osmith
/
wireshark
forked from osmocom/wireshark
1
0
Fork 0
Code Pull Requests Releases Wiki Activity
wireshark/epan/dissectors/packet-netrom.c

627 lines
16 KiB
C
Raw Blame History

/* 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 <richard@rns-stearn.demon.co.uk>
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* 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 <epan/packet.h>
#include <epan/to_str.h>
#include <epan/capture_dissectors.h>
#include <epan/ax25_pids.h>
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 = -1;
static int hf_netrom_src = -1;
static int hf_netrom_dst = -1;
static int hf_netrom_ttl = -1;
static int hf_netrom_my_cct_index = -1;
static int hf_netrom_my_cct_id = -1;
static int hf_netrom_your_cct_index = -1;
static int hf_netrom_your_cct_id = -1;
static int hf_netrom_n_r = -1;
static int hf_netrom_n_s = -1;
static int hf_netrom_type = -1;
static int hf_netrom_op = -1;
static int hf_netrom_more = -1;
static int hf_netrom_nak = -1;
static int hf_netrom_choke = -1;
static int hf_netrom_user = -1;
static int hf_netrom_node = -1;
static int hf_netrom_pwindow = -1;
static int hf_netrom_awindow = -1;
static int hf_netrom_mnemonic = -1;
/*
* 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 = -1;
static gint ett_netrom_type = -1;
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:
*/
View Git Blame Copy Permalink