scsi: target: consistently null-terminate t10_wwn strings

In preparation for supporting user provided vendor strings, add an extra
byte to the vendor, model and revision arrays in struct t10_wwn. This
ensures that the full INQUIRY data can be carried in the arrays along with
a null-terminator.

Change a number of array readers and writers so that they account for
explicit null-termination:

- The pscsi_set_inquiry_info() and emulate_model_alias_store() codepaths
  don't currently explicitly null-terminate; fix this.

- Existing t10_wwn field dumps use for-loops which step over
  null-terminators for right-padding.
  + Use printf with width specifiers instead.

Signed-off-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: Roman Bolshakov <r.bolshakov@yadro.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 16 insertions, 34 deletions

diff --git a/drivers/target/target_core_pscsi.c b/drivers/target/target_core_pscsi.c
index 47d76c862014..c346ad3ee4e0 100644
--- a/drivers/target/target_core_pscsi.c
+++ b/drivers/target/target_core_pscsi.c
@@ -179,20 +179,20 @@ out_free:
 static void
 pscsi_set_inquiry_info(struct scsi_device *sdev, struct t10_wwn *wwn)
 {
-	unsigned char *buf;
-
 	if (sdev->inquiry_len < INQUIRY_LEN)
 		return;
-
-	buf = sdev->inquiry;
-	if (!buf)
-		return;
 	/*
-	 * Use sdev->inquiry from drivers/scsi/scsi_scan.c:scsi_alloc_sdev()
+	 * Use sdev->inquiry data from drivers/scsi/scsi_scan.c:scsi_add_lun()
 	 */
-	memcpy(&wwn->vendor[0], &buf[8], sizeof(wwn->vendor));
-	memcpy(&wwn->model[0], &buf[16], sizeof(wwn->model));
-	memcpy(&wwn->revision[0], &buf[32], sizeof(wwn->revision));
+	BUILD_BUG_ON(sizeof(wwn->vendor) != INQUIRY_VENDOR_LEN + 1);
+	snprintf(wwn->vendor, sizeof(wwn->vendor),
+		 "%." __stringify(INQUIRY_VENDOR_LEN) "s", sdev->vendor);
+	BUILD_BUG_ON(sizeof(wwn->model) != INQUIRY_MODEL_LEN + 1);
+	snprintf(wwn->model, sizeof(wwn->model),
+		 "%." __stringify(INQUIRY_MODEL_LEN) "s", sdev->model);
+	BUILD_BUG_ON(sizeof(wwn->revision) != INQUIRY_REVISION_LEN + 1);
+	snprintf(wwn->revision, sizeof(wwn->revision),
+		 "%." __stringify(INQUIRY_REVISION_LEN) "s", sdev->rev);
 }
 
 static int
@@ -811,7 +811,6 @@ static ssize_t pscsi_show_configfs_dev_params(struct se_device *dev, char *b)
 	struct scsi_device *sd = pdv->pdv_sd;
 	unsigned char host_id[16];
 	ssize_t bl;
-	int i;
 
 	if (phv->phv_mode == PHV_VIRTUAL_HOST_ID)
 		snprintf(host_id, 16, "%d", pdv->pdv_host_id);
@@ -824,29 +823,12 @@ static ssize_t pscsi_show_configfs_dev_params(struct se_device *dev, char *b)
 		host_id);
 
 	if (sd) {
-		bl += sprintf(b + bl, "        ");
-		bl += sprintf(b + bl, "Vendor: ");
-		for (i = 0; i < 8; i++) {
-			if (ISPRINT(sd->vendor[i]))   /* printable character? */
-				bl += sprintf(b + bl, "%c", sd->vendor[i]);
-			else
-				bl += sprintf(b + bl, " ");
-		}
-		bl += sprintf(b + bl, " Model: ");
-		for (i = 0; i < 16; i++) {
-			if (ISPRINT(sd->model[i]))   /* printable character ? */
-				bl += sprintf(b + bl, "%c", sd->model[i]);
-			else
-				bl += sprintf(b + bl, " ");
-		}
-		bl += sprintf(b + bl, " Rev: ");
-		for (i = 0; i < 4; i++) {
-			if (ISPRINT(sd->rev[i]))   /* printable character ? */
-				bl += sprintf(b + bl, "%c", sd->rev[i]);
-			else
-				bl += sprintf(b + bl, " ");
-		}
-		bl += sprintf(b + bl, "\n");
+		bl += sprintf(b + bl, "        Vendor: %."
+			__stringify(INQUIRY_VENDOR_LEN) "s", sd->vendor);
+		bl += sprintf(b + bl, " Model: %."
+			__stringify(INQUIRY_MODEL_LEN) "s", sd->model);
+		bl += sprintf(b + bl, " Rev: %."
+			__stringify(INQUIRY_REVISION_LEN) "s\n", sd->rev);
 	}
 	return bl;
 }