Re: [PATCH v15 net-next 01/12] tls: support for Inline tls record

[Boris Pismenny <borisp@mellanox.com>]

On 3/31/2018 7:11 PM, Atul Gupta wrote:
> 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>
> Reviewed-by: Steve Wise <swise@opengridcomputing.com>
> ---
>   include/net/tls.h  |  32 ++++++++++++++-
>   net/tls/tls_main.c | 114 +++++++++++++++++++++++++++++++++++++++++++++++++++--
>   2 files changed, 142 insertions(+), 4 deletions(-)
> 
> diff --git a/include/net/tls.h b/include/net/tls.h
> index 437a746..3da8e13 100644
> --- a/include/net/tls.h
> +++ b/include/net/tls.h
> @@ -56,6 +56,32 @@
>   #define TLS_RECORD_TYPE_DATA		0x17
>   
>   #define TLS_AAD_SPACE_SIZE		13
> +#define TLS_DEVICE_NAME_MAX		32
> +
> +/*
> + * 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;
> @@ -114,7 +140,7 @@ struct tls_context {
>   
>   	void *priv_ctx;
>   
> -	u8 conf:2;
> +	u8 conf:3;
>   
>   	struct cipher_context tx;
>   	struct cipher_context rx;
> @@ -135,6 +161,8 @@ 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);
> @@ -283,5 +311,7 @@ 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 6f5c114..0d37997 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>
>   
> @@ -56,11 +57,14 @@ enum {
>   	TLS_SW_TX,
>   	TLS_SW_RX,
>   	TLS_SW_RXTX,
> +	TLS_HW_RECORD,
>   	TLS_NUM_CONFIG,
>   };
>   
>   static struct proto *saved_tcpv6_prot;
>   static DEFINE_MUTEX(tcpv6_prot_mutex);
> +static LIST_HEAD(device_list);
> +static DEFINE_MUTEX(device_mutex);
>   static struct proto tls_prots[TLS_NUM_PROTS][TLS_NUM_CONFIG];
>   static struct proto_ops tls_sw_proto_ops;
>   
> @@ -241,8 +245,12 @@ static void tls_sk_proto_close(struct sock *sk, long timeout)
>   	lock_sock(sk);
>   	sk_proto_close = ctx->sk_proto_close;
>   
> +	if (ctx->conf == TLS_HW_RECORD)
> +		goto skip_tx_cleanup;
> +
>   	if (ctx->conf == TLS_BASE) {
>   		kfree(ctx);
> +		ctx = NULL;
>   		goto skip_tx_cleanup;
>   	}
>   
> @@ -276,6 +284,11 @@ static void tls_sk_proto_close(struct sock *sk, long timeout)
>   skip_tx_cleanup:
>   	release_sock(sk);
>   	sk_proto_close(sk, timeout);
> +	/* free ctx for TLS_HW_RECORD, used by tcp_set_state
> +	 * for sk->sk_prot->unhash [tls_hw_unhash]
> +	 */
> +	if (ctx && ctx->conf == TLS_HW_RECORD)
> +		kfree(ctx);
>   }
>   
>   static int do_tls_getsockopt_tx(struct sock *sk, char __user *optval,
> @@ -493,6 +506,79 @@ static int tls_setsockopt(struct sock *sk, int level, int optname,
>   	return do_tls_setsockopt(sk, optname, optval, optlen);
>   }
>   
> +static struct tls_context *create_ctx(struct sock *sk)
> +{
> +	struct inet_connection_sock *icsk = inet_csk(sk);
> +	struct tls_context *ctx;
> +
> +	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)) {

What happens when features change? or when the device goes down?

> +			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->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 void build_protos(struct proto *prot, struct proto *base)
>   {
>   	prot[TLS_BASE] = *base;
> @@ -511,15 +597,22 @@ static void build_protos(struct proto *prot, struct proto *base)
>   	prot[TLS_SW_RXTX] = prot[TLS_SW_TX];
>   	prot[TLS_SW_RXTX].recvmsg	= tls_sw_recvmsg;
>   	prot[TLS_SW_RXTX].close		= tls_sk_proto_close;
> +
> +	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;
>   }
>   
>   static int tls_init(struct sock *sk)
>   {
>   	int ip_ver = sk->sk_family == AF_INET6 ? TLSV6 : TLSV4;
> -	struct inet_connection_sock *icsk = inet_csk(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
> @@ -530,12 +623,11 @@ 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;
> @@ -557,6 +649,22 @@ static int tls_init(struct sock *sk)
>   	return rc;
>   }
>   
> +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 struct tcp_ulp_ops tcp_tls_ulp_ops __read_mostly = {
>   	.name			= "tls",
>   	.uid			= TCP_ULP_TLS,
>