2001/0822/port/dev.c (diff list | history)

port/dev.c on 1990/0227
1990/0227		#include "u.h"
1992/0321		#include "../port/lib.h"
1990/0227		#include "mem.h" #include "dat.h" #include "fns.h"
1992/0111		#include "../port/error.h"
1990/0227
1991/1220		extern ulong kerndate;
2001/0527		void mkqid(Qid *q, vlong path, ulong vers, int type) { q->type = type; q->vers = vers; q->path = path; }
1990/0227		int devno(int c, int user) {
1992/1217		int i;
1990/0227
1997/0408		for(i = 0; devtab[i] != nil; i++) { if(devtab[i]->dc == c)
1992/1217		return i;
1990/0227		}
1997/0408		if(user == 0) panic("devno %C 0x%ux", c, c);
1992/1217
1997/0408		return -1;
1990/0227		} void
1998/0326		devdir(Chan *c, Qid qid, char *n, vlong length, char *user, long perm, Dir *db)
1990/0227		{
2001/0527		db->name = n;
1990/0227		db->qid = qid;
1997/0408		db->type = devtab[c->type]->dc;
1990/0227		db->dev = c->dev;
2001/0527		db->mode = perm; db->mode |= qid.type << 24;
1990/0227		db->atime = seconds();
1991/1220		db->mtime = kerndate;
1998/0326		db->length = length;
2001/0527		db->uid = user; db->gid = eve; db->muid = user;
1990/0227		}
2001/0527		/* * the zeroth element of the table MUST be the directory itself for .. */
1990/0227		int
2001/0527		devgen(Chan *c, char*, Dirtab *tab, int ntab, int i, Dir *dp)
1990/0227		{
2001/0527		if(tab == 0)
1990/0227		return -1;
2001/0527		if(i != DEVDOTDOT){ /* skip over the first element, that for . itself */ i++; if(i >= ntab)
1999/1230		return -1; tab += i; }
1991/1109		devdir(c, tab->qid, tab->name, tab->length, eve, tab->perm, dp);
1990/0227		return 1; }
1997/0327		void devreset(void) { } void devinit(void) { } Chan*
1990/0227		devattach(int tc, char *spec) { Chan *c;
2001/0527		char *buf;
1990/0227		c = newchan();
2001/0527		mkqid(&c->qid, 0, 0, QTDIR);
1990/0227		c->type = devno(tc, 0);
2001/0527		if(spec == nil) spec = ""; buf = smalloc(4+strlen(spec)+1); sprint(buf, "#%C%s", tc, spec);
1999/0629		c->name = newcname(buf);
2001/0527		free(buf);
1990/0227		return c; }
2001/0527
1997/0327		Chan*
2001/0527		devclone(Chan *c)
1990/0227		{
2001/0527		Chan *nc;
1990/0329		if(c->flag & COPEN)
1997/0408		panic("clone of open file type %C\n", devtab[c->type]->dc);
1993/0501
2001/0527		nc = newchan();
1993/0501
1990/0227		nc->type = c->type;
1991/0421		nc->dev = c->dev;
1990/0227		nc->mode = c->mode; nc->qid = c->qid; nc->offset = c->offset;
2001/0527		nc->umh = nil;
1991/0427		nc->mountid = c->mountid;
1991/0421		nc->aux = c->aux;
1990/0303		nc->mqid = c->mqid;
1993/1013		nc->mcp = c->mcp;
1990/0227		return nc; }
2001/0527		Walkqid* devwalk(Chan *c, Chan *nc, char **name, int nname, Dirtab *tab, int ntab, Devgen *gen)
1990/0227		{
2001/0527		int i, j, alloc; Walkqid *wq; char *n;
1990/0227		Dir dir;
2001/0527		if(nname > 0) isdir(c); alloc = 0; wq = smalloc(sizeof(Walkqid)+(nname-1)*sizeof(Qid)); if(waserror()){ if(alloc && wq->clone!=nil) cclose(wq->clone); free(wq); return nil; } if(nc == nil){ nc = devclone(c); nc->type = 0; /* device doesn't know about this channel yet */ alloc = 1;
1999/1230		}
2001/0527		wq->clone = nc; for(j=0; j<nname; j++){ isdir(nc); n = name[j]; if(strcmp(n, ".") == 0){ Accept: wq->qid[wq->nqid++] = nc->qid;
1990/0227		continue;
2001/0527		} if(strcmp(n, "..") == 0){ (*gen)(nc, nil, tab, ntab, DEVDOTDOT, &dir); nc->qid = dir.qid; goto Accept; } /* * Ugly problem: If we're using devgen, make sure we're * walking the directory itself, represented by the first * entry in the table, and not trying to step into a sub- * directory of the table, e.g. /net/net. Devgen itself * should take care of the problem, but it doesn't have * the necessary information (that we're doing a walk). */ if(gen==devgen && nc->qid.path!=tab[0].qid.path) goto Notfound; for(i=0;; i++) { switch((*gen)(nc, n, tab, ntab, i, &dir)){ case -1: Notfound: if(j == 0) error(Enonexist); strncpy(up->error, Enonexist, ERRMAX); goto Done; case 0: continue; case 1: if(strcmp(n, dir.name) == 0){ nc->qid = dir.qid; goto Accept; } continue;
1990/0227		} }
1993/0501		}
2001/0527		/* * We processed at least one name, so will return some data. * If we didn't process all nname entries succesfully, we drop * the cloned channel and return just the Qids of the walks. */ Done: poperror(); if(wq->nqid < nname){ if(alloc) cclose(wq->clone); wq->clone = nil; }else if(wq->clone){ /* attach cloned channel to same device */ wq->clone->type = c->type; } return wq;
1991/0411		}
2001/0527		int devstat(Chan *c, uchar *db, int n, Dirtab *tab, int ntab, Devgen *gen)
1990/0227		{ int i; Dir dir;
1999/0629		char *p, *elem;
1990/0227
1993/0330		for(i=0;; i++)
2001/0527		switch((*gen)(c, nil, tab, ntab, i, &dir)){
1990/0227		case -1:
2001/0527		if(c->qid.type & QTDIR){
1999/0629		if(c->name == nil) elem = "???";
1999/0710		else if(strcmp(c->name->s, "/") == 0) elem = "/";
1999/0629		else for(elem=p=c->name->s; *p; p++)
1999/0724		if(*p == '/')
1999/0629		elem = p+1;
2001/0527		devdir(c, c->qid, elem, 0, eve, DMDIR|0555, &dir); n = convD2M(&dir, db, n); if(n == 0) error(Ebadarg); return n;
1990/0227		}
2001/0527		print("%s %s: devstat %C %llux\n",
1997/0327		up->text, up->user,
1997/0408		devtab[c->type]->dc, c->qid.path);
1997/0327
1991/0626		error(Enonexist);
1993/0330		case 0: break;
1990/0227		case 1:
1999/0122		if(c->qid.path == dir.qid.path) {
1993/0323		if(c->flag&CMSG)
2001/0527		dir.mode |= DMMOUNT; n = convD2M(&dir, db, n); if(n == 0) error(Ebadarg); return n;
1990/0227		} break; }
2001/0527		error(Egreg); /* not reached? */ return -1;
1990/0227		} long devdirread(Chan *c, char *d, long n, Dirtab *tab, int ntab, Devgen *gen) {
2001/0822		long m, dsz;
2001/0527		struct{ Dir; char slop[100]; }dir;
1990/0227
2001/0822		for(m=0; m<n; c->dri++) { switch((*gen)(c, nil, tab, ntab, c->dri, &dir)){
1990/0227		case -1:
1990/0821		return m;
1990/0227		case 0: break; case 1:
2001/0527		dsz = convD2M(&dir, (uchar*)d, n-m); if(dsz <= BIT16SZ){ /* <= not < because this isn't stat; read is stuck */ if(m == 0) return -1; return m; } m += dsz; d += dsz;
1990/0227		break; }
1993/0501		}
1990/0821		return m;
1990/0227		}
2000/0718		/* * error(Eperm) if open permission not granted for up->user. */ void devpermcheck(char *fileuid, ulong perm, int omode) { ulong t; static int access[] = { 0400, 0200, 0600, 0100 }; if(strcmp(up->user, fileuid) == 0) perm <<= 0; else if(strcmp(up->user, eve) == 0) perm <<= 3; else perm <<= 6; t = access[omode&3]; if((t&perm) != t) error(Eperm); }
1997/0327		Chan*
1990/0227		devopen(Chan *c, int omode, Dirtab *tab, int ntab, Devgen *gen) { int i; Dir dir;
1993/0501		for(i=0;; i++) {
2001/0527		switch((*gen)(c, nil, tab, ntab, i, &dir)){
1990/0227		case -1: goto Return; case 0: break; case 1:
1999/0122		if(c->qid.path == dir.qid.path) {
2000/0718		devpermcheck(dir.uid, dir.mode, omode); goto Return;
1990/0227		} break; }
1993/0501		} Return:
1990/0227		c->offset = 0;
2001/0527		if((c->qid.type&QTDIR) && omode!=OREAD)
1990/11211		error(Eperm);
1990/0227		c->mode = openmode(omode); c->flag |= COPEN; return c; }
1995/0108
1998/0512		void
1997/0327		devcreate(Chan*, char*, int, ulong) { error(Eperm); }
1995/0108		Block* devbread(Chan *c, long n, ulong offset) { Block *bp; bp = allocb(n); if(bp == 0) error(Enomem); if(waserror()) { freeb(bp); nexterror(); }
1997/0327		bp->wp += devtab[c->type]->read(c, bp->wp, n, offset);
1995/0108		poperror(); return bp; } long devbwrite(Chan *c, Block *bp, ulong offset) { long n;
2000/0817		if(waserror()) { freeb(bp); nexterror(); }
1997/0327		n = devtab[c->type]->write(c, bp->rp, BLEN(bp), offset);
2000/0817		poperror();
1995/0108		freeb(bp);
1998/0512		return n;
1995/0108		}
1997/0327		void devremove(Chan*) { error(Eperm); }
2001/0527		int devwstat(Chan*, uchar*, int)
1997/0327		{ error(Eperm);
2001/0527		return 0;
1997/0327		}