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bpf: Support bpf_get_socket_cookie in more prog types

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bpf_get_socket_cookie() helper can be used to identify skb that
correspond to the same socket.

Though socket cookie can be useful in many other use-cases where socket is
available in program context. Specifically BPF_PROG_TYPE_CGROUP_SOCK_ADDR
and BPF_PROG_TYPE_SOCK_OPS programs can benefit from it so that one of
them can augment a value in a map prepared earlier by other program for
the same socket.

The patch adds support to call bpf_get_socket_cookie() from
BPF_PROG_TYPE_CGROUP_SOCK_ADDR and BPF_PROG_TYPE_SOCK_OPS.

It doesn't introduce new helpers. Instead it reuses same helper name
bpf_get_socket_cookie() but adds support to this helper to accept
`struct bpf_sock_addr` and `struct bpf_sock_ops`.

Documentation in bpf.h is changed in a way that should not break
automatic generation of markdown.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit is contained in:
Andrey Ignatov 2018-07-30 17:42:28 -07:00 committed by Daniel Borkmann
parent 240b74fde3
commit d692f1138a
2 changed files with 42 additions and 0 deletions
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14
include/uapi/linux/bpf.h
View file

@ -1371,6 +1371,20 @@ union bpf_attr {
* A 8-byte long non-decreasing number on success, or 0 if the
* socket field is missing inside *skb*.
*
* u64 bpf_get_socket_cookie(struct bpf_sock_addr *ctx)
* Description
* Equivalent to bpf_get_socket_cookie() helper that accepts
* *skb*, but gets socket from **struct bpf_sock_addr** contex.
* Return
* A 8-byte long non-decreasing number.
*
* u64 bpf_get_socket_cookie(struct bpf_sock_ops *ctx)
* Description
* Equivalent to bpf_get_socket_cookie() helper that accepts
* *skb*, but gets socket from **struct bpf_sock_ops** contex.
* Return
* A 8-byte long non-decreasing number.
*
* u32 bpf_get_socket_uid(struct sk_buff *skb)
* Return
* The owner UID of the socket associated to *skb*. If the socket

28
net/core/filter.c
View file

@ -3812,6 +3812,30 @@ static const struct bpf_func_proto bpf_get_socket_cookie_proto = {
.arg1_type = ARG_PTR_TO_CTX,
};
BPF_CALL_1(bpf_get_socket_cookie_sock_addr, struct bpf_sock_addr_kern *, ctx)
{
return sock_gen_cookie(ctx->sk);
}
static const struct bpf_func_proto bpf_get_socket_cookie_sock_addr_proto = {
.func = bpf_get_socket_cookie_sock_addr,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
};
BPF_CALL_1(bpf_get_socket_cookie_sock_ops, struct bpf_sock_ops_kern *, ctx)
{
return sock_gen_cookie(ctx->sk);
}
static const struct bpf_func_proto bpf_get_socket_cookie_sock_ops_proto = {
.func = bpf_get_socket_cookie_sock_ops,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
};
BPF_CALL_1(bpf_get_socket_uid, struct sk_buff *, skb)
{
struct sock *sk = sk_to_full_sk(skb->sk);
@ -4818,6 +4842,8 @@ sock_addr_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
default:
return NULL;
}
case BPF_FUNC_get_socket_cookie:
return &bpf_get_socket_cookie_sock_addr_proto;
default:
return bpf_base_func_proto(func_id);
}
@ -4960,6 +4986,8 @@ sock_ops_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
return &bpf_sock_map_update_proto;
case BPF_FUNC_sock_hash_update:
return &bpf_sock_hash_update_proto;
case BPF_FUNC_get_socket_cookie:
return &bpf_get_socket_cookie_sock_ops_proto;
default:
return bpf_base_func_proto(func_id);
}