tcp: move duplicate code from tcp_v4_init_sock()/tcp_v6_init_sock()
This commit moves the (substantial) common code shared between
tcp_v4_init_sock() and tcp_v6_init_sock() to a new address-family
independent function, tcp_init_sock().
Centralizing this functionality should help avoid drift issues,
e.g. where the IPv4 side is updated without a corresponding update to
IPv6. There was already some drift: IPv4 initialized snd_cwnd to
TCP_INIT_CWND, while the IPv6 side was still initializing snd_cwnd to
2 (in this case it should not matter, since snd_cwnd is also
initialized in tcp_init_metrics(), but the general risks and
maintenance overhead remain).
When diffing the old and new code, note that new tcp_init_sock()
function uses the order of steps from the tcp_v4_init_sock()
implementation (the order is slightly different in
tcp_v6_init_sock()).
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/tcp.h b/include/net/tcp.h
index b4ccb8a..fc880e9 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -395,6 +395,7 @@
extern void tcp_clear_retrans(struct tcp_sock *tp);
extern void tcp_update_metrics(struct sock *sk);
extern void tcp_close(struct sock *sk, long timeout);
+extern void tcp_init_sock(struct sock *sk);
extern unsigned int tcp_poll(struct file * file, struct socket *sock,
struct poll_table_struct *wait);
extern int tcp_getsockopt(struct sock *sk, int level, int optname,