diff options
Diffstat (limited to 'src/libfilter/bsc_msg_filter.c')
-rw-r--r-- | src/libfilter/bsc_msg_filter.c | 398 |
1 files changed, 0 insertions, 398 deletions
diff --git a/src/libfilter/bsc_msg_filter.c b/src/libfilter/bsc_msg_filter.c deleted file mode 100644 index 115d376cb..000000000 --- a/src/libfilter/bsc_msg_filter.c +++ /dev/null @@ -1,398 +0,0 @@ -/* - * Access filtering - */ -/* - * (C) 2010-2015 by Holger Hans Peter Freyther <zecke@selfish.org> - * (C) 2010-2012 by On-Waves - * All Rights Reserved - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU Affero General Public License as published by - * the Free Software Foundation; either version 3 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU Affero General Public License for more details. - * - * You should have received a copy of the GNU Affero General Public License - * along with this program. If not, see <http://www.gnu.org/licenses/>. - * - */ - -#include <openbsc/bsc_msg_filter.h> - -#include <openbsc/bsc_nat.h> -#include <openbsc/bsc_msc.h> -#include <openbsc/gsm_data.h> -#include <openbsc/debug.h> -#include <openbsc/ipaccess.h> - -#include <osmocom/core/talloc.h> -#include <osmocom/gsm/gsm0808.h> - -#include <osmocom/gsm/protocol/gsm_08_08.h> -#include <osmocom/gsm/protocol/gsm_04_11.h> - -int bsc_filter_barr_find(struct rb_root *root, const char *imsi, int *cm, int *lu) -{ - struct bsc_filter_barr_entry *n; - n = rb_entry(root->rb_node, struct bsc_filter_barr_entry, node); - - while (n) { - int rc = strcmp(imsi, n->imsi); - if (rc == 0) { - *cm = n->cm_reject_cause; - *lu = n->lu_reject_cause; - return 1; - } - - n = rb_entry( - (rc < 0) ? n->node.rb_left : n->node.rb_right, - struct bsc_filter_barr_entry, node); - }; - - return 0; -} - -static int insert_barr_node(struct bsc_filter_barr_entry *entry, struct rb_root *root) -{ - struct rb_node **new = &root->rb_node, *parent = NULL; - - while (*new) { - int rc; - struct bsc_filter_barr_entry *this; - this = rb_entry(*new, struct bsc_filter_barr_entry, node); - parent = *new; - - rc = strcmp(entry->imsi, this->imsi); - if (rc < 0) - new = &((*new)->rb_left); - else if (rc > 0) - new = &((*new)->rb_right); - else { - LOGP(DFILTER, LOGL_ERROR, - "Duplicate entry for IMSI(%s)\n", entry->imsi); - talloc_free(entry); - return -1; - } - } - - rb_link_node(&entry->node, parent, new); - rb_insert_color(&entry->node, root); - return 0; -} - -int bsc_filter_barr_adapt(void *ctx, struct rb_root *root, - const struct osmo_config_list *list) -{ - struct osmo_config_entry *cfg_entry; - int err = 0; - - /* free the old data */ - while (!RB_EMPTY_ROOT(root)) { - struct rb_node *node = rb_first(root); - rb_erase(node, root); - talloc_free(node); - } - - if (!list) - return 0; - - /* now adapt the new list */ - llist_for_each_entry(cfg_entry, &list->entry, list) { - struct bsc_filter_barr_entry *entry; - entry = talloc_zero(ctx, struct bsc_filter_barr_entry); - if (!entry) { - LOGP(DFILTER, LOGL_ERROR, - "Allocation of the barr entry failed.\n"); - continue; - } - - entry->imsi = talloc_strdup(entry, cfg_entry->mcc); - entry->cm_reject_cause = atoi(cfg_entry->mnc); - entry->lu_reject_cause = atoi(cfg_entry->option); - err |= insert_barr_node(entry, root); - } - - return err; -} - - -static int lst_check_deny(struct bsc_msg_acc_lst *lst, const char *mi_string, - int *cm_cause, int *lu_cause) -{ - struct bsc_msg_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) { - *cm_cause = entry->cm_reject_cause; - *lu_cause = entry->lu_reject_cause; - return 0; - } - } - - return 1; -} - -/* apply white/black list */ -static int auth_imsi(struct bsc_filter_request *req, - const char *imsi, - struct bsc_filter_reject_cause *cause) -{ - /* - * Now apply blacklist/whitelist of the BSC and the NAT. - * 1.) Check the global IMSI barr list - * 2.) Allow directly if the IMSI is allowed at the BSC - * 3.) Reject if the IMSI is not allowed at the BSC - * 4.) Reject if the IMSI not allowed at the global level. - * 5.) Allow directly if the IMSI is allowed at the global level - */ - int cm, lu; - struct bsc_msg_acc_lst *nat_lst = NULL; - struct bsc_msg_acc_lst *bsc_lst = NULL; - - /* 1. global check for barred imsis */ - if (req->black_list && bsc_filter_barr_find(req->black_list, imsi, &cm, &lu)) { - cause->cm_reject_cause = cm; - cause->lu_reject_cause = lu; - LOGP(DFILTER, LOGL_DEBUG, - "Blocking subscriber IMSI %s with CM: %d LU: %d\n", - imsi, cm, lu); - return -4; - } - - - bsc_lst = bsc_msg_acc_lst_find(req->access_lists, req->local_lst_name); - nat_lst = bsc_msg_acc_lst_find(req->access_lists, req->global_lst_name); - - - if (bsc_lst) { - /* 2. BSC allow */ - if (bsc_msg_acc_lst_check_allow(bsc_lst, imsi) == 0) - return 1; - - /* 3. BSC deny */ - if (lst_check_deny(bsc_lst, imsi, &cm, &lu) == 0) { - LOGP(DFILTER, LOGL_ERROR, - "Filtering %s by imsi_deny on config nr: %d.\n", imsi, req->bsc_nr); - rate_ctr_inc(&bsc_lst->stats->ctr[ACC_LIST_LOCAL_FILTER]); - cause->cm_reject_cause = cm; - cause->lu_reject_cause = lu; - return -2; - } - - } - - /* 4. NAT deny */ - if (nat_lst) { - if (lst_check_deny(nat_lst, imsi, &cm, &lu) == 0) { - LOGP(DFILTER, LOGL_ERROR, - "Filtering %s global imsi_deny on bsc nr: %d.\n", imsi, req->bsc_nr); - rate_ctr_inc(&nat_lst->stats->ctr[ACC_LIST_GLOBAL_FILTER]); - cause->cm_reject_cause = cm; - cause->lu_reject_cause = lu; - return -3; - } - } - - return 1; -} - -static int _cr_check_loc_upd(void *ctx, - 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(DFILTER, 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(ctx, mi_string); - return 1; -} - -static int _cr_check_cm_serv_req(void *ctx, - 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(DFILTER, 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 = FLT_CON_TYPE_SSA; - rc = gsm48_extract_mi((uint8_t *) &req->classmark, - length - classmark_offset, mi_string, &mi_type); - if (rc < 0) { - LOGP(DFILTER, 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(ctx, mi_string); - return 1; -} - -static int _cr_check_pag_resp(void *ctx, - 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(DFILTER, 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(DFILTER, 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(ctx, mi_string); - return 1; -} - -static int _dt_check_id_resp(struct bsc_filter_request *req, - uint8_t *data, unsigned int length, - struct bsc_filter_state *state, - struct bsc_filter_reject_cause *cause) -{ - char mi_string[GSM48_MI_SIZE]; - uint8_t mi_type; - - if (length < 2) { - LOGP(DFILTER, LOGL_ERROR, "mi does not fit.\n"); - return -1; - } - - if (data[0] < length - 1) { - LOGP(DFILTER, 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; - - state->imsi_checked = 1; - state->imsi = talloc_strdup(req->ctx, mi_string); - return auth_imsi(req, mi_string, cause); -} - - -/* Filter out CR data... */ -int bsc_msg_filter_initial(struct gsm48_hdr *hdr48, size_t hdr48_len, - struct bsc_filter_request *req, - int *con_type, - char **imsi, struct bsc_filter_reject_cause *cause) -{ - int ret = 0; - uint8_t msg_type, proto; - - *con_type = FLT_CON_TYPE_NONE; - cause->cm_reject_cause = GSM48_REJECT_PLMN_NOT_ALLOWED; - cause->lu_reject_cause = GSM48_REJECT_PLMN_NOT_ALLOWED; - *imsi = NULL; - - proto = gsm48_hdr_pdisc(hdr48); - msg_type = gsm48_hdr_msg_type(hdr48); - if (proto == GSM48_PDISC_MM && - msg_type == GSM48_MT_MM_LOC_UPD_REQUEST) { - *con_type = FLT_CON_TYPE_LU; - ret = _cr_check_loc_upd(req->ctx, &hdr48->data[0], - hdr48_len - sizeof(*hdr48), imsi); - } else if (proto == GSM48_PDISC_MM && - msg_type == GSM48_MT_MM_CM_SERV_REQ) { - *con_type = FLT_CON_TYPE_CM_SERV_REQ; - ret = _cr_check_cm_serv_req(req->ctx, &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 = FLT_CON_TYPE_PAG_RESP; - ret = _cr_check_pag_resp(req->ctx, &hdr48->data[0], - hdr48_len - sizeof(*hdr48), imsi); - } else { - /* We only want to filter the above, let other things pass */ - *con_type = FLT_CON_TYPE_OTHER; - return 0; - } - - /* check if we are done */ - if (ret != 1) - return ret; - - /* the memory allocation failed */ - if (!*imsi) - return -1; - - /* now check the imsi */ - return auth_imsi(req, *imsi, cause); -} - -int bsc_msg_filter_data(struct gsm48_hdr *hdr48, size_t len, - struct bsc_filter_request *req, - struct bsc_filter_state *state, - struct bsc_filter_reject_cause *cause) -{ - uint8_t msg_type, proto; - - cause->cm_reject_cause = GSM48_REJECT_PLMN_NOT_ALLOWED; - cause->lu_reject_cause = GSM48_REJECT_PLMN_NOT_ALLOWED; - - if (state->imsi_checked) - return 0; - - proto = gsm48_hdr_pdisc(hdr48); - msg_type = gsm48_hdr_msg_type(hdr48); - if (proto != GSM48_PDISC_MM || msg_type != GSM48_MT_MM_ID_RESP) - return 0; - - return _dt_check_id_resp(req, &hdr48->data[0], - len - sizeof(*hdr48), state, cause); -} |