[PATCH 15/16] nvmet-tcp: enable TLS handshake upcall

Sagi Grimberg sagi at grimberg.me
Wed Aug 9 03:51:14 PDT 2023



On 8/8/23 19:53, Hannes Reinecke wrote:
> Add functions to start the TLS handshake upcall when
> the TCP TSAS sectype is set to 'tls1.3' and add a config
> option NVME_TARGET_TCP_TLS.
> And move the 'state' lock to an irq-safe lock as the 'done'
> callback from the TLS handshake will be running in interrupt
> context.

Really.. that is surprising. Can you describe how exactly?

> 
> Signed-off-by: Hannes Reincke <hare at suse.de>
> ---
>   drivers/nvme/target/Kconfig    |  15 ++++
>   drivers/nvme/target/configfs.c |  27 ++++++++
>   drivers/nvme/target/nvmet.h    |   1 +
>   drivers/nvme/target/tcp.c      | 123 +++++++++++++++++++++++++++++++--
>   4 files changed, 161 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/nvme/target/Kconfig b/drivers/nvme/target/Kconfig
> index 79fc64035ee3..8a6c9cae804c 100644
> --- a/drivers/nvme/target/Kconfig
> +++ b/drivers/nvme/target/Kconfig
> @@ -84,6 +84,21 @@ config NVME_TARGET_TCP
>   
>   	  If unsure, say N.
>   
> +config NVME_TARGET_TCP_TLS
> +	bool "NVMe over Fabrics TCP target TLS encryption support"
> +	depends on NVME_TARGET_TCP
> +	select NVME_COMMON
> +	select NVME_KEYRING
> +	select NET_HANDSHAKE
> +	select KEYS
> +	help
> +	  Enables TLS encryption for the NVMe TCP target using the netlink handshake API.
> +
> +	  The TLS handshake daemon is availble at
> +	  https://github.com/oracle/ktls-utils.
> +
> +	  If unsure, say N.
> +
>   config NVME_TARGET_AUTH
>   	bool "NVMe over Fabrics In-band Authentication support"
>   	depends on NVME_TARGET
> diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
> index 3c2aeb763e22..49b407702ad5 100644
> --- a/drivers/nvme/target/configfs.c
> +++ b/drivers/nvme/target/configfs.c
> @@ -15,6 +15,7 @@
>   #ifdef CONFIG_NVME_TARGET_AUTH
>   #include <linux/nvme-auth.h>
>   #endif
> +#include <linux/nvme-keyring.h>
>   #include <crypto/hash.h>
>   #include <crypto/kpp.h>
>   
> @@ -204,6 +205,14 @@ static ssize_t nvmet_addr_treq_store(struct config_item *item,
>   
>   found:
>   	if (port->disc_addr.trtype == NVMF_TRTYPE_TCP) {
> +		if (!IS_ENABLED(CONFIG_NVME_TARGET_TCP_TLS)) {
> +			pr_err("TLS is not supported\n");
> +			return -EINVAL;
> +		}
> +		if (!port->keyring) {
> +			pr_err("TLS keyring not configured\n");
> +			return -EINVAL;
> +		}
>   		if (port->disc_addr.tsas.tcp.sectype != NVMF_TCP_SECTYPE_TLS13) {
>   			pr_warn("cannot change TREQ when TLS is not enabled\n");
>   			return -EINVAL;
> @@ -399,6 +408,15 @@ static ssize_t nvmet_addr_tsas_store(struct config_item *item,
>   	if (port->disc_addr.trtype != NVMF_TRTYPE_TCP)
>   		return -EINVAL;
>   
> +	if (!IS_ENABLED(CONFIG_NVME_TARGET_TCP_TLS)) {
> +		pr_err("TLS is not supported\n");
> +		return -EINVAL;
> +	}
> +	if (!port->keyring) {
> +		pr_err("TLS keyring not configured\n");
> +		return -EINVAL;
> +	}
> +
>   	for (i = 0; i < ARRAY_SIZE(nvmet_addr_tsas_tcp); i++) {
>   		if (sysfs_streq(page, nvmet_addr_tsas_tcp[i].name))
>   			goto found;
> @@ -1825,6 +1843,7 @@ static void nvmet_port_release(struct config_item *item)
>   	flush_workqueue(nvmet_wq);
>   	list_del(&port->global_entry);
>   
> +	key_put(port->keyring);
>   	kfree(port->ana_state);
>   	kfree(port);
>   }
> @@ -1874,6 +1893,14 @@ static struct config_group *nvmet_ports_make(struct config_group *group,
>   		return ERR_PTR(-ENOMEM);
>   	}
>   
> +	if (nvme_keyring_id()) {
> +		port->keyring = key_lookup(nvme_keyring_id());
> +		if (IS_ERR(port->keyring)) {
> +			pr_warn("NVMe keyring not available, disabling TLS\n");
> +			port->keyring = NULL;
> +		}
> +	}
> +
>   	for (i = 1; i <= NVMET_MAX_ANAGRPS; i++) {
>   		if (i == NVMET_DEFAULT_ANA_GRPID)
>   			port->ana_state[1] = NVME_ANA_OPTIMIZED;
> diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
> index 8cfd60f3b564..7f9ae53c1df5 100644
> --- a/drivers/nvme/target/nvmet.h
> +++ b/drivers/nvme/target/nvmet.h
> @@ -158,6 +158,7 @@ struct nvmet_port {
>   	struct config_group		ana_groups_group;
>   	struct nvmet_ana_group		ana_default_group;
>   	enum nvme_ana_state		*ana_state;
> +	struct key			*keyring;
>   	void				*priv;
>   	bool				enabled;
>   	int				inline_data_size;
> diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c
> index a8ceef6e5a7b..75e4cb4c2f29 100644
> --- a/drivers/nvme/target/tcp.c
> +++ b/drivers/nvme/target/tcp.c
> @@ -8,9 +8,13 @@
>   #include <linux/init.h>
>   #include <linux/slab.h>
>   #include <linux/err.h>
> +#include <linux/key.h>
>   #include <linux/nvme-tcp.h>
> +#include <linux/nvme-keyring.h>
>   #include <net/sock.h>
>   #include <net/tcp.h>
> +#include <net/tls.h>
> +#include <net/handshake.h>
>   #include <linux/inet.h>
>   #include <linux/llist.h>
>   #include <crypto/hash.h>
> @@ -66,6 +70,16 @@ device_param_cb(idle_poll_period_usecs, &set_param_ops,
>   MODULE_PARM_DESC(idle_poll_period_usecs,
>   		"nvmet tcp io_work poll till idle time period in usecs: Default 0");
>   
> +#ifdef CONFIG_NVME_TARGET_TCP_TLS
> +/*
> + * TLS handshake timeout
> + */
> +static int tls_handshake_timeout = 10;
> +module_param(tls_handshake_timeout, int, 0644);
> +MODULE_PARM_DESC(tls_handshake_timeout,
> +		 "nvme TLS handshake timeout in seconds (default 30)");

modparam description is lying...

> +#endif
> +
>   #define NVMET_TCP_RECV_BUDGET		8
>   #define NVMET_TCP_SEND_BUDGET		8
>   #define NVMET_TCP_IO_WORK_BUDGET	64
> @@ -122,6 +136,7 @@ struct nvmet_tcp_cmd {
>   
>   enum nvmet_tcp_queue_state {
>   	NVMET_TCP_Q_CONNECTING,
> +	NVMET_TCP_Q_TLS_HANDSHAKE,
>   	NVMET_TCP_Q_LIVE,
>   	NVMET_TCP_Q_DISCONNECTING,
>   };
> @@ -154,6 +169,8 @@ struct nvmet_tcp_queue {
>   	bool			data_digest;
>   	struct ahash_request	*snd_hash;
>   	struct ahash_request	*rcv_hash;
> +	key_serial_t		tls_pskid;
> +	struct delayed_work	tls_handshake_work;
>   
>   	unsigned long           poll_end;
>   
> @@ -1285,12 +1302,12 @@ static int nvmet_tcp_try_recv(struct nvmet_tcp_queue *queue,
>   
>   static void nvmet_tcp_schedule_release_queue(struct nvmet_tcp_queue *queue)
>   {
> -	spin_lock(&queue->state_lock);
> +	spin_lock_irq(&queue->state_lock);
>   	if (queue->state != NVMET_TCP_Q_DISCONNECTING) {
>   		queue->state = NVMET_TCP_Q_DISCONNECTING;
>   		queue_work(nvmet_wq, &queue->release_work);
>   	}
> -	spin_unlock(&queue->state_lock);
> +	spin_unlock_irq(&queue->state_lock);
>   }
>   
>   static inline void nvmet_tcp_arm_queue_deadline(struct nvmet_tcp_queue *queue)
> @@ -1512,8 +1529,12 @@ static void nvmet_tcp_data_ready(struct sock *sk)
>   
>   	read_lock_bh(&sk->sk_callback_lock);
>   	queue = sk->sk_user_data;
> -	if (likely(queue))
> -		queue_work_on(queue_cpu(queue), nvmet_tcp_wq, &queue->io_work);
> +	if (queue->data_ready)
> +		queue->data_ready(sk);
> +	if (likely(queue) &&
> +	    queue->state != NVMET_TCP_Q_TLS_HANDSHAKE)
> +		queue_work_on(queue_cpu(queue), nvmet_tcp_wq,
> +			      &queue->io_work);
>   	read_unlock_bh(&sk->sk_callback_lock);
>   }
>   
> @@ -1621,6 +1642,75 @@ static int nvmet_tcp_set_queue_sock(struct nvmet_tcp_queue *queue)
>   	return ret;
>   }
>   
> +#ifdef CONFIG_NVME_TARGET_TCP_TLS
> +static void nvmet_tcp_tls_handshake_done(void *data, int status,
> +					 key_serial_t peerid)
> +{
> +	struct nvmet_tcp_queue *queue = data;
> +
> +	pr_debug("queue %d: TLS handshake done, key %x, status %d\n",
> +		 queue->idx, peerid, status);
> +	spin_lock_irq(&queue->state_lock);
> +	if (queue->state != NVMET_TCP_Q_TLS_HANDSHAKE) {
> +		pr_warn("queue %d: TLS handshake already completed\n",
> +			queue->idx);
> +		spin_unlock_irq(&queue->state_lock);
> +		return;
> +	}
> +	if (!status)
> +		queue->tls_pskid = peerid;
> +	queue->state = NVMET_TCP_Q_CONNECTING;
> +	spin_unlock_irq(&queue->state_lock);
> +
> +	cancel_delayed_work_sync(&queue->tls_handshake_work);
> +	if (status) {

I think that after this call, you cannot reference anything
in queue as it may have been released. Or I'm missing something?

> +		nvmet_tcp_schedule_release_queue(queue);
> +		return;
> +	}
> +
> +	pr_debug("queue %d: resetting queue callbacks after TLS handshake\n",
> +		 queue->idx);
> +	nvmet_tcp_set_queue_sock(queue);
> +}
> +
> +static void nvmet_tcp_tls_handshake_timeout_work(struct work_struct *w)
> +{
> +	struct nvmet_tcp_queue *queue = container_of(to_delayed_work(w),
> +			struct nvmet_tcp_queue, tls_handshake_work);
> +
> +	pr_debug("queue %d: TLS handshake timeout\n", queue->idx);
> +	nvmet_tcp_tls_handshake_done((void *)queue, ETIMEDOUT, 0);
> +}
> +



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