From 72c87976c5abbf8a834ad85f10d03c0cd58b985c Mon Sep 17 00:00:00 2001 From: Julian Wiedmann Date: Wed, 5 Jun 2019 13:48:48 +0200 Subject: [PATCH] s390/qeth: handle limited IPv4 broadcast in L3 TX path When selecting the cast type of a neighbourless IPv4 skb (eg. on a raw socket), qeth_l3 falls back to the packet's destination IP address. For this case we should classify traffic sent to 255.255.255.255 as broadcast. This fixes DHCP requests, which were misclassified as unicast (and for IQD interfaces thus ended up on the wrong HW queue). Signed-off-by: Julian Wiedmann Signed-off-by: David S. Miller --- drivers/s390/net/qeth_l3_main.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c index 0271833da6a2..2df67abdfde7 100644 --- a/drivers/s390/net/qeth_l3_main.c +++ b/drivers/s390/net/qeth_l3_main.c @@ -1911,6 +1911,8 @@ static int qeth_l3_get_cast_type(struct sk_buff *skb) /* no neighbour (eg AF_PACKET), fall back to target's IP address ... */ switch (qeth_get_ip_version(skb)) { case 4: + if (ipv4_is_lbcast(ip_hdr(skb)->daddr)) + return RTN_BROADCAST; return ipv4_is_multicast(ip_hdr(skb)->daddr) ? RTN_MULTICAST : RTN_UNICAST; case 6: