[Libct] Regarding network namespaces.

[Monali Porob]

Hi Andrew, 

Got it . Silly mistake on my end :) 
Thanks for sending the sample. Its clear how to use the various APIs. 

Regards,
Monali


-----Original Message-----
From: Andrew Vagin [mailto:avagin at gmail.com] 
Sent: Friday, January 30, 2015 10:55 AM
To: Monali Porob
Cc: Andrew Vagin; libct at openvz.org
Subject: Re: [Libct] Regarding network namespaces.

On Thu, Jan 29, 2015 at 05:56:33PM +0000, Monali Porob wrote:
> Hi Andrew ,
> 
> While trying things with network namespaces , I tried  to use the
> libct_net_dev_add_ip_addr() in the test/ct_net_veth.c  and found the 
> callback is not getting spawned.
> 
> The test program exits with main:89: FAIL: CT is not alive . How 
> should I use this api . I am assuming that the api can be used to set 
> the IP address for the
> veth0 inside the namespace.  Correct me here if that’s not the case.
> 
> I have limited background of libnl.
> 
>  
> 
> I did try executing shell commands like ifconfig and setting up ip 
> addresses on veth pairs. With this I could get the namespace 
> communication set to the outside world using Routes .
> 
> I was wondering if libct APIs could be used to do the same . Hence 
> tried using libct_net_dev_add_ip_addr(). Please suggest .
> 
>  
> 
> Thanks and Regards,
> 
> Monali
> 
>  
> 
> Changed ct_net_veth.c
> 
> int main(int argc, char **argv)
> 
> {
> 
>         int p[2];
> 
>         struct ct_arg ca;
> 
>         libct_session_t s;
> 
>         ct_handler_t ct;
> 
>         ct_process_desc_t pd;
> 
>         ct_process_t pr;
> 
>         struct ct_net_veth_arg va;
> 
>         ct_net_t nd;
> 
>  
> 
>         ca.mark = mmap(NULL, 4096, PROT_READ | PROT_WRITE,
> 
>                         MAP_SHARED | MAP_ANON, 0, 0);
> 
>         pipe(p);
> 
>  
> 
>         ca.mark[0] = 0;
> 
>         ca.mark[1] = 0;
> 
>         ca.mark[2] = 0;
> 
>         ca.wait_pipe = p[0];
> 
>  
> 
>         va.host_name = VETH_HOST_NAME;
> 
>         va.ct_name = VETH_CT_NAME;
> 
>  
> 
>         s = libct_session_open_local();
> 
>         ct = libct_container_create(s, "test");
> 
>         pd = libct_process_desc_create(s);
> 
>         libct_container_set_nsmask(ct, CLONE_NEWNET);
> 
>  
> 
>         nd = libct_net_add(ct, CT_NET_VETH, &va);
> 
>         if (libct_handle_is_err(nd))
> 
>                 return tst_err("Can't add hostnic");
> 
>  
> 
>         if (libct_net_dev_set_mac_addr(nd, "00:11:22:33:44:55"))
> 
>                 return tst_err("Can't set mac");
> 
>  
> 
>                 //Added by Monali
> 
>         if (libct_net_dev_add_ip_addr(nd, "VETH_CT_ADDR"))

I think here is a mistake. You need to remove double quotes arount VETH_CT_ADDR.

You need smth like this:

#define VETH_CT_ADDR "192.168.87.123/24"
...
	if (libct_net_dev_add_ip_addr(nd, VETH_CT_ADDR))

Here is an example
https://github.com/avagin/libct/blob/veth-test/test/ct_net_veth.c

Thanks,
Andrew
> 
>                 return tst_err("Can't set addr");
> 
>  
> 
>         pr = libct_container_spawn_cb(ct, pd, check_ct_net, &ca);
> 
>         if (libct_handle_is_err(pr))
> 
>                 return tst_err("Can't spawn CT");
> 
>  
> 
> …Same as in git
> 
>  
> 
> }
> 

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