/*****************************************************************
*  sthp_serv.c  the execute module is  is implementation 
*              the server side of String Type Handle Protocol
*  
* Copyright (C) 2009 Andrey Y. Rjavskov(aka rjaan) <rjaan@yandex.ru> 
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
*****************************************************************/
#include <stdio.h>
#include <stdlib.h> 
#include <string.h> 
#include <errno.h>
#include <signal.h>
#include <unistd.h>

#include <sys/un.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/wait.h>

#include "sthp.h"

static int _sockfd;

static void nothing_exec_sighandler ( int signum );
static void child_handler ( int sockfd );

static void sig_handler ( int sig_num );

int main ( char** argv, int argc ) __attribute__ ((__noreturn__));
int main ( char** argv, int argc ) 
{
   int status;
   int sockfd, optval = 1;
   struct sigaction sa, osa;   
   struct sockaddr_un   servaddr;

   print_stderr ( STDERRMSG_HAVE_BYTE_DEFAULT, "sthp server init \n");

   sa.sa_handler = nothing_exec_sighandler;
   sigemptyset ( &sa.sa_mask );
   sa.sa_flags = SA_RESTART;
   if ( sigaction ( SIGALRM, &sa, &osa ) < 0 ) {
     print_stderr ( STDERRMSG_HAVE_BYTE_DEFAULT, 
          "sthp server error: can\'t change the action taken by %d process.Terminated!\n", 
                                  getpid());
     exit ( EXIT_FAILURE ); 	
   } 

   sockfd = socket( AF_LOCAL, SOCK_STREAM, 0 );
   if( sockfd == -1 ) {
      print_stderr ( STDERRMSG_HAVE_BYTE_DEFAULT,
		"sthp server error: can\'t create socket!\n" );
      exit ( EXIT_FAILURE );
   } 
   sthp_set_signal ( &sockfd );
   _sockfd = sockfd;

   if ( setsockopt ( sockfd, SOL_SOCKET, SO_REUSEADDR, &optval, sizeof(int) ) ) {
      print_stderr ( STDERRMSG_HAVE_BYTE_DEFAULT, 
			"sthp server error: can\'t set option to socket!\n" );
      close( sockfd ); 
      exit ( EXIT_FAILURE );
   }  
   unlink( STHP_UNIXSERVER_PATH );
   bzero( &servaddr, sizeof ( struct sockaddr_un ) );
   servaddr.sun_family = AF_LOCAL;
   strcpy ( servaddr.sun_path, STHP_UNIXSERVER_PATH );
   if ( bind ( sockfd, 
          (struct sockaddr*)&servaddr, sizeof ( struct sockaddr_un ) ) == -1 ) {
      print_stderr ( STDERRMSG_HAVE_BYTE_DEFAULT, 
			"sthp server error: can\'t bind socket with unix path!\n" );
      close( sockfd ); 
      exit ( EXIT_FAILURE);
   }
   if ( listen ( sockfd, 1 ) == -1 ) {
       print_stderr ( STDERRMSG_HAVE_BYTE_DEFAULT, 
			"sthp server error: cannot transform an active socket into a passive socket!\n" );
       close( sockfd ); 
       exit ( EXIT_FAILURE );
   }     
 
   print_stderr ( STDERRMSG_HAVE_BYTE_DEFAULT, "sthp server wait connections!\n");
   signal ( SIGCLD, SIG_IGN );
   waitpid ( -1, &status, WNOHANG );
   while ( 1 ) {
      int                  newsockfd; 
      struct sockaddr_un   cliaddr; 
      int                  cliaddr_len = sizeof ( struct sockaddr_un );

      if ( ( newsockfd = 
                accept ( sockfd, (struct sockaddr*)&cliaddr, &cliaddr_len ) ) == -1 ) {
             print_stderr ( STDERRMSG_HAVE_BYTE_DEFAULT, 
			"sthp server error: cannot transform an active socket into a passive socket!\n" );
             close( sockfd ); 
             exit ( EXIT_FAILURE );
      }

      if ( !fork( ) ) {
        close(sockfd);
        child_handler ( newsockfd );
        exit(0);
      }

      close(newsockfd);
   } 

   close ( sockfd ); 
   exit  ( EXIT_SUCCESS );

}

static void
nothing_exec_sighandler ( int signum )
{
  if ( signum != SIGALRM ) {
     return;
  }
  print_stderr ( STDERRMSG_HAVE_BYTE_DEFAULT, 
       "%d process has accepted SIGALARM at time system call executing", getpid() ); 
}

static void 
child_handler ( int sockfd )
{
  int   bytes = 0;
  char  *ask = NULL;
  char  *reply;

  if ( ( bytes = sthp_recv ( sockfd, &ask ) ) == -EXIT_FAILURE ) {
      goto child_end;
  }
  print_stderr ( strlen(ask), "ACCEPTED STRING: \"%s\"\n", ask);
  reply = STRING_TYPE_NAME ( sthp_is_string_type_from ( ask ) );
  print_stderr ( strlen(ask), "IT HAVE LENGTH: %d BYTES\n", bytes );
  print_stderr ( strlen(ask), "IT HAVE TYPE: %s\n", reply );
  if( sthp_send ( sockfd, reply ) == -EXIT_FAILURE  ) {
      goto child_end;
  }
  print_stderr ( strlen(ask), "SEND REPLY\n" );
  
child_end:

  if( ask ) { free( ask ); }     
  close(sockfd);

} 

/*eof*/