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-rw-r--r--src/osmo-bsc_nat/bsc_nat_utils.c893
1 files changed, 893 insertions, 0 deletions
diff --git a/src/osmo-bsc_nat/bsc_nat_utils.c b/src/osmo-bsc_nat/bsc_nat_utils.c
new file mode 100644
index 00000000..cd294ccf
--- /dev/null
+++ b/src/osmo-bsc_nat/bsc_nat_utils.c
@@ -0,0 +1,893 @@
+
+/* BSC Multiplexer/NAT Utilities */
+
+/*
+ * (C) 2010 by Holger Hans Peter Freyther <zecke@selfish.org>
+ * (C) 2010 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_nat.h>
+#include <openbsc/bsc_nat_sccp.h>
+#include <openbsc/bsc_msc.h>
+#include <openbsc/gsm_data.h>
+#include <openbsc/debug.h>
+#include <openbsc/ipaccess.h>
+#include <openbsc/vty.h>
+
+#include <osmocore/linuxlist.h>
+#include <osmocore/talloc.h>
+#include <osmocore/gsm0808.h>
+
+#include <osmocore/protocol/gsm_08_08.h>
+
+#include <osmocom/sccp/sccp.h>
+
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <unistd.h>
+
+static const struct rate_ctr_desc bsc_cfg_ctr_description[] = {
+ [BCFG_CTR_SCCP_CONN] = { "sccp.conn", "SCCP Connections "},
+ [BCFG_CTR_SCCP_CALLS] = { "sccp.calls", "SCCP Assignment Commands "},
+ [BCFG_CTR_NET_RECONN] = { "net.reconnects", "Network reconnects "},
+ [BCFG_CTR_DROPPED_SCCP] = { "dropped.sccp", "Dropped SCCP connections."},
+ [BCFG_CTR_DROPPED_CALLS] = { "dropped.calls", "Dropped active calls. "},
+ [BCFG_CTR_REJECTED_CR] = { "rejected.cr", "Rejected CR due filter "},
+ [BCFG_CTR_REJECTED_MSG] = { "rejected.msg", "Rejected MSG due filter "},
+ [BCFG_CTR_ILL_PACKET] = { "rejected.ill", "Rejected due parse error "},
+ [BCFG_CTR_CON_TYPE_LU] = { "conn.lu", "Conn Location Update "},
+ [BCFG_CTR_CON_CMSERV_RQ] = { "conn.rq", "Conn CM Service Req "},
+ [BCFG_CTR_CON_PAG_RESP] = { "conn.pag", "Conn Paging Response "},
+ [BCFG_CTR_CON_SSA] = { "conn.ssa", "Conn USSD "},
+ [BCFG_CTR_CON_OTHER] = { "conn.other", "Conn Other "},
+};
+
+static const struct rate_ctr_group_desc bsc_cfg_ctrg_desc = {
+ .group_name_prefix = "nat.bsc",
+ .group_description = "NAT BSC Statistics",
+ .num_ctr = ARRAY_SIZE(bsc_cfg_ctr_description),
+ .ctr_desc = bsc_cfg_ctr_description,
+};
+
+static const struct rate_ctr_desc acc_list_ctr_description[] = {
+ [ACC_LIST_BSC_FILTER] = { "access-list.bsc-filter", "Rejected by rule for BSC"},
+ [ACC_LIST_NAT_FILTER] = { "access-list.nat-filter", "Rejected by rule for NAT"},
+};
+
+static const struct rate_ctr_group_desc bsc_cfg_acc_list_desc = {
+ .group_name_prefix = "nat.filter",
+ .group_description = "NAT Access-List Statistics",
+ .num_ctr = ARRAY_SIZE(acc_list_ctr_description),
+ .ctr_desc = acc_list_ctr_description,
+};
+
+struct bsc_nat *bsc_nat_alloc(void)
+{
+ struct bsc_nat *nat = talloc_zero(tall_bsc_ctx, struct bsc_nat);
+ if (!nat)
+ return NULL;
+
+ INIT_LLIST_HEAD(&nat->sccp_connections);
+ INIT_LLIST_HEAD(&nat->bsc_connections);
+ INIT_LLIST_HEAD(&nat->bsc_configs);
+ INIT_LLIST_HEAD(&nat->access_lists);
+
+ nat->stats.sccp.conn = counter_alloc("nat.sccp.conn");
+ nat->stats.sccp.calls = counter_alloc("nat.sccp.calls");
+ nat->stats.bsc.reconn = counter_alloc("nat.bsc.conn");
+ nat->stats.bsc.auth_fail = counter_alloc("nat.bsc.auth_fail");
+ nat->stats.msc.reconn = counter_alloc("nat.msc.conn");
+ nat->stats.ussd.reconn = counter_alloc("nat.ussd.conn");
+ nat->msc_ip = talloc_strdup(nat, "127.0.0.1");
+ nat->msc_port = 5000;
+ nat->auth_timeout = 2;
+ nat->ping_timeout = 20;
+ nat->pong_timeout = 5;
+ return nat;
+}
+
+void bsc_nat_set_msc_ip(struct bsc_nat *nat, const char *ip)
+{
+ bsc_replace_string(nat, &nat->msc_ip, ip);
+}
+
+struct bsc_connection *bsc_connection_alloc(struct bsc_nat *nat)
+{
+ struct bsc_connection *con = talloc_zero(nat, struct bsc_connection);
+ if (!con)
+ return NULL;
+
+ con->nat = nat;
+ write_queue_init(&con->write_queue, 100);
+ return con;
+}
+
+struct bsc_config *bsc_config_alloc(struct bsc_nat *nat, const char *token)
+{
+ struct bsc_config *conf = talloc_zero(nat, struct bsc_config);
+ if (!conf)
+ return NULL;
+
+ conf->token = talloc_strdup(conf, token);
+ conf->nr = nat->num_bsc;
+ conf->nat = nat;
+ conf->max_endpoints = 32;
+
+ INIT_LLIST_HEAD(&conf->lac_list);
+
+ llist_add_tail(&conf->entry, &nat->bsc_configs);
+ ++nat->num_bsc;
+
+ conf->stats.ctrg = rate_ctr_group_alloc(conf, &bsc_cfg_ctrg_desc, conf->nr);
+ if (!conf->stats.ctrg) {
+ talloc_free(conf);
+ return NULL;
+ }
+
+ return conf;
+}
+
+void bsc_config_free(struct bsc_config *cfg)
+{
+ rate_ctr_group_free(cfg->stats.ctrg);
+}
+
+void bsc_config_add_lac(struct bsc_config *cfg, int _lac)
+{
+ struct bsc_lac_entry *lac;
+
+ llist_for_each_entry(lac, &cfg->lac_list, entry)
+ if (lac->lac == _lac)
+ return;
+
+ lac = talloc_zero(cfg, struct bsc_lac_entry);
+ if (!lac) {
+ LOGP(DNAT, LOGL_ERROR, "Failed to allocate.\n");
+ return;
+ }
+
+ lac->lac = _lac;
+ llist_add_tail(&lac->entry, &cfg->lac_list);
+}
+
+void bsc_config_del_lac(struct bsc_config *cfg, int _lac)
+{
+ struct bsc_lac_entry *lac;
+
+ llist_for_each_entry(lac, &cfg->lac_list, entry)
+ if (lac->lac == _lac) {
+ llist_del(&lac->entry);
+ talloc_free(lac);
+ return;
+ }
+}
+
+int bsc_config_handles_lac(struct bsc_config *cfg, int lac_nr)
+{
+ struct bsc_lac_entry *entry;
+
+ llist_for_each_entry(entry, &cfg->lac_list, entry)
+ if (entry->lac == lac_nr)
+ return 1;
+
+ return 0;
+}
+
+void sccp_connection_destroy(struct sccp_connections *conn)
+{
+ LOGP(DNAT, LOGL_DEBUG, "Destroy 0x%x <-> 0x%x mapping for con %p\n",
+ sccp_src_ref_to_int(&conn->real_ref),
+ sccp_src_ref_to_int(&conn->patched_ref), conn->bsc);
+ bsc_mgcp_dlcx(conn);
+ llist_del(&conn->list_entry);
+ talloc_free(conn);
+}
+
+struct bsc_connection *bsc_nat_find_bsc(struct bsc_nat *nat, struct msgb *msg, int *lac_out)
+{
+ struct bsc_connection *bsc;
+ int data_length;
+ const uint8_t *data;
+ struct tlv_parsed tp;
+ int i = 0;
+
+ *lac_out = -1;
+
+ if (!msg->l3h || msgb_l3len(msg) < 3) {
+ LOGP(DNAT, LOGL_ERROR, "Paging message is too short.\n");
+ return NULL;
+ }
+
+ tlv_parse(&tp, gsm0808_att_tlvdef(), msg->l3h + 3, msgb_l3len(msg) - 3, 0, 0);
+ if (!TLVP_PRESENT(&tp, GSM0808_IE_CELL_IDENTIFIER_LIST)) {
+ LOGP(DNAT, LOGL_ERROR, "No CellIdentifier List inside paging msg.\n");
+ return NULL;
+ }
+
+ data_length = TLVP_LEN(&tp, GSM0808_IE_CELL_IDENTIFIER_LIST);
+ data = TLVP_VAL(&tp, GSM0808_IE_CELL_IDENTIFIER_LIST);
+
+ /* No need to try a different BSS */
+ if (data[0] == CELL_IDENT_BSS) {
+ return NULL;
+ } else if (data[0] != CELL_IDENT_LAC) {
+ LOGP(DNAT, LOGL_ERROR, "Unhandled cell ident discrminator: %d\n", data[0]);
+ return NULL;
+ }
+
+ /* Currently we only handle one BSC */
+ for (i = 1; i < data_length - 1; i += 2) {
+ unsigned int _lac = ntohs(*(unsigned int *) &data[i]);
+ *lac_out = _lac;
+ llist_for_each_entry(bsc, &nat->bsc_connections, list_entry) {
+ if (!bsc->cfg)
+ continue;
+ if (!bsc->authenticated)
+ continue;
+ if (!bsc_config_handles_lac(bsc->cfg, _lac))
+ continue;
+
+ return bsc;
+ }
+ }
+
+ return NULL;
+}
+
+int bsc_write_mgcp(struct bsc_connection *bsc, const uint8_t *data, unsigned int length)
+{
+ struct msgb *msg;
+
+ if (length > 4096 - 128) {
+ LOGP(DINP, LOGL_ERROR, "Can not send message of that size.\n");
+ return -1;
+ }
+
+ msg = msgb_alloc_headroom(4096, 128, "to-bsc");
+ if (!msg) {
+ LOGP(DINP, LOGL_ERROR, "Failed to allocate memory for BSC msg.\n");
+ return -1;
+ }
+
+ /* copy the data */
+ msg->l3h = msgb_put(msg, length);
+ memcpy(msg->l3h, data, length);
+
+ return bsc_write(bsc, msg, IPAC_PROTO_MGCP_OLD);
+}
+
+int bsc_write(struct bsc_connection *bsc, struct msgb *msg, int proto)
+{
+ return bsc_do_write(&bsc->write_queue, msg, proto);
+}
+
+int bsc_do_write(struct write_queue *queue, struct msgb *msg, int proto)
+{
+ /* prepend the header */
+ ipaccess_prepend_header(msg, proto);
+ return bsc_write_msg(queue, msg);
+}
+
+int bsc_write_msg(struct write_queue *queue, struct msgb *msg)
+{
+ if (write_queue_enqueue(queue, msg) != 0) {
+ LOGP(DINP, LOGL_ERROR, "Failed to enqueue the write.\n");
+ msgb_free(msg);
+ return -1;
+ }
+
+ return 0;
+}
+
+int bsc_nat_lst_check_allow(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_allow)
+ continue;
+ if (regexec(&entry->imsi_allow_re, mi_string, 0, NULL, 0) == 0)
+ return 0;
+ }
+
+ 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;
+
+ *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);
+
+ msg_type = hdr48->msg_type & 0xbf;
+ if (hdr48->proto_discr == 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 (hdr48->proto_discr == 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 (hdr48->proto_discr == 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)
+{
+ /* gsm_type is actually the size of the dtap */
+ *len = parsed->gsm_type;
+ if (*len < msgb_l3len(msg) - 3) {
+ LOGP(DNAT, LOGL_ERROR, "Not enough space for DTAP.\n");
+ return NULL;
+ }
+
+ if (*len < sizeof(struct gsm48_hdr)) {
+ LOGP(DNAT, LOGL_ERROR, "GSM48 header does not fit.\n");
+ return NULL;
+ }
+
+ msg->l4h = &msg->l3h[3];
+ 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;
+ 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;
+
+ msg_type = hdr48->msg_type & 0xbf;
+ if (hdr48->proto_discr == 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;
+ }
+}
+
+void bsc_parse_reg(void *ctx, regex_t *reg, char **imsi, int argc, const char **argv)
+{
+ if (*imsi) {
+ talloc_free(*imsi);
+ *imsi = NULL;
+ }
+ regfree(reg);
+
+ if (argc > 0) {
+ *imsi = talloc_strdup(ctx, argv[0]);
+ regcomp(reg, argv[0], 0);
+ }
+}
+
+static const char *con_types [] = {
+ [NAT_CON_TYPE_NONE] = "n/a",
+ [NAT_CON_TYPE_LU] = "Location Update",
+ [NAT_CON_TYPE_CM_SERV_REQ] = "CM Serv Req",
+ [NAT_CON_TYPE_PAG_RESP] = "Paging Response",
+ [NAT_CON_TYPE_SSA] = "Supplementar Service Activation",
+ [NAT_CON_TYPE_LOCAL_REJECT] = "Local Reject",
+ [NAT_CON_TYPE_OTHER] = "Other",
+};
+
+const char *bsc_con_type_to_string(int type)
+{
+ return con_types[type];
+}
+
+struct bsc_nat_acc_lst *bsc_nat_acc_lst_find(struct bsc_nat *nat, const char *name)
+{
+ struct bsc_nat_acc_lst *lst;
+
+ if (!name)
+ return NULL;
+
+ llist_for_each_entry(lst, &nat->access_lists, list)
+ if (strcmp(lst->name, name) == 0)
+ return lst;
+
+ return NULL;
+}
+
+struct bsc_nat_acc_lst *bsc_nat_acc_lst_get(struct bsc_nat *nat, const char *name)
+{
+ struct bsc_nat_acc_lst *lst;
+
+ lst = bsc_nat_acc_lst_find(nat, name);
+ if (lst)
+ return lst;
+
+ lst = talloc_zero(nat, struct bsc_nat_acc_lst);
+ if (!lst) {
+ LOGP(DNAT, LOGL_ERROR, "Failed to allocate access list");
+ return NULL;
+ }
+
+ /* TODO: get the index right */
+ lst->stats = rate_ctr_group_alloc(lst, &bsc_cfg_acc_list_desc, 0);
+ if (!lst->stats) {
+ talloc_free(lst);
+ return NULL;
+ }
+
+ INIT_LLIST_HEAD(&lst->fltr_list);
+ lst->name = talloc_strdup(lst, name);
+ llist_add_tail(&lst->list, &nat->access_lists);
+ return lst;
+}
+
+void bsc_nat_acc_lst_delete(struct bsc_nat_acc_lst *lst)
+{
+ llist_del(&lst->list);
+ rate_ctr_group_free(lst->stats);
+ talloc_free(lst);
+}
+
+struct bsc_nat_acc_lst_entry *bsc_nat_acc_lst_entry_create(struct bsc_nat_acc_lst *lst)
+{
+ struct bsc_nat_acc_lst_entry *entry;
+
+ entry = talloc_zero(lst, struct bsc_nat_acc_lst_entry);
+ if (!entry)
+ return NULL;
+
+ llist_add_tail(&entry->list, &lst->fltr_list);
+ return entry;
+}
+
+int bsc_nat_msc_is_connected(struct bsc_nat *nat)
+{
+ return nat->msc_con->is_connected;
+}
+
+static const int con_to_ctr[] = {
+ [NAT_CON_TYPE_NONE] = -1,
+ [NAT_CON_TYPE_LU] = BCFG_CTR_CON_TYPE_LU,
+ [NAT_CON_TYPE_CM_SERV_REQ] = BCFG_CTR_CON_CMSERV_RQ,
+ [NAT_CON_TYPE_PAG_RESP] = BCFG_CTR_CON_PAG_RESP,
+ [NAT_CON_TYPE_SSA] = BCFG_CTR_CON_SSA,
+ [NAT_CON_TYPE_LOCAL_REJECT] = -1,
+ [NAT_CON_TYPE_OTHER] = BCFG_CTR_CON_OTHER,
+};
+
+int bsc_conn_type_to_ctr(struct sccp_connections *conn)
+{
+ return con_to_ctr[conn->con_type];
+}
+
+int bsc_write_cb(struct bsc_fd *bfd, struct msgb *msg)
+{
+ int rc;
+
+ rc = write(bfd->fd, msg->data, msg->len);
+ if (rc != msg->len)
+ LOGP(DNAT, LOGL_ERROR, "Failed to write message to the BSC.\n");
+
+ return rc;
+}
+
+/**
+ * Rewrite non global numbers... according to rules based on the IMSI
+ */
+struct msgb *bsc_nat_rewrite_setup(struct bsc_nat *nat, struct msgb *msg, struct bsc_nat_parsed *parsed, const char *imsi)
+{
+ struct tlv_parsed tp;
+ struct gsm48_hdr *hdr48;
+ uint32_t len;
+ uint8_t msg_type;
+ unsigned int payload_len;
+ struct gsm_mncc_number called;
+ struct msg_entry *entry;
+ char *new_number = NULL;
+ struct msgb *out, *sccp;
+ uint8_t *outptr;
+ const uint8_t *msgptr;
+ int sec_len;
+
+ if (!imsi || strlen(imsi) < 5)
+ return msg;
+
+ if (!nat->num_rewr)
+ return msg;
+
+ /* only care about DTAP messages */
+ if (parsed->bssap != BSSAP_MSG_DTAP)
+ return msg;
+ if (!parsed->dest_local_ref)
+ return msg;
+
+ hdr48 = bsc_unpack_dtap(parsed, msg, &len);
+ if (!hdr48)
+ return msg;
+
+ msg_type = hdr48->msg_type & 0xbf;
+ if (hdr48->proto_discr != GSM48_PDISC_CC ||
+ msg_type != GSM48_MT_CC_SETUP)
+ return msg;
+
+ /* decode and rewrite the message */
+ payload_len = len - sizeof(*hdr48);
+ tlv_parse(&tp, &gsm48_att_tlvdef, hdr48->data, payload_len, 0, 0);
+
+ /* no number, well let us ignore it */
+ if (!TLVP_PRESENT(&tp, GSM48_IE_CALLED_BCD))
+ return msg;
+
+ memset(&called, 0, sizeof(called));
+ gsm48_decode_called(&called,
+ TLVP_VAL(&tp, GSM48_IE_CALLED_BCD) - 1);
+
+ /* check if it looks international and stop */
+ if (called.plan != 1)
+ return msg;
+ if (called.type == 1)
+ return msg;
+ if (strncmp(called.number, "00", 2) == 0)
+ return msg;
+
+ /* need to find a replacement and then fix it */
+ llist_for_each_entry(entry, &nat->num_rewr->entry, list) {
+ regex_t reg;
+ regmatch_t matches[2];
+
+ if (entry->mcc[0] != '*' && strncmp(entry->mcc, imsi, 3) != 0)
+ continue;
+ if (entry->mnc[0] != '*' && strncmp(entry->mnc, imsi + 3, 2) != 0)
+ continue;
+
+ if (entry->text[0] == '+') {
+ LOGP(DNAT, LOGL_ERROR,
+ "Plus is not allowed in the number");
+ continue;
+ }
+
+ /* We have an entry for the IMSI. Need to match now */
+ if (regcomp(&reg, entry->option, REG_EXTENDED) != 0) {
+ LOGP(DNAT, LOGL_ERROR,
+ "Regexp '%s' is not valid.\n", entry->option);
+ continue;
+ }
+
+ /* this regexp matches... */
+ if (regexec(&reg, called.number, 2, matches, 0) == 0 &&
+ matches[1].rm_eo != -1)
+ new_number = talloc_asprintf(msg, "%s%s",
+ entry->text,
+ &called.number[matches[1].rm_so]);
+ regfree(&reg);
+
+ if (new_number)
+ break;
+ }
+
+ if (!new_number) {
+ LOGP(DNAT, LOGL_DEBUG, "No IMSI match found, returning message.\n");
+ return msg;
+ }
+
+ if (strlen(new_number) > sizeof(called.number)) {
+ LOGP(DNAT, LOGL_ERROR, "Number is too long for structure.\n");
+ talloc_free(new_number);
+ return msg;
+ }
+
+ /*
+ * Need to create a new message now based on the old onew
+ * with a new number. We can sadly not patch this in place
+ * so we will need to regenerate it.
+ */
+
+ out = msgb_alloc_headroom(4096, 128, "changed-setup");
+ if (!out) {
+ LOGP(DNAT, LOGL_ERROR, "Failed to allocate.\n");
+ talloc_free(new_number);
+ return msg;
+ }
+
+ /* copy the header */
+ outptr = msgb_put(out, sizeof(*hdr48));
+ memcpy(outptr, hdr48, sizeof(*hdr48));
+
+ /* copy everything up to the number */
+ sec_len = TLVP_VAL(&tp, GSM48_IE_CALLED_BCD) - 2 - &hdr48->data[0];
+ outptr = msgb_put(out, sec_len);
+ memcpy(outptr, &hdr48->data[0], sec_len);
+
+ /* create the new number */
+ if (strncmp(new_number, "00", 2) == 0) {
+ called.type = 1;
+ strncpy(called.number, new_number + 2, sizeof(called.number));
+ } else {
+ strncpy(called.number, new_number, sizeof(called.number));
+ }
+ gsm48_encode_called(out, &called);
+
+ /* copy thre rest */
+ msgptr = TLVP_VAL(&tp, GSM48_IE_CALLED_BCD) +
+ TLVP_LEN(&tp, GSM48_IE_CALLED_BCD);
+ sec_len = payload_len - (msgptr - &hdr48->data[0]);
+ outptr = msgb_put(out, sec_len);
+ memcpy(outptr, msgptr, sec_len);
+
+ /* wrap with DTAP, SCCP, then IPA. TODO: Stop copying */
+ gsm0808_prepend_dtap_header(out, 0);
+ sccp = sccp_create_dt1(parsed->dest_local_ref, out->data, out->len);
+ if (!sccp) {
+ LOGP(DNAT, LOGL_ERROR, "Failed to allocate.\n");
+ talloc_free(new_number);
+ talloc_free(out);
+ return msg;
+ }
+
+ ipaccess_prepend_header(sccp, IPAC_PROTO_SCCP);
+
+ /* give up memory, we are done */
+ talloc_free(new_number);
+ /* the parsed hangs off from msg but it needs to survive */
+ talloc_steal(sccp, parsed);
+ msgb_free(msg);
+ msgb_free(out);
+ out = NULL;
+ return sccp;
+}
+