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devip: cache arp entry in Routehint

Browse source 
Instead of having to do an arp hash table lookup for each
outgoing ip packet, forward the Routehint pointer to the
medium's bwrite() function and let it cache the arp entry
pointer.

This avoids route and arp hash table lookups for tcp, il
and connection oriented udp.

It also allows us to avoid multiple route and arp table
lookups for the retransmits once an arp/neighbour solicitation
response arrives.
This commit is contained in:
cinap_lenrek 2021-10-09 18:26:16 +00:00
parent d280f411f6
commit 1a6324970d
11 changed files with 76 additions and 46 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

45
sys/src/9/ip/arp.c
View file

@ -19,6 +19,8 @@ enum
AOK = 1,
AWAIT = 2,
MAXAGE_TIMER = 15*60*1000,
};
char *arpstate[] =
@ -182,7 +184,7 @@ arplookup(Arp *arp, Ipifc *ifc, uchar *ip)
* waiting for ip->mac to be resolved.
*/
Arpent*
arpget(Arp *arp, Block *bp, int version, Ipifc *ifc, uchar *ip, uchar *mac)
arpget(Arp *arp, Block *bp, int version, Ipifc *ifc, uchar *ip, uchar *mac, Routehint *rh)
{
uchar v6ip[IPaddrlen];
Arpent *a;
@ -191,15 +193,32 @@ arpget(Arp *arp, Block *bp, int version, Ipifc *ifc, uchar *ip, uchar *mac)
v4tov6(v6ip, ip);
ip = v6ip;
}
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;
}
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 < 15*60*1000){
if(a->utime - a->ctime < MAXAGE_TIMER){
if(rh != nil)
rh->a = a;
runlock(arp);
return nil;
}
}
if(rh != nil)
rh->a = nil;
runlock(arp);
wlock(arp);
if((a = arplookup(arp, ifc, ip)) == nil)
@ -269,11 +288,11 @@ arprelease(Arp *arp, Arpent*)
* called with arp locked
*/
Block*
arpresolve(Arp *arp, Arpent *a, Medium *type, uchar *mac)
arpresolve(Arp *arp, Arpent *a, uchar *mac, Routehint *rh)
{
Block *bp;
memmove(a->mac, mac, type->maclen);
memmove(a->mac, mac, a->ifc->m->maclen);
if(a->state == AWAIT) {
rxmtunchain(arp, a);
a->rxtsrem = 0;
@ -282,6 +301,8 @@ arpresolve(Arp *arp, Arpent *a, Medium *type, uchar *mac)
a->hold = a->last = nil;
a->ctime = a->utime = NOW;
a->state = AOK;
if(rh != nil)
rh->a = a;
wunlock(arp);
return bp;
@ -290,6 +311,7 @@ arpresolve(Arp *arp, Arpent *a, Medium *type, uchar *mac)
int
arpenter(Fs *fs, int version, uchar *ip, uchar *mac, int n, uchar *ia, Ipifc *ifc, int refresh)
{
Routehint rh;
uchar v6ip[IPaddrlen];
Block *bp, *next;
Arpent *a;
@ -299,14 +321,16 @@ arpenter(Fs *fs, int version, uchar *ip, uchar *mac, int n, uchar *ia, Ipifc *if
if(ifc->m == nil || ifc->m->maclen != n || ifc->m->maclen == 0)
return -1;
rh.r = nil;
rh.a = nil;
switch(version){
case V4:
r = v4lookup(fs, ip, ia, nil);
r = v4lookup(fs, ip, ia, &rh);
v4tov6(v6ip, ip);
ip = v6ip;
break;
case V6:
r = v6lookup(fs, ip, ia, nil);
r = v6lookup(fs, ip, ia, &rh);
break;
default:
panic("arpenter: version %d", version);
@ -326,9 +350,9 @@ arpenter(Fs *fs, int version, uchar *ip, uchar *mac, int n, uchar *ia, Ipifc *if
}
a = newarpent(arp, ip, ifc);
}
bp = arpresolve(arp, a, mac, &rh); /* unlocks arp */
if(version == V4)
ip += IPv4off;
bp = arpresolve(arp, a, ifc->m, mac); /* unlocks arp */
for(; bp != nil; bp = next){
next = bp->list;
bp->list = nil;
@ -336,7 +360,7 @@ arpenter(Fs *fs, int version, uchar *ip, uchar *mac, int n, uchar *ia, Ipifc *if
freeblistchain(next);
break;
}
ipifcoput(ifc, bp, version, ip);
ipifcoput(ifc, bp, version, ip, &rh);
poperror();
}
return 1;
@ -496,8 +520,9 @@ arpread(Arp *arp, char *s, ulong offset, int len)
}
void
ndpsendsol(Fs *f, Ipifc *ifc, Arpent *a)
ndpsendsol(Fs *f, Arpent *a)
{
Ipifc *ifc = a->ifc;
uchar targ[IPaddrlen], src[IPaddrlen];
if(a->rxtsrem == 0)
@ -538,7 +563,7 @@ rxmt(Arp *arp)
while((a = arp->rxmt[0]) != nil && NOW - a->ctime > 3*RETRANS_TIMER/4){
if(a->rxtsrem > 0 && (ifc = a->ifc) != nil && canrlock(ifc)){
if(a->ifcid == ifc->ifcid){
ndpsendsol(arp->f, ifc, a); /* unlocks arp */
ndpsendsol(arp->f, a); /* unlocks arp */
runlock(ifc);
wlock(arp);

1
sys/src/9/ip/devip.c
View file

@ -1332,6 +1332,7 @@ retry:
c->state = Idle;
ipmove(c->laddr, IPnoaddr);
ipmove(c->raddr, IPnoaddr);
c->a = nil;
c->r = nil;
c->rgen = 0;
c->lport = 0;

31
sys/src/9/ip/ethermedium.c
View file

@ -21,12 +21,12 @@ static void etherread4(void *a);
static void etherread6(void *a);
static void etherbind(Ipifc *ifc, int argc, char **argv);
static void etherunbind(Ipifc *ifc);
static void etherbwrite(Ipifc *ifc, Block *bp, int version, uchar *ip);
static void etherbwrite(Ipifc *ifc, Block *bp, int version, uchar *ip, Routehint *rh);
static void etheraddmulti(Ipifc *ifc, uchar *a, uchar *ia);
static void etherremmulti(Ipifc *ifc, uchar *a, uchar *ia);
static void etherareg(Fs *f, Ipifc *ifc, Iplifc *lifc, uchar *ip);
static Block* multicastarp(Fs *f, Arpent *a, Medium*, uchar *mac);
static void sendarpreq(Ipifc *ifc, Arpent *a);
static Block* multicastarp(Fs *f, Arpent *a, uchar *mac, Routehint *rh);
static void sendarpreq(Fs *f, Arpent *a);
static int multicastea(uchar *ea, uchar *ip);
static void recvarpproc(void*);
static void etherpref2addr(uchar *pref, uchar *ea);
@ -253,7 +253,7 @@ etherunbind(Ipifc *ifc)
* called by ipoput with a single block to write with ifc rlock'd
*/
static void
etherbwrite(Ipifc *ifc, Block *bp, int version, uchar *ip)
etherbwrite(Ipifc *ifc, Block *bp, int version, uchar *ip, Routehint *rh)
{
Etherhdr *eh;
Arpent *a;
@ -261,22 +261,22 @@ etherbwrite(Ipifc *ifc, Block *bp, int version, uchar *ip)
Etherrock *er = ifc->arg;
/* get mac address of destination */
a = arpget(er->f->arp, bp, version, ifc, ip, mac);
a = arpget(er->f->arp, bp, version, ifc, ip, mac, rh);
if(a != nil){
/* check for broadcast or multicast */
bp = multicastarp(er->f, a, ifc->m, mac);
bp = multicastarp(er->f, a, mac, rh);
if(bp == nil){
/* don't do anything if it's been less than a second since the last */
if(a->utime - a->ctime < RETRANS_TIMER){
arprelease(er->f->arp, a);
arprelease(er->f->arp, a); /* unlocks arp */
return;
}
switch(version){
case V4:
sendarpreq(ifc, a); /* unlocks arp */
sendarpreq(er->f, a); /* unlocks arp */
break;
case V6:
ndpsendsol(er->f, ifc, a); /* unlocks arp */
ndpsendsol(er->f, a); /* unlocks arp */
break;
default:
panic("etherbwrite: version %d", version);
@ -440,16 +440,17 @@ etherremmulti(Ipifc *ifc, uchar *a, uchar *)
* (only v4, v6 uses the neighbor discovery, rfc1970)
*/
static void
sendarpreq(Ipifc *ifc, Arpent *a)
sendarpreq(Fs *f, Arpent *a)
{
int n;
Block *bp;
Etherarp *e;
Ipifc *ifc = a->ifc;
Etherrock *er = ifc->arg;
uchar targ[IPv4addrlen], src[IPv4addrlen];
memmove(targ, a->ip+IPv4off, IPv4addrlen);
arpcontinue(er->f->arp, a);
arpcontinue(f->arp, a);
if(!ipv4local(ifc, src, 0, targ))
return;
@ -668,19 +669,19 @@ multicastea(uchar *ea, uchar *ip)
* IP address.
*/
static Block*
multicastarp(Fs *f, Arpent *a, Medium *medium, uchar *mac)
multicastarp(Fs *f, Arpent *a, uchar *mac, Routehint *rh)
{
/* is it broadcast? */
if(ipforme(f, a->ip) == Rbcast){
memset(mac, 0xff, medium->maclen);
return arpresolve(f->arp, a, medium, mac);
memset(mac, 0xff, a->ifc->m->maclen);
return arpresolve(f->arp, a, mac, rh);
}
/* if multicast, fill in mac */
switch(multicastea(mac, a->ip)){
case V4:
case V6:
return arpresolve(f->arp, a, medium, mac);
return arpresolve(f->arp, a, mac, rh);
}
/* let arp take care of it */

7
sys/src/9/ip/ip.c
View file

@ -153,7 +153,7 @@ ipoput4(Fs *f, Block *bp, int gating, int ttl, int tos, Routehint *rh)
eh->cksum[1] = 0;
hnputs(eh->cksum, ipcsum(&eh->vihl));
ipifcoput(ifc, bp, V4, gate);
ipifcoput(ifc, bp, V4, gate, rh);
runlock(ifc);
poperror();
return 0;
@ -237,7 +237,7 @@ ipoput4(Fs *f, Block *bp, int gating, int ttl, int tos, Routehint *rh)
feh->cksum[1] = 0;
hnputs(feh->cksum, ipcsum(&feh->vihl));
ipifcoput(ifc, nb, V4, gate);
ipifcoput(ifc, nb, V4, gate, rh);
ip->stats[FragCreates]++;
}
ip->stats[FragOKs]++;
@ -308,8 +308,8 @@ ipiput4(Fs *f, Ipifc *ifc, Block *bp)
/* route */
v4tov6(v6dst, h->dst);
if(!ipforme(f, v6dst)) {
Route *r;
Routehint rh;
Route *r;
Ipifc *nifc;
if(!ip->iprouting)
@ -317,6 +317,7 @@ ipiput4(Fs *f, Ipifc *ifc, Block *bp)
/* don't forward to source's network */
rh.r = nil;
rh.a = nil;
r = v4lookup(f, h->dst, h->src, &rh);
if(r == nil || (nifc = r->ifc) == nil
|| (nifc == ifc && !ifc->reflect)){

15
sys/src/9/ip/ip.h
View file

@ -168,6 +168,7 @@ struct Routehint
{
Route *r; /* last route used */
ulong rgen; /* routetable generation for *r */
Arpent *a; /* last arp entry used */
};
/*
@ -232,7 +233,7 @@ struct Medium
int maclen; /* mac address length */
void (*bind)(Ipifc*, int, char**);
void (*unbind)(Ipifc*);
void (*bwrite)(Ipifc *ifc, Block *b, int version, uchar *ip);
void (*bwrite)(Ipifc *ifc, Block *b, int version, uchar *ip, Routehint *rh);
/* for arming interfaces to receive multicast */
void (*addmulti)(Ipifc *ifc, uchar *a, uchar *ia);
@ -565,8 +566,8 @@ struct Route
extern void addroute(Fs *f, uchar *a, uchar *mask, uchar *s, uchar *smask, uchar *gate, int type, Ipifc *ifc, char *tag);
extern void remroute(Fs *f, uchar *a, uchar *mask, uchar *s, uchar *smask, uchar *gate, int type, Ipifc *ifc, char *tag);
extern Route* v4lookup(Fs *f, uchar *a, uchar *s, Routehint *h);
extern Route* v6lookup(Fs *f, uchar *a, uchar *s, Routehint *h);
extern Route* v4lookup(Fs *f, uchar *a, uchar *s, Routehint *rh);
extern Route* v6lookup(Fs *f, uchar *a, uchar *s, Routehint *rh);
extern Route* v4source(Fs *f, uchar *a, uchar *s);
extern Route* v6source(Fs *f, uchar *a, uchar *s);
extern long routeread(Fs *f, char*, ulong, int);
@ -611,12 +612,12 @@ struct Arpent
extern void arpinit(Fs*);
extern int arpread(Arp*, char*, ulong, int);
extern int arpwrite(Fs*, char*, int);
extern Arpent* arpget(Arp*, Block *bp, int version, Ipifc *ifc, uchar *ip, uchar *h);
extern Arpent* arpget(Arp*, Block *bp, int version, Ipifc *ifc, uchar *ip, uchar *mac, Routehint *rh);
extern void arprelease(Arp*, Arpent *a);
extern void arpcontinue(Arp*, Arpent *a);
extern Block* arpresolve(Arp*, Arpent *a, Medium *type, uchar *mac);
extern Block* arpresolve(Arp*, Arpent *a, uchar *mac, Routehint *rh);
extern int arpenter(Fs*, int version, uchar *ip, uchar *mac, int n, uchar *ia, Ipifc *ifc, int refresh);
extern void ndpsendsol(Fs*, Ipifc*, Arpent*);
extern void ndpsendsol(Fs*, Arpent*);
/*
* ipaux.c
@ -661,7 +662,7 @@ extern Medium pktmedium;
*/
extern Medium* ipfindmedium(char *name);
extern void addipmedium(Medium *med);
extern void ipifcoput(Ipifc *ifc, Block *bp, int version, uchar *ip);
extern void ipifcoput(Ipifc *ifc, Block *bp, int version, uchar *ip, Routehint *rh);
extern int ipforme(Fs*, uchar *addr);
extern int ipismulticast(uchar *ip);
extern Ipifc* findipifc(Fs*, uchar *local, uchar *remote, int type);

4
sys/src/9/ip/ipifc.c
View file

@ -347,7 +347,7 @@ ipifcsetspeed(Ipifc *ifc, int speed)
}
void
ipifcoput(Ipifc *ifc, Block *bp, int version, uchar *ip)
ipifcoput(Ipifc *ifc, Block *bp, int version, uchar *ip, Routehint *rh)
{
if(ifc->speed){
ulong now = MACHP(0)->ticks;
@ -363,7 +363,7 @@ ipifcoput(Ipifc *ifc, Block *bp, int version, uchar *ip)
}
bp = concatblock(bp);
ifc->load += BLEN(bp);
ifc->m->bwrite(ifc, bp, version, ip);
ifc->m->bwrite(ifc, bp, version, ip, rh);
}

7
sys/src/9/ip/ipv6.c
View file

@ -99,7 +99,7 @@ ipoput6(Fs *f, Block *bp, int gating, int ttl, int tos, Routehint *rh)
medialen = ifc->maxtu - ifc->m->hsize;
if(len <= medialen) {
hnputs(eh->ploadlen, len - IP6HDR);
ipifcoput(ifc, bp, V6, gate);
ipifcoput(ifc, bp, V6, gate, rh);
runlock(ifc);
poperror();
return 0;
@ -195,7 +195,7 @@ ipoput6(Fs *f, Block *bp, int gating, int ttl, int tos, Routehint *rh)
if(xp->rp == xp->wp)
xp = xp->next;
}
ipifcoput(ifc, nb, V6, gate);
ipifcoput(ifc, nb, V6, gate, rh);
ip->stats[FragCreates]++;
}
ip->stats[FragOKs]++;
@ -252,8 +252,8 @@ ipiput6(Fs *f, Ipifc *ifc, Block *bp)
/* route */
if(!ipforme(f, h->dst)) {
Route *r;
Routehint rh;
Route *r;
Ipifc *nifc;
if(!ip->iprouting)
@ -268,6 +268,7 @@ ipiput6(Fs *f, Ipifc *ifc, Block *bp)
/* don't forward to source's network */
rh.r = nil;
rh.a = nil;
r = v6lookup(f, h->dst, h->src, &rh);
if(r == nil || (nifc = r->ifc) == nil || (r->type & Rv4) != 0
|| (nifc == ifc && !ifc->reflect)){

2
sys/src/9/ip/loopbackmedium.c
View file

@ -71,7 +71,7 @@ loopbackunbind(Ipifc *ifc)
}
static void
loopbackbwrite(Ipifc *ifc, Block *bp, int, uchar*)
loopbackbwrite(Ipifc *ifc, Block *bp, int, uchar*, Routehint*)
{
LB *lb;

4
sys/src/9/ip/netdevmedium.c
View file

@ -9,7 +9,7 @@
static void netdevbind(Ipifc *ifc, int argc, char **argv);
static void netdevunbind(Ipifc *ifc);
static void netdevbwrite(Ipifc *ifc, Block *bp, int version, uchar *ip);
static void netdevbwrite(Ipifc *ifc, Block *bp, int version, uchar *ip, Routehint*);
static void netdevread(void *a);
typedef struct Netdevrock Netdevrock;
@ -99,7 +99,7 @@ netdevunbind(Ipifc *ifc)
* called by ipoput with a single block to write
*/
static void
netdevbwrite(Ipifc *ifc, Block *bp, int, uchar*)
netdevbwrite(Ipifc *ifc, Block *bp, int, uchar*, Routehint*)
{
Netdevrock *er = ifc->arg;

2
sys/src/9/ip/nullmedium.c
View file

@ -19,7 +19,7 @@ nullunbind(Ipifc*)
}
static void
nullbwrite(Ipifc*, Block *bp, int, uchar*)
nullbwrite(Ipifc*, Block *bp, int, uchar*, Routehint*)
{
freeb(bp);
error("nullbwrite");

4
sys/src/9/ip/pktmedium.c
View file

@ -10,7 +10,7 @@
static void pktbind(Ipifc*, int, char**);
static void pktunbind(Ipifc*);
static void pktbwrite(Ipifc*, Block*, int, uchar*);
static void pktbwrite(Ipifc*, Block*, int, uchar*, Routehint*);
static void pktin(Fs*, Ipifc*, Block*);
Medium pktmedium =
@ -49,7 +49,7 @@ pktunbind(Ipifc*)
* called by ipoput with a single packet to write
*/
static void
pktbwrite(Ipifc *ifc, Block *bp, int, uchar*)
pktbwrite(Ipifc *ifc, Block *bp, int, uchar*, Routehint*)
{
/* enqueue onto the conversation's rq */
if(ifc->conv->snoopers.ref > 0)