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| author |   Daniel Borkmann <daniel@iogearbox.net> | 2017-04-19 23:01:17 +0200 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2017-04-21 13:53:27 -0400 |
| commit | b1d9fc41aab11f9520b2e0d57ae872e2ec5d6f32 (patch) | |
| tree | 703640d0fff4a6079aa57d806fa4ee7b4f4af68a /net | |
| parent | netvsc: Deal with rescinded channels correctly (diff) | |
| download | linux-dev-b1d9fc41aab11f9520b2e0d57ae872e2ec5d6f32.tar.xz linux-dev-b1d9fc41aab11f9520b2e0d57ae872e2ec5d6f32.zip | |
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 'net')
| -rw-r--r-- | net/core/filter.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/net/core/filter.c b/net/core/filter.c index 085925834727..9a37860a80fc 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -53,6 +53,7 @@ #include <net/dst_metadata.h> #include <net/dst.h> #include <net/sock_reuseport.h> +#include <net/busy_poll.h> /** * sk_filter_trim_cap - run a packet through a socket filter @@ -3203,6 +3204,19 @@ static u32 bpf_convert_ctx_access(enum bpf_access_type type, *insn++ = BPF_MOV64_IMM(si->dst_reg, 0); #endif break; + + case offsetof(struct __sk_buff, napi_id): +#if defined(CONFIG_NET_RX_BUSY_POLL) + BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, napi_id) != 4); + + *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->src_reg, + offsetof(struct sk_buff, napi_id)); + *insn++ = BPF_JMP_IMM(BPF_JGE, si->dst_reg, MIN_NAPI_ID, 1); + *insn++ = BPF_MOV64_IMM(si->dst_reg, 0); +#else + *insn++ = BPF_MOV64_IMM(si->dst_reg, 0); +#endif + break; } return insn - insn_buf; |