From 24671f12b7aeac3d773dc6b423e2495c493215d4 Mon Sep 17 00:00:00 2001
From: juha-h <jh@tutpro.com>
Date: Tue, 21 May 2024 12:08:05 +0300
Subject: [PATCH] sip/transp: Allow ACK w/o Max-Forwards header (#1124)

---
 src/sip/transp.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/sip/transp.c b/src/sip/transp.c
index e62e9f18d..ea9e9d43c 100644
--- a/src/sip/transp.c
+++ b/src/sip/transp.c
@@ -314,7 +314,8 @@ static bool have_essential_fields(const struct sip_msg *msg)
 		pl_isset(&(msg->from.auri)) &&
 		pl_isset(&(msg->cseq.met)) &&
 		pl_isset(&(msg->callid)) &&
-		pl_isset(&(msg->maxfwd)) &&
+		(pl_isset(&(msg->maxfwd)) ||
+		 !pl_strncmp(&msg->met, "ACK", 3)) &&
 		pl_isset(&(msg->via.branch)))
 		return true;