respond to HNBAP UE REGISTER REQ withe correspnding ACCEPT
The Accept incudes the IMSI that the phone presented, but
somehow we fail to encode the Context ID as bitstring, see
../pcap/20150911-hnbap-ue_register.pcap
diff --git a/src/hnbgw_hnbap.c b/src/hnbgw_hnbap.c
index d00d59e..7810573 100644
--- a/src/hnbgw_hnbap.c
+++ b/src/hnbgw_hnbap.c
@@ -1,5 +1,6 @@
#include <osmocom/core/msgb.h>
#include <osmocom/core/utils.h>
+#include <osmocom/gsm/gsm48.h>
#include <unistd.h>
#include <errno.h>
@@ -23,6 +24,51 @@
return osmo_wqueue_enqueue(&ctx->wqueue, msg);
}
+int decode_iu_bcd(char *out, size_t out_len, const uint8_t *in, size_t in_len)
+{
+ const uint8_t *ch;
+ char *outch = out;
+
+ for (ch = in; ch < in + in_len; ch++) {
+ char c = osmo_bcd2char(*ch & 0xF);
+ *outch++ = c;
+ if (outch + 1 >= out + out_len)
+ break;
+ c = osmo_bcd2char(*ch >> 4);
+ /* skip padding nibble at end */
+ if (c == 'F')
+ break;
+ *outch++ = c;
+ }
+ *outch++ = '\0';
+ return outch - out;
+}
+
+int encode_iu_imsi(uint8_t *out, size_t out_len,
+ const char *in)
+{
+ unsigned int len = strlen(in);
+ uint8_t odd = (len & 0x01) == 1;
+ unsigned int off = 0;
+ unsigned int i;
+
+ len /= 2;
+ if (odd)
+ len++;
+
+ for (i = 0; i < len; i++) {
+ uint8_t lower, upper;
+
+ lower = osmo_char2bcd(in[++off]) & 0x0f;
+ if (!odd && off + 1 == len)
+ upper = 0x0f;
+ else
+ upper = osmo_char2bcd(in[++off]) & 0x0f;
+
+ out[i] = (upper << 4) | lower;
+ }
+ return i;
+}
static int hnbgw_tx_hnb_register_acc(struct hnb_context *ctx)
{
@@ -57,10 +103,15 @@
UERegisterAccept_t accept_out;
UERegisterAcceptIEs_t accept;
struct msgb *msg;
+ uint8_t encoded_imsi[10];
+ size_t encoded_imsi_len;
int rc;
- /* FIXME accept.uE_Identity; */
+ encoded_imsi_len = encode_iu_imsi(encoded_imsi, sizeof(encoded_imsi), ue->imsi);
+
memset(&accept, 0, sizeof(accept));
+ accept.uE_Identity.present = UE_Identity_PR_iMSI;
+ OCTET_STRING_fromBuf(&accept.uE_Identity.choice.iMSI, (const char *)encoded_imsi, encoded_imsi_len);
asn1_u32_to_bitstring(&accept.context_ID, &ue->context_id);
memset(&accept_out, 0, sizeof(accept_out));
@@ -105,19 +156,37 @@
{
UERegisterRequestIEs_t ies;
struct ue_context *ue;
+ char imsi[16];
int rc;
rc = hnbap_decode_ueregisterrequesties(&ies, in);
if (rc < 0)
return rc;
- /* FIXME: convert UE identity into a more palatable format */
- ue = ue_context_by_imsi("123");
- if (!ue)
- ue = ue_context_alloc(ctx, "123");
+ switch (ies.uE_Identity.present) {
+ case UE_Identity_PR_iMSI:
+ decode_iu_bcd(imsi, sizeof(imsi), ies.uE_Identity.choice.iMSI.buf,
+ ies.uE_Identity.choice.iMSI.size);
+ break;
+ case UE_Identity_PR_iMSIDS41:
+ decode_iu_bcd(imsi, sizeof(imsi), ies.uE_Identity.choice.iMSIDS41.buf,
+ ies.uE_Identity.choice.iMSIDS41.size);
+ break;
+ case UE_Identity_PR_iMSIESN:
+ decode_iu_bcd(imsi, sizeof(imsi), ies.uE_Identity.choice.iMSIESN.iMSIDS41.buf,
+ ies.uE_Identity.choice.iMSIESN.iMSIDS41.size);
+ break;
+ default:
+ DEBUGP(DMAIN, "UE-REGISTER-REQ without IMSI?!?\n");
+ return -1;
+ }
- DEBUGP(DMAIN, "UE-REGSITER-REQ ID_type=%d cause=%ld\n",
- ies.uE_Identity.present, ies.registration_Cause);
+ DEBUGP(DMAIN, "UE-REGSITER-REQ ID_type=%d imsi=%s cause=%ld\n",
+ ies.uE_Identity.present, imsi, ies.registration_Cause);
+
+ ue = ue_context_by_imsi(imsi);
+ if (!ue)
+ ue = ue_context_alloc(ctx, imsi);
/* Send UERegisterAccept */
return hnbgw_tx_ue_register_acc(ue);