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