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 "openxc.pb.h"
  31 #include "can/can-bus.hpp"
  32 #include "can/can-signals.hpp"
  33 #include "can/can-message.hpp"
  34 #include "utils/timer.hpp"
  35 #include "utils/signals.hpp"
  36 #include "utils/openxc-utils.hpp"
  37
  38 extern "C"
  39 {
  40         #include <afb/afb-service-itf.h>
  41 };
  42
  43 /*
  44  *      Interface between the daemon and the binding
  45  */
  46 const struct afb_binding_interface *binder_interface;
  47
  48 can_bus_t *can_bus_handler;
  49
  50 /********************************************************************************
  51 *
  52 *               Subscription and unsubscription
  53 *
  54 *********************************************************************************/
  55
  56 static int make_subscription_unsubscription(struct afb_req request, const std::string& sig_name, std::map<std::string, struct afb_event>& s, bool subscribe)
  57 {
  58         /* Make the subscription or unsubscription to the event */
  59         if (((subscribe ? afb_req_subscribe : afb_req_unsubscribe)(request, s[sig_name.c_str()])) < 0)
  60         {
  61                 ERROR(binder_interface, "Operation goes wrong for signal: %s", sig_name);
  62                 return 0;
  63         }
  64         return 1;
  65
  66 }
  67
  68 static int create_event_handle(const std::string& sig_name, std::map<std::string, struct afb_event>& s)
  69 {
  70         s[sig_name] = afb_daemon_make_event(binder_interface->daemon, sig_name.c_str());
  71         if (!afb_event_is_valid(s[sig_name]))
  72         {
  73                 ERROR(binder_interface, "Can't create an event, something goes wrong.");
  74                 return 0;
  75         }
  76         return 1;
  77 }
  78
  79 static int subscribe_unsubscribe_signal(struct afb_req request, bool subscribe, const std::string& sig)
  80 {
  81         int ret;
  82
  83         std::lock_guard<std::mutex> subscribed_signals_lock(get_subscribed_signals_mutex());
  84         std::map<std::string, struct afb_event>& s = get_subscribed_signals();
  85         if (s.find(sig) != s.end() && !afb_event_is_valid(s[std::string(sig)]))
  86         {
  87                 if(!subscribe)
  88                 {
  89                         NOTICE(binder_interface, "Event isn't valid, it can't be unsubscribed.");
  90                         ret = -1;
  91                 }
  92                 else
  93                         /* Event it isn't valid annymore, recreate it */
  94                         ret = create_event_handle(sig, s);
  95         }
  96         else
  97         {
  98                 /* Event don't exist , so let's create it */
  99                 struct afb_event empty_event = {nullptr, nullptr};
 100                 subscribed_signals[sig] = empty_event;
 101                 ret = create_event_handle(sig, s);
 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, sig, s, subscribe);
 110 }
 111
 112 /**
 113  * @fn static int subscribe_unsubscribe_signals(struct afb_req request, bool subscribe, const std::vector<CanSignal>& signals)
 114  * @brief subscribe to all signals in the vector signals
 115  *
 116  * @param[in] afb_req request : contain original request use to subscribe or unsubscribe
 117  * @param[in] subscribe boolean value used to chose between a subscription operation or an unsubscription
 118  * @param[in] CanSignal  vector with CanSignal to subscribe
 119  *
 120  * @return Number of correctly subscribed signal
 121  */
 122 static int subscribe_unsubscribe_signals(struct afb_req request, bool subscribe, const std::vector<std::string>& signals)
 123 {
 124         int rets = 0;
 125
 126         for(auto& sig : signals)
 127         {
 128                 int ret = subscribe_unsubscribe_signal(request, subscribe, sig);
 129                 if(ret <= 0)
 130                         return ret;
 131                 rets++;
 132                 DEBUG(binder_interface, "Signal: %s subscribed", sig.c_str());
 133         }
 134         return rets;
 135 }
 136
 137 static int subscribe_unsubscribe_name(struct afb_req request, bool subscribe, const char *name)
 138 {
 139         std::vector<std::string> signals;
 140         int ret = 0;
 141
 142         openxc_DynamicField search_key = build_DynamicField(std::string(name));
 143         signals = find_signals(search_key);
 144         if (signals.empty())
 145                 ret = 0;
 146
 147         ret = subscribe_unsubscribe_signals(request, subscribe, signals);
 148         NOTICE(binder_interface, "Subscribed correctly to %d/%d signal(s).", ret, (int)signals.size());
 149
 150         return ret;
 151 }
 152
 153 static void subscribe_unsubscribe(struct afb_req request, bool subscribe)
 154 {
 155         int ok, i, n;
 156         struct json_object *args, *a, *x;
 157
 158         /* makes the subscription/unsubscription */
 159         args = afb_req_json(request);
 160         if (args == NULL || !json_object_object_get_ex(args, "event", &a)) {
 161                 ok = subscribe_unsubscribe_name(request, subscribe, "*");
 162         } else if (json_object_get_type(a) != json_type_array) {
 163                 ok = subscribe_unsubscribe_name(request, subscribe, json_object_get_string(a));
 164         } else {
 165                 n = json_object_array_length(a);
 166                 ok = 0;
 167                 for (i = 0 ; i < n ; i++) {
 168                         x = json_object_array_get_idx(a, i);
 169                         if (subscribe_unsubscribe_name(request, subscribe, json_object_get_string(x)))
 170                                 ok++;
 171                 }
 172                 ok = (ok == n);
 173         }
 174
 175         /* send the report */
 176         if (ok)
 177                 afb_req_success(request, NULL, NULL);
 178         else
 179                 afb_req_fail(request, "error", NULL);
 180 }
 181
 182 extern "C"
 183 {
 184         static void subscribe(struct afb_req request)
 185         {
 186                 subscribe_unsubscribe(request, true);
 187         }
 188
 189         static void unsubscribe(struct afb_req request)
 190         {
 191                 subscribe_unsubscribe(request, false);
 192         }
 193
 194         static const struct afb_verb_desc_v1 verbs[]=
 195         {
 196                 { .name= "subscribe",   .session= AFB_SESSION_NONE, .callback= subscribe,       .info= "subscribe to notification of CAN bus messages." },
 197                 { .name= "unsubscribe", .session= AFB_SESSION_NONE, .callback= unsubscribe,     .info= "unsubscribe a previous subscription." }
 198         };
 199
 200         static const struct afb_binding binding_desc {
 201                 AFB_BINDING_VERSION_1,
 202                 {
 203                         "Low level CAN bus service",
 204                         "low-can",
 205                         verbs
 206                 }
 207         };
 208
 209         const struct afb_binding *afbBindingV1Register (const struct afb_binding_interface *itf)
 210         {
 211                 binder_interface = itf;
 212
 213                 return &binding_desc;
 214         }
 215
 216         /**
 217         * @brief Initialize the binding.
 218         *
 219         * @param[in] service Structure which represent the Application Framework Binder.
 220         *
 221         * @return Exit code, zero if success.
 222         */
 223         int afbBindingV1ServiceInit(struct afb_service service)
 224         {
 225                 int fd_conf;
 226                 fd_conf = afb_daemon_rootdir_open_locale(binder_interface->daemon, "can_buses.json", O_RDONLY, NULL);
 227
 228                 /* Initialize the CAN bus handler */
 229                 can_bus_handler = new can_bus_t(fd_conf);
 230
 231                 /* Open CAN socket */
 232                 if(can_bus_handler->init_can_dev() == 0)
 233                 {
 234                         can_bus_handler->start_threads();
 235                         return 0;
 236                 }
 237                 ERROR(binder_interface, "There was something wrong with CAN device Initialization. Check your config file maybe");
 238                 return 1;
 239         }
 240 };