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| author |   Toke Høiland-Jørgensen <toke@redhat.com> | 2020-03-25 18:23:26 +0100 |
|---|---|---|
| committer |   Alexei Starovoitov <ast@kernel.org> | 2020-03-28 14:24:41 -0700 |
| commit | 92234c8f15c8d96ad7e52afdc5994cba6be68eb9 (patch) | |
| tree | 7c90ed94c5f54397d15f2c475732b416deda33a5 /include/linux/netdevice.h | |
| parent | bpf: Fix build warning regarding missing prototypes (diff) | |
| download | wireguard-linux-92234c8f15c8d96ad7e52afdc5994cba6be68eb9.tar.xz wireguard-linux-92234c8f15c8d96ad7e52afdc5994cba6be68eb9.zip | |
xdp: Support specifying expected existing program when attaching XDP
While it is currently possible for userspace to specify that an existing
XDP program should not be replaced when attaching to an interface, there is
no mechanism to safely replace a specific XDP program with another.
This patch adds a new netlink attribute, IFLA_XDP_EXPECTED_FD, which can be
set along with IFLA_XDP_FD. If set, the kernel will check that the program
currently loaded on the interface matches the expected one, and fail the
operation if it does not. This corresponds to a 'cmpxchg' memory operation.
Setting the new attribute with a negative value means that no program is
expected to be attached, which corresponds to setting the UPDATE_IF_NOEXIST
flag.
A new companion flag, XDP_FLAGS_REPLACE, is also added to explicitly
request checking of the EXPECTED_FD attribute. This is needed for userspace
to discover whether the kernel supports the new attribute.
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/bpf/158515700640.92963.3551295145441017022.stgit@toke.dk
Diffstat (limited to 'include/linux/netdevice.h')
| -rw-r--r-- | include/linux/netdevice.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 654808bfad83..b503d468f0df 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -3768,7 +3768,7 @@ struct sk_buff *dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev, typedef int (*bpf_op_t)(struct net_device *dev, struct netdev_bpf *bpf); int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack, - int fd, u32 flags); + int fd, int expected_fd, u32 flags); u32 __dev_xdp_query(struct net_device *dev, bpf_op_t xdp_op, enum bpf_netdev_command cmd); int xdp_umem_query(struct net_device *dev, u16 queue_id); |