e1d: Initial osmo-e1d support

osmo-e1d is part of the Osmocom 'software defined E1 interface,
which consists of a USB device for the actual E1 hardware interfacing,
and a daemon (osmo-e1d) implementing a libusb-based driver.

This commit adds initial support for talking to osmo-e1d using
the related libosmoe1d library.  You need to use '--enable-e1d'
at configure time to enable it.

Change-Id: Ia0431c124e3b5b4108aee7b109d8c4bb0d8b45d4
Signed-off-by: Sylvain Munaut <tnt@246tNt.com>

6 files changed, 312 insertions, 3 deletions

diff --git a/configure.ac b/configure.ac
index 5a83eb1..35b8328 100644
--- a/configure.ac
+++ b/configure.ac
@@ -75,6 +75,27 @@ else
 	AC_MSG_WARN([DAHDI input driver will not be built])
 fi
 
+AC_ARG_ENABLE([e1d],
+	[AS_HELP_STRING(
+		[--enable-e1d],
+		[Enable osmo-e1d driver support]
+	)],
+	[
+		ENABLE_E1D=$enableval
+	],
+	[
+		ENABLE_E1D="no"
+	])
+AS_IF([test "x$ENABLE_E1D" = "xyes"], [
+	PKG_CHECK_MODULES(LIBOSMOE1D, libosmo-e1d)
+])
+AM_CONDITIONAL(ENABLE_E1D, test "x$ENABLE_E1D" = "xyes")
+AC_SUBST(ENABLE_E1D)
+if test x"$ENABLE_E1D" = x"yes"
+then
+        AC_DEFINE([HAVE_E1D], [1], [Enable osmo-e1d driver support])
+fi
+
 AC_ARG_ENABLE(sanitize,
 	[AS_HELP_STRING(
 		[--enable-sanitize],
diff --git a/include/osmocom/abis/e1_input.h b/include/osmocom/abis/e1_input.h
index de1c504..00b4aaa 100644
--- a/include/osmocom/abis/e1_input.h
+++ b/include/osmocom/abis/e1_input.h
@@ -129,6 +129,10 @@ struct e1inp_ts {
 			struct osmo_fd fd;
 		} dahdi;
 		struct {
+			/* osmo-e1d driver has one fd for each ts */
+			struct osmo_fd fd;
+		} e1d;
+		struct {
 			struct osmo_fd fd;
 		} rs232;
 	} driver;
diff --git a/src/Makefile.am b/src/Makefile.am
index 5ae94e4..3838a5a 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -5,9 +5,9 @@ ABIS_LIBVERSION=8:0:2
 TRAU_LIBVERSION=4:0:2
 
 AM_CPPFLAGS = $(all_includes) -I$(top_srcdir)/include -I$(top_builddir)
-AM_CFLAGS= -Wall $(LIBOSMOCORE_CFLAGS) $(LIBOSMOGSM_CFLAGS) $(LIBOSMOVTY_CFLAGS) $(COVERAGE_CFLAGS)
+AM_CFLAGS= -Wall $(LIBOSMOCORE_CFLAGS) $(LIBOSMOGSM_CFLAGS) $(LIBOSMOVTY_CFLAGS) $(LIBOSMOE1D_CFLAGS) $(COVERAGE_CFLAGS)
 AM_LDFLAGS = $(COVERAGE_LDFLAGS)
-COMMONLIBS = $(LIBOSMOCORE_LIBS) $(LIBOSMOGSM_LIBS) $(LIBOSMOVTY_LIBS)
+COMMONLIBS = $(LIBOSMOCORE_LIBS) $(LIBOSMOGSM_LIBS) $(LIBOSMOVTY_LIBS) $(LIBOSMOE1D_LIBS)
 
 lib_LTLIBRARIES = libosmoabis.la libosmotrau.la
 
@@ -19,6 +19,7 @@ libosmoabis_la_SOURCES = init.c \
 			 ipa_proxy.c \
 			 subchan_demux.c \
 			 trau_frame.c \
+			 input/e1d.c \
 			 input/ipa.c \
 			 input/ipa_keepalive.c \
 			 input/ipaccess.c \
diff --git a/src/e1_input.c b/src/e1_input.c
index a707438..cb1612d 100644
--- a/src/e1_input.c
+++ b/src/e1_input.c
@@ -890,6 +890,9 @@ void e1inp_init(void)
 #ifdef HAVE_DAHDI_USER_H
 	e1inp_dahdi_init();
 #endif
+#ifdef ENABLE_E1D
+	e1inp_e1d_init();
+#endif
 	e1inp_ipaccess_init();
 	e1inp_rs232_init();
 	e1inp_unixsocket_init();
diff --git a/src/e1_input_vty.c b/src/e1_input_vty.c
index d81c859..a1943e6 100644
--- a/src/e1_input_vty.c
+++ b/src/e1_input_vty.c
@@ -41,7 +41,7 @@
 
 /* CONFIG */
 
-#define E1_DRIVER_NAMES		"(misdn|misdn_lapd|dahdi|ipa|unixsocket)"
+#define E1_DRIVER_NAMES		"(misdn|misdn_lapd|dahdi|e1d|ipa|unixsocket)"
 #define E1_DRIVER_HELP		"mISDN supported E1 Card (kernel LAPD)\n" \
 				"mISDN supported E1 Card (userspace LAPD)\n" \
 				"DAHDI supported E1/T1/J1 Card\n" \
diff --git a/src/input/e1d.c b/src/input/e1d.c
new file mode 100644
index 0000000..ceeb0c2
--- /dev/null
+++ b/src/input/e1d.c
@@ -0,0 +1,280 @@
+/* OpenBSC Abis input driver for osmo-e1d */
+
+/* (C) 2019 by Sylvain Munaut <tnt@246tNt.com>
+ *
+ * All Rights Reserved
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include "config.h"
+
+#ifdef HAVE_E1D
+
+#include <errno.h>
+#include <unistd.h>
+#include <string.h>
+
+#include <osmocom/core/bits.h>
+#include <osmocom/core/logging.h>
+
+#include <osmocom/vty/vty.h>
+
+#include <osmocom/abis/subchan_demux.h>
+#include <osmocom/abis/e1_input.h>
+#include <osmocom/abis/lapd.h>
+
+#include <osmocom/e1d/proto.h>
+#include <osmocom/e1d/proto_clnt.h>
+
+
+#define TS_SIGN_ALLOC_SIZE  300
+
+struct osmo_e1dp_client *g_e1d;
+
+/* pre-declaration */
+extern struct e1inp_driver e1d_driver;
+static int e1d_want_write(struct e1inp_ts *e1i_ts);
+
+
+static int
+handle_ts_sign_read(struct osmo_fd *bfd)
+{
+        struct e1inp_line *line = bfd->data;
+        unsigned int ts_nr = bfd->priv_nr;
+        struct e1inp_ts *e1i_ts = &line->ts[ts_nr-1];
+	struct msgb *msg = msgb_alloc(TS_SIGN_ALLOC_SIZE, "E1D Signaling TS");
+	int ret;
+
+	if (!msg)
+		return -ENOMEM;
+
+	ret = read(bfd->fd, msg->data, TS_SIGN_ALLOC_SIZE - 16);
+	if (ret < 0) {
+		perror("read ");
+		return ret;
+	}
+
+	msgb_put(msg, ret);
+	if (ret <= 1) {
+		perror("read ");
+		return ret;
+	}
+
+        return e1inp_rx_ts_lapd(e1i_ts, msg);
+}
+
+static void
+timeout_ts_sign_write(void *data)
+{
+	struct e1inp_ts *e1i_ts = (struct e1inp_ts *)data;
+
+	/* trigger write of ts1, due to tx delay timer */
+	e1d_want_write(e1i_ts);
+}
+
+static int
+handle_ts_sign_write(struct osmo_fd *bfd)
+{
+        struct e1inp_line *line = bfd->data;
+        unsigned int ts_nr = bfd->priv_nr;
+        struct e1inp_ts *e1i_ts = &line->ts[ts_nr-1];
+	struct e1inp_sign_link *sign_link;
+	struct msgb *msg;
+
+	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, "TX: %s\n", osmo_hexdump(msg->data, msg->len));
+	lapd_transmit(e1i_ts->lapd, sign_link->tei,
+		sign_link->sapi, msg);
+
+	/* set tx delay timer for next event */
+	osmo_timer_setup(&e1i_ts->sign.tx_timer, timeout_ts_sign_write, e1i_ts);
+	osmo_timer_schedule(&e1i_ts->sign.tx_timer, 0, 50000);
+
+	return 0;
+}
+
+
+static void
+e1d_write_msg(struct msgb *msg, void *cbdata)
+{
+	struct osmo_fd *bfd = cbdata;
+	struct e1inp_line *line = bfd->data;
+	unsigned int ts_nr = bfd->priv_nr;
+	struct e1inp_ts *e1i_ts = &line->ts[ts_nr-1];
+	int ret;
+
+	ret = write(bfd->fd, msg->data, msg->len);
+	msgb_free(msg);
+	if (ret < 0)
+		LOGP(DLMI, LOGL_NOTICE, "%s write failed %d\n", __func__, ret);
+}
+
+static int
+e1d_fd_cb(struct osmo_fd *bfd, unsigned int what)
+{
+        struct e1inp_line *line = bfd->data;
+        unsigned int ts_nr = bfd->priv_nr;
+        unsigned int idx = ts_nr-1;
+        struct e1inp_ts *e1i_ts = &line->ts[idx];
+	int ret = 0;
+
+	switch (e1i_ts->type) {
+	case E1INP_TS_TYPE_SIGN:
+		//if (what & BSC_FD_EXCEPT)
+		//FIXME: what to do ?!?!
+		if (what & BSC_FD_READ)
+			ret = handle_ts_sign_read(bfd);
+		if (what & BSC_FD_WRITE)
+			ret = handle_ts_sign_write(bfd);
+		break;
+	default:
+		LOGP(DLINP, LOGL_NOTICE,
+			"unknown/unsupported E1 TS type %u\n", e1i_ts->type);
+		break;
+	}
+
+	return ret;
+}
+
+
+static int
+e1d_want_write(struct e1inp_ts *e1i_ts)
+{
+        /* We never include the DAHDI B-Channel FD into the writeset */
+	if (e1i_ts->type == E1INP_TS_TYPE_TRAU) {
+		LOGP(DLINP, LOGL_DEBUG, "Trying to write TRAU ts\n");
+		return 0;
+	}
+
+	e1i_ts->driver.e1d.fd.when |= BSC_FD_WRITE;
+
+	return 0;
+}
+
+static int
+e1d_line_update(struct e1inp_line *line)
+{
+	int ts;
+	int ret;
+
+	if (line->driver != &e1d_driver)
+		return -EINVAL;
+
+
+	LOGP(DLINP, LOGL_ERROR, "Line update %d %d %d\n", line->num, line->port_nr, line->num_ts);
+
+	for (ts=1; ts<line->num_ts; ts++)
+	{
+		unsigned int idx = ts-1;
+		struct e1inp_ts *e1i_ts = &line->ts[idx];
+		struct osmo_fd *bfd = &e1i_ts->driver.e1d.fd;
+
+		/* unregister FD if it was already registered */
+		if (bfd->list.next && bfd->list.next != LLIST_POISON1)
+			osmo_fd_unregister(bfd);
+
+		bfd->data = line;
+		bfd->priv_nr = ts;
+		bfd->cb = e1d_fd_cb;
+
+		switch (e1i_ts->type) {
+		case E1INP_TS_TYPE_NONE:
+			/* close/release LAPD instance, if any */
+			if (e1i_ts->lapd) {
+				lapd_instance_free(e1i_ts->lapd);
+				e1i_ts->lapd = NULL;
+			}
+			if (bfd->fd) {
+				close(bfd->fd);
+				bfd->fd = 0;
+			}
+                        continue;
+		case E1INP_TS_TYPE_SIGN:
+			if (bfd->fd <= 0)
+				bfd->fd = osmo_e1dp_client_ts_open(g_e1d, 0, 0, ts, E1DP_TSMODE_HDLCFCS);
+			if (bfd->fd < 0) {
+				LOGP(DLINP, LOGL_ERROR,
+					"Could not open timeslot %d\n", ts);
+				return -EIO;
+			}
+			bfd->when = BSC_FD_READ | BSC_FD_EXCEPT;
+
+			if (!e1i_ts->lapd)
+				e1i_ts->lapd = lapd_instance_alloc(1,
+					e1d_write_msg, bfd, e1inp_dlsap_up,
+					e1i_ts, &lapd_profile_abis);
+			break;
+		case E1INP_TS_TYPE_HDLC:
+			break;
+		case E1INP_TS_TYPE_TRAU:
+			break;
+		case E1INP_TS_TYPE_RAW:
+			break;
+		};
+
+		ret = osmo_fd_register(bfd);
+		if (ret < 0) {
+			LOGP(DLINP, LOGL_ERROR,
+				"could not register FD: %s\n",
+				strerror(ret));
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static void
+e1d_vty_show(struct vty *vty, struct e1inp_line *line)
+{
+	/* FIXME */
+	vty_out(vty, "Not supported yet%s", VTY_NEWLINE);
+}
+
+
+struct e1inp_driver e1d_driver = {
+	.name        = "e1d",
+	.want_write  = e1d_want_write,
+	.line_update = e1d_line_update,
+	.vty_show    = e1d_vty_show,
+};
+
+int
+e1inp_e1d_init(void)
+{
+	/* Connect to daemon */
+	g_e1d = osmo_e1dp_client_create(NULL, "/tmp/osmo-e1d.ctl");
+	if (!g_e1d) {
+		 LOGP(DLINP, LOGL_ERROR, "Unable to connect to osmo-e1d daemon\n");
+		return -EPIPE;
+	}
+
+	/* register the driver with the core */
+	return e1inp_driver_register(&e1d_driver);
+}
+
+#endif /* HAVE_E1D */