diff options
Diffstat (limited to 'epan/dissectors/packet-pw-eth.c')
| -rw-r--r-- | epan/dissectors/packet-pw-eth.c | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/epan/dissectors/packet-pw-eth.c b/epan/dissectors/packet-pw-eth.c new file mode 100644 index 00000000..aec7b662 --- /dev/null +++ b/epan/dissectors/packet-pw-eth.c @@ -0,0 +1,212 @@ +/* packet-pw-eth.c + * Routines for ethernet PW dissection: it should conform to RFC 4448. + * + * Copyright 2008 _FF_ + * + * Francesco Fondelli <francesco dot fondelli, gmail dot com> + * + * Wireshark - Network traffic analyzer + * By Gerald Combs <gerald@wireshark.org> + * Copyright 1998 Gerald Combs + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +#include "config.h" + +#include <epan/packet.h> +#include <epan/addr_resolv.h> + +#include "packet-mpls.h" + +void proto_register_pw_eth(void); +void proto_reg_handoff_pw_eth(void); + +static gint proto_pw_eth_cw = -1; +static gint proto_pw_eth_nocw = -1; +static gint proto_pw_eth_heuristic = -1; + +static gint ett_pw_eth = -1; + +static int hf_pw_eth = -1; +static int hf_pw_eth_cw = -1; +static int hf_pw_eth_cw_sequence_number = -1; + +static dissector_handle_t eth_withoutfcs_handle; +static dissector_handle_t pw_eth_handle_cw; +static dissector_handle_t pw_eth_handle_nocw; +static dissector_handle_t pw_eth_handle_heuristic; + +static int +dissect_pw_eth_cw(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) +{ + tvbuff_t *next_tvb; + guint16 sequence_number; + + if (tvb_reported_length_remaining(tvb, 0) < 4) { + return 0; + } + + if (dissect_try_cw_first_nibble(tvb, pinfo, tree)) + return tvb_captured_length(tvb); + + sequence_number = tvb_get_ntohs(tvb, 2); + + if (tree) { + proto_tree *pw_eth_tree; + proto_item *ti; + + ti = proto_tree_add_boolean(tree, hf_pw_eth_cw, + tvb, 0, 0, TRUE); + proto_item_set_hidden(ti); + ti = proto_tree_add_item(tree, proto_pw_eth_cw, + tvb, 0, 4, ENC_NA); + pw_eth_tree = proto_item_add_subtree(ti, ett_pw_eth); + + proto_tree_add_uint_format(pw_eth_tree, + hf_pw_eth_cw_sequence_number, + tvb, 2, 2, sequence_number, + "Sequence Number: %d", + sequence_number); + } + + next_tvb = tvb_new_subset_remaining(tvb, 4); + { + call_dissector(eth_withoutfcs_handle, next_tvb, pinfo, tree); + } + + return tvb_captured_length(tvb); +} + +static int +dissect_pw_eth_nocw(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) +{ + tvbuff_t *next_tvb; + + if (tree) { + proto_item *ti; + ti = proto_tree_add_boolean(tree, hf_pw_eth, tvb, 0, 0, TRUE); + proto_item_set_hidden(ti); + } + + next_tvb = tvb_new_subset_remaining(tvb, 0); + call_dissector(eth_withoutfcs_handle, next_tvb, pinfo, tree); + + return tvb_captured_length(tvb); +} + +/* + * FF: this function returns TRUE if the first 12 bytes in tvb looks like + * two valid ethernet addresses. FALSE otherwise. + */ +static gboolean +looks_like_plain_eth(tvbuff_t *tvb _U_) +{ + const gchar *manuf_name_da; + const gchar *manuf_name_sa; + + if (tvb_reported_length_remaining(tvb, 0) < 14) { + return FALSE; + } + + manuf_name_da = tvb_get_manuf_name_if_known(tvb, 0); + manuf_name_sa = tvb_get_manuf_name_if_known(tvb, 6); + + if (manuf_name_da && manuf_name_sa) { + return TRUE; + } + + return FALSE; +} + +static int +dissect_pw_eth_heuristic(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) +{ + guint8 first_nibble = (tvb_get_guint8(tvb, 0) >> 4) & 0x0F; + + if (looks_like_plain_eth(tvb)) + call_dissector(pw_eth_handle_nocw, tvb, pinfo, tree); + else if (first_nibble == 0) + call_dissector(pw_eth_handle_cw, tvb, pinfo, tree); + else + call_dissector(pw_eth_handle_nocw, tvb, pinfo, tree); + return tvb_captured_length(tvb); +} + +void +proto_register_pw_eth(void) +{ + static hf_register_info hf[] = { + { + &hf_pw_eth, + { + "PW (ethernet)", + "pweth", FT_BOOLEAN, + BASE_NONE, NULL, 0x0, NULL, HFILL + } + }, + { + &hf_pw_eth_cw, + { + "PW Control Word (ethernet)", + "pweth.cw", FT_BOOLEAN, + BASE_NONE, NULL, 0x0, NULL, HFILL + } + }, + { + &hf_pw_eth_cw_sequence_number, + { + "PW sequence number (ethernet)", + "pweth.cw.sequence_number", FT_UINT16, + BASE_DEC, NULL, 0x0, NULL, HFILL + } + } + }; + + static gint *ett[] = { + &ett_pw_eth + }; + + proto_pw_eth_cw = + proto_register_protocol("PW Ethernet Control Word", + "Ethernet PW (with CW)", + "pwethcw"); + proto_pw_eth_nocw = + proto_register_protocol("Ethernet PW (no CW)", /* not displayed */ + "Ethernet PW (no CW)", + "pwethnocw"); + proto_pw_eth_heuristic = + proto_register_protocol("Ethernet PW (CW heuristic)", /* not disp. */ + "Ethernet PW (CW heuristic)", + "pwethheuristic"); + proto_register_field_array(proto_pw_eth_cw, hf, array_length(hf)); + proto_register_subtree_array(ett, array_length(ett)); + pw_eth_handle_cw = register_dissector("pw_eth_cw", dissect_pw_eth_cw, proto_pw_eth_cw); + pw_eth_handle_nocw = register_dissector("pw_eth_nocw", dissect_pw_eth_nocw, proto_pw_eth_nocw); + pw_eth_handle_heuristic = register_dissector("pw_eth_heuristic", dissect_pw_eth_heuristic, + proto_pw_eth_heuristic); +} + +void +proto_reg_handoff_pw_eth(void) +{ + eth_withoutfcs_handle = find_dissector_add_dependency("eth_withoutfcs", proto_pw_eth_cw); + + dissector_add_for_decode_as("mpls.label", pw_eth_handle_cw); + dissector_add_for_decode_as("mpls.label", pw_eth_handle_nocw); + + dissector_add_for_decode_as("mpls.label", pw_eth_handle_heuristic); +} + +/* + * Editor modelines - https://www.wireshark.org/tools/modelines.html + * + * Local variables: + * c-basic-offset: 4 + * tab-width: 8 + * indent-tabs-mode: nil + * End: + * + * vi: set shiftwidth=4 tabstop=8 expandtab: + * :indentSize=4:tabSize=8:noTabs=true: + */ |