Re: gcc-gethostbyaddr memory leak

[Arthur Gold <agold@bga.com>]

Andrew Wallace wrote:
> 
> I hope this is the correct list, this looks like a gcc problem.  I don't think
> it's a programming question.
Actually, IIRC it's a glibc problem...tht I think is fixed in 2.1.2.

HTH,
--ag
> 
> The following code leaks when it is passed an address that it cannot find.  If
> anybody has any suggestions I would appreciate any help.
> 
> Thanks,
> 
> Andrew
> 
> System info:
> gcc version 2.95.1 19990816
> Linux Redhat v6.0, I'm sorry I can't find the kernel version
> 
> // simple program to demo the leak in gethostbyaddr when a
> // name is not found
> 
> #include <netdb.h>
> #include <sys/socket.h>
> #include <errno.h>
> #include <netinet/in.h>
> #include <arpa/inet.h>
> 
> char* GetAddrName(char* clean_address)
> {
>   static int init_state;
>   struct in_addr ip;
> 
>   if (inet_aton(clean_address, &ip))
>   {
>     struct hostent* hostinfo = gethostbyaddr((char*)&ip, sizeof(ip), AF_INET);
> 
>     if (hostinfo)
>       return hostinfo->h_name;
> 
>     if (h_errno != 1)   // display anything but HOST NOT FOUND
>       printf("ERROR: gethostbyaddr (%s,%d)(%s,%d)(%s)\n",
>           hstrerror(h_errno), h_errno, strerror(errno), errno, clean_address);
> 
>   }  // if
> 
>   else
>     printf("ERROR: address seems invalid: %s\n", clean_address);
> 
>   return NULL;
> }
> 
> int main(int argc, char** argv)
> {
>   int x;
>   char buff[124];
> 
>   for (x = 0; x < 50000; x++)
>   {
>     sprintf(buff,"%d.%d.%d.%d",210,10,3, (random()%254) + 1);
> 
>     printf("%-20.20s %s\n", GetAddrName(buff), buff);
>     if (!(x % 100))
>       sleep(1);
>   }
> }

-- 
Artie Gold, Austin, TX  (finger the cs.utexas.edu account for more info)
mailto:agold@bga.com or mailto:agold@cs.utexas.edu
--
A: Look for a lawyer who speaks Aramaic...about trademark infringement.