(WIP) host/trxcon: add L1CTL PHY description and features

Change-Id: I175dc4858e3760e4e60f66658354a9d68d5231c7

src/host/trxcon/Makefile.am

@@ -27,6 +27,7 @@ trxcon_SOURCES = \
 	trx_if.c \
 	logging.c \
 	trxcon.c \
+	phy_info.c \
 	$(NULL)
 
 # Scheduler

src/host/trxcon/l1ctl.c

@@ -3,7 +3,7 @@
  * GSM L1 control interface handlers
  *
  * (C) 2014 by Sylvain Munaut <tnt@246tNt.com>
- * (C) 2016-2017 by Vadim Yanitskiy <axilirator@gmail.com>
+ * (C) 2016-2018 by Vadim Yanitskiy <axilirator@gmail.com>
  *
  * All Rights Reserved
  *
@@ -778,6 +778,39 @@ exit:
 	return rc;
 }
 
+/* Forward-declaration of the actual implementation */
+int trxcon_compose_phy_info(struct msgb *msg);
+
+static int l1ctl_rx_nego_req(struct l1ctl_link *l1l, struct msgb *msg)
+{
+	struct msgb *info_msg;
+	int rc;
+
+	LOGP(DL1C, LOGL_NOTICE, "PHY info / features negotiation\n");
+
+	/**
+	 * In the future the higher layers may also send some
+	 * information within negotiation request, so we don't
+	 * abuse this message (by changing its type),
+	 * and allocate a new one.
+	 */
+	msgb_free(msg);
+
+	info_msg = l1ctl_alloc_msg(L1CTL_PHY_NEGO_IND);
+	if (info_msg == NULL)
+		return -ENOMEM;
+
+	rc = trxcon_compose_phy_info(info_msg);
+	if (rc)
+		goto exit_free;
+
+	return l1ctl_link_send(l1l, info_msg);
+
+exit_free:
+	msgb_free(info_msg);
+	return rc;
+}
+
 int l1ctl_rx_cb(struct l1ctl_link *l1l, struct msgb *msg)
 {
 	struct l1ctl_hdr *l1h;
@@ -812,6 +845,8 @@ int l1ctl_rx_cb(struct l1ctl_link *l1l, struct msgb *msg)
 		return l1ctl_rx_tch_mode_req(l1l, msg);
 	case L1CTL_CRYPTO_REQ:
 		return l1ctl_rx_crypto_req(l1l, msg);
+	case L1CTL_PHY_NEGO_REQ:
+		return l1ctl_rx_nego_req(l1l, msg);
 
 	/* Not (yet) handled messages */
 	case L1CTL_NEIGH_PM_REQ:

src/host/trxcon/phy_info.c

@@ -0,0 +1,92 @@
+/*
+ * L1CTL PHY info / features negotiation
+ *
+ * (C) 2018 by Vadim Yanitskiy <axilirator@gmail.com>
+ *
+ * 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 <stdint.h>
+
+#include <arpa/inet.h>
+
+#include <osmocom/core/negotiation.h>
+#include <osmocom/core/utils.h>
+#include <osmocom/core/msgb.h>
+
+#include "l1ctl_proto.h"
+
+static const struct value_string phy_info[] = {
+	{L1CTL_PHY_INFO_NAME, "trxcon"},
+	{ 0, NULL }
+};
+
+int trxcon_compose_phy_info(struct msgb *msg)
+{
+	struct l1ctl_phy_nego_ind *hdr;
+	uint8_t *features_tlv;
+	int rc;
+
+	/* Header first */
+	hdr = (struct l1ctl_phy_nego_ind *) msgb_put(msg, sizeof(*hdr));
+	if (!hdr)
+		return -ENOMEM;
+
+	/* Encode basic PHY info */
+	rc = osmo_nego_enc_info(msg, phy_info);
+	if (rc < (ARRAY_SIZE(phy_info) - 1))
+		return -EINVAL;
+
+	/* PHY features TLV, length will be set latter */
+	features_tlv = msgb_put(msg, 2);
+	if (!features_tlv)
+		return -ENOMEM;
+
+	/* Frequency band support */
+	osmo_nego_add_feature(msg, L1CTL_PHY_FEATURE_BAND_400);
+	osmo_nego_add_feature(msg, L1CTL_PHY_FEATURE_BAND_850);
+	osmo_nego_add_feature(msg, L1CTL_PHY_FEATURE_BAND_900);
+	osmo_nego_add_feature(msg, L1CTL_PHY_FEATURE_BAND_DCS);
+	osmo_nego_add_feature(msg, L1CTL_PHY_FEATURE_BAND_PCS);
+
+	/* Channel coding support */
+	osmo_nego_add_feature(msg, L1CTL_PHY_FEATURE_CHAN_XCCH);
+	osmo_nego_add_feature(msg, L1CTL_PHY_FEATURE_CHAN_TCHF);
+
+	/* Voice codecs support */
+	osmo_nego_add_feature(msg, L1CTL_PHY_FEATURE_CODEC_FR);
+	osmo_nego_add_feature(msg, L1CTL_PHY_FEATURE_CODEC_EFR);
+
+	/* A5/X ciphering support */
+	osmo_nego_add_feature(msg, L1CTL_PHY_FEATURE_A5_1);
+	osmo_nego_add_feature(msg, L1CTL_PHY_FEATURE_A5_2);
+	osmo_nego_add_feature(msg, L1CTL_PHY_FEATURE_A5_3);
+
+	/* Other features */
+	osmo_nego_add_feature(msg, L1CTL_PHY_FEATURE_TX);
+	osmo_nego_add_feature(msg, L1CTL_PHY_FEATURE_PM);
+	osmo_nego_add_feature(msg, L1CTL_PHY_FEATURE_TRAFFIC);
+
+	/* Finally, compute the length fields */
+	features_tlv[0] = L1CTL_PHY_INFO_FEATURES;
+	features_tlv[1] = msg->tail - features_tlv - 2;
+	hdr->len = htons(msg->tail - hdr->data);
+
+	return 0;
+}