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freebsd/sys/net/ppp_deflate.c

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18 KiB
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1999-08-28 01:08:13 +00:00
/* $FreeBSD$ */
/*
* 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 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.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.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 *z_alloc __P((void *, u_int items, u_int size));
static void z_free __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_draft = {
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 *
z_alloc(notused, items, size)
void *notused;
u_int items, size;
{
void *ptr;
MALLOC(ptr, void *, items * size, M_DEVBUF, M_NOWAIT);
return ptr;
}
void
z_free(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 = z_alloc;
state->strm.zfree = z_free;
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 (m != NULL && olen < orig_len) {
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 = z_alloc;
state->strm.zfree = z_free;
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 (state->debug && 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 */