Public release of the cellmgr_ng code to convert E1 to IPA SCCP

3 files changed, 226 insertions, 0 deletions

diff --git a/src/openbsc_nat/README b/src/openbsc_nat/README
new file mode 100644
index 0000000..9393d56
--- /dev/null
+++ b/src/openbsc_nat/README
@@ -0,0 +1 @@
+This is OpenBSC code. Do not patch. Fix it upstream.
diff --git a/src/openbsc_nat/bssap.c b/src/openbsc_nat/bssap.c
new file mode 100644
index 0000000..8ffdf04
--- /dev/null
+++ b/src/openbsc_nat/bssap.c
@@ -0,0 +1,65 @@
+/* GSM 08.08 BSSMAP handling						*/
+/* (C) 2009 by Holger Hans Peter Freyther <zecke@selfish.org>
+ * (C) 2009 by on-waves.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 <openbsc_nat/bssap.h>
+#include <openbsc_nat/tlv.h>
+
+#include <sccp/sccp.h>
+
+#include <arpa/inet.h>
+#include <assert.h>
+
+
+#define BSSMAP_MSG_SIZE 512
+#define BSSMAP_MSG_HEADROOM 128
+
+
+static const struct tlv_definition bss_att_tlvdef = {
+	.def = {
+		[GSM0808_IE_IMSI]		    = { TLV_TYPE_TLV },
+		[GSM0808_IE_TMSI]		    = { TLV_TYPE_TLV },
+		[GSM0808_IE_CELL_IDENTIFIER_LIST]   = { TLV_TYPE_TLV },
+		[GSM0808_IE_CHANNEL_NEEDED]	    = { TLV_TYPE_TV },
+		[GSM0808_IE_EMLPP_PRIORITY]	    = { TLV_TYPE_TV },
+		[GSM0808_IE_CHANNEL_TYPE]	    = { TLV_TYPE_TLV },
+		[GSM0808_IE_PRIORITY]		    = { TLV_TYPE_TLV },
+		[GSM0808_IE_CIRCUIT_IDENTITY_CODE]  = { TLV_TYPE_TV },
+		[GSM0808_IE_DOWNLINK_DTX_FLAG]	    = { TLV_TYPE_TV },
+		[GSM0808_IE_INTERFERENCE_BAND_TO_USE] = { TLV_TYPE_TV },
+		[GSM0808_IE_CLASSMARK_INFORMATION_T2] = { TLV_TYPE_TLV },
+		[GSM0808_IE_GROUP_CALL_REFERENCE]   = { TLV_TYPE_TLV },
+		[GSM0808_IE_TALKER_FLAG]	    = { TLV_TYPE_T },
+		[GSM0808_IE_CONFIG_EVO_INDI]	    = { TLV_TYPE_TV },
+		[GSM0808_IE_LSA_ACCESS_CTRL_SUPPR]  = { TLV_TYPE_TV },
+		[GSM0808_IE_SERVICE_HANDOVER]	    = { TLV_TYPE_TV},
+		[GSM0808_IE_ENCRYPTION_INFORMATION] = { TLV_TYPE_TLV },
+		[GSM0808_IE_CIPHER_RESPONSE_MODE]   = { TLV_TYPE_TV },
+		[GSM0808_IE_SPEECH_VERSION]	    = { TLV_TYPE_TV },
+		[GSM0808_IE_CHOSEN_ENCR_ALG]	    = { TLV_TYPE_TV },
+		[GSM0808_IE_CHOSEN_CHANNEL]	    = { TLV_TYPE_TV },
+	},
+};
+
+const struct tlv_definition *gsm0808_att_tlvdef()
+{
+	return &bss_att_tlvdef;
+}
+
diff --git a/src/openbsc_nat/tlv_parser.c b/src/openbsc_nat/tlv_parser.c
new file mode 100644
index 0000000..e44b3a1
--- /dev/null
+++ b/src/openbsc_nat/tlv_parser.c
@@ -0,0 +1,160 @@
+#include <stdio.h>
+#include <openbsc_nat/tlv.h>
+
+#ifndef ARRAY_SIZE
+#define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]))
+#endif
+
+struct tlv_definition tvlv_att_def;
+
+int tlv_dump(struct tlv_parsed *dec)
+{
+	int i;
+
+	for (i = 0; i <= 0xff; i++) {
+		if (!dec->lv[i].val)
+			continue;
+		printf("T=%02x L=%d\n", i, dec->lv[i].len);
+	}
+	return 0;
+}
+
+/* o_tag:  output: tag found
+ * o_len:  output: length of the data
+ * o_val:  output: pointer to the data
+ * def:     input: a structure defining the valid TLV tags / configurations
+ * buf:     input: the input data buffer to be parsed
+ * buf_len: input: the length of the input data buffer
+ *
+ * Also, returns the number of bytes consumed by the TLV entry
+ */
+int tlv_parse_one(u_int8_t *o_tag, u_int16_t *o_len, const u_int8_t **o_val,
+		  const struct tlv_definition *def,
+		  const u_int8_t *buf, int buf_len)
+{
+	u_int8_t tag;
+	int len;
+
+	tag = *buf;
+	*o_tag = tag;
+
+	/* FIXME: use tables for knwon IEI */
+	switch (def->def[tag].type) {
+	case TLV_TYPE_T:
+		/* GSM TS 04.07 11.2.4: Type 1 TV or Type 2 T */
+		*o_val = buf;
+		*o_len = 0;
+		len = 1;
+		break;
+	case TLV_TYPE_TV:
+		*o_val = buf+1;
+		*o_len = 1;
+		len = 2;
+		break;
+	case TLV_TYPE_FIXED:
+		*o_val = buf+1;
+		*o_len = def->def[tag].fixed_len;
+		len = def->def[tag].fixed_len + 1;
+		break;
+	case TLV_TYPE_TLV:
+		/* GSM TS 04.07 11.2.4: Type 4 TLV */
+		if (buf + 1 > buf + buf_len)
+			return -1;
+		*o_val = buf+2;
+		*o_len = *(buf+1);
+		len = *o_len + 2;
+		if (len > buf_len)
+			return -2;
+		break;
+	case TLV_TYPE_TvLV:
+		if (*(buf+1) & 0x80) {
+			/* like TLV, but without highest bit of len */
+			if (buf + 1 > buf + buf_len)
+				return -1;
+			*o_val = buf+2;
+			*o_len = *(buf+1) & 0x7f;
+			len = *o_len + 2;
+			if (len > buf_len)
+				return -2;
+			break;
+		}
+		/* like TL16V, fallthrough */
+	case TLV_TYPE_TL16V:
+		if (2 > buf_len)
+			return -1;
+		*o_val = buf+3;
+		*o_len = *(buf+1) << 8 | *(buf+2);
+		len = *o_len + 3;
+		if (len > buf_len)
+			return -2;
+		break;
+	default:
+		return -3;
+	}
+
+	return len;
+}
+
+/* dec:    output: a caller-allocated pointer to a struct tlv_parsed,
+ * def:     input: a structure defining the valid TLV tags / configurations
+ * buf:     input: the input data buffer to be parsed
+ * buf_len: input: the length of the input data buffer
+ * lv_tag:  input: an initial LV tag at the start of the buffer
+ * lv_tag2: input: a second initial LV tag following lv_tag 
+ */
+int tlv_parse(struct tlv_parsed *dec, const struct tlv_definition *def,
+	      const u_int8_t *buf, int buf_len, u_int8_t lv_tag,
+	      u_int8_t lv_tag2)
+{
+	int ofs = 0, num_parsed = 0;
+	u_int16_t len;
+
+	memset(dec, 0, sizeof(*dec));
+
+	if (lv_tag) {
+		if (ofs > buf_len)
+			return -1;
+		dec->lv[lv_tag].val = &buf[ofs+1];
+		dec->lv[lv_tag].len = buf[ofs];
+		len = dec->lv[lv_tag].len + 1;
+		if (ofs + len > buf_len)
+			return -2;
+		num_parsed++;
+		ofs += len;
+	}
+	if (lv_tag2) {
+		if (ofs > buf_len)
+			return -1;
+		dec->lv[lv_tag2].val = &buf[ofs+1];
+		dec->lv[lv_tag2].len = buf[ofs];
+		len = dec->lv[lv_tag2].len + 1;
+		if (ofs + len > buf_len)
+			return -2;
+		num_parsed++;
+		ofs += len;
+	}
+
+	while (ofs < buf_len) {
+		int rv;
+		u_int8_t tag;
+		const u_int8_t *val;
+
+		rv = tlv_parse_one(&tag, &len, &val, def,
+		                   &buf[ofs], buf_len-ofs);
+		if (rv < 0)
+			return rv;
+		dec->lv[tag].val = val;
+		dec->lv[tag].len = len;
+		ofs += rv;
+		num_parsed++;
+	}
+	//tlv_dump(dec);
+	return num_parsed;
+}
+
+static __attribute__((constructor)) void on_dso_load_tlv(void)
+{
+	int i;
+	for (i = 0; i < ARRAY_SIZE(tvlv_att_def.def); i++)
+		tvlv_att_def.def[i].type = TLV_TYPE_TvLV;
+}