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 <r...@fb.com>
Acked-by: Yonghong Song <y...@fb.com>
---
include/uapi/linux/bpf.h | 14 ++++++++++++++
net/core/filter.c | 28 ++++++++++++++++++++++++++++
2 files changed, 42 insertions(+)
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 870113916cac..0ebaaf7f3568 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -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
diff --git a/net/core/filter.c b/net/core/filter.c
index 104d560946da..0b3c59468282 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -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);
@@ -4788,6 +4812,8 @@ 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);
}
@@ -4930,6 +4956,8 @@ 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);
}
--
2.17.1
