USB: fix dissection of non standard USB setup requests

Otherwise captures like the one found in bug 8161 do not dissect properly anymore (sub dissector is called twice)

While we are at it, reorganize functions order to void a forward declaration

Change-Id: Id02ef835ba24981902a1702f976db099fa07b0fd
Reviewed-on: https://code.wireshark.org/review/3858
Reviewed-by: Martin Kaiser <wireshark@kaiser.cx>

1 files changed, 43 insertions, 50 deletions

diff --git a/epan/dissectors/packet-usb.c b/epan/dissectors/packet-usb.c
index 05b2aeb731..f62eaf0ca6 100644
--- a/epan/dissectors/packet-usb.c
+++ b/epan/dissectors/packet-usb.c
@@ -2793,9 +2793,40 @@ dissect_usb_bmrequesttype(proto_tree *parent_tree, tvbuff_t *tvb, int offset, in
 }
 
 static int
-try_dissect_linux_usb_pseudo_header_ext(tvbuff_t *tvb, int offset,
+dissect_linux_usb_pseudo_header_ext(tvbuff_t *tvb, int offset,
                                     packet_info *pinfo _U_,
-                                    proto_tree *tree, guint8 header_info);
+                                    proto_tree *tree)
+{
+    proto_tree_add_item(tree, hf_usb_urb_interval, tvb, offset, 4, ENC_HOST_ENDIAN);
+    offset += 4;
+
+    proto_tree_add_item(tree, hf_usb_urb_start_frame, tvb, offset, 4, ENC_HOST_ENDIAN);
+    offset += 4;
+
+    proto_tree_add_item(tree, hf_usb_urb_copy_of_transfer_flags, tvb, offset, 4, ENC_HOST_ENDIAN);
+    offset += 4;
+
+    proto_tree_add_item(tree, hf_usb_iso_numdesc, tvb, offset, 4, ENC_HOST_ENDIAN);
+    offset += 4;
+
+    return offset;
+}
+
+static int
+try_dissect_linux_usb_pseudo_header_ext(tvbuff_t *tvb, int offset,
+                                        packet_info *pinfo,
+                                        proto_tree *tree, guint8 header_info)
+{
+    /*
+     * If this has a 64-byte header, process the extra 16 bytes of
+     * pseudo-header information.
+     */
+    if ((header_info & USB_HEADER_IS_LINUX) &&
+        (header_info & USB_HEADER_IS_64_BYTES)) {
+        offset = dissect_linux_usb_pseudo_header_ext(tvb, offset, pinfo, tree);
+    }
+    return offset;
+}
 
 static int
 dissect_nonstandard_usb_setup_request(packet_info *pinfo, proto_tree *tree, proto_tree *parent,
@@ -2803,12 +2834,12 @@ dissect_nonstandard_usb_setup_request(packet_info *pinfo, proto_tree *tree, prot
                                       usb_conv_info_t *usb_conv_info, guint8 urb_type,
                                       guint8 header_info)
 {
-    tvbuff_t *setup_tvb = tvb_new_composite();
-    tvbuff_t *next_tvb = tvb_new_subset_length(tvb, offset - 7, 7);
-
+    tvbuff_t *next_tvb;
 
     if (header_info & (USB_HEADER_IS_LINUX | USB_HEADER_IS_64_BYTES)) {
 
+        tvbuff_t *setup_tvb = tvb_new_composite();
+        next_tvb = tvb_new_subset_length(tvb, offset - 7, 7);
         tvb_composite_append(setup_tvb, next_tvb);
 
         offset = try_dissect_linux_usb_pseudo_header_ext(tvb, offset, pinfo, tree, header_info);
@@ -2822,13 +2853,12 @@ dissect_nonstandard_usb_setup_request(packet_info *pinfo, proto_tree *tree, prot
             add_new_data_source(pinfo, next_tvb, "Linux USB Control");
 
             proto_tree_add_item(*setup_tree, hf_usb_data_fragment, tvb, offset, -1, ENC_NA);
-        }
-        else
+        } else {
             tvb_composite_finalize(setup_tvb);
-
+        }
     } else {
-        next_tvb = tvb_new_subset_remaining(tvb, offset - 7);
         offset = try_dissect_linux_usb_pseudo_header_ext(tvb, offset, pinfo, tree, header_info);
+        next_tvb = tvb_new_subset_remaining(tvb, offset - 7);
     }
 
     offset = try_dissect_next_protocol(tree, parent, next_tvb, offset, pinfo, usb_conv_info, urb_type);
@@ -2891,11 +2921,11 @@ dissect_usb_setup_request(packet_info *pinfo, proto_tree *tree,
     }
 
     if (req_type != RQT_SETUP_TYPE_STANDARD) {
-        dissect_nonstandard_usb_setup_request(pinfo, tree, parent, &setup_tree, tvb, offset,
-                                              usb_conv_info, urb_type, header_info);
-    } else
+        offset = dissect_nonstandard_usb_setup_request(pinfo, tree, parent, &setup_tree, tvb, offset,
+                                                       usb_conv_info, urb_type, header_info);
+    } else {
         offset = try_dissect_linux_usb_pseudo_header_ext(tvb, offset, pinfo, tree, header_info);
-
+    }
 
     return offset;
 }
@@ -2979,43 +3009,6 @@ dissect_linux_usb_pseudo_header(tvbuff_t *tvb, packet_info *pinfo, proto_tree *t
     return 40;
 }
 
-static int
-dissect_linux_usb_pseudo_header_ext(tvbuff_t *tvb, int offset,
-                                    packet_info *pinfo _U_,
-                                    proto_tree *tree)
-{
-    proto_tree_add_item(tree, hf_usb_urb_interval, tvb, offset, 4, ENC_HOST_ENDIAN);
-    offset += 4;
-
-    proto_tree_add_item(tree, hf_usb_urb_start_frame, tvb, offset, 4, ENC_HOST_ENDIAN);
-    offset += 4;
-
-    proto_tree_add_item(tree, hf_usb_urb_copy_of_transfer_flags, tvb, offset, 4, ENC_HOST_ENDIAN);
-    offset += 4;
-
-    proto_tree_add_item(tree, hf_usb_iso_numdesc, tvb, offset, 4, ENC_HOST_ENDIAN);
-    offset += 4;
-
-    return offset;
-}
-
-static int
-try_dissect_linux_usb_pseudo_header_ext(tvbuff_t *tvb, int offset,
-                                    packet_info *pinfo _U_,
-                                    proto_tree *tree, guint8 header_info)
-{
-    /*
-     * If this has a 64-byte header, process the extra 16 bytes of
-     * pseudo-header information.
-     */
-    if ((header_info & USB_HEADER_IS_LINUX) &&
-        (header_info & USB_HEADER_IS_64_BYTES)) {
-        offset = dissect_linux_usb_pseudo_header_ext(tvb, offset, pinfo, tree);
-    }
-    return offset;
-}
-
-
 /* dissect the usbpcap_buffer_packet_header and fill the conversation struct
    this function does not handle the transfer-specific headers
    return the number of bytes processed */