view auto/have_headers @ 9191:618132842e7c

QUIC: ignore duplicate PATH_CHALLENGE frames. According to RFC 9000, an endpoint SHOULD NOT send multiple PATH_CHALLENGE frames in a single packet. The change adds a check to enforce this claim to optimize server behavior. Previously each PATH_CHALLENGE always resulted in a single response datagram being sent to client. The effect of this was however limited by QUIC flood protection. Also, PATH_CHALLENGE is explicitly disabled in Initial and Handshake levels, see RFC 9000, Table 3. However, technically it may be sent by client in 0-RTT over a new path without actual migration, even though the migration itself is prohibited during handshake. This allows client to coalesce multiple 0-RTT packets each carrying a PATH_CHALLENGE and end up with multiple PATH_CHALLENGEs per datagram. This again leads to suboptimal behavior, see above. Since the purpose of sending PATH_CHALLENGE frames in 0-RTT is unclear, these frames are now only allowed in 1-RTT. For 0-RTT they are silently ignored.
author Roman Arutyunyan <arut@nginx.com>
date Wed, 22 Nov 2023 14:48:12 +0400
parents d620f497c50f
children
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# Copyright (C) Igor Sysoev
# Copyright (C) Nginx, Inc.


cat << END >> $NGX_AUTO_HEADERS_H

#ifndef $have
#define $have  1
#endif

END