pkg/api/api0: Implement all server update endpoints

Share the same handler, conditionally allowing different fields to be
updated, controlling whether create/update is enabled based on the
endpoint, and (re)verifying servers whenever it results in a new
server being created.

2 files changed, 225 insertions, 125 deletions

diff --git a/pkg/api/api0/api.go b/pkg/api/api0/api.go
index 3f84238..d17018f 100644
--- a/pkg/api/api0/api.go
+++ b/pkg/api/api0/api.go
@@ -88,8 +88,8 @@ func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		h.handleClientAuthWithSelf(w, r)
 	case "/client/servers":
 		h.handleClientServers(w, r)
-	case "/server/add_server":
-		h.handleServerAddServer(w, r)
+	case "/server/add_server", "/server/update_values", "/server/heartbeat":
+		h.handleServerUpsert(w, r)
 	case "/accounts/write_persistence":
 		h.handleAccountsWritePersistence(w, r)
 	case "/accounts/get_username":
diff --git a/pkg/api/api0/server.go b/pkg/api/api0/server.go
index 29cbcda..1efc5c2 100644
--- a/pkg/api/api0/server.go
+++ b/pkg/api/api0/server.go
@@ -17,15 +17,30 @@ import (
 )
 
 /*
-  /server/heartbeat:
-    POST:
-  /server/update_values:
-    POST:
   /server/remove_server:
     DELETE:
 */
 
-func (h *Handler) handleServerAddServer(w http.ResponseWriter, r *http.Request) {
+func (h *Handler) handleServerUpsert(w http.ResponseWriter, r *http.Request) {
+	// note: if the API is confusing, see:
+	//  - https://github.com/R2Northstar/NorthstarLauncher/commit/753dda6231bbb2adf585bbc916c0b220e816fcdc
+	//  - https://github.com/R2Northstar/NorthstarLauncher/blob/v1.9.7/NorthstarDLL/masterserver.cpp
+
+	var isCreate, canCreate, isUpdate, canUpdate bool
+	switch r.URL.Path {
+	case "/server/add_server":
+		isCreate = true
+		canCreate = true
+	case "/server/update_values":
+		canCreate = true
+		fallthrough
+	case "/server/heartbeat":
+		isUpdate = true
+		canUpdate = true
+	default:
+		panic("unhandled path")
+	}
+
 	if r.Method != http.MethodOptions && r.Method != http.MethodPost {
 		http.Error(w, http.StatusText(http.StatusMethodNotAllowed), http.StatusMethodNotAllowed)
 		return
@@ -73,153 +88,237 @@ func (h *Handler) handleServerAddServer(w http.ResponseWriter, r *http.Request)
 		}
 	}
 
-	var s Server
-
-	if v := r.URL.Query().Get("port"); v == "" {
-		respJSON(w, r, http.StatusBadRequest, map[string]any{
-			"success": false,
-			"error":   ErrorCode_BAD_REQUEST,
-			"msg":     ErrorCode_BAD_REQUEST.Messagef("port param is required"),
-		})
-		return
-	} else if n, err := strconv.ParseUint(v, 10, 16); err != nil {
-		respJSON(w, r, http.StatusBadRequest, map[string]any{
-			"success": false,
-			"error":   ErrorCode_BAD_REQUEST,
-			"msg":     ErrorCode_BAD_REQUEST.Messagef("port param is invalid: %v", err),
-		})
-		return
-	} else {
-		s.Addr = netip.AddrPortFrom(raddr.Addr(), uint16(n))
+	var l ServerListLimit
+	if n := h.MaxServers; n > 0 {
+		l.MaxServers = n
+	} else if n == 0 {
+		l.MaxServers = 1000
+	}
+	if n := h.MaxServersPerIP; n > 0 {
+		l.MaxServersPerIP = n
+	} else if n == 0 {
+		l.MaxServersPerIP = 50
 	}
 
-	if v := r.URL.Query().Get("authPort"); v == "" {
-		respJSON(w, r, http.StatusBadRequest, map[string]any{
-			"success": false,
-			"error":   ErrorCode_BAD_REQUEST,
-			"msg":     ErrorCode_BAD_REQUEST.Messagef("authPort param is required"),
-		})
-		return
-	} else if n, err := strconv.ParseUint(v, 10, 16); err != nil {
-		respJSON(w, r, http.StatusBadRequest, map[string]any{
-			"success": false,
-			"error":   ErrorCode_BAD_REQUEST,
-			"msg":     ErrorCode_BAD_REQUEST.Messagef("authPort param is invalid: %v", err),
-		})
-		return
-	} else {
-		s.AuthPort = uint16(n)
+	var s *Server
+	if canCreate {
+		s = &Server{}
 	}
 
-	if v := r.URL.Query().Get("name"); v == "" {
-		respJSON(w, r, http.StatusBadRequest, map[string]any{
-			"success": false,
-			"error":   ErrorCode_BAD_REQUEST,
-			"msg":     ErrorCode_BAD_REQUEST.Messagef("name param must not be empty"),
-		})
-		return
-	} else {
-		// TODO: bad word censoring
-		if n := 256; len(v) > n { // NorthstarLauncher@v1.9.7 limits it to 63
-			v = v[:n]
+	var u *ServerUpdate
+	if canUpdate {
+		u = &ServerUpdate{
+			Heartbeat: true,
+			ExpectIP:  raddr.Addr(),
 		}
-		s.Name = v
 	}
 
-	if v := r.URL.Query().Get("description"); v != "" {
-		// TODO: bad word censoring
-		if n := 1024; len(v) > n { // NorthstarLauncher@v1.9.7 doesn't have a limit
-			v = v[:n]
+	if canUpdate {
+		if v := r.URL.Query().Get("id"); v == "" {
+			if isUpdate {
+				respJSON(w, r, http.StatusBadRequest, map[string]any{
+					"success": false,
+					"error":   ErrorCode_BAD_REQUEST,
+					"msg":     ErrorCode_BAD_REQUEST.Messagef("id param is required"),
+				})
+				return
+			}
+		} else {
+			u.ID = v
 		}
-		s.Description = v
 	}
 
-	if v := r.URL.Query().Get("map"); v != "" {
-		if n := 64; len(v) > n { // NorthstarLauncher@v1.9.7 limits it to 31
-			v = v[:n]
+	if canCreate {
+		if v := r.URL.Query().Get("port"); v == "" {
+			if isCreate {
+				respJSON(w, r, http.StatusBadRequest, map[string]any{
+					"success": false,
+					"error":   ErrorCode_BAD_REQUEST,
+					"msg":     ErrorCode_BAD_REQUEST.Messagef("port param is required"),
+				})
+				return
+			}
+		} else if n, err := strconv.ParseUint(v, 10, 16); err != nil {
+			respJSON(w, r, http.StatusBadRequest, map[string]any{
+				"success": false,
+				"error":   ErrorCode_BAD_REQUEST,
+				"msg":     ErrorCode_BAD_REQUEST.Messagef("port param is invalid: %v", err),
+			})
+			return
+		} else {
+			s.Addr = netip.AddrPortFrom(raddr.Addr(), uint16(n))
 		}
-		s.Map = v
-	}
 
-	if v := r.URL.Query().Get("playlist"); v != "" {
-		if n := 64; len(v) > n { // NorthstarLauncher@v1.9.7 limits it to 15
-			v = v[:n]
+		if v := r.URL.Query().Get("authPort"); v == "" {
+			if isCreate {
+				respJSON(w, r, http.StatusBadRequest, map[string]any{
+					"success": false,
+					"error":   ErrorCode_BAD_REQUEST,
+					"msg":     ErrorCode_BAD_REQUEST.Messagef("authPort param is required"),
+				})
+			}
+			return
+		} else if n, err := strconv.ParseUint(v, 10, 16); err != nil {
+			respJSON(w, r, http.StatusBadRequest, map[string]any{
+				"success": false,
+				"error":   ErrorCode_BAD_REQUEST,
+				"msg":     ErrorCode_BAD_REQUEST.Messagef("authPort param is invalid: %v", err),
+			})
+			return
+		} else {
+			s.AuthPort = uint16(n)
 		}
-		s.Playlist = v
-	}
 
-	if n, err := strconv.ParseUint(r.URL.Query().Get("maxPlayers"), 10, 8); err == nil {
-		s.MaxPlayers = int(n)
+		if v := r.URL.Query().Get("password"); len(v) > 128 {
+			if isCreate {
+				respJSON(w, r, http.StatusBadRequest, map[string]any{
+					"success": false,
+					"error":   ErrorCode_BAD_REQUEST,
+					"msg":     ErrorCode_BAD_REQUEST.Messagef("password is too long"),
+				})
+				return
+			}
+		} else {
+			s.Password = v
+		}
 	}
 
-	if v := r.URL.Query().Get("password"); len(v) > 128 {
-		respJSON(w, r, http.StatusBadRequest, map[string]any{
-			"success": false,
-			"error":   ErrorCode_BAD_REQUEST,
-			"msg":     ErrorCode_BAD_REQUEST.Messagef("password is too long"),
-		})
-		return
-	} else {
-		s.Password = v
+	if canCreate || canUpdate {
+		if v := r.URL.Query().Get("name"); v == "" {
+			if isCreate {
+				respJSON(w, r, http.StatusBadRequest, map[string]any{
+					"success": false,
+					"error":   ErrorCode_BAD_REQUEST,
+					"msg":     ErrorCode_BAD_REQUEST.Messagef("name param must not be empty"),
+				})
+				return
+			}
+		} else {
+			// TODO: bad word censoring
+			if n := 256; len(v) > n { // NorthstarLauncher@v1.9.7 limits it to 63
+				v = v[:n]
+			}
+			if canCreate {
+				s.Name = v
+			}
+			if canUpdate {
+				u.Name = &v
+			}
+		}
+
+		if v := r.URL.Query().Get("description"); v != "" {
+			// TODO: bad word censoring
+			if n := 1024; len(v) > n { // NorthstarLauncher@v1.9.7 doesn't have a limit
+				v = v[:n]
+			}
+			if canCreate {
+				s.Description = v
+			}
+			if canUpdate {
+				u.Description = &v
+			}
+		}
+
+		if v := r.URL.Query().Get("map"); v != "" {
+			if n := 64; len(v) > n { // NorthstarLauncher@v1.9.7 limits it to 31
+				v = v[:n]
+			}
+			if canCreate {
+				s.Map = v
+			}
+			if canUpdate {
+				u.Map = &v
+			}
+		}
+
+		if v := r.URL.Query().Get("playlist"); v != "" {
+			if n := 64; len(v) > n { // NorthstarLauncher@v1.9.7 limits it to 15
+				v = v[:n]
+			}
+			if canCreate {
+				s.Playlist = v
+			}
+			if canUpdate {
+				u.Playlist = &v
+			}
+		}
+
+		if n, err := strconv.ParseUint(r.URL.Query().Get("playerCount"), 10, 8); err == nil {
+			if canCreate {
+				s.MaxPlayers = int(n)
+			}
+			if canUpdate {
+				s.MaxPlayers = int(n)
+			}
+		}
+
+		if n, err := strconv.ParseUint(r.URL.Query().Get("maxPlayers"), 10, 8); err == nil {
+			if canCreate {
+				s.MaxPlayers = int(n)
+			}
+			if canUpdate {
+				s.MaxPlayers = int(n)
+			}
+		}
 	}
 
-	var modInfoErr error
-	if err := r.ParseMultipartForm(1 << 18 /*.25 MB*/); err == nil {
-		if mf, mfHdr, err := r.FormFile("modinfo"); err == nil {
-			if mfHdr.Size < 1<<18 {
-				var obj struct {
-					Mods []struct {
-						Name             string `json:"Name"`
-						Version          string `json:"Version"`
-						RequiredOnClient bool   `json:"RequiredOnClient"`
-					} `json:"Mods"`
-				}
-				if err := json.NewDecoder(mf).Decode(&obj); err == nil {
-					for _, m := range obj.Mods {
-						if m.Name != "" {
-							if m.Version == "" {
-								m.Version = "0.0.0"
+	if canCreate {
+		var modInfoErr error
+		if err := r.ParseMultipartForm(1 << 18 /*.25 MB*/); err == nil {
+			if mf, mfHdr, err := r.FormFile("modinfo"); err == nil {
+				if mfHdr.Size < 1<<18 {
+					var obj struct {
+						Mods []struct {
+							Name             string `json:"Name"`
+							Version          string `json:"Version"`
+							RequiredOnClient bool   `json:"RequiredOnClient"`
+						} `json:"Mods"`
+					}
+					if err := json.NewDecoder(mf).Decode(&obj); err == nil {
+						for _, m := range obj.Mods {
+							if m.Name != "" {
+								if m.Version == "" {
+									m.Version = "0.0.0"
+								}
+								s.ModInfo = append(s.ModInfo, ServerModInfo{
+									Name:             m.Name,
+									Version:          m.Version,
+									RequiredOnClient: m.RequiredOnClient,
+								})
 							}
-							s.ModInfo = append(s.ModInfo, ServerModInfo{
-								Name:             m.Name,
-								Version:          m.Version,
-								RequiredOnClient: m.RequiredOnClient,
-							})
 						}
+					} else {
+						modInfoErr = fmt.Errorf("parse modinfo file: %w", err)
 					}
 				} else {
-					modInfoErr = fmt.Errorf("parse modinfo file: %w", err)
+					modInfoErr = fmt.Errorf("get modinfo file: too large (size %d)", mfHdr.Size)
 				}
+				mf.Close()
 			} else {
-				modInfoErr = fmt.Errorf("get modinfo file: too large (size %d)", mfHdr.Size)
+				modInfoErr = fmt.Errorf("get modinfo file: %w", err)
 			}
-			mf.Close()
 		} else {
-			modInfoErr = fmt.Errorf("get modinfo file: %w", err)
+			if isCreate {
+				modInfoErr = fmt.Errorf("parse multipart form: %w", err)
+			}
+		}
+		if modInfoErr != nil {
+			hlog.FromRequest(r).Warn().
+				Err(err).
+				Msgf("failed to parse modinfo")
 		}
-	} else {
-		modInfoErr = fmt.Errorf("parse multipart form: %w", err)
-	}
-	if modInfoErr != nil {
-		hlog.FromRequest(r).Warn().
-			Err(err).
-			Msgf("failed to parse modinfo")
-	}
-
-	var l ServerListLimit
-	if n := h.MaxServers; n > 0 {
-		l.MaxServers = n
-	} else if n == 0 {
-		l.MaxServers = 1000
-	}
-	if n := h.MaxServersPerIP; n > 0 {
-		l.MaxServersPerIP = n
-	} else if n == 0 {
-		l.MaxServersPerIP = 50
 	}
 
-	nsrv, err := h.ServerList.ServerHybridUpdatePut(nil, &s, l)
+	nsrv, err := h.ServerList.ServerHybridUpdatePut(u, s, l)
 	if err != nil {
+		if errors.Is(err, ErrServerListUpdateWrongIP) {
+			respJSON(w, r, http.StatusForbidden, map[string]any{
+				"success": false,
+				"error":   ErrorCode_UNAUTHORIZED_GAMESERVER,
+				"msg":     ErrorCode_UNAUTHORIZED_GAMESERVER.Messagef("%v", err),
+			})
+			return
+		}
 		if errors.Is(err, ErrServerListDuplicateAuthAddr) {
 			respJSON(w, r, http.StatusForbidden, map[string]any{
 				"success": false,
@@ -238,7 +337,7 @@ func (h *Handler) handleServerAddServer(w http.ResponseWriter, r *http.Request)
 		}
 		hlog.FromRequest(r).Error().
 			Err(err).
-			Msgf("failed to add server to list")
+			Msgf("failed to update server list")
 		respJSON(w, r, http.StatusInternalServerError, map[string]any{
 			"success": false,
 			"error":   ErrorCode_INTERNAL_SERVER_ERROR,
@@ -303,6 +402,7 @@ func (h *Handler) handleServerAddServer(w http.ResponseWriter, r *http.Request)
 				"error":   ErrorCode_NO_GAMESERVER_RESPONSE,
 				"msg":     ErrorCode_NO_GAMESERVER_RESPONSE.Messagef("verification timed out"),
 			})
+			return
 		}
 	}