[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>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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>

#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) {
		pr_warn("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) + 1;
	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 *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) {
		pr_warn("No space in priority index array\n");
		kfree(cs);
		return ERR_PTR(ret);
	}

	return &cs->css;
}

static void cgrp_destroy(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,
	},
	{ }	/* terminate */
};

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

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

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

	switch (event) {
	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
e005d193 JP	12	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
e005d193 JP	13
5bc1421e NH	14	#include <linux/module.h>
	15	#include <linux/slab.h>
	16	#include <linux/types.h>
	17	#include <linux/string.h>
	18	#include <linux/errno.h>
	19	#include <linux/skbuff.h>
	20	#include <linux/cgroup.h>
	21	#include <linux/rcupdate.h>
	22	#include <linux/atomic.h>
	23	#include <net/rtnetlink.h>
	24	#include <net/pkt_cls.h>
	25	#include <net/sock.h>
	26	#include <net/netprio_cgroup.h>
	27
5bc1421e NH	28	#define PRIOIDX_SZ 128
	29
	30	static unsigned long prioidx_map[PRIOIDX_SZ];
	31	static DEFINE_SPINLOCK(prioidx_map_lock);
	32	static atomic_t max_prioidx = ATOMIC_INIT(0);
	33
	34	static inline struct cgroup_netprio_state cgrp_netprio_state(struct cgroup cgrp)
	35	{
	36	return container_of(cgroup_subsys_state(cgrp, net_prio_subsys_id),
	37	struct cgroup_netprio_state, css);
	38	}
	39
	40	static int get_prioidx(u32 *prio)
	41	{
	42	unsigned long flags;
	43	u32 prioidx;
	44
	45	spin_lock_irqsave(&prioidx_map_lock, flags);
	46	prioidx = find_first_zero_bit(prioidx_map, sizeof(unsigned long) * PRIOIDX_SZ);
5962b35c NH	47	if (prioidx == sizeof(unsigned long) * PRIOIDX_SZ) {
	48	spin_unlock_irqrestore(&prioidx_map_lock, flags);
	49	return -ENOSPC;
	50	}
5bc1421e NH	51	set_bit(prioidx, prioidx_map);
5bc1421e NH	52	spin_unlock_irqrestore(&prioidx_map_lock, flags);
5bc1421e NH	53	atomic_set(&max_prioidx, prioidx);
	54	*prio = prioidx;
	55	return 0;
	56	}
	57
	58	static void put_prioidx(u32 idx)
	59	{
	60	unsigned long flags;
	61
	62	spin_lock_irqsave(&prioidx_map_lock, flags);
	63	clear_bit(idx, prioidx_map);
	64	spin_unlock_irqrestore(&prioidx_map_lock, flags);
	65	}
	66
	67	static void extend_netdev_table(struct net_device *dev, u32 new_len)
	68	{
	69	size_t new_size = sizeof(struct netprio_map) +
	70	((sizeof(u32) * new_len));
	71	struct netprio_map *new_priomap = kzalloc(new_size, GFP_KERNEL);
	72	struct netprio_map *old_priomap;
	73	int i;
	74
	75	old_priomap = rtnl_dereference(dev->priomap);
	76
	77	if (!new_priomap) {
e005d193	78	pr_warn("Unable to alloc new priomap!\n");
5bc1421e NH	79	return;
	80	}
	81
	82	for (i = 0;
	83	old_priomap && (i < old_priomap->priomap_len);
	84	i++)
	85	new_priomap->priomap[i] = old_priomap->priomap[i];
	86
	87	new_priomap->priomap_len = new_len;
	88
	89	rcu_assign_pointer(dev->priomap, new_priomap);
	90	if (old_priomap)
	91	kfree_rcu(old_priomap, rcu);
	92	}
	93
	94	static void update_netdev_tables(void)
	95	{
	96	struct net_device *dev;
a87dfe14	97	u32 max_len = atomic_read(&max_prioidx) + 1;
5bc1421e NH	98	struct netprio_map *map;
	99
	100	rtnl_lock();
	101	for_each_netdev(&init_net, dev) {
	102	map = rtnl_dereference(dev->priomap);
	103	if ((!map) \|\|
	104	(map->priomap_len < max_len))
	105	extend_netdev_table(dev, max_len);
	106	}
	107	rtnl_unlock();
	108	}
	109
761b3ef5	110	static struct cgroup_subsys_state cgrp_create(struct cgroup cgrp)
5bc1421e NH	111	{
	112	struct cgroup_netprio_state *cs;
	113	int ret;
	114
	115	cs = kzalloc(sizeof(*cs), GFP_KERNEL);
	116	if (!cs)
	117	return ERR_PTR(-ENOMEM);
	118
	119	if (cgrp->parent && cgrp_netprio_state(cgrp->parent)->prioidx) {
	120	kfree(cs);
	121	return ERR_PTR(-EINVAL);
	122	}
	123
	124	ret = get_prioidx(&cs->prioidx);
	125	if (ret != 0) {
e005d193	126	pr_warn("No space in priority index array\n");
5bc1421e NH	127	kfree(cs);
	128	return ERR_PTR(ret);
	129	}
	130
	131	return &cs->css;
	132	}
	133
761b3ef5	134	static void cgrp_destroy(struct cgroup *cgrp)
5bc1421e NH	135	{
	136	struct cgroup_netprio_state *cs;
	137	struct net_device *dev;
	138	struct netprio_map *map;
	139
	140	cs = cgrp_netprio_state(cgrp);
	141	rtnl_lock();
	142	for_each_netdev(&init_net, dev) {
	143	map = rtnl_dereference(dev->priomap);
	144	if (map)
	145	map->priomap[cs->prioidx] = 0;
	146	}
	147	rtnl_unlock();
	148	put_prioidx(cs->prioidx);
	149	kfree(cs);
	150	}
	151
	152	static u64 read_prioidx(struct cgroup cgrp, struct cftype cft)
	153	{
	154	return (u64)cgrp_netprio_state(cgrp)->prioidx;
	155	}
	156
	157	static int read_priomap(struct cgroup cont, struct cftype cft,
	158	struct cgroup_map_cb *cb)
	159	{
	160	struct net_device *dev;
	161	u32 prioidx = cgrp_netprio_state(cont)->prioidx;
	162	u32 priority;
	163	struct netprio_map *map;
	164
	165	rcu_read_lock();
	166	for_each_netdev_rcu(&init_net, dev) {
	167	map = rcu_dereference(dev->priomap);
	168	priority = map ? map->priomap[prioidx] : 0;
	169	cb->fill(cb, dev->name, priority);
	170	}
	171	rcu_read_unlock();
	172	return 0;
	173	}
	174
	175	static int write_priomap(struct cgroup cgrp, struct cftype cft,
	176	const char *buffer)
	177	{
	178	char *devname = kstrdup(buffer, GFP_KERNEL);
	179	int ret = -EINVAL;
	180	u32 prioidx = cgrp_netprio_state(cgrp)->prioidx;
	181	unsigned long priority;
	182	char *priostr;
	183	struct net_device *dev;
	184	struct netprio_map *map;
	185
	186	if (!devname)
	187	return -ENOMEM;
	188
	189	/*
	190	* Minimally sized valid priomap string
	191	*/
	192	if (strlen(devname) < 3)
	193	goto out_free_devname;
	194
	195	priostr = strstr(devname, " ");
	196	if (!priostr)
	197	goto out_free_devname;
	198
199	/*
200	*Separate the devname from the associated priority
201	*and advance the priostr poitner to the priority value
202	*/
203	*priostr = '\0';
204	priostr++;
205
206	/*
207	* If the priostr points to NULL, we're at the end of the passed
208	* in string, and its not a valid write
209	*/
210	if (*priostr == '\0')
211	goto out_free_devname;
212
213	ret = kstrtoul(priostr, 10, &priority);
214	if (ret < 0)
215	goto out_free_devname;
216
217	ret = -ENODEV;
218
219	dev = dev_get_by_name(&init_net, devname);
220	if (!dev)
221	goto out_free_devname;
222
223	update_netdev_tables();
224	ret = 0;
225	rcu_read_lock();
226	map = rcu_dereference(dev->priomap);
227	if (map)
228	map->priomap[prioidx] = priority;
229	rcu_read_unlock();
230	dev_put(dev);
231
232	out_free_devname:
233	kfree(devname);
234	return ret;
235	}
236
237	static struct cftype ss_files[] = {
238	{
239	.name = "prioidx",
240	.read_u64 = read_prioidx,
241	},
242	{
243	.name = "ifpriomap",
244	.read_map = read_priomap,
245	.write_string = write_priomap,
246	},
4baf6e33	247	{ } /* terminate */
5bc1421e NH	248	};
5bc1421e NH	249
676f7c8f TH	250	struct cgroup_subsys net_prio_subsys = {
	251	.name = "net_prio",
	252	.create = cgrp_create,
	253	.destroy = cgrp_destroy,
676f7c8f TH	254	#ifdef CONFIG_NETPRIO_CGROUP
	255	.subsys_id = net_prio_subsys_id,
	256	#endif
4baf6e33	257	.base_cftypes = ss_files,
676f7c8f TH	258	.module = THIS_MODULE
676f7c8f TH	259	};
5bc1421e NH	260
	261	static int netprio_device_event(struct notifier_block *unused,
	262	unsigned long event, void *ptr)
	263	{
	264	struct net_device *dev = ptr;
	265	struct netprio_map *old;
5bc1421e NH	266
	267	/*
	268	* Note this is called with rtnl_lock held so we have update side
	269	* protection on our rcu assignments
	270	*/
	271
	272	switch (event) {
5bc1421e NH	273	case NETDEV_UNREGISTER:
5bc1421e NH	274	old = rtnl_dereference(dev->priomap);
2cfa5a04	275	RCU_INIT_POINTER(dev->priomap, NULL);
5bc1421e NH	276	if (old)
	277	kfree_rcu(old, rcu);
	278	break;
	279	}
	280	return NOTIFY_DONE;
	281	}
	282
	283	static struct notifier_block netprio_device_notifier = {
	284	.notifier_call = netprio_device_event
	285	};
	286
	287	static int __init init_cgroup_netprio(void)
	288	{
	289	int ret;
	290
	291	ret = cgroup_load_subsys(&net_prio_subsys);
	292	if (ret)
	293	goto out;
	294	#ifndef CONFIG_NETPRIO_CGROUP
	295	smp_wmb();
	296	net_prio_subsys_id = net_prio_subsys.subsys_id;
	297	#endif
	298
	299	register_netdevice_notifier(&netprio_device_notifier);
	300
	301	out:
	302	return ret;
	303	}
	304
	305	static void __exit exit_cgroup_netprio(void)
	306	{
	307	struct netprio_map *old;
	308	struct net_device *dev;
	309
	310	unregister_netdevice_notifier(&netprio_device_notifier);
	311
	312	cgroup_unload_subsys(&net_prio_subsys);
	313
	314	#ifndef CONFIG_NETPRIO_CGROUP
	315	net_prio_subsys_id = -1;
	316	synchronize_rcu();
	317	#endif
	318
	319	rtnl_lock();
	320	for_each_netdev(&init_net, dev) {
	321	old = rtnl_dereference(dev->priomap);
2cfa5a04	322	RCU_INIT_POINTER(dev->priomap, NULL);
5bc1421e NH	323	if (old)
	324	kfree_rcu(old, rcu);
	325	}
	326	rtnl_unlock();
	327	}
	328
	329	module_init(init_cgroup_netprio);
	330	module_exit(exit_cgroup_netprio);
	331	MODULE_LICENSE("GPL v2");