[INET]: Generalise tcp_tw_bucket, aka TIME_WAIT sockets
This paves the way to generalise the rest of the sock ID lookup
routines and saves some bytes in TCPv4 TIME_WAIT sockets on distro
kernels (where IPv6 is always built as a module):
[root@qemu ~]# grep tw_sock /proc/slabinfo
tw_sock_TCPv6 0 0 128 31 1
tw_sock_TCP 0 0 96 41 1
[root@qemu ~]#
Now if a protocol wants to use the TIME_WAIT generic infrastructure it
only has to set the sk_prot->twsk_obj_size field with the size of its
inet_timewait_sock derived sock and proto_register will create
sk_prot->twsk_slab, for now its only for INET sockets, but we can
introduce timewait_sock later if some non INET transport protocolo
wants to use this stuff.
Next changesets will take advantage of this new infrastructure to
generalise even more TCP code.
[acme@toy net-2.6.14]$ grep built-in /tmp/before.size /tmp/after.size
/tmp/before.size: 188646 11764 5068 205478 322a6 net/ipv4/built-in.o
/tmp/after.size: 188144 11764 5068 204976 320b0 net/ipv4/built-in.o
[acme@toy net-2.6.14]$
Tested with both IPv4 & IPv6 (::1 (localhost) & ::ffff:172.20.0.1
(qemu host)).
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index b88fe05..5d295b1 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -179,6 +179,7 @@
#include <linux/skbuff.h>
#include <linux/ip.h>
#include <net/sock.h>
+#include <net/inet_timewait_sock.h>
/* This defines a selective acknowledgement block. */
struct tcp_sack_block {
@@ -387,6 +388,20 @@
return (struct tcp_sock *)sk;
}
+struct tcp_timewait_sock {
+ struct inet_timewait_sock tw_sk;
+ __u32 tw_rcv_nxt;
+ __u32 tw_snd_nxt;
+ __u32 tw_rcv_wnd;
+ __u32 tw_ts_recent;
+ long tw_ts_recent_stamp;
+};
+
+static inline struct tcp_timewait_sock *tcp_twsk(const struct sock *sk)
+{
+ return (struct tcp_timewait_sock *)sk;
+}
+
static inline void *tcp_ca(const struct tcp_sock *tp)
{
return (void *) tp->ca_priv;