ipv6: icmp6: add SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS

This is a generic drop reason for any error detected
in ndisc_parse_options().
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/net/dropreason.h

@@ -76,6 +76,7 @@
 	FN(IPV6_NDISC_FRAG)		\
 	FN(IPV6_NDISC_HOP_LIMIT)	\
 	FN(IPV6_NDISC_BAD_CODE)		\
+	FN(IPV6_NDISC_BAD_OPTIONS)	\
 	FNe(MAX)
 
 /**
@@ -330,6 +331,8 @@ enum skb_drop_reason {
 	SKB_DROP_REASON_IPV6_NDISC_HOP_LIMIT,
 	/** @SKB_DROP_REASON_IPV6_NDISC_BAD_CODE: invalid NDISC icmp6 code. */
 	SKB_DROP_REASON_IPV6_NDISC_BAD_CODE,
+	/** @SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS: invalid NDISC options. */
+	SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS,
 	/**
 	 * @SKB_DROP_REASON_MAX: the maximum of drop reason, which shouldn't be
 	 * used as a real 'reason'

net/ipv6/ndisc.c

@@ -819,10 +819,8 @@ static enum skb_drop_reason ndisc_recv_ns(struct sk_buff *skb)
 		return reason;
 	}
 
-	if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
-		ND_PRINTK(2, warn, "NS: invalid ND options\n");
-		return reason;
-	}
+	if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts))
+		return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
 
 	if (ndopts.nd_opts_src_lladdr) {
 		lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev);
@@ -1026,10 +1024,9 @@ static enum skb_drop_reason ndisc_recv_na(struct sk_buff *skb)
 	    idev->cnf.drop_unsolicited_na)
 		return reason;
 
-	if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
-		ND_PRINTK(2, warn, "NS: invalid ND option\n");
-		return reason;
-	}
+	if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts))
+		return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
+
 	if (ndopts.nd_opts_tgt_lladdr) {
 		lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
 		if (!lladdr) {
@@ -1159,10 +1156,8 @@ static enum skb_drop_reason ndisc_recv_rs(struct sk_buff *skb)
 		goto out;
 
 	/* Parse ND options */
-	if (!ndisc_parse_options(skb->dev, rs_msg->opt, ndoptlen, &ndopts)) {
-		ND_PRINTK(2, notice, "NS: invalid ND option, ignored\n");
-		goto out;
-	}
+	if (!ndisc_parse_options(skb->dev, rs_msg->opt, ndoptlen, &ndopts))
+		return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
 
 	if (ndopts.nd_opts_src_lladdr) {
 		lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr,
@@ -1280,10 +1275,8 @@ static enum skb_drop_reason ndisc_router_discovery(struct sk_buff *skb)
 		return reason;
 	}
 
-	if (!ndisc_parse_options(skb->dev, opt, optlen, &ndopts)) {
-		ND_PRINTK(2, warn, "RA: invalid ND options\n");
-		return reason;
-	}
+	if (!ndisc_parse_options(skb->dev, opt, optlen, &ndopts))
+		return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
 
 	if (!ipv6_accept_ra(in6_dev)) {
 		ND_PRINTK(2, info,
@@ -1627,7 +1620,7 @@ static enum skb_drop_reason ndisc_redirect_rcv(struct sk_buff *skb)
 	}
 
 	if (!ndisc_parse_options(skb->dev, msg->opt, ndoptlen, &ndopts))
-		return reason;
+		return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
 
 	if (!ndopts.nd_opts_rh) {
 		ip6_redirect_no_header(skb, dev_net(skb->dev),