1 files changed, 238 insertions, 0 deletions
diff --git a/src/shrpx_mruby.cc b/src/shrpx_mruby.cc
new file mode 100644
index 0000000..b5c6ed3
--- /dev/null
+++ b/src/shrpx_mruby.cc
@@ -0,0 +1,238 @@
+/*
+ * nghttp2 - HTTP/2 C Library
+ *
+ * Copyright (c) 2015 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 "shrpx_mruby.h"
+
+#include <mruby/compile.h>
+#include <mruby/string.h>
+
+#include "shrpx_downstream.h"
+#include "shrpx_config.h"
+#include "shrpx_mruby_module.h"
+#include "shrpx_downstream_connection.h"
+#include "shrpx_log.h"
+
+namespace shrpx {
+
+namespace mruby {
+
+MRubyContext::MRubyContext(mrb_state *mrb, mrb_value app, mrb_value env)
+    : mrb_(mrb), app_(std::move(app)), env_(std::move(env)) {}
+
+MRubyContext::~MRubyContext() {
+  if (mrb_) {
+    mrb_close(mrb_);
+  }
+}
+
+int MRubyContext::run_app(Downstream *downstream, int phase) {
+  if (!mrb_) {
+    return 0;
+  }
+
+  MRubyAssocData data{downstream, phase};
+
+  mrb_->ud = &data;
+
+  int rv = 0;
+  auto ai = mrb_gc_arena_save(mrb_);
+  auto ai_d = defer([ai, this]() { mrb_gc_arena_restore(mrb_, ai); });
+
+  const char *method;
+  switch (phase) {
+  case PHASE_REQUEST:
+    if (!mrb_respond_to(mrb_, app_, mrb_intern_lit(mrb_, "on_req"))) {
+      return 0;
+    }
+    method = "on_req";
+    break;
+  case PHASE_RESPONSE:
+    if (!mrb_respond_to(mrb_, app_, mrb_intern_lit(mrb_, "on_resp"))) {
+      return 0;
+    }
+    method = "on_resp";
+    break;
+  default:
+    assert(0);
+    abort();
+  }
+
+  auto res = mrb_funcall(mrb_, app_, method, 1, env_);
+  (void)res;
+
+  if (mrb_->exc) {
+    // If response has been committed, ignore error
+    if (downstream->get_response_state() != DownstreamState::MSG_COMPLETE) {
+      rv = -1;
+    }
+
+    auto exc = mrb_obj_value(mrb_->exc);
+    auto inspect = mrb_inspect(mrb_, exc);
+
+    LOG(ERROR) << "Exception caught while executing mruby code: "
+               << mrb_str_to_cstr(mrb_, inspect);
+  }
+
+  mrb_->ud = nullptr;
+
+  return rv;
+}
+
+int MRubyContext::run_on_request_proc(Downstream *downstream) {
+  return run_app(downstream, PHASE_REQUEST);
+}
+
+int MRubyContext::run_on_response_proc(Downstream *downstream) {
+  return run_app(downstream, PHASE_RESPONSE);
+}
+
+void MRubyContext::delete_downstream(Downstream *downstream) {
+  if (!mrb_) {
+    return;
+  }
+  delete_downstream_from_module(mrb_, downstream);
+}
+
+namespace {
+mrb_value instantiate_app(mrb_state *mrb, RProc *proc) {
+  mrb->ud = nullptr;
+
+  auto res = mrb_top_run(mrb, proc, mrb_top_self(mrb), 0);
+
+  if (mrb->exc) {
+    auto exc = mrb_obj_value(mrb->exc);
+    auto inspect = mrb_inspect(mrb, exc);
+
+    LOG(ERROR) << "Exception caught while executing mruby code: "
+               << mrb_str_to_cstr(mrb, inspect);
+
+    return mrb_nil_value();
+  }
+
+  return res;
+}
+} // namespace
+
+// Based on
+// https://github.com/h2o/h2o/blob/master/lib/handler/mruby.c.  It is
+// very hard to write these kind of code because mruby has almost no
+// documentation about compiling or generating code, at least at the
+// time of this writing.
+RProc *compile(mrb_state *mrb, const StringRef &filename) {
+  if (filename.empty()) {
+    return nullptr;
+  }
+
+  auto infile = fopen(filename.c_str(), "rb");
+  if (infile == nullptr) {
+    LOG(ERROR) << "Could not open mruby file " << filename;
+    return nullptr;
+  }
+  auto infile_d = defer(fclose, infile);
+
+  auto mrbc = mrbc_context_new(mrb);
+  if (mrbc == nullptr) {
+    LOG(ERROR) << "mrb_context_new failed";
+    return nullptr;
+  }
+  auto mrbc_d = defer(mrbc_context_free, mrb, mrbc);
+
+  auto parser = mrb_parse_file(mrb, infile, nullptr);
+  if (parser == nullptr) {
+    LOG(ERROR) << "mrb_parse_nstring failed";
+    return nullptr;
+  }
+  auto parser_d = defer(mrb_parser_free, parser);
+
+  if (parser->nerr != 0) {
+    LOG(ERROR) << "mruby parser detected parse error";
+    return nullptr;
+  }
+
+  auto proc = mrb_generate_code(mrb, parser);
+  if (proc == nullptr) {
+    LOG(ERROR) << "mrb_generate_code failed";
+    return nullptr;
+  }
+
+  return proc;
+}
+
+std::unique_ptr<MRubyContext> create_mruby_context(const StringRef &filename) {
+  if (filename.empty()) {
+    return std::make_unique<MRubyContext>(nullptr, mrb_nil_value(),
+                                          mrb_nil_value());
+  }
+
+  auto mrb = mrb_open();
+  if (mrb == nullptr) {
+    LOG(ERROR) << "mrb_open failed";
+    return nullptr;
+  }
+
+  auto ai = mrb_gc_arena_save(mrb);
+
+  auto req_proc = compile(mrb, filename);
+
+  if (!req_proc) {
+    mrb_gc_arena_restore(mrb, ai);
+    LOG(ERROR) << "Could not compile mruby code " << filename;
+    mrb_close(mrb);
+    return nullptr;
+  }
+
+  auto env = init_module(mrb);
+
+  auto app = instantiate_app(mrb, req_proc);
+  if (mrb_nil_p(app)) {
+    mrb_gc_arena_restore(mrb, ai);
+    LOG(ERROR) << "Could not instantiate mruby app from " << filename;
+    mrb_close(mrb);
+    return nullptr;
+  }
+
+  mrb_gc_arena_restore(mrb, ai);
+
+  // TODO These are not necessary, because we retain app and env?
+  mrb_gc_protect(mrb, env);
+  mrb_gc_protect(mrb, app);
+
+  return std::make_unique<MRubyContext>(mrb, std::move(app), std::move(env));
+}
+
+mrb_sym intern_ptr(mrb_state *mrb, void *ptr) {
+  auto p = reinterpret_cast<uintptr_t>(ptr);
+
+  return mrb_intern(mrb, reinterpret_cast<const char *>(&p), sizeof(p));
+}
+
+void check_phase(mrb_state *mrb, int phase, int phase_mask) {
+  if ((phase & phase_mask) == 0) {
+    mrb_raise(mrb, E_RUNTIME_ERROR, "operation was not allowed in this phase");
+  }
+}
+
+} // namespace mruby
+
+} // namespace shrpx