Logo Search packages:      
Sourcecode: samba-doc-ja version File versions

server.c

/* 
   Unix SMB/Netbios implementation.
   Version 1.9.
   Main SMB server routines
   Copyright (C) Andrew Tridgell 1992-1998
   
   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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "includes.h"

pstring servicesf = CONFIGFILE;
extern fstring global_myworkgroup;
extern pstring global_myname;

int am_parent = 1;

/* the last message the was processed */
int last_message = -1;

/* a useful macro to debug the last message processed */
#define LAST_MESSAGE() smb_fn_name(last_message)

extern pstring user_socket_options;

#ifdef WITH_DFS
extern int dcelogin_atmost_once;
#endif /* WITH_DFS */

extern fstring remote_machine;

/* really we should have a top level context structure that has the
   client file descriptor as an element. That would require a major rewrite :(

   the following 2 functions are an alternative - they make the file
   descriptor private to smbd
 */
static int server_fd = -1;

int smbd_server_fd(void)
{
      return server_fd;
}

void smbd_set_server_fd(int fd)
{
      server_fd = fd;
      client_setfd(fd);
}

/****************************************************************************
 Terminate signal.
****************************************************************************/

SIG_ATOMIC_T got_sig_term;

static void sig_term(void)
{
      got_sig_term = 1;
      sys_select_signal();
}

/****************************************************************************
 Catch a sighup.
****************************************************************************/

SIG_ATOMIC_T reload_after_sighup;

static void sig_hup(int sig)
{
      reload_after_sighup = 1;
      sys_select_signal();
}

/****************************************************************************
  Send a SIGTERM to our process group.
*****************************************************************************/

static void  killkids(void)
{
      if(am_parent)
            kill(0,SIGTERM);
}

/****************************************************************************
 Open the socket communication - inetd.
****************************************************************************/

static BOOL open_sockets_inetd(void)
{
      /* Started from inetd. fd 0 is the socket. */
      /* We will abort gracefully when the client or remote system 
         goes away */
      smbd_set_server_fd(dup(0));
      
      /* close our standard file descriptors */
      close_low_fds();
      
      set_socket_options(smbd_server_fd(),"SO_KEEPALIVE");
      set_socket_options(smbd_server_fd(),user_socket_options);

      return True;
}

/****************************************************************************
 Have we reached the process limit ?
****************************************************************************/

BOOL allowable_number_of_smbd_processes(void)
{
      int max_processes = lp_max_smbd_processes();

      if (!max_processes)
            return True;

      {
            TDB_CONTEXT *tdb = conn_tdb_ctx();
            int32 val;
            if (!tdb) {
                  DEBUG(0,("allowable_number_of_smbd_processes: can't open connection tdb.\n" ));
                  return False;
            }

            val = tdb_fetch_int32(tdb, "INFO/total_smbds");
            if (val == -1 && (tdb_error(tdb) != TDB_ERR_NOEXIST)) {
                  DEBUG(0,("allowable_number_of_smbd_processes: can't fetch INFO/total_smbds. Error %s\n",
                        tdb_errorstr(tdb) ));
                  return False;
            }
            if (val > max_processes) {
                  DEBUG(0,("allowable_number_of_smbd_processes: number of processes (%d) is over allowed limit (%d)\n",
                        val, max_processes ));
                  return False;
            }
      }
      return True;
}

/****************************************************************************
 Open the socket communication.
****************************************************************************/

static BOOL open_sockets(BOOL is_daemon,BOOL interactive, int port)
{
      int num_interfaces = iface_count();
      int fd_listenset[FD_SETSIZE];
      fd_set listen_set;
      int s;
      int i;

      if (!is_daemon) {
            return open_sockets_inetd();
      }

            
#ifdef HAVE_ATEXIT
      {
            static int atexit_set;
            if(atexit_set == 0) {
                  atexit_set=1;
                  atexit(killkids);
            }
      }
#endif

      /* Stop zombies */
      CatchChild();
            
            
      FD_ZERO(&listen_set);

      if(lp_interfaces() && lp_bind_interfaces_only()) {
            /* We have been given an interfaces line, and been 
               told to only bind to those interfaces. Create a
               socket per interface and bind to only these.
            */
            
            if(num_interfaces > FD_SETSIZE) {
                  DEBUG(0,("open_sockets: Too many interfaces specified to bind to. Number was %d \
max can be %d\n", 
                         num_interfaces, FD_SETSIZE));
                  return False;
            }
            
            /* Now open a listen socket for each of the
               interfaces. */
            for(i = 0; i < num_interfaces; i++) {
                  struct in_addr *ifip = iface_n_ip(i);
                  
                  if(ifip == NULL) {
                        DEBUG(0,("open_sockets: interface %d has NULL IP address !\n", i));
                        continue;
                  }
                  s = fd_listenset[i] = open_socket_in(SOCK_STREAM, port, 0, ifip->s_addr, True);
                  if(s == -1)
                        return False;

                  /* ready to listen */
                  set_socket_options(s,"SO_KEEPALIVE"); 
                  set_socket_options(s,user_socket_options);

                  if (listen(s, 5) == -1) {
                        DEBUG(0,("listen: %s\n",strerror(errno)));
                        close(s);
                        return False;
                  }
                  FD_SET(s,&listen_set);
            }
      } else {
            /* Just bind to 0.0.0.0 - accept connections
               from anywhere. */
            num_interfaces = 1;
            
            /* open an incoming socket */
            s = open_socket_in(SOCK_STREAM, port, 0,
                           interpret_addr(lp_socket_address()),True);
            if (s == -1)
                  return(False);
            
            /* ready to listen */
            set_socket_options(s,"SO_KEEPALIVE"); 
            set_socket_options(s,user_socket_options);

            if (listen(s, 5) == -1) {
                  DEBUG(0,("open_sockets: listen: %s\n",
                         strerror(errno)));
                  close(s);
                  return False;
            }
            
            fd_listenset[0] = s;
            FD_SET(s,&listen_set);
      } 

      /* now accept incoming connections - forking a new process
         for each incoming connection */
      DEBUG(2,("waiting for a connection\n"));
      while (1) {
            fd_set lfds;
            int num;
            
            /* Free up temporary memory from the main smbd. */
            lp_talloc_free();

            /* Ensure we respond to PING and DEBUG messages from the main smbd. */
            message_dispatch();

            memcpy((char *)&lfds, (char *)&listen_set, 
                   sizeof(listen_set));
            
            num = sys_select(FD_SETSIZE,&lfds,NULL,NULL,NULL);
            
            if (num == -1 && errno == EINTR) {
                  if (got_sig_term) {
                        exit_server("Caught TERM signal");
                  }

                  /* check for sighup processing */
                  if (reload_after_sighup) {
                        DEBUG(0,("Got SIGHUP\n"));
                        change_to_root_user();
                        DEBUG(1,("Reloading services after SIGHUP\n"));
                        reload_services(False);
                        reload_after_sighup = False;
                  }

                  continue;
            }
            
            /* check if we need to reload services */
            check_reload(time(NULL));

            /* Find the sockets that are read-ready -
               accept on these. */
            for( ; num > 0; num--) {
                  struct sockaddr addr;
                  socklen_t in_addrlen = sizeof(addr);

                  s = -1;
                  for(i = 0; i < num_interfaces; i++) {
                        if(FD_ISSET(fd_listenset[i],&lfds)) {
                              s = fd_listenset[i];
                              /* Clear this so we don't look
                                 at it again. */
                              FD_CLR(fd_listenset[i],&lfds);
                              break;
                        }
                  }

                  smbd_set_server_fd(accept(s,&addr,&in_addrlen));
                  
                  if (smbd_server_fd() == -1 && errno == EINTR)
                        continue;
                  
                  if (smbd_server_fd() == -1) {
                        DEBUG(0,("open_sockets: accept: %s\n",
                               strerror(errno)));
                        continue;
                  }
            
                  if (smbd_server_fd() != -1 && interactive)
                        return True;
      
                  if (allowable_number_of_smbd_processes() && smbd_server_fd() != -1 && sys_fork()==0) {
                        /* Child code ... */
                        
                        /* close the listening socket(s) */
                        for(i = 0; i < num_interfaces; i++)
                              close(fd_listenset[i]);
                        
                        /* close our standard file
                           descriptors */
                        close_low_fds();
                        am_parent = 0;
                        
                        set_socket_options(smbd_server_fd(),"SO_KEEPALIVE");
                        set_socket_options(smbd_server_fd(),user_socket_options);
                        
                        /* Reset global variables in util.c so
                           that client substitutions will be
                           done correctly in the process.  */
                        reset_globals_after_fork();

                        /* tdb needs special fork handling */
                        tdb_reopen_all();

                        return True; 
                  }
                  /* The parent doesn't need this socket */
                  close(smbd_server_fd()); 

                  /* Sun May 6 18:56:14 2001 ackley@cs.unm.edu:
                        Clear the closed fd info out of server_fd --
                        and more importantly, out of client_fd in
                        util_sock.c, to avoid a possible
                        getpeername failure if we reopen the logs
                        and use %I in the filename.
                  */

                  smbd_set_server_fd(-1);

                  /* Force parent to check log size after
                   * spawning child.  Fix from
                   * klausr@ITAP.Physik.Uni-Stuttgart.De.  The
                   * parent smbd will log to logserver.smb.  It
                   * writes only two messages for each child
                   * started/finished. But each child writes,
                   * say, 50 messages also in logserver.smb,
                   * begining with the debug_count of the
                   * parent, before the child opens its own log
                   * file logserver.client. In a worst case
                   * scenario the size of logserver.smb would be
                   * checked after about 50*50=2500 messages
                   * (ca. 100kb).
                   * */
                  force_check_log_size();
 
            } /* end for num */
      } /* end while 1 */

/* NOTREACHED     return True; */
}

/****************************************************************************
 Reload the services file.
 **************************************************************************/

BOOL reload_services(BOOL test)
{
      BOOL ret, save_def = True;
      
      if (lp_loaded()) {
            pstring fname;
            pstrcpy(fname,lp_configfile());
            if (file_exist(fname,NULL) && !strcsequal(fname,servicesf)) {
                  pstrcpy(servicesf,fname);
                  test = False;
            }
            save_def = False;
      }

      reopen_logs();

      if (test && !lp_file_list_changed())
            return(True);

      lp_killunused(conn_snum_used);
      
      ret = lp_load(servicesf,False,save_def,True);

      load_printers();

      /* perhaps the config filename is now set */
      if (!test)
            reload_services(True);

      reopen_logs();

      load_interfaces();

      {
            if (smbd_server_fd() != -1) {      
                  set_socket_options(smbd_server_fd(),"SO_KEEPALIVE");
                  set_socket_options(smbd_server_fd(),user_socket_options);
            }
      }

      mangle_reset_cache();
      reset_stat_cache();

      /* this forces service parameters to be flushed */
      set_current_service(NULL,True);

      return(ret);
}

#if DUMP_CORE
/*******************************************************************
 Prepare to dump a core file - carefully !
********************************************************************/

static BOOL dump_core(void)
{
      char *p;
      pstring dname;
      pstrcpy(dname,lp_logfile());
      if ((p=strrchr(dname,'/'))) *p=0;
      pstrcat(dname,"/corefiles");
      mkdir(dname,0700);
      sys_chown(dname,getuid(),getgid());
      chmod(dname,0700);
      if (chdir(dname)) return(False);
      umask(~(0700));

#ifdef HAVE_GETRLIMIT
#ifdef RLIMIT_CORE
      {
            struct rlimit rlp;
            getrlimit(RLIMIT_CORE, &rlp);
            rlp.rlim_cur = MAX(4*1024*1024,rlp.rlim_cur);
            setrlimit(RLIMIT_CORE, &rlp);
            getrlimit(RLIMIT_CORE, &rlp);
            DEBUG(3,("Core limits now %d %d\n",
                   (int)rlp.rlim_cur,(int)rlp.rlim_max));
      }
#endif
#endif


      DEBUG(0,("Dumping core in %s\n",dname));
      abort();
      return(True);
}
#endif

/****************************************************************************
update the current smbd process count
****************************************************************************/

static BOOL process_count_update_successful = False;

int32 increment_smbd_process_count(void)
{
      int32 total_smbds;

      if (lp_max_smbd_processes()) {
            total_smbds = 0;
            if (tdb_change_int32_atomic(conn_tdb_ctx(), "INFO/total_smbds", &total_smbds, 1) == -1)
                  return 1;
            process_count_update_successful = True;
            return total_smbds + 1;
      }
      return 1;
}

static void decrement_smbd_process_count(void)
{
      int32 total_smbds;

      if (lp_max_smbd_processes() && process_count_update_successful) {
            total_smbds = 1;
            tdb_change_int32_atomic(conn_tdb_ctx(), "INFO/total_smbds", &total_smbds, -1);
      }
}

/****************************************************************************
 Exit the server.
****************************************************************************/

void exit_server(const char *reason)
{
      static int firsttime=1;
      extern char *last_inbuf;


      if (!firsttime) exit(0);
      firsttime = 0;

      change_to_root_user();
      DEBUG(2,("Closing connections\n"));

      conn_close_all();

      invalidate_all_vuids();

      /* delete our entry in the connections database. */
      if (lp_status(-1))
            yield_connection(NULL,"");

      respond_to_all_remaining_local_messages();
      decrement_smbd_process_count();

#ifdef WITH_DFS
      if (dcelogin_atmost_once) {
            dfs_unlogin();
      }
#endif

      if (!reason) {   
            int oldlevel = DEBUGLEVEL;
            DEBUGLEVEL = 10;
            DEBUG(0,("Last message was %s\n",smb_fn_name(last_message)));
            if (last_inbuf)
                  show_msg(last_inbuf);
            DEBUGLEVEL = oldlevel;
            DEBUG(0,("===============================================================\n"));
#if DUMP_CORE
            if (dump_core()) return;
#endif
      }    

      locking_end();

      DEBUG(3,("Server exit (%s)\n", (reason ? reason : "")));
      exit(0);
}

/****************************************************************************
 Initialise connect, service and file structs.
****************************************************************************/

static void init_structs(void )
{
      /*
       * Set the machine NETBIOS name if not already
       * set from the config file.
       */

      if (!*global_myname) {
            char *p;
            fstrcpy( global_myname, myhostname() );
            p = strchr( global_myname, '.' );
            if (p) 
                  *p = 0;
      }

      strupper( global_myname );

      conn_init();

      file_init();

      /* for RPC pipes */
      init_rpc_pipe_hnd();

      init_dptrs();

      secrets_init();
}

/****************************************************************************
  Keep track of the number of running smbd's. This functionality is used to
  'hard' limit Samba overhead on resource constrained systems. 
  This function is only called once per smbd.
****************************************************************************/

static BOOL smbd_process_limit(void)
{
      int32  total_smbds;
      
      if (lp_max_smbd_processes()) {

            /* Always add one to the smbd process count, as exit_server() always
             * subtracts one.
             */

            if (!conn_tdb_ctx()) {
                  DEBUG(0,("smbd_process_limit: max smbd processes parameter set with status parameter not \
set. Ignoring max smbd restriction.\n"));
                  return False;
            }

            total_smbds = increment_smbd_process_count();
            return total_smbds > lp_max_smbd_processes();
      }
      else
            return False;
}


/****************************************************************************
 Usage on the program.
****************************************************************************/

static void usage(char *pname)
{

      printf("Usage: %s [-DaioPh?V] [-d debuglevel] [-l log basename] [-p port]\n", pname);
      printf("       [-O socket options] [-s services file]\n");
      printf("\t-D                    Become a daemon (default)\n");
      printf("\t-a                    Append to log file (default)\n");
      printf("\t-i                    Run interactive (not a daemon)\n");
      printf("\t-o                    Overwrite log file, don't append\n");
      printf("\t-h                    Print usage\n");
      printf("\t-?                    Print usage\n");
      printf("\t-V                    Print version\n");
      printf("\t-d debuglevel         Set the debuglevel\n");
      printf("\t-l log basename.      Basename for log/debug files\n");
      printf("\t-p port               Listen on the specified port\n");
      printf("\t-O socket options     Socket options\n");
      printf("\t-s services file.     Filename of services file\n");
      printf("\n");
}

/****************************************************************************
 main program.
****************************************************************************/

 int main(int argc,char *argv[])
{
      extern BOOL append_log;
      extern BOOL AllowDebugChange;
      /* shall I run as a daemon */
      BOOL is_daemon = False;
      BOOL interactive = False;
      BOOL specified_logfile = False;
      int port = SMB_PORT;
      int opt;
      extern char *optarg;
      pstring logfile;
      
#ifdef HAVE_SET_AUTH_PARAMETERS
      set_auth_parameters(argc,argv);
#endif

      /* this is for people who can't start the program correctly */
      while (argc > 1 && (*argv[1] != '-')) {
            argv++;
            argc--;
      }

      while ( EOF != (opt = getopt(argc, argv, "O:l:s:d:Dip:h?Vaof:")) )
            switch (opt)  {
            case 'O':
                  pstrcpy(user_socket_options,optarg);
                  break;

            case 's':
                  pstrcpy(servicesf,optarg);
                  break;

            case 'l':
                  specified_logfile = True;
                  slprintf(logfile, sizeof(logfile)-1, "%s/log.smbd", optarg);
                  lp_set_logfile(logfile);
                  break;

            case 'a':
                  append_log = True;
                  break;

            case 'o':
                  append_log = False;
                  break;

            case 'D':
                  is_daemon = True;
                  break;

            case 'i':
                  interactive = True;
                  break;

            case 'd':
                  if (*optarg == 'A')
                        DEBUGLEVEL = 10000;
                  else
                        DEBUGLEVEL = atoi(optarg);
                  AllowDebugChange = False;
                  break;

            case 'p':
                  port = atoi(optarg);
                  break;

            case 'h':
            case '?':
                  usage(argv[0]);
                  exit(0);
                  break;

            case 'V':
                  printf("Version %s\n",VERSION);
                  exit(0);
                  break;
            default:
                  DEBUG(0,("Incorrect program usage - are you sure the command line is correct?\n"));
                  usage(argv[0]);
                  exit(1);
            }

#ifdef HAVE_SETLUID
      /* needed for SecureWare on SCO */
      setluid(0);
#endif

      sec_init();

      append_log = True;

      TimeInit();

      if(!specified_logfile) {
            slprintf(logfile, sizeof(logfile)-1, "%s/log.smbd", LOGFILEBASE);
            lp_set_logfile(logfile);
      }

      pstrcpy(remote_machine, "smbd");

      /*
       * Only want interactive behaviour if the user has not also
       * specified a logfile dir etc.
       */
      setup_logging(argv[0],interactive & !specified_logfile);

      charset_initialise();

      /* we want to re-seed early to prevent time delays causing
           client problems at a later date. (tridge) */
      generate_random_buffer(NULL, 0, False);

      /* make absolutely sure we run as root - to handle cases where people
         are crazy enough to have it setuid */

      gain_root_privilege();
      gain_root_group_privilege();

      fault_setup((void (*)(void *))exit_server);
      CatchSignal(SIGTERM , SIGNAL_CAST sig_term);
      CatchSignal(SIGHUP,SIGNAL_CAST sig_hup);

      /* we are never interested in SIGPIPE */
      BlockSignals(True,SIGPIPE);

#if defined(SIGFPE)
      /* we are never interested in SIGFPE */
      BlockSignals(True,SIGFPE);
#endif

#if defined(SIGUSR2)
      /* We are no longer interested in USR2 */
      BlockSignals(True,SIGUSR2);
#endif

      /* POSIX demands that signals are inherited. If the invoking process has
       * these signals masked, we will have problems, as we won't recieve them. */
      BlockSignals(False, SIGHUP);
      BlockSignals(False, SIGUSR1);
      BlockSignals(False, SIGTERM);

      /* we want total control over the permissions on created files,
         so set our umask to 0 */
      umask(0);

      init_sec_ctx();
      init_conn_ctx();

      reopen_logs();

      DEBUG(0,( "smbd version %s started.\n", VERSION));
      DEBUGADD(0,( "Copyright Andrew Tridgell and the Samba Team 1992-2002\n"));

      DEBUG(2,("uid=%d gid=%d euid=%d egid=%d\n",
             (int)getuid(),(int)getgid(),(int)geteuid(),(int)getegid()));

      if (sizeof(uint16) < 2 || sizeof(uint32) < 4) {
            DEBUG(0,("ERROR: Samba is not configured correctly for the word size on your machine\n"));
            exit(1);
      }

      /*
       * Do this before reload_services.
       */

      if (!reload_services(False))
            return(-1); 

      init_structs();
      
#ifdef WITH_PROFILE
      if (!profile_setup(False)) {
            DEBUG(0,("ERROR: failed to setup profiling shared memory\n"));
            return -1;
      }
#endif /* WITH_PROFILE */

#ifdef WITH_SSL
      {
            extern BOOL sslEnabled;
            sslEnabled = lp_ssl_enabled();
            if(sslEnabled)
                  sslutil_init(True);
      }
#endif        /* WITH_SSL */

      codepage_initialise(lp_client_code_page());

      fstrcpy(global_myworkgroup, lp_workgroup());

      DEBUG(3,( "loaded services\n"));

      if (!is_daemon && !is_a_socket(0)) {
            if (!interactive)
                  DEBUG(0,("standard input is not a socket, assuming -D option\n"));

            /*
             * Setting is_daemon here prevents us from eventually calling
             * the open_sockets_inetd()
             */

            is_daemon = True;
      }

      if (is_daemon && !interactive) {
            DEBUG( 3, ( "Becoming a daemon.\n" ) );
            become_daemon();
      }

#if HAVE_SETPGID
      /*
       * If we're interactive we want to set our own process group for
       * signal management.
       */
      if (interactive)
            setpgid( (pid_t)0, (pid_t)0);
#endif

      if (!directory_exist(lp_lockdir(), NULL))
            mkdir(lp_lockdir(), 0755);

      if (is_daemon)
            pidfile_create("smbd");

      if (!message_init())
            exit(1);

      /* Setup the main smbd so that we can get messages. */
      if (lp_status(-1))
            claim_connection(NULL,"",0,True);

      /* Attempt to migrate from an old 2.0.x machine account file. */
      if (!migrate_from_old_password_file(global_myworkgroup))
            DEBUG(0,("Failed to migrate from old MAC file.\n"));

      if(!pdb_generate_sam_sid()) {
            DEBUG(0,("ERROR: Samba cannot create a SAM SID.\n"));
            exit(1);
      }

      if (!open_sockets(is_daemon,interactive,port))
            exit(1);

      /*
       * Everything after this point is run after the fork().
       */ 

      if (!locking_init(0))
            exit(1);

      if (!print_backend_init())
            exit(1);

      if (!share_info_db_init())
            exit(1);

      if(!initialize_password_db(False))
            exit(1);

      /* possibly reload the services file. */
      reload_services(True);

      if (*lp_rootdir()) {
            if (sys_chroot(lp_rootdir()) == 0)
                  DEBUG(2,("Changed root to %s\n", lp_rootdir()));
      }

      /* Setup oplocks */
      if (!init_oplocks())
            exit(1);

      /* Setup change notify */
      if (!init_change_notify())
            exit(1);

      if ( smbd_process_limit() ) {
              DEBUG( 1, ( "Connection denied from %s\n",
                        client_addr() ) );
              exit_server("connection denied");
      }
            
      smbd_process();
      
      exit_server("normal exit");
      return(0);
}

Generated by  Doxygen 1.6.0   Back to index