scsh-0.6/scsh/network1.c

/* 
 * Scheme48/scsh network interface.
 * Routines that require custom C support.
 * Copyright (c) 1994 by Brian D. Carlstrom
 * Copyright (c) 1994 by Olin Shivers
 */

#include "cstuff.h"
#include <sys/types.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <errno.h>
#include <netdb.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <string.h>
#include <stdio.h>
#include <fcntl.h>
/* Make sure our exports match up w/the implementation: */
#include "network1.h"
#include "scheme48.h"
//extern int h_errno;

/* to extract a 4 byte long value from a scheme string */

#define GET_LONG(x,n) (*((u_long *)(S48_ADDRESS_AFTER_HEADER((x),unsigned char)+(n*4))))

#define SET_LONG(x,n,v) GET_LONG((x),(n))=(u_long)(v);

s48_value long2byte_vector (long number)
{
  s48_value bv = s48_make_byte_vector (4, 0);
  S48_BYTE_VECTOR_SET(bv, 0, number & 0xff);
  S48_BYTE_VECTOR_SET(bv, 1, (number >> 8) & 0xff);
  S48_BYTE_VECTOR_SET(bv, 2, (number >> 16) & 0xff);
  S48_BYTE_VECTOR_SET(bv, 3, (number >> 24) & 0xff);
  return bv;
}

long byte_vector2long (s48_value bv)
{
  long number = S48_BYTE_VECTOR_REF (bv, 0);
  number |=  (S48_BYTE_VECTOR_REF (bv, 1) << 8);
  number |=  (S48_BYTE_VECTOR_REF (bv, 2) << 16);
  number |=  (S48_BYTE_VECTOR_REF (bv, 3) << 24);
  return number;
}

/*-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-*/
s48_value scheme_bind(s48_value sock, s48_value family, s48_value scheme_name)
{
  int sockfd = s48_extract_fixnum (sock);
  switch(s48_extract_fixnum (family))
    {
    case AF_UNIX: 
      {
	struct sockaddr_un name;
	int scheme_length=S48_STRING_LENGTH(scheme_name);
	
	name.sun_family=AF_UNIX;	
	if (scheme_length>=(108-1)) /* save space for \0 */
	  return(-1);  // TODO: check this in scheme !
	strncpy(name.sun_path,
		s48_extract_string(scheme_name),
		scheme_length);	/* copy to c string */
	name.sun_path[scheme_length]='\0'; /* add null */
	if ( bind(sockfd,(struct sockaddr *)&name,sizeof(name)) < 0)
	  s48_raise_os_error (errno);
	return S48_UNSPECIFIC;
      }
    case AF_INET: 
      {
	struct sockaddr_in name;

	u_long  addr = htonl(byte_vector2long (S48_CAR (scheme_name)));
	u_short port = htons(s48_extract_fixnum (S48_CDR (scheme_name)));

	name.sin_family=AF_INET;
	name.sin_addr.s_addr=addr;
	name.sin_port=port;
	if (bind(sockfd,(struct sockaddr *)&name,sizeof(name)) < 0)
	  s48_raise_os_error (errno);

	return S48_UNSPECIFIC;
      }
    default:
	s48_raise_argtype_error (family);	
    }
}

/*-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-*/
s48_value scheme_connect(s48_value sock, s48_value family, s48_value scheme_name)
{
  int sockfd = s48_extract_fixnum (sock);
  switch(s48_extract_fixnum (family))
    {
    case AF_UNIX: 
      {
	struct sockaddr_un name;
	int ret;
	int scheme_length=S48_STRING_LENGTH(scheme_name);
	
	name.sun_family=AF_UNIX;	
	if (scheme_length>=(108-1)) /* save space for \0 */
	  return(-1);
	strncpy(name.sun_path,
		s48_extract_string (scheme_name),
		scheme_length);	/* copy to c string */
	name.sun_path[scheme_length]='\0'; /* add null */
	
	if (connect(sockfd,(struct sockaddr *)&name,sizeof(name)) == 0)
	  return S48_TRUE;
	
	if (errno != EWOULDBLOCK && errno != EINTR && errno != EALREADY
	    && errno != EINPROGRESS && errno != EAGAIN)
	  s48_raise_os_error(errno);
	 
	if (! (s48_add_pending_fd(sockfd, 0)))
	  s48_raise_out_of_memory_error();
	
	if (errno == EINPROGRESS) 
	  return s48_enter_fixnum (0); 
	else return S48_FALSE;
	
      }
    case AF_INET: 
      {
	struct sockaddr_in name;
	
	u_long addr= htonl(byte_vector2long (S48_CAR (scheme_name)));
	u_short port= htons(s48_extract_fixnum (S48_CDR (scheme_name)));

	name.sin_family=AF_INET;
	name.sin_addr.s_addr=addr;
	name.sin_port=port;
	
	if (connect(sockfd,(struct sockaddr *)&name,sizeof(name)) == 0)
	  return S48_TRUE;
	
	if (errno != EWOULDBLOCK && errno != EINTR && errno != EALREADY
	    && errno != EINPROGRESS && errno != EAGAIN)
	  s48_raise_os_error(errno);

	if (! (s48_add_pending_fd(sockfd, 0)))
	  s48_raise_out_of_memory_error();
	
	if (errno == EINPROGRESS) 
	  return s48_enter_fixnum (0); 
	else return S48_FALSE;
	
      }
    default: 
      s48_raise_argtype_error (family);	/* error unknown address family */ 
    } 
}

/*-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-*/
s48_value scheme_accept(s48_value sockfd_tagged, s48_value family)
{
  int  sockfd = s48_extract_fixnum (sockfd_tagged);
  switch(s48_extract_fixnum (family))
    {
    case AF_UNIX: 
      {
	struct sockaddr_un name;
	socklen_t namelen=sizeof(name);
	int newsockfd=accept(sockfd,(struct sockaddr *)&name,&namelen);

	if (newsockfd < 0)
	  {
	    if ((errno != EWOULDBLOCK) && (errno != EINTR) && (errno != EAGAIN))
	      s48_raise_os_error(errno);
	    if (! s48_add_pending_fd(sockfd, 1))// 1 for is_input
	      s48_raise_out_of_memory_error();
	    return S48_FALSE;
	  }

	return(s48_enter_fixnum (newsockfd));
	break;
      }
    case AF_INET: 
      {
	struct sockaddr_in name;
	socklen_t namelen=sizeof(name);
	int newsockfd;
	s48_value result, sock_addr;
	S48_DECLARE_GC_PROTECT(2);
	newsockfd = accept (sockfd,
			    (struct sockaddr *)&name,&namelen);
	
	if (newsockfd < 0)
	  {
	    if ((errno != EWOULDBLOCK) && (errno != EINTR) && (errno != EAGAIN))
	      s48_raise_os_error(errno);
	    if (! s48_add_pending_fd(sockfd, 1))// 1 for is_input
	      s48_raise_out_of_memory_error();
	    return S48_FALSE;
	  }
	fcntl(newsockfd, F_SETFL, O_NONBLOCK);
	S48_GC_PROTECT_2 (result, sock_addr);
	sock_addr = long2byte_vector (ntohl(name.sin_addr.s_addr));
	
	result = s48_cons (sock_addr, s48_enter_fixnum (ntohs(name.sin_port)));

	result = s48_cons (s48_enter_fixnum (newsockfd),
			   result);
	S48_GC_UNPROTECT();
	return result;
	break;
      }
    default:
      s48_raise_argtype_error (family);	    /* error unknown address family */
    }
}

s48_value make_addr (long s_addr, int s_port)
{
  s48_value result, sock_addr;
  S48_DECLARE_GC_PROTECT(2);
  S48_GC_PROTECT_2 (result, sock_addr);
  sock_addr = long2byte_vector (ntohl (s_addr));
  
  result = s48_cons (sock_addr, s48_enter_fixnum (ntohs (s_port)));
  S48_GC_UNPROTECT();
  return result;
}
  
/*-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-*/
s48_value scheme_peer_name(s48_value sock, s48_value family)
{
  int sockfd = s48_extract_fixnum (sock);
  switch(s48_extract_fixnum (family))
    {
    case AF_INET: 
      {
	struct sockaddr_in name;
	socklen_t namelen=sizeof(name);
	int value=getpeername(sockfd,(struct sockaddr *)&name,&namelen);
	
	if (value < 0) s48_raise_os_error (errno);
	
	return (make_addr (name.sin_addr.s_addr, name.sin_port));
	break;
      }
    default:
      s48_raise_argtype_error (family);	/* error unknown address family */
    }
}

/*-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-*/
s48_value scheme_socket_name(s48_value sock, s48_value family)
{
  int sockfd = s48_extract_fixnum (sock);
  switch(s48_extract_fixnum (family))
    {
    case AF_INET: 
      {
	struct sockaddr_in name;
	socklen_t namelen=sizeof(name);
	int value=getsockname(sockfd,(struct sockaddr *)&name,&namelen);
	
	if (value < 0) s48_raise_os_error (errno);
	  
	return(make_addr (name.sin_addr.s_addr,
			  name.sin_port));
	break;
      }
    default:
      s48_raise_argtype_error (family);	/* error unknown address family */
    }
}

/*-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-*/
int scheme_socket_pair(int type, int *s1, int *s2)
{
  int sv[2];
  if( socketpair(PF_UNIX,type,0,sv) ) {
    *s1 = 0; *s2 = 0;
    return errno;
  }
  *s1 = sv[0]; *s2 = sv[1];
  return 0;
}

/*-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-*/
s48_value
recv_substring(s48_value scm_sockfd, s48_value flags, s48_value buf, 
	       s48_value scm_start, s48_value scm_end)
{
  struct sockaddr_in name;
  socklen_t namelen=sizeof(name);
  int sockfd = s48_extract_fixnum (scm_sockfd);
  int start = s48_extract_fixnum (scm_start);
  int end = s48_extract_fixnum (scm_end);
  char* buf_part = s48_extract_string (buf) + start;
  
  int cc=recvfrom(sockfd,
		  buf_part, end-start, 
		  s48_extract_fixnum (flags),
		  (struct sockaddr *)&name, &namelen);
  s48_value result;
  
  if (cc >= 0)
    return (s48_cons (s48_enter_fixnum (cc), 
		      s48_cons (make_addr (name.sin_addr.s_addr,
					   htonl((u_long)ntohs(name.sin_port))),
				S48_NULL)));
	    
  
  if ((errno != EWOULDBLOCK) && (errno != EINTR) && (errno != EAGAIN))
    s48_raise_os_error(errno);
  if (! s48_add_pending_fd(sockfd, 1))// 1 for is_input
    s48_raise_out_of_memory_error();
	return S48_FALSE;
}
      
/*-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-*/
s48_value send_substring(s48_value scm_sockfd,
			 s48_value scm_flags,
			 s48_value buf, 
			 s48_value scm_start, 
			 s48_value scm_end, 
			 s48_value scm_family, 
			 s48_value scheme_name)
{
  int n;
  int s = s48_extract_fixnum (scm_sockfd);
  int flags = s48_extract_fixnum (scm_flags);
  int start = s48_extract_fixnum (scm_start);
  int end = s48_extract_fixnum (scm_end);
  char* buf_part = s48_extract_string (buf) + start;
  
  switch(s48_extract_fixnum (scm_family))
    {
    case 0:			/* only with connected sockets */
      {
	n = send(s, buf_part, end-start, flags);
	break;
      }
    case AF_UNIX:
      {
	struct sockaddr_un name;
	int scheme_length=S48_STRING_LENGTH(scheme_name);
	
	name.sun_family=AF_UNIX;	
	if (scheme_length>=(108-1)) /* save space for \0 */
	  return(-1);
	strncpy(name.sun_path,
		s48_extract_string(scheme_name),
		scheme_length);	/* copy to c string */
	name.sun_path[scheme_length]='\0'; /* add null */
	n = sendto(s, 
		   buf_part, end-start, 
		   flags,
		   (struct sockaddr *)&name, sizeof(name));
	break;
      }
    case AF_INET:
      {
	struct sockaddr_in name;
	u_long  addr = htonl (byte_vector2long (S48_CAR (scheme_name)));
	u_short port = htons(s48_extract_fixnum (S48_CDR (scheme_name)));
	name.sin_family=AF_INET;
	name.sin_addr.s_addr=addr;
	name.sin_port=port;

	n = sendto(s, 
		   buf_part, end-start, 
		   flags,
		   (struct sockaddr *)&name, sizeof(name));
      break;
      }
    default:
      s48_raise_argtype_error (s48_extract_fixnum (scm_family));	
      /* error unknown address family */
    }
  
  if (n >= 0)
    return s48_enter_fixnum (n);

  if ((errno != EWOULDBLOCK) && (errno != EINTR) && (errno != EAGAIN))
    s48_raise_os_error(errno);
  
  if (! s48_add_pending_fd(s, 0))// 0 for is_input
    s48_raise_out_of_memory_error();
  
  return S48_FALSE;
}
  

      
/*-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-*/
int scheme_getsockopt (int s,
		       int level,
		       int optname)
{
  int optval;
  int optlen=sizeof(optval);
  
  if (getsockopt(s,level,optname,(char *)&optval,&optlen) == -1)
    return(-1);
  return(optval);

}

int scheme_getsockopt_linger (int s,
			      int level,
			      int optname,
			      int *out_time)
{
  struct linger optval;
  int optlen=sizeof(optval);
  
  if (getsockopt(s,level,optname,(char *)&optval,&optlen) == -1) {
    out_time = 0;
    return(-1);
    }
  *out_time=optval.l_linger;
  return(optval.l_onoff);
}

int scheme_getsockopt_timeout (int s,
			       int level,
			       int optname,
			       int *out_usec)
{
  struct timeval optval;
  size_t optlen=sizeof(optval);
  
  if (getsockopt(s,level,optname,(char *)&optval,&optlen) == -1) {
    out_usec = 0;
    return(-1);
    }
  *out_usec=optval.tv_usec;
  return(optval.tv_sec);
}
/*-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-*/
int scheme_setsockopt (int s,
		       int level,
		       int optname,
		       int optval)
{
  return(setsockopt(s,level,optname,(char *)&optval,sizeof(optval)));
}

int scheme_setsockopt_linger (int s,
			      int level,
			      int optname,
			      int onoff,
			      int linger)
{
  struct linger optval;

  optval.l_onoff=onoff;
  optval.l_linger=linger;
  
  return(setsockopt(s,level,optname,(char *)&optval,sizeof(optval)));
}

int scheme_setsockopt_timeout (int s,
			       int level,
			       int optname,
			       int sec,
			       int usec)
{
  struct timeval optval;
  optval.tv_sec=sec;
  optval.tv_usec=usec;
  
  return(setsockopt(s,level,optname,(char *)&optval,sizeof(optval)));
}

/*-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-*/
/* Routines for looking up hosts                                           */
/*-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-*/

static s48_value host_info_type_binding = S48_FALSE;

s48_value host_ent2host_info (struct hostent * host)
{
  s48_value host_info = S48_FALSE;
  s48_value list = S48_FALSE;
  long * ptr;
  int i;
  S48_DECLARE_GC_PROTECT (2);
  
  if(host==NULL)
    {  
      return(s48_enter_fixnum (h_errno));
    }
  
  if (host_info_type_binding == S48_FALSE)
    {
      S48_GC_PROTECT_GLOBAL(host_info_type_binding); 
      host_info_type_binding = s48_get_imported_binding ("host-info-type");
    }

  S48_GC_PROTECT_2 (host_info, list);

  host_info = s48_make_record (host_info_type_binding);  
  S48_RECORD_SET (host_info, 0, s48_enter_string (host->h_name)); 
  
  ptr = (long *)host->h_aliases;
  list = S48_NULL;
  i = 0;
  while (*ptr) 
    { 
      list = s48_cons (s48_enter_string (host->h_aliases[i]), list);
      ptr++; 
      i ++;
    }

  S48_RECORD_SET (host_info, 1, list);  

  ptr = (long *)host->h_addr_list;
  list = S48_NULL;
  i = 0;
  while (*ptr)
    {
      list = 
	s48_cons (long2byte_vector (ntohl (*(long *)(host->h_addr_list[i]))), 
		  list);
      ptr++;
      i++;
    }
    
  S48_RECORD_SET (host_info, 2, list);

  S48_GC_UNPROTECT ();
  return host_info;
}

s48_value scheme_host_address2host_info(s48_value addr_port)
{
  struct in_addr name;
  struct hostent *host;

  u_long  addr = htonl(byte_vector2long (S48_CAR (addr_port)));
  name.s_addr = addr;

  host=gethostbyaddr((char *)&name,sizeof(name),AF_INET);
  return (host_ent2host_info (host));
}


s48_value scheme_host_name2host_info(s48_value s_name)
{
  struct in_addr name;
  struct hostent *host;
  char * scheme_name = s48_extract_string (s_name);
  
  if ((name.s_addr=inet_addr(scheme_name)) != -1)
    host=gethostbyaddr((char *)&name,sizeof(name),AF_INET);
  else
    host=gethostbyname(scheme_name);
  
  return (host_ent2host_info (host));
}

/*-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-*/
/* Routines for looking up networks                                        */
/*-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-*/
static s48_value network_info_type_binding = S48_FALSE;

s48_value netent2net_info(struct netent *net)
{
    s48_value network_info = S48_FALSE;
    s48_value list = S48_FALSE;
    long * ptr;
    int i;
    S48_DECLARE_GC_PROTECT (2);
    
    if (net==NULL) return S48_FALSE;
    
    if (network_info_type_binding == S48_FALSE)
	{
	    S48_GC_PROTECT_GLOBAL(network_info_type_binding); 
	    network_info_type_binding = 
		s48_get_imported_binding ("network-info-type");
	}
    S48_GC_PROTECT_2 (network_info, list);
    
    network_info = s48_make_record (network_info_type_binding);  
    S48_RECORD_SET (network_info, 0, s48_enter_string (net->n_name)); 
    
    ptr = (long *)net->n_aliases;
    list = S48_NULL;
    i = 0;
    while (*ptr) 
	{ 
	    list = s48_cons (s48_enter_string (net->n_aliases[i]), list);
	    ptr++; 
	    i++;
	}
    
    S48_RECORD_SET (network_info, 1, list);  
    S48_RECORD_SET (network_info, 2, long2byte_vector (net->n_net)); 

    S48_GC_UNPROTECT ();

    return network_info;    
}

s48_value scheme_net_address2net_info(s48_value net_addr)
{
  struct netent *net;
  // expects host byte order :
  net=getnetbyaddr(byte_vector2long (net_addr),AF_INET); 
  
  return netent2net_info (net);
}

s48_value scheme_net_name2net_info(s48_value scheme_name)
{
  struct netent *net = getnetbyname(s48_extract_string (scheme_name));
  return netent2net_info (net);
}

/*-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-*/
/* Routines for looking up services                                        */
/*-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-*/


static s48_value service_info_type_binding = S48_FALSE;

s48_value servent2service_info(struct servent *serv)
{
    s48_value service_info = S48_FALSE;
    s48_value list = S48_FALSE;
    long * ptr;
    int i;
    S48_DECLARE_GC_PROTECT (2);
    
    if (serv==NULL) return S48_FALSE;
    
    if (service_info_type_binding == S48_FALSE)
	{
	    S48_GC_PROTECT_GLOBAL(service_info_type_binding); 
	    service_info_type_binding = 
		s48_get_imported_binding ("service-info-type");
	}
    S48_GC_PROTECT_2 (service_info, list);
    
    service_info = s48_make_record (service_info_type_binding);  

    S48_RECORD_SET (service_info, 0, s48_enter_string (serv->s_name)); 
    
    ptr = (long *)serv->s_aliases;
    list = S48_NULL;
    i = 0;
    while (*ptr) 
	{ 
	    list = s48_cons (s48_enter_string (serv->s_aliases[i]), list);
	    ptr++; 
	    i++;
	}
    
    S48_RECORD_SET (service_info, 1, list);  
    S48_RECORD_SET (service_info, 2, s48_enter_fixnum (ntohs (serv->s_port)));
    S48_RECORD_SET (service_info, 3, s48_enter_string (serv->s_proto));

    S48_GC_UNPROTECT ();

    return service_info;    
}

s48_value scheme_serv_port2serv_info(s48_value in_port,
				     s48_value in_proto)
{
  struct servent *serv;
  char * proto;
  if (in_proto == S48_FALSE) proto = NULL;
  else proto = s48_extract_string (in_proto);
  
  serv = getservbyport(ntohs(s48_extract_fixnum (in_port)),
		       proto);
  
  return servent2service_info (serv);
}

s48_value scheme_serv_name2serv_info(s48_value in_name,
				     s48_value in_proto)
{
  struct servent *serv;
  char * proto;
  
  if (in_proto == S48_FALSE) proto = NULL;
  else proto = s48_extract_string (in_proto);
  
  serv = getservbyname(s48_extract_string (in_name),
		       proto);
  
  return servent2service_info (serv);
}

/*-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-*/
/* Routines for looking up protocols                                       */
/*-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-*/

static s48_value protocol_info_type_binding = S48_FALSE;

s48_value protoent2protocol_info(struct protoent *proto)
{
    s48_value protocol_info = S48_FALSE;
    s48_value list = S48_FALSE;
    long * ptr;
    int i;
    S48_DECLARE_GC_PROTECT (2);
    
    if (proto==NULL) return S48_FALSE;
    
    if (protocol_info_type_binding == S48_FALSE)
	{
	    S48_GC_PROTECT_GLOBAL(protocol_info_type_binding); 
	    protocol_info_type_binding = 
		s48_get_imported_binding ("protocol-info-type");
	}
    S48_GC_PROTECT_2 (protocol_info, list);
    
    protocol_info = s48_make_record (protocol_info_type_binding);  

    S48_RECORD_SET (protocol_info, 0, s48_enter_string (proto->p_name)); 
    
    ptr = (long *)proto->p_aliases;
    list = S48_NULL;
    i = 0;
    while (*ptr) 
	{ 
	    list = s48_cons (s48_enter_string (proto->p_aliases[i]), list);
	    ptr++; 
	    i++;
	}
    
    S48_RECORD_SET (protocol_info, 1, list);  
    S48_RECORD_SET (protocol_info, 2, s48_enter_fixnum (proto->p_proto));

    S48_GC_UNPROTECT ();

    return protocol_info;    
}

s48_value scheme_proto_num2proto_info(s48_value in_proto)
{
  struct protoent *proto;

  proto=getprotobynumber(s48_extract_fixnum (in_proto));
  
  return protoent2protocol_info (proto);
}

s48_value scheme_proto_name2proto_info(s48_value in_name)
{
  struct protoent *proto=getprotobyname(s48_extract_string (in_name));

  return  protoent2protocol_info (proto);
}


/*-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-*/
/* Low Level Junk                                                          */
/*-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-*/
/* svec is a Scheme vector of C carriers. Scan over the C longs
** in cvec, and initialise the corresponding carriers in svec.
*/
void set_longvec_carriers(s48_value svec, long const * const * cvec)
{
  int svec_len = S48_VECTOR_LENGTH(svec);
  long const * const *cv = cvec;
  s48_value s = S48_VECTOR_REF(svec,0); //JMG hack
  s48_value *sv = &s;

  for(; svec_len > 0; cv++, sv++, svec_len-- ) {
    /* *sv is a (make-string 4) */
    s48_value carrier = *sv;
    (*((u_long *)(S48_ADDRESS_AFTER_HEADER(carrier,unsigned char))))
      =(long)**cv;
  }
}

/*  One arg, a zero-terminated C word vec. Returns length.
**  The terminating null is not counted. Returns #f on NULL.
*/

s48_value veclen(const long *vec)
{
  const long *vptr = vec;
  if( !vptr ) return S48_FALSE;
  while( *vptr ) vptr++;
  return s48_enter_fixnum(vptr - vec);
}