gprs_bssgp: add IE parser/generator for RIM Routing Information
The RIM Routing Information IE (see also 3GPP TS 48.018, section
11.3.70) is used to control the flow of BSSGP rim messages at the SGSN.
Change-Id: I6f88a9aeeb50a612d32e9efd23040c9740bc4f11
Related: SYS#5103
diff --git a/src/gb/gprs_bssgp.c b/src/gb/gprs_bssgp.c
index 696c451..09f6373 100644
--- a/src/gb/gprs_bssgp.c
+++ b/src/gb/gprs_bssgp.c
@@ -326,6 +326,93 @@
return 8;
}
+/*! Parse a RIM Routing information IE (3GPP TS 48.018, chapter 11.3.70).
+ * \param[out] ri user provided memory to store the parsed results.
+ * \param[in] buf input buffer of the value part of the IE.
+ * \returns length of parsed octets, -EINVAL on error. */
+int bssgp_parse_rim_ri(struct bssgp_rim_routing_info *ri, const uint8_t *buf,
+ unsigned int len)
+{
+ struct gprs_ra_id raid_temp;
+
+ memset(ri, 0, sizeof(*ri));
+ if (len < 2)
+ return -EINVAL;
+
+ ri->discr = buf[0] & 0x0f;
+
+ switch (ri->discr) {
+ case BSSGP_RIM_ROUTING_INFO_GERAN:
+ if (len < 9)
+ return -EINVAL;
+ ri->geran.cid = bssgp_parse_cell_id(&ri->geran.raid, buf + 1);
+ return 9;
+ case BSSGP_RIM_ROUTING_INFO_UTRAN:
+ if (len < 9)
+ return -EINVAL;
+ gsm48_parse_ra(&ri->utran.raid, buf + 1);
+ ri->utran.rncid = osmo_load16be(buf + 7);
+ return 9;
+ case BSSGP_RIM_ROUTING_INFO_EUTRAN:
+ if (len < 7 || len > 14)
+ return -EINVAL;
+ /* Note: 3GPP TS 24.301 Figure 9.9.3.32.1 and 3GPP TS 24.008
+ * Figure 10.5.130 specify MCC/MNC encoding in the same way,
+ * so we can re-use gsm48_parse_ra() for that. */
+ gsm48_parse_ra(&raid_temp, buf + 1);
+ ri->eutran.tai.mcc = raid_temp.mcc;
+ ri->eutran.tai.mnc = raid_temp.mnc;
+ ri->eutran.tai.mnc_3_digits = raid_temp.mnc_3_digits;
+ ri->eutran.tai.tac = osmo_load16be(buf + 4);
+ memcpy(ri->eutran.global_enb_id, buf + 6, len - 6);
+ ri->eutran.global_enb_id_len = len - 6;
+ return len;
+ default:
+ return -EINVAL;
+ }
+}
+
+/*! Encode a RIM Routing information IE (3GPP TS 48.018, chapter 11.3.70).
+ * \param[out] buf user provided memory (at least 14 byte) for the generated value part of the IE.
+ * \param[in] ri user provided input data struct.
+ * \returns length of encoded octets, -EINVAL on error. */
+int bssgp_create_rim_ri(uint8_t *buf, const struct bssgp_rim_routing_info *ri)
+{
+ int rc;
+ struct gprs_ra_id raid_temp;
+
+ buf[0] = ri->discr & 0x0f;
+ buf++;
+
+ switch (ri->discr) {
+ case BSSGP_RIM_ROUTING_INFO_GERAN:
+ rc = bssgp_create_cell_id(buf, &ri->geran.raid, ri->geran.cid);
+ if (rc < 0)
+ return -EINVAL;
+ return rc + 1;
+ case BSSGP_RIM_ROUTING_INFO_UTRAN:
+ gsm48_encode_ra((struct gsm48_ra_id *)buf, &ri->utran.raid);
+ osmo_store16be(ri->utran.rncid, buf + 6);
+ return 9;
+ case BSSGP_RIM_ROUTING_INFO_EUTRAN:
+ /* Note: 3GPP TS 24.301 Figure 9.9.3.32.1 and 3GPP TS 24.008
+ * Figure 10.5.130 specify MCC/MNC encoding in the same way,
+ * so we can re-use gsm48_encode_ra() for that. */
+ raid_temp.mcc = ri->eutran.tai.mcc;
+ raid_temp.mnc = ri->eutran.tai.mnc;
+ raid_temp.mnc_3_digits = ri->eutran.tai.mnc_3_digits;
+ gsm48_encode_ra((struct gsm48_ra_id *)buf, &raid_temp);
+ osmo_store16be(ri->eutran.tai.tac, buf + 3);
+ OSMO_ASSERT(ri->eutran.global_enb_id_len <=
+ sizeof(ri->eutran.global_enb_id));
+ memcpy(buf + 5, ri->eutran.global_enb_id,
+ ri->eutran.global_enb_id_len);
+ return ri->eutran.global_enb_id_len + 6;
+ default:
+ return -EINVAL;
+ }
+}
+
/* Chapter 8.4 BVC-Reset Procedure */
static int bssgp_rx_bvc_reset(struct msgb *msg, struct tlv_parsed *tp,
uint16_t ns_bvci)