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-rw-r--r--iotbzh-CAN-binding.c514
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diff --git a/iotbzh-CAN-binding.c b/iotbzh-CAN-binding.c
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+/*
+ * Copyright (C) 2015, 2016 "IoT.bzh"
+ * Author "Romain Forlot" <romain.forlot@iot.bzh>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#define _GNU_SOURCE
+
+#include <string.h>
+#include <stdbool.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/ioctl.h>
+#include <net/if.h>
+#include <sys/time.h>
+#include <linux/can.h>
+#include <math.h>
+#include <fcntl.h>
+#include <systemd/sd-event.h>
+
+#include <json-c/json.h>
+
+#include <afb/afb-binding.h>
+#include <afb/afb-service-itf.h>
+
+/*****************************************************************************************/
+/*****************************************************************************************/
+/** **/
+/** **/
+/** SECTION: GLOBAL VARIABLES **/
+/** **/
+/** **/
+/*****************************************************************************************/
+/*****************************************************************************************/
+
+/*
+ * Interface between the daemon and the binding
+ */
+static const struct afb_binding_interface *interface;
+
+/*
+ * the type of position expected
+ *
+ * here, this type is the selection of protocol
+ */
+enum type {
+ type_OBDII,
+ type_CAN,
+ type_DEFAULT = type_CAN,
+ type_INVALID = -1
+};
+
+#define type_size sizeof(enum type)-2
+
+/*
+ * names of the types
+ */
+static const char * const type_NAMES[type_size] = {
+ "OBDII",
+ "CAN"
+};
+
+struct can_handler {
+ int socket;
+ char *device;
+ char *send_msg;
+ char *read_msg;
+ struct sockaddr_can txAddress;
+};
+
+static struct can_handler can_handler = {
+ .socket = -1,
+ .device = "vcan0"
+};
+
+struct can_frame can_frame;
+
+/*****************************************************************************************/
+/*****************************************************************************************/
+/** **/
+/** **/
+/** SECTION: UTILITY FUNCTIONS **/
+/** **/
+/** **/
+/*****************************************************************************************/
+/*****************************************************************************************/
+
+/*
+ * @brief Retry a function 3 times
+ *
+ * @param int function(): function that return an int wihtout any parameter
+ *
+ * @ return : 0 if ok, -1 if failed
+ *
+ */
+static int retry( int(*func)());
+static int retry( int(*func)())
+{
+ int i;
+
+ for (i=0;i<4;i++)
+ {
+ if ( (*func)() >= 0)
+ {
+ return 0;
+ }
+ usleep(100000);
+ }
+ return -1;
+}
+
+/*****************************************************************************************/
+/*****************************************************************************************/
+/** **/
+/** **/
+/** SECTION: HANDLE CAN DEVICE **/
+/** **/
+/** **/
+/*****************************************************************************************/
+/*****************************************************************************************/
+
+static int connect_to_event_loop();
+
+/*
+ * Parse the CAN frame data payload as a CANopen packet
+ * TODO: define can_frame_t
+ */
+int can_frame_parse(canopen_frame_t *canopen_frame, struct can_frame *can_frame)
+{
+ int i;
+
+ if (canopen_frame == NULL || can_frame == NULL)
+ {
+ return -1;
+ }
+
+ bzero((void *)canopen_frame, sizeof(canopen_frame_t));
+
+ //
+ // Parse basic protocol fields
+ //
+
+ if (can_frame->can_id & CAN_EFF_FLAG)
+ {
+ canopen_frame->type = CANOPEN_FLAG_EXTENDED;
+ canopen_frame->id = can_frame->can_id & CAN_EFF_MASK;
+ }
+ else
+ {
+ canopen_frame->type = CANOPEN_FLAG_STANDARD;
+ canopen_frame->function_code = (can_frame->can_id & 0x00000780U) >> 7;
+ canopen_frame->id = (can_frame->can_id & 0x0000007FU);
+ }
+
+ canopen_frame->rtr = (can_frame->can_id & CAN_RTR_FLAG) ?
+ CANOPEN_FLAG_RTR : CANOPEN_FLAG_NORMAL;
+
+ canopen_frame->data_len = can_frame->can_dlc;
+ for (i = 0; i < can_frame->can_dlc; i++)
+ {
+ canopen_frame->payload.data[i] = can_frame->data[i];
+ }
+
+ //
+ // Parse payload data
+ //
+
+ // NMT protocol
+ switch (canopen_frame->function_code)
+ {
+ // ---------------------------------------------------------------------
+ // Network ManagemenT frame: Module Control
+ //
+ case CANOPEN_FC_NMT_MC:
+
+ break;
+
+ // ---------------------------------------------------------------------
+ // Network ManagemenT frame: Node Guarding
+ //
+ case CANOPEN_FC_NMT_NG:
+
+
+ break;
+
+ //default:
+ // unhandled type...
+ }
+
+ return 0;
+}
+
+/*
+ * Read on CAN bus
+ */
+static int read_can()
+{
+ int byte_read;
+
+ byte_read = read(can_handler.socket, &can_frame, sizeof(struct can_frame));
+
+ if (byte_read < 0)
+ {
+ ERROR(interface, "Error reading CAN bus");
+ return -1;
+ }
+
+ if (byte_read < (int)sizeof(struct can_frame))
+ {
+ ERROR(interface, "CAN frame incomplete");
+ return -2;
+ }
+}
+
+/*
+ * called on an event on the CAN bus
+ */
+static int on_event(sd_event_source *s, int fd, uint32_t revents, void *userdata)
+{
+ /* read available data */
+ if ((revents & EPOLLIN) != 0)
+ {
+ read_can();
+// event_send();
+ }
+
+ /* check if error or hangup */
+ if ((revents & (EPOLLERR|EPOLLRDHUP|EPOLLHUP)) != 0)
+ {
+ sd_event_source_unref(s);
+ close(fd);
+ connect_to_event_loop();
+ }
+
+ return 0;
+}
+
+/*
+ * open the can socket
+ */
+static int open_can_dev()
+{
+ struct ifreq ifr;
+ struct timeval timeout = {1,0};
+
+ DEBUG(interface, "open_can_dev: CAN Handler socket : %d", can_handler.socket);
+ close(can_handler.socket);
+
+ can_handler.socket = socket(PF_CAN, SOCK_RAW, CAN_RAW);
+ if (can_handler.socket < 0)
+ {
+ ERROR(interface, "open_can_dev: socket could not be created");
+ }
+ else
+ {
+ // Set timeout for read
+ setsockopt(can_handler.socket, SOL_SOCKET, SO_RCVTIMEO, (char *)&timeout, sizeof(timeout));
+ // Attempts to open a socket to CAN bus
+ strcpy(ifr.ifr_name, can_handler.device);
+ if(ioctl(can_handler.socket, SIOCGIFINDEX, &ifr) < 0)
+ {
+ ERROR(interface, "open_can_dev: ioctl failed");
+ }
+ else
+ {
+ can_handler.txAddress.can_family = AF_CAN;
+ can_handler.txAddress.can_ifindex = ifr.ifr_ifindex;
+
+ // And bind it to txAddress
+ if (bind(can_handler.socket, (struct sockaddr *)&can_handler.txAddress, sizeof(can_handler.txAddress)) < 0)
+ {
+ ERROR(interface, "open_can_dev: bind failed");
+ }
+ else
+ {
+ fcntl(can_handler.socket, F_SETFL, O_NONBLOCK);
+ return 0;
+ }
+ }
+ close(can_handler.socket);
+ can_handler.socket = -1;
+ }
+ return -1;
+}
+
+static int write_can()
+{
+ int rc = 0;
+
+ rc = can_handler.socket;
+ if (rc >= 0)
+ {
+/*
+ * TODO change old hvac write can frame to generic on_event
+ */
+ can_frame.can_id = 0x30;
+ can_frame.can_dlc = 8;
+ can_frame.data[0] = 0;
+ can_frame.data[1] = 0;
+ can_frame.data[2] = 0;
+ can_frame.data[3] = 0xf0;
+ can_frame.data[4] = 0;
+ can_frame.data[5] = 1;
+ can_frame.data[6] = 0;
+ can_frame.data[7] = 0;
+
+ DEBUG(interface, "%s: %d %d [%02x %02x %02x %02x %02x %02x %02x %02x]\n",
+ can_handler.send_msg,
+ can_frame.can_id, can_frame.can_dlc,
+ can_frame.data[0], can_frame.data[1], can_frame.data[2], can_frame.data[3],
+ can_frame.data[4], can_frame.data[5], can_frame.data[6], can_frame.data[7]);
+
+ rc = sendto(can_handler.socket, &can_frame, sizeof(struct can_frame), 0,
+ (struct sockaddr*)&can_handler.txAddress, sizeof(can_handler.txAddress));
+ if (rc < 0)
+ {
+ ERROR(interface, "Sending CAN frame failed.");
+ }
+ }
+ else
+ {
+ ERROR(interface, "socket not initialized. Attempt to reopen can device socket.");
+ retry(open_can_dev);
+ }
+ return rc;
+}
+
+/***************************************************************************************/
+/***************************************************************************************/
+/** **/
+/** **/
+/** SECTION: MANAGING EVENTS **/
+/** **/
+/** **/
+/***************************************************************************************/
+/***************************************************************************************/
+
+/*
+ * get or create an event handler for the type
+ * TODO: implement function and handle retrieve or create an event as needed
+ */
+static struct event *event_get(enum type type)
+{
+
+}
+
+static struct event *event_of_id(int id)
+{
+
+}
+
+/*****************************************************************************************/
+/*****************************************************************************************/
+/** **/
+/** **/
+/** SECTION: BINDING VERBS IMPLEMENTATION **/
+/** **/
+/** **/
+/*****************************************************************************************/
+/*****************************************************************************************/
+/*
+ * Returns the type corresponding to the given name
+ */
+static enum type type_of_name(const char *name)
+{
+ enum type result;
+ if (name == NULL)
+ return type_DEFAULT;
+ for (result = 0 ; result < type_size; result++)
+ if (strcmp(type_NAMES[result], name) == 0)
+ return result;
+ return type_INVALID;
+}
+
+/*
+ * extract a valid type from the request
+ */
+static int get_type_for_req(struct afb_req req, enum type *type)
+{
+ if ((*type = type_of_name(afb_req_value(req, "type"))) != type_INVALID)
+ return 1;
+ afb_req_fail(req, "unknown-type", NULL);
+ return 0;
+}
+
+/*
+ * subscribe to notification of new CAN messages
+ *
+ * parameters of the subscription are:
+ *
+ * TODO type: string: choose between CAN and OBDII messages formats.
+ *
+ * returns an object with 2 fields:
+ *
+ * name: string: the name of the event without its prefix
+ * id: integer: a numeric identifier of the event to be used for unsubscribing
+ */
+static void subscribe(struct afb_req req)
+{
+ enum type type;
+ const char *period;
+ struct event *event;
+ struct json_object *json;
+
+ if (get_type_for_req(req, &type))
+ {
+ event = event_get(type);
+ if (event == NULL)
+ afb_req_fail(req, "out-of-memory", NULL);
+ else if (afb_req_subscribe(req, event->event) != 0)
+ afb_req_fail_f(req, "failed", "afb_req_subscribe returned an error: %m");
+ else
+ {
+ json = json_object_new_object();
+ json_object_object_add(json, "name", json_object_new_string(event->name));
+ json_object_object_add(json, "id", json_object_new_int(event->id));
+ afb_req_success(req, json, NULL);
+ }
+ }
+}
+
+/*
+ * unsubscribe a previous subscription
+ *
+ * parameters of the unsubscription are:
+ *
+ * id: integer: the numeric identifier of the event as returned when subscribing
+ */
+static void unsubscribe(struct afb_req req)
+{
+ const char *id;
+ struct event *event;
+
+ id = afb_req_value(req, "id");
+ if (id == NULL)
+ afb_req_fail(req, "missing-id", NULL);
+ else
+ {
+ event = event_of_id(atoi(id));
+ if (event == NULL)
+ afb_req_fail(req, "bad-id", NULL);
+ else
+ {
+ afb_req_unsubscribe(req, event->event);
+ afb_req_success(req, NULL, NULL);
+ }
+ }
+}
+
+static int connect_to_event_loop()
+{
+ sd_event_source *source;
+ int rc;
+
+ retry(open_can_dev);
+
+ if (can_handler.socket < 0)
+ {
+ return can_handler.socket;
+ }
+
+ rc = sd_event_add_io(afb_daemon_get_event_loop(interface->daemon), &source, can_handler.socket, EPOLLIN, on_event, NULL);
+ if (rc < 0)
+ {
+ close(can_handler.socket);
+ ERROR(interface, "Can't connect CAN bus %s to the event loop", can_handler.device);
+ } else
+ {
+ NOTICE(interface, "Connected CAN bus %s to the event loop", can_handler.device);
+ }
+
+ return rc;
+}
+
+
+// TODO: Have to change session management flag to AFB_SESSION_CHECK to use token auth
+static const struct afb_verb_desc_v1 verbs[]=
+{
+ { .name= "subscribe", .session= AFB_SESSION_NONE, .callback= subscribe, .info= "subscribe to notification of CAN bus messages." },
+ { .name= "unsubscribe", .session= AFB_SESSION_NONE, .callback= unsubscribe, .info= "unsubscribe a previous subscription." },
+ {NULL}
+};
+
+static const struct afb_binding binding_desc = {
+ .type = AFB_BINDING_VERSION_1,
+ .v1 = {
+ .info = "CAN bus service",
+ .prefix = "can",
+ .verbs = verbs
+ }
+};
+
+const struct afb_binding *afbBindingV1Register (const struct afb_binding_interface *itf)
+{
+ interface = itf;
+
+ return &binding_desc;
+}
+
+int afbBindingV1ServiceInit(struct afb_service service)
+{
+ return connect_to_event_loop();
+}