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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
9f46080c 25#include <linux/kernel.h>
caf3c9dc 26#include <linux/ktime.h>
9f46080c 27#include <linux/init.h>
1d31a4ea 28#include <linux/connector.h>
5a0e3ad6 29#include <linux/gfp.h>
f701e5b7 30#include <linux/ptrace.h>
60063497 31#include <linux/atomic.h>
9582d901 32#include <linux/pid_namespace.h>
60063497 33
9f46080c
MH
34#include <linux/cn_proc.h>
35
1ca1a4cf
CM
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}
9f46080c
MH
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
cc398c2e 55/* proc_event_counts is used as the sequence number of the netlink message */
9f46080c
MH
56static DEFINE_PER_CPU(__u32, proc_event_counts) = { 0 };
57
ab8ed951 58static inline void send_msg(struct cn_msg *msg)
9f46080c 59{
3ea9f683 60 preempt_disable();
ab8ed951
AC
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
3ea9f683 73 preempt_enable();
9f46080c
MH
74}
75
76void proc_fork_connector(struct task_struct *task)
77{
78 struct cn_msg *msg;
79 struct proc_event *ev;
1ca1a4cf 80 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
9e8f90df 81 struct task_struct *parent;
9f46080c
MH
82
83 if (atomic_read(&proc_event_num_listeners) < 1)
84 return;
85
1ca1a4cf 86 msg = buffer_to_cn_msg(buffer);
f3c48ecc 87 ev = (struct proc_event *)msg->data;
e727ca82 88 memset(&ev->event_data, 0, sizeof(ev->event_data));
9e93f21b 89 ev->timestamp_ns = ktime_get_ns();
9f46080c 90 ev->what = PROC_EVENT_FORK;
9e8f90df
ON
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();
9f46080c
MH
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);
e727ca82 102 msg->flags = 0; /* not used */
ab8ed951 103 send_msg(msg);
9f46080c
MH
104}
105
106void proc_exec_connector(struct task_struct *task)
107{
108 struct cn_msg *msg;
109 struct proc_event *ev;
1ca1a4cf 110 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
9f46080c
MH
111
112 if (atomic_read(&proc_event_num_listeners) < 1)
113 return;
114
1ca1a4cf 115 msg = buffer_to_cn_msg(buffer);
f3c48ecc 116 ev = (struct proc_event *)msg->data;
e727ca82 117 memset(&ev->event_data, 0, sizeof(ev->event_data));
9e93f21b 118 ev->timestamp_ns = ktime_get_ns();
9f46080c
MH
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);
e727ca82 126 msg->flags = 0; /* not used */
ab8ed951 127 send_msg(msg);
9f46080c
MH
128}
129
130void proc_id_connector(struct task_struct *task, int which_id)
131{
132 struct cn_msg *msg;
133 struct proc_event *ev;
1ca1a4cf 134 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
c69e8d9c 135 const struct cred *cred;
9f46080c
MH
136
137 if (atomic_read(&proc_event_num_listeners) < 1)
138 return;
139
1ca1a4cf 140 msg = buffer_to_cn_msg(buffer);
f3c48ecc 141 ev = (struct proc_event *)msg->data;
e727ca82 142 memset(&ev->event_data, 0, sizeof(ev->event_data));
9f46080c
MH
143 ev->what = which_id;
144 ev->event_data.id.process_pid = task->pid;
145 ev->event_data.id.process_tgid = task->tgid;
c69e8d9c
DH
146 rcu_read_lock();
147 cred = __task_cred(task);
9f46080c 148 if (which_id == PROC_EVENT_UID) {
9582d901
EB
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);
9f46080c 151 } else if (which_id == PROC_EVENT_GID) {
9582d901
EB
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);
c69e8d9c
DH
154 } else {
155 rcu_read_unlock();
f3c48ecc 156 return;
c69e8d9c
DH
157 }
158 rcu_read_unlock();
9e93f21b 159 ev->timestamp_ns = ktime_get_ns();
9f46080c
MH
160
161 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
162 msg->ack = 0; /* not used */
163 msg->len = sizeof(*ev);
e727ca82 164 msg->flags = 0; /* not used */
ab8ed951 165 send_msg(msg);
9f46080c
MH
166}
167
02b51df1
SJR
168void proc_sid_connector(struct task_struct *task)
169{
170 struct cn_msg *msg;
171 struct proc_event *ev;
1ca1a4cf 172 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
02b51df1
SJR
173
174 if (atomic_read(&proc_event_num_listeners) < 1)
175 return;
176
1ca1a4cf 177 msg = buffer_to_cn_msg(buffer);
02b51df1 178 ev = (struct proc_event *)msg->data;
e727ca82 179 memset(&ev->event_data, 0, sizeof(ev->event_data));
9e93f21b 180 ev->timestamp_ns = ktime_get_ns();
02b51df1
SJR
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);
e727ca82 188 msg->flags = 0; /* not used */
ab8ed951 189 send_msg(msg);
02b51df1
SJR
190}
191
f701e5b7
VZ
192void proc_ptrace_connector(struct task_struct *task, int ptrace_id)
193{
194 struct cn_msg *msg;
195 struct proc_event *ev;
1ca1a4cf 196 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
f701e5b7
VZ
197
198 if (atomic_read(&proc_event_num_listeners) < 1)
199 return;
200
1ca1a4cf 201 msg = buffer_to_cn_msg(buffer);
f701e5b7 202 ev = (struct proc_event *)msg->data;
e727ca82 203 memset(&ev->event_data, 0, sizeof(ev->event_data));
9e93f21b 204 ev->timestamp_ns = ktime_get_ns();
f701e5b7
VZ
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);
e727ca82 220 msg->flags = 0; /* not used */
ab8ed951 221 send_msg(msg);
f701e5b7
VZ
222}
223
f786ecba
VZ
224void proc_comm_connector(struct task_struct *task)
225{
226 struct cn_msg *msg;
227 struct proc_event *ev;
1ca1a4cf 228 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
f786ecba
VZ
229
230 if (atomic_read(&proc_event_num_listeners) < 1)
231 return;
232
1ca1a4cf 233 msg = buffer_to_cn_msg(buffer);
f786ecba 234 ev = (struct proc_event *)msg->data;
e727ca82 235 memset(&ev->event_data, 0, sizeof(ev->event_data));
9e93f21b 236 ev->timestamp_ns = ktime_get_ns();
f786ecba
VZ
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);
e727ca82 245 msg->flags = 0; /* not used */
ab8ed951 246 send_msg(msg);
2b5faa4c
JD
247}
248
249void proc_coredump_connector(struct task_struct *task)
250{
251 struct cn_msg *msg;
252 struct proc_event *ev;
1ca1a4cf 253 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
2b5faa4c
JD
254
255 if (atomic_read(&proc_event_num_listeners) < 1)
256 return;
257
1ca1a4cf 258 msg = buffer_to_cn_msg(buffer);
2b5faa4c 259 ev = (struct proc_event *)msg->data;
e727ca82 260 memset(&ev->event_data, 0, sizeof(ev->event_data));
9e93f21b 261 ev->timestamp_ns = ktime_get_ns();
2b5faa4c
JD
262 ev->what = PROC_EVENT_COREDUMP;
263 ev->event_data.coredump.process_pid = task->pid;
264 ev->event_data.coredump.process_tgid = task->tgid;
b086ff87
SS
265 ev->event_data.coredump.parent_pid = task->real_parent->pid;
266 ev->event_data.coredump.parent_tgid = task->real_parent->tgid;
2b5faa4c
JD
267
268 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
269 msg->ack = 0; /* not used */
270 msg->len = sizeof(*ev);
e727ca82 271 msg->flags = 0; /* not used */
ab8ed951 272 send_msg(msg);
f786ecba
VZ
273}
274
9f46080c
MH
275void proc_exit_connector(struct task_struct *task)
276{
277 struct cn_msg *msg;
278 struct proc_event *ev;
1ca1a4cf 279 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
9f46080c
MH
280
281 if (atomic_read(&proc_event_num_listeners) < 1)
282 return;
283
1ca1a4cf 284 msg = buffer_to_cn_msg(buffer);
f3c48ecc 285 ev = (struct proc_event *)msg->data;
e727ca82 286 memset(&ev->event_data, 0, sizeof(ev->event_data));
9e93f21b 287 ev->timestamp_ns = ktime_get_ns();
9f46080c
MH
288 ev->what = PROC_EVENT_EXIT;
289 ev->event_data.exit.process_pid = task->pid;
290 ev->event_data.exit.process_tgid = task->tgid;
291 ev->event_data.exit.exit_code = task->exit_code;
292 ev->event_data.exit.exit_signal = task->exit_signal;
b086ff87
SS
293 ev->event_data.exit.parent_pid = task->real_parent->pid;
294 ev->event_data.exit.parent_tgid = task->real_parent->tgid;
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 */
311static 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
339static void cn_proc_mcast_ctl(struct cn_msg *msg,
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
376out:
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 */
385static 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 396device_initcall(cn_proc_init);