[PATCH v11 crypto 01/12] tls: support for Inline tls record

[Atul Gupta <atul.gupta@chelsio.com>]

Facility to register Inline TLS drivers to net/tls. Setup
TLS_HW_RECORD prot to listen on offload device.

Cases handled
- Inline TLS device exists, setup prot for TLS_HW_RECORD
- Atleast one Inline TLS exists, sets TLS_HW_RECORD.
- If non-inline device establish connection, move to TLS_SW_TX

Signed-off-by: Atul Gupta <atul.gupta@chelsio.com>
---
 include/net/tls.h  |  39 ++++++++++++++++++
 net/tls/tls_main.c | 116 ++++++++++++++++++++++++++++++++++++++++++++++++-----
 2 files changed, 145 insertions(+), 10 deletions(-)

diff --git a/include/net/tls.h b/include/net/tls.h
index 4913430..c19967c 100644
--- a/include/net/tls.h
+++ b/include/net/tls.h
@@ -55,6 +55,41 @@
 #define TLS_RECORD_TYPE_DATA		0x17
 
 #define TLS_AAD_SPACE_SIZE		13
+#define TLS_DEVICE_NAME_MAX		32
+
+enum {
+	TLS_BASE_TX,
+	TLS_SW_TX,
+	TLS_HW_RECORD, /* TLS record processed Inline */
+	TLS_NUM_CONFIG,
+};
+
+extern struct proto tls_prots[TLS_NUM_CONFIG];
+
+/*
+ * This structure defines the routines for Inline TLS driver.
+ * The following routines are optional and filled with a
+ * null pointer if not defined.
+ *
+ * @name: Its the name of registered Inline tls device
+ * @dev_list: Inline tls device list
+ * int (*feature)(struct tls_device *device);
+ *     Called to return Inline TLS driver capability
+ *
+ * int (*hash)(struct tls_device *device, struct sock *sk);
+ *     This function sets Inline driver for listen and program
+ *     device specific functioanlity as required
+ *
+ * void (*unhash)(struct tls_device *device, struct sock *sk);
+ *     This function cleans listen state set by Inline TLS driver
+ */
+struct tls_device {
+	char name[TLS_DEVICE_NAME_MAX];
+	struct list_head dev_list;
+	int  (*feature)(struct tls_device *device);
+	int  (*hash)(struct tls_device *device, struct sock *sk);
+	void (*unhash)(struct tls_device *device, struct sock *sk);
+};
 
 struct tls_sw_context {
 	struct crypto_aead *aead_send;
@@ -115,6 +150,8 @@ struct tls_context {
 	int  (*getsockopt)(struct sock *sk, int level,
 			   int optname, char __user *optval,
 			   int __user *optlen);
+	int  (*hash)(struct sock *sk);
+	void (*unhash)(struct sock *sk);
 };
 
 int wait_on_pending_writer(struct sock *sk, long *timeo);
@@ -256,5 +293,7 @@ static inline struct tls_offload_context *tls_offload_ctx(
 
 int tls_proccess_cmsg(struct sock *sk, struct msghdr *msg,
 		      unsigned char *record_type);
+void tls_register_device(struct tls_device *device);
+void tls_unregister_device(struct tls_device *device);
 
 #endif /* _TLS_OFFLOAD_H */
diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c
index b0d5fce..4efb338 100644
--- a/net/tls/tls_main.c
+++ b/net/tls/tls_main.c
@@ -38,6 +38,7 @@
 #include <linux/highmem.h>
 #include <linux/netdevice.h>
 #include <linux/sched/signal.h>
+#include <linux/inetdevice.h>
 
 #include <net/tls.h>
 
@@ -45,13 +46,9 @@
 MODULE_DESCRIPTION("Transport Layer Security Support");
 MODULE_LICENSE("Dual BSD/GPL");
 
-enum {
-	TLS_BASE_TX,
-	TLS_SW_TX,
-	TLS_NUM_CONFIG,
-};
-
-static struct proto tls_prots[TLS_NUM_CONFIG];
+static LIST_HEAD(device_list);
+static DEFINE_MUTEX(device_mutex);
+struct proto tls_prots[TLS_NUM_CONFIG];
 
 static inline void update_sk_prot(struct sock *sk, struct tls_context *ctx)
 {
@@ -258,6 +255,8 @@ static void tls_sk_proto_close(struct sock *sk, long timeout)
 skip_tx_cleanup:
 	release_sock(sk);
 	sk_proto_close(sk, timeout);
+	if (ctx->tx_conf == TLS_HW_RECORD)
+		kfree(ctx);
 }
 
 static int do_tls_getsockopt_tx(struct sock *sk, char __user *optval,
@@ -450,12 +449,88 @@ static int tls_setsockopt(struct sock *sk, int level, int optname,
 	return do_tls_setsockopt(sk, optname, optval, optlen);
 }
 
-static int tls_init(struct sock *sk)
+struct tls_context *create_ctx(struct sock *sk)
 {
 	struct inet_connection_sock *icsk = inet_csk(sk);
 	struct tls_context *ctx;
+
+	/* allocate tls context */
+	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return NULL;
+
+	icsk->icsk_ulp_data = ctx;
+	return ctx;
+}
+
+static int tls_hw_prot(struct sock *sk)
+{
+	struct tls_context *ctx;
+	struct tls_device *dev;
+	int rc = 0;
+
+	mutex_lock(&device_mutex);
+	list_for_each_entry(dev, &device_list, dev_list) {
+		if (dev->feature && dev->feature(dev)) {
+			ctx = create_ctx(sk);
+			if (!ctx)
+				goto out;
+
+			ctx->hash = sk->sk_prot->hash;
+			ctx->unhash = sk->sk_prot->unhash;
+			ctx->sk_proto_close = sk->sk_prot->close;
+			ctx->tx_conf = TLS_HW_RECORD;
+			update_sk_prot(sk, ctx);
+			rc = 1;
+			break;
+		}
+	}
+out:
+	mutex_unlock(&device_mutex);
+	return rc;
+}
+
+static void tls_hw_unhash(struct sock *sk)
+{
+	struct tls_context *ctx = tls_get_ctx(sk);
+	struct tls_device *dev;
+
+	mutex_lock(&device_mutex);
+	list_for_each_entry(dev, &device_list, dev_list) {
+		if (dev->unhash)
+			dev->unhash(dev, sk);
+	}
+	mutex_unlock(&device_mutex);
+	ctx->unhash(sk);
+}
+
+static int tls_hw_hash(struct sock *sk)
+{
+	struct tls_context *ctx = tls_get_ctx(sk);
+	struct tls_device *dev;
+	int err;
+
+	err = ctx->hash(sk);
+	mutex_lock(&device_mutex);
+	list_for_each_entry(dev, &device_list, dev_list) {
+		if (dev->hash)
+			err |= dev->hash(dev, sk);
+	}
+	mutex_unlock(&device_mutex);
+
+	if (err)
+		tls_hw_unhash(sk);
+	return err;
+}
+
+static int tls_init(struct sock *sk)
+{
+	struct tls_context *ctx;
 	int rc = 0;
 
+	if (tls_hw_prot(sk))
+		goto out;
+
 	/* The TLS ulp is currently supported only for TCP sockets
 	 * in ESTABLISHED state.
 	 * Supporting sockets in LISTEN state will require us
@@ -466,12 +541,11 @@ static int tls_init(struct sock *sk)
 		return -ENOTSUPP;
 
 	/* allocate tls context */
-	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+	ctx = create_ctx(sk);
 	if (!ctx) {
 		rc = -ENOMEM;
 		goto out;
 	}
-	icsk->icsk_ulp_data = ctx;
 	ctx->setsockopt = sk->sk_prot->setsockopt;
 	ctx->getsockopt = sk->sk_prot->getsockopt;
 	ctx->sk_proto_close = sk->sk_prot->close;
@@ -500,7 +574,28 @@ static void build_protos(struct proto *prot, struct proto *base)
 	prot[TLS_SW_TX] = prot[TLS_BASE_TX];
 	prot[TLS_SW_TX].sendmsg		= tls_sw_sendmsg;
 	prot[TLS_SW_TX].sendpage	= tls_sw_sendpage;
+
+	prot[TLS_HW_RECORD] = *base;
+	prot[TLS_HW_RECORD].hash	= tls_hw_hash;
+	prot[TLS_HW_RECORD].unhash	= tls_hw_unhash;
+	prot[TLS_HW_RECORD].close	= tls_sk_proto_close;
+}
+
+void tls_register_device(struct tls_device *device)
+{
+	mutex_lock(&device_mutex);
+	list_add_tail(&device->dev_list, &device_list);
+	mutex_unlock(&device_mutex);
+}
+EXPORT_SYMBOL(tls_register_device);
+
+void tls_unregister_device(struct tls_device *device)
+{
+	mutex_lock(&device_mutex);
+	list_del(&device->dev_list);
+	mutex_unlock(&device_mutex);
 }
+EXPORT_SYMBOL(tls_unregister_device);
 
 static int __init tls_register(void)
 {
@@ -510,6 +605,7 @@ static int __init tls_register(void)
 
 	return 0;
 }
+EXPORT_SYMBOL(tls_prots);
 
 static void __exit tls_unregister(void)
 {
-- 
1.8.3.1