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: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20241210012039.1669389-2-zijianzhang@bytedance.com

diff --git a/include/net/sock.h b/include/net/sock.h
index 7464e9f9f47c503c5a41fd64e9f15c15f3c2c812..c383126f691dea58798374d79789cfe847d72eea 100644 (file)
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -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)

diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c
index 99cef92e6290cfa1d1aab7e30139cb6ff21cc87a..b21ea634909c4622ebf570d887a34a064c4ac2b9 100644 (file)
--- a/net/ipv4/tcp_bpf.c
+++ b/net/ipv4/tcp_bpf.c
@@ -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;