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 <vector>
  23 #include <thread>
  24 #include <fcntl.h>
  25 #include <linux/can.h>
  26 #include <json-c/json.h>
  27 #include <systemd/sd-event.h>
  28
  29 #include "timer.hpp"
  30 #include "openxc.pb.h"
  31 #include "can-utils.hpp"
  32 #include "can-signals.hpp"
  33 #include "openxc-utils.hpp"
  34
  35 extern "C"
  36 {
  37         #include <afb/afb-binding.h>
  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  * CAN bus handler pointer. This is the object that will be use to
  48  * initialize each CAN devices specified into the configuration file
  49  *
  50  * It is used by the reading thread also because of its can_message_q_ queue
  51  * that store CAN messages read from the socket.
  52  */
  53 can_bus_t *can_bus_handler;
  54
  55 /********************************************************************************
  56 *
  57 *               Event management
  58 *
  59 *********************************************************************************/
  60 int can_frame_received(sd_event_source *s, int fd, uint32_t revents, void *userdata)
  61 {
  62         can_bus_dev_t *can_bus_dev = (can_bus_dev_t*)userdata;
  63         std::lock_guard<std::mutex> can_frame_lock(can_frame_mutex);
  64
  65         /* Notify reading thread that there is something to read */
  66         if ((revents & EPOLLIN) != 0) {
  67                 new_can_frame.notify_one();
  68         }
  69
  70         /* check if error or hangup */
  71         if ((revents & (EPOLLERR|EPOLLRDHUP|EPOLLHUP)) != 0)
  72         {
  73                 sd_event_source_unref(s);
  74                 can_bus_dev->close();
  75                 can_bus_dev->open();
  76                 can_bus_dev->start_reading(*can_bus_handler);
  77         }
  78
  79         return 0;
  80 }
  81 /********************************************************************************
  82 *
  83 *               Subscription and unsubscription
  84 *
  85 *********************************************************************************/
  86
  87 static int subscribe_unsubscribe_signal(struct afb_req request, bool subscribe, const CanSignal& sig)
  88 {
  89         int ret;
  90
  91         // TODO: lock the subscribed_signals when insert/remove
  92         const auto& ss_i = subscribed_signals.find(sig.genericName);
  93         if (ss_i != subscribed_signals.end())
  94         {
  95                 if(!afb_event_is_valid(ss_i->second))
  96                 {
  97                         if(!subscribe)
  98                         {
  99                                 NOTICE(binder_interface, "Event isn't valid, it can't be unsubscribed.");
 100                                 ret = 1;
 101                         }
 102                         else
 103                         {
 104                                 ss_i->second = afb_daemon_make_event(binder_interface->daemon, ss_i->first.c_str());
 105                                 if (!afb_event_is_valid(ss_i->second))
 106                                 {
 107                                         ERROR(binder_interface, "Can't create an event, something goes wrong.");
 108                                         ret = 0;
 109                                 }
 110                         }
 111                 }
 112         }
 113         else
 114         {
 115                 subscribed_signals[sig.genericName] = afb_daemon_make_event(binder_interface->daemon, sig.genericName);
 116                 if (!afb_event_is_valid(ss_i->second))
 117                 {
 118                         ERROR(binder_interface, "Can't create an event, something goes wrong.");
 119                         ret = 0;
 120                 }
 121         }
 122
 123         if (((subscribe ? afb_req_subscribe : afb_req_unsubscribe)(request, subscribed_signals[sig.genericName])) < 0)
 124         {
 125                 ERROR(binder_interface, "Operation goes wrong for signal: %s", sig.genericName);
 126                 ret = 0;
 127         }
 128         else
 129                 ret = 1;
 130
 131         return ret;
 132 }
 133
 134 static int subscribe_unsubscribe_signals(struct afb_req request, bool subscribe, const std::vector<CanSignal>& signals)
 135 {
 136         int ret = 0;
 137
 138         for(const auto& signal_i : signals)
 139         {
 140                 ret = subscribe_unsubscribe_signal(request, subscribe, signal_i);
 141                 if(ret == 0)
 142                         return ret;
 143         }
 144         return ret;
 145 }
 146
 147 static int subscribe_unsubscribe_all(struct afb_req request, bool subscribe)
 148 {
 149         int e = 0;
 150
 151         //for (const auto& sig : SIGNALS)
 152         //      e += !subscribe_unsubscribe_signals(request, subscribe, sig);
 153         e += !subscribe_unsubscribe_signals(request, subscribe, getSignals());
 154
 155         return e == 0;
 156 }
 157
 158 static int subscribe_unsubscribe_name(struct afb_req request, bool subscribe, const char *name)
 159 {
 160         std::vector<CanSignal> sig;
 161         int ret = 0;
 162
 163         if (!::strcmp(name, "*"))
 164                 ret = subscribe_unsubscribe_all(request, subscribe);
 165         else
 166         {
 167                 //if(obd2_handler_c.is_obd2_signal(name))
 168                 if(false)
 169                 {
 170                 // TODO
 171                 }
 172                 else
 173                 {
 174                         openxc_DynamicField search_key = build_DynamicField(name);
 175                         sig = find_can_signals(search_key);
 176                         if (sig.empty())
 177                                 ret = 0;
 178                 }
 179                 ret = subscribe_unsubscribe_signals(request, subscribe, sig);
 180         }
 181         return ret;
 182 }
 183
 184 static void subscribe_unsubscribe(struct afb_req request, bool subscribe)
 185 {
 186         int ok, i, n;
 187         struct json_object *args, *a, *x;
 188
 189         /* makes the subscription/unsubscription */
 190         args = afb_req_json(request);
 191         if (args == NULL || !json_object_object_get_ex(args, "event", &a)) {
 192                 ok = subscribe_unsubscribe_all(request, subscribe);
 193         } else if (json_object_get_type(a) != json_type_array) {
 194                 ok = subscribe_unsubscribe_name(request, subscribe, json_object_get_string(a));
 195         } else {
 196                 n = json_object_array_length(a);
 197                 ok = 0;
 198                 for (i = 0 ; i < n ; i++) {
 199                         x = json_object_array_get_idx(a, i);
 200                         if (subscribe_unsubscribe_name(request, subscribe, json_object_get_string(x)))
 201                                 ok++;
 202                 }
 203                 ok = (ok == n);
 204         }
 205
 206         /* send the report */
 207         if (ok)
 208                 afb_req_success(request, NULL, NULL);
 209         else
 210                 afb_req_fail(request, "error", NULL);
 211 }
 212
 213 extern "C"
 214 {
 215         static void subscribe(struct afb_req request)
 216         {
 217                 subscribe_unsubscribe(request, true);
 218         }
 219
 220         static void unsubscribe(struct afb_req request)
 221         {
 222                 subscribe_unsubscribe(request, false);
 223         }
 224
 225         static const struct afb_verb_desc_v1 verbs[]=
 226         {
 227                 { .name= "subscribe",   .session= AFB_SESSION_NONE, .callback= subscribe,       .info= "subscribe to notification of CAN bus messages." },
 228                 { .name= "unsubscribe", .session= AFB_SESSION_NONE, .callback= unsubscribe,     .info= "unsubscribe a previous subscription." }
 229         };
 230
 231         static const struct afb_binding binding_desc {
 232                 AFB_BINDING_VERSION_1,
 233                 {
 234                         "CAN bus service",
 235                         "can",
 236                         verbs
 237                 }
 238         };
 239
 240         const struct afb_binding *afbBindingV1Register (const struct afb_binding_interface *itf)
 241         {
 242                 binder_interface = itf;
 243
 244                 return &binding_desc;
 245         }
 246
 247         /**
 248         * @brief Initialize the binding.
 249         *
 250         * @param[in] service Structure which represent the Application Framework Binder.
 251         *
 252         * @return Exit code, zero if success.
 253         */
 254         int afbBindingV1ServiceInit(struct afb_service service)
 255         {
 256                 int fd_conf;
 257                 fd_conf = afb_daemon_rootdir_open_locale(binder_interface->daemon, "can_bus.json", O_RDONLY, NULL);
 258
 259                 /* Initialize the CAN bus handler */
 260                 can_bus_t cbh(fd_conf);
 261                 can_bus_handler = &cbh;
 262
 263                 /* Open CAN socket */
 264                 if(can_bus_handler->init_can_dev() == 0)
 265                 {
 266                         can_bus_handler->start_threads();
 267                         return 0;
 268                 }
 269                 ERROR(binder_interface, "There was something wrong with CAN device Initialization. Check your config file maybe");
 270                 return 1;
 271         }
 272 };