text: /*
   * %CopyrightBegin%
   * 
   * Copyright Ericsson AB 1997-2016. All Rights Reserved.
   * 
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   * 
   * %CopyrightEnd%
   *
   */
  
  /* An exception from using eidef.h, use config.h directly */
  #include "config.h"
  
  #include <stdlib.h>
  #include <sys/types.h>
  #include <fcntl.h>
  
  #ifdef __WIN32__
  #include <winsock2.h>
  #include <windows.h>
  #include <winbase.h>
  
  #elif VXWORKS
  #include <stdio.h>
  #include <string.h>
  #include <vxWorks.h>
  #include <hostLib.h>
  #include <selectLib.h>
  #include <ifLib.h>
  #include <sockLib.h>
  #include <taskLib.h>
  #include <inetLib.h>
  #include <unistd.h>
  #include <sys/socket.h>
  #include <netinet/in.h>
  #include <netinet/tcp.h>
  #include <symLib.h>
  #include <sysSymTbl.h>
  #include <sysLib.h>
  #include <tickLib.h>
  
  #if TIME_WITH_SYS_TIME
  # include <sys/time.h>
  # include <time.h>
  #else
  # if HAVE_SYS_TIME_H
  #  include <sys/time.h>
  # else
  #  include <time.h>
  # endif
  #endif
  
  #include <a_out.h>
  
  /* #include "netdb.h" */
  #else /* other unix */
  #include <errno.h>
  #include <netdb.h>
  #include <netinet/in.h>
  #include <arpa/inet.h>
  #include <signal.h>
  #include <stdio.h>
  #include <string.h>
  #include <sys/param.h>
  #include <sys/socket.h>
  #include <sys/stat.h>
  #include <sys/wait.h>
  #include <sys/time.h>
  #include <time.h>
  #include <unistd.h>
  #include <sys/types.h>
  #include <signal.h>
  #endif
  
  #include "ei.h"
  #include "ei_resolve.h"
  #include "erl_start.h"
  
  /* FIXME is this a case a vfork can be used? */
  #if !HAVE_WORKING_VFORK
  # define vfork fork
  #endif
  
  #ifndef MAXPATHLEN
  #define MAXPATHLEN 1024
  #endif
  
  #ifndef RSH
  #define RSH "/usr/bin/ssh"
  #endif
  
  #ifndef HAVE_SOCKLEN_T
  typedef int SocklenType;
  #else
  typedef socklen_t SocklenType;
  #endif
  
  /* FIXME check errors from malloc */
  
  static struct in_addr *get_addr(const char *hostname, struct in_addr *oaddr);
  
  static int wait_for_erlang(int sockd, int magic, struct timeval *timeout);
  #if defined(VXWORKS) || defined(__WIN32__)
  static int unique_id(void);
  static unsigned long spawn_erlang_epmd(ei_cnode *ec,
  				       char *alive,
  				       Erl_IpAddr adr,
  				       int flags,
  				       char *erl_or_epmd,
  				       char *args[],
  				       int port,
  				       int is_erlang);
  #else
  static int exec_erlang(ei_cnode *ec, char *alive, Erl_IpAddr adr, int flags,
  		       char *erl, char *args[],int port);
  #endif
  /* Start an Erlang node. return value 0 indicates that node was
   * started successfully, negative values indicate error. 
   * 
   * node -  the name of the remote node to start (alivename@hostname).
   * flags - turn on or off certain options. See erl_start.h for a list.
   * erl -  is the name of the erl script to call. If NULL, the default
   * name "erl" will be used.
   * args - a NULL-terminated list of strings containing
   * additional arguments to be sent to the remote Erlang node. These
   * strings are simply appended to the end of the command line, so any
   * quoting of special characters, etc must be done by the caller.
   * There may be some conflicts between some of these arguments and the
   * default arguments hard-coded into this function, so be careful. 
   */
  int erl_start_sys(ei_cnode *ec, char *alive, Erl_IpAddr adr, int flags,
  		  char *erl, char *args[])
  {
    struct timeval timeout;
    struct sockaddr_in addr;
    SocklenType namelen;
    int port;
    int sockd = 0;
    int one = 1;
  #if defined(VXWORKS) || defined(__WIN32__)
    unsigned long pid = 0;
  #else
    int pid = 0;
  #endif
    int r = 0;
  
    if (((sockd = socket(AF_INET, SOCK_STREAM, 0)) < 0) ||
        (setsockopt(sockd, SOL_SOCKET, SO_REUSEADDR, (char *)&one, sizeof(one)) < 0)) {
      r = ERL_SYS_ERROR;
      goto done;
    }
  
    memset(&addr,0,sizeof(addr));
    addr.sin_family = AF_INET;
    addr.sin_addr.s_addr = htonl(INADDR_ANY);
    addr.sin_port = 0;
  
    if (bind(sockd,(struct sockaddr *)&addr,sizeof(addr))<0) {
        return ERL_SYS_ERROR;
    }
    namelen = sizeof(addr);
    if (getsockname(sockd,(struct sockaddr *)&addr,&namelen)<0) {
        return ERL_SYS_ERROR;
    }
    port = ntohs(addr.sin_port);
  
    listen(sockd,5);
  
  #if defined(VXWORKS) || defined(__WIN32__)
    if((pid = spawn_erlang_epmd(ec,alive,adr,flags,erl,args,port,1))
        == 0)
       return ERL_SYS_ERROR;
    timeout.tv_usec = 0;
    timeout.tv_sec = 10; /* ignoring ERL_START_TIME */
    if((r = wait_for_erlang(sockd,unique_id(),&timeout))
       == ERL_TIMEOUT) {
  #if defined(VXWORKS)
        taskDelete((int) pid);
        if(taskIdVerify((int) pid) != ERROR)
  	  taskDeleteForce((int) pid);
  #else /* Windows */
        /* Well, this is not a nice way to do it, and it does not 
  	 always kill the emulator, but the alternatives are few.*/
        TerminateProcess((HANDLE) pid,1);
  #endif /* defined(VXWORKS) */
    }
  #else /* Unix */
    switch ((pid = fork())) {
    case -1:
      r = ERL_SYS_ERROR;
      break;
  
    case 0:
      /* child - start the erlang node */
      exec_erlang(ec, alive, adr, flags, erl, args, port);
  
      /* error if reached - parent reports back to caller after timeout
         so we just exit here */
      exit(1);
      break;
  
    default:
  
      /* parent - waits for response from Erlang node */
      /* child pid used here as magic number */
      timeout.tv_usec = 0;
      timeout.tv_sec = 10; /* ignoring ERL_START_TIME */
      if ((r = wait_for_erlang(sockd,pid,&timeout)) == ERL_TIMEOUT) {
        /* kill child if no response */
        kill(pid,SIGINT);
        sleep(1);
        if (waitpid(pid,NULL,WNOHANG) != pid) {
  	/* no luck - try harder */
  	kill(pid,SIGKILL);
  	sleep(1);
  	waitpid(pid,NULL,WNOHANG);
        }
      }
  
    }
  #endif /* defined(VXWORKS) || defined(__WIN32__) */
  
  done:
  #if defined(__WIN32__)
    if (sockd) closesocket(sockd);
  #else
    if (sockd) close(sockd);
  #endif
    return r;
  } /* erl_start_sys() */
  
  #if defined(VXWORKS) || defined(__WIN32__)
  #if defined(VXWORKS)
  #define DEF_ERL_COMMAND ""
  #define DEF_EPMD_COMMAND ""
  #define ERLANG_SYM "start_erl"
  #define EPMD_SYM "start_epmd"
  #define ERL_REPLY_FMT   "-s erl_reply reply %s %d %d"
  #else
  #define DEF_ERL_COMMAND "erl"
  #define DEF_EPMD_COMMAND "epmd"
  #define ERL_REPLY_FMT   "-s erl_reply reply \"%s\" \"%d\" \"%d\""
  #endif
  #define ERL_NAME_FMT    "-noinput -name %s"
  #define ERL_SNAME_FMT   "-noinput -sname %s"
  
  #define IP_ADDR_CHARS 15
  #define FORMATTED_INT_LEN 10
  
  static int unique_id(void){
  #if defined(VXWORKS)
      return taskIdSelf();
  #else
      return (int) GetCurrentThreadId();
  #endif
  }
  
  static int enquote_args(char **oargs, char ***qargs){
      char **args;
      int len;
      int i;
      int qwhole;
      int extra;
      char *ptr;
      char *ptr2;
  
      if(oargs == NULL){
  	*qargs = malloc(sizeof(char *));
  	**qargs = NULL;
  	return 0;
      };
  
      for(len=0;oargs[len] != NULL; ++len)
  	;
      args = malloc(sizeof(char *) * (len + 1));
  
      for(i = 0; i < len; ++i){
  	qwhole = strchr(oargs[i],' ') != NULL;
  	extra = qwhole * 2;
  	for(ptr = oargs[i]; *ptr != '\0'; ++ptr)
  	    extra += (*ptr == '"');
  	args[i] = malloc(strlen(oargs[i]) +
  			     extra +
  			     1);
  	ptr2 = args[i];
  	if(qwhole)
  	    *(ptr2++) = '"';
  	for(ptr = oargs[i]; *ptr != '\0'; ++ptr){
  	    if(*ptr == '"')
  		*(ptr2++) = '\\';
  	    *(ptr2++) = *ptr;
  	}
  	if(qwhole)
  	    *(ptr2++) = '"';
  	*ptr2 = '\0';
      }
      args[len] = NULL;
      *qargs = args;
      return len;
  }
  
  static void free_args(char **args){
      char **ptr = args;
      while(*ptr != NULL)
  	free(*(ptr++));
      free(args);
  }
  
  #if defined(VXWORKS)
  static  FUNCPTR lookup_function(char *symname){
      char *value;
      SYM_TYPE type;
      if(symFindByName(sysSymTbl,
  		     symname,
  		     &value,
  		     &type) == ERROR /*|| type != N_TEXT*/)
  	return NULL;
      return (FUNCPTR) value;
  }
  #endif /* defined(VXWORKS) */
  
  /* In NT and VxWorks, we cannot fork(), Erlang and Epmd gets 
     spawned by this function instead. */
  
  static unsigned long spawn_erlang_epmd(ei_cnode *ec,
  				       char *alive,
  				       Erl_IpAddr adr,
  				       int flags,
  				       char *erl_or_epmd,
  				       char *args[],
  				       int port,
  				       int is_erlang)
  {
  #if defined(VXWORKS)
      FUNCPTR erlfunc;
  #else /* Windows */
      STARTUPINFO sinfo;
      SECURITY_ATTRIBUTES sa;
      PROCESS_INFORMATION pinfo;
  #endif
      char *cmdbuf;
      int cmdlen;
      char *ptr;
      int i;
      int num_args;
      char *name_format;
      struct in_addr myaddr;
      struct in_addr *hisaddr = (struct in_addr *)adr;
      char iaddrbuf[IP_ADDR_CHARS + 1];
      int ret;
  
      if(is_erlang){
  	get_addr(ei_thishostname(ec), &myaddr);
  #if defined(VXWORKS)
          inet_ntoa_b(myaddr, iaddrbuf);
  #else /* Windows */
  	if((ptr = inet_ntoa(myaddr)) == NULL)
  	    return 0;
  	else
  	    strcpy(iaddrbuf,ptr);
  #endif
      }
      if ((flags & ERL_START_REMOTE) ||
  	(is_erlang && (hisaddr->s_addr != myaddr.s_addr))) {
  	return 0;
      } else {
  	num_args = enquote_args(args, &args);
  	for(cmdlen = i = 0; args[i] != NULL; ++i)
  	    cmdlen += strlen(args[i]) + 1;
  #if !defined(VXWORKS)
  	/* On VxWorks, we dont actually run a command,
  	   we call start_erl() */
  	if(!erl_or_epmd)
  #endif
  	    erl_or_epmd = (is_erlang) ? DEF_ERL_COMMAND :
  	    DEF_EPMD_COMMAND;
  	if(is_erlang){
  	    name_format = (flags & ERL_START_LONG) ? ERL_NAME_FMT :
  		ERL_SNAME_FMT;
  	    cmdlen +=
  		strlen(erl_or_epmd) + (*erl_or_epmd != '\0') +
  		strlen(name_format) + 1 + strlen(alive) +
  		strlen(ERL_REPLY_FMT) + 1 + strlen(iaddrbuf) + 2 * FORMATTED_INT_LEN + 1;
  	    ptr = cmdbuf = malloc(cmdlen);
  	    if(*erl_or_epmd != '\0')
  		ptr += sprintf(ptr,"%s ",erl_or_epmd);
  	    ptr += sprintf(ptr, name_format,
  			   alive);
  	    ptr += sprintf(ptr, " " ERL_REPLY_FMT,
  		       iaddrbuf, port, unique_id());
  	} else { /* epmd */
  	    cmdlen += strlen(erl_or_epmd) + (*erl_or_epmd != '\0') + 1;
  	    ptr = cmdbuf = malloc(cmdlen);
  	    if(*erl_or_epmd != '\0')
  		ptr += sprintf(ptr,"%s ",erl_or_epmd);
  	    else
  		*(ptr++) = '\0';
  	}
  	for(i= 0; args[i] != NULL; ++i){
  	    *(ptr++) = ' ';
  	    strcpy(ptr,args[i]);
  	    ptr += strlen(args[i]);
  	}
  	free_args(args);
  	if (flags & ERL_START_VERBOSE) {
  	    fprintf(stderr,"erl_call: commands are %s\n",cmdbuf);
  	}
  	/* OK, one single command line... */
  #if defined(VXWORKS)
  	erlfunc = lookup_function((is_erlang) ? ERLANG_SYM :
  				  EPMD_SYM);
  	if(erlfunc == NULL){
  	    if (flags & ERL_START_VERBOSE) {
  		fprintf(stderr,"erl_call: failed to find symbol %s\n",
  			(is_erlang) ? ERLANG_SYM : EPMD_SYM);
  	    }
  	    ret = 0;
  	} else {
  	/* Just call it, it spawns itself... */
  	    ret = (unsigned long) 
  		(*erlfunc)((int) cmdbuf,0,0,0,0,0,0,0,0,0);
  	    if(ret == (unsigned long) ERROR)
  		ret = 0;
  	}
  #else /* Windows */
  	/* Hmmm, hidden or unhidden window??? */
  	memset(&sinfo,0,sizeof(sinfo));
  	sinfo.cb = sizeof(STARTUPINFO); 
  	sinfo.dwFlags = STARTF_USESHOWWINDOW /*| 
  	    STARTF_USESTDHANDLES*/;
  	sinfo.wShowWindow = SW_HIDE; /* Hidden! */
  	sinfo.hStdInput = GetStdHandle(STD_INPUT_HANDLE);
  	sinfo.hStdOutput = GetStdHandle(STD_OUTPUT_HANDLE);
  	sinfo.hStdError = GetStdHandle(STD_ERROR_HANDLE);
  	sa.nLength = sizeof(sa);
  	sa.lpSecurityDescriptor = NULL;
  	sa.bInheritHandle = /*TRUE*/ FALSE;
  	if(!CreateProcess(
  			  NULL,
  			  cmdbuf,
  			  &sa,
  			  NULL,
  			  /*TRUE*/ FALSE,
  			  0 | CREATE_NEW_CONSOLE,
  			  NULL,
  			  NULL,
  			  &sinfo,
  			  &pinfo))
  	    ret = 0;
  	else
  	    ret = (unsigned long) pinfo.hProcess;
  #endif
  	free(cmdbuf);
  	return ret;
      }
      /* NOTREACHED */
  }
  #else /* Unix */
  
  /* call this from the child process to start an erlang system. This
   * function just builds the erlang command line and then calls it.
   *
   * node - the nodename for the new node
   * flags - various options that can be set (see erl_start.h)
   * erl - name of the erlang executable, or NULL for default ("erl")
   * args - additional arguments to pass to erlang executable
   * port - the port number where we wait for acknowledgment from the enode
   *
   * we have a potential problem if args conflicts with any of the 
   * arguments we use here.
   */
  static int exec_erlang(ei_cnode *ec,
  		       char *alive,
  		       Erl_IpAddr adr,
  		       int flags,
  		       char *erl,
  		       char *args[],
  		       int port)
  {
  #if !defined(__WIN32__) && !defined(VXWORKS) 
    int fd,len,l,i;
    char **s;
    char *argv[4];
    char argbuf[BUFSIZ];
    struct in_addr myaddr;
    struct in_addr *hisaddr = (struct in_addr *)adr;
  
    if (!get_addr(ei_thishostname(ec), &myaddr)) {
        fprintf(stderr,"erl_call: failed to find hostname\r\n");
        return ERL_SYS_ERROR;
    }
  
    /* on this host? */
    /* compare ip addresses, unless forced by flag setting to use rsh */
    if ((flags & ERL_START_REMOTE) || (hisaddr->s_addr != myaddr.s_addr)) {
      argv[0] = RSH;
      len = strlen(inet_ntoa(*hisaddr));
      argv[1] = malloc(len+1);
      strcpy(argv[1],inet_ntoa(*hisaddr));
    }
    else {
    /* Yes - use sh to start local Erlang */
      argv[0] = "sh";
      argv[1] = "-c";
    }
    argv[2] = argbuf;
    argv[3] = NULL;
  
    len = 0;
    *argbuf=(char)0;
  
    sprintf(argbuf,"exec %s ", (erl? erl: "erl"));
    len = strlen(argbuf);
  
    /* *must* be noinput or node (seems to) hang... */
    /* long or short names? */
    sprintf(&argbuf[len], "-noinput %s %s ",
  	  ((flags & ERL_START_LONG) ? "-name" : "-sname"),
  	  alive);
    len = strlen(argbuf);
  
    /* now make the new node report back when it's ready */
    /* add: myip, myport and replymsg */
    sprintf(&argbuf[len],
  	  "-s erl_reply reply %s %d %d ",
  	  inet_ntoa(myaddr),port,(int)getpid());
  #ifdef DEBUG
    fprintf(stderr,"erl_call: debug %s\n",&argbuf[len]);
  #endif
    len = strlen(argbuf);
  
    /* additional arguments to be passed to the other system */
    /* make sure that they will fit first */
    for (l=0, s = args; s && *s; s++) l+= strlen(*s) + 1;
  
    if (len + l + 1 > BUFSIZ) return ERL_BADARG;
    else {
      for (s = args; s && *s; s++) {
        strcat(argbuf," ");
        strcat(argbuf,*s);
      }
      len += l + 1;
    }
  
    if (flags & ERL_START_VERBOSE) {
      fprintf(stderr,"erl_call: %s %s %s\n",argv[0],argv[1],argv[2]);
    }
  
    /* close all descriptors in child */
    for (i=0; i<64; i++) close(i);
  
    /* debug output to file? */
    if (flags & ERL_START_DEBUG) {
      char debugfile[MAXPATHLEN+1];
      char *home=getenv("HOME");
      sprintf(debugfile,"%s/%s.%s",home,ERL_START_LOGFILE,alive);
      if ((fd=open(debugfile, O_WRONLY | O_CREAT | O_APPEND, 0644)) >= 0) {
        time_t t = time(NULL);
        dup2(fd,1);
        dup2(fd,2);
        fprintf(stderr,"\n\n===== Log started ======\n%s \n",ctime(&t));
        fprintf(stderr,"erl_call: %s %s %s\n",argv[0],argv[1],argv[2]);
      }
    }
  
    /* start the system */
    execvp(argv[0], argv);
  
    if (flags & ERL_START_DEBUG) {
      fprintf(stderr,"erl_call: exec failed: (%d) %s %s %s\n",
  	    errno,argv[0],argv[1],argv[2]);
    }
  
  #endif
    /* (hopefully) NOT REACHED */
    return ERL_SYS_ERROR;
  } /* exec_erlang() */
  
  #endif /* defined(VXWORKS) || defined(WINDOWS) */
  
  #if defined(__WIN32__)
  static void gettimeofday(struct timeval *now,void *dummy){
      SYSTEMTIME systime;
  	FILETIME ft;
      DWORD x;
      GetSystemTime(&systime);
      SystemTimeToFileTime(&systime,&ft);
      x = ft.dwLowDateTime / 10;
      now->tv_sec = x / 1000000;
      now->tv_usec = x % 1000000;
  }
  
  #elif defined(VXWORKS)
  static void gettimeofday(struct timeval *now, void *dummy){
      int rate = sysClkRateGet(); /* Ticks per second */
      unsigned long ctick = tickGet();
      now->tv_sec = ctick / rate; /* secs since reboot */
      now->tv_usec = ((ctick - (now->tv_sec * rate))*1000000)/rate;
  }
  #endif
  
  
  /* wait for the remote system to reply */
  /*
   * sockd - an open socket where we expect a connection from the e-node
   * magic - sign on message the e-node must provide for verification
   * timeout - how long to wait before returning failure
   *
   * OBS: the socket is blocking, and there is a potential deadlock if we
   * get an accept but the peer sends no data (and does not close).
   * in normal cases the timeout will work ok however, i.e. either we
   * never get any connection, or we get connection then close().
   */
  static int wait_for_erlang(int sockd, int magic, struct timeval *timeout)
  {
    struct timeval to;
    struct timeval stop_time;
    struct timeval now;
    fd_set rdset;
    int fd;
    int n,i;
    char buf[16];
    struct sockaddr_in peer;
    SocklenType len = (SocklenType) sizeof(peer);
  
    /* determine when we should exit this function */
    gettimeofday(&now,NULL);
    stop_time.tv_sec = now.tv_sec + timeout->tv_sec;
    stop_time.tv_usec = now.tv_usec + timeout->tv_usec;
    while (stop_time.tv_usec > 1000000) {
      stop_time.tv_sec++;
      stop_time.tv_usec -= 1000000;
    }
  
  #ifdef DEBUG
    fprintf(stderr,"erl_call: debug time is %ld.%06ld, "
  	  "will timeout at %ld.%06ld\n",
  	  now.tv_sec,now.tv_usec,stop_time.tv_sec,stop_time.tv_usec);
  #endif
  
    while (1) {
      FD_ZERO(&rdset);
      FD_SET(sockd,&rdset);
  
      /* adjust the timeout to (stoptime - now) */
      gettimeofday(&now,NULL);
      to.tv_sec = stop_time.tv_sec - now.tv_sec;
      to.tv_usec = stop_time.tv_usec - now.tv_usec;
      while ((to.tv_usec < 0) && (to.tv_sec > 0)) {
        to.tv_usec += 1000000;
        to.tv_sec--;
      }
      if (to.tv_sec < 0) return ERL_TIMEOUT;
  
  #ifdef DEBUG
      fprintf(stderr,"erl_call: debug remaining to timeout: %ld.%06ld\n",
  	    to.tv_sec,to.tv_usec);
  #endif
      switch ((i = select(sockd+1,&rdset,NULL,NULL,&to))) {
      case -1:
        return ERL_SYS_ERROR;
        break;
  
      case 0: /* timeout */
  #ifdef DEBUG
        gettimeofday(&now,NULL);
        fprintf(stderr,"erl_call: debug timed out at %ld.%06ld\n",
  	      now.tv_sec,now.tv_usec);
  #endif
        return ERL_TIMEOUT;
        break;
  
      default: /* ready descriptors */
  #ifdef DEBUG
        gettimeofday(&now,NULL);
        fprintf(stderr,"erl_call: debug got select at %ld.%06ld\n",
  	      now.tv_sec,now.tv_usec);
  #endif
        if (FD_ISSET(sockd,&rdset)) {
  	if ((fd = accept(sockd,(struct sockaddr *)&peer,&len)) < 0)
  	  return ERL_SYS_ERROR;
  
  	/* now get sign-on message and terminate it */
  #if defined(__WIN32__)
  	if ((n=recv(fd,buf,16,0)) >= 0) buf[n]=0x0;
  	closesocket(fd);
  #else
  	if ((n=read(fd,buf,16)) >= 0) buf[n]=0x0;
  	close(fd);
  #endif
  #ifdef DEBUG
  	fprintf(stderr,"erl_call: debug got %d, expected %d\n",
  		atoi(buf),magic);
  #endif
  	if (atoi(buf) == magic) return 0; /* success */
        } /* if FD_SET */
      } /* switch */
    } /* while */
  
    /* unreached? */
    return ERL_SYS_ERROR;
  } /* wait_for_erlang() */
  
  
  static struct in_addr *get_addr(const char *hostname, struct in_addr *oaddr)
  {
    struct hostent *hp;
  
  #if !defined (__WIN32__)
    char buf[1024];
    struct hostent host;
    int herror;
  
    hp = ei_gethostbyname_r(hostname,&host,buf,1024,&herror);
  #else
    hp = ei_gethostbyname(hostname);
  #endif
  
    if (hp) {
      memmove(oaddr,hp->h_addr_list[0],sizeof(*oaddr));
      return oaddr;
    }
    return NULL;
  }
  