Re: [lwip-devel] SYN flood attack - lwip crash

[Piero 74]

2009/1/30 Kieran Mansley <address@hidden>

On Fri, 2009-01-30 at 16:36 +0100, Piero 74 wrote:

> ...now the problem is "only" how patch this bug...
> (do you agree with me? is it a bug? i'm wrong in same way???)

I wonder if your mail box is overflowing, which might explain why
tcp_accepted never gets called.  Worth checking out.  I seem to recall
that there's a minimum size for the mailbox to ensure everything works
fine, but can't remember the details.

my setting:

/**

 * TCPIP_MBOX_SIZE: The mailbox size for the tcpip thread messages

 * The queue size value itself is platform-dependent, but is passed to

 * sys_mbox_new() when tcpip_init is called.

 */

#define TCPIP_MBOX_SIZE                 30

// piero - ok

/**

 * DEFAULT_UDP_RECVMBOX_SIZE: The mailbox size for the incoming packets on a

 * NETCONN_UDP. The queue size value itself is platform-dependent, but is passed

 * to sys_mbox_new() when the recvmbox is created.

 */

#define DEFAULT_UDP_RECVMBOX_SIZE       30

// piero - ok

/**

 * DEFAULT_TCP_RECVMBOX_SIZE: The mailbox size for the incoming packets on a

 * NETCONN_TCP. The queue size value itself is platform-dependent, but is passed

 * to sys_mbox_new() when the recvmbox is created.

 */

#define DEFAULT_TCP_RECVMBOX_SIZE       30

// piero - ok

/**

 * DEFAULT_ACCEPTMBOX_SIZE: The mailbox size for the incoming connections.

 * The queue size value itself is platform-dependent, but is passed to

 * sys_mbox_new() when the acceptmbox is created.

 */

#define DEFAULT_ACCEPTMBOX_SIZE         10

// piero

 

However, I'm not convinced you've found your bug: you had a problem
without the listen backlog code, so a bug in that code isn't going to
explain what went wrong without it.

"without the listen backlog code" ????

i didn't understand... i'm using backlog ....

what are you saying? sorry....

 

Did you find out what's on the other pcb lists, and what the stats are
for the number of pcbs allocated?

i have few time...

what are you searching exactly???

(i'm trying to provide you some additional info...)

 

Piero