XTLS/Xray-core · error

Invalid PacketsFrom

Error message

Invalid PacketsFrom

What it means

Thrown while parsing the freedom outbound's fragment 'packets' setting when it is neither "tlshello" nor empty: the value is treated as a numeric range string (e.g. "1-3") and ParseRangeString fails. The underlying parse error is chained via .Base(err), so the full message shows why the range is malformed.

Source

Thrown at infra/conf/freedom.go:109

	}

	if c.Fragment != nil {
		config.Fragment = new(freedom.Fragment)

		switch strings.ToLower(c.Fragment.Packets) {
		case "tlshello":
			// TLS Hello Fragmentation (into multiple handshake messages)
			config.Fragment.PacketsFrom = 0
			config.Fragment.PacketsTo = 1
		case "":
			// TCP Segmentation (all packets)
			config.Fragment.PacketsFrom = 0
			config.Fragment.PacketsTo = 0
		default:
			// TCP Segmentation (range)
			from, to, err := ParseRangeString(c.Fragment.Packets)
			if err != nil {
				return nil, errors.New("Invalid PacketsFrom").Base(err)
			}
			config.Fragment.PacketsFrom = uint64(from)
			config.Fragment.PacketsTo = uint64(to)
			if config.Fragment.PacketsFrom == 0 {
				return nil, errors.New("PacketsFrom can't be 0")
			}
		}

		{
			if c.Fragment.Length == nil {
				return nil, errors.New("Length can't be empty")
			}
			config.Fragment.LengthMin = uint64(c.Fragment.Length.From)
			config.Fragment.LengthMax = uint64(c.Fragment.Length.To)
			if config.Fragment.LengthMin == 0 {
				return nil, errors.New("LengthMin can't be 0")
			}
		}

View on GitHub (pinned to 7d214f8b09)

Solutions

1. Write the packets range as "from-to", e.g. "1-3" for TCP segmentation of packets 1 through 3.
2. Use "tlshello" for TLS-hello fragmentation or omit/empty for all packets.
3. Read the chained base error to see the exact parse failure reason.

Example fix

// before
"packets": "1:3"

// after
"packets": "1-3"

if p := fragment.Packets; p != "" && p != "tlshello" {
    if _, _, err := ParseRangeString(p); err != nil {
        return fmt.Errorf("fragment.packets %q must be 'tlshello', '', or 'N-M': %w", p, err)
    }
}

When it happens

Trigger: "fragment": {"packets": "1:3"} (colon instead of dash), "packets": "1-", "packets": "abc" — any value that ParseRangeString cannot parse as a from-to range. The "tlshello" and "" special cases bypass this path.

Common situations: Using wrong range separators; copying fragment examples from other projects that use 'x:y' notation; stray whitespace or unicode dashes.

Related errors

• unsupported domain strategy: {}
• PacketsFrom can't be 0
• Length can't be empty
• LengthMin can't be 0
• Interval can't be empty

AI-assisted analysis of XTLS/Xray-core@7d214f8b09 (2026-08-15). Data as JSON: /api/errors/8b6ea7861890f4cb. Report an issue: GitHub.