Commit 54f89b31 authored by Cong Wang's avatar Cong Wang Committed by Daniel Borkmann
Browse files

tcp_bpf: Charge receive socket buffer in bpf_tcp_ingress() 



When bpf_tcp_ingress() is called, the skmsg is being redirected to the
ingress of the destination socket. Therefore, we should charge its
receive socket buffer, instead of sending socket buffer.

Because sk_rmem_schedule() tests pfmemalloc of skb, we need to
introduce a wrapper and call it for skmsg.

Fixes: 604326b4 ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: default avatarCong Wang <cong.wang@bytedance.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Reviewed-by: default avatarJohn Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20241210012039.1669389-2-zijianzhang@bytedance.com
parent 716f2bca

include/net/sock.h

+8 −2
Original line number Diff line number Diff line
@@ -1527,7 +1527,7 @@ static inline bool sk_wmem_schedule(struct sock *sk, int size) 
}



static inline bool

sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size)

__sk_rmem_schedule(struct sock *sk, int size, bool pfmemalloc)

{

	int delta;
@@ -1535,7 +1535,13 @@ sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size) 
		return true;

	delta = size - sk->sk_forward_alloc;

	return delta <= 0 || __sk_mem_schedule(sk, delta, SK_MEM_RECV) ||

		skb_pfmemalloc(skb);

	       pfmemalloc;

}



static inline bool

sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size)

{

	return __sk_rmem_schedule(sk, size, skb_pfmemalloc(skb));

}



static inline int sk_unused_reserved_mem(const struct sock *sk)

net/ipv4/tcp_bpf.c

+1 −1
Original line number Diff line number Diff line
@@ -49,7 +49,7 @@ static int bpf_tcp_ingress(struct sock *sk, struct sk_psock *psock, 
		sge = sk_msg_elem(msg, i);

		size = (apply && apply_bytes < sge->length) ?

			apply_bytes : sge->length;

		if (!sk_wmem_schedule(sk, size)) {

		if (!__sk_rmem_schedule(sk, size, false)) {

			if (!copied)

				ret = -ENOMEM;

			break;