Initial checkin of gRPC to third_party/

third_party/grpc/src/core/security/server_auth_filter.c

Index: third_party/grpc/src/core/security/server_auth_filter.c
diff --git a/third_party/grpc/src/core/security/server_auth_filter.c b/third_party/grpc/src/core/security/server_auth_filter.c
new file mode 100644
index 0000000000000000000000000000000000000000..3d8e5e8d35dda637c4b4132f155d2eab493be161
--- /dev/null
+++ b/third_party/grpc/src/core/security/server_auth_filter.c
@@ -0,0 +1,264 @@
+/*
+ *
+ * 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 <string.h>
+
+#include "src/core/security/auth_filters.h"
+#include "src/core/security/credentials.h"
+#include "src/core/security/security_context.h"
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+
+typedef struct call_data {
+  grpc_metadata_batch *recv_initial_metadata;
+  /* Closure to call when finished with the auth_on_recv hook. */
+  grpc_closure *on_done_recv;
+  /* Receive closures are chained: we inject this closure as the on_done_recv
+     up-call on transport_op, and remember to call our on_done_recv member after
+     handling it. */
+  grpc_closure auth_on_recv;
+  grpc_transport_stream_op transport_op;
+  grpc_metadata_array md;
+  const grpc_metadata *consumed_md;
+  size_t num_consumed_md;
+  grpc_auth_context *auth_context;
+} call_data;
+
+typedef struct channel_data {
+  grpc_auth_context *auth_context;
+  grpc_server_credentials *creds;
+} channel_data;
+
+static grpc_metadata_array metadata_batch_to_md_array(
+    const grpc_metadata_batch *batch) {
+  grpc_linked_mdelem *l;
+  grpc_metadata_array result;
+  grpc_metadata_array_init(&result);
+  for (l = batch->list.head; l != NULL; l = l->next) {
+    grpc_metadata *usr_md = NULL;
+    grpc_mdelem *md = l->md;
+    grpc_mdstr *key = md->key;
+    grpc_mdstr *value = md->value;
+    if (result.count == result.capacity) {
+      result.capacity = GPR_MAX(result.capacity + 8, result.capacity * 2);
+      result.metadata =
+          gpr_realloc(result.metadata, result.capacity * sizeof(grpc_metadata));
+    }
+    usr_md = &result.metadata[result.count++];
+    usr_md->key = grpc_mdstr_as_c_string(key);
+    usr_md->value = grpc_mdstr_as_c_string(value);
+    usr_md->value_length = GPR_SLICE_LENGTH(value->slice);
+  }
+  return result;
+}
+
+static grpc_mdelem *remove_consumed_md(void *user_data, grpc_mdelem *md) {
+  grpc_call_element *elem = user_data;
+  call_data *calld = elem->call_data;
+  size_t i;
+  for (i = 0; i < calld->num_consumed_md; i++) {
+    const grpc_metadata *consumed_md = &calld->consumed_md[i];
+    /* Maybe we could do a pointer comparison but we do not have any guarantee
+       that the metadata processor used the same pointers for consumed_md in the
+       callback. */
+    if (GPR_SLICE_LENGTH(md->key->slice) != strlen(consumed_md->key) ||
+        GPR_SLICE_LENGTH(md->value->slice) != consumed_md->value_length) {
+      continue;
+    }
+    if (memcmp(GPR_SLICE_START_PTR(md->key->slice), consumed_md->key,
+               GPR_SLICE_LENGTH(md->key->slice)) == 0 &&
+        memcmp(GPR_SLICE_START_PTR(md->value->slice), consumed_md->value,
+               GPR_SLICE_LENGTH(md->value->slice)) == 0) {
+      return NULL; /* Delete. */
+    }
+  }
+  return md;
+}
+
+/* called from application code */
+static void on_md_processing_done(
+    void *user_data, const grpc_metadata *consumed_md, size_t num_consumed_md,
+    const grpc_metadata *response_md, size_t num_response_md,
+    grpc_status_code status, const char *error_details) {
+  grpc_call_element *elem = user_data;
+  call_data *calld = elem->call_data;
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+
+  /* TODO(jboeuf): Implement support for response_md. */
+  if (response_md != NULL && num_response_md > 0) {
+    gpr_log(GPR_INFO,
+            "response_md in auth metadata processing not supported for now. "
+            "Ignoring...");
+  }
+
+  if (status == GRPC_STATUS_OK) {
+    calld->consumed_md = consumed_md;
+    calld->num_consumed_md = num_consumed_md;
+    grpc_metadata_batch_filter(calld->recv_initial_metadata, remove_consumed_md,
+                               elem);
+    grpc_metadata_array_destroy(&calld->md);
+    calld->on_done_recv->cb(&exec_ctx, calld->on_done_recv->cb_arg, 1);
+  } else {
+    gpr_slice message;
+    grpc_transport_stream_op close_op;
+    memset(&close_op, 0, sizeof(close_op));
+    grpc_metadata_array_destroy(&calld->md);
+    error_details = error_details != NULL
+                        ? error_details
+                        : "Authentication metadata processing failed.";
+    message = gpr_slice_from_copied_string(error_details);
+    calld->transport_op.send_initial_metadata = NULL;
+    if (calld->transport_op.send_message != NULL) {
+      grpc_byte_stream_destroy(&exec_ctx, calld->transport_op.send_message);
+      calld->transport_op.send_message = NULL;
+    }
+    calld->transport_op.send_trailing_metadata = NULL;
+    grpc_transport_stream_op_add_close(&close_op, status, &message);
+    grpc_call_next_op(&exec_ctx, elem, &close_op);
+    calld->on_done_recv->cb(&exec_ctx, calld->on_done_recv->cb_arg, 0);
+  }
+
+  grpc_exec_ctx_finish(&exec_ctx);
+}
+
+static void auth_on_recv(grpc_exec_ctx *exec_ctx, void *user_data,
+                         bool success) {
+  grpc_call_element *elem = user_data;
+  call_data *calld = elem->call_data;
+  channel_data *chand = elem->channel_data;
+  if (success) {
+    if (chand->creds->processor.process != NULL) {
+      calld->md = metadata_batch_to_md_array(calld->recv_initial_metadata);
+      chand->creds->processor.process(
+          chand->creds->processor.state, calld->auth_context,
+          calld->md.metadata, calld->md.count, on_md_processing_done, elem);
+      return;
+    }
+  }
+  calld->on_done_recv->cb(exec_ctx, calld->on_done_recv->cb_arg, success);
+}
+
+static void set_recv_ops_md_callbacks(grpc_call_element *elem,
+                                      grpc_transport_stream_op *op) {
+  call_data *calld = elem->call_data;
+
+  if (op->recv_initial_metadata != NULL) {
+    /* substitute our callback for the higher callback */
+    calld->recv_initial_metadata = op->recv_initial_metadata;
+    calld->on_done_recv = op->recv_initial_metadata_ready;
+    op->recv_initial_metadata_ready = &calld->auth_on_recv;
+    calld->transport_op = *op;
+  }
+}
+
+/* Called either:
+     - in response to an API call (or similar) from above, to send something
+     - a network event (or similar) from below, to receive something
+   op contains type and call direction information, in addition to the data
+   that is being sent or received. */
+static void auth_start_transport_op(grpc_exec_ctx *exec_ctx,
+                                    grpc_call_element *elem,
+                                    grpc_transport_stream_op *op) {
+  set_recv_ops_md_callbacks(elem, op);
+  grpc_call_next_op(exec_ctx, elem, op);
+}
+
+/* Constructor for call_data */
+static void init_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
+                           grpc_call_element_args *args) {
+  /* grab pointers to our data from the call element */
+  call_data *calld = elem->call_data;
+  channel_data *chand = elem->channel_data;
+  grpc_server_security_context *server_ctx = NULL;
+
+  /* initialize members */
+  memset(calld, 0, sizeof(*calld));
+  grpc_closure_init(&calld->auth_on_recv, auth_on_recv, elem);
+
+  if (args->context[GRPC_CONTEXT_SECURITY].value != NULL) {
+    args->context[GRPC_CONTEXT_SECURITY].destroy(
+        args->context[GRPC_CONTEXT_SECURITY].value);
+  }
+
+  server_ctx = grpc_server_security_context_create();
+  server_ctx->auth_context = grpc_auth_context_create(chand->auth_context);
+  calld->auth_context = server_ctx->auth_context;
+
+  args->context[GRPC_CONTEXT_SECURITY].value = server_ctx;
+  args->context[GRPC_CONTEXT_SECURITY].destroy =
+      grpc_server_security_context_destroy;
+}
+
+static void set_pollset(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
+                        grpc_pollset *pollset) {}
+
+/* Destructor for call_data */
+static void destroy_call_elem(grpc_exec_ctx *exec_ctx,
+                              grpc_call_element *elem) {}
+
+/* Constructor for channel_data */
+static void init_channel_elem(grpc_exec_ctx *exec_ctx,
+                              grpc_channel_element *elem,
+                              grpc_channel_element_args *args) {
+  grpc_auth_context *auth_context =
+      grpc_find_auth_context_in_args(args->channel_args);
+  grpc_server_credentials *creds =
+      grpc_find_server_credentials_in_args(args->channel_args);
+  /* grab pointers to our data from the channel element */
+  channel_data *chand = elem->channel_data;
+
+  GPR_ASSERT(!args->is_last);
+  GPR_ASSERT(auth_context != NULL);
+  GPR_ASSERT(creds != NULL);
+
+  /* initialize members */
+  chand->auth_context =
+      GRPC_AUTH_CONTEXT_REF(auth_context, "server_auth_filter");
+  chand->creds = grpc_server_credentials_ref(creds);
+}
+
+/* Destructor for channel data */
+static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,
+                                 grpc_channel_element *elem) {
+  /* grab pointers to our data from the channel element */
+  channel_data *chand = elem->channel_data;
+  GRPC_AUTH_CONTEXT_UNREF(chand->auth_context, "server_auth_filter");
+  grpc_server_credentials_unref(chand->creds);
+}
+
+const grpc_channel_filter grpc_server_auth_filter = {
+    auth_start_transport_op, grpc_channel_next_op, sizeof(call_data),
+    init_call_elem, set_pollset, destroy_call_elem, sizeof(channel_data),
+    init_channel_elem, destroy_channel_elem, grpc_call_next_get_peer,
+    "server-auth"};