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, std::map<std::string, struct afb_event>& s, bool subscribe)
  56 {
  57         /* Make the subscription or unsubscription to the event */
  58         if (((subscribe ? afb_req_subscribe : afb_req_unsubscribe)(request, s[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, std::map<std::string, struct afb_event>& s)
  68 {
  69         s[std::string(sig_name)] = afb_daemon_make_event(binder_interface->daemon, sig_name);
  70         if (!afb_event_is_valid(s[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         std::map<std::string, struct afb_event>& s = get_subscribed_signals();
  84         if (s.find(sig.generic_name) != s.end() && !afb_event_is_valid(s[std::string(sig.generic_name)]))
  85         {
  86                 if(!subscribe)
  87                 {
  88                         NOTICE(binder_interface, "Event isn't valid, it can't be unsubscribed.");
  89                         ret = -1;
  90                 }
  91                 else
  92                         /* Event it isn't valid annymore, recreate it */
  93                         ret = create_event_handle(sig.generic_name, s);
  94         }
  95         else
  96         {
  97                 /* Event don't exist , so let's create it */
  98                 struct afb_event empty_event = {nullptr, nullptr};
  99                 subscribed_signals[sig.generic_name] = empty_event;
 100                 ret = create_event_handle(sig.generic_name, 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.generic_name, s, subscribe);
 109 }
 110
 111 /**
 112  * @fn static int subscribe_unsubscribe_signals(struct afb_req request, bool subscribe, const std::vector<CanSignal>& 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] CanSignal  vector with CanSignal 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<CanSignal>& signals)
 122 {
 123         int rets = 0;
 124
 125         for(const auto& signal_i : signals)
 126         {
 127                 int ret = subscribe_unsubscribe_signal(request, subscribe, signal_i);
 128                 if(ret <= 0)
 129                         return ret;
 130                 rets++;
 131                 DEBUG(binder_interface, "Signal: %s subscribed", signal_i.generic_name);
 132         }
 133         return rets;
 134 }
 135
 136 // TODO
 137 static int subscribe_unsubscribe_all(struct afb_req request, bool subscribe)
 138 {
 139         int e = 0;
 140
 141         //for (const auto& sig : SIGNALS)
 142         //      e += !subscribe_unsubscribe_signals(request, subscribe, sig);
 143         e += !subscribe_unsubscribe_signals(request, subscribe, getSignals());
 144
 145         return e == 0;
 146 }
 147
 148 static int subscribe_unsubscribe_name(struct afb_req request, bool subscribe, const char *name)
 149 {
 150         std::vector<CanSignal> sig;
 151         int ret = 0;
 152
 153         if (!::strcmp(name, "*"))
 154                 ret = subscribe_unsubscribe_all(request, subscribe);
 155         else
 156         {
 157                 //if(obd2_handler_c.is_obd2_signal(name))
 158                 if(false)
 159                 {
 160                 // TODO
 161                 }
 162                 else
 163                 {
 164                         openxc_DynamicField search_key = build_DynamicField(std::string(name));
 165                         sig = find_can_signals(search_key);
 166                         if (sig.empty())
 167                                 ret = 0;
 168                 }
 169                 ret = subscribe_unsubscribe_signals(request, subscribe, sig);
 170                 NOTICE(binder_interface, "Subscribed correctly to %d/%d signal(s).", ret, (int)sig.size());
 171         }
 172         return ret;
 173 }
 174
 175 static void subscribe_unsubscribe(struct afb_req request, bool subscribe)
 176 {
 177         int ok, i, n;
 178         struct json_object *args, *a, *x;
 179
 180         /* makes the subscription/unsubscription */
 181         args = afb_req_json(request);
 182         if (args == NULL || !json_object_object_get_ex(args, "event", &a)) {
 183                 ok = subscribe_unsubscribe_all(request, subscribe);
 184         } else if (json_object_get_type(a) != json_type_array) {
 185                 ok = subscribe_unsubscribe_name(request, subscribe, json_object_get_string(a));
 186         } else {
 187                 n = json_object_array_length(a);
 188                 ok = 0;
 189                 for (i = 0 ; i < n ; i++) {
 190                         x = json_object_array_get_idx(a, i);
 191                         if (subscribe_unsubscribe_name(request, subscribe, json_object_get_string(x)))
 192                                 ok++;
 193                 }
 194                 ok = (ok == n);
 195         }
 196
 197         /* send the report */
 198         if (ok)
 199                 afb_req_success(request, NULL, NULL);
 200         else
 201                 afb_req_fail(request, "error", NULL);
 202 }
 203
 204 extern "C"
 205 {
 206         static void subscribe(struct afb_req request)
 207         {
 208                 subscribe_unsubscribe(request, true);
 209         }
 210
 211         static void unsubscribe(struct afb_req request)
 212         {
 213                 subscribe_unsubscribe(request, false);
 214         }
 215
 216         static const struct afb_verb_desc_v1 verbs[]=
 217         {
 218                 { .name= "subscribe",   .session= AFB_SESSION_NONE, .callback= subscribe,       .info= "subscribe to notification of CAN bus messages." },
 219                 { .name= "unsubscribe", .session= AFB_SESSION_NONE, .callback= unsubscribe,     .info= "unsubscribe a previous subscription." }
 220         };
 221
 222         static const struct afb_binding binding_desc {
 223                 AFB_BINDING_VERSION_1,
 224                 {
 225                         "Low level CAN bus service",
 226                         "low-can",
 227                         verbs
 228                 }
 229         };
 230
 231         const struct afb_binding *afbBindingV1Register (const struct afb_binding_interface *itf)
 232         {
 233                 binder_interface = itf;
 234
 235                 return &binding_desc;
 236         }
 237
 238         /**
 239         * @brief Initialize the binding.
 240         *
 241         * @param[in] service Structure which represent the Application Framework Binder.
 242         *
 243         * @return Exit code, zero if success.
 244         */
 245         int afbBindingV1ServiceInit(struct afb_service service)
 246         {
 247                 int fd_conf;
 248                 fd_conf = afb_daemon_rootdir_open_locale(binder_interface->daemon, "can_buses.json", O_RDONLY, NULL);
 249
 250                 /* Initialize the CAN bus handler */
 251                 can_bus_handler = new can_bus_t(fd_conf);
 252
 253                 /* Open CAN socket */
 254                 if(can_bus_handler->init_can_dev() == 0)
 255                 {
 256                         can_bus_handler->start_threads();
 257                         return 0;
 258                 }
 259                 ERROR(binder_interface, "There was something wrong with CAN device Initialization. Check your config file maybe");
 260                 return 1;
 261         }
 262 };