diff options
author | John Fastabend <john.fastabend@gmail.com> | 2017-07-17 19:27:07 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2017-07-17 19:48:05 +0300 |
commit | 814abfabef3ceed390c10d06a0cc69a86454b6cf (patch) | |
tree | fe6ae9f9007124e1ddd76efd152f5d60db0a5bd9 /net/core/filter.c | |
parent | d445516966dcb2924741b13b27738b54df2af01a (diff) | |
download | linux-814abfabef3ceed390c10d06a0cc69a86454b6cf.tar.xz |
xdp: add bpf_redirect helper function
This adds support for a bpf_redirect helper function to the XDP
infrastructure. For now this only supports redirecting to the egress
path of a port.
In order to support drivers handling a xdp_buff natively this patches
uses a new ndo operation ndo_xdp_xmit() that takes pushes a xdp_buff
to the specified device.
If the program specifies either (a) an unknown device or (b) a device
that does not support the operation a BPF warning is thrown and the
XDP_ABORTED error code is returned.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/filter.c')
-rw-r--r-- | net/core/filter.c | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/net/core/filter.c b/net/core/filter.c index c7f737058d89..d606a66d1040 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -2412,6 +2412,51 @@ static const struct bpf_func_proto bpf_xdp_adjust_head_proto = { .arg2_type = ARG_ANYTHING, }; +static int __bpf_tx_xdp(struct net_device *dev, struct xdp_buff *xdp) +{ + if (dev->netdev_ops->ndo_xdp_xmit) { + dev->netdev_ops->ndo_xdp_xmit(dev, xdp); + return 0; + } + bpf_warn_invalid_xdp_redirect(dev->ifindex); + return -EOPNOTSUPP; +} + +int xdp_do_redirect(struct net_device *dev, struct xdp_buff *xdp) +{ + struct redirect_info *ri = this_cpu_ptr(&redirect_info); + + dev = dev_get_by_index_rcu(dev_net(dev), ri->ifindex); + ri->ifindex = 0; + if (unlikely(!dev)) { + bpf_warn_invalid_xdp_redirect(ri->ifindex); + return -EINVAL; + } + + return __bpf_tx_xdp(dev, xdp); +} +EXPORT_SYMBOL_GPL(xdp_do_redirect); + +BPF_CALL_2(bpf_xdp_redirect, u32, ifindex, u64, flags) +{ + struct redirect_info *ri = this_cpu_ptr(&redirect_info); + + if (unlikely(flags)) + return XDP_ABORTED; + + ri->ifindex = ifindex; + ri->flags = flags; + return XDP_REDIRECT; +} + +static const struct bpf_func_proto bpf_xdp_redirect_proto = { + .func = bpf_xdp_redirect, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_ANYTHING, + .arg2_type = ARG_ANYTHING, +}; + bool bpf_helper_changes_pkt_data(void *func) { if (func == bpf_skb_vlan_push || @@ -3011,6 +3056,8 @@ xdp_func_proto(enum bpf_func_id func_id) return &bpf_get_smp_processor_id_proto; case BPF_FUNC_xdp_adjust_head: return &bpf_xdp_adjust_head_proto; + case BPF_FUNC_redirect: + return &bpf_xdp_redirect_proto; default: return bpf_base_func_proto(func_id); } @@ -3310,6 +3357,11 @@ void bpf_warn_invalid_xdp_action(u32 act) } EXPORT_SYMBOL_GPL(bpf_warn_invalid_xdp_action); +void bpf_warn_invalid_xdp_redirect(u32 ifindex) +{ + WARN_ONCE(1, "Illegal XDP redirect to unsupported device ifindex(%i)\n", ifindex); +} + static bool __is_valid_sock_ops_access(int off, int size) { if (off < 0 || off >= sizeof(struct bpf_sock_ops)) |