From 019136712de0ca37f7b5f324819b6ed2aa37685e Mon Sep 17 00:00:00 2001
From: Christian Spielberger <c.spielberger@commend.com>
Date: Fri, 28 May 2021 11:08:48 +0200
Subject: [PATCH] sip: copy the IPv6 scope ID from laddr to dst

---
 src/sip/transp.c | 55 ++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 48 insertions(+), 7 deletions(-)

diff --git a/src/sip/transp.c b/src/sip/transp.c
index cc7d88daf..b1cc1c14d 100644
--- a/src/sip/transp.c
+++ b/src/sip/transp.c
@@ -26,6 +26,11 @@
 #include "sip.h"
 
 
+#define DEBUG_MODULE "transp"
+#define DEBUG_LEVEL 5
+#include <re_dbg.h>
+
+
 enum {
 	TCP_ACCEPT_TIMEOUT    = 32,
 	TCP_IDLE_TIMEOUT      = 900,
@@ -157,6 +162,9 @@ static const struct sip_transport *transp_find(struct sip *sip,
 		if (af != AF_UNSPEC && sa_af(&transp->laddr) != af)
 			continue;
 
+		if (sa_is_linklocal(&transp->laddr) != sa_is_linklocal(dst))
+			continue;
+
 		return transp;
 	}
 
@@ -371,6 +379,12 @@ static void udp_recv_handler(const struct sa *src, struct mbuf *mb, void *arg)
 	msg->src = *src;
 	msg->dst = transp->laddr;
 	msg->tp = SIP_TRANSP_UDP;
+	sa_set_scopeid(&msg->src, sa_scopeid(&transp->laddr));
+
+	if (err) {
+		DEBUG_WARNING("could not copy IPv6 scope id from %j to %j\n",
+				&transp->laddr, &msg->src);
+	}
 
 	sip_recv(transp->sip, msg, 0);
 
@@ -1009,6 +1023,25 @@ static int ws_conn_send(struct sip_connqent **qentp, struct sip *sip,
 }
 
 
+#if HAVE_INET6
+static int dst_set_scopeid(struct sip *sip, struct sa *dst, enum sip_transp tp)
+{
+	struct sa laddr;
+	int err;
+
+	if (sa_af(dst) != AF_INET6 || !sa_is_linklocal(dst))
+		return 0;
+
+	err = sip_transp_laddr(sip, &laddr, tp, dst);
+	if (err)
+		return err;
+
+	sa_set_scopeid(dst, sa_scopeid(&laddr));
+	return 0;
+}
+#endif
+
+
 int sip_transp_init(struct sip *sip, uint32_t sz)
 {
 	return hash_alloc(&sip->ht_conn, sz);
@@ -1323,25 +1356,33 @@ int sip_transp_send(struct sip_connqent **qentp, struct sip *sip, void *sock,
 	const struct sip_transport *transp;
 	struct sip_conn *conn;
 	bool secure = false;
+	struct sa dsttmp;
 	int err;
 
 	if (!sip || !dst || !mb)
 		return EINVAL;
 
+	sa_cpy(&dsttmp, dst);
+#if HAVE_INET6
+	err = dst_set_scopeid(sip, &dsttmp, tp);
+	if (err)
+		return err;
+#endif
+
 	switch (tp) {
 
 	case SIP_TRANSP_UDP:
 		if (!sock) {
-			transp = transp_find(sip, tp, sa_af(dst), dst);
+			transp = transp_find(sip, tp, sa_af(&dsttmp), &dsttmp);
 			if (!transp)
 				return EPROTONOSUPPORT;
 
 			sock = transp->sock;
 		}
 
-		trace_send(sip, tp, sock, dst, mb);
+		trace_send(sip, tp, sock, &dsttmp, mb);
 
-		err = udp_send(sock, dst, mb);
+		err = udp_send(sock, &dsttmp, mb);
 		break;
 
 	case SIP_TRANSP_TLS:
@@ -1353,12 +1394,12 @@ int sip_transp_send(struct sip_connqent **qentp, struct sip *sip, void *sock,
 
 		if (conn && conn->tc) {
 
-			trace_send(sip, tp, conn, dst, mb);
+			trace_send(sip, tp, conn, &dsttmp, mb);
 
 			err = tcp_send(conn->tc, mb);
 		}
 		else
-			err = conn_send(qentp, sip, secure, dst, host, mb,
+			err = conn_send(qentp, sip, secure, &dsttmp, host, mb,
 					transph, arg);
 		break;
 
@@ -1370,7 +1411,7 @@ int sip_transp_send(struct sip_connqent **qentp, struct sip *sip, void *sock,
 		conn = sock;
 		if (conn && conn->websock_conn) {
 
-			trace_send(sip, tp, conn, dst, mb);
+			trace_send(sip, tp, conn, &dsttmp, mb);
 
 			err = websock_send(conn->websock_conn, WEBSOCK_BIN,
 					   "%b",
@@ -1381,7 +1422,7 @@ int sip_transp_send(struct sip_connqent **qentp, struct sip *sip, void *sock,
 			}
 		}
 		else {
-			err = ws_conn_send(qentp, sip, secure, dst, mb,
+			err = ws_conn_send(qentp, sip, secure, &dsttmp, mb,
 					   transph, arg);
 			if (err) {
 				re_fprintf(stderr, "ws_conn_send failed"