Adding upstream version 6.1.76.upstream/6.1.76upstream

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

19 files changed, 5766 insertions, 0 deletions

diff --git a/net/caif/Kconfig b/net/caif/Kconfig
new file mode 100644
index 000000000..87205251c
--- /dev/null
+++ b/net/caif/Kconfig
@@ -0,0 +1,54 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# CAIF net configurations
+#
+
+menuconfig CAIF
+	tristate "CAIF support"
+	select CRC_CCITT
+	default n
+	help
+	The "Communication CPU to Application CPU Interface" (CAIF) is a packet
+	based connection-oriented MUX protocol developed by ST-Ericsson for use
+	with its modems. It is accessed from user space as sockets (PF_CAIF).
+
+	Say Y (or M) here if you build for a phone product (e.g. Android or
+	MeeGo) that uses CAIF as transport. If unsure say N.
+
+	If you select to build it as module then CAIF_NETDEV also needs to be
+	built as a module. You will also need to say Y (or M) to any CAIF
+	physical devices that your platform requires.
+
+	See Documentation/networking/caif for a further explanation on how to
+	use and configure CAIF.
+
+config  CAIF_DEBUG
+	bool "Enable Debug"
+	depends on CAIF
+	default n
+	help
+	Enable the inclusion of debug code in the CAIF stack.
+	Be aware that doing this will impact performance.
+	If unsure say N.
+
+config CAIF_NETDEV
+	tristate "CAIF GPRS Network device"
+	depends on CAIF
+	default CAIF
+	help
+	Say Y if you will be using a CAIF based GPRS network device.
+	This can be either built-in or a loadable module.
+	If you select to build it as a built-in then the main CAIF device must
+	also be a built-in.
+	If unsure say Y.
+
+config CAIF_USB
+	tristate "CAIF USB support"
+	depends on CAIF
+	default n
+	help
+	Say Y if you are using CAIF over USB CDC NCM.
+	This can be either built-in or a loadable module.
+	If you select to build it as a built-in then the main CAIF device must
+	also be a built-in.
+	If unsure say N.
diff --git a/net/caif/Makefile b/net/caif/Makefile
new file mode 100644
index 000000000..4f6c0517c
--- /dev/null
+++ b/net/caif/Makefile
@@ -0,0 +1,16 @@
+# SPDX-License-Identifier: GPL-2.0
+ccflags-$(CONFIG_CAIF_DEBUG)     :=      -DDEBUG
+
+caif-y := caif_dev.o \
+	cfcnfg.o cfmuxl.o cfctrl.o  \
+	cffrml.o cfveil.o cfdbgl.o\
+	cfserl.o cfdgml.o  \
+	cfrfml.o cfvidl.o cfutill.o \
+	cfsrvl.o cfpkt_skbuff.o
+
+obj-$(CONFIG_CAIF) += caif.o
+obj-$(CONFIG_CAIF_NETDEV) += chnl_net.o
+obj-$(CONFIG_CAIF) += caif_socket.o
+obj-$(CONFIG_CAIF_USB) += caif_usb.o
+
+export-y := caif.o
diff --git a/net/caif/caif_dev.c b/net/caif/caif_dev.c
new file mode 100644
index 000000000..6a0cba4fc
--- /dev/null
+++ b/net/caif/caif_dev.c
@@ -0,0 +1,585 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * CAIF Interface registration.
+ * Copyright (C) ST-Ericsson AB 2010
+ * Author:	Sjur Brendeland
+ *
+ * Borrowed heavily from file: pn_dev.c. Thanks to Remi Denis-Courmont
+ *  and Sakari Ailus <sakari.ailus@nokia.com>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
+
+#include <linux/kernel.h>
+#include <linux/if_arp.h>
+#include <linux/net.h>
+#include <linux/netdevice.h>
+#include <linux/mutex.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <net/netns/generic.h>
+#include <net/net_namespace.h>
+#include <net/pkt_sched.h>
+#include <net/caif/caif_device.h>
+#include <net/caif/caif_layer.h>
+#include <net/caif/caif_dev.h>
+#include <net/caif/cfpkt.h>
+#include <net/caif/cfcnfg.h>
+#include <net/caif/cfserl.h>
+
+MODULE_LICENSE("GPL");
+
+/* Used for local tracking of the CAIF net devices */
+struct caif_device_entry {
+	struct cflayer layer;
+	struct list_head list;
+	struct net_device *netdev;
+	int __percpu *pcpu_refcnt;
+	spinlock_t flow_lock;
+	struct sk_buff *xoff_skb;
+	void (*xoff_skb_dtor)(struct sk_buff *skb);
+	bool xoff;
+};
+
+struct caif_device_entry_list {
+	struct list_head list;
+	/* Protects simulanous deletes in list */
+	struct mutex lock;
+};
+
+struct caif_net {
+	struct cfcnfg *cfg;
+	struct caif_device_entry_list caifdevs;
+};
+
+static unsigned int caif_net_id;
+static int q_high = 50; /* Percent */
+
+struct cfcnfg *get_cfcnfg(struct net *net)
+{
+	struct caif_net *caifn;
+	caifn = net_generic(net, caif_net_id);
+	return caifn->cfg;
+}
+EXPORT_SYMBOL(get_cfcnfg);
+
+static struct caif_device_entry_list *caif_device_list(struct net *net)
+{
+	struct caif_net *caifn;
+	caifn = net_generic(net, caif_net_id);
+	return &caifn->caifdevs;
+}
+
+static void caifd_put(struct caif_device_entry *e)
+{
+	this_cpu_dec(*e->pcpu_refcnt);
+}
+
+static void caifd_hold(struct caif_device_entry *e)
+{
+	this_cpu_inc(*e->pcpu_refcnt);
+}
+
+static int caifd_refcnt_read(struct caif_device_entry *e)
+{
+	int i, refcnt = 0;
+	for_each_possible_cpu(i)
+		refcnt += *per_cpu_ptr(e->pcpu_refcnt, i);
+	return refcnt;
+}
+
+/* Allocate new CAIF device. */
+static struct caif_device_entry *caif_device_alloc(struct net_device *dev)
+{
+	struct caif_device_entry *caifd;
+
+	caifd = kzalloc(sizeof(*caifd), GFP_KERNEL);
+	if (!caifd)
+		return NULL;
+	caifd->pcpu_refcnt = alloc_percpu(int);
+	if (!caifd->pcpu_refcnt) {
+		kfree(caifd);
+		return NULL;
+	}
+	caifd->netdev = dev;
+	dev_hold(dev);
+	return caifd;
+}
+
+static struct caif_device_entry *caif_get(struct net_device *dev)
+{
+	struct caif_device_entry_list *caifdevs =
+	    caif_device_list(dev_net(dev));
+	struct caif_device_entry *caifd;
+
+	list_for_each_entry_rcu(caifd, &caifdevs->list, list,
+				lockdep_rtnl_is_held()) {
+		if (caifd->netdev == dev)
+			return caifd;
+	}
+	return NULL;
+}
+
+static void caif_flow_cb(struct sk_buff *skb)
+{
+	struct caif_device_entry *caifd;
+	void (*dtor)(struct sk_buff *skb) = NULL;
+	bool send_xoff;
+
+	WARN_ON(skb->dev == NULL);
+
+	rcu_read_lock();
+	caifd = caif_get(skb->dev);
+
+	WARN_ON(caifd == NULL);
+	if (!caifd) {
+		rcu_read_unlock();
+		return;
+	}
+
+	caifd_hold(caifd);
+	rcu_read_unlock();
+
+	spin_lock_bh(&caifd->flow_lock);
+	send_xoff = caifd->xoff;
+	caifd->xoff = false;
+	dtor = caifd->xoff_skb_dtor;
+
+	if (WARN_ON(caifd->xoff_skb != skb))
+		skb = NULL;
+
+	caifd->xoff_skb = NULL;
+	caifd->xoff_skb_dtor = NULL;
+
+	spin_unlock_bh(&caifd->flow_lock);
+
+	if (dtor && skb)
+		dtor(skb);
+
+	if (send_xoff)
+		caifd->layer.up->
+			ctrlcmd(caifd->layer.up,
+				_CAIF_CTRLCMD_PHYIF_FLOW_ON_IND,
+				caifd->layer.id);
+	caifd_put(caifd);
+}
+
+static int transmit(struct cflayer *layer, struct cfpkt *pkt)
+{
+	int err, high = 0, qlen = 0;
+	struct caif_device_entry *caifd =
+	    container_of(layer, struct caif_device_entry, layer);
+	struct sk_buff *skb;
+	struct netdev_queue *txq;
+
+	rcu_read_lock_bh();
+
+	skb = cfpkt_tonative(pkt);
+	skb->dev = caifd->netdev;
+	skb_reset_network_header(skb);
+	skb->protocol = htons(ETH_P_CAIF);
+
+	/* Check if we need to handle xoff */
+	if (likely(caifd->netdev->priv_flags & IFF_NO_QUEUE))
+		goto noxoff;
+
+	if (unlikely(caifd->xoff))
+		goto noxoff;
+
+	if (likely(!netif_queue_stopped(caifd->netdev))) {
+		struct Qdisc *sch;
+
+		/* If we run with a TX queue, check if the queue is too long*/
+		txq = netdev_get_tx_queue(skb->dev, 0);
+		sch = rcu_dereference_bh(txq->qdisc);
+		if (likely(qdisc_is_empty(sch)))
+			goto noxoff;
+
+		/* can check for explicit qdisc len value only !NOLOCK,
+		 * always set flow off otherwise
+		 */
+		high = (caifd->netdev->tx_queue_len * q_high) / 100;
+		if (!(sch->flags & TCQ_F_NOLOCK) && likely(sch->q.qlen < high))
+			goto noxoff;
+	}
+
+	/* Hold lock while accessing xoff */
+	spin_lock_bh(&caifd->flow_lock);
+	if (caifd->xoff) {
+		spin_unlock_bh(&caifd->flow_lock);
+		goto noxoff;
+	}
+
+	/*
+	 * Handle flow off, we do this by temporary hi-jacking this
+	 * skb's destructor function, and replace it with our own
+	 * flow-on callback. The callback will set flow-on and call
+	 * the original destructor.
+	 */
+
+	pr_debug("queue has stopped(%d) or is full (%d > %d)\n",
+			netif_queue_stopped(caifd->netdev),
+			qlen, high);
+	caifd->xoff = true;
+	caifd->xoff_skb = skb;
+	caifd->xoff_skb_dtor = skb->destructor;
+	skb->destructor = caif_flow_cb;
+	spin_unlock_bh(&caifd->flow_lock);
+
+	caifd->layer.up->ctrlcmd(caifd->layer.up,
+					_CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND,
+					caifd->layer.id);
+noxoff:
+	rcu_read_unlock_bh();
+
+	err = dev_queue_xmit(skb);
+	if (err > 0)
+		err = -EIO;
+
+	return err;
+}
+
+/*
+ * Stuff received packets into the CAIF stack.
+ * On error, returns non-zero and releases the skb.
+ */
+static int receive(struct sk_buff *skb, struct net_device *dev,
+		   struct packet_type *pkttype, struct net_device *orig_dev)
+{
+	struct cfpkt *pkt;
+	struct caif_device_entry *caifd;
+	int err;
+
+	pkt = cfpkt_fromnative(CAIF_DIR_IN, skb);
+
+	rcu_read_lock();
+	caifd = caif_get(dev);
+
+	if (!caifd || !caifd->layer.up || !caifd->layer.up->receive ||
+			!netif_oper_up(caifd->netdev)) {
+		rcu_read_unlock();
+		kfree_skb(skb);
+		return NET_RX_DROP;
+	}
+
+	/* Hold reference to netdevice while using CAIF stack */
+	caifd_hold(caifd);
+	rcu_read_unlock();
+
+	err = caifd->layer.up->receive(caifd->layer.up, pkt);
+
+	/* For -EILSEQ the packet is not freed so free it now */
+	if (err == -EILSEQ)
+		cfpkt_destroy(pkt);
+
+	/* Release reference to stack upwards */
+	caifd_put(caifd);
+
+	if (err != 0)
+		err = NET_RX_DROP;
+	return err;
+}
+
+static struct packet_type caif_packet_type __read_mostly = {
+	.type = cpu_to_be16(ETH_P_CAIF),
+	.func = receive,
+};
+
+static void dev_flowctrl(struct net_device *dev, int on)
+{
+	struct caif_device_entry *caifd;
+
+	rcu_read_lock();
+
+	caifd = caif_get(dev);
+	if (!caifd || !caifd->layer.up || !caifd->layer.up->ctrlcmd) {
+		rcu_read_unlock();
+		return;
+	}
+
+	caifd_hold(caifd);
+	rcu_read_unlock();
+
+	caifd->layer.up->ctrlcmd(caifd->layer.up,
+				 on ?
+				 _CAIF_CTRLCMD_PHYIF_FLOW_ON_IND :
+				 _CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND,
+				 caifd->layer.id);
+	caifd_put(caifd);
+}
+
+int caif_enroll_dev(struct net_device *dev, struct caif_dev_common *caifdev,
+		     struct cflayer *link_support, int head_room,
+		     struct cflayer **layer,
+		     int (**rcv_func)(struct sk_buff *, struct net_device *,
+				      struct packet_type *,
+				      struct net_device *))
+{
+	struct caif_device_entry *caifd;
+	enum cfcnfg_phy_preference pref;
+	struct cfcnfg *cfg = get_cfcnfg(dev_net(dev));
+	struct caif_device_entry_list *caifdevs;
+	int res;
+
+	caifdevs = caif_device_list(dev_net(dev));
+	caifd = caif_device_alloc(dev);
+	if (!caifd)
+		return -ENOMEM;
+	*layer = &caifd->layer;
+	spin_lock_init(&caifd->flow_lock);
+
+	switch (caifdev->link_select) {
+	case CAIF_LINK_HIGH_BANDW:
+		pref = CFPHYPREF_HIGH_BW;
+		break;
+	case CAIF_LINK_LOW_LATENCY:
+		pref = CFPHYPREF_LOW_LAT;
+		break;
+	default:
+		pref = CFPHYPREF_HIGH_BW;
+		break;
+	}
+	mutex_lock(&caifdevs->lock);
+	list_add_rcu(&caifd->list, &caifdevs->list);
+
+	strscpy(caifd->layer.name, dev->name,
+		sizeof(caifd->layer.name));
+	caifd->layer.transmit = transmit;
+	res = cfcnfg_add_phy_layer(cfg,
+				dev,
+				&caifd->layer,
+				pref,
+				link_support,
+				caifdev->use_fcs,
+				head_room);
+	mutex_unlock(&caifdevs->lock);
+	if (rcv_func)
+		*rcv_func = receive;
+	return res;
+}
+EXPORT_SYMBOL(caif_enroll_dev);
+
+/* notify Caif of device events */
+static int caif_device_notify(struct notifier_block *me, unsigned long what,
+			      void *ptr)
+{
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+	struct caif_device_entry *caifd = NULL;
+	struct caif_dev_common *caifdev;
+	struct cfcnfg *cfg;
+	struct cflayer *layer, *link_support;
+	int head_room = 0;
+	struct caif_device_entry_list *caifdevs;
+	int res;
+
+	cfg = get_cfcnfg(dev_net(dev));
+	caifdevs = caif_device_list(dev_net(dev));
+
+	caifd = caif_get(dev);
+	if (caifd == NULL && dev->type != ARPHRD_CAIF)
+		return 0;
+
+	switch (what) {
+	case NETDEV_REGISTER:
+		if (caifd != NULL)
+			break;
+
+		caifdev = netdev_priv(dev);
+
+		link_support = NULL;
+		if (caifdev->use_frag) {
+			head_room = 1;
+			link_support = cfserl_create(dev->ifindex,
+							caifdev->use_stx);
+			if (!link_support) {
+				pr_warn("Out of memory\n");
+				break;
+			}
+		}
+		res = caif_enroll_dev(dev, caifdev, link_support, head_room,
+				&layer, NULL);
+		if (res)
+			cfserl_release(link_support);
+		caifdev->flowctrl = dev_flowctrl;
+		break;
+
+	case NETDEV_UP:
+		rcu_read_lock();
+
+		caifd = caif_get(dev);
+		if (caifd == NULL) {
+			rcu_read_unlock();
+			break;
+		}
+
+		caifd->xoff = false;
+		cfcnfg_set_phy_state(cfg, &caifd->layer, true);
+		rcu_read_unlock();
+
+		break;
+
+	case NETDEV_DOWN:
+		rcu_read_lock();
+
+		caifd = caif_get(dev);
+		if (!caifd || !caifd->layer.up || !caifd->layer.up->ctrlcmd) {
+			rcu_read_unlock();
+			return -EINVAL;
+		}
+
+		cfcnfg_set_phy_state(cfg, &caifd->layer, false);
+		caifd_hold(caifd);
+		rcu_read_unlock();
+
+		caifd->layer.up->ctrlcmd(caifd->layer.up,
+					 _CAIF_CTRLCMD_PHYIF_DOWN_IND,
+					 caifd->layer.id);
+
+		spin_lock_bh(&caifd->flow_lock);
+
+		/*
+		 * Replace our xoff-destructor with original destructor.
+		 * We trust that skb->destructor *always* is called before
+		 * the skb reference is invalid. The hijacked SKB destructor
+		 * takes the flow_lock so manipulating the skb->destructor here
+		 * should be safe.
+		*/
+		if (caifd->xoff_skb_dtor != NULL && caifd->xoff_skb != NULL)
+			caifd->xoff_skb->destructor = caifd->xoff_skb_dtor;
+
+		caifd->xoff = false;
+		caifd->xoff_skb_dtor = NULL;
+		caifd->xoff_skb = NULL;
+
+		spin_unlock_bh(&caifd->flow_lock);
+		caifd_put(caifd);
+		break;
+
+	case NETDEV_UNREGISTER:
+		mutex_lock(&caifdevs->lock);
+
+		caifd = caif_get(dev);
+		if (caifd == NULL) {
+			mutex_unlock(&caifdevs->lock);
+			break;
+		}
+		list_del_rcu(&caifd->list);
+
+		/*
+		 * NETDEV_UNREGISTER is called repeatedly until all reference
+		 * counts for the net-device are released. If references to
+		 * caifd is taken, simply ignore NETDEV_UNREGISTER and wait for
+		 * the next call to NETDEV_UNREGISTER.
+		 *
+		 * If any packets are in flight down the CAIF Stack,
+		 * cfcnfg_del_phy_layer will return nonzero.
+		 * If no packets are in flight, the CAIF Stack associated
+		 * with the net-device un-registering is freed.
+		 */
+
+		if (caifd_refcnt_read(caifd) != 0 ||
+			cfcnfg_del_phy_layer(cfg, &caifd->layer) != 0) {
+
+			pr_info("Wait for device inuse\n");
+			/* Enrole device if CAIF Stack is still in use */
+			list_add_rcu(&caifd->list, &caifdevs->list);
+			mutex_unlock(&caifdevs->lock);
+			break;
+		}
+
+		synchronize_rcu();
+		dev_put(caifd->netdev);
+		free_percpu(caifd->pcpu_refcnt);
+		kfree(caifd);
+
+		mutex_unlock(&caifdevs->lock);
+		break;
+	}
+	return 0;
+}
+
+static struct notifier_block caif_device_notifier = {
+	.notifier_call = caif_device_notify,
+	.priority = 0,
+};
+
+/* Per-namespace Caif devices handling */
+static int caif_init_net(struct net *net)
+{
+	struct caif_net *caifn = net_generic(net, caif_net_id);
+	INIT_LIST_HEAD(&caifn->caifdevs.list);
+	mutex_init(&caifn->caifdevs.lock);
+
+	caifn->cfg = cfcnfg_create();
+	if (!caifn->cfg)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static void caif_exit_net(struct net *net)
+{
+	struct caif_device_entry *caifd, *tmp;
+	struct caif_device_entry_list *caifdevs =
+	    caif_device_list(net);
+	struct cfcnfg *cfg =  get_cfcnfg(net);
+
+	rtnl_lock();
+	mutex_lock(&caifdevs->lock);
+
+	list_for_each_entry_safe(caifd, tmp, &caifdevs->list, list) {
+		int i = 0;
+		list_del_rcu(&caifd->list);
+		cfcnfg_set_phy_state(cfg, &caifd->layer, false);
+
+		while (i < 10 &&
+			(caifd_refcnt_read(caifd) != 0 ||
+			cfcnfg_del_phy_layer(cfg, &caifd->layer) != 0)) {
+
+			pr_info("Wait for device inuse\n");
+			msleep(250);
+			i++;
+		}
+		synchronize_rcu();
+		dev_put(caifd->netdev);
+		free_percpu(caifd->pcpu_refcnt);
+		kfree(caifd);
+	}
+	cfcnfg_remove(cfg);
+
+	mutex_unlock(&caifdevs->lock);
+	rtnl_unlock();
+}
+
+static struct pernet_operations caif_net_ops = {
+	.init = caif_init_net,
+	.exit = caif_exit_net,
+	.id   = &caif_net_id,
+	.size = sizeof(struct caif_net),
+};
+
+/* Initialize Caif devices list */
+static int __init caif_device_init(void)
+{
+	int result;
+
+	result = register_pernet_subsys(&caif_net_ops);
+
+	if (result)
+		return result;
+
+	register_netdevice_notifier(&caif_device_notifier);
+	dev_add_pack(&caif_packet_type);
+
+	return result;
+}
+
+static void __exit caif_device_exit(void)
+{
+	unregister_netdevice_notifier(&caif_device_notifier);
+	dev_remove_pack(&caif_packet_type);
+	unregister_pernet_subsys(&caif_net_ops);
+}
+
+module_init(caif_device_init);
+module_exit(caif_device_exit);
diff --git a/net/caif/caif_socket.c b/net/caif/caif_socket.c
new file mode 100644
index 000000000..78c9729a6
--- /dev/null
+++ b/net/caif/caif_socket.c
@@ -0,0 +1,1119 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) ST-Ericsson AB 2010
+ * Author:	Sjur Brendeland
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
+
+#include <linux/filter.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/sched/signal.h>
+#include <linux/spinlock.h>
+#include <linux/mutex.h>
+#include <linux/list.h>
+#include <linux/wait.h>
+#include <linux/poll.h>
+#include <linux/tcp.h>
+#include <linux/uaccess.h>
+#include <linux/debugfs.h>
+#include <linux/caif/caif_socket.h>
+#include <linux/pkt_sched.h>
+#include <net/sock.h>
+#include <net/tcp_states.h>
+#include <net/caif/caif_layer.h>
+#include <net/caif/caif_dev.h>
+#include <net/caif/cfpkt.h>
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_NETPROTO(AF_CAIF);
+
+/*
+ * CAIF state is re-using the TCP socket states.
+ * caif_states stored in sk_state reflect the state as reported by
+ * the CAIF stack, while sk_socket->state is the state of the socket.
+ */
+enum caif_states {
+	CAIF_CONNECTED		= TCP_ESTABLISHED,
+	CAIF_CONNECTING	= TCP_SYN_SENT,
+	CAIF_DISCONNECTED	= TCP_CLOSE
+};
+
+#define TX_FLOW_ON_BIT	1
+#define RX_FLOW_ON_BIT	2
+
+struct caifsock {
+	struct sock sk; /* must be first member */
+	struct cflayer layer;
+	unsigned long flow_state;
+	struct caif_connect_request conn_req;
+	struct mutex readlock;
+	struct dentry *debugfs_socket_dir;
+	int headroom, tailroom, maxframe;
+};
+
+static int rx_flow_is_on(struct caifsock *cf_sk)
+{
+	return test_bit(RX_FLOW_ON_BIT, &cf_sk->flow_state);
+}
+
+static int tx_flow_is_on(struct caifsock *cf_sk)
+{
+	return test_bit(TX_FLOW_ON_BIT, &cf_sk->flow_state);
+}
+
+static void set_rx_flow_off(struct caifsock *cf_sk)
+{
+	clear_bit(RX_FLOW_ON_BIT, &cf_sk->flow_state);
+}
+
+static void set_rx_flow_on(struct caifsock *cf_sk)
+{
+	set_bit(RX_FLOW_ON_BIT, &cf_sk->flow_state);
+}
+
+static void set_tx_flow_off(struct caifsock *cf_sk)
+{
+	clear_bit(TX_FLOW_ON_BIT, &cf_sk->flow_state);
+}
+
+static void set_tx_flow_on(struct caifsock *cf_sk)
+{
+	set_bit(TX_FLOW_ON_BIT, &cf_sk->flow_state);
+}
+
+static void caif_read_lock(struct sock *sk)
+{
+	struct caifsock *cf_sk;
+	cf_sk = container_of(sk, struct caifsock, sk);
+	mutex_lock(&cf_sk->readlock);
+}
+
+static void caif_read_unlock(struct sock *sk)
+{
+	struct caifsock *cf_sk;
+	cf_sk = container_of(sk, struct caifsock, sk);
+	mutex_unlock(&cf_sk->readlock);
+}
+
+static int sk_rcvbuf_lowwater(struct caifsock *cf_sk)
+{
+	/* A quarter of full buffer is used a low water mark */
+	return cf_sk->sk.sk_rcvbuf / 4;
+}
+
+static void caif_flow_ctrl(struct sock *sk, int mode)
+{
+	struct caifsock *cf_sk;
+	cf_sk = container_of(sk, struct caifsock, sk);
+	if (cf_sk->layer.dn && cf_sk->layer.dn->modemcmd)
+		cf_sk->layer.dn->modemcmd(cf_sk->layer.dn, mode);
+}
+
+/*
+ * Copied from sock.c:sock_queue_rcv_skb(), but changed so packets are
+ * not dropped, but CAIF is sending flow off instead.
+ */
+static void caif_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
+{
+	int err;
+	unsigned long flags;
+	struct sk_buff_head *list = &sk->sk_receive_queue;
+	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
+	bool queued = false;
+
+	if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
+		(unsigned int)sk->sk_rcvbuf && rx_flow_is_on(cf_sk)) {
+		net_dbg_ratelimited("sending flow OFF (queue len = %d %d)\n",
+				    atomic_read(&cf_sk->sk.sk_rmem_alloc),
+				    sk_rcvbuf_lowwater(cf_sk));
+		set_rx_flow_off(cf_sk);
+		caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
+	}
+
+	err = sk_filter(sk, skb);
+	if (err)
+		goto out;
+
+	if (!sk_rmem_schedule(sk, skb, skb->truesize) && rx_flow_is_on(cf_sk)) {
+		set_rx_flow_off(cf_sk);
+		net_dbg_ratelimited("sending flow OFF due to rmem_schedule\n");
+		caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
+	}
+	skb->dev = NULL;
+	skb_set_owner_r(skb, sk);
+	spin_lock_irqsave(&list->lock, flags);
+	queued = !sock_flag(sk, SOCK_DEAD);
+	if (queued)
+		__skb_queue_tail(list, skb);
+	spin_unlock_irqrestore(&list->lock, flags);
+out:
+	if (queued)
+		sk->sk_data_ready(sk);
+	else
+		kfree_skb(skb);
+}
+
+/* Packet Receive Callback function called from CAIF Stack */
+static int caif_sktrecv_cb(struct cflayer *layr, struct cfpkt *pkt)
+{
+	struct caifsock *cf_sk;
+	struct sk_buff *skb;
+
+	cf_sk = container_of(layr, struct caifsock, layer);
+	skb = cfpkt_tonative(pkt);
+
+	if (unlikely(cf_sk->sk.sk_state != CAIF_CONNECTED)) {
+		kfree_skb(skb);
+		return 0;
+	}
+	caif_queue_rcv_skb(&cf_sk->sk, skb);
+	return 0;
+}
+
+static void cfsk_hold(struct cflayer *layr)
+{
+	struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
+	sock_hold(&cf_sk->sk);
+}
+
+static void cfsk_put(struct cflayer *layr)
+{
+	struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
+	sock_put(&cf_sk->sk);
+}
+
+/* Packet Control Callback function called from CAIF */
+static void caif_ctrl_cb(struct cflayer *layr,
+			 enum caif_ctrlcmd flow,
+			 int phyid)
+{
+	struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
+	switch (flow) {
+	case CAIF_CTRLCMD_FLOW_ON_IND:
+		/* OK from modem to start sending again */
+		set_tx_flow_on(cf_sk);
+		cf_sk->sk.sk_state_change(&cf_sk->sk);
+		break;
+
+	case CAIF_CTRLCMD_FLOW_OFF_IND:
+		/* Modem asks us to shut up */
+		set_tx_flow_off(cf_sk);
+		cf_sk->sk.sk_state_change(&cf_sk->sk);
+		break;
+
+	case CAIF_CTRLCMD_INIT_RSP:
+		/* We're now connected */
+		caif_client_register_refcnt(&cf_sk->layer,
+						cfsk_hold, cfsk_put);
+		cf_sk->sk.sk_state = CAIF_CONNECTED;
+		set_tx_flow_on(cf_sk);
+		cf_sk->sk.sk_shutdown = 0;
+		cf_sk->sk.sk_state_change(&cf_sk->sk);
+		break;
+
+	case CAIF_CTRLCMD_DEINIT_RSP:
+		/* We're now disconnected */
+		cf_sk->sk.sk_state = CAIF_DISCONNECTED;
+		cf_sk->sk.sk_state_change(&cf_sk->sk);
+		break;
+
+	case CAIF_CTRLCMD_INIT_FAIL_RSP:
+		/* Connect request failed */
+		cf_sk->sk.sk_err = ECONNREFUSED;
+		cf_sk->sk.sk_state = CAIF_DISCONNECTED;
+		cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
+		/*
+		 * Socket "standards" seems to require POLLOUT to
+		 * be set at connect failure.
+		 */
+		set_tx_flow_on(cf_sk);
+		cf_sk->sk.sk_state_change(&cf_sk->sk);
+		break;
+
+	case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
+		/* Modem has closed this connection, or device is down. */
+		cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
+		cf_sk->sk.sk_err = ECONNRESET;
+		set_rx_flow_on(cf_sk);
+		sk_error_report(&cf_sk->sk);
+		break;
+
+	default:
+		pr_debug("Unexpected flow command %d\n", flow);
+	}
+}
+
+static void caif_check_flow_release(struct sock *sk)
+{
+	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
+
+	if (rx_flow_is_on(cf_sk))
+		return;
+
+	if (atomic_read(&sk->sk_rmem_alloc) <= sk_rcvbuf_lowwater(cf_sk)) {
+			set_rx_flow_on(cf_sk);
+			caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_ON_REQ);
+	}
+}
+
+/*
+ * Copied from unix_dgram_recvmsg, but removed credit checks,
+ * changed locking, address handling and added MSG_TRUNC.
+ */
+static int caif_seqpkt_recvmsg(struct socket *sock, struct msghdr *m,
+			       size_t len, int flags)
+
+{
+	struct sock *sk = sock->sk;
+	struct sk_buff *skb;
+	int ret;
+	int copylen;
+
+	ret = -EOPNOTSUPP;
+	if (flags & MSG_OOB)
+		goto read_error;
+
+	skb = skb_recv_datagram(sk, flags, &ret);
+	if (!skb)
+		goto read_error;
+	copylen = skb->len;
+	if (len < copylen) {
+		m->msg_flags |= MSG_TRUNC;
+		copylen = len;
+	}
+
+	ret = skb_copy_datagram_msg(skb, 0, m, copylen);
+	if (ret)
+		goto out_free;
+
+	ret = (flags & MSG_TRUNC) ? skb->len : copylen;
+out_free:
+	skb_free_datagram(sk, skb);
+	caif_check_flow_release(sk);
+	return ret;
+
+read_error:
+	return ret;
+}
+
+
+/* Copied from unix_stream_wait_data, identical except for lock call. */
+static long caif_stream_data_wait(struct sock *sk, long timeo)
+{
+	DEFINE_WAIT(wait);
+	lock_sock(sk);
+
+	for (;;) {
+		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
+
+		if (!skb_queue_empty(&sk->sk_receive_queue) ||
+			sk->sk_err ||
+			sk->sk_state != CAIF_CONNECTED ||
+			sock_flag(sk, SOCK_DEAD) ||
+			(sk->sk_shutdown & RCV_SHUTDOWN) ||
+			signal_pending(current) ||
+			!timeo)
+			break;
+
+		sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
+		release_sock(sk);
+		timeo = schedule_timeout(timeo);
+		lock_sock(sk);
+
+		if (sock_flag(sk, SOCK_DEAD))
+			break;
+
+		sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
+	}
+
+	finish_wait(sk_sleep(sk), &wait);
+	release_sock(sk);
+	return timeo;
+}
+
+
+/*
+ * Copied from unix_stream_recvmsg, but removed credit checks,
+ * changed locking calls, changed address handling.
+ */
+static int caif_stream_recvmsg(struct socket *sock, struct msghdr *msg,
+			       size_t size, int flags)
+{
+	struct sock *sk = sock->sk;
+	int copied = 0;
+	int target;
+	int err = 0;
+	long timeo;
+
+	err = -EOPNOTSUPP;
+	if (flags&MSG_OOB)
+		goto out;
+
+	/*
+	 * Lock the socket to prevent queue disordering
+	 * while sleeps in memcpy_tomsg
+	 */
+	err = -EAGAIN;
+	if (sk->sk_state == CAIF_CONNECTING)
+		goto out;
+
+	caif_read_lock(sk);
+	target = sock_rcvlowat(sk, flags&MSG_WAITALL, size);
+	timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT);
+
+	do {
+		int chunk;
+		struct sk_buff *skb;
+
+		lock_sock(sk);
+		if (sock_flag(sk, SOCK_DEAD)) {
+			err = -ECONNRESET;
+			goto unlock;
+		}
+		skb = skb_dequeue(&sk->sk_receive_queue);
+		caif_check_flow_release(sk);
+
+		if (skb == NULL) {
+			if (copied >= target)
+				goto unlock;
+			/*
+			 *	POSIX 1003.1g mandates this order.
+			 */
+			err = sock_error(sk);
+			if (err)
+				goto unlock;
+			err = -ECONNRESET;
+			if (sk->sk_shutdown & RCV_SHUTDOWN)
+				goto unlock;
+
+			err = -EPIPE;
+			if (sk->sk_state != CAIF_CONNECTED)
+				goto unlock;
+			if (sock_flag(sk, SOCK_DEAD))
+				goto unlock;
+
+			release_sock(sk);
+
+			err = -EAGAIN;
+			if (!timeo)
+				break;
+
+			caif_read_unlock(sk);
+
+			timeo = caif_stream_data_wait(sk, timeo);
+
+			if (signal_pending(current)) {
+				err = sock_intr_errno(timeo);
+				goto out;
+			}
+			caif_read_lock(sk);
+			continue;
+unlock:
+			release_sock(sk);
+			break;
+		}
+		release_sock(sk);
+		chunk = min_t(unsigned int, skb->len, size);
+		if (memcpy_to_msg(msg, skb->data, chunk)) {
+			skb_queue_head(&sk->sk_receive_queue, skb);
+			if (copied == 0)
+				copied = -EFAULT;
+			break;
+		}
+		copied += chunk;
+		size -= chunk;
+
+		/* Mark read part of skb as used */
+		if (!(flags & MSG_PEEK)) {
+			skb_pull(skb, chunk);
+
+			/* put the skb back if we didn't use it up. */
+			if (skb->len) {
+				skb_queue_head(&sk->sk_receive_queue, skb);
+				break;
+			}
+			kfree_skb(skb);
+
+		} else {
+			/*
+			 * It is questionable, see note in unix_dgram_recvmsg.
+			 */
+			/* put message back and return */
+			skb_queue_head(&sk->sk_receive_queue, skb);
+			break;
+		}
+	} while (size);
+	caif_read_unlock(sk);
+
+out:
+	return copied ? : err;
+}
+
+/*
+ * Copied from sock.c:sock_wait_for_wmem, but change to wait for
+ * CAIF flow-on and sock_writable.
+ */
+static long caif_wait_for_flow_on(struct caifsock *cf_sk,
+				  int wait_writeable, long timeo, int *err)
+{
+	struct sock *sk = &cf_sk->sk;
+	DEFINE_WAIT(wait);
+	for (;;) {
+		*err = 0;
+		if (tx_flow_is_on(cf_sk) &&
+			(!wait_writeable || sock_writeable(&cf_sk->sk)))
+			break;
+		*err = -ETIMEDOUT;
+		if (!timeo)
+			break;
+		*err = -ERESTARTSYS;
+		if (signal_pending(current))
+			break;
+		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
+		*err = -ECONNRESET;
+		if (sk->sk_shutdown & SHUTDOWN_MASK)
+			break;
+		*err = -sk->sk_err;
+		if (sk->sk_err)
+			break;
+		*err = -EPIPE;
+		if (cf_sk->sk.sk_state != CAIF_CONNECTED)
+			break;
+		timeo = schedule_timeout(timeo);
+	}
+	finish_wait(sk_sleep(sk), &wait);
+	return timeo;
+}
+
+/*
+ * Transmit a SKB. The device may temporarily request re-transmission
+ * by returning EAGAIN.
+ */
+static int transmit_skb(struct sk_buff *skb, struct caifsock *cf_sk,
+			int noblock, long timeo)
+{
+	struct cfpkt *pkt;
+
+	pkt = cfpkt_fromnative(CAIF_DIR_OUT, skb);
+	memset(skb->cb, 0, sizeof(struct caif_payload_info));
+	cfpkt_set_prio(pkt, cf_sk->sk.sk_priority);
+
+	if (cf_sk->layer.dn == NULL) {
+		kfree_skb(skb);
+		return -EINVAL;
+	}
+
+	return cf_sk->layer.dn->transmit(cf_sk->layer.dn, pkt);
+}
+
+/* Copied from af_unix:unix_dgram_sendmsg, and adapted to CAIF */
+static int caif_seqpkt_sendmsg(struct socket *sock, struct msghdr *msg,
+			       size_t len)
+{
+	struct sock *sk = sock->sk;
+	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
+	int buffer_size;
+	int ret = 0;
+	struct sk_buff *skb = NULL;
+	int noblock;
+	long timeo;
+	caif_assert(cf_sk);
+	ret = sock_error(sk);
+	if (ret)
+		goto err;
+
+	ret = -EOPNOTSUPP;
+	if (msg->msg_flags&MSG_OOB)
+		goto err;
+
+	ret = -EOPNOTSUPP;
+	if (msg->msg_namelen)
+		goto err;
+
+	ret = -EINVAL;
+	if (unlikely(msg->msg_iter.nr_segs == 0) ||
+	    unlikely(msg->msg_iter.iov->iov_base == NULL))
+		goto err;
+	noblock = msg->msg_flags & MSG_DONTWAIT;
+
+	timeo = sock_sndtimeo(sk, noblock);
+	timeo = caif_wait_for_flow_on(container_of(sk, struct caifsock, sk),
+				1, timeo, &ret);
+
+	if (ret)
+		goto err;
+	ret = -EPIPE;
+	if (cf_sk->sk.sk_state != CAIF_CONNECTED ||
+		sock_flag(sk, SOCK_DEAD) ||
+		(sk->sk_shutdown & RCV_SHUTDOWN))
+		goto err;
+
+	/* Error if trying to write more than maximum frame size. */
+	ret = -EMSGSIZE;
+	if (len > cf_sk->maxframe && cf_sk->sk.sk_protocol != CAIFPROTO_RFM)
+		goto err;
+
+	buffer_size = len + cf_sk->headroom + cf_sk->tailroom;
+
+	ret = -ENOMEM;
+	skb = sock_alloc_send_skb(sk, buffer_size, noblock, &ret);
+
+	if (!skb || skb_tailroom(skb) < buffer_size)
+		goto err;
+
+	skb_reserve(skb, cf_sk->headroom);
+
+	ret = memcpy_from_msg(skb_put(skb, len), msg, len);
+
+	if (ret)
+		goto err;
+	ret = transmit_skb(skb, cf_sk, noblock, timeo);
+	if (ret < 0)
+		/* skb is already freed */
+		return ret;
+
+	return len;
+err:
+	kfree_skb(skb);
+	return ret;
+}
+
+/*
+ * Copied from unix_stream_sendmsg and adapted to CAIF:
+ * Changed removed permission handling and added waiting for flow on
+ * and other minor adaptations.
+ */
+static int caif_stream_sendmsg(struct socket *sock, struct msghdr *msg,
+			       size_t len)
+{
+	struct sock *sk = sock->sk;
+	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
+	int err, size;
+	struct sk_buff *skb;
+	int sent = 0;
+	long timeo;
+
+	err = -EOPNOTSUPP;
+	if (unlikely(msg->msg_flags&MSG_OOB))
+		goto out_err;
+
+	if (unlikely(msg->msg_namelen))
+		goto out_err;
+
+	timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
+	timeo = caif_wait_for_flow_on(cf_sk, 1, timeo, &err);
+
+	if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN))
+		goto pipe_err;
+
+	while (sent < len) {
+
+		size = len-sent;
+
+		if (size > cf_sk->maxframe)
+			size = cf_sk->maxframe;
+
+		/* If size is more than half of sndbuf, chop up message */
+		if (size > ((sk->sk_sndbuf >> 1) - 64))
+			size = (sk->sk_sndbuf >> 1) - 64;
+
+		if (size > SKB_MAX_ALLOC)
+			size = SKB_MAX_ALLOC;
+
+		skb = sock_alloc_send_skb(sk,
+					size + cf_sk->headroom +
+					cf_sk->tailroom,
+					msg->msg_flags&MSG_DONTWAIT,
+					&err);
+		if (skb == NULL)
+			goto out_err;
+
+		skb_reserve(skb, cf_sk->headroom);
+		/*
+		 *	If you pass two values to the sock_alloc_send_skb
+		 *	it tries to grab the large buffer with GFP_NOFS
+		 *	(which can fail easily), and if it fails grab the
+		 *	fallback size buffer which is under a page and will
+		 *	succeed. [Alan]
+		 */
+		size = min_t(int, size, skb_tailroom(skb));
+
+		err = memcpy_from_msg(skb_put(skb, size), msg, size);
+		if (err) {
+			kfree_skb(skb);
+			goto out_err;
+		}
+		err = transmit_skb(skb, cf_sk,
+				msg->msg_flags&MSG_DONTWAIT, timeo);
+		if (err < 0)
+			/* skb is already freed */
+			goto pipe_err;
+
+		sent += size;
+	}
+
+	return sent;
+
+pipe_err:
+	if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL))
+		send_sig(SIGPIPE, current, 0);
+	err = -EPIPE;
+out_err:
+	return sent ? : err;
+}
+
+static int setsockopt(struct socket *sock, int lvl, int opt, sockptr_t ov,
+		unsigned int ol)
+{
+	struct sock *sk = sock->sk;
+	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
+	int linksel;
+
+	if (cf_sk->sk.sk_socket->state != SS_UNCONNECTED)
+		return -ENOPROTOOPT;
+
+	switch (opt) {
+	case CAIFSO_LINK_SELECT:
+		if (ol < sizeof(int))
+			return -EINVAL;
+		if (lvl != SOL_CAIF)
+			goto bad_sol;
+		if (copy_from_sockptr(&linksel, ov, sizeof(int)))
+			return -EINVAL;
+		lock_sock(&(cf_sk->sk));
+		cf_sk->conn_req.link_selector = linksel;
+		release_sock(&cf_sk->sk);
+		return 0;
+
+	case CAIFSO_REQ_PARAM:
+		if (lvl != SOL_CAIF)
+			goto bad_sol;
+		if (cf_sk->sk.sk_protocol != CAIFPROTO_UTIL)
+			return -ENOPROTOOPT;
+		lock_sock(&(cf_sk->sk));
+		if (ol > sizeof(cf_sk->conn_req.param.data) ||
+		    copy_from_sockptr(&cf_sk->conn_req.param.data, ov, ol)) {
+			release_sock(&cf_sk->sk);
+			return -EINVAL;
+		}
+		cf_sk->conn_req.param.size = ol;
+		release_sock(&cf_sk->sk);
+		return 0;
+
+	default:
+		return -ENOPROTOOPT;
+	}
+
+	return 0;
+bad_sol:
+	return -ENOPROTOOPT;
+
+}
+
+/*
+ * caif_connect() - Connect a CAIF Socket
+ * Copied and modified af_irda.c:irda_connect().
+ *
+ * Note : by consulting "errno", the user space caller may learn the cause
+ * of the failure. Most of them are visible in the function, others may come
+ * from subroutines called and are listed here :
+ *  o -EAFNOSUPPORT: bad socket family or type.
+ *  o -ESOCKTNOSUPPORT: bad socket type or protocol
+ *  o -EINVAL: bad socket address, or CAIF link type
+ *  o -ECONNREFUSED: remote end refused the connection.
+ *  o -EINPROGRESS: connect request sent but timed out (or non-blocking)
+ *  o -EISCONN: already connected.
+ *  o -ETIMEDOUT: Connection timed out (send timeout)
+ *  o -ENODEV: No link layer to send request
+ *  o -ECONNRESET: Received Shutdown indication or lost link layer
+ *  o -ENOMEM: Out of memory
+ *
+ *  State Strategy:
+ *  o sk_state: holds the CAIF_* protocol state, it's updated by
+ *	caif_ctrl_cb.
+ *  o sock->state: holds the SS_* socket state and is updated by connect and
+ *	disconnect.
+ */
+static int caif_connect(struct socket *sock, struct sockaddr *uaddr,
+			int addr_len, int flags)
+{
+	struct sock *sk = sock->sk;
+	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
+	long timeo;
+	int err;
+	int ifindex, headroom, tailroom;
+	unsigned int mtu;
+	struct net_device *dev;
+
+	lock_sock(sk);
+
+	err = -EINVAL;
+	if (addr_len < offsetofend(struct sockaddr, sa_family))
+		goto out;
+
+	err = -EAFNOSUPPORT;
+	if (uaddr->sa_family != AF_CAIF)
+		goto out;
+
+	switch (sock->state) {
+	case SS_UNCONNECTED:
+		/* Normal case, a fresh connect */
+		caif_assert(sk->sk_state == CAIF_DISCONNECTED);
+		break;
+	case SS_CONNECTING:
+		switch (sk->sk_state) {
+		case CAIF_CONNECTED:
+			sock->state = SS_CONNECTED;
+			err = -EISCONN;
+			goto out;
+		case CAIF_DISCONNECTED:
+			/* Reconnect allowed */
+			break;
+		case CAIF_CONNECTING:
+			err = -EALREADY;
+			if (flags & O_NONBLOCK)
+				goto out;
+			goto wait_connect;
+		}
+		break;
+	case SS_CONNECTED:
+		caif_assert(sk->sk_state == CAIF_CONNECTED ||
+				sk->sk_state == CAIF_DISCONNECTED);
+		if (sk->sk_shutdown & SHUTDOWN_MASK) {
+			/* Allow re-connect after SHUTDOWN_IND */
+			caif_disconnect_client(sock_net(sk), &cf_sk->layer);
+			caif_free_client(&cf_sk->layer);
+			break;
+		}
+		/* No reconnect on a seqpacket socket */
+		err = -EISCONN;
+		goto out;
+	case SS_DISCONNECTING:
+	case SS_FREE:
+		caif_assert(1); /*Should never happen */
+		break;
+	}
+	sk->sk_state = CAIF_DISCONNECTED;
+	sock->state = SS_UNCONNECTED;
+	sk_stream_kill_queues(&cf_sk->sk);
+
+	err = -EINVAL;
+	if (addr_len != sizeof(struct sockaddr_caif))
+		goto out;
+
+	memcpy(&cf_sk->conn_req.sockaddr, uaddr,
+		sizeof(struct sockaddr_caif));
+
+	/* Move to connecting socket, start sending Connect Requests */
+	sock->state = SS_CONNECTING;
+	sk->sk_state = CAIF_CONNECTING;
+
+	/* Check priority value comming from socket */
+	/* if priority value is out of range it will be ajusted */
+	if (cf_sk->sk.sk_priority > CAIF_PRIO_MAX)
+		cf_sk->conn_req.priority = CAIF_PRIO_MAX;
+	else if (cf_sk->sk.sk_priority < CAIF_PRIO_MIN)
+		cf_sk->conn_req.priority = CAIF_PRIO_MIN;
+	else
+		cf_sk->conn_req.priority = cf_sk->sk.sk_priority;
+
+	/*ifindex = id of the interface.*/
+	cf_sk->conn_req.ifindex = cf_sk->sk.sk_bound_dev_if;
+
+	cf_sk->layer.receive = caif_sktrecv_cb;
+
+	err = caif_connect_client(sock_net(sk), &cf_sk->conn_req,
+				&cf_sk->layer, &ifindex, &headroom, &tailroom);
+
+	if (err < 0) {
+		cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
+		cf_sk->sk.sk_state = CAIF_DISCONNECTED;
+		goto out;
+	}
+
+	err = -ENODEV;
+	rcu_read_lock();
+	dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
+	if (!dev) {
+		rcu_read_unlock();
+		goto out;
+	}
+	cf_sk->headroom = LL_RESERVED_SPACE_EXTRA(dev, headroom);
+	mtu = dev->mtu;
+	rcu_read_unlock();
+
+	cf_sk->tailroom = tailroom;
+	cf_sk->maxframe = mtu - (headroom + tailroom);
+	if (cf_sk->maxframe < 1) {
+		pr_warn("CAIF Interface MTU too small (%d)\n", dev->mtu);
+		err = -ENODEV;
+		goto out;
+	}
+
+	err = -EINPROGRESS;
+wait_connect:
+
+	if (sk->sk_state != CAIF_CONNECTED && (flags & O_NONBLOCK))
+		goto out;
+
+	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
+
+	release_sock(sk);
+	err = -ERESTARTSYS;
+	timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
+			sk->sk_state != CAIF_CONNECTING,
+			timeo);
+	lock_sock(sk);
+	if (timeo < 0)
+		goto out; /* -ERESTARTSYS */
+
+	err = -ETIMEDOUT;
+	if (timeo == 0 && sk->sk_state != CAIF_CONNECTED)
+		goto out;
+	if (sk->sk_state != CAIF_CONNECTED) {
+		sock->state = SS_UNCONNECTED;
+		err = sock_error(sk);
+		if (!err)
+			err = -ECONNREFUSED;
+		goto out;
+	}
+	sock->state = SS_CONNECTED;
+	err = 0;
+out:
+	release_sock(sk);
+	return err;
+}
+
+/*
+ * caif_release() - Disconnect a CAIF Socket
+ * Copied and modified af_irda.c:irda_release().
+ */
+static int caif_release(struct socket *sock)
+{
+	struct sock *sk = sock->sk;
+	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
+
+	if (!sk)
+		return 0;
+
+	set_tx_flow_off(cf_sk);
+
+	/*
+	 * Ensure that packets are not queued after this point in time.
+	 * caif_queue_rcv_skb checks SOCK_DEAD holding the queue lock,
+	 * this ensures no packets when sock is dead.
+	 */
+	spin_lock_bh(&sk->sk_receive_queue.lock);
+	sock_set_flag(sk, SOCK_DEAD);
+	spin_unlock_bh(&sk->sk_receive_queue.lock);
+	sock->sk = NULL;
+
+	WARN_ON(IS_ERR(cf_sk->debugfs_socket_dir));
+	debugfs_remove_recursive(cf_sk->debugfs_socket_dir);
+
+	lock_sock(&(cf_sk->sk));
+	sk->sk_state = CAIF_DISCONNECTED;
+	sk->sk_shutdown = SHUTDOWN_MASK;
+
+	caif_disconnect_client(sock_net(sk), &cf_sk->layer);
+	cf_sk->sk.sk_socket->state = SS_DISCONNECTING;
+	wake_up_interruptible_poll(sk_sleep(sk), EPOLLERR|EPOLLHUP);
+
+	sock_orphan(sk);
+	sk_stream_kill_queues(&cf_sk->sk);
+	release_sock(sk);
+	sock_put(sk);
+	return 0;
+}
+
+/* Copied from af_unix.c:unix_poll(), added CAIF tx_flow handling */
+static __poll_t caif_poll(struct file *file,
+			      struct socket *sock, poll_table *wait)
+{
+	struct sock *sk = sock->sk;
+	__poll_t mask;
+	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
+
+	sock_poll_wait(file, sock, wait);
+	mask = 0;
+
+	/* exceptional events? */
+	if (sk->sk_err)
+		mask |= EPOLLERR;
+	if (sk->sk_shutdown == SHUTDOWN_MASK)
+		mask |= EPOLLHUP;
+	if (sk->sk_shutdown & RCV_SHUTDOWN)
+		mask |= EPOLLRDHUP;
+
+	/* readable? */
+	if (!skb_queue_empty_lockless(&sk->sk_receive_queue) ||
+		(sk->sk_shutdown & RCV_SHUTDOWN))
+		mask |= EPOLLIN | EPOLLRDNORM;
+
+	/*
+	 * we set writable also when the other side has shut down the
+	 * connection. This prevents stuck sockets.
+	 */
+	if (sock_writeable(sk) && tx_flow_is_on(cf_sk))
+		mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
+
+	return mask;
+}
+
+static const struct proto_ops caif_seqpacket_ops = {
+	.family = PF_CAIF,
+	.owner = THIS_MODULE,
+	.release = caif_release,
+	.bind = sock_no_bind,
+	.connect = caif_connect,
+	.socketpair = sock_no_socketpair,
+	.accept = sock_no_accept,
+	.getname = sock_no_getname,
+	.poll = caif_poll,
+	.ioctl = sock_no_ioctl,
+	.listen = sock_no_listen,
+	.shutdown = sock_no_shutdown,
+	.setsockopt = setsockopt,
+	.sendmsg = caif_seqpkt_sendmsg,
+	.recvmsg = caif_seqpkt_recvmsg,
+	.mmap = sock_no_mmap,
+	.sendpage = sock_no_sendpage,
+};
+
+static const struct proto_ops caif_stream_ops = {
+	.family = PF_CAIF,
+	.owner = THIS_MODULE,
+	.release = caif_release,
+	.bind = sock_no_bind,
+	.connect = caif_connect,
+	.socketpair = sock_no_socketpair,
+	.accept = sock_no_accept,
+	.getname = sock_no_getname,
+	.poll = caif_poll,
+	.ioctl = sock_no_ioctl,
+	.listen = sock_no_listen,
+	.shutdown = sock_no_shutdown,
+	.setsockopt = setsockopt,
+	.sendmsg = caif_stream_sendmsg,
+	.recvmsg = caif_stream_recvmsg,
+	.mmap = sock_no_mmap,
+	.sendpage = sock_no_sendpage,
+};
+
+/* This function is called when a socket is finally destroyed. */
+static void caif_sock_destructor(struct sock *sk)
+{
+	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
+	caif_assert(!refcount_read(&sk->sk_wmem_alloc));
+	caif_assert(sk_unhashed(sk));
+	caif_assert(!sk->sk_socket);
+	if (!sock_flag(sk, SOCK_DEAD)) {
+		pr_debug("Attempt to release alive CAIF socket: %p\n", sk);
+		return;
+	}
+	sk_stream_kill_queues(&cf_sk->sk);
+	WARN_ON_ONCE(sk->sk_forward_alloc);
+	caif_free_client(&cf_sk->layer);
+}
+
+static int caif_create(struct net *net, struct socket *sock, int protocol,
+		       int kern)
+{
+	struct sock *sk = NULL;
+	struct caifsock *cf_sk = NULL;
+	static struct proto prot = {.name = "PF_CAIF",
+		.owner = THIS_MODULE,
+		.obj_size = sizeof(struct caifsock),
+		.useroffset = offsetof(struct caifsock, conn_req.param),
+		.usersize = sizeof_field(struct caifsock, conn_req.param)
+	};
+
+	if (!capable(CAP_SYS_ADMIN) && !capable(CAP_NET_ADMIN))
+		return -EPERM;
+	/*
+	 * The sock->type specifies the socket type to use.
+	 * The CAIF socket is a packet stream in the sense
+	 * that it is packet based. CAIF trusts the reliability
+	 * of the link, no resending is implemented.
+	 */
+	if (sock->type == SOCK_SEQPACKET)
+		sock->ops = &caif_seqpacket_ops;
+	else if (sock->type == SOCK_STREAM)
+		sock->ops = &caif_stream_ops;
+	else
+		return -ESOCKTNOSUPPORT;
+
+	if (protocol < 0 || protocol >= CAIFPROTO_MAX)
+		return -EPROTONOSUPPORT;
+	/*
+	 * Set the socket state to unconnected.	 The socket state
+	 * is really not used at all in the net/core or socket.c but the
+	 * initialization makes sure that sock->state is not uninitialized.
+	 */
+	sk = sk_alloc(net, PF_CAIF, GFP_KERNEL, &prot, kern);
+	if (!sk)
+		return -ENOMEM;
+
+	cf_sk = container_of(sk, struct caifsock, sk);
+
+	/* Store the protocol */
+	sk->sk_protocol = (unsigned char) protocol;
+
+	/* Initialize default priority for well-known cases */
+	switch (protocol) {
+	case CAIFPROTO_AT:
+		sk->sk_priority = TC_PRIO_CONTROL;
+		break;
+	case CAIFPROTO_RFM:
+		sk->sk_priority = TC_PRIO_INTERACTIVE_BULK;
+		break;
+	default:
+		sk->sk_priority = TC_PRIO_BESTEFFORT;
+	}
+
+	/*
+	 * Lock in order to try to stop someone from opening the socket
+	 * too early.
+	 */
+	lock_sock(&(cf_sk->sk));
+
+	/* Initialize the nozero default sock structure data. */
+	sock_init_data(sock, sk);
+	sk->sk_destruct = caif_sock_destructor;
+
+	mutex_init(&cf_sk->readlock); /* single task reading lock */
+	cf_sk->layer.ctrlcmd = caif_ctrl_cb;
+	cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
+	cf_sk->sk.sk_state = CAIF_DISCONNECTED;
+
+	set_tx_flow_off(cf_sk);
+	set_rx_flow_on(cf_sk);
+
+	/* Set default options on configuration */
+	cf_sk->conn_req.link_selector = CAIF_LINK_LOW_LATENCY;
+	cf_sk->conn_req.protocol = protocol;
+	release_sock(&cf_sk->sk);
+	return 0;
+}
+
+
+static const struct net_proto_family caif_family_ops = {
+	.family = PF_CAIF,
+	.create = caif_create,
+	.owner = THIS_MODULE,
+};
+
+static int __init caif_sktinit_module(void)
+{
+	return sock_register(&caif_family_ops);
+}
+
+static void __exit caif_sktexit_module(void)
+{
+	sock_unregister(PF_CAIF);
+}
+module_init(caif_sktinit_module);
+module_exit(caif_sktexit_module);
diff --git a/net/caif/caif_usb.c b/net/caif/caif_usb.c
new file mode 100644
index 000000000..bf61ea4b8
--- /dev/null
+++ b/net/caif/caif_usb.c
@@ -0,0 +1,215 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * CAIF USB handler
+ * Copyright (C) ST-Ericsson AB 2011
+ * Author:	Sjur Brendeland
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
+
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/slab.h>
+#include <linux/mii.h>
+#include <linux/usb.h>
+#include <linux/usb/usbnet.h>
+#include <linux/etherdevice.h>
+#include <net/netns/generic.h>
+#include <net/caif/caif_dev.h>
+#include <net/caif/caif_layer.h>
+#include <net/caif/cfpkt.h>
+#include <net/caif/cfcnfg.h>
+
+MODULE_LICENSE("GPL");
+
+#define CFUSB_PAD_DESCR_SZ 1	/* Alignment descriptor length */
+#define CFUSB_ALIGNMENT 4	/* Number of bytes to align. */
+#define CFUSB_MAX_HEADLEN (CFUSB_PAD_DESCR_SZ + CFUSB_ALIGNMENT-1)
+#define STE_USB_VID 0x04cc	/* USB Product ID for ST-Ericsson */
+#define STE_USB_PID_CAIF 0x230f	/* Product id for CAIF Modems */
+
+struct cfusbl {
+	struct cflayer layer;
+	u8 tx_eth_hdr[ETH_HLEN];
+};
+
+static bool pack_added;
+
+static int cfusbl_receive(struct cflayer *layr, struct cfpkt *pkt)
+{
+	u8 hpad;
+
+	/* Remove padding. */
+	cfpkt_extr_head(pkt, &hpad, 1);
+	cfpkt_extr_head(pkt, NULL, hpad);
+	return layr->up->receive(layr->up, pkt);
+}
+
+static int cfusbl_transmit(struct cflayer *layr, struct cfpkt *pkt)
+{
+	struct caif_payload_info *info;
+	u8 hpad;
+	u8 zeros[CFUSB_ALIGNMENT];
+	struct sk_buff *skb;
+	struct cfusbl *usbl = container_of(layr, struct cfusbl, layer);
+
+	skb = cfpkt_tonative(pkt);
+
+	skb_reset_network_header(skb);
+	skb->protocol = htons(ETH_P_IP);
+
+	info = cfpkt_info(pkt);
+	hpad = (info->hdr_len + CFUSB_PAD_DESCR_SZ) & (CFUSB_ALIGNMENT - 1);
+
+	if (skb_headroom(skb) < ETH_HLEN + CFUSB_PAD_DESCR_SZ + hpad) {
+		pr_warn("Headroom too small\n");
+		kfree_skb(skb);
+		return -EIO;
+	}
+	memset(zeros, 0, hpad);
+
+	cfpkt_add_head(pkt, zeros, hpad);
+	cfpkt_add_head(pkt, &hpad, 1);
+	cfpkt_add_head(pkt, usbl->tx_eth_hdr, sizeof(usbl->tx_eth_hdr));
+	return layr->dn->transmit(layr->dn, pkt);
+}
+
+static void cfusbl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
+			   int phyid)
+{
+	if (layr->up && layr->up->ctrlcmd)
+		layr->up->ctrlcmd(layr->up, ctrl, layr->id);
+}
+
+static struct cflayer *cfusbl_create(int phyid, const u8 ethaddr[ETH_ALEN],
+				      u8 braddr[ETH_ALEN])
+{
+	struct cfusbl *this = kmalloc(sizeof(struct cfusbl), GFP_ATOMIC);
+
+	if (!this)
+		return NULL;
+
+	caif_assert(offsetof(struct cfusbl, layer) == 0);
+
+	memset(&this->layer, 0, sizeof(this->layer));
+	this->layer.receive = cfusbl_receive;
+	this->layer.transmit = cfusbl_transmit;
+	this->layer.ctrlcmd = cfusbl_ctrlcmd;
+	snprintf(this->layer.name, CAIF_LAYER_NAME_SZ, "usb%d", phyid);
+	this->layer.id = phyid;
+
+	/*
+	 * Construct TX ethernet header:
+	 *	0-5	destination address
+	 *	5-11	source address
+	 *	12-13	protocol type
+	 */
+	ether_addr_copy(&this->tx_eth_hdr[ETH_ALEN], braddr);
+	ether_addr_copy(&this->tx_eth_hdr[ETH_ALEN], ethaddr);
+	this->tx_eth_hdr[12] = cpu_to_be16(ETH_P_802_EX1) & 0xff;
+	this->tx_eth_hdr[13] = (cpu_to_be16(ETH_P_802_EX1) >> 8) & 0xff;
+	pr_debug("caif ethernet TX-header dst:%pM src:%pM type:%02x%02x\n",
+			this->tx_eth_hdr, this->tx_eth_hdr + ETH_ALEN,
+			this->tx_eth_hdr[12], this->tx_eth_hdr[13]);
+
+	return (struct cflayer *) this;
+}
+
+static void cfusbl_release(struct cflayer *layer)
+{
+	kfree(layer);
+}
+
+static struct packet_type caif_usb_type __read_mostly = {
+	.type = cpu_to_be16(ETH_P_802_EX1),
+};
+
+static int cfusbl_device_notify(struct notifier_block *me, unsigned long what,
+				void *ptr)
+{
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+	struct caif_dev_common common;
+	struct cflayer *layer, *link_support;
+	struct usbnet *usbnet;
+	struct usb_device *usbdev;
+	int res;
+
+	if (what == NETDEV_UNREGISTER && dev->reg_state >= NETREG_UNREGISTERED)
+		return 0;
+
+	/* Check whether we have a NCM device, and find its VID/PID. */
+	if (!(dev->dev.parent && dev->dev.parent->driver &&
+	      strcmp(dev->dev.parent->driver->name, "cdc_ncm") == 0))
+		return 0;
+
+	usbnet = netdev_priv(dev);
+	usbdev = usbnet->udev;
+
+	pr_debug("USB CDC NCM device VID:0x%4x PID:0x%4x\n",
+		le16_to_cpu(usbdev->descriptor.idVendor),
+		le16_to_cpu(usbdev->descriptor.idProduct));
+
+	/* Check for VID/PID that supports CAIF */
+	if (!(le16_to_cpu(usbdev->descriptor.idVendor) == STE_USB_VID &&
+		le16_to_cpu(usbdev->descriptor.idProduct) == STE_USB_PID_CAIF))
+		return 0;
+
+	if (what == NETDEV_UNREGISTER)
+		module_put(THIS_MODULE);
+
+	if (what != NETDEV_REGISTER)
+		return 0;
+
+	__module_get(THIS_MODULE);
+
+	memset(&common, 0, sizeof(common));
+	common.use_frag = false;
+	common.use_fcs = false;
+	common.use_stx = false;
+	common.link_select = CAIF_LINK_HIGH_BANDW;
+	common.flowctrl = NULL;
+
+	link_support = cfusbl_create(dev->ifindex, dev->dev_addr,
+					dev->broadcast);
+
+	if (!link_support)
+		return -ENOMEM;
+
+	if (dev->num_tx_queues > 1)
+		pr_warn("USB device uses more than one tx queue\n");
+
+	res = caif_enroll_dev(dev, &common, link_support, CFUSB_MAX_HEADLEN,
+			&layer, &caif_usb_type.func);
+	if (res)
+		goto err;
+
+	if (!pack_added)
+		dev_add_pack(&caif_usb_type);
+	pack_added = true;
+
+	strscpy(layer->name, dev->name, sizeof(layer->name));
+
+	return 0;
+err:
+	cfusbl_release(link_support);
+	return res;
+}
+
+static struct notifier_block caif_device_notifier = {
+	.notifier_call = cfusbl_device_notify,
+	.priority = 0,
+};
+
+static int __init cfusbl_init(void)
+{
+	return register_netdevice_notifier(&caif_device_notifier);
+}
+
+static void __exit cfusbl_exit(void)
+{
+	unregister_netdevice_notifier(&caif_device_notifier);
+	dev_remove_pack(&caif_usb_type);
+}
+
+module_init(cfusbl_init);
+module_exit(cfusbl_exit);
diff --git a/net/caif/cfcnfg.c b/net/caif/cfcnfg.c
new file mode 100644
index 000000000..52509e185
--- /dev/null
+++ b/net/caif/cfcnfg.c
@@ -0,0 +1,612 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) ST-Ericsson AB 2010
+ * Author:	Sjur Brendeland
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
+
+#include <linux/kernel.h>
+#include <linux/stddef.h>
+#include <linux/slab.h>
+#include <linux/netdevice.h>
+#include <linux/module.h>
+#include <net/caif/caif_layer.h>
+#include <net/caif/cfpkt.h>
+#include <net/caif/cfcnfg.h>
+#include <net/caif/cfctrl.h>
+#include <net/caif/cfmuxl.h>
+#include <net/caif/cffrml.h>
+#include <net/caif/cfserl.h>
+#include <net/caif/cfsrvl.h>
+#include <net/caif/caif_dev.h>
+
+#define container_obj(layr) container_of(layr, struct cfcnfg, layer)
+
+/* Information about CAIF physical interfaces held by Config Module in order
+ * to manage physical interfaces
+ */
+struct cfcnfg_phyinfo {
+	struct list_head node;
+	bool up;
+
+	/* Pointer to the layer below the MUX (framing layer) */
+	struct cflayer *frm_layer;
+	/* Pointer to the lowest actual physical layer */
+	struct cflayer *phy_layer;
+	/* Unique identifier of the physical interface */
+	unsigned int id;
+	/* Preference of the physical in interface */
+	enum cfcnfg_phy_preference pref;
+
+	/* Information about the physical device */
+	struct dev_info dev_info;
+
+	/* Interface index */
+	int ifindex;
+
+	/* Protocol head room added for CAIF link layer */
+	int head_room;
+
+	/* Use Start of frame checksum */
+	bool use_fcs;
+};
+
+struct cfcnfg {
+	struct cflayer layer;
+	struct cflayer *ctrl;
+	struct cflayer *mux;
+	struct list_head phys;
+	struct mutex lock;
+};
+
+static void cfcnfg_linkup_rsp(struct cflayer *layer, u8 channel_id,
+			      enum cfctrl_srv serv, u8 phyid,
+			      struct cflayer *adapt_layer);
+static void cfcnfg_linkdestroy_rsp(struct cflayer *layer, u8 channel_id);
+static void cfcnfg_reject_rsp(struct cflayer *layer, u8 channel_id,
+			      struct cflayer *adapt_layer);
+static void cfctrl_resp_func(void);
+static void cfctrl_enum_resp(void);
+
+struct cfcnfg *cfcnfg_create(void)
+{
+	struct cfcnfg *this;
+	struct cfctrl_rsp *resp;
+
+	might_sleep();
+
+	/* Initiate this layer */
+	this = kzalloc(sizeof(struct cfcnfg), GFP_ATOMIC);
+	if (!this)
+		return NULL;
+	this->mux = cfmuxl_create();
+	if (!this->mux)
+		goto out_of_mem;
+	this->ctrl = cfctrl_create();
+	if (!this->ctrl)
+		goto out_of_mem;
+	/* Initiate response functions */
+	resp = cfctrl_get_respfuncs(this->ctrl);
+	resp->enum_rsp = cfctrl_enum_resp;
+	resp->linkerror_ind = cfctrl_resp_func;
+	resp->linkdestroy_rsp = cfcnfg_linkdestroy_rsp;
+	resp->sleep_rsp = cfctrl_resp_func;
+	resp->wake_rsp = cfctrl_resp_func;
+	resp->restart_rsp = cfctrl_resp_func;
+	resp->radioset_rsp = cfctrl_resp_func;
+	resp->linksetup_rsp = cfcnfg_linkup_rsp;
+	resp->reject_rsp = cfcnfg_reject_rsp;
+	INIT_LIST_HEAD(&this->phys);
+
+	cfmuxl_set_uplayer(this->mux, this->ctrl, 0);
+	layer_set_dn(this->ctrl, this->mux);
+	layer_set_up(this->ctrl, this);
+	mutex_init(&this->lock);
+
+	return this;
+out_of_mem:
+	synchronize_rcu();
+
+	kfree(this->mux);
+	kfree(this->ctrl);
+	kfree(this);
+	return NULL;
+}
+
+void cfcnfg_remove(struct cfcnfg *cfg)
+{
+	might_sleep();
+	if (cfg) {
+		synchronize_rcu();
+
+		kfree(cfg->mux);
+		cfctrl_remove(cfg->ctrl);
+		kfree(cfg);
+	}
+}
+
+static void cfctrl_resp_func(void)
+{
+}
+
+static struct cfcnfg_phyinfo *cfcnfg_get_phyinfo_rcu(struct cfcnfg *cnfg,
+						     u8 phyid)
+{
+	struct cfcnfg_phyinfo *phy;
+
+	list_for_each_entry_rcu(phy, &cnfg->phys, node)
+		if (phy->id == phyid)
+			return phy;
+	return NULL;
+}
+
+static void cfctrl_enum_resp(void)
+{
+}
+
+static struct dev_info *cfcnfg_get_phyid(struct cfcnfg *cnfg,
+				  enum cfcnfg_phy_preference phy_pref)
+{
+	/* Try to match with specified preference */
+	struct cfcnfg_phyinfo *phy;
+
+	list_for_each_entry_rcu(phy, &cnfg->phys, node) {
+		if (phy->up && phy->pref == phy_pref &&
+				phy->frm_layer != NULL)
+
+			return &phy->dev_info;
+	}
+
+	/* Otherwise just return something */
+	list_for_each_entry_rcu(phy, &cnfg->phys, node)
+		if (phy->up)
+			return &phy->dev_info;
+
+	return NULL;
+}
+
+static int cfcnfg_get_id_from_ifi(struct cfcnfg *cnfg, int ifi)
+{
+	struct cfcnfg_phyinfo *phy;
+
+	list_for_each_entry_rcu(phy, &cnfg->phys, node)
+		if (phy->ifindex == ifi && phy->up)
+			return phy->id;
+	return -ENODEV;
+}
+
+int caif_disconnect_client(struct net *net, struct cflayer *adap_layer)
+{
+	u8 channel_id;
+	struct cfcnfg *cfg = get_cfcnfg(net);
+
+	caif_assert(adap_layer != NULL);
+	cfctrl_cancel_req(cfg->ctrl, adap_layer);
+	channel_id = adap_layer->id;
+	if (channel_id != 0) {
+		struct cflayer *servl;
+		servl = cfmuxl_remove_uplayer(cfg->mux, channel_id);
+		cfctrl_linkdown_req(cfg->ctrl, channel_id, adap_layer);
+		if (servl != NULL)
+			layer_set_up(servl, NULL);
+	} else
+		pr_debug("nothing to disconnect\n");
+
+	/* Do RCU sync before initiating cleanup */
+	synchronize_rcu();
+	if (adap_layer->ctrlcmd != NULL)
+		adap_layer->ctrlcmd(adap_layer, CAIF_CTRLCMD_DEINIT_RSP, 0);
+	return 0;
+
+}
+EXPORT_SYMBOL(caif_disconnect_client);
+
+static void cfcnfg_linkdestroy_rsp(struct cflayer *layer, u8 channel_id)
+{
+}
+
+static const int protohead[CFCTRL_SRV_MASK] = {
+	[CFCTRL_SRV_VEI] = 4,
+	[CFCTRL_SRV_DATAGRAM] = 7,
+	[CFCTRL_SRV_UTIL] = 4,
+	[CFCTRL_SRV_RFM] = 3,
+	[CFCTRL_SRV_DBG] = 3,
+};
+
+
+static int caif_connect_req_to_link_param(struct cfcnfg *cnfg,
+					  struct caif_connect_request *s,
+					  struct cfctrl_link_param *l)
+{
+	struct dev_info *dev_info;
+	enum cfcnfg_phy_preference pref;
+	int res;
+
+	memset(l, 0, sizeof(*l));
+	/* In caif protocol low value is high priority */
+	l->priority = CAIF_PRIO_MAX - s->priority + 1;
+
+	if (s->ifindex != 0) {
+		res = cfcnfg_get_id_from_ifi(cnfg, s->ifindex);
+		if (res < 0)
+			return res;
+		l->phyid = res;
+	} else {
+		switch (s->link_selector) {
+		case CAIF_LINK_HIGH_BANDW:
+			pref = CFPHYPREF_HIGH_BW;
+			break;
+		case CAIF_LINK_LOW_LATENCY:
+			pref = CFPHYPREF_LOW_LAT;
+			break;
+		default:
+			return -EINVAL;
+		}
+		dev_info = cfcnfg_get_phyid(cnfg, pref);
+		if (dev_info == NULL)
+			return -ENODEV;
+		l->phyid = dev_info->id;
+	}
+	switch (s->protocol) {
+	case CAIFPROTO_AT:
+		l->linktype = CFCTRL_SRV_VEI;
+		l->endpoint = (s->sockaddr.u.at.type >> 2) & 0x3;
+		l->chtype = s->sockaddr.u.at.type & 0x3;
+		break;
+	case CAIFPROTO_DATAGRAM:
+		l->linktype = CFCTRL_SRV_DATAGRAM;
+		l->chtype = 0x00;
+		l->u.datagram.connid = s->sockaddr.u.dgm.connection_id;
+		break;
+	case CAIFPROTO_DATAGRAM_LOOP:
+		l->linktype = CFCTRL_SRV_DATAGRAM;
+		l->chtype = 0x03;
+		l->endpoint = 0x00;
+		l->u.datagram.connid = s->sockaddr.u.dgm.connection_id;
+		break;
+	case CAIFPROTO_RFM:
+		l->linktype = CFCTRL_SRV_RFM;
+		l->u.datagram.connid = s->sockaddr.u.rfm.connection_id;
+		strscpy(l->u.rfm.volume, s->sockaddr.u.rfm.volume,
+			sizeof(l->u.rfm.volume));
+		break;
+	case CAIFPROTO_UTIL:
+		l->linktype = CFCTRL_SRV_UTIL;
+		l->endpoint = 0x00;
+		l->chtype = 0x00;
+		strscpy(l->u.utility.name, s->sockaddr.u.util.service,
+			sizeof(l->u.utility.name));
+		caif_assert(sizeof(l->u.utility.name) > 10);
+		l->u.utility.paramlen = s->param.size;
+		if (l->u.utility.paramlen > sizeof(l->u.utility.params))
+			l->u.utility.paramlen = sizeof(l->u.utility.params);
+
+		memcpy(l->u.utility.params, s->param.data,
+		       l->u.utility.paramlen);
+
+		break;
+	case CAIFPROTO_DEBUG:
+		l->linktype = CFCTRL_SRV_DBG;
+		l->endpoint = s->sockaddr.u.dbg.service;
+		l->chtype = s->sockaddr.u.dbg.type;
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+int caif_connect_client(struct net *net, struct caif_connect_request *conn_req,
+			struct cflayer *adap_layer, int *ifindex,
+			int *proto_head, int *proto_tail)
+{
+	struct cflayer *frml;
+	struct cfcnfg_phyinfo *phy;
+	int err;
+	struct cfctrl_link_param param;
+	struct cfcnfg *cfg = get_cfcnfg(net);
+
+	rcu_read_lock();
+	err = caif_connect_req_to_link_param(cfg, conn_req, &param);
+	if (err)
+		goto unlock;
+
+	phy = cfcnfg_get_phyinfo_rcu(cfg, param.phyid);
+	if (!phy) {
+		err = -ENODEV;
+		goto unlock;
+	}
+	err = -EINVAL;
+
+	if (adap_layer == NULL) {
+		pr_err("adap_layer is zero\n");
+		goto unlock;
+	}
+	if (adap_layer->receive == NULL) {
+		pr_err("adap_layer->receive is NULL\n");
+		goto unlock;
+	}
+	if (adap_layer->ctrlcmd == NULL) {
+		pr_err("adap_layer->ctrlcmd == NULL\n");
+		goto unlock;
+	}
+
+	err = -ENODEV;
+	frml = phy->frm_layer;
+	if (frml == NULL) {
+		pr_err("Specified PHY type does not exist!\n");
+		goto unlock;
+	}
+	caif_assert(param.phyid == phy->id);
+	caif_assert(phy->frm_layer->id ==
+		     param.phyid);
+	caif_assert(phy->phy_layer->id ==
+		     param.phyid);
+
+	*ifindex = phy->ifindex;
+	*proto_tail = 2;
+	*proto_head = protohead[param.linktype] + phy->head_room;
+
+	rcu_read_unlock();
+
+	/* FIXME: ENUMERATE INITIALLY WHEN ACTIVATING PHYSICAL INTERFACE */
+	cfctrl_enum_req(cfg->ctrl, param.phyid);
+	return cfctrl_linkup_request(cfg->ctrl, &param, adap_layer);
+
+unlock:
+	rcu_read_unlock();
+	return err;
+}
+EXPORT_SYMBOL(caif_connect_client);
+
+static void cfcnfg_reject_rsp(struct cflayer *layer, u8 channel_id,
+			      struct cflayer *adapt_layer)
+{
+	if (adapt_layer != NULL && adapt_layer->ctrlcmd != NULL)
+		adapt_layer->ctrlcmd(adapt_layer,
+				     CAIF_CTRLCMD_INIT_FAIL_RSP, 0);
+}
+
+static void
+cfcnfg_linkup_rsp(struct cflayer *layer, u8 channel_id, enum cfctrl_srv serv,
+		  u8 phyid, struct cflayer *adapt_layer)
+{
+	struct cfcnfg *cnfg = container_obj(layer);
+	struct cflayer *servicel = NULL;
+	struct cfcnfg_phyinfo *phyinfo;
+	struct net_device *netdev;
+
+	if (channel_id == 0) {
+		pr_warn("received channel_id zero\n");
+		if (adapt_layer != NULL && adapt_layer->ctrlcmd != NULL)
+			adapt_layer->ctrlcmd(adapt_layer,
+						CAIF_CTRLCMD_INIT_FAIL_RSP, 0);
+		return;
+	}
+
+	rcu_read_lock();
+
+	if (adapt_layer == NULL) {
+		pr_debug("link setup response but no client exist, send linkdown back\n");
+		cfctrl_linkdown_req(cnfg->ctrl, channel_id, NULL);
+		goto unlock;
+	}
+
+	caif_assert(cnfg != NULL);
+	caif_assert(phyid != 0);
+
+	phyinfo = cfcnfg_get_phyinfo_rcu(cnfg, phyid);
+	if (phyinfo == NULL) {
+		pr_err("ERROR: Link Layer Device disappeared while connecting\n");
+		goto unlock;
+	}
+
+	caif_assert(phyinfo != NULL);
+	caif_assert(phyinfo->id == phyid);
+	caif_assert(phyinfo->phy_layer != NULL);
+	caif_assert(phyinfo->phy_layer->id == phyid);
+
+	adapt_layer->id = channel_id;
+
+	switch (serv) {
+	case CFCTRL_SRV_VEI:
+		servicel = cfvei_create(channel_id, &phyinfo->dev_info);
+		break;
+	case CFCTRL_SRV_DATAGRAM:
+		servicel = cfdgml_create(channel_id,
+					&phyinfo->dev_info);
+		break;
+	case CFCTRL_SRV_RFM:
+		netdev = phyinfo->dev_info.dev;
+		servicel = cfrfml_create(channel_id, &phyinfo->dev_info,
+						netdev->mtu);
+		break;
+	case CFCTRL_SRV_UTIL:
+		servicel = cfutill_create(channel_id, &phyinfo->dev_info);
+		break;
+	case CFCTRL_SRV_VIDEO:
+		servicel = cfvidl_create(channel_id, &phyinfo->dev_info);
+		break;
+	case CFCTRL_SRV_DBG:
+		servicel = cfdbgl_create(channel_id, &phyinfo->dev_info);
+		break;
+	default:
+		pr_err("Protocol error. Link setup response - unknown channel type\n");
+		goto unlock;
+	}
+	if (!servicel)
+		goto unlock;
+	layer_set_dn(servicel, cnfg->mux);
+	cfmuxl_set_uplayer(cnfg->mux, servicel, channel_id);
+	layer_set_up(servicel, adapt_layer);
+	layer_set_dn(adapt_layer, servicel);
+
+	rcu_read_unlock();
+
+	servicel->ctrlcmd(servicel, CAIF_CTRLCMD_INIT_RSP, 0);
+	return;
+unlock:
+	rcu_read_unlock();
+}
+
+int
+cfcnfg_add_phy_layer(struct cfcnfg *cnfg,
+		     struct net_device *dev, struct cflayer *phy_layer,
+		     enum cfcnfg_phy_preference pref,
+		     struct cflayer *link_support,
+		     bool fcs, int head_room)
+{
+	struct cflayer *frml;
+	struct cfcnfg_phyinfo *phyinfo = NULL;
+	int i, res = 0;
+	u8 phyid;
+
+	mutex_lock(&cnfg->lock);
+
+	/* CAIF protocol allow maximum 6 link-layers */
+	for (i = 0; i < 7; i++) {
+		phyid = (dev->ifindex + i) & 0x7;
+		if (phyid == 0)
+			continue;
+		if (cfcnfg_get_phyinfo_rcu(cnfg, phyid) == NULL)
+			goto got_phyid;
+	}
+	pr_warn("Too many CAIF Link Layers (max 6)\n");
+	res = -EEXIST;
+	goto out;
+
+got_phyid:
+	phyinfo = kzalloc(sizeof(struct cfcnfg_phyinfo), GFP_ATOMIC);
+	if (!phyinfo) {
+		res = -ENOMEM;
+		goto out;
+	}
+
+	phy_layer->id = phyid;
+	phyinfo->pref = pref;
+	phyinfo->id = phyid;
+	phyinfo->dev_info.id = phyid;
+	phyinfo->dev_info.dev = dev;
+	phyinfo->phy_layer = phy_layer;
+	phyinfo->ifindex = dev->ifindex;
+	phyinfo->head_room = head_room;
+	phyinfo->use_fcs = fcs;
+
+	frml = cffrml_create(phyid, fcs);
+
+	if (!frml) {
+		res = -ENOMEM;
+		goto out_err;
+	}
+	phyinfo->frm_layer = frml;
+	layer_set_up(frml, cnfg->mux);
+
+	if (link_support != NULL) {
+		link_support->id = phyid;
+		layer_set_dn(frml, link_support);
+		layer_set_up(link_support, frml);
+		layer_set_dn(link_support, phy_layer);
+		layer_set_up(phy_layer, link_support);
+	} else {
+		layer_set_dn(frml, phy_layer);
+		layer_set_up(phy_layer, frml);
+	}
+
+	list_add_rcu(&phyinfo->node, &cnfg->phys);
+out:
+	mutex_unlock(&cnfg->lock);
+	return res;
+
+out_err:
+	kfree(phyinfo);
+	mutex_unlock(&cnfg->lock);
+	return res;
+}
+EXPORT_SYMBOL(cfcnfg_add_phy_layer);
+
+int cfcnfg_set_phy_state(struct cfcnfg *cnfg, struct cflayer *phy_layer,
+			 bool up)
+{
+	struct cfcnfg_phyinfo *phyinfo;
+
+	rcu_read_lock();
+	phyinfo = cfcnfg_get_phyinfo_rcu(cnfg, phy_layer->id);
+	if (phyinfo == NULL) {
+		rcu_read_unlock();
+		return -ENODEV;
+	}
+
+	if (phyinfo->up == up) {
+		rcu_read_unlock();
+		return 0;
+	}
+	phyinfo->up = up;
+
+	if (up) {
+		cffrml_hold(phyinfo->frm_layer);
+		cfmuxl_set_dnlayer(cnfg->mux, phyinfo->frm_layer,
+					phy_layer->id);
+	} else {
+		cfmuxl_remove_dnlayer(cnfg->mux, phy_layer->id);
+		cffrml_put(phyinfo->frm_layer);
+	}
+
+	rcu_read_unlock();
+	return 0;
+}
+EXPORT_SYMBOL(cfcnfg_set_phy_state);
+
+int cfcnfg_del_phy_layer(struct cfcnfg *cnfg, struct cflayer *phy_layer)
+{
+	struct cflayer *frml, *frml_dn;
+	u16 phyid;
+	struct cfcnfg_phyinfo *phyinfo;
+
+	might_sleep();
+
+	mutex_lock(&cnfg->lock);
+
+	phyid = phy_layer->id;
+	phyinfo = cfcnfg_get_phyinfo_rcu(cnfg, phyid);
+
+	if (phyinfo == NULL) {
+		mutex_unlock(&cnfg->lock);
+		return 0;
+	}
+	caif_assert(phyid == phyinfo->id);
+	caif_assert(phy_layer == phyinfo->phy_layer);
+	caif_assert(phy_layer->id == phyid);
+	caif_assert(phyinfo->frm_layer->id == phyid);
+
+	list_del_rcu(&phyinfo->node);
+	synchronize_rcu();
+
+	/* Fail if reference count is not zero */
+	if (cffrml_refcnt_read(phyinfo->frm_layer) != 0) {
+		pr_info("Wait for device inuse\n");
+		list_add_rcu(&phyinfo->node, &cnfg->phys);
+		mutex_unlock(&cnfg->lock);
+		return -EAGAIN;
+	}
+
+	frml = phyinfo->frm_layer;
+	frml_dn = frml->dn;
+	cffrml_set_uplayer(frml, NULL);
+	cffrml_set_dnlayer(frml, NULL);
+	if (phy_layer != frml_dn) {
+		layer_set_up(frml_dn, NULL);
+		layer_set_dn(frml_dn, NULL);
+	}
+	layer_set_up(phy_layer, NULL);
+
+	if (phyinfo->phy_layer != frml_dn)
+		kfree(frml_dn);
+
+	cffrml_free(frml);
+	kfree(phyinfo);
+	mutex_unlock(&cnfg->lock);
+
+	return 0;
+}
+EXPORT_SYMBOL(cfcnfg_del_phy_layer);
diff --git a/net/caif/cfctrl.c b/net/caif/cfctrl.c
new file mode 100644
index 000000000..8480684f2
--- /dev/null
+++ b/net/caif/cfctrl.c
@@ -0,0 +1,639 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) ST-Ericsson AB 2010
+ * Author:	Sjur Brendeland
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
+
+#include <linux/stddef.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/pkt_sched.h>
+#include <net/caif/caif_layer.h>
+#include <net/caif/cfpkt.h>
+#include <net/caif/cfctrl.h>
+
+#define container_obj(layr) container_of(layr, struct cfctrl, serv.layer)
+#define UTILITY_NAME_LENGTH 16
+#define CFPKT_CTRL_PKT_LEN 20
+
+#ifdef CAIF_NO_LOOP
+static int handle_loop(struct cfctrl *ctrl,
+		       int cmd, struct cfpkt *pkt){
+	return -1;
+}
+#else
+static int handle_loop(struct cfctrl *ctrl,
+		       int cmd, struct cfpkt *pkt);
+#endif
+static int cfctrl_recv(struct cflayer *layr, struct cfpkt *pkt);
+static void cfctrl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
+			   int phyid);
+
+
+struct cflayer *cfctrl_create(void)
+{
+	struct dev_info dev_info;
+	struct cfctrl *this =
+		kzalloc(sizeof(struct cfctrl), GFP_ATOMIC);
+	if (!this)
+		return NULL;
+	caif_assert(offsetof(struct cfctrl, serv.layer) == 0);
+	memset(&dev_info, 0, sizeof(dev_info));
+	dev_info.id = 0xff;
+	cfsrvl_init(&this->serv, 0, &dev_info, false);
+	atomic_set(&this->req_seq_no, 1);
+	atomic_set(&this->rsp_seq_no, 1);
+	this->serv.layer.receive = cfctrl_recv;
+	sprintf(this->serv.layer.name, "ctrl");
+	this->serv.layer.ctrlcmd = cfctrl_ctrlcmd;
+#ifndef CAIF_NO_LOOP
+	spin_lock_init(&this->loop_linkid_lock);
+	this->loop_linkid = 1;
+#endif
+	spin_lock_init(&this->info_list_lock);
+	INIT_LIST_HEAD(&this->list);
+	return &this->serv.layer;
+}
+
+void cfctrl_remove(struct cflayer *layer)
+{
+	struct cfctrl_request_info *p, *tmp;
+	struct cfctrl *ctrl = container_obj(layer);
+
+	spin_lock_bh(&ctrl->info_list_lock);
+	list_for_each_entry_safe(p, tmp, &ctrl->list, list) {
+		list_del(&p->list);
+		kfree(p);
+	}
+	spin_unlock_bh(&ctrl->info_list_lock);
+	kfree(layer);
+}
+
+static bool param_eq(const struct cfctrl_link_param *p1,
+		     const struct cfctrl_link_param *p2)
+{
+	bool eq =
+	    p1->linktype == p2->linktype &&
+	    p1->priority == p2->priority &&
+	    p1->phyid == p2->phyid &&
+	    p1->endpoint == p2->endpoint && p1->chtype == p2->chtype;
+
+	if (!eq)
+		return false;
+
+	switch (p1->linktype) {
+	case CFCTRL_SRV_VEI:
+		return true;
+	case CFCTRL_SRV_DATAGRAM:
+		return p1->u.datagram.connid == p2->u.datagram.connid;
+	case CFCTRL_SRV_RFM:
+		return
+		    p1->u.rfm.connid == p2->u.rfm.connid &&
+		    strcmp(p1->u.rfm.volume, p2->u.rfm.volume) == 0;
+	case CFCTRL_SRV_UTIL:
+		return
+		    p1->u.utility.fifosize_kb == p2->u.utility.fifosize_kb
+		    && p1->u.utility.fifosize_bufs ==
+		    p2->u.utility.fifosize_bufs
+		    && strcmp(p1->u.utility.name, p2->u.utility.name) == 0
+		    && p1->u.utility.paramlen == p2->u.utility.paramlen
+		    && memcmp(p1->u.utility.params, p2->u.utility.params,
+			      p1->u.utility.paramlen) == 0;
+
+	case CFCTRL_SRV_VIDEO:
+		return p1->u.video.connid == p2->u.video.connid;
+	case CFCTRL_SRV_DBG:
+		return true;
+	case CFCTRL_SRV_DECM:
+		return false;
+	default:
+		return false;
+	}
+	return false;
+}
+
+static bool cfctrl_req_eq(const struct cfctrl_request_info *r1,
+			  const struct cfctrl_request_info *r2)
+{
+	if (r1->cmd != r2->cmd)
+		return false;
+	if (r1->cmd == CFCTRL_CMD_LINK_SETUP)
+		return param_eq(&r1->param, &r2->param);
+	else
+		return r1->channel_id == r2->channel_id;
+}
+
+/* Insert request at the end */
+static void cfctrl_insert_req(struct cfctrl *ctrl,
+			      struct cfctrl_request_info *req)
+{
+	spin_lock_bh(&ctrl->info_list_lock);
+	atomic_inc(&ctrl->req_seq_no);
+	req->sequence_no = atomic_read(&ctrl->req_seq_no);
+	list_add_tail(&req->list, &ctrl->list);
+	spin_unlock_bh(&ctrl->info_list_lock);
+}
+
+/* Compare and remove request */
+static struct cfctrl_request_info *cfctrl_remove_req(struct cfctrl *ctrl,
+						struct cfctrl_request_info *req)
+{
+	struct cfctrl_request_info *p, *tmp, *first;
+
+	first = list_first_entry(&ctrl->list, struct cfctrl_request_info, list);
+
+	list_for_each_entry_safe(p, tmp, &ctrl->list, list) {
+		if (cfctrl_req_eq(req, p)) {
+			if (p != first)
+				pr_warn("Requests are not received in order\n");
+
+			atomic_set(&ctrl->rsp_seq_no,
+					 p->sequence_no);
+			list_del(&p->list);
+			goto out;
+		}
+	}
+	p = NULL;
+out:
+	return p;
+}
+
+struct cfctrl_rsp *cfctrl_get_respfuncs(struct cflayer *layer)
+{
+	struct cfctrl *this = container_obj(layer);
+	return &this->res;
+}
+
+static void init_info(struct caif_payload_info *info, struct cfctrl *cfctrl)
+{
+	info->hdr_len = 0;
+	info->channel_id = cfctrl->serv.layer.id;
+	info->dev_info = &cfctrl->serv.dev_info;
+}
+
+void cfctrl_enum_req(struct cflayer *layer, u8 physlinkid)
+{
+	struct cfpkt *pkt;
+	struct cfctrl *cfctrl = container_obj(layer);
+	struct cflayer *dn = cfctrl->serv.layer.dn;
+
+	if (!dn) {
+		pr_debug("not able to send enum request\n");
+		return;
+	}
+	pkt = cfpkt_create(CFPKT_CTRL_PKT_LEN);
+	if (!pkt)
+		return;
+	caif_assert(offsetof(struct cfctrl, serv.layer) == 0);
+	init_info(cfpkt_info(pkt), cfctrl);
+	cfpkt_info(pkt)->dev_info->id = physlinkid;
+	cfctrl->serv.dev_info.id = physlinkid;
+	cfpkt_addbdy(pkt, CFCTRL_CMD_ENUM);
+	cfpkt_addbdy(pkt, physlinkid);
+	cfpkt_set_prio(pkt, TC_PRIO_CONTROL);
+	dn->transmit(dn, pkt);
+}
+
+int cfctrl_linkup_request(struct cflayer *layer,
+			  struct cfctrl_link_param *param,
+			  struct cflayer *user_layer)
+{
+	struct cfctrl *cfctrl = container_obj(layer);
+	u32 tmp32;
+	u16 tmp16;
+	u8 tmp8;
+	struct cfctrl_request_info *req;
+	int ret;
+	char utility_name[16];
+	struct cfpkt *pkt;
+	struct cflayer *dn = cfctrl->serv.layer.dn;
+
+	if (!dn) {
+		pr_debug("not able to send linkup request\n");
+		return -ENODEV;
+	}
+
+	if (cfctrl_cancel_req(layer, user_layer) > 0) {
+		/* Slight Paranoia, check if already connecting */
+		pr_err("Duplicate connect request for same client\n");
+		WARN_ON(1);
+		return -EALREADY;
+	}
+
+	pkt = cfpkt_create(CFPKT_CTRL_PKT_LEN);
+	if (!pkt)
+		return -ENOMEM;
+	cfpkt_addbdy(pkt, CFCTRL_CMD_LINK_SETUP);
+	cfpkt_addbdy(pkt, (param->chtype << 4) | param->linktype);
+	cfpkt_addbdy(pkt, (param->priority << 3) | param->phyid);
+	cfpkt_addbdy(pkt, param->endpoint & 0x03);
+
+	switch (param->linktype) {
+	case CFCTRL_SRV_VEI:
+		break;
+	case CFCTRL_SRV_VIDEO:
+		cfpkt_addbdy(pkt, (u8) param->u.video.connid);
+		break;
+	case CFCTRL_SRV_DBG:
+		break;
+	case CFCTRL_SRV_DATAGRAM:
+		tmp32 = cpu_to_le32(param->u.datagram.connid);
+		cfpkt_add_body(pkt, &tmp32, 4);
+		break;
+	case CFCTRL_SRV_RFM:
+		/* Construct a frame, convert DatagramConnectionID to network
+		 * format long and copy it out...
+		 */
+		tmp32 = cpu_to_le32(param->u.rfm.connid);
+		cfpkt_add_body(pkt, &tmp32, 4);
+		/* Add volume name, including zero termination... */
+		cfpkt_add_body(pkt, param->u.rfm.volume,
+			       strlen(param->u.rfm.volume) + 1);
+		break;
+	case CFCTRL_SRV_UTIL:
+		tmp16 = cpu_to_le16(param->u.utility.fifosize_kb);
+		cfpkt_add_body(pkt, &tmp16, 2);
+		tmp16 = cpu_to_le16(param->u.utility.fifosize_bufs);
+		cfpkt_add_body(pkt, &tmp16, 2);
+		memset(utility_name, 0, sizeof(utility_name));
+		strscpy(utility_name, param->u.utility.name,
+			UTILITY_NAME_LENGTH);
+		cfpkt_add_body(pkt, utility_name, UTILITY_NAME_LENGTH);
+		tmp8 = param->u.utility.paramlen;
+		cfpkt_add_body(pkt, &tmp8, 1);
+		cfpkt_add_body(pkt, param->u.utility.params,
+			       param->u.utility.paramlen);
+		break;
+	default:
+		pr_warn("Request setup of bad link type = %d\n",
+			param->linktype);
+		cfpkt_destroy(pkt);
+		return -EINVAL;
+	}
+	req = kzalloc(sizeof(*req), GFP_KERNEL);
+	if (!req) {
+		cfpkt_destroy(pkt);
+		return -ENOMEM;
+	}
+
+	req->client_layer = user_layer;
+	req->cmd = CFCTRL_CMD_LINK_SETUP;
+	req->param = *param;
+	cfctrl_insert_req(cfctrl, req);
+	init_info(cfpkt_info(pkt), cfctrl);
+	/*
+	 * NOTE:Always send linkup and linkdown request on the same
+	 *	device as the payload. Otherwise old queued up payload
+	 *	might arrive with the newly allocated channel ID.
+	 */
+	cfpkt_info(pkt)->dev_info->id = param->phyid;
+	cfpkt_set_prio(pkt, TC_PRIO_CONTROL);
+	ret =
+	    dn->transmit(dn, pkt);
+	if (ret < 0) {
+		int count;
+
+		count = cfctrl_cancel_req(&cfctrl->serv.layer,
+						user_layer);
+		if (count != 1) {
+			pr_err("Could not remove request (%d)", count);
+			return -ENODEV;
+		}
+	}
+	return 0;
+}
+
+int cfctrl_linkdown_req(struct cflayer *layer, u8 channelid,
+			struct cflayer *client)
+{
+	int ret;
+	struct cfpkt *pkt;
+	struct cfctrl *cfctrl = container_obj(layer);
+	struct cflayer *dn = cfctrl->serv.layer.dn;
+
+	if (!dn) {
+		pr_debug("not able to send link-down request\n");
+		return -ENODEV;
+	}
+	pkt = cfpkt_create(CFPKT_CTRL_PKT_LEN);
+	if (!pkt)
+		return -ENOMEM;
+	cfpkt_addbdy(pkt, CFCTRL_CMD_LINK_DESTROY);
+	cfpkt_addbdy(pkt, channelid);
+	init_info(cfpkt_info(pkt), cfctrl);
+	cfpkt_set_prio(pkt, TC_PRIO_CONTROL);
+	ret =
+	    dn->transmit(dn, pkt);
+#ifndef CAIF_NO_LOOP
+	cfctrl->loop_linkused[channelid] = 0;
+#endif
+	return ret;
+}
+
+int cfctrl_cancel_req(struct cflayer *layr, struct cflayer *adap_layer)
+{
+	struct cfctrl_request_info *p, *tmp;
+	struct cfctrl *ctrl = container_obj(layr);
+	int found = 0;
+	spin_lock_bh(&ctrl->info_list_lock);
+
+	list_for_each_entry_safe(p, tmp, &ctrl->list, list) {
+		if (p->client_layer == adap_layer) {
+			list_del(&p->list);
+			kfree(p);
+			found++;
+		}
+	}
+
+	spin_unlock_bh(&ctrl->info_list_lock);
+	return found;
+}
+
+static int cfctrl_recv(struct cflayer *layer, struct cfpkt *pkt)
+{
+	u8 cmdrsp;
+	u8 cmd;
+	int ret = -1;
+	u8 len;
+	u8 param[255];
+	u8 linkid = 0;
+	struct cfctrl *cfctrl = container_obj(layer);
+	struct cfctrl_request_info rsp, *req;
+
+
+	cmdrsp = cfpkt_extr_head_u8(pkt);
+	cmd = cmdrsp & CFCTRL_CMD_MASK;
+	if (cmd != CFCTRL_CMD_LINK_ERR
+	    && CFCTRL_RSP_BIT != (CFCTRL_RSP_BIT & cmdrsp)
+		&& CFCTRL_ERR_BIT != (CFCTRL_ERR_BIT & cmdrsp)) {
+		if (handle_loop(cfctrl, cmd, pkt) != 0)
+			cmdrsp |= CFCTRL_ERR_BIT;
+	}
+
+	switch (cmd) {
+	case CFCTRL_CMD_LINK_SETUP:
+		{
+			enum cfctrl_srv serv;
+			enum cfctrl_srv servtype;
+			u8 endpoint;
+			u8 physlinkid;
+			u8 prio;
+			u8 tmp;
+			u8 *cp;
+			int i;
+			struct cfctrl_link_param linkparam;
+			memset(&linkparam, 0, sizeof(linkparam));
+
+			tmp = cfpkt_extr_head_u8(pkt);
+
+			serv = tmp & CFCTRL_SRV_MASK;
+			linkparam.linktype = serv;
+
+			servtype = tmp >> 4;
+			linkparam.chtype = servtype;
+
+			tmp = cfpkt_extr_head_u8(pkt);
+			physlinkid = tmp & 0x07;
+			prio = tmp >> 3;
+
+			linkparam.priority = prio;
+			linkparam.phyid = physlinkid;
+			endpoint = cfpkt_extr_head_u8(pkt);
+			linkparam.endpoint = endpoint & 0x03;
+
+			switch (serv) {
+			case CFCTRL_SRV_VEI:
+			case CFCTRL_SRV_DBG:
+				if (CFCTRL_ERR_BIT & cmdrsp)
+					break;
+				/* Link ID */
+				linkid = cfpkt_extr_head_u8(pkt);
+				break;
+			case CFCTRL_SRV_VIDEO:
+				tmp = cfpkt_extr_head_u8(pkt);
+				linkparam.u.video.connid = tmp;
+				if (CFCTRL_ERR_BIT & cmdrsp)
+					break;
+				/* Link ID */
+				linkid = cfpkt_extr_head_u8(pkt);
+				break;
+
+			case CFCTRL_SRV_DATAGRAM:
+				linkparam.u.datagram.connid =
+				    cfpkt_extr_head_u32(pkt);
+				if (CFCTRL_ERR_BIT & cmdrsp)
+					break;
+				/* Link ID */
+				linkid = cfpkt_extr_head_u8(pkt);
+				break;
+			case CFCTRL_SRV_RFM:
+				/* Construct a frame, convert
+				 * DatagramConnectionID
+				 * to network format long and copy it out...
+				 */
+				linkparam.u.rfm.connid =
+				    cfpkt_extr_head_u32(pkt);
+				cp = (u8 *) linkparam.u.rfm.volume;
+				for (tmp = cfpkt_extr_head_u8(pkt);
+				     cfpkt_more(pkt) && tmp != '\0';
+				     tmp = cfpkt_extr_head_u8(pkt))
+					*cp++ = tmp;
+				*cp = '\0';
+
+				if (CFCTRL_ERR_BIT & cmdrsp)
+					break;
+				/* Link ID */
+				linkid = cfpkt_extr_head_u8(pkt);
+
+				break;
+			case CFCTRL_SRV_UTIL:
+				/* Construct a frame, convert
+				 * DatagramConnectionID
+				 * to network format long and copy it out...
+				 */
+				/* Fifosize KB */
+				linkparam.u.utility.fifosize_kb =
+				    cfpkt_extr_head_u16(pkt);
+				/* Fifosize bufs */
+				linkparam.u.utility.fifosize_bufs =
+				    cfpkt_extr_head_u16(pkt);
+				/* name */
+				cp = (u8 *) linkparam.u.utility.name;
+				caif_assert(sizeof(linkparam.u.utility.name)
+					     >= UTILITY_NAME_LENGTH);
+				for (i = 0;
+				     i < UTILITY_NAME_LENGTH
+				     && cfpkt_more(pkt); i++) {
+					tmp = cfpkt_extr_head_u8(pkt);
+					*cp++ = tmp;
+				}
+				/* Length */
+				len = cfpkt_extr_head_u8(pkt);
+				linkparam.u.utility.paramlen = len;
+				/* Param Data */
+				cp = linkparam.u.utility.params;
+				while (cfpkt_more(pkt) && len--) {
+					tmp = cfpkt_extr_head_u8(pkt);
+					*cp++ = tmp;
+				}
+				if (CFCTRL_ERR_BIT & cmdrsp)
+					break;
+				/* Link ID */
+				linkid = cfpkt_extr_head_u8(pkt);
+				/* Length */
+				len = cfpkt_extr_head_u8(pkt);
+				/* Param Data */
+				cfpkt_extr_head(pkt, &param, len);
+				break;
+			default:
+				pr_warn("Request setup, invalid type (%d)\n",
+					serv);
+				goto error;
+			}
+
+			rsp.cmd = cmd;
+			rsp.param = linkparam;
+			spin_lock_bh(&cfctrl->info_list_lock);
+			req = cfctrl_remove_req(cfctrl, &rsp);
+
+			if (CFCTRL_ERR_BIT == (CFCTRL_ERR_BIT & cmdrsp) ||
+				cfpkt_erroneous(pkt)) {
+				pr_err("Invalid O/E bit or parse error "
+						"on CAIF control channel\n");
+				cfctrl->res.reject_rsp(cfctrl->serv.layer.up,
+						       0,
+						       req ? req->client_layer
+						       : NULL);
+			} else {
+				cfctrl->res.linksetup_rsp(cfctrl->serv.
+							  layer.up, linkid,
+							  serv, physlinkid,
+							  req ? req->
+							  client_layer : NULL);
+			}
+
+			kfree(req);
+
+			spin_unlock_bh(&cfctrl->info_list_lock);
+		}
+		break;
+	case CFCTRL_CMD_LINK_DESTROY:
+		linkid = cfpkt_extr_head_u8(pkt);
+		cfctrl->res.linkdestroy_rsp(cfctrl->serv.layer.up, linkid);
+		break;
+	case CFCTRL_CMD_LINK_ERR:
+		pr_err("Frame Error Indication received\n");
+		cfctrl->res.linkerror_ind();
+		break;
+	case CFCTRL_CMD_ENUM:
+		cfctrl->res.enum_rsp();
+		break;
+	case CFCTRL_CMD_SLEEP:
+		cfctrl->res.sleep_rsp();
+		break;
+	case CFCTRL_CMD_WAKE:
+		cfctrl->res.wake_rsp();
+		break;
+	case CFCTRL_CMD_LINK_RECONF:
+		cfctrl->res.restart_rsp();
+		break;
+	case CFCTRL_CMD_RADIO_SET:
+		cfctrl->res.radioset_rsp();
+		break;
+	default:
+		pr_err("Unrecognized Control Frame\n");
+		goto error;
+	}
+	ret = 0;
+error:
+	cfpkt_destroy(pkt);
+	return ret;
+}
+
+static void cfctrl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
+			   int phyid)
+{
+	struct cfctrl *this = container_obj(layr);
+	switch (ctrl) {
+	case _CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND:
+	case CAIF_CTRLCMD_FLOW_OFF_IND:
+		spin_lock_bh(&this->info_list_lock);
+		if (!list_empty(&this->list))
+			pr_debug("Received flow off in control layer\n");
+		spin_unlock_bh(&this->info_list_lock);
+		break;
+	case _CAIF_CTRLCMD_PHYIF_DOWN_IND: {
+		struct cfctrl_request_info *p, *tmp;
+
+		/* Find all connect request and report failure */
+		spin_lock_bh(&this->info_list_lock);
+		list_for_each_entry_safe(p, tmp, &this->list, list) {
+			if (p->param.phyid == phyid) {
+				list_del(&p->list);
+				p->client_layer->ctrlcmd(p->client_layer,
+						CAIF_CTRLCMD_INIT_FAIL_RSP,
+						phyid);
+				kfree(p);
+			}
+		}
+		spin_unlock_bh(&this->info_list_lock);
+		break;
+	}
+	default:
+		break;
+	}
+}
+
+#ifndef CAIF_NO_LOOP
+static int handle_loop(struct cfctrl *ctrl, int cmd, struct cfpkt *pkt)
+{
+	static int last_linkid;
+	static int dec;
+	u8 linkid, linktype, tmp;
+	switch (cmd) {
+	case CFCTRL_CMD_LINK_SETUP:
+		spin_lock_bh(&ctrl->loop_linkid_lock);
+		if (!dec) {
+			for (linkid = last_linkid + 1; linkid < 254; linkid++)
+				if (!ctrl->loop_linkused[linkid])
+					goto found;
+		}
+		dec = 1;
+		for (linkid = last_linkid - 1; linkid > 1; linkid--)
+			if (!ctrl->loop_linkused[linkid])
+				goto found;
+		spin_unlock_bh(&ctrl->loop_linkid_lock);
+		return -1;
+found:
+		if (linkid < 10)
+			dec = 0;
+
+		if (!ctrl->loop_linkused[linkid])
+			ctrl->loop_linkused[linkid] = 1;
+
+		last_linkid = linkid;
+
+		cfpkt_add_trail(pkt, &linkid, 1);
+		spin_unlock_bh(&ctrl->loop_linkid_lock);
+		cfpkt_peek_head(pkt, &linktype, 1);
+		if (linktype ==  CFCTRL_SRV_UTIL) {
+			tmp = 0x01;
+			cfpkt_add_trail(pkt, &tmp, 1);
+			cfpkt_add_trail(pkt, &tmp, 1);
+		}
+		break;
+
+	case CFCTRL_CMD_LINK_DESTROY:
+		spin_lock_bh(&ctrl->loop_linkid_lock);
+		cfpkt_peek_head(pkt, &linkid, 1);
+		ctrl->loop_linkused[linkid] = 0;
+		spin_unlock_bh(&ctrl->loop_linkid_lock);
+		break;
+	default:
+		break;
+	}
+	return 0;
+}
+#endif
diff --git a/net/caif/cfdbgl.c b/net/caif/cfdbgl.c
new file mode 100644
index 000000000..77f428428
--- /dev/null
+++ b/net/caif/cfdbgl.c
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) ST-Ericsson AB 2010
+ * Author:	Sjur Brendeland
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
+
+#include <linux/stddef.h>
+#include <linux/slab.h>
+#include <net/caif/caif_layer.h>
+#include <net/caif/cfsrvl.h>
+#include <net/caif/cfpkt.h>
+
+#define container_obj(layr) ((struct cfsrvl *) layr)
+
+static int cfdbgl_receive(struct cflayer *layr, struct cfpkt *pkt);
+static int cfdbgl_transmit(struct cflayer *layr, struct cfpkt *pkt);
+
+struct cflayer *cfdbgl_create(u8 channel_id, struct dev_info *dev_info)
+{
+	struct cfsrvl *dbg = kzalloc(sizeof(struct cfsrvl), GFP_ATOMIC);
+	if (!dbg)
+		return NULL;
+	caif_assert(offsetof(struct cfsrvl, layer) == 0);
+	cfsrvl_init(dbg, channel_id, dev_info, false);
+	dbg->layer.receive = cfdbgl_receive;
+	dbg->layer.transmit = cfdbgl_transmit;
+	snprintf(dbg->layer.name, CAIF_LAYER_NAME_SZ, "dbg%d", channel_id);
+	return &dbg->layer;
+}
+
+static int cfdbgl_receive(struct cflayer *layr, struct cfpkt *pkt)
+{
+	return layr->up->receive(layr->up, pkt);
+}
+
+static int cfdbgl_transmit(struct cflayer *layr, struct cfpkt *pkt)
+{
+	struct cfsrvl *service = container_obj(layr);
+	struct caif_payload_info *info;
+	int ret;
+
+	if (!cfsrvl_ready(service, &ret)) {
+		cfpkt_destroy(pkt);
+		return ret;
+	}
+
+	/* Add info for MUX-layer to route the packet out */
+	info = cfpkt_info(pkt);
+	info->channel_id = service->layer.id;
+	info->dev_info = &service->dev_info;
+
+	return layr->dn->transmit(layr->dn, pkt);
+}
diff --git a/net/caif/cfdgml.c b/net/caif/cfdgml.c
new file mode 100644
index 000000000..eb6f8ef47
--- /dev/null
+++ b/net/caif/cfdgml.c
@@ -0,0 +1,113 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) ST-Ericsson AB 2010
+ * Author:	Sjur Brendeland
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
+
+#include <linux/stddef.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <net/caif/caif_layer.h>
+#include <net/caif/cfsrvl.h>
+#include <net/caif/cfpkt.h>
+
+
+#define container_obj(layr) ((struct cfsrvl *) layr)
+
+#define DGM_CMD_BIT  0x80
+#define DGM_FLOW_OFF 0x81
+#define DGM_FLOW_ON  0x80
+#define DGM_MTU 1500
+
+static int cfdgml_receive(struct cflayer *layr, struct cfpkt *pkt);
+static int cfdgml_transmit(struct cflayer *layr, struct cfpkt *pkt);
+
+struct cflayer *cfdgml_create(u8 channel_id, struct dev_info *dev_info)
+{
+	struct cfsrvl *dgm = kzalloc(sizeof(struct cfsrvl), GFP_ATOMIC);
+	if (!dgm)
+		return NULL;
+	caif_assert(offsetof(struct cfsrvl, layer) == 0);
+	cfsrvl_init(dgm, channel_id, dev_info, true);
+	dgm->layer.receive = cfdgml_receive;
+	dgm->layer.transmit = cfdgml_transmit;
+	snprintf(dgm->layer.name, CAIF_LAYER_NAME_SZ, "dgm%d", channel_id);
+	return &dgm->layer;
+}
+
+static int cfdgml_receive(struct cflayer *layr, struct cfpkt *pkt)
+{
+	u8 cmd = -1;
+	u8 dgmhdr[3];
+	int ret;
+	caif_assert(layr->up != NULL);
+	caif_assert(layr->receive != NULL);
+	caif_assert(layr->ctrlcmd != NULL);
+
+	if (cfpkt_extr_head(pkt, &cmd, 1) < 0) {
+		pr_err("Packet is erroneous!\n");
+		cfpkt_destroy(pkt);
+		return -EPROTO;
+	}
+
+	if ((cmd & DGM_CMD_BIT) == 0) {
+		if (cfpkt_extr_head(pkt, &dgmhdr, 3) < 0) {
+			pr_err("Packet is erroneous!\n");
+			cfpkt_destroy(pkt);
+			return -EPROTO;
+		}
+		ret = layr->up->receive(layr->up, pkt);
+		return ret;
+	}
+
+	switch (cmd) {
+	case DGM_FLOW_OFF:	/* FLOW OFF */
+		layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_OFF_IND, 0);
+		cfpkt_destroy(pkt);
+		return 0;
+	case DGM_FLOW_ON:	/* FLOW ON */
+		layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_ON_IND, 0);
+		cfpkt_destroy(pkt);
+		return 0;
+	default:
+		cfpkt_destroy(pkt);
+		pr_info("Unknown datagram control %d (0x%x)\n", cmd, cmd);
+		return -EPROTO;
+	}
+}
+
+static int cfdgml_transmit(struct cflayer *layr, struct cfpkt *pkt)
+{
+	u8 packet_type;
+	u32 zero = 0;
+	struct caif_payload_info *info;
+	struct cfsrvl *service = container_obj(layr);
+	int ret;
+
+	if (!cfsrvl_ready(service, &ret)) {
+		cfpkt_destroy(pkt);
+		return ret;
+	}
+
+	/* STE Modem cannot handle more than 1500 bytes datagrams */
+	if (cfpkt_getlen(pkt) > DGM_MTU) {
+		cfpkt_destroy(pkt);
+		return -EMSGSIZE;
+	}
+
+	cfpkt_add_head(pkt, &zero, 3);
+	packet_type = 0x08; /* B9 set - UNCLASSIFIED */
+	cfpkt_add_head(pkt, &packet_type, 1);
+
+	/* Add info for MUX-layer to route the packet out. */
+	info = cfpkt_info(pkt);
+	info->channel_id = service->layer.id;
+	/* To optimize alignment, we add up the size of CAIF header
+	 * before payload.
+	 */
+	info->hdr_len = 4;
+	info->dev_info = &service->dev_info;
+	return layr->dn->transmit(layr->dn, pkt);
+}
diff --git a/net/caif/cffrml.c b/net/caif/cffrml.c
new file mode 100644
index 000000000..6651a8dc6
--- /dev/null
+++ b/net/caif/cffrml.c
@@ -0,0 +1,197 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * CAIF Framing Layer.
+ *
+ * Copyright (C) ST-Ericsson AB 2010
+ * Author:	Sjur Brendeland
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
+
+#include <linux/stddef.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/crc-ccitt.h>
+#include <linux/netdevice.h>
+#include <net/caif/caif_layer.h>
+#include <net/caif/cfpkt.h>
+#include <net/caif/cffrml.h>
+
+#define container_obj(layr) container_of(layr, struct cffrml, layer)
+
+struct cffrml {
+	struct cflayer layer;
+	bool dofcs;		/* !< FCS active */
+	int __percpu		*pcpu_refcnt;
+};
+
+static int cffrml_receive(struct cflayer *layr, struct cfpkt *pkt);
+static int cffrml_transmit(struct cflayer *layr, struct cfpkt *pkt);
+static void cffrml_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
+			   int phyid);
+
+static u32 cffrml_rcv_error;
+static u32 cffrml_rcv_checsum_error;
+struct cflayer *cffrml_create(u16 phyid, bool use_fcs)
+{
+	struct cffrml *this = kzalloc(sizeof(struct cffrml), GFP_ATOMIC);
+	if (!this)
+		return NULL;
+	this->pcpu_refcnt = alloc_percpu(int);
+	if (this->pcpu_refcnt == NULL) {
+		kfree(this);
+		return NULL;
+	}
+
+	caif_assert(offsetof(struct cffrml, layer) == 0);
+
+	this->layer.receive = cffrml_receive;
+	this->layer.transmit = cffrml_transmit;
+	this->layer.ctrlcmd = cffrml_ctrlcmd;
+	snprintf(this->layer.name, CAIF_LAYER_NAME_SZ, "frm%d", phyid);
+	this->dofcs = use_fcs;
+	this->layer.id = phyid;
+	return (struct cflayer *) this;
+}
+
+void cffrml_free(struct cflayer *layer)
+{
+	struct cffrml *this = container_obj(layer);
+	free_percpu(this->pcpu_refcnt);
+	kfree(layer);
+}
+
+void cffrml_set_uplayer(struct cflayer *this, struct cflayer *up)
+{
+	this->up = up;
+}
+
+void cffrml_set_dnlayer(struct cflayer *this, struct cflayer *dn)
+{
+	this->dn = dn;
+}
+
+static u16 cffrml_checksum(u16 chks, void *buf, u16 len)
+{
+	/* FIXME: FCS should be moved to glue in order to use OS-Specific
+	 * solutions
+	 */
+	return crc_ccitt(chks, buf, len);
+}
+
+static int cffrml_receive(struct cflayer *layr, struct cfpkt *pkt)
+{
+	u16 tmp;
+	u16 len;
+	u16 hdrchks;
+	int pktchks;
+	struct cffrml *this;
+	this = container_obj(layr);
+
+	cfpkt_extr_head(pkt, &tmp, 2);
+	len = le16_to_cpu(tmp);
+
+	/* Subtract for FCS on length if FCS is not used. */
+	if (!this->dofcs)
+		len -= 2;
+
+	if (cfpkt_setlen(pkt, len) < 0) {
+		++cffrml_rcv_error;
+		pr_err("Framing length error (%d)\n", len);
+		cfpkt_destroy(pkt);
+		return -EPROTO;
+	}
+	/*
+	 * Don't do extract if FCS is false, rather do setlen - then we don't
+	 * get a cache-miss.
+	 */
+	if (this->dofcs) {
+		cfpkt_extr_trail(pkt, &tmp, 2);
+		hdrchks = le16_to_cpu(tmp);
+		pktchks = cfpkt_iterate(pkt, cffrml_checksum, 0xffff);
+		if (pktchks != hdrchks) {
+			cfpkt_add_trail(pkt, &tmp, 2);
+			++cffrml_rcv_error;
+			++cffrml_rcv_checsum_error;
+			pr_info("Frame checksum error (0x%x != 0x%x)\n",
+				hdrchks, pktchks);
+			return -EILSEQ;
+		}
+	}
+	if (cfpkt_erroneous(pkt)) {
+		++cffrml_rcv_error;
+		pr_err("Packet is erroneous!\n");
+		cfpkt_destroy(pkt);
+		return -EPROTO;
+	}
+
+	if (layr->up == NULL) {
+		pr_err("Layr up is missing!\n");
+		cfpkt_destroy(pkt);
+		return -EINVAL;
+	}
+
+	return layr->up->receive(layr->up, pkt);
+}
+
+static int cffrml_transmit(struct cflayer *layr, struct cfpkt *pkt)
+{
+	u16 chks;
+	u16 len;
+	__le16 data;
+
+	struct cffrml *this = container_obj(layr);
+	if (this->dofcs) {
+		chks = cfpkt_iterate(pkt, cffrml_checksum, 0xffff);
+		data = cpu_to_le16(chks);
+		cfpkt_add_trail(pkt, &data, 2);
+	} else {
+		cfpkt_pad_trail(pkt, 2);
+	}
+	len = cfpkt_getlen(pkt);
+	data = cpu_to_le16(len);
+	cfpkt_add_head(pkt, &data, 2);
+	cfpkt_info(pkt)->hdr_len += 2;
+	if (cfpkt_erroneous(pkt)) {
+		pr_err("Packet is erroneous!\n");
+		cfpkt_destroy(pkt);
+		return -EPROTO;
+	}
+
+	if (layr->dn == NULL) {
+		cfpkt_destroy(pkt);
+		return -ENODEV;
+
+	}
+	return layr->dn->transmit(layr->dn, pkt);
+}
+
+static void cffrml_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
+			   int phyid)
+{
+	if (layr->up && layr->up->ctrlcmd)
+		layr->up->ctrlcmd(layr->up, ctrl, layr->id);
+}
+
+void cffrml_put(struct cflayer *layr)
+{
+	struct cffrml *this = container_obj(layr);
+	if (layr != NULL && this->pcpu_refcnt != NULL)
+		this_cpu_dec(*this->pcpu_refcnt);
+}
+
+void cffrml_hold(struct cflayer *layr)
+{
+	struct cffrml *this = container_obj(layr);
+	if (layr != NULL && this->pcpu_refcnt != NULL)
+		this_cpu_inc(*this->pcpu_refcnt);
+}
+
+int cffrml_refcnt_read(struct cflayer *layr)
+{
+	int i, refcnt = 0;
+	struct cffrml *this = container_obj(layr);
+	for_each_possible_cpu(i)
+		refcnt += *per_cpu_ptr(this->pcpu_refcnt, i);
+	return refcnt;
+}
diff --git a/net/caif/cfmuxl.c b/net/caif/cfmuxl.c
new file mode 100644
index 000000000..4172b0d0d
--- /dev/null
+++ b/net/caif/cfmuxl.c
@@ -0,0 +1,267 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) ST-Ericsson AB 2010
+ * Author:	Sjur Brendeland
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
+
+#include <linux/stddef.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/rculist.h>
+#include <net/caif/cfpkt.h>
+#include <net/caif/cfmuxl.h>
+#include <net/caif/cfsrvl.h>
+#include <net/caif/cffrml.h>
+
+#define container_obj(layr) container_of(layr, struct cfmuxl, layer)
+
+#define CAIF_CTRL_CHANNEL 0
+#define UP_CACHE_SIZE 8
+#define DN_CACHE_SIZE 8
+
+struct cfmuxl {
+	struct cflayer layer;
+	struct list_head srvl_list;
+	struct list_head frml_list;
+	struct cflayer *up_cache[UP_CACHE_SIZE];
+	struct cflayer *dn_cache[DN_CACHE_SIZE];
+	/*
+	 * Set when inserting or removing downwards layers.
+	 */
+	spinlock_t transmit_lock;
+
+	/*
+	 * Set when inserting or removing upwards layers.
+	 */
+	spinlock_t receive_lock;
+
+};
+
+static int cfmuxl_receive(struct cflayer *layr, struct cfpkt *pkt);
+static int cfmuxl_transmit(struct cflayer *layr, struct cfpkt *pkt);
+static void cfmuxl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
+			   int phyid);
+static struct cflayer *get_up(struct cfmuxl *muxl, u16 id);
+
+struct cflayer *cfmuxl_create(void)
+{
+	struct cfmuxl *this = kzalloc(sizeof(struct cfmuxl), GFP_ATOMIC);
+
+	if (!this)
+		return NULL;
+	this->layer.receive = cfmuxl_receive;
+	this->layer.transmit = cfmuxl_transmit;
+	this->layer.ctrlcmd = cfmuxl_ctrlcmd;
+	INIT_LIST_HEAD(&this->srvl_list);
+	INIT_LIST_HEAD(&this->frml_list);
+	spin_lock_init(&this->transmit_lock);
+	spin_lock_init(&this->receive_lock);
+	snprintf(this->layer.name, CAIF_LAYER_NAME_SZ, "mux");
+	return &this->layer;
+}
+
+int cfmuxl_set_dnlayer(struct cflayer *layr, struct cflayer *dn, u8 phyid)
+{
+	struct cfmuxl *muxl = (struct cfmuxl *) layr;
+
+	spin_lock_bh(&muxl->transmit_lock);
+	list_add_rcu(&dn->node, &muxl->frml_list);
+	spin_unlock_bh(&muxl->transmit_lock);
+	return 0;
+}
+
+static struct cflayer *get_from_id(struct list_head *list, u16 id)
+{
+	struct cflayer *lyr;
+	list_for_each_entry_rcu(lyr, list, node) {
+		if (lyr->id == id)
+			return lyr;
+	}
+
+	return NULL;
+}
+
+int cfmuxl_set_uplayer(struct cflayer *layr, struct cflayer *up, u8 linkid)
+{
+	struct cfmuxl *muxl = container_obj(layr);
+	struct cflayer *old;
+
+	spin_lock_bh(&muxl->receive_lock);
+
+	/* Two entries with same id is wrong, so remove old layer from mux */
+	old = get_from_id(&muxl->srvl_list, linkid);
+	if (old != NULL)
+		list_del_rcu(&old->node);
+
+	list_add_rcu(&up->node, &muxl->srvl_list);
+	spin_unlock_bh(&muxl->receive_lock);
+
+	return 0;
+}
+
+struct cflayer *cfmuxl_remove_dnlayer(struct cflayer *layr, u8 phyid)
+{
+	struct cfmuxl *muxl = container_obj(layr);
+	struct cflayer *dn;
+	int idx = phyid % DN_CACHE_SIZE;
+
+	spin_lock_bh(&muxl->transmit_lock);
+	RCU_INIT_POINTER(muxl->dn_cache[idx], NULL);
+	dn = get_from_id(&muxl->frml_list, phyid);
+	if (dn == NULL)
+		goto out;
+
+	list_del_rcu(&dn->node);
+	caif_assert(dn != NULL);
+out:
+	spin_unlock_bh(&muxl->transmit_lock);
+	return dn;
+}
+
+static struct cflayer *get_up(struct cfmuxl *muxl, u16 id)
+{
+	struct cflayer *up;
+	int idx = id % UP_CACHE_SIZE;
+	up = rcu_dereference(muxl->up_cache[idx]);
+	if (up == NULL || up->id != id) {
+		spin_lock_bh(&muxl->receive_lock);
+		up = get_from_id(&muxl->srvl_list, id);
+		rcu_assign_pointer(muxl->up_cache[idx], up);
+		spin_unlock_bh(&muxl->receive_lock);
+	}
+	return up;
+}
+
+static struct cflayer *get_dn(struct cfmuxl *muxl, struct dev_info *dev_info)
+{
+	struct cflayer *dn;
+	int idx = dev_info->id % DN_CACHE_SIZE;
+	dn = rcu_dereference(muxl->dn_cache[idx]);
+	if (dn == NULL || dn->id != dev_info->id) {
+		spin_lock_bh(&muxl->transmit_lock);
+		dn = get_from_id(&muxl->frml_list, dev_info->id);
+		rcu_assign_pointer(muxl->dn_cache[idx], dn);
+		spin_unlock_bh(&muxl->transmit_lock);
+	}
+	return dn;
+}
+
+struct cflayer *cfmuxl_remove_uplayer(struct cflayer *layr, u8 id)
+{
+	struct cflayer *up;
+	struct cfmuxl *muxl = container_obj(layr);
+	int idx = id % UP_CACHE_SIZE;
+
+	if (id == 0) {
+		pr_warn("Trying to remove control layer\n");
+		return NULL;
+	}
+
+	spin_lock_bh(&muxl->receive_lock);
+	up = get_from_id(&muxl->srvl_list, id);
+	if (up == NULL)
+		goto out;
+
+	RCU_INIT_POINTER(muxl->up_cache[idx], NULL);
+	list_del_rcu(&up->node);
+out:
+	spin_unlock_bh(&muxl->receive_lock);
+	return up;
+}
+
+static int cfmuxl_receive(struct cflayer *layr, struct cfpkt *pkt)
+{
+	int ret;
+	struct cfmuxl *muxl = container_obj(layr);
+	u8 id;
+	struct cflayer *up;
+	if (cfpkt_extr_head(pkt, &id, 1) < 0) {
+		pr_err("erroneous Caif Packet\n");
+		cfpkt_destroy(pkt);
+		return -EPROTO;
+	}
+	rcu_read_lock();
+	up = get_up(muxl, id);
+
+	if (up == NULL) {
+		pr_debug("Received data on unknown link ID = %d (0x%x)"
+			" up == NULL", id, id);
+		cfpkt_destroy(pkt);
+		/*
+		 * Don't return ERROR, since modem misbehaves and sends out
+		 * flow on before linksetup response.
+		 */
+
+		rcu_read_unlock();
+		return /* CFGLU_EPROT; */ 0;
+	}
+
+	/* We can't hold rcu_lock during receive, so take a ref count instead */
+	cfsrvl_get(up);
+	rcu_read_unlock();
+
+	ret = up->receive(up, pkt);
+
+	cfsrvl_put(up);
+	return ret;
+}
+
+static int cfmuxl_transmit(struct cflayer *layr, struct cfpkt *pkt)
+{
+	struct cfmuxl *muxl = container_obj(layr);
+	int err;
+	u8 linkid;
+	struct cflayer *dn;
+	struct caif_payload_info *info = cfpkt_info(pkt);
+	BUG_ON(!info);
+
+	rcu_read_lock();
+
+	dn = get_dn(muxl, info->dev_info);
+	if (dn == NULL) {
+		pr_debug("Send data on unknown phy ID = %d (0x%x)\n",
+			info->dev_info->id, info->dev_info->id);
+		rcu_read_unlock();
+		cfpkt_destroy(pkt);
+		return -ENOTCONN;
+	}
+
+	info->hdr_len += 1;
+	linkid = info->channel_id;
+	cfpkt_add_head(pkt, &linkid, 1);
+
+	/* We can't hold rcu_lock during receive, so take a ref count instead */
+	cffrml_hold(dn);
+
+	rcu_read_unlock();
+
+	err = dn->transmit(dn, pkt);
+
+	cffrml_put(dn);
+	return err;
+}
+
+static void cfmuxl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
+			   int phyid)
+{
+	struct cfmuxl *muxl = container_obj(layr);
+	struct cflayer *layer;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(layer, &muxl->srvl_list, node) {
+
+		if (cfsrvl_phyid_match(layer, phyid) && layer->ctrlcmd) {
+
+			if ((ctrl == _CAIF_CTRLCMD_PHYIF_DOWN_IND ||
+				ctrl == CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND) &&
+					layer->id != 0)
+				cfmuxl_remove_uplayer(layr, layer->id);
+
+			/* NOTE: ctrlcmd is not allowed to block */
+			layer->ctrlcmd(layer, ctrl, phyid);
+		}
+	}
+	rcu_read_unlock();
+}
diff --git a/net/caif/cfpkt_skbuff.c b/net/caif/cfpkt_skbuff.c
new file mode 100644
index 000000000..7796414d4
--- /dev/null
+++ b/net/caif/cfpkt_skbuff.c
@@ -0,0 +1,382 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) ST-Ericsson AB 2010
+ * Author:	Sjur Brendeland
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
+
+#include <linux/string.h>
+#include <linux/skbuff.h>
+#include <linux/export.h>
+#include <net/caif/cfpkt.h>
+
+#define PKT_PREFIX  48
+#define PKT_POSTFIX 2
+#define PKT_LEN_WHEN_EXTENDING 128
+#define PKT_ERROR(pkt, errmsg)		   \
+do {					   \
+	cfpkt_priv(pkt)->erronous = true;  \
+	skb_reset_tail_pointer(&pkt->skb); \
+	pr_warn(errmsg);		   \
+} while (0)
+
+struct cfpktq {
+	struct sk_buff_head head;
+	atomic_t count;
+	/* Lock protects count updates */
+	spinlock_t lock;
+};
+
+/*
+ * net/caif/ is generic and does not
+ * understand SKB, so we do this typecast
+ */
+struct cfpkt {
+	struct sk_buff skb;
+};
+
+/* Private data inside SKB */
+struct cfpkt_priv_data {
+	struct dev_info dev_info;
+	bool erronous;
+};
+
+static inline struct cfpkt_priv_data *cfpkt_priv(struct cfpkt *pkt)
+{
+	return (struct cfpkt_priv_data *) pkt->skb.cb;
+}
+
+static inline bool is_erronous(struct cfpkt *pkt)
+{
+	return cfpkt_priv(pkt)->erronous;
+}
+
+static inline struct sk_buff *pkt_to_skb(struct cfpkt *pkt)
+{
+	return &pkt->skb;
+}
+
+static inline struct cfpkt *skb_to_pkt(struct sk_buff *skb)
+{
+	return (struct cfpkt *) skb;
+}
+
+struct cfpkt *cfpkt_fromnative(enum caif_direction dir, void *nativepkt)
+{
+	struct cfpkt *pkt = skb_to_pkt(nativepkt);
+	cfpkt_priv(pkt)->erronous = false;
+	return pkt;
+}
+EXPORT_SYMBOL(cfpkt_fromnative);
+
+void *cfpkt_tonative(struct cfpkt *pkt)
+{
+	return (void *) pkt;
+}
+EXPORT_SYMBOL(cfpkt_tonative);
+
+static struct cfpkt *cfpkt_create_pfx(u16 len, u16 pfx)
+{
+	struct sk_buff *skb;
+
+	skb = alloc_skb(len + pfx, GFP_ATOMIC);
+	if (unlikely(skb == NULL))
+		return NULL;
+
+	skb_reserve(skb, pfx);
+	return skb_to_pkt(skb);
+}
+
+inline struct cfpkt *cfpkt_create(u16 len)
+{
+	return cfpkt_create_pfx(len + PKT_POSTFIX, PKT_PREFIX);
+}
+
+void cfpkt_destroy(struct cfpkt *pkt)
+{
+	struct sk_buff *skb = pkt_to_skb(pkt);
+	kfree_skb(skb);
+}
+
+inline bool cfpkt_more(struct cfpkt *pkt)
+{
+	struct sk_buff *skb = pkt_to_skb(pkt);
+	return skb->len > 0;
+}
+
+int cfpkt_peek_head(struct cfpkt *pkt, void *data, u16 len)
+{
+	struct sk_buff *skb = pkt_to_skb(pkt);
+	if (skb_headlen(skb) >= len) {
+		memcpy(data, skb->data, len);
+		return 0;
+	}
+	return !cfpkt_extr_head(pkt, data, len) &&
+	    !cfpkt_add_head(pkt, data, len);
+}
+
+int cfpkt_extr_head(struct cfpkt *pkt, void *data, u16 len)
+{
+	struct sk_buff *skb = pkt_to_skb(pkt);
+	u8 *from;
+	if (unlikely(is_erronous(pkt)))
+		return -EPROTO;
+
+	if (unlikely(len > skb->len)) {
+		PKT_ERROR(pkt, "read beyond end of packet\n");
+		return -EPROTO;
+	}
+
+	if (unlikely(len > skb_headlen(skb))) {
+		if (unlikely(skb_linearize(skb) != 0)) {
+			PKT_ERROR(pkt, "linearize failed\n");
+			return -EPROTO;
+		}
+	}
+	from = skb_pull(skb, len);
+	from -= len;
+	if (data)
+		memcpy(data, from, len);
+	return 0;
+}
+EXPORT_SYMBOL(cfpkt_extr_head);
+
+int cfpkt_extr_trail(struct cfpkt *pkt, void *dta, u16 len)
+{
+	struct sk_buff *skb = pkt_to_skb(pkt);
+	u8 *data = dta;
+	u8 *from;
+	if (unlikely(is_erronous(pkt)))
+		return -EPROTO;
+
+	if (unlikely(skb_linearize(skb) != 0)) {
+		PKT_ERROR(pkt, "linearize failed\n");
+		return -EPROTO;
+	}
+	if (unlikely(skb->data + len > skb_tail_pointer(skb))) {
+		PKT_ERROR(pkt, "read beyond end of packet\n");
+		return -EPROTO;
+	}
+	from = skb_tail_pointer(skb) - len;
+	skb_trim(skb, skb->len - len);
+	memcpy(data, from, len);
+	return 0;
+}
+
+int cfpkt_pad_trail(struct cfpkt *pkt, u16 len)
+{
+	return cfpkt_add_body(pkt, NULL, len);
+}
+
+int cfpkt_add_body(struct cfpkt *pkt, const void *data, u16 len)
+{
+	struct sk_buff *skb = pkt_to_skb(pkt);
+	struct sk_buff *lastskb;
+	u8 *to;
+	u16 addlen = 0;
+
+
+	if (unlikely(is_erronous(pkt)))
+		return -EPROTO;
+
+	lastskb = skb;
+
+	/* Check whether we need to add space at the tail */
+	if (unlikely(skb_tailroom(skb) < len)) {
+		if (likely(len < PKT_LEN_WHEN_EXTENDING))
+			addlen = PKT_LEN_WHEN_EXTENDING;
+		else
+			addlen = len;
+	}
+
+	/* Check whether we need to change the SKB before writing to the tail */
+	if (unlikely((addlen > 0) || skb_cloned(skb) || skb_shared(skb))) {
+
+		/* Make sure data is writable */
+		if (unlikely(skb_cow_data(skb, addlen, &lastskb) < 0)) {
+			PKT_ERROR(pkt, "cow failed\n");
+			return -EPROTO;
+		}
+	}
+
+	/* All set to put the last SKB and optionally write data there. */
+	to = pskb_put(skb, lastskb, len);
+	if (likely(data))
+		memcpy(to, data, len);
+	return 0;
+}
+
+inline int cfpkt_addbdy(struct cfpkt *pkt, u8 data)
+{
+	return cfpkt_add_body(pkt, &data, 1);
+}
+
+int cfpkt_add_head(struct cfpkt *pkt, const void *data2, u16 len)
+{
+	struct sk_buff *skb = pkt_to_skb(pkt);
+	struct sk_buff *lastskb;
+	u8 *to;
+	const u8 *data = data2;
+	int ret;
+	if (unlikely(is_erronous(pkt)))
+		return -EPROTO;
+	if (unlikely(skb_headroom(skb) < len)) {
+		PKT_ERROR(pkt, "no headroom\n");
+		return -EPROTO;
+	}
+
+	/* Make sure data is writable */
+	ret = skb_cow_data(skb, 0, &lastskb);
+	if (unlikely(ret < 0)) {
+		PKT_ERROR(pkt, "cow failed\n");
+		return ret;
+	}
+
+	to = skb_push(skb, len);
+	memcpy(to, data, len);
+	return 0;
+}
+EXPORT_SYMBOL(cfpkt_add_head);
+
+inline int cfpkt_add_trail(struct cfpkt *pkt, const void *data, u16 len)
+{
+	return cfpkt_add_body(pkt, data, len);
+}
+
+inline u16 cfpkt_getlen(struct cfpkt *pkt)
+{
+	struct sk_buff *skb = pkt_to_skb(pkt);
+	return skb->len;
+}
+
+int cfpkt_iterate(struct cfpkt *pkt,
+		  u16 (*iter_func)(u16, void *, u16),
+		  u16 data)
+{
+	/*
+	 * Don't care about the performance hit of linearizing,
+	 * Checksum should not be used on high-speed interfaces anyway.
+	 */
+	if (unlikely(is_erronous(pkt)))
+		return -EPROTO;
+	if (unlikely(skb_linearize(&pkt->skb) != 0)) {
+		PKT_ERROR(pkt, "linearize failed\n");
+		return -EPROTO;
+	}
+	return iter_func(data, pkt->skb.data, cfpkt_getlen(pkt));
+}
+
+int cfpkt_setlen(struct cfpkt *pkt, u16 len)
+{
+	struct sk_buff *skb = pkt_to_skb(pkt);
+
+
+	if (unlikely(is_erronous(pkt)))
+		return -EPROTO;
+
+	if (likely(len <= skb->len)) {
+		if (unlikely(skb->data_len))
+			___pskb_trim(skb, len);
+		else
+			skb_trim(skb, len);
+
+		return cfpkt_getlen(pkt);
+	}
+
+	/* Need to expand SKB */
+	if (unlikely(!cfpkt_pad_trail(pkt, len - skb->len)))
+		PKT_ERROR(pkt, "skb_pad_trail failed\n");
+
+	return cfpkt_getlen(pkt);
+}
+
+struct cfpkt *cfpkt_append(struct cfpkt *dstpkt,
+			   struct cfpkt *addpkt,
+			   u16 expectlen)
+{
+	struct sk_buff *dst = pkt_to_skb(dstpkt);
+	struct sk_buff *add = pkt_to_skb(addpkt);
+	u16 addlen = skb_headlen(add);
+	u16 neededtailspace;
+	struct sk_buff *tmp;
+	u16 dstlen;
+	u16 createlen;
+	if (unlikely(is_erronous(dstpkt) || is_erronous(addpkt))) {
+		return dstpkt;
+	}
+	if (expectlen > addlen)
+		neededtailspace = expectlen;
+	else
+		neededtailspace = addlen;
+
+	if (dst->tail + neededtailspace > dst->end) {
+		/* Create a dumplicate of 'dst' with more tail space */
+		struct cfpkt *tmppkt;
+		dstlen = skb_headlen(dst);
+		createlen = dstlen + neededtailspace;
+		tmppkt = cfpkt_create(createlen + PKT_PREFIX + PKT_POSTFIX);
+		if (tmppkt == NULL)
+			return NULL;
+		tmp = pkt_to_skb(tmppkt);
+		skb_put_data(tmp, dst->data, dstlen);
+		cfpkt_destroy(dstpkt);
+		dst = tmp;
+	}
+	skb_put_data(dst, add->data, skb_headlen(add));
+	cfpkt_destroy(addpkt);
+	return skb_to_pkt(dst);
+}
+
+struct cfpkt *cfpkt_split(struct cfpkt *pkt, u16 pos)
+{
+	struct sk_buff *skb2;
+	struct sk_buff *skb = pkt_to_skb(pkt);
+	struct cfpkt *tmppkt;
+	u8 *split = skb->data + pos;
+	u16 len2nd = skb_tail_pointer(skb) - split;
+
+	if (unlikely(is_erronous(pkt)))
+		return NULL;
+
+	if (skb->data + pos > skb_tail_pointer(skb)) {
+		PKT_ERROR(pkt, "trying to split beyond end of packet\n");
+		return NULL;
+	}
+
+	/* Create a new packet for the second part of the data */
+	tmppkt = cfpkt_create_pfx(len2nd + PKT_PREFIX + PKT_POSTFIX,
+				  PKT_PREFIX);
+	if (tmppkt == NULL)
+		return NULL;
+	skb2 = pkt_to_skb(tmppkt);
+
+
+	if (skb2 == NULL)
+		return NULL;
+
+	skb_put_data(skb2, split, len2nd);
+
+	/* Reduce the length of the original packet */
+	skb_trim(skb, pos);
+
+	skb2->priority = skb->priority;
+	return skb_to_pkt(skb2);
+}
+
+bool cfpkt_erroneous(struct cfpkt *pkt)
+{
+	return cfpkt_priv(pkt)->erronous;
+}
+
+struct caif_payload_info *cfpkt_info(struct cfpkt *pkt)
+{
+	return (struct caif_payload_info *)&pkt_to_skb(pkt)->cb;
+}
+EXPORT_SYMBOL(cfpkt_info);
+
+void cfpkt_set_prio(struct cfpkt *pkt, int prio)
+{
+	pkt_to_skb(pkt)->priority = prio;
+}
+EXPORT_SYMBOL(cfpkt_set_prio);
diff --git a/net/caif/cfrfml.c b/net/caif/cfrfml.c
new file mode 100644
index 000000000..7b0af33bd
--- /dev/null
+++ b/net/caif/cfrfml.c
@@ -0,0 +1,299 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) ST-Ericsson AB 2010
+ * Author:	Sjur Brendeland
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
+
+#include <linux/stddef.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <asm/unaligned.h>
+#include <net/caif/caif_layer.h>
+#include <net/caif/cfsrvl.h>
+#include <net/caif/cfpkt.h>
+
+#define container_obj(layr) container_of(layr, struct cfrfml, serv.layer)
+#define RFM_SEGMENTATION_BIT 0x01
+#define RFM_HEAD_SIZE 7
+
+static int cfrfml_receive(struct cflayer *layr, struct cfpkt *pkt);
+static int cfrfml_transmit(struct cflayer *layr, struct cfpkt *pkt);
+
+struct cfrfml {
+	struct cfsrvl serv;
+	struct cfpkt *incomplete_frm;
+	int fragment_size;
+	u8  seghead[6];
+	u16 pdu_size;
+	/* Protects serialized processing of packets */
+	spinlock_t sync;
+};
+
+static void cfrfml_release(struct cflayer *layer)
+{
+	struct cfsrvl *srvl = container_of(layer, struct cfsrvl, layer);
+	struct cfrfml *rfml = container_obj(&srvl->layer);
+
+	if (rfml->incomplete_frm)
+		cfpkt_destroy(rfml->incomplete_frm);
+
+	kfree(srvl);
+}
+
+struct cflayer *cfrfml_create(u8 channel_id, struct dev_info *dev_info,
+			      int mtu_size)
+{
+	int tmp;
+	struct cfrfml *this = kzalloc(sizeof(struct cfrfml), GFP_ATOMIC);
+
+	if (!this)
+		return NULL;
+
+	cfsrvl_init(&this->serv, channel_id, dev_info, false);
+	this->serv.release = cfrfml_release;
+	this->serv.layer.receive = cfrfml_receive;
+	this->serv.layer.transmit = cfrfml_transmit;
+
+	/* Round down to closest multiple of 16 */
+	tmp = (mtu_size - RFM_HEAD_SIZE - 6) / 16;
+	tmp *= 16;
+
+	this->fragment_size = tmp;
+	spin_lock_init(&this->sync);
+	snprintf(this->serv.layer.name, CAIF_LAYER_NAME_SZ,
+		"rfm%d", channel_id);
+
+	return &this->serv.layer;
+}
+
+static struct cfpkt *rfm_append(struct cfrfml *rfml, char *seghead,
+				struct cfpkt *pkt, int *err)
+{
+	struct cfpkt *tmppkt;
+	*err = -EPROTO;
+	/* n-th but not last segment */
+
+	if (cfpkt_extr_head(pkt, seghead, 6) < 0)
+		return NULL;
+
+	/* Verify correct header */
+	if (memcmp(seghead, rfml->seghead, 6) != 0)
+		return NULL;
+
+	tmppkt = cfpkt_append(rfml->incomplete_frm, pkt,
+			rfml->pdu_size + RFM_HEAD_SIZE);
+
+	/* If cfpkt_append failes input pkts are not freed */
+	*err = -ENOMEM;
+	if (tmppkt == NULL)
+		return NULL;
+
+	*err = 0;
+	return tmppkt;
+}
+
+static int cfrfml_receive(struct cflayer *layr, struct cfpkt *pkt)
+{
+	u8 tmp;
+	bool segmented;
+	int err;
+	u8 seghead[6];
+	struct cfrfml *rfml;
+	struct cfpkt *tmppkt = NULL;
+
+	caif_assert(layr->up != NULL);
+	caif_assert(layr->receive != NULL);
+	rfml = container_obj(layr);
+	spin_lock(&rfml->sync);
+
+	err = -EPROTO;
+	if (cfpkt_extr_head(pkt, &tmp, 1) < 0)
+		goto out;
+	segmented = tmp & RFM_SEGMENTATION_BIT;
+
+	if (segmented) {
+		if (rfml->incomplete_frm == NULL) {
+			/* Initial Segment */
+			if (cfpkt_peek_head(pkt, rfml->seghead, 6) != 0)
+				goto out;
+
+			rfml->pdu_size = get_unaligned_le16(rfml->seghead+4);
+
+			if (cfpkt_erroneous(pkt))
+				goto out;
+			rfml->incomplete_frm = pkt;
+			pkt = NULL;
+		} else {
+
+			tmppkt = rfm_append(rfml, seghead, pkt, &err);
+			if (tmppkt == NULL)
+				goto out;
+
+			if (cfpkt_erroneous(tmppkt))
+				goto out;
+
+			rfml->incomplete_frm = tmppkt;
+
+
+			if (cfpkt_erroneous(tmppkt))
+				goto out;
+		}
+		err = 0;
+		goto out;
+	}
+
+	if (rfml->incomplete_frm) {
+
+		/* Last Segment */
+		tmppkt = rfm_append(rfml, seghead, pkt, &err);
+		if (tmppkt == NULL)
+			goto out;
+
+		if (cfpkt_erroneous(tmppkt))
+			goto out;
+
+		rfml->incomplete_frm = NULL;
+		pkt = tmppkt;
+		tmppkt = NULL;
+
+		/* Verify that length is correct */
+		err = -EPROTO;
+		if (rfml->pdu_size != cfpkt_getlen(pkt) - RFM_HEAD_SIZE + 1)
+			goto out;
+	}
+
+	err = rfml->serv.layer.up->receive(rfml->serv.layer.up, pkt);
+
+out:
+
+	if (err != 0) {
+		if (tmppkt)
+			cfpkt_destroy(tmppkt);
+		if (pkt)
+			cfpkt_destroy(pkt);
+		if (rfml->incomplete_frm)
+			cfpkt_destroy(rfml->incomplete_frm);
+		rfml->incomplete_frm = NULL;
+
+		pr_info("Connection error %d triggered on RFM link\n", err);
+
+		/* Trigger connection error upon failure.*/
+		layr->up->ctrlcmd(layr->up, CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND,
+					rfml->serv.dev_info.id);
+	}
+	spin_unlock(&rfml->sync);
+
+	if (unlikely(err == -EAGAIN))
+		/* It is not possible to recover after drop of a fragment */
+		err = -EIO;
+
+	return err;
+}
+
+
+static int cfrfml_transmit_segment(struct cfrfml *rfml, struct cfpkt *pkt)
+{
+	caif_assert(cfpkt_getlen(pkt) < rfml->fragment_size + RFM_HEAD_SIZE);
+
+	/* Add info for MUX-layer to route the packet out. */
+	cfpkt_info(pkt)->channel_id = rfml->serv.layer.id;
+
+	/*
+	 * To optimize alignment, we add up the size of CAIF header before
+	 * payload.
+	 */
+	cfpkt_info(pkt)->hdr_len = RFM_HEAD_SIZE;
+	cfpkt_info(pkt)->dev_info = &rfml->serv.dev_info;
+
+	return rfml->serv.layer.dn->transmit(rfml->serv.layer.dn, pkt);
+}
+
+static int cfrfml_transmit(struct cflayer *layr, struct cfpkt *pkt)
+{
+	int err;
+	u8 seg;
+	u8 head[6];
+	struct cfpkt *rearpkt = NULL;
+	struct cfpkt *frontpkt = pkt;
+	struct cfrfml *rfml = container_obj(layr);
+
+	caif_assert(layr->dn != NULL);
+	caif_assert(layr->dn->transmit != NULL);
+
+	if (!cfsrvl_ready(&rfml->serv, &err))
+		goto out;
+
+	err = -EPROTO;
+	if (cfpkt_getlen(pkt) <= RFM_HEAD_SIZE-1)
+		goto out;
+
+	err = 0;
+	if (cfpkt_getlen(pkt) > rfml->fragment_size + RFM_HEAD_SIZE)
+		err = cfpkt_peek_head(pkt, head, 6);
+
+	if (err != 0)
+		goto out;
+
+	while (cfpkt_getlen(frontpkt) > rfml->fragment_size + RFM_HEAD_SIZE) {
+
+		seg = 1;
+		err = -EPROTO;
+
+		if (cfpkt_add_head(frontpkt, &seg, 1) < 0)
+			goto out;
+		/*
+		 * On OOM error cfpkt_split returns NULL.
+		 *
+		 * NOTE: Segmented pdu is not correctly aligned.
+		 * This has negative performance impact.
+		 */
+
+		rearpkt = cfpkt_split(frontpkt, rfml->fragment_size);
+		if (rearpkt == NULL)
+			goto out;
+
+		err = cfrfml_transmit_segment(rfml, frontpkt);
+
+		if (err != 0) {
+			frontpkt = NULL;
+			goto out;
+		}
+
+		frontpkt = rearpkt;
+		rearpkt = NULL;
+
+		err = -EPROTO;
+		if (cfpkt_add_head(frontpkt, head, 6) < 0)
+			goto out;
+
+	}
+
+	seg = 0;
+	err = -EPROTO;
+
+	if (cfpkt_add_head(frontpkt, &seg, 1) < 0)
+		goto out;
+
+	err = cfrfml_transmit_segment(rfml, frontpkt);
+
+	frontpkt = NULL;
+out:
+
+	if (err != 0) {
+		pr_info("Connection error %d triggered on RFM link\n", err);
+		/* Trigger connection error upon failure.*/
+
+		layr->up->ctrlcmd(layr->up, CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND,
+					rfml->serv.dev_info.id);
+
+		if (rearpkt)
+			cfpkt_destroy(rearpkt);
+
+		if (frontpkt)
+			cfpkt_destroy(frontpkt);
+	}
+
+	return err;
+}
diff --git a/net/caif/cfserl.c b/net/caif/cfserl.c
new file mode 100644
index 000000000..aee11c74d
--- /dev/null
+++ b/net/caif/cfserl.c
@@ -0,0 +1,192 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) ST-Ericsson AB 2010
+ * Author:	Sjur Brendeland
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
+
+#include <linux/stddef.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <net/caif/caif_layer.h>
+#include <net/caif/cfpkt.h>
+#include <net/caif/cfserl.h>
+
+#define container_obj(layr) ((struct cfserl *) layr)
+
+#define CFSERL_STX 0x02
+#define SERIAL_MINIUM_PACKET_SIZE 4
+#define SERIAL_MAX_FRAMESIZE 4096
+struct cfserl {
+	struct cflayer layer;
+	struct cfpkt *incomplete_frm;
+	/* Protects parallel processing of incoming packets */
+	spinlock_t sync;
+	bool usestx;
+};
+
+static int cfserl_receive(struct cflayer *layr, struct cfpkt *pkt);
+static int cfserl_transmit(struct cflayer *layr, struct cfpkt *pkt);
+static void cfserl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
+			   int phyid);
+
+void cfserl_release(struct cflayer *layer)
+{
+	kfree(layer);
+}
+
+struct cflayer *cfserl_create(int instance, bool use_stx)
+{
+	struct cfserl *this = kzalloc(sizeof(struct cfserl), GFP_ATOMIC);
+	if (!this)
+		return NULL;
+	caif_assert(offsetof(struct cfserl, layer) == 0);
+	this->layer.receive = cfserl_receive;
+	this->layer.transmit = cfserl_transmit;
+	this->layer.ctrlcmd = cfserl_ctrlcmd;
+	this->usestx = use_stx;
+	spin_lock_init(&this->sync);
+	snprintf(this->layer.name, CAIF_LAYER_NAME_SZ, "ser1");
+	return &this->layer;
+}
+
+static int cfserl_receive(struct cflayer *l, struct cfpkt *newpkt)
+{
+	struct cfserl *layr = container_obj(l);
+	u16 pkt_len;
+	struct cfpkt *pkt = NULL;
+	struct cfpkt *tail_pkt = NULL;
+	u8 tmp8;
+	u16 tmp;
+	u8 stx = CFSERL_STX;
+	int ret;
+	u16 expectlen = 0;
+
+	caif_assert(newpkt != NULL);
+	spin_lock(&layr->sync);
+
+	if (layr->incomplete_frm != NULL) {
+		layr->incomplete_frm =
+		    cfpkt_append(layr->incomplete_frm, newpkt, expectlen);
+		pkt = layr->incomplete_frm;
+		if (pkt == NULL) {
+			spin_unlock(&layr->sync);
+			return -ENOMEM;
+		}
+	} else {
+		pkt = newpkt;
+	}
+	layr->incomplete_frm = NULL;
+
+	do {
+		/* Search for STX at start of pkt if STX is used */
+		if (layr->usestx) {
+			cfpkt_extr_head(pkt, &tmp8, 1);
+			if (tmp8 != CFSERL_STX) {
+				while (cfpkt_more(pkt)
+				       && tmp8 != CFSERL_STX) {
+					cfpkt_extr_head(pkt, &tmp8, 1);
+				}
+				if (!cfpkt_more(pkt)) {
+					cfpkt_destroy(pkt);
+					layr->incomplete_frm = NULL;
+					spin_unlock(&layr->sync);
+					return -EPROTO;
+				}
+			}
+		}
+
+		pkt_len = cfpkt_getlen(pkt);
+
+		/*
+		 *  pkt_len is the accumulated length of the packet data
+		 *  we have received so far.
+		 *  Exit if frame doesn't hold length.
+		 */
+
+		if (pkt_len < 2) {
+			if (layr->usestx)
+				cfpkt_add_head(pkt, &stx, 1);
+			layr->incomplete_frm = pkt;
+			spin_unlock(&layr->sync);
+			return 0;
+		}
+
+		/*
+		 *  Find length of frame.
+		 *  expectlen is the length we need for a full frame.
+		 */
+		cfpkt_peek_head(pkt, &tmp, 2);
+		expectlen = le16_to_cpu(tmp) + 2;
+		/*
+		 * Frame error handling
+		 */
+		if (expectlen < SERIAL_MINIUM_PACKET_SIZE
+		    || expectlen > SERIAL_MAX_FRAMESIZE) {
+			if (!layr->usestx) {
+				if (pkt != NULL)
+					cfpkt_destroy(pkt);
+				layr->incomplete_frm = NULL;
+				spin_unlock(&layr->sync);
+				return -EPROTO;
+			}
+			continue;
+		}
+
+		if (pkt_len < expectlen) {
+			/* Too little received data */
+			if (layr->usestx)
+				cfpkt_add_head(pkt, &stx, 1);
+			layr->incomplete_frm = pkt;
+			spin_unlock(&layr->sync);
+			return 0;
+		}
+
+		/*
+		 * Enough data for at least one frame.
+		 * Split the frame, if too long
+		 */
+		if (pkt_len > expectlen)
+			tail_pkt = cfpkt_split(pkt, expectlen);
+		else
+			tail_pkt = NULL;
+
+		/* Send the first part of packet upwards.*/
+		spin_unlock(&layr->sync);
+		ret = layr->layer.up->receive(layr->layer.up, pkt);
+		spin_lock(&layr->sync);
+		if (ret == -EILSEQ) {
+			if (layr->usestx) {
+				if (tail_pkt != NULL)
+					pkt = cfpkt_append(pkt, tail_pkt, 0);
+				/* Start search for next STX if frame failed */
+				continue;
+			} else {
+				cfpkt_destroy(pkt);
+				pkt = NULL;
+			}
+		}
+
+		pkt = tail_pkt;
+
+	} while (pkt != NULL);
+
+	spin_unlock(&layr->sync);
+	return 0;
+}
+
+static int cfserl_transmit(struct cflayer *layer, struct cfpkt *newpkt)
+{
+	struct cfserl *layr = container_obj(layer);
+	u8 tmp8 = CFSERL_STX;
+	if (layr->usestx)
+		cfpkt_add_head(newpkt, &tmp8, 1);
+	return layer->dn->transmit(layer->dn, newpkt);
+}
+
+static void cfserl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
+			   int phyid)
+{
+	layr->up->ctrlcmd(layr->up, ctrl, phyid);
+}
diff --git a/net/caif/cfsrvl.c b/net/caif/cfsrvl.c
new file mode 100644
index 000000000..9cef9496a
--- /dev/null
+++ b/net/caif/cfsrvl.c
@@ -0,0 +1,220 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) ST-Ericsson AB 2010
+ * Author:	Sjur Brendeland
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/pkt_sched.h>
+#include <net/caif/caif_layer.h>
+#include <net/caif/cfsrvl.h>
+#include <net/caif/cfpkt.h>
+#include <net/caif/caif_dev.h>
+
+#define SRVL_CTRL_PKT_SIZE 1
+#define SRVL_FLOW_OFF 0x81
+#define SRVL_FLOW_ON  0x80
+#define SRVL_SET_PIN  0x82
+
+#define container_obj(layr) container_of(layr, struct cfsrvl, layer)
+
+static void cfservl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
+			    int phyid)
+{
+	struct cfsrvl *service = container_obj(layr);
+
+	if (layr->up == NULL || layr->up->ctrlcmd == NULL)
+		return;
+
+	switch (ctrl) {
+	case CAIF_CTRLCMD_INIT_RSP:
+		service->open = true;
+		layr->up->ctrlcmd(layr->up, ctrl, phyid);
+		break;
+	case CAIF_CTRLCMD_DEINIT_RSP:
+	case CAIF_CTRLCMD_INIT_FAIL_RSP:
+		service->open = false;
+		layr->up->ctrlcmd(layr->up, ctrl, phyid);
+		break;
+	case _CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND:
+		if (phyid != service->dev_info.id)
+			break;
+		if (service->modem_flow_on)
+			layr->up->ctrlcmd(layr->up,
+					  CAIF_CTRLCMD_FLOW_OFF_IND, phyid);
+		service->phy_flow_on = false;
+		break;
+	case _CAIF_CTRLCMD_PHYIF_FLOW_ON_IND:
+		if (phyid != service->dev_info.id)
+			return;
+		if (service->modem_flow_on) {
+			layr->up->ctrlcmd(layr->up,
+					   CAIF_CTRLCMD_FLOW_ON_IND,
+					   phyid);
+		}
+		service->phy_flow_on = true;
+		break;
+	case CAIF_CTRLCMD_FLOW_OFF_IND:
+		if (service->phy_flow_on) {
+			layr->up->ctrlcmd(layr->up,
+					  CAIF_CTRLCMD_FLOW_OFF_IND, phyid);
+		}
+		service->modem_flow_on = false;
+		break;
+	case CAIF_CTRLCMD_FLOW_ON_IND:
+		if (service->phy_flow_on) {
+			layr->up->ctrlcmd(layr->up,
+					  CAIF_CTRLCMD_FLOW_ON_IND, phyid);
+		}
+		service->modem_flow_on = true;
+		break;
+	case _CAIF_CTRLCMD_PHYIF_DOWN_IND:
+		/* In case interface is down, let's fake a remove shutdown */
+		layr->up->ctrlcmd(layr->up,
+				CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND, phyid);
+		break;
+	case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
+		layr->up->ctrlcmd(layr->up, ctrl, phyid);
+		break;
+	default:
+		pr_warn("Unexpected ctrl in cfsrvl (%d)\n", ctrl);
+		/* We have both modem and phy flow on, send flow on */
+		layr->up->ctrlcmd(layr->up, ctrl, phyid);
+		service->phy_flow_on = true;
+		break;
+	}
+}
+
+static int cfservl_modemcmd(struct cflayer *layr, enum caif_modemcmd ctrl)
+{
+	struct cfsrvl *service = container_obj(layr);
+
+	caif_assert(layr != NULL);
+	caif_assert(layr->dn != NULL);
+	caif_assert(layr->dn->transmit != NULL);
+
+	if (!service->supports_flowctrl)
+		return 0;
+
+	switch (ctrl) {
+	case CAIF_MODEMCMD_FLOW_ON_REQ:
+		{
+			struct cfpkt *pkt;
+			struct caif_payload_info *info;
+			u8 flow_on = SRVL_FLOW_ON;
+			pkt = cfpkt_create(SRVL_CTRL_PKT_SIZE);
+			if (!pkt)
+				return -ENOMEM;
+
+			if (cfpkt_add_head(pkt, &flow_on, 1) < 0) {
+				pr_err("Packet is erroneous!\n");
+				cfpkt_destroy(pkt);
+				return -EPROTO;
+			}
+			info = cfpkt_info(pkt);
+			info->channel_id = service->layer.id;
+			info->hdr_len = 1;
+			info->dev_info = &service->dev_info;
+			cfpkt_set_prio(pkt, TC_PRIO_CONTROL);
+			return layr->dn->transmit(layr->dn, pkt);
+		}
+	case CAIF_MODEMCMD_FLOW_OFF_REQ:
+		{
+			struct cfpkt *pkt;
+			struct caif_payload_info *info;
+			u8 flow_off = SRVL_FLOW_OFF;
+			pkt = cfpkt_create(SRVL_CTRL_PKT_SIZE);
+			if (!pkt)
+				return -ENOMEM;
+
+			if (cfpkt_add_head(pkt, &flow_off, 1) < 0) {
+				pr_err("Packet is erroneous!\n");
+				cfpkt_destroy(pkt);
+				return -EPROTO;
+			}
+			info = cfpkt_info(pkt);
+			info->channel_id = service->layer.id;
+			info->hdr_len = 1;
+			info->dev_info = &service->dev_info;
+			cfpkt_set_prio(pkt, TC_PRIO_CONTROL);
+			return layr->dn->transmit(layr->dn, pkt);
+		}
+	default:
+	  break;
+	}
+	return -EINVAL;
+}
+
+static void cfsrvl_release(struct cflayer *layer)
+{
+	struct cfsrvl *service = container_of(layer, struct cfsrvl, layer);
+	kfree(service);
+}
+
+void cfsrvl_init(struct cfsrvl *service,
+		 u8 channel_id,
+		 struct dev_info *dev_info,
+		 bool supports_flowctrl)
+{
+	caif_assert(offsetof(struct cfsrvl, layer) == 0);
+	service->open = false;
+	service->modem_flow_on = true;
+	service->phy_flow_on = true;
+	service->layer.id = channel_id;
+	service->layer.ctrlcmd = cfservl_ctrlcmd;
+	service->layer.modemcmd = cfservl_modemcmd;
+	service->dev_info = *dev_info;
+	service->supports_flowctrl = supports_flowctrl;
+	service->release = cfsrvl_release;
+}
+
+bool cfsrvl_ready(struct cfsrvl *service, int *err)
+{
+	if (!service->open) {
+		*err = -ENOTCONN;
+		return false;
+	}
+	return true;
+}
+
+u8 cfsrvl_getphyid(struct cflayer *layer)
+{
+	struct cfsrvl *servl = container_obj(layer);
+	return servl->dev_info.id;
+}
+
+bool cfsrvl_phyid_match(struct cflayer *layer, int phyid)
+{
+	struct cfsrvl *servl = container_obj(layer);
+	return servl->dev_info.id == phyid;
+}
+
+void caif_free_client(struct cflayer *adap_layer)
+{
+	struct cfsrvl *servl;
+	if (adap_layer == NULL || adap_layer->dn == NULL)
+		return;
+	servl = container_obj(adap_layer->dn);
+	servl->release(&servl->layer);
+}
+EXPORT_SYMBOL(caif_free_client);
+
+void caif_client_register_refcnt(struct cflayer *adapt_layer,
+				 void (*hold)(struct cflayer *lyr),
+				 void (*put)(struct cflayer *lyr))
+{
+	struct cfsrvl *service;
+
+	if (WARN_ON(adapt_layer == NULL || adapt_layer->dn == NULL))
+		return;
+	service = container_of(adapt_layer->dn, struct cfsrvl, layer);
+	service->hold = hold;
+	service->put = put;
+}
+EXPORT_SYMBOL(caif_client_register_refcnt);
diff --git a/net/caif/cfutill.c b/net/caif/cfutill.c
new file mode 100644
index 000000000..b2e47ede9
--- /dev/null
+++ b/net/caif/cfutill.c
@@ -0,0 +1,104 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) ST-Ericsson AB 2010
+ * Author:	Sjur Brendeland
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <net/caif/caif_layer.h>
+#include <net/caif/cfsrvl.h>
+#include <net/caif/cfpkt.h>
+
+#define container_obj(layr) ((struct cfsrvl *) layr)
+#define UTIL_PAYLOAD  0x00
+#define UTIL_CMD_BIT  0x80
+#define UTIL_REMOTE_SHUTDOWN 0x82
+#define UTIL_FLOW_OFF 0x81
+#define UTIL_FLOW_ON  0x80
+
+static int cfutill_receive(struct cflayer *layr, struct cfpkt *pkt);
+static int cfutill_transmit(struct cflayer *layr, struct cfpkt *pkt);
+
+struct cflayer *cfutill_create(u8 channel_id, struct dev_info *dev_info)
+{
+	struct cfsrvl *util = kzalloc(sizeof(struct cfsrvl), GFP_ATOMIC);
+	if (!util)
+		return NULL;
+	caif_assert(offsetof(struct cfsrvl, layer) == 0);
+	cfsrvl_init(util, channel_id, dev_info, true);
+	util->layer.receive = cfutill_receive;
+	util->layer.transmit = cfutill_transmit;
+	snprintf(util->layer.name, CAIF_LAYER_NAME_SZ, "util1");
+	return &util->layer;
+}
+
+static int cfutill_receive(struct cflayer *layr, struct cfpkt *pkt)
+{
+	u8 cmd = -1;
+	struct cfsrvl *service = container_obj(layr);
+	caif_assert(layr != NULL);
+	caif_assert(layr->up != NULL);
+	caif_assert(layr->up->receive != NULL);
+	caif_assert(layr->up->ctrlcmd != NULL);
+	if (cfpkt_extr_head(pkt, &cmd, 1) < 0) {
+		pr_err("Packet is erroneous!\n");
+		cfpkt_destroy(pkt);
+		return -EPROTO;
+	}
+
+	switch (cmd) {
+	case UTIL_PAYLOAD:
+		return layr->up->receive(layr->up, pkt);
+	case UTIL_FLOW_OFF:
+		layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_OFF_IND, 0);
+		cfpkt_destroy(pkt);
+		return 0;
+	case UTIL_FLOW_ON:
+		layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_ON_IND, 0);
+		cfpkt_destroy(pkt);
+		return 0;
+	case UTIL_REMOTE_SHUTDOWN:	/* Remote Shutdown Request */
+		pr_err("REMOTE SHUTDOWN REQUEST RECEIVED\n");
+		layr->ctrlcmd(layr, CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND, 0);
+		service->open = false;
+		cfpkt_destroy(pkt);
+		return 0;
+	default:
+		cfpkt_destroy(pkt);
+		pr_warn("Unknown service control %d (0x%x)\n", cmd, cmd);
+		return -EPROTO;
+	}
+}
+
+static int cfutill_transmit(struct cflayer *layr, struct cfpkt *pkt)
+{
+	u8 zero = 0;
+	struct caif_payload_info *info;
+	int ret;
+	struct cfsrvl *service = container_obj(layr);
+	caif_assert(layr != NULL);
+	caif_assert(layr->dn != NULL);
+	caif_assert(layr->dn->transmit != NULL);
+
+	if (!cfsrvl_ready(service, &ret)) {
+		cfpkt_destroy(pkt);
+		return ret;
+	}
+
+	cfpkt_add_head(pkt, &zero, 1);
+	/* Add info for MUX-layer to route the packet out. */
+	info = cfpkt_info(pkt);
+	info->channel_id = service->layer.id;
+	/*
+	 * To optimize alignment, we add up the size of CAIF header before
+	 * payload.
+	 */
+	info->hdr_len = 1;
+	info->dev_info = &service->dev_info;
+	return layr->dn->transmit(layr->dn, pkt);
+}
diff --git a/net/caif/cfveil.c b/net/caif/cfveil.c
new file mode 100644
index 000000000..db2274b94
--- /dev/null
+++ b/net/caif/cfveil.c
@@ -0,0 +1,101 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) ST-Ericsson AB 2010
+ * Author:	Sjur Brendeland
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
+
+#include <linux/stddef.h>
+#include <linux/slab.h>
+#include <net/caif/caif_layer.h>
+#include <net/caif/cfsrvl.h>
+#include <net/caif/cfpkt.h>
+
+#define VEI_PAYLOAD  0x00
+#define VEI_CMD_BIT  0x80
+#define VEI_FLOW_OFF 0x81
+#define VEI_FLOW_ON  0x80
+#define VEI_SET_PIN  0x82
+
+#define container_obj(layr) container_of(layr, struct cfsrvl, layer)
+
+static int cfvei_receive(struct cflayer *layr, struct cfpkt *pkt);
+static int cfvei_transmit(struct cflayer *layr, struct cfpkt *pkt);
+
+struct cflayer *cfvei_create(u8 channel_id, struct dev_info *dev_info)
+{
+	struct cfsrvl *vei = kzalloc(sizeof(struct cfsrvl), GFP_ATOMIC);
+	if (!vei)
+		return NULL;
+	caif_assert(offsetof(struct cfsrvl, layer) == 0);
+	cfsrvl_init(vei, channel_id, dev_info, true);
+	vei->layer.receive = cfvei_receive;
+	vei->layer.transmit = cfvei_transmit;
+	snprintf(vei->layer.name, CAIF_LAYER_NAME_SZ, "vei%d", channel_id);
+	return &vei->layer;
+}
+
+static int cfvei_receive(struct cflayer *layr, struct cfpkt *pkt)
+{
+	u8 cmd;
+	int ret;
+	caif_assert(layr->up != NULL);
+	caif_assert(layr->receive != NULL);
+	caif_assert(layr->ctrlcmd != NULL);
+
+
+	if (cfpkt_extr_head(pkt, &cmd, 1) < 0) {
+		pr_err("Packet is erroneous!\n");
+		cfpkt_destroy(pkt);
+		return -EPROTO;
+	}
+	switch (cmd) {
+	case VEI_PAYLOAD:
+		ret = layr->up->receive(layr->up, pkt);
+		return ret;
+	case VEI_FLOW_OFF:
+		layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_OFF_IND, 0);
+		cfpkt_destroy(pkt);
+		return 0;
+	case VEI_FLOW_ON:
+		layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_ON_IND, 0);
+		cfpkt_destroy(pkt);
+		return 0;
+	case VEI_SET_PIN:	/* SET RS232 PIN */
+		cfpkt_destroy(pkt);
+		return 0;
+	default:		/* SET RS232 PIN */
+		pr_warn("Unknown VEI control packet %d (0x%x)!\n", cmd, cmd);
+		cfpkt_destroy(pkt);
+		return -EPROTO;
+	}
+}
+
+static int cfvei_transmit(struct cflayer *layr, struct cfpkt *pkt)
+{
+	u8 tmp = 0;
+	struct caif_payload_info *info;
+	int ret;
+	struct cfsrvl *service = container_obj(layr);
+	if (!cfsrvl_ready(service, &ret))
+		goto err;
+	caif_assert(layr->dn != NULL);
+	caif_assert(layr->dn->transmit != NULL);
+
+	if (cfpkt_add_head(pkt, &tmp, 1) < 0) {
+		pr_err("Packet is erroneous!\n");
+		ret = -EPROTO;
+		goto err;
+	}
+
+	/* Add info-> for MUX-layer to route the packet out. */
+	info = cfpkt_info(pkt);
+	info->channel_id = service->layer.id;
+	info->hdr_len = 1;
+	info->dev_info = &service->dev_info;
+	return layr->dn->transmit(layr->dn, pkt);
+err:
+	cfpkt_destroy(pkt);
+	return ret;
+}
diff --git a/net/caif/cfvidl.c b/net/caif/cfvidl.c
new file mode 100644
index 000000000..134bad431
--- /dev/null
+++ b/net/caif/cfvidl.c
@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) ST-Ericsson AB 2010
+ * Author:	Sjur Brendeland
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <net/caif/caif_layer.h>
+#include <net/caif/cfsrvl.h>
+#include <net/caif/cfpkt.h>
+
+#define container_obj(layr) ((struct cfsrvl *) layr)
+
+static int cfvidl_receive(struct cflayer *layr, struct cfpkt *pkt);
+static int cfvidl_transmit(struct cflayer *layr, struct cfpkt *pkt);
+
+struct cflayer *cfvidl_create(u8 channel_id, struct dev_info *dev_info)
+{
+	struct cfsrvl *vid = kzalloc(sizeof(struct cfsrvl), GFP_ATOMIC);
+	if (!vid)
+		return NULL;
+	caif_assert(offsetof(struct cfsrvl, layer) == 0);
+
+	cfsrvl_init(vid, channel_id, dev_info, false);
+	vid->layer.receive = cfvidl_receive;
+	vid->layer.transmit = cfvidl_transmit;
+	snprintf(vid->layer.name, CAIF_LAYER_NAME_SZ, "vid1");
+	return &vid->layer;
+}
+
+static int cfvidl_receive(struct cflayer *layr, struct cfpkt *pkt)
+{
+	u32 videoheader;
+	if (cfpkt_extr_head(pkt, &videoheader, 4) < 0) {
+		pr_err("Packet is erroneous!\n");
+		cfpkt_destroy(pkt);
+		return -EPROTO;
+	}
+	return layr->up->receive(layr->up, pkt);
+}
+
+static int cfvidl_transmit(struct cflayer *layr, struct cfpkt *pkt)
+{
+	struct cfsrvl *service = container_obj(layr);
+	struct caif_payload_info *info;
+	u32 videoheader = 0;
+	int ret;
+
+	if (!cfsrvl_ready(service, &ret)) {
+		cfpkt_destroy(pkt);
+		return ret;
+	}
+
+	cfpkt_add_head(pkt, &videoheader, 4);
+	/* Add info for MUX-layer to route the packet out */
+	info = cfpkt_info(pkt);
+	info->channel_id = service->layer.id;
+	info->dev_info = &service->dev_info;
+	return layr->dn->transmit(layr->dn, pkt);
+}
diff --git a/net/caif/chnl_net.c b/net/caif/chnl_net.c
new file mode 100644
index 000000000..f35fc87c4
--- /dev/null
+++ b/net/caif/chnl_net.c
@@ -0,0 +1,531 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) ST-Ericsson AB 2010
+ * Authors:	Sjur Brendeland
+ *		Daniel Martensson
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
+
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/if_ether.h>
+#include <linux/ip.h>
+#include <linux/sched.h>
+#include <linux/sockios.h>
+#include <linux/caif/if_caif.h>
+#include <net/rtnetlink.h>
+#include <net/caif/caif_layer.h>
+#include <net/caif/cfpkt.h>
+#include <net/caif/caif_dev.h>
+
+/* GPRS PDP connection has MTU to 1500 */
+#define GPRS_PDP_MTU 1500
+/* 5 sec. connect timeout */
+#define CONNECT_TIMEOUT (5 * HZ)
+#define CAIF_NET_DEFAULT_QUEUE_LEN 500
+#define UNDEF_CONNID 0xffffffff
+
+/*This list is protected by the rtnl lock. */
+static LIST_HEAD(chnl_net_list);
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_RTNL_LINK("caif");
+
+enum caif_states {
+	CAIF_CONNECTED		= 1,
+	CAIF_CONNECTING,
+	CAIF_DISCONNECTED,
+	CAIF_SHUTDOWN
+};
+
+struct chnl_net {
+	struct cflayer chnl;
+	struct caif_connect_request conn_req;
+	struct list_head list_field;
+	struct net_device *netdev;
+	char name[256];
+	wait_queue_head_t netmgmt_wq;
+	/* Flow status to remember and control the transmission. */
+	bool flowenabled;
+	enum caif_states state;
+};
+
+static int chnl_recv_cb(struct cflayer *layr, struct cfpkt *pkt)
+{
+	struct sk_buff *skb;
+	struct chnl_net *priv;
+	int pktlen;
+	const u8 *ip_version;
+	u8 buf;
+
+	priv = container_of(layr, struct chnl_net, chnl);
+
+	skb = (struct sk_buff *) cfpkt_tonative(pkt);
+
+	/* Get length of CAIF packet. */
+	pktlen = skb->len;
+
+	/* Pass some minimum information and
+	 * send the packet to the net stack.
+	 */
+	skb->dev = priv->netdev;
+
+	/* check the version of IP */
+	ip_version = skb_header_pointer(skb, 0, 1, &buf);
+	if (!ip_version) {
+		kfree_skb(skb);
+		return -EINVAL;
+	}
+
+	switch (*ip_version >> 4) {
+	case 4:
+		skb->protocol = htons(ETH_P_IP);
+		break;
+	case 6:
+		skb->protocol = htons(ETH_P_IPV6);
+		break;
+	default:
+		kfree_skb(skb);
+		priv->netdev->stats.rx_errors++;
+		return -EINVAL;
+	}
+
+	/* If we change the header in loop mode, the checksum is corrupted. */
+	if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP)
+		skb->ip_summed = CHECKSUM_UNNECESSARY;
+	else
+		skb->ip_summed = CHECKSUM_NONE;
+
+	netif_rx(skb);
+
+	/* Update statistics. */
+	priv->netdev->stats.rx_packets++;
+	priv->netdev->stats.rx_bytes += pktlen;
+
+	return 0;
+}
+
+static int delete_device(struct chnl_net *dev)
+{
+	ASSERT_RTNL();
+	if (dev->netdev)
+		unregister_netdevice(dev->netdev);
+	return 0;
+}
+
+static void close_work(struct work_struct *work)
+{
+	struct chnl_net *dev = NULL;
+	struct list_head *list_node;
+	struct list_head *_tmp;
+
+	rtnl_lock();
+	list_for_each_safe(list_node, _tmp, &chnl_net_list) {
+		dev = list_entry(list_node, struct chnl_net, list_field);
+		if (dev->state == CAIF_SHUTDOWN)
+			dev_close(dev->netdev);
+	}
+	rtnl_unlock();
+}
+static DECLARE_WORK(close_worker, close_work);
+
+static void chnl_hold(struct cflayer *lyr)
+{
+	struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl);
+	dev_hold(priv->netdev);
+}
+
+static void chnl_put(struct cflayer *lyr)
+{
+	struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl);
+	dev_put(priv->netdev);
+}
+
+static void chnl_flowctrl_cb(struct cflayer *layr, enum caif_ctrlcmd flow,
+			     int phyid)
+{
+	struct chnl_net *priv = container_of(layr, struct chnl_net, chnl);
+	pr_debug("NET flowctrl func called flow: %s\n",
+		flow == CAIF_CTRLCMD_FLOW_ON_IND ? "ON" :
+		flow == CAIF_CTRLCMD_INIT_RSP ? "INIT" :
+		flow == CAIF_CTRLCMD_FLOW_OFF_IND ? "OFF" :
+		flow == CAIF_CTRLCMD_DEINIT_RSP ? "CLOSE/DEINIT" :
+		flow == CAIF_CTRLCMD_INIT_FAIL_RSP ? "OPEN_FAIL" :
+		flow == CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND ?
+		 "REMOTE_SHUTDOWN" : "UNKNOWN CTRL COMMAND");
+
+
+
+	switch (flow) {
+	case CAIF_CTRLCMD_FLOW_OFF_IND:
+		priv->flowenabled = false;
+		netif_stop_queue(priv->netdev);
+		break;
+	case CAIF_CTRLCMD_DEINIT_RSP:
+		priv->state = CAIF_DISCONNECTED;
+		break;
+	case CAIF_CTRLCMD_INIT_FAIL_RSP:
+		priv->state = CAIF_DISCONNECTED;
+		wake_up_interruptible(&priv->netmgmt_wq);
+		break;
+	case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
+		priv->state = CAIF_SHUTDOWN;
+		netif_tx_disable(priv->netdev);
+		schedule_work(&close_worker);
+		break;
+	case CAIF_CTRLCMD_FLOW_ON_IND:
+		priv->flowenabled = true;
+		netif_wake_queue(priv->netdev);
+		break;
+	case CAIF_CTRLCMD_INIT_RSP:
+		caif_client_register_refcnt(&priv->chnl, chnl_hold, chnl_put);
+		priv->state = CAIF_CONNECTED;
+		priv->flowenabled = true;
+		netif_wake_queue(priv->netdev);
+		wake_up_interruptible(&priv->netmgmt_wq);
+		break;
+	default:
+		break;
+	}
+}
+
+static netdev_tx_t chnl_net_start_xmit(struct sk_buff *skb,
+				       struct net_device *dev)
+{
+	struct chnl_net *priv;
+	struct cfpkt *pkt = NULL;
+	int len;
+	int result = -1;
+	/* Get our private data. */
+	priv = netdev_priv(dev);
+
+	if (skb->len > priv->netdev->mtu) {
+		pr_warn("Size of skb exceeded MTU\n");
+		kfree_skb(skb);
+		dev->stats.tx_errors++;
+		return NETDEV_TX_OK;
+	}
+
+	if (!priv->flowenabled) {
+		pr_debug("dropping packets flow off\n");
+		kfree_skb(skb);
+		dev->stats.tx_dropped++;
+		return NETDEV_TX_OK;
+	}
+
+	if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP)
+		swap(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
+
+	/* Store original SKB length. */
+	len = skb->len;
+
+	pkt = cfpkt_fromnative(CAIF_DIR_OUT, (void *) skb);
+
+	/* Send the packet down the stack. */
+	result = priv->chnl.dn->transmit(priv->chnl.dn, pkt);
+	if (result) {
+		dev->stats.tx_dropped++;
+		return NETDEV_TX_OK;
+	}
+
+	/* Update statistics. */
+	dev->stats.tx_packets++;
+	dev->stats.tx_bytes += len;
+
+	return NETDEV_TX_OK;
+}
+
+static int chnl_net_open(struct net_device *dev)
+{
+	struct chnl_net *priv = NULL;
+	int result = -1;
+	int llifindex, headroom, tailroom, mtu;
+	struct net_device *lldev;
+	ASSERT_RTNL();
+	priv = netdev_priv(dev);
+	if (!priv) {
+		pr_debug("chnl_net_open: no priv\n");
+		return -ENODEV;
+	}
+
+	if (priv->state != CAIF_CONNECTING) {
+		priv->state = CAIF_CONNECTING;
+		result = caif_connect_client(dev_net(dev), &priv->conn_req,
+						&priv->chnl, &llifindex,
+						&headroom, &tailroom);
+		if (result != 0) {
+				pr_debug("err: "
+					 "Unable to register and open device,"
+					 " Err:%d\n",
+					 result);
+				goto error;
+		}
+
+		lldev = __dev_get_by_index(dev_net(dev), llifindex);
+
+		if (lldev == NULL) {
+			pr_debug("no interface?\n");
+			result = -ENODEV;
+			goto error;
+		}
+
+		dev->needed_tailroom = tailroom + lldev->needed_tailroom;
+		dev->hard_header_len = headroom + lldev->hard_header_len +
+			lldev->needed_tailroom;
+
+		/*
+		 * MTU, head-room etc is not know before we have a
+		 * CAIF link layer device available. MTU calculation may
+		 * override initial RTNL configuration.
+		 * MTU is minimum of current mtu, link layer mtu pluss
+		 * CAIF head and tail, and PDP GPRS contexts max MTU.
+		 */
+		mtu = min_t(int, dev->mtu, lldev->mtu - (headroom + tailroom));
+		mtu = min_t(int, GPRS_PDP_MTU, mtu);
+		dev_set_mtu(dev, mtu);
+
+		if (mtu < 100) {
+			pr_warn("CAIF Interface MTU too small (%d)\n", mtu);
+			result = -ENODEV;
+			goto error;
+		}
+	}
+
+	rtnl_unlock();  /* Release RTNL lock during connect wait */
+
+	result = wait_event_interruptible_timeout(priv->netmgmt_wq,
+						priv->state != CAIF_CONNECTING,
+						CONNECT_TIMEOUT);
+
+	rtnl_lock();
+
+	if (result == -ERESTARTSYS) {
+		pr_debug("wait_event_interruptible woken by a signal\n");
+		result = -ERESTARTSYS;
+		goto error;
+	}
+
+	if (result == 0) {
+		pr_debug("connect timeout\n");
+		result = -ETIMEDOUT;
+		goto error;
+	}
+
+	if (priv->state != CAIF_CONNECTED) {
+		pr_debug("connect failed\n");
+		result = -ECONNREFUSED;
+		goto error;
+	}
+	pr_debug("CAIF Netdevice connected\n");
+	return 0;
+
+error:
+	caif_disconnect_client(dev_net(dev), &priv->chnl);
+	priv->state = CAIF_DISCONNECTED;
+	pr_debug("state disconnected\n");
+	return result;
+
+}
+
+static int chnl_net_stop(struct net_device *dev)
+{
+	struct chnl_net *priv;
+
+	ASSERT_RTNL();
+	priv = netdev_priv(dev);
+	priv->state = CAIF_DISCONNECTED;
+	caif_disconnect_client(dev_net(dev), &priv->chnl);
+	return 0;
+}
+
+static int chnl_net_init(struct net_device *dev)
+{
+	struct chnl_net *priv;
+	ASSERT_RTNL();
+	priv = netdev_priv(dev);
+	strncpy(priv->name, dev->name, sizeof(priv->name));
+	INIT_LIST_HEAD(&priv->list_field);
+	return 0;
+}
+
+static void chnl_net_uninit(struct net_device *dev)
+{
+	struct chnl_net *priv;
+	ASSERT_RTNL();
+	priv = netdev_priv(dev);
+	list_del_init(&priv->list_field);
+}
+
+static const struct net_device_ops netdev_ops = {
+	.ndo_open = chnl_net_open,
+	.ndo_stop = chnl_net_stop,
+	.ndo_init = chnl_net_init,
+	.ndo_uninit = chnl_net_uninit,
+	.ndo_start_xmit = chnl_net_start_xmit,
+};
+
+static void chnl_net_destructor(struct net_device *dev)
+{
+	struct chnl_net *priv = netdev_priv(dev);
+	caif_free_client(&priv->chnl);
+}
+
+static void ipcaif_net_setup(struct net_device *dev)
+{
+	struct chnl_net *priv;
+	dev->netdev_ops = &netdev_ops;
+	dev->needs_free_netdev = true;
+	dev->priv_destructor = chnl_net_destructor;
+	dev->flags |= IFF_NOARP;
+	dev->flags |= IFF_POINTOPOINT;
+	dev->mtu = GPRS_PDP_MTU;
+	dev->tx_queue_len = CAIF_NET_DEFAULT_QUEUE_LEN;
+
+	priv = netdev_priv(dev);
+	priv->chnl.receive = chnl_recv_cb;
+	priv->chnl.ctrlcmd = chnl_flowctrl_cb;
+	priv->netdev = dev;
+	priv->conn_req.protocol = CAIFPROTO_DATAGRAM;
+	priv->conn_req.link_selector = CAIF_LINK_HIGH_BANDW;
+	priv->conn_req.priority = CAIF_PRIO_LOW;
+	/* Insert illegal value */
+	priv->conn_req.sockaddr.u.dgm.connection_id = UNDEF_CONNID;
+	priv->flowenabled = false;
+
+	init_waitqueue_head(&priv->netmgmt_wq);
+}
+
+
+static int ipcaif_fill_info(struct sk_buff *skb, const struct net_device *dev)
+{
+	struct chnl_net *priv;
+	u8 loop;
+	priv = netdev_priv(dev);
+	if (nla_put_u32(skb, IFLA_CAIF_IPV4_CONNID,
+			priv->conn_req.sockaddr.u.dgm.connection_id) ||
+	    nla_put_u32(skb, IFLA_CAIF_IPV6_CONNID,
+			priv->conn_req.sockaddr.u.dgm.connection_id))
+		goto nla_put_failure;
+	loop = priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP;
+	if (nla_put_u8(skb, IFLA_CAIF_LOOPBACK, loop))
+		goto nla_put_failure;
+	return 0;
+nla_put_failure:
+	return -EMSGSIZE;
+
+}
+
+static void caif_netlink_parms(struct nlattr *data[],
+			       struct caif_connect_request *conn_req)
+{
+	if (!data) {
+		pr_warn("no params data found\n");
+		return;
+	}
+	if (data[IFLA_CAIF_IPV4_CONNID])
+		conn_req->sockaddr.u.dgm.connection_id =
+			nla_get_u32(data[IFLA_CAIF_IPV4_CONNID]);
+	if (data[IFLA_CAIF_IPV6_CONNID])
+		conn_req->sockaddr.u.dgm.connection_id =
+			nla_get_u32(data[IFLA_CAIF_IPV6_CONNID]);
+	if (data[IFLA_CAIF_LOOPBACK]) {
+		if (nla_get_u8(data[IFLA_CAIF_LOOPBACK]))
+			conn_req->protocol = CAIFPROTO_DATAGRAM_LOOP;
+		else
+			conn_req->protocol = CAIFPROTO_DATAGRAM;
+	}
+}
+
+static int ipcaif_newlink(struct net *src_net, struct net_device *dev,
+			  struct nlattr *tb[], struct nlattr *data[],
+			  struct netlink_ext_ack *extack)
+{
+	int ret;
+	struct chnl_net *caifdev;
+	ASSERT_RTNL();
+	caifdev = netdev_priv(dev);
+	caif_netlink_parms(data, &caifdev->conn_req);
+
+	ret = register_netdevice(dev);
+	if (ret)
+		pr_warn("device rtml registration failed\n");
+	else
+		list_add(&caifdev->list_field, &chnl_net_list);
+
+	/* Use ifindex as connection id, and use loopback channel default. */
+	if (caifdev->conn_req.sockaddr.u.dgm.connection_id == UNDEF_CONNID) {
+		caifdev->conn_req.sockaddr.u.dgm.connection_id = dev->ifindex;
+		caifdev->conn_req.protocol = CAIFPROTO_DATAGRAM_LOOP;
+	}
+	return ret;
+}
+
+static int ipcaif_changelink(struct net_device *dev, struct nlattr *tb[],
+			     struct nlattr *data[],
+			     struct netlink_ext_ack *extack)
+{
+	struct chnl_net *caifdev;
+	ASSERT_RTNL();
+	caifdev = netdev_priv(dev);
+	caif_netlink_parms(data, &caifdev->conn_req);
+	netdev_state_change(dev);
+	return 0;
+}
+
+static size_t ipcaif_get_size(const struct net_device *dev)
+{
+	return
+		/* IFLA_CAIF_IPV4_CONNID */
+		nla_total_size(4) +
+		/* IFLA_CAIF_IPV6_CONNID */
+		nla_total_size(4) +
+		/* IFLA_CAIF_LOOPBACK */
+		nla_total_size(2) +
+		0;
+}
+
+static const struct nla_policy ipcaif_policy[IFLA_CAIF_MAX + 1] = {
+	[IFLA_CAIF_IPV4_CONNID]	      = { .type = NLA_U32 },
+	[IFLA_CAIF_IPV6_CONNID]	      = { .type = NLA_U32 },
+	[IFLA_CAIF_LOOPBACK]	      = { .type = NLA_U8 }
+};
+
+
+static struct rtnl_link_ops ipcaif_link_ops __read_mostly = {
+	.kind		= "caif",
+	.priv_size	= sizeof(struct chnl_net),
+	.setup		= ipcaif_net_setup,
+	.maxtype	= IFLA_CAIF_MAX,
+	.policy		= ipcaif_policy,
+	.newlink	= ipcaif_newlink,
+	.changelink	= ipcaif_changelink,
+	.get_size	= ipcaif_get_size,
+	.fill_info	= ipcaif_fill_info,
+
+};
+
+static int __init chnl_init_module(void)
+{
+	return rtnl_link_register(&ipcaif_link_ops);
+}
+
+static void __exit chnl_exit_module(void)
+{
+	struct chnl_net *dev = NULL;
+	struct list_head *list_node;
+	struct list_head *_tmp;
+	rtnl_link_unregister(&ipcaif_link_ops);
+	rtnl_lock();
+	list_for_each_safe(list_node, _tmp, &chnl_net_list) {
+		dev = list_entry(list_node, struct chnl_net, list_field);
+		list_del_init(list_node);
+		delete_device(dev);
+	}
+	rtnl_unlock();
+}
+
+module_init(chnl_init_module);
+module_exit(chnl_exit_module);