plugin_rest_namestore.c

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/*
   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_gns_service.h"
#include "gnunet_namestore_service.h"
#include "gnunet_identity_service.h"
#include "gnunet_rest_lib.h"
#include "gnunet_json_lib.h"
#include "microhttpd.h"
#include <jansson.h>

#define GNUNET_REST_API_NS_NAMESTORE "/namestore"

#define GNUNET_REST_NAMESTORE_ERROR_UNKNOWN "Unknown Error"

#define GNUNET_REST_IDENTITY_NOT_FOUND "No identity found"


#define GNUNET_REST_NAMESTORE_FAILED "Namestore action failed"

#define GNUNET_REST_NAMESTORE_INVALID_DATA "Data invalid"

#define GNUNET_REST_NAMESTORE_NO_DATA "No data"

#define ID_REST_STATE_INIT 0

#define ID_REST_STATE_POST_INIT 1

const struct GNUNET_CONFIGURATION_Handle *cfg;

static char *allow_methods;

struct Plugin {
  const struct GNUNET_CONFIGURATION_Handle *cfg;
};

struct EgoEntry {
  struct EgoEntry *next;

  struct EgoEntry *prev;

  char *identifier;

  char *keystring;

  struct GNUNET_IDENTITY_Ego *ego;
};

struct RequestHandle {
  char *record_name;

  struct GNUNET_GNSRECORD_Data *rd;

  unsigned int rd_count;

  struct GNUNET_NAMESTORE_QueueEntry *add_qe;

  json_t *resp_object;

  int state;

  struct GNUNET_NAMESTORE_Handle *ns_handle;

  struct GNUNET_NAMESTORE_ZoneIterator *list_it;

  const struct GNUNET_CRYPTO_EcdsaPrivateKey *zone_pkey;

  struct EgoEntry *ego_entry;

  struct EgoEntry *ego_head;

  struct EgoEntry *ego_tail;

  struct GNUNET_IDENTITY_Operation *op;

  struct GNUNET_IDENTITY_Handle *identity_handle;

  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 void
cleanup_handle(void *cls)
{
  struct RequestHandle *handle = cls;
  struct EgoEntry *ego_entry;
  struct EgoEntry *ego_tmp;

  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->record_name)
    GNUNET_free(handle->record_name);
  if (NULL != handle->url)
    GNUNET_free(handle->url);
  if (NULL != handle->emsg)
    GNUNET_free(handle->emsg);
  if (NULL != handle->rd)
    {
      for (int i = 0; i < handle->rd_count; i++)
        {
          if (NULL != handle->rd[i].data)
            GNUNET_free((void *)handle->rd[i].data);
        }
      GNUNET_free(handle->rd);
    }
  if (NULL != handle->timeout_task)
    GNUNET_SCHEDULER_cancel(handle->timeout_task);
  if (NULL != handle->list_it)
    GNUNET_NAMESTORE_zone_iteration_stop(handle->list_it);
  if (NULL != handle->add_qe)
    GNUNET_NAMESTORE_cancel(handle->add_qe);
  if (NULL != handle->identity_handle)
    GNUNET_IDENTITY_disconnect(handle->identity_handle);
  if (NULL != handle->ns_handle)
    {
      GNUNET_NAMESTORE_disconnect(handle->ns_handle);
    }

  for (ego_entry = handle->ego_head; NULL != ego_entry;)
    {
      ego_tmp = ego_entry;
      ego_entry = ego_entry->next;
      GNUNET_free(ego_tmp->identifier);
      GNUNET_free(ego_tmp->keystring);
      GNUNET_free(ego_tmp);
    }

  if (NULL != handle->resp_object)
    {
      json_decref(handle->resp_object);
    }

  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_NAMESTORE_ERROR_UNKNOWN);

  json_object_set_new(json_error, "error", json_string(handle->emsg));

  if (0 == handle->response_code)
    handle->response_code = MHD_HTTP_INTERNAL_SERVER_ERROR;
  response = json_dumps(json_error, 0);
  resp = GNUNET_REST_create_response(response);
  handle->proc(handle->proc_cls, resp, handle->response_code);
  json_decref(json_error);
  GNUNET_free(response);
  GNUNET_SCHEDULER_add_now(&cleanup_handle, handle);
}


struct EgoEntry *
get_egoentry_namestore(struct RequestHandle *handle, char *name)
{
  struct EgoEntry *ego_entry;

  if (NULL != name)
    {
      for (ego_entry = handle->ego_head; NULL != ego_entry;
           ego_entry = ego_entry->next)
        {
          if (0 != strcasecmp(name, ego_entry->identifier))
            continue;
          return ego_entry;
        }
    }
  return NULL;
}


static void
namestore_iteration_error(void *cls)
{
  struct RequestHandle *handle = cls;

  handle->emsg = GNUNET_strdup(GNUNET_REST_NAMESTORE_FAILED);
  GNUNET_SCHEDULER_add_now(&do_error, handle);
  return;
}


static void
create_finished(void *cls, int32_t success, const char *emsg)
{
  struct RequestHandle *handle = cls;
  struct MHD_Response *resp;

  handle->add_qe = NULL;
  if (GNUNET_YES != success)
    {
      if (NULL != emsg)
        {
          handle->emsg = GNUNET_strdup(emsg);
          GNUNET_SCHEDULER_add_now(&do_error, handle);
          return;
        }
      handle->emsg = GNUNET_strdup("Error storing records");
      GNUNET_SCHEDULER_add_now(&do_error, handle);
      return;
    }
  resp = GNUNET_REST_create_response(NULL);
  handle->proc(handle->proc_cls, resp, MHD_HTTP_NO_CONTENT);
  GNUNET_SCHEDULER_add_now(&cleanup_handle, handle);
}


static void
del_finished(void *cls, int32_t success, const char *emsg)
{
  struct RequestHandle *handle = cls;

  handle->add_qe = NULL;
  if (GNUNET_NO == success)
    {
      handle->response_code = MHD_HTTP_NOT_FOUND;
      handle->emsg = GNUNET_strdup("No record found");
      GNUNET_SCHEDULER_add_now(&do_error, handle);
      return;
    }
  if (GNUNET_SYSERR == success)
    {
      if (NULL != emsg)
        {
          handle->emsg = GNUNET_strdup(emsg);
          GNUNET_SCHEDULER_add_now(&do_error, handle);
          return;
        }
      handle->emsg = GNUNET_strdup("Deleting record failed");
      GNUNET_SCHEDULER_add_now(&do_error, handle);
      return;
    }
  handle->proc(handle->proc_cls,
               GNUNET_REST_create_response(NULL),
               MHD_HTTP_NO_CONTENT);
  GNUNET_SCHEDULER_add_now(&cleanup_handle, handle);
}


static void
namestore_list_finished(void *cls)
{
  struct RequestHandle *handle = cls;
  char *result_str;
  struct MHD_Response *resp;

  handle->list_it = NULL;

  if (NULL == handle->resp_object)
    handle->resp_object = json_array();

  result_str = json_dumps(handle->resp_object, 0);
  GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Result %s\n", result_str);
  resp = GNUNET_REST_create_response(result_str);
  handle->proc(handle->proc_cls, resp, MHD_HTTP_OK);
  GNUNET_free_non_null(result_str);
  GNUNET_SCHEDULER_add_now(&cleanup_handle, handle);
}


static void
namestore_list_iteration(void *cls,
                         const struct GNUNET_CRYPTO_EcdsaPrivateKey *zone_key,
                         const char *rname,
                         unsigned int rd_len,
                         const struct GNUNET_GNSRECORD_Data *rd)
{
  struct RequestHandle *handle = cls;
  json_t *record_obj;

  if (NULL == handle->resp_object)
    handle->resp_object = json_array();
  record_obj = GNUNET_JSON_from_gnsrecord(rname,
                                          rd,
                                          rd_len);
  json_array_append_new(handle->resp_object, record_obj);
  GNUNET_NAMESTORE_zone_iterator_next(handle->list_it, 1);
}


void
namestore_get(struct GNUNET_REST_RequestHandle *con_handle,
              const char *url,
              void *cls)
{
  struct RequestHandle *handle = cls;
  struct EgoEntry *ego_entry;
  char *egoname;

  egoname = NULL;
  ego_entry = NULL;

  // set zone to name if given
  if (strlen(GNUNET_REST_API_NS_NAMESTORE) < strlen(handle->url))
    {
      egoname = &handle->url[strlen(GNUNET_REST_API_NS_NAMESTORE) + 1];
      ego_entry = get_egoentry_namestore(handle, egoname);

      if (NULL == ego_entry)
        {
          handle->response_code = MHD_HTTP_NOT_FOUND;
          handle->emsg = GNUNET_strdup(GNUNET_REST_IDENTITY_NOT_FOUND);
          GNUNET_SCHEDULER_add_now(&do_error, handle);
          return;
        }
    }
  if (NULL != ego_entry)
    handle->zone_pkey = GNUNET_IDENTITY_ego_get_private_key(ego_entry->ego);

  handle->list_it =
    GNUNET_NAMESTORE_zone_iteration_start(handle->ns_handle,
                                          handle->zone_pkey,
                                          &namestore_iteration_error,
                                          handle,
                                          &namestore_list_iteration,
                                          handle,
                                          &namestore_list_finished,
                                          handle);
  if (NULL == handle->list_it)
    {
      handle->emsg = GNUNET_strdup(GNUNET_REST_NAMESTORE_FAILED);
      GNUNET_SCHEDULER_add_now(&do_error, handle);
      return;
    }
}


static void
ns_lookup_error_cb(void *cls)
{
  struct RequestHandle *handle = cls;

  handle->emsg = GNUNET_strdup(GNUNET_REST_NAMESTORE_FAILED);
  GNUNET_SCHEDULER_add_now(&do_error, handle);
}


static void
ns_lookup_cb(void *cls,
             const struct GNUNET_CRYPTO_EcdsaPrivateKey *zone,
             const char *label,
             unsigned int rd_count,
             const struct GNUNET_GNSRECORD_Data *rd)
{
  struct RequestHandle *handle = cls;
  struct GNUNET_GNSRECORD_Data rd_new[rd_count + handle->rd_count];

  for (int i = 0; i < rd_count; i++)
    rd_new[i] = rd[i];
  for (int j = 0; j < handle->rd_count; j++)
    rd_new[rd_count + j] = handle->rd[j];
  handle->add_qe = GNUNET_NAMESTORE_records_store(handle->ns_handle,
                                                  handle->zone_pkey,
                                                  handle->record_name,
                                                  rd_count + handle->rd_count,
                                                  rd_new,
                                                  &create_finished,
                                                  handle);
  if (NULL == handle->add_qe)
    {
      handle->emsg = GNUNET_strdup(GNUNET_REST_NAMESTORE_FAILED);
      GNUNET_SCHEDULER_add_now(&do_error, handle);
      return;
    }
}


void
namestore_add(struct GNUNET_REST_RequestHandle *con_handle,
              const char *url,
              void *cls)
{
  struct RequestHandle *handle = cls;
  struct EgoEntry *ego_entry;
  char *egoname;
  json_t *data_js;
  json_error_t err;

  char term_data[handle->rest_handle->data_size + 1];

  if (0 >= handle->rest_handle->data_size)
    {
      handle->emsg = GNUNET_strdup(GNUNET_REST_NAMESTORE_NO_DATA);
      GNUNET_SCHEDULER_add_now(&do_error, handle);
      return;
    }
  term_data[handle->rest_handle->data_size] = '\0';
  GNUNET_memcpy(term_data,
                handle->rest_handle->data,
                handle->rest_handle->data_size);
  data_js = json_loads(term_data, JSON_DECODE_ANY, &err);
  struct GNUNET_JSON_Specification gnsspec[] =
  { GNUNET_JSON_spec_gnsrecord(&handle->rd, &handle->rd_count, &handle->record_name), GNUNET_JSON_spec_end() };
  if (GNUNET_OK != GNUNET_JSON_parse(data_js, gnsspec, NULL, NULL))
    {
      handle->emsg = GNUNET_strdup(GNUNET_REST_NAMESTORE_INVALID_DATA);
      GNUNET_SCHEDULER_add_now(&do_error, handle);
      json_decref(data_js);
      return;
    }
  GNUNET_JSON_parse_free(gnsspec);
  if (0 >= strlen(handle->record_name))
    {
      handle->emsg = GNUNET_strdup(GNUNET_REST_NAMESTORE_INVALID_DATA);
      GNUNET_SCHEDULER_add_now(&do_error, handle);
      json_decref(data_js);
      return;
    }
  json_decref(data_js);

  egoname = NULL;
  ego_entry = NULL;

  // set zone to name if given
  if (strlen(GNUNET_REST_API_NS_NAMESTORE) < strlen(handle->url))
    {
      egoname = &handle->url[strlen(GNUNET_REST_API_NS_NAMESTORE) + 1];
      ego_entry = get_egoentry_namestore(handle, egoname);

      if (NULL == ego_entry)
        {
          handle->response_code = MHD_HTTP_NOT_FOUND;
          handle->emsg = GNUNET_strdup(GNUNET_REST_IDENTITY_NOT_FOUND);
          GNUNET_SCHEDULER_add_now(&do_error, handle);
          return;
        }
    }
  if (NULL != ego_entry)
    handle->zone_pkey = GNUNET_IDENTITY_ego_get_private_key(ego_entry->ego);
  handle->add_qe = GNUNET_NAMESTORE_records_lookup(handle->ns_handle,
                                                   handle->zone_pkey,
                                                   handle->record_name,
                                                   &ns_lookup_error_cb,
                                                   handle,
                                                   &ns_lookup_cb,
                                                   handle);
  if (NULL == handle->add_qe)
    {
      handle->emsg = GNUNET_strdup(GNUNET_REST_NAMESTORE_FAILED);
      GNUNET_SCHEDULER_add_now(&do_error, handle);
      return;
    }
}


void
namestore_delete(struct GNUNET_REST_RequestHandle *con_handle,
                 const char *url,
                 void *cls)
{
  struct RequestHandle *handle = cls;
  struct GNUNET_HashCode key;
  struct EgoEntry *ego_entry;
  char *egoname;

  egoname = NULL;
  ego_entry = NULL;

  // set zone to name if given
  if (strlen(GNUNET_REST_API_NS_NAMESTORE) < strlen(handle->url))
    {
      egoname = &handle->url[strlen(GNUNET_REST_API_NS_NAMESTORE) + 1];
      ego_entry = get_egoentry_namestore(handle, egoname);

      if (NULL == ego_entry)
        {
          handle->response_code = MHD_HTTP_NOT_FOUND;
          handle->emsg = GNUNET_strdup(GNUNET_REST_IDENTITY_NOT_FOUND);
          GNUNET_SCHEDULER_add_now(&do_error, handle);
          return;
        }
    }
  if (NULL != ego_entry)
    handle->zone_pkey = GNUNET_IDENTITY_ego_get_private_key(ego_entry->ego);

  GNUNET_CRYPTO_hash("record_name", strlen("record_name"), &key);
  if (GNUNET_NO ==
      GNUNET_CONTAINER_multihashmap_contains(con_handle->url_param_map, &key))
    {
      handle->emsg = GNUNET_strdup(GNUNET_REST_NAMESTORE_INVALID_DATA);
      GNUNET_SCHEDULER_add_now(&do_error, handle);
      return;
    }
  handle->record_name = GNUNET_strdup(
    GNUNET_CONTAINER_multihashmap_get(con_handle->url_param_map, &key));

  handle->add_qe = GNUNET_NAMESTORE_records_store(handle->ns_handle,
                                                  handle->zone_pkey,
                                                  handle->record_name,
                                                  0,
                                                  NULL,
                                                  &del_finished,
                                                  handle);
  if (NULL == handle->add_qe)
    {
      handle->emsg = GNUNET_strdup(GNUNET_REST_NAMESTORE_FAILED);
      GNUNET_SCHEDULER_add_now(&do_error, handle);
      return;
    }
}


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 void
init_cont(struct RequestHandle *handle)
{
  struct GNUNET_REST_RequestHandlerError err;
  static const struct GNUNET_REST_RequestHandler handlers[] =
  { { MHD_HTTP_METHOD_GET, GNUNET_REST_API_NS_NAMESTORE, &namestore_get },
    { MHD_HTTP_METHOD_POST, GNUNET_REST_API_NS_NAMESTORE, &namestore_add },
    { MHD_HTTP_METHOD_DELETE, GNUNET_REST_API_NS_NAMESTORE, &namestore_delete },
    { MHD_HTTP_METHOD_OPTIONS, GNUNET_REST_API_NS_NAMESTORE, &options_cont },
    GNUNET_REST_HANDLER_END };

  if (GNUNET_NO ==
      GNUNET_REST_handle_request(handle->rest_handle, handlers, &err, handle))
    {
      handle->response_code = err.error_code;
      GNUNET_SCHEDULER_add_now(&do_error, handle);
    }
}


static void
id_connect_cb(void *cls,
              struct GNUNET_IDENTITY_Ego *ego,
              void **ctx,
              const char *name)
{
  struct RequestHandle *handle = cls;
  struct EgoEntry *ego_entry;
  struct GNUNET_CRYPTO_EcdsaPublicKey pk;

  if ((NULL == ego) && (ID_REST_STATE_INIT == handle->state))
    {
      handle->state = ID_REST_STATE_POST_INIT;
      init_cont(handle);
      return;
    }
  if (ID_REST_STATE_INIT == handle->state)
    {
      ego_entry = GNUNET_new(struct EgoEntry);
      GNUNET_IDENTITY_ego_get_public_key(ego, &pk);
      ego_entry->keystring = GNUNET_CRYPTO_ecdsa_public_key_to_string(&pk);
      ego_entry->ego = ego;
      GNUNET_asprintf(&ego_entry->identifier, "%s", name);
      GNUNET_CONTAINER_DLL_insert_tail(handle->ego_head,
                                       handle->ego_tail,
                                       ego_entry);
    }
}


static void
rest_process_request(struct GNUNET_REST_RequestHandle *rest_handle,
                     GNUNET_REST_ResultProcessor proc,
                     void *proc_cls)
{
  struct RequestHandle *handle = GNUNET_new(struct RequestHandle);

  handle->response_code = 0;
  handle->timeout = GNUNET_TIME_UNIT_FOREVER_REL;
  handle->proc_cls = proc_cls;
  handle->proc = proc;
  handle->rest_handle = rest_handle;
  handle->zone_pkey = NULL;

  handle->url = GNUNET_strdup(rest_handle->url);
  if (handle->url[strlen(handle->url) - 1] == '/')
    handle->url[strlen(handle->url) - 1] = '\0';
  GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Connecting...\n");

  handle->ns_handle = GNUNET_NAMESTORE_connect(cfg);
  handle->identity_handle =
    GNUNET_IDENTITY_connect(cfg, &id_connect_cb, handle);
  handle->timeout_task =
    GNUNET_SCHEDULER_add_delayed(handle->timeout, &do_error, handle);

  GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Connected\n");
}


void *
libgnunet_plugin_rest_namestore_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_NAMESTORE;
  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);

  GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, _("Namestore REST API initialized\n"));
  return api;
}


void *
libgnunet_plugin_rest_namestore_done(void *cls)
{
  struct GNUNET_REST_Plugin *api = cls;
  struct Plugin *plugin = api->cls;

  plugin->cfg = NULL;

  GNUNET_free_non_null(allow_methods);
  GNUNET_free(api);
  GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Namestore REST plugin is finished\n");
  return NULL;
}

/* end of plugin_rest_namestore.c */