/* 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> #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) { 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 uid_stat_tcp_snd(uid_t uid, int size) { struct uid_stat *entry; activity_stats_update(); if ((entry = find_uid_stat(uid)) == NULL && ((entry = create_stat(uid)) == NULL)) { 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(); 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);