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688 lines
19 KiB
688 lines
19 KiB
/* |
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* ppp_mppe.c - interface MPPE to the PPP code. |
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* This version is for use with Linux kernel 2.6.14+ |
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* |
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* By Frank Cusack <[email protected]>. |
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* Copyright (c) 2002,2003,2004 Google, Inc. |
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* All rights reserved. |
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* |
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* License: |
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* Permission to use, copy, modify, and distribute this software and its |
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* documentation is hereby granted, provided that the above copyright |
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* notice appears in all copies. This software is provided without any |
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* warranty, express or implied. |
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* |
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* ALTERNATIVELY, provided that this notice is retained in full, this product |
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* may be distributed under the terms of the GNU General Public License (GPL), |
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* in which case the provisions of the GPL apply INSTEAD OF those given above. |
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* |
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* This program is free software; you can redistribute it and/or modify |
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* it under the terms of the GNU General Public License as published by |
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* the Free Software Foundation; either version 2 of the License, or |
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* (at your option) any later version. |
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* |
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* This program is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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* GNU General Public License for more details. |
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* |
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* You should have received a copy of the GNU General Public License |
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* along with this program; if not, see <http://www.gnu.org/licenses/>. |
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* |
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* |
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* Changelog: |
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* 08/12/05 - Matt Domsch <[email protected]> |
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* Only need extra skb padding on transmit, not receive. |
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* 06/18/04 - Matt Domsch <[email protected]>, Oleg Makarenko <[email protected]> |
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* Use Linux kernel 2.6 arc4 and sha1 routines rather than |
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* providing our own. |
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* 2/15/04 - TS: added #include <version.h> and testing for Kernel |
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* version before using |
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* MOD_DEC_USAGE_COUNT/MOD_INC_USAGE_COUNT which are |
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* deprecated in 2.6 |
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*/ |
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|
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#include <crypto/arc4.h> |
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#include <crypto/hash.h> |
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#include <linux/err.h> |
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#include <linux/fips.h> |
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#include <linux/module.h> |
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#include <linux/kernel.h> |
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#include <linux/init.h> |
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#include <linux/types.h> |
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#include <linux/slab.h> |
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#include <linux/string.h> |
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#include <linux/mm.h> |
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#include <linux/ppp_defs.h> |
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#include <linux/ppp-comp.h> |
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#include <linux/scatterlist.h> |
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#include <asm/unaligned.h> |
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|
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#include "ppp_mppe.h" |
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|
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MODULE_AUTHOR("Frank Cusack <[email protected]>"); |
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MODULE_DESCRIPTION("Point-to-Point Protocol Microsoft Point-to-Point Encryption support"); |
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MODULE_LICENSE("Dual BSD/GPL"); |
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MODULE_ALIAS("ppp-compress-" __stringify(CI_MPPE)); |
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MODULE_VERSION("1.0.2"); |
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|
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#define SHA1_PAD_SIZE 40 |
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|
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/* |
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* kernel crypto API needs its arguments to be in kmalloc'd memory, not in the module |
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* static data area. That means sha_pad needs to be kmalloc'd. |
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*/ |
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|
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struct sha_pad { |
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unsigned char sha_pad1[SHA1_PAD_SIZE]; |
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unsigned char sha_pad2[SHA1_PAD_SIZE]; |
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}; |
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static struct sha_pad *sha_pad; |
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|
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static inline void sha_pad_init(struct sha_pad *shapad) |
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{ |
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memset(shapad->sha_pad1, 0x00, sizeof(shapad->sha_pad1)); |
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memset(shapad->sha_pad2, 0xF2, sizeof(shapad->sha_pad2)); |
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} |
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|
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/* |
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* State for an MPPE (de)compressor. |
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*/ |
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struct ppp_mppe_state { |
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struct arc4_ctx arc4; |
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struct shash_desc *sha1; |
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unsigned char *sha1_digest; |
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unsigned char master_key[MPPE_MAX_KEY_LEN]; |
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unsigned char session_key[MPPE_MAX_KEY_LEN]; |
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unsigned keylen; /* key length in bytes */ |
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/* NB: 128-bit == 16, 40-bit == 8! */ |
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/* If we want to support 56-bit, */ |
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/* the unit has to change to bits */ |
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unsigned char bits; /* MPPE control bits */ |
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unsigned ccount; /* 12-bit coherency count (seqno) */ |
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unsigned stateful; /* stateful mode flag */ |
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int discard; /* stateful mode packet loss flag */ |
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int sanity_errors; /* take down LCP if too many */ |
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int unit; |
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int debug; |
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struct compstat stats; |
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}; |
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|
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/* struct ppp_mppe_state.bits definitions */ |
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#define MPPE_BIT_A 0x80 /* Encryption table were (re)inititalized */ |
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#define MPPE_BIT_B 0x40 /* MPPC only (not implemented) */ |
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#define MPPE_BIT_C 0x20 /* MPPC only (not implemented) */ |
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#define MPPE_BIT_D 0x10 /* This is an encrypted frame */ |
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|
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#define MPPE_BIT_FLUSHED MPPE_BIT_A |
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#define MPPE_BIT_ENCRYPTED MPPE_BIT_D |
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|
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#define MPPE_BITS(p) ((p)[4] & 0xf0) |
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#define MPPE_CCOUNT(p) ((((p)[4] & 0x0f) << 8) + (p)[5]) |
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#define MPPE_CCOUNT_SPACE 0x1000 /* The size of the ccount space */ |
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|
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#define MPPE_OVHD 2 /* MPPE overhead/packet */ |
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#define SANITY_MAX 1600 /* Max bogon factor we will tolerate */ |
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|
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/* |
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* Key Derivation, from RFC 3078, RFC 3079. |
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* Equivalent to Get_Key() for MS-CHAP as described in RFC 3079. |
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*/ |
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static void get_new_key_from_sha(struct ppp_mppe_state * state) |
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{ |
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crypto_shash_init(state->sha1); |
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crypto_shash_update(state->sha1, state->master_key, |
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state->keylen); |
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crypto_shash_update(state->sha1, sha_pad->sha_pad1, |
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sizeof(sha_pad->sha_pad1)); |
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crypto_shash_update(state->sha1, state->session_key, |
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state->keylen); |
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crypto_shash_update(state->sha1, sha_pad->sha_pad2, |
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sizeof(sha_pad->sha_pad2)); |
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crypto_shash_final(state->sha1, state->sha1_digest); |
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} |
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|
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/* |
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* Perform the MPPE rekey algorithm, from RFC 3078, sec. 7.3. |
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* Well, not what's written there, but rather what they meant. |
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*/ |
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static void mppe_rekey(struct ppp_mppe_state * state, int initial_key) |
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{ |
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get_new_key_from_sha(state); |
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if (!initial_key) { |
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arc4_setkey(&state->arc4, state->sha1_digest, state->keylen); |
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arc4_crypt(&state->arc4, state->session_key, state->sha1_digest, |
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state->keylen); |
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} else { |
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memcpy(state->session_key, state->sha1_digest, state->keylen); |
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} |
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if (state->keylen == 8) { |
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/* See RFC 3078 */ |
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state->session_key[0] = 0xd1; |
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state->session_key[1] = 0x26; |
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state->session_key[2] = 0x9e; |
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} |
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arc4_setkey(&state->arc4, state->session_key, state->keylen); |
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} |
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/* |
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* Allocate space for a (de)compressor. |
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*/ |
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static void *mppe_alloc(unsigned char *options, int optlen) |
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{ |
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struct ppp_mppe_state *state; |
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struct crypto_shash *shash; |
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unsigned int digestsize; |
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if (optlen != CILEN_MPPE + sizeof(state->master_key) || |
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options[0] != CI_MPPE || options[1] != CILEN_MPPE || |
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fips_enabled) |
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goto out; |
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state = kzalloc(sizeof(*state), GFP_KERNEL); |
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if (state == NULL) |
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goto out; |
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shash = crypto_alloc_shash("sha1", 0, 0); |
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if (IS_ERR(shash)) |
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goto out_free; |
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state->sha1 = kmalloc(sizeof(*state->sha1) + |
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crypto_shash_descsize(shash), |
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GFP_KERNEL); |
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if (!state->sha1) { |
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crypto_free_shash(shash); |
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goto out_free; |
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} |
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state->sha1->tfm = shash; |
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|
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digestsize = crypto_shash_digestsize(shash); |
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if (digestsize < MPPE_MAX_KEY_LEN) |
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goto out_free; |
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state->sha1_digest = kmalloc(digestsize, GFP_KERNEL); |
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if (!state->sha1_digest) |
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goto out_free; |
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|
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/* Save keys. */ |
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memcpy(state->master_key, &options[CILEN_MPPE], |
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sizeof(state->master_key)); |
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memcpy(state->session_key, state->master_key, |
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sizeof(state->master_key)); |
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|
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/* |
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* We defer initial key generation until mppe_init(), as mppe_alloc() |
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* is called frequently during negotiation. |
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*/ |
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return (void *)state; |
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out_free: |
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kfree(state->sha1_digest); |
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if (state->sha1) { |
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crypto_free_shash(state->sha1->tfm); |
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kfree_sensitive(state->sha1); |
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} |
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kfree(state); |
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out: |
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return NULL; |
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} |
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/* |
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* Deallocate space for a (de)compressor. |
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*/ |
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static void mppe_free(void *arg) |
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{ |
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struct ppp_mppe_state *state = (struct ppp_mppe_state *) arg; |
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if (state) { |
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kfree(state->sha1_digest); |
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crypto_free_shash(state->sha1->tfm); |
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kfree_sensitive(state->sha1); |
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kfree_sensitive(state); |
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} |
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} |
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/* |
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* Initialize (de)compressor state. |
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*/ |
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static int |
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mppe_init(void *arg, unsigned char *options, int optlen, int unit, int debug, |
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const char *debugstr) |
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{ |
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struct ppp_mppe_state *state = (struct ppp_mppe_state *) arg; |
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unsigned char mppe_opts; |
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|
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if (optlen != CILEN_MPPE || |
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options[0] != CI_MPPE || options[1] != CILEN_MPPE) |
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return 0; |
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MPPE_CI_TO_OPTS(&options[2], mppe_opts); |
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if (mppe_opts & MPPE_OPT_128) |
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state->keylen = 16; |
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else if (mppe_opts & MPPE_OPT_40) |
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state->keylen = 8; |
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else { |
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printk(KERN_WARNING "%s[%d]: unknown key length\n", debugstr, |
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unit); |
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return 0; |
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} |
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if (mppe_opts & MPPE_OPT_STATEFUL) |
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state->stateful = 1; |
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|
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/* Generate the initial session key. */ |
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mppe_rekey(state, 1); |
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if (debug) { |
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printk(KERN_DEBUG "%s[%d]: initialized with %d-bit %s mode\n", |
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debugstr, unit, (state->keylen == 16) ? 128 : 40, |
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(state->stateful) ? "stateful" : "stateless"); |
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printk(KERN_DEBUG |
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"%s[%d]: keys: master: %*phN initial session: %*phN\n", |
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debugstr, unit, |
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(int)sizeof(state->master_key), state->master_key, |
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(int)sizeof(state->session_key), state->session_key); |
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} |
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/* |
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* Initialize the coherency count. The initial value is not specified |
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* in RFC 3078, but we can make a reasonable assumption that it will |
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* start at 0. Setting it to the max here makes the comp/decomp code |
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* do the right thing (determined through experiment). |
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*/ |
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state->ccount = MPPE_CCOUNT_SPACE - 1; |
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|
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/* |
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* Note that even though we have initialized the key table, we don't |
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* set the FLUSHED bit. This is contrary to RFC 3078, sec. 3.1. |
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*/ |
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state->bits = MPPE_BIT_ENCRYPTED; |
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|
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state->unit = unit; |
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state->debug = debug; |
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|
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return 1; |
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} |
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|
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static int |
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mppe_comp_init(void *arg, unsigned char *options, int optlen, int unit, |
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int hdrlen, int debug) |
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{ |
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/* ARGSUSED */ |
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return mppe_init(arg, options, optlen, unit, debug, "mppe_comp_init"); |
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} |
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|
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/* |
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* We received a CCP Reset-Request (actually, we are sending a Reset-Ack), |
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* tell the compressor to rekey. Note that we MUST NOT rekey for |
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* every CCP Reset-Request; we only rekey on the next xmit packet. |
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* We might get multiple CCP Reset-Requests if our CCP Reset-Ack is lost. |
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* So, rekeying for every CCP Reset-Request is broken as the peer will not |
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* know how many times we've rekeyed. (If we rekey and THEN get another |
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* CCP Reset-Request, we must rekey again.) |
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*/ |
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static void mppe_comp_reset(void *arg) |
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{ |
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struct ppp_mppe_state *state = (struct ppp_mppe_state *) arg; |
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|
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state->bits |= MPPE_BIT_FLUSHED; |
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} |
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|
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/* |
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* Compress (encrypt) a packet. |
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* It's strange to call this a compressor, since the output is always |
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* MPPE_OVHD + 2 bytes larger than the input. |
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*/ |
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static int |
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mppe_compress(void *arg, unsigned char *ibuf, unsigned char *obuf, |
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int isize, int osize) |
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{ |
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struct ppp_mppe_state *state = (struct ppp_mppe_state *) arg; |
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int proto; |
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|
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/* |
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* Check that the protocol is in the range we handle. |
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*/ |
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proto = PPP_PROTOCOL(ibuf); |
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if (proto < 0x0021 || proto > 0x00fa) |
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return 0; |
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|
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/* Make sure we have enough room to generate an encrypted packet. */ |
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if (osize < isize + MPPE_OVHD + 2) { |
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/* Drop the packet if we should encrypt it, but can't. */ |
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printk(KERN_DEBUG "mppe_compress[%d]: osize too small! " |
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"(have: %d need: %d)\n", state->unit, |
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osize, osize + MPPE_OVHD + 2); |
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return -1; |
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} |
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|
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osize = isize + MPPE_OVHD + 2; |
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|
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/* |
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* Copy over the PPP header and set control bits. |
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*/ |
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obuf[0] = PPP_ADDRESS(ibuf); |
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obuf[1] = PPP_CONTROL(ibuf); |
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put_unaligned_be16(PPP_COMP, obuf + 2); |
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obuf += PPP_HDRLEN; |
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|
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state->ccount = (state->ccount + 1) % MPPE_CCOUNT_SPACE; |
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if (state->debug >= 7) |
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printk(KERN_DEBUG "mppe_compress[%d]: ccount %d\n", state->unit, |
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state->ccount); |
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put_unaligned_be16(state->ccount, obuf); |
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|
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if (!state->stateful || /* stateless mode */ |
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((state->ccount & 0xff) == 0xff) || /* "flag" packet */ |
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(state->bits & MPPE_BIT_FLUSHED)) { /* CCP Reset-Request */ |
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/* We must rekey */ |
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if (state->debug && state->stateful) |
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printk(KERN_DEBUG "mppe_compress[%d]: rekeying\n", |
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state->unit); |
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mppe_rekey(state, 0); |
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state->bits |= MPPE_BIT_FLUSHED; |
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} |
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obuf[0] |= state->bits; |
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state->bits &= ~MPPE_BIT_FLUSHED; /* reset for next xmit */ |
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|
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obuf += MPPE_OVHD; |
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ibuf += 2; /* skip to proto field */ |
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isize -= 2; |
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|
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arc4_crypt(&state->arc4, obuf, ibuf, isize); |
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|
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state->stats.unc_bytes += isize; |
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state->stats.unc_packets++; |
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state->stats.comp_bytes += osize; |
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state->stats.comp_packets++; |
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|
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return osize; |
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} |
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|
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/* |
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* Since every frame grows by MPPE_OVHD + 2 bytes, this is always going |
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* to look bad ... and the longer the link is up the worse it will get. |
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*/ |
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static void mppe_comp_stats(void *arg, struct compstat *stats) |
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{ |
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struct ppp_mppe_state *state = (struct ppp_mppe_state *) arg; |
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|
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*stats = state->stats; |
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} |
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|
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static int |
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mppe_decomp_init(void *arg, unsigned char *options, int optlen, int unit, |
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int hdrlen, int mru, int debug) |
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{ |
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/* ARGSUSED */ |
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return mppe_init(arg, options, optlen, unit, debug, "mppe_decomp_init"); |
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} |
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|
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/* |
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* We received a CCP Reset-Ack. Just ignore it. |
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*/ |
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static void mppe_decomp_reset(void *arg) |
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{ |
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/* ARGSUSED */ |
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return; |
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} |
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|
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/* |
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* Decompress (decrypt) an MPPE packet. |
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*/ |
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static int |
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mppe_decompress(void *arg, unsigned char *ibuf, int isize, unsigned char *obuf, |
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int osize) |
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{ |
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struct ppp_mppe_state *state = (struct ppp_mppe_state *) arg; |
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unsigned ccount; |
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int flushed = MPPE_BITS(ibuf) & MPPE_BIT_FLUSHED; |
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|
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if (isize <= PPP_HDRLEN + MPPE_OVHD) { |
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if (state->debug) |
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printk(KERN_DEBUG |
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"mppe_decompress[%d]: short pkt (%d)\n", |
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state->unit, isize); |
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return DECOMP_ERROR; |
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} |
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|
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/* |
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* Make sure we have enough room to decrypt the packet. |
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* Note that for our test we only subtract 1 byte whereas in |
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* mppe_compress() we added 2 bytes (+MPPE_OVHD); |
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* this is to account for possible PFC. |
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*/ |
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if (osize < isize - MPPE_OVHD - 1) { |
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printk(KERN_DEBUG "mppe_decompress[%d]: osize too small! " |
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"(have: %d need: %d)\n", state->unit, |
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osize, isize - MPPE_OVHD - 1); |
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return DECOMP_ERROR; |
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} |
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osize = isize - MPPE_OVHD - 2; /* assume no PFC */ |
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|
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ccount = MPPE_CCOUNT(ibuf); |
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if (state->debug >= 7) |
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printk(KERN_DEBUG "mppe_decompress[%d]: ccount %d\n", |
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state->unit, ccount); |
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|
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/* sanity checks -- terminate with extreme prejudice */ |
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if (!(MPPE_BITS(ibuf) & MPPE_BIT_ENCRYPTED)) { |
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printk(KERN_DEBUG |
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"mppe_decompress[%d]: ENCRYPTED bit not set!\n", |
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state->unit); |
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state->sanity_errors += 100; |
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goto sanity_error; |
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} |
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if (!state->stateful && !flushed) { |
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printk(KERN_DEBUG "mppe_decompress[%d]: FLUSHED bit not set in " |
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"stateless mode!\n", state->unit); |
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state->sanity_errors += 100; |
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goto sanity_error; |
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} |
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if (state->stateful && ((ccount & 0xff) == 0xff) && !flushed) { |
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printk(KERN_DEBUG "mppe_decompress[%d]: FLUSHED bit not set on " |
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"flag packet!\n", state->unit); |
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state->sanity_errors += 100; |
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goto sanity_error; |
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} |
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|
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/* |
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* Check the coherency count. |
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*/ |
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|
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if (!state->stateful) { |
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/* Discard late packet */ |
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if ((ccount - state->ccount) % MPPE_CCOUNT_SPACE |
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> MPPE_CCOUNT_SPACE / 2) { |
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state->sanity_errors++; |
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goto sanity_error; |
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} |
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|
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/* RFC 3078, sec 8.1. Rekey for every packet. */ |
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while (state->ccount != ccount) { |
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mppe_rekey(state, 0); |
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state->ccount = (state->ccount + 1) % MPPE_CCOUNT_SPACE; |
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} |
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} else { |
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/* RFC 3078, sec 8.2. */ |
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if (!state->discard) { |
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/* normal state */ |
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state->ccount = (state->ccount + 1) % MPPE_CCOUNT_SPACE; |
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if (ccount != state->ccount) { |
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/* |
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* (ccount > state->ccount) |
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* Packet loss detected, enter the discard state. |
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* Signal the peer to rekey (by sending a CCP Reset-Request). |
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*/ |
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state->discard = 1; |
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return DECOMP_ERROR; |
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} |
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} else { |
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/* discard state */ |
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if (!flushed) { |
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/* ccp.c will be silent (no additional CCP Reset-Requests). */ |
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return DECOMP_ERROR; |
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} else { |
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/* Rekey for every missed "flag" packet. */ |
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while ((ccount & ~0xff) != |
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(state->ccount & ~0xff)) { |
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mppe_rekey(state, 0); |
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state->ccount = |
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(state->ccount + |
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256) % MPPE_CCOUNT_SPACE; |
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} |
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|
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/* reset */ |
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state->discard = 0; |
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state->ccount = ccount; |
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/* |
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* Another problem with RFC 3078 here. It implies that the |
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* peer need not send a Reset-Ack packet. But RFC 1962 |
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* requires it. Hopefully, M$ does send a Reset-Ack; even |
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* 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. |
|
*/ |
|
arc4_crypt(&state->arc4, obuf, ibuf, 1); |
|
|
|
/* |
|
* 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. */ |
|
arc4_crypt(&state->arc4, obuf + 1, ibuf + 1, isize - 1); |
|
|
|
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; |
|
|
|
sanity_error: |
|
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; |
|
} |
|
|
|
/* |
|
* 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 (fips_enabled || !crypto_has_ahash("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);
|
|
|