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_sock.h b/include/net/inet_sock.h
index eb16c7b..e565afd 100644
--- a/include/net/inet_sock.h
+++ b/include/net/inet_sock.h
@@ -77,6 +77,8 @@
#define ir_v6_rmt_addr req.__req_common.skc_v6_daddr
#define ir_v6_loc_addr req.__req_common.skc_v6_rcv_saddr
#define ir_iif req.__req_common.skc_bound_dev_if
+#define ir_cookie req.__req_common.skc_cookie
+#define ireq_net req.__req_common.skc_net
kmemcheck_bitfield_begin(flags);
u16 snd_wscale : 4,
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;
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index 2cb9acb..e086f40 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -56,6 +56,8 @@
#endif
spinlock_t rules_mod_lock;
+ atomic64_t cookie_gen;
+
struct list_head list; /* list of network namespaces */
struct list_head cleanup_list; /* namespaces on death row */
struct list_head exit_list; /* Use only net_mutex */
diff --git a/include/net/sock.h b/include/net/sock.h
index 250822c..d996c63 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -199,6 +199,8 @@
struct in6_addr skc_v6_rcv_saddr;
#endif
+ atomic64_t skc_cookie;
+
/*
* fields between dontcopy_begin/dontcopy_end
* are not copied in sock_copy()
@@ -329,6 +331,7 @@
#define sk_net __sk_common.skc_net
#define sk_v6_daddr __sk_common.skc_v6_daddr
#define sk_v6_rcv_saddr __sk_common.skc_v6_rcv_saddr
+#define sk_cookie __sk_common.skc_cookie
socket_lock_t sk_lock;
struct sk_buff_head sk_receive_queue;