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