NetBSD-5.0.2/dist/pppd/pppdump/deflate.c
/* $NetBSD: deflate.c,v 1.2 2005/02/20 10:47:17 cube Exp $ */
/*
* ppp_deflate.c - interface the zlib procedures for Deflate compression
* and decompression (as used by gzip) to the PPP code.
*
* Copyright (c) 1994 Paul Mackerras. All rights reserved.
*
* 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. The name(s) of the authors of this software must not be used to
* endorse or promote products derived from this software without
* prior written permission.
*
* 4. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by Paul Mackerras
* <paulus@samba.org>".
*
* THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO
* THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
* SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
* AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* Id: deflate.c,v 1.5 2004/01/17 05:47:55 carlsonj Exp
*/
#include <sys/types.h>
#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include "pppdump.h"
#include <net/ppp_defs.h>
#include <net/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, PACKETPTR mi));
static int z_decompress __P((void *state, PACKETPTR mi, PACKETPTR *mo));
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 */
NULL, /* comp_alloc */
NULL, /* comp_free */
NULL, /* comp_init */
NULL, /* comp_reset */
NULL, /* comp_compress */
NULL, /* comp_stat */
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, mo)
void *arg;
PACKETPTR mi;
PACKETPTR *mo;
{
struct deflate_state *state = (struct deflate_state *) arg;
u_char *rptr, *wptr;
int rlen, olen;
int seq, r;
rptr = mi->buf;
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)->buf;
state->strm.next_in = rptr;
state->strm.avail_in = mi->buf + mi->len - 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;
(*mo)->len = 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)
void *arg;
PACKETPTR mi;
{
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->buf;
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->buf + mi->len - 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 */