Re: [squid-users] External C program

On Wed, Apr 29, 2009 at 9:30 PM, Bharath Raghavendran
<rbharath25_at_gmail.com> wrote:
> 2009/4/30 Julien Philibin <julien_at_philibin.fr>:
>> Very interesting Bharath !!!
>>
>> What would be your advice to get my program working ?!
>>
>> Thanks
>
> Unfortunately, I have no advice. I have made external ACLs using C++
> and know how to handle this using the "cin" stream. With my knowledge
> of C, the only thing I can think of is using file handling for stdin.
> I am sure file handling should have ways to detect EOF (I need to
> search net if you need more details :P )
>

Could you please show me your skeleton of your C++ Program ? I
developed mine in C, because I use to develop a lot in C many years
ago. But I don't mind developing it in C++ as it is not a very
complicated program (Basically just using the SQL Lib) ...

> 127.0.0.1 or "localhost" is a connection to loopback interface which
> is used to make connections to your own computer. If you have entered
> the proxy address (assuming you are using squid as a proxy server) as
> any of these two,

Yes I am using it as proxy server. And it is directly set up in my
browser's config.

>your computer connects to squid using loopback
> interface and hence your ip is shown up as 127.0.0.1.
>
> You can avoid this by putting your actual IP in the proxy address.

What do you mean ? I checked in my documentation books and I wasn't
able to find anything about the proxy's address.

And the thing is, it doesn't show up every time with 127.0.0.1, it is
(apparently) shown as 127.0.0.1 randomly ....
>
> -Bharath

>
> 2009/4/30 Julien Philibin <julien_at_philibin.fr>:
>> And also, when I take a look at the source, I don't understand why
>> sometimes I have 127.0.0.1 instead of my real IP showing up ... ?!
>>
>> Any clue ? I wasn't able to find anything about that on internet ...
>>
>> Thanks everybody
>>
>> On Wed, Apr 29, 2009 at 9:02 PM, Julien Philibin <julien_at_philibin.fr> wrote:
>>> On Wed, Apr 29, 2009 at 1:22 AM, Amos Jeffries <squid3_at_treenet.co.nz> wrote:
>>>> Julien Philibin wrote:
>>>>>
>>>>> Hi John,
>>>>> thanks for your reply.
>>>>>
>>>>> I'll give a shot with your skeleton and see how things are going on ...
>>>>>
>>>>> On Tue, Apr 28, 2009 at 1:59 AM, John Doe <jdmls_at_yahoo.com> wrote:
>>>>>>
>>>>>> From: Julien Philibin <julien_at_philibin.fr>
>>>>>>>
>>>>>>> Hi, I've been trying to find a typical external ACL C program skeleton
>>>>>>> for a while, but I wasn't able to find anything very interesting ...
>>>>>>> What I would like to do, is to read to different strings and process
>>>>>>> them in order to allow/disallow access to a website.
>>>>>>> The thing is, after a while I get two processes that use around 10 Mb
>>>>>>> of memory and 15% of my CPU ....
>>>>>>> Also, if I restart squid, I'll get two more processes running and so
>>>>>>> on, everytime I restart squid ...
>>>>>>
>>>>>> Personaly, I use fgets/fflush and I did not see any problem (memory leak,
>>>>>> etc) so far...
>>>>>> Something like:
>>>>>>
>>>>>>  #define INPUTSIZE 4096
>>>>
>>>> FYI: I've just had to start bumping my own custom helpers to using 8196 or
>>>> more for their buffers. Current Squid allow up to 8196 for URL length and
>>>> many more for possible headers length so watch that on inputs.
>>>>
>>>>
>>>>>>  char input[INPUTSIZE];
>>>>>>  while (fgets(input, sizeof(input), stdin)) {
>>>>>>   if ((cp=strchr(input, '\n')) == NULL) {
>>>>>>     fprintf(stderr, "filter: input too big: %s\n", input);
>>>>>>   } else {
>>>>>>     *cp = '\0';
>>>>>>   }
>>>>>>   ...
>>>>>>   fflush(stderr);
>>>>>>   fflush(stdout);
>>>>>>  }
>>>>>>
>>>>>> Do you use any malloc or functions that malloc... and that would need a
>>>>>> free?
>>>>>
>>>>> Yes I do, but I also free them (the memory usage doesn't change). I
>>>>> also made a mistake, it is not 10Mb but 1 ...
>>>>>
>>>>>
>>>>> THe only weird thing is that after a restart (of squid), it looks like
>>>>> squid doesn't have any control anymore on the externals programs and
>>>>> they (both of external programs) start to use a lot of CPU...
>>>>>
>>>>> Maybe it has something to do with stdin that was not flushed correctly
>>>>> and creates an infinite loop or something ...
>>>>
>>>> Probably. Squid simply closes its connection to the pipes and abandons the
>>>> old helper. Leaving the pipe close with a '\0' I believe.
>>>>  From the docs of scanf() I don't get a clear idea of the return value when
>>>> empty string is received (is it 1/0/EOF?).
>>>>
>>>
>>> I'll try to figure it out as soon as my helper is working properly :-)
>>>
>>>> Also scanf() you were using earlier has no concept of length and opens the
>>>> possibility of buffer over-runs.
>>>>
>>>> Prefer fgets or snscanf() as input methods.
>>>>
>>>
>>> Hi guys, so, I've been trying to implement the source code you gave to
>>> me. I am running into an issue.
>>>
>>> my first string is supposed to be a source (lenght <= 16)
>>> and the second one the URl of the website that the user is trying to access.
>>>
>>> When I use the fgets method: fgets(source, sizeof(source), stdin) it
>>> doesn't work. if the Ip address is less than 15, the program simply
>>> takes the beginning of the destination URL and everything goes wrong
>>> ....
>>>
>>> So I was wondering what would you guys use ?
>>>
>>> sscanf(stdin, "%s", s);
>>> or
>>> scanf("%s", &source); //as I was doing before, and double check the
>>> buffer's size
>>> or
>>> Something else?
>>>
>>> I have to admit, all this is confusing me a little bit :-)
>>> There must be an easy/secure way to catch two strings from stdin ...
>>>
>>> Thanks for your time guys.
>>>
>>>> Amos
>>>> --
>>>> Please be using
>>>>  Current Stable Squid 2.7.STABLE6 or 3.0.STABLE14
>>>>  Current Beta Squid 3.1.0.7
>>>>
>>>
>>> Julien
>>>
>>
>
Received on Thu Apr 30 2009 - 04:45:28 MDT