[PATCH net-next 5/5] tcp: TFO - cleanup code duplication

[Christoph Paasch]

We can actually easily reuse __tcp_fastopen_cookie_gen_with_ctx to
generate the cookie based on a give TFO-context.

This cleans up some of the code.

Signed-off-by: Christoph Paasch <cpaa...@apple.com>
---
 net/ipv4/tcp_fastopen.c | 51 +++++++++++--------------------------------------
 1 file changed, 11 insertions(+), 40 deletions(-)

diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c
index e856262ef4c2..81e8b3ae9ecd 100644
--- a/net/ipv4/tcp_fastopen.c
+++ b/net/ipv4/tcp_fastopen.c
@@ -155,27 +155,6 @@ error:             kfree(ctx);
        return err;
 }
 
-static bool __tcp_fastopen_cookie_gen(struct sock *sk, const void *path,
-                                     struct tcp_fastopen_cookie *foc)
-{
-       struct tcp_fastopen_context *ctx;
-       bool ok = false;
-
-       rcu_read_lock();
-
-       ctx = rcu_dereference(inet_csk(sk)->icsk_accept_queue.fastopenq.ctx);
-       if (!ctx)
-               ctx = rcu_dereference(sock_net(sk)->ipv4.tcp_fastopen_ctx);
-
-       if (ctx) {
-               crypto_cipher_encrypt_one(ctx->tfm, foc->val, path);
-               foc->len = TCP_FASTOPEN_COOKIE_SIZE;
-               ok = true;
-       }
-       rcu_read_unlock();
-       return ok;
-}
-
 static void __tcp_fastopen_cookie_gen_with_ctx(struct request_sock *req,
                                               struct sk_buff *syn,
                                               struct tcp_fastopen_cookie *foc,
@@ -222,29 +201,21 @@ static bool tcp_fastopen_cookie_gen(struct sock *sk,
                                    struct sk_buff *syn,
                                    struct tcp_fastopen_cookie *foc)
 {
-       if (req->rsk_ops->family == AF_INET) {
-               const struct iphdr *iph = ip_hdr(syn);
-
-               __be32 path[4] = { iph->saddr, iph->daddr, 0, 0 };
-               return __tcp_fastopen_cookie_gen(sk, path, foc);
-       }
+       struct tcp_fastopen_context *ctx;
+       bool ok = false;
 
-#if IS_ENABLED(CONFIG_IPV6)
-       if (req->rsk_ops->family == AF_INET6) {
-               const struct ipv6hdr *ip6h = ipv6_hdr(syn);
-               struct tcp_fastopen_cookie tmp;
+       rcu_read_lock();
 
-               if (__tcp_fastopen_cookie_gen(sk, &ip6h->saddr, &tmp)) {
-                       struct in6_addr *buf = &tmp.addr;
-                       int i;
+       ctx = rcu_dereference(inet_csk(sk)->icsk_accept_queue.fastopenq.ctx);
+       if (!ctx)
+               ctx = rcu_dereference(sock_net(sk)->ipv4.tcp_fastopen_ctx);
 
-                       for (i = 0; i < 4; i++)
-                               buf->s6_addr32[i] ^= ip6h->daddr.s6_addr32[i];
-                       return __tcp_fastopen_cookie_gen(sk, buf, foc);
-               }
+       if (ctx) {
+               __tcp_fastopen_cookie_gen_with_ctx(req, syn, foc, ctx);
+               ok = true;
        }
-#endif
-       return false;
+       rcu_read_unlock();
+       return ok;
 }
 
 
-- 
2.16.2