Restrict permission check on repositories and fix some problems (#5314)

* fix units permission problems

* fix some bugs and merge LoadUnits to repoAssignment

* refactor permission struct and add some copyright heads

* remove unused codes

* fix routes units check

* improve permission check

* add unit tests for permission

* fix typo

* fix tests

* fix some routes

* fix api permission check

* improve permission check

* fix some permission check

* fix tests

* fix tests

* improve some permission check

* fix some permission check

* refactor AccessLevel

* fix bug

* fix tests

* fix tests

* fix tests

* fix AccessLevel

* rename CanAccess

* fix tests

* fix comment

* fix bug

* add missing unit for test repos

* fix bug

* rename some functions

* fix routes check

modules/context/permission.go

@@ -0,0 +1,64 @@
+// Copyright 2018 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package context
+
+import (
+	"code.gitea.io/gitea/models"
+	macaron "gopkg.in/macaron.v1"
+)
+
+// RequireRepoAdmin returns a macaron middleware for requiring repository admin permission
+func RequireRepoAdmin() macaron.Handler {
+	return func(ctx *Context) {
+		if !ctx.IsSigned || !ctx.Repo.IsAdmin() {
+			ctx.NotFound(ctx.Req.RequestURI, nil)
+			return
+		}
+	}
+}
+
+// RequireRepoWriter returns a macaron middleware for requiring repository write to the specify unitType
+func RequireRepoWriter(unitType models.UnitType) macaron.Handler {
+	return func(ctx *Context) {
+		if !ctx.Repo.CanWrite(unitType) {
+			ctx.NotFound(ctx.Req.RequestURI, nil)
+			return
+		}
+	}
+}
+
+// RequireRepoWriterOr returns a macaron middleware for requiring repository write to one of the unit permission
+func RequireRepoWriterOr(unitTypes ...models.UnitType) macaron.Handler {
+	return func(ctx *Context) {
+		for _, unitType := range unitTypes {
+			if ctx.Repo.CanWrite(unitType) {
+				return
+			}
+		}
+		ctx.NotFound(ctx.Req.RequestURI, nil)
+	}
+}
+
+// RequireRepoReader returns a macaron middleware for requiring repository read to the specify unitType
+func RequireRepoReader(unitType models.UnitType) macaron.Handler {
+	return func(ctx *Context) {
+		if !ctx.Repo.CanRead(unitType) {
+			ctx.NotFound(ctx.Req.RequestURI, nil)
+			return
+		}
+	}
+}
+
+// RequireRepoReaderOr returns a macaron middleware for requiring repository write to one of the unit permission
+func RequireRepoReaderOr(unitTypes ...models.UnitType) macaron.Handler {
+	return func(ctx *Context) {
+		for _, unitType := range unitTypes {
+			if ctx.Repo.CanRead(unitType) {
+				return
+			}
+		}
+		ctx.NotFound(ctx.Req.RequestURI, nil)
+	}
+}