/* 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/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_enable_debugfs; static struct dentry *lowpan_control_debugfs; #define IFACE_NAME_TEMPLATE "bt%d" 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); static bool enable_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_btle_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_btle_dev * lowpan_btle_dev(const struct net_device *netdev) { return (struct lowpan_btle_dev *)lowpan_dev(netdev)->priv; } static inline void peer_add(struct lowpan_btle_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_btle_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_btle_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_btle_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_btle_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_btle_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, daddr); /* 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_btle_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_btle_dev *lookup_dev(struct l2cap_conn *conn) { struct lowpan_btle_dev *entry; struct lowpan_btle_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_ni(skb_cp); } static int iphc_decompress(struct sk_buff *skb, struct net_device *netdev, struct l2cap_chan *chan) { const u8 *saddr, *daddr; struct lowpan_btle_dev *dev; struct lowpan_peer *peer; dev = lowpan_btle_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; return lowpan_header_decompress(skb, netdev, daddr, saddr); } 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 || !skb->len) goto drop; skb_reset_network_header(skb); skb = skb_share_check(skb, GFP_ATOMIC); if (!skb) goto drop; /* check that it's our buffer */ if (lowpan_is_ipv6(*skb_network_header(skb))) { /* Pull off the 1-byte of 6lowpan header. */ skb_pull(skb, 1); /* 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; local_skb->dev = dev; 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 if (lowpan_is_iphc(*skb_network_header(skb))) { local_skb = skb_clone(skb, GFP_ATOMIC); if (!local_skb) goto drop; local_skb->dev = dev; 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; 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 { goto drop; } 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_btle_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 ipv6hdr *hdr; struct lowpan_btle_dev *dev; struct lowpan_peer *peer; bdaddr_t addr, *any = BDADDR_ANY; u8 *daddr = any->b; int err, status = 0; hdr = ipv6_hdr(skb); dev = lowpan_btle_dev(netdev); memcpy(&ipv6_daddr, &hdr->daddr, 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, daddr, dev->netdev->dev_addr); 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) { if (type != ETH_P_IPV6) return -EINVAL; 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_btle_dev *entry; int err = 0; rcu_read_lock(); list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { struct lowpan_peer *pentry; struct lowpan_btle_dev *dev; if (entry->netdev != netdev) continue; dev = lowpan_btle_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 int bt_dev_init(struct net_device *dev) { netdev_lockdep_set_classes(dev); 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->hard_header_len = 0; dev->needed_tailroom = 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_btle_dev *dev = container_of(work, struct lowpan_btle_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 (!enable_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->imtu = 1280; 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_btle_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_btle_dev **dev) { struct net_device *netdev; int err = 0; netdev = alloc_netdev(LOWPAN_PRIV_SIZE(sizeof(struct lowpan_btle_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->hdev->dev); SET_NETDEV_DEVTYPE(netdev, &bt_type); *dev = lowpan_btle_dev(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); err = lowpan_register_netdev(netdev, LOWPAN_LLTYPE_BTLE); if (err < 0) { BT_INFO("register_netdev failed %d", err); spin_lock(&devices_lock); list_del_rcu(&(*dev)->list); spin_unlock(&devices_lock); 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); return 0; out: return err; } static inline void chan_ready_cb(struct l2cap_chan *chan) { struct lowpan_btle_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_create(); if (!chan) return NULL; chan->ops = pchan->ops; BT_DBG("chan %p pchan %p", chan, pchan); return chan; } static void delete_netdev(struct work_struct *work) { struct lowpan_btle_dev *entry = container_of(work, struct lowpan_btle_dev, delete_netdev); lowpan_unregister_netdev(entry->netdev); /* The entry pointer is deleted by the netdev destructor. */ } static void chan_close_cb(struct l2cap_chan *chan) { struct lowpan_btle_dev *entry; struct lowpan_btle_dev *dev = NULL; struct lowpan_peer *peer; int err = -ENOENT; bool last = false, remove = 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. */ remove = false; } spin_lock(&devices_lock); list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { dev = lowpan_btle_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 (remove) { 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 int bt_6lowpan_connect(bdaddr_t *addr, u8 dst_type) { struct l2cap_chan *chan; int err; chan = chan_create(); if (!chan) return -EINVAL; chan->ops = &bt_6lowpan_chan_ops; err = l2cap_chan_connect(chan, cpu_to_le16(L2CAP_PSM_IPSP), 0, addr, dst_type); BT_DBG("chan %p err %d", chan, err); if (err < 0) l2cap_chan_put(chan); 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 *chan; int err; if (!enable_6lowpan) return NULL; chan = chan_create(); if (!chan) return NULL; chan->ops = &bt_6lowpan_chan_ops; chan->state = BT_LISTEN; chan->src_type = BDADDR_LE_PUBLIC; atomic_set(&chan->nesting, L2CAP_NESTING_PARENT); BT_DBG("chan %p src type %d", chan, chan->src_type); err = l2cap_add_psm(chan, addr, cpu_to_le16(L2CAP_PSM_IPSP)); if (err) { l2cap_chan_put(chan); BT_ERR("psm cannot be added err %d", err); return NULL; } return chan; } 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; 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; /* The LE_PUBLIC address type is ignored because of BDADDR_ANY */ hdev = hci_get_route(addr, BDADDR_ANY, BDADDR_LE_PUBLIC); if (!hdev) return -ENOENT; hci_dev_lock(hdev); hcon = hci_conn_hash_lookup_le(hdev, addr, *addr_type); 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_btle_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); } spin_unlock(&devices_lock); } struct set_enable { struct work_struct work; bool flag; }; static void do_enable_set(struct work_struct *work) { struct set_enable *set_enable = container_of(work, struct set_enable, work); if (!set_enable->flag || enable_6lowpan != set_enable->flag) /* Disconnect existing connections if 6lowpan is * disabled */ disconnect_all_peers(); enable_6lowpan = set_enable->flag; if (listen_chan) { l2cap_chan_close(listen_chan, 0); l2cap_chan_put(listen_chan); } listen_chan = bt_6lowpan_listen(); kfree(set_enable); } static int lowpan_enable_set(void *data, u64 val) { struct set_enable *set_enable; set_enable = kzalloc(sizeof(*set_enable), GFP_KERNEL); if (!set_enable) return -ENOMEM; set_enable->flag = !!val; INIT_WORK(&set_enable->work, do_enable_set); schedule_work(&set_enable->work); return 0; } static int lowpan_enable_get(void *data, u64 *val) { *val = enable_6lowpan; return 0; } DEFINE_SIMPLE_ATTRIBUTE(lowpan_enable_fops, lowpan_enable_get, lowpan_enable_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_btle_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_btle_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); lowpan_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_btle_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); 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_enable_debugfs = debugfs_create_file("6lowpan_enable", 0644, bt_debugfs, NULL, &lowpan_enable_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_enable_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");