nvme: expose tls mode in use

It is not possible to determine the active TLS mode from the
presence or absence of sysfs attributes like tls_key,
tls_configured_key, or dhchap_secret.

With the introduction of the concat mode and optional DH-CHAP
authentication, different configurations can result in identical
sysfs state. This makes user space detection unreliable.

Read the TLS mode used from the newly added sysfs entry.

(cherry picked from d0c4d3aedb1c)
Signed-off-by: Daniel Wagner <[email protected]>

Author: igaw

src/nvme/tree.c

@@ -1980,6 +1980,20 @@ static char *nvme_ctrl_lookup_phy_slot(nvme_root_t r, const char *address)
 	return NULL;
 }
 
+static void nvme_read_sysfs_tls_mode(nvme_root_t r, nvme_ctrl_t c)
+{
+	_cleanup_free_ char *mode = NULL;
+
+	mode = nvme_get_ctrl_attr(c, "tls_mode");
+	if (!mode)
+		return;
+
+	if (!strcmp(mode, "tls"))
+		c->cfg.tls = true;
+	else if (!strcmp(mode, "concat"))
+		c->cfg.concat = true;
+}
+
 static void nvme_read_sysfs_dhchap(nvme_root_t r, nvme_ctrl_t c)
 {
 	char *host_key, *ctrl_key;
@@ -2088,6 +2102,7 @@ static int nvme_reconfigure_ctrl(nvme_root_t r, nvme_ctrl_t c, const char *path,
 	c->phy_slot = nvme_ctrl_lookup_phy_slot(r, c->address);
 	nvme_read_sysfs_dhchap(r, c);
 	nvme_read_sysfs_tls(r, c);
+	nvme_read_sysfs_tls_mode(r, c);
 
 	errno = 0; /* cleanup after nvme_get_ctrl_attr() */
 	return 0;