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