/***************************************************************************
 *                                  _   _ ____  _
 *  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: hostares.c,v 1.9 2004/10/06 07:50:18 bagder Exp $
 ***************************************************************************/

#include "setup.h"

#include <string.h>
#include <errno.h>

#define _REENTRANT

#if defined( WIN32 ) && !defined( __GNUC__ ) || defined( __MINGW32__ )
#include <malloc.h>
#else
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#ifdef HAVE_NETDB_H
#include <netdb.h>
#endif
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>     /* required for free() prototypes */
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>     /* for the close() proto */
#endif
#ifdef  VMS
#include <in.h>
#include <inet.h>
#include <stdlib.h>
#endif
#endif

#ifdef HAVE_SETJMP_H
#include <setjmp.h>
#endif

#ifdef WIN32
#include <process.h>
#endif

#if ( defined( NETWARE ) && defined( __NOVELL_LIBC__ ) )
#undef in_addr_t
#define in_addr_t unsigned long
#endif

#include "urldata.h"
#include "sendf.h"
#include "hostip.h"
#include "hash.h"
#include "share.h"
#include "strerror.h"
#include "url.h"

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

#if defined( HAVE_INET_NTOA_R ) && !defined( HAVE_INET_NTOA_R_DECL )
#include "inet_ntoa_r.h"
#endif

#include "memory.h"

/* The last #include file should be: */
#include "memdebug.h"

/***********************************************************************
 * Only for ares-enabled builds
 **********************************************************************/

#ifdef CURLRES_ARES

/*
 * Curl_fdset() is called when someone from the outside world (using
 * curl_multi_fdset()) wants to get our fd_set setup and we're talking with
 * ares. The caller must make sure that this function is only called when we
 * have a working ares channel.
 *
 * Returns: CURLE_OK always!
 */

CURLcode Curl_fdset( struct connectdata *conn,
					 fd_set *read_fd_set,
					 fd_set *write_fd_set,
					 int *max_fdp ) {
	int max = ares_fds( conn->data->state.areschannel,
						read_fd_set, write_fd_set );
	*max_fdp = max;

	return CURLE_OK;
}

/*
 * Curl_is_resolved() is called repeatedly to check if a previous name resolve
 * request has completed. It should also make sure to time-out if the
 * operation seems to take too long.
 *
 * Returns normal CURLcode errors.
 */
CURLcode Curl_is_resolved( struct connectdata *conn,
						   struct Curl_dns_entry **dns ) {
	fd_set read_fds, write_fds;
	struct timeval tv = {0,0};
	struct SessionHandle *data = conn->data;
	int nfds;

	FD_ZERO( &read_fds );
	FD_ZERO( &write_fds );

	nfds = ares_fds( data->state.areschannel, &read_fds, &write_fds );

	(void)select( nfds, &read_fds, &write_fds, NULL,
				  (struct timeval *)&tv );

	/* Call ares_process() unconditonally here, even if we simply timed out
	   above, as otherwise the ares name resolve won't timeout! */
	ares_process( data->state.areschannel, &read_fds, &write_fds );

	*dns = NULL;

	if ( conn->async.done ) {
		/* we're done, kill the ares handle */
		if ( !conn->async.dns ) {
			failf( data, "Could not resolve host: %s (%s)", conn->host.dispname,
				   ares_strerror( conn->async.status ) );
			return CURLE_COULDNT_RESOLVE_HOST;
		}
		*dns = conn->async.dns;
	}

	return CURLE_OK;
}

/*
 * Curl_wait_for_resolv() waits for a resolve to finish. This function should
 * be avoided since using this risk getting the multi interface to "hang".
 *
 * If 'entry' is non-NULL, make it point to the resolved dns entry
 *
 * Returns CURLE_COULDNT_RESOLVE_HOST if the host was not resolved, and
 * CURLE_OPERATION_TIMEDOUT if a time-out occurred.
 */
CURLcode Curl_wait_for_resolv( struct connectdata *conn,
							   struct Curl_dns_entry **entry ) {
	CURLcode rc = CURLE_OK;
	struct SessionHandle *data = conn->data;
	long timeout = CURL_TIMEOUT_RESOLVE; /* default name resolve timeout */

	/* now, see if there's a connect timeout or a regular timeout to
	   use instead of the default one */
	if ( conn->data->set.connecttimeout ) {
		timeout = conn->data->set.connecttimeout;
	} else if ( conn->data->set.timeout )   {
		timeout = conn->data->set.timeout;
	}

	/* We convert the number of seconds into number of milliseconds here: */
	if ( timeout < 2147483 ) {
		/* maximum amount of seconds that can be multiplied with 1000 and
		   still fit within 31 bits */
		timeout *= 1000;
	} else {
		timeout = 0x7fffffff; /* ridiculous amount of time anyway */

	}
	/* Wait for the name resolve query to complete. */
	while ( 1 ) {
		int nfds = 0;
		fd_set read_fds, write_fds;
		struct timeval *tvp, tv, store;
		int count;
		struct timeval now = Curl_tvnow();
		long timediff;

		store.tv_sec = (int)timeout / 1000;
		store.tv_usec = ( timeout % 1000 ) * 1000;

		FD_ZERO( &read_fds );
		FD_ZERO( &write_fds );
		nfds = ares_fds( data->state.areschannel, &read_fds, &write_fds );
		if ( nfds == 0 ) {
			/* no file descriptors means we're done waiting */
			break;
		}
		tvp = ares_timeout( data->state.areschannel, &store, &tv );
		count = select( nfds, &read_fds, &write_fds, NULL, tvp );
		if ( count < 0 && errno != EINVAL ) {
			break;
		}

		ares_process( data->state.areschannel, &read_fds, &write_fds );

		timediff = Curl_tvdiff( Curl_tvnow(), now ); /* spent time */
		timeout -= timediff ? timediff : 1; /* always deduct at least 1 */
		if ( timeout < 0 ) {
			/* our timeout, so we cancel the ares operation */
			ares_cancel( data->state.areschannel );
			break;
		}
	}

	/* Operation complete, if the lookup was successful we now have the entry
	   in the cache. */

	if ( entry ) {
		*entry = conn->async.dns;
	}

	if ( !conn->async.dns ) {
		/* a name was not resolved */
		if ( ( timeout < 0 ) || ( conn->async.status == ARES_ETIMEOUT ) ) {
			failf( data, "Resolving host timed out: %s", conn->host.dispname );
			rc = CURLE_OPERATION_TIMEDOUT;
		} else if ( conn->async.done )      {
			failf( data, "Could not resolve host: %s (%s)", conn->host.dispname,
				   ares_strerror( conn->async.status ) );
			rc = CURLE_COULDNT_RESOLVE_HOST;
		} else {
			rc = CURLE_OPERATION_TIMEDOUT;
		}

		/* close the connection, since we can't return failure here without
		   cleaning up this connection properly */
		Curl_disconnect( conn );
	}

	return rc;
}

/*
 * Curl_getaddrinfo() - when using ares
 *
 * Returns name information about the given hostname and port number. If
 * successful, the 'hostent' is returned and the forth argument will point to
 * memory we need to free after use. That memory *MUST* be freed with
 * Curl_freeaddrinfo(), nothing else.
 */
Curl_addrinfo *Curl_getaddrinfo( struct connectdata *conn,
								 char *hostname,
								 int port,
								 int *waitp ) {
	char *bufp;
	struct SessionHandle *data = conn->data;
	in_addr_t in = inet_addr( hostname );

	*waitp = FALSE;

	if ( in != CURL_INADDR_NONE ) {
		/* This is a dotted IP address 123.123.123.123-style */
		return Curl_ip2addr( in, hostname, port );
	}

	bufp = strdup( hostname );

	if ( bufp ) {
		Curl_safefree( conn->async.hostname );
		conn->async.hostname = bufp;
		conn->async.port = port;
		conn->async.done = FALSE; /* not done */
		conn->async.status = 0; /* clear */
		conn->async.dns = NULL; /* clear */

		/* areschannel is already setup in the Curl_open() function */
		ares_gethostbyname( data->state.areschannel, hostname, PF_INET,
							Curl_addrinfo4_callback, conn );

		*waitp = TRUE; /* please wait for the response */
	}
	return NULL; /* no struct yet */
}

#endif /* CURLRES_ARES */
