DNS host name to IP address resolver.

Author: Adam Dunkels adam@.nosp@m.dunk.nosp@m.els.c.nosp@m.om

This file implements a DNS host name to IP address resolver.

#include "net/ip/tcpip.h"
#include "net/ip/resolv.h"
#include "net/ip/uip-udp-packet.h"
#include "ip64-addr.h"
#include "compiler.h"
#include "mdns.h"
#include <string.h>
#include <stdio.h>
#include <stdbool.h>

Data Structures
struct	dns_answer

struct	dns_hdr

struct	namemap

Macros
#define	CONTIKI_CONF_DEFAULT_HOSTNAME "contiki"

#define	DNS_CLASS_ANY (255)

#define	DNS_CLASS_IN (1)

#define	DNS_FLAG1_AUTHORATIVE 0x04

#define	DNS_FLAG1_OPCODE_INVERSE 0x08

#define	DNS_FLAG1_OPCODE_STANDARD 0x00

#define	DNS_FLAG1_OPCODE_STATUS 0x10

#define	DNS_FLAG1_RD 0x01

#define	DNS_FLAG1_RESPONSE 0x80

#define	DNS_FLAG1_TRUNC 0x02

#define	DNS_FLAG2_ERR_MASK 0x0f

#define	DNS_FLAG2_ERR_NAME 0x03

#define	DNS_FLAG2_ERR_NONE 0x00

#define	DNS_FLAG2_RA 0x80

#define	DNS_PORT (53)

#define	DNS_TYPE_A (1)

#define	DNS_TYPE_AAAA (1) /* XXX temporarily fake A records */

#define	DNS_TYPE_ANY (255)

#define	DNS_TYPE_CNAME (5)

#define	DNS_TYPE_MX (15)

#define	DNS_TYPE_PTR (12)

#define	DNS_TYPE_SRV (33)

#define	DNS_TYPE_TXT (16)

#define	MDNS_CONF_MAX_DOMAIN_NAME_SIZE (32)

#define	MDNS_CONF_MAX_MDNS_RETRIES (3)

#define	MDNS_CONF_MAX_RETRIES (8)

#define	MDNS_CONF_MDNS_INCLUDE_GLOBAL_V6_ADDRS (0)

#define	MDNS_CONF_MDNS_RESPONDER 0

#define	MDNS_CONF_SUPPORTS_MDNS 0

#define	MDNS_DECODE_INDEX(i) (unsigned char)(uip_ntohs(i) - 61616)

#define	MDNS_ENCODE_INDEX(i) (uip_htons(i + 61616))

#define	MDNS_ENTRIES 4

#define	MDNS_PORT (5353)

#define	MDNS_RESPONDER_PORT (5354)

#define	STATE_ASKING 2

#define	STATE_DONE 3

#define	STATE_ERROR 4

#define	STATE_NEW 1

#define	STATE_UNUSED 0

#define	VERBOSE_DEBUG 0

#define	WITH_EDNS_LIMIT_UDP_RES_PAYLOAD 1

Functions
static void	check_entries (void)

static unsigned char *	encode_name (unsigned char query, char nameptr)

void	mdns_conf (const uip_ipaddr_t *dnsserver)
	Configure a DNS server. More...

static void	mdns_found (char name, uip_ipaddr_t ipaddr)

uip_ipaddr_t *	mdns_getserver (void)
	Obtain the currently configured DNS server. More...

void	mdns_init (void)

uip_ipaddr_t *	mdns_lookup (const char *name)
	Look up a hostname in the array of known hostnames. More...

void	mdns_query (const char *name)
	Queues a name so that a question for the name will be sent out. More...

static void	newdata (void)

static unsigned char *	parse_name (unsigned char *query)

	PROCESS (mdns_process,"DNS mdnser")

	PROCESS_THREAD (mdns_process, ev, data)

Variables
static char	dns_name_without_dots [MDNS_CONF_MAX_DOMAIN_NAME_SIZE+1]

static uip_ipaddr_t	dns_server

static uint8_t	dns_server_configured = 0

static struct uip_udp_conn *	mdns_conn = NULL

process_event_t	mdns_event_found
	Event that is broadcasted when a DNS name has been resolved. More...

static const uip_ipaddr_t	mdns_mdns_addr

static struct namemap	names [MDNS_ENTRIES]

static struct etimer	retry

static uint8_t	seqno