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 <json-c/json.h>
  20 #include <systemd/sd-event.h>
  21
  22 #include "low-can-binding.hpp"
  23
  24 #include "can-utils.hpp"
  25 #include "can-signals.hpp"
  26 #include "openxc-utils.hpp"
  27
  28 extern "C"
  29 {
  30         #include <afb/afb-binding.h>
  31         #include <afb/afb-service-itf.h>
  32 };
  33
  34 /*
  35  *      Interface between the daemon and the binding
  36  */
  37 const struct afb_binding_interface *binder_interface;
  38
  39 /********************************************************************************
  40 *
  41 *               Event management
  42 *
  43 *********************************************************************************/
  44
  45 /********************************************************************************
  46 *
  47 *               Subscription and unsubscription
  48 *
  49 *********************************************************************************/
  50
  51 static int subscribe_unsubscribe_signal(struct afb_req request, bool subscribe, const CanSignal& sig)
  52 {
  53         int ret;
  54
  55         // TODO: lock the subscribed_signals when insert/remove
  56         const auto& ss_i = subscribed_signals.find(sig.genericName);
  57         if (ss_i != subscribed_signals.end())
  58         {
  59                 if(!afb_event_is_valid(ss_i->second))
  60                 {
  61                         if(!subscribe)
  62                         {
  63                                 NOTICE(binder_interface, "Event isn't valid, it can't be unsubscribed.");
  64                                 ret = 1;
  65                         }
  66                         else
  67                         {
  68                                 ss_i->second = afb_daemon_make_event(binder_interface->daemon, ss_i->first.c_str());
  69                                 if (!afb_event_is_valid(ss_i->second))
  70                                 {
  71                                         ERROR(binder_interface, "Can't create an event, something goes wrong.");
  72                                         ret = 0;
  73                                 }
  74                         }
  75                 }
  76         }
  77         else
  78         {
  79                 subscribed_signals[sig.genericName] = afb_daemon_make_event(binder_interface->daemon, sig.genericName);
  80                 if (!afb_event_is_valid(ss_i->second))
  81                 {
  82                         ERROR(binder_interface, "Can't create an event, something goes wrong.");
  83                         ret = 0;
  84                 }
  85         }
  86
  87         if (((subscribe ? afb_req_subscribe : afb_req_unsubscribe)(request, subscribed_signals[sig.genericName])) < 0)
  88         {
  89                 ERROR(binder_interface, "Operation goes wrong for signal: %s", sig.genericName);
  90                 ret = 0;
  91         }
  92         else
  93                 ret = 1;
  94
  95         return ret;
  96 }
  97
  98 static int subscribe_unsubscribe_signals(struct afb_req request, bool subscribe, const std::vector<CanSignal>& signals)
  99 {
 100         int ret = 0;
 101
 102         for(const auto& signal_i : signals)
 103         {
 104                 ret = subscribe_unsubscribe_signal(request, subscribe, signal_i);
 105                 if(ret == 0)
 106                         return ret;
 107         }
 108         return ret;
 109 }
 110
 111 static int subscribe_unsubscribe_all(struct afb_req request, bool subscribe)
 112 {
 113         int e = 0;
 114
 115         //for (const auto& sig : SIGNALS)
 116         //      e += !subscribe_unsubscribe_signals(request, subscribe, sig);
 117         e += !subscribe_unsubscribe_signals(request, subscribe, getSignals());
 118
 119         return e == 0;
 120 }
 121
 122 static int subscribe_unsubscribe_name(struct afb_req request, bool subscribe, const char *name)
 123 {
 124         std::vector<CanSignal> sig;
 125         int ret = 0;
 126
 127         if (!::strcmp(name, "*"))
 128                 ret = subscribe_unsubscribe_all(request, subscribe);
 129         else
 130         {
 131                 //if(obd2_handler_c.is_obd2_signal(name))
 132                 if(false)
 133                 {
 134                 // TODO
 135                 }
 136                 else
 137                 {
 138                         openxc_DynamicField search_key = build_DynamicField(name);
 139                         sig = find_can_signals(binder_interface, search_key);
 140                         if (sig.empty())
 141                                 ret = 0;
 142                 }
 143                 ret = subscribe_unsubscribe_signals(request, subscribe, sig);
 144         }
 145         return ret;
 146 }
 147
 148 static void subscribe_unsubscribe(struct afb_req request, bool subscribe)
 149 {
 150         int ok, i, n;
 151         struct json_object *args, *a, *x;
 152
 153         /* makes the subscription/unsubscription */
 154         args = afb_req_json(request);
 155         if (args == NULL || !json_object_object_get_ex(args, "event", &a)) {
 156                 ok = subscribe_unsubscribe_all(request, subscribe);
 157         } else if (json_object_get_type(a) != json_type_array) {
 158                 ok = subscribe_unsubscribe_name(request, subscribe, json_object_get_string(a));
 159         } else {
 160                 n = json_object_array_length(a);
 161                 ok = 0;
 162                 for (i = 0 ; i < n ; i++) {
 163                         x = json_object_array_get_idx(a, i);
 164                         if (subscribe_unsubscribe_name(request, subscribe, json_object_get_string(x)))
 165                                 ok++;
 166                 }
 167                 ok = (ok == n);
 168         }
 169
 170         /* send the report */
 171         if (ok)
 172                 afb_req_success(request, NULL, NULL);
 173         else
 174                 afb_req_fail(request, "error", NULL);
 175 }
 176
 177 extern "C"
 178 {
 179         static void subscribe(struct afb_req request)
 180         {
 181                 subscribe_unsubscribe(request, true);
 182         }
 183
 184         static void unsubscribe(struct afb_req request)
 185         {
 186                 subscribe_unsubscribe(request, false);
 187         }
 188
 189         static const struct afb_verb_desc_v1 verbs[]=
 190         {
 191                 { .name= "subscribe",   .session= AFB_SESSION_NONE, .callback= subscribe,       .info= "subscribe to notification of CAN bus messages." },
 192                 { .name= "unsubscribe", .session= AFB_SESSION_NONE, .callback= unsubscribe,     .info= "unsubscribe a previous subscription." }
 193         };
 194
 195         static const struct afb_binding binding_desc {
 196                 AFB_BINDING_VERSION_1,
 197                 {
 198                         "CAN bus service",
 199                         "can",
 200                         verbs
 201                 }
 202         };
 203
 204         const struct afb_binding *afbBindingV1Register (const struct afb_binding_interface *itf)
 205         {
 206                 binder_interface = itf;
 207
 208                 return &binding_desc;
 209         }
 210
 211         /**
 212         * @brief Initialize the binding.
 213         *
 214         * @param[in] service Structure which represent the Application Framework Binder.
 215         *
 216         * @return Exit code, zero if success.
 217         */
 218         int afbBindingV1ServiceInit(struct afb_service service)
 219         {
 220                 int fd_conf;
 221                 fd_conf = afb_daemon_rootdir_open_locale(binder_interface->daemon, "can_bus.json", O_RDONLY, NULL);
 222
 223                 /* Open CAN socket */
 224                 can_bus_t can_bus_handler(binder_interface, fd_conf);
 225                 if(can_bus_handler.init_can_dev() == 0)
 226                 {
 227                         can_bus_handler.start_threads();
 228                         return 0;
 229                 }
 230
 231                 return 1;
 232         }
 233 };