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