store classmark in vlr_subscr, not conn
Store all Classmark information in the VLR.
So, we now always know the Classmark 1 (mandatory IE for LU). This is visible
in the msc_vlr_tests -- they no longer indicate "assuming A5/1 is supported"
because classmark 1 is missing, because we now know the Classmark 1.
Rationale:
During Location Updating, we receive Classmark 1; during CM Service Request and
Paging Response, we receive Classmark 2. So far we stored these only for the
duration of the conn, so as soon as a LU is complete, we would forget CM1.
In other words, for anything else than a LU Request, we had no Classmark 1
available at all.
During Ciphering Mode Command, we rely on Classmark 1 to determine whether A5/1
is supported. That is moot if we don't even have a Classmark 1 for any CM
Service Request or Paging Response initiated connections.
The only reason that A5/1 worked is that we assume A5/1 to work if Classmark 1
is missing. To add to the confusion, if a phone indicated that it did *not*
support A5/1 in the Classmark 1, according to spec we're supposed to not
service it at all. A code comment however says that we instead want to heed the
flag -- which so far was only present in a Location Updating initiated
connection. Now we can make this decision without assuming things.
This got my attention while hacking on sending a BSSMAP Classmark Request from
the MSC if it finds missing Classmark information, and was surprised to see it
it lacking CM1 to decide about A5/1.
Change-Id: I27081bf6e9e017923b2d02607f7ea06beddad82a
diff --git a/src/libmsc/gsm_04_08.c b/src/libmsc/gsm_04_08.c
index 19b0572..b942a03 100644
--- a/src/libmsc/gsm_04_08.c
+++ b/src/libmsc/gsm_04_08.c
@@ -98,14 +98,25 @@
return gsm48_conn_sendmsg(msg, conn, NULL);
}
+static bool classmark1_is_r99(const struct gsm48_classmark1 *cm1)
+{
+ return cm1->rev_lev >= 2;
+}
+
+static bool classmark2_is_r99(const uint8_t *cm2, uint8_t cm2_len)
+{
+ uint8_t rev_lev;
+ if (!cm2_len)
+ return false;
+ rev_lev = (cm2[0] >> 5) & 0x3;
+ return rev_lev >= 2;
+}
+
static bool classmark_is_r99(struct gsm_classmark *cm)
{
- int rev_lev = 0;
if (cm->classmark1_set)
- rev_lev = cm->classmark1.rev_lev;
- else if (cm->classmark2_len > 0)
- rev_lev = (cm->classmark2[0] >> 5) & 0x3;
- return rev_lev >= 2;
+ return classmark1_is_r99(&cm->classmark1);
+ return classmark2_is_r99(cm->classmark2, cm->classmark2_len);
}
/* Determine if the given CLASSMARK (1/2/3) value permits a given A5/n cipher */
@@ -345,9 +356,6 @@
msc_subscr_conn_update_id(conn, COMPLETE_LAYER3_LU, mi_string);
- conn->classmark.classmark1 = lu->classmark1;
- conn->classmark.classmark1_set = true;
-
DEBUGP(DMM, "LOCATION UPDATING REQUEST: MI(%s)=%s type=%s\n",
gsm48_mi_type_name(mi_type), mi_string,
get_value_string(lupd_names, lu->type));
@@ -402,7 +410,7 @@
&old_lai, &new_lai,
is_utran || conn->network->authentication_required,
is_utran || conn->network->a5_encryption_mask > 0x01,
- classmark_is_r99(&conn->classmark),
+ classmark1_is_r99(&lu->classmark1),
is_utran,
net->vlr->cfg.assign_tmsi);
if (!lu_fsm) {
@@ -421,6 +429,9 @@
return -EIO;
}
+ conn->vsub->classmark.classmark1 = lu->classmark1;
+ conn->vsub->classmark.classmark1_set = true;
+
msc_subscr_conn_complete_layer_3(conn);
return 0;
}
@@ -773,8 +784,6 @@
msc_subscr_conn_update_id(conn, COMPLETE_LAYER3_CM_SERVICE_REQ, mi_string);
osmo_signal_dispatch(SS_SUBSCR, S_SUBSCR_IDENTITY, mi_p);
- memcpy(conn->classmark.classmark2, classmark2, classmark2_len);
- conn->classmark.classmark2_len = classmark2_len;
is_utran = (conn->via_ran == RAN_UTRAN_IU);
vlr_proc_acc_req(conn->fi,
@@ -783,9 +792,20 @@
VLR_PR_ARQ_T_CM_SERV_REQ, mi-1, &lai,
is_utran || conn->network->authentication_required,
is_utran || conn->network->a5_encryption_mask > 0x01,
- classmark_is_r99(&conn->classmark),
+ classmark2_is_r99(classmark2, classmark2_len),
is_utran);
+ /* From vlr_proc_acc_req() we expect an implicit dispatch of PR_ARQ_E_START we expect
+ * msc_vlr_subscr_assoc() to already have been called and completed. Has an error occured? */
+ if (!conn->vsub) {
+ LOGP(DRR, LOGL_ERROR, "%s: subscriber not allowed to do a CM Service Request\n",
+ mi_string);
+ return -EIO;
+ }
+
+ memcpy(conn->vsub->classmark.classmark2, classmark2, classmark2_len);
+ conn->vsub->classmark.classmark2_len = classmark2_len;
+
msc_subscr_conn_complete_layer_3(conn);
return 0;
}
@@ -846,11 +866,6 @@
break;
}
- /* TODO? We used to remember the subscriber's classmark1 here and
- * stored it in the old sqlite db, but now we store it in a conn that
- * will be discarded anyway: */
- conn->classmark.classmark1 = idi->classmark1;
-
if (!vsub) {
LOGP(DMM, LOGL_ERROR, "IMSI DETACH for unknown subscriber MI(%s)=%s\n",
gsm48_mi_type_name(mi_type), mi_string);
@@ -860,6 +875,9 @@
if (vsub->cs.is_paging)
subscr_paging_cancel(vsub, GSM_PAGING_EXPIRED);
+ /* We already got Classmark 1 during Location Updating ... but well, ok */
+ vsub->classmark.classmark1 = idi->classmark1;
+
vlr_subscr_rx_imsi_detach(vsub);
osmo_signal_dispatch(SS_SUBSCR, S_SUBSCR_DETACHED, vsub);
vlr_subscr_put(vsub);
@@ -986,7 +1004,7 @@
is_umts ? "UMTS" : "GSM", is_umts ? "res" : "sres",
osmo_hexdump_nospc(res, res_len));
- return vlr_subscr_rx_auth_resp(conn->vsub, classmark_is_r99(&conn->classmark),
+ return vlr_subscr_rx_auth_resp(conn->vsub, classmark_is_r99(&conn->vsub->classmark),
conn->via_ran == RAN_UTRAN_IU,
res, res_len);
}
@@ -1128,27 +1146,15 @@
return rc;
}
-static uint8_t *gsm48_cm2_get_mi(uint8_t *classmark2_lv, unsigned int tot_len)
-{
- /* Check the size for the classmark */
- if (tot_len < 1 + *classmark2_lv)
- return NULL;
-
- uint8_t *mi_lv = classmark2_lv + *classmark2_lv + 1;
- if (tot_len < 2 + *classmark2_lv + mi_lv[0])
- return NULL;
-
- return mi_lv;
-}
-
/* Receive a PAGING RESPONSE message from the MS */
static int gsm48_rx_rr_pag_resp(struct gsm_subscriber_connection *conn, struct msgb *msg)
{
struct gsm_network *net = conn->network;
struct gsm48_hdr *gh = msgb_l3(msg);
struct gsm48_pag_resp *resp;
- uint8_t *classmark2_lv = gh->data + 1;
- uint8_t *mi_lv;
+ uint8_t classmark2_len = gh->data[1];
+ uint8_t *classmark2 = gh->data+2;
+ uint8_t *mi_lv = classmark2 + classmark2_len;
uint8_t mi_type;
char mi_string[GSM48_MI_SIZE];
struct osmo_location_area_id lai;
@@ -1158,8 +1164,11 @@
lai.lac = conn->lac;
resp = (struct gsm48_pag_resp *) &gh->data[0];
- gsm48_paging_extract_mi(resp, msgb_l3len(msg) - sizeof(*gh),
- mi_string, &mi_type);
+
+ if (gsm48_paging_extract_mi(resp, msgb_l3len(msg) - sizeof(*gh), mi_string, &mi_type) <= 0) {
+ LOGP(DRR, LOGL_ERROR, "PAGING RESPONSE: invalid Mobile Identity\n");
+ return -EINVAL;
+ }
if (msc_subscr_conn_is_establishing_auth_ciph(conn)) {
LOGP(DMM, LOGL_ERROR,
@@ -1174,17 +1183,8 @@
DEBUGP(DRR, "PAGING RESPONSE: MI(%s)=%s\n", gsm48_mi_type_name(mi_type), mi_string);
- mi_lv = gsm48_cm2_get_mi(classmark2_lv, msgb_l3len(msg) - sizeof(*gh));
- if (!mi_lv) {
- LOGP(DRR, LOGL_ERROR, "PAGING RESPONSE: invalid Mobile Identity\n");
- return -1;
- }
-
msc_subscr_conn_update_id(conn, COMPLETE_LAYER3_PAGING_RESP, mi_string);
- memcpy(conn->classmark.classmark2, classmark2_lv+1, *classmark2_lv);
- conn->classmark.classmark2_len = *classmark2_lv;
-
is_utran = (conn->via_ran == RAN_UTRAN_IU);
vlr_proc_acc_req(conn->fi,
SUBSCR_CONN_E_ACCEPTED, SUBSCR_CONN_E_CN_CLOSE, NULL,
@@ -1192,9 +1192,20 @@
VLR_PR_ARQ_T_PAGING_RESP, mi_lv, &lai,
is_utran || conn->network->authentication_required,
is_utran || conn->network->a5_encryption_mask > 0x01,
- classmark_is_r99(&conn->classmark),
+ classmark2_is_r99(classmark2, classmark2_len),
is_utran);
+ /* From vlr_proc_acc_req() we expect an implicit dispatch of PR_ARQ_E_START we expect
+ * msc_vlr_subscr_assoc() to already have been called and completed. Has an error occured? */
+ if (!conn->vsub) {
+ LOGP(DRR, LOGL_ERROR, "%s: subscriber not allowed to do a Paging Response\n",
+ mi_string);
+ return -EIO;
+ }
+
+ memcpy(conn->vsub->classmark.classmark2, classmark2, classmark2_len);
+ conn->vsub->classmark.classmark2_len = classmark2_len;
+
msc_subscr_conn_complete_layer_3(conn);
return 0;
}
@@ -1390,10 +1401,10 @@
gh = msgb_l3(msg);
pdisc = gsm48_hdr_pdisc(gh);
- if (conn->classmark.classmark1_set && conn->classmark.classmark1.rev_lev < 2) {
- modulo = gsm0407_determine_nsd_ret_modulo_r98(pdisc, gh->msg_type, &n_sd);
- } else { /* R99 */
+ if (conn->vsub && classmark_is_r99(&conn->vsub->classmark)) {
modulo = gsm0407_determine_nsd_ret_modulo_r99(pdisc, gh->msg_type, &n_sd);
+ } else { /* pre R99 */
+ modulo = gsm0407_determine_nsd_ret_modulo_r98(pdisc, gh->msg_type, &n_sd);
}
if (modulo == 0)
return false;
@@ -1618,7 +1629,7 @@
for (i = 0; i < 8; i++) {
if (net->a5_encryption_mask & (1 << i) &&
- classmark_supports_a5(&conn->classmark, i))
+ classmark_supports_a5(&conn->vsub->classmark, i))
ei.perm_algo[j++] = vlr_ciph_to_gsm0808_alg_id(i);
}
ei.perm_algo_len = j;