diff options
Diffstat (limited to 'canLL-binding.c')
| -rw-r--r-- | canLL-binding.c | 569 |
1 files changed, 569 insertions, 0 deletions
diff --git a/canLL-binding.c b/canLL-binding.c new file mode 100644 index 0000000..342eb4f --- /dev/null +++ b/canLL-binding.c @@ -0,0 +1,569 @@ +/* + * 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> + +/*****************************************************************************************/ +/*****************************************************************************************/ +/** **/ +/** **/ +/** SECTION: GLOBAL VARIABLES **/ +/** **/ +/** **/ +/*****************************************************************************************/ +/*****************************************************************************************/ +/* max. number of CAN interfaces given on the cmdline */ +#define MAXSOCK 16 + +/* buffer sizes for CAN frame string representations */ +#define CL_ID (sizeof("12345678##1")) +#define CL_DATA sizeof(".AA") +#define CL_BINDATA sizeof(".10101010") + + /* CAN FD ASCII hex short representation with DATA_SEPERATORs */ +#define CL_CFSZ (2*CL_ID + 64*CL_DATA) + +#define CANID_DELIM '#' + +/* + * 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 + +/* CAN variable initialization */ +struct canfd_frame canfd_frame; + +struct can_handler { + int socket; + char *device; + openxc_CanMessage *msg; + struct sockaddr_can txAddress; +}; + +/* + * each generated event + */ +struct event { + struct event *next; /* link for the same period */ + const char *name; /* name of the event */ + struct afb_event event; /* the event for the binder */ + enum type type; /* the type of data expected */ + int id; /* id of the event for unsubscribe */ +}; + +/*****************************************************************************************/ +/*****************************************************************************************/ +/** **/ +/** **/ +/** 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 **/ +/** **/ +/** **/ +/*****************************************************************************************/ +/*****************************************************************************************/ +const char hex_asc_upper[] = "0123456789ABCDEF"; + +#define hex_asc_upper_lo(x) hex_asc_upper[((x) & 0x0F)] +#define hex_asc_upper_hi(x) hex_asc_upper[((x) & 0xF0) >> 4] + +static inline void put_hex_byte(char *buf, __u8 byte) +{ + buf[0] = hex_asc_upper_hi(byte); + buf[1] = hex_asc_upper_lo(byte); +} + +static inline void _put_id(char *buf, int end_offset, canid_t id) +{ + /* build 3 (SFF) or 8 (EFF) digit CAN identifier */ + while (end_offset >= 0) { + buf[end_offset--] = hex_asc_upper[id & 0xF]; + id >>= 4; + } +} + +#define put_sff_id(buf, id) _put_id(buf, 2, id) +#define put_eff_id(buf, id) _put_id(buf, 7, id) + +static void canread_frame_parse(struct canfd_frame *canfd_frame, int maxdlen); + +/* + * names of the types + */ +static const char * const type_NAMES[type_size] = { + "OBDII", + "CAN" +}; + + +// Initialize default can_handler values +static struct can_handler can_handler = { + .socket = -1, + .device = "vcan0", +}; + + +/* + * open the can socket + */ +static int open_can_dev() +{ + const int canfd_on = 1; + struct ifreq ifr; + struct timeval timeout = {1,0}; + openxc_CanMessage can_msg = { + .has_bus = false, + .has_id = false, + .has_data = false, + .has_frame_format = false, + }; + + 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)); + /* try to switch the socket into CAN_FD mode */ + can_msg.has_frame_format = true; + 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_msg.frame_format = openxc_CanMessage_FrameFormat_STANDARD; + } else { + can_msg.frame_format = openxc_CanMessage_FrameFormat_EXTENDED; + } + + /* 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); + can_handler.msg = &can_msg; + return 0; + } + } + close(can_handler.socket); + can_handler.socket = -1; + } + return -1; +} + +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. + */ +static int read_can() +{ + 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; + } + + canread_frame_parse(&canfd_frame, maxdlen); +} + +/* + * Parse the CAN frame data payload as a CAN packet + * TODO: parse as an OpenXC Can Message + */ +static void canread_frame_parse(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) { + 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; + } + + 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; +} + +/***************************************************************************************/ +/***************************************************************************************/ +/** **/ +/** **/ +/** SECTION: MANAGING EVENTS **/ +/** **/ +/** **/ +/***************************************************************************************/ +/***************************************************************************************/ +static int connect_to_event_loop(); + +/* + * 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); +// 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; +} + +/* + * 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 = afb_daemon_make_event(interface->daemon, type_NAMES[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(); +} |