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Subject: Re: [PATCH] netfilter: initialize 'ret' variable
To:     Al Viro <viro@zeniv.linux.org.uk>
Cc:     Pablo Neira Ayuso <pablo@netfilter.org>,
        Jozsef Kadlecsik <kadlec@netfilter.org>,
        Florian Westphal <fw@strlen.de>,
        "David S . Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, netfilter-devel@vger.kernel.org,
        kernel-janitors@vger.kernel.org, coreteam@netfilter.org,
        Yu Zhe <yuzhe@nfschina.com>
References: <20221202070331.10865-1-liqiong@nfschina.com>
 <Y4mljMYvNh7zHlOh@ZenIV>
From:   liqiong <liqiong@nfschina.com>
Message-ID: <533ef392-5b77-9939-a961-872467d49cc3@nfschina.com>
Date:   Fri, 2 Dec 2022 16:06:43 +0800
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> On Fri, Dec 02, 2022 at 03:03:31PM +0800, Li Qiong wrote:
>> The 'ret' should need to be initialized to 0, in case
>> return a uninitialized value.
> Why is 0 the right value?  And which case would it be?
> We clearly need to know that to figure out which return
> value would be correct for it...
Hi, 
here is a case:
for (i = 0; i < e->num_hook_entries; i++) {
    ret = e->hooks[i].hook(e->hooks[i].priv, skb, state);
    if (ret != NF_ACCEPT)
        return ret;
    ....
}
I am not sure if  0 (NF_DROP) is the best value, but It's better to  initialize  a value.