MINOR: quic: Anti-amplification implementation
A QUIC server MUST not send more than three times as many bytes as received
by clients before its address validation.
diff --git a/include/haproxy/xprt_quic-t.h b/include/haproxy/xprt_quic-t.h
index be3e8d0..8662945 100644
--- a/include/haproxy/xprt_quic-t.h
+++ b/include/haproxy/xprt_quic-t.h
@@ -606,6 +606,8 @@
/* Flag the packet number space as requiring an ACK frame to be sent. */
#define QUIC_FL_PKTNS_ACK_REQUIRED_BIT 0
#define QUIC_FL_PKTNS_ACK_REQUIRED (1UL << QUIC_FL_PKTNS_ACK_REQUIRED_BIT)
+
+#define QUIC_FL_CONN_ANTI_AMPLIFICATION_REACHED (1UL << 1)
struct quic_conn {
uint32_t version;
/* QUIC transport parameters TLS extension */
@@ -650,6 +652,8 @@
int rbuf;
/* Number of sent bytes. */
uint64_t bytes;
+ /* Number of bytes for prepared packets */
+ uint64_t prep_bytes;
/* The number of datagrams which may be sent
* when sending probe packets.
*/
diff --git a/src/xprt_quic.c b/src/xprt_quic.c
index 27b67ee..a5740db 100644
--- a/src/xprt_quic.c
+++ b/src/xprt_quic.c
@@ -644,9 +644,14 @@
goto out;
}
- /* XXX TODO: anti-amplification: the timer must be
+ /* anti-amplification: the timer must be
* cancelled for a server which reached the anti-amplification limit.
*/
+ if (qc->flags & QUIC_FL_CONN_ANTI_AMPLIFICATION_REACHED) {
+ TRACE_PROTO("anti-amplification reached", QUIC_EV_CONN_STIMER, ctx->conn);
+ qc->timer = TICK_ETERNITY;
+ goto out;
+ }
if (!qc->path->ifae_pkts && quic_peer_validated_addr(ctx)) {
TRACE_PROTO("timer cancellation", QUIC_EV_CONN_STIMER, ctx->conn);
@@ -2204,7 +2209,14 @@
if (!prv_pkt) {
/* Leave room for the datagram header */
pos += dg_headlen;
- end = pos + qc->path->mtu;
+ if (!quic_peer_validated_addr(ctx) && objt_listener(ctx->conn->target)) {
+ if (qc->tx.prep_bytes >= 3 * qc->rx.bytes)
+ qc->flags |= QUIC_FL_CONN_ANTI_AMPLIFICATION_REACHED;
+ end = pos + QUIC_MIN(qc->path->mtu, 3 * qc->rx.bytes - qc->tx.prep_bytes);
+ }
+ else {
+ end = pos + qc->path->mtu;
+ }
}
cur_pkt = qc_build_pkt(&pos, end, qel, qc, dglen, padding,
@@ -4496,6 +4508,7 @@
goto err;
}
+ qc->tx.prep_bytes += pkt->len;
/* Now that a correct packet is built, let us consume <*pos> buffer. */
*pos = end;
/* Attach the built packet to its tree. */