[FS#1067] misleading output from busybox nslookup applet (lede variant) where no query type is provided

[LEDE Bugs]

A new Flyspray task has been opened.  Details are below. 

User who did this - Val Kulkov (val-kulkov) 

Attached to Project - LEDE Project
Summary - misleading output from busybox nslookup applet (lede variant) where no query type is provided
Task Type - Bug Report
Category - Base system
Status - Unconfirmed
Assigned To - 
Operating System - All
Severity - Low
Priority - Very Low
Reported Version - Trunk
Due in Version - Undecided
Due Date - Undecided
Details - LEDE_BOARD="bcm53xx/generic"
LEDE_ARCH="arm_cortex-a9"
LEDE_TAINTS="no-all busybox"
LEDE_RELEASE="LEDE Reboot SNAPSHOT r5032-9e9696a"

Description: where no query type is provided to nslookup busybox applet, nslookup assumes A + AAAA queries (if the domain argument cannot be converted into a ptr). Then, if the A query succeeds but AAAA fails (for example, no record for an IPv6 address for the given hostname), nslookup returns "Can't find hostname: No answer". The "no answer" response looks puzzling. One has to review the the nslookup applet's source code to understand that there is nothing wrong with the DNS server.

For example:

root at LEDE:~# nslookup cam1 localhost
Server:		localhost
Address:	::1#53

Name:      cam1
Address 1: 192.168.21.14
*** Can't find cam1: No answer


Suggested fix: either add type information in the response, like "type A: X.X.X.X, type AAAA: can't find hostname: no answer", or omit the AAAA response if only A record is found.


More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=1067