[RFC v2 08/14] tcp_md5: Detect key inside tcp_v4_send_ack instead of passing it as an argument

[Christoph Paasch]

This will simplify to consolidate the TCP_MD5-code into a single place.

Cc: Ivan Delalande <col...@arista.com>
Signed-off-by: Christoph Paasch <cpaa...@apple.com>
Reviewed-by: Mat Martineau <mathew.j.martin...@linux.intel.com>
---
 net/ipv4/tcp_ipv4.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 4112594d04be..4211f8e38ef9 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -764,7 +764,6 @@ static void tcp_v4_send_reset(const struct sock *sk, struct 
sk_buff *skb)
 static void tcp_v4_send_ack(const struct sock *sk,
                            struct sk_buff *skb, u32 seq, u32 ack,
                            u32 win, u32 tsval, u32 tsecr, int oif,
-                           struct tcp_md5sig_key *key,
                            int reply_flags, u8 tos)
 {
        const struct tcphdr *th = tcp_hdr(skb);
@@ -773,6 +772,9 @@ static void tcp_v4_send_ack(const struct sock *sk,
                __be32 opt[(MAX_TCP_OPTION_SPACE >> 2)];
        } rep;
        struct hlist_head *extopt_list = NULL;
+#ifdef CONFIG_TCP_MD5SIG
+       struct tcp_md5sig_key *key;
+#endif
        struct net *net = sock_net(sk);
        struct ip_reply_arg arg;
        int offset = 0;
@@ -803,6 +805,17 @@ static void tcp_v4_send_ack(const struct sock *sk,
        rep.th.ack     = 1;
        rep.th.window  = htons(win);
 
+#ifdef CONFIG_TCP_MD5SIG
+       if (sk->sk_state == TCP_TIME_WAIT) {
+               key = tcp_twsk_md5_key(tcp_twsk(sk));
+       } else if (sk->sk_state == TCP_NEW_SYN_RECV) {
+               key = tcp_md5_do_lookup(sk, (union tcp_md5_addr 
*)&ip_hdr(skb)->saddr,
+                                       AF_INET);
+       } else {
+               key = NULL;     /* Should not happen */
+       }
+#endif
+
        if (unlikely(extopt_list && !hlist_empty(extopt_list))) {
                unsigned int remaining;
                struct tcp_out_options opts;
@@ -872,7 +885,6 @@ static void tcp_v4_timewait_ack(struct sock *sk, struct 
sk_buff *skb)
                        tcp_time_stamp_raw() + tcptw->tw_ts_offset,
                        tcptw->tw_ts_recent,
                        tw->tw_bound_dev_if,
-                       tcp_twsk_md5_key(tcptw),
                        tw->tw_transparent ? IP_REPLY_ARG_NOSRCCHECK : 0,
                        tw->tw_tos
                        );
@@ -900,8 +912,6 @@ static void tcp_v4_reqsk_send_ack(const struct sock *sk, 
struct sk_buff *skb,
                        tcp_time_stamp_raw() + tcp_rsk(req)->ts_off,
                        req->ts_recent,
                        0,
-                       tcp_md5_do_lookup(sk, (union tcp_md5_addr 
*)&ip_hdr(skb)->saddr,
-                                         AF_INET),
                        inet_rsk(req)->no_srccheck ? IP_REPLY_ARG_NOSRCCHECK : 
0,
                        ip_hdr(skb)->tos);
 }
-- 
2.16.1