diff options
author | Mystery Man <unknown@mandriva.org> | 2002-09-03 22:11:26 +0000 |
---|---|---|
committer | Mystery Man <unknown@mandriva.org> | 2002-09-03 22:11:26 +0000 |
commit | 27a26c82a667e1091f468e77f7a688341e3fccae (patch) | |
tree | c8c525b36c9c25cd49d2169f65abfc479cad54f5 /mdk-stage1/ppp/pppdump/bsd-comp.c | |
parent | ea2afedb2e1bb848dcc27a605a14e3e3ddebbf48 (diff) | |
download | drakx-27a26c82a667e1091f468e77f7a688341e3fccae.tar drakx-27a26c82a667e1091f468e77f7a688341e3fccae.tar.gz drakx-27a26c82a667e1091f468e77f7a688341e3fccae.tar.bz2 drakx-27a26c82a667e1091f468e77f7a688341e3fccae.tar.xz drakx-27a26c82a667e1091f468e77f7a688341e3fccae.zip |
This commit was manufactured by cvs2svn to create tag 'V1_1_9_31mdk'.V1_1_9_31mdk
Diffstat (limited to 'mdk-stage1/ppp/pppdump/bsd-comp.c')
-rw-r--r-- | mdk-stage1/ppp/pppdump/bsd-comp.c | 750 |
1 files changed, 0 insertions, 750 deletions
diff --git a/mdk-stage1/ppp/pppdump/bsd-comp.c b/mdk-stage1/ppp/pppdump/bsd-comp.c deleted file mode 100644 index 1e14e98bb..000000000 --- a/mdk-stage1/ppp/pppdump/bsd-comp.c +++ /dev/null @@ -1,750 +0,0 @@ -/* Because this code is derived from the 4.3BSD compress source: - * - * - * Copyright (c) 1985, 1986 The Regents of the University of California. - * All rights reserved. - * - * This code is derived from software contributed to Berkeley by - * James A. Woods, derived from original work by Spencer Thomas - * and Joseph Orost. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * 3. All advertising materials mentioning features or use of this software - * must display the following acknowledgement: - * This product includes software developed by the University of - * California, Berkeley and its contributors. - * 4. Neither the name of the University nor the names of its contributors - * may be used to endorse or promote products derived from this software - * without specific prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND - * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE - * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE - * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL - * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS - * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) - * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT - * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY - * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF - * SUCH DAMAGE. - */ - -/* - * $Id$ - */ - -#include <sys/types.h> -#include <stddef.h> -#include <stdlib.h> -#include "ppp_defs.h" -#include "ppp-comp.h" - -#if DO_BSD_COMPRESS - -/* - * PPP "BSD compress" compression - * The differences between this compression and the classic BSD LZW - * source are obvious from the requirement that the classic code worked - * with files while this handles arbitrarily long streams that - * are broken into packets. They are: - * - * When the code size expands, a block of junk is not emitted by - * the compressor and not expected by the decompressor. - * - * New codes are not necessarily assigned every time an old - * code is output by the compressor. This is because a packet - * end forces a code to be emitted, but does not imply that a - * new sequence has been seen. - * - * The compression ratio is checked at the first end of a packet - * after the appropriate gap. Besides simplifying and speeding - * things up, this makes it more likely that the transmitter - * and receiver will agree when the dictionary is cleared when - * compression is not going well. - */ - -/* - * A dictionary for doing BSD compress. - */ -struct bsd_db { - int totlen; /* length of this structure */ - u_int hsize; /* size of the hash table */ - u_char hshift; /* used in hash function */ - u_char n_bits; /* current bits/code */ - u_char maxbits; - u_char debug; - u_char unit; - u_short seqno; /* sequence number of next packet */ - u_int hdrlen; /* header length to preallocate */ - u_int mru; - u_int maxmaxcode; /* largest valid code */ - u_int max_ent; /* largest code in use */ - u_int in_count; /* uncompressed bytes, aged */ - u_int bytes_out; /* compressed bytes, aged */ - u_int ratio; /* recent compression ratio */ - u_int checkpoint; /* when to next check the ratio */ - u_int clear_count; /* times dictionary cleared */ - u_int incomp_count; /* incompressible packets */ - u_int incomp_bytes; /* incompressible bytes */ - u_int uncomp_count; /* uncompressed packets */ - u_int uncomp_bytes; /* uncompressed bytes */ - u_int comp_count; /* compressed packets */ - u_int comp_bytes; /* compressed bytes */ - u_short *lens; /* array of lengths of codes */ - struct bsd_dict { - union { /* hash value */ - u_int32_t fcode; - struct { -#ifdef BSD_LITTLE_ENDIAN - u_short prefix; /* preceding code */ - u_char suffix; /* last character of new code */ - u_char pad; -#else - u_char pad; - u_char suffix; /* last character of new code */ - u_short prefix; /* preceding code */ -#endif - } hs; - } f; - u_short codem1; /* output of hash table -1 */ - u_short cptr; /* map code to hash table entry */ - } dict[1]; -}; - -#define BSD_OVHD 2 /* BSD compress overhead/packet */ -#define BSD_INIT_BITS BSD_MIN_BITS - -static void *bsd_decomp_alloc __P((u_char *options, int opt_len)); -static void bsd_free __P((void *state)); -static int bsd_decomp_init __P((void *state, u_char *options, int opt_len, - int unit, int hdrlen, int mru, int debug)); -static void bsd_incomp __P((void *state, u_char *dmsg, int len)); -static int bsd_decompress __P((void *state, u_char *cmp, int inlen, - u_char *dmp, int *outlen)); -static void bsd_reset __P((void *state)); -static void bsd_comp_stats __P((void *state, struct compstat *stats)); - -/* - * Exported procedures. - */ -struct compressor ppp_bsd_compress = { - CI_BSD_COMPRESS, /* compress_proto */ - bsd_decomp_alloc, /* decomp_alloc */ - bsd_free, /* decomp_free */ - bsd_decomp_init, /* decomp_init */ - bsd_reset, /* decomp_reset */ - bsd_decompress, /* decompress */ - bsd_incomp, /* incomp */ - bsd_comp_stats, /* decomp_stat */ -}; - -/* - * the next two codes should not be changed lightly, as they must not - * lie within the contiguous general code space. - */ -#define CLEAR 256 /* table clear output code */ -#define FIRST 257 /* first free entry */ -#define LAST 255 - -#define MAXCODE(b) ((1 << (b)) - 1) -#define BADCODEM1 MAXCODE(BSD_MAX_BITS) - -#define BSD_HASH(prefix,suffix,hshift) ((((u_int32_t)(suffix)) << (hshift)) \ - ^ (u_int32_t)(prefix)) -#define BSD_KEY(prefix,suffix) ((((u_int32_t)(suffix)) << 16) \ - + (u_int32_t)(prefix)) - -#define CHECK_GAP 10000 /* Ratio check interval */ - -#define RATIO_SCALE_LOG 8 -#define RATIO_SCALE (1<<RATIO_SCALE_LOG) -#define RATIO_MAX (0x7fffffff>>RATIO_SCALE_LOG) - -/* - * clear the dictionary - */ -static void -bsd_clear(db) - struct bsd_db *db; -{ - db->clear_count++; - db->max_ent = FIRST-1; - db->n_bits = BSD_INIT_BITS; - db->ratio = 0; - db->bytes_out = 0; - db->in_count = 0; - db->checkpoint = CHECK_GAP; -} - -/* - * If the dictionary is full, then see if it is time to reset it. - * - * Compute the compression ratio using fixed-point arithmetic - * with 8 fractional bits. - * - * Since we have an infinite stream instead of a single file, - * watch only the local compression ratio. - * - * Since both peers must reset the dictionary at the same time even in - * the absence of CLEAR codes (while packets are incompressible), they - * must compute the same ratio. - */ -static int /* 1=output CLEAR */ -bsd_check(db) - struct bsd_db *db; -{ - u_int new_ratio; - - if (db->in_count >= db->checkpoint) { - /* age the ratio by limiting the size of the counts */ - if (db->in_count >= RATIO_MAX - || db->bytes_out >= RATIO_MAX) { - db->in_count -= db->in_count/4; - db->bytes_out -= db->bytes_out/4; - } - - db->checkpoint = db->in_count + CHECK_GAP; - - if (db->max_ent >= db->maxmaxcode) { - /* Reset the dictionary only if the ratio is worse, - * or if it looks as if it has been poisoned - * by incompressible data. - * - * This does not overflow, because - * db->in_count <= RATIO_MAX. - */ - new_ratio = db->in_count << RATIO_SCALE_LOG; - if (db->bytes_out != 0) - new_ratio /= db->bytes_out; - - if (new_ratio < db->ratio || new_ratio < 1 * RATIO_SCALE) { - bsd_clear(db); - return 1; - } - db->ratio = new_ratio; - } - } - return 0; -} - -/* - * Return statistics. - */ -static void -bsd_comp_stats(state, stats) - void *state; - struct compstat *stats; -{ - struct bsd_db *db = (struct bsd_db *) state; - u_int out; - - stats->unc_bytes = db->uncomp_bytes; - stats->unc_packets = db->uncomp_count; - stats->comp_bytes = db->comp_bytes; - stats->comp_packets = db->comp_count; - stats->inc_bytes = db->incomp_bytes; - stats->inc_packets = db->incomp_count; - stats->ratio = db->in_count; - out = db->bytes_out; - if (stats->ratio <= 0x7fffff) - stats->ratio <<= 8; - else - out >>= 8; - if (out != 0) - stats->ratio /= out; -} - -/* - * Reset state, as on a CCP ResetReq. - */ -static void -bsd_reset(state) - void *state; -{ - struct bsd_db *db = (struct bsd_db *) state; - - db->seqno = 0; - bsd_clear(db); - db->clear_count = 0; -} - -/* - * Allocate space for a (de) compressor. - */ -static void * -bsd_alloc(options, opt_len, decomp) - u_char *options; - int opt_len, decomp; -{ - int bits; - u_int newlen, hsize, hshift, maxmaxcode; - struct bsd_db *db; - - if (opt_len != 3 || options[0] != CI_BSD_COMPRESS || options[1] != 3 - || BSD_VERSION(options[2]) != BSD_CURRENT_VERSION) - return NULL; - - bits = BSD_NBITS(options[2]); - switch (bits) { - case 9: /* needs 82152 for both directions */ - case 10: /* needs 84144 */ - case 11: /* needs 88240 */ - case 12: /* needs 96432 */ - hsize = 5003; - hshift = 4; - break; - case 13: /* needs 176784 */ - hsize = 9001; - hshift = 5; - break; - case 14: /* needs 353744 */ - hsize = 18013; - hshift = 6; - break; - case 15: /* needs 691440 */ - hsize = 35023; - hshift = 7; - break; - case 16: /* needs 1366160--far too much, */ - /* hsize = 69001; */ /* and 69001 is too big for cptr */ - /* hshift = 8; */ /* in struct bsd_db */ - /* break; */ - default: - return NULL; - } - - maxmaxcode = MAXCODE(bits); - newlen = sizeof(*db) + (hsize-1) * (sizeof(db->dict[0])); - db = (struct bsd_db *) malloc(newlen); - if (!db) - return NULL; - memset(db, 0, sizeof(*db) - sizeof(db->dict)); - - if (!decomp) { - db->lens = NULL; - } else { - db->lens = (u_short *) malloc((maxmaxcode+1) * sizeof(db->lens[0])); - if (!db->lens) { - free(db); - return NULL; - } - } - - db->totlen = newlen; - db->hsize = hsize; - db->hshift = hshift; - db->maxmaxcode = maxmaxcode; - db->maxbits = bits; - - return (void *) db; -} - -static void -bsd_free(state) - void *state; -{ - struct bsd_db *db = (struct bsd_db *) state; - - if (db->lens) - free(db->lens); - free(db); -} - -static void * -bsd_decomp_alloc(options, opt_len) - u_char *options; - int opt_len; -{ - return bsd_alloc(options, opt_len, 1); -} - -/* - * Initialize the database. - */ -static int -bsd_init(db, options, opt_len, unit, hdrlen, mru, debug, decomp) - struct bsd_db *db; - u_char *options; - int opt_len, unit, hdrlen, mru, debug, decomp; -{ - int i; - - if (opt_len < CILEN_BSD_COMPRESS - || options[0] != CI_BSD_COMPRESS || options[1] != CILEN_BSD_COMPRESS - || BSD_VERSION(options[2]) != BSD_CURRENT_VERSION - || BSD_NBITS(options[2]) != db->maxbits - || decomp && db->lens == NULL) - return 0; - - if (decomp) { - i = LAST+1; - while (i != 0) - db->lens[--i] = 1; - } - i = db->hsize; - while (i != 0) { - db->dict[--i].codem1 = BADCODEM1; - db->dict[i].cptr = 0; - } - - db->unit = unit; - db->hdrlen = hdrlen; - db->mru = mru; - if (debug) - db->debug = 1; - - bsd_reset(db); - - return 1; -} - -static int -bsd_decomp_init(state, options, opt_len, unit, hdrlen, mru, debug) - void *state; - u_char *options; - int opt_len, unit, hdrlen, mru, debug; -{ - return bsd_init((struct bsd_db *) state, options, opt_len, - unit, hdrlen, mru, debug, 1); -} - - -/* - * Update the "BSD Compress" dictionary on the receiver for - * incompressible data by pretending to compress the incoming data. - */ -static void -bsd_incomp(state, dmsg, mlen) - void *state; - u_char *dmsg; - int mlen; -{ - struct bsd_db *db = (struct bsd_db *) state; - u_int hshift = db->hshift; - u_int max_ent = db->max_ent; - u_int n_bits = db->n_bits; - struct bsd_dict *dictp; - u_int32_t fcode; - u_char c; - long hval, disp; - int slen, ilen; - u_int bitno = 7; - u_char *rptr; - u_int ent; - - rptr = dmsg; - ent = rptr[0]; /* get the protocol */ - if (ent == 0) { - ++rptr; - --mlen; - ent = rptr[0]; - } - if ((ent & 1) == 0 || ent < 0x21 || ent > 0xf9) - return; - - db->seqno++; - ilen = 1; /* count the protocol as 1 byte */ - ++rptr; - slen = dmsg + mlen - rptr; - ilen += slen; - for (; slen > 0; --slen) { - c = *rptr++; - fcode = BSD_KEY(ent, c); - hval = BSD_HASH(ent, c, hshift); - dictp = &db->dict[hval]; - - /* validate and then check the entry */ - if (dictp->codem1 >= max_ent) - goto nomatch; - if (dictp->f.fcode == fcode) { - ent = dictp->codem1+1; - continue; /* found (prefix,suffix) */ - } - - /* continue probing until a match or invalid entry */ - disp = (hval == 0) ? 1 : hval; - do { - hval += disp; - if (hval >= db->hsize) - hval -= db->hsize; - dictp = &db->dict[hval]; - if (dictp->codem1 >= max_ent) - goto nomatch; - } while (dictp->f.fcode != fcode); - ent = dictp->codem1+1; - continue; /* finally found (prefix,suffix) */ - - nomatch: /* output (count) the prefix */ - bitno += n_bits; - - /* code -> hashtable */ - if (max_ent < db->maxmaxcode) { - struct bsd_dict *dictp2; - /* expand code size if needed */ - if (max_ent >= MAXCODE(n_bits)) - db->n_bits = ++n_bits; - - /* Invalidate previous hash table entry - * assigned this code, and then take it over. - */ - dictp2 = &db->dict[max_ent+1]; - if (db->dict[dictp2->cptr].codem1 == max_ent) - db->dict[dictp2->cptr].codem1 = BADCODEM1; - dictp2->cptr = hval; - dictp->codem1 = max_ent; - dictp->f.fcode = fcode; - - db->max_ent = ++max_ent; - db->lens[max_ent] = db->lens[ent]+1; - } - ent = c; - } - bitno += n_bits; /* output (count) the last code */ - db->bytes_out += bitno/8; - db->in_count += ilen; - (void)bsd_check(db); - - ++db->incomp_count; - db->incomp_bytes += ilen; - ++db->uncomp_count; - db->uncomp_bytes += ilen; - - /* Increase code size if we would have without the packet - * boundary and as the decompressor will. - */ - if (max_ent >= MAXCODE(n_bits) && max_ent < db->maxmaxcode) - db->n_bits++; -} - - -/* - * Decompress "BSD Compress" - * - * Because of patent problems, we return DECOMP_ERROR for errors - * found by inspecting the input data and for system problems, but - * DECOMP_FATALERROR for any errors which could possibly be said to - * be being detected "after" decompression. For DECOMP_ERROR, - * we can issue a CCP reset-request; for DECOMP_FATALERROR, we may be - * infringing a patent of Motorola's if we do, so we take CCP down - * instead. - * - * Given that the frame has the correct sequence number and a good FCS, - * errors such as invalid codes in the input most likely indicate a - * bug, so we return DECOMP_FATALERROR for them in order to turn off - * compression, even though they are detected by inspecting the input. - */ -static int -bsd_decompress(state, cmsg, inlen, dmp, outlenp) - void *state; - u_char *cmsg, *dmp; - int inlen, *outlenp; -{ - struct bsd_db *db = (struct bsd_db *) state; - u_int max_ent = db->max_ent; - u_int32_t accm = 0; - u_int bitno = 32; /* 1st valid bit in accm */ - u_int n_bits = db->n_bits; - u_int tgtbitno = 32-n_bits; /* bitno when we have a code */ - struct bsd_dict *dictp; - int explen, i, seq, len; - u_int incode, oldcode, finchar; - u_char *p, *rptr, *wptr; - int ilen; - int dlen, space, codelen, extra; - - rptr = cmsg; - if (*rptr == 0) - ++rptr; - ++rptr; /* skip protocol (assumed 0xfd) */ - seq = (rptr[0] << 8) + rptr[1]; - rptr += BSD_OVHD; - ilen = len = cmsg + inlen - rptr; - - /* - * Check the sequence number and give up if it is not what we expect. - */ - if (seq != db->seqno++) { - if (db->debug) - printf("bsd_decomp%d: bad sequence # %d, expected %d\n", - db->unit, seq, db->seqno - 1); - return DECOMP_ERROR; - } - - wptr = dmp + db->hdrlen; - - oldcode = CLEAR; - explen = 0; - while (len > 0) { - /* - * Accumulate bytes until we have a complete code. - * Then get the next code, relying on the 32-bit, - * unsigned accm to mask the result. - */ - bitno -= 8; - accm |= *rptr++ << bitno; - --len; - if (tgtbitno < bitno) - continue; - incode = accm >> tgtbitno; - accm <<= n_bits; - bitno += n_bits; - - if (incode == CLEAR) { - /* - * The dictionary must only be cleared at - * the end of a packet. But there could be an - * empty message block at the end. - */ - if (len > 0) { - if (db->debug) - printf("bsd_decomp%d: bad CLEAR\n", db->unit); - return DECOMP_FATALERROR; - } - bsd_clear(db); - explen = ilen = 0; - break; - } - - if (incode > max_ent + 2 || incode > db->maxmaxcode - || incode > max_ent && oldcode == CLEAR) { - if (db->debug) { - printf("bsd_decomp%d: bad code 0x%x oldcode=0x%x ", - db->unit, incode, oldcode); - printf("max_ent=0x%x dlen=%d seqno=%d\n", - max_ent, dlen, db->seqno); - } - return DECOMP_FATALERROR; /* probably a bug */ - } - - /* Special case for KwKwK string. */ - if (incode > max_ent) { - finchar = oldcode; - extra = 1; - } else { - finchar = incode; - extra = 0; - } - - codelen = db->lens[finchar]; - explen += codelen + extra; - if (explen > db->mru + 1) { - if (db->debug) - printf("bsd_decomp%d: ran out of mru\n", db->unit); - return DECOMP_FATALERROR; - } - - /* - * Decode this code and install it in the decompressed buffer. - */ - p = (wptr += codelen); - while (finchar > LAST) { - dictp = &db->dict[db->dict[finchar].cptr]; -#ifdef DEBUG - --codelen; - if (codelen <= 0) { - printf("bsd_decomp%d: fell off end of chain ", db->unit); - printf("0x%x at 0x%x by 0x%x, max_ent=0x%x\n", - incode, finchar, db->dict[finchar].cptr, max_ent); - return DECOMP_FATALERROR; - } - if (dictp->codem1 != finchar-1) { - printf("bsd_decomp%d: bad code chain 0x%x finchar=0x%x ", - db->unit, incode, finchar); - printf("oldcode=0x%x cptr=0x%x codem1=0x%x\n", oldcode, - db->dict[finchar].cptr, dictp->codem1); - return DECOMP_FATALERROR; - } -#endif - *--p = dictp->f.hs.suffix; - finchar = dictp->f.hs.prefix; - } - *--p = finchar; - -#ifdef DEBUG - if (--codelen != 0) - printf("bsd_decomp%d: short by %d after code 0x%x, max_ent=0x%x\n", - db->unit, codelen, incode, max_ent); -#endif - - if (extra) /* the KwKwK case again */ - *wptr++ = finchar; - - /* - * If not first code in a packet, and - * if not out of code space, then allocate a new code. - * - * Keep the hash table correct so it can be used - * with uncompressed packets. - */ - if (oldcode != CLEAR && max_ent < db->maxmaxcode) { - struct bsd_dict *dictp2; - u_int32_t fcode; - int hval, disp; - - fcode = BSD_KEY(oldcode,finchar); - hval = BSD_HASH(oldcode,finchar,db->hshift); - dictp = &db->dict[hval]; - - /* look for a free hash table entry */ - if (dictp->codem1 < max_ent) { - disp = (hval == 0) ? 1 : hval; - do { - hval += disp; - if (hval >= db->hsize) - hval -= db->hsize; - dictp = &db->dict[hval]; - } while (dictp->codem1 < max_ent); - } - - /* - * Invalidate previous hash table entry - * assigned this code, and then take it over - */ - dictp2 = &db->dict[max_ent+1]; - if (db->dict[dictp2->cptr].codem1 == max_ent) { - db->dict[dictp2->cptr].codem1 = BADCODEM1; - } - dictp2->cptr = hval; - dictp->codem1 = max_ent; - dictp->f.fcode = fcode; - - db->max_ent = ++max_ent; - db->lens[max_ent] = db->lens[oldcode]+1; - - /* Expand code size if needed. */ - if (max_ent >= MAXCODE(n_bits) && max_ent < db->maxmaxcode) { - db->n_bits = ++n_bits; - tgtbitno = 32-n_bits; - } - } - oldcode = incode; - } - *outlenp = wptr - (dmp + db->hdrlen); - - /* - * Keep the checkpoint right so that incompressible packets - * clear the dictionary at the right times. - */ - db->bytes_out += ilen; - db->in_count += explen; - if (bsd_check(db) && db->debug) { - printf("bsd_decomp%d: peer should have cleared dictionary\n", - db->unit); - } - - ++db->comp_count; - db->comp_bytes += ilen + BSD_OVHD; - ++db->uncomp_count; - db->uncomp_bytes += explen; - - return DECOMP_OK; -} -#endif /* DO_BSD_COMPRESS */ |