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authorAndrii Nakryiko <andriin@fb.com>2020-08-19 22:28:41 -0700
committerAlexei Starovoitov <ast@kernel.org>2020-08-20 14:27:12 -0700
commitc8a36f1945b2b1b3f9823b66fc2181dc069cf803 (patch)
treed58459c8ddf651a7125a9e809ca4036aa841814f /net/core
parent5597432dde62befd3ab92e6ef9e073564e277ea8 (diff)
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bpf: xdp: Fix XDP mode when no mode flags specified
7f0a838254bd ("bpf, xdp: Maintain info on attached XDP BPF programs in net_device") inadvertently changed which XDP mode is assumed when no mode flags are specified explicitly. Previously, driver mode was preferred, if driver supported it. If not, generic SKB mode was chosen. That commit changed default to SKB mode always. This patch fixes the issue and restores the original logic. Fixes: 7f0a838254bd ("bpf, xdp: Maintain info on attached XDP BPF programs in net_device") Reported-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Tested-by: Lorenzo Bianconi <lorenzo@kernel.org> Link: https://lore.kernel.org/bpf/20200820052841.1559757-1-andriin@fb.com
Diffstat (limited to 'net/core')
-rw-r--r--net/core/dev.c14
1 files changed, 8 insertions, 6 deletions
diff --git a/net/core/dev.c b/net/core/dev.c
index b5d1129d8310..d42c9ea0c3c0 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -8742,13 +8742,15 @@ struct bpf_xdp_link {
int flags;
};
-static enum bpf_xdp_mode dev_xdp_mode(u32 flags)
+static enum bpf_xdp_mode dev_xdp_mode(struct net_device *dev, u32 flags)
{
if (flags & XDP_FLAGS_HW_MODE)
return XDP_MODE_HW;
if (flags & XDP_FLAGS_DRV_MODE)
return XDP_MODE_DRV;
- return XDP_MODE_SKB;
+ if (flags & XDP_FLAGS_SKB_MODE)
+ return XDP_MODE_SKB;
+ return dev->netdev_ops->ndo_bpf ? XDP_MODE_DRV : XDP_MODE_SKB;
}
static bpf_op_t dev_xdp_bpf_op(struct net_device *dev, enum bpf_xdp_mode mode)
@@ -8896,7 +8898,7 @@ static int dev_xdp_attach(struct net_device *dev, struct netlink_ext_ack *extack
return -EINVAL;
}
- mode = dev_xdp_mode(flags);
+ mode = dev_xdp_mode(dev, flags);
/* can't replace attached link */
if (dev_xdp_link(dev, mode)) {
NL_SET_ERR_MSG(extack, "Can't replace active BPF XDP link");
@@ -8984,7 +8986,7 @@ static int dev_xdp_detach_link(struct net_device *dev,
ASSERT_RTNL();
- mode = dev_xdp_mode(link->flags);
+ mode = dev_xdp_mode(dev, link->flags);
if (dev_xdp_link(dev, mode) != link)
return -EINVAL;
@@ -9080,7 +9082,7 @@ static int bpf_xdp_link_update(struct bpf_link *link, struct bpf_prog *new_prog,
goto out_unlock;
}
- mode = dev_xdp_mode(xdp_link->flags);
+ mode = dev_xdp_mode(xdp_link->dev, xdp_link->flags);
bpf_op = dev_xdp_bpf_op(xdp_link->dev, mode);
err = dev_xdp_install(xdp_link->dev, mode, bpf_op, NULL,
xdp_link->flags, new_prog);
@@ -9164,7 +9166,7 @@ out_put_dev:
int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack,
int fd, int expected_fd, u32 flags)
{
- enum bpf_xdp_mode mode = dev_xdp_mode(flags);
+ enum bpf_xdp_mode mode = dev_xdp_mode(dev, flags);
struct bpf_prog *new_prog = NULL, *old_prog = NULL;
int err;