911-kobject_add_broadcast_uevent.patch

From 0d37e6edc09c99e683dd91ca0e83bbc0df8477b3 Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@nbd.name>
Date: Sun, 16 Jul 2017 16:56:10 +0200
Subject: lib: add uevent_next_seqnum()

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 include/linux/kobject.h |  5 +++++
 lib/kobject_uevent.c    | 37 +++++++++++++++++++++++++++++++++++++
 2 files changed, 42 insertions(+)

--- a/include/linux/kobject.h
+++ b/include/linux/kobject.h
@@ -32,6 +32,8 @@
 #define UEVENT_NUM_ENVP			32	/* number of env pointers */
 #define UEVENT_BUFFER_SIZE		2048	/* buffer for the variables */
 
+struct sk_buff;
+
 #ifdef CONFIG_UEVENT_HELPER
 /* path to the userspace helper executed on an event */
 extern char uevent_helper[];
@@ -245,4 +247,7 @@ int kobject_synth_uevent(struct kobject
 __printf(2, 3)
 int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...);
 
+int broadcast_uevent(struct sk_buff *skb, __u32 pid, __u32 group,
+		     gfp_t allocation);
+
 #endif /* _KOBJECT_H_ */
--- a/lib/kobject_uevent.c
+++ b/lib/kobject_uevent.c
@@ -691,6 +691,43 @@ int add_uevent_var(struct kobj_uevent_en
 EXPORT_SYMBOL_GPL(add_uevent_var);
 
 #if defined(CONFIG_NET)
+int broadcast_uevent(struct sk_buff *skb, __u32 pid, __u32 group,
+		     gfp_t allocation)
+{
+	struct uevent_sock *ue_sk;
+	int err = 0;
+
+	/* send netlink message */
+	mutex_lock(&uevent_sock_mutex);
+	list_for_each_entry(ue_sk, &uevent_sock_list, list) {
+		struct sock *uevent_sock = ue_sk->sk;
+		struct sk_buff *skb2;
+
+		skb2 = skb_clone(skb, allocation);
+		if (!skb2)
+			break;
+
+		err = netlink_broadcast(uevent_sock, skb2, pid, group,
+					allocation);
+		if (err)
+			break;
+	}
+	mutex_unlock(&uevent_sock_mutex);
+
+	kfree_skb(skb);
+	return err;
+}
+#else
+int broadcast_uevent(struct sk_buff *skb, __u32 pid, __u32 group,
+		     gfp_t allocation)
+{
+	kfree_skb(skb);
+	return 0;
+}
+#endif
+EXPORT_SYMBOL_GPL(broadcast_uevent);
+
+#if defined(CONFIG_NET)
 static int uevent_net_broadcast(struct sock *usk, struct sk_buff *skb,
 				struct netlink_ext_ack *extack)
 {