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Linux 3.3-rc6
[linux/fpc-iii.git] / net / ieee802154 / 6lowpan.c
blobe4ecc1eef98c3b2aca2b583de283bc7bc7b2f44c
1 /*
2 * Copyright 2011, Siemens AG
3 * written by Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
4 */
5
6 /*
7 * Based on patches from Jon Smirl <jonsmirl@gmail.com>
8 * Copyright (c) 2011 Jon Smirl <jonsmirl@gmail.com>
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2
12 * as published by the Free Software Foundation.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write to the Free Software Foundation, Inc.,
21 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
22 */
23
24 /* Jon's code is based on 6lowpan implementation for Contiki which is:
25 * Copyright (c) 2008, Swedish Institute of Computer Science.
26 * All rights reserved.
27 *
28 * Redistribution and use in source and binary forms, with or without
29 * modification, are permitted provided that the following conditions
30 * are met:
31 * 1. Redistributions of source code must retain the above copyright
32 * notice, this list of conditions and the following disclaimer.
33 * 2. Redistributions in binary form must reproduce the above copyright
34 * notice, this list of conditions and the following disclaimer in the
35 * documentation and/or other materials provided with the distribution.
36 * 3. Neither the name of the Institute nor the names of its contributors
37 * may be used to endorse or promote products derived from this software
38 * without specific prior written permission.
39 *
40 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
41 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
44 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50 * SUCH DAMAGE.
51 */
52
53 #include <linux/bitops.h>
54 #include <linux/if_arp.h>
55 #include <linux/module.h>
56 #include <linux/moduleparam.h>
57 #include <linux/netdevice.h>
58 #include <net/af_ieee802154.h>
59 #include <net/ieee802154.h>
60 #include <net/ieee802154_netdev.h>
61 #include <net/ipv6.h>
62
63 #include "6lowpan.h"
64
65 /* TTL uncompression values */
66 static const u8 lowpan_ttl_values[] = {0, 1, 64, 255};
67
68 static LIST_HEAD(lowpan_devices);
69
70 /*
71 * Uncompression of linklocal:
72 * 0 -> 16 bytes from packet
73 * 1 -> 2 bytes from prefix - bunch of zeroes and 8 from packet
74 * 2 -> 2 bytes from prefix - zeroes + 2 from packet
75 * 3 -> 2 bytes from prefix - infer 8 bytes from lladdr
76 *
77 * NOTE: => the uncompress function does change 0xf to 0x10
78 * NOTE: 0x00 => no-autoconfig => unspecified
79 */
80 static const u8 lowpan_unc_llconf[] = {0x0f, 0x28, 0x22, 0x20};
81
82 /*
83 * Uncompression of ctx-based:
84 * 0 -> 0 bits from packet [unspecified / reserved]
85 * 1 -> 8 bytes from prefix - bunch of zeroes and 8 from packet
86 * 2 -> 8 bytes from prefix - zeroes + 2 from packet
87 * 3 -> 8 bytes from prefix - infer 8 bytes from lladdr
88 */
89 static const u8 lowpan_unc_ctxconf[] = {0x00, 0x88, 0x82, 0x80};
90
91 /*
92 * Uncompression of ctx-base
93 * 0 -> 0 bits from packet
94 * 1 -> 2 bytes from prefix - bunch of zeroes 5 from packet
95 * 2 -> 2 bytes from prefix - zeroes + 3 from packet
96 * 3 -> 2 bytes from prefix - infer 1 bytes from lladdr
97 */
98 static const u8 lowpan_unc_mxconf[] = {0x0f, 0x25, 0x23, 0x21};
99
100 /* Link local prefix */
101 static const u8 lowpan_llprefix[] = {0xfe, 0x80};
102
103 /* private device info */
104 struct lowpan_dev_info {
105 struct net_device *real_dev; /* real WPAN device ptr */
106 struct mutex dev_list_mtx; /* mutex for list ops */
107 };
108
109 struct lowpan_dev_record {
110 struct net_device *ldev;
111 struct list_head list;
112 };
113
114 struct lowpan_fragment {
115 struct sk_buff *skb; /* skb to be assembled */
116 spinlock_t lock; /* concurency lock */
117 u16 length; /* length to be assemled */
118 u32 bytes_rcv; /* bytes received */
119 u16 tag; /* current fragment tag */
120 struct timer_list timer; /* assembling timer */
121 struct list_head list; /* fragments list */
122 };
123
124 static unsigned short fragment_tag;
125 static LIST_HEAD(lowpan_fragments);
126 spinlock_t flist_lock;
127
128 static inline struct
129 lowpan_dev_info *lowpan_dev_info(const struct net_device *dev)
130 {
131 return netdev_priv(dev);
132 }
133
134 static inline void lowpan_address_flip(u8 *src, u8 *dest)
135 {
136 int i;
137 for (i = 0; i < IEEE802154_ADDR_LEN; i++)
138 (dest)[IEEE802154_ADDR_LEN - i - 1] = (src)[i];
139 }
140
141 /* list of all 6lowpan devices, uses for package delivering */
142 /* print data in line */
143 static inline void lowpan_raw_dump_inline(const char *caller, char *msg,
144 unsigned char *buf, int len)
145 {
146 #ifdef DEBUG
147 if (msg)
148 pr_debug("(%s) %s: ", caller, msg);
149 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_NONE,
150 16, 1, buf, len, false);
151 #endif /* DEBUG */
152 }
153
154 /*
155 * print data in a table format:
156 *
157 * addr: xx xx xx xx xx xx
158 * addr: xx xx xx xx xx xx
159 * ...
160 */
161 static inline void lowpan_raw_dump_table(const char *caller, char *msg,
162 unsigned char *buf, int len)
163 {
164 #ifdef DEBUG
165 if (msg)
166 pr_debug("(%s) %s:\n", caller, msg);
167 print_hex_dump(KERN_DEBUG, "\t", DUMP_PREFIX_OFFSET,
168 16, 1, buf, len, false);
169 #endif /* DEBUG */
170 }
171
172 static u8
173 lowpan_compress_addr_64(u8 **hc06_ptr, u8 shift, const struct in6_addr *ipaddr,
174 const unsigned char *lladdr)
175 {
176 u8 val = 0;
177
178 if (is_addr_mac_addr_based(ipaddr, lladdr))
179 val = 3; /* 0-bits */
180 else if (lowpan_is_iid_16_bit_compressable(ipaddr)) {
181 /* compress IID to 16 bits xxxx::XXXX */
182 memcpy(*hc06_ptr, &ipaddr->s6_addr16[7], 2);
183 *hc06_ptr += 2;
184 val = 2; /* 16-bits */
185 } else {
186 /* do not compress IID => xxxx::IID */
187 memcpy(*hc06_ptr, &ipaddr->s6_addr16[4], 8);
188 *hc06_ptr += 8;
189 val = 1; /* 64-bits */
190 }
191
192 return rol8(val, shift);
193 }
194
195 static void
196 lowpan_uip_ds6_set_addr_iid(struct in6_addr *ipaddr, unsigned char *lladdr)
197 {
198 memcpy(&ipaddr->s6_addr[8], lladdr, IEEE802154_ALEN);
199 /* second bit-flip (Universe/Local) is done according RFC2464 */
200 ipaddr->s6_addr[8] ^= 0x02;
201 }
202
203 /*
204 * Uncompress addresses based on a prefix and a postfix with zeroes in
205 * between. If the postfix is zero in length it will use the link address
206 * to configure the IP address (autoconf style).
207 * pref_post_count takes a byte where the first nibble specify prefix count
208 * and the second postfix count (NOTE: 15/0xf => 16 bytes copy).
209 */
210 static int
211 lowpan_uncompress_addr(struct sk_buff *skb, struct in6_addr *ipaddr,
212 u8 const *prefix, u8 pref_post_count, unsigned char *lladdr)
213 {
214 u8 prefcount = pref_post_count >> 4;
215 u8 postcount = pref_post_count & 0x0f;
216
217 /* full nibble 15 => 16 */
218 prefcount = (prefcount == 15 ? 16 : prefcount);
219 postcount = (postcount == 15 ? 16 : postcount);
220
221 if (lladdr)
222 lowpan_raw_dump_inline(__func__, "linklocal address",
223 lladdr, IEEE802154_ALEN);
224 if (prefcount > 0)
225 memcpy(ipaddr, prefix, prefcount);
226
227 if (prefcount + postcount < 16)
228 memset(&ipaddr->s6_addr[prefcount], 0,
229 16 - (prefcount + postcount));
230
231 if (postcount > 0) {
232 memcpy(&ipaddr->s6_addr[16 - postcount], skb->data, postcount);
233 skb_pull(skb, postcount);
234 } else if (prefcount > 0) {
235 if (lladdr == NULL)
236 return -EINVAL;
237
238 /* no IID based configuration if no prefix and no data */
239 lowpan_uip_ds6_set_addr_iid(ipaddr, lladdr);
240 }
241
242 pr_debug("(%s): uncompressing %d + %d => ", __func__, prefcount,
243 postcount);
244 lowpan_raw_dump_inline(NULL, NULL, ipaddr->s6_addr, 16);
245
246 return 0;
247 }
248
249 static void
250 lowpan_compress_udp_header(u8 **hc06_ptr, struct sk_buff *skb)
251 {
252 struct udphdr *uh = udp_hdr(skb);
253
254 pr_debug("(%s): UDP header compression\n", __func__);
255
256 if (((uh->source & LOWPAN_NHC_UDP_4BIT_MASK) ==
257 LOWPAN_NHC_UDP_4BIT_PORT) &&
258 ((uh->dest & LOWPAN_NHC_UDP_4BIT_MASK) ==
259 LOWPAN_NHC_UDP_4BIT_PORT)) {
260 pr_debug("(%s): both ports compression to 4 bits\n", __func__);
261 **hc06_ptr = LOWPAN_NHC_UDP_CS_P_11;
262 **(hc06_ptr + 1) = /* subtraction is faster */
263 (u8)((uh->dest - LOWPAN_NHC_UDP_4BIT_PORT) +
264 ((uh->source & LOWPAN_NHC_UDP_4BIT_PORT) << 4));
265 *hc06_ptr += 2;
266 } else if ((uh->dest & LOWPAN_NHC_UDP_8BIT_MASK) ==
267 LOWPAN_NHC_UDP_8BIT_PORT) {
268 pr_debug("(%s): remove 8 bits of dest\n", __func__);
269 **hc06_ptr = LOWPAN_NHC_UDP_CS_P_01;
270 memcpy(*hc06_ptr + 1, &uh->source, 2);
271 **(hc06_ptr + 3) = (u8)(uh->dest - LOWPAN_NHC_UDP_8BIT_PORT);
272 *hc06_ptr += 4;
273 } else if ((uh->source & LOWPAN_NHC_UDP_8BIT_MASK) ==
274 LOWPAN_NHC_UDP_8BIT_PORT) {
275 pr_debug("(%s): remove 8 bits of source\n", __func__);
276 **hc06_ptr = LOWPAN_NHC_UDP_CS_P_10;
277 memcpy(*hc06_ptr + 1, &uh->dest, 2);
278 **(hc06_ptr + 3) = (u8)(uh->source - LOWPAN_NHC_UDP_8BIT_PORT);
279 *hc06_ptr += 4;
280 } else {
281 pr_debug("(%s): can't compress header\n", __func__);
282 **hc06_ptr = LOWPAN_NHC_UDP_CS_P_00;
283 memcpy(*hc06_ptr + 1, &uh->source, 2);
284 memcpy(*hc06_ptr + 3, &uh->dest, 2);
285 *hc06_ptr += 5;
286 }
287
288 /* checksum is always inline */
289 memcpy(*hc06_ptr, &uh->check, 2);
290 *hc06_ptr += 2;
291 }
292
293 static u8 lowpan_fetch_skb_u8(struct sk_buff *skb)
294 {
295 u8 ret;
296
297 ret = skb->data[0];
298 skb_pull(skb, 1);
299
300 return ret;
301 }
302
303 static u16 lowpan_fetch_skb_u16(struct sk_buff *skb)
304 {
305 u16 ret;
306
307 BUG_ON(!pskb_may_pull(skb, 2));
308
309 ret = skb->data[0] | (skb->data[1] << 8);
310 skb_pull(skb, 2);
311 return ret;
312 }
313
314 static int
315 lowpan_uncompress_udp_header(struct sk_buff *skb)
316 {
317 struct udphdr *uh = udp_hdr(skb);
318 u8 tmp;
319
320 tmp = lowpan_fetch_skb_u8(skb);
321
322 if ((tmp & LOWPAN_NHC_UDP_MASK) == LOWPAN_NHC_UDP_ID) {
323 pr_debug("(%s): UDP header uncompression\n", __func__);
324 switch (tmp & LOWPAN_NHC_UDP_CS_P_11) {
325 case LOWPAN_NHC_UDP_CS_P_00:
326 memcpy(&uh->source, &skb->data[0], 2);
327 memcpy(&uh->dest, &skb->data[2], 2);
328 skb_pull(skb, 4);
329 break;
330 case LOWPAN_NHC_UDP_CS_P_01:
331 memcpy(&uh->source, &skb->data[0], 2);
332 uh->dest =
333 skb->data[2] + LOWPAN_NHC_UDP_8BIT_PORT;
334 skb_pull(skb, 3);
335 break;
336 case LOWPAN_NHC_UDP_CS_P_10:
337 uh->source = skb->data[0] + LOWPAN_NHC_UDP_8BIT_PORT;
338 memcpy(&uh->dest, &skb->data[1], 2);
339 skb_pull(skb, 3);
340 break;
341 case LOWPAN_NHC_UDP_CS_P_11:
342 uh->source =
343 LOWPAN_NHC_UDP_4BIT_PORT + (skb->data[0] >> 4);
344 uh->dest =
345 LOWPAN_NHC_UDP_4BIT_PORT + (skb->data[0] & 0x0f);
346 skb_pull(skb, 1);
347 break;
348 default:
349 pr_debug("(%s) ERROR: unknown UDP format\n", __func__);
350 goto err;
351 break;
352 }
353
354 pr_debug("(%s): uncompressed UDP ports: src = %d, dst = %d\n",
355 __func__, uh->source, uh->dest);
356
357 /* copy checksum */
358 memcpy(&uh->check, &skb->data[0], 2);
359 skb_pull(skb, 2);
360 } else {
361 pr_debug("(%s): ERROR: unsupported NH format\n", __func__);
362 goto err;
363 }
364
365 return 0;
366 err:
367 return -EINVAL;
368 }
369
370 static int lowpan_header_create(struct sk_buff *skb,
371 struct net_device *dev,
372 unsigned short type, const void *_daddr,
373 const void *_saddr, unsigned len)
374 {
375 u8 tmp, iphc0, iphc1, *hc06_ptr;
376 struct ipv6hdr *hdr;
377 const u8 *saddr = _saddr;
378 const u8 *daddr = _daddr;
379 u8 *head;
380 struct ieee802154_addr sa, da;
381
382 if (type != ETH_P_IPV6)
383 return 0;
384 /* TODO:
385 * if this package isn't ipv6 one, where should it be routed?
386 */
387 head = kzalloc(100, GFP_KERNEL);
388 if (head == NULL)
389 return -ENOMEM;
390
391 hdr = ipv6_hdr(skb);
392 hc06_ptr = head + 2;
393
394 pr_debug("(%s): IPv6 header dump:\n\tversion = %d\n\tlength = %d\n"
395 "\tnexthdr = 0x%02x\n\thop_lim = %d\n", __func__,
396 hdr->version, ntohs(hdr->payload_len), hdr->nexthdr,
397 hdr->hop_limit);
398
399 lowpan_raw_dump_table(__func__, "raw skb network header dump",
400 skb_network_header(skb), sizeof(struct ipv6hdr));
401
402 if (!saddr)
403 saddr = dev->dev_addr;
404
405 lowpan_raw_dump_inline(__func__, "saddr", (unsigned char *)saddr, 8);
406
407 /*
408 * As we copy some bit-length fields, in the IPHC encoding bytes,
409 * we sometimes use |=
410 * If the field is 0, and the current bit value in memory is 1,
411 * this does not work. We therefore reset the IPHC encoding here
412 */
413 iphc0 = LOWPAN_DISPATCH_IPHC;
414 iphc1 = 0;
415
416 /* TODO: context lookup */
417
418 lowpan_raw_dump_inline(__func__, "daddr", (unsigned char *)daddr, 8);
419
420 /*
421 * Traffic class, flow label
422 * If flow label is 0, compress it. If traffic class is 0, compress it
423 * We have to process both in the same time as the offset of traffic
424 * class depends on the presence of version and flow label
425 */
426
427 /* hc06 format of TC is ECN | DSCP , original one is DSCP | ECN */
428 tmp = (hdr->priority << 4) | (hdr->flow_lbl[0] >> 4);
429 tmp = ((tmp & 0x03) << 6) | (tmp >> 2);
430
431 if (((hdr->flow_lbl[0] & 0x0F) == 0) &&
432 (hdr->flow_lbl[1] == 0) && (hdr->flow_lbl[2] == 0)) {
433 /* flow label can be compressed */
434 iphc0 |= LOWPAN_IPHC_FL_C;
435 if ((hdr->priority == 0) &&
436 ((hdr->flow_lbl[0] & 0xF0) == 0)) {
437 /* compress (elide) all */
438 iphc0 |= LOWPAN_IPHC_TC_C;
439 } else {
440 /* compress only the flow label */
441 *hc06_ptr = tmp;
442 hc06_ptr += 1;
443 }
444 } else {
445 /* Flow label cannot be compressed */
446 if ((hdr->priority == 0) &&
447 ((hdr->flow_lbl[0] & 0xF0) == 0)) {
448 /* compress only traffic class */
449 iphc0 |= LOWPAN_IPHC_TC_C;
450 *hc06_ptr = (tmp & 0xc0) | (hdr->flow_lbl[0] & 0x0F);
451 memcpy(hc06_ptr + 1, &hdr->flow_lbl[1], 2);
452 hc06_ptr += 3;
453 } else {
454 /* compress nothing */
455 memcpy(hc06_ptr, &hdr, 4);
456 /* replace the top byte with new ECN | DSCP format */
457 *hc06_ptr = tmp;
458 hc06_ptr += 4;
459 }
460 }
461
462 /* NOTE: payload length is always compressed */
463
464 /* Next Header is compress if UDP */
465 if (hdr->nexthdr == UIP_PROTO_UDP)
466 iphc0 |= LOWPAN_IPHC_NH_C;
467
468 if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) {
469 *hc06_ptr = hdr->nexthdr;
470 hc06_ptr += 1;
471 }
472
473 /*
474 * Hop limit
475 * if 1: compress, encoding is 01
476 * if 64: compress, encoding is 10
477 * if 255: compress, encoding is 11
478 * else do not compress
479 */
480 switch (hdr->hop_limit) {
481 case 1:
482 iphc0 |= LOWPAN_IPHC_TTL_1;
483 break;
484 case 64:
485 iphc0 |= LOWPAN_IPHC_TTL_64;
486 break;
487 case 255:
488 iphc0 |= LOWPAN_IPHC_TTL_255;
489 break;
490 default:
491 *hc06_ptr = hdr->hop_limit;
492 break;
493 }
494
495 /* source address compression */
496 if (is_addr_unspecified(&hdr->saddr)) {
497 pr_debug("(%s): source address is unspecified, setting SAC\n",
498 __func__);
499 iphc1 |= LOWPAN_IPHC_SAC;
500 /* TODO: context lookup */
501 } else if (is_addr_link_local(&hdr->saddr)) {
502 pr_debug("(%s): source address is link-local\n", __func__);
503 iphc1 |= lowpan_compress_addr_64(&hc06_ptr,
504 LOWPAN_IPHC_SAM_BIT, &hdr->saddr, saddr);
505 } else {
506 pr_debug("(%s): send the full source address\n", __func__);
507 memcpy(hc06_ptr, &hdr->saddr.s6_addr16[0], 16);
508 hc06_ptr += 16;
509 }
510
511 /* destination address compression */
512 if (is_addr_mcast(&hdr->daddr)) {
513 pr_debug("(%s): destination address is multicast", __func__);
514 iphc1 |= LOWPAN_IPHC_M;
515 if (lowpan_is_mcast_addr_compressable8(&hdr->daddr)) {
516 pr_debug("compressed to 1 octet\n");
517 iphc1 |= LOWPAN_IPHC_DAM_11;
518 /* use last byte */
519 *hc06_ptr = hdr->daddr.s6_addr[15];
520 hc06_ptr += 1;
521 } else if (lowpan_is_mcast_addr_compressable32(&hdr->daddr)) {
522 pr_debug("compressed to 4 octets\n");
523 iphc1 |= LOWPAN_IPHC_DAM_10;
524 /* second byte + the last three */
525 *hc06_ptr = hdr->daddr.s6_addr[1];
526 memcpy(hc06_ptr + 1, &hdr->daddr.s6_addr[13], 3);
527 hc06_ptr += 4;
528 } else if (lowpan_is_mcast_addr_compressable48(&hdr->daddr)) {
529 pr_debug("compressed to 6 octets\n");
530 iphc1 |= LOWPAN_IPHC_DAM_01;
531 /* second byte + the last five */
532 *hc06_ptr = hdr->daddr.s6_addr[1];
533 memcpy(hc06_ptr + 1, &hdr->daddr.s6_addr[11], 5);
534 hc06_ptr += 6;
535 } else {
536 pr_debug("using full address\n");
537 iphc1 |= LOWPAN_IPHC_DAM_00;
538 memcpy(hc06_ptr, &hdr->daddr.s6_addr[0], 16);
539 hc06_ptr += 16;
540 }
541 } else {
542 pr_debug("(%s): destination address is unicast: ", __func__);
543 /* TODO: context lookup */
544 if (is_addr_link_local(&hdr->daddr)) {
545 pr_debug("destination address is link-local\n");
546 iphc1 |= lowpan_compress_addr_64(&hc06_ptr,
547 LOWPAN_IPHC_DAM_BIT, &hdr->daddr, daddr);
548 } else {
549 pr_debug("using full address\n");
550 memcpy(hc06_ptr, &hdr->daddr.s6_addr16[0], 16);
551 hc06_ptr += 16;
552 }
553 }
554
555 /* UDP header compression */
556 if (hdr->nexthdr == UIP_PROTO_UDP)
557 lowpan_compress_udp_header(&hc06_ptr, skb);
558
559 head[0] = iphc0;
560 head[1] = iphc1;
561
562 skb_pull(skb, sizeof(struct ipv6hdr));
563 memcpy(skb_push(skb, hc06_ptr - head), head, hc06_ptr - head);
564
565 kfree(head);
566
567 lowpan_raw_dump_table(__func__, "raw skb data dump", skb->data,
568 skb->len);
569
570 /*
571 * NOTE1: I'm still unsure about the fact that compression and WPAN
572 * header are created here and not later in the xmit. So wait for
573 * an opinion of net maintainers.
574 */
575 /*
576 * NOTE2: to be absolutely correct, we must derive PANid information
577 * from MAC subif of the 'dev' and 'real_dev' network devices, but
578 * this isn't implemented in mainline yet, so currently we assign 0xff
579 */
580 {
581 /* prepare wpan address data */
582 sa.addr_type = IEEE802154_ADDR_LONG;
583 sa.pan_id = 0xff;
584
585 da.addr_type = IEEE802154_ADDR_LONG;
586 da.pan_id = 0xff;
587
588 memcpy(&(da.hwaddr), daddr, 8);
589 memcpy(&(sa.hwaddr), saddr, 8);
590
591 mac_cb(skb)->flags = IEEE802154_FC_TYPE_DATA;
592
593 return dev_hard_header(skb, lowpan_dev_info(dev)->real_dev,
594 type, (void *)&da, (void *)&sa, skb->len);
595 }
596 }
597
598 static int lowpan_skb_deliver(struct sk_buff *skb, struct ipv6hdr *hdr)
599 {
600 struct sk_buff *new;
601 struct lowpan_dev_record *entry;
602 int stat = NET_RX_SUCCESS;
603
604 new = skb_copy_expand(skb, sizeof(struct ipv6hdr), skb_tailroom(skb),
605 GFP_ATOMIC);
606 kfree_skb(skb);
607
608 if (!new)
609 return -ENOMEM;
610
611 skb_push(new, sizeof(struct ipv6hdr));
612 skb_reset_network_header(new);
613 skb_copy_to_linear_data(new, hdr, sizeof(struct ipv6hdr));
614
615 new->protocol = htons(ETH_P_IPV6);
616 new->pkt_type = PACKET_HOST;
617
618 rcu_read_lock();
619 list_for_each_entry_rcu(entry, &lowpan_devices, list)
620 if (lowpan_dev_info(entry->ldev)->real_dev == new->dev) {
621 skb = skb_copy(new, GFP_ATOMIC);
622 if (!skb) {
623 stat = -ENOMEM;
624 break;
625 }
626
627 skb->dev = entry->ldev;
628 stat = netif_rx(skb);
629 }
630 rcu_read_unlock();
631
632 kfree_skb(new);
633
634 return stat;
635 }
636
637 static void lowpan_fragment_timer_expired(unsigned long entry_addr)
638 {
639 struct lowpan_fragment *entry = (struct lowpan_fragment *)entry_addr;
640
641 pr_debug("%s: timer expired for frame with tag %d\n", __func__,
642 entry->tag);
643
644 spin_lock(&flist_lock);
645 list_del(&entry->list);
646 spin_unlock(&flist_lock);
647
648 dev_kfree_skb(entry->skb);
649 kfree(entry);
650 }
651
652 static int
653 lowpan_process_data(struct sk_buff *skb)
654 {
655 struct ipv6hdr hdr;
656 u8 tmp, iphc0, iphc1, num_context = 0;
657 u8 *_saddr, *_daddr;
658 int err;
659
660 lowpan_raw_dump_table(__func__, "raw skb data dump", skb->data,
661 skb->len);
662 /* at least two bytes will be used for the encoding */
663 if (skb->len < 2)
664 goto drop;
665 iphc0 = lowpan_fetch_skb_u8(skb);
666
667 /* fragments assembling */
668 switch (iphc0 & LOWPAN_DISPATCH_MASK) {
669 case LOWPAN_DISPATCH_FRAG1:
670 case LOWPAN_DISPATCH_FRAGN:
671 {
672 struct lowpan_fragment *frame;
673 u8 len, offset;
674 u16 tag;
675 bool found = false;
676
677 len = lowpan_fetch_skb_u8(skb); /* frame length */
678 tag = lowpan_fetch_skb_u16(skb);
679
680 /*
681 * check if frame assembling with the same tag is
682 * already in progress
683 */
684 spin_lock(&flist_lock);
685
686 list_for_each_entry(frame, &lowpan_fragments, list)
687 if (frame->tag == tag) {
688 found = true;
689 break;
690 }
691
692 /* alloc new frame structure */
693 if (!found) {
694 frame = kzalloc(sizeof(struct lowpan_fragment),
695 GFP_ATOMIC);
696 if (!frame)
697 goto unlock_and_drop;
698
699 INIT_LIST_HEAD(&frame->list);
700
701 frame->length = (iphc0 & 7) | (len << 3);
702 frame->tag = tag;
703
704 /* allocate buffer for frame assembling */
705 frame->skb = alloc_skb(frame->length +
706 sizeof(struct ipv6hdr), GFP_ATOMIC);
707
708 if (!frame->skb) {
709 kfree(frame);
710 goto unlock_and_drop;
711 }
712
713 frame->skb->priority = skb->priority;
714 frame->skb->dev = skb->dev;
715
716 /* reserve headroom for uncompressed ipv6 header */
717 skb_reserve(frame->skb, sizeof(struct ipv6hdr));
718 skb_put(frame->skb, frame->length);
719
720 init_timer(&frame->timer);
721 /* time out is the same as for ipv6 - 60 sec */
722 frame->timer.expires = jiffies + LOWPAN_FRAG_TIMEOUT;
723 frame->timer.data = (unsigned long)frame;
724 frame->timer.function = lowpan_fragment_timer_expired;
725
726 add_timer(&frame->timer);
727
728 list_add_tail(&frame->list, &lowpan_fragments);
729 }
730
731 if ((iphc0 & LOWPAN_DISPATCH_MASK) == LOWPAN_DISPATCH_FRAG1)
732 goto unlock_and_drop;
733
734 offset = lowpan_fetch_skb_u8(skb); /* fetch offset */
735
736 /* if payload fits buffer, copy it */
737 if (likely((offset * 8 + skb->len) <= frame->length))
738 skb_copy_to_linear_data_offset(frame->skb, offset * 8,
739 skb->data, skb->len);
740 else
741 goto unlock_and_drop;
742
743 frame->bytes_rcv += skb->len;
744
745 /* frame assembling complete */
746 if ((frame->bytes_rcv == frame->length) &&
747 frame->timer.expires > jiffies) {
748 /* if timer haven't expired - first of all delete it */
749 del_timer(&frame->timer);
750 list_del(&frame->list);
751 spin_unlock(&flist_lock);
752
753 dev_kfree_skb(skb);
754 skb = frame->skb;
755 kfree(frame);
756 iphc0 = lowpan_fetch_skb_u8(skb);
757 break;
758 }
759 spin_unlock(&flist_lock);
760
761 return kfree_skb(skb), 0;
762 }
763 default:
764 break;
765 }
766
767 iphc1 = lowpan_fetch_skb_u8(skb);
768
769 _saddr = mac_cb(skb)->sa.hwaddr;
770 _daddr = mac_cb(skb)->da.hwaddr;
771
772 pr_debug("(%s): iphc0 = %02x, iphc1 = %02x\n", __func__, iphc0, iphc1);
773
774 /* another if the CID flag is set */
775 if (iphc1 & LOWPAN_IPHC_CID) {
776 pr_debug("(%s): CID flag is set, increase header with one\n",
777 __func__);
778 if (!skb->len)
779 goto drop;
780 num_context = lowpan_fetch_skb_u8(skb);
781 }
782
783 hdr.version = 6;
784
785 /* Traffic Class and Flow Label */
786 switch ((iphc0 & LOWPAN_IPHC_TF) >> 3) {
787 /*
788 * Traffic Class and FLow Label carried in-line
789 * ECN + DSCP + 4-bit Pad + Flow Label (4 bytes)
790 */
791 case 0: /* 00b */
792 if (!skb->len)
793 goto drop;
794 tmp = lowpan_fetch_skb_u8(skb);
795 memcpy(&hdr.flow_lbl, &skb->data[0], 3);
796 skb_pull(skb, 3);
797 hdr.priority = ((tmp >> 2) & 0x0f);
798 hdr.flow_lbl[0] = ((tmp >> 2) & 0x30) | (tmp << 6) |
799 (hdr.flow_lbl[0] & 0x0f);
800 break;
801 /*
802 * Traffic class carried in-line
803 * ECN + DSCP (1 byte), Flow Label is elided
804 */
805 case 1: /* 10b */
806 if (!skb->len)
807 goto drop;
808 tmp = lowpan_fetch_skb_u8(skb);
809 hdr.priority = ((tmp >> 2) & 0x0f);
810 hdr.flow_lbl[0] = ((tmp << 6) & 0xC0) | ((tmp >> 2) & 0x30);
811 hdr.flow_lbl[1] = 0;
812 hdr.flow_lbl[2] = 0;
813 break;
814 /*
815 * Flow Label carried in-line
816 * ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided
817 */
818 case 2: /* 01b */
819 if (!skb->len)
820 goto drop;
821 tmp = lowpan_fetch_skb_u8(skb);
822 hdr.flow_lbl[0] = (skb->data[0] & 0x0F) | ((tmp >> 2) & 0x30);
823 memcpy(&hdr.flow_lbl[1], &skb->data[0], 2);
824 skb_pull(skb, 2);
825 break;
826 /* Traffic Class and Flow Label are elided */
827 case 3: /* 11b */
828 hdr.priority = 0;
829 hdr.flow_lbl[0] = 0;
830 hdr.flow_lbl[1] = 0;
831 hdr.flow_lbl[2] = 0;
832 break;
833 default:
834 break;
835 }
836
837 /* Next Header */
838 if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) {
839 /* Next header is carried inline */
840 if (!skb->len)
841 goto drop;
842 hdr.nexthdr = lowpan_fetch_skb_u8(skb);
843 pr_debug("(%s): NH flag is set, next header is carried "
844 "inline: %02x\n", __func__, hdr.nexthdr);
845 }
846
847 /* Hop Limit */
848 if ((iphc0 & 0x03) != LOWPAN_IPHC_TTL_I)
849 hdr.hop_limit = lowpan_ttl_values[iphc0 & 0x03];
850 else {
851 if (!skb->len)
852 goto drop;
853 hdr.hop_limit = lowpan_fetch_skb_u8(skb);
854 }
855
856 /* Extract SAM to the tmp variable */
857 tmp = ((iphc1 & LOWPAN_IPHC_SAM) >> LOWPAN_IPHC_SAM_BIT) & 0x03;
858
859 /* Source address uncompression */
860 pr_debug("(%s): source address stateless compression\n", __func__);
861 err = lowpan_uncompress_addr(skb, &hdr.saddr, lowpan_llprefix,
862 lowpan_unc_llconf[tmp], skb->data);
863 if (err)
864 goto drop;
865
866 /* Extract DAM to the tmp variable */
867 tmp = ((iphc1 & LOWPAN_IPHC_DAM_11) >> LOWPAN_IPHC_DAM_BIT) & 0x03;
868
869 /* check for Multicast Compression */
870 if (iphc1 & LOWPAN_IPHC_M) {
871 if (iphc1 & LOWPAN_IPHC_DAC) {
872 pr_debug("(%s): destination address context-based "
873 "multicast compression\n", __func__);
874 /* TODO: implement this */
875 } else {
876 u8 prefix[] = {0xff, 0x02};
877
878 pr_debug("(%s): destination address non-context-based"
879 " multicast compression\n", __func__);
880 if (0 < tmp && tmp < 3) {
881 if (!skb->len)
882 goto drop;
883 else
884 prefix[1] = lowpan_fetch_skb_u8(skb);
885 }
886
887 err = lowpan_uncompress_addr(skb, &hdr.daddr, prefix,
888 lowpan_unc_mxconf[tmp], NULL);
889 if (err)
890 goto drop;
891 }
892 } else {
893 pr_debug("(%s): destination address stateless compression\n",
894 __func__);
895 err = lowpan_uncompress_addr(skb, &hdr.daddr, lowpan_llprefix,
896 lowpan_unc_llconf[tmp], skb->data);
897 if (err)
898 goto drop;
899 }
900
901 /* UDP data uncompression */
902 if (iphc0 & LOWPAN_IPHC_NH_C)
903 if (lowpan_uncompress_udp_header(skb))
904 goto drop;
905
906 /* Not fragmented package */
907 hdr.payload_len = htons(skb->len);
908
909 pr_debug("(%s): skb headroom size = %d, data length = %d\n", __func__,
910 skb_headroom(skb), skb->len);
911
912 pr_debug("(%s): IPv6 header dump:\n\tversion = %d\n\tlength = %d\n\t"
913 "nexthdr = 0x%02x\n\thop_lim = %d\n", __func__, hdr.version,
914 ntohs(hdr.payload_len), hdr.nexthdr, hdr.hop_limit);
915
916 lowpan_raw_dump_table(__func__, "raw header dump", (u8 *)&hdr,
917 sizeof(hdr));
918 return lowpan_skb_deliver(skb, &hdr);
919
920 unlock_and_drop:
921 spin_unlock(&flist_lock);
922 drop:
923 kfree_skb(skb);
924 return -EINVAL;
925 }
926
927 static int lowpan_set_address(struct net_device *dev, void *p)
928 {
929 struct sockaddr *sa = p;
930
931 if (netif_running(dev))
932 return -EBUSY;
933
934 /* TODO: validate addr */
935 memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
936
937 return 0;
938 }
939
940 static int lowpan_get_mac_header_length(struct sk_buff *skb)
941 {
942 /*
943 * Currently long addressing mode is supported only, so the overall
944 * header size is 21:
945 * FC SeqNum DPAN DA SA Sec
946 * 2 + 1 + 2 + 8 + 8 + 0 = 21
947 */
948 return 21;
949 }
950
951 static int
952 lowpan_fragment_xmit(struct sk_buff *skb, u8 *head,
953 int mlen, int plen, int offset)
954 {
955 struct sk_buff *frag;
956 int hlen, ret;
957
958 /* if payload length is zero, therefore it's a first fragment */
959 hlen = (plen == 0 ? LOWPAN_FRAG1_HEAD_SIZE : LOWPAN_FRAGN_HEAD_SIZE);
960
961 lowpan_raw_dump_inline(__func__, "6lowpan fragment header", head, hlen);
962
963 frag = dev_alloc_skb(hlen + mlen + plen + IEEE802154_MFR_SIZE);
964 if (!frag)
965 return -ENOMEM;
966
967 frag->priority = skb->priority;
968 frag->dev = skb->dev;
969
970 /* copy header, MFR and payload */
971 memcpy(skb_put(frag, mlen), skb->data, mlen);
972 memcpy(skb_put(frag, hlen), head, hlen);
973
974 if (plen)
975 skb_copy_from_linear_data_offset(skb, offset + mlen,
976 skb_put(frag, plen), plen);
977
978 lowpan_raw_dump_table(__func__, " raw fragment dump", frag->data,
979 frag->len);
980
981 ret = dev_queue_xmit(frag);
982
983 return ret;
984 }
985
986 static int
987 lowpan_skb_fragmentation(struct sk_buff *skb)
988 {
989 int err, header_length, payload_length, tag, offset = 0;
990 u8 head[5];
991
992 header_length = lowpan_get_mac_header_length(skb);
993 payload_length = skb->len - header_length;
994 tag = fragment_tag++;
995
996 /* first fragment header */
997 head[0] = LOWPAN_DISPATCH_FRAG1 | (payload_length & 0x7);
998 head[1] = (payload_length >> 3) & 0xff;
999 head[2] = tag & 0xff;
1000 head[3] = tag >> 8;
1001
1002 err = lowpan_fragment_xmit(skb, head, header_length, 0, 0);
1003
1004 /* next fragment header */
1005 head[0] &= ~LOWPAN_DISPATCH_FRAG1;
1006 head[0] |= LOWPAN_DISPATCH_FRAGN;
1007
1008 while ((payload_length - offset > 0) && (err >= 0)) {
1009 int len = LOWPAN_FRAG_SIZE;
1010
1011 head[4] = offset / 8;
1012
1013 if (payload_length - offset < len)
1014 len = payload_length - offset;
1015
1016 err = lowpan_fragment_xmit(skb, head, header_length,
1017 len, offset);
1018 offset += len;
1019 }
1020
1021 return err;
1022 }
1023
1024 static netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *dev)
1025 {
1026 int err = -1;
1027
1028 pr_debug("(%s): package xmit\n", __func__);
1029
1030 skb->dev = lowpan_dev_info(dev)->real_dev;
1031 if (skb->dev == NULL) {
1032 pr_debug("(%s) ERROR: no real wpan device found\n", __func__);
1033 goto error;
1034 }
1035
1036 if (skb->len <= IEEE802154_MTU) {
1037 err = dev_queue_xmit(skb);
1038 goto out;
1039 }
1040
1041 pr_debug("(%s): frame is too big, fragmentation is needed\n",
1042 __func__);
1043 err = lowpan_skb_fragmentation(skb);
1044 error:
1045 dev_kfree_skb(skb);
1046 out:
1047 if (err < 0)
1048 pr_debug("(%s): ERROR: xmit failed\n", __func__);
1049
1050 return (err < 0 ? NETDEV_TX_BUSY : NETDEV_TX_OK);
1051 }
1052
1053 static void lowpan_dev_free(struct net_device *dev)
1054 {
1055 dev_put(lowpan_dev_info(dev)->real_dev);
1056 free_netdev(dev);
1057 }
1058
1059 static struct header_ops lowpan_header_ops = {
1060 .create = lowpan_header_create,
1061 };
1062
1063 static const struct net_device_ops lowpan_netdev_ops = {
1064 .ndo_start_xmit = lowpan_xmit,
1065 .ndo_set_mac_address = lowpan_set_address,
1066 };
1067
1068 static void lowpan_setup(struct net_device *dev)
1069 {
1070 pr_debug("(%s)\n", __func__);
1071
1072 dev->addr_len = IEEE802154_ADDR_LEN;
1073 memset(dev->broadcast, 0xff, IEEE802154_ADDR_LEN);
1074 dev->type = ARPHRD_IEEE802154;
1075 /* Frame Control + Sequence Number + Address fields + Security Header */
1076 dev->hard_header_len = 2 + 1 + 20 + 14;
1077 dev->needed_tailroom = 2; /* FCS */
1078 dev->mtu = 1281;
1079 dev->tx_queue_len = 0;
1080 dev->flags = IFF_BROADCAST | IFF_MULTICAST;
1081 dev->watchdog_timeo = 0;
1082
1083 dev->netdev_ops = &lowpan_netdev_ops;
1084 dev->header_ops = &lowpan_header_ops;
1085 dev->destructor = lowpan_dev_free;
1086 }
1087
1088 static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[])
1089 {
1090 pr_debug("(%s)\n", __func__);
1091
1092 if (tb[IFLA_ADDRESS]) {
1093 if (nla_len(tb[IFLA_ADDRESS]) != IEEE802154_ADDR_LEN)
1094 return -EINVAL;
1095 }
1096 return 0;
1097 }
1098
1099 static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
1100 struct packet_type *pt, struct net_device *orig_dev)
1101 {
1102 if (!netif_running(dev))
1103 goto drop;
1104
1105 if (dev->type != ARPHRD_IEEE802154)
1106 goto drop;
1107
1108 /* check that it's our buffer */
1109 switch (skb->data[0] & 0xe0) {
1110 case LOWPAN_DISPATCH_IPHC: /* ipv6 datagram */
1111 case LOWPAN_DISPATCH_FRAG1: /* first fragment header */
1112 case LOWPAN_DISPATCH_FRAGN: /* next fragments headers */
1113 lowpan_process_data(skb);
1114 break;
1115 default:
1116 break;
1117 }
1118
1119 return NET_RX_SUCCESS;
1120
1121 drop:
1122 kfree_skb(skb);
1123 return NET_RX_DROP;
1124 }
1125
1126 static int lowpan_newlink(struct net *src_net, struct net_device *dev,
1127 struct nlattr *tb[], struct nlattr *data[])
1128 {
1129 struct net_device *real_dev;
1130 struct lowpan_dev_record *entry;
1131
1132 pr_debug("(%s)\n", __func__);
1133
1134 if (!tb[IFLA_LINK])
1135 return -EINVAL;
1136 /* find and hold real wpan device */
1137 real_dev = dev_get_by_index(src_net, nla_get_u32(tb[IFLA_LINK]));
1138 if (!real_dev)
1139 return -ENODEV;
1140
1141 lowpan_dev_info(dev)->real_dev = real_dev;
1142 mutex_init(&lowpan_dev_info(dev)->dev_list_mtx);
1143
1144 entry = kzalloc(sizeof(struct lowpan_dev_record), GFP_KERNEL);
1145 if (!entry) {
1146 dev_put(real_dev);
1147 lowpan_dev_info(dev)->real_dev = NULL;
1148 return -ENOMEM;
1149 }
1150
1151 entry->ldev = dev;
1152
1153 mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
1154 INIT_LIST_HEAD(&entry->list);
1155 list_add_tail(&entry->list, &lowpan_devices);
1156 mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
1157
1158 register_netdevice(dev);
1159
1160 return 0;
1161 }
1162
1163 static void lowpan_dellink(struct net_device *dev, struct list_head *head)
1164 {
1165 struct lowpan_dev_info *lowpan_dev = lowpan_dev_info(dev);
1166 struct net_device *real_dev = lowpan_dev->real_dev;
1167 struct lowpan_dev_record *entry;
1168 struct lowpan_dev_record *tmp;
1169
1170 ASSERT_RTNL();
1171
1172 mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
1173 list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) {
1174 if (entry->ldev == dev) {
1175 list_del(&entry->list);
1176 kfree(entry);
1177 }
1178 }
1179 mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
1180
1181 mutex_destroy(&lowpan_dev_info(dev)->dev_list_mtx);
1182
1183 unregister_netdevice_queue(dev, head);
1184
1185 dev_put(real_dev);
1186 }
1187
1188 static struct rtnl_link_ops lowpan_link_ops __read_mostly = {
1189 .kind = "lowpan",
1190 .priv_size = sizeof(struct lowpan_dev_info),
1191 .setup = lowpan_setup,
1192 .newlink = lowpan_newlink,
1193 .dellink = lowpan_dellink,
1194 .validate = lowpan_validate,
1195 };
1196
1197 static inline int __init lowpan_netlink_init(void)
1198 {
1199 return rtnl_link_register(&lowpan_link_ops);
1200 }
1201
1202 static inline void __init lowpan_netlink_fini(void)
1203 {
1204 rtnl_link_unregister(&lowpan_link_ops);
1205 }
1206
1207 static struct packet_type lowpan_packet_type = {
1208 .type = __constant_htons(ETH_P_IEEE802154),
1209 .func = lowpan_rcv,
1210 };
1211
1212 static int __init lowpan_init_module(void)
1213 {
1214 int err = 0;
1215
1216 pr_debug("(%s)\n", __func__);
1217
1218 err = lowpan_netlink_init();
1219 if (err < 0)
1220 goto out;
1221
1222 dev_add_pack(&lowpan_packet_type);
1223 out:
1224 return err;
1225 }
1226
1227 static void __exit lowpan_cleanup_module(void)
1228 {
1229 pr_debug("(%s)\n", __func__);
1230
1231 lowpan_netlink_fini();
1232
1233 dev_remove_pack(&lowpan_packet_type);
1234 }
1235
1236 module_init(lowpan_init_module);
1237 module_exit(lowpan_cleanup_module);
1238 MODULE_LICENSE("GPL");
1239 MODULE_ALIAS_RTNL_LINK("lowpan");
Linux with added FPC-III support