plugin_rest_peerinfo.c

Go to the documentation of this file.

/*
   This file is part of GNUnet.
   Copyright (C) 2012-2015 GNUnet e.V.
 
   GNUnet is free software: you can redistribute it and/or modify it
   under the terms of the GNU Affero General Public License as published
   by the Free Software Foundation, either version 3 of the License,
   or (at your option) any later version.
 
   GNUnet is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Affero General Public License for more details.
 
   You should have received a copy of the GNU Affero General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
     SPDX-License-Identifier: AGPL3.0-or-later
 */
#include "platform.h"
#include "gnunet_rest_plugin.h"
#include "gnunet_peerinfo_service.h"
#include "gnunet_transport_service.h"
#include "gnunet_rest_lib.h"
#include "gnunet_json_lib.h"
#include "microhttpd.h"
#include <jansson.h>
 
#define GNUNET_REST_API_NS_PEERINFO "/peerinfo"
 
#define GNUNET_REST_PEERINFO_PEER "peer"
 
#define GNUNET_REST_PEERINFO_FRIEND "friend"
 
#define GNUNET_REST_PEERINFO_ARRAY "array"
 
#define GNUNET_REST_PEERINFO_ERROR_UNKNOWN "Unknown Error"
 
#define TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5)
const struct GNUNET_CONFIGURATION_Handle *cfg;
 
static char *allow_methods;
 
static struct GNUNET_PEERINFO_Handle *peerinfo_handle;
 
struct Plugin
{
  const struct GNUNET_CONFIGURATION_Handle *cfg;
};
 
 
struct AddressRecord
{
  struct GNUNET_TRANSPORT_AddressToStringContext *atsc;
 
  struct GNUNET_TIME_Absolute expiration;
 
  char *result;
 
  struct PrintContext *pc;
};
 
 
struct PrintContext
{
  struct PrintContext *next;
 
  struct PrintContext *prev;
 
  struct GNUNET_PeerIdentity peer;
 
  struct AddressRecord *address_list;
 
  unsigned int num_addresses;
 
  unsigned int address_list_size;
 
  unsigned int off;
 
  int friend_only;
 
  struct RequestHandle *handle;
};
 
static struct PrintContext *pc_head;
 
static struct PrintContext *pc_tail;
 
struct RequestHandle
{
  struct RequestHandle *next;
 
  struct RequestHandle *prev;
 
  json_t *temp_array;
 
  char *expiration_str;
 
  const char *address;
 
  char *pubkey;
 
  json_t *response;
 
  struct GNUNET_PEERINFO_IteratorContext *list_it;
 
 
  struct GNUNET_REST_RequestHandle *rest_handle;
 
  struct GNUNET_TIME_Relative timeout;
 
  struct GNUNET_SCHEDULER_Task *timeout_task;
 
  GNUNET_REST_ResultProcessor proc;
 
  void *proc_cls;
 
  char *url;
 
  char *emsg;
 
  int response_code;
};
 
static struct RequestHandle *requests_head;
 
static struct RequestHandle *requests_tail;
 
static void
cleanup_handle (void *cls)
{
  struct RequestHandle *handle = cls;
 
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Cleaning up\n");
  if (NULL != handle->timeout_task)
  {
    GNUNET_SCHEDULER_cancel (handle->timeout_task);
    handle->timeout_task = NULL;
  }
  if (NULL != handle->url)
    GNUNET_free (handle->url);
  if (NULL != handle->emsg)
    GNUNET_free (handle->emsg);
  if (NULL != handle->address)
    GNUNET_free_nz ((char *) handle->address);
  if (NULL != handle->expiration_str)
    GNUNET_free (handle->expiration_str);
  if (NULL != handle->pubkey)
    GNUNET_free (handle->pubkey);
 
  if (NULL != handle->temp_array)
  {
    json_decref (handle->temp_array);
    handle->temp_array = NULL;
  }
  if (NULL != handle->response)
  {
    json_decref (handle->response);
    handle->response = NULL;
  }
 
  if (NULL != handle->list_it)
  {
    GNUNET_PEERINFO_iterate_cancel (handle->list_it);
    handle->list_it = NULL;
  }
  if (NULL != peerinfo_handle)
  {
    GNUNET_PEERINFO_disconnect (peerinfo_handle);
    peerinfo_handle = NULL;
  }
  GNUNET_CONTAINER_DLL_remove (requests_head,
                               requests_tail,
                               handle);
  GNUNET_free (handle);
}
 
 
static void
do_error (void *cls)
{
  struct RequestHandle *handle = cls;
  struct MHD_Response *resp;
  json_t *json_error = json_object ();
  char *response;
 
  if (NULL == handle->emsg)
    handle->emsg = GNUNET_strdup (GNUNET_REST_PEERINFO_ERROR_UNKNOWN);
 
  json_object_set_new (json_error, "error", json_string (handle->emsg));
 
  if (0 == handle->response_code)
    handle->response_code = MHD_HTTP_OK;
  response = json_dumps (json_error, 0);
  resp = GNUNET_REST_create_response (response);
  MHD_add_response_header (resp, "Content-Type", "application/json");
  handle->proc (handle->proc_cls, resp, handle->response_code);
  json_decref (json_error);
  GNUNET_free (response);
  GNUNET_SCHEDULER_add_now (&cleanup_handle, handle);
}
 
 
static void
peerinfo_list_finished (void *cls)
{
  struct RequestHandle *handle = cls;
  char *result_str;
  struct MHD_Response *resp;
 
  if (NULL == handle->response)
  {
    handle->response_code = MHD_HTTP_NOT_FOUND;
    handle->emsg = GNUNET_strdup ("No peers found");
    GNUNET_SCHEDULER_add_now (&do_error, handle);
    return;
  }
 
  result_str = json_dumps (handle->response, 0);
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Result %s\n", result_str);
  resp = GNUNET_REST_create_response (result_str);
  GNUNET_assert (MHD_NO != MHD_add_response_header (resp,
                                                    "Content-Type",
                                                    "application/json"));
  handle->proc (handle->proc_cls, resp, MHD_HTTP_OK);
  GNUNET_free (result_str);
  GNUNET_SCHEDULER_add_now (&cleanup_handle, handle);
}
 
 
static int
count_address (void *cls,
               const struct GNUNET_HELLO_Address *address,
               struct GNUNET_TIME_Absolute expiration)
{
  struct PrintContext *pc = cls;
 
  if (0 == GNUNET_TIME_absolute_get_remaining (expiration).rel_value_us)
  {
    return GNUNET_OK;          /* ignore expired address */
  }
 
  pc->off++;
  return GNUNET_OK;
}
 
 
static void
dump_pc (struct PrintContext *pc)
{
  struct RequestHandle *handle;
  unsigned int i;
  json_t *response_entry;
  json_t *temp_array;
  json_t *object;
  json_t *address;
  json_t *expires;
  json_t *friend_and_peer_json;
  char *friend_and_peer;
 
  temp_array = json_array ();
  response_entry = json_object ();
 
  for (i = 0; i < pc->num_addresses; i++)
  {
    if (NULL != pc->address_list[i].result)
    {
      object = json_object ();
      address = json_string (pc->address_list[i].result);
      expires = json_string (
        GNUNET_STRINGS_absolute_time_to_string (
          pc->address_list[i].expiration));
      json_object_set (object, "address", address);
      json_object_set (object, "expires", expires);
 
      json_decref (address);
      json_decref (expires);
 
      json_array_append (temp_array, object);
      json_decref (object);
      GNUNET_free (pc->address_list[i].result);
    }
  }
 
  if (0 < json_array_size (temp_array))
  {
    GNUNET_asprintf (&friend_and_peer,
                     "%s%s",
                     (GNUNET_YES == pc->friend_only) ? "F2F:" : "",
                     GNUNET_i2s_full (&pc->peer));
    friend_and_peer_json = json_string (friend_and_peer);
    json_object_set (response_entry,
                     GNUNET_REST_PEERINFO_PEER,
                     friend_and_peer_json);
    json_object_set (response_entry,
                     GNUNET_REST_PEERINFO_ARRAY,
                     temp_array);
    json_array_append (pc->handle->response, response_entry);
    json_decref (friend_and_peer_json);
    GNUNET_free (friend_and_peer);
  }
 
  json_decref (temp_array);
  json_decref (response_entry);
 
  GNUNET_free (pc->address_list);
  GNUNET_CONTAINER_DLL_remove (pc_head,
                               pc_tail,
                               pc);
  handle = pc->handle;
  GNUNET_free (pc);
 
  if ((NULL == pc_head) &&
      (NULL == handle->list_it))
  {
    GNUNET_SCHEDULER_add_now (&peerinfo_list_finished, handle);
  }
}
 
 
static void
process_resolved_address (void *cls,
                          const char *address,
                          int res)
{
  struct AddressRecord *ar = cls;
  struct PrintContext *pc = ar->pc;
 
  if (NULL != address)
  {
    if (0 != strlen (address))
    {
      if (NULL != ar->result)
        GNUNET_free (ar->result);
      ar->result = GNUNET_strdup (address);
    }
    return;
  }
  ar->atsc = NULL;
  if (GNUNET_SYSERR == res)
    GNUNET_log (GNUNET_ERROR_TYPE_INFO,
                _ ("Failure: Cannot convert address to string for peer `%s'\n"),
                GNUNET_i2s (&ar->pc->peer));
  pc->num_addresses++;
  if (pc->num_addresses == pc->address_list_size)
    dump_pc (ar->pc);
}
 
 
static int
print_address (void *cls,
               const struct GNUNET_HELLO_Address *address,
               struct GNUNET_TIME_Absolute expiration)
{
  struct PrintContext *pc = cls;
  struct AddressRecord *ar;
 
  if (0 == GNUNET_TIME_absolute_get_remaining (expiration).rel_value_us)
  {
    return GNUNET_OK;          /* ignore expired address */
  }
 
  GNUNET_assert (0 < pc->off);
  ar = &pc->address_list[--pc->off];
  ar->pc = pc;
  ar->expiration = expiration;
  GNUNET_asprintf (&ar->result,
                   "%s:%lu:%u",
                   address->transport_name,
                   (unsigned long) address->address_length,
                   address->local_info);
  ar->atsc = GNUNET_TRANSPORT_address_to_string (cfg,
                                                 address,
                                                 GNUNET_NO,
                                                 TIMEOUT,
                                                 &process_resolved_address,
                                                 ar);
  return GNUNET_OK;
}
 
 
void
peerinfo_list_iteration (void *cls,
                         const struct GNUNET_PeerIdentity *peer,
                         const struct GNUNET_HELLO_Message *hello,
                         const char *err_msg)
{
  struct RequestHandle *handle = cls;
  struct PrintContext *pc;
  int friend_only;
 
  if (NULL == handle->response)
  {
    handle->response = json_array ();
  }
 
  if (NULL == peer)
  {
    handle->list_it = NULL;
    handle->emsg = GNUNET_strdup ("Error in communication with peerinfo");
    if (NULL != err_msg)
    {
      GNUNET_free (handle->emsg);
      handle->emsg = GNUNET_strdup (err_msg);
      handle->response_code = MHD_HTTP_INTERNAL_SERVER_ERROR;
    }
    if (NULL == pc_head)
      GNUNET_SCHEDULER_add_now (&do_error, handle);
    return;
  }
  if (NULL == hello)
    return;
 
  friend_only = GNUNET_NO;
  if (NULL != hello)
    friend_only = GNUNET_HELLO_is_friend_only (hello);
 
  pc = GNUNET_new (struct PrintContext);
  GNUNET_CONTAINER_DLL_insert (pc_head,
                               pc_tail,
                               pc);
  pc->peer = *peer;
  pc->friend_only = friend_only;
  pc->handle = handle;
  GNUNET_HELLO_iterate_addresses (hello,
                                  GNUNET_NO,
                                  &count_address,
                                  pc);
  if (0 == pc->off)
  {
    dump_pc (pc);
    return;
  }
  pc->address_list_size = pc->off;
  pc->address_list = GNUNET_malloc (
    sizeof(struct AddressRecord) * pc->off);
  GNUNET_HELLO_iterate_addresses (hello,
                                  GNUNET_NO,
                                  &print_address,
                                  pc);
}
 
 
void
peerinfo_get (struct GNUNET_REST_RequestHandle *con_handle,
              const char*url,
              void *cls)
{
  struct RequestHandle *handle = cls;
  struct GNUNET_HashCode key;
  const struct GNUNET_PeerIdentity *specific_peer;
  // GNUNET_PEER_Id peer_id;
  int include_friend_only;
  char*include_friend_only_str;
 
  include_friend_only = GNUNET_NO;
  GNUNET_CRYPTO_hash (GNUNET_REST_PEERINFO_FRIEND,
                      strlen (GNUNET_REST_PEERINFO_FRIEND),
                      &key);
  if (GNUNET_YES
      == GNUNET_CONTAINER_multihashmap_contains (con_handle->url_param_map,
                                                 &key))
  {
    include_friend_only_str = GNUNET_CONTAINER_multihashmap_get (
      con_handle->url_param_map, &key);
    if (0 == strcmp (include_friend_only_str, "yes"))
    {
      include_friend_only = GNUNET_YES;
    }
  }
 
  specific_peer = NULL;
  GNUNET_CRYPTO_hash (GNUNET_REST_PEERINFO_PEER,
                      strlen (GNUNET_REST_PEERINFO_PEER),
                      &key);
  if (GNUNET_YES
      == GNUNET_CONTAINER_multihashmap_contains (con_handle->url_param_map,
                                                 &key))
  {
    // peer_id = *(unsigned int*)GNUNET_CONTAINER_multihashmap_get (con_handle->url_param_map, &key);
    // specific_peer = GNUNET_PEER_resolve2(peer_id);
  }
 
  handle->list_it = GNUNET_PEERINFO_iterate (peerinfo_handle,
                                             include_friend_only,
                                             specific_peer,
                                             &peerinfo_list_iteration,
                                             handle);
}
 
 
static void
options_cont (struct GNUNET_REST_RequestHandle *con_handle,
              const char*url,
              void *cls)
{
  struct MHD_Response *resp;
  struct RequestHandle *handle = cls;
 
  // independent of path return all options
  resp = GNUNET_REST_create_response (NULL);
  MHD_add_response_header (resp,
                           "Access-Control-Allow-Methods",
                           allow_methods);
  handle->proc (handle->proc_cls, resp, MHD_HTTP_OK);
  GNUNET_SCHEDULER_add_now (&cleanup_handle, handle);
  return;
}
 
 
static enum GNUNET_GenericReturnValue
rest_process_request (struct GNUNET_REST_RequestHandle *rest_handle,
                      GNUNET_REST_ResultProcessor proc,
                      void *proc_cls)
{
  struct RequestHandle *handle = GNUNET_new (struct RequestHandle);
  struct GNUNET_REST_RequestHandlerError err;
  static const struct GNUNET_REST_RequestHandler handlers[] = {
    { MHD_HTTP_METHOD_GET, GNUNET_REST_API_NS_PEERINFO, &peerinfo_get },
    { MHD_HTTP_METHOD_OPTIONS, GNUNET_REST_API_NS_PEERINFO, &options_cont },
    GNUNET_REST_HANDLER_END
  };
 
  handle->response_code = 0;
  handle->timeout = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS,
                                                   60);
  handle->proc_cls = proc_cls;
  handle->proc = proc;
  handle->rest_handle = rest_handle;
 
  handle->url = GNUNET_strdup (rest_handle->url);
  if (handle->url[strlen (handle->url) - 1] == '/')
    handle->url[strlen (handle->url) - 1] = '\0';
  handle->timeout_task =
    GNUNET_SCHEDULER_add_delayed (handle->timeout,
                                  &do_error,
                                  handle);
  GNUNET_CONTAINER_DLL_insert (requests_head,
                               requests_tail,
                               handle);
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Connecting...\n");
  if (GNUNET_NO == GNUNET_REST_handle_request (handle->rest_handle,
                                               handlers,
                                               &err,
                                               handle))
  {
    cleanup_handle (handle);
    return GNUNET_NO;
  }
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Connected\n");
  return GNUNET_YES;
}
 
 
void *
libgnunet_plugin_rest_peerinfo_init (void *cls)
{
  static struct Plugin plugin;
  struct GNUNET_REST_Plugin *api;
 
  cfg = cls;
  if (NULL != plugin.cfg)
    return NULL;                /* can only initialize once! */
  memset (&plugin, 0, sizeof(struct Plugin));
  plugin.cfg = cfg;
  api = GNUNET_new (struct GNUNET_REST_Plugin);
  api->cls = &plugin;
  api->name = GNUNET_REST_API_NS_PEERINFO;
  api->process_request = &rest_process_request;
  GNUNET_asprintf (&allow_methods,
                   "%s, %s, %s, %s, %s",
                   MHD_HTTP_METHOD_GET,
                   MHD_HTTP_METHOD_POST,
                   MHD_HTTP_METHOD_PUT,
                   MHD_HTTP_METHOD_DELETE,
                   MHD_HTTP_METHOD_OPTIONS);
  peerinfo_handle = GNUNET_PEERINFO_connect (cfg);
 
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              _ ("Peerinfo REST API initialized\n"));
  return api;
}
 
 
void *
libgnunet_plugin_rest_peerinfo_done (void *cls)
{
  struct GNUNET_REST_Plugin *api = cls;
  struct Plugin *plugin = api->cls;
 
  plugin->cfg = NULL;
  while (NULL != requests_head)
    cleanup_handle (requests_head);
  if (NULL != peerinfo_handle)
    GNUNET_PEERINFO_disconnect (peerinfo_handle);
 
  GNUNET_free (allow_methods);
  GNUNET_free (api);
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Peerinfo REST plugin is finished\n");
  return NULL;
}
 
 
/* end of plugin_rest_peerinfo.c */