HTTP/3 framing (RFC 9114 sec 7) over QUIC varints. More...

#include "protocore_config.h"

Classes
struct	H3FrameHeader
	A parsed frame header (payload begins at buf + header_len). More...

struct	H3Settings
	The settings we track, with defaults after H3FrameNs::settings_defaults. More...

struct	H3FrameNs
	Dispatch table. Addressed by offset, so the layout is asserted below. More...

Macros
#define	H3_DATA 0x00
	HTTP/3 frame types (RFC 9114 sec 7.2 / 11.2.1).

#define	H3_HEADERS 0x01

#define	H3_CANCEL_PUSH 0x03

#define	H3_SETTINGS 0x04

#define	H3_PUSH_PROMISE 0x05

#define	H3_GOAWAY 0x07

#define	H3_MAX_PUSH_ID 0x0d

#define	H3_NO_ERROR 0x0100
	HTTP/3 error codes (RFC 9114 sec 8.1).

#define	H3_GENERAL_PROTOCOL_ERROR 0x0101

#define	H3_INTERNAL_ERROR 0x0102

#define	H3_STREAM_CREATION_ERROR 0x0103

#define	H3_CLOSED_CRITICAL_STREAM 0x0104

#define	H3_FRAME_UNEXPECTED 0x0105

#define	H3_FRAME_ERROR 0x0106

#define	H3_EXCESSIVE_LOAD 0x0107

#define	H3_ID_ERROR 0x0108

#define	H3_SETTINGS_ERROR 0x0109

#define	H3_MISSING_SETTINGS 0x010a

#define	H3_REQUEST_REJECTED 0x010b

#define	H3_REQUEST_CANCELLED 0x010c

#define	H3_REQUEST_INCOMPLETE 0x010d

#define	H3_MESSAGE_ERROR 0x010e

#define	H3_CONNECT_ERROR 0x010f

#define	H3_VERSION_FALLBACK 0x0110

#define	H3_SETTINGS_QPACK_MAX_TABLE_CAPACITY 0x01
	SETTINGS parameter identifiers (RFC 9114 sec 7.2.4.1 + RFC 9204).

#define	H3_SETTINGS_MAX_FIELD_SECTION_SIZE 0x06

#define	H3_SETTINGS_QPACK_BLOCKED_STREAMS 0x07

Functions
	PROTOCORE_NS_LAYOUT (H3FrameNs, parse_header, write_header, type_reserved, settings_defaults, parse_settings, build_data, build_headers, build_settings, build_goaway)

proto_bool	protocore_h3_frame_parse_header (uint8_t work, const uint8_t buf, size_t len, H3FrameHeader *out)
	Parse a frame header (type + length varints) at buf. false if .

size_t	protocore_h3_frame_write_header (uint8_t work, uint8_t out, size_t cap, uint64_t type, uint64_t length)
	Write a frame header (type + length varints). bytes written, or 0 .

proto_bool	protocore_h3_frame_type_reserved (uint8_t *work, uint64_t type)
	True if type is a reserved HTTP/2 frame type (0x02/0x06/0x08/0x09) .

void	protocore_h3_frame_settings_defaults (uint8_t work, H3Settings s)
	Fill s with the RFC default settings.

proto_bool	protocore_h3_frame_parse_settings (uint8_t work, const uint8_t payload, size_t len, H3Settings *s)
	Apply a SETTINGS payload (id, value varint pairs) to s. false if .

size_t	protocore_h3_frame_build_data (uint8_t work, uint8_t out, size_t cap, const uint8_t *data, size_t len)
	DATA frame wrapping data.

size_t	protocore_h3_frame_build_headers (uint8_t work, uint8_t out, size_t cap, const uint8_t *block, size_t len)
	HEADERS frame wrapping a QPACK-encoded field section block.

size_t	protocore_h3_frame_build_settings (uint8_t work, uint8_t out, size_t cap, const uint64_t ids, const uint64_t vals, size_t n)
	SETTINGS frame from n (id, value) pairs.

size_t	protocore_h3_frame_build_goaway (uint8_t work, uint8_t out, size_t cap, uint64_t stream_id)
	GOAWAY frame carrying stream_id (RFC 9114 sec 7.2.6).

Variables
PROTOCORE_NS H3FrameNs H3Frame	PROTOCORE_UNUSED
	Module namespace.

Detailed Description

HTTP/3 framing (RFC 9114 sec 7) over QUIC varints.

An HTTP/3 frame is Type (varint) | Length (varint) | Frame Payload. This module parses that header and builds the frames a server uses (DATA, HEADERS carrying a QPACK field section, SETTINGS, GOAWAY), reads a SETTINGS payload, and flags the reserved HTTP/2 frame types that must be treated as a connection error. Pure and host-tested.

work is bytes the CALLER holds. This module reads none of them: it carries nothing between calls, so there is no state to keep and nothing to wipe. The parameter is there so a caller drives every namespace the same way.

Author: Douglas Quigg (dstroy0)

Date: 2026

Definition in file h3_frame.h.

Macro Definition Documentation

◆ H3_DATA

#define H3_DATA 0x00

HTTP/3 frame types (RFC 9114 sec 7.2 / 11.2.1).

Definition at line 33 of file h3_frame.h.

◆ H3_HEADERS

#define H3_HEADERS 0x01

Definition at line 34 of file h3_frame.h.

◆ H3_CANCEL_PUSH

#define H3_CANCEL_PUSH 0x03

Definition at line 35 of file h3_frame.h.

◆ H3_SETTINGS

#define H3_SETTINGS 0x04

Definition at line 36 of file h3_frame.h.

◆ H3_PUSH_PROMISE

#define H3_PUSH_PROMISE 0x05

Definition at line 37 of file h3_frame.h.

◆ H3_GOAWAY

#define H3_GOAWAY 0x07

Definition at line 38 of file h3_frame.h.

◆ H3_MAX_PUSH_ID

#define H3_MAX_PUSH_ID 0x0d

Definition at line 39 of file h3_frame.h.

◆ H3_NO_ERROR

#define H3_NO_ERROR 0x0100

HTTP/3 error codes (RFC 9114 sec 8.1).

These travel in a CONNECTION_CLOSE of type 0x1d, whose error code comes from the application protocol's space. Sent in the transport variant (0x1c) they would be read against RFC 9000 sec 20.1 instead, where 0x0100-0x01ff is CRYPTO_ERROR plus a TLS alert.

Definition at line 48 of file h3_frame.h.

◆ H3_GENERAL_PROTOCOL_ERROR

#define H3_GENERAL_PROTOCOL_ERROR 0x0101

Definition at line 49 of file h3_frame.h.

◆ H3_INTERNAL_ERROR

#define H3_INTERNAL_ERROR 0x0102

Definition at line 50 of file h3_frame.h.

◆ H3_STREAM_CREATION_ERROR

#define H3_STREAM_CREATION_ERROR 0x0103

Definition at line 51 of file h3_frame.h.

◆ H3_CLOSED_CRITICAL_STREAM

#define H3_CLOSED_CRITICAL_STREAM 0x0104

Definition at line 52 of file h3_frame.h.

◆ H3_FRAME_UNEXPECTED

#define H3_FRAME_UNEXPECTED 0x0105

Definition at line 53 of file h3_frame.h.

◆ H3_FRAME_ERROR

#define H3_FRAME_ERROR 0x0106

Definition at line 54 of file h3_frame.h.

◆ H3_EXCESSIVE_LOAD

#define H3_EXCESSIVE_LOAD 0x0107

Definition at line 55 of file h3_frame.h.

◆ H3_ID_ERROR

#define H3_ID_ERROR 0x0108

Definition at line 56 of file h3_frame.h.

◆ H3_SETTINGS_ERROR

#define H3_SETTINGS_ERROR 0x0109

Definition at line 57 of file h3_frame.h.

◆ H3_MISSING_SETTINGS

#define H3_MISSING_SETTINGS 0x010a

Definition at line 58 of file h3_frame.h.

◆ H3_REQUEST_REJECTED

#define H3_REQUEST_REJECTED 0x010b

Definition at line 59 of file h3_frame.h.

◆ H3_REQUEST_CANCELLED

#define H3_REQUEST_CANCELLED 0x010c

Definition at line 60 of file h3_frame.h.

◆ H3_REQUEST_INCOMPLETE

#define H3_REQUEST_INCOMPLETE 0x010d

Definition at line 61 of file h3_frame.h.

◆ H3_MESSAGE_ERROR

#define H3_MESSAGE_ERROR 0x010e

Definition at line 62 of file h3_frame.h.

◆ H3_CONNECT_ERROR

#define H3_CONNECT_ERROR 0x010f

Definition at line 63 of file h3_frame.h.

◆ H3_VERSION_FALLBACK

#define H3_VERSION_FALLBACK 0x0110

Definition at line 64 of file h3_frame.h.

◆ H3_SETTINGS_QPACK_MAX_TABLE_CAPACITY

#define H3_SETTINGS_QPACK_MAX_TABLE_CAPACITY 0x01

SETTINGS parameter identifiers (RFC 9114 sec 7.2.4.1 + RFC 9204).

Definition at line 67 of file h3_frame.h.

◆ H3_SETTINGS_MAX_FIELD_SECTION_SIZE

#define H3_SETTINGS_MAX_FIELD_SECTION_SIZE 0x06

Definition at line 68 of file h3_frame.h.

◆ H3_SETTINGS_QPACK_BLOCKED_STREAMS

#define H3_SETTINGS_QPACK_BLOCKED_STREAMS 0x07

Definition at line 69 of file h3_frame.h.

Function Documentation

◆ PROTOCORE_NS_LAYOUT()

PROTOCORE_NS_LAYOUT	(	H3FrameNs	,
		parse_header	,
		write_header	,
		type_reserved	,
		settings_defaults	,
		parse_settings	,
		build_data	,
		build_headers	,
		build_settings	,
		build_goaway
	)

◆ protocore_h3_frame_parse_header()

proto_bool protocore_h3_frame_parse_header	(	uint8_t *	work,
		const uint8_t *	buf,
		size_t	len,
		H3FrameHeader *	out
	)

Parse a frame header (type + length varints) at buf. false if .

Parameters

work	PROTOCORE_H3_FRAME_BORROW bytes the caller took. Not held past the call.
buf	Buf
len	Len
out	Out

Returns: PROTO_TRUE on success.

◆ protocore_h3_frame_write_header()

size_t protocore_h3_frame_write_header	(	uint8_t *	work,
		uint8_t *	out,
		size_t	cap,
		uint64_t	type,
		uint64_t	length
	)

Write a frame header (type + length varints). bytes written, or 0 .

Parameters

work	PROTOCORE_H3_FRAME_BORROW bytes the caller took. Not held past the call.
out	Out
cap	Cap
type	Type
length	Length

Returns: The size_t.

◆ protocore_h3_frame_type_reserved()

proto_bool protocore_h3_frame_type_reserved	(	uint8_t *	work,
		uint64_t	type
	)

True if type is a reserved HTTP/2 frame type (0x02/0x06/0x08/0x09) .

Parameters

work	PROTOCORE_H3_FRAME_BORROW bytes the caller took. Not held past the call.
type	Type

Returns: PROTO_TRUE on success.

◆ protocore_h3_frame_settings_defaults()

void protocore_h3_frame_settings_defaults	(	uint8_t *	work,
		H3Settings *	s
	)

Fill s with the RFC default settings.

Parameters

work	PROTOCORE_H3_FRAME_BORROW bytes the caller took. Not held past the call.
s	S

◆ protocore_h3_frame_parse_settings()

proto_bool protocore_h3_frame_parse_settings	(	uint8_t *	work,
		const uint8_t *	payload,
		size_t	len,
		H3Settings *	s
	)

Apply a SETTINGS payload (id, value varint pairs) to s. false if .

Parameters

work	PROTOCORE_H3_FRAME_BORROW bytes the caller took. Not held past the call.
payload	Payload
len	Len
s	S

Returns: PROTO_TRUE on success.

◆ protocore_h3_frame_build_data()

size_t protocore_h3_frame_build_data	(	uint8_t *	work,
		uint8_t *	out,
		size_t	cap,
		const uint8_t *	data,
		size_t	len
	)

DATA frame wrapping data.

Parameters

work	PROTOCORE_H3_FRAME_BORROW bytes the caller took. Not held past the call.
out	Out
cap	Cap
data	Data
len	Len

Returns: The size_t.

◆ protocore_h3_frame_build_headers()

size_t protocore_h3_frame_build_headers	(	uint8_t *	work,
		uint8_t *	out,
		size_t	cap,
		const uint8_t *	block,
		size_t	len
	)

HEADERS frame wrapping a QPACK-encoded field section block.

Parameters

work	PROTOCORE_H3_FRAME_BORROW bytes the caller took. Not held past the call.
out	Out
cap	Cap
block	Block
len	Len

Returns: The size_t.

◆ protocore_h3_frame_build_settings()

size_t protocore_h3_frame_build_settings	(	uint8_t *	work,
		uint8_t *	out,
		size_t	cap,
		const uint64_t *	ids,
		const uint64_t *	vals,
		size_t	n
	)

SETTINGS frame from n (id, value) pairs.

Parameters

work	PROTOCORE_H3_FRAME_BORROW bytes the caller took. Not held past the call.
out	Out
cap	Cap
ids	Ids
vals	Vals
n	N

Returns: The size_t.

◆ protocore_h3_frame_build_goaway()

size_t protocore_h3_frame_build_goaway	(	uint8_t *	work,
		uint8_t *	out,
		size_t	cap,
		uint64_t	stream_id
	)

GOAWAY frame carrying stream_id (RFC 9114 sec 7.2.6).

Parameters

work	PROTOCORE_H3_FRAME_BORROW bytes the caller took. Not held past the call.
out	Out
cap	Cap
stream_id	Stream id

Returns: The size_t.

Variable Documentation

◆ PROTOCORE_UNUSED

PROTOCORE_NS H3FrameNs H3Frame PROTOCORE_UNUSED

Initial value:

= {.parse_header = protocore_h3_frame_parse_header,
                                                   .write_header = protocore_h3_frame_write_header,
                                                   .type_reserved = protocore_h3_frame_type_reserved,
                                                   .settings_defaults = protocore_h3_frame_settings_defaults,
                                                   .parse_settings = protocore_h3_frame_parse_settings,
                                                   .build_data = protocore_h3_frame_build_data,
                                                   .build_headers = protocore_h3_frame_build_headers,
                                                   .build_settings = protocore_h3_frame_build_settings,
                                                   .build_goaway = protocore_h3_frame_build_goaway}

Module namespace.

Definition at line 187 of file h3_frame.h.

Classes

Macros

Functions

Variables

Detailed Description

Macro Definition Documentation

◆ H3_DATA

◆ H3_HEADERS

◆ H3_CANCEL_PUSH

◆ H3_SETTINGS

◆ H3_PUSH_PROMISE

◆ H3_GOAWAY

◆ H3_MAX_PUSH_ID

◆ H3_NO_ERROR

◆ H3_GENERAL_PROTOCOL_ERROR

◆ H3_INTERNAL_ERROR

◆ H3_STREAM_CREATION_ERROR

◆ H3_CLOSED_CRITICAL_STREAM

◆ H3_FRAME_UNEXPECTED

◆ H3_FRAME_ERROR

◆ H3_EXCESSIVE_LOAD

◆ H3_ID_ERROR

◆ H3_SETTINGS_ERROR

◆ H3_MISSING_SETTINGS

◆ H3_REQUEST_REJECTED

◆ H3_REQUEST_CANCELLED

◆ H3_REQUEST_INCOMPLETE

◆ H3_MESSAGE_ERROR

◆ H3_CONNECT_ERROR

◆ H3_VERSION_FALLBACK

◆ H3_SETTINGS_QPACK_MAX_TABLE_CAPACITY

◆ H3_SETTINGS_MAX_FIELD_SECTION_SIZE

◆ H3_SETTINGS_QPACK_BLOCKED_STREAMS

Function Documentation

◆ PROTOCORE_NS_LAYOUT()

◆ protocore_h3_frame_parse_header()

◆ protocore_h3_frame_write_header()

◆ protocore_h3_frame_type_reserved()

◆ protocore_h3_frame_settings_defaults()

◆ protocore_h3_frame_parse_settings()

◆ protocore_h3_frame_build_data()

◆ protocore_h3_frame_build_headers()

◆ protocore_h3_frame_build_settings()

◆ protocore_h3_frame_build_goaway()

Variable Documentation

◆ PROTOCORE_UNUSED