Re: [PATCH bpf 1/2] flow_dissector: Fix to use new variables for port ranges in bpf hook

2020年1月17日(金) 2:45 Petar Penkov [off-list ref]:

On Thu, Jan 16, 2020 at 1:13 AM Yoshiki Komachi
[off-list ref] wrote:

quoted

This patch applies new flag (FLOW_DISSECTOR_KEY_PORTS_RANGE) and
field (tp_range) to BPF flow dissector to generate appropriate flow
keys when classified by specified port ranges.

Fixes: 8ffb055beae5 ("cls_flower: Fix the behavior using port ranges with hw-offload")
Signed-off-by: Yoshiki Komachi <redacted>
---
 net/core/flow_dissector.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index 2dbbb03..06bbcc3 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c

@@ -876,10 +876,17 @@ static void __skb_flow_bpf_to_target(const struct bpf_flow_keys *flow_keys,
                key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
        }

-       if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS)) {
+       if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS))
                key_ports = skb_flow_dissector_target(flow_dissector,
                                                      FLOW_DISSECTOR_KEY_PORTS,
                                                      target_container);
+       else if (dissector_uses_key(flow_dissector,
+                                   FLOW_DISSECTOR_KEY_PORTS_RANGE))
+               key_ports = skb_flow_dissector_target(flow_dissector,
+                                                     FLOW_DISSECTOR_KEY_PORTS_RANGE,
+                                                     target_container);
+
+       if (key_ports) {

If the flow dissector uses neither FLOW_DISSECTOR_KEY_PORTS_RANGE, nor
FLOW_DISSECTOR_KEY_PORTS, I believe key_ports would be used
uninitialized here. We should probably explicitly set it to NULL at
the top of this function.

Thank you for kind comments.
I will fix it, and submit the next version later.

Best regards,

--
Yoshiki Komachi

quoted

                key_ports->src = flow_keys->sport;
                key_ports->dst = flow_keys->dport;
        }
--
1.8.3.1