Exemplo n.º 1
0
Arquivo: record.go Projeto: elos/gaia
// RecordPOST implements gaia's response to a POST request to the '/record/' endpoint.
//
// Assumptions: The user has been authenticated.
//
// Proceedings: Parses the url parameters, and retrieves the kind parameter (required).
// Then it checks whether the payload record's id is declared, generating one if not.
// Finally, it saves or updates the record, returning the record with corresponding status.
//
// Success:
//		* StatusOK with the record as JSON, meaning the record was _updated_
//		* StatusCreated with the record as JSON, meaning the record was _created_
//
// Errors:
//		* InternalServerError: failure to parse the parameters, database connections, json marshalling
//		* BadRequest: no kind param, unrecognized kind
//		* NotFound: unauthorized, record actually doesn't exist
//		* Unauthorized: not authorized to create/update that record, database access denial
func RecordPOST(ctx context.Context, w http.ResponseWriter, r *http.Request, logger services.Logger, db services.DB) {
	l := logger.WithPrefix("RecordPOST: ")

	// Parse the form
	if err := r.ParseForm(); err != nil {
		l.Printf("error parsing form: %s", err)
		http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
		return
	}

	//	l.Printf("%+v", r)

	// Retrieve the kind parameter
	k := r.FormValue(kindParam)
	if k == "" {
		l.Printf("no kind specified")
		http.Error(w, fmt.Sprintf("You must specify a %q parameter", kindParam), http.StatusBadRequest)
		return
	}
	kind := data.Kind(k)

	// Verify it is a recognized kind
	if _, ok := models.Kinds[kind]; !ok {
		http.Error(w, fmt.Sprintf("The kind %q is not recognized", kind), http.StatusBadRequest)
		return
	}

	m := models.ModelFor(kind)

	var requestBody []byte
	var err error

	// Now we must read the body of the request
	defer r.Body.Close() // don't forget to close it
	if requestBody, err = ioutil.ReadAll(r.Body); err != nil {
		l.Printf("error while reading request body: %s", err)
		http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
		return
	}

	// Now we unmarshal that into the record
	if err = json.Unmarshal(requestBody, m); err != nil {
		l.Printf("info: request body:\n%s", string(requestBody))
		l.Printf("error: while unmarshalling request body, %s", err)
		http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
		return
	}

	// Now we can determine whether we are creating a new record
	// or updating an existing one. We expect to be updating...
	creation := false

	// ...unless the id is empty, in which case we are creating
	if m.ID().String() == "" {
		m.SetID(db.NewID()) // Be sure to assign it an ID
		creation = true
	}

	// Retrieve our user
	u, ok := user.FromContext(ctx)
	if !ok {
		l.Print("failed to retrieve user from context")
		http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
		return
	}

	var allowed bool

	// We need to check either [creation] we can create the record or [!creation]
	// we can update the record we are trying to update
	if creation {
		prop, ok := m.(access.Property)
		if !ok {
			l.Printf("tried to create record that isn't property")
			http.Error(w, http.StatusText(http.StatusUnauthorized), http.StatusUnauthorized)
			return
		}

		allowed, err = access.CanCreate(db, u, prop)
	} else {
		allowed, err = access.CanWrite(db, u, m)
	}

	if err != nil {
		l.Printf("access.{CanCreate | CanWrite} error: %s", err)
		switch err {
		// This indicates that no, you have no access
		case data.ErrAccessDenial:
			http.Error(w, http.StatusText(http.StatusUnauthorized), http.StatusUnauthorized)
		// All of these are bad, and considered an internal error
		case data.ErrNotFound:
			fallthrough
		case data.ErrNoConnection:
			fallthrough
		case data.ErrInvalidID:
			fallthrough
		default:
			http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
		}
		return
	} else if !allowed {
		l.Printf("access denied at create/update stage")
		http.Error(w, http.StatusText(http.StatusUnauthorized), http.StatusUnauthorized)
		return
	}

	// If we have made it this far, it only remains to commit the record
	if err = db.Save(m); err != nil {
		l.Printf("error saving record: %s", err)
		switch err {
		case data.ErrAccessDenial:
			http.Error(w, http.StatusText(http.StatusUnauthorized), http.StatusUnauthorized)
		// These are all equally distressing
		case data.ErrNotFound: // TODO shouldn't a not found not be fing impossible for a Save?
			fallthrough
		case data.ErrNoConnection:
			fallthrough
		case data.ErrInvalidID:
		default:
			http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
		}
		return
	}

	// Now we shall write our response
	bytes, err := json.MarshalIndent(m, "", "    ")
	if err != nil {
		l.Printf("error marshalling model: %s", err)
		http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
		return
	}

	if creation {
		w.WriteHeader(http.StatusCreated)
	} else {
		w.WriteHeader(http.StatusOK)
	}

	w.Header().Set("Content-Type", "application/json")
	w.Write(bytes)
}
Exemplo n.º 2
0
Arquivo: record.go Projeto: elos/gaia
// RecordDelete implements gaia's response to a DELETE request to the '/record/' endpoint.
//
// Assumptions: The user has been authenticated.
//
// Proceedings: Parses the url parameters, and retrieves the kind and id parameters (both required).
// Then checks for authorization to delete, carries it out if allowed.
//
// Success:
//		* StatusNoContent indicating a succesful deletion
//
// Errors:
//		* InternalServerError: failure to parse the parameters, database connections, json marshalling
//		* BadRequest: no kind param, unrecognized kind, no id param, invalid id param
//		* NotFound: unauthorized, record actually doesn't exist
//		* Unauthorized: not authorized to delete that record, database access denial
func RecordDELETE(ctx context.Context, w http.ResponseWriter, r *http.Request, logger services.Logger, db services.DB) {
	l := logger.WithPrefix("RecordDELETE: ")

	// Parse the form
	if err := r.ParseForm(); err != nil {
		l.Printf("error parsing form: %s", err)
		http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
		return
	}

	// Retrieve the kind parameter
	k := r.FormValue(kindParam)
	if k == "" {
		l.Printf("no kind specified")
		http.Error(w, fmt.Sprintf("You must specify a %q parameter", kindParam), http.StatusBadRequest)
		return
	}
	kind := data.Kind(k)

	// Retrieve the id parameter
	i := r.FormValue(idParam)
	if i == "" {
		l.Printf("no id specified")
		http.Error(w, fmt.Sprintf("You must specify a %q parameter", idParam), http.StatusBadRequest)
		return
	}

	// Verify the kind is recognized
	_, ok := models.Kinds[kind]
	if !ok {
		l.Printf("unrecognized kind: %q", kind)
		http.Error(w, fmt.Sprintf("The kind %q is not recognized", kind), http.StatusBadRequest)
		return
	}

	// Verify the id is valid
	id, err := db.ParseID(i)
	if err != nil {
		l.Printf("invalid id: %q, error: %s", i, err)
		http.Error(w, fmt.Sprintf("The id %q is invalid", i), http.StatusBadRequest)
		return
	}

	// Get the record, so that we can decide whether we have permission to delete it
	m := models.ModelFor(kind)
	m.SetID(id)
	if err = db.PopulateByID(m); err != nil {
		l.Printf("db.PopulateByID error: %s", err)
		switch err {
		case data.ErrAccessDenial:
			fallthrough // don't leak information (were we denied access, this record doesn't exist)
		case data.ErrNotFound:
			http.Error(w, http.StatusText(http.StatusNotFound), http.StatusNotFound)
		case data.ErrNoConnection:
			fallthrough
		case data.ErrInvalidID:
			fallthrough
		default:
			http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
		}
		return
	}

	// Retrieve the user we are authenticated as
	u, ok := user.FromContext(ctx)
	if !ok {
		l.Print("faild to retrieve user from context")
		http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
		return
	}

	// check for authorization
	if allowed, err := access.CanDelete(db, u, m); err != nil {
		// TODO(nclandolfi) standardize this with the POST and GET where we handle the possible errors
		l.Printf("RecordDELETE Error: %s", err)
		http.Error(w, "database error", http.StatusInternalServerError)
		return
	} else if !allowed {
		// in order to not leak information, we treat this as a not found
		http.Error(w, http.StatusText(http.StatusNotFound), http.StatusNotFound)
		return
	}

	if err := db.Delete(m); err != nil {
		switch err {
		case data.ErrAccessDenial:
			http.Error(w, http.StatusText(http.StatusNotFound), http.StatusNotFound) // don't leak information
		case data.ErrNotFound:
			// this shouldn't happen unless it was deleted by another process
			// in between when we populated the record by id, in which case it was successful
			goto successfulDelete
			// all of these errors, we can't guarantee deletion
		case data.ErrNoConnection:
			fallthrough
		case data.ErrInvalidID:
			http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
		default:
			l.Printf("RecordDELETE Error: %s", err)
			http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
		}
		return
	}

successfulDelete:
	w.WriteHeader(http.StatusNoContent)
}
Exemplo n.º 3
0
Arquivo: record.go Projeto: elos/gaia
// RecordGET implements gaia's response to a GET request to the '/record/' endpoint.
//
// Assumptions: The user has been authenticated.
//
// Proceedings: Parses the url parameters, retrieving the kind and id parameters (both required).
// Then it loads that record, checks if the user is allowed to access it, if so it returns the model as JSON.
//
// Success:
//		* StatusOK with the record as JSON
//
// Errors:
//		* InternalServerError: failure to parse the parameters, database connections, json marshalling
//		* BadRequest: no kind param, no id param, unrecognized kind, invalid id
//		* NotFound: unauthorized, record actually doesn't exist
func RecordGET(ctx context.Context, w http.ResponseWriter, r *http.Request, logger services.Logger, db services.DB) {
	l := logger.WithPrefix("RecordGet: ")

	// Parse the form value
	if err := r.ParseForm(); err != nil {
		l.Printf("error parsing form: %s", err)
		http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
		return
	}

	// Secure the kind parameter's existence, and superficial validity (i.e., non-empty)
	k := r.FormValue(kindParam)
	if k == "" {
		l.Printf("no kind parameter")
		http.Error(w, fmt.Sprintf("You must specify a '%s' parameter", kindParam), http.StatusBadRequest)
		return
	}
	kind := data.Kind(k)

	// Secure the id parameter's existence, and superficial validity (i.e., non-empty)
	i := r.FormValue(idParam)
	if i == "" {
		l.Printf("no id parameter")
		http.Error(w, fmt.Sprintf("You must specify a '%s' parameter", idParam), http.StatusBadRequest)
		return
	}

	// Ensure the kind is recognized
	if _, ok := models.Kinds[kind]; !ok {
		l.Printf("unrecognized kind: %q", kind)
		http.Error(w, fmt.Sprintf("The kind %q is not recognized", kind), http.StatusBadRequest)
		return
	}

	// Ensure the id is valid
	id, err := db.ParseID(i)
	if err != nil {
		l.Printf("unrecognized id: %q, err: %s", i, err)
		http.Error(w, fmt.Sprintf("The id %q is invalid", i), http.StatusBadRequest)
		return
	}

	m := models.ModelFor(kind)
	m.SetID(id)

	if err := db.PopulateByID(m); err != nil {
		switch err {
		// ErrAccessDenial and ErrNotFound are "normal" courses, in the sense that they
		// may be expected in normal usage.
		case data.ErrAccessDenial:
			fallthrough // don't leak information, make it look like a 404
		case data.ErrNotFound:
			// This is, by far, the most common error case here.
			http.Error(w, http.StatusText(http.StatusNotFound), http.StatusNotFound)
		// ErrNoConnection, ErrInvalidID and the under-determined errors are all non-normal cases
		case data.ErrNoConnection:
			fallthrough
		case data.ErrInvalidID:
			fallthrough
		default:
			http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
		}
		l.Printf("db.PopulateByID error: %s", err)
		return // regardless of what the error was, we are bailing
	}

	// Retrieve the user this request was authenticated as
	u, ok := user.FromContext(ctx)
	if !ok { // This is certainly an issue, and should _never_ happen
		l.Print("failed to retrieve user from context")
		http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
		return
	}

	// Now we impose the system access control, beyond the database access control
	// TODO: limit the domain of errors CanRead returns
	if allowed, err := access.CanRead(db, u, m); err != nil {
		switch err {
		// Again, though odd, both of these are arguably expected
		case data.ErrAccessDenial:
			fallthrough // don't leak information
		case data.ErrNotFound:
			http.Error(w, http.StatusText(http.StatusNotFound), http.StatusNotFound)
		// These are not-expected
		case data.ErrNoConnection:
			fallthrough
		case data.ErrInvalidID:
			fallthrough
		default:
			http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
		}
		l.Printf("access.CanRead error: %s", err)
		return
	} else if !allowed {
		// If you can't read the record you are asking for,
		// it "does not exist" as far as you are concerned
		l.Print("access denied")
		http.Error(w, http.StatusText(http.StatusNotFound), http.StatusNotFound)
		return
	}

	bytes, err := json.MarshalIndent(m, "", "	")
	if err != nil {
		l.Printf("error while marshalling json %s", err)
		http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
		return
	}

	w.WriteHeader(http.StatusOK)
	w.Header().Set("Content-Type", "application/json")
	w.Write(bytes)
}