Commit 822fe617 authored by Stanislav Fomichev's avatar Stanislav Fomichev Committed by Daniel Borkmann

net/flow_dissector: pass flow_keys->n_proto to BPF programs

This is a preparation for the next commit that would prohibit access to
the most fields of __sk_buff from the BPF programs.

Instead of requiring BPF flow dissector programs to look into skb,
pass all input data in the flow_keys.
Signed-off-by: default avatarStanislav Fomichev <sdf@google.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parent 2c3af7d9
......@@ -707,6 +707,7 @@ bool __skb_flow_bpf_dissect(struct bpf_prog *prog,
/* Pass parameters to the BPF program */
memset(flow_keys, 0, sizeof(*flow_keys));
cb->qdisc_cb.flow_keys = flow_keys;
flow_keys->n_proto = skb->protocol;
flow_keys->nhoff = skb_network_offset(skb);
flow_keys->thoff = flow_keys->nhoff;
......
......@@ -92,7 +92,6 @@ static __always_inline int parse_eth_proto(struct __sk_buff *skb, __be16 proto)
{
struct bpf_flow_keys *keys = skb->flow_keys;
keys->n_proto = proto;
switch (proto) {
case bpf_htons(ETH_P_IP):
bpf_tail_call(skb, &jmp_table, IP);
......@@ -119,7 +118,9 @@ static __always_inline int parse_eth_proto(struct __sk_buff *skb, __be16 proto)
SEC("flow_dissector")
int _dissect(struct __sk_buff *skb)
{
return parse_eth_proto(skb, skb->protocol);
struct bpf_flow_keys *keys = skb->flow_keys;
return parse_eth_proto(skb, keys->n_proto);
}
/* Parses on IPPROTO_* */
......@@ -358,6 +359,7 @@ PROG(VLAN)(struct __sk_buff *skb)
vlan->h_vlan_encapsulated_proto == bpf_htons(ETH_P_8021Q))
return BPF_DROP;
keys->n_proto = vlan->h_vlan_encapsulated_proto;
return parse_eth_proto(skb, vlan->h_vlan_encapsulated_proto);
}
......
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