+++ /dev/null
-/*
- * 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: deflate.c,v 1.3 1999/04/16 11:35:59 paulus Exp $
- */
-
-#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 */
projects / ppp.git / blobdiff