/* packet-netrom.c * * Routines for Amateur Packet Radio protocol dissection * NET/ROM inter-node frames. * Copyright 2005,2006,2007,2008,2009,2010,2012 R.W. Stearn * * Wireshark - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * SPDX-License-Identifier: GPL-2.0-or-later */ /* * Information on the protocol drawn from: * * Protocol specification is at: * * ftp://ftp.ucsd.edu/hamradio/packet/tcpip/docs/netrom.ps.gz * * (yes, it's PostScript, and, yes, it's an FTP URL). * * Inspiration on how to build the dissector drawn from * packet-sdlc.c * packet-x25.c * packet-lapb.c * paket-gprs-llc.c * xdlc.c * with the base file built from README.developers. */ #include "config.h" #include #include #include #include void proto_register_netrom(void); void proto_reg_handoff_netrom(void); #define STRLEN 80 #define NETROM_MIN_SIZE 7 /* minimum payload for a routing packet */ #define NETROM_HEADER_SIZE 20 /* minimum payload for a normal packet */ #define NETROM_PROTOEXT 0x00 #define NETROM_CONNREQ 0x01 #define NETROM_CONNACK 0x02 #define NETROM_DISCREQ 0x03 #define NETROM_DISCACK 0x04 #define NETROM_INFO 0x05 #define NETROM_INFOACK 0x06 #define NETROM_MORE_FLAG 0x20 #define NETROM_NAK_FLAG 0x40 #define NETROM_CHOKE_FLAG 0x80 #define NETROM_PROTO_IP 0x0C /* Dissector handles */ static dissector_handle_t ip_handle; /* Initialize the protocol and registered fields */ static int proto_netrom; static int hf_netrom_src; static int hf_netrom_dst; static int hf_netrom_ttl; static int hf_netrom_my_cct_index; static int hf_netrom_my_cct_id; static int hf_netrom_your_cct_index; static int hf_netrom_your_cct_id; static int hf_netrom_n_r; static int hf_netrom_n_s; static int hf_netrom_type; static int hf_netrom_op; static int hf_netrom_more; static int hf_netrom_nak; static int hf_netrom_choke; static int hf_netrom_user; static int hf_netrom_node; static int hf_netrom_pwindow; static int hf_netrom_awindow; static int hf_netrom_mnemonic; /* * Structure containing pointers to hf_ values for various subfields of * the type field. */ typedef struct { int *hf_tf_op; int *hf_tf_more; int *hf_tf_nak; int *hf_tf_choke; } netrom_tf_items; static const netrom_tf_items netrom_type_items = { &hf_netrom_op, &hf_netrom_more, &hf_netrom_nak, &hf_netrom_choke }; static const value_string op_code_vals_abbrev[] = { { NETROM_PROTOEXT , "PROTOEXT"}, { NETROM_CONNREQ , "CONNREQ"}, { NETROM_CONNACK , "CONNACK"}, { NETROM_DISCREQ , "DISCREQ"}, { NETROM_DISCACK , "DISCACK"}, { NETROM_INFO , "INFO"}, { NETROM_INFOACK , "INFOACK"}, { 0 , NULL} }; static const value_string op_code_vals_text[] = { { NETROM_PROTOEXT , "Protocol extension"}, { NETROM_CONNREQ , "Connect request"}, { NETROM_CONNACK , "Connect acknowledge"}, { NETROM_DISCREQ , "Disconnect request"}, { NETROM_DISCACK , "Disconnect acknowledge"}, { NETROM_INFO , "Information"}, { NETROM_INFOACK , "Information acknowledge"}, { 0 , NULL} }; /* Initialize the subtree pointers */ static gint ett_netrom; static gint ett_netrom_type; static void dissect_netrom_type(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree, int hf_netrom_type_param, gint ett_netrom_type_param, const netrom_tf_items *type_items ) { proto_tree *tc; proto_tree *type_tree; char *info_buffer; guint8 type; guint8 op_code; type = tvb_get_guint8( tvb, offset ); op_code = type &0x0f; info_buffer = wmem_strdup_printf( pinfo->pool, "%s%s%s%s (0x%02x)", val_to_str_const( op_code, op_code_vals_text, "Unknown" ), ( type & NETROM_MORE_FLAG ) ? ", More" : "", ( type & NETROM_NAK_FLAG ) ? ", NAK" : "", ( type & NETROM_CHOKE_FLAG ) ? ", Choke" : "", type ); col_add_str( pinfo->cinfo, COL_INFO, info_buffer ); if ( tree ) { tc = proto_tree_add_uint_format( tree, hf_netrom_type_param, tvb, offset, 1, type, "Type field: %s", info_buffer ); type_tree = proto_item_add_subtree( tc, ett_netrom_type_param ); proto_tree_add_item( type_tree, *type_items->hf_tf_op, tvb, offset, 1, ENC_BIG_ENDIAN ); proto_tree_add_item( type_tree, *type_items->hf_tf_choke, tvb, offset, 1, ENC_BIG_ENDIAN ); proto_tree_add_item( type_tree, *type_items->hf_tf_nak, tvb, offset, 1, ENC_BIG_ENDIAN ); proto_tree_add_item( type_tree, *type_items->hf_tf_more, tvb, offset, 1, ENC_BIG_ENDIAN ); } } static void dissect_netrom_proto(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) { proto_item *ti; proto_tree *netrom_tree; int offset; #if 0 guint8 src_ssid; guint8 dst_ssid; #endif guint8 op_code; guint8 cct_index; guint8 cct_id; tvbuff_t *next_tvb; col_set_str( pinfo->cinfo, COL_PROTOCOL, "NET/ROM" ); col_clear( pinfo->cinfo, COL_INFO ); offset = 0; /* source */ set_address_tvb(&pinfo->dl_src, AT_AX25, AX25_ADDR_LEN, tvb, offset); set_address_tvb(&pinfo->src, AT_AX25, AX25_ADDR_LEN, tvb, offset); /* src_ssid = tvb_get_guint8(tvb, offset+6); */ offset += AX25_ADDR_LEN; /* step over src addr */ /* destination */ set_address_tvb(&pinfo->dl_dst, AT_AX25, AX25_ADDR_LEN, tvb, offset); set_address_tvb(&pinfo->dst, AT_AX25, AX25_ADDR_LEN, tvb, offset); /* dst_ssid = tvb_get_guint8(tvb, offset+6); */ offset += AX25_ADDR_LEN; /* step over dst addr */ offset += 1; /* step over ttl */ cct_index = tvb_get_guint8( tvb, offset ); offset += 1; /* step over cct index*/ cct_id = tvb_get_guint8( tvb, offset ); offset += 1; /* step over cct id */ offset += 1; /* step over n_s */ offset += 1; /* step over n_r */ /* frame type */ op_code = tvb_get_guint8( tvb, offset ) & 0x0f; /*offset += 1;*/ /* step over op_code */ col_add_fstr( pinfo->cinfo, COL_INFO, "%s", val_to_str_const( op_code, op_code_vals_text, "Unknown" )); /* if ( tree ) */ { /* create display subtree for the protocol */ ti = proto_tree_add_protocol_format( tree, proto_netrom, tvb, 0, NETROM_HEADER_SIZE, "NET/ROM, Src: %s, Dst: %s", address_to_str(pinfo->pool, &pinfo->src), address_to_str(pinfo->pool, &pinfo->dst)); netrom_tree = proto_item_add_subtree( ti, ett_netrom ); offset = 0; /* source */ proto_tree_add_item( netrom_tree, hf_netrom_src, tvb, offset, AX25_ADDR_LEN, ENC_NA ); offset += AX25_ADDR_LEN; /* destination */ proto_tree_add_item( netrom_tree, hf_netrom_dst, tvb, offset, AX25_ADDR_LEN, ENC_NA ); offset += AX25_ADDR_LEN; /* ttl */ proto_tree_add_item( netrom_tree, hf_netrom_ttl, tvb, offset, 1, ENC_BIG_ENDIAN ); offset += 1; switch ( op_code ) { case NETROM_PROTOEXT : /* cct index */ proto_tree_add_item( netrom_tree, hf_netrom_my_cct_index, tvb, offset, 1, ENC_BIG_ENDIAN ); offset += 1; /* cct id */ proto_tree_add_item( netrom_tree, hf_netrom_my_cct_id, tvb, offset, 1, ENC_BIG_ENDIAN ); offset += 1; /* unused */ offset += 1; /* unused */ offset += 1; break; case NETROM_CONNREQ : /* cct index */ proto_tree_add_item( netrom_tree, hf_netrom_my_cct_index, tvb, offset, 1, ENC_BIG_ENDIAN ); offset += 1; /* cct id */ proto_tree_add_item( netrom_tree, hf_netrom_my_cct_id, tvb, offset, 1, ENC_BIG_ENDIAN ); offset += 1; /* unused */ offset += 1; /* unused */ offset += 1; break; case NETROM_CONNACK : /* your cct index */ proto_tree_add_item( netrom_tree, hf_netrom_your_cct_index, tvb, offset, 1, ENC_BIG_ENDIAN ); offset += 1; /* your cct id */ proto_tree_add_item( netrom_tree, hf_netrom_your_cct_id, tvb, offset, 1, ENC_BIG_ENDIAN ); offset += 1; /* my cct index */ proto_tree_add_item( netrom_tree, hf_netrom_my_cct_index, tvb, offset, 1, ENC_BIG_ENDIAN ); offset += 1; /* my cct id */ proto_tree_add_item( netrom_tree, hf_netrom_my_cct_id, tvb, offset, 1, ENC_BIG_ENDIAN ); offset += 1; break; case NETROM_DISCREQ : /* your cct index */ proto_tree_add_item( netrom_tree, hf_netrom_your_cct_index, tvb, offset, 1, ENC_BIG_ENDIAN ); offset += 1; /* your cct id */ proto_tree_add_item( netrom_tree, hf_netrom_your_cct_id, tvb, offset, 1, ENC_BIG_ENDIAN ); offset += 1; /* unused */ offset += 1; /* unused */ offset += 1; break; case NETROM_DISCACK : /* your cct index */ proto_tree_add_item( netrom_tree, hf_netrom_your_cct_index, tvb, offset, 1, ENC_BIG_ENDIAN ); offset += 1; /* your cct id */ proto_tree_add_item( netrom_tree, hf_netrom_your_cct_id, tvb, offset, 1, ENC_BIG_ENDIAN ); offset += 1; /* unused */ offset += 1; /* unused */ offset += 1; break; case NETROM_INFO : /* your cct index */ proto_tree_add_item( netrom_tree, hf_netrom_your_cct_index, tvb, offset, 1, ENC_BIG_ENDIAN ); offset += 1; /* your cct id */ proto_tree_add_item( netrom_tree, hf_netrom_your_cct_id, tvb, offset, 1, ENC_BIG_ENDIAN ); offset += 1; /* n_s */ proto_tree_add_item( netrom_tree, hf_netrom_n_s, tvb, offset, 1, ENC_BIG_ENDIAN ); offset += 1; /* n_r */ proto_tree_add_item( netrom_tree, hf_netrom_n_r, tvb, offset, 1, ENC_BIG_ENDIAN ); offset += 1; break; case NETROM_INFOACK : /* your cct index */ proto_tree_add_item( netrom_tree, hf_netrom_your_cct_index, tvb, offset, 1, ENC_BIG_ENDIAN ); offset += 1; /* your cct id */ proto_tree_add_item( netrom_tree, hf_netrom_your_cct_id, tvb, offset, 1, ENC_BIG_ENDIAN ); offset += 1; /* unused */ offset += 1; /* n_r */ proto_tree_add_item( netrom_tree, hf_netrom_n_r, tvb, offset, 1, ENC_BIG_ENDIAN ); offset += 1; break; default : offset += 1; offset += 1; offset += 1; offset += 1; break; } /* type */ dissect_netrom_type( tvb, offset, pinfo, netrom_tree, hf_netrom_type, ett_netrom_type, &netrom_type_items ); offset += 1; switch ( op_code ) { case NETROM_PROTOEXT : break; case NETROM_CONNREQ : /* proposed window size */ proto_tree_add_item( netrom_tree, hf_netrom_pwindow, tvb, offset, 1, ENC_BIG_ENDIAN ); offset += 1; proto_tree_add_item( netrom_tree, hf_netrom_user, tvb, offset, AX25_ADDR_LEN, ENC_NA ); offset += AX25_ADDR_LEN; proto_tree_add_item( netrom_tree, hf_netrom_node, tvb, offset, AX25_ADDR_LEN, ENC_NA ); offset += AX25_ADDR_LEN; break; case NETROM_CONNACK : /* accepted window size */ proto_tree_add_item( netrom_tree, hf_netrom_awindow, tvb, offset, 1, ENC_BIG_ENDIAN ); offset += 1; break; case NETROM_DISCREQ : break; case NETROM_DISCACK : break; case NETROM_INFO : break; case NETROM_INFOACK : break; default : break; } } /* Call sub-dissectors here */ next_tvb = tvb_new_subset_remaining(tvb, offset); switch ( op_code ) { case NETROM_PROTOEXT : if ( cct_index == NETROM_PROTO_IP && cct_id == NETROM_PROTO_IP ) call_dissector( ip_handle , next_tvb, pinfo, tree ); else call_data_dissector(next_tvb, pinfo, tree ); break; case NETROM_INFO : default : call_data_dissector(next_tvb, pinfo, tree ); break; } } static void dissect_netrom_routing(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) { tvbuff_t *next_tvb; const guint8* mnemonic; gint mnemonic_len; col_set_str( pinfo->cinfo, COL_PROTOCOL, "NET/ROM"); col_set_str( pinfo->cinfo, COL_INFO, "routing table frame"); if (tree) { proto_item *ti; proto_tree *netrom_tree; ti = proto_tree_add_item( tree, proto_netrom, tvb, 0, -1, ENC_NA); netrom_tree = proto_item_add_subtree( ti, ett_netrom ); proto_tree_add_item_ret_string_and_length(netrom_tree, hf_netrom_mnemonic, tvb, 1, 6, ENC_ASCII|ENC_NA, pinfo->pool, &mnemonic, &mnemonic_len); proto_item_append_text(ti, ", routing table frame, Node: %s", mnemonic); } next_tvb = tvb_new_subset_remaining(tvb, 7); call_data_dissector(next_tvb, pinfo, tree ); } /* Code to actually dissect the packets */ static int dissect_netrom(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) { if ( tvb_get_guint8( tvb, 0 ) == 0xff ) dissect_netrom_routing( tvb, pinfo, tree ); else dissect_netrom_proto( tvb, pinfo, tree ); return tvb_captured_length(tvb); } static gboolean capture_netrom( const guchar *pd _U_, int offset, int len, capture_packet_info_t *cpinfo _U_, const union wtap_pseudo_header *pseudo_header _U_) { if ( ! BYTES_ARE_IN_FRAME( offset, len, NETROM_MIN_SIZE ) ) return FALSE; /* XXX - check for IP-over-NetROM here! */ return FALSE; } void proto_register_netrom(void) { /* Setup list of header fields */ static hf_register_info hf[] = { { &hf_netrom_src, { "Source", "netrom.src", FT_AX25, BASE_NONE, NULL, 0x0, "Source callsign", HFILL } }, { &hf_netrom_dst, { "Destination", "netrom.dst", FT_AX25, BASE_NONE, NULL, 0x0, "Destination callsign", HFILL } }, { &hf_netrom_ttl, { "TTL", "netrom.ttl", FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL } }, { &hf_netrom_my_cct_index, { "My circuit index", "netrom.my.cct.index", FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL } }, { &hf_netrom_my_cct_id, { "My circuit ID", "netrom.my.cct.id", FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL } }, { &hf_netrom_your_cct_index, { "Your circuit index", "netrom.your.cct.index", FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL } }, { &hf_netrom_your_cct_id, { "Your circuit ID", "netrom.your.cct.id", FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL } }, { &hf_netrom_n_r, { "N(r)", "netrom.n_r", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL } }, { &hf_netrom_n_s, { "N(s)", "netrom.n_s", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL } }, { &hf_netrom_type, { "Type", "netrom.type", FT_UINT8, BASE_HEX, NULL, 0x0, "Packet type field", HFILL } }, { &hf_netrom_op, { "OP code", "netrom.op", FT_UINT8, BASE_HEX, VALS( op_code_vals_abbrev ), 0x0f, "Protocol operation code", HFILL } }, { &hf_netrom_more, { "More", "netrom.flag.more", FT_BOOLEAN, 8, TFS(&tfs_set_notset), NETROM_MORE_FLAG, "More flag", HFILL } }, { &hf_netrom_nak, { "NAK", "netrom.flag.nak", FT_BOOLEAN, 8, TFS(&tfs_set_notset), NETROM_NAK_FLAG, "NAK flag", HFILL } }, { &hf_netrom_choke, { "Choke", "netrom.flag.choke", FT_BOOLEAN, 8, TFS(&tfs_set_notset), NETROM_CHOKE_FLAG, "Choke flag", HFILL } }, { &hf_netrom_user, { "User", "netrom.user", FT_AX25, BASE_NONE, NULL, 0x0, "User callsign", HFILL } }, { &hf_netrom_node, { "Node", "netrom.node", FT_AX25, BASE_NONE, NULL, 0x0, "Node callsign", HFILL } }, { &hf_netrom_pwindow, { "Window", "netrom.pwindow", FT_UINT8, BASE_DEC, NULL, 0x0, "Proposed window", HFILL } }, { &hf_netrom_awindow, { "Window", "netrom.awindow", FT_UINT8, BASE_DEC, NULL, 0x0, "Accepted window", HFILL } }, { &hf_netrom_mnemonic, { "Node name", "netrom.name", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL } }, }; /* Setup protocol subtree array */ static gint *ett[] = { &ett_netrom, &ett_netrom_type, }; /* Register the protocol name and description */ proto_netrom = proto_register_protocol( "Amateur Radio NET/ROM", "NET/ROM", "netrom" ); /* Required function calls to register the header fields and subtrees used */ proto_register_field_array( proto_netrom, hf, array_length(hf ) ); proto_register_subtree_array( ett, array_length( ett ) ); } void proto_reg_handoff_netrom(void) { capture_dissector_handle_t netrom_cap_handle; dissector_add_uint( "ax25.pid", AX25_P_NETROM, create_dissector_handle( dissect_netrom, proto_netrom ) ); netrom_cap_handle = create_capture_dissector_handle(capture_netrom, proto_netrom); capture_dissector_add_uint("ax25.pid", AX25_P_NETROM, netrom_cap_handle); ip_handle = find_dissector_add_dependency( "ip", proto_netrom ); } /* * Editor modelines - https://www.wireshark.org/tools/modelines.html * * Local variables: * c-basic-offset: 8 * tab-width: 8 * indent-tabs-mode: t * End: * * vi: set shiftwidth=8 tabstop=8 noexpandtab: * :indentSize=8:tabSize=8:noTabs=false: */