From: George Thessalonikefs <george@nlnetlabs.nl>
Date: Tue, 12 Jul 2022 15:17:59 +0000 (+0200)
Subject: - For windows crosscompile, fix setting the IPV6_MTU socket option
X-Git-Tag: release-1.16.2~9
X-Git-Url: http://git.ipfire.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=9e4a17baaf65ea17fa384c2cbde292cba12c4bb4;p=thirdparty%2Funbound.git

- For windows crosscompile, fix setting the IPV6_MTU socket option
  equivalent (IPV6_USER_MTU); allows cross compiling with latest
  cross-compiler versions.
---

diff --git a/doc/Changelog b/doc/Changelog
index d6511e4a2..ddefbde29 100644
--- a/doc/Changelog
+++ b/doc/Changelog
@@ -1,3 +1,8 @@
+12 July 2022: George
+	- For windows crosscompile, fix setting the IPV6_MTU socket option
+	  equivalent (IPV6_USER_MTU); allows cross compiling with latest
+	  cross-compiler versions.
+
 12 July 2022: Wouter
 	- Fix dname count in sldns parse type descriptor for SVCB and HTTPS.
 
diff --git a/services/listen_dnsport.c b/services/listen_dnsport.c
index 03153bd64..1c7c177a0 100644
--- a/services/listen_dnsport.c
+++ b/services/listen_dnsport.c
@@ -490,6 +490,7 @@ create_udp_sock(int family, int socktype, struct sockaddr* addr,
 			return -1;
 		}
 # elif defined(IPV6_MTU)
+#   ifndef USE_WINSOCK
 		/*
 		 * On Linux, to send no larger than 1280, the PMTUD is
 		 * disabled by default for datagrams anyway, so we set
@@ -497,13 +498,27 @@ create_udp_sock(int family, int socktype, struct sockaddr* addr,
 		 */
 		if (setsockopt(s, IPPROTO_IPV6, IPV6_MTU,
 			(void*)&mtu, (socklen_t)sizeof(mtu)) < 0) {
-			log_err("setsockopt(..., IPV6_MTU, ...) failed: %s", 
+			log_err("setsockopt(..., IPV6_MTU, ...) failed: %s",
 				sock_strerror(errno));
 			sock_close(s);
 			*noproto = 0;
 			*inuse = 0;
 			return -1;
 		}
+#   elif defined(IPV6_USER_MTU)
+		/* As later versions of the mingw crosscompiler define
+		 * IPV6_MTU, do the same for windows but use IPV6_USER_MTU
+		 * instead which is writable; IPV6_MTU is readonly there. */
+		if (setsockopt(s, IPPROTO_IPV6, IPV6_USER_MTU,
+			(void*)&mtu, (socklen_t)sizeof(mtu)) < 0) {
+			log_err("setsockopt(..., IPV6_USER_MTU, ...) failed: %s",
+				wsa_strerror(WSAGetLastError()));
+			sock_close(s);
+			*noproto = 0;
+			*inuse = 0;
+			return -1;
+		}
+#   endif /* USE_WINSOCK */
 # endif /* IPv6 MTU */
 # if defined(IPV6_MTU_DISCOVER) && defined(IP_PMTUDISC_DONT)
 #  if defined(IP_PMTUDISC_OMIT)