nghttpx: Add options to dump HTTP headers in HTTP/2.0 upstream

src/http2.cc

@@ -374,6 +374,31 @@ int32_t determine_window_update_transmission(nghttp2_session *session,
   return -1;
 }
 
+void dump_nv(FILE *out, const char **nv)
+{
+  for(size_t i = 0; nv[i]; i += 2) {
+    fwrite(nv[i], strlen(nv[i]), 1, out);
+    fwrite(": ", 2, 1, out);
+    fwrite(nv[i+1], strlen(nv[i+1]), 1, out);
+    fwrite("\n", 1, 1, out);
+  }
+  fwrite("\n", 1, 1, out);
+  fflush(out);
+}
+
+void dump_nv(FILE *out, const nghttp2_nv *nva, size_t nvlen)
+{
+  for(size_t i = 0; i < nvlen; ++i) {
+    auto nv = &nva[i];
+    fwrite(nv->name, nv->namelen, 1, out);
+    fwrite(": ", 2, 1, out);
+    fwrite(nv->value, nv->valuelen, 1, out);
+    fwrite("\n", 1, 1, out);
+  }
+  fwrite("\n", 1, 1, out);
+  fflush(out);
+}
+
 } // namespace http2
 
 } // namespace nghttp2

src/http2.h

@@ -27,6 +27,7 @@
 
 #include "nghttp2_config.h"
 
+#include <cstdio>
 #include <string>
 #include <vector>
 
@@ -120,6 +121,13 @@ void build_http1_headers_from_norm_headers
 int32_t determine_window_update_transmission(nghttp2_session *session,
                                              int32_t stream_id);
 
+// Dumps name/value pairs in |nv| to |out|. The |nv| must be
+// terminated by nullptr.
+void dump_nv(FILE *out, const char **nv);
+
+// Dumps name/value pairs in |nva| to |out|.
+void dump_nv(FILE *out, const nghttp2_nv *nva, size_t nvlen);
+
 } // namespace http2
 
 } // namespace nghttp2

src/shrpx.cc

@@ -420,6 +420,8 @@ void fill_default_config()
   mod_config()->verify_client_cacert = nullptr;
   mod_config()->client_private_key_file = nullptr;
   mod_config()->client_cert_file = nullptr;
+  mod_config()->http2_upstream_dump_request_header = nullptr;
+  mod_config()->http2_upstream_dump_response_header = nullptr;
 }
 } // namespace
 
@@ -675,6 +677,22 @@ void print_help(std::ostream& out)
       << "    --no-via           Don't append to Via header field. If Via\n"
       << "                       header field is received, it is left\n"
       << "                       unaltered.\n"
+      << "    --frontend-http2-dump-request-header=<PATH>\n"
+      << "                       Dumps request headers received by HTTP/2.0\n"
+      << "                       frontend to the file denoted in PATH.\n"
+      << "                       The output is done in HTTP/1 header field\n"
+      << "                       format and each header block is followed by\n"
+      << "                       an empty line.\n"
+      << "                       This option is not thread safe and MUST NOT\n"
+      << "                       be used with option -n=N, where N >= 2.\n"
+      << "    --frontend-http2-dump-response-header=<PATH>\n"
+      << "                       Dumps response headers sent from HTTP/2.0\n"
+      << "                       frontend to the file denoted in PATH.\n"
+      << "                       The output is done in HTTP/1 header field\n"
+      << "                       format and each header block is followed by\n"
+      << "                       an empty line.\n"
+      << "                       This option is not thread safe and MUST NOT\n"
+      << "                       be used with option -n=N, where N >= 2.\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"
@@ -750,6 +768,8 @@ int main(int argc, char **argv)
       {"verify-client-cacert", required_argument, &flag, 40},
       {"client-private-key-file", required_argument, &flag, 41},
       {"client-cert-file", required_argument, &flag, 42},
+      {"frontend-http2-dump-request-header", required_argument, &flag, 43},
+      {"frontend-http2-dump-response-header", required_argument, &flag, 44},
       {nullptr, 0, nullptr, 0 }
     };
 
@@ -972,6 +992,18 @@ int main(int argc, char **argv)
         // --client-cert-file
         cmdcfgs.push_back(std::make_pair(SHRPX_OPT_CLIENT_CERT_FILE, optarg));
         break;
+      case 43:
+        // --frontend-http2-dump-request-header
+        cmdcfgs.push_back(std::make_pair
+                          (SHRPX_OPT_FRONTEND_HTTP2_DUMP_REQUEST_HEADER,
+                           optarg));
+        break;
+      case 44:
+        // --frontend-http2-dump-response-header
+        cmdcfgs.push_back(std::make_pair
+                          (SHRPX_OPT_FRONTEND_HTTP2_DUMP_RESPONSE_HEADER,
+                           optarg));
+        break;
       default:
         break;
       }

src/shrpx_config.cc

@@ -105,6 +105,10 @@ const char SHRPX_OPT_VERIFY_CLIENT[] = "verify-client";
 const char SHRPX_OPT_VERIFY_CLIENT_CACERT[] = "verify-client-cacert";
 const char SHRPX_OPT_CLIENT_PRIVATE_KEY_FILE[] = "client-private-key-file";
 const char SHRPX_OPT_CLIENT_CERT_FILE[] = "client-cert-file";
+const char SHRPX_OPT_FRONTEND_HTTP2_DUMP_REQUEST_HEADER[] =
+  "frontend-http2-dump-request-header";
+const char SHRPX_OPT_FRONTEND_HTTP2_DUMP_RESPONSE_HEADER[] =
+  "frontend-http2-dump-response-header";
 
 namespace {
 Config *config = nullptr;
@@ -172,6 +176,18 @@ bool is_secure(const char *filename)
 }
 } // namespace
 
+namespace {
+FILE* open_file_for_write(const char *filename)
+{
+  auto f = fopen(filename, "wb");
+  if(f == NULL) {
+    LOG(ERROR) << "Failed to open " << filename << " for writing. Cause: "
+               << strerror(errno);
+  }
+  return f;
+}
+} // namespace
+
 std::string read_passwd_from_file(const char *filename)
 {
   std::string line;
@@ -419,6 +435,18 @@ int parse_config(const char *opt, const char *optarg)
     set_config_str(&mod_config()->client_private_key_file, optarg);
   } else if(util::strieq(opt, SHRPX_OPT_CLIENT_CERT_FILE)) {
     set_config_str(&mod_config()->client_cert_file, optarg);
+  } else if(util::strieq(opt, SHRPX_OPT_FRONTEND_HTTP2_DUMP_REQUEST_HEADER)) {
+    auto f = open_file_for_write(optarg);
+    if(f == NULL) {
+      return -1;
+    }
+    mod_config()->http2_upstream_dump_request_header = f;
+  } else if(util::strieq(opt, SHRPX_OPT_FRONTEND_HTTP2_DUMP_RESPONSE_HEADER)) {
+    auto f = open_file_for_write(optarg);
+    if(f == NULL) {
+      return -1;
+    }
+    mod_config()->http2_upstream_dump_response_header = f;
   } else if(util::strieq(opt, "conf")) {
     LOG(WARNING) << "conf is ignored";
   } else {

src/shrpx_config.h

@@ -32,6 +32,7 @@
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
+#include <cstdio>
 #include <vector>
 
 #include <event.h>
@@ -95,6 +96,8 @@ extern const char SHRPX_OPT_VERIFY_CLIENT[];
 extern const char SHRPX_OPT_VERIFY_CLIENT_CACERT[];
 extern const char SHRPX_OPT_CLIENT_PRIVATE_KEY_FILE[];
 extern const char SHRPX_OPT_CLIENT_CERT_FILE[];
+extern const char SHRPX_OPT_FRONTEND_HTTP2_DUMP_REQUEST_HEADER[];
+extern const char SHRPX_OPT_FRONTEND_HTTP2_DUMP_RESPONSE_HEADER[];
 
 union sockaddr_union {
   sockaddr sa;
@@ -195,6 +198,8 @@ struct Config {
   char *verify_client_cacert;
   char *client_private_key_file;
   char *client_cert_file;
+  FILE *http2_upstream_dump_request_header;
+  FILE *http2_upstream_dump_response_header;
 };
 
 const Config* get_config();

src/shrpx_http2_upstream.cc

@@ -254,6 +254,11 @@ int on_frame_recv_callback
                            << "\n" << ss.str();
     }
 
+    if(get_config()->http2_upstream_dump_request_header) {
+      http2::dump_nv(get_config()->http2_upstream_dump_request_header,
+                     frame->headers.nva, frame->headers.nvlen);
+    }
+
     if(!http2::check_http2_headers(nva)) {
       upstream->rst_stream(downstream, NGHTTP2_PROTOCOL_ERROR);
       return 0;
@@ -968,6 +973,12 @@ int Http2Upstream::on_downstream_header_complete(Downstream *downstream)
                      << downstream->get_stream_id() << "\n"
                      << ss.str();
   }
+
+  if(get_config()->http2_upstream_dump_response_header) {
+    http2::dump_nv(get_config()->http2_upstream_dump_response_header,
+                   nv.data());
+  }
+
   nghttp2_data_provider data_prd;
   data_prd.source.ptr = downstream;
   data_prd.read_callback = downstream_data_read_callback;