From Steve Magnani via https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=8338

Centralize logic related to per-interface conversations, and expose it for use
by class-specific dissectors.

Class-specific descriptor dissectors also need to know the interface in whose
context they are called to work.

This is a prerequisite for a USB Video Class dissector, which needs to decode
many class-specific descriptors.

git-svn-id: http://anonsvn.wireshark.org/wireshark/trunk@47990 f5534014-38df-0310-8fa8-9805f1628bb7

diff --git a/AUTHORS b/AUTHORS
index bb8e57d6668a338db2fa0306ecef339ae26d46df..5109f4048104c1be8af1edbe98052be084c8647b 100644 (file)
--- a/AUTHORS
+++ b/AUTHORS
@@ -3714,6 +3714,7 @@ Adam Butcher              <adam[AT]jessamine.co.uk>
 Hendrik Uhlmann                <Hendrik.Uhlmann[AT]rheinmetall.com>
 Alex Gaertner          <gaertner.alex[AT]gmx.de>
 Sebastiano Di Paola    <sebastiano.dipaola[AT]gmail.com>
+Steven J. Magnani      <steve[AT]digidescorp.com>
 
 
 Dan Lasley <dlasley[AT]promus.com> gave permission for his

diff --git a/epan/dissectors/packet-usb.c b/epan/dissectors/packet-usb.c
index e06870487e42d3f1f6066c2353084778731ac37b..0c1d98eff1396e19499b288b1c8eb848e23ec771 100644 (file)
--- a/epan/dissectors/packet-usb.c
+++ b/epan/dissectors/packet-usb.c
@@ -863,6 +863,23 @@ get_usb_conversation(packet_info *pinfo,
     return conversation;
 }
 
+/* Fetch or create usb_conv_info for a specified interface. */
+usb_conv_info_t *
+get_usb_iface_conv_info(packet_info *pinfo, guint8 interface_num)
+{
+    conversation_t *conversation;
+    guint32 if_port;
+
+    if_port = htolel(INTERFACE_PORT | interface_num);
+
+    if (pinfo->srcport == NO_ENDPOINT) {
+        conversation = get_usb_conversation(pinfo, &pinfo->src, &pinfo->dst, pinfo->srcport, if_port);
+    } else {
+        conversation = get_usb_conversation(pinfo, &pinfo->src, &pinfo->dst, if_port, pinfo->destport);
+    }
+
+    return get_usb_conv_info(conversation);
+}
 
 
 /* SETUP dissectors */
@@ -1259,6 +1276,7 @@ dissect_usb_interface_descriptor(packet_info *pinfo, proto_tree *parent_tree,
     /* bInterfaceNumber */
     interface_num = tvb_get_guint8(tvb, offset);
     proto_tree_add_item(tree, hf_usb_bInterfaceNumber, tvb, offset, 1, ENC_LITTLE_ENDIAN);
+    usb_conv_info->interfaceNum = interface_num;
     offset += 1;
 
     /* bAlternateSetting */
@@ -1279,19 +1297,11 @@ dissect_usb_interface_descriptor(packet_info *pinfo, proto_tree *parent_tree,
     proto_item_append_text(item, " (%u.%u): class %s", interface_num, alt_setting, class_str);
 
     if (!pinfo->fd->flags.visited && (alt_setting == 0)) {
-        conversation_t *conversation;
-        guint32 if_port;
-
-        usb_trans_info->interface_info = se_alloc0(sizeof(usb_conv_info_t));
+        /* Register conversation for this interface in case CONTROL messages are sent to it */
+        usb_trans_info->interface_info = get_usb_iface_conv_info(pinfo, interface_num);
         usb_trans_info->interface_info->interfaceClass = tvb_get_guint8(tvb, offset);
         /* save the subclass so we can access it later in class-specific descriptors */
         usb_trans_info->interface_info->interfaceSubclass = tvb_get_guint8(tvb, offset+1);
-        usb_trans_info->interface_info->transactions = se_tree_create_non_persistent(EMEM_TREE_TYPE_RED_BLACK, "usb transactions");
-
-        /* Register conversation for this interface in case CONTROL messages are sent to it */
-        if_port = htolel(INTERFACE_PORT | interface_num);
-        conversation = get_usb_conversation(pinfo, &pinfo->src, &pinfo->dst, if_port, pinfo->destport);
-        conversation_add_proto_data(conversation, proto_usb, usb_trans_info->interface_info);
     }
     offset += 1;
 
@@ -2541,10 +2551,8 @@ dissect_linux_usb_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent,
                 case RQT_SETUP_TYPE_CLASS:
                     /* Make sure we have the proper conversation */
                     if (USB_RECIPIENT(usb_trans_info->setup.requesttype) == RQT_SETUP_RECIPIENT_INTERFACE) {
-                        guint16 interface_num = usb_trans_info->setup.wIndex & 0xff;
-                        guint32 if_port = htolel(INTERFACE_PORT | interface_num);
-                        conversation = get_usb_conversation(pinfo, &pinfo->src, &pinfo->dst, pinfo->srcport, if_port);
-                        usb_conv_info = get_usb_conv_info(conversation);
+                        guint8 interface_num = usb_trans_info->setup.wIndex & 0xff;
+                        usb_conv_info = get_usb_iface_conv_info(pinfo, interface_num);
                         usb_conv_info->usb_trans_info = usb_trans_info;
                         pinfo->usb_conv_info = usb_conv_info;
                     } else if (USB_RECIPIENT(usb_trans_info->setup.requesttype) == RQT_SETUP_RECIPIENT_ENDPOINT) {
@@ -2627,9 +2635,8 @@ dissect_linux_usb_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent,
             if (usb_trans_info) {
                 if (USB_TYPE(usb_trans_info->setup.requesttype) == RQT_SETUP_TYPE_CLASS) {
                     if (USB_RECIPIENT(usb_trans_info->setup.requesttype) == RQT_SETUP_RECIPIENT_INTERFACE) {
-                        guint32 if_port = htolel(INTERFACE_PORT | (usb_trans_info->setup.wIndex & 0xff));
-                        conversation = get_usb_conversation(pinfo, &pinfo->src, &pinfo->dst, if_port, pinfo->destport);
-                        usb_conv_info = get_usb_conv_info(conversation);
+                        guint8 interface_num = usb_trans_info->setup.wIndex & 0xff;
+                        usb_conv_info = get_usb_iface_conv_info(pinfo, interface_num);
                         usb_conv_info->usb_trans_info = usb_trans_info;
                         pinfo->usb_conv_info = usb_conv_info;
                     } else if (USB_RECIPIENT(usb_trans_info->setup.requesttype) == RQT_SETUP_RECIPIENT_ENDPOINT) {

diff --git a/epan/dissectors/packet-usb.h b/epan/dissectors/packet-usb.h
index 549ebac90468ae574f1ded21a4e662fe69d200fc..d0b7b4e9abc0f0f0d6183cca0679bd911e695fb8 100644 (file)
--- a/epan/dissectors/packet-usb.h
+++ b/epan/dissectors/packet-usb.h
@@ -77,6 +77,7 @@ typedef struct _usb_trans_info_t {
 struct _usb_conv_info_t {
     guint16 interfaceClass;            /* class for this conversation */
     guint16 interfaceSubclass; /* Most recent interface descriptor subclass */
+    guint8  interfaceNum;       /* Most recent interface number */
     emem_tree_t *transactions;
     usb_trans_info_t *usb_trans_info; /* pointer to the current transaction */
     void *class_data;  /* private class/id decode data */
@@ -174,6 +175,8 @@ typedef struct _usb_data_t {
 #define ENDPOINT_TYPE_BULK              2
 #define ENDPOINT_TYPE_INTERRUPT         3
 
+usb_conv_info_t *get_usb_iface_conv_info(packet_info *pinfo, guint8 interface_num);
+
 void dissect_usb_descriptor_header(proto_tree *tree, tvbuff_t *tvb, int offset);
 void dissect_usb_endpoint_address(proto_tree *tree, tvbuff_t *tvb, int offset);