172 lines
2.9 KiB
C
172 lines
2.9 KiB
C
#include "u.h"
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#include "../port/lib.h"
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#include "mem.h"
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#include "dat.h"
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#include "fns.h"
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#include "../port/error.h"
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#define INT_MAX ((1<<31)-1)
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extern int sysdup(int ofd, int nfd);
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/* Qid is (2*fd + (file is ctl))+1 */
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static int
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dupgen(Chan *c, char * _1, Dirtab* _2, int _3, int s, Dir *dp)
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{
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Fgrp *fgrp = up->fgrp;
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Chan *f;
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static int perm[] = { 0, 0400, 0200, 0600, 0 };
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int p;
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Qid q;
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if(s == DEVDOTDOT){
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devdir(c, c->qid, ".", 0, eve, DMDIR|0555, dp);
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return 1;
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}
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if(s == 0)
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return 0;
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s--;
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if(s/2 > fgrp->maxfd)
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return -1;
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if((f=fgrp->fd[s/2]) == nil)
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return 0;
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if(s & 1){
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p = 0400;
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jehanne_sprint(up->genbuf, "%dctl", s/2);
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}else{
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p = perm[f->mode&7];
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jehanne_sprint(up->genbuf, "%d", s/2);
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}
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mkqid(&q, s+1, 0, QTFILE);
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devdir(c, q, up->genbuf, 0, eve, p, dp);
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return 1;
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}
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static Chan*
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dupattach(Chan *c, Chan *ac, char *spec, int flags)
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{
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return devattach('d', spec);
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}
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static Walkqid*
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dupwalk(Chan *c, Chan *nc, char **name, int nname)
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{
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return devwalk(c, nc, name, nname, (Dirtab *)0, 0, dupgen);
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}
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static long
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dupstat(Chan *c, uint8_t *db, long n)
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{
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return devstat(c, db, n, (Dirtab *)0, 0L, dupgen);
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}
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static Chan*
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dupcreate(Chan* c, char* name, unsigned long omode, unsigned long perm)
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{
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FdPair in, out;
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if((omode|OCEXEC) == ~0 && c->qid.path == 0){
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in.aslong = perm;
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/* ensure that fd.aslong never get ~0 value */
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if(in.fd[1] == 0){
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/* the requested fd is zero: out.fd[0] will
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* prevent the whole fd.aslong to become -1
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* if the operation succeed
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*/
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out.fd[0] = -1;
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} else {
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out.fd[0] = 0;
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}
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out.fd[1] = sysdup(in.fd[0], in.fd[1]);
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errorl(nil, ~out.aslong);
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}
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error(Eperm);
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}
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static Chan*
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dupopen(Chan *c, unsigned long omode)
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{
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Chan *f;
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int fd, twicefd;
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if(c->qid.type & QTDIR){
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if(omode != OREAD)
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error(Eisdir);
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c->mode = OREAD;
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c->flag |= COPEN;
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c->offset = 0;
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return c;
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}
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if(c->qid.type & QTAUTH)
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error(Eperm);
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twicefd = c->qid.path - 1;
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fd = twicefd/2;
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if((twicefd & 1)){
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/* ctl file */
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f = c;
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f->mode = openmode(omode);
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f->flag |= COPEN;
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f->offset = 0;
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}else{
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/* fd file */
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f = fdtochan(fd, openmode(omode), 0, 1);
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cclose(c);
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}
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if(omode & OCEXEC)
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f->flag |= CCEXEC;
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return f;
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}
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static void
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dupclose(Chan* _1)
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{
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}
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static long
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dupread(Chan *c, void *va, long n, int64_t off)
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{
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char buf[256];
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int fd, twicefd;
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if(c->qid.type & QTDIR)
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return devdirread(c, va, n, (Dirtab *)0, 0L, dupgen);
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twicefd = c->qid.path - 1;
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fd = twicefd/2;
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if(twicefd & 1){
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c = fdtochan(fd, -1, 0, 1);
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procfdprint(c, fd, 0, buf, sizeof buf);
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cclose(c);
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return readstr(off, va, n, buf);
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}
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panic("dupread");
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return 0;
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}
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static long
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dupwrite(Chan* _1, void* _2, long _3, int64_t _4)
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{
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error(Eperm);
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return 0; /* not reached */
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}
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Dev dupdevtab = {
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'd',
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"dup",
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devreset,
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devinit,
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devshutdown,
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dupattach,
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dupwalk,
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dupstat,
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dupopen,
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dupcreate,
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dupclose,
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dupread,
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devbread,
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dupwrite,
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devbwrite,
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devremove,
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devwstat,
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};
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