/* TODO mix direction bit into the chandle tree lookup so we can handle when fragments sent in both directions simultaneously on the same chandle */ /* packet-btacl_acl.c * Routines for the Bluetooth ACL dissection * Copyright 2002, Christoph Scholz * From: http://affix.sourceforge.net/archive/ethereal_affix-3.patch * * Refactored for wireshark checkin * Ronnie Sahlberg 2006 * * $Id$ * * Wireshark - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #ifdef HAVE_CONFIG_H # include "config.h" #endif #include #include #include #include #include #include #include /* Initialize the protocol and registered fields */ static int proto_btacl = -1; static int hf_btacl_chandle = -1; static int hf_btacl_pb_flag = -1; static int hf_btacl_bc_flag = -1; static int hf_btacl_length = -1; static int hf_btacl_data = -1; static int hf_btacl_continuation_to = -1; static int hf_btacl_reassembled_in = -1; /* Initialize the subtree pointers */ static gint ett_btacl = -1; static dissector_handle_t btl2cap_handle = NULL; static gboolean acl_reassembly = TRUE; typedef struct _multi_fragment_pdu_t { guint32 first_frame; guint32 last_frame; guint16 tot_len; char *reassembled; int cur_off; /* counter used by reassembly */ } multi_fragment_pdu_t; typedef struct _chandle_data_t { emem_tree_t *start_fragments; /* indexed by pinfo->fd->num */ } chandle_data_t; static emem_tree_t *chandle_tree = NULL; static const value_string pb_flag_vals[] = { {0, "First Non-automatically Flushable Packet"}, {1, "Continuing Fragment"}, {2, "First Automatically Flushable Packet"}, {0, NULL } }; static const value_string bc_flag_vals[] = { {0, "Point-To-Point"}, {1, "Active Broadcast"}, {2, "Piconet Broadcast"}, {0, NULL } }; /* Code to actually dissect the packets */ static void dissect_btacl(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) { proto_item *ti = NULL; proto_tree *btacl_tree = NULL; guint16 flags, length; gboolean fragmented; int offset = 0; guint16 pb_flag, l2cap_length = 0; tvbuff_t *next_tvb; bthci_acl_data_t *acl_data; chandle_data_t *chandle_data; void* pd_save; col_set_str(pinfo->cinfo, COL_PROTOCOL, "HCI_ACL"); if (tree) { ti = proto_tree_add_item(tree, proto_btacl, tvb, offset, -1, ENC_NA); btacl_tree = proto_item_add_subtree(ti, ett_btacl); } flags = tvb_get_letohs(tvb, offset); pb_flag = (flags & 0x3000) >> 12; proto_tree_add_item(btacl_tree, hf_btacl_chandle, tvb, offset, 2, ENC_LITTLE_ENDIAN); proto_tree_add_item(btacl_tree, hf_btacl_pb_flag, tvb, offset, 2, ENC_LITTLE_ENDIAN); proto_tree_add_item(btacl_tree, hf_btacl_bc_flag, tvb, offset, 2, ENC_LITTLE_ENDIAN); offset += 2; acl_data = ep_alloc(sizeof(bthci_acl_data_t)); acl_data->chandle = flags&0x0fff; pd_save = pinfo->private_data; pinfo->private_data = acl_data; /* find the chandle_data structure associated with this chandle */ chandle_data = se_tree_lookup32(chandle_tree, acl_data->chandle); if (!chandle_data) { chandle_data = se_alloc(sizeof(chandle_data_t)); chandle_data->start_fragments = se_tree_create_non_persistent(EMEM_TREE_TYPE_RED_BLACK, "bthci_acl fragment starts"); se_tree_insert32(chandle_tree, acl_data->chandle, chandle_data); } length = tvb_get_letohs(tvb, offset); proto_tree_add_item(btacl_tree, hf_btacl_length, tvb, offset, 2, ENC_LITTLE_ENDIAN); offset+=2; /* determine if packet is fragmented */ switch(pb_flag) { case 0x01: /* Continuation fragment */ fragmented = TRUE; break; case 0x00: /* First fragment/packet, non-auto flushable */ case 0x02: /* First fragment/packet, auto flushable */ l2cap_length = tvb_get_letohs(tvb, offset); fragmented = ((l2cap_length+4)!=length); break; default: /* unknown pb_flag */ fragmented = FALSE; } if ((!fragmented) || ((!acl_reassembly)&& !(pb_flag&0x01))) { /* call L2CAP dissector for PDUs that are not fragmented * also for the first fragment if reassembly is disabled */ next_tvb = tvb_new_subset(tvb, offset, tvb_length_remaining(tvb, offset), length); if (btl2cap_handle) { call_dissector(btl2cap_handle, next_tvb, pinfo, tree); } pinfo->private_data = pd_save; return; } if (fragmented && acl_reassembly) { multi_fragment_pdu_t *mfp = NULL; gint len; if (!(pb_flag&0x01)) { /* first fragment */ if (!pinfo->fd->flags.visited) { mfp = se_alloc(sizeof(multi_fragment_pdu_t)); mfp->first_frame = pinfo->fd->num; mfp->last_frame = 0; mfp->tot_len = l2cap_length+4; mfp->reassembled = se_alloc(mfp->tot_len); len = tvb_length_remaining(tvb, offset); if (len <= mfp->tot_len) { tvb_memcpy(tvb, (guint8*)mfp->reassembled, offset, len); mfp->cur_off = len; se_tree_insert32(chandle_data->start_fragments, pinfo->fd->num, mfp); } } else { mfp = se_tree_lookup32(chandle_data->start_fragments, pinfo->fd->num); } if (mfp != NULL && mfp->last_frame) { proto_item *item; item = proto_tree_add_uint(btacl_tree, hf_btacl_reassembled_in, tvb, 0, 0, mfp->last_frame); PROTO_ITEM_SET_GENERATED(item); col_append_fstr(pinfo->cinfo, COL_INFO, " [Reassembled in #%u]", mfp->last_frame); } } if (pb_flag == 0x01) { /* continuation fragment */ mfp = se_tree_lookup32_le(chandle_data->start_fragments, pinfo->fd->num); if (!pinfo->fd->flags.visited) { len = tvb_length_remaining(tvb, offset); if (mfp != NULL && !mfp->last_frame && (mfp->tot_len>=mfp->cur_off+len)) { tvb_memcpy(tvb, (guint8*)mfp->reassembled+mfp->cur_off, offset, len); mfp->cur_off+=len; if (mfp->cur_off == mfp->tot_len) { mfp->last_frame = pinfo->fd->num; } } } if (mfp) { proto_item *item; item = proto_tree_add_uint(btacl_tree, hf_btacl_continuation_to, tvb, 0, 0, mfp->first_frame); PROTO_ITEM_SET_GENERATED(item); col_append_fstr(pinfo->cinfo, COL_INFO, " [Continuation to #%u]", mfp->first_frame); } if (mfp != NULL && mfp->last_frame == pinfo->fd->num) { next_tvb = tvb_new_child_real_data(tvb, (guint8*)mfp->reassembled, mfp->tot_len, mfp->tot_len); add_new_data_source(pinfo, next_tvb, "Reassembled BTHCI ACL"); /* call L2CAP dissector */ if (btl2cap_handle) { call_dissector(btl2cap_handle, next_tvb, pinfo, tree); } } } } pinfo->private_data = pd_save; } void proto_register_btacl(void) { /* Setup list of header fields See Section 1.6.1 for details*/ static hf_register_info hf[] = { { &hf_btacl_chandle, { "Connection Handle", "bthci_acl.chandle", FT_UINT16, BASE_HEX, NULL, 0x0FFF, NULL, HFILL } }, { &hf_btacl_pb_flag, { "PB Flag", "bthci_acl.pb_flag", FT_UINT16, BASE_DEC, VALS(pb_flag_vals), 0x3000, "Packet Boundary Flag", HFILL } }, { &hf_btacl_bc_flag, { "BC Flag", "bthci_acl.bc_flag", FT_UINT16, BASE_DEC, VALS(bc_flag_vals), 0xC000, "Broadcast Flag", HFILL } }, { &hf_btacl_length, { "Data Total Length", "bthci_acl.length", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL } }, { &hf_btacl_data, { "Data", "bthci_acl.data", FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL } }, { &hf_btacl_continuation_to, { "This is a continuation to the PDU in frame", "bthci_acl.continuation_to", FT_FRAMENUM, BASE_NONE, NULL, 0x0, "This is a continuation to the PDU in frame #", HFILL } }, { &hf_btacl_reassembled_in, { "This PDU is reassembled in frame", "bthci_acl.reassembled_in", FT_FRAMENUM, BASE_NONE, NULL, 0x0, "This PDU is reassembled in frame #", HFILL } }, }; /* Setup protocol subtree array */ static gint *ett[] = { &ett_btacl, }; module_t *btacl_module; /* Register the protocol name and description */ proto_btacl = proto_register_protocol("Bluetooth HCI ACL Packet", "HCI_ACL", "bthci_acl"); register_dissector("bthci_acl", dissect_btacl, proto_btacl); /* Required function calls to register the header fields and subtrees used */ proto_register_field_array(proto_btacl, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); /* Register configuration preferences */ btacl_module = prefs_register_protocol(proto_btacl, NULL); prefs_register_bool_preference(btacl_module, "btacl_reassembly", "Reassemble ACL Fragments", "Whether the ACL dissector should reassemble fragmented PDUs", &acl_reassembly); chandle_tree = se_tree_create(EMEM_TREE_TYPE_RED_BLACK, "bthci_acl chandles"); } void proto_reg_handoff_btacl(void) { dissector_handle_t bthci_acl_handle; bthci_acl_handle = find_dissector("bthci_acl"); dissector_add_uint("hci_h4.type", HCI_H4_TYPE_ACL, bthci_acl_handle); dissector_add_uint("hci_h1.type", BTHCI_CHANNEL_ACL, bthci_acl_handle); btl2cap_handle = find_dissector("btl2cap"); }