1 files changed, 44 insertions, 29 deletions

diff --git a/include/net/cls_cgroup.h b/include/net/cls_cgroup.h
index 0fee0617fb7d..668aeee9b3f6 100644
--- a/include/net/cls_cgroup.h
+++ b/include/net/cls_cgroup.h
@@ -1,13 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
 /*
  * cls_cgroup.h			Control Group Classifier
  *
  * Authors:	Thomas Graf <tgraf@suug.ch>
- *
- * 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.
- *
  */
 
 #ifndef _NET_CLS_CGROUP_H
@@ -16,17 +11,17 @@
 #include <linux/cgroup.h>
 #include <linux/hardirq.h>
 #include <linux/rcupdate.h>
+#include <net/sock.h>
+#include <net/inet_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;
 };
 
-extern 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;
@@ -35,39 +30,59 @@ static inline u32 task_cls_classid(struct task_struct *p)
 		return 0;
 
 	rcu_read_lock();
-	classid = container_of(task_subsys_state(p, net_cls_subsys_id),
+	classid = container_of(task_css(p, net_cls_cgrp_id),
 			       struct cgroup_cls_state, css)->classid;
 	rcu_read_unlock();
 
 	return classid;
 }
-#elif IS_MODULE(CONFIG_NET_CLS_CGROUP)
-static inline u32 task_cls_classid(struct task_struct *p)
+
+static inline void sock_update_classid(struct sock_cgroup_data *skcd)
 {
-	struct cgroup_subsys_state *css;
-	u32 classid = 0;
+	u32 classid;
 
-	if (in_interrupt())
-		return 0;
+	classid = task_cls_classid(current);
+	sock_cgroup_set_classid(skcd, classid);
+}
 
-	rcu_read_lock();
-	css = task_subsys_state(p, net_cls_subsys_id);
-	if (css)
-		classid = container_of(css,
-				       struct cgroup_cls_state, css)->classid;
-	rcu_read_unlock();
+static inline u32 __task_get_classid(struct task_struct *task)
+{
+	return task_cls_state(task)->classid;
+}
+
+static inline u32 task_get_classid(const struct sk_buff *skb)
+{
+	u32 classid = __task_get_classid(current);
+
+	/* Due to the nature of the classifier it is required to ignore all
+	 * packets originating from softirq context as accessing `current'
+	 * would lead to false results.
+	 *
+	 * This test assumes that all callers of dev_queue_xmit() explicitly
+	 * disable bh. Knowing this, it is possible to detect softirq based
+	 * calls by looking at the number of nested bh disable calls because
+	 * softirqs always disables bh.
+	 */
+	if (softirq_count()) {
+		struct sock *sk = skb_to_full_sk(skb);
+
+		/* If there is an sock_cgroup_classid we'll use that. */
+		if (!sk || !sk_fullsock(sk))
+			return 0;
+
+		classid = sock_cgroup_classid(&sk->sk_cgrp_data);
+	}
 
 	return classid;
 }
-#endif
-#else /* !CGROUP_NET_CLS_CGROUP */
-static inline void sock_update_classid(struct sock *sk)
+#else /* !CONFIG_CGROUP_NET_CLASSID */
+static inline void sock_update_classid(struct sock_cgroup_data *skcd)
 {
 }
 
-static inline u32 task_cls_classid(struct task_struct *p)
+static inline u32 task_get_classid(const struct sk_buff *skb)
 {
 	return 0;
 }
-#endif /* CGROUP_NET_CLS_CGROUP */
+#endif /* CONFIG_CGROUP_NET_CLASSID */
 #endif  /* _NET_CLS_CGROUP_H */