1 /* drivers/misc/uid_stat.c
3 * Copyright (C) 2008 - 2009 Google, Inc.
5 * This software is licensed under the terms of the GNU General Public
6 * License version 2, as published by the Free Software Foundation, and
7 * may be copied, distributed, and modified under those terms.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
16 #include <asm/atomic.h>
18 #include <linux/err.h>
19 #include <linux/init.h>
20 #include <linux/kernel.h>
21 #include <linux/list.h>
22 #include <linux/proc_fs.h>
23 #include <linux/seq_file.h>
24 #include <linux/slab.h>
25 #include <linux/spinlock.h>
26 #include <linux/stat.h>
27 #include <linux/uid_stat.h>
28 #include <net/activity_stats.h>
30 static DEFINE_SPINLOCK(uid_lock);
31 static LIST_HEAD(uid_list);
32 static struct proc_dir_entry *parent;
35 struct list_head link;
41 static struct uid_stat *find_uid_stat(uid_t uid) {
42 struct uid_stat *entry;
44 list_for_each_entry(entry, &uid_list, link) {
45 if (entry->uid == uid) {
52 static int uid_stat_atomic_int_show(struct seq_file *m, void *v)
55 atomic_t *counter = m->private;
57 bytes = (unsigned int) (atomic_read(counter) + INT_MIN);
58 seq_printf(m, "%u\n", bytes);
59 return seq_has_overflowed(m) ? -ENOSPC : 0;
62 static int uid_stat_read_atomic_int_open(struct inode *inode, struct file *file)
64 return single_open(file, uid_stat_atomic_int_show, PDE_DATA(inode));
67 static const struct file_operations uid_stat_read_atomic_int_fops = {
68 .open = uid_stat_read_atomic_int_open,
71 .release = seq_release,
74 /* Create a new entry for tracking the specified uid. */
75 static struct uid_stat *create_stat(uid_t uid) {
76 struct uid_stat *new_uid;
77 /* Create the uid stat struct and append it to the list. */
78 new_uid = kmalloc(sizeof(struct uid_stat), GFP_ATOMIC);
83 /* Counters start at INT_MIN, so we can track 4GB of network traffic. */
84 atomic_set(&new_uid->tcp_rcv, INT_MIN);
85 atomic_set(&new_uid->tcp_snd, INT_MIN);
87 list_add_tail(&new_uid->link, &uid_list);
91 static void create_stat_proc(struct uid_stat *new_uid)
94 struct proc_dir_entry *entry;
95 sprintf(uid_s, "%d", new_uid->uid);
96 entry = proc_mkdir(uid_s, parent);
98 /* Keep reference to uid_stat so we know what uid to read stats from. */
99 proc_create_data("tcp_snd", S_IRUGO, entry,
100 &uid_stat_read_atomic_int_fops, &new_uid->tcp_snd);
102 proc_create_data("tcp_rcv", S_IRUGO, entry,
103 &uid_stat_read_atomic_int_fops, &new_uid->tcp_rcv);
106 static struct uid_stat *find_or_create_uid_stat(uid_t uid)
108 struct uid_stat *entry;
110 spin_lock_irqsave(&uid_lock, flags);
111 entry = find_uid_stat(uid);
113 spin_unlock_irqrestore(&uid_lock, flags);
116 entry = create_stat(uid);
117 spin_unlock_irqrestore(&uid_lock, flags);
119 create_stat_proc(entry);
123 int uid_stat_tcp_snd(uid_t uid, int size) {
124 struct uid_stat *entry;
125 activity_stats_update();
126 entry = find_or_create_uid_stat(uid);
129 atomic_add(size, &entry->tcp_snd);
133 int uid_stat_tcp_rcv(uid_t uid, int size) {
134 struct uid_stat *entry;
135 activity_stats_update();
136 entry = find_or_create_uid_stat(uid);
139 atomic_add(size, &entry->tcp_rcv);
143 static int __init uid_stat_init(void)
145 parent = proc_mkdir("uid_stat", NULL);
147 pr_err("uid_stat: failed to create proc entry\n");
153 __initcall(uid_stat_init);