server_multicast.c 16 KB

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  1. /* This work is licensed under a Creative Commons CCZero 1.0 Universal License.
  2. * See http://creativecommons.org/publicdomain/zero/1.0/ for more information. */
  3. /*
  4. * A simple server instance which registers with the discovery server.
  5. * Compared to server_register.c this example waits until the LDS server announces
  6. * itself through mDNS. Therefore the LDS server needs to support multicast extension
  7. * (i.e., LDS-ME).
  8. */
  9. #include <signal.h>
  10. #include <stdio.h>
  11. #include <stdlib.h>
  12. #include <errno.h>
  13. #include "open62541.h"
  14. UA_Logger logger = UA_Log_Stdout;
  15. UA_Boolean running = true;
  16. const UA_ByteString
  17. UA_SECURITY_POLICY_BASIC128_URI = {56, (UA_Byte *)"http://opcfoundation.org/UA/SecurityPolicy#Basic128Rsa15"};
  18. static void stopHandler(int sign) {
  19. UA_LOG_INFO(logger, UA_LOGCATEGORY_SERVER, "received ctrl-c");
  20. running = false;
  21. }
  22. static UA_StatusCode
  23. readInteger(UA_Server *server, const UA_NodeId *sessionId,
  24. void *sessionContext, const UA_NodeId *nodeId,
  25. void *nodeContext, UA_Boolean includeSourceTimeStamp,
  26. const UA_NumericRange *range, UA_DataValue *value) {
  27. UA_Int32 *myInteger = (UA_Int32*)nodeContext;
  28. value->hasValue = true;
  29. UA_Variant_setScalarCopy(&value->value, myInteger, &UA_TYPES[UA_TYPES_INT32]);
  30. // we know the nodeid is a string
  31. UA_LOG_INFO(logger, UA_LOGCATEGORY_USERLAND, "Node read %.*s",
  32. (int)nodeId->identifier.string.length,
  33. nodeId->identifier.string.data);
  34. UA_LOG_INFO(logger, UA_LOGCATEGORY_USERLAND,
  35. "read value %i", *(UA_UInt32 *)myInteger);
  36. return UA_STATUSCODE_GOOD;
  37. }
  38. static UA_StatusCode
  39. writeInteger(UA_Server *server, const UA_NodeId *sessionId,
  40. void *sessionContext, const UA_NodeId *nodeId,
  41. void *nodeContext, const UA_NumericRange *range,
  42. const UA_DataValue *value) {
  43. UA_Int32 *myInteger = (UA_Int32*)nodeContext;
  44. if(value->hasValue && UA_Variant_isScalar(&value->value) &&
  45. value->value.type == &UA_TYPES[UA_TYPES_INT32] && value->value.data)
  46. *myInteger = *(UA_Int32 *)value->value.data;
  47. // we know the nodeid is a string
  48. UA_LOG_INFO(logger, UA_LOGCATEGORY_USERLAND, "Node written %.*s",
  49. (int)nodeId->identifier.string.length,
  50. nodeId->identifier.string.data);
  51. UA_LOG_INFO(logger, UA_LOGCATEGORY_USERLAND,
  52. "written value %i", *(UA_UInt32 *)myInteger);
  53. return UA_STATUSCODE_GOOD;
  54. }
  55. char *discovery_url = NULL;
  56. UA_String *self_discovery_url = NULL;
  57. static void
  58. serverOnNetworkCallback(const UA_ServerOnNetwork *serverOnNetwork, UA_Boolean isServerAnnounce,
  59. UA_Boolean isTxtReceived, void *data) {
  60. if(discovery_url != NULL || !isServerAnnounce) {
  61. UA_LOG_DEBUG(logger, UA_LOGCATEGORY_SERVER,
  62. "serverOnNetworkCallback called, but discovery URL "
  63. "already initialized or is not announcing. Ignoring.");
  64. return; // we already have everything we need or we only want server announces
  65. }
  66. if(self_discovery_url != NULL && UA_String_equal(&serverOnNetwork->discoveryUrl, self_discovery_url)) {
  67. // skip self
  68. return;
  69. }
  70. if(!isTxtReceived)
  71. return; // we wait until the corresponding TXT record is announced.
  72. // Problem: how to handle if a Server does not announce the
  73. // optional TXT?
  74. // here you can filter for a specific LDS server, e.g. call FindServers on
  75. // the serverOnNetwork to make sure you are registering with the correct
  76. // LDS. We will ignore this for now
  77. UA_LOG_INFO(logger, UA_LOGCATEGORY_SERVER, "Another server announced itself on %.*s",
  78. (int)serverOnNetwork->discoveryUrl.length, serverOnNetwork->discoveryUrl.data);
  79. if(discovery_url != NULL)
  80. UA_free(discovery_url);
  81. discovery_url = (char*)UA_malloc(serverOnNetwork->discoveryUrl.length + 1);
  82. memcpy(discovery_url, serverOnNetwork->discoveryUrl.data, serverOnNetwork->discoveryUrl.length);
  83. discovery_url[serverOnNetwork->discoveryUrl.length] = 0;
  84. }
  85. /*
  86. * Get the endpoint from the server, where we can call RegisterServer2 (or RegisterServer).
  87. * This is normally the endpoint with highest supported encryption mode.
  88. *
  89. * @param discoveryServerUrl The discovery url from the remote server
  90. * @return The endpoint description (which needs to be freed) or NULL
  91. */
  92. static
  93. UA_EndpointDescription *getRegisterEndpointFromServer(const char *discoveryServerUrl) {
  94. UA_Client *client = UA_Client_new(UA_ClientConfig_default);
  95. UA_EndpointDescription *endpointArray = NULL;
  96. size_t endpointArraySize = 0;
  97. UA_StatusCode retval = UA_Client_getEndpoints(client, discoveryServerUrl,
  98. &endpointArraySize, &endpointArray);
  99. if (retval != UA_STATUSCODE_GOOD) {
  100. UA_Array_delete(endpointArray, endpointArraySize,
  101. &UA_TYPES[UA_TYPES_ENDPOINTDESCRIPTION]);
  102. UA_LOG_ERROR(logger, UA_LOGCATEGORY_SERVER, "GetEndpoints failed with %s", UA_StatusCode_name(retval));
  103. UA_Client_delete(client);
  104. return NULL;
  105. }
  106. UA_LOG_DEBUG(logger, UA_LOGCATEGORY_SERVER, "Server has %ld endpoints", endpointArraySize);
  107. UA_EndpointDescription *foundEndpoint = NULL;
  108. for (size_t i = 0; i < endpointArraySize; i++) {
  109. UA_LOG_DEBUG(logger, UA_LOGCATEGORY_SERVER, "\tURL = %.*s, SecurityMode = %s",
  110. (int) endpointArray[i].endpointUrl.length,
  111. endpointArray[i].endpointUrl.data,
  112. endpointArray[i].securityMode == UA_MESSAGESECURITYMODE_NONE ? "None" :
  113. endpointArray[i].securityMode == UA_MESSAGESECURITYMODE_SIGN ? "Sign" :
  114. endpointArray[i].securityMode == UA_MESSAGESECURITYMODE_SIGNANDENCRYPT ? "SignAndEncrypt" :
  115. "Invalid"
  116. );
  117. // find the endpoint with highest supported security mode
  118. if ((UA_String_equal(&endpointArray[i].securityPolicyUri, &UA_SECURITY_POLICY_NONE_URI) ||
  119. UA_String_equal(&endpointArray[i].securityPolicyUri, &UA_SECURITY_POLICY_BASIC128_URI)) && (
  120. foundEndpoint == NULL || foundEndpoint->securityMode < endpointArray[i].securityMode))
  121. foundEndpoint = &endpointArray[i];
  122. }
  123. UA_EndpointDescription *returnEndpoint = NULL;
  124. if (foundEndpoint != NULL) {
  125. returnEndpoint = UA_EndpointDescription_new();
  126. UA_EndpointDescription_copy(foundEndpoint, returnEndpoint);
  127. }
  128. UA_Array_delete(endpointArray, endpointArraySize,
  129. &UA_TYPES[UA_TYPES_ENDPOINTDESCRIPTION]);
  130. return returnEndpoint;
  131. }
  132. #ifdef UA_ENABLE_ENCRYPTION
  133. /* loadFile parses the certificate file.
  134. *
  135. * @param path specifies the file name given in argv[]
  136. * @return Returns the file content after parsing */
  137. static UA_ByteString loadFile(const char *const path) {
  138. UA_ByteString fileContents = UA_BYTESTRING_NULL;
  139. if (path == NULL)
  140. return fileContents;
  141. /* Open the file */
  142. FILE *fp = fopen(path, "rb");
  143. if (!fp) {
  144. errno = 0; /* We read errno also from the tcp layer */
  145. return fileContents;
  146. }
  147. /* Get the file length, allocate the data and read */
  148. fseek(fp, 0, SEEK_END);
  149. fileContents.length = (size_t) ftell(fp);
  150. fileContents.data = (UA_Byte *) UA_malloc(fileContents.length * sizeof(UA_Byte));
  151. if (fileContents.data) {
  152. fseek(fp, 0, SEEK_SET);
  153. size_t read = fread(fileContents.data, sizeof(UA_Byte), fileContents.length, fp);
  154. if (read != fileContents.length)
  155. UA_ByteString_deleteMembers(&fileContents);
  156. } else {
  157. fileContents.length = 0;
  158. }
  159. fclose(fp);
  160. return fileContents;
  161. }
  162. #endif
  163. /**
  164. * Initialize a client instance which is used for calling the registerServer service.
  165. * If the given endpoint has securityMode NONE, a client with default configuration
  166. * is returned.
  167. * If it is using SignAndEncrypt, the client certificates must be provided as a
  168. * command line argument and then the client is initialized using these certificates.
  169. * @param endpointRegister The remote endpoint where this server should register
  170. * @param argc from the main method
  171. * @param argv from the main method
  172. * @return NULL or the initialized non-connected client
  173. */
  174. static
  175. UA_Client *getRegisterClient(UA_EndpointDescription *endpointRegister, int argc, char **argv) {
  176. if (endpointRegister->securityMode == UA_MESSAGESECURITYMODE_NONE) {
  177. UA_LOG_INFO(logger, UA_LOGCATEGORY_SERVER, "Using LDS endpoint with security None");
  178. return UA_Client_new(UA_ClientConfig_default);
  179. }
  180. #ifdef UA_ENABLE_ENCRYPTION
  181. if (endpointRegister->securityMode == UA_MESSAGESECURITYMODE_SIGN) {
  182. UA_LOG_INFO(logger, UA_LOGCATEGORY_SERVER, "LDS endpoint which only supports Sign is currently not supported");
  183. return NULL;
  184. }
  185. UA_Client *clientRegister;
  186. UA_LOG_INFO(logger, UA_LOGCATEGORY_SERVER, "Using LDS endpoint with security SignAndEncrypt");
  187. UA_ByteString certificate = UA_BYTESTRING_NULL;
  188. UA_ByteString privateKey = UA_BYTESTRING_NULL;
  189. UA_ByteString *trustList = NULL;
  190. size_t trustListSize = 0;
  191. UA_ByteString *revocationList = NULL;
  192. size_t revocationListSize = 0;
  193. if (argc < 3) {
  194. UA_LOG_FATAL(UA_Log_Stdout, UA_LOGCATEGORY_USERLAND,
  195. "The Certificate and key is missing."
  196. "The required arguments are "
  197. "<client-certificate.der> <client-private-key.der> "
  198. "[<trustlist1.crl>, ...]");
  199. return NULL;
  200. }
  201. certificate = loadFile(argv[1]);
  202. privateKey = loadFile(argv[2]);
  203. /* Load the trustList. Load revocationList is not supported now */
  204. if (argc > 3) {
  205. trustListSize = (size_t) argc - 3;
  206. UA_StatusCode retval = UA_ByteString_allocBuffer(trustList, trustListSize);
  207. if (retval != UA_STATUSCODE_GOOD) {
  208. UA_ByteString_deleteMembers(&certificate);
  209. UA_ByteString_deleteMembers(&privateKey);
  210. return NULL;
  211. }
  212. for (size_t trustListCount = 0; trustListCount < trustListSize; trustListCount++) {
  213. trustList[trustListCount] = loadFile(argv[trustListCount + 3]);
  214. }
  215. }
  216. /* Secure client initialization */
  217. clientRegister = UA_Client_secure_new(UA_ClientConfig_default,
  218. certificate, privateKey,
  219. &endpointRegister->serverCertificate,
  220. trustList, trustListSize,
  221. revocationList, revocationListSize,
  222. UA_SecurityPolicy_Basic128Rsa15);
  223. UA_ByteString_deleteMembers(&certificate);
  224. UA_ByteString_deleteMembers(&privateKey);
  225. for (size_t deleteCount = 0; deleteCount < trustListSize; deleteCount++) {
  226. UA_ByteString_deleteMembers(&trustList[deleteCount]);
  227. }
  228. return clientRegister;
  229. #else
  230. return NULL;
  231. #endif
  232. }
  233. int main(int argc, char **argv) {
  234. signal(SIGINT, stopHandler); /* catches ctrl-c */
  235. signal(SIGTERM, stopHandler);
  236. UA_ServerConfig *config = UA_ServerConfig_new_minimal(16600, NULL);
  237. // To enable mDNS discovery, set application type to discovery server.
  238. config->applicationDescription.applicationType = UA_APPLICATIONTYPE_DISCOVERYSERVER;
  239. UA_String_deleteMembers(&config->applicationDescription.applicationUri);
  240. config->applicationDescription.applicationUri =
  241. UA_String_fromChars("urn:open62541.example.server_multicast");
  242. config->mdnsServerName = UA_String_fromChars("Sample Multicast Server");
  243. // See http://www.opcfoundation.org/UA/schemas/1.03/ServerCapabilities.csv
  244. //config.serverCapabilitiesSize = 1;
  245. //UA_String caps = UA_String_fromChars("LDS");
  246. //config.serverCapabilities = &caps;
  247. UA_Server *server = UA_Server_new(config);
  248. self_discovery_url = &config->networkLayers[0].discoveryUrl;
  249. /* add a variable node to the address space */
  250. UA_Int32 myInteger = 42;
  251. UA_NodeId myIntegerNodeId = UA_NODEID_STRING(1, "the.answer");
  252. UA_QualifiedName myIntegerName = UA_QUALIFIEDNAME(1, "the answer");
  253. UA_DataSource dateDataSource;
  254. dateDataSource.read = readInteger;
  255. dateDataSource.write = writeInteger;
  256. UA_VariableAttributes attr = UA_VariableAttributes_default;
  257. attr.description = UA_LOCALIZEDTEXT("en-US", "the answer");
  258. attr.displayName = UA_LOCALIZEDTEXT("en-US", "the answer");
  259. UA_Server_addDataSourceVariableNode(server, myIntegerNodeId,
  260. UA_NODEID_NUMERIC(0, UA_NS0ID_OBJECTSFOLDER),
  261. UA_NODEID_NUMERIC(0, UA_NS0ID_ORGANIZES),
  262. myIntegerName, UA_NODEID_NULL, attr, dateDataSource,
  263. &myInteger, NULL);
  264. // callback which is called when a new server is detected through mDNS
  265. UA_Server_setServerOnNetworkCallback(server, serverOnNetworkCallback, NULL);
  266. // Start the server and call iterate to wait for the multicast discovery of the LDS
  267. UA_StatusCode retval = UA_Server_run_startup(server);
  268. if(retval != UA_STATUSCODE_GOOD) {
  269. UA_LOG_ERROR(logger, UA_LOGCATEGORY_SERVER,
  270. "Could not start the server. StatusCode %s",
  271. UA_StatusCode_name(retval));
  272. UA_Server_delete(server);
  273. UA_ServerConfig_delete(config);
  274. UA_free(discovery_url);
  275. return 1;
  276. }
  277. UA_LOG_INFO(logger, UA_LOGCATEGORY_SERVER,
  278. "Server started. Waiting for announce of LDS Server.");
  279. while (running && discovery_url == NULL)
  280. UA_Server_run_iterate(server, true);
  281. if(!running) {
  282. UA_Server_delete(server);
  283. UA_ServerConfig_delete(config);
  284. UA_free(discovery_url);
  285. return 1;
  286. }
  287. UA_LOG_INFO(logger, UA_LOGCATEGORY_SERVER, "LDS-ME server found on %s", discovery_url);
  288. /* Check if the server supports sign and encrypt. OPC Foundation LDS requires an encrypted session for
  289. * RegisterServer call, our server currently uses encrpytion optionally */
  290. UA_EndpointDescription *endpointRegister = getRegisterEndpointFromServer(discovery_url);
  291. UA_free(discovery_url);
  292. if (endpointRegister == NULL || endpointRegister->securityMode == UA_MESSAGESECURITYMODE_INVALID) {
  293. UA_LOG_ERROR(logger, UA_LOGCATEGORY_SERVER, "Could not find any suitable endpoints on discovery server");
  294. UA_Server_delete(server);
  295. UA_ServerConfig_delete(config);
  296. return 1;
  297. }
  298. UA_Client *clientRegister = getRegisterClient(endpointRegister, argc, argv);
  299. if (!clientRegister) {
  300. UA_LOG_FATAL(UA_Log_Stdout, UA_LOGCATEGORY_USERLAND,
  301. "Could not create the client for remote registering");
  302. UA_Server_delete(server);
  303. UA_ServerConfig_delete(config);
  304. return 1;
  305. }
  306. /* Connect the client */
  307. char *endpointUrl = (char*)UA_malloc(endpointRegister->endpointUrl.length + 1);
  308. memcpy(endpointUrl, endpointRegister->endpointUrl.data, endpointRegister->endpointUrl.length);
  309. endpointUrl[endpointRegister->endpointUrl.length] = 0;
  310. retval = UA_Server_addPeriodicServerRegisterCallback(server, clientRegister, endpointUrl,
  311. 10 * 60 * 1000, 500, NULL);
  312. if(retval != UA_STATUSCODE_GOOD) {
  313. UA_LOG_ERROR(logger, UA_LOGCATEGORY_SERVER,
  314. "Could not create periodic job for server register. StatusCode %s",
  315. UA_StatusCode_name(retval));
  316. UA_free(endpointUrl);
  317. UA_Client_disconnect(clientRegister);
  318. UA_Client_delete(clientRegister);
  319. UA_Server_delete(server);
  320. UA_ServerConfig_delete(config);
  321. return 1;
  322. }
  323. while (running)
  324. UA_Server_run_iterate(server, true);
  325. UA_Server_run_shutdown(server);
  326. // UNregister the server from the discovery server.
  327. retval = UA_Server_unregister_discovery(server, clientRegister);
  328. if (retval != UA_STATUSCODE_GOOD)
  329. UA_LOG_ERROR(logger, UA_LOGCATEGORY_SERVER,
  330. "Could not unregister server from discovery server. "
  331. "StatusCode %s", UA_StatusCode_name(retval));
  332. UA_free(endpointUrl);
  333. UA_Client_disconnect(clientRegister);
  334. UA_Client_delete(clientRegister);
  335. UA_Server_delete(server);
  336. UA_ServerConfig_delete(config);
  337. return (int)retval;
  338. }