2 * Copyright 2011, Siemens AG
3 * written by Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
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
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
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>
65 static LIST_HEAD(lowpan_devices);
67 /* private device info */
68 struct lowpan_dev_info {
69 struct net_device *real_dev; /* real WPAN device ptr */
70 struct mutex dev_list_mtx; /* mutex for list ops */
71 unsigned short fragment_tag;
74 struct lowpan_dev_record {
75 struct net_device *ldev;
76 struct list_head list;
79 struct lowpan_fragment {
80 struct sk_buff *skb; /* skb to be assembled */
81 u16 length; /* length to be assemled */
82 u32 bytes_rcv; /* bytes received */
83 u16 tag; /* current fragment tag */
84 struct timer_list timer; /* assembling timer */
85 struct list_head list; /* fragments list */
88 static LIST_HEAD(lowpan_fragments);
89 static DEFINE_SPINLOCK(flist_lock);
92 lowpan_dev_info *lowpan_dev_info(const struct net_device *dev)
94 return netdev_priv(dev);
97 static inline void lowpan_address_flip(u8 *src, u8 *dest)
100 for (i = 0; i < IEEE802154_ADDR_LEN; i++)
101 (dest)[IEEE802154_ADDR_LEN - i - 1] = (src)[i];
104 static int lowpan_header_create(struct sk_buff *skb,
105 struct net_device *dev,
106 unsigned short type, const void *_daddr,
107 const void *_saddr, unsigned int len)
110 const u8 *saddr = _saddr;
111 const u8 *daddr = _daddr;
112 struct ieee802154_addr sa, da;
115 * if this package isn't ipv6 one, where should it be routed?
117 if (type != ETH_P_IPV6)
123 saddr = dev->dev_addr;
125 raw_dump_inline(__func__, "saddr", (unsigned char *)saddr, 8);
126 raw_dump_inline(__func__, "daddr", (unsigned char *)daddr, 8);
128 lowpan_header_compress(skb, dev, type, daddr, saddr, len);
131 * NOTE1: I'm still unsure about the fact that compression and WPAN
132 * header are created here and not later in the xmit. So wait for
133 * an opinion of net maintainers.
136 * NOTE2: to be absolutely correct, we must derive PANid information
137 * from MAC subif of the 'dev' and 'real_dev' network devices, but
138 * this isn't implemented in mainline yet, so currently we assign 0xff
140 mac_cb(skb)->flags = IEEE802154_FC_TYPE_DATA;
141 mac_cb(skb)->seq = ieee802154_mlme_ops(dev)->get_dsn(dev);
143 /* prepare wpan address data */
144 sa.addr_type = IEEE802154_ADDR_LONG;
145 sa.pan_id = ieee802154_mlme_ops(dev)->get_pan_id(dev);
147 memcpy(&(sa.hwaddr), saddr, 8);
148 /* intra-PAN communications */
149 da.pan_id = ieee802154_mlme_ops(dev)->get_pan_id(dev);
152 * if the destination address is the broadcast address, use the
153 * corresponding short address
155 if (lowpan_is_addr_broadcast(daddr)) {
156 da.addr_type = IEEE802154_ADDR_SHORT;
157 da.short_addr = IEEE802154_ADDR_BROADCAST;
159 da.addr_type = IEEE802154_ADDR_LONG;
160 memcpy(&(da.hwaddr), daddr, IEEE802154_ADDR_LEN);
162 /* request acknowledgment */
163 mac_cb(skb)->flags |= MAC_CB_FLAG_ACKREQ;
166 return dev_hard_header(skb, lowpan_dev_info(dev)->real_dev,
167 type, (void *)&da, (void *)&sa, skb->len);
170 static int lowpan_give_skb_to_devices(struct sk_buff *skb,
171 struct net_device *dev)
173 struct lowpan_dev_record *entry;
174 struct sk_buff *skb_cp;
175 int stat = NET_RX_SUCCESS;
178 list_for_each_entry_rcu(entry, &lowpan_devices, list)
179 if (lowpan_dev_info(entry->ldev)->real_dev == skb->dev) {
180 skb_cp = skb_copy(skb, GFP_ATOMIC);
186 skb_cp->dev = entry->ldev;
187 stat = netif_rx(skb_cp);
194 static void lowpan_fragment_timer_expired(unsigned long entry_addr)
196 struct lowpan_fragment *entry = (struct lowpan_fragment *)entry_addr;
198 pr_debug("timer expired for frame with tag %d\n", entry->tag);
200 list_del(&entry->list);
201 dev_kfree_skb(entry->skb);
205 static struct lowpan_fragment *
206 lowpan_alloc_new_frame(struct sk_buff *skb, u16 len, u16 tag)
208 struct lowpan_fragment *frame;
210 frame = kzalloc(sizeof(struct lowpan_fragment),
215 INIT_LIST_HEAD(&frame->list);
220 /* allocate buffer for frame assembling */
221 frame->skb = netdev_alloc_skb_ip_align(skb->dev, frame->length +
222 sizeof(struct ipv6hdr));
227 frame->skb->priority = skb->priority;
229 /* reserve headroom for uncompressed ipv6 header */
230 skb_reserve(frame->skb, sizeof(struct ipv6hdr));
231 skb_put(frame->skb, frame->length);
233 /* copy the first control block to keep a
234 * trace of the link-layer addresses in case
235 * of a link-local compressed address
237 memcpy(frame->skb->cb, skb->cb, sizeof(skb->cb));
239 init_timer(&frame->timer);
240 /* time out is the same as for ipv6 - 60 sec */
241 frame->timer.expires = jiffies + LOWPAN_FRAG_TIMEOUT;
242 frame->timer.data = (unsigned long)frame;
243 frame->timer.function = lowpan_fragment_timer_expired;
245 add_timer(&frame->timer);
247 list_add_tail(&frame->list, &lowpan_fragments);
257 static int process_data(struct sk_buff *skb)
260 const struct ieee802154_addr *_saddr, *_daddr;
262 raw_dump_table(__func__, "raw skb data dump", skb->data, skb->len);
263 /* at least two bytes will be used for the encoding */
267 if (lowpan_fetch_skb_u8(skb, &iphc0))
270 /* fragments assembling */
271 switch (iphc0 & LOWPAN_DISPATCH_MASK) {
272 case LOWPAN_DISPATCH_FRAG1:
273 case LOWPAN_DISPATCH_FRAGN:
275 struct lowpan_fragment *frame;
276 /* slen stores the rightmost 8 bits of the 11 bits length */
281 if (lowpan_fetch_skb_u8(skb, &slen) || /* frame length */
282 lowpan_fetch_skb_u16(skb, &tag)) /* fragment tag */
285 /* adds the 3 MSB to the 8 LSB to retrieve the 11 bits length */
286 len = ((iphc0 & 7) << 8) | slen;
288 if ((iphc0 & LOWPAN_DISPATCH_MASK) == LOWPAN_DISPATCH_FRAG1) {
289 pr_debug("%s received a FRAG1 packet (tag: %d, "
290 "size of the entire IP packet: %d)",
293 if (lowpan_fetch_skb_u8(skb, &offset))
294 goto unlock_and_drop;
295 pr_debug("%s received a FRAGN packet (tag: %d, "
296 "size of the entire IP packet: %d, "
297 "offset: %d)", __func__, tag, len, offset * 8);
301 * check if frame assembling with the same tag is
302 * already in progress
304 spin_lock_bh(&flist_lock);
306 list_for_each_entry(frame, &lowpan_fragments, list)
307 if (frame->tag == tag) {
312 /* alloc new frame structure */
314 pr_debug("%s first fragment received for tag %d, "
315 "begin packet reassembly", __func__, tag);
316 frame = lowpan_alloc_new_frame(skb, len, tag);
318 goto unlock_and_drop;
321 /* if payload fits buffer, copy it */
322 if (likely((offset * 8 + skb->len) <= frame->length))
323 skb_copy_to_linear_data_offset(frame->skb, offset * 8,
324 skb->data, skb->len);
326 goto unlock_and_drop;
328 frame->bytes_rcv += skb->len;
330 /* frame assembling complete */
331 if ((frame->bytes_rcv == frame->length) &&
332 frame->timer.expires > jiffies) {
333 /* if timer haven't expired - first of all delete it */
334 del_timer_sync(&frame->timer);
335 list_del(&frame->list);
336 spin_unlock_bh(&flist_lock);
338 pr_debug("%s successfully reassembled fragment "
339 "(tag %d)", __func__, tag);
345 if (lowpan_fetch_skb_u8(skb, &iphc0))
350 spin_unlock_bh(&flist_lock);
352 return kfree_skb(skb), 0;
358 if (lowpan_fetch_skb_u8(skb, &iphc1))
361 _saddr = &mac_cb(skb)->sa;
362 _daddr = &mac_cb(skb)->da;
364 return lowpan_process_data(skb, skb->dev, (u8 *)_saddr->hwaddr,
365 _saddr->addr_type, IEEE802154_ADDR_LEN,
366 (u8 *)_daddr->hwaddr, _daddr->addr_type,
367 IEEE802154_ADDR_LEN, iphc0, iphc1,
368 lowpan_give_skb_to_devices);
371 spin_unlock_bh(&flist_lock);
377 static int lowpan_set_address(struct net_device *dev, void *p)
379 struct sockaddr *sa = p;
381 if (netif_running(dev))
384 /* TODO: validate addr */
385 memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
391 lowpan_fragment_xmit(struct sk_buff *skb, u8 *head,
392 int mlen, int plen, int offset, int type)
394 struct sk_buff *frag;
397 hlen = (type == LOWPAN_DISPATCH_FRAG1) ?
398 LOWPAN_FRAG1_HEAD_SIZE : LOWPAN_FRAGN_HEAD_SIZE;
400 raw_dump_inline(__func__, "6lowpan fragment header", head, hlen);
402 frag = netdev_alloc_skb(skb->dev,
403 hlen + mlen + plen + IEEE802154_MFR_SIZE);
407 frag->priority = skb->priority;
409 /* copy header, MFR and payload */
411 skb_copy_to_linear_data(frag, skb_mac_header(skb), mlen);
414 skb_copy_to_linear_data_offset(frag, mlen, head, hlen);
417 skb_copy_to_linear_data_offset(frag, mlen + hlen,
418 skb_network_header(skb) + offset, plen);
420 raw_dump_table(__func__, " raw fragment dump", frag->data, frag->len);
422 return dev_queue_xmit(frag);
426 lowpan_skb_fragmentation(struct sk_buff *skb, struct net_device *dev)
428 int err, header_length, payload_length, tag, offset = 0;
431 header_length = skb->mac_len;
432 payload_length = skb->len - header_length;
433 tag = lowpan_dev_info(dev)->fragment_tag++;
435 /* first fragment header */
436 head[0] = LOWPAN_DISPATCH_FRAG1 | ((payload_length >> 8) & 0x7);
437 head[1] = payload_length & 0xff;
439 head[3] = tag & 0xff;
441 err = lowpan_fragment_xmit(skb, head, header_length, LOWPAN_FRAG_SIZE,
442 0, LOWPAN_DISPATCH_FRAG1);
445 pr_debug("%s unable to send FRAG1 packet (tag: %d)",
450 offset = LOWPAN_FRAG_SIZE;
452 /* next fragment header */
453 head[0] &= ~LOWPAN_DISPATCH_FRAG1;
454 head[0] |= LOWPAN_DISPATCH_FRAGN;
456 while (payload_length - offset > 0) {
457 int len = LOWPAN_FRAG_SIZE;
459 head[4] = offset / 8;
461 if (payload_length - offset < len)
462 len = payload_length - offset;
464 err = lowpan_fragment_xmit(skb, head, header_length,
465 len, offset, LOWPAN_DISPATCH_FRAGN);
467 pr_debug("%s unable to send a subsequent FRAGN packet "
468 "(tag: %d, offset: %d", __func__, tag, offset);
479 static netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *dev)
483 pr_debug("package xmit\n");
485 skb->dev = lowpan_dev_info(dev)->real_dev;
486 if (skb->dev == NULL) {
487 pr_debug("ERROR: no real wpan device found\n");
491 /* Send directly if less than the MTU minus the 2 checksum bytes. */
492 if (skb->len <= IEEE802154_MTU - IEEE802154_MFR_SIZE) {
493 err = dev_queue_xmit(skb);
497 pr_debug("frame is too big, fragmentation is needed\n");
498 err = lowpan_skb_fragmentation(skb, dev);
503 pr_debug("ERROR: xmit failed\n");
505 return (err < 0) ? NET_XMIT_DROP : err;
508 static struct wpan_phy *lowpan_get_phy(const struct net_device *dev)
510 struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
511 return ieee802154_mlme_ops(real_dev)->get_phy(real_dev);
514 static u16 lowpan_get_pan_id(const struct net_device *dev)
516 struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
517 return ieee802154_mlme_ops(real_dev)->get_pan_id(real_dev);
520 static u16 lowpan_get_short_addr(const struct net_device *dev)
522 struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
523 return ieee802154_mlme_ops(real_dev)->get_short_addr(real_dev);
526 static u8 lowpan_get_dsn(const struct net_device *dev)
528 struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
529 return ieee802154_mlme_ops(real_dev)->get_dsn(real_dev);
532 static struct header_ops lowpan_header_ops = {
533 .create = lowpan_header_create,
536 static const struct net_device_ops lowpan_netdev_ops = {
537 .ndo_start_xmit = lowpan_xmit,
538 .ndo_set_mac_address = lowpan_set_address,
541 static struct ieee802154_mlme_ops lowpan_mlme = {
542 .get_pan_id = lowpan_get_pan_id,
543 .get_phy = lowpan_get_phy,
544 .get_short_addr = lowpan_get_short_addr,
545 .get_dsn = lowpan_get_dsn,
548 static void lowpan_setup(struct net_device *dev)
550 dev->addr_len = IEEE802154_ADDR_LEN;
551 memset(dev->broadcast, 0xff, IEEE802154_ADDR_LEN);
552 dev->type = ARPHRD_IEEE802154;
553 /* Frame Control + Sequence Number + Address fields + Security Header */
554 dev->hard_header_len = 2 + 1 + 20 + 14;
555 dev->needed_tailroom = 2; /* FCS */
557 dev->tx_queue_len = 0;
558 dev->flags = IFF_BROADCAST | IFF_MULTICAST;
559 dev->watchdog_timeo = 0;
561 dev->netdev_ops = &lowpan_netdev_ops;
562 dev->header_ops = &lowpan_header_ops;
563 dev->ml_priv = &lowpan_mlme;
564 dev->destructor = free_netdev;
567 static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[])
569 if (tb[IFLA_ADDRESS]) {
570 if (nla_len(tb[IFLA_ADDRESS]) != IEEE802154_ADDR_LEN)
576 static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
577 struct packet_type *pt, struct net_device *orig_dev)
579 struct sk_buff *local_skb;
581 if (!netif_running(dev))
584 if (dev->type != ARPHRD_IEEE802154)
587 /* check that it's our buffer */
588 if (skb->data[0] == LOWPAN_DISPATCH_IPV6) {
589 /* Copy the packet so that the IPv6 header is
592 local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1,
593 skb_tailroom(skb), GFP_ATOMIC);
597 local_skb->protocol = htons(ETH_P_IPV6);
598 local_skb->pkt_type = PACKET_HOST;
600 /* Pull off the 1-byte of 6lowpan header. */
601 skb_pull(local_skb, 1);
603 lowpan_give_skb_to_devices(local_skb, NULL);
605 kfree_skb(local_skb);
608 switch (skb->data[0] & 0xe0) {
609 case LOWPAN_DISPATCH_IPHC: /* ipv6 datagram */
610 case LOWPAN_DISPATCH_FRAG1: /* first fragment header */
611 case LOWPAN_DISPATCH_FRAGN: /* next fragments headers */
612 local_skb = skb_clone(skb, GFP_ATOMIC);
615 process_data(local_skb);
624 return NET_RX_SUCCESS;
631 static int lowpan_newlink(struct net *src_net, struct net_device *dev,
632 struct nlattr *tb[], struct nlattr *data[])
634 struct net_device *real_dev;
635 struct lowpan_dev_record *entry;
637 pr_debug("adding new link\n");
641 /* find and hold real wpan device */
642 real_dev = dev_get_by_index(src_net, nla_get_u32(tb[IFLA_LINK]));
645 if (real_dev->type != ARPHRD_IEEE802154) {
650 lowpan_dev_info(dev)->real_dev = real_dev;
651 lowpan_dev_info(dev)->fragment_tag = 0;
652 mutex_init(&lowpan_dev_info(dev)->dev_list_mtx);
654 entry = kzalloc(sizeof(struct lowpan_dev_record), GFP_KERNEL);
657 lowpan_dev_info(dev)->real_dev = NULL;
663 /* Set the lowpan harware address to the wpan hardware address. */
664 memcpy(dev->dev_addr, real_dev->dev_addr, IEEE802154_ADDR_LEN);
666 mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
667 INIT_LIST_HEAD(&entry->list);
668 list_add_tail(&entry->list, &lowpan_devices);
669 mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
671 register_netdevice(dev);
676 static void lowpan_dellink(struct net_device *dev, struct list_head *head)
678 struct lowpan_dev_info *lowpan_dev = lowpan_dev_info(dev);
679 struct net_device *real_dev = lowpan_dev->real_dev;
680 struct lowpan_dev_record *entry, *tmp;
684 mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
685 list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) {
686 if (entry->ldev == dev) {
687 list_del(&entry->list);
691 mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
693 mutex_destroy(&lowpan_dev_info(dev)->dev_list_mtx);
695 unregister_netdevice_queue(dev, head);
700 static struct rtnl_link_ops lowpan_link_ops __read_mostly = {
702 .priv_size = sizeof(struct lowpan_dev_info),
703 .setup = lowpan_setup,
704 .newlink = lowpan_newlink,
705 .dellink = lowpan_dellink,
706 .validate = lowpan_validate,
709 static inline int __init lowpan_netlink_init(void)
711 return rtnl_link_register(&lowpan_link_ops);
714 static inline void lowpan_netlink_fini(void)
716 rtnl_link_unregister(&lowpan_link_ops);
719 static int lowpan_device_event(struct notifier_block *unused,
720 unsigned long event, void *ptr)
722 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
724 struct lowpan_dev_record *entry, *tmp;
726 if (dev->type != ARPHRD_IEEE802154)
729 if (event == NETDEV_UNREGISTER) {
730 list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) {
731 if (lowpan_dev_info(entry->ldev)->real_dev == dev)
732 lowpan_dellink(entry->ldev, &del_list);
735 unregister_netdevice_many(&del_list);
742 static struct notifier_block lowpan_dev_notifier = {
743 .notifier_call = lowpan_device_event,
746 static struct packet_type lowpan_packet_type = {
747 .type = __constant_htons(ETH_P_IEEE802154),
751 static int __init lowpan_init_module(void)
755 err = lowpan_netlink_init();
759 dev_add_pack(&lowpan_packet_type);
761 err = register_netdevice_notifier(&lowpan_dev_notifier);
763 dev_remove_pack(&lowpan_packet_type);
764 lowpan_netlink_fini();
770 static void __exit lowpan_cleanup_module(void)
772 struct lowpan_fragment *frame, *tframe;
774 lowpan_netlink_fini();
776 dev_remove_pack(&lowpan_packet_type);
778 unregister_netdevice_notifier(&lowpan_dev_notifier);
780 /* Now 6lowpan packet_type is removed, so no new fragments are
781 * expected on RX, therefore that's the time to clean incomplete
784 spin_lock_bh(&flist_lock);
785 list_for_each_entry_safe(frame, tframe, &lowpan_fragments, list) {
786 del_timer_sync(&frame->timer);
787 list_del(&frame->list);
788 dev_kfree_skb(frame->skb);
791 spin_unlock_bh(&flist_lock);
794 module_init(lowpan_init_module);
795 module_exit(lowpan_cleanup_module);
796 MODULE_LICENSE("GPL");
797 MODULE_ALIAS_RTNL_LINK("lowpan");