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WSL2-Linux-Kernel
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WSL2-Linux-Kernel/net/bluetooth/6lowpan.c

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31 KiB
C
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/*
Copyright (c) 2013-2014 Intel Corp.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License version 2 and
only 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.
*/
#include <linux/if_arp.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/module.h>
#include <linux/debugfs.h>
#include <net/ipv6.h>
#include <net/ip6_route.h>
#include <net/addrconf.h>
#include <net/af_ieee802154.h> /* to get the address type */
#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>
#include <net/bluetooth/l2cap.h>
#include <net/6lowpan.h> /* for the compression support */
#define VERSION "0.1"
static struct dentry *lowpan_psm_debugfs;
static struct dentry *lowpan_control_debugfs;
#define IFACE_NAME_TEMPLATE "bt%d"
#define EUI64_ADDR_LEN 8
struct skb_cb {
struct in6_addr addr;
struct in6_addr gw;
struct l2cap_chan *chan;
int status;
};
#define lowpan_cb(skb) ((struct skb_cb *)((skb)->cb))
/* The devices list contains those devices that we are acting
* as a proxy. The BT 6LoWPAN device is a virtual device that
* connects to the Bluetooth LE device. The real connection to
* BT device is done via l2cap layer. There exists one
* virtual device / one BT 6LoWPAN network (=hciX device).
* The list contains struct lowpan_dev elements.
*/
static LIST_HEAD(bt_6lowpan_devices);
static DEFINE_SPINLOCK(devices_lock);
/* If psm is set to 0 (default value), then 6lowpan is disabled.
* Other values are used to indicate a Protocol Service Multiplexer
* value for 6lowpan.
*/
static u16 psm_6lowpan;
/* We are listening incoming connections via this channel
*/
static struct l2cap_chan *listen_chan;
struct lowpan_peer {
struct list_head list;
struct rcu_head rcu;
struct l2cap_chan *chan;
/* peer addresses in various formats */
unsigned char eui64_addr[EUI64_ADDR_LEN];
struct in6_addr peer_addr;
};
struct lowpan_dev {
struct list_head list;
struct hci_dev *hdev;
struct net_device *netdev;
struct list_head peers;
atomic_t peer_count; /* number of items in peers list */
struct work_struct delete_netdev;
struct delayed_work notify_peers;
};
static inline struct lowpan_dev *lowpan_dev(const struct net_device *netdev)
{
return netdev_priv(netdev);
}
static inline void peer_add(struct lowpan_dev *dev, struct lowpan_peer *peer)
{
list_add_rcu(&peer->list, &dev->peers);
atomic_inc(&dev->peer_count);
}
static inline bool peer_del(struct lowpan_dev *dev, struct lowpan_peer *peer)
{
list_del_rcu(&peer->list);
kfree_rcu(peer, rcu);
module_put(THIS_MODULE);
if (atomic_dec_and_test(&dev->peer_count)) {
BT_DBG("last peer");
return true;
}
return false;
}
static inline struct lowpan_peer *peer_lookup_ba(struct lowpan_dev *dev,
bdaddr_t *ba, __u8 type)
{
struct lowpan_peer *peer;
BT_DBG("peers %d addr %pMR type %d", atomic_read(&dev->peer_count),
ba, type);
rcu_read_lock();
list_for_each_entry_rcu(peer, &dev->peers, list) {
BT_DBG("dst addr %pMR dst type %d",
&peer->chan->dst, peer->chan->dst_type);
if (bacmp(&peer->chan->dst, ba))
continue;
if (type == peer->chan->dst_type) {
rcu_read_unlock();
return peer;
}
}
rcu_read_unlock();
return NULL;
}
static inline struct lowpan_peer *__peer_lookup_chan(struct lowpan_dev *dev,
struct l2cap_chan *chan)
{
struct lowpan_peer *peer;
list_for_each_entry_rcu(peer, &dev->peers, list) {
if (peer->chan == chan)
return peer;
}
return NULL;
}
static inline struct lowpan_peer *__peer_lookup_conn(struct lowpan_dev *dev,
struct l2cap_conn *conn)
{
struct lowpan_peer *peer;
list_for_each_entry_rcu(peer, &dev->peers, list) {
if (peer->chan->conn == conn)
return peer;
}
return NULL;
}
static inline struct lowpan_peer *peer_lookup_dst(struct lowpan_dev *dev,
struct in6_addr *daddr,
struct sk_buff *skb)
{
struct lowpan_peer *peer;
struct in6_addr *nexthop;
struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
int count = atomic_read(&dev->peer_count);
BT_DBG("peers %d addr %pI6c rt %p", count, daddr, rt);
/* If we have multiple 6lowpan peers, then check where we should
* send the packet. If only one peer exists, then we can send the
* packet right away.
*/
if (count == 1) {
rcu_read_lock();
peer = list_first_or_null_rcu(&dev->peers, struct lowpan_peer,
list);
rcu_read_unlock();
return peer;
}
if (!rt) {
nexthop = &lowpan_cb(skb)->gw;
if (ipv6_addr_any(nexthop))
return NULL;
} else {
nexthop = rt6_nexthop(rt);
/* We need to remember the address because it is needed
* by bt_xmit() when sending the packet. In bt_xmit(), the
* destination routing info is not set.
*/
memcpy(&lowpan_cb(skb)->gw, nexthop, sizeof(struct in6_addr));
}
BT_DBG("gw %pI6c", nexthop);
rcu_read_lock();
list_for_each_entry_rcu(peer, &dev->peers, list) {
BT_DBG("dst addr %pMR dst type %d ip %pI6c",
&peer->chan->dst, peer->chan->dst_type,
&peer->peer_addr);
if (!ipv6_addr_cmp(&peer->peer_addr, nexthop)) {
rcu_read_unlock();
return peer;
}
}
rcu_read_unlock();
return NULL;
}
static struct lowpan_peer *lookup_peer(struct l2cap_conn *conn)
{
struct lowpan_dev *entry;
struct lowpan_peer *peer = NULL;
rcu_read_lock();
list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
peer = __peer_lookup_conn(entry, conn);
if (peer)
break;
}
rcu_read_unlock();
return peer;
}
static struct lowpan_dev *lookup_dev(struct l2cap_conn *conn)
{
struct lowpan_dev *entry;
struct lowpan_dev *dev = NULL;
rcu_read_lock();
list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
if (conn->hcon->hdev == entry->hdev) {
dev = entry;
break;
}
}
rcu_read_unlock();
return dev;
}
static int give_skb_to_upper(struct sk_buff *skb, struct net_device *dev)
{
struct sk_buff *skb_cp;
skb_cp = skb_copy(skb, GFP_ATOMIC);
if (!skb_cp)
return NET_RX_DROP;
return netif_rx(skb_cp);
}
static int iphc_decompress(struct sk_buff *skb, struct net_device *netdev,
struct l2cap_chan *chan)
{
const u8 *saddr, *daddr;
u8 iphc0, iphc1;
struct lowpan_dev *dev;
struct lowpan_peer *peer;
dev = lowpan_dev(netdev);
rcu_read_lock();
peer = __peer_lookup_chan(dev, chan);
rcu_read_unlock();
if (!peer)
return -EINVAL;
saddr = peer->eui64_addr;
daddr = dev->netdev->dev_addr;
/* at least two bytes will be used for the encoding */
if (skb->len < 2)
return -EINVAL;
if (lowpan_fetch_skb_u8(skb, &iphc0))
return -EINVAL;
if (lowpan_fetch_skb_u8(skb, &iphc1))
return -EINVAL;
return lowpan_header_decompress(skb, netdev,
saddr, IEEE802154_ADDR_LONG,
EUI64_ADDR_LEN, daddr,
IEEE802154_ADDR_LONG, EUI64_ADDR_LEN,
iphc0, iphc1);
}
static int recv_pkt(struct sk_buff *skb, struct net_device *dev,
struct l2cap_chan *chan)
{
struct sk_buff *local_skb;
int ret;
if (!netif_running(dev))
goto drop;
if (dev->type != ARPHRD_6LOWPAN)
goto drop;
skb = skb_share_check(skb, GFP_ATOMIC);
if (!skb)
goto drop;
/* check that it's our buffer */
if (skb->data[0] == LOWPAN_DISPATCH_IPV6) {
/* Copy the packet so that the IPv6 header is
* properly aligned.
*/
local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1,
skb_tailroom(skb), GFP_ATOMIC);
if (!local_skb)
goto drop;
local_skb->protocol = htons(ETH_P_IPV6);
local_skb->pkt_type = PACKET_HOST;
skb_reset_network_header(local_skb);
skb_set_transport_header(local_skb, sizeof(struct ipv6hdr));
if (give_skb_to_upper(local_skb, dev) != NET_RX_SUCCESS) {
kfree_skb(local_skb);
goto drop;
}
dev->stats.rx_bytes += skb->len;
dev->stats.rx_packets++;
consume_skb(local_skb);
consume_skb(skb);
} else {
switch (skb->data[0] & 0xe0) {
case LOWPAN_DISPATCH_IPHC: /* ipv6 datagram */
local_skb = skb_clone(skb, GFP_ATOMIC);
if (!local_skb)
goto drop;
ret = iphc_decompress(local_skb, dev, chan);
if (ret < 0) {
kfree_skb(local_skb);
goto drop;
}
local_skb->protocol = htons(ETH_P_IPV6);
local_skb->pkt_type = PACKET_HOST;
local_skb->dev = dev;
if (give_skb_to_upper(local_skb, dev)
!= NET_RX_SUCCESS) {
kfree_skb(local_skb);
goto drop;
}
dev->stats.rx_bytes += skb->len;
dev->stats.rx_packets++;
consume_skb(local_skb);
consume_skb(skb);
break;
default:
break;
}
}
return NET_RX_SUCCESS;
drop:
dev->stats.rx_dropped++;
return NET_RX_DROP;
}
/* Packet from BT LE device */
static int chan_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
{
struct lowpan_dev *dev;
struct lowpan_peer *peer;
int err;
peer = lookup_peer(chan->conn);
if (!peer)
return -ENOENT;
dev = lookup_dev(chan->conn);
if (!dev || !dev->netdev)
return -ENOENT;
err = recv_pkt(skb, dev->netdev, chan);
if (err) {
BT_DBG("recv pkt %d", err);
err = -EAGAIN;
}
return err;
}
static u8 get_addr_type_from_eui64(u8 byte)
{
/* Is universal(0) or local(1) bit */
return ((byte & 0x02) ? BDADDR_LE_RANDOM : BDADDR_LE_PUBLIC);
}
static void copy_to_bdaddr(struct in6_addr *ip6_daddr, bdaddr_t *addr)
{
u8 *eui64 = ip6_daddr->s6_addr + 8;
addr->b[0] = eui64[7];
addr->b[1] = eui64[6];
addr->b[2] = eui64[5];
addr->b[3] = eui64[2];
addr->b[4] = eui64[1];
addr->b[5] = eui64[0];
}
static void convert_dest_bdaddr(struct in6_addr *ip6_daddr,
bdaddr_t *addr, u8 *addr_type)
{
copy_to_bdaddr(ip6_daddr, addr);
/* We need to toggle the U/L bit that we got from IPv6 address
* so that we get the proper address and type of the BD address.
*/
addr->b[5] ^= 0x02;
*addr_type = get_addr_type_from_eui64(addr->b[5]);
}
static int setup_header(struct sk_buff *skb, struct net_device *netdev,
bdaddr_t *peer_addr, u8 *peer_addr_type)
{
struct in6_addr ipv6_daddr;
struct lowpan_dev *dev;
struct lowpan_peer *peer;
bdaddr_t addr, *any = BDADDR_ANY;
u8 *daddr = any->b;
int err, status = 0;
dev = lowpan_dev(netdev);
memcpy(&ipv6_daddr, &lowpan_cb(skb)->addr, sizeof(ipv6_daddr));
if (ipv6_addr_is_multicast(&ipv6_daddr)) {
lowpan_cb(skb)->chan = NULL;
} else {
u8 addr_type;
/* Get destination BT device from skb.
* If there is no such peer then discard the packet.
*/
convert_dest_bdaddr(&ipv6_daddr, &addr, &addr_type);
BT_DBG("dest addr %pMR type %d IP %pI6c", &addr,
addr_type, &ipv6_daddr);
peer = peer_lookup_ba(dev, &addr, addr_type);
if (!peer) {
/* The packet might be sent to 6lowpan interface
* because of routing (either via default route
* or user set route) so get peer according to
* the destination address.
*/
peer = peer_lookup_dst(dev, &ipv6_daddr, skb);
if (!peer) {
BT_DBG("no such peer %pMR found", &addr);
return -ENOENT;
}
}
daddr = peer->eui64_addr;
*peer_addr = addr;
*peer_addr_type = addr_type;
lowpan_cb(skb)->chan = peer->chan;
status = 1;
}
lowpan_header_compress(skb, netdev, ETH_P_IPV6, daddr,
dev->netdev->dev_addr, skb->len);
err = dev_hard_header(skb, netdev, ETH_P_IPV6, NULL, NULL, 0);
if (err < 0)
return err;
return status;
}
static int header_create(struct sk_buff *skb, struct net_device *netdev,
unsigned short type, const void *_daddr,
const void *_saddr, unsigned int len)
{
struct ipv6hdr *hdr;
if (type != ETH_P_IPV6)
return -EINVAL;
hdr = ipv6_hdr(skb);
memcpy(&lowpan_cb(skb)->addr, &hdr->daddr, sizeof(struct in6_addr));
return 0;
}
/* Packet to BT LE device */
static int send_pkt(struct l2cap_chan *chan, struct sk_buff *skb,
struct net_device *netdev)
{
struct msghdr msg;
struct kvec iv;
int err;
/* Remember the skb so that we can send EAGAIN to the caller if
* we run out of credits.
*/
chan->data = skb;
iv.iov_base = skb->data;
iv.iov_len = skb->len;
memset(&msg, 0, sizeof(msg));
iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, &iv, 1, skb->len);
err = l2cap_chan_send(chan, &msg, skb->len);
if (err > 0) {
netdev->stats.tx_bytes += err;
netdev->stats.tx_packets++;
return 0;
}
if (!err)
err = lowpan_cb(skb)->status;
if (err < 0) {
if (err == -EAGAIN)
netdev->stats.tx_dropped++;
else
netdev->stats.tx_errors++;
}
return err;
}
static int send_mcast_pkt(struct sk_buff *skb, struct net_device *netdev)
{
struct sk_buff *local_skb;
struct lowpan_dev *entry;
int err = 0;
rcu_read_lock();
list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
struct lowpan_peer *pentry;
struct lowpan_dev *dev;
if (entry->netdev != netdev)
continue;
dev = lowpan_dev(entry->netdev);
list_for_each_entry_rcu(pentry, &dev->peers, list) {
int ret;
local_skb = skb_clone(skb, GFP_ATOMIC);
BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
netdev->name,
&pentry->chan->dst, pentry->chan->dst_type,
&pentry->peer_addr, pentry->chan);
ret = send_pkt(pentry->chan, local_skb, netdev);
if (ret < 0)
err = ret;
kfree_skb(local_skb);
}
}
rcu_read_unlock();
return err;
}
static netdev_tx_t bt_xmit(struct sk_buff *skb, struct net_device *netdev)
{
int err = 0;
bdaddr_t addr;
u8 addr_type;
/* We must take a copy of the skb before we modify/replace the ipv6
* header as the header could be used elsewhere
*/
skb = skb_unshare(skb, GFP_ATOMIC);
if (!skb)
return NET_XMIT_DROP;
/* Return values from setup_header()
* <0 - error, packet is dropped
* 0 - this is a multicast packet
* 1 - this is unicast packet
*/
err = setup_header(skb, netdev, &addr, &addr_type);
if (err < 0) {
kfree_skb(skb);
return NET_XMIT_DROP;
}
if (err) {
if (lowpan_cb(skb)->chan) {
BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
netdev->name, &addr, addr_type,
&lowpan_cb(skb)->addr, lowpan_cb(skb)->chan);
err = send_pkt(lowpan_cb(skb)->chan, skb, netdev);
} else {
err = -ENOENT;
}
} else {
/* We need to send the packet to every device behind this
* interface.
*/
err = send_mcast_pkt(skb, netdev);
}
dev_kfree_skb(skb);
if (err)
BT_DBG("ERROR: xmit failed (%d)", err);
return err < 0 ? NET_XMIT_DROP : err;
}
static struct lock_class_key bt_tx_busylock;
static struct lock_class_key bt_netdev_xmit_lock_key;
static void bt_set_lockdep_class_one(struct net_device *dev,
struct netdev_queue *txq,
void *_unused)
{
lockdep_set_class(&txq->_xmit_lock, &bt_netdev_xmit_lock_key);
}
static int bt_dev_init(struct net_device *dev)
{
netdev_for_each_tx_queue(dev, bt_set_lockdep_class_one, NULL);
dev->qdisc_tx_busylock = &bt_tx_busylock;
return 0;
}
static const struct net_device_ops netdev_ops = {
.ndo_init = bt_dev_init,
.ndo_start_xmit = bt_xmit,
};
static struct header_ops header_ops = {
.create = header_create,
};
static void netdev_setup(struct net_device *dev)
{
dev->addr_len = EUI64_ADDR_LEN;
dev->type = ARPHRD_6LOWPAN;
dev->hard_header_len = 0;
dev->needed_tailroom = 0;
dev->mtu = IPV6_MIN_MTU;
dev->tx_queue_len = 0;
dev->flags = IFF_RUNNING | IFF_POINTOPOINT |
IFF_MULTICAST;
dev->watchdog_timeo = 0;
dev->netdev_ops = &netdev_ops;
dev->header_ops = &header_ops;
dev->destructor = free_netdev;
}
static struct device_type bt_type = {
.name = "bluetooth",
};
static void set_addr(u8 *eui, u8 *addr, u8 addr_type)
{
/* addr is the BT address in little-endian format */
eui[0] = addr[5];
eui[1] = addr[4];
eui[2] = addr[3];
eui[3] = 0xFF;
eui[4] = 0xFE;
eui[5] = addr[2];
eui[6] = addr[1];
eui[7] = addr[0];
/* Universal/local bit set, BT 6lowpan draft ch. 3.2.1 */
if (addr_type == BDADDR_LE_PUBLIC)
eui[0] &= ~0x02;
else
eui[0] |= 0x02;
BT_DBG("type %d addr %*phC", addr_type, 8, eui);
}
static void set_dev_addr(struct net_device *netdev, bdaddr_t *addr,
u8 addr_type)
{
netdev->addr_assign_type = NET_ADDR_PERM;
set_addr(netdev->dev_addr, addr->b, addr_type);
}
static void ifup(struct net_device *netdev)
{
int err;
rtnl_lock();
err = dev_open(netdev);
if (err < 0)
BT_INFO("iface %s cannot be opened (%d)", netdev->name, err);
rtnl_unlock();
}
static void ifdown(struct net_device *netdev)
{
int err;
rtnl_lock();
err = dev_close(netdev);
if (err < 0)
BT_INFO("iface %s cannot be closed (%d)", netdev->name, err);
rtnl_unlock();
}
static void do_notify_peers(struct work_struct *work)
{
struct lowpan_dev *dev = container_of(work, struct lowpan_dev,
notify_peers.work);
netdev_notify_peers(dev->netdev); /* send neighbour adv at startup */
}
static bool is_bt_6lowpan(struct hci_conn *hcon)
{
if (hcon->type != LE_LINK)
return false;
if (!psm_6lowpan)
return false;
return true;
}
static struct l2cap_chan *chan_create(void)
{
struct l2cap_chan *chan;
chan = l2cap_chan_create();
if (!chan)
return NULL;
l2cap_chan_set_defaults(chan);
chan->chan_type = L2CAP_CHAN_CONN_ORIENTED;
chan->mode = L2CAP_MODE_LE_FLOWCTL;
chan->omtu = 65535;
chan->imtu = chan->omtu;
return chan;
}
static struct l2cap_chan *chan_open(struct l2cap_chan *pchan)
{
struct l2cap_chan *chan;
chan = chan_create();
if (!chan)
return NULL;
chan->remote_mps = chan->omtu;
chan->mps = chan->omtu;
chan->state = BT_CONNECTED;
return chan;
}
static void set_ip_addr_bits(u8 addr_type, u8 *addr)
{
if (addr_type == BDADDR_LE_PUBLIC)
*addr |= 0x02;
else
*addr &= ~0x02;
}
static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan,
struct lowpan_dev *dev)
{
struct lowpan_peer *peer;
peer = kzalloc(sizeof(*peer), GFP_ATOMIC);
if (!peer)
return NULL;
peer->chan = chan;
memset(&peer->peer_addr, 0, sizeof(struct in6_addr));
/* RFC 2464 ch. 5 */
peer->peer_addr.s6_addr[0] = 0xFE;
peer->peer_addr.s6_addr[1] = 0x80;
set_addr((u8 *)&peer->peer_addr.s6_addr + 8, chan->dst.b,
chan->dst_type);
memcpy(&peer->eui64_addr, (u8 *)&peer->peer_addr.s6_addr + 8,
EUI64_ADDR_LEN);
/* IPv6 address needs to have the U/L bit set properly so toggle
* it back here.
*/
set_ip_addr_bits(chan->dst_type, (u8 *)&peer->peer_addr.s6_addr + 8);
spin_lock(&devices_lock);
INIT_LIST_HEAD(&peer->list);
peer_add(dev, peer);
spin_unlock(&devices_lock);
/* Notifying peers about us needs to be done without locks held */
INIT_DELAYED_WORK(&dev->notify_peers, do_notify_peers);
schedule_delayed_work(&dev->notify_peers, msecs_to_jiffies(100));
return peer->chan;
}
static int setup_netdev(struct l2cap_chan *chan, struct lowpan_dev **dev)
{
struct net_device *netdev;
int err = 0;
netdev = alloc_netdev(sizeof(struct lowpan_dev), IFACE_NAME_TEMPLATE,
NET_NAME_UNKNOWN, netdev_setup);
if (!netdev)
return -ENOMEM;
set_dev_addr(netdev, &chan->src, chan->src_type);
netdev->netdev_ops = &netdev_ops;
SET_NETDEV_DEV(netdev, &chan->conn->hcon->dev);
SET_NETDEV_DEVTYPE(netdev, &bt_type);
err = register_netdev(netdev);
if (err < 0) {
BT_INFO("register_netdev failed %d", err);
free_netdev(netdev);
goto out;
}
BT_DBG("ifindex %d peer bdaddr %pMR type %d my addr %pMR type %d",
netdev->ifindex, &chan->dst, chan->dst_type,
&chan->src, chan->src_type);
set_bit(__LINK_STATE_PRESENT, &netdev->state);
*dev = netdev_priv(netdev);
(*dev)->netdev = netdev;
(*dev)->hdev = chan->conn->hcon->hdev;
INIT_LIST_HEAD(&(*dev)->peers);
spin_lock(&devices_lock);
INIT_LIST_HEAD(&(*dev)->list);
list_add_rcu(&(*dev)->list, &bt_6lowpan_devices);
spin_unlock(&devices_lock);
return 0;
out:
return err;
}
static inline void chan_ready_cb(struct l2cap_chan *chan)
{
struct lowpan_dev *dev;
dev = lookup_dev(chan->conn);
BT_DBG("chan %p conn %p dev %p", chan, chan->conn, dev);
if (!dev) {
if (setup_netdev(chan, &dev) < 0) {
l2cap_chan_del(chan, -ENOENT);
return;
}
}
if (!try_module_get(THIS_MODULE))
return;
add_peer_chan(chan, dev);
ifup(dev->netdev);
}
static inline struct l2cap_chan *chan_new_conn_cb(struct l2cap_chan *pchan)
{
struct l2cap_chan *chan;
chan = chan_open(pchan);
chan->ops = pchan->ops;
BT_DBG("chan %p pchan %p", chan, pchan);
return chan;
}
static void delete_netdev(struct work_struct *work)
{
struct lowpan_dev *entry = container_of(work, struct lowpan_dev,
delete_netdev);
unregister_netdev(entry->netdev);
/* The entry pointer is deleted in device_event() */
}
static void chan_close_cb(struct l2cap_chan *chan)
{
struct lowpan_dev *entry;
struct lowpan_dev *dev = NULL;
struct lowpan_peer *peer;
int err = -ENOENT;
bool last = false, removed = true;
BT_DBG("chan %p conn %p", chan, chan->conn);
if (chan->conn && chan->conn->hcon) {
if (!is_bt_6lowpan(chan->conn->hcon))
return;
/* If conn is set, then the netdev is also there and we should
* not remove it.
*/
removed = false;
}
spin_lock(&devices_lock);
list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
dev = lowpan_dev(entry->netdev);
peer = __peer_lookup_chan(dev, chan);
if (peer) {
last = peer_del(dev, peer);
err = 0;
BT_DBG("dev %p removing %speer %p", dev,
last ? "last " : "1 ", peer);
BT_DBG("chan %p orig refcnt %d", chan,
atomic_read(&chan->kref.refcount));
l2cap_chan_put(chan);
break;
}
}
if (!err && last && dev && !atomic_read(&dev->peer_count)) {
spin_unlock(&devices_lock);
cancel_delayed_work_sync(&dev->notify_peers);
ifdown(dev->netdev);
if (!removed) {
INIT_WORK(&entry->delete_netdev, delete_netdev);
schedule_work(&entry->delete_netdev);
}
} else {
spin_unlock(&devices_lock);
}
return;
}
static void chan_state_change_cb(struct l2cap_chan *chan, int state, int err)
{
BT_DBG("chan %p conn %p state %s err %d", chan, chan->conn,
state_to_string(state), err);
}
static struct sk_buff *chan_alloc_skb_cb(struct l2cap_chan *chan,
unsigned long hdr_len,
unsigned long len, int nb)
{
/* Note that we must allocate using GFP_ATOMIC here as
* this function is called originally from netdev hard xmit
* function in atomic context.
*/
return bt_skb_alloc(hdr_len + len, GFP_ATOMIC);
}
static void chan_suspend_cb(struct l2cap_chan *chan)
{
struct sk_buff *skb = chan->data;
BT_DBG("chan %p conn %p skb %p", chan, chan->conn, skb);
if (!skb)
return;
lowpan_cb(skb)->status = -EAGAIN;
}
static void chan_resume_cb(struct l2cap_chan *chan)
{
struct sk_buff *skb = chan->data;
BT_DBG("chan %p conn %p skb %p", chan, chan->conn, skb);
if (!skb)
return;
lowpan_cb(skb)->status = 0;
}
static long chan_get_sndtimeo_cb(struct l2cap_chan *chan)
{
return L2CAP_CONN_TIMEOUT;
}
static const struct l2cap_ops bt_6lowpan_chan_ops = {
.name = "L2CAP 6LoWPAN channel",
.new_connection = chan_new_conn_cb,
.recv = chan_recv_cb,
.close = chan_close_cb,
.state_change = chan_state_change_cb,
.ready = chan_ready_cb,
.resume = chan_resume_cb,
.suspend = chan_suspend_cb,
.get_sndtimeo = chan_get_sndtimeo_cb,
.alloc_skb = chan_alloc_skb_cb,
.teardown = l2cap_chan_no_teardown,
.defer = l2cap_chan_no_defer,
.set_shutdown = l2cap_chan_no_set_shutdown,
};
static inline __u8 bdaddr_type(__u8 type)
{
if (type == ADDR_LE_DEV_PUBLIC)
return BDADDR_LE_PUBLIC;
else
return BDADDR_LE_RANDOM;
}
static struct l2cap_chan *chan_get(void)
{
struct l2cap_chan *pchan;
pchan = chan_create();
if (!pchan)
return NULL;
pchan->ops = &bt_6lowpan_chan_ops;
return pchan;
}
static int bt_6lowpan_connect(bdaddr_t *addr, u8 dst_type)
{
struct l2cap_chan *pchan;
int err;
pchan = chan_get();
if (!pchan)
return -EINVAL;
err = l2cap_chan_connect(pchan, cpu_to_le16(psm_6lowpan), 0,
addr, dst_type);
BT_DBG("chan %p err %d", pchan, err);
if (err < 0)
l2cap_chan_put(pchan);
return err;
}
static int bt_6lowpan_disconnect(struct l2cap_conn *conn, u8 dst_type)
{
struct lowpan_peer *peer;
BT_DBG("conn %p dst type %d", conn, dst_type);
peer = lookup_peer(conn);
if (!peer)
return -ENOENT;
BT_DBG("peer %p chan %p", peer, peer->chan);
l2cap_chan_close(peer->chan, ENOENT);
return 0;
}
static struct l2cap_chan *bt_6lowpan_listen(void)
{
bdaddr_t *addr = BDADDR_ANY;
struct l2cap_chan *pchan;
int err;
if (psm_6lowpan == 0)
return NULL;
pchan = chan_get();
if (!pchan)
return NULL;
pchan->state = BT_LISTEN;
pchan->src_type = BDADDR_LE_PUBLIC;
atomic_set(&pchan->nesting, L2CAP_NESTING_PARENT);
BT_DBG("psm 0x%04x chan %p src type %d", psm_6lowpan, pchan,
pchan->src_type);
err = l2cap_add_psm(pchan, addr, cpu_to_le16(psm_6lowpan));
if (err) {
l2cap_chan_put(pchan);
BT_ERR("psm cannot be added err %d", err);
return NULL;
}
return pchan;
}
static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type,
struct l2cap_conn **conn)
{
struct hci_conn *hcon;
struct hci_dev *hdev;
bdaddr_t *src = BDADDR_ANY;
int n;
n = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu",
&addr->b[5], &addr->b[4], &addr->b[3],
&addr->b[2], &addr->b[1], &addr->b[0],
addr_type);
if (n < 7)
return -EINVAL;
hdev = hci_get_route(addr, src);
if (!hdev)
return -ENOENT;
hci_dev_lock(hdev);
hcon = hci_conn_hash_lookup_ba(hdev, LE_LINK, addr);
hci_dev_unlock(hdev);
if (!hcon)
return -ENOENT;
*conn = (struct l2cap_conn *)hcon->l2cap_data;
BT_DBG("conn %p dst %pMR type %d", *conn, &hcon->dst, hcon->dst_type);
return 0;
}
static void disconnect_all_peers(void)
{
struct lowpan_dev *entry;
struct lowpan_peer *peer, *tmp_peer, *new_peer;
struct list_head peers;
INIT_LIST_HEAD(&peers);
/* We make a separate list of peers as the close_cb() will
* modify the device peers list so it is better not to mess
* with the same list at the same time.
*/
rcu_read_lock();
list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
list_for_each_entry_rcu(peer, &entry->peers, list) {
new_peer = kmalloc(sizeof(*new_peer), GFP_ATOMIC);
if (!new_peer)
break;
new_peer->chan = peer->chan;
INIT_LIST_HEAD(&new_peer->list);
list_add(&new_peer->list, &peers);
}
}
rcu_read_unlock();
spin_lock(&devices_lock);
list_for_each_entry_safe(peer, tmp_peer, &peers, list) {
l2cap_chan_close(peer->chan, ENOENT);
list_del_rcu(&peer->list);
kfree_rcu(peer, rcu);
module_put(THIS_MODULE);
}
spin_unlock(&devices_lock);
}
struct set_psm {
struct work_struct work;
u16 psm;
};
static void do_psm_set(struct work_struct *work)
{
struct set_psm *set_psm = container_of(work, struct set_psm, work);
if (set_psm->psm == 0 || psm_6lowpan != set_psm->psm)
/* Disconnect existing connections if 6lowpan is
* disabled (psm = 0), or if psm changes.
*/
disconnect_all_peers();
psm_6lowpan = set_psm->psm;
if (listen_chan) {
l2cap_chan_close(listen_chan, 0);
l2cap_chan_put(listen_chan);
}
listen_chan = bt_6lowpan_listen();
kfree(set_psm);
}
static int lowpan_psm_set(void *data, u64 val)
{
struct set_psm *set_psm;
set_psm = kzalloc(sizeof(*set_psm), GFP_KERNEL);
if (!set_psm)
return -ENOMEM;
set_psm->psm = val;
INIT_WORK(&set_psm->work, do_psm_set);
schedule_work(&set_psm->work);
return 0;
}
static int lowpan_psm_get(void *data, u64 *val)
{
*val = psm_6lowpan;
return 0;
}
DEFINE_SIMPLE_ATTRIBUTE(lowpan_psm_fops, lowpan_psm_get,
lowpan_psm_set, "%llu\n");
static ssize_t lowpan_control_write(struct file *fp,
const char __user *user_buffer,
size_t count,
loff_t *position)
{
char buf[32];
size_t buf_size = min(count, sizeof(buf) - 1);
int ret;
bdaddr_t addr;
u8 addr_type;
struct l2cap_conn *conn = NULL;
if (copy_from_user(buf, user_buffer, buf_size))
return -EFAULT;
buf[buf_size] = '\0';
if (memcmp(buf, "connect ", 8) == 0) {
ret = get_l2cap_conn(&buf[8], &addr, &addr_type, &conn);
if (ret == -EINVAL)
return ret;
if (listen_chan) {
l2cap_chan_close(listen_chan, 0);
l2cap_chan_put(listen_chan);
listen_chan = NULL;
}
if (conn) {
struct lowpan_peer *peer;
if (!is_bt_6lowpan(conn->hcon))
return -EINVAL;
peer = lookup_peer(conn);
if (peer) {
BT_DBG("6LoWPAN connection already exists");
return -EALREADY;
}
BT_DBG("conn %p dst %pMR type %d user %d", conn,
&conn->hcon->dst, conn->hcon->dst_type,
addr_type);
}
ret = bt_6lowpan_connect(&addr, addr_type);
if (ret < 0)
return ret;
return count;
}
if (memcmp(buf, "disconnect ", 11) == 0) {
ret = get_l2cap_conn(&buf[11], &addr, &addr_type, &conn);
if (ret < 0)
return ret;
ret = bt_6lowpan_disconnect(conn, addr_type);
if (ret < 0)
return ret;
return count;
}
return count;
}
static int lowpan_control_show(struct seq_file *f, void *ptr)
{
struct lowpan_dev *entry;
struct lowpan_peer *peer;
spin_lock(&devices_lock);
list_for_each_entry(entry, &bt_6lowpan_devices, list) {
list_for_each_entry(peer, &entry->peers, list)
seq_printf(f, "%pMR (type %u)\n",
&peer->chan->dst, peer->chan->dst_type);
}
spin_unlock(&devices_lock);
return 0;
}
static int lowpan_control_open(struct inode *inode, struct file *file)
{
return single_open(file, lowpan_control_show, inode->i_private);
}
static const struct file_operations lowpan_control_fops = {
.open = lowpan_control_open,
.read = seq_read,
.write = lowpan_control_write,
.llseek = seq_lseek,
.release = single_release,
};
static void disconnect_devices(void)
{
struct lowpan_dev *entry, *tmp, *new_dev;
struct list_head devices;
INIT_LIST_HEAD(&devices);
/* We make a separate list of devices because the unregister_netdev()
* will call device_event() which will also want to modify the same
* devices list.
*/
rcu_read_lock();
list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
new_dev = kmalloc(sizeof(*new_dev), GFP_ATOMIC);
if (!new_dev)
break;
new_dev->netdev = entry->netdev;
INIT_LIST_HEAD(&new_dev->list);
list_add_rcu(&new_dev->list, &devices);
}
rcu_read_unlock();
list_for_each_entry_safe(entry, tmp, &devices, list) {
ifdown(entry->netdev);
BT_DBG("Unregistering netdev %s %p",
entry->netdev->name, entry->netdev);
unregister_netdev(entry->netdev);
kfree(entry);
}
}
static int device_event(struct notifier_block *unused,
unsigned long event, void *ptr)
{
struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
struct lowpan_dev *entry;
if (netdev->type != ARPHRD_6LOWPAN)
return NOTIFY_DONE;
switch (event) {
case NETDEV_UNREGISTER:
spin_lock(&devices_lock);
list_for_each_entry(entry, &bt_6lowpan_devices, list) {
if (entry->netdev == netdev) {
BT_DBG("Unregistered netdev %s %p",
netdev->name, netdev);
list_del(&entry->list);
kfree(entry);
break;
}
}
spin_unlock(&devices_lock);
break;
}
return NOTIFY_DONE;
}
static struct notifier_block bt_6lowpan_dev_notifier = {
.notifier_call = device_event,
};
static int __init bt_6lowpan_init(void)
{
lowpan_psm_debugfs = debugfs_create_file("6lowpan_psm", 0644,
bt_debugfs, NULL,
&lowpan_psm_fops);
lowpan_control_debugfs = debugfs_create_file("6lowpan_control", 0644,
bt_debugfs, NULL,
&lowpan_control_fops);
return register_netdevice_notifier(&bt_6lowpan_dev_notifier);
}
static void __exit bt_6lowpan_exit(void)
{
debugfs_remove(lowpan_psm_debugfs);
debugfs_remove(lowpan_control_debugfs);
if (listen_chan) {
l2cap_chan_close(listen_chan, 0);
l2cap_chan_put(listen_chan);
}
disconnect_devices();
unregister_netdevice_notifier(&bt_6lowpan_dev_notifier);
}
module_init(bt_6lowpan_init);
module_exit(bt_6lowpan_exit);
MODULE_AUTHOR("Jukka Rissanen <jukka.rissanen@linux.intel.com>");
MODULE_DESCRIPTION("Bluetooth 6LoWPAN");
MODULE_VERSION(VERSION);
MODULE_LICENSE("GPL");
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