{"record":{"id":"e6c7e332ed9c25bf","repo":"owasp-amass/amass","slug":"error-reading-the-response-from-the-whois-server","errorCode":null,"errorMessage":"error reading the response from the WHOIS server: %v","messagePattern":"error reading the response from the WHOIS server: (.+?)","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"engine/plugins/whois/bgptools/plugin.go","lineNumber":152,"sourceCode":"\n\t_ = bt.rlimit.Wait(ctx)\n\tctx, cancel := context.WithTimeout(ctx, 10*time.Second)\n\tdefer cancel()\n\n\tconn, err := dial(ctx, \"tcp\", addr)\n\tif err != nil {\n\t\treturn nil, fmt.Errorf(\"failed to establish a connection with the WHOIS server: %v\", err)\n\t}\n\tdefer func() { _ = conn.Close() }()\n\n\tn, err := io.WriteString(conn, fmt.Sprintf(\"begin\\n%s\\nend\", ipstr))\n\tif err != nil || n == 0 {\n\t\treturn nil, fmt.Errorf(\"failed to send the request to the WHOIS server: %v\", err)\n\t}\n\n\tdata, err := io.ReadAll(conn)\n\tif err != nil {\n\t\treturn nil, fmt.Errorf(\"error reading the response from the WHOIS server: %v\", err)\n\t}\n\n\trecord := strings.Split(string(data), \"|\")\n\t// Ensure the record contains the necessary details (AutonomousSystem and Netblock)\n\tif len(record) < 7 {\n\t\treturn nil, errors.New(\"received insufficient data from the WHOIS server\")\n\t}\n\n\tvar r bgpToolsRecord\n\tfor i, f := range record {\n\t\tfield := strings.TrimSpace(f)\n\n\t\tswitch i {\n\t\tcase 0:\n\t\t\tnum, err := strconv.Atoi(field)\n\t\t\tif err != nil {\n\t\t\t\treturn nil, err\n\t\t\t}","sourceCodeStart":134,"sourceCodeEnd":170,"githubUrl":"https://github.com/owasp-amass/amass/blob/79299dce87b0085db0f2f4ef3e9c52cccb49f514/engine/plugins/whois/bgptools/plugin.go#L134-L170","documentation":"The bgptools WHOIS plugin wraps read errors from io.ReadAll when receiving the WHOIS response over the TCP connection. The connection was established and the request written, but reading the reply failed — typically a timeout, connection reset, or premature close while the response was in flight.","triggerScenarios":"Calling whois(ctx, ipstr) where io.ReadAll(conn) returns an error after the request was written: the 10s context/deadline expired before the server finished responding, the connection was reset mid-response, or the peer closed the socket in an error state.","commonSituations":"Slow or overloaded bgp.tools service exceeding the 10s deadline; rate limiting causing truncated/reset responses; flaky mobile/VPN networks dropping long-lived connections; firewalls killing connections that stay open waiting for data.","solutions":["Inspect the wrapped cause — timeout vs connection reset points to different fixes","Increase or verify the 10s timeout if responses are consistently slow on this network","Retry with backoff; transient resets/timeouts often succeed on a second attempt","Check for rate limiting from bgp.tools and slow down query volume","Ensure no middleboxes (VPN/proxy) are resetting long-lived TCP connections"],"exampleFix":"// before\nctx, cancel := context.WithTimeout(ctx, 10*time.Second)\n// after\nctx, cancel := context.WithTimeout(ctx, 30*time.Second) // allow for slow WHOIS responses","handlingStrategy":"retry","validationCode":"// ensure generous deadline before reading\nctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)\ndefer cancel()","typeGuard":null,"tryCatchPattern":"if err != nil {\n    var netErr net.Error\n    if errors.As(err, &netErr) && netErr.Timeout() {\n        // increase timeout and/or retry\n    }\n    // otherwise treat as transient reset and retry with backoff\n}","preventionTips":["Allow a timeout larger than the worst-case WHOIS response time","Retry transient read failures with exponential backoff","Avoid running bulk queries over unstable links (mobile/VPN); prefer wired/stable networks","Monitor for rate limiting and throttle query volume"],"tags":["network","tcp","whois","timeout","io"],"backgroundTag":"request-timeout","analyzedSha":"79299dce87b0085db0f2f4ef3e9c52cccb49f514","analyzedAt":"2026-09-06T08:22:48.198Z","contentChangedAt":"2026-09-06T08:22:48.198Z","schemaVersion":2},"datasetVersion":"2026-09-14T05:17:10.506Z"}