b56b080a7c
* introduce new interface "dnsserver.Viewer", that allows a plugin implementing it to decide if a query should be routed into its server block. * add new plugin "view", that uses the new interface to enable a user to define expression based conditions that must be met for a query to be routed to its server block. Signed-off-by: Chris O'Haver <cohaver@infoblox.com>
47 lines
1.2 KiB
Go
47 lines
1.2 KiB
Go
package expression
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import (
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"context"
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"errors"
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"net"
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"github.com/coredns/coredns/plugin/metadata"
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"github.com/coredns/coredns/request"
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)
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// DefaultEnv returns the default set of custom state variables and functions available to for use in expression evaluation.
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func DefaultEnv(ctx context.Context, state *request.Request) map[string]interface{} {
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return map[string]interface{}{
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"incidr": func(ipStr, cidrStr string) (bool, error) {
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ip := net.ParseIP(ipStr)
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if ip == nil {
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return false, errors.New("first argument is not an IP address")
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}
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_, cidr, err := net.ParseCIDR(cidrStr)
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if err != nil {
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return false, err
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}
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return cidr.Contains(ip), nil
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},
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"metadata": func(label string) string {
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f := metadata.ValueFunc(ctx, label)
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if f == nil {
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return ""
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}
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return f()
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},
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"type": state.Type,
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"name": state.Name,
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"class": state.Class,
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"proto": state.Proto,
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"size": state.Len,
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"client_ip": state.IP,
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"port": state.Port,
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"id": func() int { return int(state.Req.Id) },
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"opcode": func() int { return state.Req.Opcode },
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"do": state.Do,
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"bufsize": state.Size,
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"server_ip": state.LocalIP,
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"server_port": state.LocalPort,
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}
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}
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