ref: 23e378a960f6027f8daba93f34ebeb1ae3d00517
parent: 4b3a0ca15911333d92389daa47220c8742855f1f
author: cinap_lenrek <cinap_lenrek@felloff.net>
date: Wed Sep 28 14:20:20 EDT 2022
arp: move arp expire logic into own function Add arphit() function, handling validation and checking for maximum life-time of the enty as well as copying out the mac address.
--- a/sys/src/9/ip/arp.c
+++ b/sys/src/9/ip/arp.c
@@ -177,6 +177,21 @@
return nil;
}
+static int
+arphit(Arpent *a, uchar *mac, int maclen, Routehint *rh)
+{
+ if(a->state == AOK){
+ memmove(mac, a->mac, maclen);
+ a->utime = NOW;
+ if(a->utime - a->ctime < MAXAGE_TIMER){
+ if(rh != nil)
+ rh->a = a;
+ return 1;
+ }
+ }
+ return 0;
+}
+
/*
* fill in the media address if we have it. Otherwise return an
* Arpent that represents the state of the address resolution FSM
@@ -196,33 +211,29 @@
if(rh != nil
&& (a = rh->a) != nil
- && a->state == AOK
&& a->ifc == ifc
&& a->ifcid == ifc->ifcid
- && ipcmp(ip, a->ip) == 0){
- memmove(mac, a->mac, ifc->m->maclen);
- a->utime = NOW;
- if(a->utime - a->ctime < MAXAGE_TIMER)
- return nil;
- }
+ && ipcmp(ip, a->ip) == 0
+ && arphit(a, mac, ifc->m->maclen, nil))
+ return nil;
rlock(arp);
- if((a = arplookup(arp, ifc, ip)) != nil && a->state == AOK){
- memmove(mac, a->mac, ifc->m->maclen);
- a->utime = NOW;
- if(a->utime - a->ctime < MAXAGE_TIMER){
- if(rh != nil)
- rh->a = a;
- runlock(arp);
- return nil;
- }
+ if((a = arplookup(arp, ifc, ip)) != nil
+ && arphit(a, mac, ifc->m->maclen, rh)){
+ runlock(arp);
+ return nil;
}
if(rh != nil)
rh->a = nil;
runlock(arp);
+
wlock(arp);
if((a = arplookup(arp, ifc, ip)) == nil)
a = newarpent(arp, ip, ifc);
+ else if(arphit(a, mac, ifc->m->maclen, rh)){
+ wunlock(arp);
+ return nil;
+ }
a->state = AWAIT;
a->utime = NOW;
if(bp != nil){