move package/linux into target/linux, use wbx' new kernel code. support building images with more than one kernel, split kernel module parts off of packages that use their own kernel modules (fuse, shfs, openswan). some cleanup in the image building process in target/. image builder is disabled for now, needs some fixing.

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@1085 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 1649 insertions, 0 deletions

diff --git a/openwrt/target/linux/linux-2.4/patches/106-mppe_mppc.patch b/openwrt/target/linux/linux-2.4/patches/106-mppe_mppc.patch
new file mode 100644
index 000000000..382b4623f
--- /dev/null
+++ b/openwrt/target/linux/linux-2.4/patches/106-mppe_mppc.patch
@@ -0,0 +1,1649 @@
+MPPE/MPPC kernel module for Linux
+
+Microsoft Point-to-Point Encryption / Compression support
+
+  http://www.polbox.com/h/hs001/linux-2.4.29-mppe-mppc-1.3.patch.gz
+
+diff -ruN linux-2.4.29.orig/Documentation/Configure.help linux-2.4.29/Documentation/Configure.help
+--- linux-2.4.29.orig/Documentation/Configure.help	2005-02-02 22:18:18.000000000 +0100
++++ linux-2.4.29/Documentation/Configure.help	2005-02-02 22:26:37.000000000 +0100
+@@ -9969,6 +9969,28 @@
+   module; it is called bsd_comp.o and will show up in the directory
+   modules once you have said "make modules". If unsure, say N.
+ 
++Microsoft PPP compression/encryption (MPPC/MPPE)
++CONFIG_PPP_MPPE_MPPC
++  Support for the Microsoft Point-To-Point Compression (RFC2118) and 
++  Microsoft Point-To-Point Encryption (RFC3078). These protocols are
++  supported by Microsoft Windows and wide range of "hardware" access
++  servers. MPPE is common protocol in Virtual Private Networks. According
++  to RFC3078, MPPE supports 40, 56 and 128-bit key lengths. Depending on
++  PPP daemon configuration on both ends of the link, following scenarios
++  are possible:
++	- only compression (MPPC) is used,
++	- only encryption (MPPE) is used,
++	- compression and encryption (MPPC+MPPE) are used.
++
++  Please note that Hi/Fn (http://www.hifn.com) holds patent on MPPC so
++  you should check if this patent is valid in your country in order to
++  avoid legal problems.
++
++  For more information please visit http://free.polbox.pl/h/hs001
++
++  To compile this driver as a module, choose M here. The module will
++  be called ppp_mppe_mppc.o.
++
+ PPP over Ethernet
+ CONFIG_PPPOE
+   Support for PPP over Ethernet.
+diff -ruN linux-2.4.29.orig/crypto/Config.in linux-2.4.29/crypto/Config.in
+--- linux-2.4.29.orig/crypto/Config.in	2005-02-02 22:18:14.000000000 +0100
++++ linux-2.4.29/crypto/Config.in	2005-02-02 22:26:37.000000000 +0100
+@@ -11,7 +11,9 @@
+      "$CONFIG_INET6_AH" = "y" -o \
+      "$CONFIG_INET6_AH" = "m" -o \
+      "$CONFIG_INET6_ESP" = "y" -o \
+-     "$CONFIG_INET6_ESP" = "m" ]; then
++     "$CONFIG_INET6_ESP" = "m" -o \
++     "$CONFIG_PPP_MPPE_MPPC" = "y" -o \
++     "$CONFIG_PPP_MPPE_MPPC" = "m" ]; then
+   define_bool CONFIG_CRYPTO y
+ else
+   bool 'Cryptographic API' CONFIG_CRYPTO
+@@ -51,11 +53,24 @@
+        "$CONFIG_INET6_AH" = "y" -o \
+        "$CONFIG_INET6_AH" = "m" -o \
+        "$CONFIG_INET6_ESP" = "y" -o \
+-       "$CONFIG_INET6_ESP" = "m" ]; then
+-    define_bool CONFIG_CRYPTO_SHA1 y
+-  else
+-    tristate       '  SHA1 digest algorithm' CONFIG_CRYPTO_SHA1
++       "$CONFIG_INET6_ESP" = "m" -o \
++       "$CONFIG_PPP_MPPE_MPPC" = "y" -o \
++       "$CONFIG_PPP_MPPE_MPPC" = "m" ]; then
++    if [ "$CONFIG_INET_AH" = "y" -o \
++	 "$CONFIG_INET_ESP" = "y" -o \
++	 "$CONFIG_INET6_AH" = "y" -o \
++	 "$CONFIG_INET6_ESP" = "y" -o \
++	 "$CONFIG_PPP_MPPE_MPPC" = "y" ]; then
++      define_tristate CONFIG_CRYPTO_SHA1 y
++    else
++      if [ "$CONFIG_CRYPTO_SHA1" != "y" -a \
++	   "$CONFIG_CRYPTO_SHA1" != "m" ]; then
++	define_tristate CONFIG_CRYPTO_SHA1 m
++      fi
++    fi
+   fi
++  tristate       '  SHA1 digest algorithm' CONFIG_CRYPTO_SHA1
++
+   tristate       '  SHA256 digest algorithm' CONFIG_CRYPTO_SHA256
+   tristate       '  SHA384 and SHA512 digest algorithms' CONFIG_CRYPTO_SHA512
+   tristate       '  Whirlpool digest algorithms' CONFIG_CRYPTO_WP512
+@@ -76,7 +91,20 @@
+   tristate       '  TEA and XTEA cipher algorithms' CONFIG_CRYPTO_TEA
+   tristate       '  Khazad cipher algorithm' CONFIG_CRYPTO_KHAZAD
+   tristate       '  Anubis cipher algorithm' CONFIG_CRYPTO_ANUBIS
++
++  if [ "$CONFIG_PPP_MPPE_MPPC" = "y" -o \
++       "$CONFIG_PPP_MPPE_MPPC" = "m" ]; then
++    if [ "$CONFIG_PPP_MPPE_MPPC" = "y" ]; then
++      define_tristate CONFIG_CRYPTO_ARC4 y
++    else
++      if [ "$CONFIG_CRYPTO_ARC4" != "y" -a \
++	   "$CONFIG_CRYPTO_ARC4" != "m" ]; then
++	define_tristate CONFIG_CRYPTO_ARC4 m
++      fi
++    fi
++  fi
+   tristate       '  ARC4 cipher algorithm' CONFIG_CRYPTO_ARC4
++
+   if [ "$CONFIG_INET_IPCOMP" = "y" -o \
+        "$CONFIG_INET_IPCOMP" = "m" -o \
+        "$CONFIG_INET6_IPCOMP" = "y" -o \
+diff -ruN linux-2.4.29.orig/drivers/net/Config.in linux-2.4.29/drivers/net/Config.in
+--- linux-2.4.29.orig/drivers/net/Config.in	2005-02-02 22:17:31.000000000 +0100
++++ linux-2.4.29/drivers/net/Config.in	2005-02-02 22:26:37.000000000 +0100
+@@ -332,6 +332,7 @@
+    dep_tristate '  PPP support for sync tty ports' CONFIG_PPP_SYNC_TTY $CONFIG_PPP
+    dep_tristate '  PPP Deflate compression' CONFIG_PPP_DEFLATE $CONFIG_PPP
+    dep_tristate '  PPP BSD-Compress compression' CONFIG_PPP_BSDCOMP $CONFIG_PPP
++   dep_tristate '  Microsoft PPP compression/encryption (MPPC/MPPE)' CONFIG_PPP_MPPE_MPPC $CONFIG_PPP
+    if [ "$CONFIG_EXPERIMENTAL" = "y" ]; then
+       dep_tristate '  PPP over Ethernet (EXPERIMENTAL)' CONFIG_PPPOE $CONFIG_PPP
+    fi
+diff -ruN linux-2.4.29.orig/drivers/net/Makefile linux-2.4.29/drivers/net/Makefile
+--- linux-2.4.29.orig/drivers/net/Makefile	2005-02-02 22:17:23.000000000 +0100
++++ linux-2.4.29/drivers/net/Makefile	2005-02-02 22:26:37.000000000 +0100
+@@ -163,6 +163,7 @@
+ obj-$(CONFIG_PPP_SYNC_TTY) += ppp_synctty.o
+ obj-$(CONFIG_PPP_DEFLATE) += ppp_deflate.o
+ obj-$(CONFIG_PPP_BSDCOMP) += bsd_comp.o
++obj-$(CONFIG_PPP_MPPE_MPPC) += ppp_mppe_mppc.o
+ obj-$(CONFIG_PPPOE) += pppox.o pppoe.o
+ 
+ obj-$(CONFIG_SLIP) += slip.o
+diff -ruN linux-2.4.29.orig/drivers/net/ppp_generic.c linux-2.4.29/drivers/net/ppp_generic.c
+--- linux-2.4.29.orig/drivers/net/ppp_generic.c	2005-02-02 22:17:24.000000000 +0100
++++ linux-2.4.29/drivers/net/ppp_generic.c	2005-02-02 22:26:37.000000000 +0100
+@@ -19,7 +19,7 @@
+  * PPP driver, written by Michael Callahan and Al Longyear, and
+  * subsequently hacked by Paul Mackerras.
+  *
+- * ==FILEVERSION 20020217==
++ * ==FILEVERSION 20040509==
+  */
+ 
+ #include <linux/config.h>
+@@ -102,6 +102,7 @@
+ 	spinlock_t	rlock;		/* lock for receive side 58 */
+ 	spinlock_t	wlock;		/* lock for transmit side 5c */
+ 	int		mru;		/* max receive unit 60 */
++	int		mru_alloc;	/* MAX(1500,MRU) for dev_alloc_skb() */
+ 	unsigned int	flags;		/* control bits 64 */
+ 	unsigned int	xstate;		/* transmit state bits 68 */
+ 	unsigned int	rstate;		/* receive state bits 6c */
+@@ -552,7 +553,9 @@
+ 	case PPPIOCSMRU:
+ 		if (get_user(val, (int *) arg))
+ 			break;
+-		ppp->mru = val;
++		ppp->mru_alloc = ppp->mru = val;
++		if (ppp->mru_alloc < PPP_MRU)
++		    ppp->mru_alloc = PPP_MRU;	/* increase for broken peers */
+ 		err = 0;
+ 		break;
+ 
+@@ -1025,14 +1028,37 @@
+ 	case PPP_CCP:
+ 		/* peek at outbound CCP frames */
+ 		ppp_ccp_peek(ppp, skb, 0);
++		/*
++		 * When LZS or MPPE/MPPC has been negotiated we don't send
++		 * CCP_RESETACK after receiving CCP_RESETREQ; in fact pppd
++		 * sends such a packet but we silently discard it here
++		 */
++		if (CCP_CODE(skb->data+2) == CCP_RESETACK
++		    && (ppp->xcomp->compress_proto == CI_MPPE
++			|| ppp->xcomp->compress_proto == CI_LZS)) {
++		    --ppp->stats.tx_packets;
++		    ppp->stats.tx_bytes -= skb->len - 2;
++		    kfree_skb(skb);
++		    return;
++		}
+ 		break;
+ 	}
+ 
+ 	/* try to do packet compression */
+ 	if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state != 0
+ 	    && proto != PPP_LCP && proto != PPP_CCP) {
+-		new_skb = alloc_skb(ppp->dev->mtu + ppp->dev->hard_header_len,
+-				    GFP_ATOMIC);
++		int comp_ovhd = 0;
++		/* 
++		 * because of possible data expansion when MPPC or LZS
++		 * is used, allocate compressor's buffer 12.5% bigger
++		 * than MTU
++		 */
++		if (ppp->xcomp->compress_proto == CI_MPPE)
++		    comp_ovhd = ((ppp->dev->mtu * 9) / 8) + 1 + MPPE_OVHD;
++		else if (ppp->xcomp->compress_proto == CI_LZS)
++		    comp_ovhd = ((ppp->dev->mtu * 9) / 8) + 1 + LZS_OVHD;
++		new_skb = alloc_skb(ppp->dev->mtu + ppp->dev->hard_header_len
++				    + comp_ovhd, GFP_ATOMIC);
+ 		if (new_skb == 0) {
+ 			printk(KERN_ERR "PPP: no memory (comp pkt)\n");
+ 			goto drop;
+@@ -1050,9 +1076,21 @@
+ 			skb = new_skb;
+ 			skb_put(skb, len);
+ 			skb_pull(skb, 2);	/* pull off A/C bytes */
+-		} else {
++		} else if (len == 0) {
+ 			/* didn't compress, or CCP not up yet */
+ 			kfree_skb(new_skb);
++		} else {
++			/*
++			 * (len < 0)
++			 * MPPE requires that we do not send unencrypted
++			 * frames.  The compressor will return -1 if we
++			 * should drop the frame.  We cannot simply test
++			 * the compress_proto because MPPE and MPPC share
++			 * the same number.
++			 */
++			printk(KERN_ERR "ppp: compressor dropped pkt\n");
++			kfree_skb(new_skb);
++			goto drop;
+ 		}
+ 	}
+ 
+@@ -1540,14 +1578,15 @@
+ 	int len;
+ 
+ 	if (proto == PPP_COMP) {
+-		ns = dev_alloc_skb(ppp->mru + PPP_HDRLEN);
++		ns = dev_alloc_skb(ppp->mru_alloc + PPP_HDRLEN);
+ 		if (ns == 0) {
+ 			printk(KERN_ERR "ppp_decompress_frame: no memory\n");
+ 			goto err;
+ 		}
+ 		/* the decompressor still expects the A/C bytes in the hdr */
+ 		len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
+-				skb->len + 2, ns->data, ppp->mru + PPP_HDRLEN);
++				skb->len + 2, ns->data,
++				ppp->mru_alloc + PPP_HDRLEN);
+ 		if (len < 0) {
+ 			/* Pass the compressed frame to pppd as an
+ 			   error indication. */
+@@ -1573,7 +1612,14 @@
+ 	return skb;
+ 
+  err:
+-	ppp->rstate |= SC_DC_ERROR;
++	if (ppp->rcomp->compress_proto != CI_MPPE
++	    && ppp->rcomp->compress_proto != CI_LZS) {
++	    /*
++	     * If decompression protocol isn't MPPE/MPPC or LZS, we set
++	     * SC_DC_ERROR flag and wait for CCP_RESETACK
++	     */
++	    ppp->rstate |= SC_DC_ERROR;
++	}
+ 	ppp_receive_error(ppp);
+ 	return skb;
+ }
+@@ -2253,6 +2299,7 @@
+ 	/* Initialize the new ppp unit */
+ 	ppp->file.index = unit;
+ 	ppp->mru = PPP_MRU;
++	ppp->mru_alloc = PPP_MRU;
+ 	init_ppp_file(&ppp->file, INTERFACE);
+ 	ppp->file.hdrlen = PPP_HDRLEN - 2;	/* don't count proto bytes */
+ 	for (i = 0; i < NUM_NP; ++i)
+diff -ruN linux-2.4.29.orig/drivers/net/ppp_mppe_mppc.c linux-2.4.29/drivers/net/ppp_mppe_mppc.c
+--- linux-2.4.29.orig/drivers/net/ppp_mppe_mppc.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.4.29/drivers/net/ppp_mppe_mppc.c	2005-02-02 23:07:40.000000000 +0100
+@@ -0,0 +1,1312 @@
++/*
++ * ppp_mppe_mppc.c - MPPC/MPPE "compressor/decompressor" module.
++ *
++ * Copyright (c) 1994 Árpád Magosányi <mag@bunuel.tii.matav.hu>
++ * Copyright (c) 1999 Tim Hockin, Cobalt Networks Inc. <thockin@cobaltnet.com>
++ * Copyright (c) 2002-2005 Jan Dubiec <jdx@slackware.pl>
++ * 
++ * 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 code is based on MPPE kernel module written by Árpád Magosányi and
++ * Tim Hockin which can be found on http://planetmirror.com/pub/mppe/.
++ * I have added MPPC and 56 bit session keys support in MPPE.
++ *
++ * WARNING! Although this is open source code, its usage in some countries
++ * (in particular in the USA) may violate Stac Inc. patent for MPPC.
++ *
++ *  ==FILEVERSION 20050202==
++ *
++ */
++
++#include <linux/init.h>
++#include <linux/module.h>
++#include <linux/mm.h>
++#include <linux/slab.h>
++#include <asm/scatterlist.h>
++#include <linux/vmalloc.h>
++#include <linux/crypto.h>
++
++#include <linux/ppp_defs.h>
++#include <linux/ppp-comp.h>
++
++/*
++ * In 2.4.x kernels macro offset_in_page() is not defined in linux/mm.h so
++ * we define it here; PAGE_MASK is defined in asm/page.h which is included
++ * by linux/mm.h.
++ */
++#define offset_in_page(p)	((unsigned long)(p) & ~PAGE_MASK)
++
++/*
++ * State for a mppc/mppe "(de)compressor".
++ */
++struct ppp_mppe_state {
++    struct crypto_tfm *arc4_tfm;
++    struct crypto_tfm *sha1_tfm;
++    u8		*sha1_digest;
++    u8		master_key[MPPE_MAX_KEY_LEN];
++    u8		session_key[MPPE_MAX_KEY_LEN];
++    u8		mppc;		/* do we use compression (MPPC)? */
++    u8		mppe;		/* do we use encryption (MPPE)? */
++    u8		keylen;		/* key length in bytes */
++    u8		bitkeylen;	/* key length in bits */
++    u16		ccount;		/* coherency counter */
++    u16		bits;		/* MPPC/MPPE control bits */
++    u8		stateless;	/* do we use stateless mode? */
++    u8		nextflushed;	/* set A bit in the next outgoing packet;
++				   used only by compressor*/
++    u8		flushexpected;	/* drop packets until A bit is received;
++				   used only by decompressor*/
++    u8		*hist;		/* MPPC history */
++    u16		*hash;		/* Hash table; used only by compressor */
++    u16		histptr;	/* history "cursor" */
++    int		unit;
++    int		debug;
++    int		mru;
++    struct compstat stats;
++};
++
++#define MPPE_HIST_LEN		8192	/* MPPC history size */
++#define MPPE_MAX_CCOUNT		0x0FFF	/* max. coherency counter value */
++
++#define MPPE_BIT_FLUSHED	0x80	/* bit A */
++#define MPPE_BIT_RESET		0x40	/* bit B */
++#define MPPE_BIT_COMP		0x20	/* bit C */
++#define MPPE_BIT_ENCRYPTED	0x10	/* bit D */
++
++#define MPPE_SALT0		0xD1	/* values used in MPPE key derivation */
++#define MPPE_SALT1		0x26	/* according to RFC3079 */
++#define MPPE_SALT2		0x9E
++
++#define MPPE_CCOUNT(x)		((((x)[4] & 0x0f) << 8) + (x)[5])
++#define MPPE_BITS(x)		((x)[4] & 0xf0)
++#define MPPE_CTRLHI(x)		((((x)->ccount & 0xf00)>>8)|((x)->bits))
++#define MPPE_CTRLLO(x)		((x)->ccount & 0xff)
++
++/*
++ * Kernel Crypto API needs its arguments to be in kmalloc'd memory, not in the
++ * module static data area. That means sha_pad needs to be kmalloc'd. It is done
++ * in mppe_module_init(). This has been pointed out on 30th July 2004 by Oleg
++ * Makarenko on pptpclient-devel mailing list.
++ */
++#define SHA1_PAD_SIZE		40
++struct sha_pad {
++    unsigned char sha_pad1[SHA1_PAD_SIZE];
++    unsigned char sha_pad2[SHA1_PAD_SIZE];
++};
++static struct sha_pad *sha_pad;
++
++static inline void
++setup_sg(struct scatterlist *sg, const void  *address, unsigned int length)
++{
++    sg[0].page = virt_to_page(address);
++    sg[0].offset = offset_in_page(address);
++    sg[0].length = length;
++}
++
++static inline void
++arc4_setkey(struct ppp_mppe_state *state, const unsigned char *key,
++	    const unsigned int keylen)
++{
++    crypto_cipher_setkey(state->arc4_tfm, key, keylen);
++}
++
++static inline void
++arc4_encrypt(struct ppp_mppe_state *state, const unsigned char *in,
++	     const unsigned int len, unsigned char *out)
++{
++    struct scatterlist sgin[4], sgout[4];
++
++    setup_sg(sgin, in, len);
++    setup_sg(sgout, out, len);
++    crypto_cipher_encrypt(state->arc4_tfm, sgout, sgin, len);
++}
++
++#define arc4_decrypt arc4_encrypt
++
++/*
++ * Key Derivation, from RFC 3078, RFC 3079.
++ * Equivalent to Get_Key() for MS-CHAP as described in RFC 3079.
++ */
++static void
++get_new_key_from_sha(struct ppp_mppe_state *state, unsigned char *interim_key)
++{
++    struct scatterlist sg[4];
++
++    setup_sg(&sg[0], state->master_key, state->keylen);
++    setup_sg(&sg[1], sha_pad->sha_pad1, sizeof(sha_pad->sha_pad1));
++    setup_sg(&sg[2], state->session_key, state->keylen);
++    setup_sg(&sg[3], sha_pad->sha_pad2, sizeof(sha_pad->sha_pad2));
++
++    crypto_digest_digest (state->sha1_tfm, sg, 4, state->sha1_digest);
++
++    memcpy(interim_key, state->sha1_digest, state->keylen);
++}
++
++static void
++mppe_change_key(struct ppp_mppe_state *state, int initialize)
++{
++    unsigned char interim_key[MPPE_MAX_KEY_LEN];
++
++    get_new_key_from_sha(state, interim_key);
++    if (initialize) {
++	memcpy(state->session_key, interim_key, state->keylen);
++    } else {
++	arc4_setkey(state, interim_key, state->keylen);
++	arc4_encrypt(state, interim_key, state->keylen, state->session_key);
++    }
++    if (state->keylen == 8) {
++	if (state->bitkeylen == 40) {
++	    state->session_key[0] = MPPE_SALT0;
++	    state->session_key[1] = MPPE_SALT1;
++	    state->session_key[2] = MPPE_SALT2;
++	} else {
++	    state->session_key[0] = MPPE_SALT0;
++	}
++    }
++    arc4_setkey(state, state->session_key, state->keylen);
++}
++
++/* increase 12-bit coherency counter */
++static inline void
++mppe_increase_ccount(struct ppp_mppe_state *state)
++{
++    state->ccount = (state->ccount + 1) & MPPE_MAX_CCOUNT;
++    if (state->mppe) {
++	if (state->stateless) {
++	    mppe_change_key(state, 0);
++	    state->nextflushed = 1;
++	} else {
++	    if ((state->ccount & 0xff) == 0xff) {
++		mppe_change_key(state, 0);
++	    }
++	}
++    }
++}
++
++/* allocate space for a MPPE/MPPC (de)compressor.  */
++/*   comp != 0 -> init compressor */
++/*   comp = 0 -> init decompressor */
++static void *
++mppe_alloc(unsigned char *options, int opt_len, int comp)
++{
++    struct ppp_mppe_state *state;
++    unsigned int digestsize;
++    u8* fname;
++
++    fname = comp ? "mppe_comp_alloc" : "mppe_decomp_alloc";
++
++    /*  
++     * Hack warning - additionally to the standard MPPC/MPPE configuration
++     * options, pppd passes to the (de)copressor 8 or 16 byte session key.
++     * Therefore options[1] contains MPPC/MPPE configuration option length
++     * (CILEN_MPPE = 6), but the real options length, depending on the key
++     * length, is 6+8 or 6+16.
++     */
++    if (opt_len < CILEN_MPPE) {
++	printk(KERN_WARNING "%s: wrong options length: %u\n", fname, opt_len);
++	return NULL;
++    }
++
++    if (options[0] != CI_MPPE || options[1] != CILEN_MPPE ||
++	(options[2] & ~MPPE_STATELESS) != 0 ||
++	options[3] != 0 || options[4] != 0 ||
++	(options[5] & ~(MPPE_128BIT|MPPE_56BIT|MPPE_40BIT|MPPE_MPPC)) != 0 ||
++	(options[5] & (MPPE_128BIT|MPPE_56BIT|MPPE_40BIT|MPPE_MPPC)) == 0) {
++	printk(KERN_WARNING "%s: options rejected: o[0]=%02x, o[1]=%02x, "
++	       "o[2]=%02x, o[3]=%02x, o[4]=%02x, o[5]=%02x\n", fname, options[0],
++	       options[1], options[2], options[3], options[4], options[5]);
++	return NULL;
++    }
++
++    state = (struct ppp_mppe_state *)kmalloc(sizeof(*state), GFP_KERNEL);
++    if (state == NULL) {
++	printk(KERN_ERR "%s: cannot allocate space for %scompressor\n", fname,
++	       comp ? "" : "de");
++	return NULL;
++    }
++    memset(state, 0, sizeof(struct ppp_mppe_state));
++
++    state->mppc = options[5] & MPPE_MPPC;	/* Do we use MPPC? */
++    state->mppe = options[5] & (MPPE_128BIT | MPPE_56BIT |
++	MPPE_40BIT);				/* Do we use MPPE? */
++
++    if (state->mppc) {
++	/* allocate MPPC history */
++	state->hist = (u8*)vmalloc(2*MPPE_HIST_LEN*sizeof(u8));
++	if (state->hist == NULL) {
++	    kfree(state);
++	    printk(KERN_ERR "%s: cannot allocate space for MPPC history\n",
++		   fname);
++	    return NULL;
++	}
++
++	/* allocate hashtable for MPPC compressor */
++	if (comp) {
++	    state->hash = (u16*)vmalloc(MPPE_HIST_LEN*sizeof(u16));
++	    if (state->hash == NULL) {
++		vfree(state->hist);
++		kfree(state);
++		printk(KERN_ERR "%s: cannot allocate space for MPPC history\n",
++		       fname);
++		return NULL;
++	    }
++	}
++    }
++
++    if (state->mppe) { /* specific for MPPE */
++	/* Load ARC4 algorithm */
++	state->arc4_tfm = crypto_alloc_tfm("arc4", 0);
++	if (state->arc4_tfm == NULL) {
++	    if (state->mppc) {
++		vfree(state->hash);
++		if (comp)
++		    vfree(state->hist);
++	    }
++	    kfree(state);
++	    printk(KERN_ERR "%s: cannot load ARC4 module\n", fname);
++	    return NULL;
++	}
++
++	/* Load SHA1 algorithm */
++	state->sha1_tfm = crypto_alloc_tfm("sha1", 0);
++	if (state->sha1_tfm == NULL) {
++	    crypto_free_tfm(state->arc4_tfm);
++	    if (state->mppc) {
++		vfree(state->hash);
++		if (comp)
++		    vfree(state->hist);
++	    }
++	    kfree(state);
++	    printk(KERN_ERR "%s: cannot load SHA1 module\n", fname);
++	    return NULL;
++	}
++
++	digestsize = crypto_tfm_alg_digestsize(state->sha1_tfm);
++	if (digestsize < MPPE_MAX_KEY_LEN) {
++	    crypto_free_tfm(state->sha1_tfm);
++	    crypto_free_tfm(state->arc4_tfm);
++	    if (state->mppc) {
++		vfree(state->hash);
++		if (comp)
++		    vfree(state->hist);
++	    }
++	    kfree(state);
++	    printk(KERN_ERR "%s: CryptoAPI SHA1 digest size too small\n", fname);
++	}
++
++	state->sha1_digest = kmalloc(digestsize, GFP_KERNEL);
++	if (!state->sha1_digest) {
++	    crypto_free_tfm(state->sha1_tfm);
++	    crypto_free_tfm(state->arc4_tfm);
++	    if (state->mppc) {
++		vfree(state->hash);
++		if (comp)
++		    vfree(state->hist);
++	    }
++	    kfree(state);
++	    printk(KERN_ERR "%s: cannot allocate space for SHA1 digest\n", fname);
++	}
++
++	memcpy(state->master_key, options+CILEN_MPPE, MPPE_MAX_KEY_LEN);
++	memcpy(state->session_key, state->master_key, MPPE_MAX_KEY_LEN);
++	/* initial key generation is done in mppe_init() */
++    }
++
++    MOD_INC_USE_COUNT;
++
++    return (void *) state;
++}
++
++static void *
++mppe_comp_alloc(unsigned char *options, int opt_len)
++{
++    return mppe_alloc(options, opt_len, 1);
++}
++
++static void *
++mppe_decomp_alloc(unsigned char *options, int opt_len)
++{
++    return mppe_alloc(options, opt_len, 0);
++}
++
++/* cleanup the (de)compressor */
++static void
++mppe_comp_free(void *arg)
++{
++    struct ppp_mppe_state *state = (struct ppp_mppe_state *) arg;
++
++    if (state != NULL) {
++	if (state->mppe) {
++	    if (state->sha1_tfm != NULL)
++		crypto_free_tfm(state->sha1_tfm);
++	    if (state->arc4_tfm != NULL)
++		crypto_free_tfm(state->arc4_tfm);
++	}
++	if (state->hist != NULL)
++	    vfree(state->hist);
++	if (state->hash != NULL)
++	    vfree(state->hash);
++	kfree(state);
++    }
++
++    MOD_DEC_USE_COUNT;
++}
++
++/* init MPPC/MPPE (de)compresor */
++/*   comp != 0 -> init compressor */
++/*   comp = 0 -> init decompressor */
++static int
++mppe_init(void *arg, unsigned char *options, int opt_len, int unit,
++	  int hdrlen, int mru, int debug, int comp)
++{
++    struct ppp_mppe_state *state = (struct ppp_mppe_state *) arg;
++    u8* fname;
++
++    fname = comp ? "mppe_comp_init" : "mppe_decomp_init";
++
++    if (opt_len < CILEN_MPPE) {
++	if (debug)
++	    printk(KERN_WARNING "%s: wrong options length: %u\n",
++		   fname, opt_len);
++	return 0;
++    }
++
++    if (options[0] != CI_MPPE || options[1] != CILEN_MPPE ||
++	(options[2] & ~MPPE_STATELESS) != 0 ||
++	options[3] != 0 || options[4] != 0 ||
++	(options[5] & ~(MPPE_56BIT|MPPE_128BIT|MPPE_40BIT|MPPE_MPPC)) != 0 ||
++	(options[5] & (MPPE_56BIT|MPPE_128BIT|MPPE_40BIT|MPPE_MPPC)) == 0) {
++	if (debug)
++	    printk(KERN_WARNING "%s: options rejected: o[0]=%02x, o[1]=%02x, "
++		   "o[2]=%02x, o[3]=%02x, o[4]=%02x, o[5]=%02x\n", fname,
++		   options[0], options[1], options[2], options[3], options[4],
++		   options[5]);
++	return 0;
++    }
++
++    if ((options[5] & ~MPPE_MPPC) != MPPE_128BIT &&
++	(options[5] & ~MPPE_MPPC) != MPPE_56BIT &&
++	(options[5] & ~MPPE_MPPC) != MPPE_40BIT &&
++	(options[5] & MPPE_MPPC) != MPPE_MPPC) {
++	if (debug)
++	    printk(KERN_WARNING "%s: don't know what to do: o[5]=%02x\n",
++		   fname, options[5]);
++	return 0;
++    }
++
++    state->mppc = options[5] & MPPE_MPPC;	/* Do we use MPPC? */
++    state->mppe = options[5] & (MPPE_128BIT | MPPE_56BIT |
++	MPPE_40BIT);				/* Do we use MPPE? */
++    state->stateless = options[2] & MPPE_STATELESS; /* Do we use stateless mode? */
++
++    switch (state->mppe) {
++    case MPPE_40BIT:     /* 40 bit key */
++	state->keylen = 8;
++	state->bitkeylen = 40;
++	break;
++    case MPPE_56BIT:     /* 56 bit key */
++	state->keylen = 8;
++	state->bitkeylen = 56;
++	break;
++    case MPPE_128BIT:    /* 128 bit key */
++	state->keylen = 16;
++	state->bitkeylen = 128;
++	break;
++    default:
++	state->keylen = 0;
++	state->bitkeylen = 0;
++    }
++
++    state->ccount = MPPE_MAX_CCOUNT;
++    state->bits = 0;
++    state->unit  = unit;
++    state->debug = debug;
++    state->histptr = MPPE_HIST_LEN;
++    if (state->mppc) {	/* reset history if MPPC was negotiated */
++	memset(state->hist, 0, 2*MPPE_HIST_LEN*sizeof(u8));
++    }
++
++    if (state->mppe) { /* generate initial session keys */
++	mppe_change_key(state, 1);
++    }
++
++    if (comp) { /* specific for compressor */
++	state->nextflushed = 1;
++    } else { /* specific for decompressor */
++	state->mru = mru;
++	state->flushexpected = 1;
++    }
++
++    return 1;
++}
++
++static int
++mppe_comp_init(void *arg, unsigned char *options, int opt_len, int unit,
++	       int hdrlen, int debug)
++{
++    return mppe_init(arg, options, opt_len, unit, hdrlen, 0, debug, 1);
++}
++
++
++static int
++mppe_decomp_init(void *arg, unsigned char *options, int opt_len, int unit,
++		 int hdrlen, int mru, int debug)
++{
++    return mppe_init(arg, options, opt_len, unit, hdrlen, mru, debug, 0);
++}
++
++static void
++mppe_comp_reset(void *arg)
++{
++    struct ppp_mppe_state *state = (struct ppp_mppe_state *)arg;
++
++    if (state->debug)
++	printk(KERN_DEBUG "%s%d: resetting MPPC/MPPE compressor\n",
++	       __FUNCTION__, state->unit);
++
++    state->nextflushed = 1;
++    if (state->mppe)
++	arc4_setkey(state, state->session_key, state->keylen);
++}
++
++static void
++mppe_decomp_reset(void *arg)
++{
++    /* When MPPC/MPPE is in use, we shouldn't receive any CCP Reset-Ack.
++       But when we receive such a packet, we just ignore it. */
++    return;
++}
++
++static void
++mppe_stats(void *arg, struct compstat *stats)
++{
++    struct ppp_mppe_state *state = (struct ppp_mppe_state *)arg;
++
++    *stats = state->stats;
++}
++
++/***************************/
++/**** Compression stuff ****/
++/***************************/
++/* inserts 1 to 8 bits into the output buffer */
++static inline void putbits8(u8 *buf, u32 val, const u32 n, u32 *i, u32 *l)
++{
++    buf += *i;
++    if (*l >= n) {
++	*l = (*l) - n;
++	val <<= *l;
++	*buf = *buf | (val & 0xff);
++	if (*l == 0) {
++	    *l = 8;
++	    (*i)++;
++	    *(++buf) = 0;
++	}
++    } else {
++	(*i)++;
++	*l = 8 - n + (*l);
++	val <<= *l;
++	*buf = *buf | ((val >> 8) & 0xff);
++	*(++buf) = val & 0xff;
++    }
++}
++
++/* inserts 9 to 16 bits into the output buffer */
++static inline void putbits16(u8 *buf, u32 val, const u32 n, u32 *i, u32 *l)
++{
++    buf += *i;
++    if (*l >= n - 8) {
++	(*i)++;
++	*l = 8 - n + (*l);
++	val <<= *l;
++	*buf = *buf | ((val >> 8) & 0xff);
++	*(++buf) = val & 0xff;
++	if (*l == 0) {
++	    *l = 8;
++	    (*i)++;
++	    *(++buf) = 0;
++	}
++    } else {
++	(*i)++; (*i)++;
++	*l = 16 - n + (*l);
++	val <<= *l;
++	*buf = *buf | ((val >> 16) & 0xff);
++	*(++buf) = (val >> 8) & 0xff;
++	*(++buf) = val & 0xff;
++    }
++}
++
++/* inserts 17 to 24 bits into the output buffer */
++static inline void putbits24(u8 *buf, u32 val, const u32 n, u32 *i, u32 *l)
++{
++    buf += *i;
++    if (*l >= n - 16) {
++	(*i)++; (*i)++;
++	*l = 16 - n + (*l);
++	val <<= *l;
++	*buf = *buf | ((val >> 16) & 0xff);
++	*(++buf) = (val >> 8) & 0xff;
++	*(++buf) = val & 0xff;
++	if (*l == 0) {
++	    *l = 8;
++	    (*i)++;
++	    *(++buf) = 0;
++	}
++    } else {
++	(*i)++; (*i)++; (*i)++;
++	*l = 24 - n + (*l);
++	val <<= *l;
++	*buf = *buf | ((val >> 24) & 0xff);
++	*(++buf) = (val >> 16) & 0xff;
++	*(++buf) = (val >> 8) & 0xff;
++	*(++buf) = val & 0xff;
++    }
++}
++
++static int
++mppc_compress(struct ppp_mppe_state *state, unsigned char *ibuf,
++	      unsigned char *obuf, int isize, int osize)
++{
++    u32 olen, off, len, idx, i, l;
++    u8 *hist, *sbuf, *p, *q, *r, *s;
++
++    /*  
++	At this point, to avoid possible buffer overflow caused by packet
++	expansion during/after compression,  we should make sure that
++	osize >= (((isize*9)/8)+1)+2, but we don't do that because in
++	ppp_generic.c we simply allocate bigger obuf.
++
++	Maximum MPPC packet expansion is 12.5%. This is the worst case when
++	all octets in the input buffer are >= 0x80 and we cannot find any
++	repeated tokens. Additionally we have to reserve 2 bytes for MPPE/MPPC
++	status bits and coherency counter.
++    */
++
++    hist = state->hist + MPPE_HIST_LEN;
++    /* check if there is enough room at the end of the history */
++    if (state->histptr + isize >= 2*MPPE_HIST_LEN) {
++	state->bits |= MPPE_BIT_RESET;
++	state->histptr = MPPE_HIST_LEN;
++	memcpy(state->hist, hist, MPPE_HIST_LEN);
++    }
++    /* add packet to the history; isize must be <= MPPE_HIST_LEN */
++    sbuf = state->hist + state->histptr;
++    memcpy(sbuf, ibuf, isize);
++    state->histptr += isize;
++
++    /* compress data */
++    r = sbuf + isize;
++    *obuf = olen = i = 0;
++    l = 8;
++    while (i < isize - 2) {
++	s = q = sbuf + i;
++	idx = ((40543*((((s[0]<<4)^s[1])<<4)^s[2]))>>4) & 0x1fff;
++	p = hist + state->hash[idx];
++	state->hash[idx] = (u16) (s - hist);
++	off = s - p;
++	if (off > MPPE_HIST_LEN - 1 || off < 1 || *p++ != *s++ || *p++ != *s++ ||
++	    *p++ != *s++) {
++	    /* no match found; encode literal byte */
++	    if (ibuf[i] < 0x80) {		/* literal byte < 0x80 */
++		putbits8(obuf, (u32) ibuf[i], 8, &olen, &l);
++	    } else {				/* literal byte >= 0x80 */
++		putbits16(obuf, (u32) (0x100|(ibuf[i]&0x7f)), 9, &olen, &l);
++	    }
++	    ++i;
++	    continue;
++	}
++	if (r - q >= 64) {
++	    *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || *p++ != *s++ ||
++	    *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || *p++ != *s++ ||
++	    *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || *p++ != *s++ ||
++	    *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || *p++ != *s++ ||
++	    *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || *p++ != *s++ ||
++	    *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || *p++ != *s++ ||
++	    *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || *p++ != *s++ ||
++	    *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || *p++ != *s++ ||
++	    *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || *p++ != *s++ ||
++	    *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || *p++ != *s++ ||
++	    *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || *p++ != *s++ ||
++	    *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || *p++ != *s++ ||
++	    *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || *p++ != *s++ ||
++	    *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || *p++ != *s++ ||
++	    *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || *p++ != *s++ ||
++	    *p++ != *s++;
++	    if (s - q == 64) {
++		p--; s--;
++		while((*p++ == *s++) && (s < r) && (p < q));
++	    }
++	} else {
++	    while((*p++ == *s++) && (s < r) && (p < q));
++	}
++	len = s - q - 1;
++	i += len;
++
++	/* at least 3 character match found; code data */
++	/* encode offset */
++	if (off < 64) {			/* 10-bit offset; 0 <= offset < 64 */
++	    putbits16(obuf, 0x3c0|off, 10, &olen, &l);
++	} else if (off < 320) {		/* 12-bit offset; 64 <= offset < 320 */
++	    putbits16(obuf, 0xe00|(off-64), 12, &olen, &l);
++	} else if (off < 8192) {	/* 16-bit offset; 320 <= offset < 8192 */
++	    putbits16(obuf, 0xc000|(off-320), 16, &olen, &l);
++	} else {
++	    /* This shouldn't happen; we return 0 what means "packet expands",
++	    and we send packet uncompressed. */
++	    if (state->debug)
++		printk(KERN_DEBUG "%s%d: wrong offset value: %d\n",
++		       __FUNCTION__, state->unit, off);
++	    return 0;
++	}
++	/* encode length of match */
++	if (len < 4) {			/* length = 3 */
++	    putbits8(obuf, 0, 1, &olen, &l);
++	} else if (len < 8) {		/* 4 <= length < 8 */
++	    putbits8(obuf, 0x08|(len&0x03), 4, &olen, &l);
++	} else if (len < 16) {		/* 8 <= length < 16 */
++	    putbits8(obuf, 0x30|(len&0x07), 6, &olen, &l);
++	} else if (len < 32) {		/* 16 <= length < 32 */
++	    putbits8(obuf, 0xe0|(len&0x0f), 8, &olen, &l);
++	} else if (len < 64) {		/* 32 <= length < 64 */
++	    putbits16(obuf, 0x3c0|(len&0x1f), 10, &olen, &l);
++	} else if (len < 128) {		/* 64 <= length < 128 */
++	    putbits16(obuf, 0xf80|(len&0x3f), 12, &olen, &l);
++	} else if (len < 256) {		/* 128 <= length < 256 */
++	    putbits16(obuf, 0x3f00|(len&0x7f), 14, &olen, &l);
++	} else if (len < 512) {		/* 256 <= length < 512 */
++	    putbits16(obuf, 0xfe00|(len&0xff), 16, &olen, &l);
++	} else if (len < 1024) {	/* 512 <= length < 1024 */
++	    putbits24(obuf, 0x3fc00|(len&0x1ff), 18, &olen, &l);
++	} else if (len < 2048) {	/* 1024 <= length < 2048 */
++	    putbits24(obuf, 0xff800|(len&0x3ff), 20, &olen, &l);
++	} else if (len < 4096) {	/* 2048 <= length < 4096 */
++	    putbits24(obuf, 0x3ff000|(len&0x7ff), 22, &olen, &l);
++	} else if (len < 8192) {	/* 4096 <= length < 8192 */
++	    putbits24(obuf, 0xffe000|(len&0xfff), 24, &olen, &l);
++	} else {
++	    /* This shouldn't happen; we return 0 what means "packet expands",
++	    and send packet uncompressed. */
++	    if (state->debug)
++		printk(KERN_DEBUG "%s%d: wrong length of match value: %d\n",
++		       __FUNCTION__, state->unit, len);
++	    return 0;
++	}
++    }
++
++    /* Add remaining octets to the output */
++    while(isize - i > 0) {
++	if (ibuf[i] < 0x80) {	/* literal byte < 0x80 */
++	    putbits8(obuf, (u32) ibuf[i++], 8, &olen, &l);
++	} else {		/* literal byte >= 0x80 */
++	    putbits16(obuf, (u32) (0x100|(ibuf[i++]&0x7f)), 9, &olen, &l);
++	}
++    }
++    /* Reset unused bits of the last output octet */
++    if ((l != 0) && (l != 8)) {
++	putbits8(obuf, 0, l, &olen, &l);
++    }
++
++    return (int) olen;
++}
++
++int
++mppe_compress(void *arg, unsigned char *ibuf, unsigned char *obuf,
++	      int isize, int osize)
++{
++    struct ppp_mppe_state *state = (struct ppp_mppe_state *) arg;
++    int proto, olen, complen, off;
++    unsigned char *wptr;
++
++    /* Check that the protocol is in the range we handle. */
++    proto = PPP_PROTOCOL(ibuf);
++    if (proto < 0x0021 || proto > 0x00fa)
++	return 0;
++
++    wptr = obuf;
++    /* Copy over the PPP header */
++    wptr[0] = PPP_ADDRESS(ibuf);
++    wptr[1] = PPP_CONTROL(ibuf);
++    wptr[2] = PPP_COMP >> 8;
++    wptr[3] = PPP_COMP;
++    wptr += PPP_HDRLEN + (MPPE_OVHD / 2); /* Leave two octets for MPPE/MPPC bits */
++
++    /* 
++     * In ver. 0.99 protocol field was compressed. Deflate and BSD compress
++     * do PFC before actual compression, RCF2118 and RFC3078 are not precise
++     * on this topic so I decided to do PFC. Unfortunately this change caused
++     * incompatibility with older/other MPPE/MPPC modules. I have received
++     * a lot of complaints from unexperienced users so I have decided to revert
++     * to previous state, i.e. the protocol field is sent uncompressed now.
++     * Although this may be changed in the future.
++     *
++     * Receiving side (mppe_decompress()) still accepts packets with compressed
++     * and uncompressed protocol field so you shouldn't get "Unsupported protocol
++     * 0x2145 received" messages anymore.
++     */
++    //off = (proto > 0xff) ? 2 : 3; /* PFC - skip first protocol byte if 0 */
++    off = 2;
++
++    ibuf += off;
++
++    mppe_increase_ccount(state);
++
++    if (state->nextflushed) {
++	state->bits |= MPPE_BIT_FLUSHED;
++	state->nextflushed = 0;
++	if (state->mppe && !state->stateless) {
++	    /*
++	     * If this is the flag packet, the key has been already changed in
++	     * mppe_increase_ccount() so we dont't do it once again.
++	     */
++	    if ((state->ccount & 0xff) != 0xff) {
++		arc4_setkey(state, state->session_key, state->keylen);
++	    }
++	}
++	if (state->mppc) { /* reset history */
++	    state->bits |= MPPE_BIT_RESET;
++	    state->histptr = MPPE_HIST_LEN;
++	    memset(state->hist + MPPE_HIST_LEN, 0, MPPE_HIST_LEN*sizeof(u8));
++	}
++    }
++
++    if (state->mppc && !state->mppe) { /* Do only compression */
++	complen = mppc_compress(state, ibuf, wptr, isize - off,
++				osize - PPP_HDRLEN - (MPPE_OVHD / 2));
++	/*
++	 * TODO: Implement an heuristics to handle packet expansion in a smart
++	 * way. Now, when a packet expands, we send it as uncompressed and
++	 * when next packet is sent we have to reset compressor's history.
++	 * Maybe it would be better to send such packet as compressed in order
++	 * to keep history's continuity.
++	 */
++	if ((complen > isize) || (complen > osize - PPP_HDRLEN) ||
++	    (complen == 0)) {
++	    /* packet expands */
++	    state->nextflushed = 1;
++	    memcpy(wptr, ibuf, isize - off);
++	    olen = isize - (off - 2) + MPPE_OVHD;
++	    (state->stats).inc_bytes += olen;
++	    (state->stats).inc_packets++;
++	} else {
++	    state->bits |= MPPE_BIT_COMP;
++	    olen = complen + PPP_HDRLEN + (MPPE_OVHD / 2);
++	    (state->stats).comp_bytes += olen;
++	    (state->stats).comp_packets++;
++	}
++    } else { /* Do encryption with or without compression */
++	state->bits |= MPPE_BIT_ENCRYPTED;
++	if (!state->mppc && state->mppe) { /* Do only encryption */
++	    /* read from ibuf, write to wptr, adjust for PPP_HDRLEN */
++	    arc4_encrypt(state, ibuf, isize - off, wptr);
++	    olen = isize - (off - 2) + MPPE_OVHD;
++	    (state->stats).inc_bytes += olen;
++	    (state->stats).inc_packets++;
++	} else { /* Do compression and then encryption - RFC3078 */
++	    complen = mppc_compress(state, ibuf, wptr, isize - off,
++				    osize - PPP_HDRLEN - (MPPE_OVHD / 2));
++	    /*
++	     * TODO: Implement an heuristics to handle packet expansion in a smart
++	     * way. Now, when a packet expands, we send it as uncompressed and
++	     * when next packet is sent we have to reset compressor's history.
++	     * Maybe it would be good to send such packet as compressed in order
++	     * to keep history's continuity.
++	     */
++	    if ((complen > isize) || (complen > osize - PPP_HDRLEN) ||
++		(complen == 0)) {
++		/* packet expands */
++		state->nextflushed = 1;
++		arc4_encrypt(state, ibuf, isize - off, wptr);
++		olen = isize - (off - 2) + MPPE_OVHD;
++		(state->stats).inc_bytes += olen;
++		(state->stats).inc_packets++;
++	    } else {
++		state->bits |= MPPE_BIT_COMP;
++		/* Hack warning !!! RC4 implementation which we use does
++		   encryption "in place" - it means that input and output
++		   buffers can be *the same* memory area. Therefore we don't
++		   need to use a temporary buffer. But be careful - other
++		   implementations don't have to be so nice.
++		   I used to use ibuf as temporary buffer here, but it led
++		   packet sniffers into error. Thanks to Wilfried Weissmann
++		   for pointing that. */
++		arc4_encrypt(state, wptr, complen, wptr);
++		olen = complen + PPP_HDRLEN + (MPPE_OVHD / 2);
++		(state->stats).comp_bytes += olen;
++		(state->stats).comp_packets++;
++	    }
++	}
++    }
++
++    /* write status bits and coherency counter into the output buffer */
++    wptr = obuf + PPP_HDRLEN;
++    wptr[0] = MPPE_CTRLHI(state);
++    wptr[1] = MPPE_CTRLLO(state);
++
++    state->bits = 0;
++
++    (state->stats).unc_bytes += isize;
++    (state->stats).unc_packets++;
++
++    return olen;
++}
++
++/***************************/
++/*** Decompression stuff ***/
++/***************************/
++static inline u32 getbits(const u8 *buf, const u32 n, u32 *i, u32 *l)
++{
++    static const u32 m[] = {0x00, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f, 0xff};
++    u32 res, ol;
++
++    ol = *l;
++    if (*l >= n) {
++	*l = (*l) - n;
++	res = (buf[*i] & m[ol]) >> (*l);
++	if (*l == 0) {
++	    *l = 8;
++	    (*i)++;
++	}
++    } else {
++	*l = 8 - n + (*l);
++	res = (buf[(*i)++] & m[ol]) << 8;
++	res = (res | buf[*i]) >> (*l);
++    }
++
++    return res;
++}
++
++static inline u32 getbyte(const u8 *buf, const u32 i, const u32 l)
++{
++    if (l == 8) {
++	return buf[i];
++    } else {
++	return (((buf[i] << 8) | buf[i+1]) >> l) & 0xff;
++    }
++}
++
++static inline void lamecopy(u8 *dst, u8 *src, u32 len)
++{
++    while (len--)
++	*dst++ = *src++;
++}
++
++static int
++mppc_decompress(struct ppp_mppe_state *state, unsigned char *ibuf,
++		unsigned char *obuf, int isize, int osize)
++{
++    u32 olen, off, len, bits, val, sig, i, l;
++    u8 *history, *s;
++
++    history = state->hist + state->histptr;
++    olen = len = i = 0;
++    l = 8;
++    bits = isize * 8;
++    while (bits >= 8) {
++	val = getbyte(ibuf, i++, l);
++	if (val < 0x80) {		/* literal byte < 0x80 */
++	    if (state->histptr < 2*MPPE_HIST_LEN) {
++		/* copy uncompressed byte to the history */
++		(state->hist)[(state->histptr)++] = (u8) val;
++	    } else {
++		/* buffer overflow; drop packet */
++		if (state->debug)
++		    printk(KERN_ERR "%s%d: trying to write outside history "
++			   "buffer\n", __FUNCTION__, state->unit);
++		return DECOMP_ERROR;
++	    }
++	    olen++;
++	    bits -= 8;
++	    continue;
++	}
++
++	sig = val & 0xc0;
++	if (sig == 0x80) {		/* literal byte >= 0x80 */
++	    if (state->histptr < 2*MPPE_HIST_LEN) {
++		/* copy uncompressed byte to the history */
++		(state->hist)[(state->histptr)++] = 
++		    (u8) (0x80|((val&0x3f)<<1)|getbits(ibuf, 1 , &i ,&l));
++	    } else {
++		/* buffer overflow; drop packet */
++		if (state->debug)
++		    printk(KERN_ERR "%s%d: trying to write outside history "
++			   "buffer\n", __FUNCTION__, state->unit);
++		return DECOMP_ERROR;
++	    }
++	    olen++;
++	    bits -= 9;
++	    continue;
++	}
++
++	/* Not a literal byte so it must be an (offset,length) pair */
++	/* decode offset */
++	sig = val & 0xf0;
++	if (sig == 0xf0) {		/* 10-bit offset; 0 <= offset < 64 */
++	    off = (((val&0x0f)<<2)|getbits(ibuf, 2 , &i ,&l));
++	    bits -= 10;
++	} else {
++	    if (sig == 0xe0) {		/* 12-bit offset; 64 <= offset < 320 */
++		off = ((((val&0x0f)<<4)|getbits(ibuf, 4 , &i ,&l))+64);
++		bits -= 12;
++	    } else {
++		if ((sig&0xe0) == 0xc0) {/* 16-bit offset; 320 <= offset < 8192 */
++		    off = ((((val&0x1f)<<8)|getbyte(ibuf, i++, l))+320);
++		    bits -= 16;
++		    if (off > MPPE_HIST_LEN - 1) {
++			if (state->debug)
++			    printk(KERN_DEBUG "%s%d: too big offset value: %d\n",
++				   __FUNCTION__, state->unit, off);
++			return DECOMP_ERROR;
++		    }
++		} else {		/* this shouldn't happen */
++		    if (state->debug)
++			printk(KERN_DEBUG "%s%d: cannot decode offset value\n",
++			       __FUNCTION__, state->unit);
++		    return DECOMP_ERROR;
++		}
++	    }
++	}
++	/* decode length of match */
++	val = getbyte(ibuf, i, l);
++	if ((val & 0x80) == 0x00) {			/* len = 3 */
++	    len = 3;
++	    bits--;
++	    getbits(ibuf, 1 , &i ,&l);
++	} else if ((val & 0xc0) == 0x80) {		/* 4 <= len < 8 */
++	    len = 0x04 | ((val>>4) & 0x03);
++	    bits -= 4;
++	    getbits(ibuf, 4 , &i ,&l);
++	} else if ((val & 0xe0) == 0xc0) {		/* 8 <= len < 16 */
++	    len = 0x08 | ((val>>2) & 0x07);
++	    bits -= 6;
++	    getbits(ibuf, 6 , &i ,&l);
++	} else if ((val & 0xf0) == 0xe0) {		/* 16 <= len < 32 */
++	    len = 0x10 | (val & 0x0f);
++	    bits -= 8;
++	    i++;
++	} else {
++	    bits -= 8;
++	    val = (val << 8) | getbyte(ibuf, ++i, l);
++	    if ((val & 0xf800) == 0xf000) {		/* 32 <= len < 64 */
++		len = 0x0020 | ((val >> 6) & 0x001f);
++		bits -= 2;
++		getbits(ibuf, 2 , &i ,&l);
++	    } else if ((val & 0xfc00) == 0xf800) {	/* 64 <= len < 128 */
++		len = 0x0040 | ((val >> 4) & 0x003f);
++		bits -= 4;
++		getbits(ibuf, 4 , &i ,&l);
++	    } else if ((val & 0xfe00) == 0xfc00) {	/* 128 <= len < 256 */
++		len = 0x0080 | ((val >> 2) & 0x007f);
++		bits -= 6;
++		getbits(ibuf, 6 , &i ,&l);
++	    } else if ((val & 0xff00) == 0xfe00) {	/* 256 <= len < 512 */
++		len = 0x0100 | (val & 0x00ff);
++		bits -= 8;
++		i++;
++	    } else {
++		bits -= 8;
++		val = (val << 8) | getbyte(ibuf, ++i, l);
++		if ((val & 0xff8000) == 0xff0000) {	/* 512 <= len < 1024 */
++		    len = 0x000200 | ((val >> 6) & 0x0001ff);
++		    bits -= 2;
++		    getbits(ibuf, 2 , &i ,&l);
++		} else if ((val & 0xffc000) == 0xff8000) {/* 1024 <= len < 2048 */
++		    len = 0x000400 | ((val >> 4) & 0x0003ff);
++		    bits -= 4;
++		    getbits(ibuf, 4 , &i ,&l);
++		} else if ((val & 0xffe000) == 0xffc000) {/* 2048 <= len < 4096 */
++		    len = 0x000800 | ((val >> 2) & 0x0007ff);
++		    bits -= 6;
++		    getbits(ibuf, 6 , &i ,&l);
++		} else if ((val & 0xfff000) == 0xffe000) {/* 4096 <= len < 8192 */
++		    len = 0x001000 | (val & 0x000fff);
++		    bits -= 8;
++		    i++;
++		} else {				/* this shouldn't happen */
++		    if (state->debug)
++			printk(KERN_DEBUG "%s%d: wrong length code: 0x%X\n",
++			       __FUNCTION__, state->unit, val);
++		    return DECOMP_ERROR;
++		}
++	    }
++	}
++	s = state->hist + state->histptr;
++	state->histptr += len;
++	olen += len;
++	if (state->histptr < 2*MPPE_HIST_LEN) {
++	    /* copy uncompressed bytes to the history */
++
++	    /* In some cases len may be greater than off. It means that memory
++	     * areas pointed by s and s-off overlap. I had used memmove() here
++	     * because I thought that it acts as libc's version. Unfortunately,
++	     * I was wrong. :-) I got strange errors sometimes. Wilfried suggested
++	     * using of byte by byte copying here and strange errors disappeared.
++	     */
++	    lamecopy(s, s - off, len);
++	} else {
++	    /* buffer overflow; drop packet */
++	    if (state->debug)
++		printk(KERN_ERR "%s%d: trying to write outside history "
++		       "buffer\n", __FUNCTION__, state->unit);
++	    return DECOMP_ERROR;
++	}
++    }
++
++    /* Do PFC decompression */
++    len = olen;
++    if ((history[0] & 0x01) != 0) {
++	obuf[0] = 0;
++	obuf++;
++	len++;
++    }
++
++    if (len <= osize) {
++	/* copy uncompressed packet to the output buffer */
++	memcpy(obuf, history, olen);
++    } else {
++	/* buffer overflow; drop packet */
++	if (state->debug)
++	    printk(KERN_ERR "%s%d: too big uncompressed packet: %d\n",
++		   __FUNCTION__, state->unit, len + (PPP_HDRLEN / 2));
++	return DECOMP_ERROR;
++    }
++
++    return (int) len;
++}
++
++int
++mppe_decompress(void *arg, unsigned char *ibuf, int isize,
++		unsigned char *obuf, int osize)
++{
++    struct ppp_mppe_state *state = (struct ppp_mppe_state *)arg;
++    int seq, bits, uncomplen;
++
++    if (isize <= PPP_HDRLEN + MPPE_OVHD) {
++	if (state->debug) {
++	    printk(KERN_DEBUG "%s%d: short packet (len=%d)\n",  __FUNCTION__,
++		   state->unit, isize);
++	}
++	return DECOMP_ERROR;
++    }
++
++    /* Get coherency counter and control bits from input buffer */
++    seq = MPPE_CCOUNT(ibuf);
++    bits = MPPE_BITS(ibuf);
++
++    if (state->stateless) {
++	/* RFC 3078, sec 8.1. */
++	mppe_increase_ccount(state);
++	if ((seq != state->ccount) && state->debug)
++	    printk(KERN_DEBUG "%s%d: bad sequence number: %d, expected: %d\n",
++		   __FUNCTION__, state->unit, seq, state->ccount);
++	while (seq != state->ccount)
++	    mppe_increase_ccount(state);
++    } else {
++	/* RFC 3078, sec 8.2. */
++	if (state->flushexpected) { /* discard state */
++	    if ((bits & MPPE_BIT_FLUSHED)) { /* we received expected FLUSH bit */
++		while (seq != state->ccount)
++		    mppe_increase_ccount(state);
++		state->flushexpected = 0;
++	    } else /* drop packet*/
++		return DECOMP_ERROR;
++	} else { /* normal state */
++	    mppe_increase_ccount(state);
++	    if (seq != state->ccount) {
++		/* Packet loss detected, enter the discard state. */
++		if (state->debug)
++		    printk(KERN_DEBUG "%s%d: bad sequence number: %d, expected: %d\n",
++			   __FUNCTION__, state->unit, seq, state->ccount);
++		state->flushexpected = 1;
++		return DECOMP_ERROR;
++	    }
++	}
++	if (state->mppe && (bits & MPPE_BIT_FLUSHED)) {
++	    arc4_setkey(state, state->session_key, state->keylen);
++	}
++    }
++
++    if (state->mppc && (bits & (MPPE_BIT_FLUSHED | MPPE_BIT_RESET))) {
++	state->histptr = MPPE_HIST_LEN;
++	if ((bits & MPPE_BIT_FLUSHED)) {
++	    memset(state->hist + MPPE_HIST_LEN, 0, MPPE_HIST_LEN*sizeof(u8));
++	} else
++	    if ((bits & MPPE_BIT_RESET)) {
++		memcpy(state->hist, state->hist + MPPE_HIST_LEN, MPPE_HIST_LEN);
++	    }
++    }
++
++    /* 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 += PPP_HDRLEN / 2;
++
++    if (state->mppe) { /* process encrypted packet */
++	if ((bits & MPPE_BIT_ENCRYPTED)) {
++	    /* OK, packet encrypted, so decrypt it */
++	    if (state->mppc && (bits & MPPE_BIT_COMP)) {
++		/* Hack warning !!! RC4 implementation which we use does
++		   decryption "in place" - it means that input and output
++		   buffers can be *the same* memory area. Therefore we don't
++		   need to use a temporary buffer. But be careful - other
++		   implementations don't have to be so nice. */
++		arc4_decrypt(state, ibuf + PPP_HDRLEN +	(MPPE_OVHD / 2), isize -
++			     PPP_HDRLEN - (MPPE_OVHD / 2), ibuf + PPP_HDRLEN +
++			     (MPPE_OVHD / 2));
++		uncomplen = mppc_decompress(state, ibuf + PPP_HDRLEN +
++					    (MPPE_OVHD / 2), obuf, isize -
++					    PPP_HDRLEN - (MPPE_OVHD / 2),
++					    osize - (PPP_HDRLEN / 2));
++		if (uncomplen == DECOMP_ERROR) {
++		    state->flushexpected = 1;
++		    return DECOMP_ERROR;
++		}
++		uncomplen += PPP_HDRLEN / 2;
++		(state->stats).comp_bytes += isize;
++		(state->stats).comp_packets++;
++	    } else {
++		uncomplen = isize - MPPE_OVHD;
++		/* Decrypt the first byte in order to check if it is
++		   compressed or uncompressed protocol field */
++		arc4_decrypt(state, ibuf + PPP_HDRLEN +	(MPPE_OVHD / 2), 1, obuf);
++		/* Do PFC decompression */
++		if ((obuf[0] & 0x01) != 0) {
++		    obuf[1] = obuf[0];
++		    obuf[0] = 0;
++		    obuf++;
++		    uncomplen++;
++		}
++		/* And finally, decrypt the rest of the frame. */
++		arc4_decrypt(state, ibuf + PPP_HDRLEN +	(MPPE_OVHD / 2) + 1,
++			     isize - PPP_HDRLEN - (MPPE_OVHD / 2) - 1, obuf + 1);
++		(state->stats).inc_bytes += isize;
++		(state->stats).inc_packets++;
++	    }
++	} else { /* this shouldn't happen */
++	    if (state->debug)
++		printk(KERN_ERR "%s%d: encryption negotiated but not an "
++		       "encrypted packet received\n", __FUNCTION__, state->unit);
++	    mppe_change_key(state, 0);
++	    state->flushexpected = 1;
++	    return DECOMP_ERROR;
++	}
++    } else {
++	if (state->mppc) { /* no MPPE, only MPPC */
++	    if ((bits & MPPE_BIT_COMP)) {
++		uncomplen = mppc_decompress(state, ibuf + PPP_HDRLEN +
++					    (MPPE_OVHD / 2), obuf, isize -
++					    PPP_HDRLEN - (MPPE_OVHD / 2),
++					    osize - (PPP_HDRLEN / 2));
++		if (uncomplen == DECOMP_ERROR) {
++		    state->flushexpected = 1;
++		    return DECOMP_ERROR;
++		}
++		uncomplen += PPP_HDRLEN / 2;
++		(state->stats).comp_bytes += isize;
++		(state->stats).comp_packets++;
++	    } else {
++		memcpy(obuf, ibuf + PPP_HDRLEN + (MPPE_OVHD / 2), isize -
++		       PPP_HDRLEN - (MPPE_OVHD / 2));
++		uncomplen = isize - MPPE_OVHD;
++		(state->stats).inc_bytes += isize;
++		(state->stats).inc_packets++;
++	    }
++	} else { /* this shouldn't happen */
++	    if (state->debug)
++		printk(KERN_ERR "%s%d: error - not an  MPPC or MPPE frame "
++		       "received\n", __FUNCTION__, state->unit);
++	    state->flushexpected = 1;
++	    return DECOMP_ERROR;
++	}
++    }
++
++    (state->stats).unc_bytes += uncomplen;
++    (state->stats).unc_packets++;
++
++    return uncomplen;
++}
++
++
++/************************************************************
++ * 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);
++
++/*
++ * Functions exported to ppp_generic.c.
++ *
++ * In case of MPPC/MPPE there is no need to process incompressible data
++ * because such a data is sent in MPPC/MPPE frame. Therefore the (*incomp)
++ * callback function isn't needed.
++ */
++struct compressor ppp_mppe = {
++    CI_MPPE,		/* compress_proto */
++    mppe_comp_alloc,	/* comp_alloc */
++    mppe_comp_free,	/* comp_free */
++    mppe_comp_init,	/* comp_init */
++    mppe_comp_reset,	/* comp_reset */
++    mppe_compress,	/* compress */
++    mppe_stats,		/* comp_stat */
++    mppe_decomp_alloc,	/* decomp_alloc */
++    mppe_comp_free,	/* decomp_free */
++    mppe_decomp_init,	/* decomp_init */
++    mppe_decomp_reset,	/* decomp_reset */
++    mppe_decompress,	/* decompress */
++    NULL,		/* incomp */
++    mppe_stats,		/* decomp_stat */
++};
++
++/************************************************************
++ * Module support routines
++ ************************************************************/
++
++int __init mppe_module_init(void)
++{
++    int answer;
++
++    /* When the module is compiled into kernel, it is initialized before
++     * CryptoAPI. Therefore the code below reports that there is no crypto
++     * stuff in the kernel. Marlon de Boer who has pointed out the problem,
++     * has sent also a message to CryptoAPI developers, so maybe in the future
++     * the code will be uncommented.
++     *
++    if (!(crypto_alg_available("arc4", 0) && crypto_alg_available("sha1", 0))) {
++	printk(KERN_ERR "Kernel doesn't provide ARC4 and/or SHA1 algorithms "
++	       "required by MPPE/MPPC. Check CryptoAPI configuration.\n");
++	return -ENODEV;
++    }
++    */
++
++    /* Allocate space for SHAPad1, SHAPad2 and ... */
++    sha_pad = kmalloc(sizeof(struct sha_pad), GFP_KERNEL);
++    if (sha_pad == NULL)
++	return -ENOMEM;
++    /* ... initialize them */
++    memset(sha_pad->sha_pad1, 0x00, sizeof(sha_pad->sha_pad1));
++    memset(sha_pad->sha_pad2, 0xf2, sizeof(sha_pad->sha_pad2));
++
++    answer = ppp_register_compressor(&ppp_mppe);
++    if (answer == 0) {
++	printk(KERN_INFO "MPPE/MPPC encryption/compression module registered\n");
++    }
++    return answer;
++}
++
++void __exit mppe_module_cleanup(void)
++{
++    kfree(sha_pad);
++    ppp_unregister_compressor(&ppp_mppe);
++    printk(KERN_INFO "MPPE/MPPC encryption/compression module unregistered\n");
++}
++
++module_init(mppe_module_init);
++module_exit(mppe_module_cleanup);
++
++MODULE_AUTHOR("Jan Dubiec <jdx@slackware.pl>");
++MODULE_DESCRIPTION("MPPE/MPPC encryption/compression module for Linux");
++MODULE_LICENSE("Dual BSD/GPL");
+diff -ruN linux-2.4.29.orig/include/linux/ppp-comp.h linux-2.4.29/include/linux/ppp-comp.h
+--- linux-2.4.29.orig/include/linux/ppp-comp.h	2005-02-02 22:18:25.000000000 +0100
++++ linux-2.4.29/include/linux/ppp-comp.h	2005-02-02 22:41:01.000000000 +0100
+@@ -28,7 +28,7 @@
+  */
+ 
+ /*
+- *  ==FILEVERSION 980319==
++ *  ==FILEVERSION 20040509==
+  *
+  *  NOTE TO MAINTAINERS:
+  *     If you modify this file at all, please set the above date.
+@@ -78,7 +78,7 @@
+ 
+ 	/* Compress a packet */
+ 	int     (*compress) (void *state, unsigned char *rptr,
+-			      unsigned char *obuf, int isize, int osize);
++			     unsigned char *obuf, int isize, int osize);
+ 
+ 	/* Return compression statistics */
+ 	void	(*comp_stat) (void *state, struct compstat *stats);
+@@ -99,7 +99,7 @@
+ 
+ 	/* Decompress a packet. */
+ 	int	(*decompress) (void *state, unsigned char *ibuf, int isize,
+-				unsigned char *obuf, int osize);
++			       unsigned char *obuf, int osize);
+ 
+ 	/* Update state for an incompressible packet received */
+ 	void	(*incomp) (void *state, unsigned char *ibuf, int icnt);
+@@ -187,6 +187,42 @@
+ #define DEFLATE_CHK_SEQUENCE	0
+ 
+ /*
++ * Definitions for MPPE/MPPC.
++ */
++
++#define CI_MPPE			18	/* config option for MPPE */
++#define CILEN_MPPE		6	/* length of config option */
++
++#define MPPE_OVHD		4	/* MPPE overhead */
++#define MPPE_MAX_KEY_LEN	16	/* largest key length (128-bit) */
++
++#define MPPE_STATELESS          0x01	/* configuration bit H */
++#define MPPE_40BIT              0x20	/* configuration bit L */
++#define MPPE_56BIT              0x80	/* configuration bit M */
++#define MPPE_128BIT             0x40	/* configuration bit S */
++#define MPPE_MPPC               0x01	/* configuration bit C */
++
++/*
++ * Definitions for Stac LZS.
++ */
++
++#define CI_LZS			17	/* config option for Stac LZS */
++#define CILEN_LZS		5	/* length of config option */
++
++#define LZS_OVHD		4	/* max. LZS overhead */
++#define LZS_HIST_LEN		2048	/* LZS history size */
++#define LZS_MAX_CCOUNT		0x0FFF	/* max. coherency counter value */
++
++#define LZS_MODE_NONE		0
++#define LZS_MODE_LCB		1
++#define LZS_MODE_CRC		2
++#define LZS_MODE_SEQ		3
++#define LZS_MODE_EXT		4
++
++#define LZS_EXT_BIT_FLUSHED	0x80	/* bit A */
++#define LZS_EXT_BIT_COMP	0x20	/* bit C */
++
++/*
+  * Definitions for other, as yet unsupported, compression methods.
+  */
+