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-rw-r--r--drivers/net/ppp_mppe.c724
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diff --git a/drivers/net/ppp_mppe.c b/drivers/net/ppp_mppe.c
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1/*
2 * ppp_mppe.c - interface MPPE to the PPP code.
3 * This version is for use with Linux kernel 2.6.14+
4 *
5 * By Frank Cusack <fcusack@fcusack.com>.
6 * Copyright (c) 2002,2003,2004 Google, Inc.
7 * All rights reserved.
8 *
9 * License:
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.
14 *
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.
18 *
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.
23 *
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.
28 *
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
32 *
33 *
34 * Changelog:
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
39 * providing our own.
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
43 * deprecated in 2.6
44 */
45
46#include <linux/config.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>
55#include <linux/mm.h>
56#include <linux/ppp_defs.h>
57#include <linux/ppp-comp.h>
58#include <asm/scatterlist.h>
59
60#include "ppp_mppe.h"
61
62MODULE_AUTHOR("Frank Cusack <fcusack@fcusack.com>");
63MODULE_DESCRIPTION("Point-to-Point Protocol Microsoft Point-to-Point Encryption support");
64MODULE_LICENSE("Dual BSD/GPL");
65MODULE_ALIAS("ppp-compress-" __stringify(CI_MPPE));
66MODULE_VERSION("1.0.2");
67
68static void
69setup_sg(struct scatterlist *sg, const void *address, unsigned int length)
70{
71 sg[0].page = virt_to_page(address);
72 sg[0].offset = offset_in_page(address);
73 sg[0].length = length;
74}
75
76#define SHA1_PAD_SIZE 40
77
78/*
79 * kernel crypto API needs its arguments to be in kmalloc'd memory, not in the module
80 * static data area. That means sha_pad needs to be kmalloc'd.
81 */
82
83struct sha_pad {
84 unsigned char sha_pad1[SHA1_PAD_SIZE];
85 unsigned char sha_pad2[SHA1_PAD_SIZE];
86};
87static struct sha_pad *sha_pad;
88
89static inline void sha_pad_init(struct sha_pad *shapad)
90{
91 memset(shapad->sha_pad1, 0x00, sizeof(shapad->sha_pad1));
92 memset(shapad->sha_pad2, 0xF2, sizeof(shapad->sha_pad2));
93}
94
95/*
96 * State for an MPPE (de)compressor.
97 */
98struct ppp_mppe_state {
99 struct crypto_tfm *arc4;
100 struct crypto_tfm *sha1;
101 unsigned char *sha1_digest;
102 unsigned char master_key[MPPE_MAX_KEY_LEN];
103 unsigned char session_key[MPPE_MAX_KEY_LEN];
104 unsigned keylen; /* key length in bytes */
105 /* NB: 128-bit == 16, 40-bit == 8! */
106 /* If we want to support 56-bit, */
107 /* the unit has to change to bits */
108 unsigned char bits; /* MPPE control bits */
109 unsigned ccount; /* 12-bit coherency count (seqno) */
110 unsigned stateful; /* stateful mode flag */
111 int discard; /* stateful mode packet loss flag */
112 int sanity_errors; /* take down LCP if too many */
113 int unit;
114 int debug;
115 struct compstat stats;
116};
117
118/* struct ppp_mppe_state.bits definitions */
119#define MPPE_BIT_A 0x80 /* Encryption table were (re)inititalized */
120#define MPPE_BIT_B 0x40 /* MPPC only (not implemented) */
121#define MPPE_BIT_C 0x20 /* MPPC only (not implemented) */
122#define MPPE_BIT_D 0x10 /* This is an encrypted frame */
123
124#define MPPE_BIT_FLUSHED MPPE_BIT_A
125#define MPPE_BIT_ENCRYPTED MPPE_BIT_D
126
127#define MPPE_BITS(p) ((p)[4] & 0xf0)
128#define MPPE_CCOUNT(p) ((((p)[4] & 0x0f) << 8) + (p)[5])
129#define MPPE_CCOUNT_SPACE 0x1000 /* The size of the ccount space */
130
131#define MPPE_OVHD 2 /* MPPE overhead/packet */
132#define SANITY_MAX 1600 /* Max bogon factor we will tolerate */
133
134/*
135 * Key Derivation, from RFC 3078, RFC 3079.
136 * Equivalent to Get_Key() for MS-CHAP as described in RFC 3079.
137 */
138static void get_new_key_from_sha(struct ppp_mppe_state * state, unsigned char *InterimKey)
139{
140 struct scatterlist sg[4];
141
142 setup_sg(&sg[0], state->master_key, state->keylen);
143 setup_sg(&sg[1], sha_pad->sha_pad1, sizeof(sha_pad->sha_pad1));
144 setup_sg(&sg[2], state->session_key, state->keylen);
145 setup_sg(&sg[3], sha_pad->sha_pad2, sizeof(sha_pad->sha_pad2));
146
147 crypto_digest_digest (state->sha1, sg, 4, state->sha1_digest);
148
149 memcpy(InterimKey, state->sha1_digest, state->keylen);
150}
151
152/*
153 * Perform the MPPE rekey algorithm, from RFC 3078, sec. 7.3.
154 * Well, not what's written there, but rather what they meant.
155 */
156static void mppe_rekey(struct ppp_mppe_state * state, int initial_key)
157{
158 unsigned char InterimKey[MPPE_MAX_KEY_LEN];
159 struct scatterlist sg_in[1], sg_out[1];
160
161 get_new_key_from_sha(state, InterimKey);
162 if (!initial_key) {
163 crypto_cipher_setkey(state->arc4, InterimKey, state->keylen);
164 setup_sg(sg_in, InterimKey, state->keylen);
165 setup_sg(sg_out, state->session_key, state->keylen);
166 if (crypto_cipher_encrypt(state->arc4, sg_out, sg_in,
167 state->keylen) != 0) {
168 printk(KERN_WARNING "mppe_rekey: cipher_encrypt failed\n");
169 }
170 } else {
171 memcpy(state->session_key, InterimKey, state->keylen);
172 }
173 if (state->keylen == 8) {
174 /* See RFC 3078 */
175 state->session_key[0] = 0xd1;
176 state->session_key[1] = 0x26;
177 state->session_key[2] = 0x9e;
178 }
179 crypto_cipher_setkey(state->arc4, state->session_key, state->keylen);
180}
181
182/*
183 * Allocate space for a (de)compressor.
184 */
185static void *mppe_alloc(unsigned char *options, int optlen)
186{
187 struct ppp_mppe_state *state;
188 unsigned int digestsize;
189
190 if (optlen != CILEN_MPPE + sizeof(state->master_key)
191 || options[0] != CI_MPPE || options[1] != CILEN_MPPE)
192 goto out;
193
194 state = (struct ppp_mppe_state *) kmalloc(sizeof(*state), GFP_KERNEL);
195 if (state == NULL)
196 goto out;
197
198 memset(state, 0, sizeof(*state));
199
200 state->arc4 = crypto_alloc_tfm("arc4", 0);
201 if (!state->arc4)
202 goto out_free;
203
204 state->sha1 = crypto_alloc_tfm("sha1", 0);
205 if (!state->sha1)
206 goto out_free;
207
208 digestsize = crypto_tfm_alg_digestsize(state->sha1);
209 if (digestsize < MPPE_MAX_KEY_LEN)
210 goto out_free;
211
212 state->sha1_digest = kmalloc(digestsize, GFP_KERNEL);
213 if (!state->sha1_digest)
214 goto out_free;
215
216 /* Save keys. */
217 memcpy(state->master_key, &options[CILEN_MPPE],
218 sizeof(state->master_key));
219 memcpy(state->session_key, state->master_key,
220 sizeof(state->master_key));
221
222 /*
223 * We defer initial key generation until mppe_init(), as mppe_alloc()
224 * is called frequently during negotiation.
225 */
226
227 return (void *)state;
228
229 out_free:
230 if (state->sha1_digest)
231 kfree(state->sha1_digest);
232 if (state->sha1)
233 crypto_free_tfm(state->sha1);
234 if (state->arc4)
235 crypto_free_tfm(state->arc4);
236 kfree(state);
237 out:
238 return NULL;
239}
240
241/*
242 * Deallocate space for a (de)compressor.
243 */
244static void mppe_free(void *arg)
245{
246 struct ppp_mppe_state *state = (struct ppp_mppe_state *) arg;
247 if (state) {
248 if (state->sha1_digest)
249 kfree(state->sha1_digest);
250 if (state->sha1)
251 crypto_free_tfm(state->sha1);
252 if (state->arc4)
253 crypto_free_tfm(state->arc4);
254 kfree(state);
255 }
256}
257
258/*
259 * Initialize (de)compressor state.
260 */
261static int
262mppe_init(void *arg, unsigned char *options, int optlen, int unit, int debug,
263 const char *debugstr)
264{
265 struct ppp_mppe_state *state = (struct ppp_mppe_state *) arg;
266 unsigned char mppe_opts;
267
268 if (optlen != CILEN_MPPE
269 || options[0] != CI_MPPE || options[1] != CILEN_MPPE)
270 return 0;
271
272 MPPE_CI_TO_OPTS(&options[2], mppe_opts);
273 if (mppe_opts & MPPE_OPT_128)
274 state->keylen = 16;
275 else if (mppe_opts & MPPE_OPT_40)
276 state->keylen = 8;
277 else {
278 printk(KERN_WARNING "%s[%d]: unknown key length\n", debugstr,
279 unit);
280 return 0;
281 }
282 if (mppe_opts & MPPE_OPT_STATEFUL)
283 state->stateful = 1;
284
285 /* Generate the initial session key. */
286 mppe_rekey(state, 1);
287
288 if (debug) {
289 int i;
290 char mkey[sizeof(state->master_key) * 2 + 1];
291 char skey[sizeof(state->session_key) * 2 + 1];
292
293 printk(KERN_DEBUG "%s[%d]: initialized with %d-bit %s mode\n",
294 debugstr, unit, (state->keylen == 16) ? 128 : 40,
295 (state->stateful) ? "stateful" : "stateless");
296
297 for (i = 0; i < sizeof(state->master_key); i++)
298 sprintf(mkey + i * 2, "%02x", state->master_key[i]);
299 for (i = 0; i < sizeof(state->session_key); i++)
300 sprintf(skey + i * 2, "%02x", state->session_key[i]);
301 printk(KERN_DEBUG
302 "%s[%d]: keys: master: %s initial session: %s\n",
303 debugstr, unit, mkey, skey);
304 }
305
306 /*
307 * Initialize the coherency count. The initial value is not specified
308 * in RFC 3078, but we can make a reasonable assumption that it will
309 * start at 0. Setting it to the max here makes the comp/decomp code
310 * do the right thing (determined through experiment).
311 */
312 state->ccount = MPPE_CCOUNT_SPACE - 1;
313
314 /*
315 * Note that even though we have initialized the key table, we don't
316 * set the FLUSHED bit. This is contrary to RFC 3078, sec. 3.1.
317 */
318 state->bits = MPPE_BIT_ENCRYPTED;
319
320 state->unit = unit;
321 state->debug = debug;
322
323 return 1;
324}
325
326static int
327mppe_comp_init(void *arg, unsigned char *options, int optlen, int unit,
328 int hdrlen, int debug)
329{
330 /* ARGSUSED */
331 return mppe_init(arg, options, optlen, unit, debug, "mppe_comp_init");
332}
333
334/*
335 * We received a CCP Reset-Request (actually, we are sending a Reset-Ack),
336 * tell the compressor to rekey. Note that we MUST NOT rekey for
337 * every CCP Reset-Request; we only rekey on the next xmit packet.
338 * We might get multiple CCP Reset-Requests if our CCP Reset-Ack is lost.
339 * So, rekeying for every CCP Reset-Request is broken as the peer will not
340 * know how many times we've rekeyed. (If we rekey and THEN get another
341 * CCP Reset-Request, we must rekey again.)
342 */
343static void mppe_comp_reset(void *arg)
344{
345 struct ppp_mppe_state *state = (struct ppp_mppe_state *) arg;
346
347 state->bits |= MPPE_BIT_FLUSHED;
348}
349
350/*
351 * Compress (encrypt) a packet.
352 * It's strange to call this a compressor, since the output is always
353 * MPPE_OVHD + 2 bytes larger than the input.
354 */
355static int
356mppe_compress(void *arg, unsigned char *ibuf, unsigned char *obuf,
357 int isize, int osize)
358{
359 struct ppp_mppe_state *state = (struct ppp_mppe_state *) arg;
360 int proto;
361 struct scatterlist sg_in[1], sg_out[1];
362
363 /*
364 * Check that the protocol is in the range we handle.
365 */
366 proto = PPP_PROTOCOL(ibuf);
367 if (proto < 0x0021 || proto > 0x00fa)
368 return 0;
369
370 /* Make sure we have enough room to generate an encrypted packet. */
371 if (osize < isize + MPPE_OVHD + 2) {
372 /* Drop the packet if we should encrypt it, but can't. */
373 printk(KERN_DEBUG "mppe_compress[%d]: osize too small! "
374 "(have: %d need: %d)\n", state->unit,
375 osize, osize + MPPE_OVHD + 2);
376 return -1;
377 }
378
379 osize = isize + MPPE_OVHD + 2;
380
381 /*
382 * Copy over the PPP header and set control bits.
383 */
384 obuf[0] = PPP_ADDRESS(ibuf);
385 obuf[1] = PPP_CONTROL(ibuf);
386 obuf[2] = PPP_COMP >> 8; /* isize + MPPE_OVHD + 1 */
387 obuf[3] = PPP_COMP; /* isize + MPPE_OVHD + 2 */
388 obuf += PPP_HDRLEN;
389
390 state->ccount = (state->ccount + 1) % MPPE_CCOUNT_SPACE;
391 if (state->debug >= 7)
392 printk(KERN_DEBUG "mppe_compress[%d]: ccount %d\n", state->unit,
393 state->ccount);
394 obuf[0] = state->ccount >> 8;
395 obuf[1] = state->ccount & 0xff;
396
397 if (!state->stateful || /* stateless mode */
398 ((state->ccount & 0xff) == 0xff) || /* "flag" packet */
399 (state->bits & MPPE_BIT_FLUSHED)) { /* CCP Reset-Request */
400 /* We must rekey */
401 if (state->debug && state->stateful)
402 printk(KERN_DEBUG "mppe_compress[%d]: rekeying\n",
403 state->unit);
404 mppe_rekey(state, 0);
405 state->bits |= MPPE_BIT_FLUSHED;
406 }
407 obuf[0] |= state->bits;
408 state->bits &= ~MPPE_BIT_FLUSHED; /* reset for next xmit */
409
410 obuf += MPPE_OVHD;
411 ibuf += 2; /* skip to proto field */
412 isize -= 2;
413
414 /* Encrypt packet */
415 setup_sg(sg_in, ibuf, isize);
416 setup_sg(sg_out, obuf, osize);
417 if (crypto_cipher_encrypt(state->arc4, sg_out, sg_in, isize) != 0) {
418 printk(KERN_DEBUG "crypto_cypher_encrypt failed\n");
419 return -1;
420 }
421
422 state->stats.unc_bytes += isize;
423 state->stats.unc_packets++;
424 state->stats.comp_bytes += osize;
425 state->stats.comp_packets++;
426
427 return osize;
428}
429
430/*
431 * Since every frame grows by MPPE_OVHD + 2 bytes, this is always going
432 * to look bad ... and the longer the link is up the worse it will get.
433 */
434static void mppe_comp_stats(void *arg, struct compstat *stats)
435{
436 struct ppp_mppe_state *state = (struct ppp_mppe_state *) arg;
437
438 *stats = state->stats;
439}
440
441static int
442mppe_decomp_init(void *arg, unsigned char *options, int optlen, int unit,
443 int hdrlen, int mru, int debug)
444{
445 /* ARGSUSED */
446 return mppe_init(arg, options, optlen, unit, debug, "mppe_decomp_init");
447}
448
449/*
450 * We received a CCP Reset-Ack. Just ignore it.
451 */
452static void mppe_decomp_reset(void *arg)
453{
454 /* ARGSUSED */
455 return;
456}
457
458/*
459 * Decompress (decrypt) an MPPE packet.
460 */
461static int
462mppe_decompress(void *arg, unsigned char *ibuf, int isize, unsigned char *obuf,
463 int osize)
464{
465 struct ppp_mppe_state *state = (struct ppp_mppe_state *) arg;
466 unsigned ccount;
467 int flushed = MPPE_BITS(ibuf) & MPPE_BIT_FLUSHED;
468 int sanity = 0;
469 struct scatterlist sg_in[1], sg_out[1];
470
471 if (isize <= PPP_HDRLEN + MPPE_OVHD) {
472 if (state->debug)
473 printk(KERN_DEBUG
474 "mppe_decompress[%d]: short pkt (%d)\n",
475 state->unit, isize);
476 return DECOMP_ERROR;
477 }
478
479 /*
480 * Make sure we have enough room to decrypt the packet.
481 * Note that for our test we only subtract 1 byte whereas in
482 * mppe_compress() we added 2 bytes (+MPPE_OVHD);
483 * this is to account for possible PFC.
484 */
485 if (osize < isize - MPPE_OVHD - 1) {
486 printk(KERN_DEBUG "mppe_decompress[%d]: osize too small! "
487 "(have: %d need: %d)\n", state->unit,
488 osize, isize - MPPE_OVHD - 1);
489 return DECOMP_ERROR;
490 }
491 osize = isize - MPPE_OVHD - 2; /* assume no PFC */
492
493 ccount = MPPE_CCOUNT(ibuf);
494 if (state->debug >= 7)
495 printk(KERN_DEBUG "mppe_decompress[%d]: ccount %d\n",
496 state->unit, ccount);
497
498 /* sanity checks -- terminate with extreme prejudice */
499 if (!(MPPE_BITS(ibuf) & MPPE_BIT_ENCRYPTED)) {
500 printk(KERN_DEBUG
501 "mppe_decompress[%d]: ENCRYPTED bit not set!\n",
502 state->unit);
503 state->sanity_errors += 100;
504 sanity = 1;
505 }
506 if (!state->stateful && !flushed) {
507 printk(KERN_DEBUG "mppe_decompress[%d]: FLUSHED bit not set in "
508 "stateless mode!\n", state->unit);
509 state->sanity_errors += 100;
510 sanity = 1;
511 }
512 if (state->stateful && ((ccount & 0xff) == 0xff) && !flushed) {
513 printk(KERN_DEBUG "mppe_decompress[%d]: FLUSHED bit not set on "
514 "flag packet!\n", state->unit);
515 state->sanity_errors += 100;
516 sanity = 1;
517 }
518
519 if (sanity) {
520 if (state->sanity_errors < SANITY_MAX)
521 return DECOMP_ERROR;
522 else
523 /*
524 * Take LCP down if the peer is sending too many bogons.
525 * We don't want to do this for a single or just a few
526 * instances since it could just be due to packet corruption.
527 */
528 return DECOMP_FATALERROR;
529 }
530
531 /*
532 * Check the coherency count.
533 */
534
535 if (!state->stateful) {
536 /* RFC 3078, sec 8.1. Rekey for every packet. */
537 while (state->ccount != ccount) {
538 mppe_rekey(state, 0);
539 state->ccount = (state->ccount + 1) % MPPE_CCOUNT_SPACE;
540 }
541 } else {
542 /* RFC 3078, sec 8.2. */
543 if (!state->discard) {
544 /* normal state */
545 state->ccount = (state->ccount + 1) % MPPE_CCOUNT_SPACE;
546 if (ccount != state->ccount) {
547 /*
548 * (ccount > state->ccount)
549 * Packet loss detected, enter the discard state.
550 * Signal the peer to rekey (by sending a CCP Reset-Request).
551 */
552 state->discard = 1;
553 return DECOMP_ERROR;
554 }
555 } else {
556 /* discard state */
557 if (!flushed) {
558 /* ccp.c will be silent (no additional CCP Reset-Requests). */
559 return DECOMP_ERROR;
560 } else {
561 /* Rekey for every missed "flag" packet. */
562 while ((ccount & ~0xff) !=
563 (state->ccount & ~0xff)) {
564 mppe_rekey(state, 0);
565 state->ccount =
566 (state->ccount +
567 256) % MPPE_CCOUNT_SPACE;
568 }
569
570 /* reset */
571 state->discard = 0;
572 state->ccount = ccount;
573 /*
574 * Another problem with RFC 3078 here. It implies that the
575 * peer need not send a Reset-Ack packet. But RFC 1962
576 * requires it. Hopefully, M$ does send a Reset-Ack; even
577 * though it isn't required for MPPE synchronization, it is
578 * required to reset CCP state.
579 */
580 }
581 }
582 if (flushed)
583 mppe_rekey(state, 0);
584 }
585
586 /*
587 * Fill in the first part of the PPP header. The protocol field
588 * comes from the decrypted data.
589 */
590 obuf[0] = PPP_ADDRESS(ibuf); /* +1 */
591 obuf[1] = PPP_CONTROL(ibuf); /* +1 */
592 obuf += 2;
593 ibuf += PPP_HDRLEN + MPPE_OVHD;
594 isize -= PPP_HDRLEN + MPPE_OVHD; /* -6 */
595 /* net osize: isize-4 */
596
597 /*
598 * Decrypt the first byte in order to check if it is
599 * a compressed or uncompressed protocol field.
600 */
601 setup_sg(sg_in, ibuf, 1);
602 setup_sg(sg_out, obuf, 1);
603 if (crypto_cipher_decrypt(state->arc4, sg_out, sg_in, 1) != 0) {
604 printk(KERN_DEBUG "crypto_cypher_decrypt failed\n");
605 return DECOMP_ERROR;
606 }
607
608 /*
609 * Do PFC decompression.
610 * This would be nicer if we were given the actual sk_buff
611 * instead of a char *.
612 */
613 if ((obuf[0] & 0x01) != 0) {
614 obuf[1] = obuf[0];
615 obuf[0] = 0;
616 obuf++;
617 osize++;
618 }
619
620 /* And finally, decrypt the rest of the packet. */
621 setup_sg(sg_in, ibuf + 1, isize - 1);
622 setup_sg(sg_out, obuf + 1, osize - 1);
623 if (crypto_cipher_decrypt(state->arc4, sg_out, sg_in, isize - 1) != 0) {
624 printk(KERN_DEBUG "crypto_cypher_decrypt failed\n");
625 return DECOMP_ERROR;
626 }
627
628 state->stats.unc_bytes += osize;
629 state->stats.unc_packets++;
630 state->stats.comp_bytes += isize;
631 state->stats.comp_packets++;
632
633 /* good packet credit */
634 state->sanity_errors >>= 1;
635
636 return osize;
637}
638
639/*
640 * Incompressible data has arrived (this should never happen!).
641 * We should probably drop the link if the protocol is in the range
642 * of what should be encrypted. At the least, we should drop this
643 * packet. (How to do this?)
644 */
645static void mppe_incomp(void *arg, unsigned char *ibuf, int icnt)
646{
647 struct ppp_mppe_state *state = (struct ppp_mppe_state *) arg;
648
649 if (state->debug &&
650 (PPP_PROTOCOL(ibuf) >= 0x0021 && PPP_PROTOCOL(ibuf) <= 0x00fa))
651 printk(KERN_DEBUG
652 "mppe_incomp[%d]: incompressible (unencrypted) data! "
653 "(proto %04x)\n", state->unit, PPP_PROTOCOL(ibuf));
654
655 state->stats.inc_bytes += icnt;
656 state->stats.inc_packets++;
657 state->stats.unc_bytes += icnt;
658 state->stats.unc_packets++;
659}
660
661/*************************************************************
662 * Module interface table
663 *************************************************************/
664
665/*
666 * Procedures exported to if_ppp.c.
667 */
668static struct compressor ppp_mppe = {
669 .compress_proto = CI_MPPE,
670 .comp_alloc = mppe_alloc,
671 .comp_free = mppe_free,
672 .comp_init = mppe_comp_init,
673 .comp_reset = mppe_comp_reset,
674 .compress = mppe_compress,
675 .comp_stat = mppe_comp_stats,
676 .decomp_alloc = mppe_alloc,
677 .decomp_free = mppe_free,
678 .decomp_init = mppe_decomp_init,
679 .decomp_reset = mppe_decomp_reset,
680 .decompress = mppe_decompress,
681 .incomp = mppe_incomp,
682 .decomp_stat = mppe_comp_stats,
683 .owner = THIS_MODULE,
684 .comp_extra = MPPE_PAD,
685};
686
687/*
688 * ppp_mppe_init()
689 *
690 * Prior to allowing load, try to load the arc4 and sha1 crypto
691 * libraries. The actual use will be allocated later, but
692 * this way the module will fail to insmod if they aren't available.
693 */
694
695static int __init ppp_mppe_init(void)
696{
697 int answer;
698 if (!(crypto_alg_available("arc4", 0) &&
699 crypto_alg_available("sha1", 0)))
700 return -ENODEV;
701
702 sha_pad = kmalloc(sizeof(struct sha_pad), GFP_KERNEL);
703 if (!sha_pad)
704 return -ENOMEM;
705 sha_pad_init(sha_pad);
706
707 answer = ppp_register_compressor(&ppp_mppe);
708
709 if (answer == 0)
710 printk(KERN_INFO "PPP MPPE Compression module registered\n");
711 else
712 kfree(sha_pad);
713
714 return answer;
715}
716
717static void __exit ppp_mppe_cleanup(void)
718{
719 ppp_unregister_compressor(&ppp_mppe);
720 kfree(sha_pad);
721}
722
723module_init(ppp_mppe_init);
724module_exit(ppp_mppe_cleanup);
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-21 03:55:41 -0500