diff options
Diffstat (limited to 'recipes/linux/linux-mtx-2-2.4.27/39-mppe-mpc.patch')
| -rw-r--r-- | recipes/linux/linux-mtx-2-2.4.27/39-mppe-mpc.patch | 1665 |
1 files changed, 1665 insertions, 0 deletions
diff --git a/recipes/linux/linux-mtx-2-2.4.27/39-mppe-mpc.patch b/recipes/linux/linux-mtx-2-2.4.27/39-mppe-mpc.patch new file mode 100644 index 0000000000..28ce19d467 --- /dev/null +++ b/recipes/linux/linux-mtx-2-2.4.27/39-mppe-mpc.patch @@ -0,0 +1,1665 @@ +diff -ruN linux.orig/Documentation/Configure.help linux/Documentation/Configure.help +--- linux.orig/Documentation/Configure.help 2004-08-08 12:14:49.000000000 +0200 ++++ linux/Documentation/Configure.help 2004-08-15 09:22:18.000000000 +0200 +@@ -9905,6 +9905,28 @@ + module; it is called bsd_comp.o and will show up in the directory + modules once you have said "make modules". If unsure, say N. + ++Microsoft PPP compression/encryption (MPPC/MPPE) ++CONFIG_PPP_MPPE_MPPC ++ Support for the Microsoft Point-To-Point Compression (RFC2118) and ++ Microsoft Point-To-Point Encryption (RFC3078). These protocols are ++ supported by Microsoft Windows and wide range of "hardware" access ++ servers. MPPE is common protocol in Virtual Private Networks. According ++ to RFC3078, MPPE supports 40, 56 and 128-bit key lengths. Depending on ++ PPP daemon configuration on both ends of the link, following scenarios ++ are possible: ++ - only compression (MPPC) is used, ++ - only encryption (MPPE) is used, ++ - compression and encryption (MPPC+MPPE) are used. ++ ++ Please note that Hi/Fn (http://www.hifn.com) holds patent on MPPC so ++ you should check if this patent is valid in your country in order to ++ avoid legal problems. ++ ++ For more information please visit http://free.polbox.pl/h/hs001 ++ ++ To compile this driver as a module, choose M here. The module will ++ be called ppp_mppe_mppc.o. ++ + PPP over Ethernet + CONFIG_PPPOE + Support for PPP over Ethernet. +diff -ruN linux.orig/crypto/Config.in linux/crypto/Config.in +--- linux.orig/crypto/Config.in 2004-08-08 12:14:50.000000000 +0200 ++++ linux/crypto/Config.in 2004-08-15 11:36:18.000000000 +0200 +@@ -11,7 +11,9 @@ + "$CONFIG_INET6_AH" = "y" -o \ + "$CONFIG_INET6_AH" = "m" -o \ + "$CONFIG_INET6_ESP" = "y" -o \ +- "$CONFIG_INET6_ESP" = "m" ]; then ++ "$CONFIG_INET6_ESP" = "m" -o \ ++ "$CONFIG_PPP_MPPE_MPPC" = "y" -o \ ++ "$CONFIG_PPP_MPPE_MPPC" = "m" ]; then + define_bool CONFIG_CRYPTO y + else + bool 'Cryptographic API' CONFIG_CRYPTO +@@ -44,6 +46,7 @@ + else + tristate ' MD5 digest algorithm' CONFIG_CRYPTO_MD5 + fi ++ + if [ "$CONFIG_INET_AH" = "y" -o \ + "$CONFIG_INET_AH" = "m" -o \ + "$CONFIG_INET_ESP" = "y" -o \ +@@ -51,11 +54,24 @@ + "$CONFIG_INET6_AH" = "y" -o \ + "$CONFIG_INET6_AH" = "m" -o \ + "$CONFIG_INET6_ESP" = "y" -o \ +- "$CONFIG_INET6_ESP" = "m" ]; then +- define_bool CONFIG_CRYPTO_SHA1 y +- else +- tristate ' SHA1 digest algorithm' CONFIG_CRYPTO_SHA1 ++ "$CONFIG_INET6_ESP" = "m" -o \ ++ "$CONFIG_PPP_MPPE_MPPC" = "y" -o \ ++ "$CONFIG_PPP_MPPE_MPPC" = "m" ]; then ++ if [ "$CONFIG_INET_AH" = "y" -o \ ++ "$CONFIG_INET_ESP" = "y" -o \ ++ "$CONFIG_INET6_AH" = "y" -o \ ++ "$CONFIG_INET6_ESP" = "y" -o \ ++ "$CONFIG_PPP_MPPE_MPPC" = "y" ]; then ++ define_tristate CONFIG_CRYPTO_SHA1 y ++ else ++ if [ "$CONFIG_CRYPTO_SHA1" != "y" -a \ ++ "$CONFIG_CRYPTO_SHA1" != "m" ]; then ++ define_tristate CONFIG_CRYPTO_SHA1 m ++ fi ++ fi + fi ++ tristate ' SHA1 digest algorithm' CONFIG_CRYPTO_SHA1 ++ + tristate ' SHA256 digest algorithm' CONFIG_CRYPTO_SHA256 + tristate ' SHA384 and SHA512 digest algorithms' CONFIG_CRYPTO_SHA512 + if [ "$CONFIG_INET_ESP" = "y" -o \ +@@ -73,7 +89,20 @@ + tristate ' CAST5 (CAST-128) cipher algorithm' CONFIG_CRYPTO_CAST5 + tristate ' CAST6 (CAST-256) cipher algorithm' CONFIG_CRYPTO_CAST6 + tristate ' TEA and XTEA cipher algorithms' CONFIG_CRYPTO_TEA ++ ++ if [ "$CONFIG_PPP_MPPE_MPPC" = "y" -o \ ++ "$CONFIG_PPP_MPPE_MPPC" = "m" ]; then ++ if [ "$CONFIG_PPP_MPPE_MPPC" = "y" ]; then ++ define_tristate CONFIG_CRYPTO_ARC4 y ++ else ++ if [ "$CONFIG_CRYPTO_ARC4" != "y" -a \ ++ "$CONFIG_CRYPTO_ARC4" != "m" ]; then ++ define_tristate CONFIG_CRYPTO_ARC4 m ++ fi ++ fi ++ fi + tristate ' ARC4 cipher algorithm' CONFIG_CRYPTO_ARC4 ++ + if [ "$CONFIG_INET_IPCOMP" = "y" -o \ + "$CONFIG_INET_IPCOMP" = "m" -o \ + "$CONFIG_INET6_IPCOMP" = "y" -o \ +diff -ruN linux.orig/drivers/net/Config.in linux/drivers/net/Config.in +--- linux.orig/drivers/net/Config.in 2004-08-08 12:14:52.000000000 +0200 ++++ linux/drivers/net/Config.in 2004-08-08 12:17:43.000000000 +0200 +@@ -325,6 +325,7 @@ + dep_tristate ' PPP support for sync tty ports' CONFIG_PPP_SYNC_TTY $CONFIG_PPP + dep_tristate ' PPP Deflate compression' CONFIG_PPP_DEFLATE $CONFIG_PPP + dep_tristate ' PPP BSD-Compress compression' CONFIG_PPP_BSDCOMP $CONFIG_PPP ++ dep_tristate ' Microsoft PPP compression/encryption (MPPC/MPPE)' CONFIG_PPP_MPPE_MPPC $CONFIG_PPP + if [ "$CONFIG_EXPERIMENTAL" = "y" ]; then + dep_tristate ' PPP over Ethernet (EXPERIMENTAL)' CONFIG_PPPOE $CONFIG_PPP + fi +diff -ruN linux.orig/drivers/net/Makefile linux/drivers/net/Makefile +--- linux.orig/drivers/net/Makefile 2004-08-08 12:14:52.000000000 +0200 ++++ linux/drivers/net/Makefile 2004-08-08 12:17:43.000000000 +0200 +@@ -161,6 +161,7 @@ + obj-$(CONFIG_PPP_SYNC_TTY) += ppp_synctty.o + obj-$(CONFIG_PPP_DEFLATE) += ppp_deflate.o + obj-$(CONFIG_PPP_BSDCOMP) += bsd_comp.o ++obj-$(CONFIG_PPP_MPPE_MPPC) += ppp_mppe_mppc.o + obj-$(CONFIG_PPPOE) += pppox.o pppoe.o + + obj-$(CONFIG_SLIP) += slip.o +diff -ruN linux.orig/drivers/net/ppp_generic.c linux/drivers/net/ppp_generic.c +--- linux.orig/drivers/net/ppp_generic.c 2003-08-25 13:44:42.000000000 +0200 ++++ linux/drivers/net/ppp_generic.c 2004-08-08 12:17:43.000000000 +0200 +@@ -19,7 +19,7 @@ + * PPP driver, written by Michael Callahan and Al Longyear, and + * subsequently hacked by Paul Mackerras. + * +- * ==FILEVERSION 20020217== ++ * ==FILEVERSION 20040509== + */ + + #include <linux/config.h> +@@ -102,6 +102,7 @@ + spinlock_t rlock; /* lock for receive side 58 */ + spinlock_t wlock; /* lock for transmit side 5c */ + int mru; /* max receive unit 60 */ ++ int mru_alloc; /* MAX(1500,MRU) for dev_alloc_skb() */ + unsigned int flags; /* control bits 64 */ + unsigned int xstate; /* transmit state bits 68 */ + unsigned int rstate; /* receive state bits 6c */ +@@ -552,7 +553,9 @@ + case PPPIOCSMRU: + if (get_user(val, (int *) arg)) + break; +- ppp->mru = val; ++ ppp->mru_alloc = ppp->mru = val; ++ if (ppp->mru_alloc < PPP_MRU) ++ ppp->mru_alloc = PPP_MRU; /* increase for broken peers */ + err = 0; + break; + +@@ -1025,14 +1028,37 @@ + case PPP_CCP: + /* peek at outbound CCP frames */ + ppp_ccp_peek(ppp, skb, 0); ++ /* ++ * When LZS or MPPE/MPPC has been negotiated we don't send ++ * CCP_RESETACK after receiving CCP_RESETREQ; in fact pppd ++ * sends such a packet but we silently discard it here ++ */ ++ if (CCP_CODE(skb->data+2) == CCP_RESETACK ++ && (ppp->xcomp->compress_proto == CI_MPPE ++ || ppp->xcomp->compress_proto == CI_LZS)) { ++ --ppp->stats.tx_packets; ++ ppp->stats.tx_bytes -= skb->len - 2; ++ kfree_skb(skb); ++ return; ++ } + break; + } + + /* try to do packet compression */ + if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state != 0 + && proto != PPP_LCP && proto != PPP_CCP) { +- new_skb = alloc_skb(ppp->dev->mtu + ppp->dev->hard_header_len, +- GFP_ATOMIC); ++ int comp_ovhd = 0; ++ /* ++ * because of possible data expansion when MPPC or LZS ++ * is used, allocate compressor's buffer 12.5% bigger ++ * than MTU ++ */ ++ if (ppp->xcomp->compress_proto == CI_MPPE) ++ comp_ovhd = ((ppp->dev->mtu * 9) / 8) + 1 + MPPE_OVHD; ++ else if (ppp->xcomp->compress_proto == CI_LZS) ++ comp_ovhd = ((ppp->dev->mtu * 9) / 8) + 1 + LZS_OVHD; ++ new_skb = alloc_skb(ppp->dev->mtu + ppp->dev->hard_header_len ++ + comp_ovhd, GFP_ATOMIC); + if (new_skb == 0) { + printk(KERN_ERR "PPP: no memory (comp pkt)\n"); + goto drop; +@@ -1050,9 +1076,21 @@ + skb = new_skb; + skb_put(skb, len); + skb_pull(skb, 2); /* pull off A/C bytes */ +- } else { ++ } else if (len == 0) { + /* didn't compress, or CCP not up yet */ + kfree_skb(new_skb); ++ } else { ++ /* ++ * (len < 0) ++ * MPPE requires that we do not send unencrypted ++ * frames. The compressor will return -1 if we ++ * should drop the frame. We cannot simply test ++ * the compress_proto because MPPE and MPPC share ++ * the same number. ++ */ ++ printk(KERN_ERR "ppp: compressor dropped pkt\n"); ++ kfree_skb(new_skb); ++ goto drop; + } + } + +@@ -1540,14 +1578,15 @@ + int len; + + if (proto == PPP_COMP) { +- ns = dev_alloc_skb(ppp->mru + PPP_HDRLEN); ++ ns = dev_alloc_skb(ppp->mru_alloc + PPP_HDRLEN); + if (ns == 0) { + printk(KERN_ERR "ppp_decompress_frame: no memory\n"); + goto err; + } + /* the decompressor still expects the A/C bytes in the hdr */ + len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2, +- skb->len + 2, ns->data, ppp->mru + PPP_HDRLEN); ++ skb->len + 2, ns->data, ++ ppp->mru_alloc + PPP_HDRLEN); + if (len < 0) { + /* Pass the compressed frame to pppd as an + error indication. */ +@@ -1573,7 +1612,14 @@ + return skb; + + err: +- ppp->rstate |= SC_DC_ERROR; ++ if (ppp->rcomp->compress_proto != CI_MPPE ++ && ppp->rcomp->compress_proto != CI_LZS) { ++ /* ++ * If decompression protocol isn't MPPE/MPPC or LZS, we set ++ * SC_DC_ERROR flag and wait for CCP_RESETACK ++ */ ++ ppp->rstate |= SC_DC_ERROR; ++ } + ppp_receive_error(ppp); + return skb; + } +@@ -2253,6 +2299,7 @@ + /* Initialize the new ppp unit */ + ppp->file.index = unit; + ppp->mru = PPP_MRU; ++ ppp->mru_alloc = PPP_MRU; + init_ppp_file(&ppp->file, INTERFACE); + ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */ + for (i = 0; i < NUM_NP; ++i) +diff -ruN linux.orig/drivers/net/ppp_mppe_mppc.c linux/drivers/net/ppp_mppe_mppc.c +--- linux.orig/drivers/net/ppp_mppe_mppc.c 1970-01-01 01:00:00.000000000 +0100 ++++ linux/drivers/net/ppp_mppe_mppc.c 2004-08-15 10:12:23.000000000 +0200 +@@ -0,0 +1,1269 @@ ++/* ++ * ppp_mppe_mppc.c - MPPC/MPPE "compressor/decompressor" module. ++ * ++ * Copyright (c) 1994 Árpád Magosányi <mag@bunuel.tii.matav.hu> ++ * Copyright (c) 1999 Tim Hockin, Cobalt Networks Inc. <thockin@cobaltnet.com> ++ * Copyright (c) 2002-2004 Jan Dubiec <jdx@slackware.pl> ++ * ++ * Permission to use, copy, modify, and distribute this software and its ++ * documentation is hereby granted, provided that the above copyright ++ * notice appears in all copies. This software is provided without any ++ * warranty, express or implied. ++ * ++ * The code is based on MPPE kernel module written by Árpád Magosányi and ++ * Tim Hockin which can be found on http://planetmirror.com/pub/mppe/. ++ * I have added MPPC and 56 bit session keys support in MPPE. ++ * ++ * WARNING! Although this is open source code, its usage in some countries ++ * (in particular in the USA) may violate Stac Inc. patent for MPPC. ++ * ++ * ==FILEVERSION 20040815== ++ * ++ */ ++ ++#include <linux/init.h> ++#include <linux/module.h> ++#include <linux/mm.h> ++#include <linux/slab.h> ++#include <asm/scatterlist.h> ++#include <linux/vmalloc.h> ++#include <linux/crypto.h> ++ ++#include <linux/ppp_defs.h> ++#include <linux/ppp-comp.h> ++ ++/* ++ * In 2.4.x kernels macro offset_in_page() is not defined in linux/mm.h so ++ * we define it here; PAGE_MASK is defined in asm/page.h which is included ++ * by linux/mm.h. ++ */ ++#define offset_in_page(p) ((unsigned long)(p) & ~PAGE_MASK) ++ ++/* ++ * State for a mppc/mppe "(de)compressor". ++ */ ++struct ppp_mppe_state { ++ struct crypto_tfm *arc4_tfm; ++ struct crypto_tfm *sha1_tfm; ++ u8 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) ++ ++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 ++GetNewKeyFromSHA(struct ppp_mppe_state *state, unsigned char *MasterKey, ++ unsigned char *SessionKey, unsigned long SessionKeyLength, ++ unsigned char *InterimKey) ++{ ++ /*Pads used in key derivation */ ++ static const unsigned char SHAPad1[40] = { ++ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, ++ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, ++ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, ++ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 ++ }; ++ ++ static const unsigned char SHAPad2[40] = { ++ 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, ++ 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, ++ 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, ++ 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2, 0xf2 ++ }; ++ ++ unsigned char Digest[20]; /* SHA1_DIGEST_SIZE = 20 */ ++ struct scatterlist sg[2]; ++ ++ crypto_digest_init(state->sha1_tfm); ++ ++ setup_sg(sg, MasterKey, SessionKeyLength); ++ crypto_digest_update(state->sha1_tfm, sg, 1); ++ ++ setup_sg(sg, SHAPad1, sizeof(SHAPad1)); ++ crypto_digest_update(state->sha1_tfm, sg, 1); ++ ++ setup_sg(sg, SessionKey, SessionKeyLength); ++ crypto_digest_update(state->sha1_tfm, sg, 1); ++ ++ setup_sg(sg, SHAPad2, sizeof(SHAPad2)); ++ crypto_digest_update(state->sha1_tfm, sg, 1); ++ ++ crypto_digest_final(state->sha1_tfm, Digest); ++ ++ memcpy(InterimKey, Digest, SessionKeyLength); ++} ++ ++static void ++mppe_change_key(struct ppp_mppe_state *state, int initialize) ++{ ++ unsigned char InterimKey[MPPE_MAX_KEY_LEN]; ++ ++ GetNewKeyFromSHA(state, state->master_key, state->session_key, ++ state->keylen, InterimKey); ++ if (initialize) { ++ memcpy(state->session_key, InterimKey, state->keylen); ++ } else { ++ arc4_setkey(state, InterimKey, state->keylen); ++ arc4_encrypt(state, InterimKey, 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; ++ 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 SHA1 algorithm */ ++ state->sha1_tfm = crypto_alloc_tfm("sha1", 0); ++ if (state->sha1_tfm == NULL) { ++ vfree(state->hash); ++ vfree(state->hist); ++ kfree(state); ++ printk(KERN_ERR "%s: cannot load SHA1 module\n", fname); ++ return NULL; ++ } ++ ++ /* Load ARC4 algorithm */ ++ state->arc4_tfm = crypto_alloc_tfm("arc4", 0); ++ if (state->arc4_tfm == NULL) { ++ crypto_free_tfm(state->sha1_tfm); ++ vfree(state->hash); ++ vfree(state->hist); ++ kfree(state); ++ printk(KERN_ERR "%s: cannot load ARC4 module\n", fname); ++ return NULL; ++ } ++ ++ memcpy(state->master_key, options+CILEN_MPPE, MPPE_MAX_KEY_LEN); ++ memcpy(state->session_key, state->master_key, MPPE_MAX_KEY_LEN); ++ /* initial key generation is done in mppe_init() */ ++ } ++ ++ MOD_INC_USE_COUNT; ++ ++ return (void *) state; ++} ++ ++static void * ++mppe_comp_alloc(unsigned char *options, int opt_len) ++{ ++ return mppe_alloc(options, opt_len, 1); ++} ++ ++static void * ++mppe_decomp_alloc(unsigned char *options, int opt_len) ++{ ++ return mppe_alloc(options, opt_len, 0); ++} ++ ++/* cleanup the (de)compressor */ ++static void ++mppe_comp_free(void *arg) ++{ ++ struct ppp_mppe_state *state = (struct ppp_mppe_state *) arg; ++ ++ if (state != NULL) { ++ if (state->mppe) { ++ if (state->sha1_tfm != NULL) ++ crypto_free_tfm(state->sha1_tfm); ++ if (state->arc4_tfm != NULL) ++ crypto_free_tfm(state->arc4_tfm); ++ } ++ if (state->hist != NULL) ++ vfree(state->hist); ++ if (state->hash != NULL) ++ vfree(state->hash); ++ kfree(state); ++ } ++ ++ MOD_DEC_USE_COUNT; ++} ++ ++/* init MPPC/MPPE (de)compresor */ ++/* comp != 0 -> init compressor */ ++/* comp = 0 -> init decompressor */ ++static int ++mppe_init(void *arg, unsigned char *options, int opt_len, int unit, ++ int hdrlen, int mru, int debug, int comp) ++{ ++ struct ppp_mppe_state *state = (struct ppp_mppe_state *) arg; ++ u8* fname; ++ ++ fname = comp ? "mppe_comp_init" : "mppe_decomp_init"; ++ ++ if (opt_len < CILEN_MPPE) { ++ if (debug) ++ printk(KERN_WARNING "%s: wrong options length: %u\n", ++ fname, opt_len); ++ return 0; ++ } ++ ++ if (options[0] != CI_MPPE || options[1] != CILEN_MPPE || ++ (options[2] & ~MPPE_STATELESS) != 0 || ++ options[3] != 0 || options[4] != 0 || ++ (options[5] & ~(MPPE_56BIT|MPPE_128BIT|MPPE_40BIT|MPPE_MPPC)) != 0 || ++ (options[5] & (MPPE_56BIT|MPPE_128BIT|MPPE_40BIT|MPPE_MPPC)) == 0) { ++ if (debug) ++ printk(KERN_WARNING "%s: options rejected: o[0]=%02x, o[1]=%02x, " ++ "o[2]=%02x, o[3]=%02x, o[4]=%02x, o[5]=%02x\n", fname, ++ options[0], options[1], options[2], options[3], options[4], ++ options[5]); ++ return 0; ++ } ++ ++ if ((options[5] & ~MPPE_MPPC) != MPPE_128BIT && ++ (options[5] & ~MPPE_MPPC) != MPPE_56BIT && ++ (options[5] & ~MPPE_MPPC) != MPPE_40BIT && ++ (options[5] & MPPE_MPPC) != MPPE_MPPC) { ++ if (debug) ++ printk(KERN_WARNING "%s: don't know what to do: o[5]=%02x\n", ++ fname, options[5]); ++ return 0; ++ } ++ ++ state->mppc = options[5] & MPPE_MPPC; /* Do we use MPPC? */ ++ state->mppe = options[5] & (MPPE_128BIT | MPPE_56BIT | ++ MPPE_40BIT); /* Do we use MPPE? */ ++ state->stateless = options[2] & MPPE_STATELESS; /* Do we use stateless mode? */ ++ ++ switch (state->mppe) { ++ case MPPE_40BIT: /* 40 bit key */ ++ state->keylen = 8; ++ state->bitkeylen = 40; ++ break; ++ case MPPE_56BIT: /* 56 bit key */ ++ state->keylen = 8; ++ state->bitkeylen = 56; ++ break; ++ case MPPE_128BIT: /* 128 bit key */ ++ state->keylen = 16; ++ state->bitkeylen = 128; ++ break; ++ default: ++ state->keylen = 0; ++ state->bitkeylen = 0; ++ } ++ ++ state->ccount = MPPE_MAX_CCOUNT; ++ state->bits = 0; ++ state->unit = unit; ++ state->debug = debug; ++ state->histptr = MPPE_HIST_LEN; ++ if (state->mppc) { /* reset history if MPPC was negotiated */ ++ memset(state->hist, 0, 2*MPPE_HIST_LEN*sizeof(u8)); ++ } ++ ++ if (state->mppe) { /* generate initial session keys */ ++ mppe_change_key(state, 1); ++ } ++ ++ if (comp) { /* specific for compressor */ ++ state->nextflushed = 1; ++ } else { /* specific for decompressor */ ++ state->mru = mru; ++ state->flushexpected = 1; ++ } ++ ++ return 1; ++} ++ ++static int ++mppe_comp_init(void *arg, unsigned char *options, int opt_len, int unit, ++ int hdrlen, int debug) ++{ ++ return mppe_init(arg, options, opt_len, unit, hdrlen, 0, debug, 1); ++} ++ ++ ++static int ++mppe_decomp_init(void *arg, unsigned char *options, int opt_len, int unit, ++ int hdrlen, int mru, int debug) ++{ ++ return mppe_init(arg, options, opt_len, unit, hdrlen, mru, debug, 0); ++} ++ ++static void ++mppe_comp_reset(void *arg) ++{ ++ struct ppp_mppe_state *state = (struct ppp_mppe_state *)arg; ++ ++ if (state->debug) ++ printk(KERN_DEBUG "%s%d: resetting MPPC/MPPE compressor\n", ++ __FUNCTION__, state->unit); ++ ++ state->nextflushed = 1; ++ if (state->mppe) ++ arc4_setkey(state, state->session_key, state->keylen); ++} ++ ++static void ++mppe_decomp_reset(void *arg) ++{ ++ /* When MPPC/MPPE is in use, we shouldn't receive any CCP Reset-Ack. ++ But when we receive such a packet, we just ignore it. */ ++ return; ++} ++ ++static void ++mppe_stats(void *arg, struct compstat *stats) ++{ ++ struct ppp_mppe_state *state = (struct ppp_mppe_state *)arg; ++ ++ *stats = state->stats; ++} ++ ++/***************************/ ++/**** Compression stuff ****/ ++/***************************/ ++/* inserts 1 to 8 bits into the output buffer */ ++static inline void putbits8(u8 *buf, u32 val, const u32 n, u32 *i, u32 *l) ++{ ++ buf += *i; ++ if (*l >= n) { ++ *l = (*l) - n; ++ val <<= *l; ++ *buf = *buf | (val & 0xff); ++ if (*l == 0) { ++ *l = 8; ++ (*i)++; ++ *(++buf) = 0; ++ } ++ } else { ++ (*i)++; ++ *l = 8 - n + (*l); ++ val <<= *l; ++ *buf = *buf | ((val >> 8) & 0xff); ++ *(++buf) = val & 0xff; ++ } ++} ++ ++/* inserts 9 to 16 bits into the output buffer */ ++static inline void putbits16(u8 *buf, u32 val, const u32 n, u32 *i, u32 *l) ++{ ++ buf += *i; ++ if (*l >= n - 8) { ++ (*i)++; ++ *l = 8 - n + (*l); ++ val <<= *l; ++ *buf = *buf | ((val >> 8) & 0xff); ++ *(++buf) = val & 0xff; ++ if (*l == 0) { ++ *l = 8; ++ (*i)++; ++ *(++buf) = 0; ++ } ++ } else { ++ (*i)++; (*i)++; ++ *l = 16 - n + (*l); ++ val <<= *l; ++ *buf = *buf | ((val >> 16) & 0xff); ++ *(++buf) = (val >> 8) & 0xff; ++ *(++buf) = val & 0xff; ++ } ++} ++ ++/* inserts 17 to 24 bits into the output buffer */ ++static inline void putbits24(u8 *buf, u32 val, const u32 n, u32 *i, u32 *l) ++{ ++ buf += *i; ++ if (*l >= n - 16) { ++ (*i)++; (*i)++; ++ *l = 16 - n + (*l); ++ val <<= *l; ++ *buf = *buf | ((val >> 16) & 0xff); ++ *(++buf) = (val >> 8) & 0xff; ++ *(++buf) = val & 0xff; ++ if (*l == 0) { ++ *l = 8; ++ (*i)++; ++ *(++buf) = 0; ++ } ++ } else { ++ (*i)++; (*i)++; (*i)++; ++ *l = 24 - n + (*l); ++ val <<= *l; ++ *buf = *buf | ((val >> 24) & 0xff); ++ *(++buf) = (val >> 16) & 0xff; ++ *(++buf) = (val >> 8) & 0xff; ++ *(++buf) = val & 0xff; ++ } ++} ++ ++static int ++mppc_compress(struct ppp_mppe_state *state, unsigned char *ibuf, ++ unsigned char *obuf, int isize, int osize) ++{ ++ u32 olen, off, len, idx, i, l; ++ u8 *hist, *sbuf, *p, *q, *r, *s; ++ ++ /* ++ At this point, to avoid possible buffer overflow caused by packet ++ expansion during/after compression, we should make sure that ++ osize >= (((isize*9)/8)+1)+2, but we don't do that because in ++ ppp_generic.c we simply allocate bigger obuf. ++ ++ Maximum MPPC packet expansion is 12.5%. This is the worst case when ++ all octets in the input buffer are >= 0x80 and we cannot find any ++ repeated tokens. Additionally we have to reserve 2 bytes for MPPE/MPPC ++ status bits and coherency counter. ++ */ ++ ++ hist = state->hist + MPPE_HIST_LEN; ++ /* check if there is enough room at the end of the history */ ++ if (state->histptr + isize >= 2*MPPE_HIST_LEN) { ++ state->bits |= MPPE_BIT_RESET; ++ state->histptr = MPPE_HIST_LEN; ++ memcpy(state->hist, hist, MPPE_HIST_LEN); ++ } ++ /* add packet to the history; isize must be <= MPPE_HIST_LEN */ ++ sbuf = state->hist + state->histptr; ++ memcpy(sbuf, ibuf, isize); ++ state->histptr += isize; ++ ++ /* compress data */ ++ r = sbuf + isize; ++ *obuf = olen = i = 0; ++ l = 8; ++ while (i < isize - 2) { ++ s = q = sbuf + i; ++ idx = ((40543*((((s[0]<<4)^s[1])<<4)^s[2]))>>4) & 0x1fff; ++ p = hist + state->hash[idx]; ++ state->hash[idx] = (u16) (s - hist); ++ off = s - p; ++ if (off > MPPE_HIST_LEN - 1 || off < 1 || *p++ != *s++ || *p++ != *s++ || ++ *p++ != *s++) { ++ /* no match found; encode literal byte */ ++ if (ibuf[i] < 0x80) { /* literal byte < 0x80 */ ++ putbits8(obuf, (u32) ibuf[i], 8, &olen, &l); ++ } else { /* literal byte >= 0x80 */ ++ putbits16(obuf, (u32) (0x100|(ibuf[i]&0x7f)), 9, &olen, &l); ++ } ++ ++i; ++ continue; ++ } ++ if (r - q >= 64) { ++ *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || ++ *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || ++ *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || ++ *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || ++ *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || ++ *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || ++ *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || ++ *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || ++ *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || ++ *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || ++ *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || ++ *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || ++ *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || ++ *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || ++ *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || *p++ != *s++ || ++ *p++ != *s++; ++ if (s - q == 64) { ++ p--; s--; ++ while((*p++ == *s++) && (s < r) && (p < q)); ++ } ++ } else { ++ while((*p++ == *s++) && (s < r) && (p < q)); ++ } ++ len = s - q - 1; ++ i += len; ++ ++ /* at least 3 character match found; code data */ ++ /* encode offset */ ++ if (off < 64) { /* 10-bit offset; 0 <= offset < 64 */ ++ putbits16(obuf, 0x3c0|off, 10, &olen, &l); ++ } else if (off < 320) { /* 12-bit offset; 64 <= offset < 320 */ ++ putbits16(obuf, 0xe00|(off-64), 12, &olen, &l); ++ } else if (off < 8192) { /* 16-bit offset; 320 <= offset < 8192 */ ++ putbits16(obuf, 0xc000|(off-320), 16, &olen, &l); ++ } else { ++ /* This shouldn't happen; we return 0 what means "packet expands", ++ and we send packet uncompressed. */ ++ if (state->debug) ++ printk(KERN_DEBUG "%s%d: wrong offset value: %d\n", ++ __FUNCTION__, state->unit, off); ++ return 0; ++ } ++ /* encode length of match */ ++ if (len < 4) { /* length = 3 */ ++ putbits8(obuf, 0, 1, &olen, &l); ++ } else if (len < 8) { /* 4 <= length < 8 */ ++ putbits8(obuf, 0x08|(len&0x03), 4, &olen, &l); ++ } else if (len < 16) { /* 8 <= length < 16 */ ++ putbits8(obuf, 0x30|(len&0x07), 6, &olen, &l); ++ } else if (len < 32) { /* 16 <= length < 32 */ ++ putbits8(obuf, 0xe0|(len&0x0f), 8, &olen, &l); ++ } else if (len < 64) { /* 32 <= length < 64 */ ++ putbits16(obuf, 0x3c0|(len&0x1f), 10, &olen, &l); ++ } else if (len < 128) { /* 64 <= length < 128 */ ++ putbits16(obuf, 0xf80|(len&0x3f), 12, &olen, &l); ++ } else if (len < 256) { /* 128 <= length < 256 */ ++ putbits16(obuf, 0x3f00|(len&0x7f), 14, &olen, &l); ++ } else if (len < 512) { /* 256 <= length < 512 */ ++ putbits16(obuf, 0xfe00|(len&0xff), 16, &olen, &l); ++ } else if (len < 1024) { /* 512 <= length < 1024 */ ++ putbits24(obuf, 0x3fc00|(len&0x1ff), 18, &olen, &l); ++ } else if (len < 2048) { /* 1024 <= length < 2048 */ ++ putbits24(obuf, 0xff800|(len&0x3ff), 20, &olen, &l); ++ } else if (len < 4096) { /* 2048 <= length < 4096 */ ++ putbits24(obuf, 0x3ff000|(len&0x7ff), 22, &olen, &l); ++ } else if (len < 8192) { /* 4096 <= length < 8192 */ ++ putbits24(obuf, 0xffe000|(len&0xfff), 24, &olen, &l); ++ } else { ++ /* This shouldn't happen; we return 0 what means "packet expands", ++ and send packet uncompressed. */ ++ if (state->debug) ++ printk(KERN_DEBUG "%s%d: wrong length of match value: %d\n", ++ __FUNCTION__, state->unit, len); ++ return 0; ++ } ++ } ++ ++ /* Add remaining octets to the output */ ++ while(isize - i > 0) { ++ if (ibuf[i] < 0x80) { /* literal byte < 0x80 */ ++ putbits8(obuf, (u32) ibuf[i++], 8, &olen, &l); ++ } else { /* literal byte >= 0x80 */ ++ putbits16(obuf, (u32) (0x100|(ibuf[i++]&0x7f)), 9, &olen, &l); ++ } ++ } ++ /* Reset unused bits of the last output octet */ ++ if ((l != 0) && (l != 8)) { ++ putbits8(obuf, 0, l, &olen, &l); ++ } ++ ++ return (int) olen; ++} ++ ++int ++mppe_compress(void *arg, unsigned char *ibuf, unsigned char *obuf, ++ int isize, int osize) ++{ ++ struct ppp_mppe_state *state = (struct ppp_mppe_state *) arg; ++ int proto, olen, complen, off; ++ unsigned char *wptr; ++ ++ /* Check that the protocol is in the range we handle. */ ++ proto = PPP_PROTOCOL(ibuf); ++ if (proto < 0x0021 || proto > 0x00fa) ++ return 0; ++ ++ wptr = obuf; ++ /* Copy over the PPP header */ ++ wptr[0] = PPP_ADDRESS(ibuf); ++ wptr[1] = PPP_CONTROL(ibuf); ++ wptr[2] = PPP_COMP >> 8; ++ wptr[3] = PPP_COMP; ++ wptr += PPP_HDRLEN + (MPPE_OVHD / 2); /* Leave two octets for MPPE/MPPC bits */ ++ ++ /* ++ * In ver. 0.99 protocol field was compressed. Deflate and BSD compress ++ * do PFC before actual compression, RCF2118 and RFC3078 are not precise ++ * on this topic so I decided to do PFC. Unfortunately this change caused ++ * incompatibility with older/other MPPE/MPPC modules. I have received ++ * a lot of complaints from unexperienced users so I have decided to revert ++ * to previous state, i.e. the protocol field is sent uncompressed now. ++ * Although this may be changed in the future. ++ * ++ * Receiving side (mppe_decompress()) still accepts packets with compressed ++ * and uncompressed protocol field so you shouldn't get "Unsupported protocol ++ * 0x2145 received" messages anymore. ++ */ ++ //off = (proto > 0xff) ? 2 : 3; /* PFC - skip first protocol byte if 0 */ ++ off = 2; ++ ++ ibuf += off; ++ ++ mppe_increase_ccount(state); ++ ++ if (state->nextflushed) { ++ state->bits |= MPPE_BIT_FLUSHED; ++ state->nextflushed = 0; ++ if (state->mppe && !state->stateless) { ++ /* ++ * If this is the flag packet, the key has been already changed in ++ * mppe_increase_ccount() so we dont't do it once again. ++ */ ++ if ((state->ccount & 0xff) != 0xff) { ++ arc4_setkey(state, state->session_key, state->keylen); ++ } ++ } ++ if (state->mppc) { /* reset history */ ++ state->bits |= MPPE_BIT_RESET; ++ state->histptr = MPPE_HIST_LEN; ++ memset(state->hist + MPPE_HIST_LEN, 0, MPPE_HIST_LEN*sizeof(u8)); ++ } ++ } ++ ++ if (state->mppc && !state->mppe) { /* Do only compression */ ++ complen = mppc_compress(state, ibuf, wptr, isize - off, ++ osize - PPP_HDRLEN - (MPPE_OVHD / 2)); ++ /* ++ * TODO: Implement an heuristics to handle packet expansion in a smart ++ * way. Now, when a packet expands, we send it as uncompressed and ++ * when next packet is sent we have to reset compressor's history. ++ * Maybe it would be better to send such packet as compressed in order ++ * to keep history's continuity. ++ */ ++ if ((complen > isize) || (complen > osize - PPP_HDRLEN) || ++ (complen == 0)) { ++ /* packet expands */ ++ state->nextflushed = 1; ++ memcpy(wptr, ibuf, isize - off); ++ olen = isize - (off - 2) + MPPE_OVHD; ++ (state->stats).inc_bytes += olen; ++ (state->stats).inc_packets++; ++ } else { ++ state->bits |= MPPE_BIT_COMP; ++ olen = complen + PPP_HDRLEN + (MPPE_OVHD / 2); ++ (state->stats).comp_bytes += olen; ++ (state->stats).comp_packets++; ++ } ++ } else { /* Do encryption with or without compression */ ++ state->bits |= MPPE_BIT_ENCRYPTED; ++ if (!state->mppc && state->mppe) { /* Do only encryption */ ++ /* read from ibuf, write to wptr, adjust for PPP_HDRLEN */ ++ arc4_encrypt(state, ibuf, isize - off, wptr); ++ olen = isize - (off - 2) + MPPE_OVHD; ++ (state->stats).inc_bytes += olen; ++ (state->stats).inc_packets++; ++ } else { /* Do compression and then encryption - RFC3078 */ ++ complen = mppc_compress(state, ibuf, wptr, isize - off, ++ osize - PPP_HDRLEN - (MPPE_OVHD / 2)); ++ /* ++ * TODO: Implement an heuristics to handle packet expansion in a smart ++ * way. Now, when a packet expands, we send it as uncompressed and ++ * when next packet is sent we have to reset compressor's history. ++ * Maybe it would be good to send such packet as compressed in order ++ * to keep history's continuity. ++ */ ++ if ((complen > isize) || (complen > osize - PPP_HDRLEN) || ++ (complen == 0)) { ++ /* packet expands */ ++ state->nextflushed = 1; ++ arc4_encrypt(state, ibuf, isize - off, wptr); ++ olen = isize - (off - 2) + MPPE_OVHD; ++ (state->stats).inc_bytes += olen; ++ (state->stats).inc_packets++; ++ } else { ++ state->bits |= MPPE_BIT_COMP; ++ /* Hack warning !!! RC4 implementation which we use does ++ encryption "in place" - it means that input and output ++ buffers can be *the same* memory area. Therefore we don't ++ need to use a temporary buffer. But be careful - other ++ implementations don't have to be so nice. ++ I used to use ibuf as temporary buffer here, but it led ++ packet sniffers into error. Thanks to Wilfried Weissmann ++ for pointing that. */ ++ arc4_encrypt(state, wptr, complen, wptr); ++ olen = complen + PPP_HDRLEN + (MPPE_OVHD / 2); ++ (state->stats).comp_bytes += olen; ++ (state->stats).comp_packets++; ++ } ++ } ++ } ++ ++ /* write status bits and coherency counter into the output buffer */ ++ wptr = obuf + PPP_HDRLEN; ++ wptr[0] = MPPE_CTRLHI(state); ++ wptr[1] = MPPE_CTRLLO(state); ++ ++ state->bits = 0; ++ ++ (state->stats).unc_bytes += isize; ++ (state->stats).unc_packets++; ++ ++ return olen; ++} ++ ++/***************************/ ++/*** Decompression stuff ***/ ++/***************************/ ++static inline u32 getbits(const u8 *buf, const u32 n, u32 *i, u32 *l) ++{ ++ static const u32 m[] = {0x00, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f, 0xff}; ++ u32 res, ol; ++ ++ ol = *l; ++ if (*l >= n) { ++ *l = (*l) - n; ++ res = (buf[*i] & m[ol]) >> (*l); ++ if (*l == 0) { ++ *l = 8; ++ (*i)++; ++ } ++ } else { ++ *l = 8 - n + (*l); ++ res = (buf[(*i)++] & m[ol]) << 8; ++ res = (res | buf[*i]) >> (*l); ++ } ++ ++ return res; ++} ++ ++static inline u32 getbyte(const u8 *buf, const u32 i, const u32 l) ++{ ++ if (l == 8) { ++ return buf[i]; ++ } else { ++ return (((buf[i] << 8) | buf[i+1]) >> l) & 0xff; ++ } ++} ++ ++static inline void lamecopy(u8 *dst, u8 *src, u32 len) ++{ ++ while (len--) ++ *dst++ = *src++; ++} ++ ++static int ++mppc_decompress(struct ppp_mppe_state *state, unsigned char *ibuf, ++ unsigned char *obuf, int isize, int osize) ++{ ++ u32 olen, off, len, bits, val, sig, i, l; ++ u8 *history, *s; ++ ++ history = state->hist + state->histptr; ++ olen = len = i = 0; ++ l = 8; ++ bits = isize * 8; ++ while (bits >= 8) { ++ val = getbyte(ibuf, i++, l); ++ if (val < 0x80) { /* literal byte < 0x80 */ ++ if (state->histptr < 2*MPPE_HIST_LEN) { ++ /* copy uncompressed byte to the history */ ++ (state->hist)[(state->histptr)++] = (u8) val; ++ } else { ++ /* buffer overflow; drop packet */ ++ if (state->debug) ++ printk(KERN_ERR "%s%d: trying to write outside history " ++ "buffer\n", __FUNCTION__, state->unit); ++ return DECOMP_ERROR; ++ } ++ olen++; ++ bits -= 8; ++ continue; ++ } ++ ++ sig = val & 0xc0; ++ if (sig == 0x80) { /* literal byte >= 0x80 */ ++ if (state->histptr < 2*MPPE_HIST_LEN) { ++ /* copy uncompressed byte to the history */ ++ (state->hist)[(state->histptr)++] = ++ (u8) (0x80|((val&0x3f)<<1)|getbits(ibuf, 1 , &i ,&l)); ++ } else { ++ /* buffer overflow; drop packet */ ++ if (state->debug) ++ printk(KERN_ERR "%s%d: trying to write outside history " ++ "buffer\n", __FUNCTION__, state->unit); ++ return DECOMP_ERROR; ++ } ++ olen++; ++ bits -= 9; ++ continue; ++ } ++ ++ /* Not a literal byte so it must be an (offset,length) pair */ ++ /* decode offset */ ++ sig = val & 0xf0; ++ if (sig == 0xf0) { /* 10-bit offset; 0 <= offset < 64 */ ++ off = (((val&0x0f)<<2)|getbits(ibuf, 2 , &i ,&l)); ++ bits -= 10; ++ } else { ++ if (sig == 0xe0) { /* 12-bit offset; 64 <= offset < 320 */ ++ off = ((((val&0x0f)<<4)|getbits(ibuf, 4 , &i ,&l))+64); ++ bits -= 12; ++ } else { ++ if ((sig&0xe0) == 0xc0) {/* 16-bit offset; 320 <= offset < 8192 */ ++ off = ((((val&0x1f)<<8)|getbyte(ibuf, i++, l))+320); ++ bits -= 16; ++ if (off > MPPE_HIST_LEN - 1) { ++ if (state->debug) ++ printk(KERN_DEBUG "%s%d: too big offset value: %d\n", ++ __FUNCTION__, state->unit, off); ++ return DECOMP_ERROR; ++ } ++ } else { /* this shouldn't happen */ ++ if (state->debug) ++ printk(KERN_DEBUG "%s%d: cannot decode offset value\n", ++ __FUNCTION__, state->unit); ++ return DECOMP_ERROR; ++ } ++ } ++ } ++ /* decode length of match */ ++ val = getbyte(ibuf, i, l); ++ if ((val & 0x80) == 0x00) { /* len = 3 */ ++ len = 3; ++ bits--; ++ getbits(ibuf, 1 , &i ,&l); ++ } else if ((val & 0xc0) == 0x80) { /* 4 <= len < 8 */ ++ len = 0x04 | ((val>>4) & 0x03); ++ bits -= 4; ++ getbits(ibuf, 4 , &i ,&l); ++ } else if ((val & 0xe0) == 0xc0) { /* 8 <= len < 16 */ ++ len = 0x08 | ((val>>2) & 0x07); ++ bits -= 6; ++ getbits(ibuf, 6 , &i ,&l); ++ } else if ((val & 0xf0) == 0xe0) { /* 16 <= len < 32 */ ++ len = 0x10 | (val & 0x0f); ++ bits -= 8; ++ i++; ++ } else { ++ bits -= 8; ++ val = (val << 8) | getbyte(ibuf, ++i, l); ++ if ((val & 0xf800) == 0xf000) { /* 32 <= len < 64 */ ++ len = 0x0020 | ((val >> 6) & 0x001f); ++ bits -= 2; ++ getbits(ibuf, 2 , &i ,&l); ++ } else if ((val & 0xfc00) == 0xf800) { /* 64 <= len < 128 */ ++ len = 0x0040 | ((val >> 4) & 0x003f); ++ bits -= 4; ++ getbits(ibuf, 4 , &i ,&l); ++ } else if ((val & 0xfe00) == 0xfc00) { /* 128 <= len < 256 */ ++ len = 0x0080 | ((val >> 2) & 0x007f); ++ bits -= 6; ++ getbits(ibuf, 6 , &i ,&l); ++ } else if ((val & 0xff00) == 0xfe00) { /* 256 <= len < 512 */ ++ len = 0x0100 | (val & 0x00ff); ++ bits -= 8; ++ i++; ++ } else { ++ bits -= 8; ++ val = (val << 8) | getbyte(ibuf, ++i, l); ++ if ((val & 0xff8000) == 0xff0000) { /* 512 <= len < 1024 */ ++ len = 0x000200 | ((val >> 6) & 0x0001ff); ++ bits -= 2; ++ getbits(ibuf, 2 , &i ,&l); ++ } else if ((val & 0xffc000) == 0xff8000) {/* 1024 <= len < 2048 */ ++ len = 0x000400 | ((val >> 4) & 0x0003ff); ++ bits -= 4; ++ getbits(ibuf, 4 , &i ,&l); ++ } else if ((val & 0xffe000) == 0xffc000) {/* 2048 <= len < 4096 */ ++ len = 0x000800 | ((val >> 2) & 0x0007ff); ++ bits -= 6; ++ getbits(ibuf, 6 , &i ,&l); ++ } else if ((val & 0xfff000) == 0xffe000) {/* 4096 <= len < 8192 */ ++ len = 0x001000 | (val & 0x000fff); ++ bits -= 8; ++ i++; ++ } else { /* this shouldn't happen */ ++ if (state->debug) ++ printk(KERN_DEBUG "%s%d: wrong length code: 0x%X\n", ++ __FUNCTION__, state->unit, val); ++ return DECOMP_ERROR; ++ } ++ } ++ } ++ s = state->hist + state->histptr; ++ state->histptr += len; ++ olen += len; ++ if (state->histptr < 2*MPPE_HIST_LEN) { ++ /* copy uncompressed bytes to the history */ ++ ++ /* In some cases len may be greater than off. It means that memory ++ * areas pointed by s and s-off overlap. I had used memmove() here ++ * because I thought that it acts as libc's version. Unfortunately, ++ * I was wrong. :-) I got strange errors sometimes. Wilfried suggested ++ * using of byte by byte copying here and strange errors disappeared. ++ */ ++ lamecopy(s, s - off, len); ++ } else { ++ /* buffer overflow; drop packet */ ++ if (state->debug) ++ printk(KERN_ERR "%s%d: trying to write outside history " ++ "buffer\n", __FUNCTION__, state->unit); ++ return DECOMP_ERROR; ++ } ++ } ++ ++ /* Do PFC decompression */ ++ len = olen; ++ if ((history[0] & 0x01) != 0) { ++ obuf[0] = 0; ++ obuf++; ++ len++; ++ } ++ ++ if (len <= osize) { ++ /* copy uncompressed packet to the output buffer */ ++ memcpy(obuf, history, olen); ++ } else { ++ /* buffer overflow; drop packet */ ++ if (state->debug) ++ printk(KERN_ERR "%s%d: too big uncompressed packet: %d\n", ++ __FUNCTION__, state->unit, len + (PPP_HDRLEN / 2)); ++ return DECOMP_ERROR; ++ } ++ ++ return (int) len; ++} ++ ++int ++mppe_decompress(void *arg, unsigned char *ibuf, int isize, ++ unsigned char *obuf, int osize) ++{ ++ struct ppp_mppe_state *state = (struct ppp_mppe_state *)arg; ++ int seq, bits, uncomplen; ++ ++ if (isize <= PPP_HDRLEN + MPPE_OVHD) { ++ if (state->debug) { ++ printk(KERN_DEBUG "%s%d: short packet (len=%d)\n", __FUNCTION__, ++ state->unit, isize); ++ } ++ return DECOMP_ERROR; ++ } ++ ++ /* Get coherency counter and control bits from input buffer */ ++ seq = MPPE_CCOUNT(ibuf); ++ bits = MPPE_BITS(ibuf); ++ ++ if (state->stateless) { ++ /* RFC 3078, sec 8.1. */ ++ mppe_increase_ccount(state); ++ if ((seq != state->ccount) && state->debug) ++ printk(KERN_DEBUG "%s%d: bad sequence number: %d, expected: %d\n", ++ __FUNCTION__, state->unit, seq, state->ccount); ++ while (seq != state->ccount) ++ mppe_increase_ccount(state); ++ } else { ++ /* RFC 3078, sec 8.2. */ ++ if (state->flushexpected) { /* discard state */ ++ if ((bits & MPPE_BIT_FLUSHED)) { /* we received expected FLUSH bit */ ++ while (seq != state->ccount) ++ mppe_increase_ccount(state); ++ state->flushexpected = 0; ++ } else /* drop packet*/ ++ return DECOMP_ERROR; ++ } else { /* normal state */ ++ mppe_increase_ccount(state); ++ if (seq != state->ccount) { ++ /* Packet loss detected, enter the discard state. */ ++ if (state->debug) ++ printk(KERN_DEBUG "%s%d: bad sequence number: %d, expected: %d\n", ++ __FUNCTION__, state->unit, seq, state->ccount); ++ state->flushexpected = 1; ++ return DECOMP_ERROR; ++ } ++ } ++ if (state->mppe && (bits & MPPE_BIT_FLUSHED)) { ++ arc4_setkey(state, state->session_key, state->keylen); ++ } ++ } ++ ++ if (state->mppc && (bits & (MPPE_BIT_FLUSHED | MPPE_BIT_RESET))) { ++ state->histptr = MPPE_HIST_LEN; ++ if ((bits & MPPE_BIT_FLUSHED)) { ++ memset(state->hist + MPPE_HIST_LEN, 0, MPPE_HIST_LEN*sizeof(u8)); ++ } else ++ if ((bits & MPPE_BIT_RESET)) { ++ memcpy(state->hist, state->hist + MPPE_HIST_LEN, MPPE_HIST_LEN); ++ } ++ } ++ ++ /* Fill in the first part of the PPP header. The protocol field ++ comes from the decompressed data. */ ++ obuf[0] = PPP_ADDRESS(ibuf); ++ obuf[1] = PPP_CONTROL(ibuf); ++ obuf += PPP_HDRLEN / 2; ++ ++ if (state->mppe) { /* process encrypted packet */ ++ if ((bits & MPPE_BIT_ENCRYPTED)) { ++ /* OK, packet encrypted, so decrypt it */ ++ if (state->mppc && (bits & MPPE_BIT_COMP)) { ++ /* Hack warning !!! RC4 implementation which we use does ++ decryption "in place" - it means that input and output ++ buffers can be *the same* memory area. Therefore we don't ++ need to use a temporary buffer. But be careful - other ++ implementations don't have to be so nice. */ ++ arc4_decrypt(state, ibuf + PPP_HDRLEN + (MPPE_OVHD / 2), isize - ++ PPP_HDRLEN - (MPPE_OVHD / 2), ibuf + PPP_HDRLEN + ++ (MPPE_OVHD / 2)); ++ uncomplen = mppc_decompress(state, ibuf + PPP_HDRLEN + ++ (MPPE_OVHD / 2), obuf, isize - ++ PPP_HDRLEN - (MPPE_OVHD / 2), ++ osize - (PPP_HDRLEN / 2)); ++ if (uncomplen == DECOMP_ERROR) { ++ state->flushexpected = 1; ++ return DECOMP_ERROR; ++ } ++ uncomplen += PPP_HDRLEN / 2; ++ (state->stats).comp_bytes += isize; ++ (state->stats).comp_packets++; ++ } else { ++ uncomplen = isize - MPPE_OVHD; ++ /* Decrypt the first byte in order to check if it is ++ compressed or uncompressed protocol field */ ++ arc4_decrypt(state, ibuf + PPP_HDRLEN + (MPPE_OVHD / 2), 1, obuf); ++ /* Do PFC decompression */ ++ if ((obuf[0] & 0x01) != 0) { ++ obuf[1] = obuf[0]; ++ obuf[0] = 0; ++ obuf++; ++ uncomplen++; ++ } ++ /* And finally, decrypt the rest of the frame. */ ++ arc4_decrypt(state, ibuf + PPP_HDRLEN + (MPPE_OVHD / 2) + 1, ++ isize - PPP_HDRLEN - (MPPE_OVHD / 2) - 1, obuf + 1); ++ (state->stats).inc_bytes += isize; ++ (state->stats).inc_packets++; ++ } ++ } else { /* this shouldn't happen */ ++ if (state->debug) ++ printk(KERN_ERR "%s%d: encryption negotiated but not an " ++ "encrypted packet received\n", __FUNCTION__, state->unit); ++ mppe_change_key(state, 0); ++ state->flushexpected = 1; ++ return DECOMP_ERROR; ++ } ++ } else { ++ if (state->mppc) { /* no MPPE, only MPPC */ ++ if ((bits & MPPE_BIT_COMP)) { ++ uncomplen = mppc_decompress(state, ibuf + PPP_HDRLEN + ++ (MPPE_OVHD / 2), obuf, isize - ++ PPP_HDRLEN - (MPPE_OVHD / 2), ++ osize - (PPP_HDRLEN / 2)); ++ if (uncomplen == DECOMP_ERROR) { ++ state->flushexpected = 1; ++ return DECOMP_ERROR; ++ } ++ uncomplen += PPP_HDRLEN / 2; ++ (state->stats).comp_bytes += isize; ++ (state->stats).comp_packets++; ++ } else { ++ memcpy(obuf, ibuf + PPP_HDRLEN + (MPPE_OVHD / 2), isize - ++ PPP_HDRLEN - (MPPE_OVHD / 2)); ++ uncomplen = isize - MPPE_OVHD; ++ (state->stats).inc_bytes += isize; ++ (state->stats).inc_packets++; ++ } ++ } else { /* this shouldn't happen */ ++ if (state->debug) ++ printk(KERN_ERR "%s%d: error - not an MPPC or MPPE frame " ++ "received\n", __FUNCTION__, state->unit); ++ state->flushexpected = 1; ++ return DECOMP_ERROR; ++ } ++ } ++ ++ (state->stats).unc_bytes += uncomplen; ++ (state->stats).unc_packets++; ++ ++ return uncomplen; ++} ++ ++ ++/************************************************************ ++ * Module interface table ++ ************************************************************/ ++ ++/* These are in ppp_generic.c */ ++extern int ppp_register_compressor (struct compressor *cp); ++extern void ppp_unregister_compressor (struct compressor *cp); ++ ++/* ++ * Functions exported to ppp_generic.c. ++ * ++ * In case of MPPC/MPPE there is no need to process incompressible data ++ * because such a data is sent in MPPC/MPPE frame. Therefore the (*incomp) ++ * callback function isn't needed. ++ */ ++struct compressor ppp_mppe = { ++ CI_MPPE, /* compress_proto */ ++ mppe_comp_alloc, /* comp_alloc */ ++ mppe_comp_free, /* comp_free */ ++ mppe_comp_init, /* comp_init */ ++ mppe_comp_reset, /* comp_reset */ ++ mppe_compress, /* compress */ ++ mppe_stats, /* comp_stat */ ++ mppe_decomp_alloc, /* decomp_alloc */ ++ mppe_comp_free, /* decomp_free */ ++ mppe_decomp_init, /* decomp_init */ ++ mppe_decomp_reset, /* decomp_reset */ ++ mppe_decompress, /* decompress */ ++ NULL, /* incomp */ ++ mppe_stats, /* decomp_stat */ ++}; ++ ++/************************************************************ ++ * Module support routines ++ ************************************************************/ ++ ++int __init mppe_module_init(void) ++{ ++ int answer = 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) ++{ ++ ppp_unregister_compressor(&ppp_mppe); ++ printk(KERN_INFO "MPPE/MPPC encryption/compression module unregistered\n"); ++} ++ ++module_init(mppe_module_init); ++module_exit(mppe_module_cleanup); ++ ++MODULE_AUTHOR("Jan Dubiec <jdx@slackware.pl>"); ++MODULE_DESCRIPTION("MPPE/MPPC encryption/compression module for Linux"); ++MODULE_LICENSE("Dual BSD/GPL"); +diff -ruN linux.orig/include/linux/ppp-comp.h linux/include/linux/ppp-comp.h +--- linux.orig/include/linux/ppp-comp.h 1999-08-06 19:44:11.000000000 +0200 ++++ linux/include/linux/ppp-comp.h 2004-08-08 12:17:43.000000000 +0200 +@@ -1,34 +1,42 @@ + /* + * ppp-comp.h - Definitions for doing PPP packet compression. + * +- * Copyright (c) 1994 The Australian National University. +- * All rights reserved. ++ * Copyright (c) 1984 Paul Mackerras. All rights reserved. + * +- * 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 Australian National University +- * makes no representations about the suitability of this software for +- * any purpose. +- * +- * IN NO EVENT SHALL THE AUSTRALIAN NATIONAL UNIVERSITY BE LIABLE TO ANY +- * PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES +- * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF +- * THE AUSTRALIAN NATIONAL UNIVERSITY HAVE BEEN ADVISED OF THE POSSIBILITY +- * OF SUCH DAMAGE. +- * +- * THE AUSTRALIAN NATIONAL UNIVERSITY SPECIFICALLY DISCLAIMS ANY WARRANTIES, +- * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY +- * AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS +- * ON AN "AS IS" BASIS, AND THE AUSTRALIAN NATIONAL UNIVERSITY HAS NO +- * OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, +- * OR MODIFICATIONS. ++ * Redistribution and use in source and binary forms, with or without ++ * modification, are permitted provided that the following conditions ++ * are met: + * +- * $Id: ppp-comp.h,v 1.6 1997/11/27 06:04:44 paulus Exp $ ++ * 1. Redistributions of source code must retain the above copyright ++ * notice, this list of conditions and the following disclaimer. ++ * ++ * 2. Redistributions in binary form must reproduce the above copyright ++ * notice, this list of conditions and the following disclaimer in ++ * the documentation and/or other materials provided with the ++ * distribution. ++ * ++ * 3. The name(s) of the authors of this software must not be used to ++ * endorse or promote products derived from this software without ++ * prior written permission. ++ * ++ * 4. Redistributions of any form whatsoever must retain the following ++ * acknowledgment: ++ * "This product includes software developed by Paul Mackerras ++ * <paulus@samba.org>". ++ * ++ * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO ++ * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY ++ * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY ++ * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES ++ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN ++ * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING ++ * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. ++ * ++ * $Id: ppp-comp.h,v 1.10 2002/12/06 09:49:15 paulus Exp $ + */ + + /* +- * ==FILEVERSION 980319== ++ * ==FILEVERSION 20040509== + * + * NOTE TO MAINTAINERS: + * If you modify this file at all, please set the above date. +@@ -78,7 +86,7 @@ + + /* Compress a packet */ + int (*compress) (void *state, unsigned char *rptr, +- unsigned char *obuf, int isize, int osize); ++ unsigned char *obuf, int isize, int osize); + + /* Return compression statistics */ + void (*comp_stat) (void *state, struct compstat *stats); +@@ -99,7 +107,7 @@ + + /* Decompress a packet. */ + int (*decompress) (void *state, unsigned char *ibuf, int isize, +- unsigned char *obuf, int osize); ++ unsigned char *obuf, int osize); + + /* Update state for an incompressible packet received */ + void (*incomp) (void *state, unsigned char *ibuf, int icnt); +@@ -187,6 +195,42 @@ + #define DEFLATE_CHK_SEQUENCE 0 + + /* ++ * Definitions for MPPE/MPPC. ++ */ ++ ++#define CI_MPPE 18 /* config option for MPPE */ ++#define CILEN_MPPE 6 /* length of config option */ ++ ++#define MPPE_OVHD 4 /* MPPE overhead */ ++#define MPPE_MAX_KEY_LEN 16 /* largest key length (128-bit) */ ++ ++#define MPPE_STATELESS 0x01 /* configuration bit H */ ++#define MPPE_40BIT 0x20 /* configuration bit L */ ++#define MPPE_56BIT 0x80 /* configuration bit M */ ++#define MPPE_128BIT 0x40 /* configuration bit S */ ++#define MPPE_MPPC 0x01 /* configuration bit C */ ++ ++/* ++ * Definitions for Stac LZS. ++ */ ++ ++#define CI_LZS 17 /* config option for Stac LZS */ ++#define CILEN_LZS 5 /* length of config option */ ++ ++#define LZS_OVHD 4 /* max. LZS overhead */ ++#define LZS_HIST_LEN 2048 /* LZS history size */ ++#define LZS_MAX_CCOUNT 0x0FFF /* max. coherency counter value */ ++ ++#define LZS_MODE_NONE 0 ++#define LZS_MODE_LCB 1 ++#define LZS_MODE_CRC 2 ++#define LZS_MODE_SEQ 3 ++#define LZS_MODE_EXT 4 ++ ++#define LZS_EXT_BIT_FLUSHED 0x80 /* bit A */ ++#define LZS_EXT_BIT_COMP 0x20 /* bit C */ ++ ++/* + * Definitions for other, as yet unsupported, compression methods. + */ + |