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authorStanislav Fomichev <sdf@google.com>2019-04-01 22:57:31 +0200
committerDaniel Borkmann <daniel@iogearbox.net>2019-04-03 16:49:48 +0200
commit822fe61795018265ae14731d4e5399e5bde36864 (patch)
tree46a279c48db0fef4326e864ffc60df9146c99e19
parentselftests/bpf: fix vlan handling in flow dissector program (diff)
downloadlinux-822fe61795018265ae14731d4e5399e5bde36864.tar.xz
linux-822fe61795018265ae14731d4e5399e5bde36864.zip
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: Stanislav Fomichev <sdf@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
-rw-r--r--net/core/flow_dissector.c1
-rw-r--r--tools/testing/selftests/bpf/progs/bpf_flow.c6
2 files changed, 5 insertions, 2 deletions
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index bb1a54747d64..9b84250039df 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -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;
diff --git a/tools/testing/selftests/bpf/progs/bpf_flow.c b/tools/testing/selftests/bpf/progs/bpf_flow.c
index f177c7a6a6c7..75b17cada539 100644
--- a/tools/testing/selftests/bpf/progs/bpf_flow.c
+++ b/tools/testing/selftests/bpf/progs/bpf_flow.c
@@ -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);
}