Re: Problem using REDIRECT and SO_ORIGINAL_DST

[Balazs Scheidler <bazsi@balabit.hu>]

On Wed, Nov 06, 2002 at 03:22:29PM +0000, Wilson Padovani Júnior wrote:
> Hi.
> 
>     I trying to write a transparent proxy program, but I having 
> trouble to retrieve the original destination address of the redirected 
> connections.
>         SLen = sizeof(peer);
>         memset(&peer, 0, SLen);
>         getsockopt(new_sock, SOL_IP, SO_ORIGINAL_DST, &peer, &SLen);
>         printf( "Client: %s:%hu\nMe: %s:%hu\nPeer: %s:%hu\n",
>                 inet_ntoa(client.sin_addr), ntohs(client.sin_port),
>                 inet_ntoa(me.sin_addr), ntohs(me.sin_port),
>                 inet_ntoa(peer.sin_addr), ntohs(peer.sin_port) );

inet_ntoa() uses a static buffer to format its result, you are calling
inet_ntoa three times which all work on the same buffer -> the result of the
last invocation will be used three times.

try writing 3 printf() statements, or copy the result of inet_ntoa() to a
private buffer, or create your own inet_ntoa() function.

-- 
Bazsi
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