Glasswalker

#include <stdio.h>#include <stdlib.h>#include <unistd.h>#include <errno.h>#include <string.h>#include <sys/types.h>#include <sys/socket.h>#include <netinet/in.h>#include <arpa/inet.h>#include <sys/wait.h>#include <signal.h>#define MYPORT 12040#define BACKLOG 10using namespace std;int tcpip_bindsocket(char s_address[16], int s_port);void tcpip_listen(int socketfd, int backlog);int tcpip_accept(int socketfd);void tcpip_close(int socketfd);void server_mainlistener(int socketfd);void server_mainclienthandler(int socketfd);void server_reaper();void server_reaper_handler(int s);int tcpip_bindsocket(char s_address[16], int s_port){    int sockfd;    int yes=1;    struct sockaddr_in my_addr;    if ((sockfd = socket(PF_INET, SOCK_STREAM, 0)) == -1)    {        perror("TCPIP Error: Failed to create socket");        exit(1);    }    if (setsockopt(sockfd,SOL_SOCKET,SO_REUSEADDR,&yes,sizeof(int)) == -1)    {        perror("TCPIP Error: setsockopt failed");        exit(1);    }    my_addr.sin_family = AF_INET;    my_addr.sin_addr.s_addr = inet_addr(s_address);    my_addr.sin_port = htons(s_port);    memset(&(my_addr.sin_zero), '\0', 8);    bind(sockfd, (struct sockaddr *)&my_addr, sizeof(struct sockaddr));    if (bind(sockfd, (struct sockaddr *)&my_addr, sizeof(struct sockaddr)) == -1)    {        perror("TCPIP Error: Can't bind to port");        exit(1);    }    return sockfd;}void tcpip_listen(int socketfd, int backlog){    if (listen(socketfd, backlog) == -1)    {        perror("TCPIP Error: Listen Failed");        exit(1);    }}int tcpip_accept(int socketfd){    socklen_t sin_size;    int new_fd;    struct sockaddr_in their_addr; // connector's address information    if ((new_fd = accept(socketfd, (struct sockaddr *)&their_addr, &sin_size)) == -1)    {        perror("TCPIP Error: Accept Failed");        exit(0);    }    return new_fd;}void tcpip_close(int socketfd){    close(socketfd);}void server_mainclienthandler(int socketfd){    send(socketfd, "Hello, world!\n", 14, 0);}void server_mainlistener(int socketfd){    socklen_t sin_size;    int client_sockfd;    struct sockaddr_in their_addr; // connector's address information    while(1)    {        sin_size = sizeof(struct sockaddr_in);        printf("TCPIP: got connection from %s\n",inet_ntoa(their_addr.sin_addr));        if (!fork())        {       // this is the child client handler process            client_sockfd = tcpip_accept(socketfd);            tcpip_close(socketfd); // child doesn't need the listener            server_mainclienthandler(client_sockfd);            tcpip_close(client_sockfd);            exit(0); //kill the child        }        tcpip_close(client_sockfd);  // parent doesn't need this    }}void server_reaper_handler(int s){    while(waitpid(-1, NULL, WNOHANG) > 0);}void server_reaper(){    struct sigaction sa;    sa.sa_handler = server_reaper_handler;    sigemptyset(&sa.sa_mask);    sa.sa_flags = SA_RESTART;    if (sigaction(SIGCHLD, &sa, NULL) == -1) {        perror("ERROR: Server Child Cleanup Failed");        exit(1);    }}main(){    int sockfd, new_fd;  // listen on sock_fd, new connection on new_fd    sockfd = tcpip_bindsocket("192.168.0.8",MYPORT); // open the socket    tcpip_listen(sockfd,BACKLOG); // start listening    server_reaper(); // reap dead child threads    server_mainlistener(sockfd); // run the main listener loop    exit(1);}