[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);
	if (prioidx == sizeof(unsigned long) * PRIOIDX_SZ) {
		spin_unlock_irqrestore(&prioidx_map_lock, flags);
		return -ENOSPC;
	}
	set_bit(prioidx, prioidx_map);
	spin_unlock_irqrestore(&prioidx_map_lock, flags);
	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_INIT_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_INIT_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
0221cd51	31	struct cgroup_subsys net_prio_subsys = {
5bc1421e NH	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);
5962b35c NH	61	if (prioidx == sizeof(unsigned long) * PRIOIDX_SZ) {
	62	spin_unlock_irqrestore(&prioidx_map_lock, flags);
	63	return -ENOSPC;
	64	}
5bc1421e NH	65	set_bit(prioidx, prioidx_map);
5bc1421e NH	66	spin_unlock_irqrestore(&prioidx_map_lock, flags);
5bc1421e NH	67	atomic_set(&max_prioidx, prioidx);
	68	*prio = prioidx;
	69	return 0;
	70	}
	71
	72	static void put_prioidx(u32 idx)
	73	{
	74	unsigned long flags;
	75
	76	spin_lock_irqsave(&prioidx_map_lock, flags);
	77	clear_bit(idx, prioidx_map);
	78	spin_unlock_irqrestore(&prioidx_map_lock, flags);
	79	}
	80
	81	static void extend_netdev_table(struct net_device *dev, u32 new_len)
	82	{
	83	size_t new_size = sizeof(struct netprio_map) +
	84	((sizeof(u32) * new_len));
	85	struct netprio_map *new_priomap = kzalloc(new_size, GFP_KERNEL);
	86	struct netprio_map *old_priomap;
	87	int i;
	88
	89	old_priomap = rtnl_dereference(dev->priomap);
	90
	91	if (!new_priomap) {
	92	printk(KERN_WARNING "Unable to alloc new priomap!\n");
	93	return;
	94	}
	95
	96	for (i = 0;
	97	old_priomap && (i < old_priomap->priomap_len);
	98	i++)
	99	new_priomap->priomap[i] = old_priomap->priomap[i];
	100
	101	new_priomap->priomap_len = new_len;
	102
	103	rcu_assign_pointer(dev->priomap, new_priomap);
	104	if (old_priomap)
	105	kfree_rcu(old_priomap, rcu);
	106	}
	107
	108	static void update_netdev_tables(void)
	109	{
	110	struct net_device *dev;
	111	u32 max_len = atomic_read(&max_prioidx);
	112	struct netprio_map *map;
	113
	114	rtnl_lock();
	115	for_each_netdev(&init_net, dev) {
	116	map = rtnl_dereference(dev->priomap);
	117	if ((!map) \|\|
	118	(map->priomap_len < max_len))
	119	extend_netdev_table(dev, max_len);
	120	}
	121	rtnl_unlock();
	122	}
	123
	124	static struct cgroup_subsys_state cgrp_create(struct cgroup_subsys ss,
	125	struct cgroup *cgrp)
	126	{
	127	struct cgroup_netprio_state *cs;
	128	int ret;
	129
	130	cs = kzalloc(sizeof(*cs), GFP_KERNEL);
131	if (!cs)
132	return ERR_PTR(-ENOMEM);
133
134	if (cgrp->parent && cgrp_netprio_state(cgrp->parent)->prioidx) {
135	kfree(cs);
136	return ERR_PTR(-EINVAL);
137	}
138
139	ret = get_prioidx(&cs->prioidx);
140	if (ret != 0) {
141	printk(KERN_WARNING "No space in priority index array\n");
142	kfree(cs);
143	return ERR_PTR(ret);
144	}
145
146	return &cs->css;
147	}
148
149	static void cgrp_destroy(struct cgroup_subsys ss, struct cgroup cgrp)
150	{
151	struct cgroup_netprio_state *cs;
152	struct net_device *dev;
153	struct netprio_map *map;
154
155	cs = cgrp_netprio_state(cgrp);
156	rtnl_lock();
157	for_each_netdev(&init_net, dev) {
158	map = rtnl_dereference(dev->priomap);
159	if (map)
160	map->priomap[cs->prioidx] = 0;
161	}
162	rtnl_unlock();
163	put_prioidx(cs->prioidx);
164	kfree(cs);
165	}
166
167	static u64 read_prioidx(struct cgroup cgrp, struct cftype cft)
168	{
169	return (u64)cgrp_netprio_state(cgrp)->prioidx;
170	}
171
172	static int read_priomap(struct cgroup cont, struct cftype cft,
173	struct cgroup_map_cb *cb)
174	{
175	struct net_device *dev;
176	u32 prioidx = cgrp_netprio_state(cont)->prioidx;
177	u32 priority;
178	struct netprio_map *map;
179
180	rcu_read_lock();
181	for_each_netdev_rcu(&init_net, dev) {
182	map = rcu_dereference(dev->priomap);
183	priority = map ? map->priomap[prioidx] : 0;
184	cb->fill(cb, dev->name, priority);
185	}
186	rcu_read_unlock();
187	return 0;
188	}
189
190	static int write_priomap(struct cgroup cgrp, struct cftype cft,
191	const char *buffer)
192	{
193	char *devname = kstrdup(buffer, GFP_KERNEL);
194	int ret = -EINVAL;
195	u32 prioidx = cgrp_netprio_state(cgrp)->prioidx;
196	unsigned long priority;
197	char *priostr;
198	struct net_device *dev;
199	struct netprio_map *map;
200
201	if (!devname)
202	return -ENOMEM;
203
204	/*
205	* Minimally sized valid priomap string
206	*/
207	if (strlen(devname) < 3)
208	goto out_free_devname;
209
210	priostr = strstr(devname, " ");
211	if (!priostr)
212	goto out_free_devname;
213
214	/*
215	*Separate the devname from the associated priority
216	*and advance the priostr poitner to the priority value
217	*/
218	*priostr = '\0';
219	priostr++;
220
221	/*
222	* If the priostr points to NULL, we're at the end of the passed
223	* in string, and its not a valid write
224	*/
225	if (*priostr == '\0')
226	goto out_free_devname;
227
228	ret = kstrtoul(priostr, 10, &priority);
229	if (ret < 0)
230	goto out_free_devname;
231
232	ret = -ENODEV;
233
234	dev = dev_get_by_name(&init_net, devname);
235	if (!dev)
236	goto out_free_devname;
237
238	update_netdev_tables();
239	ret = 0;
240	rcu_read_lock();
241	map = rcu_dereference(dev->priomap);
242	if (map)
243	map->priomap[prioidx] = priority;
244	rcu_read_unlock();
245	dev_put(dev);
246
247	out_free_devname:
248	kfree(devname);
249	return ret;
250	}
251
252	static struct cftype ss_files[] = {
253	{
254	.name = "prioidx",
255	.read_u64 = read_prioidx,
256	},
257	{
258	.name = "ifpriomap",
259	.read_map = read_priomap,
260	.write_string = write_priomap,
261	},
262	};
263
264	static int cgrp_populate(struct cgroup_subsys ss, struct cgroup cgrp)
265	{
266	return cgroup_add_files(cgrp, ss, ss_files, ARRAY_SIZE(ss_files));
267	}
268
269	static int netprio_device_event(struct notifier_block *unused,
270	unsigned long event, void *ptr)
271	{
272	struct net_device *dev = ptr;
273	struct netprio_map *old;
274	u32 max_len = atomic_read(&max_prioidx);
275
276	/*
277	* Note this is called with rtnl_lock held so we have update side
278	* protection on our rcu assignments
279	*/
280
281	switch (event) {
282
283	case NETDEV_REGISTER:
284	if (max_len)
285	extend_netdev_table(dev, max_len);
286	break;
287	case NETDEV_UNREGISTER:
288	old = rtnl_dereference(dev->priomap);
2cfa5a04	289	RCU_INIT_POINTER(dev->priomap, NULL);
5bc1421e NH	290	if (old)
	291	kfree_rcu(old, rcu);
	292	break;
	293	}
	294	return NOTIFY_DONE;
	295	}
	296
	297	static struct notifier_block netprio_device_notifier = {
	298	.notifier_call = netprio_device_event
	299	};
	300
	301	static int __init init_cgroup_netprio(void)
	302	{
	303	int ret;
	304
	305	ret = cgroup_load_subsys(&net_prio_subsys);
	306	if (ret)
	307	goto out;
	308	#ifndef CONFIG_NETPRIO_CGROUP
	309	smp_wmb();
	310	net_prio_subsys_id = net_prio_subsys.subsys_id;
	311	#endif
	312
	313	register_netdevice_notifier(&netprio_device_notifier);
	314
	315	out:
	316	return ret;
	317	}
	318
	319	static void __exit exit_cgroup_netprio(void)
	320	{
	321	struct netprio_map *old;
	322	struct net_device *dev;
	323
	324	unregister_netdevice_notifier(&netprio_device_notifier);
	325
	326	cgroup_unload_subsys(&net_prio_subsys);
	327
	328	#ifndef CONFIG_NETPRIO_CGROUP
	329	net_prio_subsys_id = -1;
	330	synchronize_rcu();
	331	#endif
	332
	333	rtnl_lock();
	334	for_each_netdev(&init_net, dev) {
	335	old = rtnl_dereference(dev->priomap);
2cfa5a04	336	RCU_INIT_POINTER(dev->priomap, NULL);
5bc1421e NH	337	if (old)
	338	kfree_rcu(old, rcu);
	339	}
	340	rtnl_unlock();
	341	}
	342
	343	module_init(init_cgroup_netprio);
	344	module_exit(exit_cgroup_netprio);
	345	MODULE_LICENSE("GPL v2");