qeth: tagging with VLAN-ID 0

This patch adapts qeth to handle tagged frames with VLAN-ID 0 and
with or without priority information in the tag. It enables qeth to
receive priority-tagged frames on a base interface, for example from
z/OS, without configuring an additional VLAN interface.

Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 15 insertions, 14 deletions

diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c
index 01c3c1f77879..847e8797073c 100644
--- a/drivers/s390/net/qeth_l2_main.c
+++ b/drivers/s390/net/qeth_l2_main.c
@@ -310,6 +310,8 @@ static void qeth_l2_vlan_rx_add_vid(struct net_device *dev, unsigned short vid)
         struct qeth_vlan_vid *id;
 
         QETH_CARD_TEXT_(card, 4, "aid:%d", vid);
+        if (!vid)
+                return;
         if (card->info.type == QETH_CARD_TYPE_OSM) {
                 QETH_CARD_TEXT(card, 3, "aidOSM");
                 return;
diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c
index 5b79f573bd93..c094707fcbff 100644
--- a/drivers/s390/net/qeth_l3_main.c
+++ b/drivers/s390/net/qeth_l3_main.c
@@ -2013,13 +2013,14 @@ static void qeth_l3_vlan_rx_kill_vid(struct net_device *dev, unsigned short vid)
         qeth_l3_set_multicast_list(card->dev);
 }
 
-static inline __u16 qeth_l3_rebuild_skb(struct qeth_card *card,
-                        struct sk_buff *skb, struct qeth_hdr *hdr)
+static inline int qeth_l3_rebuild_skb(struct qeth_card *card,
+                        struct sk_buff *skb, struct qeth_hdr *hdr,
+                        unsigned short *vlan_id)
 {
-        unsigned short vlan_id = 0;
         __be16 prot;
         struct iphdr *ip_hdr;
         unsigned char tg_addr[MAX_ADDR_LEN];
+        int is_vlan = 0;
 
         if (!(hdr->hdr.l3.flags & QETH_HDR_PASSTHRU)) {
                 prot = htons((hdr->hdr.l3.flags & QETH_HDR_IPV6)? ETH_P_IPV6 :
@@ -2082,8 +2083,9 @@ static inline __u16 qeth_l3_rebuild_skb(struct qeth_card *card,
 
         if (hdr->hdr.l3.ext_flags &
             (QETH_HDR_EXT_VLAN_FRAME | QETH_HDR_EXT_INCLUDE_VLAN_TAG)) {
-                vlan_id = (hdr->hdr.l3.ext_flags & QETH_HDR_EXT_VLAN_FRAME)?
+                *vlan_id = (hdr->hdr.l3.ext_flags & QETH_HDR_EXT_VLAN_FRAME) ?
                  hdr->hdr.l3.vlan_id : *((u16 *)&hdr->hdr.l3.dest_addr[12]);
+                is_vlan = 1;
         }
 
         switch (card->options.checksum_type) {
@@ -2104,7 +2106,7 @@ static inline __u16 qeth_l3_rebuild_skb(struct qeth_card *card,
                         skb->ip_summed = CHECKSUM_NONE;
         }
 
-        return vlan_id;
+        return is_vlan;
 }
 
 static int qeth_l3_process_inbound_buffer(struct qeth_card *card,
@@ -2114,6 +2116,7 @@ static int qeth_l3_process_inbound_buffer(struct qeth_card *card,
         struct sk_buff *skb;
         struct qeth_hdr *hdr;
         __u16 vlan_tag = 0;
+        int is_vlan;
         unsigned int len;
 
         *done = 0;
@@ -2129,16 +2132,12 @@ static int qeth_l3_process_inbound_buffer(struct qeth_card *card,
                 skb->dev = card->dev;
                 switch (hdr->hdr.l3.id) {
                 case QETH_HEADER_TYPE_LAYER3:
-                        vlan_tag = qeth_l3_rebuild_skb(card, skb, hdr);
+                        is_vlan = qeth_l3_rebuild_skb(card, skb, hdr,
+                                                      &vlan_tag);
                         len = skb->len;
-                        if (vlan_tag && !card->options.sniffer)
-                                if (card->vlangrp)
-                                        vlan_gro_receive(&card->napi,
-                                                card->vlangrp, vlan_tag, skb);
-                                else {
-                                        dev_kfree_skb_any(skb);
-                                        continue;
-                                }
+                        if (is_vlan && !card->options.sniffer)
+                                vlan_gro_receive(&card->napi, card->vlangrp,
+                                        vlan_tag, skb);
                         else
                                 napi_gro_receive(&card->napi, skb);
                         break;