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Index: head/sys/net/if_llatbl.h
===================================================================
--- head/sys/net/if_llatbl.h
+++ head/sys/net/if_llatbl.h
@@ -79,6 +79,8 @@
int16_t ln_state; /* IPv6 has ND6_LLINFO_NOSTATE == -2 */
uint16_t ln_router;
time_t ln_ntick;
+ time_t lle_remtime; /* Real time remaining */
+ time_t lle_hittime; /* Time when r_skip_req was unset */
int lle_refcnt;
LIST_ENTRY(llentry) lle_chain; /* chain of deleted items */
@@ -222,6 +224,8 @@
size_t lltable_drop_entry_queue(struct llentry *);
void lltable_set_entry_addr(struct ifnet *ifp, struct llentry *lle,
const char *lladdr);
+int lltable_try_set_entry_addr(struct ifnet *ifp, struct llentry *lle,
+ const char *lladdr);
struct llentry *lltable_alloc_entry(struct lltable *llt, u_int flags,
const struct sockaddr *l4addr);
Index: head/sys/net/if_llatbl.c
===================================================================
--- head/sys/net/if_llatbl.c
+++ head/sys/net/if_llatbl.c
@@ -288,6 +288,47 @@
}
/*
+ * Tries to update @lle link-level address.
+ * Since update requires AFDATA WLOCK, function
+ * drops @lle lock, acquires AFDATA lock and then acquires
+ * @lle lock to maintain lock order.
+ *
+ * Returns 1 on success.
+ */
+int
+lltable_try_set_entry_addr(struct ifnet *ifp, struct llentry *lle,
+ const char *lladdr)
+{
+
+ /* Perform real LLE update */
+ /* use afdata WLOCK to update fields */
+ LLE_WLOCK_ASSERT(lle);
+ LLE_ADDREF(lle);
+ LLE_WUNLOCK(lle);
+ IF_AFDATA_WLOCK(ifp);
+ LLE_WLOCK(lle);
+
+ /*
+ * Since we droppped LLE lock, other thread might have deleted
+ * this lle. Check and return
+ */
+ if ((lle->la_flags & LLE_DELETED) != 0) {
+ IF_AFDATA_WUNLOCK(ifp);
+ LLE_FREE_LOCKED(lle);
+ return (0);
+ }
+
+ /* Update data */
+ lltable_set_entry_addr(ifp, lle, lladdr);
+
+ IF_AFDATA_WUNLOCK(ifp);
+
+ LLE_REMREF(lle);
+
+ return (1);
+}
+
+/*
*
* Performes generic cleanup routines and frees lle.
*
Index: head/sys/netinet6/in6.c
===================================================================
--- head/sys/netinet6/in6.c
+++ head/sys/netinet6/in6.c
@@ -2064,6 +2064,7 @@
LLE_WUNLOCK(lle);
LLE_LOCK_DESTROY(lle);
+ LLE_REQ_DESTROY(lle);
free(lle, M_LLTABLE);
}
@@ -2080,6 +2081,7 @@
lle->base.lle_refcnt = 1;
lle->base.lle_free = in6_lltable_destroy_lle;
LLE_LOCK_INIT(&lle->base);
+ LLE_REQ_INIT(&lle->base);
callout_init(&lle->base.lle_timer, 1);
return (&lle->base);
@@ -2288,6 +2290,13 @@
if (lle == NULL)
return (NULL);
+ KASSERT((flags & (LLE_UNLOCKED|LLE_EXCLUSIVE)) !=
+ (LLE_UNLOCKED|LLE_EXCLUSIVE),("wrong lle request flags: 0x%X",
+ flags));
+
+ if (flags & LLE_UNLOCKED)
+ return (lle);
+
if (flags & LLE_EXCLUSIVE)
LLE_WLOCK(lle);
else
@@ -2350,8 +2359,8 @@
sdl->sdl_index = ifp->if_index;
sdl->sdl_type = ifp->if_type;
bcopy(&lle->ll_addr, LLADDR(sdl), ifp->if_addrlen);
- ndpc.rtm.rtm_rmx.rmx_expire =
- lle->la_flags & LLE_STATIC ? 0 : lle->la_expire;
+ ndpc.rtm.rtm_rmx.rmx_expire = lle->la_expire +
+ lle->lle_remtime / hz;
ndpc.rtm.rtm_flags |= (RTF_HOST | RTF_LLDATA);
if (lle->la_flags & LLE_STATIC)
ndpc.rtm.rtm_flags |= RTF_STATIC;
Index: head/sys/netinet6/nd6.c
===================================================================
--- head/sys/netinet6/nd6.c
+++ head/sys/netinet6/nd6.c
@@ -542,6 +542,107 @@
}
/*
+ * Checks if we need to switch from STALE state.
+ *
+ * RFC 4861 requires switching from STALE to DELAY state
+ * on first packet matching entry, waiting V_nd6_delay and
+ * transition to PROBE state (if upper layer confirmation was
+ * not received).
+ *
+ * This code performs a bit differently:
+ * On packet hit we don't change state (but desired state
+ * can be guessed by control plane). However, after V_nd6_delay
+ * seconds code will transition to PROBE state (so DELAY state
+ * is kinda skipped in most situations).
+ *
+ * Typically, V_nd6_gctimer is bigger than V_nd6_delay, so
+ * we perform the following upon entering STALE state:
+ *
+ * 1) Arm timer to run each V_nd6_delay seconds to make sure that
+ * if packet was transmitted at the start of given interval, we
+ * would be able to switch to PROBE state in V_nd6_delay seconds
+ * as user expects.
+ *
+ * 2) Reschedule timer until original V_nd6_gctimer expires keeping
+ * lle in STALE state (remaining timer value stored in lle_remtime).
+ *
+ * 3) Reschedule timer if packet was transmitted less that V_nd6_delay
+ * seconds ago.
+ *
+ * Returns non-zero value if the entry is still STALE (storing
+ * the next timer interval in @pdelay).
+ *
+ * Returns zero value if original timer expired or we need to switch to
+ * PROBE (store that in @do_switch variable).
+ */
+static int
+nd6_is_stale(struct llentry *lle, long *pdelay, int *do_switch)
+{
+ int nd_delay, nd_gctimer, r_skip_req;
+ time_t lle_hittime;
+ long delay;
+
+ *do_switch = 0;
+ nd_gctimer = V_nd6_gctimer;
+ nd_delay = V_nd6_delay;
+
+ LLE_REQ_LOCK(lle);
+ r_skip_req = lle->r_skip_req;
+ lle_hittime = lle->lle_hittime;
+ LLE_REQ_UNLOCK(lle);
+
+ if (r_skip_req > 0) {
+
+ /*
+ * Nonzero r_skip_req value was set upon entering
+ * STALE state. Since value was not changed, no
+ * packets were passed using this lle. Ask for
+ * timer reschedule and keep STALE state.
+ */
+ delay = (long)(MIN(nd_gctimer, nd_delay));
+ delay *= hz;
+ if (lle->lle_remtime > delay)
+ lle->lle_remtime -= delay;
+ else {
+ delay = lle->lle_remtime;
+ lle->lle_remtime = 0;
+ }
+
+ if (delay == 0) {
+
+ /*
+ * The original ng6_gctime timeout ended,
+ * no more rescheduling.
+ */
+ return (0);
+ }
+
+ *pdelay = delay;
+ return (1);
+ }
+
+ /*
+ * Packet received. Verify timestamp
+ */
+ delay = (long)(time_uptime - lle_hittime);
+ if (delay < nd_delay) {
+
+ /*
+ * V_nd6_delay still not passed since the first
+ * hit in STALE state.
+ * Reshedule timer and return.
+ */
+ *pdelay = (long)(nd_delay - delay) * hz;
+ return (1);
+ }
+
+ /* Request switching to probe */
+ *do_switch = 1;
+ return (0);
+}
+
+
+/*
* Switch @lle state to new state optionally arming timers.
*
* Set noinline to be dtrace-friendly
@@ -550,9 +651,11 @@
nd6_llinfo_setstate(struct llentry *lle, int newstate)
{
struct ifnet *ifp;
- long delay;
+ int nd_gctimer, nd_delay;
+ long delay, remtime;
delay = 0;
+ remtime = 0;
switch (newstate) {
case ND6_LLINFO_INCOMPLETE:
@@ -566,7 +669,19 @@
}
break;
case ND6_LLINFO_STALE:
- delay = (long)V_nd6_gctimer * hz;
+
+ /*
+ * Notify fast path that we want to know if any packet
+ * is transmitted by setting r_skip_req.
+ */
+ LLE_REQ_LOCK(lle);
+ lle->r_skip_req = 1;
+ LLE_REQ_UNLOCK(lle);
+ nd_delay = V_nd6_delay;
+ nd_gctimer = V_nd6_gctimer;
+
+ delay = (long)(MIN(nd_gctimer, nd_delay)) * hz;
+ remtime = (long)nd_gctimer * hz - delay;
break;
case ND6_LLINFO_DELAY:
lle->la_asked = 0;
@@ -577,6 +692,7 @@
if (delay > 0)
nd6_llinfo_settimer_locked(lle, delay);
+ lle->lle_remtime = remtime;
lle->ln_state = newstate;
}
@@ -592,7 +708,8 @@
struct in6_addr *dst, *pdst, *psrc, src;
struct ifnet *ifp;
struct nd_ifinfo *ndi = NULL;
- int send_ns;
+ int do_switch, send_ns;
+ long delay;
KASSERT(arg != NULL, ("%s: arg NULL", __func__));
ln = (struct llentry *)arg;
@@ -680,13 +797,35 @@
break;
case ND6_LLINFO_STALE:
- /* Garbage Collection(RFC 2461 5.3) */
- if (!ND6_LLINFO_PERMANENT(ln)) {
- EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_EXPIRED);
- nd6_free(ln, 1);
- ln = NULL;
+ if (nd6_is_stale(ln, &delay, &do_switch) != 0) {
+
+ /*
+ * No packet has used this entry and GC timeout
+ * has not been passed. Reshedule timer and
+ * return.
+ */
+ nd6_llinfo_settimer_locked(ln, delay);
+ break;
}
- break;
+
+ if (do_switch == 0) {
+
+ /*
+ * GC timer has ended and entry hasn't been used.
+ * Run Garbage collector (RFC 4861, 5.3)
+ */
+ if (!ND6_LLINFO_PERMANENT(ln)) {
+ EVENTHANDLER_INVOKE(lle_event, ln,
+ LLENTRY_EXPIRED);
+ nd6_free(ln, 1);
+ ln = NULL;
+ }
+ break;
+ }
+
+ /* Entry has been used AND delay timer has ended. */
+
+ /* FALLTHROUGH */
case ND6_LLINFO_DELAY:
if (ndi && (ndi->flags & ND6_IFF_PERFORMNUD) != 0) {
@@ -1796,7 +1935,11 @@
* Record source link-layer address
* XXX is it dependent to ifp->if_type?
*/
- lltable_set_entry_addr(ifp, ln, lladdr);
+ if (lltable_try_set_entry_addr(ifp, ln, lladdr) == 0) {
+ /* Entry was deleted */
+ return;
+ }
+
nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
@@ -1996,31 +2139,25 @@
}
IF_AFDATA_RLOCK(ifp);
- ln = nd6_lookup(&dst6->sin6_addr, 0, ifp);
- IF_AFDATA_RUNLOCK(ifp);
-
- /*
- * Perform fast path for the following cases:
- * 1) lle state is REACHABLE
- * 2) lle state is DELAY (NS message sent)
- *
- * Every other case involves lle modification, so we handle
- * them separately.
- */
- if (ln == NULL || (ln->ln_state != ND6_LLINFO_REACHABLE &&
- ln->ln_state != ND6_LLINFO_DELAY)) {
- /* Fall back to slow processing path */
- if (ln != NULL)
- LLE_RUNLOCK(ln);
- return (nd6_resolve_slow(ifp, m, dst6, desten, pflags));
+ ln = nd6_lookup(&dst6->sin6_addr, LLE_UNLOCKED, ifp);
+ if (ln != NULL && (ln->r_flags & RLLE_VALID) != 0) {
+ /* Entry found, let's copy lle info */
+ bcopy(&ln->ll_addr, desten, ifp->if_addrlen);
+ if (pflags != NULL)
+ *pflags = LLE_VALID | (ln->r_flags & RLLE_IFADDR);
+ /* Check if we have feedback request from nd6 timer */
+ if (ln->r_skip_req != 0) {
+ LLE_REQ_LOCK(ln);
+ ln->r_skip_req = 0; /* Notify that entry was used */
+ ln->lle_hittime = time_uptime;
+ LLE_REQ_UNLOCK(ln);
+ }
+ IF_AFDATA_RUNLOCK(ifp);
+ return (0);
}
+ IF_AFDATA_RUNLOCK(ifp);
-
- bcopy(&ln->ll_addr, desten, ifp->if_addrlen);
- if (pflags != NULL)
- *pflags = ln->la_flags;
- LLE_RUNLOCK(ln);
- return (0);
+ return (nd6_resolve_slow(ifp, m, dst6, desten, pflags));
}
Index: head/sys/netinet6/nd6_nbr.c
===================================================================
--- head/sys/netinet6/nd6_nbr.c
+++ head/sys/netinet6/nd6_nbr.c
@@ -765,7 +765,10 @@
/*
* Record link-layer address, and update the state.
*/
- lltable_set_entry_addr(ifp, ln, lladdr);
+ if (lltable_try_set_entry_addr(ifp, ln, lladdr) == 0) {
+ ln = NULL;
+ goto freeit;
+ }
EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
if (is_solicited)
nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE);
@@ -831,7 +834,12 @@
* Update link-local address, if any.
*/
if (lladdr != NULL) {
- lltable_set_entry_addr(ifp, ln, lladdr);
+ int ret;
+ ret = lltable_try_set_entry_addr(ifp, ln,lladdr);
+ if (ret == 0) {
+ ln = NULL;
+ goto freeit;
+ }
EVENTHANDLER_INVOKE(lle_event, ln,
LLENTRY_RESOLVED);
}

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