--- linux-2.6.19.2/drivers/net/Kconfig.orig 2009-07-22 15:44:09.000000000 +0200 +++ linux-2.6.19.2/drivers/net/Kconfig 2010-01-24 20:14:13.000000000 +0100 @@ -2758,18 +2758,31 @@ module; it is called bsd_comp and will show up in the directory modules once you have said "make modules". If unsure, say N. -config PPP_MPPE - tristate "PPP MPPE compression (encryption) (EXPERIMENTAL)" - depends on PPP && EXPERIMENTAL - select CRYPTO - select CRYPTO_SHA1 - select CRYPTO_ARC4 - ---help--- - Support for the MPPE Encryption protocol, as employed by the - Microsoft Point-to-Point Tunneling Protocol. +config PPP_MPPE_MPPC + tristate "Microsoft PPP compression/encryption (MPPC/MPPE)" + depends on PPP + select CRYPTO_SHA1 + select CRYPTO_ARC4 + ---help--- + 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. - See http://pptpclient.sourceforge.net/ for information on - configuring PPTP clients and servers to utilize this method. + For more information please visit http://mppe-mppc.alphacron.de + + To compile this driver as a module, choose M here. The module will + be called ppp_mppe_mppc.ko. config PPPOE tristate "PPP over Ethernet (EXPERIMENTAL)" --- linux-2.6.19.2/drivers/net/Makefile.orig 2009-07-22 15:44:09.000000000 +0200 +++ linux-2.6.19.2/drivers/net/Makefile 2010-01-24 20:14:13.000000000 +0100 @@ -122,7 +122,7 @@ 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) += ppp_mppe.o +obj-$(CONFIG_PPP_MPPE_MPPC) += ppp_mppe_mppc.o obj-$(CONFIG_PPPOE) += pppox.o pppoe.o obj-$(CONFIG_SLIP) += slip.o --- linux-2.6.19.2/drivers/net/ppp_generic.c.orig 2010-01-24 20:14:12.000000000 +0100 +++ linux-2.6.19.2/drivers/net/ppp_generic.c 2010-01-24 20:14:13.000000000 +0100 @@ -19,7 +19,7 @@ * PPP driver, written by Michael Callahan and Al Longyear, and * subsequently hacked by Paul Mackerras. * - * ==FILEVERSION 20041108== + * ==FILEVERSION 20050110== */ #include @@ -104,6 +104,7 @@ 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 */ @@ -136,14 +137,13 @@ /* * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC, - * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP, - * SC_MUST_COMP + * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP. * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR. * Bits in xstate: SC_COMP_RUN */ #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \ |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \ - |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP) + |SC_COMP_TCP|SC_REJ_COMP_TCP) /* * Private data structure for each channel. @@ -629,7 +629,9 @@ case PPPIOCSMRU: if (get_user(val, p)) 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; @@ -1017,56 +1019,6 @@ ppp_xmit_unlock(ppp); } -static inline struct sk_buff * -pad_compress_skb(struct ppp *ppp, struct sk_buff *skb) -{ - struct sk_buff *new_skb; - int len; - int new_skb_size = ppp->dev->mtu + - ppp->xcomp->comp_extra + ppp->dev->hard_header_len; - int compressor_skb_size = ppp->dev->mtu + - ppp->xcomp->comp_extra + PPP_HDRLEN; - new_skb = alloc_skb(new_skb_size, GFP_ATOMIC); - if (!new_skb) { - if (net_ratelimit()) - printk(KERN_ERR "PPP: no memory (comp pkt)\n"); - return NULL; - } - if (ppp->dev->hard_header_len > PPP_HDRLEN) - skb_reserve(new_skb, - ppp->dev->hard_header_len - PPP_HDRLEN); - - /* compressor still expects A/C bytes in hdr */ - len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2, - new_skb->data, skb->len + 2, - compressor_skb_size); - if (len > 0 && (ppp->flags & SC_CCP_UP)) { - kfree_skb(skb); - skb = new_skb; - skb_put(skb, len); - skb_pull(skb, 2); /* pull off A/C bytes */ - } else if (len == 0) { - /* didn't compress, or CCP not up yet */ - kfree_skb(new_skb); - new_skb = 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. - */ - if (net_ratelimit()) - printk(KERN_ERR "ppp: compressor dropped pkt\n"); - kfree_skb(skb); - kfree_skb(new_skb); - new_skb = NULL; - } - return new_skb; -} - /* * Compress and send a frame. * The caller should have locked the xmit path, @@ -1147,20 +1099,70 @@ 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) { - if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) { - if (net_ratelimit()) - printk(KERN_ERR "ppp: compression required but down - pkt dropped.\n"); + 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; } - skb = pad_compress_skb(ppp, skb); - if (!skb) + if (ppp->dev->hard_header_len > PPP_HDRLEN) + skb_reserve(new_skb, + ppp->dev->hard_header_len - PPP_HDRLEN); + + /* compressor still expects A/C bytes in hdr */ + len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2, + new_skb->data, skb->len + 2, + ppp->dev->mtu + PPP_HDRLEN); + if (len > 0 && (ppp->flags & SC_CCP_UP)) { + kfree_skb(skb); + skb = new_skb; + skb_put(skb, len); + skb_pull(skb, 2); /* pull off A/C bytes */ + } 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; + } } /* @@ -1180,8 +1182,7 @@ return; drop: - if (skb) - kfree_skb(skb); + kfree_skb(skb); ++ppp->stats.tx_errors; } @@ -1578,9 +1579,6 @@ && (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0) skb = ppp_decompress_frame(ppp, skb); - if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR) - goto err; - proto = PPP_PROTO(skb); switch (proto) { case PPP_VJC_COMP: @@ -1711,14 +1709,15 @@ goto err; 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. */ @@ -1744,7 +1743,14 @@ 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; } @@ -2415,6 +2421,7 @@ goto out1; 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) --- linux-2.6.19.2/drivers/net/ppp_mppe.c.orig 2007-01-11 08:38:19.000000000 +0100 +++ linux-2.6.19.2/drivers/net/ppp_mppe.c 1970-01-01 01:00:00.000000000 +0100 @@ -1,739 +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 . - * 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 - * Only need extra skb padding on transmit, not receive. - * 06/18/04 - Matt Domsch , Oleg Makarenko - * Use Linux kernel 2.6 arc4 and sha1 routines rather than - * providing our own. - * 2/15/04 - TS: added #include and testing for Kernel - * version before using - * MOD_DEC_USAGE_COUNT/MOD_INC_USAGE_COUNT which are - * deprecated in 2.6 - */ - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#include "ppp_mppe.h" - -MODULE_AUTHOR("Frank Cusack "); -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[0].page = virt_to_page(address); - sg[0].offset = offset_in_page(address); - sg[0].length = 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, unsigned char *InterimKey) -{ - struct hash_desc desc; - struct scatterlist sg[4]; - unsigned int nbytes; - - 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); - - memcpy(InterimKey, state->sha1_digest, state->keylen); -} - -/* - * 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) -{ - unsigned char InterimKey[MPPE_MAX_KEY_LEN]; - struct scatterlist sg_in[1], sg_out[1]; - struct blkcipher_desc desc = { .tfm = state->arc4 }; - - get_new_key_from_sha(state, InterimKey); - if (!initial_key) { - crypto_blkcipher_setkey(state->arc4, InterimKey, state->keylen); - setup_sg(sg_in, InterimKey, 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, InterimKey, 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 = (struct ppp_mppe_state *) kmalloc(sizeof(*state), GFP_KERNEL); - if (state == NULL) - goto out; - - memset(state, 0, sizeof(*state)); - - 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); - obuf[2] = PPP_COMP >> 8; /* isize + MPPE_OVHD + 1 */ - obuf[3] = PPP_COMP; /* isize + MPPE_OVHD + 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); - obuf[0] = state->ccount >> 8; - obuf[1] = state->ccount & 0xff; - - 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 */ - 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. - */ - 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); --- linux-2.6.19.2/drivers/net/ppp_mppe.h.orig 2007-01-11 08:38:19.000000000 +0100 +++ linux-2.6.19.2/drivers/net/ppp_mppe.h 1970-01-01 01:00:00.000000000 +0100 @@ -1,86 +0,0 @@ -#define MPPE_PAD 4 /* MPPE growth per frame */ -#define MPPE_MAX_KEY_LEN 16 /* largest key length (128-bit) */ - -/* option bits for ccp_options.mppe */ -#define MPPE_OPT_40 0x01 /* 40 bit */ -#define MPPE_OPT_128 0x02 /* 128 bit */ -#define MPPE_OPT_STATEFUL 0x04 /* stateful mode */ -/* unsupported opts */ -#define MPPE_OPT_56 0x08 /* 56 bit */ -#define MPPE_OPT_MPPC 0x10 /* MPPC compression */ -#define MPPE_OPT_D 0x20 /* Unknown */ -#define MPPE_OPT_UNSUPPORTED (MPPE_OPT_56|MPPE_OPT_MPPC|MPPE_OPT_D) -#define MPPE_OPT_UNKNOWN 0x40 /* Bits !defined in RFC 3078 were set */ - -/* - * This is not nice ... the alternative is a bitfield struct though. - * And unfortunately, we cannot share the same bits for the option - * names above since C and H are the same bit. We could do a u_int32 - * but then we have to do a htonl() all the time and/or we still need - * to know which octet is which. - */ -#define MPPE_C_BIT 0x01 /* MPPC */ -#define MPPE_D_BIT 0x10 /* Obsolete, usage unknown */ -#define MPPE_L_BIT 0x20 /* 40-bit */ -#define MPPE_S_BIT 0x40 /* 128-bit */ -#define MPPE_M_BIT 0x80 /* 56-bit, not supported */ -#define MPPE_H_BIT 0x01 /* Stateless (in a different byte) */ - -/* Does not include H bit; used for least significant octet only. */ -#define MPPE_ALL_BITS (MPPE_D_BIT|MPPE_L_BIT|MPPE_S_BIT|MPPE_M_BIT|MPPE_H_BIT) - -/* Build a CI from mppe opts (see RFC 3078) */ -#define MPPE_OPTS_TO_CI(opts, ci) \ - do { \ - u_char *ptr = ci; /* u_char[4] */ \ - \ - /* H bit */ \ - if (opts & MPPE_OPT_STATEFUL) \ - *ptr++ = 0x0; \ - else \ - *ptr++ = MPPE_H_BIT; \ - *ptr++ = 0; \ - *ptr++ = 0; \ - \ - /* S,L bits */ \ - *ptr = 0; \ - if (opts & MPPE_OPT_128) \ - *ptr |= MPPE_S_BIT; \ - if (opts & MPPE_OPT_40) \ - *ptr |= MPPE_L_BIT; \ - /* M,D,C bits not supported */ \ - } while (/* CONSTCOND */ 0) - -/* The reverse of the above */ -#define MPPE_CI_TO_OPTS(ci, opts) \ - do { \ - u_char *ptr = ci; /* u_char[4] */ \ - \ - opts = 0; \ - \ - /* H bit */ \ - if (!(ptr[0] & MPPE_H_BIT)) \ - opts |= MPPE_OPT_STATEFUL; \ - \ - /* S,L bits */ \ - if (ptr[3] & MPPE_S_BIT) \ - opts |= MPPE_OPT_128; \ - if (ptr[3] & MPPE_L_BIT) \ - opts |= MPPE_OPT_40; \ - \ - /* M,D,C bits */ \ - if (ptr[3] & MPPE_M_BIT) \ - opts |= MPPE_OPT_56; \ - if (ptr[3] & MPPE_D_BIT) \ - opts |= MPPE_OPT_D; \ - if (ptr[3] & MPPE_C_BIT) \ - opts |= MPPE_OPT_MPPC; \ - \ - /* Other bits */ \ - if (ptr[0] & ~MPPE_H_BIT) \ - opts |= MPPE_OPT_UNKNOWN; \ - if (ptr[1] || ptr[2]) \ - opts |= MPPE_OPT_UNKNOWN; \ - if (ptr[3] & ~MPPE_ALL_BITS) \ - opts |= MPPE_OPT_UNKNOWN; \ - } while (/* CONSTCOND */ 0) --- linux-2.6.19.2/drivers/net/ppp_mppe_mppc.c.orig 1970-01-01 01:00:00.000000000 +0100 +++ linux-2.6.19.2/drivers/net/ppp_mppe_mppc.c 2010-01-24 20:14:13.000000000 +0100 @@ -0,0 +1,1299 @@ +/* + * ppp_mppe_mppc.c - MPPC/MPPE "compressor/decompressor" module. + * + * Copyright (c) 1994 Árpád Magosányi + * Copyright (c) 1999 Tim Hockin, Cobalt Networks Inc. + * Copyright (c) 2002-2004 Jan Dubiec + * + * 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 20041123== + * + */ + +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +/* + * 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() */ + } + + 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_digest != NULL) + kfree(state->sha1_digest); + 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); + } +} + +/* 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 = { + .compress_proto = CI_MPPE, + .comp_alloc = mppe_comp_alloc, + .comp_free = mppe_comp_free, + .comp_init = mppe_comp_init, + .comp_reset = mppe_comp_reset, + .compress = mppe_compress, + .comp_stat = mppe_stats, + .decomp_alloc = mppe_decomp_alloc, + .decomp_free = mppe_comp_free, + .decomp_init = mppe_decomp_init, + .decomp_reset = mppe_decomp_reset, + .decompress = mppe_decompress, + .incomp = NULL, + .decomp_stat = mppe_stats, + .owner = THIS_MODULE +}; + +/************************************************************ + * Module support routines + ************************************************************/ + +int __init mppe_module_init(void) +{ + int answer; + + 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 "); +MODULE_DESCRIPTION("MPPE/MPPC encryption/compression module for Linux"); +MODULE_VERSION("1.3"); +MODULE_LICENSE("Dual BSD/GPL"); +MODULE_ALIAS("ppp-compress-" __stringify(CI_MPPE)); --- linux-2.6.19.2/include/linux/if_ppp.h.orig 2007-01-11 08:38:19.000000000 +0100 +++ linux-2.6.19.2/include/linux/if_ppp.h 2010-01-24 20:14:13.000000000 +0100 @@ -21,7 +21,7 @@ */ /* - * ==FILEVERSION 20050812== + * ==FILEVERSION 20000724== * * NOTE TO MAINTAINERS: * If you modify this file at all, please set the above date. @@ -72,8 +72,7 @@ #define SC_LOG_RAWIN 0x00080000 /* log all chars received */ #define SC_LOG_FLUSH 0x00100000 /* log all chars flushed */ #define SC_SYNC 0x00200000 /* synchronous serial mode */ -#define SC_MUST_COMP 0x00400000 /* no uncompressed packets may be sent or received */ -#define SC_MASK 0x0f600fff /* bits that user can change */ +#define SC_MASK 0x0f200fff /* bits that user can change */ /* state bits */ #define SC_XMIT_BUSY 0x10000000 /* (used by isdn_ppp?) */ --- linux-2.6.19.2/include/linux/ppp-comp.h.orig 2007-01-11 08:38:19.000000000 +0100 +++ linux-2.6.19.2/include/linux/ppp-comp.h 2010-01-24 20:14:13.000000000 +0100 @@ -28,7 +28,7 @@ */ /* - * ==FILEVERSION 980319== + * ==FILEVERSION 20040509== * * NOTE TO MAINTAINERS: * If you modify this file at all, please set the above date. @@ -80,7 +80,7 @@ /* 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); @@ -101,7 +101,7 @@ /* 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); @@ -111,8 +111,6 @@ /* Used in locking compressor modules */ struct module *owner; - /* Extra skb space needed by the compressor algorithm */ - unsigned int comp_extra; }; /* @@ -193,11 +191,40 @@ #define DEFLATE_CHK_SEQUENCE 0 /* - * Definitions for MPPE. + * Definitions for MPPE/MPPC. */ -#define CI_MPPE 18 /* config option for MPPE */ -#define CILEN_MPPE 6 /* length of config option */ +#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.