diff options
Diffstat (limited to 'drivers/misc/uid_stat.c')
| -rw-r--r-- | drivers/misc/uid_stat.c | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/drivers/misc/uid_stat.c b/drivers/misc/uid_stat.c new file mode 100644 index 00000000000..4766c1f83b9 --- /dev/null +++ b/drivers/misc/uid_stat.c @@ -0,0 +1,152 @@ +/* drivers/misc/uid_stat.c + * + * Copyright (C) 2008 - 2009 Google, Inc. + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ + +#include <asm/atomic.h> + +#include <linux/err.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/proc_fs.h> +#include <linux/seq_file.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/stat.h> +#include <linux/uid_stat.h> +#include <net/activity_stats.h> + +static DEFINE_SPINLOCK(uid_lock); +static LIST_HEAD(uid_list); +static struct proc_dir_entry *parent; + +struct uid_stat { + struct list_head link; + uid_t uid; + atomic_t tcp_rcv; + atomic_t tcp_snd; +}; + +static struct uid_stat *find_uid_stat(uid_t uid) { + struct uid_stat *entry; + + list_for_each_entry(entry, &uid_list, link) { + if (entry->uid == uid) { + return entry; + } + } + return NULL; +} + +static int uid_stat_atomic_int_show(struct seq_file *m, void *v) +{ + unsigned int bytes; + atomic_t *counter = m->private; + + bytes = (unsigned int) (atomic_read(counter) + INT_MIN); + return seq_printf(m, "%u\n", bytes); +} + +static int uid_stat_read_atomic_int_open(struct inode *inode, struct file *file) +{ + return single_open(file, uid_stat_atomic_int_show, PDE_DATA(inode)); +} + +static const struct file_operations uid_stat_read_atomic_int_fops = { + .open = uid_stat_read_atomic_int_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + +/* Create a new entry for tracking the specified uid. */ +static struct uid_stat *create_stat(uid_t uid) { + struct uid_stat *new_uid; + /* Create the uid stat struct and append it to the list. */ + new_uid = kmalloc(sizeof(struct uid_stat), GFP_ATOMIC); + if (!new_uid) + return NULL; + + new_uid->uid = uid; + /* Counters start at INT_MIN, so we can track 4GB of network traffic. */ + atomic_set(&new_uid->tcp_rcv, INT_MIN); + atomic_set(&new_uid->tcp_snd, INT_MIN); + + list_add_tail(&new_uid->link, &uid_list); + return new_uid; +} + +static void create_stat_proc(struct uid_stat *new_uid) +{ + char uid_s[32]; + struct proc_dir_entry *entry; + sprintf(uid_s, "%d", new_uid->uid); + entry = proc_mkdir(uid_s, parent); + + /* Keep reference to uid_stat so we know what uid to read stats from. */ + proc_create_data("tcp_snd", S_IRUGO, entry, + &uid_stat_read_atomic_int_fops, &new_uid->tcp_snd); + + proc_create_data("tcp_rcv", S_IRUGO, entry, + &uid_stat_read_atomic_int_fops, &new_uid->tcp_rcv); +} + +static struct uid_stat *find_or_create_uid_stat(uid_t uid) +{ + struct uid_stat *entry; + unsigned long flags; + spin_lock_irqsave(&uid_lock, flags); + entry = find_uid_stat(uid); + if (entry) { + spin_unlock_irqrestore(&uid_lock, flags); + return entry; + } + entry = create_stat(uid); + spin_unlock_irqrestore(&uid_lock, flags); + if (entry) + create_stat_proc(entry); + return entry; +} + +int uid_stat_tcp_snd(uid_t uid, int size) { + struct uid_stat *entry; + activity_stats_update(); + entry = find_or_create_uid_stat(uid); + if (!entry) + return -1; + atomic_add(size, &entry->tcp_snd); + return 0; +} + +int uid_stat_tcp_rcv(uid_t uid, int size) { + struct uid_stat *entry; + activity_stats_update(); + entry = find_or_create_uid_stat(uid); + if (!entry) + return -1; + atomic_add(size, &entry->tcp_rcv); + return 0; +} + +static int __init uid_stat_init(void) +{ + parent = proc_mkdir("uid_stat", NULL); + if (!parent) { + pr_err("uid_stat: failed to create proc entry\n"); + return -1; + } + return 0; +} + +__initcall(uid_stat_init); |