rtdel.c

来自「TCP-IP红宝书源代码」· C语言 代码 · 共 48 行

/* rtdel.c - rtdel */

#include <conf.h>
#include <kernel.h>
#include <network.h>

/*------------------------------------------------------------------------
 *  rtdel  -  delete the route with the given net, mask
 *------------------------------------------------------------------------
 */
int
rtdel(IPaddr net, IPaddr mask)
{
	struct	route	*prt, *prev;
	int		hv, i;

	if (!Route.ri_valid)
		return SYSERR;
	wait(Route.ri_mutex);
	if (Route.ri_default &&
	    net == Route.ri_default->rt_net) {
		RTFREE(Route.ri_default);
		Route.ri_default = 0;
		signal(Route.ri_mutex);
		return OK;
	}
	hv = rthash(net);

	prev = NULL;
	for (prt = rttable[hv]; prt; prt = prt->rt_next) {
		if (net == prt->rt_net &&
		    mask == prt->rt_mask)
			break;
		prev = prt;
	}
	if (prt == NULL) {
		signal(Route.ri_mutex);
		return SYSERR;
	}
	if (prev)
		prev->rt_next = prt->rt_next;
	else
		rttable[hv] = prt->rt_next;
	RTFREE(prt);
	signal(Route.ri_mutex);
	return OK;
}