src/core/lib/channel/message_size_filter.c

/*
 * Copyright 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 "src/core/lib/channel/message_size_filter.h"

#include <string.h>

#include <grpc/support/alloc.h>
#include <grpc/support/log.h>
#include <grpc/support/string_util.h>

/* the protobuf library will (by default) start warning at 100megs */
#define DEFAULT_MAX_MESSAGE_LENGTH (4 * 1024 * 1024)

typedef struct call_data {
  // Receive closures are chained: we inject this closure as the
  // recv_message_ready up-call on transport_stream_op, and remember to
  // call our next_recv_message_ready member after handling it.
  grpc_closure recv_message_ready;
  // Used by recv_message_ready.
  grpc_byte_stream** recv_message;
  // Original recv_message_ready callback, invoked after our own.
  grpc_closure* next_recv_message_ready;
} call_data;

typedef struct channel_data {
  size_t max_send_size;
  size_t max_recv_size;
} channel_data;

// Callback invoked when we receive a message.  Here we check the max
// receive message size.
static void recv_message_ready(grpc_exec_ctx* exec_ctx, void* user_data,
                               grpc_error* error) {
  grpc_call_element* elem = user_data;
  call_data* calld = elem->call_data;
  channel_data* chand = elem->channel_data;
  if ((*calld->recv_message)->length > chand->max_recv_size) {
    char* message_string;
    gpr_asprintf(&message_string, "Received message larger than max (%lu)",
                 chand->max_recv_size);
    gpr_slice message = gpr_slice_from_copied_string(message_string);
    gpr_free(message_string);
    grpc_call_element_send_cancel_with_message(
        exec_ctx, elem, GRPC_STATUS_INVALID_ARGUMENT, &message);
  }
  // Invoke the next callback.
  calld->next_recv_message_ready->cb(
      exec_ctx, calld->next_recv_message_ready->cb_arg, error);
}

// Start transport op.
static void start_transport_stream_op(grpc_exec_ctx* exec_ctx,
                                      grpc_call_element* elem,
                                      grpc_transport_stream_op* op) {
  call_data* calld = elem->call_data;
  channel_data* chand = elem->channel_data;
  // Check max send message size.
  if (op->send_message != NULL && chand->max_send_size > 0 &&
      op->send_message->length > chand->max_send_size) {
    char* message_string;
    gpr_asprintf(&message_string, "Sent message larger than max (%lu)",
                 chand->max_send_size);
    gpr_slice message = gpr_slice_from_copied_string(message_string);
    gpr_free(message_string);
    grpc_call_element_send_cancel_with_message(
        exec_ctx, elem, GRPC_STATUS_INVALID_ARGUMENT, &message);
  }
  // Inject callback for receiving a message.
  if (op->recv_message_ready != NULL && chand->max_recv_size > 0) {
    calld->next_recv_message_ready = op->recv_message_ready;
    calld->recv_message = op->recv_message;
    op->recv_message_ready = &calld->recv_message_ready;
  }
  // Chain to the next filter.
  grpc_call_next_op(exec_ctx, elem, op);
}

// Constructor for call_data.
static grpc_error* init_call_elem(grpc_exec_ctx* exec_ctx,
                                  grpc_call_element* elem,
                                  grpc_call_element_args* args) {
  call_data* calld = elem->call_data;
  calld->next_recv_message_ready = NULL;
  grpc_closure_init(&calld->recv_message_ready, recv_message_ready, elem);
  return GRPC_ERROR_NONE;
}

// Destructor for call_data.
static void destroy_call_elem(grpc_exec_ctx* exec_ctx, grpc_call_element* elem,
                              const grpc_call_final_info* final_info,
                              void* ignored) {}

// Constructor for channel_data.
static void init_channel_elem(grpc_exec_ctx* exec_ctx,
                              grpc_channel_element* elem,
                              grpc_channel_element_args* args) {
  GPR_ASSERT(!args->is_last);
  channel_data* chand = elem->channel_data;
  memset(chand, 0, sizeof(*chand));
  for (size_t i = 0; i < args->channel_args->num_args; ++i) {
    if (strcmp(args->channel_args->args[i].key,
               GRPC_ARG_MAX_SEND_MESSAGE_LENGTH) == 0) {
      if (args->channel_args->args[i].type != GRPC_ARG_INTEGER) {
        gpr_log(GPR_ERROR, "%s ignored: it must be an integer",
                GRPC_ARG_MAX_SEND_MESSAGE_LENGTH);
      } else if (args->channel_args->args[i].value.integer < 0) {
        gpr_log(GPR_ERROR, "%s ignored: it must be >= 0",
                GRPC_ARG_MAX_SEND_MESSAGE_LENGTH);
      } else {
        chand->max_send_size =
            (size_t)args->channel_args->args[i].value.integer;
      }
    }
    if (strcmp(args->channel_args->args[i].key,
               GRPC_ARG_MAX_RECEIVE_MESSAGE_LENGTH) == 0) {
      if (args->channel_args->args[i].type != GRPC_ARG_INTEGER) {
        gpr_log(GPR_ERROR, "%s ignored: it must be an integer",
                GRPC_ARG_MAX_RECEIVE_MESSAGE_LENGTH);
      } else if (args->channel_args->args[i].value.integer < 0) {
        gpr_log(GPR_ERROR, "%s ignored: it must be >= 0",
                GRPC_ARG_MAX_RECEIVE_MESSAGE_LENGTH);
      } else {
        chand->max_recv_size =
            (size_t)args->channel_args->args[i].value.integer;
      }
    }
  }
}

// Destructor for channel_data.
static void destroy_channel_elem(grpc_exec_ctx* exec_ctx,
                                 grpc_channel_element* elem) {}

const grpc_channel_filter grpc_message_size_filter = {
    start_transport_stream_op,
    grpc_channel_next_op,
    sizeof(call_data),
    init_call_elem,
    grpc_call_stack_ignore_set_pollset_or_pollset_set,
    destroy_call_elem,
    sizeof(channel_data),
    init_channel_elem,
    destroy_channel_elem,
    grpc_call_next_get_peer,
    "message_size"};