conterm/kern/devfs-posix.c

637 lines
9.5 KiB
C

#include "u.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#include <fcntl.h>
#include <errno.h>
#include <stdio.h> /* for remove, rename */
#include <limits.h>
#ifndef NAME_MAX
# define NAME_MAX 256
#endif
#include "lib.h"
#include "dat.h"
#include "fns.h"
#include "error.h"
typedef struct Ufsinfo Ufsinfo;
enum
{
NUID = 256,
NGID = 256,
MAXPATH = 1024,
MAXCOMP = 128
};
struct Ufsinfo
{
int mode;
int fd;
int uid;
int gid;
DIR* dir;
vlong offset;
QLock oq;
char nextname[NAME_MAX];
};
char *base = "/";
static Qid fsqid(char*, struct stat *);
static void fspath(Chan*, char*, char*);
static ulong fsdirread(Chan*, uchar*, int, ulong);
static int fsomode(int);
/* clumsy hack, but not worse than the Path stuff in the last one */
static char*
uc2name(Chan *c)
{
char *s;
if(c->name == nil)
return "/";
s = c2name(c);
if(s[0]=='#' && s[1]=='U')
return s+2;
return s;
}
static char*
lastelem(Chan *c)
{
char *s, *t;
s = uc2name(c);
if((t = strrchr(s, '/')) == nil)
return s;
if(t[1] == 0)
return t;
return t+1;
}
static Chan*
fsattach(char *spec)
{
Chan *c;
struct stat stbuf;
static int devno;
Ufsinfo *uif;
if(stat(base, &stbuf) < 0)
error(strerror(errno));
c = devattach('U', spec);
uif = mallocz(sizeof(Ufsinfo), 1);
uif->mode = stbuf.st_mode;
uif->uid = stbuf.st_uid;
uif->gid = stbuf.st_gid;
c->aux = uif;
c->dev = devno++;
c->qid.type = QTDIR;
/*print("fsattach %s\n", c2name(c));*/
return c;
}
static Chan*
fsclone(Chan *c, Chan *nc)
{
Ufsinfo *uif;
uif = mallocz(sizeof(Ufsinfo), 1);
*uif = *(Ufsinfo*)c->aux;
nc->aux = uif;
return nc;
}
static int
fswalk1(Chan *c, char *name)
{
struct stat stbuf;
char path[MAXPATH];
Ufsinfo *uif;
fspath(c, name, path);
/*print("** fs walk '%s' -> %s\n", path, name); */
if(stat(path, &stbuf) < 0)
return 0;
uif = c->aux;
uif->mode = stbuf.st_mode;
uif->uid = stbuf.st_uid;
uif->gid = stbuf.st_gid;
c->qid = fsqid(path, &stbuf);
return 1;
}
extern Cname* addelem(Cname*, char*);
static Walkqid*
fswalk(Chan *c, Chan *nc, char **name, int nname)
{
int i;
Cname *cname;
Walkqid *wq;
if(nc != nil)
panic("fswalk: nc != nil");
wq = smalloc(sizeof(Walkqid)+(nname-1)*sizeof(Qid));
nc = devclone(c);
cname = c->name;
incref(&cname->ref);
fsclone(c, nc);
wq->clone = nc;
for(i=0; i<nname; i++){
nc->name = cname;
if(fswalk1(nc, name[i]) == 0)
break;
cname = addelem(cname, name[i]);
wq->qid[i] = nc->qid;
}
nc->name = cname;
if(i != nname){
cclose(nc);
wq->clone = nil;
}
wq->nqid = i;
return wq;
}
static int
fsstat(Chan *c, uchar *buf, int n)
{
Dir d;
struct stat stbuf;
char path[MAXPATH];
if(n < BIT16SZ)
error(Eshortstat);
fspath(c, 0, path);
if(stat(path, &stbuf) < 0)
error(strerror(errno));
d.name = lastelem(c);
d.uid = "unknown";
d.gid = "unknown";
d.muid = "unknown";
d.qid = c->qid;
d.mode = (c->qid.type<<24)|(stbuf.st_mode&0777);
d.atime = stbuf.st_atime;
d.mtime = stbuf.st_mtime;
d.length = stbuf.st_size;
d.type = 'U';
d.dev = c->dev;
return convD2M(&d, buf, n);
}
static Chan*
fsopen(Chan *c, int mode)
{
char path[MAXPATH];
int m, isdir;
Ufsinfo *uif;
/*print("fsopen %s\n", c2name(c));*/
m = mode & (OTRUNC|3);
switch(m) {
case 0:
break;
case 1:
case 1|16:
break;
case 2:
case 0|16:
case 2|16:
break;
case 3:
break;
default:
error(Ebadarg);
}
isdir = c->qid.type & QTDIR;
if(isdir && mode != OREAD)
error(Eperm);
m = fsomode(m & 3);
c->mode = openmode(mode);
uif = c->aux;
fspath(c, 0, path);
if(isdir) {
uif->dir = opendir(path);
if(uif->dir == 0)
error(strerror(errno));
}
else {
if(mode & OTRUNC)
m |= O_TRUNC;
uif->fd = open(path, m, 0666);
if(uif->fd < 0)
error(strerror(errno));
}
uif->offset = 0;
c->offset = 0;
c->flag |= COPEN;
return c;
}
static void
fscreate(Chan *c, char *name, int mode, ulong perm)
{
int fd, m;
char path[MAXPATH];
struct stat stbuf;
Ufsinfo *uif;
m = fsomode(mode&3);
fspath(c, name, path);
uif = c->aux;
if(perm & DMDIR) {
if(m)
error(Eperm);
if(mkdir(path, perm & 0777) < 0)
error(strerror(errno));
fd = open(path, 0);
if(fd >= 0) {
chmod(path, perm & 0777);
chown(path, uif->uid, uif->uid);
}
close(fd);
uif->dir = opendir(path);
if(uif->dir == 0)
error(strerror(errno));
}
else {
fd = open(path, O_WRONLY|O_CREAT|O_TRUNC, 0666);
if(fd >= 0) {
if(m != 1) {
close(fd);
fd = open(path, m);
}
chmod(path, perm & 0777);
chown(path, uif->uid, uif->gid);
}
if(fd < 0)
error(strerror(errno));
uif->fd = fd;
}
if(stat(path, &stbuf) < 0)
error(strerror(errno));
c->qid = fsqid(path, &stbuf);
c->offset = 0;
c->flag |= COPEN;
c->mode = openmode(mode);
}
static void
fsclose(Chan *c)
{
Ufsinfo *uif;
uif = c->aux;
if(c->flag & COPEN) {
if(c->qid.type & QTDIR)
closedir(uif->dir);
else
close(uif->fd);
}
free(uif);
}
static long
fsread(Chan *c, void *va, long n, vlong offset)
{
int fd, r;
Ufsinfo *uif;
/*print("fsread %s\n", c2name(c));*/
if(c->qid.type & QTDIR)
return fsdirread(c, va, n, offset);
uif = c->aux;
qlock(&uif->oq);
if(waserror()) {
qunlock(&uif->oq);
nexterror();
}
fd = uif->fd;
if(uif->offset != offset) {
r = lseek(fd, offset, 0);
if(r < 0)
error(strerror(errno));
uif->offset = offset;
}
n = read(fd, va, n);
if(n < 0)
error(strerror(errno));
uif->offset += n;
qunlock(&uif->oq);
poperror();
return n;
}
static long
fswrite(Chan *c, void *va, long n, vlong offset)
{
int fd, r;
Ufsinfo *uif;
uif = c->aux;
qlock(&uif->oq);
if(waserror()) {
qunlock(&uif->oq);
nexterror();
}
fd = uif->fd;
if(uif->offset != offset) {
r = lseek(fd, offset, 0);
if(r < 0)
error(strerror(errno));
uif->offset = offset;
}
n = write(fd, va, n);
if(n < 0)
error(strerror(errno));
uif->offset += n;
qunlock(&uif->oq);
poperror();
return n;
}
static void
fsremove(Chan *c)
{
int n;
char path[MAXPATH];
fspath(c, 0, path);
if(c->qid.type & QTDIR)
n = rmdir(path);
else
n = remove(path);
if(n < 0)
error(strerror(errno));
}
int
fswstat(Chan *c, uchar *buf, int n)
{
Dir d;
struct stat stbuf;
char old[MAXPATH], new[MAXPATH];
char strs[MAXPATH*3], *p;
Ufsinfo *uif;
if(convM2D(buf, n, &d, strs) != n)
error(Ebadstat);
fspath(c, 0, old);
if(stat(old, &stbuf) < 0)
error(strerror(errno));
uif = c->aux;
fspath(c, 0, old);
if(~d.mode != 0 && (int)(d.mode&0777) != (int)(stbuf.st_mode&0777)) {
if(chmod(old, d.mode&0777) < 0)
error(strerror(errno));
uif->mode &= ~0777;
uif->mode |= d.mode&0777;
}
if(d.name[0] && strcmp(d.name, lastelem(c)) != 0) {
fspath(c, 0, old);
strcpy(new, old);
p = strrchr(new, '/');
strcpy(p+1, d.name);
if(rename(old, new) < 0)
error(strerror(errno));
}
/*
p = name2pass(gid, d.gid);
if(p == 0)
error(Eunknown);
if(p->id != stbuf.st_gid) {
if(chown(old, stbuf.st_uid, p->id) < 0)
error(strerror(errno));
uif->gid = p->id;
}
*/
return n;
}
static Qid
fsqid(char *p, struct stat *st)
{
Qid q;
int dev;
ulong h;
static int nqdev;
static uchar *qdev;
if(qdev == 0)
qdev = mallocz(65536U, 1);
q.type = 0;
if((st->st_mode&S_IFMT) == S_IFDIR)
q.type = QTDIR;
dev = st->st_dev & 0xFFFFUL;
if(qdev[dev] == 0)
qdev[dev] = ++nqdev;
h = 0;
while(*p != '\0')
h += *p++ * 13;
q.path = (vlong)qdev[dev]<<32;
q.path |= h;
q.vers = st->st_mtime;
return q;
}
static void
fspath(Chan *c, char *ext, char *path)
{
strcpy(path, base);
strcat(path, "/");
strcat(path, uc2name(c));
if(ext){
strcat(path, "/");
strcat(path, ext);
}
cleanname(path);
}
static int
isdots(char *name)
{
if(name[0] != '.')
return 0;
if(name[1] == '\0')
return 1;
if(name[1] != '.')
return 0;
if(name[2] == '\0')
return 1;
return 0;
}
static int
p9readdir(char *name, Ufsinfo *uif)
{
struct dirent *de;
if(uif->nextname[0]){
strcpy(name, uif->nextname);
uif->nextname[0] = 0;
return 1;
}
de = readdir(uif->dir);
if(de == NULL)
return 0;
strcpy(name, de->d_name);
return 1;
}
static ulong
fsdirread(Chan *c, uchar *va, int count, ulong offset)
{
int i;
Dir d;
long n;
char de[NAME_MAX];
struct stat stbuf;
char path[MAXPATH], dirpath[MAXPATH];
Ufsinfo *uif;
/*print("fsdirread %s\n", c2name(c));*/
i = 0;
uif = c->aux;
errno = 0;
if(uif->offset != offset) {
if(offset != 0)
error("bad offset in fsdirread");
uif->offset = offset; /* sync offset */
uif->nextname[0] = 0;
rewinddir(uif->dir);
}
fspath(c, 0, dirpath);
while(i+BIT16SZ < count) {
if(!p9readdir(de, uif))
break;
if(de[0]==0 || isdots(de))
continue;
d.name = de;
sprint(path, "%s/%s", dirpath, de);
memset(&stbuf, 0, sizeof stbuf);
if(stat(path, &stbuf) < 0) {
/* fprint(2, "dir: bad path %s\n", path); */
/* but continue... probably a bad symlink */
}
d.uid = "unknown";
d.gid = "unknown";
d.muid = "unknown";
d.qid = fsqid(path, &stbuf);
d.mode = (d.qid.type<<24)|(stbuf.st_mode&0777);
d.atime = stbuf.st_atime;
d.mtime = stbuf.st_mtime;
d.length = stbuf.st_size;
d.type = 'U';
d.dev = c->dev;
n = convD2M(&d, (uchar*)va+i, count-i);
if(n == BIT16SZ){
strcpy(uif->nextname, de);
break;
}
i += n;
}
/*print("got %d\n", i);*/
uif->offset += i;
return i;
}
static int
fsomode(int m)
{
switch(m) {
case 0: /* OREAD */
case 3: /* OEXEC */
return 0;
case 1: /* OWRITE */
return 1;
case 2: /* ORDWR */
return 2;
}
error(Ebadarg);
return 0;
}
Dev fsdevtab = {
'U',
"fs",
devreset,
devinit,
devshutdown,
fsattach,
fswalk,
fsstat,
fsopen,
fscreate,
fsclose,
fsread,
devbread,
fswrite,
devbwrite,
fsremove,
fswstat,
};