lynxis lazus has uploaded this change for review.
gprs_gmm: Use gprs_gmm_parse_att_req() to parse Attach Request
gprs_gmm_parse_att_req() is a parser for Attach Request, use it.
Change-Id: Iee3c66d6ab21ead103241753f927d9245aad9e64
---
M src/sgsn/gprs_gmm.c
1 file changed, 22 insertions(+), 54 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/osmo-sgsn refs/changes/95/43595/1
diff --git a/src/sgsn/gprs_gmm.c b/src/sgsn/gprs_gmm.c
index 3d4b940..c32bb7b 100644
--- a/src/sgsn/gprs_gmm.c
+++ b/src/sgsn/gprs_gmm.c
@@ -1244,20 +1244,22 @@
static int gsm48_rx_gmm_att_req(struct sgsn_mm_ctx *ctx, struct msgb *msg,
struct gprs_llc_llme *llme)
{
- struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_gmmh(msg);
- uint8_t *cur = gh->data, *msnc, *mi_data, *ms_ra_acc_cap;
- uint8_t msnc_len, att_type, mi_len, ms_ra_acc_cap_len;
- uint16_t drx_par;
+ struct gprs_gmm_att_req req = {};
char mi_log_string[32];
struct osmo_routing_area_id rai;
uint16_t cid = 0;
enum gsm48_gmm_cause reject_cause;
- struct osmo_mobile_identity mi;
int rc;
LOGMMCTXP(LOGL_INFO, ctx, "-> GMM ATTACH REQUEST ");
rate_ctr_inc(rate_ctr_group_get_ctr(sgsn->rate_ctrs, CTR_GPRS_ATTACH_REQUEST));
+ rc = gprs_gmm_parse_att_req(msg, &req);
+ if (rc) {
+ LOGP(DMM, LOGL_ERROR, "Invalid Attach Request message received.\n");
+ goto err_inval;
+ }
+
/* As per TS 04.08 Chapter 4.7.1.4, the attach request arrives either
* with a foreign TLLI (P-TMSI that was allocated to the MS before),
* or with random TLLI. */
@@ -1274,58 +1276,23 @@
#endif
}
- /* MS network capability 10.5.5.12 */
- msnc_len = *cur++;
- msnc = cur;
- if (msnc_len > sizeof(ctx->ms_network_capa.buf))
- goto err_inval;
- cur += msnc_len;
-
/* TODO: In iu mode - handle follow-on request.
* The follow-on request can be signaled in an Attach Request on IuPS.
* This means the MS/UE asks to keep the PS connection open for further requests
* after the Attach Request succeed.
* The SGSN can decide if it close the connection or not. Both are spec conform. */
- /* aTTACH Type 10.5.5.2 */
- att_type = *cur++ & 0x07;
-
- /* DRX parameter 10.5.5.6 */
- drx_par = *cur++ << 8;
- drx_par |= *cur++;
-
- /* Mobile Identity (P-TMSI or IMSI) 10.5.1.4 */
- mi_len = *cur++;
- mi_data = cur;
- cur += mi_len;
-
- rc = osmo_mobile_identity_decode(&mi, mi_data, mi_len, false);
- if (rc)
- goto err_inval;
- osmo_mobile_identity_to_str_buf(mi_log_string, sizeof(mi_log_string), &mi);
-
- DEBUGPC(DMM, "MI(%s) type=\"%s\" ", mi_log_string,
- get_value_string(gprs_att_t_strs, att_type));
-
- /* Old routing area identification 10.5.5.15. Skip it */
- cur += 6;
-
- /* MS Radio Access Capability 10.5.5.12a */
- ms_ra_acc_cap_len = *cur++;
- ms_ra_acc_cap = cur;
- if (ms_ra_acc_cap_len > sizeof(ctx->ms_radio_access_capa.buf))
- goto err_inval;
- cur += ms_ra_acc_cap_len;
-
- LOGPC(DMM, LOGL_INFO, "\n");
+ osmo_mobile_identity_to_str_buf(mi_log_string, sizeof(mi_log_string), &req.mi);
+ LOGPC(DMM, LOGL_INFO, "MI(%s) type=\"%s\" ", mi_log_string,
+ get_value_string(gprs_att_t_strs, req.attach_type));
/* Optional: Old P-TMSI Signature, Requested READY timer, TMSI Status */
- switch (mi.type) {
+ switch (req.mi.type) {
case GSM_MI_TYPE_IMSI:
/* Try to find MM context based on IMSI */
if (!ctx)
- ctx = sgsn_mm_ctx_by_imsi(mi.imsi);
+ ctx = sgsn_mm_ctx_by_imsi(req.mi.imsi);
if (!ctx) {
if (MSG_IU_UE_CTX(msg))
ctx = sgsn_mm_ctx_alloc_iu(MSG_IU_UE_CTX(msg));
@@ -1335,13 +1302,13 @@
reject_cause = GMM_CAUSE_NET_FAIL;
goto rejected;
}
- OSMO_STRLCPY_ARRAY(ctx->imsi, mi.imsi);
+ OSMO_STRLCPY_ARRAY(ctx->imsi, req.mi.imsi);
}
break;
case GSM_MI_TYPE_TMSI:
/* Try to find MM context based on P-TMSI */
if (!ctx)
- ctx = sgsn_mm_ctx_by_ptmsi(mi.tmsi);
+ ctx = sgsn_mm_ctx_by_ptmsi(req.mi.tmsi);
if (!ctx) {
/* Allocate a context as most of our code expects one.
* Context will not have an IMSI ultil ID RESP is received */
@@ -1353,7 +1320,7 @@
reject_cause = GMM_CAUSE_NET_FAIL;
goto rejected;
}
- ctx->p_tmsi = mi.tmsi;
+ ctx->p_tmsi = req.mi.tmsi;
}
break;
default:
@@ -1377,14 +1344,15 @@
ctx->gb.cell_id = cid;
/* Update MM Context with other data */
- ctx->drx_parms = drx_par;
- ctx->ms_radio_access_capa.len = ms_ra_acc_cap_len;
- memcpy(ctx->ms_radio_access_capa.buf, ms_ra_acc_cap,
+ ctx->drx_parms = req.drx_parms;
+ ctx->ms_radio_access_capa.len = OSMO_MIN(req.ms_radio_cap_len, sizeof(ctx->ms_radio_access_capa.buf));
+ memcpy(ctx->ms_radio_access_capa.buf, req.ms_radio_cap,
ctx->ms_radio_access_capa.len);
- ctx->ms_network_capa.len = msnc_len;
- memcpy(ctx->ms_network_capa.buf, msnc, msnc_len);
- ctx->ue_cipher_mask = gprs_ms_net_cap_gea_mask(ctx->ms_network_capa.buf, msnc_len);
+ ctx->ms_network_capa.len = OSMO_MIN(req.ms_network_cap_len, sizeof(ctx->ms_network_capa.buf));
+ memcpy(ctx->ms_network_capa.buf, req.ms_network_cap, ctx->ms_network_capa.len);
+
+ ctx->ue_cipher_mask = gprs_ms_net_cap_gea_mask(ctx->ms_network_capa.buf, ctx->ms_network_capa.len);
if (!(ctx->ue_cipher_mask & sgsn->cfg.gea_encryption_mask)) {
reject_cause = GMM_CAUSE_PROTO_ERR_UNSPEC;
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