From 3e23ddf88b38f9316b61daff6f8f41e57e883a14 Mon Sep 17 00:00:00 2001 From: Jacob Erlbeck Date: Mon, 11 Aug 2014 15:07:37 +0200 Subject: gbproxy: Parse Detach Request messages GSM 24.008 also allows a P-TMSI field in Detach request messages. This patch adds gbprox_parse_gmm_detach_req() to parse Detach Request messages which sets the ptmsi field if the IE is present. In addition, when power_off is set to 1 (MO only), the invalidate_tlli field is set, since Detach Request message is expected in this case. The second detach test (see 'RA update') is modified to use power_off instead of relying on a Detach Accept from the network. To make this work, the PTMSI of the RA Update Accept is fixed to match the TLLI of the Detach Request. Sponsored-by: On-Waves ehf --- openbsc/src/gprs/gb_proxy.c | 47 +++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 43 insertions(+), 4 deletions(-) (limited to 'openbsc/src/gprs/gb_proxy.c') diff --git a/openbsc/src/gprs/gb_proxy.c b/openbsc/src/gprs/gb_proxy.c index 64fb55b77..dd7dead2b 100644 --- a/openbsc/src/gprs/gb_proxy.c +++ b/openbsc/src/gprs/gb_proxy.c @@ -959,6 +959,43 @@ static int gbprox_parse_gmm_attach_ack(uint8_t *data, size_t data_len, return 1; } +static int gbprox_parse_gmm_detach_req(uint8_t *data, size_t data_len, + struct gbproxy_parse_context *parse_ctx) +{ + uint8_t *value; + size_t value_len; + int detach_type; + int power_off; + + parse_ctx->llc_msg_name = "DETACH_REQ"; + + /* Skip spare half octet */ + /* Get Detach type */ + if (v_fixed_shift(&data, &data_len, 1, &value) <= 0) + /* invalid */ + return 0; + + detach_type = *value & 0x07; + power_off = *value & 0x08 ? 1 : 0; + + if (!parse_ctx->to_bss) { + /* Mobile originated */ + + if (power_off) + parse_ctx->invalidate_tlli = 1; + + /* Get P-TMSI (Mobile identity), see GSM 24.008, 9.4.5.2 */ + if (tlv_match(&data, &data_len, + GSM48_IE_GMM_ALLOC_PTMSI, &value, &value_len) > 0) + { + if (is_mi_tmsi(value, value_len)) + parse_ctx->ptmsi_enc = value; + } + } + + return 1; +} + static int gbprox_parse_gmm_ra_upd_req(uint8_t *data, size_t data_len, struct gbproxy_parse_context *parse_ctx) { @@ -1157,12 +1194,9 @@ static int gbprox_parse_dtap(uint8_t *data, size_t data_len, case GSM48_MT_GMM_ID_RESP: return gbprox_parse_gmm_id_resp(data, data_len, parse_ctx); - break; case GSM48_MT_GMM_DETACH_REQ: - /* TODO: Check power off if !to_bss, if yes invalidate */ - parse_ctx->llc_msg_name = "DETACH_REQ"; - break; + return gbprox_parse_gmm_detach_req(data, data_len, parse_ctx); case GSM48_MT_GMM_DETACH_ACK: parse_ctx->llc_msg_name = "DETACH_ACK"; @@ -1331,6 +1365,11 @@ static void gbprox_log_parse_context(struct gbproxy_parse_context *parse_ctx, sep, mi_buf); sep = ","; } + if (parse_ctx->invalidate_tlli) { + LOGP(DGPRS, LOGL_DEBUG, "%s invalidate", sep); + sep = ","; + } + LOGP(DGPRS, LOGL_DEBUG, "\n"); } -- cgit v1.2.3