Re: [lwip-users] PPPOS udp error

[parwath . r]

Hi,
   We tried to send more than 250 bytes in udp raw client socket, the 
udp_send is giving succeess and server is not recived any data. is there 
any data limitation for send and receive data. here i have attached log 
PFA. the poolsize  configration is bellow
 #define PBUF_POOL_SIZE                  100
 #define PBUF_POOL_BUFSIZE               1500


please suggest us to how to move forward

thanks
parwath

On 2017-08-01 06:16, Sylvain Rochet wrote:
> Hi,
>
> On Tue, Aug 01, 2017 at 09:10:58AM -0400, Patrick Klos wrote:
> > On 8/1/2017 2:06 AM, address@hidden wrote:
> > >Hi,
> > >  Here i have attached lwipopts.h file for our configuration. I need to
> > >run 4 udp clients on this stack but currently i am running one udp client.
> >
> > I would recommend increasing the number of pbufs (PBUF_POOL_SIZE) and 
> > the
> > size of the heap (MEM_SIZE) and see if your system runs longer?  If 
> > so, that
> > would imply you have a resource issue that you can look for?  If not, 
> > then
> > the problem is probably someplace else?
> >
> > >I am sending data in loop here bellow i have added part of code t
> > >
> > >
> > >int pppudpsenddata(char *buffer, u16_t len) {
> > >    int status;
> > >    struct pbuf* pbuffer;
> > >    pbuffer->next = NULL;
> >
> > If this is your actual code, then you have a HUGE BUG right here! You 
> > are
> > trying to set 'pbuffer->next' BEFORE pbuffer has a valid pointer.  
> > That
> > can't be good!  :o)   (I'm surprised your compiler didn't warn you 
> > that
> > you're using a variable before it has been initialized?!?)
> >
> > Patrick Klos
> > Klos Technologies, Inc.
> >
> > >    pbuffer = pbuf_alloc(PBUF_TRANSPORT, len, PBUF_POOL);
> > >    memcpy(pbuffer->payload, buffer, len);
> > >    pbuffer->len = pbuffer->tot_len = len;
> > >    status = udp_send(sock, pbuffer);
>
> Furthermore pbuffer->len and pbuffer->tot_len are already set by
> pbuf_alloc... overriding them can't be good... you must take time to
> understand how lwIP chained pbuf should be handled. I am confident you
> are leaking pbufs here as well as a buffer overflow.
>
> Sylvain
>
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ppp_log.txt
Description: Text document