]>
git.proxmox.com Git - mirror_ubuntu-zesty-kernel.git/blob - drivers/net/ppp_mppe.c
2 * ppp_mppe.c - interface MPPE to the PPP code.
3 * This version is for use with Linux kernel 2.6.14+
5 * By Frank Cusack <fcusack@fcusack.com>.
6 * Copyright (c) 2002,2003,2004 Google, Inc.
10 * Permission to use, copy, modify, and distribute this software and its
11 * documentation is hereby granted, provided that the above copyright
12 * notice appears in all copies. This software is provided without any
13 * warranty, express or implied.
15 * ALTERNATIVELY, provided that this notice is retained in full, this product
16 * may be distributed under the terms of the GNU General Public License (GPL),
17 * in which case the provisions of the GPL apply INSTEAD OF those given above.
19 * This program is free software; you can redistribute it and/or modify
20 * it under the terms of the GNU General Public License as published by
21 * the Free Software Foundation; either version 2 of the License, or
22 * (at your option) any later version.
24 * This program is distributed in the hope that it will be useful,
25 * but WITHOUT ANY WARRANTY; without even the implied warranty of
26 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
27 * GNU General Public License for more details.
29 * You should have received a copy of the GNU General Public License
30 * along with this program; if not, write to the Free Software
31 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
35 * 08/12/05 - Matt Domsch <Matt_Domsch@dell.com>
36 * Only need extra skb padding on transmit, not receive.
37 * 06/18/04 - Matt Domsch <Matt_Domsch@dell.com>, Oleg Makarenko <mole@quadra.ru>
38 * Use Linux kernel 2.6 arc4 and sha1 routines rather than
40 * 2/15/04 - TS: added #include <version.h> and testing for Kernel
41 * version before using
42 * MOD_DEC_USAGE_COUNT/MOD_INC_USAGE_COUNT which are
46 #include <linux/err.h>
47 #include <linux/module.h>
48 #include <linux/kernel.h>
49 #include <linux/version.h>
50 #include <linux/init.h>
51 #include <linux/types.h>
52 #include <linux/slab.h>
53 #include <linux/string.h>
54 #include <linux/crypto.h>
56 #include <linux/ppp_defs.h>
57 #include <linux/ppp-comp.h>
58 #include <linux/scatterlist.h>
62 MODULE_AUTHOR("Frank Cusack <fcusack@fcusack.com>");
63 MODULE_DESCRIPTION("Point-to-Point Protocol Microsoft Point-to-Point Encryption support");
64 MODULE_LICENSE("Dual BSD/GPL");
65 MODULE_ALIAS("ppp-compress-" __stringify(CI_MPPE
));
66 MODULE_VERSION("1.0.2");
69 setup_sg(struct scatterlist
*sg
, const void *address
, unsigned int length
)
71 sg_init_one(sg
, address
, length
);
75 #define SHA1_PAD_SIZE 40
78 * kernel crypto API needs its arguments to be in kmalloc'd memory, not in the module
79 * static data area. That means sha_pad needs to be kmalloc'd.
83 unsigned char sha_pad1
[SHA1_PAD_SIZE
];
84 unsigned char sha_pad2
[SHA1_PAD_SIZE
];
86 static struct sha_pad
*sha_pad
;
88 static inline void sha_pad_init(struct sha_pad
*shapad
)
90 memset(shapad
->sha_pad1
, 0x00, sizeof(shapad
->sha_pad1
));
91 memset(shapad
->sha_pad2
, 0xF2, sizeof(shapad
->sha_pad2
));
95 * State for an MPPE (de)compressor.
97 struct ppp_mppe_state
{
98 struct crypto_blkcipher
*arc4
;
99 struct crypto_hash
*sha1
;
100 unsigned char *sha1_digest
;
101 unsigned char master_key
[MPPE_MAX_KEY_LEN
];
102 unsigned char session_key
[MPPE_MAX_KEY_LEN
];
103 unsigned keylen
; /* key length in bytes */
104 /* NB: 128-bit == 16, 40-bit == 8! */
105 /* If we want to support 56-bit, */
106 /* the unit has to change to bits */
107 unsigned char bits
; /* MPPE control bits */
108 unsigned ccount
; /* 12-bit coherency count (seqno) */
109 unsigned stateful
; /* stateful mode flag */
110 int discard
; /* stateful mode packet loss flag */
111 int sanity_errors
; /* take down LCP if too many */
114 struct compstat stats
;
117 /* struct ppp_mppe_state.bits definitions */
118 #define MPPE_BIT_A 0x80 /* Encryption table were (re)inititalized */
119 #define MPPE_BIT_B 0x40 /* MPPC only (not implemented) */
120 #define MPPE_BIT_C 0x20 /* MPPC only (not implemented) */
121 #define MPPE_BIT_D 0x10 /* This is an encrypted frame */
123 #define MPPE_BIT_FLUSHED MPPE_BIT_A
124 #define MPPE_BIT_ENCRYPTED MPPE_BIT_D
126 #define MPPE_BITS(p) ((p)[4] & 0xf0)
127 #define MPPE_CCOUNT(p) ((((p)[4] & 0x0f) << 8) + (p)[5])
128 #define MPPE_CCOUNT_SPACE 0x1000 /* The size of the ccount space */
130 #define MPPE_OVHD 2 /* MPPE overhead/packet */
131 #define SANITY_MAX 1600 /* Max bogon factor we will tolerate */
134 * Key Derivation, from RFC 3078, RFC 3079.
135 * Equivalent to Get_Key() for MS-CHAP as described in RFC 3079.
137 static void get_new_key_from_sha(struct ppp_mppe_state
* state
)
139 struct hash_desc desc
;
140 struct scatterlist sg
[4];
143 nbytes
= setup_sg(&sg
[0], state
->master_key
, state
->keylen
);
144 nbytes
+= setup_sg(&sg
[1], sha_pad
->sha_pad1
,
145 sizeof(sha_pad
->sha_pad1
));
146 nbytes
+= setup_sg(&sg
[2], state
->session_key
, state
->keylen
);
147 nbytes
+= setup_sg(&sg
[3], sha_pad
->sha_pad2
,
148 sizeof(sha_pad
->sha_pad2
));
150 desc
.tfm
= state
->sha1
;
153 crypto_hash_digest(&desc
, sg
, nbytes
, state
->sha1_digest
);
157 * Perform the MPPE rekey algorithm, from RFC 3078, sec. 7.3.
158 * Well, not what's written there, but rather what they meant.
160 static void mppe_rekey(struct ppp_mppe_state
* state
, int initial_key
)
162 struct scatterlist sg_in
[1], sg_out
[1];
163 struct blkcipher_desc desc
= { .tfm
= state
->arc4
};
165 get_new_key_from_sha(state
);
167 crypto_blkcipher_setkey(state
->arc4
, state
->sha1_digest
,
169 setup_sg(sg_in
, state
->sha1_digest
, state
->keylen
);
170 setup_sg(sg_out
, state
->session_key
, state
->keylen
);
171 if (crypto_blkcipher_encrypt(&desc
, sg_out
, sg_in
,
172 state
->keylen
) != 0) {
173 printk(KERN_WARNING
"mppe_rekey: cipher_encrypt failed\n");
176 memcpy(state
->session_key
, state
->sha1_digest
, state
->keylen
);
178 if (state
->keylen
== 8) {
180 state
->session_key
[0] = 0xd1;
181 state
->session_key
[1] = 0x26;
182 state
->session_key
[2] = 0x9e;
184 crypto_blkcipher_setkey(state
->arc4
, state
->session_key
, state
->keylen
);
188 * Allocate space for a (de)compressor.
190 static void *mppe_alloc(unsigned char *options
, int optlen
)
192 struct ppp_mppe_state
*state
;
193 unsigned int digestsize
;
195 if (optlen
!= CILEN_MPPE
+ sizeof(state
->master_key
)
196 || options
[0] != CI_MPPE
|| options
[1] != CILEN_MPPE
)
199 state
= kzalloc(sizeof(*state
), GFP_KERNEL
);
204 state
->arc4
= crypto_alloc_blkcipher("ecb(arc4)", 0, CRYPTO_ALG_ASYNC
);
205 if (IS_ERR(state
->arc4
)) {
210 state
->sha1
= crypto_alloc_hash("sha1", 0, CRYPTO_ALG_ASYNC
);
211 if (IS_ERR(state
->sha1
)) {
216 digestsize
= crypto_hash_digestsize(state
->sha1
);
217 if (digestsize
< MPPE_MAX_KEY_LEN
)
220 state
->sha1_digest
= kmalloc(digestsize
, GFP_KERNEL
);
221 if (!state
->sha1_digest
)
225 memcpy(state
->master_key
, &options
[CILEN_MPPE
],
226 sizeof(state
->master_key
));
227 memcpy(state
->session_key
, state
->master_key
,
228 sizeof(state
->master_key
));
231 * We defer initial key generation until mppe_init(), as mppe_alloc()
232 * is called frequently during negotiation.
235 return (void *)state
;
238 if (state
->sha1_digest
)
239 kfree(state
->sha1_digest
);
241 crypto_free_hash(state
->sha1
);
243 crypto_free_blkcipher(state
->arc4
);
250 * Deallocate space for a (de)compressor.
252 static void mppe_free(void *arg
)
254 struct ppp_mppe_state
*state
= (struct ppp_mppe_state
*) arg
;
256 if (state
->sha1_digest
)
257 kfree(state
->sha1_digest
);
259 crypto_free_hash(state
->sha1
);
261 crypto_free_blkcipher(state
->arc4
);
267 * Initialize (de)compressor state.
270 mppe_init(void *arg
, unsigned char *options
, int optlen
, int unit
, int debug
,
271 const char *debugstr
)
273 struct ppp_mppe_state
*state
= (struct ppp_mppe_state
*) arg
;
274 unsigned char mppe_opts
;
276 if (optlen
!= CILEN_MPPE
277 || options
[0] != CI_MPPE
|| options
[1] != CILEN_MPPE
)
280 MPPE_CI_TO_OPTS(&options
[2], mppe_opts
);
281 if (mppe_opts
& MPPE_OPT_128
)
283 else if (mppe_opts
& MPPE_OPT_40
)
286 printk(KERN_WARNING
"%s[%d]: unknown key length\n", debugstr
,
290 if (mppe_opts
& MPPE_OPT_STATEFUL
)
293 /* Generate the initial session key. */
294 mppe_rekey(state
, 1);
298 char mkey
[sizeof(state
->master_key
) * 2 + 1];
299 char skey
[sizeof(state
->session_key
) * 2 + 1];
301 printk(KERN_DEBUG
"%s[%d]: initialized with %d-bit %s mode\n",
302 debugstr
, unit
, (state
->keylen
== 16) ? 128 : 40,
303 (state
->stateful
) ? "stateful" : "stateless");
305 for (i
= 0; i
< sizeof(state
->master_key
); i
++)
306 sprintf(mkey
+ i
* 2, "%02x", state
->master_key
[i
]);
307 for (i
= 0; i
< sizeof(state
->session_key
); i
++)
308 sprintf(skey
+ i
* 2, "%02x", state
->session_key
[i
]);
310 "%s[%d]: keys: master: %s initial session: %s\n",
311 debugstr
, unit
, mkey
, skey
);
315 * Initialize the coherency count. The initial value is not specified
316 * in RFC 3078, but we can make a reasonable assumption that it will
317 * start at 0. Setting it to the max here makes the comp/decomp code
318 * do the right thing (determined through experiment).
320 state
->ccount
= MPPE_CCOUNT_SPACE
- 1;
323 * Note that even though we have initialized the key table, we don't
324 * set the FLUSHED bit. This is contrary to RFC 3078, sec. 3.1.
326 state
->bits
= MPPE_BIT_ENCRYPTED
;
329 state
->debug
= debug
;
335 mppe_comp_init(void *arg
, unsigned char *options
, int optlen
, int unit
,
336 int hdrlen
, int debug
)
339 return mppe_init(arg
, options
, optlen
, unit
, debug
, "mppe_comp_init");
343 * We received a CCP Reset-Request (actually, we are sending a Reset-Ack),
344 * tell the compressor to rekey. Note that we MUST NOT rekey for
345 * every CCP Reset-Request; we only rekey on the next xmit packet.
346 * We might get multiple CCP Reset-Requests if our CCP Reset-Ack is lost.
347 * So, rekeying for every CCP Reset-Request is broken as the peer will not
348 * know how many times we've rekeyed. (If we rekey and THEN get another
349 * CCP Reset-Request, we must rekey again.)
351 static void mppe_comp_reset(void *arg
)
353 struct ppp_mppe_state
*state
= (struct ppp_mppe_state
*) arg
;
355 state
->bits
|= MPPE_BIT_FLUSHED
;
359 * Compress (encrypt) a packet.
360 * It's strange to call this a compressor, since the output is always
361 * MPPE_OVHD + 2 bytes larger than the input.
364 mppe_compress(void *arg
, unsigned char *ibuf
, unsigned char *obuf
,
365 int isize
, int osize
)
367 struct ppp_mppe_state
*state
= (struct ppp_mppe_state
*) arg
;
368 struct blkcipher_desc desc
= { .tfm
= state
->arc4
};
370 struct scatterlist sg_in
[1], sg_out
[1];
373 * Check that the protocol is in the range we handle.
375 proto
= PPP_PROTOCOL(ibuf
);
376 if (proto
< 0x0021 || proto
> 0x00fa)
379 /* Make sure we have enough room to generate an encrypted packet. */
380 if (osize
< isize
+ MPPE_OVHD
+ 2) {
381 /* Drop the packet if we should encrypt it, but can't. */
382 printk(KERN_DEBUG
"mppe_compress[%d]: osize too small! "
383 "(have: %d need: %d)\n", state
->unit
,
384 osize
, osize
+ MPPE_OVHD
+ 2);
388 osize
= isize
+ MPPE_OVHD
+ 2;
391 * Copy over the PPP header and set control bits.
393 obuf
[0] = PPP_ADDRESS(ibuf
);
394 obuf
[1] = PPP_CONTROL(ibuf
);
395 obuf
[2] = PPP_COMP
>> 8; /* isize + MPPE_OVHD + 1 */
396 obuf
[3] = PPP_COMP
; /* isize + MPPE_OVHD + 2 */
399 state
->ccount
= (state
->ccount
+ 1) % MPPE_CCOUNT_SPACE
;
400 if (state
->debug
>= 7)
401 printk(KERN_DEBUG
"mppe_compress[%d]: ccount %d\n", state
->unit
,
403 obuf
[0] = state
->ccount
>> 8;
404 obuf
[1] = state
->ccount
& 0xff;
406 if (!state
->stateful
|| /* stateless mode */
407 ((state
->ccount
& 0xff) == 0xff) || /* "flag" packet */
408 (state
->bits
& MPPE_BIT_FLUSHED
)) { /* CCP Reset-Request */
410 if (state
->debug
&& state
->stateful
)
411 printk(KERN_DEBUG
"mppe_compress[%d]: rekeying\n",
413 mppe_rekey(state
, 0);
414 state
->bits
|= MPPE_BIT_FLUSHED
;
416 obuf
[0] |= state
->bits
;
417 state
->bits
&= ~MPPE_BIT_FLUSHED
; /* reset for next xmit */
420 ibuf
+= 2; /* skip to proto field */
424 setup_sg(sg_in
, ibuf
, isize
);
425 setup_sg(sg_out
, obuf
, osize
);
426 if (crypto_blkcipher_encrypt(&desc
, sg_out
, sg_in
, isize
) != 0) {
427 printk(KERN_DEBUG
"crypto_cypher_encrypt failed\n");
431 state
->stats
.unc_bytes
+= isize
;
432 state
->stats
.unc_packets
++;
433 state
->stats
.comp_bytes
+= osize
;
434 state
->stats
.comp_packets
++;
440 * Since every frame grows by MPPE_OVHD + 2 bytes, this is always going
441 * to look bad ... and the longer the link is up the worse it will get.
443 static void mppe_comp_stats(void *arg
, struct compstat
*stats
)
445 struct ppp_mppe_state
*state
= (struct ppp_mppe_state
*) arg
;
447 *stats
= state
->stats
;
451 mppe_decomp_init(void *arg
, unsigned char *options
, int optlen
, int unit
,
452 int hdrlen
, int mru
, int debug
)
455 return mppe_init(arg
, options
, optlen
, unit
, debug
, "mppe_decomp_init");
459 * We received a CCP Reset-Ack. Just ignore it.
461 static void mppe_decomp_reset(void *arg
)
468 * Decompress (decrypt) an MPPE packet.
471 mppe_decompress(void *arg
, unsigned char *ibuf
, int isize
, unsigned char *obuf
,
474 struct ppp_mppe_state
*state
= (struct ppp_mppe_state
*) arg
;
475 struct blkcipher_desc desc
= { .tfm
= state
->arc4
};
477 int flushed
= MPPE_BITS(ibuf
) & MPPE_BIT_FLUSHED
;
479 struct scatterlist sg_in
[1], sg_out
[1];
481 if (isize
<= PPP_HDRLEN
+ MPPE_OVHD
) {
484 "mppe_decompress[%d]: short pkt (%d)\n",
490 * Make sure we have enough room to decrypt the packet.
491 * Note that for our test we only subtract 1 byte whereas in
492 * mppe_compress() we added 2 bytes (+MPPE_OVHD);
493 * this is to account for possible PFC.
495 if (osize
< isize
- MPPE_OVHD
- 1) {
496 printk(KERN_DEBUG
"mppe_decompress[%d]: osize too small! "
497 "(have: %d need: %d)\n", state
->unit
,
498 osize
, isize
- MPPE_OVHD
- 1);
501 osize
= isize
- MPPE_OVHD
- 2; /* assume no PFC */
503 ccount
= MPPE_CCOUNT(ibuf
);
504 if (state
->debug
>= 7)
505 printk(KERN_DEBUG
"mppe_decompress[%d]: ccount %d\n",
506 state
->unit
, ccount
);
508 /* sanity checks -- terminate with extreme prejudice */
509 if (!(MPPE_BITS(ibuf
) & MPPE_BIT_ENCRYPTED
)) {
511 "mppe_decompress[%d]: ENCRYPTED bit not set!\n",
513 state
->sanity_errors
+= 100;
516 if (!state
->stateful
&& !flushed
) {
517 printk(KERN_DEBUG
"mppe_decompress[%d]: FLUSHED bit not set in "
518 "stateless mode!\n", state
->unit
);
519 state
->sanity_errors
+= 100;
522 if (state
->stateful
&& ((ccount
& 0xff) == 0xff) && !flushed
) {
523 printk(KERN_DEBUG
"mppe_decompress[%d]: FLUSHED bit not set on "
524 "flag packet!\n", state
->unit
);
525 state
->sanity_errors
+= 100;
530 if (state
->sanity_errors
< SANITY_MAX
)
534 * Take LCP down if the peer is sending too many bogons.
535 * We don't want to do this for a single or just a few
536 * instances since it could just be due to packet corruption.
538 return DECOMP_FATALERROR
;
542 * Check the coherency count.
545 if (!state
->stateful
) {
546 /* RFC 3078, sec 8.1. Rekey for every packet. */
547 while (state
->ccount
!= ccount
) {
548 mppe_rekey(state
, 0);
549 state
->ccount
= (state
->ccount
+ 1) % MPPE_CCOUNT_SPACE
;
552 /* RFC 3078, sec 8.2. */
553 if (!state
->discard
) {
555 state
->ccount
= (state
->ccount
+ 1) % MPPE_CCOUNT_SPACE
;
556 if (ccount
!= state
->ccount
) {
558 * (ccount > state->ccount)
559 * Packet loss detected, enter the discard state.
560 * Signal the peer to rekey (by sending a CCP Reset-Request).
568 /* ccp.c will be silent (no additional CCP Reset-Requests). */
571 /* Rekey for every missed "flag" packet. */
572 while ((ccount
& ~0xff) !=
573 (state
->ccount
& ~0xff)) {
574 mppe_rekey(state
, 0);
577 256) % MPPE_CCOUNT_SPACE
;
582 state
->ccount
= ccount
;
584 * Another problem with RFC 3078 here. It implies that the
585 * peer need not send a Reset-Ack packet. But RFC 1962
586 * requires it. Hopefully, M$ does send a Reset-Ack; even
587 * though it isn't required for MPPE synchronization, it is
588 * required to reset CCP state.
593 mppe_rekey(state
, 0);
597 * Fill in the first part of the PPP header. The protocol field
598 * comes from the decrypted data.
600 obuf
[0] = PPP_ADDRESS(ibuf
); /* +1 */
601 obuf
[1] = PPP_CONTROL(ibuf
); /* +1 */
603 ibuf
+= PPP_HDRLEN
+ MPPE_OVHD
;
604 isize
-= PPP_HDRLEN
+ MPPE_OVHD
; /* -6 */
605 /* net osize: isize-4 */
608 * Decrypt the first byte in order to check if it is
609 * a compressed or uncompressed protocol field.
611 setup_sg(sg_in
, ibuf
, 1);
612 setup_sg(sg_out
, obuf
, 1);
613 if (crypto_blkcipher_decrypt(&desc
, sg_out
, sg_in
, 1) != 0) {
614 printk(KERN_DEBUG
"crypto_cypher_decrypt failed\n");
619 * Do PFC decompression.
620 * This would be nicer if we were given the actual sk_buff
621 * instead of a char *.
623 if ((obuf
[0] & 0x01) != 0) {
630 /* And finally, decrypt the rest of the packet. */
631 setup_sg(sg_in
, ibuf
+ 1, isize
- 1);
632 setup_sg(sg_out
, obuf
+ 1, osize
- 1);
633 if (crypto_blkcipher_decrypt(&desc
, sg_out
, sg_in
, isize
- 1)) {
634 printk(KERN_DEBUG
"crypto_cypher_decrypt failed\n");
638 state
->stats
.unc_bytes
+= osize
;
639 state
->stats
.unc_packets
++;
640 state
->stats
.comp_bytes
+= isize
;
641 state
->stats
.comp_packets
++;
643 /* good packet credit */
644 state
->sanity_errors
>>= 1;
650 * Incompressible data has arrived (this should never happen!).
651 * We should probably drop the link if the protocol is in the range
652 * of what should be encrypted. At the least, we should drop this
653 * packet. (How to do this?)
655 static void mppe_incomp(void *arg
, unsigned char *ibuf
, int icnt
)
657 struct ppp_mppe_state
*state
= (struct ppp_mppe_state
*) arg
;
660 (PPP_PROTOCOL(ibuf
) >= 0x0021 && PPP_PROTOCOL(ibuf
) <= 0x00fa))
662 "mppe_incomp[%d]: incompressible (unencrypted) data! "
663 "(proto %04x)\n", state
->unit
, PPP_PROTOCOL(ibuf
));
665 state
->stats
.inc_bytes
+= icnt
;
666 state
->stats
.inc_packets
++;
667 state
->stats
.unc_bytes
+= icnt
;
668 state
->stats
.unc_packets
++;
671 /*************************************************************
672 * Module interface table
673 *************************************************************/
676 * Procedures exported to if_ppp.c.
678 static struct compressor ppp_mppe
= {
679 .compress_proto
= CI_MPPE
,
680 .comp_alloc
= mppe_alloc
,
681 .comp_free
= mppe_free
,
682 .comp_init
= mppe_comp_init
,
683 .comp_reset
= mppe_comp_reset
,
684 .compress
= mppe_compress
,
685 .comp_stat
= mppe_comp_stats
,
686 .decomp_alloc
= mppe_alloc
,
687 .decomp_free
= mppe_free
,
688 .decomp_init
= mppe_decomp_init
,
689 .decomp_reset
= mppe_decomp_reset
,
690 .decompress
= mppe_decompress
,
691 .incomp
= mppe_incomp
,
692 .decomp_stat
= mppe_comp_stats
,
693 .owner
= THIS_MODULE
,
694 .comp_extra
= MPPE_PAD
,
700 * Prior to allowing load, try to load the arc4 and sha1 crypto
701 * libraries. The actual use will be allocated later, but
702 * this way the module will fail to insmod if they aren't available.
705 static int __init
ppp_mppe_init(void)
708 if (!(crypto_has_blkcipher("ecb(arc4)", 0, CRYPTO_ALG_ASYNC
) &&
709 crypto_has_hash("sha1", 0, CRYPTO_ALG_ASYNC
)))
712 sha_pad
= kmalloc(sizeof(struct sha_pad
), GFP_KERNEL
);
715 sha_pad_init(sha_pad
);
717 answer
= ppp_register_compressor(&ppp_mppe
);
720 printk(KERN_INFO
"PPP MPPE Compression module registered\n");
727 static void __exit
ppp_mppe_cleanup(void)
729 ppp_unregister_compressor(&ppp_mppe
);
733 module_init(ppp_mppe_init
);
734 module_exit(ppp_mppe_cleanup
);