Skip to content

README.md

Latest commit

 

History

History
115 lines (79 loc) · 2.86 KB

README.md

File metadata and controls

115 lines (79 loc) · 2.86 KB

mod/resolver

Name resolver for Yggdrasil. Supports three resolution strategies: .pk.ygg public key mapping, IP literals, and DNS queries over the Yggdrasil network.

Contents

Overview

flowchart LR
    Name["name"] --> PkYgg{".pk.ygg?"}
    PkYgg -->|" yes "| Decode["hex → ed25519 → IPv6"]
    PkYgg -->|" no "| IPLit{"IP literal?"}
    IPLit -->|" yes "| Return["net.IP"]
    IPLit -->|" no "| DNS{"DNS?"}
    DNS -->|" hasDNS "| Lookup["LookupIP → ip6"]
    DNS -->|" no "| Err["ErrNoNameserver"]
    Decode --> Return
    Lookup --> Return
Loading

Initialization

r := resolver.New(dialer, "200::1:53") // DNS over Yggdrasil
r := resolver.New(dialer, "") // no DNS, only .pk.ygg and literals
Parameter Description
dialer proxy.ContextDialer — dialer for DNS queries
nameserver DNS server address (host:port or host, port → 53)

If nameserver is empty — DNS resolution is disabled, only .pk.ygg and IP literals work.

The resolver uses PreferGo: true (pure Go DNS, no cgo).

Name resolution

ctx, ip, err := r.Resolve(ctx, "home.abc123def456.pk.ygg")

Returns net.IP and the original ctx (for passing values through the chain).

Strategy order

Strategies are tried in decreasing order of specificity:

  1. .pk.ygg — if the name ends with .pk.ygg
  2. IP literal — if the name parses as an IP address
  3. DNS — if a nameserver is configured

The first successful strategy wins.

.pk.ygg mapping

Suffix: NameMappingSuffix = ".pk.ygg"

<hex-encoded-ed25519-key>.pk.ygg → IPv6 via address.AddrForKey()

Subdomains are allowed — only the last segment before .pk.ygg is used:

subdomain.abc123...def456.pk.ygg → abc123...def456 is taken

The key must be exactly 32 bytes after hex decoding.

IP literals

IPv4 and IPv6 addresses are returned as-is:

200::1       → net.IP{200::1}
192.168.1.1  → net.IP{192.168.1.1}

DNS

IPv6 resolution via the configured nameserver. If no nameserver is set — ErrNoNameserver is returned.

r.resolver.LookupIP(ctx, "ip6", name)

Returns the first address found. If no addresses are found — ErrNoAddresses.

Errors

Variable Description
ErrNoNameserver DNS server is not configured
ErrNoAddresses DNS query returned no addresses
ErrInvalidKeyLength Public key is not 32 bytes