Merge branch 'net-tls-add-socket-diag'

Davide Caratti says:

====================
net: tls: add socket diag

The current kernel does not provide any diagnostic tool, except
getsockopt(TCP_ULP), to know more about TCP sockets that have an upper
layer protocol (ULP) on top of them. This series extends the set of
information exported by INET_DIAG_INFO, to include data that are
specific to the ULP (and that might be meaningful for debug/testing
purposes).

patch 1/3 ensures that the control plane reads/updates ULP specific data
using RCU.

patch 2/3 extends INET_DIAG_INFO and allows knowing the ULP name for
each TCP socket that has done setsockopt(TCP_ULP) successfully.

patch 3/3 extends kTLS to let programs like 'ss' know the protocol
version and the cipher in use.

Changes since v2:
- remove unneeded #ifdef and fix reverse christmas tree in
  tls_get_info(), thanks to Jakub Kicinski

Changes since v1:
- don't worry about grace period when accessing ulp_ops, thanks to
  Jakub Kicinski and Eric Dumazet
- use rcu_dereference() to access ULP data in tls get_info(), and
  test against NULL value, thanks to Jakub Kicinski
- move RCU protected section inside tls get_info(), thanks to Jakub
  Kicinski

Changes since RFC:
- some coding style fixes, thanks to Jakub Kicinski
- add X_UNSPEC as lowest value of uAPI enums, thanks to Jakub Kicinski
- fix assignment of struct nlattr *start, thanks to Jakub Kicinski
- let tls dump RXCONF and TXCONF, suggested by Jakub Kicinski
- don't dump anything if TLS version or cipher are 0 (but still return a
  constant size in get_aux_size()), thanks to Boris Pismenny
- constify first argument of get_info() and get_size()
- use RCU to access access ulp_ops, like it's done for ca_ops
- add patch 1/3, from Jakub Kicinski
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 28 insertions, 3 deletions

diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h
index c57d53e7e02c..895546058a20 100644
--- a/include/net/inet_connection_sock.h
+++ b/include/net/inet_connection_sock.h
@@ -97,7 +97,7 @@ struct inet_connection_sock {
 	const struct tcp_congestion_ops *icsk_ca_ops;
 	const struct inet_connection_sock_af_ops *icsk_af_ops;
 	const struct tcp_ulp_ops  *icsk_ulp_ops;
-	void			  *icsk_ulp_data;
+	void __rcu		  *icsk_ulp_data;
 	void (*icsk_clean_acked)(struct sock *sk, u32 acked_seq);
 	struct hlist_node         icsk_listen_portaddr_node;
 	unsigned int		  (*icsk_sync_mss)(struct sock *sk, u32 pmtu);
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 77fe87f7a992..c9a3f9688223 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -2122,6 +2122,9 @@ struct tcp_ulp_ops {
 	void (*update)(struct sock *sk, struct proto *p);
 	/* cleanup ulp */
 	void (*release)(struct sock *sk);
+	/* diagnostic */
+	int (*get_info)(const struct sock *sk, struct sk_buff *skb);
+	size_t (*get_info_size)(const struct sock *sk);
 
 	char		name[TCP_ULP_NAME_MAX];
 	struct module	*owner;
diff --git a/include/net/tls.h b/include/net/tls.h
index 41b2d41bb1b8..ec3c3ed2c6c3 100644
--- a/include/net/tls.h
+++ b/include/net/tls.h
@@ -41,6 +41,7 @@
 #include <linux/tcp.h>
 #include <linux/skmsg.h>
 #include <linux/netdevice.h>
+#include <linux/rcupdate.h>
 
 #include <net/tcp.h>
 #include <net/strparser.h>
@@ -290,6 +291,7 @@ struct tls_context {
 
 	struct list_head list;
 	refcount_t refcount;
+	struct rcu_head rcu;
 };
 
 enum tls_offload_ctx_dir {
@@ -348,7 +350,7 @@ struct tls_offload_context_rx {
 #define TLS_OFFLOAD_CONTEXT_SIZE_RX					\
 	(sizeof(struct tls_offload_context_rx) + TLS_DRIVER_STATE_SIZE_RX)
 
-void tls_ctx_free(struct tls_context *ctx);
+void tls_ctx_free(struct sock *sk, struct tls_context *ctx);
 int wait_on_pending_writer(struct sock *sk, long *timeo);
 int tls_sk_query(struct sock *sk, int optname, char __user *optval,
 		int __user *optlen);
@@ -429,6 +431,23 @@ static inline bool is_tx_ready(struct tls_sw_context_tx *ctx)
 	return READ_ONCE(rec->tx_ready);
 }
 
+static inline u16 tls_user_config(struct tls_context *ctx, bool tx)
+{
+	u16 config = tx ? ctx->tx_conf : ctx->rx_conf;
+
+	switch (config) {
+	case TLS_BASE:
+		return TLS_CONF_BASE;
+	case TLS_SW:
+		return TLS_CONF_SW;
+	case TLS_HW:
+		return TLS_CONF_HW;
+	case TLS_HW_RECORD:
+		return TLS_CONF_HW_RECORD;
+	}
+	return 0;
+}
+
 struct sk_buff *
 tls_validate_xmit_skb(struct sock *sk, struct net_device *dev,
 		      struct sk_buff *skb);
@@ -467,7 +486,10 @@ static inline struct tls_context *tls_get_ctx(const struct sock *sk)
 {
 	struct inet_connection_sock *icsk = inet_csk(sk);
 
-	return icsk->icsk_ulp_data;
+	/* Use RCU on icsk_ulp_data only for sock diag code,
+	 * TLS data path doesn't need rcu_dereference().
+	 */
+	return (__force void *)icsk->icsk_ulp_data;
 }
 
 static inline void tls_advance_record_sn(struct sock *sk,