/* packet-finger.c * Routines for basic finger dissection (see https://tools.ietf.org/html/rfc742) * 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" void proto_register_finger(void); void proto_reg_handoff_finger(void); static dissector_handle_t finger_handle; #define FINGER_PORT 79 /* This is the registered IANA port */ static int proto_finger; static int hf_finger_query; static int hf_finger_response; static int hf_finger_response_in; static int hf_finger_response_to; static int hf_finger_response_time; static expert_field ei_finger_nocrlf; static int ett_finger; typedef struct _finger_transaction_t { uint32_t req_frame; uint32_t rep_frame; nstime_t req_time; } finger_transaction_t; static int dissect_finger(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data) { proto_item *ti, *expert_ti; proto_tree *finger_tree; conversation_t *conversation; finger_transaction_t *finger_trans; bool is_query; unsigned len; struct tcpinfo *tcpinfo = (struct tcpinfo*)data; col_set_str(pinfo->cinfo, COL_PROTOCOL, "FINGER"); if (pinfo->destport == FINGER_PORT) { is_query = true; col_set_str(pinfo->cinfo, COL_INFO, "Query"); } else { is_query = false; col_set_str(pinfo->cinfo, COL_INFO, "Response"); } conversation = find_or_create_conversation(pinfo); finger_trans = (finger_transaction_t *)conversation_get_proto_data(conversation, proto_finger); if (finger_trans == NULL) { finger_trans = wmem_new0(wmem_file_scope(), finger_transaction_t); conversation_add_proto_data(conversation, proto_finger, finger_trans); } 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 uint8_t*)"\r\n", 2))) { pinfo->desegment_len = DESEGMENT_ONE_MORE_SEGMENT; pinfo->desegment_offset = 0; return -1; } else { finger_trans->req_frame = pinfo->num; finger_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 && (finger_trans->req_frame == 0)) { finger_trans->req_frame = pinfo->num; finger_trans->req_time = pinfo->abs_ts; } if (!is_query && (finger_trans->rep_frame == 0)) { /* By comparing finger_trans->rep_frame to 0, if reassembly is turned * on, finger_trans->rep_frame will be assigned to the reassembled frame * number, and if reassembly is turned off, finger_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 > finger_trans->rep_frame) * which will give us the same frame number either way. */ finger_trans->rep_frame = pinfo->num; } ti = proto_tree_add_protocol_format(tree, proto_finger, tvb, 0, -1, "FINGER: %s", is_query ? "Query" : "Response"); finger_tree = proto_item_add_subtree(ti, ett_finger); if (is_query) { expert_ti = proto_tree_add_item(finger_tree, hf_finger_query, tvb, 0, -1, ENC_ASCII); if ((len < 2) || (tvb_memeql(tvb, len - 2, (const uint8_t*)"\r\n", 2))) { /* * From RFC742, Send a single "command line", ending with . */ expert_add_info(pinfo, expert_ti, &ei_finger_nocrlf); } if (tree && finger_trans->rep_frame) { ti = proto_tree_add_uint(finger_tree, hf_finger_response_in, tvb, 0, 0, finger_trans->rep_frame); proto_item_set_generated(ti); } } else if (tree && finger_trans->rep_frame) { proto_tree_add_item(finger_tree, hf_finger_response, tvb, 0, -1, ENC_ASCII); if (finger_trans->req_frame) { nstime_t ns; ti = proto_tree_add_uint(finger_tree, hf_finger_response_to, tvb, 0, 0, finger_trans->req_frame); proto_item_set_generated(ti); if (pinfo->num == finger_trans->rep_frame) { nstime_delta(&ns, &pinfo->abs_ts, &finger_trans->req_time); ti = proto_tree_add_time(finger_tree, hf_finger_response_time, tvb, 0, 0, &ns); proto_item_set_generated(ti); } } } return tvb_captured_length(tvb); } void proto_register_finger(void) { expert_module_t *expert_finger; static hf_register_info hf[] = { { &hf_finger_query, { "Query", "finger.query", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL } }, { &hf_finger_response, { "Response", "finger.response", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL } }, { &hf_finger_response_in, { "Response In", "finger.response_in", FT_FRAMENUM, BASE_NONE, NULL, 0x0, "The response to this FINGER query is in this frame", HFILL } }, { &hf_finger_response_to, { "Request In", "finger.response_to", FT_FRAMENUM, BASE_NONE, NULL, 0x0, "This is a response to the FINGER query in this frame", HFILL } }, { &hf_finger_response_time, { "Response Time", "finger.response_time", FT_RELATIVE_TIME, BASE_NONE, NULL, 0x0, "The time between the Query and the Response", HFILL } } }; static int *ett[] = { &ett_finger }; static ei_register_info ei[] = { { &ei_finger_nocrlf, { "finger.nocrlf", PI_MALFORMED, PI_WARN, "Missing ", EXPFILL} } }; proto_finger = proto_register_protocol("finger", "FINGER", "finger"); finger_handle = register_dissector("finger", dissect_finger, proto_finger); proto_register_field_array(proto_finger, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); expert_finger = expert_register_protocol(proto_finger); expert_register_field_array(expert_finger, ei, array_length(ei)); } void proto_reg_handoff_finger(void) { dissector_add_uint_with_preference("tcp.port", FINGER_PORT, finger_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: */