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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. */ | |
46 | static 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 | |
52 | static atomic_t proc_event_num_listeners = ATOMIC_INIT(0); | |
53 | static 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 |
56 | static DEFINE_PER_CPU(__u32, proc_event_counts) = { 0 }; |
57 | ||
ab8ed951 | 58 | static 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 | ||
76 | void 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 | ||
106 | void 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 | ||
130 | void 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 |
168 | void 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 |
192 | void 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 |
224 | void 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 | ||
249 | void 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; | |
265 | ||
266 | memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); | |
267 | msg->ack = 0; /* not used */ | |
268 | msg->len = sizeof(*ev); | |
e727ca82 | 269 | msg->flags = 0; /* not used */ |
ab8ed951 | 270 | send_msg(msg); |
f786ecba VZ |
271 | } |
272 | ||
9f46080c MH |
273 | void proc_exit_connector(struct task_struct *task) |
274 | { | |
275 | struct cn_msg *msg; | |
276 | struct proc_event *ev; | |
1ca1a4cf | 277 | __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8); |
9f46080c MH |
278 | |
279 | if (atomic_read(&proc_event_num_listeners) < 1) | |
280 | return; | |
281 | ||
1ca1a4cf | 282 | msg = buffer_to_cn_msg(buffer); |
f3c48ecc | 283 | ev = (struct proc_event *)msg->data; |
e727ca82 | 284 | memset(&ev->event_data, 0, sizeof(ev->event_data)); |
9e93f21b | 285 | ev->timestamp_ns = ktime_get_ns(); |
9f46080c MH |
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); | |
e727ca82 | 295 | msg->flags = 0; /* not used */ |
ab8ed951 | 296 | send_msg(msg); |
9f46080c MH |
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 | */ | |
307 | static void cn_proc_ack(int err, int rcvd_seq, int rcvd_ack) | |
308 | { | |
309 | struct cn_msg *msg; | |
310 | struct proc_event *ev; | |
1ca1a4cf | 311 | __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8); |
9f46080c MH |
312 | |
313 | if (atomic_read(&proc_event_num_listeners) < 1) | |
314 | return; | |
315 | ||
1ca1a4cf | 316 | msg = buffer_to_cn_msg(buffer); |
f3c48ecc | 317 | ev = (struct proc_event *)msg->data; |
e727ca82 | 318 | memset(&ev->event_data, 0, sizeof(ev->event_data)); |
9f46080c | 319 | msg->seq = rcvd_seq; |
9e93f21b | 320 | ev->timestamp_ns = ktime_get_ns(); |
9f46080c MH |
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); | |
e727ca82 | 327 | msg->flags = 0; /* not used */ |
ab8ed951 | 328 | send_msg(msg); |
9f46080c MH |
329 | } |
330 | ||
331 | /** | |
332 | * cn_proc_mcast_ctl | |
333 | * @data: message sent from userspace via the connector | |
334 | */ | |
f0b25932 SB |
335 | static void cn_proc_mcast_ctl(struct cn_msg *msg, |
336 | struct netlink_skb_parms *nsp) | |
9f46080c | 337 | { |
9f46080c MH |
338 | enum proc_cn_mcast_op *mc_op = NULL; |
339 | int err = 0; | |
340 | ||
341 | if (msg->len != sizeof(*mc_op)) | |
342 | return; | |
343 | ||
9582d901 EB |
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 | ||
e70ab977 | 353 | /* Can only change if privileged. */ |
90f62cf3 | 354 | if (!__netlink_ns_capable(nsp, &init_user_ns, CAP_NET_ADMIN)) { |
e70ab977 KC |
355 | err = EPERM; |
356 | goto out; | |
357 | } | |
358 | ||
f3c48ecc | 359 | mc_op = (enum proc_cn_mcast_op *)msg->data; |
9f46080c MH |
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 | } | |
e70ab977 KC |
371 | |
372 | out: | |
9f46080c MH |
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 | */ | |
381 | static int __init cn_proc_init(void) | |
382 | { | |
f3c48ecc VI |
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"); | |
9f46080c MH |
388 | return err; |
389 | } | |
390 | return 0; | |
391 | } | |
8297f2d9 | 392 | device_initcall(cn_proc_init); |