google-dns-ips 0.1.0

Resolve Google IP CIDR ranges from published DNS TXT records

google-dns-ips

Python library that resolves Google-published IP ranges from DNS TXT records.

It parses SPF-style TXT records (including nested include: records) and extracts all ip4: and ip6: CIDRs.

Why DNS TXT?

Google publishes network ranges in DNS TXT records such as:

• _netblocks.google.com
• _netblocks2.google.com
• _netblocks3.google.com
• _spf.google.com
• _cloud-netblocks.googleusercontent.com

This package also resolves host records (A/AAAA), by default dns.google, and includes those addresses as /32 or /128 networks.

This library recursively walks those records and returns normalized ranges.

Install

From the project root:

pip install -e .

Library Usage

from google_dns_ips import GoogleIPQuery, get_google_ip_cidrs

result = get_google_ip_cidrs()
query = GoogleIPQuery.from_cidrs(result.cidrs)

print(query.contains("8.8.8.8"))
print(query.collides("8.8.8.0/24"))
print(query.contains("8.8.0.0-8.8.255.255"))

result is a ResolutionResult with:

• cidrs: sorted tuple of unique CIDR strings
• visited_records: sorted tuple of DNS names visited during recursion

GoogleIPQuery supports:

• contains(value): full containment for IP, CIDR, or range string (start-end)
• collides(value): any overlap for IP, CIDR, or range string (start-end)
• Specific methods: contains_ip, contains_cidr, contains_range, collides_ip, collides_cidr, collides_range

Example Script

Run:

python examples/print_google_ips.py

Flask JSON Server Example

Run:

python examples/flask_server.py

All endpoints return JSON.

Examples:

curl "http://127.0.0.1:5001/health"
curl "http://127.0.0.1:5001/metadata"
curl "http://127.0.0.1:5001/cidrs"
curl "http://127.0.0.1:5001/networks"
curl "http://127.0.0.1:5001/check?value=8.8.8.8"
curl "http://127.0.0.1:5001/check?value=8.8.8.0/24"
curl "http://127.0.0.1:5001/check?value=8.8.0.0-8.8.255.255"
curl "http://127.0.0.1:5001/check/range?start=8.8.8.0&end=8.8.8.255"

Full Endpoint List (127.0.0.1)

Base URL:

http://127.0.0.1:5001

1. GET /health

curl "http://127.0.0.1:5001/health"

2. GET /metadata

curl "http://127.0.0.1:5001/metadata"

3. GET /cidrs

curl "http://127.0.0.1:5001/cidrs"

4. GET /networks

curl "http://127.0.0.1:5001/networks"

5. GET /check with required query param value

IP examples:

curl "http://127.0.0.1:5001/check?value=8.8.8.8"
curl "http://127.0.0.1:5001/check?value=2001:4860:4860::8888"

CIDR examples:

curl "http://127.0.0.1:5001/check?value=8.8.8.0/24"
curl "http://127.0.0.1:5001/check?value=2001:4860:4860::/48"

Range examples (start-end):

curl "http://127.0.0.1:5001/check?value=8.8.0.0-8.8.255.255"
curl "http://127.0.0.1:5001/check?value=2001:4860:4860::8888-2001:4860:4860::8899"

Error examples:

curl "http://127.0.0.1:5001/check"
curl "http://127.0.0.1:5001/check?value=not-an-ip"
curl "http://127.0.0.1:5001/check?value=1.1.1.1-2001:4860:4860::8888"

6. GET /check/range with required query params start and end

IPv4 range examples:

curl "http://127.0.0.1:5001/check/range?start=8.8.8.0&end=8.8.8.255"
curl "http://127.0.0.1:5001/check/range?start=8.8.8.255&end=8.8.8.0"

IPv6 range example:

curl "http://127.0.0.1:5001/check/range?start=2001:4860:4860::8888&end=2001:4860:4860::8899"

Error examples:

curl "http://127.0.0.1:5001/check/range"
curl "http://127.0.0.1:5001/check/range?start=8.8.8.8"
curl "http://127.0.0.1:5001/check/range?start=8.8.8.8&end=2001:4860:4860::8888"
curl "http://127.0.0.1:5001/check/range?start=bad&end=input"

7. GET unknown route (JSON 404)

curl "http://127.0.0.1:5001/not-found"