PowerDNS protobuf receiver

The pdns_protobuf_receiver is a daemon in Python 3 that acts a protobuf server for PowerDNS's products. You can use it to collect DNS queries and responses and to log to syslog or a json remote tcp collector.

Table of contents

• Installation
• Execute receiver
• Startup options
• Output JSON format
• PowerDNS configuration
• About

Installation

PyPI

From pypi, deploy the pdns_protobuf_receiver with the pip command. Only Python3 is supported.

pip install pdns-protobuf-receiver

After installation, you will have pdns_protobuf_receiver binary available

Docker Hub

Pull the pdns-protobuf-receiver image from Docker Hub.

docker pull dmachard/pdns-protobuf-receiver:latest

Deploy the container

docker run -d -p 50001:50001 --name=pdns-pb01 dmachard/pdns-protobuf-receiver

Follow containers logs

docker logs pdns-pb01 -f

Execute receiver

The receiver is listening by default on the 0.0.0.0 interface and 50001 tcp port

If you want to print DNS queries and responses to stdout in JSON format, then execute the pdns_protobuf receiver as below:

# pdns_protobuf_receiver -v
2020-05-29 18:39:08,579 Start pdns protobuf receiver...
2020-05-29 18:39:08,580 Using selector: EpollSelector

If you want to resend protobuf message to your remote tcp collector Start the pdns_protobuf receiver as below:

# pdns_protobuf_receiver -j 10.0.0.235:6000 -v
2020-05-29 18:39:08,579 Start pdns protobuf receiver...
2020-05-29 18:39:08,580 Using selector: EpollSelector
2020-05-29 18:39:08,580 Connecting to 10.0.0.235 6000
2020-05-29 18:39:08,585 Connected to 10.0.0.235 6000

Startup options

Command line options are:

usage: -c [-h] [-l L] [-j J] [-v]

optional arguments:
  -h, --help  show this help message and exit
  -l L        listen protobuf dns message on tcp/ip address <ip:port>
  -j J        write JSON payload to tcp/ip address <ip:port>
  -v          verbose mode

JSON log format

Each events generated by the pdns_protbuf receiver will have the following format:

{
    "dns_message": "AUTH_QUERY",
    "socket_family": "IPv6",
    "socket protocol": "UDP",
    "from_address": "0.0.0.0",
    "to_address": "184.26.161.130",
    "query_time": "2020-05-29 13:46:23.322",
    "response_time": "1970-01-01 01:00:00.000",
    "latency": 0,
    "query_type": "A",
    "query_name": "a13-130.akagtm.org.",
    "return_code": "NOERROR",
    "bytes": 4
}

Keys description:

• dns_message: PDNS message type (CLIENT_QUERY, CLIENT_RESPONSE, ...)
• socket_family: IP protocol used (IPv4 or IPv6)
• socket_protocol: transport protocol used (UDP or TCP)
• from_address: the querier IP address
• to_address: the destination IP address
• query_time: time of query reception
• response_time: time of response reception
• latency: difference between query and response time
• query_type: the query type (A, AAAA, NS, ...)
• query_name: the query name
• return_code: the response code sent back to the client (NXDOMAIN, NOERROR, ...)
• bytes: size in bytes of the query or response

PowerDNS configuration

You need to configure dnsdist or pdns-recursor to active remote logging.

dnsdist

Configure the dnsdist /etc/dnsdist/dnsdist.conf and add the following lines Set the newRemoteLogger function with the address of your pdns_protobuf_receiver instance.

rl = newRemoteLogger("10.0.0.97:50001")
addAction(AllRule(),RemoteLogAction(rl))
addResponseAction(AllRule(),RemoteLogResponseAction(rl))

Restart dnsdist.

pdns-recursor

Configure the powerdns recursor /etc/pdns-recursor/recursor.conf and add the following line

lua-config-file=/etc/pdns-recursor/recursor.lua

Create the LUA file /etc/pdns-recursor/recursor.lua Set the protobufServer or outgoingProtobufServer functions with the address of your pdns_protobuf receiver instance.

protobufServer("10.0.0.97:50001", {logQueries=true,
                                   logResponses=true,
                                   exportTypes={'A', 'AAAA',
                                                'CNAME', 'MX', 
                                                'PTR', 'NS',
                                                'SPF', 'SRV',
                                                'TXT'}} )
outgoingProtobufServer("10.0.0.97:50001",  {logQueries=true,
                                            logResponses=true,
                                            exportTypes={'A', 'AAAA',
                                                         'CNAME', 'MX',
                                                         'PTR', 'NS',
                                                         'SPF', 'SRV',
                                                         'TXT'}})

Restart the recursor.

About

Original Author	Denis Machard d.machard@gmail.com