USSD: Add support for internal USSD handlers
There are some requests that are best served inside the HLR, as it
has access to subscriber information such as MSISDN and IMSI.
This unfortunately required quite some restructuring of the USSD
related structures including the VTY syntax for adding routes.
The default config file has been updated to replicate the *#100#
built-in behavior of old OsmoNITB.
Closes: OS#2566
Change-Id: I1d09fab810a6bb9ab02904de72dbc9e8a414f9f9
diff --git a/src/hlr_ussd.c b/src/hlr_ussd.c
index d23debf..f9399d2 100644
--- a/src/hlr_ussd.c
+++ b/src/hlr_ussd.c
@@ -27,6 +27,7 @@
#include <osmocom/gsm/protocol/gsm_04_80.h>
#include <stdint.h>
#include <string.h>
+#include <errno.h>
#include "hlr.h"
#include "hlr_ussd.h"
@@ -58,7 +59,6 @@
euse = talloc_zero(hlr, struct hlr_euse);
euse->name = talloc_strdup(euse, name);
euse->hlr = hlr;
- INIT_LLIST_HEAD(&euse->routes);
llist_add_tail(&euse->list, &hlr->euse_list);
return euse;
@@ -71,54 +71,68 @@
}
-struct hlr_euse_route *euse_route_find(struct hlr_euse *euse, const char *prefix)
+struct hlr_ussd_route *ussd_route_find_prefix(struct hlr *hlr, const char *prefix)
{
- struct hlr_euse_route *rt;
+ struct hlr_ussd_route *rt;
- llist_for_each_entry(rt, &euse->routes, list) {
+ llist_for_each_entry(rt, &hlr->ussd_routes, list) {
if (!strcmp(rt->prefix, prefix))
return rt;
}
return NULL;
}
-struct hlr_euse_route *euse_route_prefix_alloc(struct hlr_euse *euse, const char *prefix)
+struct hlr_ussd_route *ussd_route_prefix_alloc_int(struct hlr *hlr, const char *prefix,
+ const struct hlr_iuse *iuse)
{
- struct hlr_euse_route *rt;
+ struct hlr_ussd_route *rt;
- if (euse_route_find(euse, prefix))
+ if (ussd_route_find_prefix(hlr, prefix))
return NULL;
- rt = talloc_zero(euse, struct hlr_euse_route);
+ rt = talloc_zero(hlr, struct hlr_ussd_route);
rt->prefix = talloc_strdup(rt, prefix);
- rt->euse = euse;
- llist_add_tail(&rt->list, &euse->routes);
+ rt->u.iuse = iuse;
+ llist_add_tail(&rt->list, &hlr->ussd_routes);
return rt;
}
-void euse_route_del(struct hlr_euse_route *rt)
+struct hlr_ussd_route *ussd_route_prefix_alloc_ext(struct hlr *hlr, const char *prefix,
+ struct hlr_euse *euse)
+{
+ struct hlr_ussd_route *rt;
+
+ if (ussd_route_find_prefix(hlr, prefix))
+ return NULL;
+
+ rt = talloc_zero(hlr, struct hlr_ussd_route);
+ rt->prefix = talloc_strdup(rt, prefix);
+ rt->is_external = true;
+ rt->u.euse = euse;
+ llist_add_tail(&rt->list, &hlr->ussd_routes);
+
+ return rt;
+}
+
+void ussd_route_del(struct hlr_ussd_route *rt)
{
llist_del(&rt->list);
talloc_free(rt);
}
-struct hlr_euse *ussd_euse_find_7bit_gsm(struct hlr *hlr, const char *ussd_code)
+static struct hlr_ussd_route *ussd_route_lookup_7bit(struct hlr *hlr, const char *ussd_code)
{
- struct hlr_euse *euse;
-
- llist_for_each_entry(euse, &hlr->euse_list, list) {
- struct hlr_euse_route *rt;
- llist_for_each_entry(rt, &euse->routes, list) {
- if (!strncmp(ussd_code, rt->prefix, strlen(rt->prefix))) {
- LOGP(DSS, LOGL_DEBUG, "Found EUSE %s (prefix %s) for USSD Code '%s'\n",
- rt->euse->name, rt->prefix, ussd_code);
- return rt->euse;
- }
+ struct hlr_ussd_route *rt;
+ llist_for_each_entry(rt, &hlr->ussd_routes, list) {
+ if (!strncmp(ussd_code, rt->prefix, strlen(rt->prefix))) {
+ LOGP(DSS, LOGL_DEBUG, "Found EUSE %s (prefix %s) for USSD Code '%s'\n",
+ rt->u.euse->name, rt->prefix, ussd_code);
+ return rt;
}
}
- LOGP(DSS, LOGL_DEBUG, "Could not find Route/EUSE for USSD Code '%s'\n", ussd_code);
+ LOGP(DSS, LOGL_DEBUG, "Could not find Route for USSD Code '%s'\n", ussd_code);
return NULL;
}
@@ -141,8 +155,15 @@
/* time-out when we will delete the session */
struct osmo_timer_list timeout;
- /* external USSD Entity responsible for this session */
- struct hlr_euse *euse;
+ /* is this USSD for an external handler (EUSE): true */
+ bool is_external;
+ union {
+ /* external USSD Entity responsible for this session */
+ struct hlr_euse *euse;
+ /* internal USSD Entity responsible for this session */
+ const struct hlr_iuse *iuse;
+ } u;
+
/* we don't keep a pointer to the osmo_gsup_{route,conn} towards the MSC/VLR here,
* as this might change during inter-VLR hand-over, and we simply look-up the serving MSC/VLR
* every time we receive an USSD component from the EUSE */
@@ -247,6 +268,79 @@
return ss_tx_to_ms(ss, OSMO_GSUP_MSGT_PROC_SS_RESULT, true, msg);
}
+static int ss_tx_ussd_7bit(struct ss_session *ss, bool final, uint8_t invoke_id, const char *text)
+{
+ struct msgb *msg = gsm0480_gen_ussd_resp_7bit(invoke_id, text);
+ LOGPSS(ss, LOGL_INFO, "Tx USSD '%s'\n", text);
+ OSMO_ASSERT(msg);
+ return ss_tx_to_ms(ss, OSMO_GSUP_MSGT_PROC_SS_RESULT, final, msg);
+}
+
+/***********************************************************************
+ * Internal USSD Handlers
+ ***********************************************************************/
+
+#include "db.h"
+
+static int handle_ussd_own_msisdn(struct osmo_gsup_conn *conn, struct ss_session *ss,
+ const struct osmo_gsup_message *gsup, const struct ss_request *req)
+{
+ struct hlr_subscriber subscr;
+ char buf[GSM0480_USSD_7BIT_STRING_LEN+1];
+ int rc;
+
+ rc = db_subscr_get_by_imsi(g_hlr->dbc, ss->imsi, &subscr);
+ switch (rc) {
+ case 0:
+ if (strlen(subscr.msisdn) == 0)
+ snprintf(buf, sizeof(buf), "You have no MSISDN!");
+ else
+ snprintf(buf, sizeof(buf), "Your extension is %s\r", subscr.msisdn);
+ ss_tx_ussd_7bit(ss, true, req->invoke_id, buf);
+ break;
+ case -ENOENT:
+ ss_tx_error(ss, true, GSM0480_ERR_CODE_UNKNOWN_SUBSCRIBER);
+ break;
+ case -EIO:
+ default:
+ ss_tx_error(ss, true, GSM0480_ERR_CODE_SYSTEM_FAILURE);
+ break;
+ }
+ return 0;
+}
+
+static int handle_ussd_own_imsi(struct osmo_gsup_conn *conn, struct ss_session *ss,
+ const struct osmo_gsup_message *gsup, const struct ss_request *req)
+{
+ char buf[GSM0480_USSD_7BIT_STRING_LEN+1];
+ snprintf(buf, sizeof(buf), "Your IMSI is %s!\n", ss->imsi);
+ ss_tx_ussd_7bit(ss, true, req->invoke_id, buf);
+ return 0;
+}
+
+
+static const struct hlr_iuse hlr_iuses[] = {
+ {
+ .name = "own-msisdn",
+ .handle_ussd = handle_ussd_own_msisdn,
+ },
+ {
+ .name = "own-imsi",
+ .handle_ussd = handle_ussd_own_imsi,
+ },
+};
+
+const struct hlr_iuse *iuse_find(const char *name)
+{
+ unsigned int i;
+
+ for (i = 0; i < ARRAY_SIZE(hlr_iuses); i++) {
+ const struct hlr_iuse *iuse = &hlr_iuses[i];
+ if (!strcmp(name, iuse->name))
+ return iuse;
+ }
+ return NULL;
+}
/***********************************************************************
@@ -307,6 +401,7 @@
return 0;
}
+/* Handle a USSD GSUP message for a given SS Session received from VLR or EUSE */
static int handle_ussd(struct osmo_gsup_conn *conn, struct ss_session *ss,
const struct osmo_gsup_message *gsup, const struct ss_request *req)
{
@@ -318,8 +413,7 @@
gsm0480_comp_type_name(comp_type), gsm0480_op_code_name(req->opcode),
req->ussd_text);
-
- if (!ss->euse) {
+ if ((ss->is_external && !ss->u.euse) || !ss->u.iuse) {
LOGPSS(ss, LOGL_NOTICE, "USSD for unknown code '%s'\n", req->ussd_text);
ss_tx_error(ss, req->invoke_id, GSM0480_ERR_CODE_SS_NOT_AVAILABLE);
return 0;
@@ -333,19 +427,25 @@
/* FIXME: resolve this based on the database vlr_addr */
osmo_gsup_addr_send(conn->server, (uint8_t *)"MSC-00-00-00-00-00-00", 22, msg_out);
} else {
- /* Received from VLR, Forward to EUSE */
- char addr[128];
- strcpy(addr, "EUSE-");
- osmo_strlcpy(addr+5, ss->euse->name, sizeof(addr)-5);
- conn = gsup_route_find(conn->server, (uint8_t *)addr, strlen(addr)+1);
- if (!conn) {
- LOGPSS(ss, LOGL_ERROR, "Cannot find conn for EUSE %s\n", addr);
- ss_tx_error(ss, req->invoke_id, GSM0480_ERR_CODE_SYSTEM_FAILURE);
+ /* Received from VLR (MS) */
+ if (ss->is_external) {
+ /* Forward to EUSE */
+ char addr[128];
+ strcpy(addr, "EUSE-");
+ osmo_strlcpy(addr+5, ss->u.euse->name, sizeof(addr)-5);
+ conn = gsup_route_find(conn->server, (uint8_t *)addr, strlen(addr)+1);
+ if (!conn) {
+ LOGPSS(ss, LOGL_ERROR, "Cannot find conn for EUSE %s\n", addr);
+ ss_tx_error(ss, req->invoke_id, GSM0480_ERR_CODE_SYSTEM_FAILURE);
+ } else {
+ msg_out = msgb_alloc_headroom(1024+16, 16, "GSUP USSD FW");
+ OSMO_ASSERT(msg_out);
+ osmo_gsup_encode(msg_out, gsup);
+ osmo_gsup_conn_send(conn, msg_out);
+ }
} else {
- msg_out = msgb_alloc_headroom(1024+16, 16, "GSUP USSD FW");
- OSMO_ASSERT(msg_out);
- osmo_gsup_encode(msg_out, gsup);
- osmo_gsup_conn_send(conn, msg_out);
+ /* Handle internally */
+ ss->u.iuse->handle_ussd(conn, ss, gsup, req);
}
}
@@ -392,10 +492,20 @@
if (ss_op_is_ussd(req.opcode)) {
if (conn_is_euse(conn)) {
/* EUSE->VLR: MT USSD. EUSE is known ('conn'), VLR is to be resolved */
- ss->euse = euse_by_conn(conn);
+ ss->u.euse = euse_by_conn(conn);
} else {
/* VLR->EUSE: MO USSD. VLR is known ('conn'), EUSE is to be resolved */
- ss->euse = ussd_euse_find_7bit_gsm(hlr, (const char *) req.ussd_text);
+ struct hlr_ussd_route *rt;
+ rt = ussd_route_lookup_7bit(hlr, (const char *) req.ussd_text);
+ if (rt) {
+ if (rt->is_external) {
+ ss->is_external = true;
+ ss->u.euse = rt->u.euse;
+ } else if (rt) {
+ ss->is_external = false;
+ ss->u.iuse = rt->u.iuse;
+ }
+ }
}
/* dispatch unstructured SS to routing */
handle_ussd(conn, ss, gsup, &req);