normalizeAndGetContentLength() — netty Function Reference

Architecture documentation for the normalizeAndGetContentLength() function in HttpUtil.java from the netty codebase.

Function java ProtocolCodecs HTTP

Entity Profile

ProtocolCodecs→ HTTP→ normalizeAndGetContentLength() — netty Function Reference

Dependency Diagram

graph TD
  1fb8b265_a09b_dd75_535f_9dbbfa1346b0["normalizeAndGetContentLength()"]
  0b1cc975_2772_c898_b055_3991b4e80dba["HttpUtil"]
  1fb8b265_a09b_dd75_535f_9dbbfa1346b0 -->|defined in| 0b1cc975_2772_c898_b055_3991b4e80dba
  style 1fb8b265_a09b_dd75_535f_9dbbfa1346b0 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

codec-http/src/main/java/io/netty/handler/codec/http/HttpUtil.java lines 611–674

    public static long normalizeAndGetContentLength(
            List<? extends CharSequence> contentLengthFields, boolean isHttp10OrEarlier,
            boolean allowDuplicateContentLengths) {
        if (contentLengthFields.isEmpty()) {
            return -1;
        }

        // Guard against multiple Content-Length headers as stated in
        // https://tools.ietf.org/html/rfc7230#section-3.3.2:
        //
        // If a message is received that has multiple Content-Length header
        //   fields with field-values consisting of the same decimal value, or a
        //   single Content-Length header field with a field value containing a
        //   list of identical decimal values (e.g., "Content-Length: 42, 42"),
        //   indicating that duplicate Content-Length header fields have been
        //   generated or combined by an upstream message processor, then the
        //   recipient MUST either reject the message as invalid or replace the
        //   duplicated field-values with a single valid Content-Length field
        //   containing that decimal value prior to determining the message body
        //   length or forwarding the message.
        String firstField = contentLengthFields.get(0).toString();
        boolean multipleContentLengths =
                contentLengthFields.size() > 1 || firstField.indexOf(COMMA) >= 0;

        if (multipleContentLengths && !isHttp10OrEarlier) {
            if (allowDuplicateContentLengths) {
                // Find and enforce that all Content-Length values are the same
                String firstValue = null;
                for (CharSequence field : contentLengthFields) {
                    String[] tokens = field.toString().split(COMMA_STRING, -1);
                    for (String token : tokens) {
                        String trimmed = token.trim();
                        if (firstValue == null) {
                            firstValue = trimmed;
                        } else if (!trimmed.equals(firstValue)) {
                            throw new IllegalArgumentException(
                                    "Multiple Content-Length values found: " + contentLengthFields);
                        }
                    }
                }
                // Replace the duplicated field-values with a single valid Content-Length field
                firstField = firstValue;
            } else {
                // Reject the message as invalid
                throw new IllegalArgumentException(
                        "Multiple Content-Length values found: " + contentLengthFields);
            }
        }
        // Ensure we not allow sign as part of the content-length:
        // See https://github.com/squid-cache/squid/security/advisories/GHSA-qf3v-rc95-96j5
        if (firstField.isEmpty() || !Character.isDigit(firstField.charAt(0))) {
            // Reject the message as invalid
            throw new IllegalArgumentException(
                    "Content-Length value is not a number: " + firstField);
        }
        try {
            final long value = Long.parseLong(firstField);
            return checkPositiveOrZero(value, "Content-Length value");
        } catch (NumberFormatException e) {
            // Reject the message as invalid
            throw new IllegalArgumentException(
                    "Content-Length value is not a number: " + firstField, e);
        }
    }