ipv6: use flag instead of u16 for hop in inet6_skb_parm

Hop was always either 0 or sizeof(struct ipv6hdr).

Signed-off-by: Florian Westphal <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

include/linux/ipv6.h

···
 struct inet6_skb_parm {
 	int			iif;
 	__be16			ra;
-	__u16			hop;
 	__u16			dst0;
 	__u16			srcrt;
 	__u16			dst1;
···
 #define IP6SKB_REROUTED		4
 #define IP6SKB_ROUTERALERT	8
 #define IP6SKB_FRAGMENTED      16
+#define IP6SKB_HOPBYHOP        32
 };
 
 #define IP6CB(skb)	((struct inet6_skb_parm*)((skb)->cb))

net/ipv6/af_inet6.c

···
 	const struct ipv6_pinfo *np = inet6_sk(sk);
 
 	if (np->rxopt.all) {
-		if ((opt->hop && (np->rxopt.bits.hopopts ||
-				  np->rxopt.bits.ohopopts)) ||
+		if (((opt->flags & IP6SKB_HOPBYHOP) &&
+		     (np->rxopt.bits.hopopts || np->rxopt.bits.ohopopts)) ||
 		    (ip6_flowinfo((struct ipv6hdr *) skb_network_header(skb)) &&
 		     np->rxopt.bits.rxflow) ||
 		    (opt->srcrt && (np->rxopt.bits.srcrt ||

net/ipv6/datagram.c

···
 	}
 
 	/* HbH is allowed only once */
-	if (np->rxopt.bits.hopopts && opt->hop) {
-		u8 *ptr = nh + opt->hop;
+	if (np->rxopt.bits.hopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
+		u8 *ptr = nh + sizeof(struct ipv6hdr);
 		put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 	}
 
···
 		int hlim = ipv6_hdr(skb)->hop_limit;
 		put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 	}
-	if (np->rxopt.bits.ohopopts && opt->hop) {
-		u8 *ptr = nh + opt->hop;
+	if (np->rxopt.bits.ohopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
+		u8 *ptr = nh + sizeof(struct ipv6hdr);
 		put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 	}
 	if (np->rxopt.bits.odstopts && opt->dst0) {

net/ipv6/exthdrs.c

···
 		return -1;
 	}
 
-	opt->hop = sizeof(struct ipv6hdr);
+	opt->flags |= IP6SKB_HOPBYHOP;
 	if (ip6_parse_tlv(tlvprochopopt_lst, skb)) {
 		skb->transport_header += (skb_transport_header(skb)[1] + 1) << 3;
 		opt = IP6CB(skb);