/*
 * ngtcp2
 *
 * Copyright (c) 2018 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_log.h"

#include <stdio.h>
#ifdef HAVE_UNISTD_H
#  include <unistd.h>
#endif /* defined(HAVE_UNISTD_H) */
#include <assert.h>
#include <string.h>

#include "ngtcp2_str.h"
#include "ngtcp2_vec.h"
#include "ngtcp2_macro.h"
#include "ngtcp2_conv.h"
#include "ngtcp2_unreachable.h"
#include "ngtcp2_net.h"

void ngtcp2_log_init(ngtcp2_log *log, const ngtcp2_cid *scid,
                     ngtcp2_log_write log_write, ngtcp2_printf log_printf,
                     char *buf, ngtcp2_tstamp ts, void *user_data) {
  if (scid) {
    *ngtcp2_encode_hex((uint8_t *)log->scid, scid->data, scid->datalen) = '\0';
  } else {
    log->scid[0] = '\0';
  }
  log->log_write = log_write;
  log->log_printf = log_printf;
  log->events = 0xFF;
  log->ts = log->last_ts = ts;
  log->user_data = user_data;
  log->buf = buf;
}

/*
 * # Log header
 *
 * <LEVEL><TIMESTAMP> <SCID> <EVENT>
 *
 * <LEVEL>:
 *   Log level.  I=Info, W=Warning, E=Error
 *
 * <TIMESTAMP>:
 *   Timestamp relative to ngtcp2_log.ts field in milliseconds
 *   resolution.
 *
 * <SCID>:
 *   Source Connection ID in hex string.
 *
 * <EVENT>:
 *   Event.  See ngtcp2_log_event.
 *
 * # Frame event
 *
 * <DIR> <PKN> <PKTNAME> <FRAMENAME>(<FRAMETYPE>)
 *
 * <DIR>:
 *   Flow direction.  tx=transmission, rx=reception
 *
 * <PKN>:
 *   Packet number.
 *
 * <PKTNAME>:
 *   Packet name.  (e.g., Initial, Handshake, 1RTT)
 *
 * <FRAMENAME>:
 *   Frame name.  (e.g., STREAM, ACK, PING)
 *
 * <FRAMETYPE>:
 *   Frame type in hex string.
 */

#define NGTCP2_LOG_TP "remote transport_parameters"

#define NGTCP2_LOG_PKT(DIR, HD) (DIR), " ", (HD)->pkt_num, " ", strpkttype((HD))

static const char *strerrorcode(uint64_t error_code) {
  switch (error_code) {
  case NGTCP2_NO_ERROR:
    return "NO_ERROR";
  case NGTCP2_INTERNAL_ERROR:
    return "INTERNAL_ERROR";
  case NGTCP2_CONNECTION_REFUSED:
    return "CONNECTION_REFUSED";
  case NGTCP2_FLOW_CONTROL_ERROR:
    return "FLOW_CONTROL_ERROR";
  case NGTCP2_STREAM_LIMIT_ERROR:
    return "STREAM_LIMIT_ERROR";
  case NGTCP2_STREAM_STATE_ERROR:
    return "STREAM_STATE_ERROR";
  case NGTCP2_FINAL_SIZE_ERROR:
    return "FINAL_SIZE_ERROR";
  case NGTCP2_FRAME_ENCODING_ERROR:
    return "FRAME_ENCODING_ERROR";
  case NGTCP2_TRANSPORT_PARAMETER_ERROR:
    return "TRANSPORT_PARAMETER_ERROR";
  case NGTCP2_CONNECTION_ID_LIMIT_ERROR:
    return "CONNECTION_ID_LIMIT_ERROR";
  case NGTCP2_PROTOCOL_VIOLATION:
    return "PROTOCOL_VIOLATION";
  case NGTCP2_INVALID_TOKEN:
    return "INVALID_TOKEN";
  case NGTCP2_APPLICATION_ERROR:
    return "APPLICATION_ERROR";
  case NGTCP2_CRYPTO_BUFFER_EXCEEDED:
    return "CRYPTO_BUFFER_EXCEEDED";
  case NGTCP2_KEY_UPDATE_ERROR:
    return "KEY_UPDATE_ERROR";
  case NGTCP2_AEAD_LIMIT_REACHED:
    return "AEAD_LIMIT_REACHED";
  case NGTCP2_NO_VIABLE_PATH:
    return "NO_VIABLE_PATH";
  case NGTCP2_VERSION_NEGOTIATION_ERROR:
    return "VERSION_NEGOTIATION_ERROR";
  default:
    if (0x100U <= error_code && error_code <= 0x1FFU) {
      return "CRYPTO_ERROR";
    }
    return "(unknown)";
  }
}

static const char *strapperrorcode(uint64_t app_error_code) {
  (void)app_error_code;
  return "(unknown)";
}

static const char *strpkttype(const ngtcp2_pkt_hd *hd) {
  switch (hd->type) {
  case NGTCP2_PKT_INITIAL:
    return "Initial";
  case NGTCP2_PKT_0RTT:
    return "0RTT";
  case NGTCP2_PKT_HANDSHAKE:
    return "Handshake";
  case NGTCP2_PKT_RETRY:
    return "Retry";
  case NGTCP2_PKT_1RTT:
    return "1RTT";
  case NGTCP2_PKT_VERSION_NEGOTIATION:
    return "VN";
  case NGTCP2_PKT_STATELESS_RESET:
    return "SR";
  default:
    return "(unknown)";
  }
}

static const char *strpkttype_type_flags(uint8_t type, uint8_t flags) {
  return strpkttype(&(ngtcp2_pkt_hd){
    .type = type,
    .flags = flags,
  });
}

static void log_fr_stream(ngtcp2_log *log, const ngtcp2_pkt_hd *hd,
                          const ngtcp2_stream *fr, const char *dir) {
  ngtcp2_log_infof_raw(
    log, NGTCP2_LOG_EVENT_FRM, NGTCP2_LOG_PKT(dir, hd), " STREAM(0x",
    hex(fr->type | fr->flags), ") id=0x", hex(fr->stream_id), " fin=", fr->fin,
    " offset=", fr->offset, " len=", ngtcp2_vec_len(fr->data, fr->datacnt),
    " uni=", (fr->stream_id & 0x2) != 0);
}

static void log_fr_ack(ngtcp2_log *log, const ngtcp2_pkt_hd *hd,
                       const ngtcp2_ack *fr, const char *dir) {
  int64_t largest_ack, min_ack;
  size_t i;

  ngtcp2_log_infof_raw(
    log, NGTCP2_LOG_EVENT_FRM, NGTCP2_LOG_PKT(dir, hd), " ACK(0x",
    hex(fr->type), ") largest_ack=", fr->largest_ack,
    " ack_delay=", fr->ack_delay_unscaled / NGTCP2_MILLISECONDS, "(",
    fr->ack_delay, ") ack_range_count=", fr->rangecnt);

  largest_ack = fr->largest_ack;
  min_ack = fr->largest_ack - (int64_t)fr->first_ack_range;

  ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_FRM, NGTCP2_LOG_PKT(dir, hd),
                       " ACK(0x", hex(fr->type), ") range=[", largest_ack, "..",
                       min_ack, "] len=", fr->first_ack_range);

  for (i = 0; i < fr->rangecnt; ++i) {
    const ngtcp2_ack_range *range = &fr->ranges[i];
    largest_ack = min_ack - (int64_t)range->gap - 2;
    min_ack = largest_ack - (int64_t)range->len;
    ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_FRM, NGTCP2_LOG_PKT(dir, hd),
                         " ACK(0x", hex(fr->type), ") range=[", largest_ack,
                         "..", min_ack, "] gap=", range->gap,
                         " len=", range->len);
  }

  if (fr->type == NGTCP2_FRAME_ACK_ECN) {
    ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_FRM, NGTCP2_LOG_PKT(dir, hd),
                         " ACK(0x", hex(fr->type), ") ect0=", fr->ecn.ect0,
                         " ect1=", fr->ecn.ect1, " ce=", fr->ecn.ce);
  }
}

static void log_fr_padding(ngtcp2_log *log, const ngtcp2_pkt_hd *hd,
                           const ngtcp2_padding *fr, const char *dir) {
  ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_FRM, NGTCP2_LOG_PKT(dir, hd),
                       " PADDING(0x", hex(fr->type), ") len=", fr->len);
}

static void log_fr_reset_stream(ngtcp2_log *log, const ngtcp2_pkt_hd *hd,
                                const ngtcp2_reset_stream *fr,
                                const char *dir) {
  ngtcp2_log_infof_raw(
    log, NGTCP2_LOG_EVENT_FRM, NGTCP2_LOG_PKT(dir, hd), " RESET_STREAM(0x",
    hex(fr->type), ") id=0x", hex(fr->stream_id),
    " app_error_code=", strapperrorcode(fr->app_error_code), "(0x",
    hex(fr->app_error_code), ") final_size=", fr->final_size);
}

static void log_fr_connection_close(ngtcp2_log *log, const ngtcp2_pkt_hd *hd,
                                    const ngtcp2_connection_close *fr,
                                    const char *dir) {
  size_t reasonlen = ngtcp2_min(64, fr->reasonlen);

  ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_FRM, NGTCP2_LOG_PKT(dir, hd),
                       " CONNECTION_CLOSE(0x", hex(fr->type), ") error_code=",
                       fr->type == NGTCP2_FRAME_CONNECTION_CLOSE
                         ? strerrorcode(fr->error_code)
                         : strapperrorcode(fr->error_code),
                       "(0x", hex(fr->error_code), ") frame_type=0x",
                       hex(fr->frame_type), " reason_len=", fr->reasonlen,
                       " reason=[", ascii(fr->reason, reasonlen), "]");
}

static void log_fr_max_data(ngtcp2_log *log, const ngtcp2_pkt_hd *hd,
                            const ngtcp2_max_data *fr, const char *dir) {
  ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_FRM, NGTCP2_LOG_PKT(dir, hd),
                       " MAX_DATA(0x", hex(fr->type),
                       ") max_data=", fr->max_data);
}

static void log_fr_max_stream_data(ngtcp2_log *log, const ngtcp2_pkt_hd *hd,
                                   const ngtcp2_max_stream_data *fr,
                                   const char *dir) {
  ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_FRM, NGTCP2_LOG_PKT(dir, hd),
                       " MAX_STREAM_DATA(0x", hex(fr->type), ") id=0x",
                       hex(fr->stream_id),
                       " max_stream_data=", fr->max_stream_data);
}

static void log_fr_max_streams(ngtcp2_log *log, const ngtcp2_pkt_hd *hd,
                               const ngtcp2_max_streams *fr, const char *dir) {
  ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_FRM, NGTCP2_LOG_PKT(dir, hd),
                       " MAX_STREAMS(0x", hex(fr->type),
                       ") max_streams=", fr->max_streams);
}

static void log_fr_ping(ngtcp2_log *log, const ngtcp2_pkt_hd *hd,
                        const ngtcp2_ping *fr, const char *dir) {
  ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_FRM, NGTCP2_LOG_PKT(dir, hd),
                       " PING(0x", hex(fr->type), ")");
}

static void log_fr_data_blocked(ngtcp2_log *log, const ngtcp2_pkt_hd *hd,
                                const ngtcp2_data_blocked *fr,
                                const char *dir) {
  ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_FRM, NGTCP2_LOG_PKT(dir, hd),
                       " DATA_BLOCKED(0x", hex(fr->type),
                       ") offset=", fr->offset);
}

static void log_fr_stream_data_blocked(ngtcp2_log *log, const ngtcp2_pkt_hd *hd,
                                       const ngtcp2_stream_data_blocked *fr,
                                       const char *dir) {
  ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_FRM, NGTCP2_LOG_PKT(dir, hd),
                       " STREAM_DATA_BLOCKED(0x", hex(fr->type), ") id=0x",
                       hex(fr->stream_id), " offset=", fr->offset);
}

static void log_fr_streams_blocked(ngtcp2_log *log, const ngtcp2_pkt_hd *hd,
                                   const ngtcp2_streams_blocked *fr,
                                   const char *dir) {
  ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_FRM, NGTCP2_LOG_PKT(dir, hd),
                       " STREAMS_BLOCKED(0x", hex(fr->type),
                       ") max_streams=", fr->max_streams);
}

static void log_fr_new_connection_id(ngtcp2_log *log, const ngtcp2_pkt_hd *hd,
                                     const ngtcp2_new_connection_id *fr,
                                     const char *dir) {
  ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_FRM, NGTCP2_LOG_PKT(dir, hd),
                       " NEW_CONNECTION_ID(0x", hex(fr->type),
                       ") seq=", fr->seq, " cid=0x", &fr->cid,
                       " retire_prior_to=", fr->retire_prior_to,
                       " stateless_reset_token=0x", &fr->token);
}

static void log_fr_stop_sending(ngtcp2_log *log, const ngtcp2_pkt_hd *hd,
                                const ngtcp2_stop_sending *fr,
                                const char *dir) {
  ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_FRM, NGTCP2_LOG_PKT(dir, hd),
                       " STOP_SENDING(0x", hex(fr->type), ") id=0x",
                       hex(fr->stream_id),
                       " app_error_code=", strapperrorcode(fr->app_error_code),
                       "(0x", hex(fr->app_error_code), ")");
}

static void log_fr_path_challenge(ngtcp2_log *log, const ngtcp2_pkt_hd *hd,
                                  const ngtcp2_path_challenge *fr,
                                  const char *dir) {
  ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_FRM, NGTCP2_LOG_PKT(dir, hd),
                       " PATH_CHALLENGE(0x", hex(fr->type), ") data=0x",
                       &fr->data);
}

static void log_fr_path_response(ngtcp2_log *log, const ngtcp2_pkt_hd *hd,
                                 const ngtcp2_path_response *fr,
                                 const char *dir) {
  ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_FRM, NGTCP2_LOG_PKT(dir, hd),
                       " PATH_RESPONSE(0x", hex(fr->type), ") data=0x",
                       &fr->data);
}

static void log_fr_crypto(ngtcp2_log *log, const ngtcp2_pkt_hd *hd,
                          const ngtcp2_stream *fr, const char *dir) {
  ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_FRM, NGTCP2_LOG_PKT(dir, hd),
                       " CRYPTO(0x", hex(fr->type), ") offset=", fr->offset,
                       " len=", ngtcp2_vec_len(fr->data, fr->datacnt));
}

#define NGTCP2_LOG_MAX_TOKENLEN 64

static void log_fr_new_token(ngtcp2_log *log, const ngtcp2_pkt_hd *hd,
                             const ngtcp2_new_token *fr, const char *dir) {
  /* Show at most first NGTCP2_LOG_MAX_TOKENLEN bytes of token.  If
     token is longer than that, log first those bytes and then append
     "*" */
  size_t tokenlen = ngtcp2_min(fr->tokenlen, NGTCP2_LOG_MAX_TOKENLEN);

  ngtcp2_log_infof_raw(
    log, NGTCP2_LOG_EVENT_FRM, NGTCP2_LOG_PKT(dir, hd), " NEW_TOKEN(0x",
    hex(fr->type), ") token=0x", bhex(fr->token, tokenlen),
    fr->tokenlen > NGTCP2_LOG_MAX_TOKENLEN ? "*" : "", " len=", fr->tokenlen);
}

static void log_fr_retire_connection_id(ngtcp2_log *log,
                                        const ngtcp2_pkt_hd *hd,
                                        const ngtcp2_retire_connection_id *fr,
                                        const char *dir) {
  ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_FRM, NGTCP2_LOG_PKT(dir, hd),
                       " RETIRE_CONNECTION_ID(0x", hex(fr->type),
                       ") seq=", fr->seq);
}

static void log_fr_handshake_done(ngtcp2_log *log, const ngtcp2_pkt_hd *hd,
                                  const ngtcp2_handshake_done *fr,
                                  const char *dir) {
  ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_FRM, NGTCP2_LOG_PKT(dir, hd),
                       " HANDSHAKE_DONE(0x", hex(fr->type), ")");
}

static void log_fr_datagram(ngtcp2_log *log, const ngtcp2_pkt_hd *hd,
                            const ngtcp2_datagram *fr, const char *dir) {
  ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_FRM, NGTCP2_LOG_PKT(dir, hd),
                       " DATAGRAM(0x", hex(fr->type),
                       ") len=", ngtcp2_vec_len(fr->data, fr->datacnt));
}

static void log_fr(ngtcp2_log *log, const ngtcp2_pkt_hd *hd,
                   const ngtcp2_frame *fr, const char *dir) {
  switch (fr->hd.type) {
  case NGTCP2_FRAME_STREAM:
    log_fr_stream(log, hd, &fr->stream, dir);
    break;
  case NGTCP2_FRAME_ACK:
  case NGTCP2_FRAME_ACK_ECN:
    log_fr_ack(log, hd, &fr->ack, dir);
    break;
  case NGTCP2_FRAME_PADDING:
    log_fr_padding(log, hd, &fr->padding, dir);
    break;
  case NGTCP2_FRAME_RESET_STREAM:
    log_fr_reset_stream(log, hd, &fr->reset_stream, dir);
    break;
  case NGTCP2_FRAME_CONNECTION_CLOSE:
  case NGTCP2_FRAME_CONNECTION_CLOSE_APP:
    log_fr_connection_close(log, hd, &fr->connection_close, dir);
    break;
  case NGTCP2_FRAME_MAX_DATA:
    log_fr_max_data(log, hd, &fr->max_data, dir);
    break;
  case NGTCP2_FRAME_MAX_STREAM_DATA:
    log_fr_max_stream_data(log, hd, &fr->max_stream_data, dir);
    break;
  case NGTCP2_FRAME_MAX_STREAMS_BIDI:
  case NGTCP2_FRAME_MAX_STREAMS_UNI:
    log_fr_max_streams(log, hd, &fr->max_streams, dir);
    break;
  case NGTCP2_FRAME_PING:
    log_fr_ping(log, hd, &fr->ping, dir);
    break;
  case NGTCP2_FRAME_DATA_BLOCKED:
    log_fr_data_blocked(log, hd, &fr->data_blocked, dir);
    break;
  case NGTCP2_FRAME_STREAM_DATA_BLOCKED:
    log_fr_stream_data_blocked(log, hd, &fr->stream_data_blocked, dir);
    break;
  case NGTCP2_FRAME_STREAMS_BLOCKED_BIDI:
  case NGTCP2_FRAME_STREAMS_BLOCKED_UNI:
    log_fr_streams_blocked(log, hd, &fr->streams_blocked, dir);
    break;
  case NGTCP2_FRAME_NEW_CONNECTION_ID:
    log_fr_new_connection_id(log, hd, &fr->new_connection_id, dir);
    break;
  case NGTCP2_FRAME_STOP_SENDING:
    log_fr_stop_sending(log, hd, &fr->stop_sending, dir);
    break;
  case NGTCP2_FRAME_PATH_CHALLENGE:
    log_fr_path_challenge(log, hd, &fr->path_challenge, dir);
    break;
  case NGTCP2_FRAME_PATH_RESPONSE:
    log_fr_path_response(log, hd, &fr->path_response, dir);
    break;
  case NGTCP2_FRAME_CRYPTO:
    log_fr_crypto(log, hd, &fr->stream, dir);
    break;
  case NGTCP2_FRAME_NEW_TOKEN:
    log_fr_new_token(log, hd, &fr->new_token, dir);
    break;
  case NGTCP2_FRAME_RETIRE_CONNECTION_ID:
    log_fr_retire_connection_id(log, hd, &fr->retire_connection_id, dir);
    break;
  case NGTCP2_FRAME_HANDSHAKE_DONE:
    log_fr_handshake_done(log, hd, &fr->handshake_done, dir);
    break;
  case NGTCP2_FRAME_DATAGRAM:
  case NGTCP2_FRAME_DATAGRAM_LEN:
    log_fr_datagram(log, hd, &fr->datagram, dir);
    break;
  default:
    ngtcp2_unreachable();
  }
}

void ngtcp2_log_rx_fr(ngtcp2_log *log, const ngtcp2_pkt_hd *hd,
                      const ngtcp2_frame *fr) {
  if ((!log->log_write && !log->log_printf) ||
      !(log->events & NGTCP2_LOG_EVENT_FRM)) {
    return;
  }

  log_fr(log, hd, fr, "rx");
}

void ngtcp2_log_tx_fr(ngtcp2_log *log, const ngtcp2_pkt_hd *hd,
                      const ngtcp2_frame *fr) {
  if ((!log->log_write && !log->log_printf) ||
      !(log->events & NGTCP2_LOG_EVENT_FRM)) {
    return;
  }

  log_fr(log, hd, fr, "tx");
}

void ngtcp2_log_rx_vn(ngtcp2_log *log, const ngtcp2_pkt_hd *hd,
                      const uint32_t *sv, size_t nsv) {
  size_t i;

  if ((!log->log_write && !log->log_printf) ||
      !(log->events & NGTCP2_LOG_EVENT_PKT)) {
    return;
  }

  for (i = 0; i < nsv; ++i) {
    ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_PKT, NGTCP2_LOG_PKT("rx", hd),
                         " v=0x", hexw(sv[i], 8));
  }
}

void ngtcp2_log_rx_sr(ngtcp2_log *log, const ngtcp2_pkt_stateless_reset2 *sr) {
  ngtcp2_pkt_hd hd;

  if ((!log->log_write && !log->log_printf) ||
      !(log->events & NGTCP2_LOG_EVENT_PKT)) {
    return;
  }

  hd = (ngtcp2_pkt_hd){
    .type = NGTCP2_PKT_STATELESS_RESET,
  };

  ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_PKT, NGTCP2_LOG_PKT("rx", &hd),
                       " token=0x", &sr->token, " randlen=", sr->randlen);
}

void ngtcp2_log_remote_tp(ngtcp2_log *log,
                          const ngtcp2_transport_params *params) {
  size_t i;
  const ngtcp2_sockaddr_in *sa_in;
  const ngtcp2_sockaddr_in6 *sa_in6;
  const uint8_t *p;
  uint32_t version;

  if ((!log->log_write && !log->log_printf) ||
      !(log->events & NGTCP2_LOG_EVENT_CRY)) {
    return;
  }

  if (params->stateless_reset_token_present) {
    ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_CRY,
                         NGTCP2_LOG_TP " stateless_reset_token=0x",
                         lbhex(params->stateless_reset_token));
  }

  if (params->preferred_addr_present) {
    if (params->preferred_addr.ipv4_present) {
      sa_in = &params->preferred_addr.ipv4;

      ngtcp2_log_infof_raw(
        log, NGTCP2_LOG_EVENT_CRY,
        NGTCP2_LOG_TP " preferred_address.ipv4_addr=", &sa_in->sin_addr);
      ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_CRY,
                           NGTCP2_LOG_TP " preferred_address.ipv4_port=",
                           ngtcp2_ntohs(sa_in->sin_port));
    }

    if (params->preferred_addr.ipv6_present) {
      sa_in6 = &params->preferred_addr.ipv6;

      ngtcp2_log_infof_raw(
        log, NGTCP2_LOG_EVENT_CRY,
        NGTCP2_LOG_TP " preferred_address.ipv6_addr=", &sa_in6->sin6_addr);
      ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_CRY,
                           NGTCP2_LOG_TP " preferred_address.ipv6_port=",
                           ngtcp2_ntohs(sa_in6->sin6_port));
    }

    ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_CRY,
                         NGTCP2_LOG_TP " preferred_address.cid=0x",
                         &params->preferred_addr.cid);
    ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_CRY,
                         NGTCP2_LOG_TP
                         " preferred_address.stateless_reset_token=0x",
                         lbhex(params->preferred_addr.stateless_reset_token));
  }

  if (params->original_dcid_present) {
    ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_CRY,
                         NGTCP2_LOG_TP " original_destination_connection_id=0x",
                         &params->original_dcid);
  }

  if (params->retry_scid_present) {
    ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_CRY,
                         NGTCP2_LOG_TP " retry_source_connection_id=0x",
                         &params->retry_scid);
  }

  if (params->initial_scid_present) {
    ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_CRY,
                         NGTCP2_LOG_TP " initial_source_connection_id=0x",
                         &params->initial_scid);
  }

  ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_CRY,
                       NGTCP2_LOG_TP " initial_max_stream_data_bidi_local=",
                       params->initial_max_stream_data_bidi_local);
  ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_CRY,
                       NGTCP2_LOG_TP " initial_max_stream_data_bidi_remote=",
                       params->initial_max_stream_data_bidi_remote);
  ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_CRY,
                       NGTCP2_LOG_TP " initial_max_stream_data_uni=",
                       params->initial_max_stream_data_uni);
  ngtcp2_log_infof_raw(
    log, NGTCP2_LOG_EVENT_CRY,
    NGTCP2_LOG_TP " initial_max_data=", params->initial_max_data);
  ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_CRY,
                       NGTCP2_LOG_TP " initial_max_streams_bidi=",
                       params->initial_max_streams_bidi);
  ngtcp2_log_infof_raw(
    log, NGTCP2_LOG_EVENT_CRY,
    NGTCP2_LOG_TP " initial_max_streams_uni=", params->initial_max_streams_uni);
  ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_CRY,
                       NGTCP2_LOG_TP " max_idle_timeout=",
                       params->max_idle_timeout / NGTCP2_MILLISECONDS);
  ngtcp2_log_infof_raw(
    log, NGTCP2_LOG_EVENT_CRY,
    NGTCP2_LOG_TP " max_udp_payload_size=", params->max_udp_payload_size);
  ngtcp2_log_infof_raw(
    log, NGTCP2_LOG_EVENT_CRY,
    NGTCP2_LOG_TP " ack_delay_exponent=", params->ack_delay_exponent);
  ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_CRY,
                       NGTCP2_LOG_TP " max_ack_delay=",
                       params->max_ack_delay / NGTCP2_MILLISECONDS);
  ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_CRY,
                       NGTCP2_LOG_TP " active_connection_id_limit=",
                       params->active_connection_id_limit);
  ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_CRY,
                       NGTCP2_LOG_TP " disable_active_migration=",
                       params->disable_active_migration);
  ngtcp2_log_infof_raw(
    log, NGTCP2_LOG_EVENT_CRY,
    NGTCP2_LOG_TP " max_datagram_frame_size=", params->max_datagram_frame_size);
  ngtcp2_log_infof_raw(
    log, NGTCP2_LOG_EVENT_CRY,
    NGTCP2_LOG_TP " grease_quic_bit=", params->grease_quic_bit);

  if (params->version_info_present) {
    ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_CRY,
                         NGTCP2_LOG_TP " version_information.chosen_version=0x",
                         hexw(params->version_info.chosen_version, 8));

    assert(!(params->version_info.available_versionslen & 0x3));

    for (i = 0, p = params->version_info.available_versions;
         i < params->version_info.available_versionslen;
         i += sizeof(uint32_t)) {
      p = ngtcp2_get_uint32be(&version, p);

      ngtcp2_log_infof_raw(log, NGTCP2_LOG_EVENT_CRY,
                           NGTCP2_LOG_TP
                           " version_information.available_versions[",
                           i >> 2, "]=0x", hexw(version, 8));
    }
  }
}

void ngtcp2_log_pkt_lost(ngtcp2_log *log, int64_t pkt_num, uint8_t type,
                         uint8_t flags, ngtcp2_tstamp sent_ts) {
  if ((!log->log_write && !log->log_printf) ||
      !(log->events & NGTCP2_LOG_EVENT_LDC)) {
    return;
  }

  ngtcp2_log_infof(log, NGTCP2_LOG_EVENT_LDC, "pkn=", pkt_num,
                   " lost type=", strpkttype_type_flags(type, flags),
                   " sent_ts=", sent_ts);
}

static void log_pkt_hd(ngtcp2_log *log, const ngtcp2_pkt_hd *hd,
                       const char *dir) {
  if ((!log->log_write && !log->log_printf) ||
      !(log->events & NGTCP2_LOG_EVENT_PKT)) {
    return;
  }

  if (hd->type == NGTCP2_PKT_1RTT) {
    ngtcp2_log_infof(log, NGTCP2_LOG_EVENT_PKT, dir, " pkn=", hd->pkt_num,
                     " dcid=0x", &hd->dcid, " type=", strpkttype(hd),
                     " k=", (hd->flags & NGTCP2_PKT_FLAG_KEY_PHASE) != 0);
  } else {
    ngtcp2_log_infof(log, NGTCP2_LOG_EVENT_PKT, dir, " pkn=", hd->pkt_num,
                     " dcid=0x", &hd->dcid, " scid=0x", &hd->scid,
                     " version=0x", hexw(hd->version, 8),
                     " type=", strpkttype(hd), " len=", hd->len);
  }
}

void ngtcp2_log_rx_pkt_hd(ngtcp2_log *log, const ngtcp2_pkt_hd *hd) {
  log_pkt_hd(log, hd, "rx");
}

void ngtcp2_log_tx_pkt_hd(ngtcp2_log *log, const ngtcp2_pkt_hd *hd) {
  log_pkt_hd(log, hd, "tx");
}

uint64_t ngtcp2_log_timestamp(const ngtcp2_log *log) {
  return (log->last_ts - log->ts) / NGTCP2_MILLISECONDS;
}