libs-base/Source/NSHost.m

/* Implementation of host class
   Copyright (C) 1996, 1997 Free Software Foundation, Inc.
   
   Written by: Luke Howard <lukeh@xedoc.com.au> 
   Date: 1996
   
   This file is part of the GNUstep Base Library.

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public
   License as published by the Free Software Foundation; either
   version 2 of the License, or (at your option) any later version.
   
   This library 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
   Library General Public License for more details.
   
   You should have received a copy of the GNU Library General Public
   License along with this library; if not, write to the Free
   Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   */ 

#include <config.h>
#include <base/preface.h>
#include <Foundation/NSLock.h>
#include <Foundation/NSHost.h>
#include <Foundation/NSArray.h>
#include <Foundation/NSDictionary.h>
#include <Foundation/NSString.h>
#include <Foundation/NSCoder.h>
#include <netdb.h>
/* #include <libc.h> */

#ifdef WIN32
#include <Windows32/Sockets.h>
#else
#include <unistd.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <netinet/in.h>
#endif /* WIN32 */

static NSLock *_hostCacheLock = nil;
static BOOL _hostCacheEnabled = NO;
static NSMutableDictionary *_hostCache = nil;

@interface NSHost (Private)
+ (NSHost *)_hostWithHostEntry:(struct hostent *)entry;
+ (NSHost *)_hostWithHostEntry:(struct hostent *)entry name:name;
- _initWithHostEntry:(struct hostent *)entry name:name;
@end

@implementation NSHost (Private)

+ (NSHost *)_hostWithHostEntry:(struct hostent *)entry
{
  if (!entry)
    return nil;
		
  return [[self class] _hostWithHostEntry:entry  
		       name:[NSString stringWithCString:entry->h_name]];
}

+ (NSHost *)_hostWithHostEntry:(struct hostent *)entry name:name
{
  NSHost *res = nil;
		
  [_hostCacheLock lock];
  if (_hostCacheEnabled == YES)
    {
      res = [_hostCache objectForKey:name];
    }
  [_hostCacheLock unlock];
	
  return (res != nil) ? res : [[[[self class] alloc]  
				 _initWithHostEntry:entry name:name] autorelease];
}

- _initWithHostEntry:(struct hostent *)entry name:name
{
  int i;
  char *ptr;
  struct in_addr in;
  NSString *h_name;
	
  [super init];
	
  if (entry == (struct hostent *)NULL)
    {
      return nil;
    }
		
  names = [[NSMutableArray array] retain];
  addresses = [[NSMutableArray array] retain];
	
  [names addObject:name];
  h_name = [NSString stringWithCString:entry->h_name];
	
  if (![h_name isEqual:name])
    {
      [names addObject:h_name];
    }
	
  for (i = 0, ptr = entry->h_aliases[0]; ptr != NULL; i++,  
	 ptr = entry->h_aliases[i])
    {
      [names addObject:[NSString stringWithCString:ptr]];
    }

  for (i = 0, ptr = entry->h_addr_list[0]; ptr != NULL; i++,  
	 ptr = entry->h_addr_list[i])
    {
      memcpy((void *)&in.s_addr, (const void *)ptr,  
	      entry->h_length);
      [addresses addObject:[NSString  
			     stringWithCString:(char*)inet_ntoa(in)]];
    }

  [_hostCacheLock lock];
  if (_hostCacheEnabled == YES)
    {
      [_hostCache setObject:self forKey:name];
    }
  [_hostCacheLock unlock];
	
  return self;
}

@end

@implementation NSHost

- init
{
  return nil;
}

+ (void)initialize
{
  _hostCacheLock = [[NSConditionLock alloc] init];
  _hostCache = [NSMutableDictionary new];
}

+ (NSHost *)currentHost
{
  char name[MAXHOSTNAMELEN];
  int res;
  struct hostent *h;
	
  res = gethostname(name, sizeof(name));
  if (res < 0)
    {
      return nil;
    }
		
  h = gethostbyname(name);
	
  return [self _hostWithHostEntry:h name:[NSString  
					   stringWithCString:name]];
}

+ (NSHost *)hostWithName:(NSString *)name
{
  struct hostent *h;
	
  h = gethostbyname((char *)[name cString]);
	
  return [self _hostWithHostEntry:h name:name];
	
}

+ (NSHost *)hostWithAddress:(NSString *)address
{
  struct hostent *h;
  struct in_addr hostaddr;
	
  hostaddr.s_addr = inet_addr((char *)[address cString]);
  if (hostaddr.s_addr == -1)
    {
      return nil;
    }
		
  h = gethostbyaddr((char *)&hostaddr, sizeof(hostaddr), AF_INET);
  return [self _hostWithHostEntry:h];
}

+ (void)setHostCacheEnabled:(BOOL)flag
{
  [_hostCacheLock lock];
  _hostCacheEnabled = flag;
  [_hostCacheLock unlock];
}

+ (BOOL)isHostCacheEnabled;
{
  BOOL res;
	
  [_hostCacheLock lock];
  res = _hostCacheEnabled;
  [_hostCacheLock unlock];
	
  return res;
}

+ (void)flushHostCache
{
  [_hostCacheLock lock];
  [_hostCache removeAllObjects];
  [_hostCacheLock unlock];
}

/* Methods for encoding/decoding */
- (Class) classForPortCoder
{
  return [self class];
}
- replacementObjectForPortCoder:(NSPortCoder*)aCoder
{
    return self;
}
- (void) encodeWithCoder: (NSCoder*)aCoder
{
    [super encodeWithCoder: aCoder];
    [aCoder encodeObject: [self address]];
}

#if 1
/*	GNUstep specific method for more efficient decoding. */
+ (id) newWithCoder: (NSCoder*)aCoder
{
    NSString	*address = [aCoder decodeObject];
    return [NSHost hostWithAddress: address];
}
#else
/*	OpenStep methods for decoding (not used) */
- (id) awakeAfterUsingCoder: (NSCoder*)aCoder
{
    return [NSHost hostWithAddress: [addresses objectAtIndex: 0]];
}

- (id) initWithCoder: (NSCoder*)aCoder
{
    NSString	*address;

    [super initWithCoder: aCoder];
    address = [aCoder decodeObject];
    addresses = [NSArray arrayWithObject: address];
    return self;
}
#endif

/*
 *	The OpenStep spec says that [-hash] must be the same for any two
 *	objects that [-isEqual:] returns YES for.  We have a problem in
 *	that [-isEqualToHost:] is specified to return YES if any name or
 *	address part of two hosts is the same.  That means we can't
 *	reasonably calculate a hash since two hosts with radically
 *	different ivar contents may be 'equal'.  The best I can think of
 *	is for all hosts to hash to the same value - which makes it very
 *	inefficient to store them in a set, dictionary, map or hash table.
 */
- (unsigned) hash
{
  return 1;
}

- (BOOL) isEqual: (id)other
{
  if (other == self)
    return YES;
  if ([other isKindOfClass: [NSHost class]])
    return [self isEqualToHost: (NSHost*)other];
  return NO;
}

- (BOOL)isEqualToHost:(NSHost *)aHost
{
  NSArray*	a;
  int		i;

  if (aHost == self)
    return YES;

  a = [aHost addresses];
  for (i = 0; i < [a count]; i++)
    if ([addresses containsObject:[a objectAtIndex:i]])
      return YES;

  a = [aHost names];
  for (i = 0; i < [a count]; i++)
    if ([addresses containsObject:[a objectAtIndex:i]])
      return YES;

  return NO;
}

- (NSString *)name
{
  return [names objectAtIndex:0];
}

- (NSArray *)names
{
  return names;
}

- (NSString *)address
{
  return [addresses objectAtIndex:0];
}

- (NSArray *)addresses
{
  return addresses;
}

- (NSString *)description
{
  return [NSString stringWithFormat:@"Host %@ (%@ %@)", [self  
							  name],
		   [[self names] description], [[self addresses]  
						 description]];
}

- (void)dealloc
{
  [names autorelease];
  [addresses autorelease];
  [super dealloc];
}

@end