10db2a80df
* Add middleware/cache Add a caching middleware that caches nxdomain, nodata and successful responses. It differentiates between DNSSEC on normal DNS replies. Each reply is compress and scrubbed so it will fit the specific client asking for it. * first simple test, less exporting of stuff * more * Add middleware/cache Add a caching middleware that caches nxdomain, nodata and successful responses. It differentiates between DNSSEC on normal DNS replies. Each reply is compressed and scrubbed so it will fit the specific client asking for it. The TTL is decremented with the time spend in the cache. There is syntax that allows you to cap the TTL for all records, no matter what. This allows for a shortlived cache, just to absorb query peaks. +Tests * cache test infrastructure * Testing
44 lines
1.1 KiB
Go
44 lines
1.1 KiB
Go
package cache
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import (
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"github.com/miekg/coredns/middleware"
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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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// ServeDNS implements the middleware.Handler interface.
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func (c Cache) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
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state := middleware.State{W: w, Req: r}
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qname := state.Name()
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qtype := state.QType()
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zone := middleware.Zones(c.Zones).Matches(qname)
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if zone == "" {
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return c.Next.ServeDNS(ctx, w, r)
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}
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do := state.Do() // might need more from OPT record?
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if i, ok := c.Get(qname, qtype, do); ok {
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resp := i.toMsg(r)
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state.SizeAndDo(resp)
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w.WriteMsg(resp)
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return dns.RcodeSuccess, nil
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}
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crr := NewCachingResponseWriter(w, c.cache, c.cap)
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return c.Next.ServeDNS(ctx, crr, r)
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}
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func (c Cache) Get(qname string, qtype uint16, do bool) (*item, bool) {
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nxdomain := nameErrorKey(qname, do)
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if i, ok := c.cache.Get(nxdomain); ok {
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return i.(*item), true
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}
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successOrNoData := successKey(qname, qtype, do)
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if i, ok := c.cache.Get(successOrNoData); ok {
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return i.(*item), true
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}
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return nil, false
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}
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