wtwire.h File Reference

WebTransport wire-format helpers (pure functions, no state). More...

#include "common/bytes/span/span.h"
#include "common/platform/sys/syscall.h"

Go to the source code of this file.

Functions
usz	wired_wtwire_signal_put (u8 *buf, usz cap, int bidi, u64 session_id)
	Write the uni (bidi=0) / bidi (bidi=1) stream signal prefix into buf.
usz	wtwire_qsid_put (u8 *buf, usz cap, u64 session_id)
	Write the datagram quarter-stream-ID prefix varint(session_id / 4).
usz	wired_wtwire_qsid_take (wired_span dg, u64 *session_id)
	Read the quarter-stream-ID varint at the head of a datagram.
int	wired_wtwire_get_parse (wired_span line, wired_span *file)
	Parse a "GET <filename>" line.
usz	wired_wtwire_get_put (u8 *buf, usz cap, wired_span filename)
	Write "GET <filename>" (no trailing newline) into buf.
int	wired_wtwire_push_parse (wired_span msg, wired_span *name, wired_span *content)
	Parse a "PUSH <name>\n<content>" message.
usz	wired_wtwire_push_head_put (u8 *buf, usz cap, wired_span basename)
	Write the push header "PUSH <basename>\n" into buf.
wired_span	wired_wtwire_basename (wired_span path)
	View of the path component after the last '/'; the whole path if it has no '/'.

Detailed Description

WebTransport wire-format helpers (pure functions, no state).

Covers three small wire shapes used against the webtransport-go reference implementation in the quic-interop-runner:

• Stream signal prefix: a WebTransport stream opens with varint(0x54) (unidirectional) or varint(0x41) (bidirectional) followed by varint(session_id), where session_id is the QUIC stream ID of the Extended CONNECT stream itself (always a multiple of 4, not divided).
• HTTP Datagram prefix (RFC 9297 SS2.1): varint(session_id / 4), the quarter stream ID.
• The interop-runner line protocol: "GET <filename>" requests and "PUSH <name>\n<content>" pushes.

Function Documentation

wired_wtwire_basename()

wired_span wired_wtwire_basename

(

wired_span

path

)

View of the path component after the last '/'; the whole path if it has no '/'.

A path ending in '/' yields an empty span.

Parameters

path	the input path

Returns

the basename view (borrows path's bytes)

wired_wtwire_get_parse()

int wired_wtwire_get_parse	(	wired_span	line,
		wired_span *	file )

Parse a "GET <filename>" line.

The filename is trimmed of surrounding spaces, tabs, and line endings; an empty trimmed name is an error.

Parameters

line	the request line (trailing newline optional)
file	set to a view of the trimmed filename on success

Returns

1 on success, 0 on failure

wired_wtwire_get_put()

usz wired_wtwire_get_put	(	u8 *	buf,
		usz	cap,
		wired_span	filename )

Write "GET <filename>" (no trailing newline) into buf.

Parameters

buf	destination
cap	capacity of buf
filename	the requested file name

Returns

bytes written, or 0 if it does not fit

wired_wtwire_push_head_put()

usz wired_wtwire_push_head_put	(	u8 *	buf,
		usz	cap,
		wired_span	basename )

Write the push header "PUSH <basename>\n" into buf.

Parameters

buf	destination
cap	capacity of buf
basename	the pushed file's base name

Returns

bytes written, or 0 if it does not fit

wired_wtwire_push_parse()

int wired_wtwire_push_parse	(	wired_span	msg,
		wired_span *	name,
		wired_span *	content )

Parse a "PUSH <name>\n<content>" message.

The split is at the first newline; the name is trimmed, and an empty trimmed name or a missing newline is an error. content may be empty.

Parameters

msg	the full push message
name	set to a view of the trimmed name on success
content	set to a view of the bytes after the newline on success

Returns

1 on success, 0 on failure

wired_wtwire_qsid_take()

usz wired_wtwire_qsid_take	(	wired_span	dg,
		u64 *	session_id )

Read the quarter-stream-ID varint at the head of a datagram.

RFC 9297 SS2.1: a Quarter Stream ID above 2^60-1 does not map to any legal QUIC stream ID (session_id = qsid * 4 would exceed the 2^62-1 stream ID space) and is a decode failure, same as a truncated varint.

Parameters

dg	the datagram payload
session_id	set to quarter stream ID * 4 on success

Returns

bytes consumed, or 0 if the varint is truncated/missing/too large

wired_wtwire_signal_put()

usz wired_wtwire_signal_put	(	u8 *	buf,
		usz	cap,
		int	bidi,
		u64	session_id )

Write the uni (bidi=0) / bidi (bidi=1) stream signal prefix into buf.

Parameters

buf	destination
cap	capacity of buf
bidi	nonzero for a bidirectional stream (0x41), else 0x54
session_id	QUIC stream ID of the Extended CONNECT stream

Returns

bytes written, or 0 if it does not fit

wtwire_qsid_put()

usz wtwire_qsid_put	(	u8 *	buf,
		usz	cap,
		u64	session_id )

Write the datagram quarter-stream-ID prefix varint(session_id / 4).

Parameters

buf	destination
cap	capacity of buf
session_id	QUIC stream ID of the Extended CONNECT stream

Returns

bytes written, or 0 if it does not fit