qeth: l3 send dhcp in non pass thru mode

dhcp frames are valid IPv4 packets so there is no need to send them
in pass thru mode. This allows dhcp packets to pass HiperSockets.
Also the dhcp release frame is send out correctly with this patch.

Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/s390/net/qeth_core.h

@@ -763,7 +763,8 @@ static inline int qeth_get_micros(void)
 
 static inline int qeth_get_ip_version(struct sk_buff *skb)
 {
-	switch (skb->protocol) {
+	struct ethhdr *ehdr = (struct ethhdr *)skb->data;
+	switch (ehdr->h_proto) {
 	case ETH_P_IPV6:
 		return 6;
 	case ETH_P_IP:

drivers/s390/net/qeth_l3_main.c

@@ -2900,10 +2900,8 @@ static int qeth_l3_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	int data_offset = -1;
 	int nr_frags;
 
-	if ((card->info.type == QETH_CARD_TYPE_IQD) &&
-	    (((skb->protocol != htons(ETH_P_IPV6)) &&
-	      (skb->protocol != htons(ETH_P_IP))) ||
-	     card->options.sniffer))
+	if (((card->info.type == QETH_CARD_TYPE_IQD) && (!ipv)) ||
+	     card->options.sniffer)
 			goto tx_drop;
 
 	if ((card->state != CARD_STATE_UP) || !card->lan_online) {
@@ -2949,14 +2947,14 @@ static int qeth_l3_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
 		if (data_offset < 0)
 			skb_pull(new_skb, ETH_HLEN);
 	} else {
-		if (new_skb->protocol == htons(ETH_P_IP)) {
+		if (ipv == 4) {
 			if (card->dev->type == ARPHRD_IEEE802_TR)
 				skb_pull(new_skb, TR_HLEN);
 			else
 				skb_pull(new_skb, ETH_HLEN);
 		}
 
-		if (new_skb->protocol == ETH_P_IPV6 && card->vlangrp &&
+		if (ipv == 6 && card->vlangrp &&
 				vlan_tx_tag_present(new_skb)) {
 			skb_push(new_skb, VLAN_HLEN);
 			skb_copy_to_linear_data(new_skb, new_skb->data + 4, 4);