/*************************************************************************
 *
 * Copyright (C) 2018-2020 Ruilin Peng (Nick) <pymumu@gmail.com>.
 *
 * smartdns 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.
 *
 * smartdns 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 this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef _DNS_CONF
#define _DNS_CONF

#include "art.h"
#include "conf.h"
#include "dns.h"
#include "dns_client.h"
#include "hash.h"
#include "hashtable.h"
#include "list.h"
#include "radix.h"

#ifdef __cpluscplus
extern "C" {
#endif

#define DNS_MAX_BIND_IP 16
#define DNS_MAX_SERVERS 64
#define DNS_MAX_SERVER_NAME_LEN 128
#define DNS_MAX_IPSET_NAMELEN 32
#define DNS_GROUP_NAME_LEN 32
#define DNS_NAX_GROUP_NUMBER 16
#define DNS_MAX_IPLEN 64
#define DNS_MAX_SPKI_LEN 64
#define DNS_MAX_URL_LEN 256
#define DNS_MAX_PATH 1024
#define DEFAULT_DNS_PORT 53
#define DEFAULT_DNS_TLS_PORT 853
#define DEFAULT_DNS_HTTPS_PORT 443
#define DNS_MAX_CONF_CNAME_LEN 256
#define SMARTDNS_CONF_FILE "/etc/smartdns/smartdns.conf"
#define SMARTDNS_LOG_FILE "/var/log/smartdns.log"
#define SMARTDNS_AUDIT_FILE "/var/log/smartdns-audit.log"

enum domain_rule {
	DOMAIN_RULE_FLAGS = 0,
	DOMAIN_RULE_ADDRESS_IPV4,
	DOMAIN_RULE_ADDRESS_IPV6,
	DOMAIN_RULE_IPSET,
	DOMAIN_RULE_NAMESERVER,
	DOMAIN_RULE_MAX,
};

typedef enum {
	DNS_BIND_TYPE_UDP,
	DNS_BIND_TYPE_TCP,
	DNS_BIND_TYPE_TLS,
} DNS_BIND_TYPE;

#define DOMAIN_CHECK_NONE 0
#define DOMAIN_CHECK_ICMP 1
#define DOMAIN_CHECK_TCP 2
#define DOMAIN_CHECK_NUM 2

#define DOMAIN_FLAG_ADDR_SOA (1 << 0)
#define DOMAIN_FLAG_ADDR_IPV4_SOA (1 << 1)
#define DOMAIN_FLAG_ADDR_IPV6_SOA (1 << 2)
#define DOMAIN_FLAG_ADDR_IGN (1 << 3)
#define DOMAIN_FLAG_ADDR_IPV4_IGN (1 << 4)
#define DOMAIN_FLAG_ADDR_IPV6_IGN (1 << 5)
#define DOMAIN_FLAG_IPSET_IGNORE (1 << 6)
#define DOMAIN_FLAG_NAMESERVER_IGNORE (1 << 7)

#define SERVER_FLAG_EXCLUDE_DEFAULT (1 << 0)

#define BIND_FLAG_NO_RULE_ADDR (1 << 0)
#define BIND_FLAG_NO_RULE_NAMESERVER (1 << 1)
#define BIND_FLAG_NO_RULE_IPSET (1 << 2)
#define BIND_FLAG_NO_RULE_SNIPROXY (1 << 3)
#define BIND_FLAG_NO_RULE_SOA (1 << 4)
#define BIND_FLAG_NO_SPEED_CHECK (1 << 5)
#define BIND_FLAG_NO_CACHE (1 << 6)
#define BIND_FLAG_NO_DUALSTACK_SELECTION (1 << 7)

struct dns_rule_flags {
	unsigned int flags;
};

struct dns_address_IPV4 {
	unsigned char ipv4_addr[DNS_RR_A_LEN];
};

struct dns_address_IPV6 {
	unsigned char ipv6_addr[DNS_RR_AAAA_LEN];
};

struct dns_ipset_name {
	struct hlist_node node;
	char ipsetname[DNS_MAX_IPSET_NAMELEN];
};

struct dns_ipset_rule {
	const char *ipsetname;
};

struct dns_domain_rule {
	void *rules[DOMAIN_RULE_MAX];
};

struct dns_nameserver_rule {
	const char *group_name;
};

struct dns_server_groups {
	struct hlist_node node;
	char group_name[DNS_GROUP_NAME_LEN];
	int server_num;
	struct dns_servers *servers[DNS_MAX_SERVERS];
};

struct dns_domain_check_order {
	char order[DOMAIN_CHECK_NUM];
	unsigned short tcp_port;
};

struct dns_group_table {
	DECLARE_HASHTABLE(group, 8);
};
extern struct dns_group_table dns_group_table;

struct dns_servers {
	char server[DNS_MAX_IPLEN];
	unsigned short port;
	unsigned int result_flag;
	unsigned int server_flag;
	int ttl;
	dns_server_type_t type;
	char spki[DNS_MAX_SPKI_LEN];
	char hostname[DNS_MAX_CNAME_LEN];
	char httphost[DNS_MAX_CNAME_LEN];
	char tls_host_verify[DNS_MAX_CNAME_LEN];
	char path[DNS_MAX_URL_LEN];
};

/* ip address lists of domain */
struct dns_bogus_ip_address {
	struct hlist_node node;
	dns_type_t addr_type;
	union {
		unsigned char ipv4_addr[DNS_RR_A_LEN];
		unsigned char ipv6_addr[DNS_RR_AAAA_LEN];
		unsigned char addr[0];
	};
};

enum address_rule {
	ADDRESS_RULE_BLACKLIST = 1,
	ADDRESS_RULE_WHITELIST = 2,
	ADDRESS_RULE_BOGUS = 3,
	ADDRESS_RULE_IP_IGNORE = 4,
};

struct dns_ip_address_rule {
	unsigned int blacklist : 1;
	unsigned int whitelist : 1;
	unsigned int bogus : 1;
	unsigned int ip_ignore : 1;
};

struct dns_edns_client_subnet {
	int enable;
	char ip[DNS_MAX_IPLEN];
	int subnet;
};

struct dns_conf_address_rule {
	radix_tree_t *ipv4;
	radix_tree_t *ipv6;
};

struct dns_bind_ip {
	DNS_BIND_TYPE type;
	uint32_t flags;
	char ip[DNS_MAX_IPLEN];
	const char *group;
};

extern struct dns_bind_ip dns_conf_bind_ip[DNS_MAX_BIND_IP];
extern int dns_conf_bind_ip_num;

extern int dns_conf_tcp_idle_time;
extern int dns_conf_cachesize;
extern int dns_conf_prefetch;
extern struct dns_servers dns_conf_servers[DNS_MAX_SERVERS];
extern int dns_conf_server_num;

extern int dns_conf_log_level;
extern char dns_conf_log_file[DNS_MAX_PATH];
extern size_t dns_conf_log_size;
extern int dns_conf_log_num;

extern struct dns_domain_check_order dns_conf_check_order;

extern struct dns_server_groups dns_conf_server_groups[DNS_NAX_GROUP_NUMBER];
extern int dns_conf_server_group_num;

extern int dns_conf_audit_enable;
extern int dns_conf_audit_log_SOA;
extern char dns_conf_audit_file[DNS_MAX_PATH];
extern size_t dns_conf_audit_size;
extern int dns_conf_audit_num;

extern char dns_conf_server_name[DNS_MAX_SERVER_NAME_LEN];
extern art_tree dns_conf_domain_rule;
extern struct dns_conf_address_rule dns_conf_address_rule;

extern int dns_conf_dualstack_ip_selection;
extern int dns_conf_dualstack_ip_selection_threshold;

extern int dns_conf_rr_ttl;
extern int dns_conf_rr_ttl_min;
extern int dns_conf_rr_ttl_max;
extern int dns_conf_force_AAAA_SOA;
extern int dns_conf_ipset_timeout_enable;

extern struct dns_edns_client_subnet dns_conf_ipv4_ecs;
extern struct dns_edns_client_subnet dns_conf_ipv6_ecs;

extern char dns_conf_sni_proxy_ip[DNS_MAX_IPLEN];

void dns_server_load_exit(void);

int dns_server_load_conf(const char *file);

extern int config_addtional_file(void *data, int argc, char *argv[]);
#ifdef __cpluscplus
}
#endif
#endif // !_DNS_CONF
