rename handler files

This commit renames a bunch of files to try to make it a bit less confusing;

protocol_ is now auth as they contained registration, auth and login/out flow
protocol_.*_poll is now poll.go
api.go and other generic handlers are now handlers.go

Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>

hscontrol/protocol_legacy_poll.go

@@ -1,97 +0,0 @@
-//go:build ts2019
-
-package hscontrol
-
-import (
-	"errors"
-	"io"
-	"net/http"
-
-	"github.com/gorilla/mux"
-	"github.com/juanfont/headscale/hscontrol/util"
-	"github.com/rs/zerolog/log"
-	"gorm.io/gorm"
-	"tailscale.com/tailcfg"
-	"tailscale.com/types/key"
-)
-
-// PollNetMapHandler takes care of /machine/:id/map
-//
-// This is the busiest endpoint, as it keeps the HTTP long poll that updates
-// the clients when something in the network changes.
-//
-// The clients POST stuff like HostInfo and their Endpoints here, but
-// only after their first request (marked with the ReadOnly field).
-//
-// At this moment the updates are sent in a quite horrendous way, but they kinda work.
-func (h *Headscale) PollNetMapHandler(
-	writer http.ResponseWriter,
-	req *http.Request,
-) {
-	vars := mux.Vars(req)
-	machineKeyStr, ok := vars["mkey"]
-	if !ok || machineKeyStr == "" {
-		log.Error().
-			Str("handler", "PollNetMap").
-			Msg("No machine key in request")
-		http.Error(writer, "No machine key in request", http.StatusBadRequest)
-
-		return
-	}
-	log.Trace().
-		Str("handler", "PollNetMap").
-		Str("id", machineKeyStr).
-		Msg("PollNetMapHandler called")
-	body, _ := io.ReadAll(req.Body)
-
-	var machineKey key.MachinePublic
-	err := machineKey.UnmarshalText([]byte(util.MachinePublicKeyEnsurePrefix(machineKeyStr)))
-	if err != nil {
-		log.Error().
-			Str("handler", "PollNetMap").
-			Err(err).
-			Msg("Cannot parse client key")
-
-		http.Error(writer, "Cannot parse client key", http.StatusBadRequest)
-
-		return
-	}
-	mapRequest := tailcfg.MapRequest{}
-	err = util.DecodeAndUnmarshalNaCl(body, &mapRequest, &machineKey, h.privateKey2019)
-	if err != nil {
-		log.Error().
-			Str("handler", "PollNetMap").
-			Err(err).
-			Msg("Cannot decode message")
-		http.Error(writer, "Cannot decode message", http.StatusBadRequest)
-
-		return
-	}
-
-	machine, err := h.db.GetMachineByMachineKey(machineKey)
-	if err != nil {
-		if errors.Is(err, gorm.ErrRecordNotFound) {
-			log.Warn().
-				Str("handler", "PollNetMap").
-				Msgf("Ignoring request, cannot find machine with key %s", machineKey.String())
-
-			http.Error(writer, "", http.StatusUnauthorized)
-
-			return
-		}
-		log.Error().
-			Str("handler", "PollNetMap").
-			Msgf("Failed to fetch machine from the database with Machine key: %s", machineKey.String())
-		http.Error(writer, "", http.StatusInternalServerError)
-
-		return
-	}
-
-	log.Trace().
-		Str("handler", "PollNetMap").
-		Str("id", machineKeyStr).
-		Str("machine", machine.Hostname).
-		Msg("A machine is entering polling via the legacy protocol")
-
-	h.handlePollCommon(writer, req.Context(), machine, mapRequest, false)
-}