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authorVladimir Oltean <olteanv@gmail.com>2019-06-08 15:04:29 +0300
committerDavid S. Miller <davem@davemloft.net>2019-06-08 15:20:39 -0700
commitd461933638ae9fa49ad22f60a40de5b3ed414912 (patch)
treeb64fade690f6cf9244260f0640e0e02a1065eb29 /net/dsa
parent5e3f847a02aabfecea519d7b2fd48f4d6f551be6 (diff)
downloadlinux-d461933638ae9fa49ad22f60a40de5b3ed414912.tar.bz2
net: dsa: tag_8021q: Create helper function for removing VLAN header
This removes the existing implementation from tag_sja1105, which was partially incorrect (it was not changing the MAC header offset, thereby leaving it to point 4 bytes earlier than it should have). This overwrites the VLAN tag by moving the Ethernet source and destination MACs 4 bytes to the right. Then skb->data (assumed to be pointing immediately after the EtherType) is temporarily pushed to the beginning of the new Ethernet header, the new Ethernet header offset and length are recorded, then skb->data is moved back to where it was. Signed-off-by: Vladimir Oltean <olteanv@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/dsa')
-rw-r--r--net/dsa/tag_8021q.c57
-rw-r--r--net/dsa/tag_sja1105.c19
2 files changed, 46 insertions, 30 deletions
diff --git a/net/dsa/tag_8021q.c b/net/dsa/tag_8021q.c
index 65a35e976d7b..6ebbd799c4eb 100644
--- a/net/dsa/tag_8021q.c
+++ b/net/dsa/tag_8021q.c
@@ -235,31 +235,48 @@ struct sk_buff *dsa_8021q_xmit(struct sk_buff *skb, struct net_device *netdev,
}
EXPORT_SYMBOL_GPL(dsa_8021q_xmit);
-struct sk_buff *dsa_8021q_rcv(struct sk_buff *skb, struct net_device *netdev,
- struct packet_type *pt, u16 *tpid, u16 *tci)
+/* In the DSA packet_type handler, skb->data points in the middle of the VLAN
+ * tag, after tpid and before tci. This is because so far, ETH_HLEN
+ * (DMAC, SMAC, EtherType) bytes were pulled.
+ * There are 2 bytes of VLAN tag left in skb->data, and upper
+ * layers expect the 'real' EtherType to be consumed as well.
+ * Coincidentally, a VLAN header is also of the same size as
+ * the number of bytes that need to be pulled.
+ *
+ * skb_mac_header skb->data
+ * | |
+ * v v
+ * | | | | | | | | | | | | | | | | | | |
+ * +-----------------------+-----------------------+-------+-------+-------+
+ * | Destination MAC | Source MAC | TPID | TCI | EType |
+ * +-----------------------+-----------------------+-------+-------+-------+
+ * ^ | |
+ * |<--VLAN_HLEN-->to <---VLAN_HLEN--->
+ * from |
+ * >>>>>>> v
+ * >>>>>>> | | | | | | | | | | | | | | |
+ * >>>>>>> +-----------------------+-----------------------+-------+
+ * >>>>>>> | Destination MAC | Source MAC | EType |
+ * +-----------------------+-----------------------+-------+
+ * ^ ^
+ * (now part of | |
+ * skb->head) skb_mac_header skb->data
+ */
+struct sk_buff *dsa_8021q_remove_header(struct sk_buff *skb)
{
- struct vlan_ethhdr *tag;
-
- if (unlikely(!pskb_may_pull(skb, VLAN_HLEN)))
- return NULL;
+ u8 *from = skb_mac_header(skb);
+ u8 *dest = from + VLAN_HLEN;
- tag = vlan_eth_hdr(skb);
- *tpid = ntohs(tag->h_vlan_proto);
- *tci = ntohs(tag->h_vlan_TCI);
-
- /* skb->data points in the middle of the VLAN tag,
- * after tpid and before tci. This is because so far,
- * ETH_HLEN (DMAC, SMAC, EtherType) bytes were pulled.
- * There are 2 bytes of VLAN tag left in skb->data, and upper
- * layers expect the 'real' EtherType to be consumed as well.
- * Coincidentally, a VLAN header is also of the same size as
- * the number of bytes that need to be pulled.
- */
- skb_pull_rcsum(skb, VLAN_HLEN);
+ memmove(dest, from, ETH_HLEN - VLAN_HLEN);
+ skb_pull(skb, VLAN_HLEN);
+ skb_push(skb, ETH_HLEN);
+ skb_reset_mac_header(skb);
+ skb_reset_mac_len(skb);
+ skb_pull_rcsum(skb, ETH_HLEN);
return skb;
}
-EXPORT_SYMBOL_GPL(dsa_8021q_rcv);
+EXPORT_SYMBOL_GPL(dsa_8021q_remove_header);
static const struct dsa_device_ops dsa_8021q_netdev_ops = {
.name = "8021q",
diff --git a/net/dsa/tag_sja1105.c b/net/dsa/tag_sja1105.c
index d43737e6c3fb..77eeea004e92 100644
--- a/net/dsa/tag_sja1105.c
+++ b/net/dsa/tag_sja1105.c
@@ -66,17 +66,14 @@ static struct sk_buff *sja1105_rcv(struct sk_buff *skb,
struct net_device *netdev,
struct packet_type *pt)
{
- struct ethhdr *hdr = eth_hdr(skb);
- u64 source_port, switch_id;
- struct sk_buff *nskb;
+ int source_port, switch_id;
+ struct vlan_ethhdr *hdr;
u16 tpid, vid, tci;
bool is_tagged;
- nskb = dsa_8021q_rcv(skb, netdev, pt, &tpid, &tci);
- is_tagged = (nskb && tpid == ETH_P_SJA1105);
-
- skb->priority = (tci & VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT;
- vid = tci & VLAN_VID_MASK;
+ hdr = vlan_eth_hdr(skb);
+ tpid = ntohs(hdr->h_vlan_proto);
+ is_tagged = (tpid == ETH_P_SJA1105);
skb->offload_fwd_mark = 1;
@@ -92,8 +89,11 @@ static struct sk_buff *sja1105_rcv(struct sk_buff *skb,
hdr->h_dest[4] = 0;
} else {
/* Normal traffic path. */
+ tci = ntohs(hdr->h_vlan_TCI);
+ vid = tci & VLAN_VID_MASK;
source_port = dsa_8021q_rx_source_port(vid);
switch_id = dsa_8021q_rx_switch_id(vid);
+ skb->priority = (tci & VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT;
}
skb->dev = dsa_master_find_slave(netdev, switch_id, source_port);
@@ -106,8 +106,7 @@ static struct sk_buff *sja1105_rcv(struct sk_buff *skb,
* it there, see dsa_switch_rcv: skb_push(skb, ETH_HLEN).
*/
if (is_tagged)
- memmove(skb->data - ETH_HLEN, skb->data - ETH_HLEN - VLAN_HLEN,
- ETH_HLEN - VLAN_HLEN);
+ skb = dsa_8021q_remove_header(skb);
return skb;
}