[linux-2.6-block.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 <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)
{
	*ts = get_cpu_var(proc_event_counts)++;
	*cpu = smp_processor_id();
	put_cpu_var(proc_event_counts);
}

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_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)
{
	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>
9f46080c	30	#include <asm/atomic.h>
af3e095a	31	#include <asm/unaligned.h>
9f46080c MH	32
	33	#include <linux/cn_proc.h>
	34
	35	#define CN_PROC_MSG_SIZE (sizeof(struct cn_msg) + sizeof(struct proc_event))
	36
	37	static atomic_t proc_event_num_listeners = ATOMIC_INIT(0);
	38	static struct cb_id cn_proc_event_id = { CN_IDX_PROC, CN_VAL_PROC };
	39
cc398c2e	40	/* proc_event_counts is used as the sequence number of the netlink message */
9f46080c MH	41	static DEFINE_PER_CPU(__u32, proc_event_counts) = { 0 };
	42
	43	static inline void get_seq(__u32 ts, int cpu)
	44	{
	45	*ts = get_cpu_var(proc_event_counts)++;
	46	*cpu = smp_processor_id();
cc398c2e	47	put_cpu_var(proc_event_counts);
9f46080c MH	48	}
	49
	50	void proc_fork_connector(struct task_struct *task)
	51	{
	52	struct cn_msg *msg;
	53	struct proc_event *ev;
	54	__u8 buffer[CN_PROC_MSG_SIZE];
822cfbff	55	struct timespec ts;
9f46080c MH	56
	57	if (atomic_read(&proc_event_num_listeners) < 1)
	58	return;
	59
	60	msg = (struct cn_msg*)buffer;
	61	ev = (struct proc_event*)msg->data;
	62	get_seq(&msg->seq, &ev->cpu);
822cfbff	63	ktime_get_ts(&ts); /* get high res monotonic timestamp */
af3e095a	64	put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
9f46080c MH	65	ev->what = PROC_EVENT_FORK;
	66	ev->event_data.fork.parent_pid = task->real_parent->pid;
	67	ev->event_data.fork.parent_tgid = task->real_parent->tgid;
	68	ev->event_data.fork.child_pid = task->pid;
	69	ev->event_data.fork.child_tgid = task->tgid;
	70
	71	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
	72	msg->ack = 0; /* not used */
	73	msg->len = sizeof(*ev);
	74	/* If cn_netlink_send() failed, the data is not sent */
	75	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
	76	}
	77
	78	void proc_exec_connector(struct task_struct *task)
	79	{
	80	struct cn_msg *msg;
	81	struct proc_event *ev;
822cfbff	82	struct timespec ts;
9f46080c MH	83	__u8 buffer[CN_PROC_MSG_SIZE];
	84
	85	if (atomic_read(&proc_event_num_listeners) < 1)
	86	return;
	87
	88	msg = (struct cn_msg*)buffer;
	89	ev = (struct proc_event*)msg->data;
	90	get_seq(&msg->seq, &ev->cpu);
822cfbff	91	ktime_get_ts(&ts); /* get high res monotonic timestamp */
af3e095a	92	put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
9f46080c MH	93	ev->what = PROC_EVENT_EXEC;
	94	ev->event_data.exec.process_pid = task->pid;
	95	ev->event_data.exec.process_tgid = task->tgid;
	96
	97	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
	98	msg->ack = 0; /* not used */
	99	msg->len = sizeof(*ev);
	100	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
	101	}
	102
	103	void proc_id_connector(struct task_struct *task, int which_id)
	104	{
	105	struct cn_msg *msg;
	106	struct proc_event *ev;
	107	__u8 buffer[CN_PROC_MSG_SIZE];
822cfbff	108	struct timespec ts;
c69e8d9c	109	const struct cred *cred;
9f46080c MH	110
	111	if (atomic_read(&proc_event_num_listeners) < 1)
	112	return;
	113
	114	msg = (struct cn_msg*)buffer;
	115	ev = (struct proc_event*)msg->data;
	116	ev->what = which_id;
	117	ev->event_data.id.process_pid = task->pid;
	118	ev->event_data.id.process_tgid = task->tgid;
c69e8d9c DH	119	rcu_read_lock();
c69e8d9c DH	120	cred = __task_cred(task);
9f46080c	121	if (which_id == PROC_EVENT_UID) {
c69e8d9c DH	122	ev->event_data.id.r.ruid = cred->uid;
c69e8d9c DH	123	ev->event_data.id.e.euid = cred->euid;
9f46080c	124	} else if (which_id == PROC_EVENT_GID) {
c69e8d9c DH	125	ev->event_data.id.r.rgid = cred->gid;
	126	ev->event_data.id.e.egid = cred->egid;
	127	} else {
	128	rcu_read_unlock();
9f46080c	129	return;
c69e8d9c DH	130	}
c69e8d9c DH	131	rcu_read_unlock();
9f46080c	132	get_seq(&msg->seq, &ev->cpu);
822cfbff	133	ktime_get_ts(&ts); /* get high res monotonic timestamp */
af3e095a	134	put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
9f46080c MH	135
	136	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
	137	msg->ack = 0; /* not used */
	138	msg->len = sizeof(*ev);
	139	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
	140	}
	141
	142	void proc_exit_connector(struct task_struct *task)
	143	{
	144	struct cn_msg *msg;
	145	struct proc_event *ev;
	146	__u8 buffer[CN_PROC_MSG_SIZE];
822cfbff	147	struct timespec ts;
9f46080c MH	148
	149	if (atomic_read(&proc_event_num_listeners) < 1)
	150	return;
	151
	152	msg = (struct cn_msg*)buffer;
	153	ev = (struct proc_event*)msg->data;
	154	get_seq(&msg->seq, &ev->cpu);
822cfbff	155	ktime_get_ts(&ts); /* get high res monotonic timestamp */
af3e095a	156	put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
9f46080c MH	157	ev->what = PROC_EVENT_EXIT;
	158	ev->event_data.exit.process_pid = task->pid;
	159	ev->event_data.exit.process_tgid = task->tgid;
	160	ev->event_data.exit.exit_code = task->exit_code;
	161	ev->event_data.exit.exit_signal = task->exit_signal;
	162
	163	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
	164	msg->ack = 0; /* not used */
	165	msg->len = sizeof(*ev);
	166	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
	167	}
	168
	169	/*
	170	* Send an acknowledgement message to userspace
	171	*
	172	* Use 0 for success, EFOO otherwise.
	173	* Note: this is the negative of conventional kernel error
	174	* values because it's not being returned via syscall return
	175	* mechanisms.
	176	*/
	177	static void cn_proc_ack(int err, int rcvd_seq, int rcvd_ack)
	178	{
	179	struct cn_msg *msg;
	180	struct proc_event *ev;
	181	__u8 buffer[CN_PROC_MSG_SIZE];
822cfbff	182	struct timespec ts;
9f46080c MH	183
	184	if (atomic_read(&proc_event_num_listeners) < 1)
	185	return;
	186
	187	msg = (struct cn_msg*)buffer;
	188	ev = (struct proc_event*)msg->data;
	189	msg->seq = rcvd_seq;
822cfbff	190	ktime_get_ts(&ts); /* get high res monotonic timestamp */
af3e095a	191	put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
9f46080c MH	192	ev->cpu = -1;
	193	ev->what = PROC_EVENT_NONE;
	194	ev->event_data.ack.err = err;
	195	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
	196	msg->ack = rcvd_ack + 1;
	197	msg->len = sizeof(*ev);
	198	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
	199	}
	200
	201	/**
	202	* cn_proc_mcast_ctl
	203	* @data: message sent from userspace via the connector
	204	*/
0741241c	205	static void cn_proc_mcast_ctl(struct cn_msg *msg)
9f46080c	206	{
9f46080c MH	207	enum proc_cn_mcast_op *mc_op = NULL;
	208	int err = 0;
	209
	210	if (msg->len != sizeof(*mc_op))
	211	return;
	212
	213	mc_op = (enum proc_cn_mcast_op*)msg->data;
	214	switch (*mc_op) {
	215	case PROC_CN_MCAST_LISTEN:
	216	atomic_inc(&proc_event_num_listeners);
	217	break;
	218	case PROC_CN_MCAST_IGNORE:
	219	atomic_dec(&proc_event_num_listeners);
	220	break;
	221	default:
	222	err = EINVAL;
	223	break;
	224	}
	225	cn_proc_ack(err, msg->seq, msg->ack);
	226	}
	227
	228	/*
	229	* cn_proc_init - initialization entry point
	230	*
	231	* Adds the connector callback to the connector driver.
	232	*/
	233	static int __init cn_proc_init(void)
	234	{
	235	int err;
	236
	237	if ((err = cn_add_callback(&cn_proc_event_id, "cn_proc",
	238	&cn_proc_mcast_ctl))) {
	239	printk(KERN_WARNING "cn_proc failed to register\n");
	240	return err;
	241	}
	242	return 0;
	243	}
	244
	245	module_init(cn_proc_init);