Loading...
1// SPDX-License-Identifier: GPL-2.0-or-later
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.
9 */
10
11#include <linux/kernel.h>
12#include <linux/ktime.h>
13#include <linux/init.h>
14#include <linux/connector.h>
15#include <linux/gfp.h>
16#include <linux/ptrace.h>
17#include <linux/atomic.h>
18#include <linux/pid_namespace.h>
19
20#include <linux/cn_proc.h>
21#include <linux/local_lock.h>
22
23/*
24 * Size of a cn_msg followed by a proc_event structure. Since the
25 * sizeof struct cn_msg is a multiple of 4 bytes, but not 8 bytes, we
26 * add one 4-byte word to the size here, and then start the actual
27 * cn_msg structure 4 bytes into the stack buffer. The result is that
28 * the immediately following proc_event structure is aligned to 8 bytes.
29 */
30#define CN_PROC_MSG_SIZE (sizeof(struct cn_msg) + sizeof(struct proc_event) + 4)
31
32/* See comment above; we test our assumption about sizeof struct cn_msg here. */
33static inline struct cn_msg *buffer_to_cn_msg(__u8 *buffer)
34{
35 BUILD_BUG_ON(sizeof(struct cn_msg) != 20);
36 return (struct cn_msg *)(buffer + 4);
37}
38
39static atomic_t proc_event_num_listeners = ATOMIC_INIT(0);
40static struct cb_id cn_proc_event_id = { CN_IDX_PROC, CN_VAL_PROC };
41
42/* local_event.count is used as the sequence number of the netlink message */
43struct local_event {
44 local_lock_t lock;
45 __u32 count;
46};
47static DEFINE_PER_CPU(struct local_event, local_event) = {
48 .lock = INIT_LOCAL_LOCK(lock),
49};
50
51static inline void send_msg(struct cn_msg *msg)
52{
53 local_lock(&local_event.lock);
54
55 msg->seq = __this_cpu_inc_return(local_event.count) - 1;
56 ((struct proc_event *)msg->data)->cpu = smp_processor_id();
57
58 /*
59 * local_lock() disables preemption during send to ensure the messages
60 * are ordered according to their sequence numbers.
61 *
62 * If cn_netlink_send() fails, the data is not sent.
63 */
64 cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_NOWAIT);
65
66 local_unlock(&local_event.lock);
67}
68
69void proc_fork_connector(struct task_struct *task)
70{
71 struct cn_msg *msg;
72 struct proc_event *ev;
73 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
74 struct task_struct *parent;
75
76 if (atomic_read(&proc_event_num_listeners) < 1)
77 return;
78
79 msg = buffer_to_cn_msg(buffer);
80 ev = (struct proc_event *)msg->data;
81 memset(&ev->event_data, 0, sizeof(ev->event_data));
82 ev->timestamp_ns = ktime_get_ns();
83 ev->what = PROC_EVENT_FORK;
84 rcu_read_lock();
85 parent = rcu_dereference(task->real_parent);
86 ev->event_data.fork.parent_pid = parent->pid;
87 ev->event_data.fork.parent_tgid = parent->tgid;
88 rcu_read_unlock();
89 ev->event_data.fork.child_pid = task->pid;
90 ev->event_data.fork.child_tgid = task->tgid;
91
92 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
93 msg->ack = 0; /* not used */
94 msg->len = sizeof(*ev);
95 msg->flags = 0; /* not used */
96 send_msg(msg);
97}
98
99void proc_exec_connector(struct task_struct *task)
100{
101 struct cn_msg *msg;
102 struct proc_event *ev;
103 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
104
105 if (atomic_read(&proc_event_num_listeners) < 1)
106 return;
107
108 msg = buffer_to_cn_msg(buffer);
109 ev = (struct proc_event *)msg->data;
110 memset(&ev->event_data, 0, sizeof(ev->event_data));
111 ev->timestamp_ns = ktime_get_ns();
112 ev->what = PROC_EVENT_EXEC;
113 ev->event_data.exec.process_pid = task->pid;
114 ev->event_data.exec.process_tgid = task->tgid;
115
116 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
117 msg->ack = 0; /* not used */
118 msg->len = sizeof(*ev);
119 msg->flags = 0; /* not used */
120 send_msg(msg);
121}
122
123void proc_id_connector(struct task_struct *task, int which_id)
124{
125 struct cn_msg *msg;
126 struct proc_event *ev;
127 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
128 const struct cred *cred;
129
130 if (atomic_read(&proc_event_num_listeners) < 1)
131 return;
132
133 msg = buffer_to_cn_msg(buffer);
134 ev = (struct proc_event *)msg->data;
135 memset(&ev->event_data, 0, sizeof(ev->event_data));
136 ev->what = which_id;
137 ev->event_data.id.process_pid = task->pid;
138 ev->event_data.id.process_tgid = task->tgid;
139 rcu_read_lock();
140 cred = __task_cred(task);
141 if (which_id == PROC_EVENT_UID) {
142 ev->event_data.id.r.ruid = from_kuid_munged(&init_user_ns, cred->uid);
143 ev->event_data.id.e.euid = from_kuid_munged(&init_user_ns, cred->euid);
144 } else if (which_id == PROC_EVENT_GID) {
145 ev->event_data.id.r.rgid = from_kgid_munged(&init_user_ns, cred->gid);
146 ev->event_data.id.e.egid = from_kgid_munged(&init_user_ns, cred->egid);
147 } else {
148 rcu_read_unlock();
149 return;
150 }
151 rcu_read_unlock();
152 ev->timestamp_ns = ktime_get_ns();
153
154 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
155 msg->ack = 0; /* not used */
156 msg->len = sizeof(*ev);
157 msg->flags = 0; /* not used */
158 send_msg(msg);
159}
160
161void proc_sid_connector(struct task_struct *task)
162{
163 struct cn_msg *msg;
164 struct proc_event *ev;
165 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
166
167 if (atomic_read(&proc_event_num_listeners) < 1)
168 return;
169
170 msg = buffer_to_cn_msg(buffer);
171 ev = (struct proc_event *)msg->data;
172 memset(&ev->event_data, 0, sizeof(ev->event_data));
173 ev->timestamp_ns = ktime_get_ns();
174 ev->what = PROC_EVENT_SID;
175 ev->event_data.sid.process_pid = task->pid;
176 ev->event_data.sid.process_tgid = task->tgid;
177
178 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
179 msg->ack = 0; /* not used */
180 msg->len = sizeof(*ev);
181 msg->flags = 0; /* not used */
182 send_msg(msg);
183}
184
185void proc_ptrace_connector(struct task_struct *task, int ptrace_id)
186{
187 struct cn_msg *msg;
188 struct proc_event *ev;
189 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
190
191 if (atomic_read(&proc_event_num_listeners) < 1)
192 return;
193
194 msg = buffer_to_cn_msg(buffer);
195 ev = (struct proc_event *)msg->data;
196 memset(&ev->event_data, 0, sizeof(ev->event_data));
197 ev->timestamp_ns = ktime_get_ns();
198 ev->what = PROC_EVENT_PTRACE;
199 ev->event_data.ptrace.process_pid = task->pid;
200 ev->event_data.ptrace.process_tgid = task->tgid;
201 if (ptrace_id == PTRACE_ATTACH) {
202 ev->event_data.ptrace.tracer_pid = current->pid;
203 ev->event_data.ptrace.tracer_tgid = current->tgid;
204 } else if (ptrace_id == PTRACE_DETACH) {
205 ev->event_data.ptrace.tracer_pid = 0;
206 ev->event_data.ptrace.tracer_tgid = 0;
207 } else
208 return;
209
210 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
211 msg->ack = 0; /* not used */
212 msg->len = sizeof(*ev);
213 msg->flags = 0; /* not used */
214 send_msg(msg);
215}
216
217void proc_comm_connector(struct task_struct *task)
218{
219 struct cn_msg *msg;
220 struct proc_event *ev;
221 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
222
223 if (atomic_read(&proc_event_num_listeners) < 1)
224 return;
225
226 msg = buffer_to_cn_msg(buffer);
227 ev = (struct proc_event *)msg->data;
228 memset(&ev->event_data, 0, sizeof(ev->event_data));
229 ev->timestamp_ns = ktime_get_ns();
230 ev->what = PROC_EVENT_COMM;
231 ev->event_data.comm.process_pid = task->pid;
232 ev->event_data.comm.process_tgid = task->tgid;
233 get_task_comm(ev->event_data.comm.comm, task);
234
235 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
236 msg->ack = 0; /* not used */
237 msg->len = sizeof(*ev);
238 msg->flags = 0; /* not used */
239 send_msg(msg);
240}
241
242void proc_coredump_connector(struct task_struct *task)
243{
244 struct cn_msg *msg;
245 struct proc_event *ev;
246 struct task_struct *parent;
247 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
248
249 if (atomic_read(&proc_event_num_listeners) < 1)
250 return;
251
252 msg = buffer_to_cn_msg(buffer);
253 ev = (struct proc_event *)msg->data;
254 memset(&ev->event_data, 0, sizeof(ev->event_data));
255 ev->timestamp_ns = ktime_get_ns();
256 ev->what = PROC_EVENT_COREDUMP;
257 ev->event_data.coredump.process_pid = task->pid;
258 ev->event_data.coredump.process_tgid = task->tgid;
259
260 rcu_read_lock();
261 if (pid_alive(task)) {
262 parent = rcu_dereference(task->real_parent);
263 ev->event_data.coredump.parent_pid = parent->pid;
264 ev->event_data.coredump.parent_tgid = parent->tgid;
265 }
266 rcu_read_unlock();
267
268 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
269 msg->ack = 0; /* not used */
270 msg->len = sizeof(*ev);
271 msg->flags = 0; /* not used */
272 send_msg(msg);
273}
274
275void proc_exit_connector(struct task_struct *task)
276{
277 struct cn_msg *msg;
278 struct proc_event *ev;
279 struct task_struct *parent;
280 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
281
282 if (atomic_read(&proc_event_num_listeners) < 1)
283 return;
284
285 msg = buffer_to_cn_msg(buffer);
286 ev = (struct proc_event *)msg->data;
287 memset(&ev->event_data, 0, sizeof(ev->event_data));
288 ev->timestamp_ns = ktime_get_ns();
289 ev->what = PROC_EVENT_EXIT;
290 ev->event_data.exit.process_pid = task->pid;
291 ev->event_data.exit.process_tgid = task->tgid;
292 ev->event_data.exit.exit_code = task->exit_code;
293 ev->event_data.exit.exit_signal = task->exit_signal;
294
295 rcu_read_lock();
296 if (pid_alive(task)) {
297 parent = rcu_dereference(task->real_parent);
298 ev->event_data.exit.parent_pid = parent->pid;
299 ev->event_data.exit.parent_tgid = parent->tgid;
300 }
301 rcu_read_unlock();
302
303 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
304 msg->ack = 0; /* not used */
305 msg->len = sizeof(*ev);
306 msg->flags = 0; /* not used */
307 send_msg(msg);
308}
309
310/*
311 * Send an acknowledgement message to userspace
312 *
313 * Use 0 for success, EFOO otherwise.
314 * Note: this is the negative of conventional kernel error
315 * values because it's not being returned via syscall return
316 * mechanisms.
317 */
318static void cn_proc_ack(int err, int rcvd_seq, int rcvd_ack)
319{
320 struct cn_msg *msg;
321 struct proc_event *ev;
322 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
323
324 if (atomic_read(&proc_event_num_listeners) < 1)
325 return;
326
327 msg = buffer_to_cn_msg(buffer);
328 ev = (struct proc_event *)msg->data;
329 memset(&ev->event_data, 0, sizeof(ev->event_data));
330 msg->seq = rcvd_seq;
331 ev->timestamp_ns = ktime_get_ns();
332 ev->cpu = -1;
333 ev->what = PROC_EVENT_NONE;
334 ev->event_data.ack.err = err;
335 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
336 msg->ack = rcvd_ack + 1;
337 msg->len = sizeof(*ev);
338 msg->flags = 0; /* not used */
339 send_msg(msg);
340}
341
342/**
343 * cn_proc_mcast_ctl
344 * @data: message sent from userspace via the connector
345 */
346static void cn_proc_mcast_ctl(struct cn_msg *msg,
347 struct netlink_skb_parms *nsp)
348{
349 enum proc_cn_mcast_op *mc_op = NULL;
350 int err = 0;
351
352 if (msg->len != sizeof(*mc_op))
353 return;
354
355 /*
356 * Events are reported with respect to the initial pid
357 * and user namespaces so ignore requestors from
358 * other namespaces.
359 */
360 if ((current_user_ns() != &init_user_ns) ||
361 !task_is_in_init_pid_ns(current))
362 return;
363
364 /* Can only change if privileged. */
365 if (!__netlink_ns_capable(nsp, &init_user_ns, CAP_NET_ADMIN)) {
366 err = EPERM;
367 goto out;
368 }
369
370 mc_op = (enum proc_cn_mcast_op *)msg->data;
371 switch (*mc_op) {
372 case PROC_CN_MCAST_LISTEN:
373 atomic_inc(&proc_event_num_listeners);
374 break;
375 case PROC_CN_MCAST_IGNORE:
376 atomic_dec(&proc_event_num_listeners);
377 break;
378 default:
379 err = EINVAL;
380 break;
381 }
382
383out:
384 cn_proc_ack(err, msg->seq, msg->ack);
385}
386
387/*
388 * cn_proc_init - initialization entry point
389 *
390 * Adds the connector callback to the connector driver.
391 */
392static int __init cn_proc_init(void)
393{
394 int err = cn_add_callback(&cn_proc_event_id,
395 "cn_proc",
396 &cn_proc_mcast_ctl);
397 if (err) {
398 pr_warn("cn_proc failed to register\n");
399 return err;
400 }
401 return 0;
402}
403device_initcall(cn_proc_init);
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/kernel.h>
26#include <linux/ktime.h>
27#include <linux/init.h>
28#include <linux/connector.h>
29#include <linux/gfp.h>
30#include <linux/ptrace.h>
31#include <linux/atomic.h>
32#include <linux/pid_namespace.h>
33
34#include <linux/cn_proc.h>
35
36/*
37 * Size of a cn_msg followed by a proc_event structure. Since the
38 * sizeof struct cn_msg is a multiple of 4 bytes, but not 8 bytes, we
39 * add one 4-byte word to the size here, and then start the actual
40 * cn_msg structure 4 bytes into the stack buffer. The result is that
41 * the immediately following proc_event structure is aligned to 8 bytes.
42 */
43#define CN_PROC_MSG_SIZE (sizeof(struct cn_msg) + sizeof(struct proc_event) + 4)
44
45/* See comment above; we test our assumption about sizeof struct cn_msg here. */
46static inline struct cn_msg *buffer_to_cn_msg(__u8 *buffer)
47{
48 BUILD_BUG_ON(sizeof(struct cn_msg) != 20);
49 return (struct cn_msg *)(buffer + 4);
50}
51
52static atomic_t proc_event_num_listeners = ATOMIC_INIT(0);
53static struct cb_id cn_proc_event_id = { CN_IDX_PROC, CN_VAL_PROC };
54
55/* proc_event_counts is used as the sequence number of the netlink message */
56static DEFINE_PER_CPU(__u32, proc_event_counts) = { 0 };
57
58static inline void send_msg(struct cn_msg *msg)
59{
60 preempt_disable();
61
62 msg->seq = __this_cpu_inc_return(proc_event_counts) - 1;
63 ((struct proc_event *)msg->data)->cpu = smp_processor_id();
64
65 /*
66 * Preemption remains disabled during send to ensure the messages are
67 * ordered according to their sequence numbers.
68 *
69 * If cn_netlink_send() fails, the data is not sent.
70 */
71 cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_NOWAIT);
72
73 preempt_enable();
74}
75
76void proc_fork_connector(struct task_struct *task)
77{
78 struct cn_msg *msg;
79 struct proc_event *ev;
80 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
81 struct task_struct *parent;
82
83 if (atomic_read(&proc_event_num_listeners) < 1)
84 return;
85
86 msg = buffer_to_cn_msg(buffer);
87 ev = (struct proc_event *)msg->data;
88 memset(&ev->event_data, 0, sizeof(ev->event_data));
89 ev->timestamp_ns = ktime_get_ns();
90 ev->what = PROC_EVENT_FORK;
91 rcu_read_lock();
92 parent = rcu_dereference(task->real_parent);
93 ev->event_data.fork.parent_pid = parent->pid;
94 ev->event_data.fork.parent_tgid = parent->tgid;
95 rcu_read_unlock();
96 ev->event_data.fork.child_pid = task->pid;
97 ev->event_data.fork.child_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 msg->flags = 0; /* not used */
103 send_msg(msg);
104}
105
106void proc_exec_connector(struct task_struct *task)
107{
108 struct cn_msg *msg;
109 struct proc_event *ev;
110 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
111
112 if (atomic_read(&proc_event_num_listeners) < 1)
113 return;
114
115 msg = buffer_to_cn_msg(buffer);
116 ev = (struct proc_event *)msg->data;
117 memset(&ev->event_data, 0, sizeof(ev->event_data));
118 ev->timestamp_ns = ktime_get_ns();
119 ev->what = PROC_EVENT_EXEC;
120 ev->event_data.exec.process_pid = task->pid;
121 ev->event_data.exec.process_tgid = task->tgid;
122
123 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
124 msg->ack = 0; /* not used */
125 msg->len = sizeof(*ev);
126 msg->flags = 0; /* not used */
127 send_msg(msg);
128}
129
130void proc_id_connector(struct task_struct *task, int which_id)
131{
132 struct cn_msg *msg;
133 struct proc_event *ev;
134 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
135 const struct cred *cred;
136
137 if (atomic_read(&proc_event_num_listeners) < 1)
138 return;
139
140 msg = buffer_to_cn_msg(buffer);
141 ev = (struct proc_event *)msg->data;
142 memset(&ev->event_data, 0, sizeof(ev->event_data));
143 ev->what = which_id;
144 ev->event_data.id.process_pid = task->pid;
145 ev->event_data.id.process_tgid = task->tgid;
146 rcu_read_lock();
147 cred = __task_cred(task);
148 if (which_id == PROC_EVENT_UID) {
149 ev->event_data.id.r.ruid = from_kuid_munged(&init_user_ns, cred->uid);
150 ev->event_data.id.e.euid = from_kuid_munged(&init_user_ns, cred->euid);
151 } else if (which_id == PROC_EVENT_GID) {
152 ev->event_data.id.r.rgid = from_kgid_munged(&init_user_ns, cred->gid);
153 ev->event_data.id.e.egid = from_kgid_munged(&init_user_ns, cred->egid);
154 } else {
155 rcu_read_unlock();
156 return;
157 }
158 rcu_read_unlock();
159 ev->timestamp_ns = ktime_get_ns();
160
161 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
162 msg->ack = 0; /* not used */
163 msg->len = sizeof(*ev);
164 msg->flags = 0; /* not used */
165 send_msg(msg);
166}
167
168void proc_sid_connector(struct task_struct *task)
169{
170 struct cn_msg *msg;
171 struct proc_event *ev;
172 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
173
174 if (atomic_read(&proc_event_num_listeners) < 1)
175 return;
176
177 msg = buffer_to_cn_msg(buffer);
178 ev = (struct proc_event *)msg->data;
179 memset(&ev->event_data, 0, sizeof(ev->event_data));
180 ev->timestamp_ns = ktime_get_ns();
181 ev->what = PROC_EVENT_SID;
182 ev->event_data.sid.process_pid = task->pid;
183 ev->event_data.sid.process_tgid = task->tgid;
184
185 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
186 msg->ack = 0; /* not used */
187 msg->len = sizeof(*ev);
188 msg->flags = 0; /* not used */
189 send_msg(msg);
190}
191
192void proc_ptrace_connector(struct task_struct *task, int ptrace_id)
193{
194 struct cn_msg *msg;
195 struct proc_event *ev;
196 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
197
198 if (atomic_read(&proc_event_num_listeners) < 1)
199 return;
200
201 msg = buffer_to_cn_msg(buffer);
202 ev = (struct proc_event *)msg->data;
203 memset(&ev->event_data, 0, sizeof(ev->event_data));
204 ev->timestamp_ns = ktime_get_ns();
205 ev->what = PROC_EVENT_PTRACE;
206 ev->event_data.ptrace.process_pid = task->pid;
207 ev->event_data.ptrace.process_tgid = task->tgid;
208 if (ptrace_id == PTRACE_ATTACH) {
209 ev->event_data.ptrace.tracer_pid = current->pid;
210 ev->event_data.ptrace.tracer_tgid = current->tgid;
211 } else if (ptrace_id == PTRACE_DETACH) {
212 ev->event_data.ptrace.tracer_pid = 0;
213 ev->event_data.ptrace.tracer_tgid = 0;
214 } else
215 return;
216
217 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
218 msg->ack = 0; /* not used */
219 msg->len = sizeof(*ev);
220 msg->flags = 0; /* not used */
221 send_msg(msg);
222}
223
224void proc_comm_connector(struct task_struct *task)
225{
226 struct cn_msg *msg;
227 struct proc_event *ev;
228 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
229
230 if (atomic_read(&proc_event_num_listeners) < 1)
231 return;
232
233 msg = buffer_to_cn_msg(buffer);
234 ev = (struct proc_event *)msg->data;
235 memset(&ev->event_data, 0, sizeof(ev->event_data));
236 ev->timestamp_ns = ktime_get_ns();
237 ev->what = PROC_EVENT_COMM;
238 ev->event_data.comm.process_pid = task->pid;
239 ev->event_data.comm.process_tgid = task->tgid;
240 get_task_comm(ev->event_data.comm.comm, task);
241
242 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
243 msg->ack = 0; /* not used */
244 msg->len = sizeof(*ev);
245 msg->flags = 0; /* not used */
246 send_msg(msg);
247}
248
249void proc_coredump_connector(struct task_struct *task)
250{
251 struct cn_msg *msg;
252 struct proc_event *ev;
253 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
254
255 if (atomic_read(&proc_event_num_listeners) < 1)
256 return;
257
258 msg = buffer_to_cn_msg(buffer);
259 ev = (struct proc_event *)msg->data;
260 memset(&ev->event_data, 0, sizeof(ev->event_data));
261 ev->timestamp_ns = ktime_get_ns();
262 ev->what = PROC_EVENT_COREDUMP;
263 ev->event_data.coredump.process_pid = task->pid;
264 ev->event_data.coredump.process_tgid = task->tgid;
265
266 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
267 msg->ack = 0; /* not used */
268 msg->len = sizeof(*ev);
269 msg->flags = 0; /* not used */
270 send_msg(msg);
271}
272
273void proc_exit_connector(struct task_struct *task)
274{
275 struct cn_msg *msg;
276 struct proc_event *ev;
277 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
278
279 if (atomic_read(&proc_event_num_listeners) < 1)
280 return;
281
282 msg = buffer_to_cn_msg(buffer);
283 ev = (struct proc_event *)msg->data;
284 memset(&ev->event_data, 0, sizeof(ev->event_data));
285 ev->timestamp_ns = ktime_get_ns();
286 ev->what = PROC_EVENT_EXIT;
287 ev->event_data.exit.process_pid = task->pid;
288 ev->event_data.exit.process_tgid = task->tgid;
289 ev->event_data.exit.exit_code = task->exit_code;
290 ev->event_data.exit.exit_signal = task->exit_signal;
291
292 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
293 msg->ack = 0; /* not used */
294 msg->len = sizeof(*ev);
295 msg->flags = 0; /* not used */
296 send_msg(msg);
297}
298
299/*
300 * Send an acknowledgement message to userspace
301 *
302 * Use 0 for success, EFOO otherwise.
303 * Note: this is the negative of conventional kernel error
304 * values because it's not being returned via syscall return
305 * mechanisms.
306 */
307static void cn_proc_ack(int err, int rcvd_seq, int rcvd_ack)
308{
309 struct cn_msg *msg;
310 struct proc_event *ev;
311 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
312
313 if (atomic_read(&proc_event_num_listeners) < 1)
314 return;
315
316 msg = buffer_to_cn_msg(buffer);
317 ev = (struct proc_event *)msg->data;
318 memset(&ev->event_data, 0, sizeof(ev->event_data));
319 msg->seq = rcvd_seq;
320 ev->timestamp_ns = ktime_get_ns();
321 ev->cpu = -1;
322 ev->what = PROC_EVENT_NONE;
323 ev->event_data.ack.err = err;
324 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
325 msg->ack = rcvd_ack + 1;
326 msg->len = sizeof(*ev);
327 msg->flags = 0; /* not used */
328 send_msg(msg);
329}
330
331/**
332 * cn_proc_mcast_ctl
333 * @data: message sent from userspace via the connector
334 */
335static void cn_proc_mcast_ctl(struct cn_msg *msg,
336 struct netlink_skb_parms *nsp)
337{
338 enum proc_cn_mcast_op *mc_op = NULL;
339 int err = 0;
340
341 if (msg->len != sizeof(*mc_op))
342 return;
343
344 /*
345 * Events are reported with respect to the initial pid
346 * and user namespaces so ignore requestors from
347 * other namespaces.
348 */
349 if ((current_user_ns() != &init_user_ns) ||
350 (task_active_pid_ns(current) != &init_pid_ns))
351 return;
352
353 /* Can only change if privileged. */
354 if (!__netlink_ns_capable(nsp, &init_user_ns, CAP_NET_ADMIN)) {
355 err = EPERM;
356 goto out;
357 }
358
359 mc_op = (enum proc_cn_mcast_op *)msg->data;
360 switch (*mc_op) {
361 case PROC_CN_MCAST_LISTEN:
362 atomic_inc(&proc_event_num_listeners);
363 break;
364 case PROC_CN_MCAST_IGNORE:
365 atomic_dec(&proc_event_num_listeners);
366 break;
367 default:
368 err = EINVAL;
369 break;
370 }
371
372out:
373 cn_proc_ack(err, msg->seq, msg->ack);
374}
375
376/*
377 * cn_proc_init - initialization entry point
378 *
379 * Adds the connector callback to the connector driver.
380 */
381static int __init cn_proc_init(void)
382{
383 int err = cn_add_callback(&cn_proc_event_id,
384 "cn_proc",
385 &cn_proc_mcast_ctl);
386 if (err) {
387 pr_warn("cn_proc failed to register\n");
388 return err;
389 }
390 return 0;
391}
392device_initcall(cn_proc_init);