From 879af96ffd72706c6e3278ea6b45b0b0e37ec5d7 Mon Sep 17 00:00:00 2001 From: Jussi Maki Date: Sat, 31 Jul 2021 05:57:33 +0000 Subject: net, core: Add support for XDP redirection to slave device This adds the ndo_xdp_get_xmit_slave hook for transforming XDP_TX into XDP_REDIRECT after BPF program run when the ingress device is a bond slave. The dev_xdp_prog_count is exposed so that slave devices can be checked for loaded XDP programs in order to avoid the situation where both bond master and slave have programs loaded according to xdp_state. Signed-off-by: Jussi Maki Signed-off-by: Daniel Borkmann Cc: Jay Vosburgh Cc: Veaceslav Falico Cc: Andy Gospodarek Link: https://lore.kernel.org/bpf/20210731055738.16820-3-joamaki@gmail.com --- net/core/dev.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) (limited to 'net/core/dev.c') diff --git a/net/core/dev.c b/net/core/dev.c index 64e1a5f63f93..9eb6dc9e02b3 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -9380,7 +9380,7 @@ static struct bpf_prog *dev_xdp_prog(struct net_device *dev, return dev->xdp_state[mode].prog; } -static u8 dev_xdp_prog_count(struct net_device *dev) +u8 dev_xdp_prog_count(struct net_device *dev) { u8 count = 0; int i; @@ -9390,6 +9390,7 @@ static u8 dev_xdp_prog_count(struct net_device *dev) count++; return count; } +EXPORT_SYMBOL_GPL(dev_xdp_prog_count); u32 dev_xdp_prog_id(struct net_device *dev, enum bpf_xdp_mode mode) { @@ -9483,6 +9484,8 @@ static int dev_xdp_attach(struct net_device *dev, struct netlink_ext_ack *extack { unsigned int num_modes = hweight32(flags & XDP_FLAGS_MODES); struct bpf_prog *cur_prog; + struct net_device *upper; + struct list_head *iter; enum bpf_xdp_mode mode; bpf_op_t bpf_op; int err; @@ -9521,6 +9524,14 @@ static int dev_xdp_attach(struct net_device *dev, struct netlink_ext_ack *extack return -EBUSY; } + /* don't allow if an upper device already has a program */ + netdev_for_each_upper_dev_rcu(dev, upper, iter) { + if (dev_xdp_prog_count(upper) > 0) { + NL_SET_ERR_MSG(extack, "Cannot attach when an upper device already has a program"); + return -EEXIST; + } + } + cur_prog = dev_xdp_prog(dev, mode); /* can't replace attached prog with link */ if (link && cur_prog) { -- cgit v1.2.3