2 * cn_proc.c - process events connector
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.
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.
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.
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
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>
34 #include <linux/cn_proc.h>
35 #include <linux/locallock.h>
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.
44 #define CN_PROC_MSG_SIZE (sizeof(struct cn_msg) + sizeof(struct proc_event) + 4)
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)
49 BUILD_BUG_ON(sizeof(struct cn_msg) != 20);
50 return (struct cn_msg *)(buffer + 4);
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 };
56 /* proc_event_counts is used as the sequence number of the netlink message */
57 static DEFINE_PER_CPU(__u32, proc_event_counts) = { 0 };
58 static DEFINE_LOCAL_IRQ_LOCK(send_msg_lock);
60 static inline void send_msg(struct cn_msg *msg)
62 local_lock(send_msg_lock);
64 msg->seq = __this_cpu_inc_return(proc_event_counts) - 1;
65 ((struct proc_event *)msg->data)->cpu = smp_processor_id();
68 * Preemption remains disabled during send to ensure the messages are
69 * ordered according to their sequence numbers.
71 * If cn_netlink_send() fails, the data is not sent.
73 cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_NOWAIT);
75 local_unlock(send_msg_lock);
78 void proc_fork_connector(struct task_struct *task)
81 struct proc_event *ev;
82 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
83 struct task_struct *parent;
85 if (atomic_read(&proc_event_num_listeners) < 1)
88 msg = buffer_to_cn_msg(buffer);
89 ev = (struct proc_event *)msg->data;
90 memset(&ev->event_data, 0, sizeof(ev->event_data));
91 ev->timestamp_ns = ktime_get_ns();
92 ev->what = PROC_EVENT_FORK;
94 parent = rcu_dereference(task->real_parent);
95 ev->event_data.fork.parent_pid = parent->pid;
96 ev->event_data.fork.parent_tgid = parent->tgid;
98 ev->event_data.fork.child_pid = task->pid;
99 ev->event_data.fork.child_tgid = task->tgid;
101 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
102 msg->ack = 0; /* not used */
103 msg->len = sizeof(*ev);
104 msg->flags = 0; /* not used */
108 void proc_exec_connector(struct task_struct *task)
111 struct proc_event *ev;
112 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
114 if (atomic_read(&proc_event_num_listeners) < 1)
117 msg = buffer_to_cn_msg(buffer);
118 ev = (struct proc_event *)msg->data;
119 memset(&ev->event_data, 0, sizeof(ev->event_data));
120 ev->timestamp_ns = ktime_get_ns();
121 ev->what = PROC_EVENT_EXEC;
122 ev->event_data.exec.process_pid = task->pid;
123 ev->event_data.exec.process_tgid = task->tgid;
125 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
126 msg->ack = 0; /* not used */
127 msg->len = sizeof(*ev);
128 msg->flags = 0; /* not used */
132 void proc_id_connector(struct task_struct *task, int which_id)
135 struct proc_event *ev;
136 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
137 const struct cred *cred;
139 if (atomic_read(&proc_event_num_listeners) < 1)
142 msg = buffer_to_cn_msg(buffer);
143 ev = (struct proc_event *)msg->data;
144 memset(&ev->event_data, 0, sizeof(ev->event_data));
146 ev->event_data.id.process_pid = task->pid;
147 ev->event_data.id.process_tgid = task->tgid;
149 cred = __task_cred(task);
150 if (which_id == PROC_EVENT_UID) {
151 ev->event_data.id.r.ruid = from_kuid_munged(&init_user_ns, cred->uid);
152 ev->event_data.id.e.euid = from_kuid_munged(&init_user_ns, cred->euid);
153 } else if (which_id == PROC_EVENT_GID) {
154 ev->event_data.id.r.rgid = from_kgid_munged(&init_user_ns, cred->gid);
155 ev->event_data.id.e.egid = from_kgid_munged(&init_user_ns, cred->egid);
161 ev->timestamp_ns = ktime_get_ns();
163 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
164 msg->ack = 0; /* not used */
165 msg->len = sizeof(*ev);
166 msg->flags = 0; /* not used */
170 void proc_sid_connector(struct task_struct *task)
173 struct proc_event *ev;
174 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
176 if (atomic_read(&proc_event_num_listeners) < 1)
179 msg = buffer_to_cn_msg(buffer);
180 ev = (struct proc_event *)msg->data;
181 memset(&ev->event_data, 0, sizeof(ev->event_data));
182 ev->timestamp_ns = ktime_get_ns();
183 ev->what = PROC_EVENT_SID;
184 ev->event_data.sid.process_pid = task->pid;
185 ev->event_data.sid.process_tgid = task->tgid;
187 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
188 msg->ack = 0; /* not used */
189 msg->len = sizeof(*ev);
190 msg->flags = 0; /* not used */
194 void proc_ptrace_connector(struct task_struct *task, int ptrace_id)
197 struct proc_event *ev;
198 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
200 if (atomic_read(&proc_event_num_listeners) < 1)
203 msg = buffer_to_cn_msg(buffer);
204 ev = (struct proc_event *)msg->data;
205 memset(&ev->event_data, 0, sizeof(ev->event_data));
206 ev->timestamp_ns = ktime_get_ns();
207 ev->what = PROC_EVENT_PTRACE;
208 ev->event_data.ptrace.process_pid = task->pid;
209 ev->event_data.ptrace.process_tgid = task->tgid;
210 if (ptrace_id == PTRACE_ATTACH) {
211 ev->event_data.ptrace.tracer_pid = current->pid;
212 ev->event_data.ptrace.tracer_tgid = current->tgid;
213 } else if (ptrace_id == PTRACE_DETACH) {
214 ev->event_data.ptrace.tracer_pid = 0;
215 ev->event_data.ptrace.tracer_tgid = 0;
219 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
220 msg->ack = 0; /* not used */
221 msg->len = sizeof(*ev);
222 msg->flags = 0; /* not used */
226 void proc_comm_connector(struct task_struct *task)
229 struct proc_event *ev;
230 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
232 if (atomic_read(&proc_event_num_listeners) < 1)
235 msg = buffer_to_cn_msg(buffer);
236 ev = (struct proc_event *)msg->data;
237 memset(&ev->event_data, 0, sizeof(ev->event_data));
238 ev->timestamp_ns = ktime_get_ns();
239 ev->what = PROC_EVENT_COMM;
240 ev->event_data.comm.process_pid = task->pid;
241 ev->event_data.comm.process_tgid = task->tgid;
242 get_task_comm(ev->event_data.comm.comm, task);
244 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
245 msg->ack = 0; /* not used */
246 msg->len = sizeof(*ev);
247 msg->flags = 0; /* not used */
251 void proc_coredump_connector(struct task_struct *task)
254 struct proc_event *ev;
255 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
257 if (atomic_read(&proc_event_num_listeners) < 1)
260 msg = buffer_to_cn_msg(buffer);
261 ev = (struct proc_event *)msg->data;
262 memset(&ev->event_data, 0, sizeof(ev->event_data));
263 ev->timestamp_ns = ktime_get_ns();
264 ev->what = PROC_EVENT_COREDUMP;
265 ev->event_data.coredump.process_pid = task->pid;
266 ev->event_data.coredump.process_tgid = task->tgid;
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 */
275 void proc_exit_connector(struct task_struct *task)
278 struct proc_event *ev;
279 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
281 if (atomic_read(&proc_event_num_listeners) < 1)
284 msg = buffer_to_cn_msg(buffer);
285 ev = (struct proc_event *)msg->data;
286 memset(&ev->event_data, 0, sizeof(ev->event_data));
287 ev->timestamp_ns = ktime_get_ns();
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;
294 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
295 msg->ack = 0; /* not used */
296 msg->len = sizeof(*ev);
297 msg->flags = 0; /* not used */
302 * Send an acknowledgement message to userspace
304 * Use 0 for success, EFOO otherwise.
305 * Note: this is the negative of conventional kernel error
306 * values because it's not being returned via syscall return
309 static void cn_proc_ack(int err, int rcvd_seq, int rcvd_ack)
312 struct proc_event *ev;
313 __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
315 if (atomic_read(&proc_event_num_listeners) < 1)
318 msg = buffer_to_cn_msg(buffer);
319 ev = (struct proc_event *)msg->data;
320 memset(&ev->event_data, 0, sizeof(ev->event_data));
322 ev->timestamp_ns = ktime_get_ns();
324 ev->what = PROC_EVENT_NONE;
325 ev->event_data.ack.err = err;
326 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
327 msg->ack = rcvd_ack + 1;
328 msg->len = sizeof(*ev);
329 msg->flags = 0; /* not used */
335 * @data: message sent from userspace via the connector
337 static void cn_proc_mcast_ctl(struct cn_msg *msg,
338 struct netlink_skb_parms *nsp)
340 enum proc_cn_mcast_op *mc_op = NULL;
343 if (msg->len != sizeof(*mc_op))
347 * Events are reported with respect to the initial pid
348 * and user namespaces so ignore requestors from
351 if ((current_user_ns() != &init_user_ns) ||
352 (task_active_pid_ns(current) != &init_pid_ns))
355 /* Can only change if privileged. */
356 if (!__netlink_ns_capable(nsp, &init_user_ns, CAP_NET_ADMIN)) {
361 mc_op = (enum proc_cn_mcast_op *)msg->data;
363 case PROC_CN_MCAST_LISTEN:
364 atomic_inc(&proc_event_num_listeners);
366 case PROC_CN_MCAST_IGNORE:
367 atomic_dec(&proc_event_num_listeners);
375 cn_proc_ack(err, msg->seq, msg->ack);
379 * cn_proc_init - initialization entry point
381 * Adds the connector callback to the connector driver.
383 static int __init cn_proc_init(void)
385 int err = cn_add_callback(&cn_proc_event_id,
389 pr_warn("cn_proc failed to register\n");
394 device_initcall(cn_proc_init);