input: add rs232 driver for virtual E1 lines
This patch adds the rs232 driver which is used by then bs11_config
utility available in openBSC.
diff --git a/src/e1_input.c b/src/e1_input.c
index 47d58ca..22f38d8 100644
--- a/src/e1_input.c
+++ b/src/e1_input.c
@@ -643,6 +643,7 @@
void e1inp_dahdi_init(void);
void e1inp_ipaccess_init(void);
void e1inp_hsl_init(void);
+void e1inp_rs232_init(void);
void e1inp_init(void)
{
@@ -655,4 +656,5 @@
e1inp_dahdi_init();
e1inp_ipaccess_init();
e1inp_hsl_init();
+ e1inp_rs232_init();
}
diff --git a/src/input/Makefile.am b/src/input/Makefile.am
index c382269..9937465 100644
--- a/src/input/Makefile.am
+++ b/src/input/Makefile.am
@@ -9,4 +9,5 @@
ipa.c \
ipaccess.c \
lapd.c \
- misdn.c
+ misdn.c \
+ rs232.c
diff --git a/src/input/rs232.c b/src/input/rs232.c
new file mode 100644
index 0000000..eb6b5d0
--- /dev/null
+++ b/src/input/rs232.c
@@ -0,0 +1,301 @@
+/* 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>
+ *
+ * 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,
+ enum e1inp_line_role role, const char *addr);
+
+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,
+ enum e1inp_line_role role, const char *addr)
+{
+ if (line->driver != &rs232_driver)
+ return -EINVAL;
+
+ return rs232_setup(line, addr, 0);
+}
+
+int e1inp_rs232_init(void)
+{
+ return e1inp_driver_register(&rs232_driver);
+}