6lowpan: Refactor packet delivery into a function
[linux-2.6.git] / net / ieee802154 / 6lowpan.c
blob1714cfab12204c04107e2201749bda42077f43e9
1 /*
2 * Copyright 2011, Siemens AG
3 * written by Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
4 */
6 /*
7 * Based on patches from Jon Smirl <jonsmirl@gmail.com>
8 * Copyright (c) 2011 Jon Smirl <jonsmirl@gmail.com>
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.
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.
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.
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.
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.
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.
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>
63 #include "6lowpan.h"
65 /* TTL uncompression values */
66 static const u8 lowpan_ttl_values[] = {0, 1, 64, 255};
68 static LIST_HEAD(lowpan_devices);
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
77 * NOTE: => the uncompress function does change 0xf to 0x10
78 * NOTE: 0x00 => no-autoconfig => unspecified
80 static const u8 lowpan_unc_llconf[] = {0x0f, 0x28, 0x22, 0x20};
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
89 static const u8 lowpan_unc_ctxconf[] = {0x00, 0x88, 0x82, 0x80};
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
98 static const u8 lowpan_unc_mxconf[] = {0x0f, 0x25, 0x23, 0x21};
100 /* Link local prefix */
101 static const u8 lowpan_llprefix[] = {0xfe, 0x80};
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 */
109 struct lowpan_dev_record {
110 struct net_device *ldev;
111 struct list_head list;
114 struct lowpan_fragment {
115 struct sk_buff *skb; /* skb to be assembled */
116 u16 length; /* length to be assemled */
117 u32 bytes_rcv; /* bytes received */
118 u16 tag; /* current fragment tag */
119 struct timer_list timer; /* assembling timer */
120 struct list_head list; /* fragments list */
123 static unsigned short fragment_tag;
124 static LIST_HEAD(lowpan_fragments);
125 static DEFINE_SPINLOCK(flist_lock);
127 static inline struct
128 lowpan_dev_info *lowpan_dev_info(const struct net_device *dev)
130 return netdev_priv(dev);
133 static inline void lowpan_address_flip(u8 *src, u8 *dest)
135 int i;
136 for (i = 0; i < IEEE802154_ADDR_LEN; i++)
137 (dest)[IEEE802154_ADDR_LEN - i - 1] = (src)[i];
140 /* list of all 6lowpan devices, uses for package delivering */
141 /* print data in line */
142 static inline void lowpan_raw_dump_inline(const char *caller, char *msg,
143 unsigned char *buf, int len)
145 #ifdef DEBUG
146 if (msg)
147 pr_debug("(%s) %s: ", caller, msg);
148 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_NONE,
149 16, 1, buf, len, false);
150 #endif /* DEBUG */
154 * print data in a table format:
156 * addr: xx xx xx xx xx xx
157 * addr: xx xx xx xx xx xx
158 * ...
160 static inline void lowpan_raw_dump_table(const char *caller, char *msg,
161 unsigned char *buf, int len)
163 #ifdef DEBUG
164 if (msg)
165 pr_debug("(%s) %s:\n", caller, msg);
166 print_hex_dump(KERN_DEBUG, "\t", DUMP_PREFIX_OFFSET,
167 16, 1, buf, len, false);
168 #endif /* DEBUG */
171 static u8
172 lowpan_compress_addr_64(u8 **hc06_ptr, u8 shift, const struct in6_addr *ipaddr,
173 const unsigned char *lladdr)
175 u8 val = 0;
177 if (is_addr_mac_addr_based(ipaddr, lladdr))
178 val = 3; /* 0-bits */
179 else if (lowpan_is_iid_16_bit_compressable(ipaddr)) {
180 /* compress IID to 16 bits xxxx::XXXX */
181 memcpy(*hc06_ptr, &ipaddr->s6_addr16[7], 2);
182 *hc06_ptr += 2;
183 val = 2; /* 16-bits */
184 } else {
185 /* do not compress IID => xxxx::IID */
186 memcpy(*hc06_ptr, &ipaddr->s6_addr16[4], 8);
187 *hc06_ptr += 8;
188 val = 1; /* 64-bits */
191 return rol8(val, shift);
194 static void
195 lowpan_uip_ds6_set_addr_iid(struct in6_addr *ipaddr, unsigned char *lladdr)
197 memcpy(&ipaddr->s6_addr[8], lladdr, IEEE802154_ADDR_LEN);
198 /* second bit-flip (Universe/Local) is done according RFC2464 */
199 ipaddr->s6_addr[8] ^= 0x02;
203 * Uncompress addresses based on a prefix and a postfix with zeroes in
204 * between. If the postfix is zero in length it will use the link address
205 * to configure the IP address (autoconf style).
206 * pref_post_count takes a byte where the first nibble specify prefix count
207 * and the second postfix count (NOTE: 15/0xf => 16 bytes copy).
209 static int
210 lowpan_uncompress_addr(struct sk_buff *skb, struct in6_addr *ipaddr,
211 u8 const *prefix, u8 pref_post_count, unsigned char *lladdr)
213 u8 prefcount = pref_post_count >> 4;
214 u8 postcount = pref_post_count & 0x0f;
216 /* full nibble 15 => 16 */
217 prefcount = (prefcount == 15 ? 16 : prefcount);
218 postcount = (postcount == 15 ? 16 : postcount);
220 if (lladdr)
221 lowpan_raw_dump_inline(__func__, "linklocal address",
222 lladdr, IEEE802154_ADDR_LEN);
223 if (prefcount > 0)
224 memcpy(ipaddr, prefix, prefcount);
226 if (prefcount + postcount < 16)
227 memset(&ipaddr->s6_addr[prefcount], 0,
228 16 - (prefcount + postcount));
230 if (postcount > 0) {
231 memcpy(&ipaddr->s6_addr[16 - postcount], skb->data, postcount);
232 skb_pull(skb, postcount);
233 } else if (prefcount > 0) {
234 if (lladdr == NULL)
235 return -EINVAL;
237 /* no IID based configuration if no prefix and no data */
238 lowpan_uip_ds6_set_addr_iid(ipaddr, lladdr);
241 pr_debug("uncompressing %d + %d => ", prefcount, postcount);
242 lowpan_raw_dump_inline(NULL, NULL, ipaddr->s6_addr, 16);
244 return 0;
247 static void
248 lowpan_compress_udp_header(u8 **hc06_ptr, struct sk_buff *skb)
250 struct udphdr *uh = udp_hdr(skb);
252 if (((uh->source & LOWPAN_NHC_UDP_4BIT_MASK) ==
253 LOWPAN_NHC_UDP_4BIT_PORT) &&
254 ((uh->dest & LOWPAN_NHC_UDP_4BIT_MASK) ==
255 LOWPAN_NHC_UDP_4BIT_PORT)) {
256 pr_debug("UDP header: both ports compression to 4 bits\n");
257 **hc06_ptr = LOWPAN_NHC_UDP_CS_P_11;
258 **(hc06_ptr + 1) = /* subtraction is faster */
259 (u8)((uh->dest - LOWPAN_NHC_UDP_4BIT_PORT) +
260 ((uh->source & LOWPAN_NHC_UDP_4BIT_PORT) << 4));
261 *hc06_ptr += 2;
262 } else if ((uh->dest & LOWPAN_NHC_UDP_8BIT_MASK) ==
263 LOWPAN_NHC_UDP_8BIT_PORT) {
264 pr_debug("UDP header: remove 8 bits of dest\n");
265 **hc06_ptr = LOWPAN_NHC_UDP_CS_P_01;
266 memcpy(*hc06_ptr + 1, &uh->source, 2);
267 **(hc06_ptr + 3) = (u8)(uh->dest - LOWPAN_NHC_UDP_8BIT_PORT);
268 *hc06_ptr += 4;
269 } else if ((uh->source & LOWPAN_NHC_UDP_8BIT_MASK) ==
270 LOWPAN_NHC_UDP_8BIT_PORT) {
271 pr_debug("UDP header: remove 8 bits of source\n");
272 **hc06_ptr = LOWPAN_NHC_UDP_CS_P_10;
273 memcpy(*hc06_ptr + 1, &uh->dest, 2);
274 **(hc06_ptr + 3) = (u8)(uh->source - LOWPAN_NHC_UDP_8BIT_PORT);
275 *hc06_ptr += 4;
276 } else {
277 pr_debug("UDP header: can't compress\n");
278 **hc06_ptr = LOWPAN_NHC_UDP_CS_P_00;
279 memcpy(*hc06_ptr + 1, &uh->source, 2);
280 memcpy(*hc06_ptr + 3, &uh->dest, 2);
281 *hc06_ptr += 5;
284 /* checksum is always inline */
285 memcpy(*hc06_ptr, &uh->check, 2);
286 *hc06_ptr += 2;
289 static inline int lowpan_fetch_skb_u8(struct sk_buff *skb, u8 *val)
291 if (unlikely(!pskb_may_pull(skb, 1)))
292 return -EINVAL;
294 *val = skb->data[0];
295 skb_pull(skb, 1);
297 return 0;
300 static inline int lowpan_fetch_skb_u16(struct sk_buff *skb, u16 *val)
302 if (unlikely(!pskb_may_pull(skb, 2)))
303 return -EINVAL;
305 *val = (skb->data[0] << 8) | skb->data[1];
306 skb_pull(skb, 2);
308 return 0;
311 static int
312 lowpan_uncompress_udp_header(struct sk_buff *skb)
314 struct udphdr *uh = udp_hdr(skb);
315 u8 tmp;
317 if (!uh)
318 goto err;
320 if (lowpan_fetch_skb_u8(skb, &tmp))
321 goto err;
323 if ((tmp & LOWPAN_NHC_UDP_MASK) == LOWPAN_NHC_UDP_ID) {
324 pr_debug("UDP header uncompression\n");
325 switch (tmp & LOWPAN_NHC_UDP_CS_P_11) {
326 case LOWPAN_NHC_UDP_CS_P_00:
327 memcpy(&uh->source, &skb->data[0], 2);
328 memcpy(&uh->dest, &skb->data[2], 2);
329 skb_pull(skb, 4);
330 break;
331 case LOWPAN_NHC_UDP_CS_P_01:
332 memcpy(&uh->source, &skb->data[0], 2);
333 uh->dest =
334 skb->data[2] + LOWPAN_NHC_UDP_8BIT_PORT;
335 skb_pull(skb, 3);
336 break;
337 case LOWPAN_NHC_UDP_CS_P_10:
338 uh->source = skb->data[0] + LOWPAN_NHC_UDP_8BIT_PORT;
339 memcpy(&uh->dest, &skb->data[1], 2);
340 skb_pull(skb, 3);
341 break;
342 case LOWPAN_NHC_UDP_CS_P_11:
343 uh->source =
344 LOWPAN_NHC_UDP_4BIT_PORT + (skb->data[0] >> 4);
345 uh->dest =
346 LOWPAN_NHC_UDP_4BIT_PORT + (skb->data[0] & 0x0f);
347 skb_pull(skb, 1);
348 break;
349 default:
350 pr_debug("ERROR: unknown UDP format\n");
351 goto err;
352 break;
355 pr_debug("uncompressed UDP ports: src = %d, dst = %d\n",
356 uh->source, uh->dest);
358 /* copy checksum */
359 memcpy(&uh->check, &skb->data[0], 2);
360 skb_pull(skb, 2);
361 } else {
362 pr_debug("ERROR: unsupported NH format\n");
363 goto err;
366 return 0;
367 err:
368 return -EINVAL;
371 static int lowpan_header_create(struct sk_buff *skb,
372 struct net_device *dev,
373 unsigned short type, const void *_daddr,
374 const void *_saddr, unsigned int len)
376 u8 tmp, iphc0, iphc1, *hc06_ptr;
377 struct ipv6hdr *hdr;
378 const u8 *saddr = _saddr;
379 const u8 *daddr = _daddr;
380 u8 *head;
381 struct ieee802154_addr sa, da;
383 if (type != ETH_P_IPV6)
384 return 0;
385 /* TODO:
386 * if this package isn't ipv6 one, where should it be routed?
388 head = kzalloc(100, GFP_KERNEL);
389 if (head == NULL)
390 return -ENOMEM;
392 hdr = ipv6_hdr(skb);
393 hc06_ptr = head + 2;
395 pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength = %d\n"
396 "\tnexthdr = 0x%02x\n\thop_lim = %d\n", hdr->version,
397 ntohs(hdr->payload_len), hdr->nexthdr, hdr->hop_limit);
399 lowpan_raw_dump_table(__func__, "raw skb network header dump",
400 skb_network_header(skb), sizeof(struct ipv6hdr));
402 if (!saddr)
403 saddr = dev->dev_addr;
405 lowpan_raw_dump_inline(__func__, "saddr", (unsigned char *)saddr, 8);
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
413 iphc0 = LOWPAN_DISPATCH_IPHC;
414 iphc1 = 0;
416 /* TODO: context lookup */
418 lowpan_raw_dump_inline(__func__, "daddr", (unsigned char *)daddr, 8);
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
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);
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;
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;
462 /* NOTE: payload length is always compressed */
464 /* Next Header is compress if UDP */
465 if (hdr->nexthdr == UIP_PROTO_UDP)
466 iphc0 |= LOWPAN_IPHC_NH_C;
468 if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) {
469 *hc06_ptr = hdr->nexthdr;
470 hc06_ptr += 1;
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
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 hc06_ptr += 1;
493 break;
496 /* source address compression */
497 if (is_addr_unspecified(&hdr->saddr)) {
498 pr_debug("source address is unspecified, setting SAC\n");
499 iphc1 |= LOWPAN_IPHC_SAC;
500 /* TODO: context lookup */
501 } else if (is_addr_link_local(&hdr->saddr)) {
502 pr_debug("source address is link-local\n");
503 iphc1 |= lowpan_compress_addr_64(&hc06_ptr,
504 LOWPAN_IPHC_SAM_BIT, &hdr->saddr, saddr);
505 } else {
506 pr_debug("send the full source address\n");
507 memcpy(hc06_ptr, &hdr->saddr.s6_addr16[0], 16);
508 hc06_ptr += 16;
511 /* destination address compression */
512 if (is_addr_mcast(&hdr->daddr)) {
513 pr_debug("destination address is multicast: ");
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;
541 } else {
542 /* TODO: context lookup */
543 if (is_addr_link_local(&hdr->daddr)) {
544 pr_debug("dest address is unicast and link-local\n");
545 iphc1 |= lowpan_compress_addr_64(&hc06_ptr,
546 LOWPAN_IPHC_DAM_BIT, &hdr->daddr, daddr);
547 } else {
548 pr_debug("dest address is unicast: using full one\n");
549 memcpy(hc06_ptr, &hdr->daddr.s6_addr16[0], 16);
550 hc06_ptr += 16;
554 /* UDP header compression */
555 if (hdr->nexthdr == UIP_PROTO_UDP)
556 lowpan_compress_udp_header(&hc06_ptr, skb);
558 head[0] = iphc0;
559 head[1] = iphc1;
561 skb_pull(skb, sizeof(struct ipv6hdr));
562 memcpy(skb_push(skb, hc06_ptr - head), head, hc06_ptr - head);
564 kfree(head);
566 lowpan_raw_dump_table(__func__, "raw skb data dump", skb->data,
567 skb->len);
570 * NOTE1: I'm still unsure about the fact that compression and WPAN
571 * header are created here and not later in the xmit. So wait for
572 * an opinion of net maintainers.
575 * NOTE2: to be absolutely correct, we must derive PANid information
576 * from MAC subif of the 'dev' and 'real_dev' network devices, but
577 * this isn't implemented in mainline yet, so currently we assign 0xff
580 /* prepare wpan address data */
581 sa.addr_type = IEEE802154_ADDR_LONG;
582 sa.pan_id = 0xff;
584 da.addr_type = IEEE802154_ADDR_LONG;
585 da.pan_id = 0xff;
587 memcpy(&(da.hwaddr), daddr, 8);
588 memcpy(&(sa.hwaddr), saddr, 8);
590 mac_cb(skb)->flags = IEEE802154_FC_TYPE_DATA;
592 return dev_hard_header(skb, lowpan_dev_info(dev)->real_dev,
593 type, (void *)&da, (void *)&sa, skb->len);
597 static int lowpan_give_skb_to_devices(struct sk_buff *skb)
599 struct lowpan_dev_record *entry;
600 struct sk_buff *skb_cp;
601 int stat = NET_RX_SUCCESS;
603 rcu_read_lock();
604 list_for_each_entry_rcu(entry, &lowpan_devices, list)
605 if (lowpan_dev_info(entry->ldev)->real_dev == skb->dev) {
606 skb_cp = skb_copy(skb, GFP_ATOMIC);
607 if (!skb_cp) {
608 stat = -ENOMEM;
609 break;
612 skb_cp->dev = entry->ldev;
613 stat = netif_rx(skb_cp);
615 rcu_read_unlock();
617 return stat;
620 static int lowpan_skb_deliver(struct sk_buff *skb, struct ipv6hdr *hdr)
622 struct sk_buff *new;
623 int stat = NET_RX_SUCCESS;
625 new = skb_copy_expand(skb, sizeof(struct ipv6hdr), skb_tailroom(skb),
626 GFP_ATOMIC);
627 kfree_skb(skb);
629 if (!new)
630 return -ENOMEM;
632 skb_push(new, sizeof(struct ipv6hdr));
633 skb_reset_network_header(new);
634 skb_copy_to_linear_data(new, hdr, sizeof(struct ipv6hdr));
636 new->protocol = htons(ETH_P_IPV6);
637 new->pkt_type = PACKET_HOST;
639 stat = lowpan_give_skb_to_devices(new);
641 kfree_skb(new);
643 return stat;
646 static void lowpan_fragment_timer_expired(unsigned long entry_addr)
648 struct lowpan_fragment *entry = (struct lowpan_fragment *)entry_addr;
650 pr_debug("timer expired for frame with tag %d\n", entry->tag);
652 list_del(&entry->list);
653 dev_kfree_skb(entry->skb);
654 kfree(entry);
657 static struct lowpan_fragment *
658 lowpan_alloc_new_frame(struct sk_buff *skb, u8 len, u16 tag)
660 struct lowpan_fragment *frame;
662 frame = kzalloc(sizeof(struct lowpan_fragment),
663 GFP_ATOMIC);
664 if (!frame)
665 goto frame_err;
667 INIT_LIST_HEAD(&frame->list);
669 frame->length = len;
670 frame->tag = tag;
672 /* allocate buffer for frame assembling */
673 frame->skb = netdev_alloc_skb_ip_align(skb->dev, frame->length +
674 sizeof(struct ipv6hdr));
676 if (!frame->skb)
677 goto skb_err;
679 frame->skb->priority = skb->priority;
680 frame->skb->dev = skb->dev;
682 /* reserve headroom for uncompressed ipv6 header */
683 skb_reserve(frame->skb, sizeof(struct ipv6hdr));
684 skb_put(frame->skb, frame->length);
686 init_timer(&frame->timer);
687 /* time out is the same as for ipv6 - 60 sec */
688 frame->timer.expires = jiffies + LOWPAN_FRAG_TIMEOUT;
689 frame->timer.data = (unsigned long)frame;
690 frame->timer.function = lowpan_fragment_timer_expired;
692 add_timer(&frame->timer);
694 list_add_tail(&frame->list, &lowpan_fragments);
696 return frame;
698 skb_err:
699 kfree(frame);
700 frame_err:
701 return NULL;
704 static int
705 lowpan_process_data(struct sk_buff *skb)
707 struct ipv6hdr hdr;
708 u8 tmp, iphc0, iphc1, num_context = 0;
709 u8 *_saddr, *_daddr;
710 int err;
712 lowpan_raw_dump_table(__func__, "raw skb data dump", skb->data,
713 skb->len);
714 /* at least two bytes will be used for the encoding */
715 if (skb->len < 2)
716 goto drop;
718 if (lowpan_fetch_skb_u8(skb, &iphc0))
719 goto drop;
721 /* fragments assembling */
722 switch (iphc0 & LOWPAN_DISPATCH_MASK) {
723 case LOWPAN_DISPATCH_FRAG1:
724 case LOWPAN_DISPATCH_FRAGN:
726 struct lowpan_fragment *frame;
727 /* slen stores the rightmost 8 bits of the 11 bits length */
728 u8 slen, offset;
729 u16 len, tag;
730 bool found = false;
732 if (lowpan_fetch_skb_u8(skb, &slen) || /* frame length */
733 lowpan_fetch_skb_u16(skb, &tag)) /* fragment tag */
734 goto drop;
736 /* adds the 3 MSB to the 8 LSB to retrieve the 11 bits length */
737 len = ((iphc0 & 7) << 8) | slen;
740 * check if frame assembling with the same tag is
741 * already in progress
743 spin_lock_bh(&flist_lock);
745 list_for_each_entry(frame, &lowpan_fragments, list)
746 if (frame->tag == tag) {
747 found = true;
748 break;
751 /* alloc new frame structure */
752 if (!found) {
753 frame = lowpan_alloc_new_frame(skb, len, tag);
754 if (!frame)
755 goto unlock_and_drop;
758 if ((iphc0 & LOWPAN_DISPATCH_MASK) == LOWPAN_DISPATCH_FRAG1)
759 goto unlock_and_drop;
761 if (lowpan_fetch_skb_u8(skb, &offset)) /* fetch offset */
762 goto unlock_and_drop;
764 /* if payload fits buffer, copy it */
765 if (likely((offset * 8 + skb->len) <= frame->length))
766 skb_copy_to_linear_data_offset(frame->skb, offset * 8,
767 skb->data, skb->len);
768 else
769 goto unlock_and_drop;
771 frame->bytes_rcv += skb->len;
773 /* frame assembling complete */
774 if ((frame->bytes_rcv == frame->length) &&
775 frame->timer.expires > jiffies) {
776 /* if timer haven't expired - first of all delete it */
777 del_timer_sync(&frame->timer);
778 list_del(&frame->list);
779 spin_unlock_bh(&flist_lock);
781 dev_kfree_skb(skb);
782 skb = frame->skb;
783 kfree(frame);
785 if (lowpan_fetch_skb_u8(skb, &iphc0))
786 goto drop;
788 break;
790 spin_unlock_bh(&flist_lock);
792 return kfree_skb(skb), 0;
794 default:
795 break;
798 if (lowpan_fetch_skb_u8(skb, &iphc1))
799 goto drop;
801 _saddr = mac_cb(skb)->sa.hwaddr;
802 _daddr = mac_cb(skb)->da.hwaddr;
804 pr_debug("iphc0 = %02x, iphc1 = %02x\n", iphc0, iphc1);
806 /* another if the CID flag is set */
807 if (iphc1 & LOWPAN_IPHC_CID) {
808 pr_debug("CID flag is set, increase header with one\n");
809 if (lowpan_fetch_skb_u8(skb, &num_context))
810 goto drop;
813 hdr.version = 6;
815 /* Traffic Class and Flow Label */
816 switch ((iphc0 & LOWPAN_IPHC_TF) >> 3) {
818 * Traffic Class and FLow Label carried in-line
819 * ECN + DSCP + 4-bit Pad + Flow Label (4 bytes)
821 case 0: /* 00b */
822 if (lowpan_fetch_skb_u8(skb, &tmp))
823 goto drop;
825 memcpy(&hdr.flow_lbl, &skb->data[0], 3);
826 skb_pull(skb, 3);
827 hdr.priority = ((tmp >> 2) & 0x0f);
828 hdr.flow_lbl[0] = ((tmp >> 2) & 0x30) | (tmp << 6) |
829 (hdr.flow_lbl[0] & 0x0f);
830 break;
832 * Traffic class carried in-line
833 * ECN + DSCP (1 byte), Flow Label is elided
835 case 1: /* 10b */
836 if (lowpan_fetch_skb_u8(skb, &tmp))
837 goto drop;
839 hdr.priority = ((tmp >> 2) & 0x0f);
840 hdr.flow_lbl[0] = ((tmp << 6) & 0xC0) | ((tmp >> 2) & 0x30);
841 hdr.flow_lbl[1] = 0;
842 hdr.flow_lbl[2] = 0;
843 break;
845 * Flow Label carried in-line
846 * ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided
848 case 2: /* 01b */
849 if (lowpan_fetch_skb_u8(skb, &tmp))
850 goto drop;
852 hdr.flow_lbl[0] = (skb->data[0] & 0x0F) | ((tmp >> 2) & 0x30);
853 memcpy(&hdr.flow_lbl[1], &skb->data[0], 2);
854 skb_pull(skb, 2);
855 break;
856 /* Traffic Class and Flow Label are elided */
857 case 3: /* 11b */
858 hdr.priority = 0;
859 hdr.flow_lbl[0] = 0;
860 hdr.flow_lbl[1] = 0;
861 hdr.flow_lbl[2] = 0;
862 break;
863 default:
864 break;
867 /* Next Header */
868 if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) {
869 /* Next header is carried inline */
870 if (lowpan_fetch_skb_u8(skb, &(hdr.nexthdr)))
871 goto drop;
873 pr_debug("NH flag is set, next header carried inline: %02x\n",
874 hdr.nexthdr);
877 /* Hop Limit */
878 if ((iphc0 & 0x03) != LOWPAN_IPHC_TTL_I)
879 hdr.hop_limit = lowpan_ttl_values[iphc0 & 0x03];
880 else {
881 if (lowpan_fetch_skb_u8(skb, &(hdr.hop_limit)))
882 goto drop;
885 /* Extract SAM to the tmp variable */
886 tmp = ((iphc1 & LOWPAN_IPHC_SAM) >> LOWPAN_IPHC_SAM_BIT) & 0x03;
888 /* Source address uncompression */
889 pr_debug("source address stateless compression\n");
890 err = lowpan_uncompress_addr(skb, &hdr.saddr, lowpan_llprefix,
891 lowpan_unc_llconf[tmp], skb->data);
892 if (err)
893 goto drop;
895 /* Extract DAM to the tmp variable */
896 tmp = ((iphc1 & LOWPAN_IPHC_DAM_11) >> LOWPAN_IPHC_DAM_BIT) & 0x03;
898 /* check for Multicast Compression */
899 if (iphc1 & LOWPAN_IPHC_M) {
900 if (iphc1 & LOWPAN_IPHC_DAC) {
901 pr_debug("dest: context-based mcast compression\n");
902 /* TODO: implement this */
903 } else {
904 u8 prefix[] = {0xff, 0x02};
906 pr_debug("dest: non context-based mcast compression\n");
907 if (0 < tmp && tmp < 3) {
908 if (lowpan_fetch_skb_u8(skb, &prefix[1]))
909 goto drop;
912 err = lowpan_uncompress_addr(skb, &hdr.daddr, prefix,
913 lowpan_unc_mxconf[tmp], NULL);
914 if (err)
915 goto drop;
917 } else {
918 pr_debug("dest: stateless compression\n");
919 err = lowpan_uncompress_addr(skb, &hdr.daddr, lowpan_llprefix,
920 lowpan_unc_llconf[tmp], skb->data);
921 if (err)
922 goto drop;
925 /* UDP data uncompression */
926 if (iphc0 & LOWPAN_IPHC_NH_C)
927 if (lowpan_uncompress_udp_header(skb))
928 goto drop;
930 /* Not fragmented package */
931 hdr.payload_len = htons(skb->len);
933 pr_debug("skb headroom size = %d, data length = %d\n",
934 skb_headroom(skb), skb->len);
936 pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength = %d\n\t"
937 "nexthdr = 0x%02x\n\thop_lim = %d\n", hdr.version,
938 ntohs(hdr.payload_len), hdr.nexthdr, hdr.hop_limit);
940 lowpan_raw_dump_table(__func__, "raw header dump", (u8 *)&hdr,
941 sizeof(hdr));
942 return lowpan_skb_deliver(skb, &hdr);
944 unlock_and_drop:
945 spin_unlock_bh(&flist_lock);
946 drop:
947 kfree_skb(skb);
948 return -EINVAL;
951 static int lowpan_set_address(struct net_device *dev, void *p)
953 struct sockaddr *sa = p;
955 if (netif_running(dev))
956 return -EBUSY;
958 /* TODO: validate addr */
959 memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
961 return 0;
964 static int lowpan_get_mac_header_length(struct sk_buff *skb)
967 * Currently long addressing mode is supported only, so the overall
968 * header size is 21:
969 * FC SeqNum DPAN DA SA Sec
970 * 2 + 1 + 2 + 8 + 8 + 0 = 21
972 return 21;
975 static int
976 lowpan_fragment_xmit(struct sk_buff *skb, u8 *head,
977 int mlen, int plen, int offset)
979 struct sk_buff *frag;
980 int hlen, ret;
982 /* if payload length is zero, therefore it's a first fragment */
983 hlen = (plen == 0 ? LOWPAN_FRAG1_HEAD_SIZE : LOWPAN_FRAGN_HEAD_SIZE);
985 lowpan_raw_dump_inline(__func__, "6lowpan fragment header", head, hlen);
987 frag = dev_alloc_skb(hlen + mlen + plen + IEEE802154_MFR_SIZE);
988 if (!frag)
989 return -ENOMEM;
991 frag->priority = skb->priority;
992 frag->dev = skb->dev;
994 /* copy header, MFR and payload */
995 memcpy(skb_put(frag, mlen), skb->data, mlen);
996 memcpy(skb_put(frag, hlen), head, hlen);
998 if (plen)
999 skb_copy_from_linear_data_offset(skb, offset + mlen,
1000 skb_put(frag, plen), plen);
1002 lowpan_raw_dump_table(__func__, " raw fragment dump", frag->data,
1003 frag->len);
1005 ret = dev_queue_xmit(frag);
1007 return ret;
1010 static int
1011 lowpan_skb_fragmentation(struct sk_buff *skb)
1013 int err, header_length, payload_length, tag, offset = 0;
1014 u8 head[5];
1016 header_length = lowpan_get_mac_header_length(skb);
1017 payload_length = skb->len - header_length;
1018 tag = fragment_tag++;
1020 /* first fragment header */
1021 head[0] = LOWPAN_DISPATCH_FRAG1 | ((payload_length >> 8) & 0x7);
1022 head[1] = payload_length & 0xff;
1023 head[2] = tag >> 8;
1024 head[3] = tag & 0xff;
1026 err = lowpan_fragment_xmit(skb, head, header_length, 0, 0);
1028 /* next fragment header */
1029 head[0] &= ~LOWPAN_DISPATCH_FRAG1;
1030 head[0] |= LOWPAN_DISPATCH_FRAGN;
1032 while ((payload_length - offset > 0) && (err >= 0)) {
1033 int len = LOWPAN_FRAG_SIZE;
1035 head[4] = offset / 8;
1037 if (payload_length - offset < len)
1038 len = payload_length - offset;
1040 err = lowpan_fragment_xmit(skb, head, header_length,
1041 len, offset);
1042 offset += len;
1045 return err;
1048 static netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *dev)
1050 int err = -1;
1052 pr_debug("package xmit\n");
1054 skb->dev = lowpan_dev_info(dev)->real_dev;
1055 if (skb->dev == NULL) {
1056 pr_debug("ERROR: no real wpan device found\n");
1057 goto error;
1060 /* Send directly if less than the MTU minus the 2 checksum bytes. */
1061 if (skb->len <= IEEE802154_MTU - IEEE802154_MFR_SIZE) {
1062 err = dev_queue_xmit(skb);
1063 goto out;
1066 pr_debug("frame is too big, fragmentation is needed\n");
1067 err = lowpan_skb_fragmentation(skb);
1068 error:
1069 dev_kfree_skb(skb);
1070 out:
1071 if (err < 0)
1072 pr_debug("ERROR: xmit failed\n");
1074 return (err < 0 ? NETDEV_TX_BUSY : NETDEV_TX_OK);
1077 static struct wpan_phy *lowpan_get_phy(const struct net_device *dev)
1079 struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
1080 return ieee802154_mlme_ops(real_dev)->get_phy(real_dev);
1083 static u16 lowpan_get_pan_id(const struct net_device *dev)
1085 struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
1086 return ieee802154_mlme_ops(real_dev)->get_pan_id(real_dev);
1089 static u16 lowpan_get_short_addr(const struct net_device *dev)
1091 struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
1092 return ieee802154_mlme_ops(real_dev)->get_short_addr(real_dev);
1095 static struct header_ops lowpan_header_ops = {
1096 .create = lowpan_header_create,
1099 static const struct net_device_ops lowpan_netdev_ops = {
1100 .ndo_start_xmit = lowpan_xmit,
1101 .ndo_set_mac_address = lowpan_set_address,
1104 static struct ieee802154_mlme_ops lowpan_mlme = {
1105 .get_pan_id = lowpan_get_pan_id,
1106 .get_phy = lowpan_get_phy,
1107 .get_short_addr = lowpan_get_short_addr,
1110 static void lowpan_setup(struct net_device *dev)
1112 dev->addr_len = IEEE802154_ADDR_LEN;
1113 memset(dev->broadcast, 0xff, IEEE802154_ADDR_LEN);
1114 dev->type = ARPHRD_IEEE802154;
1115 /* Frame Control + Sequence Number + Address fields + Security Header */
1116 dev->hard_header_len = 2 + 1 + 20 + 14;
1117 dev->needed_tailroom = 2; /* FCS */
1118 dev->mtu = 1281;
1119 dev->tx_queue_len = 0;
1120 dev->flags = IFF_BROADCAST | IFF_MULTICAST;
1121 dev->watchdog_timeo = 0;
1123 dev->netdev_ops = &lowpan_netdev_ops;
1124 dev->header_ops = &lowpan_header_ops;
1125 dev->ml_priv = &lowpan_mlme;
1126 dev->destructor = free_netdev;
1129 static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[])
1131 if (tb[IFLA_ADDRESS]) {
1132 if (nla_len(tb[IFLA_ADDRESS]) != IEEE802154_ADDR_LEN)
1133 return -EINVAL;
1135 return 0;
1138 static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
1139 struct packet_type *pt, struct net_device *orig_dev)
1141 struct sk_buff *local_skb;
1143 if (!netif_running(dev))
1144 goto drop;
1146 if (dev->type != ARPHRD_IEEE802154)
1147 goto drop;
1149 /* check that it's our buffer */
1150 switch (skb->data[0] & 0xe0) {
1151 case LOWPAN_DISPATCH_IPHC: /* ipv6 datagram */
1152 case LOWPAN_DISPATCH_FRAG1: /* first fragment header */
1153 case LOWPAN_DISPATCH_FRAGN: /* next fragments headers */
1154 local_skb = skb_clone(skb, GFP_ATOMIC);
1155 if (!local_skb)
1156 goto drop;
1157 lowpan_process_data(local_skb);
1159 kfree_skb(skb);
1160 break;
1161 default:
1162 break;
1165 return NET_RX_SUCCESS;
1167 drop:
1168 kfree_skb(skb);
1169 return NET_RX_DROP;
1172 static int lowpan_newlink(struct net *src_net, struct net_device *dev,
1173 struct nlattr *tb[], struct nlattr *data[])
1175 struct net_device *real_dev;
1176 struct lowpan_dev_record *entry;
1178 pr_debug("adding new link\n");
1180 if (!tb[IFLA_LINK])
1181 return -EINVAL;
1182 /* find and hold real wpan device */
1183 real_dev = dev_get_by_index(src_net, nla_get_u32(tb[IFLA_LINK]));
1184 if (!real_dev)
1185 return -ENODEV;
1187 lowpan_dev_info(dev)->real_dev = real_dev;
1188 mutex_init(&lowpan_dev_info(dev)->dev_list_mtx);
1190 entry = kzalloc(sizeof(struct lowpan_dev_record), GFP_KERNEL);
1191 if (!entry) {
1192 dev_put(real_dev);
1193 lowpan_dev_info(dev)->real_dev = NULL;
1194 return -ENOMEM;
1197 entry->ldev = dev;
1199 mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
1200 INIT_LIST_HEAD(&entry->list);
1201 list_add_tail(&entry->list, &lowpan_devices);
1202 mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
1204 register_netdevice(dev);
1206 return 0;
1209 static void lowpan_dellink(struct net_device *dev, struct list_head *head)
1211 struct lowpan_dev_info *lowpan_dev = lowpan_dev_info(dev);
1212 struct net_device *real_dev = lowpan_dev->real_dev;
1213 struct lowpan_dev_record *entry, *tmp;
1215 ASSERT_RTNL();
1217 mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
1218 list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) {
1219 if (entry->ldev == dev) {
1220 list_del(&entry->list);
1221 kfree(entry);
1224 mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
1226 mutex_destroy(&lowpan_dev_info(dev)->dev_list_mtx);
1228 unregister_netdevice_queue(dev, head);
1230 dev_put(real_dev);
1233 static struct rtnl_link_ops lowpan_link_ops __read_mostly = {
1234 .kind = "lowpan",
1235 .priv_size = sizeof(struct lowpan_dev_info),
1236 .setup = lowpan_setup,
1237 .newlink = lowpan_newlink,
1238 .dellink = lowpan_dellink,
1239 .validate = lowpan_validate,
1242 static inline int __init lowpan_netlink_init(void)
1244 return rtnl_link_register(&lowpan_link_ops);
1247 static inline void __init lowpan_netlink_fini(void)
1249 rtnl_link_unregister(&lowpan_link_ops);
1252 static int lowpan_device_event(struct notifier_block *unused,
1253 unsigned long event,
1254 void *ptr)
1256 struct net_device *dev = ptr;
1257 LIST_HEAD(del_list);
1258 struct lowpan_dev_record *entry, *tmp;
1260 if (dev->type != ARPHRD_IEEE802154)
1261 goto out;
1263 if (event == NETDEV_UNREGISTER) {
1264 list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) {
1265 if (lowpan_dev_info(entry->ldev)->real_dev == dev)
1266 lowpan_dellink(entry->ldev, &del_list);
1269 unregister_netdevice_many(&del_list);
1272 out:
1273 return NOTIFY_DONE;
1276 static struct notifier_block lowpan_dev_notifier = {
1277 .notifier_call = lowpan_device_event,
1280 static struct packet_type lowpan_packet_type = {
1281 .type = __constant_htons(ETH_P_IEEE802154),
1282 .func = lowpan_rcv,
1285 static int __init lowpan_init_module(void)
1287 int err = 0;
1289 err = lowpan_netlink_init();
1290 if (err < 0)
1291 goto out;
1293 dev_add_pack(&lowpan_packet_type);
1295 err = register_netdevice_notifier(&lowpan_dev_notifier);
1296 if (err < 0) {
1297 dev_remove_pack(&lowpan_packet_type);
1298 lowpan_netlink_fini();
1300 out:
1301 return err;
1304 static void __exit lowpan_cleanup_module(void)
1306 struct lowpan_fragment *frame, *tframe;
1308 lowpan_netlink_fini();
1310 dev_remove_pack(&lowpan_packet_type);
1312 unregister_netdevice_notifier(&lowpan_dev_notifier);
1314 /* Now 6lowpan packet_type is removed, so no new fragments are
1315 * expected on RX, therefore that's the time to clean incomplete
1316 * fragments.
1318 spin_lock_bh(&flist_lock);
1319 list_for_each_entry_safe(frame, tframe, &lowpan_fragments, list) {
1320 del_timer_sync(&frame->timer);
1321 list_del(&frame->list);
1322 dev_kfree_skb(frame->skb);
1323 kfree(frame);
1325 spin_unlock_bh(&flist_lock);
1328 module_init(lowpan_init_module);
1329 module_exit(lowpan_cleanup_module);
1330 MODULE_LICENSE("GPL");
1331 MODULE_ALIAS_RTNL_LINK("lowpan");