#include "unproute.h"
#include <netinet/udp.h>
#include <netinet/ip_var.h>
#include <netinet/udp_var.h> /* for UDPCTL_xxx constants */
int
main(int argc, char **argv)
{
int mib[5], val;
size_t len;
mib[0] = CTL_NET;
mib[1] = AF_INET;
mib[2] = IPPROTO_UDP;
mib[3] = UDPCTL_CHECKSUM;
len = sizeof(val);
Sysctl(mib, 4, &val, &len, NULL, 0);
printf("udp checksum flag: %d\n", val);
exit(0);
}