Re: [PATCH net-next v1 2/3] net/mlx5e: Add helper for encap_info_equal for tunnels with options

From: Alexander Lobakin
Date: Wed Feb 15 2023 - 11:57:57 EST


From: Gavin Li <gavinl@xxxxxxxxxx>
Date: Wed, 15 Feb 2023 10:54:12 +0800

>
> On 2/14/2023 11:01 PM, Alexander Lobakin wrote:
>> External email: Use caution opening links or attachments
>>
>>
>> From: Gavin Li <gavinl@xxxxxxxxxx>
>> Date: Tue, 14 Feb 2023 15:41:36 +0200

[...]

>>> +     if (a_has_opts != b_has_opts)
>>> +             return false;
>>> +
>>> +     /* options stored in memory next to ip_tunnel_info struct */
>>> +     a_info = container_of(a->ip_tun_key, struct ip_tunnel_info, key);
>>> +     b_info = container_of(b->ip_tun_key, struct ip_tunnel_info, key);
>>> +
>>> +     return a_info->options_len == b_info->options_len &&
>>> +             memcmp(a_info + 1, b_info + 1, a_info->options_len) == 0;
>> 1. memcmp() is not aligned to the first expr (off-by-one to the right).
> Options start from "info + 1", see ip_tunnel_info_opts and will use it
> here to replace the "info+1".

Nah, I mean the following. Your code:

return a_info->options_len == b_info->options_len &&
memcmp(a_info + 1, b_info + 1, ...

should be:

return a_info->options_len == b_info->options_len &&
memcmp(a_info + 1, b_info + 1, ...

7 spaces instead of a tab to have it aligned to the prev line.

>> 2. `!expr` is preferred over `expr == 0`.
> ACK
>>
>>> +}
>>> +
>>>   static int cmp_decap_info(struct mlx5e_decap_key *a,
>>>                          struct mlx5e_decap_key *b)
>>>   {
>> [...]
>>
>> Thanks,
>> Olek
Thanks,
Olek