Working on common codebase for poll, starting with legacy

protocol_legacy_poll.go

@@ -0,0 +1,94 @@
+package headscale
+
+import (
+	"errors"
+	"io"
+	"net/http"
+
+	"github.com/gorilla/mux"
+	"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(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 = decode(body, &mapRequest, &machineKey, h.privateKey)
+	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.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("Found machine in database")
+
+	h.handlePollCommon(writer, req, machine, mapRequest, false)
+}