uidstat: Adding uid stat driver to collect network statistics.

Signed-off-by: Mike Chan <mike@android.com>

3 files changed, 158 insertions, 0 deletions

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index d011d25ccc76..61d065f1033b 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -227,6 +227,10 @@ config DELL_LAPTOP
 	This driver adds support for rfkill and backlight control to Dell
 	laptops.
 
+config UID_STAT
+	bool "UID based statistics tracking exported to /proc/uid_stat"
+	default n
+
 source "drivers/misc/c2port/Kconfig"
 source "drivers/misc/eeprom/Kconfig"
 
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 1d94b0d47dc9..6ce68d795799 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -19,5 +19,6 @@ obj-$(CONFIG_KGDB_TESTS)	+= kgdbts.o
 obj-$(CONFIG_SGI_XP)		+= sgi-xp/
 obj-$(CONFIG_SGI_GRU)		+= sgi-gru/
 obj-$(CONFIG_HP_ILO)		+= hpilo.o
+obj-$(CONFIG_UID_STAT)		+= uid_stat.o
 obj-$(CONFIG_C2PORT)		+= c2port/
 obj-y				+= eeprom/
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);