/* packet-whois.c * Routines for whois dissection (see https://tools.ietf.org/html/rfc3912) * Copyright 2013, Christopher Maynard * * Wireshark - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * SPDX-License-Identifier: GPL-2.0-or-later */ #include "config.h" #include #include #include #include "packet-tcp.h" #define WHOIS_PORT 43 /* This is the registered IANA port (nicname) */ void proto_register_whois(void); void proto_reg_handoff_whois(void); static int proto_whois = -1; static int hf_whois_query = -1; static int hf_whois_answer = -1; static int hf_whois_answer_in = -1; static int hf_whois_answer_to = -1; static int hf_whois_response_time = -1; static expert_field ei_whois_nocrlf = EI_INIT; static expert_field ei_whois_encoding = EI_INIT; static gint ett_whois = -1; typedef struct _whois_transaction_t { guint32 req_frame; guint32 rep_frame; nstime_t req_time; guint8* query; } whois_transaction_t; static int dissect_whois(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data) { proto_item *ti, *expert_ti; proto_tree *whois_tree; conversation_t *conversation; whois_transaction_t *whois_trans; gboolean is_query; guint len; struct tcpinfo *tcpinfo = (struct tcpinfo*)data; col_set_str(pinfo->cinfo, COL_PROTOCOL, "WHOIS"); if (pinfo->destport == WHOIS_PORT) { is_query = TRUE; col_set_str(pinfo->cinfo, COL_INFO, "Query"); } else { is_query = FALSE; col_set_str(pinfo->cinfo, COL_INFO, "Answer"); } conversation = find_or_create_conversation(pinfo); whois_trans = (whois_transaction_t *)conversation_get_proto_data(conversation, proto_whois); if (whois_trans == NULL) { gint linelen; whois_trans = wmem_new0(wmem_file_scope(), whois_transaction_t); /* * Find the end of the first line. */ linelen = tvb_find_line_end(tvb, 0, -1, NULL, FALSE); if (linelen != -1) whois_trans->query = tvb_get_string_enc(wmem_file_scope(), tvb, 0, linelen, ENC_ASCII|ENC_NA); conversation_add_proto_data(conversation, proto_whois, whois_trans); } if (whois_trans->query) { col_append_str(pinfo->cinfo, COL_INFO, ": "); col_append_str(pinfo->cinfo, COL_INFO, whois_trans->query); } len = tvb_reported_length(tvb); if (!PINFO_FD_VISITED(pinfo)) { if (pinfo->can_desegment) { if (is_query) { if ((len < 2) || (tvb_memeql(tvb, len - 2, (const guint8*)"\r\n", 2))) { pinfo->desegment_len = DESEGMENT_ONE_MORE_SEGMENT; pinfo->desegment_offset = 0; return -1; } else { whois_trans->req_frame = pinfo->num; whois_trans->req_time = pinfo->abs_ts; } } else if (!(tcpinfo && (IS_TH_FIN(tcpinfo->flags) || tcpinfo->is_reassembled))) { /* If this is the FIN (or already desegmented, as with an out * of order segment received after FIN) go ahead and dissect * on the first pass. */ pinfo->desegment_len = DESEGMENT_UNTIL_FIN; pinfo->desegment_offset = 0; return -1; } } } else if (is_query && (whois_trans->req_frame == 0)) { whois_trans->req_frame = pinfo->num; whois_trans->req_time = pinfo->abs_ts; } if (!is_query && (whois_trans->rep_frame == 0)) { /* By comparing whois_trans->rep_frame to 0, if reassembly is turned * on, whois_trans->rep_frame will be assigned to the reassembled frame * number, and if reassembly is turned off, whois_trans->rep_frame will * be assigned to the first frame number of the response. This seems * to match other protocols' behavior. The alternative is: * if (pinfo->num > whois_trans->rep_frame) * which will give us the same frame number either way. */ whois_trans->rep_frame = pinfo->num; } ti = proto_tree_add_protocol_format(tree, proto_whois, tvb, 0, -1, "WHOIS: %s", is_query ? "Query" : "Answer"); whois_tree = proto_item_add_subtree(ti, ett_whois); /* * XXX - WHOIS, as RFC 3912 says, "has no mechanism for indicating * the character set in use." We assume UTF-8, which is backwards * compatible with ASCII; if somebody wants to support WHOIS requests * or responses in other encodings, they should add a preference. * (Show Packet Bytes works well enough for many use cases.) * Some servers do use other character encodings; * e.g., in 2022 RIPE still uses ISO-8859-1. */ if (is_query) { expert_ti = proto_tree_add_item(whois_tree, hf_whois_query, tvb, 0, -1, ENC_ASCII); if ((len < 2) || (tvb_memeql(tvb, len - 2, (const guint8*)"\r\n", 2))) { /* * From RFC3912, section 2: * All requests are terminated with ASCII CR and then ASCII LF. */ expert_add_info(pinfo, expert_ti, &ei_whois_nocrlf); } if (tree && whois_trans->rep_frame) { ti = proto_tree_add_uint(whois_tree, hf_whois_answer_in, tvb, 0, 0, whois_trans->rep_frame); proto_item_set_generated(ti); } } else if (tree && whois_trans->rep_frame) { /* * If we know the request frame, show it and the time delta between * the request and the response. */ if (whois_trans->req_frame) { nstime_t ns; ti = proto_tree_add_uint(whois_tree, hf_whois_answer_to, tvb, 0, 0, whois_trans->req_frame); proto_item_set_generated(ti); if (pinfo->num == whois_trans->rep_frame) { nstime_delta(&ns, &pinfo->abs_ts, &whois_trans->req_time); ti = proto_tree_add_time(whois_tree, hf_whois_response_time, tvb, 0, 0, &ns); proto_item_set_generated(ti); } } /* * Show the response as text, a line at a time. */ int offset = 0, next_offset; while (tvb_offset_exists(tvb, offset)) { /* * Find the end of the line. */ tvb_find_line_end(tvb, offset, -1, &next_offset, FALSE); /* * Put this line. */ proto_tree_add_item(whois_tree, hf_whois_answer, tvb, offset, next_offset - offset, ENC_UTF_8); offset = next_offset; } proto_tree_add_expert(whois_tree, pinfo, &ei_whois_encoding, tvb, 0, -1); } return tvb_captured_length(tvb); } void proto_register_whois(void) { expert_module_t *expert_whois; static hf_register_info hf[] = { { &hf_whois_query, { "Query", "whois.query", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL } }, { &hf_whois_answer, { "Answer", "whois.answer", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL } }, { &hf_whois_answer_in, { "Answer In", "whois.answer_in", FT_FRAMENUM, BASE_NONE, NULL, 0x0, "The answer to this WHOIS query is in this frame", HFILL } }, { &hf_whois_answer_to, { "Query In", "whois.answer_to", FT_FRAMENUM, BASE_NONE, NULL, 0x0, "This is the answer to the WHOIS query in this frame", HFILL } }, { &hf_whois_response_time, { "Response Time", "whois.response_time", FT_RELATIVE_TIME, BASE_NONE, NULL, 0x0, "The time between the Query and the Answer", HFILL } } }; static gint *ett[] = { &ett_whois }; static ei_register_info ei[] = { { &ei_whois_nocrlf, { "whois.nocrlf", PI_MALFORMED, PI_WARN, "Missing ", EXPFILL} }, { &ei_whois_encoding, { "whois.encoding", PI_ASSUMPTION, PI_CHAT, "WHOIS has no mechanism to indicate encoding (RFC 3912), assuming UTF-8", EXPFILL} } }; proto_whois = proto_register_protocol("whois", "WHOIS", "whois"); proto_register_field_array(proto_whois, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); expert_whois = expert_register_protocol(proto_whois); expert_register_field_array(expert_whois, ei, array_length(ei)); } void proto_reg_handoff_whois(void) { static dissector_handle_t whois_handle; whois_handle = create_dissector_handle(dissect_whois, proto_whois); dissector_add_uint_with_preference("tcp.port", WHOIS_PORT, whois_handle); } /* * 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: */