[INET_TWSK]: Introduce inet_twsk_alloc

With the parts of tcp_time_wait that are not TCP specific, tcp_time_wait uses
it and so will dccp_time_wait.

Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 28 insertions, 0 deletions

diff --git a/net/ipv4/inet_timewait_sock.c b/net/ipv4/inet_timewait_sock.c
index d38d160faeb7..ceb577c74237 100644
--- a/net/ipv4/inet_timewait_sock.c
+++ b/net/ipv4/inet_timewait_sock.c
@@ -81,3 +81,31 @@ void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk,
 
         write_unlock(&ehead->lock);
 }
+
+struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk, const int state)
+{
+        struct inet_timewait_sock *tw = kmem_cache_alloc(sk->sk_prot_creator->twsk_slab,
+                                                         SLAB_ATOMIC);
+        if (tw != NULL) {
+                const struct inet_sock *inet = inet_sk(sk);
+
+                /* Give us an identity. */
+                tw->tw_daddr        = inet->daddr;
+                tw->tw_rcv_saddr    = inet->rcv_saddr;
+                tw->tw_bound_dev_if = sk->sk_bound_dev_if;
+                tw->tw_num          = inet->num;
+                tw->tw_state        = TCP_TIME_WAIT;
+                tw->tw_substate     = state;
+                tw->tw_sport        = inet->sport;
+                tw->tw_dport        = inet->dport;
+                tw->tw_family       = sk->sk_family;
+                tw->tw_reuse        = sk->sk_reuse;
+                tw->tw_hashent      = sk->sk_hashent;
+                tw->tw_ipv6only     = 0;
+                tw->tw_prot         = sk->sk_prot_creator;
+                atomic_set(&tw->tw_refcnt, 1);
+                inet_twsk_dead_node_init(tw);
+        }
+
+        return tw;
+}