Initial code import

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

21 files changed, 2993 insertions, 0 deletions

diff --git a/COPYING b/COPYING
new file mode 100644
index 0000000..42329c4
--- /dev/null
+++ b/COPYING
@@ -0,0 +1,9 @@
+See COPYING.* for the full licenses.
+
+The libosmo-e1d library is licensed under the terms of the GNU Lesser General
+Public License as published by the Free Software Foundation, either version 3
+of the License, or (at your option) any later version.
+
+The osmo-e1d daemon is licensed 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.
diff --git a/COPYING.gpl2 b/COPYING.gpl2
new file mode 100644
index 0000000..d159169
--- /dev/null
+++ b/COPYING.gpl2
@@ -0,0 +1,339 @@
+                    GNU GENERAL PUBLIC LICENSE
+                       Version 2, June 1991
+
+ Copyright (C) 1989, 1991 Free Software Foundation, Inc.,
+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
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+   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
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diff --git a/COPYING.lgpl3 b/COPYING.lgpl3
new file mode 100644
index 0000000..0a04128
--- /dev/null
+++ b/COPYING.lgpl3
@@ -0,0 +1,165 @@
+                   GNU LESSER GENERAL PUBLIC LICENSE
+                       Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc. <https://fsf.org/>
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+
+  This version of the GNU Lesser General Public License incorporates
+the terms and conditions of version 3 of the GNU General Public
+License, supplemented by the additional permissions listed below.
+
+  0. Additional Definitions.
+
+  As used herein, "this License" refers to version 3 of the GNU Lesser
+General Public License, and the "GNU GPL" refers to version 3 of the GNU
+General Public License.
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+  "The Library" refers to a covered work governed by this License,
+other than an Application or a Combined Work as defined below.
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+   Library is used in it and that the Library and its use are
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+  4. Combined Works.
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+  You may convey a Combined Work under terms of your choice that,
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diff --git a/Makefile.am b/Makefile.am
new file mode 100644
index 0000000..9862cd8
--- /dev/null
+++ b/Makefile.am
@@ -0,0 +1,21 @@
+AUTOMAKE_OPTIONS = foreign dist-bzip2
+
+SUBDIRS = \
+	src \
+	include \
+	$(NULL)
+
+EXTRA_DIST = \
+	.version \
+	$(NULL)
+
+pkgconfigdir = $(libdir)/pkgconfig
+pkgconfig_DATA = libosmo-e1d.pc
+
+@RELMAKE@
+
+BUILT_SOURCES = $(top_srcdir)/.version
+$(top_srcdir)/.version:
+	echo $(VERSION) > $@-t && mv $@-t $@
+dist-hook:
+	echo $(VERSION) > $(distdir)/.tarball-version
diff --git a/configure.ac b/configure.ac
new file mode 100644
index 0000000..91d34e8
--- /dev/null
+++ b/configure.ac
@@ -0,0 +1,78 @@
+AC_INIT([osmo-e1d],
+	m4_esyscmd([./git-version-gen .tarball-version]),
+	[openbsc@lists.osmocom.org])
+
+dnl *This* is the root dir, even if an install-sh exists in ../ or ../../
+AC_CONFIG_AUX_DIR([.])
+
+dnl libtool init
+LT_INIT
+
+AM_INIT_AUTOMAKE([foreign dist-bzip2 no-dist-gzip 1.9])
+
+dnl kernel style compile messages
+m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])])
+
+dnl include release helper
+RELMAKE='-include osmo-release.mk'
+AC_SUBST([RELMAKE])
+
+dnl checks for programs
+AC_PROG_MAKE_SET
+AC_PROG_MKDIR_P
+AC_PROG_CC
+AC_PROG_INSTALL
+
+dnl check for pkg-config (explained in detail in libosmocore/configure.ac)
+AC_PATH_PROG(PKG_CONFIG_INSTALLED, pkg-config, no)
+if test "x$PKG_CONFIG_INSTALLED" = "xno"; then
+        AC_MSG_WARN([You need to install pkg-config])
+fi
+PKG_PROG_PKG_CONFIG([0.20])
+
+PKG_CHECK_MODULES(TALLOC, [talloc >= 2.0.1])
+
+PKG_CHECK_MODULES(LIBOSMOCORE, libosmocore >= 1.0.1.120)
+PKG_CHECK_MODULES(LIBUSB, libusb-1.0 >= 1.0.21)
+
+AC_CONFIG_MACRO_DIR([m4])
+
+dnl checks for header files
+AC_HEADER_STDC
+
+AC_ARG_ENABLE(sanitize,
+	[AS_HELP_STRING(
+		[--enable-sanitize],
+		[Compile with address sanitizer enabled],
+	)],
+	[sanitize=$enableval], [sanitize="no"])
+if test x"$sanitize" = x"yes"
+then
+	CFLAGS="$CFLAGS -fsanitize=address -fsanitize=undefined"
+	CPPFLAGS="$CPPFLAGS -fsanitize=address -fsanitize=undefined"
+fi
+
+AC_ARG_ENABLE(werror,
+	[AS_HELP_STRING(
+		[--enable-werror],
+		[Turn all compiler warnings into errors, with exceptions:
+		 a) deprecation (allow upstream to mark deprecation without breaking builds);
+		 b) "#warning" pragmas (allow to remind ourselves of errors without breaking builds)
+		]
+	)],
+	[werror=$enableval], [werror="no"])
+if test x"$werror" = x"yes"
+then
+	WERROR_FLAGS="-Werror"
+	WERROR_FLAGS+=" -Wno-error=deprecated -Wno-error=deprecated-declarations"
+	WERROR_FLAGS+=" -Wno-error=cpp" # "#warning"
+	CFLAGS="$CFLAGS $WERROR_FLAGS"
+	CPPFLAGS="$CPPFLAGS $WERROR_FLAGS"
+fi
+
+AC_OUTPUT(
+	Makefile
+	src/Makefile
+	include/Makefile
+	libosmo-e1d.pc
+	)
diff --git a/git-version-gen b/git-version-gen
new file mode 100755
index 0000000..42cf3d2
--- /dev/null
+++ b/git-version-gen
@@ -0,0 +1,151 @@
+#!/bin/sh
+# Print a version string.
+scriptversion=2010-01-28.01
+
+# Copyright (C) 2007-2010 Free Software Foundation, Inc.
+#
+# 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 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 General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# This script is derived from GIT-VERSION-GEN from GIT: http://git.or.cz/.
+# It may be run two ways:
+# - from a git repository in which the "git describe" command below
+#   produces useful output (thus requiring at least one signed tag)
+# - from a non-git-repo directory containing a .tarball-version file, which
+#   presumes this script is invoked like "./git-version-gen .tarball-version".
+
+# In order to use intra-version strings in your project, you will need two
+# separate generated version string files:
+#
+# .tarball-version - present only in a distribution tarball, and not in
+#   a checked-out repository.  Created with contents that were learned at
+#   the last time autoconf was run, and used by git-version-gen.  Must not
+#   be present in either $(srcdir) or $(builddir) for git-version-gen to
+#   give accurate answers during normal development with a checked out tree,
+#   but must be present in a tarball when there is no version control system.
+#   Therefore, it cannot be used in any dependencies.  GNUmakefile has
+#   hooks to force a reconfigure at distribution time to get the value
+#   correct, without penalizing normal development with extra reconfigures.
+#
+# .version - present in a checked-out repository and in a distribution
+#   tarball.  Usable in dependencies, particularly for files that don't
+#   want to depend on config.h but do want to track version changes.
+#   Delete this file prior to any autoconf run where you want to rebuild
+#   files to pick up a version string change; and leave it stale to
+#   minimize rebuild time after unrelated changes to configure sources.
+#
+# It is probably wise to add these two files to .gitignore, so that you
+# don't accidentally commit either generated file.
+#
+# Use the following line in your configure.ac, so that $(VERSION) will
+# automatically be up-to-date each time configure is run (and note that
+# since configure.ac no longer includes a version string, Makefile rules
+# should not depend on configure.ac for version updates).
+#
+# AC_INIT([GNU project],
+#         m4_esyscmd([build-aux/git-version-gen .tarball-version]),
+#         [bug-project@example])
+#
+# Then use the following lines in your Makefile.am, so that .version
+# will be present for dependencies, and so that .tarball-version will
+# exist in distribution tarballs.
+#
+# BUILT_SOURCES = $(top_srcdir)/.version
+# $(top_srcdir)/.version:
+#	echo $(VERSION) > $@-t && mv $@-t $@
+# dist-hook:
+#	echo $(VERSION) > $(distdir)/.tarball-version
+
+case $# in
+    1) ;;
+    *) echo 1>&2 "Usage: $0 \$srcdir/.tarball-version"; exit 1;;
+esac
+
+tarball_version_file=$1
+nl='
+'
+
+# First see if there is a tarball-only version file.
+# then try "git describe", then default.
+if test -f $tarball_version_file
+then
+    v=`cat $tarball_version_file` || exit 1
+    case $v in
+	*$nl*) v= ;; # reject multi-line output
+	[0-9]*) ;;
+	*) v= ;;
+    esac
+    test -z "$v" \
+	&& echo "$0: WARNING: $tarball_version_file seems to be damaged" 1>&2
+fi
+
+if test -n "$v"
+then
+    : # use $v
+elif
+       v=`git describe --abbrev=4 --match='v*' HEAD 2>/dev/null \
+	  || git describe --abbrev=4 HEAD 2>/dev/null` \
+    && case $v in
+	 [0-9]*) ;;
+	 v[0-9]*) ;;
+	 *) (exit 1) ;;
+       esac
+then
+    # Is this a new git that lists number of commits since the last
+    # tag or the previous older version that did not?
+    #   Newer: v6.10-77-g0f8faeb
+    #   Older: v6.10-g0f8faeb
+    case $v in
+	*-*-*) : git describe is okay three part flavor ;;
+	*-*)
+	    : git describe is older two part flavor
+	    # Recreate the number of commits and rewrite such that the
+	    # result is the same as if we were using the newer version
+	    # of git describe.
+	    vtag=`echo "$v" | sed 's/-.*//'`
+	    numcommits=`git rev-list "$vtag"..HEAD | wc -l`
+	    v=`echo "$v" | sed "s/\(.*\)-\(.*\)/\1-$numcommits-\2/"`;
+	    ;;
+    esac
+
+    # Change the first '-' to a '.', so version-comparing tools work properly.
+    # Remove the "g" in git describe's output string, to save a byte.
+    v=`echo "$v" | sed 's/-/./;s/\(.*\)-g/\1-/'`;
+else
+    v=UNKNOWN
+fi
+
+v=`echo "$v" |sed 's/^v//'`
+
+# Don't declare a version "dirty" merely because a time stamp has changed.
+git status > /dev/null 2>&1
+
+dirty=`sh -c 'git diff-index --name-only HEAD' 2>/dev/null` || dirty=
+case "$dirty" in
+    '') ;;
+    *) # Append the suffix only if there isn't one already.
+	case $v in
+	  *-dirty) ;;
+	  *) v="$v-dirty" ;;
+	esac ;;
+esac
+
+# Omit the trailing newline, so that m4_esyscmd can use the result directly.
+echo "$v" | tr -d '\012'
+
+# Local variables:
+# eval: (add-hook 'write-file-hooks 'time-stamp)
+# time-stamp-start: "scriptversion="
+# time-stamp-format: "%:y-%02m-%02d.%02H"
+# time-stamp-end: "$"
+# End:
diff --git a/include/Makefile.am b/include/Makefile.am
new file mode 100644
index 0000000..e74dd6e
--- /dev/null
+++ b/include/Makefile.am
@@ -0,0 +1 @@
+nobase_include_HEADERS = osmocom/e1d/proto_clnt.h  osmocom/e1d/proto.h  osmocom/e1d/proto_srv.h
diff --git a/include/osmocom/e1d/proto.h b/include/osmocom/e1d/proto.h
new file mode 100644
index 0000000..a3c94bb
--- /dev/null
+++ b/include/osmocom/e1d/proto.h
@@ -0,0 +1,109 @@
+/*
+ * proto.h
+ *
+ * (C) 2019 by Sylvain Munaut <tnt@246tNt.com>
+ *
+ * All Rights Reserved
+ *
+ * SPDX-License-Identifier: LGPL-3.0-or-later
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser 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 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.
+ */
+
+#pragma once
+
+#include <stdint.h>
+
+#include <osmocom/core/select.h>
+
+
+/*	E1DP_CMD_INTF_QUERY
+ *	filter: intf (optional)
+ *	in: n/a
+ *	out: array of osmo_e1dp_intf_info
+ *
+ * 	E1DP_CMD_LINE_QUERY
+ * 	filter: intf (required), line (optional)
+ * 	in: n/a
+ * 	out: array of osmo_e1dp_line_info
+ *
+ * 	E1DP_CMD_TS_QUERY
+ * 	filter: intf (required), line (required), ts (optional)
+ * 	in: n/a
+ * 	out: array of osmo_e1dp_ts_info
+ *
+ * 	E1DP_CMD_TS_OPEN
+ * 	filter: intf (required), line (required), ts (required)
+ * 	in: osmo_e1dp_ts_config
+ * 	out: osmo_e1dp_ts_info with the opened TS (or an invalid one with id == -1 for errors)
+ * 	    + message with the file descriptor
+ */
+
+enum osmo_e1dp_msg_type {
+	E1DP_CMD_INTF_QUERY	= 0x00,
+	E1DP_CMD_LINE_QUERY	= 0x01,
+	E1DP_CMD_TS_QUERY	= 0x02,
+	E1DP_CMD_TS_OPEN	= 0x04,
+	E1DP_EVT_TYPE		= 0x40,
+	E1DP_RESP_TYPE		= 0x80,
+	E1DP_ERR_TYPE		= 0xc0,
+	E1DP_TYPE_MSK		= 0xc0,
+};
+
+enum osmo_e1dp_ts_mode {
+	E1DP_TSMODE_OFF		= 0x00,
+	E1DP_TSMODE_RAW		= 0x10,
+	E1DP_TSMODE_HDLCFCS	= 0x11,
+};
+
+
+#define E1DP_MAGIC	0x00e1
+#define E1DP_MAX_LEN	4096
+#define E1DP_INVALID	0xff
+
+
+struct osmo_e1dp_msg_hdr {
+	uint16_t magic;
+	uint16_t len;
+
+	uint8_t  type; 
+	uint8_t  intf;
+	uint8_t  line;
+	uint8_t  ts;
+} __attribute__((packed));
+
+struct osmo_e1dp_intf_info {
+	uint8_t id;
+	uint8_t n_lines;
+} __attribute__((packed));
+
+struct osmo_e1dp_line_info {
+	uint8_t id;
+	uint8_t status;		/* TBD */
+} __attribute__((packed));
+
+struct osmo_e1dp_ts_config {
+	uint8_t mode;
+} __attribute__((packed));
+
+struct osmo_e1dp_ts_info {
+	uint8_t id;
+	struct osmo_e1dp_ts_config cfg;
+	uint8_t status;		/* TBD */
+} __attribute__((packed));
+
+
+struct msgb *osmo_e1dp_recv(struct osmo_fd *ofd, int *fd);
+int osmo_e1dp_send(struct osmo_fd *ofd, struct msgb *msgb, int fd);
diff --git a/include/osmocom/e1d/proto_clnt.h b/include/osmocom/e1d/proto_clnt.h
new file mode 100644
index 0000000..9288af9
--- /dev/null
+++ b/include/osmocom/e1d/proto_clnt.h
@@ -0,0 +1,47 @@
+/*
+ * proto_clnt.h
+ *
+ * (C) 2019 by Sylvain Munaut <tnt@246tNt.com>
+ *
+ * All Rights Reserved
+ *
+ * SPDX-License-Identifier: LGPL-3.0-or-later
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser 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 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.
+ */
+
+#pragma once
+
+#include <osmocom/core/msgb.h>
+
+#include <osmocom/e1d/proto.h>
+
+struct osmo_e1dp_client;
+
+struct osmo_e1dp_client *osmo_e1dp_client_create(void *ctx, const char *path);
+void osmo_e1dp_client_destroy(struct osmo_e1dp_client *srv);
+
+int osmo_e1dp_client_intf_query(struct osmo_e1dp_client *clnt,
+	struct osmo_e1dp_intf_info **ii, int *n,
+	uint8_t intf);
+int osmo_e1dp_client_line_query(struct osmo_e1dp_client *clnt,
+	struct osmo_e1dp_line_info **li, int *n,
+	uint8_t intf, uint8_t line);
+int osmo_e1dp_client_ts_query(struct osmo_e1dp_client *clnt,
+	struct osmo_e1dp_ts_info **ti, int *n,
+	uint8_t intf, uint8_t line, uint8_t ts);
+int osmo_e1dp_client_ts_open(struct osmo_e1dp_client *clnt,
+	uint8_t intf, uint8_t line, uint8_t ts,
+	enum osmo_e1dp_ts_mode mode);
diff --git a/include/osmocom/e1d/proto_srv.h b/include/osmocom/e1d/proto_srv.h
new file mode 100644
index 0000000..c5faec8
--- /dev/null
+++ b/include/osmocom/e1d/proto_srv.h
@@ -0,0 +1,49 @@
+/*
+ * proto_srv.h
+ *
+ * (C) 2019 by Sylvain Munaut <tnt@246tNt.com>
+ *
+ * All Rights Reserved
+ *
+ * SPDX-License-Identifier: LGPL-3.0-or-later
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser 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 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.
+ */
+
+#pragma once
+
+#include <osmocom/core/msgb.h>
+
+struct osmo_e1dp_server;
+
+#define E1DP_SF_INTF_OPT	(1<<0)
+#define E1DP_SF_INTF_REQ	(1<<1)
+#define E1DP_SF_LINE_OPT	(1<<2)
+#define E1DP_SF_LINE_REQ	(1<<3)
+#define E1DP_SF_TS_OPT		(1<<4)
+#define E1DP_SF_TS_REQ		(1<<5)
+
+typedef int (*osmo_e1dp_server_handler_fn)(void *data, struct msgb *msgb, struct msgb *rmsgb, int *rfd);
+
+struct osmo_e1dp_server_handler {
+	uint8_t type;
+	int flags;
+	int payload_len;
+	osmo_e1dp_server_handler_fn fn;
+};
+
+struct osmo_e1dp_server *osmo_e1dp_server_create(void *ctx, const char *path,
+	struct osmo_e1dp_server_handler *handlers, void *handler_data);
+void osmo_e1dp_server_destroy(struct osmo_e1dp_server *srv);
diff --git a/libosmo-e1d.pc.in b/libosmo-e1d.pc.in
new file mode 100644
index 0000000..fc930aa
--- /dev/null
+++ b/libosmo-e1d.pc.in
@@ -0,0 +1,10 @@
+prefix=@prefix@
+exec_prefix=@exec_prefix@
+libdir=@libdir@
+includedir=@includedir@
+
+Name: Osmocom E1 Daemon Protocol Library
+Description: C Utility Library
+Version: @VERSION@
+Libs: -L${libdir} -losmo-e1d
+Cflags: -I${includedir}/
diff --git a/src/Makefile.am b/src/Makefile.am
new file mode 100644
index 0000000..42c4ec8
--- /dev/null
+++ b/src/Makefile.am
@@ -0,0 +1,38 @@
+# This is _NOT_ the library release version, it's an API version.
+# Please read Chapter 6 "Library interface versions" of the libtool
+# documentation before making any modification
+LIBVERSION=0:0:0
+
+AM_CPPFLAGS = $(all_includes) -I$(top_srcdir)/include -I$(top_builddir)
+AM_CFLAGS=-Wall $(LIBOSMOCORE_CFLAGS) $(LIBUSB_CFLAGS)
+
+lib_LTLIBRARIES = libosmo-e1d.la
+
+libosmo_e1d_la_SOURCES = \
+	proto.c \
+	proto_clnt.c \
+	proto_srv.c \
+	$(NULL)
+
+libosmo_e1d_la_LDFLAGS = -version-info $(LIBVERSION) -no-undefined -export-symbols-regex '^osmo_'
+libosmo_e1d_la_LIBADD = $(LIBOSMOCORE_LIBS)
+
+
+noinst_HEADERS = \
+	e1d.h \
+	log.h \
+	$(NULL)
+
+
+bin_PROGRAMS = \
+	osmo-e1d \
+	$(NULL)
+
+osmo_e1d_SOURCES = \
+	ctl.c \
+	log.c \
+	osmo-e1d.c \
+	usb.c \
+	$(NULL)
+
+osmo_e1d_LDADD = $(LIBOSMOCORE_LIBS) $(LIBUSB_LIBS) libosmo-e1d.la
diff --git a/src/ctl.c b/src/ctl.c
new file mode 100644
index 0000000..835811f
--- /dev/null
+++ b/src/ctl.c
@@ -0,0 +1,340 @@
+/*
+ * ctl.c
+ *
+ * (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 <fcntl.h>
+#include <unistd.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/socket.h>
+
+#include <osmocom/core/isdnhdlc.h>
+#include <osmocom/core/msgb.h>
+
+#include <osmocom/e1d/proto.h>
+#include <osmocom/e1d/proto_srv.h>
+
+#include "e1d.h"
+
+
+static struct e1_intf *
+_e1d_find_intf(struct e1_daemon *e1d, uint8_t id)
+{
+	struct e1_intf *intf;
+
+	llist_for_each_entry(intf, &e1d->interfaces, list)
+		if (intf->id == id)
+			return intf;
+
+	return NULL;
+}
+
+static struct e1_line *
+_e1d_find_line(struct e1_intf *intf, uint8_t id)
+{
+	struct e1_line *line;
+
+	llist_for_each_entry(line, &intf->lines, list)
+		if (line->id == id)
+			return line;
+
+	return NULL;
+}
+
+static struct e1_ts *
+_e1d_get_ts(struct e1_line *line, uint8_t ts)
+{
+	return (ts < 32) ? &line->ts[ts] : NULL;
+}
+
+static void
+_e1d_fill_intf_info(struct osmo_e1dp_intf_info *ii, struct e1_intf *intf)
+{
+	ii->id = intf->id;
+	ii->n_lines = llist_count(&intf->lines);
+}
+
+static void
+_e1d_fill_line_info(struct osmo_e1dp_line_info *li, struct e1_line *line)
+{
+	li->id = line->id;
+	li->status = 0x00;
+}
+
+static void
+_e1d_fill_ts_info(struct osmo_e1dp_ts_info *ti, struct e1_ts *ts)
+{
+	ti->id = ts->id;
+	ti->cfg.mode = 0;
+	ti->status = 0;
+}
+
+
+static void
+_e1d_ts_stop(struct e1_ts *ts)
+{
+	ts->mode = E1_TS_MODE_OFF;
+
+	if (ts->fd > 0) {
+		close(ts->fd);
+		ts->fd = -1;
+	}
+}
+
+static int
+_e1d_ts_start(struct e1_ts *ts, enum e1_ts_mode mode)
+{
+	int ret, sd[2];
+
+	ret = socketpair(AF_UNIX, SOCK_SEQPACKET, 0, sd);
+	if (ret < 0)
+		return ret;
+
+	ts->fd = sd[0];
+	ts->mode = mode;
+
+	if (mode == E1_TS_MODE_HDLCFCS) {
+		osmo_isdnhdlc_out_init(&ts->hdlc_tx, OSMO_HDLC_F_BITREVERSE);
+		osmo_isdnhdlc_rcv_init(&ts->hdlc_rx, OSMO_HDLC_F_BITREVERSE);
+	}
+
+	int flags = fcntl(ts->fd, F_GETFL);
+	fcntl(ts->fd, F_SETFL, flags | O_NONBLOCK);
+
+	return sd[1];
+}
+
+
+static int
+_e1d_ctl_intf_query(void *data, struct msgb *msgb, struct msgb *rmsgb, int *rfd)
+{
+	struct e1_daemon *e1d = (struct e1_daemon *)data;
+	struct osmo_e1dp_msg_hdr *hdr = msgb_l1(msgb);
+	struct osmo_e1dp_intf_info *ii;
+	struct e1_intf *intf = NULL;
+	int n;
+
+	/* Process query and find interface */
+	if (hdr->intf != E1DP_INVALID) {
+		intf = _e1d_find_intf(e1d, hdr->intf);
+		n = intf ? 1 : 0;
+	} else {
+		n = llist_count(&e1d->interfaces);
+	}
+
+	if (!n)
+		return 0;
+
+	/* Allocate reponse */
+	rmsgb->l2h = msgb_put(rmsgb, n * sizeof(struct osmo_e1dp_intf_info));
+	ii = msgb_l2(rmsgb);
+
+	memset(ii, 0x00, n * sizeof(struct osmo_e1dp_intf_info));
+
+	/* Fill response */
+	if (intf) {
+		_e1d_fill_intf_info(ii, intf);
+	} else {
+		llist_for_each_entry(intf, &e1d->interfaces, list)
+			_e1d_fill_intf_info(ii++, intf);
+	}
+
+	return 0;
+}
+
+static int
+_e1d_ctl_line_query(void *data, struct msgb *msgb, struct msgb *rmsgb, int *rfd)
+{
+	struct e1_daemon *e1d = (struct e1_daemon *)data;
+	struct osmo_e1dp_msg_hdr *hdr = msgb_l1(msgb);
+	struct osmo_e1dp_line_info *li;
+	struct e1_intf *intf = NULL;
+	struct e1_line *line = NULL;
+	int n;
+	
+	/* Process query and find line */
+	intf = _e1d_find_intf(e1d, hdr->intf);
+	if (!intf)
+		return 0;
+
+	if (hdr->line != E1DP_INVALID) {
+		line = _e1d_find_line(intf, hdr->line);
+		n = line ? 1 : 0;
+	} else{
+		n = llist_count(&intf->lines);
+	}
+
+	if (!n)
+		return 0;
+
+	/* Allocate reponse */
+	rmsgb->l2h = msgb_put(rmsgb, n * sizeof(struct osmo_e1dp_line_info));
+	li = msgb_l2(rmsgb);
+
+	memset(li, 0x00, n * sizeof(struct osmo_e1dp_line_info));
+
+	/* Fill response */
+	if (line) {
+		_e1d_fill_line_info(li, line);
+	} else {
+		llist_for_each_entry(line, &intf->lines, list)
+			_e1d_fill_line_info(li++, line);
+	}
+
+	return 0;
+}
+
+static int
+_e1d_ctl_ts_query(void *data, struct msgb *msgb, struct msgb *rmsgb, int *rfd)
+{
+	struct e1_daemon *e1d = (struct e1_daemon *)data;
+	struct osmo_e1dp_msg_hdr *hdr = msgb_l1(msgb);
+	struct osmo_e1dp_ts_info *ti;
+	struct e1_intf *intf = NULL;
+	struct e1_line *line = NULL;
+	int n;
+
+	/* Process query and find timeslot */
+	intf = _e1d_find_intf(e1d, hdr->intf);
+	if (!intf)
+		return 0;
+
+	line = _e1d_find_line(intf, hdr->line);
+	if (!line)
+		return 0;
+
+	n = (hdr->ts == E1DP_INVALID) ? 32 : (
+		((hdr->ts >= 0) && (hdr->ts < 31)) ? 1 : 0
+	);
+
+	if (!n)
+		return 0;
+
+	/* Allocate reponse */
+	rmsgb->l2h = msgb_put(rmsgb, n * sizeof(struct osmo_e1dp_ts_info));
+	ti = msgb_l2(rmsgb);
+
+	memset(ti, 0x00, n * sizeof(struct osmo_e1dp_line_info));
+
+	/* Fill response */
+	if (n == 1) {
+		_e1d_fill_ts_info(ti, &line->ts[hdr->ts]);
+	} else {
+		for (int i=0; i<32; i++)
+			_e1d_fill_ts_info(ti++, &line->ts[i]);
+	}
+
+	return 0;
+}
+
+static int
+_e1d_ctl_ts_open(void *data, struct msgb *msgb, struct msgb *rmsgb, int *rfd)
+{
+	struct e1_daemon *e1d = (struct e1_daemon *)data;
+	struct osmo_e1dp_msg_hdr *hdr = msgb_l1(msgb);
+	struct osmo_e1dp_ts_config *cfg = msgb_l2(msgb);
+	struct osmo_e1dp_ts_info *ti;
+	struct e1_intf *intf = NULL;
+	struct e1_line *line = NULL;
+	struct e1_ts *ts = NULL;
+	enum e1_ts_mode mode;
+	int ret;
+
+	/* Process query and find timeslot */
+	intf = _e1d_find_intf(e1d, hdr->intf);
+	if (!intf)
+		return 0;
+
+	line = _e1d_find_line(intf, hdr->line);
+	if (!line)
+		return 0;
+
+	ts = _e1d_get_ts(line, hdr->ts);
+	if (!ts)
+		return 0;
+
+	/* Select mode */
+	switch (cfg->mode) {
+	case E1DP_TSMODE_RAW:
+		mode = E1_TS_MODE_RAW;
+		break;
+	case E1DP_TSMODE_HDLCFCS:
+		mode = E1_TS_MODE_HDLCFCS;
+		break;
+	default:
+		return 0;
+	}
+
+	/* If already open, close previous */
+	_e1d_ts_stop(ts);
+
+	/* Init */
+	ret = _e1d_ts_start(ts, mode);
+	if (ret < 0)
+		return ret;
+
+	*rfd = ret;
+
+	/* Allocate response */
+	rmsgb->l2h = msgb_put(rmsgb, sizeof(struct osmo_e1dp_ts_info));
+	ti = msgb_l2(rmsgb);
+
+	memset(ti, 0x00, sizeof(struct osmo_e1dp_line_info));
+
+	/* Fill reponse */
+	ti->id = hdr->ts;
+	ti->cfg.mode = cfg->mode;
+	ti->status = 0xa5;
+
+	return 0;
+}
+
+
+struct osmo_e1dp_server_handler e1d_ctl_handlers[] = {
+	{
+		.type = E1DP_CMD_INTF_QUERY,
+		.flags = E1DP_SF_INTF_OPT,
+		.payload_len = 0,
+		.fn = _e1d_ctl_intf_query,
+	},
+	{
+		.type = E1DP_CMD_LINE_QUERY,
+		.flags = E1DP_SF_INTF_REQ | E1DP_SF_LINE_OPT,
+		.payload_len = 0,
+		.fn = _e1d_ctl_line_query,
+	},
+	{
+		.type = E1DP_CMD_TS_QUERY,
+		.flags = E1DP_SF_INTF_REQ | E1DP_SF_LINE_REQ | E1DP_SF_TS_OPT,
+		.payload_len = 0,
+		.fn = _e1d_ctl_ts_query,
+	},
+	{
+		.type = E1DP_CMD_TS_OPEN,
+		.flags = E1DP_SF_INTF_REQ | E1DP_SF_LINE_REQ | E1DP_SF_TS_REQ,
+		.payload_len = sizeof(struct osmo_e1dp_ts_config),
+		.fn = _e1d_ctl_ts_open,
+	},
+	{ /* guard */ },
+};
diff --git a/src/e1d.h b/src/e1d.h
new file mode 100644
index 0000000..330168b
--- /dev/null
+++ b/src/e1d.h
@@ -0,0 +1,82 @@
+/*
+ * e1d.h
+ *
+ * (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 <stdint.h>
+
+#include <osmocom/core/isdnhdlc.h>
+#include <osmocom/core/linuxlist.h>
+
+
+enum e1_ts_mode {
+	E1_TS_MODE_OFF = 0,
+	E1_TS_MODE_RAW,
+	E1_TS_MODE_HDLCFCS,
+};
+
+struct e1_ts {
+	struct e1_line *line;
+	uint8_t id;
+
+	/* Mode */
+	enum e1_ts_mode mode;
+
+	/* HDLC handling */
+	struct osmo_isdnhdlc_vars hdlc_tx;
+	struct osmo_isdnhdlc_vars hdlc_rx;
+
+	uint8_t rx_buf[264];
+	uint8_t tx_buf[264];
+	int tx_ofs;
+	int tx_len;
+
+	/* Remote end */
+	int fd;
+};
+
+struct e1_line {
+	struct llist_head list;
+
+	struct e1_intf *intf;
+	uint8_t id;
+
+	void *drv_data;
+
+	struct e1_ts ts[32];
+};
+
+struct e1_intf {
+	struct llist_head list;
+
+	struct e1_daemon *e1d;
+	uint8_t id;
+
+	void *drv_data;
+
+	struct llist_head lines;
+};
+
+struct e1_daemon {
+	void *ctx;
+	struct llist_head interfaces;
+};
diff --git a/src/log.c b/src/log.c
new file mode 100644
index 0000000..805d355
--- /dev/null
+++ b/src/log.c
@@ -0,0 +1,41 @@
+/*
+ * log.c
+ *
+ * (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 <osmocom/core/logging.h>
+#include <osmocom/core/utils.h>
+
+#include "log.h"
+
+static const struct log_info_cat default_categories[] = {
+	[DE1D] = {
+		.name = "DE1D",
+		.loglevel = LOGL_DEBUG,
+		.enabled = 1,
+	},
+};
+
+const struct log_info log_info = {
+	.cat = default_categories,
+	.num_cat = ARRAY_SIZE(default_categories),
+};
diff --git a/src/log.h b/src/log.h
new file mode 100644
index 0000000..b3bed47
--- /dev/null
+++ b/src/log.h
@@ -0,0 +1,33 @@
+/*
+ * log.h
+ *
+ * (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.
+ */
+
+#pragma once
+
+#include <osmocom/core/logging.h>
+
+enum {
+	DE1D,
+};
+
+extern const struct log_info log_info;
diff --git a/src/osmo-e1d.c b/src/osmo-e1d.c
new file mode 100644
index 0000000..fa3fc6c
--- /dev/null
+++ b/src/osmo-e1d.c
@@ -0,0 +1,136 @@
+/*
+ * osmo-e1d.c
+ *
+ * (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 <errno.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <talloc.h>
+
+#include <osmocom/core/application.h>
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/select.h>
+
+#include <osmocom/e1d/proto_srv.h>
+
+#include "e1d.h"
+#include "log.h"
+
+
+extern struct osmo_e1dp_server_handler e1d_ctl_handlers[];
+extern int e1_usb_probe(struct e1_daemon *e1d);
+extern int e1_usb_poll(void);
+
+
+
+static void *g_e1d_ctx = NULL;
+static int g_shutdown = 0;
+
+
+static void sig_handler(int signo)
+{
+	fprintf(stdout, "signal %d received\n", signo);
+	switch (signo) {
+	case SIGINT:
+	case SIGTERM:
+		fprintf(stdout, "shutting down\n");
+		g_shutdown = 1;
+		break;
+	case SIGABRT:
+	case SIGUSR1:
+		talloc_report(g_e1d_ctx, stderr);
+		talloc_report_full(g_e1d_ctx, stderr);
+		break;
+	case SIGUSR2:
+		talloc_report_full(g_e1d_ctx, stderr);
+		break;
+	default:
+		break;
+	}
+}
+
+
+int main(int argc, char *argv[])
+{
+	struct e1_daemon *e1d = NULL;
+	struct osmo_e1dp_server *srv = NULL;
+	struct sched_param sp;
+	int rv;
+
+	/* talloc init */
+	g_e1d_ctx = talloc_named_const(NULL, 0, "osmo-e1d");
+	msgb_talloc_ctx_init(g_e1d_ctx, 0);
+
+	/* logging init */
+	osmo_init_logging2(g_e1d_ctx, &log_info);
+
+	/* signals init */
+	signal(SIGINT, &sig_handler);
+	signal(SIGTERM, &sig_handler);
+	signal(SIGABRT, &sig_handler);
+	signal(SIGUSR1, &sig_handler);
+	signal(SIGUSR2, &sig_handler);
+	osmo_init_ignore_signals();
+
+	/* rt prio */
+	memset(&sp, 0x00, sizeof(sp));
+        sp.sched_priority = 50;
+        rv = sched_setscheduler(0, SCHED_RR, &sp);
+	if (rv != 0) {
+		LOGP(DE1D, LOGL_ERROR, "Failed to set Real-Time priority. USB comms might be unstable.\n");
+		perror("sched_setscheduler");
+	}
+
+	/* main state */
+	e1d = talloc_zero(g_e1d_ctx, struct e1_daemon);
+	OSMO_ASSERT(e1d);
+
+	INIT_LLIST_HEAD(&e1d->interfaces);
+
+	/* probe devices */
+	rv = e1_usb_probe(e1d);
+	if (rv != 0) {
+		LOGP(DE1D, LOGL_ERROR, "Failed to prove usb devices\n");
+	}
+
+	/* server init */
+	srv = osmo_e1dp_server_create(g_e1d_ctx, "/tmp/osmo-e1d.ctl", e1d_ctl_handlers, e1d);
+	OSMO_ASSERT(srv);
+
+	/* main loop */
+	while (!g_shutdown) {
+		osmo_select_main(1);
+		e1_usb_poll();
+	}
+
+	/* cleanup */
+	if (srv)
+		osmo_e1dp_server_destroy(srv);
+	
+	talloc_free(e1d);
+
+	return 0;
+}
diff --git a/src/proto.c b/src/proto.c
new file mode 100644
index 0000000..04e533a
--- /dev/null
+++ b/src/proto.c
@@ -0,0 +1,149 @@
+/*
+ * proto.c
+ *
+ * (C) 2019 by Sylvain Munaut <tnt@246tNt.com>
+ *
+ * All Rights Reserved
+ *
+ * SPDX-License-Identifier: LGPL-3.0-or-later
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser 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 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 <string.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+
+#include <osmocom/core/logging.h>
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/select.h>
+#include <osmocom/core/socket.h>
+#include <osmocom/core/utils.h>
+
+#include <osmocom/e1d/proto.h>
+
+#include "log.h"
+
+
+struct msgb *
+osmo_e1dp_recv(struct osmo_fd *ofd, int *fd)
+{
+	struct msgb *msgb;
+	struct osmo_e1dp_msg_hdr *hdr;
+	struct iovec iov;
+	struct msghdr msg;
+	struct cmsghdr *cmsg;
+	char cms[CMSG_SPACE(sizeof(int))];
+	int rc;
+
+	msgb = msgb_alloc(E1DP_MAX_LEN, "e1d proto rx message");
+
+	memset(&msg, 0x00, sizeof(msg));
+
+	iov.iov_base = msgb->data;
+	iov.iov_len = E1DP_MAX_LEN;
+
+	msg.msg_name = 0;
+	msg.msg_namelen = 0;
+	msg.msg_iov = &iov;
+	msg.msg_iovlen = 1;
+	msg.msg_flags = 0;
+	msg.msg_control = (caddr_t) cms;
+	msg.msg_controllen = sizeof(cms);
+
+	rc = recvmsg(ofd->fd, &msg, MSG_WAITALL | MSG_CMSG_CLOEXEC);
+	if (rc == 0)
+		goto err;
+	if (rc < (int)sizeof(struct osmo_e1dp_msg_hdr)) {
+		LOGP(DE1D, LOGL_ERROR, "Failed to read packet header.\n");
+		goto err;
+	}
+
+	msgb->l1h = msgb_put(msgb, sizeof(struct osmo_e1dp_msg_hdr));
+	hdr = msgb_l1(msgb);
+
+	if ((hdr->magic != E1DP_MAGIC) || (hdr->len < sizeof(struct osmo_e1dp_msg_hdr))) {
+		LOGP(DE1D, LOGL_ERROR, "Invalid packet header.\n");
+		goto err;
+	}
+
+	if (hdr->len > sizeof(struct osmo_e1dp_msg_hdr))
+		msgb->l2h = msgb_put(msgb, hdr->len - sizeof(struct osmo_e1dp_msg_hdr));
+	else
+		msgb->l2h = msgb->tail;
+
+	if (fd) {
+		cmsg = CMSG_FIRSTHDR(&msg);
+		if (cmsg) {
+			memmove(fd, CMSG_DATA(cmsg), sizeof(int));
+		} else {
+			*fd = -1;
+		}
+	}
+
+	LOGP(DE1D, LOGL_DEBUG, "rx pkt: %d %s\n", fd ? *fd : -2, msgb_hexdump(msgb));
+
+	return msgb;
+
+err:
+	msgb_free(msgb);
+	return NULL;
+}
+
+int
+osmo_e1dp_send(struct osmo_fd *ofd, struct msgb *msgb, int fd)
+{
+	struct msghdr msg;
+	struct iovec iov;
+	char cmsgbuf[CMSG_SPACE(sizeof(int))];
+	int rc;
+
+	memset(&msg, 0x00, sizeof(msg));
+
+	iov.iov_base = msgb->data;
+	iov.iov_len  = msgb_length(msgb);
+
+	msg.msg_name = NULL;
+	msg.msg_namelen = 0;
+	msg.msg_iov = &iov;
+	msg.msg_iovlen = 1;
+	msg.msg_flags = 0;
+
+	if (fd >= 0) {
+		msg.msg_control = cmsgbuf;
+		msg.msg_controllen = CMSG_LEN(sizeof(int));
+
+		struct cmsghdr* cmsg = CMSG_FIRSTHDR(&msg);
+		cmsg->cmsg_level = SOL_SOCKET;
+		cmsg->cmsg_type = SCM_RIGHTS;
+		cmsg->cmsg_len = CMSG_LEN(sizeof(int));
+
+		*(int*) CMSG_DATA(cmsg) = fd;
+	}
+
+	rc = sendmsg(ofd->fd, &msg, 0);
+	if (rc < 0) {
+		LOGP(DE1D, LOGL_ERROR, "Failed to send packet.\n");
+		perror("tx");
+	}
+
+	if (fd >= 0)
+		close(fd);
+
+	LOGP(DE1D, LOGL_DEBUG, "tx pkt: %d %s\n", msgb_length(msgb), msgb_hexdump(msgb));
+
+	return rc;
+}
diff --git a/src/proto_clnt.c b/src/proto_clnt.c
new file mode 100644
index 0000000..f378f5b
--- /dev/null
+++ b/src/proto_clnt.c
@@ -0,0 +1,319 @@
+/*
+ * proto_clnt.c
+ *
+ * (C) 2019 by Sylvain Munaut <tnt@246tNt.com>
+ *
+ * All Rights Reserved
+ *
+ * SPDX-License-Identifier: LGPL-3.0-or-later
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser 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 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 <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+
+#include <talloc.h>
+
+#include <osmocom/core/linuxlist.h>
+#include <osmocom/core/logging.h>
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/select.h>
+#include <osmocom/core/socket.h>
+#include <osmocom/core/utils.h>
+
+#include <osmocom/e1d/proto.h>
+#include <osmocom/e1d/proto_clnt.h>
+
+#include "log.h"
+
+
+struct osmo_e1dp_client {
+	void *ctx;
+	struct osmo_fd ctl_fd;
+};
+
+
+static int
+_e1dp_client_event(struct osmo_e1dp_client *clnt, struct msgb *msgb)
+{
+	/* FIXME */
+	return 0;
+}
+
+
+static int
+_e1dp_client_read(struct osmo_fd *ofd, unsigned int flags)
+{
+	struct osmo_e1dp_client *clnt = ofd->data;
+	struct msgb *msgb;
+	struct osmo_e1dp_msg_hdr *hdr;
+
+	msgb = osmo_e1dp_recv(ofd, NULL);
+	if (!msgb)
+		goto err;
+
+	hdr = msgb_l1(msgb);
+	if ((hdr->type & E1DP_TYPE_MSK) != E1DP_EVT_TYPE)
+		goto err;
+
+	_e1dp_client_event(clnt, msgb);
+
+	msgb_free(msgb);
+
+	return 0;
+
+err:
+	msgb_free(msgb);
+
+	return -1;
+}
+
+
+struct osmo_e1dp_client *
+osmo_e1dp_client_create(void *ctx, const char *path)
+{
+	struct osmo_e1dp_client *clnt;
+	int rc;
+
+	/* Base structure init */
+	clnt = talloc_zero(ctx, struct osmo_e1dp_client);
+	OSMO_ASSERT(clnt);
+
+	clnt->ctx = ctx;
+
+	/* Client socket */
+	rc = osmo_sock_unix_init_ofd(&clnt->ctl_fd, SOCK_SEQPACKET, 0, path, OSMO_SOCK_F_CONNECT);
+	if (rc < 0)
+		goto err;
+
+	clnt->ctl_fd.cb = _e1dp_client_read;
+	clnt->ctl_fd.data = clnt;
+
+	return clnt;
+
+err:
+	talloc_free(clnt);
+	return NULL;
+}
+
+
+void
+osmo_e1dp_client_destroy(struct osmo_e1dp_client *clnt)
+{
+	if (!clnt)
+		return;
+
+	osmo_fd_close(&clnt->ctl_fd);
+	talloc_free(clnt);
+}
+
+
+static int
+_e1dp_client_query_base(struct osmo_e1dp_client *clnt,
+	struct osmo_e1dp_msg_hdr *hdr, void *payload, int payload_len,
+	struct msgb **resp, int *rfd)
+{
+	struct msgb *msgb;
+	struct osmo_e1dp_msg_hdr *msg_hdr;
+	int rc, fd;
+
+	/* Request */
+	msgb = msgb_alloc(E1DP_MAX_LEN, "e1dp client request");
+	OSMO_ASSERT(msgb);
+
+	msg_hdr = (struct osmo_e1dp_msg_hdr *)msgb_put(msgb, sizeof(struct osmo_e1dp_msg_hdr));
+	memcpy(msg_hdr, hdr, sizeof(struct osmo_e1dp_msg_hdr));
+
+	msg_hdr->magic = E1DP_MAGIC;
+	msg_hdr->len   = sizeof(struct osmo_e1dp_msg_hdr) + payload_len;
+
+	if (payload_len) {
+		msgb->l2h = msgb_put(msgb, payload_len);
+		memcpy(msgb_l2(msgb), payload, payload_len);
+	}
+
+	rc = osmo_e1dp_send(&clnt->ctl_fd, msgb, -1);
+	if (rc < 0)
+		return rc;
+
+	msgb_free(msgb);
+
+	/* Response */
+	int flags = fcntl(clnt->ctl_fd.fd, F_GETFL, 0);
+	fcntl(clnt->ctl_fd.fd, F_SETFL, flags & ~O_NONBLOCK);
+
+	while (1) {
+		fd = -1;
+		msgb = osmo_e1dp_recv(&clnt->ctl_fd, &fd);
+		if (!msgb) {
+			rc = -EPIPE;
+			goto err;
+		}
+
+		msg_hdr = msgb_l1(msgb);
+		if ((msg_hdr->type & E1DP_TYPE_MSK) != E1DP_EVT_TYPE)
+			break;
+
+		_e1dp_client_event(clnt, msgb);
+		msgb_free(msgb);
+	}
+
+	fcntl(clnt->ctl_fd.fd, F_SETFL, flags);
+
+	if (msg_hdr->type != (hdr->type | E1DP_RESP_TYPE)) {
+		rc = -EPIPE;
+		goto err;
+	}
+
+	*resp = msgb;
+	if (rfd)
+		*rfd = fd;
+
+	return 0;
+err:
+	fcntl(clnt->ctl_fd.fd, F_SETFL, flags);
+	msgb_free(msgb);
+	return rc;
+}
+
+int
+osmo_e1dp_client_intf_query(struct osmo_e1dp_client *clnt,
+	struct osmo_e1dp_intf_info **ii, int *n,
+	uint8_t intf)
+{
+	struct msgb *msgb;
+	struct osmo_e1dp_msg_hdr hdr;
+	int rc;
+
+	memset(&hdr, 0x00, sizeof(struct osmo_e1dp_msg_hdr));
+	hdr.type = E1DP_CMD_INTF_QUERY;
+	hdr.intf = intf;
+	hdr.line = E1DP_INVALID;
+	hdr.ts   = E1DP_INVALID;
+
+	rc = _e1dp_client_query_base(clnt, &hdr, NULL, 0, &msgb, NULL);
+	if (rc)
+		return rc;
+
+	*n  = msgb_l2len(msgb) / sizeof(struct osmo_e1dp_intf_info);
+
+	if (*n) {
+		*ii = talloc_array(clnt->ctx, struct osmo_e1dp_intf_info, *n);
+		memcpy(*ii, msgb_l2(msgb), *n * sizeof(struct osmo_e1dp_intf_info));
+	}
+
+	msgb_free(msgb);
+
+	return 0;
+}
+
+int
+osmo_e1dp_client_line_query(struct osmo_e1dp_client *clnt,
+	struct osmo_e1dp_line_info **li, int *n,
+	uint8_t intf, uint8_t line)
+{
+	struct msgb *msgb;
+	struct osmo_e1dp_msg_hdr hdr;
+	int rc;
+
+	memset(&hdr, 0x00, sizeof(struct osmo_e1dp_msg_hdr));
+	hdr.type = E1DP_CMD_LINE_QUERY;
+	hdr.intf = intf;
+	hdr.line = line;
+	hdr.ts   = E1DP_INVALID;
+
+	rc = _e1dp_client_query_base(clnt, &hdr, NULL, 0, &msgb, NULL);
+	if (rc)
+		return rc;
+
+	*n  = msgb_l2len(msgb) / sizeof(struct osmo_e1dp_line_info);
+
+	if (*n) {
+		*li = talloc_array(clnt->ctx, struct osmo_e1dp_line_info, *n);
+		memcpy(*li, msgb_l2(msgb), *n * sizeof(struct osmo_e1dp_line_info));
+	}
+
+	msgb_free(msgb);
+
+	return 0;
+}
+
+int
+osmo_e1dp_client_ts_query(struct osmo_e1dp_client *clnt,
+	struct osmo_e1dp_ts_info **ti, int *n,
+	uint8_t intf, uint8_t line, uint8_t ts)
+{
+	struct msgb *msgb;
+	struct osmo_e1dp_msg_hdr hdr;
+	int rc;
+
+	memset(&hdr, 0x00, sizeof(struct osmo_e1dp_msg_hdr));
+	hdr.type = E1DP_CMD_TS_QUERY;
+	hdr.intf = intf;
+	hdr.line = line;
+	hdr.ts   = ts;
+
+	rc = _e1dp_client_query_base(clnt, &hdr, NULL, 0, &msgb, NULL);
+	if (rc)
+		return rc;
+
+	*n  = msgb_l2len(msgb) / sizeof(struct osmo_e1dp_ts_info);
+
+	if (*n) {
+		*ti = talloc_array(clnt->ctx, struct osmo_e1dp_ts_info, *n);
+		memcpy(*ti, msgb_l2(msgb), *n * sizeof(struct osmo_e1dp_ts_info));
+	}
+
+	msgb_free(msgb);
+
+	return 0;
+}
+
+int
+osmo_e1dp_client_ts_open(struct osmo_e1dp_client *clnt,
+	uint8_t intf, uint8_t line, uint8_t ts,
+	enum osmo_e1dp_ts_mode mode)
+{
+	struct msgb *msgb;
+	struct osmo_e1dp_msg_hdr hdr;
+	struct osmo_e1dp_ts_config cfg;
+	int rc, tsfd;
+
+	memset(&hdr, 0x00, sizeof(struct osmo_e1dp_msg_hdr));
+	hdr.type = E1DP_CMD_TS_OPEN;
+	hdr.intf = intf;
+	hdr.line = line;
+	hdr.ts   = ts;
+
+	memset(&cfg, 0x00, sizeof(struct osmo_e1dp_ts_config));
+	cfg.mode = mode;
+
+	tsfd = -1;
+
+	rc = _e1dp_client_query_base(clnt, &hdr, &cfg, sizeof(struct osmo_e1dp_ts_config), &msgb, &tsfd);
+	if (rc)
+		return rc;
+
+	if ((tsfd < 0) || (msgb_l2len(msgb) != sizeof(struct osmo_e1dp_ts_info)))
+		return -EPIPE;
+
+	msgb_free(msgb);
+
+	return tsfd;
+}
diff --git a/src/proto_srv.c b/src/proto_srv.c
new file mode 100644
index 0000000..c74e043
--- /dev/null
+++ b/src/proto_srv.c
@@ -0,0 +1,260 @@
+/*
+ * proto_srv.c
+ *
+ * (C) 2019 by Sylvain Munaut <tnt@246tNt.com>
+ *
+ * All Rights Reserved
+ *
+ * SPDX-License-Identifier: LGPL-3.0-or-later
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser 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 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 <errno.h>
+#include <unistd.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+
+#include <talloc.h>
+
+#include <osmocom/core/linuxlist.h>
+#include <osmocom/core/logging.h>
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/select.h>
+#include <osmocom/core/socket.h>
+#include <osmocom/core/utils.h>
+
+#include <osmocom/e1d/proto.h>
+#include <osmocom/e1d/proto_srv.h>
+
+#include "log.h"
+
+
+struct osmo_e1dp_server {
+	void *ctx;
+	struct osmo_fd ctl_fd;
+	struct llist_head conns;
+	struct osmo_e1dp_server_handler *handlers;
+	void *handler_data;
+};
+
+struct osmo_e1dp_server_conn {
+	struct llist_head list;
+	struct osmo_e1dp_server *srv;
+	struct osmo_fd fd;
+};
+
+
+static int
+_e1dp_server_request(struct osmo_e1dp_server_conn *conn, struct msgb *msgb)
+{
+	struct osmo_e1dp_msg_hdr *hdr = msgb_l1(msgb);
+	struct osmo_e1dp_msg_hdr *rhdr;
+	struct osmo_e1dp_server_handler *h;
+	struct msgb *rmsgb;
+	int rfd, rc;
+
+	/* Find handler */
+	h = conn->srv->handlers;
+
+	while (h->fn) {
+		if (h->type == hdr->type)
+			break;
+		h++;
+	}
+
+	if (!h->fn) {
+		LOGP(DE1D, LOGL_ERROR, "Unhandled message type: %d.\n", hdr->type);
+		return -1;
+	}
+
+	/* Check flags */
+	if (((hdr->intf == E1DP_INVALID) ?
+		(h->flags & E1DP_SF_INTF_REQ) : !(h->flags & (E1DP_SF_INTF_OPT | E1DP_SF_INTF_REQ))) ||
+	    ((hdr->line == E1DP_INVALID) ?
+		(h->flags & E1DP_SF_LINE_REQ) : !(h->flags & (E1DP_SF_LINE_OPT | E1DP_SF_LINE_REQ))) ||
+	    ((hdr->ts == E1DP_INVALID) ?
+		(h->flags & E1DP_SF_TS_REQ)   : !(h->flags & (E1DP_SF_TS_OPT   | E1DP_SF_TS_REQ))))
+	{
+		LOGP(DE1D, LOGL_ERROR, "Invalid type/intf/line for message type: %d / (%d/%d/%d) %d.\n",
+			hdr->type, hdr->intf, hdr->line, hdr->ts, h->flags);
+		return -1;
+	}
+
+	/* Check payload length */
+	if ((h->payload_len >= 0) &&
+	    (h->payload_len != (msgb_length(msgb) - sizeof(struct osmo_e1dp_msg_hdr))))
+	{
+		LOGP(DE1D, LOGL_ERROR, "Invalid payload for message type: %d / (%d/%d/%d).\n",
+			hdr->type, hdr->intf, hdr->line, hdr->ts);
+		return -1;
+	}
+
+	/* Call handler */
+	rmsgb = msgb_alloc(E1DP_MAX_LEN, "e1d proto tx message");
+	rfd = -1;
+
+	rmsgb->l1h = msgb_put(rmsgb, sizeof(struct osmo_e1dp_msg_hdr));
+	rhdr = msgb_l1(rmsgb);
+
+	rc = h->fn(conn->srv->handler_data, msgb, rmsgb, &rfd);
+
+	if (rc) {
+		msgb_trim(rmsgb, msgb_l1len(rmsgb));
+		rhdr->type = E1DP_ERR_TYPE | (rc & 0x3f);
+	} else {
+		rhdr->type =  hdr->type | E1DP_RESP_TYPE;
+	}
+
+	rhdr->magic = E1DP_MAGIC;
+	rhdr->len = msgb_length(rmsgb);
+
+	/* Send response */
+	rc = osmo_e1dp_send(&conn->fd, rmsgb, rfd);
+	rc = (rc <= 0) ? -EPIPE : 0;
+
+	/* Done */
+	msgb_free(rmsgb);
+
+	return rc;
+}
+
+static void
+_e1dp_server_disconnect(struct osmo_e1dp_server_conn *conn)
+{
+	osmo_fd_close(&conn->fd);
+	llist_del(&conn->list);
+	talloc_free(conn);
+}
+
+static int
+_e1dp_server_read(struct osmo_fd *fd, unsigned int flags)
+{
+	struct osmo_e1dp_server_conn *conn = fd->data;
+	struct msgb *msgb;
+	int rc;
+
+	msgb = osmo_e1dp_recv(fd, NULL);
+	if (!msgb)
+		goto err;
+
+	rc = _e1dp_server_request(conn, msgb);
+	if (rc)
+		goto err;
+
+	msgb_free(msgb);
+
+	return 0;
+
+err:
+	/* Disconnect client */
+	msgb_free(msgb);
+	_e1dp_server_disconnect(conn);
+
+	return -1;
+}
+
+
+static int
+_e1dp_server_accept(struct osmo_fd *fd, unsigned int flags)
+{
+	struct osmo_e1dp_server *srv = fd->data;
+	struct osmo_e1dp_server_conn *conn;
+	struct sockaddr_un un_addr;
+	socklen_t len;
+	int rc;
+
+	len = sizeof(un_addr);
+	rc = accept(fd->fd, (struct sockaddr *) &un_addr, &len);
+	if (rc < 0) {
+		LOGP(DE1D, LOGL_ERROR, "Failed to accept a new connection.\n");
+		return -1;
+	}
+
+	conn = talloc_zero(srv->ctx, struct osmo_e1dp_server_conn);
+	if (!conn) {
+		LOGP(DE1D, LOGL_ERROR, "Failed to create incoming connection.\n");
+		return -1;
+	}
+
+	conn->srv = srv;
+
+	conn->fd.fd = rc;
+	conn->fd.when = BSC_FD_READ;
+	conn->fd.cb = _e1dp_server_read;
+	conn->fd.data = conn;
+
+	if (osmo_fd_register(&conn->fd) != 0) {
+		LOGP(DE1D, LOGL_ERROR, "Failed to register incoming fd.\n");
+		return -1;
+	}
+
+	llist_add(&conn->list, &srv->conns);
+
+	LOGP(DE1D, LOGL_DEBUG, "New incoming connection.\n");
+
+	return 0;
+}
+
+
+struct osmo_e1dp_server *
+osmo_e1dp_server_create(void *ctx, const char *path,
+                        struct osmo_e1dp_server_handler *handlers, void *handler_data)
+{
+	struct osmo_e1dp_server *srv;
+	int rc;
+
+	/* Base structure init */
+	srv = talloc_zero(ctx, struct osmo_e1dp_server);
+	OSMO_ASSERT(srv);
+
+	srv->ctx = ctx;
+	srv->handlers = handlers;
+	srv->handler_data = handler_data;
+
+	INIT_LLIST_HEAD(&srv->conns);
+
+	/* Server socket */
+	rc = osmo_sock_unix_init_ofd(&srv->ctl_fd, SOCK_SEQPACKET, 0, path, OSMO_SOCK_F_BIND);
+	if (rc < 0)
+		goto err;
+
+	srv->ctl_fd.cb = _e1dp_server_accept;
+	srv->ctl_fd.data = srv;
+
+	return srv;
+
+err:
+	talloc_free(srv);
+	return NULL;
+}
+
+void
+osmo_e1dp_server_destroy(struct osmo_e1dp_server *srv)
+{
+	struct osmo_e1dp_server_conn *conn, *tmp;
+
+	if (!srv)
+		return;
+
+	/* Disconnect all clients */
+	llist_for_each_entry_safe(conn, tmp, &srv->conns, list) {
+		_e1dp_server_disconnect(conn);
+	}
+
+	/* Resource release */
+	osmo_fd_close(&srv->ctl_fd);
+	talloc_free(srv);
+}
diff --git a/src/usb.c b/src/usb.c
new file mode 100644
index 0000000..4968e41
--- /dev/null
+++ b/src/usb.c
@@ -0,0 +1,616 @@
+/*
+ * usb.c
+ *
+ * (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 <errno.h>
+#include <unistd.h>
+#include <stdint.h>
+#include <string.h>
+#include <talloc.h>
+
+#include <osmocom/core/isdnhdlc.h>
+#include <osmocom/core/utils.h>
+
+#include <libusb.h>
+
+#include "e1d.h"
+#include "log.h"
+
+
+#define USB_VID		0x1d50
+#define USB_PID		0xe1e1
+
+libusb_context *g_usb = NULL;
+
+
+struct e1_usb_flow;
+
+
+/* Driver data */
+
+struct e1_usb_line_data {
+	/* Interface */
+	uint8_t if_num;
+
+	/* End Points */
+	uint8_t ep_in;
+	uint8_t ep_out;
+	uint8_t ep_fb;
+
+	/* Max packet size */
+	int pkt_size;
+
+	/* Flow */
+	struct e1_usb_flow *flow_in;
+	struct e1_usb_flow *flow_out;
+	struct e1_usb_flow *flow_fb;
+
+	/* Rate regulation */
+	uint32_t r_acc;
+	uint32_t r_sw;
+};
+
+struct e1_usb_intf_data {
+	libusb_device_handle *devh;
+};
+
+
+/* Flow */
+
+struct e1_usb_flow_entry {
+	uint8_t *buf;
+	struct libusb_transfer *xfr;
+};
+
+typedef int (*xfer_cb_t)(struct e1_usb_flow *flow, uint8_t *buf, int size);
+
+struct e1_usb_flow {
+	struct e1_line *line;
+	xfer_cb_t cb;
+
+	uint8_t ep;
+
+	int count;
+	int size;
+	int ppx;
+
+	struct e1_usb_flow_entry *entries;
+};
+
+
+
+// ---------------------------------------------------------------------------
+// USB data transfer
+// ---------------------------------------------------------------------------
+
+static int
+_e1_rx_hdlcfs(struct e1_ts *ts, uint8_t *buf, int len)
+{
+	int rv, cl, oi;
+
+	oi = 0;
+
+	while (oi < len) {
+		rv = osmo_isdnhdlc_decode(&ts->hdlc_rx,
+			&buf[oi], len-oi, &cl,
+			ts->rx_buf, sizeof(ts->rx_buf)
+		);
+
+		if (rv > 0) {
+			printf("RX Message: %d %d [ %s]\n", ts->id, rv, osmo_hexdump(ts->rx_buf, rv));
+			write(ts->fd, ts->rx_buf, rv);
+		} else  if (rv < 0 && ts->id == 4) {
+			printf("ERR RX: %d %d %d [ %s]\n",rv,oi,cl, osmo_hexdump(buf, len));
+		}
+
+		oi += cl;
+	}
+
+	return 0;
+}
+
+static int
+_e1_tx_hdlcfs(struct e1_ts *ts, uint8_t *buf, int len)
+{
+	int rv, oo, cl;
+
+	oo = 0;
+
+	while (oo < len) {
+		/* Pending message ? */
+		if (!ts->tx_len) {
+			rv = read(ts->fd, ts->tx_buf, sizeof(ts->tx_buf));
+			if (rv > 0) {
+				printf("TX Message: %d %d [ %s]\n", ts->id, rv, osmo_hexdump(ts->tx_buf, rv));
+				ts->tx_len = rv; 
+				ts->tx_ofs = 0;
+			}
+		}
+
+		/* */
+		rv = osmo_isdnhdlc_encode(&ts->hdlc_tx,
+			&ts->tx_buf[ts->tx_ofs], ts->tx_len - ts->tx_ofs, &cl,
+			&buf[oo], len - oo
+		);
+
+		if (rv < 0)
+			printf("ERR TX: %d\n", rv);
+
+		if (ts->tx_ofs < ts->tx_len)
+			printf("TX chunk %d/%d %d [ %s]\n", ts->tx_ofs, ts->tx_len, cl, osmo_hexdump(&buf[ts->tx_ofs], rv));
+
+		if (rv > 0)
+			oo += rv;
+
+		ts->tx_ofs += cl;
+		if (ts->tx_ofs >= ts->tx_len) {
+			ts->tx_len = 0;
+			ts->tx_ofs = 0;
+		}
+	}
+
+	return len;
+}
+
+static int
+e1_usb_xfer_in(struct e1_usb_flow *flow, uint8_t *buf, int size)
+{
+	struct e1_line *line = flow->line;
+	int ftr;
+
+	if (size <= 0) {
+		printf("IN ERROR: %d\n", size);
+		return -1;
+	}
+
+	ftr = (size - 4) / 32;
+
+	for (int tsn=1; tsn<32; tsn++)
+	{
+		struct e1_ts *ts = &line->ts[tsn];
+		uint8_t buf_ts[32];
+
+		if (ts->mode == E1_TS_MODE_OFF)
+			continue;
+
+		for (int i=0; i<ftr; i++)
+			buf_ts[i] = buf[4+tsn+(i*32)];
+
+		switch (ts->mode) {
+		case E1_TS_MODE_RAW:
+			write(ts->fd, buf_ts, ftr);
+			break;
+		case E1_TS_MODE_HDLCFCS:
+			_e1_rx_hdlcfs(ts, buf_ts, ftr);
+			break;
+		default:
+			continue;
+		}
+	}
+
+	return 0;
+}
+
+static int
+e1_usb_xfer_out(struct e1_usb_flow *flow, uint8_t *buf, int size)
+{
+	struct e1_line *line = flow->line;
+	struct e1_usb_line_data *ld = (struct e1_usb_line_data *) line->drv_data;
+	int fts, tsz;
+
+	if (size <= 0) {
+		printf("OUT ERROR: %d\n", size);
+		return -1;
+	}
+
+	/* Flow regulation */
+	ld->r_acc += ld->r_sw;
+
+	fts = ld->r_acc >> 10;
+	if      (fts <  4) fts = 4;
+	else if (fts > 12) fts = 12;
+
+	ld->r_acc -= fts << 10;
+	if (ld->r_acc & 0x80000000)
+		ld->r_acc = 0;
+
+	/* Prepare */
+	tsz = 4 + 32 * fts;
+	memset(buf, 0xff, tsz);
+
+	/* Header */
+		/* FIXME */
+
+	/* Scan timeslots */
+	for (int tsn=1; tsn<32; tsn++)
+	{
+		struct e1_ts *ts = &line->ts[tsn];
+		uint8_t buf_ts[32];
+		int l;
+
+		if (ts->mode == E1_TS_MODE_OFF)
+			continue;
+
+		switch (ts->mode) {
+		case E1_TS_MODE_RAW:
+			l = read(ts->fd, buf_ts, fts);
+			break;
+		case E1_TS_MODE_HDLCFCS:
+			l = _e1_tx_hdlcfs(ts, buf_ts, fts);
+			break;
+		default:
+			continue;
+		}
+
+		if (l <= 0)
+			continue;
+
+		for (int i=0; i<l; i++)
+			buf[4+tsn+(i*32)] = buf_ts[i];
+	}
+
+	return tsz;
+}
+
+static int
+e1_usb_xfer_fb(struct e1_usb_flow *flow, uint8_t *buf, int size)
+{
+	struct e1_usb_line_data *ld = (struct e1_usb_line_data *) flow->line->drv_data;
+
+	if (size < 0) {
+		LOGP(DE1D, LOGL_ERROR, "Feedback transfer error\n");
+		return 0;
+	} else if (size != 3) {
+		LOGP(DE1D, LOGL_ERROR, "Feedback packet invalid size (%d)\n", size);
+		return 0;
+	}
+
+	ld->r_sw = (buf[2] << 16) | (buf[1] << 8) | buf[0];
+
+	return 0;
+}
+
+
+// ---------------------------------------------------------------------------
+// USB flow
+// ---------------------------------------------------------------------------
+
+static void LIBUSB_CALL
+_e1uf_xfr(struct libusb_transfer *xfr)
+{
+	struct e1_usb_flow *flow = (struct e1_usb_flow *) xfr->user_data;
+	struct e1_usb_intf_data *id = (struct e1_usb_intf_data *) flow->line->intf->drv_data;
+	int j, rv, len;
+
+	len = 0;
+
+	/* FIXME: Check transfer status ? Error handling ? */
+
+	if (flow->ep & 0x80) {
+		for (j=0; j<flow->ppx; j++) {
+			flow->cb(flow,
+				libusb_get_iso_packet_buffer_simple(xfr, j),
+				(xfr->iso_packet_desc[j].status == LIBUSB_TRANSFER_COMPLETED) ?
+					xfr->iso_packet_desc[j].actual_length : -1
+			);
+			len += (xfr->iso_packet_desc[j].length = flow->size);
+		}
+	} else {
+		for (j=0; j<flow->ppx; j++)
+			len += (xfr->iso_packet_desc[j].length = flow->cb(flow, &xfr->buffer[len], flow->size));
+	}
+
+	libusb_fill_iso_transfer(xfr, id->devh, flow->ep,
+		xfr->buffer, len, flow->ppx,
+		_e1uf_xfr, flow, 0
+	);
+
+	rv = libusb_submit_transfer(xfr);
+	if (rv)
+		LOGP(DE1D, LOGL_ERROR, "Failed to resubmit buffer for transfer\n");
+}
+
+static struct e1_usb_flow *
+e1uf_create(struct e1_line *line, xfer_cb_t cb,
+            int ep, int count, int size, int ppx)
+{
+	void *ctx = line->intf->e1d->ctx;
+	struct e1_usb_flow *flow;
+
+	flow = talloc_zero(ctx, struct e1_usb_flow);
+	OSMO_ASSERT(flow);
+
+	flow->line  = line;
+	flow->cb    = cb;
+	flow->ep    = ep;
+	flow->count = count;
+	flow->size  = size;
+	flow->ppx   = ppx;
+	flow->entries = talloc_zero_size(ctx, count * sizeof(struct e1_usb_flow_entry));
+
+	for (int i=0; i<count; i++)
+		flow->entries[i].buf = talloc_zero_size(ctx, size * ppx);
+
+	return flow;
+}
+
+static void
+e1uf_destroy(struct e1_usb_flow *flow)
+{
+	if (!flow)
+		return;
+
+	/* FIXME: stop pending transfers */
+	for (int i=0; i<flow->count; i++)
+		talloc_free(flow->entries[i].buf);
+
+	talloc_free(flow->entries);
+	talloc_free(flow);
+}
+
+static int
+e1uf_start(struct e1_usb_flow *flow)
+{
+	struct e1_usb_intf_data *id = (struct e1_usb_intf_data *) flow->line->intf->drv_data;
+	struct libusb_transfer *xfr;
+	int i, j, rv, len;
+
+	for (i=0; i<flow->count; i++)
+	{
+		xfr = libusb_alloc_transfer(flow->ppx);
+		if (!xfr)
+			return -ENOMEM;
+
+		len = 0;
+
+		if (flow->ep & 0x80) {
+			for (j=0; j<flow->ppx; j++)
+				len += (xfr->iso_packet_desc[j].length = flow->size);
+		} else {
+			for (j=0; j<flow->ppx; j++)
+				len += (xfr->iso_packet_desc[j].length = flow->cb(flow, &flow->entries[i].buf[len], flow->size));
+		}
+
+		libusb_fill_iso_transfer(xfr, id->devh, flow->ep,
+			flow->entries[i].buf, len, flow->ppx,
+			_e1uf_xfr, flow, 0
+		);
+
+		rv = libusb_submit_transfer(xfr);
+
+		if (rv)
+			return rv;
+
+		flow->entries[i].xfr = xfr;
+	}
+
+	return 0;
+}
+
+
+// ---------------------------------------------------------------------------
+// e1d structures
+// ---------------------------------------------------------------------------
+
+struct e1_intf *
+_e1_intf_new(struct e1_daemon *e1d, void *drv_data)
+{
+	struct e1_intf *intf;
+
+	intf = talloc_zero(e1d->ctx, struct e1_intf);
+	OSMO_ASSERT(intf);
+
+	intf->e1d = e1d;
+	intf->drv_data = drv_data;
+
+	INIT_LLIST_HEAD(&intf->list);
+	INIT_LLIST_HEAD(&intf->lines);
+
+	if (!llist_empty(&e1d->interfaces)) {
+		struct e1_intf *f = llist_first_entry(&e1d->interfaces, struct e1_intf, list);
+		intf->id = f->id + 1;
+	}
+
+	llist_add(&intf->list, &e1d->interfaces);
+
+	return intf;
+}
+
+struct e1_line *
+_e1_line_new(struct e1_intf *intf, void *drv_data)
+{
+	struct e1_line *line;
+
+	line = talloc_zero(intf->e1d->ctx, struct e1_line);
+	OSMO_ASSERT(line);
+
+	line->intf = intf;
+	line->drv_data = drv_data;
+
+	for (int i=0; i<32; i++)
+		line->ts[i].id = i;
+
+	INIT_LLIST_HEAD(&line->list);
+
+	if (!llist_empty(&intf->lines)) {
+		struct e1_line *l = llist_first_entry(&intf->lines, struct e1_line, list);
+		line->id = l->id + 1;
+	}
+
+	llist_add(&line->list, &intf->lines);
+
+	return line;
+}
+
+
+
+// ---------------------------------------------------------------------------
+// Init / Probing
+// ---------------------------------------------------------------------------
+
+int
+_e1_usb_open_device(struct e1_daemon *e1d, struct libusb_device *dev)
+{
+	struct e1_intf *intf;
+	struct e1_line *line;
+	struct e1_usb_intf_data *intf_data;
+	struct e1_usb_line_data *line_data;
+	struct libusb_config_descriptor *cd;
+	const struct libusb_interface_descriptor *id;
+	libusb_device_handle *devh;
+	int i, j, ret;
+
+	ret = libusb_open(dev, &devh);
+	if (ret) {
+		LOGP(DE1D, LOGL_ERROR, "Failed to open usb device\n");
+		return ret;
+	}
+
+	intf_data = talloc_zero(e1d->ctx, struct e1_usb_intf_data);
+	intf_data->devh = devh;
+
+	intf = _e1_intf_new(e1d, intf_data);
+
+	ret = libusb_get_active_config_descriptor(dev, &cd);
+	if (ret) {
+		LOGP(DE1D, LOGL_ERROR, "Failed to talk to usb device\n");
+		return ret;
+	}
+
+	for (i=0; i<cd->bNumInterfaces; i++) {
+		/* Expect 2 altsettings with proper class/subclass/eps */
+		if (cd->interface[i].num_altsetting != 2)
+			continue;
+
+		id = &cd->interface[i].altsetting[1];
+		if ((id->bInterfaceClass != 0xff) || (id->bInterfaceSubClass != 0xe1) || (id->bNumEndpoints != 3))
+			continue;
+
+		/* Get interface and set it up */
+		ret = libusb_claim_interface(devh, id->bInterfaceNumber);
+		if (ret) {
+			LOGP(DE1D, LOGL_ERROR, "Failed to claim interface %d\n", id->bInterfaceNumber);
+			return ret;
+		}
+
+		ret = libusb_set_interface_alt_setting(devh, id->bInterfaceNumber, 1);
+		if (ret) {
+			LOGP(DE1D, LOGL_ERROR, "Failed to set interface %d altsetting\n", id->bInterfaceNumber);
+			return ret;
+		}
+
+		/* Setup driver data and find endpoints */
+		line_data = talloc_zero(e1d->ctx, struct e1_usb_line_data);
+
+		line_data->if_num = id->bInterfaceNumber;
+		line_data->r_acc  = 0;
+		line_data->r_sw   = 8192;
+
+		for (j=0; j<id->bNumEndpoints; j++) {
+			if (id->endpoint[j].bmAttributes == 0x11) {
+				line_data->ep_fb = id->endpoint[j].bEndpointAddress;
+			} else if (id->endpoint[j].bmAttributes == 0x05) {
+				if (id->endpoint[j].bEndpointAddress & 0x80)
+					line_data->ep_in = id->endpoint[j].bEndpointAddress;
+				else
+					line_data->ep_out = id->endpoint[j].bEndpointAddress;
+
+				if (!line_data->pkt_size)
+					line_data->pkt_size = id->endpoint[j].wMaxPacketSize;
+				else if (line_data->pkt_size != id->endpoint[j].wMaxPacketSize)
+					LOGP(DE1D, LOGL_ERROR, "Inconsistent max packet size %d vs %d\n",
+						line_data->pkt_size, (int)id->endpoint[j].wMaxPacketSize);
+			} else {
+				LOGP(DE1D, LOGL_ERROR, "Invalid EP %02x\n", id->endpoint[j].bEndpointAddress);
+			}
+		}
+
+		if (!line_data->ep_in || !line_data->ep_out || !line_data->ep_fb || !line_data->pkt_size) {
+			LOGP(DE1D, LOGL_ERROR, "Failed to use interface %d\n", id->bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		line = _e1_line_new(intf, line_data);
+
+		line_data->flow_in  = e1uf_create(line, e1_usb_xfer_in,  line_data->ep_in,  2, line_data->pkt_size, 4);
+		line_data->flow_out = e1uf_create(line, e1_usb_xfer_out, line_data->ep_out, 2, line_data->pkt_size, 4);
+		line_data->flow_fb  = e1uf_create(line, e1_usb_xfer_fb,  line_data->ep_fb,  2, 8, 1);
+
+		e1uf_start(line_data->flow_in);
+		e1uf_start(line_data->flow_out);
+		e1uf_start(line_data->flow_fb);
+	}
+
+	return 0;
+}
+
+int
+e1_usb_probe(struct e1_daemon *e1d)
+{
+	struct libusb_device **dev_list;
+	ssize_t n_dev;
+	int i, ret;
+
+	if (!g_usb) {
+		ret = libusb_init(&g_usb);
+		if (ret) {
+			LOGP(DE1D, LOGL_ERROR, "Failed to initialize libusb\n");
+			return -EIO;
+		}
+	}
+
+	n_dev = libusb_get_device_list(g_usb, &dev_list);
+	if (n_dev < 0) {
+		LOGP(DE1D, LOGL_ERROR, "Failed to list devices\n");
+		return -EIO;
+	}
+
+	for (i=0; i<n_dev; i++) {
+		struct libusb_device_descriptor desc;
+
+		ret = libusb_get_device_descriptor(dev_list[i], &desc);
+		if (ret)
+			continue;
+
+		if ((desc.idVendor != USB_VID) || (desc.idProduct != USB_PID))
+			continue;
+
+		_e1_usb_open_device(e1d, dev_list[i]);
+	}
+
+	libusb_free_device_list(dev_list, 1);
+
+	return 0;
+}
+
+int
+e1_usb_poll(void)
+{
+	int rv;
+
+	rv = libusb_handle_events(g_usb);
+	if (rv != LIBUSB_SUCCESS)
+		return -EIO;
+
+	return 0;
+}