src/low-can-binding.cpp

   1 /*
   2  * Copyright (C) 2015, 2016 "IoT.bzh"
   3  * Author "Romain Forlot" <romain.forlot@iot.bzh>
   4  * Author "Loic Collignon" <loic.collignon@iot.bzh>
   5  *
   6  * Licensed under the Apache License, Version 2.0 (the "License");
   7  * you may not use this file except in compliance with the License.
   8  * You may obtain a copy of the License at
   9  *
  10  *       http://www.apache.org/licenses/LICENSE-2.0
  11  *
  12  * Unless required by applicable law or agreed to in writing, software
  13  * distributed under the License is distributed on an "AS IS" BASIS,
  14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  15  * See the License for the specific language governing permissions and
  16  * limitations under the License.
  17  */
  18
  19 #include "low-can-binding.hpp"
  20
  21 #include <queue>
  22 #include <mutex>
  23 #include <vector>
  24 #include <thread>
  25 #include <linux/can.h>
  26 #include <json-c/json.h>
  27 #include <systemd/sd-event.h>
  28
  29 #include "openxc.pb.h"
  30 #include "can/can-bus.hpp"
  31 #include "can/can-signals.hpp"
  32 #include "can/can-message.hpp"
  33 #include "utils/timer.hpp"
  34 #include "utils/signals.hpp"
  35 #include "utils/openxc-utils.hpp"
  36
  37 // Interface between the daemon and the binding
  38 const struct afb_binding_interface *binder_interface;
  39 configuration_t *config;
  40
  41 /********************************************************************************
  42 *
  43 *               Subscription and unsubscription
  44 *
  45 *********************************************************************************/
  46
  47 static int make_subscription_unsubscription(struct afb_req request, const std::string& sig_name, std::map<std::string, struct afb_event>& s, bool subscribe)
  48 {
  49         /* Make the subscription or unsubscription to the event */
  50         if (((subscribe ? afb_req_subscribe : afb_req_unsubscribe)(request, s[sig_name.c_str()])) < 0)
  51         {
  52                 ERROR(binder_interface, "Operation goes wrong for signal: %s", sig_name);
  53                 return 0;
  54         }
  55         return 1;
  56
  57 }
  58
  59 static int create_event_handle(const std::string& sig_name, std::map<std::string, struct afb_event>& s)
  60 {
  61         s[sig_name] = afb_daemon_make_event(binder_interface->daemon, sig_name.c_str());
  62         if (!afb_event_is_valid(s[sig_name]))
  63         {
  64                 ERROR(binder_interface, "Can't create an event, something goes wrong.");
  65                 return 0;
  66         }
  67         return 1;
  68 }
  69
  70 static int subscribe_unsubscribe_signal(struct afb_req request, bool subscribe, const std::string& sig)
  71 {
  72         int ret;
  73
  74         std::lock_guard<std::mutex> subscribed_signals_lock(get_subscribed_signals_mutex());
  75         std::map<std::string, struct afb_event>& s = get_subscribed_signals();
  76         if (s.find(sig) != s.end() && !afb_event_is_valid(s[sig]))
  77         {
  78                 if(!subscribe)
  79                 {
  80                         NOTICE(binder_interface, "Event isn't valid, it can't be unsubscribed.");
  81                         ret = -1;
  82                 }
  83                 else
  84                 {
  85                         /* Event it isn't valid annymore, recreate it */
  86                         ret = create_event_handle(sig, s);
  87                 }
  88         }
  89         else
  90         {
  91                 /* Event doesn't exist , so let's create it */
  92                 struct afb_event empty_event = {nullptr, nullptr};
  93                 subscribed_signals[sig] = empty_event;
  94                 ret = create_event_handle(sig, s);
  95         }
  96
  97         /* Check whether or not the event handler has been correctly created and
  98          * make the subscription/unsubscription operation is so.
  99          */
 100         if (ret <= 0)
 101                 return ret;
 102         return make_subscription_unsubscription(request, sig, s, subscribe);
 103 }
 104
 105 /**
 106  * @fn static int subscribe_unsubscribe_signals(struct afb_req request, bool subscribe, const std::vector<CanSignal>& signals)
 107  * @brief subscribe to all signals in the vector signals
 108  *
 109  * @param[in] afb_req request : contain original request use to subscribe or unsubscribe
 110  * @param[in] subscribe boolean value used to chose between a subscription operation or an unsubscription
 111  * @param[in] CanSignal  vector with CanSignal to subscribe
 112  *
 113  * @return Number of correctly subscribed signal
 114  */
 115 static int subscribe_unsubscribe_signals(struct afb_req request, bool subscribe, const std::vector<std::string>& signals)
 116 {
 117         int rets = 0;
 118
 119         for(auto& sig : signals)
 120         {
 121                 int ret = subscribe_unsubscribe_signal(request, subscribe, sig);
 122                 if(ret <= 0)
 123                         return ret;
 124                 rets++;
 125                 DEBUG(binder_interface, "Signal: %s subscribed", sig.c_str());
 126         }
 127         return rets;
 128 }
 129
 130 static int subscribe_unsubscribe_name(struct afb_req request, bool subscribe, const char *name)
 131 {
 132         std::vector<std::string> signals;
 133         int ret = 0;
 134
 135         openxc_DynamicField search_key = build_DynamicField(std::string(name));
 136         signals = find_signals(search_key);
 137         if (signals.empty())
 138                 ret = 0;
 139
 140         ret = subscribe_unsubscribe_signals(request, subscribe, signals);
 141         NOTICE(binder_interface, "Subscribed correctly to %d/%d signal(s).", ret, (int)signals.size());
 142
 143         return ret;
 144 }
 145
 146 static void subscribe_unsubscribe(struct afb_req request, bool subscribe)
 147 {
 148         int ok, i, n;
 149         struct json_object *args, *a, *x;
 150
 151         /* makes the subscription/unsubscription */
 152         args = afb_req_json(request);
 153         if (args == NULL || !json_object_object_get_ex(args, "event", &a)) {
 154                 ok = subscribe_unsubscribe_name(request, subscribe, "*");
 155         } else if (json_object_get_type(a) != json_type_array) {
 156                 ok = subscribe_unsubscribe_name(request, subscribe, json_object_get_string(a));
 157         } else {
 158                 n = json_object_array_length(a);
 159                 ok = 0;
 160                 for (i = 0 ; i < n ; i++) {
 161                         x = json_object_array_get_idx(a, i);
 162                         if (subscribe_unsubscribe_name(request, subscribe, json_object_get_string(x)))
 163                                 ok++;
 164                 }
 165                 ok = (ok == n);
 166         }
 167
 168         /* send the report */
 169         if (ok)
 170                 afb_req_success(request, NULL, NULL);
 171         else
 172                 afb_req_fail(request, "error", NULL);
 173 }
 174
 175 extern "C"
 176 {
 177         static void subscribe(struct afb_req request)
 178         {
 179                 subscribe_unsubscribe(request, true);
 180         }
 181
 182         static void unsubscribe(struct afb_req request)
 183         {
 184                 subscribe_unsubscribe(request, false);
 185         }
 186
 187         static const struct afb_verb_desc_v1 verbs[]=
 188         {
 189                 { .name= "subscribe",   .session= AFB_SESSION_NONE, .callback= subscribe,       .info= "subscribe to notification of CAN bus messages." },
 190                 { .name= "unsubscribe", .session= AFB_SESSION_NONE, .callback= unsubscribe,     .info= "unsubscribe a previous subscription." }
 191         };
 192
 193         static const struct afb_binding binding_desc {
 194                 AFB_BINDING_VERSION_1,
 195                 {
 196                         "Low level CAN bus service",
 197                         "low-can",
 198                         verbs
 199                 }
 200         };
 201
 202         const struct afb_binding *afbBindingV1Register (const struct afb_binding_interface *itf)
 203         {
 204                 binder_interface = itf;
 205
 206                 return &binding_desc;
 207         }
 208
 209         /**
 210         * @brief Initialize the binding.
 211         *
 212         * @param[in] service Structure which represent the Application Framework Binder.
 213         *
 214         * @return Exit code, zero if success.
 215         */
 216         int afbBindingV1ServiceInit(struct afb_service service)
 217         {
 218                 config = new configuration_t();
 219
 220                 can_bus_t can_bus_manager = config->get_can_bus_manager();
 221
 222                 /* Open CAN socket */
 223                 if(can_bus_manager.init_can_dev() == 0)
 224                 {
 225                         can_bus_manager.start_threads();
 226                         return 0;
 227                 }
 228
 229                 ERROR(binder_interface, "There was something wrong with CAN device Initialization. Check your config file maybe");
 230                 return 1;
 231         }
 232 };