/* Copyright 2011, Siemens AG
* written by Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
*/
/* Based on patches from Jon Smirl <jonsmirl@gmail.com>
* Copyright (c) 2011 Jon Smirl <jonsmirl@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
/* Jon's code is based on 6lowpan implementation for Contiki which is:
* Copyright (c) 2008, Swedish Institute of Computer Science.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <linux/bitops.h>
#include <linux/if_arp.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/netdevice.h>
#include <net/af_ieee802154.h>
#include <net/ieee802154.h>
#include <net/ieee802154_netdev.h>
#include <net/6lowpan.h>
#include <net/ipv6.h>
#include "reassembly.h"
static LIST_HEAD(lowpan_devices);
/* private device info */
struct lowpan_dev_info {
struct net_device *real_dev; /* real WPAN device ptr */
struct mutex dev_list_mtx; /* mutex for list ops */
__be16 fragment_tag;
};
struct lowpan_dev_record {
struct net_device *ldev;
struct list_head list;
};
static inline struct
lowpan_dev_info *lowpan_dev_info(const struct net_device *dev)
{
return netdev_priv(dev);
}
static inline void lowpan_address_flip(u8 *src, u8 *dest)
{
int i;
for (i = 0; i < IEEE802154_ADDR_LEN; i++)
(dest)[IEEE802154_ADDR_LEN - i - 1] = (src)[i];
}
static int lowpan_header_create(struct sk_buff *skb,
struct net_device *dev,
unsigned short type, const void *_daddr,
const void *_saddr, unsigned int len)
{
const u8 *saddr = _saddr;
const u8 *daddr = _daddr;
struct ieee802154_addr sa, da;
struct ieee802154_mac_cb *cb = mac_cb_init(skb);
/* TODO:
* if this package isn't ipv6 one, where should it be routed?
*/
if (type != ETH_P_IPV6)
return 0;
if (!saddr)
saddr = dev->dev_addr;
raw_dump_inline(__func__, "saddr", (unsigned char *)saddr, 8);
raw_dump_inline(__func__, "daddr", (unsigned char *)daddr, 8);
lowpan_header_compress(skb, dev, type, daddr, saddr, len);
/* NOTE1: I'm still unsure about the fact that compression and WPAN
* header are created here and not later in the xmit. So wait for
* an opinion of net maintainers.
*/
/* NOTE2: to be absolutely correct, we must derive PANid information
* from MAC subif of the 'dev' and 'real_dev' network devices, but
* this isn't implemented in mainline yet, so currently we assign 0xff
*/
cb->type = IEEE802154_FC_TYPE_DATA;
/* prepare wpan address data */
sa.mode = IEEE802154_ADDR_LONG;
sa.pan_id = ieee802154_mlme_ops(dev)->get_pan_id(dev);
sa.extended_addr = ieee802154_devaddr_from_raw(saddr);
/* intra-PAN communications */
da.pan_id = sa.pan_id;
/* if the destination address is the broadcast address, use the
* corresponding short address
*/
if (lowpan_is_addr_broadcast(daddr)) {
da.mode = IEEE802154_ADDR_SHORT;
da.short_addr = cpu_to_le16(IEEE802154_ADDR_BROADCAST);
} else {
da.mode = IEEE802154_ADDR_LONG;
da.extended_addr = ieee802154_devaddr_from_raw(daddr);
}
cb->ackreq = !lowpan_is_addr_broadcast(daddr);
return dev_hard_header(skb, lowpan_dev_info(dev)->real_dev,
type, (void *)&da, (void *)&sa, 0);
}
static int lowpan_give_skb_to_devices(struct sk_buff *skb,
struct net_device *dev)
{
struct lowpan_dev_record *entry;
struct sk_buff *skb_cp;
int stat = NET_RX_SUCCESS;
rcu_read_lock();
list_for_each_entry_rcu(entry, &lowpan_devices, list)
if (lowpan_dev_info(entry->ldev)->real_dev == skb->dev) {
skb_cp = skb_copy(skb, GFP_ATOMIC);
if (!skb_cp) {
stat = -ENOMEM;
break;
}
skb_cp->dev = entry->ldev;
stat = netif_rx(skb_cp);
}
rcu_read_unlock();
return stat;
}
static int process_data(struct sk_buff *skb, const struct ieee802154_hdr *hdr)
{
u8 iphc0, iphc1;
struct ieee802154_addr_sa sa, da;
void *sap, *dap;
raw_dump_table(__func__, "raw skb data dump", skb->data, skb->len);
/* at least two bytes will be used for the encoding */
if (skb->len < 2)
goto drop;
if (lowpan_fetch_skb_u8(skb, &iphc0))
goto drop;
if (lowpan_fetch_skb_u8(skb, &iphc1))
goto drop;
ieee802154_addr_to_sa(&sa, &hdr->source);
ieee802154_addr_to_sa(&da, &hdr->dest);
if (sa.addr_type == IEEE802154_ADDR_SHORT)
sap = &sa.short_addr;
else
sap = &sa.hwaddr;
if (da.addr_type == IEEE802154_ADDR_SHORT)
dap = &da.short_addr;
else
dap = &da.hwaddr;
return lowpan_process_data(skb, skb->dev, sap, sa.addr_type,
IEEE802154_ADDR_LEN, dap, da.addr_type,
IEEE802154_ADDR_LEN, iphc0, iphc1,
lowpan_give_skb_to_devices);
drop:
kfree_skb(skb);
return -EINVAL;
}
static int lowpan_set_address(struct net_device *dev, void *p)
{
struct sockaddr *sa = p;
if (netif_running(dev))
return -EBUSY;
/* TODO: validate addr */
memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
return 0;
}
static int
lowpan_fragment_xmit(struct sk_buff *skb, u8 *head,
int mlen, int plen, int offset, int type)
{
struct sk_buff *frag;
int hlen;
hlen = (type == LOWPAN_DISPATCH_FRAG1) ?
LOWPAN_FRAG1_HEAD_SIZE : LOWPAN_FRAGN_HEAD_SIZE;
raw_dump_inline(__func__, "6lowpan fragment header", head, hlen);
frag = netdev_alloc_skb(skb->dev,
hlen + mlen + plen + IEEE802154_MFR_SIZE);
if (!frag)
return -ENOMEM;
frag->priority = skb->priority;
/* copy header, MFR and payload */
skb_put(frag, mlen);
skb_copy_to_linear_data(frag, skb_mac_header(skb), mlen);
skb_put(frag, hlen);
skb_copy_to_linear_data_offset(frag, mlen, head, hlen);
skb_put(frag, plen);
skb_copy_to_linear_data_offset(frag, mlen + hlen,
skb_network_header(skb) + offset, plen);
raw_dump_table(__func__, " raw fragment dump", frag->data, frag->len);
return dev_queue_xmit(frag);
}
static int
lowpan_skb_fragmentation(struct sk_buff *skb, struct net_device *dev)
{
int err;
u16 dgram_offset, dgram_size, payload_length, header_length,
lowpan_size, frag_plen, offset;
__be16 tag;
u8 head[5];
header_length = skb->mac_len;
payload_length = skb->len - header_length;
tag = lowpan_dev_info(dev)->fragment_tag++;
lowpan_size = skb_network_header_len(skb);
dgram_size = lowpan_uncompress_size(skb, &dgram_offset) -
header_length;
/* first fragment header */
head[0] = LOWPAN_DISPATCH_FRAG1 | ((dgram_size >> 8) & 0x7);
head[1] = dgram_size & 0xff;
memcpy(head + 2, &tag, sizeof(tag));
/* calc the nearest payload length(divided to 8) for first fragment
* which fits into a IEEE802154_MTU
*/
frag_plen = round_down(IEEE802154_MTU - header_length -
LOWPAN_FRAG1_HEAD_SIZE - lowpan_size -
IEEE802154_MFR_SIZE, 8);
err = lowpan_fragment_xmit(skb, head, header_length,
frag_plen + lowpan_size, 0,
LOWPAN_DISPATCH_FRAG1);
if (err) {
pr_debug("%s unable to send FRAG1 packet (tag: %d)",
__func__, tag);
goto exit;
}
offset = lowpan_size + frag_plen;
dgram_offset += frag_plen;
/* next fragment header */
head[0] &= ~LOWPAN_DISPATCH_FRAG1;
head[0] |= LOWPAN_DISPATCH_FRAGN;
frag_plen = round_down(IEEE802154_MTU - header_length -
LOWPAN_FRAGN_HEAD_SIZE - IEEE802154_MFR_SIZE, 8);
while (payload_length - offset > 0) {
int len = frag_plen;
head[4] = dgram_offset >> 3;
if (payload_length - offset < len)
len = payload_length - offset;
err = lowpan_fragment_xmit(skb, head, header_length, len,
offset, LOWPAN_DISPATCH_FRAGN);
if (err) {
pr_debug("%s unable to send a FRAGN packet. (tag: %d, offset: %d)\n",
__func__, tag, offset);
goto exit;
}
offset += len;
dgram_offset += len;
}
exit:
return err;
}
static netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *dev)
{
int err = -1;
pr_debug("package xmit\n");
skb->dev = lowpan_dev_info(dev)->real_dev;
if (skb->dev == NULL) {
pr_debug("ERROR: no real wpan device found\n");
goto error;
}
/* Send directly if less than the MTU minus the 2 checksum bytes. */
if (skb->len <= IEEE802154_MTU - IEEE802154_MFR_SIZE) {
err = dev_queue_xmit(skb);
goto out;
}
pr_debug("frame is too big, fragmentation is needed\n");
err = lowpan_skb_fragmentation(skb, dev);
error:
dev_kfree_skb(skb);
out:
if (err)
pr_debug("ERROR: xmit failed\n");
return (err < 0) ? NET_XMIT_DROP : err;
}
static struct wpan_phy *lowpan_get_phy(const struct net_device *dev)
{
struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
return ieee802154_mlme_ops(real_dev)->get_phy(real_dev);
}
static __le16 lowpan_get_pan_id(const struct net_device *dev)
{
struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
return ieee802154_mlme_ops(real_dev)->get_pan_id(real_dev);
}
static __le16 lowpan_get_short_addr(const struct net_device *dev)
{
struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
return ieee802154_mlme_ops(real_dev)->get_short_addr(real_dev);
}
static u8 lowpan_get_dsn(const struct net_device *dev)
{
struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
return ieee802154_mlme_ops(real_dev)->get_dsn(real_dev);
}
static struct header_ops lowpan_header_ops = {
.create = lowpan_header_create,
};
static struct lock_class_key lowpan_tx_busylock;
static struct lock_class_key lowpan_netdev_xmit_lock_key;
static void lowpan_set_lockdep_class_one(struct net_device *dev,
struct netdev_queue *txq,
void *_unused)
{
lockdep_set_class(&txq->_xmit_lock,
&lowpan_netdev_xmit_lock_key);
}
static int lowpan_dev_init(struct net_device *dev)
{
netdev_for_each_tx_queue(dev, lowpan_set_lockdep_class_one, NULL);
dev->qdisc_tx_busylock = &lowpan_tx_busylock;
return 0;
}
static const struct net_device_ops lowpan_netdev_ops = {
.ndo_init = lowpan_dev_init,
.ndo_start_xmit = lowpan_xmit,
.ndo_set_mac_address = lowpan_set_address,
};
static struct ieee802154_mlme_ops lowpan_mlme = {
.get_pan_id = lowpan_get_pan_id,
.get_phy = lowpan_get_phy,
.get_short_addr = lowpan_get_short_addr,
.get_dsn = lowpan_get_dsn,
};
static void lowpan_setup(struct net_device *dev)
{
dev->addr_len = IEEE802154_ADDR_LEN;
memset(dev->broadcast, 0xff, IEEE802154_ADDR_LEN);
dev->type = ARPHRD_IEEE802154;
/* Frame Control + Sequence Number + Address fields + Security Header */
dev->hard_header_len = 2 + 1 + 20 + 14;
dev->needed_tailroom = 2; /* FCS */
dev->mtu = 1281;
dev->tx_queue_len = 0;
dev->flags = IFF_BROADCAST | IFF_MULTICAST;
dev->watchdog_timeo = 0;
dev->netdev_ops = &lowpan_netdev_ops;
dev->header_ops = &lowpan_header_ops;
dev->ml_priv = &lowpan_mlme;
dev->destructor = free_netdev;
}
static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[])
{
if (tb[IFLA_ADDRESS]) {
if (nla_len(tb[IFLA_ADDRESS]) != IEEE802154_ADDR_LEN)
return -EINVAL;
}
return 0;
}
static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pt, struct net_device *orig_dev)
{
struct ieee802154_hdr hdr;
int ret;
skb = skb_share_check(skb, GFP_ATOMIC);
if (!skb)
goto drop;
if (!netif_running(dev))
goto drop_skb;
if (dev->type != ARPHRD_IEEE802154)
goto drop_skb;
if (ieee802154_hdr_peek_addrs(skb, &hdr) < 0)
goto drop_skb;
/* check that it's our buffer */
if (skb->data[0] == LOWPAN_DISPATCH_IPV6) {
skb->protocol = htons(ETH_P_IPV6);
skb->pkt_type = PACKET_HOST;
/* Pull off the 1-byte of 6lowpan header. */
skb_pull(skb, 1);
ret = lowpan_give_skb_to_devices(skb, NULL);
if (ret == NET_RX_DROP)
goto drop;
} else {
switch (skb->data[0] & 0xe0) {
case LOWPAN_DISPATCH_IPHC: /* ipv6 datagram */
ret = process_data(skb, &hdr);
if (ret == NET_RX_DROP)
goto drop;
break;
case LOWPAN_DISPATCH_FRAG1: /* first fragment header */
ret = lowpan_frag_rcv(skb, LOWPAN_DISPATCH_FRAG1);
if (ret == 1) {
ret = process_data(skb, &hdr);
if (ret == NET_RX_DROP)
goto drop;
}
break;
case LOWPAN_DISPATCH_FRAGN: /* next fragments headers */
ret = lowpan_frag_rcv(skb, LOWPAN_DISPATCH_FRAGN);
if (ret == 1) {
ret = process_data(skb, &hdr);
if (ret == NET_RX_DROP)
goto drop;
}
break;
default:
break;
}
}
return NET_RX_SUCCESS;
drop_skb:
kfree_skb(skb);
drop:
return NET_RX_DROP;
}
static int lowpan_newlink(struct net *src_net, struct net_device *dev,
struct nlattr *tb[], struct nlattr *data[])
{
struct net_device *real_dev;
struct lowpan_dev_record *entry;
pr_debug("adding new link\n");
if (!tb[IFLA_LINK])
return -EINVAL;
/* find and hold real wpan device */
real_dev = dev_get_by_index(src_net, nla_get_u32(tb[IFLA_LINK]));
if (!real_dev)
return -ENODEV;
if (real_dev->type != ARPHRD_IEEE802154) {
dev_put(real_dev);
return -EINVAL;
}
lowpan_dev_info(dev)->real_dev = real_dev;
mutex_init(&lowpan_dev_info(dev)->dev_list_mtx);
entry = kzalloc(sizeof(*entry), GFP_KERNEL);
if (!entry) {
dev_put(real_dev);
lowpan_dev_info(dev)->real_dev = NULL;
return -ENOMEM;
}
entry->ldev = dev;
/* Set the lowpan harware address to the wpan hardware address. */
memcpy(dev->dev_addr, real_dev->dev_addr, IEEE802154_ADDR_LEN);
mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
INIT_LIST_HEAD(&entry->list);
list_add_tail(&entry->list, &lowpan_devices);
mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
register_netdevice(dev);
return 0;
}
static void lowpan_dellink(struct net_device *dev, struct list_head *head)
{
struct lowpan_dev_info *lowpan_dev = lowpan_dev_info(dev);
struct net_device *real_dev = lowpan_dev->real_dev;
struct lowpan_dev_record *entry, *tmp;
ASSERT_RTNL();
mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) {
if (entry->ldev == dev) {
list_del(&entry->list);
kfree(entry);
}
}
mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
mutex_destroy(&lowpan_dev_info(dev)->dev_list_mtx);
unregister_netdevice_queue(dev, head);
dev_put(real_dev);
}
static struct rtnl_link_ops lowpan_link_ops __read_mostly = {
.kind = "lowpan",
.priv_size = sizeof(struct lowpan_dev_info),
.setup = lowpan_setup,
.newlink = lowpan_newlink,
.dellink = lowpan_dellink,
.validate = lowpan_validate,
};
static inline int __init lowpan_netlink_init(void)
{
return rtnl_link_register(&lowpan_link_ops);
}
static inline void lowpan_netlink_fini(void)
{
rtnl_link_unregister(&lowpan_link_ops);
}
static int lowpan_device_event(struct notifier_block *unused,
unsigned long event, void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
LIST_HEAD(del_list);
struct lowpan_dev_record *entry, *tmp;
if (dev->type != ARPHRD_IEEE802154)
goto out;
if (event == NETDEV_UNREGISTER) {
list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) {
if (lowpan_dev_info(entry->ldev)->real_dev == dev)
lowpan_dellink(entry->ldev, &del_list);
}
unregister_netdevice_many(&del_list);
}
out:
return NOTIFY_DONE;
}
static struct notifier_block lowpan_dev_notifier = {
.notifier_call = lowpan_device_event,
};
static struct packet_type lowpan_packet_type = {
.type = htons(ETH_P_IEEE802154),
.func = lowpan_rcv,
};
static int __init lowpan_init_module(void)
{
int err = 0;
err = lowpan_net_frag_init();
if (err < 0)
goto out;
err = lowpan_netlink_init();
if (err < 0)
goto out_frag;
dev_add_pack(&lowpan_packet_type);
err = register_netdevice_notifier(&lowpan_dev_notifier);
if (err < 0)
goto out_pack;
return 0;
out_pack:
dev_remove_pack(&lowpan_packet_type);
lowpan_netlink_fini();
out_frag:
lowpan_net_frag_exit();
out:
return err;
}
static void __exit lowpan_cleanup_module(void)
{
lowpan_netlink_fini();
dev_remove_pack(&lowpan_packet_type);
lowpan_net_frag_exit();
unregister_netdevice_notifier(&lowpan_dev_notifier);
}
module_init(lowpan_init_module);
module_exit(lowpan_cleanup_module);
MODULE_LICENSE("GPL");
MODULE_ALIAS_RTNL_LINK("lowpan");
