M7350v1_en_gpl

kernel/drivers/connector/Kconfig

@@ -0,0 +1,22 @@
+
+menuconfig CONNECTOR
+	tristate "Connector - unified userspace <-> kernelspace linker"
+	depends on NET
+	---help---
+	  This is unified userspace <-> kernelspace connector working on top
+	  of the netlink socket protocol.
+
+	  Connector support can also be built as a module.  If so, the module
+	  will be called cn.
+
+if CONNECTOR
+
+config PROC_EVENTS
+	boolean "Report process events to userspace"
+	depends on CONNECTOR=y
+	default y
+	---help---
+	  Provide a connector that reports process events to userspace. Send
+	  events such as fork, exec, id change (uid, gid, suid, etc), and exit.
+
+endif # CONNECTOR

kernel/drivers/connector/Makefile

@@ -0,0 +1,4 @@
+obj-$(CONFIG_CONNECTOR)		+= cn.o
+obj-$(CONFIG_PROC_EVENTS)	+= cn_proc.o
+
+cn-y				+= cn_queue.o connector.o

kernel/drivers/connector/cn_proc.c

@@ -0,0 +1,338 @@
+/*
+ * cn_proc.c - process events connector
+ *
+ * Copyright (C) Matt Helsley, IBM Corp. 2005
+ * Based on cn_fork.c by Guillaume Thouvenin <guillaume.thouvenin@bull.net>
+ * Original copyright notice follows:
+ * Copyright (C) 2005 BULL SA.
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/ktime.h>
+#include <linux/init.h>
+#include <linux/connector.h>
+#include <linux/gfp.h>
+#include <linux/ptrace.h>
+#include <linux/atomic.h>
+
+#include <asm/unaligned.h>
+
+#include <linux/cn_proc.h>
+
+#define CN_PROC_MSG_SIZE (sizeof(struct cn_msg) + sizeof(struct proc_event))
+
+static atomic_t proc_event_num_listeners = ATOMIC_INIT(0);
+static struct cb_id cn_proc_event_id = { CN_IDX_PROC, CN_VAL_PROC };
+
+/* proc_event_counts is used as the sequence number of the netlink message */
+static DEFINE_PER_CPU(__u32, proc_event_counts) = { 0 };
+
+static inline void get_seq(__u32 *ts, int *cpu)
+{
+	preempt_disable();
+	*ts = __this_cpu_inc_return(proc_event_counts) -1;
+	*cpu = smp_processor_id();
+	preempt_enable();
+}
+
+void proc_fork_connector(struct task_struct *task)
+{
+	struct cn_msg *msg;
+	struct proc_event *ev;
+	__u8 buffer[CN_PROC_MSG_SIZE];
+	struct timespec ts;
+	struct task_struct *parent;
+
+	if (atomic_read(&proc_event_num_listeners) < 1)
+		return;
+
+	msg = (struct cn_msg*)buffer;
+	ev = (struct proc_event*)msg->data;
+	get_seq(&msg->seq, &ev->cpu);
+	ktime_get_ts(&ts); /* get high res monotonic timestamp */
+	put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
+	ev->what = PROC_EVENT_FORK;
+	rcu_read_lock();
+	parent = rcu_dereference(task->real_parent);
+	ev->event_data.fork.parent_pid = parent->pid;
+	ev->event_data.fork.parent_tgid = parent->tgid;
+	rcu_read_unlock();
+	ev->event_data.fork.child_pid = task->pid;
+	ev->event_data.fork.child_tgid = task->tgid;
+
+	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
+	msg->ack = 0; /* not used */
+	msg->len = sizeof(*ev);
+	/*  If cn_netlink_send() failed, the data is not sent */
+	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
+}
+
+void proc_exec_connector(struct task_struct *task)
+{
+	struct cn_msg *msg;
+	struct proc_event *ev;
+	struct timespec ts;
+	__u8 buffer[CN_PROC_MSG_SIZE];
+
+	if (atomic_read(&proc_event_num_listeners) < 1)
+		return;
+
+	msg = (struct cn_msg*)buffer;
+	ev = (struct proc_event*)msg->data;
+	get_seq(&msg->seq, &ev->cpu);
+	ktime_get_ts(&ts); /* get high res monotonic timestamp */
+	put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
+	ev->what = PROC_EVENT_EXEC;
+	ev->event_data.exec.process_pid = task->pid;
+	ev->event_data.exec.process_tgid = task->tgid;
+
+	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
+	msg->ack = 0; /* not used */
+	msg->len = sizeof(*ev);
+	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
+}
+
+void proc_id_connector(struct task_struct *task, int which_id)
+{
+	struct cn_msg *msg;
+	struct proc_event *ev;
+	__u8 buffer[CN_PROC_MSG_SIZE];
+	struct timespec ts;
+	const struct cred *cred;
+
+	if (atomic_read(&proc_event_num_listeners) < 1)
+		return;
+
+	msg = (struct cn_msg*)buffer;
+	ev = (struct proc_event*)msg->data;
+	ev->what = which_id;
+	ev->event_data.id.process_pid = task->pid;
+	ev->event_data.id.process_tgid = task->tgid;
+	rcu_read_lock();
+	cred = __task_cred(task);
+	if (which_id == PROC_EVENT_UID) {
+		ev->event_data.id.r.ruid = cred->uid;
+		ev->event_data.id.e.euid = cred->euid;
+	} else if (which_id == PROC_EVENT_GID) {
+		ev->event_data.id.r.rgid = cred->gid;
+		ev->event_data.id.e.egid = cred->egid;
+	} else {
+		rcu_read_unlock();
+	     	return;
+	}
+	rcu_read_unlock();
+	get_seq(&msg->seq, &ev->cpu);
+	ktime_get_ts(&ts); /* get high res monotonic timestamp */
+	put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
+
+	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
+	msg->ack = 0; /* not used */
+	msg->len = sizeof(*ev);
+	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
+}
+
+void proc_sid_connector(struct task_struct *task)
+{
+	struct cn_msg *msg;
+	struct proc_event *ev;
+	struct timespec ts;
+	__u8 buffer[CN_PROC_MSG_SIZE];
+
+	if (atomic_read(&proc_event_num_listeners) < 1)
+		return;
+
+	msg = (struct cn_msg *)buffer;
+	ev = (struct proc_event *)msg->data;
+	get_seq(&msg->seq, &ev->cpu);
+	ktime_get_ts(&ts); /* get high res monotonic timestamp */
+	put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
+	ev->what = PROC_EVENT_SID;
+	ev->event_data.sid.process_pid = task->pid;
+	ev->event_data.sid.process_tgid = task->tgid;
+
+	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
+	msg->ack = 0; /* not used */
+	msg->len = sizeof(*ev);
+	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
+}
+
+void proc_ptrace_connector(struct task_struct *task, int ptrace_id)
+{
+	struct cn_msg *msg;
+	struct proc_event *ev;
+	struct timespec ts;
+	__u8 buffer[CN_PROC_MSG_SIZE];
+
+	if (atomic_read(&proc_event_num_listeners) < 1)
+		return;
+
+	msg = (struct cn_msg *)buffer;
+	ev = (struct proc_event *)msg->data;
+	get_seq(&msg->seq, &ev->cpu);
+	ktime_get_ts(&ts); /* get high res monotonic timestamp */
+	put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
+	ev->what = PROC_EVENT_PTRACE;
+	ev->event_data.ptrace.process_pid  = task->pid;
+	ev->event_data.ptrace.process_tgid = task->tgid;
+	if (ptrace_id == PTRACE_ATTACH) {
+		ev->event_data.ptrace.tracer_pid  = current->pid;
+		ev->event_data.ptrace.tracer_tgid = current->tgid;
+	} else if (ptrace_id == PTRACE_DETACH) {
+		ev->event_data.ptrace.tracer_pid  = 0;
+		ev->event_data.ptrace.tracer_tgid = 0;
+	} else
+		return;
+
+	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
+	msg->ack = 0; /* not used */
+	msg->len = sizeof(*ev);
+	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
+}
+
+void proc_comm_connector(struct task_struct *task)
+{
+	struct cn_msg *msg;
+	struct proc_event *ev;
+	struct timespec ts;
+	__u8 buffer[CN_PROC_MSG_SIZE];
+
+	if (atomic_read(&proc_event_num_listeners) < 1)
+		return;
+
+	msg = (struct cn_msg *)buffer;
+	ev = (struct proc_event *)msg->data;
+	get_seq(&msg->seq, &ev->cpu);
+	ktime_get_ts(&ts); /* get high res monotonic timestamp */
+	put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
+	ev->what = PROC_EVENT_COMM;
+	ev->event_data.comm.process_pid  = task->pid;
+	ev->event_data.comm.process_tgid = task->tgid;
+	get_task_comm(ev->event_data.comm.comm, task);
+
+	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
+	msg->ack = 0; /* not used */
+	msg->len = sizeof(*ev);
+	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
+}
+
+void proc_exit_connector(struct task_struct *task)
+{
+	struct cn_msg *msg;
+	struct proc_event *ev;
+	__u8 buffer[CN_PROC_MSG_SIZE];
+	struct timespec ts;
+
+	if (atomic_read(&proc_event_num_listeners) < 1)
+		return;
+
+	msg = (struct cn_msg*)buffer;
+	ev = (struct proc_event*)msg->data;
+	get_seq(&msg->seq, &ev->cpu);
+	ktime_get_ts(&ts); /* get high res monotonic timestamp */
+	put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
+	ev->what = PROC_EVENT_EXIT;
+	ev->event_data.exit.process_pid = task->pid;
+	ev->event_data.exit.process_tgid = task->tgid;
+	ev->event_data.exit.exit_code = task->exit_code;
+	ev->event_data.exit.exit_signal = task->exit_signal;
+
+	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
+	msg->ack = 0; /* not used */
+	msg->len = sizeof(*ev);
+	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
+}
+
+/*
+ * Send an acknowledgement message to userspace
+ *
+ * Use 0 for success, EFOO otherwise.
+ * Note: this is the negative of conventional kernel error
+ * values because it's not being returned via syscall return
+ * mechanisms.
+ */
+static void cn_proc_ack(int err, int rcvd_seq, int rcvd_ack)
+{
+	struct cn_msg *msg;
+	struct proc_event *ev;
+	__u8 buffer[CN_PROC_MSG_SIZE];
+	struct timespec ts;
+
+	if (atomic_read(&proc_event_num_listeners) < 1)
+		return;
+
+	msg = (struct cn_msg*)buffer;
+	ev = (struct proc_event*)msg->data;
+	msg->seq = rcvd_seq;
+	ktime_get_ts(&ts); /* get high res monotonic timestamp */
+	put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
+	ev->cpu = -1;
+	ev->what = PROC_EVENT_NONE;
+	ev->event_data.ack.err = err;
+	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
+	msg->ack = rcvd_ack + 1;
+	msg->len = sizeof(*ev);
+	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
+}
+
+/**
+ * cn_proc_mcast_ctl
+ * @data: message sent from userspace via the connector
+ */
+static void cn_proc_mcast_ctl(struct cn_msg *msg,
+			      struct netlink_skb_parms *nsp)
+{
+	enum proc_cn_mcast_op *mc_op = NULL;
+	int err = 0;
+
+	if (msg->len != sizeof(*mc_op))
+		return;
+
+	mc_op = (enum proc_cn_mcast_op*)msg->data;
+	switch (*mc_op) {
+	case PROC_CN_MCAST_LISTEN:
+		atomic_inc(&proc_event_num_listeners);
+		break;
+	case PROC_CN_MCAST_IGNORE:
+		atomic_dec(&proc_event_num_listeners);
+		break;
+	default:
+		err = EINVAL;
+		break;
+	}
+	cn_proc_ack(err, msg->seq, msg->ack);
+}
+
+/*
+ * cn_proc_init - initialization entry point
+ *
+ * Adds the connector callback to the connector driver.
+ */
+static int __init cn_proc_init(void)
+{
+	int err;
+
+	if ((err = cn_add_callback(&cn_proc_event_id, "cn_proc",
+	 			   &cn_proc_mcast_ctl))) {
+		printk(KERN_WARNING "cn_proc failed to register\n");
+		return err;
+	}
+	return 0;
+}
+
+module_init(cn_proc_init);

kernel/drivers/connector/cn_queue.c

@@ -0,0 +1,159 @@
+/*
+ * 	cn_queue.c
+ *
+ * 2004+ Copyright (c) Evgeniy Polyakov <zbr@ioremap.net>
+ * All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/list.h>
+#include <linux/workqueue.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/skbuff.h>
+#include <linux/suspend.h>
+#include <linux/connector.h>
+#include <linux/delay.h>
+
+static struct cn_callback_entry *
+cn_queue_alloc_callback_entry(struct cn_queue_dev *dev, const char *name,
+			      struct cb_id *id,
+			      void (*callback)(struct cn_msg *, struct netlink_skb_parms *))
+{
+	struct cn_callback_entry *cbq;
+
+	cbq = kzalloc(sizeof(*cbq), GFP_KERNEL);
+	if (!cbq) {
+		printk(KERN_ERR "Failed to create new callback queue.\n");
+		return NULL;
+	}
+
+	atomic_set(&cbq->refcnt, 1);
+
+	atomic_inc(&dev->refcnt);
+	cbq->pdev = dev;
+
+	snprintf(cbq->id.name, sizeof(cbq->id.name), "%s", name);
+	memcpy(&cbq->id.id, id, sizeof(struct cb_id));
+	cbq->callback = callback;
+	return cbq;
+}
+
+void cn_queue_release_callback(struct cn_callback_entry *cbq)
+{
+	if (!atomic_dec_and_test(&cbq->refcnt))
+		return;
+
+	atomic_dec(&cbq->pdev->refcnt);
+	kfree(cbq);
+}
+
+int cn_cb_equal(struct cb_id *i1, struct cb_id *i2)
+{
+	return ((i1->idx == i2->idx) && (i1->val == i2->val));
+}
+
+int cn_queue_add_callback(struct cn_queue_dev *dev, const char *name,
+			  struct cb_id *id,
+			  void (*callback)(struct cn_msg *, struct netlink_skb_parms *))
+{
+	struct cn_callback_entry *cbq, *__cbq;
+	int found = 0;
+
+	cbq = cn_queue_alloc_callback_entry(dev, name, id, callback);
+	if (!cbq)
+		return -ENOMEM;
+
+	spin_lock_bh(&dev->queue_lock);
+	list_for_each_entry(__cbq, &dev->queue_list, callback_entry) {
+		if (cn_cb_equal(&__cbq->id.id, id)) {
+			found = 1;
+			break;
+		}
+	}
+	if (!found)
+		list_add_tail(&cbq->callback_entry, &dev->queue_list);
+	spin_unlock_bh(&dev->queue_lock);
+
+	if (found) {
+		cn_queue_release_callback(cbq);
+		return -EINVAL;
+	}
+
+	cbq->seq = 0;
+	cbq->group = cbq->id.id.idx;
+
+	return 0;
+}
+
+void cn_queue_del_callback(struct cn_queue_dev *dev, struct cb_id *id)
+{
+	struct cn_callback_entry *cbq, *n;
+	int found = 0;
+
+	spin_lock_bh(&dev->queue_lock);
+	list_for_each_entry_safe(cbq, n, &dev->queue_list, callback_entry) {
+		if (cn_cb_equal(&cbq->id.id, id)) {
+			list_del(&cbq->callback_entry);
+			found = 1;
+			break;
+		}
+	}
+	spin_unlock_bh(&dev->queue_lock);
+
+	if (found)
+		cn_queue_release_callback(cbq);
+}
+
+struct cn_queue_dev *cn_queue_alloc_dev(const char *name, struct sock *nls)
+{
+	struct cn_queue_dev *dev;
+
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (!dev)
+		return NULL;
+
+	snprintf(dev->name, sizeof(dev->name), "%s", name);
+	atomic_set(&dev->refcnt, 0);
+	INIT_LIST_HEAD(&dev->queue_list);
+	spin_lock_init(&dev->queue_lock);
+
+	dev->nls = nls;
+
+	return dev;
+}
+
+void cn_queue_free_dev(struct cn_queue_dev *dev)
+{
+	struct cn_callback_entry *cbq, *n;
+
+	spin_lock_bh(&dev->queue_lock);
+	list_for_each_entry_safe(cbq, n, &dev->queue_list, callback_entry)
+		list_del(&cbq->callback_entry);
+	spin_unlock_bh(&dev->queue_lock);
+
+	while (atomic_read(&dev->refcnt)) {
+		printk(KERN_INFO "Waiting for %s to become free: refcnt=%d.\n",
+		       dev->name, atomic_read(&dev->refcnt));
+		msleep(1000);
+	}
+
+	kfree(dev);
+	dev = NULL;
+}

kernel/drivers/connector/connector.c

@@ -0,0 +1,292 @@
+/*
+ * 	connector.c
+ *
+ * 2004+ Copyright (c) Evgeniy Polyakov <zbr@ioremap.net>
+ * All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/list.h>
+#include <linux/skbuff.h>
+#include <linux/netlink.h>
+#include <linux/moduleparam.h>
+#include <linux/connector.h>
+#include <linux/slab.h>
+#include <linux/mutex.h>
+#include <linux/proc_fs.h>
+#include <linux/spinlock.h>
+
+#include <net/sock.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
+MODULE_DESCRIPTION("Generic userspace <-> kernelspace connector.");
+MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_CONNECTOR);
+
+static struct cn_dev cdev;
+
+static int cn_already_initialized;
+
+/*
+ * msg->seq and msg->ack are used to determine message genealogy.
+ * When someone sends message it puts there locally unique sequence
+ * and random acknowledge numbers.  Sequence number may be copied into
+ * nlmsghdr->nlmsg_seq too.
+ *
+ * Sequence number is incremented with each message to be sent.
+ *
+ * If we expect reply to our message then the sequence number in
+ * received message MUST be the same as in original message, and
+ * acknowledge number MUST be the same + 1.
+ *
+ * If we receive a message and its sequence number is not equal to the
+ * one we are expecting then it is a new message.
+ *
+ * If we receive a message and its sequence number is the same as one
+ * we are expecting but it's acknowledgement number is not equal to
+ * the acknowledgement number in the original message + 1, then it is
+ * a new message.
+ *
+ */
+int cn_netlink_send(struct cn_msg *msg, u32 __group, gfp_t gfp_mask)
+{
+	struct cn_callback_entry *__cbq;
+	unsigned int size;
+	struct sk_buff *skb;
+	struct nlmsghdr *nlh;
+	struct cn_msg *data;
+	struct cn_dev *dev = &cdev;
+	u32 group = 0;
+	int found = 0;
+
+	if (!__group) {
+		spin_lock_bh(&dev->cbdev->queue_lock);
+		list_for_each_entry(__cbq, &dev->cbdev->queue_list,
+				    callback_entry) {
+			if (cn_cb_equal(&__cbq->id.id, &msg->id)) {
+				found = 1;
+				group = __cbq->group;
+				break;
+			}
+		}
+		spin_unlock_bh(&dev->cbdev->queue_lock);
+
+		if (!found)
+			return -ENODEV;
+	} else {
+		group = __group;
+	}
+
+	if (!netlink_has_listeners(dev->nls, group))
+		return -ESRCH;
+
+	size = NLMSG_SPACE(sizeof(*msg) + msg->len);
+
+	skb = alloc_skb(size, gfp_mask);
+	if (!skb)
+		return -ENOMEM;
+
+	nlh = NLMSG_PUT(skb, 0, msg->seq, NLMSG_DONE, size - sizeof(*nlh));
+
+	data = NLMSG_DATA(nlh);
+
+	memcpy(data, msg, sizeof(*data) + msg->len);
+
+	NETLINK_CB(skb).dst_group = group;
+
+	return netlink_broadcast(dev->nls, skb, 0, group, gfp_mask);
+
+nlmsg_failure:
+	kfree_skb(skb);
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(cn_netlink_send);
+
+/*
+ * Callback helper - queues work and setup destructor for given data.
+ */
+static int cn_call_callback(struct sk_buff *skb)
+{
+	struct cn_callback_entry *i, *cbq = NULL;
+	struct cn_dev *dev = &cdev;
+	struct cn_msg *msg = NLMSG_DATA(nlmsg_hdr(skb));
+	struct netlink_skb_parms *nsp = &NETLINK_CB(skb);
+	int err = -ENODEV;
+
+	spin_lock_bh(&dev->cbdev->queue_lock);
+	list_for_each_entry(i, &dev->cbdev->queue_list, callback_entry) {
+		if (cn_cb_equal(&i->id.id, &msg->id)) {
+			atomic_inc(&i->refcnt);
+			cbq = i;
+			break;
+		}
+	}
+	spin_unlock_bh(&dev->cbdev->queue_lock);
+
+	if (cbq != NULL) {
+		err = 0;
+		cbq->callback(msg, nsp);
+		kfree_skb(skb);
+		cn_queue_release_callback(cbq);
+		err = 0;
+	}
+
+	return err;
+}
+
+/*
+ * Main netlink receiving function.
+ *
+ * It checks skb, netlink header and msg sizes, and calls callback helper.
+ */
+static void cn_rx_skb(struct sk_buff *__skb)
+{
+	struct nlmsghdr *nlh;
+	int err;
+	struct sk_buff *skb;
+
+	skb = skb_get(__skb);
+
+	if (skb->len >= NLMSG_SPACE(0)) {
+		nlh = nlmsg_hdr(skb);
+
+		if (nlh->nlmsg_len < sizeof(struct cn_msg) ||
+		    skb->len < nlh->nlmsg_len ||
+		    nlh->nlmsg_len > CONNECTOR_MAX_MSG_SIZE) {
+			kfree_skb(skb);
+			return;
+		}
+
+		err = cn_call_callback(skb);
+		if (err < 0)
+			kfree_skb(skb);
+	}
+}
+
+/*
+ * Callback add routing - adds callback with given ID and name.
+ * If there is registered callback with the same ID it will not be added.
+ *
+ * May sleep.
+ */
+int cn_add_callback(struct cb_id *id, const char *name,
+		    void (*callback)(struct cn_msg *, struct netlink_skb_parms *))
+{
+	int err;
+	struct cn_dev *dev = &cdev;
+
+	if (!cn_already_initialized)
+		return -EAGAIN;
+
+	err = cn_queue_add_callback(dev->cbdev, name, id, callback);
+	if (err)
+		return err;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(cn_add_callback);
+
+/*
+ * Callback remove routing - removes callback
+ * with given ID.
+ * If there is no registered callback with given
+ * ID nothing happens.
+ *
+ * May sleep while waiting for reference counter to become zero.
+ */
+void cn_del_callback(struct cb_id *id)
+{
+	struct cn_dev *dev = &cdev;
+
+	cn_queue_del_callback(dev->cbdev, id);
+}
+EXPORT_SYMBOL_GPL(cn_del_callback);
+
+static int cn_proc_show(struct seq_file *m, void *v)
+{
+	struct cn_queue_dev *dev = cdev.cbdev;
+	struct cn_callback_entry *cbq;
+
+	seq_printf(m, "Name            ID\n");
+
+	spin_lock_bh(&dev->queue_lock);
+
+	list_for_each_entry(cbq, &dev->queue_list, callback_entry) {
+		seq_printf(m, "%-15s %u:%u\n",
+			   cbq->id.name,
+			   cbq->id.id.idx,
+			   cbq->id.id.val);
+	}
+
+	spin_unlock_bh(&dev->queue_lock);
+
+	return 0;
+}
+
+static int cn_proc_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, cn_proc_show, NULL);
+}
+
+static const struct file_operations cn_file_ops = {
+	.owner   = THIS_MODULE,
+	.open    = cn_proc_open,
+	.read    = seq_read,
+	.llseek  = seq_lseek,
+	.release = single_release
+};
+
+static int __devinit cn_init(void)
+{
+	struct cn_dev *dev = &cdev;
+
+	dev->input = cn_rx_skb;
+
+	dev->nls = netlink_kernel_create(&init_net, NETLINK_CONNECTOR,
+					 CN_NETLINK_USERS + 0xf,
+					 dev->input, NULL, THIS_MODULE);
+	if (!dev->nls)
+		return -EIO;
+
+	dev->cbdev = cn_queue_alloc_dev("cqueue", dev->nls);
+	if (!dev->cbdev) {
+		netlink_kernel_release(dev->nls);
+		return -EINVAL;
+	}
+
+	cn_already_initialized = 1;
+
+	proc_net_fops_create(&init_net, "connector", S_IRUGO, &cn_file_ops);
+
+	return 0;
+}
+
+static void __devexit cn_fini(void)
+{
+	struct cn_dev *dev = &cdev;
+
+	cn_already_initialized = 0;
+
+	proc_net_remove(&init_net, "connector");
+
+	cn_queue_free_dev(dev->cbdev);
+	netlink_kernel_release(dev->nls);
+}
+
+subsys_initcall(cn_init);
+module_exit(cn_fini);