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authorDaniel Borkmann <daniel@iogearbox.net>2017-04-20 00:01:17 +0300
committerDavid S. Miller <davem@davemloft.net>2017-04-21 20:53:27 +0300
commitb1d9fc41aab11f9520b2e0d57ae872e2ec5d6f32 (patch)
tree703640d0fff4a6079aa57d806fa4ee7b4f4af68a /tools
parent73e64fa4f417b22d8d5521999a631ced8e2d442e (diff)
downloadlinux-b1d9fc41aab11f9520b2e0d57ae872e2ec5d6f32.tar.xz
bpf: add napi_id read access to __sk_buff
Add napi_id access to __sk_buff for socket filter program types, tc program types and other bpf_convert_ctx_access() users. Having access to skb->napi_id is useful for per RX queue listener siloing, f.e. in combination with SO_ATTACH_REUSEPORT_EBPF and when busy polling is used, meaning SO_REUSEPORT enabled listeners can then select the corresponding socket at SYN time already [1]. The skb is marked via skb_mark_napi_id() early in the receive path (e.g., napi_gro_receive()). Currently, sockets can only use SO_INCOMING_NAPI_ID from 6d4339028b35 ("net: Introduce SO_INCOMING_NAPI_ID") as a socket option to look up the NAPI ID associated with the queue for steering, which requires a prior sk_mark_napi_id() after the socket was looked up. Semantics for the __sk_buff napi_id access are similar, meaning if skb->napi_id is < MIN_NAPI_ID (e.g. outgoing packets using sender_cpu), then an invalid napi_id of 0 is returned to the program, otherwise a valid non-zero napi_id. [1] http://netdevconf.org/2.1/slides/apr6/dumazet-BUSY-POLLING-Netdev-2.1.pdf Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'tools')
-rw-r--r--tools/include/uapi/linux/bpf.h1
-rw-r--r--tools/testing/selftests/bpf/test_verifier.c3
2 files changed, 4 insertions, 0 deletions
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 1e062bb54eec..e553529929f6 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -603,6 +603,7 @@ struct __sk_buff {
__u32 tc_classid;
__u32 data;
__u32 data_end;
+ __u32 napi_id;
};
struct bpf_tunnel_key {
diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index 6178b65fee59..95a8d5f3ab80 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -772,6 +772,9 @@ static struct bpf_test tests[] = {
BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, vlan_tci)),
BPF_JMP_IMM(BPF_JGE, BPF_REG_0, 0, 0),
+ BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
+ offsetof(struct __sk_buff, napi_id)),
+ BPF_JMP_IMM(BPF_JGE, BPF_REG_0, 0, 0),
BPF_EXIT_INSN(),
},
.result = ACCEPT,