19 files changed, 5621 insertions, 0 deletions

diff --git a/net/caif/Kconfig b/net/caif/Kconfig
new file mode 100644
index 00000000000..529750da962
--- /dev/null
+++ b/net/caif/Kconfig
@@ -0,0 +1,42 @@
+#
+# 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 modules. You will also need to say yes 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.
diff --git a/net/caif/Makefile b/net/caif/Makefile
new file mode 100644
index 00000000000..f87481fb0e6
--- /dev/null
+++ b/net/caif/Makefile
@@ -0,0 +1,16 @@
+ifeq ($(CONFIG_CAIF_DEBUG),y)
+EXTRA_CFLAGS += -DDEBUG
+endif
+
+caif-objs := caif_dev.o \
+	cfcnfg.o cfmuxl.o cfctrl.o  \
+	cffrml.o cfveil.o cfdbgl.o\
+	cfserl.o cfdgml.o  \
+	cfrfml.o cfvidl.o cfutill.o \
+	cfsrvl.o cfpkt_skbuff.o caif_config_util.o
+
+obj-$(CONFIG_CAIF) += caif.o
+obj-$(CONFIG_CAIF_NETDEV) += chnl_net.o
+obj-$(CONFIG_CAIF) += caif_socket.o
+
+export-objs := caif.o
diff --git a/net/caif/caif_config_util.c b/net/caif/caif_config_util.c
new file mode 100644
index 00000000000..76ae68303d3
--- /dev/null
+++ b/net/caif/caif_config_util.c
@@ -0,0 +1,92 @@
+/*
+ * Copyright (C) ST-Ericsson AB 2010
+ * Author:	Sjur Brendeland sjur.brandeland@stericsson.com
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <net/caif/cfctrl.h>
+#include <net/caif/cfcnfg.h>
+#include <net/caif/caif_dev.h>
+
+int 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;
+	memset(l, 0, sizeof(*l));
+	l->priority = s->priority;
+
+	if (s->link_name[0] != '\0')
+		l->phyid = cfcnfg_get_named(cnfg, s->link_name);
+	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;
+		if (s->sockaddr.u.at.type == CAIF_ATTYPE_PLAIN)
+			l->chtype = 0x02;
+		else
+			l->chtype = s->sockaddr.u.at.type;
+		l->endpoint = 0x00;
+		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;
+		strncpy(l->u.rfm.volume, s->sockaddr.u.rfm.volume,
+			sizeof(l->u.rfm.volume)-1);
+		l->u.rfm.volume[sizeof(l->u.rfm.volume)-1] = 0;
+		break;
+	case CAIFPROTO_UTIL:
+		l->linktype = CFCTRL_SRV_UTIL;
+		l->endpoint = 0x00;
+		l->chtype = 0x00;
+		strncpy(l->u.utility.name, s->sockaddr.u.util.service,
+			sizeof(l->u.utility.name)-1);
+		l->u.utility.name[sizeof(l->u.utility.name)-1] = 0;
+		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;
+}
diff --git a/net/caif/caif_dev.c b/net/caif/caif_dev.c
new file mode 100644
index 00000000000..0b586e9d137
--- /dev/null
+++ b/net/caif/caif_dev.c
@@ -0,0 +1,421 @@
+/*
+ * CAIF Interface registration.
+ * Copyright (C) ST-Ericsson AB 2010
+ * Author:	Sjur Brendeland/sjur.brandeland@stericsson.com
+ * License terms: GNU General Public License (GPL) version 2
+ *
+ * Borrowed heavily from file: pn_dev.c. Thanks to
+ *  Remi Denis-Courmont <remi.denis-courmont@nokia.com>
+ *  and Sakari Ailus <sakari.ailus@nokia.com>
+ */
+
+#include <linux/version.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/if_arp.h>
+#include <linux/net.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/sched.h>
+#include <linux/wait.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_dev.h>
+#include <net/caif/caif_layer.h>
+#include <net/caif/cfpkt.h>
+#include <net/caif/cfcnfg.h>
+
+MODULE_LICENSE("GPL");
+#define TIMEOUT (HZ*5)
+
+/* Used for local tracking of the CAIF net devices */
+struct caif_device_entry {
+	struct cflayer layer;
+	struct list_head list;
+	atomic_t in_use;
+	atomic_t state;
+	u16 phyid;
+	struct net_device *netdev;
+	wait_queue_head_t event;
+};
+
+struct caif_device_entry_list {
+	struct list_head list;
+	/* Protects simulanous deletes in list */
+	spinlock_t lock;
+};
+
+struct caif_net {
+	struct caif_device_entry_list caifdevs;
+};
+
+static int caif_net_id;
+static struct cfcnfg *cfg;
+
+static struct caif_device_entry_list *caif_device_list(struct net *net)
+{
+	struct caif_net *caifn;
+	BUG_ON(!net);
+	caifn = net_generic(net, caif_net_id);
+	BUG_ON(!caifn);
+	return &caifn->caifdevs;
+}
+
+/* Allocate new CAIF device. */
+static struct caif_device_entry *caif_device_alloc(struct net_device *dev)
+{
+	struct caif_device_entry_list *caifdevs;
+	struct caif_device_entry *caifd;
+	caifdevs = caif_device_list(dev_net(dev));
+	BUG_ON(!caifdevs);
+	caifd = kzalloc(sizeof(*caifd), GFP_ATOMIC);
+	if (!caifd)
+		return NULL;
+	caifd->netdev = dev;
+	list_add(&caifd->list, &caifdevs->list);
+	init_waitqueue_head(&caifd->event);
+	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;
+	BUG_ON(!caifdevs);
+	list_for_each_entry(caifd, &caifdevs->list, list) {
+		if (caifd->netdev == dev)
+			return caifd;
+	}
+	return NULL;
+}
+
+static void caif_device_destroy(struct net_device *dev)
+{
+	struct caif_device_entry_list *caifdevs =
+	    caif_device_list(dev_net(dev));
+	struct caif_device_entry *caifd;
+	ASSERT_RTNL();
+	if (dev->type != ARPHRD_CAIF)
+		return;
+
+	spin_lock_bh(&caifdevs->lock);
+	caifd = caif_get(dev);
+	if (caifd == NULL) {
+		spin_unlock_bh(&caifdevs->lock);
+		return;
+	}
+
+	list_del(&caifd->list);
+	spin_unlock_bh(&caifdevs->lock);
+
+	kfree(caifd);
+}
+
+static int transmit(struct cflayer *layer, struct cfpkt *pkt)
+{
+	struct caif_device_entry *caifd =
+	    container_of(layer, struct caif_device_entry, layer);
+	struct sk_buff *skb, *skb2;
+	int ret = -EINVAL;
+	skb = cfpkt_tonative(pkt);
+	skb->dev = caifd->netdev;
+	/*
+	 * Don't allow SKB to be destroyed upon error, but signal resend
+	 * notification to clients. We can't rely on the return value as
+	 * congestion (NET_XMIT_CN) sometimes drops the packet, sometimes don't.
+	 */
+	if (netif_queue_stopped(caifd->netdev))
+		return -EAGAIN;
+	skb2 = skb_get(skb);
+
+	ret = dev_queue_xmit(skb2);
+
+	if (!ret)
+		kfree_skb(skb);
+	else
+		return -EAGAIN;
+
+	return 0;
+}
+
+static int modemcmd(struct cflayer *layr, enum caif_modemcmd ctrl)
+{
+	struct caif_device_entry *caifd;
+	struct caif_dev_common *caifdev;
+	caifd = container_of(layr, struct caif_device_entry, layer);
+	caifdev = netdev_priv(caifd->netdev);
+	if (ctrl == _CAIF_MODEMCMD_PHYIF_USEFULL) {
+		atomic_set(&caifd->in_use, 1);
+		wake_up_interruptible(&caifd->event);
+
+	} else if (ctrl == _CAIF_MODEMCMD_PHYIF_USELESS) {
+		atomic_set(&caifd->in_use, 0);
+		wake_up_interruptible(&caifd->event);
+	}
+	return 0;
+}
+
+/*
+ * Stuff received packets to associated sockets.
+ * 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 net *net;
+	struct cfpkt *pkt;
+	struct caif_device_entry *caifd;
+	net = dev_net(dev);
+	pkt = cfpkt_fromnative(CAIF_DIR_IN, skb);
+	caifd = caif_get(dev);
+	if (!caifd || !caifd->layer.up || !caifd->layer.up->ctrlcmd)
+		return NET_RX_DROP;
+
+	if (caifd->layer.up->receive(caifd->layer.up, pkt))
+		return NET_RX_DROP;
+
+	return 0;
+}
+
+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 = caif_get(dev);
+	if (!caifd || !caifd->layer.up || !caifd->layer.up->ctrlcmd)
+		return;
+
+	caifd->layer.up->ctrlcmd(caifd->layer.up,
+				 on ?
+				 _CAIF_CTRLCMD_PHYIF_FLOW_ON_IND :
+				 _CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND,
+				 caifd->layer.id);
+}
+
+/* notify Caif of device events */
+static int caif_device_notify(struct notifier_block *me, unsigned long what,
+			      void *arg)
+{
+	struct net_device *dev = arg;
+	struct caif_device_entry *caifd = NULL;
+	struct caif_dev_common *caifdev;
+	enum cfcnfg_phy_preference pref;
+	int res = -EINVAL;
+	enum cfcnfg_phy_type phy_type;
+
+	if (dev->type != ARPHRD_CAIF)
+		return 0;
+
+	switch (what) {
+	case NETDEV_REGISTER:
+		pr_info("CAIF: %s():register %s\n", __func__, dev->name);
+		caifd = caif_device_alloc(dev);
+		if (caifd == NULL)
+			break;
+		caifdev = netdev_priv(dev);
+		caifdev->flowctrl = dev_flowctrl;
+		atomic_set(&caifd->state, what);
+		res = 0;
+		break;
+
+	case NETDEV_UP:
+		pr_info("CAIF: %s(): up %s\n", __func__, dev->name);
+		caifd = caif_get(dev);
+		if (caifd == NULL)
+			break;
+		caifdev = netdev_priv(dev);
+		if (atomic_read(&caifd->state) == NETDEV_UP) {
+			pr_info("CAIF: %s():%s already up\n",
+				__func__, dev->name);
+			break;
+		}
+		atomic_set(&caifd->state, what);
+		caifd->layer.transmit = transmit;
+		caifd->layer.modemcmd = modemcmd;
+
+		if (caifdev->use_frag)
+			phy_type = CFPHYTYPE_FRAG;
+		else
+			phy_type = CFPHYTYPE_CAIF;
+
+		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;
+		}
+		dev_hold(dev);
+		cfcnfg_add_phy_layer(get_caif_conf(),
+				     phy_type,
+				     dev,
+				     &caifd->layer,
+				     &caifd->phyid,
+				     pref,
+				     caifdev->use_fcs,
+				     caifdev->use_stx);
+		strncpy(caifd->layer.name, dev->name,
+			sizeof(caifd->layer.name) - 1);
+		caifd->layer.name[sizeof(caifd->layer.name) - 1] = 0;
+		break;
+
+	case NETDEV_GOING_DOWN:
+		caifd = caif_get(dev);
+		if (caifd == NULL)
+			break;
+		pr_info("CAIF: %s():going down %s\n", __func__, dev->name);
+
+		if (atomic_read(&caifd->state) == NETDEV_GOING_DOWN ||
+			atomic_read(&caifd->state) == NETDEV_DOWN)
+			break;
+
+		atomic_set(&caifd->state, what);
+		if (!caifd || !caifd->layer.up || !caifd->layer.up->ctrlcmd)
+			return -EINVAL;
+		caifd->layer.up->ctrlcmd(caifd->layer.up,
+					 _CAIF_CTRLCMD_PHYIF_DOWN_IND,
+					 caifd->layer.id);
+		might_sleep();
+		res = wait_event_interruptible_timeout(caifd->event,
+					atomic_read(&caifd->in_use) == 0,
+					TIMEOUT);
+		break;
+
+	case NETDEV_DOWN:
+		caifd = caif_get(dev);
+		if (caifd == NULL)
+			break;
+		pr_info("CAIF: %s(): down %s\n", __func__, dev->name);
+		if (atomic_read(&caifd->in_use))
+			pr_warning("CAIF: %s(): "
+				   "Unregistering an active CAIF device: %s\n",
+				   __func__, dev->name);
+		cfcnfg_del_phy_layer(get_caif_conf(), &caifd->layer);
+		dev_put(dev);
+		atomic_set(&caifd->state, what);
+		break;
+
+	case NETDEV_UNREGISTER:
+		caifd = caif_get(dev);
+		pr_info("CAIF: %s(): unregister %s\n", __func__, dev->name);
+		atomic_set(&caifd->state, what);
+		caif_device_destroy(dev);
+		break;
+	}
+	return 0;
+}
+
+static struct notifier_block caif_device_notifier = {
+	.notifier_call = caif_device_notify,
+	.priority = 0,
+};
+
+
+struct cfcnfg *get_caif_conf(void)
+{
+	return cfg;
+}
+EXPORT_SYMBOL(get_caif_conf);
+
+int caif_connect_client(struct caif_connect_request *conn_req,
+			struct cflayer *client_layer, int *ifindex,
+			int *headroom, int *tailroom)
+{
+	struct cfctrl_link_param param;
+	int ret;
+	ret = connect_req_to_link_param(get_caif_conf(), conn_req, &param);
+	if (ret)
+		return ret;
+	/* Hook up the adaptation layer. */
+	return cfcnfg_add_adaptation_layer(get_caif_conf(), &param,
+					client_layer, ifindex,
+					headroom, tailroom);
+}
+EXPORT_SYMBOL(caif_connect_client);
+
+int caif_disconnect_client(struct cflayer *adap_layer)
+{
+       return cfcnfg_disconn_adapt_layer(get_caif_conf(), adap_layer);
+}
+EXPORT_SYMBOL(caif_disconnect_client);
+
+void caif_release_client(struct cflayer *adap_layer)
+{
+       cfcnfg_release_adap_layer(adap_layer);
+}
+EXPORT_SYMBOL(caif_release_client);
+
+/* 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);
+	spin_lock_init(&caifn->caifdevs.lock);
+	return 0;
+}
+
+static void caif_exit_net(struct net *net)
+{
+	struct net_device *dev;
+	int res;
+	rtnl_lock();
+	for_each_netdev(net, dev) {
+		if (dev->type != ARPHRD_CAIF)
+			continue;
+		res = dev_close(dev);
+		caif_device_destroy(dev);
+	}
+	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;
+	cfg = cfcnfg_create();
+	if (!cfg) {
+		pr_warning("CAIF: %s(): can't create cfcnfg.\n", __func__);
+		goto err_cfcnfg_create_failed;
+	}
+	result = register_pernet_device(&caif_net_ops);
+
+	if (result) {
+		kfree(cfg);
+		cfg = NULL;
+		return result;
+	}
+	dev_add_pack(&caif_packet_type);
+	register_netdevice_notifier(&caif_device_notifier);
+
+	return result;
+err_cfcnfg_create_failed:
+	return -ENODEV;
+}
+
+static void __exit caif_device_exit(void)
+{
+	dev_remove_pack(&caif_packet_type);
+	unregister_pernet_device(&caif_net_ops);
+	unregister_netdevice_notifier(&caif_device_notifier);
+	cfcnfg_remove(cfg);
+}
+
+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 00000000000..4bf28f25f36
--- /dev/null
+++ b/net/caif/caif_socket.c
@@ -0,0 +1,1253 @@
+/*
+ * Copyright (C) ST-Ericsson AB 2010
+ * Author:	Sjur Brendeland sjur.brandeland@stericsson.com
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/sched.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/mutex.h>
+#include <linux/debugfs.h>
+#include <linux/caif/caif_socket.h>
+#include <asm/atomic.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);
+
+#define CAIF_DEF_SNDBUF (4096*10)
+#define CAIF_DEF_RCVBUF (4096*100)
+
+/*
+ * 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
+
+static struct dentry *debugfsdir;
+
+#ifdef CONFIG_DEBUG_FS
+struct debug_fs_counter {
+	atomic_t caif_nr_socks;
+	atomic_t num_connect_req;
+	atomic_t num_connect_resp;
+	atomic_t num_connect_fail_resp;
+	atomic_t num_disconnect;
+	atomic_t num_remote_shutdown_ind;
+	atomic_t num_tx_flow_off_ind;
+	atomic_t num_tx_flow_on_ind;
+	atomic_t num_rx_flow_off;
+	atomic_t num_rx_flow_on;
+};
+static struct debug_fs_counter cnt;
+#define	dbfs_atomic_inc(v) atomic_inc(v)
+#define	dbfs_atomic_dec(v) atomic_dec(v)
+#else
+#define	dbfs_atomic_inc(v)
+#define	dbfs_atomic_dec(v)
+#endif
+
+struct caifsock {
+	struct sock sk; /* must be first member */
+	struct cflayer layer;
+	char name[CAIF_LAYER_NAME_SZ]; /* Used for debugging */
+	u32 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,
+			(void *) &cf_sk->flow_state);
+}
+
+static int tx_flow_is_on(struct caifsock *cf_sk)
+{
+	return test_bit(TX_FLOW_ON_BIT,
+			(void *) &cf_sk->flow_state);
+}
+
+static void set_rx_flow_off(struct caifsock *cf_sk)
+{
+	 clear_bit(RX_FLOW_ON_BIT,
+		 (void *) &cf_sk->flow_state);
+}
+
+static void set_rx_flow_on(struct caifsock *cf_sk)
+{
+	 set_bit(RX_FLOW_ON_BIT,
+			(void *) &cf_sk->flow_state);
+}
+
+static void set_tx_flow_off(struct caifsock *cf_sk)
+{
+	 clear_bit(TX_FLOW_ON_BIT,
+		(void *) &cf_sk->flow_state);
+}
+
+static void set_tx_flow_on(struct caifsock *cf_sk)
+{
+	 set_bit(TX_FLOW_ON_BIT,
+		(void *) &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 int caif_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
+{
+	int err;
+	int skb_len;
+	unsigned long flags;
+	struct sk_buff_head *list = &sk->sk_receive_queue;
+	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
+
+	if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
+		(unsigned)sk->sk_rcvbuf && rx_flow_is_on(cf_sk)) {
+		trace_printk("CAIF: %s():"
+			" sending flow OFF (queue len = %d %d)\n",
+			__func__,
+			atomic_read(&cf_sk->sk.sk_rmem_alloc),
+			sk_rcvbuf_lowwater(cf_sk));
+		set_rx_flow_off(cf_sk);
+		dbfs_atomic_inc(&cnt.num_rx_flow_off);
+		caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
+	}
+
+	err = sk_filter(sk, skb);
+	if (err)
+		return err;
+	if (!sk_rmem_schedule(sk, skb->truesize) && rx_flow_is_on(cf_sk)) {
+		set_rx_flow_off(cf_sk);
+		trace_printk("CAIF: %s():"
+			" sending flow OFF due to rmem_schedule\n",
+			__func__);
+		dbfs_atomic_inc(&cnt.num_rx_flow_off);
+		caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
+	}
+	skb->dev = NULL;
+	skb_set_owner_r(skb, sk);
+	/* Cache the SKB length before we tack it onto the receive
+	 * queue. Once it is added it no longer belongs to us and
+	 * may be freed by other threads of control pulling packets
+	 * from the queue.
+	 */
+	skb_len = skb->len;
+	spin_lock_irqsave(&list->lock, flags);
+	if (!sock_flag(sk, SOCK_DEAD))
+		__skb_queue_tail(list, skb);
+	spin_unlock_irqrestore(&list->lock, flags);
+
+	if (!sock_flag(sk, SOCK_DEAD))
+		sk->sk_data_ready(sk, skb_len);
+	else
+		kfree_skb(skb);
+	return 0;
+}
+
+/* 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)) {
+		cfpkt_destroy(pkt);
+		return 0;
+	}
+	caif_queue_rcv_skb(&cf_sk->sk, skb);
+	return 0;
+}
+
+/* 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 */
+		dbfs_atomic_inc(&cnt.num_tx_flow_on_ind);
+		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 */
+		dbfs_atomic_inc(&cnt.num_tx_flow_off_ind);
+		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 */
+		dbfs_atomic_inc(&cnt.num_connect_resp);
+		cf_sk->sk.sk_state = CAIF_CONNECTED;
+		set_tx_flow_on(cf_sk);
+		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);
+		cfcnfg_release_adap_layer(&cf_sk->layer);
+		break;
+
+	case CAIF_CTRLCMD_INIT_FAIL_RSP:
+		/* Connect request failed */
+		dbfs_atomic_inc(&cnt.num_connect_fail_resp);
+		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. */
+		dbfs_atomic_inc(&cnt.num_remote_shutdown_ind);
+		cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
+		cf_sk->sk.sk_err = ECONNRESET;
+		set_rx_flow_on(cf_sk);
+		cf_sk->sk.sk_error_report(&cf_sk->sk);
+		break;
+
+	default:
+		pr_debug("CAIF: %s(): Unexpected flow command %d\n",
+				__func__, 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)) {
+			dbfs_atomic_inc(&cnt.num_rx_flow_on);
+			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 kiocb *iocb, 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 (m->msg_flags&MSG_OOB)
+		goto read_error;
+
+	skb = skb_recv_datagram(sk, flags, 0 , &ret);
+	if (!skb)
+		goto read_error;
+	copylen = skb->len;
+	if (len < copylen) {
+		m->msg_flags |= MSG_TRUNC;
+		copylen = len;
+	}
+
+	ret = skb_copy_datagram_iovec(skb, 0, m->msg_iov, 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;
+
+		set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
+		release_sock(sk);
+		timeo = schedule_timeout(timeo);
+		lock_sock(sk);
+		clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
+	}
+
+	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 kiocb *iocb, 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;
+
+	msg->msg_namelen = 0;
+
+	/*
+	 * 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);
+		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_toiovec(msg->msg_iov, 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
+