XTLS/Xray-core · error

syntax error

Error message

syntax error

What it means

parseGeoIPRule splits the rule on ':' via strings.Cut; if there is no ':' at all, ok is false and this error is raised. It means the caller routed a rule into the GeoIP branch (prefix > 0 or ext:/geosite-style handling) but the string lacks the required FILE:CODE shape.

Source

Thrown at common/geodata/rule_parser.go:62

		ipRules = append(ipRules, &IPRule{Value: rule})
	}

	return ipRules, nil
}

func cutReversePrefix(s string) (string, bool) {
	reverse := false
	for strings.HasPrefix(s, "!") {
		s = s[1:]
		reverse = !reverse
	}
	return s, reverse
}

func parseGeoIPRule(rule string, reverse bool) (*IPRule_Geoip, error) {
	file, code, ok := strings.Cut(rule, ":")
	if !ok {
		return nil, errors.New("syntax error")
	}

	if file == "" {
		return nil, errors.New("empty file")
	}

	code, codeReverse := cutReversePrefix(code)
	reverse = reverse != codeReverse
	if code == "" {
		return nil, errors.New("empty code")
	}
	code = strings.ToUpper(code)

	if err := checkFile(file, code); err != nil {
		return nil, err
	}

	return &IPRule_Geoip{

View on GitHub (pinned to 7d214f8b09)

Solutions

1. Rewrite the rule as FILE:CODE, e.g. "ext:geoip.dat:cn" or "geoip:cn".
2. For plain CIDR/IP rules (no file), drop the prefix so parseCustomIPRule handles them.

Example fix

// before
"ip": ["ext:geoip.dat"]

// after
"ip": ["ext:geoip.dat:cn"]

if strings.HasPrefix(r, "ext:") || strings.HasPrefix(r, "geoip") {
    if !strings.Contains(r, ":") || strings.HasSuffix(r, ":") { return fmt.Errorf("rule %q must be FILE:CODE", r) }
}

When it happens

Trigger: A rule string beginning with a recognized prefix but containing no colon, e.g. "ext:geoip.dat" is fine but a custom path like "ext" or "geoip-only-cn" (no ':') reaching this parser.

Common situations: Forgetting the country code segment: "ext:geoip.dat" instead of "ext:geoip.dat:cn"; omitting code after "geosite:" style aliasing when the alias is missing.

Related errors

• empty file
• empty code
• illegal ip rule:
• empty domain rule list
• unknown domain type:

AI-assisted analysis of XTLS/Xray-core@7d214f8b09 (2026-08-15). Data as JSON: /api/errors/218263fd45ba7e91. Report an issue: GitHub.