LXR linux/include/net/cls

   1/* SPDX-License-Identifier: GPL-2.0-or-later */
   2/*
   3 * cls_cgroup.h                 Control Group Classifier
   4 *
   5 * Authors:     Thomas Graf <tgraf@suug.ch>
   6 */
   7
   8#ifndef _NET_CLS_CGROUP_H
   9#define _NET_CLS_CGROUP_H
  10
  11#include <linux/cgroup.h>
  12#include <linux/hardirq.h>
  13#include <linux/rcupdate.h>
  14#include <net/sock.h>
  15#include <net/inet_sock.h>
  16
  17#ifdef CONFIG_CGROUP_NET_CLASSID
  18struct cgroup_cls_state {
  19        struct cgroup_subsys_state css;
  20        u32 classid;
  21};
  22
  23struct cgroup_cls_state *task_cls_state(struct task_struct *p);
  24
  25static inline u32 task_cls_classid(struct task_struct *p)
  26{
  27        u32 classid;
  28
  29        if (in_interrupt())
  30                return 0;
  31
  32        rcu_read_lock();
  33        classid = container_of(task_css(p, net_cls_cgrp_id),
  34                               struct cgroup_cls_state, css)->classid;
  35        rcu_read_unlock();
  36
  37        return classid;
  38}
  39
  40static inline void sock_update_classid(struct sock_cgroup_data *skcd)
  41{
  42        u32 classid;
  43
  44        classid = task_cls_classid(current);
  45        sock_cgroup_set_classid(skcd, classid);
  46}
  47
  48static inline u32 __task_get_classid(struct task_struct *task)
  49{
  50        return task_cls_state(task)->classid;
  51}
  52
  53static inline u32 task_get_classid(const struct sk_buff *skb)
  54{
  55        u32 classid = __task_get_classid(current);
  56
  57        /* Due to the nature of the classifier it is required to ignore all
  58         * packets originating from softirq context as accessing `current'
  59         * would lead to false results.
  60         *
  61         * This test assumes that all callers of dev_queue_xmit() explicitly
  62         * disable bh. Knowing this, it is possible to detect softirq based
  63         * calls by looking at the number of nested bh disable calls because
  64         * softirqs always disables bh.
  65         */
  66        if (in_serving_softirq()) {
  67                struct sock *sk = skb_to_full_sk(skb);
  68
  69                /* If there is an sock_cgroup_classid we'll use that. */
  70                if (!sk || !sk_fullsock(sk))
  71                        return 0;
  72
  73                classid = sock_cgroup_classid(&sk->sk_cgrp_data);
  74        }
  75
  76        return classid;
  77}
  78#else /* !CONFIG_CGROUP_NET_CLASSID */
  79static inline void sock_update_classid(struct sock_cgroup_data *skcd)
  80{
  81}
  82
  83static inline u32 task_get_classid(const struct sk_buff *skb)
  84{
  85        return 0;
  86}
  87#endif /* CONFIG_CGROUP_NET_CLASSID */
  88#endif  /* _NET_CLS_CGROUP_H */
  89