// internet_server.cpp
#include "includes.h"
#include "internet_server.h"

int internet_server::session_count=0;
extern int errno;

internet_server::internet_server(void)
{ session_count+=1;
  session_number=session_count;
  allOK=false;
  make_socket_connected_to_random_port();
  printf("[server established on port %d]\n",port_number);

  signal(SIGCHLD,(sig_t)internet_server::server_subprocess_reaper);
  signal(SIGINT,(sig_t)internet_server::received_halt_signal);
  allOK=true; }

void internet_server::server_subprocess_reaper(void)
{ int process_id,exit_status;
  process_id=wait(&exit_status); }

void internet_server::received_halt_signal(void)
{ int r;
  signal(SIGINT,SIG_DFL);
  printf("[Received halt signal, waiting for subprocesses]\n");
  do r=wait(NULL); while (r!=-1);
  printf("[Server terminated]\n");
  exit(2); }

int internet_server::getSessionNumber(void)
{ return session_number; }

char *internet_server::getClientName(void)
{ strcpy(templine,client_name);
  return templine; }

void internet_server::make_socket_connected_to_random_port(void)
{ int r;
  struct sockaddr_in my_connection_info;
  struct sockaddr *mci_ptr=(struct sockaddr *)&my_connection_info;
  const int mci_size=sizeof(my_connection_info);
  time_t now=time(NULL);
  srand(now^getpid());
  server_socket=socket(AF_INET,SOCK_STREAM,0);
  if (server_socket<0)
  { fprintf(stderr,"Can't create socket\n");
    perror("");
    exit(1); }
  do
  { port_number=1024+(rand() & 0x1FFF);
    bzero(mci_ptr,mci_size);
    my_connection_info.sin_family=AF_INET;
    my_connection_info.sin_addr.s_addr=htonl(INADDR_ANY);
    my_connection_info.sin_port=htons(port_number);
    r=bind(server_socket,mci_ptr,mci_size); } while (r<0);

  r=listen(server_socket,3);
  if (r<0)
  { fprintf(stderr,"Failure while listening");
    perror("");
    exit(1); } }

void internet_server::waitforuser(void)
{ while (1)
  { long int client_ip_addr;
    struct sockaddr_in client_info;
    struct sockaddr *ci_ptr=(struct sockaddr *)&client_info;
    int ci_size=sizeof(client_info);

    session_socket=accept(server_socket,ci_ptr,&ci_size);
    if (session_socket<0)
    { if (errno==EINTR) continue;
      perror("accept");
      sleep(1);
      continue; }
    session_number+=1;
    if (fork()==0)
    { struct in_addr client_addr;
      client_addr.s_addr=client_info.sin_addr.s_addr;
      strcpy(client_name,inet_ntoa(client_addr));
      printf("[connection accepted from %s: session %d]\n",
             client_name, session_number);

      read_file=fdopen(session_socket,"r");
      write_file=fdopen(session_socket,"w");
      if (read_file==NULL || write_file==NULL)
      { printf("[bad connection, session %d terminated]\n", session_number);
        exit(1); }
      return; }
    close(session_socket); } }

void internet_server::disconnect(void)
{ exit(0); }