[PATCH v4 2/2] macvtap: restore vlan header on user read
From: Basil Gor <hidden>
Date: 2012-05-04 08:56:17
Ethernet vlan header is not on the packet and kept in the skb->vlan_tci when it comes from lower dev. This patch inserts vlan header in user buffer during skb copy on user read. Signed-off-by: Basil Gor <redacted> --- drivers/net/macvtap.c | 43 ++++++++++++++++++++++++++++++++++++++----- 1 files changed, 38 insertions(+), 5 deletions(-)
diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 0427c65..cb8fd50 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c@@ -1,5 +1,6 @@ #include <linux/etherdevice.h> #include <linux/if_macvlan.h> +#include <linux/if_vlan.h> #include <linux/interrupt.h> #include <linux/nsproxy.h> #include <linux/compat.h>
@@ -759,6 +760,8 @@ static ssize_t macvtap_put_user(struct macvtap_queue *q, struct macvlan_dev *vlan; int ret; int vnet_hdr_len = 0; + int vlan_offset = 0; + int copied; if (q->flags & IFF_VNET_HDR) { struct virtio_net_hdr vnet_hdr;
@@ -773,18 +776,48 @@ static ssize_t macvtap_put_user(struct macvtap_queue *q, if (memcpy_toiovecend(iv, (void *)&vnet_hdr, 0, sizeof(vnet_hdr))) return -EFAULT; } + copied = vnet_hdr_len; + + if (!vlan_tx_tag_present(skb)) + len = min_t(int, skb->len, len); + else { + int copy; + struct { + __be16 h_vlan_proto; + __be16 h_vlan_TCI; + } veth; + veth.h_vlan_proto = htons(ETH_P_8021Q); + veth.h_vlan_TCI = htons(vlan_tx_tag_get(skb)); + + vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto); + len = min_t(int, skb->len + VLAN_HLEN, len); + + copy = min_t(int, vlan_offset, len); + ret = skb_copy_datagram_const_iovec(skb, 0, iv, copied, copy); + len -= copy; + copied += copy; + if (ret || !len) + goto done; + + copy = min_t(int, sizeof(veth), len); + ret = memcpy_toiovecend(iv, (void *)&veth, copied, copy); + len -= copy; + copied += copy; + if (ret || !len) + goto done; + } - len = min_t(int, skb->len, len); - - ret = skb_copy_datagram_const_iovec(skb, 0, iv, vnet_hdr_len, len); + ret = skb_copy_datagram_const_iovec(skb, vlan_offset, iv, copied, len); + copied += len; +done: rcu_read_lock_bh(); vlan = rcu_dereference_bh(q->vlan); if (vlan) - macvlan_count_rx(vlan, len, ret == 0, 0); + macvlan_count_rx(vlan, copied - vnet_hdr_len, ret == 0, 0); rcu_read_unlock_bh(); - return ret ? ret : (len + vnet_hdr_len); + return ret ? ret : copied; } static ssize_t macvtap_do_read(struct macvtap_queue *q, struct kiocb *iocb,
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1.7.6.5