feat(core): HTTP/2 Phase 0 — groundwork (limits, error model, decision log)
Establishes the package layout, limits/error model and decision-log convention that every later HTTP/2 phase depends on, per flash/docs/http2/IMPLEMENTATION-PLAN.md Phase 0. - dev.relism.flash.h2: package-info (architecture overview), Http2ErrorCode (the 14 RFC 9113 §7 codes with precomputed 4-byte wire encodings), Http2Exception (connection error -> GOAWAY) and Http2StreamException (stream error -> RST_STREAM), neither extending IOException, both with stack-trace capture disabled on the hot rejection path. - Http2Limits: every bound Phase 0 requires (concurrent streams, frame size, header list size, CONTINUATION/reset/settings/ping rate bounds, flow-control windows, HPACK table size/string length, assembly and idle timeouts), each documented with the attack or RFC clause it addresses. - dev.relism.flash.http.Http1Limits: the h1 bounds needed by EX-03 (strict Content-Length) and EX-08 (header count/size limits). - flash/docs/http2/DECISIONS.md seeded with DEC-01..DEC-11 (the ten decisions implied by the plan itself, plus DEC-11 recording that commits keep scope `core` rather than adding `h2` to AGENTS.md). - flash/docs/http2/IMPLEMENTATION-PLAN.md: added the Progress Ledger (tracks phase status across sessions) and checked off Phase 0's DoD. 19 new tests, full flash module suite green (226/226). Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
This commit is contained in:
Zakaria El Orche
co-authored by
Claude Sonnet 5
Claude Sonnet 5
parent
8f1f30b973
commit
db6e4a4d0c
@@ -0,0 +1,95 @@
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package dev.relism.flash.h2;
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/**
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* The 14 HTTP/2 error codes defined by RFC 9113 §7.
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*
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* <p>Each constant carries its 4-byte big-endian wire encoding, precomputed once at class
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* load (RFC 9113 §6.4 {@code RST_STREAM} and §6.8 {@code GOAWAY} both carry the error code as
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* a raw 32-bit field — there is no framing around it to build). Callers write
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* {@link #bytes()} directly into a frame payload; nothing is formatted at request time (R4).
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*
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* <p>{@code Http2ErrorCode} is used to reject a peer <em>and</em> to interpret what a peer
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* sends us: {@link #fromCode(int)} decodes a received 32-bit value. RFC 9113 does not reserve
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* unknown codes for future use in a way that requires us to accept them silently as one of the
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* 14 — an endpoint that receives an error code it does not recognise treats it as
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* {@code INTERNAL_ERROR}-equivalent for logging purposes; {@link #fromCode(int)} returns
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* {@code null} for that case and callers log the raw integer rather than guessing a mapping.
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*/
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public enum Http2ErrorCode {
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/** Graceful shutdown or successful completion; not an error. RFC 9113 §7. */
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NO_ERROR(0x00),
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/** The peer violated the protocol in a way not covered by a more specific code. */
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PROTOCOL_ERROR(0x01),
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/** Unexpected internal condition on our side (e.g. an uncaught exception on the demux loop). */
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INTERNAL_ERROR(0x02),
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/** A flow-control window was violated: overflow past 2^31-1, or a peer exceeded its window. */
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FLOW_CONTROL_ERROR(0x03),
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/** The peer did not acknowledge our SETTINGS within {@code SETTINGS_ACK_TIMEOUT_MS}. */
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SETTINGS_TIMEOUT(0x04),
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/** A frame was received for a stream that is already closed. */
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STREAM_CLOSED(0x05),
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/** A frame's length did not match what its type requires (RFC 9113 §4.2, per-type rules). */
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FRAME_SIZE_ERROR(0x06),
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/** The stream was refused before any processing; safe for the client to retry elsewhere. */
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REFUSED_STREAM(0x07),
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/** Used by clients to cancel a stream; Flash never sends it, only receives it. */
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CANCEL(0x08),
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/** An HPACK decoding failure. Terminates the connection because the dynamic table state is lost. */
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COMPRESSION_ERROR(0x09),
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/** A CONNECT-tunnelled stream failed. */
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CONNECT_ERROR(0x0a),
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/** The peer is generating excessive load (rate-limit rejection: Rapid Reset, PING/SETTINGS floods). */
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ENHANCE_YOUR_CALM(0x0b),
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/** The negotiated TLS parameters fall below RFC 9113 §9.2's minimum security requirements. */
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INADEQUATE_SECURITY(0x0c),
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/** Defined by RFC 9113 for HTTP/1.1-only resources; Flash serves everything over h2, so unused. */
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HTTP_1_1_REQUIRED(0x0d);
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private static final Http2ErrorCode[] BY_CODE = new Http2ErrorCode[values().length];
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static {
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for (Http2ErrorCode c : values()) {
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BY_CODE[c.code] = c;
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}
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}
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private final int code;
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private final byte[] bytes;
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Http2ErrorCode(int code) {
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this.code = code;
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this.bytes = new byte[]{
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(byte) (code >>> 24),
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(byte) (code >>> 16),
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(byte) (code >>> 8),
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(byte) code
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};
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}
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/** The numeric error code as it appears on the wire. */
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public int code() {
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return code;
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}
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/**
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* The pre-encoded 4-byte big-endian wire form. Safe to write directly into a
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* {@code RST_STREAM} or {@code GOAWAY} payload with a single {@code System.arraycopy} —
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* never allocated or formatted per use.
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*/
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public byte[] bytes() {
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return bytes;
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}
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/**
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* Decodes a 32-bit error code received from a peer. Returns {@code null} for a value
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* outside the 14 defined codes; the caller should log the raw integer rather than assume
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* a mapping, since RFC 9113 permits future extension codes we do not yet know about.
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*/
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public static Http2ErrorCode fromCode(int code) {
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if (code >= 0 && code < BY_CODE.length) {
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return BY_CODE[code];
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}
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return null;
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}
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}
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package dev.relism.flash.h2;
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/**
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* A <b>connection-level</b> HTTP/2 error. Thrown anywhere a peer's frame, HPACK block, or
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* SETTINGS value violates the protocol in a way that leaves the connection's state (the HPACK
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* dynamic table, a flow-control window, the stream table) unrecoverable.
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*
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* <p>The connection demux loop ({@code Http2Connection}, Phase 8) catches this exception at a
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* single site: it sends {@code GOAWAY} with {@link #errorCode()} and closes the connection.
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* Compare {@link Http2StreamException}, whose scope is one stream and which results in
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* {@code RST_STREAM} while the connection survives.
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*
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* <p>Deliberately does <b>not</b> extend {@link java.io.IOException}: the connection loop
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* distinguishes a protocol violation (a decision Flash made about the peer's bytes) from a
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* socket failure (the peer went away) by catching these as unrelated types. Conflating them
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* would make it possible to accidentally treat a hostile peer's malformed frame as a harmless
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* disconnect, or vice versa.
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*
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* <h3>Why stack traces are disabled</h3>
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* This exception is thrown on the connection's hot rejection path — a single malformed byte
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* from a hostile or buggy peer can trigger it, and under a scripted attack that can happen many
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* times per second across many connections. JVM stack trace capture ({@code fillInStackTrace})
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* is by far the most expensive part of constructing a {@code Throwable}, and it buys nothing
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* here: the call site is exactly where {@code errorCode()} says it is, and the debug message
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* already names the specific violation. The 4-argument {@link RuntimeException} constructor
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* disables both suppression and stack-trace writing.
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*
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* <h3>Preallocated singletons</h3>
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* For the common, message-less rejections (frame validation failures, HPACK structural errors)
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* this class exposes shared singleton instances. Reusing one instance across threads and across
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* many throws is safe <em>only because</em> the instance carries no per-throw mutable state and
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* writable-stack-trace is disabled — nothing about a throw mutates the exception object.
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*/
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public final class Http2Exception extends RuntimeException {
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private final Http2ErrorCode errorCode;
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private Http2Exception(Http2ErrorCode errorCode, String message) {
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super(message, null, false, false);
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this.errorCode = errorCode;
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}
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/** The RFC 9113 §7 error code to send in the {@code GOAWAY} frame. */
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public Http2ErrorCode errorCode() {
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return errorCode;
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}
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/**
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* Builds a connection error carrying a caller-supplied debug message. Allocates a new
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* instance — acceptable per R2, since this exception always terminates the connection and
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* R2 exempts error paths that terminate the connection. Use this overload whenever the
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* message carries information specific to this occurrence (e.g. the offending stream id or
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* a decoded value); use one of the preallocated singletons below when it does not.
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*/
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public static Http2Exception of(Http2ErrorCode code, String message) {
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return new Http2Exception(code, message);
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}
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// ── Preallocated, message-less singletons for the hot rejection paths ──────────────────
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public static final Http2Exception PROTOCOL_ERROR =
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new Http2Exception(Http2ErrorCode.PROTOCOL_ERROR, "protocol error");
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public static final Http2Exception FRAME_SIZE_ERROR =
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new Http2Exception(Http2ErrorCode.FRAME_SIZE_ERROR, "frame size error");
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public static final Http2Exception FLOW_CONTROL_ERROR =
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new Http2Exception(Http2ErrorCode.FLOW_CONTROL_ERROR, "flow control error");
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public static final Http2Exception COMPRESSION_ERROR =
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new Http2Exception(Http2ErrorCode.COMPRESSION_ERROR, "compression error");
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public static final Http2Exception INTERNAL_ERROR =
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new Http2Exception(Http2ErrorCode.INTERNAL_ERROR, "internal error");
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public static final Http2Exception SETTINGS_TIMEOUT =
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new Http2Exception(Http2ErrorCode.SETTINGS_TIMEOUT, "settings ack timeout");
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}
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@@ -0,0 +1,148 @@
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package dev.relism.flash.h2;
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/**
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* Every bound the HTTP/2 implementation enforces against a peer's input, in one place.
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*
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* <p>Per R8, any code that reads a length, an index, a count, or a size off the wire checks it
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* against a named constant here — never against an ad-hoc literal, and never by letting the
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* underlying array or buffer throw on overrun. Each field's Javadoc names the specific attack
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* or resource it bounds and, where one exists, the CVE.
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*
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* <p>These are compile-time defaults, not runtime configuration. The operationally-relevant
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* subset is promoted to {@code FlashConfiguration} in Phase 13 task 10, once the whole surface
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* has been exercised and it is clear which knobs operators actually need. Until then, changing
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* a limit means changing this file.
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*
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* <p>This class is added to incrementally: later phases add fields as the feature that needs
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* them lands (e.g. {@code WRITE_TIMEOUT_MS} in Phase 3, {@code FRAME_READ_TIMEOUT_MS} in
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* Phase 5). Phase 0 seeds the set called out explicitly by its task list; nothing here is a
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* forward-declared placeholder — every field is already used by the phase that introduces it.
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*/
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public final class Http2Limits {
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private Http2Limits() {
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}
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/**
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* Maximum number of streams a single connection may have open concurrently. Advertised to
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* the peer as {@code SETTINGS_MAX_CONCURRENT_STREAMS}. Bounds per-connection memory (each
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* open stream owns a per-stream HPACK arena and request/response state) against a peer that
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* simply opens streams and never closes them.
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*/
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public static final int MAX_CONCURRENT_STREAMS = 100;
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/**
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* The largest frame payload we accept without the peer first raising it via our own
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* {@code SETTINGS_MAX_FRAME_SIZE}. RFC 9113 §4.2 fixes the protocol default at 16384 and
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* requires any advertised value to stay within {@code 16384..16777215}. Bounds the memory a
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* single frame read can force us to hold.
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*/
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public static final int MAX_FRAME_SIZE_LOCAL = 16_384;
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/**
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* Maximum total size (name + value + 32 per RFC 7541 §4.1's accounting, summed over every
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* header) of a decoded header list. Advertised as {@code SETTINGS_MAX_HEADER_LIST_SIZE}
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* (RFC 9113 §6.5.2). This is the primary defence against an HPACK bomb: a small compressed
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* block that references dynamic-table entries to expand into an enormous header list.
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*/
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public static final int MAX_HEADER_LIST_SIZE = 32_768;
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/**
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* Maximum number of CONTINUATION frames accepted for a single header block before the
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* connection is torn down. Defence against CVE-2024-27316 (the "HTTP/2 CONTINUATION
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* Flood"): a peer that never sets {@code END_HEADERS} can otherwise force unbounded
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* decode/reassembly work per header block.
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*/
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public static final int MAX_CONTINUATION_FRAMES_PER_BLOCK = 8;
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/**
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* Maximum number of {@code RST_STREAM} frames accepted from the peer within
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* {@link #RESET_RATE_INTERVAL_MS}. Defence against CVE-2023-44487 ("HTTP/2 Rapid Reset"):
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* opening a stream and immediately resetting it does not count against
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* {@link #MAX_CONCURRENT_STREAMS}, so without a rate bound a peer can force unbounded
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* per-stream setup/teardown work at effectively unlimited concurrency.
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*/
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public static final int MAX_RESET_STREAMS_PER_INTERVAL = 200;
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/** The rolling window (milliseconds) over which {@link #MAX_RESET_STREAMS_PER_INTERVAL} is measured. */
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public static final long RESET_RATE_INTERVAL_MS = 10_000;
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/**
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* Maximum number of new streams accepted from the peer within
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* {@link #RESET_RATE_INTERVAL_MS}. A companion bound to
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* {@link #MAX_RESET_STREAMS_PER_INTERVAL}: Rapid Reset defences that only count resets can
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* still be bypassed by a peer that creates streams fast enough that the reset counter never
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* saturates within any single window boundary.
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*/
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public static final int MAX_STREAMS_CREATED_PER_INTERVAL = 400;
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/**
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* Maximum number of SETTINGS parameter entries accepted in a single SETTINGS frame. A
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* SETTINGS frame is already bounded in byte length by {@link #MAX_FRAME_SIZE_LOCAL} (each
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* entry is 6 bytes), but an explicit entry-count bound keeps the per-entry validation loop
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* itself cheap to reason about and gives a distinct, loud rejection reason.
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*/
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public static final int MAX_SETTINGS_ENTRIES_PER_FRAME = 64;
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/**
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* Maximum number of outstanding (unanswered) PING responses queued for the writer. A PING
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* flood forces a PONG per PING; without a bound, a peer that reads its own responses slowly
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* can make us buffer unbounded PONG frames.
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*/
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public static final int MAX_PING_QUEUE_DEPTH = 64;
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/**
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* Maximum number of zero-length DATA frames accepted per stream. Zero-length DATA consumes
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* no flow-control window, so window accounting does not bound it — without this limit a
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* peer can force unbounded per-frame dispatch/validation CPU work at zero cost to itself.
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*/
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public static final int MAX_EMPTY_DATA_FRAMES_PER_STREAM = 1_000;
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/**
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* The value of {@code SETTINGS_INITIAL_WINDOW_SIZE} Flash advertises for every new stream:
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* deliberately large (1 MiB, versus the RFC default of 65535) so that a normal-sized
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* request or response body never blocks on a WINDOW_UPDATE round trip. See Phase 11 task 1.
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*/
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public static final int INITIAL_WINDOW_SIZE_LOCAL = 1_048_576;
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/**
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* The connection-level flow-control window Flash advertises. Sized above
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* {@link #INITIAL_WINDOW_SIZE_LOCAL} so a single active stream is never bottlenecked by the
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* connection window before its own stream window, but well below
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* {@code MAX_CONCURRENT_STREAMS * INITIAL_WINDOW_SIZE_LOCAL} — real traffic is never all
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* streams simultaneously saturating their windows, and sizing for that worst case would
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* commit 100 MiB of receive window to every connection regardless of load.
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*/
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public static final int CONNECTION_WINDOW_SIZE_LOCAL = 16 * 1_048_576;
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/**
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* The HPACK dynamic table size Flash's decoder honours, in bytes of RFC 7541 §4.1
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* accounting. RFC 7541's protocol default. The encoder never uses a dynamic table at all
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* (DEC-04), so this bound applies only to headers <em>we receive</em>.
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*/
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public static final int HPACK_DYNAMIC_TABLE_SIZE_LOCAL = 4_096;
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/**
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* Maximum length, in decoded bytes, of a single HPACK string literal. Applied during
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* Huffman decode as bytes are produced, not to the encoded length — a Huffman string can
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* expand by roughly 8/5, so bounding only the encoded length would let a compact input
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* still decode past this limit.
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*/
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public static final int MAX_HPACK_STRING_LENGTH = 8_192;
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/**
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* Maximum time, in milliseconds, allowed between a HEADERS frame's arrival and the header
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* block's completion (its {@code END_HEADERS} flag, possibly after CONTINUATION frames). A
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* peer that starts a header block and then stalls indefinitely would otherwise hold the
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* per-stream arena and the connection's HPACK assembly buffer forever.
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*/
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public static final long HEADER_BLOCK_ASSEMBLY_TIMEOUT_MS = 10_000;
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/**
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* Maximum time, in milliseconds, a stream may remain open with no frame activity in either
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* direction. Bounds resource pinning by a peer that opens a stream and then goes silent
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* without closing it — the h2 equivalent of the h1 slowloris defence in
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* {@code FlashConfiguration.idleKeepAliveTimeoutMs}.
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*/
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public static final long STREAM_IDLE_TIMEOUT_MS = 60_000;
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}
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@@ -0,0 +1,46 @@
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package dev.relism.flash.h2;
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/**
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* A <b>stream-level</b> HTTP/2 error, scoped to one stream id. Results in an {@code RST_STREAM}
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* frame for {@link #streamId()} with {@link #errorCode()}; the connection and every other
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* stream on it are unaffected. Compare {@link Http2Exception}, whose scope is the whole
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* connection.
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*
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* <p>Deliberately does <b>not</b> extend {@link java.io.IOException}, for the same reason as
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* {@link Http2Exception}: the connection loop must be able to distinguish "we decided to reject
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* this stream" from "the socket failed" by catching unrelated exception types.
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*
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* <h3>Why this allocates, unlike {@code Http2Exception}'s singletons</h3>
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* Every instance carries a distinct {@link #streamId()}, so it cannot be a shared singleton the
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* way {@code Http2Exception}'s message-less constants are. This is still acceptable under R2:
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* {@code RST_STREAM} generation is an error path, not the steady-state request path, and R2
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* exempts error paths. The scenario where this matters most — a peer opening and resetting
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* thousands of streams per second (the Rapid Reset pattern, CVE-2023-44487) — is bounded by
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* rate limits (Phase 13), not by making the rejection itself allocation-free; a hostile peer
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* that can force RST_STREAM generation fast enough for GC pressure to matter has already
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* tripped {@code Http2Limits.MAX_RESET_STREAMS_PER_INTERVAL} and the connection is being torn
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* down anyway.
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*
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* <p>Stack trace capture is disabled for the same cost reason as {@link Http2Exception}.
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*/
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public final class Http2StreamException extends RuntimeException {
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private final Http2ErrorCode errorCode;
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private final int streamId;
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public Http2StreamException(int streamId, Http2ErrorCode errorCode, String message) {
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super(message, null, false, false);
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this.streamId = streamId;
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this.errorCode = errorCode;
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}
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/** The id of the stream this error terminates. */
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public int streamId() {
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return streamId;
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}
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/** The RFC 9113 §7 error code to send in the {@code RST_STREAM} frame. */
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public Http2ErrorCode errorCode() {
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return errorCode;
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}
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}
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@@ -0,0 +1,73 @@
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/**
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* HTTP/2 (RFC 9113) and HPACK (RFC 7541), as a peer transport to HTTP/1.1 — not a special case
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* bolted onto it. This package lives in {@code flash} core, not an extension, because the
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* protocol decision is made at the transport layer, where {@code HttpServer}'s replacement
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* lives (see {@code DEC-01} in {@code flash/docs/http2/DECISIONS.md}).
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*
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* <h2>Architecture in one page</h2>
|
||||
*
|
||||
* <h3>The demux loop</h3>
|
||||
* One virtual thread per connection reads and dispatches frames
|
||||
* ({@code Http2Connection}, Phase 8): read a 9-byte frame header, validate it against the
|
||||
* per-type table ({@code FrameValidator}, Phase 5), dispatch by type. This loop <b>never blocks
|
||||
* on application work</b> — a slow handler must never stall frame processing for other streams
|
||||
* on the same connection, which is the entire point of multiplexing. The only things the demux
|
||||
* thread itself does synchronously are protocol bookkeeping: SETTINGS/PING/WINDOW_UPDATE
|
||||
* accounting, HPACK decode, and stream-table updates.
|
||||
*
|
||||
* <h3>Virtual-thread-per-stream dispatch</h3>
|
||||
* Once a request's headers (and, for small bodies, its body) are fully assembled, the demux
|
||||
* thread submits a task to the shared virtual-thread executor and returns immediately to
|
||||
* reading frames. Routing, middleware, and the user's handler run on that stream's own virtual
|
||||
* thread — identical to the HTTP/1.1 dispatch model, so a handler written for h1 works
|
||||
* unmodified over h2 (verified in Phase 10).
|
||||
*
|
||||
* <h3>The writer discipline</h3>
|
||||
* N stream threads share one socket. {@code Http2FrameWriter} (Phase 3) is the single
|
||||
* serialization point: a stream serializes its complete frame (header + HPACK block + payload)
|
||||
* into a reusable per-stream scratch buffer, then takes a connection-wide {@link
|
||||
* java.util.concurrent.locks.ReentrantLock} — never {@code synchronized}, which pins a virtual
|
||||
* thread's carrier on Java 21 (see {@code DEC-03}) — and issues one bulk write. The uncontended
|
||||
* path costs one CAS ({@code tryLock()}); contention falls back to an intrusive, allocation-free
|
||||
* MPSC queue rather than blocking every writer on the lock. This is the project's single
|
||||
* largest architectural risk and is proven or falsified by Phase 3's benchmark gate before any
|
||||
* frame-layer code is written.
|
||||
*
|
||||
* <h3>The arena strategy</h3>
|
||||
* HPACK is stateful compression: header bytes that enter the dynamic table must outlive the
|
||||
* connection read buffer, and Huffman-coded values must be decoded somewhere. Flash copies each
|
||||
* decoded header into a <b>per-stream arena</b>, not a shared one ({@code DEC-06}). This is not
|
||||
* the minimal-copy design — a refcounted shared dynamic table would copy less — but it is the
|
||||
* only design that is correct by construction under concurrent multiplexing: the demux thread
|
||||
* can decode another stream's HEADERS, evicting dynamic-table entries, while a handler on a
|
||||
* different virtual thread is still reading a view into a previous decode. A per-stream arena
|
||||
* makes that race impossible without any cross-thread coordination on the hot path. See
|
||||
* {@code flash/docs/http2/HPACK.md} (Phase 7) for the worked example.
|
||||
*
|
||||
* <h2>What this package deliberately does not implement</h2>
|
||||
* <ul>
|
||||
* <li><b>Server push ({@code PUSH_PROMISE}).</b> Flash never sends it and rejects any
|
||||
* {@code PUSH_PROMISE} received from a client as a connection error, since only servers may
|
||||
* send it (RFC 9113 §8.4). Flash advertises {@code SETTINGS_ENABLE_PUSH = 0}. Justification:
|
||||
* push is widely disabled by browsers and its cache-coherency benefits are better served by
|
||||
* {@code 103 Early Hints} or resource hints, which do not require protocol-level state.</li>
|
||||
* <li><b>Priority scheduling ({@code PRIORITY} frames, and the deprecated priority fields on
|
||||
* {@code HEADERS}).</b> RFC 9113 §5.3.2 itself says endpoints "SHOULD ignore" priority
|
||||
* signalling — it was deprecated in the same RFC that (re)defined HTTP/2. Flash parses and
|
||||
* discards {@code PRIORITY} frames (they must still be consumed, not rejected) and never acts
|
||||
* on the priority fields.</li>
|
||||
* <li><b>{@code Upgrade: h2c}.</b> RFC 9113 §3.1 removed the HTTP/1.1 upgrade mechanism that
|
||||
* RFC 7540 §3.2 defined. Cleartext HTTP/2 is reached only via prior knowledge (RFC 9113 §3.4),
|
||||
* which is what every modern h2c client (notably gRPC) actually uses. See {@code DEC-10}.</li>
|
||||
* </ul>
|
||||
*
|
||||
* <h2>Package layout</h2>
|
||||
* This package is filled in incrementally, phase by phase — see
|
||||
* {@code flash/docs/http2/IMPLEMENTATION-PLAN.md} Part III for the full schedule. As of Phase 0
|
||||
* it contains only the error model ({@link dev.relism.flash.h2.Http2ErrorCode},
|
||||
* {@link dev.relism.flash.h2.Http2Exception}, {@link dev.relism.flash.h2.Http2StreamException})
|
||||
* and the limits registry ({@link dev.relism.flash.h2.Http2Limits}). Subpackages
|
||||
* {@code frame}, {@code hpack}, {@code stream}, {@code message}, and {@code upgrade} are added
|
||||
* by Phases 3, 5, 7–9, and 14–15 respectively.
|
||||
*/
|
||||
package dev.relism.flash.h2;
|
||||
@@ -0,0 +1,58 @@
|
||||
package dev.relism.flash.http;
|
||||
|
||||
/**
|
||||
* Bounds the HTTP/1.1 parser ({@code RequestParser}, {@code ChunkedInputStream}) enforces
|
||||
* against a peer's input, in one place.
|
||||
*
|
||||
* <p>Per R8, any code that reads a length, an index, a count, or a size off the wire checks it
|
||||
* against a named constant here — never against an ad-hoc literal, and never by letting the
|
||||
* underlying buffer throw on overrun. Each field's Javadoc names the specific attack it bounds.
|
||||
*
|
||||
* <p>Seeded in Phase 0 with the bounds required by {@code EX-03} (strict {@code Content-Length}
|
||||
* parsing) and {@code EX-08} (header count/size limits); extended in Phase 1 with the chunked-
|
||||
* transfer bounds ({@code EX-10}) and again in later phases as new h1 surfaces need a limit.
|
||||
* Compare {@code dev.relism.flash.h2.Http2Limits}, the HTTP/2 equivalent.
|
||||
*/
|
||||
public final class Http1Limits {
|
||||
|
||||
private Http1Limits() {
|
||||
}
|
||||
|
||||
/**
|
||||
* The largest {@code Content-Length} value accepted, in bytes. RFC 9112 places no upper
|
||||
* bound on the header's numeric value, but an unbounded value from a hostile peer is a
|
||||
* resource-exhaustion vector for any code path that pre-sizes a buffer from it. Requests
|
||||
* declaring a length above this are rejected with {@code 413 Payload Too Large} before any
|
||||
* body byte is read.
|
||||
*/
|
||||
public static final long MAX_CONTENT_LENGTH = 100L * 1024 * 1024;
|
||||
|
||||
/**
|
||||
* Maximum number of header lines accepted in a single request. Without this bound, a
|
||||
* request with tens of thousands of one-byte headers passes the total header-block size
|
||||
* check ({@code maxHeaderBufferSize}) while still forcing every subsequent
|
||||
* {@code HeaderMap} lookup to scan all of them — turning a small request into quadratic CPU
|
||||
* work per middleware that reads a header ({@code EX-08}, {@code EX-09}).
|
||||
*/
|
||||
public static final int MAX_HEADER_COUNT = 100;
|
||||
|
||||
/**
|
||||
* Maximum length, in bytes, of a single header field name. RFC 9110 §5.1 places no formal
|
||||
* limit; this bound exists purely to cap per-header memory and scan cost.
|
||||
*/
|
||||
public static final int MAX_HEADER_NAME_LENGTH = 256;
|
||||
|
||||
/**
|
||||
* Maximum length, in bytes, of a single header field value. Bounds per-header memory and
|
||||
* scan cost the same way {@link #MAX_HEADER_NAME_LENGTH} bounds the name.
|
||||
*/
|
||||
public static final int MAX_HEADER_VALUE_LENGTH = 8_192;
|
||||
|
||||
/**
|
||||
* Maximum length, in bytes, of the request line ({@code METHOD SP target SP version}).
|
||||
* Tracked separately from the overall header-buffer size so an oversized request line is
|
||||
* rejected with a specific, correct status ({@code 414 URI Too Long}) rather than folded
|
||||
* into the generic header-block-too-large case.
|
||||
*/
|
||||
public static final int MAX_REQUEST_LINE_LENGTH = 8_192;
|
||||
}
|
||||
Reference in New Issue
Block a user