1678 lines
33 KiB
C
1678 lines
33 KiB
C
/* Copyright (C) Charles Forsyth
|
|
* See /doc/license/NOTICE.Plan9-9k.txt for details about the licensing.
|
|
*/
|
|
/* Portions of this file are Copyright (C) 2015-2018 Giacomo Tesio <giacomo@tesio.it>
|
|
* See /doc/license/gpl-2.0.txt for details about the licensing.
|
|
*/
|
|
/* Portions of this file are Copyright (C) 9front's team.
|
|
* See /doc/license/9front-mit for details about the licensing.
|
|
* See http://git.9front.org/plan9front/plan9front/HEAD/info.html for a list of authors.
|
|
*/
|
|
#include "u.h"
|
|
#include "../port/lib.h"
|
|
#include "mem.h"
|
|
#include "dat.h"
|
|
#include "fns.h"
|
|
#include "../port/error.h"
|
|
|
|
enum
|
|
{
|
|
PATHSLOP = 20,
|
|
PATHMSLOP = 20,
|
|
};
|
|
|
|
struct
|
|
{
|
|
Lock;
|
|
int fid;
|
|
Chan *free;
|
|
Chan *list;
|
|
}chanalloc;
|
|
|
|
typedef struct Elemlist Elemlist;
|
|
|
|
struct Elemlist
|
|
{
|
|
char *aname; /* original name */
|
|
char *name; /* copy of name, so '/' can be overwritten */
|
|
int nelems;
|
|
char **elems;
|
|
int *off;
|
|
int mustbedir;
|
|
int nerror;
|
|
int prefix;
|
|
};
|
|
|
|
char*
|
|
chanpath(Chan *c)
|
|
{
|
|
if(c == nil)
|
|
return "<nil chan>";
|
|
if(c->path == nil)
|
|
return "<nil path>";
|
|
if(c->path->s == nil)
|
|
return "<nil path.s>";
|
|
return c->path->s;
|
|
}
|
|
|
|
int
|
|
isdotdot(char *p)
|
|
{
|
|
return p[0]=='.' && p[1]=='.' && p[2]=='\0';
|
|
}
|
|
|
|
/*
|
|
* Rather than strncpy, which zeros the rest of the buffer, kstrcpy
|
|
* truncates if necessary, always zero terminates, does not zero fill,
|
|
* and puts ... at the end of the string if it's too long. Usually used to
|
|
* save a string in up->genbuf;
|
|
*/
|
|
void
|
|
kstrcpy(char *s, char *t, int ns)
|
|
{
|
|
int nt;
|
|
|
|
nt = jehanne_strlen(t);
|
|
if(nt+1 <= ns){
|
|
jehanne_memmove(s, t, nt+1);
|
|
return;
|
|
}
|
|
/* too long */
|
|
if(ns < 4){
|
|
/* but very short! */
|
|
jehanne_strncpy(s, t, ns);
|
|
return;
|
|
}
|
|
/* truncate with ... at character boundary (very rare case) */
|
|
jehanne_memmove(s, t, ns-4);
|
|
ns -= 4;
|
|
s[ns] = '\0';
|
|
/* look for first byte of UTF-8 sequence by skipping continuation bytes */
|
|
while(ns>0 && (s[--ns]&0xC0)==0x80)
|
|
;
|
|
jehanne_strcpy(s+ns, "...");
|
|
}
|
|
|
|
int
|
|
emptystr(char *s)
|
|
{
|
|
if(s == nil)
|
|
return 1;
|
|
if(s[0] == '\0')
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Atomically replace *p with copy of s
|
|
*/
|
|
void
|
|
kstrdup(char **p, char *s)
|
|
{
|
|
int n;
|
|
char *t, *prev;
|
|
|
|
n = jehanne_strlen(s);
|
|
/* if it's a user, we can wait for memory; if not, something's very wrong */
|
|
if(up){
|
|
t = smalloc(n+1);
|
|
}else{
|
|
t = jehanne_malloc(n+1);
|
|
if(t == nil)
|
|
panic("kstrdup: no memory");
|
|
}
|
|
jehanne_setmalloctag(t, getcallerpc());
|
|
jehanne_memmove(t, s, n);
|
|
t[n] = '\0';
|
|
prev = *p;
|
|
*p = t;
|
|
jehanne_free(prev);
|
|
}
|
|
|
|
Chan*
|
|
newchan(void)
|
|
{
|
|
Chan *c;
|
|
|
|
lock(&chanalloc);
|
|
c = chanalloc.free;
|
|
if(c != 0)
|
|
chanalloc.free = c->next;
|
|
unlock(&chanalloc);
|
|
|
|
if(c == nil){
|
|
c = smalloc(sizeof(Chan));
|
|
lock(&chanalloc);
|
|
c->fid = ++chanalloc.fid;
|
|
c->link = chanalloc.list;
|
|
chanalloc.list = c;
|
|
unlock(&chanalloc);
|
|
}
|
|
|
|
c->dev = nil;
|
|
c->flag = 0;
|
|
c->r.ref = 1;
|
|
c->devno = 0;
|
|
c->offset = 0;
|
|
c->devoffset = 0;
|
|
c->iounit = 0;
|
|
c->umh = 0;
|
|
c->uri = 0;
|
|
c->dri = 0;
|
|
c->aux = 0;
|
|
c->mchan = 0;
|
|
c->mux = 0;
|
|
jehanne_memset(&c->mqid, 0, sizeof(c->mqid));
|
|
c->path = 0;
|
|
c->ismtpt = 0;
|
|
|
|
return c;
|
|
}
|
|
|
|
Ref npath;
|
|
|
|
Path*
|
|
newpath(char *s)
|
|
{
|
|
int i;
|
|
Path *p;
|
|
|
|
p = smalloc(sizeof(Path));
|
|
i = jehanne_strlen(s);
|
|
p->len = i;
|
|
p->alen = i+PATHSLOP;
|
|
p->s = smalloc(p->alen);
|
|
jehanne_memmove(p->s, s, i+1);
|
|
p->r.ref = 1;
|
|
incref(&npath);
|
|
|
|
/*
|
|
* Cannot use newpath for arbitrary names because the mtpt
|
|
* array will not be populated correctly. The names #/ and / are
|
|
* allowed, but other names with / in them draw warnings.
|
|
*/
|
|
if(jehanne_strchr(s, '/') && jehanne_strcmp(s, "#/") != 0 && jehanne_strcmp(s, "/") != 0)
|
|
jehanne_print("newpath: %s from %#p\n", s, getcallerpc());
|
|
|
|
p->mlen = 1;
|
|
p->malen = PATHMSLOP;
|
|
p->mtpt = smalloc(p->malen*sizeof p->mtpt[0]);
|
|
return p;
|
|
}
|
|
|
|
static Path*
|
|
copypath(Path *p)
|
|
{
|
|
int i;
|
|
Path *pp;
|
|
|
|
pp = smalloc(sizeof(Path));
|
|
pp->r.ref = 1;
|
|
incref(&npath);
|
|
DBG("copypath %s %#p => %#p\n", p->s, p, pp);
|
|
|
|
pp->len = p->len;
|
|
pp->alen = p->alen;
|
|
pp->s = smalloc(p->alen);
|
|
jehanne_memmove(pp->s, p->s, p->len+1);
|
|
|
|
pp->mlen = p->mlen;
|
|
pp->malen = p->malen;
|
|
pp->mtpt = smalloc(p->malen*sizeof pp->mtpt[0]);
|
|
for(i=0; i<pp->mlen; i++){
|
|
pp->mtpt[i] = p->mtpt[i];
|
|
if(pp->mtpt[i])
|
|
incref(&pp->mtpt[i]->r);
|
|
}
|
|
|
|
return pp;
|
|
}
|
|
|
|
void
|
|
pathclose(Path *p)
|
|
{
|
|
int i;
|
|
|
|
if(p == nil)
|
|
return;
|
|
//XXX
|
|
DBG("pathclose %#p %s ref=%d =>", p, p->s, p->r.ref);
|
|
for(i=0; i<p->mlen; i++)
|
|
DBG(" %#p", p->mtpt[i]);
|
|
DBG("\n");
|
|
|
|
if(decref(&p->r))
|
|
return;
|
|
decref(&npath);
|
|
jehanne_free(p->s);
|
|
for(i=0; i<p->mlen; i++)
|
|
if(p->mtpt[i])
|
|
cclose(p->mtpt[i]);
|
|
jehanne_free(p->mtpt);
|
|
jehanne_free(p);
|
|
}
|
|
|
|
/*
|
|
* In place, rewrite name to compress multiple /, eliminate ., and process ..
|
|
* (Really only called to remove a trailing .. that has been added.
|
|
* Otherwise would need to update n->mtpt as well.)
|
|
*/
|
|
static void
|
|
fixdotdotname(Path *p)
|
|
{
|
|
char *r;
|
|
|
|
if(p->s[0] == '#'){
|
|
r = jehanne_strchr(p->s, '/');
|
|
if(r == nil)
|
|
return;
|
|
jehanne_cleanname(r);
|
|
|
|
/*
|
|
* The correct name is #i rather than #i/,
|
|
* but the correct name of #/ is #/.
|
|
*/
|
|
if(jehanne_strcmp(r, "/")==0 && p->s[1] != '/')
|
|
*r = '\0';
|
|
}else
|
|
jehanne_cleanname(p->s);
|
|
p->len = jehanne_strlen(p->s);
|
|
}
|
|
|
|
static Path*
|
|
uniquepath(Path *p)
|
|
{
|
|
Path *new;
|
|
|
|
if(p->r.ref > 1){
|
|
/* copy on write */
|
|
new = copypath(p);
|
|
pathclose(p);
|
|
p = new;
|
|
}
|
|
return p;
|
|
}
|
|
|
|
static Path*
|
|
addelem(Path *p, char *s, Chan *from)
|
|
{
|
|
char *t;
|
|
int a, i;
|
|
Chan *c, **tt;
|
|
|
|
if(s[0]=='.' && s[1]=='\0')
|
|
return p;
|
|
|
|
p = uniquepath(p);
|
|
|
|
i = jehanne_strlen(s);
|
|
if(p->len+1+i+1 > p->alen){
|
|
a = p->len+1+i+1 + PATHSLOP;
|
|
t = smalloc(a);
|
|
jehanne_memmove(t, p->s, p->len+1);
|
|
jehanne_free(p->s);
|
|
p->s = t;
|
|
p->alen = a;
|
|
}
|
|
/* don't insert extra slash if one is present */
|
|
if(p->len>0 && p->s[p->len-1]!='/' && s[0]!='/')
|
|
p->s[p->len++] = '/';
|
|
jehanne_memmove(p->s+p->len, s, i+1);
|
|
p->len += i;
|
|
if(isdotdot(s)){
|
|
fixdotdotname(p);
|
|
DBG("addelem %s .. => rm %#p\n", p->s, p->mtpt[p->mlen-1]);
|
|
if(p->mlen>1 && (c = p->mtpt[--p->mlen])){
|
|
p->mtpt[p->mlen] = nil;
|
|
cclose(c);
|
|
}
|
|
}else{
|
|
if(p->mlen >= p->malen){
|
|
p->malen = p->mlen+1+PATHMSLOP;
|
|
tt = smalloc(p->malen*sizeof tt[0]);
|
|
jehanne_memmove(tt, p->mtpt, p->mlen*sizeof tt[0]);
|
|
jehanne_free(p->mtpt);
|
|
p->mtpt = tt;
|
|
}
|
|
DBG("addelem %s %s => add %#p\n", p->s, s, from);
|
|
p->mtpt[p->mlen++] = from;
|
|
if(from)
|
|
incref(&from->r);
|
|
}
|
|
return p;
|
|
}
|
|
|
|
void
|
|
chanfree(Chan *c)
|
|
{
|
|
c->flag = CFREE;
|
|
|
|
if(c->dirrock != nil){
|
|
jehanne_free(c->dirrock);
|
|
c->dirrock = 0;
|
|
c->nrock = 0;
|
|
c->mrock = 0;
|
|
}
|
|
if(c->umh != nil){
|
|
putmhead(c->umh);
|
|
c->umh = nil;
|
|
}
|
|
if(c->umc != nil){
|
|
cclose(c->umc);
|
|
c->umc = nil;
|
|
}
|
|
if(c->mux != nil){
|
|
muxclose(c->mux);
|
|
c->mux = nil;
|
|
}
|
|
if(c->mchan != nil){
|
|
cclose(c->mchan);
|
|
c->mchan = nil;
|
|
}
|
|
|
|
if(c->dev != nil){ //XDYNX
|
|
//devtabdecr(c->dev);
|
|
c->dev = nil;
|
|
}
|
|
|
|
pathclose(c->path);
|
|
c->path = nil;
|
|
|
|
lock(&chanalloc);
|
|
c->next = chanalloc.free;
|
|
chanalloc.free = c;
|
|
unlock(&chanalloc);
|
|
}
|
|
|
|
void
|
|
cclose(Chan *c)
|
|
{
|
|
if(c == nil || c->r.ref < 1 || c->flag&CFREE)
|
|
panic("cclose %#p", getcallerpc());
|
|
|
|
DBG("cclose %#p name=%s ref=%d\n", c, c->path->s, c->r.ref);
|
|
if(decref(&c->r))
|
|
return;
|
|
|
|
if(!waserror()){
|
|
if(c->dev != nil) //XDYNX
|
|
c->dev->close(c);
|
|
poperror();
|
|
}
|
|
chanfree(c);
|
|
}
|
|
|
|
/*
|
|
* Queue a chan to be closed by one of the clunk procs.
|
|
*/
|
|
struct {
|
|
Chan *head;
|
|
Chan *tail;
|
|
Lock l;
|
|
QLock q;
|
|
Rendez r;
|
|
int active;
|
|
int running;
|
|
} clunkq;
|
|
|
|
static void closeproc(void*);
|
|
|
|
void
|
|
ccloseq(Chan *c)
|
|
{
|
|
int32_t seq;
|
|
|
|
if(c == nil || c->r.ref < 1 || c->flag&CFREE)
|
|
panic("ccloseq %#p", getcallerpc());
|
|
|
|
DBG("ccloseq %#p name=%s ref=%d\n", c, chanpath(c), c->r.ref);
|
|
|
|
if(decref(&c->r))
|
|
return;
|
|
|
|
lock(&clunkq.l);
|
|
c->next = nil;
|
|
if(clunkq.head != nil)
|
|
clunkq.tail->next = c;
|
|
else
|
|
clunkq.head = c;
|
|
clunkq.tail = c;
|
|
unlock(&clunkq.l);
|
|
|
|
if(!wakeup(&clunkq.r)){
|
|
seq = ainc(&clunkq.active);
|
|
if(seq < 10)
|
|
kproc("closeproc", closeproc, (void*)(uintptr_t)seq);
|
|
else
|
|
adec(&clunkq.active);
|
|
}
|
|
}
|
|
|
|
static int
|
|
clunkwork(void* _1)
|
|
{
|
|
return clunkq.head != nil;
|
|
}
|
|
|
|
static void
|
|
closeproc(void *a)
|
|
{
|
|
Chan *c;
|
|
int seq;
|
|
|
|
seq = (uintptr_t)a;
|
|
for(;;){
|
|
ainc(&clunkq.running);
|
|
qlock(&clunkq.q);
|
|
while(clunkq.head == nil){
|
|
if(!waserror()){
|
|
tsleep(&clunkq.r, clunkwork, nil, 5000);
|
|
poperror();
|
|
}
|
|
}
|
|
lock(&clunkq.l);
|
|
c = clunkq.head;
|
|
clunkq.head = c->next;
|
|
unlock(&clunkq.l);
|
|
qunlock(&clunkq.q);
|
|
if(!waserror()){
|
|
if(c->dev != nil) //XDYNX
|
|
c->dev->close(c);
|
|
poperror();
|
|
}
|
|
chanfree(c);
|
|
if(adec(&clunkq.running) >= 5 && seq > 5){
|
|
adec(&clunkq.active);
|
|
pexit("", 1);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Make sure we have the only copy of c. (Copy on write.)
|
|
*/
|
|
Chan*
|
|
cunique(Chan *c)
|
|
{
|
|
Chan *nc;
|
|
|
|
if(c->r.ref != 1){
|
|
nc = cclone(c);
|
|
cclose(c);
|
|
c = nc;
|
|
}
|
|
|
|
return c;
|
|
}
|
|
|
|
int
|
|
eqqid(Qid a, Qid b)
|
|
{
|
|
return a.path == b.path && a.vers == b.vers;
|
|
}
|
|
|
|
static int
|
|
eqchan(Chan *a, Chan *b, int skipvers)
|
|
{
|
|
if(a->qid.path != b->qid.path)
|
|
return 0;
|
|
if(!skipvers && a->qid.vers != b->qid.vers)
|
|
return 0;
|
|
if(a->dev->dc != b->dev->dc)
|
|
return 0;
|
|
if(a->devno != b->devno)
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
int
|
|
eqchanddq(Chan *c, int dc, uint32_t devno, Qid qid, int skipvers)
|
|
{
|
|
if(c->qid.path != qid.path)
|
|
return 0;
|
|
if(!skipvers && c->qid.vers != qid.vers)
|
|
return 0;
|
|
if(c->dev->dc != dc)
|
|
return 0;
|
|
if(c->devno != devno)
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
Mhead*
|
|
newmhead(Chan *from)
|
|
{
|
|
Mhead *mh;
|
|
|
|
mh = smalloc(sizeof(Mhead));
|
|
mh->r.ref = 1;
|
|
mh->from = from;
|
|
incref(&from->r);
|
|
return mh;
|
|
}
|
|
|
|
int
|
|
cmount(Chan **newp, Chan *old, int flag, char *spec)
|
|
{
|
|
int order, flg;
|
|
Chan *new;
|
|
Mhead *mhead, **l, *mh;
|
|
Mount *nm, *f, *um, **h;
|
|
Pgrp *pg;
|
|
|
|
order = flag&MORDER;
|
|
|
|
if(order != MREPL && (QTDIR & (old->qid.type^(*newp)->qid.type)))
|
|
error(Emount);
|
|
|
|
if(old->umh)
|
|
jehanne_print("cmount: unexpected umh, caller %#p\n", getcallerpc());
|
|
|
|
if(!(old->qid.type & QTDIR) && order != MREPL)
|
|
error(Emount);
|
|
|
|
new = *newp;
|
|
mh = new->umh;
|
|
|
|
/*
|
|
* Not allowed to bind when the old directory is itself a union.
|
|
* (Maybe it should be allowed, but I don't see what the semantics
|
|
* would be.)
|
|
*
|
|
* We need to check mh->mount->next to tell unions apart from
|
|
* simple mount points, so that things like
|
|
* mount -c fd /root
|
|
* bind -c /root /
|
|
* work.
|
|
*
|
|
* The check of mount->mflag allows things like
|
|
* mount fd /root
|
|
* bind -c /root /
|
|
*
|
|
* This is far more complicated than it should be, but I don't
|
|
* see an easier way at the moment.
|
|
*/
|
|
if((flag&MCREATE) && mh && mh->mount
|
|
&& (mh->mount->next || !(mh->mount->mflag&MCREATE)))
|
|
error(Emount);
|
|
|
|
pg = up->pgrp;
|
|
wlock(&pg->ns);
|
|
|
|
l = &MOUNTH(pg, old->qid);
|
|
for(mhead = *l; mhead; mhead = mhead->hash){
|
|
if(eqchan(mhead->from, old, 1))
|
|
break;
|
|
l = &mhead->hash;
|
|
}
|
|
|
|
if(mhead == nil){
|
|
/*
|
|
* nothing mounted here yet. create a mount
|
|
* head and add to the hash table.
|
|
*/
|
|
mhead = newmhead(old);
|
|
*l = mhead;
|
|
|
|
/*
|
|
* if this is a union mount, add the old
|
|
* node to the mount chain.
|
|
*/
|
|
if(order != MREPL)
|
|
mhead->mount = newmount(mhead, old, 0, 0);
|
|
}
|
|
wlock(&mhead->lock);
|
|
if(waserror()){
|
|
wunlock(&mhead->lock);
|
|
nexterror();
|
|
}
|
|
wunlock(&pg->ns);
|
|
|
|
nm = newmount(mhead, new, flag, spec);
|
|
if(mh != nil && mh->mount != nil){
|
|
/*
|
|
* copy a union when binding it onto a directory
|
|
*/
|
|
flg = order;
|
|
if(order == MREPL)
|
|
flg = MAFTER;
|
|
h = &nm->next;
|
|
um = mh->mount;
|
|
for(um = um->next; um; um = um->next){
|
|
f = newmount(mhead, um->to, flg, um->spec);
|
|
*h = f;
|
|
h = &f->next;
|
|
}
|
|
}
|
|
|
|
if(mhead->mount && order == MREPL){
|
|
mountfree(mhead->mount);
|
|
mhead->mount = 0;
|
|
}
|
|
|
|
if(flag & MCREATE)
|
|
nm->mflag |= MCREATE;
|
|
|
|
if(mhead->mount && order == MAFTER){
|
|
for(f = mhead->mount; f->next; f = f->next)
|
|
;
|
|
f->next = nm;
|
|
}else{
|
|
for(f = nm; f->next; f = f->next)
|
|
;
|
|
f->next = mhead->mount;
|
|
mhead->mount = nm;
|
|
}
|
|
|
|
wunlock(&mhead->lock);
|
|
poperror();
|
|
return nm->mountid;
|
|
}
|
|
|
|
void
|
|
cunmount(Chan *mnt, Chan *mounted)
|
|
{
|
|
Pgrp *pg;
|
|
Mhead *mh, **l;
|
|
Mount *f, **p;
|
|
|
|
if(mnt->umh) /* should not happen */
|
|
jehanne_print("cunmount newp extra umh %#p has %#p\n", mnt, mnt->umh);
|
|
|
|
/*
|
|
* It _can_ happen that mounted->umh is non-nil,
|
|
* because mounted is the result of namec(Aopen)
|
|
* (see sysfile.c:/^sysunmount).
|
|
* If we open a union directory, it will have a umh.
|
|
* Although surprising, this is okay, since the
|
|
* cclose will take care of freeing the umh.
|
|
*/
|
|
|
|
pg = up->pgrp;
|
|
wlock(&pg->ns);
|
|
|
|
l = &MOUNTH(pg, mnt->qid);
|
|
for(mh = *l; mh; mh = mh->hash){
|
|
if(eqchan(mh->from, mnt, 1))
|
|
break;
|
|
l = &mh->hash;
|
|
}
|
|
|
|
if(mh == 0){
|
|
wunlock(&pg->ns);
|
|
error(Eunmount);
|
|
}
|
|
|
|
wlock(&mh->lock);
|
|
if(mounted == 0){
|
|
*l = mh->hash;
|
|
wunlock(&pg->ns);
|
|
mountfree(mh->mount);
|
|
mh->mount = nil;
|
|
cclose(mh->from);
|
|
wunlock(&mh->lock);
|
|
putmhead(mh);
|
|
return;
|
|
}
|
|
|
|
p = &mh->mount;
|
|
for(f = *p; f; f = f->next){
|
|
/* BUG: Needs to be 2 pass */
|
|
if(eqchan(f->to, mounted, 1) ||
|
|
(f->to->mchan && eqchan(f->to->mchan, mounted, 1))){
|
|
*p = f->next;
|
|
f->next = 0;
|
|
mountfree(f);
|
|
if(mh->mount == nil){
|
|
*l = mh->hash;
|
|
cclose(mh->from);
|
|
wunlock(&mh->lock);
|
|
wunlock(&pg->ns);
|
|
putmhead(mh);
|
|
return;
|
|
}
|
|
wunlock(&mh->lock);
|
|
wunlock(&pg->ns);
|
|
return;
|
|
}
|
|
p = &f->next;
|
|
}
|
|
wunlock(&mh->lock);
|
|
wunlock(&pg->ns);
|
|
error(Eunion);
|
|
}
|
|
|
|
Chan*
|
|
cclone(Chan *c)
|
|
{
|
|
Chan *nc;
|
|
Walkqid *wq;
|
|
|
|
if(c == nil || c->r.ref < 1 || c->flag&CFREE)
|
|
panic("cclone: %#p", getcallerpc());
|
|
wq = c->dev->walk(c, nil, nil, 0); //XDYNX?
|
|
if(wq == nil)
|
|
error("clone failed");
|
|
nc = wq->clone;
|
|
jehanne_free(wq);
|
|
nc->path = c->path;
|
|
if(c->path)
|
|
incref(&c->path->r);
|
|
return nc;
|
|
}
|
|
|
|
/* also used by sysfile.c:/^mountfix */
|
|
int
|
|
findmount(Chan **cp, Mhead **mp, int dc, uint32_t devno, Qid qid)
|
|
{
|
|
Pgrp *pg;
|
|
Mhead *mh;
|
|
|
|
pg = up->pgrp;
|
|
rlock(&pg->ns);
|
|
for(mh = MOUNTH(pg, qid); mh; mh = mh->hash){
|
|
rlock(&mh->lock);
|
|
if(mh->from == nil){
|
|
jehanne_print("mh %#p: mh->from nil\n", mh);
|
|
runlock(&mh->lock);
|
|
continue;
|
|
}
|
|
if(eqchanddq(mh->from, dc, devno, qid, 1)){
|
|
runlock(&pg->ns);
|
|
if(mp != nil){
|
|
incref(&mh->r);
|
|
if(*mp != nil)
|
|
putmhead(*mp);
|
|
*mp = mh;
|
|
}
|
|
if(*cp != nil)
|
|
cclose(*cp);
|
|
incref(&mh->mount->to->r);
|
|
*cp = mh->mount->to;
|
|
runlock(&mh->lock);
|
|
return 1;
|
|
}
|
|
runlock(&mh->lock);
|
|
}
|
|
|
|
runlock(&pg->ns);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Calls findmount but also updates path.
|
|
*/
|
|
static int
|
|
domount(Chan **cp, Mhead **mp, Path **path)
|
|
{
|
|
Chan **lc;
|
|
Path *p;
|
|
|
|
if(findmount(cp, mp, (*cp)->dev->dc, (*cp)->devno, (*cp)->qid) == 0)
|
|
return 0;
|
|
|
|
if(path){
|
|
p = *path;
|
|
p = uniquepath(p);
|
|
if(p->mlen <= 0)
|
|
jehanne_print("domount: path %s has mlen==%d\n", p->s, p->mlen);
|
|
else{
|
|
lc = &p->mtpt[p->mlen-1];
|
|
DBG("domount %#p %s => add %#p (was %#p)\n",
|
|
p, p->s, (*mp)->from, p->mtpt[p->mlen-1]);
|
|
incref(&(*mp)->from->r);
|
|
if(*lc)
|
|
cclose(*lc);
|
|
*lc = (*mp)->from;
|
|
}
|
|
*path = p;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* If c is the right-hand-side of a mount point, returns the left hand side.
|
|
* Changes name to reflect the fact that we've uncrossed the mountpoint,
|
|
* so name had better be ours to change!
|
|
*/
|
|
static Chan*
|
|
undomount(Chan *c, Path *path)
|
|
{
|
|
Chan *nc;
|
|
|
|
if(path->r.ref != 1 || path->mlen == 0)
|
|
jehanne_print("undomount: path %s ref %d mlen %d caller %#p\n",
|
|
path->s, path->r.ref, path->mlen, getcallerpc());
|
|
|
|
if(path->mlen>0 && (nc=path->mtpt[path->mlen-1]) != nil){
|
|
DBG("undomount %#p %s => remove %p\n", path, path->s, nc);
|
|
cclose(c);
|
|
path->mtpt[path->mlen-1] = nil;
|
|
c = nc;
|
|
}
|
|
return c;
|
|
}
|
|
|
|
/*
|
|
* Call dev walk but catch errors.
|
|
*/
|
|
static Walkqid*
|
|
ewalk(Chan *c, Chan *nc, char **name, int nname)
|
|
{
|
|
Walkqid *wq;
|
|
|
|
if(waserror())
|
|
return nil;
|
|
wq = c->dev->walk(c, nc, name, nname);
|
|
poperror();
|
|
return wq;
|
|
}
|
|
|
|
/*
|
|
* Either walks all the way or not at all. No partial results in *cp.
|
|
* *nerror is the number of names to display in an error message.
|
|
*/
|
|
static char Edoesnotexist[] = "does not exist";
|
|
int
|
|
walk(Chan **cp, char **names, int nnames, int nomount, int *nerror)
|
|
{
|
|
int dc, devno, didmount, dotdot, i, n, nhave, ntry;
|
|
Chan *c, *nc, *mtpt;
|
|
Path *path;
|
|
Mhead *mh, *nmh;
|
|
Mount *f;
|
|
Walkqid *wq;
|
|
|
|
c = *cp;
|
|
incref(&c->r);
|
|
path = c->path;
|
|
incref(&path->r);
|
|
mh = nil;
|
|
|
|
/*
|
|
* While we haven't gotten all the way down the path:
|
|
* 1. step through a mount point, if any
|
|
* 2. send a walk request for initial dotdot or initial prefix without dotdot
|
|
* 3. move to the first mountpoint along the way.
|
|
* 4. repeat.
|
|
*
|
|
* Each time through the loop:
|
|
*
|
|
* If didmount==0, c is on the undomount side of the mount point.
|
|
* If didmount==1, c is on the domount side of the mount point.
|
|
* Either way, c's full path is path.
|
|
*/
|
|
didmount = 0;
|
|
for(nhave=0; nhave<nnames; nhave+=n){
|
|
if(!(c->qid.type & QTDIR)){
|
|
if(nerror)
|
|
*nerror = nhave;
|
|
pathclose(path);
|
|
cclose(c);
|
|
jehanne_strcpy(up->errstr, Enotdir);
|
|
putmhead(mh);
|
|
return -1;
|
|
}
|
|
ntry = nnames - nhave;
|
|
if(ntry > MAXWELEM)
|
|
ntry = MAXWELEM;
|
|
dotdot = 0;
|
|
for(i=0; i<ntry; i++){
|
|
if(isdotdot(names[nhave+i])){
|
|
if(i==0){
|
|
dotdot = 1;
|
|
ntry = 1;
|
|
}else
|
|
ntry = i;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if(!dotdot && !nomount && !didmount)
|
|
domount(&c, &mh, &path);
|
|
|
|
dc = c->dev->dc;
|
|
devno = c->devno;
|
|
|
|
if((wq = ewalk(c, nil, names+nhave, ntry)) == nil){
|
|
/* try a union mount, if any */
|
|
if(mh && !nomount){
|
|
/*
|
|
* mh->mount->to == c, so start at mh->mount->next
|
|
*/
|
|
rlock(&mh->lock);
|
|
if(mh->mount != nil){
|
|
for(f = mh->mount->next; f != nil; f = f->next){
|
|
if((wq = ewalk(f->to, nil, names+nhave, ntry)) != nil){
|
|
dc = f->to->dev->dc;
|
|
devno = f->to->devno;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
runlock(&mh->lock);
|
|
}
|
|
if(wq == nil){
|
|
cclose(c);
|
|
pathclose(path);
|
|
if(nerror)
|
|
*nerror = nhave+1;
|
|
putmhead(mh);
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
nmh = nil;
|
|
didmount = 0;
|
|
if(dotdot){
|
|
assert(wq->nqid == 1);
|
|
assert(wq->clone != nil);
|
|
|
|
path = addelem(path, "..", nil);
|
|
nc = undomount(wq->clone, path);
|
|
n = 1;
|
|
}else{
|
|
nc = nil;
|
|
if(!nomount){
|
|
for(i=0; i<wq->nqid && i<ntry-1; i++){
|
|
if(findmount(&nc, &nmh, dc, devno, wq->qid[i])){
|
|
didmount = 1;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
if(nc == nil){ /* no mount points along path */
|
|
if(wq->clone == nil){
|
|
cclose(c);
|
|
pathclose(path);
|
|
if(wq->nqid==0 || (wq->qid[wq->nqid-1].type & QTDIR)){
|
|
if(nerror)
|
|
*nerror = nhave+wq->nqid+1;
|
|
jehanne_strcpy(up->errstr, Edoesnotexist);
|
|
}else{
|
|
if(nerror)
|
|
*nerror = nhave+wq->nqid;
|
|
jehanne_strcpy(up->errstr, Enotdir);
|
|
}
|
|
jehanne_free(wq);
|
|
putmhead(mh);
|
|
return -1;
|
|
}
|
|
n = wq->nqid;
|
|
nc = wq->clone;
|
|
}else{ /* stopped early, at a mount point */
|
|
didmount = 1;
|
|
if(wq->clone != nil){
|
|
cclose(wq->clone);
|
|
wq->clone = nil;
|
|
}
|
|
n = i+1;
|
|
}
|
|
for(i=0; i<n; i++){
|
|
mtpt = nil;
|
|
if(i==n-1 && nmh)
|
|
mtpt = nmh->from;
|
|
path = addelem(path, names[nhave+i], mtpt);
|
|
}
|
|
}
|
|
cclose(c);
|
|
c = nc;
|
|
putmhead(mh);
|
|
mh = nmh;
|
|
jehanne_free(wq);
|
|
}
|
|
|
|
putmhead(mh);
|
|
|
|
c = cunique(c);
|
|
|
|
if(c->umh != nil){ //BUG
|
|
jehanne_print("walk umh\n");
|
|
putmhead(c->umh);
|
|
c->umh = nil;
|
|
}
|
|
|
|
pathclose(c->path);
|
|
c->path = path;
|
|
|
|
cclose(*cp);
|
|
*cp = c;
|
|
if(nerror)
|
|
*nerror = nhave;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* c is a mounted non-creatable directory. find a creatable one.
|
|
*/
|
|
Chan*
|
|
createdir(Chan *c, Mhead *mh)
|
|
{
|
|
Chan *nc;
|
|
Mount *f;
|
|
|
|
rlock(&mh->lock);
|
|
if(waserror()){
|
|
runlock(&mh->lock);
|
|
nexterror();
|
|
}
|
|
for(f = mh->mount; f; f = f->next){
|
|
if(f->mflag&MCREATE){
|
|
nc = cclone(f->to);
|
|
runlock(&mh->lock);
|
|
poperror();
|
|
cclose(c);
|
|
return nc;
|
|
}
|
|
}
|
|
error(Enocreate);
|
|
return 0;
|
|
}
|
|
|
|
static void
|
|
saveregisters(void)
|
|
{
|
|
}
|
|
|
|
static void
|
|
growparse(Elemlist *e)
|
|
{
|
|
char **new;
|
|
int *inew;
|
|
enum { Delta = 8 };
|
|
|
|
if(e->nelems % Delta == 0){
|
|
new = smalloc((e->nelems+Delta) * sizeof(char*));
|
|
jehanne_memmove(new, e->elems, e->nelems*sizeof(char*));
|
|
jehanne_free(e->elems);
|
|
e->elems = new;
|
|
inew = smalloc((e->nelems+Delta+1) * sizeof(int));
|
|
jehanne_memmove(inew, e->off, (e->nelems+1)*sizeof(int));
|
|
jehanne_free(e->off);
|
|
e->off = inew;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* The name is known to be valid.
|
|
* Copy the name so slashes can be overwritten.
|
|
* An empty string will set nelem=0.
|
|
* A path ending in / or /. or /.//./ etc. will have
|
|
* e.mustbedir = 1, so that we correctly
|
|
* reject, e.g., "/adm/users/." when /adm/users is a file
|
|
* rather than a directory.
|
|
*/
|
|
static void
|
|
parsename(char *aname, Elemlist *e)
|
|
{
|
|
char *name, *slash;
|
|
|
|
kstrdup(&e->name, aname);
|
|
name = e->name;
|
|
e->nelems = 0;
|
|
e->elems = nil;
|
|
e->off = smalloc(sizeof(int));
|
|
e->off[0] = skipslash(name) - name;
|
|
for(;;){
|
|
name = skipslash(name);
|
|
if(*name == '\0'){
|
|
e->off[e->nelems] = name+jehanne_strlen(name) - e->name;
|
|
e->mustbedir = 1;
|
|
break;
|
|
}
|
|
growparse(e);
|
|
e->elems[e->nelems++] = name;
|
|
slash = jehanne_utfrune(name, '/');
|
|
if(slash == nil){
|
|
e->off[e->nelems] = name+jehanne_strlen(name) - e->name;
|
|
e->mustbedir = 0;
|
|
break;
|
|
}
|
|
e->off[e->nelems] = slash - e->name;
|
|
*slash++ = '\0';
|
|
name = slash;
|
|
}
|
|
|
|
if(DBGFLG > 1){
|
|
int i;
|
|
|
|
DBG("parsename %s:", e->name);
|
|
for(i=0; i<=e->nelems; i++)
|
|
DBG(" %d", e->off[i]);
|
|
DBG("\n");
|
|
}
|
|
}
|
|
|
|
static void*
|
|
memrchr(void *va, int c, long n)
|
|
{
|
|
uint8_t *a, *e;
|
|
|
|
a = va;
|
|
for(e=a+n-1; e>a; e--)
|
|
if(*e == c)
|
|
return e;
|
|
return nil;
|
|
}
|
|
|
|
static void
|
|
namelenerror(char *aname, int len, char *err)
|
|
{
|
|
char *ename, *name, *next;
|
|
int i, errlen;
|
|
|
|
/*
|
|
* If the name is short enough, just use the whole thing.
|
|
*/
|
|
errlen = jehanne_strlen(err);
|
|
if(len < ERRMAX/3 || len+errlen < 2*ERRMAX/3)
|
|
jehanne_snprint(up->genbuf, sizeof up->genbuf, "%.*s",
|
|
jehanne_utfnlen(aname, len), aname);
|
|
else{
|
|
/*
|
|
* Print a suffix of the name, but try to get a little info.
|
|
*/
|
|
ename = aname+len;
|
|
next = ename;
|
|
do{
|
|
name = next;
|
|
next = memrchr(aname, '/', name-aname);
|
|
if(next == nil)
|
|
next = aname;
|
|
len = ename-next;
|
|
}while(len < ERRMAX/3 || len + errlen < 2*ERRMAX/3);
|
|
|
|
/*
|
|
* If the name is ridiculously long, chop it.
|
|
*/
|
|
if(name == ename){
|
|
name = ename-ERRMAX/4;
|
|
if(name <= aname)
|
|
panic("bad math in namelenerror");
|
|
/* walk out of current UTF sequence */
|
|
for(i=0; (*name&0xC0)==0x80 && i<UTFmax; i++)
|
|
name++;
|
|
}
|
|
jehanne_snprint(up->genbuf, sizeof up->genbuf, "...%.*s",
|
|
jehanne_utfnlen(name, ename-name), name);
|
|
}
|
|
jehanne_snprint(up->errstr, ERRMAX, "%#q %s", up->genbuf, err);
|
|
nexterror();
|
|
}
|
|
|
|
void
|
|
nameerror(char *name, char *err)
|
|
{
|
|
namelenerror(name, jehanne_strlen(name), err);
|
|
}
|
|
|
|
/*
|
|
* Turn a name into a channel.
|
|
* &name[0] is known to be a valid address. It may be a kernel address.
|
|
*
|
|
* Opening with amode Aopen, Acreate, Aremove, or Aaccess guarantees
|
|
* that the result will be the only reference to that particular fid.
|
|
* This is necessary since we might pass the result to
|
|
* devtab[]->remove().
|
|
*
|
|
* Opening Atodir or Amount does not guarantee this.
|
|
*
|
|
* Under certain circumstances, opening Aaccess will cause
|
|
* an unnecessary clone in order to get a cunique Chan so it
|
|
* can attach the correct name. Sysstat and sys_stat need the
|
|
* correct name so they can rewrite the stat info.
|
|
*/
|
|
Chan*
|
|
namec(char *aname, int amode, long omode, long perm)
|
|
{
|
|
int len, n, nomount;
|
|
Chan *c, *cnew;
|
|
Path *path;
|
|
Elemlist e;
|
|
Rune r;
|
|
Mhead *mh;
|
|
char tmperrbuf[ERRMAX];
|
|
char *name;
|
|
Dev *dev;
|
|
|
|
if(aname[0] == '\0')
|
|
error("empty file name");
|
|
aname = validnamedup(aname, 1);
|
|
if(waserror()){
|
|
jehanne_free(aname);
|
|
nexterror();
|
|
}
|
|
DBG("namec %s %d %d\n", aname, amode, omode);
|
|
name = aname;
|
|
|
|
/*
|
|
* Find the starting off point (the current slash, the root of
|
|
* a device tree, or the current dot) as well as the name to
|
|
* evaluate starting there.
|
|
*/
|
|
nomount = 0;
|
|
switch(name[0]){
|
|
case '/':
|
|
c = up->slash;
|
|
incref(&c->r);
|
|
break;
|
|
|
|
case '#':
|
|
nomount = 1;
|
|
n = 0;
|
|
if(name[1] == '*'){
|
|
name += 2;
|
|
while(*name != '\0' && *name != '/' && *name != '!'){
|
|
if(n >= sizeof(up->genbuf)-1)
|
|
error(Efilename);
|
|
up->genbuf[n++] = *name++;
|
|
}
|
|
up->genbuf[n] = '\0';
|
|
dev = devbyname(up->genbuf);
|
|
if(dev == nil)
|
|
error(Ebadsharp);
|
|
r = dev->dc;
|
|
up->genbuf[0] = '#';
|
|
n = 1+jehanne_runetochar(up->genbuf+1, &r);
|
|
if(*name == '!'){
|
|
name++;
|
|
while(*name != '\0' && *name != '/'){
|
|
if(n >= sizeof(up->genbuf)-1)
|
|
error(Efilename);
|
|
up->genbuf[n++] = *name++;
|
|
}
|
|
}
|
|
up->genbuf[n] = '\0';
|
|
}else{
|
|
n = 0;
|
|
while(*name != '\0' && (*name != '/' || n < 2)){
|
|
if(n >= sizeof(up->genbuf)-1)
|
|
error(Efilename);
|
|
up->genbuf[n++] = *name++;
|
|
}
|
|
up->genbuf[n] = '\0';
|
|
n = jehanne_chartorune(&r, up->genbuf+1)+1;
|
|
}
|
|
/* actually / is caught by parsing earlier */
|
|
if(jehanne_utfrune("9", r))
|
|
error(Enoattach);
|
|
/*
|
|
* noattach is sandboxing.
|
|
*
|
|
* the OK exceptions are:
|
|
* | current process's pipes
|
|
* 0 current process's kernel infos
|
|
* d current process's file descriptors
|
|
* e current process's environment
|
|
* NOTE: Plan9 also allows
|
|
* c time and pid, but also cons and consctl
|
|
* p control of your own processes (and unfortunately
|
|
* any others left unprotected)
|
|
* but Jehanne disable them to improve security.
|
|
*
|
|
* Who actually need them can bind #c and #p somewhere
|
|
* before sys_rfork(RFNOMNT)
|
|
*/
|
|
if(up->pgrp->noattach && jehanne_utfrune("|0de", r)==nil)
|
|
error(Enoattach);
|
|
dev = devtabget(r, 1); //XDYNX
|
|
if(dev == nil)
|
|
error(Ebadsharp);
|
|
c = dev->attach(nil, nil, up->genbuf+n, 0);
|
|
break;
|
|
|
|
default:
|
|
c = up->dot;
|
|
incref(&c->r);
|
|
break;
|
|
}
|
|
|
|
e.aname = aname;
|
|
e.prefix = name - aname;
|
|
e.name = nil;
|
|
e.elems = nil;
|
|
e.off = nil;
|
|
e.nelems = 0;
|
|
e.nerror = 0;
|
|
if(waserror()){
|
|
cclose(c);
|
|
jehanne_free(e.name);
|
|
jehanne_free(e.elems);
|
|
/*
|
|
* Prepare nice error, showing first e.nerror elements of name.
|
|
*/
|
|
if(e.nerror == 0)
|
|
nexterror();
|
|
jehanne_strcpy(tmperrbuf, up->errstr);
|
|
if(e.off[e.nerror]==0)
|
|
jehanne_print("nerror=%d but off=%d\n",
|
|
e.nerror, e.off[e.nerror]);
|
|
if(DBGFLG > 0){
|
|
DBG("showing %d+%d/%d (of %d) of %s (%d %d)\n",
|
|
e.prefix, e.off[e.nerror], e.nerror,
|
|
e.nelems, aname, e.off[0], e.off[1]);
|
|
}
|
|
len = e.prefix+e.off[e.nerror];
|
|
jehanne_free(e.off);
|
|
namelenerror(aname, len, tmperrbuf);
|
|
}
|
|
|
|
/*
|
|
* Build a list of elements in the name.
|
|
*/
|
|
parsename(name, &e);
|
|
|
|
/*
|
|
* On create, ....
|
|
*/
|
|
if(amode == Acreate){
|
|
/* perm must have DMDIR if last element is / or /. */
|
|
if(e.mustbedir && !(perm&DMDIR) && omode >= 0){
|
|
e.nerror = e.nelems;
|
|
error("create without DMDIR");
|
|
}
|
|
|
|
/* don't try to walk the last path element just yet. */
|
|
if(e.nelems == 0)
|
|
error(Eexist);
|
|
e.nelems--;
|
|
}
|
|
|
|
if(walk(&c, e.elems, e.nelems, nomount, &e.nerror) < 0){
|
|
if(e.nerror < 0 || e.nerror > e.nelems){
|
|
jehanne_print("namec %s walk error nerror=%d\n", aname, e.nerror);
|
|
e.nerror = 0;
|
|
}
|
|
nexterror();
|
|
}
|
|
|
|
if(e.mustbedir && !(c->qid.type & QTDIR))
|
|
error(Enotdir);
|
|
|
|
if(amode == Aopen && (omode&7) == OEXEC && (c->qid.type & QTDIR))
|
|
error("cannot exec directory");
|
|
|
|
switch(amode){
|
|
case Abind:
|
|
/* no need to maintain path - cannot dotdot an Abind */
|
|
mh = nil;
|
|
if(!nomount)
|
|
domount(&c, &mh, nil);
|
|
if(c->umh != nil)
|
|
putmhead(c->umh);
|
|
c->umh = mh;
|
|
break;
|
|
|
|
case Aaccess:
|
|
case Aremove:
|
|
case Aopen:
|
|
/* save&update the name; domount might change c */
|
|
path = c->path;
|
|
incref(&path->r);
|
|
if(waserror()){
|
|
pathclose(path);
|
|
nexterror();
|
|
}
|
|
|
|
mh = nil;
|
|
if(!nomount)
|
|
domount(&c, &mh, &path);
|
|
|
|
/* our own copy to open or remove */
|
|
c = cunique(c);
|
|
|
|
/* now it's our copy anyway, we can put the name back */
|
|
poperror();
|
|
pathclose(c->path);
|
|
c->path = path;
|
|
|
|
/* record whether c is on a mount point */
|
|
c->ismtpt = mh!=nil;
|
|
|
|
switch(amode){
|
|
case Aaccess:
|
|
case Aremove:
|
|
putmhead(mh);
|
|
break;
|
|
|
|
case Aopen:
|
|
case Acreate:
|
|
if(c->umh != nil){
|
|
jehanne_print("cunique umh Open\n");
|
|
putmhead(c->umh);
|
|
c->umh = nil;
|
|
}
|
|
/* only save the mount head if it's a multiple element union */
|
|
if(mh && mh->mount && mh->mount->next)
|
|
c->umh = mh;
|
|
else
|
|
putmhead(mh);
|
|
|
|
/* save registers else error() in open has wrong value of c saved */
|
|
saveregisters();
|
|
|
|
c = c->dev->open(c, omode&~OCEXEC);
|
|
|
|
if(omode & OCEXEC)
|
|
c->flag |= CCEXEC;
|
|
if(omode & ORCLOSE)
|
|
c->flag |= CRCLOSE;
|
|
break;
|
|
}
|
|
break;
|
|
|
|
case Atodir:
|
|
/*
|
|
* Directories (e.g. for cd) are left before the mount point,
|
|
* so one may mount on / or . and see the effect.
|
|
*/
|
|
if(!(c->qid.type & QTDIR))
|
|
error(Enotdir);
|
|
break;
|
|
|
|
case Amount:
|
|
/*
|
|
* When mounting on an already mounted upon directory,
|
|
* one wants subsequent mounts to be attached to the
|
|
* original directory, not the replacement. Don't domount.
|
|
*/
|
|
break;
|
|
|
|
case Acreate:
|
|
/*
|
|
* We've already walked all but the last element.
|
|
* If the last exists just give up.
|
|
*/
|
|
e.nelems++;
|
|
e.nerror++;
|
|
if(walk(&c, e.elems+e.nelems-1, 1, nomount, nil) == 0)
|
|
if(omode >=0) /* a negative omode means this is a message for the server */
|
|
error(Eexist);
|
|
|
|
mh = nil;
|
|
cnew = nil; /* is this assignment necessary? */
|
|
if(!waserror()){ /* try create */
|
|
if(!nomount && findmount(&cnew, &mh, c->dev->dc, c->devno, c->qid))
|
|
cnew = createdir(cnew, mh);
|
|
else{
|
|
cnew = c;
|
|
incref(&cnew->r);
|
|
}
|
|
|
|
/*
|
|
* We need our own copy of the Chan because we're
|
|
* about to send a create, which will move it. Once we have
|
|
* our own copy, we can fix the name, which might be wrong
|
|
* if findmount gave us a new Chan.
|
|
*/
|
|
cnew = cunique(cnew);
|
|
pathclose(cnew->path);
|
|
cnew->path = c->path;
|
|
incref(&cnew->path->r);
|
|
|
|
cnew = cnew->dev->create(cnew, e.elems[e.nelems-1], omode&~(OCEXEC), perm);
|
|
poperror();
|
|
if(omode & OCEXEC)
|
|
cnew->flag |= CCEXEC;
|
|
if(omode & ORCLOSE)
|
|
cnew->flag |= CRCLOSE;
|
|
putmhead(mh);
|
|
cclose(c);
|
|
c = cnew;
|
|
c->path = addelem(c->path, e.elems[e.nelems-1], nil);
|
|
break;
|
|
}
|
|
/* create failed */
|
|
cclose(cnew);
|
|
putmhead(mh);
|
|
nexterror();
|
|
|
|
default:
|
|
panic("unknown namec access %d", amode);
|
|
}
|
|
|
|
/* place final element in genbuf for e.g. exec */
|
|
if(e.nelems > 0)
|
|
kstrcpy(up->genbuf, e.elems[e.nelems-1], sizeof up->genbuf);
|
|
else
|
|
kstrcpy(up->genbuf, ".", sizeof up->genbuf);
|
|
jehanne_free(e.name);
|
|
jehanne_free(e.elems);
|
|
jehanne_free(e.off);
|
|
poperror(); /* e c */
|
|
jehanne_free(aname);
|
|
poperror(); /* aname */
|
|
|
|
return c;
|
|
}
|
|
|
|
/*
|
|
* name is valid. skip leading / and ./ as much as possible
|
|
*/
|
|
char*
|
|
skipslash(char *name)
|
|
{
|
|
while(name[0]=='/' || (name[0]=='.' && (name[1]==0 || name[1]=='/')))
|
|
name++;
|
|
return name;
|
|
}
|
|
|
|
char isfrog[256]={
|
|
/*NUL*/ 1, 1, 1, 1, 1, 1, 1, 1,
|
|
/*BKS*/ 1, 1, 1, 1, 1, 1, 1, 1,
|
|
/*DLE*/ 1, 1, 1, 1, 1, 1, 1, 1,
|
|
/*CAN*/ 1, 1, 1, 1, 1, 1, 1, 1,
|
|
['/'] 1,
|
|
[0x7f] 1,
|
|
};
|
|
|
|
/*
|
|
* Check that the name
|
|
* a) is in valid memory.
|
|
* b) is shorter than 2^16 bytes, so it can fit in a 9P string field.
|
|
* c) contains no frogs.
|
|
* The first byte is known to be addressable by the requester, so the
|
|
* routine works for kernel and user memory both.
|
|
* The parameter slashok flags whether a slash character is an error
|
|
* or a valid character.
|
|
*
|
|
* The parameter dup flags whether the string should be copied
|
|
* out of user space before being scanned the second time.
|
|
* (Otherwise a malicious thread could remove the NUL, causing us
|
|
* to access unchecked addresses.)
|
|
*/
|
|
static char*
|
|
validname0(char *aname, int slashok, int dup, uintptr_t pc)
|
|
{
|
|
char *ename, *name, *s;
|
|
int c, n;
|
|
Rune r;
|
|
|
|
name = aname;
|
|
if(!iskaddr(name)){
|
|
if(!dup)
|
|
jehanne_print("warning: validname* called from %#p with user pointer", pc);
|
|
ename = vmemchr(name, 0, (1<<16));
|
|
}else
|
|
ename = jehanne_memchr(name, 0, (1<<16));
|
|
|
|
if(ename==nil || ename-name>=(1<<16))
|
|
error("name too long");
|
|
|
|
s = nil;
|
|
if(dup){
|
|
n = ename-name;
|
|
s = smalloc(n+1);
|
|
jehanne_memmove(s, name, n);
|
|
s[n] = 0;
|
|
aname = s;
|
|
name = s;
|
|
jehanne_setmalloctag(s, pc);
|
|
}
|
|
|
|
while(*name){
|
|
/* all characters above '~' are ok */
|
|
c = *(uint8_t*)name;
|
|
if(c >= Runeself)
|
|
name += jehanne_chartorune(&r, name);
|
|
else{
|
|
if(isfrog[c])
|
|
if(!slashok || c!='/'){
|
|
jehanne_snprint(up->genbuf, sizeof(up->genbuf), "%s: %q", Ebadchar, aname);
|
|
jehanne_free(s);
|
|
error(up->genbuf);
|
|
}
|
|
name++;
|
|
}
|
|
}
|
|
return s;
|
|
}
|
|
|
|
void
|
|
validname(char *aname, int slashok)
|
|
{
|
|
validname0(aname, slashok, 0, getcallerpc());
|
|
}
|
|
|
|
char*
|
|
validnamedup(char *aname, int slashok)
|
|
{
|
|
return validname0(aname, slashok, 1, getcallerpc());
|
|
}
|
|
|
|
void
|
|
isdir(Chan *c)
|
|
{
|
|
if(c->qid.type & QTDIR)
|
|
return;
|
|
error(Enotdir);
|
|
}
|
|
|
|
/*
|
|
* This is necessary because there are many
|
|
* pointers to the top of a given mount list:
|
|
*
|
|
* - the mhead in the namespace hash table
|
|
* - the mhead in chans returned from findmount:
|
|
* used in namec and then by unionread.
|
|
* - the mhead in chans returned from createdir:
|
|
* used in the open/create race protect, which is gone.
|
|
*
|
|
* The RWlock in the Mhead protects the mount list it contains.
|
|
* The mount list is deleted when we cunmount.
|
|
* The RWlock ensures that nothing is using the mount list at that time.
|
|
*
|
|
* It is okay to replace c->mh with whatever you want as
|
|
* long as you are sure you have a unique reference to it.
|
|
*
|
|
* This comment might belong somewhere else.
|
|
*/
|
|
void
|
|
putmhead(Mhead *mh)
|
|
{
|
|
if(mh && decref(&mh->r) == 0){
|
|
mh->mount = (Mount*)0xCafeBeef;
|
|
jehanne_free(mh);
|
|
}
|
|
}
|