Function add_mfc

freebsd/netinet/ip_mroute.c:1050–1149

* Add an mfc entry */

 * Add an mfc entry
 */
static int
add_mfc(struct mfcctl2 *mfccp)
{
    struct mfc *rt;
    struct rtdetq *rte, *nrte;
    u_long hash = 0;
    u_short nstl;

    VIF_LOCK();
    MFC_LOCK();

    rt = mfc_find(&mfccp->mfcc_origin, &mfccp->mfcc_mcastgrp);

    /* If an entry already exists, just update the fields */
    if (rt) {
	CTR4(KTR_IPMF, "%s: update mfc orig 0x%08x group %lx parent %x",
	    __func__, ntohl(mfccp->mfcc_origin.s_addr),
	    (u_long)ntohl(mfccp->mfcc_mcastgrp.s_addr),
	    mfccp->mfcc_parent);
	update_mfc_params(rt, mfccp);
	MFC_UNLOCK();
	VIF_UNLOCK();
	return (0);
    }

    /*
     * Find the entry for which the upcall was made and update
     */
    nstl = 0;
    hash = MFCHASH(mfccp->mfcc_origin, mfccp->mfcc_mcastgrp);
    LIST_FOREACH(rt, &V_mfchashtbl[hash], mfc_hash) {
	if (in_hosteq(rt->mfc_origin, mfccp->mfcc_origin) &&
	    in_hosteq(rt->mfc_mcastgrp, mfccp->mfcc_mcastgrp) &&
	    !TAILQ_EMPTY(&rt->mfc_stall)) {
		CTR5(KTR_IPMF,
		    "%s: add mfc orig 0x%08x group %lx parent %x qh %p",
		    __func__, ntohl(mfccp->mfcc_origin.s_addr),
		    (u_long)ntohl(mfccp->mfcc_mcastgrp.s_addr),
		    mfccp->mfcc_parent,
		    TAILQ_FIRST(&rt->mfc_stall));
		if (nstl++)
			CTR1(KTR_IPMF, "%s: multiple matches", __func__);

		init_mfc_params(rt, mfccp);
		rt->mfc_expire = 0;	/* Don't clean this guy up */
		V_nexpire[hash]--;

		/* Free queued packets, but attempt to forward them first. */
		TAILQ_FOREACH_SAFE(rte, &rt->mfc_stall, rte_link, nrte) {
			if (rte->ifp != NULL)
				ip_mdq(rte->m, rte->ifp, rt, -1);
			m_freem(rte->m);
			TAILQ_REMOVE(&rt->mfc_stall, rte, rte_link);
			rt->mfc_nstall--;
			free(rte, M_MRTABLE);
		}
	}
    }