error_t mdnsAddIpv4ResourceRecord(NetInterface *interface,
DnsHeader *message, size_t *length, bool_t flush)
{
#if (IPV4_SUPPORT == ENABLED)
size_t n;
size_t offset;
DnsResourceRecord *resourceRecord;
//Set the position to the end of the buffer
offset = *length;
//The first pass calculates the length of the DNS encoded host name
n = mdnsEncodeName(interface->hostname, "", ".local", NULL);
//Check the length of the resulting mDNS message
if((offset + n) > MDNS_MESSAGE_MAX_SIZE)
return ERROR_MESSAGE_TOO_LONG;
//The second pass encodes the host name using the DNS name notation
offset += mdnsEncodeName(interface->hostname, "",
".local", (uint8_t *) message + offset);
//Consider the length of the resource record itself
n = sizeof(DnsResourceRecord) + sizeof(Ipv4Addr);
//Check the length of the resulting mDNS message
if((offset + n) > MDNS_MESSAGE_MAX_SIZE)
return ERROR_MESSAGE_TOO_LONG;
//Point to the corresponding resource record
resourceRecord = DNS_GET_RESOURCE_RECORD(message, offset);
//Check whether the cache-fluch bit should be set
if(flush)
resourceRecord->rclass = HTONS(MDNS_RCLASS_CACHE_FLUSH | DNS_RR_CLASS_IN);
else
resourceRecord->rclass = HTONS(DNS_RR_CLASS_IN);
//Fill in resource record
resourceRecord->rtype = HTONS(DNS_RR_TYPE_A);
resourceRecord->ttl = HTONL(MDNS_DEFAULT_RESOURCE_RECORD_TTL);
resourceRecord->rdlength = HTONS(sizeof(Ipv4Addr));
//Copy IPv4 address
ipv4CopyAddr(resourceRecord->rdata, &interface->ipv4Config.addr);
//Number of resource records in the answer section
message->ancount++;
//Update the length of the mDNS response message
*length = offset + n;
#endif
//Successful processing
return NO_ERROR;
}
error_t dhcpDumpIpv4Addr(const DhcpOption *option)
{
Ipv4Addr ipAddr;
//Check option length
if(option->length != sizeof(Ipv4Addr))
return ERROR_INVALID_OPTION;
//Retrieve IPv4 address
ipv4CopyAddr(&ipAddr, option->value);
//Dump option contents
TRACE_DEBUG(" %s\r\n", ipv4AddrToString(ipAddr, NULL));
//No error to report
return NO_ERROR;
}
int_t gethostbyname(const char_t *name, hostent *info)
{
error_t error;
IpAddr ipAddr;
//Check input parameters
if(!name || !info)
return ERROR_INVALID_PARAMETER;
//Resolve host address
error = getHostByName(NULL, name, &ipAddr, 1, NULL, 0);
//Address resolution failed?
if(error) return error;
#if (IPV4_SUPPORT == ENABLED)
//IPv4 address?
if(ipAddr.length == sizeof(Ipv4Addr))
{
//Set address family
info->h_addrtype = AF_INET;
//Copy IPv4 address
info->h_length = sizeof(Ipv4Addr);
ipv4CopyAddr(info->h_addr, &ipAddr.ipv4Addr);
}
else
#endif
#if (IPV6_SUPPORT == ENABLED)
//IPv6 address?
if(ipAddr.length == sizeof(Ipv6Addr))
{
//Set address family
info->h_addrtype = AF_INET6;
//Copy IPv6 address
info->h_length = sizeof(Ipv6Addr);
ipv6CopyAddr(info->h_addr, &ipAddr.ipv6Addr);
}
else
#endif
//Invalid address?
{
//Report an error
return ERROR_FAILURE;
}
//Successful processing
return NO_ERROR;
}
error_t dhcpDumpIpv4AddrList(const DhcpOption *option)
{
size_t i;
Ipv4Addr ipAddr;
//Check option length
if((option->length % sizeof(Ipv4Addr)) != 0)
return ERROR_INVALID_OPTION;
//Parse the list of IPv4 addresses
for(i = 0; i < option->length; i += sizeof(Ipv4Addr))
{
//Retrieve the current IPv4 address
ipv4CopyAddr(&ipAddr, option->value + i);
//Display current address
TRACE_DEBUG(" %s\r\n", ipv4AddrToString(ipAddr, NULL));
}
//No error to report
return NO_ERROR;
}
error_t ipcpDumpOptions(const PppOption *option, size_t length)
{
#if (IPV4_SUPPORT == ENABLED)
Ipv4Addr ipAddr;
#endif
//Parse options
while(length > 0)
{
//Malformed IPCP packet?
if(length < sizeof(PppOption))
return ERROR_INVALID_LENGTH;
//Check option length
if(option->length < sizeof(PppOption))
return ERROR_INVALID_LENGTH;
if(option->length > length)
return ERROR_INVALID_LENGTH;
//Display the name of the current option
if(option->type < arraysize(ipcpOptionLabel))
TRACE_DEBUG(" %s option (%" PRIu8 " bytes)\r\n", ipcpOptionLabel[option->type], option->length);
else if(option->type >= 128 && option->type < (128 + arraysize(ipcpOptionLabel2)))
TRACE_DEBUG(" %s option (%" PRIu8 " bytes)\r\n", ipcpOptionLabel2[option->type - 128], option->length);
else
TRACE_DEBUG(" Option %" PRIu8 " (%" PRIu8 " bytes)\r\n", option->type, option->length);
//Check option code
switch(option->type)
{
#if (IPV4_SUPPORT == ENABLED)
//IP address?
case IPCP_OPTION_IP_ADDRESS:
case IPCP_OPTION_PRIMARY_DNS:
case IPCP_OPTION_PRIMARY_NBNS:
case IPCP_OPTION_SECONDARY_DNS:
case IPCP_OPTION_SECONDARY_NBNS:
//Check length field
if(option->length != (sizeof(PppOption) + sizeof(Ipv4Addr)))
return ERROR_INVALID_OPTION;
//Retrieve IPv4 address
ipv4CopyAddr(&ipAddr, option->data);
//Dump option contents
TRACE_DEBUG(" %s\r\n", ipv4AddrToString(ipAddr, NULL));
break;
#endif
//Raw data?
default:
//Dump option contents
TRACE_DEBUG_ARRAY(" ", option->data, option->length - sizeof(PppOption));
break;
}
//Remaining bytes to process
length -= option->length;
//Jump to the next option
option = (PppOption *) ((uint8_t *) option + option->length);
}
//No error to report
return NO_ERROR;
}
error_t dnsParseResponse(DnsHeader *dnsMessage, size_t length, uint16_t identifier, IpAddr *ipAddr)
{
char_t *name;
uint_t i;
size_t pos;
Ipv4Addr ipv4Addr;
DnsQuestion *dnsQuestion;
DnsResourceRecord *dnsResourceRecord;
//Clear host address
memset(ipAddr, 0, sizeof(IpAddr));
//Ensure the DNS header is valid
if(length < sizeof(DnsHeader))
return ERROR_INVALID_HEADER;
//Compare identifier against expected one
if(dnsMessage->identifier != identifier)
return ERROR_WRONG_IDENTIFIER;
//Check message type
if(!(dnsMessage->flags & DNS_FLAG_QR))
return ERROR_INVALID_HEADER;
//Make sure recursion is available
if(!(dnsMessage->flags & DNS_FLAG_RA))
return ERROR_INVALID_HEADER;
//Check return code
if(dnsMessage->flags & DNS_RCODE_MASK)
return ERROR_FAILURE;
//Debug message
TRACE_DEBUG("DNS response message received (%u bytes)...\r\n", length);
//Allocate memory buffer to hold the decoded name
name = memPoolAlloc(DNS_NAME_MAX_SIZE);
//Failed to allocate memory
if(!name) return ERROR_OUT_OF_MEMORY;
//Debug message
TRACE_DEBUG("%u questions found...\r\n", ntohs(dnsMessage->questionCount));
//Point to the first question
pos = sizeof(DnsHeader);
//Parse questions
for(i = 0; i < ntohs(dnsMessage->questionCount); i++)
{
//Decode domain name
pos = dnsDecodeName(dnsMessage, length, pos, name);
//Name decoding failed?
if(!pos)
{
//Free previously allocated memory
osMemFree(name);
//Report an error
return ERROR_INVALID_NAME;
}
//Point to the associated resource record
dnsQuestion = DNS_GET_RESOURCE_RECORD(dnsMessage, pos);
//Debug message
TRACE_DEBUG(" name = %s\r\n", name);
TRACE_DEBUG(" queryType = %u\r\n", ntohs(dnsQuestion->queryType));
TRACE_DEBUG(" queryClass = %u\r\n", ntohs(dnsQuestion->queryClass));
//Point to the next question
pos += sizeof(DnsQuestion);
}
//Debug message
TRACE_INFO("%u answer RRs found...\r\n", ntohs(dnsMessage->answerRecordCount));
//Parse answer resource records
for(i = 0; i < ntohs(dnsMessage->answerRecordCount); i++)
{
//Decode domain name
pos = dnsDecodeName(dnsMessage, length, pos, name);
//Name decoding failed?
if(!pos)
{
//Free previously allocated memory
osMemFree(name);
//Report an error
return ERROR_INVALID_NAME;
}
//Point to the associated resource record
dnsResourceRecord = DNS_GET_RESOURCE_RECORD(dnsMessage, pos);
//Debug message
TRACE_DEBUG(" name = %s\r\n", name);
TRACE_DEBUG(" type = %u\r\n", ntohs(dnsResourceRecord->type));
TRACE_DEBUG(" class = %u\r\n", ntohs(dnsResourceRecord->class));
TRACE_DEBUG(" ttl = %u\r\n", ntohl(dnsResourceRecord->timeToLive));
TRACE_DEBUG(" dataLength = %u\r\n", ntohs(dnsResourceRecord->dataLength));
//Check the type of the resource record
switch(ntohs(dnsResourceRecord->type))
{
//IPv4 address record found?
case DNS_RR_TYPE_A:
//Verify the length of the data field
if(ntohs(dnsResourceRecord->dataLength) != sizeof(Ipv4Addr))
break;
//Copy the IP address
ipv4CopyAddr(&ipv4Addr, dnsResourceRecord->data);
//Save the first IP address found in resource records
if(!ipAddr->length)
{
ipAddr->length = sizeof(Ipv4Addr);
ipAddr->ipv4Addr = ipv4Addr;
}
//Debug message
TRACE_DEBUG(" data = %s\r\n", ipv4AddrToString(ipv4Addr, NULL));
break;
//IPv6 address record found?
/*case DNS_RR_TYPE_AAAA:
//Verify the length of the data field
if(ntohs(dnsResourceRecord->dataLength) != sizeof(Ipv6Addr))
break;
//Copy the IP address
//ipv4CopyAddr(&ipv4Addr, dnsResourceRecord->data);
//Save the first IP address found in resource records
if(!ipAddr->length)
{
ipAddr->length = sizeof(Ipv6Addr);
ipv6CopyAddr(&ipAddr->ipv6Addr, dnsResourceRecord->data);
}
//Debug message
//TRACE_DEBUG(" data = %s\r\n", ipv4AddrToString(ipv4Addr, NULL));
break;*/
//Name server record found?
case DNS_RR_TYPE_NS:
//Canonical name record found?
case DNS_RR_TYPE_CNAME:
//Pointer record?
case DNS_RR_TYPE_PTR:
//Decode the canonical name
dnsDecodeName(dnsMessage, length, pos + sizeof(DnsResourceRecord), name);
//Debug message
TRACE_DEBUG(" data = %s\r\n", name);
break;
//Unknown record
default:
break;
}
//Point to the next resource record
pos += sizeof(DnsResourceRecord) + ntohs(dnsResourceRecord->dataLength);
}
//Debug message
TRACE_INFO("%u authority RRs found...\r\n", ntohs(dnsMessage->authorityRecordCount));
TRACE_INFO("%u additional RRs found...\r\n", ntohs(dnsMessage->additionalRecordCount));
//Free previously allocated memory
osMemFree(name);
//DNS response successfully decoded
return NO_ERROR;
}
void dnsProcessResponse(NetInterface *interface, const IpPseudoHeader *pseudoHeader,
const UdpHeader *udpHeader, const ChunkedBuffer *buffer, size_t offset, void *params)
{
uint_t i;
uint_t j;
size_t n;
size_t pos;
size_t length;
DnsHeader *message;
DnsQuestion *question;
DnsResourceRecord *resourceRecord;
DnsCacheEntry *entry;
//Retrieve the length of the DNS message
length = chunkedBufferGetLength(buffer) - offset;
//Ensure the DNS message is valid
if(length < sizeof(DnsHeader))
return;
if(length > DNS_MESSAGE_MAX_SIZE)
return;
//Point to the DNS message header
message = chunkedBufferAt(buffer, offset);
//Sanity check
if(!message) return;
//Debug message
TRACE_INFO("DNS message received (%" PRIuSIZE " bytes)...\r\n", length);
//Dump message
dnsDumpMessage(message, length);
//Acquire exclusive access to the DNS cache
osMutexAcquire(dnsCacheMutex);
//Loop through DNS cache entries
for(i = 0; i < DNS_CACHE_SIZE; i++)
{
//Point to the current entry
entry = &dnsCache[i];
//DNS name resolution in progress?
if(entry->state == DNS_STATE_IN_PROGRESS &&
entry->protocol == HOST_NAME_RESOLVER_DNS)
{
//Check destination port number
if(entry->port == ntohs(udpHeader->destPort))
{
//Compare identifier against expected one
if(ntohs(message->id) != entry->id)
break;
//Check message type
if(!message->qr)
break;
//The DNS message shall contain one question
if(ntohs(message->qdcount) != 1)
break;
//Point to the first question
pos = sizeof(DnsHeader);
//Parse domain name
n = dnsParseName(message, length, pos, NULL, 0);
//Invalid name?
if(!n)
break;
//Malformed mDNS message?
if((n + sizeof(DnsQuestion)) > length)
break;
//Compare domain name
if(!dnsCompareName(message, length, pos, entry->name, 0))
break;
//Point to the corresponding entry
question = DNS_GET_QUESTION(message, n);
//Check the class of the query
if(ntohs(question->qclass) != DNS_RR_CLASS_IN)
break;
//Check the type of the query
if(entry->type == HOST_TYPE_IPV4 && ntohs(question->qtype) != DNS_RR_TYPE_A)
break;
if(entry->type == HOST_TYPE_IPV6 && ntohs(question->qtype) != DNS_RR_TYPE_AAAA)
break;
//Make sure recursion is available
if(!message->ra)
{
//The entry should be deleted since name resolution has failed
dnsDeleteEntry(entry);
//Exit immediately
break;
}
//Check return code
if(message->rcode != DNS_RCODE_NO_ERROR)
{
//The entry should be deleted since name resolution has failed
dnsDeleteEntry(entry);
//Exit immediately
break;
}
//Point to the first answer
pos = n + sizeof(DnsQuestion);
//Parse answer resource records
for(j = 0; j < ntohs(message->ancount); j++)
{
//Parse domain name
pos = dnsParseName(message, length, pos, NULL, 0);
//Invalid name?
if(!pos) break;
//Point to the associated resource record
resourceRecord = DNS_GET_RESOURCE_RECORD(message, pos);
//Point to the resource data
pos += sizeof(DnsResourceRecord);
//Make sure the resource record is valid
if(pos >= length)
break;
if((pos + ntohs(resourceRecord->rdlength)) > length)
break;
#if (IPV4_SUPPORT == ENABLED)
//IPv4 address expected?
if(entry->type == HOST_TYPE_IPV4)
{
//A resource record found?
if(ntohs(resourceRecord->rtype) == DNS_RR_TYPE_A)
{
//Verify the length of the data field
if(ntohs(resourceRecord->rdlength) == sizeof(Ipv4Addr))
{
//Copy the IPv4 address
entry->ipAddr.length = sizeof(Ipv4Addr);
ipv4CopyAddr(&entry->ipAddr.ipv4Addr, resourceRecord->rdata);
//Save current time
entry->timestamp = osGetTickCount();
//Save TTL value
entry->timeout = ntohl(resourceRecord->ttl) * 1000;
//Limit the lifetime of the DNS cache entries
entry->timeout = min(entry->timeout, DNS_MAX_LIFETIME);
//Unregister UDP callback function
udpDetachRxCallback(interface, entry->port);
//Host name successfully resolved
entry->state = DNS_STATE_RESOLVED;
//Exit immediately
break;
}
}
}
#endif
#if (IPV6_SUPPORT == ENABLED)
//IPv6 address expected?
if(entry->type == HOST_TYPE_IPV6)
{
//AAAA resource record found?
if(ntohs(resourceRecord->rtype) == DNS_RR_TYPE_AAAA)
{
//Verify the length of the data field
if(ntohs(resourceRecord->rdlength) == sizeof(Ipv6Addr))
{
//Copy the IPv6 address
entry->ipAddr.length = sizeof(Ipv6Addr);
ipv6CopyAddr(&entry->ipAddr.ipv6Addr, resourceRecord->rdata);
//Save current time
entry->timestamp = osGetTickCount();
//Save TTL value
entry->timeout = ntohl(resourceRecord->ttl) * 1000;
//Limit the lifetime of the DNS cache entries
entry->timeout = min(entry->timeout, DNS_MAX_LIFETIME);
//Unregister UDP callback function
udpDetachRxCallback(interface, entry->port);
//Host name successfully resolved
entry->state = DNS_STATE_RESOLVED;
//Exit immediately
break;
}
}
}
#endif
//Point to the next resource record
pos += ntohs(resourceRecord->rdlength);
}
//We are done
break;
}
}
}
//Release exclusive access to the DNS cache
osMutexRelease(dnsCacheMutex);
}