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 "configuration.hpp"
  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 configuration_t *config;
  46
  47 /********************************************************************************
  48 *
  49 *               Subscription and unsubscription
  50 *
  51 *********************************************************************************/
  52
  53 static int make_subscription_unsubscription(struct afb_req request, const std::string& sig_name, std::map<std::string, struct afb_event>& s, bool subscribe)
  54 {
  55         /* Make the subscription or unsubscription to the event */
  56         if (((subscribe ? afb_req_subscribe : afb_req_unsubscribe)(request, s[sig_name.c_str()])) < 0)
  57         {
  58                 ERROR(binder_interface, "Operation goes wrong for signal: %s", sig_name);
  59                 return 0;
  60         }
  61         return 1;
  62
  63 }
  64
  65 static int create_event_handle(const std::string& sig_name, std::map<std::string, struct afb_event>& s)
  66 {
  67         s[sig_name] = afb_daemon_make_event(binder_interface->daemon, sig_name.c_str());
  68         if (!afb_event_is_valid(s[sig_name]))
  69         {
  70                 ERROR(binder_interface, "Can't create an event, something goes wrong.");
  71                 return 0;
  72         }
  73         return 1;
  74 }
  75
  76 static int subscribe_unsubscribe_signal(struct afb_req request, bool subscribe, const std::string& sig)
  77 {
  78         int ret;
  79
  80         std::lock_guard<std::mutex> subscribed_signals_lock(get_subscribed_signals_mutex());
  81         std::map<std::string, struct afb_event>& s = get_subscribed_signals();
  82         if (s.find(sig) != s.end() && !afb_event_is_valid(s[sig]))
  83         {
  84                 if(!subscribe)
  85                 {
  86                         NOTICE(binder_interface, "Event isn't valid, it can't be unsubscribed.");
  87                         ret = -1;
  88                 }
  89                 else
  90                 {
  91                         /* Event it isn't valid annymore, recreate it */
  92                         ret = create_event_handle(sig, s);
  93                 }
  94         }
  95         else
  96         {
  97                 /* Event doesn't exist , so let's create it */
  98                 struct afb_event empty_event = {nullptr, nullptr};
  99                 subscribed_signals[sig] = empty_event;
 100                 ret = create_event_handle(sig, s);
 101         }
 102
 103         /* Check whether or not the event handler has been correctly created and
 104          * make the subscription/unsubscription operation is so.
 105          */
 106         if (ret <= 0)
 107                 return ret;
 108         return make_subscription_unsubscription(request, sig, s, subscribe);
 109 }
 110
 111 /**
 112  * @fn static int subscribe_unsubscribe_signals(struct afb_req request, bool subscribe, const std::vector<can_signal_t>& signals)
 113  * @brief subscribe to all signals in the vector signals
 114  *
 115  * @param[in] afb_req request : contain original request use to subscribe or unsubscribe
 116  * @param[in] subscribe boolean value used to chose between a subscription operation or an unsubscription
 117  * @param[in] can_signal_t  vector with can_signal_t to subscribe
 118  *
 119  * @return Number of correctly subscribed signal
 120  */
 121 static int subscribe_unsubscribe_signals(struct afb_req request, bool subscribe, const std::vector<std::string>& signals)
 122 {
 123         int rets = 0;
 124
 125         for(auto& sig : signals)
 126         {
 127                 int ret = subscribe_unsubscribe_signal(request, subscribe, sig);
 128                 if(ret <= 0)
 129                         return ret;
 130                 rets++;
 131                 DEBUG(binder_interface, "Signal: %s subscribed", sig.c_str());
 132         }
 133         return rets;
 134 }
 135
 136 static int subscribe_unsubscribe_name(struct afb_req request, bool subscribe, const char *name)
 137 {
 138         std::vector<std::string> signals;
 139         int ret = 0;
 140
 141         openxc_DynamicField search_key = build_DynamicField(std::string(name));
 142         signals = find_signals(search_key);
 143         if (signals.empty())
 144                 ret = 0;
 145
 146         ret = subscribe_unsubscribe_signals(request, subscribe, signals);
 147         NOTICE(binder_interface, "Subscribed correctly to %d/%d signal(s).", ret, (int)signals.size());
 148
 149         return ret;
 150 }
 151
 152 static void subscribe_unsubscribe(struct afb_req request, bool subscribe)
 153 {
 154         int ok, i, n;
 155         struct json_object *args, *a, *x;
 156
 157         /* makes the subscription/unsubscription */
 158         args = afb_req_json(request);
 159         if (args == NULL || !json_object_object_get_ex(args, "event", &a)) {
 160                 ok = subscribe_unsubscribe_name(request, subscribe, "*");
 161         } else if (json_object_get_type(a) != json_type_array) {
 162                 ok = subscribe_unsubscribe_name(request, subscribe, json_object_get_string(a));
 163         } else {
 164                 n = json_object_array_length(a);
 165                 ok = 0;
 166                 for (i = 0 ; i < n ; i++) {
 167                         x = json_object_array_get_idx(a, i);
 168                         if (subscribe_unsubscribe_name(request, subscribe, json_object_get_string(x)))
 169                                 ok++;
 170                 }
 171                 ok = (ok == n);
 172         }
 173
 174         /* send the report */
 175         if (ok)
 176                 afb_req_success(request, NULL, NULL);
 177         else
 178                 afb_req_fail(request, "error", NULL);
 179 }
 180
 181 extern "C"
 182 {
 183         static void subscribe(struct afb_req request)
 184         {
 185                 subscribe_unsubscribe(request, true);
 186         }
 187
 188         static void unsubscribe(struct afb_req request)
 189         {
 190                 subscribe_unsubscribe(request, false);
 191         }
 192
 193         static const struct afb_verb_desc_v1 verbs[]=
 194         {
 195                 { .name= "subscribe",   .session= AFB_SESSION_NONE, .callback= subscribe,       .info= "subscribe to notification of CAN bus messages." },
 196                 { .name= "unsubscribe", .session= AFB_SESSION_NONE, .callback= unsubscribe,     .info= "unsubscribe a previous subscription." }
 197         };
 198
 199         static const struct afb_binding binding_desc {
 200                 AFB_BINDING_VERSION_1,
 201                 {
 202                         "Low level CAN bus service",
 203                         "low-can",
 204                         verbs
 205                 }
 206         };
 207
 208         const struct afb_binding *afbBindingV1Register (const struct afb_binding_interface *itf)
 209         {
 210                 binder_interface = itf;
 211
 212                 return &binding_desc;
 213         }
 214
 215         /**
 216         * @brief Initialize the binding.
 217         *
 218         * @param[in] service Structure which represent the Application Framework Binder.
 219         *
 220         * @return Exit code, zero if success.
 221         */
 222         int afbBindingV1ServiceInit(struct afb_service service)
 223         {
 224                 config = new configuration_t();
 225
 226                 can_bus_t& can_bus_manager = config->get_can_bus_manager();
 227
 228                 /* Open CAN socket */
 229                 if(can_bus_manager.init_can_dev() == 0)
 230                 {
 231                         can_bus_manager.start_threads();
 232                         return 0;
 233                 }
 234
 235                 ERROR(binder_interface, "There was something wrong with CAN device Initialization. Check your config file maybe");
 236                 return 1;
 237         }
 238 };