[PATCH 11/17] nvme-tcp: enable TLS handshake upcall
Max Gurtovoy
mgurtovoy at nvidia.com
Tue May 9 16:16:45 PDT 2023
On 09/05/2023 17:22, Hannes Reinecke wrote:
> 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.
nvme-cli will determine tls support using check for "static const
match_table_t opt_tokens" ?
>
>>> + { 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);
After the patch squash you will not need this defaulk psk and also the
opts->tls.
Why not ask the user provide it explicitly always ? why do we need a
default ?
I'm not TLS expert, but seem redundant..
>>> + 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
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