07159c8d87
Signed-off-by: Krzysztof Narkiewicz <knarkiewicz@bloomberg.net> Signed-off-by: Krzysztof Narkiewicz <knarkiewicz@bloomberg.net> Co-authored-by: Krzysztof Narkiewicz <knarkiewicz@bloomberg.net>
27 lines
731 B
Go
27 lines
731 B
Go
// Package bufsize implements a plugin that clamps EDNS0 buffer size preventing packet fragmentation.
|
|
package bufsize
|
|
|
|
import (
|
|
"context"
|
|
|
|
"github.com/coredns/coredns/plugin"
|
|
|
|
"github.com/miekg/dns"
|
|
)
|
|
|
|
// Bufsize implements bufsize plugin.
|
|
type Bufsize struct {
|
|
Next plugin.Handler
|
|
Size int
|
|
}
|
|
|
|
// ServeDNS implements the plugin.Handler interface.
|
|
func (buf Bufsize) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
|
|
if option := r.IsEdns0(); option != nil && int(option.UDPSize()) > buf.Size {
|
|
option.SetUDPSize(uint16(buf.Size))
|
|
}
|
|
return plugin.NextOrFailure(buf.Name(), buf.Next, ctx, w, r)
|
|
}
|
|
|
|
// Name implements the Handler interface.
|
|
func (buf Bufsize) Name() string { return "bufsize" }
|