+++ /dev/null
-/* $Id: ppp-deflate.c,v 1.9 2002/12/06 09:49:16 paulus Exp $ */
-
-/*
- * ppp_deflate.c - interface the zlib procedures for Deflate compression
- * and decompression (as used by gzip) to the PPP code.
- * This version is for use with mbufs on BSD-derived systems.
- *
- * 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.
- */
-
-#include <sys/param.h>
-#include <sys/types.h>
-#include <sys/systm.h>
-#include <sys/mbuf.h>
-#include <net/ppp_defs.h>
-#include <net/zlib.h>
-
-#define PACKETPTR struct mbuf *
-#include <net/ppp-comp.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 *zalloc __P((void *, u_int items, u_int size));
-static void zfree __P((void *, void *ptr));
-static void *z_comp_alloc __P((u_char *options, int opt_len));
-static void *z_decomp_alloc __P((u_char *options, int opt_len));
-static void z_comp_free __P((void *state));
-static void z_decomp_free __P((void *state));
-static int z_comp_init __P((void *state, u_char *options, int opt_len,
- int unit, int hdrlen, int debug));
-static int z_decomp_init __P((void *state, u_char *options, int opt_len,
- int unit, int hdrlen, int mru, int debug));
-static int z_compress __P((void *state, struct mbuf **mret,
- struct mbuf *mp, int slen, int maxolen));
-static void z_incomp __P((void *state, struct mbuf *dmsg));
-static int z_decompress __P((void *state, struct mbuf *cmp,
- struct mbuf **dmpp));
-static void z_comp_reset __P((void *state));
-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_comp_alloc, /* comp_alloc */
- z_comp_free, /* comp_free */
- z_comp_init, /* comp_init */
- z_comp_reset, /* comp_reset */
- z_compress, /* compress */
- z_comp_stats, /* 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 */
-};
-
-struct compressor ppp_deflate = {
- CI_DEFLATE_DRAFT, /* compress_proto */
- z_comp_alloc, /* comp_alloc */
- z_comp_free, /* comp_free */
- z_comp_init, /* comp_init */
- z_comp_reset, /* comp_reset */
- z_compress, /* compress */
- z_comp_stats, /* 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.
- */
-void *
-zalloc(notused, items, size)
- void *notused;
- u_int items, size;
-{
- void *ptr;
-
- MALLOC(ptr, void *, items * size, M_DEVBUF, M_NOWAIT);
- return ptr;
-}
-
-void
-zfree(notused, ptr)
- void *notused;
- void *ptr;
-{
- FREE(ptr, M_DEVBUF);
-}
-
-/*
- * Allocate space for a compressor.
- */
-static void *
-z_comp_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[0] != CI_DEFLATE_DRAFT)
- || 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;
-
- MALLOC(state, struct deflate_state *, sizeof(struct deflate_state),
- M_DEVBUF, M_NOWAIT);
- if (state == NULL)
- return NULL;
-
- state->strm.next_in = NULL;
- state->strm.zalloc = zalloc;
- state->strm.zfree = zfree;
- if (deflateInit2(&state->strm, Z_DEFAULT_COMPRESSION, DEFLATE_METHOD_VAL,
- -w_size, 8, Z_DEFAULT_STRATEGY) != Z_OK) {
- FREE(state, M_DEVBUF);
- return NULL;
- }
-
- state->w_size = w_size;
- bzero(&state->stats, sizeof(state->stats));
- return (void *) state;
-}
-
-static void
-z_comp_free(arg)
- void *arg;
-{
- struct deflate_state *state = (struct deflate_state *) arg;
-
- deflateEnd(&state->strm);
- FREE(state, M_DEVBUF);
-}
-
-static int
-z_comp_init(arg, options, opt_len, unit, hdrlen, debug)
- void *arg;
- u_char *options;
- int opt_len, unit, hdrlen, debug;
-{
- struct deflate_state *state = (struct deflate_state *) arg;
-
- if (opt_len < CILEN_DEFLATE
- || (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT)
- || 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;
-
- deflateReset(&state->strm);
-
- return 1;
-}
-
-static void
-z_comp_reset(arg)
- void *arg;
-{
- struct deflate_state *state = (struct deflate_state *) arg;
-
- state->seqno = 0;
- deflateReset(&state->strm);
-}
-
-int
-z_compress(arg, mret, mp, orig_len, maxolen)
- void *arg;
- struct mbuf **mret; /* compressed packet (out) */
- struct mbuf *mp; /* uncompressed packet (in) */
- int orig_len, maxolen;
-{
- struct deflate_state *state = (struct deflate_state *) arg;
- u_char *rptr, *wptr;
- int proto, olen, wspace, r, flush;
- struct mbuf *m;
-
- /*
- * Check that the protocol is in the range we handle.
- */
- rptr = mtod(mp, u_char *);
- proto = PPP_PROTOCOL(rptr);
- if (proto > 0x3fff || proto == 0xfd || proto == 0xfb) {
- *mret = NULL;
- return orig_len;
- }
-
- /* Allocate one mbuf initially. */
- if (maxolen > orig_len)
- maxolen = orig_len;
- MGET(m, M_DONTWAIT, MT_DATA);
- *mret = m;
- if (m != NULL) {
- m->m_len = 0;
- if (maxolen + state->hdrlen > MLEN)
- MCLGET(m, M_DONTWAIT);
- wspace = M_TRAILINGSPACE(m);
- if (state->hdrlen + PPP_HDRLEN + 2 < wspace) {
- m->m_data += state->hdrlen;
- wspace -= state->hdrlen;
- }
- wptr = mtod(m, u_char *);
-
- /*
- * Copy over the PPP header and store the 2-byte sequence number.
- */
- wptr[0] = PPP_ADDRESS(rptr);
- wptr[1] = PPP_CONTROL(rptr);
- wptr[2] = PPP_COMP >> 8;
- wptr[3] = PPP_COMP;
- wptr += PPP_HDRLEN;
- wptr[0] = state->seqno >> 8;
- wptr[1] = state->seqno;
- wptr += 2;
- state->strm.next_out = wptr;
- state->strm.avail_out = wspace - (PPP_HDRLEN + 2);
- } else {
- state->strm.next_out = NULL;
- state->strm.avail_out = 1000000;
- wptr = NULL;
- wspace = 0;
- }
- ++state->seqno;
-
- rptr += (proto > 0xff)? 2: 3; /* skip 1st proto byte if 0 */
- state->strm.next_in = rptr;
- state->strm.avail_in = mtod(mp, u_char *) + mp->m_len - rptr;
- mp = mp->m_next;
- flush = (mp == NULL)? Z_PACKET_FLUSH: Z_NO_FLUSH;
- olen = 0;
- for (;;) {
- r = deflate(&state->strm, flush);
- if (r != Z_OK) {
- printf("z_compress: deflate returned %d (%s)\n",
- r, (state->strm.msg? state->strm.msg: ""));
- break;
- }
- if (flush != Z_NO_FLUSH && state->strm.avail_out != 0)
- break; /* all done */
- if (state->strm.avail_in == 0 && mp != NULL) {
- state->strm.next_in = mtod(mp, u_char *);
- state->strm.avail_in = mp->m_len;
- mp = mp->m_next;
- if (mp == NULL)
- flush = Z_PACKET_FLUSH;
- }
- if (state->strm.avail_out == 0) {
- if (m != NULL) {
- m->m_len = wspace;
- olen += wspace;
- MGET(m->m_next, M_DONTWAIT, MT_DATA);
- m = m->m_next;
- if (m != NULL) {
- m->m_len = 0;
- if (maxolen - olen > MLEN)
- MCLGET(m, M_DONTWAIT);
- state->strm.next_out = mtod(m, u_char *);
- state->strm.avail_out = wspace = M_TRAILINGSPACE(m);
- }
- }
- if (m == NULL) {
- state->strm.next_out = NULL;
- state->strm.avail_out = 1000000;
- }
- }
- }
- if (m != NULL)
- olen += (m->m_len = wspace - state->strm.avail_out);
-
- /*
- * See if we managed to reduce the size of the packet.
- * If the compressor just gave us a single zero byte, it means
- * the packet was incompressible.
- */
- if (m != NULL && olen < orig_len
- && !(olen == PPP_HDRLEN + 3 && *wptr == 0)) {
- state->stats.comp_bytes += olen;
- state->stats.comp_packets++;
- } else {
- if (*mret != NULL) {
- m_freem(*mret);
- *mret = NULL;
- }
- state->stats.inc_bytes += orig_len;
- state->stats.inc_packets++;
- olen = orig_len;
- }
- state->stats.unc_bytes += orig_len;
- state->stats.unc_packets++;
-
- return olen;
-}
-
-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->inc_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[0] != CI_DEFLATE_DRAFT)
- || 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;
-
- MALLOC(state, struct deflate_state *, sizeof(struct deflate_state),
- M_DEVBUF, M_NOWAIT);
- if (state == NULL)
- return NULL;
-
- state->strm.next_out = NULL;
- state->strm.zalloc = zalloc;
- state->strm.zfree = zfree;
- if (inflateInit2(&state->strm, -w_size) != Z_OK) {
- FREE(state, M_DEVBUF);
- return NULL;
- }
-
- state->w_size = w_size;
- bzero(&state->stats, 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, M_DEVBUF);
-}
-
-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[0] != CI_DEFLATE_DRAFT)
- || 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.
- */
-int
-z_decompress(arg, mi, mop)
- void *arg;
- struct mbuf *mi, **mop;
-{
- struct deflate_state *state = (struct deflate_state *) arg;
- struct mbuf *mo, *mo_head;
- u_char *rptr, *wptr;
- int rlen, olen, ospace;
- int seq, i, flush, r, decode_proto;
- u_char hdr[PPP_HDRLEN + DEFLATE_OVHD];
-
- *mop = NULL;
- rptr = mtod(mi, u_char *);
- rlen = mi->m_len;
- for (i = 0; i < PPP_HDRLEN + DEFLATE_OVHD; ++i) {
- while (rlen <= 0) {
- mi = mi->m_next;
- if (mi == NULL)
- return DECOMP_ERROR;
- rptr = mtod(mi, u_char *);
- rlen = mi->m_len;
- }
- hdr[i] = *rptr++;
- --rlen;
- }
-
- /* Check the sequence number. */
- seq = (hdr[PPP_HDRLEN] << 8) + hdr[PPP_HDRLEN+1];
- if (seq != state->seqno) {
- if (state->debug)
- printf("z_decompress%d: bad seq # %d, expected %d\n",
- state->unit, seq, state->seqno);
- return DECOMP_ERROR;
- }
- ++state->seqno;
-
- /* Allocate an output mbuf. */
- MGETHDR(mo, M_DONTWAIT, MT_DATA);
- if (mo == NULL)
- return DECOMP_ERROR;
- mo_head = mo;
- mo->m_len = 0;
- mo->m_next = NULL;
- MCLGET(mo, M_DONTWAIT);
- ospace = M_TRAILINGSPACE(mo);
- if (state->hdrlen + PPP_HDRLEN < ospace) {
- mo->m_data += state->hdrlen;
- ospace -= state->hdrlen;
- }
-
- /*
- * Fill in the first part of the PPP header. The protocol field
- * comes from the decompressed data.
- */
- wptr = mtod(mo, u_char *);
- wptr[0] = PPP_ADDRESS(hdr);
- wptr[1] = PPP_CONTROL(hdr);
- wptr[2] = 0;
-
- /*
- * Set up to call inflate. We set avail_out to 1 initially so we can
- * look at the first byte of the output and decide whether we have
- * a 1-byte or 2-byte protocol field.
- */
- state->strm.next_in = rptr;
- state->strm.avail_in = rlen;
- mi = mi->m_next;
- flush = (mi == NULL)? Z_PACKET_FLUSH: Z_NO_FLUSH;
- rlen += PPP_HDRLEN + DEFLATE_OVHD;
- state->strm.next_out = wptr + 3;
- state->strm.avail_out = 1;
- decode_proto = 1;
- olen = PPP_HDRLEN;
-
- /*
- * Call inflate, supplying more input or output as needed.
- */
- for (;;) {
- r = inflate(&state->strm, 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: ""));
- m_freem(mo_head);
- return DECOMP_FATALERROR;
- }
- if (flush != Z_NO_FLUSH && state->strm.avail_out != 0)
- break; /* all done */
- if (state->strm.avail_in == 0 && mi != NULL) {
- state->strm.next_in = mtod(mi, u_char *);
- state->strm.avail_in = mi->m_len;
- rlen += mi->m_len;
- mi = mi->m_next;
- if (mi == NULL)
- flush = Z_PACKET_FLUSH;
- }
- if (state->strm.avail_out == 0) {
- if (decode_proto) {
- state->strm.avail_out = ospace - PPP_HDRLEN;
- if ((wptr[3] & 1) == 0) {
- /* 2-byte protocol field */
- wptr[2] = wptr[3];
- --state->strm.next_out;
- ++state->strm.avail_out;
- --olen;
- }
- decode_proto = 0;
- } else {
- mo->m_len = ospace;
- olen += ospace;
- MGET(mo->m_next, M_DONTWAIT, MT_DATA);
- mo = mo->m_next;
- if (mo == NULL) {
- m_freem(mo_head);
- return DECOMP_ERROR;
- }
- MCLGET(mo, M_DONTWAIT);
- state->strm.next_out = mtod(mo, u_char *);
- state->strm.avail_out = ospace = M_TRAILINGSPACE(mo);
- }
- }
- }
- if (decode_proto) {
- m_freem(mo_head);
- return DECOMP_ERROR;
- }
- olen += (mo->m_len = ospace - state->strm.avail_out);
-#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++;
-
- *mop = mo_head;
- return DECOMP_OK;
-}
-
-/*
- * Incompressible data has arrived - add it to the history.
- */
-static void
-z_incomp(arg, mi)
- void *arg;
- struct mbuf *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 = mtod(mi, u_char *);
- proto = PPP_PROTOCOL(rptr);
- if (proto > 0x3fff || proto == 0xfd || proto == 0xfb)
- return;
-
- ++state->seqno;
-
- /*
- * Iterate through the mbufs, adding the characters in them
- * to the decompressor's history. For the first mbuf, we start
- * at the either the 1st or 2nd byte of the protocol field,
- * depending on whether the protocol value is compressible.
- */
- rlen = mi->m_len;
- state->strm.next_in = rptr + 3;
- state->strm.avail_in = rlen - 3;
- if (proto > 0xff) {
- --state->strm.next_in;
- ++state->strm.avail_in;
- }
- for (;;) {
- 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;
- }
- mi = mi->m_next;
- if (mi == NULL)
- break;
- state->strm.next_in = mtod(mi, u_char *);
- state->strm.avail_in = mi->m_len;
- rlen += mi->m_len;
- }
-
- /*
- * Update stats.
- */
- 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