Make class "type" for USB conversations.

USB dissectors can't assume that only their class type has been passed around in the conversation.  Make explicit check that class type expected matches the dissector and stop/prevent dissection if there isn't a match.

Bug: 12356
Change-Id: Ib23973a4ebd0fbb51952ffc118daf95e3389a209
Reviewed-on: https://code.wireshark.org/review/15212
Petri-Dish: Michael Mann <mmann78@netscape.net>
Reviewed-by: Martin Kaiser <wireshark@kaiser.cx>
Petri-Dish: Martin Kaiser <wireshark@kaiser.cx>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Michael Mann <mmann78@netscape.net>

5 files changed, 20 insertions, 2 deletions

diff --git a/epan/dissectors/packet-u3v.c b/epan/dissectors/packet-u3v.c
index 3359766a74..8e1a979edd 100644
--- a/epan/dissectors/packet-u3v.c
+++ b/epan/dissectors/packet-u3v.c
@@ -1683,6 +1683,10 @@ dissect_u3v(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data)
     if (!u3v_conv_info) {
         u3v_conv_info = wmem_new0(wmem_file_scope(), u3v_conv_info_t);
         usb_conv_info->class_data = u3v_conv_info;
+        usb_conv_info->class_data_type = USB_CONV_U3V;
+    } else if (usb_conv_info->class_data_type != USB_CONV_U3V) {
+        /* Don't dissect if another USB type is in the conversation */
+        return 0;
     }
 
     prefix = tvb_get_letohl(tvb, 0);
diff --git a/epan/dissectors/packet-usb-audio.c b/epan/dissectors/packet-usb-audio.c
index 90c8e74aa3..df6e9ef7df 100644
--- a/epan/dissectors/packet-usb-audio.c
+++ b/epan/dissectors/packet-usb-audio.c
@@ -435,8 +435,12 @@ dissect_ac_if_hdr_body(tvbuff_t *tvb, gint offset, packet_info *pinfo _U_,
     if(!audio_conv_info) {
         audio_conv_info = wmem_new(wmem_file_scope(), audio_conv_info_t);
         usb_conv_info->class_data = audio_conv_info;
+        usb_conv_info->class_data_type = USB_CONV_AUDIO;
         /* XXX - set reasonable default values for all components
            that are not filled in by this function */
+    } else if (usb_conv_info->class_data_type != USB_CONV_AUDIO) {
+        /* Don't dissect if another USB type is in the conversation */
+        return 0;
     }
     audio_conv_info->ver_major = ver_major;
     offset += 2;
diff --git a/epan/dissectors/packet-usb-masstorage.c b/epan/dissectors/packet-usb-masstorage.c
index 743775be72..919f7ef364 100644
--- a/epan/dissectors/packet-usb-masstorage.c
+++ b/epan/dissectors/packet-usb-masstorage.c
@@ -199,9 +199,12 @@ dissect_usb_ms_bulk(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree,
         usb_ms_conv_info->itl=wmem_tree_new(wmem_file_scope());
         usb_ms_conv_info->itlq=wmem_tree_new(wmem_file_scope());
         usb_conv_info->class_data=usb_ms_conv_info;
+        usb_conv_info->class_data_type = USB_CONV_MASS_STORAGE;
+    } else if (usb_conv_info->class_data_type != USB_CONV_MASS_STORAGE) {
+        /* Don't dissect if another USB type is in the conversation */
+        return 0;
     }
 
-
     is_request=(pinfo->srcport==NO_ENDPOINT);
 
     col_set_str(pinfo->cinfo, COL_PROTOCOL, "USBMS");
diff --git a/epan/dissectors/packet-usb-video.c b/epan/dissectors/packet-usb-video.c
index 0bc292000f..3bf08f6156 100644
--- a/epan/dissectors/packet-usb-video.c
+++ b/epan/dissectors/packet-usb-video.c
@@ -1035,6 +1035,10 @@ dissect_usb_video_control_interface_descriptor(proto_tree *parent_tree, tvbuff_t
             video_conv_info = wmem_new(wmem_file_scope(), video_conv_info_t);
             video_conv_info->entities = wmem_tree_new(wmem_file_scope());
             usb_conv_info->class_data = video_conv_info;
+            usb_conv_info->class_data_type = USB_CONV_VIDEO;
+        } else if (usb_conv_info->class_data_type != USB_CONV_VIDEO) {
+            /* Stop dissection if another USB type is in the conversation */
+            return descriptor_len;
         }
 
         entity = (video_entity_t*) wmem_tree_lookup32(video_conv_info->entities, entity_id);
diff --git a/epan/dissectors/packet-usb.h b/epan/dissectors/packet-usb.h
index 20ecc80b04..261592db5d 100644
--- a/epan/dissectors/packet-usb.h
+++ b/epan/dissectors/packet-usb.h
@@ -90,6 +90,8 @@ typedef struct _usb_trans_info_t {
     guint64 usb_id;
 } usb_trans_info_t;
 
+enum usb_conv_class_data_type {USB_CONV_UNKNOWN = 0, USB_CONV_U3V, USB_CONV_AUDIO, USB_CONV_VIDEO, USB_CONV_MASS_STORAGE};
+
 /* Conversation Structure
  * there is one such structure for each device/endpoint conversation */
 struct _usb_conv_info_t {
@@ -113,7 +115,8 @@ struct _usb_conv_info_t {
     wmem_tree_t *transactions;
     usb_trans_info_t *usb_trans_info; /* pointer to the current transaction */
 
-    void *class_data;	/* private class/id decode data */
+    void *class_data;           /* private class/id decode data */
+    enum usb_conv_class_data_type class_data_type;
 
     wmem_array_t *alt_settings;
 };