Adding upstream version 0.12.1+dfsg.upstream/0.12.1+dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1219 insertions, 0 deletions

diff --git a/lib/ngtcp2_qlog.c b/lib/ngtcp2_qlog.c
new file mode 100644
index 0000000..c83f885
--- /dev/null
+++ b/lib/ngtcp2_qlog.c
@@ -0,0 +1,1219 @@
+/*
+ * ngtcp2
+ *
+ * Copyright (c) 2019 ngtcp2 contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include "ngtcp2_qlog.h"
+
+#include <assert.h>
+
+#include "ngtcp2_str.h"
+#include "ngtcp2_vec.h"
+#include "ngtcp2_conv.h"
+#include "ngtcp2_net.h"
+#include "ngtcp2_unreachable.h"
+
+void ngtcp2_qlog_init(ngtcp2_qlog *qlog, ngtcp2_qlog_write write,
+                      ngtcp2_tstamp ts, void *user_data) {
+  qlog->write = write;
+  qlog->ts = qlog->last_ts = ts;
+  qlog->user_data = user_data;
+}
+
+#define write_verbatim(DEST, S) ngtcp2_cpymem((DEST), (S), sizeof(S) - 1)
+
+static uint8_t *write_string_impl(uint8_t *p, const uint8_t *data,
+                                  size_t datalen) {
+  *p++ = '"';
+  if (datalen) {
+    p = ngtcp2_cpymem(p, data, datalen);
+  }
+  *p++ = '"';
+  return p;
+}
+
+#define write_string(DEST, S)                                                  \
+  write_string_impl((DEST), (const uint8_t *)(S), sizeof(S) - 1)
+
+#define NGTCP2_LOWER_XDIGITS "0123456789abcdef"
+
+static uint8_t *write_hex(uint8_t *p, const uint8_t *data, size_t datalen) {
+  const uint8_t *b = data, *end = data + datalen;
+  *p++ = '"';
+  for (; b != end; ++b) {
+    *p++ = (uint8_t)NGTCP2_LOWER_XDIGITS[*b >> 4];
+    *p++ = (uint8_t)NGTCP2_LOWER_XDIGITS[*b & 0xf];
+  }
+  *p++ = '"';
+  return p;
+}
+
+static uint8_t *write_cid(uint8_t *p, const ngtcp2_cid *cid) {
+  return write_hex(p, cid->data, cid->datalen);
+}
+
+static uint8_t *write_number(uint8_t *p, uint64_t n) {
+  size_t nlen = 0;
+  uint64_t t;
+  uint8_t *res;
+
+  if (n == 0) {
+    *p++ = '0';
+    return p;
+  }
+  for (t = n; t; t /= 10, ++nlen)
+    ;
+  p += nlen;
+  res = p;
+  for (; n; n /= 10) {
+    *--p = (uint8_t)((n % 10) + '0');
+  }
+  return res;
+}
+
+static uint8_t *write_tstamp(uint8_t *p, ngtcp2_tstamp ts) {
+  return write_number(p, ts / NGTCP2_MILLISECONDS);
+}
+
+static uint8_t *write_duration(uint8_t *p, ngtcp2_duration duration) {
+  return write_number(p, duration / NGTCP2_MILLISECONDS);
+}
+
+static uint8_t *write_bool(uint8_t *p, int b) {
+  if (b) {
+    return ngtcp2_cpymem(p, "true", sizeof("true") - 1);
+  }
+  return ngtcp2_cpymem(p, "false", sizeof("false") - 1);
+}
+
+static uint8_t *write_pair_impl(uint8_t *p, const uint8_t *name, size_t namelen,
+                                const ngtcp2_vec *value) {
+  p = write_string_impl(p, name, namelen);
+  *p++ = ':';
+  return write_string_impl(p, value->base, value->len);
+}
+
+#define write_pair(DEST, NAME, VALUE)                                          \
+  write_pair_impl((DEST), (const uint8_t *)(NAME), sizeof(NAME) - 1, (VALUE))
+
+static uint8_t *write_pair_hex_impl(uint8_t *p, const uint8_t *name,
+                                    size_t namelen, const uint8_t *value,
+                                    size_t valuelen) {
+  p = write_string_impl(p, name, namelen);
+  *p++ = ':';
+  return write_hex(p, value, valuelen);
+}
+
+#define write_pair_hex(DEST, NAME, VALUE, VALUELEN)                            \
+  write_pair_hex_impl((DEST), (const uint8_t *)(NAME), sizeof(NAME) - 1,       \
+                      (VALUE), (VALUELEN))
+
+static uint8_t *write_pair_number_impl(uint8_t *p, const uint8_t *name,
+                                       size_t namelen, uint64_t value) {
+  p = write_string_impl(p, name, namelen);
+  *p++ = ':';
+  return write_number(p, value);
+}
+
+#define write_pair_number(DEST, NAME, VALUE)                                   \
+  write_pair_number_impl((DEST), (const uint8_t *)(NAME), sizeof(NAME) - 1,    \
+                         (VALUE))
+
+static uint8_t *write_pair_duration_impl(uint8_t *p, const uint8_t *name,
+                                         size_t namelen,
+                                         ngtcp2_duration duration) {
+  p = write_string_impl(p, name, namelen);
+  *p++ = ':';
+  return write_duration(p, duration);
+}
+
+#define write_pair_duration(DEST, NAME, VALUE)                                 \
+  write_pair_duration_impl((DEST), (const uint8_t *)(NAME), sizeof(NAME) - 1,  \
+                           (VALUE))
+
+static uint8_t *write_pair_tstamp_impl(uint8_t *p, const uint8_t *name,
+                                       size_t namelen, ngtcp2_tstamp ts) {
+  p = write_string_impl(p, name, namelen);
+  *p++ = ':';
+  return write_tstamp(p, ts);
+}
+
+#define write_pair_tstamp(DEST, NAME, VALUE)                                   \
+  write_pair_tstamp_impl((DEST), (const uint8_t *)(NAME), sizeof(NAME) - 1,    \
+                         (VALUE))
+
+static uint8_t *write_pair_bool_impl(uint8_t *p, const uint8_t *name,
+                                     size_t namelen, int b) {
+  p = write_string_impl(p, name, namelen);
+  *p++ = ':';
+  return write_bool(p, b);
+}
+
+#define write_pair_bool(DEST, NAME, VALUE)                                     \
+  write_pair_bool_impl((DEST), (const uint8_t *)(NAME), sizeof(NAME) - 1,      \
+                       (VALUE))
+
+static uint8_t *write_pair_cid_impl(uint8_t *p, const uint8_t *name,
+                                    size_t namelen, const ngtcp2_cid *cid) {
+  p = write_string_impl(p, name, namelen);
+  *p++ = ':';
+  return write_cid(p, cid);
+}
+
+#define write_pair_cid(DEST, NAME, VALUE)                                      \
+  write_pair_cid_impl((DEST), (const uint8_t *)(NAME), sizeof(NAME) - 1,       \
+                      (VALUE))
+
+#define ngtcp2_make_vec_lit(S)                                                 \
+  { (uint8_t *)(S), sizeof((S)) - 1 }
+
+static uint8_t *write_common_fields(uint8_t *p, const ngtcp2_cid *odcid) {
+  p = write_verbatim(
+      p, "\"common_fields\":{\"protocol_type\":[\"QUIC\"],\"time_format\":"
+         "\"relative\",\"reference_time\":0,\"group_id\":");
+  p = write_cid(p, odcid);
+  *p++ = '}';
+  return p;
+}
+
+static uint8_t *write_trace(uint8_t *p, int server, const ngtcp2_cid *odcid) {
+  p = write_verbatim(
+      p, "\"trace\":{\"vantage_point\":{\"name\":\"ngtcp2\",\"type\":");
+  if (server) {
+    p = write_string(p, "server");
+  } else {
+    p = write_string(p, "client");
+  }
+  p = write_verbatim(p, "},");
+  p = write_common_fields(p, odcid);
+  *p++ = '}';
+  return p;
+}
+
+void ngtcp2_qlog_start(ngtcp2_qlog *qlog, const ngtcp2_cid *odcid, int server) {
+  uint8_t buf[1024];
+  uint8_t *p = buf;
+
+  if (!qlog->write) {
+    return;
+  }
+
+  p = write_verbatim(
+      p, "\x1e{\"qlog_format\":\"JSON-SEQ\",\"qlog_version\":\"0.3\",");
+  p = write_trace(p, server, odcid);
+  p = write_verbatim(p, "}\n");
+
+  qlog->write(qlog->user_data, NGTCP2_QLOG_WRITE_FLAG_NONE, buf,
+              (size_t)(p - buf));
+}
+
+void ngtcp2_qlog_end(ngtcp2_qlog *qlog) {
+  uint8_t buf[1] = {0};
+
+  if (!qlog->write) {
+    return;
+  }
+
+  qlog->write(qlog->user_data, NGTCP2_QLOG_WRITE_FLAG_FIN, &buf, 0);
+}
+
+static ngtcp2_vec vec_pkt_type_initial = ngtcp2_make_vec_lit("initial");
+static ngtcp2_vec vec_pkt_type_handshake = ngtcp2_make_vec_lit("handshake");
+static ngtcp2_vec vec_pkt_type_0rtt = ngtcp2_make_vec_lit("0RTT");
+static ngtcp2_vec vec_pkt_type_1rtt = ngtcp2_make_vec_lit("1RTT");
+static ngtcp2_vec vec_pkt_type_retry = ngtcp2_make_vec_lit("retry");
+static ngtcp2_vec vec_pkt_type_version_negotiation =
+    ngtcp2_make_vec_lit("version_negotiation");
+static ngtcp2_vec vec_pkt_type_stateless_reset =
+    ngtcp2_make_vec_lit("stateless_reset");
+static ngtcp2_vec vec_pkt_type_unknown = ngtcp2_make_vec_lit("unknown");
+
+static const ngtcp2_vec *qlog_pkt_type(const ngtcp2_pkt_hd *hd) {
+  if (hd->flags & NGTCP2_PKT_FLAG_LONG_FORM) {
+    switch (hd->type) {
+    case NGTCP2_PKT_INITIAL:
+      return &vec_pkt_type_initial;
+    case NGTCP2_PKT_HANDSHAKE:
+      return &vec_pkt_type_handshake;
+    case NGTCP2_PKT_0RTT:
+      return &vec_pkt_type_0rtt;
+    case NGTCP2_PKT_RETRY:
+      return &vec_pkt_type_retry;
+    default:
+      return &vec_pkt_type_unknown;
+    }
+  }
+
+  switch (hd->type) {
+  case NGTCP2_PKT_VERSION_NEGOTIATION:
+    return &vec_pkt_type_version_negotiation;
+  case NGTCP2_PKT_STATELESS_RESET:
+    return &vec_pkt_type_stateless_reset;
+  case NGTCP2_PKT_1RTT:
+    return &vec_pkt_type_1rtt;
+  default:
+    return &vec_pkt_type_unknown;
+  }
+}
+
+static uint8_t *write_pkt_hd(uint8_t *p, const ngtcp2_pkt_hd *hd) {
+  /*
+   * {"packet_type":"version_negotiation","packet_number":"0000000000000000000","token":{"data":""}}
+   */
+#define NGTCP2_QLOG_PKT_HD_OVERHEAD 95
+
+  *p++ = '{';
+  p = write_pair(p, "packet_type", qlog_pkt_type(hd));
+  *p++ = ',';
+  p = write_pair_number(p, "packet_number", (uint64_t)hd->pkt_num);
+  if (hd->type == NGTCP2_PKT_INITIAL && hd->token.len) {
+    p = write_verbatim(p, ",\"token\":{");
+    p = write_pair_hex(p, "data", hd->token.base, hd->token.len);
+    *p++ = '}';
+  }
+  /* TODO Write DCIL and DCID */
+  /* TODO Write SCIL and SCID */
+  *p++ = '}';
+  return p;
+}
+
+static uint8_t *write_padding_frame(uint8_t *p, const ngtcp2_padding *fr) {
+  (void)fr;
+
+  /* {"frame_type":"padding"} */
+#define NGTCP2_QLOG_PADDING_FRAME_OVERHEAD 24
+
+  return write_verbatim(p, "{\"frame_type\":\"padding\"}");
+}
+
+static uint8_t *write_ping_frame(uint8_t *p, const ngtcp2_ping *fr) {
+  (void)fr;
+
+  /* {"frame_type":"ping"} */
+#define NGTCP2_QLOG_PING_FRAME_OVERHEAD 21
+
+  return write_verbatim(p, "{\"frame_type\":\"ping\"}");
+}
+
+static uint8_t *write_ack_frame(uint8_t *p, const ngtcp2_ack *fr) {
+  int64_t largest_ack, min_ack;
+  size_t i;
+  const ngtcp2_ack_range *range;
+
+  /*
+   * {"frame_type":"ack","ack_delay":0000000000000000000,"acked_ranges":[]}
+   *
+   * each range:
+   * [0000000000000000000,0000000000000000000],
+   *
+   * ecn:
+   * ,"ect1":0000000000000000000,"ect0":0000000000000000000,"ce":0000000000000000000
+   */
+#define NGTCP2_QLOG_ACK_FRAME_BASE_OVERHEAD 70
+#define NGTCP2_QLOG_ACK_FRAME_RANGE_OVERHEAD 42
+#define NGTCP2_QLOG_ACK_FRAME_ECN_OVERHEAD 79
+
+  p = write_verbatim(p, "{\"frame_type\":\"ack\",");
+  p = write_pair_duration(p, "ack_delay", fr->ack_delay_unscaled);
+  p = write_verbatim(p, ",\"acked_ranges\":[");
+
+  largest_ack = fr->largest_ack;
+  min_ack = fr->largest_ack - (int64_t)fr->first_ack_range;
+
+  *p++ = '[';
+  p = write_number(p, (uint64_t)min_ack);
+  if (largest_ack != min_ack) {
+    *p++ = ',';
+    p = write_number(p, (uint64_t)largest_ack);
+  }
+  *p++ = ']';
+
+  for (i = 0; i < fr->rangecnt; ++i) {
+    range = &fr->ranges[i];
+    largest_ack = min_ack - (int64_t)range->gap - 2;
+    min_ack = largest_ack - (int64_t)range->len;
+    *p++ = ',';
+    *p++ = '[';
+    p = write_number(p, (uint64_t)min_ack);
+    if (largest_ack != min_ack) {
+      *p++ = ',';
+      p = write_number(p, (uint64_t)largest_ack);
+    }
+    *p++ = ']';
+  }
+
+  *p++ = ']';
+
+  if (fr->type == NGTCP2_FRAME_ACK_ECN) {
+    *p++ = ',';
+    p = write_pair_number(p, "ect1", fr->ecn.ect1);
+    *p++ = ',';
+    p = write_pair_number(p, "ect0", fr->ecn.ect0);
+    *p++ = ',';
+    p = write_pair_number(p, "ce", fr->ecn.ce);
+  }
+
+  *p++ = '}';
+
+  return p;
+}
+
+static uint8_t *write_reset_stream_frame(uint8_t *p,
+                                         const ngtcp2_reset_stream *fr) {
+  /*
+   * {"frame_type":"reset_stream","stream_id":0000000000000000000,"error_code":0000000000000000000,"final_size":0000000000000000000}
+   */
+#define NGTCP2_QLOG_RESET_STREAM_FRAME_OVERHEAD 127
+
+  p = write_verbatim(p, "{\"frame_type\":\"reset_stream\",");
+  p = write_pair_number(p, "stream_id", (uint64_t)fr->stream_id);
+  *p++ = ',';
+  p = write_pair_number(p, "error_code", fr->app_error_code);
+  *p++ = ',';
+  p = write_pair_number(p, "final_size", fr->final_size);
+  *p++ = '}';
+
+  return p;
+}
+
+static uint8_t *write_stop_sending_frame(uint8_t *p,
+                                         const ngtcp2_stop_sending *fr) {
+  /*
+   * {"frame_type":"stop_sending","stream_id":0000000000000000000,"error_code":0000000000000000000}
+   */
+#define NGTCP2_QLOG_STOP_SENDING_FRAME_OVERHEAD 94
+
+  p = write_verbatim(p, "{\"frame_type\":\"stop_sending\",");
+  p = write_pair_number(p, "stream_id", (uint64_t)fr->stream_id);
+  *p++ = ',';
+  p = write_pair_number(p, "error_code", fr->app_error_code);
+  *p++ = '}';
+
+  return p;
+}
+
+static uint8_t *write_crypto_frame(uint8_t *p, const ngtcp2_crypto *fr) {
+  /*
+   * {"frame_type":"crypto","offset":0000000000000000000,"length":0000000000000000000}
+   */
+#define NGTCP2_QLOG_CRYPTO_FRAME_OVERHEAD 81
+
+  p = write_verbatim(p, "{\"frame_type\":\"crypto\",");
+  p = write_pair_number(p, "offset", fr->offset);
+  *p++ = ',';
+  p = write_pair_number(p, "length", ngtcp2_vec_len(fr->data, fr->datacnt));
+  *p++ = '}';
+
+  return p;
+}
+
+static uint8_t *write_new_token_frame(uint8_t *p, const ngtcp2_new_token *fr) {
+  /*
+   * {"frame_type":"new_token","length":0000000000000000000,"token":{"data":""}}
+   */
+#define NGTCP2_QLOG_NEW_TOKEN_FRAME_OVERHEAD 75
+
+  p = write_verbatim(p, "{\"frame_type\":\"new_token\",");
+  p = write_pair_number(p, "length", fr->token.len);
+  p = write_verbatim(p, ",\"token\":{");
+  p = write_pair_hex(p, "data", fr->token.base, fr->token.len);
+  *p++ = '}';
+  *p++ = '}';
+
+  return p;
+}
+
+static uint8_t *write_stream_frame(uint8_t *p, const ngtcp2_stream *fr) {
+  /*
+   * {"frame_type":"stream","stream_id":0000000000000000000,"offset":0000000000000000000,"length":0000000000000000000,"fin":true}
+   */
+#define NGTCP2_QLOG_STREAM_FRAME_OVERHEAD 124
+
+  p = write_verbatim(p, "{\"frame_type\":\"stream\",");
+  p = write_pair_number(p, "stream_id", (uint64_t)fr->stream_id);
+  *p++ = ',';
+  p = write_pair_number(p, "offset", fr->offset);
+  *p++ = ',';
+  p = write_pair_number(p, "length", ngtcp2_vec_len(fr->data, fr->datacnt));
+  if (fr->fin) {
+    *p++ = ',';
+    p = write_pair_bool(p, "fin", 1);
+  }
+  *p++ = '}';
+
+  return p;
+}
+
+static uint8_t *write_max_data_frame(uint8_t *p, const ngtcp2_max_data *fr) {
+  /*
+   * {"frame_type":"max_data","maximum":0000000000000000000}
+   */
+#define NGTCP2_QLOG_MAX_DATA_FRAME_OVERHEAD 55
+
+  p = write_verbatim(p, "{\"frame_type\":\"max_data\",");
+  p = write_pair_number(p, "maximum", fr->max_data);
+  *p++ = '}';
+
+  return p;
+}
+
+static uint8_t *write_max_stream_data_frame(uint8_t *p,
+                                            const ngtcp2_max_stream_data *fr) {
+  /*
+   * {"frame_type":"max_stream_data","stream_id":0000000000000000000,"maximum":0000000000000000000}
+   */
+#define NGTCP2_QLOG_MAX_STREAM_DATA_FRAME_OVERHEAD 94
+
+  p = write_verbatim(p, "{\"frame_type\":\"max_stream_data\",");
+  p = write_pair_number(p, "stream_id", (uint64_t)fr->stream_id);
+  *p++ = ',';
+  p = write_pair_number(p, "maximum", fr->max_stream_data);
+  *p++ = '}';
+
+  return p;
+}
+
+static uint8_t *write_max_streams_frame(uint8_t *p,
+                                        const ngtcp2_max_streams *fr) {
+  /*
+   * {"frame_type":"max_streams","stream_type":"unidirectional","maximum":0000000000000000000}
+   */
+#define NGTCP2_QLOG_MAX_STREAMS_FRAME_OVERHEAD 89
+
+  p = write_verbatim(p, "{\"frame_type\":\"max_streams\",\"stream_type\":");
+  if (fr->type == NGTCP2_FRAME_MAX_STREAMS_BIDI) {
+    p = write_string(p, "bidirectional");
+  } else {
+    p = write_string(p, "unidirectional");
+  }
+  *p++ = ',';
+  p = write_pair_number(p, "maximum", fr->max_streams);
+  *p++ = '}';
+
+  return p;
+}
+
+static uint8_t *write_data_blocked_frame(uint8_t *p,
+                                         const ngtcp2_data_blocked *fr) {
+  (void)fr;
+
+  /*
+   * {"frame_type":"data_blocked"}
+   */
+#define NGTCP2_QLOG_DATA_BLOCKED_FRAME_OVERHEAD 29
+
+  /* TODO log limit */
+
+  return write_verbatim(p, "{\"frame_type\":\"data_blocked\"}");
+}
+
+static uint8_t *
+write_stream_data_blocked_frame(uint8_t *p,
+                                const ngtcp2_stream_data_blocked *fr) {
+  (void)fr;
+
+  /*
+   * {"frame_type":"stream_data_blocked"}
+   */
+#define NGTCP2_QLOG_STREAM_DATA_BLOCKED_FRAME_OVERHEAD 36
+
+  /* TODO log limit */
+
+  return write_verbatim(p, "{\"frame_type\":\"stream_data_blocked\"}");
+}
+
+static uint8_t *write_streams_blocked_frame(uint8_t *p,
+                                            const ngtcp2_streams_blocked *fr) {
+  (void)fr;
+
+  /*
+   * {"frame_type":"streams_blocked"}
+   */
+#define NGTCP2_QLOG_STREAMS_BLOCKED_FRAME_OVERHEAD 32
+
+  /* TODO Log stream_type and limit */
+
+  return write_verbatim(p, "{\"frame_type\":\"streams_blocked\"}");
+}
+
+static uint8_t *
+write_new_connection_id_frame(uint8_t *p, const ngtcp2_new_connection_id *fr) {
+  /*
+   * {"frame_type":"new_connection_id","sequence_number":0000000000000000000,"retire_prior_to":0000000000000000000,"connection_id_length":0000000000000000000,"connection_id":"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx","stateless_reset_token":{"data":"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"}}
+   */
+#define NGTCP2_QLOG_NEW_CONNECTION_ID_FRAME_OVERHEAD 280
+
+  p = write_verbatim(p, "{\"frame_type\":\"new_connection_id\",");
+  p = write_pair_number(p, "sequence_number", fr->seq);
+  *p++ = ',';
+  p = write_pair_number(p, "retire_prior_to", fr->retire_prior_to);
+  *p++ = ',';
+  p = write_pair_number(p, "connection_id_length", fr->cid.datalen);
+  *p++ = ',';
+  p = write_pair_cid(p, "connection_id", &fr->cid);
+  p = write_verbatim(p, ",\"stateless_reset_token\":{");
+  p = write_pair_hex(p, "data", fr->stateless_reset_token,
+                     sizeof(fr->stateless_reset_token));
+  *p++ = '}';
+  *p++ = '}';
+
+  return p;
+}
+
+static uint8_t *
+write_retire_connection_id_frame(uint8_t *p,
+                                 const ngtcp2_retire_connection_id *fr) {
+  /*
+   * {"frame_type":"retire_connection_id","sequence_number":0000000000000000000}
+   */
+#define NGTCP2_QLOG_RETIRE_CONNECTION_ID_FRAME_OVERHEAD 75
+
+  p = write_verbatim(p, "{\"frame_type\":\"retire_connection_id\",");
+  p = write_pair_number(p, "sequence_number", fr->seq);
+  *p++ = '}';
+
+  return p;
+}
+
+static uint8_t *write_path_challenge_frame(uint8_t *p,
+                                           const ngtcp2_path_challenge *fr) {
+  /*
+   * {"frame_type":"path_challenge","data":"xxxxxxxxxxxxxxxx"}
+   */
+#define NGTCP2_QLOG_PATH_CHALLENGE_FRAME_OVERHEAD 57
+
+  p = write_verbatim(p, "{\"frame_type\":\"path_challenge\",");
+  p = write_pair_hex(p, "data", fr->data, sizeof(fr->data));
+  *p++ = '}';
+
+  return p;
+}
+
+static uint8_t *write_path_response_frame(uint8_t *p,
+                                          const ngtcp2_path_response *fr) {
+  /*
+   * {"frame_type":"path_response","data":"xxxxxxxxxxxxxxxx"}
+   */
+#define NGTCP2_QLOG_PATH_RESPONSE_FRAME_OVERHEAD 56
+
+  p = write_verbatim(p, "{\"frame_type\":\"path_response\",");
+  p = write_pair_hex(p, "data", fr->data, sizeof(fr->data));
+  *p++ = '}';
+
+  return p;
+}
+
+static uint8_t *
+write_connection_close_frame(uint8_t *p, const ngtcp2_connection_close *fr) {
+  /*
+   * {"frame_type":"connection_close","error_space":"application","error_code":0000000000000000000,"raw_error_code":0000000000000000000}
+   */
+#define NGTCP2_QLOG_CONNECTION_CLOSE_FRAME_OVERHEAD 131
+
+  p = write_verbatim(p,
+                     "{\"frame_type\":\"connection_close\",\"error_space\":");
+  if (fr->type == NGTCP2_FRAME_CONNECTION_CLOSE) {
+    p = write_string(p, "transport");
+  } else {
+    p = write_string(p, "application");
+  }
+  *p++ = ',';
+  p = write_pair_number(p, "error_code", fr->error_code);
+  *p++ = ',';
+  p = write_pair_number(p, "raw_error_code", fr->error_code);
+  /* TODO Write reason by escaping non-printables */
+  /* TODO Write trigger_frame_type */
+  *p++ = '}';
+
+  return p;
+}
+
+static uint8_t *write_handshake_done_frame(uint8_t *p,
+                                           const ngtcp2_handshake_done *fr) {
+  (void)fr;
+
+  /*
+   * {"frame_type":"handshake_done"}
+   */
+#define NGTCP2_QLOG_HANDSHAKE_DONE_FRAME_OVERHEAD 31
+
+  return write_verbatim(p, "{\"frame_type\":\"handshake_done\"}");
+}
+
+static uint8_t *write_datagram_frame(uint8_t *p, const ngtcp2_datagram *fr) {
+  /*
+   * {"frame_type":"datagram","length":0000000000000000000}
+   */
+#define NGTCP2_QLOG_DATAGRAM_FRAME_OVERHEAD 54
+
+  p = write_verbatim(p, "{\"frame_type\":\"datagram\",");
+  p = write_pair_number(p, "length", ngtcp2_vec_len(fr->data, fr->datacnt));
+  *p++ = '}';
+
+  return p;
+}
+
+static uint8_t *qlog_write_time(ngtcp2_qlog *qlog, uint8_t *p) {
+  return write_pair_tstamp(p, "time", qlog->last_ts - qlog->ts);
+}
+
+static void qlog_pkt_write_start(ngtcp2_qlog *qlog, int sent) {
+  uint8_t *p;
+
+  if (!qlog->write) {
+    return;
+  }
+
+  ngtcp2_buf_reset(&qlog->buf);
+  p = qlog->buf.last;
+
+  *p++ = '\x1e';
+  *p++ = '{';
+  p = qlog_write_time(qlog, p);
+  p = write_verbatim(p, ",\"name\":");
+  if (sent) {
+    p = write_string(p, "transport:packet_sent");
+  } else {
+    p = write_string(p, "transport:packet_received");
+  }
+  p = write_verbatim(p, ",\"data\":{\"frames\":[");
+  qlog->buf.last = p;
+}
+
+static void qlog_pkt_write_end(ngtcp2_qlog *qlog, const ngtcp2_pkt_hd *hd,
+                               size_t pktlen) {
+  uint8_t *p = qlog->buf.last;
+
+  if (!qlog->write) {
+    return;
+  }
+
+  /*
+   * ],"header":,"raw":{"length":0000000000000000000}}}
+   *
+   * plus, terminating LF
+   */
+#define NGTCP2_QLOG_PKT_WRITE_END_OVERHEAD                                     \
+  (1 + 50 + NGTCP2_QLOG_PKT_HD_OVERHEAD)
+
+  if (ngtcp2_buf_left(&qlog->buf) <
+      NGTCP2_QLOG_PKT_WRITE_END_OVERHEAD + hd->token.len * 2) {
+    return;
+  }
+
+  assert(ngtcp2_buf_len(&qlog->buf));
+
+  /* Eat last ',' */
+  if (*(p - 1) == ',') {
+    --p;
+  }
+
+  p = write_verbatim(p, "],\"header\":");
+  p = write_pkt_hd(p, hd);
+  p = write_verbatim(p, ",\"raw\":{\"length\":");
+  p = write_number(p, pktlen);
+  p = write_verbatim(p, "}}}\n");
+
+  qlog->buf.last = p;
+
+  qlog->write(qlog->user_data, NGTCP2_QLOG_WRITE_FLAG_NONE, qlog->buf.pos,
+              ngtcp2_buf_len(&qlog->buf));
+}
+
+void ngtcp2_qlog_write_frame(ngtcp2_qlog *qlog, const ngtcp2_frame *fr) {
+  uint8_t *p = qlog->buf.last;
+
+  if (!qlog->write) {
+    return;
+  }
+
+  switch (fr->type) {
+  case NGTCP2_FRAME_PADDING:
+    if (ngtcp2_buf_left(&qlog->buf) < NGTCP2_QLOG_PADDING_FRAME_OVERHEAD + 1) {
+      return;
+    }
+    p = write_padding_frame(p, &fr->padding);
+    break;
+  case NGTCP2_FRAME_PING:
+    if (ngtcp2_buf_left(&qlog->buf) < NGTCP2_QLOG_PING_FRAME_OVERHEAD + 1) {
+      return;
+    }
+    p = write_ping_frame(p, &fr->ping);
+    break;
+  case NGTCP2_FRAME_ACK:
+  case NGTCP2_FRAME_ACK_ECN:
+    if (ngtcp2_buf_left(&qlog->buf) <
+        NGTCP2_QLOG_ACK_FRAME_BASE_OVERHEAD +
+            (size_t)(fr->type == NGTCP2_FRAME_ACK_ECN
+                         ? NGTCP2_QLOG_ACK_FRAME_ECN_OVERHEAD
+                         : 0) +
+            NGTCP2_QLOG_ACK_FRAME_RANGE_OVERHEAD * (1 + fr->ack.rangecnt) + 1) {
+      return;
+    }
+    p = write_ack_frame(p, &fr->ack);
+    break;
+  case NGTCP2_FRAME_RESET_STREAM:
+    if (ngtcp2_buf_left(&qlog->buf) <
+        NGTCP2_QLOG_RESET_STREAM_FRAME_OVERHEAD + 1) {
+      return;
+    }
+    p = write_reset_stream_frame(p, &fr->reset_stream);
+    break;
+  case NGTCP2_FRAME_STOP_SENDING:
+    if (ngtcp2_buf_left(&qlog->buf) <
+        NGTCP2_QLOG_STOP_SENDING_FRAME_OVERHEAD + 1) {
+      return;
+    }
+    p = write_stop_sending_frame(p, &fr->stop_sending);
+    break;
+  case NGTCP2_FRAME_CRYPTO:
+    if (ngtcp2_buf_left(&qlog->buf) < NGTCP2_QLOG_CRYPTO_FRAME_OVERHEAD + 1) {
+      return;
+    }
+    p = write_crypto_frame(p, &fr->crypto);
+    break;
+  case NGTCP2_FRAME_NEW_TOKEN:
+    if (ngtcp2_buf_left(&qlog->buf) < NGTCP2_QLOG_NEW_TOKEN_FRAME_OVERHEAD +
+                                          fr->new_token.token.len * 2 + 1) {
+      return;
+    }
+    p = write_new_token_frame(p, &fr->new_token);
+    break;
+  case NGTCP2_FRAME_STREAM:
+    if (ngtcp2_buf_left(&qlog->buf) < NGTCP2_QLOG_STREAM_FRAME_OVERHEAD + 1) {
+      return;
+    }
+    p = write_stream_frame(p, &fr->stream);
+    break;
+  case NGTCP2_FRAME_MAX_DATA:
+    if (ngtcp2_buf_left(&qlog->buf) < NGTCP2_QLOG_MAX_DATA_FRAME_OVERHEAD + 1) {
+      return;
+    }
+    p = write_max_data_frame(p, &fr->max_data);
+    break;
+  case NGTCP2_FRAME_MAX_STREAM_DATA:
+    if (ngtcp2_buf_left(&qlog->buf) <
+        NGTCP2_QLOG_MAX_STREAM_DATA_FRAME_OVERHEAD + 1) {
+      return;
+    }
+    p = write_max_stream_data_frame(p, &fr->max_stream_data);
+    break;
+  case NGTCP2_FRAME_MAX_STREAMS_BIDI:
+  case NGTCP2_FRAME_MAX_STREAMS_UNI:
+    if (ngtcp2_buf_left(&qlog->buf) <
+        NGTCP2_QLOG_MAX_STREAMS_FRAME_OVERHEAD + 1) {
+      return;
+    }
+    p = write_max_streams_frame(p, &fr->max_streams);
+    break;
+  case NGTCP2_FRAME_DATA_BLOCKED:
+    if (ngtcp2_buf_left(&qlog->buf) <
+        NGTCP2_QLOG_DATA_BLOCKED_FRAME_OVERHEAD + 1) {
+      return;
+    }
+    p = write_data_blocked_frame(p, &fr->data_blocked);
+    break;
+  case NGTCP2_FRAME_STREAM_DATA_BLOCKED:
+    if (ngtcp2_buf_left(&qlog->buf) <
+        NGTCP2_QLOG_STREAM_DATA_BLOCKED_FRAME_OVERHEAD + 1) {
+      return;
+    }
+    p = write_stream_data_blocked_frame(p, &fr->stream_data_blocked);
+    break;
+  case NGTCP2_FRAME_STREAMS_BLOCKED_BIDI:
+  case NGTCP2_FRAME_STREAMS_BLOCKED_UNI:
+    if (ngtcp2_buf_left(&qlog->buf) <
+        NGTCP2_QLOG_STREAMS_BLOCKED_FRAME_OVERHEAD + 1) {
+      return;
+    }
+    p = write_streams_blocked_frame(p, &fr->streams_blocked);
+    break;
+  case NGTCP2_FRAME_NEW_CONNECTION_ID:
+    if (ngtcp2_buf_left(&qlog->buf) <
+        NGTCP2_QLOG_NEW_CONNECTION_ID_FRAME_OVERHEAD + 1) {
+      return;
+    }
+    p = write_new_connection_id_frame(p, &fr->new_connection_id);
+    break;
+  case NGTCP2_FRAME_RETIRE_CONNECTION_ID:
+    if (ngtcp2_buf_left(&qlog->buf) <
+        NGTCP2_QLOG_RETIRE_CONNECTION_ID_FRAME_OVERHEAD + 1) {
+      return;
+    }
+    p = write_retire_connection_id_frame(p, &fr->retire_connection_id);
+    break;
+  case NGTCP2_FRAME_PATH_CHALLENGE:
+    if (ngtcp2_buf_left(&qlog->buf) <
+        NGTCP2_QLOG_PATH_CHALLENGE_FRAME_OVERHEAD + 1) {
+      return;
+    }
+    p = write_path_challenge_frame(p, &fr->path_challenge);
+    break;
+  case NGTCP2_FRAME_PATH_RESPONSE:
+    if (ngtcp2_buf_left(&qlog->buf) <
+        NGTCP2_QLOG_PATH_RESPONSE_FRAME_OVERHEAD + 1) {
+      return;
+    }
+    p = write_path_response_frame(p, &fr->path_response);
+    break;
+  case NGTCP2_FRAME_CONNECTION_CLOSE:
+  case NGTCP2_FRAME_CONNECTION_CLOSE_APP:
+    if (ngtcp2_buf_left(&qlog->buf) <
+        NGTCP2_QLOG_CONNECTION_CLOSE_FRAME_OVERHEAD + 1) {
+      return;
+    }
+    p = write_connection_close_frame(p, &fr->connection_close);
+    break;
+  case NGTCP2_FRAME_HANDSHAKE_DONE:
+    if (ngtcp2_buf_left(&qlog->buf) <
+        NGTCP2_QLOG_HANDSHAKE_DONE_FRAME_OVERHEAD + 1) {
+      return;
+    }
+    p = write_handshake_done_frame(p, &fr->handshake_done);
+    break;
+  case NGTCP2_FRAME_DATAGRAM:
+  case NGTCP2_FRAME_DATAGRAM_LEN:
+    if (ngtcp2_buf_left(&qlog->buf) < NGTCP2_QLOG_DATAGRAM_FRAME_OVERHEAD + 1) {
+      return;
+    }
+    p = write_datagram_frame(p, &fr->datagram);
+    break;
+  default:
+    ngtcp2_unreachable();
+  }
+
+  *p++ = ',';
+
+  qlog->buf.last = p;
+}
+
+void ngtcp2_qlog_pkt_received_start(ngtcp2_qlog *qlog) {
+  qlog_pkt_write_start(qlog, /* sent = */ 0);
+}
+
+void ngtcp2_qlog_pkt_received_end(ngtcp2_qlog *qlog, const ngtcp2_pkt_hd *hd,
+                                  size_t pktlen) {
+  qlog_pkt_write_end(qlog, hd, pktlen);
+}
+
+void ngtcp2_qlog_pkt_sent_start(ngtcp2_qlog *qlog) {
+  qlog_pkt_write_start(qlog, /* sent = */ 1);
+}
+
+void ngtcp2_qlog_pkt_sent_end(ngtcp2_qlog *qlog, const ngtcp2_pkt_hd *hd,
+                              size_t pktlen) {
+  qlog_pkt_write_end(qlog, hd, pktlen);
+}
+
+void ngtcp2_qlog_parameters_set_transport_params(
+    ngtcp2_qlog *qlog, const ngtcp2_transport_params *params, int server,
+    ngtcp2_qlog_side side) {
+  uint8_t buf[1024];
+  uint8_t *p = buf;
+  const ngtcp2_preferred_addr *paddr;
+  const ngtcp2_sockaddr_in *sa_in;
+  const ngtcp2_sockaddr_in6 *sa_in6;
+
+  if (!qlog->write) {
+    return;
+  }
+
+  *p++ = '\x1e';
+  *p++ = '{';
+  p = qlog_write_time(qlog, p);
+  p = write_verbatim(
+      p, ",\"name\":\"transport:parameters_set\",\"data\":{\"owner\":");
+
+  if (side == NGTCP2_QLOG_SIDE_LOCAL) {
+    p = write_string(p, "local");
+  } else {
+    p = write_string(p, "remote");
+  }
+
+  *p++ = ',';
+  p = write_pair_cid(p, "initial_source_connection_id", &params->initial_scid);
+  *p++ = ',';
+  if (side == (server ? NGTCP2_QLOG_SIDE_LOCAL : NGTCP2_QLOG_SIDE_REMOTE)) {
+    p = write_pair_cid(p, "original_destination_connection_id",
+                       &params->original_dcid);
+    *p++ = ',';
+  }
+  if (params->retry_scid_present) {
+    p = write_pair_cid(p, "retry_source_connection_id", &params->retry_scid);
+    *p++ = ',';
+  }
+  if (params->stateless_reset_token_present) {
+    p = write_verbatim(p, "\"stateless_reset_token\":{");
+    p = write_pair_hex(p, "data", params->stateless_reset_token,
+                       sizeof(params->stateless_reset_token));
+    *p++ = '}';
+    *p++ = ',';
+  }
+  p = write_pair_bool(p, "disable_active_migration",
+                      params->disable_active_migration);
+  *p++ = ',';
+  p = write_pair_duration(p, "max_idle_timeout", params->max_idle_timeout);
+  *p++ = ',';
+  p = write_pair_number(p, "max_udp_payload_size",
+                        params->max_udp_payload_size);
+  *p++ = ',';
+  p = write_pair_number(p, "ack_delay_exponent", params->ack_delay_exponent);
+  *p++ = ',';
+  p = write_pair_duration(p, "max_ack_delay", params->max_ack_delay);
+  *p++ = ',';
+  p = write_pair_number(p, "active_connection_id_limit",
+                        params->active_connection_id_limit);
+  *p++ = ',';
+  p = write_pair_number(p, "initial_max_data", params->initial_max_data);
+  *p++ = ',';
+  p = write_pair_number(p, "initial_max_stream_data_bidi_local",
+                        params->initial_max_stream_data_bidi_local);
+  *p++ = ',';
+  p = write_pair_number(p, "initial_max_stream_data_bidi_remote",
+                        params->initial_max_stream_data_bidi_remote);
+  *p++ = ',';
+  p = write_pair_number(p, "initial_max_stream_data_uni",
+                        params->initial_max_stream_data_uni);
+  *p++ = ',';
+  p = write_pair_number(p, "initial_max_streams_bidi",
+                        params->initial_max_streams_bidi);
+  *p++ = ',';
+  p = write_pair_number(p, "initial_max_streams_uni",
+                        params->initial_max_streams_uni);
+  if (params->preferred_address_present) {
+    *p++ = ',';
+    paddr = &params->preferred_address;
+    p = write_string(p, "preferred_address");
+    *p++ = ':';
+    *p++ = '{';
+
+    if (paddr->ipv4_present) {
+      sa_in = &paddr->ipv4;
+
+      p = write_pair_hex(p, "ip_v4", (const uint8_t *)&sa_in->sin_addr,
+                         sizeof(sa_in->sin_addr));
+      *p++ = ',';
+      p = write_pair_number(p, "port_v4", ngtcp2_ntohs(sa_in->sin_port));
+      *p++ = ',';
+    }
+
+    if (paddr->ipv6_present) {
+      sa_in6 = &paddr->ipv6;
+
+      p = write_pair_hex(p, "ip_v6", (const uint8_t *)&sa_in6->sin6_addr,
+                         sizeof(sa_in6->sin6_addr));
+      *p++ = ',';
+      p = write_pair_number(p, "port_v6", ngtcp2_ntohs(sa_in6->sin6_port));
+      *p++ = ',';
+    }
+
+    p = write_pair_cid(p, "connection_id", &paddr->cid);
+    p = write_verbatim(p, ",\"stateless_reset_token\":{");
+    p = write_pair_hex(p, "data", paddr->stateless_reset_token,
+                       sizeof(paddr->stateless_reset_token));
+    *p++ = '}';
+    *p++ = '}';
+  }
+  *p++ = ',';
+  p = write_pair_number(p, "max_datagram_frame_size",
+                        params->max_datagram_frame_size);
+  *p++ = ',';
+  p = write_pair_bool(p, "grease_quic_bit", params->grease_quic_bit);
+  p = write_verbatim(p, "}}\n");
+
+  qlog->write(qlog->user_data, NGTCP2_QLOG_WRITE_FLAG_NONE, buf,
+              (size_t)(p - buf));
+}
+
+void ngtcp2_qlog_metrics_updated(ngtcp2_qlog *qlog,
+                                 const ngtcp2_conn_stat *cstat) {
+  uint8_t buf[1024];
+  uint8_t *p = buf;
+
+  if (!qlog->write) {
+    return;
+  }
+
+  *p++ = '\x1e';
+  *p++ = '{';
+  p = qlog_write_time(qlog, p);
+  p = write_verbatim(p, ",\"name\":\"recovery:metrics_updated\",\"data\":{");
+
+  if (cstat->min_rtt != UINT64_MAX) {
+    p = write_pair_duration(p, "min_rtt", cstat->min_rtt);
+    *p++ = ',';
+  }
+  p = write_pair_duration(p, "smoothed_rtt", cstat->smoothed_rtt);
+  *p++ = ',';
+  p = write_pair_duration(p, "latest_rtt", cstat->latest_rtt);
+  *p++ = ',';
+  p = write_pair_duration(p, "rtt_variance", cstat->rttvar);
+  *p++ = ',';
+  p = write_pair_number(p, "pto_count", cstat->pto_count);
+  *p++ = ',';
+  p = write_pair_number(p, "congestion_window", cstat->cwnd);
+  *p++ = ',';
+  p = write_pair_number(p, "bytes_in_flight", cstat->bytes_in_flight);
+  if (cstat->ssthresh != UINT64_MAX) {
+    *p++ = ',';
+    p = write_pair_number(p, "ssthresh", cstat->ssthresh);
+  }
+
+  p = write_verbatim(p, "}}\n");
+
+  qlog->write(qlog->user_data, NGTCP2_QLOG_WRITE_FLAG_NONE, buf,
+              (size_t)(p - buf));
+}
+
+void ngtcp2_qlog_pkt_lost(ngtcp2_qlog *qlog, ngtcp2_rtb_entry *ent) {
+  uint8_t buf[256];
+  uint8_t *p = buf;
+  ngtcp2_pkt_hd hd = {0};
+
+  if (!qlog->write) {
+    return;
+  }
+
+  *p++ = '\x1e';
+  *p++ = '{';
+  p = qlog_write_time(qlog, p);
+  p = write_verbatim(
+      p, ",\"name\":\"recovery:packet_lost\",\"data\":{\"header\":");
+
+  hd.type = ent->hd.type;
+  hd.flags = ent->hd.flags;
+  hd.pkt_num = ent->hd.pkt_num;
+
+  p = write_pkt_hd(p, &hd);
+  p = write_verbatim(p, "}}\n");
+
+  qlog->write(qlog->user_data, NGTCP2_QLOG_WRITE_FLAG_NONE, buf,
+              (size_t)(p - buf));
+}
+
+void ngtcp2_qlog_retry_pkt_received(ngtcp2_qlog *qlog, const ngtcp2_pkt_hd *hd,
+                                    const ngtcp2_pkt_retry *retry) {
+  uint8_t rawbuf[1024];
+  ngtcp2_buf buf;
+
+  if (!qlog->write) {
+    return;
+  }
+
+  ngtcp2_buf_init(&buf, rawbuf, sizeof(rawbuf));
+
+  *buf.last++ = '\x1e';
+  *buf.last++ = '{';
+  buf.last = qlog_write_time(qlog, buf.last);
+  buf.last = write_verbatim(
+      buf.last,
+      ",\"name\":\"transport:packet_received\",\"data\":{\"header\":");
+
+  if (ngtcp2_buf_left(&buf) <
+      NGTCP2_QLOG_PKT_HD_OVERHEAD + hd->token.len * 2 +
+          sizeof(",\"retry_token\":{\"data\":\"\"}}}\n") - 1 +
+          retry->token.len * 2) {
+    return;
+  }
+
+  buf.last = write_pkt_hd(buf.last, hd);
+  buf.last = write_verbatim(buf.last, ",\"retry_token\":{");
+  buf.last =
+      write_pair_hex(buf.last, "data", retry->token.base, retry->token.len);
+  buf.last = write_verbatim(buf.last, "}}}\n");
+
+  qlog->write(qlog->user_data, NGTCP2_QLOG_WRITE_FLAG_NONE, buf.pos,
+              ngtcp2_buf_len(&buf));
+}
+
+void ngtcp2_qlog_stateless_reset_pkt_received(
+    ngtcp2_qlog *qlog, const ngtcp2_pkt_stateless_reset *sr) {
+  uint8_t buf[256];
+  uint8_t *p = buf;
+  ngtcp2_pkt_hd hd = {0};
+
+  if (!qlog->write) {
+    return;
+  }
+
+  hd.type = NGTCP2_PKT_STATELESS_RESET;
+
+  *p++ = '\x1e';
+  *p++ = '{';
+  p = qlog_write_time(qlog, p);
+  p = write_verbatim(
+      p, ",\"name\":\"transport:packet_received\",\"data\":{\"header\":");
+  p = write_pkt_hd(p, &hd);
+  *p++ = ',';
+  p = write_pair_hex(p, "stateless_reset_token", sr->stateless_reset_token,
+                     NGTCP2_STATELESS_RESET_TOKENLEN);
+  p = write_verbatim(p, "}}\n");
+
+  qlog->write(qlog->user_data, NGTCP2_QLOG_WRITE_FLAG_NONE, buf,
+              (size_t)(p - buf));
+}
+
+void ngtcp2_qlog_version_negotiation_pkt_received(ngtcp2_qlog *qlog,
+                                                  const ngtcp2_pkt_hd *hd,
+                                                  const uint32_t *sv,
+                                                  size_t nsv) {
+  uint8_t rawbuf[512];
+  ngtcp2_buf buf;
+  size_t i;
+  uint32_t v;
+
+  if (!qlog->write) {
+    return;
+  }
+
+  ngtcp2_buf_init(&buf, rawbuf, sizeof(rawbuf));
+
+  *buf.last++ = '\x1e';
+  *buf.last++ = '{';
+  buf.last = qlog_write_time(qlog, buf.last);
+  buf.last = write_verbatim(
+      buf.last,
+      ",\"name\":\"transport:packet_received\",\"data\":{\"header\":");
+  buf.last = write_pkt_hd(buf.last, hd);
+  buf.last = write_verbatim(buf.last, ",\"supported_versions\":[");
+
+  if (nsv) {
+    if (ngtcp2_buf_left(&buf) <
+        (sizeof("\"xxxxxxxx\",") - 1) * nsv - 1 + sizeof("]}}\n") - 1) {
+      return;
+    }
+
+    v = ngtcp2_htonl(sv[0]);
+    buf.last = write_hex(buf.last, (const uint8_t *)&v, sizeof(v));
+
+    for (i = 1; i < nsv; ++i) {
+      *buf.last++ = ',';
+      v = ngtcp2_htonl(sv[i]);
+      buf.last = write_hex(buf.last, (const uint8_t *)&v, sizeof(v));
+    }
+  }
+
+  buf.last = write_verbatim(buf.last, "]}}\n");
+
+  qlog->write(qlog->user_data, NGTCP2_QLOG_WRITE_FLAG_NONE, buf.pos,
+              ngtcp2_buf_len(&buf));
+}