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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>
27#include <linux/ktime.h>
28#include <linux/init.h>
29#include <linux/connector.h>
30#include <linux/gfp.h>
31#include <linux/ptrace.h>
32#include <linux/atomic.h>
33
34#include <asm/unaligned.h>
35
36#include <linux/cn_proc.h>
37
38#define CN_PROC_MSG_SIZE (sizeof(struct cn_msg) + sizeof(struct proc_event))
39
40static atomic_t proc_event_num_listeners = ATOMIC_INIT(0);
41static struct cb_id cn_proc_event_id = { CN_IDX_PROC, CN_VAL_PROC };
42
43/* proc_event_counts is used as the sequence number of the netlink message */
44static DEFINE_PER_CPU(__u32, proc_event_counts) = { 0 };
45
46static inline void get_seq(__u32 *ts, int *cpu)
47{
48 preempt_disable();
49 *ts = __this_cpu_inc_return(proc_event_counts) -1;
50 *cpu = smp_processor_id();
51 preempt_enable();
52}
53
54void proc_fork_connector(struct task_struct *task)
55{
56 struct cn_msg *msg;
57 struct proc_event *ev;
58 __u8 buffer[CN_PROC_MSG_SIZE];
59 struct timespec ts;
60 struct task_struct *parent;
61
62 if (atomic_read(&proc_event_num_listeners) < 1)
63 return;
64
65 msg = (struct cn_msg*)buffer;
66 ev = (struct proc_event*)msg->data;
67 get_seq(&msg->seq, &ev->cpu);
68 ktime_get_ts(&ts); /* get high res monotonic timestamp */
69 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
70 ev->what = PROC_EVENT_FORK;
71 rcu_read_lock();
72 parent = rcu_dereference(task->real_parent);
73 ev->event_data.fork.parent_pid = parent->pid;
74 ev->event_data.fork.parent_tgid = parent->tgid;
75 rcu_read_unlock();
76 ev->event_data.fork.child_pid = task->pid;
77 ev->event_data.fork.child_tgid = task->tgid;
78
79 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
80 msg->ack = 0; /* not used */
81 msg->len = sizeof(*ev);
82 /* If cn_netlink_send() failed, the data is not sent */
83 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
84}
85
86void proc_exec_connector(struct task_struct *task)
87{
88 struct cn_msg *msg;
89 struct proc_event *ev;
90 struct timespec ts;
91 __u8 buffer[CN_PROC_MSG_SIZE];
92
93 if (atomic_read(&proc_event_num_listeners) < 1)
94 return;
95
96 msg = (struct cn_msg*)buffer;
97 ev = (struct proc_event*)msg->data;
98 get_seq(&msg->seq, &ev->cpu);
99 ktime_get_ts(&ts); /* get high res monotonic timestamp */
100 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
101 ev->what = PROC_EVENT_EXEC;
102 ev->event_data.exec.process_pid = task->pid;
103 ev->event_data.exec.process_tgid = task->tgid;
104
105 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
106 msg->ack = 0; /* not used */
107 msg->len = sizeof(*ev);
108 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
109}
110
111void proc_id_connector(struct task_struct *task, int which_id)
112{
113 struct cn_msg *msg;
114 struct proc_event *ev;
115 __u8 buffer[CN_PROC_MSG_SIZE];
116 struct timespec ts;
117 const struct cred *cred;
118
119 if (atomic_read(&proc_event_num_listeners) < 1)
120 return;
121
122 msg = (struct cn_msg*)buffer;
123 ev = (struct proc_event*)msg->data;
124 ev->what = which_id;
125 ev->event_data.id.process_pid = task->pid;
126 ev->event_data.id.process_tgid = task->tgid;
127 rcu_read_lock();
128 cred = __task_cred(task);
129 if (which_id == PROC_EVENT_UID) {
130 ev->event_data.id.r.ruid = cred->uid;
131 ev->event_data.id.e.euid = cred->euid;
132 } else if (which_id == PROC_EVENT_GID) {
133 ev->event_data.id.r.rgid = cred->gid;
134 ev->event_data.id.e.egid = cred->egid;
135 } else {
136 rcu_read_unlock();
137 return;
138 }
139 rcu_read_unlock();
140 get_seq(&msg->seq, &ev->cpu);
141 ktime_get_ts(&ts); /* get high res monotonic timestamp */
142 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
143
144 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
145 msg->ack = 0; /* not used */
146 msg->len = sizeof(*ev);
147 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
148}
149
150void proc_sid_connector(struct task_struct *task)
151{
152 struct cn_msg *msg;
153 struct proc_event *ev;
154 struct timespec ts;
155 __u8 buffer[CN_PROC_MSG_SIZE];
156
157 if (atomic_read(&proc_event_num_listeners) < 1)
158 return;
159
160 msg = (struct cn_msg *)buffer;
161 ev = (struct proc_event *)msg->data;
162 get_seq(&msg->seq, &ev->cpu);
163 ktime_get_ts(&ts); /* get high res monotonic timestamp */
164 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
165 ev->what = PROC_EVENT_SID;
166 ev->event_data.sid.process_pid = task->pid;
167 ev->event_data.sid.process_tgid = task->tgid;
168
169 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
170 msg->ack = 0; /* not used */
171 msg->len = sizeof(*ev);
172 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
173}
174
175void proc_ptrace_connector(struct task_struct *task, int ptrace_id)
176{
177 struct cn_msg *msg;
178 struct proc_event *ev;
179 struct timespec ts;
180 __u8 buffer[CN_PROC_MSG_SIZE];
181
182 if (atomic_read(&proc_event_num_listeners) < 1)
183 return;
184
185 msg = (struct cn_msg *)buffer;
186 ev = (struct proc_event *)msg->data;
187 get_seq(&msg->seq, &ev->cpu);
188 ktime_get_ts(&ts); /* get high res monotonic timestamp */
189 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
190 ev->what = PROC_EVENT_PTRACE;
191 ev->event_data.ptrace.process_pid = task->pid;
192 ev->event_data.ptrace.process_tgid = task->tgid;
193 if (ptrace_id == PTRACE_ATTACH) {
194 ev->event_data.ptrace.tracer_pid = current->pid;
195 ev->event_data.ptrace.tracer_tgid = current->tgid;
196 } else if (ptrace_id == PTRACE_DETACH) {
197 ev->event_data.ptrace.tracer_pid = 0;
198 ev->event_data.ptrace.tracer_tgid = 0;
199 } else
200 return;
201
202 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
203 msg->ack = 0; /* not used */
204 msg->len = sizeof(*ev);
205 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
206}
207
208void proc_exit_connector(struct task_struct *task)
209{
210 struct cn_msg *msg;
211 struct proc_event *ev;
212 __u8 buffer[CN_PROC_MSG_SIZE];
213 struct timespec ts;
214
215 if (atomic_read(&proc_event_num_listeners) < 1)
216 return;
217
218 msg = (struct cn_msg*)buffer;
219 ev = (struct proc_event*)msg->data;
220 get_seq(&msg->seq, &ev->cpu);
221 ktime_get_ts(&ts); /* get high res monotonic timestamp */
222 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
223 ev->what = PROC_EVENT_EXIT;
224 ev->event_data.exit.process_pid = task->pid;
225 ev->event_data.exit.process_tgid = task->tgid;
226 ev->event_data.exit.exit_code = task->exit_code;
227 ev->event_data.exit.exit_signal = task->exit_signal;
228
229 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
230 msg->ack = 0; /* not used */
231 msg->len = sizeof(*ev);
232 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
233}
234
235/*
236 * Send an acknowledgement message to userspace
237 *
238 * Use 0 for success, EFOO otherwise.
239 * Note: this is the negative of conventional kernel error
240 * values because it's not being returned via syscall return
241 * mechanisms.
242 */
243static void cn_proc_ack(int err, int rcvd_seq, int rcvd_ack)
244{
245 struct cn_msg *msg;
246 struct proc_event *ev;
247 __u8 buffer[CN_PROC_MSG_SIZE];
248 struct timespec ts;
249
250 if (atomic_read(&proc_event_num_listeners) < 1)
251 return;
252
253 msg = (struct cn_msg*)buffer;
254 ev = (struct proc_event*)msg->data;
255 msg->seq = rcvd_seq;
256 ktime_get_ts(&ts); /* get high res monotonic timestamp */
257 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
258 ev->cpu = -1;
259 ev->what = PROC_EVENT_NONE;
260 ev->event_data.ack.err = err;
261 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
262 msg->ack = rcvd_ack + 1;
263 msg->len = sizeof(*ev);
264 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
265}
266
267/**
268 * cn_proc_mcast_ctl
269 * @data: message sent from userspace via the connector
270 */
271static void cn_proc_mcast_ctl(struct cn_msg *msg,
272 struct netlink_skb_parms *nsp)
273{
274 enum proc_cn_mcast_op *mc_op = NULL;
275 int err = 0;
276
277 if (msg->len != sizeof(*mc_op))
278 return;
279
280 mc_op = (enum proc_cn_mcast_op*)msg->data;
281 switch (*mc_op) {
282 case PROC_CN_MCAST_LISTEN:
283 atomic_inc(&proc_event_num_listeners);
284 break;
285 case PROC_CN_MCAST_IGNORE:
286 atomic_dec(&proc_event_num_listeners);
287 break;
288 default:
289 err = EINVAL;
290 break;
291 }
292 cn_proc_ack(err, msg->seq, msg->ack);
293}
294
295/*
296 * cn_proc_init - initialization entry point
297 *
298 * Adds the connector callback to the connector driver.
299 */
300static int __init cn_proc_init(void)
301{
302 int err;
303
304 if ((err = cn_add_callback(&cn_proc_event_id, "cn_proc",
305 &cn_proc_mcast_ctl))) {
306 printk(KERN_WARNING "cn_proc failed to register\n");
307 return err;
308 }
309 return 0;
310}
311
312module_init(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/module.h>
26#include <linux/kernel.h>
27#include <linux/ktime.h>
28#include <linux/init.h>
29#include <linux/connector.h>
30#include <linux/gfp.h>
31#include <linux/ptrace.h>
32#include <linux/atomic.h>
33#include <linux/pid_namespace.h>
34
35#include <linux/cn_proc.h>
36
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. */
47static 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}
52
53static atomic_t proc_event_num_listeners = ATOMIC_INIT(0);
54static struct cb_id cn_proc_event_id = { CN_IDX_PROC, CN_VAL_PROC };
55
56/* proc_event_counts is used as the sequence number of the netlink message */
57static DEFINE_PER_CPU(__u32, proc_event_counts) = { 0 };
58
59static inline void get_seq(__u32 *ts, int *cpu)
60{
61 preempt_disable();
62 *ts = __this_cpu_inc_return(proc_event_counts) - 1;
63 *cpu = smp_processor_id();
64 preempt_enable();
65}
66
67void proc_fork_connector(struct task_struct *task)
68{
69 struct cn_msg *msg;
70 struct proc_event *ev;
71 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
72 struct task_struct *parent;
73
74 if (atomic_read(&proc_event_num_listeners) < 1)
75 return;
76
77 msg = buffer_to_cn_msg(buffer);
78 ev = (struct proc_event *)msg->data;
79 memset(&ev->event_data, 0, sizeof(ev->event_data));
80 get_seq(&msg->seq, &ev->cpu);
81 ev->timestamp_ns = ktime_get_ns();
82 ev->what = PROC_EVENT_FORK;
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();
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);
94 msg->flags = 0; /* not used */
95 /* If cn_netlink_send() failed, the data is not sent */
96 cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL);
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 get_seq(&msg->seq, &ev->cpu);
112 ev->timestamp_ns = ktime_get_ns();
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);
120 msg->flags = 0; /* not used */
121 cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL);
122}
123
124void proc_id_connector(struct task_struct *task, int which_id)
125{
126 struct cn_msg *msg;
127 struct proc_event *ev;
128 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
129 const struct cred *cred;
130
131 if (atomic_read(&proc_event_num_listeners) < 1)
132 return;
133
134 msg = buffer_to_cn_msg(buffer);
135 ev = (struct proc_event *)msg->data;
136 memset(&ev->event_data, 0, sizeof(ev->event_data));
137 ev->what = which_id;
138 ev->event_data.id.process_pid = task->pid;
139 ev->event_data.id.process_tgid = task->tgid;
140 rcu_read_lock();
141 cred = __task_cred(task);
142 if (which_id == PROC_EVENT_UID) {
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);
145 } else if (which_id == PROC_EVENT_GID) {
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);
148 } else {
149 rcu_read_unlock();
150 return;
151 }
152 rcu_read_unlock();
153 get_seq(&msg->seq, &ev->cpu);
154 ev->timestamp_ns = ktime_get_ns();
155
156 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
157 msg->ack = 0; /* not used */
158 msg->len = sizeof(*ev);
159 msg->flags = 0; /* not used */
160 cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL);
161}
162
163void proc_sid_connector(struct task_struct *task)
164{
165 struct cn_msg *msg;
166 struct proc_event *ev;
167 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
168
169 if (atomic_read(&proc_event_num_listeners) < 1)
170 return;
171
172 msg = buffer_to_cn_msg(buffer);
173 ev = (struct proc_event *)msg->data;
174 memset(&ev->event_data, 0, sizeof(ev->event_data));
175 get_seq(&msg->seq, &ev->cpu);
176 ev->timestamp_ns = ktime_get_ns();
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);
184 msg->flags = 0; /* not used */
185 cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL);
186}
187
188void proc_ptrace_connector(struct task_struct *task, int ptrace_id)
189{
190 struct cn_msg *msg;
191 struct proc_event *ev;
192 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
193
194 if (atomic_read(&proc_event_num_listeners) < 1)
195 return;
196
197 msg = buffer_to_cn_msg(buffer);
198 ev = (struct proc_event *)msg->data;
199 memset(&ev->event_data, 0, sizeof(ev->event_data));
200 get_seq(&msg->seq, &ev->cpu);
201 ev->timestamp_ns = ktime_get_ns();
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);
217 msg->flags = 0; /* not used */
218 cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL);
219}
220
221void proc_comm_connector(struct task_struct *task)
222{
223 struct cn_msg *msg;
224 struct proc_event *ev;
225 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
226
227 if (atomic_read(&proc_event_num_listeners) < 1)
228 return;
229
230 msg = buffer_to_cn_msg(buffer);
231 ev = (struct proc_event *)msg->data;
232 memset(&ev->event_data, 0, sizeof(ev->event_data));
233 get_seq(&msg->seq, &ev->cpu);
234 ev->timestamp_ns = ktime_get_ns();
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);
243 msg->flags = 0; /* not used */
244 cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL);
245}
246
247void proc_coredump_connector(struct task_struct *task)
248{
249 struct cn_msg *msg;
250 struct proc_event *ev;
251 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
252
253 if (atomic_read(&proc_event_num_listeners) < 1)
254 return;
255
256 msg = buffer_to_cn_msg(buffer);
257 ev = (struct proc_event *)msg->data;
258 memset(&ev->event_data, 0, sizeof(ev->event_data));
259 get_seq(&msg->seq, &ev->cpu);
260 ev->timestamp_ns = ktime_get_ns();
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);
268 msg->flags = 0; /* not used */
269 cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL);
270}
271
272void proc_exit_connector(struct task_struct *task)
273{
274 struct cn_msg *msg;
275 struct proc_event *ev;
276 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
277
278 if (atomic_read(&proc_event_num_listeners) < 1)
279 return;
280
281 msg = buffer_to_cn_msg(buffer);
282 ev = (struct proc_event *)msg->data;
283 memset(&ev->event_data, 0, sizeof(ev->event_data));
284 get_seq(&msg->seq, &ev->cpu);
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 cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL);
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 cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL);
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}
392
393module_init(cn_proc_init);