Bluetooth: L2CAP: Another fix for CIDs

Example: if there is Connection Request than field with CID always
is called SCID. If we Sent this packet, it is okay, but if we Receive
it, then it is not SCID for us, but DCID. If we receive
Connection Request (DCID) and than we want to make disconnection,
so we send Disconnection Request with DCID that is SCID in
Connection Request... etc.

I try to clarify this, so rename stored SCID to Local CID
and DCID  to Remote CID.

Change-Id: Idde0939a03955d8f4a10d8c9f7c43fd364254460
Reviewed-on: https://code.wireshark.org/review/1879
Reviewed-by: Michal Labedzki <michal.labedzki@tieto.com>

1 files changed, 44 insertions, 43 deletions

diff --git a/epan/dissectors/packet-btl2cap.c b/epan/dissectors/packet-btl2cap.c
index 72090c5972..c0e0228208 100644
--- a/epan/dissectors/packet-btl2cap.c
+++ b/epan/dissectors/packet-btl2cap.c
@@ -152,7 +152,8 @@ static dissector_table_t l2cap_service_dissector_table;
 
 /* This table maps cid values to psm values.
  * The same table is used both for SCID and DCID.
- * For received CIDs we 'or' the cid with 0x80000000 in this table
+ * For Remote CIDs (Receive Request SCID or Sent Response DCID)
+ * we 'or' the CID with 0x80000000 in this table
  */
 static wmem_tree_t *cid_to_psm_table  = NULL;
 
@@ -178,10 +179,8 @@ typedef struct _psm_data_t {
     guint32       interface_id;
     guint32       adapter_id;
     guint32       chandle;
-    gint32        scid;
-    gint32        dcid;
-    guint32       first_scid_frame;
-    guint32       first_dcid_frame;
+    gint32        local_cid;
+    gint32        remote_cid;
     guint16       psm;
     gboolean      local_service;
     guint32       disconnect_in_frame;
@@ -622,11 +621,14 @@ dissect_connrequest(tvbuff_t *tvb, int offset, packet_info *pinfo,
         k_frame_number = pinfo->fd->num;
 
         psm_data = wmem_new(wmem_file_scope(), psm_data_t);
-        psm_data->scid = (scid | ((pinfo->p2p_dir == P2P_DIR_RECV) ? 0x80000000 : 0x00000000));
-        psm_data->dcid = 0;
+        if (pinfo->p2p_dir == P2P_DIR_RECV) {
+            psm_data->local_cid = 0;
+            psm_data->remote_cid = scid |  0x80000000;
+        } else {
+            psm_data->local_cid = scid;
+            psm_data->remote_cid = 0;
+        }
         psm_data->psm  = psm;
-        psm_data->first_scid_frame = 0;
-        psm_data->first_dcid_frame = 0;
         psm_data->local_service = (pinfo->p2p_dir == P2P_DIR_RECV) ? TRUE : FALSE;
         psm_data->in.mode      = 0;
         psm_data->in.txwindow  = 0;
@@ -876,7 +878,8 @@ dissect_configrequest(tvbuff_t *tvb, int offset, packet_info *pinfo,
         if (psm_data && psm_data->interface_id == interface_id &&
                 psm_data->adapter_id == adapter_id &&
                 psm_data->chandle == chandle &&
-                psm_data->dcid == cid &&
+                ((pinfo->p2p_dir == P2P_DIR_SENT && psm_data->remote_cid == cid) ||
+                (pinfo->p2p_dir == P2P_DIR_RECV && psm_data->local_cid == cid)) &&
                 psm_data->disconnect_in_frame > pinfo->fd->num) {
             if (pinfo->p2p_dir == P2P_DIR_RECV)
                 config_data = &(psm_data->out);
@@ -1070,7 +1073,8 @@ dissect_configresponse(tvbuff_t *tvb, int offset, packet_info *pinfo,
         if (psm_data && psm_data->interface_id == interface_id &&
                 psm_data->adapter_id == adapter_id &&
                 psm_data->chandle == chandle &&
-                psm_data->scid == cid &&
+                ((pinfo->p2p_dir == P2P_DIR_SENT && psm_data->local_cid == cid) ||
+                (pinfo->p2p_dir == P2P_DIR_RECV && psm_data->remote_cid == cid)) &&
                 psm_data->disconnect_in_frame > pinfo->fd->num) {
             if (pinfo->p2p_dir == P2P_DIR_RECV)
                 config_data = &(psm_data->out);
@@ -1158,7 +1162,8 @@ dissect_connresponse(tvbuff_t *tvb, int offset, packet_info *pinfo,
         if (psm_data && psm_data->interface_id == interface_id &&
                 psm_data->adapter_id == adapter_id &&
                 psm_data->chandle == chandle &&
-                psm_data->scid == (scid | ((pinfo->p2p_dir == P2P_DIR_RECV) ? 0x00000000 : 0x80000000)) &&
+                ((pinfo->p2p_dir == P2P_DIR_SENT && psm_data->remote_cid == cid) ||
+                (pinfo->p2p_dir == P2P_DIR_RECV && psm_data->local_cid == cid)) &&
                 psm_data->disconnect_in_frame > pinfo->fd->num) {
             cid = dcid | ((pinfo->p2p_dir == P2P_DIR_RECV) ? 0x80000000 : 0x00000000);
 
@@ -1181,7 +1186,10 @@ dissect_connresponse(tvbuff_t *tvb, int offset, packet_info *pinfo,
             key[5].length = 0;
             key[5].key    = NULL;
 
-            psm_data->dcid = cid;
+            if (pinfo->p2p_dir == P2P_DIR_RECV)
+                psm_data->remote_cid = cid;
+            else
+                psm_data->local_cid = cid;
 
             wmem_tree_insert32_array(cid_to_psm_table, key, psm_data);
         }
@@ -1327,12 +1335,13 @@ dissect_disconnrequestresponse(tvbuff_t *tvb, int offset, packet_info *pinfo,
             interface_id = HCI_INTERFACE_DEFAULT;
         adapter_id   = (acl_data) ? acl_data->adapter_id : HCI_ADAPTER_DEFAULT;
         chandle      = (acl_data) ? acl_data->chandle : 0;
-        if (is_request) {
-            key_dcid     = dcid | ((pinfo->p2p_dir == P2P_DIR_RECV) ? 0x00000000 : 0x80000000);
-            key_scid     = scid | ((pinfo->p2p_dir == P2P_DIR_RECV) ? 0x80000000 : 0x00000000);
+        if ((is_request && pinfo->p2p_dir == P2P_DIR_SENT) ||
+                (!is_request && pinfo->p2p_dir == P2P_DIR_RECV)) {
+            key_dcid     = dcid | 0x80000000;
+            key_scid     = scid;
         } else {
-            key_dcid     = dcid | ((pinfo->p2p_dir == P2P_DIR_RECV) ? 0x80000000 : 0x00000000);
-            key_scid     = scid | ((pinfo->p2p_dir == P2P_DIR_RECV) ? 0x00000000 : 0x80000000);
+            key_dcid     = scid | 0x80000000;
+            key_scid     = dcid;
         }
 
         k_interface_id = interface_id;
@@ -1358,7 +1367,7 @@ dissect_disconnrequestresponse(tvbuff_t *tvb, int offset, packet_info *pinfo,
         if (psm_data && psm_data->interface_id == interface_id &&
                 psm_data->adapter_id == adapter_id &&
                 psm_data->chandle == chandle &&
-                psm_data->dcid == key_dcid &&
+                psm_data->remote_cid == key_dcid &&
                 psm_data->disconnect_in_frame == G_MAXUINT32) {
             psm_data->disconnect_in_frame = pinfo->fd->num;
         }
@@ -1386,7 +1395,7 @@ dissect_disconnrequestresponse(tvbuff_t *tvb, int offset, packet_info *pinfo,
         if (psm_data && psm_data->interface_id == interface_id &&
                 psm_data->adapter_id == adapter_id &&
                 psm_data->chandle == chandle &&
-                psm_data->scid == key_scid &&
+                psm_data->local_cid == key_scid &&
                 psm_data->disconnect_in_frame == G_MAXUINT32) {
             psm_data->disconnect_in_frame = pinfo->fd->num;
         }
@@ -1711,11 +1720,10 @@ dissect_btl2cap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
     l2cap_data->adapter_id       = (acl_data) ? acl_data->adapter_id : HCI_ADAPTER_DEFAULT;
     l2cap_data->chandle          = (acl_data) ? acl_data->chandle : 0;
     l2cap_data->cid              = cid;
-    l2cap_data->scid             = -1;
-    l2cap_data->dcid             = -1;
+    l2cap_data->local_cid        = -1;
+    l2cap_data->remote_cid       = -1;
     l2cap_data->is_local_psm     = FALSE;
     l2cap_data->psm              = 0;
-    l2cap_data->first_scid_frame = 0;
     l2cap_data->disconnect_in_frame = &max_disconnect_in_frame;
     l2cap_data->remote_bd_addr_oui = (acl_data) ? acl_data->remote_bd_addr_oui : 0;
     l2cap_data->remote_bd_addr_id = (acl_data) ? acl_data->remote_bd_addr_id : 0;
@@ -1886,10 +1894,15 @@ dissect_btl2cap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
         col_append_str(pinfo->cinfo, COL_INFO, "Connectionless reception channel");
 
         psm = tvb_get_letohs(tvb, offset);
-        l2cap_data->scid = psm_data->scid;
-        l2cap_data->dcid = psm_data->dcid;
+        if (pinfo->p2p_dir == P2P_DIR_RECV) {
+            l2cap_data->local_cid = cid;
+            l2cap_data->remote_cid = -1;
+        } else {
+            l2cap_data->local_cid = -1;
+            l2cap_data->remote_cid = cid;
+        }
         l2cap_data->psm = psm;
-        l2cap_data->disconnect_in_frame = &psm_data->disconnect_in_frame;
+        l2cap_data->disconnect_in_frame = &max_disconnect_in_frame;
 
         if (p_get_proto_data(pinfo->pool, pinfo, proto_btl2cap, BTL2CAP_PSM_CONV ) == NULL) {
             p_add_proto_data(pinfo->pool, pinfo, proto_btl2cap, BTL2CAP_PSM_CONV, GUINT_TO_POINTER((guint)psm));
@@ -1999,28 +2012,16 @@ dissect_btl2cap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
         if (psm_data && psm_data->interface_id == interface_id &&
                 psm_data->adapter_id == adapter_id &&
                 psm_data->chandle == chandle &&
-                (psm_data->scid == key_cid ||
-                psm_data->dcid == key_cid) &&
+                (psm_data->local_cid == key_cid ||
+                psm_data->remote_cid == key_cid) &&
                 psm_data->disconnect_in_frame > pinfo->fd->num) {
             config_data_t  *config_data;
 
-            if ((psm_data->scid == key_cid) &&
-                    psm_data->first_scid_frame == 0) {
-                psm_data->first_scid_frame = pinfo->fd->num;
-            }
-
-            if ((psm_data->dcid == key_cid) &&
-                    psm_data->first_dcid_frame == 0) {
-                psm_data->first_dcid_frame = pinfo->fd->num;
-            }
-
             psm = psm_data->psm;
-            l2cap_data->scid = psm_data->scid;
-            l2cap_data->dcid = psm_data->dcid;
+            l2cap_data->local_cid = psm_data->local_cid;
+            l2cap_data->remote_cid = psm_data->remote_cid;
             l2cap_data->psm = psm;
             l2cap_data->is_local_psm = psm_data->local_service;
-            l2cap_data->first_scid_frame = psm_data->first_scid_frame;
-            l2cap_data->first_dcid_frame = psm_data->first_dcid_frame;
             l2cap_data->disconnect_in_frame = &psm_data->disconnect_in_frame;
 
             if (pinfo->p2p_dir == P2P_DIR_RECV)
@@ -2555,7 +2556,7 @@ proto_register_btl2cap(void)
     expert_btl2cap = expert_register_protocol(proto_btl2cap);
     expert_register_field_array(expert_btl2cap, ei, array_length(ei));
 
-    cid_to_psm_table     = wmem_tree_new_autoreset(wmem_epan_scope(), wmem_file_scope()); /* scid: psm */
+    cid_to_psm_table     = wmem_tree_new_autoreset(wmem_epan_scope(), wmem_file_scope());
 
     register_decode_as(&btl2cap_cid_da);
     register_decode_as(&btl2cap_psm_da);