Re: set/getsockopt SO_LINGER problem

David Laight wrote:

>On Wed, Dec 06, 2006 at 01:03:56PM +0530, Prasanta Sadhukhan wrote:
>  
>
>>Hi,
>>
>>I am trying to use get/setsockopt for SO_LINGER option but am facing a 
>>problem
>>I used setsockopt with opt as SO_LINGER passing linger structure with 
>>l_onoff as 1 and l_linger as 65535
>>but when I try to get back through getsockopt, I am getting l_onoff as 
>>128 and l_linger as -1.
>>For other values of l_linger (like 1, 2, 10) during set, though I get 
>>l_onoff as 128 but l_linger is returned correctly
>>    
>>
>
>I suspect this has something to do with:
>    /usr/include/sys/socketvar.h:   short    so_linger;
>and:
>    /usr/include/sys/socket.h: #define SO_LINGER     0x0080
>
>	David
>
>  
>
I have attached a program that shows the problem. Is it a known issue 
with NetBSD3.0?

Regards
Prasanta

#include <stdio.h>
#include <sys/socket.h>

void testlinger();

int main(int argc, char *argv[])
{
	testlinger();
}

void testlinger()
{
	int fd, ret, optlen;
	union {
		int i;
		struct linger ling;
	} optval;
	void *result;
	fd = socket(PF_INET, SOCK_DGRAM, 0);
	printf("socket fd %d\n", fd);
	
	struct linger ling;
	optval.ling.l_onoff = 1;
	optval.ling.l_linger = 65535;
	optlen = sizeof(optval.ling);
	ret = setsockopt(fd, SOL_SOCKET, SO_LINGER, (const void *)&optval, optlen);
	printf("setsockopt retval %d, optlen %d\n", ret,optlen);

	ret = getsockopt(fd, SOL_SOCKET, SO_LINGER, result, &optlen);
	printf("getsockopt retval %d\n", ret);
	printf("get linger onoff %d, linger value %d, optlen %d\n",
			((struct linger*)result)->l_onoff,
			((struct linger*)result)->l_linger, optlen);
}