diff options
author | Holger Hans Peter Freyther <zecke@selfish.org> | 2012-12-17 13:32:53 +0100 |
---|---|---|
committer | Holger Hans Peter Freyther <zecke@selfish.org> | 2013-01-07 15:02:34 +0100 |
commit | adc2e8737235fd5f1655ba1a319d3aab76f16d91 (patch) | |
tree | d39ee5ce70ab4a208340eaca76fc8029f1105a44 /openbsc/src/osmo-bsc_nat/bsc_nat_utils.c | |
parent | 6fbd864a65981af00c0e7a8479d2b5cbbf129abd (diff) |
nat: Move the IMSI/TMSI filtering to a new and dedicated file
Move all routines related to filtering to a separate file.
Diffstat (limited to 'openbsc/src/osmo-bsc_nat/bsc_nat_utils.c')
-rw-r--r-- | openbsc/src/osmo-bsc_nat/bsc_nat_utils.c | 281 |
1 files changed, 0 insertions, 281 deletions
diff --git a/openbsc/src/osmo-bsc_nat/bsc_nat_utils.c b/openbsc/src/osmo-bsc_nat/bsc_nat_utils.c index c1c233bfa..0c56a8cd9 100644 --- a/openbsc/src/osmo-bsc_nat/bsc_nat_utils.c +++ b/openbsc/src/osmo-bsc_nat/bsc_nat_utils.c @@ -374,259 +374,6 @@ int bsc_nat_lst_check_allow(struct bsc_nat_acc_lst *lst, const char *mi_string) return 1; } -static int lst_check_deny(struct bsc_nat_acc_lst *lst, const char *mi_string) -{ - struct bsc_nat_acc_lst_entry *entry; - - llist_for_each_entry(entry, &lst->fltr_list, list) { - if (!entry->imsi_deny) - continue; - if (regexec(&entry->imsi_deny_re, mi_string, 0, NULL, 0) == 0) - return 0; - } - - return 1; -} - -/* apply white/black list */ -static int auth_imsi(struct bsc_connection *bsc, const char *mi_string) -{ - /* - * Now apply blacklist/whitelist of the BSC and the NAT. - * 1.) Allow directly if the IMSI is allowed at the BSC - * 2.) Reject if the IMSI is not allowed at the BSC - * 3.) Reject if the IMSI not allowed at the global level. - * 4.) Allow directly if the IMSI is allowed at the global level - */ - struct bsc_nat_acc_lst *nat_lst = NULL; - struct bsc_nat_acc_lst *bsc_lst = NULL; - - bsc_lst = bsc_nat_acc_lst_find(bsc->nat, bsc->cfg->acc_lst_name); - nat_lst = bsc_nat_acc_lst_find(bsc->nat, bsc->nat->acc_lst_name); - - - if (bsc_lst) { - /* 1. BSC allow */ - if (bsc_nat_lst_check_allow(bsc_lst, mi_string) == 0) - return 1; - - /* 2. BSC deny */ - if (lst_check_deny(bsc_lst, mi_string) == 0) { - LOGP(DNAT, LOGL_ERROR, - "Filtering %s by imsi_deny on bsc nr: %d.\n", mi_string, bsc->cfg->nr); - rate_ctr_inc(&bsc_lst->stats->ctr[ACC_LIST_BSC_FILTER]); - return -2; - } - - } - - /* 3. NAT deny */ - if (nat_lst) { - if (lst_check_deny(nat_lst, mi_string) == 0) { - LOGP(DNAT, LOGL_ERROR, - "Filtering %s by nat imsi_deny on bsc nr: %d.\n", mi_string, bsc->cfg->nr); - rate_ctr_inc(&nat_lst->stats->ctr[ACC_LIST_NAT_FILTER]); - return -3; - } - } - - return 1; -} - -static int _cr_check_loc_upd(struct bsc_connection *bsc, - uint8_t *data, unsigned int length, - char **imsi) -{ - uint8_t mi_type; - struct gsm48_loc_upd_req *lu; - char mi_string[GSM48_MI_SIZE]; - - if (length < sizeof(*lu)) { - LOGP(DNAT, LOGL_ERROR, - "LU does not fit. Length is %d \n", length); - return -1; - } - - lu = (struct gsm48_loc_upd_req *) data; - mi_type = lu->mi[0] & GSM_MI_TYPE_MASK; - - /* - * We can only deal with the IMSI. This will fail for a phone that - * will send the TMSI of a previous network to us. - */ - if (mi_type != GSM_MI_TYPE_IMSI) - return 0; - - gsm48_mi_to_string(mi_string, sizeof(mi_string), lu->mi, lu->mi_len); - *imsi = talloc_strdup(bsc, mi_string); - return auth_imsi(bsc, mi_string); -} - -static int _cr_check_cm_serv_req(struct bsc_connection *bsc, - uint8_t *data, unsigned int length, - int *con_type, char **imsi) -{ - static const uint32_t classmark_offset = - offsetof(struct gsm48_service_request, classmark); - - char mi_string[GSM48_MI_SIZE]; - uint8_t mi_type; - int rc; - struct gsm48_service_request *req; - - /* unfortunately in Phase1 the classmark2 length is variable */ - - if (length < sizeof(*req)) { - LOGP(DNAT, LOGL_ERROR, - "CM Serv Req does not fit. Length is %d\n", length); - return -1; - } - - req = (struct gsm48_service_request *) data; - if (req->cm_service_type == 0x8) - *con_type = NAT_CON_TYPE_SSA; - rc = gsm48_extract_mi((uint8_t *) &req->classmark, - length - classmark_offset, mi_string, &mi_type); - if (rc < 0) { - LOGP(DNAT, LOGL_ERROR, "Failed to parse the classmark2/mi. error: %d\n", rc); - return -1; - } - - /* we have to let the TMSI or such pass */ - if (mi_type != GSM_MI_TYPE_IMSI) - return 0; - - *imsi = talloc_strdup(bsc, mi_string); - return auth_imsi(bsc, mi_string); -} - -static int _cr_check_pag_resp(struct bsc_connection *bsc, - uint8_t *data, unsigned int length, - char **imsi) -{ - struct gsm48_pag_resp *resp; - char mi_string[GSM48_MI_SIZE]; - uint8_t mi_type; - - if (length < sizeof(*resp)) { - LOGP(DNAT, LOGL_ERROR, "PAG RESP does not fit. Length was %d.\n", length); - return -1; - } - - resp = (struct gsm48_pag_resp *) data; - if (gsm48_paging_extract_mi(resp, length, mi_string, &mi_type) < 0) { - LOGP(DNAT, LOGL_ERROR, "Failed to extract the MI.\n"); - return -1; - } - - /* we need to let it pass for now */ - if (mi_type != GSM_MI_TYPE_IMSI) - return 0; - - *imsi = talloc_strdup(bsc, mi_string); - return auth_imsi(bsc, mi_string); -} - -static int _dt_check_id_resp(struct bsc_connection *bsc, - uint8_t *data, unsigned int length, - struct sccp_connections *con) -{ - char mi_string[GSM48_MI_SIZE]; - uint8_t mi_type; - int ret; - - if (length < 2) { - LOGP(DNAT, LOGL_ERROR, "mi does not fit.\n"); - return -1; - } - - if (data[0] < length - 1) { - LOGP(DNAT, LOGL_ERROR, "mi length too big.\n"); - return -2; - } - - mi_type = data[1] & GSM_MI_TYPE_MASK; - gsm48_mi_to_string(mi_string, sizeof(mi_string), &data[1], data[0]); - - if (mi_type != GSM_MI_TYPE_IMSI) - return 0; - - ret = auth_imsi(bsc, mi_string); - con->imsi_checked = 1; - con->imsi = talloc_strdup(con, mi_string); - return ret; -} - -/* Filter out CR data... */ -int bsc_nat_filter_sccp_cr(struct bsc_connection *bsc, struct msgb *msg, - struct bsc_nat_parsed *parsed, int *con_type, - char **imsi) -{ - struct tlv_parsed tp; - struct gsm48_hdr *hdr48; - int hdr48_len; - int len; - uint8_t msg_type, proto; - - *con_type = NAT_CON_TYPE_NONE; - *imsi = NULL; - - if (parsed->gsm_type != BSS_MAP_MSG_COMPLETE_LAYER_3) { - LOGP(DNAT, LOGL_ERROR, - "Rejecting CR message due wrong GSM Type %d\n", parsed->gsm_type); - return -1; - } - - /* the parsed has had some basic l3 length check */ - len = msg->l3h[1]; - if (msgb_l3len(msg) - 3 < len) { - LOGP(DNAT, LOGL_ERROR, - "The CR Data has not enough space...\n"); - return -1; - } - - msg->l4h = &msg->l3h[3]; - len -= 1; - - tlv_parse(&tp, gsm0808_att_tlvdef(), msg->l4h, len, 0, 0); - - if (!TLVP_PRESENT(&tp, GSM0808_IE_LAYER_3_INFORMATION)) { - LOGP(DNAT, LOGL_ERROR, "CR Data does not contain layer3 information.\n"); - return -1; - } - - hdr48_len = TLVP_LEN(&tp, GSM0808_IE_LAYER_3_INFORMATION); - - if (hdr48_len < sizeof(*hdr48)) { - LOGP(DNAT, LOGL_ERROR, "GSM48 header does not fit.\n"); - return -1; - } - - hdr48 = (struct gsm48_hdr *) TLVP_VAL(&tp, GSM0808_IE_LAYER_3_INFORMATION); - - proto = hdr48->proto_discr & 0x0f; - msg_type = hdr48->msg_type & 0xbf; - if (proto == GSM48_PDISC_MM && - msg_type == GSM48_MT_MM_LOC_UPD_REQUEST) { - *con_type = NAT_CON_TYPE_LU; - return _cr_check_loc_upd(bsc, &hdr48->data[0], hdr48_len - sizeof(*hdr48), imsi); - } else if (proto == GSM48_PDISC_MM && - msg_type == GSM48_MT_MM_CM_SERV_REQ) { - *con_type = NAT_CON_TYPE_CM_SERV_REQ; - return _cr_check_cm_serv_req(bsc, &hdr48->data[0], - hdr48_len - sizeof(*hdr48), - con_type, imsi); - } else if (proto == GSM48_PDISC_RR && - msg_type == GSM48_MT_RR_PAG_RESP) { - *con_type = NAT_CON_TYPE_PAG_RESP; - return _cr_check_pag_resp(bsc, &hdr48->data[0], hdr48_len - sizeof(*hdr48), imsi); - } else { - /* We only want to filter the above, let other things pass */ - *con_type = NAT_CON_TYPE_OTHER; - return 0; - } -} - struct gsm48_hdr *bsc_unpack_dtap(struct bsc_nat_parsed *parsed, struct msgb *msg, uint32_t *len) { @@ -648,34 +395,6 @@ struct gsm48_hdr *bsc_unpack_dtap(struct bsc_nat_parsed *parsed, return (struct gsm48_hdr *) msg->l4h; } -int bsc_nat_filter_dt(struct bsc_connection *bsc, struct msgb *msg, - struct sccp_connections *con, struct bsc_nat_parsed *parsed) -{ - uint32_t len; - uint8_t msg_type, proto; - struct gsm48_hdr *hdr48; - - if (con->imsi_checked) - return 0; - - /* only care about DTAP messages */ - if (parsed->bssap != BSSAP_MSG_DTAP) - return 0; - - hdr48 = bsc_unpack_dtap(parsed, msg, &len); - if (!hdr48) - return -1; - - proto = hdr48->proto_discr & 0x0f; - msg_type = hdr48->msg_type & 0xbf; - if (proto == GSM48_PDISC_MM && - msg_type == GSM48_MT_MM_ID_RESP) { - return _dt_check_id_resp(bsc, &hdr48->data[0], len - sizeof(*hdr48), con); - } else { - return 0; - } -} - static const char *con_types [] = { [NAT_CON_TYPE_NONE] = "n/a", [NAT_CON_TYPE_LU] = "Location Update", |