From f6db77da4439334b276f20d6ff7ed64d301d67ef Mon Sep 17 00:00:00 2001
From: Weiqi Wang <wq.wang@mail.utoronto.ca>
Date: Thu, 24 Jun 2021 20:38:57 +0800
Subject: [PATCH] sip/transp: add essential fields check (#119)

---
 src/sip/transp.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/src/sip/transp.c b/src/sip/transp.c
index cc7d88daf..0567cf7df 100644
--- a/src/sip/transp.c
+++ b/src/sip/transp.c
@@ -279,6 +279,18 @@ static void conn_keepalive_handler(void *arg)
 		  conn_keepalive_handler, conn);
 }
 
+static bool have_essential_fields(const struct sip_msg *msg)
+{
+	if (pl_isset(&(msg->to.auri)) &&
+		pl_isset(&(msg->from.auri)) &&
+		pl_isset(&(msg->cseq.met)) &&
+		pl_isset(&(msg->callid)) &&
+		pl_isset(&(msg->maxfwd)) &&
+		pl_isset(&(msg->via.branch)))
+		return true;
+
+	return false;
+}
 
 static void sip_recv(struct sip *sip, const struct sip_msg *msg,
 		     size_t start)
@@ -291,6 +303,13 @@ static void sip_recv(struct sip *sip, const struct sip_msg *msg,
 			    sip->arg);
 	}
 
+	if (msg->req) {
+		if (!have_essential_fields(msg)){
+			(void)sip_reply(sip, msg, 400, "Bad Request");
+			return;
+		}
+	}
+
 	while (le) {
 		struct sip_lsnr *lsnr = le->data;