diff mbox series

[bpf-next,v3,18/21] net: make vlan_get_tag() return -ENODATA instead of -EINVAL

Message ID 20230719183734.21681-19-larysa.zaremba@intel.com (mailing list archive)
State Changes Requested
Delegated to: BPF
Headers show
Series XDP metadata via kfuncs for ice | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for bpf-next, async
netdev/apply fail Patch does not apply to bpf-next
bpf/vmtest-bpf-next-PR success PR summary
bpf/vmtest-bpf-next-VM_Test-1 success Logs for ShellCheck
bpf/vmtest-bpf-next-VM_Test-2 success Logs for build for aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-3 success Logs for build for s390x with gcc
bpf/vmtest-bpf-next-VM_Test-4 success Logs for build for x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-5 success Logs for build for x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-6 success Logs for set-matrix
bpf/vmtest-bpf-next-VM_Test-7 success Logs for test_maps on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-8 success Logs for test_maps on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-9 success Logs for test_maps on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-10 success Logs for test_maps on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-11 success Logs for test_progs on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-12 success Logs for test_progs on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-13 success Logs for test_progs on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-14 success Logs for test_progs on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-15 success Logs for test_progs_no_alu32 on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-16 success Logs for test_progs_no_alu32 on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-17 success Logs for test_progs_no_alu32 on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-18 success Logs for test_progs_no_alu32 on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-19 success Logs for test_progs_no_alu32_parallel on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-20 success Logs for test_progs_no_alu32_parallel on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-21 success Logs for test_progs_no_alu32_parallel on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-22 success Logs for test_progs_parallel on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-23 success Logs for test_progs_parallel on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-24 success Logs for test_progs_parallel on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-25 success Logs for test_verifier on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-26 success Logs for test_verifier on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-27 success Logs for test_verifier on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-28 success Logs for test_verifier on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-29 success Logs for veristat

Commit Message

Larysa Zaremba July 19, 2023, 6:37 p.m. UTC 
__vlan_hwaccel_get_tag() is used in veth XDP hints implementation,
its return value (-EINVAL if skb is not VLAN tagged) is passed to bpf code,
but XDP hints specification requires drivers to return -ENODATA, if a hint
cannot be provided for a particular packet.

Solve this inconsistency by changing error return value of
__vlan_hwaccel_get_tag() from -EINVAL to -ENODATA, do the same thing to
__vlan_get_tag(), because this function is supposed to follow the same
convention. This, in turn, makes -ENODATA the only non-zero value
vlan_get_tag() can return. We can do this with no side effects, because
none of the users of the 3 above-mentioned functions rely on the exact
value.

Suggested-by: Jesper Dangaard Brouer <jbrouer@redhat.com>
Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
---
 include/linux/if_vlan.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Stanislav Fomichev July 20, 2023, 10:02 p.m. UTC | #1 
On 07/19, Larysa Zaremba wrote:
> __vlan_hwaccel_get_tag() is used in veth XDP hints implementation,
> its return value (-EINVAL if skb is not VLAN tagged) is passed to bpf code,
> but XDP hints specification requires drivers to return -ENODATA, if a hint
> cannot be provided for a particular packet.
> 
> Solve this inconsistency by changing error return value of
> __vlan_hwaccel_get_tag() from -EINVAL to -ENODATA, do the same thing to
> __vlan_get_tag(), because this function is supposed to follow the same
> convention. This, in turn, makes -ENODATA the only non-zero value
> vlan_get_tag() can return. We can do this with no side effects, because
> none of the users of the 3 above-mentioned functions rely on the exact
> value.
> 
> Suggested-by: Jesper Dangaard Brouer <jbrouer@redhat.com>
> Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>

Acked-by: Stanislav Fomichev <sdf@google.com>

> ---
>  include/linux/if_vlan.h | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h
> index 6ba71957851e..fb35d7dd77a2 100644
> --- a/include/linux/if_vlan.h
> +++ b/include/linux/if_vlan.h
> @@ -540,7 +540,7 @@ static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
>  	struct vlan_ethhdr *veth = skb_vlan_eth_hdr(skb);
>  
>  	if (!eth_type_vlan(veth->h_vlan_proto))
> -		return -EINVAL;
> +		return -ENODATA;
>  
>  	*vlan_tci = ntohs(veth->h_vlan_TCI);
>  	return 0;
> @@ -561,7 +561,7 @@ static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
>  		return 0;
>  	} else {
>  		*vlan_tci = 0;
> -		return -EINVAL;
> +		return -ENODATA;
>  	}
>  }
>  
> -- 
> 2.41.0
>
diff mbox series

Patch

diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h
index 6ba71957851e..fb35d7dd77a2 100644
--- a/include/linux/if_vlan.h
+++ b/include/linux/if_vlan.h
@@ -540,7 +540,7 @@  static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
 	struct vlan_ethhdr *veth = skb_vlan_eth_hdr(skb);
 
 	if (!eth_type_vlan(veth->h_vlan_proto))
-		return -EINVAL;
+		return -ENODATA;
 
 	*vlan_tci = ntohs(veth->h_vlan_TCI);
 	return 0;
@@ -561,7 +561,7 @@  static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
 		return 0;
 	} else {
 		*vlan_tci = 0;
-		return -EINVAL;
+		return -ENODATA;
 	}
 }