#if 0
#
# See http://fy.chalmers.se/~appro/LD_*-gallery/ for details.
#
# Following is Tru64 compiler line. Pre-load by setting _RLD_LIST
# environment variable to "/path/to/bind_to.so:DEFAULT" and BIND_TO
# environment variable - to interface name of interest, e.g.:
#
# env _RLD_LIST=`pwd`/bind_to.so:DEFAULT BIND_TO=virtual daemon
#
/bin/sh << EOS
MODNAME=\`basename "$0" .c\`
case `uname -s` in
OSF1)
(set -x;
 cc -O -shared -o \$MODNAME.so "$0" -B symbolic -init my_init -hidden_symbol my_init
);;
SunOS)
(set -x;
 cc -O -Kpic -G -z text -o \$MODNAME.so "$0" -lsocket -lnsl
);;
esac
EOS
exit
#endif

#define gethostname	__gethostname
#define gethostbyaddr	__gethostbyaddr
#define sysinfo		__sysinfo
#define socket		__socket
#define bind		__bind
#define connect		__connect
#define sendto		__sendto
#define listen		__listen
#define uname		__uname

#ifdef __sun
#define __gethostname	_gethostname
#define __gethostbyaddr	_gethostbyaddr
#define __sysinfo	_sysinfo
#define __socket	_socket
#define __bind		_bind
#define __connect	_connect
#define __sendto	_sendto
#define __listen	_listen
#define __uname		_uname
#endif

#include <sys/socket.h>
#include <unistd.h>
#include <sys/utsname.h>
#include <sys/systeminfo.h>
#include <netdb.h>

#undef uname
#undef listen
#undef sendto
#undef connect
#undef bind
#undef socket
#undef sysinfo
#undef gethostbyaddr
#undef gethostname

#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <sys/types.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <ctype.h>
#include <dlfcn.h>

static fd_set socket_set;
static struct sockaddr_in myself;
static char *hostname;

#ifdef __sun
#undef __gethostbyaddr
#define __gethostbyaddr	gethostbyaddr_libnsl
struct hostent *(*__gethostbyaddr) (const char *name, int len, int type);
#endif

#if defined(__SUNPRO_C)
#pragma init(my_init)  /* SPARCCompiler specific #pragma */
static
#endif
void my_init ()
{ char *env=getenv("BIND_TO");
  struct hostent *ret;

#ifdef __sun
  void *libnsl;

    libnsl = dlopen ("libnsl.so.1",RTLD_LAZY);
    if (libnsl == NULL)
	fprintf (stderr,"Cannot dlopen(\"libnsl.so.1\")\n"), exit (255);

    __gethostbyaddr = (struct hostent *(*)(const char *,int,int))
				dlsym (libnsl, "gethostbyaddr");
    if (__gethostbyaddr == NULL)
	fprintf (stderr,"Cannot dlsym(\"gethostbyname\")\n"), exit (255); 
#endif

    if (env==NULL)
	fprintf (stderr,"${BIND_TO} is undefined\n"), exit(255);

    if (!(ret=gethostbyname (env)))
	fprintf (stderr,"unable to gethostbyname(\"%s\")\n",env), exit(255);

    memcpy (&myself.sin_addr,ret->h_addr,sizeof(myself.sin_addr));
    myself.sin_family = AF_INET;

    if (isdigit(env[0]))
    {	ret = __gethostbyaddr ((char *)&myself.sin_addr,sizeof(myself.sin_addr),
				myself.sin_family);
	if (ret != NULL)
	    hostname = strdup (ret->h_name);
    }
    else
	hostname = strdup(env);
}

struct hostent *gethostbyaddr(const char *addr, int len, int type)
{ struct hostent *ret=__gethostbyaddr(addr,len,type);
  static struct hostent hostcopy;

    if (ret!=NULL && hostname &&
	type==myself.sin_family &&
	!memcmp (addr,&myself.sin_addr.s_addr,sizeof(myself.sin_addr)))
    {	hostcopy = *ret, ret = &hostcopy,
	ret->h_name = hostname;
    }

  return ret;
}

long sysinfo(int command, char *buf, long count)
{ long ret=__sysinfo(command, buf, count);

    if (command==SI_HOSTNAME && ret>=0 && hostname)
    {	if (count>0)
	    strncpy (buf,hostname,count-1), buf[count-1]='\0';
	return strlen (hostname) + 1;
    }

  return ret;
}

int gethostname(char *name, int len)
{ long ret=__sysinfo(SI_HOSTNAME, name, len);

    if (ret>=0 && hostname)
    	strncpy (name,hostname,len);

  return ret==-1?-1:0;
}

int uname (struct utsname *name)
{ int ret=__uname (name);

    if (ret>=0 && hostname)
	strncpy (name->nodename,hostname,SYS_NMLN);

  return ret;
}

int socket (int domain, int type, int protocol)
{ int s = __socket (domain,type,protocol);

    if (s>=0 && s<FD_SETSIZE && domain && domain==myself.sin_family)
	FD_SET (s,&socket_set);

  return s;
}

int listen (int s, int log)
{   if (s>=0 && s<FD_SETSIZE && FD_ISSET(s,&socket_set))
	FD_CLR (s,&socket_set);

  return __listen (s,log);
}

int bind (int s, const struct sockaddr *addr, int len)
{ struct sockaddr_in copy;

    if (s>=0 && s<FD_SETSIZE && FD_ISSET(s,&socket_set))
    {	FD_CLR (s,&socket_set);
	copy = *(struct sockaddr_in *)addr;
	if (copy.sin_family == myself.sin_family &&
	    copy.sin_addr.s_addr == INADDR_ANY)
	{   copy.sin_addr = myself.sin_addr;
	    return __bind (s,(struct sockaddr *)&copy,sizeof(copy));
	}
    }

  return __bind (s,addr,len);
}

int connect (int s, const struct sockaddr *addr, int len)
{   if (s>=0 && s<FD_SETSIZE && FD_ISSET(s,&socket_set))
    {	FD_CLR (s,&socket_set);
	__bind (s,(struct sockaddr *)&myself,sizeof(myself));
    }

  return __connect (s,addr,len);
}

ssize_t sendto (int s, const void *msg, size_t mlen, int f,
		const struct sockaddr *addr, int alen)
{   if (s>=0 && s<FD_SETSIZE && FD_ISSET(s,&socket_set))
    {	FD_CLR (s,&socket_set);
	__bind (s,(struct sockaddr *)&myself,sizeof(myself));
    }

  return __sendto (s,msg,mlen,f,addr,alen);
}