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
  64         /* Notify reading thread that there is something to read */
  65         if ((revents & EPOLLIN) != 0) {
  66                 new_can_frame.notify_one();
  67         }
  68
  69         /* check if error or hangup and reopen the socket and event_loop.
  70          * socket is protected by a mutex */
  71         if ((revents & (EPOLLERR|EPOLLRDHUP|EPOLLHUP)) != 0)
  72         {
  73                 std::lock_guard<std::mutex> can_frame_lock(can_frame_mutex);
  74                 sd_event_source_unref(s);
  75                 can_bus_dev->close();
  76                 can_bus_dev->open();
  77                 can_bus_dev->start_reading(*can_bus_handler);
  78                 can_bus_dev->event_loop_connection();
  79         }
  80
  81         return 0;
  82 }
  83 /********************************************************************************
  84 *
  85 *               Subscription and unsubscription
  86 *
  87 *********************************************************************************/
  88
  89 static int subscribe_unsubscribe_signal(struct afb_req request, bool subscribe, const CanSignal& sig)
  90 {
  91         int ret;
  92
  93         // TODO: lock the subscribed_signals when insert/remove
  94         const auto& ss_i = subscribed_signals.find(sig.genericName);
  95         if (ss_i != subscribed_signals.end())
  96         {
  97                 if(!afb_event_is_valid(ss_i->second))
  98                 {
  99                         if(!subscribe)
 100                         {
 101                                 NOTICE(binder_interface, "Event isn't valid, it can't be unsubscribed.");
 102                                 ret = 1;
 103                         }
 104                         else
 105                         {
 106                                 ss_i->second = afb_daemon_make_event(binder_interface->daemon, ss_i->first.c_str());
 107                                 if (!afb_event_is_valid(ss_i->second))
 108                                 {
 109                                         ERROR(binder_interface, "Can't create an event, something goes wrong.");
 110                                         ret = 0;
 111                                 }
 112                         }
 113                 }
 114         }
 115         else
 116         {
 117                 subscribed_signals[sig.genericName] = afb_daemon_make_event(binder_interface->daemon, sig.genericName);
 118                 if (!afb_event_is_valid(ss_i->second))
 119                 {
 120                         ERROR(binder_interface, "Can't create an event, something goes wrong.");
 121                         ret = 0;
 122                 }
 123         }
 124
 125         if (((subscribe ? afb_req_subscribe : afb_req_unsubscribe)(request, subscribed_signals[sig.genericName])) < 0)
 126         {
 127                 ERROR(binder_interface, "Operation goes wrong for signal: %s", sig.genericName);
 128                 ret = 0;
 129         }
 130         else
 131                 ret = 1;
 132
 133         return ret;
 134 }
 135
 136 static int subscribe_unsubscribe_signals(struct afb_req request, bool subscribe, const std::vector<CanSignal>& signals)
 137 {
 138         int ret = 0;
 139
 140         for(const auto& signal_i : signals)
 141         {
 142                 ret = subscribe_unsubscribe_signal(request, subscribe, signal_i);
 143                 if(ret == 0)
 144                         return ret;
 145         }
 146         return ret;
 147 }
 148
 149 static int subscribe_unsubscribe_all(struct afb_req request, bool subscribe)
 150 {
 151         int e = 0;
 152
 153         //for (const auto& sig : SIGNALS)
 154         //      e += !subscribe_unsubscribe_signals(request, subscribe, sig);
 155         e += !subscribe_unsubscribe_signals(request, subscribe, getSignals());
 156
 157         return e == 0;
 158 }
 159
 160 static int subscribe_unsubscribe_name(struct afb_req request, bool subscribe, const char *name)
 161 {
 162         std::vector<CanSignal> sig;
 163         int ret = 0;
 164
 165         if (!::strcmp(name, "*"))
 166                 ret = subscribe_unsubscribe_all(request, subscribe);
 167         else
 168         {
 169                 //if(obd2_handler_c.is_obd2_signal(name))
 170                 if(false)
 171                 {
 172                 // TODO
 173                 }
 174                 else
 175                 {
 176                         openxc_DynamicField search_key = build_DynamicField(name);
 177                         sig = find_can_signals(search_key);
 178                         if (sig.empty())
 179                                 ret = 0;
 180                 }
 181                 ret = subscribe_unsubscribe_signals(request, subscribe, sig);
 182         }
 183         return ret;
 184 }
 185
 186 static void subscribe_unsubscribe(struct afb_req request, bool subscribe)
 187 {
 188         int ok, i, n;
 189         struct json_object *args, *a, *x;
 190
 191         /* makes the subscription/unsubscription */
 192         args = afb_req_json(request);
 193         if (args == NULL || !json_object_object_get_ex(args, "event", &a)) {
 194                 ok = subscribe_unsubscribe_all(request, subscribe);
 195         } else if (json_object_get_type(a) != json_type_array) {
 196                 ok = subscribe_unsubscribe_name(request, subscribe, json_object_get_string(a));
 197         } else {
 198                 n = json_object_array_length(a);
 199                 ok = 0;
 200                 for (i = 0 ; i < n ; i++) {
 201                         x = json_object_array_get_idx(a, i);
 202                         if (subscribe_unsubscribe_name(request, subscribe, json_object_get_string(x)))
 203                                 ok++;
 204                 }
 205                 ok = (ok == n);
 206         }
 207
 208         /* send the report */
 209         if (ok)
 210                 afb_req_success(request, NULL, NULL);
 211         else
 212                 afb_req_fail(request, "error", NULL);
 213 }
 214
 215 extern "C"
 216 {
 217         static void subscribe(struct afb_req request)
 218         {
 219                 subscribe_unsubscribe(request, true);
 220         }
 221
 222         static void unsubscribe(struct afb_req request)
 223         {
 224                 subscribe_unsubscribe(request, false);
 225         }
 226
 227         static const struct afb_verb_desc_v1 verbs[]=
 228         {
 229                 { .name= "subscribe",   .session= AFB_SESSION_NONE, .callback= subscribe,       .info= "subscribe to notification of CAN bus messages." },
 230                 { .name= "unsubscribe", .session= AFB_SESSION_NONE, .callback= unsubscribe,     .info= "unsubscribe a previous subscription." }
 231         };
 232
 233         static const struct afb_binding binding_desc {
 234                 AFB_BINDING_VERSION_1,
 235                 {
 236                         "CAN bus service",
 237                         "can",
 238                         verbs
 239                 }
 240         };
 241
 242         const struct afb_binding *afbBindingV1Register (const struct afb_binding_interface *itf)
 243         {
 244                 binder_interface = itf;
 245
 246                 return &binding_desc;
 247         }
 248
 249         /**
 250         * @brief Initialize the binding.
 251         *
 252         * @param[in] service Structure which represent the Application Framework Binder.
 253         *
 254         * @return Exit code, zero if success.
 255         */
 256         int afbBindingV1ServiceInit(struct afb_service service)
 257         {
 258                 int fd_conf;
 259                 fd_conf = afb_daemon_rootdir_open_locale(binder_interface->daemon, "can_bus.json", O_RDONLY, NULL);
 260
 261                 /* Initialize the CAN bus handler */
 262                 can_bus_t cbh(fd_conf);
 263                 can_bus_handler = &cbh;
 264
 265                 /* Open CAN socket */
 266                 if(can_bus_handler->init_can_dev() == 0)
 267                 {
 268                         can_bus_handler->start_threads();
 269                         return 0;
 270                 }
 271                 ERROR(binder_interface, "There was something wrong with CAN device Initialization. Check your config file maybe");
 272                 return 1;
 273         }
 274 };