x86/kprobes: Fix crash when probing CS CALL instructionsgrafted

When using eBPF to probe CS CALL instructions within a function,
a crash can be triggered.

The eBPF tool probes offset 257 of the __hrtimer_run_queues()
function:

<__hrtimer_run_queues+249>:  nopl   0x0(%rax,%rax,1)
<__hrtimer_run_queues+254>:  mov    %r14,%rdi
<__hrtimer_run_queues+257>:  cs call <__x86_indirect_thunk_r12>
<__hrtimer_run_queues+263>:  mov    %eax,%r12d
<__hrtimer_run_queues+266>:  xchg   %ax,%ax
<__hrtimer_run_queues+268>:  mov    %r13,%rdi

Which triggers this crash:

  BUG: unable to handle page fault for address: 00000000000f41c9
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0002) - not-present page
  PGD 0 P4D 0
  Oops: 0002 [#1] SMP NOPTI
  CPU: 1 PID: 0 Comm: swapper/1 Kdump: loaded Tainted: P
  RIP: 0010:__hrtimer_run_queues+0x106/0x230

Note that __hrtimer_run_queues+0x106 is __hrtimer_run_queues+262, which is
at the 6th byte of the above CS CALL instruction. Since the CS CALL
instruction occupies 6 bytes, the exception occurred in the middle of that
call instruction.

The root cause is that when using eBPF tools to probe in the middle of a
function, a kprobe with INT3 is used as the underlying implementation.

During single-step emulation of the original CALL instruction,
int3_emulate_call() assumes that the probed CALL instruction is 5 bytes
long. However, the actual CS-prefixed CALL instruction occupies 6 bytes,
so it constructs an incorrect exception return address. When the CPU
returns from the kprobe handler, the next instruction to be executed is at
the address of the last byte of that CS CALL instruction. Coincidentally,
starting from that address, the CPU fetches and decodes a completely
different instruction, which ultimately triggers a kernel crash.

Fix the issue by using the actual instruction length obtained from
the instruction decoder when constructing the exception return
address, rather than relying on the hardcoded CALL_INSN_SIZE macro.

[ mingo: Refined the changelog ]

Fixes: 6256e668b7af ("x86/kprobes: Use int3 instead of debug trap for single-step")
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Jinke Han <jinkehan@didiglobal.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000

1 files changed, 1157 insertions, 0 deletions

diff --git a/net/ieee802154/socket.c b/net/ieee802154/socket.c
new file mode 100644
index 000000000..5a36e8789
--- /dev/null
+++ b/net/ieee802154/socket.c
@@ -0,0 +1,1157 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * IEEE802154.4 socket interface
+ *
+ * Copyright 2007, 2008 Siemens AG
+ *
+ * Written by:
+ * Sergey Lapin <slapin@ossfans.org>
+ * Maxim Gorbachyov <maxim.gorbachev@siemens.com>
+ */
+
+#include <linux/net.h>
+#include <linux/capability.h>
+#include <linux/module.h>
+#include <linux/if_arp.h>
+#include <linux/if.h>
+#include <linux/termios.h>	/* For TIOCOUTQ/INQ */
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/socket.h>
+#include <net/datalink.h>
+#include <net/psnap.h>
+#include <net/sock.h>
+#include <net/tcp_states.h>
+#include <net/route.h>
+
+#include <net/af_ieee802154.h>
+#include <net/ieee802154_netdev.h>
+
+/* Utility function for families */
+static struct net_device*
+ieee802154_get_dev(struct net *net, const struct ieee802154_addr *addr)
+{
+	struct net_device *dev = NULL;
+	struct net_device *tmp;
+	__le16 pan_id, short_addr;
+	u8 hwaddr[IEEE802154_ADDR_LEN];
+
+	switch (addr->mode) {
+	case IEEE802154_ADDR_LONG:
+		ieee802154_devaddr_to_raw(hwaddr, addr->extended_addr);
+		rcu_read_lock();
+		dev = dev_getbyhwaddr_rcu(net, ARPHRD_IEEE802154, hwaddr);
+		dev_hold(dev);
+		rcu_read_unlock();
+		break;
+	case IEEE802154_ADDR_SHORT:
+		if (addr->pan_id == cpu_to_le16(IEEE802154_PANID_BROADCAST) ||
+		    addr->short_addr == cpu_to_le16(IEEE802154_ADDR_UNDEF) ||
+		    addr->short_addr == cpu_to_le16(IEEE802154_ADDR_BROADCAST))
+			break;
+
+		rtnl_lock();
+
+		for_each_netdev(net, tmp) {
+			if (tmp->type != ARPHRD_IEEE802154)
+				continue;
+
+			pan_id = tmp->ieee802154_ptr->pan_id;
+			short_addr = tmp->ieee802154_ptr->short_addr;
+			if (pan_id == addr->pan_id &&
+			    short_addr == addr->short_addr) {
+				dev = tmp;
+				dev_hold(dev);
+				break;
+			}
+		}
+
+		rtnl_unlock();
+		break;
+	default:
+		pr_warn("Unsupported ieee802154 address type: %d\n",
+			addr->mode);
+		break;
+	}
+
+	return dev;
+}
+
+static int ieee802154_sock_release(struct socket *sock)
+{
+	struct sock *sk = sock->sk;
+
+	if (sk) {
+		sock->sk = NULL;
+		sk->sk_prot->close(sk, 0);
+	}
+	return 0;
+}
+
+static int ieee802154_sock_sendmsg(struct socket *sock, struct msghdr *msg,
+				   size_t len)
+{
+	struct sock *sk = sock->sk;
+
+	return sk->sk_prot->sendmsg(sk, msg, len);
+}
+
+static int ieee802154_sock_bind(struct socket *sock, struct sockaddr_unsized *uaddr,
+				int addr_len)
+{
+	struct sock *sk = sock->sk;
+
+	if (sk->sk_prot->bind)
+		return sk->sk_prot->bind(sk, uaddr, addr_len);
+
+	return sock_no_bind(sock, uaddr, addr_len);
+}
+
+static int ieee802154_sock_connect(struct socket *sock, struct sockaddr_unsized *uaddr,
+				   int addr_len, int flags)
+{
+	struct sock *sk = sock->sk;
+
+	if (addr_len < sizeof(uaddr->sa_family))
+		return -EINVAL;
+
+	if (uaddr->sa_family == AF_UNSPEC)
+		return sk->sk_prot->disconnect(sk, flags);
+
+	return sk->sk_prot->connect(sk, uaddr, addr_len);
+}
+
+static int ieee802154_dev_ioctl(struct sock *sk, struct ifreq __user *arg,
+				unsigned int cmd)
+{
+	struct ifreq ifr;
+	int ret = -ENOIOCTLCMD;
+	struct net_device *dev;
+
+	if (get_user_ifreq(&ifr, NULL, arg))
+		return -EFAULT;
+
+	ifr.ifr_name[IFNAMSIZ-1] = 0;
+
+	dev_load(sock_net(sk), ifr.ifr_name);
+	dev = dev_get_by_name(sock_net(sk), ifr.ifr_name);
+
+	if (!dev)
+		return -ENODEV;
+
+	if (dev->type == ARPHRD_IEEE802154 && dev->netdev_ops->ndo_do_ioctl)
+		ret = dev->netdev_ops->ndo_do_ioctl(dev, &ifr, cmd);
+
+	if (!ret && put_user_ifreq(&ifr, arg))
+		ret = -EFAULT;
+	dev_put(dev);
+
+	return ret;
+}
+
+static int ieee802154_sock_ioctl(struct socket *sock, unsigned int cmd,
+				 unsigned long arg)
+{
+	struct sock *sk = sock->sk;
+
+	switch (cmd) {
+	case SIOCGIFADDR:
+	case SIOCSIFADDR:
+		return ieee802154_dev_ioctl(sk, (struct ifreq __user *)arg,
+				cmd);
+	default:
+		if (!sk->sk_prot->ioctl)
+			return -ENOIOCTLCMD;
+		return sk_ioctl(sk, cmd, (void __user *)arg);
+	}
+}
+
+/* RAW Sockets (802.15.4 created in userspace) */
+static HLIST_HEAD(raw_head);
+static DEFINE_RWLOCK(raw_lock);
+
+static int raw_hash(struct sock *sk)
+{
+	write_lock_bh(&raw_lock);
+	sk_add_node(sk, &raw_head);
+	write_unlock_bh(&raw_lock);
+	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
+
+	return 0;
+}
+
+static void raw_unhash(struct sock *sk)
+{
+	write_lock_bh(&raw_lock);
+	if (sk_del_node_init(sk))
+		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
+	write_unlock_bh(&raw_lock);
+}
+
+static void raw_close(struct sock *sk, long timeout)
+{
+	sk_common_release(sk);
+}
+
+static int raw_bind(struct sock *sk, struct sockaddr_unsized *_uaddr, int len)
+{
+	struct ieee802154_addr addr;
+	struct sockaddr_ieee802154 *uaddr = (struct sockaddr_ieee802154 *)_uaddr;
+	int err = 0;
+	struct net_device *dev = NULL;
+
+	err = ieee802154_sockaddr_check_size(uaddr, len);
+	if (err < 0)
+		return err;
+
+	uaddr = (struct sockaddr_ieee802154 *)_uaddr;
+	if (uaddr->family != AF_IEEE802154)
+		return -EINVAL;
+
+	lock_sock(sk);
+
+	ieee802154_addr_from_sa(&addr, &uaddr->addr);
+	dev = ieee802154_get_dev(sock_net(sk), &addr);
+	if (!dev) {
+		err = -ENODEV;
+		goto out;
+	}
+
+	sk->sk_bound_dev_if = dev->ifindex;
+	sk_dst_reset(sk);
+
+	dev_put(dev);
+out:
+	release_sock(sk);
+
+	return err;
+}
+
+static int raw_connect(struct sock *sk, struct sockaddr_unsized *uaddr,
+		       int addr_len)
+{
+	return -ENOTSUPP;
+}
+
+static int raw_disconnect(struct sock *sk, int flags)
+{
+	return 0;
+}
+
+static int raw_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
+{
+	struct net_device *dev;
+	unsigned int mtu;
+	struct sk_buff *skb;
+	int hlen, tlen;
+	int err;
+
+	if (msg->msg_flags & MSG_OOB) {
+		pr_debug("msg->msg_flags = 0x%x\n", msg->msg_flags);
+		return -EOPNOTSUPP;
+	}
+
+	lock_sock(sk);
+	if (!sk->sk_bound_dev_if)
+		dev = dev_getfirstbyhwtype(sock_net(sk), ARPHRD_IEEE802154);
+	else
+		dev = dev_get_by_index(sock_net(sk), sk->sk_bound_dev_if);
+	release_sock(sk);
+
+	if (!dev) {
+		pr_debug("no dev\n");
+		err = -ENXIO;
+		goto out;
+	}
+
+	mtu = IEEE802154_MTU;
+	pr_debug("name = %s, mtu = %u\n", dev->name, mtu);
+
+	if (size > mtu) {
+		pr_debug("size = %zu, mtu = %u\n", size, mtu);
+		err = -EMSGSIZE;
+		goto out_dev;
+	}
+	if (!size) {
+		err = 0;
+		goto out_dev;
+	}
+
+	hlen = LL_RESERVED_SPACE(dev);
+	tlen = dev->needed_tailroom;
+	skb = sock_alloc_send_skb(sk, hlen + tlen + size,
+				  msg->msg_flags & MSG_DONTWAIT, &err);
+	if (!skb)
+		goto out_dev;
+
+	skb_reserve(skb, hlen);
+
+	skb_reset_mac_header(skb);
+	skb_reset_network_header(skb);
+
+	err = memcpy_from_msg(skb_put(skb, size), msg, size);
+	if (err < 0)
+		goto out_skb;
+
+	skb->dev = dev;
+	skb->protocol = htons(ETH_P_IEEE802154);
+
+	err = dev_queue_xmit(skb);
+	if (err > 0)
+		err = net_xmit_errno(err);
+
+	dev_put(dev);
+
+	return err ?: size;
+
+out_skb:
+	kfree_skb(skb);
+out_dev:
+	dev_put(dev);
+out:
+	return err;
+}
+
+static int raw_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
+		       int flags)
+{
+	size_t copied = 0;
+	int err = -EOPNOTSUPP;
+	struct sk_buff *skb;
+
+	skb = skb_recv_datagram(sk, flags, &err);
+	if (!skb)
+		goto out;
+
+	copied = skb->len;
+	if (len < copied) {
+		msg->msg_flags |= MSG_TRUNC;
+		copied = len;
+	}
+
+	err = skb_copy_datagram_msg(skb, 0, msg, copied);
+	if (err)
+		goto done;
+
+	sock_recv_cmsgs(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 raw_rcv_skb(struct sock *sk, struct sk_buff *skb)
+{
+	skb = skb_share_check(skb, GFP_ATOMIC);
+	if (!skb)
+		return NET_RX_DROP;
+
+	if (sock_queue_rcv_skb(sk, skb) < 0) {
+		kfree_skb(skb);
+		return NET_RX_DROP;
+	}
+
+	return NET_RX_SUCCESS;
+}
+
+static void ieee802154_raw_deliver(struct net_device *dev, struct sk_buff *skb)
+{
+	struct sock *sk;
+
+	read_lock(&raw_lock);
+	sk_for_each(sk, &raw_head) {
+		bh_lock_sock(sk);
+		if (!sk->sk_bound_dev_if ||
+		    sk->sk_bound_dev_if == dev->ifindex) {
+			struct sk_buff *clone;
+
+			clone = skb_clone(skb, GFP_ATOMIC);
+			if (clone)
+				raw_rcv_skb(sk, clone);
+		}
+		bh_unlock_sock(sk);
+	}
+	read_unlock(&raw_lock);
+}
+
+static int raw_getsockopt(struct sock *sk, int level, int optname,
+			  char __user *optval, int __user *optlen)
+{
+	return -EOPNOTSUPP;
+}
+
+static int raw_setsockopt(struct sock *sk, int level, int optname,
+			  sockptr_t optval, unsigned int optlen)
+{
+	return -EOPNOTSUPP;
+}
+
+static struct proto ieee802154_raw_prot = {
+	.name		= "IEEE-802.15.4-RAW",
+	.owner		= THIS_MODULE,
+	.obj_size	= sizeof(struct sock),
+	.close		= raw_close,
+	.bind		= raw_bind,
+	.sendmsg	= raw_sendmsg,
+	.recvmsg	= raw_recvmsg,
+	.hash		= raw_hash,
+	.unhash		= raw_unhash,
+	.connect	= raw_connect,
+	.disconnect	= raw_disconnect,
+	.getsockopt	= raw_getsockopt,
+	.setsockopt	= raw_setsockopt,
+};
+
+static const struct proto_ops ieee802154_raw_ops = {
+	.family		   = PF_IEEE802154,
+	.owner		   = THIS_MODULE,
+	.release	   = ieee802154_sock_release,
+	.bind		   = ieee802154_sock_bind,
+	.connect	   = ieee802154_sock_connect,
+	.socketpair	   = sock_no_socketpair,
+	.accept		   = sock_no_accept,
+	.getname	   = sock_no_getname,
+	.poll		   = datagram_poll,
+	.ioctl		   = ieee802154_sock_ioctl,
+	.gettstamp	   = sock_gettstamp,
+	.listen		   = sock_no_listen,
+	.shutdown	   = sock_no_shutdown,
+	.setsockopt	   = sock_common_setsockopt,
+	.getsockopt	   = sock_common_getsockopt,
+	.sendmsg	   = ieee802154_sock_sendmsg,
+	.recvmsg	   = sock_common_recvmsg,
+	.mmap		   = sock_no_mmap,
+};
+
+/* DGRAM Sockets (802.15.4 dataframes) */
+static HLIST_HEAD(dgram_head);
+static DEFINE_RWLOCK(dgram_lock);
+
+struct dgram_sock {
+	struct sock sk;
+
+	struct ieee802154_addr src_addr;
+	struct ieee802154_addr dst_addr;
+
+	unsigned int bound:1;
+	unsigned int connected:1;
+	unsigned int want_ack:1;
+	unsigned int want_lqi:1;
+	unsigned int secen:1;
+	unsigned int secen_override:1;
+	unsigned int seclevel:3;
+	unsigned int seclevel_override:1;
+};
+
+static inline struct dgram_sock *dgram_sk(const struct sock *sk)
+{
+	return container_of(sk, struct dgram_sock, sk);
+}
+
+static int dgram_hash(struct sock *sk)
+{
+	write_lock_bh(&dgram_lock);
+	sk_add_node(sk, &dgram_head);
+	write_unlock_bh(&dgram_lock);
+	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
+
+	return 0;
+}
+
+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->want_ack = 1;
+	ro->want_lqi = 0;
+	return 0;
+}
+
+static void dgram_close(struct sock *sk, long timeout)
+{
+	sk_common_release(sk);
+}
+
+static int dgram_bind(struct sock *sk, struct sockaddr_unsized *uaddr, int len)
+{
+	struct sockaddr_ieee802154 *addr = (struct sockaddr_ieee802154 *)uaddr;
+	struct ieee802154_addr haddr;
+	struct dgram_sock *ro = dgram_sk(sk);
+	int err = -EINVAL;
+	struct net_device *dev;
+
+	lock_sock(sk);
+
+	ro->bound = 0;
+
+	err = ieee802154_sockaddr_check_size(addr, len);
+	if (err < 0)
+		goto out;
+
+	if (addr->family != AF_IEEE802154) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	ieee802154_addr_from_sa(&haddr, &addr->addr);
+	dev = ieee802154_get_dev(sock_net(sk), &haddr);
+	if (!dev) {
+		err = -ENODEV;
+		goto out;
+	}
+
+	if (dev->type != ARPHRD_IEEE802154) {
+		err = -ENODEV;
+		goto out_put;
+	}
+
+	ro->src_addr = haddr;
+
+	ro->bound = 1;
+	err = 0;
+out_put:
+	dev_put(dev);
+out:
+	release_sock(sk);
+
+	return err;
+}
+
+static int dgram_ioctl(struct sock *sk, int cmd, int *karg)
+{
+	switch (cmd) {
+	case SIOCOUTQ:
+	{
+		*karg = sk_wmem_alloc_get(sk);
+
+		return 0;
+	}
+
+	case SIOCINQ:
+	{
+		struct sk_buff *skb;
+
+		*karg = 0;
+		spin_lock_bh(&sk->sk_receive_queue.lock);
+		skb = skb_peek(&sk->sk_receive_queue);
+		if (skb) {
+			/* We will only return the amount
+			 * of this packet since that is all
+			 * that will be read.
+			 */
+			*karg = skb->len - ieee802154_hdr_length(skb);
+		}
+		spin_unlock_bh(&sk->sk_receive_queue.lock);
+		return 0;
+	}
+	}
+
+	return -ENOIOCTLCMD;
+}
+
+/* FIXME: autobind */
+static int dgram_connect(struct sock *sk, struct sockaddr_unsized *uaddr,
+			 int len)
+{
+	struct sockaddr_ieee802154 *addr = (struct sockaddr_ieee802154 *)uaddr;
+	struct dgram_sock *ro = dgram_sk(sk);
+	int err = 0;
+
+	err = ieee802154_sockaddr_check_size(addr, len);
+	if (err < 0)
+		return err;
+
+	if (addr->family != AF_IEEE802154)
+		return -EINVAL;
+
+	lock_sock(sk);
+
+	if (!ro->bound) {
+		err = -ENETUNREACH;
+		goto out;
+	}
+
+	ieee802154_addr_from_sa(&ro->dst_addr, &addr->addr);
+	ro->connected = 1;
+
+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->connected = 0;
+	release_sock(sk);
+
+	return 0;
+}
+
+static int dgram_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
+{
+	struct net_device *dev;
+	unsigned int mtu;
+	struct sk_buff *skb;
+	struct ieee802154_mac_cb *cb;
+	struct dgram_sock *ro = dgram_sk(sk);
+	struct ieee802154_addr dst_addr;
+	DECLARE_SOCKADDR(struct sockaddr_ieee802154*, daddr, msg->msg_name);
+	int hlen, tlen;
+	int err;
+
+	if (msg->msg_flags & MSG_OOB) {
+		pr_debug("msg->msg_flags = 0x%x\n", msg->msg_flags);
+		return -EOPNOTSUPP;
+	}
+
+	if (msg->msg_name) {
+		if (ro->connected)
+			return -EISCONN;
+		if (msg->msg_namelen < IEEE802154_MIN_NAMELEN)
+			return -EINVAL;
+		err = ieee802154_sockaddr_check_size(daddr, msg->msg_namelen);
+		if (err < 0)
+			return err;
+		ieee802154_addr_from_sa(&dst_addr, &daddr->addr);
+	} else {
+		if (!ro->connected)
+			return -EDESTADDRREQ;
+		dst_addr = ro->dst_addr;
+	}
+
+	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 = IEEE802154_MTU;
+	pr_debug("name = %s, mtu = %u\n", dev->name, mtu);
+
+	if (size > mtu) {
+		pr_debug("size = %zu, mtu = %u\n", size, mtu);
+		err = -EMSGSIZE;
+		goto out_dev;
+	}
+
+	hlen = LL_RESERVED_SPACE(dev);
+	tlen = dev->needed_tailroom;
+	skb = sock_alloc_send_skb(sk, hlen + tlen + size,
+				  msg->msg_flags & MSG_DONTWAIT,
+				  &err);
+	if (!skb)
+		goto out_dev;
+
+	skb_reserve(skb, hlen);
+
+	skb_reset_network_header(skb);
+
+	cb = mac_cb_init(skb);
+	cb->type = IEEE802154_FC_TYPE_DATA;
+	cb->ackreq = ro->want_ack;
+	cb->secen = ro->secen;
+	cb->secen_override = ro->secen_override;
+	cb->seclevel = ro->seclevel;
+	cb->seclevel_override = ro->seclevel_override;
+
+	err = wpan_dev_hard_header(skb, dev, &dst_addr,
+				   ro->bound ? &ro->src_addr : NULL, size);
+	if (err < 0)
+		goto out_skb;
+
+	err = memcpy_from_msg(skb_put(skb, size), msg, size);
+	if (err < 0)
+		goto out_skb;
+
+	skb->dev = dev;
+	skb->protocol = htons(ETH_P_IEEE802154);
+
+	err = dev_queue_xmit(skb);
+	if (err > 0)
+		err = net_xmit_errno(err);
+
+	dev_put(dev);
+
+	return err ?: size;
+
+out_skb:
+	kfree_skb(skb);
+out_dev:
+	dev_put(dev);
+out:
+	return err;
+}
+
+static int dgram_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
+			 int flags)
+{
+	size_t copied = 0;
+	int err = -EOPNOTSUPP;
+	struct sk_buff *skb;
+	struct dgram_sock *ro = dgram_sk(sk);
+	DECLARE_SOCKADDR(struct sockaddr_ieee802154 *, saddr, msg->msg_name);
+
+	skb = skb_recv_datagram(sk, flags, &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_msg(skb, 0, msg, copied);
+	if (err)
+		goto done;
+
+	sock_recv_cmsgs(msg, sk, skb);
+
+	if (saddr) {
+		/* Clear the implicit padding in struct sockaddr_ieee802154
+		 * (16 bits between 'family' and 'addr') and in struct
+		 * ieee802154_addr_sa (16 bits at the end of the structure).
+		 */
+		memset(saddr, 0, sizeof(*saddr));
+
+		saddr->family = AF_IEEE802154;
+		ieee802154_addr_to_sa(&saddr->addr, &mac_cb(skb)->source);
+		msg->msg_namelen = sizeof(*saddr);
+	}
+
+	if (ro->want_lqi) {
+		err = put_cmsg(msg, SOL_IEEE802154, WPAN_WANTLQI,
+			       sizeof(uint8_t), &(mac_cb(skb)->lqi));
+		if (err)
+			goto done;
+	}
+
+	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)
+{
+	skb = skb_share_check(skb, GFP_ATOMIC);
+	if (!skb)
+		return NET_RX_DROP;
+
+	if (sock_queue_rcv_skb(sk, skb) < 0) {
+		kfree_skb(skb);
+		return NET_RX_DROP;
+	}
+
+	return NET_RX_SUCCESS;
+}
+
+static inline bool
+ieee802154_match_sock(__le64 hw_addr, __le16 pan_id, __le16 short_addr,
+		      struct dgram_sock *ro)
+{
+	if (!ro->bound)
+		return true;
+
+	if (ro->src_addr.mode == IEEE802154_ADDR_LONG &&
+	    hw_addr == ro->src_addr.extended_addr)
+		return true;
+
+	if (ro->src_addr.mode == IEEE802154_ADDR_SHORT &&
+	    pan_id == ro->src_addr.pan_id &&
+	    short_addr == ro->src_addr.short_addr)
+		return true;
+
+	return false;
+}
+
+static int ieee802154_dgram_deliver(struct net_device *dev, struct sk_buff *skb)
+{
+	struct sock *sk, *prev = NULL;
+	int ret = NET_RX_SUCCESS;
+	__le16 pan_id, short_addr;
+	__le64 hw_addr;
+
+	/* Data frame processing */
+	BUG_ON(dev->type != ARPHRD_IEEE802154);
+
+	pan_id = dev->ieee802154_ptr->pan_id;
+	short_addr = dev->ieee802154_ptr->short_addr;
+	hw_addr = dev->ieee802154_ptr->extended_addr;
+
+	read_lock(&dgram_lock);
+	sk_for_each(sk, &dgram_head) {
+		if (ieee802154_match_sock(hw_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;
+}
+
+static int do_dgram_getsockopt(struct sock *sk, int optname, sockopt_t *opt)
+{
+	struct dgram_sock *ro = dgram_sk(sk);
+	int val, len;
+
+	len = umin(sizeof(int), opt->optlen);
+
+	switch (optname) {
+	case WPAN_WANTACK:
+		val = ro->want_ack;
+		break;
+	case WPAN_WANTLQI:
+		val = ro->want_lqi;
+		break;
+	case WPAN_SECURITY:
+		if (!ro->secen_override)
+			val = WPAN_SECURITY_DEFAULT;
+		else if (ro->secen)
+			val = WPAN_SECURITY_ON;
+		else
+			val = WPAN_SECURITY_OFF;
+		break;
+	case WPAN_SECURITY_LEVEL:
+		if (!ro->seclevel_override)
+			val = WPAN_SECURITY_LEVEL_DEFAULT;
+		else
+			val = ro->seclevel;
+		break;
+	default:
+		return -ENOPROTOOPT;
+	}
+
+	opt->optlen = len;
+	if (copy_to_iter(&val, len, &opt->iter_out) != len)
+		return -EFAULT;
+	return 0;
+}
+
+static int dgram_getsockopt(struct sock *sk, int level, int optname,
+			    char __user *optval, int __user *optlen)
+{
+	sockopt_t opt;
+	int err;
+
+	if (level != SOL_IEEE802154)
+		return -EOPNOTSUPP;
+
+	err = sockopt_init_user(&opt, optval, optlen);
+	if (err)
+		return err;
+
+	err = do_dgram_getsockopt(sk, optname, &opt);
+	if (err)
+		return err;
+
+	if (put_user(opt.optlen, optlen))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int dgram_setsockopt(struct sock *sk, int level, int optname,
+			    sockptr_t optval, unsigned int optlen)
+{
+	struct dgram_sock *ro = dgram_sk(sk);
+	struct net *net = sock_net(sk);
+	int val;
+	int err = 0;
+
+	if (optlen < sizeof(int))
+		return -EINVAL;
+
+	if (copy_from_sockptr(&val, optval, sizeof(int)))
+		return -EFAULT;
+
+	lock_sock(sk);
+
+	switch (optname) {
+	case WPAN_WANTACK:
+		ro->want_ack = !!val;
+		break;
+	case WPAN_WANTLQI:
+		ro->want_lqi = !!val;
+		break;
+	case WPAN_SECURITY:
+		if (!ns_capable(net->user_ns, CAP_NET_ADMIN) &&
+		    !ns_capable(net->user_ns, CAP_NET_RAW)) {
+			err = -EPERM;
+			break;
+		}
+
+		switch (val) {
+		case WPAN_SECURITY_DEFAULT:
+			ro->secen_override = 0;
+			break;
+		case WPAN_SECURITY_ON:
+			ro->secen_override = 1;
+			ro->secen = 1;
+			break;
+		case WPAN_SECURITY_OFF:
+			ro->secen_override = 1;
+			ro->secen = 0;
+			break;
+		default:
+			err = -EINVAL;
+			break;
+		}
+		break;
+	case WPAN_SECURITY_LEVEL:
+		if (!ns_capable(net->user_ns, CAP_NET_ADMIN) &&
+		    !ns_capable(net->user_ns, CAP_NET_RAW)) {
+			err = -EPERM;
+			break;
+		}
+
+		if (val < WPAN_SECURITY_LEVEL_DEFAULT ||
+		    val > IEEE802154_SCF_SECLEVEL_ENC_MIC128) {
+			err = -EINVAL;
+		} else if (val == WPAN_SECURITY_LEVEL_DEFAULT) {
+			ro->seclevel_override = 0;
+		} else {
+			ro->seclevel_override = 1;
+			ro->seclevel = val;
+		}
+		break;
+	default:
+		err = -ENOPROTOOPT;
+		break;
+	}
+
+	release_sock(sk);
+	return err;
+}
+
+static 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,
+	.getsockopt	= dgram_getsockopt,
+	.setsockopt	= dgram_setsockopt,
+};
+
+static const struct proto_ops ieee802154_dgram_ops = {
+	.family		   = PF_IEEE802154,
+	.owner		   = THIS_MODULE,
+	.release	   = ieee802154_sock_release,
+	.bind		   = ieee802154_sock_bind,
+	.connect	   = ieee802154_sock_connect,
+	.socketpair	   = sock_no_socketpair,
+	.accept		   = sock_no_accept,
+	.getname	   = sock_no_getname,
+	.poll		   = datagram_poll,
+	.ioctl		   = ieee802154_sock_ioctl,
+	.gettstamp	   = sock_gettstamp,
+	.listen		   = sock_no_listen,
+	.shutdown	   = sock_no_shutdown,
+	.setsockopt	   = sock_common_setsockopt,
+	.getsockopt	   = sock_common_getsockopt,
+	.sendmsg	   = ieee802154_sock_sendmsg,
+	.recvmsg	   = sock_common_recvmsg,
+	.mmap		   = sock_no_mmap,
+};
+
+static void ieee802154_sock_destruct(struct sock *sk)
+{
+	skb_queue_purge(&sk->sk_receive_queue);
+}
+
+/* Create a socket. Initialise the socket, blank the addresses
+ * set the state.
+ */
+static int ieee802154_create(struct net *net, struct socket *sock,
+			     int protocol, int kern)
+{
+	struct sock *sk;
+	int rc;
+	struct proto *proto;
+	const struct proto_ops *ops;
+
+	if (!net_eq(net, &init_net))
+		return -EAFNOSUPPORT;
+
+	switch (sock->type) {
+	case SOCK_RAW:
+		rc = -EPERM;
+		if (!capable(CAP_NET_RAW))
+			goto out;
+		proto = &ieee802154_raw_prot;
+		ops = &ieee802154_raw_ops;
+		break;
+	case SOCK_DGRAM:
+		proto = &ieee802154_dgram_prot;
+		ops = &ieee802154_dgram_ops;
+		break;
+	default:
+		rc = -ESOCKTNOSUPPORT;
+		goto out;
+	}
+
+	rc = -ENOMEM;
+	sk = sk_alloc(net, PF_IEEE802154, GFP_KERNEL, proto, kern);
+	if (!sk)
+		goto out;
+	rc = 0;
+
+	sock->ops = ops;
+
+	sock_init_data(sock, sk);
+	sk->sk_destruct = ieee802154_sock_destruct;
+	sk->sk_family = PF_IEEE802154;
+
+	/* Checksums on by default */
+	sock_set_flag(sk, SOCK_ZAPPED);
+
+	if (sk->sk_prot->hash) {
+		rc = sk->sk_prot->hash(sk);
+		if (rc)
+			goto out_sk_release;
+	}
+
+	if (sk->sk_prot->init) {
+		rc = sk->sk_prot->init(sk);
+		if (rc)
+			goto out_sk_release;
+	}
+out:
+	return rc;
+out_sk_release:
+	sk_common_release(sk);
+	sock->sk = NULL;
+	goto out;
+}
+
+static const struct net_proto_family ieee802154_family_ops = {
+	.family		= PF_IEEE802154,
+	.create		= ieee802154_create,
+	.owner		= THIS_MODULE,
+};
+
+static int ieee802154_rcv(struct sk_buff *skb, struct net_device *dev,
+			  struct packet_type *pt, struct net_device *orig_dev)
+{
+	if (!netif_running(dev))
+		goto drop;
+	pr_debug("got frame, type %d, dev %p\n", dev->type, dev);
+#ifdef DEBUG
+	print_hex_dump_bytes("ieee802154_rcv ",
+			     DUMP_PREFIX_NONE, skb->data, skb->len);
+#endif
+
+	if (!net_eq(dev_net(dev), &init_net))
+		goto drop;
+
+	ieee802154_raw_deliver(dev, skb);
+
+	if (dev->type != ARPHRD_IEEE802154)
+		goto drop;
+
+	if (skb->pkt_type != PACKET_OTHERHOST)
+		return ieee802154_dgram_deliver(dev, skb);
+
+drop:
+	kfree_skb(skb);
+	return NET_RX_DROP;
+}
+
+static struct packet_type ieee802154_packet_type = {
+	.type = htons(ETH_P_IEEE802154),
+	.func = ieee802154_rcv,
+};
+
+static int __init af_ieee802154_init(void)
+{
+	int rc;
+
+	rc = proto_register(&ieee802154_raw_prot, 1);
+	if (rc)
+		goto out;
+
+	rc = proto_register(&ieee802154_dgram_prot, 1);
+	if (rc)
+		goto err_dgram;
+
+	/* Tell SOCKET that we are alive */
+	rc = sock_register(&ieee802154_family_ops);
+	if (rc)
+		goto err_sock;
+	dev_add_pack(&ieee802154_packet_type);
+
+	rc = 0;
+	goto out;
+
+err_sock:
+	proto_unregister(&ieee802154_dgram_prot);
+err_dgram:
+	proto_unregister(&ieee802154_raw_prot);
+out:
+	return rc;
+}
+
+static void __exit af_ieee802154_remove(void)
+{
+	dev_remove_pack(&ieee802154_packet_type);
+	sock_unregister(PF_IEEE802154);
+	proto_unregister(&ieee802154_dgram_prot);
+	proto_unregister(&ieee802154_raw_prot);
+}
+
+module_init(af_ieee802154_init);
+module_exit(af_ieee802154_remove);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("IEEE 802.15.4 socket interface");
+MODULE_ALIAS_NETPROTO(PF_IEEE802154);