src/core/security/server_secure_chttp2.c

/*
 *
 * Copyright 2015, 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 <grpc/grpc.h>

#include <string.h>

#include "src/core/channel/channel_args.h"
#include "src/core/channel/http_server_filter.h"
#include "src/core/iomgr/endpoint.h"
#include "src/core/iomgr/resolve_address.h"
#include "src/core/iomgr/tcp_server.h"
#include "src/core/security/auth_filters.h"
#include "src/core/security/credentials.h"
#include "src/core/security/security_connector.h"
#include "src/core/security/security_context.h"
#include "src/core/surface/server.h"
#include "src/core/transport/chttp2_transport.h"
#include <grpc/support/alloc.h>
#include <grpc/support/log.h>
#include <grpc/support/sync.h>
#include <grpc/support/useful.h>

typedef struct tcp_endpoint_list
{
  grpc_endpoint *tcp_endpoint;
  struct tcp_endpoint_list *next;
} tcp_endpoint_list;

typedef struct grpc_server_secure_state
{
  grpc_server *server;
  grpc_tcp_server *tcp;
  grpc_security_connector *sc;
  grpc_server_credentials *creds;
  tcp_endpoint_list *handshaking_tcp_endpoints;
  int is_shutdown;
  gpr_mu mu;
  gpr_refcount refcount;
  grpc_closure destroy_closure;
  grpc_closure *destroy_callback;
} grpc_server_secure_state;

static void
state_ref (grpc_server_secure_state * state)
{
  gpr_ref (&state->refcount);
}

static void
state_unref (grpc_server_secure_state * state)
{
  if (gpr_unref (&state->refcount))
    {
      /* ensure all threads have unlocked */
      gpr_mu_lock (&state->mu);
      gpr_mu_unlock (&state->mu);
      /* clean up */
      GRPC_SECURITY_CONNECTOR_UNREF (state->sc, "server");
      grpc_server_credentials_unref (state->creds);
      gpr_free (state);
    }
}

static void
setup_transport (grpc_exec_ctx * exec_ctx, void *statep, grpc_transport * transport, grpc_mdctx * mdctx)
{
  static grpc_channel_filter const *extra_filters[] = {
    &grpc_server_auth_filter, &grpc_http_server_filter
  };
  grpc_server_secure_state *state = statep;
  grpc_channel_args *args_copy;
  grpc_arg args_to_add[2];
  args_to_add[0] = grpc_security_connector_to_arg (state->sc);
  args_to_add[1] = grpc_auth_metadata_processor_to_arg (&state->creds->processor);
  args_copy = grpc_channel_args_copy_and_add (grpc_server_get_channel_args (state->server), args_to_add, GPR_ARRAY_SIZE (args_to_add));
  grpc_server_setup_transport (state->server, transport, extra_filters, GPR_ARRAY_SIZE (exec_ctx, extra_filters), mdctx, args_copy);
  grpc_channel_args_destroy (args_copy);
}

static int
remove_tcp_from_list_locked (grpc_server_secure_state * state, grpc_endpoint * tcp)
{
  tcp_endpoint_list *node = state->handshaking_tcp_endpoints;
  tcp_endpoint_list *tmp = NULL;
  if (node && node->tcp_endpoint == tcp)
    {
      state->handshaking_tcp_endpoints = state->handshaking_tcp_endpoints->next;
      gpr_free (node);
      return 0;
    }
  while (node)
    {
      if (node->next->tcp_endpoint == tcp)
	{
	  tmp = node->next;
	  node->next = node->next->next;
	  gpr_free (tmp);
	  return 0;
	}
      node = node->next;
    }
  return -1;
}

static void
on_secure_handshake_done (grpc_exec_ctx * exec_ctx, void *statep, grpc_security_status status, grpc_endpoint * wrapped_endpoint, grpc_endpoint * secure_endpoint)
{
  grpc_server_secure_state *state = statep;
  grpc_transport *transport;
  grpc_mdctx *mdctx;
  if (status == GRPC_SECURITY_OK)
    {
      gpr_mu_lock (&state->mu);
      remove_tcp_from_list_locked (state, wrapped_endpoint);
      if (!state->is_shutdown)
	{
	  mdctx = grpc_mdctx_create ();
	  transport = grpc_create_chttp2_transport (grpc_server_get_channel_args (exec_ctx, state->server), secure_endpoint, mdctx, 0);
	  setup_transport (exec_ctx, state, transport, mdctx);
	  grpc_chttp2_transport_start_reading (exec_ctx, transport, NULL, 0);
	}
      else
	{
	  /* We need to consume this here, because the server may already have gone
	   * away. */
	  grpc_endpoint_destroy (exec_ctx, secure_endpoint);
	}
      gpr_mu_unlock (&state->mu);
    }
  else
    {
      gpr_mu_lock (&state->mu);
      remove_tcp_from_list_locked (state, wrapped_endpoint);
      gpr_mu_unlock (&state->mu);
      gpr_log (GPR_ERROR, "Secure transport failed with error %d", status);
    }
  state_unref (state);
}

static void
on_accept (grpc_exec_ctx * exec_ctx, void *statep, grpc_endpoint * tcp)
{
  grpc_server_secure_state *state = statep;
  tcp_endpoint_list *node;
  state_ref (state);
  node = gpr_malloc (sizeof (tcp_endpoint_list));
  node->tcp_endpoint = tcp;
  gpr_mu_lock (&state->mu);
  node->next = state->handshaking_tcp_endpoints;
  state->handshaking_tcp_endpoints = node;
  gpr_mu_unlock (&state->mu);
  grpc_security_connector_do_handshake (exec_ctx, state->sc, tcp, on_secure_handshake_done, state);
}

/* Server callback: start listening on our ports */
static void
start (grpc_exec_ctx * exec_ctx, grpc_server * server, void *statep, grpc_pollset ** pollsets, size_t pollset_count)
{
  grpc_server_secure_state *state = statep;
  grpc_tcp_server_start (exec_ctx, state->tcp, pollsets, pollset_count, on_accept, state);
}

static void
destroy_done (grpc_exec_ctx * exec_ctx, void *statep, int success)
{
  grpc_server_secure_state *state = statep;
  state->destroy_callback->cb (exec_ctx, state->destroy_callback->cb_arg, success);
  gpr_mu_lock (&state->mu);
  while (state->handshaking_tcp_endpoints != NULL)
    {
      grpc_endpoint_shutdown (exec_ctx, state->handshaking_tcp_endpoints->tcp_endpoint);
      remove_tcp_from_list_locked (state, state->handshaking_tcp_endpoints->tcp_endpoint);
    }
  gpr_mu_unlock (&state->mu);
  state_unref (state);
}

/* Server callback: destroy the tcp listener (so we don't generate further
   callbacks) */
static void
destroy (grpc_exec_ctx * exec_ctx, grpc_server * server, void *statep, grpc_closure * callback)
{
  grpc_server_secure_state *state = statep;
  grpc_tcp_server *tcp;
  gpr_mu_lock (&state->mu);
  state->is_shutdown = 1;
  state->destroy_callback = callback;
  tcp = state->tcp;
  gpr_mu_unlock (&state->mu);
  grpc_closure_init (&state->destroy_closure, destroy_done, state);
  grpc_tcp_server_destroy (exec_ctx, tcp, &state->destroy_closure);
}

int
grpc_server_add_secure_http2_port (grpc_server * server, const char *addr, grpc_server_credentials * creds)
{
  grpc_resolved_addresses *resolved = NULL;
  grpc_tcp_server *tcp = NULL;
  grpc_server_secure_state *state = NULL;
  size_t i;
  unsigned count = 0;
  int port_num = -1;
  int port_temp;
  grpc_security_status status = GRPC_SECURITY_ERROR;
  grpc_security_connector *sc = NULL;
  grpc_closure_list closure_list = GRPC_CLOSURE_LIST_INIT;

  /* create security context */
  if (creds == NULL)
    goto error;
  status = grpc_server_credentials_create_security_connector (creds, &sc);
  if (status != GRPC_SECURITY_OK)
    {
      gpr_log (GPR_ERROR, "Unable to create secure server with credentials of type %s.", creds->type);
      goto error;
    }

  /* resolve address */
  resolved = grpc_blocking_resolve_address (addr, "https");
  if (!resolved)
    {
      goto error;
    }

  tcp = grpc_tcp_server_create ();
  if (!tcp)
    {
      goto error;
    }

  for (i = 0; i < resolved->naddrs; i++)
    {
      port_temp = grpc_tcp_server_add_port (tcp, (struct sockaddr *) &resolved->addrs[i].addr, resolved->addrs[i].len);
      if (port_temp >= 0)
	{
	  if (port_num == -1)
	    {
	      port_num = port_temp;
	    }
	  else
	    {
	      GPR_ASSERT (port_num == port_temp);
	    }
	  count++;
	}
    }
  if (count == 0)
    {
      gpr_log (GPR_ERROR, "No address added out of total %d resolved", resolved->naddrs);
      goto error;
    }
  if (count != resolved->naddrs)
    {
      gpr_log (GPR_ERROR, "Only %d addresses added out of total %d resolved", count, resolved->naddrs);
      /* if it's an error, don't we want to goto error; here ? */
    }
  grpc_resolved_addresses_destroy (resolved);

  state = gpr_malloc (sizeof (*state));
  memset (state, 0, sizeof (*state));
  state->server = server;
  state->tcp = tcp;
  state->sc = sc;
  state->creds = grpc_server_credentials_ref (creds);

  state->handshaking_tcp_endpoints = NULL;
  state->is_shutdown = 0;
  gpr_mu_init (&state->mu);
  gpr_ref_init (&state->refcount, 1);

  /* Register with the server only upon success */
  grpc_server_add_listener (server, state, start, destroy, &closure_list);

  grpc_closure_list_run (&closure_list);
  return port_num;

/* Error path: cleanup and return */
error:
  if (sc)
    {
      GRPC_SECURITY_CONNECTOR_UNREF (sc, "server");
    }
  if (resolved)
    {
      grpc_resolved_addresses_destroy (resolved);
    }
  if (tcp)
    {
      grpc_tcp_server_destroy (tcp, NULL, &closure_list);
    }
  if (state)
    {
      gpr_free (state);
    }
  grpc_closure_list_run (&closure_list);
  return 0;
}