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 "timer.hpp"
  31 #include "openxc.pb.h"
  32 #include "can-utils.hpp"
  33 #include "can-signals.hpp"
  34 #include "openxc-utils.hpp"
  35
  36 extern "C"
  37 {
  38         #include <afb/afb-service-itf.h>
  39 };
  40
  41 /*
  42  *      Interface between the daemon and the binding
  43  */
  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, std::map<std::string, struct afb_event>::iterator& ss_i, bool subscribe)
  53 {
  54         /* Make the subscription or unsubscription to the event */
  55         if (((subscribe ? afb_req_subscribe : afb_req_unsubscribe)(request, ss_i->second)) < 0)
  56         {
  57                 ERROR(binder_interface, "Operation goes wrong for signal: %s", ss_i->first);
  58                 return 0;
  59         }
  60         return 1;
  61
  62 }
  63
  64 static int create_event_handle(std::map<std::string, struct afb_event>::iterator& ss_i)
  65 {
  66         ss_i->second = afb_daemon_make_event(binder_interface->daemon, ss_i->first.c_str());
  67         if (!afb_event_is_valid(ss_i->second))
  68         {
  69                 ERROR(binder_interface, "Can't create an event, something goes wrong.");
  70                 return 0;
  71         }
  72
  73         return 1;
  74 }
  75
  76 static int subscribe_unsubscribe_signal(struct afb_req request, bool subscribe, const CanSignal& sig)
  77 {
  78         int ret;
  79
  80         std::lock_guard<std::mutex> subscribed_signals_lock(subscribed_signals_mutex);
  81         auto ss_i = subscribed_signals.find(sig.genericName);
  82         if (ss_i != subscribed_signals.end() && !afb_event_is_valid(ss_i->second))
  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(ss_i);
  93                 }
  94         }
  95         else
  96         {
  97                 /* Event don't exist , so let's create it */
  98                 struct afb_event empty_event = {nullptr, nullptr};
  99                 auto ss_i = subscribed_signals.insert(std::make_pair(sig.genericName, empty_event));
 100                 ret = create_event_handle(ss_i.first);
 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, ss_i, subscribe);
 109 }
 110
 111 static int subscribe_unsubscribe_signals(struct afb_req request, bool subscribe, const std::vector<CanSignal>& signals)
 112 {
 113         int ret = 0;
 114
 115         for(const auto& signal_i : signals)
 116         {
 117                 ret = subscribe_unsubscribe_signal(request, subscribe, signal_i);
 118                 if(ret == 0)
 119                         return ret;
 120         }
 121         return ret;
 122 }
 123
 124 static int subscribe_unsubscribe_all(struct afb_req request, bool subscribe)
 125 {
 126         int e = 0;
 127
 128         //for (const auto& sig : SIGNALS)
 129         //      e += !subscribe_unsubscribe_signals(request, subscribe, sig);
 130         e += !subscribe_unsubscribe_signals(request, subscribe, getSignals());
 131
 132         return e == 0;
 133 }
 134
 135 static int subscribe_unsubscribe_name(struct afb_req request, bool subscribe, const char *name)
 136 {
 137         std::vector<CanSignal> sig;
 138         int ret = 0;
 139
 140         if (!::strcmp(name, "*"))
 141                 ret = subscribe_unsubscribe_all(request, subscribe);
 142         else
 143         {
 144                 //if(obd2_handler_c.is_obd2_signal(name))
 145                 if(false)
 146                 {
 147                 // TODO
 148                 }
 149                 else
 150                 {
 151                         openxc_DynamicField search_key = build_DynamicField(name);
 152                         sig = find_can_signals(search_key);
 153                         if (sig.empty())
 154                                 ret = 0;
 155                 }
 156                 ret = subscribe_unsubscribe_signals(request, subscribe, sig);
 157         }
 158         return ret;
 159 }
 160
 161 static void subscribe_unsubscribe(struct afb_req request, bool subscribe)
 162 {
 163         int ok, i, n;
 164         struct json_object *args, *a, *x;
 165
 166         /* makes the subscription/unsubscription */
 167         args = afb_req_json(request);
 168         if (args == NULL || !json_object_object_get_ex(args, "event", &a)) {
 169                 ok = subscribe_unsubscribe_all(request, subscribe);
 170         } else if (json_object_get_type(a) != json_type_array) {
 171                 ok = subscribe_unsubscribe_name(request, subscribe, json_object_get_string(a));
 172         } else {
 173                 n = json_object_array_length(a);
 174                 ok = 0;
 175                 for (i = 0 ; i < n ; i++) {
 176                         x = json_object_array_get_idx(a, i);
 177                         if (subscribe_unsubscribe_name(request, subscribe, json_object_get_string(x)))
 178                                 ok++;
 179                 }
 180                 ok = (ok == n);
 181         }
 182
 183         /* send the report */
 184         if (ok)
 185                 afb_req_success(request, NULL, NULL);
 186         else
 187                 afb_req_fail(request, "error", NULL);
 188 }
 189
 190 extern "C"
 191 {
 192         static void subscribe(struct afb_req request)
 193         {
 194                 subscribe_unsubscribe(request, true);
 195         }
 196
 197         static void unsubscribe(struct afb_req request)
 198         {
 199                 subscribe_unsubscribe(request, false);
 200         }
 201
 202         static const struct afb_verb_desc_v1 verbs[]=
 203         {
 204                 { .name= "subscribe",   .session= AFB_SESSION_NONE, .callback= subscribe,       .info= "subscribe to notification of CAN bus messages." },
 205                 { .name= "unsubscribe", .session= AFB_SESSION_NONE, .callback= unsubscribe,     .info= "unsubscribe a previous subscription." }
 206         };
 207
 208         static const struct afb_binding binding_desc {
 209                 AFB_BINDING_VERSION_1,
 210                 {
 211                         "CAN bus service",
 212                         "can",
 213                         verbs
 214                 }
 215         };
 216
 217         const struct afb_binding *afbBindingV1Register (const struct afb_binding_interface *itf)
 218         {
 219                 binder_interface = itf;
 220
 221                 return &binding_desc;
 222         }
 223
 224         /**
 225         * @brief Initialize the binding.
 226         *
 227         * @param[in] service Structure which represent the Application Framework Binder.
 228         *
 229         * @return Exit code, zero if success.
 230         */
 231         int afbBindingV1ServiceInit(struct afb_service service)
 232         {
 233                 int fd_conf;
 234                 fd_conf = afb_daemon_rootdir_open_locale(binder_interface->daemon, "can_bus.json", O_RDONLY, NULL);
 235
 236                 /* Initialize the CAN bus handler */
 237                 can_bus_t can_bus_handler(fd_conf);
 238
 239                 /* Open CAN socket */
 240                 if(can_bus_handler.init_can_dev() == 0)
 241                 {
 242                         can_bus_handler.start_threads();
 243                         return 0;
 244                 }
 245                 ERROR(binder_interface, "There was something wrong with CAN device Initialization. Check your config file maybe");
 246                 return 1;
 247         }
 248 };