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[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                 {
  94                         /* Event it isn't valid annymore, recreate it */
  95                         ret = create_event_handle(sig, s);
  96                 }
  97         }
  98         else
  99         {
 100                 /* Event doesn't exist , so let's create it */
 101                 struct afb_event empty_event = {nullptr, nullptr};
 102                 subscribed_signals[sig] = empty_event;
 103                 ret = create_event_handle(sig, s);
 104         }
 105
 106         /* Check whether or not the event handler has been correctly created and
 107          * make the subscription/unsubscription operation is so.
 108          */
 109         if (ret <= 0)
 110                 return ret;
 111         return make_subscription_unsubscription(request, sig, s, subscribe);
 112 }
 113
 114 /**
 115  * @fn static int subscribe_unsubscribe_signals(struct afb_req request, bool subscribe, const std::vector<CanSignal>& signals)
 116  * @brief subscribe to all signals in the vector signals
 117  *
 118  * @param[in] afb_req request : contain original request use to subscribe or unsubscribe
 119  * @param[in] subscribe boolean value used to chose between a subscription operation or an unsubscription
 120  * @param[in] CanSignal  vector with CanSignal to subscribe
 121  *
 122  * @return Number of correctly subscribed signal
 123  */
 124 static int subscribe_unsubscribe_signals(struct afb_req request, bool subscribe, const std::vector<std::string>& signals)
 125 {
 126         int rets = 0;
 127
 128         for(auto& sig : signals)
 129         {
 130                 int ret = subscribe_unsubscribe_signal(request, subscribe, sig);
 131                 if(ret <= 0)
 132                         return ret;
 133                 rets++;
 134                 DEBUG(binder_interface, "Signal: %s subscribed", sig.c_str());
 135         }
 136         return rets;
 137 }
 138
 139 static int subscribe_unsubscribe_name(struct afb_req request, bool subscribe, const char *name)
 140 {
 141         std::vector<std::string> signals;
 142         int ret = 0;
 143
 144         openxc_DynamicField search_key = build_DynamicField(std::string(name));
 145         signals = find_signals(search_key);
 146         if (signals.empty())
 147                 ret = 0;
 148
 149         ret = subscribe_unsubscribe_signals(request, subscribe, signals);
 150         NOTICE(binder_interface, "Subscribed correctly to %d/%d signal(s).", ret, (int)signals.size());
 151
 152         return ret;
 153 }
 154
 155 static void subscribe_unsubscribe(struct afb_req request, bool subscribe)
 156 {
 157         int ok, i, n;
 158         struct json_object *args, *a, *x;
 159
 160         /* makes the subscription/unsubscription */
 161         args = afb_req_json(request);
 162         if (args == NULL || !json_object_object_get_ex(args, "event", &a)) {
 163                 ok = subscribe_unsubscribe_name(request, subscribe, "*");
 164         } else if (json_object_get_type(a) != json_type_array) {
 165                 ok = subscribe_unsubscribe_name(request, subscribe, json_object_get_string(a));
 166         } else {
 167                 n = json_object_array_length(a);
 168                 ok = 0;
 169                 for (i = 0 ; i < n ; i++) {
 170                         x = json_object_array_get_idx(a, i);
 171                         if (subscribe_unsubscribe_name(request, subscribe, json_object_get_string(x)))
 172                                 ok++;
 173                 }
 174                 ok = (ok == n);
 175         }
 176
 177         /* send the report */
 178         if (ok)
 179                 afb_req_success(request, NULL, NULL);
 180         else
 181                 afb_req_fail(request, "error", NULL);
 182 }
 183
 184 extern "C"
 185 {
 186         static void subscribe(struct afb_req request)
 187         {
 188                 subscribe_unsubscribe(request, true);
 189         }
 190
 191         static void unsubscribe(struct afb_req request)
 192         {
 193                 subscribe_unsubscribe(request, false);
 194         }
 195
 196         static const struct afb_verb_desc_v1 verbs[]=
 197         {
 198                 { .name= "subscribe",   .session= AFB_SESSION_NONE, .callback= subscribe,       .info= "subscribe to notification of CAN bus messages." },
 199                 { .name= "unsubscribe", .session= AFB_SESSION_NONE, .callback= unsubscribe,     .info= "unsubscribe a previous subscription." }
 200         };
 201
 202         static const struct afb_binding binding_desc {
 203                 AFB_BINDING_VERSION_1,
 204                 {
 205                         "Low level CAN bus service",
 206                         "low-can",
 207                         verbs
 208                 }
 209         };
 210
 211         const struct afb_binding *afbBindingV1Register (const struct afb_binding_interface *itf)
 212         {
 213                 binder_interface = itf;
 214
 215                 return &binding_desc;
 216         }
 217
 218         /**
 219         * @brief Initialize the binding.
 220         *
 221         * @param[in] service Structure which represent the Application Framework Binder.
 222         *
 223         * @return Exit code, zero if success.
 224         */
 225         int afbBindingV1ServiceInit(struct afb_service service)
 226         {
 227                 int fd_conf;
 228                 fd_conf = afb_daemon_rootdir_open_locale(binder_interface->daemon, "can_buses.json", O_RDONLY, NULL);
 229
 230                 /* Initialize the CAN bus handler */
 231                 can_bus_handler = new can_bus_t(fd_conf);
 232
 233                 /* Open CAN socket */
 234                 if(can_bus_handler->init_can_dev() == 0)
 235                 {
 236                         can_bus_handler->start_threads();
 237                         return 0;
 238                 }
 239                 ERROR(binder_interface, "There was something wrong with CAN device Initialization. Check your config file maybe");
 240                 return 1;
 241         }
 242 };