[mirror_ubuntu-artful-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 <linux/sched/task.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>
f719ff9b IM	15	#include <linux/sched/task.h>
f719ff9b IM	16
fe1217c4 DB	17	#include <net/cls_cgroup.h>
	18	#include <net/sock.h>
	19
	20	static inline struct cgroup_cls_state css_cls_state(struct cgroup_subsys_state css)
	21	{
	22	return css ? container_of(css, struct cgroup_cls_state, css) : NULL;
	23	}
	24
	25	struct cgroup_cls_state task_cls_state(struct task_struct p)
	26	{
cc9f4daa KK	27	return css_cls_state(task_css_check(p, net_cls_cgrp_id,
cc9f4daa KK	28	rcu_read_lock_bh_held()));
fe1217c4 DB	29	}
	30	EXPORT_SYMBOL_GPL(task_cls_state);
	31
	32	static struct cgroup_subsys_state *
	33	cgrp_css_alloc(struct cgroup_subsys_state *parent_css)
	34	{
	35	struct cgroup_cls_state *cs;
	36
	37	cs = kzalloc(sizeof(*cs), GFP_KERNEL);
	38	if (!cs)
	39	return ERR_PTR(-ENOMEM);
	40
	41	return &cs->css;
	42	}
	43
	44	static int cgrp_css_online(struct cgroup_subsys_state *css)
	45	{
	46	struct cgroup_cls_state *cs = css_cls_state(css);
5c9d535b	47	struct cgroup_cls_state *parent = css_cls_state(css->parent);
fe1217c4 DB	48
	49	if (parent)
	50	cs->classid = parent->classid;
	51
	52	return 0;
	53	}
	54
	55	static void cgrp_css_free(struct cgroup_subsys_state *css)
	56	{
	57	kfree(css_cls_state(css));
	58	}
	59
3b13758f	60	static int update_classid_sock(const void v, struct file file, unsigned n)
fe1217c4 DB	61	{
	62	int err;
	63	struct socket *sock = sock_from_file(file, &err);
	64
bd1060a1 TH	65	if (sock) {
bd1060a1 TH	66	spin_lock(&cgroup_sk_update_lock);
2a56a1fe TH	67	sock_cgroup_set_classid(&sock->sk->sk_cgrp_data,
2a56a1fe TH	68	(unsigned long)v);
bd1060a1 TH	69	spin_unlock(&cgroup_sk_update_lock);
bd1060a1 TH	70	}
fe1217c4 DB	71	return 0;
	72	}
	73
a05d4fd9	74	static void cgrp_attach(struct cgroup_taskset *tset)
fe1217c4	75	{
a05d4fd9	76	struct cgroup_subsys_state *css;
fe1217c4 DB	77	struct task_struct *p;
fe1217c4 DB	78
a05d4fd9	79	cgroup_taskset_for_each(p, css, tset) {
fe1217c4	80	task_lock(p);
a05d4fd9 TH	81	iterate_fd(p->files, 0, update_classid_sock,
a05d4fd9 TH	82	(void *)(unsigned long)css_cls_state(css)->classid);
fe1217c4 DB	83	task_unlock(p);
	84	}
	85	}
	86
	87	static u64 read_classid(struct cgroup_subsys_state css, struct cftype cft)
	88	{
	89	return css_cls_state(css)->classid;
	90	}
	91
	92	static int write_classid(struct cgroup_subsys_state css, struct cftype cft,
	93	u64 value)
	94	{
3b13758f	95	struct cgroup_cls_state *cs = css_cls_state(css);
a05d4fd9 TH	96	struct css_task_iter it;
a05d4fd9 TH	97	struct task_struct *p;
3b13758f	98
bd1060a1 TH	99	cgroup_sk_alloc_disable();
bd1060a1 TH	100
3b13758f	101	cs->classid = (u32)value;
fe1217c4	102
a05d4fd9 TH	103	css_task_iter_start(css, &it);
	104	while ((p = css_task_iter_next(&it))) {
	105	task_lock(p);
	106	iterate_fd(p->files, 0, update_classid_sock,
	107	(void *)(unsigned long)cs->classid);
	108	task_unlock(p);
	109	}
	110	css_task_iter_end(&it);
	111
fe1217c4 DB	112	return 0;
	113	}
	114
	115	static struct cftype ss_files[] = {
	116	{
	117	.name = "classid",
	118	.read_u64 = read_classid,
	119	.write_u64 = write_classid,
	120	},
	121	{ } /* terminate */
	122	};
	123
073219e9	124	struct cgroup_subsys net_cls_cgrp_subsys = {
fe1217c4 DB	125	.css_alloc = cgrp_css_alloc,
	126	.css_online = cgrp_css_online,
	127	.css_free = cgrp_css_free,
	128	.attach = cgrp_attach,
5577964e	129	.legacy_cftypes = ss_files,
fe1217c4	130	};