//*****************************************************************************
|
//
|
//! \file dns.c
|
//! \brief DNS APIs Implement file.
|
//! \details Send DNS query & Receive DNS reponse. \n
|
//! It depends on stdlib.h & string.h in ansi-c library
|
//! \version 1.1.0
|
//! \date 2013/11/18
|
//! \par Revision history
|
//! <2013/10/21> 1st Release
|
//! <2013/12/20> V1.1.0
|
//! 1. Remove secondary DNS server in DNS_run
|
//! If 1st DNS_run failed, call DNS_run with 2nd DNS again
|
//! 2. DNS_timerHandler -> DNS_time_handler
|
//! 3. Remove the unused define
|
//! 4. Integrated dns.h dns.c & dns_parse.h dns_parse.c into dns.h & dns.c
|
//! <2013/12/20> V1.1.0
|
//!
|
//! \author Eric Jung & MidnightCow
|
//! \copyright
|
//!
|
//! Copyright (c) 2013, WIZnet Co., LTD.
|
//! All rights reserved.
|
//!
|
//! Redistribution and use in source and binary forms, with or without
|
//! modification, are permitted provided that the following conditions
|
//! are met:
|
//!
|
//! * Redistributions of source code must retain the above copyright
|
//! notice, this list of conditions and the following disclaimer.
|
//! * Redistributions in binary form must reproduce the above copyright
|
//! notice, this list of conditions and the following disclaimer in the
|
//! documentation and/or other materials provided with the distribution.
|
//! * Neither the name of the <ORGANIZATION> nor the names of its
|
//! contributors may be used to endorse or promote products derived
|
//! from this software without specific prior written permission.
|
//!
|
//! THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
//! AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
//! IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
//! ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
|
//! LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
//! CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
//! SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
//! INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
//! CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
//! ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
|
//! THE POSSIBILITY OF SUCH DAMAGE.
|
//
|
//*****************************************************************************
|
|
#include <string.h>
|
#include <stdlib.h>
|
|
#include "Ethernet/socket.h"
|
#include "Internet/DNS/dns.h"
|
|
#ifdef _DNS_DEBUG_
|
#include <stdio.h>
|
#endif
|
|
#define INITRTT 2000L /* Initial smoothed response time */
|
#define MAXCNAME (MAX_DOMAIN_NAME + (MAX_DOMAIN_NAME>>1)) /* Maximum amount of cname recursion */
|
|
#define TYPE_A 1 /* Host address */
|
#define TYPE_NS 2 /* Name server */
|
#define TYPE_MD 3 /* Mail destination (obsolete) */
|
#define TYPE_MF 4 /* Mail forwarder (obsolete) */
|
#define TYPE_CNAME 5 /* Canonical name */
|
#define TYPE_SOA 6 /* Start of Authority */
|
#define TYPE_MB 7 /* Mailbox name (experimental) */
|
#define TYPE_MG 8 /* Mail group member (experimental) */
|
#define TYPE_MR 9 /* Mail rename name (experimental) */
|
#define TYPE_NULL 10 /* Null (experimental) */
|
#define TYPE_WKS 11 /* Well-known sockets */
|
#define TYPE_PTR 12 /* Pointer record */
|
#define TYPE_HINFO 13 /* Host information */
|
#define TYPE_MINFO 14 /* Mailbox information (experimental)*/
|
#define TYPE_MX 15 /* Mail exchanger */
|
#define TYPE_TXT 16 /* Text strings */
|
#define TYPE_ANY 255 /* Matches any type */
|
|
#define CLASS_IN 1 /* The ARPA Internet */
|
|
/* Round trip timing parameters */
|
#define AGAIN 8 /* Average RTT gain = 1/8 */
|
#define LAGAIN 3 /* Log2(AGAIN) */
|
#define DGAIN 4 /* Mean deviation gain = 1/4 */
|
#define LDGAIN 2 /* log2(DGAIN) */
|
|
/* Header for all domain messages */
|
struct dhdr
|
{
|
uint16_t id; /* Identification */
|
uint8_t qr; /* Query/Response */
|
#define QUERY 0
|
#define RESPONSE 1
|
uint8_t opcode;
|
#define IQUERY 1
|
uint8_t aa; /* Authoratative answer */
|
uint8_t tc; /* Truncation */
|
uint8_t rd; /* Recursion desired */
|
uint8_t ra; /* Recursion available */
|
uint8_t rcode; /* Response code */
|
#define NO_ERROR 0
|
#define FORMAT_ERROR 1
|
#define SERVER_FAIL 2
|
#define NAME_ERROR 3
|
#define NOT_IMPL 4
|
#define REFUSED 5
|
uint16_t qdcount; /* Question count */
|
uint16_t ancount; /* Answer count */
|
uint16_t nscount; /* Authority (name server) count */
|
uint16_t arcount; /* Additional record count */
|
};
|
|
|
uint8_t* pDNSMSG; // DNS message buffer
|
uint8_t DNS_SOCKET; // SOCKET number for DNS
|
uint16_t DNS_MSGID; // DNS message ID
|
|
uint32_t dns_1s_tick; // for timout of DNS processing
|
|
/* converts uint16_t from network buffer to a host byte order integer. */
|
uint16_t get16(uint8_t * s)
|
{
|
uint16_t i;
|
i = *s++ << 8;
|
i = i + *s;
|
return i;
|
}
|
|
/* copies uint16_t to the network buffer with network byte order. */
|
uint8_t * put16(uint8_t * s, uint16_t i)
|
{
|
*s++ = i >> 8;
|
*s++ = i;
|
return s;
|
}
|
|
|
/*
|
* CONVERT A DOMAIN NAME TO THE HUMAN-READABLE FORM
|
*
|
* Description : This function converts a compressed domain name to the human-readable form
|
* Arguments : msg - is a pointer to the reply message
|
* compressed - is a pointer to the domain name in reply message.
|
* buf - is a pointer to the buffer for the human-readable form name.
|
* len - is the MAX. size of buffer.
|
* Returns : the length of compressed message
|
*/
|
int parse_name(uint8_t * msg, uint8_t * compressed, char * buf, int16_t len)
|
{
|
uint16_t slen; /* Length of current segment */
|
uint8_t * cp;
|
int clen = 0; /* Total length of compressed name */
|
int indirect = 0; /* Set if indirection encountered */
|
int nseg = 0; /* Total number of segments in name */
|
|
cp = compressed;
|
|
for (;;)
|
{
|
slen = *cp++; /* Length of this segment */
|
|
if (!indirect) clen++;
|
|
if ((slen & 0xc0) == 0xc0)
|
{
|
if (!indirect)
|
clen++;
|
indirect = 1;
|
/* Follow indirection */
|
cp = &msg[((slen & 0x3f)<<8) + *cp];
|
slen = *cp++;
|
}
|
|
if (slen == 0) /* zero length == all done */
|
break;
|
|
len -= slen + 1;
|
|
if (len < 0) return -1;
|
|
if (!indirect) clen += slen;
|
|
while (slen-- != 0) *buf++ = (char)*cp++;
|
*buf++ = '.';
|
nseg++;
|
}
|
|
if (nseg == 0)
|
{
|
/* Root name; represent as single dot */
|
*buf++ = '.';
|
len--;
|
}
|
|
*buf++ = '\0';
|
len--;
|
|
return clen; /* Length of compressed message */
|
}
|
|
/*
|
* PARSE QUESTION SECTION
|
*
|
* Description : This function parses the qeustion record of the reply message.
|
* Arguments : msg - is a pointer to the reply message
|
* cp - is a pointer to the qeustion record.
|
* Returns : a pointer the to next record.
|
*/
|
uint8_t * dns_question(uint8_t * msg, uint8_t * cp)
|
{
|
int len;
|
char name[MAXCNAME];
|
|
len = parse_name(msg, cp, name, MAXCNAME);
|
|
|
if (len == -1) return 0;
|
|
cp += len;
|
cp += 2; /* type */
|
cp += 2; /* class */
|
|
return cp;
|
}
|
|
|
/*
|
* PARSE ANSER SECTION
|
*
|
* Description : This function parses the answer record of the reply message.
|
* Arguments : msg - is a pointer to the reply message
|
* cp - is a pointer to the answer record.
|
* Returns : a pointer the to next record.
|
*/
|
uint8_t * dns_answer(uint8_t * msg, uint8_t * cp, uint8_t * ip_from_dns)
|
{
|
int len, type;
|
char name[MAXCNAME];
|
|
len = parse_name(msg, cp, name, MAXCNAME);
|
|
if (len == -1) return 0;
|
|
cp += len;
|
type = get16(cp);
|
cp += 2; /* type */
|
cp += 2; /* class */
|
cp += 4; /* ttl */
|
cp += 2; /* len */
|
|
|
switch (type)
|
{
|
case TYPE_A:
|
/* Just read the address directly into the structure */
|
ip_from_dns[0] = *cp++;
|
ip_from_dns[1] = *cp++;
|
ip_from_dns[2] = *cp++;
|
ip_from_dns[3] = *cp++;
|
break;
|
case TYPE_CNAME:
|
case TYPE_MB:
|
case TYPE_MG:
|
case TYPE_MR:
|
case TYPE_NS:
|
case TYPE_PTR:
|
/* These types all consist of a single domain name */
|
/* convert it to ascii format */
|
len = parse_name(msg, cp, name, MAXCNAME);
|
if (len == -1) return 0;
|
|
cp += len;
|
break;
|
case TYPE_HINFO:
|
len = *cp++;
|
cp += len;
|
|
len = *cp++;
|
cp += len;
|
break;
|
case TYPE_MX:
|
cp += 2;
|
/* Get domain name of exchanger */
|
len = parse_name(msg, cp, name, MAXCNAME);
|
if (len == -1) return 0;
|
|
cp += len;
|
break;
|
case TYPE_SOA:
|
/* Get domain name of name server */
|
len = parse_name(msg, cp, name, MAXCNAME);
|
if (len == -1) return 0;
|
|
cp += len;
|
|
/* Get domain name of responsible person */
|
len = parse_name(msg, cp, name, MAXCNAME);
|
if (len == -1) return 0;
|
|
cp += len;
|
|
cp += 4;
|
cp += 4;
|
cp += 4;
|
cp += 4;
|
cp += 4;
|
break;
|
case TYPE_TXT:
|
/* Just stash */
|
break;
|
default:
|
/* Ignore */
|
break;
|
}
|
|
return cp;
|
}
|
|
/*
|
* PARSE THE DNS REPLY
|
*
|
* Description : This function parses the reply message from DNS server.
|
* Arguments : dhdr - is a pointer to the header for DNS message
|
* buf - is a pointer to the reply message.
|
* len - is the size of reply message.
|
* Returns : -1 - Domain name lenght is too big
|
* 0 - Fail (Timout or parse error)
|
* 1 - Success,
|
*/
|
int8_t parseDNSMSG(struct dhdr * pdhdr, uint8_t * pbuf, uint8_t * ip_from_dns)
|
{
|
uint16_t tmp;
|
uint16_t i;
|
uint8_t * msg;
|
uint8_t * cp;
|
|
msg = pbuf;
|
memset(pdhdr, 0, sizeof(pdhdr));
|
|
pdhdr->id = get16(&msg[0]);
|
tmp = get16(&msg[2]);
|
if (tmp & 0x8000) pdhdr->qr = 1;
|
|
pdhdr->opcode = (tmp >> 11) & 0xf;
|
|
if (tmp & 0x0400) pdhdr->aa = 1;
|
if (tmp & 0x0200) pdhdr->tc = 1;
|
if (tmp & 0x0100) pdhdr->rd = 1;
|
if (tmp & 0x0080) pdhdr->ra = 1;
|
|
pdhdr->rcode = tmp & 0xf;
|
pdhdr->qdcount = get16(&msg[4]);
|
pdhdr->ancount = get16(&msg[6]);
|
pdhdr->nscount = get16(&msg[8]);
|
pdhdr->arcount = get16(&msg[10]);
|
|
|
/* Now parse the variable length sections */
|
cp = &msg[12];
|
|
/* Question section */
|
for (i = 0; i < pdhdr->qdcount; i++)
|
{
|
cp = dns_question(msg, cp);
|
#ifdef _DNS_DEUBG_
|
printf("MAX_DOMAIN_NAME is too small, it should be redfine in dns.h"
|
#endif
|
if(!cp) return -1;
|
}
|
|
/* Answer section */
|
for (i = 0; i < pdhdr->ancount; i++)
|
{
|
cp = dns_answer(msg, cp, ip_from_dns);
|
#ifdef _DNS_DEUBG_
|
printf("MAX_DOMAIN_NAME is too small, it should be redfine in dns.h"
|
#endif
|
if(!cp) return -1;
|
}
|
|
/* Name server (authority) section */
|
for (i = 0; i < pdhdr->nscount; i++)
|
{
|
;
|
}
|
|
/* Additional section */
|
for (i = 0; i < pdhdr->arcount; i++)
|
{
|
;
|
}
|
|
if(pdhdr->rcode == 0) return 1; // No error
|
else return 0;
|
}
|
|
|
/*
|
* MAKE DNS QUERY MESSAGE
|
*
|
* Description : This function makes DNS query message.
|
* Arguments : op - Recursion desired
|
* name - is a pointer to the domain name.
|
* buf - is a pointer to the buffer for DNS message.
|
* len - is the MAX. size of buffer.
|
* Returns : the pointer to the DNS message.
|
*/
|
int16_t dns_makequery(uint16_t op, char * name, uint8_t * buf, uint16_t len)
|
{
|
uint8_t *cp;
|
char *cp1;
|
char sname[MAXCNAME];
|
char *dname;
|
uint16_t p;
|
uint16_t dlen;
|
|
cp = buf;
|
|
DNS_MSGID++;
|
cp = put16(cp, DNS_MSGID);
|
p = (op << 11) | 0x0100; /* Recursion desired */
|
cp = put16(cp, p);
|
cp = put16(cp, 1);
|
cp = put16(cp, 0);
|
cp = put16(cp, 0);
|
cp = put16(cp, 0);
|
|
strcpy(sname, name);
|
dname = sname;
|
dlen = strlen(dname);
|
for (;;)
|
{
|
/* Look for next dot */
|
cp1 = strchr(dname, '.');
|
|
if (cp1 != NULL) len = cp1 - dname; /* More to come */
|
else len = dlen; /* Last component */
|
|
*cp++ = len; /* Write length of component */
|
if (len == 0) break;
|
|
/* Copy component up to (but not including) dot */
|
strncpy((char *)cp, dname, len);
|
cp += len;
|
if (cp1 == NULL)
|
{
|
*cp++ = 0; /* Last one; write null and finish */
|
break;
|
}
|
dname += len+1;
|
dlen -= len+1;
|
}
|
|
cp = put16(cp, 0x0001); /* type */
|
cp = put16(cp, 0x0001); /* class */
|
|
return ((int16_t)((uint32_t)(cp) - (uint32_t)(buf)));
|
}
|
|
/*
|
* CHECK DNS TIMEOUT
|
*
|
* Description : This function check the DNS timeout
|
* Arguments : None.
|
* Returns : -1 - timeout occurred, 0 - timer over, but no timeout, 1 - no timer over, no timeout occur
|
* Note : timeout : retry count and timer both over.
|
*/
|
|
int8_t check_DNS_timeout(void)
|
{
|
static uint8_t retry_count;
|
|
if(dns_1s_tick >= DNS_WAIT_TIME)
|
{
|
dns_1s_tick = 0;
|
if(retry_count >= MAX_DNS_RETRY) {
|
retry_count = 0;
|
return -1; // timeout occurred
|
}
|
retry_count++;
|
return 0; // timer over, but no timeout
|
}
|
|
return 1; // no timer over, no timeout occur
|
}
|
|
|
|
/* DNS CLIENT INIT */
|
void DNS_init(uint8_t s, uint8_t * buf)
|
{
|
DNS_SOCKET = s; // SOCK_DNS
|
pDNSMSG = buf; // User's shared buffer
|
DNS_MSGID = DNS_MSG_ID;
|
}
|
|
/* DNS CLIENT RUN */
|
int8_t DNS_run(uint8_t * dns_ip, uint8_t * name, uint8_t * ip_from_dns)
|
{
|
int8_t ret;
|
struct dhdr dhp;
|
uint8_t ip[4];
|
uint16_t len, port;
|
int8_t ret_check_timeout;
|
|
// Socket open
|
socket(DNS_SOCKET, Sn_MR_UDP, 0, 0);
|
|
#ifdef _DNS_DEBUG_
|
printf("> DNS Query to DNS Server : %d.%d.%d.%d\r\n", dns_ip[0], dns_ip[1], dns_ip[2], dns_ip[3]);
|
#endif
|
|
len = dns_makequery(0, (char *)name, pDNSMSG, MAX_DNS_BUF_SIZE);
|
sendto(DNS_SOCKET, pDNSMSG, len, dns_ip, IPPORT_DOMAIN);
|
|
while (1)
|
{
|
if ((len = getSn_RX_RSR(DNS_SOCKET)) > 0)
|
{
|
if (len > MAX_DNS_BUF_SIZE) len = MAX_DNS_BUF_SIZE;
|
len = recvfrom(DNS_SOCKET, pDNSMSG, len, ip, &port);
|
#ifdef _DNS_DEBUG_
|
printf("> Receive DNS message from %d.%d.%d.%d(%d). len = %d\r\n", ip[0], ip[1], ip[2], ip[3],port,len);
|
#endif
|
ret = parseDNSMSG(&dhp, pDNSMSG, ip_from_dns);
|
break;
|
}
|
// Check Timeout
|
ret_check_timeout = check_DNS_timeout();
|
if (ret_check_timeout < 0) {
|
|
#ifdef _DNS_DEBUG_
|
printf("> DNS Server is not responding : %d.%d.%d.%d\r\n", dns_ip[0], dns_ip[1], dns_ip[2], dns_ip[3]);
|
#endif
|
return 0; // timeout occurred
|
}
|
else if (ret_check_timeout == 0) {
|
|
#ifdef _DNS_DEBUG_
|
printf("> DNS Timeout\r\n");
|
#endif
|
sendto(DNS_SOCKET, pDNSMSG, len, dns_ip, IPPORT_DOMAIN);
|
}
|
}
|
close(DNS_SOCKET);
|
// Return value
|
// 0 > : failed / 1 - success
|
return ret;
|
}
|
|
|
/* DNS TIMER HANDLER */
|
void DNS_time_handler(void)
|
{
|
dns_1s_tick++;
|
}
|
