Bluetooth: ACL/AVDTP: Fix ACL session handling

In case like reusing "connection handle" number in next connection
(2 -> 3 -> 2 again) AVDTP dissector does not properly dissected packets
(it should be Signal, but dissect as Media).

Add expert error to all packets that are not in ACL connection. This will
show invalid packages (send after dissconnect), however incomplete
(mostly beginning) connection will be marked too, but I think it have more
pros than cons.

Change-Id: I29cf706600cb12c8b93d0188dd2fba18dd5eba88
Reviewed-on: https://code.wireshark.org/review/4167
Petri-Dish: Michal Labedzki <michal.labedzki@tieto.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Michael Mann <mmann78@netscape.net>

1 files changed, 22 insertions, 7 deletions

diff --git a/epan/dissectors/packet-bthci_acl.c b/epan/dissectors/packet-bthci_acl.c
index 6ee0db654b..fbb9fb7051 100644
--- a/epan/dissectors/packet-bthci_acl.c
+++ b/epan/dissectors/packet-bthci_acl.c
@@ -31,6 +31,7 @@
 #include <epan/prefs.h>
 #include <epan/addr_resolv.h>
 #include <epan/wmem/wmem.h>
+#include <epan/expert.h>
 
 #include "packet-bluetooth-hci.h"
 #include "packet-bthci_acl.h"
@@ -54,6 +55,8 @@ static int hf_bthci_acl_dst_name = -1;
 /* Initialize the subtree pointers */
 static gint ett_bthci_acl = -1;
 
+static expert_field ei_invalid_session = EI_INIT;
+
 static dissector_handle_t bthci_acl_handle;
 static dissector_handle_t btl2cap_handle = NULL;
 
@@ -87,7 +90,7 @@ static const value_string bc_flag_vals[] = {
     { 0, NULL }
 };
 
-static guint32 max_disconnect_in_frame = G_MAXUINT32;
+static guint32 invalid_session = 0;
 
 
 void proto_register_bthci_acl(void);
@@ -97,7 +100,7 @@ void proto_reg_handoff_bthci_acl(void);
 static gint
 dissect_bthci_acl(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
 {
-    proto_item               *ti;
+    proto_item               *bthci_acl_itam;
     proto_tree               *bthci_acl_tree;
     proto_item               *sub_item;
     guint16                   flags;
@@ -138,8 +141,8 @@ dissect_bthci_acl(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *dat
         return 0;
     hci_data = (hci_data_t *) data;
 
-    ti = proto_tree_add_item(tree, proto_bthci_acl, tvb, offset, -1, ENC_NA);
-    bthci_acl_tree = proto_item_add_subtree(ti, ett_bthci_acl);
+    bthci_acl_itam = proto_tree_add_item(tree, proto_bthci_acl, tvb, offset, -1, ENC_NA);
+    bthci_acl_tree = proto_item_add_subtree(bthci_acl_itam, ett_bthci_acl);
 
     switch (pinfo->p2p_dir) {
         case P2P_DIR_SENT:
@@ -191,7 +194,8 @@ dissect_bthci_acl(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *dat
             chandle_session->disconnect_in_frame > pinfo->fd->num) {
         acl_data->disconnect_in_frame = &chandle_session->disconnect_in_frame;
     } else {
-        acl_data->disconnect_in_frame = &max_disconnect_in_frame;
+        acl_data->disconnect_in_frame = &invalid_session;
+        chandle_session = NULL;
     }
 
     acl_data->remote_bd_addr_oui         = 0;
@@ -429,6 +433,10 @@ dissect_bthci_acl(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *dat
         }
     }
 
+    if (acl_data->disconnect_in_frame == &invalid_session) {
+        expert_add_info(pinfo, bthci_acl_itam, &ei_invalid_session);
+    }
+
     SET_ADDRESS(&pinfo->net_src, AT_STRINGZ, (int)strlen(src_name) + 1, src_name);
     SET_ADDRESS(&pinfo->dl_src, AT_ETHER, 6, src_bd_addr);
     SET_ADDRESS(&pinfo->src, AT_STRINGZ, (int)strlen(src_addr_name) + 1, src_addr_name);
@@ -456,7 +464,8 @@ dissect_bthci_acl(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *dat
 void
 proto_register_bthci_acl(void)
 {
-
+    module_t         *bthci_acl_module;
+    expert_module_t  *bthci_acl_expert_module;
     /* Setup list of header fields  See Section 1.6.1 for details*/
     static hf_register_info hf[] = {
         { &hf_bthci_acl_chandle,
@@ -530,7 +539,10 @@ proto_register_bthci_acl(void)
     static gint *ett[] = {
         &ett_bthci_acl,
     };
-    module_t *bthci_acl_module;
+
+    static ei_register_info ei[] = {
+        { &ei_invalid_session, { "bthci_acl.invalid_session", PI_PROTOCOL, PI_ERROR, "Frame is out of any \"connection handle\" session", EXPFILL }},
+    };
 
     /* Register the protocol name and description */
     proto_bthci_acl = proto_register_protocol("Bluetooth HCI ACL Packet", "HCI_ACL", "bthci_acl");
@@ -540,6 +552,9 @@ proto_register_bthci_acl(void)
     proto_register_field_array(proto_bthci_acl, hf, array_length(hf));
     proto_register_subtree_array(ett, array_length(ett));
 
+    bthci_acl_expert_module = expert_register_protocol(proto_bthci_acl);
+    expert_register_field_array(bthci_acl_expert_module, ei, array_length(ei));
+
     /* Register configuration preferences */
     bthci_acl_module = prefs_register_protocol(proto_bthci_acl, NULL);
     prefs_register_bool_preference(bthci_acl_module, "hci_acl_reassembly",