diff options
| author | Daniel Borkmann <daniel@iogearbox.net> | 2016-11-28 23:16:54 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-11-30 10:27:20 -0500 |
| commit | 85de8576a0b14aecc99136cfbf90e367fa2142cb (patch) | |
| tree | 30b716ce4c318a241ef2456bf2ed1be29991bcab /net/core/dev.c | |
| parent | 0f29f05bd7064bdf0c9629511bcba7650ce364d5 (diff) | |
| download | linux-85de8576a0b14aecc99136cfbf90e367fa2142cb.tar.bz2 | |
bpf, xdp: allow to pass flags to dev_change_xdp_fd
Add an IFLA_XDP_FLAGS attribute that can be passed for setting up
XDP along with IFLA_XDP_FD, which eventually allows user space to
implement typical add/replace/delete logic for programs. Right now,
calling into dev_change_xdp_fd() will always replace previous programs.
When passed XDP_FLAGS_UPDATE_IF_NOEXIST, we can handle this more
graceful when requested by returning -EBUSY in case we try to
attach a new program, but we find that another one is already
attached. This will be used by upcoming front-end for iproute2 as
well.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/dev.c')
| -rw-r--r-- | net/core/dev.c | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 048b46b7c92a..bffb5253e778 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6692,26 +6692,42 @@ EXPORT_SYMBOL(dev_change_proto_down); * dev_change_xdp_fd - set or clear a bpf program for a device rx path * @dev: device * @fd: new program fd or negative value to clear + * @flags: xdp-related flags * * Set or clear a bpf program for a device */ -int dev_change_xdp_fd(struct net_device *dev, int fd) +int dev_change_xdp_fd(struct net_device *dev, int fd, u32 flags) { const struct net_device_ops *ops = dev->netdev_ops; struct bpf_prog *prog = NULL; - struct netdev_xdp xdp = {}; + struct netdev_xdp xdp; int err; + ASSERT_RTNL(); + if (!ops->ndo_xdp) return -EOPNOTSUPP; if (fd >= 0) { + if (flags & XDP_FLAGS_UPDATE_IF_NOEXIST) { + memset(&xdp, 0, sizeof(xdp)); + xdp.command = XDP_QUERY_PROG; + + err = ops->ndo_xdp(dev, &xdp); + if (err < 0) + return err; + if (xdp.prog_attached) + return -EBUSY; + } + prog = bpf_prog_get_type(fd, BPF_PROG_TYPE_XDP); if (IS_ERR(prog)) return PTR_ERR(prog); } + memset(&xdp, 0, sizeof(xdp)); xdp.command = XDP_SETUP_PROG; xdp.prog = prog; + err = ops->ndo_xdp(dev, &xdp); if (err < 0 && prog) bpf_prog_put(prog); |