{"record":{"id":"5941f76ca2b9c6d4","repo":"caddyserver/caddy","slug":"parsing-cidr-expression-v","errorCode":null,"errorMessage":"parsing CIDR expression: %v","messagePattern":"parsing CIDR expression: (.+?)","errorType":"validation","errorClass":null,"httpStatus":null,"severity":"error","filePath":"modules/caddytls/matchers.go","lineNumber":376,"sourceCode":"\t\tipStr = remoteAddr // weird; maybe no port?\n\t}\n\tipAddr, err := netip.ParseAddr(ipStr)\n\tif err != nil {\n\t\tif c := m.logger.Check(zapcore.ErrorLevel, \"invalid client IP address\"); c != nil {\n\t\t\tc.Write(zap.String(\"ip\", ipStr))\n\t\t}\n\t\treturn false\n\t}\n\treturn (len(m.cidrs) == 0 || m.matches(ipAddr, m.cidrs)) &&\n\t\t(len(m.notCidrs) == 0 || !m.matches(ipAddr, m.notCidrs))\n}\n\nfunc (MatchRemoteIP) parseIPRange(str string) ([]netip.Prefix, error) {\n\tvar cidrs []netip.Prefix\n\tif strings.Contains(str, \"/\") {\n\t\tipNet, err := netip.ParsePrefix(str)\n\t\tif err != nil {\n\t\t\treturn nil, fmt.Errorf(\"parsing CIDR expression: %v\", err)\n\t\t}\n\t\tcidrs = append(cidrs, ipNet)\n\t} else {\n\t\tipAddr, err := netip.ParseAddr(str)\n\t\tif err != nil {\n\t\t\treturn nil, fmt.Errorf(\"invalid IP address: '%s': %v\", str, err)\n\t\t}\n\t\tip := netip.PrefixFrom(ipAddr, ipAddr.BitLen())\n\t\tcidrs = append(cidrs, ip)\n\t}\n\treturn cidrs, nil\n}\n\nfunc (MatchRemoteIP) matches(ip netip.Addr, ranges []netip.Prefix) bool {\n\treturn slices.ContainsFunc(ranges, func(prefix netip.Prefix) bool {\n\t\treturn prefix.Contains(ip)\n\t})\n}","sourceCodeStart":358,"sourceCodeEnd":394,"githubUrl":"https://github.com/caddyserver/caddy/blob/50e54ee279aa1e504fe218ca49ab6ae16c100410/modules/caddytls/matchers.go#L358-L394","documentation":"Error \"parsing CIDR expression: %v\" thrown in caddyserver/caddy.","triggerScenarios":"Thrown at modules/caddytls/matchers.go:376 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":["Fix the CIDR expression, e.g. '192.168.0.0/16'; the wrapped error explains the parse failure."],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"50e54ee279aa1e504fe218ca49ab6ae16c100410","analyzedAt":"2026-08-15T09:20:21.641Z","schemaVersion":2},"datasetVersion":"2026-08-15T22:17:37.221Z"}