Commit 95e752b5 authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by Alexei Starovoitov
Browse files

tcp: Move skb_steal_sock() to request_sock.h 



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: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240115205514.68364-3-kuniyu@amazon.com


Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent b18afb6f

include/net/request_sock.h

+28 −0
Original line number Diff line number Diff line
@@ -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)

include/net/sock.h

+0 −25
Original line number Diff line number Diff line
@@ -2814,31 +2814,6 @@ 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.