&state->cx, -state->winsize) == Z_OK) 500 DeflateResetInput(state); 501 else { 502 free(state); 503 state = NULL; 504 } 505 } 506 507 return state; 508 } 509 510 static void * 511 DeflateInitOutput(struct lcp_opt *o) 512 { 513 struct deflate_state *state; 514 515 state = (struct deflate_state *)malloc(sizeof(struct deflate_state)); 516 if (state != NULL) { 517 state->winsize = (o->data[0] >> 4) + 8; 518 state->cx.zalloc = NULL; 519 state->cx.opaque = NULL; 520 state->cx.zfree = NULL; 521 state->cx.next_in = NULL; 522 if (deflateInit2(&state->cx, Z_DEFAULT_COMPRESSION, 8, 523 -state->winsize, 8, Z_DEFAULT_STRATEGY) == Z_OK) 524 DeflateResetOutput(state); 525 else { 526 free(state); 527 state = NULL; 528 } 529 } 530 531 return state; 532 } 533 534 static void 535 DeflateTermInput(void *v) 536 { 537 struct deflate_state *state = (struct deflate_state *)v; 538 539 inflateEnd(&state->cx); 540 free(state); 541 } 542 543 static void 544 DeflateTermOutput(void *v) 545 { 546 struct deflate_state *state = (struct deflate_state *)v; 547 548 deflateEnd(&state->cx); 549 free(state); 550 } 551 552 const struct ccp_algorithm PppdDeflateAlgorithm = { 553 TY_PPPD_DEFLATE, /* pppd (wrongly) expects this ``type'' field */ 554 CCP_NEG_DEFLATE24, 555 DeflateDispOpts, 556 { 557 DeflateSetOptsInput, 558 DeflateInitInput, 559 DeflateTermInput, 560 DeflateResetInput, 561 DeflateInput, 562 DeflateDictSetup 563 }, 564 { 565 DeflateInitOptsOutput, 566 DeflateSetOptsOutput, 567 DeflateInitOutput, 568 DeflateTermOutput, 569 DeflateResetOutput, 570 DeflateOutput 571 }, 572 }; 573 574 const struct ccp_algorithm DeflateAlgorithm = { 575 TY_DEFLATE, /* rfc 1979 */ 576 CCP_NEG_DEFLATE, 577 DeflateDispOpts, 578 { 579 DeflateSetOptsInput, 580 DeflateInitInput, 581 DeflateTermInput, 582 DeflateResetInput, 583 DeflateInput, 584 DeflateDictSetup 585 }, 586 { 587 DeflateInitOptsOutput, 588 DeflateSetOptsOutput, 589 DeflateInitOutput, 590 DeflateTermOutput, 591 DeflateResetOutput, 592 DeflateOutput 593 }, 594 }; 595