ipv6: Constify the sk parameter of several helper functions.

icmpv6_flow_init(), ip6_datagram_flow_key_init() and ip6_mc_hdr() don't
need to modify their sk argument. Make that explicit using const.

Signed-off-by: Guillaume Nault <[e-mail]>
Reviewed-by: Simon Horman <[e-mail]>
Reviewed-by: David Ahern <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

include/linux/icmpv6.h

···
 
 struct flowi6;
 struct in6_addr;
-extern void				icmpv6_flow_init(struct sock *sk,
-							 struct flowi6 *fl6,
-							 u8 type,
-							 const struct in6_addr *saddr,
-							 const struct in6_addr *daddr,
-							 int oif);
+
+void icmpv6_flow_init(const struct sock *sk, struct flowi6 *fl6, u8 type,
+		      const struct in6_addr *saddr,
+		      const struct in6_addr *daddr, int oif);
 
 static inline void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos)
 {

net/ipv6/datagram.c

···
 	return ipv6_addr_v4mapped(a) && (a->s6_addr32[3] == 0);
 }
 
-static void ip6_datagram_flow_key_init(struct flowi6 *fl6, struct sock *sk)
+static void ip6_datagram_flow_key_init(struct flowi6 *fl6,
+				       const struct sock *sk)
 {
-	struct inet_sock *inet = inet_sk(sk);
-	struct ipv6_pinfo *np = inet6_sk(sk);
+	const struct inet_sock *inet = inet_sk(sk);
+	const struct ipv6_pinfo *np = inet6_sk(sk);
 	int oif = sk->sk_bound_dev_if;
 
 	memset(fl6, 0, sizeof(*fl6));

net/ipv6/icmp.c

···
 	return 0;
 }
 
-void icmpv6_flow_init(struct sock *sk, struct flowi6 *fl6,
-		      u8 type,
+void icmpv6_flow_init(const struct sock *sk, struct flowi6 *fl6, u8 type,
 		      const struct in6_addr *saddr,
-		      const struct in6_addr *daddr,
-		      int oif)
+		      const struct in6_addr *daddr, int oif)
 {
 	memset(fl6, 0, sizeof(*fl6));
 	fl6->saddr = *saddr;

net/ipv6/mcast.c

···
 	return scount;
 }
 
-static void ip6_mc_hdr(struct sock *sk, struct sk_buff *skb,
-		       struct net_device *dev,
-		       const struct in6_addr *saddr,
-		       const struct in6_addr *daddr,
-		       int proto, int len)
+static void ip6_mc_hdr(const struct sock *sk, struct sk_buff *skb,
+		       struct net_device *dev, const struct in6_addr *saddr,
+		       const struct in6_addr *daddr, int proto, int len)
 {
 	struct ipv6hdr *hdr;