{"record":{"id":"cf068724f5057058","repo":"XTLS/Xray-core","slug":"padding-turn-d-has-an-invalid-start-delay-w","errorCode":null,"errorMessage":"padding turn %d has an invalid start delay: %w","messagePattern":"padding turn (.+?) has an invalid start delay: %w","errorType":"validation","errorClass":null,"httpStatus":null,"severity":"error","filePath":"transport/internet/finalmask/xmc/padding.go","lineNumber":89,"sourceCode":"}\n\nfunc validatePaddingSchedule(schedule []paddingTurn, firstTurnPrefixLength int) error {\n\tif len(schedule) == 0 {\n\t\treturn fmt.Errorf(\"empty padding schedule\")\n\t}\n\tif firstTurnPrefixLength < 0 {\n\t\treturn fmt.Errorf(\"negative first turn prefix length: %d\", firstTurnPrefixLength)\n\t}\n\tif firstTurnPrefixLength > 0 && schedule[0].direction != paddingClientToServer {\n\t\treturn fmt.Errorf(\"first prefixed padding turn is not client-to-server\")\n\t}\n\n\tfor i, turn := range schedule {\n\t\tif turn.direction != paddingClientToServer && turn.direction != paddingServerToClient {\n\t\t\treturn fmt.Errorf(\"padding turn %d has invalid direction: %d\", i, turn.direction)\n\t\t}\n\t\tif err := validatePaddingDelayRange(turn.startDelay); err != nil {\n\t\t\treturn fmt.Errorf(\"padding turn %d has an invalid start delay: %w\", i, err)\n\t\t}\n\t\tif err := validatePaddingDelayRange(turn.chunkDelay); err != nil {\n\t\t\treturn fmt.Errorf(\"padding turn %d has an invalid chunk delay: %w\", i, err)\n\t\t}\n\t\tif turn.writeChunkMinLength < 0 || turn.writeChunkLength < turn.writeChunkMinLength || turn.writeChunkLength > maxPaddingChunkLength {\n\t\t\treturn fmt.Errorf(\"padding turn %d has an invalid write chunk range: %d-%d\", i, turn.writeChunkMinLength, turn.writeChunkLength)\n\t\t}\n\t\tif len(turn.variants) > 0 && turn.writeChunkLength != 0 {\n\t\t\treturn fmt.Errorf(\"padding turn %d combines variants with generated write chunks\", i)\n\t\t}\n\n\t\tminLength, maxLength, err := paddingTurnBounds(turn)\n\t\tif err != nil {\n\t\t\treturn fmt.Errorf(\"padding turn %d: %w\", i, err)\n\t\t}\n\t\thasSendRange := turn.sendMinLength != 0 || turn.sendMaxLength != 0\n\t\tif hasSendRange {\n\t\t\tif len(turn.variants) > 0 {","sourceCodeStart":71,"sourceCodeEnd":107,"githubUrl":"https://github.com/XTLS/Xray-core/blob/7d214f8b094f75322fa3990f8aadad1c912f24f5/transport/internet/finalmask/xmc/padding.go#L71-L107","documentation":"validatePaddingSchedule rejected turn i's startDelay because its min is negative or max < min (via validatePaddingDelayRange). Start delays pace how long the endpoint waits before beginning a padding turn; they must satisfy 0 <= min <= max.","triggerScenarios":"A schedule turn with startDelay.min negative (e.g. parsed from a signed config value) or with the min/max fields swapped so max < min.","commonSituations":"Forks exposing delay ranges in config with signed ints; unit tests with placeholder negative durations; refactors confusing time.Duration sign conventions.","solutions":["Correct the range so 0 <= startDelay.min <= startDelay.max","If delays come from user config, clamp or reject negative values at parse time","Use time.Duration literals (e.g. 10*time.Millisecond) instead of raw integers"],"exampleFix":"// before\nstartDelay: paddingDelayRange{min: 50 * time.Millisecond, max: 10 * time.Millisecond}\n\n// after\nstartDelay: paddingDelayRange{min: 10 * time.Millisecond, max: 50 * time.Millisecond}","handlingStrategy":"validation","validationCode":"func validDelayRange(d paddingDelayRange) bool { return d.min >= 0 && d.max >= d.min }","typeGuard":null,"tryCatchPattern":null,"preventionTips":["Use time.Duration literals, not raw ints","Clamp externally supplied delays to >= 0 at parse time"],"tags":["go","padding","validation","timing"],"backgroundTag":null,"analyzedSha":"7d214f8b094f75322fa3990f8aadad1c912f24f5","analyzedAt":"2026-08-15T14:26:24.325Z","schemaVersion":2},"datasetVersion":"2026-08-15T17:31:12.345Z"}