static struct radix_node *
in6_deleteroute(void * v_arg, void *netmask_arg, struct radix_node_head *head)
{
struct radix_node *rn;
lck_mtx_assert(rnh_lock, LCK_MTX_ASSERT_OWNED);
rn = rn_delete(v_arg, netmask_arg, head);
if (rn != NULL) {
struct rtentry *rt = (struct rtentry *)rn;
RT_LOCK_SPIN(rt);
if ((rt->rt_flags & RTF_DYNAMIC) != 0)
in6dynroutes--;
RT_UNLOCK(rt);
}
return (rn);
}
/*
* This code is the inverse of in6_clsroute: on first reference, if we
* were managing the route, stop doing so and set the expiration timer
* back off again.
*/
static struct radix_node *
in6_matroute_args(void *v_arg, struct radix_node_head *head,
rn_matchf_t *f, void *w)
{
struct radix_node *rn = rn_match_args(v_arg, head, f, w);
struct rtentry *rt = (struct rtentry *)rn;
/* This is first reference? */
if (rt != NULL) {
RT_LOCK_SPIN(rt);
if (rt->rt_refcnt == 0 && (rt->rt_flags & RTPRF_OURS)) {
rt->rt_flags &= ~RTPRF_OURS;
rt->rt_rmx.rmx_expire = 0;
}
RT_UNLOCK(rt);
}
return (rn);
}
__private_extern__ errno_t
arp_route_to_gateway_route(const struct sockaddr *net_dest, route_t hint0,
route_t *out_route)
{
struct timeval timenow;
route_t rt = hint0, hint = hint0;
errno_t error = 0;
*out_route = NULL;
/*
* Next hop determination. Because we may involve the gateway route
* in addition to the original route, locking is rather complicated.
* The general concept is that regardless of whether the route points
* to the original route or to the gateway route, this routine takes
* an extra reference on such a route. This extra reference will be
* released at the end.
*
* Care must be taken to ensure that the "hint0" route never gets freed
* via rtfree(), since the caller may have stored it inside a struct
* route with a reference held for that placeholder.
*/
if (rt != NULL) {
unsigned int ifindex;
RT_LOCK_SPIN(rt);
ifindex = rt->rt_ifp->if_index;
RT_ADDREF_LOCKED(rt);
if (!(rt->rt_flags & RTF_UP)) {
RT_REMREF_LOCKED(rt);
RT_UNLOCK(rt);
/* route is down, find a new one */
hint = rt = rtalloc1_scoped((struct sockaddr *)
(size_t)net_dest, 1, 0, ifindex);
if (hint != NULL) {
RT_LOCK_SPIN(rt);
ifindex = rt->rt_ifp->if_index;
} else {
senderr(EHOSTUNREACH);
}
}
/*
* We have a reference to "rt" by now; it will either
* be released or freed at the end of this routine.
*/
RT_LOCK_ASSERT_HELD(rt);
if (rt->rt_flags & RTF_GATEWAY) {
struct rtentry *gwrt = rt->rt_gwroute;
struct sockaddr_in gw;
/* If there's no gateway rt, look it up */
if (gwrt == NULL) {
gw = *((struct sockaddr_in *)rt->rt_gateway);
RT_UNLOCK(rt);
goto lookup;
}
/* Become a regular mutex */
RT_CONVERT_LOCK(rt);
/*
* Take gwrt's lock while holding route's lock;
* this is okay since gwrt never points back
* to "rt", so no lock ordering issues.
*/
RT_LOCK_SPIN(gwrt);
if (!(gwrt->rt_flags & RTF_UP)) {
struct rtentry *ogwrt;
rt->rt_gwroute = NULL;
RT_UNLOCK(gwrt);
gw = *((struct sockaddr_in *)rt->rt_gateway);
RT_UNLOCK(rt);
rtfree(gwrt);
lookup:
gwrt = rtalloc1_scoped(
(struct sockaddr *)&gw, 1, 0, ifindex);
RT_LOCK(rt);
/*
* Bail out if the route is down, no route
* to gateway, circular route, or if the
* gateway portion of "rt" has changed.
*/
if (!(rt->rt_flags & RTF_UP) ||
gwrt == NULL || gwrt == rt ||
!equal(SA(&gw), rt->rt_gateway)) {
if (gwrt == rt) {
RT_REMREF_LOCKED(gwrt);
gwrt = NULL;
}
RT_UNLOCK(rt);
if (gwrt != NULL)
rtfree(gwrt);
senderr(EHOSTUNREACH);
}
/* Remove any existing gwrt */
ogwrt = rt->rt_gwroute;
if ((rt->rt_gwroute = gwrt) != NULL)
RT_ADDREF(gwrt);
/* Clean up "rt" now while we can */
if (rt == hint0) {
RT_REMREF_LOCKED(rt);
RT_UNLOCK(rt);
} else {
RT_UNLOCK(rt);
rtfree(rt);
}
rt = gwrt;
/* Now free the replaced gwrt */
if (ogwrt != NULL)
rtfree(ogwrt);
/* If still no route to gateway, bail out */
if (rt == NULL)
senderr(EHOSTUNREACH);
} else {
RT_ADDREF_LOCKED(gwrt);
RT_UNLOCK(gwrt);
/* Clean up "rt" now while we can */
if (rt == hint0) {
RT_REMREF_LOCKED(rt);
RT_UNLOCK(rt);
} else {
RT_UNLOCK(rt);
rtfree(rt);
}
rt = gwrt;
}
/* rt == gwrt; if it is now down, give up */
RT_LOCK_SPIN(rt);
if (!(rt->rt_flags & RTF_UP)) {
RT_UNLOCK(rt);
senderr(EHOSTUNREACH);
}
}
if (rt->rt_flags & RTF_REJECT) {
getmicrotime(&timenow);
if (rt->rt_rmx.rmx_expire == 0 ||
timenow.tv_sec < rt->rt_rmx.rmx_expire) {
RT_UNLOCK(rt);
senderr(rt == hint ? EHOSTDOWN : EHOSTUNREACH);
}
}
/* Become a regular mutex */
RT_CONVERT_LOCK(rt);
/* Caller is responsible for cleaning up "rt" */
*out_route = rt;
}
return (0);
bad:
/* Clean up route (either it is "rt" or "gwrt") */
if (rt != NULL) {
RT_LOCK_SPIN(rt);
if (rt == hint0) {
RT_REMREF_LOCKED(rt);
RT_UNLOCK(rt);
} else {
RT_UNLOCK(rt);
rtfree(rt);
}
}
return (error);
}
