bpf: when doing BPF_PROG_TEST_RUN for flow dissector use no-skb mode

Now that we have bpf_flow_dissect which can work on raw data,
use it when doing BPF_PROG_TEST_RUN for flow dissector.

Simplifies bpf_prog_test_run_flow_dissector and allows us to
test no-skb mode.

Note, that previously, with bpf_flow_dissect_skb we used to call
eth_type_trans which pulled L2 (ETH_HLEN) header and we explicitly called
skb_reset_network_header. That means flow_keys->nhoff would be
initialized to 0 (skb_network_offset) in init_flow_keys.
Now we call bpf_flow_dissect with nhoff set to ETH_HLEN and need
to undo it once the dissection is done to preserve the existing behavior.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit is contained in:
Stanislav Fomichev 2019-04-22 08:55:45 -07:00 committed by Daniel Borkmann
parent 089b19a920
commit 7b8a130432

View File

@ -379,12 +379,12 @@ int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog,
union bpf_attr __user *uattr)
{
u32 size = kattr->test.data_size_in;
struct bpf_flow_dissector ctx = {};
u32 repeat = kattr->test.repeat;
struct bpf_flow_keys flow_keys;
u64 time_start, time_spent = 0;
const struct ethhdr *eth;
u32 retval, duration;
struct sk_buff *skb;
struct sock *sk;
void *data;
int ret;
u32 i;
@ -395,43 +395,31 @@ int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog,
if (kattr->test.ctx_in || kattr->test.ctx_out)
return -EINVAL;
data = bpf_test_init(kattr, size, NET_SKB_PAD + NET_IP_ALIGN,
SKB_DATA_ALIGN(sizeof(struct skb_shared_info)));
if (size < ETH_HLEN)
return -EINVAL;
data = bpf_test_init(kattr, size, 0, 0);
if (IS_ERR(data))
return PTR_ERR(data);
sk = kzalloc(sizeof(*sk), GFP_USER);
if (!sk) {
kfree(data);
return -ENOMEM;
}
sock_net_set(sk, current->nsproxy->net_ns);
sock_init_data(NULL, sk);
skb = build_skb(data, 0);
if (!skb) {
kfree(data);
kfree(sk);
return -ENOMEM;
}
skb->sk = sk;
skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
__skb_put(skb, size);
skb->protocol = eth_type_trans(skb,
current->nsproxy->net_ns->loopback_dev);
skb_reset_network_header(skb);
eth = (struct ethhdr *)data;
if (!repeat)
repeat = 1;
ctx.flow_keys = &flow_keys;
ctx.data = data;
ctx.data_end = (__u8 *)data + size;
rcu_read_lock();
preempt_disable();
time_start = ktime_get_ns();
for (i = 0; i < repeat; i++) {
retval = __skb_flow_bpf_dissect(prog, skb,
&flow_keys_dissector,
&flow_keys);
retval = bpf_flow_dissect(prog, &ctx, eth->h_proto, ETH_HLEN,
size);
flow_keys.nhoff -= ETH_HLEN;
flow_keys.thoff -= ETH_HLEN;
if (signal_pending(current)) {
preempt_enable();
@ -464,7 +452,6 @@ int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog,
retval, duration);
out:
kfree_skb(skb);
kfree(sk);
kfree(data);
return ret;
}