ndisc: Introduce ndisc_fill_redirect_hdr_option().

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 539b2ec37d3a4b99af849c673ce22601d441817e..53a545f326254995f62e365bf605face5e053305 100644 (file)
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -1341,6 +1341,19 @@ static void ndisc_redirect_rcv(struct sk_buff *skb)
        icmpv6_notify(skb, NDISC_REDIRECT, 0, 0);
 }
 
+static u8 *ndisc_fill_redirect_hdr_option(u8 *opt, struct sk_buff *orig_skb,
+                                         int rd_len)
+{
+       memset(opt, 0, 8);
+       *(opt++) = ND_OPT_REDIRECT_HDR;
+       *(opt++) = (rd_len >> 3);
+       opt += 6;
+
+       memcpy(opt, ipv6_hdr(orig_skb), rd_len - 8);
+
+       return opt + rd_len - 8;
+}
+
 void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
 {
        struct net_device *dev = skb->dev;
@@ -1470,12 +1483,8 @@ void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
         *      build redirect option and copy skb over to the new packet.
         */
 
-       memset(opt, 0, 8);
-       *(opt++) = ND_OPT_REDIRECT_HDR;
-       *(opt++) = (rd_len >> 3);
-       opt += 6;
-
-       memcpy(opt, ipv6_hdr(skb), rd_len - 8);
+       if (rd_len)
+               opt = ndisc_fill_redirect_hdr_option(opt, skb, rd_len);
 
        msg->icmph.icmp6_cksum = csum_ipv6_magic(&saddr_buf, &ipv6_hdr(skb)->saddr,
                                                 len, IPPROTO_ICMPV6,