Commit fe1217c4 authored by Daniel Borkmann's avatar Daniel Borkmann Committed by Pablo Neira Ayuso
Browse files

net: net_cls: move cgroupfs classid handling into core 

Zefan Li requested [1] to perform the following cleanup/refactoring:

- Split cgroupfs classid handling into net core to better express a
  possible more generic use.

- Disable module support for cgroupfs bits as the majority of other
  cgroupfs subsystems do not have that, and seems to be not wished
  from cgroup side. Zefan probably might want to follow-up for netprio
  later on.

- By this, code can be further reduced which previously took care of
  functionality built when compiled as module.

cgroupfs bits are being placed under net/core/netclassid_cgroup.c, so
that we are consistent with {netclassid,netprio}_cgroup naming that is
under net/core/ as suggested by Zefan.

No change in functionality, but only code refactoring that is being
done here.

 [1] http://patchwork.ozlabs.org/patch/304825/



Suggested-by: default avatarLi Zefan <lizefan@huawei.com>
Signed-off-by: default avatarDaniel Borkmann <dborkman@redhat.com>
Cc: Zefan Li <lizefan@huawei.com>
Cc: Thomas Graf <tgraf@suug.ch>
Cc: cgroups@vger.kernel.org
Acked-by: default avatarLi Zefan <lizefan@huawei.com>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 14abfa16

include/linux/cgroup_subsys.h

+1 −1
Original line number Diff line number Diff line
@@ -31,7 +31,7 @@ SUBSYS(devices) 
SUBSYS(freezer)

#endif



#if IS_SUBSYS_ENABLED(CONFIG_NET_CLS_CGROUP)

#if IS_SUBSYS_ENABLED(CONFIG_CGROUP_NET_CLASSID)

SUBSYS(net_cls)

#endif

include/net/cls_cgroup.h

+12 −28
Original line number Diff line number Diff line
@@ -16,17 +16,16 @@ 
#include <linux/cgroup.h>

#include <linux/hardirq.h>

#include <linux/rcupdate.h>

#include <net/sock.h>



#if IS_ENABLED(CONFIG_NET_CLS_CGROUP)

struct cgroup_cls_state

{

#ifdef CONFIG_CGROUP_NET_CLASSID

struct cgroup_cls_state {

	struct cgroup_subsys_state css;

	u32 classid;

};



void sock_update_classid(struct sock *sk);

struct cgroup_cls_state *task_cls_state(struct task_struct *p);



#if IS_BUILTIN(CONFIG_NET_CLS_CGROUP)

static inline u32 task_cls_classid(struct task_struct *p)

{

	u32 classid;
@@ -41,33 +40,18 @@ static inline u32 task_cls_classid(struct task_struct *p) 


	return classid;

}

#elif IS_MODULE(CONFIG_NET_CLS_CGROUP)

static inline u32 task_cls_classid(struct task_struct *p)

{

	struct cgroup_subsys_state *css;

	u32 classid = 0;



	if (in_interrupt())

		return 0;



	rcu_read_lock();

	css = task_css(p, net_cls_subsys_id);

	if (css)

		classid = container_of(css,

				       struct cgroup_cls_state, css)->classid;

	rcu_read_unlock();



	return classid;

}

#endif

#else /* !CGROUP_NET_CLS_CGROUP */

static inline void sock_update_classid(struct sock *sk)

{

}

	u32 classid;



static inline u32 task_cls_classid(struct task_struct *p)

	classid = task_cls_classid(current);

	if (classid != sk->sk_classid)

		sk->sk_classid = classid;

}

#else /* !CONFIG_CGROUP_NET_CLASSID */

static inline void sock_update_classid(struct sock *sk)

{

	return 0;

}

#endif /* CGROUP_NET_CLS_CGROUP */

#endif /* CONFIG_CGROUP_NET_CLASSID */

#endif  /* _NET_CLS_CGROUP_H */

net/Kconfig

+7 −0
Original line number Diff line number Diff line
@@ -245,6 +245,13 @@ config NETPRIO_CGROUP 
	  Cgroup subsystem for use in assigning processes to network priorities on

	  a per-interface basis



config CGROUP_NET_CLASSID

	boolean "Network classid cgroup"

	depends on CGROUPS

	---help---

	  Cgroup subsystem for use as general purpose socket classid marker that is

	  being used in cls_cgroup and for netfilter matching.



config NET_RX_BUSY_POLL

	boolean

	default y

net/core/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -22,3 +22,4 @@ obj-$(CONFIG_TRACEPOINTS) += net-traces.o 
obj-$(CONFIG_NET_DROP_MONITOR) += drop_monitor.o

obj-$(CONFIG_NETWORK_PHY_TIMESTAMPING) += timestamping.o

obj-$(CONFIG_NETPRIO_CGROUP) += netprio_cgroup.o

obj-$(CONFIG_CGROUP_NET_CLASSID) += netclassid_cgroup.o

net/core/netclassid_cgroup.c

0 → 100644
+120 −0
Original line number Diff line number Diff line 
/*

 * 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(p, net_cls_subsys_id));

}

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(css));



	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, css, 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_subsys = {

	.name			= "net_cls",

	.css_alloc		= cgrp_css_alloc,

	.css_online		= cgrp_css_online,

	.css_free		= cgrp_css_free,

	.attach			= cgrp_attach,

	.subsys_id		= net_cls_subsys_id,

	.base_cftypes		= ss_files,

	.module			= THIS_MODULE,

};



static int __init init_netclassid_cgroup(void)

{

	return cgroup_load_subsys(&net_cls_subsys);

}

__initcall(init_netclassid_cgroup);

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