linux/net/core/netclassid_cgroup.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

128 lines
2.8 KiB
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,
};