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 <unistd.h>
  20 #include <sys/types.h>
  21 #include <sys/socket.h>
  22 #include <sys/ioctl.h>
  23 #include <net/if.h>
  24 #include <linux/can.h>
  25 #include <linux/can/raw.h>
  26 #include <fcntl.h>
  27 #include <systemd/sd-event.h>
  28 #include <errno.h>
  29 #include <vector>
  30 #include <map>
  31 #include <queue>
  32 #include <string>
  33 #include <functional>
  34 #include <memory>
  35 #include <thread>
  36
  37 #include <json-c/json.h>
  38 #include <openxc.pb.h>
  39
  40 #include <afb/afb-binding.h>
  41 #include <afb/afb-service-itf.h>
  42
  43 #include "obd2.hpp"
  44
  45 /*
  46  *       Interface between the daemon and the binding
  47  */
  48 static const struct afb_binding_interface *interface;
  49
  50 /********************************************************************************
  51 *
  52 *               Event management
  53 *
  54 *********************************************************************************/
  55
  56 /*
  57  * TBF TBF TBF
  58  * called on an event on the CAN bus
  59  */
  60 static int on_event(sd_event_source *s, int fd, uint32_t revents, void *userdata)
  61 {
  62         openxc_CanMessage can_message;
  63
  64         can_message = openxc_CanMessage_init_default;
  65
  66         /* read available data */
  67         if ((revents & EPOLLIN) != 0)
  68         {
  69                 read_can(&can_message);
  70                 send_event();
  71         }
  72
  73         /* check if error or hangup */
  74         if ((revents & (EPOLLERR|EPOLLRDHUP|EPOLLHUP)) != 0)
  75         {
  76                 sd_event_source_unref(s);
  77                 close(fd);
  78                 connect_to_event_loop();
  79         }
  80
  81         return 0;
  82 }
  83
  84 /*
  85  * USELESS SINCE THREADS SEPARATION
  86  *
  87  * Get the event loop running.
  88  * Will trigger on_event function on EPOLLIN event on socket
  89  *
  90  * Return 0 or positive value on success. Else negative value for failure.
  91 static int connect_to_event_loop(CanBus &CanBus_handler)
  92 {
  93         sd_event *event_loop;
  94         sd_event_source *source;
  95         int rc;
  96
  97         if (CanBus_handler.socket < 0)
  98         {
  99                 return CanBus_handler.socket;
 100         }
 101
 102         event_loop = afb_daemon_get_event_loop(interface->daemon);
 103         rc = sd_event_add_io(event_loop, &source, CanBus_handler.socket, EPOLLIN, on_event, NULL);
 104         if (rc < 0)
 105         {
 106                 CanBus_handler.close();
 107                 ERROR(interface, "Can't connect CAN bus %s to the event loop", CanBus_handler.device);
 108         } else
 109         {
 110                 NOTICE(interface, "Connected CAN bus %s to the event loop", CanBus_handler.device);
 111         }
 112
 113         return rc;
 114 }
 115  */
 116
 117 /********************************************************************************
 118 *
 119 *               Subscription and unsubscription
 120 *
 121 *********************************************************************************/
 122
 123 static int subscribe_unsubscribe_signal(struct afb_req request, int subscribe, std::map<CanSignal, struct afb_event>::iterator *s_sig)
 124  {
 125         if (!afb_event_is_valid(s_sig->second)) {
 126                 if (!subscribe)
 127                         return 1;
 128                 sig->event = afb_daemon_make_event(afbitf->daemon, s_sig->first->genericName);
 129                 if (!afb_event_is_valid(s_sig->second)) {
 130                         return 0;
 131                 }
 132         }
 133
 134         if (((subscribe ? afb_req_subscribe : afb_req_unsubscribe)(request, s_sig->second)) < 0) {
 135                 return 0;
 136         }
 137
 138         return 1;
 139  }
 140
 141 static int subscribe_unsubscribe_signals(struct afb_req request, int subscribe, std:vector<CanSignal> *signals)
 142 {
 143         std::vector<CanSignal>::iterator signal_i;
 144         std::map <CanSignal, struct afb_event>::iterator s_signal_i;
 145
 146         for(signal_i=signals.begin(); signal_i != signals.end(); signal_i++)
 147         {
 148                 s_signal_i = subscribed_signals.find(signal_i);
 149                 if(s_signal_i != subscribed_signals.end())
 150                         subscribe_unsubscribe_signal(request, subscribe, s_signal_i);
 151                 else
 152                 {
 153                         std::map <CanSignal, struct afb_event>::iterator it = subscribed_signals.begin();
 154                         it = subscribed_signals.insert(it, std::pair<CanSignal, struct afb_event>(signal_i, NULL);
 155                         subscribe_unsubscribe_signal(request, subscribe, it);
 156                 }
 157                 return 0;
 158         }
 159 }
 160
 161 static int subscribe_unsubscribe_all(struct afb_req request, int subscribe)
 162 {
 163         int i, n, e;
 164
 165         n = sizeof OBD2_PIDS / sizeof * OBD2_PIDS;
 166         e = 0;
 167         for (i = 0 ; i < n ; i++)
 168                 e += !subscribe_unsubscribe_sig(request, subscribe, &OBD2_PIDS[i]);
 169         return e == 0;
 170 }
 171
 172 static int subscribe_unsubscribe_name(struct afb_req request, int subscribe, const char *name)
 173 {
 174          std::vector <CanSignal> *sig;
 175
 176         if (0 == strcmp(name, "*"))
 177                 return subscribe_unsubscribe_all(request, subscribe);
 178
 179         if(obd2_handler_c.is_obd2_signal(name))
 180
 181         else
 182                 find_can_signals(name, sig);
 183         if (sig == NULL) {
 184                 return 0;
 185         }
 186
 187         return subscribe_unsubscribe_sig(request, subscribe, sig);
 188 }
 189
 190 static void subscribe_unsubscribe(struct afb_req request, int subscribe)
 191 {
 192         int ok, i, n;
 193         struct json_object *args, *a, *x;
 194
 195         /* makes the subscription/unsubscription */
 196         args = afb_req_json(request);
 197         if (args == NULL || !json_object_object_get_ex(args, "event", &a)) {
 198                 ok = subscribe_unsubscribe_all(request, subscribe);
 199         } else if (json_object_get_type(a) != json_type_array) {
 200                 ok = subscribe_unsubscribe_name(request, subscribe, json_object_get_string(a));
 201         } else {
 202                 n = json_object_array_length(a);
 203                 ok = 0;
 204                 for (i = 0 ; i < n ; i++) {
 205                         x = json_object_array_get_idx(a, i);
 206                         if (subscribe_unsubscribe_name(request, subscribe, json_object_get_string(x)))
 207                                 ok++;
 208                 }
 209                 ok = (ok == n);
 210         }
 211
 212         /* send the report */
 213         if (ok)
 214                 afb_req_success(request, NULL, NULL);
 215         else
 216                 afb_req_fail(request, "error", NULL);
 217 }
 218
 219 static void subscribe(struct afb_req request)
 220 {
 221         subscribe_unsubscribe(request, 1);
 222 }
 223
 224 static void unsubscribe(struct afb_req request)
 225 {
 226         subscribe_unsubscribe(request, 0);
 227 }
 228 static const struct afb_verb_desc_v1 verbs[]=
 229 {
 230   { .name= "subscribe",    .session= AFB_SESSION_NONE, .callback= subscribe,    .info= "subscribe to notification of CAN bus messages." },
 231   { .name= "unsubscribe",  .session= AFB_SESSION_NONE, .callback= unsubscribe,  .info= "unsubscribe a previous subscription." },
 232         {NULL}
 233 };
 234
 235 static const struct afb_binding binding_desc = {
 236         .type = AFB_BINDING_VERSION_1,
 237         .v1 = {
 238                 .info = "CAN bus service",
 239                 .prefix = "can",
 240                 .verbs = verbs
 241         }
 242 };
 243
 244 const struct afb_binding *afbBindingV1Register (const struct afb_binding_interface *itf)
 245 {
 246         interface = itf;
 247
 248         return &binding_desc;
 249 }
 250
 251 /**
 252  * @brief Initialize the binding.
 253  *
 254  * @param[in] service Structure which represent the Application Framework Binder.
 255  *
 256  * @return Exit code, zero if success.
 257  */
 258 int afbBindingV1ServiceInit(struct afb_service service)
 259 {
 260         std::ifstream fd_conf;
 261         std::string fd_conf_content;
 262         json_object jo_canbus;
 263
 264         /* Open JSON conf file */
 265         jo_canbus = json_object_new_object();
 266         fd_conf = afb_daemon_rootdir_open_locale(interface->daemon, "canbus.json", O_RDONLY, NULL);
 267         if (fd_conf)
 268         {
 269                 fd_conf.seekg(0, std::ios::end);
 270                 fd_conf_content.resize(fd_conf.tellg());
 271                 fd_conf.seekg(0, std::ios::beg);
 272                 fd_conf.read(&fd_conf_content[0], fd_conf_content.size());
 273                 fd_conf.close();
 274         }
 275
 276         jo_canbus = json_tokener_parse(&fd_conf_content);
 277
 278         /* Open CAN socket */
 279         can_bus_t CanBus_handler(interface, json_object_get_string(json_object_object_get(jo_canbus, "deviceName"));
 280         CanBus_handler.open();
 281         CanBus_handler.start_threads();
 282 }