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, 6 insertions, 21 deletions

diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 2b7c3a100e2c..e487080d02db 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -129,7 +129,7 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
         struct inet_connection_sock *icsk = inet_csk(sk);
         struct ipv6_pinfo *np = inet6_sk(sk);
         struct tcp_sock *tp = tcp_sk(sk);
-        struct in6_addr *saddr = NULL, *final_p = NULL, final;
+        struct in6_addr *saddr = NULL, *final_p, final;
         struct flowi fl;
         struct dst_entry *dst;
         int addr_type;
@@ -250,12 +250,7 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
         fl.fl_ip_dport = usin->sin6_port;
         fl.fl_ip_sport = inet->inet_sport;
 
-        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);
 
         security_sk_classify_flow(sk, &fl);
 
@@ -477,7 +472,7 @@ static int tcp_v6_send_synack(struct sock *sk, struct request_sock *req,
         struct ipv6_pinfo *np = inet6_sk(sk);
         struct sk_buff * skb;
         struct ipv6_txoptions *opt = NULL;
-        struct in6_addr * final_p = NULL, final;
+        struct in6_addr * final_p, final;
         struct flowi fl;
         struct dst_entry *dst;
         int err = -1;
@@ -494,12 +489,7 @@ static int tcp_v6_send_synack(struct sock *sk, struct request_sock *req,
         security_req_classify_flow(req, &fl);
 
         opt = np->opt;
-        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;
-        }
+        final_p = fl6_update_dst(&fl, opt, &final);
 
         err = ip6_dst_lookup(sk, &dst, &fl);
         if (err)
@@ -1392,18 +1382,13 @@ static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
                 goto out_overflow;
 
         if (dst == NULL) {
-                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, &treq->rmt_addr);
-                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;
-                }
+                final_p = fl6_update_dst(&fl, opt, &final);
                 ipv6_addr_copy(&fl.fl6_src, &treq->loc_addr);
                 fl.oif = sk->sk_bound_dev_if;
                 fl.mark = sk->sk_mark;