net: add real socket cookies
A long standing problem in netlink socket dumps is the use
of kernel socket addresses as cookies.
1) It is a security concern.
2) Sockets can be reused quite quickly, so there is
no guarantee a cookie is used once and identify
a flow.
3) request sock, establish sock, and timewait socks
for a given flow have different cookies.
Part of our effort to bring better TCP statistics requires
to switch to a different allocator.
In this patch, I chose to use a per network namespace 64bit generator,
and to use it only in the case a socket needs to be dumped to netlink.
(This might be refined later if needed)
Note that I tried to carry cookies from request sock, to establish sock,
then timewait sockets.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Eric Salo <salo@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/inet_timewait_sock.h b/include/net/inet_timewait_sock.h
index 6c56603..b7ce100 100644
--- a/include/net/inet_timewait_sock.h
+++ b/include/net/inet_timewait_sock.h
@@ -122,6 +122,7 @@
#define tw_v6_rcv_saddr __tw_common.skc_v6_rcv_saddr
#define tw_dport __tw_common.skc_dport
#define tw_num __tw_common.skc_num
+#define tw_cookie __tw_common.skc_cookie
int tw_timeout;
volatile unsigned char tw_substate;