Simplify up_session_choose_f_teid() with early returns

Change-Id: I6e8c64d093588157c86bb3acaaeed458ff73132d
---
M src/osmo-upf/up_session.c
1 file changed, 36 insertions(+), 33 deletions(-)


git pull ssh://gerrit.osmocom.org:29418/osmo-upf refs/changes/50/39450/1

diff --git a/src/osmo-upf/up_session.c b/src/osmo-upf/up_session.c
index 928db0b..c870358 100644
--- a/src/osmo-upf/up_session.c
+++ b/src/osmo-upf/up_session.c
@@ -185,43 +185,46 @@
 						     bool choose_id_present, uint8_t choose_id,
 						     const char *netinst_name)
 {
-	struct chosen_f_teid *chosen = NULL;
+	struct chosen_f_teid *chosen;
+	int rc;
 
-	if (choose_id_present)
+	if (choose_id_present) {
 		chosen = chosen_f_teid_find(&session->chosen_f_teids, choose_id);
-	if (chosen) {
-		/* Re-use a previous F-TEID */
-		*dst = chosen->f_teid;
-	} else {
-		int rc;
+		if (chosen) {
+			/* Re-use a previous F-TEID */
+			*dst = chosen->f_teid;
+			return OSMO_PFCP_CAUSE_REQUEST_ACCEPTED;
+		}
+		/* No previous F-TEID found, allocate a new one below */
+	}
 
-		*dst = (struct osmo_pfcp_ie_f_teid){
-			.choose_flag = false,
+	*dst = (struct osmo_pfcp_ie_f_teid){
+		.choose_flag = false,
+	};
+
+	/* Determine local IP address from Network Instance value received in PFCP request */
+	rc = up_session_choose_local_ip(session, &dst->fixed.ip_addr, netinst_name);
+	if (rc)
+		return rc;
+
+	/* Choose a new TEID */
+	dst->fixed.teid = upf_next_local_teid();
+	if (dst->fixed.teid == 0) {
+		LOGPFSML(session->fi, LOGL_ERROR, "Failed to allocate an unused TEID\n");
+		return OSMO_PFCP_CAUSE_PFCP_ENTITY_IN_CONGESTION;
+	}
+
+	LOGPFSML(session->fi, LOGL_INFO, "Allocated new local F-TEID %s\n",
+			osmo_pfcp_ie_f_teid_to_str_c(OTC_SELECT, dst));
+
+	/* Save this choice */
+	if (choose_id_present) {
+		chosen = talloc(session, struct chosen_f_teid);
+		*chosen = (struct chosen_f_teid){
+			.f_teid = *dst,
+			.choose_id = choose_id,
 		};
-
-		/* Determine local IP address from Network Instance value received in PFCP request */
-		rc = up_session_choose_local_ip(session, &dst->fixed.ip_addr, netinst_name);
-		if (rc)
-			return rc;
-
-		/* Choose a new TEID */
-		dst->fixed.teid = upf_next_local_teid();
-		if (dst->fixed.teid == 0) {
-			LOGPFSML(session->fi, LOGL_ERROR, "Failed to allocate an unused TEID\n");
-			return OSMO_PFCP_CAUSE_PFCP_ENTITY_IN_CONGESTION;
-		}
-		LOGPFSML(session->fi, LOGL_INFO, "Allocated new local F-TEID %s\n",
-			 osmo_pfcp_ie_f_teid_to_str_c(OTC_SELECT, dst));
-
-		/* Save this choice */
-		if (choose_id_present) {
-			chosen = talloc(session, struct chosen_f_teid);
-			*chosen = (struct chosen_f_teid){
-				.f_teid = *dst,
-				.choose_id = choose_id,
-			};
-			llist_add_tail(&chosen->entry, &session->chosen_f_teids);
-		}
+		llist_add_tail(&chosen->entry, &session->chosen_f_teids);
 	}
 	return OSMO_PFCP_CAUSE_REQUEST_ACCEPTED;
 }

