net: add IEEE 802.15.4 socket family implementation

Add support for communication over IEEE 802.15.4 networks. This implementation
is neither certified nor complete, but aims to that goal. This commit contains
only the socket interface for communication over IEEE 802.15.4 networks.
One can either send RAW datagrams or use SOCK_DGRAM to encapsulate data
inside normal IEEE 802.15.4 packets.

Configuration interface, drivers and software MAC 802.15.4 implementation will
follow.

Initial implementation was done by Maxim Gorbachyov, Maxim Osipov and Pavel
Smolensky as a research project at Siemens AG. Later the stack was heavily
reworked to better suit the linux networking model, and is now maitained
as an open project partially sponsored by Siemens.

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Sergey Lapin <slapin@ossfans.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 394 insertions, 0 deletions

diff --git a/net/ieee802154/dgram.c b/net/ieee802154/dgram.c
new file mode 100644
index 0000000..1f5ea11
--- /dev/null
+++ b/net/ieee802154/dgram.c
@@ -0,0 +1,394 @@
+/*
+ * ZigBee socket interface
+ *
+ * Copyright 2007, 2008 Siemens AG
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Written by:
+ * Sergey Lapin <slapin@ossfans.org>
+ * Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
+ */
+
+#include <linux/net.h>
+#include <linux/module.h>
+#include <linux/if_arp.h>
+#include <linux/list.h>
+#include <net/sock.h>
+#include <net/ieee802154/af_ieee802154.h>
+#include <net/ieee802154/mac_def.h>
+#include <net/ieee802154/netdevice.h>
+
+#include <asm/ioctls.h>
+
+#include "af802154.h"
+
+static HLIST_HEAD(dgram_head);
+static DEFINE_RWLOCK(dgram_lock);
+
+struct dgram_sock {
+	struct sock sk;
+
+	int bound;
+	struct ieee802154_addr src_addr;
+	struct ieee802154_addr dst_addr;
+};
+
+static inline struct dgram_sock *dgram_sk(const struct sock *sk)
+{
+	return container_of(sk, struct dgram_sock, sk);
+}
+
+
+static void dgram_hash(struct sock *sk)
+{
+	write_lock_bh(&dgram_lock);
+	sk_add_node(sk, &dgram_head);
+	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
+	write_unlock_bh(&dgram_lock);
+}
+
+static void dgram_unhash(struct sock *sk)
+{
+	write_lock_bh(&dgram_lock);
+	if (sk_del_node_init(sk))
+		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
+	write_unlock_bh(&dgram_lock);
+}
+
+static int dgram_init(struct sock *sk)
+{
+	struct dgram_sock *ro = dgram_sk(sk);
+
+	ro->dst_addr.addr_type = IEEE802154_ADDR_LONG;
+	ro->dst_addr.pan_id = 0xffff;
+	memset(&ro->dst_addr.hwaddr, 0xff, sizeof(ro->dst_addr.hwaddr));
+	return 0;
+}
+
+static void dgram_close(struct sock *sk, long timeout)
+{
+	sk_common_release(sk);
+}
+
+static int dgram_bind(struct sock *sk, struct sockaddr *uaddr, int len)
+{
+	struct sockaddr_ieee802154 *addr = (struct sockaddr_ieee802154 *)uaddr;
+	struct dgram_sock *ro = dgram_sk(sk);
+	int err = 0;
+	struct net_device *dev;
+
+	ro->bound = 0;
+
+	if (len < sizeof(*addr))
+		return -EINVAL;
+
+	if (addr->family != AF_IEEE802154)
+		return -EINVAL;
+
+	lock_sock(sk);
+
+	dev = ieee802154_get_dev(sock_net(sk), &addr->addr);
+	if (!dev) {
+		err = -ENODEV;
+		goto out;
+	}
+
+	if (dev->type != ARPHRD_IEEE802154) {
+		err = -ENODEV;
+		goto out_put;
+	}
+
+	memcpy(&ro->src_addr, &addr->addr, sizeof(struct ieee802154_addr));
+
+	ro->bound = 1;
+out_put:
+	dev_put(dev);
+out:
+	release_sock(sk);
+
+	return err;
+}
+
+static int dgram_ioctl(struct sock *sk, int cmd, unsigned long arg)
+{
+	switch (cmd) {
+	case SIOCOUTQ:
+	{
+		int amount = atomic_read(&sk->sk_wmem_alloc);
+		return put_user(amount, (int __user *)arg);
+	}
+
+	case SIOCINQ:
+	{
+		struct sk_buff *skb;
+		unsigned long amount;
+
+		amount = 0;
+		spin_lock_bh(&sk->sk_receive_queue.lock);
+		skb = skb_peek(&sk->sk_receive_queue);
+		if (skb != NULL) {
+			/*
+			 * We will only return the amount
+			 * of this packet since that is all
+			 * that will be read.
+			 */
+			/* FIXME: parse the header for more correct value */
+			amount = skb->len - (3+8+8);
+		}
+		spin_unlock_bh(&sk->sk_receive_queue.lock);
+		return put_user(amount, (int __user *)arg);
+	}
+
+	}
+	return -ENOIOCTLCMD;
+}
+
+/* FIXME: autobind */
+static int dgram_connect(struct sock *sk, struct sockaddr *uaddr,
+			int len)
+{
+	struct sockaddr_ieee802154 *addr = (struct sockaddr_ieee802154 *)uaddr;
+	struct dgram_sock *ro = dgram_sk(sk);
+	int err = 0;
+
+	if (len < sizeof(*addr))
+		return -EINVAL;
+
+	if (addr->family != AF_IEEE802154)
+		return -EINVAL;
+
+	lock_sock(sk);
+
+	if (!ro->bound) {
+		err = -ENETUNREACH;
+		goto out;
+	}
+
+	memcpy(&ro->dst_addr, &addr->addr, sizeof(struct ieee802154_addr));
+
+out:
+	release_sock(sk);
+	return err;
+}
+
+static int dgram_disconnect(struct sock *sk, int flags)
+{
+	struct dgram_sock *ro = dgram_sk(sk);
+
+	lock_sock(sk);
+
+	ro->dst_addr.addr_type = IEEE802154_ADDR_LONG;
+	memset(&ro->dst_addr.hwaddr, 0xff, sizeof(ro->dst_addr.hwaddr));
+
+	release_sock(sk);
+
+	return 0;
+}
+
+static int dgram_sendmsg(struct kiocb *iocb, struct sock *sk,
+		struct msghdr *msg, size_t size)
+{
+	struct net_device *dev;
+	unsigned mtu;
+	struct sk_buff *skb;
+	struct dgram_sock *ro = dgram_sk(sk);
+	int err;
+
+	if (msg->msg_flags & MSG_OOB) {
+		pr_debug("msg->msg_flags = 0x%x\n", msg->msg_flags);
+		return -EOPNOTSUPP;
+	}
+
+	if (!ro->bound)
+		dev = dev_getfirstbyhwtype(sock_net(sk), ARPHRD_IEEE802154);
+	else
+		dev = ieee802154_get_dev(sock_net(sk), &ro->src_addr);
+
+	if (!dev) {
+		pr_debug("no dev\n");
+		err = -ENXIO;
+		goto out;
+	}
+	mtu = dev->mtu;
+	pr_debug("name = %s, mtu = %u\n", dev->name, mtu);
+
+	skb = sock_alloc_send_skb(sk, LL_ALLOCATED_SPACE(dev) + size,
+			msg->msg_flags & MSG_DONTWAIT,
+			&err);
+	if (!skb)
+		goto out_dev;
+
+	skb_reserve(skb, LL_RESERVED_SPACE(dev));
+
+	skb_reset_network_header(skb);
+
+	mac_cb(skb)->flags = IEEE802154_FC_TYPE_DATA | MAC_CB_FLAG_ACKREQ;
+	mac_cb(skb)->seq = ieee802154_mlme_ops(dev)->get_dsn(dev);
+	err = dev_hard_header(skb, dev, ETH_P_IEEE802154, &ro->dst_addr,
+			ro->bound ? &ro->src_addr : NULL, size);
+	if (err < 0)
+		goto out_skb;
+
+	skb_reset_mac_header(skb);
+
+	err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
+	if (err < 0)
+		goto out_skb;
+
+	if (size > mtu) {
+		pr_debug("size = %u, mtu = %u\n", size, mtu);
+		err = -EINVAL;
+		goto out_skb;
+	}
+
+	skb->dev = dev;
+	skb->sk  = sk;
+	skb->protocol = htons(ETH_P_IEEE802154);
+
+	dev_put(dev);
+
+	err = dev_queue_xmit(skb);
+	if (err > 0)
+		err = net_xmit_errno(err);
+
+	return err ?: size;
+
+out_skb:
+	kfree_skb(skb);
+out_dev:
+	dev_put(dev);
+out:
+	return err;
+}
+
+static int dgram_recvmsg(struct kiocb *iocb, struct sock *sk,
+		struct msghdr *msg, size_t len, int noblock, int flags,
+		int *addr_len)
+{
+	size_t copied = 0;
+	int err = -EOPNOTSUPP;
+	struct sk_buff *skb;
+
+	skb = skb_recv_datagram(sk, flags, noblock, &err);
+	if (!skb)
+		goto out;
+
+	copied = skb->len;
+	if (len < copied) {
+		msg->msg_flags |= MSG_TRUNC;
+		copied = len;
+	}
+
+	/* FIXME: skip headers if necessary ?! */
+	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
+	if (err)
+		goto done;
+
+	sock_recv_timestamp(msg, sk, skb);
+
+	if (flags & MSG_TRUNC)
+		copied = skb->len;
+done:
+	skb_free_datagram(sk, skb);
+out:
+	if (err)
+		return err;
+	return copied;
+}
+
+static int dgram_rcv_skb(struct sock *sk, struct sk_buff *skb)
+{
+	if (sock_queue_rcv_skb(sk, skb) < 0) {
+		atomic_inc(&sk->sk_drops);
+		kfree_skb(skb);
+		return NET_RX_DROP;
+	}
+
+	return NET_RX_SUCCESS;
+}
+
+static inline int ieee802154_match_sock(u8 *hw_addr, u16 pan_id,
+		u16 short_addr, struct dgram_sock *ro)
+{
+	if (!ro->bound)
+		return 1;
+
+	if (ro->src_addr.addr_type == IEEE802154_ADDR_LONG &&
+	    !memcmp(ro->src_addr.hwaddr, hw_addr, IEEE802154_ADDR_LEN))
+		return 1;
+
+	if (ro->src_addr.addr_type == IEEE802154_ADDR_SHORT &&
+		     pan_id == ro->src_addr.pan_id &&
+		     short_addr == ro->src_addr.short_addr)
+		return 1;
+
+	return 0;
+}
+
+int ieee802154_dgram_deliver(struct net_device *dev, struct sk_buff *skb)
+{
+	struct sock *sk, *prev = NULL;
+	struct hlist_node *node;
+	int ret = NET_RX_SUCCESS;
+	u16 pan_id, short_addr;
+
+	/* Data frame processing */
+	BUG_ON(dev->type != ARPHRD_IEEE802154);
+
+	pan_id = ieee802154_mlme_ops(dev)->get_pan_id(dev);
+	short_addr = ieee802154_mlme_ops(dev)->get_short_addr(dev);
+
+	read_lock(&dgram_lock);
+	sk_for_each(sk, node, &dgram_head) {
+		if (ieee802154_match_sock(dev->dev_addr, pan_id, short_addr,
+					dgram_sk(sk))) {
+			if (prev) {
+				struct sk_buff *clone;
+				clone = skb_clone(skb, GFP_ATOMIC);
+				if (clone)
+					dgram_rcv_skb(prev, clone);
+			}
+
+			prev = sk;
+		}
+	}
+
+	if (prev)
+		dgram_rcv_skb(prev, skb);
+	else {
+		kfree_skb(skb);
+		ret = NET_RX_DROP;
+	}
+	read_unlock(&dgram_lock);
+
+	return ret;
+}
+
+struct proto ieee802154_dgram_prot = {
+	.name		= "IEEE-802.15.4-MAC",
+	.owner		= THIS_MODULE,
+	.obj_size	= sizeof(struct dgram_sock),
+	.init		= dgram_init,
+	.close		= dgram_close,
+	.bind		= dgram_bind,
+	.sendmsg	= dgram_sendmsg,
+	.recvmsg	= dgram_recvmsg,
+	.hash		= dgram_hash,
+	.unhash		= dgram_unhash,
+	.connect	= dgram_connect,
+	.disconnect	= dgram_disconnect,
+	.ioctl		= dgram_ioctl,
+};
+