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#include "u.h"
#include "../port/lib.h"
#include "mem.h"
#include "dat.h"
#include "fns.h"
#include "../port/error.h"
#include "ip.h"
enum
{
Maxtu= 16*1024,
};
typedef struct LB LB;
struct LB
{
Proc *readp;
Queue *q;
Fs *f;
};
static void loopbackread(void *a);
static void
loopbackbind(Ipifc *ifc, int, char**)
{
LB *lb;
lb = smalloc(sizeof(*lb));
lb->readp = (void*)-1;
lb->f = ifc->conv->p->f;
lb->q = qopen(1024*1024, Qmsg, nil, nil);
ifc->arg = lb;
kproc("loopbackread", loopbackread, ifc);
}
static void
loopbackunbind(Ipifc *ifc)
{
LB *lb = ifc->arg;
while(waserror())
;
/* wat for reader to start */
while(lb->readp == (void*)-1)
tsleep(&up->sleep, return0, 0, 300);
if(lb->readp != nil)
postnote(lb->readp, 1, "unbind", 0);
poperror();
wunlock(ifc);
while(waserror())
;
/* wait for reader to die */
while(lb->readp != nil)
tsleep(&up->sleep, return0, 0, 300);
poperror();
wlock(ifc);
/* clean up */
qfree(lb->q);
free(lb);
}
static void
loopbackbwrite(Ipifc *ifc, Block *bp, int, uchar*)
{
LB *lb;
lb = ifc->arg;
if(qpass(lb->q, bp) < 0)
ifc->outerr++;
ifc->out++;
}
static void
loopbackread(void *a)
{
Ipifc *ifc;
Block *bp;
LB *lb;
ifc = a;
lb = ifc->arg;
lb->readp = up; /* hide identity under a rock for unbind */
if(!waserror())
while((bp = qbread(lb->q, Maxtu)) != nil){
rlock(ifc);
if(waserror()){
runlock(ifc);
nexterror();
}
ifc->in++;
if(ifc->lifc == nil)
freeb(bp);
else
ipiput4(lb->f, ifc, bp);
runlock(ifc);
poperror();
}
lb->readp = nil;
pexit("hangup", 1);
}
Medium loopbackmedium =
{
.hsize= 0,
.mintu= 0,
.maxtu= Maxtu,
.maclen= 0,
.name= "loopback",
.bind= loopbackbind,
.unbind= loopbackunbind,
.bwrite= loopbackbwrite,
};
void
loopbackmediumlink(void)
{
addipmedium(&loopbackmedium);
}
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