freebsd-dev/usr.sbin/ppp/deflate.c
Brian Somers 6301d506fb Reduce the interface MTU by 2 when MPPE has been successfully negotiated.
This is necessary because MPPE will combine the protocol id with the
payload received on the tun interface, encrypt it, then prepend its
own protocol id, effectively increasing the payload by two bytes.
2001-07-03 22:20:19 +00:00

604 lines
16 KiB
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.
*
* $FreeBSD$
*/
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <termios.h>
#include <zlib.h>
#include "defs.h"
#include "mbuf.h"
#include "log.h"
#include "timer.h"
#include "fsm.h"
#include "lqr.h"
#include "hdlc.h"
#include "lcp.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 lcp_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 lcp_opt *o, const struct ccp_config *cfg)
{
o->len = 4;
o->data[0] = ((cfg->deflate.out.winsize - 8) << 4) + 8;
o->data[1] = '\0';
}
static int
DeflateSetOptsOutput(struct lcp_opt *o, const struct ccp_config *cfg)
{
if (o->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 lcp_opt *o, const struct ccp_config *cfg)
{
int want;
if (o->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 lcp_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 lcp_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
},
};