114 lines
3.3 KiB
C
114 lines
3.3 KiB
C
#include <arpa/inet.h> // For inet_addr(), htons()
|
|
#include <stdio.h> // For printf()
|
|
#include <stdlib.h> // For exit()
|
|
#include <string.h> // For memset()
|
|
#include <sys/socket.h> // For socket(), connect(), read(), write()
|
|
#include <time.h>
|
|
#include <unistd.h> // For close()
|
|
#include "sockets.h"
|
|
|
|
#define BUFFER_SIZE 1024
|
|
|
|
static void error_handling(char *message, int sock) {
|
|
perror(message);
|
|
close(sock);
|
|
exit(1);
|
|
}
|
|
|
|
int tcp_create_socket() {
|
|
// PF_INET: IPv4, SOCK_STREAM: TCP
|
|
int sock = socket(PF_INET, SOCK_STREAM, 0);
|
|
if (sock == -1)
|
|
error_handling("socket() error", sock);
|
|
return sock;
|
|
}
|
|
|
|
void connect_to_server(int sock, char *ip, int port) {
|
|
struct sockaddr_in serv_addr;
|
|
// Initialize serv_addr to zero
|
|
memset(&serv_addr, 0, sizeof(serv_addr));
|
|
// Set the address family to IPv4
|
|
serv_addr.sin_family = AF_INET;
|
|
// Convert IP address to binary form
|
|
serv_addr.sin_addr.s_addr = inet_addr(ip);
|
|
// Convert port number to network byte order
|
|
serv_addr.sin_port = htons(port);
|
|
|
|
if (connect(sock, (struct sockaddr*)&serv_addr, sizeof(serv_addr)) == -1)
|
|
error_handling("connect() error", sock);
|
|
}
|
|
|
|
char* communicate(int sock, char *message) {
|
|
// Sending the ASCII string
|
|
if (write(sock, message, strlen(message)) == -1)
|
|
error_handling("write() error", sock);
|
|
|
|
// Receiving response
|
|
char* response = malloc(BUFFER_SIZE);
|
|
if (!response)
|
|
error_handling("Failed to allocate memory for response", sock);
|
|
|
|
int str_len = read(sock, response, BUFFER_SIZE - 1);
|
|
if (str_len == -1){
|
|
free(response);
|
|
error_handling("read() error", sock);
|
|
} else if (str_len == 0) {
|
|
printf("Server closed the connection.\n");
|
|
free(response);
|
|
return NULL;
|
|
} else {
|
|
response[str_len] = '\0'; // Null-terminate the received data
|
|
}
|
|
return response;
|
|
}
|
|
|
|
int tcp_listen(int port) {
|
|
int sock = tcp_create_socket();
|
|
|
|
struct sockaddr_in serv_addr;
|
|
memset(&serv_addr, 0, sizeof(serv_addr));
|
|
serv_addr.sin_family = AF_INET;
|
|
serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
|
|
serv_addr.sin_port = htons(port);
|
|
|
|
if (bind(sock, (struct sockaddr*)&serv_addr, sizeof(serv_addr)) == -1)
|
|
error_handling("bind() error", sock);
|
|
|
|
if (listen(sock, 5) == -1)
|
|
error_handling("listen() error", sock);
|
|
|
|
return sock;
|
|
}
|
|
|
|
int tcp_accept(int serv_sock) {
|
|
struct sockaddr_in clnt_addr;
|
|
socklen_t clnt_addr_size = sizeof(clnt_addr);
|
|
int clnt_sock = accept(serv_sock, (struct sockaddr*)&clnt_addr, &clnt_addr_size);
|
|
if (clnt_sock == -1)
|
|
error_handling("accept() error", clnt_sock);
|
|
return clnt_sock;
|
|
}
|
|
|
|
void process_request(int clnt_sock) {
|
|
char message[BUFFER_SIZE];
|
|
int str_len = read(clnt_sock, message, BUFFER_SIZE - 1);
|
|
if (str_len == -1)
|
|
// TODO: clnt_sock might be a bug
|
|
error_handling("read() error", clnt_sock);
|
|
|
|
message[str_len] = '\0'; // Null-terminate the string
|
|
|
|
time_t t = time(NULL);
|
|
struct tm *timeinfo;
|
|
|
|
if (strcmp(message, "1") == 0) {
|
|
timeinfo = localtime(&t); // Local time
|
|
} else {
|
|
timeinfo = gmtime(&t); // GMT time
|
|
}
|
|
|
|
strftime(message, BUFFER_SIZE, "%Y-%m-%d %H:%M:%S", timeinfo);
|
|
write(clnt_sock, message, strlen(message));
|
|
}
|
|
|