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

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * 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.
 */

#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 <linux/pid_namespace.h>

#include <linux/cn_proc.h>

/*
 * Size of a cn_msg followed by a proc_event structure.  Since the
 * sizeof struct cn_msg is a multiple of 4 bytes, but not 8 bytes, we
 * add one 4-byte word to the size here, and then start the actual
 * cn_msg structure 4 bytes into the stack buffer.  The result is that
 * the immediately following proc_event structure is aligned to 8 bytes.
 */
#define CN_PROC_MSG_SIZE (sizeof(struct cn_msg) + sizeof(struct proc_event) + 4)

/* See comment above; we test our assumption about sizeof struct cn_msg here. */
static inline struct cn_msg *buffer_to_cn_msg(__u8 *buffer)
{
	BUILD_BUG_ON(sizeof(struct cn_msg) != 20);
	return (struct cn_msg *)(buffer + 4);
}

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 send_msg(struct cn_msg *msg)
{
	preempt_disable();

	msg->seq = __this_cpu_inc_return(proc_event_counts) - 1;
	((struct proc_event *)msg->data)->cpu = smp_processor_id();

	/*
	 * Preemption remains disabled during send to ensure the messages are
	 * ordered according to their sequence numbers.
	 *
	 * If cn_netlink_send() fails, the data is not sent.
	 */
	cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_NOWAIT);

	preempt_enable();
}

void proc_fork_connector(struct task_struct *task)
{
	struct cn_msg *msg;
	struct proc_event *ev;
	__u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
	struct task_struct *parent;

	if (atomic_read(&proc_event_num_listeners) < 1)
		return;

	msg = buffer_to_cn_msg(buffer);
	ev = (struct proc_event *)msg->data;
	memset(&ev->event_data, 0, sizeof(ev->event_data));
	ev->timestamp_ns = ktime_get_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);
	msg->flags = 0; /* not used */
	send_msg(msg);
}

void proc_exec_connector(struct task_struct *task)
{
	struct cn_msg *msg;
	struct proc_event *ev;
	__u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);

	if (atomic_read(&proc_event_num_listeners) < 1)
		return;

	msg = buffer_to_cn_msg(buffer);
	ev = (struct proc_event *)msg->data;
	memset(&ev->event_data, 0, sizeof(ev->event_data));
	ev->timestamp_ns = ktime_get_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);
	msg->flags = 0; /* not used */
	send_msg(msg);
}

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] __aligned(8);
	const struct cred *cred;

	if (atomic_read(&proc_event_num_listeners) < 1)
		return;

	msg = buffer_to_cn_msg(buffer);
	ev = (struct proc_event *)msg->data;
	memset(&ev->event_data, 0, sizeof(ev->event_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 = from_kuid_munged(&init_user_ns, cred->uid);
		ev->event_data.id.e.euid = from_kuid_munged(&init_user_ns, cred->euid);
	} else if (which_id == PROC_EVENT_GID) {
		ev->event_data.id.r.rgid = from_kgid_munged(&init_user_ns, cred->gid);
		ev->event_data.id.e.egid = from_kgid_munged(&init_user_ns, cred->egid);
	} else {
		rcu_read_unlock();
		return;
	}
	rcu_read_unlock();
	ev->timestamp_ns = ktime_get_ns();

	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
	msg->ack = 0; /* not used */
	msg->len = sizeof(*ev);
	msg->flags = 0; /* not used */
	send_msg(msg);
}

void proc_sid_connector(struct task_struct *task)
{
	struct cn_msg *msg;
	struct proc_event *ev;
	__u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);

	if (atomic_read(&proc_event_num_listeners) < 1)
		return;

	msg = buffer_to_cn_msg(buffer);
	ev = (struct proc_event *)msg->data;
	memset(&ev->event_data, 0, sizeof(ev->event_data));
	ev->timestamp_ns = ktime_get_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);
	msg->flags = 0; /* not used */
	send_msg(msg);
}

void proc_ptrace_connector(struct task_struct *task, int ptrace_id)
{
	struct cn_msg *msg;
	struct proc_event *ev;
	__u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);

	if (atomic_read(&proc_event_num_listeners) < 1)
		return;

	msg = buffer_to_cn_msg(buffer);
	ev = (struct proc_event *)msg->data;
	memset(&ev->event_data, 0, sizeof(ev->event_data));
	ev->timestamp_ns = ktime_get_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);
	msg->flags = 0; /* not used */
	send_msg(msg);
}

void proc_comm_connector(struct task_struct *task)
{
	struct cn_msg *msg;
	struct proc_event *ev;
	__u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);

	if (atomic_read(&proc_event_num_listeners) < 1)
		return;

	msg = buffer_to_cn_msg(buffer);
	ev = (struct proc_event *)msg->data;
	memset(&ev->event_data, 0, sizeof(ev->event_data));
	ev->timestamp_ns = ktime_get_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);
	msg->flags = 0; /* not used */
	send_msg(msg);
}

void proc_coredump_connector(struct task_struct *task)
{
	struct cn_msg *msg;
	struct proc_event *ev;
	struct task_struct *parent;
	__u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);

	if (atomic_read(&proc_event_num_listeners) < 1)
		return;

	msg = buffer_to_cn_msg(buffer);
	ev = (struct proc_event *)msg->data;
	memset(&ev->event_data, 0, sizeof(ev->event_data));
	ev->timestamp_ns = ktime_get_ns();
	ev->what = PROC_EVENT_COREDUMP;
	ev->event_data.coredump.process_pid = task->pid;
	ev->event_data.coredump.process_tgid = task->tgid;

	rcu_read_lock();
	if (pid_alive(task)) {
		parent = rcu_dereference(task->real_parent);
		ev->event_data.coredump.parent_pid = parent->pid;
		ev->event_data.coredump.parent_tgid = parent->tgid;
	}
	rcu_read_unlock();

	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
	msg->ack = 0; /* not used */
	msg->len = sizeof(*ev);
	msg->flags = 0; /* not used */
	send_msg(msg);
}

void proc_exit_connector(struct task_struct *task)
{
	struct cn_msg *msg;
	struct proc_event *ev;
	struct task_struct *parent;
	__u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);

	if (atomic_read(&proc_event_num_listeners) < 1)
		return;

	msg = buffer_to_cn_msg(buffer);
	ev = (struct proc_event *)msg->data;
	memset(&ev->event_data, 0, sizeof(ev->event_data));
	ev->timestamp_ns = ktime_get_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;

	rcu_read_lock();
	if (pid_alive(task)) {
		parent = rcu_dereference(task->real_parent);
		ev->event_data.exit.parent_pid = parent->pid;
		ev->event_data.exit.parent_tgid = parent->tgid;
	}
	rcu_read_unlock();

	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
	msg->ack = 0; /* not used */
	msg->len = sizeof(*ev);
	msg->flags = 0; /* not used */
	send_msg(msg);
}

/*
 * 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] __aligned(8);

	if (atomic_read(&proc_event_num_listeners) < 1)
		return;

	msg = buffer_to_cn_msg(buffer);
	ev = (struct proc_event *)msg->data;
	memset(&ev->event_data, 0, sizeof(ev->event_data));
	msg->seq = rcvd_seq;
	ev->timestamp_ns = ktime_get_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);
	msg->flags = 0; /* not used */
	send_msg(msg);
}

/**
 * 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;

	/* 
	 * Events are reported with respect to the initial pid
	 * and user namespaces so ignore requestors from
	 * other namespaces.
	 */
	if ((current_user_ns() != &init_user_ns) ||
	    (task_active_pid_ns(current) != &init_pid_ns))
		return;

	/* Can only change if privileged. */
	if (!__netlink_ns_capable(nsp, &init_user_ns, CAP_NET_ADMIN)) {
		err = EPERM;
		goto out;
	}

	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;
	}

out:
	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 = cn_add_callback(&cn_proc_event_id,
				  "cn_proc",
				  &cn_proc_mcast_ctl);
	if (err) {
		pr_warn("cn_proc failed to register\n");
		return err;
	}
	return 0;
}
device_initcall(cn_proc_init);
Commit	Line	Data
1a59d1b8	1	// SPDX-License-Identifier: GPL-2.0-or-later
9f46080c MH	2	/*
	3	* cn_proc.c - process events connector
	4	*
	5	* Copyright (C) Matt Helsley, IBM Corp. 2005
	6	* Based on cn_fork.c by Guillaume Thouvenin <guillaume.thouvenin@bull.net>
	7	* Original copyright notice follows:
	8	* Copyright (C) 2005 BULL SA.
9f46080c MH	9	*/
9f46080c MH	10
9f46080c	11	#include <linux/kernel.h>
caf3c9dc	12	#include <linux/ktime.h>
9f46080c	13	#include <linux/init.h>
1d31a4ea	14	#include <linux/connector.h>
5a0e3ad6	15	#include <linux/gfp.h>
f701e5b7	16	#include <linux/ptrace.h>
60063497	17	#include <linux/atomic.h>
9582d901	18	#include <linux/pid_namespace.h>
60063497	19
9f46080c MH	20	#include <linux/cn_proc.h>
9f46080c MH	21
1ca1a4cf CM	22	/*
	23	* Size of a cn_msg followed by a proc_event structure. Since the
	24	* sizeof struct cn_msg is a multiple of 4 bytes, but not 8 bytes, we
	25	* add one 4-byte word to the size here, and then start the actual
	26	* cn_msg structure 4 bytes into the stack buffer. The result is that
	27	* the immediately following proc_event structure is aligned to 8 bytes.
	28	*/
	29	#define CN_PROC_MSG_SIZE (sizeof(struct cn_msg) + sizeof(struct proc_event) + 4)
	30
	31	/* See comment above; we test our assumption about sizeof struct cn_msg here. */
	32	static inline struct cn_msg buffer_to_cn_msg(__u8 buffer)
	33	{
	34	BUILD_BUG_ON(sizeof(struct cn_msg) != 20);
	35	return (struct cn_msg *)(buffer + 4);
	36	}
9f46080c MH	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 };
9f46080c MH	43
ab8ed951	44	static inline void send_msg(struct cn_msg *msg)
9f46080c	45	{
3ea9f683	46	preempt_disable();
ab8ed951 AC	47
	48	msg->seq = __this_cpu_inc_return(proc_event_counts) - 1;
	49	((struct proc_event *)msg->data)->cpu = smp_processor_id();
	50
	51	/*
	52	* Preemption remains disabled during send to ensure the messages are
	53	* ordered according to their sequence numbers.
	54	*
	55	* If cn_netlink_send() fails, the data is not sent.
	56	*/
	57	cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_NOWAIT);
	58
3ea9f683	59	preempt_enable();
9f46080c MH	60	}
	61
	62	void proc_fork_connector(struct task_struct *task)
	63	{
	64	struct cn_msg *msg;
	65	struct proc_event *ev;
1ca1a4cf	66	__u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
9e8f90df	67	struct task_struct *parent;
9f46080c MH	68
	69	if (atomic_read(&proc_event_num_listeners) < 1)
	70	return;
	71
1ca1a4cf	72	msg = buffer_to_cn_msg(buffer);
f3c48ecc	73	ev = (struct proc_event *)msg->data;
e727ca82	74	memset(&ev->event_data, 0, sizeof(ev->event_data));
9e93f21b	75	ev->timestamp_ns = ktime_get_ns();
9f46080c	76	ev->what = PROC_EVENT_FORK;
9e8f90df ON	77	rcu_read_lock();
	78	parent = rcu_dereference(task->real_parent);
	79	ev->event_data.fork.parent_pid = parent->pid;
	80	ev->event_data.fork.parent_tgid = parent->tgid;
	81	rcu_read_unlock();
9f46080c MH	82	ev->event_data.fork.child_pid = task->pid;
	83	ev->event_data.fork.child_tgid = task->tgid;
	84
	85	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
	86	msg->ack = 0; /* not used */
	87	msg->len = sizeof(*ev);
e727ca82	88	msg->flags = 0; /* not used */
ab8ed951	89	send_msg(msg);
9f46080c MH	90	}
	91
	92	void proc_exec_connector(struct task_struct *task)
	93	{
	94	struct cn_msg *msg;
	95	struct proc_event *ev;
1ca1a4cf	96	__u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
9f46080c MH	97
	98	if (atomic_read(&proc_event_num_listeners) < 1)
	99	return;
	100
1ca1a4cf	101	msg = buffer_to_cn_msg(buffer);
f3c48ecc	102	ev = (struct proc_event *)msg->data;
e727ca82	103	memset(&ev->event_data, 0, sizeof(ev->event_data));
9e93f21b	104	ev->timestamp_ns = ktime_get_ns();
9f46080c MH	105	ev->what = PROC_EVENT_EXEC;
	106	ev->event_data.exec.process_pid = task->pid;
	107	ev->event_data.exec.process_tgid = task->tgid;
	108
	109	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
	110	msg->ack = 0; /* not used */
	111	msg->len = sizeof(*ev);
e727ca82	112	msg->flags = 0; /* not used */
ab8ed951	113	send_msg(msg);
9f46080c MH	114	}
	115
	116	void proc_id_connector(struct task_struct *task, int which_id)
	117	{
	118	struct cn_msg *msg;
	119	struct proc_event *ev;
1ca1a4cf	120	__u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
c69e8d9c	121	const struct cred *cred;
9f46080c MH	122
	123	if (atomic_read(&proc_event_num_listeners) < 1)
	124	return;
	125
1ca1a4cf	126	msg = buffer_to_cn_msg(buffer);
f3c48ecc	127	ev = (struct proc_event *)msg->data;
e727ca82	128	memset(&ev->event_data, 0, sizeof(ev->event_data));
9f46080c MH	129	ev->what = which_id;
	130	ev->event_data.id.process_pid = task->pid;
	131	ev->event_data.id.process_tgid = task->tgid;
c69e8d9c DH	132	rcu_read_lock();
c69e8d9c DH	133	cred = __task_cred(task);
9f46080c	134	if (which_id == PROC_EVENT_UID) {
9582d901 EB	135	ev->event_data.id.r.ruid = from_kuid_munged(&init_user_ns, cred->uid);
9582d901 EB	136	ev->event_data.id.e.euid = from_kuid_munged(&init_user_ns, cred->euid);
9f46080c	137	} else if (which_id == PROC_EVENT_GID) {
9582d901 EB	138	ev->event_data.id.r.rgid = from_kgid_munged(&init_user_ns, cred->gid);
9582d901 EB	139	ev->event_data.id.e.egid = from_kgid_munged(&init_user_ns, cred->egid);
c69e8d9c DH	140	} else {
c69e8d9c DH	141	rcu_read_unlock();
f3c48ecc	142	return;
c69e8d9c DH	143	}
c69e8d9c DH	144	rcu_read_unlock();
9e93f21b	145	ev->timestamp_ns = ktime_get_ns();
9f46080c MH	146
	147	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
	148	msg->ack = 0; /* not used */
	149	msg->len = sizeof(*ev);
e727ca82	150	msg->flags = 0; /* not used */
ab8ed951	151	send_msg(msg);
9f46080c MH	152	}
9f46080c MH	153
02b51df1 SJR	154	void proc_sid_connector(struct task_struct *task)
	155	{
	156	struct cn_msg *msg;
	157	struct proc_event *ev;
1ca1a4cf	158	__u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
02b51df1 SJR	159
	160	if (atomic_read(&proc_event_num_listeners) < 1)
	161	return;
	162
1ca1a4cf	163	msg = buffer_to_cn_msg(buffer);
02b51df1	164	ev = (struct proc_event *)msg->data;
e727ca82	165	memset(&ev->event_data, 0, sizeof(ev->event_data));
9e93f21b	166	ev->timestamp_ns = ktime_get_ns();
02b51df1 SJR	167	ev->what = PROC_EVENT_SID;
	168	ev->event_data.sid.process_pid = task->pid;
	169	ev->event_data.sid.process_tgid = task->tgid;
	170
	171	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
	172	msg->ack = 0; /* not used */
	173	msg->len = sizeof(*ev);
e727ca82	174	msg->flags = 0; /* not used */
ab8ed951	175	send_msg(msg);
02b51df1 SJR	176	}
02b51df1 SJR	177
f701e5b7 VZ	178	void proc_ptrace_connector(struct task_struct *task, int ptrace_id)
	179	{
	180	struct cn_msg *msg;
	181	struct proc_event *ev;
1ca1a4cf	182	__u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
f701e5b7 VZ	183
	184	if (atomic_read(&proc_event_num_listeners) < 1)
	185	return;
	186
1ca1a4cf	187	msg = buffer_to_cn_msg(buffer);
f701e5b7	188	ev = (struct proc_event *)msg->data;
e727ca82	189	memset(&ev->event_data, 0, sizeof(ev->event_data));
9e93f21b	190	ev->timestamp_ns = ktime_get_ns();
f701e5b7 VZ	191	ev->what = PROC_EVENT_PTRACE;
	192	ev->event_data.ptrace.process_pid = task->pid;
	193	ev->event_data.ptrace.process_tgid = task->tgid;
	194	if (ptrace_id == PTRACE_ATTACH) {
	195	ev->event_data.ptrace.tracer_pid = current->pid;
	196	ev->event_data.ptrace.tracer_tgid = current->tgid;
	197	} else if (ptrace_id == PTRACE_DETACH) {
	198	ev->event_data.ptrace.tracer_pid = 0;
	199	ev->event_data.ptrace.tracer_tgid = 0;
	200	} else
	201	return;
	202
	203	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
	204	msg->ack = 0; /* not used */
	205	msg->len = sizeof(*ev);
e727ca82	206	msg->flags = 0; /* not used */
ab8ed951	207	send_msg(msg);
f701e5b7 VZ	208	}
f701e5b7 VZ	209
f786ecba VZ	210	void proc_comm_connector(struct task_struct *task)
	211	{
	212	struct cn_msg *msg;
	213	struct proc_event *ev;
1ca1a4cf	214	__u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
f786ecba VZ	215
	216	if (atomic_read(&proc_event_num_listeners) < 1)
	217	return;
	218
1ca1a4cf	219	msg = buffer_to_cn_msg(buffer);
f786ecba	220	ev = (struct proc_event *)msg->data;
e727ca82	221	memset(&ev->event_data, 0, sizeof(ev->event_data));
9e93f21b	222	ev->timestamp_ns = ktime_get_ns();
f786ecba VZ	223	ev->what = PROC_EVENT_COMM;
	224	ev->event_data.comm.process_pid = task->pid;
	225	ev->event_data.comm.process_tgid = task->tgid;
	226	get_task_comm(ev->event_data.comm.comm, task);
	227
	228	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
	229	msg->ack = 0; /* not used */
	230	msg->len = sizeof(*ev);
e727ca82	231	msg->flags = 0; /* not used */
ab8ed951	232	send_msg(msg);
2b5faa4c JD	233	}
	234
	235	void proc_coredump_connector(struct task_struct *task)
	236	{
	237	struct cn_msg *msg;
	238	struct proc_event *ev;
6d2b0f02	239	struct task_struct *parent;
1ca1a4cf	240	__u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
2b5faa4c JD	241
	242	if (atomic_read(&proc_event_num_listeners) < 1)
	243	return;
	244
1ca1a4cf	245	msg = buffer_to_cn_msg(buffer);
2b5faa4c	246	ev = (struct proc_event *)msg->data;
e727ca82	247	memset(&ev->event_data, 0, sizeof(ev->event_data));
9e93f21b	248	ev->timestamp_ns = ktime_get_ns();
2b5faa4c JD	249	ev->what = PROC_EVENT_COREDUMP;
	250	ev->event_data.coredump.process_pid = task->pid;
	251	ev->event_data.coredump.process_tgid = task->tgid;
6d2b0f02 LR	252
	253	rcu_read_lock();
	254	if (pid_alive(task)) {
	255	parent = rcu_dereference(task->real_parent);
	256	ev->event_data.coredump.parent_pid = parent->pid;
	257	ev->event_data.coredump.parent_tgid = parent->tgid;
	258	}
	259	rcu_read_unlock();
2b5faa4c JD	260
	261	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
	262	msg->ack = 0; /* not used */
	263	msg->len = sizeof(*ev);
e727ca82	264	msg->flags = 0; /* not used */
ab8ed951	265	send_msg(msg);
f786ecba VZ	266	}
f786ecba VZ	267
9f46080c MH	268	void proc_exit_connector(struct task_struct *task)
	269	{
	270	struct cn_msg *msg;
	271	struct proc_event *ev;
6d2b0f02	272	struct task_struct *parent;
1ca1a4cf	273	__u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
9f46080c MH	274
	275	if (atomic_read(&proc_event_num_listeners) < 1)
	276	return;
	277
1ca1a4cf	278	msg = buffer_to_cn_msg(buffer);
f3c48ecc	279	ev = (struct proc_event *)msg->data;
e727ca82	280	memset(&ev->event_data, 0, sizeof(ev->event_data));
9e93f21b	281	ev->timestamp_ns = ktime_get_ns();
9f46080c MH	282	ev->what = PROC_EVENT_EXIT;
	283	ev->event_data.exit.process_pid = task->pid;
	284	ev->event_data.exit.process_tgid = task->tgid;
	285	ev->event_data.exit.exit_code = task->exit_code;
	286	ev->event_data.exit.exit_signal = task->exit_signal;
6d2b0f02 LR	287
	288	rcu_read_lock();
	289	if (pid_alive(task)) {
	290	parent = rcu_dereference(task->real_parent);
	291	ev->event_data.exit.parent_pid = parent->pid;
	292	ev->event_data.exit.parent_tgid = parent->tgid;
	293	}
	294	rcu_read_unlock();
9f46080c MH	295
	296	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
	297	msg->ack = 0; /* not used */
	298	msg->len = sizeof(*ev);
e727ca82	299	msg->flags = 0; /* not used */
ab8ed951	300	send_msg(msg);
9f46080c MH	301	}
	302
	303	/*
	304	* Send an acknowledgement message to userspace
	305	*
	306	* Use 0 for success, EFOO otherwise.
	307	* Note: this is the negative of conventional kernel error
	308	* values because it's not being returned via syscall return
	309	* mechanisms.
	310	*/
	311	static void cn_proc_ack(int err, int rcvd_seq, int rcvd_ack)
	312	{
	313	struct cn_msg *msg;
	314	struct proc_event *ev;
1ca1a4cf	315	__u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
9f46080c MH	316
	317	if (atomic_read(&proc_event_num_listeners) < 1)
	318	return;
	319
1ca1a4cf	320	msg = buffer_to_cn_msg(buffer);
f3c48ecc	321	ev = (struct proc_event *)msg->data;
e727ca82	322	memset(&ev->event_data, 0, sizeof(ev->event_data));
9f46080c	323	msg->seq = rcvd_seq;
9e93f21b	324	ev->timestamp_ns = ktime_get_ns();
9f46080c MH	325	ev->cpu = -1;
	326	ev->what = PROC_EVENT_NONE;
	327	ev->event_data.ack.err = err;
	328	memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
	329	msg->ack = rcvd_ack + 1;
	330	msg->len = sizeof(*ev);
e727ca82	331	msg->flags = 0; /* not used */
ab8ed951	332	send_msg(msg);
9f46080c MH	333	}
	334
	335	/**
	336	* cn_proc_mcast_ctl
	337	* @data: message sent from userspace via the connector
	338	*/
f0b25932 SB	339	static void cn_proc_mcast_ctl(struct cn_msg *msg,
f0b25932 SB	340	struct netlink_skb_parms *nsp)
9f46080c	341	{
9f46080c MH	342	enum proc_cn_mcast_op *mc_op = NULL;
	343	int err = 0;
	344
	345	if (msg->len != sizeof(*mc_op))
	346	return;
	347
9582d901 EB	348	/*
	349	* Events are reported with respect to the initial pid
	350	* and user namespaces so ignore requestors from
	351	* other namespaces.
	352	*/
	353	if ((current_user_ns() != &init_user_ns) \|\|
	354	(task_active_pid_ns(current) != &init_pid_ns))
	355	return;
	356
e70ab977	357	/* Can only change if privileged. */
90f62cf3	358	if (!__netlink_ns_capable(nsp, &init_user_ns, CAP_NET_ADMIN)) {
e70ab977 KC	359	err = EPERM;
	360	goto out;
	361	}
	362
f3c48ecc	363	mc_op = (enum proc_cn_mcast_op *)msg->data;
9f46080c MH	364	switch (*mc_op) {
	365	case PROC_CN_MCAST_LISTEN:
	366	atomic_inc(&proc_event_num_listeners);
	367	break;
	368	case PROC_CN_MCAST_IGNORE:
	369	atomic_dec(&proc_event_num_listeners);
	370	break;
	371	default:
	372	err = EINVAL;
	373	break;
	374	}
e70ab977 KC	375
e70ab977 KC	376	out:
9f46080c MH	377	cn_proc_ack(err, msg->seq, msg->ack);
	378	}
	379
	380	/*
	381	* cn_proc_init - initialization entry point
	382	*
	383	* Adds the connector callback to the connector driver.
	384	*/
	385	static int __init cn_proc_init(void)
	386	{
f3c48ecc VI	387	int err = cn_add_callback(&cn_proc_event_id,
	388	"cn_proc",
	389	&cn_proc_mcast_ctl);
	390	if (err) {
	391	pr_warn("cn_proc failed to register\n");
9f46080c MH	392	return err;
	393	}
	394	return 0;
	395	}
8297f2d9	396	device_initcall(cn_proc_init);