From c92337b9a5b80756ba6f1cfed4c71491e3fba625 Mon Sep 17 00:00:00 2001
From: Tatsuhiro Tsujikawa <tatsuhiro.t@gmail.com>
Date: Thu, 13 Feb 2020 21:58:32 +0900
Subject: [PATCH] Deal with delayed Handshake packets
Bring back the processing of Handshake packets. Doing so can reset
idle timer and reset PTO count which is useful to deal with packet
loss during handshake.
---
lib/ngtcp2_conn.c | 159 +++++++++++++++++++++++++++++++++++++--
tests/ngtcp2_conn_test.c | 6 +-
2 files changed, 154 insertions(+), 11 deletions(-)
diff --git a/lib/ngtcp2_conn.c b/lib/ngtcp2_conn.c
index d142856f..45f83b8d 100644
--- a/lib/ngtcp2_conn.c
+++ b/lib/ngtcp2_conn.c
@@ -6326,6 +6326,116 @@ static int conn_recv_non_probing_pkt_on_new_path(ngtcp2_conn *conn,
return 0;
}
+/*
+ * conn_recv_delayed_handshake_pkt processes the received Handshake
+ * packet which is received after handshake completed. This function
+ * does the minimal job, and its purpose is send acknowledgement of
+ * this packet to the peer. We assume that hd->type ==
+ * NGTCP2_PKT_HANDSHAKE.
+ *
+ * This function returns 0 if it succeeds, or one of the following
+ * negative error codes:
+ *
+ * NGTCP2_ERR_FRAME_ENCODING
+ * Frame is badly formatted; or frame type is unknown.
+ * NGTCP2_ERR_NOMEM
+ * Out of memory
+ * NGTCP2_ERR_DISCARD_PKT
+ * Packet was discarded.
+ * NGTCP2_ERR_ACK_FRAME
+ * ACK frame is malformed.
+ * NGTCP2_ERR_PROTO
+ * Frame that is not allowed in Handshake packet is received.
+ */
+static int
+conn_recv_delayed_handshake_pkt(ngtcp2_conn *conn, const ngtcp2_pkt_hd *hd,
+ size_t pktlen, const uint8_t *payload,
+ size_t payloadlen, ngtcp2_tstamp pkt_ts,
+ ngtcp2_tstamp ts) {
+ ngtcp2_ssize nread;
+ ngtcp2_max_frame mfr;
+ ngtcp2_frame *fr = &mfr.fr;
+ int rv;
+ int require_ack = 0;
+ ngtcp2_pktns *pktns;
+
+ assert(hd->type == NGTCP2_PKT_HANDSHAKE);
+
+ pktns = conn->hs_pktns;
+
+ if (payloadlen == 0) {
+ /* QUIC packet must contain at least one frame */
+ return NGTCP2_ERR_DISCARD_PKT;
+ }
+
+ ngtcp2_qlog_pkt_received_start(&conn->qlog, hd);
+
+ for (; payloadlen;) {
+ nread = ngtcp2_pkt_decode_frame(fr, payload, payloadlen);
+ if (nread < 0) {
+ return (int)nread;
+ }
+
+ payload += nread;
+ payloadlen -= (size_t)nread;
+
+ if (fr->type == NGTCP2_FRAME_ACK) {
+ fr->ack.ack_delay = 0;
+ fr->ack.ack_delay_unscaled = 0;
+ }
+
+ ngtcp2_log_rx_fr(&conn->log, hd, fr);
+
+ switch (fr->type) {
+ case NGTCP2_FRAME_ACK:
+ case NGTCP2_FRAME_ACK_ECN:
+ rv = conn_recv_ack(conn, pktns, &fr->ack, pkt_ts, ts);
+ if (rv != 0) {
+ return rv;
+ }
+ if (!conn->server) {
+ conn->flags |= NGTCP2_CONN_FLAG_SERVER_ADDR_VERIFIED;
+ }
+ break;
+ case NGTCP2_FRAME_PADDING:
+ break;
+ case NGTCP2_FRAME_CONNECTION_CLOSE:
+ conn_recv_connection_close(conn, &fr->connection_close);
+ break;
+ case NGTCP2_FRAME_CRYPTO:
+ case NGTCP2_FRAME_PING:
+ require_ack = 1;
+ break;
+ default:
+ return NGTCP2_ERR_PROTO;
+ }
+
+ ngtcp2_qlog_write_frame(&conn->qlog, fr);
+ }
+
+ ngtcp2_qlog_pkt_received_end(&conn->qlog, hd, pktlen);
+
+ rv = pktns_commit_recv_pkt_num(pktns, hd->pkt_num);
+ if (rv != 0) {
+ return rv;
+ }
+
+ if (require_ack && ++pktns->acktr.rx_npkt >= NGTCP2_NUM_IMMEDIATE_ACK_PKT) {
+ ngtcp2_acktr_immediate_ack(&pktns->acktr);
+ }
+
+ rv = ngtcp2_conn_sched_ack(conn, &pktns->acktr, hd->pkt_num, require_ack, ts);
+ if (rv != 0) {
+ return rv;
+ }
+
+ conn_restart_timer_on_read(conn, ts);
+
+ ngtcp2_qlog_metrics_updated(&conn->qlog, &conn->rcs, &conn->ccs);
+
+ return 0;
+}
+
/*
* conn_recv_pkt processes a packet contained in the buffer pointed by
* |pkt| of length |pktlen|. |pkt| may contain multiple QUIC packets.
@@ -6418,9 +6528,19 @@ static ngtcp2_ssize conn_recv_pkt(ngtcp2_conn *conn, const ngtcp2_path *path,
"delayed Initial packet was discarded");
return (ngtcp2_ssize)pktlen;
case NGTCP2_PKT_HANDSHAKE:
- ngtcp2_log_info(&conn->log, NGTCP2_LOG_EVENT_PKT,
- "delayed Handshake packet was discarded");
- return (ngtcp2_ssize)pktlen;
+ if (!conn->hs_pktns) {
+ ngtcp2_log_info(&conn->log, NGTCP2_LOG_EVENT_PKT,
+ "delayed Handshake packet was discarded");
+ return (ngtcp2_ssize)pktlen;
+ }
+
+ pktns = conn->hs_pktns;
+ ckm = pktns->crypto.rx.ckm;
+ hp_key = pktns->crypto.rx.hp_key;
+ hp_mask = conn->callbacks.hp_mask;
+ decrypt = conn->callbacks.decrypt;
+ aead_overhead = conn->crypto.aead_overhead;
+ break;
case NGTCP2_PKT_0RTT:
if (!conn->server || !conn->early.ckm) {
return NGTCP2_ERR_DISCARD_PKT;
@@ -6484,9 +6604,8 @@ static ngtcp2_ssize conn_recv_pkt(ngtcp2_conn *conn, const ngtcp2_path *path,
ngtcp2_log_rx_pkt_hd(&conn->log, &hd);
if (hd.flags & NGTCP2_PKT_FLAG_LONG_FORM) {
- assert(hd.type == NGTCP2_PKT_0RTT);
-
- if (!ngtcp2_cid_eq(&conn->rcid, &hd.dcid)) {
+ switch (hd.type) {
+ case NGTCP2_PKT_HANDSHAKE:
rv = conn_verify_dcid(conn, NULL, &hd);
if (rv != 0) {
if (ngtcp2_err_is_fatal(rv)) {
@@ -6496,6 +6615,23 @@ static ngtcp2_ssize conn_recv_pkt(ngtcp2_conn *conn, const ngtcp2_path *path,
"packet was ignored because of mismatched DCID");
return NGTCP2_ERR_DISCARD_PKT;
}
+ break;
+ case NGTCP2_PKT_0RTT:
+ if (!ngtcp2_cid_eq(&conn->rcid, &hd.dcid)) {
+ rv = conn_verify_dcid(conn, NULL, &hd);
+ if (rv != 0) {
+ if (ngtcp2_err_is_fatal(rv)) {
+ return rv;
+ }
+ ngtcp2_log_info(&conn->log, NGTCP2_LOG_EVENT_PKT,
+ "packet was ignored because of mismatched DCID");
+ return NGTCP2_ERR_DISCARD_PKT;
+ }
+ }
+ break;
+ default:
+ /* Unreachable */
+ assert(0);
}
} else {
rv = conn_verify_dcid(conn, &new_cid_used, &hd);
@@ -6595,7 +6731,16 @@ static ngtcp2_ssize conn_recv_pkt(ngtcp2_conn *conn, const ngtcp2_path *path,
return NGTCP2_ERR_DISCARD_PKT;
}
- if (!(hd.flags & NGTCP2_PKT_FLAG_LONG_FORM)) {
+ if (hd.flags & NGTCP2_PKT_FLAG_LONG_FORM) {
+ if (hd.type == NGTCP2_PKT_HANDSHAKE) {
+ rv = conn_recv_delayed_handshake_pkt(conn, &hd, pktlen, payload,
+ payloadlen, pkt_ts, ts);
+ if (rv < 0) {
+ return (ngtcp2_ssize)rv;
+ }
+ return (ngtcp2_ssize)pktlen;
+ }
+ } else {
conn->flags |= NGTCP2_CONN_FLAG_RECV_PROTECTED_PKT;
}
diff --git a/tests/ngtcp2_conn_test.c b/tests/ngtcp2_conn_test.c
index 0fcfd15f..f45dcb01 100644
--- a/tests/ngtcp2_conn_test.c
+++ b/tests/ngtcp2_conn_test.c
@@ -2391,7 +2391,6 @@ void test_ngtcp2_conn_recv_delayed_handshake_pkt(void) {
ngtcp2_frame fr;
int rv;
- /* Delayed Handshake packet is discarded */
setup_default_client(&conn);
fr.type = NGTCP2_FRAME_CRYPTO;
@@ -2406,7 +2405,7 @@ void test_ngtcp2_conn_recv_delayed_handshake_pkt(void) {
rv = ngtcp2_conn_read_pkt(conn, &null_path, buf, pktlen, 1);
CU_ASSERT(0 == rv);
- CU_ASSERT(0 == ngtcp2_ksl_len(&conn->hs_pktns->acktr.ents));
+ CU_ASSERT(1 == ngtcp2_ksl_len(&conn->hs_pktns->acktr.ents));
ngtcp2_conn_del(conn);
}
@@ -3699,10 +3698,9 @@ void test_ngtcp2_conn_recv_compound_pkt(void) {
CU_ASSERT(ackent->pkt_num == pkt_num);
- /* Handshake packet should be discarded */
it = ngtcp2_acktr_get(&conn->hs_pktns->acktr);
- CU_ASSERT(ngtcp2_ksl_it_end(&it));
+ CU_ASSERT(!ngtcp2_ksl_it_end(&it));
ngtcp2_conn_del(conn);
}
--
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