[mirror_ubuntu-zesty-kernel.git] / net / core / netclassid_cgroup.c

/*
 * net/core/netclassid_cgroup.c	Classid Cgroupfs Handling
 *
 *		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:	Thomas Graf <tgraf@suug.ch>
 */

#include <linux/slab.h>
#include <linux/cgroup.h>
#include <linux/fdtable.h>
#include <net/cls_cgroup.h>
#include <net/sock.h>

static inline struct cgroup_cls_state *css_cls_state(struct cgroup_subsys_state *css)
{
	return css ? container_of(css, struct cgroup_cls_state, css) : NULL;
}

struct cgroup_cls_state *task_cls_state(struct task_struct *p)
{
	return css_cls_state(task_css_check(p, net_cls_cgrp_id,
					    rcu_read_lock_bh_held()));
}
EXPORT_SYMBOL_GPL(task_cls_state);

static struct cgroup_subsys_state *
cgrp_css_alloc(struct cgroup_subsys_state *parent_css)
{
	struct cgroup_cls_state *cs;

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

	return &cs->css;
}

static int cgrp_css_online(struct cgroup_subsys_state *css)
{
	struct cgroup_cls_state *cs = css_cls_state(css);
	struct cgroup_cls_state *parent = css_cls_state(css->parent);

	if (parent)
		cs->classid = parent->classid;

	return 0;
}

static void cgrp_css_free(struct cgroup_subsys_state *css)
{
	kfree(css_cls_state(css));
}

static int update_classid_sock(const void *v, struct file *file, unsigned n)
{
	int err;
	struct socket *sock = sock_from_file(file, &err);

	if (sock) {
		spin_lock(&cgroup_sk_update_lock);
		sock_cgroup_set_classid(&sock->sk->sk_cgrp_data,
					(unsigned long)v);
		spin_unlock(&cgroup_sk_update_lock);
	}
	return 0;
}

static void cgrp_attach(struct cgroup_taskset *tset)
{
	struct cgroup_subsys_state *css;
	struct task_struct *p;

	cgroup_taskset_for_each(p, css, tset) {
		task_lock(p);
		iterate_fd(p->files, 0, update_classid_sock,
			   (void *)(unsigned long)css_cls_state(css)->classid);
		task_unlock(p);
	}
}

static u64 read_classid(struct cgroup_subsys_state *css, struct cftype *cft)
{
	return css_cls_state(css)->classid;
}

static int write_classid(struct cgroup_subsys_state *css, struct cftype *cft,
			 u64 value)
{
	struct cgroup_cls_state *cs = css_cls_state(css);
	struct css_task_iter it;
	struct task_struct *p;

	cgroup_sk_alloc_disable();

	cs->classid = (u32)value;

	css_task_iter_start(css, &it);
	while ((p = css_task_iter_next(&it))) {
		task_lock(p);
		iterate_fd(p->files, 0, update_classid_sock,
			   (void *)(unsigned long)cs->classid);
		task_unlock(p);
	}
	css_task_iter_end(&it);

	return 0;
}

static struct cftype ss_files[] = {
	{
		.name		= "classid",
		.read_u64	= read_classid,
		.write_u64	= write_classid,
	},
	{ }	/* terminate */
};

struct cgroup_subsys net_cls_cgrp_subsys = {
	.css_alloc		= cgrp_css_alloc,
	.css_online		= cgrp_css_online,
	.css_free		= cgrp_css_free,
	.attach			= cgrp_attach,
	.legacy_cftypes		= ss_files,
};
Commit	Line	Data
fe1217c4 DB	1	/*
	2	* net/core/netclassid_cgroup.c Classid Cgroupfs Handling
	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: Thomas Graf <tgraf@suug.ch>
	10	*/
	11
fe1217c4 DB	12	#include <linux/slab.h>
	13	#include <linux/cgroup.h>
	14	#include <linux/fdtable.h>
	15	#include <net/cls_cgroup.h>
	16	#include <net/sock.h>
	17
	18	static inline struct cgroup_cls_state css_cls_state(struct cgroup_subsys_state css)
	19	{
	20	return css ? container_of(css, struct cgroup_cls_state, css) : NULL;
	21	}
	22
	23	struct cgroup_cls_state task_cls_state(struct task_struct p)
	24	{
cc9f4daa KK	25	return css_cls_state(task_css_check(p, net_cls_cgrp_id,
cc9f4daa KK	26	rcu_read_lock_bh_held()));
fe1217c4 DB	27	}
	28	EXPORT_SYMBOL_GPL(task_cls_state);
	29
	30	static struct cgroup_subsys_state *
	31	cgrp_css_alloc(struct cgroup_subsys_state *parent_css)
	32	{
	33	struct cgroup_cls_state *cs;
	34
	35	cs = kzalloc(sizeof(*cs), GFP_KERNEL);
	36	if (!cs)
	37	return ERR_PTR(-ENOMEM);
	38
	39	return &cs->css;
	40	}
	41
	42	static int cgrp_css_online(struct cgroup_subsys_state *css)
	43	{
	44	struct cgroup_cls_state *cs = css_cls_state(css);
5c9d535b	45	struct cgroup_cls_state *parent = css_cls_state(css->parent);
fe1217c4 DB	46
	47	if (parent)
	48	cs->classid = parent->classid;
	49
	50	return 0;
	51	}
	52
	53	static void cgrp_css_free(struct cgroup_subsys_state *css)
	54	{
	55	kfree(css_cls_state(css));
	56	}
	57
3b13758f	58	static int update_classid_sock(const void v, struct file file, unsigned n)
fe1217c4 DB	59	{
	60	int err;
	61	struct socket *sock = sock_from_file(file, &err);
	62
bd1060a1 TH	63	if (sock) {
bd1060a1 TH	64	spin_lock(&cgroup_sk_update_lock);
2a56a1fe TH	65	sock_cgroup_set_classid(&sock->sk->sk_cgrp_data,
2a56a1fe TH	66	(unsigned long)v);
bd1060a1 TH	67	spin_unlock(&cgroup_sk_update_lock);
bd1060a1 TH	68	}
fe1217c4 DB	69	return 0;
	70	}
	71
3c83da19	72	static void cgrp_attach(struct cgroup_taskset *tset)
fe1217c4	73	{
3c83da19	74	struct cgroup_subsys_state *css;
fe1217c4 DB	75	struct task_struct *p;
fe1217c4 DB	76
3c83da19	77	cgroup_taskset_for_each(p, css, tset) {
fe1217c4	78	task_lock(p);
3c83da19 TH	79	iterate_fd(p->files, 0, update_classid_sock,
3c83da19 TH	80	(void *)(unsigned long)css_cls_state(css)->classid);
fe1217c4 DB	81	task_unlock(p);
	82	}
	83	}
	84
	85	static u64 read_classid(struct cgroup_subsys_state css, struct cftype cft)
	86	{
	87	return css_cls_state(css)->classid;
	88	}
	89
	90	static int write_classid(struct cgroup_subsys_state css, struct cftype cft,
	91	u64 value)
	92	{
3b13758f	93	struct cgroup_cls_state *cs = css_cls_state(css);
3c83da19 TH	94	struct css_task_iter it;
3c83da19 TH	95	struct task_struct *p;
3b13758f	96
bd1060a1 TH	97	cgroup_sk_alloc_disable();
bd1060a1 TH	98
3b13758f	99	cs->classid = (u32)value;
fe1217c4	100
3c83da19 TH	101	css_task_iter_start(css, &it);
	102	while ((p = css_task_iter_next(&it))) {
	103	task_lock(p);
	104	iterate_fd(p->files, 0, update_classid_sock,
	105	(void *)(unsigned long)cs->classid);
	106	task_unlock(p);
	107	}
	108	css_task_iter_end(&it);
	109
fe1217c4 DB	110	return 0;
	111	}
	112
	113	static struct cftype ss_files[] = {
	114	{
	115	.name = "classid",
	116	.read_u64 = read_classid,
	117	.write_u64 = write_classid,
	118	},
	119	{ } /* terminate */
	120	};
	121
073219e9	122	struct cgroup_subsys net_cls_cgrp_subsys = {
fe1217c4 DB	123	.css_alloc = cgrp_css_alloc,
	124	.css_online = cgrp_css_online,
	125	.css_free = cgrp_css_free,
	126	.attach = cgrp_attach,
5577964e	127	.legacy_cftypes = ss_files,
fe1217c4	128	};