/* * Copyright (C) 2011-2015 Andreas Steffen * HSR Hochschule fuer Technik Rapperswil * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation; either version 2 of the License, or (at your * option) any later version. See . * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * for more details. */ #include "imc_scanner_state.h" #include #include #include #include #include #include #include #include #include #include /* IMC definitions */ static const char imc_name[] = "Scanner"; static pen_type_t msg_types[] = { { PEN_IETF, PA_SUBTYPE_IETF_FIREWALL } }; static imc_agent_t *imc_scanner; /** * see section 3.8.1 of TCG TNC IF-IMC Specification 1.3 */ TNC_Result TNC_IMC_Initialize(TNC_IMCID imc_id, TNC_Version min_version, TNC_Version max_version, TNC_Version *actual_version) { if (imc_scanner) { DBG1(DBG_IMC, "IMC \"%s\" has already been initialized", imc_name); return TNC_RESULT_ALREADY_INITIALIZED; } imc_scanner = imc_agent_create(imc_name, msg_types, countof(msg_types), imc_id, actual_version); if (!imc_scanner) { return TNC_RESULT_FATAL; } if (min_version > TNC_IFIMC_VERSION_1 || max_version < TNC_IFIMC_VERSION_1) { DBG1(DBG_IMC, "no common IF-IMC version"); return TNC_RESULT_NO_COMMON_VERSION; } return TNC_RESULT_SUCCESS; } /** * see section 3.8.2 of TCG TNC IF-IMC Specification 1.3 */ TNC_Result TNC_IMC_NotifyConnectionChange(TNC_IMCID imc_id, TNC_ConnectionID connection_id, TNC_ConnectionState new_state) { imc_state_t *state; if (!imc_scanner) { DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name); return TNC_RESULT_NOT_INITIALIZED; } switch (new_state) { case TNC_CONNECTION_STATE_CREATE: state = imc_scanner_state_create(connection_id); return imc_scanner->create_state(imc_scanner, state); case TNC_CONNECTION_STATE_HANDSHAKE: if (imc_scanner->change_state(imc_scanner, connection_id, new_state, &state) != TNC_RESULT_SUCCESS) { return TNC_RESULT_FATAL; } state->set_result(state, imc_id, TNC_IMV_EVALUATION_RESULT_DONT_KNOW); return TNC_RESULT_SUCCESS; case TNC_CONNECTION_STATE_DELETE: return imc_scanner->delete_state(imc_scanner, connection_id); default: return imc_scanner->change_state(imc_scanner, connection_id, new_state, NULL); } } /** * Determine all TCP and UDP server sockets listening on physical interfaces */ static bool do_netstat(ietf_attr_port_filter_t *attr) { FILE *file; char buf[BUF_LEN]; chunk_t line, token; int n = 0; bool success = FALSE; const char system_v4[] = "127.0.1.1"; const char loopback_v4[] = "127.0.0.1"; const char loopback_v6[] = "::1"; /* Open a pipe stream for reading the output of the netstat commmand */ file = popen("/bin/netstat -n -l -p -4 -6 --inet", "r"); if (!file) { DBG1(DBG_IMC, "failed to run netstat command"); return FALSE; } /* Read the output a line at a time */ while (fgets(buf, sizeof(buf), file)) { u_char *pos; uint8_t new_protocol, protocol; uint16_t new_port, port; int i; enumerator_t *enumerator; bool allowed, found = FALSE; DBG2(DBG_IMC, "%.*s", (int)(strlen(buf)-1), buf); if (n++ < 2) { /* skip the first two header lines */ continue; } line = chunk_create(buf, strlen(buf)); /* Extract the IP protocol type */ if (!extract_token(&token, ' ', &line)) { DBG1(DBG_IMC, "protocol field in netstat output not found"); goto end; } if (match("tcp", &token) || match("tcp6", &token)) { new_protocol = IPPROTO_TCP; } else if (match("udp", &token) || match("udp6", &token)) { new_protocol = IPPROTO_UDP; } else { DBG1(DBG_IMC, "skipped unknown IP protocol in netstat output"); continue; } /* Skip the Recv-Q and Send-Q fields */ for (i = 0; i < 3; i++) { if (!eat_whitespace(&line) || !extract_token(&token, ' ', &line)) { token = chunk_empty; break; } } if (token.len == 0) { DBG1(DBG_IMC, "local address field in netstat output not found"); goto end; } /* Find the local port appended to the local address */ pos = token.ptr + token.len; while (*--pos != ':' && --token.len); if (*pos != ':') { DBG1(DBG_IMC, "local port field in netstat output not found"); goto end; } token.len--; /* ignore ports of IPv4 and IPv6 loopback interfaces and the internal system IPv4 address */ if ((token.len == strlen(system_v4) && memeq(system_v4, token.ptr, token.len)) || (token.len == strlen(loopback_v4) && memeq(loopback_v4, token.ptr, token.len)) || (token.len == strlen(loopback_v6) && memeq(loopback_v6, token.ptr, token.len))) { continue; } /* convert the port string to an integer */ new_port = atoi(pos+1); /* check if the there is already a port entry */ enumerator = attr->create_port_enumerator(attr); while (enumerator->enumerate(enumerator, &allowed, &protocol, &port)) { if (new_port == port && new_protocol == protocol) { found = TRUE; } } enumerator->destroy(enumerator); /* Skip the duplicate port entry */ if (found) { continue; } /* Add new port entry */ attr->add_port(attr, FALSE, new_protocol, new_port); } /* Successfully completed the parsing of the netstat output */ success = TRUE; end: /* Close the pipe stream */ pclose(file); return success; } /** * Add IETF Port Filter attribute to the send queue */ static TNC_Result add_port_filter(imc_msg_t *msg) { pa_tnc_attr_t *attr; ietf_attr_port_filter_t *attr_port_filter; attr = ietf_attr_port_filter_create(pen_type_create(PEN_IETF, IETF_ATTR_PORT_FILTER)); attr->set_noskip_flag(attr, TRUE); attr_port_filter = (ietf_attr_port_filter_t*)attr; if (!do_netstat(attr_port_filter)) { attr->destroy(attr); return TNC_RESULT_FATAL; } msg->add_attribute(msg, attr); return TNC_RESULT_SUCCESS; } /** * see section 3.8.3 of TCG TNC IF-IMC Specification 1.3 */ TNC_Result TNC_IMC_BeginHandshake(TNC_IMCID imc_id, TNC_ConnectionID connection_id) { imc_state_t *state; imc_msg_t *out_msg; TNC_Result result = TNC_RESULT_SUCCESS; if (!imc_scanner) { DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name); return TNC_RESULT_NOT_INITIALIZED; } if (!imc_scanner->get_state(imc_scanner, connection_id, &state)) { return TNC_RESULT_FATAL; } if (lib->settings->get_bool(lib->settings, "%s.plugins.imc-scanner.push_info", TRUE, lib->ns)) { out_msg = imc_msg_create(imc_scanner, state, connection_id, imc_id, TNC_IMVID_ANY, msg_types[0]); result = add_port_filter(out_msg); if (result == TNC_RESULT_SUCCESS) { /* send PA-TNC message with the excl flag not set */ result = out_msg->send(out_msg, FALSE); } out_msg->destroy(out_msg); } return result; } static TNC_Result receive_message(imc_msg_t *in_msg) { imc_msg_t *out_msg; enumerator_t *enumerator; pa_tnc_attr_t *attr; pen_type_t attr_type; TNC_Result result = TNC_RESULT_SUCCESS; bool fatal_error = FALSE; /* generate an outgoing PA-TNC message - we might need it */ out_msg = imc_msg_create_as_reply(in_msg); /* parse received PA-TNC message and handle local and remote errors */ result = in_msg->receive(in_msg, out_msg, &fatal_error); if (result != TNC_RESULT_SUCCESS) { out_msg->destroy(out_msg); return result; } /* analyze PA-TNC attributes */ enumerator = in_msg->create_attribute_enumerator(in_msg); while (enumerator->enumerate(enumerator, &attr)) { attr_type = attr->get_type(attr); if (attr_type.vendor_id != PEN_IETF) { continue; } if (attr_type.type == IETF_ATTR_ATTRIBUTE_REQUEST) { ietf_attr_attr_request_t *attr_cast; pen_type_t *entry; enumerator_t *e; attr_cast = (ietf_attr_attr_request_t*)attr; e = attr_cast->create_enumerator(attr_cast); while (e->enumerate(e, &entry)) { if (entry->vendor_id != PEN_IETF) { continue; } switch (entry->type) { case IETF_ATTR_PORT_FILTER: result = add_port_filter(out_msg); break; default: break; } } e->destroy(e); } } enumerator->destroy(enumerator); if (fatal_error) { result = TNC_RESULT_FATAL; } else if (result == TNC_RESULT_SUCCESS) { /* send PA-TNC message with the EXCL flag set */ result = out_msg->send(out_msg, TRUE); } out_msg->destroy(out_msg); return result; } /** * see section 3.8.4 of TCG TNC IF-IMC Specification 1.3 */ TNC_Result TNC_IMC_ReceiveMessage(TNC_IMCID imc_id, TNC_ConnectionID connection_id, TNC_BufferReference msg, TNC_UInt32 msg_len, TNC_MessageType msg_type) { imc_state_t *state; imc_msg_t *in_msg; TNC_Result result; if (!imc_scanner) { DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name); return TNC_RESULT_NOT_INITIALIZED; } if (!imc_scanner->get_state(imc_scanner, connection_id, &state)) { return TNC_RESULT_FATAL; } in_msg = imc_msg_create_from_data(imc_scanner, state, connection_id, msg_type, chunk_create(msg, msg_len)); result = receive_message(in_msg); in_msg->destroy(in_msg); return result; } /** * see section 3.8.6 of TCG TNC IF-IMV Specification 1.3 */ TNC_Result TNC_IMC_ReceiveMessageLong(TNC_IMCID imc_id, TNC_ConnectionID connection_id, TNC_UInt32 msg_flags, TNC_BufferReference msg, TNC_UInt32 msg_len, TNC_VendorID msg_vid, TNC_MessageSubtype msg_subtype, TNC_UInt32 src_imv_id, TNC_UInt32 dst_imc_id) { imc_state_t *state; imc_msg_t *in_msg; TNC_Result result; if (!imc_scanner) { DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name); return TNC_RESULT_NOT_INITIALIZED; } if (!imc_scanner->get_state(imc_scanner, connection_id, &state)) { return TNC_RESULT_FATAL; } in_msg = imc_msg_create_from_long_data(imc_scanner, state, connection_id, src_imv_id, dst_imc_id, msg_vid, msg_subtype, chunk_create(msg, msg_len)); result = receive_message(in_msg); in_msg->destroy(in_msg); return result; } /** * see section 3.8.7 of TCG TNC IF-IMC Specification 1.3 */ TNC_Result TNC_IMC_BatchEnding(TNC_IMCID imc_id, TNC_ConnectionID connection_id) { if (!imc_scanner) { DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name); return TNC_RESULT_NOT_INITIALIZED; } return TNC_RESULT_SUCCESS; } /** * see section 3.8.8 of TCG TNC IF-IMC Specification 1.3 */ TNC_Result TNC_IMC_Terminate(TNC_IMCID imc_id) { if (!imc_scanner) { DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name); return TNC_RESULT_NOT_INITIALIZED; } imc_scanner->destroy(imc_scanner); imc_scanner = NULL; return TNC_RESULT_SUCCESS; } /** * see section 4.2.8.1 of TCG TNC IF-IMC Specification 1.3 */ TNC_Result TNC_IMC_ProvideBindFunction(TNC_IMCID imc_id, TNC_TNCC_BindFunctionPointer bind_function) { if (!imc_scanner) { DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name); return TNC_RESULT_NOT_INITIALIZED; } return imc_scanner->bind_functions(imc_scanner, bind_function); }