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-rw-r--r--drivers/nvme/common/keyring.c185
1 files changed, 185 insertions, 0 deletions
diff --git a/drivers/nvme/common/keyring.c b/drivers/nvme/common/keyring.c
new file mode 100644
index 0000000000..ee341b83ee
--- /dev/null
+++ b/drivers/nvme/common/keyring.c
@@ -0,0 +1,185 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2023 Hannes Reinecke, SUSE Labs
+ */
+
+#include <linux/module.h>
+#include <linux/seq_file.h>
+#include <linux/key.h>
+#include <linux/key-type.h>
+#include <keys/user-type.h>
+#include <linux/nvme.h>
+#include <linux/nvme-tcp.h>
+#include <linux/nvme-keyring.h>
+
+static struct key *nvme_keyring;
+
+key_serial_t nvme_keyring_id(void)
+{
+ return nvme_keyring->serial;
+}
+EXPORT_SYMBOL_GPL(nvme_keyring_id);
+
+static void nvme_tls_psk_describe(const struct key *key, struct seq_file *m)
+{
+ seq_puts(m, key->description);
+ seq_printf(m, ": %u", key->datalen);
+}
+
+static bool nvme_tls_psk_match(const struct key *key,
+ const struct key_match_data *match_data)
+{
+ const char *match_id;
+ size_t match_len;
+
+ if (!key->description) {
+ pr_debug("%s: no key description\n", __func__);
+ return false;
+ }
+ match_len = strlen(key->description);
+ pr_debug("%s: id %s len %zd\n", __func__, key->description, match_len);
+
+ if (!match_data->raw_data) {
+ pr_debug("%s: no match data\n", __func__);
+ return false;
+ }
+ match_id = match_data->raw_data;
+ pr_debug("%s: match '%s' '%s' len %zd\n",
+ __func__, match_id, key->description, match_len);
+ return !memcmp(key->description, match_id, match_len);
+}
+
+static int nvme_tls_psk_match_preparse(struct key_match_data *match_data)
+{
+ match_data->lookup_type = KEYRING_SEARCH_LOOKUP_ITERATE;
+ match_data->cmp = nvme_tls_psk_match;
+ return 0;
+}
+
+static struct key_type nvme_tls_psk_key_type = {
+ .name = "psk",
+ .flags = KEY_TYPE_NET_DOMAIN,
+ .preparse = user_preparse,
+ .free_preparse = user_free_preparse,
+ .match_preparse = nvme_tls_psk_match_preparse,
+ .instantiate = generic_key_instantiate,
+ .revoke = user_revoke,
+ .destroy = user_destroy,
+ .describe = nvme_tls_psk_describe,
+ .read = user_read,
+};
+
+static struct key *nvme_tls_psk_lookup(struct key *keyring,
+ const char *hostnqn, const char *subnqn,
+ int hmac, bool generated)
+{
+ char *identity;
+ size_t identity_len = (NVMF_NQN_SIZE) * 2 + 11;
+ key_ref_t keyref;
+ key_serial_t keyring_id;
+
+ identity = kzalloc(identity_len, GFP_KERNEL);
+ if (!identity)
+ return ERR_PTR(-ENOMEM);
+
+ snprintf(identity, identity_len, "NVMe0%c%02d %s %s",
+ generated ? 'G' : 'R', hmac, hostnqn, subnqn);
+
+ if (!keyring)
+ keyring = nvme_keyring;
+ keyring_id = key_serial(keyring);
+ pr_debug("keyring %x lookup tls psk '%s'\n",
+ keyring_id, identity);
+ keyref = keyring_search(make_key_ref(keyring, true),
+ &nvme_tls_psk_key_type,
+ identity, false);
+ if (IS_ERR(keyref)) {
+ pr_debug("lookup tls psk '%s' failed, error %ld\n",
+ identity, PTR_ERR(keyref));
+ kfree(identity);
+ return ERR_PTR(-ENOKEY);
+ }
+ kfree(identity);
+
+ return key_ref_to_ptr(keyref);
+}
+
+/*
+ * NVMe PSK priority list
+ *
+ * 'Retained' PSKs (ie 'generated == false')
+ * should be preferred to 'generated' PSKs,
+ * and SHA-384 should be preferred to SHA-256.
+ */
+struct nvme_tls_psk_priority_list {
+ bool generated;
+ enum nvme_tcp_tls_cipher cipher;
+} nvme_tls_psk_prio[] = {
+ { .generated = false,
+ .cipher = NVME_TCP_TLS_CIPHER_SHA384, },
+ { .generated = false,
+ .cipher = NVME_TCP_TLS_CIPHER_SHA256, },
+ { .generated = true,
+ .cipher = NVME_TCP_TLS_CIPHER_SHA384, },
+ { .generated = true,
+ .cipher = NVME_TCP_TLS_CIPHER_SHA256, },
+};
+
+/*
+ * nvme_tls_psk_default - Return the preferred PSK to use for TLS ClientHello
+ */
+key_serial_t nvme_tls_psk_default(struct key *keyring,
+ const char *hostnqn, const char *subnqn)
+{
+ struct key *tls_key;
+ key_serial_t tls_key_id;
+ int prio;
+
+ for (prio = 0; prio < ARRAY_SIZE(nvme_tls_psk_prio); prio++) {
+ bool generated = nvme_tls_psk_prio[prio].generated;
+ enum nvme_tcp_tls_cipher cipher = nvme_tls_psk_prio[prio].cipher;
+
+ tls_key = nvme_tls_psk_lookup(keyring, hostnqn, subnqn,
+ cipher, generated);
+ if (!IS_ERR(tls_key)) {
+ tls_key_id = tls_key->serial;
+ key_put(tls_key);
+ return tls_key_id;
+ }
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(nvme_tls_psk_default);
+
+static int __init nvme_keyring_init(void)
+{
+ int err;
+
+ nvme_keyring = keyring_alloc(".nvme",
+ GLOBAL_ROOT_UID, GLOBAL_ROOT_GID,
+ current_cred(),
+ (KEY_POS_ALL & ~KEY_POS_SETATTR) |
+ (KEY_USR_ALL & ~KEY_USR_SETATTR),
+ KEY_ALLOC_NOT_IN_QUOTA, NULL, NULL);
+ if (IS_ERR(nvme_keyring))
+ return PTR_ERR(nvme_keyring);
+
+ err = register_key_type(&nvme_tls_psk_key_type);
+ if (err) {
+ key_put(nvme_keyring);
+ return err;
+ }
+ return 0;
+}
+
+static void __exit nvme_keyring_exit(void)
+{
+ unregister_key_type(&nvme_tls_psk_key_type);
+ key_revoke(nvme_keyring);
+ key_put(nvme_keyring);
+}
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Hannes Reinecke <hare@suse.de>");
+module_init(nvme_keyring_init);
+module_exit(nvme_keyring_exit);