Date: Thu, 1 Dec 2016 09:01:32 +0100
From: Gert Doering <gert@...1296...>
Message-ID: <20161201080132.GC78624@...1296...>
References: <1480545687-19365-1-git-send-email-davids@...515...>
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In-Reply-To: <1480545687-19365-1-git-send-email-davids@...515...>
Subject: Re: [Openvpn-devel] [PATCH] push: Provide a warning if
 --ifconfig-push have argument mismatch with --topology
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To: David Sommerseth <davids@...515...>
Cc: openvpn-devel@lists.sourceforge.net

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Hi,

On Wed, Nov 30, 2016 at 11:41:27PM +0100, David Sommerseth wrote:
> +      if ((c->options.topology =3D=3D TOP_SUBNET || c->options.topology =
=3D=3D TOP_NET30)
> +          && (c->c2.push_ifconfig_remote_netmask & 0xff000000) !=3D 0xff=
000000)

Are you sure of that?  I would assume that this is stored in network
byte order (as it's an in_addr_t) so you can't directly compare it to
a number but need to run through ntohl() first.

On *intel* it might end up being the same, but code dealing with IPv4
addresses and ports always needs to be checked on both endiannesses.

Some random code I just found in a BSD header file does it that way:

#define INADDR_ALLHOSTS_GROUP   (u_int32_t)0xe0000001   /* 224.0.0.1 */
#define in_allhosts(x)  ((x).s_addr =3D=3D htonl(INADDR_ALLHOSTS_GROUP))=20=
=20=20

... so it certainly needs the htonl()

(What you can do is "peek at byte 0", which will always be the same
part of the netmask [network byte order!], and which might actually
make this easier to read .-) )

gert
--=20
USENET is *not* the non-clickable part of WWW!
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rt/
Gert Doering - Munich, Germany                             gert@...1296...
fax: +49-89-35655025                        gert@...1297...

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