Change in osmo-hlr[master]: USSD: fix handle_ussd(): do not free() unconditionally

[laforge]

laforge has submitted this change. ( https://gerrit.osmocom.org/c/osmo-hlr/+/21182 )

Change subject: USSD: fix handle_ussd(): do not free() unconditionally
......................................................................

USSD: fix handle_ussd(): do not free() unconditionally

An internal handler may want to continue session, e.g. to request
more information from the MS.  Let's make the handlers responsible
for session state management, and check that state before calling
ss_session_free(), so a session can remain alive.

Before this patch ss->state was not set/used at all...

Change-Id: I49262e7fe26f29dedbf126087cfb8f3bb3c548dc
---
M src/hlr_ussd.c
1 file changed, 23 insertions(+), 16 deletions(-)

Approvals:
  Jenkins Builder: Verified
  laforge: Looks good to me, approved



diff --git a/src/hlr_ussd.c b/src/hlr_ussd.c
index 25e9354..399bdbc 100644
--- a/src/hlr_ussd.c
+++ b/src/hlr_ussd.c
@@ -279,19 +279,20 @@
 }
 
 static int ss_tx_to_ms(struct ss_session *ss, enum osmo_gsup_message_type gsup_msg_type,
-			bool final, struct msgb *ss_msg)
+		       struct msgb *ss_msg)
 
 {
-	struct osmo_gsup_message resp = {0};
+	struct osmo_gsup_message resp;
 	int rc;
 
-	resp.message_type = gsup_msg_type;
+	resp = (struct osmo_gsup_message) {
+		.message_type = gsup_msg_type,
+		.session_id = ss->session_id,
+		.session_state = ss->state,
+	};
+
 	OSMO_STRLCPY_ARRAY(resp.imsi, ss->imsi);
-	if (final)
-		resp.session_state = OSMO_GSUP_SESSION_STATE_END;
-	else
-		resp.session_state = OSMO_GSUP_SESSION_STATE_CONTINUE;
-	resp.session_id = ss->session_id;
+
 	if (ss_msg) {
 		resp.ss_info = msgb_data(ss_msg);
 		resp.ss_info_len = msgb_length(ss_msg);
@@ -311,7 +312,8 @@
 	LOGPSS(ss, LOGL_NOTICE, "Tx Reject(%u, 0x%02x, 0x%02x)\n", invoke_id,
 		problem_tag, problem_code);
 	OSMO_ASSERT(msg);
-	return ss_tx_to_ms(ss, OSMO_GSUP_MSGT_PROC_SS_RESULT, true, msg);
+	ss->state = OSMO_GSUP_SESSION_STATE_END;
+	return ss_tx_to_ms(ss, OSMO_GSUP_MSGT_PROC_SS_RESULT, msg);
 }
 #endif
 
@@ -320,15 +322,16 @@
 	struct msgb *msg = gsm0480_gen_return_error(invoke_id, error_code);
 	LOGPSS(ss, LOGL_NOTICE, "Tx ReturnError(%u, 0x%02x)\n", invoke_id, error_code);
 	OSMO_ASSERT(msg);
-	return ss_tx_to_ms(ss, OSMO_GSUP_MSGT_PROC_SS_RESULT, true, msg);
+	ss->state = OSMO_GSUP_SESSION_STATE_END;
+	return ss_tx_to_ms(ss, OSMO_GSUP_MSGT_PROC_SS_RESULT, msg);
 }
 
-static int ss_tx_to_ms_ussd_7bit(struct ss_session *ss, bool final, uint8_t invoke_id, const char *text)
+static int ss_tx_to_ms_ussd_7bit(struct ss_session *ss, 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);
+	return ss_tx_to_ms(ss, OSMO_GSUP_MSGT_PROC_SS_RESULT, msg);
 }
 
 /***********************************************************************
@@ -344,6 +347,8 @@
 	char buf[GSM0480_USSD_7BIT_STRING_LEN+1];
 	int rc;
 
+	ss->state = OSMO_GSUP_SESSION_STATE_END;
+
 	rc = db_subscr_get_by_imsi(g_hlr->dbc, ss->imsi, &subscr);
 	switch (rc) {
 	case 0:
@@ -351,7 +356,7 @@
 			snprintf(buf, sizeof(buf), "You have no MSISDN!");
 		else
 			snprintf(buf, sizeof(buf), "Your extension is %s", subscr.msisdn);
-		ss_tx_to_ms_ussd_7bit(ss, true, req->invoke_id, buf);
+		ss_tx_to_ms_ussd_7bit(ss, req->invoke_id, buf);
 		break;
 	case -ENOENT:
 		ss_tx_to_ms_error(ss, req->invoke_id, GSM0480_ERR_CODE_UNKNOWN_SUBSCRIBER);
@@ -369,7 +374,8 @@
 {
 	char buf[GSM0480_USSD_7BIT_STRING_LEN+1];
 	snprintf(buf, sizeof(buf), "Your IMSI is %s", ss->imsi);
-	ss_tx_to_ms_ussd_7bit(ss, true, req->invoke_id, buf);
+	ss->state = OSMO_GSUP_SESSION_STATE_END;
+	ss_tx_to_ms_ussd_7bit(ss, req->invoke_id, buf);
 	return 0;
 }
 
@@ -496,8 +502,9 @@
 		} else {
 			/* Handle internally */
 			ss->u.iuse->handle_ussd(ss, gsup, req);
-			/* Release session immediately */
-			ss_session_free(ss);
+			/* Release session if the handler has changed its state to END */
+			if (ss->state == OSMO_GSUP_SESSION_STATE_END)
+				ss_session_free(ss);
 		}
 	}
 

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Gerrit-Project: osmo-hlr
Gerrit-Branch: master
Gerrit-Change-Id: I49262e7fe26f29dedbf126087cfb8f3bb3c548dc
Gerrit-Change-Number: 21182
Gerrit-PatchSet: 3
Gerrit-Owner: fixeria <vyanitskiy at sysmocom.de>
Gerrit-Reviewer: Jenkins Builder
Gerrit-Reviewer: laforge <laforge at osmocom.org>
Gerrit-MessageType: merged
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