diff options
| author | David Ahern <dsa@cumulusnetworks.com> | 2016-12-01 08:48:06 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-12-02 13:46:09 -0500 |
| commit | aa4c1037a30f4e88f444e83d42c2befbe0d5caf5 (patch) | |
| tree | e2bb34c401d93df49f035a1d45c01fdff44b371d | |
| parent | ad2805dc79e647ec2aee931a51924fda9d03b2fc (diff) | |
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 <dsa@cumulusnetworks.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/net/sock.h | 15 | ||||
| -rw-r--r-- | include/uapi/linux/bpf.h | 3 | ||||
| -rw-r--r-- | net/core/filter.c | 21 |
3 files changed, 39 insertions, 0 deletions
diff --git a/include/net/sock.h b/include/net/sock.h index 442cbb118a07..69afda6bea15 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -389,6 +389,21 @@ struct sock { * Because of non atomicity rules, all * changes are protected by socket lock. */ + unsigned int __sk_flags_offset[0]; +#ifdef __BIG_ENDIAN_BITFIELD +#define SK_FL_PROTO_SHIFT 16 +#define SK_FL_PROTO_MASK 0x00ff0000 + +#define SK_FL_TYPE_SHIFT 0 +#define SK_FL_TYPE_MASK 0x0000ffff +#else +#define SK_FL_PROTO_SHIFT 8 +#define SK_FL_PROTO_MASK 0x0000ff00 + +#define SK_FL_TYPE_SHIFT 16 +#define SK_FL_TYPE_MASK 0xffff0000 +#endif + kmemcheck_bitfield_begin(flags); unsigned int sk_padding : 2, sk_no_check_tx : 1, diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index bfe5e31a1288..6123d9b8e828 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -571,6 +571,9 @@ enum bpf_ret_code { struct bpf_sock { __u32 bound_dev_if; + __u32 family; + __u32 type; + __u32 protocol; }; /* User return codes for XDP prog type. 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; |