Regularize the format of the "(size)" tags - the SCSI specs appear not

to put a space between the command name and the tag, and we weren't
doing that for all tags, so let's just get rid of the space.

Keep track of the device type and command type separately for commands.

Remember device types when we see an INQUIRY *response*, not a request,
and save the device type bits, rather than saving some random bit from the
INQUIRY *request* as the device type.  This means we have to dissect
the INQUIRY response payload even if we're not building a protocol tree;
do so.

Put in a comment noting that the source and destination address are not
sufficient as a key to use for the device type, as a given network-layer
entity may have more than one SCSI device (and connections aren't good
enough, either).

Put the code to dissect MODE SELECT and MODE SENSE block descriptors
into a common routine.  Have that routine dissect more than one block
descriptor.  Have it take the device type and the "long LBA" flag as
arguments, so that it can correctly dissect the block descriptors.

Handle READ(6) and WRITE(6) on sequential devices.

Get rid of "dissect_scsi()" - it's not used.

svn path=/trunk/; revision=6032

1 files changed, 411 insertions, 219 deletions

diff --git a/packet-scsi.c b/packet-scsi.c
index 268c8606a1..da9d0868e5 100644
--- a/packet-scsi.c
+++ b/packet-scsi.c
@@ -2,7 +2,7 @@
  * Routines for decoding SCSI CDBs and responses
  * Author: Dinesh G Dutt (ddutt@cisco.com)
  *
- * $Id: packet-scsi.c,v 1.13 2002/08/19 13:06:43 guy Exp $
+ * $Id: packet-scsi.c,v 1.14 2002/08/20 03:21:42 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@ethereal.com>
@@ -83,6 +83,7 @@
 #include <string.h>
 #include <epan/strutil.h>
 #include <epan/conversation.h>
+#include <epan/int-64bit.h>
 #include "prefs.h"
 #include "packet-scsi.h"
 
@@ -162,7 +163,7 @@ static gint ett_scsi_page    = -1;
 typedef guint32 scsi_cmnd_type;
 typedef guint32 scsi_device_type;
 
-/* Valid SCSI Device Types */
+/* Valid SCSI Command Types */
 #define SCSI_CMND_SPC2                   1
 #define SCSI_CMND_SBC2                   2
 #define SCSI_CMND_SSC2                   3
@@ -201,23 +202,23 @@ static const value_string scsi_spc2_val[] = {
     {SCSI_SPC2_INQUIRY           , "Inquiry"},
     {SCSI_SPC2_LOGSELECT         , "Log Select"},
     {SCSI_SPC2_LOGSENSE          , "Log Sense"},
-    {SCSI_SPC2_MODESELECT6       , "Mode Select (6)"},
-    {SCSI_SPC2_MODESELECT10      , "Mode Select (10)"},
-    {SCSI_SPC2_MODESENSE6        , "Mode Sense (6)"},
-    {SCSI_SPC2_MODESENSE10       , "Mode Sense (10)"},
+    {SCSI_SPC2_MODESELECT6       , "Mode Select(6)"},
+    {SCSI_SPC2_MODESELECT10      , "Mode Select(10)"},
+    {SCSI_SPC2_MODESENSE6        , "Mode Sense(6)"},
+    {SCSI_SPC2_MODESENSE10       , "Mode Sense(10)"},
     {SCSI_SPC2_PERSRESVIN        , "Persistent Reserve In"},
     {SCSI_SPC2_PERSRESVOUT       , "Persistent Reserve Out"},
     {SCSI_SPC2_PREVMEDREMOVAL    , "Prevent/Allow Medium Removal"},
     {SCSI_SPC2_RCVCOPYRESULTS    , "Receive Copy Results"},
     {SCSI_SPC2_RCVDIAGRESULTS    , "Receive Diagnostics Results"},
     {SCSI_SPC2_READBUFFER        , "Read Buffer"},
-    {SCSI_SPC2_RELEASE6          , "Release (6)"},
-    {SCSI_SPC2_RELEASE10         , "Release (10)"},
+    {SCSI_SPC2_RELEASE6          , "Release(6)"},
+    {SCSI_SPC2_RELEASE10         , "Release(10)"},
     {SCSI_SPC2_REPORTDEVICEID    , "Report Device ID"},
     {SCSI_SPC2_REPORTLUNS        , "Report LUNs"},
     {SCSI_SPC2_REQSENSE          , "Request Sense"},
-    {SCSI_SPC2_RESERVE6          , "Reserve (6)"},
-    {SCSI_SPC2_RESERVE10         , "Reserve (10)"},
+    {SCSI_SPC2_RESERVE6          , "Reserve(6)"},
+    {SCSI_SPC2_RESERVE10         , "Reserve(10)"},
     {SCSI_SPC2_TESTUNITRDY       , "Test Unit Ready"},
     {SCSI_SPC2_WRITEBUFFER       , "Write Buffer"},
     {SCSI_SPC2_VARLENCDB         , "Variable Length CDB"},
@@ -276,52 +277,52 @@ static const value_string scsi_spc2_val[] = {
 
 static const value_string scsi_sbc2_val[] = {
     {SCSI_SBC2_FORMATUNIT    , "Format Unit"},
-    {SCSI_SBC2_LOCKUNLKCACHE10, "Lock Unlock Cache (10)"},
-    {SCSI_SPC2_LOCKUNLKCACHE16, "Lock Unlock Cache (16)"},
-    {SCSI_SBC2_PREFETCH10, "Pre-Fetch (10)"},
-    {SCSI_SBC2_PREFETCH16, "Pre-Fetch (16)"},
-    {SCSI_SBC2_READ6         , "Read (6)"},
-    {SCSI_SBC2_READ10        , "Read (10)"},
-    {SCSI_SBC2_READ12        , "Read (12)"},
-    {SCSI_SBC2_READ16        , "Read (16)"},
+    {SCSI_SBC2_LOCKUNLKCACHE10, "Lock Unlock Cache(10)"},
+    {SCSI_SPC2_LOCKUNLKCACHE16, "Lock Unlock Cache(16)"},
+    {SCSI_SBC2_PREFETCH10, "Pre-Fetch(10)"},
+    {SCSI_SBC2_PREFETCH16, "Pre-Fetch(16)"},
+    {SCSI_SBC2_READ6         , "Read(6)"},
+    {SCSI_SBC2_READ10        , "Read(10)"},
+    {SCSI_SBC2_READ12        , "Read(12)"},
+    {SCSI_SBC2_READ16        , "Read(16)"},
     {SCSI_SBC2_READCAPACITY  , "Read Capacity"},
-    {SCSI_SBC2_READDEFDATA10 , "Read Defect Data (10)"},
-    {SCSI_SBC2_READDEFDATA12 , "Read Defect Data (12)"},
+    {SCSI_SBC2_READDEFDATA10 , "Read Defect Data(10)"},
+    {SCSI_SBC2_READDEFDATA12 , "Read Defect Data(12)"},
     {SCSI_SBC2_READLONG, "Read Long"},
     {SCSI_SBC2_REASSIGNBLKS  , "Reassign Blocks"},
-    {SCSI_SBC2_REBUILD16, "Rebuild (16)"},
-    {SCSI_SBC2_REBUILD32, "Rebuild (32)"},
-    {SCSI_SBC2_REGENERATE16, "Regenerate (16)"},
-    {SCSI_SBC2_REGENERATE32, "Regenerate (32)"},
-    {SCSI_SBC2_SEEK10, "Seek (10)"},
-    {SCSI_SBC2_SETLIMITS10, "Set Limits (10)"},
-    {SCSI_SBC2_SETLIMITS12, "Set Limits (12)"},
+    {SCSI_SBC2_REBUILD16, "Rebuild(16)"},
+    {SCSI_SBC2_REBUILD32, "Rebuild(32)"},
+    {SCSI_SBC2_REGENERATE16, "Regenerate(16)"},
+    {SCSI_SBC2_REGENERATE32, "Regenerate(32)"},
+    {SCSI_SBC2_SEEK10, "Seek(10)"},
+    {SCSI_SBC2_SETLIMITS10, "Set Limits(10)"},
+    {SCSI_SBC2_SETLIMITS12, "Set Limits(12)"},
     {SCSI_SBC2_STARTSTOPUNIT, "Start Stop Unit"},
-    {SCSI_SBC2_SYNCCACHE10, "Synchronize Cache (10)"},
-    {SCSI_SBC2_SYNCCACHE16, "Synchronize Cache (16)"},
-    {SCSI_SBC2_VERIFY10, "Verify (10)"},
-    {SCSI_SBC2_VERIFY12, "Verify (12)"},
-    {SCSI_SBC2_VERIFY16, "Verify (16)"},
-    {SCSI_SBC2_WRITE6        , "Write (6)"},
-    {SCSI_SBC2_WRITE10       , "Write (10)"},
-    {SCSI_SBC2_WRITE12       , "Write (12)"},
-    {SCSI_SBC2_WRITE16       , "Write (16)"},
-    {SCSI_SBC2_WRITENVERIFY10, "Write & Verify (10)"},
-    {SCSI_SBC2_WRITENVERIFY12, "Write & Verify (12)"},
-    {SCSI_SBC2_WRITENVERIFY16, "Write & Verify (16)"},
+    {SCSI_SBC2_SYNCCACHE10, "Synchronize Cache(10)"},
+    {SCSI_SBC2_SYNCCACHE16, "Synchronize Cache(16)"},
+    {SCSI_SBC2_VERIFY10, "Verify(10)"},
+    {SCSI_SBC2_VERIFY12, "Verify(12)"},
+    {SCSI_SBC2_VERIFY16, "Verify(16)"},
+    {SCSI_SBC2_WRITE6        , "Write(6)"},
+    {SCSI_SBC2_WRITE10       , "Write(10)"},
+    {SCSI_SBC2_WRITE12       , "Write(12)"},
+    {SCSI_SBC2_WRITE16       , "Write(16)"},
+    {SCSI_SBC2_WRITENVERIFY10, "Write & Verify(10)"},
+    {SCSI_SBC2_WRITENVERIFY12, "Write & Verify(12)"},
+    {SCSI_SBC2_WRITENVERIFY16, "Write & Verify(16)"},
     {SCSI_SBC2_WRITELONG, "Write Long"},
-    {SCSI_SBC2_WRITESAME10, "Write Same (10)"},
-    {SCSI_SBC2_WRITESAME16, "Write Same (16)"},
-    {SCSI_SBC2_XDREAD10, "XdRead (10)"},
-    {SCSI_SBC2_XDREAD32, "XdRead (32)"},
-    {SCSI_SBC2_XDWRITE10, "XdWrite (10)"},
+    {SCSI_SBC2_WRITESAME10, "Write Same(10)"},
+    {SCSI_SBC2_WRITESAME16, "Write Same(16)"},
+    {SCSI_SBC2_XDREAD10, "XdRead(10)"},
+    {SCSI_SBC2_XDREAD32, "XdRead(32)"},
+    {SCSI_SBC2_XDWRITE10, "XdWrite(10)"},
     {SCSI_SBC2_XDWRITE32, "XdWrite(32)"},
-    {SCSI_SBC2_XDWRITEREAD10, "XdWriteRead (10)"},
-    {SCSI_SBC2_XDWRITEREAD32, "XdWriteRead (32)"},
-    {SCSI_SBC2_XDWRITEEXTD16, "XdWrite Extended (16)"},
-    {SCSI_SBC2_XDWRITEEXTD32, "XdWrite Extended (32)"},
-    {SCSI_SBC2_XPWRITE10, "XpWrite (10)"},
-    {SCSI_SBC2_XPWRITE32, "XpWrite (32)"},
+    {SCSI_SBC2_XDWRITEREAD10, "XdWriteRead(10)"},
+    {SCSI_SBC2_XDWRITEREAD32, "XdWriteRead(32)"},
+    {SCSI_SBC2_XDWRITEEXTD16, "XdWrite Extended(16)"},
+    {SCSI_SBC2_XDWRITEEXTD32, "XdWrite Extended(32)"},
+    {SCSI_SBC2_XPWRITE10, "XpWrite(10)"},
+    {SCSI_SBC2_XPWRITE32, "XpWrite(32)"},
     {0, NULL},
 };
 
@@ -349,11 +350,11 @@ static const value_string scsi_sbc2_val[] = {
 #define SCSI_SSC2_ERASE_6                       0x19
 #define SCSI_SSC2_LOCATE_10                     0x2B
 #define SCSI_SSC2_LOCATE_16                     0x92
-#define SCSI_SSC2_READ_6                        0x08
+#define SCSI_SSC2_READ6                         0x08
 #define SCSI_SSC2_READ_REVERSE_6                0x0F
 #define SCSI_SSC2_SPACE_6                       0x11
 #define SCSI_SSC2_VERIFY_6                      0x13
-#define SCSI_SSC2_WRITE_6                       0x0A
+#define SCSI_SSC2_WRITE6                        0x0A
 #define SCSI_SSC2_WRITE_FILEMARKS_6             0x10
 
 static const value_string scsi_ssc2_val[] = {
@@ -380,11 +381,11 @@ static const value_string scsi_ssc2_val[] = {
     {SCSI_SSC2_ERASE_6                     , "Erase(6)"},
     {SCSI_SSC2_LOCATE_10                   , "Locate(10)"},
     {SCSI_SSC2_LOCATE_16                   , "Locate(16)"},
-    {SCSI_SSC2_READ_6                      , "Read(6)"},
+    {SCSI_SSC2_READ6                       , "Read(6)"},
     {SCSI_SSC2_READ_REVERSE_6              , "Read Reverse(6)"},
     {SCSI_SSC2_SPACE_6                     , "Space(6)"},
     {SCSI_SSC2_VERIFY_6                    , "Verify(6)"},
-    {SCSI_SSC2_WRITE_6                     , "Write(6)"},
+    {SCSI_SSC2_WRITE6                      , "Write(6)"},
     {SCSI_SSC2_WRITE_FILEMARKS_6           , "Write Filemarks(6)"},
 };
 
@@ -1094,6 +1095,7 @@ static gint scsi_def_devtype = SCSI_DEV_SBC;
  */
 typedef struct _scsi_task_data {
     guint32 opcode;
+    scsi_cmnd_type cmd;
     scsi_device_type devtype;
     guint8 flags;               /* used by SCSI Inquiry */
 } scsi_task_data_t;
@@ -1388,20 +1390,31 @@ dissect_scsi_inquiry (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
     scsi_devtype_data_t *devdata = NULL;
     scsi_devtype_key_t dkey, *req_key;
 
-    /* Add device type to list of known devices & their types */
-    COPY_ADDRESS (&(dkey.devid), &(pinfo->src));
-    devdata = (scsi_devtype_data_t *)g_hash_table_lookup (scsidev_req_hash,
-                                                          &dkey);
-    if (!devdata) {
-        req_key = g_mem_chunk_alloc (scsidev_req_keys);
-        COPY_ADDRESS (&(req_key->devid), &(pinfo->src));
+    if (!isreq && (cdata == NULL || !(cdata->flags & 0x3))) {
+        /*
+         * INQUIRY response; add device type to list of known devices &
+         * their types if not already known.
+         *
+         * XXX - this assumes that the source address of the INQUIRY
+         * reply uniquely identifies the device; that isn't the case, as,
+         * for example, for iSCSI you could have more than one target
+         * or LUN at a given IP address, and for NDMP more than one
+         * device can be opened and closed in the same session.
+         */
+        COPY_ADDRESS (&(dkey.devid), &(pinfo->src));
+        devdata = (scsi_devtype_data_t *)g_hash_table_lookup (scsidev_req_hash,
+                                                              &dkey);
+        if (!devdata) {
+            req_key = g_mem_chunk_alloc (scsidev_req_keys);
+            COPY_ADDRESS (&(req_key->devid), &(pinfo->src));
         
-        devdata = g_mem_chunk_alloc (scsidev_req_vals);
-        devdata->devtype = tvb_get_guint8 (tvb, offset) & 0x10;
+            devdata = g_mem_chunk_alloc (scsidev_req_vals);
+            devdata->devtype = tvb_get_guint8 (tvb, offset) & 0x3F;
         
-        g_hash_table_insert (scsidev_req_hash, req_key, devdata);
+            g_hash_table_insert (scsidev_req_hash, req_key, devdata);
+	}
     }
-        
+
     if (!tree)
         return;
     
@@ -1558,7 +1571,150 @@ dissect_scsi_logsense (tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree,
     }
 }
 
-static guint8
+static gboolean
+dissect_scsi_blockdescs (tvbuff_t *tvb, packet_info *pinfo _U_,
+                        proto_tree *scsi_tree, guint offset,
+                        guint payload_len, guint desclen,
+                        scsi_device_type devtype, gboolean longlba)
+{
+    while (desclen != 0) {
+        if (longlba) {
+            if (payload_len < 8)
+                return FALSE;
+            if (desclen < 8) {
+                offset += desclen;
+                payload_len -= desclen;
+                break;
+            }
+            proto_tree_add_text (scsi_tree, tvb, offset, 8, "No. of Blocks: %s",
+                                 u64toa (tvb_get_ptr (tvb, offset, 8)));
+            offset += 8;
+            payload_len -= 8;
+            desclen -= 8;
+
+            if (payload_len < 1)
+                return FALSE;
+            if (desclen < 1)
+                break;
+            proto_tree_add_text (scsi_tree, tvb, offset, 1, "Density Code: 0x%02x",
+                                 tvb_get_guint8 (tvb, offset));
+            offset += 1;
+            payload_len -= 1;
+            desclen -= 1;
+
+            if (payload_len < 3)
+                return FALSE;
+            if (desclen < 3) {
+                offset += desclen;
+                payload_len -= desclen;
+                break;
+            }
+            /* 3 reserved bytes */
+            offset += 3;
+            payload_len -= 3;
+            desclen -= 3;
+
+            if (payload_len < 4)
+                return FALSE;
+            if (desclen < 4) {
+                offset += desclen;
+                payload_len -= desclen;
+                break;
+            }
+            proto_tree_add_text (scsi_tree, tvb, offset, 4, "Block Length: %u",
+                                     tvb_get_ntohl (tvb, offset));
+            offset += 4;
+            payload_len -= 4;
+            desclen -= 4;
+        } else {
+            if (devtype == SCSI_DEV_SBC) {
+                if (payload_len < 4)
+                    return FALSE;
+                if (desclen < 4) {
+                    offset += desclen;
+                    payload_len -= desclen;
+                    break;
+                }
+                proto_tree_add_text (scsi_tree, tvb, offset, 4, "No. of Blocks: %u",
+                                     tvb_get_ntohl (tvb, offset));
+                offset += 4;
+                payload_len -= 4;
+                desclen -= 4;
+
+                if (payload_len < 1)
+                    return FALSE;
+                if (desclen < 1)
+                    break;
+                proto_tree_add_text (scsi_tree, tvb, offset, 1, "Density Code: 0x%02x",
+                                     tvb_get_guint8 (tvb, offset));
+                offset += 1;
+                payload_len -= 1;
+                desclen -= 1;
+
+                if (payload_len < 3)
+                    return FALSE;
+                if (desclen < 3) {
+                    offset += desclen;
+                    payload_len -= desclen;
+                    break;
+                }
+                proto_tree_add_text (scsi_tree, tvb, offset, 3, "Block Length: %u",
+                                         tvb_get_ntoh24 (tvb, offset));
+                offset += 3;
+                payload_len -= 3;
+                desclen -= 3;
+            } else {
+                if (payload_len < 1)
+                    return FALSE;
+                if (desclen < 1)
+                    break;
+                proto_tree_add_text (scsi_tree, tvb, offset, 1, "Density Code: 0x%02x",
+                                     tvb_get_guint8 (tvb, offset));
+                offset += 1;
+                payload_len -= 1;
+                desclen -= 1;
+
+                if (payload_len < 3)
+                    return FALSE;
+                if (desclen < 3) {
+                    offset += desclen;
+                    payload_len -= desclen;
+                    break;
+                }
+                proto_tree_add_text (scsi_tree, tvb, offset, 3, "No. of Blocks: %u",
+                                     tvb_get_ntoh24 (tvb, offset));
+                offset += 3;
+                payload_len -= 3;
+                desclen -= 3;
+
+                if (payload_len < 1)
+                    return FALSE;
+                if (desclen < 1)
+                    break;
+                /* Reserved byte */
+                offset += 1;
+                payload_len -= 1;
+                desclen -= 1;
+
+                if (payload_len < 3)
+                    return FALSE;
+                if (desclen < 3) {
+                    offset += desclen;
+                    payload_len -= desclen;
+                    break;
+                }
+                proto_tree_add_text (scsi_tree, tvb, offset, 3, "Block Length: %u",
+                                         tvb_get_ntoh24 (tvb, offset));
+                offset += 3;
+                payload_len -= 3;
+                desclen -= 3;
+            }
+        }
+    }
+    return TRUE;
+}
+
+static guint
 dissect_scsi_modepage (tvbuff_t *tvb, packet_info *pinfo _U_, 
 		       proto_tree *scsi_tree, guint offset)
 {
@@ -1826,7 +1982,7 @@ dissect_scsi_modepage (tvbuff_t *tvb, packet_info *pinfo _U_,
 static void
 dissect_scsi_modeselect6 (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
                           guint offset, gboolean isreq, gboolean iscdb,
-                          guint payload_len)
+                          scsi_device_type devtype, guint payload_len)
 {
     guint8 flags;
     guint tot_len, desclen, plen;
@@ -1891,34 +2047,12 @@ dissect_scsi_modeselect6 (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
         offset += 1;
         payload_len -= 1;
 
-        if (desclen) {
-            if (payload_len < 1)
-                return;
-            proto_tree_add_text (tree, tvb, offset, 1, "Density Code: 0x%02x",
-                                 tvb_get_guint8 (tvb, offset));
-            offset += 1;
-            payload_len -= 1;
-
-            if (payload_len < 3)
-                return;
-            proto_tree_add_text (tree, tvb, offset, 3, "No. of Blocks: %u",
-                                 tvb_get_ntoh24 (tvb, offset));
-            offset += 3;
-            payload_len -= 3;
-
-            if (payload_len < 1)
-                return;
-            /* Reserved byte */
-            offset += 1;
-            payload_len -= 1;
+        if (!dissect_scsi_blockdescs (tvb, pinfo, tree, offset, payload_len,
+                                     desclen, devtype, FALSE))
+            return;
+        offset += desclen;
+        payload_len -= desclen;
 
-            if (payload_len < 3)
-                return;
-            proto_tree_add_text (tree, tvb, offset, 3, "Block Length: %u",
-                                 tvb_get_ntoh24 (tvb, offset));
-            offset += 3;
-            payload_len -= 3;
-        }
         /* offset points to the start of the mode page */
         while ((payload_len > 0) && tvb_bytes_exist (tvb, offset, 2)) {
             plen = dissect_scsi_modepage (tvb, pinfo, tree, offset);
@@ -1931,7 +2065,7 @@ dissect_scsi_modeselect6 (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
 static void
 dissect_scsi_modeselect10 (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
                            guint offset, gboolean isreq, gboolean iscdb,
-                           guint payload_len)
+                           scsi_device_type devtype, guint payload_len)
 {
     guint8 flags;
     gboolean longlba;
@@ -2004,35 +2138,12 @@ dissect_scsi_modeselect10 (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
         offset += 1;
         payload_len -= 1;
 
-        if (desclen) {
-            /* XXX - does longlba affect this? */
-            if (payload_len < 1)
-                return;
-            proto_tree_add_text (tree, tvb, offset, 1, "Density Code: 0x%02x",
-                                 tvb_get_guint8 (tvb, offset));
-            offset += 1;
-            payload_len -= 1;
-
-            if (payload_len < 3)
-                return;
-            proto_tree_add_text (tree, tvb, offset, 3, "No. of Blocks: %u",
-                                 tvb_get_ntoh24 (tvb, offset));
-            offset += 3;
-            payload_len -= 3;
-
-            if (payload_len < 1)
-                return;
-            /* Reserved byte */
-            offset += 1;
-            payload_len -= 1;
+        if (!dissect_scsi_blockdescs (tvb, pinfo, tree, offset, payload_len,
+                                     desclen, devtype, longlba))
+            return;
+        offset += desclen;
+        payload_len -= desclen;
 
-            if (payload_len < 3)
-                return;
-            proto_tree_add_text (tree, tvb, offset, 3, "Block Length: %u",
-                                 tvb_get_ntoh24 (tvb, offset));
-            offset += 3;
-            payload_len -= 3;
-        }
         /* offset points to the start of the mode page */
         while ((payload_len > 0) && tvb_bytes_exist (tvb, offset, 2)) {
             plen = dissect_scsi_modepage (tvb, pinfo, tree, offset);
@@ -2045,7 +2156,7 @@ dissect_scsi_modeselect10 (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
 static void
 dissect_scsi_modesense6 (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
                          guint offset, gboolean isreq, gboolean iscdb,
-                         guint payload_len)
+                         scsi_device_type devtype, guint payload_len)
 {
     guint8 flags;
     guint tot_len, desclen, plen;
@@ -2117,34 +2228,12 @@ dissect_scsi_modesense6 (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
         offset += 1;
         tot_len -= 1;
 
-        if (desclen) {
-            if (tot_len < 1)
-                return;
-            proto_tree_add_text (tree, tvb, offset, 1, "Density Code: 0x%02x",
-                                 tvb_get_guint8 (tvb, offset));
-            offset += 1;
-            tot_len -= 1;
-
-            if (tot_len < 3)
-                return;
-            proto_tree_add_text (tree, tvb, offset, 3, "No. of Blocks: %u",
-                                 tvb_get_ntoh24 (tvb, offset));
-            offset += 3;
-            tot_len -= 3;
-
-            if (tot_len < 1)
-                return;
-            /* Reserved byte */
-            offset += 1;
-            tot_len -= 1;
+        if (!dissect_scsi_blockdescs (tvb, pinfo, tree, offset, tot_len,
+                                     desclen, devtype, FALSE))
+            return;
+        offset += desclen;
+        tot_len -= desclen;
 
-            if (tot_len < 3)
-                return;
-            proto_tree_add_text (tree, tvb, offset, 3, "Block Length: %u",
-                                 tvb_get_ntoh24 (tvb, offset));
-            offset += 3;
-            tot_len -= 3;
-        }
         /* offset points to the start of the mode page */
         while ((tot_len > 0) && tvb_bytes_exist (tvb, offset, 2)) {
             plen = dissect_scsi_modepage (tvb, pinfo, tree, offset);
@@ -2157,7 +2246,7 @@ dissect_scsi_modesense6 (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
 static void
 dissect_scsi_modesense10 (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
                           guint offset, gboolean isreq, gboolean iscdb,
-                          guint payload_len)
+                          scsi_device_type devtype, guint payload_len)
 {
     guint8 flags;
     gboolean longlba;
@@ -2237,35 +2326,12 @@ dissect_scsi_modesense10 (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
         offset += 1;
         tot_len -= 1;
 
-        if (desclen) {
-            /* XXX - does longlba affect this? */
-            if (tot_len < 1)
-                return;
-            proto_tree_add_text (tree, tvb, offset, 1, "Density Code: 0x%02x",
-                                 tvb_get_guint8 (tvb, offset));
-            offset += 1;
-            tot_len -= 1;
-
-            if (tot_len < 3)
-                return;
-            proto_tree_add_text (tree, tvb, offset, 3, "No. of Blocks: %u",
-                                 tvb_get_ntoh24 (tvb, offset));
-            offset += 3;
-            tot_len -= 3;
-
-            if (tot_len < 1)
-                return;
-            /* Reserved byte */
-            offset += 1;
-            tot_len -= 1;
+        if (!dissect_scsi_blockdescs (tvb, pinfo, tree, offset, tot_len,
+                                     desclen, devtype, longlba))
+            return;
+        offset += desclen;
+        tot_len -= desclen;
 
-            if (tot_len < 3)
-                return;
-            proto_tree_add_text (tree, tvb, offset, 3, "Block Length: %u",
-                                 tvb_get_ntoh24 (tvb, offset));
-            offset += 3;
-            tot_len -= 3;
-        }
         /* offset points to the start of the mode page */
         while ((tot_len > 0) && tvb_bytes_exist (tvb, offset, 2)) {
             plen = dissect_scsi_modepage (tvb, pinfo, tree, offset);
@@ -2579,7 +2645,7 @@ dissect_scsi_formatunit (tvbuff_t *tvb, packet_info *pinfo _U_,
 }
 
 static void
-dissect_scsi_rdwr6 (tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree,
+dissect_scsi_sbc2_rdwr6 (tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree,
                     guint offset, gboolean isreq, gboolean iscdb)
 {
     guint8 flags;
@@ -2603,6 +2669,57 @@ dissect_scsi_rdwr6 (tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree,
 }
 
 static void
+dissect_scsi_ssc2_read6 (tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree,
+                    guint offset, gboolean isreq, gboolean iscdb)
+{
+    guint8 flags;
+
+    if (isreq) {
+        if (check_col (pinfo->cinfo, COL_INFO))
+            col_append_fstr (pinfo->cinfo, COL_INFO, "(Len: %u)",
+                             tvb_get_ntoh24 (tvb, offset+1));
+    }
+    
+    if (tree && isreq && iscdb) {
+        flags = tvb_get_guint8 (tvb, offset);
+        proto_tree_add_text (tree, tvb, offset, 1,
+                             "SILI: %u, FIXED: %u",
+                             (flags & 0x02) >> 1, flags & 0x01);
+        proto_tree_add_item (tree, hf_scsi_rdwr6_xferlen, tvb, offset+1, 1, 0);
+        flags = tvb_get_guint8 (tvb, offset+4);
+        proto_tree_add_uint_format (tree, hf_scsi_control, tvb, offset+4, 1,
+                                    flags,
+                                    "Vendor Unique = %u, NACA = %u, Link = %u",
+                                    flags & 0xC0, flags & 0x4, flags & 0x1);
+    }
+}
+
+static void
+dissect_scsi_ssc2_write6 (tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree,
+                    guint offset, gboolean isreq, gboolean iscdb)
+{
+    guint8 flags;
+
+    if (isreq) {
+        if (check_col (pinfo->cinfo, COL_INFO))
+            col_append_fstr (pinfo->cinfo, COL_INFO, "(Len: %u)",
+                             tvb_get_ntoh24 (tvb, offset+1));
+    }
+    
+    if (tree && isreq && iscdb) {
+        flags = tvb_get_guint8 (tvb, offset);
+        proto_tree_add_text (tree, tvb, offset, 1,
+                             "FIXED: %u", flags & 0x01);
+        proto_tree_add_item (tree, hf_scsi_rdwr6_xferlen, tvb, offset+1, 1, 0);
+        flags = tvb_get_guint8 (tvb, offset+4);
+        proto_tree_add_uint_format (tree, hf_scsi_control, tvb, offset+4, 1,
+                                    flags,
+                                    "Vendor Unique = %u, NACA = %u, Link = %u",
+                                    flags & 0xC0, flags & 0x4, flags & 0x1);
+    }
+}
+
+static void
 dissect_scsi_rdwr10 (tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree,
                      guint offset, gboolean isreq, gboolean iscdb)
 {
@@ -2876,8 +2993,8 @@ dissect_scsi_cdb (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
     proto_item *ti;
     proto_tree *scsi_tree = NULL;
     guint8 opcode;
+    scsi_device_type devtype;
     scsi_cmnd_type cmd = 0;     /* 0 is undefined type */
-    scsi_device_type devtype = 0;
     gchar *valstr;
     scsi_task_data_t *cdata;
     scsi_devtype_key_t dkey;
@@ -2885,7 +3002,15 @@ dissect_scsi_cdb (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
     
     opcode = tvb_get_guint8 (tvb, offset);
 
-    /* Identify target if possible */
+    /*
+     * Try to look up the device data for this device.
+     *
+     * XXX - this assumes that the destination address of the request
+     * uniquely identifies the device; that isn't the case, as,
+     * for example, for iSCSI you could have more than one target
+     * or LUN at a given IP address, and for NDMP more than one
+     * device can be opened and closed in the same session.
+     */
     COPY_ADDRESS (&(dkey.devid), &pinfo->dst);
 
     devdata = (scsi_devtype_data_t *)g_hash_table_lookup (scsidev_req_hash,
@@ -2898,17 +3023,29 @@ dissect_scsi_cdb (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
     }
 
     if ((valstr = match_strval (opcode, scsi_spc2_val)) == NULL) {
-        if (devtype == SCSI_DEV_SBC) {
+        /*
+         * This isn't a generic command that applies to all SCSI
+         * device types; try to interpret it based on what we deduced,
+         * or were told, the device type is.
+         *
+         * Right now, the only choices are SBC or SSC. If we ever expand
+         * this to decode other device types, this piece of code needs to
+         * be modified.
+         */
+        switch (devtype) {
+        case SCSI_DEV_SBC:
             valstr = match_strval (opcode, scsi_sbc2_val);
             cmd = SCSI_CMND_SBC2;
-        }
-        else {
-            /* Right now, the only choices are SBC or SSC. If we ever expand
-             * this to decode other device types, this piece of code needs to
-             * be modified.
-             */
+            break;
+
+        case SCSI_DEV_SSC:
             valstr = match_strval (opcode, scsi_ssc2_val);
             cmd = SCSI_CMND_SSC2;
+            break;
+
+        default:
+            cmd = SCSI_CMND_SPC2;
+            break;
         }
     }
     else {
@@ -2930,7 +3067,8 @@ dissect_scsi_cdb (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
 
     if (cdata) {
         cdata->opcode = opcode;
-        cdata->devtype = cmd;
+        cdata->cmd = cmd;
+        cdata->devtype = devtype;
     }
     
     if (tree) {
@@ -2953,16 +3091,16 @@ dissect_scsi_cdb (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
                                             "Opcode: %s (0x%02x)", valstr,
                                             opcode);
             }
-            else {
-                 proto_tree_add_uint_format (scsi_tree, hf_scsi_sscopcode, tvb,
-                                             offset, 1,
-                                             tvb_get_guint8 (tvb, offset),
-                                             "Opcode: %s (0x%02x)", valstr,
-                                             opcode);
+            else if (cmd == SCSI_CMND_SSC2) {
+                proto_tree_add_uint_format (scsi_tree, hf_scsi_sscopcode, tvb,
+                                            offset, 1,
+                                            tvb_get_guint8 (tvb, offset),
+                                            "Opcode: %s (0x%02x)", valstr,
+                                            opcode);
             }
         }
         else {
-            proto_tree_add_item (scsi_tree, hf_scsi_sbcopcode, tvb, offset, 1, 0);
+            proto_tree_add_item (scsi_tree, hf_scsi_spcopcode, tvb, offset, 1, 0);
         }
     }
         
@@ -2990,22 +3128,22 @@ dissect_scsi_cdb (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
 
         case SCSI_SPC2_MODESELECT6:
             dissect_scsi_modeselect6 (tvb, pinfo, scsi_tree, offset+1,
-                                      TRUE, TRUE, 0);
+                                      TRUE, TRUE, devtype, 0);
             break;
 
         case SCSI_SPC2_MODESELECT10:
             dissect_scsi_modeselect10 (tvb, pinfo, scsi_tree, offset+1,
-                                       TRUE, TRUE, 0);
+                                       TRUE, TRUE, devtype, 0);
             break;
 
         case SCSI_SPC2_MODESENSE6:
             dissect_scsi_modesense6 (tvb, pinfo, scsi_tree, offset+1, TRUE,
-                                     TRUE, 0);
+                                     TRUE, devtype, 0);
             break;
 
         case SCSI_SPC2_MODESENSE10:
             dissect_scsi_modesense10 (tvb, pinfo, scsi_tree, offset+1,
-                                      TRUE, TRUE, 0);
+                                      TRUE, TRUE, devtype, 0);
             break;
 
         case SCSI_SPC2_PERSRESVIN:
@@ -3077,7 +3215,7 @@ dissect_scsi_cdb (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
             break;
 
         case SCSI_SBC2_READ6:
-            dissect_scsi_rdwr6 (tvb, pinfo, scsi_tree, offset+1, TRUE,
+            dissect_scsi_sbc2_rdwr6 (tvb, pinfo, scsi_tree, offset+1, TRUE,
                                 TRUE);
             break;
 
@@ -3117,7 +3255,7 @@ dissect_scsi_cdb (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
             break;
 
         case SCSI_SBC2_WRITE6:
-            dissect_scsi_rdwr6 (tvb, pinfo, scsi_tree, offset+1, TRUE,
+            dissect_scsi_sbc2_rdwr6 (tvb, pinfo, scsi_tree, offset+1, TRUE,
                                 TRUE);
             break;
 
@@ -3142,23 +3280,36 @@ dissect_scsi_cdb (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
         }
     }
     else if (cmd == SCSI_CMND_SSC2) {
+        switch (opcode) {
+
+        case SCSI_SSC2_READ6:
+            dissect_scsi_ssc2_read6 (tvb, pinfo, scsi_tree, offset+1, TRUE,
+                                TRUE);
+            break;
+
+        case SCSI_SSC2_WRITE6:
+            dissect_scsi_ssc2_write6 (tvb, pinfo, scsi_tree, offset+1, TRUE,
+                                TRUE);
+            break;
+
+        default:
+            call_dissector (data_handle, tvb, pinfo, scsi_tree);
+            break;
+        }
+    } else {
         call_dissector (data_handle, tvb, pinfo, scsi_tree);
     }
 }
 
-static void
-dissect_scsi (tvbuff_t *tvb _U_, packet_info *pinfo _U_, proto_tree *tree _U_)
-{
-}
-
 void
 dissect_scsi_payload (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
                       guint offset, gboolean isreq, guint32 payload_len)
 {
     proto_item *ti;
-    proto_tree *scsi_tree;
+    proto_tree *scsi_tree = NULL;
     guint8 opcode = 0xFF;
     scsi_cmnd_type cmd = 0;     /* 0 is undefined type */
+    scsi_device_type devtype;
     scsi_task_data_t *cdata = NULL;
     
     cdata = scsi_find_task (pinfo);
@@ -3171,7 +3322,8 @@ dissect_scsi_payload (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
     }
 
     opcode = cdata->opcode;
-    cmd = cdata->devtype;
+    cmd = cdata->cmd;
+    devtype = cdata->devtype;
     
     if (tree) {
         if (cmd == SCSI_CMND_SPC2) {
@@ -3192,6 +3344,15 @@ dissect_scsi_payload (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
                                                              "0x%02x"),
                                                  isreq ? "Request" : "Response");
         }
+        else if (cmd == SCSI_CMND_SSC2) {
+            ti = proto_tree_add_protocol_format (tree, proto_scsi, tvb, offset,
+                                                 payload_len,
+                                                 "SCSI Payload (%s %s)",
+                                                 val_to_str (opcode,
+                                                             scsi_ssc2_val,
+                                                             "0x%02x"),
+                                                 isreq ? "Request" : "Response");
+        }
         else {
             ti = proto_tree_add_protocol_format (tree, proto_scsi, tvb, offset,
                                                  payload_len,
@@ -3201,7 +3362,21 @@ dissect_scsi_payload (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
         }
 
         scsi_tree = proto_item_add_subtree (ti, ett_scsi);
+    }
 
+    if (tree == NULL) {
+        /*
+         * We have to dissect INQUIRY responses, in order to determine the
+         * types of devices.
+         *
+         * We don't bother dissecting other payload if we're not buildng
+         * a protocol tree.
+         */
+        if (cmd == SCSI_CMND_SPC2 && opcode == SCSI_SPC2_INQUIRY) {
+            dissect_scsi_inquiry (tvb, pinfo, scsi_tree, offset, isreq,
+                                  FALSE, payload_len, cdata);
+        }
+      } else {
         if (cmd == SCSI_CMND_SPC2) {
             switch (opcode) {
             case SCSI_SPC2_INQUIRY:
@@ -3226,22 +3401,22 @@ dissect_scsi_payload (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
 
             case SCSI_SPC2_MODESELECT6:
                 dissect_scsi_modeselect6 (tvb, pinfo, scsi_tree, offset,
-                                          isreq, FALSE, payload_len);
+                                          isreq, FALSE, devtype, payload_len);
                 break;
 
             case SCSI_SPC2_MODESELECT10:
                 dissect_scsi_modeselect10 (tvb, pinfo, scsi_tree, offset,
-                                           isreq, FALSE, payload_len);
+                                           isreq, FALSE, devtype, payload_len);
                 break;
 
             case SCSI_SPC2_MODESENSE6:
                 dissect_scsi_modesense6 (tvb, pinfo, scsi_tree, offset, isreq,
-                                         FALSE, payload_len);
+                                         FALSE, devtype, payload_len);
                 break;
 
             case SCSI_SPC2_MODESENSE10:
                 dissect_scsi_modesense10 (tvb, pinfo, scsi_tree, offset,
-                                          isreq, FALSE, payload_len);
+                                          isreq, FALSE, devtype, payload_len);
                 break;
 
             case SCSI_SPC2_PERSRESVIN:
@@ -3308,7 +3483,7 @@ dissect_scsi_payload (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
                 break;
 
             case SCSI_SBC2_READ6:
-                dissect_scsi_rdwr6 (tvb, pinfo, scsi_tree, offset, isreq,
+                dissect_scsi_sbc2_rdwr6 (tvb, pinfo, scsi_tree, offset, isreq,
                                     FALSE);
                 break;
 
@@ -3348,7 +3523,7 @@ dissect_scsi_payload (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
                 break;
 
             case SCSI_SBC2_WRITE6:
-                dissect_scsi_rdwr6 (tvb, pinfo, scsi_tree, offset, isreq,
+                dissect_scsi_sbc2_rdwr6 (tvb, pinfo, scsi_tree, offset, isreq,
                                     FALSE);
                 break;
 
@@ -3372,6 +3547,24 @@ dissect_scsi_payload (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
                 break;
             }
         }
+        else if (cmd == SCSI_CMND_SSC2) {
+            switch (opcode) {
+
+            case SCSI_SSC2_READ6:
+                dissect_scsi_ssc2_read6 (tvb, pinfo, scsi_tree, offset, isreq,
+                                    FALSE);
+                break;
+
+            case SCSI_SSC2_WRITE6:
+                dissect_scsi_ssc2_write6 (tvb, pinfo, scsi_tree, offset, isreq,
+                                FALSE);
+                break;
+
+            default:
+                call_dissector (data_handle, tvb, pinfo, scsi_tree);
+                break;
+            }
+        }
         else {
             call_dissector (data_handle, tvb, pinfo, scsi_tree);
         }
@@ -3477,7 +3670,7 @@ proto_register_scsi (void)
           {"Logical Block Address (LBA)", "scsi.rdwr6.lba", FT_UINT24, BASE_DEC,
            NULL, 0x0FFFFF, "", HFILL}},
         { &hf_scsi_rdwr6_xferlen,
-          {"Transfer Length", "scsi.rdwr6.xferlen", FT_UINT8, BASE_DEC, NULL, 0x0,
+          {"Transfer Length", "scsi.rdwr6.xferlen", FT_UINT24, BASE_DEC, NULL, 0x0,
            "", HFILL}},
         { &hf_scsi_rdwr10_lba,
           {"Logical Block Address (LBA)", "scsi.rdwr10.lba", FT_UINT32, BASE_DEC,
@@ -3600,7 +3793,6 @@ proto_register_scsi (void)
     proto_register_field_array(proto_scsi, hf, array_length(hf));
     proto_register_subtree_array(ett, array_length(ett));
     register_init_routine (&scsi_init_protocol);
-    register_dissector ("SCSI", dissect_scsi, proto_scsi);
     data_handle = find_dissector ("data");
 
     /* add preferences to decode SCSI message */