InfoMagic Internet Tools 1993 July/Internet Tools.iso/RockRidge/security/xinetd/xinetd.2.0.6/intcommon.c

C/C++ Source or Header | 1993-01-22 | 5.0 KB | 235 lines

/*
 * (c) Copyright 1992 by Panagiotis Tsirigotis
 * All rights reserved.  The file named COPYRIGHT specifies the terms
 * and conditions for redistribution.
 */

static char RCSid[] = "$Id: intcommon.c,v 5.1 1992/11/01 00:01:21 panos Exp $" ;

#include <sys/types.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <signal.h>
#include <syslog.h>
#include <errno.h>

#include "int.h"
#include "defs.h"
#include "server.h"
#include "config.h"
#include "state.h"

void msg() ;


void int_fail( ip, syscall )
    struct intercept *ip ;
    char *syscall ;
{
    msg( LOG_ERR, "fail", "%s failed: %m", syscall ) ;
    (*ip->ops->exit)() ;
    /* NOTREACHED */
}


/*
 * Returns either a positive number or -1
 */
int int_select( max, read_mask )
    int max ;
    fd_set *read_mask ;
{
    char *func = "int_select" ;

    for ( ;; )
    {
        int n_ready ;

        n_ready = select( max+1, read_mask,
                                            FD_SET_NULL, FD_SET_NULL, TIMEVAL_NULL ) ;
        if ( n_ready > 0 )
            return( n_ready ) ;
        else if ( n_ready == -1 )
            if ( errno == EINTR )
                continue ;
            else
            {
                msg( LOG_ERR, func, "select: %m" ) ;
                return( -1 ) ;
            }
    }
}


void int_exit( ip )
    struct intercept *ip ;
{
    int status = INT_SERVER( ip )->exit_status ;
    char *func = "int_exit" ;

    if ( debug.on )
    {
        if ( PROC_EXITED( status ) )
            msg( LOG_DEBUG, func, "intercepted server died" ) ;
        else if ( PROC_SIGNALED( status ) )
            msg( LOG_DEBUG, func, "intercepted server received signal %d",
                    PROC_TERMSIG( status ) ) ;
    }
    _exit( (int) PROC_EXITSTATUS( status ) ) ;
}


/*
 * The ops vector must be installed before invoking this function
 */
void int_init( ip, serp )
    struct intercept *ip ;
    struct server *serp ;
{
    int flags ;
    register unsigned u ;
    char *func = "int_init" ;
    void int_sighandler() ;

   /*
    * Close all unneeded descriptors
    */
   for ( u = 0 ; u < pset_count( SERVICES( ps ) ) ; u++ )
   {
      struct service *sp = SP( pset_pointer( SERVICES( ps ), u ) ) ;

      if ( sp == SERVER_SERVICE( serp ) )
         continue ;
      if ( LOG( CONF( sp ) )->log_type == L_FILE )
         xlog_destroy( SDATA( sp )->log_handle ) ;
      (void) close( SVC_FD( sp ) ) ;
   }

    /*
     * Setup signal handling
     */
    if ( (int) signal( SERVER_EXIT_SIG, int_sighandler ) == -1 )
        int_fail( ip, "signal" ) ;
    if ( (int) signal( INTERCEPT_SIG, int_sighandler ) == -1 )
        int_fail( ip, "signal" ) ;
    if ( (int) signal( SIGTERM, int_sighandler ) == -1 )
        int_fail( ip, "signal" ) ;

    /*
     * Initialize state
     */
    INTERCEPT( ip ) = TRUE ;
    *INT_SERVER( ip ) = *serp ;
    INT_REMOTE( ip ) = SERVER_FD( serp ) ;

    flags = FSM_RETURN_ERROR ;
#ifdef DEBUG
    flags |= FSM_ZERO_FREE ;
#endif
    INT_ALLOCATOR( ip ) = fsm_create( sizeof( channel_s ), 0, flags ) ;
    if ( INT_ALLOCATOR( ip ) == NULL )
    {
        msg( LOG_ERR, func, ES_NOMEM ) ;
        (*ip->ops->exit)() ;
    }

    INT_CONNECTIONS( ip ) = pset_create( 0, 0 ) ;
    if ( INT_CONNECTIONS( ip ) == NULL )
    {
        msg( LOG_ERR, func, ES_NOMEM ) ;
        (*ip->ops->exit)() ;
    }
}



/*
 * Make a new connection to the local server
 */
channel_s *int_newconn( ip, sinp, remote_socket )
    struct intercept *ip ;
    struct sockaddr_in *sinp ;
    int remote_socket ;
{
    int socket_type = CONF( INT_SERVER( ip )->sp )->socket_type ;
    struct sockaddr_in *local = INT_LOCALADDR( ip ) ;
   channel_s *chp ;
   int sd ;
   char *func = "int_newconn" ;

   /*
    * Get a socket and connect it to the local address
    */
   if ( ( sd = socket( AF_INET, socket_type, 0 ) ) == -1 )
   {
      msg( LOG_ERR, func, "socket creation: %m" ) ;
      return( NULL ) ;
   }

   if ( connect( sd, SA( local ), sizeof( *local ) ) == -1 )
   {
      msg( LOG_ERR, func, "connect: %m" ) ;
      (void) close( sd ) ;
      return( NULL ) ;
   }

   chp = CHP( fsm_alloc( INT_ALLOCATOR( ip ) ) ) ;
   if ( chp == NULL )
   {
      msg( LOG_ERR, func, ES_NOMEM ) ;
      (void) close( sd ) ;
      return( NULL ) ;
   }

   if ( pset_add( INT_CONNECTIONS( ip ), chp ) == NULL )
   {
      msg( LOG_ERR, func, ES_NOMEM ) ;
      fsm_free( INT_ALLOCATOR( ip ), (char *) chp ) ;
      (void) close( sd ) ;
      return( NULL ) ;
   }

    chp->state = GOOD_CHANNEL ;
    chp->from = *sinp ;
   chp->local_socket = sd ;
    chp->remote_socket = remote_socket ;
   return( chp ) ;
}



/*
 * Check if the (address,port) in sinp is already in the connection table.
 * Return value:
 *    a connection pointer if the address is found
 *    NULL if the address if not found
 *
 * *addr_checked is set to TRUE of FALSE depending on whether there
 * is already a connection from the same IP address in the table.
 */
channel_s *int_lookupconn( ip, sinp, addr_checked )
    struct intercept *ip ;
   struct sockaddr_in *sinp ;
   bool_int *addr_checked ;
{
   register unsigned u ;
    register pset_h conntab = INT_CONNECTIONS( ip ) ;

   *addr_checked = FALSE ;

   for ( u = 0 ; u < pset_count( conntab ) ; u++ )
   {
      register channel_s *chp = CHP( pset_pointer( conntab, u ) ) ;

      if ( chp->from.sin_addr.s_addr == sinp->sin_addr.s_addr )
      {
         *addr_checked |= TRUE ;
         if ( chp->from.sin_port == sinp->sin_port )
            return( chp ) ;
      }
   }
   return( NULL ) ;
}