![Vlad Yasevich](/assets/img/avatar_default.png)
Currently the functionality to untag traffic on input resides as part of the vlan module and is build only when VLAN support is enabled in the kernel. When VLAN is disabled, the function vlan_untag() turns into a stub and doesn't really untag the packets. This seems to create an interesting interaction between VMs supporting checksum offloading and some network drivers. There are some drivers that do not allow the user to change tx-vlan-offload feature of the driver. These drivers also seem to assume that any VLAN-tagged traffic they transmit will have the vlan information in the vlan_tci and not in the vlan header already in the skb. When transmitting skbs that already have tagged data with partial checksum set, the checksum doesn't appear to be updated correctly by the card thus resulting in a failure to establish TCP connections. The following is a packet trace taken on the receiver where a sender is a VM with a VLAN configued. The host VM is running on doest not have VLAN support and the outging interface on the host is tg3: 10:12:43.503055 52:54:00:ae:42:3f > 28:d2:44:7d:c2:de, ethertype 802.1Q (0x8100), length 78: vlan 100, p 0, ethertype IPv4, (tos 0x0, ttl 64, id 27243, offset 0, flags [DF], proto TCP (6), length 60) 10.0.100.1.58545 > 10.0.100.10.ircu-2: Flags [S], cksum 0xdc39 (incorrect -> 0x48d9), seq 1069378582, win 29200, options [mss 1460,sackOK,TS val 4294837885 ecr 0,nop,wscale 7], length 0 10:12:44.505556 52:54:00:ae:42:3f > 28:d2:44:7d:c2:de, ethertype 802.1Q (0x8100), length 78: vlan 100, p 0, ethertype IPv4, (tos 0x0, ttl 64, id 27244, offset 0, flags [DF], proto TCP (6), length 60) 10.0.100.1.58545 > 10.0.100.10.ircu-2: Flags [S], cksum 0xdc39 (incorrect -> 0x44ee), seq 1069378582, win 29200, options [mss 1460,sackOK,TS val 4294838888 ecr 0,nop,wscale 7], length 0 This connection finally times out. I've only access to the TG3 hardware in this configuration thus have only tested this with TG3 driver. There are a lot of other drivers that do not permit user changes to vlan acceleration features, and I don't know if they all suffere from a similar issue. The patch attempt to fix this another way. It moves the vlan header stipping code out of the vlan module and always builds it into the kernel network core. This way, even if vlan is not supported on a virtualizatoin host, the virtual machines running on top of such host will still work with VLANs enabled. CC: Patrick McHardy <kaber@trash.net> CC: Nithin Nayak Sujir <nsujir@broadcom.com> CC: Michael Chan <mchan@broadcom.com> CC: Jiri Pirko <jiri@resnulli.us> Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com> Acked-by: Jiri Pirko <jiri@resnulli.us> Signed-off-by: David S. Miller <davem@davemloft.net>
363 lines
8.3 KiB
C
363 lines
8.3 KiB
C
#include <linux/skbuff.h>
|
|
#include <linux/netdevice.h>
|
|
#include <linux/if_vlan.h>
|
|
#include <linux/netpoll.h>
|
|
#include <linux/export.h>
|
|
#include "vlan.h"
|
|
|
|
bool vlan_do_receive(struct sk_buff **skbp)
|
|
{
|
|
struct sk_buff *skb = *skbp;
|
|
__be16 vlan_proto = skb->vlan_proto;
|
|
u16 vlan_id = vlan_tx_tag_get_id(skb);
|
|
struct net_device *vlan_dev;
|
|
struct vlan_pcpu_stats *rx_stats;
|
|
|
|
vlan_dev = vlan_find_dev(skb->dev, vlan_proto, vlan_id);
|
|
if (!vlan_dev)
|
|
return false;
|
|
|
|
skb = *skbp = skb_share_check(skb, GFP_ATOMIC);
|
|
if (unlikely(!skb))
|
|
return false;
|
|
|
|
skb->dev = vlan_dev;
|
|
if (unlikely(skb->pkt_type == PACKET_OTHERHOST)) {
|
|
/* Our lower layer thinks this is not local, let's make sure.
|
|
* This allows the VLAN to have a different MAC than the
|
|
* underlying device, and still route correctly. */
|
|
if (ether_addr_equal_64bits(eth_hdr(skb)->h_dest, vlan_dev->dev_addr))
|
|
skb->pkt_type = PACKET_HOST;
|
|
}
|
|
|
|
if (!(vlan_dev_priv(vlan_dev)->flags & VLAN_FLAG_REORDER_HDR)) {
|
|
unsigned int offset = skb->data - skb_mac_header(skb);
|
|
|
|
/*
|
|
* vlan_insert_tag expect skb->data pointing to mac header.
|
|
* So change skb->data before calling it and change back to
|
|
* original position later
|
|
*/
|
|
skb_push(skb, offset);
|
|
skb = *skbp = vlan_insert_tag(skb, skb->vlan_proto,
|
|
skb->vlan_tci);
|
|
if (!skb)
|
|
return false;
|
|
skb_pull(skb, offset + VLAN_HLEN);
|
|
skb_reset_mac_len(skb);
|
|
}
|
|
|
|
skb->priority = vlan_get_ingress_priority(vlan_dev, skb->vlan_tci);
|
|
skb->vlan_tci = 0;
|
|
|
|
rx_stats = this_cpu_ptr(vlan_dev_priv(vlan_dev)->vlan_pcpu_stats);
|
|
|
|
u64_stats_update_begin(&rx_stats->syncp);
|
|
rx_stats->rx_packets++;
|
|
rx_stats->rx_bytes += skb->len;
|
|
if (skb->pkt_type == PACKET_MULTICAST)
|
|
rx_stats->rx_multicast++;
|
|
u64_stats_update_end(&rx_stats->syncp);
|
|
|
|
return true;
|
|
}
|
|
|
|
/* Must be invoked with rcu_read_lock. */
|
|
struct net_device *__vlan_find_dev_deep_rcu(struct net_device *dev,
|
|
__be16 vlan_proto, u16 vlan_id)
|
|
{
|
|
struct vlan_info *vlan_info = rcu_dereference(dev->vlan_info);
|
|
|
|
if (vlan_info) {
|
|
return vlan_group_get_device(&vlan_info->grp,
|
|
vlan_proto, vlan_id);
|
|
} else {
|
|
/*
|
|
* Lower devices of master uppers (bonding, team) do not have
|
|
* grp assigned to themselves. Grp is assigned to upper device
|
|
* instead.
|
|
*/
|
|
struct net_device *upper_dev;
|
|
|
|
upper_dev = netdev_master_upper_dev_get_rcu(dev);
|
|
if (upper_dev)
|
|
return __vlan_find_dev_deep_rcu(upper_dev,
|
|
vlan_proto, vlan_id);
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL(__vlan_find_dev_deep_rcu);
|
|
|
|
struct net_device *vlan_dev_real_dev(const struct net_device *dev)
|
|
{
|
|
struct net_device *ret = vlan_dev_priv(dev)->real_dev;
|
|
|
|
while (is_vlan_dev(ret))
|
|
ret = vlan_dev_priv(ret)->real_dev;
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(vlan_dev_real_dev);
|
|
|
|
u16 vlan_dev_vlan_id(const struct net_device *dev)
|
|
{
|
|
return vlan_dev_priv(dev)->vlan_id;
|
|
}
|
|
EXPORT_SYMBOL(vlan_dev_vlan_id);
|
|
|
|
__be16 vlan_dev_vlan_proto(const struct net_device *dev)
|
|
{
|
|
return vlan_dev_priv(dev)->vlan_proto;
|
|
}
|
|
EXPORT_SYMBOL(vlan_dev_vlan_proto);
|
|
|
|
/*
|
|
* vlan info and vid list
|
|
*/
|
|
|
|
static void vlan_group_free(struct vlan_group *grp)
|
|
{
|
|
int i, j;
|
|
|
|
for (i = 0; i < VLAN_PROTO_NUM; i++)
|
|
for (j = 0; j < VLAN_GROUP_ARRAY_SPLIT_PARTS; j++)
|
|
kfree(grp->vlan_devices_arrays[i][j]);
|
|
}
|
|
|
|
static void vlan_info_free(struct vlan_info *vlan_info)
|
|
{
|
|
vlan_group_free(&vlan_info->grp);
|
|
kfree(vlan_info);
|
|
}
|
|
|
|
static void vlan_info_rcu_free(struct rcu_head *rcu)
|
|
{
|
|
vlan_info_free(container_of(rcu, struct vlan_info, rcu));
|
|
}
|
|
|
|
static struct vlan_info *vlan_info_alloc(struct net_device *dev)
|
|
{
|
|
struct vlan_info *vlan_info;
|
|
|
|
vlan_info = kzalloc(sizeof(struct vlan_info), GFP_KERNEL);
|
|
if (!vlan_info)
|
|
return NULL;
|
|
|
|
vlan_info->real_dev = dev;
|
|
INIT_LIST_HEAD(&vlan_info->vid_list);
|
|
return vlan_info;
|
|
}
|
|
|
|
struct vlan_vid_info {
|
|
struct list_head list;
|
|
__be16 proto;
|
|
u16 vid;
|
|
int refcount;
|
|
};
|
|
|
|
static bool vlan_hw_filter_capable(const struct net_device *dev,
|
|
const struct vlan_vid_info *vid_info)
|
|
{
|
|
if (vid_info->proto == htons(ETH_P_8021Q) &&
|
|
dev->features & NETIF_F_HW_VLAN_CTAG_FILTER)
|
|
return true;
|
|
if (vid_info->proto == htons(ETH_P_8021AD) &&
|
|
dev->features & NETIF_F_HW_VLAN_STAG_FILTER)
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
static struct vlan_vid_info *vlan_vid_info_get(struct vlan_info *vlan_info,
|
|
__be16 proto, u16 vid)
|
|
{
|
|
struct vlan_vid_info *vid_info;
|
|
|
|
list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
|
|
if (vid_info->proto == proto && vid_info->vid == vid)
|
|
return vid_info;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static struct vlan_vid_info *vlan_vid_info_alloc(__be16 proto, u16 vid)
|
|
{
|
|
struct vlan_vid_info *vid_info;
|
|
|
|
vid_info = kzalloc(sizeof(struct vlan_vid_info), GFP_KERNEL);
|
|
if (!vid_info)
|
|
return NULL;
|
|
vid_info->proto = proto;
|
|
vid_info->vid = vid;
|
|
|
|
return vid_info;
|
|
}
|
|
|
|
static int __vlan_vid_add(struct vlan_info *vlan_info, __be16 proto, u16 vid,
|
|
struct vlan_vid_info **pvid_info)
|
|
{
|
|
struct net_device *dev = vlan_info->real_dev;
|
|
const struct net_device_ops *ops = dev->netdev_ops;
|
|
struct vlan_vid_info *vid_info;
|
|
int err;
|
|
|
|
vid_info = vlan_vid_info_alloc(proto, vid);
|
|
if (!vid_info)
|
|
return -ENOMEM;
|
|
|
|
if (vlan_hw_filter_capable(dev, vid_info)) {
|
|
err = ops->ndo_vlan_rx_add_vid(dev, proto, vid);
|
|
if (err) {
|
|
kfree(vid_info);
|
|
return err;
|
|
}
|
|
}
|
|
list_add(&vid_info->list, &vlan_info->vid_list);
|
|
vlan_info->nr_vids++;
|
|
*pvid_info = vid_info;
|
|
return 0;
|
|
}
|
|
|
|
int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid)
|
|
{
|
|
struct vlan_info *vlan_info;
|
|
struct vlan_vid_info *vid_info;
|
|
bool vlan_info_created = false;
|
|
int err;
|
|
|
|
ASSERT_RTNL();
|
|
|
|
vlan_info = rtnl_dereference(dev->vlan_info);
|
|
if (!vlan_info) {
|
|
vlan_info = vlan_info_alloc(dev);
|
|
if (!vlan_info)
|
|
return -ENOMEM;
|
|
vlan_info_created = true;
|
|
}
|
|
vid_info = vlan_vid_info_get(vlan_info, proto, vid);
|
|
if (!vid_info) {
|
|
err = __vlan_vid_add(vlan_info, proto, vid, &vid_info);
|
|
if (err)
|
|
goto out_free_vlan_info;
|
|
}
|
|
vid_info->refcount++;
|
|
|
|
if (vlan_info_created)
|
|
rcu_assign_pointer(dev->vlan_info, vlan_info);
|
|
|
|
return 0;
|
|
|
|
out_free_vlan_info:
|
|
if (vlan_info_created)
|
|
kfree(vlan_info);
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL(vlan_vid_add);
|
|
|
|
static void __vlan_vid_del(struct vlan_info *vlan_info,
|
|
struct vlan_vid_info *vid_info)
|
|
{
|
|
struct net_device *dev = vlan_info->real_dev;
|
|
const struct net_device_ops *ops = dev->netdev_ops;
|
|
__be16 proto = vid_info->proto;
|
|
u16 vid = vid_info->vid;
|
|
int err;
|
|
|
|
if (vlan_hw_filter_capable(dev, vid_info)) {
|
|
err = ops->ndo_vlan_rx_kill_vid(dev, proto, vid);
|
|
if (err) {
|
|
pr_warn("failed to kill vid %04x/%d for device %s\n",
|
|
proto, vid, dev->name);
|
|
}
|
|
}
|
|
list_del(&vid_info->list);
|
|
kfree(vid_info);
|
|
vlan_info->nr_vids--;
|
|
}
|
|
|
|
void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid)
|
|
{
|
|
struct vlan_info *vlan_info;
|
|
struct vlan_vid_info *vid_info;
|
|
|
|
ASSERT_RTNL();
|
|
|
|
vlan_info = rtnl_dereference(dev->vlan_info);
|
|
if (!vlan_info)
|
|
return;
|
|
|
|
vid_info = vlan_vid_info_get(vlan_info, proto, vid);
|
|
if (!vid_info)
|
|
return;
|
|
vid_info->refcount--;
|
|
if (vid_info->refcount == 0) {
|
|
__vlan_vid_del(vlan_info, vid_info);
|
|
if (vlan_info->nr_vids == 0) {
|
|
RCU_INIT_POINTER(dev->vlan_info, NULL);
|
|
call_rcu(&vlan_info->rcu, vlan_info_rcu_free);
|
|
}
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(vlan_vid_del);
|
|
|
|
int vlan_vids_add_by_dev(struct net_device *dev,
|
|
const struct net_device *by_dev)
|
|
{
|
|
struct vlan_vid_info *vid_info;
|
|
struct vlan_info *vlan_info;
|
|
int err;
|
|
|
|
ASSERT_RTNL();
|
|
|
|
vlan_info = rtnl_dereference(by_dev->vlan_info);
|
|
if (!vlan_info)
|
|
return 0;
|
|
|
|
list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
|
|
err = vlan_vid_add(dev, vid_info->proto, vid_info->vid);
|
|
if (err)
|
|
goto unwind;
|
|
}
|
|
return 0;
|
|
|
|
unwind:
|
|
list_for_each_entry_continue_reverse(vid_info,
|
|
&vlan_info->vid_list,
|
|
list) {
|
|
vlan_vid_del(dev, vid_info->proto, vid_info->vid);
|
|
}
|
|
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL(vlan_vids_add_by_dev);
|
|
|
|
void vlan_vids_del_by_dev(struct net_device *dev,
|
|
const struct net_device *by_dev)
|
|
{
|
|
struct vlan_vid_info *vid_info;
|
|
struct vlan_info *vlan_info;
|
|
|
|
ASSERT_RTNL();
|
|
|
|
vlan_info = rtnl_dereference(by_dev->vlan_info);
|
|
if (!vlan_info)
|
|
return;
|
|
|
|
list_for_each_entry(vid_info, &vlan_info->vid_list, list)
|
|
vlan_vid_del(dev, vid_info->proto, vid_info->vid);
|
|
}
|
|
EXPORT_SYMBOL(vlan_vids_del_by_dev);
|
|
|
|
bool vlan_uses_dev(const struct net_device *dev)
|
|
{
|
|
struct vlan_info *vlan_info;
|
|
|
|
ASSERT_RTNL();
|
|
|
|
vlan_info = rtnl_dereference(dev->vlan_info);
|
|
if (!vlan_info)
|
|
return false;
|
|
return vlan_info->grp.nr_vlan_devs ? true : false;
|
|
}
|
|
EXPORT_SYMBOL(vlan_uses_dev);
|