[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/module.h>
#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(const void *v, struct file *file, unsigned n)
{
	int err;
	struct socket *sock = sock_from_file(file, &err);

	if (sock)
		sock->sk->sk_classid = (u32)(unsigned long)v;

	return 0;
}

static void cgrp_attach(struct cgroup_subsys_state *css,
			struct cgroup_taskset *tset)
{
	struct cgroup_cls_state *cs = css_cls_state(css);
	void *v = (void *)(unsigned long)cs->classid;
	struct task_struct *p;

	cgroup_taskset_for_each(p, tset) {
		task_lock(p);
		iterate_fd(p->files, 0, update_classid, v);
		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)
{
	css_cls_state(css)->classid = (u32) value;

	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
	12	#include <linux/module.h>
	13	#include <linux/slab.h>
	14	#include <linux/cgroup.h>
	15	#include <linux/fdtable.h>
	16	#include <net/cls_cgroup.h>
	17	#include <net/sock.h>
	18
	19	static inline struct cgroup_cls_state css_cls_state(struct cgroup_subsys_state css)
	20	{
	21	return css ? container_of(css, struct cgroup_cls_state, css) : NULL;
	22	}
	23
	24	struct cgroup_cls_state task_cls_state(struct task_struct p)
	25	{
cc9f4daa KK	26	return css_cls_state(task_css_check(p, net_cls_cgrp_id,
cc9f4daa KK	27	rcu_read_lock_bh_held()));
fe1217c4 DB	28	}
	29	EXPORT_SYMBOL_GPL(task_cls_state);
	30
	31	static struct cgroup_subsys_state *
	32	cgrp_css_alloc(struct cgroup_subsys_state *parent_css)
	33	{
	34	struct cgroup_cls_state *cs;
	35
	36	cs = kzalloc(sizeof(*cs), GFP_KERNEL);
	37	if (!cs)
	38	return ERR_PTR(-ENOMEM);
	39
	40	return &cs->css;
	41	}
	42
	43	static int cgrp_css_online(struct cgroup_subsys_state *css)
	44	{
	45	struct cgroup_cls_state *cs = css_cls_state(css);
5c9d535b	46	struct cgroup_cls_state *parent = css_cls_state(css->parent);
fe1217c4 DB	47
	48	if (parent)
	49	cs->classid = parent->classid;
	50
	51	return 0;
	52	}
	53
	54	static void cgrp_css_free(struct cgroup_subsys_state *css)
	55	{
	56	kfree(css_cls_state(css));
	57	}
	58
	59	static int update_classid(const void v, struct file file, unsigned n)
	60	{
	61	int err;
	62	struct socket *sock = sock_from_file(file, &err);
	63
	64	if (sock)
	65	sock->sk->sk_classid = (u32)(unsigned long)v;
	66
	67	return 0;
	68	}
	69
	70	static void cgrp_attach(struct cgroup_subsys_state *css,
	71	struct cgroup_taskset *tset)
	72	{
	73	struct cgroup_cls_state *cs = css_cls_state(css);
	74	void v = (void )(unsigned long)cs->classid;
	75	struct task_struct *p;
	76
924f0d9a	77	cgroup_taskset_for_each(p, tset) {
fe1217c4 DB	78	task_lock(p);
	79	iterate_fd(p->files, 0, update_classid, v);
	80	task_unlock(p);
	81	}
	82	}
	83
	84	static u64 read_classid(struct cgroup_subsys_state css, struct cftype cft)
	85	{
	86	return css_cls_state(css)->classid;
	87	}
	88
	89	static int write_classid(struct cgroup_subsys_state css, struct cftype cft,
	90	u64 value)
	91	{
	92	css_cls_state(css)->classid = (u32) value;
	93
	94	return 0;
	95	}
	96
	97	static struct cftype ss_files[] = {
	98	{
	99	.name = "classid",
	100	.read_u64 = read_classid,
	101	.write_u64 = write_classid,
	102	},
	103	{ } /* terminate */
	104	};
	105
073219e9	106	struct cgroup_subsys net_cls_cgrp_subsys = {
fe1217c4 DB	107	.css_alloc = cgrp_css_alloc,
	108	.css_online = cgrp_css_online,
	109	.css_free = cgrp_css_free,
	110	.attach = cgrp_attach,
5577964e	111	.legacy_cftypes = ss_files,
fe1217c4	112	};