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authorStanislav Fomichev <sdf@google.com>2019-04-22 08:55:47 -0700
committerDaniel Borkmann <daniel@iogearbox.net>2019-04-23 18:36:34 +0200
commit9b52e3f267a6835efd50ed9002d530666d16a411 (patch)
tree4081fba58a7686bfe6c10955772b32d93f1df3a9 /net/core
parent3cbf4ffba5eeec60f82868a5facc1962d8a44d00 (diff)
flow_dissector: handle no-skb use case
When called without skb, gather all required data from the __skb_flow_dissect's arguments and use recently introduces no-skb mode of bpf flow dissector. Note: WARN_ON_ONCE(!net) will now trigger for eth_get_headlen users. Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'net/core')
-rw-r--r--net/core/flow_dissector.c52
1 files changed, 25 insertions, 27 deletions
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index f32c7e737fc6..fac712cee9d5 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -683,22 +683,6 @@ static void __skb_flow_bpf_to_target(const struct bpf_flow_keys *flow_keys,
}
}
-bool __skb_flow_bpf_dissect(struct bpf_prog *prog,
- const struct sk_buff *skb,
- struct flow_dissector *flow_dissector,
- struct bpf_flow_keys *flow_keys)
-{
- struct bpf_flow_dissector ctx = {
- .flow_keys = flow_keys,
- .skb = skb,
- .data = skb->data,
- .data_end = skb->data + skb_headlen(skb),
- };
-
- return bpf_flow_dissect(prog, &ctx, skb->protocol,
- skb_network_offset(skb), skb_headlen(skb));
-}
-
bool bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx,
__be16 proto, int nhoff, int hlen)
{
@@ -753,6 +737,7 @@ bool __skb_flow_dissect(const struct net *net,
struct flow_dissector_key_icmp *key_icmp;
struct flow_dissector_key_tags *key_tags;
struct flow_dissector_key_vlan *key_vlan;
+ struct bpf_prog *attached = NULL;
enum flow_dissect_ret fdret;
enum flow_dissector_key_id dissector_vlan = FLOW_DISSECTOR_KEY_MAX;
int num_hdrs = 0;
@@ -795,26 +780,39 @@ bool __skb_flow_dissect(const struct net *net,
target_container);
if (skb) {
- struct bpf_flow_keys flow_keys;
- struct bpf_prog *attached = NULL;
-
- rcu_read_lock();
if (!net) {
if (skb->dev)
net = dev_net(skb->dev);
else if (skb->sk)
net = sock_net(skb->sk);
- else
- WARN_ON_ONCE(1);
}
+ }
- if (net)
- attached = rcu_dereference(net->flow_dissector_prog);
+ WARN_ON_ONCE(!net);
+ if (net) {
+ rcu_read_lock();
+ attached = rcu_dereference(net->flow_dissector_prog);
if (attached) {
- ret = __skb_flow_bpf_dissect(attached, skb,
- flow_dissector,
- &flow_keys);
+ struct bpf_flow_keys flow_keys;
+ struct bpf_flow_dissector ctx = {
+ .flow_keys = &flow_keys,
+ .data = data,
+ .data_end = data + hlen,
+ };
+ __be16 n_proto = proto;
+
+ if (skb) {
+ ctx.skb = skb;
+ /* we can't use 'proto' in the skb case
+ * because it might be set to skb->vlan_proto
+ * which has been pulled from the data
+ */
+ n_proto = skb->protocol;
+ }
+
+ ret = bpf_flow_dissect(attached, &ctx, n_proto, nhoff,
+ hlen);
__skb_flow_bpf_to_target(&flow_keys, flow_dissector,
target_container);
rcu_read_unlock();