diff options
Diffstat (limited to 'll-can-binding.c')
| -rw-r--r-- | ll-can-binding.c | 560 |
1 files changed, 560 insertions, 0 deletions
diff --git a/ll-can-binding.c b/ll-can-binding.c new file mode 100644 index 00000000..bc52d17f --- /dev/null +++ b/ll-can-binding.c @@ -0,0 +1,560 @@ +/* + * 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 <linux/can/raw.h> +#include <math.h> +#include <fcntl.h> +#include <systemd/sd-event.h> +#include <errno.h> + +#include <json-c/json.h> +#include <openxc.pb.h> + +#include <afb/afb-binding.h> +#include <afb/afb-service-itf.h> + +#include "canLL-binding.h" + +/*************************************************************************/ +/*************************************************************************/ +/** **/ +/** **/ +/** SECTION: UTILITY FUNCTIONS **/ +/** **/ +/** **/ +/*************************************************************************/ +/*************************************************************************/ + +/* + * 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; +} + +/* + * Browse chained list and return the one with specified id + * + * param uint32_t id : can arbitration identifier + * + * return can_event + */ +static can_event *get_event_of_id(uint32_t id) +{ + can_event *current; + + /* create and return if lists not exists */ + if (!can_events_list) + { + can_events_list = (can_event*)calloc(1, sizeof(can_event)); + can_events_list->id = id; + return can_events_list; + } + + /* search for id */ + current = can_events_list; + while(current) + { + if (current->id == id) + return current; + if (!current->next) + { + current->next = (can_event*)calloc(1, sizeof(can_event)); + current->next->id = id; + return current->next; + } + current = current->next; + } + + return NULL; +} + +/* + * Take an id and return it into a char array + */ +char* create_name(uint32_t id) +{ + char name[32]; + size_t nchar; + + nchar = (size_t)sprintf(name, "can_%u", id); + if (nchar > 0) + { + char *result = (char*)malloc(nchar + 1); + memcpy(result, name, nchar); + result[nchar] = 0; + return result; + } + + return NULL; +} + +/*************************************************************************/ +/*************************************************************************/ +/** **/ +/** **/ +/** SECTION: HANDLE CAN DEVICE **/ +/** **/ +/** **/ +/*************************************************************************/ +/*************************************************************************/ +/* + * open the can socket + */ +static int open_can_dev() +{ + const int canfd_on = 1; + struct ifreq ifr; + struct timeval timeout = {1,0}; + + DEBUG(interface, "open_can_dev: CAN Handler socket : %d", can_handler.socket); + if (can_handler.socket >= 0) + 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)); + /* try to switch the socket into CAN_FD mode */ + if (setsockopt(can_handler.socket, SOL_CAN_RAW, CAN_RAW_FD_FRAMES, &canfd_on, sizeof(canfd_on)) < 0) + { + NOTICE(interface, "open_can_dev: Can not switch into CAN Extended frame format."); + can_handler.is_fdmode_on = false; + } else { + can_handler.is_fdmode_on = true; + } + + /* 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; +} + +/* + * TODO : test that socket is really opened + */ +static int write_can() +{ + ssize_t nbytes; + int rc; + + rc = can_handler.socket; + if (rc >= 0) + { +/* + * TODO change old hvac write can frame to generic on_event + */ + nbytes = sendto(can_handler.socket, &canfd_frame, sizeof(struct canfd_frame), 0, + (struct sockaddr*)&can_handler.txAddress, sizeof(can_handler.txAddress)); + if (nbytes < 0) + { + ERROR(interface, "write_can: Sending CAN frame failed."); + } + } + else + { + ERROR(interface, "write_can: socket not initialized. Attempt to reopen can device socket."); + retry(open_can_dev); + } + return rc; +} + +/* + * Read on CAN bus and return how much bytes has been read. + * TODO : test that socket is really opened + */ +static int read_can(openxc_CanMessage *can_message) +{ + ssize_t nbytes; + int maxdlen; + + nbytes = read(can_handler.socket, &canfd_frame, CANFD_MTU); + + if (nbytes == CANFD_MTU) + { + DEBUG(interface, "read_can: Got an CAN FD frame with length %d", canfd_frame.len); + } + else if (nbytes == CAN_MTU) + { + DEBUG(interface, "read_can: Got a legacy CAN frame with length %d", canfd_frame.len); + } + else + { + if (errno == ENETDOWN) + ERROR(interface, "read_can: %s interface down", can_handler.device); + ERROR(interface, "read_can: Error reading CAN bus"); + return -1; + } + + /* CAN frame integrity check */ + if ((size_t)nbytes == CAN_MTU) + maxdlen = CAN_MAX_DLEN; + else if ((size_t)nbytes == CANFD_MTU) + maxdlen = CANFD_MAX_DLEN; + else + { + ERROR(interface, "read_can: CAN frame incomplete"); + return -2; + } + + parse_can_frame(can_message, &canfd_frame, maxdlen); +} + +/* + * Parse the CAN frame data payload as a CAN packet + * TODO: parse as an OpenXC Can Message. Don't translate as ASCII and put bytes + * directly into openxc_CanMessage + */ +static void parse_can_frame(openxc_CanMessage *can_message, struct canfd_frame *canfd_frame, int maxdlen) +{ + int i,offset; + int len = (canfd_frame->len > maxdlen) ? maxdlen : canfd_frame->len; + char buf[CL_CFSZ]; + + if (canfd_frame->can_id & CAN_ERR_FLAG) + { + can_message->has_id = true; + can_message->id = canfd_frame->can_id; + put_eff_id(buf, canfd_frame->can_id & (CAN_ERR_MASK|CAN_ERR_FLAG)); + buf[8] = '#'; + offset = 9; + } else if (canfd_frame->can_id & CAN_EFF_FLAG) + { + put_eff_id(buf, canfd_frame->can_id & CAN_EFF_MASK); + buf[8] = '#'; + offset = 9; + } else { + put_sff_id(buf, canfd_frame->can_id & CAN_SFF_MASK); + buf[3] = '#'; + offset = 4; + } + + /* standard CAN frames may have RTR enabled. There are no ERR frames with RTR */ + if (maxdlen == CAN_MAX_DLEN && canfd_frame->can_id & CAN_RTR_FLAG) + { + buf[offset++] = 'R'; + /* print a given CAN 2.0B DLC if it's not zero */ + if (canfd_frame->len && canfd_frame->len <= CAN_MAX_DLC) + buf[offset++] = hex_asc_upper[canfd_frame->len & 0xF]; + + buf[offset] = 0; + return; + } + + if (maxdlen == CANFD_MAX_DLEN) + { + /* add CAN FD specific escape char and flags */ + buf[offset++] = '#'; + buf[offset++] = hex_asc_upper[canfd_frame->flags & 0xF]; + } + + for (i = 0; i < len; i++) + { + put_hex_byte(buf + offset, canfd_frame->data[i]); + offset += 2; + } + + buf[offset] = 0; + return; +} + +/*************************************************************************/ +/*************************************************************************/ +/** **/ +/** **/ +/** SECTION: MANAGING EVENTS **/ +/** **/ +/** **/ +/*************************************************************************/ +/*************************************************************************/ +/* + * called on an event on the CAN bus + */ +static int on_event(sd_event_source *s, int fd, uint32_t revents, void *userdata) +{ + openxc_CanMessage can_message; + + /* read available data */ + if ((revents & EPOLLIN) != 0) + { + read_can(&can_message); + send_event(); + } + + /* check if error or hangup */ + if ((revents & (EPOLLERR|EPOLLRDHUP|EPOLLHUP)) != 0) + { + sd_event_source_unref(s); + close(fd); + connect_to_event_loop(); + } + + return 0; +} + +/* + * get or create an event handler for the type + * TODO: implement function and handle retrieve or create an event as needed + */ +static event *get_event(uint32_t id, enum type type) +{ + event *event; + can_event *list; + + /* find the can list by id */ + list = get_event_of_id(id); + + /* make the new event */ + event = (can_event*)calloc(1, sizeof(can_event)); + event->next = event; + list->events = event; + event->name = create_name(id); + event->afb_event = afb_daemon_make_event(interface->daemon, event->name); + + return event; +} + +/* + * Send an event + */ +static void send_event() +{ + can_event *current; + + /* search for id */ + current = can_events_list; + while(current) + { + afb_event_push(current->afb_event, object); + current = current->next; + } +} + +/* + * Get the event loop running. + * Will trigger on_event function on EPOLLIN event on socket + * + * Return 0 or positive value on success. Else negative value for failure. + */ +static int connect_to_event_loop() +{ + sd_event *event_loop; + sd_event_source *source; + int rc; + + if (can_handler.socket < 0) + { + return can_handler.socket; + } + + event_loop = afb_daemon_get_event_loop(interface->daemon); + rc = sd_event_add_io(event_loop, &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; +} + + +/*************************************************************************/ +/*************************************************************************/ +/** **/ +/** **/ +/** 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 ; (size_t)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; + event *event; + uint32_t id; + struct json_object *json; + + if (get_type_for_req(req, &type)) + { + id = (uint32_t)atoi(afb_req_value(req, "id")); + event = get_event(id, type); + if (event == NULL) + afb_req_fail(req, "out-of-memory", NULL); + else if (afb_req_subscribe(req, event->afb_event) != 0) + afb_req_fail_f(req, "failed", "afb_req_subscribe returned an error: %m"); + else + { + /* TODO : build json openXC message to send. I guess */ + json = json_object_new_object(); + json_object_object_add(json, "name", json_object_new_string(event->name)); + 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; + event *event; + + id = afb_req_value(req, "id"); + if (id == NULL) + afb_req_fail(req, "missing-id", NULL); + else + { + event = get_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); + } + } +} + +// 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) +{ + /* Open CAN socket */ + retry(open_can_dev); + return connect_to_event_loop(); +} |