From 986fe7ed18580775bed91399a1f02eae60bda251 Mon Sep 17 00:00:00 2001 From: Neels Hofmeyr Date: Thu, 13 Sep 2018 03:05:52 +0200 Subject: 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 --- src/libmsc/gsm_04_08.c | 109 +++++++++++++++++++++++++++---------------------- 1 file changed, 60 insertions(+), 49 deletions(-) (limited to 'src/libmsc/gsm_04_08.c') diff --git a/src/libmsc/gsm_04_08.c b/src/libmsc/gsm_04_08.c index 19b0572ee..b942a0391 100644 --- a/src/libmsc/gsm_04_08.c +++ b/src/libmsc/gsm_04_08.c @@ -98,14 +98,25 @@ int gsm48_tx_simple(struct gsm_subscriber_connection *conn, 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 @@ int mm_rx_loc_upd_req(struct gsm_subscriber_connection *conn, struct msgb *msg) 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 @@ int mm_rx_loc_upd_req(struct gsm_subscriber_connection *conn, struct msgb *msg) &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 @@ int mm_rx_loc_upd_req(struct gsm_subscriber_connection *conn, struct msgb *msg) 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 @@ int gsm48_rx_mm_serv_req(struct gsm_subscriber_connection *conn, struct msgb *ms 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 @@ int gsm48_rx_mm_serv_req(struct gsm_subscriber_connection *conn, struct msgb *ms 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 @@ static int gsm48_rx_mm_imsi_detach_ind(struct gsm_subscriber_connection *conn, s 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 @@ static int gsm48_rx_mm_imsi_detach_ind(struct gsm_subscriber_connection *conn, s 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 @@ static int gsm48_rx_mm_auth_resp(struct gsm_subscriber_connection *conn, struct 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 @@ static int gsm0408_rcv_mm(struct gsm_subscriber_connection *conn, struct msgb *m 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 @@ static int gsm48_rx_rr_pag_resp(struct gsm_subscriber_connection *conn, struct m 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 @@ static int gsm48_rx_rr_pag_resp(struct gsm_subscriber_connection *conn, struct m 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 @@ static int gsm48_rx_rr_pag_resp(struct gsm_subscriber_connection *conn, struct m 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 @@ static bool gsm0407_is_duplicate(struct gsm_subscriber_connection *conn, struct 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 @@ int msc_vlr_set_ciph_mode(void *msc_conn_ref, 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; -- cgit v1.2.3