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