[PATCH 11/17] nvme-tcp: enable TLS handshake upcall
Hannes Reinecke
hare at suse.de
Tue May 9 07:22:13 PDT 2023
On 5/9/23 11:48, Max Gurtovoy wrote:
>
>
> On 19/04/2023 9:57, Hannes Reinecke wrote:
>> Add a fabrics option 'tls' and start the TLS handshake upcall
>> with the default PSK. When TLS is started the PSK key serial
>> number is displayed in the sysfs attribute 'tls_key'
>
> Can you please explain the flow for the TLS handshake in the cover letter ?
Sure. Will do so in the next round.
>>
>> Signed-off-by: Hannes Reinecke <hare at suse.de>
>> ---
>> drivers/nvme/host/Kconfig | 14 ++++
>> drivers/nvme/host/core.c | 23 ++++++-
>> drivers/nvme/host/fabrics.c | 12 ++++
>> drivers/nvme/host/fabrics.h | 3 +
>> drivers/nvme/host/nvme.h | 1 +
>> drivers/nvme/host/tcp.c | 129 ++++++++++++++++++++++++++++++++++--
>> 6 files changed, 174 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/nvme/host/Kconfig b/drivers/nvme/host/Kconfig
>> index 2f6a7f8c94e8..96a74041bb0a 100644
>> --- a/drivers/nvme/host/Kconfig
>> +++ b/drivers/nvme/host/Kconfig
>> @@ -92,6 +92,20 @@ config NVME_TCP
>> If unsure, say N.
>> +config NVME_TCP_TLS
>> + bool "NVMe over Fabrics TCP TLS encryption support"
>> + depends on NVME_TCP
>> + select NVME_COMMON
>> + select NVME_KEYRING
>> + select NET_HANDSHAKE
>> + help
>> + Enables TLS encryption for NVMe TCP using the netlink handshake
>> API.
>> +
>> + The TLS handshake daemon is availble at
>> + https://github.com/oracle/ktls-utils.
>> +
>> + If unsure, say N.
>> +
>> config NVME_AUTH
>> bool "NVM Express over Fabrics In-Band Authentication"
>> depends on NVME_CORE
>> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
>> index 79aa215aec76..937013127c91 100644
>> --- a/drivers/nvme/host/core.c
>> +++ b/drivers/nvme/host/core.c
>> @@ -3889,6 +3889,19 @@ static DEVICE_ATTR(dhchap_ctrl_secret, S_IRUGO
>> | S_IWUSR,
>> nvme_ctrl_dhchap_ctrl_secret_show,
>> nvme_ctrl_dhchap_ctrl_secret_store);
>> #endif
>> +#ifdef CONFIG_NVME_TCP_TLS
>> +static ssize_t tls_key_show(struct device *dev,
>> + struct device_attribute *attr, char *buf)
>> +{
>> + struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
>> +
>> + if (!ctrl->tls_key)
>> + return 0;
>> + return sysfs_emit(buf, "%08x", key_serial(ctrl->tls_key));
>> +}
>> +static DEVICE_ATTR_RO(tls_key);
>> +#endif
>> +
>> static struct attribute *nvme_dev_attrs[] = {
>> &dev_attr_reset_controller.attr,
>> &dev_attr_rescan_controller.attr,
>> @@ -3915,6 +3928,9 @@ static struct attribute *nvme_dev_attrs[] = {
>> #ifdef CONFIG_NVME_AUTH
>> &dev_attr_dhchap_secret.attr,
>> &dev_attr_dhchap_ctrl_secret.attr,
>> +#endif
>> +#ifdef CONFIG_NVME_TCP_TLS
>> + &dev_attr_tls_key.attr,
>> #endif
>> NULL
>> };
>> @@ -3945,7 +3961,10 @@ static umode_t
>> nvme_dev_attrs_are_visible(struct kobject *kobj,
>> if (a == &dev_attr_dhchap_ctrl_secret.attr && !ctrl->opts)
>> return 0;
>> #endif
>> -
>> +#ifdef CONFIG_NVME_TCP_TLS
>> + if (a == &dev_attr_tls_key.attr && !ctrl->opts)
>> + return 0;
>> +#endif
>> return a->mode;
>> }
>> @@ -5080,7 +5099,7 @@ static void nvme_free_ctrl(struct device *dev)
>> if (!subsys || ctrl->instance != subsys->instance)
>> ida_free(&nvme_instance_ida, ctrl->instance);
>> -
>> + key_put(ctrl->tls_key);
>> nvme_free_cels(ctrl);
>> nvme_mpath_uninit(ctrl);
>> nvme_auth_stop(ctrl);
>> diff --git a/drivers/nvme/host/fabrics.c b/drivers/nvme/host/fabrics.c
>> index bbaa04a0c502..2aa8fb991455 100644
>> --- a/drivers/nvme/host/fabrics.c
>> +++ b/drivers/nvme/host/fabrics.c
>> @@ -609,6 +609,9 @@ static const match_table_t opt_tokens = {
>> { NVMF_OPT_DISCOVERY, "discovery" },
>> { NVMF_OPT_DHCHAP_SECRET, "dhchap_secret=%s" },
>> { NVMF_OPT_DHCHAP_CTRL_SECRET, "dhchap_ctrl_secret=%s" },
>> +#ifdef CONFIG_NVME_TCP_TLS
>
> This ifdef is redundant IMO.
> We have to many of those already in the code and we should reduce to be
> able to keep the code maintainable.
>
We have been going back and forth on this, and the consensus was to
_have_ a compilation flag here. This allows the userland utility
nvme-cli to determine whether tls support is available on any given kernel.
>> + { NVMF_OPT_TLS, "tls" },
>> +#endif
>> { NVMF_OPT_ERR, NULL }
>> };
>> @@ -632,6 +635,7 @@ static int nvmf_parse_options(struct
>> nvmf_ctrl_options *opts,
>> opts->hdr_digest = false;
>> opts->data_digest = false;
>> opts->tos = -1; /* < 0 == use transport default */
>> + opts->tls = false;
>> options = o = kstrdup(buf, GFP_KERNEL);
>> if (!options)
>> @@ -918,6 +922,14 @@ static int nvmf_parse_options(struct
>> nvmf_ctrl_options *opts,
>> kfree(opts->dhchap_ctrl_secret);
>> opts->dhchap_ctrl_secret = p;
>> break;
>> + case NVMF_OPT_TLS:
>> + if (!IS_ENABLED(CONFIG_NVME_TCP_TLS)) {
>> + pr_err("TLS is not supported\n");
>> + ret = -EINVAL;
>> + goto out;
>> + }
>> + opts->tls = true;
>> + break;
>> default:
>> pr_warn("unknown parameter or missing value '%s' in ctrl
>> creation request\n",
>> p);
>> diff --git a/drivers/nvme/host/fabrics.h b/drivers/nvme/host/fabrics.h
>> index dcac3df8a5f7..5db36e250e7a 100644
>> --- a/drivers/nvme/host/fabrics.h
>> +++ b/drivers/nvme/host/fabrics.h
>> @@ -70,6 +70,7 @@ enum {
>> NVMF_OPT_DISCOVERY = 1 << 22,
>> NVMF_OPT_DHCHAP_SECRET = 1 << 23,
>> NVMF_OPT_DHCHAP_CTRL_SECRET = 1 << 24,
>> + NVMF_OPT_TLS = 1 << 25,
>> };
>> /**
>> @@ -102,6 +103,7 @@ enum {
>> * @dhchap_secret: DH-HMAC-CHAP secret
>> * @dhchap_ctrl_secret: DH-HMAC-CHAP controller secret for
>> bi-directional
>> * authentication
>> + * @tls: Start TLS encrypted connections (TCP)
>> * @disable_sqflow: disable controller sq flow control
>> * @hdr_digest: generate/verify header digest (TCP)
>> * @data_digest: generate/verify data digest (TCP)
>> @@ -128,6 +130,7 @@ struct nvmf_ctrl_options {
>> int max_reconnects;
>> char *dhchap_secret;
>> char *dhchap_ctrl_secret;
>> + bool tls;
>> bool disable_sqflow;
>> bool hdr_digest;
>> bool data_digest;
>> diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
>> index bf46f122e9e1..fbcc0ccf2ef2 100644
>> --- a/drivers/nvme/host/nvme.h
>> +++ b/drivers/nvme/host/nvme.h
>> @@ -347,6 +347,7 @@ struct nvme_ctrl {
>> struct nvme_dhchap_key *ctrl_key;
>> u16 transaction;
>> #endif
>> + struct key *tls_key;
>> /* Power saving configuration */
>> u64 ps_max_latency_us;
>> diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
>> index 9deba481ae6a..d25695cf4e03 100644
>> --- a/drivers/nvme/host/tcp.c
>> +++ b/drivers/nvme/host/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/blk-mq.h>
>> #include <crypto/hash.h>
>> #include <net/busy_poll.h>
>> @@ -31,6 +35,16 @@ static int so_priority;
>> module_param(so_priority, int, 0644);
>> MODULE_PARM_DESC(so_priority, "nvme tcp socket optimize priority");
>> +#ifdef CONFIG_NVME_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
>
> Module param under ifdef also sounds redundant.
>> +
>> #ifdef CONFIG_DEBUG_LOCK_ALLOC
>> /* lockdep can detect a circular dependency of the form
>> * sk_lock -> mmap_lock (page fault) -> fs locks -> sk_lock
>> @@ -146,7 +160,10 @@ struct nvme_tcp_queue {
>> struct ahash_request *snd_hash;
>> __le32 exp_ddgst;
>> __le32 recv_ddgst;
>> -
>> +#ifdef CONFIG_NVME_TCP_TLS
>> + struct completion tls_complete;
>> + int tls_err;
>> +#endif
>> struct page_frag_cache pf_cache;
>> void (*state_change)(struct sock *);
>> @@ -1502,7 +1519,79 @@ static void nvme_tcp_set_queue_io_cpu(struct
>> nvme_tcp_queue *queue)
>> queue->io_cpu = cpumask_next_wrap(n - 1, cpu_online_mask, -1,
>> false);
>> }
>> -static int nvme_tcp_alloc_queue(struct nvme_ctrl *nctrl, int qid)
>> +#ifdef CONFIG_NVME_TCP_TLS
>> +static void nvme_tcp_tls_done(void *data, int status, key_serial_t
>> pskid)
>> +{
>> + struct nvme_tcp_queue *queue = data;
>> + struct nvme_tcp_ctrl *ctrl = queue->ctrl;
>> + int qid = nvme_tcp_queue_id(queue);
>> + struct key *tls_key;
>> +
>> + dev_dbg(ctrl->ctrl.device, "queue %d: TLS handshake done, key %x,
>> status %d\n",
>> + qid, pskid, status);
>> +
>> + if (status) {
>> + queue->tls_err = -status;
>> + goto out_complete;
>> + }
>> +
>> + tls_key = key_lookup(pskid);
>> + if (IS_ERR(tls_key)) {
>> + dev_warn(ctrl->ctrl.device, "queue %d: Invalid key %x\n",
>> + qid, pskid);
>> + queue->tls_err = -ENOKEY;
>> + } else {
>> + ctrl->ctrl.tls_key = tls_key;
>> + queue->tls_err = 0;
>> + }
>> +
>> +out_complete:
>> + complete(&queue->tls_complete);
>> +}
>> +
>> +static int nvme_tcp_start_tls(struct nvme_ctrl *nctrl,
>> + struct nvme_tcp_queue *queue,
>> + key_serial_t pskid)
>> +{
>> + int qid = nvme_tcp_queue_id(queue);
>> + int ret;
>> + struct tls_handshake_args args;
>> + unsigned long tmo = tls_handshake_timeout * HZ;
>> + key_serial_t keyring = nvme_keyring_id();
>> +
>> + dev_dbg(nctrl->device, "queue %d: start TLS with key %x\n",
>> + qid, pskid);
>> + args.ta_sock = queue->sock;
>> + args.ta_done = nvme_tcp_tls_done;
>> + args.ta_data = queue;
>> + args.ta_my_peerids[0] = pskid;
>> + args.ta_num_peerids = 1;
>> + args.ta_keyring = keyring;
>> + args.ta_timeout_ms = tls_handshake_timeout * 1000;
>> + queue->tls_err = -EOPNOTSUPP;
>> + init_completion(&queue->tls_complete);
>> + ret = tls_client_hello_psk(&args, GFP_KERNEL);
>> + if (ret) {
>> + dev_err(nctrl->device, "queue %d: failed to start TLS: %d\n",
>> + qid, ret);
>> + return ret;
>> + }
>> + if (wait_for_completion_timeout(&queue->tls_complete, tmo) == 0) {
>> + dev_err(nctrl->device,
>> + "queue %d: TLS handshake timeout\n", qid);
>> + ret = -ETIMEDOUT;
>> + } else {
>> + dev_dbg(nctrl->device,
>> + "queue %d: TLS handshake complete, error %d\n",
>> + qid, queue->tls_err);
>> + ret = queue->tls_err;
>> + }
>> + return ret;
>> +}
>> +#endif
>> +
>> +static int nvme_tcp_alloc_queue(struct nvme_ctrl *nctrl, int qid,
>> + key_serial_t pskid)
>> {
>> struct nvme_tcp_ctrl *ctrl = to_tcp_ctrl(nctrl);
>> struct nvme_tcp_queue *queue = &ctrl->queues[qid];
>> @@ -1626,6 +1715,14 @@ static int nvme_tcp_alloc_queue(struct
>> nvme_ctrl *nctrl, int qid)
>> goto err_rcv_pdu;
>> }
>> +#ifdef CONFIG_NVME_TCP_TLS
>> + /* If PSKs are configured try to start TLS */
>> + if (pskid) {
>> + ret = nvme_tcp_start_tls(nctrl, queue, pskid);
>> + if (ret)
>> + goto err_init_connect;
>> + }
>> +#endif
>
> Maybe reduce ifdef here and use IS_ENABLED ? (might be done in
> nvme_tcp_start_tls too)
>
Then I would need to have a dummy definition for 'nvme_tcp_start_tls';
but yeah, could do.
>> ret = nvme_tcp_init_connection(queue);
>> if (ret)
>> goto err_init_connect;
>> @@ -1769,10 +1866,22 @@ static int nvme_tcp_start_io_queues(struct
>> nvme_ctrl *ctrl,
>> static int nvme_tcp_alloc_admin_queue(struct nvme_ctrl *ctrl)
>> {
>> int ret;
>> + key_serial_t psk_id = 0;
>> +
>> + if (ctrl->opts->tls) {
>> + psk_id = nvme_tls_psk_default(NULL,
>> + ctrl->opts->host->nqn,
>> + ctrl->opts->subsysnqn);
>> + if (!psk_id) {
>> + dev_err(ctrl->device, "no valid PSK found\n");
>> + ret = -ENOKEY;
>> + goto out_free_queue;
>> + }
>> + }
>> - ret = nvme_tcp_alloc_queue(ctrl, 0);
>> + ret = nvme_tcp_alloc_queue(ctrl, 0, psk_id);
>> if (ret)
>> - return ret;
>> + goto out_free_queue;
>> ret = nvme_tcp_alloc_async_req(to_tcp_ctrl(ctrl));
>> if (ret)
>> @@ -1788,9 +1897,17 @@ static int nvme_tcp_alloc_admin_queue(struct
>> nvme_ctrl *ctrl)
>> static int __nvme_tcp_alloc_io_queues(struct nvme_ctrl *ctrl)
>> {
>> int i, ret;
>> + key_serial_t psk_id = 0;
>> + if (ctrl->opts->tls) {
>> + if (!ctrl->tls_key) {
>> + dev_err(ctrl->device, "no PSK negotiated\n");
>> + return -ENOKEY;
>> + }
>> + psk_id = key_serial(ctrl->tls_key);
>> + }
>> for (i = 1; i < ctrl->queue_count; i++) {
>> - ret = nvme_tcp_alloc_queue(ctrl, i);
>> + ret = nvme_tcp_alloc_queue(ctrl, i, psk_id);
>> if (ret)
>> goto out_free_queues;
>> }
>> @@ -2699,7 +2816,7 @@ static struct nvmf_transport_ops
>> nvme_tcp_transport = {
>> NVMF_OPT_HOST_TRADDR | NVMF_OPT_CTRL_LOSS_TMO |
>> 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_TOS | NVMF_OPT_HOST_IFACE | NVMF_OPT_TLS,
>> .create_ctrl = nvme_tcp_create_ctrl,
>> };
Cheers,
Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
hare at suse.de +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman
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