Commit 1314ef56 authored by Stanislav Fomichev's avatar Stanislav Fomichev Committed by Daniel Borkmann
Browse files

bpf: export bpf_sock for BPF_PROG_TYPE_SOCK_OPS prog type 



And let it use bpf_sk_storage_{get,delete} helpers to access socket
storage. Kernel context (struct bpf_sock_ops_kern) already has sk
member, so I just expose it to the BPF hooks. I use
PTR_TO_SOCKET_OR_NULL and return NULL in !is_fullsock case.

I also export bpf_tcp_sock to make it possible to access tcp socket stats.

Cc: Martin Lau <kafai@fb.com>
Signed-off-by: default avatarStanislav Fomichev <sdf@google.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parent fb85c4a7

include/uapi/linux/bpf.h

+1 −0
Original line number Diff line number Diff line
@@ -3299,6 +3299,7 @@ struct bpf_sock_ops { 
	__u32 sk_txhash;

	__u64 bytes_received;

	__u64 bytes_acked;

	__bpf_md_ptr(struct bpf_sock *, sk);

};



/* Definitions for bpf_sock_ops_cb_flags */

net/core/filter.c

+26 −0
Original line number Diff line number Diff line
@@ -6147,6 +6147,14 @@ sock_ops_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 
		return &bpf_get_local_storage_proto;

	case BPF_FUNC_perf_event_output:

		return &bpf_sockopt_event_output_proto;

	case BPF_FUNC_sk_storage_get:

		return &bpf_sk_storage_get_proto;

	case BPF_FUNC_sk_storage_delete:

		return &bpf_sk_storage_delete_proto;

#ifdef CONFIG_INET

	case BPF_FUNC_tcp_sock:

		return &bpf_tcp_sock_proto;

#endif /* CONFIG_INET */

	default:

		return bpf_base_func_proto(func_id);

	}
@@ -6882,6 +6890,11 @@ static bool sock_ops_is_valid_access(int off, int size, 
			if (size != sizeof(__u64))

				return false;

			break;

		case offsetof(struct bpf_sock_ops, sk):

			if (size != sizeof(__u64))

				return false;

			info->reg_type = PTR_TO_SOCKET_OR_NULL;

			break;

		default:

			if (size != size_default)

				return false;
@@ -8053,6 +8066,19 @@ static u32 sock_ops_convert_ctx_access(enum bpf_access_type type, 
		SOCK_OPS_GET_OR_SET_FIELD(sk_txhash, sk_txhash,

					  struct sock, type);

		break;

	case offsetof(struct bpf_sock_ops, sk):

		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(

						struct bpf_sock_ops_kern,

						is_fullsock),

				      si->dst_reg, si->src_reg,

				      offsetof(struct bpf_sock_ops_kern,

					       is_fullsock));

		*insn++ = BPF_JMP_IMM(BPF_JEQ, si->dst_reg, 0, 1);

		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(

						struct bpf_sock_ops_kern, sk),

				      si->dst_reg, si->src_reg,

				      offsetof(struct bpf_sock_ops_kern, sk));

		break;

	}

	return insn - insn_buf;

}

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