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From: Denis Kenzior <denkenz@gmail.com>
To: ell@lists.01.org
Subject: Re: [PATCH 1/2] avoid using inet_ntoa()
Date: Mon, 07 Jun 2021 13:41:30 -0500	[thread overview]
Message-ID: <2e2233ef-f787-9290-54db-1a1bc508eba4@gmail.com> (raw)
In-Reply-To: <CAJ6EMK04dtBF3JmHNmmBgin1cjLZXSGQc71M3sBLSyLS03ib+w@mail.gmail.com>

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Hi Davide,

> that might be useful for other future CLIENT_DEBUG() users.
> 

Fair enough,  Wish there was a printf extension for ipv4 and ipv6 addresses like 
printk uses...  Oh well.

> 
> yes, it seems to look better - I will also fix this.
> By the way, looking at the inet_ntop() documentation [1], I think that I can 
> also avoid things like
> 
>     inet_ntop(AF_INET, &ia, buf, INET_ADDRSTRLEN) ? : "(inv)";
> 
> because the first argument is hardcoded to AF_INET and also we are sure that 
> 'buf' is INET_ADDRSTRLEN long.
> Under these conditions, the return value of inet_ntop() should always be 'buf'. 
> Correct?

I would assume so.  You can tell for sure by looking at glibc implementation for 
example.

Oh, one other thing.  Have you checked the scope rules for GCC statement 
expressions?  inet_ntoa uses a static buffer (which glibc further enhances by 
marking it as thread-specific storage).  So the returned pointer is guaranteed 
to be valid after inet_ntoa returns.  The statement expression doesn't seem to 
do that, so that seems suspicious?

Regards,
-Denis

  reply	other threads:[~2021-06-07 18:41 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-03  9:50 [PATCH 0/2] avoid using inet_ntoa() and inet_aton() Davide Caratti
2021-06-03  9:50 ` [PATCH 1/2] avoid using inet_ntoa() Davide Caratti
2021-06-04 16:01   ` Denis Kenzior
2021-06-07 17:00     ` d. caratti
2021-06-07 18:41       ` Denis Kenzior [this message]
2021-06-08 12:46         ` d. caratti
2021-06-08 16:22           ` Denis Kenzior
2021-06-09 10:18             ` d. caratti
2021-06-10 22:12               ` Denis Kenzior
2021-06-03  9:50 ` [PATCH 2/2] avoid using inet_aton() Davide Caratti
2021-06-04 15:41   ` Denis Kenzior

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