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authorHolger Hans Peter Freyther <zecke@selfish.org>2010-09-15 19:00:53 +0800
committerHolger Hans Peter Freyther <zecke@selfish.org>2010-09-15 19:00:53 +0800
commita594342f71e835d0316a3ee655a6c1a58679e1b4 (patch)
tree3b2eb213c518ea3434c5f7f60a46246fcce1e79f
parent5f54075a8be6e041c8fbf56ff6281fc78a6d7929 (diff)
parent09ecda49d7e12412d50e85109e3f3dc81d76927f (diff)
Merge branch 'zecke/imsi-filter'
-rw-r--r--openbsc/include/openbsc/bsc_nat.h2
-rw-r--r--openbsc/include/openbsc/bsc_nat_sccp.h1
-rw-r--r--openbsc/src/nat/bsc_nat.c88
-rw-r--r--openbsc/src/nat/bsc_nat_utils.c79
-rw-r--r--openbsc/tests/bsc-nat/bsc_data.c8
-rw-r--r--openbsc/tests/bsc-nat/bsc_nat_test.c64
6 files changed, 223 insertions, 19 deletions
diff --git a/openbsc/include/openbsc/bsc_nat.h b/openbsc/include/openbsc/bsc_nat.h
index 0c9af9184..6b2a09940 100644
--- a/openbsc/include/openbsc/bsc_nat.h
+++ b/openbsc/include/openbsc/bsc_nat.h
@@ -243,6 +243,8 @@ struct bsc_connection *bsc_nat_find_bsc(struct bsc_nat *nat, struct msgb *msg, i
*/
int bsc_nat_filter_sccp_cr(struct bsc_connection *bsc, struct msgb *msg,
struct bsc_nat_parsed *, int *con_type);
+int bsc_nat_filter_dt(struct bsc_connection *bsc, struct msgb *msg,
+ struct sccp_connections *con, struct bsc_nat_parsed *parsed);
/**
* SCCP patching and handling
diff --git a/openbsc/include/openbsc/bsc_nat_sccp.h b/openbsc/include/openbsc/bsc_nat_sccp.h
index 4f1afcb2b..c4f756e3d 100644
--- a/openbsc/include/openbsc/bsc_nat_sccp.h
+++ b/openbsc/include/openbsc/bsc_nat_sccp.h
@@ -78,6 +78,7 @@ struct sccp_connections {
/* status */
int con_type;
int con_local;
+ int imsi_checked;
/*
* audio handling. Remember if we have ever send a CRCX,
diff --git a/openbsc/src/nat/bsc_nat.c b/openbsc/src/nat/bsc_nat.c
index 6485102df..738b7ef39 100644
--- a/openbsc/src/nat/bsc_nat.c
+++ b/openbsc/src/nat/bsc_nat.c
@@ -303,6 +303,63 @@ static void bsc_send_data(struct bsc_connection *bsc, const uint8_t *data, unsig
bsc_write(bsc, msg, proto);
}
+/*
+ * Release an established connection. We will have to release it to the BSC
+ * and to the network and we do it the following way.
+ * 1.) Give up on the MSC side
+ * 1.1) Send a RLSD message, it is a bit non standard but should work, we
+ * ignore the RLC... we might complain about it. Other options would
+ * be to send a Release Request, handle the Release Complete..
+ * 1.2) Mark the data structure to be con_local and wait for 2nd
+ *
+ * 2.) Give up on the BSC side
+ * 2.1) Depending on the con type reject the service, or just close it
+ */
+static void bsc_send_con_release(struct bsc_connection *bsc, struct sccp_connections *con)
+{
+ struct msgb *rlsd;
+ /* 1. release the network */
+ rlsd = sccp_create_rlsd(&con->patched_ref, &con->remote_ref,
+ SCCP_RELEASE_CAUSE_END_USER_ORIGINATED);
+ if (!rlsd)
+ LOGP(DNAT, LOGL_ERROR, "Failed to create RLSD message.\n");
+ else {
+ ipaccess_prepend_header(rlsd, IPAC_PROTO_SCCP);
+ queue_for_msc(con->msc_con, rlsd);
+ }
+ con->con_local = 1;
+
+ /* 2. release the BSC side */
+ if (con->con_type == NAT_CON_TYPE_LU) {
+ struct msgb *payload, *udt;
+ payload = gsm48_create_loc_upd_rej(GSM48_REJECT_PLMN_NOT_ALLOWED);
+
+ if (payload) {
+ gsm0808_prepend_dtap_header(payload, 0);
+ udt = sccp_create_dt1(&con->real_ref, payload->data, payload->len);
+ if (udt)
+ bsc_write(bsc, udt, IPAC_PROTO_SCCP);
+ else
+ LOGP(DNAT, LOGL_ERROR, "Failed to create DT1\n");
+
+ msgb_free(payload);
+ } else {
+ LOGP(DNAT, LOGL_ERROR, "Failed to allocate LU Reject.\n");
+ }
+ }
+
+ rlsd = sccp_create_rlsd(&con->remote_ref, &con->real_ref,
+ SCCP_RELEASE_CAUSE_END_USER_ORIGINATED);
+ if (!rlsd) {
+ LOGP(DNAT, LOGL_ERROR, "Failed to allocate RLSD for the BSC.\n");
+ sccp_connection_destroy(con);
+ return;
+ }
+
+ con->con_type = NAT_CON_TYPE_LOCAL_REJECT;
+ bsc_write(bsc, rlsd, IPAC_PROTO_SCCP);
+}
+
static void bsc_send_con_refuse(struct bsc_connection *bsc,
struct bsc_nat_parsed *parsed, int con_type)
{
@@ -708,10 +765,12 @@ static int forward_sccp_to_msc(struct bsc_connection *bsc, struct msgb *msg)
/* modify the SCCP entries */
if (parsed->ipa_proto == IPAC_PROTO_SCCP) {
+ int filter;
struct sccp_connections *con;
switch (parsed->sccp_type) {
case SCCP_MSG_TYPE_CR:
- if (bsc_nat_filter_sccp_cr(bsc, msg, parsed, &con_type) != 0)
+ filter = bsc_nat_filter_sccp_cr(bsc, msg, parsed, &con_type);
+ if (filter < 0)
goto exit3;
if (!create_sccp_src_ref(bsc, parsed))
goto exit2;
@@ -719,6 +778,7 @@ static int forward_sccp_to_msc(struct bsc_connection *bsc, struct msgb *msg)
con->msc_con = bsc->nat->msc_con;
con_msc = con->msc_con;
con->con_type = con_type;
+ con->imsi_checked = filter;
con_bsc = con->bsc;
break;
case SCCP_MSG_TYPE_RLSD:
@@ -728,9 +788,16 @@ static int forward_sccp_to_msc(struct bsc_connection *bsc, struct msgb *msg)
case SCCP_MSG_TYPE_IT:
con = patch_sccp_src_ref_to_msc(msg, parsed, bsc);
if (con) {
- con_bsc = con->bsc;
- con_msc = con->msc_con;
- con_filter = con->con_local;
+ filter = bsc_nat_filter_dt(bsc, msg, con, parsed);
+ if (filter == 0) {
+ con_bsc = con->bsc;
+ con_msc = con->msc_con;
+ con_filter = con->con_local;
+ } else {
+ bsc_send_con_release(bsc, con);
+ con = NULL;
+ goto exit2;
+ }
}
break;
case SCCP_MSG_TYPE_RLC:
@@ -766,15 +833,18 @@ static int forward_sccp_to_msc(struct bsc_connection *bsc, struct msgb *msg)
goto exit2;
}
- if (!con_msc) {
- LOGP(DNAT, LOGL_ERROR, "No connection found, dropping data.\n");
- goto exit2;
- }
-
/* do not forward messages to the MSC */
if (con_filter)
goto exit2;
+ if (!con_msc) {
+ LOGP(DNAT, LOGL_ERROR, "Not forwarding data bsc_nr: %d ipa: %d type: 0x%x\n",
+ bsc->cfg->nr,
+ parsed ? parsed->ipa_proto : -1,
+ parsed ? parsed->sccp_type : -1);
+ goto exit2;
+ }
+
/* send the non-filtered but maybe modified msg */
queue_for_msc(con_msc, msg);
talloc_free(parsed);
diff --git a/openbsc/src/nat/bsc_nat_utils.c b/openbsc/src/nat/bsc_nat_utils.c
index 058251368..3933f1bf4 100644
--- a/openbsc/src/nat/bsc_nat_utils.c
+++ b/openbsc/src/nat/bsc_nat_utils.c
@@ -271,7 +271,7 @@ static int auth_imsi(struct bsc_connection *bsc, const char *mi_string)
/* 2. BSC allow */
if (lst_check_allow(bsc_lst, mi_string) == 0)
- return 0;
+ return 1;
}
/* 3. NAT deny */
@@ -283,7 +283,7 @@ static int auth_imsi(struct bsc_connection *bsc, const char *mi_string)
}
}
- return 0;
+ return 1;
}
static int _cr_check_loc_upd(struct bsc_connection *bsc, uint8_t *data, unsigned int length)
@@ -369,6 +369,35 @@ static int _cr_check_pag_resp(struct bsc_connection *bsc, uint8_t *data, unsigne
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;
+ 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)
{
@@ -376,6 +405,7 @@ int bsc_nat_filter_sccp_cr(struct bsc_connection *bsc, struct msgb *msg, struct
struct gsm48_hdr *hdr48;
int hdr48_len;
int len;
+ uint8_t msg_type;
*con_type = NAT_CON_TYPE_NONE;
@@ -412,16 +442,17 @@ int bsc_nat_filter_sccp_cr(struct bsc_connection *bsc, struct msgb *msg, struct
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 &&
- hdr48->msg_type == GSM48_MT_MM_LOC_UPD_REQUEST) {
+ 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));
} else if (hdr48->proto_discr == GSM48_PDISC_MM &&
- hdr48->msg_type == GSM48_MT_MM_CM_SERV_REQ) {
+ 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));
} else if (hdr48->proto_discr == GSM48_PDISC_RR &&
- hdr48->msg_type == GSM48_MT_RR_PAG_RESP) {
+ 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));
} else {
@@ -431,6 +462,44 @@ int bsc_nat_filter_sccp_cr(struct bsc_connection *bsc, struct msgb *msg, struct
}
}
+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;
+
+ /* 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 -1;
+ }
+
+ if (len < sizeof(*hdr48)) {
+ LOGP(DNAT, LOGL_ERROR, "GSM48 header does not fit.\n");
+ return -1;
+ }
+
+ msg->l4h = &msg->l3h[3];
+ hdr48 = (struct gsm48_hdr *) msg->l4h;
+
+ 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) {
diff --git a/openbsc/tests/bsc-nat/bsc_data.c b/openbsc/tests/bsc-nat/bsc_data.c
index a3239799c..1bc15c873 100644
--- a/openbsc/tests/bsc-nat/bsc_data.c
+++ b/openbsc/tests/bsc-nat/bsc_data.c
@@ -88,6 +88,14 @@ static const uint8_t ass_cmd[] = {
0x01, 0x0b, 0x03, 0x01, 0x0a, 0x11, 0x01, 0x00,
0x15 };
+/* identity response */
+static const uint8_t id_resp[] = {
+0x00, 0x15, 0xfd, 0x06, 0x01, 0x1c, 0xdc,
+0x00, 0x01, 0x0e, 0x01, 0x00, 0x0b, 0x05, 0x59,
+0x08, 0x29, 0x40, 0x21, 0x03, 0x07, 0x48, 0x66,
+0x31
+};
+
/*
* MGCP messages
*/
diff --git a/openbsc/tests/bsc-nat/bsc_nat_test.c b/openbsc/tests/bsc-nat/bsc_nat_test.c
index 8f4e2d152..926c97cd7 100644
--- a/openbsc/tests/bsc-nat/bsc_nat_test.c
+++ b/openbsc/tests/bsc-nat/bsc_nat_test.c
@@ -31,6 +31,7 @@
#include <osmocore/talloc.h>
#include <osmocom/sccp/sccp.h>
+#include <osmocore/protocol/gsm_08_08.h>
#include <stdio.h>
@@ -582,19 +583,19 @@ static struct cr_filter cr_filter[] = {
{
.data = bssmap_cr,
.length = sizeof(bssmap_cr),
- .result = 0,
+ .result = 1,
.contype = NAT_CON_TYPE_CM_SERV_REQ,
},
{
.data = bss_lu,
.length = sizeof(bss_lu),
- .result = 0,
+ .result = 1,
.contype = NAT_CON_TYPE_LU,
},
{
.data = pag_resp,
.length = sizeof(pag_resp),
- .result = 0,
+ .result = 1,
.contype = NAT_CON_TYPE_PAG_RESP,
},
{
@@ -609,7 +610,7 @@ static struct cr_filter cr_filter[] = {
/* BSC allow is before NAT deny */
.data = bss_lu,
.length = sizeof(bss_lu),
- .result = 0,
+ .result = 1,
.nat_imsi_deny = "[0-9]*",
.bsc_imsi_allow = "2440[0-9]*",
.contype = NAT_CON_TYPE_LU,
@@ -618,7 +619,7 @@ static struct cr_filter cr_filter[] = {
/* BSC allow is before NAT deny */
.data = bss_lu,
.length = sizeof(bss_lu),
- .result = 0,
+ .result = 1,
.bsc_imsi_allow = "[0-9]*",
.nat_imsi_deny = "[0-9]*",
.contype = NAT_CON_TYPE_LU,
@@ -696,6 +697,58 @@ static void test_cr_filter()
msgb_free(msg);
}
+static void test_dt_filter()
+{
+ int i;
+ struct msgb *msg = msgb_alloc(4096, "test_dt_filter");
+ struct bsc_nat_parsed *parsed;
+
+ struct bsc_nat *nat = bsc_nat_alloc();
+ struct bsc_connection *bsc = bsc_connection_alloc(nat);
+ struct sccp_connections *con = talloc_zero(0, struct sccp_connections);
+
+ bsc->cfg = bsc_config_alloc(nat, "foo", 23);
+ con->bsc = bsc;
+
+ msgb_reset(msg);
+ copy_to_msg(msg, id_resp, ARRAY_SIZE(id_resp));
+
+ parsed = bsc_nat_parse(msg);
+ if (!parsed) {
+ fprintf(stderr, "FAIL: Could not parse ID resp\n");
+ abort();
+ }
+
+ if (parsed->bssap != BSSAP_MSG_DTAP) {
+ fprintf(stderr, "FAIL: It should be dtap\n");
+ abort();
+ }
+
+ /* gsm_type is actually the size of the dtap */
+ if (parsed->gsm_type < msgb_l3len(msg) - 3) {
+ fprintf(stderr, "FAIL: Not enough space for the content\n");
+ abort();
+ }
+
+ if (bsc_nat_filter_dt(bsc, msg, con, parsed) != 1) {
+ fprintf(stderr, "FAIL: Should have passed..\n");
+ abort();
+ }
+
+ /* just some basic length checking... */
+ for (i = ARRAY_SIZE(id_resp); i >= 0; --i) {
+ msgb_reset(msg);
+ copy_to_msg(msg, id_resp, ARRAY_SIZE(id_resp));
+
+ parsed = bsc_nat_parse(msg);
+ if (!parsed)
+ continue;
+
+ con->imsi_checked = 0;
+ bsc_nat_filter_dt(bsc, msg, con, parsed);
+ }
+}
+
int main(int argc, char **argv)
{
struct log_target *stderr_target;
@@ -714,6 +767,7 @@ int main(int argc, char **argv)
test_mgcp_rewrite();
test_mgcp_parse();
test_cr_filter();
+ test_dt_filter();
return 0;
}