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proone-resolv

Interactive DNS resolver tool for testing the Resolv worker functionality.

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Overview

proone-resolv provides a command-line interface to the custom DNS resolver used by Proone. It supports A, AAAA, and TXT record queries over DNS-over-TLS (DoT).

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Usage

proone-resolv
The tool reads queries from stdin and outputs results to stdout.

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Query Format

<RECORD TYPE> <DOMAIN>
Supported record types:
  • A: IPv4 address records
  • AAAA: IPv6 address records
  • TXT: Text records

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Example Session

A example.com
AAAA example.com
TXT _acme-challenge.example.com

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Output Format

For each query, the tool outputs: 
; qr: <RESULT>, err: <ERRNO>, status: (<CODE>)<RCODE>
Where:
  • <RESULT>: Query result (OK, STATUS, ERR_NS, ERR_SYS, ERRNO, TIMEOUT)
  • <ERRNO>: System error number (if applicable)
  • <CODE>: DNS response code number
  • <RCODE>: DNS response code name (NOERROR, NXDOMAIN, etc.)
Followed by resource records: 
;	type: (<NUM>)<TYPE>, ttl: <SECONDS>, len: <BYTES>, name: <NAME>
;		<DATA>

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Example Output

; qr:      OK, err:   0, status: (0)NOERROR
;	type: ( 1)    A, ttl:         60, len:     4, name: example.com
;		93.184.216.34
;

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DNS-over-TLS

The resolver uses hardcoded public DoT servers:
  • Default IPv4 pool defined in build configuration
  • Default IPv6 pool defined in build configuration
  • TLS encryption for all queries
  • Connection reuse for efficiency

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Server Selection

  • Randomly selects from pool on errors
  • Maintains connections between queries
  • Falls back to other servers on errors
  • Short connection timeout for offline detection

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Query Model

Promise-future pattern:
  1. Query is queued
  2. Future object returned
  3. Worker processes query asynchronously
  4. Results available through future

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Special Features

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TLS Configuration

  • Uses hardcoded certificate and private key
  • Makes packet analysis difficult
  • Sends “close notify” on graceful shutdown
  • Some servers may drop connection with RST (no side effects)

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Independence

  • Does not use system DNS configuration
  • Only uses hardcoded DoT servers
  • No dependency on /etc/resolv.conf

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Input Handling

  • Lines starting with # or ; are ignored (comments)
  • Empty lines are ignored
  • Invalid lines generate error messages

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Exit Codes

CodeDescription
0Success - all queries processed
1No queries processed
2Parse errors occurred
3Both parse and query errors

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Signal Handling

Terminate with:
  • SIGTERM
  • SIGINT (Ctrl+C)
  • EOF on stdin

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Threading

Uses GNU Pth for cooperative multitasking:
  • Main thread reads stdin
  • Resolver worker processes queries
  • Output worker writes results

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Binary Data

For TXT records containing binary data:
  • Prints warning on terminal
  • Outputs normally to files/pipes
  • Checks if output is a TTY

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Example Usage

# Interactive mode
proone-resolv
A google.com
AAAA google.com
^C

# Batch mode
cat <<EOF | proone-resolv
A example.com
AAAA example.com
TXT _dmarc.example.com
EOF

# From file
proone-resolv < queries.txt

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Limitations

  • Only supports A, AAAA, and TXT records
  • No support for other DNS record types
  • No DNSSEC validation
  • Hardcoded server list (compile-time configuration)

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Source

Location: src/proone-resolv.c

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