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#include "u.h"
#include "../port/lib.h"
#include "mem.h"
#include "dat.h"
#include "fns.h"
#include "../port/error.h"
/* Qid is (2*fd + (file is ctl))+1 */
static int
dupgen(Chan *c, char *, Dirtab*, int, int s, Dir *dp)
{
Fgrp *fgrp = up->fgrp;
Chan *f;
static int perm[] = { 0400, 0200, 0600, 0 };
int p;
Qid q;
if(s == DEVDOTDOT){
devdir(c, c->qid, ".", 0, eve, 0555, dp);
return 1;
}
if(s == 0)
return 0;
s--;
if(s/2 > fgrp->maxfd)
return -1;
if((f=fgrp->fd[s/2]) == nil)
return 0;
if(s & 1){
p = 0400;
sprint(up->genbuf, "%dctl", s/2);
}else{
p = perm[f->mode&3];
sprint(up->genbuf, "%d", s/2);
}
mkqid(&q, s+1, 0, QTFILE);
devdir(c, q, up->genbuf, 0, eve, p, dp);
return 1;
}
static Chan*
dupattach(char *spec)
{
return devattach('d', spec);
}
static Walkqid*
dupwalk(Chan *c, Chan *nc, char **name, int nname)
{
return devwalk(c, nc, name, nname, (Dirtab *)0, 0, dupgen);
}
static int
dupstat(Chan *c, uchar *db, int n)
{
return devstat(c, db, n, (Dirtab *)0, 0L, dupgen);
}
static Chan*
dupopen(Chan *c, int omode)
{
Chan *f;
int fd, twicefd;
if(omode & ORCLOSE)
error(Eperm);
if(c->qid.type & QTDIR){
if(omode != 0)
error(Eisdir);
c->mode = 0;
c->flag |= COPEN;
c->offset = 0;
return c;
}
if(c->qid.type & QTAUTH)
error(Eperm);
twicefd = c->qid.path - 1;
fd = twicefd/2;
if((twicefd & 1)){
/* ctl file */
f = c;
f->mode = openmode(omode);
f->flag |= COPEN;
f->offset = 0;
}else{
/* fd file */
f = fdtochan(fd, openmode(omode), 0, 1);
cclose(c);
}
return f;
}
static void
dupclose(Chan*)
{
}
static long
dupread(Chan *c, void *va, long n, vlong offset)
{
char *a = va;
char buf[256];
int fd, twicefd;
if(c->qid.type == QTDIR)
return devdirread(c, a, n, (Dirtab *)0, 0L, dupgen);
twicefd = c->qid.path - 1;
fd = twicefd/2;
if(twicefd & 1){
c = fdtochan(fd, -1, 0, 1);
procfdprint(c, fd, buf, sizeof buf);
cclose(c);
return readstr((ulong)offset, va, n, buf);
}
panic("dupread");
return 0;
}
static long
dupwrite(Chan*, void*, long, vlong)
{
error(Eperm);
return 0; /* not reached */
}
Dev dupdevtab = {
'd',
"dup",
devreset,
devinit,
devshutdown,
dupattach,
dupwalk,
dupstat,
dupopen,
devcreate,
dupclose,
dupread,
devbread,
dupwrite,
devbwrite,
devremove,
devwstat,
};
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