From: David Ahern <dah...@digitalocean.com>
This patch handles the plumbing for installing an XDP egress
program on a net_device by handling XDP_SETUP_PROG_EGRESS and
XDP_QUERY_PROG_EGRESS in generic_xdp_install handler. New static
key is added to signal when an egress program has been installed.
Update dev_xdp_uninstall to remove egress programs.
Signed-off-by: David Ahern <dah...@digitalocean.com>
---
include/linux/netdevice.h | 2 ++
net/core/dev.c | 48 +++++++++++++++++++++++++++------------
2 files changed, 36 insertions(+), 14 deletions(-)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index ee0cb73ca18a..651baeb36729 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -752,6 +752,8 @@ struct netdev_rx_queue {
#endif
} ____cacheline_aligned_in_smp;
+extern struct static_key_false xdp_egress_needed_key;
+
/*
* RX queue sysfs structures and functions.
*/
diff --git a/net/core/dev.c b/net/core/dev.c
index 88672ea4fc80..97954f835ceb 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4641,6 +4641,7 @@ void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog
*xdp_prog)
}
static DEFINE_STATIC_KEY_FALSE(generic_xdp_needed_key);
+DEFINE_STATIC_KEY_FALSE(xdp_egress_needed_key);
int do_xdp_generic(struct bpf_prog *xdp_prog, struct sk_buff *skb)
{
@@ -5336,12 +5337,12 @@ static void __netif_receive_skb_list(struct list_head
*head)
static int generic_xdp_install(struct net_device *dev, struct netdev_bpf *xdp)
{
- struct bpf_prog *old = rtnl_dereference(dev->xdp_prog);
- struct bpf_prog *new = xdp->prog;
+ struct bpf_prog *old, *new = xdp->prog;
int ret = 0;
switch (xdp->command) {
case XDP_SETUP_PROG:
+ old = rtnl_dereference(dev->xdp_prog);
rcu_assign_pointer(dev->xdp_prog, new);
if (old)
bpf_prog_put(old);
@@ -5354,11 +5355,25 @@ static int generic_xdp_install(struct net_device *dev,
struct netdev_bpf *xdp)
dev_disable_gro_hw(dev);
}
break;
+ case XDP_SETUP_PROG_EGRESS:
+ old = rtnl_dereference(dev->xdp_egress_prog);
+ rcu_assign_pointer(dev->xdp_egress_prog, new);
+ if (old)
+ bpf_prog_put(old);
+ if (old && !new)
+ static_branch_dec(&xdp_egress_needed_key);
+ else if (new && !old)
+ static_branch_inc(&xdp_egress_needed_key);
+ break;
case XDP_QUERY_PROG:
+ old = rtnl_dereference(dev->xdp_prog);
+ xdp->prog_id = old ? old->aux->id : 0;
+ break;
+ case XDP_QUERY_PROG_EGRESS:
+ old = rtnl_dereference(dev->xdp_egress_prog);
xdp->prog_id = old ? old->aux->id : 0;
break;
-
default:
ret = -EINVAL;
break;
@@ -8641,6 +8656,10 @@ static void dev_xdp_uninstall(struct net_device *dev)
/* Remove generic XDP */
WARN_ON(dev_xdp_install(dev, generic_xdp_install, NULL, 0, NULL));
+ /* Remove XDP egress */
+ WARN_ON(dev_xdp_install(dev, generic_xdp_install, NULL,
+ XDP_FLAGS_EGRESS_MODE, NULL));
+
/* Remove from the driver */
ndo_bpf = dev->netdev_ops->ndo_bpf;
if (!ndo_bpf)
@@ -8687,21 +8706,22 @@ int dev_change_xdp_fd(struct net_device *dev, struct
netlink_ext_ack *extack,
offload = flags & XDP_FLAGS_HW_MODE;
egress = flags & XDP_FLAGS_EGRESS_MODE;
- if (egress)
+ if (egress) {
query = XDP_QUERY_PROG_EGRESS;
- else
+ bpf_op = bpf_chk = generic_xdp_install;
+ } else {
query = offload ? XDP_QUERY_PROG_HW : XDP_QUERY_PROG;
-
- bpf_op = bpf_chk = ops->ndo_bpf;
- if (!bpf_op && (flags & (XDP_FLAGS_DRV_MODE | XDP_FLAGS_HW_MODE))) {
- NL_SET_ERR_MSG(extack, "underlying driver does not support XDP
in native mode");
- return -EOPNOTSUPP;
+ bpf_op = bpf_chk = ops->ndo_bpf;
+ if (!bpf_op && (flags & (XDP_FLAGS_DRV_MODE |
XDP_FLAGS_HW_MODE))) {
+ NL_SET_ERR_MSG(extack, "underlying driver does not
support XDP in native mode");
+ return -EOPNOTSUPP;
+ }
+ if (!bpf_op || (flags & XDP_FLAGS_SKB_MODE))
+ bpf_op = generic_xdp_install;
+ if (bpf_op == bpf_chk)
+ bpf_chk = generic_xdp_install;
}
- if (!bpf_op || (flags & XDP_FLAGS_SKB_MODE))
- bpf_op = generic_xdp_install;
- if (bpf_op == bpf_chk)
- bpf_chk = generic_xdp_install;
prog_id = __dev_xdp_query(dev, bpf_op, query);
if (flags & XDP_FLAGS_REPLACE) {
--
2.21.1 (Apple Git-122.3)
