diff options
author | Jukka Rissanen <jukka.rissanen@linux.intel.com> | 2013-12-11 17:05:37 +0200 |
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committer | Marcel Holtmann <marcel@holtmann.org> | 2013-12-11 12:57:55 -0800 |
commit | 18722c247023035b9e2e2a08a887adec2a9a6e49 (patch) | |
tree | ea345642b91699e7ea6994533c79aa24aafe20c8 /net/bluetooth/6lowpan.c | |
parent | e74bccb8a598c37840b547a7d606bd8c959cc2e4 (diff) | |
download | op-kernel-dev-18722c247023035b9e2e2a08a887adec2a9a6e49.zip op-kernel-dev-18722c247023035b9e2e2a08a887adec2a9a6e49.tar.gz |
Bluetooth: Enable 6LoWPAN support for BT LE devices
This is initial version of
http://tools.ietf.org/html/draft-ietf-6lo-btle-00
By default the 6LoWPAN support is not activated and user
needs to tweak /sys/kernel/debug/bluetooth/hci0/6lowpan
file.
The kernel needs IPv6 support before 6LoWPAN is usable.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Diffstat (limited to 'net/bluetooth/6lowpan.c')
-rw-r--r-- | net/bluetooth/6lowpan.c | 886 |
1 files changed, 886 insertions, 0 deletions
diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c new file mode 100644 index 0000000..ba840fe --- /dev/null +++ b/net/bluetooth/6lowpan.c @@ -0,0 +1,886 @@ +/* + Copyright (c) 2013 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/version.h> +#include <linux/if_arp.h> +#include <linux/netdevice.h> +#include <linux/etherdevice.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 "../ieee802154/6lowpan.h" /* for the compression support */ + +#define IFACE_NAME_TEMPLATE "bt%d" +#define EUI64_ADDR_LEN 8 + +struct skb_cb { + struct in6_addr addr; + struct l2cap_conn *conn; +}; +#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_RWLOCK(devices_lock); + +struct lowpan_peer { + struct list_head list; + struct l2cap_conn *conn; + + /* 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(&peer->list, &dev->peers); + atomic_inc(&dev->peer_count); +} + +static inline bool peer_del(struct lowpan_dev *dev, struct lowpan_peer *peer) +{ + list_del(&peer->list); + + 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, *tmp; + + BT_DBG("peers %d addr %pMR type %d", atomic_read(&dev->peer_count), + ba, type); + + list_for_each_entry_safe(peer, tmp, &dev->peers, list) { + BT_DBG("addr %pMR type %d", + &peer->conn->hcon->dst, peer->conn->hcon->dst_type); + + if (bacmp(&peer->conn->hcon->dst, ba)) + continue; + + if (type == peer->conn->hcon->dst_type) + return peer; + } + + return NULL; +} + +static inline struct lowpan_peer *peer_lookup_conn(struct lowpan_dev *dev, + struct l2cap_conn *conn) +{ + struct lowpan_peer *peer, *tmp; + + list_for_each_entry_safe(peer, tmp, &dev->peers, list) { + if (peer->conn == conn) + return peer; + } + + return NULL; +} + +static struct lowpan_peer *lookup_peer(struct l2cap_conn *conn) +{ + struct lowpan_dev *entry, *tmp; + struct lowpan_peer *peer = NULL; + unsigned long flags; + + read_lock_irqsave(&devices_lock, flags); + + list_for_each_entry_safe(entry, tmp, &bt_6lowpan_devices, list) { + peer = peer_lookup_conn(entry, conn); + if (peer) + break; + } + + read_unlock_irqrestore(&devices_lock, flags); + + return peer; +} + +static struct lowpan_dev *lookup_dev(struct l2cap_conn *conn) +{ + struct lowpan_dev *entry, *tmp; + struct lowpan_dev *dev = NULL; + unsigned long flags; + + read_lock_irqsave(&devices_lock, flags); + + list_for_each_entry_safe(entry, tmp, &bt_6lowpan_devices, list) { + if (conn->hcon->hdev == entry->hdev) { + dev = entry; + break; + } + } + + read_unlock_irqrestore(&devices_lock, flags); + + return dev; +} + +/* print data in line */ +static inline void raw_dump_inline(const char *caller, char *msg, + unsigned char *buf, int len) +{ + if (msg) + pr_debug("%s():%s: ", caller, msg); + + print_hex_dump_debug("", DUMP_PREFIX_NONE, + 16, 1, buf, len, false); +} + +/* print data in a table format: + * + * addr: xx xx xx xx xx xx + * addr: xx xx xx xx xx xx + * ... + */ +static inline void raw_dump_table(const char *caller, char *msg, + unsigned char *buf, int len) +{ + if (msg) + pr_debug("%s():%s:\n", caller, msg); + + print_hex_dump_debug("\t", DUMP_PREFIX_OFFSET, + 16, 1, buf, len, false); +} + +static int give_skb_to_upper(struct sk_buff *skb, struct net_device *dev) +{ + struct sk_buff *skb_cp; + int ret; + + skb_cp = skb_copy(skb, GFP_ATOMIC); + if (!skb_cp) + return -ENOMEM; + + ret = netif_rx(skb_cp); + + BT_DBG("receive skb %d", ret); + if (ret < 0) + return NET_RX_DROP; + + return ret; +} + +static int process_data(struct sk_buff *skb, struct net_device *netdev, + struct l2cap_conn *conn) +{ + const u8 *saddr, *daddr; + u8 iphc0, iphc1; + struct lowpan_dev *dev; + struct lowpan_peer *peer; + unsigned long flags; + + dev = lowpan_dev(netdev); + + read_lock_irqsave(&devices_lock, flags); + peer = peer_lookup_conn(dev, conn); + read_unlock_irqrestore(&devices_lock, flags); + if (!peer) + goto drop; + + saddr = peer->eui64_addr; + daddr = dev->netdev->dev_addr; + + /* 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; + + return lowpan_process_data(skb, netdev, + saddr, IEEE802154_ADDR_LONG, EUI64_ADDR_LEN, + daddr, IEEE802154_ADDR_LONG, EUI64_ADDR_LEN, + iphc0, iphc1, give_skb_to_upper); + +drop: + kfree_skb(skb); + return -EINVAL; +} + +static int recv_pkt(struct sk_buff *skb, struct net_device *dev, + struct l2cap_conn *conn) +{ + struct sk_buff *local_skb; + int ret; + + if (!netif_running(dev)) + goto drop; + + if (dev->type != ARPHRD_6LOWPAN) + 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++; + + kfree_skb(local_skb); + kfree_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 = process_data(local_skb, dev, conn); + if (ret != NET_RX_SUCCESS) + goto drop; + + dev->stats.rx_bytes += skb->len; + dev->stats.rx_packets++; + + kfree_skb(skb); + break; + default: + break; + } + } + + return NET_RX_SUCCESS; + +drop: + kfree_skb(skb); + return NET_RX_DROP; +} + +/* Packet from BT LE device */ +int bt_6lowpan_recv(struct l2cap_conn *conn, struct sk_buff *skb) +{ + struct lowpan_dev *dev; + struct lowpan_peer *peer; + int err; + + peer = lookup_peer(conn); + if (!peer) + return -ENOENT; + + dev = lookup_dev(conn); + if (dev && !dev->netdev) + return -ENOENT; + + err = recv_pkt(skb, dev->netdev, conn); + BT_DBG("recv pkt %d", err); + + return err; +} + +static inline int skbuff_copy(void *msg, int len, int count, int mtu, + struct sk_buff *skb, struct net_device *dev) +{ + struct sk_buff **frag; + int sent = 0; + + memcpy(skb_put(skb, count), msg, count); + + sent += count; + msg += count; + len -= count; + + dev->stats.tx_bytes += count; + dev->stats.tx_packets++; + + raw_dump_table(__func__, "Sending", skb->data, skb->len); + + /* Continuation fragments (no L2CAP header) */ + frag = &skb_shinfo(skb)->frag_list; + while (len > 0) { + struct sk_buff *tmp; + + count = min_t(unsigned int, mtu, len); + + tmp = bt_skb_alloc(count, GFP_ATOMIC); + if (IS_ERR(tmp)) + return PTR_ERR(tmp); + + *frag = tmp; + + memcpy(skb_put(*frag, count), msg, count); + + raw_dump_table(__func__, "Sending fragment", + (*frag)->data, count); + + (*frag)->priority = skb->priority; + + sent += count; + msg += count; + len -= count; + + skb->len += (*frag)->len; + skb->data_len += (*frag)->len; + + frag = &(*frag)->next; + + dev->stats.tx_bytes += count; + dev->stats.tx_packets++; + } + + return sent; +} + +static struct sk_buff *create_pdu(struct l2cap_conn *conn, void *msg, + size_t len, u32 priority, + struct net_device *dev) +{ + struct sk_buff *skb; + int err, count; + struct l2cap_hdr *lh; + + /* FIXME: This mtu check should be not needed and atm is only used for + * testing purposes + */ + if (conn->mtu > (L2CAP_LE_MIN_MTU + L2CAP_HDR_SIZE)) + conn->mtu = L2CAP_LE_MIN_MTU + L2CAP_HDR_SIZE; + + count = min_t(unsigned int, (conn->mtu - L2CAP_HDR_SIZE), len); + + BT_DBG("conn %p len %zu mtu %d count %d", conn, len, conn->mtu, count); + + skb = bt_skb_alloc(count + L2CAP_HDR_SIZE, GFP_ATOMIC); + if (IS_ERR(skb)) + return skb; + + skb->priority = priority; + + lh = (struct l2cap_hdr *)skb_put(skb, L2CAP_HDR_SIZE); + lh->cid = cpu_to_le16(L2CAP_FC_6LOWPAN); + lh->len = cpu_to_le16(len); + + err = skbuff_copy(msg, len, count, conn->mtu, skb, dev); + if (unlikely(err < 0)) { + kfree_skb(skb); + BT_DBG("skbuff copy %d failed", err); + return ERR_PTR(err); + } + + return skb; +} + +static int conn_send(struct l2cap_conn *conn, + void *msg, size_t len, u32 priority, + struct net_device *dev) +{ + struct sk_buff *skb; + + skb = create_pdu(conn, msg, len, priority, dev); + if (IS_ERR(skb)) + return -EINVAL; + + BT_DBG("conn %p skb %p len %d priority %u", conn, skb, skb->len, + skb->priority); + + hci_send_acl(conn->hchan, skb, ACL_START); + + return 0; +} + +static void get_dest_bdaddr(struct in6_addr *ip6_daddr, + bdaddr_t *addr, u8 *addr_type) +{ + u8 *eui64; + + 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]; + + addr->b[5] ^= 2; + + /* Set universal/local bit to 0 */ + if (addr->b[5] & 1) { + addr->b[5] &= ~1; + *addr_type = BDADDR_LE_PUBLIC; + } else { + *addr_type = BDADDR_LE_RANDOM; + } +} + +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; + struct lowpan_dev *dev; + struct lowpan_peer *peer; + bdaddr_t addr, *any = BDADDR_ANY; + u8 *saddr, *daddr = any->b; + u8 addr_type; + + if (type != ETH_P_IPV6) + return -EINVAL; + + hdr = ipv6_hdr(skb); + + dev = lowpan_dev(netdev); + + if (ipv6_addr_is_multicast(&hdr->daddr)) { + memcpy(&lowpan_cb(skb)->addr, &hdr->daddr, + sizeof(struct in6_addr)); + lowpan_cb(skb)->conn = NULL; + } else { + unsigned long flags; + + /* Get destination BT device from skb. + * If there is no such peer then discard the packet. + */ + get_dest_bdaddr(&hdr->daddr, &addr, &addr_type); + + BT_DBG("dest addr %pMR type %d", &addr, addr_type); + + read_lock_irqsave(&devices_lock, flags); + peer = peer_lookup_ba(dev, &addr, addr_type); + read_unlock_irqrestore(&devices_lock, flags); + + if (!peer) { + BT_DBG("no such peer %pMR found", &addr); + return -ENOENT; + } + + daddr = peer->eui64_addr; + + memcpy(&lowpan_cb(skb)->addr, &hdr->daddr, + sizeof(struct in6_addr)); + lowpan_cb(skb)->conn = peer->conn; + } + + saddr = dev->netdev->dev_addr; + + return lowpan_header_compress(skb, netdev, type, daddr, saddr, len); +} + +/* Packet to BT LE device */ +static int send_pkt(struct l2cap_conn *conn, const void *saddr, + const void *daddr, struct sk_buff *skb, + struct net_device *netdev) +{ + raw_dump_table(__func__, "raw skb data dump before fragmentation", + skb->data, skb->len); + + return conn_send(conn, skb->data, skb->len, 0, netdev); +} + +static void send_mcast_pkt(struct sk_buff *skb, struct net_device *netdev) +{ + struct sk_buff *local_skb; + struct lowpan_dev *entry, *tmp; + unsigned long flags; + + read_lock_irqsave(&devices_lock, flags); + + list_for_each_entry_safe(entry, tmp, &bt_6lowpan_devices, list) { + struct lowpan_peer *pentry, *ptmp; + struct lowpan_dev *dev; + + if (entry->netdev != netdev) + continue; + + dev = lowpan_dev(entry->netdev); + + list_for_each_entry_safe(pentry, ptmp, &dev->peers, list) { + local_skb = skb_clone(skb, GFP_ATOMIC); + + send_pkt(pentry->conn, netdev->dev_addr, + pentry->eui64_addr, local_skb, netdev); + + kfree_skb(local_skb); + } + } + + read_unlock_irqrestore(&devices_lock, flags); +} + +static netdev_tx_t bt_xmit(struct sk_buff *skb, struct net_device *netdev) +{ + int err = 0; + unsigned char *eui64_addr; + struct lowpan_dev *dev; + struct lowpan_peer *peer; + bdaddr_t addr; + u8 addr_type; + + if (ipv6_addr_is_multicast(&lowpan_cb(skb)->addr)) { + /* We need to send the packet to every device + * behind this interface. + */ + send_mcast_pkt(skb, netdev); + } else { + unsigned long flags; + + get_dest_bdaddr(&lowpan_cb(skb)->addr, &addr, &addr_type); + eui64_addr = lowpan_cb(skb)->addr.s6_addr + 8; + dev = lowpan_dev(netdev); + + read_lock_irqsave(&devices_lock, flags); + peer = peer_lookup_ba(dev, &addr, addr_type); + read_unlock_irqrestore(&devices_lock, flags); + + BT_DBG("xmit from %s to %pMR (%pI6c) peer %p", netdev->name, + &addr, &lowpan_cb(skb)->addr, peer); + + if (peer && peer->conn) + err = send_pkt(peer->conn, netdev->dev_addr, + eui64_addr, skb, netdev); + } + dev_kfree_skb(skb); + + if (err) + BT_DBG("ERROR: xmit failed (%d)", err); + + return (err < 0) ? NET_XMIT_DROP : err; +} + +static const struct net_device_ops netdev_ops = { + .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; + 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]; + + eui[0] ^= 2; + + /* Universal/local bit set, RFC 4291 */ + if (addr_type == BDADDR_LE_PUBLIC) + eui[0] |= 1; + else + eui[0] &= ~1; +} + +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); + netdev->dev_addr[0] ^= 2; +} + +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 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; + + return test_bit(HCI_CONN_6LOWPAN, &hcon->flags); +} + +static int add_peer_conn(struct l2cap_conn *conn, struct lowpan_dev *dev) +{ + struct lowpan_peer *peer; + unsigned long flags; + + peer = kzalloc(sizeof(*peer), GFP_ATOMIC); + if (!peer) + return -ENOMEM; + + peer->conn = conn; + 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, conn->hcon->dst.b, + conn->hcon->dst_type); + + memcpy(&peer->eui64_addr, (u8 *)&peer->peer_addr.s6_addr + 8, + EUI64_ADDR_LEN); + peer->eui64_addr[0] ^= 2; /* second bit-flip (Universe/Local) + * is done according RFC2464 + */ + + raw_dump_inline(__func__, "peer IPv6 address", + (unsigned char *)&peer->peer_addr, 16); + raw_dump_inline(__func__, "peer EUI64 address", peer->eui64_addr, 8); + + write_lock_irqsave(&devices_lock, flags); + INIT_LIST_HEAD(&peer->list); + peer_add(dev, peer); + write_unlock_irqrestore(&devices_lock, flags); + + /* 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 0; +} + +/* This gets called when BT LE 6LoWPAN device is connected. We then + * create network device that acts as a proxy between BT LE device + * and kernel network stack. + */ +int bt_6lowpan_add_conn(struct l2cap_conn *conn) +{ + struct lowpan_peer *peer = NULL; + struct lowpan_dev *dev; + struct net_device *netdev; + int err = 0; + unsigned long flags; + + if (!is_bt_6lowpan(conn->hcon)) + return 0; + + peer = lookup_peer(conn); + if (peer) + return -EEXIST; + + dev = lookup_dev(conn); + if (dev) + return add_peer_conn(conn, dev); + + netdev = alloc_netdev(sizeof(*dev), IFACE_NAME_TEMPLATE, netdev_setup); + if (!netdev) + return -ENOMEM; + + set_dev_addr(netdev, &conn->hcon->src, conn->hcon->src_type); + + netdev->netdev_ops = &netdev_ops; + SET_NETDEV_DEV(netdev, &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 my addr %pMR", + netdev->ifindex, &conn->hcon->dst, &conn->hcon->src); + set_bit(__LINK_STATE_PRESENT, &netdev->state); + + dev = netdev_priv(netdev); + dev->netdev = netdev; + dev->hdev = conn->hcon->hdev; + INIT_LIST_HEAD(&dev->peers); + + write_lock_irqsave(&devices_lock, flags); + INIT_LIST_HEAD(&dev->list); + list_add(&dev->list, &bt_6lowpan_devices); + write_unlock_irqrestore(&devices_lock, flags); + + ifup(netdev); + + return add_peer_conn(conn, dev); + +out: + return err; +} + +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() */ +} + +int bt_6lowpan_del_conn(struct l2cap_conn *conn) +{ + struct lowpan_dev *entry, *tmp; + struct lowpan_dev *dev = NULL; + struct lowpan_peer *peer; + int err = -ENOENT; + unsigned long flags; + bool last = false; + + if (!is_bt_6lowpan(conn->hcon)) + return 0; + + write_lock_irqsave(&devices_lock, flags); + + list_for_each_entry_safe(entry, tmp, &bt_6lowpan_devices, list) { + dev = lowpan_dev(entry->netdev); + peer = peer_lookup_conn(dev, conn); + if (peer) { + last = peer_del(dev, peer); + err = 0; + break; + } + } + + if (!err && last && dev && !atomic_read(&dev->peer_count)) { + write_unlock_irqrestore(&devices_lock, flags); + + cancel_delayed_work_sync(&dev->notify_peers); + + /* bt_6lowpan_del_conn() is called with hci dev lock held which + * means that we must delete the netdevice in worker thread. + */ + INIT_WORK(&entry->delete_netdev, delete_netdev); + schedule_work(&entry->delete_netdev); + } else { + write_unlock_irqrestore(&devices_lock, flags); + } + + return err; +} + +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, *tmp; + unsigned long flags; + + if (netdev->type != ARPHRD_6LOWPAN) + return NOTIFY_DONE; + + switch (event) { + case NETDEV_UNREGISTER: + write_lock_irqsave(&devices_lock, flags); + list_for_each_entry_safe(entry, tmp, &bt_6lowpan_devices, + list) { + if (entry->netdev == netdev) { + list_del(&entry->list); + kfree(entry); + break; + } + } + write_unlock_irqrestore(&devices_lock, flags); + break; + } + + return NOTIFY_DONE; +} + +static struct notifier_block bt_6lowpan_dev_notifier = { + .notifier_call = device_event, +}; + +int bt_6lowpan_init(void) +{ + return register_netdevice_notifier(&bt_6lowpan_dev_notifier); +} + +void bt_6lowpan_cleanup(void) +{ + unregister_netdevice_notifier(&bt_6lowpan_dev_notifier); +} |