From aa4c1037a30f4e88f444e83d42c2befbe0d5caf5 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Thu, 1 Dec 2016 08:48:06 -0800 Subject: bpf: Add support for reading socket family, type, protocol Add socket family, type and protocol to bpf_sock allowing bpf programs read-only access. Add __sk_flags_offset[0] to struct sock before the bitfield to programmtically determine the offset of the unsigned int containing protocol and type. Signed-off-by: David Ahern Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller --- net/core/filter.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'net') diff --git a/net/core/filter.c b/net/core/filter.c index 0ab252e462aa..56b43587d200 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -3121,6 +3121,27 @@ static u32 sock_filter_convert_ctx_access(enum bpf_access_type type, *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg, offsetof(struct sock, sk_bound_dev_if)); break; + + case offsetof(struct bpf_sock, family): + BUILD_BUG_ON(FIELD_SIZEOF(struct sock, sk_family) != 2); + + *insn++ = BPF_LDX_MEM(BPF_H, dst_reg, src_reg, + offsetof(struct sock, sk_family)); + break; + + case offsetof(struct bpf_sock, type): + *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg, + offsetof(struct sock, __sk_flags_offset)); + *insn++ = BPF_ALU32_IMM(BPF_AND, dst_reg, SK_FL_TYPE_MASK); + *insn++ = BPF_ALU32_IMM(BPF_RSH, dst_reg, SK_FL_TYPE_SHIFT); + break; + + case offsetof(struct bpf_sock, protocol): + *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg, + offsetof(struct sock, __sk_flags_offset)); + *insn++ = BPF_ALU32_IMM(BPF_AND, dst_reg, SK_FL_PROTO_MASK); + *insn++ = BPF_ALU32_IMM(BPF_RSH, dst_reg, SK_FL_PROTO_SHIFT); + break; } return insn - insn_buf; -- cgit v1.2.3-58-ga151