Initial checkin of gRPC to third_party/

third_party/grpc/src/ruby/ext/grpc/rb_call_credentials.c

Index: third_party/grpc/src/ruby/ext/grpc/rb_call_credentials.c
diff --git a/third_party/grpc/src/ruby/ext/grpc/rb_call_credentials.c b/third_party/grpc/src/ruby/ext/grpc/rb_call_credentials.c
new file mode 100644
index 0000000000000000000000000000000000000000..7c4b69f7f0dde33342bff0785c29e3b84989c625
--- /dev/null
+++ b/third_party/grpc/src/ruby/ext/grpc/rb_call_credentials.c
@@ -0,0 +1,317 @@
+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <ruby/ruby.h>
+#include "rb_grpc_imports.generated.h"
+#include "rb_call_credentials.h"
+
+#include <ruby/ruby.h>
+#include <ruby/thread.h>
+
+#include <grpc/grpc.h>
+#include <grpc/grpc_security.h>
+#include <grpc/support/alloc.h>
+
+#include "rb_call.h"
+#include "rb_event_thread.h"
+#include "rb_grpc.h"
+
+/* grpc_rb_cCallCredentials is the ruby class that proxies
+ * grpc_call_credentials */
+static VALUE grpc_rb_cCallCredentials = Qnil;
+
+/* grpc_rb_call_credentials wraps a grpc_call_credentials. It provides a mark
+ * object that is used to hold references to any objects used to create the
+ * credentials. */
+typedef struct grpc_rb_call_credentials {
+  /* Holder of ruby objects involved in contructing the credentials */
+  VALUE mark;
+
+  /* The actual credentials */
+  grpc_call_credentials *wrapped;
+} grpc_rb_call_credentials;
+
+typedef struct callback_params {
+  VALUE get_metadata;
+  grpc_auth_metadata_context context;
+  void *user_data;
+  grpc_credentials_plugin_metadata_cb callback;
+} callback_params;
+
+static VALUE grpc_rb_call_credentials_callback(VALUE callback_args) {
+  VALUE result = rb_hash_new();
+  VALUE metadata = rb_funcall(rb_ary_entry(callback_args, 0), rb_intern("call"),
+                              1, rb_ary_entry(callback_args, 1));
+  rb_hash_aset(result, rb_str_new2("metadata"), metadata);
+  rb_hash_aset(result, rb_str_new2("status"), INT2NUM(GRPC_STATUS_OK));
+  rb_hash_aset(result, rb_str_new2("details"), rb_str_new2(""));
+  return result;
+}
+
+static VALUE grpc_rb_call_credentials_callback_rescue(VALUE args,
+                                                      VALUE exception_object) {
+  VALUE result = rb_hash_new();
+  (void)args;
+  rb_hash_aset(result, rb_str_new2("metadata"), Qnil);
+  /* Currently only gives the exception class name. It should be possible get
+     more details */
+  rb_hash_aset(result, rb_str_new2("status"),
+               INT2NUM(GRPC_STATUS_PERMISSION_DENIED));
+  rb_hash_aset(result, rb_str_new2("details"),
+               rb_str_new2(rb_obj_classname(exception_object)));
+  return result;
+}
+
+static void grpc_rb_call_credentials_callback_with_gil(void *param) {
+  callback_params *const params = (callback_params *)param;
+  VALUE auth_uri = rb_str_new_cstr(params->context.service_url);
+  /* Pass the arguments to the proc in a hash, which currently only has they key
+     'auth_uri' */
+  VALUE callback_args = rb_ary_new();
+  VALUE args = rb_hash_new();
+  VALUE result;
+  grpc_metadata_array md_ary;
+  grpc_status_code status;
+  VALUE details;
+  char *error_details;
+  grpc_metadata_array_init(&md_ary);
+  rb_hash_aset(args, ID2SYM(rb_intern("jwt_aud_uri")), auth_uri);
+  rb_ary_push(callback_args, params->get_metadata);
+  rb_ary_push(callback_args, args);
+  result = rb_rescue(grpc_rb_call_credentials_callback, callback_args,
+                     grpc_rb_call_credentials_callback_rescue, Qnil);
+  // Both callbacks return a hash, so result should be a hash
+  grpc_rb_md_ary_convert(rb_hash_aref(result, rb_str_new2("metadata")), &md_ary);
+  status = NUM2INT(rb_hash_aref(result, rb_str_new2("status")));
+  details = rb_hash_aref(result, rb_str_new2("details"));
+  error_details = StringValueCStr(details);
+  params->callback(params->user_data, md_ary.metadata, md_ary.count, status,
+                   error_details);
+  grpc_metadata_array_destroy(&md_ary);
+  gpr_free(params);
+}
+
+static void grpc_rb_call_credentials_plugin_get_metadata(
+    void *state, grpc_auth_metadata_context context,
+    grpc_credentials_plugin_metadata_cb cb, void *user_data) {
+  callback_params *params = gpr_malloc(sizeof(callback_params));
+  params->get_metadata = (VALUE)state;
+  params->context = context;
+  params->user_data = user_data;
+  params->callback = cb;
+
+  grpc_rb_event_queue_enqueue(grpc_rb_call_credentials_callback_with_gil,
+                              (void*)(params));
+}
+
+static void grpc_rb_call_credentials_plugin_destroy(void *state) {
+  (void)state;
+  // Not sure what needs to be done here
+}
+
+/* Destroys the credentials instances. */
+static void grpc_rb_call_credentials_free(void *p) {
+  grpc_rb_call_credentials *wrapper;
+  if (p == NULL) {
+    return;
+  }
+  wrapper = (grpc_rb_call_credentials *)p;
+  grpc_call_credentials_release(wrapper->wrapped);
+  wrapper->wrapped = NULL;
+
+  xfree(p);
+}
+
+/* Protects the mark object from GC */
+static void grpc_rb_call_credentials_mark(void *p) {
+  grpc_rb_call_credentials *wrapper = NULL;
+  if (p == NULL) {
+    return;
+  }
+  wrapper = (grpc_rb_call_credentials *)p;
+  if (wrapper->mark != Qnil) {
+    rb_gc_mark(wrapper->mark);
+  }
+}
+
+static rb_data_type_t grpc_rb_call_credentials_data_type = {
+  "grpc_call_credentials",
+  {grpc_rb_call_credentials_mark, grpc_rb_call_credentials_free,
+   GRPC_RB_MEMSIZE_UNAVAILABLE, {NULL, NULL}},
+  NULL,
+  NULL,
+#ifdef RUBY_TYPED_FREE_IMMEDIATELY
+  RUBY_TYPED_FREE_IMMEDIATELY
+#endif
+};
+
+/* Allocates CallCredentials instances.
+   Provides safe initial defaults for the instance fields. */
+static VALUE grpc_rb_call_credentials_alloc(VALUE cls) {
+  grpc_rb_call_credentials *wrapper = ALLOC(grpc_rb_call_credentials);
+  wrapper->wrapped = NULL;
+  wrapper->mark = Qnil;
+  return TypedData_Wrap_Struct(cls, &grpc_rb_call_credentials_data_type, wrapper);
+}
+
+/* Creates a wrapping object for a given call credentials. This should only be
+ * called with grpc_call_credentials objects that are not already associated
+ * with any Ruby object */
+VALUE grpc_rb_wrap_call_credentials(grpc_call_credentials *c, VALUE mark) {
+  VALUE rb_wrapper;
+  grpc_rb_call_credentials *wrapper;
+  if (c == NULL) {
+    return Qnil;
+  }
+  rb_wrapper = grpc_rb_call_credentials_alloc(grpc_rb_cCallCredentials);
+  TypedData_Get_Struct(rb_wrapper, grpc_rb_call_credentials,
+                       &grpc_rb_call_credentials_data_type, wrapper);
+  wrapper->wrapped = c;
+  wrapper->mark = mark;
+  return rb_wrapper;
+}
+
+/* Clones CallCredentials instances.
+   Gives CallCredentials a consistent implementation of Ruby's object copy/dup
+   protocol. */
+static VALUE grpc_rb_call_credentials_init_copy(VALUE copy, VALUE orig) {
+  grpc_rb_call_credentials *orig_cred = NULL;
+  grpc_rb_call_credentials *copy_cred = NULL;
+
+  if (copy == orig) {
+    return copy;
+  }
+
+  /* Raise an error if orig is not a credentials object or a subclass. */
+  if (TYPE(orig) != T_DATA ||
+      RDATA(orig)->dfree != (RUBY_DATA_FUNC)grpc_rb_call_credentials_free) {
+    rb_raise(rb_eTypeError, "not a %s",
+             rb_obj_classname(grpc_rb_cCallCredentials));
+  }
+
+  TypedData_Get_Struct(orig, grpc_rb_call_credentials,
+                       &grpc_rb_call_credentials_data_type, orig_cred);
+  TypedData_Get_Struct(copy, grpc_rb_call_credentials,
+                       &grpc_rb_call_credentials_data_type, copy_cred);
+
+  /* use ruby's MEMCPY to make a byte-for-byte copy of the credentials
+   * wrapper object. */
+  MEMCPY(copy_cred, orig_cred, grpc_rb_call_credentials, 1);
+  return copy;
+}
+
+/* The attribute used on the mark object to hold the callback */
+static ID id_callback;
+
+/*
+  call-seq:
+    creds = Credentials.new auth_proc
+  proc: (required) Proc that generates auth metadata
+  Initializes CallCredential instances. */
+static VALUE grpc_rb_call_credentials_init(VALUE self, VALUE proc) {
+  grpc_rb_call_credentials *wrapper = NULL;
+  grpc_call_credentials *creds = NULL;
+  grpc_metadata_credentials_plugin plugin;
+
+  TypedData_Get_Struct(self, grpc_rb_call_credentials,
+                       &grpc_rb_call_credentials_data_type, wrapper);
+
+  plugin.get_metadata = grpc_rb_call_credentials_plugin_get_metadata;
+  plugin.destroy = grpc_rb_call_credentials_plugin_destroy;
+  if (!rb_obj_is_proc(proc)) {
+    rb_raise(rb_eTypeError, "Argument to CallCredentials#new must be a proc");
+    return Qnil;
+  }
+  plugin.state = (void*)proc;
+  plugin.type = "";
+
+  creds = grpc_metadata_credentials_create_from_plugin(plugin, NULL);
+  if (creds == NULL) {
+    rb_raise(rb_eRuntimeError, "could not create a credentials, not sure why");
+    return Qnil;
+  }
+
+  wrapper->mark = proc;
+  wrapper->wrapped = creds;
+  rb_ivar_set(self, id_callback, proc);
+
+  return self;
+}
+
+static VALUE grpc_rb_call_credentials_compose(int argc, VALUE *argv,
+                                              VALUE self) {
+  grpc_call_credentials *creds;
+  grpc_call_credentials *other;
+  VALUE mark;
+  if (argc == 0) {
+    return self;
+  }
+  mark = rb_ary_new();
+  creds = grpc_rb_get_wrapped_call_credentials(self);
+  for (int i = 0; i < argc; i++) {
+    rb_ary_push(mark, argv[i]);
+    other = grpc_rb_get_wrapped_call_credentials(argv[i]);
+    creds = grpc_composite_call_credentials_create(creds, other, NULL);
+  }
+  return grpc_rb_wrap_call_credentials(creds, mark);
+}
+
+void Init_grpc_call_credentials() {
+  grpc_rb_cCallCredentials =
+      rb_define_class_under(grpc_rb_mGrpcCore, "CallCredentials", rb_cObject);
+
+  /* Allocates an object managed by the ruby runtime */
+  rb_define_alloc_func(grpc_rb_cCallCredentials,
+                       grpc_rb_call_credentials_alloc);
+
+  /* Provides a ruby constructor and support for dup/clone. */
+  rb_define_method(grpc_rb_cCallCredentials, "initialize",
+                   grpc_rb_call_credentials_init, 1);
+  rb_define_method(grpc_rb_cCallCredentials, "initialize_copy",
+                   grpc_rb_call_credentials_init_copy, 1);
+  rb_define_method(grpc_rb_cCallCredentials, "compose",
+                   grpc_rb_call_credentials_compose, -1);
+
+  id_callback = rb_intern("__callback");
+
+  grpc_rb_event_queue_thread_start();
+}
+
+/* Gets the wrapped grpc_call_credentials from the ruby wrapper */
+grpc_call_credentials *grpc_rb_get_wrapped_call_credentials(VALUE v) {
+  grpc_rb_call_credentials *wrapper = NULL;
+  TypedData_Get_Struct(v, grpc_rb_call_credentials,
+                       &grpc_rb_call_credentials_data_type,
+                       wrapper);
+  return wrapper->wrapped;
+}