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-bus.hpp"
  33 #include "can-signals.hpp"
  34 #include "can-message.hpp"
  35 #include "openxc-utils.hpp"
  36
  37 extern "C"
  38 {
  39         #include <afb/afb-service-itf.h>
  40 };
  41
  42 /*
  43  *      Interface between the daemon and the binding
  44  */
  45 const struct afb_binding_interface *binder_interface;
  46
  47 can_bus_t *can_bus_handler;
  48
  49 /********************************************************************************
  50 *
  51 *               Subscription and unsubscription
  52 *
  53 *********************************************************************************/
  54
  55 static int make_subscription_unsubscription(struct afb_req request, std::map<std::string, struct afb_event>::iterator& ss_i, bool subscribe)
  56 {
  57         /* Make the subscription or unsubscription to the event */
  58         if (((subscribe ? afb_req_subscribe : afb_req_unsubscribe)(request, ss_i->second)) < 0)
  59         {
  60                 ERROR(binder_interface, "Operation goes wrong for signal: %s", ss_i->first);
  61                 return 0;
  62         }
  63         return 1;
  64
  65 }
  66
  67 static int create_event_handle(std::map<std::string, struct afb_event>::iterator& ss_i)
  68 {
  69         ss_i->second = afb_daemon_make_event(binder_interface->daemon, ss_i->first.c_str());
  70         if (!afb_event_is_valid(ss_i->second))
  71         {
  72                 ERROR(binder_interface, "Can't create an event, something goes wrong.");
  73                 return 0;
  74         }
  75
  76         return 1;
  77 }
  78
  79 static int subscribe_unsubscribe_signal(struct afb_req request, bool subscribe, const CanSignal& sig)
  80 {
  81         int ret;
  82
  83         std::lock_guard<std::mutex> subscribed_signals_lock(get_subscribed_signals_mutex());
  84         auto ss_i = subscribed_signals.find(sig.genericName);
  85         if (ss_i != subscribed_signals.end() && !afb_event_is_valid(ss_i->second))
  86         {
  87                 if(!subscribe)
  88                 {
  89                         NOTICE(binder_interface, "Event isn't valid, it can't be unsubscribed.");
  90                         ret = -1;
  91                 }
  92                 else
  93                 {
  94                         /* Event it isn't valid annymore, recreate it */
  95                         ret = create_event_handle(ss_i);
  96                 }
  97         }
  98         else
  99         {
 100                 /* Event don't exist , so let's create it */
 101                 struct afb_event empty_event = {nullptr, nullptr};
 102                 auto ss_i = subscribed_signals.insert(std::make_pair(sig.genericName, empty_event));
 103                 ret = create_event_handle(ss_i.first);
 104         }
 105
 106         /* Check whether or not the event handler has been correctly created and
 107          * make the subscription/unsubscription operation is so.
 108          */
 109         if (ret <= 0)
 110                 return ret;
 111         return make_subscription_unsubscription(request, ss_i, subscribe);
 112 }
 113
 114 static int subscribe_unsubscribe_signals(struct afb_req request, bool subscribe, const std::vector<CanSignal>& signals)
 115 {
 116         int ret = 0;
 117
 118         for(const auto& signal_i : signals)
 119         {
 120                 ret = subscribe_unsubscribe_signal(request, subscribe, signal_i);
 121                 if(ret == 0)
 122                         return ret;
 123         }
 124         return ret;
 125 }
 126
 127 static int subscribe_unsubscribe_all(struct afb_req request, bool subscribe)
 128 {
 129         int e = 0;
 130
 131         //for (const auto& sig : SIGNALS)
 132         //      e += !subscribe_unsubscribe_signals(request, subscribe, sig);
 133         e += !subscribe_unsubscribe_signals(request, subscribe, getSignals());
 134
 135         return e == 0;
 136 }
 137
 138 static int subscribe_unsubscribe_name(struct afb_req request, bool subscribe, const char *name)
 139 {
 140         std::vector<CanSignal> sig;
 141         int ret = 0;
 142
 143         if (!::strcmp(name, "*"))
 144                 ret = subscribe_unsubscribe_all(request, subscribe);
 145         else
 146         {
 147                 //if(obd2_handler_c.is_obd2_signal(name))
 148                 if(false)
 149                 {
 150                 // TODO
 151                 }
 152                 else
 153                 {
 154                         openxc_DynamicField search_key = build_DynamicField(name);
 155                         sig = find_can_signals(search_key);
 156                         if (sig.empty())
 157                                 ret = 0;
 158                 }
 159                 ret = subscribe_unsubscribe_signals(request, subscribe, sig);
 160         }
 161         return ret;
 162 }
 163
 164 static void subscribe_unsubscribe(struct afb_req request, bool subscribe)
 165 {
 166         int ok, i, n;
 167         struct json_object *args, *a, *x;
 168
 169         /* makes the subscription/unsubscription */
 170         args = afb_req_json(request);
 171         if (args == NULL || !json_object_object_get_ex(args, "event", &a)) {
 172                 ok = subscribe_unsubscribe_all(request, subscribe);
 173         } else if (json_object_get_type(a) != json_type_array) {
 174                 ok = subscribe_unsubscribe_name(request, subscribe, json_object_get_string(a));
 175         } else {
 176                 n = json_object_array_length(a);
 177                 ok = 0;
 178                 for (i = 0 ; i < n ; i++) {
 179                         x = json_object_array_get_idx(a, i);
 180                         if (subscribe_unsubscribe_name(request, subscribe, json_object_get_string(x)))
 181                                 ok++;
 182                 }
 183                 ok = (ok == n);
 184         }
 185
 186         /* send the report */
 187         if (ok)
 188                 afb_req_success(request, NULL, NULL);
 189         else
 190                 afb_req_fail(request, "error", NULL);
 191 }
 192
 193 extern "C"
 194 {
 195         static void subscribe(struct afb_req request)
 196         {
 197                 subscribe_unsubscribe(request, true);
 198         }
 199
 200         static void unsubscribe(struct afb_req request)
 201         {
 202                 subscribe_unsubscribe(request, false);
 203         }
 204
 205         static const struct afb_verb_desc_v1 verbs[]=
 206         {
 207                 { .name= "subscribe",   .session= AFB_SESSION_NONE, .callback= subscribe,       .info= "subscribe to notification of CAN bus messages." },
 208                 { .name= "unsubscribe", .session= AFB_SESSION_NONE, .callback= unsubscribe,     .info= "unsubscribe a previous subscription." }
 209         };
 210
 211         static const struct afb_binding binding_desc {
 212                 AFB_BINDING_VERSION_1,
 213                 {
 214                         "Low level CAN bus service",
 215                         "low-can",
 216                         verbs
 217                 }
 218         };
 219
 220         const struct afb_binding *afbBindingV1Register (const struct afb_binding_interface *itf)
 221         {
 222                 binder_interface = itf;
 223
 224                 return &binding_desc;
 225         }
 226
 227         /**
 228         * @brief Initialize the binding.
 229         *
 230         * @param[in] service Structure which represent the Application Framework Binder.
 231         *
 232         * @return Exit code, zero if success.
 233         */
 234         int afbBindingV1ServiceInit(struct afb_service service)
 235         {
 236                 int fd_conf;
 237                 fd_conf = afb_daemon_rootdir_open_locale(binder_interface->daemon, "can_buses.json", O_RDONLY, NULL);
 238
 239                 /* Initialize the CAN bus handler */
 240                 can_bus_handler = new can_bus_t(fd_conf);
 241
 242                 /* Open CAN socket */
 243                 if(can_bus_handler->init_can_dev() == 0)
 244                 {
 245                         can_bus_handler->start_threads();
 246                         return 0;
 247                 }
 248                 ERROR(binder_interface, "There was something wrong with CAN device Initialization. Check your config file maybe");
 249                 return 1;
 250         }
 251 };