README
¶
siit
Name
siit - enables AAAA->A translation support for DNS records based on SIIT (IPv6->IPv4 translation).
Description
The siit plugin will when asked for a domain's A record, synthesizes it from a corresponding AAAA record if it belongs to a certain IP range.
It also supports arbitrary mapping IPv6->IPv4.
It is useful when published services are IPv6-only and emit their AAAA record accordingly but IPv4 clients reach them through a siit routing. This plugin generates the associated A records for these clients automatically.
Syntax
siit {
ipv6_prefix IPV6PREFIX
eam IPV4 IPV6
}
ipv6_prefixspecifies any local IPv6 prefix to use, instead of the well known prefix (64:ff9b::/96)eamtranslates the ipv6 to the corresponding ipv4, it can be set multiple times
Examples
. {
siit {
ipv6_prefix 64:1337::/96
}
}
Metrics
If monitoring is enabled (via the prometheus plugin) then the following metrics are exported:
coredns_siit_requests_translated_total{server}- counter of DNS requests translated
The server label is explained in the prometheus plugin documentation.
Bugs
- Prefix matching in eam is not implemented yet.
- DNSSEC support is not implemented yet. The problem is the same as DNS64. See: RFC 6147 Section 3
See Also
See RFC 6052 for more information on the SIIT mechanism and RFC 7757 about the explicit address mappings (eam) mechanism
Notes
This plugin is heavily based on dns64 plugin.
Documentation
¶
Overview ¶
Package siit implements a plugin that performs AAAA to A translation.
See: RFC 6052 (https://www.rfc-editor.org/info/rfc6052/) See: RFC 7757 (https://www.rfc-editor.org/info/rfc7757/)
Index ¶
- Variables
- type SIIT
- func (d *SIIT) DoSIIT(ctx context.Context, w dns.ResponseWriter, r *dns.Msg, origResponse *dns.Msg) (*dns.Msg, bool, error)
- func (d *SIIT) Name() string
- func (d *SIIT) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error)
- func (d *SIIT) Synthesize(origReq, origResponse, resp *dns.Msg) (*dns.Msg, bool)
- type UpstreamInt
Constants ¶
This section is empty.
Variables ¶
var ( // RequestsTranslatedCount is the number of DNS requests translated by siit. RequestsTranslatedCount = promauto.NewCounterVec(prometheus.CounterOpts{ Namespace: plugin.Namespace, Subsystem: pluginName, Name: "requests_translated_total", Help: "Counter of DNS requests translated by siit.", }, []string{"server"}) )
Functions ¶
This section is empty.
Types ¶
type SIIT ¶
type SIIT struct {
Next plugin.Handler
IPv6Prefix *net.IPNet
Eam4 map[string]net.IP
Upstream UpstreamInt
}
SIIT performs SIIT.
func (*SIIT) DoSIIT ¶
func (d *SIIT) DoSIIT(ctx context.Context, w dns.ResponseWriter, r *dns.Msg, origResponse *dns.Msg) (*dns.Msg, bool, error)
DoSIIT takes an (empty) response to an A question, issues the AAAA request, and synthesizes the answer. Returns the response message, or error on internal failure.
func (*SIIT) Synthesize ¶
Synthesize merges the AAAA response and the records from the A response. The bool return reports whether at least one AAAA record was actually translated into a synthetic A record. false means the caller got back origResponse unchanged — nothing in the AAAA answer was mappable (no EAM entry, and the address wasn't in ipv6_prefix) — and this must not be counted as a translated request.
Source Files