ppp: Move the PPP drivers

Move the PPP drivers into drivers/net/ppp/ and make the
necessary Kconfig and Makefile changes.

CC: Paul Mackerras <paulus@samba.org>
CC: Frank Cusack <fcusack@fcusack.com>
CC: Michal Ostrowski <mostrows@speakeasy.net>
CC: Michal Ostrowski <mostrows@earthlink.net>
CC: Dmitry Kozlov <xeb@mail.ru>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 0 insertions, 740 deletions

diff --git a/drivers/net/ppp_mppe.c b/drivers/net/ppp_mppe.c
deleted file mode 100644
index 9a1849a83e2a..000000000000
--- a/drivers/net/ppp_mppe.c
+++ /dev/null
@@ -1,740 +0,0 @@
-/*
- * ppp_mppe.c - interface MPPE to the PPP code.
- * This version is for use with Linux kernel 2.6.14+
- *
- * By Frank Cusack <fcusack@fcusack.com>.
- * Copyright (c) 2002,2003,2004 Google, Inc.
- * All rights reserved.
- *
- * License:
- * 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.
- *
- * ALTERNATIVELY, provided that this notice is retained in full, this product
- * may be distributed under the terms of the GNU General Public License (GPL),
- * in which case the provisions of the GPL apply INSTEAD OF those given above.
- *
- *   This program is free software; you can redistribute it and/or modify
- *   it under the terms of the GNU General Public License as published by
- *   the Free Software Foundation; either version 2 of the License, or
- *   (at your option) any later version.
- *
- *   This program is distributed in the hope that it will be useful,
- *   but WITHOUT ANY WARRANTY; without even the implied warranty of
- *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *   GNU General Public License for more details.
- *
- *   You should have received a copy of the GNU General Public License
- *   along with this program; if not, write to the Free Software
- *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
- *
- *
- * Changelog:
- *      08/12/05 - Matt Domsch <Matt_Domsch@dell.com>
- *                 Only need extra skb padding on transmit, not receive.
- *      06/18/04 - Matt Domsch <Matt_Domsch@dell.com>, Oleg Makarenko <mole@quadra.ru>
- *                 Use Linux kernel 2.6 arc4 and sha1 routines rather than
- *                 providing our own.
- *      2/15/04 - TS: added #include <version.h> and testing for Kernel
- *                    version before using
- *                    MOD_DEC_USAGE_COUNT/MOD_INC_USAGE_COUNT which are
- *                    deprecated in 2.6
- */
-
-#include <linux/err.h>
-#include <linux/module.h>
-#include <linux/kernel.h>
-#include <linux/init.h>
-#include <linux/types.h>
-#include <linux/slab.h>
-#include <linux/string.h>
-#include <linux/crypto.h>
-#include <linux/mm.h>
-#include <linux/ppp_defs.h>
-#include <linux/ppp-comp.h>
-#include <linux/scatterlist.h>
-#include <asm/unaligned.h>
-
-#include "ppp_mppe.h"
-
-MODULE_AUTHOR("Frank Cusack <fcusack@fcusack.com>");
-MODULE_DESCRIPTION("Point-to-Point Protocol Microsoft Point-to-Point Encryption support");
-MODULE_LICENSE("Dual BSD/GPL");
-MODULE_ALIAS("ppp-compress-" __stringify(CI_MPPE));
-MODULE_VERSION("1.0.2");
-
-static unsigned int
-setup_sg(struct scatterlist *sg, const void *address, unsigned int length)
-{
-	sg_set_buf(sg, address, length);
-	return length;
-}
-
-#define SHA1_PAD_SIZE 40
-
-/*
- * 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.
- */
-
-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 sha_pad_init(struct sha_pad *shapad)
-{
-	memset(shapad->sha_pad1, 0x00, sizeof(shapad->sha_pad1));
-	memset(shapad->sha_pad2, 0xF2, sizeof(shapad->sha_pad2));
-}
-
-/*
- * State for an MPPE (de)compressor.
- */
-struct ppp_mppe_state {
-	struct crypto_blkcipher *arc4;
-	struct crypto_hash *sha1;
-	unsigned char *sha1_digest;
-	unsigned char master_key[MPPE_MAX_KEY_LEN];
-	unsigned char session_key[MPPE_MAX_KEY_LEN];
-	unsigned keylen;	/* key length in bytes             */
-	/* NB: 128-bit == 16, 40-bit == 8! */
-	/* If we want to support 56-bit,   */
-	/* the unit has to change to bits  */
-	unsigned char bits;	/* MPPE control bits */
-	unsigned ccount;	/* 12-bit coherency count (seqno)  */
-	unsigned stateful;	/* stateful mode flag */
-	int discard;		/* stateful mode packet loss flag */
-	int sanity_errors;	/* take down LCP if too many */
-	int unit;
-	int debug;
-	struct compstat stats;
-};
-
-/* struct ppp_mppe_state.bits definitions */
-#define MPPE_BIT_A	0x80	/* Encryption table were (re)inititalized */
-#define MPPE_BIT_B	0x40	/* MPPC only (not implemented) */
-#define MPPE_BIT_C	0x20	/* MPPC only (not implemented) */
-#define MPPE_BIT_D	0x10	/* This is an encrypted frame */
-
-#define MPPE_BIT_FLUSHED	MPPE_BIT_A
-#define MPPE_BIT_ENCRYPTED	MPPE_BIT_D
-
-#define MPPE_BITS(p) ((p)[4] & 0xf0)
-#define MPPE_CCOUNT(p) ((((p)[4] & 0x0f) << 8) + (p)[5])
-#define MPPE_CCOUNT_SPACE 0x1000	/* The size of the ccount space */
-
-#define MPPE_OVHD	2	/* MPPE overhead/packet */
-#define SANITY_MAX	1600	/* Max bogon factor we will tolerate */
-
-/*
- * 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)
-{
-	struct hash_desc desc;
-	struct scatterlist sg[4];
-	unsigned int nbytes;
-
-	sg_init_table(sg, 4);
-
-	nbytes = setup_sg(&sg[0], state->master_key, state->keylen);
-	nbytes += setup_sg(&sg[1], sha_pad->sha_pad1,
-			   sizeof(sha_pad->sha_pad1));
-	nbytes += setup_sg(&sg[2], state->session_key, state->keylen);
-	nbytes += setup_sg(&sg[3], sha_pad->sha_pad2,
-			   sizeof(sha_pad->sha_pad2));
-
-	desc.tfm = state->sha1;
-	desc.flags = 0;
-
-	crypto_hash_digest(&desc, sg, nbytes, state->sha1_digest);
-}
-
-/*
- * Perform the MPPE rekey algorithm, from RFC 3078, sec. 7.3.
- * Well, not what's written there, but rather what they meant.
- */
-static void mppe_rekey(struct ppp_mppe_state * state, int initial_key)
-{
-	struct scatterlist sg_in[1], sg_out[1];
-	struct blkcipher_desc desc = { .tfm = state->arc4 };
-
-	get_new_key_from_sha(state);
-	if (!initial_key) {
-		crypto_blkcipher_setkey(state->arc4, state->sha1_digest,
-					state->keylen);
-		sg_init_table(sg_in, 1);
-		sg_init_table(sg_out, 1);
-		setup_sg(sg_in, state->sha1_digest, state->keylen);
-		setup_sg(sg_out, state->session_key, state->keylen);
-		if (crypto_blkcipher_encrypt(&desc, sg_out, sg_in,
-					     state->keylen) != 0) {
-    		    printk(KERN_WARNING "mppe_rekey: cipher_encrypt failed\n");
-		}
-	} else {
-		memcpy(state->session_key, state->sha1_digest, state->keylen);
-	}
-	if (state->keylen == 8) {
-		/* See RFC 3078 */
-		state->session_key[0] = 0xd1;
-		state->session_key[1] = 0x26;
-		state->session_key[2] = 0x9e;
-	}
-	crypto_blkcipher_setkey(state->arc4, state->session_key, state->keylen);
-}
-
-/*
- * Allocate space for a (de)compressor.
- */
-static void *mppe_alloc(unsigned char *options, int optlen)
-{
-	struct ppp_mppe_state *state;
-	unsigned int digestsize;
-
-	if (optlen != CILEN_MPPE + sizeof(state->master_key) ||
-	    options[0] != CI_MPPE || options[1] != CILEN_MPPE)
-		goto out;
-
-	state = kzalloc(sizeof(*state), GFP_KERNEL);
-	if (state == NULL)
-		goto out;
-
-
-	state->arc4 = crypto_alloc_blkcipher("ecb(arc4)", 0, CRYPTO_ALG_ASYNC);
-	if (IS_ERR(state->arc4)) {
-		state->arc4 = NULL;
-		goto out_free;
-	}
-
-	state->sha1 = crypto_alloc_hash("sha1", 0, CRYPTO_ALG_ASYNC);
-	if (IS_ERR(state->sha1)) {
-		state->sha1 = NULL;
-		goto out_free;
-	}
-
-	digestsize = crypto_hash_digestsize(state->sha1);
-	if (digestsize < MPPE_MAX_KEY_LEN)
-		goto out_free;
-
-	state->sha1_digest = kmalloc(digestsize, GFP_KERNEL);
-	if (!state->sha1_digest)
-		goto out_free;
-
-	/* Save keys. */
-	memcpy(state->master_key, &options[CILEN_MPPE],
-	       sizeof(state->master_key));
-	memcpy(state->session_key, state->master_key,
-	       sizeof(state->master_key));
-
-	/*
-	 * We defer initial key generation until mppe_init(), as mppe_alloc()
-	 * is called frequently during negotiation.
-	 */
-
-	return (void *)state;
-
-	out_free:
-	    if (state->sha1_digest)
-		kfree(state->sha1_digest);
-	    if (state->sha1)
-		crypto_free_hash(state->sha1);
-	    if (state->arc4)
-		crypto_free_blkcipher(state->arc4);
-	    kfree(state);
-	out:
-	return NULL;
-}
-
-/*
- * Deallocate space for a (de)compressor.
- */
-static void mppe_free(void *arg)
-{
-	struct ppp_mppe_state *state = (struct ppp_mppe_state *) arg;
-	if (state) {
-	    if (state->sha1_digest)
-		kfree(state->sha1_digest);
-	    if (state->sha1)
-		crypto_free_hash(state->sha1);
-	    if (state->arc4)
-		crypto_free_blkcipher(state->arc4);
-	    kfree(state);
-	}
-}
-
-/*
- * Initialize (de)compressor state.
- */
-static int
-mppe_init(void *arg, unsigned char *options, int optlen, int unit, int debug,
-	  const char *debugstr)
-{
-	struct ppp_mppe_state *state = (struct ppp_mppe_state *) arg;
-	unsigned char mppe_opts;
-
-	if (optlen != CILEN_MPPE ||
-	    options[0] != CI_MPPE || options[1] != CILEN_MPPE)
-		return 0;
-
-	MPPE_CI_TO_OPTS(&options[2], mppe_opts);
-	if (mppe_opts & MPPE_OPT_128)
-		state->keylen = 16;
-	else if (mppe_opts & MPPE_OPT_40)
-		state->keylen = 8;
-	else {
-		printk(KERN_WARNING "%s[%d]: unknown key length\n", debugstr,
-		       unit);
-		return 0;
-	}
-	if (mppe_opts & MPPE_OPT_STATEFUL)
-		state->stateful = 1;
-
-	/* Generate the initial session key. */
-	mppe_rekey(state, 1);
-
-	if (debug) {
-		int i;
-		char mkey[sizeof(state->master_key) * 2 + 1];
-		char skey[sizeof(state->session_key) * 2 + 1];
-
-		printk(KERN_DEBUG "%s[%d]: initialized with %d-bit %s mode\n",
-		       debugstr, unit, (state->keylen == 16) ? 128 : 40,
-		       (state->stateful) ? "stateful" : "stateless");
-
-		for (i = 0; i < sizeof(state->master_key); i++)
-			sprintf(mkey + i * 2, "%02x", state->master_key[i]);
-		for (i = 0; i < sizeof(state->session_key); i++)
-			sprintf(skey + i * 2, "%02x", state->session_key[i]);
-		printk(KERN_DEBUG
-		       "%s[%d]: keys: master: %s initial session: %s\n",
-		       debugstr, unit, mkey, skey);
-	}
-
-	/*
-	 * Initialize the coherency count.  The initial value is not specified
-	 * in RFC 3078, but we can make a reasonable assumption that it will
-	 * start at 0.  Setting it to the max here makes the comp/decomp code
-	 * do the right thing (determined through experiment).
-	 */
-	state->ccount = MPPE_CCOUNT_SPACE - 1;
-
-	/*
-	 * Note that even though we have initialized the key table, we don't
-	 * set the FLUSHED bit.  This is contrary to RFC 3078, sec. 3.1.
-	 */
-	state->bits = MPPE_BIT_ENCRYPTED;
-
-	state->unit = unit;
-	state->debug = debug;
-
-	return 1;
-}
-
-static int
-mppe_comp_init(void *arg, unsigned char *options, int optlen, int unit,
-	       int hdrlen, int debug)
-{
-	/* ARGSUSED */
-	return mppe_init(arg, options, optlen, unit, debug, "mppe_comp_init");
-}
-
-/*
- * We received a CCP Reset-Request (actually, we are sending a Reset-Ack),
- * tell the compressor to rekey.  Note that we MUST NOT rekey for
- * every CCP Reset-Request; we only rekey on the next xmit packet.
- * We might get multiple CCP Reset-Requests if our CCP Reset-Ack is lost.
- * So, rekeying for every CCP Reset-Request is broken as the peer will not
- * know how many times we've rekeyed.  (If we rekey and THEN get another
- * CCP Reset-Request, we must rekey again.)
- */
-static void mppe_comp_reset(void *arg)
-{
-	struct ppp_mppe_state *state = (struct ppp_mppe_state *) arg;
-
-	state->bits |= MPPE_BIT_FLUSHED;
-}
-
-/*
- * Compress (encrypt) a packet.
- * It's strange to call this a compressor, since the output is always
- * MPPE_OVHD + 2 bytes larger than the input.
- */
-static 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;
-	struct blkcipher_desc desc = { .tfm = state->arc4 };
-	int proto;
-	struct scatterlist sg_in[1], sg_out[1];
-
-	/*
-	 * Check that the protocol is in the range we handle.
-	 */
-	proto = PPP_PROTOCOL(ibuf);
-	if (proto < 0x0021 || proto > 0x00fa)
-		return 0;
-
-	/* Make sure we have enough room to generate an encrypted packet. */
-	if (osize < isize + MPPE_OVHD + 2) {
-		/* Drop the packet if we should encrypt it, but can't. */
-		printk(KERN_DEBUG "mppe_compress[%d]: osize too small! "
-		       "(have: %d need: %d)\n", state->unit,
-		       osize, osize + MPPE_OVHD + 2);
-		return -1;
-	}
-
-	osize = isize + MPPE_OVHD + 2;
-
-	/*
-	 * Copy over the PPP header and set control bits.
-	 */
-	obuf[0] = PPP_ADDRESS(ibuf);
-	obuf[1] = PPP_CONTROL(ibuf);
-	put_unaligned_be16(PPP_COMP, obuf + 2);
-	obuf += PPP_HDRLEN;
-
-	state->ccount = (state->ccount + 1) % MPPE_CCOUNT_SPACE;
-	if (state->debug >= 7)
-		printk(KERN_DEBUG "mppe_compress[%d]: ccount %d\n", state->unit,
-		       state->ccount);
-	put_unaligned_be16(state->ccount, obuf);
-
-	if (!state->stateful ||	/* stateless mode     */
-	    ((state->ccount & 0xff) == 0xff) ||	/* "flag" packet      */
-	    (state->bits & MPPE_BIT_FLUSHED)) {	/* CCP Reset-Request  */
-		/* We must rekey */
-		if (state->debug && state->stateful)
-			printk(KERN_DEBUG "mppe_compress[%d]: rekeying\n",
-			       state->unit);
-		mppe_rekey(state, 0);
-		state->bits |= MPPE_BIT_FLUSHED;
-	}
-	obuf[0] |= state->bits;
-	state->bits &= ~MPPE_BIT_FLUSHED;	/* reset for next xmit */
-
-	obuf += MPPE_OVHD;
-	ibuf += 2;		/* skip to proto field */
-	isize -= 2;
-
-	/* Encrypt packet */
-	sg_init_table(sg_in, 1);
-	sg_init_table(sg_out, 1);
-	setup_sg(sg_in, ibuf, isize);
-	setup_sg(sg_out, obuf, osize);
-	if (crypto_blkcipher_encrypt(&desc, sg_out, sg_in, isize) != 0) {
-		printk(KERN_DEBUG "crypto_cypher_encrypt failed\n");
-		return -1;
-	}
-
-	state->stats.unc_bytes += isize;
-	state->stats.unc_packets++;
-	state->stats.comp_bytes += osize;
-	state->stats.comp_packets++;
-
-	return osize;
-}
-
-/*
- * Since every frame grows by MPPE_OVHD + 2 bytes, this is always going
- * to look bad ... and the longer the link is up the worse it will get.
- */
-static void mppe_comp_stats(void *arg, struct compstat *stats)
-{
-	struct ppp_mppe_state *state = (struct ppp_mppe_state *) arg;
-
-	*stats = state->stats;
-}
-
-static int
-mppe_decomp_init(void *arg, unsigned char *options, int optlen, int unit,
-		 int hdrlen, int mru, int debug)
-{
-	/* ARGSUSED */
-	return mppe_init(arg, options, optlen, unit, debug, "mppe_decomp_init");
-}
-
-/*
- * We received a CCP Reset-Ack.  Just ignore it.
- */
-static void mppe_decomp_reset(void *arg)
-{
-	/* ARGSUSED */
-	return;
-}
-
-/*
- * Decompress (decrypt) an MPPE packet.
- */
-static 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;
-	struct blkcipher_desc desc = { .tfm = state->arc4 };
-	unsigned ccount;
-	int flushed = MPPE_BITS(ibuf) & MPPE_BIT_FLUSHED;
-	int sanity = 0;
-	struct scatterlist sg_in[1], sg_out[1];
-
-	if (isize <= PPP_HDRLEN + MPPE_OVHD) {
-		if (state->debug)
-			printk(KERN_DEBUG
-			       "mppe_decompress[%d]: short pkt (%d)\n",
-			       state->unit, isize);
-		return DECOMP_ERROR;
-	}
-
-	/*
-	 * Make sure we have enough room to decrypt the packet.
-	 * Note that for our test we only subtract 1 byte whereas in
-	 * mppe_compress() we added 2 bytes (+MPPE_OVHD);
-	 * this is to account for possible PFC.
-	 */
-	if (osize < isize - MPPE_OVHD - 1) {
-		printk(KERN_DEBUG "mppe_decompress[%d]: osize too small! "
-		       "(have: %d need: %d)\n", state->unit,
-		       osize, isize - MPPE_OVHD - 1);
-		return DECOMP_ERROR;
-	}
-	osize = isize - MPPE_OVHD - 2;	/* assume no PFC */
-
-	ccount = MPPE_CCOUNT(ibuf);
-	if (state->debug >= 7)
-		printk(KERN_DEBUG "mppe_decompress[%d]: ccount %d\n",
-		       state->unit, ccount);
-
-	/* sanity checks -- terminate with extreme prejudice */
-	if (!(MPPE_BITS(ibuf) & MPPE_BIT_ENCRYPTED)) {
-		printk(KERN_DEBUG
-		       "mppe_decompress[%d]: ENCRYPTED bit not set!\n",
-		       state->unit);
-		state->sanity_errors += 100;
-		sanity = 1;
-	}
-	if (!state->stateful && !flushed) {
-		printk(KERN_DEBUG "mppe_decompress[%d]: FLUSHED bit not set in "
-		       "stateless mode!\n", state->unit);
-		state->sanity_errors += 100;
-		sanity = 1;
-	}
-	if (state->stateful && ((ccount & 0xff) == 0xff) && !flushed) {
-		printk(KERN_DEBUG "mppe_decompress[%d]: FLUSHED bit not set on "
-		       "flag packet!\n", state->unit);
-		state->sanity_errors += 100;
-		sanity = 1;
-	}
-
-	if (sanity) {
-		if (state->sanity_errors < SANITY_MAX)
-			return DECOMP_ERROR;
-		else
-			/*
-			 * Take LCP down if the peer is sending too many bogons.
-			 * We don't want to do this for a single or just a few
-			 * instances since it could just be due to packet corruption.
-			 */
-			return DECOMP_FATALERROR;
-	}
-
-	/*
-	 * Check the coherency count.
-	 */
-
-	if (!state->stateful) {
-		/* RFC 3078, sec 8.1.  Rekey for every packet. */
-		while (state->ccount != ccount) {
-			mppe_rekey(state, 0);
-			state->ccount = (state->ccount + 1) % MPPE_CCOUNT_SPACE;
-		}
-	} else {
-		/* RFC 3078, sec 8.2. */
-		if (!state->discard) {
-			/* normal state */
-			state->ccount = (state->ccount + 1) % MPPE_CCOUNT_SPACE;
-			if (ccount != state->ccount) {
-				/*
-				 * (ccount > state->ccount)
-				 * Packet loss detected, enter the discard state.
-				 * Signal the peer to rekey (by sending a CCP Reset-Request).
-				 */
-				state->discard = 1;
-				return DECOMP_ERROR;
-			}
-		} else {
-			/* discard state */
-			if (!flushed) {
-				/* ccp.c will be silent (no additional CCP Reset-Requests). */
-				return DECOMP_ERROR;
-			} else {
-				/* Rekey for every missed "flag" packet. */
-				while ((ccount & ~0xff) !=
-				       (state->ccount & ~0xff)) {
-					mppe_rekey(state, 0);
-					state->ccount =
-					    (state->ccount +
-					     256) % MPPE_CCOUNT_SPACE;
-				}
-
-				/* reset */
-				state->discard = 0;
-				state->ccount = ccount;
-				/*
-				 * Another problem with RFC 3078 here.  It implies that the
-				 * peer need not send a Reset-Ack packet.  But RFC 1962
-				 * requires it.  Hopefully, M$ does send a Reset-Ack; even
-				 * though it isn't required for MPPE synchronization, it is
-				 * required to reset CCP state.
-				 */
-			}
-		}
-		if (flushed)
-			mppe_rekey(state, 0);
-	}
-
-	/*
-	 * Fill in the first part of the PPP header.  The protocol field
-	 * comes from the decrypted data.
-	 */
-	obuf[0] = PPP_ADDRESS(ibuf);	/* +1 */
-	obuf[1] = PPP_CONTROL(ibuf);	/* +1 */
-	obuf += 2;
-	ibuf += PPP_HDRLEN + MPPE_OVHD;
-	isize -= PPP_HDRLEN + MPPE_OVHD;	/* -6 */
-	/* net osize: isize-4 */
-
-	/*
-	 * Decrypt the first byte in order to check if it is
-	 * a compressed or uncompressed protocol field.
-	 */
-	sg_init_table(sg_in, 1);
-	sg_init_table(sg_out, 1);
-	setup_sg(sg_in, ibuf, 1);
-	setup_sg(sg_out, obuf, 1);
-	if (crypto_blkcipher_decrypt(&desc, sg_out, sg_in, 1) != 0) {
-		printk(KERN_DEBUG "crypto_cypher_decrypt failed\n");
-		return DECOMP_ERROR;
-	}
-
-	/*
-	 * Do PFC decompression.
-	 * This would be nicer if we were given the actual sk_buff
-	 * instead of a char *.
-	 */
-	if ((obuf[0] & 0x01) != 0) {
-		obuf[1] = obuf[0];
-		obuf[0] = 0;
-		obuf++;
-		osize++;
-	}
-
-	/* And finally, decrypt the rest of the packet. */
-	setup_sg(sg_in, ibuf + 1, isize - 1);
-	setup_sg(sg_out, obuf + 1, osize - 1);
-	if (crypto_blkcipher_decrypt(&desc, sg_out, sg_in, isize - 1)) {
-		printk(KERN_DEBUG "crypto_cypher_decrypt failed\n");
-		return DECOMP_ERROR;
-	}
-
-	state->stats.unc_bytes += osize;
-	state->stats.unc_packets++;
-	state->stats.comp_bytes += isize;
-	state->stats.comp_packets++;
-
-	/* good packet credit */
-	state->sanity_errors >>= 1;
-
-	return osize;
-}
-
-/*
- * Incompressible data has arrived (this should never happen!).
- * We should probably drop the link if the protocol is in the range
- * of what should be encrypted.  At the least, we should drop this
- * packet.  (How to do this?)
- */
-static void mppe_incomp(void *arg, unsigned char *ibuf, int icnt)
-{
-	struct ppp_mppe_state *state = (struct ppp_mppe_state *) arg;
-
-	if (state->debug &&
-	    (PPP_PROTOCOL(ibuf) >= 0x0021 && PPP_PROTOCOL(ibuf) <= 0x00fa))
-		printk(KERN_DEBUG
-		       "mppe_incomp[%d]: incompressible (unencrypted) data! "
-		       "(proto %04x)\n", state->unit, PPP_PROTOCOL(ibuf));
-
-	state->stats.inc_bytes += icnt;
-	state->stats.inc_packets++;
-	state->stats.unc_bytes += icnt;
-	state->stats.unc_packets++;
-}
-
-/*************************************************************
- * Module interface table
- *************************************************************/
-
-/*
- * Procedures exported to if_ppp.c.
- */
-static struct compressor ppp_mppe = {
-	.compress_proto = CI_MPPE,
-	.comp_alloc     = mppe_alloc,
-	.comp_free      = mppe_free,
-	.comp_init      = mppe_comp_init,
-	.comp_reset     = mppe_comp_reset,
-	.compress       = mppe_compress,
-	.comp_stat      = mppe_comp_stats,
-	.decomp_alloc   = mppe_alloc,
-	.decomp_free    = mppe_free,
-	.decomp_init    = mppe_decomp_init,
-	.decomp_reset   = mppe_decomp_reset,
-	.decompress     = mppe_decompress,
-	.incomp         = mppe_incomp,
-	.decomp_stat    = mppe_comp_stats,
-	.owner          = THIS_MODULE,
-	.comp_extra     = MPPE_PAD,
-};
-
-/*
- * ppp_mppe_init()
- *
- * Prior to allowing load, try to load the arc4 and sha1 crypto
- * libraries.  The actual use will be allocated later, but
- * this way the module will fail to insmod if they aren't available.
- */
-
-static int __init ppp_mppe_init(void)
-{
-	int answer;
-	if (!(crypto_has_blkcipher("ecb(arc4)", 0, CRYPTO_ALG_ASYNC) &&
-	      crypto_has_hash("sha1", 0, CRYPTO_ALG_ASYNC)))
-		return -ENODEV;
-
-	sha_pad = kmalloc(sizeof(struct sha_pad), GFP_KERNEL);
-	if (!sha_pad)
-		return -ENOMEM;
-	sha_pad_init(sha_pad);
-
-	answer = ppp_register_compressor(&ppp_mppe);
-
-	if (answer == 0)
-		printk(KERN_INFO "PPP MPPE Compression module registered\n");
-	else
-		kfree(sha_pad);
-
-	return answer;
-}
-
-static void __exit ppp_mppe_cleanup(void)
-{
-	ppp_unregister_compressor(&ppp_mppe);
-	kfree(sha_pad);
-}
-
-module_init(ppp_mppe_init);
-module_exit(ppp_mppe_cleanup);