can-utils/j1939_timedate/j1939_timedate_srv.c

451 lines
11 KiB
C

// SPDX-License-Identifier: LGPL-2.0-only
// SPDX-FileCopyrightText: 2024 Oleksij Rempel <linux@rempel-privat.de>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <getopt.h>
#include <linux/kernel.h>
#include <net/if.h>
#include <poll.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include "j1939_timedate_cmn.h"
#define J1939_TIMEDATE_SRV_MAX_EPOLL_EVENTS 10
struct j1939_timedate_srv_priv {
int sock_nack;
int sock_main;
struct sockaddr_can sockname;
struct j1939_timedate_stats stats;
struct libj1939_cmn cmn;
};
static void gmtime_to_j1939_pgn_65254_td(struct j1939_time_date_packet *tdp)
{
struct tm utc_tm_buf, local_tm_buf;
int hour_offset, minute_offset;
struct tm *utc_tm, *local_tm;
int year_since_1985;
time_t now;
now = time(NULL);
utc_tm = gmtime_r(&now, &utc_tm_buf);
local_tm = localtime_r(&now, &local_tm_buf);
/* Calculate the offsets */
hour_offset = local_tm->tm_hour - utc_tm->tm_hour;
minute_offset = local_tm->tm_min - utc_tm->tm_min;
/* Handle date rollover */
if (local_tm->tm_mday != utc_tm->tm_mday) {
if (local_tm->tm_hour < 12)
hour_offset += 24; /* past midnight */
else
hour_offset -= 24; /* before midnight */
}
/*
* Seconds (spn959):
* Resolution: 0.25 /bit, 0 offset
* Data Range: 0 to 250 (0 to 62.5 seconds)
* Operational Range: 0 to 239 (0 to 59.75 seconds)
*/
tdp->seconds = (uint8_t)(utc_tm->tm_sec / 0.25);
if (tdp->seconds > 239)
tdp->seconds = 239;
/*
* Minutes (spn960):
* Resolution: 1 min/bit, 0 offset
* Data Range: 0 to 250 (0 to 250 minutes)
* Operational Range: 0 to 59 (0 to 59 minutes)
*/
tdp->minutes = (uint8_t)utc_tm->tm_min;
if (tdp->minutes > 59)
tdp->minutes = 59;
/*
* Hours (spn961):
* Resolution: 1 hr/bit, 0 offset
* Data Range: 0 to 250 (0 to 250 hours)
* Operational Range: 0 to 23 (0 to 23 hours)
*/
tdp->hours = (uint8_t)utc_tm->tm_hour;
if (tdp->hours > 23)
tdp->hours = 23;
/*
* Day (spn962):
* Resolution: 0.25 /bit, 0 offset
* Data Range: 0 to 250 (0 to 62.5 days)
* Operational Range: 1 to 127 (0.25 to 31.75 days)
*/
tdp->day = (uint8_t)(utc_tm->tm_mday / 0.25);
if (tdp->day < 1 || tdp->day > 127)
tdp->day = 1;
/*
* Month (spn963):
* Resolution: 1 month/bit, 0 offset
* Data Range: 0 to 250 (0 to 250 months)
* Operational Range: 1 to 12 (1 to 12 months)
*/
tdp->month = (uint8_t)(utc_tm->tm_mon + 1);
if (tdp->month < 1 || tdp->month > 12)
tdp->month = 1;
/*
* Year (spn964):
* Resolution: 1 year/bit, 1985 offset
* Data Range: 0 to 250 (1985 to 2235)
* Operational Range: 0 to 250 (1985 to 2235)
*/
year_since_1985 = utc_tm->tm_year - 85;
if (year_since_1985 < 0) {
/* Fallback to year 1985 if year is before 1985 */
tdp->year = 0;
} else if (year_since_1985 > 250) {
/* Fallback to year 2235 if year is beyond 2235 */
tdp->year = 250;
} else {
tdp->year = (uint8_t)year_since_1985;
}
/*
* Local minute offset (spn1601):
* Resolution: 1 min/bit, -125 offset
* Data Range: -125 to 125 minutes
* Operational Range: -59 to 59 minutes
*/
tdp->local_minute_offset = (int8_t)minute_offset;
/*
* Local hour offset (spn1602):
* Resolution: 1 hr/bit, -125 offset
* Data Range: -125 to +125 hours
* Operational Range: -24 to +23 hours
* Note: If the local hour offset parameter is equal to 125 (0xFA),
* the local time then the time parameter is the local time instead of
* UTC.
*/
tdp->local_hour_offset = (int8_t)hour_offset;
}
static int j1939_timedate_srv_send_res(struct j1939_timedate_srv_priv *priv,
struct sockaddr_can *addr)
{
struct sockaddr_can peername = *addr;
struct j1939_time_date_packet tdp;
int ret;
gmtime_to_j1939_pgn_65254_td(&tdp);
peername.can_addr.j1939.pgn = J1939_PGN_TD;
ret = sendto(priv->sock_main, &tdp, sizeof(tdp), 0,
(struct sockaddr *)&peername, sizeof(peername));
if (ret == -1) {
ret = -errno;
pr_warn("failed to send data: %i (%s)", ret, strerror(ret));
return ret;
}
return 0;
}
// check if the received message is a request for the time and date
static int j1939_timedate_srv_process_request(struct j1939_timedate_srv_priv *priv,
struct j1939_timedate_msg *msg)
{
if (msg->buf[0] != (J1939_PGN_TD & 0xff) ||
msg->buf[1] != ((J1939_PGN_TD >> 8) & 0xff) ||
msg->buf[2] != ((J1939_PGN_TD >> 16) & 0xff)) {
/* Don't care, not a time and date request */
return 0;
}
return j1939_timedate_srv_send_res(priv, &msg->peername);
}
static int j1939_timedate_srv_rx_buf(struct j1939_timedate_srv_priv *priv, struct j1939_timedate_msg *msg)
{
pgn_t pgn = msg->peername.can_addr.j1939.pgn;
int ret = 0;
switch (pgn) {
case J1939_PGN_REQUEST_PGN:
ret = j1939_timedate_srv_process_request(priv, msg);
break;
default:
pr_warn("%s: unsupported PGN: %x", __func__, pgn);
/* Not a critical error */
break;
}
return ret;
}
static int j1939_timedate_srv_rx_one(struct j1939_timedate_srv_priv *priv, int sock)
{
struct j1939_timedate_msg *msg;
int flags = 0;
int ret;
msg = malloc(sizeof(*msg));
if (!msg) {
pr_err("can't allocate rx msg struct\n");
return -ENOMEM;
}
msg->buf_size = J1939_TIMEDATE_MAX_TRANSFER_LENGH;
msg->peer_addr_len = sizeof(msg->peername);
msg->sock = sock;
ret = recvfrom(sock, &msg->buf[0], msg->buf_size, flags,
(struct sockaddr *)&msg->peername, &msg->peer_addr_len);
if (ret < 0) {
ret = -errno;
pr_warn("recvfrom() failed: %i %s", ret, strerror(-ret));
return ret;
}
if (ret < 3) {
pr_warn("received too short message: %i", ret);
return -EINVAL;
}
msg->len = ret;
ret = j1939_timedate_srv_rx_buf(priv, msg);
if (ret < 0) {
pr_warn("failed to process rx buf: %i (%s)\n", ret,
strerror(ret));
return ret;
}
return 0;
}
static int j1939_timedate_srv_handle_events(struct j1939_timedate_srv_priv *priv,
unsigned int nfds)
{
int ret;
unsigned int n;
for (n = 0; n < nfds && n < priv->cmn.epoll_events_size; ++n) {
struct epoll_event *ev = &priv->cmn.epoll_events[n];
if (!ev->events) {
warn("no events");
continue;
}
if (ev->events & POLLIN) {
ret = j1939_timedate_srv_rx_one(priv, ev->data.fd);
if (ret) {
warn("recv one");
return ret;
}
}
}
return 0;
}
static int j1939_timedate_srv_process_events_and_tasks(struct j1939_timedate_srv_priv *priv)
{
int ret, nfds;
ret = libj1939_prepare_for_events(&priv->cmn, &nfds, false);
if (ret)
return ret;
if (nfds > 0) {
ret = j1939_timedate_srv_handle_events(priv, nfds);
if (ret)
return ret;
}
return 0;
}
static int j1939_timedate_srv_sock_main_prepare(struct j1939_timedate_srv_priv *priv)
{
struct sockaddr_can addr = priv->sockname;
int ret;
ret = libj1939_open_socket();
if (ret < 0)
return ret;
priv->sock_main = ret;
ret = libj1939_bind_socket(priv->sock_main, &addr);
if (ret < 0)
return ret;
ret = libj1939_socket_prio(priv->sock_main,
J1939_TIMEDATE_PRIO_DEFAULT);
if (ret < 0)
return ret;
ret = libj1939_set_broadcast(priv->sock_main);
if (ret < 0)
return ret;
return libj1939_add_socket_to_epoll(priv->cmn.epoll_fd,
priv->sock_main, EPOLLIN);
}
static int j1939_timedate_srv_sock_prepare(struct j1939_timedate_srv_priv *priv)
{
int ret;
ret = libj1939_create_epoll();
if (ret < 0)
return ret;
priv->cmn.epoll_fd = ret;
priv->cmn.epoll_events = calloc(J1939_TIMEDATE_SRV_MAX_EPOLL_EVENTS,
sizeof(struct epoll_event));
if (!priv->cmn.epoll_events)
return -ENOMEM;
priv->cmn.epoll_events_size = J1939_TIMEDATE_SRV_MAX_EPOLL_EVENTS;
return j1939_timedate_srv_sock_main_prepare(priv);
}
static void j1939_timedate_srv_print_help(void)
{
printf("Usage: j1939-timedate-srv [options]\n");
printf("Options:\n");
printf(" --interface <interface_name> or -i <interface_name>\n");
printf(" Specifies the CAN interface to use (mandatory).\n");
printf(" --local-address <local_address_hex> or -a <local_address_hex>\n");
printf(" Specifies the local address in hexadecimal (mandatory if\n");
printf(" local name is not provided).\n");
printf(" --local-name <local_name_hex> or -n <local_name_hex>\n");
printf(" Specifies the local NAME in hexadecimal (mandatory if\n");
printf(" local address is not provided).\n");
printf("\n");
printf("Note: Local address and local name are mutually exclusive and one\n");
printf(" must be provided.\n");
printf("\n");
printf("Usage Examples:\n");
printf(" Using local address:\n");
printf(" j1939-timedate-srv -i vcan0 -a 0x90\n");
printf("\n");
printf(" Using local NAME:\n");
printf(" j1939acd -r 64-95 -c /tmp/1122334455667789.jacd 1122334455667789 vcan0 &\n");
printf(" j1939-timedate-srv -i vcan0 -n 0x1122334455667789\n");
}
static int j1939_timedate_srv_parse_args(struct j1939_timedate_srv_priv *priv,
int argc, char *argv[])
{
struct sockaddr_can *local = &priv->sockname;
bool local_address_set = false;
bool local_name_set = false;
bool interface_set = false;
int long_index = 0;
int opt;
static struct option long_options[] = {
{"interface", required_argument, 0, 'i'},
{"local-address", required_argument, 0, 'a'},
{"local-name", required_argument, 0, 'n'},
{0, 0, 0, 0}
};
while ((opt = getopt_long(argc, argv, "a:n:i:", long_options, &long_index)) != -1) {
switch (opt) {
case 'a':
local->can_addr.j1939.addr = strtoul(optarg, NULL, 16);
local_address_set = true;
break;
case 'n':
local->can_addr.j1939.name = strtoull(optarg, NULL, 16);
local_name_set = true;
break;
case 'i':
local->can_ifindex = if_nametoindex(optarg);
if (!local->can_ifindex) {
pr_err("Interface %s not found. Error: %d (%s)\n",
optarg, errno, strerror(errno));
return -EINVAL;
}
interface_set = true;
break;
default:
j1939_timedate_srv_print_help();
return -EINVAL;
}
}
if (!interface_set) {
pr_err("interface not specified");
j1939_timedate_srv_print_help();
return -EINVAL;
}
if (local_address_set && local_name_set) {
pr_err("local address and local name or remote address and remote name are mutually exclusive");
j1939_timedate_srv_print_help();
return -EINVAL;
}
return 0;
}
int main(int argc, char *argv[])
{
struct j1939_timedate_srv_priv *priv;
struct timespec ts;
int ret;
priv = malloc(sizeof(*priv));
if (!priv)
err(EXIT_FAILURE, "can't allocate priv");
bzero(priv, sizeof(*priv));
libj1939_init_sockaddr_can(&priv->sockname, J1939_PGN_REQUEST_PGN);
ret = j1939_timedate_srv_parse_args(priv, argc, argv);
if (ret)
return ret;
clock_gettime(CLOCK_MONOTONIC, &ts);
priv->cmn.next_send_time = ts;
ret = j1939_timedate_srv_sock_prepare(priv);
if (ret)
return ret;
while (1) {
ret = j1939_timedate_srv_process_events_and_tasks(priv);
if (ret)
break;
}
close(priv->cmn.epoll_fd);
free(priv->cmn.epoll_events);
close(priv->sock_main);
close(priv->sock_nack);
return ret;
}