[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / core / netprio_cgroup.c

/*
 * net/core/netprio_cgroup.c	Priority Control Group
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 *
 * Authors:	Neil Horman <nhorman@tuxdriver.com>
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/skbuff.h>
#include <linux/cgroup.h>
#include <linux/rcupdate.h>
#include <linux/atomic.h>
#include <net/rtnetlink.h>
#include <net/pkt_cls.h>
#include <net/sock.h>
#include <net/netprio_cgroup.h>

static struct cgroup_subsys_state *cgrp_create(struct cgroup_subsys *ss,
					       struct cgroup *cgrp);
static void cgrp_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp);
static int cgrp_populate(struct cgroup_subsys *ss, struct cgroup *cgrp);

struct cgroup_subsys net_prio_subsys = {
	.name		= "net_prio",
	.create		= cgrp_create,
	.destroy	= cgrp_destroy,
	.populate	= cgrp_populate,
#ifdef CONFIG_NETPRIO_CGROUP
	.subsys_id	= net_prio_subsys_id,
#endif
	.module		= THIS_MODULE
};

#define PRIOIDX_SZ 128

static unsigned long prioidx_map[PRIOIDX_SZ];
static DEFINE_SPINLOCK(prioidx_map_lock);
static atomic_t max_prioidx = ATOMIC_INIT(0);

static inline struct cgroup_netprio_state *cgrp_netprio_state(struct cgroup *cgrp)
{
	return container_of(cgroup_subsys_state(cgrp, net_prio_subsys_id),
			    struct cgroup_netprio_state, css);
}

static int get_prioidx(u32 *prio)
{
	unsigned long flags;
	u32 prioidx;

	spin_lock_irqsave(&prioidx_map_lock, flags);
	prioidx = find_first_zero_bit(prioidx_map, sizeof(unsigned long) * PRIOIDX_SZ);
	set_bit(prioidx, prioidx_map);
	spin_unlock_irqrestore(&prioidx_map_lock, flags);
	if (prioidx == sizeof(unsigned long) * PRIOIDX_SZ)
		return -ENOSPC;

	atomic_set(&max_prioidx, prioidx);
	*prio = prioidx;
	return 0;
}

static void put_prioidx(u32 idx)
{
	unsigned long flags;

	spin_lock_irqsave(&prioidx_map_lock, flags);
	clear_bit(idx, prioidx_map);
	spin_unlock_irqrestore(&prioidx_map_lock, flags);
}

static void extend_netdev_table(struct net_device *dev, u32 new_len)
{
	size_t new_size = sizeof(struct netprio_map) +
			   ((sizeof(u32) * new_len));
	struct netprio_map *new_priomap = kzalloc(new_size, GFP_KERNEL);
	struct netprio_map *old_priomap;
	int i;

	old_priomap  = rtnl_dereference(dev->priomap);

	if (!new_priomap) {
		printk(KERN_WARNING "Unable to alloc new priomap!\n");
		return;
	}

	for (i = 0;
	     old_priomap && (i < old_priomap->priomap_len);
	     i++)
		new_priomap->priomap[i] = old_priomap->priomap[i];

	new_priomap->priomap_len = new_len;

	rcu_assign_pointer(dev->priomap, new_priomap);
	if (old_priomap)
		kfree_rcu(old_priomap, rcu);
}

static void update_netdev_tables(void)
{
	struct net_device *dev;
	u32 max_len = atomic_read(&max_prioidx);
	struct netprio_map *map;

	rtnl_lock();
	for_each_netdev(&init_net, dev) {
		map = rtnl_dereference(dev->priomap);
		if ((!map) ||
		    (map->priomap_len < max_len))
			extend_netdev_table(dev, max_len);
	}
	rtnl_unlock();
}

static struct cgroup_subsys_state *cgrp_create(struct cgroup_subsys *ss,
						 struct cgroup *cgrp)
{
	struct cgroup_netprio_state *cs;
	int ret;

	cs = kzalloc(sizeof(*cs), GFP_KERNEL);
	if (!cs)
		return ERR_PTR(-ENOMEM);

	if (cgrp->parent && cgrp_netprio_state(cgrp->parent)->prioidx) {
		kfree(cs);
		return ERR_PTR(-EINVAL);
	}

	ret = get_prioidx(&cs->prioidx);
	if (ret != 0) {
		printk(KERN_WARNING "No space in priority index array\n");
		kfree(cs);
		return ERR_PTR(ret);
	}

	return &cs->css;
}

static void cgrp_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp)
{
	struct cgroup_netprio_state *cs;
	struct net_device *dev;
	struct netprio_map *map;

	cs = cgrp_netprio_state(cgrp);
	rtnl_lock();
	for_each_netdev(&init_net, dev) {
		map = rtnl_dereference(dev->priomap);
		if (map)
			map->priomap[cs->prioidx] = 0;
	}
	rtnl_unlock();
	put_prioidx(cs->prioidx);
	kfree(cs);
}

static u64 read_prioidx(struct cgroup *cgrp, struct cftype *cft)
{
	return (u64)cgrp_netprio_state(cgrp)->prioidx;
}

static int read_priomap(struct cgroup *cont, struct cftype *cft,
			struct cgroup_map_cb *cb)
{
	struct net_device *dev;
	u32 prioidx = cgrp_netprio_state(cont)->prioidx;
	u32 priority;
	struct netprio_map *map;

	rcu_read_lock();
	for_each_netdev_rcu(&init_net, dev) {
		map = rcu_dereference(dev->priomap);
		priority = map ? map->priomap[prioidx] : 0;
		cb->fill(cb, dev->name, priority);
	}
	rcu_read_unlock();
	return 0;
}

static int write_priomap(struct cgroup *cgrp, struct cftype *cft,
			 const char *buffer)
{
	char *devname = kstrdup(buffer, GFP_KERNEL);
	int ret = -EINVAL;
	u32 prioidx = cgrp_netprio_state(cgrp)->prioidx;
	unsigned long priority;
	char *priostr;
	struct net_device *dev;
	struct netprio_map *map;

	if (!devname)
		return -ENOMEM;

	/*
	 * Minimally sized valid priomap string
	 */
	if (strlen(devname) < 3)
		goto out_free_devname;

	priostr = strstr(devname, " ");
	if (!priostr)
		goto out_free_devname;

	/*
	 *Separate the devname from the associated priority
	 *and advance the priostr poitner to the priority value
	 */
	*priostr = '\0';
	priostr++;

	/*
	 * If the priostr points to NULL, we're at the end of the passed
	 * in string, and its not a valid write
	 */
	if (*priostr == '\0')
		goto out_free_devname;

	ret = kstrtoul(priostr, 10, &priority);
	if (ret < 0)
		goto out_free_devname;

	ret = -ENODEV;

	dev = dev_get_by_name(&init_net, devname);
	if (!dev)
		goto out_free_devname;

	update_netdev_tables();
	ret = 0;
	rcu_read_lock();
	map = rcu_dereference(dev->priomap);
	if (map)
		map->priomap[prioidx] = priority;
	rcu_read_unlock();
	dev_put(dev);

out_free_devname:
	kfree(devname);
	return ret;
}

static struct cftype ss_files[] = {
	{
		.name = "prioidx",
		.read_u64 = read_prioidx,
	},
	{
		.name = "ifpriomap",
		.read_map = read_priomap,
		.write_string = write_priomap,
	},
};

static int cgrp_populate(struct cgroup_subsys *ss, struct cgroup *cgrp)
{
	return cgroup_add_files(cgrp, ss, ss_files, ARRAY_SIZE(ss_files));
}

static int netprio_device_event(struct notifier_block *unused,
				unsigned long event, void *ptr)
{
	struct net_device *dev = ptr;
	struct netprio_map *old;
	u32 max_len = atomic_read(&max_prioidx);

	/*
	 * Note this is called with rtnl_lock held so we have update side
	 * protection on our rcu assignments
	 */

	switch (event) {

	case NETDEV_REGISTER:
		if (max_len)
			extend_netdev_table(dev, max_len);
		break;
	case NETDEV_UNREGISTER:
		old = rtnl_dereference(dev->priomap);
		rcu_assign_pointer(dev->priomap, NULL);
		if (old)
			kfree_rcu(old, rcu);
		break;
	}
	return NOTIFY_DONE;
}

static struct notifier_block netprio_device_notifier = {
	.notifier_call = netprio_device_event
};

static int __init init_cgroup_netprio(void)
{
	int ret;

	ret = cgroup_load_subsys(&net_prio_subsys);
	if (ret)
		goto out;
#ifndef CONFIG_NETPRIO_CGROUP
	smp_wmb();
	net_prio_subsys_id = net_prio_subsys.subsys_id;
#endif

	register_netdevice_notifier(&netprio_device_notifier);

out:
	return ret;
}

static void __exit exit_cgroup_netprio(void)
{
	struct netprio_map *old;
	struct net_device *dev;

	unregister_netdevice_notifier(&netprio_device_notifier);

	cgroup_unload_subsys(&net_prio_subsys);

#ifndef CONFIG_NETPRIO_CGROUP
	net_prio_subsys_id = -1;
	synchronize_rcu();
#endif

	rtnl_lock();
	for_each_netdev(&init_net, dev) {
		old = rtnl_dereference(dev->priomap);
		rcu_assign_pointer(dev->priomap, NULL);
		if (old)
			kfree_rcu(old, rcu);
	}
	rtnl_unlock();
}

module_init(init_cgroup_netprio);
module_exit(exit_cgroup_netprio);
MODULE_LICENSE("GPL v2");
Commit	Line	Data
5bc1421e NH	1	/*
	2	* net/core/netprio_cgroup.c Priority Control Group
	3	*
	4	* This program is free software; you can redistribute it and/or
	5	* modify it under the terms of the GNU General Public License
	6	* as published by the Free Software Foundation; either version
	7	* 2 of the License, or (at your option) any later version.
	8	*
	9	* Authors: Neil Horman <nhorman@tuxdriver.com>
	10	*/
	11
	12	#include <linux/module.h>
	13	#include <linux/slab.h>
	14	#include <linux/types.h>
	15	#include <linux/string.h>
	16	#include <linux/errno.h>
	17	#include <linux/skbuff.h>
	18	#include <linux/cgroup.h>
	19	#include <linux/rcupdate.h>
	20	#include <linux/atomic.h>
	21	#include <net/rtnetlink.h>
	22	#include <net/pkt_cls.h>
	23	#include <net/sock.h>
	24	#include <net/netprio_cgroup.h>
	25
	26	static struct cgroup_subsys_state cgrp_create(struct cgroup_subsys ss,
	27	struct cgroup *cgrp);
	28	static void cgrp_destroy(struct cgroup_subsys ss, struct cgroup cgrp);
	29	static int cgrp_populate(struct cgroup_subsys ss, struct cgroup cgrp);
	30
	31	struct cgroup_subsys net_prio_subsys = {
	32	.name = "net_prio",
	33	.create = cgrp_create,
	34	.destroy = cgrp_destroy,
	35	.populate = cgrp_populate,
	36	#ifdef CONFIG_NETPRIO_CGROUP
	37	.subsys_id = net_prio_subsys_id,
	38	#endif
	39	.module = THIS_MODULE
	40	};
	41
	42	#define PRIOIDX_SZ 128
	43
	44	static unsigned long prioidx_map[PRIOIDX_SZ];
	45	static DEFINE_SPINLOCK(prioidx_map_lock);
	46	static atomic_t max_prioidx = ATOMIC_INIT(0);
	47
	48	static inline struct cgroup_netprio_state cgrp_netprio_state(struct cgroup cgrp)
	49	{
	50	return container_of(cgroup_subsys_state(cgrp, net_prio_subsys_id),
	51	struct cgroup_netprio_state, css);
	52	}
	53
	54	static int get_prioidx(u32 *prio)
	55	{
	56	unsigned long flags;
	57	u32 prioidx;
	58
	59	spin_lock_irqsave(&prioidx_map_lock, flags);
	60	prioidx = find_first_zero_bit(prioidx_map, sizeof(unsigned long) * PRIOIDX_SZ);
	61	set_bit(prioidx, prioidx_map);
	62	spin_unlock_irqrestore(&prioidx_map_lock, flags);
	63	if (prioidx == sizeof(unsigned long) * PRIOIDX_SZ)
	64	return -ENOSPC;
65
66	atomic_set(&max_prioidx, prioidx);
67	*prio = prioidx;
68	return 0;
69	}
70
71	static void put_prioidx(u32 idx)
72	{
73	unsigned long flags;
74
75	spin_lock_irqsave(&prioidx_map_lock, flags);
76	clear_bit(idx, prioidx_map);
77	spin_unlock_irqrestore(&prioidx_map_lock, flags);
78	}
79
80	static void extend_netdev_table(struct net_device *dev, u32 new_len)
81	{
82	size_t new_size = sizeof(struct netprio_map) +
83	((sizeof(u32) * new_len));
84	struct netprio_map *new_priomap = kzalloc(new_size, GFP_KERNEL);
85	struct netprio_map *old_priomap;
86	int i;
87
88	old_priomap = rtnl_dereference(dev->priomap);
89
90	if (!new_priomap) {
91	printk(KERN_WARNING "Unable to alloc new priomap!\n");
92	return;
93	}
94
95	for (i = 0;
96	old_priomap && (i < old_priomap->priomap_len);
97	i++)
98	new_priomap->priomap[i] = old_priomap->priomap[i];
99
100	new_priomap->priomap_len = new_len;
101
102	rcu_assign_pointer(dev->priomap, new_priomap);
103	if (old_priomap)
104	kfree_rcu(old_priomap, rcu);
105	}
106
107	static void update_netdev_tables(void)
108	{
109	struct net_device *dev;
110	u32 max_len = atomic_read(&max_prioidx);
111	struct netprio_map *map;
112
113	rtnl_lock();
114	for_each_netdev(&init_net, dev) {
115	map = rtnl_dereference(dev->priomap);
116	if ((!map) \|\|
117	(map->priomap_len < max_len))
118	extend_netdev_table(dev, max_len);
119	}
120	rtnl_unlock();
121	}
122
123	static struct cgroup_subsys_state cgrp_create(struct cgroup_subsys ss,
124	struct cgroup *cgrp)
125	{
126	struct cgroup_netprio_state *cs;
127	int ret;
128
129	cs = kzalloc(sizeof(*cs), GFP_KERNEL);
130	if (!cs)
131	return ERR_PTR(-ENOMEM);
132
133	if (cgrp->parent && cgrp_netprio_state(cgrp->parent)->prioidx) {
134	kfree(cs);
135	return ERR_PTR(-EINVAL);
136	}
137
138	ret = get_prioidx(&cs->prioidx);
139	if (ret != 0) {
140	printk(KERN_WARNING "No space in priority index array\n");
141	kfree(cs);
142	return ERR_PTR(ret);
143	}
144
145	return &cs->css;
146	}
147
148	static void cgrp_destroy(struct cgroup_subsys ss, struct cgroup cgrp)
149	{
150	struct cgroup_netprio_state *cs;
151	struct net_device *dev;
152	struct netprio_map *map;
153
154	cs = cgrp_netprio_state(cgrp);
155	rtnl_lock();
156	for_each_netdev(&init_net, dev) {
157	map = rtnl_dereference(dev->priomap);
158	if (map)
159	map->priomap[cs->prioidx] = 0;
160	}
161	rtnl_unlock();
162	put_prioidx(cs->prioidx);
163	kfree(cs);
164	}
165
166	static u64 read_prioidx(struct cgroup cgrp, struct cftype cft)
167	{
168	return (u64)cgrp_netprio_state(cgrp)->prioidx;
169	}
170
171	static int read_priomap(struct cgroup cont, struct cftype cft,
172	struct cgroup_map_cb *cb)
173	{
174	struct net_device *dev;
175	u32 prioidx = cgrp_netprio_state(cont)->prioidx;
176	u32 priority;
177	struct netprio_map *map;
178
179	rcu_read_lock();
180	for_each_netdev_rcu(&init_net, dev) {
181	map = rcu_dereference(dev->priomap);
182	priority = map ? map->priomap[prioidx] : 0;
183	cb->fill(cb, dev->name, priority);
184	}
185	rcu_read_unlock();
186	return 0;
187	}
188
189	static int write_priomap(struct cgroup cgrp, struct cftype cft,
190	const char *buffer)
191	{
192	char *devname = kstrdup(buffer, GFP_KERNEL);
193	int ret = -EINVAL;
194	u32 prioidx = cgrp_netprio_state(cgrp)->prioidx;
195	unsigned long priority;
196	char *priostr;
197	struct net_device *dev;
198	struct netprio_map *map;
199
200	if (!devname)
201	return -ENOMEM;
202
203	/*
204	* Minimally sized valid priomap string
205	*/
206	if (strlen(devname) < 3)
207	goto out_free_devname;
208
209	priostr = strstr(devname, " ");
210	if (!priostr)
211	goto out_free_devname;
212
213	/*
214	*Separate the devname from the associated priority
215	*and advance the priostr poitner to the priority value
216	*/
217	*priostr = '\0';
218	priostr++;
219
220	/*
221	* If the priostr points to NULL, we're at the end of the passed
222	* in string, and its not a valid write
223	*/
224	if (*priostr == '\0')
225	goto out_free_devname;
226
227	ret = kstrtoul(priostr, 10, &priority);
228	if (ret < 0)
229	goto out_free_devname;
230
231	ret = -ENODEV;
232
233	dev = dev_get_by_name(&init_net, devname);
234	if (!dev)
235	goto out_free_devname;
236
237	update_netdev_tables();
238	ret = 0;
239	rcu_read_lock();
240	map = rcu_dereference(dev->priomap);
241	if (map)
242	map->priomap[prioidx] = priority;
243	rcu_read_unlock();
244	dev_put(dev);
245
246	out_free_devname:
247	kfree(devname);
248	return ret;
249	}
250
251	static struct cftype ss_files[] = {
252	{
253	.name = "prioidx",
254	.read_u64 = read_prioidx,
255	},
256	{
257	.name = "ifpriomap",
258	.read_map = read_priomap,
259	.write_string = write_priomap,
260	},
261	};
262
263	static int cgrp_populate(struct cgroup_subsys ss, struct cgroup cgrp)
264	{
265	return cgroup_add_files(cgrp, ss, ss_files, ARRAY_SIZE(ss_files));
266	}
267
268	static int netprio_device_event(struct notifier_block *unused,
269	unsigned long event, void *ptr)
270	{
271	struct net_device *dev = ptr;
272	struct netprio_map *old;
273	u32 max_len = atomic_read(&max_prioidx);
274
275	/*
276	* Note this is called with rtnl_lock held so we have update side
277	* protection on our rcu assignments
278	*/
279
280	switch (event) {
281
282	case NETDEV_REGISTER:
283	if (max_len)
284	extend_netdev_table(dev, max_len);
285	break;
286	case NETDEV_UNREGISTER:
287	old = rtnl_dereference(dev->priomap);
288	rcu_assign_pointer(dev->priomap, NULL);
289	if (old)
290	kfree_rcu(old, rcu);
291	break;
292	}
293	return NOTIFY_DONE;
294	}
295
296	static struct notifier_block netprio_device_notifier = {
297	.notifier_call = netprio_device_event
298	};
299
300	static int __init init_cgroup_netprio(void)
301	{
302	int ret;
303
304	ret = cgroup_load_subsys(&net_prio_subsys);
305	if (ret)
306	goto out;
307	#ifndef CONFIG_NETPRIO_CGROUP
308	smp_wmb();
309	net_prio_subsys_id = net_prio_subsys.subsys_id;
310	#endif
311
312	register_netdevice_notifier(&netprio_device_notifier);
313
314	out:
315	return ret;
316	}
317
318	static void __exit exit_cgroup_netprio(void)
319	{
320	struct netprio_map *old;
321	struct net_device *dev;
322
323	unregister_netdevice_notifier(&netprio_device_notifier);
324
325	cgroup_unload_subsys(&net_prio_subsys);
326
327	#ifndef CONFIG_NETPRIO_CGROUP
328	net_prio_subsys_id = -1;
329	synchronize_rcu();
330	#endif
331
332	rtnl_lock();
333	for_each_netdev(&init_net, dev) {
334	old = rtnl_dereference(dev->priomap);
335	rcu_assign_pointer(dev->priomap, NULL);
336	if (old)
337	kfree_rcu(old, rcu);
338	}
339	rtnl_unlock();
340	}
341
342	module_init(init_cgroup_netprio);
343	module_exit(exit_cgroup_netprio);
344	MODULE_LICENSE("GPL v2");