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