[linux-2.6-block.git] / net / core / netclassid_cgroup.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * net/core/netclassid_cgroup.c	Classid Cgroupfs Handling
 *
 * 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, 0, &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);
		cond_resched();
	}
	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
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
fe1217c4 DB	2	/*
	3	* net/core/netclassid_cgroup.c Classid Cgroupfs Handling
	4	*
fe1217c4 DB	5	* Authors: Thomas Graf <tgraf@suug.ch>
	6	*/
	7
fe1217c4 DB	8	#include <linux/slab.h>
	9	#include <linux/cgroup.h>
	10	#include <linux/fdtable.h>
f719ff9b IM	11	#include <linux/sched/task.h>
f719ff9b IM	12
fe1217c4 DB	13	#include <net/cls_cgroup.h>
	14	#include <net/sock.h>
	15
	16	static inline struct cgroup_cls_state css_cls_state(struct cgroup_subsys_state css)
	17	{
	18	return css ? container_of(css, struct cgroup_cls_state, css) : NULL;
	19	}
	20
	21	struct cgroup_cls_state task_cls_state(struct task_struct p)
	22	{
cc9f4daa KK	23	return css_cls_state(task_css_check(p, net_cls_cgrp_id,
cc9f4daa KK	24	rcu_read_lock_bh_held()));
fe1217c4 DB	25	}
	26	EXPORT_SYMBOL_GPL(task_cls_state);
	27
	28	static struct cgroup_subsys_state *
	29	cgrp_css_alloc(struct cgroup_subsys_state *parent_css)
	30	{
	31	struct cgroup_cls_state *cs;
	32
	33	cs = kzalloc(sizeof(*cs), GFP_KERNEL);
	34	if (!cs)
	35	return ERR_PTR(-ENOMEM);
	36
	37	return &cs->css;
	38	}
	39
	40	static int cgrp_css_online(struct cgroup_subsys_state *css)
	41	{
	42	struct cgroup_cls_state *cs = css_cls_state(css);
5c9d535b	43	struct cgroup_cls_state *parent = css_cls_state(css->parent);
fe1217c4 DB	44
	45	if (parent)
	46	cs->classid = parent->classid;
	47
	48	return 0;
	49	}
	50
	51	static void cgrp_css_free(struct cgroup_subsys_state *css)
	52	{
	53	kfree(css_cls_state(css));
	54	}
	55
3b13758f	56	static int update_classid_sock(const void v, struct file file, unsigned n)
fe1217c4 DB	57	{
	58	int err;
	59	struct socket *sock = sock_from_file(file, &err);
	60
bd1060a1 TH	61	if (sock) {
bd1060a1 TH	62	spin_lock(&cgroup_sk_update_lock);
2a56a1fe TH	63	sock_cgroup_set_classid(&sock->sk->sk_cgrp_data,
2a56a1fe TH	64	(unsigned long)v);
bd1060a1 TH	65	spin_unlock(&cgroup_sk_update_lock);
bd1060a1 TH	66	}
fe1217c4 DB	67	return 0;
	68	}
	69
a05d4fd9	70	static void cgrp_attach(struct cgroup_taskset *tset)
fe1217c4	71	{
a05d4fd9	72	struct cgroup_subsys_state *css;
fe1217c4 DB	73	struct task_struct *p;
fe1217c4 DB	74
a05d4fd9	75	cgroup_taskset_for_each(p, css, tset) {
fe1217c4	76	task_lock(p);
a05d4fd9 TH	77	iterate_fd(p->files, 0, update_classid_sock,
a05d4fd9 TH	78	(void *)(unsigned long)css_cls_state(css)->classid);
fe1217c4 DB	79	task_unlock(p);
	80	}
	81	}
	82
	83	static u64 read_classid(struct cgroup_subsys_state css, struct cftype cft)
	84	{
	85	return css_cls_state(css)->classid;
	86	}
	87
	88	static int write_classid(struct cgroup_subsys_state css, struct cftype cft,
	89	u64 value)
	90	{
3b13758f	91	struct cgroup_cls_state *cs = css_cls_state(css);
a05d4fd9 TH	92	struct css_task_iter it;
a05d4fd9 TH	93	struct task_struct *p;
3b13758f	94
bd1060a1 TH	95	cgroup_sk_alloc_disable();
bd1060a1 TH	96
3b13758f	97	cs->classid = (u32)value;
fe1217c4	98
bc2fb7ed	99	css_task_iter_start(css, 0, &it);
a05d4fd9 TH	100	while ((p = css_task_iter_next(&it))) {
	101	task_lock(p);
	102	iterate_fd(p->files, 0, update_classid_sock,
	103	(void *)(unsigned long)cs->classid);
	104	task_unlock(p);
a90e90b7	105	cond_resched();
a05d4fd9 TH	106	}
	107	css_task_iter_end(&it);
	108
fe1217c4 DB	109	return 0;
	110	}
	111
	112	static struct cftype ss_files[] = {
	113	{
	114	.name = "classid",
	115	.read_u64 = read_classid,
	116	.write_u64 = write_classid,
	117	},
	118	{ } /* terminate */
	119	};
	120
073219e9	121	struct cgroup_subsys net_cls_cgrp_subsys = {
fe1217c4 DB	122	.css_alloc = cgrp_css_alloc,
	123	.css_online = cgrp_css_online,
	124	.css_free = cgrp_css_free,
	125	.attach = cgrp_attach,
5577964e	126	.legacy_cftypes = ss_files,
fe1217c4	127	};