mirror of
https://github.com/coredns/coredns.git
synced 2025-11-04 03:03:14 -05:00
5b844b5017
* plugin/forward: add it This moves coredns/forward into CoreDNS. Fixes as a few bugs, adds a policy option and more tests to the plugin. Update the documentation, test IPv6 address and add persistent tests. * Always use random policy when spraying * include scrub fix here as well * use correct var name * Code review * go vet * Move logging to metrcs * Small readme updates * Fix readme
67 lines
1.5 KiB
Go
67 lines
1.5 KiB
Go
// Package forward implements a forwarding proxy. It caches an upstream net.Conn for some time, so if the same
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// client returns the upstream's Conn will be precached. Depending on how you benchmark this looks to be
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// 50% faster than just openening a new connection for every client. It works with UDP and TCP and uses
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// inband healthchecking.
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package forward
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import (
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"strconv"
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"time"
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"github.com/coredns/coredns/request"
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"github.com/miekg/dns"
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"golang.org/x/net/context"
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)
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func (p *Proxy) connect(ctx context.Context, state request.Request, forceTCP, metric bool) (*dns.Msg, error) {
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start := time.Now()
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proto := state.Proto()
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if forceTCP {
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proto = "tcp"
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}
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if p.host.tlsConfig != nil {
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proto = "tcp-tls"
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}
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conn, err := p.Dial(proto)
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if err != nil {
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return nil, err
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}
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// Set buffer size correctly for this client.
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conn.UDPSize = uint16(state.Size())
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if conn.UDPSize < 512 {
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conn.UDPSize = 512
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}
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conn.SetWriteDeadline(time.Now().Add(timeout))
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if err := conn.WriteMsg(state.Req); err != nil {
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conn.Close() // not giving it back
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return nil, err
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}
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conn.SetReadDeadline(time.Now().Add(timeout))
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ret, err := conn.ReadMsg()
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if err != nil {
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conn.Close() // not giving it back
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return nil, err
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}
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p.Yield(conn)
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if metric {
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rc, ok := dns.RcodeToString[ret.Rcode]
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if !ok {
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rc = strconv.Itoa(ret.Rcode)
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}
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RequestCount.WithLabelValues(p.host.addr).Add(1)
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RcodeCount.WithLabelValues(rc, p.host.addr).Add(1)
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RequestDuration.WithLabelValues(p.host.addr).Observe(time.Since(start).Seconds())
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}
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return ret, nil
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}
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