Merge branch 'master' into http2-debug-state-api

AUTHORS

@@ -71,6 +71,7 @@ Tomasz Buchert
 Vernon Tang
 Viacheslav Biriukov
 Viktor Szépe
+Wenfeng Liu
 Xiaoguang Sun
 Zhuoyun Wei
 acesso

CMakeLists.txt

@@ -24,7 +24,7 @@
 
 cmake_minimum_required(VERSION 3.0)
 # XXX using 1.8.90 instead of 1.9.0-DEV
-project(nghttp2 VERSION 1.13.90)
+project(nghttp2 VERSION 1.14.90)
 
 # See versioning rule:
 #  http://www.gnu.org/software/libtool/manual/html_node/Updating-version-info.html

author.py

@@ -0,0 +1,52 @@
+#!/usr/bin/env python
+
+# script to extract commit author's name from standard input.  The
+# input should be <AUTHOR>:<EMAIL>, one per line.
+# This script expects the input is created by git-log command:
+#
+#   git log --format=%aN:%aE
+#
+# This script removes duplicates based on email address, breaking a
+# tie with longer author name.  Among the all author names extract the
+# previous step, we remove duplicate by case-insensitive match.
+#
+# So we can do this in one line:
+#
+#   git log --format=%aN:%aE | sort | uniq | ./author.py > authors
+
+import sys
+
+edict = {}
+
+for line in sys.stdin:
+    author, email = line.strip().split(':', 1)
+    if email in edict:
+        an = edict[email]
+        if len(an) < len(author) or an > author:
+            sys.stderr.write(
+                'eliminated {} in favor of {}\n'.format(an, author))
+            edict[email] = author
+        else:
+            sys.stderr.write(
+                'eliminated {} in favor of {}\n'.format(author, an))
+    else:
+        edict[email] = author
+
+names = list(sorted(edict.values()))
+
+ndict = {}
+
+for name in names:
+    lowname = name.lower()
+    if lowname in ndict:
+        an = ndict[lowname]
+        if an > name:
+            sys.stderr.write('eliminated {} in favor of {}\n'.format(an, name))
+            ndict[lowname] = name
+        else:
+            sys.stderr.write('eliminated {} in favor of {}\n'.format(name, an))
+    else:
+        ndict[lowname] = name
+
+for name in sorted(ndict.values()):
+    print name

configure.ac

@@ -25,7 +25,7 @@ dnl Do not change user variables!
 dnl http://www.gnu.org/software/automake/manual/html_node/Flag-Variables-Ordering.html
 
 AC_PREREQ(2.61)
-AC_INIT([nghttp2], [1.14.0-DEV], [t-tujikawa@users.sourceforge.net])
+AC_INIT([nghttp2], [1.15.0-DEV], [t-tujikawa@users.sourceforge.net])
 AC_CONFIG_AUX_DIR([.])
 AC_CONFIG_MACRO_DIR([m4])
 AC_CONFIG_HEADERS([config.h])
@@ -44,9 +44,9 @@ m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])])
 
 dnl See versioning rule:
 dnl  http://www.gnu.org/software/libtool/manual/html_node/Updating-version-info.html
-AC_SUBST(LT_CURRENT, 23)
+AC_SUBST(LT_CURRENT, 24)
 AC_SUBST(LT_REVISION, 0)
-AC_SUBST(LT_AGE, 9)
+AC_SUBST(LT_AGE, 10)
 
 major=`echo $PACKAGE_VERSION |cut -d. -f1 | sed -e "s/[^0-9]//g"`
 minor=`echo $PACKAGE_VERSION |cut -d. -f2 | sed -e "s/[^0-9]//g"`

doc/Makefile.am

@@ -37,6 +37,7 @@ APIDOCS= \
 	nghttp2_hd_deflate_get_num_table_entries.rst \
 	nghttp2_hd_deflate_get_table_entry.rst \
 	nghttp2_hd_deflate_hd.rst \
+	nghttp2_hd_deflate_hd_vec.rst \
 	nghttp2_hd_deflate_new.rst \
 	nghttp2_hd_deflate_new2.rst \
 	nghttp2_hd_inflate_change_table_size.rst \

doc/h2load.1

@@ -1,6 +1,6 @@
 .\" Man page generated from reStructuredText.
 .
-.TH "H2LOAD" "1" "Jul 31, 2016" "1.14.0-DEV" "nghttp2"
+.TH "H2LOAD" "1" "Aug 25, 2016" "1.14.0" "nghttp2"
 .SH NAME
 h2load \- HTTP/2 benchmarking tool
 .

doc/nghttp.1

@@ -1,6 +1,6 @@
 .\" Man page generated from reStructuredText.
 .
-.TH "NGHTTP" "1" "Jul 31, 2016" "1.14.0-DEV" "nghttp2"
+.TH "NGHTTP" "1" "Aug 25, 2016" "1.14.0" "nghttp2"
 .SH NAME
 nghttp \- HTTP/2 client
 .

doc/nghttpd.1

@@ -1,6 +1,6 @@
 .\" Man page generated from reStructuredText.
 .
-.TH "NGHTTPD" "1" "Jul 31, 2016" "1.14.0-DEV" "nghttp2"
+.TH "NGHTTPD" "1" "Aug 25, 2016" "1.14.0" "nghttp2"
 .SH NAME
 nghttpd \- HTTP/2 server
 .

doc/nghttpx.1

@@ -1,6 +1,6 @@
 .\" Man page generated from reStructuredText.
 .
-.TH "NGHTTPX" "1" "Jul 31, 2016" "1.14.0-DEV" "nghttp2"
+.TH "NGHTTPX" "1" "Aug 25, 2016" "1.14.0" "nghttp2"
 .SH NAME
 nghttpx \- HTTP/2 proxy
 .
@@ -938,6 +938,12 @@ $ssl_session_id: session ID for SSL/TLS connection.
 .IP \(bu 2
 $ssl_session_reused:  "r"   if  SSL/TLS   session  was
 reused.  Otherwise, "."
+.IP \(bu 2
+$backend_host:  backend  host   used  to  fulfill  the
+request.  "\-" if backend host is not available.
+.IP \(bu 2
+$backend_port:  backend  port   used  to  fulfill  the
+request.  "\-" if backend host is not available.
 .UNINDENT
 .sp
 The  variable  can  be  enclosed  by  "{"  and  "}"  for

doc/nghttpx.1.rst

@@ -847,6 +847,10 @@ Logging
     * $ssl_session_id: session ID for SSL/TLS connection.
     * $ssl_session_reused:  "r"   if  SSL/TLS   session  was
       reused.  Otherwise, "."
+    * $backend_host:  backend  host   used  to  fulfill  the
+      request.  "-" if backend host is not available.
+    * $backend_port:  backend  port   used  to  fulfill  the
+      request.  "-" if backend host is not available.
 
     The  variable  can  be  enclosed  by  "{"  and  "}"  for
     disambiguation (e.g., ${remote_addr}).

gennghttpxfun.py

@@ -134,6 +134,7 @@ OPTIONS = [
     "backend-http2-settings-timeout",
     "api-max-request-body",
     "backend-max-backoff",
+    "server-name",
 ]
 
 LOGVARS = [

lib/nghttp2_hd.c

@@ -768,14 +768,12 @@ static size_t entry_room(size_t namelen, size_t valuelen) {
   return NGHTTP2_HD_ENTRY_OVERHEAD + namelen + valuelen;
 }
 
-static int emit_header(nghttp2_hd_nv *nv_out, nghttp2_hd_nv *nv) {
+static void emit_header(nghttp2_hd_nv *nv_out, nghttp2_hd_nv *nv) {
   DEBUGF(fprintf(stderr, "inflatehd: header emission: %s: %s\n", nv->name->base,
                  nv->value->base));
   /* ent->ref may be 0. This happens if the encoder emits literal
      block larger than header table capacity with indexing. */
   *nv_out = *nv;
-
-  return 0;
 }
 
 static size_t count_encoded_length(size_t n, size_t prefix) {

src/asio_client_session_impl.cc

@@ -503,7 +503,7 @@ const request *session_impl::submit(boost::system::error_code &ec,
   }
 
   auto nva = std::vector<nghttp2_nv>();
-  nva.reserve(3 + h.size());
+  nva.reserve(4 + h.size());
   nva.push_back(http2::make_nv_ls(":method", method));
   nva.push_back(http2::make_nv_ls(":scheme", uref.scheme));
   nva.push_back(http2::make_nv_ls(":path", path));

src/memchunk.h

@@ -178,6 +178,9 @@ template <typename Memchunk> struct Memchunks {
   }
   size_t append(const std::string &s) { return append(s.c_str(), s.size()); }
   size_t append(const StringRef &s) { return append(s.c_str(), s.size()); }
+  size_t append(const ImmutableString &s) {
+    return append(s.c_str(), s.size());
+  }
   size_t remove(void *dest, size_t count) {
     if (!tail || count == 0) {
       return 0;

src/shrpx.cc

@@ -574,7 +574,7 @@ int create_unix_domain_server_socket(UpstreamAddr &faddr,
                 << (faddr.tls ? ", tls" : "");
     (*found).used = true;
     faddr.fd = (*found).fd;
-    faddr.hostport = "localhost";
+    faddr.hostport = ImmutableString::from_lit("localhost");
 
     return 0;
   }
@@ -639,7 +639,7 @@ int create_unix_domain_server_socket(UpstreamAddr &faddr,
               << (faddr.tls ? ", tls" : "");
 
   faddr.fd = fd;
-  faddr.hostport = "localhost";
+  faddr.hostport = ImmutableString::from_lit("localhost");
 
   return 0;
 }
@@ -791,7 +791,8 @@ int create_tcp_server_socket(UpstreamAddr &faddr,
   }
 
   faddr.fd = fd;
-  faddr.hostport = util::make_http_hostport(StringRef{host.data()}, faddr.port);
+  faddr.hostport = ImmutableString{
+      util::make_http_hostport(StringRef{host.data()}, faddr.port)};
 
   LOG(NOTICE) << "Listening on " << faddr.hostport
               << (faddr.tls ? ", tls" : "");
@@ -855,7 +856,7 @@ get_inherited_addr_from_config(const Config *config) {
       continue;
     }
 
-    iaddr.host = host.data();
+    iaddr.host = ImmutableString{host.data()};
   }
 
   return iaddrs;
@@ -947,7 +948,7 @@ std::vector<InheritedAddr> get_inherited_addr_from_env() {
       }
 
       InheritedAddr addr{};
-      addr.host = path;
+      addr.host = ImmutableString{path};
       addr.host_unix = true;
       addr.fd = static_cast<int>(fd);
       iaddrs.push_back(std::move(addr));
@@ -1001,7 +1002,7 @@ std::vector<InheritedAddr> get_inherited_addr_from_env() {
       }
 
       InheritedAddr addr{};
-      addr.host = host.data();
+      addr.host = ImmutableString{host.data()};
       addr.port = static_cast<uint16_t>(port);
       addr.fd = static_cast<int>(fd);
       iaddrs.push_back(std::move(addr));
@@ -1272,10 +1273,8 @@ constexpr auto DEFAULT_ACCESSLOG_FORMAT = StringRef::from_lit(
 
 namespace {
 void fill_default_config(Config *config) {
-  *config = {};
-
   config->num_worker = 1;
-  config->conf_path = "/etc/nghttpx/nghttpx.conf";
+  config->conf_path = ImmutableString::from_lit("/etc/nghttpx/nghttpx.conf");
   config->pid = getpid();
 
   if (ev_supported_backends() & ~ev_recommended_backends() & EVBACKEND_KQUEUE) {
@@ -1306,7 +1305,8 @@ void fill_default_config(Config *config) {
     auto &ocspconf = tlsconf.ocsp;
     // ocsp update interval = 14400 secs = 4 hours, borrowed from h2o
     ocspconf.update_interval = 4_h;
-    ocspconf.fetch_ocsp_response_file = PKGDATADIR "/fetch-ocsp-response";
+    ocspconf.fetch_ocsp_response_file =
+        ImmutableString::from_lit(PKGDATADIR "/fetch-ocsp-response");
   }
 
   {
@@ -1319,7 +1319,7 @@ void fill_default_config(Config *config) {
 
   auto &httpconf = config->http;
   httpconf.server_name =
-      StringRef::from_lit("nghttpx nghttp2/" NGHTTP2_VERSION);
+      ImmutableString::from_lit("nghttpx nghttp2/" NGHTTP2_VERSION);
   httpconf.no_host_rewrite = true;
   httpconf.request_header_field_buffer = 64_k;
   httpconf.max_request_header_fields = 100;
@@ -1377,7 +1377,7 @@ void fill_default_config(Config *config) {
     accessconf.format = parse_log_format(DEFAULT_ACCESSLOG_FORMAT);
 
     auto &errorconf = loggingconf.error;
-    errorconf.file = "/dev/stderr";
+    errorconf.file = ImmutableString::from_lit("/dev/stderr");
   }
 
   loggingconf.syslog_facility = LOG_DAEMON;
@@ -2205,6 +2205,9 @@ HTTP:
               599.  If "*"  is used instead of <CODE>,  it matches all
               HTTP  status  code.  If  error  status  code comes  from
               backend server, the custom error pages are not used.
+  --server-name=<NAME>
+              Change server response header field value to <NAME>.
+              Default: )" << get_config()->http.server_name << R"(
 
 API:
   --api-max-request-body=<SIZE>
@@ -2396,7 +2399,7 @@ int process_options(Config *config,
 
   if (listenerconf.addrs.empty()) {
     UpstreamAddr addr{};
-    addr.host = "*";
+    addr.host = ImmutableString::from_lit("*");
     addr.port = 3000;
     addr.tls = true;
     addr.family = AF_INET;
@@ -2833,6 +2836,7 @@ int main(int argc, char **argv) {
          &flag, 125},
         {SHRPX_OPT_API_MAX_REQUEST_BODY.c_str(), required_argument, &flag, 126},
         {SHRPX_OPT_BACKEND_MAX_BACKOFF.c_str(), required_argument, &flag, 127},
+        {SHRPX_OPT_SERVER_NAME.c_str(), required_argument, &flag, 128},
         {nullptr, 0, nullptr, 0}};
 
     int option_index = 0;
@@ -2935,7 +2939,7 @@ int main(int argc, char **argv) {
         break;
       case 12:
         // --conf
-        mod_config()->conf_path = optarg;
+        mod_config()->conf_path = ImmutableString{optarg};
         break;
       case 14:
         // --syslog-facility
@@ -3430,6 +3434,10 @@ int main(int argc, char **argv) {
         // --backend-max-backoff
         cmdcfgs.emplace_back(SHRPX_OPT_BACKEND_MAX_BACKOFF, StringRef{optarg});
         break;
+      case 128:
+        // --server-name
+        cmdcfgs.emplace_back(SHRPX_OPT_SERVER_NAME, StringRef{optarg});
+        break;
       default:
         break;
       }

src/shrpx_config.cc

@@ -1127,6 +1127,11 @@ int option_lookup_token(const char *name, size_t namelen) {
     break;
   case 11:
     switch (name[10]) {
+    case 'e':
+      if (util::strieq_l("server-nam", name, 10)) {
+        return SHRPX_OPTID_SERVER_NAME;
+      }
+      break;
     case 's':
       if (util::strieq_l("backend-tl", name, 10)) {
         return SHRPX_OPTID_BACKEND_TLS;
@@ -2027,7 +2032,7 @@ int parse_config(Config *config, int optid, const StringRef &opt,
                  << strerror(errno);
       return -1;
     }
-    config->user = pwd->pw_name;
+    config->user = ImmutableString{pwd->pw_name};
     config->uid = pwd->pw_uid;
     config->gid = pwd->pw_gid;
 
@@ -2044,7 +2049,7 @@ int parse_config(Config *config, int optid, const StringRef &opt,
       LOG(ERROR) << opt << ": Couldn't read key file's passwd from " << optarg;
       return -1;
     }
-    config->tls.private_key_passwd = passwd;
+    config->tls.private_key_passwd = ImmutableString{passwd};
 
     return 0;
   }
@@ -2479,14 +2484,14 @@ int parse_config(Config *config, int optid, const StringRef &opt,
     switch (optid) {
     case SHRPX_OPTID_TLS_SESSION_CACHE_MEMCACHED: {
       auto &memcachedconf = config->tls.session_cache.memcached;
-      memcachedconf.host = host;
+      memcachedconf.host = ImmutableString{host};
       memcachedconf.port = port;
       memcachedconf.tls = params.tls;
       break;
     }
     case SHRPX_OPTID_TLS_TICKET_KEY_MEMCACHED: {
       auto &memcachedconf = config->tls.ticket.memcached;
-      memcachedconf.host = host;
+      memcachedconf.host = ImmutableString{host};
       memcachedconf.port = port;
       memcachedconf.tls = params.tls;
       break;
@@ -2673,6 +2678,11 @@ int parse_config(Config *config, int optid, const StringRef &opt,
   case SHRPX_OPTID_BACKEND_MAX_BACKOFF:
     return parse_duration(&config->conn.downstream->timeout.max_backoff, opt,
                           optarg);
+  case SHRPX_OPTID_SERVER_NAME:
+    config->http.server_name =
+        ImmutableString{std::begin(optarg), std::end(optarg)};
+
+    return 0;
   case SHRPX_OPTID_CONF:
     LOG(WARN) << "conf: ignored";
 
@@ -2948,7 +2958,7 @@ int configure_downstream_group(Config *config, bool http2_proxy,
     auto &sni = tlsconf.backend_sni_name;
     for (auto &addr_group : addr_groups) {
       for (auto &addr : addr_group.addrs) {
-        addr.sni = sni;
+        addr.sni = ImmutableString{sni};
       }
     }
   }
@@ -2995,7 +3005,7 @@ int configure_downstream_group(Config *config, bool http2_proxy,
         // for AF_UNIX socket, we use "localhost" as host for backend
         // hostport.  This is used as Host header field to backend and
         // not going to be passed to any syscalls.
-        addr.hostport = "localhost";
+        addr.hostport = ImmutableString::from_lit("localhost");
 
         auto path = addr.host.c_str();
         auto pathlen = addr.host.size();

src/shrpx_config.h

@@ -284,6 +284,7 @@ constexpr auto SHRPX_OPT_API_MAX_REQUEST_BODY =
     StringRef::from_lit("api-max-request-body");
 constexpr auto SHRPX_OPT_BACKEND_MAX_BACKOFF =
     StringRef::from_lit("backend-max-backoff");
+constexpr auto SHRPX_OPT_SERVER_NAME = StringRef::from_lit("server-name");
 
 constexpr size_t SHRPX_OBFUSCATED_NODE_LENGTH = 8;
 
@@ -552,7 +553,7 @@ struct HttpConfig {
   std::vector<ErrorPage> error_pages;
   Headers add_request_headers;
   Headers add_response_headers;
-  StringRef server_name;
+  ImmutableString server_name;
   size_t request_header_field_buffer;
   size_t max_request_header_fields;
   size_t response_header_field_buffer;
@@ -706,8 +707,14 @@ struct APIConfig {
 };
 
 struct Config {
+  Config() = default;
   ~Config();
 
+  Config(Config &&) = delete;
+  Config(const Config &&) = delete;
+  Config &operator=(Config &&) = delete;
+  Config &operator=(const Config &&) = delete;
+
   HttpProxy downstream_http_proxy;
   HttpConfig http;
   Http2Config http2;
@@ -837,6 +844,7 @@ enum {
   SHRPX_OPTID_REQUEST_HEADER_FIELD_BUFFER,
   SHRPX_OPTID_RESPONSE_HEADER_FIELD_BUFFER,
   SHRPX_OPTID_RLIMIT_NOFILE,
+  SHRPX_OPTID_SERVER_NAME,
   SHRPX_OPTID_STREAM_READ_TIMEOUT,
   SHRPX_OPTID_STREAM_WRITE_TIMEOUT,
   SHRPX_OPTID_STRIP_INCOMING_FORWARDED,

src/shrpx_http.cc

@@ -51,7 +51,7 @@ StringRef create_error_html(BlockAllocator &balloc, unsigned int http_status) {
   return concat_string_ref(
       balloc, StringRef::from_lit(R"(<!DOCTYPE html><html lang="en"><title>)"),
       status_string, StringRef::from_lit("</title><body><h1>"), status_string,
-      StringRef::from_lit("</h1><footer>"), server_name,
+      StringRef::from_lit("</h1><footer>"), StringRef{server_name},
       StringRef::from_lit("</footer></body></html>"));
 }
 

src/shrpx_http2_session.cc

@@ -1806,9 +1806,11 @@ int Http2Session::read_noop(const uint8_t *data, size_t datalen) { return 0; }
 int Http2Session::write_noop() { return 0; }
 
 int Http2Session::connected() {
-  if (!util::check_socket_connected(conn_.fd)) {
+  auto sock_error = util::get_socket_error(conn_.fd);
+  if (sock_error != 0) {
     SSLOG(WARN, this) << "Backend connect failed; addr="
-                      << util::to_numeric_addr(&addr_->addr);
+                      << util::to_numeric_addr(&addr_->addr)
+                      << ": errno=" << sock_error;
 
     downstream_failure(addr_);
 

src/shrpx_http2_upstream.cc

@@ -1307,8 +1307,8 @@ int Http2Upstream::send_reply(Downstream *downstream, const uint8_t *body,
   }
 
   if (!resp.fs.header(http2::HD_SERVER)) {
-    nva.push_back(
+    nva.push_back(http2::make_nv_ls_nocopy(
-        http2::make_nv_ls_nocopy("server", get_config()->http.server_name));
+        "server", StringRef{get_config()->http.server_name}));
   }
 
   for (auto &p : httpconf.add_response_headers) {
@@ -1359,7 +1359,8 @@ int Http2Upstream::error_reply(Downstream *downstream,
   auto nva = std::array<nghttp2_nv, 5>{
       {http2::make_nv_ls_nocopy(":status", response_status),
        http2::make_nv_ll("content-type", "text/html; charset=UTF-8"),
-       http2::make_nv_ls_nocopy("server", get_config()->http.server_name),
+       http2::make_nv_ls_nocopy("server",
+                                StringRef{get_config()->http.server_name}),
        http2::make_nv_ls_nocopy("content-length", content_length),
        http2::make_nv_ls_nocopy("date", date)}};
 
@@ -1506,7 +1507,8 @@ int Http2Upstream::on_downstream_header_complete(Downstream *downstream) {
   http2::copy_headers_to_nva_nocopy(nva, resp.fs.headers());
 
   if (!get_config()->http2_proxy) {
-    nva.push_back(http2::make_nv_ls_nocopy("server", httpconf.server_name));
+    nva.push_back(
+        http2::make_nv_ls_nocopy("server", StringRef{httpconf.server_name}));
   } else {
     auto server = resp.fs.header(http2::HD_SERVER);
     if (server) {

src/shrpx_http_downstream_connection.cc

@@ -994,6 +994,8 @@ int HttpDownstreamConnection::tls_handshake() {
 
   auto &connect_blocker = addr_->connect_blocker;
 
+  do_signal_write_ = &HttpDownstreamConnection::actual_signal_write;
+
   connect_blocker->on_success();
 
   ev_set_cb(&conn_.rt, timeoutcb);
@@ -1141,11 +1143,13 @@ int HttpDownstreamConnection::process_input(const uint8_t *data,
 int HttpDownstreamConnection::connected() {
   auto &connect_blocker = addr_->connect_blocker;
 
-  if (!util::check_socket_connected(conn_.fd)) {
+  auto sock_error = util::get_socket_error(conn_.fd);
+  if (sock_error != 0) {
     conn_.wlimit.stopw();
 
     DCLOG(WARN, this) << "Backend connect failed; addr="
-                      << util::to_numeric_addr(&addr_->addr);
+                      << util::to_numeric_addr(&addr_->addr)
+                      << ": errno=" << sock_error;
 
     downstream_failure(addr_);
 
@@ -1160,8 +1164,6 @@ int HttpDownstreamConnection::connected() {
 
   ev_set_cb(&conn_.wev, writecb);
 
-  do_signal_write_ = &HttpDownstreamConnection::actual_signal_write;
-
   if (conn_.tls.ssl) {
     do_read_ = &HttpDownstreamConnection::tls_handshake;
     do_write_ = &HttpDownstreamConnection::tls_handshake;
@@ -1169,6 +1171,8 @@ int HttpDownstreamConnection::connected() {
     return 0;
   }
 
+  do_signal_write_ = &HttpDownstreamConnection::actual_signal_write;
+
   connect_blocker->on_success();
 
   ev_set_cb(&conn_.rt, timeoutcb);

src/shrpx_live_check.cc

@@ -259,10 +259,12 @@ int LiveCheck::initiate_connection() {
 }
 
 int LiveCheck::connected() {
-  if (!util::check_socket_connected(conn_.fd)) {
+  auto sock_error = util::get_socket_error(conn_.fd);
+  if (sock_error != 0) {
     if (LOG_ENABLED(INFO)) {
       LOG(INFO) << "Backend connect failed; addr="
-                << util::to_numeric_addr(&addr_->addr);
+                << util::to_numeric_addr(&addr_->addr)
+                << ": errno=" << sock_error;
     }
 
     return -1;

src/shrpx_memcached_connection.cc

@@ -203,15 +203,16 @@ int MemcachedConnection::initiate_connection() {
 }
 
 int MemcachedConnection::connected() {
-  if (!util::check_socket_connected(conn_.fd)) {
+  auto sock_error = util::get_socket_error(conn_.fd);
+  if (sock_error != 0) {
+    MCLOG(WARN, this) << "memcached connect failed; addr="
+                      << util::to_numeric_addr(addr_)
+                      << ": errno=" << sock_error;
+
     connect_blocker_.on_failure();
 
     conn_.wlimit.stopw();
 
-    if (LOG_ENABLED(INFO)) {
-      MCLOG(INFO, this) << "memcached connect failed";
-    }
-
     return -1;
   }
 

src/template.h

@@ -255,8 +255,9 @@ public:
   ImmutableString() : len(0), base("") {}
   ImmutableString(const char *s, size_t slen)
       : len(slen), base(copystr(s, s + len)) {}
-  ImmutableString(const char *s) : len(strlen(s)), base(copystr(s, s + len)) {}
+  explicit ImmutableString(const char *s)
-  ImmutableString(const std::string &s)
+      : len(strlen(s)), base(copystr(s, s + len)) {}
+  explicit ImmutableString(const std::string &s)
       : len(s.size()), base(copystr(std::begin(s), std::end(s))) {}
   template <typename InputIt>
   ImmutableString(InputIt first, InputIt last)

src/template_test.cc

@@ -156,7 +156,7 @@ void test_template_string_ref(void) {
   CU_ASSERT(5 == from_lit.size());
 
   // from ImmutableString
-  ImmutableString im = "bravo";
+  auto im = ImmutableString::from_lit("bravo");
 
   StringRef imref(im);
 

src/util.cc

@@ -893,6 +893,16 @@ bool check_socket_connected(int fd) {
   return error == 0;
 }
 
+int get_socket_error(int fd) {
+  int error;
+  socklen_t len = sizeof(error);
+  if (getsockopt(fd, SOL_SOCKET, SO_ERROR, &error, &len) != 0) {
+    return -1;
+  }
+
+  return error;
+}
+
 bool ipv6_numeric_addr(const char *host) {
   uint8_t dst[16];
   return inet_pton(AF_INET6, host, dst) == 1;

src/util.h

@@ -574,6 +574,11 @@ int create_nonblock_socket(int family);
 
 bool check_socket_connected(int fd);
 
+// Returns the error code (errno) by inspecting SO_ERROR of given
+// |fd|.  This function returns the error code if it succeeds, or -1.
+// Returning 0 means no error.
+int get_socket_error(int fd);
+
 // Returns true if |host| is IPv6 numeric address (e.g., ::1)
 bool ipv6_numeric_addr(const char *host);