Re: Urgent problem: Cannot connect to URL

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From: Markus Strobl (m.strobl_if_youre_a_spam_program_dont_remove_this__at_racon-linz.at)
Date: 02/02/04 

Date: Mon, 2 Feb 2004 16:43:18 +0100

hi!

thanks a lot for your reply .. we researched more (incl. network-traces) in
this case and found the following behaviour which in our oppinion is a bug
in wininet.dll (or any dependant library):

our clients are configured to use a .pac file for automatic proxy
configuration. when starting our application which uses wininet.dll for
http-access, the .pac-file isn't used at all although we passed
INTERNET_OPEN_TYPE_PRECONFIG to the InternetOpen-function which should read
the proxy-configuration from the ie-registry-settings.
the function HttpSendRequest from wininet.dll somehow totally ignores the
proxy-settings on the first try and tries to connect directly to the
webserver (without proxy). this wasn't possible from the client we found
this problem because routers with accesslists were between the client and
the webserver!
wininet.dll retried to connect a few times and then failed.
on the second request the .pac file is downloaded from the proxy (as it
should be) and everything worked fine.
internet explorer didn't download the .pac file too but somehow knew he has
to go over the proxy...
this was only the case when we were logged in as a normal user. when we were
logged in as administrator everything worked fine from our application.
we are running windows nt 4.0 sp6 on our clients and apache with webshere on
the server.
what's your oppinion in this case?

greetings markus

"Robert Aldwinckle" <robald@techemail.com> schrieb im Newsbeitrag
news:ePZyQcD6DHA.1504@TK2MSFTNGP12.phx.gbl...
> > the first request fails with wininet-error 12029 (cannot connect)
>
> Do you have a packet trace of the two cases?
>
> Which OS? FWIW I recently discovered that on XP you could use
> its netcap tool if you don't have anything better for capturing packets.
>
>
> > does anybody know in which way the javascript in the
> > .pac file is executed?
>
> Don't know. Is that script affected by the Security settings
> for scripting? E.g. do you see a prompt if you change your
> settings to Prompt for Active Scripting? (That might let you
> know if there is a timing factor involved.)
>
>
> Good luck
>
> Robert Aldwinckle
> ---
>
>
> "Markus Strobl"
<m.strobl_if_youre_a_spam_program_dont_remove_this_@racon-linz.at> wrote in
message
> news:%23lXxRkZ5DHA.1948@TK2MSFTNGP12.phx.gbl...
> > hi,
> >
> > the browsers of ours customers are configured to retrieve proxy settings
via
> > .pac autoconfiguration file.
> > if the file referenced by the url specified is out of date, internet
> > explorer downloads this file and somehow will execute the javascript in
it
> > ....
> >
> > now lets look on our problem: when sending a http request using
wininet.dll
> > the first request fails with wininet-error 12029 (cannot connect) .. the
> > client isn't even seen on the proxy server, but every following request
> > succeeds ... so our guess is, the component has a problem retrieving the
> > proxy server the first time and uses some kind of default proxy-settings
for
> > the following attemps.
> >
> > this only happens when starting our program with a normal user, when
> > starting as an admin-user it succeeds. so perhaps the user has no right
to
> > execute the java script? does anybody know in wich way the javascript in
the
> > .pac file is executed?
> >
> > if we try to navigate to this url using internet explorer it succeeds
every
> > time, even with the normal user.
> > so its a very strange thing and we don't have any clue where to start
> > researching.
> >
> > we have the problem on certain places using internet explorer 6 and 5.
> > version number of the wininet.dll is v5.0.29.19.6305 and we're running
> > windows nt 4.0 SP 6.
> >
> > please help, because its a very urgent problem to me ...
> > thanks a lot for any help!!!
> >
> > greetings markus
> >
> >
>
>
>

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