summaryrefslogtreecommitdiffstats
path: root/drivers/connector/cn_proc.c
blob: c73fc2b74de2a1dd0665bde5693b1fce03f6d6c5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
/*
 * 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 <linux/pid_namespace.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;
	memset(&ev->event_data, 0, sizeof(ev->event_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);
	msg->flags = 0; /* not used */
	/*  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;
	memset(&ev->event_data, 0, sizeof(ev->event_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);
	msg->flags = 0; /* not used */
	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;
	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();
	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);
	msg->flags = 0; /* not used */
	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;
	memset(&ev->event_data, 0, sizeof(ev->event_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);
	msg->flags = 0; /* not used */
	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;
	memset(&ev->event_data, 0, sizeof(ev->event_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);
	msg->flags = 0; /* not used */
	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;
	memset(&ev->event_data, 0, sizeof(ev->event_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);
	msg->flags = 0; /* not used */
	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
}

void proc_coredump_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;
	memset(&ev->event_data, 0, sizeof(ev->event_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_COREDUMP;
	ev->event_data.coredump.process_pid = task->pid;
	ev->event_data.coredump.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 */
	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;
	memset(&ev->event_data, 0, sizeof(ev->event_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);
	msg->flags = 0; /* not used */
	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;
	memset(&ev->event_data, 0, sizeof(ev->event_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);
	msg->flags = 0; /* not used */
	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;

	/* 
	 * 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 (!capable(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;
}

module_init(cn_proc_init);
OpenPOWER on IntegriCloud