linux/net/8021q/vlan_core.c
Richard Gobert 35ffb66547 net: gro: skb_gro_header helper function
Introduce a simple helper function to replace a common pattern.
When accessing the GRO header, we fetch the pointer from frag0,
then test its validity and fetch it from the skb when necessary.

This leads to the pattern
skb_gro_header_fast -> skb_gro_header_hard -> skb_gro_header_slow
recurring many times throughout GRO code.

This patch replaces these patterns with a single inlined function
call, improving code readability.

Signed-off-by: Richard Gobert <richardbgobert@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20220823071034.GA56142@debian
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-08-25 10:33:21 +02:00

552 lines
12 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/if_vlan.h>
#include <linux/netpoll.h>
#include <linux/export.h>
#include <net/gro.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 = skb_vlan_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;
if (unlikely(!(vlan_dev->flags & IFF_UP))) {
kfree_skb(skb);
*skbp = NULL;
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) &&
!netif_is_macvlan_port(vlan_dev) &&
!netif_is_bridge_port(vlan_dev)) {
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_inner_tag(skb, skb->vlan_proto,
skb->vlan_tci, skb->mac_len);
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);
__vlan_hwaccel_clear_tag(skb);
rx_stats = this_cpu_ptr(vlan_dev_priv(vlan_dev)->vlan_pcpu_stats);
u64_stats_update_begin(&rx_stats->syncp);
u64_stats_inc(&rx_stats->rx_packets);
u64_stats_add(&rx_stats->rx_bytes, skb->len);
if (skb->pkt_type == PACKET_MULTICAST)
u64_stats_inc(&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, __be16 proto)
{
if (proto == htons(ETH_P_8021Q) &&
dev->features & NETIF_F_HW_VLAN_CTAG_FILTER)
return true;
if (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_add_rx_filter_info(struct net_device *dev, __be16 proto, u16 vid)
{
if (!vlan_hw_filter_capable(dev, proto))
return 0;
if (netif_device_present(dev))
return dev->netdev_ops->ndo_vlan_rx_add_vid(dev, proto, vid);
else
return -ENODEV;
}
static int vlan_kill_rx_filter_info(struct net_device *dev, __be16 proto, u16 vid)
{
if (!vlan_hw_filter_capable(dev, proto))
return 0;
if (netif_device_present(dev))
return dev->netdev_ops->ndo_vlan_rx_kill_vid(dev, proto, vid);
else
return -ENODEV;
}
int vlan_for_each(struct net_device *dev,
int (*action)(struct net_device *dev, int vid, void *arg),
void *arg)
{
struct vlan_vid_info *vid_info;
struct vlan_info *vlan_info;
struct net_device *vdev;
int ret;
ASSERT_RTNL();
vlan_info = rtnl_dereference(dev->vlan_info);
if (!vlan_info)
return 0;
list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
vdev = vlan_group_get_device(&vlan_info->grp, vid_info->proto,
vid_info->vid);
ret = action(vdev, vid_info->vid, arg);
if (ret)
return ret;
}
return 0;
}
EXPORT_SYMBOL(vlan_for_each);
int vlan_filter_push_vids(struct vlan_info *vlan_info, __be16 proto)
{
struct net_device *real_dev = vlan_info->real_dev;
struct vlan_vid_info *vlan_vid_info;
int err;
list_for_each_entry(vlan_vid_info, &vlan_info->vid_list, list) {
if (vlan_vid_info->proto == proto) {
err = vlan_add_rx_filter_info(real_dev, proto,
vlan_vid_info->vid);
if (err)
goto unwind;
}
}
return 0;
unwind:
list_for_each_entry_continue_reverse(vlan_vid_info,
&vlan_info->vid_list, list) {
if (vlan_vid_info->proto == proto)
vlan_kill_rx_filter_info(real_dev, proto,
vlan_vid_info->vid);
}
return err;
}
EXPORT_SYMBOL(vlan_filter_push_vids);
void vlan_filter_drop_vids(struct vlan_info *vlan_info, __be16 proto)
{
struct vlan_vid_info *vlan_vid_info;
list_for_each_entry(vlan_vid_info, &vlan_info->vid_list, list)
if (vlan_vid_info->proto == proto)
vlan_kill_rx_filter_info(vlan_info->real_dev,
vlan_vid_info->proto,
vlan_vid_info->vid);
}
EXPORT_SYMBOL(vlan_filter_drop_vids);
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;
struct vlan_vid_info *vid_info;
int err;
vid_info = vlan_vid_info_alloc(proto, vid);
if (!vid_info)
return -ENOMEM;
err = vlan_add_rx_filter_info(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;
__be16 proto = vid_info->proto;
u16 vid = vid_info->vid;
int err;
err = vlan_kill_rx_filter_info(dev, proto, vid);
if (err && dev->reg_state != NETREG_UNREGISTERING)
netdev_warn(dev, "failed to kill vid %04x/%d\n", proto, vid);
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);
static struct sk_buff *vlan_gro_receive(struct list_head *head,
struct sk_buff *skb)
{
const struct packet_offload *ptype;
unsigned int hlen, off_vlan;
struct sk_buff *pp = NULL;
struct vlan_hdr *vhdr;
struct sk_buff *p;
__be16 type;
int flush = 1;
off_vlan = skb_gro_offset(skb);
hlen = off_vlan + sizeof(*vhdr);
vhdr = skb_gro_header(skb, hlen, off_vlan);
if (unlikely(!vhdr))
goto out;
type = vhdr->h_vlan_encapsulated_proto;
ptype = gro_find_receive_by_type(type);
if (!ptype)
goto out;
flush = 0;
list_for_each_entry(p, head, list) {
struct vlan_hdr *vhdr2;
if (!NAPI_GRO_CB(p)->same_flow)
continue;
vhdr2 = (struct vlan_hdr *)(p->data + off_vlan);
if (compare_vlan_header(vhdr, vhdr2))
NAPI_GRO_CB(p)->same_flow = 0;
}
skb_gro_pull(skb, sizeof(*vhdr));
skb_gro_postpull_rcsum(skb, vhdr, sizeof(*vhdr));
pp = indirect_call_gro_receive_inet(ptype->callbacks.gro_receive,
ipv6_gro_receive, inet_gro_receive,
head, skb);
out:
skb_gro_flush_final(skb, pp, flush);
return pp;
}
static int vlan_gro_complete(struct sk_buff *skb, int nhoff)
{
struct vlan_hdr *vhdr = (struct vlan_hdr *)(skb->data + nhoff);
__be16 type = vhdr->h_vlan_encapsulated_proto;
struct packet_offload *ptype;
int err = -ENOENT;
ptype = gro_find_complete_by_type(type);
if (ptype)
err = INDIRECT_CALL_INET(ptype->callbacks.gro_complete,
ipv6_gro_complete, inet_gro_complete,
skb, nhoff + sizeof(*vhdr));
return err;
}
static struct packet_offload vlan_packet_offloads[] __read_mostly = {
{
.type = cpu_to_be16(ETH_P_8021Q),
.priority = 10,
.callbacks = {
.gro_receive = vlan_gro_receive,
.gro_complete = vlan_gro_complete,
},
},
{
.type = cpu_to_be16(ETH_P_8021AD),
.priority = 10,
.callbacks = {
.gro_receive = vlan_gro_receive,
.gro_complete = vlan_gro_complete,
},
},
};
static int __init vlan_offload_init(void)
{
unsigned int i;
for (i = 0; i < ARRAY_SIZE(vlan_packet_offloads); i++)
dev_add_offload(&vlan_packet_offloads[i]);
return 0;
}
fs_initcall(vlan_offload_init);