[NETFILTER]: nf_{conntrack,nat}_icmp: constify and annotate

Constify a few data tables use const qualifiers on variables where
possible in the nf_conntrack_icmp* sources.
Signed-off-by: NJan Engelhardt <jengelh@computergmbh.de>
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv4/netfilter/nf_conntrack_proto_icmp.c

@@ -26,7 +26,8 @@ static int icmp_pkt_to_tuple(const struct sk_buff *skb,
 			     unsigned int dataoff,
 			     struct nf_conntrack_tuple *tuple)
 {
-	struct icmphdr _hdr, *hp;
+	const struct icmphdr *hp;
+	struct icmphdr _hdr;
 
 	hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
 	if (hp == NULL)
@@ -129,8 +130,8 @@ icmp_error_message(struct sk_buff *skb,
 		 unsigned int hooknum)
 {
 	struct nf_conntrack_tuple innertuple, origtuple;
-	struct nf_conntrack_l4proto *innerproto;
-	struct nf_conntrack_tuple_hash *h;
+	const struct nf_conntrack_l4proto *innerproto;
+	const struct nf_conntrack_tuple_hash *h;
 
 	NF_CT_ASSERT(skb->nfct == NULL);
 
@@ -176,7 +177,8 @@ static int
 icmp_error(struct sk_buff *skb, unsigned int dataoff,
 	   enum ip_conntrack_info *ctinfo, int pf, unsigned int hooknum)
 {
-	struct icmphdr _ih, *icmph;
+	const struct icmphdr *icmph;
+	struct icmphdr _ih;
 
 	/* Not enough header? */
 	icmph = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_ih), &_ih);

net/ipv4/netfilter/nf_nat_proto_icmp.c

@@ -57,7 +57,7 @@ icmp_manip_pkt(struct sk_buff *skb,
 	       const struct nf_conntrack_tuple *tuple,
 	       enum nf_nat_manip_type maniptype)
 {
-	struct iphdr *iph = (struct iphdr *)(skb->data + iphdroff);
+	const struct iphdr *iph = (struct iphdr *)(skb->data + iphdroff);
 	struct icmphdr *hdr;
 	unsigned int hdroff = iphdroff + iph->ihl*4;
 

net/ipv6/netfilter/nf_conntrack_proto_icmpv6.c

@@ -32,7 +32,8 @@ static int icmpv6_pkt_to_tuple(const struct sk_buff *skb,
 			       unsigned int dataoff,
 			       struct nf_conntrack_tuple *tuple)
 {
-	struct icmp6hdr _hdr, *hp;
+	const struct icmp6hdr *hp;
+	struct icmp6hdr _hdr;
 
 	hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
 	if (hp == NULL)
@@ -45,7 +46,7 @@ static int icmpv6_pkt_to_tuple(const struct sk_buff *skb,
 }
 
 /* Add 1; spaces filled with 0. */
-static u_int8_t invmap[] = {
+static const u_int8_t invmap[] = {
 	[ICMPV6_ECHO_REQUEST - 128]	= ICMPV6_ECHO_REPLY + 1,
 	[ICMPV6_ECHO_REPLY - 128]	= ICMPV6_ECHO_REQUEST + 1,
 	[ICMPV6_NI_QUERY - 128]		= ICMPV6_NI_QUERY + 1,
@@ -105,7 +106,7 @@ static int icmpv6_new(struct nf_conn *ct,
 		      const struct sk_buff *skb,
 		      unsigned int dataoff)
 {
-	static u_int8_t valid_new[] = {
+	static const u_int8_t valid_new[] = {
 		[ICMPV6_ECHO_REQUEST - 128] = 1,
 		[ICMPV6_NI_QUERY - 128] = 1
 	};
@@ -129,8 +130,8 @@ icmpv6_error_message(struct sk_buff *skb,
 		     unsigned int hooknum)
 {
 	struct nf_conntrack_tuple intuple, origtuple;
-	struct nf_conntrack_tuple_hash *h;
-	struct nf_conntrack_l4proto *inproto;
+	const struct nf_conntrack_tuple_hash *h;
+	const struct nf_conntrack_l4proto *inproto;
 
 	NF_CT_ASSERT(skb->nfct == NULL);
 
@@ -176,7 +177,8 @@ static int
 icmpv6_error(struct sk_buff *skb, unsigned int dataoff,
 	     enum ip_conntrack_info *ctinfo, int pf, unsigned int hooknum)
 {
-	struct icmp6hdr _ih, *icmp6h;
+	const struct icmp6hdr *icmp6h;
+	struct icmp6hdr _ih;
 
 	icmp6h = skb_header_pointer(skb, dataoff, sizeof(_ih), &_ih);
 	if (icmp6h == NULL) {