net: icmp: introduce function icmpv6_param_prob_reason()

In order to add the skb drop reasons support to icmpv6_param_prob(),
introduce the function icmpv6_param_prob_reason() and make
icmpv6_param_prob() an inline call to it. This new function will be
used in the following patches.
Signed-off-by: Menglong Dong <imagedong@tencent.com>
Reviewed-by: Jiang Biao <benbjiang@tencent.com>
Reviewed-by: Hao Peng <flyingpeng@tencent.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/icmpv6.h

@@ -79,8 +79,9 @@ extern int				icmpv6_init(void);
 extern int				icmpv6_err_convert(u8 type, u8 code,
 							   int *err);
 extern void				icmpv6_cleanup(void);
-extern void				icmpv6_param_prob(struct sk_buff *skb,
-							  u8 code, int pos);
+extern void				icmpv6_param_prob_reason(struct sk_buff *skb,
+								 u8 code, int pos,
+								 enum skb_drop_reason reason);
 
 struct flowi6;
 struct in6_addr;
@@ -91,6 +92,12 @@ extern void				icmpv6_flow_init(struct sock *sk,
 							 const struct in6_addr *daddr,
 							 int oif);
 
+static inline void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos)
+{
+	icmpv6_param_prob_reason(skb, code, pos,
+				 SKB_DROP_REASON_NOT_SPECIFIED);
+}
+
 static inline bool icmpv6_is_err(int type)
 {
 	switch (type) {

net/ipv6/icmp.c

@@ -629,12 +629,13 @@ void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info,
 }
 EXPORT_SYMBOL(icmp6_send);
 
-/* Slightly more convenient version of icmp6_send.
+/* Slightly more convenient version of icmp6_send with drop reasons.
  */
-void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos)
+void icmpv6_param_prob_reason(struct sk_buff *skb, u8 code, int pos,
+			      enum skb_drop_reason reason)
 {
 	icmp6_send(skb, ICMPV6_PARAMPROB, code, pos, NULL, IP6CB(skb));
-	kfree_skb(skb);
+	kfree_skb_reason(skb, reason);
 }
 
 /* Generate icmpv6 with type/code ICMPV6_DEST_UNREACH/ICMPV6_ADDR_UNREACH