/* 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 /* 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; /* Initialize the subtree pointers */ static gint ett_btacl = -1; dissector_handle_t btl2cap_handle=NULL; static const value_string pb_flag_vals[] = { {1, "Continuing Fragment"}, {2, "Start Fragment"}, {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; tvbuff_t *next_tvb; bthci_acl_data_t *acl_data; if(check_col(pinfo->cinfo, COL_PROTOCOL)){ col_set_str(pinfo->cinfo, COL_PROTOCOL, "HCI_ACL"); } if(tree){ ti=proto_tree_add_item(tree, proto_btacl, tvb, offset, -1, FALSE); 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, TRUE); proto_tree_add_item(btacl_tree, hf_btacl_pb_flag, tvb, offset, 2, TRUE); proto_tree_add_item(btacl_tree, hf_btacl_bc_flag, tvb, offset, 2, TRUE); offset+=2; acl_data=ep_alloc(sizeof(bthci_acl_data_t)); pinfo->private_data=acl_data; acl_data->chandle=flags&0x0fff; length = tvb_get_letohs(tvb, offset); proto_tree_add_item(btacl_tree, hf_btacl_length, tvb, offset, 2, TRUE); offset+=2; /* determine if packet is fragmented */ switch(pb_flag){ case 0x01: /* Continuation fragment */ fragmented = TRUE; break; case 0x02: /* Start fragment */ if(length < 2){ fragmented=TRUE; } else { l2cap_length=tvb_get_letohs(tvb, offset); fragmented=((l2cap_length+4)!=length); } break; default: /* unknown pb_flag */ fragmented = FALSE; } if(!fragmented){ /* call L2CAP dissector */ next_tvb=tvb_new_subset(tvb, offset, tvb_length_remaining(tvb, offset), length); if(btl2cap_handle){ call_dissector(btl2cap_handle, next_tvb, pinfo, tree); } return; } #ifdef REMOVED offset==4 here /* the code below should be rewritten from scratch once a doc explaining how fragmented bt packets work and example captures are collected. */ guint16 chandle, handle; struct l2cap_packet *l2p; proto_tree_add_item(btacl_tree, hf_btacl_data, tvb, 4, -1, TRUE); if (pinfo->fd->flags.visited == 0) { /* This is the first pass */ chandle = flags & 0x0FFF; /* same connection handle but differnet direction needs to be distinguished, therefore we set the highest bit of the handle for outgoing packets */ if (pinfo->p2p_dir == P2P_DIR_RECV) { handle = chandle; } else { handle = chandle + 0x8000; } l2p = NULL; if (pb_flag == 2) { /* Start Fragment */ if (check_col(pinfo->cinfo, COL_INFO)) col_append_str(pinfo->cinfo, COL_INFO, " (Start Fragment)"); if (get_l2p(handle)) { /* Error: There is still data for the same handle */ fprintf(stderr, "Incomplete L2CAP packet detected: packet no. %d\n", pinfo->fd->num); del_l2p(handle, 1); } /* Start reassembly */ if ((l2p = add_l2p(handle))) { l2p->pkt_len = 65540; /* Maybe we don't know the length now */ /* So we have to set it to maximum */ /* memcpy the data */ tvb_memcpy(tvb, l2p->data, 4, length); l2p->rx_count = length; } else { fprintf(stderr, "no more handles!\n"); } } else if (pb_flag == 1) { /* Continuing Fragment */ if (!(l2p = get_l2p(handle))) { /* Error: Cont fragment without start */ fprintf(stderr, "Cont. fragment without start detected!\n"); } else { /* OK: Continue reassembly */ /* memcpy the data */ tvb_memcpy(tvb, l2p->data + l2p->rx_count, 4, length); l2p->rx_count += length; } } if (l2p) { if (l2p->rx_count > 1) /* We have collected enough bytes */ l2p->pkt_len = (l2p->data[1] << 8) + l2p->data[0] + 4; if (l2p->rx_count > l2p->pkt_len) { fprintf(stderr, "Packet too long!\n"); del_l2p(handle, 1); l2p = NULL; } else if (l2p->rx_count == l2p->pkt_len) { if (check_col(pinfo->cinfo, COL_INFO)) col_append_str(pinfo->cinfo, COL_INFO, " (End Fragment)"); del_l2p(handle, 0); /* save reassembled packet ???????? */ p_add_proto_data(pinfo->fd, proto_btacl, l2p); } else { /* Packet is not complete */ l2p = NULL; if (pb_flag == 1) { if (check_col(pinfo->cinfo, COL_INFO)) col_append_str(pinfo->cinfo, COL_INFO, " (Continuation Fragment)"); } } } } else { /* This is an additional pass */ /* Is there a reassembled packet saved ? */ l2p = p_get_proto_data(pinfo->fd, proto_btacl); } if (l2p) { next_tvb = tvb_new_real_data(l2p->data, l2p->pkt_len, l2p->pkt_len); //tvb_set_free_cb(next_tvb, g_free); tvb_set_child_real_data_tvbuff(tvb, next_tvb); add_new_data_source(pinfo, next_tvb, "Reassembled L2CAP"); /* call L2CAP dissector */ if(btl2cap_handle){ call_dissector(btl2cap_handle, next_tvb, pinfo, tree); } } #endif #if 0 /* decrypt successful, let's set up a new data tvb. */ decr_tvb = tvb_new_real_data(tmp, len-8, len-8); tvb_set_free_cb(decr_tvb, g_free); tvb_set_child_real_data_tvbuff(tvb, decr_tvb); #endif } 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", "btacl.chandle", FT_UINT16, BASE_HEX, NULL, 0x0FFF, "Connection Handle", HFILL } }, { &hf_btacl_pb_flag, { "PB Flag", "btacl.pb_flag", FT_UINT16, BASE_DEC, VALS(pb_flag_vals), 0x3000, "Packet Boundary Flag", HFILL } }, { &hf_btacl_bc_flag, { "BC Flag", "btacl.bc_flag", FT_UINT16, BASE_DEC, VALS(bc_flag_vals), 0xC000, "Broadcast Flag", HFILL } }, { &hf_btacl_length, { "Data Total Length", "btacl.length", FT_UINT16, BASE_DEC, NULL, 0x0, "Data Total Length", HFILL } }, { &hf_btacl_data, { "Data", "btacl.data", FT_NONE, BASE_NONE, NULL, 0x0, "Data", HFILL } }, }; /* Setup protocol subtree array */ static gint *ett[] = { &ett_btacl, }; /* 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)); } void proto_reg_handoff_btacl(void) { dissector_handle_t bthci_acl_handle; bthci_acl_handle = find_dissector("bthci_acl"); dissector_add("hci_h4.type", HCI_H4_TYPE_ACL, bthci_acl_handle); btl2cap_handle = find_dissector("btl2cap"); }