NAME

       resolv_wrapper - A wrapper for dns name resolving or dns faking.

SYNOPSIS

       LD_PRELOAD=libresolv_wrapper.so RESOLV_WRAPPER_CONF="/path/to/resolv.conf" ./myapplication

DESCRIPTION

       resolv_wrapper makes it possible on most UNIX platforms to contact your own DNS
       implementation in your test environment. It requires socket_wrapper to be able to contact
       it. If it doesn’t work on a special platform the wrapper is able to fake DNS queries and
       return valid responses to your application.

       •   Redirects name queries to the nameservers specified in your resolv.conf

       •   Can fake DNS queries using a simple formatted DNS hosts file.

ENVIRONMENT VARIABLES

       RESOLV_WRAPPER_CONF
           This is used to specify the resolv.conf to use. The format of the resolv.conf file is
           defined in the manpage resolv.conf(5). Currently only the namserver directive is
           supported.

       RESOLV_WRAPPER_HOSTS
           This environment variable is used for faking DNS queries. It must point to a
           hosts-like text file that specifies fake records for custom queries. The format of the
           file looks like this:

               TYPE    RECORD_NAME RECORD_VALUE

       For example:

           A       dc.cwrap.org 127.0.0.10
           AAAA    dc.cwrap.org fd00::5357:5f0a
           CNAME   kerberos.cwrap.org dc.cwrap.org
           SRV     _kerberos._tcp.cwrap.org kerberos.cwrap.org 88
           URI     _vpn.cwrap.org https://vpn.cwrap.org/VPN
           TXT     cwrap.org v=spf1 mx

       RESOLV_WRAPPER_DEBUGLEVEL
           If you need to see what is going on in resolv_wrapper itself or try to find a bug, you
           can enable logging support in resolv_wrapper if you built it with debug symbols.

           •   0 = ERROR

           •   1 = WARNING

           •   2 = DEBUG

           •   3 = TRACE

       RESOLV_WRAPPER_DISABLE_DEEPBIND
           This allows you to disable deep binding in resolv_wrapper. This is useful for running
           valgrind tools or sanitizers like (address, undefined, thread).

EXAMPLE

       The following command would trick kinit(1) into using DNS servers from "./resolv.conf" for
       Kerberos service resolution:

           $ LD_PRELOAD=libresolv_wrapper.so RESOLV_WRAPPER_CONF="./resolv.conf" kinit user@EXAMPLE.COM

AUTHOR

       The Samba Team
           Author.

                                            2020-01-31                          RESOLV_WRAPPER(1)