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 <fcntl.h>
  26 #include <linux/can.h>
  27 #include <json-c/json.h>
  28 #include <systemd/sd-event.h>
  29
  30 #include "openxc.pb.h"
  31 #include "can/can-bus.hpp"
  32 #include "can/can-signals.hpp"
  33 #include "can/can-message.hpp"
  34 #include "utils/timer.hpp"
  35 #include "utils/signals.hpp"
  36 #include "utils/openxc-utils.hpp"
  37
  38 extern "C"
  39 {
  40         #include <afb/afb-service-itf.h>
  41 };
  42
  43 // Interface between the daemon and the binding
  44 const struct afb_binding_interface *binder_interface;
  45
  46 /********************************************************************************
  47 *
  48 *               Subscription and unsubscription
  49 *
  50 *********************************************************************************/
  51
  52 static int make_subscription_unsubscription(struct afb_req request, const std::string& sig_name, std::map<std::string, struct afb_event>& s, bool subscribe)
  53 {
  54         /* Make the subscription or unsubscription to the event */
  55         if (((subscribe ? afb_req_subscribe : afb_req_unsubscribe)(request, s[sig_name.c_str()])) < 0)
  56         {
  57                 ERROR(binder_interface, "Operation goes wrong for signal: %s", sig_name);
  58                 return 0;
  59         }
  60         return 1;
  61
  62 }
  63
  64 static int create_event_handle(const std::string& sig_name, std::map<std::string, struct afb_event>& s)
  65 {
  66         s[sig_name] = afb_daemon_make_event(binder_interface->daemon, sig_name.c_str());
  67         if (!afb_event_is_valid(s[sig_name]))
  68         {
  69                 ERROR(binder_interface, "Can't create an event, something goes wrong.");
  70                 return 0;
  71         }
  72         return 1;
  73 }
  74
  75 static int subscribe_unsubscribe_signal(struct afb_req request, bool subscribe, const std::string& sig)
  76 {
  77         int ret;
  78
  79         std::lock_guard<std::mutex> subscribed_signals_lock(get_subscribed_signals_mutex());
  80         std::map<std::string, struct afb_event>& s = get_subscribed_signals();
  81         if (s.find(sig) != s.end() && !afb_event_is_valid(s[sig]))
  82         {
  83                 if(!subscribe)
  84                 {
  85                         NOTICE(binder_interface, "Event isn't valid, it can't be unsubscribed.");
  86                         ret = -1;
  87                 }
  88                 else
  89                 {
  90                         /* Event it isn't valid annymore, recreate it */
  91                         ret = create_event_handle(sig, s);
  92                 }
  93         }
  94         else
  95         {
  96                 /* Event doesn't exist , so let's create it */
  97                 struct afb_event empty_event = {nullptr, nullptr};
  98                 subscribed_signals[sig] = empty_event;
  99                 ret = create_event_handle(sig, s);
 100         }
 101
 102         /* Check whether or not the event handler has been correctly created and
 103          * make the subscription/unsubscription operation is so.
 104          */
 105         if (ret <= 0)
 106                 return ret;
 107         return make_subscription_unsubscription(request, sig, s, subscribe);
 108 }
 109
 110 /**
 111  * @fn static int subscribe_unsubscribe_signals(struct afb_req request, bool subscribe, const std::vector<CanSignal>& signals)
 112  * @brief subscribe to all signals in the vector signals
 113  *
 114  * @param[in] afb_req request : contain original request use to subscribe or unsubscribe
 115  * @param[in] subscribe boolean value used to chose between a subscription operation or an unsubscription
 116  * @param[in] CanSignal  vector with CanSignal to subscribe
 117  *
 118  * @return Number of correctly subscribed signal
 119  */
 120 static int subscribe_unsubscribe_signals(struct afb_req request, bool subscribe, const std::vector<std::string>& signals)
 121 {
 122         int rets = 0;
 123
 124         for(auto& sig : signals)
 125         {
 126                 int ret = subscribe_unsubscribe_signal(request, subscribe, sig);
 127                 if(ret <= 0)
 128                         return ret;
 129                 rets++;
 130                 DEBUG(binder_interface, "Signal: %s subscribed", sig.c_str());
 131         }
 132         return rets;
 133 }
 134
 135 static int subscribe_unsubscribe_name(struct afb_req request, bool subscribe, const char *name)
 136 {
 137         std::vector<std::string> signals;
 138         int ret = 0;
 139
 140         openxc_DynamicField search_key = build_DynamicField(std::string(name));
 141         signals = find_signals(search_key);
 142         if (signals.empty())
 143                 ret = 0;
 144
 145         ret = subscribe_unsubscribe_signals(request, subscribe, signals);
 146         NOTICE(binder_interface, "Subscribed correctly to %d/%d signal(s).", ret, (int)signals.size());
 147
 148         return ret;
 149 }
 150
 151 static void subscribe_unsubscribe(struct afb_req request, bool subscribe)
 152 {
 153         int ok, i, n;
 154         struct json_object *args, *a, *x;
 155
 156         /* makes the subscription/unsubscription */
 157         args = afb_req_json(request);
 158         if (args == NULL || !json_object_object_get_ex(args, "event", &a)) {
 159                 ok = subscribe_unsubscribe_name(request, subscribe, "*");
 160         } else if (json_object_get_type(a) != json_type_array) {
 161                 ok = subscribe_unsubscribe_name(request, subscribe, json_object_get_string(a));
 162         } else {
 163                 n = json_object_array_length(a);
 164                 ok = 0;
 165                 for (i = 0 ; i < n ; i++) {
 166                         x = json_object_array_get_idx(a, i);
 167                         if (subscribe_unsubscribe_name(request, subscribe, json_object_get_string(x)))
 168                                 ok++;
 169                 }
 170                 ok = (ok == n);
 171         }
 172
 173         /* send the report */
 174         if (ok)
 175                 afb_req_success(request, NULL, NULL);
 176         else
 177                 afb_req_fail(request, "error", NULL);
 178 }
 179
 180 extern "C"
 181 {
 182         static void subscribe(struct afb_req request)
 183         {
 184                 subscribe_unsubscribe(request, true);
 185         }
 186
 187         static void unsubscribe(struct afb_req request)
 188         {
 189                 subscribe_unsubscribe(request, false);
 190         }
 191
 192         static const struct afb_verb_desc_v1 verbs[]=
 193         {
 194                 { .name= "subscribe",   .session= AFB_SESSION_NONE, .callback= subscribe,       .info= "subscribe to notification of CAN bus messages." },
 195                 { .name= "unsubscribe", .session= AFB_SESSION_NONE, .callback= unsubscribe,     .info= "unsubscribe a previous subscription." }
 196         };
 197
 198         static const struct afb_binding binding_desc {
 199                 AFB_BINDING_VERSION_1,
 200                 {
 201                         "Low level CAN bus service",
 202                         "low-can",
 203                         verbs
 204                 }
 205         };
 206
 207         const struct afb_binding *afbBindingV1Register (const struct afb_binding_interface *itf)
 208         {
 209                 binder_interface = itf;
 210
 211                 return &binding_desc;
 212         }
 213
 214         /**
 215         * @brief Initialize the binding.
 216         *
 217         * @param[in] service Structure which represent the Application Framework Binder.
 218         *
 219         * @return Exit code, zero if success.
 220         */
 221         int afbBindingV1ServiceInit(struct afb_service service)
 222         {
 223                 configuration_t config;
 224
 225                 can_bus_manager = config.get_can_bus_manager();
 226
 227                 /* Open CAN socket */
 228                 if(can_bus_manager.init_can_dev() == 0)
 229                 {
 230                         can_bus_manager.start_threads();
 231                         return 0;
 232                 }
 233                 ERROR(binder_interface, "There was something wrong with CAN device Initialization. Check your config file maybe");
 234                 return 1;
 235         }
 236 };