flow_dissector: switch kernel context to struct bpf_flow_dissector

struct bpf_flow_dissector has a small subset of sk_buff fields that
flow dissector BPF program is allowed to access and an optional
pointer to real skb. Real skb is used only in bpf_skb_load_bytes
helper to read non-linear data.

The real motivation for this is to be able to call flow dissector
from eth_get_headlen context where we don't have an skb and need
to dissect raw bytes.

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 08:55:44 -07:00
committed by Daniel Borkmann
parent 7e6e185c74
commit 089b19a920
6 changed files with 117 additions and 59 deletions

View File

@@ -382,7 +382,6 @@ int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog,
u32 repeat = kattr->test.repeat;
struct bpf_flow_keys flow_keys;
u64 time_start, time_spent = 0;
struct bpf_skb_data_end *cb;
u32 retval, duration;
struct sk_buff *skb;
struct sock *sk;
@@ -423,9 +422,6 @@ int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog,
current->nsproxy->net_ns->loopback_dev);
skb_reset_network_header(skb);
cb = (struct bpf_skb_data_end *)skb->cb;
cb->qdisc_cb.flow_keys = &flow_keys;
if (!repeat)
repeat = 1;