aboutsummaryrefslogtreecommitdiffstats
path: root/net/ieee802154/6lowpan.c
diff options
context:
space:
mode:
Diffstat (limited to 'net/ieee802154/6lowpan.c')
-rw-r--r--net/ieee802154/6lowpan.c885
1 files changed, 885 insertions, 0 deletions
diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
new file mode 100644
index 000000000000..cf304cc8c8ef
--- /dev/null
+++ b/net/ieee802154/6lowpan.c
@@ -0,0 +1,885 @@
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#define DEBUG
54
55#include <linux/bitops.h>
56#include <linux/if_arp.h>
57#include <linux/module.h>
58#include <linux/moduleparam.h>
59#include <linux/netdevice.h>
60#include <net/af_ieee802154.h>
61#include <net/ieee802154.h>
62#include <net/ieee802154_netdev.h>
63#include <net/ipv6.h>
64
65#include "6lowpan.h"
66
67/* TTL uncompression values */
68static const u8 lowpan_ttl_values[] = {0, 1, 64, 255};
69
70static LIST_HEAD(lowpan_devices);
71
72/*
73 * Uncompression of linklocal:
74 * 0 -> 16 bytes from packet
75 * 1 -> 2 bytes from prefix - bunch of zeroes and 8 from packet
76 * 2 -> 2 bytes from prefix - zeroes + 2 from packet
77 * 3 -> 2 bytes from prefix - infer 8 bytes from lladdr
78 *
79 * NOTE: => the uncompress function does change 0xf to 0x10
80 * NOTE: 0x00 => no-autoconfig => unspecified
81 */
82static const u8 lowpan_unc_llconf[] = {0x0f, 0x28, 0x22, 0x20};
83
84/*
85 * Uncompression of ctx-based:
86 * 0 -> 0 bits from packet [unspecified / reserved]
87 * 1 -> 8 bytes from prefix - bunch of zeroes and 8 from packet
88 * 2 -> 8 bytes from prefix - zeroes + 2 from packet
89 * 3 -> 8 bytes from prefix - infer 8 bytes from lladdr
90 */
91static const u8 lowpan_unc_ctxconf[] = {0x00, 0x88, 0x82, 0x80};
92
93/*
94 * Uncompression of ctx-base
95 * 0 -> 0 bits from packet
96 * 1 -> 2 bytes from prefix - bunch of zeroes 5 from packet
97 * 2 -> 2 bytes from prefix - zeroes + 3 from packet
98 * 3 -> 2 bytes from prefix - infer 1 bytes from lladdr
99 */
100static const u8 lowpan_unc_mxconf[] = {0x0f, 0x25, 0x23, 0x21};
101
102/* Link local prefix */
103static const u8 lowpan_llprefix[] = {0xfe, 0x80};
104
105/* private device info */
106struct lowpan_dev_info {
107 struct net_device *real_dev; /* real WPAN device ptr */
108 struct mutex dev_list_mtx; /* mutex for list ops */
109};
110
111struct lowpan_dev_record {
112 struct net_device *ldev;
113 struct list_head list;
114};
115
116static inline struct
117lowpan_dev_info *lowpan_dev_info(const struct net_device *dev)
118{
119 return netdev_priv(dev);
120}
121
122static inline void lowpan_address_flip(u8 *src, u8 *dest)
123{
124 int i;
125 for (i = 0; i < IEEE802154_ADDR_LEN; i++)
126 (dest)[IEEE802154_ADDR_LEN - i - 1] = (src)[i];
127}
128
129/* list of all 6lowpan devices, uses for package delivering */
130/* print data in line */
131static inline void lowpan_raw_dump_inline(const char *caller, char *msg,
132 unsigned char *buf, int len)
133{
134#ifdef DEBUG
135 if (msg)
136 pr_debug("(%s) %s: ", caller, msg);
137 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_NONE,
138 16, 1, buf, len, false);
139#endif /* DEBUG */
140}
141
142/*
143 * print data in a table format:
144 *
145 * addr: xx xx xx xx xx xx
146 * addr: xx xx xx xx xx xx
147 * ...
148 */
149static inline void lowpan_raw_dump_table(const char *caller, char *msg,
150 unsigned char *buf, int len)
151{
152#ifdef DEBUG
153 if (msg)
154 pr_debug("(%s) %s:\n", caller, msg);
155 print_hex_dump(KERN_DEBUG, "\t", DUMP_PREFIX_OFFSET,
156 16, 1, buf, len, false);
157#endif /* DEBUG */
158}
159
160static u8
161lowpan_compress_addr_64(u8 **hc06_ptr, u8 shift, const struct in6_addr *ipaddr,
162 const unsigned char *lladdr)
163{
164 u8 val = 0;
165
166 if (is_addr_mac_addr_based(ipaddr, lladdr))
167 val = 3; /* 0-bits */
168 else if (lowpan_is_iid_16_bit_compressable(ipaddr)) {
169 /* compress IID to 16 bits xxxx::XXXX */
170 memcpy(*hc06_ptr, &ipaddr->s6_addr16[7], 2);
171 *hc06_ptr += 2;
172 val = 2; /* 16-bits */
173 } else {
174 /* do not compress IID => xxxx::IID */
175 memcpy(*hc06_ptr, &ipaddr->s6_addr16[4], 8);
176 *hc06_ptr += 8;
177 val = 1; /* 64-bits */
178 }
179
180 return rol8(val, shift);
181}
182
183static void
184lowpan_uip_ds6_set_addr_iid(struct in6_addr *ipaddr, unsigned char *lladdr)
185{
186 memcpy(&ipaddr->s6_addr[8], lladdr, IEEE802154_ALEN);
187 /* second bit-flip (Universe/Local) is done according RFC2464 */
188 ipaddr->s6_addr[8] ^= 0x02;
189}
190
191/*
192 * Uncompress addresses based on a prefix and a postfix with zeroes in
193 * between. If the postfix is zero in length it will use the link address
194 * to configure the IP address (autoconf style).
195 * pref_post_count takes a byte where the first nibble specify prefix count
196 * and the second postfix count (NOTE: 15/0xf => 16 bytes copy).
197 */
198static int
199lowpan_uncompress_addr(struct sk_buff *skb, struct in6_addr *ipaddr,
200 u8 const *prefix, u8 pref_post_count, unsigned char *lladdr)
201{
202 u8 prefcount = pref_post_count >> 4;
203 u8 postcount = pref_post_count & 0x0f;
204
205 /* full nibble 15 => 16 */
206 prefcount = (prefcount == 15 ? 16 : prefcount);
207 postcount = (postcount == 15 ? 16 : postcount);
208
209 if (lladdr)
210 lowpan_raw_dump_inline(__func__, "linklocal address",
211 lladdr, IEEE802154_ALEN);
212 if (prefcount > 0)
213 memcpy(ipaddr, prefix, prefcount);
214
215 if (prefcount + postcount < 16)
216 memset(&ipaddr->s6_addr[prefcount], 0,
217 16 - (prefcount + postcount));
218
219 if (postcount > 0) {
220 memcpy(&ipaddr->s6_addr[16 - postcount], skb->data, postcount);
221 skb_pull(skb, postcount);
222 } else if (prefcount > 0) {
223 if (lladdr == NULL)
224 return -EINVAL;
225
226 /* no IID based configuration if no prefix and no data */
227 lowpan_uip_ds6_set_addr_iid(ipaddr, lladdr);
228 }
229
230 pr_debug("(%s): uncompressing %d + %d => ", __func__, prefcount,
231 postcount);
232 lowpan_raw_dump_inline(NULL, NULL, ipaddr->s6_addr, 16);
233
234 return 0;
235}
236
237static u8 lowpan_fetch_skb_u8(struct sk_buff *skb)
238{
239 u8 ret;
240
241 ret = skb->data[0];
242 skb_pull(skb, 1);
243
244 return ret;
245}
246
247static int lowpan_header_create(struct sk_buff *skb,
248 struct net_device *dev,
249 unsigned short type, const void *_daddr,
250 const void *_saddr, unsigned len)
251{
252 u8 tmp, iphc0, iphc1, *hc06_ptr;
253 struct ipv6hdr *hdr;
254 const u8 *saddr = _saddr;
255 const u8 *daddr = _daddr;
256 u8 *head;
257 struct ieee802154_addr sa, da;
258
259 if (type != ETH_P_IPV6)
260 return 0;
261 /* TODO:
262 * if this package isn't ipv6 one, where should it be routed?
263 */
264 head = kzalloc(100, GFP_KERNEL);
265 if (head == NULL)
266 return -ENOMEM;
267
268 hdr = ipv6_hdr(skb);
269 hc06_ptr = head + 2;
270
271 pr_debug("(%s): IPv6 header dump:\n\tversion = %d\n\tlength = %d\n"
272 "\tnexthdr = 0x%02x\n\thop_lim = %d\n", __func__,
273 hdr->version, ntohs(hdr->payload_len), hdr->nexthdr,
274 hdr->hop_limit);
275
276 lowpan_raw_dump_table(__func__, "raw skb network header dump",
277 skb_network_header(skb), sizeof(struct ipv6hdr));
278
279 if (!saddr)
280 saddr = dev->dev_addr;
281
282 lowpan_raw_dump_inline(__func__, "saddr", (unsigned char *)saddr, 8);
283
284 /*
285 * As we copy some bit-length fields, in the IPHC encoding bytes,
286 * we sometimes use |=
287 * If the field is 0, and the current bit value in memory is 1,
288 * this does not work. We therefore reset the IPHC encoding here
289 */
290 iphc0 = LOWPAN_DISPATCH_IPHC;
291 iphc1 = 0;
292
293 /* TODO: context lookup */
294
295 lowpan_raw_dump_inline(__func__, "daddr", (unsigned char *)daddr, 8);
296
297 /*
298 * Traffic class, flow label
299 * If flow label is 0, compress it. If traffic class is 0, compress it
300 * We have to process both in the same time as the offset of traffic
301 * class depends on the presence of version and flow label
302 */
303
304 /* hc06 format of TC is ECN | DSCP , original one is DSCP | ECN */
305 tmp = (hdr->priority << 4) | (hdr->flow_lbl[0] >> 4);
306 tmp = ((tmp & 0x03) << 6) | (tmp >> 2);
307
308 if (((hdr->flow_lbl[0] & 0x0F) == 0) &&
309 (hdr->flow_lbl[1] == 0) && (hdr->flow_lbl[2] == 0)) {
310 /* flow label can be compressed */
311 iphc0 |= LOWPAN_IPHC_FL_C;
312 if ((hdr->priority == 0) &&
313 ((hdr->flow_lbl[0] & 0xF0) == 0)) {
314 /* compress (elide) all */
315 iphc0 |= LOWPAN_IPHC_TC_C;
316 } else {
317 /* compress only the flow label */
318 *hc06_ptr = tmp;
319 hc06_ptr += 1;
320 }
321 } else {
322 /* Flow label cannot be compressed */
323 if ((hdr->priority == 0) &&
324 ((hdr->flow_lbl[0] & 0xF0) == 0)) {
325 /* compress only traffic class */
326 iphc0 |= LOWPAN_IPHC_TC_C;
327 *hc06_ptr = (tmp & 0xc0) | (hdr->flow_lbl[0] & 0x0F);
328 memcpy(hc06_ptr + 1, &hdr->flow_lbl[1], 2);
329 hc06_ptr += 3;
330 } else {
331 /* compress nothing */
332 memcpy(hc06_ptr, &hdr, 4);
333 /* replace the top byte with new ECN | DSCP format */
334 *hc06_ptr = tmp;
335 hc06_ptr += 4;
336 }
337 }
338
339 /* NOTE: payload length is always compressed */
340
341 /* Next Header is compress if UDP */
342 if (hdr->nexthdr == UIP_PROTO_UDP)
343 iphc0 |= LOWPAN_IPHC_NH_C;
344
345/* TODO: next header compression */
346
347 if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) {
348 *hc06_ptr = hdr->nexthdr;
349 hc06_ptr += 1;
350 }
351
352 /*
353 * Hop limit
354 * if 1: compress, encoding is 01
355 * if 64: compress, encoding is 10
356 * if 255: compress, encoding is 11
357 * else do not compress
358 */
359 switch (hdr->hop_limit) {
360 case 1:
361 iphc0 |= LOWPAN_IPHC_TTL_1;
362 break;
363 case 64:
364 iphc0 |= LOWPAN_IPHC_TTL_64;
365 break;
366 case 255:
367 iphc0 |= LOWPAN_IPHC_TTL_255;
368 break;
369 default:
370 *hc06_ptr = hdr->hop_limit;
371 break;
372 }
373
374 /* source address compression */
375 if (is_addr_unspecified(&hdr->saddr)) {
376 pr_debug("(%s): source address is unspecified, setting SAC\n",
377 __func__);
378 iphc1 |= LOWPAN_IPHC_SAC;
379 /* TODO: context lookup */
380 } else if (is_addr_link_local(&hdr->saddr)) {
381 pr_debug("(%s): source address is link-local\n", __func__);
382 iphc1 |= lowpan_compress_addr_64(&hc06_ptr,
383 LOWPAN_IPHC_SAM_BIT, &hdr->saddr, saddr);
384 } else {
385 pr_debug("(%s): send the full source address\n", __func__);
386 memcpy(hc06_ptr, &hdr->saddr.s6_addr16[0], 16);
387 hc06_ptr += 16;
388 }
389
390 /* destination address compression */
391 if (is_addr_mcast(&hdr->daddr)) {
392 pr_debug("(%s): destination address is multicast", __func__);
393 iphc1 |= LOWPAN_IPHC_M;
394 if (lowpan_is_mcast_addr_compressable8(&hdr->daddr)) {
395 pr_debug("compressed to 1 octet\n");
396 iphc1 |= LOWPAN_IPHC_DAM_11;
397 /* use last byte */
398 *hc06_ptr = hdr->daddr.s6_addr[15];
399 hc06_ptr += 1;
400 } else if (lowpan_is_mcast_addr_compressable32(&hdr->daddr)) {
401 pr_debug("compressed to 4 octets\n");
402 iphc1 |= LOWPAN_IPHC_DAM_10;
403 /* second byte + the last three */
404 *hc06_ptr = hdr->daddr.s6_addr[1];
405 memcpy(hc06_ptr + 1, &hdr->daddr.s6_addr[13], 3);
406 hc06_ptr += 4;
407 } else if (lowpan_is_mcast_addr_compressable48(&hdr->daddr)) {
408 pr_debug("compressed to 6 octets\n");
409 iphc1 |= LOWPAN_IPHC_DAM_01;
410 /* second byte + the last five */
411 *hc06_ptr = hdr->daddr.s6_addr[1];
412 memcpy(hc06_ptr + 1, &hdr->daddr.s6_addr[11], 5);
413 hc06_ptr += 6;
414 } else {
415 pr_debug("using full address\n");
416 iphc1 |= LOWPAN_IPHC_DAM_00;
417 memcpy(hc06_ptr, &hdr->daddr.s6_addr[0], 16);
418 hc06_ptr += 16;
419 }
420 } else {
421 pr_debug("(%s): destination address is unicast: ", __func__);
422 /* TODO: context lookup */
423 if (is_addr_link_local(&hdr->daddr)) {
424 pr_debug("destination address is link-local\n");
425 iphc1 |= lowpan_compress_addr_64(&hc06_ptr,
426 LOWPAN_IPHC_DAM_BIT, &hdr->daddr, daddr);
427 } else {
428 pr_debug("using full address\n");
429 memcpy(hc06_ptr, &hdr->daddr.s6_addr16[0], 16);
430 hc06_ptr += 16;
431 }
432 }
433
434 /* TODO: UDP header compression */
435 /* TODO: Next Header compression */
436
437 head[0] = iphc0;
438 head[1] = iphc1;
439
440 skb_pull(skb, sizeof(struct ipv6hdr));
441 memcpy(skb_push(skb, hc06_ptr - head), head, hc06_ptr - head);
442
443 kfree(head);
444
445 lowpan_raw_dump_table(__func__, "raw skb data dump", skb->data,
446 skb->len);
447
448 /*
449 * NOTE1: I'm still unsure about the fact that compression and WPAN
450 * header are created here and not later in the xmit. So wait for
451 * an opinion of net maintainers.
452 */
453 /*
454 * NOTE2: to be absolutely correct, we must derive PANid information
455 * from MAC subif of the 'dev' and 'real_dev' network devices, but
456 * this isn't implemented in mainline yet, so currently we assign 0xff
457 */
458 {
459 /* prepare wpan address data */
460 sa.addr_type = IEEE802154_ADDR_LONG;
461 sa.pan_id = 0xff;
462
463 da.addr_type = IEEE802154_ADDR_LONG;
464 da.pan_id = 0xff;
465
466 memcpy(&(da.hwaddr), daddr, 8);
467 memcpy(&(sa.hwaddr), saddr, 8);
468
469 mac_cb(skb)->flags = IEEE802154_FC_TYPE_DATA;
470 return dev_hard_header(skb, lowpan_dev_info(dev)->real_dev,
471 type, (void *)&da, (void *)&sa, skb->len);
472 }
473}
474
475static int lowpan_skb_deliver(struct sk_buff *skb, struct ipv6hdr *hdr)
476{
477 struct sk_buff *new;
478 struct lowpan_dev_record *entry;
479 int stat = NET_RX_SUCCESS;
480
481 new = skb_copy_expand(skb, sizeof(struct ipv6hdr), skb_tailroom(skb),
482 GFP_KERNEL);
483 kfree_skb(skb);
484
485 if (NULL == new)
486 return -ENOMEM;
487
488 skb_push(new, sizeof(struct ipv6hdr));
489 skb_reset_network_header(new);
490 skb_copy_to_linear_data(new, hdr, sizeof(struct ipv6hdr));
491
492 new->protocol = htons(ETH_P_IPV6);
493 new->pkt_type = PACKET_HOST;
494
495 rcu_read_lock();
496 list_for_each_entry_rcu(entry, &lowpan_devices, list)
497 if (lowpan_dev_info(entry->ldev)->real_dev == new->dev) {
498 skb = skb_copy(new, GFP_KERNEL);
499 skb->dev = entry->ldev;
500
501 if (in_interrupt())
502 stat = netif_rx(skb);
503 else
504 stat = netif_rx_ni(skb);
505 }
506 rcu_read_unlock();
507
508 kfree_skb(new);
509
510 return stat;
511}
512
513static int
514lowpan_process_data(struct sk_buff *skb)
515{
516 struct ipv6hdr hdr;
517 u8 tmp, iphc0, iphc1, num_context = 0;
518 u8 *_saddr, *_daddr;
519 int err;
520
521 lowpan_raw_dump_table(__func__, "raw skb data dump", skb->data,
522 skb->len);
523 /* at least two bytes will be used for the encoding */
524 if (skb->len < 2)
525 goto drop;
526 iphc0 = lowpan_fetch_skb_u8(skb);
527 iphc1 = lowpan_fetch_skb_u8(skb);
528
529 _saddr = mac_cb(skb)->sa.hwaddr;
530 _daddr = mac_cb(skb)->da.hwaddr;
531
532 pr_debug("(%s): iphc0 = %02x, iphc1 = %02x\n", __func__, iphc0, iphc1);
533
534 /* another if the CID flag is set */
535 if (iphc1 & LOWPAN_IPHC_CID) {
536 pr_debug("(%s): CID flag is set, increase header with one\n",
537 __func__);
538 if (!skb->len)
539 goto drop;
540 num_context = lowpan_fetch_skb_u8(skb);
541 }
542
543 hdr.version = 6;
544
545 /* Traffic Class and Flow Label */
546 switch ((iphc0 & LOWPAN_IPHC_TF) >> 3) {
547 /*
548 * Traffic Class and FLow Label carried in-line
549 * ECN + DSCP + 4-bit Pad + Flow Label (4 bytes)
550 */
551 case 0: /* 00b */
552 if (!skb->len)
553 goto drop;
554 tmp = lowpan_fetch_skb_u8(skb);
555 memcpy(&hdr.flow_lbl, &skb->data[0], 3);
556 skb_pull(skb, 3);
557 hdr.priority = ((tmp >> 2) & 0x0f);
558 hdr.flow_lbl[0] = ((tmp >> 2) & 0x30) | (tmp << 6) |
559 (hdr.flow_lbl[0] & 0x0f);
560 break;
561 /*
562 * Traffic class carried in-line
563 * ECN + DSCP (1 byte), Flow Label is elided
564 */
565 case 1: /* 10b */
566 if (!skb->len)
567 goto drop;
568 tmp = lowpan_fetch_skb_u8(skb);
569 hdr.priority = ((tmp >> 2) & 0x0f);
570 hdr.flow_lbl[0] = ((tmp << 6) & 0xC0) | ((tmp >> 2) & 0x30);
571 hdr.flow_lbl[1] = 0;
572 hdr.flow_lbl[2] = 0;
573 break;
574 /*
575 * Flow Label carried in-line
576 * ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided
577 */
578 case 2: /* 01b */
579 if (!skb->len)
580 goto drop;
581 tmp = lowpan_fetch_skb_u8(skb);
582 hdr.flow_lbl[0] = (skb->data[0] & 0x0F) | ((tmp >> 2) & 0x30);
583 memcpy(&hdr.flow_lbl[1], &skb->data[0], 2);
584 skb_pull(skb, 2);
585 break;
586 /* Traffic Class and Flow Label are elided */
587 case 3: /* 11b */
588 hdr.priority = 0;
589 hdr.flow_lbl[0] = 0;
590 hdr.flow_lbl[1] = 0;
591 hdr.flow_lbl[2] = 0;
592 break;
593 default:
594 break;
595 }
596
597 /* Next Header */
598 if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) {
599 /* Next header is carried inline */
600 if (!skb->len)
601 goto drop;
602 hdr.nexthdr = lowpan_fetch_skb_u8(skb);
603 pr_debug("(%s): NH flag is set, next header is carried "
604 "inline: %02x\n", __func__, hdr.nexthdr);
605 }
606
607 /* Hop Limit */
608 if ((iphc0 & 0x03) != LOWPAN_IPHC_TTL_I)
609 hdr.hop_limit = lowpan_ttl_values[iphc0 & 0x03];
610 else {
611 if (!skb->len)
612 goto drop;
613 hdr.hop_limit = lowpan_fetch_skb_u8(skb);
614 }
615
616 /* Extract SAM to the tmp variable */
617 tmp = ((iphc1 & LOWPAN_IPHC_SAM) >> LOWPAN_IPHC_SAM_BIT) & 0x03;
618
619 /* Source address uncompression */
620 pr_debug("(%s): source address stateless compression\n", __func__);
621 err = lowpan_uncompress_addr(skb, &hdr.saddr, lowpan_llprefix,
622 lowpan_unc_llconf[tmp], skb->data);
623 if (err)
624 goto drop;
625
626 /* Extract DAM to the tmp variable */
627 tmp = ((iphc1 & LOWPAN_IPHC_DAM_11) >> LOWPAN_IPHC_DAM_BIT) & 0x03;
628
629 /* check for Multicast Compression */
630 if (iphc1 & LOWPAN_IPHC_M) {
631 if (iphc1 & LOWPAN_IPHC_DAC) {
632 pr_debug("(%s): destination address context-based "
633 "multicast compression\n", __func__);
634 /* TODO: implement this */
635 } else {
636 u8 prefix[] = {0xff, 0x02};
637
638 pr_debug("(%s): destination address non-context-based"
639 " multicast compression\n", __func__);
640 if (0 < tmp && tmp < 3) {
641 if (!skb->len)
642 goto drop;
643 else
644 prefix[1] = lowpan_fetch_skb_u8(skb);
645 }
646
647 err = lowpan_uncompress_addr(skb, &hdr.daddr, prefix,
648 lowpan_unc_mxconf[tmp], NULL);
649 if (err)
650 goto drop;
651 }
652 } else {
653 pr_debug("(%s): destination address stateless compression\n",
654 __func__);
655 err = lowpan_uncompress_addr(skb, &hdr.daddr, lowpan_llprefix,
656 lowpan_unc_llconf[tmp], skb->data);
657 if (err)
658 goto drop;
659 }
660
661 /* TODO: UDP header parse */
662
663 /* Not fragmented package */
664 hdr.payload_len = htons(skb->len);
665
666 pr_debug("(%s): skb headroom size = %d, data length = %d\n", __func__,
667 skb_headroom(skb), skb->len);
668
669 pr_debug("(%s): IPv6 header dump:\n\tversion = %d\n\tlength = %d\n\t"
670 "nexthdr = 0x%02x\n\thop_lim = %d\n", __func__, hdr.version,
671 ntohs(hdr.payload_len), hdr.nexthdr, hdr.hop_limit);
672
673 lowpan_raw_dump_table(__func__, "raw header dump", (u8 *)&hdr,
674 sizeof(hdr));
675 return lowpan_skb_deliver(skb, &hdr);
676drop:
677 kfree(skb);
678 return -EINVAL;
679}
680
681static int lowpan_set_address(struct net_device *dev, void *p)
682{
683 struct sockaddr *sa = p;
684
685 if (netif_running(dev))
686 return -EBUSY;
687
688 /* TODO: validate addr */
689 memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
690
691 return 0;
692}
693
694static netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *dev)
695{
696 int err = 0;
697
698 pr_debug("(%s): package xmit\n", __func__);
699
700 skb->dev = lowpan_dev_info(dev)->real_dev;
701 if (skb->dev == NULL) {
702 pr_debug("(%s) ERROR: no real wpan device found\n", __func__);
703 dev_kfree_skb(skb);
704 } else
705 err = dev_queue_xmit(skb);
706
707 return (err < 0 ? NETDEV_TX_BUSY : NETDEV_TX_OK);
708}
709
710static void lowpan_dev_free(struct net_device *dev)
711{
712 dev_put(lowpan_dev_info(dev)->real_dev);
713 free_netdev(dev);
714}
715
716static struct header_ops lowpan_header_ops = {
717 .create = lowpan_header_create,
718};
719
720static const struct net_device_ops lowpan_netdev_ops = {
721 .ndo_start_xmit = lowpan_xmit,
722 .ndo_set_mac_address = lowpan_set_address,
723};
724
725static void lowpan_setup(struct net_device *dev)
726{
727 pr_debug("(%s)\n", __func__);
728
729 dev->addr_len = IEEE802154_ADDR_LEN;
730 memset(dev->broadcast, 0xff, IEEE802154_ADDR_LEN);
731 dev->type = ARPHRD_IEEE802154;
732 dev->features = NETIF_F_NO_CSUM;
733 /* Frame Control + Sequence Number + Address fields + Security Header */
734 dev->hard_header_len = 2 + 1 + 20 + 14;
735 dev->needed_tailroom = 2; /* FCS */
736 dev->mtu = 1281;
737 dev->tx_queue_len = 0;
738 dev->flags = IFF_NOARP | IFF_BROADCAST;
739 dev->watchdog_timeo = 0;
740
741 dev->netdev_ops = &lowpan_netdev_ops;
742 dev->header_ops = &lowpan_header_ops;
743 dev->destructor = lowpan_dev_free;
744}
745
746static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[])
747{
748 pr_debug("(%s)\n", __func__);
749
750 if (tb[IFLA_ADDRESS]) {
751 if (nla_len(tb[IFLA_ADDRESS]) != IEEE802154_ADDR_LEN)
752 return -EINVAL;
753 }
754 return 0;
755}
756
757static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
758 struct packet_type *pt, struct net_device *orig_dev)
759{
760 if (!netif_running(dev))
761 goto drop;
762
763 if (dev->type != ARPHRD_IEEE802154)
764 goto drop;
765
766 /* check that it's our buffer */
767 if ((skb->data[0] & 0xe0) == 0x60)
768 lowpan_process_data(skb);
769
770 return NET_RX_SUCCESS;
771
772drop:
773 kfree_skb(skb);
774 return NET_RX_DROP;
775}
776
777static int lowpan_newlink(struct net *src_net, struct net_device *dev,
778 struct nlattr *tb[], struct nlattr *data[])
779{
780 struct net_device *real_dev;
781 struct lowpan_dev_record *entry;
782
783 pr_debug("(%s)\n", __func__);
784
785 if (!tb[IFLA_LINK])
786 return -EINVAL;
787 /* find and hold real wpan device */
788 real_dev = dev_get_by_index(src_net, nla_get_u32(tb[IFLA_LINK]));
789 if (!real_dev)
790 return -ENODEV;
791
792 lowpan_dev_info(dev)->real_dev = real_dev;
793 mutex_init(&lowpan_dev_info(dev)->dev_list_mtx);
794
795 entry = kzalloc(sizeof(struct lowpan_dev_record), GFP_KERNEL);
796 if (!entry)
797 return -ENOMEM;
798
799 entry->ldev = dev;
800
801 mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
802 INIT_LIST_HEAD(&entry->list);
803 list_add_tail(&entry->list, &lowpan_devices);
804 mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
805
806 register_netdevice(dev);
807
808 return 0;
809}
810
811static void lowpan_dellink(struct net_device *dev, struct list_head *head)
812{
813 struct lowpan_dev_info *lowpan_dev = lowpan_dev_info(dev);
814 struct net_device *real_dev = lowpan_dev->real_dev;
815 struct lowpan_dev_record *entry;
816
817 ASSERT_RTNL();
818
819 mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
820 list_for_each_entry(entry, &lowpan_devices, list)
821 if (entry->ldev == dev) {
822 list_del(&entry->list);
823 kfree(entry);
824 }
825 mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
826
827 mutex_destroy(&lowpan_dev_info(dev)->dev_list_mtx);
828
829 unregister_netdevice_queue(dev, head);
830
831 dev_put(real_dev);
832}
833
834static struct rtnl_link_ops lowpan_link_ops __read_mostly = {
835 .kind = "lowpan",
836 .priv_size = sizeof(struct lowpan_dev_info),
837 .setup = lowpan_setup,
838 .newlink = lowpan_newlink,
839 .dellink = lowpan_dellink,
840 .validate = lowpan_validate,
841};
842
843static inline int __init lowpan_netlink_init(void)
844{
845 return rtnl_link_register(&lowpan_link_ops);
846}
847
848static inline void __init lowpan_netlink_fini(void)
849{
850 rtnl_link_unregister(&lowpan_link_ops);
851}
852
853static struct packet_type lowpan_packet_type = {
854 .type = __constant_htons(ETH_P_IEEE802154),
855 .func = lowpan_rcv,
856};
857
858static int __init lowpan_init_module(void)
859{
860 int err = 0;
861
862 pr_debug("(%s)\n", __func__);
863
864 err = lowpan_netlink_init();
865 if (err < 0)
866 goto out;
867
868 dev_add_pack(&lowpan_packet_type);
869out:
870 return err;
871}
872
873static void __exit lowpan_cleanup_module(void)
874{
875 pr_debug("(%s)\n", __func__);
876
877 lowpan_netlink_fini();
878
879 dev_remove_pack(&lowpan_packet_type);
880}
881
882module_init(lowpan_init_module);
883module_exit(lowpan_cleanup_module);
884MODULE_LICENSE("GPL");
885MODULE_ALIAS_RTNL_LINK("lowpan");
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-02 16:09:47 -0500