We will support arbitrary SYN Cookie with BPF.
If BPF prog validates ACK and kfunc allocates a reqsk, it will
be carried to TCP stack as skb->sk with req->syncookie 1.
In skb_steal_sock(), we need to check inet_reqsk(sk)->syncookie
to see if the reqsk is created by kfunc. However, inet_reqsk()
is not available in sock.h.
Let's move skb_steal_sock() to request_sock.h.
While at it, we refactor skb_steal_sock() so it returns early if
skb->sk is NULL to minimise the following patch.
Signed-off-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
---
include/net/request_sock.h | 28 ++++++++++++++++++++++++++++
include/net/sock.h | 25 -------------------------
2 files changed, 28 insertions(+), 25 deletions(-)
diff --git a/include/net/request_sock.h b/include/net/request_sock.h
index 144c39db9898..26c630c40abb 100644
--- a/include/net/request_sock.h
+++ b/include/net/request_sock.h
@@ -83,6 +83,34 @@ static inline struct sock *req_to_sk(struct request_sock *req)
return (struct sock *)req;
}
+/**
+ * skb_steal_sock - steal a socket from an sk_buff
+ * @skb: sk_buff to steal the socket from
+ * @refcounted: is set to true if the socket is reference-counted
+ * @prefetched: is set to true if the socket was assigned from bpf
+ */
+static inline struct sock *skb_steal_sock(struct sk_buff *skb,
+ bool *refcounted, bool *prefetched)
+{
+ struct sock *sk = skb->sk;
+
+ if (!sk) {
+ *prefetched = false;
+ *refcounted = false;
+ return NULL;
+ }
+
+ *prefetched = skb_sk_is_prefetched(skb);
+ if (*prefetched)
+ *refcounted = sk_is_refcounted(sk);
+ else
+ *refcounted = true;
+
+ skb->destructor = NULL;
+ skb->sk = NULL;
+ return sk;
+}
+
static inline struct request_sock *
reqsk_alloc(const struct request_sock_ops *ops, struct sock *sk_listener,
bool attach_listener)
diff --git a/include/net/sock.h b/include/net/sock.h
index 1d6931caf0c3..0ed77af38000 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -2838,31 +2838,6 @@ sk_is_refcounted(struct sock *sk)
return !sk_fullsock(sk) || !sock_flag(sk, SOCK_RCU_FREE);
}
-/**
- * skb_steal_sock - steal a socket from an sk_buff
- * @skb: sk_buff to steal the socket from
- * @refcounted: is set to true if the socket is reference-counted
- * @prefetched: is set to true if the socket was assigned from bpf
- */
-static inline struct sock *
-skb_steal_sock(struct sk_buff *skb, bool *refcounted, bool *prefetched)
-{
- if (skb->sk) {
- struct sock *sk = skb->sk;
-
- *refcounted = true;
- *prefetched = skb_sk_is_prefetched(skb);
- if (*prefetched)
- *refcounted = sk_is_refcounted(sk);
- skb->destructor = NULL;
- skb->sk = NULL;
- return sk;
- }
- *prefetched = false;
- *refcounted = false;
- return NULL;
-}
-
/* Checks if this SKB belongs to an HW offloaded socket
* and whether any SW fallbacks are required based on dev.
* Check decrypted mark in case skb_orphan() cleared socket.
--
2.30.2
