
/* #line 1 "./ragel/tnet_dns_resolvconf.rl" */
/*
* Copyright (C) 2009 Mamadou Diop.
*
* Contact: Mamadou Diop <diopmamadou(at)doubango.org>
*	
* This file is part of Open Source Doubango Framework.
*
* DOUBANGO is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*	
* DOUBANGO 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 General Public License for more details.
*	
* You should have received a copy of the GNU General Public License
* along with DOUBANGO.
*
*/
/**@file tnet_dns_resolvconf.c
 * @brief Parser for "/etc/resolv.conf" file to retrive DNS servers.
 *
 * @author Mamadou Diop <diopmamadou(at)doubango.org>
 *
 * @date Created: Sat Nov 8 16:54:58 2009 mdiop
 */
#include "tnet_dns_resolvconf.h"

#include "tnet_utils.h"

#include "dns/tnet_dns.h"

#include "tsk_string.h"
#include "tsk_memory.h"
#include "tsk_ragel_state.h"
#include "tsk_debug.h"

#include <string.h>


/* ===	Ragel state machine === */

/* #line 80 "./ragel/tnet_dns_resolvconf.rl" */


/** Gets list of DNS servers from a conf file.
* @param path Path of the conf file from which to retrieve the DNS servers.
* should be @a "/etc/resolv.conf". You can adjust the value by modifying @ref TNET_RESOLV_CONF_PATH.<br>
* If you are using <b>Android</b> and the resolv.conf file is missing, then run the following line in a command window: <br>
* <i>ln -s /private/var/run/resolv.conf /etc/resolv.conf</i><br> If this fails, then try to manually add the file.
* @retval List of DNS servers.
*/
tnet_addresses_L_t * tnet_dns_resolvconf_parse(const char* path)
{
	tnet_addresses_L_t* servers = tsk_null;
	tnet_ip_t ip;
	const char* fullpath = path;
	const char* tag_start;
	FILE* fd;
	char buf[4092];
	
	// Ragel
	int cs = 0;
	const char *p;
	const char *pe;
	const char *eof;

	
/* #line 74 "./src/dns/tnet_dns_resolvconf.c" */
static const char _tdns_machine_resolvconf_actions[] = {
	0, 1, 0, 1, 1
};

static const char _tdns_machine_resolvconf_key_offsets[] = {
	0, 6, 7, 8, 11, 14, 14, 20, 
	22, 25, 28, 31, 34, 37, 40, 43, 
	46, 49, 50, 51, 54
};

static const char _tdns_machine_resolvconf_trans_keys[] = {
	10, 13, 32, 35, 78, 110, 32, 32, 
	10, 13, 32, 10, 13, 32, 10, 13, 
	32, 35, 78, 110, 10, 13, 32, 65, 
	97, 32, 77, 109, 32, 69, 101, 32, 
	83, 115, 32, 69, 101, 32, 82, 114, 
	32, 86, 118, 32, 69, 101, 32, 82, 
	114, 32, 32, 10, 13, 32, 32, 35, 
	78, 110, 0
};

static const char _tdns_machine_resolvconf_single_lengths[] = {
	6, 1, 1, 3, 3, 0, 6, 2, 
	3, 3, 3, 3, 3, 3, 3, 3, 
	3, 1, 1, 3, 4
};

static const char _tdns_machine_resolvconf_range_lengths[] = {
	0, 0, 0, 0, 0, 0, 0, 0, 
	0, 0, 0, 0, 0, 0, 0, 0, 
	0, 0, 0, 0, 0
};

static const char _tdns_machine_resolvconf_index_offsets[] = {
	0, 7, 9, 11, 15, 19, 20, 27, 
	30, 34, 38, 42, 46, 50, 54, 58, 
	62, 66, 68, 70, 74
};

static const char _tdns_machine_resolvconf_indicies[] = {
	1, 1, 2, 3, 4, 4, 0, 5, 
	0, 5, 6, 7, 7, 8, 6, 7, 
	7, 8, 9, 9, 1, 1, 5, 3, 
	4, 4, 0, 7, 7, 3, 5, 10, 
	10, 0, 5, 11, 11, 0, 5, 12, 
	12, 0, 5, 13, 13, 0, 5, 14, 
	14, 0, 5, 15, 15, 0, 5, 16, 
	16, 0, 5, 17, 17, 0, 5, 18, 
	18, 0, 19, 0, 19, 20, 22, 22, 
	23, 21, 2, 3, 4, 4, 0, 0
};

static const char _tdns_machine_resolvconf_trans_targs[] = {
	1, 6, 20, 7, 8, 2, 3, 0, 
	4, 5, 9, 10, 11, 12, 13, 14, 
	15, 16, 17, 18, 19, 19, 0, 4
};

static const char _tdns_machine_resolvconf_trans_actions[] = {
	0, 0, 0, 0, 0, 0, 0, 0, 
	0, 0, 0, 0, 0, 0, 0, 0, 
	0, 0, 0, 0, 1, 0, 3, 3
};

static const int tdns_machine_resolvconf_start = 0;
static const int tdns_machine_resolvconf_first_final = 0;
static const int tdns_machine_resolvconf_error = -1;

static const int tdns_machine_resolvconf_en_main = 0;


/* #line 105 "./ragel/tnet_dns_resolvconf.rl" */

	if(tsk_strnullORempty(fullpath)){
		fullpath = TNET_RESOLV_CONF_PATH;
	}

	/* Open the file and read all data */
	if((fd = fopen(fullpath, "r"))){
		int len = fread(buf, sizeof(uint8_t), sizeof(buf)-2, fd);
		p = &buf[0];
		pe = p + len + 1/*hack*/;
		eof = pe;
		fclose(fd);
		
		buf[len] = '\n'; // hack to have perfect lines

		servers = tsk_list_create();
	}
	else{
#if ANDROID
		TSK_DEBUG_INFO("Failed to open [%s]. But don't panic, we have detected that you are using Google Android System.\n"
			"You should look at the Progammer's Guide for more information.\n If you are not using DNS functions, don't worry about this warning.", 
			fullpath);
#else
		TSK_DEBUG_ERROR("Failed to open %s.", fullpath);
#endif
		goto bail;
	}

	
/* #line 176 "./src/dns/tnet_dns_resolvconf.c" */
	{
	cs = tdns_machine_resolvconf_start;
	}

/* #line 134 "./ragel/tnet_dns_resolvconf.rl" */
	
/* #line 183 "./src/dns/tnet_dns_resolvconf.c" */
	{
	int _klen;
	unsigned int _trans;
	const char *_acts;
	unsigned int _nacts;
	const char *_keys;

	if ( p == pe )
		goto _test_eof;
_resume:
	_keys = _tdns_machine_resolvconf_trans_keys + _tdns_machine_resolvconf_key_offsets[cs];
	_trans = _tdns_machine_resolvconf_index_offsets[cs];

	_klen = _tdns_machine_resolvconf_single_lengths[cs];
	if ( _klen > 0 ) {
		const char *_lower = _keys;
		const char *_mid;
		const char *_upper = _keys + _klen - 1;
		while (1) {
			if ( _upper < _lower )
				break;

			_mid = _lower + ((_upper-_lower) >> 1);
			if ( (*p) < *_mid )
				_upper = _mid - 1;
			else if ( (*p) > *_mid )
				_lower = _mid + 1;
			else {
				_trans += (_mid - _keys);
				goto _match;
			}
		}
		_keys += _klen;
		_trans += _klen;
	}

	_klen = _tdns_machine_resolvconf_range_lengths[cs];
	if ( _klen > 0 ) {
		const char *_lower = _keys;
		const char *_mid;
		const char *_upper = _keys + (_klen<<1) - 2;
		while (1) {
			if ( _upper < _lower )
				break;

			_mid = _lower + (((_upper-_lower) >> 1) & ~1);
			if ( (*p) < _mid[0] )
				_upper = _mid - 2;
			else if ( (*p) > _mid[1] )
				_lower = _mid + 2;
			else {
				_trans += ((_mid - _keys)>>1);
				goto _match;
			}
		}
		_trans += _klen;
	}

_match:
	_trans = _tdns_machine_resolvconf_indicies[_trans];
	cs = _tdns_machine_resolvconf_trans_targs[_trans];

	if ( _tdns_machine_resolvconf_trans_actions[_trans] == 0 )
		goto _again;

	_acts = _tdns_machine_resolvconf_actions + _tdns_machine_resolvconf_trans_actions[_trans];
	_nacts = (unsigned int) *_acts++;
	while ( _nacts-- > 0 )
	{
		switch ( *_acts++ )
		{
	case 0:
/* #line 47 "./ragel/tnet_dns_resolvconf.rl" */
	{
		tag_start = p;
	}
	break;
	case 1:
/* #line 51 "./ragel/tnet_dns_resolvconf.rl" */
	{
		int len = (int)(p  - tag_start);
		if(len && len<=sizeof(ip)){
			tnet_address_t *address;
			memset(ip, '\0', sizeof(ip));
			memcpy(ip, tag_start, len);
			
			address = tnet_address_create(ip);
			address->family = tnet_get_family(ip, TNET_DNS_SERVER_PORT_DEFAULT);
			address->dnsserver = 1;
			tsk_list_push_ascending_data(servers, (void**)&address);
		}
	}
	break;
/* #line 277 "./src/dns/tnet_dns_resolvconf.c" */
		}
	}

_again:
	if ( ++p != pe )
		goto _resume;
	_test_eof: {}
	}

/* #line 135 "./ragel/tnet_dns_resolvconf.rl" */
	
	if( cs < 
/* #line 290 "./src/dns/tnet_dns_resolvconf.c" */
0
/* #line 136 "./ragel/tnet_dns_resolvconf.rl" */
 ){
		TSK_DEBUG_ERROR("Failed to parse %s.", fullpath);
		TSK_OBJECT_SAFE_FREE(servers);
	}

bail:
	return servers;
}


