SK/processes/sockets/s-inet-tcp-urgent.c
Dawid Pietrykowski 305a058d0c Urgent sockets
2023-02-11 14:57:30 +01:00

112 lines
2.4 KiB
C

#include <sys/socket.h>
#include <netinet/in.h>
#include <string.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <signal.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
typedef struct sockaddr_in SockAddr_in;
typedef struct sockaddr SockAddr;
SockAddr_in addr;
SockAddr_in addr_client;
socklen_t addr_size;
int socket_fd;
int client_socket;
void handle_error(char *txt)
{
perror(txt);
exit(-1);
}
void receive_urgent(int signo)
{
double dd;
printf("OOB received\n");
if (recv(client_socket, &dd, sizeof(double), MSG_OOB) == -1)
handle_error("recv urgent");
printf("urgent dd: %f\n", dd);
signal(SIGURG, receive_urgent);
}
void end_connection()
{
if (close(socket_fd) == -1)
handle_error("close");
exit(0);
}
int main()
{
signal(SIGINT, end_connection);
signal(SIGTERM, end_connection);
if ((socket_fd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
handle_error("socket");
printf("socket success\n");
addr_size = sizeof(SockAddr_in);
memset(&addr, 0, addr_size);
addr.sin_port = htons(4040);
addr.sin_family = AF_INET;
addr.sin_addr.s_addr = htonl(INADDR_ANY);
if (bind(socket_fd, (SockAddr *)&addr, addr_size) == -1)
handle_error("bind");
printf("bind success\n");
if (listen(socket_fd, 10) == -1)
handle_error("listen");
printf("listen success\n");
double dd;
for (;;)
{
if ((client_socket = accept(socket_fd, (SockAddr *)&addr_client, &addr_size)) == -1)
handle_error("accept");
printf("accept success\n");
int i;
if ((i = fork()) == -1)
handle_error("fork");
printf("fork success\n");
if (i == 0)
{
close(socket_fd);
signal(SIGURG, receive_urgent);
fcntl(client_socket, F_SETOWN, getpid());
for (;;)
{
int bytes = read(client_socket, &dd, sizeof(double));
if (bytes == -1)
handle_error("recvfrom");
if (bytes == 0)
{
printf("EOF\n");
break;
}
else
{
printf("dd: %f\n", dd);
}
}
close(client_socket);
return 0;
}
else
{
sigignore(SIGCHLD);
close(client_socket);
}
}
return 0;
}