Code:
void sigchld_handler(int s)
{
while(waitpid(-1, NULL, WNOHANG) > 0);
}
// get sockaddr, IPv4 or IPv6:
void *get_in_addr(struct sockaddr *sa)
{
if (sa->sa_family == AF_INET) {
return &(((struct sockaddr_in*)sa)->sin_addr);
}
return &(((struct sockaddr_in6*)sa)->sin6_addr);
}
int sockfd, new_fd; // listen on sock_fd, new connection on new_fd
int rc;
struct addrinfo hints, *servinfo, *p;
struct sockaddr_storage their_addr; // connector's address information
socklen_t sin_size;
struct sigaction sa;
int yes=1;
char s[INET6_ADDRSTRLEN];
int rv;
char recv_client_msg[100];
memset(&hints, 0, sizeof hints);
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
hints.ai_flags = AI_PASSIVE; // use my IP
if ((rv = getaddrinfo(NULL, PORT, &hints, &servinfo)) != 0) {
fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(rv));
return 1;
}
// loop throui_pgh all the results and bind to the first we can
for(p = servinfo; p != NULL; p = p->ai_next) {
if ((sockfd = socket(p->ai_family, p->ai_socktype,
p->arotocol)) == -1) {
perror("server: socket");
continue;
}
if (setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &yes,
sizeof(int)) == -1) {
perror("setsockopt");
exit(1);
}
if (bind(sockfd, p->ai_addr, p->ai_addrlen) == -1) {
close(sockfd);
perror("server: bind");
continue;
}
break;
}
if (p == NULL) {
fprintf(stderr, "server: failed to bind\n");
return 2;
}
freeaddrinfo(servinfo); // all done with this structure
if (listen(sockfd, BACKLOG) == -1) {
perror("listen");
exit(1);
}
sa.sa_handler = sigchld_handler; // reap all dead processes
sigemptyset(&sa.sa_mask);
sa.sa_flags = SA_RESTART;
if (sigaction(SIGCHLD, &sa, NULL) == -1) {
perror("sigaction");
exit(1);
}
int RemoteCommand(){ // main accept() loop
sin_size = sizeof their_addr;
new_fd = accept(sockfd, (struct sockaddr *)&their_addr, &sin_size);
if (new_fd == -1) {
perror("accept");
return(-1);
}
//fcntl(sockfd, F_SETFL, O_NONBLOCK);
//fcntl(new_fd, F_SETFL, O_NONBLOCK);
inet_ntop(their_addr.ss_family,
get_in_addr((struct sockaddr *)&their_addr),
s, sizeof s);
printf("server: got connection from %s\n", s);
if (!fork()) { // this is the child process
close(sockfd); // child doesn't need the listener
if (send(new_fd, "Hello, world!", 13, 0) == -1)
perror("send");
while(1)
{
rc = read(new_fd, recv_client_msg, sizeof(recv_client_msg));
if(write(new_fd,recv_client_msg, rc) <0 ) { printf("error writing to stream socket\n"); }
if(recv_client_msg[0]=='1') {commandSwitch(1,1);}
if(recv_client_msg[0]=='2') {commandSwitch(1,2);}
if(recv_client_msg[0]=='3') {commandSwitch(2,1);}
if(recv_client_msg[0]=='4') {commandSwitch(2,2);}
}
close(new_fd);
exit(0);
}
close(new_fd); // parent doesn't need this
return(0);
}
//end of socket setup