minor bugs in nx_dns.c

Hi all,

working on nx_dns.c versio 6.1.12

I found some minor bugs.

In function
3911 _nx_dns_host_resource_data_by_name_get()
we have a
NX_DNS_QUERY_FAILED 0xA3 /* DNS query failed; no DNS server sent an 'answer' */

return value on most errors, end even if we got a reply.

It seems that it is due to line 4052

4052 return(NX_DNS_QUERY_FAILED);

while

4052 return(status);

would return actual error.

You can test this searching a non existing domain name (e.g. goo4gle.com) or setting server address to a non existing dns server (e.g 91.1.1.1).

Digging deeper, I found another non optimal return value in function

4888 _nx_dns_response_process()

Here we have
NX_DNS_SERVER_AUTH_ERROR 0xAC /* Server not able to authenticate answer/authority data*/
for any reply with reply code 0x2, 0x3, 0x6, 0x7, but not alla are errors.

Can be reproduced as before with non-existing domain.

it comes from line 4039 nad folowing
if ((status & NX_DNS_ERROR_MASK) == NX_DNS_ERROR_MASK)
{

/* Release the source packet. */
nx_packet_release(packet_ptr);

return NX_DNS_SERVER_AUTH_ERROR;
}

Best would be to add in nx_dns.h

#define NX_DNS_REPLY_CODE_OK 0xB8 /* base value for reply code management */

#define NX_DNS_REPLY_CODE_FORMERR 0xB9 /* DNS Query Format Error */

#define NX_DNS_REPLY_CODE_SERVFAIL 0xBA /* Server failed to complete the DNS request */

#define NX_DNS_REPLY_CODE_NXDOMAIN 0xBB /* Domain name does not exist */

#define NX_DNS_REPLY_CODE_NOTIMP 0xBC /* Function not implemented */

#define NX_DNS_REPLY_CODE_REFUSED 0xBD /* The server refused to answer for the query */

#define NX_DNS_REPLY_CODE_YXDOMAIN 0xBE /* Name that should not exist, does exist */

#define NX_DNS_REPLY_CODE_XRRSET 0xBF /* RRset that should not exist, does exist */

#define NX_DNS_REPLY_CODE_NOTAUTH 0xE0 /* Server not authoritative for the zone */

#define NX_DNS_REPLY_CODE_NOTZONE 0xE1 /* Name not in zone */

and change

4939 if (((status & NX_DNS_QUERY_MASK) == NX_DNS_RESPONSE_FLAG) && ((status & NX_DNS_RCODE_MASK) != NX_DNS_RCODE_SUCCESS))
{

/* Release the source packet. */
nx_packet_release(packet_ptr);

return (NX_DNS_REPLY_CODE_OK + (status & NX_DNS_RCODE_MASK));
}
This allows to take proper action if required.