nghttp2/src/HttpServer.cc

1784 lines
45 KiB
C++

/*
* nghttp2 - HTTP/2 C Library
*
* Copyright (c) 2013 Tatsuhiro Tsujikawa
*
* 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 "HttpServer.h"
#include <sys/stat.h>
#include <sys/socket.h>
#include <netdb.h>
#include <unistd.h>
#include <fcntl.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <cassert>
#include <set>
#include <iostream>
#include <thread>
#include <openssl/err.h>
#include <zlib.h>
#include <event.h>
#include <event2/listener.h>
#include <event2/bufferevent.h>
#ifdef __cplusplus
extern "C" {
#endif
#include "nghttp2_helper.h"
#ifdef __cplusplus
}
#endif
#include "app_helper.h"
#include "http2.h"
#include "util.h"
#ifndef O_BINARY
# define O_BINARY (0)
#endif // O_BINARY
namespace nghttp2 {
namespace {
const std::string STATUS_200 = "200";
const std::string STATUS_304 = "304";
const std::string STATUS_400 = "400";
const std::string STATUS_404 = "404";
const std::string DEFAULT_HTML = "index.html";
const std::string NGHTTPD_SERVER = "nghttpd nghttp2/" NGHTTP2_VERSION;
} // namespace
namespace {
void delete_handler(Http2Handler *handler)
{
handler->remove_self();
delete handler;
}
} // namespace
namespace {
void print_session_id(int64_t id)
{
std::cout << "[id=" << id << "] ";
}
} // namespace
namespace {
void append_nv(Stream *stream, const std::vector<nghttp2_nv>& nva)
{
for(auto& nv : nva) {
http2::split_add_header(stream->headers,
nv.name, nv.namelen, nv.value, nv.valuelen,
nv.flags & NGHTTP2_NV_FLAG_NO_INDEX);
}
}
} // namespace
Config::Config()
: stream_read_timeout{60, 0},
stream_write_timeout{60, 0},
data_ptr(nullptr),
padding(0),
num_worker(1),
header_table_size(-1),
port(0),
verbose(false),
daemon(false),
verify_client(false),
no_tls(false),
error_gzip(false)
{}
Stream::Stream(Http2Handler *handler, int32_t stream_id)
: handler(handler),
rtimer(nullptr),
wtimer(nullptr),
stream_id(stream_id),
file(-1),
enable_compression(false)
{}
Stream::~Stream()
{
if(file != -1) {
close(file);
}
if(wtimer) {
event_free(wtimer);
}
if(rtimer) {
event_free(rtimer);
}
}
namespace {
void stream_timeout_cb(evutil_socket_t fd, short what, void *arg)
{
int rv;
auto stream = static_cast<Stream*>(arg);
auto hd = stream->handler;
auto config = hd->get_config();
if(config->verbose) {
print_session_id(hd->session_id());
print_timer();
std::cout << " timeout stream_id=" << stream->stream_id << std::endl;
}
hd->submit_rst_stream(stream, NGHTTP2_INTERNAL_ERROR);
rv = hd->on_write();
if(rv == -1) {
delete_handler(hd);
}
}
} // namespace
namespace {
void add_stream_read_timeout(Stream *stream)
{
auto hd = stream->handler;
auto config = hd->get_config();
evtimer_add(stream->rtimer, &config->stream_read_timeout);
}
} // namespace
namespace {
void add_stream_read_timeout_if_pending(Stream *stream)
{
auto hd = stream->handler;
auto config = hd->get_config();
if(evtimer_pending(stream->rtimer, nullptr)) {
evtimer_add(stream->rtimer, &config->stream_read_timeout);
}
}
} // namespace
namespace {
void add_stream_write_timeout(Stream *stream)
{
auto hd = stream->handler;
auto config = hd->get_config();
evtimer_add(stream->wtimer, &config->stream_write_timeout);
}
} // namespace
namespace {
void remove_stream_read_timeout(Stream *stream)
{
if(stream->rtimer) {
evtimer_del(stream->rtimer);
}
}
} // namespace
namespace {
void remove_stream_write_timeout(Stream *stream)
{
if(stream->wtimer) {
evtimer_del(stream->wtimer);
}
}
} // namespace
class Sessions {
public:
Sessions(event_base *evbase, const Config *config, SSL_CTX *ssl_ctx)
: evbase_(evbase),
config_(config),
ssl_ctx_(ssl_ctx),
next_session_id_(1)
{}
~Sessions()
{
for(auto handler : handlers_) {
delete handler;
}
}
void add_handler(Http2Handler *handler)
{
handlers_.insert(handler);
}
void remove_handler(Http2Handler *handler)
{
handlers_.erase(handler);
}
SSL_CTX* get_ssl_ctx() const
{
return ssl_ctx_;
}
SSL* ssl_session_new(int fd)
{
SSL *ssl = SSL_new(ssl_ctx_);
if(!ssl) {
std::cerr << "SSL_new() failed" << std::endl;
return nullptr;
}
if(SSL_set_fd(ssl, fd) == 0) {
std::cerr << "SSL_set_fd() failed" << std::endl;
SSL_free(ssl);
return nullptr;
}
return ssl;
}
const Config* get_config() const
{
return config_;
}
event_base* get_evbase() const
{
return evbase_;
}
int64_t get_next_session_id()
{
auto session_id = next_session_id_;
if(next_session_id_ == std::numeric_limits<int64_t>::max()) {
next_session_id_ = 1;
}
return session_id;
}
void accept_connection(int fd)
{
int val = 1;
(void)setsockopt(fd, IPPROTO_TCP, TCP_NODELAY,
reinterpret_cast<char *>(&val), sizeof(val));
SSL *ssl = nullptr;
if(ssl_ctx_) {
ssl = ssl_session_new(fd);
if(!ssl) {
close(fd);
return;
}
}
auto handler = util::make_unique<Http2Handler>(this, fd, ssl,
get_next_session_id());
handler->setup_bev();
if(!ssl) {
if(handler->on_connect() != 0) {
return;
}
}
add_handler(handler.release());
}
private:
std::set<Http2Handler*> handlers_;
event_base *evbase_;
const Config *config_;
SSL_CTX *ssl_ctx_;
int64_t next_session_id_;
};
namespace {
void on_session_closed(Http2Handler *hd, int64_t session_id)
{
if(hd->get_config()->verbose) {
print_session_id(session_id);
print_timer();
std::cout << " closed" << std::endl;
}
}
} // namespace
namespace {
void fill_callback(nghttp2_session_callbacks& callbacks, const Config *config);
} // namespace
Http2Handler::Http2Handler(Sessions *sessions,
int fd, SSL *ssl, int64_t session_id)
: session_id_(session_id),
session_(nullptr),
sessions_(sessions),
ssl_(ssl),
rev_(nullptr),
wev_(nullptr),
settings_timerev_(nullptr),
pending_data_(nullptr),
pending_datalen_(0),
left_connhd_len_(NGHTTP2_CLIENT_CONNECTION_PREFACE_LEN),
fd_(fd)
{
nghttp2_buf_wrap_init(&sendbuf_, sendbufarray_, sizeof(sendbufarray_));
}
Http2Handler::~Http2Handler()
{
on_session_closed(this, session_id_);
if(rev_) {
event_free(rev_);
}
if(wev_) {
event_free(wev_);
}
if(settings_timerev_) {
event_free(settings_timerev_);
}
nghttp2_session_del(session_);
if(ssl_) {
SSL_set_shutdown(ssl_, SSL_RECEIVED_SHUTDOWN);
SSL_shutdown(ssl_);
}
if(ssl_) {
SSL_free(ssl_);
}
shutdown(fd_, SHUT_WR);
close(fd_);
}
void Http2Handler::remove_self()
{
sessions_->remove_handler(this);
}
namespace {
void rev_cb(evutil_socket_t fd, short what, void *arg)
{
int rv;
auto handler = static_cast<Http2Handler*>(arg);
if(what & EV_READ) {
rv = handler->on_read();
if(rv == -1) {
delete_handler(handler);
}
}
}
} // namespace
namespace {
void wev_cb(evutil_socket_t fd, short what, void *arg)
{
int rv;
auto handler = static_cast<Http2Handler*>(arg);
if(what & EV_WRITE) {
rv = handler->on_write();
if(rv == -1) {
delete_handler(handler);
}
}
}
} // namespace
int Http2Handler::handle_ssl_temporal_error(int err)
{
auto sslerr = SSL_get_error(ssl_, err);
switch(sslerr) {
case SSL_ERROR_WANT_READ:
event_add(rev_, nullptr);
return 1;
case SSL_ERROR_WANT_WRITE:
event_add(wev_, nullptr);
return 1;
}
return -1;
}
int Http2Handler::tls_write(const uint8_t *data, size_t datalen)
{
int rv;
size_t max_avail;
// OpenSSL sends at most 16K bytes
max_avail = ssl_ ?
std::min((ssize_t)16384, nghttp2_buf_avail(&sendbuf_)) :
nghttp2_buf_avail(&sendbuf_);
if(max_avail < datalen) {
if(nghttp2_buf_len(&sendbuf_) > 0) {
rv = tls_write_pending();
if(rv == -1) {
return -1;
}
if(rv == 1) {
pending_data_ = data;
pending_datalen_ = datalen;
return 1;
}
}
assert(nghttp2_buf_avail(&sendbuf_) >= (ssize_t)datalen);
}
//std::cerr << "DBG: copy " << datalen << " bytes" << std::endl;
sendbuf_.last = nghttp2_cpymem(sendbuf_.last, data, datalen);
return 0;
}
int Http2Handler::tls_write_pending()
{
int rv;
if(nghttp2_buf_len(&sendbuf_) == 0) {
return 0;
}
for(;;) {
if(ssl_) {
ERR_clear_error();
rv = SSL_write(ssl_, sendbuf_.pos, nghttp2_buf_len(&sendbuf_));
if(rv == 0) {
return -1;
}
if(rv < 0) {
return handle_ssl_temporal_error(rv);
}
} else {
while((rv = write(fd_, sendbuf_.pos, nghttp2_buf_len(&sendbuf_))) &&
rv == -1 && errno == EINTR);
if(rv == 0) {
continue;
}
if(rv < 0) {
if(errno == EAGAIN || errno == EWOULDBLOCK) {
event_add(wev_, nullptr);
return 1;
}
return -1;
}
}
sendbuf_.pos += rv;
if(nghttp2_buf_len(&sendbuf_) == 0) {
nghttp2_buf_reset(&sendbuf_);
if(pending_data_) {
assert(nghttp2_buf_avail(&sendbuf_) >= (ssize_t)pending_datalen_);
sendbuf_.last = nghttp2_cpymem(sendbuf_.last,
pending_data_, pending_datalen_);
pending_data_ = nullptr;
pending_datalen_ = 0;
continue;
}
return 0;
}
}
}
namespace {
void tls_handshake_cb(evutil_socket_t fd, short what, void *arg)
{
int rv;
auto handler = static_cast<Http2Handler*>(arg);
if(what & (EV_READ | EV_WRITE)) {
rv = handler->tls_handshake();
if(rv == -1) {
delete_handler(handler);
return;
}
if(rv == 1) {
return;
}
rv = handler->on_connect();
if(rv != 0) {
delete_handler(handler);
return;
}
}
}
} // namespace
int Http2Handler::tls_handshake()
{
int rv;
ERR_clear_error();
rv = SSL_accept(ssl_);
if(rv == 0) {
return -1;
}
if(rv < 0) {
auto sslerr = SSL_get_error(ssl_, rv);
switch(sslerr) {
case SSL_ERROR_NONE:
case SSL_ERROR_WANT_X509_LOOKUP:
case SSL_ERROR_ZERO_RETURN:
break;
case SSL_ERROR_WANT_READ:
event_add(rev_, nullptr);
return 1;
case SSL_ERROR_WANT_WRITE:
event_add(wev_, nullptr);
return 1;
}
}
if(sessions_->get_config()->verbose) {
std::cerr << "SSL/TLS handshake completed" << std::endl;
}
if(verify_npn_result() != 0) {
return -1;
}
event_del(rev_);
event_del(wev_);
event_assign(rev_, sessions_->get_evbase(), fd_, EV_READ, rev_cb, this);
event_assign(wev_, sessions_->get_evbase(), fd_, EV_WRITE, wev_cb, this);
return 0;
}
int Http2Handler::setup_bev()
{
if(ssl_) {
rev_ = event_new(sessions_->get_evbase(), fd_, EV_READ, tls_handshake_cb,
this);
wev_ = event_new(sessions_->get_evbase(), fd_, EV_WRITE, tls_handshake_cb,
this);
} else {
rev_ = event_new(sessions_->get_evbase(), fd_, EV_READ, rev_cb, this);
wev_ = event_new(sessions_->get_evbase(), fd_, EV_WRITE, wev_cb, this);
}
event_add(rev_, nullptr);
// TODO set up timeout here
return 0;
}
int Http2Handler::wait_events()
{
int active = 0;
if(nghttp2_session_want_read(session_)) {
event_add(rev_, nullptr);
active = 1;
}
if(nghttp2_session_want_write(session_)) {
event_add(wev_, nullptr);
active = 1;
}
return active ? 0 : -1;
}
int Http2Handler::on_read()
{
int rv;
uint8_t buf[16384];
uint8_t *bufp;
size_t nread;
if(ssl_) {
ERR_clear_error();
rv = SSL_read(ssl_, buf, sizeof(buf));
if(rv == 0) {
return -1;
}
if(rv < 0) {
return handle_ssl_temporal_error(rv);
}
} else {
while((rv = read(fd_, buf, sizeof(buf))) && rv == -1 && errno == EINTR);
if(rv == 0) {
return -1;
}
if(rv < 0) {
if(errno == EAGAIN || errno == EWOULDBLOCK) {
event_add(rev_, nullptr);
return 1;
}
return -1;
}
}
nread = rv;
bufp = buf;
if(left_connhd_len_ > 0) {
auto len = std::min(left_connhd_len_, nread);
const char *conhead = NGHTTP2_CLIENT_CONNECTION_PREFACE;
if(memcmp(conhead + NGHTTP2_CLIENT_CONNECTION_PREFACE_LEN -
left_connhd_len_, bufp, len) != 0) {
return -1;
}
left_connhd_len_ -= len;
nread -= len;
if(nread == 0) {
wait_events();
return 0;
}
bufp += len;
}
rv = nghttp2_session_mem_recv(session_, bufp, nread);
if(rv < 0) {
std::cerr << "nghttp2_session_mem_recv() returned error: "
<< nghttp2_strerror(rv) << std::endl;
return -1;
}
return wait_events();
}
int Http2Handler::on_write()
{
int rv;
//std::cerr << "DBG: on_write" << std::endl;
rv = tls_write_pending();
if(rv != 0) {
return rv;
}
for(;;) {
const uint8_t *data;
auto datalen = nghttp2_session_mem_send(session_, &data);
if(datalen < 0) {
std::cerr << "nghttp2_session_mem_send() returned error: "
<< nghttp2_strerror(datalen) << std::endl;
return -1;
}
if(datalen == 0) {
break;
}
rv = tls_write(data, datalen);
if(rv != 0) {
return rv;
}
}
rv = tls_write_pending();
if(rv != 0) {
return rv;
}
return wait_events();
}
namespace {
void settings_timeout_cb(evutil_socket_t fd, short what, void *arg)
{
auto hd = static_cast<Http2Handler*>(arg);
hd->terminate_session(NGHTTP2_SETTINGS_TIMEOUT);
hd->on_write();
}
} // namespace
int Http2Handler::on_connect()
{
int r;
nghttp2_session_callbacks callbacks;
fill_callback(callbacks, sessions_->get_config());
r = nghttp2_session_server_new(&session_, &callbacks, this);
if(r != 0) {
return r;
}
nghttp2_settings_entry entry[4];
size_t niv = 2;
entry[0].settings_id = NGHTTP2_SETTINGS_MAX_CONCURRENT_STREAMS;
entry[0].value = 100;
entry[1].settings_id = NGHTTP2_SETTINGS_COMPRESS_DATA;
entry[1].value = 1;
if(sessions_->get_config()->header_table_size >= 0) {
entry[niv].settings_id = NGHTTP2_SETTINGS_HEADER_TABLE_SIZE;
entry[niv].value = sessions_->get_config()->header_table_size;
++niv;
}
r = nghttp2_submit_settings(session_, NGHTTP2_FLAG_NONE, entry, niv);
if(r != 0) {
return r;
}
assert(settings_timerev_ == nullptr);
settings_timerev_ = evtimer_new(sessions_->get_evbase(), settings_timeout_cb,
this);
// SETTINGS ACK timeout is 10 seconds for now
timeval settings_timeout = { 10, 0 };
evtimer_add(settings_timerev_, &settings_timeout);
return on_write();
}
int Http2Handler::verify_npn_result()
{
const unsigned char *next_proto = nullptr;
unsigned int next_proto_len;
// Check the negotiated protocol in NPN or ALPN
SSL_get0_next_proto_negotiated(ssl_, &next_proto, &next_proto_len);
for(int i = 0; i < 2; ++i) {
if(next_proto) {
std::string proto(next_proto, next_proto+next_proto_len);
if(sessions_->get_config()->verbose) {
std::cout << "The negotiated protocol: " << proto << std::endl;
}
if(proto == NGHTTP2_PROTO_VERSION_ID) {
return 0;
}
break;
} else {
#if OPENSSL_VERSION_NUMBER >= 0x10002000L
SSL_get0_alpn_selected(ssl_, &next_proto, &next_proto_len);
#else // OPENSSL_VERSION_NUMBER < 0x10002000L
break;
#endif // OPENSSL_VERSION_NUMBER < 0x10002000L
}
}
if(sessions_->get_config()->verbose) {
std::cerr << "Client did not advertise HTTP/2 protocol."
<< " (nghttp2 expects " << NGHTTP2_PROTO_VERSION_ID << ")"
<< std::endl;
}
return -1;
}
int Http2Handler::submit_file_response(const std::string& status,
Stream *stream,
time_t last_modified,
off_t file_length,
nghttp2_data_provider *data_prd)
{
std::string date_str = util::http_date(time(0));
std::string content_length = util::to_str(file_length);
std::string last_modified_str;
auto nva = std::vector<nghttp2_nv>{
http2::make_nv_ls(":status", status),
http2::make_nv_ls("server", NGHTTPD_SERVER),
http2::make_nv_ls("content-length", content_length),
http2::make_nv_ll("cache-control", "max-age=3600"),
http2::make_nv_ls("date", date_str),
};
if(last_modified != 0) {
last_modified_str = util::http_date(last_modified);
nva.push_back(http2::make_nv_ls("last-modified", last_modified_str));
}
return nghttp2_submit_response(session_, stream->stream_id,
nva.data(), nva.size(), data_prd);
}
int Http2Handler::submit_response
(const std::string& status,
int32_t stream_id,
const std::vector<std::pair<std::string, std::string>>& headers,
nghttp2_data_provider *data_prd)
{
std::string date_str = util::http_date(time(0));
auto nva = std::vector<nghttp2_nv>{
http2::make_nv_ls(":status", status),
http2::make_nv_ls("server", NGHTTPD_SERVER),
http2::make_nv_ls("date", date_str)
};
for(size_t i = 0; i < headers.size(); ++i) {
nva.push_back(http2::make_nv(headers[i].first, headers[i].second, false));
}
int r = nghttp2_submit_response(session_, stream_id, nva.data(), nva.size(),
data_prd);
return r;
}
int Http2Handler::submit_response(const std::string& status,
int32_t stream_id,
nghttp2_data_provider *data_prd)
{
auto nva = std::vector<nghttp2_nv>{
http2::make_nv_ls(":status", status),
http2::make_nv_ls("server", NGHTTPD_SERVER)
};
return nghttp2_submit_response(session_, stream_id, nva.data(), nva.size(),
data_prd);
}
int Http2Handler::submit_push_promise(Stream *stream,
const std::string& push_path)
{
std::string authority;
auto itr = std::lower_bound(std::begin(stream->headers),
std::end(stream->headers),
Header(":authority", ""));
if(itr == std::end(stream->headers) || (*itr).name != ":authority") {
itr = std::lower_bound(std::begin(stream->headers),
std::end(stream->headers),
Header("host", ""));
}
auto nva = std::vector<nghttp2_nv>{
http2::make_nv_ll(":method", "GET"),
http2::make_nv_ls(":path", push_path),
get_config()->no_tls ?
http2::make_nv_ll(":scheme", "http") :
http2::make_nv_ll(":scheme", "https"),
http2::make_nv_ls(":authority", (*itr).value)
};
auto promised_stream_id =
nghttp2_submit_push_promise(session_, NGHTTP2_FLAG_END_HEADERS,
stream->stream_id, nva.data(), nva.size(),
nullptr);
if(promised_stream_id < 0) {
return promised_stream_id;
}
auto promised_stream = util::make_unique<Stream>(this, promised_stream_id);
append_nv(promised_stream.get(), http2::sort_nva(nva.data(), nva.size()));
add_stream(promised_stream_id, std::move(promised_stream));
return 0;
}
int Http2Handler::submit_rst_stream(Stream *stream,
nghttp2_error_code error_code)
{
remove_stream_read_timeout(stream);
remove_stream_write_timeout(stream);
return nghttp2_submit_rst_stream(session_, NGHTTP2_FLAG_NONE,
stream->stream_id, error_code);
}
void Http2Handler::add_stream(int32_t stream_id, std::unique_ptr<Stream> stream)
{
id2stream_[stream_id] = std::move(stream);
}
void Http2Handler::remove_stream(int32_t stream_id)
{
id2stream_.erase(stream_id);
}
Stream* Http2Handler::get_stream(int32_t stream_id)
{
auto itr = id2stream_.find(stream_id);
if(itr == std::end(id2stream_)) {
return nullptr;
} else {
return (*itr).second.get();
}
}
int64_t Http2Handler::session_id() const
{
return session_id_;
}
Sessions* Http2Handler::get_sessions() const
{
return sessions_;
}
const Config* Http2Handler::get_config() const
{
return sessions_->get_config();
}
size_t Http2Handler::get_left_connhd_len() const
{
return left_connhd_len_;
}
void Http2Handler::set_left_connhd_len(size_t left)
{
left_connhd_len_ = left;
}
void Http2Handler::remove_settings_timer()
{
if(settings_timerev_) {
evtimer_del(settings_timerev_);
event_free(settings_timerev_);
settings_timerev_ = nullptr;
}
}
void Http2Handler::terminate_session(nghttp2_error_code error_code)
{
nghttp2_session_terminate_session(session_, error_code);
}
void Http2Handler::decide_compression(const std::string& path, Stream *stream)
{
if(nghttp2_session_get_remote_settings
(session_, NGHTTP2_SETTINGS_COMPRESS_DATA) == 1 &&
(util::endsWith(path, ".html") ||
util::endsWith(path, ".js") ||
util::endsWith(path, ".css") ||
util::endsWith(path, ".txt"))) {
stream->enable_compression = true;
}
}
ssize_t file_read_callback
(nghttp2_session *session, int32_t stream_id,
uint8_t *buf, size_t length, uint32_t *data_flags,
nghttp2_data_source *source, void *user_data)
{
auto hd = static_cast<Http2Handler*>(user_data);
auto stream = hd->get_stream(stream_id);
int fd = source->fd;
ssize_t nread;
ssize_t rv;
// Compressing too small data is not efficient?
if(length >= 1024 && stream && stream->enable_compression) {
uint8_t srcbuf[4096];
auto maxread = std::min(length, sizeof(srcbuf));
while((nread = read(fd, srcbuf, maxread)) == -1 && errno == EINTR);
if(nread == -1) {
if(stream) {
remove_stream_read_timeout(stream);
remove_stream_write_timeout(stream);
}
return NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE;
}
if(nread > 0) {
rv = deflate_data(buf, length, srcbuf, nread);
if(rv < 0) {
memcpy(buf, srcbuf, nread);
} else {
nread = rv;
*data_flags |= NGHTTP2_DATA_FLAG_COMPRESSED;
}
}
} else {
while((nread = read(fd, buf, length)) == -1 && errno == EINTR);
if(nread == -1) {
if(stream) {
remove_stream_read_timeout(stream);
remove_stream_write_timeout(stream);
}
return NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE;
}
}
if(nread == 0) {
*data_flags |= NGHTTP2_DATA_FLAG_EOF;
}
return nread;
}
namespace {
bool check_url(const std::string& url)
{
// We don't like '\' in url.
return !url.empty() && url[0] == '/' &&
url.find('\\') == std::string::npos &&
url.find("/../") == std::string::npos &&
url.find("/./") == std::string::npos &&
!util::endsWith(url, "/..") && !util::endsWith(url, "/.");
}
} // namespace
namespace {
void prepare_status_response(Stream *stream, Http2Handler *hd,
const std::string& status)
{
int pipefd[2];
if(status == STATUS_304 || pipe(pipefd) == -1) {
hd->submit_response(status, stream->stream_id, 0);
return;
}
std::string body;
body.reserve(256);
body = "<html><head><title>";
body += status;
body += "</title></head><body><h1>";
body += status;
body += "</h1><hr><address>";
body += NGHTTPD_SERVER;
body += " at port ";
body += util::utos(hd->get_config()->port);
body += "</address>";
body += "</body></html>";
std::vector<std::pair<std::string, std::string>> headers;
if(hd->get_config()->error_gzip) {
gzFile write_fd = gzdopen(pipefd[1], "w");
gzwrite(write_fd, body.c_str(), body.size());
gzclose(write_fd);
headers.emplace_back("content-encoding", "gzip");
} else {
auto rv = write(pipefd[1], body.c_str(), body.size());
if(rv != static_cast<ssize_t>(body.size())) {
std::cerr << "Could not write all response body: " << rv << std::endl;
}
}
close(pipefd[1]);
stream->file = pipefd[0];
nghttp2_data_provider data_prd;
data_prd.source.fd = pipefd[0];
data_prd.read_callback = file_read_callback;
headers.emplace_back("content-type", "text/html; charset=UTF-8");
hd->submit_response(status, stream->stream_id, headers, &data_prd);
}
} // namespace
namespace {
void prepare_response(Stream *stream, Http2Handler *hd, bool allow_push = true)
{
int rv;
auto url = (*std::lower_bound(std::begin(stream->headers),
std::end(stream->headers),
Header(":path", ""))).value;
auto ims = std::lower_bound(std::begin(stream->headers),
std::end(stream->headers),
Header("if-modified-since", ""));
time_t last_mod = 0;
bool last_mod_found = false;
if(ims != std::end(stream->headers) &&
(*ims).name == "if-modified-since") {
last_mod_found = true;
last_mod = util::parse_http_date((*ims).value);
}
auto query_pos = url.find("?");
if(query_pos != std::string::npos) {
// Do not response to this request to allow clients to test timeouts.
if(url.find("nghttpd_do_not_respond_to_req=yes",
query_pos) != std::string::npos) {
return;
}
url = url.substr(0, query_pos);
}
url = util::percentDecode(url.begin(), url.end());
if(!check_url(url)) {
prepare_status_response(stream, hd, STATUS_404);
return;
}
auto push_itr = hd->get_config()->push.find(url);
if(allow_push && push_itr != std::end(hd->get_config()->push)) {
for(auto& push_path : (*push_itr).second) {
rv = hd->submit_push_promise(stream, push_path);
if(rv != 0) {
std::cerr << "nghttp2_submit_push_promise() returned error: "
<< nghttp2_strerror(rv) << std::endl;
}
}
}
std::string path = hd->get_config()->htdocs+url;
if(path[path.size()-1] == '/') {
path += DEFAULT_HTML;
}
int file = open(path.c_str(), O_RDONLY | O_BINARY);
if(file == -1) {
prepare_status_response(stream, hd, STATUS_404);
} else {
struct stat buf;
if(fstat(file, &buf) == -1) {
close(file);
prepare_status_response(stream, hd, STATUS_404);
} else {
stream->file = file;
nghttp2_data_provider data_prd;
data_prd.source.fd = file;
data_prd.read_callback = file_read_callback;
if(last_mod_found && buf.st_mtime <= last_mod) {
prepare_status_response(stream, hd, STATUS_304);
} else {
hd->decide_compression(path, stream);
hd->submit_file_response(STATUS_200, stream, buf.st_mtime,
buf.st_size, &data_prd);
}
}
}
}
} // namespace
namespace {
const char *REQUIRED_HEADERS[] = {
":method", ":path", ":scheme", nullptr
};
} // namespace
namespace {
int on_header_callback(nghttp2_session *session,
const nghttp2_frame *frame,
const uint8_t *name, size_t namelen,
const uint8_t *value, size_t valuelen,
uint8_t flags,
void *user_data)
{
auto hd = static_cast<Http2Handler*>(user_data);
if(hd->get_config()->verbose) {
print_session_id(hd->session_id());
verbose_on_header_callback(session, frame, name, namelen, value, valuelen,
flags, user_data);
}
if(frame->hd.type != NGHTTP2_HEADERS ||
frame->headers.cat != NGHTTP2_HCAT_REQUEST) {
return 0;
}
auto stream = hd->get_stream(frame->hd.stream_id);
if(!stream) {
return 0;
}
if(!http2::check_nv(name, namelen, value, valuelen)) {
return 0;
}
http2::split_add_header(stream->headers, name, namelen, value, valuelen,
flags & NGHTTP2_NV_FLAG_NO_INDEX);
return 0;
}
} // namespace
namespace {
int setup_stream_timeout(Stream *stream)
{
auto hd = stream->handler;
auto evbase = hd->get_sessions()->get_evbase();
stream->rtimer = evtimer_new(evbase, stream_timeout_cb, stream);
if(!stream->rtimer) {
return -1;
}
stream->wtimer = evtimer_new(evbase, stream_timeout_cb, stream);
if(!stream->wtimer) {
return -1;
}
return 0;
}
} // namespace
namespace {
int on_begin_headers_callback(nghttp2_session *session,
const nghttp2_frame *frame,
void *user_data)
{
auto hd = static_cast<Http2Handler*>(user_data);
if(frame->hd.type != NGHTTP2_HEADERS ||
frame->headers.cat != NGHTTP2_HCAT_REQUEST) {
return 0;
}
auto stream = util::make_unique<Stream>(hd, frame->hd.stream_id);
if(setup_stream_timeout(stream.get()) != 0) {
hd->submit_rst_stream(stream.get(), NGHTTP2_INTERNAL_ERROR);
return 0;
}
add_stream_read_timeout(stream.get());
hd->add_stream(frame->hd.stream_id, std::move(stream));
return 0;
}
} // namespace
namespace {
int hd_on_frame_recv_callback
(nghttp2_session *session, const nghttp2_frame *frame, void *user_data)
{
auto hd = static_cast<Http2Handler*>(user_data);
if(hd->get_config()->verbose) {
print_session_id(hd->session_id());
verbose_on_frame_recv_callback(session, frame, user_data);
}
switch(frame->hd.type) {
case NGHTTP2_DATA: {
// TODO Handle POST
auto stream = hd->get_stream(frame->hd.stream_id);
if(!stream) {
return 0;
}
if(frame->hd.flags & NGHTTP2_FLAG_END_STREAM) {
remove_stream_read_timeout(stream);
prepare_response(stream, hd);
} else {
add_stream_read_timeout(stream);
}
break;
}
case NGHTTP2_HEADERS: {
auto stream = hd->get_stream(frame->hd.stream_id);
if(!stream) {
return 0;
}
if(frame->headers.cat == NGHTTP2_HCAT_REQUEST) {
http2::normalize_headers(stream->headers);
if(!http2::check_http2_headers(stream->headers)) {
hd->submit_rst_stream(stream, NGHTTP2_PROTOCOL_ERROR);
return 0;
}
for(size_t i = 0; REQUIRED_HEADERS[i]; ++i) {
if(!http2::get_unique_header(stream->headers, REQUIRED_HEADERS[i])) {
hd->submit_rst_stream(stream, NGHTTP2_PROTOCOL_ERROR);
return 0;
}
}
// intermediary translating from HTTP/1 request to HTTP/2 may
// not produce :authority header field. In this case, it should
// provide host HTTP/1.1 header field.
if(!http2::get_unique_header(stream->headers, ":authority") &&
!http2::get_unique_header(stream->headers, "host")) {
hd->submit_rst_stream(stream, NGHTTP2_PROTOCOL_ERROR);
return 0;
}
}
if(frame->hd.flags & NGHTTP2_FLAG_END_STREAM) {
remove_stream_read_timeout(stream);
prepare_response(stream, hd);
} else {
add_stream_read_timeout(stream);
}
break;
}
case NGHTTP2_SETTINGS:
if(frame->hd.flags & NGHTTP2_FLAG_ACK) {
hd->remove_settings_timer();
}
break;
case NGHTTP2_PUSH_PROMISE:
nghttp2_submit_rst_stream(session, NGHTTP2_FLAG_NONE,
frame->push_promise.promised_stream_id,
NGHTTP2_REFUSED_STREAM);
break;
default:
break;
}
return 0;
}
} // namespace
namespace {
int hd_on_frame_send_callback
(nghttp2_session *session, const nghttp2_frame *frame,
void *user_data)
{
auto hd = static_cast<Http2Handler*>(user_data);
if(hd->get_config()->verbose) {
print_session_id(hd->session_id());
verbose_on_frame_send_callback(session, frame, user_data);
}
switch(frame->hd.type) {
case NGHTTP2_DATA:
case NGHTTP2_HEADERS: {
auto stream = hd->get_stream(frame->hd.stream_id);
if(!stream) {
return 0;
}
if(frame->hd.flags & NGHTTP2_FLAG_END_STREAM) {
remove_stream_write_timeout(stream);
} else if(nghttp2_session_get_stream_remote_window_size
(session, frame->hd.stream_id) == 0) {
// If stream is blocked by flow control, enable write timeout.
add_stream_read_timeout_if_pending(stream);
add_stream_write_timeout(stream);
} else {
add_stream_read_timeout_if_pending(stream);
remove_stream_write_timeout(stream);
}
break;
}
case NGHTTP2_PUSH_PROMISE: {
auto promised_stream_id = frame->push_promise.promised_stream_id;
auto promised_stream = hd->get_stream(promised_stream_id);
auto stream = hd->get_stream(frame->hd.stream_id);
if(!stream || !promised_stream) {
return 0;
}
if(setup_stream_timeout(promised_stream) != 0) {
nghttp2_submit_rst_stream(session, NGHTTP2_FLAG_NONE,
promised_stream_id, NGHTTP2_INTERNAL_ERROR);
return 0;
}
add_stream_read_timeout_if_pending(stream);
add_stream_write_timeout(stream);
prepare_response(promised_stream, hd, /*allow_push */ false);
}
}
return 0;
}
} // namespace
namespace {
ssize_t select_padding_callback
(nghttp2_session *session, const nghttp2_frame *frame, size_t max_payload,
void *user_data)
{
auto hd = static_cast<Http2Handler*>(user_data);
return std::min(max_payload, frame->hd.length + hd->get_config()->padding);
}
} // namespace
namespace {
int on_data_chunk_recv_callback
(nghttp2_session *session, uint8_t flags, int32_t stream_id,
const uint8_t *data, size_t len, void *user_data)
{
auto hd = static_cast<Http2Handler*>(user_data);
auto stream = hd->get_stream(stream_id);
if(!stream) {
return 0;
}
// TODO Handle POST
add_stream_read_timeout(stream);
return 0;
}
} // namespace
namespace {
int on_stream_close_callback
(nghttp2_session *session, int32_t stream_id, nghttp2_error_code error_code,
void *user_data)
{
auto hd = static_cast<Http2Handler*>(user_data);
hd->remove_stream(stream_id);
if(hd->get_config()->verbose) {
print_session_id(hd->session_id());
print_timer();
printf(" stream_id=%d closed\n", stream_id);
fflush(stdout);
}
return 0;
}
} // namespace
namespace {
void fill_callback(nghttp2_session_callbacks& callbacks, const Config *config)
{
memset(&callbacks, 0, sizeof(nghttp2_session_callbacks));
callbacks.on_stream_close_callback = on_stream_close_callback;
callbacks.on_frame_recv_callback = hd_on_frame_recv_callback;
callbacks.on_frame_send_callback = hd_on_frame_send_callback;
if(config->verbose) {
callbacks.on_invalid_frame_recv_callback =
verbose_on_invalid_frame_recv_callback;
callbacks.on_unknown_frame_recv_callback =
verbose_on_unknown_frame_recv_callback;
}
callbacks.on_data_chunk_recv_callback = on_data_chunk_recv_callback;
callbacks.on_header_callback = on_header_callback;
callbacks.on_begin_headers_callback = on_begin_headers_callback;
if(config->padding) {
callbacks.select_padding_callback = select_padding_callback;
}
}
} // namespace
struct ClientInfo {
int fd;
};
namespace {
void worker_readcb(bufferevent *bev, void *arg)
{
auto sessions = static_cast<Sessions*>(arg);
auto input = bufferevent_get_input(bev);
while(evbuffer_get_length(input) >= sizeof(ClientInfo)) {
ClientInfo client;
evbuffer_remove(input, &client, sizeof(client));
sessions->accept_connection(client.fd);
}
}
} // namespace
namespace {
void run_worker(int thread_id, int fd, SSL_CTX *ssl_ctx, const Config *config)
{
auto evbase = event_base_new();
auto bev = bufferevent_socket_new(evbase, fd,
BEV_OPT_DEFER_CALLBACKS |
BEV_OPT_CLOSE_ON_FREE);
auto sessions = Sessions(evbase, config, ssl_ctx);
bufferevent_enable(bev, EV_READ);
bufferevent_setcb(bev, worker_readcb, nullptr, nullptr, &sessions);
event_base_loop(evbase, 0);
}
} // namespace
class ListenEventHandler {
public:
ListenEventHandler(Sessions *sessions, const Config *config)
: sessions_(sessions),
config_(config),
next_worker_(0)
{
int rv;
if(config_->num_worker == 1) {
return;
}
for(size_t i = 0; i < config_->num_worker; ++i) {
if(config_->verbose) {
std::cerr << "spawning thread #" << i << std::endl;
}
int socks[2];
rv = socketpair(AF_UNIX, SOCK_STREAM, 0, socks);
if(rv == -1) {
std::cerr << "socketpair() failed: errno=" << errno << std::endl;
assert(0);
}
evutil_make_socket_nonblocking(socks[0]);
evutil_make_socket_nonblocking(socks[1]);
auto bev = bufferevent_socket_new(sessions_->get_evbase(), socks[0],
BEV_OPT_DEFER_CALLBACKS |
BEV_OPT_CLOSE_ON_FREE);
if(!bev) {
std::cerr << "bufferevent_socket_new() failed" << std::endl;
assert(0);
}
workers_.push_back(bev);
auto t = std::thread(run_worker, i, socks[1], sessions_->get_ssl_ctx(),
config_);
t.detach();
}
}
void accept_connection(int fd, sockaddr *addr, int addrlen)
{
if(config_->num_worker == 1) {
sessions_->accept_connection(fd);
return;
}
// Dispatch client to the one of the worker threads, in a round
// robin manner.
auto client = ClientInfo{fd};
bufferevent_write(workers_[next_worker_], &client, sizeof(client));
if(next_worker_ == config_->num_worker - 1) {
next_worker_ = 0;
} else {
++next_worker_;
}
}
private:
// In multi threading mode, this includes bufferevent to dispatch
// client to the worker threads.
std::vector<bufferevent*> workers_;
Sessions *sessions_;
const Config *config_;
// In multi threading mode, this points to the next thread that
// client will be dispatched.
size_t next_worker_;
};
HttpServer::HttpServer(const Config *config)
: config_(config)
{}
namespace {
int next_proto_cb(SSL *s, const unsigned char **data, unsigned int *len,
void *arg)
{
auto next_proto = static_cast<std::pair<unsigned char*, size_t>* >(arg);
*data = next_proto->first;
*len = next_proto->second;
return SSL_TLSEXT_ERR_OK;
}
} // namespace
namespace {
int verify_callback(int preverify_ok, X509_STORE_CTX *ctx)
{
// We don't verify the client certificate. Just request it for the
// testing purpose.
return 1;
}
} // namespace
namespace {
void evlistener_acceptcb(evconnlistener *listener, int fd,
sockaddr *addr, int addrlen, void *arg)
{
auto handler = static_cast<ListenEventHandler*>(arg);
handler->accept_connection(fd, addr, addrlen);
}
} // namespace
namespace {
void evlistener_errorcb(evconnlistener *listener, void *ptr)
{
std::cerr << "Accepting incoming connection failed" << std::endl;
}
} // namespace
namespace {
int start_listen(event_base *evbase, Sessions *sessions, const Config *config)
{
addrinfo hints;
int r;
auto service = util::utos(config->port);
memset(&hints, 0, sizeof(addrinfo));
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
hints.ai_flags = AI_PASSIVE;
#ifdef AI_ADDRCONFIG
hints.ai_flags |= AI_ADDRCONFIG;
#endif // AI_ADDRCONFIG
auto listen_handler_store =
util::make_unique<ListenEventHandler>(sessions, config);
auto listen_handler = listen_handler_store.get();
addrinfo *res, *rp;
r = getaddrinfo(nullptr, service.c_str(), &hints, &res);
if(r != 0) {
std::cerr << "getaddrinfo() failed: " << gai_strerror(r) << std::endl;
return -1;
}
for(rp = res; rp; rp = rp->ai_next) {
int fd = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
if(fd == -1) {
continue;
}
int val = 1;
if(setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &val,
static_cast<socklen_t>(sizeof(val))) == -1) {
close(fd);
continue;
}
evutil_make_socket_nonblocking(fd);
#ifdef IPV6_V6ONLY
if(rp->ai_family == AF_INET6) {
if(setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &val,
static_cast<socklen_t>(sizeof(val))) == -1) {
close(fd);
continue;
}
}
#endif // IPV6_V6ONLY
if(bind(fd, rp->ai_addr, rp->ai_addrlen) == 0) {
auto evlistener = evconnlistener_new
(evbase, evlistener_acceptcb, listen_handler,
LEV_OPT_REUSEABLE | LEV_OPT_CLOSE_ON_FREE, -1, fd);
evconnlistener_set_error_cb(evlistener, evlistener_errorcb);
listen_handler_store.release();
if(config->verbose) {
std::cout << (rp->ai_family == AF_INET ? "IPv4" : "IPv6")
<< ": listen on port "
<< config->port << std::endl;
}
continue;
} else {
std::cerr << strerror(errno) << std::endl;
}
close(fd);
}
freeaddrinfo(res);
return 0;
}
} // namespace
#if OPENSSL_VERSION_NUMBER >= 0x10002000L
namespace {
int alpn_select_proto_cb(SSL* ssl,
const unsigned char **out, unsigned char *outlen,
const unsigned char *in, unsigned int inlen,
void *arg)
{
auto config = static_cast<HttpServer*>(arg)->get_config();
if(config->verbose) {
std::cout << "[ALPN] client offers:" << std::endl;
}
if(config->verbose) {
for(unsigned int i = 0; i < inlen; i += in[i]+1) {
std::cout << " * ";
std::cout.write(reinterpret_cast<const char*>(&in[i+1]), in[i]);
std::cout << std::endl;
}
}
if(nghttp2_select_next_protocol(const_cast<unsigned char**>(out), outlen,
in, inlen) <= 0) {
return SSL_TLSEXT_ERR_NOACK;
}
return SSL_TLSEXT_ERR_OK;
}
} // namespace
#endif // OPENSSL_VERSION_NUMBER >= 0x10002000L
int HttpServer::run()
{
SSL_CTX *ssl_ctx = nullptr;
std::pair<unsigned char*, size_t> next_proto;
unsigned char proto_list[255];
if(!config_->no_tls) {
ssl_ctx = SSL_CTX_new(SSLv23_server_method());
if(!ssl_ctx) {
std::cerr << ERR_error_string(ERR_get_error(), nullptr) << std::endl;
return -1;
}
SSL_CTX_set_options(ssl_ctx,
SSL_OP_ALL | SSL_OP_NO_SSLv2 | SSL_OP_NO_COMPRESSION |
SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION |
SSL_OP_SINGLE_ECDH_USE |
SSL_OP_NO_TICKET |
SSL_OP_CIPHER_SERVER_PREFERENCE);
SSL_CTX_set_mode(ssl_ctx, SSL_MODE_AUTO_RETRY);
SSL_CTX_set_mode(ssl_ctx, SSL_MODE_RELEASE_BUFFERS);
SSL_CTX_set_mode(ssl_ctx, SSL_MODE_ENABLE_PARTIAL_WRITE);
SSL_CTX_set_cipher_list(ssl_ctx, "HIGH:!aNULL:!MD5");
const unsigned char sid_ctx[] = "nghttpd";
SSL_CTX_set_session_id_context(ssl_ctx, sid_ctx, sizeof(sid_ctx)-1);
SSL_CTX_set_session_cache_mode(ssl_ctx, SSL_SESS_CACHE_SERVER);
#ifndef OPENSSL_NO_EC
#if OPENSSL_VERSION_NUMBER >= 0x10002000L
SSL_CTX_set_ecdh_auto(ssl_ctx, 1);
#else // OPENSSL_VERSION_NUBMER < 0x10002000L
// Use P-256, which is sufficiently secure at the time of this
// writing.
auto ecdh = EC_KEY_new_by_curve_name(NID_X9_62_prime256v1);
if(ecdh == nullptr) {
std::cerr << "EC_KEY_new_by_curv_name failed: "
<< ERR_error_string(ERR_get_error(), nullptr);
return -1;
}
SSL_CTX_set_tmp_ecdh(ssl_ctx, ecdh);
EC_KEY_free(ecdh);
#endif // OPENSSL_VERSION_NUBMER < 0x10002000L
#endif // OPENSSL_NO_EC
if(SSL_CTX_use_PrivateKey_file(ssl_ctx,
config_->private_key_file.c_str(),
SSL_FILETYPE_PEM) != 1) {
std::cerr << "SSL_CTX_use_PrivateKey_file failed." << std::endl;
return -1;
}
if(SSL_CTX_use_certificate_chain_file(ssl_ctx,
config_->cert_file.c_str()) != 1) {
std::cerr << "SSL_CTX_use_certificate_file failed." << std::endl;
return -1;
}
if(SSL_CTX_check_private_key(ssl_ctx) != 1) {
std::cerr << "SSL_CTX_check_private_key failed." << std::endl;
return -1;
}
if(config_->verify_client) {
SSL_CTX_set_verify(ssl_ctx,
SSL_VERIFY_PEER | SSL_VERIFY_CLIENT_ONCE |
SSL_VERIFY_FAIL_IF_NO_PEER_CERT,
verify_callback);
}
proto_list[0] = NGHTTP2_PROTO_VERSION_ID_LEN;
memcpy(&proto_list[1], NGHTTP2_PROTO_VERSION_ID,
NGHTTP2_PROTO_VERSION_ID_LEN);
next_proto.first = proto_list;
next_proto.second = proto_list[0] + 1;
SSL_CTX_set_next_protos_advertised_cb(ssl_ctx, next_proto_cb, &next_proto);
#if OPENSSL_VERSION_NUMBER >= 0x10002000L
// ALPN selection callback
SSL_CTX_set_alpn_select_cb(ssl_ctx, alpn_select_proto_cb, this);
#endif // OPENSSL_VERSION_NUMBER >= 0x10002000L
}
auto evcfg = event_config_new();
event_config_set_flag(evcfg, EVENT_BASE_FLAG_NOLOCK);
auto evbase = event_base_new_with_config(evcfg);
Sessions sessions(evbase, config_, ssl_ctx);
if(start_listen(evbase, &sessions, config_) != 0) {
std::cerr << "Could not listen" << std::endl;
return -1;
}
event_base_loop(evbase, 0);
return 0;
}
const Config* HttpServer::get_config() const
{
return config_;
}
} // namespace nghttp2