[linux.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 <[email protected]>
 * 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 <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_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 <[email protected]>
	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>
9f46080c	31	#include <asm/atomic.h>
af3e095a	32	#include <asm/unaligned.h>
9f46080c MH	33
	34	#include <linux/cn_proc.h>
	35
	36	#define CN_PROC_MSG_SIZE (sizeof(struct cn_msg) + sizeof(struct proc_event))
	37
	38	static atomic_t proc_event_num_listeners = ATOMIC_INIT(0);
	39	static struct cb_id cn_proc_event_id = { CN_IDX_PROC, CN_VAL_PROC };
	40
cc398c2e	41	/* proc_event_counts is used as the sequence number of the netlink message */
9f46080c MH	42	static DEFINE_PER_CPU(__u32, proc_event_counts) = { 0 };
	43
	44	static inline void get_seq(__u32 ts, int cpu)
	45	{
3ea9f683 CL	46	preempt_disable();
3ea9f683 CL	47	*ts = __this_cpu_inc_return(proc_event_counts) -1;
9f46080c	48	*cpu = smp_processor_id();
3ea9f683	49	preempt_enable();
9f46080c MH	50	}
	51
	52	void proc_fork_connector(struct task_struct *task)
	53	{
	54	struct cn_msg *msg;
	55	struct proc_event *ev;
	56	__u8 buffer[CN_PROC_MSG_SIZE];
822cfbff	57	struct timespec ts;
9f46080c MH	58
	59	if (atomic_read(&proc_event_num_listeners) < 1)
	60	return;
	61
	62	msg = (struct cn_msg*)buffer;
	63	ev = (struct proc_event*)msg->data;
	64	get_seq(&msg->seq, &ev->cpu);
822cfbff	65	ktime_get_ts(&ts); /* get high res monotonic timestamp */
af3e095a	66	put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
9f46080c MH	67	ev->what = PROC_EVENT_FORK;
	68	ev->event_data.fork.parent_pid = task->real_parent->pid;
	69	ev->event_data.fork.parent_tgid = task->real_parent->tgid;
	70	ev->event_data.fork.child_pid = task->pid;
	71	ev->event_data.fork.child_tgid = task->tgid;
	72
	73	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
	74	msg->ack = 0; /* not used */
	75	msg->len = sizeof(*ev);
	76	/* If cn_netlink_send() failed, the data is not sent */
	77	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
	78	}
	79
	80	void proc_exec_connector(struct task_struct *task)
	81	{
	82	struct cn_msg *msg;
	83	struct proc_event *ev;
822cfbff	84	struct timespec ts;
9f46080c MH	85	__u8 buffer[CN_PROC_MSG_SIZE];
	86
	87	if (atomic_read(&proc_event_num_listeners) < 1)
	88	return;
	89
	90	msg = (struct cn_msg*)buffer;
	91	ev = (struct proc_event*)msg->data;
	92	get_seq(&msg->seq, &ev->cpu);
822cfbff	93	ktime_get_ts(&ts); /* get high res monotonic timestamp */
af3e095a	94	put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
9f46080c MH	95	ev->what = PROC_EVENT_EXEC;
	96	ev->event_data.exec.process_pid = task->pid;
	97	ev->event_data.exec.process_tgid = task->tgid;
	98
	99	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
	100	msg->ack = 0; /* not used */
	101	msg->len = sizeof(*ev);
	102	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
	103	}
	104
	105	void proc_id_connector(struct task_struct *task, int which_id)
	106	{
	107	struct cn_msg *msg;
	108	struct proc_event *ev;
	109	__u8 buffer[CN_PROC_MSG_SIZE];
822cfbff	110	struct timespec ts;
c69e8d9c	111	const struct cred *cred;
9f46080c MH	112
	113	if (atomic_read(&proc_event_num_listeners) < 1)
	114	return;
	115
	116	msg = (struct cn_msg*)buffer;
	117	ev = (struct proc_event*)msg->data;
	118	ev->what = which_id;
	119	ev->event_data.id.process_pid = task->pid;
	120	ev->event_data.id.process_tgid = task->tgid;
c69e8d9c DH	121	rcu_read_lock();
c69e8d9c DH	122	cred = __task_cred(task);
9f46080c	123	if (which_id == PROC_EVENT_UID) {
c69e8d9c DH	124	ev->event_data.id.r.ruid = cred->uid;
c69e8d9c DH	125	ev->event_data.id.e.euid = cred->euid;
9f46080c	126	} else if (which_id == PROC_EVENT_GID) {
c69e8d9c DH	127	ev->event_data.id.r.rgid = cred->gid;
	128	ev->event_data.id.e.egid = cred->egid;
	129	} else {
	130	rcu_read_unlock();
9f46080c	131	return;
c69e8d9c DH	132	}
c69e8d9c DH	133	rcu_read_unlock();
9f46080c	134	get_seq(&msg->seq, &ev->cpu);
822cfbff	135	ktime_get_ts(&ts); /* get high res monotonic timestamp */
af3e095a	136	put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
9f46080c MH	137
	138	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
	139	msg->ack = 0; /* not used */
	140	msg->len = sizeof(*ev);
	141	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
	142	}
	143
02b51df1 SJR	144	void proc_sid_connector(struct task_struct *task)
	145	{
	146	struct cn_msg *msg;
	147	struct proc_event *ev;
	148	struct timespec ts;
	149	__u8 buffer[CN_PROC_MSG_SIZE];
	150
	151	if (atomic_read(&proc_event_num_listeners) < 1)
	152	return;
	153
	154	msg = (struct cn_msg *)buffer;
	155	ev = (struct proc_event *)msg->data;
	156	get_seq(&msg->seq, &ev->cpu);
	157	ktime_get_ts(&ts); /* get high res monotonic timestamp */
	158	put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
	159	ev->what = PROC_EVENT_SID;
	160	ev->event_data.sid.process_pid = task->pid;
	161	ev->event_data.sid.process_tgid = task->tgid;
	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
9f46080c MH	169	void proc_exit_connector(struct task_struct *task)
	170	{
	171	struct cn_msg *msg;
	172	struct proc_event *ev;
	173	__u8 buffer[CN_PROC_MSG_SIZE];
822cfbff	174	struct timespec ts;
9f46080c MH	175
	176	if (atomic_read(&proc_event_num_listeners) < 1)
	177	return;
	178
	179	msg = (struct cn_msg*)buffer;
	180	ev = (struct proc_event*)msg->data;
	181	get_seq(&msg->seq, &ev->cpu);
822cfbff	182	ktime_get_ts(&ts); /* get high res monotonic timestamp */
af3e095a	183	put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
9f46080c MH	184	ev->what = PROC_EVENT_EXIT;
	185	ev->event_data.exit.process_pid = task->pid;
	186	ev->event_data.exit.process_tgid = task->tgid;
	187	ev->event_data.exit.exit_code = task->exit_code;
	188	ev->event_data.exit.exit_signal = task->exit_signal;
	189
	190	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
	191	msg->ack = 0; /* not used */
	192	msg->len = sizeof(*ev);
	193	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
	194	}
	195
	196	/*
	197	* Send an acknowledgement message to userspace
	198	*
	199	* Use 0 for success, EFOO otherwise.
	200	* Note: this is the negative of conventional kernel error
	201	* values because it's not being returned via syscall return
	202	* mechanisms.
	203	*/
	204	static void cn_proc_ack(int err, int rcvd_seq, int rcvd_ack)
	205	{
	206	struct cn_msg *msg;
	207	struct proc_event *ev;
	208	__u8 buffer[CN_PROC_MSG_SIZE];
822cfbff	209	struct timespec ts;
9f46080c MH	210
	211	if (atomic_read(&proc_event_num_listeners) < 1)
	212	return;
	213
	214	msg = (struct cn_msg*)buffer;
	215	ev = (struct proc_event*)msg->data;
	216	msg->seq = rcvd_seq;
822cfbff	217	ktime_get_ts(&ts); /* get high res monotonic timestamp */
af3e095a	218	put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
9f46080c MH	219	ev->cpu = -1;
	220	ev->what = PROC_EVENT_NONE;
	221	ev->event_data.ack.err = err;
	222	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
	223	msg->ack = rcvd_ack + 1;
	224	msg->len = sizeof(*ev);
	225	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
	226	}
	227
	228	/**
	229	* cn_proc_mcast_ctl
	230	* @data: message sent from userspace via the connector
	231	*/
f0b25932 SB	232	static void cn_proc_mcast_ctl(struct cn_msg *msg,
f0b25932 SB	233	struct netlink_skb_parms *nsp)
9f46080c	234	{
9f46080c MH	235	enum proc_cn_mcast_op *mc_op = NULL;
	236	int err = 0;
	237
	238	if (msg->len != sizeof(*mc_op))
	239	return;
	240
	241	mc_op = (enum proc_cn_mcast_op*)msg->data;
	242	switch (*mc_op) {
	243	case PROC_CN_MCAST_LISTEN:
	244	atomic_inc(&proc_event_num_listeners);
	245	break;
	246	case PROC_CN_MCAST_IGNORE:
	247	atomic_dec(&proc_event_num_listeners);
	248	break;
	249	default:
	250	err = EINVAL;
	251	break;
	252	}
	253	cn_proc_ack(err, msg->seq, msg->ack);
	254	}
	255
	256	/*
	257	* cn_proc_init - initialization entry point
	258	*
	259	* Adds the connector callback to the connector driver.
	260	*/
	261	static int __init cn_proc_init(void)
	262	{
	263	int err;
	264
	265	if ((err = cn_add_callback(&cn_proc_event_id, "cn_proc",
	266	&cn_proc_mcast_ctl))) {
	267	printk(KERN_WARNING "cn_proc failed to register\n");
	268	return err;
	269	}
	270	return 0;
	271	}
	272
	273	module_init(cn_proc_init);