Hi, all.
recently met an issue: tc-flower not worked when configured dst_port and src_port range in one rule.
detailed like this: $ tc qdisc add dev ens38 ingress $ tc filter add dev ens38 ingress protocol ip flower ip_proto udp \ dst_port 5000 src_port 2000-3000 action drop
I try to find the root cause in kernel source code: 1. FLOW_DISSECTOR_KEY_PORTS and FLOW_DISSECTOR_KEY_PORTS_RANGE flag of mask->dissector were set in fl_classify from flow_dissector.c. 2. then skb_flow_dissect -> __skb_flow_dissect -> __skb_flow_dissect_ports. 3. FLOW_DISSECTOR_KEY_PORTS handled and FLOW_DISSECTOR_KEY_PORTS_RANGE not handled in __skb_flow_dissect_ports, so tp_range.tp.src was 0 here expected the actual skb source port.
By the way, __skb_flow_bpf_to_target function may has the same issue.
Please help confirm and fix it, thank you.
source code of __skb_flow_dissect_ports in flow_dissector.c as below:
static void __skb_flow_dissect_ports(const struct sk_buff *skb, struct flow_dissector *flow_dissector, void *target_container, const void *data, int nhoff, u8 ip_proto, int hlen) { enum flow_dissector_key_id dissector_ports = FLOW_DISSECTOR_KEY_MAX; struct flow_dissector_key_ports *key_ports;
if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS)) dissector_ports = FLOW_DISSECTOR_KEY_PORTS; else if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS_RANGE)) dissector_ports = FLOW_DISSECTOR_KEY_PORTS_RANGE;
if (dissector_ports == FLOW_DISSECTOR_KEY_MAX) return;
key_ports = skb_flow_dissector_target(flow_dissector, dissector_ports, target_container); key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto, data, hlen); }
Best regards.