drakx-backup-do-not-use - Mageia Installer and base platform for many utilities

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Commits per author per week (path 'tools/i386/netboot/exos205')

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/* 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 */


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