Introduce LLC layer that has been completely missign so far

All our MM/CMCE/SNDCP 'decodes' were broken previously, as they
assumed that the MM/CMCE/SNDCP message follows immediately after the
MAC header.  However, there's the LLC layer in between.

This is just simple LLC decoding and does not do re-assembly yet.

src/Makefile

@@ -9,7 +9,7 @@ all: conv_enc_test crc_test tetra-rx float_to_bits
 libosmo-tetra-phy.a: phy/tetra_burst_sync.o phy/tetra_burst.o
 	$(AR) r $@ $^
 
-libosmo-tetra-mac.a: lower_mac/tetra_conv_enc.o tetra_tdma.o lower_mac/tetra_scramb.o lower_mac/tetra_rm3014.o lower_mac/tetra_interleave.o lower_mac/crc_simple.o tetra_common.o lower_mac/viterbi.o lower_mac/viterbi_cch.o lower_mac/viterbi_tch.o lower_mac/tetra_lower_mac.o tetra_upper_mac.o tetra_mac_pdu.o tetra_mle_pdu.o tetra_mm_pdu.o tetra_cmce_pdu.o tetra_sndcp_pdu.o tetra_gsmtap.o
+libosmo-tetra-mac.a: lower_mac/tetra_conv_enc.o tetra_tdma.o lower_mac/tetra_scramb.o lower_mac/tetra_rm3014.o lower_mac/tetra_interleave.o lower_mac/crc_simple.o tetra_common.o lower_mac/viterbi.o lower_mac/viterbi_cch.o lower_mac/viterbi_tch.o lower_mac/tetra_lower_mac.o tetra_upper_mac.o tetra_mac_pdu.o tetra_llc_pdu.o tetra_mle_pdu.o tetra_mm_pdu.o tetra_cmce_pdu.o tetra_sndcp_pdu.o tetra_gsmtap.o
 	$(AR) r $@ $^
 
 float_to_bits: float_to_bits.o

src/tetra_llc_pdu.c

@@ -0,0 +1,166 @@
+/* Implementation of some PDU parsing of the TETRA LLC */
+
+/* (C) 2011 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 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 <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <errno.h>
+
+#include <osmocom/core/utils.h>
+
+#include "tetra_common.h"
+#include "tetra_llc_pdu.h"
+
+static const struct value_string tetra_llc_pdut_names[] = {
+	{ TLLC_PDUT_BL_ADATA,		"BL-ADATA" },
+	{ TLLC_PDUT_BL_DATA,		"BL-DATA" },
+	{ TLLC_PDUT_BL_UDATA,		"BL-UDATA" },
+	{ TLLC_PDUT_BL_ACK,		"BL-ACK" },
+	{ TLLC_PDUT_BL_ADATA_FCS,	"BL-ADATA-FCS" },
+	{ TLLC_PDUT_BL_DATA_FCS,	"BL-DATA-FCS" },
+	{ TLLC_PDUT_BL_UDATA_FCS,	"BL-UDATA-FCS" },
+	{ TLLC_PDUT_BL_ACK_FCS,		"BL-ACK-FCS" },
+	{ TLLC_PDUT_AL_SETUP,		"AL-SETUP" },
+	{ TLLC_PDUT_AL_DATA_FINAL,	"AL-DATA/FINAL" },
+	{ TLLC_PDUT_AL_UDATA_UFINAL,	"AL-UDATA/FINAL" },
+	{ TLLC_PDUT_AL_ACK_RNR,		"AL-ACK/AL-RNR" },
+	{ TLLC_PDUT_AL_RECONNECT,	"AL-RECONNECT" },
+	{ TLLC_PDUT_SUPPL,		"AL-SUPPLEMENTARY" },
+	{ TLLC_PDUT_L2SIG,		"AL-L2SIG" },
+	{ TLLD_PDUT_AL_DISC,		"AL-DISC" },
+	{ 0, NULL }
+};
+const char *tetra_get_llc_pdut_name(uint8_t pdut)
+{
+	return get_value_string(tetra_llc_pdut_names, pdut);
+}
+
+static const struct value_string pdut_dec_names[] = {
+	{ TLLC_PDUT_DEC_BL_ADATA,	"BL-ADATA" },
+	{ TLLC_PDUT_DEC_BL_DATA,	"BL-DATA" },
+	{ TLLC_PDUT_DEC_BL_UDATA,	"BL-UDATA" },
+	{ TLLC_PDUT_DEC_BL_ACK,		"BL-ACK" },
+	{ TLLC_PDUT_DEC_AL_SETUP,	"AL-SETUP" },
+	{ TLLC_PDUT_DEC_AL_DATA,	"AL-DATA" },
+	{ TLLC_PDUT_DEC_AL_FINAL,	"AL-FINAL" },
+	{ TLLC_PDUT_DEC_AL_UDATA,	"AL-UDATA" },
+	{ TLLC_PDUT_DEC_AL_UFINAL,	"AL-UFINAL" },
+	{ TLLC_PDUT_DEC_AL_ACK,		"AL-ACK" },
+	{ TLLC_PDUT_DEC_AL_RNR,		"AL-RNR" },
+	{ TLLC_PDUT_DEC_AL_RECONNECT,	"AL-RECONNECT" },
+	{ TLLC_PDUT_DEC_AL_DISC,	"AL-DISC" },
+	{ TLLC_PDUT_DEC_ALX_DATA,	"ALX-DATA" },
+	{ TLLC_PDUT_DEC_ALX_FINAL,	"ALX-FINAL" },
+	{ TLLC_PDUT_DEC_ALX_UDATA,	"ALX-UDATA" },
+	{ TLLC_PDUT_DEC_ALX_UFINAL,	"ALX-UFINAL" },
+	{ TLLC_PDUT_DEC_ALX_ACK,	"ALX-ACK" },
+	{ TLLC_PDUT_DEC_ALX_RNR,	"ALX-RNR" },
+	{ 0, NULL }
+};
+
+const char *tetra_get_llc_pdut_dec_name(enum tllc_pdut_dec pdut)
+{
+	return get_value_string(pdut_dec_names, pdut);
+}
+
+int tetra_llc_pdu_parse(struct tetra_llc_pdu *lpp, uint8_t *buf, int len)
+{
+	uint8_t *cur = buf;
+	uint8_t pdu_type;
+
+	pdu_type = bits_to_uint(cur, 4);
+	cur += 4;
+
+	switch (pdu_type) {
+	case TLLC_PDUT_BL_ADATA_FCS:
+		/* FIXME */
+		len -= 32;
+	case TLLC_PDUT_BL_ADATA:
+		lpp->nr = *cur++;
+		lpp->ns = *cur++;
+		lpp->tl_sdu = cur;
+		lpp->tl_sdu_len = len - (cur - buf);
+		lpp->pdu_type = TLLC_PDUT_DEC_BL_ADATA;
+		break;
+	case TLLC_PDUT_BL_DATA_FCS:
+		/* FIXME */
+		len -= 32;
+	case TLLC_PDUT_BL_DATA:
+		lpp->ns = *cur++;
+		lpp->tl_sdu = cur;
+		lpp->tl_sdu_len = len - (cur - buf);
+		lpp->pdu_type = TLLC_PDUT_DEC_BL_DATA;
+		break;
+	case TLLC_PDUT_BL_UDATA_FCS:
+		/* FIXME */
+		len -= 32;
+	case TLLC_PDUT_BL_UDATA:
+		lpp->tl_sdu = cur;
+		lpp->tl_sdu_len = len - (cur - buf);
+		lpp->pdu_type = TLLC_PDUT_DEC_BL_UDATA;
+		break;
+	case TLLC_PDUT_AL_DATA_FINAL:
+		if (*cur++) {
+			/* FINAL */
+			cur++;
+			cur += 2;
+			lpp->ns = bits_to_uint(cur, 5); cur += 5;
+			lpp->ss = bits_to_uint(cur, 8); cur += 8;
+			if (*cur++) {
+				/* FIXME: FCS */
+				len -= 32;
+			}
+			lpp->tl_sdu = cur;
+			lpp->tl_sdu_len = len - (cur - buf);
+			lpp->pdu_type = TLLC_PDUT_DEC_AL_FINAL;
+		} else {
+			/* DATA Table 21.19 */
+			cur++;
+			lpp->ns = bits_to_uint(cur, 3); cur += 3;
+			lpp->ss = bits_to_uint(cur, 8); cur += 8;
+			lpp->tl_sdu = cur;
+			lpp->tl_sdu_len = len - (cur - buf);
+			lpp->pdu_type = TLLC_PDUT_DEC_AL_DATA;
+		}
+		break;
+	case TLLC_PDUT_AL_UDATA_UFINAL:
+		if (*cur++) {
+			/* UFINAL 21.2.3.7 / Table 21.26 */
+			lpp->ns = bits_to_uint(cur, 8); cur+= 8;
+			lpp->ss = bits_to_uint(cur, 8); cur+= 8;
+			lpp->tl_sdu = cur;
+			/* FIXME: FCS */
+			len -= 32;
+			lpp->tl_sdu_len = len - (cur - buf);
+			lpp->pdu_type = TLLC_PDUT_DEC_AL_UFINAL;
+		} else {
+			/* UDATA 21.2.3.6 / Table 21.24 */
+			lpp->ns = bits_to_uint(cur, 8); cur+= 8;
+			lpp->ss = bits_to_uint(cur, 8); cur+= 8;
+			lpp->tl_sdu = cur;
+			lpp->tl_sdu_len = len - (cur - buf);
+			lpp->pdu_type = TLLC_PDUT_DEC_AL_UDATA;
+		}
+		break;
+	}
+	return (cur - buf);
+}

src/tetra_llc_pdu.h

@@ -0,0 +1,80 @@
+#ifndef TETRA_LLC_PDU_H
+#define TETRA_LLC_PDU_H
+
+/* Table 21.1 */
+enum tetra_llc_pdu_t {
+	TLLC_PDUT_BL_ADATA		= 0,
+	TLLC_PDUT_BL_DATA		= 1,
+	TLLC_PDUT_BL_UDATA		= 2,
+	TLLC_PDUT_BL_ACK		= 3,
+	TLLC_PDUT_BL_ADATA_FCS		= 4,
+	TLLC_PDUT_BL_DATA_FCS		= 5,
+	TLLC_PDUT_BL_UDATA_FCS		= 6,
+	TLLC_PDUT_BL_ACK_FCS		= 7,
+	TLLC_PDUT_AL_SETUP		= 8,
+	TLLC_PDUT_AL_DATA_FINAL		= 9,
+	TLLC_PDUT_AL_UDATA_UFINAL	= 10,
+	TLLC_PDUT_AL_ACK_RNR		= 11,
+	TLLC_PDUT_AL_RECONNECT		= 12,
+	TLLC_PDUT_SUPPL			= 13,
+	TLLC_PDUT_L2SIG			= 14,
+	TLLD_PDUT_AL_DISC		= 15
+};
+const char *tetra_get_llc_pdut_name(uint8_t pdut);
+
+/* Table 21.2 */
+enum tetra_llc_l2sig_pdu_t {
+	TLLC_PDUT_L2_DATA_PRIO		= 0,
+	TLLC_PDUT_L2_SCHEDULE_SYNC	= 1,
+	TLLC_PDUT_L2_LINK_FB_CTRL	= 2,
+	TLLC_PDUT_L2_LINK_FB_INFO	= 3,
+	TLLC_PDUT_L2_LINK_FB_INFO_RD_PRIO = 4
+};
+
+/* Table 21.3 */
+enum tetra_llc_suppl_pdu_t {
+	TLLC_PDUT_SUPPL_ALX_DATA_FINAL	= 0,
+	TLLC_PDUT_SUPPL_ALX_UDATA_UFINAL = 1,
+	TLLC_PDUT_SUPPL_ALX_ACK_RNR	= 2
+};
+
+/* Decoded */
+
+enum tllc_pdut_dec {
+	TLLC_PDUT_DEC_UNKNOWN,
+	TLLC_PDUT_DEC_BL_ADATA,
+	TLLC_PDUT_DEC_BL_DATA,
+	TLLC_PDUT_DEC_BL_UDATA,
+	TLLC_PDUT_DEC_BL_ACK,
+	TLLC_PDUT_DEC_AL_SETUP,
+	TLLC_PDUT_DEC_AL_DATA,
+	TLLC_PDUT_DEC_AL_FINAL,
+	TLLC_PDUT_DEC_AL_UDATA,
+	TLLC_PDUT_DEC_AL_UFINAL,
+	TLLC_PDUT_DEC_AL_ACK,
+	TLLC_PDUT_DEC_AL_RNR,
+	TLLC_PDUT_DEC_AL_RECONNECT,
+	TLLC_PDUT_DEC_AL_DISC,
+	TLLC_PDUT_DEC_ALX_DATA,
+	TLLC_PDUT_DEC_ALX_FINAL,
+	TLLC_PDUT_DEC_ALX_UDATA,
+	TLLC_PDUT_DEC_ALX_UFINAL,
+	TLLC_PDUT_DEC_ALX_ACK,
+	TLLC_PDUT_DEC_ALX_RNR,
+};
+const char *tetra_get_llc_pdut_dec_name(enum tllc_pdut_dec pdut);
+
+struct tetra_llc_pdu {
+	enum tllc_pdut_dec pdu_type;
+	uint8_t nr;
+	uint8_t ns;
+	uint8_t ss;
+	uint32_t _fcs;
+	uint32_t *fcs;
+	uint8_t *tl_sdu;	/* pointer to bitbuf */
+	uint8_t tl_sdu_len;	/* in bits */
+};
+
+int tetra_llc_pdu_parse(struct tetra_llc_pdu *lpp, uint8_t *buf, int len);
+
+#endif /* TETRA_LLC_PDU_H */

src/tetra_upper_mac.c

@@ -29,7 +29,7 @@
 #include "tetra_prim.h"
 #include "tetra_upper_mac.h"
 #include "tetra_mac_pdu.h"
-#include "tetra_mle_pdu.h"
+#include "tetra_llc_pdu.h"
 #include "tetra_mm_pdu.h"
 #include "tetra_cmce_pdu.h"
 #include "tetra_sndcp_pdu.h"
@@ -95,11 +95,11 @@ const char *tetra_alloc_dump(const struct tetra_chan_alloc_decoded *cad)
 	return buf;
 }
 
-static int rx_tm_sdu(uint8_t *bits, unsigned int len)
+static int rx_tl_sdu(uint8_t *bits, unsigned int len)
 {
 	uint8_t mle_pdisc = bits_to_uint(bits, 3);
 
-	printf("TM-SDU(%s): %s", tetra_get_mle_pdisc_name(mle_pdisc),
+	printf("TL-SDU(%s): %s", tetra_get_mle_pdisc_name(mle_pdisc),
 		ubit_dump(bits, len));
 	switch (mle_pdisc) {
 	case TMLE_PDISC_MM:
@@ -120,6 +120,20 @@ static int rx_tm_sdu(uint8_t *bits, unsigned int len)
 	return len;
 }
 
+static int rx_tm_sdu(uint8_t *bits, unsigned int len)
+{
+	struct tetra_llc_pdu lpp;
+
+	memset(&lpp, 0, sizeof(lpp));
+	tetra_llc_pdu_parse(&lpp, bits, len);
+
+	printf("TM-SDU(%s): ", tetra_get_llc_pdut_dec_name(lpp.pdu_type));
+	if (lpp.tl_sdu) {
+		rx_tl_sdu(lpp.tl_sdu, lpp.tl_sdu_len);
+	}
+	return len;
+}
+
 static void rx_resrc(struct tetra_tmvsap_prim *tmvp)
 {
 	struct tmv_unitdata_param *tup = &tmvp->u.unitdata;