misc: uidstat: Adding uid stat driver to collect network statistics.
Signed-off-by: Mike Chan <mike@android.com>
diff --git a/drivers/misc/uid_stat.c b/drivers/misc/uid_stat.c
new file mode 100644
index 0000000..e6760b5
--- /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 uid_stat_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 uid_stat_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);