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Matt Helsley9f460802005-11-07 00:59:16 -08001/*
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>
Matt Helsleycaf3c9d2006-01-09 20:52:40 -080027#include <linux/ktime.h>
Matt Helsley9f460802005-11-07 00:59:16 -080028#include <linux/init.h>
Matt Helsley1d31a4e2006-06-23 02:05:42 -070029#include <linux/connector.h>
Matt Helsley9f460802005-11-07 00:59:16 -080030#include <asm/atomic.h>
Erik Jacobsonaf3e0952007-01-05 16:37:05 -080031#include <asm/unaligned.h>
Matt Helsley9f460802005-11-07 00:59:16 -080032
33#include <linux/cn_proc.h>
34
35#define CN_PROC_MSG_SIZE (sizeof(struct cn_msg) + sizeof(struct proc_event))
36
37static atomic_t proc_event_num_listeners = ATOMIC_INIT(0);
38static struct cb_id cn_proc_event_id = { CN_IDX_PROC, CN_VAL_PROC };
39
David S. Millercc398c22006-01-08 01:03:34 -080040/* proc_event_counts is used as the sequence number of the netlink message */
Matt Helsley9f460802005-11-07 00:59:16 -080041static DEFINE_PER_CPU(__u32, proc_event_counts) = { 0 };
42
43static inline void get_seq(__u32 *ts, int *cpu)
44{
45 *ts = get_cpu_var(proc_event_counts)++;
46 *cpu = smp_processor_id();
David S. Millercc398c22006-01-08 01:03:34 -080047 put_cpu_var(proc_event_counts);
Matt Helsley9f460802005-11-07 00:59:16 -080048}
49
50void proc_fork_connector(struct task_struct *task)
51{
52 struct cn_msg *msg;
53 struct proc_event *ev;
54 __u8 buffer[CN_PROC_MSG_SIZE];
Chandra Seetharaman822cfbff2006-07-30 03:03:04 -070055 struct timespec ts;
Matt Helsley9f460802005-11-07 00:59:16 -080056
57 if (atomic_read(&proc_event_num_listeners) < 1)
58 return;
59
60 msg = (struct cn_msg*)buffer;
61 ev = (struct proc_event*)msg->data;
62 get_seq(&msg->seq, &ev->cpu);
Chandra Seetharaman822cfbff2006-07-30 03:03:04 -070063 ktime_get_ts(&ts); /* get high res monotonic timestamp */
Erik Jacobsonaf3e0952007-01-05 16:37:05 -080064 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
Matt Helsley9f460802005-11-07 00:59:16 -080065 ev->what = PROC_EVENT_FORK;
66 ev->event_data.fork.parent_pid = task->real_parent->pid;
67 ev->event_data.fork.parent_tgid = task->real_parent->tgid;
68 ev->event_data.fork.child_pid = task->pid;
69 ev->event_data.fork.child_tgid = task->tgid;
70
71 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
72 msg->ack = 0; /* not used */
73 msg->len = sizeof(*ev);
74 /* If cn_netlink_send() failed, the data is not sent */
75 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
76}
77
78void proc_exec_connector(struct task_struct *task)
79{
80 struct cn_msg *msg;
81 struct proc_event *ev;
Chandra Seetharaman822cfbff2006-07-30 03:03:04 -070082 struct timespec ts;
Matt Helsley9f460802005-11-07 00:59:16 -080083 __u8 buffer[CN_PROC_MSG_SIZE];
84
85 if (atomic_read(&proc_event_num_listeners) < 1)
86 return;
87
88 msg = (struct cn_msg*)buffer;
89 ev = (struct proc_event*)msg->data;
90 get_seq(&msg->seq, &ev->cpu);
Chandra Seetharaman822cfbff2006-07-30 03:03:04 -070091 ktime_get_ts(&ts); /* get high res monotonic timestamp */
Erik Jacobsonaf3e0952007-01-05 16:37:05 -080092 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
Matt Helsley9f460802005-11-07 00:59:16 -080093 ev->what = PROC_EVENT_EXEC;
94 ev->event_data.exec.process_pid = task->pid;
95 ev->event_data.exec.process_tgid = task->tgid;
96
97 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
98 msg->ack = 0; /* not used */
99 msg->len = sizeof(*ev);
100 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
101}
102
103void proc_id_connector(struct task_struct *task, int which_id)
104{
105 struct cn_msg *msg;
106 struct proc_event *ev;
107 __u8 buffer[CN_PROC_MSG_SIZE];
Chandra Seetharaman822cfbff2006-07-30 03:03:04 -0700108 struct timespec ts;
David Howellsc69e8d92008-11-14 10:39:19 +1100109 const struct cred *cred;
Matt Helsley9f460802005-11-07 00:59:16 -0800110
111 if (atomic_read(&proc_event_num_listeners) < 1)
112 return;
113
114 msg = (struct cn_msg*)buffer;
115 ev = (struct proc_event*)msg->data;
116 ev->what = which_id;
117 ev->event_data.id.process_pid = task->pid;
118 ev->event_data.id.process_tgid = task->tgid;
David Howellsc69e8d92008-11-14 10:39:19 +1100119 rcu_read_lock();
120 cred = __task_cred(task);
Matt Helsley9f460802005-11-07 00:59:16 -0800121 if (which_id == PROC_EVENT_UID) {
David Howellsc69e8d92008-11-14 10:39:19 +1100122 ev->event_data.id.r.ruid = cred->uid;
123 ev->event_data.id.e.euid = cred->euid;
Matt Helsley9f460802005-11-07 00:59:16 -0800124 } else if (which_id == PROC_EVENT_GID) {
David Howellsc69e8d92008-11-14 10:39:19 +1100125 ev->event_data.id.r.rgid = cred->gid;
126 ev->event_data.id.e.egid = cred->egid;
127 } else {
128 rcu_read_unlock();
Matt Helsley9f460802005-11-07 00:59:16 -0800129 return;
David Howellsc69e8d92008-11-14 10:39:19 +1100130 }
131 rcu_read_unlock();
Matt Helsley9f460802005-11-07 00:59:16 -0800132 get_seq(&msg->seq, &ev->cpu);
Chandra Seetharaman822cfbff2006-07-30 03:03:04 -0700133 ktime_get_ts(&ts); /* get high res monotonic timestamp */
Erik Jacobsonaf3e0952007-01-05 16:37:05 -0800134 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
Matt Helsley9f460802005-11-07 00:59:16 -0800135
136 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
137 msg->ack = 0; /* not used */
138 msg->len = sizeof(*ev);
139 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
140}
141
142void proc_exit_connector(struct task_struct *task)
143{
144 struct cn_msg *msg;
145 struct proc_event *ev;
146 __u8 buffer[CN_PROC_MSG_SIZE];
Chandra Seetharaman822cfbff2006-07-30 03:03:04 -0700147 struct timespec ts;
Matt Helsley9f460802005-11-07 00:59:16 -0800148
149 if (atomic_read(&proc_event_num_listeners) < 1)
150 return;
151
152 msg = (struct cn_msg*)buffer;
153 ev = (struct proc_event*)msg->data;
154 get_seq(&msg->seq, &ev->cpu);
Chandra Seetharaman822cfbff2006-07-30 03:03:04 -0700155 ktime_get_ts(&ts); /* get high res monotonic timestamp */
Erik Jacobsonaf3e0952007-01-05 16:37:05 -0800156 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
Matt Helsley9f460802005-11-07 00:59:16 -0800157 ev->what = PROC_EVENT_EXIT;
158 ev->event_data.exit.process_pid = task->pid;
159 ev->event_data.exit.process_tgid = task->tgid;
160 ev->event_data.exit.exit_code = task->exit_code;
161 ev->event_data.exit.exit_signal = task->exit_signal;
162
163 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
164 msg->ack = 0; /* not used */
165 msg->len = sizeof(*ev);
166 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
167}
168
169/*
170 * Send an acknowledgement message to userspace
171 *
172 * Use 0 for success, EFOO otherwise.
173 * Note: this is the negative of conventional kernel error
174 * values because it's not being returned via syscall return
175 * mechanisms.
176 */
177static void cn_proc_ack(int err, int rcvd_seq, int rcvd_ack)
178{
179 struct cn_msg *msg;
180 struct proc_event *ev;
181 __u8 buffer[CN_PROC_MSG_SIZE];
Chandra Seetharaman822cfbff2006-07-30 03:03:04 -0700182 struct timespec ts;
Matt Helsley9f460802005-11-07 00:59:16 -0800183
184 if (atomic_read(&proc_event_num_listeners) < 1)
185 return;
186
187 msg = (struct cn_msg*)buffer;
188 ev = (struct proc_event*)msg->data;
189 msg->seq = rcvd_seq;
Chandra Seetharaman822cfbff2006-07-30 03:03:04 -0700190 ktime_get_ts(&ts); /* get high res monotonic timestamp */
Erik Jacobsonaf3e0952007-01-05 16:37:05 -0800191 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
Matt Helsley9f460802005-11-07 00:59:16 -0800192 ev->cpu = -1;
193 ev->what = PROC_EVENT_NONE;
194 ev->event_data.ack.err = err;
195 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
196 msg->ack = rcvd_ack + 1;
197 msg->len = sizeof(*ev);
198 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
199}
200
201/**
202 * cn_proc_mcast_ctl
203 * @data: message sent from userspace via the connector
204 */
205static void cn_proc_mcast_ctl(void *data)
206{
207 struct cn_msg *msg = data;
208 enum proc_cn_mcast_op *mc_op = NULL;
209 int err = 0;
210
211 if (msg->len != sizeof(*mc_op))
212 return;
213
214 mc_op = (enum proc_cn_mcast_op*)msg->data;
215 switch (*mc_op) {
216 case PROC_CN_MCAST_LISTEN:
217 atomic_inc(&proc_event_num_listeners);
218 break;
219 case PROC_CN_MCAST_IGNORE:
220 atomic_dec(&proc_event_num_listeners);
221 break;
222 default:
223 err = EINVAL;
224 break;
225 }
226 cn_proc_ack(err, msg->seq, msg->ack);
227}
228
229/*
230 * cn_proc_init - initialization entry point
231 *
232 * Adds the connector callback to the connector driver.
233 */
234static int __init cn_proc_init(void)
235{
236 int err;
237
238 if ((err = cn_add_callback(&cn_proc_event_id, "cn_proc",
239 &cn_proc_mcast_ctl))) {
240 printk(KERN_WARNING "cn_proc failed to register\n");
241 return err;
242 }
243 return 0;
244}
245
246module_init(cn_proc_init);