/***************************************************************************
 *                      _   _ ____  _
 *  Project         ___| | | |  _ \| |
 *                 / __| | | | |_) | |
 *                | (__| |_| |  _ <| |___
 *                \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2004, Daniel Stenberg, <daniel@haxx.se>, et al.
 *
 * This software is licensed as described in the file COPYING, which
 * you should have received as part of this distribution. The terms
 * are also available at http://curl.haxx.se/docs/copyright.html.
 *
 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 * copies of the Software, and permit persons to whom the Software is
 * furnished to do so, under the terms of the COPYING file.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 * $Id: ldap.c,v 1.43 2004/10/06 07:50:18 bagder Exp $
 ***************************************************************************/

#include "setup.h"

#ifndef CURL_DISABLE_LDAP
/* -- WIN32 approved -- */
#include <stdio.h>
#include <string.h>
#include <stdarg.h>
#include <stdlib.h>
#include <ctype.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>

#if defined( WIN32 )
# include <windows.h>
# include <malloc.h>
# include <winldap.h>
#endif

#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif

#ifdef HAVE_DLFCN_H
# include <dlfcn.h>
#endif

#include "urldata.h"
#include <curl/curl.h>
#include "sendf.h"
#include "escape.h"
#include "transfer.h"
#include "strequal.h"
#include "strtok.h"
#include "ldap.h"
#include "memory.h"

#define _MPRINTF_REPLACE /* use our functions only */
#include <curl/mprintf.h>

#include "memdebug.h"

/* WLdap32.dll functions are *not* stdcall. Must call these via __cdecl
 * pointers in case libcurl was compiled as fastcall (-Gr).
 */
#if !defined( WIN32 ) && !defined( __cdecl )
#define __cdecl
#endif

#ifndef LDAP_SIZELIMIT_EXCEEDED
#define LDAP_SIZELIMIT_EXCEEDED 4
#endif

#define DLOPEN_MODE   RTLD_LAZY  /*! assume all dlopen() implementations have
								   this */

#if defined( RTLD_LAZY_GLOBAL )    /* It turns out some systems use this: */
# undef  DLOPEN_MODE
# define DLOPEN_MODE  RTLD_LAZY_GLOBAL
#elif defined( RTLD_GLOBAL )
# undef  DLOPEN_MODE
# define DLOPEN_MODE  ( RTLD_LAZY | RTLD_GLOBAL )
#endif

#define DYNA_GET_FUNCTION( type, fnc ) do {	\
		( fnc ) = (type)DynaGetFunction( # fnc ); \
		if ( ( fnc ) == NULL ) { \
			return CURLE_FUNCTION_NOT_FOUND;} \
} while ( 0 )

/*! CygWin etc. configure could set these, but we don't want it.
 * Must use WLdap32.dll code.
 */
#if defined( WIN32 )
#undef HAVE_DLOPEN
#undef HAVE_LIBDL
#endif

typedef void * ( *dynafunc )( void *input );

/***********************************************************************
 */
static void *libldap = NULL;
#ifndef WIN32
static void *liblber = NULL;
#endif

static int DynaOpen( const char **mod_name ) {
#if defined( HAVE_DLOPEN ) || defined( HAVE_LIBDL )
	if ( libldap == NULL ) {
		/*
		 * libldap.so should be able to resolve its dependency on
		 * liblber.so automatically, but since it does not we will
		 * handle it here by opening liblber.so as global.
		 */
		*mod_name = "liblber.so";
		liblber = dlopen( *mod_name, DLOPEN_MODE );

		/* Assume loading libldap.so will fail if loading of liblber.so failed
		 */
		if ( liblber ) {
			*mod_name = "libldap.so";
			libldap = dlopen( *mod_name, RTLD_LAZY );
		}
	}
	return ( libldap != NULL && liblber != NULL );

#elif defined( WIN32 )
	*mod_name = "wldap32.dll";
	if ( !libldap ) {
		libldap = (void*)LoadLibrary( *mod_name );
	}
	return ( libldap != NULL );

#else
	return ( 0 );
#endif
}

static void DynaClose( void ) {
#if defined( HAVE_DLOPEN ) || defined( HAVE_LIBDL )
	if ( libldap ) {
		dlclose( libldap );
		libldap = NULL;
	}
	if ( liblber ) {
		dlclose( liblber );
		liblber = NULL;
	}
#elif defined( WIN32 )
	if ( libldap ) {
		FreeLibrary( (HMODULE)libldap );
		libldap = NULL;
	}
#endif
}

static dynafunc DynaGetFunction( const char *name ) {
	dynafunc func = (dynafunc)NULL;

#if defined( HAVE_DLOPEN ) || defined( HAVE_LIBDL )
	if ( libldap ) {
		/* This typecast magic below was brought by Joe Halpin. In ISO C, you
		 * cannot typecast a data pointer to a function pointer, but that's
		 * exactly what we need to do here to avoid compiler warnings on picky
		 * compilers! */
		*( void** )( &func ) = dlsym( libldap, name );
	}
#elif defined( WIN32 )
	if ( libldap ) {
		func = (dynafunc)GetProcAddress( (HINSTANCE)libldap, name );
	}
#endif
	return func;
}

/***********************************************************************
 */
typedef struct ldap_url_desc {
	struct ldap_url_desc *lud_next;
	char   *lud_scheme;
	char   *lud_host;
	int lud_port;
	char   *lud_dn;
	char  **lud_attrs;
	int lud_scope;
	char   *lud_filter;
	char  **lud_exts;
	int lud_crit_exts;
} LDAPURLDesc;

#ifdef WIN32
static int  _ldap_url_parse( const struct connectdata *conn,
							 LDAPURLDesc **ludp );
static void _ldap_free_urldesc( LDAPURLDesc *ludp );

static void ( *ldap_free_urldesc )( LDAPURLDesc * ) = _ldap_free_urldesc;
#endif

#ifdef DEBUG_LDAP
  #define LDAP_TRACE( x )   do { \
		_ldap_trace( "%u: ", __LINE__ ); \
		_ldap_trace x; \
} while ( 0 )

static void _ldap_trace( const char *fmt, ... );
#else
  #define LDAP_TRACE( x )   ( (void)0 )
#endif


CURLcode Curl_ldap( struct connectdata *conn ) {
	CURLcode status = CURLE_OK;
	int rc = 0;
#ifndef WIN32
	int ( *ldap_url_parse )( char *, LDAPURLDesc ** );
	void ( *ldap_free_urldesc )( void * );
#endif
	void  *( __cdecl * ldap_init )( char *, int );
	int ( __cdecl * ldap_simple_bind_s )( void *, char *, char * );
	int ( __cdecl * ldap_unbind_s )( void * );
	int ( __cdecl * ldap_search_s )( void *, char *, int, char *, char **,
									 int, void ** );
	void  *( __cdecl * ldap_first_entry )( void *, void * );
	void  *( __cdecl * ldap_next_entry )( void *, void * );
	char  *( __cdecl * ldap_err2string )(int);
	char  *( __cdecl * ldap_get_dn )( void *, void * );
	char  *( __cdecl * ldap_first_attribute )( void *, void *, void ** );
	char  *( __cdecl * ldap_next_attribute )( void *, void *, void * );
	char **( __cdecl * ldap_get_values )( void *, void *, const char * );
	void ( __cdecl * ldap_value_free )( char ** );
	void ( __cdecl * ldap_memfree )( void * );
	void ( __cdecl * ber_free )( void *, int );

	void *server;
	LDAPURLDesc *ludp = NULL;
	const char *mod_name;
	void *result;
	void *entryIterator;   /*! type should be 'LDAPMessage *' */
	int num = 0;
	struct SessionHandle *data = conn->data;

	infof( data, "LDAP local: %s\n", data->change.url );

	if ( !DynaOpen( &mod_name ) ) {
		failf( data, "The %s LDAP library/libraries couldn't be opened", mod_name );
		return CURLE_LIBRARY_NOT_FOUND;
	}

	/* The types are needed because ANSI C distinguishes between
	 * pointer-to-object (data) and pointer-to-function.
	 */
	DYNA_GET_FUNCTION( void *( * )( char *, int ), ldap_init );
	DYNA_GET_FUNCTION( int( * ) ( void *, char *, char * ), ldap_simple_bind_s );
	DYNA_GET_FUNCTION( int( * ) ( void * ), ldap_unbind_s );
#ifndef WIN32
	DYNA_GET_FUNCTION( int( * ) ( char *, LDAPURLDesc * * ), ldap_url_parse );
	DYNA_GET_FUNCTION( void( * ) ( void * ), ldap_free_urldesc );
#endif
	DYNA_GET_FUNCTION( int( * ) ( void *, char *, int, char *, char **, int,
								  void ** ), ldap_search_s );
	DYNA_GET_FUNCTION( void *( * )( void *, void * ), ldap_first_entry );
	DYNA_GET_FUNCTION( void *( * )( void *, void * ), ldap_next_entry );
	DYNA_GET_FUNCTION( char *( * )( int ), ldap_err2string );
	DYNA_GET_FUNCTION( char *( * )( void *, void * ), ldap_get_dn );
	DYNA_GET_FUNCTION( char *( * )( void *, void *, void ** ), ldap_first_attribute );
	DYNA_GET_FUNCTION( char *( * )( void *, void *, void * ), ldap_next_attribute );
	DYNA_GET_FUNCTION( char **( * )( void *, void *, const char * ), ldap_get_values );
	DYNA_GET_FUNCTION( void( * ) ( char ** ), ldap_value_free );
	DYNA_GET_FUNCTION( void( * ) ( void * ), ldap_memfree );
	DYNA_GET_FUNCTION( void( * ) ( void *, int ), ber_free );

	server = ( *ldap_init )( conn->host.name, (int)conn->port );
	if ( server == NULL ) {
		failf( data, "LDAP local: Cannot connect to %s:%d",
			   conn->host.name, conn->port );
		status = CURLE_COULDNT_CONNECT;
		goto quit;
	}

	rc = ( *ldap_simple_bind_s )( server,
								  conn->bits.user_passwd ? conn->user : NULL,
								  conn->bits.user_passwd ? conn->passwd : NULL );
	if ( rc != 0 ) {
		failf( data, "LDAP local: %s", ( *ldap_err2string )( rc ) );
		status = CURLE_LDAP_CANNOT_BIND;
		goto quit;
	}

#ifdef WIN32
	rc = _ldap_url_parse( conn, &ludp );
#else
	rc = ( *ldap_url_parse )( data->change.url, &ludp );
#endif

	if ( rc != 0 ) {
		failf( data, "LDAP local: %s", ( *ldap_err2string )( rc ) );
		status = CURLE_LDAP_INVALID_URL;
		goto quit;
	}

	rc = ( *ldap_search_s )( server, ludp->lud_dn, ludp->lud_scope,
							 ludp->lud_filter, ludp->lud_attrs, 0, &result );

	if ( rc != 0 && rc != LDAP_SIZELIMIT_EXCEEDED ) {
		failf( data, "LDAP remote: %s", ( *ldap_err2string )( rc ) );
		status = CURLE_LDAP_SEARCH_FAILED;
		goto quit;
	}

	for ( num = 0, entryIterator = ( *ldap_first_entry )( server, result );
		  entryIterator;
		  entryIterator = ( *ldap_next_entry )( server, entryIterator ), num++ )
	{
		void  *ber = NULL;  /*! is really 'BerElement **' */
		void  *attribute;   /*! suspicious that this isn't 'const' */
		char  *dn = ( *ldap_get_dn )( server, entryIterator );
		int i;

		Curl_client_write( data, CLIENTWRITE_BODY, (char *)"DN: ", 4 );
		Curl_client_write( data, CLIENTWRITE_BODY, (char *)dn, 0 );
		Curl_client_write( data, CLIENTWRITE_BODY, (char *)"\n", 1 );

		for ( attribute = ( *ldap_first_attribute )( server, entryIterator, &ber );
			  attribute;
			  attribute = ( *ldap_next_attribute )( server, entryIterator, ber ) )
		{
			char **vals = ( *ldap_get_values )( server, entryIterator, attribute );

			if ( vals != NULL ) {
				for ( i = 0; ( vals[i] != NULL ); i++ )
				{
					Curl_client_write( data, CLIENTWRITE_BODY, (char *)"\t", 1 );
					Curl_client_write( data, CLIENTWRITE_BODY, (char*) attribute, 0 );
					Curl_client_write( data, CLIENTWRITE_BODY, (char *)": ", 2 );
					Curl_client_write( data, CLIENTWRITE_BODY, vals[i], 0 );
					Curl_client_write( data, CLIENTWRITE_BODY, (char *)"\n", 0 );
				}

				/* Free memory used to store values */
				( *ldap_value_free )( vals );
			}
			Curl_client_write( data, CLIENTWRITE_BODY, (char *)"\n", 1 );

			( *ldap_memfree )( attribute );
		}
		( *ldap_memfree )( dn );
		if ( ber ) {
			( *ber_free )( ber, 0 );
		}
	}

quit:
	LDAP_TRACE( ( "Received %d entries\n", num ) );
	if ( rc == LDAP_SIZELIMIT_EXCEEDED ) {
		infof( data, "There are more than %d entries\n", num );
	}
	if ( ludp ) {
		( *ldap_free_urldesc )( ludp );
	}
	if ( server ) {
		( *ldap_unbind_s )( server );
	}

	DynaClose();

	/* no data to transfer */
	Curl_Transfer( conn, -1, -1, FALSE, NULL, -1, NULL );

	return status;
}

#ifdef DEBUG_LDAP
static void _ldap_trace( const char *fmt, ... ) {
	static int do_trace = -1;
	va_list args;

	if ( do_trace == -1 ) {
		const char *env = getenv( "CURL_TRACE" );
		do_trace = ( env && atoi( env ) > 0 );
	}
	if ( !do_trace ) {
		return;
	}

	va_start( args, fmt );
	vfprintf( stderr, fmt, args );
	va_end( args );
}
#endif

#ifdef WIN32
/*
 * Return scope-value for a scope-string.
 */
static int str2scope( const char *p ) {
	if ( !stricmp( p, "one" ) ) {
		return LDAP_SCOPE_ONELEVEL;
	}
	if ( !stricmp( p, "onetree" ) ) {
		return LDAP_SCOPE_ONELEVEL;
	}
	if ( !stricmp( p, "base" ) ) {
		return LDAP_SCOPE_BASE;
	}
	if ( !stricmp( p, "sub" ) ) {
		return LDAP_SCOPE_SUBTREE;
	}
	if ( !stricmp( p, "subtree" ) ) {
		return LDAP_SCOPE_SUBTREE;
	}
	return ( -1 );
}

/*
 * Split 'str' into strings separated by commas.
 * Note: res[] points into 'str'.
 */
static char **split_str( char *str ) {
	char **res, *lasts, *s;
	int i;

	for ( i = 2, s = strchr( str,',' ); s; i++ )
		s = strchr( ++s,',' );

	res = calloc( i, sizeof( char* ) );
	if ( !res ) {
		return NULL;
	}

	for ( i = 0, s = strtok_r( str, ",", &lasts ); s;
		  s = strtok_r( NULL, ",", &lasts ), i++ )
		res[i] = s;
	return res;
}

/*
 * Unescape the LDAP-URL components
 */
static bool unescape_elements( LDAPURLDesc *ludp ) {
	int i;

	if ( ludp->lud_filter ) {
		ludp->lud_filter = curl_unescape( ludp->lud_filter, 0 );
		if ( !ludp->lud_filter ) {
			return ( FALSE );
		}
	}

	for ( i = 0; ludp->lud_attrs && ludp->lud_attrs[i]; i++ ) {
		ludp->lud_attrs[i] = curl_unescape( ludp->lud_attrs[i], 0 );
		if ( !ludp->lud_attrs[i] ) {
			return ( FALSE );
		}
	}

	for ( i = 0; ludp->lud_exts && ludp->lud_exts[i]; i++ ) {
		ludp->lud_exts[i] = curl_unescape( ludp->lud_exts[i], 0 );
		if ( !ludp->lud_exts[i] ) {
			return ( FALSE );
		}
	}

	if ( ludp->lud_dn ) {
		char *dn = ludp->lud_dn;
		char *new_dn = curl_unescape( dn, 0 );

		free( dn );
		if ( !new_dn ) {
			return ( FALSE );
		}
		ludp->lud_dn = new_dn;
	}
	return ( TRUE );
}

/*
 * Break apart the pieces of an LDAP URL.
 * Syntax:
 *   ldap://<hostname>:<port>/<base_dn>?<attributes>?<scope>?<filter>?<ext>
 *
 * <hostname> already known from 'conn->host.name'.
 * <port>     already known from 'conn->remote_port'.
 * extract the rest from 'conn->path+1'. All fields are optional. e.g.
 *   ldap://<hostname>:<port>/?<attributes>?<scope>?<filter> yields ludp->lud_dn = "".
 *
 * Ref. http://developer.netscape.com/docs/manuals/dirsdk/csdk30/url.htm#2831915
 */
static int _ldap_url_parse2( const struct connectdata *conn, LDAPURLDesc *ludp ) {
	char *p, *q;
	int i;

	if ( !conn->path || conn->path[0] != '/' ||
		 !checkprefix( conn->protostr, conn->data->change.url ) ) {
		return LDAP_INVALID_SYNTAX;
	}

	ludp->lud_scope = LDAP_SCOPE_BASE;
	ludp->lud_port  = conn->remote_port;
	ludp->lud_host  = conn->host.name;

	/* parse DN (Distinguished Name).
	 */
	ludp->lud_dn = strdup( conn->path + 1 );
	if ( !ludp->lud_dn ) {
		return LDAP_NO_MEMORY;
	}

	p = strchr( ludp->lud_dn, '?' );
	LDAP_TRACE( ( "DN '%.*s'\n", p ? (size_t)( p - ludp->lud_dn ) : strlen( ludp->lud_dn ),
				  ludp->lud_dn ) );

	if ( !p ) {
		goto success;
	}

	*p++ = '\0';

	/* parse attributes. skip "??".
	 */
	q = strchr( p, '?' );
	if ( q ) {
		*q++ = '\0';
	}

	if ( *p && *p != '?' ) {
		ludp->lud_attrs = split_str( p );
		if ( !ludp->lud_attrs ) {
			return LDAP_NO_MEMORY;
		}

		for ( i = 0; ludp->lud_attrs[i]; i++ )
			LDAP_TRACE( ( "attr[%d] '%s'\n", i, ludp->lud_attrs[i] ) );
	}

	p = q;
	if ( !p ) {
		goto success;
	}

	/* parse scope. skip "??"
	 */
	q = strchr( p, '?' );
	if ( q ) {
		*q++ = '\0';
	}

	if ( *p && *p != '?' ) {
		ludp->lud_scope = str2scope( p );
		if ( ludp->lud_scope == -1 ) {
			return LDAP_INVALID_SYNTAX;
		}
		LDAP_TRACE( ( "scope %d\n", ludp->lud_scope ) );
	}

	p = q;
	if ( !p ) {
		goto success;
	}

	/* parse filter
	 */
	q = strchr( p, '?' );
	if ( q ) {
		*q++ = '\0';
	}
	if ( !*p ) {
		return LDAP_INVALID_SYNTAX;
	}

	ludp->lud_filter = p;
	LDAP_TRACE( ( "filter '%s'\n", ludp->lud_filter ) );

	p = q;
	if ( !p ) {
		goto success;
	}

	/* parse extensions
	 */
	ludp->lud_exts = split_str( p );
	if ( !ludp->lud_exts ) {
		return LDAP_NO_MEMORY;
	}

	for ( i = 0; ludp->lud_exts[i]; i++ )
		LDAP_TRACE( ( "exts[%d] '%s'\n", i, ludp->lud_exts[i] ) );

success:
	if ( !unescape_elements( ludp ) ) {
		return LDAP_NO_MEMORY;
	}
	return LDAP_SUCCESS;
}

static int _ldap_url_parse( const struct connectdata *conn,
							LDAPURLDesc **ludpp ) {
	LDAPURLDesc *ludp = calloc( sizeof( *ludp ), 1 );
	int rc;

	*ludpp = NULL;
	if ( !ludp ) {
		return LDAP_NO_MEMORY;
	}

	rc = _ldap_url_parse2( conn, ludp );
	if ( rc != LDAP_SUCCESS ) {
		_ldap_free_urldesc( ludp );
		ludp = NULL;
	}
	*ludpp = ludp;
	return ( rc );
}

static void _ldap_free_urldesc( LDAPURLDesc *ludp ) {
	int i;

	if ( !ludp ) {
		return;
	}

	if ( ludp->lud_dn ) {
		free( ludp->lud_dn );
	}

	if ( ludp->lud_filter ) {
		free( ludp->lud_filter );
	}

	if ( ludp->lud_attrs ) {
		for ( i = 0; ludp->lud_attrs[i]; i++ )
			free( ludp->lud_attrs[i] );
		free( ludp->lud_attrs );
	}

	if ( ludp->lud_exts ) {
		for ( i = 0; ludp->lud_exts[i]; i++ )
			free( ludp->lud_exts[i] );
		free( ludp->lud_exts );
	}
	free( ludp );
}
#endif  /* WIN32 */
#endif  /* CURL_DISABLE_LDAP */