shrpx: Add --no-via option

If --no-via option is given, shrpx does not append to Via header
field. If Via header field is received, it is left unaltered.

src/shrpx.cc

@@ -351,6 +351,7 @@ void fill_default_config()
   mod_config()->spdy_max_concurrent_streams =
     SPDYLAY_INITIAL_MAX_CONCURRENT_STREAMS;
   mod_config()->add_x_forwarded_for = false;
+  mod_config()->no_via = false;
   mod_config()->accesslog = false;
   set_config_str(&mod_config()->conf_path, "/etc/shrpx/shrpx.conf");
   mod_config()->syslog = false;
@@ -518,6 +519,9 @@ void print_help(std::ostream& out)
       << "    --add-x-forwarded-for\n"
       << "                       Append X-Forwarded-For header field to the\n"
       << "                       downstream request.\n"
+      << "    --no-via           Don't append to Via header field. If Via\n"
+      << "                       header field is received, it is left\n"
+      << "                       unaltered.\n"
       << "    -D, --daemon       Run in a background. If -D is used, the\n"
       << "                       current working directory is changed to '/'.\n"
       << "    --pid-file=<PATH>  Set path to save PID of this program.\n"
@@ -575,6 +579,7 @@ int main(int argc, char **argv)
       {"backend-ipv4", no_argument, &flag, 20 },
       {"backend-ipv6", no_argument, &flag, 21 },
       {"private-key-passwd-file", required_argument, &flag, 22},
+      {"no-via", no_argument, &flag, 23},
       {0, 0, 0, 0 }
     };
     int option_index = 0;
@@ -717,6 +722,10 @@ int main(int argc, char **argv)
         cmdcfgs.push_back(std::make_pair(SHRPX_OPT_PRIVATE_KEY_PASSWD_FILE,
                                          optarg));
         break;
+      case 23:
+        // --no-via
+        cmdcfgs.push_back(std::make_pair(SHRPX_OPT_NO_VIA, "yes"));
+        break;
       default:
         break;
       }

src/shrpx_config.cc

@@ -57,6 +57,7 @@ const char SHRPX_OPT_DAEMON[] = "daemon";
 const char SHRPX_OPT_SPDY_PROXY[] = "spdy-proxy";
 const char SHRPX_OPT_CLIENT_PROXY[] = "client-proxy";
 const char SHRPX_OPT_ADD_X_FORWARDED_FOR[] = "add-x-forwarded-for";
+const char SHRPX_OPT_NO_VIA[] = "no-via";
 const char
 SHRPX_OPT_FRONTEND_SPDY_READ_TIMEOUT[] = "frontend-spdy-read-timeout";
 const char SHRPX_OPT_FRONTEND_READ_TIMEOUT[] = "frontend-read-timeout";
@@ -209,6 +210,8 @@ int parse_config(const char *opt, const char *optarg)
     mod_config()->client_proxy = util::strieq(optarg, "yes");
   } else if(util::strieq(opt, SHRPX_OPT_ADD_X_FORWARDED_FOR)) {
     mod_config()->add_x_forwarded_for = util::strieq(optarg, "yes");
+  } else if(util::strieq(opt, SHRPX_OPT_NO_VIA)) {
+    mod_config()->no_via = util::strieq(optarg, "yes");
   } else if(util::strieq(opt, SHRPX_OPT_FRONTEND_SPDY_READ_TIMEOUT)) {
     timeval tv = {strtol(optarg, 0, 10), 0};
     mod_config()->spdy_upstream_read_timeout = tv;

src/shrpx_config.h

@@ -48,6 +48,7 @@ extern const char SHRPX_OPT_DAEMON[];
 extern const char SHRPX_OPT_SPDY_PROXY[];
 extern const char SHRPX_OPT_CLIENT_PROXY[];
 extern const char SHRPX_OPT_ADD_X_FORWARDED_FOR[];
+extern const char SHRPX_OPT_NO_VIA[];
 extern const char SHRPX_OPT_FRONTEND_SPDY_READ_TIMEOUT[];
 extern const char SHRPX_OPT_FRONTEND_READ_TIMEOUT[];
 extern const char SHRPX_OPT_FRONTEND_WRITE_TIMEOUT[];
@@ -102,6 +103,7 @@ struct Config {
   bool spdy_proxy;
   bool client_proxy;
   bool add_x_forwarded_for;
+  bool no_via;
   bool accesslog;
   size_t spdy_upstream_window_bits;
   size_t spdy_downstream_window_bits;

src/shrpx_http_downstream_connection.cc

@@ -129,7 +129,7 @@ int HttpDownstreamConnection::push_request_headers()
        util::strieq((*i).first.c_str(), "proxy-connection")) {
       continue;
     }
-    if(util::strieq((*i).first.c_str(), "via")) {
+    if(!get_config()->no_via && util::strieq((*i).first.c_str(), "via")) {
       via_value = (*i).second;
       continue;
     }
@@ -171,14 +171,16 @@ int HttpDownstreamConnection::push_request_headers()
     }
     hdrs += "\r\n";
   }
-  hdrs += "Via: ";
+  if(!get_config()->no_via) {
-  hdrs += via_value;
+    hdrs += "Via: ";
-  if(!via_value.empty()) {
+    if(!via_value.empty()) {
-    hdrs += ", ";
+      hdrs += via_value;
+      hdrs += ", ";
+    }
+    hdrs += http::create_via_header_value(downstream_->get_request_major(),
+                                          downstream_->get_request_minor());
+    hdrs += "\r\n";
   }
-  hdrs += http::create_via_header_value(downstream_->get_request_major(),
-                                        downstream_->get_request_minor());
-  hdrs += "\r\n";
 
   hdrs += "\r\n";
   if(ENABLE_LOG) {

src/shrpx_https_upstream.cc

@@ -604,7 +604,8 @@ int HttpsUpstream::on_downstream_header_complete(Downstream *downstream)
        util::strieq((*i).first.c_str(), "connection") ||
        util:: strieq((*i).first.c_str(), "proxy-connection")) {
       // These are ignored
-    } else if(util::strieq((*i).first.c_str(), "via")) {
+    } else if(!get_config()->no_via &&
+              util::strieq((*i).first.c_str(), "via")) {
       via_value = (*i).second;
     } else {
       hdrs += (*i).first;
@@ -627,15 +628,17 @@ int HttpsUpstream::on_downstream_header_complete(Downstream *downstream)
   } else {
     hdrs += "Connection: close\r\n";
   }
-
+  if(!get_config()->no_via) {
-  hdrs += "Via: ";
+    hdrs += "Via: ";
-  hdrs += via_value;
+    if(!via_value.empty()) {
-  if(!via_value.empty()) {
+      hdrs += via_value;
-    hdrs += ", ";
+      hdrs += ", ";
+    }
+    hdrs += http::create_via_header_value
+      (downstream->get_response_major(), downstream->get_response_minor());
+    hdrs += "\r\n";
   }
-  hdrs += http::create_via_header_value
+
-    (downstream->get_response_major(), downstream->get_response_minor());
-  hdrs += "\r\n";
   hdrs += "\r\n";
   if(ENABLE_LOG) {
     const char *hdrp;

src/shrpx_spdy_downstream_connection.cc

@@ -245,7 +245,8 @@ int SpdyDownstreamConnection::push_request_headers()
               util::strieq((*i).first.c_str(), "connection") ||
               util:: strieq((*i).first.c_str(), "proxy-connection")) {
       // These are ignored
-    } else if(util::strieq((*i).first.c_str(), "via")) {
+    } else if(!get_config()->no_via &&
+              util::strieq((*i).first.c_str(), "via")) {
       via_value = (*i).second;
     } else if(util::strieq((*i).first.c_str(), "x-forwarded-for")) {
       xff_value = (*i).second;
@@ -282,14 +283,15 @@ int SpdyDownstreamConnection::push_request_headers()
     nv[hdidx++] = "x-forwarded-proto";
     nv[hdidx++] = "http";
   }
-
+  if(!get_config()->no_via) {
-  if(!via_value.empty()) {
+    if(!via_value.empty()) {
-    via_value += ", ";
+      via_value += ", ";
+    }
+    via_value += http::create_via_header_value
+      (downstream_->get_request_major(), downstream_->get_request_minor());
+    nv[hdidx++] = "via";
+    nv[hdidx++] = via_value.c_str();
   }
-  via_value += http::create_via_header_value(downstream_->get_request_major(),
-                                             downstream_->get_request_minor());
-  nv[hdidx++] = "via";
-  nv[hdidx++] = via_value.c_str();
   nv[hdidx++] = 0;
   if(ENABLE_LOG) {
     std::stringstream ss;

src/shrpx_spdy_upstream.cc

@@ -755,20 +755,23 @@ int SpdyUpstream::on_downstream_header_complete(Downstream *downstream)
        util::strieq((*i).first.c_str(), "connection") ||
        util:: strieq((*i).first.c_str(), "proxy-connection")) {
       // These are ignored
-    } else if(util::strieq((*i).first.c_str(), "via")) {
+    } else if(!get_config()->no_via &&
+              util::strieq((*i).first.c_str(), "via")) {
       via_value = (*i).second;
     } else {
       nv[hdidx++] = (*i).first.c_str();
       nv[hdidx++] = (*i).second.c_str();
     }
   }
-  if(!via_value.empty()) {
+  if(!get_config()->no_via) {
-    via_value += ", ";
+    if(!via_value.empty()) {
+      via_value += ", ";
+    }
+    via_value += http::create_via_header_value
+      (downstream->get_response_major(), downstream->get_response_minor());
+    nv[hdidx++] = "via";
+    nv[hdidx++] = via_value.c_str();
   }
-  via_value += http::create_via_header_value(downstream->get_response_major(),
-                                             downstream->get_response_minor());
-  nv[hdidx++] = "via";
-  nv[hdidx++] = via_value.c_str();
   nv[hdidx++] = 0;
   if(ENABLE_LOG) {
     std::stringstream ss;