lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame] | 1 | /* |
| 2 | * ppp_deflate.c - interface the zlib procedures for Deflate compression |
| 3 | * and decompression (as used by gzip) to the PPP code. |
| 4 | * This version is for use with STREAMS under SunOS 4.x, Solaris 2, |
| 5 | * SVR4, OSF/1 and AIX 4.x. |
| 6 | * |
| 7 | * Copyright (c) 1994 Paul Mackerras. All rights reserved. |
| 8 | * |
| 9 | * Redistribution and use in source and binary forms, with or without |
| 10 | * modification, are permitted provided that the following conditions |
| 11 | * are met: |
| 12 | * |
| 13 | * 1. Redistributions of source code must retain the above copyright |
| 14 | * notice, this list of conditions and the following disclaimer. |
| 15 | * |
| 16 | * 2. Redistributions in binary form must reproduce the above copyright |
| 17 | * notice, this list of conditions and the following disclaimer in |
| 18 | * the documentation and/or other materials provided with the |
| 19 | * distribution. |
| 20 | * |
| 21 | * 3. The name(s) of the authors of this software must not be used to |
| 22 | * endorse or promote products derived from this software without |
| 23 | * prior written permission. |
| 24 | * |
| 25 | * 4. Redistributions of any form whatsoever must retain the following |
| 26 | * acknowledgment: |
| 27 | * "This product includes software developed by Paul Mackerras |
| 28 | * <paulus@samba.org>". |
| 29 | * |
| 30 | * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO |
| 31 | * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY |
| 32 | * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY |
| 33 | * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
| 34 | * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN |
| 35 | * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING |
| 36 | * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
| 37 | * |
xf.li | 8402749 | 2024-04-09 00:17:51 -0700 | [diff] [blame^] | 38 | * $Id: deflate.c,v 1.12 2004/01/17 05:47:55 carlsonj Exp $ |
lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame] | 39 | */ |
| 40 | |
| 41 | #ifdef AIX4 |
| 42 | #include <net/net_globals.h> |
| 43 | #endif |
| 44 | #include <sys/param.h> |
| 45 | #include <sys/types.h> |
| 46 | #include <sys/stream.h> |
| 47 | #include <net/ppp_defs.h> |
| 48 | #include "ppp_mod.h" |
| 49 | |
| 50 | #define PACKETPTR mblk_t * |
| 51 | #include <net/ppp-comp.h> |
| 52 | |
| 53 | #ifdef __osf__ |
| 54 | #include "zlib.h" |
| 55 | #else |
| 56 | #include "../common/zlib.h" |
| 57 | #endif |
| 58 | |
| 59 | #ifdef SOL2 |
| 60 | #include <sys/sunddi.h> |
| 61 | #endif |
| 62 | |
| 63 | #if DO_DEFLATE |
| 64 | |
| 65 | #define DEFLATE_DEBUG 1 |
| 66 | |
| 67 | /* |
| 68 | * State for a Deflate (de)compressor. |
| 69 | */ |
| 70 | struct deflate_state { |
| 71 | int seqno; |
| 72 | int w_size; |
| 73 | int unit; |
| 74 | int hdrlen; |
| 75 | int mru; |
| 76 | int debug; |
| 77 | z_stream strm; |
| 78 | struct compstat stats; |
| 79 | }; |
| 80 | |
| 81 | #define DEFLATE_OVHD 2 /* Deflate overhead/packet */ |
| 82 | |
xf.li | 8402749 | 2024-04-09 00:17:51 -0700 | [diff] [blame^] | 83 | static void *z_alloc(void *, u_int items, u_int size); |
| 84 | static void *z_alloc_init(void *, u_int items, u_int size); |
| 85 | static void z_free(void *, void *ptr); |
| 86 | static void *z_comp_alloc(u_char *options, int opt_len); |
| 87 | static void *z_decomp_alloc(u_char *options, int opt_len); |
| 88 | static void z_comp_free(void *state); |
| 89 | static void z_decomp_free(void *state); |
| 90 | static int z_comp_init(void *state, u_char *options, int opt_len, |
| 91 | int unit, int hdrlen, int debug); |
| 92 | static int z_decomp_init(void *state, u_char *options, int opt_len, |
| 93 | int unit, int hdrlen, int mru, int debug); |
| 94 | static int z_compress(void *state, mblk_t **mret, |
| 95 | mblk_t *mp, int slen, int maxolen); |
| 96 | static void z_incomp(void *state, mblk_t *dmsg); |
| 97 | static int z_decompress(void *state, mblk_t *cmp, |
| 98 | mblk_t **dmpp); |
| 99 | static void z_comp_reset(void *state); |
| 100 | static void z_decomp_reset(void *state); |
| 101 | static void z_comp_stats(void *state, struct compstat *stats); |
lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame] | 102 | |
| 103 | /* |
| 104 | * Procedures exported to ppp_comp.c. |
| 105 | */ |
| 106 | struct compressor ppp_deflate = { |
| 107 | CI_DEFLATE, /* compress_proto */ |
| 108 | z_comp_alloc, /* comp_alloc */ |
| 109 | z_comp_free, /* comp_free */ |
| 110 | z_comp_init, /* comp_init */ |
| 111 | z_comp_reset, /* comp_reset */ |
| 112 | z_compress, /* compress */ |
| 113 | z_comp_stats, /* comp_stat */ |
| 114 | z_decomp_alloc, /* decomp_alloc */ |
| 115 | z_decomp_free, /* decomp_free */ |
| 116 | z_decomp_init, /* decomp_init */ |
| 117 | z_decomp_reset, /* decomp_reset */ |
| 118 | z_decompress, /* decompress */ |
| 119 | z_incomp, /* incomp */ |
| 120 | z_comp_stats, /* decomp_stat */ |
| 121 | }; |
| 122 | |
| 123 | struct compressor ppp_deflate_draft = { |
| 124 | CI_DEFLATE_DRAFT, /* compress_proto */ |
| 125 | z_comp_alloc, /* comp_alloc */ |
| 126 | z_comp_free, /* comp_free */ |
| 127 | z_comp_init, /* comp_init */ |
| 128 | z_comp_reset, /* comp_reset */ |
| 129 | z_compress, /* compress */ |
| 130 | z_comp_stats, /* comp_stat */ |
| 131 | z_decomp_alloc, /* decomp_alloc */ |
| 132 | z_decomp_free, /* decomp_free */ |
| 133 | z_decomp_init, /* decomp_init */ |
| 134 | z_decomp_reset, /* decomp_reset */ |
| 135 | z_decompress, /* decompress */ |
| 136 | z_incomp, /* incomp */ |
| 137 | z_comp_stats, /* decomp_stat */ |
| 138 | }; |
| 139 | |
| 140 | #define DECOMP_CHUNK 512 |
| 141 | |
| 142 | /* |
| 143 | * Space allocation and freeing routines for use by zlib routines. |
| 144 | */ |
| 145 | struct zchunk { |
| 146 | u_int size; |
| 147 | u_int guard; |
| 148 | }; |
| 149 | |
| 150 | #define GUARD_MAGIC 0x77a6011a |
| 151 | |
| 152 | static void * |
| 153 | z_alloc_init(notused, items, size) |
| 154 | void *notused; |
| 155 | u_int items, size; |
| 156 | { |
| 157 | struct zchunk *z; |
| 158 | |
| 159 | size = items * size + sizeof(struct zchunk); |
| 160 | #ifdef __osf__ |
| 161 | z = (struct zchunk *) ALLOC_SLEEP(size); |
| 162 | #else |
| 163 | z = (struct zchunk *) ALLOC_NOSLEEP(size); |
| 164 | #endif |
| 165 | z->size = size; |
| 166 | z->guard = GUARD_MAGIC; |
| 167 | return (void *) (z + 1); |
| 168 | } |
| 169 | |
| 170 | static void * |
| 171 | z_alloc(notused, items, size) |
| 172 | void *notused; |
| 173 | u_int items, size; |
| 174 | { |
| 175 | struct zchunk *z; |
| 176 | |
| 177 | size = items * size + sizeof(struct zchunk); |
| 178 | z = (struct zchunk *) ALLOC_NOSLEEP(size); |
| 179 | z->size = size; |
| 180 | z->guard = GUARD_MAGIC; |
| 181 | return (void *) (z + 1); |
| 182 | } |
| 183 | |
| 184 | static void |
| 185 | z_free(notused, ptr) |
| 186 | void *notused; |
| 187 | void *ptr; |
| 188 | { |
| 189 | struct zchunk *z = ((struct zchunk *) ptr) - 1; |
| 190 | |
| 191 | if (z->guard != GUARD_MAGIC) { |
| 192 | printf("ppp: z_free of corrupted chunk at %x (%x, %x)\n", |
| 193 | z, z->size, z->guard); |
| 194 | return; |
| 195 | } |
| 196 | FREE(z, z->size); |
| 197 | } |
| 198 | |
| 199 | /* |
| 200 | * Allocate space for a compressor. |
| 201 | */ |
| 202 | static void * |
| 203 | z_comp_alloc(options, opt_len) |
| 204 | u_char *options; |
| 205 | int opt_len; |
| 206 | { |
| 207 | struct deflate_state *state; |
| 208 | int w_size; |
| 209 | |
| 210 | if (opt_len != CILEN_DEFLATE |
| 211 | || (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT) |
| 212 | || options[1] != CILEN_DEFLATE |
| 213 | || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL |
| 214 | || options[3] != DEFLATE_CHK_SEQUENCE) |
| 215 | return NULL; |
| 216 | w_size = DEFLATE_SIZE(options[2]); |
| 217 | /* |
| 218 | * N.B. the 9 below should be DEFLATE_MIN_SIZE (8), but using |
| 219 | * 8 will cause kernel crashes because of a bug in zlib. |
| 220 | */ |
| 221 | if (w_size < 9 || w_size > DEFLATE_MAX_SIZE) |
| 222 | return NULL; |
| 223 | |
| 224 | |
| 225 | #ifdef __osf__ |
| 226 | state = (struct deflate_state *) ALLOC_SLEEP(sizeof(*state)); |
| 227 | #else |
| 228 | state = (struct deflate_state *) ALLOC_NOSLEEP(sizeof(*state)); |
| 229 | #endif |
| 230 | |
| 231 | if (state == NULL) |
| 232 | return NULL; |
| 233 | |
| 234 | state->strm.next_in = NULL; |
| 235 | state->strm.zalloc = (alloc_func) z_alloc_init; |
| 236 | state->strm.zfree = (free_func) z_free; |
| 237 | if (deflateInit2(&state->strm, Z_DEFAULT_COMPRESSION, DEFLATE_METHOD_VAL, |
| 238 | -w_size, 8, Z_DEFAULT_STRATEGY) != Z_OK) { |
| 239 | FREE(state, sizeof(*state)); |
| 240 | return NULL; |
| 241 | } |
| 242 | |
| 243 | state->strm.zalloc = (alloc_func) z_alloc; |
| 244 | state->w_size = w_size; |
| 245 | bzero(&state->stats, sizeof(state->stats)); |
| 246 | return (void *) state; |
| 247 | } |
| 248 | |
| 249 | static void |
| 250 | z_comp_free(arg) |
| 251 | void *arg; |
| 252 | { |
| 253 | struct deflate_state *state = (struct deflate_state *) arg; |
| 254 | |
| 255 | deflateEnd(&state->strm); |
| 256 | FREE(state, sizeof(*state)); |
| 257 | } |
| 258 | |
| 259 | static int |
| 260 | z_comp_init(arg, options, opt_len, unit, hdrlen, debug) |
| 261 | void *arg; |
| 262 | u_char *options; |
| 263 | int opt_len, unit, hdrlen, debug; |
| 264 | { |
| 265 | struct deflate_state *state = (struct deflate_state *) arg; |
| 266 | |
| 267 | if (opt_len < CILEN_DEFLATE |
| 268 | || (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT) |
| 269 | || options[1] != CILEN_DEFLATE |
| 270 | || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL |
| 271 | || DEFLATE_SIZE(options[2]) != state->w_size |
| 272 | || options[3] != DEFLATE_CHK_SEQUENCE) |
| 273 | return 0; |
| 274 | |
| 275 | state->seqno = 0; |
| 276 | state->unit = unit; |
| 277 | state->hdrlen = hdrlen; |
| 278 | state->debug = debug; |
| 279 | |
| 280 | deflateReset(&state->strm); |
| 281 | |
| 282 | return 1; |
| 283 | } |
| 284 | |
| 285 | static void |
| 286 | z_comp_reset(arg) |
| 287 | void *arg; |
| 288 | { |
| 289 | struct deflate_state *state = (struct deflate_state *) arg; |
| 290 | |
| 291 | state->seqno = 0; |
| 292 | deflateReset(&state->strm); |
| 293 | } |
| 294 | |
| 295 | static int |
| 296 | z_compress(arg, mret, mp, orig_len, maxolen) |
| 297 | void *arg; |
| 298 | mblk_t **mret; /* compressed packet (out) */ |
| 299 | mblk_t *mp; /* uncompressed packet (in) */ |
| 300 | int orig_len, maxolen; |
| 301 | { |
| 302 | struct deflate_state *state = (struct deflate_state *) arg; |
| 303 | u_char *rptr, *wptr; |
| 304 | int proto, olen, wspace, r, flush; |
| 305 | mblk_t *m; |
| 306 | |
| 307 | /* |
| 308 | * Check that the protocol is in the range we handle. |
| 309 | */ |
| 310 | *mret = NULL; |
| 311 | rptr = mp->b_rptr; |
| 312 | if (rptr + PPP_HDRLEN > mp->b_wptr) { |
| 313 | if (!pullupmsg(mp, PPP_HDRLEN)) |
| 314 | return 0; |
| 315 | rptr = mp->b_rptr; |
| 316 | } |
| 317 | proto = PPP_PROTOCOL(rptr); |
| 318 | if (proto > 0x3fff || proto == 0xfd || proto == 0xfb) |
| 319 | return orig_len; |
| 320 | |
| 321 | /* Allocate one mblk initially. */ |
| 322 | if (maxolen > orig_len) |
| 323 | maxolen = orig_len; |
| 324 | if (maxolen <= PPP_HDRLEN + 2) { |
| 325 | wspace = 0; |
| 326 | m = NULL; |
| 327 | } else { |
| 328 | wspace = maxolen + state->hdrlen; |
| 329 | if (wspace > 4096) |
| 330 | wspace = 4096; |
| 331 | m = allocb(wspace, BPRI_MED); |
| 332 | } |
| 333 | if (m != NULL) { |
| 334 | *mret = m; |
| 335 | if (state->hdrlen + PPP_HDRLEN + 2 < wspace) { |
| 336 | m->b_rptr += state->hdrlen; |
| 337 | m->b_wptr = m->b_rptr; |
| 338 | wspace -= state->hdrlen; |
| 339 | } |
| 340 | wptr = m->b_wptr; |
| 341 | |
| 342 | /* |
| 343 | * Copy over the PPP header and store the 2-byte sequence number. |
| 344 | */ |
| 345 | wptr[0] = PPP_ADDRESS(rptr); |
| 346 | wptr[1] = PPP_CONTROL(rptr); |
| 347 | wptr[2] = PPP_COMP >> 8; |
| 348 | wptr[3] = PPP_COMP; |
| 349 | wptr += PPP_HDRLEN; |
| 350 | wptr[0] = state->seqno >> 8; |
| 351 | wptr[1] = state->seqno; |
| 352 | wptr += 2; |
| 353 | state->strm.next_out = wptr; |
| 354 | state->strm.avail_out = wspace - (PPP_HDRLEN + 2); |
| 355 | } else { |
| 356 | state->strm.next_out = NULL; |
| 357 | state->strm.avail_out = 1000000; |
| 358 | } |
| 359 | ++state->seqno; |
| 360 | |
| 361 | rptr += (proto > 0xff)? 2: 3; /* skip 1st proto byte if 0 */ |
| 362 | state->strm.next_in = rptr; |
| 363 | state->strm.avail_in = mp->b_wptr - rptr; |
| 364 | mp = mp->b_cont; |
| 365 | flush = (mp == NULL)? Z_PACKET_FLUSH: Z_NO_FLUSH; |
| 366 | olen = 0; |
| 367 | for (;;) { |
| 368 | r = deflate(&state->strm, flush); |
| 369 | if (r != Z_OK) { |
| 370 | printf("z_compress: deflate returned %d (%s)\n", |
| 371 | r, (state->strm.msg? state->strm.msg: "")); |
| 372 | break; |
| 373 | } |
| 374 | if (flush != Z_NO_FLUSH && state->strm.avail_out != 0) |
| 375 | break; /* all done */ |
| 376 | if (state->strm.avail_in == 0 && mp != NULL) { |
| 377 | state->strm.next_in = mp->b_rptr; |
| 378 | state->strm.avail_in = mp->b_wptr - mp->b_rptr; |
| 379 | mp = mp->b_cont; |
| 380 | if (mp == NULL) |
| 381 | flush = Z_PACKET_FLUSH; |
| 382 | } |
| 383 | if (state->strm.avail_out == 0) { |
| 384 | if (m != NULL) { |
| 385 | m->b_wptr += wspace; |
| 386 | olen += wspace; |
| 387 | wspace = maxolen - olen; |
| 388 | if (wspace <= 0) { |
| 389 | wspace = 0; |
| 390 | m->b_cont = NULL; |
| 391 | } else { |
| 392 | if (wspace < 32) |
| 393 | wspace = 32; |
| 394 | else if (wspace > 4096) |
| 395 | wspace = 4096; |
| 396 | m->b_cont = allocb(wspace, BPRI_MED); |
| 397 | } |
| 398 | m = m->b_cont; |
| 399 | if (m != NULL) { |
| 400 | state->strm.next_out = m->b_wptr; |
| 401 | state->strm.avail_out = wspace; |
| 402 | } |
| 403 | } |
| 404 | if (m == NULL) { |
| 405 | state->strm.next_out = NULL; |
| 406 | state->strm.avail_out = 1000000; |
| 407 | } |
| 408 | } |
| 409 | } |
| 410 | if (m != NULL) { |
| 411 | m->b_wptr += wspace - state->strm.avail_out; |
| 412 | olen += wspace - state->strm.avail_out; |
| 413 | } |
| 414 | |
| 415 | /* |
| 416 | * See if we managed to reduce the size of the packet. |
| 417 | */ |
| 418 | if (olen < orig_len && m != NULL) { |
| 419 | state->stats.comp_bytes += olen; |
| 420 | state->stats.comp_packets++; |
| 421 | } else { |
| 422 | if (*mret != NULL) { |
| 423 | freemsg(*mret); |
| 424 | *mret = NULL; |
| 425 | } |
| 426 | state->stats.inc_bytes += orig_len; |
| 427 | state->stats.inc_packets++; |
| 428 | olen = orig_len; |
| 429 | } |
| 430 | state->stats.unc_bytes += orig_len; |
| 431 | state->stats.unc_packets++; |
| 432 | |
| 433 | return olen; |
| 434 | } |
| 435 | |
| 436 | static void |
| 437 | z_comp_stats(arg, stats) |
| 438 | void *arg; |
| 439 | struct compstat *stats; |
| 440 | { |
| 441 | struct deflate_state *state = (struct deflate_state *) arg; |
| 442 | u_int out; |
| 443 | |
| 444 | *stats = state->stats; |
| 445 | stats->ratio = stats->unc_bytes; |
| 446 | out = stats->comp_bytes + stats->unc_bytes; |
| 447 | if (stats->ratio <= 0x7ffffff) |
| 448 | stats->ratio <<= 8; |
| 449 | else |
| 450 | out >>= 8; |
| 451 | if (out != 0) |
| 452 | stats->ratio /= out; |
| 453 | } |
| 454 | |
| 455 | /* |
| 456 | * Allocate space for a decompressor. |
| 457 | */ |
| 458 | static void * |
| 459 | z_decomp_alloc(options, opt_len) |
| 460 | u_char *options; |
| 461 | int opt_len; |
| 462 | { |
| 463 | struct deflate_state *state; |
| 464 | int w_size; |
| 465 | |
| 466 | if (opt_len != CILEN_DEFLATE |
| 467 | || (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT) |
| 468 | || options[1] != CILEN_DEFLATE |
| 469 | || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL |
| 470 | || options[3] != DEFLATE_CHK_SEQUENCE) |
| 471 | return NULL; |
| 472 | w_size = DEFLATE_SIZE(options[2]); |
| 473 | /* |
| 474 | * N.B. the 9 below should be DEFLATE_MIN_SIZE (8), but using |
| 475 | * 8 will cause kernel crashes because of a bug in zlib. |
| 476 | */ |
| 477 | if (w_size < 9 || w_size > DEFLATE_MAX_SIZE) |
| 478 | return NULL; |
| 479 | |
| 480 | #ifdef __osf__ |
| 481 | state = (struct deflate_state *) ALLOC_SLEEP(sizeof(*state)); |
| 482 | #else |
| 483 | state = (struct deflate_state *) ALLOC_NOSLEEP(sizeof(*state)); |
| 484 | #endif |
| 485 | if (state == NULL) |
| 486 | return NULL; |
| 487 | |
| 488 | state->strm.next_out = NULL; |
| 489 | state->strm.zalloc = (alloc_func) z_alloc_init; |
| 490 | state->strm.zfree = (free_func) z_free; |
| 491 | if (inflateInit2(&state->strm, -w_size) != Z_OK) { |
| 492 | FREE(state, sizeof(*state)); |
| 493 | return NULL; |
| 494 | } |
| 495 | |
| 496 | state->strm.zalloc = (alloc_func) z_alloc; |
| 497 | state->w_size = w_size; |
| 498 | bzero(&state->stats, sizeof(state->stats)); |
| 499 | return (void *) state; |
| 500 | } |
| 501 | |
| 502 | static void |
| 503 | z_decomp_free(arg) |
| 504 | void *arg; |
| 505 | { |
| 506 | struct deflate_state *state = (struct deflate_state *) arg; |
| 507 | |
| 508 | inflateEnd(&state->strm); |
| 509 | FREE(state, sizeof(*state)); |
| 510 | } |
| 511 | |
| 512 | static int |
| 513 | z_decomp_init(arg, options, opt_len, unit, hdrlen, mru, debug) |
| 514 | void *arg; |
| 515 | u_char *options; |
| 516 | int opt_len, unit, hdrlen, mru, debug; |
| 517 | { |
| 518 | struct deflate_state *state = (struct deflate_state *) arg; |
| 519 | |
| 520 | if (opt_len < CILEN_DEFLATE |
| 521 | || (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT) |
| 522 | || options[1] != CILEN_DEFLATE |
| 523 | || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL |
| 524 | || DEFLATE_SIZE(options[2]) != state->w_size |
| 525 | || options[3] != DEFLATE_CHK_SEQUENCE) |
| 526 | return 0; |
| 527 | |
| 528 | state->seqno = 0; |
| 529 | state->unit = unit; |
| 530 | state->hdrlen = hdrlen; |
| 531 | state->debug = debug; |
| 532 | state->mru = mru; |
| 533 | |
| 534 | inflateReset(&state->strm); |
| 535 | |
| 536 | return 1; |
| 537 | } |
| 538 | |
| 539 | static void |
| 540 | z_decomp_reset(arg) |
| 541 | void *arg; |
| 542 | { |
| 543 | struct deflate_state *state = (struct deflate_state *) arg; |
| 544 | |
| 545 | state->seqno = 0; |
| 546 | inflateReset(&state->strm); |
| 547 | } |
| 548 | |
| 549 | /* |
| 550 | * Decompress a Deflate-compressed packet. |
| 551 | * |
| 552 | * Because of patent problems, we return DECOMP_ERROR for errors |
| 553 | * found by inspecting the input data and for system problems, but |
| 554 | * DECOMP_FATALERROR for any errors which could possibly be said to |
| 555 | * be being detected "after" decompression. For DECOMP_ERROR, |
| 556 | * we can issue a CCP reset-request; for DECOMP_FATALERROR, we may be |
| 557 | * infringing a patent of Motorola's if we do, so we take CCP down |
| 558 | * instead. |
| 559 | * |
| 560 | * Given that the frame has the correct sequence number and a good FCS, |
| 561 | * errors such as invalid codes in the input most likely indicate a |
| 562 | * bug, so we return DECOMP_FATALERROR for them in order to turn off |
| 563 | * compression, even though they are detected by inspecting the input. |
| 564 | */ |
| 565 | static int |
| 566 | z_decompress(arg, mi, mop) |
| 567 | void *arg; |
| 568 | mblk_t *mi, **mop; |
| 569 | { |
| 570 | struct deflate_state *state = (struct deflate_state *) arg; |
| 571 | mblk_t *mo, *mo_head; |
| 572 | u_char *rptr, *wptr; |
| 573 | int rlen, olen, ospace; |
| 574 | int seq, i, flush, r, decode_proto; |
| 575 | u_char hdr[PPP_HDRLEN + DEFLATE_OVHD]; |
| 576 | |
| 577 | *mop = NULL; |
| 578 | rptr = mi->b_rptr; |
| 579 | for (i = 0; i < PPP_HDRLEN + DEFLATE_OVHD; ++i) { |
| 580 | while (rptr >= mi->b_wptr) { |
| 581 | mi = mi->b_cont; |
| 582 | if (mi == NULL) |
| 583 | return DECOMP_ERROR; |
| 584 | rptr = mi->b_rptr; |
| 585 | } |
| 586 | hdr[i] = *rptr++; |
| 587 | } |
| 588 | |
| 589 | /* Check the sequence number. */ |
| 590 | seq = (hdr[PPP_HDRLEN] << 8) + hdr[PPP_HDRLEN+1]; |
| 591 | if (seq != state->seqno) { |
| 592 | #if !DEFLATE_DEBUG |
| 593 | if (state->debug) |
| 594 | #endif |
| 595 | printf("z_decompress%d: bad seq # %d, expected %d\n", |
| 596 | state->unit, seq, state->seqno); |
| 597 | return DECOMP_ERROR; |
| 598 | } |
| 599 | ++state->seqno; |
| 600 | |
| 601 | /* Allocate an output message block. */ |
| 602 | mo = allocb(DECOMP_CHUNK + state->hdrlen, BPRI_MED); |
| 603 | if (mo == NULL) |
| 604 | return DECOMP_ERROR; |
| 605 | mo_head = mo; |
| 606 | mo->b_cont = NULL; |
| 607 | mo->b_rptr += state->hdrlen; |
| 608 | mo->b_wptr = wptr = mo->b_rptr; |
| 609 | ospace = DECOMP_CHUNK; |
| 610 | olen = 0; |
| 611 | |
| 612 | /* |
| 613 | * Fill in the first part of the PPP header. The protocol field |
| 614 | * comes from the decompressed data. |
| 615 | */ |
| 616 | wptr[0] = PPP_ADDRESS(hdr); |
| 617 | wptr[1] = PPP_CONTROL(hdr); |
| 618 | wptr[2] = 0; |
| 619 | |
| 620 | /* |
| 621 | * Set up to call inflate. We set avail_out to 1 initially so we can |
| 622 | * look at the first byte of the output and decide whether we have |
| 623 | * a 1-byte or 2-byte protocol field. |
| 624 | */ |
| 625 | state->strm.next_in = rptr; |
| 626 | state->strm.avail_in = mi->b_wptr - rptr; |
| 627 | mi = mi->b_cont; |
| 628 | flush = (mi == NULL)? Z_PACKET_FLUSH: Z_NO_FLUSH; |
| 629 | rlen = state->strm.avail_in + PPP_HDRLEN + DEFLATE_OVHD; |
| 630 | state->strm.next_out = wptr + 3; |
| 631 | state->strm.avail_out = 1; |
| 632 | decode_proto = 1; |
| 633 | |
| 634 | /* |
| 635 | * Call inflate, supplying more input or output as needed. |
| 636 | */ |
| 637 | for (;;) { |
| 638 | r = inflate(&state->strm, flush); |
| 639 | if (r != Z_OK) { |
| 640 | #if !DEFLATE_DEBUG |
| 641 | if (state->debug) |
| 642 | #endif |
| 643 | printf("z_decompress%d: inflate returned %d (%s)\n", |
| 644 | state->unit, r, (state->strm.msg? state->strm.msg: "")); |
| 645 | freemsg(mo_head); |
| 646 | return DECOMP_FATALERROR; |
| 647 | } |
| 648 | if (flush != Z_NO_FLUSH && state->strm.avail_out != 0) |
| 649 | break; /* all done */ |
| 650 | if (state->strm.avail_in == 0 && mi != NULL) { |
| 651 | state->strm.next_in = mi->b_rptr; |
| 652 | state->strm.avail_in = mi->b_wptr - mi->b_rptr; |
| 653 | rlen += state->strm.avail_in; |
| 654 | mi = mi->b_cont; |
| 655 | if (mi == NULL) |
| 656 | flush = Z_PACKET_FLUSH; |
| 657 | } |
| 658 | if (state->strm.avail_out == 0) { |
| 659 | if (decode_proto) { |
| 660 | state->strm.avail_out = ospace - PPP_HDRLEN; |
| 661 | if ((wptr[3] & 1) == 0) { |
| 662 | /* 2-byte protocol field */ |
| 663 | wptr[2] = wptr[3]; |
| 664 | --state->strm.next_out; |
| 665 | ++state->strm.avail_out; |
| 666 | } |
| 667 | decode_proto = 0; |
| 668 | } else { |
| 669 | mo->b_wptr += ospace; |
| 670 | olen += ospace; |
| 671 | mo->b_cont = allocb(DECOMP_CHUNK, BPRI_MED); |
| 672 | mo = mo->b_cont; |
| 673 | if (mo == NULL) { |
| 674 | freemsg(mo_head); |
| 675 | return DECOMP_ERROR; |
| 676 | } |
| 677 | state->strm.next_out = mo->b_rptr; |
| 678 | state->strm.avail_out = ospace = DECOMP_CHUNK; |
| 679 | } |
| 680 | } |
| 681 | } |
| 682 | if (decode_proto) { |
| 683 | freemsg(mo_head); |
| 684 | return DECOMP_ERROR; |
| 685 | } |
| 686 | mo->b_wptr += ospace - state->strm.avail_out; |
| 687 | olen += ospace - state->strm.avail_out; |
| 688 | |
| 689 | #if DEFLATE_DEBUG |
| 690 | if (olen > state->mru + PPP_HDRLEN) |
| 691 | printf("ppp_deflate%d: exceeded mru (%d > %d)\n", |
| 692 | state->unit, olen, state->mru + PPP_HDRLEN); |
| 693 | #endif |
| 694 | |
| 695 | state->stats.unc_bytes += olen; |
| 696 | state->stats.unc_packets++; |
| 697 | state->stats.comp_bytes += rlen; |
| 698 | state->stats.comp_packets++; |
| 699 | |
| 700 | *mop = mo_head; |
| 701 | return DECOMP_OK; |
| 702 | } |
| 703 | |
| 704 | /* |
| 705 | * Incompressible data has arrived - add it to the history. |
| 706 | */ |
| 707 | static void |
| 708 | z_incomp(arg, mi) |
| 709 | void *arg; |
| 710 | mblk_t *mi; |
| 711 | { |
| 712 | struct deflate_state *state = (struct deflate_state *) arg; |
| 713 | u_char *rptr; |
| 714 | int rlen, proto, r; |
| 715 | |
| 716 | /* |
| 717 | * Check that the protocol is one we handle. |
| 718 | */ |
| 719 | rptr = mi->b_rptr; |
| 720 | if (rptr + PPP_HDRLEN > mi->b_wptr) { |
| 721 | if (!pullupmsg(mi, PPP_HDRLEN)) |
| 722 | return; |
| 723 | rptr = mi->b_rptr; |
| 724 | } |
| 725 | proto = PPP_PROTOCOL(rptr); |
| 726 | if (proto > 0x3fff || proto == 0xfd || proto == 0xfb) |
| 727 | return; |
| 728 | |
| 729 | ++state->seqno; |
| 730 | |
| 731 | /* |
| 732 | * Iterate through the message blocks, adding the characters in them |
| 733 | * to the decompressor's history. For the first block, we start |
| 734 | * at the either the 1st or 2nd byte of the protocol field, |
| 735 | * depending on whether the protocol value is compressible. |
| 736 | */ |
| 737 | rlen = mi->b_wptr - mi->b_rptr; |
| 738 | state->strm.next_in = rptr + 3; |
| 739 | state->strm.avail_in = rlen - 3; |
| 740 | if (proto > 0xff) { |
| 741 | --state->strm.next_in; |
| 742 | ++state->strm.avail_in; |
| 743 | } |
| 744 | for (;;) { |
| 745 | r = inflateIncomp(&state->strm); |
| 746 | if (r != Z_OK) { |
| 747 | /* gak! */ |
| 748 | #if !DEFLATE_DEBUG |
| 749 | if (state->debug) |
| 750 | #endif |
| 751 | printf("z_incomp%d: inflateIncomp returned %d (%s)\n", |
| 752 | state->unit, r, (state->strm.msg? state->strm.msg: "")); |
| 753 | return; |
| 754 | } |
| 755 | mi = mi->b_cont; |
| 756 | if (mi == NULL) |
| 757 | break; |
| 758 | state->strm.next_in = mi->b_rptr; |
| 759 | state->strm.avail_in = mi->b_wptr - mi->b_rptr; |
| 760 | rlen += state->strm.avail_in; |
| 761 | } |
| 762 | |
| 763 | /* |
| 764 | * Update stats. |
| 765 | */ |
| 766 | state->stats.inc_bytes += rlen; |
| 767 | state->stats.inc_packets++; |
| 768 | state->stats.unc_bytes += rlen; |
| 769 | state->stats.unc_packets++; |
| 770 | } |
| 771 | |
| 772 | #endif /* DO_DEFLATE */ |