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bpf: export bpf_sock for BPF_PROG_TYPE_CGROUP_SOCK_ADDR prog type

And let it use bpf_sk_storage_{get,delete} helpers to access socket
storage. Kernel context (struct bpf_sock_addr_kern) already has sk
member, so I just expose it to the BPF hooks. Using PTR_TO_SOCKET
instead of PTR_TO_SOCK_COMMON should be safe because the hook is
called on bind/connect.

Cc: Martin Lau <kafai@fb.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
alistair/sunxi64-5.4-dsi
Stanislav Fomichev 2019-06-12 10:30:37 -07:00 committed by Daniel Borkmann
parent d30bd78ce8
commit fb85c4a730
2 changed files with 17 additions and 0 deletions

View File

@ -3247,6 +3247,7 @@ struct bpf_sock_addr {
__u32 msg_src_ip6[4]; /* Allows 1,2,4-byte read an 4-byte write.
* Stored in network byte order.
*/
__bpf_md_ptr(struct bpf_sock *, sk);
};
/* User bpf_sock_ops struct to access socket values and specify request ops

View File

@ -5922,6 +5922,10 @@ sock_addr_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
case BPF_FUNC_skc_lookup_tcp:
return &bpf_sock_addr_skc_lookup_tcp_proto;
#endif /* CONFIG_INET */
case BPF_FUNC_sk_storage_get:
return &bpf_sk_storage_get_proto;
case BPF_FUNC_sk_storage_delete:
return &bpf_sk_storage_delete_proto;
default:
return bpf_base_func_proto(func_id);
}
@ -6828,6 +6832,13 @@ static bool sock_addr_is_valid_access(int off, int size,
if (size != size_default)
return false;
break;
case offsetof(struct bpf_sock_addr, sk):
if (type != BPF_READ)
return false;
if (size != sizeof(__u64))
return false;
info->reg_type = PTR_TO_SOCKET;
break;
default:
if (type == BPF_READ) {
if (size != size_default)
@ -7778,6 +7789,11 @@ static u32 sock_addr_convert_ctx_access(enum bpf_access_type type,
struct bpf_sock_addr_kern, struct in6_addr, t_ctx,
s6_addr32[0], BPF_SIZE(si->code), off, tmp_reg);
break;
case offsetof(struct bpf_sock_addr, sk):
*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_sock_addr_kern, sk),
si->dst_reg, si->src_reg,
offsetof(struct bpf_sock_addr_kern, sk));
break;
}
return insn - insn_buf;