RTM Project

app/client.c

@@ -0,0 +1,156 @@
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/shm.h>
+#include <sys/mman.h>
+#include <fcntl.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <signal.h>
+
+#include "dll.h"
+#include "mac-list.h"
+#include "routing-table.h"
+#include "sync.h"
+
+int data_socket;
+int loop = 1; // indicates if server is still up and running
+int disconnect = 1; // indicates to server that client wants to disconnect
+
+/*
+* Client's copies of network data structures.
+*/
+dll_t* routing_table;
+dll_t* mac_list;
+
+/* Break out of main infinite loop and inform server of intent to disconnect */
+
+void signal_handler(int signal_num) {
+	
+	if (signal_num == SIGINT) {
+		loop = 0;
+		write(data_socket, &disconnect, sizeof(int));
+		close(data_socket);
+		deinit_dll(routing_table);
+		deinit_dll(mac_list);
+		exit(0);
+	}
+	else if (signal_num == SIGUSR1) {
+		deinit_dll(routing_table);
+		deinit_dll(mac_list);
+
+		routing_table = init_dll();
+		mac_list = init_dll();
+	}
+
+}
+
+/*
+* Optionally, display contents of a data
+* structure (routing table or MAC list).
+*/
+void display_ds(int synchronized) {
+	char c, flush;
+
+	switch (synchronized) {
+	case RT:
+
+		printf("Routing table is up to date. Would you like to see it?(y/n)\n");
+		c = getchar();
+
+		scanf("%c", &flush);
+		if (c == 'y') {
+			display_routing_table(routing_table);
+		}
+
+		break;
+
+	case ML:
+
+		printf("MAC list is up to date. Would you like to see it?(y/n)\n");
+		c = getchar();
+		scanf("%c", &flush);
+		if (c == 'y') {
+			display_mac_list(mac_list);
+		}
+		break;
+
+	default:
+
+		break;
+	}
+}
+
+int main() {
+
+	struct sockaddr_un addr;
+
+	routing_table = init_dll();
+	mac_list = init_dll();
+
+	data_socket = socket(AF_UNIX, SOCK_STREAM, 0);
+	if (data_socket == -1) {
+		perror("socket");
+		exit(1);
+	}
+
+	memset(&addr, 0, sizeof(struct sockaddr_un));
+	addr.sun_family = AF_UNIX;
+	strncpy(addr.sun_path, SOCKET_NAME, sizeof(addr.sun_path) - 1);
+
+	if (connect(data_socket, (const struct sockaddr*)&addr,
+		sizeof(struct sockaddr_un)) == -1) {
+		fprintf(stderr, "The server is down.\n");
+		exit(1);
+	}
+
+
+	pid_t pid = getpid();
+
+	write(data_socket, &pid, sizeof(pid_t)); // send server client's process id
+
+	signal(SIGINT, signal_handler); // register signal handler.
+	signal(SIGUSR1, signal_handler);
+	/*
+	* Continously wait for updates to routing table and MAC list
+	* from the server regarding table contents and server state.
+	*/
+
+	while (loop) {
+		int synchronized;
+		char ip[IP_ADDR_LEN];
+
+		sync_msg_t* sync_msg = calloc(1, sizeof(sync_msg_t));
+
+		memset(ip, 0, IP_ADDR_LEN);
+
+		if (read(data_socket, sync_msg, sizeof(sync_msg_t)) == -1) {
+			perror("read");
+			break;
+		}
+
+		if (read(data_socket, &synchronized, sizeof(int)) == -1) {
+			perror("read");
+			break;
+		}
+
+		if (read(data_socket, &loop, sizeof(int)) == -1) {
+			perror("read");
+			break;
+		}
+
+		if (sync_msg->l_code == L3) {
+			process_sync_mesg(routing_table, sync_msg);
+		}
+		else {
+			process_sync_mesg(mac_list, sync_msg);
+		}
+
+		display_ds(synchronized);
+	}
+
+	exit(0);
+}