diff options
Diffstat (limited to 'drivers/misc/uid_stat.c')
| -rw-r--r-- | drivers/misc/uid_stat.c | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/drivers/misc/uid_stat.c b/drivers/misc/uid_stat.c new file mode 100644 index 000000000000..43a548bab7ac --- /dev/null +++ b/drivers/misc/uid_stat.c @@ -0,0 +1,153 @@ +/* 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/slab.h> +#include <linux/spinlock.h> +#include <linux/stat.h> +#include <linux/uid_stat.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) { + unsigned long flags; + struct uid_stat *entry; + + spin_lock_irqsave(&uid_lock, flags); + list_for_each_entry(entry, &uid_list, link) { + if (entry->uid == uid) { + spin_unlock_irqrestore(&uid_lock, flags); + return entry; + } + } + spin_unlock_irqrestore(&uid_lock, flags); + return NULL; +} + +static int tcp_snd_read_proc(char *page, char **start, off_t off, + int count, int *eof, void *data) +{ + int len; + unsigned int bytes; + char *p = page; + struct uid_stat *uid_entry = (struct uid_stat *) data; + if (!data) + return 0; + + bytes = (unsigned int) (atomic_read(&uid_entry->tcp_snd) + INT_MIN); + p += sprintf(p, "%u\n", bytes); + len = (p - page) - off; + *eof = (len <= count) ? 1 : 0; + *start = page + off; + return len; +} + +static int tcp_rcv_read_proc(char *page, char **start, off_t off, + int count, int *eof, void *data) +{ + int len; + unsigned int bytes; + char *p = page; + struct uid_stat *uid_entry = (struct uid_stat *) data; + if (!data) + return 0; + + bytes = (unsigned int) (atomic_read(&uid_entry->tcp_rcv) + INT_MIN); + p += sprintf(p, "%u\n", bytes); + len = (p - page) - off; + *eof = (len <= count) ? 1 : 0; + *start = page + off; + return len; +} + +/* Create a new entry for tracking the specified uid. */ +static struct uid_stat *create_stat(uid_t uid) { + unsigned long flags; + char uid_s[32]; + struct uid_stat *new_uid; + struct proc_dir_entry *entry; + + /* Create the uid stat struct and append it to the list. */ + if ((new_uid = kmalloc(sizeof(struct uid_stat), GFP_KERNEL)) == NULL) + 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); + + spin_lock_irqsave(&uid_lock, flags); + list_add_tail(&new_uid->link, &uid_list); + spin_unlock_irqrestore(&uid_lock, flags); + + sprintf(uid_s, "%d", uid); + entry = proc_mkdir(uid_s, parent); + + /* Keep reference to uid_stat so we know what uid to read stats from. */ + create_proc_read_entry("tcp_snd", S_IRUGO, entry , tcp_snd_read_proc, + (void *) new_uid); + + create_proc_read_entry("tcp_rcv", S_IRUGO, entry, tcp_rcv_read_proc, + (void *) new_uid); + + return new_uid; +} + +int update_tcp_snd(uid_t uid, int size) { + struct uid_stat *entry; + if ((entry = find_uid_stat(uid)) == NULL && + ((entry = create_stat(uid)) == NULL)) { + return -1; + } + atomic_add(size, &entry->tcp_snd); + return 0; +} + +int update_tcp_rcv(uid_t uid, int size) { + struct uid_stat *entry; + if ((entry = find_uid_stat(uid)) == NULL && + ((entry = create_stat(uid)) == NULL)) { + 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); |