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Diffstat (limited to 'mdk-stage1/ppp/pppdump/deflate.c')
-rw-r--r-- | mdk-stage1/ppp/pppdump/deflate.c | 344 |
1 files changed, 344 insertions, 0 deletions
diff --git a/mdk-stage1/ppp/pppdump/deflate.c b/mdk-stage1/ppp/pppdump/deflate.c new file mode 100644 index 000000000..08e8abc0d --- /dev/null +++ b/mdk-stage1/ppp/pppdump/deflate.c @@ -0,0 +1,344 @@ +/* + * ppp_deflate.c - interface the zlib procedures for Deflate compression + * and decompression (as used by gzip) to the PPP code. + * + * Copyright (c) 1994 The Australian National University. + * All rights reserved. + * + * Permission to use, copy, modify, and distribute this software and its + * documentation is hereby granted, provided that the above copyright + * notice appears in all copies. This software is provided without any + * warranty, express or implied. The Australian National University + * makes no representations about the suitability of this software for + * any purpose. + * + * IN NO EVENT SHALL THE AUSTRALIAN NATIONAL UNIVERSITY BE LIABLE TO ANY + * PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES + * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF + * THE AUSTRALIAN NATIONAL UNIVERSITY HAS BEEN ADVISED OF THE POSSIBILITY + * OF SUCH DAMAGE. + * + * THE AUSTRALIAN NATIONAL UNIVERSITY SPECIFICALLY DISCLAIMS ANY WARRANTIES, + * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY + * AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS + * ON AN "AS IS" BASIS, AND THE AUSTRALIAN NATIONAL UNIVERSITY HAS NO + * OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, + * OR MODIFICATIONS. + * + * $Id$ + */ + +#include <sys/types.h> +#include <stddef.h> +#include <stdlib.h> +#include "ppp_defs.h" +#include "ppp-comp.h" +#include "zlib.h" + +#if DO_DEFLATE + +#define DEFLATE_DEBUG 1 + +/* + * State for a Deflate (de)compressor. + */ +struct deflate_state { + int seqno; + int w_size; + int unit; + int hdrlen; + int mru; + int debug; + z_stream strm; + struct compstat stats; +}; + +#define DEFLATE_OVHD 2 /* Deflate overhead/packet */ + +static void *z_alloc __P((void *, u_int items, u_int size)); +static void z_free __P((void *, void *ptr, u_int nb)); +static void *z_decomp_alloc __P((u_char *options, int opt_len)); +static void z_decomp_free __P((void *state)); +static int z_decomp_init __P((void *state, u_char *options, int opt_len, + int unit, int hdrlen, int mru, int debug)); +static void z_incomp __P((void *state, u_char *dmsg, int len)); +static int z_decompress __P((void *state, u_char *cmp, int inlen, + u_char *dmp, int *outlenp)); +static void z_decomp_reset __P((void *state)); +static void z_comp_stats __P((void *state, struct compstat *stats)); + +/* + * Procedures exported to if_ppp.c. + */ +struct compressor ppp_deflate = { + CI_DEFLATE, /* compress_proto */ + z_decomp_alloc, /* decomp_alloc */ + z_decomp_free, /* decomp_free */ + z_decomp_init, /* decomp_init */ + z_decomp_reset, /* decomp_reset */ + z_decompress, /* decompress */ + z_incomp, /* incomp */ + z_comp_stats, /* decomp_stat */ +}; + +/* + * Space allocation and freeing routines for use by zlib routines. + */ +static void * +z_alloc(notused, items, size) + void *notused; + u_int items, size; +{ + return malloc(items * size); +} + +static void +z_free(notused, ptr, nbytes) + void *notused; + void *ptr; + u_int nbytes; +{ + free(ptr); +} + +static void +z_comp_stats(arg, stats) + void *arg; + struct compstat *stats; +{ + struct deflate_state *state = (struct deflate_state *) arg; + u_int out; + + *stats = state->stats; + stats->ratio = stats->unc_bytes; + out = stats->comp_bytes + stats->unc_bytes; + if (stats->ratio <= 0x7ffffff) + stats->ratio <<= 8; + else + out >>= 8; + if (out != 0) + stats->ratio /= out; +} + +/* + * Allocate space for a decompressor. + */ +static void * +z_decomp_alloc(options, opt_len) + u_char *options; + int opt_len; +{ + struct deflate_state *state; + int w_size; + + if (opt_len != CILEN_DEFLATE || options[0] != CI_DEFLATE + || options[1] != CILEN_DEFLATE + || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL + || options[3] != DEFLATE_CHK_SEQUENCE) + return NULL; + w_size = DEFLATE_SIZE(options[2]); + if (w_size < DEFLATE_MIN_SIZE || w_size > DEFLATE_MAX_SIZE) + return NULL; + + state = (struct deflate_state *) malloc(sizeof(*state)); + if (state == NULL) + return NULL; + + state->strm.next_out = NULL; + state->strm.zalloc = (alloc_func) z_alloc; + state->strm.zfree = (free_func) z_free; + if (inflateInit2(&state->strm, -w_size) != Z_OK) { + free(state); + return NULL; + } + + state->w_size = w_size; + memset(&state->stats, 0, sizeof(state->stats)); + return (void *) state; +} + +static void +z_decomp_free(arg) + void *arg; +{ + struct deflate_state *state = (struct deflate_state *) arg; + + inflateEnd(&state->strm); + free(state); +} + +static int +z_decomp_init(arg, options, opt_len, unit, hdrlen, mru, debug) + void *arg; + u_char *options; + int opt_len, unit, hdrlen, mru, debug; +{ + struct deflate_state *state = (struct deflate_state *) arg; + + if (opt_len < CILEN_DEFLATE || options[0] != CI_DEFLATE + || options[1] != CILEN_DEFLATE + || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL + || DEFLATE_SIZE(options[2]) != state->w_size + || options[3] != DEFLATE_CHK_SEQUENCE) + return 0; + + state->seqno = 0; + state->unit = unit; + state->hdrlen = hdrlen; + state->debug = debug; + state->mru = mru; + + inflateReset(&state->strm); + + return 1; +} + +static void +z_decomp_reset(arg) + void *arg; +{ + struct deflate_state *state = (struct deflate_state *) arg; + + state->seqno = 0; + inflateReset(&state->strm); +} + +/* + * Decompress a Deflate-compressed packet. + * + * 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 +z_decompress(arg, mi, inlen, mo, outlenp) + void *arg; + u_char *mi, *mo; + int inlen, *outlenp; +{ + struct deflate_state *state = (struct deflate_state *) arg; + u_char *rptr, *wptr; + int rlen, olen, ospace; + int seq, i, flush, r, decode_proto; + + rptr = mi; + if (*rptr == 0) + ++rptr; + ++rptr; + + /* Check the sequence number. */ + seq = (rptr[0] << 8) + rptr[1]; + rptr += 2; + if (seq != state->seqno) { +#if !DEFLATE_DEBUG + if (state->debug) +#endif + printf("z_decompress%d: bad seq # %d, expected %d\n", + state->unit, seq, state->seqno); + return DECOMP_ERROR; + } + ++state->seqno; + + /* + * Set up to call inflate. + */ + wptr = mo; + state->strm.next_in = rptr; + state->strm.avail_in = mi + inlen - rptr; + rlen = state->strm.avail_in + PPP_HDRLEN + DEFLATE_OVHD; + state->strm.next_out = wptr; + state->strm.avail_out = state->mru + 2; + + r = inflate(&state->strm, Z_PACKET_FLUSH); + if (r != Z_OK) { +#if !DEFLATE_DEBUG + if (state->debug) +#endif + printf("z_decompress%d: inflate returned %d (%s)\n", + state->unit, r, (state->strm.msg? state->strm.msg: "")); + return DECOMP_FATALERROR; + } + olen = state->mru + 2 - state->strm.avail_out; + *outlenp = olen; + + if ((wptr[0] & 1) != 0) + ++olen; /* for suppressed protocol high byte */ + olen += 2; /* for address, control */ + +#if DEFLATE_DEBUG + if (olen > state->mru + PPP_HDRLEN) + printf("ppp_deflate%d: exceeded mru (%d > %d)\n", + state->unit, olen, state->mru + PPP_HDRLEN); +#endif + + state->stats.unc_bytes += olen; + state->stats.unc_packets++; + state->stats.comp_bytes += rlen; + state->stats.comp_packets++; + + return DECOMP_OK; +} + +/* + * Incompressible data has arrived - add it to the history. + */ +static void +z_incomp(arg, mi, mlen) + void *arg; + u_char *mi; + int mlen; +{ + struct deflate_state *state = (struct deflate_state *) arg; + u_char *rptr; + int rlen, proto, r; + + /* + * Check that the protocol is one we handle. + */ + rptr = mi; + proto = rptr[0]; + if ((proto & 1) == 0) + proto = (proto << 8) + rptr[1]; + if (proto > 0x3fff || proto == 0xfd || proto == 0xfb) + return; + + ++state->seqno; + + if (rptr[0] == 0) + ++rptr; + rlen = mi + mlen - rptr; + state->strm.next_in = rptr; + state->strm.avail_in = rlen; + r = inflateIncomp(&state->strm); + if (r != Z_OK) { + /* gak! */ +#if !DEFLATE_DEBUG + if (state->debug) +#endif + printf("z_incomp%d: inflateIncomp returned %d (%s)\n", + state->unit, r, (state->strm.msg? state->strm.msg: "")); + return; + } + + /* + * Update stats. + */ + if (proto <= 0xff) + ++rlen; + rlen += 2; + state->stats.inc_bytes += rlen; + state->stats.inc_packets++; + state->stats.unc_bytes += rlen; + state->stats.unc_packets++; +} + +#endif /* DO_DEFLATE */ |