WebSVN – oidinfo_api – Blame – /trunk/csv_lookup_server_example/oid_lookup_srv.cpp

Rev	Author	Line No.	Line
3	daniel-mar	1	// **************************************************
14	daniel-mar	2	// OID CSV Lookup Server 1.2
		3	// (c) 2016-2020 ViaThinkSoft, Daniel Marschall
3	daniel-mar	4	// **************************************************
		5
		6	// todo: log verbosity + datetime
		7	// todo: publish at codelib
		8	// todo: server hat sich einfach so beendet... "read: connection reset by peer"
		9	// todo: 2019-02-24 service was booted together with the system, and i got "0 OIDs loaded". why???
		10	// todo: create vnag monitor that checks if this service is OK
14	daniel-mar	11	// todo: unexplained crash with version 1.1 : Signal "pipefail" (141) received after someone connected?!
3	daniel-mar	12
		13	#include "oid_lookup_srv.h"
		14
		15	unordered_set<string> lines;
		16
		17	int loadfile(const string &filename) {
		18	int cnt = 0;
		19
		20	ifstream infile(filename);
		21	string line;
		22	while (getline(infile, line)) {
		23	lines.insert(line);
		24	++cnt;
		25	}
		26	infile.close();
		27
		28	fprintf(stdout, "Loaded %d OIDs from %s\n", cnt, filename.c_str());
		29
		30	return cnt;
		31	}
		32
		33	bool stringAvailable(const string &str) {
		34	return lines.find(str) != lines.end();
		35	}
		36
		37	// Template of this code: http://www.gnu.org/software/libc/manual/html_node/Server-Example.html
		38	// http://www.gnu.org/software/libc/manual/html_node/Inet-Example.html#Inet-Example
		39
		40	struct con_descriptor {
		41	time_t last_activity;
		42	struct sockaddr_in clientname;
		43	int queries;
		44	time_t connect_ts;
		45	};
		46
		47	con_descriptor cons[FD_SETSIZE];
		48
		49	int read_from_client(int filedes) {
		50	char buffer[MAXMSG];
		51	int nbytes;
		52
14	daniel-mar	53	nbytes = read(filedes, buffer, sizeof(buffer));
		54	buffer[sizeof(buffer)-1] = 0; // Terminator
		55
3	daniel-mar	56	if (nbytes < 0) {
		57	/* Read error. */
		58	//perror("read");
		59	//exit(EXIT_FAILURE);
		60	return -1;
		61	} else if (nbytes == 0) {
		62	/* End-of-file. */
		63	return -1;
		64	} else {
		65	/* Data read. */
		66
14	daniel-mar	67	for (uint i=0; i<sizeof(buffer); ++i) {
		68	if ((buffer[i] == 13) \|\| (buffer[i] == 10)) {
		69	buffer[i] = 0; // Terminator
		70	break;
		71	}
3	daniel-mar	72	}
		73
		74	if (strcmp(buffer, "bye") == 0) {
		75	fprintf(stdout, "%s:%d[%d] Client said good bye.\n", inet_ntoa(cons[filedes].clientname.sin_addr), ntohs(cons[filedes].clientname.sin_port), filedes);
		76	return -1;
		77	} else {
		78	cons[filedes].queries++;
		79
14	daniel-mar	80	for (uint i=0; i<sizeof(buffer); ++i) {
		81	if (buffer[i] == 0) break;
		82	if (!((buffer[i] >= '0') && (buffer[i] <= '9')) && !(buffer[i] == '.')) {
		83	fprintf(stdout, "%s:%d[%d] Client sent an invalid request.\n", inet_ntoa(cons[filedes].clientname.sin_addr), ntohs(cons[filedes].clientname.sin_port), filedes);
		84	return -1;
		85	}
		86	}
		87
3	daniel-mar	88	// fprintf(stdout, "%s:%d[%d] Query #%d: %s\n", inet_ntoa(cons[filedes].clientname.sin_addr), ntohs(cons[filedes].clientname.sin_port), filedes, cons[filedes].queries, buffer);
		89
		90	if (stringAvailable(buffer)) {
		91	write(filedes, "1\n", 2);
		92	} else {
		93	write(filedes, "0\n", 2);
		94	}
		95	return 0;
		96	}
		97	}
		98	}
		99
		100	int fd_set_isset_count(const fd_set &my_fd_set) {
		101	int cnt = 0;
		102	for (int fd = 0; fd < FD_SETSIZE; ++fd) {
		103	if (FD_ISSET(fd, &my_fd_set)) {
		104	++cnt;
		105	}
		106	}
		107	return cnt;
		108	}
		109
		110	int loadCSVs() {
		111	return loadfile("oid_table.csv");
		112	}
		113
		114	void initConsArray() {
		115	for (int i=0; i<FD_SETSIZE; ++i) {
		116	cons[i].last_activity = 0;
		117	memset(&cons[i].clientname, 0, sizeof(sockaddr_in));
		118	cons[i].queries = 0;
		119	}
		120	}
		121
		122	int make_socket(uint16_t port) {
		123	int sock;
		124	struct sockaddr_in name;
		125
		126	/* Create the socket. */
		127	sock = socket(PF_INET, SOCK_STREAM, 0);
		128	if (sock < 0) {
		129	perror("socket");
		130	exit(EXIT_FAILURE);
		131	}
		132
		133	int enable = 1;
		134	if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &enable, sizeof(int)) < 0) {
		135	fprintf(stderr, "ERROR: setsockopt(SO_REUSEADDR) failed");
		136	exit(EXIT_FAILURE);
		137	}
		138
		139	/* Give the socket a name. */
		140	name.sin_family = AF_INET;
		141	name.sin_port = htons (port);
		142	name.sin_addr.s_addr = htonl (INADDR_ANY);
		143	if (bind (sock, (struct sockaddr *) &name, sizeof(name)) < 0) {
		144	perror("bind");
		145	exit(EXIT_FAILURE);
		146	}
		147
		148	return sock;
		149	}
		150
		151	int main(void) {
		152	// extern int make_socket(uint16_t port);
		153	int sock;
		154	fd_set active_fd_set, read_fd_set;
		155
14	daniel-mar	156	fprintf(stdout, "OID CSV Lookup Server 1.2 (c)2016-2020 ViaThinkSoft\n");
3	daniel-mar	157	fprintf(stdout, "Listening at port: %d\n", PORT);
		158	fprintf(stdout, "Max connections: %d\n", FD_SETSIZE);
		159
		160	initConsArray();
		161
		162	int loadedOIDs = loadCSVs();
		163	time_t csvLoad = time(NULL);
		164
		165	/* Create the socket and set it up to accept connections. */
		166	sock = make_socket(PORT);
		167	if (listen(sock, 1) < 0) {
		168	perror("listen");
		169	exit(EXIT_FAILURE);
		170	}
		171
		172	/* Initialize the set of active sockets. */
		173	FD_ZERO(&active_fd_set);
		174	FD_SET(sock, &active_fd_set);
		175
		176	while (1) {
		177	/* Block until input arrives on one or more active sockets. */
		178	read_fd_set = active_fd_set;
		179
		180	struct timeval tv;
		181	tv.tv_sec = 1;
		182	tv.tv_usec = 0; // Not init'ing this can cause strange errors
		183
		184	int retval = select(FD_SETSIZE, &read_fd_set, NULL, NULL, &tv);
		185
		186	if (retval < 0) {
		187	perror("select");
		188	exit(EXIT_FAILURE);
		189	} else if (retval == 0) {
		190	// fprintf(stdout, "Nothing received\n");
		191	} else {
		192	/* Service all the sockets with input pending. */
		193	for (int i=0; i < FD_SETSIZE; ++i) {
		194	if (FD_ISSET (i, &read_fd_set)) {
		195	if (i == sock) {
		196	/* Connection request on original socket. */
		197	int new_fd;
		198	struct sockaddr_in clientname;
		199	socklen_t size = sizeof(clientname);
		200	new_fd = accept(sock, (struct sockaddr *) &clientname, &size);
		201	if (new_fd < 0) {
		202	perror("accept");
		203	exit(EXIT_FAILURE);
		204	}
		205	FD_SET(new_fd, &active_fd_set);
		206
		207	cons[new_fd].clientname = clientname;
		208	cons[new_fd].connect_ts = time(NULL);
		209
		210	if (loadedOIDs == 0) {
		211	loadedOIDs = loadCSVs();
		212	if (loadedOIDs == 0) {
		213	fprintf(stderr, "%s:%d[%d] Service temporarily unavailable (OID list empty)\n", inet_ntoa(clientname.sin_addr), ntohs(clientname.sin_port), new_fd);
		214	close(new_fd);
		215	FD_CLR(new_fd, &active_fd_set);
		216	}
		217	}
		218
		219	if (fd_set_isset_count(active_fd_set)-1 > MAX_CONNECTIONS) { // -1 is because we need to exclude the listening socket (i=sock) which is not a connected client
		220	fprintf(stderr, "%s:%d[%d] Rejected because too many connections are open\n", inet_ntoa(clientname.sin_addr), ntohs(clientname.sin_port), new_fd);
		221	close(new_fd);
		222	FD_CLR(new_fd, &active_fd_set);
		223	} else {
		224	fprintf(stdout, "%s:%d[%d] Connected\n", inet_ntoa(clientname.sin_addr), ntohs(clientname.sin_port), new_fd);
		225	}
		226
14	daniel-mar	227	if (new_fd >= FD_SETSIZE) {
		228	fprintf(stderr, "%s:%d[%d] new_fd reached cons[FD_SETSIZE] limit\n", inet_ntoa(clientname.sin_addr), ntohs(clientname.sin_port), new_fd);
		229	close(new_fd);
		230	FD_CLR(new_fd, &active_fd_set);
		231	}
		232
3	daniel-mar	233	cons[new_fd].last_activity = time(NULL);
		234	cons[new_fd].queries = 0;
		235	} else {
		236	/* Data arriving on an already-connected socket. */
		237	cons[i].last_activity = time(NULL);
		238	if (read_from_client(i) < 0) {
		239	fprintf(stdout, "%s:%d[%d] Connection closed after %d queries in %lu seconds.\n", inet_ntoa(cons[i].clientname.sin_addr), ntohs(cons[i].clientname.sin_port), i, cons[i].queries, time(NULL)-cons[i].connect_ts);
		240	close(i);
		241	FD_CLR(i, &active_fd_set);
		242	}
		243	}
		244	}
		245	}
		246	}
		247
		248	/* Check if we need to reload the CSV */
		249	if (time(NULL)-csvLoad >= CSVRELOADINTERVAL) {
		250	loadCSVs();
		251	csvLoad = time(NULL);
		252	}
		253
		254	/* Check if we can close connections due to timeout */
		255	for (int i=0; i < FD_SETSIZE; ++i) {
		256	if (FD_ISSET(i, &active_fd_set)) {
		257	if (i == sock) continue;
		258	if (time(NULL)-cons[i].last_activity >= CONNECTION_TIMEOUT) {
		259	fprintf(stdout, "%s:%d[%d] Connection timeout.\n", inet_ntoa(cons[i].clientname.sin_addr), ntohs(cons[i].clientname.sin_port), i);
		260	fprintf(stdout, "%s:%d[%d] Connection closed after %d queries in %lu seconds.\n", inet_ntoa(cons[i].clientname.sin_addr), ntohs(cons[i].clientname.sin_port), i, cons[i].queries, time(NULL)-cons[i].connect_ts);
		261	close(i);
		262	FD_CLR(i, &active_fd_set);
		263	}
		264	}
		265	}
		266	}
		267	}

Subversion Repositories oidinfo_api

oidinfo_api/trunk/csv_lookup_server_example/oid_lookup_srv.cpp – Rev 14