diff --git a/deps/ngtcp2/ngtcp2/crypto/boringssl/boringssl.c b/deps/ngtcp2/ngtcp2/crypto/boringssl/boringssl.c
index 283063f738e2af..0409a4e50cae7a 100644
--- a/deps/ngtcp2/ngtcp2/crypto/boringssl/boringssl.c
+++ b/deps/ngtcp2/ngtcp2/crypto/boringssl/boringssl.c
@@ -39,6 +39,7 @@
 #include <openssl/chacha.h>
 #include <openssl/rand.h>
 
+#include "ngtcp2_macro.h"
 #include "shared.h"
 
 typedef enum ngtcp2_crypto_boringssl_cipher_type {
@@ -419,7 +420,7 @@ int ngtcp2_crypto_hp_mask(uint8_t *dest, const ngtcp2_crypto_cipher *hp,
 #else  /* !defined(WORDS_BIGENDIAN) */
     memcpy(&counter, sample, sizeof(counter));
 #endif /* !defined(WORDS_BIGENDIAN) */
-    CRYPTO_chacha_20(dest, PLAINTEXT, sizeof(PLAINTEXT) - 1, ctx->key,
+    CRYPTO_chacha_20(dest, PLAINTEXT, ngtcp2_strlen_lit(PLAINTEXT), ctx->key,
                      sample + sizeof(counter), counter);
     return 0;
   default:
diff --git a/deps/ngtcp2/ngtcp2/crypto/ossl/ossl.c b/deps/ngtcp2/ngtcp2/crypto/ossl/ossl.c
index 4b4733a2c36c20..81cadc6424b3e7 100644
--- a/deps/ngtcp2/ngtcp2/crypto/ossl/ossl.c
+++ b/deps/ngtcp2/ngtcp2/crypto/ossl/ossl.c
@@ -845,8 +845,9 @@ int ngtcp2_crypto_hp_mask(uint8_t *dest, const ngtcp2_crypto_cipher *hp,
   (void)hp;
 
   if (!EVP_EncryptInit_ex(actx, NULL, NULL, NULL, sample) ||
-      !EVP_EncryptUpdate(actx, dest, &len, PLAINTEXT, sizeof(PLAINTEXT) - 1) ||
-      !EVP_EncryptFinal_ex(actx, dest + sizeof(PLAINTEXT) - 1, &len)) {
+      !EVP_EncryptUpdate(actx, dest, &len, PLAINTEXT,
+                         ngtcp2_strlen_lit(PLAINTEXT)) ||
+      !EVP_EncryptFinal_ex(actx, dest + ngtcp2_strlen_lit(PLAINTEXT), &len)) {
     return -1;
   }
 
diff --git a/deps/ngtcp2/ngtcp2/crypto/picotls/picotls.c b/deps/ngtcp2/ngtcp2/crypto/picotls/picotls.c
index 98ebf9e876c053..d9a388e3699ce1 100644
--- a/deps/ngtcp2/ngtcp2/crypto/picotls/picotls.c
+++ b/deps/ngtcp2/ngtcp2/crypto/picotls/picotls.c
@@ -35,6 +35,7 @@
 #include <picotls.h>
 #include <picotls/openssl.h>
 
+#include "ngtcp2_macro.h"
 #include "shared.h"
 
 ngtcp2_crypto_aead *ngtcp2_crypto_aead_aes_128_gcm(ngtcp2_crypto_aead *aead) {
@@ -357,7 +358,7 @@ int ngtcp2_crypto_hp_mask(uint8_t *dest, const ngtcp2_crypto_cipher *hp,
   (void)hp;
 
   ptls_cipher_init(actx, sample);
-  ptls_cipher_encrypt(actx, dest, PLAINTEXT, sizeof(PLAINTEXT) - 1);
+  ptls_cipher_encrypt(actx, dest, PLAINTEXT, ngtcp2_strlen_lit(PLAINTEXT));
 
   return 0;
 }
diff --git a/deps/ngtcp2/ngtcp2/crypto/quictls/quictls.c b/deps/ngtcp2/ngtcp2/crypto/quictls/quictls.c
index 592e5a86535356..742321ec857690 100644
--- a/deps/ngtcp2/ngtcp2/crypto/quictls/quictls.c
+++ b/deps/ngtcp2/ngtcp2/crypto/quictls/quictls.c
@@ -40,6 +40,7 @@
 #  include <openssl/core_names.h>
 #endif /* OPENSSL_VERSION_NUMBER >= 0x30000000L */
 
+#include "ngtcp2_macro.h"
 #include "shared.h"
 
 #if OPENSSL_VERSION_NUMBER >= 0x30000000L
@@ -785,8 +786,9 @@ int ngtcp2_crypto_hp_mask(uint8_t *dest, const ngtcp2_crypto_cipher *hp,
   (void)hp;
 
   if (!EVP_EncryptInit_ex(actx, NULL, NULL, NULL, sample) ||
-      !EVP_EncryptUpdate(actx, dest, &len, PLAINTEXT, sizeof(PLAINTEXT) - 1) ||
-      !EVP_EncryptFinal_ex(actx, dest + sizeof(PLAINTEXT) - 1, &len)) {
+      !EVP_EncryptUpdate(actx, dest, &len, PLAINTEXT,
+                         ngtcp2_strlen_lit(PLAINTEXT)) ||
+      !EVP_EncryptFinal_ex(actx, dest + ngtcp2_strlen_lit(PLAINTEXT), &len)) {
     return -1;
   }
 
diff --git a/deps/ngtcp2/ngtcp2/crypto/shared.c b/deps/ngtcp2/ngtcp2/crypto/shared.c
index 062efb45e950cc..1d8d1d68f78fd7 100644
--- a/deps/ngtcp2/ngtcp2/crypto/shared.c
+++ b/deps/ngtcp2/ngtcp2/crypto/shared.c
@@ -53,9 +53,9 @@ int ngtcp2_crypto_hkdf_expand_label(uint8_t *dest, size_t destlen,
 
   *p++ = (uint8_t)(destlen / 256);
   *p++ = (uint8_t)(destlen % 256);
-  *p++ = (uint8_t)(sizeof(LABEL) - 1 + labellen);
-  memcpy(p, LABEL, sizeof(LABEL) - 1);
-  p += sizeof(LABEL) - 1;
+  *p++ = (uint8_t)(ngtcp2_strlen_lit(LABEL) + labellen);
+  memcpy(p, LABEL, ngtcp2_strlen_lit(LABEL));
+  p += ngtcp2_strlen_lit(LABEL);
   memcpy(p, label, labellen);
   p += labellen;
   *p++ = 0;
@@ -88,11 +88,11 @@ int ngtcp2_crypto_derive_initial_secrets(uint8_t *rx_secret, uint8_t *tx_secret,
   case NGTCP2_PROTO_VER_V1:
   default:
     salt = (const uint8_t *)NGTCP2_INITIAL_SALT_V1;
-    saltlen = sizeof(NGTCP2_INITIAL_SALT_V1) - 1;
+    saltlen = ngtcp2_strlen_lit(NGTCP2_INITIAL_SALT_V1);
     break;
   case NGTCP2_PROTO_VER_V2:
     salt = (const uint8_t *)NGTCP2_INITIAL_SALT_V2;
-    saltlen = sizeof(NGTCP2_INITIAL_SALT_V2) - 1;
+    saltlen = ngtcp2_strlen_lit(NGTCP2_INITIAL_SALT_V2);
     break;
   }
 
@@ -111,10 +111,12 @@ int ngtcp2_crypto_derive_initial_secrets(uint8_t *rx_secret, uint8_t *tx_secret,
 
   if (ngtcp2_crypto_hkdf_expand_label(
         client_secret, NGTCP2_CRYPTO_INITIAL_SECRETLEN, &ctx.md, initial_secret,
-        NGTCP2_CRYPTO_INITIAL_SECRETLEN, CLABEL, sizeof(CLABEL) - 1) != 0 ||
+        NGTCP2_CRYPTO_INITIAL_SECRETLEN, CLABEL,
+        ngtcp2_strlen_lit(CLABEL)) != 0 ||
       ngtcp2_crypto_hkdf_expand_label(
         server_secret, NGTCP2_CRYPTO_INITIAL_SECRETLEN, &ctx.md, initial_secret,
-        NGTCP2_CRYPTO_INITIAL_SECRETLEN, SLABEL, sizeof(SLABEL) - 1) != 0) {
+        NGTCP2_CRYPTO_INITIAL_SECRETLEN, SLABEL,
+        ngtcp2_strlen_lit(SLABEL)) != 0) {
     return -1;
   }
 
@@ -148,19 +150,19 @@ int ngtcp2_crypto_derive_packet_protection_key(
   switch (version) {
   case NGTCP2_PROTO_VER_V2:
     key_label = KEY_LABEL_V2;
-    key_labellen = sizeof(KEY_LABEL_V2) - 1;
+    key_labellen = ngtcp2_strlen_lit(KEY_LABEL_V2);
     iv_label = IV_LABEL_V2;
-    iv_labellen = sizeof(IV_LABEL_V2) - 1;
+    iv_labellen = ngtcp2_strlen_lit(IV_LABEL_V2);
     hp_key_label = HP_KEY_LABEL_V2;
-    hp_key_labellen = sizeof(HP_KEY_LABEL_V2) - 1;
+    hp_key_labellen = ngtcp2_strlen_lit(HP_KEY_LABEL_V2);
     break;
   default:
     key_label = KEY_LABEL_V1;
-    key_labellen = sizeof(KEY_LABEL_V1) - 1;
+    key_labellen = ngtcp2_strlen_lit(KEY_LABEL_V1);
     iv_label = IV_LABEL_V1;
-    iv_labellen = sizeof(IV_LABEL_V1) - 1;
+    iv_labellen = ngtcp2_strlen_lit(IV_LABEL_V1);
     hp_key_label = HP_KEY_LABEL_V1;
-    hp_key_labellen = sizeof(HP_KEY_LABEL_V1) - 1;
+    hp_key_labellen = ngtcp2_strlen_lit(HP_KEY_LABEL_V1);
   }
 
   if (ngtcp2_crypto_hkdf_expand_label(key, keylen, md, secret, secretlen,
@@ -194,11 +196,11 @@ int ngtcp2_crypto_update_traffic_secret(uint8_t *dest, uint32_t version,
   switch (version) {
   case NGTCP2_PROTO_VER_V2:
     label = LABEL_V2;
-    labellen = sizeof(LABEL_V2) - 1;
+    labellen = ngtcp2_strlen_lit(LABEL_V2);
     break;
   default:
     label = LABEL;
-    labellen = sizeof(LABEL) - 1;
+    labellen = ngtcp2_strlen_lit(LABEL);
   }
 
   if (ngtcp2_crypto_hkdf_expand_label(dest, secretlen, md, secret, secretlen,
@@ -592,11 +594,11 @@ int ngtcp2_crypto_derive_and_install_initial_key(
     case NGTCP2_PROTO_VER_V1:
     default:
       retry_key = (const uint8_t *)NGTCP2_RETRY_KEY_V1;
-      retry_noncelen = sizeof(NGTCP2_RETRY_NONCE_V1) - 1;
+      retry_noncelen = ngtcp2_strlen_lit(NGTCP2_RETRY_NONCE_V1);
       break;
     case NGTCP2_PROTO_VER_V2:
       retry_key = (const uint8_t *)NGTCP2_RETRY_KEY_V2;
-      retry_noncelen = sizeof(NGTCP2_RETRY_NONCE_V2) - 1;
+      retry_noncelen = ngtcp2_strlen_lit(NGTCP2_RETRY_NONCE_V2);
       break;
     }
 
@@ -845,7 +847,7 @@ int ngtcp2_crypto_generate_stateless_reset_token(uint8_t *token,
   if (ngtcp2_crypto_hkdf(token, NGTCP2_STATELESS_RESET_TOKENLEN,
                          ngtcp2_crypto_md_sha256(&md), secret, secretlen,
                          cid->data, cid->datalen, info,
-                         sizeof(info) - 1) != 0) {
+                         ngtcp2_strlen_lit(info)) != 0) {
     return -1;
   }
 
@@ -865,8 +867,8 @@ static int crypto_derive_token_key(uint8_t *key, size_t keylen, uint8_t *iv,
   uint8_t *p;
 
   assert(ngtcp2_crypto_md_hashlen(md) == sizeof(intsecret));
-  assert(info_prefixlen + sizeof(key_info_suffix) - 1 <= sizeof(info));
-  assert(info_prefixlen + sizeof(iv_info_suffix) - 1 <= sizeof(info));
+  assert(info_prefixlen + ngtcp2_strlen_lit(key_info_suffix) <= sizeof(info));
+  assert(info_prefixlen + ngtcp2_strlen_lit(iv_info_suffix) <= sizeof(info));
 
   if (ngtcp2_crypto_hkdf_extract(intsecret, md, secret, secretlen, salt,
                                  saltlen) != 0) {
@@ -876,8 +878,8 @@ static int crypto_derive_token_key(uint8_t *key, size_t keylen, uint8_t *iv,
   memcpy(info, info_prefix, info_prefixlen);
   p = info + info_prefixlen;
 
-  memcpy(p, key_info_suffix, sizeof(key_info_suffix) - 1);
-  p += sizeof(key_info_suffix) - 1;
+  memcpy(p, key_info_suffix, ngtcp2_strlen_lit(key_info_suffix));
+  p += ngtcp2_strlen_lit(key_info_suffix);
 
   if (ngtcp2_crypto_hkdf_expand(key, keylen, md, intsecret, sizeof(intsecret),
                                 info, (size_t)(p - info)) != 0) {
@@ -886,8 +888,8 @@ static int crypto_derive_token_key(uint8_t *key, size_t keylen, uint8_t *iv,
 
   p = info + info_prefixlen;
 
-  memcpy(p, iv_info_suffix, sizeof(iv_info_suffix) - 1);
-  p += sizeof(iv_info_suffix) - 1;
+  memcpy(p, iv_info_suffix, ngtcp2_strlen_lit(iv_info_suffix));
+  p += ngtcp2_strlen_lit(iv_info_suffix);
 
   if (ngtcp2_crypto_hkdf_expand(iv, ivlen, md, intsecret, sizeof(intsecret),
                                 info, (size_t)(p - info)) != 0) {
@@ -963,10 +965,10 @@ ngtcp2_ssize ngtcp2_crypto_generate_retry_token(
   assert(sizeof(key) == keylen);
   assert(sizeof(iv) == ivlen);
 
-  if (crypto_derive_token_key(key, keylen, iv, ivlen, &md, secret, secretlen,
-                              rand_data, sizeof(rand_data),
-                              retry_token_info_prefix,
-                              sizeof(retry_token_info_prefix) - 1) != 0) {
+  if (crypto_derive_token_key(
+        key, keylen, iv, ivlen, &md, secret, secretlen, rand_data,
+        sizeof(rand_data), retry_token_info_prefix,
+        ngtcp2_strlen_lit(retry_token_info_prefix)) != 0) {
     return -1;
   }
 
@@ -1040,10 +1042,10 @@ int ngtcp2_crypto_verify_retry_token(
   assert(sizeof(key) == keylen);
   assert(sizeof(iv) == ivlen);
 
-  if (crypto_derive_token_key(key, keylen, iv, ivlen, &md, secret, secretlen,
-                              rand_data, NGTCP2_CRYPTO_TOKEN_RAND_DATALEN,
-                              retry_token_info_prefix,
-                              sizeof(retry_token_info_prefix) - 1) != 0) {
+  if (crypto_derive_token_key(
+        key, keylen, iv, ivlen, &md, secret, secretlen, rand_data,
+        NGTCP2_CRYPTO_TOKEN_RAND_DATALEN, retry_token_info_prefix,
+        ngtcp2_strlen_lit(retry_token_info_prefix)) != 0) {
     return -1;
   }
 
@@ -1143,10 +1145,10 @@ ngtcp2_ssize ngtcp2_crypto_generate_retry_token2(
   assert(sizeof(key) == keylen);
   assert(sizeof(iv) == ivlen);
 
-  if (crypto_derive_token_key(key, keylen, iv, ivlen, &md, secret, secretlen,
-                              rand_data, sizeof(rand_data),
-                              retry_token_info_prefix2,
-                              sizeof(retry_token_info_prefix2) - 1) != 0) {
+  if (crypto_derive_token_key(
+        key, keylen, iv, ivlen, &md, secret, secretlen, rand_data,
+        sizeof(rand_data), retry_token_info_prefix2,
+        ngtcp2_strlen_lit(retry_token_info_prefix2)) != 0) {
     return -1;
   }
 
@@ -1221,10 +1223,10 @@ int ngtcp2_crypto_verify_retry_token2(
   assert(sizeof(key) == keylen);
   assert(sizeof(iv) == ivlen);
 
-  if (crypto_derive_token_key(key, keylen, iv, ivlen, &md, secret, secretlen,
-                              rand_data, NGTCP2_CRYPTO_TOKEN_RAND_DATALEN,
-                              retry_token_info_prefix2,
-                              sizeof(retry_token_info_prefix2) - 1) != 0) {
+  if (crypto_derive_token_key(
+        key, keylen, iv, ivlen, &md, secret, secretlen, rand_data,
+        NGTCP2_CRYPTO_TOKEN_RAND_DATALEN, retry_token_info_prefix2,
+        ngtcp2_strlen_lit(retry_token_info_prefix2)) != 0) {
     return NGTCP2_CRYPTO_ERR_INTERNAL;
   }
 
@@ -1366,10 +1368,10 @@ static ngtcp2_ssize crypto_generate_regular_token(
   assert(sizeof(key) == keylen);
   assert(sizeof(iv) == ivlen);
 
-  if (crypto_derive_token_key(key, keylen, iv, ivlen, &md, secret, secretlen,
-                              rand_data, sizeof(rand_data),
-                              regular_token_info_prefix,
-                              sizeof(regular_token_info_prefix) - 1) != 0) {
+  if (crypto_derive_token_key(
+        key, keylen, iv, ivlen, &md, secret, secretlen, rand_data,
+        sizeof(rand_data), regular_token_info_prefix,
+        ngtcp2_strlen_lit(regular_token_info_prefix)) != 0) {
     return -1;
   }
 
@@ -1442,10 +1444,10 @@ static ngtcp2_ssize crypto_verify_regular_token(
   assert(sizeof(key) == keylen);
   assert(sizeof(iv) == ivlen);
 
-  if (crypto_derive_token_key(key, keylen, iv, ivlen, &md, secret, secretlen,
-                              rand_data, NGTCP2_CRYPTO_TOKEN_RAND_DATALEN,
-                              regular_token_info_prefix,
-                              sizeof(regular_token_info_prefix) - 1) != 0) {
+  if (crypto_derive_token_key(
+        key, keylen, iv, ivlen, &md, secret, secretlen, rand_data,
+        NGTCP2_CRYPTO_TOKEN_RAND_DATALEN, regular_token_info_prefix,
+        ngtcp2_strlen_lit(regular_token_info_prefix)) != 0) {
     return NGTCP2_CRYPTO_ERR_INTERNAL;
   }
 
@@ -1601,11 +1603,11 @@ ngtcp2_ssize ngtcp2_crypto_write_retry(uint8_t *dest, size_t destlen,
   case NGTCP2_PROTO_VER_V1:
   default:
     key = (const uint8_t *)NGTCP2_RETRY_KEY_V1;
-    noncelen = sizeof(NGTCP2_RETRY_NONCE_V1) - 1;
+    noncelen = ngtcp2_strlen_lit(NGTCP2_RETRY_NONCE_V1);
     break;
   case NGTCP2_PROTO_VER_V2:
     key = (const uint8_t *)NGTCP2_RETRY_KEY_V2;
-    noncelen = sizeof(NGTCP2_RETRY_NONCE_V2) - 1;
+    noncelen = ngtcp2_strlen_lit(NGTCP2_RETRY_NONCE_V2);
     break;
   }
 
diff --git a/deps/ngtcp2/ngtcp2/crypto/wolfssl/wolfssl.c b/deps/ngtcp2/ngtcp2/crypto/wolfssl/wolfssl.c
index bc9d9d84a862c5..168d32ce109a8d 100644
--- a/deps/ngtcp2/ngtcp2/crypto/wolfssl/wolfssl.c
+++ b/deps/ngtcp2/ngtcp2/crypto/wolfssl/wolfssl.c
@@ -34,6 +34,7 @@
 #include <wolfssl/ssl.h>
 #include <wolfssl/quic.h>
 
+#include "ngtcp2_macro.h"
 #include "shared.h"
 
 #define PRINTF_DEBUG 0
@@ -297,9 +298,10 @@ int ngtcp2_crypto_hp_mask(uint8_t *dest, const ngtcp2_crypto_cipher *hp,
   if (wolfSSL_EVP_EncryptInit_ex(actx, NULL, NULL, NULL, sample) !=
         WOLFSSL_SUCCESS ||
       wolfSSL_EVP_CipherUpdate(actx, dest, &len, PLAINTEXT,
-                               sizeof(PLAINTEXT) - 1) != WOLFSSL_SUCCESS ||
-      wolfSSL_EVP_EncryptFinal_ex(actx, dest + sizeof(PLAINTEXT) - 1, &len) !=
-        WOLFSSL_SUCCESS) {
+                               ngtcp2_strlen_lit(PLAINTEXT)) !=
+        WOLFSSL_SUCCESS ||
+      wolfSSL_EVP_EncryptFinal_ex(actx, dest + ngtcp2_strlen_lit(PLAINTEXT),
+                                  &len) != WOLFSSL_SUCCESS) {
     DEBUG_MSG("WOLFSSL: hp_mask FAILED\n");
     return -1;
   }
diff --git a/deps/ngtcp2/ngtcp2/examples/client.cc b/deps/ngtcp2/ngtcp2/examples/client.cc
index 56b757b2d91ed1..c25242962ca44d 100644
--- a/deps/ngtcp2/ngtcp2/examples/client.cc
+++ b/deps/ngtcp2/ngtcp2/examples/client.cc
@@ -1049,7 +1049,7 @@ ngtcp2_ssize write_pkt(ngtcp2_conn *conn, ngtcp2_path *path,
 ngtcp2_ssize Client::write_pkt(ngtcp2_path *path, ngtcp2_pkt_info *pi,
                                uint8_t *dest, size_t destlen,
                                ngtcp2_tstamp ts) {
-  std::array<nghttp3_vec, 16> vec;
+  std::array<SharedVec, 16> vec;
 
   for (;;) {
     int64_t stream_id = -1;
@@ -1057,8 +1057,9 @@ ngtcp2_ssize Client::write_pkt(ngtcp2_path *path, ngtcp2_pkt_info *pi,
     nghttp3_ssize sveccnt = 0;
 
     if (httpconn_ && ngtcp2_conn_get_max_data_left(conn_)) {
-      sveccnt = nghttp3_conn_writev_stream(httpconn_, &stream_id, &fin,
-                                           vec.data(), vec.size());
+      sveccnt = nghttp3_conn_writev_stream(
+        httpconn_, &stream_id, &fin,
+        reinterpret_cast<nghttp3_vec *>(vec.data()), vec.size());
       if (sveccnt < 0) {
         std::cerr << "nghttp3_conn_writev_stream: "
                   << nghttp3_strerror(static_cast<int>(sveccnt)) << std::endl;
@@ -1071,7 +1072,6 @@ ngtcp2_ssize Client::write_pkt(ngtcp2_path *path, ngtcp2_pkt_info *pi,
     }
 
     ngtcp2_ssize ndatalen;
-    auto v = vec.data();
     auto vcnt = static_cast<size_t>(sveccnt);
 
     uint32_t flags = NGTCP2_WRITE_STREAM_FLAG_MORE;
@@ -1081,7 +1081,7 @@ ngtcp2_ssize Client::write_pkt(ngtcp2_path *path, ngtcp2_pkt_info *pi,
 
     auto nwrite = ngtcp2_conn_writev_stream(
       conn_, path, pi, dest, destlen, &ndatalen, flags, stream_id,
-      reinterpret_cast<const ngtcp2_vec *>(v), vcnt, ts);
+      reinterpret_cast<const ngtcp2_vec *>(vec.data()), vcnt, ts);
     if (nwrite < 0) {
       switch (nwrite) {
       case NGTCP2_ERR_STREAM_DATA_BLOCKED:
diff --git a/deps/ngtcp2/ngtcp2/examples/server.cc b/deps/ngtcp2/ngtcp2/examples/server.cc
index f9463eacd9cc7d..4f081eab920069 100644
--- a/deps/ngtcp2/ngtcp2/examples/server.cc
+++ b/deps/ngtcp2/ngtcp2/examples/server.cc
@@ -1652,7 +1652,7 @@ ngtcp2_ssize write_pkt(ngtcp2_conn *conn, ngtcp2_path *path,
 ngtcp2_ssize Handler::write_pkt(ngtcp2_path *path, ngtcp2_pkt_info *pi,
                                 uint8_t *dest, size_t destlen,
                                 ngtcp2_tstamp ts) {
-  std::array<nghttp3_vec, 16> vec;
+  std::array<SharedVec, 16> vec;
 
   for (;;) {
     int64_t stream_id = -1;
@@ -1660,8 +1660,9 @@ ngtcp2_ssize Handler::write_pkt(ngtcp2_path *path, ngtcp2_pkt_info *pi,
     nghttp3_ssize sveccnt = 0;
 
     if (httpconn_ && ngtcp2_conn_get_max_data_left(conn_)) {
-      sveccnt = nghttp3_conn_writev_stream(httpconn_, &stream_id, &fin,
-                                           vec.data(), vec.size());
+      sveccnt = nghttp3_conn_writev_stream(
+        httpconn_, &stream_id, &fin,
+        reinterpret_cast<nghttp3_vec *>(vec.data()), vec.size());
       if (sveccnt < 0) {
         std::cerr << "nghttp3_conn_writev_stream: "
                   << nghttp3_strerror(static_cast<int>(sveccnt)) << std::endl;
@@ -1674,7 +1675,6 @@ ngtcp2_ssize Handler::write_pkt(ngtcp2_path *path, ngtcp2_pkt_info *pi,
     }
 
     ngtcp2_ssize ndatalen;
-    auto v = vec.data();
     auto vcnt = static_cast<size_t>(sveccnt);
 
     uint32_t flags =
@@ -1685,7 +1685,7 @@ ngtcp2_ssize Handler::write_pkt(ngtcp2_path *path, ngtcp2_pkt_info *pi,
 
     auto nwrite = ngtcp2_conn_writev_stream(
       conn_, path, pi, dest, destlen, &ndatalen, flags, stream_id,
-      reinterpret_cast<const ngtcp2_vec *>(v), vcnt, ts);
+      reinterpret_cast<const ngtcp2_vec *>(vec.data()), vcnt, ts);
     if (nwrite < 0) {
       switch (nwrite) {
       case NGTCP2_ERR_STREAM_DATA_BLOCKED:
diff --git a/deps/ngtcp2/ngtcp2/examples/shared.h b/deps/ngtcp2/ngtcp2/examples/shared.h
index 26e678816e8f98..5455a529a6ee0f 100644
--- a/deps/ngtcp2/ngtcp2/examples/shared.h
+++ b/deps/ngtcp2/ngtcp2/examples/shared.h
@@ -34,6 +34,7 @@
 #include <span>
 
 #include <ngtcp2/ngtcp2.h>
+#include <nghttp3/nghttp3.h>
 
 #include "network.h"
 
@@ -63,6 +64,11 @@ inline constexpr uint32_t TLS_ALERT_ECH_REQUIRED = 121;
 
 inline constexpr size_t MAX_RECV_PKTS = 64;
 
+union SharedVec {
+  ngtcp2_vec v2;
+  nghttp3_vec v3;
+};
+
 // msghdr_get_ecn gets ECN bits from |msg|.  |family| is the address
 // family from which packet is received.
 uint8_t msghdr_get_ecn(msghdr *msg, int family);
diff --git a/deps/ngtcp2/ngtcp2/examples/sim.cc b/deps/ngtcp2/ngtcp2/examples/sim.cc
index d4dc423eebe189..b1e778f165dbbc 100644
--- a/deps/ngtcp2/ngtcp2/examples/sim.cc
+++ b/deps/ngtcp2/ngtcp2/examples/sim.cc
@@ -95,7 +95,7 @@ uint64_t LinkConfig::compute_expected_goodput(Timestamp::duration rtt) const {
     return g;
   }
 
-  constexpr double margin = 0.95;
+  constexpr double margin = 0.9;
 
   return std::min(g,
                   static_cast<uint64_t>(MAX_UDP_PAYLOAD_SIZE * NGTCP2_SECONDS /
@@ -657,6 +657,12 @@ Event Channel::get_next_event() {
   };
 }
 
+void Channel::run_eventcb(Timestamp ts) {
+  if (link_config_.eventcb) {
+    link_config_.eventcb(ts, link_config_);
+  }
+}
+
 Simulator::Simulator(Endpoint client, Endpoint server)
   : client_{std::move(client)}, server_{std::move(server)} {}
 
@@ -727,6 +733,9 @@ int Simulator::run() {
     client_chan.pop_tx_queue();
     server_chan.pop_tx_queue();
 
+    client_chan.run_eventcb(ts);
+    server_chan.run_eventcb(ts);
+
     switch (event.type) {
     case EVENT_TYPE_TIMEOUT: {
       auto ctx = Context{
diff --git a/deps/ngtcp2/ngtcp2/examples/sim.h b/deps/ngtcp2/ngtcp2/examples/sim.h
index d4f31233581110..a70388686ae9da 100644
--- a/deps/ngtcp2/ngtcp2/examples/sim.h
+++ b/deps/ngtcp2/ngtcp2/examples/sim.h
@@ -91,6 +91,10 @@ struct LinkConfig {
   double loss{};
   // seed is a seed value for the random number generator.
   std::mt19937::result_type seed{};
+  // eventcb is an optional callback that is invoked before processing
+  // each event.  In this callback, LinkConfig can be dynamically
+  // adjusted to simulate dynamic network conditions.
+  std::function<void(Timestamp, LinkConfig &)> eventcb;
 };
 
 struct EndpointConfig {
@@ -174,6 +178,7 @@ class Channel {
   Timestamp get_next_timestamp() const;
   Event get_next_event();
   void pop_tx_queue();
+  void run_eventcb(Timestamp ts);
 
 private:
   bool decide_pkt_lost();
diff --git a/deps/ngtcp2/ngtcp2/lib/includes/ngtcp2/ngtcp2.h b/deps/ngtcp2/ngtcp2/lib/includes/ngtcp2/ngtcp2.h
index a89e9d8184d513..a09ceea382bab1 100644
--- a/deps/ngtcp2/ngtcp2/lib/includes/ngtcp2/ngtcp2.h
+++ b/deps/ngtcp2/ngtcp2/lib/includes/ngtcp2/ngtcp2.h
@@ -5919,9 +5919,9 @@ NGTCP2_EXTERN void ngtcp2_path_storage_zero(ngtcp2_path_storage *ps);
  * * :member:`handshake_timeout <ngtcp2_settings.handshake_timeout>` =
  *   ``UINT64_MAX``
  * * :member:`glitch_ratelim_burst
- *   <ngtcp2_settings.glitch_ratelim_burst>` = 4000
+ *   <ngtcp2_settings.glitch_ratelim_burst>` = 10000
  * * :member:`glitch_ratelim_rate
- *   <ngtcp2_settings.glitch_ratelim_rate>` = 132
+ *   <ngtcp2_settings.glitch_ratelim_rate>` = 330
  */
 NGTCP2_EXTERN void ngtcp2_settings_default_versioned(int settings_version,
                                                      ngtcp2_settings *settings);
diff --git a/deps/ngtcp2/ngtcp2/lib/includes/ngtcp2/version.h b/deps/ngtcp2/ngtcp2/lib/includes/ngtcp2/version.h
index 62904c53ab5df1..6a1ca013450d24 100644
--- a/deps/ngtcp2/ngtcp2/lib/includes/ngtcp2/version.h
+++ b/deps/ngtcp2/ngtcp2/lib/includes/ngtcp2/version.h
@@ -36,7 +36,7 @@
  *
  * Version number of the ngtcp2 library release.
  */
-#define NGTCP2_VERSION "1.19.0"
+#define NGTCP2_VERSION "1.20.0"
 
 /**
  * @macro
@@ -46,6 +46,6 @@
  * number, 8 bits for minor and 8 bits for patch. Version 1.2.3
  * becomes 0x010203.
  */
-#define NGTCP2_VERSION_NUM 0x011300
+#define NGTCP2_VERSION_NUM 0x011400
 
 #endif /* !defined(NGTCP2_VERSION_H) */
diff --git a/deps/ngtcp2/ngtcp2/lib/ngtcp2_acktr.h b/deps/ngtcp2/ngtcp2/lib/ngtcp2_acktr.h
index 6505a1759484e9..1a591c5ead84ea 100644
--- a/deps/ngtcp2/ngtcp2/lib/ngtcp2_acktr.h
+++ b/deps/ngtcp2/ngtcp2/lib/ngtcp2_acktr.h
@@ -120,8 +120,6 @@ typedef struct ngtcp2_acktr {
      packet number. */
   ngtcp2_ksl ents;
   ngtcp2_log *log;
-  /* flags is bitwise OR of zero, or more of NGTCP2_ACKTR_FLAG_*. */
-  uint16_t flags;
   /* first_unacked_ts is timestamp when ngtcp2_acktr_entry is added
      first time after the last outgoing ACK frame. */
   ngtcp2_tstamp first_unacked_ts;
@@ -148,6 +146,9 @@ typedef struct ngtcp2_acktr {
       uint64_t ce;
     } ack;
   } ecn;
+
+  /* flags is bitwise OR of zero, or more of NGTCP2_ACKTR_FLAG_*. */
+  uint16_t flags;
 } ngtcp2_acktr;
 
 /*
diff --git a/deps/ngtcp2/ngtcp2/lib/ngtcp2_bbr.h b/deps/ngtcp2/ngtcp2/lib/ngtcp2_bbr.h
index 5a74921c195007..98b23122ff9908 100644
--- a/deps/ngtcp2/ngtcp2/lib/ngtcp2_bbr.h
+++ b/deps/ngtcp2/ngtcp2/lib/ngtcp2_bbr.h
@@ -75,8 +75,8 @@ typedef struct ngtcp2_cc_bbr {
   ngtcp2_tstamp min_rtt_stamp;
   ngtcp2_tstamp probe_rtt_done_stamp;
   int probe_rtt_round_done;
-  uint64_t prior_cwnd;
   int idle_restart;
+  uint64_t prior_cwnd;
   ngtcp2_tstamp extra_acked_interval_start;
   uint64_t extra_acked_delivered;
 
@@ -91,8 +91,8 @@ typedef struct ngtcp2_cc_bbr {
 
   /* Round counting */
   uint64_t next_round_delivered;
-  int round_start;
   uint64_t round_count;
+  int round_start;
 
   /* Full pipe */
   uint64_t full_bw;
@@ -111,7 +111,6 @@ typedef struct ngtcp2_cc_bbr {
   uint64_t undo_inflight_shortterm;
   uint64_t undo_inflight_longterm;
 
-  int loss_round_start;
   uint64_t loss_round_delivered;
   uint64_t rounds_since_bw_probe;
   uint64_t max_bw;
@@ -125,17 +124,18 @@ typedef struct ngtcp2_cc_bbr {
   ngtcp2_tstamp cycle_stamp;
   ngtcp2_bbr_ack_phase ack_phase;
   ngtcp2_duration bw_probe_wait;
-  int bw_probe_samples;
   size_t bw_probe_up_rounds;
   uint64_t bw_probe_up_acks;
   uint64_t inflight_longterm;
-  int probe_rtt_expired;
   ngtcp2_duration probe_rtt_min_delay;
   ngtcp2_tstamp probe_rtt_min_stamp;
-  int in_loss_recovery;
   uint64_t round_count_at_recovery;
   uint64_t max_inflight;
   uint64_t bdp;
+  int loss_round_start;
+  int bw_probe_samples;
+  int probe_rtt_expired;
+  int in_loss_recovery;
 } ngtcp2_cc_bbr;
 
 void ngtcp2_cc_bbr_init(ngtcp2_cc_bbr *bbr, ngtcp2_log *log,
diff --git a/deps/ngtcp2/ngtcp2/lib/ngtcp2_conn.c b/deps/ngtcp2/ngtcp2/lib/ngtcp2_conn.c
index fdf9516c3e9345..84a41943a801d5 100644
--- a/deps/ngtcp2/ngtcp2/lib/ngtcp2_conn.c
+++ b/deps/ngtcp2/ngtcp2/lib/ngtcp2_conn.c
@@ -2174,18 +2174,14 @@ static uint8_t conn_pkt_flags_short(ngtcp2_conn *conn) {
 }
 
 /*
- * conn_cut_crypto_frame splits (*pfrc)->fr.stream by removing
- * |removed_data| from (*pfrc)->fr.stream.data[0].
- * (*pfrc)->fr.stream.data[0] must contain |removed_data|, and
- * (*pfrc)->fr.stream.datacnt >= 1.  New ngtcp2_frame_chain object
- * that contains |removed_data| is created, and pushed to
- * |crypto_strm| via ngtcp2_strm_streamfrq_push.  Because
- * (*pfrc)->fr.stream.datacnt cannot be changed, if it is not 1, new
- * ngtcp2_frame_chain object is created to contain the data before
- * |removed_data|.  Then *pfrc is deleted, and the newly created
- * object is assigned to *pfrc instead.  If there are data following
- * the removed part of data, new ngtcp2_frame_chain object is created
- * for it, and (*pfrc)->next points to the object.
+ * conn_cut_crypto_frame splits frc->fr.stream by removing
+ * |removed_data| from frc->fr.stream.data[0].  frc->fr.stream.data[0]
+ * must contain |removed_data|, and frc->fr.stream.datacnt >= 1.  New
+ * ngtcp2_frame_chain object that contains |removed_data| is created,
+ * and pushed to |crypto_strm| via ngtcp2_strm_streamfrq_push.  If
+ * there are data following the removed part of data, new
+ * ngtcp2_frame_chain object is created for it, and frc->next points
+ * to the object.
  *
  * This function returns 0 if it succeeds, or one of the following
  * negative error codes:
@@ -2193,13 +2189,13 @@ static uint8_t conn_pkt_flags_short(ngtcp2_conn *conn) {
  * NGTCP2_ERR_NOMEM
  *     Out of memory
  */
-static int conn_cut_crypto_frame(ngtcp2_conn *conn, ngtcp2_frame_chain **pfrc,
+static int conn_cut_crypto_frame(ngtcp2_conn *conn, ngtcp2_frame_chain *frc,
                                  ngtcp2_strm *crypto_strm,
                                  const ngtcp2_vec *removed_data) {
-  ngtcp2_vec *data = (*pfrc)->fr.stream.data;
-  size_t datacnt = (*pfrc)->fr.stream.datacnt;
+  ngtcp2_vec *data = frc->fr.stream.data;
+  size_t datacnt = frc->fr.stream.datacnt;
   size_t ndatacnt;
-  ngtcp2_frame_chain *left_frc, *right_frc = NULL, *removed_frc;
+  ngtcp2_frame_chain *right_frc = NULL, *removed_frc;
   size_t offset;
   int rv;
 
@@ -2220,7 +2216,7 @@ static int conn_cut_crypto_frame(ngtcp2_conn *conn, ngtcp2_frame_chain **pfrc,
   removed_frc->fr.stream.flags = 0;
   removed_frc->fr.stream.fin = 0;
   removed_frc->fr.stream.stream_id = 0;
-  removed_frc->fr.stream.offset = (*pfrc)->fr.stream.offset + offset;
+  removed_frc->fr.stream.offset = frc->fr.stream.offset + offset;
   removed_frc->fr.stream.datacnt = 1;
   removed_frc->fr.stream.data[0] = (ngtcp2_vec){
     .base = data->base + offset,
@@ -2259,35 +2255,9 @@ static int conn_cut_crypto_frame(ngtcp2_conn *conn, ngtcp2_frame_chain **pfrc,
     assert(1 == datacnt);
   }
 
-  /* We cannot change (*pfrc)->fr.stream.datacnt.  If it changes,
-     create new ngtcp2_frame_chain. */
-  if ((*pfrc)->fr.stream.datacnt == 1) {
-    (*pfrc)->fr.stream.data[0].len = offset;
-    (*pfrc)->next = right_frc;
-    return 0;
-  }
-
-  rv = ngtcp2_frame_chain_stream_datacnt_objalloc_new(
-    &left_frc, 1, &conn->frc_objalloc, conn->mem);
-  if (rv != 0) {
-    ngtcp2_frame_chain_objalloc_del(right_frc, &conn->frc_objalloc, conn->mem);
-    return rv;
-  }
-
-  left_frc->fr.stream.type = NGTCP2_FRAME_CRYPTO;
-  left_frc->fr.stream.flags = 0;
-  left_frc->fr.stream.fin = 0;
-  left_frc->fr.stream.stream_id = 0;
-  left_frc->fr.stream.offset = (*pfrc)->fr.stream.offset;
-  left_frc->fr.stream.datacnt = 1;
-  left_frc->fr.stream.data[0] = (ngtcp2_vec){
-    .base = data[0].base,
-    .len = offset,
-  };
-  left_frc->next = right_frc;
-
-  ngtcp2_frame_chain_objalloc_del(*pfrc, &conn->frc_objalloc, conn->mem);
-  *pfrc = left_frc;
+  frc->fr.stream.datacnt = 1;
+  frc->fr.stream.data[0].len = offset;
+  frc->next = right_frc;
 
   return 0;
 }
@@ -2371,7 +2341,7 @@ conn_crumble_initial_crypto(ngtcp2_conn *conn, ngtcp2_frame_chain **pfrc,
       datacnt = ngtcp2_pkt_remove_vec_partial(
         &removed_data, data, datacnt, offsets, &conn->pcg, &server_name);
 
-      rv = conn_cut_crypto_frame(conn, pfrc, crypto_strm, &removed_data);
+      rv = conn_cut_crypto_frame(conn, *pfrc, crypto_strm, &removed_data);
       if (rv != 0) {
         ngtcp2_frame_chain_objalloc_del(*pfrc, &conn->frc_objalloc, conn->mem);
         return rv;
@@ -2635,7 +2605,9 @@ conn_write_handshake_pkt(ngtcp2_conn *conn, ngtcp2_pkt_info *pi, uint8_t *dest,
 
     if (!(rtb_entry_flags & NGTCP2_RTB_ENTRY_FLAG_ACK_ELICITING) &&
         pktns->rtb.num_retransmittable && pktns->rtb.probe_pkt_left) {
-      num_reclaimed = ngtcp2_rtb_reclaim_on_pto(&pktns->rtb, conn, pktns, 1);
+      num_reclaimed = ngtcp2_rtb_reclaim_on_pto(
+        &pktns->rtb, conn, pktns,
+        !conn->server && type == NGTCP2_PKT_INITIAL ? 2 : 1);
       if (num_reclaimed < 0) {
         ngtcp2_frame_chain_list_objalloc_del(frq, &conn->frc_objalloc,
                                              conn->mem);
@@ -5566,14 +5538,10 @@ static int conn_recv_ack(ngtcp2_conn *conn, ngtcp2_pktns *pktns, ngtcp2_ack *fr,
 
   num_acked =
     ngtcp2_rtb_recv_ack(&pktns->rtb, fr, &conn->cstat, conn, pktns, pkt_ts, ts);
-  if (num_acked < 0) {
+  if (num_acked <= 0) {
     return (int)num_acked;
   }
 
-  if (num_acked == 0) {
-    return 0;
-  }
-
   pktns->rtb.probe_pkt_left = 0;
 
   if (cstat->pto_count &&
@@ -11744,21 +11712,18 @@ int ngtcp2_conn_set_0rtt_remote_transport_params(
   /* These parameters are treated specially.  If server accepts early
      data, it must not set values for these parameters that are
      smaller than these remembered values. */
-  conn->early.transport_params.initial_max_streams_bidi =
-    params->initial_max_streams_bidi;
-  conn->early.transport_params.initial_max_streams_uni =
-    params->initial_max_streams_uni;
-  conn->early.transport_params.initial_max_stream_data_bidi_local =
-    params->initial_max_stream_data_bidi_local;
-  conn->early.transport_params.initial_max_stream_data_bidi_remote =
-    params->initial_max_stream_data_bidi_remote;
-  conn->early.transport_params.initial_max_stream_data_uni =
-    params->initial_max_stream_data_uni;
-  conn->early.transport_params.initial_max_data = params->initial_max_data;
-  conn->early.transport_params.active_connection_id_limit =
-    params->active_connection_id_limit;
-  conn->early.transport_params.max_datagram_frame_size =
-    params->max_datagram_frame_size;
+  conn->early.transport_params = (ngtcp2_early_transport_params){
+    .initial_max_streams_bidi = params->initial_max_streams_bidi,
+    .initial_max_streams_uni = params->initial_max_streams_uni,
+    .initial_max_stream_data_bidi_local =
+      params->initial_max_stream_data_bidi_local,
+    .initial_max_stream_data_bidi_remote =
+      params->initial_max_stream_data_bidi_remote,
+    .initial_max_stream_data_uni = params->initial_max_stream_data_uni,
+    .initial_max_data = params->initial_max_data,
+    .active_connection_id_limit = params->active_connection_id_limit,
+    .max_datagram_frame_size = params->max_datagram_frame_size,
+  };
 
   conn_sync_stream_id_limit(conn);
 
@@ -12003,12 +11968,17 @@ ngtcp2_ssize ngtcp2_conn_writev_stream_versioned(
         return NGTCP2_ERR_INVALID_ARGUMENT;
       }
 
-      vmsg.type = NGTCP2_VMSG_TYPE_STREAM;
-      vmsg.stream.strm = strm;
-      vmsg.stream.flags = flags;
-      vmsg.stream.data = datav;
-      vmsg.stream.datacnt = datavcnt;
-      vmsg.stream.pdatalen = pdatalen;
+      vmsg = (ngtcp2_vmsg){
+        .type = NGTCP2_VMSG_TYPE_STREAM,
+        .stream =
+          {
+            .strm = strm,
+            .data = datav,
+            .datacnt = datavcnt,
+            .pdatalen = pdatalen,
+            .flags = flags,
+          },
+      };
 
       pvmsg = &vmsg;
     }
@@ -12081,12 +12051,17 @@ ngtcp2_ssize ngtcp2_conn_writev_datagram_versioned(
     return NGTCP2_ERR_INVALID_ARGUMENT;
   }
 
-  vmsg.type = NGTCP2_VMSG_TYPE_DATAGRAM;
-  vmsg.datagram.dgram_id = dgram_id;
-  vmsg.datagram.flags = flags;
-  vmsg.datagram.data = datav;
-  vmsg.datagram.datacnt = datavcnt;
-  vmsg.datagram.paccepted = paccepted;
+  vmsg = (ngtcp2_vmsg){
+    .type = NGTCP2_VMSG_TYPE_DATAGRAM,
+    .datagram =
+      {
+        .data = datav,
+        .datacnt = datavcnt,
+        .dgram_id = dgram_id,
+        .paccepted = paccepted,
+        .flags = flags,
+      },
+  };
 
   if (flags & NGTCP2_WRITE_DATAGRAM_FLAG_PADDING) {
     wflags = NGTCP2_WRITE_PKT_FLAG_PADDING_IF_NOT_EMPTY;
diff --git a/deps/ngtcp2/ngtcp2/lib/ngtcp2_conn.h b/deps/ngtcp2/ngtcp2/lib/ngtcp2_conn.h
index 6c11e324173327..a6f7616ee0c7d6 100644
--- a/deps/ngtcp2/ngtcp2/lib/ngtcp2_conn.h
+++ b/deps/ngtcp2/ngtcp2/lib/ngtcp2_conn.h
@@ -114,7 +114,7 @@ typedef enum {
 
 typedef struct ngtcp2_path_challenge_entry {
   ngtcp2_path_storage ps;
-  uint8_t data[8];
+  uint8_t data[NGTCP2_PATH_CHALLENGE_DATALEN];
 } ngtcp2_path_challenge_entry;
 
 void ngtcp2_path_challenge_entry_init(ngtcp2_path_challenge_entry *pcent,
@@ -387,14 +387,14 @@ struct ngtcp2_conn {
     ngtcp2_tstamp last_max_data_ts;
 
     struct {
-      /* state is the state of ECN validation */
-      ngtcp2_ecn_state state;
       /* validation_start_ts is the timestamp when ECN validation is
          started.  It is UINT64_MAX if it has not started yet. */
       ngtcp2_tstamp validation_start_ts;
       /* dgram_sent is the number of UDP datagram sent during ECN
          validation period. */
       size_t dgram_sent;
+      /* state is the state of ECN validation */
+      ngtcp2_ecn_state state;
     } ecn;
 
     struct {
@@ -545,13 +545,13 @@ struct ngtcp2_conn {
     /* retry_aead_ctx is AEAD cipher context to verify Retry packet
        integrity.  It is used by client only. */
     ngtcp2_crypto_aead_ctx retry_aead_ctx;
+    /* decryption_failure_count is the number of received packets that
+       fail authentication. */
+    uint64_t decryption_failure_count;
     /* tls_error is TLS related error. */
     int tls_error;
     /* tls_alert is TLS alert generated by the local endpoint. */
     uint8_t tls_alert;
-    /* decryption_failure_count is the number of received packets that
-       fail authentication. */
-    uint64_t decryption_failure_count;
   } crypto;
 
   /* pkt contains the packet intermediate construction data to support
@@ -561,13 +561,13 @@ struct ngtcp2_conn {
     ngtcp2_pkt_hd hd;
     ngtcp2_ppe ppe;
     ngtcp2_frame_chain **pfrc;
+    ngtcp2_ssize hs_spktlen;
     int pkt_empty;
     int hd_logged;
+    int require_padding;
     /* flags is bitwise OR of zero or more of
        NGTCP2_RTB_ENTRY_FLAG_*. */
     uint16_t rtb_entry_flags;
-    ngtcp2_ssize hs_spktlen;
-    int require_padding;
   } pkt;
 
   struct {
@@ -623,7 +623,6 @@ struct ngtcp2_conn {
   ngtcp2_log log;
   ngtcp2_qlog qlog;
   ngtcp2_rst rst;
-  ngtcp2_cc_algo cc_algo;
   union {
     ngtcp2_cc cc;
     ngtcp2_cc_reno reno;
@@ -650,6 +649,7 @@ struct ngtcp2_conn {
   uint32_t negotiated_version;
   /* flags is bitwise OR of zero or more of NGTCP2_CONN_FLAG_*. */
   uint32_t flags;
+  ngtcp2_cc_algo cc_algo;
   int server;
 };
 
@@ -661,9 +661,6 @@ typedef enum ngtcp2_vmsg_type {
 typedef struct ngtcp2_vmsg_stream {
   /* strm is a stream that data is sent to. */
   ngtcp2_strm *strm;
-  /* flags is bitwise OR of zero or more of
-     NGTCP2_WRITE_STREAM_FLAG_*. */
-  uint32_t flags;
   /* data is the pointer to ngtcp2_vec array which contains the stream
      data to send. */
   const ngtcp2_vec *data;
@@ -672,6 +669,9 @@ typedef struct ngtcp2_vmsg_stream {
   /* pdatalen is the pointer to the variable which the number of bytes
      written is assigned to if pdatalen is not NULL. */
   ngtcp2_ssize *pdatalen;
+  /* flags is bitwise OR of zero or more of
+     NGTCP2_WRITE_STREAM_FLAG_*. */
+  uint32_t flags;
 } ngtcp2_vmsg_stream;
 
 typedef struct ngtcp2_vmsg_datagram {
@@ -682,12 +682,12 @@ typedef struct ngtcp2_vmsg_datagram {
   size_t datacnt;
   /* dgram_id is an opaque identifier chosen by an application. */
   uint64_t dgram_id;
-  /* flags is bitwise OR of zero or more of
-     NGTCP2_WRITE_DATAGRAM_FLAG_*. */
-  uint32_t flags;
   /* paccepted is the pointer to the variable which, if it is not
      NULL, is assigned nonzero if data is written to a packet. */
   int *paccepted;
+  /* flags is bitwise OR of zero or more of
+     NGTCP2_WRITE_DATAGRAM_FLAG_*. */
+  uint32_t flags;
 } ngtcp2_vmsg_datagram;
 
 typedef struct ngtcp2_vmsg {
diff --git a/deps/ngtcp2/ngtcp2/lib/ngtcp2_frame_chain.c b/deps/ngtcp2/ngtcp2/lib/ngtcp2_frame_chain.c
index dc17d576b8044b..ec0839b7a4d126 100644
--- a/deps/ngtcp2/ngtcp2/lib/ngtcp2_frame_chain.c
+++ b/deps/ngtcp2/ngtcp2/lib/ngtcp2_frame_chain.c
@@ -36,7 +36,7 @@ int ngtcp2_frame_chain_objalloc_new(ngtcp2_frame_chain **pfrc,
     return NGTCP2_ERR_NOMEM;
   }
 
-  ngtcp2_frame_chain_init(*pfrc);
+  ngtcp2_frame_chain_init(*pfrc, NGTCP2_FRAME_CHAIN_FLAG_NONE);
 
   return 0;
 }
@@ -48,7 +48,7 @@ int ngtcp2_frame_chain_extralen_new(ngtcp2_frame_chain **pfrc, size_t extralen,
     return NGTCP2_ERR_NOMEM;
   }
 
-  ngtcp2_frame_chain_init(*pfrc);
+  ngtcp2_frame_chain_init(*pfrc, NGTCP2_FRAME_CHAIN_FLAG_MALLOC);
 
   return 0;
 }
@@ -110,21 +110,6 @@ int ngtcp2_frame_chain_new_token_objalloc_new(ngtcp2_frame_chain **pfrc,
   return 0;
 }
 
-void ngtcp2_frame_chain_del(ngtcp2_frame_chain *frc, const ngtcp2_mem *mem) {
-  ngtcp2_frame_chain_binder *binder;
-
-  if (frc == NULL) {
-    return;
-  }
-
-  binder = frc->binder;
-  if (binder && --binder->refcount == 0) {
-    ngtcp2_mem_free(mem, binder);
-  }
-
-  ngtcp2_mem_free(mem, frc);
-}
-
 void ngtcp2_frame_chain_objalloc_del(ngtcp2_frame_chain *frc,
                                      ngtcp2_objalloc *objalloc,
                                      const ngtcp2_mem *mem) {
@@ -134,39 +119,23 @@ void ngtcp2_frame_chain_objalloc_del(ngtcp2_frame_chain *frc,
     return;
   }
 
-  switch (frc->fr.hd.type) {
-  case NGTCP2_FRAME_CRYPTO:
-  case NGTCP2_FRAME_STREAM:
-    if (frc->fr.stream.datacnt > NGTCP2_FRAME_CHAIN_STREAM_DATACNT_THRES) {
-      ngtcp2_frame_chain_del(frc, mem);
-
-      return;
-    }
-
-    break;
-  case NGTCP2_FRAME_NEW_TOKEN:
-    if (frc->fr.new_token.tokenlen > NGTCP2_FRAME_CHAIN_NEW_TOKEN_THRES) {
-      ngtcp2_frame_chain_del(frc, mem);
-
-      return;
-    }
-
-    break;
-  }
-
   binder = frc->binder;
   if (binder && --binder->refcount == 0) {
     ngtcp2_mem_free(mem, binder);
   }
 
-  frc->binder = NULL;
+  if (frc->flags & NGTCP2_FRAME_CHAIN_FLAG_MALLOC) {
+    ngtcp2_mem_free(mem, frc);
+    return;
+  }
 
   ngtcp2_objalloc_frame_chain_release(objalloc, frc);
 }
 
-void ngtcp2_frame_chain_init(ngtcp2_frame_chain *frc) {
+void ngtcp2_frame_chain_init(ngtcp2_frame_chain *frc, uint32_t flags) {
   frc->next = NULL;
   frc->binder = NULL;
+  frc->flags = flags;
 }
 
 void ngtcp2_frame_chain_list_objalloc_del(ngtcp2_frame_chain *frc,
diff --git a/deps/ngtcp2/ngtcp2/lib/ngtcp2_frame_chain.h b/deps/ngtcp2/ngtcp2/lib/ngtcp2_frame_chain.h
index aa8ce4958386c9..5342b9fa7b1692 100644
--- a/deps/ngtcp2/ngtcp2/lib/ngtcp2_frame_chain.h
+++ b/deps/ngtcp2/ngtcp2/lib/ngtcp2_frame_chain.h
@@ -70,6 +70,12 @@ int ngtcp2_frame_chain_binder_new(ngtcp2_frame_chain_binder **pbinder,
 #define NGTCP2_FRAME_CHAIN_NEW_TOKEN_THRES                                     \
   (NGTCP2_FRAME_CHAIN_STREAM_DATACNT_THRES * sizeof(ngtcp2_vec))
 
+/* NGTCP2_FRAME_CHAIN_FLAG_NONE indicates no flag is set. */
+#define NGTCP2_FRAME_CHAIN_FLAG_NONE 0x0
+/* NGTCP2_FRAME_CHAIN_FLAG_MALLOC indicates that ngtcp2_frame_chain is
+   allocated by ngtcp2_mem_malloc. */
+#define NGTCP2_FRAME_CHAIN_FLAG_MALLOC 0x1
+
 typedef struct ngtcp2_frame_chain ngtcp2_frame_chain;
 
 /*
@@ -80,6 +86,7 @@ struct ngtcp2_frame_chain {
     struct {
       ngtcp2_frame_chain *next;
       ngtcp2_frame_chain_binder *binder;
+      uint32_t flags;
       ngtcp2_frame fr;
       uint8_t buf[sizeof(ngtcp2_vec) * NGTCP2_FRAME_CHAIN_STREAM_DATACNT_THRES];
     };
@@ -125,8 +132,6 @@ int ngtcp2_frame_chain_extralen_new(ngtcp2_frame_chain **pfrc, size_t extralen,
  * words, |datacnt| <= NGTCP2_FRAME_CHAIN_STREAM_DATACNT_THRES,
  * ngtcp2_frame_chain_objalloc_new is called internally.  Otherwise,
  * ngtcp2_frame_chain_extralen_new is used and objalloc is not used.
- * Therefore, it is important to call ngtcp2_frame_chain_objalloc_del
- * without changing datacnt field.
  */
 int ngtcp2_frame_chain_stream_datacnt_objalloc_new(ngtcp2_frame_chain **pfrc,
                                                    size_t datacnt,
@@ -147,24 +152,19 @@ int ngtcp2_frame_chain_new_token_objalloc_new(ngtcp2_frame_chain **pfrc,
                                               const ngtcp2_mem *mem);
 
 /*
- * ngtcp2_frame_chain_del deallocates |frc|.  It also deallocates the
- * memory pointed by |frc|.
- */
-void ngtcp2_frame_chain_del(ngtcp2_frame_chain *frc, const ngtcp2_mem *mem);
-
-/*
- * ngtcp2_frame_chain_objalloc_del adds |frc| to |objalloc| for reuse.
- * It might just delete |frc| depending on the frame type and the size
- * of |frc|.
+ * ngtcp2_frame_chain_objalloc_del adds |frc| to |objalloc| for reuse
+ * if NGTCP2_FRAME_CHAIN_FLAG_MALLOC is not set in |frc|->flags.
+ * Otherwise, it deletes |frc|.
  */
 void ngtcp2_frame_chain_objalloc_del(ngtcp2_frame_chain *frc,
                                      ngtcp2_objalloc *objalloc,
                                      const ngtcp2_mem *mem);
 
 /*
- * ngtcp2_frame_chain_init initializes |frc|.
+ * ngtcp2_frame_chain_init initializes |frc|.  |flags| is bitwise-OR
+ * of zero or more of NGTCP2_FRAME_CHAIN_FLAG_*.
  */
-void ngtcp2_frame_chain_init(ngtcp2_frame_chain *frc);
+void ngtcp2_frame_chain_init(ngtcp2_frame_chain *frc, uint32_t flags);
 
 /*
  * ngtcp2_frame_chain_list_objalloc_del adds all ngtcp2_frame_chain
diff --git a/deps/ngtcp2/ngtcp2/lib/ngtcp2_ksl.c b/deps/ngtcp2/ngtcp2/lib/ngtcp2_ksl.c
index 03a95b9319a45d..0c1c0a36c5bcf9 100644
--- a/deps/ngtcp2/ngtcp2/lib/ngtcp2_ksl.c
+++ b/deps/ngtcp2/ngtcp2/lib/ngtcp2_ksl.c
@@ -58,11 +58,13 @@ void ngtcp2_ksl_init(ngtcp2_ksl *ksl, ngtcp2_ksl_compar compar,
 
   aligned_keylen = (keylen + 0x7u) & ~0x7u;
 
+  assert(aligned_keylen <= UINT16_MAX);
+
   ngtcp2_objalloc_init(&ksl->blkalloc,
                        (ksl_blklen(aligned_keylen) + 0xfu) & ~(uintptr_t)0xfu,
                        mem);
 
-  ksl->head = NULL;
+  ksl->root = NULL;
   ksl->front = ksl->back = NULL;
   ksl->compar = compar;
   ksl->search = search;
@@ -80,6 +82,7 @@ static ngtcp2_ksl_blk *ksl_blk_objalloc_new(ngtcp2_ksl *ksl) {
   }
 
   blk->keys = (uint8_t *)blk + sizeof(*blk);
+  blk->aligned_keylen = (uint16_t)ksl->aligned_keylen;
 
   return blk;
 }
@@ -88,19 +91,19 @@ static void ksl_blk_objalloc_del(ngtcp2_ksl *ksl, ngtcp2_ksl_blk *blk) {
   ngtcp2_objalloc_ksl_blk_release(&ksl->blkalloc, blk);
 }
 
-static int ksl_head_init(ngtcp2_ksl *ksl) {
-  ngtcp2_ksl_blk *head = ksl_blk_objalloc_new(ksl);
+static int ksl_root_init(ngtcp2_ksl *ksl) {
+  ngtcp2_ksl_blk *root = ksl_blk_objalloc_new(ksl);
 
-  if (!head) {
+  if (!root) {
     return NGTCP2_ERR_NOMEM;
   }
 
-  head->next = head->prev = NULL;
-  head->n = 0;
-  head->leaf = 1;
+  root->next = root->prev = NULL;
+  root->n = 0;
+  root->leaf = 1;
 
-  ksl->head = head;
-  ksl->front = ksl->back = head;
+  ksl->root = root;
+  ksl->front = ksl->back = root;
 
   return 0;
 }
@@ -123,12 +126,12 @@ static void ksl_free_blk(ngtcp2_ksl *ksl, ngtcp2_ksl_blk *blk) {
 #endif /* defined(NOMEMPOOL) */
 
 void ngtcp2_ksl_free(ngtcp2_ksl *ksl) {
-  if (!ksl || !ksl->head) {
+  if (!ksl || !ksl->root) {
     return;
   }
 
 #ifdef NOMEMPOOL
-  ksl_free_blk(ksl, ksl->head);
+  ksl_free_blk(ksl, ksl->root);
 #endif /* defined(NOMEMPOOL) */
 
   ngtcp2_objalloc_free(&ksl->blkalloc);
@@ -198,22 +201,21 @@ static int ksl_split_node(ngtcp2_ksl *ksl, ngtcp2_ksl_blk *blk, size_t i) {
   memmove(blk->nodes + (i + 2), blk->nodes + (i + 1),
           (blk->n - (i + 1)) * sizeof(ngtcp2_ksl_node));
 
-  memmove(blk->keys + (i + 2) * ksl->aligned_keylen,
-          blk->keys + (i + 1) * ksl->aligned_keylen,
-          (blk->n - (i + 1)) * ksl->aligned_keylen);
+  memmove(blk->keys + (i + 1) * ksl->aligned_keylen,
+          blk->keys + i * ksl->aligned_keylen,
+          (blk->n - i) * ksl->aligned_keylen);
 
   blk->nodes[i + 1].blk = rblk;
   ++blk->n;
-  ksl_set_nth_key(ksl, blk, i + 1, ngtcp2_ksl_nth_key(ksl, rblk, rblk->n - 1));
 
-  ksl_set_nth_key(ksl, blk, i, ngtcp2_ksl_nth_key(ksl, lblk, lblk->n - 1));
+  ksl_set_nth_key(ksl, blk, i, ngtcp2_ksl_blk_nth_key(lblk, lblk->n - 1));
 
   return 0;
 }
 
 /*
- * ksl_split_head splits a head (root) block.  It increases the height
- * of skip list by 1.
+ * ksl_split_root splits a root block.  It increases the height of
+ * skip list by 1.
  *
  * It returns 0 if it succeeds, or one of the following negative error
  * codes:
@@ -221,34 +223,34 @@ static int ksl_split_node(ngtcp2_ksl *ksl, ngtcp2_ksl_blk *blk, size_t i) {
  * NGTCP2_ERR_NOMEM
  *     Out of memory.
  */
-static int ksl_split_head(ngtcp2_ksl *ksl) {
-  ngtcp2_ksl_blk *rblk = NULL, *lblk, *nhead = NULL;
+static int ksl_split_root(ngtcp2_ksl *ksl) {
+  ngtcp2_ksl_blk *rblk = NULL, *lblk, *nroot = NULL;
 
-  rblk = ksl_split_blk(ksl, ksl->head);
+  rblk = ksl_split_blk(ksl, ksl->root);
   if (rblk == NULL) {
     return NGTCP2_ERR_NOMEM;
   }
 
-  lblk = ksl->head;
+  lblk = ksl->root;
 
-  nhead = ksl_blk_objalloc_new(ksl);
+  nroot = ksl_blk_objalloc_new(ksl);
 
-  if (nhead == NULL) {
+  if (nroot == NULL) {
     ksl_blk_objalloc_del(ksl, rblk);
     return NGTCP2_ERR_NOMEM;
   }
 
-  nhead->next = nhead->prev = NULL;
-  nhead->n = 2;
-  nhead->leaf = 0;
+  nroot->next = nroot->prev = NULL;
+  nroot->n = 2;
+  nroot->leaf = 0;
 
-  ksl_set_nth_key(ksl, nhead, 0, ngtcp2_ksl_nth_key(ksl, lblk, lblk->n - 1));
-  nhead->nodes[0].blk = lblk;
+  ksl_set_nth_key(ksl, nroot, 0, ngtcp2_ksl_blk_nth_key(lblk, lblk->n - 1));
+  nroot->nodes[0].blk = lblk;
 
-  ksl_set_nth_key(ksl, nhead, 1, ngtcp2_ksl_nth_key(ksl, rblk, rblk->n - 1));
-  nhead->nodes[1].blk = rblk;
+  ksl_set_nth_key(ksl, nroot, 1, ngtcp2_ksl_blk_nth_key(rblk, rblk->n - 1));
+  nroot->nodes[1].blk = rblk;
 
-  ksl->head = nhead;
+  ksl->root = nroot;
 
   return 0;
 }
@@ -283,27 +285,27 @@ int ngtcp2_ksl_insert(ngtcp2_ksl *ksl, ngtcp2_ksl_it *it,
   size_t i;
   int rv;
 
-  if (!ksl->head) {
-    rv = ksl_head_init(ksl);
+  if (!ksl->root) {
+    rv = ksl_root_init(ksl);
     if (rv != 0) {
       return rv;
     }
   }
 
-  if (ksl->head->n == NGTCP2_KSL_MAX_NBLK) {
-    rv = ksl_split_head(ksl);
+  if (ksl->root->n == NGTCP2_KSL_MAX_NBLK) {
+    rv = ksl_split_root(ksl);
     if (rv != 0) {
       return rv;
     }
   }
 
-  blk = ksl->head;
+  blk = ksl->root;
 
   for (;;) {
     i = ksl->search(ksl, blk, key);
 
     if (blk->leaf) {
-      if (i < blk->n && !ksl->compar(key, ngtcp2_ksl_nth_key(ksl, blk, i))) {
+      if (i < blk->n && !ksl->compar(key, ngtcp2_ksl_blk_nth_key(blk, i))) {
         if (it) {
           *it = ngtcp2_ksl_end(ksl);
         }
@@ -315,7 +317,7 @@ int ngtcp2_ksl_insert(ngtcp2_ksl *ksl, ngtcp2_ksl_it *it,
       ++ksl->n;
 
       if (it) {
-        ngtcp2_ksl_it_init(it, ksl, blk, i);
+        ngtcp2_ksl_it_init(it, blk, i);
       }
 
       return 0;
@@ -342,7 +344,7 @@ int ngtcp2_ksl_insert(ngtcp2_ksl *ksl, ngtcp2_ksl_it *it,
       ++ksl->n;
 
       if (it) {
-        ngtcp2_ksl_it_init(it, ksl, blk, blk->n - 1);
+        ngtcp2_ksl_it_init(it, blk, blk->n - 1);
       }
 
       return 0;
@@ -356,12 +358,8 @@ int ngtcp2_ksl_insert(ngtcp2_ksl *ksl, ngtcp2_ksl_it *it,
         return rv;
       }
 
-      if (ksl->compar(ngtcp2_ksl_nth_key(ksl, blk, i), key)) {
+      if (ksl->compar(ngtcp2_ksl_blk_nth_key(blk, i), key)) {
         node = &blk->nodes[i + 1];
-
-        if (ksl->compar(ngtcp2_ksl_nth_key(ksl, blk, i + 1), key)) {
-          ksl_set_nth_key(ksl, blk, i + 1, key);
-        }
       }
     }
 
@@ -388,9 +386,9 @@ static void ksl_remove_node(ngtcp2_ksl *ksl, ngtcp2_ksl_blk *blk, size_t i) {
  * ksl_merge_node merges 2 nodes which are the nodes at the index of
  * |i| and |i + 1|.
  *
- * If |blk| is the head (root) block and it contains just 2 nodes
- * before merging nodes, the merged block becomes head block, which
- * decreases the height of |ksl| by 1.
+ * If |blk| is the root block and it contains just 2 nodes before
+ * merging nodes, the merged block becomes root block, which decreases
+ * the height of |ksl| by 1.
  *
  * This function returns the pointer to the merged block.
  */
@@ -406,7 +404,7 @@ static ngtcp2_ksl_blk *ksl_merge_node(ngtcp2_ksl *ksl, ngtcp2_ksl_blk *blk,
   lblk = lnode->blk;
   rblk = blk->nodes[i + 1].blk;
 
-  assert(lblk->n + rblk->n < NGTCP2_KSL_MAX_NBLK);
+  assert(lblk->n + rblk->n <= NGTCP2_KSL_MAX_NBLK);
 
   memcpy(lblk->nodes + lblk->n, rblk->nodes, rblk->n * sizeof(ngtcp2_ksl_node));
 
@@ -424,12 +422,12 @@ static ngtcp2_ksl_blk *ksl_merge_node(ngtcp2_ksl *ksl, ngtcp2_ksl_blk *blk,
 
   ksl_blk_objalloc_del(ksl, rblk);
 
-  if (ksl->head == blk && blk->n == 2) {
-    ksl_blk_objalloc_del(ksl, ksl->head);
-    ksl->head = lblk;
+  if (ksl->root == blk && blk->n == 2) {
+    ksl_blk_objalloc_del(ksl, ksl->root);
+    ksl->root = lblk;
   } else {
     ksl_remove_node(ksl, blk, i + 1);
-    ksl_set_nth_key(ksl, blk, i, ngtcp2_ksl_nth_key(ksl, lblk, lblk->n - 1));
+    ksl_set_nth_key(ksl, blk, i, ngtcp2_ksl_blk_nth_key(lblk, lblk->n - 1));
   }
 
   return lblk;
@@ -470,7 +468,7 @@ static void ksl_shift_left(ngtcp2_ksl *ksl, ngtcp2_ksl_blk *blk, size_t i) {
   lblk->n += (uint32_t)n;
   rblk->n -= (uint32_t)n;
 
-  ksl_set_nth_key(ksl, blk, i - 1, ngtcp2_ksl_nth_key(ksl, lblk, lblk->n - 1));
+  ksl_set_nth_key(ksl, blk, i - 1, ngtcp2_ksl_blk_nth_key(lblk, lblk->n - 1));
 
   memmove(rblk->nodes, rblk->nodes + n, rblk->n * sizeof(ngtcp2_ksl_node));
 
@@ -518,7 +516,7 @@ static void ksl_shift_right(ngtcp2_ksl *ksl, ngtcp2_ksl_blk *blk, size_t i) {
   memcpy(rblk->keys, lblk->keys + lblk->n * ksl->aligned_keylen,
          n * ksl->aligned_keylen);
 
-  ksl_set_nth_key(ksl, blk, i, ngtcp2_ksl_nth_key(ksl, lblk, lblk->n - 1));
+  ksl_set_nth_key(ksl, blk, i, ngtcp2_ksl_blk_nth_key(lblk, lblk->n - 1));
 }
 
 /*
@@ -535,9 +533,9 @@ int ngtcp2_ksl_remove_hint(ngtcp2_ksl *ksl, ngtcp2_ksl_it *it,
                            const ngtcp2_ksl_key *key) {
   ngtcp2_ksl_blk *blk = hint->blk;
 
-  assert(ksl->head);
+  assert(ksl->root);
 
-  if (blk->n <= NGTCP2_KSL_MIN_NBLK) {
+  if (blk != ksl->root && blk->n == NGTCP2_KSL_MIN_NBLK) {
     return ngtcp2_ksl_remove(ksl, it, key);
   }
 
@@ -547,9 +545,9 @@ int ngtcp2_ksl_remove_hint(ngtcp2_ksl *ksl, ngtcp2_ksl_it *it,
 
   if (it) {
     if (hint->i == blk->n && blk->next) {
-      ngtcp2_ksl_it_init(it, ksl, blk->next, 0);
+      ngtcp2_ksl_it_init(it, blk->next, 0);
     } else {
-      ngtcp2_ksl_it_init(it, ksl, blk, hint->i);
+      ngtcp2_ksl_it_init(it, blk, hint->i);
     }
   }
 
@@ -558,7 +556,7 @@ int ngtcp2_ksl_remove_hint(ngtcp2_ksl *ksl, ngtcp2_ksl_it *it,
 
 int ngtcp2_ksl_remove(ngtcp2_ksl *ksl, ngtcp2_ksl_it *it,
                       const ngtcp2_ksl_key *key) {
-  ngtcp2_ksl_blk *blk = ksl->head;
+  ngtcp2_ksl_blk *blk = ksl->root;
   ngtcp2_ksl_node *node;
   size_t i;
 
@@ -584,7 +582,7 @@ int ngtcp2_ksl_remove(ngtcp2_ksl *ksl, ngtcp2_ksl_it *it,
     }
 
     if (blk->leaf) {
-      if (ksl->compar(key, ngtcp2_ksl_nth_key(ksl, blk, i))) {
+      if (ksl->compar(key, ngtcp2_ksl_blk_nth_key(blk, i))) {
         if (it) {
           *it = ngtcp2_ksl_end(ksl);
         }
@@ -597,9 +595,9 @@ int ngtcp2_ksl_remove(ngtcp2_ksl *ksl, ngtcp2_ksl_it *it,
 
       if (it) {
         if (blk->n == i && blk->next) {
-          ngtcp2_ksl_it_init(it, ksl, blk->next, 0);
+          ngtcp2_ksl_it_init(it, blk->next, 0);
         } else {
-          ngtcp2_ksl_it_init(it, ksl, blk, i);
+          ngtcp2_ksl_it_init(it, blk, i);
         }
       }
 
@@ -648,12 +646,12 @@ ngtcp2_ksl_it ngtcp2_ksl_lower_bound(const ngtcp2_ksl *ksl,
 ngtcp2_ksl_it ngtcp2_ksl_lower_bound_search(const ngtcp2_ksl *ksl,
                                             const ngtcp2_ksl_key *key,
                                             ngtcp2_ksl_search search) {
-  ngtcp2_ksl_blk *blk = ksl->head;
+  ngtcp2_ksl_blk *blk = ksl->root;
   ngtcp2_ksl_it it;
   size_t i;
 
   if (!blk) {
-    ngtcp2_ksl_it_init(&it, ksl, &null_blk, 0);
+    ngtcp2_ksl_it_init(&it, &null_blk, 0);
     return it;
   }
 
@@ -666,7 +664,7 @@ ngtcp2_ksl_it ngtcp2_ksl_lower_bound_search(const ngtcp2_ksl *ksl,
         i = 0;
       }
 
-      ngtcp2_ksl_it_init(&it, ksl, blk, i);
+      ngtcp2_ksl_it_init(&it, blk, i);
 
       return it;
     }
@@ -684,7 +682,7 @@ ngtcp2_ksl_it ngtcp2_ksl_lower_bound_search(const ngtcp2_ksl *ksl,
         i = blk->n;
       }
 
-      ngtcp2_ksl_it_init(&it, ksl, blk, i);
+      ngtcp2_ksl_it_init(&it, blk, i);
 
       return it;
     }
@@ -695,19 +693,19 @@ ngtcp2_ksl_it ngtcp2_ksl_lower_bound_search(const ngtcp2_ksl *ksl,
 
 void ngtcp2_ksl_update_key(ngtcp2_ksl *ksl, const ngtcp2_ksl_key *old_key,
                            const ngtcp2_ksl_key *new_key) {
-  ngtcp2_ksl_blk *blk = ksl->head;
+  ngtcp2_ksl_blk *blk = ksl->root;
   ngtcp2_ksl_node *node;
   const ngtcp2_ksl_key *node_key;
   size_t i;
 
-  assert(ksl->head);
+  assert(ksl->root);
 
   for (;;) {
     i = ksl->search(ksl, blk, old_key);
 
     assert(i < blk->n);
     node = &blk->nodes[i];
-    node_key = ngtcp2_ksl_nth_key(ksl, blk, i);
+    node_key = ngtcp2_ksl_blk_nth_key(blk, i);
 
     if (blk->leaf) {
       assert(key_equal(ksl->compar, node_key, old_key));
@@ -728,15 +726,15 @@ void ngtcp2_ksl_update_key(ngtcp2_ksl *ksl, const ngtcp2_ksl_key *old_key,
 size_t ngtcp2_ksl_len(const ngtcp2_ksl *ksl) { return ksl->n; }
 
 void ngtcp2_ksl_clear(ngtcp2_ksl *ksl) {
-  if (!ksl->head) {
+  if (!ksl->root) {
     return;
   }
 
 #ifdef NOMEMPOOL
-  ksl_free_blk(ksl, ksl->head);
+  ksl_free_blk(ksl, ksl->root);
 #endif /* defined(NOMEMPOOL) */
 
-  ksl->front = ksl->back = ksl->head = NULL;
+  ksl->front = ksl->back = ksl->root = NULL;
   ksl->n = 0;
 
   ngtcp2_objalloc_clear(&ksl->blkalloc);
@@ -751,7 +749,7 @@ static void ksl_print(const ngtcp2_ksl *ksl, ngtcp2_ksl_blk *blk,
 
   if (blk->leaf) {
     for (i = 0; i < blk->n; ++i) {
-      fprintf(stderr, " %" PRId64, *(int64_t *)ngtcp2_ksl_nth_key(ksl, blk, i));
+      fprintf(stderr, " %" PRId64, *(int64_t *)ngtcp2_ksl_blk_nth_key(blk, i));
     }
 
     fprintf(stderr, "\n");
@@ -765,21 +763,21 @@ static void ksl_print(const ngtcp2_ksl *ksl, ngtcp2_ksl_blk *blk,
 }
 
 void ngtcp2_ksl_print(const ngtcp2_ksl *ksl) {
-  if (!ksl->head) {
+  if (!ksl->root) {
     return;
   }
 
-  ksl_print(ksl, ksl->head, 0);
+  ksl_print(ksl, ksl->root, 0);
 }
 #endif /* !defined(WIN32) */
 
 ngtcp2_ksl_it ngtcp2_ksl_begin(const ngtcp2_ksl *ksl) {
   ngtcp2_ksl_it it;
 
-  if (ksl->head) {
-    ngtcp2_ksl_it_init(&it, ksl, ksl->front, 0);
+  if (ksl->root) {
+    ngtcp2_ksl_it_init(&it, ksl->front, 0);
   } else {
-    ngtcp2_ksl_it_init(&it, ksl, &null_blk, 0);
+    ngtcp2_ksl_it_init(&it, &null_blk, 0);
   }
 
   return it;
@@ -788,18 +786,16 @@ ngtcp2_ksl_it ngtcp2_ksl_begin(const ngtcp2_ksl *ksl) {
 ngtcp2_ksl_it ngtcp2_ksl_end(const ngtcp2_ksl *ksl) {
   ngtcp2_ksl_it it;
 
-  if (ksl->head) {
-    ngtcp2_ksl_it_init(&it, ksl, ksl->back, ksl->back->n);
+  if (ksl->root) {
+    ngtcp2_ksl_it_init(&it, ksl->back, ksl->back->n);
   } else {
-    ngtcp2_ksl_it_init(&it, ksl, &null_blk, 0);
+    ngtcp2_ksl_it_init(&it, &null_blk, 0);
   }
 
   return it;
 }
 
-void ngtcp2_ksl_it_init(ngtcp2_ksl_it *it, const ngtcp2_ksl *ksl,
-                        ngtcp2_ksl_blk *blk, size_t i) {
-  it->ksl = ksl;
+void ngtcp2_ksl_it_init(ngtcp2_ksl_it *it, ngtcp2_ksl_blk *blk, size_t i) {
   it->blk = blk;
   it->i = i;
 }
diff --git a/deps/ngtcp2/ngtcp2/lib/ngtcp2_ksl.h b/deps/ngtcp2/ngtcp2/lib/ngtcp2_ksl.h
index d35c83deab025d..cb972f94dca2e2 100644
--- a/deps/ngtcp2/ngtcp2/lib/ngtcp2_ksl.h
+++ b/deps/ngtcp2/ngtcp2/lib/ngtcp2_ksl.h
@@ -38,10 +38,10 @@
 #define NGTCP2_KSL_DEGR 16
 /* NGTCP2_KSL_MAX_NBLK is the maximum number of nodes which a single
    block can contain. */
-#define NGTCP2_KSL_MAX_NBLK (2 * NGTCP2_KSL_DEGR - 1)
+#define NGTCP2_KSL_MAX_NBLK (2 * NGTCP2_KSL_DEGR)
 /* NGTCP2_KSL_MIN_NBLK is the minimum number of nodes which a single
    block other than root must contain. */
-#define NGTCP2_KSL_MIN_NBLK (NGTCP2_KSL_DEGR - 1)
+#define NGTCP2_KSL_MIN_NBLK NGTCP2_KSL_DEGR
 
 /*
  * ngtcp2_ksl_key represents key in ngtcp2_ksl.
@@ -75,16 +75,19 @@ struct ngtcp2_ksl_blk {
       /* prev points to the previous block if leaf field is
          nonzero. */
       ngtcp2_ksl_blk *prev;
-      /* n is the number of nodes this object contains in nodes. */
-      uint32_t n;
-      /* leaf is nonzero if this block contains leaf nodes. */
-      uint32_t leaf;
       ngtcp2_ksl_node nodes[NGTCP2_KSL_MAX_NBLK];
       /* keys is a pointer to the buffer to include
          NGTCP2_KSL_MAX_NBLK keys.  Because the length of key is
          unknown until ngtcp2_ksl_init is called, the actual buffer
-         will be allocated after this field. */
+         will be allocated after this object. */
       uint8_t *keys;
+      /* n is the number of nodes this object contains in nodes. */
+      uint32_t n;
+      /* aligned_keylen is the length of the single key including
+         alignment. */
+      uint16_t aligned_keylen;
+      /* leaf is nonzero if this block contains leaf nodes. */
+      uint8_t leaf;
     };
 
     ngtcp2_opl_entry oplent;
@@ -134,7 +137,6 @@ typedef struct ngtcp2_ksl_it ngtcp2_ksl_it;
  * ngtcp2_ksl_it is a bidirectional iterator to iterate nodes.
  */
 struct ngtcp2_ksl_it {
-  const ngtcp2_ksl *ksl;
   ngtcp2_ksl_blk *blk;
   size_t i;
 };
@@ -144,8 +146,8 @@ struct ngtcp2_ksl_it {
  */
 struct ngtcp2_ksl {
   ngtcp2_objalloc blkalloc;
-  /* head points to the root block. */
-  ngtcp2_ksl_blk *head;
+  /* root points to the root block. */
+  ngtcp2_ksl_blk *root;
   /* front points to the first leaf block. */
   ngtcp2_ksl_blk *front;
   /* back points to the last leaf block. */
@@ -275,11 +277,11 @@ size_t ngtcp2_ksl_len(const ngtcp2_ksl *ksl);
 void ngtcp2_ksl_clear(ngtcp2_ksl *ksl);
 
 /*
- * ngtcp2_ksl_nth_key returns the |n|th key under |blk|.
+ * ngtcp2_ksl_blk_nth_key returns the |n|th key under |blk|.
  */
 static inline const ngtcp2_ksl_key *
-ngtcp2_ksl_nth_key(const ngtcp2_ksl *ksl, const ngtcp2_ksl_blk *blk, size_t n) {
-  return blk->keys + n * ksl->aligned_keylen;
+ngtcp2_ksl_blk_nth_key(const ngtcp2_ksl_blk *blk, size_t n) {
+  return blk->keys + n * blk->aligned_keylen;
 }
 
 #ifndef WIN32
@@ -294,8 +296,7 @@ void ngtcp2_ksl_print(const ngtcp2_ksl *ksl);
 /*
  * ngtcp2_ksl_it_init initializes |it|.
  */
-void ngtcp2_ksl_it_init(ngtcp2_ksl_it *it, const ngtcp2_ksl *ksl,
-                        ngtcp2_ksl_blk *blk, size_t i);
+void ngtcp2_ksl_it_init(ngtcp2_ksl_it *it, ngtcp2_ksl_blk *blk, size_t i);
 
 /*
  * ngtcp2_ksl_it_get returns the data associated to the node which
@@ -346,7 +347,7 @@ int ngtcp2_ksl_it_begin(const ngtcp2_ksl_it *it);
  * returns nonzero.
  */
 static inline const ngtcp2_ksl_key *ngtcp2_ksl_it_key(const ngtcp2_ksl_it *it) {
-  return ngtcp2_ksl_nth_key(it->ksl, it->blk, it->i);
+  return ngtcp2_ksl_blk_nth_key(it->blk, it->i);
 }
 
 /*
diff --git a/deps/ngtcp2/ngtcp2/lib/ngtcp2_macro.h b/deps/ngtcp2/ngtcp2/lib/ngtcp2_macro.h
index dfe5e0aed220f8..12cba12719ac7b 100644
--- a/deps/ngtcp2/ngtcp2/lib/ngtcp2_macro.h
+++ b/deps/ngtcp2/ngtcp2/lib/ngtcp2_macro.h
@@ -52,6 +52,13 @@
  */
 #define ngtcp2_arraylen(A) (sizeof(A) / sizeof(A[0]))
 
+/*
+ * ngtcp2_strlen_lit returns the length of string literal |S|.  This
+ * macro assumes |S| is NULL-terminated string literal.  It must not
+ * be used with pointers.
+ */
+#define ngtcp2_strlen_lit(S) (sizeof(S) - 1)
+
 #define ngtcp2_max_def(SUFFIX, T)                                              \
   static inline T ngtcp2_max_##SUFFIX(T a, T b) { return a < b ? b : a; }
 
diff --git a/deps/ngtcp2/ngtcp2/lib/ngtcp2_pkt.c b/deps/ngtcp2/ngtcp2/lib/ngtcp2_pkt.c
index 9c0e2636bcc051..0179dbcde96445 100644
--- a/deps/ngtcp2/ngtcp2/lib/ngtcp2_pkt.c
+++ b/deps/ngtcp2/ngtcp2/lib/ngtcp2_pkt.c
@@ -2308,11 +2308,11 @@ ngtcp2_ssize ngtcp2_pkt_write_retry(
   case NGTCP2_PROTO_VER_V1:
   default:
     nonce = (const uint8_t *)NGTCP2_RETRY_NONCE_V1;
-    noncelen = sizeof(NGTCP2_RETRY_NONCE_V1) - 1;
+    noncelen = ngtcp2_strlen_lit(NGTCP2_RETRY_NONCE_V1);
     break;
   case NGTCP2_PROTO_VER_V2:
     nonce = (const uint8_t *)NGTCP2_RETRY_NONCE_V2;
-    noncelen = sizeof(NGTCP2_RETRY_NONCE_V2) - 1;
+    noncelen = ngtcp2_strlen_lit(NGTCP2_RETRY_NONCE_V2);
     break;
   }
 
@@ -2398,11 +2398,11 @@ int ngtcp2_pkt_verify_retry_tag(uint32_t version, const ngtcp2_pkt_retry *retry,
   case NGTCP2_PROTO_VER_V1:
   default:
     nonce = (const uint8_t *)NGTCP2_RETRY_NONCE_V1;
-    noncelen = sizeof(NGTCP2_RETRY_NONCE_V1) - 1;
+    noncelen = ngtcp2_strlen_lit(NGTCP2_RETRY_NONCE_V1);
     break;
   case NGTCP2_PROTO_VER_V2:
     nonce = (const uint8_t *)NGTCP2_RETRY_NONCE_V2;
-    noncelen = sizeof(NGTCP2_RETRY_NONCE_V2) - 1;
+    noncelen = ngtcp2_strlen_lit(NGTCP2_RETRY_NONCE_V2);
     break;
   }
 
diff --git a/deps/ngtcp2/ngtcp2/lib/ngtcp2_pv.h b/deps/ngtcp2/ngtcp2/lib/ngtcp2_pv.h
index 2d07e41648db2e..b62ab204b216a5 100644
--- a/deps/ngtcp2/ngtcp2/lib/ngtcp2_pv.h
+++ b/deps/ngtcp2/ngtcp2/lib/ngtcp2_pv.h
@@ -57,7 +57,7 @@ typedef struct ngtcp2_pv_entry {
   /* flags is zero or more of NGTCP2_PV_ENTRY_FLAG_*. */
   uint8_t flags;
   /* data is a byte string included in PATH_CHALLENGE. */
-  uint8_t data[8];
+  uint8_t data[NGTCP2_PATH_CHALLENGE_DATALEN];
 } ngtcp2_pv_entry;
 
 void ngtcp2_pv_entry_init(ngtcp2_pv_entry *pvent, const uint8_t *data,
diff --git a/deps/ngtcp2/ngtcp2/lib/ngtcp2_qlog.c b/deps/ngtcp2/ngtcp2/lib/ngtcp2_qlog.c
index f0c67acdd51b37..7c1142d14d3c6a 100644
--- a/deps/ngtcp2/ngtcp2/lib/ngtcp2_qlog.c
+++ b/deps/ngtcp2/ngtcp2/lib/ngtcp2_qlog.c
@@ -40,7 +40,7 @@ void ngtcp2_qlog_init(ngtcp2_qlog *qlog, ngtcp2_qlog_write write,
   qlog->user_data = user_data;
 }
 
-#define write_verbatim(DEST, S) ngtcp2_cpymem((DEST), (S), sizeof(S) - 1)
+#define write_verbatim(DEST, S) ngtcp2_cpymem((DEST), (S), ngtcp2_strlen_lit(S))
 
 static uint8_t *write_string_impl(uint8_t *p, const uint8_t *data,
                                   size_t datalen) {
@@ -53,7 +53,7 @@ static uint8_t *write_string_impl(uint8_t *p, const uint8_t *data,
 }
 
 #define write_string(DEST, S)                                                  \
-  write_string_impl((DEST), (const uint8_t *)(S), sizeof(S) - 1)
+  write_string_impl((DEST), (const uint8_t *)(S), ngtcp2_strlen_lit(S))
 
 static uint8_t *write_hex(uint8_t *p, const uint8_t *data, size_t datalen) {
   *p++ = '"';
@@ -76,9 +76,9 @@ static uint8_t *write_duration(uint8_t *p, ngtcp2_duration duration) {
 
 static uint8_t *write_bool(uint8_t *p, int b) {
   if (b) {
-    return ngtcp2_cpymem(p, "true", sizeof("true") - 1);
+    return ngtcp2_cpymem(p, "true", ngtcp2_strlen_lit("true"));
   }
-  return ngtcp2_cpymem(p, "false", sizeof("false") - 1);
+  return ngtcp2_cpymem(p, "false", ngtcp2_strlen_lit("false"));
 }
 
 static uint8_t *write_pair_impl(uint8_t *p, const uint8_t *name, size_t namelen,
@@ -89,7 +89,8 @@ static uint8_t *write_pair_impl(uint8_t *p, const uint8_t *name, size_t namelen,
 }
 
 #define write_pair(DEST, NAME, VALUE)                                          \
-  write_pair_impl((DEST), (const uint8_t *)(NAME), sizeof(NAME) - 1, (VALUE))
+  write_pair_impl((DEST), (const uint8_t *)(NAME), ngtcp2_strlen_lit(NAME),    \
+                  (VALUE))
 
 static uint8_t *write_pair_hex_impl(uint8_t *p, const uint8_t *name,
                                     size_t namelen, const uint8_t *value,
@@ -100,8 +101,8 @@ static uint8_t *write_pair_hex_impl(uint8_t *p, const uint8_t *name,
 }
 
 #define write_pair_hex(DEST, NAME, VALUE, VALUELEN)                            \
-  write_pair_hex_impl((DEST), (const uint8_t *)(NAME), sizeof(NAME) - 1,       \
-                      (VALUE), (VALUELEN))
+  write_pair_hex_impl((DEST), (const uint8_t *)(NAME),                         \
+                      ngtcp2_strlen_lit(NAME), (VALUE), (VALUELEN))
 
 static uint8_t *write_pair_number_impl(uint8_t *p, const uint8_t *name,
                                        size_t namelen, uint64_t value) {
@@ -111,8 +112,8 @@ static uint8_t *write_pair_number_impl(uint8_t *p, const uint8_t *name,
 }
 
 #define write_pair_number(DEST, NAME, VALUE)                                   \
-  write_pair_number_impl((DEST), (const uint8_t *)(NAME), sizeof(NAME) - 1,    \
-                         (VALUE))
+  write_pair_number_impl((DEST), (const uint8_t *)(NAME),                      \
+                         ngtcp2_strlen_lit(NAME), (VALUE))
 
 static uint8_t *write_pair_duration_impl(uint8_t *p, const uint8_t *name,
                                          size_t namelen,
@@ -123,8 +124,8 @@ static uint8_t *write_pair_duration_impl(uint8_t *p, const uint8_t *name,
 }
 
 #define write_pair_duration(DEST, NAME, VALUE)                                 \
-  write_pair_duration_impl((DEST), (const uint8_t *)(NAME), sizeof(NAME) - 1,  \
-                           (VALUE))
+  write_pair_duration_impl((DEST), (const uint8_t *)(NAME),                    \
+                           ngtcp2_strlen_lit(NAME), (VALUE))
 
 static uint8_t *write_pair_tstamp_impl(uint8_t *p, const uint8_t *name,
                                        size_t namelen, ngtcp2_tstamp ts) {
@@ -134,8 +135,8 @@ static uint8_t *write_pair_tstamp_impl(uint8_t *p, const uint8_t *name,
 }
 
 #define write_pair_tstamp(DEST, NAME, VALUE)                                   \
-  write_pair_tstamp_impl((DEST), (const uint8_t *)(NAME), sizeof(NAME) - 1,    \
-                         (VALUE))
+  write_pair_tstamp_impl((DEST), (const uint8_t *)(NAME),                      \
+                         ngtcp2_strlen_lit(NAME), (VALUE))
 
 static uint8_t *write_pair_bool_impl(uint8_t *p, const uint8_t *name,
                                      size_t namelen, int b) {
@@ -145,8 +146,8 @@ static uint8_t *write_pair_bool_impl(uint8_t *p, const uint8_t *name,
 }
 
 #define write_pair_bool(DEST, NAME, VALUE)                                     \
-  write_pair_bool_impl((DEST), (const uint8_t *)(NAME), sizeof(NAME) - 1,      \
-                       (VALUE))
+  write_pair_bool_impl((DEST), (const uint8_t *)(NAME),                        \
+                       ngtcp2_strlen_lit(NAME), (VALUE))
 
 static uint8_t *write_pair_cid_impl(uint8_t *p, const uint8_t *name,
                                     size_t namelen, const ngtcp2_cid *cid) {
@@ -156,10 +157,10 @@ static uint8_t *write_pair_cid_impl(uint8_t *p, const uint8_t *name,
 }
 
 #define write_pair_cid(DEST, NAME, VALUE)                                      \
-  write_pair_cid_impl((DEST), (const uint8_t *)(NAME), sizeof(NAME) - 1,       \
-                      (VALUE))
+  write_pair_cid_impl((DEST), (const uint8_t *)(NAME),                         \
+                      ngtcp2_strlen_lit(NAME), (VALUE))
 
-#define ngtcp2_make_vec_lit(S) {(uint8_t *)(S), sizeof((S)) - 1}
+#define ngtcp2_make_vec_lit(S) {(uint8_t *)(S), ngtcp2_strlen_lit((S))}
 
 static uint8_t *write_common_fields(uint8_t *p, const ngtcp2_cid *odcid) {
   p = write_verbatim(
@@ -1173,8 +1174,8 @@ void ngtcp2_qlog_version_negotiation_pkt_received(ngtcp2_qlog *qlog,
   buf.last = write_verbatim(buf.last, ",\"supported_versions\":[");
 
   if (nsv) {
-    if (ngtcp2_buf_left(&buf) <
-        (sizeof("\"xxxxxxxx\",") - 1) * nsv - 1 + sizeof("]}}\n") - 1) {
+    if (ngtcp2_buf_left(&buf) < ngtcp2_strlen_lit("\"xxxxxxxx\",") * nsv - 1 +
+                                  ngtcp2_strlen_lit("]}}\n")) {
       return;
     }
 
diff --git a/deps/ngtcp2/ngtcp2/lib/ngtcp2_settings.h b/deps/ngtcp2/ngtcp2/lib/ngtcp2_settings.h
index 28b91d8d36ff72..b40b6c4a89525b 100644
--- a/deps/ngtcp2/ngtcp2/lib/ngtcp2_settings.h
+++ b/deps/ngtcp2/ngtcp2/lib/ngtcp2_settings.h
@@ -33,10 +33,10 @@
 
 /* NGTCP2_DEFAULT_GLITCH_RATELIM_BURST is the maximum number of tokens
    in glitch rate limiter.  It is also the initial value. */
-#define NGTCP2_DEFAULT_GLITCH_RATELIM_BURST 4000
+#define NGTCP2_DEFAULT_GLITCH_RATELIM_BURST 10000
 /* NGTCP2_DEFAULT_GLITCH_RATELIM_RATE is the rate of tokens generated
    per second for glitch rate limiter. */
-#define NGTCP2_DEFAULT_GLITCH_RATELIM_RATE 132
+#define NGTCP2_DEFAULT_GLITCH_RATELIM_RATE 330
 
 /*
  * ngtcp2_settings_convert_to_latest converts |src| of version
diff --git a/deps/ngtcp2/ngtcp2/lib/ngtcp2_strm.c b/deps/ngtcp2/ngtcp2/lib/ngtcp2_strm.c
index 99d02da1b8855f..70aa8933a3b83f 100644
--- a/deps/ngtcp2/ngtcp2/lib/ngtcp2_strm.c
+++ b/deps/ngtcp2/ngtcp2/lib/ngtcp2_strm.c
@@ -199,7 +199,7 @@ int ngtcp2_strm_streamfrq_push(ngtcp2_strm *strm, ngtcp2_frame_chain *frc) {
     if (rv != 0) {
       return rv;
     }
-  } else if (ngtcp2_ksl_len(strm->tx.streamfrq) >= 1000) {
+  } else if (ngtcp2_ksl_len(strm->tx.streamfrq) >= 8000) {
     return NGTCP2_ERR_INTERNAL;
   }
 
@@ -372,13 +372,12 @@ static int strm_streamfrq_unacked_pop(ngtcp2_strm *strm,
 int ngtcp2_strm_streamfrq_pop(ngtcp2_strm *strm, ngtcp2_frame_chain **pfrc,
                               size_t left) {
   ngtcp2_stream *fr, *nfr;
-  ngtcp2_frame_chain *frc, *nfrc, *sfrc;
+  ngtcp2_frame_chain *frc, *nfrc;
   int rv;
   size_t nmerged;
   uint64_t datalen;
-  ngtcp2_vec a[NGTCP2_MAX_STREAM_DATACNT];
-  ngtcp2_vec b[NGTCP2_MAX_STREAM_DATACNT];
-  size_t acnt, bcnt;
+  ngtcp2_vec data[NGTCP2_MAX_STREAM_DATACNT];
+  size_t datacnt;
   uint64_t unacked_offset;
 
   if (strm->tx.streamfrq == NULL || ngtcp2_ksl_len(strm->tx.streamfrq) == 0) {
@@ -418,17 +417,15 @@ int ngtcp2_strm_streamfrq_pop(ngtcp2_strm *strm, ngtcp2_frame_chain **pfrc,
   }
 
   if (datalen > left) {
-    ngtcp2_vec_copy(a, fr->data, fr->datacnt);
-    acnt = fr->datacnt;
-
-    bcnt = 0;
-    ngtcp2_vec_split(b, &bcnt, a, &acnt, left, NGTCP2_MAX_STREAM_DATACNT);
+    datacnt = 0;
+    ngtcp2_vec_split(data, &datacnt, fr->data, &fr->datacnt, left,
+                     NGTCP2_MAX_STREAM_DATACNT);
 
-    assert(acnt > 0);
-    assert(bcnt > 0);
+    assert(fr->datacnt > 0);
+    assert(datacnt > 0);
 
     rv = ngtcp2_frame_chain_stream_datacnt_objalloc_new(
-      &nfrc, bcnt, strm->frc_objalloc, strm->mem);
+      &nfrc, datacnt, strm->frc_objalloc, strm->mem);
     if (rv != 0) {
       assert(ngtcp2_err_is_fatal(rv));
       ngtcp2_frame_chain_objalloc_del(frc, strm->frc_objalloc, strm->mem);
@@ -441,8 +438,8 @@ int ngtcp2_strm_streamfrq_pop(ngtcp2_strm *strm, ngtcp2_frame_chain **pfrc,
     nfr->fin = fr->fin;
     nfr->stream_id = fr->stream_id;
     nfr->offset = fr->offset + left;
-    nfr->datacnt = bcnt;
-    ngtcp2_vec_copy(nfr->data, b, bcnt);
+    nfr->datacnt = datacnt;
+    ngtcp2_vec_copy(nfr->data, data, datacnt);
 
     rv = ngtcp2_ksl_insert(strm->tx.streamfrq, NULL, &nfr->offset, nfrc);
     if (rv != 0) {
@@ -453,34 +450,17 @@ int ngtcp2_strm_streamfrq_pop(ngtcp2_strm *strm, ngtcp2_frame_chain **pfrc,
       return rv;
     }
 
-    rv = ngtcp2_frame_chain_stream_datacnt_objalloc_new(
-      &nfrc, acnt, strm->frc_objalloc, strm->mem);
-    if (rv != 0) {
-      assert(ngtcp2_err_is_fatal(rv));
-      ngtcp2_frame_chain_objalloc_del(frc, strm->frc_objalloc, strm->mem);
-      return rv;
-    }
-
-    nfr = &nfrc->fr.stream;
-    nfr->type = fr->type;
-    nfr->flags = fr->flags;
-    nfr->fin = 0;
-    nfr->stream_id = fr->stream_id;
-    nfr->offset = fr->offset;
-    nfr->datacnt = acnt;
-    ngtcp2_vec_copy(nfr->data, a, acnt);
-
-    ngtcp2_frame_chain_objalloc_del(frc, strm->frc_objalloc, strm->mem);
+    fr->fin = 0;
 
-    *pfrc = nfrc;
+    *pfrc = frc;
 
     return 0;
   }
 
   left -= (size_t)datalen;
 
-  ngtcp2_vec_copy(a, fr->data, fr->datacnt);
-  acnt = fr->datacnt;
+  ngtcp2_vec_copy(data, fr->data, fr->datacnt);
+  datacnt = fr->datacnt;
 
   for (; left && ngtcp2_ksl_len(strm->tx.streamfrq);) {
     unacked_offset = ngtcp2_strm_streamfrq_unacked_offset(strm);
@@ -507,9 +487,7 @@ int ngtcp2_strm_streamfrq_pop(ngtcp2_strm *strm, ngtcp2_frame_chain **pfrc,
       break;
     }
 
-    bcnt = nfr->datacnt;
-
-    nmerged = ngtcp2_vec_merge(a, &acnt, nfr->data, &bcnt, left,
+    nmerged = ngtcp2_vec_merge(data, &datacnt, nfr->data, &nfr->datacnt, left,
                                NGTCP2_MAX_STREAM_DATACNT);
     if (nmerged == 0) {
       rv = ngtcp2_ksl_insert(strm->tx.streamfrq, NULL, &nfr->offset, nfrc);
@@ -527,54 +505,27 @@ int ngtcp2_strm_streamfrq_pop(ngtcp2_strm *strm, ngtcp2_frame_chain **pfrc,
     datalen += nmerged;
     left -= nmerged;
 
-    if (bcnt == 0) {
+    if (nfr->datacnt == 0) {
       fr->fin = nfr->fin;
       ngtcp2_frame_chain_objalloc_del(nfrc, strm->frc_objalloc, strm->mem);
       continue;
     }
 
-    if (nfr->datacnt <= NGTCP2_FRAME_CHAIN_STREAM_DATACNT_THRES ||
-        bcnt > NGTCP2_FRAME_CHAIN_STREAM_DATACNT_THRES) {
-      nfr->offset += nmerged;
-      nfr->datacnt = bcnt;
-
-      rv = ngtcp2_ksl_insert(strm->tx.streamfrq, NULL, &nfr->offset, nfrc);
-      if (rv != 0) {
-        ngtcp2_frame_chain_objalloc_del(nfrc, strm->frc_objalloc, strm->mem);
-        ngtcp2_frame_chain_objalloc_del(frc, strm->frc_objalloc, strm->mem);
-        return rv;
-      }
-    } else {
-      rv = ngtcp2_frame_chain_stream_datacnt_objalloc_new(
-        &sfrc, bcnt, strm->frc_objalloc, strm->mem);
-      if (rv != 0) {
-        ngtcp2_frame_chain_objalloc_del(nfrc, strm->frc_objalloc, strm->mem);
-        ngtcp2_frame_chain_objalloc_del(frc, strm->frc_objalloc, strm->mem);
-        return rv;
-      }
-
-      sfrc->fr.stream = nfrc->fr.stream;
-      sfrc->fr.stream.offset += nmerged;
-      sfrc->fr.stream.datacnt = bcnt;
-      ngtcp2_vec_copy(sfrc->fr.stream.data, nfrc->fr.stream.data, bcnt);
+    nfr->offset += nmerged;
 
+    rv = ngtcp2_ksl_insert(strm->tx.streamfrq, NULL, &nfr->offset, nfrc);
+    if (rv != 0) {
       ngtcp2_frame_chain_objalloc_del(nfrc, strm->frc_objalloc, strm->mem);
-
-      rv = ngtcp2_ksl_insert(strm->tx.streamfrq, NULL, &sfrc->fr.stream.offset,
-                             sfrc);
-      if (rv != 0) {
-        ngtcp2_frame_chain_objalloc_del(sfrc, strm->frc_objalloc, strm->mem);
-        ngtcp2_frame_chain_objalloc_del(frc, strm->frc_objalloc, strm->mem);
-        return rv;
-      }
+      ngtcp2_frame_chain_objalloc_del(frc, strm->frc_objalloc, strm->mem);
+      return rv;
     }
 
     break;
   }
 
-  if (acnt == fr->datacnt) {
-    if (acnt > 0) {
-      fr->data[acnt - 1] = a[acnt - 1];
+  if (datacnt == fr->datacnt) {
+    if (datacnt > 0) {
+      fr->data[datacnt - 1] = data[datacnt - 1];
     }
 
     *pfrc = frc;
@@ -582,10 +533,10 @@ int ngtcp2_strm_streamfrq_pop(ngtcp2_strm *strm, ngtcp2_frame_chain **pfrc,
     return 0;
   }
 
-  assert(acnt > fr->datacnt);
+  assert(datacnt > fr->datacnt);
 
   rv = ngtcp2_frame_chain_stream_datacnt_objalloc_new(
-    &nfrc, acnt, strm->frc_objalloc, strm->mem);
+    &nfrc, datacnt, strm->frc_objalloc, strm->mem);
   if (rv != 0) {
     ngtcp2_frame_chain_objalloc_del(frc, strm->frc_objalloc, strm->mem);
     return rv;
@@ -597,8 +548,8 @@ int ngtcp2_strm_streamfrq_pop(ngtcp2_strm *strm, ngtcp2_frame_chain **pfrc,
   nfr->fin = fr->fin;
   nfr->stream_id = fr->stream_id;
   nfr->offset = fr->offset;
-  nfr->datacnt = acnt;
-  ngtcp2_vec_copy(nfr->data, a, acnt);
+  nfr->datacnt = datacnt;
+  ngtcp2_vec_copy(nfr->data, data, datacnt);
 
   ngtcp2_frame_chain_objalloc_del(frc, strm->frc_objalloc, strm->mem);
 
diff --git a/deps/ngtcp2/ngtcp2/lib/ngtcp2_strm.h b/deps/ngtcp2/ngtcp2/lib/ngtcp2_strm.h
index 1a1e8fd3b7d5c4..fb86bd1c23d6e5 100644
--- a/deps/ngtcp2/ngtcp2/lib/ngtcp2_strm.h
+++ b/deps/ngtcp2/ngtcp2/lib/ngtcp2_strm.h
@@ -171,14 +171,14 @@ struct ngtcp2_strm {
       const ngtcp2_mem *mem;
       int64_t stream_id;
       void *stream_user_data;
-      /* flags is bit-wise OR of zero or more of NGTCP2_STRM_FLAG_*. */
-      uint32_t flags;
       /* app_error_code is an error code the local endpoint sent in
          RESET_STREAM or STOP_SENDING, or received from a remote endpoint
          in RESET_STREAM or STOP_SENDING.  First application error code is
          chosen and when set, NGTCP2_STRM_FLAG_APP_ERROR_CODE_SET flag is
          set in flags field. */
       uint64_t app_error_code;
+      /* flags is bit-wise OR of zero or more of NGTCP2_STRM_FLAG_*. */
+      uint32_t flags;
     };
 
     ngtcp2_opl_entry oplent;