From 19e16d220f0adbf899a652dfb1fde2e3a95153e9 Mon Sep 17 00:00:00 2001
From: Hangbin Liu <liuhangbin@gmail.com>
Date: Wed, 1 Apr 2020 14:46:20 +0800
Subject: [PATCH] neigh: support smaller retrans_time settting
Currently, we limited the retrans_time to be greater than HZ/2. i.e.
setting retrans_time less than 500ms will not work. This makes the user
unable to achieve a more accurate control for bonding arp fast failover.
Update the sanity check to HZ/100, which is 10ms, to let users have more
ability on the retrans_time control.
v3: sync the behavior with IPv6 and update all the timer handler
v2: use HZ instead of hard code number
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/core/neighbour.c | 10 ++++++----
net/ipv6/addrconf.c | 7 ++++---
net/ipv6/ndisc.c | 4 ++--
3 files changed, 12 insertions(+), 9 deletions(-)
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 5bf8d22a47ec0..39d37d0ef575b 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -1065,11 +1065,12 @@ static void neigh_timer_handler(struct timer_list *t)
neigh->updated = jiffies;
atomic_set(&neigh->probes, 0);
notify = 1;
- next = now + NEIGH_VAR(neigh->parms, RETRANS_TIME);
+ next = now + max(NEIGH_VAR(neigh->parms, RETRANS_TIME),
+ HZ/100);
}
} else {
/* NUD_PROBE|NUD_INCOMPLETE */
- next = now + NEIGH_VAR(neigh->parms, RETRANS_TIME);
+ next = now + max(NEIGH_VAR(neigh->parms, RETRANS_TIME), HZ/100);
}
if ((neigh->nud_state & (NUD_INCOMPLETE | NUD_PROBE)) &&
@@ -1125,7 +1126,7 @@ int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
neigh->nud_state = NUD_INCOMPLETE;
neigh->updated = now;
next = now + max(NEIGH_VAR(neigh->parms, RETRANS_TIME),
- HZ/2);
+ HZ/100);
neigh_add_timer(neigh, next);
immediate_probe = true;
} else {
@@ -1427,7 +1428,8 @@ void __neigh_set_probe_once(struct neighbour *neigh)
neigh->nud_state = NUD_INCOMPLETE;
atomic_set(&neigh->probes, neigh_max_probes(neigh));
neigh_add_timer(neigh,
- jiffies + NEIGH_VAR(neigh->parms, RETRANS_TIME));
+ jiffies + max(NEIGH_VAR(neigh->parms, RETRANS_TIME),
+ HZ/100));
}
EXPORT_SYMBOL(__neigh_set_probe_once);
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 84a28b539c433..24e319dfb5103 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -1357,7 +1357,7 @@ static int ipv6_create_tempaddr(struct inet6_ifaddr *ifp,
regen_advance = idev->cnf.regen_max_retry *
idev->cnf.dad_transmits *
- NEIGH_VAR(idev->nd_parms, RETRANS_TIME) / HZ;
+ max(NEIGH_VAR(idev->nd_parms, RETRANS_TIME), HZ/100) / HZ;
/* recalculate max_desync_factor each time and update
* idev->desync_factor if it's larger
@@ -4121,7 +4121,8 @@ static void addrconf_dad_work(struct work_struct *w)
ifp->dad_probes--;
addrconf_mod_dad_work(ifp,
- NEIGH_VAR(ifp->idev->nd_parms, RETRANS_TIME));
+ max(NEIGH_VAR(ifp->idev->nd_parms, RETRANS_TIME),
+ HZ/100));
spin_unlock(&ifp->lock);
write_unlock_bh(&idev->lock);
@@ -4527,7 +4528,7 @@ static void addrconf_verify_rtnl(void)
!(ifp->flags&IFA_F_TENTATIVE)) {
unsigned long regen_advance = ifp->idev->cnf.regen_max_retry *
ifp->idev->cnf.dad_transmits *
- NEIGH_VAR(ifp->idev->nd_parms, RETRANS_TIME) / HZ;
+ max(NEIGH_VAR(ifp->idev->nd_parms, RETRANS_TIME), HZ/100) / HZ;
if (age >= ifp->prefered_lft - regen_advance) {
struct inet6_ifaddr *ifpub = ifp->ifpub;
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 6ffa153e51663..1ecd4e9b0bdf0 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -1359,8 +1359,8 @@ static void ndisc_router_discovery(struct sk_buff *skb)
if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
rtime = (rtime*HZ)/1000;
- if (rtime < HZ/10)
- rtime = HZ/10;
+ if (rtime < HZ/100)
+ rtime = HZ/100;
NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime);
in6_dev->tstamp = jiffies;
send_ifinfo_notify = true;
--
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