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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"
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 netdevread(void *a);
typedef struct Netdevrock Netdevrock;
struct Netdevrock
{
Fs *f; /* file system we belong to */
Proc *readp; /* reading process */
Chan *mchan; /* Data channel */
};
Medium netdevmedium =
{
.name= "netdev",
.hsize= 0,
.mintu= 0,
.maxtu= 64000,
.maclen= 0,
.bind= netdevbind,
.unbind= netdevunbind,
.bwrite= netdevbwrite,
.unbindonclose= 0,
};
/*
* called to bind an IP ifc to a generic network device
* called with ifc qlock'd
*/
static void
netdevbind(Ipifc *ifc, int argc, char **argv)
{
Chan *mchan;
Netdevrock *er;
if(argc < 2)
error(Ebadarg);
mchan = namec(argv[2], Aopen, ORDWR, 0);
er = smalloc(sizeof(*er));
er->mchan = mchan;
er->f = ifc->conv->p->f;
ifc->arg = er;
kproc("netdevread", netdevread, ifc);
}
/*
* called with ifc wlock'd
*/
static void
netdevunbind(Ipifc *ifc)
{
Netdevrock *er = ifc->arg;
if(er->readp != nil)
postnote(er->readp, 1, "unbind", 0);
/* wait for readers to die */
while(er->readp != nil)
tsleep(&up->sleep, return0, 0, 300);
if(er->mchan != nil)
cclose(er->mchan);
free(er);
}
/*
* called by ipoput with a single block to write
*/
static void
netdevbwrite(Ipifc *ifc, Block *bp, int, uchar*)
{
Netdevrock *er = ifc->arg;
if(BLEN(bp) < ifc->mintu)
bp = adjustblock(bp, ifc->mintu);
devtab[er->mchan->type]->bwrite(er->mchan, bp, 0);
ifc->out++;
}
/*
* process to read from the device
*/
static void
netdevread(void *a)
{
Ipifc *ifc;
Block *bp;
Netdevrock *er;
char *argv[1];
ifc = a;
er = ifc->arg;
er->readp = up; /* hide identity under a rock for unbind */
if(waserror()){
er->readp = nil;
pexit("hangup", 1);
}
for(;;){
bp = devtab[er->mchan->type]->bread(er->mchan, ifc->maxtu, 0);
if(bp == nil){
/*
* get here if mchan is a pipe and other side hangs up
* clean up this interface & get out
ZZZ is this a good idea?
*/
poperror();
er->readp = nil;
argv[0] = "unbind";
if(!waserror())
ifc->conv->p->ctl(ifc->conv, argv, 1);
pexit("hangup", 1);
}
if(!canrlock(ifc)){
freeb(bp);
continue;
}
if(waserror()){
runlock(ifc);
nexterror();
}
ifc->in++;
if(ifc->lifc == nil)
freeb(bp);
else
ipiput4(er->f, ifc, bp);
runlock(ifc);
poperror();
}
}
void
netdevmediumlink(void)
{
addipmedium(&netdevmedium);
}
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