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Remove global list of all llinfo_arp entries and use a callout per

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instance expiry of the ARP entries. Since we no longer abuse the IPv4
radix head lock, we can now enter arp_rtrequest() with a lock held on
an arbitrary rt_entry.

Reviewed by:	bms
This commit is contained in:
Gleb Smirnoff 2007-03-22 10:37:53 +00:00
parent c5474b8f18
commit 1daaa65d3f
1 changed files with 23 additions and 50 deletions
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73
sys/netinet/if_ether.c
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@ -78,33 +78,27 @@ SYSCTL_DECL(_net_link_ether);
SYSCTL_NODE(_net_link_ether, PF_INET, inet, CTLFLAG_RW, 0, "");
/* timer values */
static int arpt_prune = (5*60*1); /* walk list every 5 minutes */
static int arpt_keep = (20*60); /* once resolved, good for 20 more minutes */
SYSCTL_INT(_net_link_ether_inet, OID_AUTO, prune_intvl, CTLFLAG_RW,
&arpt_prune, 0, "ARP table prune interval in seconds");
SYSCTL_INT(_net_link_ether_inet, OID_AUTO, max_age, CTLFLAG_RW,
&arpt_keep, 0, "ARP entry lifetime in seconds");
#define rt_expire rt_rmx.rmx_expire
struct llinfo_arp {
LIST_ENTRY(llinfo_arp) la_le;
struct callout la_timer;
struct rtentry *la_rt;
struct mbuf *la_hold; /* last packet until resolved/timeout */
u_short la_preempt; /* countdown for pre-expiry arps */
u_short la_asked; /* # requests sent */
};
static LIST_HEAD(, llinfo_arp) llinfo_arp;
static struct ifqueue arpintrq;
static int arp_allocated;
static int arp_maxtries = 5;
static int useloopback = 1; /* use loopback interface for local traffic */
static int arp_proxyall = 0;
static struct callout arp_callout;
SYSCTL_INT(_net_link_ether_inet, OID_AUTO, maxtries, CTLFLAG_RW,
&arp_maxtries, 0, "ARP resolution attempts before returning error");
@ -126,43 +120,23 @@ static void in_arpinput(struct mbuf *);
#endif
/*
* Timeout routine. Age arp_tab entries periodically.
* Timeout routine.
*/
/* ARGSUSED */
static void
arptimer(void * __unused unused)
arptimer(void *arg)
{
struct llinfo_arp *la, *ola;
struct rtentry *rt = (struct rtentry *)arg;
RADIX_NODE_HEAD_LOCK(rt_tables[AF_INET]);
LIST_FOREACH_SAFE(la, &llinfo_arp, la_le, ola) {
struct rtentry *rt = la->la_rt;
RT_LOCK_ASSERT(rt);
/*
* The lock is needed to close a theoretical race
* between spontaneous expiry and intentional removal.
* We still got an extra reference on rtentry, so can
* safely pass pointers to its contents.
*/
RT_UNLOCK(rt);
RT_LOCK(rt);
if (rt->rt_expire && rt->rt_expire <= time_uptime) {
struct sockaddr_dl *sdl = SDL(rt->rt_gateway);
KASSERT(sdl->sdl_family == AF_LINK, ("sdl_family %d",
sdl->sdl_family));
if (rt->rt_refcnt > 1) {
sdl->sdl_alen = 0;
la->la_preempt = la->la_asked = 0;
RT_UNLOCK(rt);
continue;
}
RT_UNLOCK(rt);
/*
* XXX: LIST_REMOVE() is deep inside rtrequest().
*/
rtrequest(RTM_DELETE, rt_key(rt), NULL, rt_mask(rt), 0,
NULL);
continue;
}
RT_UNLOCK(rt);
}
RADIX_NODE_HEAD_UNLOCK(rt_tables[AF_INET]);
callout_reset(&arp_callout, arpt_prune * hz, arptimer, NULL);
rtrequest(RTM_DELETE, rt_key(rt), NULL, rt_mask(rt), 0, NULL);
}
/*
@ -251,8 +225,8 @@ arp_rtrequest(req, rt, info)
RT_ADDREF(rt);
la->la_rt = rt;
rt->rt_flags |= RTF_LLINFO;
RADIX_NODE_HEAD_LOCK_ASSERT(rt_tables[AF_INET]);
LIST_INSERT_HEAD(&llinfo_arp, la, la_le);
callout_init_mtx(&la->la_timer, &rt->rt_mtx,
CALLOUT_RETURNUNLOCKED);
#ifdef INET
/*
@ -315,13 +289,12 @@ arp_rtrequest(req, rt, info)
break;
case RTM_DELETE:
if (la == 0)
if (la == NULL) /* XXX: at least CARP does this. */
break;
RADIX_NODE_HEAD_LOCK_ASSERT(rt_tables[AF_INET]);
LIST_REMOVE(la, la_le);
RT_REMREF(rt);
rt->rt_llinfo = 0;
callout_stop(&la->la_timer);
rt->rt_llinfo = NULL;
rt->rt_flags &= ~RTF_LLINFO;
RT_REMREF(rt);
if (la->la_hold)
m_freem(la->la_hold);
Free((caddr_t)la);
@ -501,6 +474,7 @@ arpresolve(struct ifnet *ifp, struct rtentry *rt0, struct mbuf *m,
SIN(rt->rt_ifa->ifa_addr)->sin_addr;
rt->rt_expire = time_uptime;
callout_reset(&la->la_timer, hz, arptimer, rt);
la->la_asked++;
RT_UNLOCK(rt);
@ -794,8 +768,10 @@ match:
m->m_pkthdr.len += 8;
th->rcf = trld->trld_rcf;
}
if (rt->rt_expire)
if (rt->rt_expire) {
rt->rt_expire = time_uptime + arpt_keep;
callout_reset(&la->la_timer, hz * arpt_keep, arptimer, rt);
}
la->la_asked = 0;
la->la_preempt = arp_maxtries;
hold = la->la_hold;
@ -997,9 +973,6 @@ arp_init(void)
arpintrq.ifq_maxlen = 50;
mtx_init(&arpintrq.ifq_mtx, "arp_inq", NULL, MTX_DEF);
LIST_INIT(&llinfo_arp);
callout_init(&arp_callout, CALLOUT_MPSAFE);
netisr_register(NETISR_ARP, arpintr, &arpintrq, NETISR_MPSAFE);
callout_reset(&arp_callout, hz, arptimer, NULL);
}
SYSINIT(arp, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, arp_init, 0);