ipv6: Refactor update of IPv6 flowi destination address for srcrt (RH) option

There are more than a dozen occurrences of following code in the
IPv6 stack:

    if (opt && opt->srcrt) {
            struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
            ipv6_addr_copy(&final, &fl.fl6_dst);
            ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
            final_p = &final;
    }

Replace those with a helper. Note that the helper overrides final_p
in all cases. This is ok as final_p was previously initialized to
NULL when declared.

Signed-off-by: Arnaud Ebalard <arno@natisbad.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 7 deletions

diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c
index 34d1f0690d7e..12383705dbad 100644
--- a/net/ipv6/syncookies.c
+++ b/net/ipv6/syncookies.c
@@ -240,17 +240,12 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
          * me if there is a preferred way.
          */
         {
-                struct in6_addr *final_p = NULL, final;
+                struct in6_addr *final_p, final;
                 struct flowi fl;
                 memset(&fl, 0, sizeof(fl));
                 fl.proto = IPPROTO_TCP;
                 ipv6_addr_copy(&fl.fl6_dst, &ireq6->rmt_addr);
-                if (np->opt && np->opt->srcrt) {
-                        struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
-                        ipv6_addr_copy(&final, &fl.fl6_dst);
-                        ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
-                        final_p = &final;
-                }
+                final_p = fl6_update_dst(&fl, np->opt, &final);
                 ipv6_addr_copy(&fl.fl6_src, &ireq6->loc_addr);
                 fl.oif = sk->sk_bound_dev_if;
                 fl.mark = sk->sk_mark;