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/*
* ==FILEVERSION 980319==
*
* 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 Linux kernel 1.3.X.
*
* 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.
*
* From: deflate.c,v 1.1 1996/01/18 03:17:48 paulus Exp
*/
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/init.h>
#include <linux/ppp_defs.h>
#include <linux/ppp-comp.h>
#include "zlib.c"
/*
* State for a Deflate (de)compressor.
*/
struct ppp_deflate_state {
int seqno;
int w_size;
int unit;
int mru;
int debug;
z_stream strm;
struct compstat stats;
};
#define DEFLATE_OVHD 2 /* Deflate overhead/packet */
static void *zalloc __P((void *, unsigned int items, unsigned int size));
static void *zalloc_init __P((void *, unsigned int items,
unsigned int size));
static void zfree __P((void *, void *ptr));
static void *z_comp_alloc __P((unsigned char *options, int opt_len));
static void *z_decomp_alloc __P((unsigned 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, unsigned char *options,
int opt_len,
int unit, int hdrlen, int debug));
static int z_decomp_init __P((void *state, unsigned char *options,
int opt_len,
int unit, int hdrlen, int mru, int debug));
static int z_compress __P((void *state, unsigned char *rptr,
unsigned char *obuf,
int isize, int osize));
static void z_incomp __P((void *state, unsigned char *ibuf, int icnt));
static int z_decompress __P((void *state, unsigned char *ibuf,
int isize, unsigned char *obuf, int osize));
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));
struct chunk_header {
int valloced; /* allocated with valloc, not kmalloc */
int guard; /* check for overwritten header */
};
#define GUARD_MAGIC 0x77a8011a
#define MIN_VMALLOC 2048 /* use kmalloc for blocks < this */
/*
* Space allocation and freeing routines for use by zlib routines.
*/
void
zfree(arg, ptr)
void *arg;
void *ptr;
{
struct chunk_header *hdr = ((struct chunk_header *)ptr) - 1;
if (hdr->guard != GUARD_MAGIC) {
printk(KERN_WARNING "zfree: header corrupted (%x %x) at %p\n",
hdr->valloced, hdr->guard, hdr);
return;
}
if (hdr->valloced)
vfree(hdr);
else
kfree(hdr);
}
void *
zalloc(arg, items, size)
void *arg;
unsigned int items, size;
{
struct chunk_header *hdr;
unsigned nbytes;
nbytes = items * size + sizeof(*hdr);
hdr = kmalloc(nbytes, GFP_ATOMIC);
if (hdr == 0)
return 0;
hdr->valloced = 0;
hdr->guard = GUARD_MAGIC;
return (void *) (hdr + 1);
}
void *
zalloc_init(arg, items, size)
void *arg;
unsigned int items, size;
{
struct chunk_header *hdr;
unsigned nbytes;
nbytes = items * size + sizeof(*hdr);
if (nbytes >= MIN_VMALLOC)
hdr = vmalloc(nbytes);
else
hdr = kmalloc(nbytes, GFP_KERNEL);
if (hdr == 0)
return 0;
hdr->valloced = nbytes >= MIN_VMALLOC;
hdr->guard = GUARD_MAGIC;
return (void *) (hdr + 1);
}
static void
z_comp_free(arg)
void *arg;
{
struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
if (state) {
deflateEnd(&state->strm);
kfree(state);
MOD_DEC_USE_COUNT;
}
}
/*
* Allocate space for a compressor.
*/
static void *
z_comp_alloc(options, opt_len)
unsigned char *options;
int opt_len;
{
struct ppp_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;
state = (struct ppp_deflate_state *) kmalloc(sizeof(*state), GFP_KERNEL);
if (state == NULL)
return NULL;
MOD_INC_USE_COUNT;
memset (state, 0, sizeof (struct ppp_deflate_state));
state->strm.next_in = NULL;
state->strm.zalloc = zalloc_init;
state->strm.zfree = zfree;
state->w_size = w_size;
if (deflateInit2(&state->strm, Z_DEFAULT_COMPRESSION,
DEFLATE_METHOD_VAL, -w_size, 8, Z_DEFAULT_STRATEGY)
!= Z_OK)
goto out_free;
state->strm.zalloc = zalloc;
return (void *) state;
out_free:
z_comp_free(state);
MOD_DEC_USE_COUNT;
return NULL;
}
static int
z_comp_init(arg, options, opt_len, unit, hdrlen, debug)
void *arg;
unsigned char *options;
int opt_len, unit, hdrlen, debug;
{
struct ppp_deflate_state *state = (struct ppp_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->debug = debug;
deflateReset(&state->strm);
return 1;
}
static void
z_comp_reset(arg)
void *arg;
{
struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
state->seqno = 0;
deflateReset(&state->strm);
}
int
z_compress(arg, rptr, obuf, isize, osize)
void *arg;
unsigned char *rptr; /* uncompressed packet (in) */
unsigned char *obuf; /* compressed packet (out) */
int isize, osize;
{
struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
int r, proto, off, olen, oavail;
unsigned char *wptr;
/*
* Check that the protocol is in the range we handle.
*/
proto = PPP_PROTOCOL(rptr);
if (proto > 0x3fff || proto == 0xfd || proto == 0xfb)
return 0;
/* Don't generate compressed packets which are larger than
the uncompressed packet. */
if (osize > isize)
osize = isize;
wptr = obuf;
/*
* 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 += DEFLATE_OVHD;
olen = PPP_HDRLEN + DEFLATE_OVHD;
state->strm.next_out = wptr;
state->strm.avail_out = oavail = osize - olen;
++state->seqno;
off = (proto > 0xff) ? 2 : 3; /* skip 1st proto byte if 0 */
rptr += off;
state->strm.next_in = rptr;
state->strm.avail_in = (isize - off);
for (;;) {
r = deflate(&state->strm, Z_PACKET_FLUSH);
if (r != Z_OK) {
if (state->debug)
printk(KERN_ERR
"z_compress: deflate returned %d\n", r);
break;
}
if (state->strm.avail_out == 0) {
olen += oavail;
state->strm.next_out = NULL;
state->strm.avail_out = oavail = 1000000;
} else {
break; /* all done */
}
}
olen += oavail - state->strm.avail_out;
/*
* See if we managed to reduce the size of the packet.
*/
if (olen < isize) {
state->stats.comp_bytes += olen;
state->stats.comp_packets++;
} else {
state->stats.inc_bytes += isize;
state->stats.inc_packets++;
olen = 0;
}
state->stats.unc_bytes += isize;
state->stats.unc_packets++;
return olen;
}
static void
z_comp_stats(arg, stats)
void *arg;
struct compstat *stats;
{
struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
*stats = state->stats;
}
static void
z_decomp_free(arg)
void *arg;
{
struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
if (state) {
inflateEnd(&state->strm);
kfree(state);
MOD_DEC_USE_COUNT;
}
}
/*
* Allocate space for a decompressor.
*/
static void *
z_decomp_alloc(options, opt_len)
unsigned char *options;
int opt_len;
{
struct ppp_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;
state = (struct ppp_deflate_state *) kmalloc(sizeof(*state), GFP_KERNEL);
if (state == NULL)
return NULL;
MOD_INC_USE_COUNT;
memset (state, 0, sizeof (struct ppp_deflate_state));
state->w_size = w_size;
state->strm.next_out = NULL;
state->strm.zalloc = zalloc_init;
state->strm.zfree = zfree;
if (inflateInit2(&state->strm, -w_size) != Z_OK)
goto out_free;
state->strm.zalloc = zalloc;
return (void *) state;
out_free:
z_decomp_free(state);
MOD_DEC_USE_COUNT;
return NULL;
}
static int
z_decomp_init(arg, options, opt_len, unit, hdrlen, mru, debug)
void *arg;
unsigned char *options;
int opt_len, unit, hdrlen, mru, debug;
{
struct ppp_deflate_state *state = (struct ppp_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->debug = debug;
state->mru = mru;
inflateReset(&state->strm);
return 1;
}
static void
z_decomp_reset(arg)
void *arg;
{
struct ppp_deflate_state *state = (struct ppp_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, ibuf, isize, obuf, osize)
void *arg;
unsigned char *ibuf;
int isize;
unsigned char *obuf;
int osize;
{
struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
int olen, seq, r;
int decode_proto, overflow;
unsigned char overflow_buf[1];
if (isize <= PPP_HDRLEN + DEFLATE_OVHD) {
if (state->debug)
printk(KERN_DEBUG "z_decompress%d: short pkt (%d)\n",
state->unit, isize);
return DECOMP_ERROR;
}
/* Check the sequence number. */
seq = (ibuf[PPP_HDRLEN] << 8) + ibuf[PPP_HDRLEN+1];
if (seq != state->seqno) {
if (state->debug)
printk(KERN_DEBUG "z_decompress%d: bad seq # %d, expected %d\n",
state->unit, seq, state->seqno);
return DECOMP_ERROR;
}
++state->seqno;
/*
* Fill in the first part of the PPP header. The protocol field
* comes from the decompressed data.
*/
obuf[0] = PPP_ADDRESS(ibuf);
obuf[1] = PPP_CONTROL(ibuf);
obuf[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 = ibuf + PPP_HDRLEN + DEFLATE_OVHD;
state->strm.avail_in = isize - (PPP_HDRLEN + DEFLATE_OVHD);
state->strm.next_out = obuf + 3;
state->strm.avail_out = 1;
decode_proto = 1;
overflow = 0;
/*
* Call inflate, supplying more input or output as needed.
*/
for (;;) {
r = inflate(&state->strm, Z_PACKET_FLUSH);
if (r != Z_OK) {
if (state->debug)
printk(KERN_DEBUG "z_decompress%d: inflate returned %d (%s)\n",
state->unit, r, (state->strm.msg? state->strm.msg: ""));
return DECOMP_FATALERROR;
}
if (state->strm.avail_out != 0)
break; /* all done */
if (decode_proto) {
state->strm.avail_out = osize - PPP_HDRLEN;
if ((obuf[3] & 1) == 0) {
/* 2-byte protocol field */
obuf[2] = obuf[3];
--state->strm.next_out;
++state->strm.avail_out;
}
decode_proto = 0;
} else if (!overflow) {
/*
* We've filled up the output buffer; the only way to
* find out whether inflate has any more characters
* left is to give it another byte of output space.
*/
state->strm.next_out = overflow_buf;
state->strm.avail_out = 1;
overflow = 1;
} else {
if (state->debug)
printk(KERN_DEBUG "z_decompress%d: ran out of mru\n",
state->unit);
return DECOMP_FATALERROR;
}
}
if (decode_proto) {
if (state->debug)
printk(KERN_DEBUG "z_decompress%d: didn't get proto\n",
state->unit);
return DECOMP_ERROR;
}
olen = osize + overflow - state->strm.avail_out;
state->stats.unc_bytes += olen;
state->stats.unc_packets++;
state->stats.comp_bytes += isize;
state->stats.comp_packets++;
return olen;
}
/*
* Incompressible data has arrived - add it to the history.
*/
static void
z_incomp(arg, ibuf, icnt)
void *arg;
unsigned char *ibuf;
int icnt;
{
struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
int proto, r;
/*
* Check that the protocol is one we handle.
*/
proto = PPP_PROTOCOL(ibuf);
if (proto > 0x3fff || proto == 0xfd || proto == 0xfb)
return;
++state->seqno;
/*
* We start at the either the 1st or 2nd byte of the protocol field,
* depending on whether the protocol value is compressible.
*/
state->strm.next_in = ibuf + 3;
state->strm.avail_in = icnt - 3;
if (proto > 0xff) {
--state->strm.next_in;
++state->strm.avail_in;
}
r = inflateIncomp(&state->strm);
if (r != Z_OK) {
/* gak! */
if (state->debug) {
printk(KERN_DEBUG "z_incomp%d: inflateIncomp returned %d (%s)\n",
state->unit, r, (state->strm.msg? state->strm.msg: ""));
}
return;
}
/*
* Update stats.
*/
state->stats.inc_bytes += icnt;
state->stats.inc_packets++;
state->stats.unc_bytes += icnt;
state->stats.unc_packets++;
}
/*************************************************************
* Module interface table
*************************************************************/
/* These are in ppp_generic.c */
extern int ppp_register_compressor (struct compressor *cp);
extern void ppp_unregister_compressor (struct compressor *cp);
/*
* 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 */
};
int __init deflate_init(void)
{
int answer = ppp_register_compressor(&ppp_deflate);
if (answer == 0)
printk(KERN_INFO
"PPP Deflate Compression module registered\n");
ppp_register_compressor(&ppp_deflate_draft);
return answer;
}
void __exit deflate_cleanup(void)
{
ppp_unregister_compressor(&ppp_deflate);
ppp_unregister_compressor(&ppp_deflate_draft);
}
module_init(deflate_init);
module_exit(deflate_cleanup);
MODULE_LICENSE("BSD without advertisement clause");
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