FreeBSD-5.3/usr.sbin/ppp/deflate.c
/*-
* Copyright (c) 1997 Brian Somers <brian@Awfulhak.org>
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD: src/usr.sbin/ppp/deflate.c,v 1.25 2002/06/12 00:33:17 brian Exp $
*/
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <zlib.h>
#include "mbuf.h"
#include "log.h"
#include "timer.h"
#include "fsm.h"
#include "ccp.h"
#include "deflate.h"
/* Our state */
struct deflate_state {
u_short seqno;
int uncomp_rec;
int winsize;
z_stream cx;
};
static char garbage[10];
static u_char EMPTY_BLOCK[4] = { 0x00, 0x00, 0xff, 0xff };
#define DEFLATE_CHUNK_LEN (1536 - sizeof(struct mbuf))
static int
DeflateResetOutput(void *v)
{
struct deflate_state *state = (struct deflate_state *)v;
state->seqno = 0;
state->uncomp_rec = 0;
deflateReset(&state->cx);
log_Printf(LogCCP, "Deflate: Output channel reset\n");
return 1; /* Ask FSM to ACK */
}
static struct mbuf *
DeflateOutput(void *v, struct ccp *ccp, struct link *l, int pri, u_short *proto,
struct mbuf *mp)
{
struct deflate_state *state = (struct deflate_state *)v;
u_char *wp, *rp;
int olen, ilen, len, res, flush;
struct mbuf *mo_head, *mo, *mi_head, *mi;
ilen = m_length(mp);
log_Printf(LogDEBUG, "DeflateOutput: Proto %02x (%d bytes)\n", *proto, ilen);
log_DumpBp(LogDEBUG, "DeflateOutput: Compress packet:", mp);
/* Stuff the protocol in front of the input */
mi_head = mi = m_get(2, MB_CCPOUT);
mi->m_next = mp;
rp = MBUF_CTOP(mi);
if (*proto < 0x100) { /* Compress the protocol */
rp[0] = *proto & 0377;
mi->m_len = 1;
} else { /* Don't compress the protocol */
rp[0] = *proto >> 8;
rp[1] = *proto & 0377;
mi->m_len = 2;
}
/* Allocate the initial output mbuf */
mo_head = mo = m_get(DEFLATE_CHUNK_LEN, MB_CCPOUT);
mo->m_len = 2;
wp = MBUF_CTOP(mo);
*wp++ = state->seqno >> 8;
*wp++ = state->seqno & 0377;
log_Printf(LogDEBUG, "DeflateOutput: Seq %d\n", state->seqno);
state->seqno++;
/* Set up the deflation context */
state->cx.next_out = wp;
state->cx.avail_out = DEFLATE_CHUNK_LEN - 2;
state->cx.next_in = MBUF_CTOP(mi);
state->cx.avail_in = mi->m_len;
flush = Z_NO_FLUSH;
olen = 0;
while (1) {
if ((res = deflate(&state->cx, flush)) != Z_OK) {
if (res == Z_STREAM_END)
break; /* Done */
log_Printf(LogWARN, "DeflateOutput: deflate returned %d (%s)\n",
res, state->cx.msg ? state->cx.msg : "");
m_freem(mo_head);
m_free(mi_head);
state->seqno--;
return mp; /* Our dictionary's probably dead now :-( */
}
if (flush == Z_SYNC_FLUSH && state->cx.avail_out != 0)
break;
if (state->cx.avail_in == 0 && mi->m_next != NULL) {
mi = mi->m_next;
state->cx.next_in = MBUF_CTOP(mi);
state->cx.avail_in = mi->m_len;
if (mi->m_next == NULL)
flush = Z_SYNC_FLUSH;
}
if (state->cx.avail_out == 0) {
mo->m_next = m_get(DEFLATE_CHUNK_LEN, MB_CCPOUT);
olen += (mo->m_len = DEFLATE_CHUNK_LEN);
mo = mo->m_next;
mo->m_len = 0;
state->cx.next_out = MBUF_CTOP(mo);
state->cx.avail_out = DEFLATE_CHUNK_LEN;
}
}
olen += (mo->m_len = DEFLATE_CHUNK_LEN - state->cx.avail_out);
olen -= 4; /* exclude the trailing EMPTY_BLOCK */
/*
* If the output packet (including seqno and excluding the EMPTY_BLOCK)
* got bigger, send the original.
*/
if (olen >= ilen) {
m_freem(mo_head);
m_free(mi_head);
log_Printf(LogDEBUG, "DeflateOutput: %d => %d: Uncompressible (0x%04x)\n",
ilen, olen, *proto);
ccp->uncompout += ilen;
ccp->compout += ilen; /* We measure this stuff too */
return mp;
}
m_freem(mi_head);
/*
* Lose the last four bytes of our output.
* XXX: We should probably assert that these are the same as the
* contents of EMPTY_BLOCK.
*/
mo = mo_head;
for (len = mo->m_len; len < olen; mo = mo->m_next, len += mo->m_len)
;
mo->m_len -= len - olen;
if (mo->m_next != NULL) {
m_freem(mo->m_next);
mo->m_next = NULL;
}
ccp->uncompout += ilen;
ccp->compout += olen;
log_Printf(LogDEBUG, "DeflateOutput: %d => %d bytes, proto 0x%04x\n",
ilen, olen, *proto);
*proto = ccp_Proto(ccp);
return mo_head;
}
static void
DeflateResetInput(void *v)
{
struct deflate_state *state = (struct deflate_state *)v;
state->seqno = 0;
state->uncomp_rec = 0;
inflateReset(&state->cx);
log_Printf(LogCCP, "Deflate: Input channel reset\n");
}
static struct mbuf *
DeflateInput(void *v, struct ccp *ccp, u_short *proto, struct mbuf *mi)
{
struct deflate_state *state = (struct deflate_state *)v;
struct mbuf *mo, *mo_head, *mi_head;
u_char *wp;
int ilen, olen;
int seq, flush, res, first;
u_char hdr[2];
log_DumpBp(LogDEBUG, "DeflateInput: Decompress packet:", mi);
mi_head = mi = mbuf_Read(mi, hdr, 2);
ilen = 2;
/* Check the sequence number. */
seq = (hdr[0] << 8) + hdr[1];
log_Printf(LogDEBUG, "DeflateInput: Seq %d\n", seq);
if (seq != state->seqno) {
if (seq <= state->uncomp_rec)
/*
* So the peer's started at zero again - fine ! If we're wrong,
* inflate() will fail. This is better than getting into a loop
* trying to get a ResetReq to a busy sender.
*/
state->seqno = seq;
else {
log_Printf(LogCCP, "DeflateInput: Seq error: Got %d, expected %d\n",
seq, state->seqno);
m_freem(mi_head);
ccp_SendResetReq(&ccp->fsm);
return NULL;
}
}
state->seqno++;
state->uncomp_rec = 0;
/* Allocate an output mbuf */
mo_head = mo = m_get(DEFLATE_CHUNK_LEN, MB_CCPIN);
/* Our proto starts with 0 if it's compressed */
wp = MBUF_CTOP(mo);
wp[0] = '\0';
/*
* We set avail_out to 1 initially so we can look at the first
* byte of the output and decide whether we have a compressed
* proto field.
*/
state->cx.next_in = MBUF_CTOP(mi);
state->cx.avail_in = mi->m_len;
state->cx.next_out = wp + 1;
state->cx.avail_out = 1;
ilen += mi->m_len;
flush = mi->m_next ? Z_NO_FLUSH : Z_SYNC_FLUSH;
first = 1;
olen = 0;
while (1) {
if ((res = inflate(&state->cx, flush)) != Z_OK) {
if (res == Z_STREAM_END)
break; /* Done */
log_Printf(LogCCP, "DeflateInput: inflate returned %d (%s)\n",
res, state->cx.msg ? state->cx.msg : "");
m_freem(mo_head);
m_freem(mi);
ccp_SendResetReq(&ccp->fsm);
return NULL;
}
if (flush == Z_SYNC_FLUSH && state->cx.avail_out != 0)
break;
if (state->cx.avail_in == 0 && mi && (mi = m_free(mi)) != NULL) {
/* underflow */
state->cx.next_in = MBUF_CTOP(mi);
ilen += (state->cx.avail_in = mi->m_len);
if (mi->m_next == NULL)
flush = Z_SYNC_FLUSH;
}
if (state->cx.avail_out == 0) {
/* overflow */
if (first) {
if (!(wp[1] & 1)) {
/* 2 byte proto, shuffle it back in output */
wp[0] = wp[1];
state->cx.next_out--;
state->cx.avail_out = DEFLATE_CHUNK_LEN-1;
} else
state->cx.avail_out = DEFLATE_CHUNK_LEN-2;
first = 0;
} else {
olen += (mo->m_len = DEFLATE_CHUNK_LEN);
mo->m_next = m_get(DEFLATE_CHUNK_LEN, MB_CCPIN);
mo = mo->m_next;
state->cx.next_out = MBUF_CTOP(mo);
state->cx.avail_out = DEFLATE_CHUNK_LEN;
}
}
}
if (mi != NULL)
m_freem(mi);
if (first) {
log_Printf(LogCCP, "DeflateInput: Length error\n");
m_freem(mo_head);
ccp_SendResetReq(&ccp->fsm);
return NULL;
}
olen += (mo->m_len = DEFLATE_CHUNK_LEN - state->cx.avail_out);
*proto = ((u_short)wp[0] << 8) | wp[1];
mo_head->m_offset += 2;
mo_head->m_len -= 2;
olen -= 2;
ccp->compin += ilen;
ccp->uncompin += olen;
log_Printf(LogDEBUG, "DeflateInput: %d => %d bytes, proto 0x%04x\n",
ilen, olen, *proto);
/*
* Simulate an EMPTY_BLOCK so that our dictionary stays in sync.
* The peer will have silently removed this!
*/
state->cx.next_out = garbage;
state->cx.avail_out = sizeof garbage;
state->cx.next_in = EMPTY_BLOCK;
state->cx.avail_in = sizeof EMPTY_BLOCK;
inflate(&state->cx, Z_SYNC_FLUSH);
return mo_head;
}
static void
DeflateDictSetup(void *v, struct ccp *ccp, u_short proto, struct mbuf *mi)
{
struct deflate_state *state = (struct deflate_state *)v;
int res, flush, expect_error;
u_char *rp;
struct mbuf *mi_head;
short len;
log_Printf(LogDEBUG, "DeflateDictSetup: Got seq %d\n", state->seqno);
/*
* Stuff an ``uncompressed data'' block header followed by the
* protocol in front of the input
*/
mi_head = m_get(7, MB_CCPOUT);
mi_head->m_next = mi;
len = m_length(mi);
mi = mi_head;
rp = MBUF_CTOP(mi);
if (proto < 0x100) { /* Compress the protocol */
rp[5] = proto & 0377;
mi->m_len = 6;
len++;
} else { /* Don't compress the protocol */
rp[5] = proto >> 8;
rp[6] = proto & 0377;
mi->m_len = 7;
len += 2;
}
rp[0] = 0x80; /* BITS: 100xxxxx */
rp[1] = len & 0377; /* The length */
rp[2] = len >> 8;
rp[3] = (~len) & 0377; /* One's compliment of the length */
rp[4] = (~len) >> 8;
state->cx.next_in = rp;
state->cx.avail_in = mi->m_len;
state->cx.next_out = garbage;
state->cx.avail_out = sizeof garbage;
flush = Z_NO_FLUSH;
expect_error = 0;
while (1) {
if ((res = inflate(&state->cx, flush)) != Z_OK) {
if (res == Z_STREAM_END)
break; /* Done */
if (expect_error && res == Z_BUF_ERROR)
break;
log_Printf(LogCCP, "DeflateDictSetup: inflate returned %d (%s)\n",
res, state->cx.msg ? state->cx.msg : "");
log_Printf(LogCCP, "DeflateDictSetup: avail_in %d, avail_out %d\n",
state->cx.avail_in, state->cx.avail_out);
ccp_SendResetReq(&ccp->fsm);
m_free(mi_head); /* lose our allocated ``head'' buf */
return;
}
if (flush == Z_SYNC_FLUSH && state->cx.avail_out != 0)
break;
if (state->cx.avail_in == 0 && mi && (mi = mi->m_next) != NULL) {
/* underflow */
state->cx.next_in = MBUF_CTOP(mi);
state->cx.avail_in = mi->m_len;
if (mi->m_next == NULL)
flush = Z_SYNC_FLUSH;
}
if (state->cx.avail_out == 0) {
if (state->cx.avail_in == 0)
/*
* This seems to be a bug in libz ! If inflate() finished
* with 0 avail_in and 0 avail_out *and* this is the end of
* our input *and* inflate() *has* actually written all the
* output it's going to, it *doesn't* return Z_STREAM_END !
* When we subsequently call it with no more input, it gives
* us Z_BUF_ERROR :-( It seems pretty safe to ignore this
* error (the dictionary seems to stay in sync). In the worst
* case, we'll drop the next compressed packet and do a
* CcpReset() then.
*/
expect_error = 1;
/* overflow */
state->cx.next_out = garbage;
state->cx.avail_out = sizeof garbage;
}
}
ccp->compin += len;
ccp->uncompin += len;
state->seqno++;
state->uncomp_rec++;
m_free(mi_head); /* lose our allocated ``head'' buf */
}
static const char *
DeflateDispOpts(struct fsm_opt *o)
{
static char disp[7]; /* Must be used immediately */
sprintf(disp, "win %d", (o->data[0]>>4) + 8);
return disp;
}
static void
DeflateInitOptsOutput(struct bundle *bundle, struct fsm_opt *o,
const struct ccp_config *cfg)
{
o->hdr.len = 4;
o->data[0] = ((cfg->deflate.out.winsize - 8) << 4) + 8;
o->data[1] = '\0';
}
static int
DeflateSetOptsOutput(struct bundle *bundle, struct fsm_opt *o,
const struct ccp_config *cfg)
{
if (o->hdr.len != 4 || (o->data[0] & 15) != 8 || o->data[1] != '\0')
return MODE_REJ;
if ((o->data[0] >> 4) + 8 > 15) {
o->data[0] = ((15 - 8) << 4) + 8;
return MODE_NAK;
}
return MODE_ACK;
}
static int
DeflateSetOptsInput(struct bundle *bundle, struct fsm_opt *o,
const struct ccp_config *cfg)
{
int want;
if (o->hdr.len != 4 || (o->data[0] & 15) != 8 || o->data[1] != '\0')
return MODE_REJ;
want = (o->data[0] >> 4) + 8;
if (cfg->deflate.in.winsize == 0) {
if (want < 8 || want > 15) {
o->data[0] = ((15 - 8) << 4) + 8;
}
} else if (want != cfg->deflate.in.winsize) {
o->data[0] = ((cfg->deflate.in.winsize - 8) << 4) + 8;
return MODE_NAK;
}
return MODE_ACK;
}
static void *
DeflateInitInput(struct bundle *bundle, struct fsm_opt *o)
{
struct deflate_state *state;
state = (struct deflate_state *)malloc(sizeof(struct deflate_state));
if (state != NULL) {
state->winsize = (o->data[0] >> 4) + 8;
state->cx.zalloc = NULL;
state->cx.opaque = NULL;
state->cx.zfree = NULL;
state->cx.next_out = NULL;
if (inflateInit2(&state->cx, -state->winsize) == Z_OK)
DeflateResetInput(state);
else {
free(state);
state = NULL;
}
}
return state;
}
static void *
DeflateInitOutput(struct bundle *bundle, struct fsm_opt *o)
{
struct deflate_state *state;
state = (struct deflate_state *)malloc(sizeof(struct deflate_state));
if (state != NULL) {
state->winsize = (o->data[0] >> 4) + 8;
state->cx.zalloc = NULL;
state->cx.opaque = NULL;
state->cx.zfree = NULL;
state->cx.next_in = NULL;
if (deflateInit2(&state->cx, Z_DEFAULT_COMPRESSION, 8,
-state->winsize, 8, Z_DEFAULT_STRATEGY) == Z_OK)
DeflateResetOutput(state);
else {
free(state);
state = NULL;
}
}
return state;
}
static void
DeflateTermInput(void *v)
{
struct deflate_state *state = (struct deflate_state *)v;
inflateEnd(&state->cx);
free(state);
}
static void
DeflateTermOutput(void *v)
{
struct deflate_state *state = (struct deflate_state *)v;
deflateEnd(&state->cx);
free(state);
}
const struct ccp_algorithm PppdDeflateAlgorithm = {
TY_PPPD_DEFLATE, /* Older versions of pppd expected this ``type'' */
CCP_NEG_DEFLATE24,
DeflateDispOpts,
ccp_DefaultUsable,
ccp_DefaultRequired,
{
DeflateSetOptsInput,
DeflateInitInput,
DeflateTermInput,
DeflateResetInput,
DeflateInput,
DeflateDictSetup
},
{
0,
DeflateInitOptsOutput,
DeflateSetOptsOutput,
DeflateInitOutput,
DeflateTermOutput,
DeflateResetOutput,
DeflateOutput
},
};
const struct ccp_algorithm DeflateAlgorithm = {
TY_DEFLATE, /* rfc 1979 */
CCP_NEG_DEFLATE,
DeflateDispOpts,
ccp_DefaultUsable,
ccp_DefaultRequired,
{
DeflateSetOptsInput,
DeflateInitInput,
DeflateTermInput,
DeflateResetInput,
DeflateInput,
DeflateDictSetup
},
{
0,
DeflateInitOptsOutput,
DeflateSetOptsOutput,
DeflateInitOutput,
DeflateTermOutput,
DeflateResetOutput,
DeflateOutput
},
};