nvme-tcp: request secure channel concatenation

Add a fabrics option 'concat' to request secure channel concatenation as
specified the NVME Base Specification v2.1, section 8.3.4.3: Secure Channel
Concatenation.
When secure channel concatenation is enabled a 'generated PSK' is inserted
into the keyring such that it's available after reset.

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

1 files changed, 47 insertions, 6 deletions

diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index b50972257e49..196d36318853 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -235,7 +235,7 @@ static inline bool nvme_tcp_tls_configured(struct nvme_ctrl *ctrl)
 	if (!IS_ENABLED(CONFIG_NVME_TCP_TLS))
 		return 0;
 
-	return ctrl->opts->tls;
+	return ctrl->opts->tls || ctrl->opts->concat;
 }
 
 static inline struct blk_mq_tags *nvme_tcp_tagset(struct nvme_tcp_queue *queue)
@@ -1987,7 +1987,7 @@ static int nvme_tcp_alloc_admin_queue(struct nvme_ctrl *ctrl)
 	if (nvme_tcp_tls_configured(ctrl)) {
 		if (ctrl->opts->tls_key)
 			pskid = key_serial(ctrl->opts->tls_key);
-		else {
+		else if (ctrl->opts->tls) {
 			pskid = nvme_tls_psk_default(ctrl->opts->keyring,
 						      ctrl->opts->host->nqn,
 						      ctrl->opts->subsysnqn);
@@ -2017,9 +2017,25 @@ static int __nvme_tcp_alloc_io_queues(struct nvme_ctrl *ctrl)
 {
 	int i, ret;
 
-	if (nvme_tcp_tls_configured(ctrl) && !ctrl->tls_pskid) {
-		dev_err(ctrl->device, "no PSK negotiated\n");
-		return -ENOKEY;
+	if (nvme_tcp_tls_configured(ctrl)) {
+		if (ctrl->opts->concat) {
+			/*
+			 * The generated PSK is stored in the
+			 * fabric options
+			 */
+			if (!ctrl->opts->tls_key) {
+				dev_err(ctrl->device, "no PSK generated\n");
+				return -ENOKEY;
+			}
+			if (ctrl->tls_pskid &&
+			    ctrl->tls_pskid != key_serial(ctrl->opts->tls_key)) {
+				dev_err(ctrl->device, "Stale PSK id %08x\n", ctrl->tls_pskid);
+				ctrl->tls_pskid = 0;
+			}
+		} else if (!ctrl->tls_pskid) {
+			dev_err(ctrl->device, "no PSK negotiated\n");
+			return -ENOKEY;
+		}
 	}
 
 	for (i = 1; i < ctrl->queue_count; i++) {
@@ -2237,6 +2253,27 @@ static void nvme_tcp_reconnect_or_remove(struct nvme_ctrl *ctrl,
 	}
 }
 
+/*
+ * The TLS key is set by secure concatenation after negotiation has been
+ * completed on the admin queue. We need to revoke the key when:
+ * - concatenation is enabled (otherwise it's a static key set by the user)
+ * and
+ * - the generated key is present in ctrl->tls_key (otherwise there's nothing
+ *   to revoke)
+ * and
+ * - a valid PSK key ID has been set in ctrl->tls_pskid (otherwise TLS
+ *   negotiation has not run).
+ *
+ * We cannot always revoke the key as nvme_tcp_alloc_admin_queue() is called
+ * twice during secure concatenation, once on a 'normal' connection to run the
+ * DH-HMAC-CHAP negotiation (which generates the key, so it _must not_ be set),
+ * and once after the negotiation (which uses the key, so it _must_ be set).
+ */
+static bool nvme_tcp_key_revoke_needed(struct nvme_ctrl *ctrl)
+{
+	return ctrl->opts->concat && ctrl->opts->tls_key && ctrl->tls_pskid;
+}
+
 static int nvme_tcp_setup_ctrl(struct nvme_ctrl *ctrl, bool new)
 {
 	struct nvmf_ctrl_options *opts = ctrl->opts;
@@ -2342,6 +2379,8 @@ static void nvme_tcp_error_recovery_work(struct work_struct *work)
 				struct nvme_tcp_ctrl, err_work);
 	struct nvme_ctrl *ctrl = &tcp_ctrl->ctrl;
 
+	if (nvme_tcp_key_revoke_needed(ctrl))
+		nvme_auth_revoke_tls_key(ctrl);
 	nvme_stop_keep_alive(ctrl);
 	flush_work(&ctrl->async_event_work);
 	nvme_tcp_teardown_io_queues(ctrl, false);
@@ -2382,6 +2421,8 @@ static void nvme_reset_ctrl_work(struct work_struct *work)
 		container_of(work, struct nvme_ctrl, reset_work);
 	int ret;
 
+	if (nvme_tcp_key_revoke_needed(ctrl))
+		nvme_auth_revoke_tls_key(ctrl);
 	nvme_stop_ctrl(ctrl);
 	nvme_tcp_teardown_ctrl(ctrl, false);
 
@@ -2877,7 +2918,7 @@ static struct nvmf_transport_ops nvme_tcp_transport = {
 			  NVMF_OPT_HDR_DIGEST | NVMF_OPT_DATA_DIGEST |
 			  NVMF_OPT_NR_WRITE_QUEUES | NVMF_OPT_NR_POLL_QUEUES |
 			  NVMF_OPT_TOS | NVMF_OPT_HOST_IFACE | NVMF_OPT_TLS |
-			  NVMF_OPT_KEYRING | NVMF_OPT_TLS_KEY,
+			  NVMF_OPT_KEYRING | NVMF_OPT_TLS_KEY | NVMF_OPT_CONCAT,
 	.create_ctrl	= nvme_tcp_create_ctrl,
 };