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-rw-r--r--src/utils/rs232.c248
1 files changed, 248 insertions, 0 deletions
diff --git a/src/utils/rs232.c b/src/utils/rs232.c
new file mode 100644
index 00000000..75505710
--- /dev/null
+++ b/src/utils/rs232.c
@@ -0,0 +1,248 @@
+/* OpenBSC BS-11 T-Link interface using POSIX serial port */
+
+/* (C) 2008-2009 by Harald Welte <laforge@gnumonks.org>
+ *
+ * All Rights Reserved
+ *
+ * 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 <osmocore/select.h>
+#include <osmocore/msgb.h>
+#include <openbsc/debug.h>
+#include <openbsc/gsm_data.h>
+#include <openbsc/rs232.h>
+
+/* adaption layer from GSM 08.59 + 12.21 to RS232 */
+
+struct serial_handle {
+ struct bsc_fd fd;
+ struct llist_head tx_queue;
+
+ struct msgb *rx_msg;
+ unsigned int rxmsg_bytes_missing;
+
+ unsigned int delay_ms;
+ struct gsm_bts *bts;
+};
+
+/* FIXME: this needs to go */
+static struct serial_handle _ser_handle, *ser_handle = &_ser_handle;
+
+#define LAPD_HDR_LEN 10
+
+static int handle_ser_write(struct bsc_fd *bfd);
+
+/* callback from abis_nm */
+int _abis_nm_sendmsg(struct msgb *msg, int to_trx_oml)
+{
+ struct serial_handle *sh = ser_handle;
+ u_int8_t *lapd;
+ unsigned int len;
+
+ msg->l2h = msg->data;
+
+ /* prepend LAPD header */
+ lapd = msgb_push(msg, LAPD_HDR_LEN);
+
+ len = msg->len - 2;
+
+ lapd[0] = (len >> 8) & 0xff;
+ lapd[1] = len & 0xff; /* length of bytes startign at lapd[2] */
+ lapd[2] = 0x00;
+ lapd[3] = 0x07;
+ lapd[4] = 0x01;
+ lapd[5] = 0x3e;
+ lapd[6] = 0x00;
+ lapd[7] = 0x00;
+ lapd[8] = msg->len - 10; /* length of bytes starting at lapd[10] */
+ lapd[9] = lapd[8] ^ 0x38;
+
+ msgb_enqueue(&sh->tx_queue, msg);
+ sh->fd.when |= BSC_FD_WRITE;
+
+ /* we try to immediately send */
+ handle_ser_write(&sh->fd);
+
+ return 0;
+}
+
+/* select.c callback in case we can write to the RS232 */
+static int handle_ser_write(struct bsc_fd *bfd)
+{
+ struct serial_handle *sh = bfd->data;
+ struct msgb *msg;
+ int written;
+
+ msg = msgb_dequeue(&sh->tx_queue);
+ if (!msg) {
+ bfd->when &= ~BSC_FD_WRITE;
+ return 0;
+ }
+
+ DEBUGP(DMI, "RS232 TX: %s\n", hexdump(msg->data, msg->len));
+
+ /* send over serial line */
+ written = write(bfd->fd, msg->data, msg->len);
+ if (written < msg->len) {
+ perror("short write:");
+ 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 bsc_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;
+ sh->rx_msg->trx = sh->bts->c0;
+ }
+ msg = sh->rx_msg;
+
+ /* first read two byes to obtain length */
+ if (msg->len < 2) {
+ rc = read(sh->fd.fd, msg->tail, 2 - msg->len);
+ if (rc < 0) {
+ perror("ERROR reading from serial port");
+ msgb_free(msg);
+ return rc;
+ }
+ msgb_put(msg, rc);
+
+ if (msg->len >= 2) {
+ /* parse LAPD payload length */
+ if (msg->data[0] != 0)
+ fprintf(stderr, "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 < LAPD_HDR_LEN -2)
+ fprintf(stderr, "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(sh->fd.fd, msg->tail, sh->rxmsg_bytes_missing);
+ if (rc < 0) {
+ perror("ERROR reading from serial port");
+ msgb_free(msg);
+ return rc;
+ }
+ msgb_put(msg, rc);
+ sh->rxmsg_bytes_missing -= rc;
+
+ if (sh->rxmsg_bytes_missing == 0) {
+ /* we have one complete message now */
+ sh->rx_msg = NULL;
+
+ if (msg->len > LAPD_HDR_LEN)
+ msg->l2h = msg->data + LAPD_HDR_LEN;
+
+ DEBUGP(DMI, "RS232 RX: %s\n", hexdump(msg->data, msg->len));
+ rc = handle_serial_msg(msg);
+ }
+ }
+
+ return rc;
+}
+
+/* select.c callback */
+static int serial_fd_cb(struct bsc_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;
+}
+
+int rs232_setup(const char *serial_port, unsigned int delay_ms,
+ struct gsm_bts *bts)
+{
+ int rc, serial_fd;
+ struct termios tio;
+
+ serial_fd = open(serial_port, O_RDWR);
+ if (serial_fd < 0) {
+ perror("cannot open serial port:");
+ return serial_fd;
+ }
+
+ /* set baudrate */
+ rc = tcgetattr(serial_fd, &tio);
+ if (rc < 0) {
+ perror("tcgetattr()");
+ 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(serial_fd, TCSADRAIN, &tio);
+ if (rc < 0) {
+ perror("tcsetattr()");
+ return rc;
+ }
+
+ INIT_LLIST_HEAD(&ser_handle->tx_queue);
+ ser_handle->fd.fd = serial_fd;
+ ser_handle->fd.when = BSC_FD_READ;
+ ser_handle->fd.cb = serial_fd_cb;
+ ser_handle->fd.data = ser_handle;
+ ser_handle->delay_ms = delay_ms;
+ ser_handle->bts = bts;
+ rc = bsc_register_fd(&ser_handle->fd);
+ if (rc < 0) {
+ fprintf(stderr, "could not register FD: %s\n",
+ strerror(rc));
+ return rc;
+ }
+
+ return 0;
+}