mirror of https://github.com/hashicorp/consul
90 lines
2.7 KiB
Go
90 lines
2.7 KiB
Go
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// Copyright (c) HashiCorp, Inc.
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// SPDX-License-Identifier: BUSL-1.1
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package dns
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import (
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"context"
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"fmt"
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"net"
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"github.com/hashicorp/go-hclog"
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"github.com/miekg/dns"
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"google.golang.org/grpc"
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"google.golang.org/grpc/codes"
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"google.golang.org/grpc/peer"
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"google.golang.org/grpc/status"
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"github.com/hashicorp/consul/agent/discovery"
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agentdns "github.com/hashicorp/consul/agent/dns"
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"github.com/hashicorp/consul/proto-public/pbdns"
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)
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type ConfigV2 struct {
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DNSRouter agentdns.DNSRouter
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Logger hclog.Logger
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TokenFunc func() string
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}
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var _ pbdns.DNSServiceServer = (*ServerV2)(nil)
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// ServerV2 is a gRPC server that implements pbdns.DNSServiceServer.
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// It is compatible with the refactored V2 DNS server and suitable for
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// passing additional metadata along the grpc connection to catalog queries.
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type ServerV2 struct {
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ConfigV2
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}
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func NewServerV2(cfg ConfigV2) *ServerV2 {
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return &ServerV2{cfg}
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}
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func (s *ServerV2) Register(registrar grpc.ServiceRegistrar) {
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pbdns.RegisterDNSServiceServer(registrar, s)
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}
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// Query is a gRPC endpoint that will serve dns requests. It will be consumed primarily by the
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// consul dataplane to proxy dns requests to consul.
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func (s *ServerV2) Query(ctx context.Context, req *pbdns.QueryRequest) (*pbdns.QueryResponse, error) {
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pr, ok := peer.FromContext(ctx)
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if !ok {
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return nil, fmt.Errorf("error retrieving peer information from context")
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}
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var remote net.Addr
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// We do this so that we switch to udp/tcp when handling the request since it will be proxied
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// through consul through gRPC, and we need to 'fake' the protocol so that the message is trimmed
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// according to whether it is UDP or TCP.
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switch req.GetProtocol() {
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case pbdns.Protocol_PROTOCOL_TCP:
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remote = pr.Addr
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case pbdns.Protocol_PROTOCOL_UDP:
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remoteAddr := pr.Addr.(*net.TCPAddr)
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remote = &net.UDPAddr{IP: remoteAddr.IP, Port: remoteAddr.Port}
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default:
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return nil, status.Error(codes.InvalidArgument, fmt.Sprintf("error protocol type not set: %v", req.GetProtocol()))
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}
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msg := &dns.Msg{}
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err := msg.Unpack(req.Msg)
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if err != nil {
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s.Logger.Error("error unpacking message", "err", err)
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return nil, status.Error(codes.Internal, fmt.Sprintf("failure decoding dns request: %s", err.Error()))
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}
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// TODO (v2-dns): parse token and other context metadata from the grpc request/metadata
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reqCtx := discovery.Context{
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Token: s.TokenFunc(),
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}
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resp := s.DNSRouter.HandleRequest(msg, reqCtx, remote)
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data, err := resp.Pack()
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if err != nil {
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s.Logger.Error("error packing message", "err", err)
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return nil, status.Error(codes.Internal, fmt.Sprintf("failure encoding dns request: %s", err.Error()))
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}
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queryResponse := &pbdns.QueryResponse{Msg: data}
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return queryResponse, nil
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}
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