Add scsi_cdb_sbuf() for handling CDB strings. Reimplement scsi_cdb_string()

in terms of it.

Reviewed by:	imp, mav, ken
MFC after:	3 days
Sponsored by:	Netflix
Differential Revision:	D5934

2 files changed, 26 insertions, 8 deletions

diff --git a/sys/cam/scsi/scsi_all.c b/sys/cam/scsi/scsi_all.c
index 023103b..0c40899 100644
--- a/sys/cam/scsi/scsi_all.c
+++ b/sys/cam/scsi/scsi_all.c
@@ -3464,14 +3464,32 @@ scsi_error_action(struct ccb_scsiio *csio, struct scsi_inquiry_data *inq_data,
 char *
 scsi_cdb_string(u_int8_t *cdb_ptr, char *cdb_string, size_t len)
 {
+	struct sbuf sb;
+	int error;
+
+	if (len == 0)
+		return ("");
+
+	sbuf_new(&sb, cdb_string, len, SBUF_FIXEDLEN);
+
+	scsi_cdb_sbuf(cdb_ptr, &sb);
+
+	/* ENOMEM just means that the fixed buffer is full, OK to ignore */
+	error = sbuf_finish(&sb);
+	if (error != 0 && error != ENOMEM)
+		return ("");
+
+	return(sbuf_data(&sb));
+}
+
+void
+scsi_cdb_sbuf(u_int8_t *cdb_ptr, struct sbuf *sb)
+{
 	u_int8_t cdb_len;
 	int i;
 
 	if (cdb_ptr == NULL)
-		return("");
-
-	/* Silence warnings */
-	cdb_len = 0;
+		return;
 
 	/*
 	 * This is taken from the SCSI-3 draft spec.
@@ -3508,12 +3526,11 @@ scsi_cdb_string(u_int8_t *cdb_ptr, char *cdb_string, size_t len)
 			cdb_len = 12;
 			break;
 	}
-	*cdb_string = '\0';
+
 	for (i = 0; i < cdb_len; i++)
-		snprintf(cdb_string + strlen(cdb_string),
-			 len - strlen(cdb_string), "%02hhx ", cdb_ptr[i]);
+		sbuf_printf(sb, "%02hhx ", cdb_ptr[i]);
 
-	return(cdb_string);
+	return;
 }
 
 const char *
diff --git a/sys/cam/scsi/scsi_all.h b/sys/cam/scsi/scsi_all.h
index 997a58c..e5b492f 100644
--- a/sys/cam/scsi/scsi_all.h
+++ b/sys/cam/scsi/scsi_all.h
@@ -3646,6 +3646,7 @@ const char *	scsi_op_desc(u_int16_t opcode,
 			     struct scsi_inquiry_data *inq_data);
 char *		scsi_cdb_string(u_int8_t *cdb_ptr, char *cdb_string,
 				size_t len);
+void		scsi_cdb_sbuf(u_int8_t *cdb_ptr, struct sbuf *sb);
 
 void		scsi_print_inquiry(struct scsi_inquiry_data *inq_data);
 void		scsi_print_inquiry_short(struct scsi_inquiry_data *inq_data);