USB MSC BOT: Move CBW and CSW dissection to functions

Move CBW and CSW dissection to separate functions to make it possible to
reuse the CBW/CSW dissecting code later. No functional changes.

1 files changed, 131 insertions, 114 deletions

diff --git a/epan/dissectors/packet-usbms-bot.c b/epan/dissectors/packet-usbms-bot.c
index d526906224..6496e39b0d 100644
--- a/epan/dissectors/packet-usbms-bot.c
+++ b/epan/dissectors/packet-usbms-bot.c
@@ -164,6 +164,135 @@ dissect_usbms_bot_control(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_
     return tvb_captured_length(tvb);
 }
 
+static int
+dissect_usbms_bot_cbw(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, proto_tree *tree, usbms_bot_conv_info_t *usbms_bot_conv_info)
+{
+    tvbuff_t *cdb_tvb;
+    int offset=0;
+    int cdbrlen, cdblen;
+    guint8 lun, flags;
+    guint32 datalen;
+    itl_nexus_t *itl;
+    itlq_nexus_t *itlq;
+
+    /* dCBWSignature */
+    proto_tree_add_item(tree, hf_usbms_bot_dCBWSignature, tvb, offset, 4, ENC_LITTLE_ENDIAN);
+    offset+=4;
+
+    /* dCBWTag */
+    proto_tree_add_item(tree, hf_usbms_bot_dCBWTag, tvb, offset, 4, ENC_LITTLE_ENDIAN);
+    offset+=4;
+
+    /* dCBWDataTransferLength */
+    proto_tree_add_item(tree, hf_usbms_bot_dCBWDataTransferLength, tvb, offset, 4, ENC_LITTLE_ENDIAN);
+    datalen=tvb_get_letohl(tvb, offset);
+    offset+=4;
+
+    /* dCBWFlags */
+    proto_tree_add_item(tree, hf_usbms_bot_dCBWFlags, tvb, offset, 1, ENC_LITTLE_ENDIAN);
+    flags=tvb_get_guint8(tvb, offset);
+    offset+=1;
+
+    /* dCBWLUN */
+    proto_tree_add_item(tree, hf_usbms_bot_dCBWTarget, tvb, offset, 1, ENC_LITTLE_ENDIAN);
+    proto_tree_add_item(tree, hf_usbms_bot_dCBWLUN, tvb, offset, 1, ENC_LITTLE_ENDIAN);
+    lun=tvb_get_guint8(tvb, offset)&0x0f;
+    offset+=1;
+
+    /* make sure we have a ITL structure for this LUN */
+    itl=(itl_nexus_t *)wmem_tree_lookup32(usbms_bot_conv_info->itl, lun);
+    if(!itl){
+        itl=wmem_new(wmem_file_scope(), itl_nexus_t);
+        itl->cmdset=0xff;
+        itl->conversation=NULL;
+        wmem_tree_insert32(usbms_bot_conv_info->itl, lun, itl);
+    }
+
+    /* make sure we have an ITLQ structure for this LUN/transaction */
+    itlq=(itlq_nexus_t *)wmem_tree_lookup32(usbms_bot_conv_info->itlq, pinfo->num);
+    if(!itlq){
+        itlq=wmem_new(wmem_file_scope(), itlq_nexus_t);
+        itlq->lun=lun;
+        itlq->scsi_opcode=0xffff;
+        itlq->task_flags=0;
+        if(datalen){
+            if(flags&0x80){
+                itlq->task_flags|=SCSI_DATA_READ;
+            } else {
+                itlq->task_flags|=SCSI_DATA_WRITE;
+            }
+        }
+        itlq->data_length=datalen;
+        itlq->bidir_data_length=0;
+        itlq->fc_time=pinfo->abs_ts;
+        itlq->first_exchange_frame=pinfo->num;
+        itlq->last_exchange_frame=0;
+        itlq->flags=0;
+        itlq->alloc_len=0;
+        itlq->extra_data=NULL;
+        wmem_tree_insert32(usbms_bot_conv_info->itlq, pinfo->num, itlq);
+    }
+
+    /* dCBWCBLength */
+    proto_tree_add_item(tree, hf_usbms_bot_dCBWCBLength, tvb, offset, 1, ENC_LITTLE_ENDIAN);
+    cdbrlen=tvb_get_guint8(tvb, offset)&0x1f;
+    offset+=1;
+
+    cdblen=cdbrlen;
+    if(cdblen>tvb_captured_length_remaining(tvb, offset)){
+        cdblen=tvb_captured_length_remaining(tvb, offset);
+    }
+    if(cdblen){
+        cdb_tvb=tvb_new_subset_length_caplen(tvb, offset, cdblen, cdbrlen);
+        dissect_scsi_cdb(cdb_tvb, pinfo, parent_tree, SCSI_DEV_UNKNOWN, itlq, itl);
+    }
+    return tvb_captured_length(tvb);
+}
+
+static int
+dissect_usbms_bot_csw(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, proto_tree *tree, usbms_bot_conv_info_t *usbms_bot_conv_info)
+{
+    int offset=0;
+    guint8 status;
+    itl_nexus_t *itl;
+    itlq_nexus_t *itlq;
+
+    /* dCSWSignature */
+    proto_tree_add_item(tree, hf_usbms_bot_dCSWSignature, tvb, offset, 4, ENC_LITTLE_ENDIAN);
+    offset+=4;
+
+    /* dCSWTag */
+    proto_tree_add_item(tree, hf_usbms_bot_dCBWTag, tvb, offset, 4, ENC_LITTLE_ENDIAN);
+    offset+=4;
+
+    /* dCSWDataResidue */
+    proto_tree_add_item(tree, hf_usbms_bot_dCSWDataResidue, tvb, offset, 4, ENC_LITTLE_ENDIAN);
+    offset+=4;
+
+    /* dCSWStatus */
+    proto_tree_add_item(tree, hf_usbms_bot_dCSWStatus, tvb, offset, 1, ENC_LITTLE_ENDIAN);
+    status=tvb_get_guint8(tvb, offset);
+    /*offset+=1;*/
+
+    itlq=(itlq_nexus_t *)wmem_tree_lookup32_le(usbms_bot_conv_info->itlq, pinfo->num);
+    if(!itlq){
+        return tvb_captured_length(tvb);
+    }
+    itlq->last_exchange_frame=pinfo->num;
+
+    itl=(itl_nexus_t *)wmem_tree_lookup32(usbms_bot_conv_info->itl, itlq->lun);
+    if(!itl){
+        return tvb_captured_length(tvb);
+    }
+
+    if(!status){
+        dissect_scsi_rsp(tvb, pinfo, parent_tree, itlq, itl, 0);
+    } else {
+        /* just send "check condition" */
+        dissect_scsi_rsp(tvb, pinfo, parent_tree, itlq, itl, 0x02);
+    }
+    return tvb_captured_length(tvb);
+}
 
 /* dissector for mass storage bulk data */
 static int
@@ -214,83 +343,7 @@ dissect_usbms_bot_bulk(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tre
      * SCSI CDB inside CBW
      */
     if(is_request&&(signature==0x43425355)&&(tvb_reported_length(tvb)==31)){
-        tvbuff_t *cdb_tvb;
-        int cdbrlen, cdblen;
-        guint8 lun, flags;
-        guint32 datalen;
-
-        /* dCBWSignature */
-        proto_tree_add_item(tree, hf_usbms_bot_dCBWSignature, tvb, offset, 4, ENC_LITTLE_ENDIAN);
-        offset+=4;
-
-        /* dCBWTag */
-        proto_tree_add_item(tree, hf_usbms_bot_dCBWTag, tvb, offset, 4, ENC_LITTLE_ENDIAN);
-        offset+=4;
-
-        /* dCBWDataTransferLength */
-        proto_tree_add_item(tree, hf_usbms_bot_dCBWDataTransferLength, tvb, offset, 4, ENC_LITTLE_ENDIAN);
-        datalen=tvb_get_letohl(tvb, offset);
-        offset+=4;
-
-        /* dCBWFlags */
-        proto_tree_add_item(tree, hf_usbms_bot_dCBWFlags, tvb, offset, 1, ENC_LITTLE_ENDIAN);
-        flags=tvb_get_guint8(tvb, offset);
-        offset+=1;
-
-        /* dCBWLUN */
-        proto_tree_add_item(tree, hf_usbms_bot_dCBWTarget, tvb, offset, 1, ENC_LITTLE_ENDIAN);
-        proto_tree_add_item(tree, hf_usbms_bot_dCBWLUN, tvb, offset, 1, ENC_LITTLE_ENDIAN);
-        lun=tvb_get_guint8(tvb, offset)&0x0f;
-        offset+=1;
-
-        /* make sure we have a ITL structure for this LUN */
-        itl=(itl_nexus_t *)wmem_tree_lookup32(usbms_bot_conv_info->itl, lun);
-        if(!itl){
-            itl=wmem_new(wmem_file_scope(), itl_nexus_t);
-            itl->cmdset=0xff;
-            itl->conversation=NULL;
-            wmem_tree_insert32(usbms_bot_conv_info->itl, lun, itl);
-        }
-
-        /* make sure we have an ITLQ structure for this LUN/transaction */
-        itlq=(itlq_nexus_t *)wmem_tree_lookup32(usbms_bot_conv_info->itlq, pinfo->num);
-        if(!itlq){
-            itlq=wmem_new(wmem_file_scope(), itlq_nexus_t);
-            itlq->lun=lun;
-            itlq->scsi_opcode=0xffff;
-            itlq->task_flags=0;
-            if(datalen){
-                if(flags&0x80){
-                    itlq->task_flags|=SCSI_DATA_READ;
-                } else {
-                    itlq->task_flags|=SCSI_DATA_WRITE;
-                }
-            }
-            itlq->data_length=datalen;
-            itlq->bidir_data_length=0;
-            itlq->fc_time=pinfo->abs_ts;
-            itlq->first_exchange_frame=pinfo->num;
-            itlq->last_exchange_frame=0;
-            itlq->flags=0;
-            itlq->alloc_len=0;
-            itlq->extra_data=NULL;
-            wmem_tree_insert32(usbms_bot_conv_info->itlq, pinfo->num, itlq);
-        }
-
-        /* dCBWCBLength */
-        proto_tree_add_item(tree, hf_usbms_bot_dCBWCBLength, tvb, offset, 1, ENC_LITTLE_ENDIAN);
-        cdbrlen=tvb_get_guint8(tvb, offset)&0x1f;
-        offset+=1;
-
-        cdblen=cdbrlen;
-        if(cdblen>tvb_captured_length_remaining(tvb, offset)){
-            cdblen=tvb_captured_length_remaining(tvb, offset);
-        }
-        if(cdblen){
-            cdb_tvb=tvb_new_subset_length_caplen(tvb, offset, cdblen, cdbrlen);
-            dissect_scsi_cdb(cdb_tvb, pinfo, parent_tree, SCSI_DEV_UNKNOWN, itlq, itl);
-        }
-        return tvb_captured_length(tvb);
+        return dissect_usbms_bot_cbw(tvb, pinfo, parent_tree, tree, usbms_bot_conv_info);
     }
 
 
@@ -298,43 +351,7 @@ dissect_usbms_bot_bulk(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tre
      * SCSI RESPONSE inside CSW
      */
     if((!is_request)&&(signature==0x53425355)&&(tvb_reported_length(tvb)==13)){
-        guint8 status;
-
-        /* dCSWSignature */
-        proto_tree_add_item(tree, hf_usbms_bot_dCSWSignature, tvb, offset, 4, ENC_LITTLE_ENDIAN);
-        offset+=4;
-
-        /* dCSWTag */
-        proto_tree_add_item(tree, hf_usbms_bot_dCBWTag, tvb, offset, 4, ENC_LITTLE_ENDIAN);
-        offset+=4;
-
-        /* dCSWDataResidue */
-        proto_tree_add_item(tree, hf_usbms_bot_dCSWDataResidue, tvb, offset, 4, ENC_LITTLE_ENDIAN);
-        offset+=4;
-
-        /* dCSWStatus */
-        proto_tree_add_item(tree, hf_usbms_bot_dCSWStatus, tvb, offset, 1, ENC_LITTLE_ENDIAN);
-        status=tvb_get_guint8(tvb, offset);
-        /*offset+=1;*/
-
-        itlq=(itlq_nexus_t *)wmem_tree_lookup32_le(usbms_bot_conv_info->itlq, pinfo->num);
-        if(!itlq){
-            return tvb_captured_length(tvb);
-        }
-        itlq->last_exchange_frame=pinfo->num;
-
-        itl=(itl_nexus_t *)wmem_tree_lookup32(usbms_bot_conv_info->itl, itlq->lun);
-        if(!itl){
-            return tvb_captured_length(tvb);
-        }
-
-        if(!status){
-            dissect_scsi_rsp(tvb, pinfo, parent_tree, itlq, itl, 0);
-        } else {
-            /* just send "check condition" */
-            dissect_scsi_rsp(tvb, pinfo, parent_tree, itlq, itl, 0x02);
-        }
-        return tvb_captured_length(tvb);
+        return dissect_usbms_bot_csw(tvb, pinfo, parent_tree, tree, usbms_bot_conv_info);
     }
 
     /*