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/slab.h>
24 #include <linux/spinlock.h>
25 #include <linux/stat.h>
26 #include <linux/uid_stat.h>
27 #include <net/activity_stats.h>
29 static DEFINE_SPINLOCK(uid_lock);
30 static LIST_HEAD(uid_list);
31 static struct proc_dir_entry *parent;
34 struct list_head link;
40 static struct uid_stat *find_uid_stat(uid_t uid) {
42 struct uid_stat *entry;
44 spin_lock_irqsave(&uid_lock, flags);
45 list_for_each_entry(entry, &uid_list, link) {
46 if (entry->uid == uid) {
47 spin_unlock_irqrestore(&uid_lock, flags);
51 spin_unlock_irqrestore(&uid_lock, flags);
55 static int tcp_snd_read_proc(char *page, char **start, off_t off,
56 int count, int *eof, void *data)
61 struct uid_stat *uid_entry = (struct uid_stat *) data;
65 bytes = (unsigned int) (atomic_read(&uid_entry->tcp_snd) + INT_MIN);
66 p += sprintf(p, "%u\n", bytes);
67 len = (p - page) - off;
68 *eof = (len <= count) ? 1 : 0;
73 static int tcp_rcv_read_proc(char *page, char **start, off_t off,
74 int count, int *eof, void *data)
79 struct uid_stat *uid_entry = (struct uid_stat *) data;
83 bytes = (unsigned int) (atomic_read(&uid_entry->tcp_rcv) + INT_MIN);
84 p += sprintf(p, "%u\n", bytes);
85 len = (p - page) - off;
86 *eof = (len <= count) ? 1 : 0;
91 /* Create a new entry for tracking the specified uid. */
92 static struct uid_stat *create_stat(uid_t uid) {
95 struct uid_stat *new_uid;
96 struct proc_dir_entry *entry;
98 /* Create the uid stat struct and append it to the list. */
99 if ((new_uid = kmalloc(sizeof(struct uid_stat), GFP_KERNEL)) == NULL)
103 /* Counters start at INT_MIN, so we can track 4GB of network traffic. */
104 atomic_set(&new_uid->tcp_rcv, INT_MIN);
105 atomic_set(&new_uid->tcp_snd, INT_MIN);
107 spin_lock_irqsave(&uid_lock, flags);
108 list_add_tail(&new_uid->link, &uid_list);
109 spin_unlock_irqrestore(&uid_lock, flags);
111 sprintf(uid_s, "%d", uid);
112 entry = proc_mkdir(uid_s, parent);
114 /* Keep reference to uid_stat so we know what uid to read stats from. */
115 create_proc_read_entry("tcp_snd", S_IRUGO, entry , tcp_snd_read_proc,
118 create_proc_read_entry("tcp_rcv", S_IRUGO, entry, tcp_rcv_read_proc,
124 int uid_stat_tcp_snd(uid_t uid, int size) {
125 struct uid_stat *entry;
126 activity_stats_update();
127 if ((entry = find_uid_stat(uid)) == NULL &&
128 ((entry = create_stat(uid)) == NULL)) {
131 atomic_add(size, &entry->tcp_snd);
135 int uid_stat_tcp_rcv(uid_t uid, int size) {
136 struct uid_stat *entry;
137 activity_stats_update();
138 if ((entry = find_uid_stat(uid)) == NULL &&
139 ((entry = create_stat(uid)) == NULL)) {
142 atomic_add(size, &entry->tcp_rcv);
146 static int __init uid_stat_init(void)
148 parent = proc_mkdir("uid_stat", NULL);
150 pr_err("uid_stat: failed to create proc entry\n");
156 __initcall(uid_stat_init);