From: xu xin <[email protected]>
For now, No matter what error pointer ip_neigh_for_gw() returns,
ip_finish_output2() always return -EINVAL, which may mislead the upper
users.
For exemple, an application uses sendto to send an UDP packet, but when the
neighbor table overflows, sendto() will get a value of -EINVAL, and it will
cause users to waste a lot of time checking parameters for errors.
Return the real errno instead of -EINVAL.
Signed-off-by: xu xin <[email protected]>
Reviewed-by: Yang Yang <[email protected]>
Cc: Si Hao <[email protected]>
---
net/ipv4/ip_output.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 6ba1a0fafbaa..f28c87533a46 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -236,7 +236,7 @@ static int ip_finish_output2(struct net *net, struct sock *sk, struct sk_buff *s
net_dbg_ratelimited("%s: No header cache and no neighbour!\n",
__func__);
kfree_skb_reason(skb, SKB_DROP_REASON_NEIGH_CREATEFAIL);
- return -EINVAL;
+ return PTR_ERR(neigh);
}
static int ip_finish_output_gso(struct net *net, struct sock *sk,
--
2.15.2
From: [email protected]
Date: Mon, 7 Aug 2023 01:54:08 +0000
> From: xu xin <[email protected]>
>
> For now, No matter what error pointer ip_neigh_for_gw() returns,
> ip_finish_output2() always return -EINVAL, which may mislead the upper
> users.
>
> For exemple, an application uses sendto to send an UDP packet, but when the
> neighbor table overflows, sendto() will get a value of -EINVAL, and it will
> cause users to waste a lot of time checking parameters for errors.
>
> Return the real errno instead of -EINVAL.
>
> Signed-off-by: xu xin <[email protected]>
> Reviewed-by: Yang Yang <[email protected]>
Recently I was also investigating a similar issue that ip_finish_output2()
returned the fixed -EINVAL. But in my case, arp_constructor() failed with
-EINVAL, and ___neigh_create() returned ERR_PTR(-EINVAL);
So, there are still confusing paths even with this patch though, the change
would be useful.
Reviewed-by: Kuniyuki Iwashima <[email protected]>
Thanks!
> Cc: Si Hao <[email protected]>
> ---
> net/ipv4/ip_output.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
> index 6ba1a0fafbaa..f28c87533a46 100644
> --- a/net/ipv4/ip_output.c
> +++ b/net/ipv4/ip_output.c
> @@ -236,7 +236,7 @@ static int ip_finish_output2(struct net *net, struct sock *sk, struct sk_buff *s
> net_dbg_ratelimited("%s: No header cache and no neighbour!\n",
> __func__);
> kfree_skb_reason(skb, SKB_DROP_REASON_NEIGH_CREATEFAIL);
> - return -EINVAL;
> + return PTR_ERR(neigh);
> }
>
> static int ip_finish_output_gso(struct net *net, struct sock *sk,
> --
> 2.15.2
On 07/08/2023 02:54, [email protected] wrote:
> From: xu xin <[email protected]>
>
> For now, No matter what error pointer ip_neigh_for_gw() returns,
> ip_finish_output2() always return -EINVAL, which may mislead the upper
> users.
>
> For exemple, an application uses sendto to send an UDP packet, but when the
> neighbor table overflows, sendto() will get a value of -EINVAL, and it will
> cause users to waste a lot of time checking parameters for errors.
>
> Return the real errno instead of -EINVAL.
>
> Signed-off-by: xu xin <[email protected]>
> Reviewed-by: Yang Yang <[email protected]>
> Cc: Si Hao <[email protected]>
> ---
Reviewed-by: Vadim Fedorenko <[email protected]>
Hello:
This patch was applied to netdev/net-next.git (main)
by Jakub Kicinski <[email protected]>:
On Mon, 7 Aug 2023 01:54:08 +0000 you wrote:
> From: xu xin <[email protected]>
>
> For now, No matter what error pointer ip_neigh_for_gw() returns,
> ip_finish_output2() always return -EINVAL, which may mislead the upper
> users.
>
> For exemple, an application uses sendto to send an UDP packet, but when the
> neighbor table overflows, sendto() will get a value of -EINVAL, and it will
> cause users to waste a lot of time checking parameters for errors.
>
> [...]
Here is the summary with links:
- [linux-next,v2] net/ipv4: return the real errno instead of -EINVAL
https://git.kernel.org/netdev/net-next/c/c67180efc507
You are awesome, thank you!
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