153 lines
3.4 KiB
C
153 lines
3.4 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));
|
|
}
|
|
|
|
/*
|
|
* To avoid freezing of sockets creation for tasks with big number of threads
|
|
* and opened sockets lets release file_lock every 1000 iterated descriptors.
|
|
* New sockets will already have been created with new classid.
|
|
*/
|
|
|
|
struct update_classid_context {
|
|
u32 classid;
|
|
unsigned int batch;
|
|
};
|
|
|
|
#define UPDATE_CLASSID_BATCH 1000
|
|
|
|
static int update_classid_sock(const void *v, struct file *file, unsigned int n)
|
|
{
|
|
struct update_classid_context *ctx = (void *)v;
|
|
struct socket *sock = sock_from_file(file);
|
|
|
|
if (sock)
|
|
sock_cgroup_set_classid(&sock->sk->sk_cgrp_data, ctx->classid);
|
|
if (--ctx->batch == 0) {
|
|
ctx->batch = UPDATE_CLASSID_BATCH;
|
|
return n + 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void update_classid_task(struct task_struct *p, u32 classid)
|
|
{
|
|
struct update_classid_context ctx = {
|
|
.classid = classid,
|
|
.batch = UPDATE_CLASSID_BATCH
|
|
};
|
|
unsigned int fd = 0;
|
|
|
|
/* Only update the leader task, when many threads in this task,
|
|
* so it can avoid the useless traversal.
|
|
*/
|
|
if (p != p->group_leader)
|
|
return;
|
|
|
|
do {
|
|
task_lock(p);
|
|
fd = iterate_fd(p->files, fd, update_classid_sock, &ctx);
|
|
task_unlock(p);
|
|
cond_resched();
|
|
} while (fd);
|
|
}
|
|
|
|
static void cgrp_attach(struct cgroup_taskset *tset)
|
|
{
|
|
struct cgroup_subsys_state *css;
|
|
struct task_struct *p;
|
|
|
|
cgroup_taskset_for_each(p, css, tset) {
|
|
update_classid_task(p, css_cls_state(css)->classid);
|
|
}
|
|
}
|
|
|
|
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;
|
|
|
|
cs->classid = (u32)value;
|
|
|
|
css_task_iter_start(css, 0, &it);
|
|
while ((p = css_task_iter_next(&it)))
|
|
update_classid_task(p, cs->classid);
|
|
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,
|
|
};
|