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 *               Subscription and unsubscription
  58 *
  59 *********************************************************************************/
  60
  61 static int make_subscription_unsubscription(struct afb_req request, std::map<std::string, struct afb_event>::iterator& ss_i, bool subscribe)
  62 {
  63         /* Make the subscription or unsubscription to the event */
  64         if (((subscribe ? afb_req_subscribe : afb_req_unsubscribe)(request, ss_i->second)) < 0)
  65         {
  66                 ERROR(binder_interface, "Operation goes wrong for signal: %s", ss_i->first);
  67                 return 0;
  68         }
  69         return 1;
  70
  71 }
  72
  73 static int create_event_handle(std::map<std::string, struct afb_event>::iterator& ss_i)
  74 {
  75         ss_i->second = afb_daemon_make_event(binder_interface->daemon, ss_i->first.c_str());
  76         if (!afb_event_is_valid(ss_i->second))
  77         {
  78                 ERROR(binder_interface, "Can't create an event, something goes wrong.");
  79                 return 0;
  80         }
  81
  82         return 1;
  83 }
  84
  85 static int subscribe_unsubscribe_signal(struct afb_req request, bool subscribe, const CanSignal& sig)
  86 {
  87         int ret;
  88
  89         // TODO: lock the subscribed_signals when insert/remove
  90         auto ss_i = subscribed_signals.find(sig.genericName);
  91         if (ss_i != subscribed_signals.end() && !afb_event_is_valid(ss_i->second))
  92         {
  93                 if(!subscribe)
  94                 {
  95                         NOTICE(binder_interface, "Event isn't valid, it can't be unsubscribed.");
  96                         ret = -1;
  97                 }
  98                 else
  99                 {
 100                         /* Event it isn't valid annymore, recreate it */
 101                         ret = create_event_handle(ss_i);
 102                 }
 103         }
 104         else
 105         {
 106                 /* Event don't exist , so let's create it */
 107                 struct afb_event empty_event = {nullptr, nullptr};
 108                 auto ss_i = subscribed_signals.insert(std::make_pair(sig.genericName, empty_event));
 109                 ret = create_event_handle(ss_i.first);
 110         }
 111
 112         /* Check whether or not the event handler has been correctly created and
 113          * make the subscription/unsubscription operation is so.
 114          */
 115         if (ret <= 0)
 116                 return ret;
 117         return make_subscription_unsubscription(request, ss_i, subscribe);
 118 }
 119
 120 static int subscribe_unsubscribe_signals(struct afb_req request, bool subscribe, const std::vector<CanSignal>& signals)
 121 {
 122         int ret = 0;
 123
 124         for(const auto& signal_i : signals)
 125         {
 126                 ret = subscribe_unsubscribe_signal(request, subscribe, signal_i);
 127                 if(ret == 0)
 128                         return ret;
 129         }
 130         return ret;
 131 }
 132
 133 static int subscribe_unsubscribe_all(struct afb_req request, bool subscribe)
 134 {
 135         int e = 0;
 136
 137         //for (const auto& sig : SIGNALS)
 138         //      e += !subscribe_unsubscribe_signals(request, subscribe, sig);
 139         e += !subscribe_unsubscribe_signals(request, subscribe, getSignals());
 140
 141         return e == 0;
 142 }
 143
 144 static int subscribe_unsubscribe_name(struct afb_req request, bool subscribe, const char *name)
 145 {
 146         std::vector<CanSignal> sig;
 147         int ret = 0;
 148
 149         if (!::strcmp(name, "*"))
 150                 ret = subscribe_unsubscribe_all(request, subscribe);
 151         else
 152         {
 153                 //if(obd2_handler_c.is_obd2_signal(name))
 154                 if(false)
 155                 {
 156                 // TODO
 157                 }
 158                 else
 159                 {
 160                         openxc_DynamicField search_key = build_DynamicField(name);
 161                         sig = find_can_signals(search_key);
 162                         if (sig.empty())
 163                                 ret = 0;
 164                 }
 165                 ret = subscribe_unsubscribe_signals(request, subscribe, sig);
 166         }
 167         return ret;
 168 }
 169
 170 static void subscribe_unsubscribe(struct afb_req request, bool subscribe)
 171 {
 172         int ok, i, n;
 173         struct json_object *args, *a, *x;
 174
 175         /* makes the subscription/unsubscription */
 176         args = afb_req_json(request);
 177         if (args == NULL || !json_object_object_get_ex(args, "event", &a)) {
 178                 ok = subscribe_unsubscribe_all(request, subscribe);
 179         } else if (json_object_get_type(a) != json_type_array) {
 180                 ok = subscribe_unsubscribe_name(request, subscribe, json_object_get_string(a));
 181         } else {
 182                 n = json_object_array_length(a);
 183                 ok = 0;
 184                 for (i = 0 ; i < n ; i++) {
 185                         x = json_object_array_get_idx(a, i);
 186                         if (subscribe_unsubscribe_name(request, subscribe, json_object_get_string(x)))
 187                                 ok++;
 188                 }
 189                 ok = (ok == n);
 190         }
 191
 192         /* send the report */
 193         if (ok)
 194                 afb_req_success(request, NULL, NULL);
 195         else
 196                 afb_req_fail(request, "error", NULL);
 197 }
 198
 199 extern "C"
 200 {
 201         static void subscribe(struct afb_req request)
 202         {
 203                 subscribe_unsubscribe(request, true);
 204         }
 205
 206         static void unsubscribe(struct afb_req request)
 207         {
 208                 subscribe_unsubscribe(request, false);
 209         }
 210
 211         static const struct afb_verb_desc_v1 verbs[]=
 212         {
 213                 { .name= "subscribe",   .session= AFB_SESSION_NONE, .callback= subscribe,       .info= "subscribe to notification of CAN bus messages." },
 214                 { .name= "unsubscribe", .session= AFB_SESSION_NONE, .callback= unsubscribe,     .info= "unsubscribe a previous subscription." }
 215         };
 216
 217         static const struct afb_binding binding_desc {
 218                 AFB_BINDING_VERSION_1,
 219                 {
 220                         "CAN bus service",
 221                         "can",
 222                         verbs
 223                 }
 224         };
 225
 226         const struct afb_binding *afbBindingV1Register (const struct afb_binding_interface *itf)
 227         {
 228                 binder_interface = itf;
 229
 230                 return &binding_desc;
 231         }
 232
 233         /**
 234         * @brief Initialize the binding.
 235         *
 236         * @param[in] service Structure which represent the Application Framework Binder.
 237         *
 238         * @return Exit code, zero if success.
 239         */
 240         int afbBindingV1ServiceInit(struct afb_service service)
 241         {
 242                 int fd_conf;
 243                 fd_conf = afb_daemon_rootdir_open_locale(binder_interface->daemon, "can_bus.json", O_RDONLY, NULL);
 244
 245                 /* Initialize the CAN bus handler */
 246                 can_bus_t cbh(fd_conf);
 247                 can_bus_handler = &cbh;
 248
 249                 /* Open CAN socket */
 250                 if(can_bus_handler->init_can_dev() == 0)
 251                 {
 252                         can_bus_handler->start_threads();
 253                         return 0;
 254                 }
 255                 ERROR(binder_interface, "There was something wrong with CAN device Initialization. Check your config file maybe");
 256                 return 1;
 257         }
 258 };