* add trau_mux implementation to relay from one incoming TRAU
channel to another one (simple voice call switching)
* add a way more generic E1 input layer, abstracting out the misdn
low-level interface. This also adds infrastructure for multiple TRX
in one BTS, as well as multiple BTS on one E1 link
* add a E1 subchannel multiplexer for sending multiple 16kbit sub-channels
one one 64kBps E1 channel
* add TRAU IDLE frame generation
* terminate bsc_hack in case there is a E1 / mISDN init error
* introduce 'e1_config.c' file with static configuration of our
E1 setup (which TRX/BTS is configured for which TEI/SAPI/E1). This should
later become a config file rather than a compiled C file.
WARNING: all this compiles but is not tested yet. Expect fix-up committs over
the next hours or so
diff --git a/src/trau_mux.c b/src/trau_mux.c
new file mode 100644
index 0000000..753d01f
--- /dev/null
+++ b/src/trau_mux.c
@@ -0,0 +1,109 @@
+/* Simple TRAU frame reflector to route voice calls */
+
+/* (C) 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 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 <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+
+#include <openbsc/gsm_data.h>
+#include <openbsc/trau_frame.h>
+#include <openbsc/trau_mux.h>
+#include <openbsc/subchan_demux.h>
+#include <openbsc/e1_input.h>
+
+struct map_entry {
+ struct llist_head list;
+ struct gsm_e1_subslot src, dst;
+};
+
+static LLIST_HEAD(ss_map);
+
+/* map one particular subslot to another subslot */
+int trau_mux_map(const struct gsm_e1_subslot *src,
+ const struct gsm_e1_subslot *dst)
+{
+ struct map_entry *me = malloc(sizeof(*me));
+ if (!me)
+ return -ENOMEM;
+
+ memcpy(&me->src, src, sizeof(me->src));
+ memcpy(&me->dst, dst, sizeof(me->dst));
+ llist_add(&me->list, &ss_map);
+
+ return 0;
+}
+
+/* unmap one particular subslot from another subslot */
+int trau_mux_unmap(const struct gsm_e1_subslot *ss)
+{
+ struct map_entry *me, *me2;
+
+ llist_for_each_entry_safe(me, me2, &ss_map, list) {
+ if (!memcmp(&me->src, ss, sizeof(*ss)) ||
+ !memcmp(&me->dst, ss, sizeof(*ss))) {
+ llist_del(&me->list);
+ return 0;
+ }
+ }
+ return -ENOENT;
+}
+
+/* look-up an enty in the TRAU mux map */
+static struct gsm_e1_subslot *
+lookup_trau_mux_map(const struct gsm_e1_subslot *src)
+{
+ struct map_entry *me;
+
+ llist_for_each_entry(me, &ss_map, list) {
+ if (!memcmp(&me->src, src, sizeof(*src)))
+ return &me->dst;
+ if (!memcmp(&me->dst, src, sizeof(*src)))
+ return &me->src;
+ }
+ return NULL;
+}
+
+/* we get called by subchan_demux */
+int trau_mux_input(struct gsm_e1_subslot *src_e1_ss,
+ const u_int8_t *trau_bits, int num_bits)
+{
+ struct decoded_trau_frame tf;
+ u_int8_t trau_bits_out[TRAU_FRAME_BITS];
+ struct gsm_e1_subslot *dst_e1_ss = lookup_trau_mux_map(src_e1_ss);
+ struct subch_mux *mx;
+
+ if (!dst_e1_ss)
+ return -EINVAL;
+
+ mx = e1inp_get_mux(dst_e1_ss->e1_nr, dst_e1_ss->e1_ts);
+ if (!mx)
+ return -EINVAL;
+
+ /* decode TRAU, change it to downlink, re-encode */
+ decode_trau_frame(&tf, trau_bits);
+ trau_frame_up2down(&tf);
+ encode_trau_frame(trau_bits_out, &tf);
+
+ /* and send it to the muxer */
+ return subchan_mux_enqueue(mx, dst_e1_ss->e1_ts_ss, trau_bits_out,
+ TRAU_FRAME_BITS);
+}