From 72b4af6143681f528f1d237b21a9a7aee1738832 Mon Sep 17 00:00:00 2001
From: Tatsuhiro Tsujikawa <tatsuhiro.t@gmail.com>
Date: Sun, 1 Oct 2023 00:05:01 +0900
Subject: [PATCH] Rework session management

Conflict:remove .github/workflows/build.yml
Reference:https://github.com/nghttp2/nghttp2/commit/72b4af6143681f528f1d237b21a9a7aee1738832

---
 CMakeLists.txt                 |   4 ++
 cmakeconfig.h.in               |   9 +++
 configure.ac                   |  21 +++++++
 doc/Makefile.am                |   1 +
 lib/CMakeLists.txt             |   2 +
 lib/Makefile.am                |   4 ++
 lib/includes/nghttp2/nghttp2.h |  17 ++++++
 lib/nghttp2_option.c           |   7 +++
 lib/nghttp2_option.h           |   6 ++
 lib/nghttp2_ratelim.c          |  75 ++++++++++++++++++++++++
 lib/nghttp2_ratelim.h          |  57 ++++++++++++++++++
 lib/nghttp2_session.c          |  34 ++++++++++-
 lib/nghttp2_session.h          |  12 +++-
 lib/nghttp2_time.c             |  62 ++++++++++++++++++++
 lib/nghttp2_time.h             |  38 ++++++++++++
 tests/CMakeLists.txt           |   1 +
 tests/Makefile.am              |   6 +-
 tests/main.c                   |   7 ++-
 tests/nghttp2_ratelim_test.c   | 101 ++++++++++++++++++++++++++++++++
 tests/nghttp2_ratelim_test.h   |  35 +++++++++++
 tests/nghttp2_session_test.c   | 103 +++++++++++++++++++++++++++++++++
 tests/nghttp2_session_test.h   |   1 +
 22 files changed, 598 insertions(+), 5 deletions(-)
 create mode 100644 lib/nghttp2_ratelim.c
 create mode 100644 lib/nghttp2_ratelim.h
 create mode 100644 lib/nghttp2_time.c
 create mode 100644 lib/nghttp2_time.h
 create mode 100644 tests/nghttp2_ratelim_test.c
 create mode 100644 tests/nghttp2_ratelim_test.h

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 69c2c7b..b04d512 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -264,6 +264,7 @@ check_include_file("netinet/in.h"   HAVE_NETINET_IN_H)
 check_include_file("pwd.h"          HAVE_PWD_H)
 check_include_file("sys/socket.h"   HAVE_SYS_SOCKET_H)
 check_include_file("sys/time.h"     HAVE_SYS_TIME_H)
+check_include_file("sysinfoapi.h"   HAVE_SYSINFOAPI_H)
 check_include_file("syslog.h"       HAVE_SYSLOG_H)
 check_include_file("time.h"         HAVE_TIME_H)
 check_include_file("unistd.h"       HAVE_UNISTD_H)
@@ -304,8 +305,11 @@ check_type_size("time_t"  SIZEOF_TIME_T)
 include(CheckFunctionExists)
 check_function_exists(_Exit     HAVE__EXIT)
 check_function_exists(accept4   HAVE_ACCEPT4)
+check_function_exists(clock_gettime HAVE_CLOCK_GETTIME)
 check_function_exists(mkostemp  HAVE_MKOSTEMP)
 
+check_symbol_exists(GetTickCount64 sysinfoapi.h HAVE_GETTICKCOUNT64)
+
 include(CheckSymbolExists)
 # XXX does this correctly detect initgroups (un)availability on cygwin?
 check_symbol_exists(initgroups grp.h HAVE_DECL_INITGROUPS)
diff --git a/cmakeconfig.h.in b/cmakeconfig.h.in
index d67b540..4065029 100644
--- a/cmakeconfig.h.in
+++ b/cmakeconfig.h.in
@@ -34,9 +34,15 @@
 /* Define to 1 if you have the `accept4` function. */
 #cmakedefine HAVE_ACCEPT4 1
 
+/* Define to 1 if you have the `clock_gettime` function. */
+#cmakedefine HAVE_CLOCK_GETTIME 1
+
 /* Define to 1 if you have the `mkostemp` function. */
 #cmakedefine HAVE_MKOSTEMP 1
 
+/* Define to 1 if you have the `GetTickCount64` function. */
+#cmakedefine HAVE_GETTICKCOUNT64 1
+
 /* Define to 1 if you have the `initgroups` function. */
 #cmakedefine01 HAVE_DECL_INITGROUPS
 
@@ -73,6 +79,9 @@
 /* Define to 1 if you have the <sys/time.h> header file. */
 #cmakedefine HAVE_SYS_TIME_H 1
 
+/* Define to 1 if you have the <sysinfoapi.h> header file. */
+#cmakedefine HAVE_SYSINFOAPI_H 1
+
 /* Define to 1 if you have the <syslog.h> header file. */
 #cmakedefine HAVE_SYSLOG_H 1
 
diff --git a/configure.ac b/configure.ac
index 961b78d..db9ec7c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -607,6 +607,7 @@ AC_CHECK_HEADERS([ \
   string.h \
   sys/socket.h \
   sys/time.h \
+  sysinfoapi.h \
   syslog.h \
   time.h \
   unistd.h \
@@ -681,6 +682,7 @@ AC_FUNC_STRNLEN
 AC_CHECK_FUNCS([ \
   _Exit \
   accept4 \
+  clock_gettime \
   dup2 \
   getcwd \
   getpwnam \
@@ -706,6 +708,25 @@ AC_CHECK_FUNCS([ \
 AC_CHECK_FUNC([timerfd_create],
               [have_timerfd_create=yes], [have_timerfd_create=no])
 
+AC_MSG_CHECKING([checking for GetTickCount64])
+AC_LINK_IFELSE([AC_LANG_PROGRAM(
+[[
+#include <sysinfoapi.h>
+]],
+[[
+GetTickCount64();
+]])],
+[have_gettickcount64=yes],
+[have_gettickcount64=no])
+
+if test "x${have_gettickcount64}" = "xyes"; then
+  AC_MSG_RESULT([yes])
+  AC_DEFINE([HAVE_GETTICKCOUNT64], [1],
+            [Define to 1 if you have `GetTickCount64` function.])
+else
+  AC_MSG_RESULT([no])
+fi
+
 # For cygwin: we can link initgroups, so AC_CHECK_FUNCS succeeds, but
 # cygwin disables initgroups due to feature test macro magic with our
 # configuration.  FreeBSD declares initgroups() in unistd.h.
diff --git a/doc/Makefile.am b/doc/Makefile.am
index f073bfa..40a0011 100644
--- a/doc/Makefile.am
+++ b/doc/Makefile.am
@@ -70,6 +70,7 @@ APIDOCS= \
 	nghttp2_option_set_user_recv_extension_type.rst \
 	nghttp2_option_set_max_outbound_ack.rst \
 	nghttp2_option_set_max_settings.rst \
+	nghttp2_option_set_stream_reset_rate_limit.rst \
 	nghttp2_pack_settings_payload.rst \
 	nghttp2_priority_spec_check_default.rst \
 	nghttp2_priority_spec_default_init.rst \
diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
index 4dc2fcd..26e843d 100644
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@@ -23,6 +23,8 @@ set(NGHTTP2_SOURCES
   nghttp2_mem.c
   nghttp2_http.c
   nghttp2_rcbuf.c
+  nghttp2_ratelim.c
+  nghttp2_time.c
   nghttp2_debug.c
 )
 
diff --git a/lib/Makefile.am b/lib/Makefile.am
index 24a5bd6..595714d 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -49,6 +49,8 @@ OBJECTS = nghttp2_pq.c nghttp2_map.c nghttp2_queue.c \
 	nghttp2_mem.c \
 	nghttp2_http.c \
 	nghttp2_rcbuf.c \
+	nghttp2_ratelim.c \
+	nghttp2_time.c \
 	nghttp2_debug.c
 
 HFILES = nghttp2_pq.h nghttp2_int.h nghttp2_map.h nghttp2_queue.h \
@@ -65,6 +67,8 @@ HFILES = nghttp2_pq.h nghttp2_int.h nghttp2_map.h nghttp2_queue.h \
 	nghttp2_mem.h \
 	nghttp2_http.h \
 	nghttp2_rcbuf.h \
+	nghttp2_ratelim.h \
+	nghttp2_time.h \
 	nghttp2_debug.h
 
 libnghttp2_la_SOURCES = $(HFILES) $(OBJECTS)
diff --git a/lib/includes/nghttp2/nghttp2.h b/lib/includes/nghttp2/nghttp2.h
index 9be6eea..f0b9f17 100644
--- a/lib/includes/nghttp2/nghttp2.h
+++ b/lib/includes/nghttp2/nghttp2.h
@@ -2760,6 +2760,23 @@ nghttp2_session_client_new2(nghttp2_session **session_ptr,
                             const nghttp2_session_callbacks *callbacks,
                             void *user_data, const nghttp2_option *option);
 
+/**
+ * @function
+ *
+ * This function sets the rate limit for the incoming stream reset
+ * (RST_STREAM frame).  It is server use only.  It is a token-bucket
+ * based rate limiter.  |burst| specifies the number of tokens that is
+ * initially available.  The maximum number of tokens is capped to
+ * this value.  |rate| specifies the number of tokens that are
+ * regenerated per second.  An incoming RST_STREAM consumes one token.
+ * If there is no token available, GOAWAY is sent to tear down the
+ * connection.  |burst| and |rate| default to 1000 and 33
+ * respectively.
+ */
+NGHTTP2_EXTERN void
+nghttp2_option_set_stream_reset_rate_limit(nghttp2_option *option,
+                                           uint64_t burst, uint64_t rate);
+
 /**
  * @function
  *
diff --git a/lib/nghttp2_option.c b/lib/nghttp2_option.c
index 34348e6..0d9a404 100644
--- a/lib/nghttp2_option.c
+++ b/lib/nghttp2_option.c
@@ -126,3 +126,10 @@ void nghttp2_option_set_max_settings(nghttp2_option *option, size_t val) {
   option->opt_set_mask |= NGHTTP2_OPT_MAX_SETTINGS;
   option->max_settings = val;
 }
+
+void nghttp2_option_set_stream_reset_rate_limit(nghttp2_option *option,
+                                                uint64_t burst, uint64_t rate) {
+  option->opt_set_mask |= NGHTTP2_OPT_STREAM_RESET_RATE_LIMIT;
+  option->stream_reset_burst = burst;
+  option->stream_reset_rate = rate;
+}
diff --git a/lib/nghttp2_option.h b/lib/nghttp2_option.h
index 939729f..e6ba910 100644
--- a/lib/nghttp2_option.h
+++ b/lib/nghttp2_option.h
@@ -68,12 +68,18 @@ typedef enum {
   NGHTTP2_OPT_NO_CLOSED_STREAMS = 1 << 10,
   NGHTTP2_OPT_MAX_OUTBOUND_ACK = 1 << 11,
   NGHTTP2_OPT_MAX_SETTINGS = 1 << 12,
+  NGHTTP2_OPT_STREAM_RESET_RATE_LIMIT = 1 << 15,
 } nghttp2_option_flag;
 
 /**
  * Struct to store option values for nghttp2_session.
  */
 struct nghttp2_option {
+  /**
+   * NGHTTP2_OPT_STREAM_RESET_RATE_LIMIT
+   */
+  uint64_t stream_reset_burst;
+  uint64_t stream_reset_rate;
   /**
    * NGHTTP2_OPT_MAX_SEND_HEADER_BLOCK_LENGTH
    */
diff --git a/lib/nghttp2_ratelim.c b/lib/nghttp2_ratelim.c
new file mode 100644
index 0000000..7011655
--- /dev/null
+++ b/lib/nghttp2_ratelim.c
@@ -0,0 +1,75 @@
+/*
+ * nghttp2 - HTTP/2 C Library
+ *
+ * Copyright (c) 2023 nghttp2 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 "nghttp2_ratelim.h"
+#include "nghttp2_helper.h"
+
+void nghttp2_ratelim_init(nghttp2_ratelim *rl, uint64_t burst, uint64_t rate) {
+  rl->val = rl->burst = burst;
+  rl->rate = rate;
+  rl->tstamp = 0;
+}
+
+void nghttp2_ratelim_update(nghttp2_ratelim *rl, uint64_t tstamp) {
+  uint64_t d, gain;
+
+  if (tstamp == rl->tstamp) {
+    return;
+  }
+
+  if (tstamp > rl->tstamp) {
+    d = tstamp - rl->tstamp;
+  } else {
+    d = 1;
+  }
+
+  rl->tstamp = tstamp;
+
+  if (UINT64_MAX / d < rl->rate) {
+    rl->val = rl->burst;
+
+    return;
+  }
+
+  gain = rl->rate * d;
+
+  if (UINT64_MAX - gain < rl->val) {
+    rl->val = rl->burst;
+
+    return;
+  }
+
+  rl->val += gain;
+  rl->val = nghttp2_min(rl->val, rl->burst);
+}
+
+int nghttp2_ratelim_drain(nghttp2_ratelim *rl, uint64_t n) {
+  if (rl->val < n) {
+    return -1;
+  }
+
+  rl->val -= n;
+
+  return 0;
+}
diff --git a/lib/nghttp2_ratelim.h b/lib/nghttp2_ratelim.h
new file mode 100644
index 0000000..866ed3f
--- /dev/null
+++ b/lib/nghttp2_ratelim.h
@@ -0,0 +1,57 @@
+/*
+ * nghttp2 - HTTP/2 C Library
+ *
+ * Copyright (c) 2023 nghttp2 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.
+ */
+#ifndef NGHTTP2_RATELIM_H
+#define NGHTTP2_RATELIM_H
+
+#ifdef HAVE_CONFIG_H
+#  include <config.h>
+#endif /* HAVE_CONFIG_H */
+
+#include <nghttp2/nghttp2.h>
+
+typedef struct nghttp2_ratelim {
+  /* burst is the maximum value of val. */
+  uint64_t burst;
+  /* rate is the amount of value that is regenerated per 1 tstamp. */
+  uint64_t rate;
+  /* val is the amount of value available to drain. */
+  uint64_t val;
+  /* tstamp is the last timestamp in second resolution that is known
+     to this object. */
+  uint64_t tstamp;
+} nghttp2_ratelim;
+
+/* nghttp2_ratelim_init initializes |rl| with the given parameters. */
+void nghttp2_ratelim_init(nghttp2_ratelim *rl, uint64_t burst, uint64_t rate);
+
+/* nghttp2_ratelim_update updates rl->val with the current |tstamp|
+   given in second resolution. */
+void nghttp2_ratelim_update(nghttp2_ratelim *rl, uint64_t tstamp);
+
+/* nghttp2_ratelim_drain drains |n| from rl->val.  It returns 0 if it
+   succeeds, or -1. */
+int nghttp2_ratelim_drain(nghttp2_ratelim *rl, uint64_t n);
+
+#endif /* NGHTTP2_RATELIM_H */
diff --git a/lib/nghttp2_session.c b/lib/nghttp2_session.c
index d877d01..2f83870 100644
--- a/lib/nghttp2_session.c
+++ b/lib/nghttp2_session.c
@@ -36,6 +36,7 @@
 #include "nghttp2_option.h"
 #include "nghttp2_http.h"
 #include "nghttp2_pq.h"
+#include "nghttp2_time.h"
 #include "nghttp2_debug.h"
 
 /*
@@ -443,6 +444,10 @@ static int session_new(nghttp2_session **session_ptr,
       NGHTTP2_DEFAULT_MAX_CONCURRENT_STREAMS;
   (*session_ptr)->pending_enable_push = 1;
 
+  nghttp2_ratelim_init(&(*session_ptr)->stream_reset_ratelim,
+                       NGHTTP2_DEFAULT_STREAM_RESET_BURST,
+                       NGHTTP2_DEFAULT_STREAM_RESET_RATE);
+
   if (server) {
     (*session_ptr)->server = 1;
   }
@@ -527,6 +532,12 @@ static int session_new(nghttp2_session **session_ptr,
         option->max_settings) {
       (*session_ptr)->max_settings = option->max_settings;
     }
+
+    if (option->opt_set_mask & NGHTTP2_OPT_STREAM_RESET_RATE_LIMIT) {
+      nghttp2_ratelim_init(&(*session_ptr)->stream_reset_ratelim,
+                           option->stream_reset_burst,
+                           option->stream_reset_rate);
+    }
   }
 
   rv = nghttp2_hd_deflate_init2(&(*session_ptr)->hd_deflater,
@@ -4142,6 +4153,23 @@ static int session_process_priority_frame(nghttp2_session *session) {
   return nghttp2_session_on_priority_received(session, frame);
 }
 
+static int session_update_stream_reset_ratelim(nghttp2_session *session) {
+  if (!session->server || (session->goaway_flags & NGHTTP2_GOAWAY_SUBMITTED)) {
+    return 0;
+  }
+
+  nghttp2_ratelim_update(&session->stream_reset_ratelim,
+                         nghttp2_time_now_sec());
+
+  if (nghttp2_ratelim_drain(&session->stream_reset_ratelim, 1) == 0) {
+    return 0;
+  }
+
+  return nghttp2_session_add_goaway(session, session->last_recv_stream_id,
+                                    NGHTTP2_INTERNAL_ERROR, NULL, 0,
+                                    NGHTTP2_GOAWAY_AUX_NONE);
+}
+
 int nghttp2_session_on_rst_stream_received(nghttp2_session *session,
                                            nghttp2_frame *frame) {
   int rv;
@@ -4171,7 +4199,8 @@ int nghttp2_session_on_rst_stream_received(nghttp2_session *session,
   if (nghttp2_is_fatal(rv)) {
     return rv;
   }
-  return 0;
+
+  return session_update_stream_reset_ratelim(session);
 }
 
 static int session_process_rst_stream_frame(nghttp2_session *session) {
@@ -6942,6 +6971,9 @@ int nghttp2_session_add_goaway(nghttp2_session *session, int32_t last_stream_id,
     nghttp2_mem_free(mem, item);
     return rv;
   }
+
+  session->goaway_flags |= NGHTTP2_GOAWAY_SUBMITTED;
+
   return 0;
 }
 
diff --git a/lib/nghttp2_session.h b/lib/nghttp2_session.h
index 07bfbb6..9d42992 100644
--- a/lib/nghttp2_session.h
+++ b/lib/nghttp2_session.h
@@ -39,6 +39,7 @@
 #include "nghttp2_buf.h"
 #include "nghttp2_callbacks.h"
 #include "nghttp2_mem.h"
+#include "nghttp2_ratelim.h"
 
 /* The global variable for tests where we want to disable strict
    preface handling. */
@@ -102,6 +103,10 @@ typedef struct {
 /* The default value of maximum number of concurrent streams. */
 #define NGHTTP2_DEFAULT_MAX_CONCURRENT_STREAMS 0xffffffffu
 
+/* The default values for stream reset rate limiter. */
+#define NGHTTP2_DEFAULT_STREAM_RESET_BURST 1000
+#define NGHTTP2_DEFAULT_STREAM_RESET_RATE 33
+
 /* Internal state when receiving incoming frame */
 typedef enum {
   /* Receiving frame header */
@@ -176,7 +181,9 @@ typedef enum {
   /* Flag means GOAWAY was sent */
   NGHTTP2_GOAWAY_SENT = 0x4,
   /* Flag means GOAWAY was received */
-  NGHTTP2_GOAWAY_RECV = 0x8
+  NGHTTP2_GOAWAY_RECV = 0x8,
+  /* Flag means GOAWAY has been submitted at least once */
+  NGHTTP2_GOAWAY_SUBMITTED = 0x10
 } nghttp2_goaway_flag;
 
 /* nghttp2_inflight_settings stores the SETTINGS entries which local
@@ -227,6 +234,9 @@ struct nghttp2_session {
   /* Queue of In-flight SETTINGS values.  SETTINGS bearing ACK is not
      considered as in-flight. */
   nghttp2_inflight_settings *inflight_settings_head;
+  /* Stream reset rate limiter.  If receiving excessive amount of
+     stream resets, GOAWAY will be sent. */
+  nghttp2_ratelim stream_reset_ratelim;
   /* The number of outgoing streams. This will be capped by
      remote_settings.max_concurrent_streams. */
   size_t num_outgoing_streams;
diff --git a/lib/nghttp2_time.c b/lib/nghttp2_time.c
new file mode 100644
index 0000000..2a5f1a6
--- /dev/null
+++ b/lib/nghttp2_time.c
@@ -0,0 +1,62 @@
+/*
+ * nghttp2 - HTTP/2 C Library
+ *
+ * Copyright (c) 2023 nghttp2 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 "nghttp2_time.h"
+
+#ifdef HAVE_TIME_H
+#  include <time.h>
+#endif /* HAVE_TIME_H */
+
+#ifdef HAVE_SYSINFOAPI_H
+#  include <sysinfoapi.h>
+#endif /* HAVE_SYSINFOAPI_H */
+
+#ifndef HAVE_GETTICKCOUNT64
+static uint64_t time_now_sec(void) {
+  time_t t = time(NULL);
+
+  if (t == -1) {
+    return 0;
+  }
+
+  return (uint64_t)t;
+}
+#endif /* HAVE_GETTICKCOUNT64 */
+
+#ifdef HAVE_CLOCK_GETTIME
+uint64_t nghttp2_time_now_sec(void) {
+  struct timespec tp;
+  int rv = clock_gettime(CLOCK_MONOTONIC, &tp);
+
+  if (rv == -1) {
+    return time_now_sec();
+  }
+
+  return (uint64_t)tp.tv_sec;
+}
+#elif defined(HAVE_GETTICKCOUNT64)
+uint64_t nghttp2_time_now_sec(void) { return GetTickCount64() / 1000; }
+#else  /* !HAVE_CLOCK_GETTIME && !HAVE_GETTICKCOUNT64 */
+uint64_t nghttp2_time_now_sec(void) { return time_now_sec(); }
+#endif /* !HAVE_CLOCK_GETTIME && !HAVE_GETTICKCOUNT64 */
diff --git a/lib/nghttp2_time.h b/lib/nghttp2_time.h
new file mode 100644
index 0000000..03c0bbe
--- /dev/null
+++ b/lib/nghttp2_time.h
@@ -0,0 +1,38 @@
+/*
+ * nghttp2 - HTTP/2 C Library
+ *
+ * Copyright (c) 2023 nghttp2 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.
+ */
+#ifndef NGHTTP2_TIME_H
+#define NGHTTP2_TIME_H
+
+#ifdef HAVE_CONFIG_H
+#  include <config.h>
+#endif /* HAVE_CONFIG_H */
+
+#include <nghttp2/nghttp2.h>
+
+/* nghttp2_time_now_sec returns seconds from implementation-specific
+   timepoint.  If it is unable to get seconds, it returns 0. */
+uint64_t nghttp2_time_now_sec(void);
+
+#endif /* NGHTTP2_TIME_H */
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 4250ac3..344c542 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -21,6 +21,7 @@ if(HAVE_CUNIT)
     nghttp2_npn_test.c
     nghttp2_helper_test.c
     nghttp2_buf_test.c
+    nghttp2_ratelim_test.c
   )
 
   add_executable(main EXCLUDE_FROM_ALL
diff --git a/tests/Makefile.am b/tests/Makefile.am
index c3e4392..c130a00 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -40,14 +40,16 @@ OBJECTS = main.c nghttp2_pq_test.c nghttp2_map_test.c nghttp2_queue_test.c \
 	nghttp2_hd_test.c \
 	nghttp2_npn_test.c \
 	nghttp2_helper_test.c \
-	nghttp2_buf_test.c
+	nghttp2_buf_test.c \
+	nghttp2_ratelim_test.c
 
 HFILES = nghttp2_pq_test.h nghttp2_map_test.h nghttp2_queue_test.h \
 	nghttp2_session_test.h \
 	nghttp2_frame_test.h nghttp2_stream_test.h nghttp2_hd_test.h \
 	nghttp2_npn_test.h nghttp2_helper_test.h \
 	nghttp2_test_helper.h \
-	nghttp2_buf_test.h
+	nghttp2_buf_test.h \
+	nghttp2_ratelim_test.h
 
 main_SOURCES = $(HFILES) $(OBJECTS)
 
diff --git a/tests/main.c b/tests/main.c
index 67eb4a1..2605ebd 100644
--- a/tests/main.c
+++ b/tests/main.c
@@ -40,6 +40,7 @@
 #include "nghttp2_npn_test.h"
 #include "nghttp2_helper_test.h"
 #include "nghttp2_buf_test.h"
+#include "nghttp2_ratelim_test.h"
 
 extern int nghttp2_enable_strict_preface;
 
@@ -327,6 +328,8 @@ int main() {
                    test_nghttp2_session_no_closed_streams) ||
       !CU_add_test(pSuite, "session_set_stream_user_data",
                    test_nghttp2_session_set_stream_user_data) ||
+      !CU_add_test(pSuite, "session_stream_reset_ratelim",
+                   test_nghttp2_session_stream_reset_ratelim) ||
       !CU_add_test(pSuite, "http_mandatory_headers",
                    test_nghttp2_http_mandatory_headers) ||
       !CU_add_test(pSuite, "http_content_length",
@@ -423,7 +426,9 @@ int main() {
       !CU_add_test(pSuite, "bufs_advance", test_nghttp2_bufs_advance) ||
       !CU_add_test(pSuite, "bufs_next_present",
                    test_nghttp2_bufs_next_present) ||
-      !CU_add_test(pSuite, "bufs_realloc", test_nghttp2_bufs_realloc)) {
+      !CU_add_test(pSuite, "bufs_realloc", test_nghttp2_bufs_realloc) ||
+      !CU_add_test(pSuite, "ratelim_update", test_nghttp2_ratelim_update) ||
+      !CU_add_test(pSuite, "ratelim_drain", test_nghttp2_ratelim_drain)) {
     CU_cleanup_registry();
     return (int)CU_get_error();
   }
diff --git a/tests/nghttp2_ratelim_test.c b/tests/nghttp2_ratelim_test.c
new file mode 100644
index 0000000..6abece9
--- /dev/null
+++ b/tests/nghttp2_ratelim_test.c
@@ -0,0 +1,101 @@
+/*
+ * nghttp2 - HTTP/2 C Library
+ *
+ * Copyright (c) 2023 nghttp2 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 "nghttp2_ratelim_test.h"
+
+#include <stdio.h>
+
+#include <CUnit/CUnit.h>
+
+#include "nghttp2_ratelim.h"
+
+void test_nghttp2_ratelim_update(void) {
+  nghttp2_ratelim rl;
+
+  nghttp2_ratelim_init(&rl, 1000, 21);
+
+  CU_ASSERT(1000 == rl.val);
+  CU_ASSERT(1000 == rl.burst);
+  CU_ASSERT(21 == rl.rate);
+  CU_ASSERT(0 == rl.tstamp);
+
+  nghttp2_ratelim_update(&rl, 999);
+
+  CU_ASSERT(1000 == rl.val);
+  CU_ASSERT(999 == rl.tstamp);
+
+  nghttp2_ratelim_drain(&rl, 100);
+
+  CU_ASSERT(900 == rl.val);
+
+  nghttp2_ratelim_update(&rl, 1000);
+
+  CU_ASSERT(921 == rl.val);
+
+  nghttp2_ratelim_update(&rl, 1002);
+
+  CU_ASSERT(963 == rl.val);
+
+  nghttp2_ratelim_update(&rl, 1004);
+
+  CU_ASSERT(1000 == rl.val);
+  CU_ASSERT(1004 == rl.tstamp);
+
+  /* timer skew */
+  nghttp2_ratelim_init(&rl, 1000, 21);
+  nghttp2_ratelim_update(&rl, 1);
+
+  CU_ASSERT(1000 == rl.val);
+
+  nghttp2_ratelim_update(&rl, 0);
+
+  CU_ASSERT(1000 == rl.val);
+
+  /* rate * duration overflow */
+  nghttp2_ratelim_init(&rl, 1000, 100);
+  nghttp2_ratelim_drain(&rl, 999);
+
+  CU_ASSERT(1 == rl.val);
+
+  nghttp2_ratelim_update(&rl, UINT64_MAX);
+
+  CU_ASSERT(1000 == rl.val);
+
+  /* val + rate * duration overflow */
+  nghttp2_ratelim_init(&rl, UINT64_MAX - 1, 2);
+  nghttp2_ratelim_update(&rl, 1);
+
+  CU_ASSERT(UINT64_MAX - 1 == rl.val);
+}
+
+void test_nghttp2_ratelim_drain(void) {
+  nghttp2_ratelim rl;
+
+  nghttp2_ratelim_init(&rl, 100, 7);
+
+  CU_ASSERT(-1 == nghttp2_ratelim_drain(&rl, 101));
+  CU_ASSERT(0 == nghttp2_ratelim_drain(&rl, 51));
+  CU_ASSERT(0 == nghttp2_ratelim_drain(&rl, 49));
+  CU_ASSERT(-1 == nghttp2_ratelim_drain(&rl, 1));
+}
diff --git a/tests/nghttp2_ratelim_test.h b/tests/nghttp2_ratelim_test.h
new file mode 100644
index 0000000..02b2f2b
--- /dev/null
+++ b/tests/nghttp2_ratelim_test.h
@@ -0,0 +1,35 @@
+/*
+ * nghttp2 - HTTP/2 C Library
+ *
+ * Copyright (c) 2023 nghttp2 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.
+ */
+#ifndef NGHTTP2_RATELIM_TEST_H
+#define NGHTTP2_RATELIM_TEST_H
+
+#ifdef HAVE_CONFIG_H
+#  include <config.h>
+#endif /* HAVE_CONFIG_H */
+
+void test_nghttp2_ratelim_update(void);
+void test_nghttp2_ratelim_drain(void);
+
+#endif /* NGHTTP2_RATELIM_TEST_H */
diff --git a/tests/nghttp2_session_test.c b/tests/nghttp2_session_test.c
index 5b80b0f..e5a0138 100644
--- a/tests/nghttp2_session_test.c
+++ b/tests/nghttp2_session_test.c
@@ -10988,6 +10988,109 @@ void test_nghttp2_session_set_stream_user_data(void) {
   nghttp2_session_del(session);
 }
 
+void test_nghttp2_session_stream_reset_ratelim(void) {
+  nghttp2_session *session;
+  nghttp2_session_callbacks callbacks;
+  nghttp2_frame frame;
+  ssize_t rv;
+  nghttp2_bufs bufs;
+  nghttp2_buf *buf;
+  nghttp2_mem *mem;
+  size_t i;
+  nghttp2_hd_deflater deflater;
+  size_t nvlen;
+  nghttp2_nv *nva;
+  int32_t stream_id;
+  nghttp2_outbound_item *item;
+  nghttp2_option *option;
+
+  mem = nghttp2_mem_default();
+  frame_pack_bufs_init(&bufs);
+
+  memset(&callbacks, 0, sizeof(nghttp2_session_callbacks));
+  callbacks.send_callback = null_send_callback;
+
+  nghttp2_option_new(&option);
+  nghttp2_option_set_stream_reset_rate_limit(
+      option, NGHTTP2_DEFAULT_STREAM_RESET_BURST, 0);
+
+  nghttp2_session_server_new2(&session, &callbacks, NULL, option);
+
+  nghttp2_frame_settings_init(&frame.settings, NGHTTP2_FLAG_NONE, NULL, 0);
+  rv = nghttp2_frame_pack_settings(&bufs, &frame.settings);
+
+  CU_ASSERT(0 == rv);
+
+  nghttp2_frame_settings_free(&frame.settings, mem);
+
+  buf = &bufs.head->buf;
+  rv = nghttp2_session_mem_recv(session, buf->pos, nghttp2_buf_len(buf));
+
+  CU_ASSERT((ssize_t)nghttp2_buf_len(buf) == rv);
+
+  /* Send SETTINGS ACK */
+  rv = nghttp2_session_send(session);
+
+  CU_ASSERT(0 == rv);
+
+  nghttp2_hd_deflate_init(&deflater, mem);
+
+  for (i = 0; i < NGHTTP2_DEFAULT_STREAM_RESET_BURST + 2; ++i) {
+    stream_id = (int32_t)(i * 2 + 1);
+
+    nghttp2_bufs_reset(&bufs);
+
+    /* HEADERS */
+    nvlen = ARRLEN(reqnv);
+    nghttp2_nv_array_copy(&nva, reqnv, nvlen, mem);
+    nghttp2_frame_headers_init(&frame.headers, NGHTTP2_FLAG_END_HEADERS,
+                               stream_id, NGHTTP2_HCAT_HEADERS, NULL, nva,
+                               nvlen);
+    rv = nghttp2_frame_pack_headers(&bufs, &frame.headers, &deflater);
+
+    CU_ASSERT(0 == rv);
+
+    nghttp2_frame_headers_free(&frame.headers, mem);
+
+    buf = &bufs.head->buf;
+    rv = nghttp2_session_mem_recv(session, buf->pos, nghttp2_buf_len(buf));
+
+    CU_ASSERT((ssize_t)nghttp2_buf_len(buf) == rv);
+
+    nghttp2_bufs_reset(&bufs);
+
+    /* RST_STREAM */
+    nghttp2_frame_rst_stream_init(&frame.rst_stream, stream_id,
+                                  NGHTTP2_NO_ERROR);
+    nghttp2_frame_pack_rst_stream(&bufs, &frame.rst_stream);
+    nghttp2_frame_rst_stream_free(&frame.rst_stream);
+
+    buf = &bufs.head->buf;
+    rv = nghttp2_session_mem_recv(session, buf->pos, nghttp2_buf_len(buf));
+
+    CU_ASSERT((ssize_t)nghttp2_buf_len(buf) == rv);
+
+    if (i < NGHTTP2_DEFAULT_STREAM_RESET_BURST) {
+      CU_ASSERT(0 == nghttp2_outbound_queue_size(&session->ob_reg));
+
+      continue;
+    }
+
+    CU_ASSERT(1 == nghttp2_outbound_queue_size(&session->ob_reg));
+
+    item = nghttp2_session_get_next_ob_item(session);
+
+    CU_ASSERT(NGHTTP2_GOAWAY == item->frame.hd.type);
+    CU_ASSERT(NGHTTP2_DEFAULT_STREAM_RESET_BURST * 2 + 1 ==
+              item->frame.goaway.last_stream_id);
+  }
+
+  nghttp2_hd_deflate_free(&deflater);
+  nghttp2_session_del(session);
+  nghttp2_bufs_free(&bufs);
+  nghttp2_option_del(option);
+}
+
 static void check_nghttp2_http_recv_headers_fail(
     nghttp2_session *session, nghttp2_hd_deflater *deflater, int32_t stream_id,
     int stream_state, const nghttp2_nv *nva, size_t nvlen) {
diff --git a/tests/nghttp2_session_test.h b/tests/nghttp2_session_test.h
index 818c808..fcbb987 100644
--- a/tests/nghttp2_session_test.h
+++ b/tests/nghttp2_session_test.h
@@ -161,6 +161,7 @@ void test_nghttp2_session_removed_closed_stream(void);
 void test_nghttp2_session_pause_data(void);
 void test_nghttp2_session_no_closed_streams(void);
 void test_nghttp2_session_set_stream_user_data(void);
+void test_nghttp2_session_stream_reset_ratelim(void);
 void test_nghttp2_http_mandatory_headers(void);
 void test_nghttp2_http_content_length(void);
 void test_nghttp2_http_content_length_mismatch(void);
-- 
2.27.0
