nvmet-tcp: enable TLS handshake upcall

TLS handshake is handled in userspace with the netlink tls handshake
protocol.

The patch adds a function to start the TLS handshake upcall for any
incoming network connections if the TCP TSAS sectype is set to 'tls1.3'.

A config option NVME_TARGET_TCP_TLS selects whether the TLS handshake
upcall should be compiled in.  The patch also adds reference counting
to struct nvmet_tcp_queue to ensure the queue is always valid when the
the TLS handshake completes.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>

diff --git a/drivers/nvme/target/Kconfig b/drivers/nvme/target/Kconfig
index 79fc64035ee30f92d88bc826f43ba00f1a3e7ef7..c56cb10053279a599ef70fc6c5b7ea633e22ac21 100644 (file)
--- 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 available 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 483569c3f622f2ee27e1225bde2c08989ada180d..b780ce049163ee86406ffaf62110bd227fd3b02a 100644 (file)
--- 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>
 
@@ -396,6 +397,17 @@ static ssize_t nvmet_addr_tsas_store(struct config_item *item,
        return -EINVAL;
 
 found:
+       if (sectype == NVMF_TCP_SECTYPE_TLS13) {
+               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;
+               }
+       }
+
        nvmet_port_init_tsas_tcp(port, sectype);
        /*
         * The TLS implementation currently does not support
@@ -1814,6 +1826,7 @@ 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);
 }
@@ -1863,6 +1876,14 @@ 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 87da62e4b74343d562513629680d60e9537c4e63..e35a03260f456eb26cb40eda4666ed2dbc6980ad 100644 (file)
--- 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 e72786b70f6851b756b0eaca7a53a89b2e8a5a29..58a4a737be77cc47f428354de8778bba46b49df4 100644 (file)
--- 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 10)");
+#endif
+
 #define NVMET_TCP_RECV_BUDGET          8
 #define NVMET_TCP_SEND_BUDGET          8
 #define NVMET_TCP_IO_WORK_BUDGET       64
@@ -122,8 +136,10 @@ 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,
+       NVMET_TCP_Q_FAILED,
 };
 
 struct nvmet_tcp_queue {
@@ -132,6 +148,7 @@ struct nvmet_tcp_queue {
        struct work_struct      io_work;
        struct nvmet_cq         nvme_cq;
        struct nvmet_sq         nvme_sq;
+       struct kref             kref;
 
        /* send state */
        struct nvmet_tcp_cmd    *cmds;
@@ -155,6 +172,10 @@ struct nvmet_tcp_queue {
        struct ahash_request    *snd_hash;
        struct ahash_request    *rcv_hash;
 
+       /* TLS state */
+       key_serial_t            tls_pskid;
+       struct delayed_work     tls_handshake_tmo_work;
+
        unsigned long           poll_end;
 
        spinlock_t              state_lock;
@@ -918,6 +939,7 @@ static int nvmet_tcp_handle_icreq(struct nvmet_tcp_queue *queue)
 free_crypto:
        if (queue->hdr_digest || queue->data_digest)
                nvmet_tcp_free_crypto(queue);
+       queue->state = NVMET_TCP_Q_FAILED;
        return ret;
 }
 
@@ -1283,12 +1305,25 @@ done:
        return ret;
 }
 
+static void nvmet_tcp_release_queue(struct kref *kref)
+{
+       struct nvmet_tcp_queue *queue =
+               container_of(kref, struct nvmet_tcp_queue, kref);
+
+       WARN_ON(queue->state != NVMET_TCP_Q_DISCONNECTING);
+       queue_work(nvmet_wq, &queue->release_work);
+}
+
 static void nvmet_tcp_schedule_release_queue(struct nvmet_tcp_queue *queue)
 {
        spin_lock(&queue->state_lock);
+       if (queue->state == NVMET_TCP_Q_TLS_HANDSHAKE) {
+               /* Socket closed during handshake */
+               tls_handshake_cancel(queue->sock->sk);
+       }
        if (queue->state != NVMET_TCP_Q_DISCONNECTING) {
                queue->state = NVMET_TCP_Q_DISCONNECTING;
-               queue_work(nvmet_wq, &queue->release_work);
+               kref_put(&queue->kref, nvmet_tcp_release_queue);
        }
        spin_unlock(&queue->state_lock);
 }
@@ -1485,6 +1520,7 @@ static void nvmet_tcp_release_queue_work(struct work_struct *w)
        mutex_unlock(&nvmet_tcp_queue_mutex);
 
        nvmet_tcp_restore_socket_callbacks(queue);
+       cancel_delayed_work_sync(&queue->tls_handshake_tmo_work);
        cancel_work_sync(&queue->io_work);
        /* stop accepting incoming data */
        queue->rcv_state = NVMET_TCP_RECV_ERR;
@@ -1512,8 +1548,13 @@ 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 (likely(queue)) {
+               if (queue->data_ready)
+                       queue->data_ready(sk);
+               if (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 +1662,87 @@ 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_bh(&queue->state_lock);
+       if (WARN_ON(queue->state != NVMET_TCP_Q_TLS_HANDSHAKE)) {
+               spin_unlock_bh(&queue->state_lock);
+               return;
+       }
+       if (!status) {
+               queue->tls_pskid = peerid;
+               queue->state = NVMET_TCP_Q_CONNECTING;
+       } else
+               queue->state = NVMET_TCP_Q_FAILED;
+       spin_unlock_bh(&queue->state_lock);
+
+       cancel_delayed_work_sync(&queue->tls_handshake_tmo_work);
+       if (status)
+               nvmet_tcp_schedule_release_queue(queue);
+       else
+               nvmet_tcp_set_queue_sock(queue);
+       kref_put(&queue->kref, nvmet_tcp_release_queue);
+}
+
+static void nvmet_tcp_tls_handshake_timeout(struct work_struct *w)
+{
+       struct nvmet_tcp_queue *queue = container_of(to_delayed_work(w),
+                       struct nvmet_tcp_queue, tls_handshake_tmo_work);
+
+       pr_warn("queue %d: TLS handshake timeout\n", queue->idx);
+       /*
+        * If tls_handshake_cancel() fails we've lost the race with
+        * nvmet_tcp_tls_handshake_done() */
+       if (!tls_handshake_cancel(queue->sock->sk))
+               return;
+       spin_lock_bh(&queue->state_lock);
+       if (WARN_ON(queue->state != NVMET_TCP_Q_TLS_HANDSHAKE)) {
+               spin_unlock_bh(&queue->state_lock);
+               return;
+       }
+       queue->state = NVMET_TCP_Q_FAILED;
+       spin_unlock_bh(&queue->state_lock);
+       nvmet_tcp_schedule_release_queue(queue);
+       kref_put(&queue->kref, nvmet_tcp_release_queue);
+}
+
+static int nvmet_tcp_tls_handshake(struct nvmet_tcp_queue *queue)
+{
+       int ret = -EOPNOTSUPP;
+       struct tls_handshake_args args;
+
+       if (queue->state != NVMET_TCP_Q_TLS_HANDSHAKE) {
+               pr_warn("cannot start TLS in state %d\n", queue->state);
+               return -EINVAL;
+       }
+
+       kref_get(&queue->kref);
+       pr_debug("queue %d: TLS ServerHello\n", queue->idx);
+       memset(&args, 0, sizeof(args));
+       args.ta_sock = queue->sock;
+       args.ta_done = nvmet_tcp_tls_handshake_done;
+       args.ta_data = queue;
+       args.ta_keyring = key_serial(queue->port->nport->keyring);
+       args.ta_timeout_ms = tls_handshake_timeout * 1000;
+
+       ret = tls_server_hello_psk(&args, GFP_KERNEL);
+       if (ret) {
+               kref_put(&queue->kref, nvmet_tcp_release_queue);
+               pr_err("failed to start TLS, err=%d\n", ret);
+       } else {
+               queue_delayed_work(nvmet_wq, &queue->tls_handshake_tmo_work,
+                                  tls_handshake_timeout * HZ);
+       }
+       return ret;
+}
+#endif
+
 static void nvmet_tcp_alloc_queue(struct nvmet_tcp_port *port,
                struct socket *newsock)
 {
@@ -1636,11 +1758,16 @@ static void nvmet_tcp_alloc_queue(struct nvmet_tcp_port *port,
 
        INIT_WORK(&queue->release_work, nvmet_tcp_release_queue_work);
        INIT_WORK(&queue->io_work, nvmet_tcp_io_work);
+       kref_init(&queue->kref);
        queue->sock = newsock;
        queue->port = port;
        queue->nr_cmds = 0;
        spin_lock_init(&queue->state_lock);
-       queue->state = NVMET_TCP_Q_CONNECTING;
+       if (queue->port->nport->disc_addr.tsas.tcp.sectype ==
+           NVMF_TCP_SECTYPE_TLS13)
+               queue->state = NVMET_TCP_Q_TLS_HANDSHAKE;
+       else
+               queue->state = NVMET_TCP_Q_CONNECTING;
        INIT_LIST_HEAD(&queue->free_list);
        init_llist_head(&queue->resp_list);
        INIT_LIST_HEAD(&queue->resp_send_list);
@@ -1671,6 +1798,25 @@ static void nvmet_tcp_alloc_queue(struct nvmet_tcp_port *port,
        list_add_tail(&queue->queue_list, &nvmet_tcp_queue_list);
        mutex_unlock(&nvmet_tcp_queue_mutex);
 
+#ifdef CONFIG_NVME_TARGET_TCP_TLS
+       INIT_DELAYED_WORK(&queue->tls_handshake_tmo_work,
+                         nvmet_tcp_tls_handshake_timeout);
+       if (queue->state == NVMET_TCP_Q_TLS_HANDSHAKE) {
+               struct sock *sk = queue->sock->sk;
+
+               /* Restore the default callbacks before starting upcall */
+               read_lock_bh(&sk->sk_callback_lock);
+               sk->sk_user_data = NULL;
+               sk->sk_data_ready = port->data_ready;
+               read_unlock_bh(&sk->sk_callback_lock);
+               if (!nvmet_tcp_tls_handshake(queue))
+                       return;
+
+               /* TLS handshake failed, terminate the connection */
+               goto out_destroy_sq;
+       }
+#endif
+
        ret = nvmet_tcp_set_queue_sock(queue);
        if (ret)
                goto out_destroy_sq;