now when we do dissect the descriptors:

add tracking so that when we find an interface descriptor which tells us the device class we also create a conversation for each and every endpoint for that interface and also let all conversations (one for each endpoint) share the same usb conversation info structure.


store the device type inside this conv_info structure


add the required code to manage BULK data pdus and have it for now only display what kind of bulk data is contained (interface class as snooped from the descriptors)



we now only need a class dissector table we can fork off into from the bulk dissector in usb    and then an external usb_masstorage dissector that registers itself as a mass storage device and we should be all set to dissect the scsi layer being transported atop usb





svn path=/trunk/; revision=19575

1 files changed, 121 insertions, 2 deletions

diff --git a/epan/dissectors/packet-usb.c b/epan/dissectors/packet-usb.c
index f2a412837f..064b7774de 100644
--- a/epan/dissectors/packet-usb.c
+++ b/epan/dissectors/packet-usb.c
@@ -106,6 +106,7 @@ static gint ett_descriptor_device = -1;
 
 /* there is one such structure for each device/endpoint conversation */
 typedef struct _usb_conv_info_t {
+    guint16 class;		/* class for this conversation */
     emem_tree_t *transactions;
 } usb_conv_info_t;
 
@@ -121,6 +122,17 @@ typedef struct _usb_trans_info_t {
             guint8 index;
         } get_descriptor;
     };
+
+
+    /* used to pass the interface class from the
+     * interface descriptor onto the endpoint
+     * descriptors so that we can create a
+     * conversation with the appropriate class
+     * once we know the endpoint.
+     */
+    usb_conv_info_t *interface_info;
+
+
 } usb_trans_info_t;
 
 typedef enum { 
@@ -157,12 +169,14 @@ static const value_string usb_langid_vals[] = {
     {0, NULL}
 };
 
+#define IF_CLASS_UNKNOWN		0xffff
 #define IF_CLASS_MASSTORAGE		0x08
 static const value_string usb_interfaceclass_vals[] = {
     {IF_CLASS_MASSTORAGE,	"Mass Storage Class"},
     {0, NULL}
 };
 
+
 static const value_string usb_urb_type_vals[] = {
     {URB_CONTROL_INPUT, "URB_CONTROL_INPUT"},
     {URB_CONTROL_OUTPUT,"URB_CONTROL_OUTPUT"},
@@ -197,6 +211,25 @@ static const value_string descriptor_type_vals[] = {
 };
 
 
+static usb_conv_info_t *
+get_usb_conv_info(conversation_t *conversation)
+{
+    usb_conv_info_t *usb_conv_info;
+
+    /* do we have conversation specific data ? */
+    usb_conv_info = conversation_get_proto_data(conversation, proto_usb);
+    if(!usb_conv_info){
+        /* no not yet so create some */
+        usb_conv_info = se_alloc(sizeof(usb_conv_info_t));
+        usb_conv_info->class=IF_CLASS_UNKNOWN;
+        usb_conv_info->transactions=se_tree_create_non_persistent(EMEM_TREE_TYPE_RED_BLACK, "usb transactions");
+
+        conversation_add_proto_data(conversation, proto_usb, usb_conv_info);
+    }
+ 
+    return usb_conv_info;
+}  
+
 static conversation_t *
 get_usb_conversation(packet_info *pinfo, guint32 src_endpoint, guint32 dst_endpoint)
 {
@@ -412,7 +445,7 @@ dissect_usb_string_descriptor(packet_info *pinfo _U_, proto_tree *parent_tree, t
 
 /* 9.6.5 */
 static int
-dissect_usb_interface_descriptor(packet_info *pinfo _U_, proto_tree *parent_tree, tvbuff_t *tvb, int offset, usb_trans_info_t *usb_trans_info _U_)
+dissect_usb_interface_descriptor(packet_info *pinfo, proto_tree *parent_tree, tvbuff_t *tvb, int offset, usb_trans_info_t *usb_trans_info _U_)
 {
     proto_item *item=NULL;
     proto_tree *tree=NULL;
@@ -445,6 +478,12 @@ dissect_usb_interface_descriptor(packet_info *pinfo _U_, proto_tree *parent_tree
 
     /* bInterfaceClass */
     proto_tree_add_item(tree, hf_usb_bInterfaceClass, tvb, offset, 1, TRUE);
+    /* save the class so we can access it later in the endpoint descriptor */
+    if(!pinfo->fd->flags.visited){
+        usb_trans_info->interface_info=se_alloc(sizeof(usb_conv_info_t));
+        usb_trans_info->interface_info->class=tvb_get_guint8(tvb, offset);
+        usb_trans_info->interface_info->transactions=se_tree_create_non_persistent(EMEM_TREE_TYPE_RED_BLACK, "usb transactions");
+    }
     offset++;
 
     /* bInterfaceSubClass */
@@ -468,11 +507,12 @@ dissect_usb_interface_descriptor(packet_info *pinfo _U_, proto_tree *parent_tree
 
 /* 9.6.6 */
 static int
-dissect_usb_endpoint_descriptor(packet_info *pinfo _U_, proto_tree *parent_tree, tvbuff_t *tvb, int offset, usb_trans_info_t *usb_trans_info _U_)
+dissect_usb_endpoint_descriptor(packet_info *pinfo, proto_tree *parent_tree, tvbuff_t *tvb, int offset, usb_trans_info_t *usb_trans_info _U_)
 {
     proto_item *item=NULL;
     proto_tree *tree=NULL;
     int old_offset=offset;
+    guint8 endpoint;
 
     if(parent_tree){
         item=proto_tree_add_text(parent_tree, tvb, offset, 0, "ENDPOINT DESCRIPTOR");
@@ -489,8 +529,29 @@ dissect_usb_endpoint_descriptor(packet_info *pinfo _U_, proto_tree *parent_tree,
 
     /* bEndpointAddress */
     proto_tree_add_item(tree, hf_usb_bEndpointAddress, tvb, offset, 1, TRUE);
+    endpoint=tvb_get_guint8(tvb, offset)&0x0f;
     offset++;
 
+    /* Together with class from the interface descriptor we know what kind
+     * of class the device at endpoint is.
+     * Make sure a conversation exists for this endpoint and attach a 
+     * usb_conv_into_t structure to it.
+     *
+     * All endpoints for the same interface descriptor share the same
+     * usb_conv_info structure.
+     */
+    if((!pinfo->fd->flags.visited)&&usb_trans_info->interface_info){
+        conversation_t *conversation;
+
+        if(pinfo->destport==NO_ENDPOINT){
+            conversation=get_usb_conversation(pinfo, endpoint, pinfo->destport);
+        } else {
+            conversation=get_usb_conversation(pinfo, pinfo->srcport, endpoint);
+        }
+
+        conversation_add_proto_data(conversation, proto_usb, usb_trans_info->interface_info);
+    }
+
     /* bmAttributes */
     proto_tree_add_item(tree, hf_usb_bmAttributes, tvb, offset, 1, TRUE);
     offset++;
@@ -557,6 +618,9 @@ dissect_usb_configuration_descriptor(packet_info *pinfo _U_, proto_tree *parent_
     proto_tree_add_item(tree, hf_usb_bMaxPower, tvb, offset, 1, TRUE);
     offset++;
 
+    /* initialize interface_info to NULL */
+    usb_trans_info->interface_info=NULL;
+
     /* decode any additional interface and endpoint descriptors */
     while(len>(old_offset-offset)){
         guint8 next_type;
@@ -759,6 +823,42 @@ dissect_usb(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent)
 
     /* set up addresses and ports */
     switch(type){
+    case URB_BULK_INPUT:
+        /* Bulk input are responses if they contain payload data and
+         * requests otherwise.
+         */
+        if(tvb_length_remaining(tvb, offset)>0){
+            src_addr=tmp_addr;
+            src_port=endpoint;
+            dst_addr=0xffffffff;
+            dst_port=NO_ENDPOINT;
+            is_request=FALSE;
+        } else {
+            src_addr=0xffffffff;
+            src_port=NO_ENDPOINT;
+            dst_addr=tmp_addr;
+            dst_port=endpoint;
+            is_request=TRUE;
+        }
+        break;
+    case URB_BULK_OUTPUT:
+        /* Bulk output are requests if they contain payload data and
+         * responses otherwise.
+         */
+        if(tvb_length_remaining(tvb, offset)>0){
+            src_addr=0xffffffff;
+            src_port=NO_ENDPOINT;
+            dst_addr=tmp_addr;
+            dst_port=endpoint;
+            is_request=TRUE;
+        } else {
+            src_addr=tmp_addr;
+            src_port=endpoint;
+            dst_addr=0xffffffff;
+            dst_port=NO_ENDPOINT;
+            is_request=FALSE;
+        }
+        break;
     case URB_CONTROL_INPUT:
         /* CONTROL INPUT packets are requests if they contain a "setup"
          * blob and responses othervise
@@ -796,11 +896,14 @@ dissect_usb(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent)
 
     conversation=get_usb_conversation(pinfo, pinfo->srcport, pinfo->destport);
 
+    usb_conv_info=get_usb_conv_info(conversation);
+
     /* do we have conversation specific data ? */
     usb_conv_info = conversation_get_proto_data(conversation, proto_usb);
     if(!usb_conv_info){
         /* no not yet so create some */
         usb_conv_info = se_alloc(sizeof(usb_conv_info_t));
+        usb_conv_info->class=IF_CLASS_UNKNOWN;
         usb_conv_info->transactions=se_tree_create_non_persistent(EMEM_TREE_TYPE_RED_BLACK, "usb transactions");
 
         conversation_add_proto_data(conversation, proto_usb, usb_conv_info);
@@ -811,6 +914,22 @@ dissect_usb(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent)
 
 
     switch(type){
+    case URB_BULK_INPUT:
+        {
+        proto_item *item;
+
+        item=proto_tree_add_uint(tree, hf_usb_bInterfaceClass, tvb, offset, 1, usb_conv_info->class);
+        PROTO_ITEM_SET_GENERATED(item);
+        }
+        break;
+    case URB_BULK_OUTPUT:
+        {
+        proto_item *item;
+
+        item=proto_tree_add_uint(tree, hf_usb_bInterfaceClass, tvb, offset, 1, usb_conv_info->class);
+        PROTO_ITEM_SET_GENERATED(item);
+        }
+        break;
     case URB_CONTROL_INPUT:
         {
         const usb_setup_dissector_table_t *tmp;