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 make_subscription_unsubscription(struct afb_req request, std::map<std::string, struct afb_event>::iterator& ss_i, bool subscribe)
  90 {
  91         /* Make the subscription or unsubscription to the event */
  92         if (((subscribe ? afb_req_subscribe : afb_req_unsubscribe)(request, ss_i->second)) < 0)
  93         {
  94                 ERROR(binder_interface, "Operation goes wrong for signal: %s", ss_i->first);
  95                 return 0;
  96         }
  97         return 1;
  98
  99 }
 100
 101 static int create_event_handle(std::map<std::string, struct afb_event>::iterator& ss_i)
 102 {
 103         ss_i->second = afb_daemon_make_event(binder_interface->daemon, ss_i->first.c_str());
 104         if (!afb_event_is_valid(ss_i->second))
 105         {
 106                 ERROR(binder_interface, "Can't create an event, something goes wrong.");
 107                 return 0;
 108         }
 109
 110         return 1;
 111 }
 112
 113 static int subscribe_unsubscribe_signal(struct afb_req request, bool subscribe, const CanSignal& sig)
 114 {
 115         int ret;
 116
 117         // TODO: lock the subscribed_signals when insert/remove
 118         auto ss_i = subscribed_signals.find(sig.genericName);
 119         if (ss_i != subscribed_signals.end() && !afb_event_is_valid(ss_i->second))
 120         {
 121                 if(!subscribe)
 122                 {
 123                         NOTICE(binder_interface, "Event isn't valid, it can't be unsubscribed.");
 124                         ret = -1;
 125                 }
 126                 else
 127                 {
 128                         /* Event it isn't valid annymore, recreate it */
 129                         ret = create_event_handle(ss_i);
 130                 }
 131         }
 132         else
 133         {
 134                 /* Event don't exist , so let's create it */
 135                 struct afb_event empty_event = {nullptr, nullptr};
 136                 auto ss_i = subscribed_signals.insert(std::make_pair(sig.genericName, empty_event));
 137                 ret = create_event_handle(ss_i.first);
 138         }
 139
 140         /* Check whether or not the event handler has been correctly created and
 141          * make the subscription/unsubscription operation is so.
 142          */
 143         if (ret <= 0)
 144                 return ret;
 145         return make_subscription_unsubscription(request, ss_i, subscribe);
 146 }
 147
 148 static int subscribe_unsubscribe_signals(struct afb_req request, bool subscribe, const std::vector<CanSignal>& signals)
 149 {
 150         int ret = 0;
 151
 152         for(const auto& signal_i : signals)
 153         {
 154                 ret = subscribe_unsubscribe_signal(request, subscribe, signal_i);
 155                 if(ret == 0)
 156                         return ret;
 157         }
 158         return ret;
 159 }
 160
 161 static int subscribe_unsubscribe_all(struct afb_req request, bool subscribe)
 162 {
 163         int e = 0;
 164
 165         //for (const auto& sig : SIGNALS)
 166         //      e += !subscribe_unsubscribe_signals(request, subscribe, sig);
 167         e += !subscribe_unsubscribe_signals(request, subscribe, getSignals());
 168
 169         return e == 0;
 170 }
 171
 172 static int subscribe_unsubscribe_name(struct afb_req request, bool subscribe, const char *name)
 173 {
 174         std::vector<CanSignal> sig;
 175         int ret = 0;
 176
 177         if (!::strcmp(name, "*"))
 178                 ret = subscribe_unsubscribe_all(request, subscribe);
 179         else
 180         {
 181                 //if(obd2_handler_c.is_obd2_signal(name))
 182                 if(false)
 183                 {
 184                 // TODO
 185                 }
 186                 else
 187                 {
 188                         openxc_DynamicField search_key = build_DynamicField(name);
 189                         sig = find_can_signals(search_key);
 190                         if (sig.empty())
 191                                 ret = 0;
 192                 }
 193                 ret = subscribe_unsubscribe_signals(request, subscribe, sig);
 194         }
 195         return ret;
 196 }
 197
 198 static void subscribe_unsubscribe(struct afb_req request, bool subscribe)
 199 {
 200         int ok, i, n;
 201         struct json_object *args, *a, *x;
 202
 203         /* makes the subscription/unsubscription */
 204         args = afb_req_json(request);
 205         if (args == NULL || !json_object_object_get_ex(args, "event", &a)) {
 206                 ok = subscribe_unsubscribe_all(request, subscribe);
 207         } else if (json_object_get_type(a) != json_type_array) {
 208                 ok = subscribe_unsubscribe_name(request, subscribe, json_object_get_string(a));
 209         } else {
 210                 n = json_object_array_length(a);
 211                 ok = 0;
 212                 for (i = 0 ; i < n ; i++) {
 213                         x = json_object_array_get_idx(a, i);
 214                         if (subscribe_unsubscribe_name(request, subscribe, json_object_get_string(x)))
 215                                 ok++;
 216                 }
 217                 ok = (ok == n);
 218         }
 219
 220         /* send the report */
 221         if (ok)
 222                 afb_req_success(request, NULL, NULL);
 223         else
 224                 afb_req_fail(request, "error", NULL);
 225 }
 226
 227 extern "C"
 228 {
 229         static void subscribe(struct afb_req request)
 230         {
 231                 subscribe_unsubscribe(request, true);
 232         }
 233
 234         static void unsubscribe(struct afb_req request)
 235         {
 236                 subscribe_unsubscribe(request, false);
 237         }
 238
 239         static const struct afb_verb_desc_v1 verbs[]=
 240         {
 241                 { .name= "subscribe",   .session= AFB_SESSION_NONE, .callback= subscribe,       .info= "subscribe to notification of CAN bus messages." },
 242                 { .name= "unsubscribe", .session= AFB_SESSION_NONE, .callback= unsubscribe,     .info= "unsubscribe a previous subscription." }
 243         };
 244
 245         static const struct afb_binding binding_desc {
 246                 AFB_BINDING_VERSION_1,
 247                 {
 248                         "CAN bus service",
 249                         "can",
 250                         verbs
 251                 }
 252         };
 253
 254         const struct afb_binding *afbBindingV1Register (const struct afb_binding_interface *itf)
 255         {
 256                 binder_interface = itf;
 257
 258                 return &binding_desc;
 259         }
 260
 261         /**
 262         * @brief Initialize the binding.
 263         *
 264         * @param[in] service Structure which represent the Application Framework Binder.
 265         *
 266         * @return Exit code, zero if success.
 267         */
 268         int afbBindingV1ServiceInit(struct afb_service service)
 269         {
 270                 int fd_conf;
 271                 fd_conf = afb_daemon_rootdir_open_locale(binder_interface->daemon, "can_bus.json", O_RDONLY, NULL);
 272
 273                 /* Initialize the CAN bus handler */
 274                 can_bus_t cbh(fd_conf);
 275                 can_bus_handler = &cbh;
 276
 277                 /* Open CAN socket */
 278                 if(can_bus_handler->init_can_dev() == 0)
 279                 {
 280                         can_bus_handler->start_threads();
 281                         return 0;
 282                 }
 283                 ERROR(binder_interface, "There was something wrong with CAN device Initialization. Check your config file maybe");
 284                 return 1;
 285         }
 286 };