From bb729f758195a36db1dd0d5c01ec983e466729eb Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@redhat.com>
Date: Wed, 5 Sep 2012 17:57:19 +0200
Subject: [PATCH] scsi: introduce scsi_cdb_length and scsi_data_cdb_length

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 hw/scsi-bus.c | 23 ++++++++++++++++++-----
 hw/scsi.h     |  2 ++
 2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/hw/scsi-bus.c b/hw/scsi-bus.c
index 4981a02..058d3b2 100644
--- a/hw/scsi-bus.c
+++ b/hw/scsi-bus.c
@@ -801,26 +801,39 @@ static int ata_passthrough_16_xfer_size(SCSIDevice *dev, uint8_t *buf)
     return xfer * unit;
 }
 
-static int scsi_req_length(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
+uint32_t scsi_data_cdb_length(uint8_t *buf)
+{
+    if ((buf[0] >> 5) == 0 && buf[4] == 0) {
+        return 256;
+    } else {
+        return scsi_cdb_length(buf);
+    }
+}
+
+uint32_t scsi_cdb_length(uint8_t *buf)
 {
     switch (buf[0] >> 5) {
     case 0:
-        cmd->xfer = buf[4];
+        return buf[4];
         break;
     case 1:
     case 2:
-        cmd->xfer = lduw_be_p(&buf[7]);
+        return lduw_be_p(&buf[7]);
         break;
     case 4:
-        cmd->xfer = ldl_be_p(&buf[10]) & 0xffffffffULL;
+        return ldl_be_p(&buf[10]) & 0xffffffffULL;
         break;
     case 5:
-        cmd->xfer = ldl_be_p(&buf[6]) & 0xffffffffULL;
+        return ldl_be_p(&buf[6]) & 0xffffffffULL;
         break;
     default:
         return -1;
     }
+}
 
+static int scsi_req_length(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
+{
+    cmd->xfer = scsi_cdb_length(buf);
     switch (buf[0]) {
     case TEST_UNIT_READY:
     case REWIND:
diff --git a/hw/scsi.h b/hw/scsi.h
index 1aeee46..b8f7357 100644
--- a/hw/scsi.h
+++ b/hw/scsi.h
@@ -218,6 +218,8 @@ extern const struct SCSISense sense_code_WRITE_PROTECTED;
 
 #define SENSE_CODE(x) sense_code_ ## x
 
+uint32_t scsi_data_cdb_length(uint8_t *buf);
+uint32_t scsi_cdb_length(uint8_t *buf);
 int scsi_sense_valid(SCSISense sense);
 int scsi_build_sense(uint8_t *in_buf, int in_len,
                      uint8_t *buf, int len, bool fixed);
-- 
2.7.4