Curl dns resolving not working (entware)

[krabs]

Curl dns resolving (entware) is not working for me. (stucks)
It does however works when given up an IP adres instead of an remote domain name.
Maybe it's related to the fact that I'm also running dnscrypt-proxy(entware 127.0.0.1:65053) on my rt-ac66u.
Specifying the dns-server as option returns an error: curl: (4) Error (possible feature not enabeled)


Someone any advice to get dns resolving working without rebuilding libcurl ?

 

[MercuryV]

What is exact output of curl? or nothing?
Have you tried curl with -4 option?

 

[krabs]

Have you tried curl with -4 option?

Well you just solved my problem.
From the man pages

4, --ipv4
If curl is capable of resolving an address to multiple IP versions (which it is if it is IPv6-capable), this option tells curl to resolve names to IPv4 addresses only.

I do not understand why it's needed as I'm using only ipv4 but it just works now.

 

[RMerlin]

Well you just solved my problem.
From the man pages

4, --ipv4
If curl is capable of resolving an address to multiple IP versions (which it is if it is IPv6-capable), this option tells curl to resolve names to IPv4 addresses only.

I do not understand why it's needed as I'm using only ipv4 but it just works now.

I remember ryzhov_al mentionned something in the past concerning IPv6 resolution and Entware. Try to search the forums here to track down his post, I don't remember the details.

 

[MercuryV]

Here is example

# nslookup www.marxists.org
Server:    127.0.0.1
Address 1: 127.0.0.1 localhost.localdomain

Name:      www.marxists.org
Address 1: 2607:f358:1a:b::2 luxemburg.marxists.org
Address 2: 72.13.82.90 luxemburg.marxists.org

IPv6 address resolves first. You don't have IPv6 enabled. Curl stucks

 

[MercuryV]

I remember ryzhov_al mentionned something in the past concerning IPv6 resolution and Entware.

Here's the original post

 

[krabs]

Here's the original post

Just added

echo precedence ipv4 > /tmp/etc/gai.conf

in init-start as stated in http://code.google.com/p/wl500g/source/detail?r=4427

 

[MercuryV]

krabs, wl500g != RMerlin
It's different firmware. Not sure about /tmp/etc/gai.conf support or similar in Asuswrt-Merlin

 

[krabs]

krabs, wl500g != RMerlin
It's different firmware. Not sure about /tmp/etc/gai.conf support or similar in Asuswrt-Merlin

You're 100% right it's for sure a different firmware but it has nothing to do with merlin but entware !

Entware uClibc has support for it.
curl uses entware library uclibc

ldd curl
ld-uClibc.so.0 => /opt/lib/ld-uClibc.so.0 (0x2aaa8000)

now when executing curl google.be it just resolves fine.

It doesn't work for nslookup (merlin busybox) because it's using the standard uclibc library in /lib

ldd nslookup
ld-uClibc.so.0 => /lib/ld-uClibc.so.0

I was searching for replacing/linking (temporaly) with ldconfig /lib/ld-uClibc.so.0 to /opt/lib/ld-uClibc.so.0 for nslookup but this isn't possible (without recompiling I think)

An easier method is installing nslookup (busybox) from entware.

ldd /opt/bin/nslookup

This one use is using enware's ld-uClibc.so.0 library
Now ipv4 resolves first if gai.conf is created with precedence ipv4.
Otherwise Ipv6 resolves first.