[mirror_ubuntu-zesty-kernel.git] / drivers / connector / cn_proc.c

/*
 * 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 <asm/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;

	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;
	ev->event_data.fork.parent_pid = task->real_parent->pid;
	ev->event_data.fork.parent_tgid = task->real_parent->tgid;
	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_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);
Commit	Line	Data
9f46080c MH	1	/*
	2	* cn_proc.c - process events connector
	3	*
	4	* Copyright (C) Matt Helsley, IBM Corp. 2005
	5	* Based on cn_fork.c by Guillaume Thouvenin <guillaume.thouvenin@bull.net>
	6	* Original copyright notice follows:
	7	* Copyright (C) 2005 BULL SA.
	8	*
	9	*
	10	* This program is free software; you can redistribute it and/or modify
	11	* it under the terms of the GNU General Public License as published by
	12	* the Free Software Foundation; either version 2 of the License, or
	13	* (at your option) any later version.
	14	*
	15	* This program is distributed in the hope that it will be useful,
	16	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	17	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	18	* GNU General Public License for more details.
	19	*
	20	* You should have received a copy of the GNU General Public License
	21	* along with this program; if not, write to the Free Software
	22	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	23	*/
	24
	25	#include <linux/module.h>
	26	#include <linux/kernel.h>
caf3c9dc	27	#include <linux/ktime.h>
9f46080c	28	#include <linux/init.h>
1d31a4ea	29	#include <linux/connector.h>
5a0e3ad6	30	#include <linux/gfp.h>
f701e5b7	31	#include <linux/ptrace.h>
9f46080c	32	#include <asm/atomic.h>
af3e095a	33	#include <asm/unaligned.h>
9f46080c MH	34
	35	#include <linux/cn_proc.h>
	36
	37	#define CN_PROC_MSG_SIZE (sizeof(struct cn_msg) + sizeof(struct proc_event))
	38
	39	static atomic_t proc_event_num_listeners = ATOMIC_INIT(0);
	40	static struct cb_id cn_proc_event_id = { CN_IDX_PROC, CN_VAL_PROC };
	41
cc398c2e	42	/* proc_event_counts is used as the sequence number of the netlink message */
9f46080c MH	43	static DEFINE_PER_CPU(__u32, proc_event_counts) = { 0 };
	44
	45	static inline void get_seq(__u32 ts, int cpu)
	46	{
3ea9f683 CL	47	preempt_disable();
3ea9f683 CL	48	*ts = __this_cpu_inc_return(proc_event_counts) -1;
9f46080c	49	*cpu = smp_processor_id();
3ea9f683	50	preempt_enable();
9f46080c MH	51	}
	52
	53	void proc_fork_connector(struct task_struct *task)
	54	{
	55	struct cn_msg *msg;
	56	struct proc_event *ev;
	57	__u8 buffer[CN_PROC_MSG_SIZE];
822cfbff	58	struct timespec ts;
9f46080c MH	59
	60	if (atomic_read(&proc_event_num_listeners) < 1)
	61	return;
	62
	63	msg = (struct cn_msg*)buffer;
	64	ev = (struct proc_event*)msg->data;
	65	get_seq(&msg->seq, &ev->cpu);
822cfbff	66	ktime_get_ts(&ts); /* get high res monotonic timestamp */
af3e095a	67	put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
9f46080c MH	68	ev->what = PROC_EVENT_FORK;
	69	ev->event_data.fork.parent_pid = task->real_parent->pid;
	70	ev->event_data.fork.parent_tgid = task->real_parent->tgid;
	71	ev->event_data.fork.child_pid = task->pid;
	72	ev->event_data.fork.child_tgid = task->tgid;
	73
	74	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
	75	msg->ack = 0; /* not used */
	76	msg->len = sizeof(*ev);
	77	/* If cn_netlink_send() failed, the data is not sent */
	78	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
	79	}
	80
	81	void proc_exec_connector(struct task_struct *task)
	82	{
	83	struct cn_msg *msg;
	84	struct proc_event *ev;
822cfbff	85	struct timespec ts;
9f46080c MH	86	__u8 buffer[CN_PROC_MSG_SIZE];
	87
	88	if (atomic_read(&proc_event_num_listeners) < 1)
	89	return;
	90
	91	msg = (struct cn_msg*)buffer;
	92	ev = (struct proc_event*)msg->data;
	93	get_seq(&msg->seq, &ev->cpu);
822cfbff	94	ktime_get_ts(&ts); /* get high res monotonic timestamp */
af3e095a	95	put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
9f46080c MH	96	ev->what = PROC_EVENT_EXEC;
	97	ev->event_data.exec.process_pid = task->pid;
	98	ev->event_data.exec.process_tgid = task->tgid;
	99
	100	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
	101	msg->ack = 0; /* not used */
	102	msg->len = sizeof(*ev);
	103	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
	104	}
	105
	106	void proc_id_connector(struct task_struct *task, int which_id)
	107	{
	108	struct cn_msg *msg;
	109	struct proc_event *ev;
	110	__u8 buffer[CN_PROC_MSG_SIZE];
822cfbff	111	struct timespec ts;
c69e8d9c	112	const struct cred *cred;
9f46080c MH	113
	114	if (atomic_read(&proc_event_num_listeners) < 1)
	115	return;
	116
	117	msg = (struct cn_msg*)buffer;
	118	ev = (struct proc_event*)msg->data;
	119	ev->what = which_id;
	120	ev->event_data.id.process_pid = task->pid;
	121	ev->event_data.id.process_tgid = task->tgid;
c69e8d9c DH	122	rcu_read_lock();
c69e8d9c DH	123	cred = __task_cred(task);
9f46080c	124	if (which_id == PROC_EVENT_UID) {
c69e8d9c DH	125	ev->event_data.id.r.ruid = cred->uid;
c69e8d9c DH	126	ev->event_data.id.e.euid = cred->euid;
9f46080c	127	} else if (which_id == PROC_EVENT_GID) {
c69e8d9c DH	128	ev->event_data.id.r.rgid = cred->gid;
	129	ev->event_data.id.e.egid = cred->egid;
	130	} else {
	131	rcu_read_unlock();
9f46080c	132	return;
c69e8d9c DH	133	}
c69e8d9c DH	134	rcu_read_unlock();
9f46080c	135	get_seq(&msg->seq, &ev->cpu);
822cfbff	136	ktime_get_ts(&ts); /* get high res monotonic timestamp */
af3e095a	137	put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
9f46080c MH	138
	139	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
	140	msg->ack = 0; /* not used */
	141	msg->len = sizeof(*ev);
	142	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
	143	}
	144
02b51df1 SJR	145	void proc_sid_connector(struct task_struct *task)
	146	{
	147	struct cn_msg *msg;
	148	struct proc_event *ev;
	149	struct timespec ts;
	150	__u8 buffer[CN_PROC_MSG_SIZE];
	151
	152	if (atomic_read(&proc_event_num_listeners) < 1)
	153	return;
	154
	155	msg = (struct cn_msg *)buffer;
	156	ev = (struct proc_event *)msg->data;
	157	get_seq(&msg->seq, &ev->cpu);
	158	ktime_get_ts(&ts); /* get high res monotonic timestamp */
	159	put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
	160	ev->what = PROC_EVENT_SID;
	161	ev->event_data.sid.process_pid = task->pid;
	162	ev->event_data.sid.process_tgid = task->tgid;
	163
	164	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
	165	msg->ack = 0; /* not used */
	166	msg->len = sizeof(*ev);
	167	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
	168	}
	169
f701e5b7 VZ	170	void proc_ptrace_connector(struct task_struct *task, int ptrace_id)
	171	{
	172	struct cn_msg *msg;
	173	struct proc_event *ev;
	174	struct timespec ts;
	175	__u8 buffer[CN_PROC_MSG_SIZE];
f701e5b7 VZ	176
	177	if (atomic_read(&proc_event_num_listeners) < 1)
	178	return;
	179
	180	msg = (struct cn_msg *)buffer;
	181	ev = (struct proc_event *)msg->data;
	182	get_seq(&msg->seq, &ev->cpu);
	183	ktime_get_ts(&ts); /* get high res monotonic timestamp */
	184	put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
	185	ev->what = PROC_EVENT_PTRACE;
	186	ev->event_data.ptrace.process_pid = task->pid;
	187	ev->event_data.ptrace.process_tgid = task->tgid;
	188	if (ptrace_id == PTRACE_ATTACH) {
	189	ev->event_data.ptrace.tracer_pid = current->pid;
	190	ev->event_data.ptrace.tracer_tgid = current->tgid;
	191	} else if (ptrace_id == PTRACE_DETACH) {
	192	ev->event_data.ptrace.tracer_pid = 0;
	193	ev->event_data.ptrace.tracer_tgid = 0;
	194	} else
	195	return;
	196
	197	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
	198	msg->ack = 0; /* not used */
	199	msg->len = sizeof(*ev);
	200	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
	201	}
	202
9f46080c MH	203	void proc_exit_connector(struct task_struct *task)
	204	{
	205	struct cn_msg *msg;
	206	struct proc_event *ev;
	207	__u8 buffer[CN_PROC_MSG_SIZE];
822cfbff	208	struct timespec ts;
9f46080c MH	209
	210	if (atomic_read(&proc_event_num_listeners) < 1)
	211	return;
	212
	213	msg = (struct cn_msg*)buffer;
	214	ev = (struct proc_event*)msg->data;
	215	get_seq(&msg->seq, &ev->cpu);
822cfbff	216	ktime_get_ts(&ts); /* get high res monotonic timestamp */
af3e095a	217	put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
9f46080c MH	218	ev->what = PROC_EVENT_EXIT;
	219	ev->event_data.exit.process_pid = task->pid;
	220	ev->event_data.exit.process_tgid = task->tgid;
	221	ev->event_data.exit.exit_code = task->exit_code;
	222	ev->event_data.exit.exit_signal = task->exit_signal;
	223
	224	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
	225	msg->ack = 0; /* not used */
	226	msg->len = sizeof(*ev);
	227	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
	228	}
	229
	230	/*
	231	* Send an acknowledgement message to userspace
	232	*
	233	* Use 0 for success, EFOO otherwise.
	234	* Note: this is the negative of conventional kernel error
	235	* values because it's not being returned via syscall return
	236	* mechanisms.
	237	*/
	238	static void cn_proc_ack(int err, int rcvd_seq, int rcvd_ack)
	239	{
	240	struct cn_msg *msg;
	241	struct proc_event *ev;
	242	__u8 buffer[CN_PROC_MSG_SIZE];
822cfbff	243	struct timespec ts;
9f46080c MH	244
	245	if (atomic_read(&proc_event_num_listeners) < 1)
	246	return;
	247
	248	msg = (struct cn_msg*)buffer;
	249	ev = (struct proc_event*)msg->data;
	250	msg->seq = rcvd_seq;
822cfbff	251	ktime_get_ts(&ts); /* get high res monotonic timestamp */
af3e095a	252	put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
9f46080c MH	253	ev->cpu = -1;
	254	ev->what = PROC_EVENT_NONE;
	255	ev->event_data.ack.err = err;
	256	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
	257	msg->ack = rcvd_ack + 1;
	258	msg->len = sizeof(*ev);
	259	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
	260	}
	261
	262	/**
	263	* cn_proc_mcast_ctl
	264	* @data: message sent from userspace via the connector
	265	*/
f0b25932 SB	266	static void cn_proc_mcast_ctl(struct cn_msg *msg,
f0b25932 SB	267	struct netlink_skb_parms *nsp)
9f46080c	268	{
9f46080c MH	269	enum proc_cn_mcast_op *mc_op = NULL;
	270	int err = 0;
	271
	272	if (msg->len != sizeof(*mc_op))
	273	return;
	274
	275	mc_op = (enum proc_cn_mcast_op*)msg->data;
	276	switch (*mc_op) {
	277	case PROC_CN_MCAST_LISTEN:
	278	atomic_inc(&proc_event_num_listeners);
	279	break;
	280	case PROC_CN_MCAST_IGNORE:
	281	atomic_dec(&proc_event_num_listeners);
	282	break;
	283	default:
	284	err = EINVAL;
	285	break;
	286	}
	287	cn_proc_ack(err, msg->seq, msg->ack);
	288	}
	289
	290	/*
	291	* cn_proc_init - initialization entry point
	292	*
	293	* Adds the connector callback to the connector driver.
	294	*/
	295	static int __init cn_proc_init(void)
	296	{
	297	int err;
	298
	299	if ((err = cn_add_callback(&cn_proc_event_id, "cn_proc",
	300	&cn_proc_mcast_ctl))) {
	301	printk(KERN_WARNING "cn_proc failed to register\n");
	302	return err;
	303	}
	304	return 0;
	305	}
	306
	307	module_init(cn_proc_init);