Mercurial > hg > nginx-quic
changeset 8798:077a1e403446 quic
QUIC: additional limit for probing packets.
RFC 9000, 9.3. Responding to Connection Migration:
An endpoint only changes the address to which it sends packets in
response to the highest-numbered non-probing packet.
The patch extends this requirement to probing packets. Although it may
seem excessive, it helps with mitigation of reply attacks (when an off-path
attacker has copied packet with PATH_CHALLENGE and uses different
addresses to exhaust available connection ids).
author | Vladimir Homutov <vl@nginx.com> |
---|---|
date | Thu, 20 Jan 2022 22:00:25 +0300 |
parents | 1e2f4e9c8195 |
children | e5509ff0dfd2 |
files | src/event/quic/ngx_event_quic_migration.c |
diffstat | 1 files changed, 11 insertions(+), 0 deletions(-) [+] |
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--- a/src/event/quic/ngx_event_quic_migration.c +++ b/src/event/quic/ngx_event_quic_migration.c @@ -255,6 +255,7 @@ ngx_quic_set_path(ngx_connection_t *c, n ngx_queue_t *q; ngx_quic_path_t *path, *probe; ngx_quic_socket_t *qsock; + ngx_quic_send_ctx_t *ctx; ngx_quic_client_id_t *cid; ngx_quic_connection_t *qc; @@ -291,6 +292,16 @@ ngx_quic_set_path(ngx_connection_t *c, n /* packet from new path, drop current probe, if any */ + ctx = ngx_quic_get_send_ctx(qc, pkt->level); + + /* + * only accept highest-numbered packets to prevent connection id + * exhaustion by excessive probing packets from unknown paths + */ + if (pkt->pn != ctx->largest_pn) { + return NGX_DONE; + } + if (probe && ngx_quic_free_path(c, probe) != NGX_OK) { return NGX_ERROR; }