usb: use proto_tree_add_item() and proto_tree_add_item_ret_{u}int().

We now have ENC_HOST_ENDIAN, so we can use it to add host-endian fields
with proto_tree_add_item().

Instead of fetching field values directly, use
proto_tree_add_item_ret_{}int() to get the value.

Change-Id: I96b9a55174594bf04f805af559c2521cd813e8f3
Reviewed-on: https://code.wireshark.org/review/38021
Petri-Dish: Guy Harris <gharris@sonic.net>
Tested-by: Petri Dish Buildbot
Reviewed-by: Guy Harris <gharris@sonic.net>

1 files changed, 20 insertions, 32 deletions

diff --git a/epan/dissectors/packet-usb.c b/epan/dissectors/packet-usb.c
index 48ef0bcf78..057848653f 100644
--- a/epan/dissectors/packet-usb.c
+++ b/epan/dissectors/packet-usb.c
@@ -3903,6 +3903,7 @@ dissect_linux_usb_pseudo_header(tvbuff_t *tvb, packet_info *pinfo, proto_tree *t
     guint8  transfer_type_and_direction;
     guint8  urb_type;
     guint8  flag[2];
+    guint32 bus_id;
 
     *urb_id = tvb_get_guint64(tvb, 0, ENC_HOST_ENDIAN);
     proto_tree_add_uint64(tree, hf_usb_urb_id, tvb, 0, 8, *urb_id);
@@ -3931,8 +3932,8 @@ dissect_linux_usb_pseudo_header(tvbuff_t *tvb, packet_info *pinfo, proto_tree *t
     proto_tree_add_item(tree, hf_usb_device_address, tvb, 11, 1, ENC_LITTLE_ENDIAN);
     usb_conv_info->device_address = (guint16)tvb_get_guint8(tvb, 11);
 
-    proto_tree_add_item(tree, hf_usb_bus_id, tvb, 12, 2, ENC_HOST_ENDIAN);
-    tvb_memcpy(tvb, &usb_conv_info->bus_id, 12, 2);
+    proto_tree_add_item_ret_uint(tree, hf_usb_bus_id, tvb, 12, 2, ENC_HOST_ENDIAN, &bus_id);
+    usb_conv_info->bus_id = (guint16) bus_id;
 
     /* Right after the pseudo header we always have
      * sizeof(struct usb_device_setup_hdr) bytes. The content of these
@@ -4358,7 +4359,6 @@ dissect_linux_usb_iso_transfer(packet_info *pinfo _U_, proto_tree *urb_tree,
 {
     guint32     iso_numdesc = 0;
     proto_item *tii;
-    guint32     val32;
     guint32     i;
     guint       data_base;
     guint32     iso_status;
@@ -4380,17 +4380,10 @@ dissect_linux_usb_iso_transfer(packet_info *pinfo _U_, proto_tree *urb_tree,
     /* iso urbs on linux can't possibly contain a setup packet
        see mon_bin_event() in the linux kernel */
 
-    /* Process ISO related fields (usbmon_packet.iso). The fields are
-     * in host endian byte order so use tvb_memcopy() and
-     * proto_tree_add_uint() pair.
-     */
-
-    tvb_memcpy(tvb, (guint8 *)&val32, offset, 4);
-    proto_tree_add_uint(urb_tree, hf_usb_iso_error_count, tvb, offset, 4, val32);
+    proto_tree_add_item(urb_tree, hf_usb_iso_error_count, tvb, offset, 4, ENC_HOST_ENDIAN);
     offset += 4;
 
-    tvb_memcpy(tvb, (guint8 *)&iso_numdesc, offset, 4);
-    proto_tree_add_uint(urb_tree, hf_usb_iso_numdesc, tvb, offset, 4, iso_numdesc);
+    proto_tree_add_item_ret_uint(urb_tree, hf_usb_iso_numdesc, tvb, offset, 4, ENC_HOST_ENDIAN, &iso_numdesc);
     offset += 4;
 
     if (header_type == USB_HEADER_LINUX_64_BYTES) {
@@ -4401,26 +4394,21 @@ dissect_linux_usb_iso_transfer(packet_info *pinfo _U_, proto_tree *urb_tree,
     for (i = 0; i<iso_numdesc; i++) {
         proto_item   *iso_desc_ti;
         proto_tree   *iso_desc_tree;
-        guint32       iso_pad;
-
-        /* Fetch ISO descriptor fields stored in host endian byte order. */
-        tvb_memcpy(tvb, (guint8 *)&iso_status, offset, 4);
-        tvb_memcpy(tvb, (guint8 *)&iso_off, offset+4,  4);
-        tvb_memcpy(tvb, (guint8 *)&iso_len, offset+8,  4);
 
         iso_desc_ti = proto_tree_add_protocol_format(urb_tree, proto_usb, tvb, offset,
-                16, "USB isodesc %u [%s]", i, val_to_str_ext(iso_status, &linux_negative_errno_vals_ext, "Error %d"));
-        if (iso_len > 0)
-            proto_item_append_text(iso_desc_ti, " (%u bytes)", iso_len);
+                16, "USB isodesc %u", i);
         iso_desc_tree = proto_item_add_subtree(iso_desc_ti, ett_usb_isodesc);
 
-        proto_tree_add_int(iso_desc_tree, hf_usb_iso_status, tvb, offset, 4, iso_status);
+        proto_tree_add_item_ret_int(iso_desc_tree, hf_usb_iso_status, tvb, offset, 4, ENC_HOST_ENDIAN, &iso_status);
+        proto_item_append_text(iso_desc_ti, " [%s]", val_to_str_ext(iso_status, &linux_negative_errno_vals_ext, "Error %d"));
         offset += 4;
 
-        proto_tree_add_uint(iso_desc_tree, hf_usb_iso_off, tvb, offset, 4, iso_off);
+        proto_tree_add_item_ret_uint(iso_desc_tree, hf_usb_iso_off, tvb, offset, 4, ENC_HOST_ENDIAN, &iso_off);
         offset += 4;
 
-        proto_tree_add_uint(iso_desc_tree, hf_usb_iso_len, tvb, offset, 4, iso_len);
+        proto_tree_add_item_ret_uint(iso_desc_tree, hf_usb_iso_len, tvb, offset, 4, ENC_HOST_ENDIAN, &iso_len);
+        if (iso_len != 0)
+            proto_item_append_text(iso_desc_ti, " (%u bytes)", iso_len);
         offset += 4;
 
         /* Show the ISO data if we captured them and either the status
@@ -4434,8 +4422,7 @@ dissect_linux_usb_iso_transfer(packet_info *pinfo _U_, proto_tree *urb_tree,
             proto_tree_set_appendix(iso_desc_tree, tvb, (gint)(data_base+iso_off), (gint)iso_len);
         }
 
-        tvb_memcpy(tvb, (guint8 *)&iso_pad, offset, 4);
-        proto_tree_add_uint(iso_desc_tree, hf_usb_iso_pad, tvb, offset, 4, iso_pad);
+        proto_tree_add_item(iso_desc_tree, hf_usb_iso_pad, tvb, offset, 4, ENC_HOST_ENDIAN);
         offset += 4;
     }
 
@@ -4473,11 +4460,10 @@ dissect_usbip_iso_transfer(packet_info *pinfo _U_, proto_tree *urb_tree,
     for (i = 0; i<iso_numdesc; i++) {
         proto_item   *iso_desc_ti;
         proto_tree   *iso_desc_tree;
-        gint         iso_status;
+        gint32        iso_status;
 
-        iso_status = tvb_get_ntohl(tvb, desc_offset + 12);
         iso_desc_ti = proto_tree_add_protocol_format(urb_tree, proto_usb, tvb, desc_offset,
-                16, "USB isodesc %u [%s]", i, val_to_str_ext(iso_status, &linux_negative_errno_vals_ext, "Error %d"));
+                16, "USB isodesc %u", i);
         iso_desc_tree = proto_item_add_subtree(iso_desc_ti, ett_usb_isodesc);
 
         proto_tree_add_item_ret_uint(iso_desc_tree, hf_usb_iso_off, tvb, desc_offset, 4, ENC_BIG_ENDIAN, &iso_off);
@@ -4488,12 +4474,14 @@ dissect_usbip_iso_transfer(packet_info *pinfo _U_, proto_tree *urb_tree,
 
         proto_tree_add_item_ret_uint(iso_desc_tree, hf_usb_iso_actual_len, tvb, desc_offset, 4, ENC_BIG_ENDIAN, &iso_len);
         desc_offset += 4;
-        if (iso_len > 0)
-            proto_item_append_text(iso_desc_ti, " (%u bytes)", iso_len);
 
-        proto_tree_add_int(iso_desc_tree, hf_usb_iso_status, tvb, desc_offset, 4, iso_status);
+        proto_tree_add_item_ret_int(iso_desc_tree, hf_usb_iso_status, tvb, desc_offset, 4, ENC_BIG_ENDIAN, &iso_status);
+        proto_item_append_text(iso_desc_ti, " [%s]", val_to_str_ext(iso_status, &linux_negative_errno_vals_ext, "Error %d"));
         desc_offset += 4;
 
+        if (iso_len > 0)
+            proto_item_append_text(iso_desc_ti, " (%u bytes)", iso_len);
+
         /* Show the ISO data if we captured them and either the status
            is OK or the packet is sent from host to device.
            The Linux kernel sets the status field in outgoing isochronous