dtrace discuss - Oct 2008 - Looking for: Coding example for inet_ntoa equiv for user-land IP addresses

I am writing a Dtrace script for a context (Solaris 10) in which the 
built-in functions inet_ntoa and inet_ntoa6 are not available.   The 
input is a userland address to a sockddr_in structure.   

Does anyone have a pointer to a working example of D code that takes a 
userland pointer to a sockaddr or ip address, dereferences it using 
copyin, and formats it using strjoin into "dotted decimal" form?  

The closest I have found is the magic in Brendan''s tcpsnoop to do 
something similar with the kernel-side IP addresses.   This is useful.  
I am hoping for something even closer to what I need.

Peter

Peter,

Just backport the inet_ntoa() and inet_ntoa6() subroutines. I don''t
think
it''s worth faking something up.

Adam

On Wed, Oct 22, 2008 at 05:03:09PM -0400, Peter Cudhea
wrote:
> I am writing a Dtrace script for a context (Solaris 10) in which the 
> built-in functions inet_ntoa and inet_ntoa6 are not available.   The 
> input is a userland address to a sockddr_in structure.   
> 
> Does anyone have a pointer to a working example of D code that takes a 
> userland pointer to a sockaddr or ip address, dereferences it using 
> copyin, and formats it using strjoin into "dotted decimal" form?
> 
> The closest I have found is the magic in Brendan''s tcpsnoop to do 
> something similar with the kernel-side IP addresses.   This is useful.  
> I am hoping for something even closer to what I need.
> 
> Peter
> _______________________________________________
> dtrace-discuss mailing list
> dtrace-discuss at opensolaris.org
-- 
Adam Leventhal, Fishworks                     http://blogs.sun.com/ahl

Hi,

Adam - has it been actually backported yet? It doesn''t look like it
has.


btw: as a workaround one might for example do:

<pre>
syscall::getpeername:entry
/ pid == $1 /
{
  self->in = 1;

  self->arg0 = arg0; /* int s */
  self->arg1 = arg1; /* struct sockaddr * */
  self->arg2 = arg2; /* size_t len */
}

<pre>
syscall::getpeername:return
/ self->in /
{
  this->len = *(socklen_t *) copyin((uintptr_t)self->arg2,
sizeof(socklen_t));
  this->socks = (struct sockaddr *) copyin((uintptr_t)self->arg1,
this->len);
  this->hport = (uint_t)(this->socks->sa_data[0]);
  this->lport = (uint_t)(this->socks->sa_data[1]);
  this->hport <<= 8;
  this->port = this->hport + this->lport;

  this->a1 = lltostr((uint_t)this->socks->sa_data[2]);
  this->a2 = lltostr((uint_t)this->socks->sa_data[3]);
  this->a3 = lltostr((uint_t)this->socks->sa_data[4]);
  this->a4 = lltostr((uint_t)this->socks->sa_data[5]);
  this->s1 = strjoin(this->a1, ".");
  this->s2 = strjoin(this->s1, this->a2);
  this->s1 = strjoin(this->s2, ".");
  this->s2 = strjoin(this->s1, this->a3);
  this->s1 = strjoin(this->s2, ".");

  this->client_ip = strjoin(this->s1, this->a4);
</pre>
-- 
Robert Milkowski
http://milek.blogspot.com
-- 
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