Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1308 insertions, 0 deletions

diff --git a/net/llc/af_llc.c b/net/llc/af_llc.c
new file mode 100644
index 0000000000..20551cfb7d
--- /dev/null
+++ b/net/llc/af_llc.c
@@ -0,0 +1,1308 @@
+/*
+ * af_llc.c - LLC User Interface SAPs
+ * Description:
+ *   Functions in this module are implementation of socket based llc
+ *   communications for the Linux operating system. Support of llc class
+ *   one and class two is provided via SOCK_DGRAM and SOCK_STREAM
+ *   respectively.
+ *
+ *   An llc2 connection is (mac + sap), only one llc2 sap connection
+ *   is allowed per mac. Though one sap may have multiple mac + sap
+ *   connections.
+ *
+ * Copyright (c) 2001 by Jay Schulist <jschlst@samba.org>
+ *		 2002-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
+ *
+ * This program can be redistributed or modified under the terms of the
+ * GNU General Public License as published by the Free Software Foundation.
+ * This program is distributed without any warranty or implied warranty
+ * of merchantability or fitness for a particular purpose.
+ *
+ * See the GNU General Public License for more details.
+ */
+#include <linux/compiler.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/rtnetlink.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/sched/signal.h>
+
+#include <net/llc.h>
+#include <net/llc_sap.h>
+#include <net/llc_pdu.h>
+#include <net/llc_conn.h>
+#include <net/tcp_states.h>
+
+/* remember: uninitialized global data is zeroed because its in .bss */
+static u16 llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
+static u16 llc_ui_sap_link_no_max[256];
+static struct sockaddr_llc llc_ui_addrnull;
+static const struct proto_ops llc_ui_ops;
+
+static bool llc_ui_wait_for_conn(struct sock *sk, long timeout);
+static int llc_ui_wait_for_disc(struct sock *sk, long timeout);
+static int llc_ui_wait_for_busy_core(struct sock *sk, long timeout);
+
+#if 0
+#define dprintk(args...) printk(KERN_DEBUG args)
+#else
+#define dprintk(args...) do {} while (0)
+#endif
+
+/* Maybe we'll add some more in the future. */
+#define LLC_CMSG_PKTINFO	1
+
+
+/**
+ *	llc_ui_next_link_no - return the next unused link number for a sap
+ *	@sap: Address of sap to get link number from.
+ *
+ *	Return the next unused link number for a given sap.
+ */
+static inline u16 llc_ui_next_link_no(int sap)
+{
+	return llc_ui_sap_link_no_max[sap]++;
+}
+
+/**
+ *	llc_proto_type - return eth protocol for ARP header type
+ *	@arphrd: ARP header type.
+ *
+ *	Given an ARP header type return the corresponding ethernet protocol.
+ */
+static inline __be16 llc_proto_type(u16 arphrd)
+{
+	return htons(ETH_P_802_2);
+}
+
+/**
+ *	llc_ui_addr_null - determines if a address structure is null
+ *	@addr: Address to test if null.
+ */
+static inline u8 llc_ui_addr_null(struct sockaddr_llc *addr)
+{
+	return !memcmp(addr, &llc_ui_addrnull, sizeof(*addr));
+}
+
+/**
+ *	llc_ui_header_len - return length of llc header based on operation
+ *	@sk: Socket which contains a valid llc socket type.
+ *	@addr: Complete sockaddr_llc structure received from the user.
+ *
+ *	Provide the length of the llc header depending on what kind of
+ *	operation the user would like to perform and the type of socket.
+ *	Returns the correct llc header length.
+ */
+static inline u8 llc_ui_header_len(struct sock *sk, struct sockaddr_llc *addr)
+{
+	u8 rc = LLC_PDU_LEN_U;
+
+	if (addr->sllc_test)
+		rc = LLC_PDU_LEN_U;
+	else if (addr->sllc_xid)
+		/* We need to expand header to sizeof(struct llc_xid_info)
+		 * since llc_pdu_init_as_xid_cmd() sets 4,5,6 bytes of LLC header
+		 * as XID PDU. In llc_ui_sendmsg() we reserved header size and then
+		 * filled all other space with user data. If we won't reserve this
+		 * bytes, llc_pdu_init_as_xid_cmd() will overwrite user data
+		 */
+		rc = LLC_PDU_LEN_U_XID;
+	else if (sk->sk_type == SOCK_STREAM)
+		rc = LLC_PDU_LEN_I;
+	return rc;
+}
+
+/**
+ *	llc_ui_send_data - send data via reliable llc2 connection
+ *	@sk: Connection the socket is using.
+ *	@skb: Data the user wishes to send.
+ *	@noblock: can we block waiting for data?
+ *
+ *	Send data via reliable llc2 connection.
+ *	Returns 0 upon success, non-zero if action did not succeed.
+ *
+ *	This function always consumes a reference to the skb.
+ */
+static int llc_ui_send_data(struct sock* sk, struct sk_buff *skb, int noblock)
+{
+	struct llc_sock* llc = llc_sk(sk);
+
+	if (unlikely(llc_data_accept_state(llc->state) ||
+		     llc->remote_busy_flag ||
+		     llc->p_flag)) {
+		long timeout = sock_sndtimeo(sk, noblock);
+		int rc;
+
+		rc = llc_ui_wait_for_busy_core(sk, timeout);
+		if (rc) {
+			kfree_skb(skb);
+			return rc;
+		}
+	}
+	return llc_build_and_send_pkt(sk, skb);
+}
+
+static void llc_ui_sk_init(struct socket *sock, struct sock *sk)
+{
+	sock_graft(sk, sock);
+	sk->sk_type	= sock->type;
+	sock->ops	= &llc_ui_ops;
+}
+
+static struct proto llc_proto = {
+	.name	  = "LLC",
+	.owner	  = THIS_MODULE,
+	.obj_size = sizeof(struct llc_sock),
+	.slab_flags = SLAB_TYPESAFE_BY_RCU,
+};
+
+/**
+ *	llc_ui_create - alloc and init a new llc_ui socket
+ *	@net: network namespace (must be default network)
+ *	@sock: Socket to initialize and attach allocated sk to.
+ *	@protocol: Unused.
+ *	@kern: on behalf of kernel or userspace
+ *
+ *	Allocate and initialize a new llc_ui socket, validate the user wants a
+ *	socket type we have available.
+ *	Returns 0 upon success, negative upon failure.
+ */
+static int llc_ui_create(struct net *net, struct socket *sock, int protocol,
+			 int kern)
+{
+	struct sock *sk;
+	int rc = -ESOCKTNOSUPPORT;
+
+	if (!ns_capable(net->user_ns, CAP_NET_RAW))
+		return -EPERM;
+
+	if (!net_eq(net, &init_net))
+		return -EAFNOSUPPORT;
+
+	if (likely(sock->type == SOCK_DGRAM || sock->type == SOCK_STREAM)) {
+		rc = -ENOMEM;
+		sk = llc_sk_alloc(net, PF_LLC, GFP_KERNEL, &llc_proto, kern);
+		if (sk) {
+			rc = 0;
+			llc_ui_sk_init(sock, sk);
+		}
+	}
+	return rc;
+}
+
+/**
+ *	llc_ui_release - shutdown socket
+ *	@sock: Socket to release.
+ *
+ *	Shutdown and deallocate an existing socket.
+ */
+static int llc_ui_release(struct socket *sock)
+{
+	struct sock *sk = sock->sk;
+	struct llc_sock *llc;
+
+	if (unlikely(sk == NULL))
+		goto out;
+	sock_hold(sk);
+	lock_sock(sk);
+	llc = llc_sk(sk);
+	dprintk("%s: closing local(%02X) remote(%02X)\n", __func__,
+		llc->laddr.lsap, llc->daddr.lsap);
+	if (!llc_send_disc(sk))
+		llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo);
+	if (!sock_flag(sk, SOCK_ZAPPED)) {
+		struct llc_sap *sap = llc->sap;
+
+		/* Hold this for release_sock(), so that llc_backlog_rcv()
+		 * could still use it.
+		 */
+		llc_sap_hold(sap);
+		llc_sap_remove_socket(llc->sap, sk);
+		release_sock(sk);
+		llc_sap_put(sap);
+	} else {
+		release_sock(sk);
+	}
+	netdev_put(llc->dev, &llc->dev_tracker);
+	sock_put(sk);
+	llc_sk_free(sk);
+out:
+	return 0;
+}
+
+/**
+ *	llc_ui_autoport - provide dynamically allocate SAP number
+ *
+ *	Provide the caller with a dynamically allocated SAP number according
+ *	to the rules that are set in this function. Returns: 0, upon failure,
+ *	SAP number otherwise.
+ */
+static int llc_ui_autoport(void)
+{
+	struct llc_sap *sap;
+	int i, tries = 0;
+
+	while (tries < LLC_SAP_DYN_TRIES) {
+		for (i = llc_ui_sap_last_autoport;
+		     i < LLC_SAP_DYN_STOP; i += 2) {
+			sap = llc_sap_find(i);
+			if (!sap) {
+				llc_ui_sap_last_autoport = i + 2;
+				goto out;
+			}
+			llc_sap_put(sap);
+		}
+		llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
+		tries++;
+	}
+	i = 0;
+out:
+	return i;
+}
+
+/**
+ *	llc_ui_autobind - automatically bind a socket to a sap
+ *	@sock: socket to bind
+ *	@addr: address to connect to
+ *
+ * 	Used by llc_ui_connect and llc_ui_sendmsg when the user hasn't
+ * 	specifically used llc_ui_bind to bind to an specific address/sap
+ *
+ *	Returns: 0 upon success, negative otherwise.
+ */
+static int llc_ui_autobind(struct socket *sock, struct sockaddr_llc *addr)
+{
+	struct sock *sk = sock->sk;
+	struct llc_sock *llc = llc_sk(sk);
+	struct net_device *dev = NULL;
+	struct llc_sap *sap;
+	int rc = -EINVAL;
+
+	if (!sock_flag(sk, SOCK_ZAPPED))
+		goto out;
+	if (!addr->sllc_arphrd)
+		addr->sllc_arphrd = ARPHRD_ETHER;
+	if (addr->sllc_arphrd != ARPHRD_ETHER)
+		goto out;
+	rc = -ENODEV;
+	if (sk->sk_bound_dev_if) {
+		dev = dev_get_by_index(&init_net, sk->sk_bound_dev_if);
+		if (dev && addr->sllc_arphrd != dev->type) {
+			dev_put(dev);
+			dev = NULL;
+		}
+	} else
+		dev = dev_getfirstbyhwtype(&init_net, addr->sllc_arphrd);
+	if (!dev)
+		goto out;
+	rc = -EUSERS;
+	llc->laddr.lsap = llc_ui_autoport();
+	if (!llc->laddr.lsap)
+		goto out;
+	rc = -EBUSY; /* some other network layer is using the sap */
+	sap = llc_sap_open(llc->laddr.lsap, NULL);
+	if (!sap)
+		goto out;
+
+	/* Note: We do not expect errors from this point. */
+	llc->dev = dev;
+	netdev_tracker_alloc(llc->dev, &llc->dev_tracker, GFP_KERNEL);
+	dev = NULL;
+
+	memcpy(llc->laddr.mac, llc->dev->dev_addr, IFHWADDRLEN);
+	memcpy(&llc->addr, addr, sizeof(llc->addr));
+	/* assign new connection to its SAP */
+	llc_sap_add_socket(sap, sk);
+	sock_reset_flag(sk, SOCK_ZAPPED);
+	rc = 0;
+out:
+	dev_put(dev);
+	return rc;
+}
+
+/**
+ *	llc_ui_bind - bind a socket to a specific address.
+ *	@sock: Socket to bind an address to.
+ *	@uaddr: Address the user wants the socket bound to.
+ *	@addrlen: Length of the uaddr structure.
+ *
+ *	Bind a socket to a specific address. For llc a user is able to bind to
+ *	a specific sap only or mac + sap.
+ *	If the user desires to bind to a specific mac + sap, it is possible to
+ *	have multiple sap connections via multiple macs.
+ *	Bind and autobind for that matter must enforce the correct sap usage
+ *	otherwise all hell will break loose.
+ *	Returns: 0 upon success, negative otherwise.
+ */
+static int llc_ui_bind(struct socket *sock, struct sockaddr *uaddr, int addrlen)
+{
+	struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr;
+	struct sock *sk = sock->sk;
+	struct llc_sock *llc = llc_sk(sk);
+	struct net_device *dev = NULL;
+	struct llc_sap *sap;
+	int rc = -EINVAL;
+
+	lock_sock(sk);
+	if (unlikely(!sock_flag(sk, SOCK_ZAPPED) || addrlen != sizeof(*addr)))
+		goto out;
+	rc = -EAFNOSUPPORT;
+	if (!addr->sllc_arphrd)
+		addr->sllc_arphrd = ARPHRD_ETHER;
+	if (unlikely(addr->sllc_family != AF_LLC || addr->sllc_arphrd != ARPHRD_ETHER))
+		goto out;
+	dprintk("%s: binding %02X\n", __func__, addr->sllc_sap);
+	rc = -ENODEV;
+	rcu_read_lock();
+	if (sk->sk_bound_dev_if) {
+		dev = dev_get_by_index_rcu(&init_net, sk->sk_bound_dev_if);
+		if (dev) {
+			if (is_zero_ether_addr(addr->sllc_mac))
+				memcpy(addr->sllc_mac, dev->dev_addr,
+				       IFHWADDRLEN);
+			if (addr->sllc_arphrd != dev->type ||
+			    !ether_addr_equal(addr->sllc_mac,
+					      dev->dev_addr)) {
+				rc = -EINVAL;
+				dev = NULL;
+			}
+		}
+	} else {
+		dev = dev_getbyhwaddr_rcu(&init_net, addr->sllc_arphrd,
+					   addr->sllc_mac);
+	}
+	dev_hold(dev);
+	rcu_read_unlock();
+	if (!dev)
+		goto out;
+
+	if (!addr->sllc_sap) {
+		rc = -EUSERS;
+		addr->sllc_sap = llc_ui_autoport();
+		if (!addr->sllc_sap)
+			goto out;
+	}
+	sap = llc_sap_find(addr->sllc_sap);
+	if (!sap) {
+		sap = llc_sap_open(addr->sllc_sap, NULL);
+		rc = -EBUSY; /* some other network layer is using the sap */
+		if (!sap)
+			goto out;
+	} else {
+		struct llc_addr laddr, daddr;
+		struct sock *ask;
+
+		memset(&laddr, 0, sizeof(laddr));
+		memset(&daddr, 0, sizeof(daddr));
+		/*
+		 * FIXME: check if the address is multicast,
+		 * 	  only SOCK_DGRAM can do this.
+		 */
+		memcpy(laddr.mac, addr->sllc_mac, IFHWADDRLEN);
+		laddr.lsap = addr->sllc_sap;
+		rc = -EADDRINUSE; /* mac + sap clash. */
+		ask = llc_lookup_established(sap, &daddr, &laddr, &init_net);
+		if (ask) {
+			sock_put(ask);
+			goto out_put;
+		}
+	}
+
+	/* Note: We do not expect errors from this point. */
+	llc->dev = dev;
+	netdev_tracker_alloc(llc->dev, &llc->dev_tracker, GFP_KERNEL);
+	dev = NULL;
+
+	llc->laddr.lsap = addr->sllc_sap;
+	memcpy(llc->laddr.mac, addr->sllc_mac, IFHWADDRLEN);
+	memcpy(&llc->addr, addr, sizeof(llc->addr));
+	/* assign new connection to its SAP */
+	llc_sap_add_socket(sap, sk);
+	sock_reset_flag(sk, SOCK_ZAPPED);
+	rc = 0;
+out_put:
+	llc_sap_put(sap);
+out:
+	dev_put(dev);
+	release_sock(sk);
+	return rc;
+}
+
+/**
+ *	llc_ui_shutdown - shutdown a connect llc2 socket.
+ *	@sock: Socket to shutdown.
+ *	@how: What part of the socket to shutdown.
+ *
+ *	Shutdown a connected llc2 socket. Currently this function only supports
+ *	shutting down both sends and receives (2), we could probably make this
+ *	function such that a user can shutdown only half the connection but not
+ *	right now.
+ *	Returns: 0 upon success, negative otherwise.
+ */
+static int llc_ui_shutdown(struct socket *sock, int how)
+{
+	struct sock *sk = sock->sk;
+	int rc = -ENOTCONN;
+
+	lock_sock(sk);
+	if (unlikely(sk->sk_state != TCP_ESTABLISHED))
+		goto out;
+	rc = -EINVAL;
+	if (how != 2)
+		goto out;
+	rc = llc_send_disc(sk);
+	if (!rc)
+		rc = llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo);
+	/* Wake up anyone sleeping in poll */
+	sk->sk_state_change(sk);
+out:
+	release_sock(sk);
+	return rc;
+}
+
+/**
+ *	llc_ui_connect - Connect to a remote llc2 mac + sap.
+ *	@sock: Socket which will be connected to the remote destination.
+ *	@uaddr: Remote and possibly the local address of the new connection.
+ *	@addrlen: Size of uaddr structure.
+ *	@flags: Operational flags specified by the user.
+ *
+ *	Connect to a remote llc2 mac + sap. The caller must specify the
+ *	destination mac and address to connect to. If the user hasn't previously
+ *	called bind(2) with a smac the address of the first interface of the
+ *	specified arp type will be used.
+ *	This function will autobind if user did not previously call bind.
+ *	Returns: 0 upon success, negative otherwise.
+ */
+static int llc_ui_connect(struct socket *sock, struct sockaddr *uaddr,
+			  int addrlen, int flags)
+{
+	struct sock *sk = sock->sk;
+	struct llc_sock *llc = llc_sk(sk);
+	struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr;
+	int rc = -EINVAL;
+
+	lock_sock(sk);
+	if (unlikely(addrlen != sizeof(*addr)))
+		goto out;
+	rc = -EAFNOSUPPORT;
+	if (unlikely(addr->sllc_family != AF_LLC))
+		goto out;
+	if (unlikely(sk->sk_type != SOCK_STREAM))
+		goto out;
+	rc = -EALREADY;
+	if (unlikely(sock->state == SS_CONNECTING))
+		goto out;
+	/* bind connection to sap if user hasn't done it. */
+	if (sock_flag(sk, SOCK_ZAPPED)) {
+		/* bind to sap with null dev, exclusive */
+		rc = llc_ui_autobind(sock, addr);
+		if (rc)
+			goto out;
+	}
+	llc->daddr.lsap = addr->sllc_sap;
+	memcpy(llc->daddr.mac, addr->sllc_mac, IFHWADDRLEN);
+	sock->state = SS_CONNECTING;
+	sk->sk_state   = TCP_SYN_SENT;
+	llc->link   = llc_ui_next_link_no(llc->sap->laddr.lsap);
+	rc = llc_establish_connection(sk, llc->dev->dev_addr,
+				      addr->sllc_mac, addr->sllc_sap);
+	if (rc) {
+		dprintk("%s: llc_ui_send_conn failed :-(\n", __func__);
+		sock->state  = SS_UNCONNECTED;
+		sk->sk_state = TCP_CLOSE;
+		goto out;
+	}
+
+	if (sk->sk_state == TCP_SYN_SENT) {
+		const long timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
+
+		if (!timeo || !llc_ui_wait_for_conn(sk, timeo))
+			goto out;
+
+		rc = sock_intr_errno(timeo);
+		if (signal_pending(current))
+			goto out;
+	}
+
+	if (sk->sk_state == TCP_CLOSE)
+		goto sock_error;
+
+	sock->state = SS_CONNECTED;
+	rc = 0;
+out:
+	release_sock(sk);
+	return rc;
+sock_error:
+	rc = sock_error(sk) ? : -ECONNABORTED;
+	sock->state = SS_UNCONNECTED;
+	goto out;
+}
+
+/**
+ *	llc_ui_listen - allow a normal socket to accept incoming connections
+ *	@sock: Socket to allow incoming connections on.
+ *	@backlog: Number of connections to queue.
+ *
+ *	Allow a normal socket to accept incoming connections.
+ *	Returns 0 upon success, negative otherwise.
+ */
+static int llc_ui_listen(struct socket *sock, int backlog)
+{
+	struct sock *sk = sock->sk;
+	int rc = -EINVAL;
+
+	lock_sock(sk);
+	if (unlikely(sock->state != SS_UNCONNECTED))
+		goto out;
+	rc = -EOPNOTSUPP;
+	if (unlikely(sk->sk_type != SOCK_STREAM))
+		goto out;
+	rc = -EAGAIN;
+	if (sock_flag(sk, SOCK_ZAPPED))
+		goto out;
+	rc = 0;
+	if (!(unsigned int)backlog)	/* BSDism */
+		backlog = 1;
+	sk->sk_max_ack_backlog = backlog;
+	if (sk->sk_state != TCP_LISTEN) {
+		sk->sk_ack_backlog = 0;
+		sk->sk_state	   = TCP_LISTEN;
+	}
+	sk->sk_socket->flags |= __SO_ACCEPTCON;
+out:
+	release_sock(sk);
+	return rc;
+}
+
+static int llc_ui_wait_for_disc(struct sock *sk, long timeout)
+{
+	DEFINE_WAIT_FUNC(wait, woken_wake_function);
+	int rc = 0;
+
+	add_wait_queue(sk_sleep(sk), &wait);
+	while (1) {
+		if (sk_wait_event(sk, &timeout,
+				  READ_ONCE(sk->sk_state) == TCP_CLOSE, &wait))
+			break;
+		rc = -ERESTARTSYS;
+		if (signal_pending(current))
+			break;
+		rc = -EAGAIN;
+		if (!timeout)
+			break;
+		rc = 0;
+	}
+	remove_wait_queue(sk_sleep(sk), &wait);
+	return rc;
+}
+
+static bool llc_ui_wait_for_conn(struct sock *sk, long timeout)
+{
+	DEFINE_WAIT_FUNC(wait, woken_wake_function);
+
+	add_wait_queue(sk_sleep(sk), &wait);
+	while (1) {
+		if (sk_wait_event(sk, &timeout,
+				  READ_ONCE(sk->sk_state) != TCP_SYN_SENT, &wait))
+			break;
+		if (signal_pending(current) || !timeout)
+			break;
+	}
+	remove_wait_queue(sk_sleep(sk), &wait);
+	return timeout;
+}
+
+static int llc_ui_wait_for_busy_core(struct sock *sk, long timeout)
+{
+	DEFINE_WAIT_FUNC(wait, woken_wake_function);
+	struct llc_sock *llc = llc_sk(sk);
+	int rc;
+
+	add_wait_queue(sk_sleep(sk), &wait);
+	while (1) {
+		rc = 0;
+		if (sk_wait_event(sk, &timeout,
+				  (READ_ONCE(sk->sk_shutdown) & RCV_SHUTDOWN) ||
+				  (!llc_data_accept_state(llc->state) &&
+				   !llc->remote_busy_flag &&
+				   !llc->p_flag), &wait))
+			break;
+		rc = -ERESTARTSYS;
+		if (signal_pending(current))
+			break;
+		rc = -EAGAIN;
+		if (!timeout)
+			break;
+	}
+	remove_wait_queue(sk_sleep(sk), &wait);
+	return rc;
+}
+
+static int llc_wait_data(struct sock *sk, long timeo)
+{
+	int rc;
+
+	while (1) {
+		/*
+		 * POSIX 1003.1g mandates this order.
+		 */
+		rc = sock_error(sk);
+		if (rc)
+			break;
+		rc = 0;
+		if (sk->sk_shutdown & RCV_SHUTDOWN)
+			break;
+		rc = -EAGAIN;
+		if (!timeo)
+			break;
+		rc = sock_intr_errno(timeo);
+		if (signal_pending(current))
+			break;
+		rc = 0;
+		if (sk_wait_data(sk, &timeo, NULL))
+			break;
+	}
+	return rc;
+}
+
+static void llc_cmsg_rcv(struct msghdr *msg, struct sk_buff *skb)
+{
+	struct llc_sock *llc = llc_sk(skb->sk);
+
+	if (llc->cmsg_flags & LLC_CMSG_PKTINFO) {
+		struct llc_pktinfo info;
+
+		memset(&info, 0, sizeof(info));
+		info.lpi_ifindex = llc_sk(skb->sk)->dev->ifindex;
+		llc_pdu_decode_dsap(skb, &info.lpi_sap);
+		llc_pdu_decode_da(skb, info.lpi_mac);
+		put_cmsg(msg, SOL_LLC, LLC_OPT_PKTINFO, sizeof(info), &info);
+	}
+}
+
+/**
+ *	llc_ui_accept - accept a new incoming connection.
+ *	@sock: Socket which connections arrive on.
+ *	@newsock: Socket to move incoming connection to.
+ *	@flags: User specified operational flags.
+ *	@kern: If the socket is kernel internal
+ *
+ *	Accept a new incoming connection.
+ *	Returns 0 upon success, negative otherwise.
+ */
+static int llc_ui_accept(struct socket *sock, struct socket *newsock, int flags,
+			 bool kern)
+{
+	struct sock *sk = sock->sk, *newsk;
+	struct llc_sock *llc, *newllc;
+	struct sk_buff *skb;
+	int rc = -EOPNOTSUPP;
+
+	dprintk("%s: accepting on %02X\n", __func__,
+		llc_sk(sk)->laddr.lsap);
+	lock_sock(sk);
+	if (unlikely(sk->sk_type != SOCK_STREAM))
+		goto out;
+	rc = -EINVAL;
+	if (unlikely(sock->state != SS_UNCONNECTED ||
+		     sk->sk_state != TCP_LISTEN))
+		goto out;
+	/* wait for a connection to arrive. */
+	if (skb_queue_empty(&sk->sk_receive_queue)) {
+		rc = llc_wait_data(sk, sk->sk_rcvtimeo);
+		if (rc)
+			goto out;
+	}
+	dprintk("%s: got a new connection on %02X\n", __func__,
+		llc_sk(sk)->laddr.lsap);
+	skb = skb_dequeue(&sk->sk_receive_queue);
+	rc = -EINVAL;
+	if (!skb->sk)
+		goto frees;
+	rc = 0;
+	newsk = skb->sk;
+	/* attach connection to a new socket. */
+	llc_ui_sk_init(newsock, newsk);
+	sock_reset_flag(newsk, SOCK_ZAPPED);
+	newsk->sk_state		= TCP_ESTABLISHED;
+	newsock->state		= SS_CONNECTED;
+	llc			= llc_sk(sk);
+	newllc			= llc_sk(newsk);
+	memcpy(&newllc->addr, &llc->addr, sizeof(newllc->addr));
+	newllc->link = llc_ui_next_link_no(newllc->laddr.lsap);
+
+	/* put original socket back into a clean listen state. */
+	sk->sk_state = TCP_LISTEN;
+	sk_acceptq_removed(sk);
+	dprintk("%s: ok success on %02X, client on %02X\n", __func__,
+		llc_sk(sk)->addr.sllc_sap, newllc->daddr.lsap);
+frees:
+	kfree_skb(skb);
+out:
+	release_sock(sk);
+	return rc;
+}
+
+/**
+ *	llc_ui_recvmsg - copy received data to the socket user.
+ *	@sock: Socket to copy data from.
+ *	@msg: Various user space related information.
+ *	@len: Size of user buffer.
+ *	@flags: User specified flags.
+ *
+ *	Copy received data to the socket user.
+ *	Returns non-negative upon success, negative otherwise.
+ */
+static int llc_ui_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
+			  int flags)
+{
+	DECLARE_SOCKADDR(struct sockaddr_llc *, uaddr, msg->msg_name);
+	const int nonblock = flags & MSG_DONTWAIT;
+	struct sk_buff *skb = NULL;
+	struct sock *sk = sock->sk;
+	struct llc_sock *llc = llc_sk(sk);
+	size_t copied = 0;
+	u32 peek_seq = 0;
+	u32 *seq, skb_len;
+	unsigned long used;
+	int target;	/* Read at least this many bytes */
+	long timeo;
+
+	lock_sock(sk);
+	copied = -ENOTCONN;
+	if (unlikely(sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_LISTEN))
+		goto out;
+
+	timeo = sock_rcvtimeo(sk, nonblock);
+
+	seq = &llc->copied_seq;
+	if (flags & MSG_PEEK) {
+		peek_seq = llc->copied_seq;
+		seq = &peek_seq;
+	}
+
+	target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
+	copied = 0;
+
+	do {
+		u32 offset;
+
+		/*
+		 * We need to check signals first, to get correct SIGURG
+		 * handling. FIXME: Need to check this doesn't impact 1003.1g
+		 * and move it down to the bottom of the loop
+		 */
+		if (signal_pending(current)) {
+			if (copied)
+				break;
+			copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
+			break;
+		}
+
+		/* Next get a buffer. */
+
+		skb = skb_peek(&sk->sk_receive_queue);
+		if (skb) {
+			offset = *seq;
+			goto found_ok_skb;
+		}
+		/* Well, if we have backlog, try to process it now yet. */
+
+		if (copied >= target && !READ_ONCE(sk->sk_backlog.tail))
+			break;
+
+		if (copied) {
+			if (sk->sk_err ||
+			    sk->sk_state == TCP_CLOSE ||
+			    (sk->sk_shutdown & RCV_SHUTDOWN) ||
+			    !timeo ||
+			    (flags & MSG_PEEK))
+				break;
+		} else {
+			if (sock_flag(sk, SOCK_DONE))
+				break;
+
+			if (sk->sk_err) {
+				copied = sock_error(sk);
+				break;
+			}
+			if (sk->sk_shutdown & RCV_SHUTDOWN)
+				break;
+
+			if (sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_CLOSE) {
+				if (!sock_flag(sk, SOCK_DONE)) {
+					/*
+					 * This occurs when user tries to read
+					 * from never connected socket.
+					 */
+					copied = -ENOTCONN;
+					break;
+				}
+				break;
+			}
+			if (!timeo) {
+				copied = -EAGAIN;
+				break;
+			}
+		}
+
+		if (copied >= target) { /* Do not sleep, just process backlog. */
+			release_sock(sk);
+			lock_sock(sk);
+		} else
+			sk_wait_data(sk, &timeo, NULL);
+
+		if ((flags & MSG_PEEK) && peek_seq != llc->copied_seq) {
+			net_dbg_ratelimited("LLC(%s:%d): Application bug, race in MSG_PEEK\n",
+					    current->comm,
+					    task_pid_nr(current));
+			peek_seq = llc->copied_seq;
+		}
+		continue;
+	found_ok_skb:
+		skb_len = skb->len;
+		/* Ok so how much can we use? */
+		used = skb->len - offset;
+		if (len < used)
+			used = len;
+
+		if (!(flags & MSG_TRUNC)) {
+			int rc = skb_copy_datagram_msg(skb, offset, msg, used);
+			if (rc) {
+				/* Exception. Bailout! */
+				if (!copied)
+					copied = -EFAULT;
+				break;
+			}
+		}
+
+		*seq += used;
+		copied += used;
+		len -= used;
+
+		/* For non stream protcols we get one packet per recvmsg call */
+		if (sk->sk_type != SOCK_STREAM)
+			goto copy_uaddr;
+
+		if (!(flags & MSG_PEEK)) {
+			skb_unlink(skb, &sk->sk_receive_queue);
+			kfree_skb(skb);
+			*seq = 0;
+		}
+
+		/* Partial read */
+		if (used + offset < skb_len)
+			continue;
+	} while (len > 0);
+
+out:
+	release_sock(sk);
+	return copied;
+copy_uaddr:
+	if (uaddr != NULL && skb != NULL) {
+		memcpy(uaddr, llc_ui_skb_cb(skb), sizeof(*uaddr));
+		msg->msg_namelen = sizeof(*uaddr);
+	}
+	if (llc_sk(sk)->cmsg_flags)
+		llc_cmsg_rcv(msg, skb);
+
+	if (!(flags & MSG_PEEK)) {
+		skb_unlink(skb, &sk->sk_receive_queue);
+		kfree_skb(skb);
+		*seq = 0;
+	}
+
+	goto out;
+}
+
+/**
+ *	llc_ui_sendmsg - Transmit data provided by the socket user.
+ *	@sock: Socket to transmit data from.
+ *	@msg: Various user related information.
+ *	@len: Length of data to transmit.
+ *
+ *	Transmit data provided by the socket user.
+ *	Returns non-negative upon success, negative otherwise.
+ */
+static int llc_ui_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
+{
+	DECLARE_SOCKADDR(struct sockaddr_llc *, addr, msg->msg_name);
+	struct sock *sk = sock->sk;
+	struct llc_sock *llc = llc_sk(sk);
+	int flags = msg->msg_flags;
+	int noblock = flags & MSG_DONTWAIT;
+	int rc = -EINVAL, copied = 0, hdrlen, hh_len;
+	struct sk_buff *skb = NULL;
+	struct net_device *dev;
+	size_t size = 0;
+
+	dprintk("%s: sending from %02X to %02X\n", __func__,
+		llc->laddr.lsap, llc->daddr.lsap);
+	lock_sock(sk);
+	if (addr) {
+		if (msg->msg_namelen < sizeof(*addr))
+			goto out;
+	} else {
+		if (llc_ui_addr_null(&llc->addr))
+			goto out;
+		addr = &llc->addr;
+	}
+	/* must bind connection to sap if user hasn't done it. */
+	if (sock_flag(sk, SOCK_ZAPPED)) {
+		/* bind to sap with null dev, exclusive. */
+		rc = llc_ui_autobind(sock, addr);
+		if (rc)
+			goto out;
+	}
+	dev = llc->dev;
+	hh_len = LL_RESERVED_SPACE(dev);
+	hdrlen = llc_ui_header_len(sk, addr);
+	size = hdrlen + len;
+	size = min_t(size_t, size, READ_ONCE(dev->mtu));
+	copied = size - hdrlen;
+	rc = -EINVAL;
+	if (copied < 0)
+		goto out;
+	release_sock(sk);
+	skb = sock_alloc_send_skb(sk, hh_len + size, noblock, &rc);
+	lock_sock(sk);
+	if (!skb)
+		goto out;
+	if (sock_flag(sk, SOCK_ZAPPED) ||
+	    llc->dev != dev ||
+	    hdrlen != llc_ui_header_len(sk, addr) ||
+	    hh_len != LL_RESERVED_SPACE(dev) ||
+	    size > READ_ONCE(dev->mtu))
+		goto out;
+	skb->dev      = dev;
+	skb->protocol = llc_proto_type(addr->sllc_arphrd);
+	skb_reserve(skb, hh_len + hdrlen);
+	rc = memcpy_from_msg(skb_put(skb, copied), msg, copied);
+	if (rc)
+		goto out;
+	if (sk->sk_type == SOCK_DGRAM || addr->sllc_ua) {
+		llc_build_and_send_ui_pkt(llc->sap, skb, addr->sllc_mac,
+					  addr->sllc_sap);
+		skb = NULL;
+		goto out;
+	}
+	if (addr->sllc_test) {
+		llc_build_and_send_test_pkt(llc->sap, skb, addr->sllc_mac,
+					    addr->sllc_sap);
+		skb = NULL;
+		goto out;
+	}
+	if (addr->sllc_xid) {
+		llc_build_and_send_xid_pkt(llc->sap, skb, addr->sllc_mac,
+					   addr->sllc_sap);
+		skb = NULL;
+		goto out;
+	}
+	rc = -ENOPROTOOPT;
+	if (!(sk->sk_type == SOCK_STREAM && !addr->sllc_ua))
+		goto out;
+	rc = llc_ui_send_data(sk, skb, noblock);
+	skb = NULL;
+out:
+	kfree_skb(skb);
+	if (rc)
+		dprintk("%s: failed sending from %02X to %02X: %d\n",
+			__func__, llc->laddr.lsap, llc->daddr.lsap, rc);
+	release_sock(sk);
+	return rc ? : copied;
+}
+
+/**
+ *	llc_ui_getname - return the address info of a socket
+ *	@sock: Socket to get address of.
+ *	@uaddr: Address structure to return information.
+ *	@peer: Does user want local or remote address information.
+ *
+ *	Return the address information of a socket.
+ */
+static int llc_ui_getname(struct socket *sock, struct sockaddr *uaddr,
+			  int peer)
+{
+	struct sockaddr_llc sllc;
+	struct sock *sk = sock->sk;
+	struct llc_sock *llc = llc_sk(sk);
+	int rc = -EBADF;
+
+	memset(&sllc, 0, sizeof(sllc));
+	lock_sock(sk);
+	if (sock_flag(sk, SOCK_ZAPPED))
+		goto out;
+	if (peer) {
+		rc = -ENOTCONN;
+		if (sk->sk_state != TCP_ESTABLISHED)
+			goto out;
+		if(llc->dev)
+			sllc.sllc_arphrd = llc->dev->type;
+		sllc.sllc_sap = llc->daddr.lsap;
+		memcpy(&sllc.sllc_mac, &llc->daddr.mac, IFHWADDRLEN);
+	} else {
+		rc = -EINVAL;
+		if (!llc->sap)
+			goto out;
+		sllc.sllc_sap = llc->sap->laddr.lsap;
+
+		if (llc->dev) {
+			sllc.sllc_arphrd = llc->dev->type;
+			memcpy(&sllc.sllc_mac, llc->dev->dev_addr,
+			       IFHWADDRLEN);
+		}
+	}
+	sllc.sllc_family = AF_LLC;
+	memcpy(uaddr, &sllc, sizeof(sllc));
+	rc = sizeof(sllc);
+out:
+	release_sock(sk);
+	return rc;
+}
+
+/**
+ *	llc_ui_ioctl - io controls for PF_LLC
+ *	@sock: Socket to get/set info
+ *	@cmd: command
+ *	@arg: optional argument for cmd
+ *
+ *	get/set info on llc sockets
+ */
+static int llc_ui_ioctl(struct socket *sock, unsigned int cmd,
+			unsigned long arg)
+{
+	return -ENOIOCTLCMD;
+}
+
+/**
+ *	llc_ui_setsockopt - set various connection specific parameters.
+ *	@sock: Socket to set options on.
+ *	@level: Socket level user is requesting operations on.
+ *	@optname: Operation name.
+ *	@optval: User provided operation data.
+ *	@optlen: Length of optval.
+ *
+ *	Set various connection specific parameters.
+ */
+static int llc_ui_setsockopt(struct socket *sock, int level, int optname,
+			     sockptr_t optval, unsigned int optlen)
+{
+	struct sock *sk = sock->sk;
+	struct llc_sock *llc = llc_sk(sk);
+	unsigned int opt;
+	int rc = -EINVAL;
+
+	lock_sock(sk);
+	if (unlikely(level != SOL_LLC || optlen != sizeof(int)))
+		goto out;
+	rc = copy_from_sockptr(&opt, optval, sizeof(opt));
+	if (rc)
+		goto out;
+	rc = -EINVAL;
+	switch (optname) {
+	case LLC_OPT_RETRY:
+		if (opt > LLC_OPT_MAX_RETRY)
+			goto out;
+		llc->n2 = opt;
+		break;
+	case LLC_OPT_SIZE:
+		if (opt > LLC_OPT_MAX_SIZE)
+			goto out;
+		llc->n1 = opt;
+		break;
+	case LLC_OPT_ACK_TMR_EXP:
+		if (opt > LLC_OPT_MAX_ACK_TMR_EXP)
+			goto out;
+		llc->ack_timer.expire = opt * HZ;
+		break;
+	case LLC_OPT_P_TMR_EXP:
+		if (opt > LLC_OPT_MAX_P_TMR_EXP)
+			goto out;
+		llc->pf_cycle_timer.expire = opt * HZ;
+		break;
+	case LLC_OPT_REJ_TMR_EXP:
+		if (opt > LLC_OPT_MAX_REJ_TMR_EXP)
+			goto out;
+		llc->rej_sent_timer.expire = opt * HZ;
+		break;
+	case LLC_OPT_BUSY_TMR_EXP:
+		if (opt > LLC_OPT_MAX_BUSY_TMR_EXP)
+			goto out;
+		llc->busy_state_timer.expire = opt * HZ;
+		break;
+	case LLC_OPT_TX_WIN:
+		if (opt > LLC_OPT_MAX_WIN)
+			goto out;
+		llc->k = opt;
+		break;
+	case LLC_OPT_RX_WIN:
+		if (opt > LLC_OPT_MAX_WIN)
+			goto out;
+		llc->rw = opt;
+		break;
+	case LLC_OPT_PKTINFO:
+		if (opt)
+			llc->cmsg_flags |= LLC_CMSG_PKTINFO;
+		else
+			llc->cmsg_flags &= ~LLC_CMSG_PKTINFO;
+		break;
+	default:
+		rc = -ENOPROTOOPT;
+		goto out;
+	}
+	rc = 0;
+out:
+	release_sock(sk);
+	return rc;
+}
+
+/**
+ *	llc_ui_getsockopt - get connection specific socket info
+ *	@sock: Socket to get information from.
+ *	@level: Socket level user is requesting operations on.
+ *	@optname: Operation name.
+ *	@optval: Variable to return operation data in.
+ *	@optlen: Length of optval.
+ *
+ *	Get connection specific socket information.
+ */
+static int llc_ui_getsockopt(struct socket *sock, int level, int optname,
+			     char __user *optval, int __user *optlen)
+{
+	struct sock *sk = sock->sk;
+	struct llc_sock *llc = llc_sk(sk);
+	int val = 0, len = 0, rc = -EINVAL;
+
+	lock_sock(sk);
+	if (unlikely(level != SOL_LLC))
+		goto out;
+	rc = get_user(len, optlen);
+	if (rc)
+		goto out;
+	rc = -EINVAL;
+	if (len != sizeof(int))
+		goto out;
+	switch (optname) {
+	case LLC_OPT_RETRY:
+		val = llc->n2;					break;
+	case LLC_OPT_SIZE:
+		val = llc->n1;					break;
+	case LLC_OPT_ACK_TMR_EXP:
+		val = llc->ack_timer.expire / HZ;		break;
+	case LLC_OPT_P_TMR_EXP:
+		val = llc->pf_cycle_timer.expire / HZ;		break;
+	case LLC_OPT_REJ_TMR_EXP:
+		val = llc->rej_sent_timer.expire / HZ;		break;
+	case LLC_OPT_BUSY_TMR_EXP:
+		val = llc->busy_state_timer.expire / HZ;	break;
+	case LLC_OPT_TX_WIN:
+		val = llc->k;				break;
+	case LLC_OPT_RX_WIN:
+		val = llc->rw;				break;
+	case LLC_OPT_PKTINFO:
+		val = (llc->cmsg_flags & LLC_CMSG_PKTINFO) != 0;
+		break;
+	default:
+		rc = -ENOPROTOOPT;
+		goto out;
+	}
+	rc = 0;
+	if (put_user(len, optlen) || copy_to_user(optval, &val, len))
+		rc = -EFAULT;
+out:
+	release_sock(sk);
+	return rc;
+}
+
+static const struct net_proto_family llc_ui_family_ops = {
+	.family = PF_LLC,
+	.create = llc_ui_create,
+	.owner	= THIS_MODULE,
+};
+
+static const struct proto_ops llc_ui_ops = {
+	.family	     = PF_LLC,
+	.owner       = THIS_MODULE,
+	.release     = llc_ui_release,
+	.bind	     = llc_ui_bind,
+	.connect     = llc_ui_connect,
+	.socketpair  = sock_no_socketpair,
+	.accept      = llc_ui_accept,
+	.getname     = llc_ui_getname,
+	.poll	     = datagram_poll,
+	.ioctl       = llc_ui_ioctl,
+	.listen      = llc_ui_listen,
+	.shutdown    = llc_ui_shutdown,
+	.setsockopt  = llc_ui_setsockopt,
+	.getsockopt  = llc_ui_getsockopt,
+	.sendmsg     = llc_ui_sendmsg,
+	.recvmsg     = llc_ui_recvmsg,
+	.mmap	     = sock_no_mmap,
+};
+
+static const char llc_proc_err_msg[] __initconst =
+	KERN_CRIT "LLC: Unable to register the proc_fs entries\n";
+static const char llc_sysctl_err_msg[] __initconst =
+	KERN_CRIT "LLC: Unable to register the sysctl entries\n";
+static const char llc_sock_err_msg[] __initconst =
+	KERN_CRIT "LLC: Unable to register the network family\n";
+
+static int __init llc2_init(void)
+{
+	int rc = proto_register(&llc_proto, 0);
+
+	if (rc != 0)
+		goto out;
+
+	llc_build_offset_table();
+	llc_station_init();
+	llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
+	rc = llc_proc_init();
+	if (rc != 0) {
+		printk(llc_proc_err_msg);
+		goto out_station;
+	}
+	rc = llc_sysctl_init();
+	if (rc) {
+		printk(llc_sysctl_err_msg);
+		goto out_proc;
+	}
+	rc = sock_register(&llc_ui_family_ops);
+	if (rc) {
+		printk(llc_sock_err_msg);
+		goto out_sysctl;
+	}
+	llc_add_pack(LLC_DEST_SAP, llc_sap_handler);
+	llc_add_pack(LLC_DEST_CONN, llc_conn_handler);
+out:
+	return rc;
+out_sysctl:
+	llc_sysctl_exit();
+out_proc:
+	llc_proc_exit();
+out_station:
+	llc_station_exit();
+	proto_unregister(&llc_proto);
+	goto out;
+}
+
+static void __exit llc2_exit(void)
+{
+	llc_station_exit();
+	llc_remove_pack(LLC_DEST_SAP);
+	llc_remove_pack(LLC_DEST_CONN);
+	sock_unregister(PF_LLC);
+	llc_proc_exit();
+	llc_sysctl_exit();
+	proto_unregister(&llc_proto);
+}
+
+module_init(llc2_init);
+module_exit(llc2_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Procom 1997, Jay Schullist 2001, Arnaldo C. Melo 2001-2003");
+MODULE_DESCRIPTION("IEEE 802.2 PF_LLC support");
+MODULE_ALIAS_NETPROTO(PF_LLC);