303 lines
7.0 KiB
C
303 lines
7.0 KiB
C
/* T-Link interface using POSIX serial port */
|
|
|
|
/* (C) 2008-2011 by Harald Welte <laforge@gnumonks.org>
|
|
*
|
|
* All Rights Reserved
|
|
*
|
|
* Authors: Harald Welte <laforge@gnumonks.org>
|
|
* Pablo Neira Ayuso <pablo@gnumonks.org>
|
|
*
|
|
* SPDX-License-Identifier: AGPL-3.0+
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU Affero General Public License as published by
|
|
* the Free Software Foundation; either version 3 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU Affero General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Affero General Public License
|
|
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*
|
|
*/
|
|
|
|
#include <unistd.h>
|
|
#include <stdlib.h>
|
|
#include <stdio.h>
|
|
#include <errno.h>
|
|
#include <string.h>
|
|
#include <termios.h>
|
|
#include <fcntl.h>
|
|
|
|
#include <osmocom/core/select.h>
|
|
#include <osmocom/core/msgb.h>
|
|
#include <osmocom/core/logging.h>
|
|
#include <osmocom/core/talloc.h>
|
|
#include <osmocom/abis/e1_input.h>
|
|
|
|
static void *tall_rs232_ctx;
|
|
|
|
struct serial_handle {
|
|
struct e1inp_line *line;
|
|
|
|
struct msgb *rx_msg;
|
|
unsigned int rxmsg_bytes_missing;
|
|
|
|
unsigned int delay_ms;
|
|
};
|
|
|
|
#define CRAPD_HDR_LEN 10
|
|
|
|
static int handle_ser_write(struct osmo_fd *bfd);
|
|
|
|
static void rs232_build_msg(struct msgb *msg)
|
|
{
|
|
uint8_t *crapd;
|
|
unsigned int len;
|
|
|
|
msg->l2h = msg->data;
|
|
|
|
/* prepend CRAPD header */
|
|
crapd = msgb_push(msg, CRAPD_HDR_LEN);
|
|
|
|
len = msg->len - 2;
|
|
|
|
crapd[0] = (len >> 8) & 0xff;
|
|
crapd[1] = len & 0xff; /* length of bytes startign at crapd[2] */
|
|
crapd[2] = 0x00;
|
|
crapd[3] = 0x07;
|
|
crapd[4] = 0x01;
|
|
crapd[5] = 0x3e;
|
|
crapd[6] = 0x00;
|
|
crapd[7] = 0x00;
|
|
crapd[8] = msg->len - 10; /* length of bytes starting at crapd[10] */
|
|
crapd[9] = crapd[8] ^ 0x38;
|
|
}
|
|
|
|
/* select.c callback in case we can write to the rs232 */
|
|
static int handle_ser_write(struct osmo_fd *bfd)
|
|
{
|
|
struct serial_handle *sh = bfd->data;
|
|
struct e1inp_ts *e1i_ts = &sh->line->ts[0];
|
|
struct e1inp_sign_link *sign_link;
|
|
struct msgb *msg;
|
|
int written;
|
|
|
|
bfd->when &= ~BSC_FD_WRITE;
|
|
|
|
/* get the next msg for this timeslot */
|
|
msg = e1inp_tx_ts(e1i_ts, &sign_link);
|
|
if (!msg) {
|
|
/* no message after tx delay timer */
|
|
return 0;
|
|
}
|
|
DEBUGP(DLMI, "rs232 TX: %s\n", osmo_hexdump(msg->data, msg->len));
|
|
|
|
rs232_build_msg(msg);
|
|
|
|
/* send over serial line */
|
|
written = write(bfd->fd, msg->data, msg->len);
|
|
if (written < msg->len) {
|
|
LOGP(DLMI, LOGL_ERROR, "rs232: short write\n");
|
|
msgb_free(msg);
|
|
return -1;
|
|
}
|
|
|
|
msgb_free(msg);
|
|
usleep(sh->delay_ms*1000);
|
|
|
|
return 0;
|
|
}
|
|
|
|
#define SERIAL_ALLOC_SIZE 300
|
|
|
|
/* select.c callback in case we can read from the rs232 */
|
|
static int handle_ser_read(struct osmo_fd *bfd)
|
|
{
|
|
struct serial_handle *sh = bfd->data;
|
|
struct msgb *msg;
|
|
int rc = 0;
|
|
|
|
if (!sh->rx_msg) {
|
|
sh->rx_msg = msgb_alloc(SERIAL_ALLOC_SIZE, "rs232 Rx");
|
|
sh->rx_msg->l2h = NULL;
|
|
}
|
|
msg = sh->rx_msg;
|
|
|
|
/* first read two byes to obtain length */
|
|
if (msg->len < 2) {
|
|
rc = read(bfd->fd, msg->tail, 2 - msg->len);
|
|
if (rc < 0) {
|
|
LOGP(DLMI, LOGL_ERROR, "rs232: error reading from "
|
|
"serial port: %s\n", strerror(errno));
|
|
msgb_free(msg);
|
|
return rc;
|
|
}
|
|
msgb_put(msg, rc);
|
|
|
|
if (msg->len >= 2) {
|
|
/* parse CRAPD payload length */
|
|
if (msg->data[0] != 0) {
|
|
LOGP(DLMI, LOGL_ERROR,
|
|
"Suspicious header byte 0: 0x%02x\n",
|
|
msg->data[0]);
|
|
}
|
|
sh->rxmsg_bytes_missing = msg->data[0] << 8;
|
|
sh->rxmsg_bytes_missing += msg->data[1];
|
|
|
|
if (sh->rxmsg_bytes_missing < CRAPD_HDR_LEN -2) {
|
|
LOGP(DLMI, LOGL_ERROR,
|
|
"Invalid length in hdr: %u\n",
|
|
sh->rxmsg_bytes_missing);
|
|
}
|
|
}
|
|
} else {
|
|
/* try to read as many of the missing bytes as are available */
|
|
rc = read(bfd->fd, msg->tail, sh->rxmsg_bytes_missing);
|
|
if (rc < 0) {
|
|
LOGP(DLMI, LOGL_ERROR, "rs232: error reading from "
|
|
"serial port: %s", strerror(errno));
|
|
msgb_free(msg);
|
|
return rc;
|
|
}
|
|
msgb_put(msg, rc);
|
|
sh->rxmsg_bytes_missing -= rc;
|
|
|
|
if (sh->rxmsg_bytes_missing == 0) {
|
|
struct e1inp_ts *e1i_ts = &sh->line->ts[0];
|
|
|
|
/* we have one complete message now */
|
|
sh->rx_msg = NULL;
|
|
|
|
if (msg->len > CRAPD_HDR_LEN)
|
|
msg->l2h = msg->data + CRAPD_HDR_LEN;
|
|
|
|
DEBUGP(DLMI, "rs232 RX: %s",
|
|
osmo_hexdump(msg->data, msg->len));
|
|
|
|
/* don't use e1inp_tx_ts() here, this header does not
|
|
* contain any SAPI and TEI values. */
|
|
if (!e1i_ts->line->ops->sign_link) {
|
|
LOGP(DLMI, LOGL_ERROR, "rs232: no callback set, "
|
|
"skipping message.\n");
|
|
return -EINVAL;
|
|
}
|
|
e1i_ts->line->ops->sign_link(msg);
|
|
}
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
/* select.c callback */
|
|
static int serial_fd_cb(struct osmo_fd *bfd, unsigned int what)
|
|
{
|
|
int rc = 0;
|
|
|
|
if (what & BSC_FD_READ)
|
|
rc = handle_ser_read(bfd);
|
|
|
|
if (rc < 0)
|
|
return rc;
|
|
|
|
if (what & BSC_FD_WRITE)
|
|
rc = handle_ser_write(bfd);
|
|
|
|
return rc;
|
|
}
|
|
|
|
static int rs232_want_write(struct e1inp_ts *e1i_ts)
|
|
{
|
|
e1i_ts->driver.rs232.fd.when |= BSC_FD_WRITE;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
rs232_setup(struct e1inp_line *line, const char *serial_port, unsigned int delay_ms)
|
|
{
|
|
int rc;
|
|
struct osmo_fd *bfd = &line->ts[0].driver.rs232.fd;
|
|
struct serial_handle *ser_handle;
|
|
struct termios tio;
|
|
|
|
rc = open(serial_port, O_RDWR);
|
|
if (rc < 0) {
|
|
LOGP(DLMI, LOGL_ERROR, "rs232: cannot open serial port: %s",
|
|
strerror(errno));
|
|
return rc;
|
|
}
|
|
bfd->fd = rc;
|
|
|
|
/* set baudrate */
|
|
rc = tcgetattr(bfd->fd, &tio);
|
|
if (rc < 0) {
|
|
LOGP(DLMI, LOGL_ERROR, "rs232: tcgetattr says: %s",
|
|
strerror(errno));
|
|
return rc;
|
|
}
|
|
cfsetispeed(&tio, B19200);
|
|
cfsetospeed(&tio, B19200);
|
|
tio.c_cflag |= (CREAD | CLOCAL | CS8);
|
|
tio.c_cflag &= ~(PARENB | CSTOPB | CSIZE | CRTSCTS);
|
|
tio.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG);
|
|
tio.c_iflag |= (INPCK | ISTRIP);
|
|
tio.c_iflag &= ~(ISTRIP | IXON | IXOFF | IGNBRK | INLCR | ICRNL | IGNCR);
|
|
tio.c_oflag &= ~(OPOST);
|
|
rc = tcsetattr(bfd->fd, TCSADRAIN, &tio);
|
|
if (rc < 0) {
|
|
LOGP(DLMI, LOGL_ERROR, "rs232: tcsetattr says: %s",
|
|
strerror(errno));
|
|
return rc;
|
|
}
|
|
|
|
ser_handle = talloc_zero(tall_rs232_ctx, struct serial_handle);
|
|
if (ser_handle == NULL) {
|
|
close(bfd->fd);
|
|
LOGP(DLMI, LOGL_ERROR, "rs232: cannot allocate memory for "
|
|
"serial handler\n");
|
|
return -ENOMEM;
|
|
}
|
|
ser_handle->line = line;
|
|
ser_handle->delay_ms = delay_ms;
|
|
|
|
bfd->when = BSC_FD_READ;
|
|
bfd->cb = serial_fd_cb;
|
|
bfd->data = ser_handle;
|
|
|
|
rc = osmo_fd_register(bfd);
|
|
if (rc < 0) {
|
|
close(bfd->fd);
|
|
LOGP(DLMI, LOGL_ERROR, "rs232: could not register FD: %s\n",
|
|
strerror(-rc));
|
|
return rc;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int rs232_line_update(struct e1inp_line *line);
|
|
|
|
static struct e1inp_driver rs232_driver = {
|
|
.name = "rs232",
|
|
.want_write = rs232_want_write,
|
|
.line_update = rs232_line_update,
|
|
};
|
|
|
|
static int rs232_line_update(struct e1inp_line *line)
|
|
{
|
|
if (line->driver != &rs232_driver)
|
|
return -EINVAL;
|
|
|
|
return rs232_setup(line, line->ops->cfg.rs232.port,
|
|
line->ops->cfg.rs232.delay);
|
|
}
|
|
|
|
int e1inp_rs232_init(void)
|
|
{
|
|
return e1inp_driver_register(&rs232_driver);
|
|
}
|