[PATCH net-next 3/4] bpf: add own ctx rewriter on ifindex for clsact progs
flat view
STALE3700d
REVIEWED: 1 (1M)
From: Daniel Borkmann <daniel@iogearbox.net>
Date: 2016-09-09 00:45:45
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [networking] (tcx & tc bpf, sock_addr), networking [general], the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Status: Reviewed.
1 review trailer (1 from subsystem maintainers).
When fetching ifindex, we don't need to test dev for being NULL since we're always guaranteed to have a valid dev for clsact programs. Thus, avoid this test in fast path. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> --- net/core/filter.c | 37 +++++++++++++++++++++++++++++++------ 1 file changed, 31 insertions(+), 6 deletions(-)
diff --git a/net/core/filter.c b/net/core/filter.c
index 120c813..d6d9bb8 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c@@ -2634,10 +2634,10 @@ void bpf_warn_invalid_xdp_action(u32 act) } EXPORT_SYMBOL_GPL(bpf_warn_invalid_xdp_action); -static u32 bpf_net_convert_ctx_access(enum bpf_access_type type, int dst_reg, - int src_reg, int ctx_off, - struct bpf_insn *insn_buf, - struct bpf_prog *prog) +static u32 sk_filter_convert_ctx_access(enum bpf_access_type type, int dst_reg, + int src_reg, int ctx_off, + struct bpf_insn *insn_buf, + struct bpf_prog *prog) { struct bpf_insn *insn = insn_buf;
@@ -2785,6 +2785,31 @@ static u32 bpf_net_convert_ctx_access(enum bpf_access_type type, int dst_reg, return insn - insn_buf; } +static u32 tc_cls_act_convert_ctx_access(enum bpf_access_type type, int dst_reg, + int src_reg, int ctx_off, + struct bpf_insn *insn_buf, + struct bpf_prog *prog) +{ + struct bpf_insn *insn = insn_buf; + + switch (ctx_off) { + case offsetof(struct __sk_buff, ifindex): + BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, ifindex) != 4); + + *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, dev), + dst_reg, src_reg, + offsetof(struct sk_buff, dev)); + *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, dst_reg, + offsetof(struct net_device, ifindex)); + break; + default: + return sk_filter_convert_ctx_access(type, dst_reg, src_reg, + ctx_off, insn_buf, prog); + } + + return insn - insn_buf; +} + static u32 xdp_convert_ctx_access(enum bpf_access_type type, int dst_reg, int src_reg, int ctx_off, struct bpf_insn *insn_buf,
@@ -2811,13 +2836,13 @@ static u32 xdp_convert_ctx_access(enum bpf_access_type type, int dst_reg, static const struct bpf_verifier_ops sk_filter_ops = { .get_func_proto = sk_filter_func_proto, .is_valid_access = sk_filter_is_valid_access, - .convert_ctx_access = bpf_net_convert_ctx_access, + .convert_ctx_access = sk_filter_convert_ctx_access, }; static const struct bpf_verifier_ops tc_cls_act_ops = { .get_func_proto = tc_cls_act_func_proto, .is_valid_access = tc_cls_act_is_valid_access, - .convert_ctx_access = bpf_net_convert_ctx_access, + .convert_ctx_access = tc_cls_act_convert_ctx_access, }; static const struct bpf_verifier_ops xdp_ops = {
--
1.9.3