MFC r272323:

If the checksum coverage field in the UDPLITE header is the length
of the complete UDPLITE packet, the packet has full checksum coverage.
So fix the condition.

2 files changed, 6 insertions, 4 deletions

diff --git a/sys/netinet/udp_usrreq.c b/sys/netinet/udp_usrreq.c
index a3a365a..a02846d 100644
--- a/sys/netinet/udp_usrreq.c
+++ b/sys/netinet/udp_usrreq.c
@@ -434,9 +434,10 @@ udp_input(struct mbuf *m, int off)
 	 */
 	len = ntohs((u_short)uh->uh_ulen);
 	ip_len = ntohs(ip->ip_len) - iphlen;
-	if (pr == IPPROTO_UDPLITE && len == 0) {
+	if (pr == IPPROTO_UDPLITE && (len == 0 || len == ip_len)) {
 		/* Zero means checksum over the complete packet. */
-		len = ip_len;
+		if (len == 0)
+			len = ip_len;
 		cscov_partial = 0;
 	}
 	if (ip_len != len) {
diff --git a/sys/netinet6/udp6_usrreq.c b/sys/netinet6/udp6_usrreq.c
index 0d68590..0142804 100644
--- a/sys/netinet6/udp6_usrreq.c
+++ b/sys/netinet6/udp6_usrreq.c
@@ -225,9 +225,10 @@ udp6_input(struct mbuf **mp, int *offp, int proto)
 
 	nxt = ip6->ip6_nxt;
 	cscov_partial = (nxt == IPPROTO_UDPLITE) ? 1 : 0;
-	if (nxt == IPPROTO_UDPLITE && ulen == 0) {
+	if (nxt == IPPROTO_UDPLITE && (ulen == 0 || ulen == plen)) {
 		/* Zero means checksum over the complete packet. */
-		ulen = plen;
+		if (ulen == 0)
+			ulen = plen;
 		cscov_partial = 0;
 	}
 	if (nxt == IPPROTO_UDP && plen != ulen) {