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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 | ||
25 | #include <linux/module.h> | |
26 | #include <linux/kernel.h> | |
caf3c9dc | 27 | #include <linux/ktime.h> |
9f46080c | 28 | #include <linux/init.h> |
1d31a4ea | 29 | #include <linux/connector.h> |
5a0e3ad6 | 30 | #include <linux/gfp.h> |
f701e5b7 | 31 | #include <linux/ptrace.h> |
60063497 | 32 | #include <linux/atomic.h> |
9582d901 | 33 | #include <linux/pid_namespace.h> |
60063497 | 34 | |
9f46080c MH |
35 | #include <linux/cn_proc.h> |
36 | ||
1ca1a4cf CM |
37 | /* |
38 | * Size of a cn_msg followed by a proc_event structure. Since the | |
39 | * sizeof struct cn_msg is a multiple of 4 bytes, but not 8 bytes, we | |
40 | * add one 4-byte word to the size here, and then start the actual | |
41 | * cn_msg structure 4 bytes into the stack buffer. The result is that | |
42 | * the immediately following proc_event structure is aligned to 8 bytes. | |
43 | */ | |
44 | #define CN_PROC_MSG_SIZE (sizeof(struct cn_msg) + sizeof(struct proc_event) + 4) | |
45 | ||
46 | /* See comment above; we test our assumption about sizeof struct cn_msg here. */ | |
47 | static inline struct cn_msg *buffer_to_cn_msg(__u8 *buffer) | |
48 | { | |
49 | BUILD_BUG_ON(sizeof(struct cn_msg) != 20); | |
50 | return (struct cn_msg *)(buffer + 4); | |
51 | } | |
9f46080c MH |
52 | |
53 | static atomic_t proc_event_num_listeners = ATOMIC_INIT(0); | |
54 | static struct cb_id cn_proc_event_id = { CN_IDX_PROC, CN_VAL_PROC }; | |
55 | ||
cc398c2e | 56 | /* proc_event_counts is used as the sequence number of the netlink message */ |
9f46080c MH |
57 | static DEFINE_PER_CPU(__u32, proc_event_counts) = { 0 }; |
58 | ||
59 | static inline void get_seq(__u32 *ts, int *cpu) | |
60 | { | |
3ea9f683 | 61 | preempt_disable(); |
f3c48ecc | 62 | *ts = __this_cpu_inc_return(proc_event_counts) - 1; |
9f46080c | 63 | *cpu = smp_processor_id(); |
3ea9f683 | 64 | preempt_enable(); |
9f46080c MH |
65 | } |
66 | ||
67 | void proc_fork_connector(struct task_struct *task) | |
68 | { | |
69 | struct cn_msg *msg; | |
70 | struct proc_event *ev; | |
1ca1a4cf | 71 | __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8); |
9e8f90df | 72 | struct task_struct *parent; |
9f46080c MH |
73 | |
74 | if (atomic_read(&proc_event_num_listeners) < 1) | |
75 | return; | |
76 | ||
1ca1a4cf | 77 | msg = buffer_to_cn_msg(buffer); |
f3c48ecc | 78 | ev = (struct proc_event *)msg->data; |
e727ca82 | 79 | memset(&ev->event_data, 0, sizeof(ev->event_data)); |
9f46080c | 80 | get_seq(&msg->seq, &ev->cpu); |
9e93f21b | 81 | ev->timestamp_ns = ktime_get_ns(); |
9f46080c | 82 | ev->what = PROC_EVENT_FORK; |
9e8f90df ON |
83 | rcu_read_lock(); |
84 | parent = rcu_dereference(task->real_parent); | |
85 | ev->event_data.fork.parent_pid = parent->pid; | |
86 | ev->event_data.fork.parent_tgid = parent->tgid; | |
87 | rcu_read_unlock(); | |
9f46080c MH |
88 | ev->event_data.fork.child_pid = task->pid; |
89 | ev->event_data.fork.child_tgid = task->tgid; | |
90 | ||
91 | memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); | |
92 | msg->ack = 0; /* not used */ | |
93 | msg->len = sizeof(*ev); | |
e727ca82 | 94 | msg->flags = 0; /* not used */ |
9f46080c | 95 | /* If cn_netlink_send() failed, the data is not sent */ |
ac8f7330 | 96 | cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL); |
9f46080c MH |
97 | } |
98 | ||
99 | void proc_exec_connector(struct task_struct *task) | |
100 | { | |
101 | struct cn_msg *msg; | |
102 | struct proc_event *ev; | |
1ca1a4cf | 103 | __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8); |
9f46080c MH |
104 | |
105 | if (atomic_read(&proc_event_num_listeners) < 1) | |
106 | return; | |
107 | ||
1ca1a4cf | 108 | msg = buffer_to_cn_msg(buffer); |
f3c48ecc | 109 | ev = (struct proc_event *)msg->data; |
e727ca82 | 110 | memset(&ev->event_data, 0, sizeof(ev->event_data)); |
9f46080c | 111 | get_seq(&msg->seq, &ev->cpu); |
9e93f21b | 112 | ev->timestamp_ns = ktime_get_ns(); |
9f46080c MH |
113 | ev->what = PROC_EVENT_EXEC; |
114 | ev->event_data.exec.process_pid = task->pid; | |
115 | ev->event_data.exec.process_tgid = task->tgid; | |
116 | ||
117 | memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); | |
118 | msg->ack = 0; /* not used */ | |
119 | msg->len = sizeof(*ev); | |
e727ca82 | 120 | msg->flags = 0; /* not used */ |
ac8f7330 | 121 | cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL); |
9f46080c MH |
122 | } |
123 | ||
124 | void proc_id_connector(struct task_struct *task, int which_id) | |
125 | { | |
126 | struct cn_msg *msg; | |
127 | struct proc_event *ev; | |
1ca1a4cf | 128 | __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8); |
c69e8d9c | 129 | const struct cred *cred; |
9f46080c MH |
130 | |
131 | if (atomic_read(&proc_event_num_listeners) < 1) | |
132 | return; | |
133 | ||
1ca1a4cf | 134 | msg = buffer_to_cn_msg(buffer); |
f3c48ecc | 135 | ev = (struct proc_event *)msg->data; |
e727ca82 | 136 | memset(&ev->event_data, 0, sizeof(ev->event_data)); |
9f46080c MH |
137 | ev->what = which_id; |
138 | ev->event_data.id.process_pid = task->pid; | |
139 | ev->event_data.id.process_tgid = task->tgid; | |
c69e8d9c DH |
140 | rcu_read_lock(); |
141 | cred = __task_cred(task); | |
9f46080c | 142 | if (which_id == PROC_EVENT_UID) { |
9582d901 EB |
143 | ev->event_data.id.r.ruid = from_kuid_munged(&init_user_ns, cred->uid); |
144 | ev->event_data.id.e.euid = from_kuid_munged(&init_user_ns, cred->euid); | |
9f46080c | 145 | } else if (which_id == PROC_EVENT_GID) { |
9582d901 EB |
146 | ev->event_data.id.r.rgid = from_kgid_munged(&init_user_ns, cred->gid); |
147 | ev->event_data.id.e.egid = from_kgid_munged(&init_user_ns, cred->egid); | |
c69e8d9c DH |
148 | } else { |
149 | rcu_read_unlock(); | |
f3c48ecc | 150 | return; |
c69e8d9c DH |
151 | } |
152 | rcu_read_unlock(); | |
9f46080c | 153 | get_seq(&msg->seq, &ev->cpu); |
9e93f21b | 154 | ev->timestamp_ns = ktime_get_ns(); |
9f46080c MH |
155 | |
156 | memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); | |
157 | msg->ack = 0; /* not used */ | |
158 | msg->len = sizeof(*ev); | |
e727ca82 | 159 | msg->flags = 0; /* not used */ |
ac8f7330 | 160 | cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL); |
9f46080c MH |
161 | } |
162 | ||
02b51df1 SJR |
163 | void proc_sid_connector(struct task_struct *task) |
164 | { | |
165 | struct cn_msg *msg; | |
166 | struct proc_event *ev; | |
1ca1a4cf | 167 | __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8); |
02b51df1 SJR |
168 | |
169 | if (atomic_read(&proc_event_num_listeners) < 1) | |
170 | return; | |
171 | ||
1ca1a4cf | 172 | msg = buffer_to_cn_msg(buffer); |
02b51df1 | 173 | ev = (struct proc_event *)msg->data; |
e727ca82 | 174 | memset(&ev->event_data, 0, sizeof(ev->event_data)); |
02b51df1 | 175 | get_seq(&msg->seq, &ev->cpu); |
9e93f21b | 176 | ev->timestamp_ns = ktime_get_ns(); |
02b51df1 SJR |
177 | ev->what = PROC_EVENT_SID; |
178 | ev->event_data.sid.process_pid = task->pid; | |
179 | ev->event_data.sid.process_tgid = task->tgid; | |
180 | ||
181 | memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); | |
182 | msg->ack = 0; /* not used */ | |
183 | msg->len = sizeof(*ev); | |
e727ca82 | 184 | msg->flags = 0; /* not used */ |
ac8f7330 | 185 | cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL); |
02b51df1 SJR |
186 | } |
187 | ||
f701e5b7 VZ |
188 | void proc_ptrace_connector(struct task_struct *task, int ptrace_id) |
189 | { | |
190 | struct cn_msg *msg; | |
191 | struct proc_event *ev; | |
1ca1a4cf | 192 | __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8); |
f701e5b7 VZ |
193 | |
194 | if (atomic_read(&proc_event_num_listeners) < 1) | |
195 | return; | |
196 | ||
1ca1a4cf | 197 | msg = buffer_to_cn_msg(buffer); |
f701e5b7 | 198 | ev = (struct proc_event *)msg->data; |
e727ca82 | 199 | memset(&ev->event_data, 0, sizeof(ev->event_data)); |
f701e5b7 | 200 | get_seq(&msg->seq, &ev->cpu); |
9e93f21b | 201 | ev->timestamp_ns = ktime_get_ns(); |
f701e5b7 VZ |
202 | ev->what = PROC_EVENT_PTRACE; |
203 | ev->event_data.ptrace.process_pid = task->pid; | |
204 | ev->event_data.ptrace.process_tgid = task->tgid; | |
205 | if (ptrace_id == PTRACE_ATTACH) { | |
206 | ev->event_data.ptrace.tracer_pid = current->pid; | |
207 | ev->event_data.ptrace.tracer_tgid = current->tgid; | |
208 | } else if (ptrace_id == PTRACE_DETACH) { | |
209 | ev->event_data.ptrace.tracer_pid = 0; | |
210 | ev->event_data.ptrace.tracer_tgid = 0; | |
211 | } else | |
212 | return; | |
213 | ||
214 | memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); | |
215 | msg->ack = 0; /* not used */ | |
216 | msg->len = sizeof(*ev); | |
e727ca82 | 217 | msg->flags = 0; /* not used */ |
ac8f7330 | 218 | cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL); |
f701e5b7 VZ |
219 | } |
220 | ||
f786ecba VZ |
221 | void proc_comm_connector(struct task_struct *task) |
222 | { | |
223 | struct cn_msg *msg; | |
224 | struct proc_event *ev; | |
1ca1a4cf | 225 | __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8); |
f786ecba VZ |
226 | |
227 | if (atomic_read(&proc_event_num_listeners) < 1) | |
228 | return; | |
229 | ||
1ca1a4cf | 230 | msg = buffer_to_cn_msg(buffer); |
f786ecba | 231 | ev = (struct proc_event *)msg->data; |
e727ca82 | 232 | memset(&ev->event_data, 0, sizeof(ev->event_data)); |
f786ecba | 233 | get_seq(&msg->seq, &ev->cpu); |
9e93f21b | 234 | ev->timestamp_ns = ktime_get_ns(); |
f786ecba VZ |
235 | ev->what = PROC_EVENT_COMM; |
236 | ev->event_data.comm.process_pid = task->pid; | |
237 | ev->event_data.comm.process_tgid = task->tgid; | |
238 | get_task_comm(ev->event_data.comm.comm, task); | |
239 | ||
240 | memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); | |
241 | msg->ack = 0; /* not used */ | |
242 | msg->len = sizeof(*ev); | |
e727ca82 | 243 | msg->flags = 0; /* not used */ |
ac8f7330 | 244 | cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL); |
2b5faa4c JD |
245 | } |
246 | ||
247 | void proc_coredump_connector(struct task_struct *task) | |
248 | { | |
249 | struct cn_msg *msg; | |
250 | struct proc_event *ev; | |
1ca1a4cf | 251 | __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8); |
2b5faa4c JD |
252 | |
253 | if (atomic_read(&proc_event_num_listeners) < 1) | |
254 | return; | |
255 | ||
1ca1a4cf | 256 | msg = buffer_to_cn_msg(buffer); |
2b5faa4c | 257 | ev = (struct proc_event *)msg->data; |
e727ca82 | 258 | memset(&ev->event_data, 0, sizeof(ev->event_data)); |
2b5faa4c | 259 | get_seq(&msg->seq, &ev->cpu); |
9e93f21b | 260 | ev->timestamp_ns = ktime_get_ns(); |
2b5faa4c JD |
261 | ev->what = PROC_EVENT_COREDUMP; |
262 | ev->event_data.coredump.process_pid = task->pid; | |
263 | ev->event_data.coredump.process_tgid = task->tgid; | |
264 | ||
265 | memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); | |
266 | msg->ack = 0; /* not used */ | |
267 | msg->len = sizeof(*ev); | |
e727ca82 | 268 | msg->flags = 0; /* not used */ |
ac8f7330 | 269 | cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL); |
f786ecba VZ |
270 | } |
271 | ||
9f46080c MH |
272 | void proc_exit_connector(struct task_struct *task) |
273 | { | |
274 | struct cn_msg *msg; | |
275 | struct proc_event *ev; | |
1ca1a4cf | 276 | __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8); |
9f46080c MH |
277 | |
278 | if (atomic_read(&proc_event_num_listeners) < 1) | |
279 | return; | |
280 | ||
1ca1a4cf | 281 | msg = buffer_to_cn_msg(buffer); |
f3c48ecc | 282 | ev = (struct proc_event *)msg->data; |
e727ca82 | 283 | memset(&ev->event_data, 0, sizeof(ev->event_data)); |
9f46080c | 284 | get_seq(&msg->seq, &ev->cpu); |
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 */ |
ac8f7330 | 296 | cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL); |
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 */ |
ac8f7330 | 328 | cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL); |
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 | } | |
392 | ||
393 | module_init(cn_proc_init); |