ref: 482e874528c6c86e661a3e4a1b9fda12f2346385
dir: /tools/libstyx/styxserver.c/
#include <lib9.h>
#include <styx.h>
#include "styxserver.h"
#include "styxaux.h"
#define MAXSTAT 512
#define EMSGLEN 256 /* %r */
#define TABSZ 32 /* power of 2 */
static unsigned long boottime;
static char* eve = "inferno";
static int Debug = 0;
char Enomem[] = "out of memory";
char Eperm[] = "permission denied";
char Enodev[] = "no free devices";
char Ehungup[] = "write to hungup channel";
char Eexist[] = "file exists";
char Enonexist[] = "file does not exist";
char Ebadcmd[] = "bad command";
char Ebadarg[] = "bad arg in system call";
char Enofid[] = "no such fid";
char Enotdir[] = "not a directory";
char Eopen[] = "already open";
char Ebadfid[] = "bad fid";
/* client state */
enum{
CDISC = 01,
CNREAD = 02,
CRECV = 04,
};
typedef struct Walkqid Walkqid;
struct Fid
{
Client *client;
Fid *next;
short fid;
ushort open;
ushort mode; /* read/write */
ulong offset; /* in file */
int dri; /* dirread index */
Qid qid;
};
struct Walkqid
{
Fid *clone;
int nqid;
Qid qid[1];
};
#define ASSERT(A,B) styxassert((int)A,B)
static int hash(Path);
static void deletefids(Client *);
static void
styxfatal(char *fmt, ...)
{
char buf[1024], *out;
va_list arg;
out = seprint(buf, buf+sizeof(buf), "Fatal error: ");
va_start(arg, fmt);
out = vseprint(out, buf+sizeof(buf), fmt, arg);
va_end(arg);
write(2, buf, out-buf);
styxexit(1);
}
static void
styxassert(int vtrue, char *reason)
{
if(!vtrue)
styxfatal("assertion failed: %s\n", reason);
}
void *
styxmalloc(int bytes)
{
char *m = malloc(bytes);
if(m == nil)
styxfatal(Enomem);
memset(m, 0, bytes);
return m;
}
void
styxfree(void *p)
{
free(p);
}
void
styxdebug()
{
Debug = 1;
}
static Client *
newclient(Styxserver *server, int fd)
{
Client *c = (Client *)styxmalloc(sizeof(Client));
if(Debug)
fprint(2, "New client at %lux\n", (ulong)c);
c->server = server;
c->fd = fd;
c->nread = 0;
c->nc = 0;
c->state = 0;
c->fids = nil;
c->uname = strdup(eve);
c->aname = strdup("");
c->next = server->clients;
server->clients = c;
if(server->ops->newclient)
server->ops->newclient(c);
return c;
}
static void
freeclient(Client *c)
{
Client **p;
Styxserver *server;
if(Debug)
fprint(2, "Freeing client at %lux\n", (ulong)c);
server = c->server;
if(server->ops->freeclient)
server->ops->freeclient(c);
for(p = &server->clients; *p; p = &(*p)->next)
if(*p == c){
styxclosesocket(c->fd);
*p = c->next;
deletefids(c);
free(c->uname);
free(c->aname);
styxfree(c);
return;
}
}
static int
nbread(Client *c, int nr)
{
int nb;
if(c->state&CDISC)
return -1;
nb = styxrecv(c->server, c->fd, c->msg + c->nread, nr, 0);
if(nb <= 0){
c->nread = 0;
c->state |= CDISC;
return -1;
}
c->nread += nb;
return 0;
}
static int
rd(Client *c, Fcall *r)
{
if(c->nc > 0){ /* last convM2S consumed nc bytes */
c->nread -= c->nc;
if((int)c->nread < 0){
r->ename = "negative size in rd";
return -1;
}
memmove(c->msg, c->msg+c->nc, c->nread);
c->nc = 0;
}
if(c->state&CRECV){
if(nbread(c, MSGMAX - c->nread) != 0){
r->ename = "unexpected EOF";
return -1;
}
c->state &= ~CRECV;
}
c->nc = convM2S((uchar*)(c->msg), c->nread, r);
if(c->nc < 0){
r->ename = "bad message format";
return -1;
}
if(c->nc == 0 && c->nread > 0){
c->nread = 0;
c->state &= ~CNREAD;
return 0;
}
if(c->nread > c->nc)
c->state |= CNREAD;
else
c->state &= ~CNREAD;
if(c->nc == 0)
return 0;
/* fprint(2, "rd: %F\n", r); */
return 1;
}
static int
wr(Client *c, Fcall *r)
{
int n;
char buf[MSGMAX];
n = convS2M(r, (uchar*)buf, sizeof(buf));
if(n < 0){
r->ename = "bad message type in wr";
return -1;
}
/* fprint(2, "wr: %F\n", r); */
return styxsend(c->server, c->fd, buf, n, 0);
}
static void
sremove(Styxserver *server, Styxfile *f)
{
Styxfile *s, *next, **p;
if(f == nil)
return;
if(Debug)
fprint(2, "Remove file %s Qid=%llx\n", f->d.name, f->d.qid.path);
if(f->d.qid.type&QTDIR)
for(s = f->child; s != nil; s = next){
next = s->sibling;
sremove(server, s);
}
for(p = &server->ftab[hash(f->d.qid.path)]; *p; p = &(*p)->next)
if(*p == f){
*p = f->next;
break;
}
for(p = &f->parent->child; *p; p = &(*p)->sibling)
if(*p == f){
*p = f->sibling;
break;
}
styxfree(f->d.name);
styxfree(f->d.uid);
styxfree(f->d.gid);
styxfree(f);
}
int
styxrmfile(Styxserver *server, Path qid)
{
Styxfile *f;
f = styxfindfile(server, qid);
if(f != nil){
if(f->parent == nil)
return -1;
sremove(server, f);
return 0;
}
return -1;
}
static void
incref(Styxfile *f)
{
if(f != nil)
f->ref++;
}
static void
decref(Styxfile *f)
{
if(f != nil)
--f->ref;
}
static void
increff(Fid *f)
{
incref(styxfindfile(f->client->server, f->qid.path));
}
static void
decreff(Fid *f)
{
decref(styxfindfile(f->client->server, f->qid.path));
}
static void
incopen(Fid *f)
{
Styxfile *file;
if(f->open && (file = styxfindfile(f->client->server, f->qid.path)) != nil)
file->open++;
}
static void
decopen(Fid *f)
{
Styxfile *file;
if(f->open && (file = styxfindfile(f->client->server, f->qid.path)) != nil)
file->open--;
}
int
styxperm(Styxfile *f, char *uid, int mode)
{
int m, p;
p = 0;
switch(mode&3){
case OREAD: p = AREAD; break;
case OWRITE: p = AWRITE; break;
case ORDWR: p = AREAD+AWRITE; break;
case OEXEC: p = AEXEC; break;
}
if(mode&OTRUNC)
p |= AWRITE;
m = f->d.mode&7;
if((p&m) == p)
return 1;
if(strcmp(f->d.uid, uid) == 0){
m |= (f->d.mode>>6)&7;
if((p&m) == p)
return 1;
}
if(strcmp(f->d.gid, uid) == 0){
m |= (f->d.mode>>3)&7;
if((p&m) == p)
return 1;
}
return 0;
}
static int
hash(Path path)
{
return path&(TABSZ-1);
}
Styxfile *
styxfindfile(Styxserver *server, Path path)
{
Styxfile *f;
for(f = server->ftab[hash(path)]; f != nil; f = f->next){
if(f->d.qid.path == path)
return f;
}
return nil;
}
static Fid *
findfid(Client *c, short fid)
{
Fid *f;
for(f = c->fids; f && f->fid != fid; f = f->next)
;
return f;
}
static void
deletefid(Client *c, Fid *d)
{
/* TODO: end any outstanding reads on this fid */
Fid **f;
for(f = &c->fids; *f; f = &(*f)->next)
if(*f == d){
decreff(d);
decopen(d);
*f = d->next;
styxfree(d);
return;
}
}
static void
deletefids(Client *c)
{
Fid *f, *g;
for(f = c->fids; f; f = g){
decreff(f);
decopen(f);
g = f->next;
styxfree(f);
}
}
Fid *
newfid(Client *c, short fid, Qid qid){
Fid *f;
f = styxmalloc(sizeof(Fid));
ASSERT(f, "newfid");
f->client = c;
f->fid = fid;
f->open = 0;
f->dri = 0;
f->qid = qid;
f->next = c->fids;
c->fids = f;
increff(f);
return f;
}
static void
flushtag(int oldtag)
{
USED(oldtag);
}
int
eqqid(Qid a, Qid b)
{
return a.path == b.path && a.vers == b.vers;
}
static Fid *
fidclone(Fid *old, short fid)
{
Fid *new;
new = newfid(old->client, fid, old->qid);
return new;
}
static Walkqid*
devwalk(Client *c, Styxfile *file, Fid *fp, Fid *nfp, char **name, int nname, char **err)
{
Styxserver *server;
long j;
Walkqid *wq;
char *n;
Styxfile *p, *f;
Styxops *ops;
Qid qid;
*err = nil;
server = c->server;
ops = server->ops;
wq = styxmalloc(sizeof(Walkqid)+(nname-1)*sizeof(Qid));
wq->nqid = 0;
p = file;
qid = p != nil ? p->d.qid : fp->qid;
for(j = 0; j < nname; j++){
if(!(qid.type&QTDIR)){
if(j == 0)
styxfatal("devwalk error");
*err = Enotdir;
goto Done;
}
if(p != nil && !styxperm(p, c->uname, OEXEC)){
*err = Eperm;
goto Done;
}
n = name[j];
if(strcmp(n, ".") == 0){
Accept:
wq->qid[wq->nqid++] = nfp->qid;
continue;
}
if(p != nil && strcmp(n, "..") == 0 && p->parent){
decref(p);
nfp->qid.path = p->parent->d.qid.path;
nfp->qid.type = p->parent->d.qid.type;
nfp->qid.vers = 0;
incref(p->parent);
p = p->parent;
qid = p->d.qid;
goto Accept;
}
if(ops->walk != nil){
char *e;
e = ops->walk(&qid, n);
if(e == nil){
decreff(nfp);
nfp->qid = qid;
increff(nfp);
p = styxfindfile(server, qid.path);
if(server->needfile && p == nil)
goto Done;
qid = p != nil ? p->d.qid : nfp->qid;
goto Accept;
}
}
if(p != nil)
for(f = p->child; f != nil; f = f->sibling){
if(strcmp(n, f->d.name) == 0){
decref(p);
nfp->qid.path = f->d.qid.path;
nfp->qid.type = f->d.qid.type;
nfp->qid.vers = 0;
incref(f);
p = f;
qid = p->d.qid;
goto Accept;
}
}
if(j == 0 && *err == nil)
*err = Enonexist;
goto Done;
}
Done:
if(*err != nil){
styxfree(wq);
return nil;
}
return wq;
}
static long
devdirread(Fid *fp, Styxfile *file, char *d, long n)
{
long dsz, m;
Styxfile *f;
int i;
struct{
Dir d;
char slop[100]; /* TO DO */
}dir;
f = file->child;
for(i = 0; i < fp->dri; i++)
if(f == 0)
return 0;
else
f = f->sibling;
for(m = 0; m < n; fp->dri++){
if(f == nil)
break;
dir.d = f->d;
dsz = convD2M(&dir.d, (uchar*)d, n-m);
m += dsz;
d += dsz;
f = f->sibling;
}
return m;
}
static char*
nilconv(char *s)
{
if(s != nil && s[0] == '\0')
return nil;
return s;
}
static Styxfile *
newfile(Styxserver *server, Styxfile *parent, int isdir, Path qid, char *name, int mode, char *owner)
{
Styxfile *file;
Dir d;
int h;
if(qid == -1)
qid = server->qidgen++;
file = styxfindfile(server, qid);
if(file != nil)
return nil;
if(parent != nil){
for(file = parent->child; file != nil; file = file->sibling)
if(strcmp(name, file->d.name) == 0)
return nil;
}
file = (Styxfile *)styxmalloc(sizeof(Styxfile));
file->parent = parent;
file->child = nil;
h = hash(qid);
file->next = server->ftab[h];
server->ftab[h] = file;
if(parent){
file->sibling = parent->child;
parent->child = file;
}else
file->sibling = nil;
d.type = 'X';
d.dev = 'x';
d.qid.path = qid;
d.qid.type = 0;
d.qid.vers = 0;
d.mode = mode;
d.atime = time(0);
d.mtime = boottime;
d.length = 0;
d.name = strdup(name);
d.uid = strdup(owner);
d.gid = strdup(eve);
d.muid = "";
if(isdir){
d.qid.type |= QTDIR;
d.mode |= DMDIR;
}
else{
d.qid.type &= ~QTDIR;
d.mode &= ~DMDIR;
}
file->d = d;
file->ref = 0;
file->open = 0;
if(Debug)
fprint(2, "New file %s Qid=%llx\n", name, qid);
return file;
}
static void
run(Client *c)
{
Fcall f;
Fid *fp, *nfp;
int i, open, mode;
char ebuf[EMSGLEN];
Walkqid *wq;
Styxfile *file;
Dir dir;
Qid qid;
Styxops *ops;
char strs[128];
ebuf[0] = 0;
if(rd(c, &f) <= 0)
return;
if(f.type == Tflush){
flushtag(f.oldtag);
f.type = Rflush;
wr(c, &f);
return;
}
ops = c->server->ops;
file = nil;
fp = findfid(c, f.fid);
if(f.type != Tversion && f.type != Tauth && f.type != Tattach){
if(fp == nil){
f.type = Rerror;
f.ename = Enofid;
wr(c, &f);
return;
}
else{
file = styxfindfile(c->server, fp->qid.path);
if(c->server->needfile && file == nil){
f.type = Rerror;
f.ename = Enonexist;
wr(c, &f);
return;
}
}
}
/* if(fp == nil) fprint(2, "fid not found for %d\n", f.fid); */
switch(f.type){
case Twalk:
if(Debug){
fprint(2, "Twalk %d %d", f.fid, f.newfid);
for(i = 0; i < f.nwname; i++)
fprint(2, " %s", f.wname[i]);
fprint(2, "\n");
}
nfp = findfid(c, f.newfid);
f.type = Rerror;
if(nfp){
deletefid(c, nfp);
nfp = nil;
}
if(nfp){
f.ename = "fid in use";
if(Debug) fprint(2, "walk: %s\n", f.ename);
wr(c, &f);
break;
}else if(fp->open){
f.ename = "can't clone";
wr(c, &f);
break;
}
if(f.newfid != f.fid)
nfp = fidclone(fp, f.newfid);
else
nfp = fp;
if((wq = devwalk(c, file, fp, nfp, f.wname, f.nwname, &f.ename)) == nil){
if(nfp != fp)
deletefid(c, nfp);
f.type = Rerror;
}else{
if(nfp != fp){
if(wq->nqid != f.nwname)
deletefid(c, nfp);
}
f.type = Rwalk;
f.nwqid = wq->nqid;
for(i = 0; i < wq->nqid; i++)
f.wqid[i] = wq->qid[i];
styxfree(wq);
}
wr(c, &f);
break;
case Topen:
if(Debug)
fprint(2, "Topen %d\n", f.fid);
f.ename = nil;
if(fp->open)
f.ename = Eopen;
else if((fp->qid.type&QTDIR) && (f.mode&(OWRITE|OTRUNC|ORCLOSE)))
f.ename = Eperm;
else if(file != nil && !styxperm(file, c->uname, f.mode))
f.ename = Eperm;
else if((f.mode&ORCLOSE) && file != nil && file->parent != nil && !styxperm(file->parent, c->uname, OWRITE))
f.ename = Eperm;
if(f.ename != nil){
f.type = Rerror;
wr(c, &f);
break;
}
f.ename = Enonexist;
decreff(fp);
if(ops->open == nil || (f.ename = ops->open(&fp->qid, f.mode)) == nil){
f.type = Ropen;
f.qid = fp->qid;
fp->mode = f.mode;
fp->open = 1;
fp->offset = 0;
incopen(fp);
}
else
f.type = Rerror;
increff(fp);
wr(c, &f);
break;
case Tcreate:
if(Debug)
fprint(2, "Tcreate %d %s\n", f.fid, f.name);
f.ename = nil;
if(fp->open)
f.ename = Eopen;
else if(!(fp->qid.type&QTDIR))
f.ename = Enotdir;
else if((f.perm&DMDIR) && (f.mode&(OWRITE|OTRUNC|ORCLOSE)))
f.ename = Eperm;
else if(file != nil && !styxperm(file, c->uname, OWRITE))
f.ename = Eperm;
if(f.ename != nil){
f.type = Rerror;
wr(c, &f);
break;
}
f.ename = Eperm;
decreff(fp);
if(file != nil){
if(f.perm&DMDIR)
f.perm = (f.perm&~0777) | (file->d.mode&f.perm&0777) | DMDIR;
else
f.perm = (f.perm&(~0777|0111)) | (file->d.mode&f.perm&0666);
}
if(ops->create && (f.ename = ops->create(&fp->qid, f.name, f.perm, f.mode)) == nil){
f.type = Rcreate;
f.qid = fp->qid;
fp->mode = f.mode;
fp->open = 1;
fp->offset = 0;
incopen(fp);
}
else
f.type = Rerror;
increff(fp);
wr(c, &f);
break;
case Tread:
if(Debug)
fprint(2, "Tread %d\n", f.fid);
if(!fp->open){
f.type = Rerror;
f.ename = Ebadfid;
wr(c, &f);
break;
}
if(fp->qid.type&QTDIR || (file != nil && file->d.qid.type&QTDIR)){
f.type = Rread;
if(file == nil){
f.ename = Eperm;
if(ops->read && (f.ename = ops->read(fp->qid, c->data, (ulong*)(&f.count), fp->dri)) == nil){
f.data = c->data;
}
else
f.type = Rerror;
}
else{
f.count = devdirread(fp, file, c->data, f.count);
f.data = c->data;
}
}else{
f.ename = Eperm;
f.type = Rerror;
if(ops->read && (f.ename = ops->read(fp->qid, c->data, (ulong*)(&f.count), f.offset)) == nil){
f.type = Rread;
f.data = c->data;
}
}
wr(c, &f);
break;
case Twrite:
if(Debug)
fprint(2, "Twrite %d\n", f.fid);
if(!fp->open){
f.type = Rerror;
f.ename = Ebadfid;
wr(c, &f);
break;
}
f.ename = Eperm;
f.type = Rerror;
if(ops->write && (f.ename = ops->write(fp->qid, f.data, (ulong*)(&f.count), f.offset)) == nil){
f.type = Rwrite;
}
wr(c, &f);
break;
case Tclunk:
if(Debug)
fprint(2, "Tclunk %d\n", f.fid);
open = fp->open;
mode = fp->mode;
qid = fp->qid;
deletefid(c, fp);
f.type = Rclunk;
if(open && ops->close && (f.ename = ops->close(qid, mode)) != nil)
f.type = Rerror;
wr(c, &f);
break;
case Tremove:
if(Debug)
fprint(2, "Tremove %d\n", f.fid);
if(file != nil && file->parent != nil && !styxperm(file->parent, c->uname, OWRITE)){
f.type = Rerror;
f.ename = Eperm;
deletefid(c, fp);
wr(c, &f);
break;
}
f.ename = Eperm;
if(ops->remove && (f.ename = ops->remove(fp->qid)) == nil)
f.type = Rremove;
else
f.type = Rerror;
deletefid(c, fp);
wr(c, &f);
break;
case Tstat:
if(Debug)
fprint(2, "Tstat %d qid=%llx\n", f.fid, fp->qid.path);
f.stat = styxmalloc(MAXSTAT);
f.ename = "stat error";
if(ops->stat == nil && file != nil){
f.type = Rstat;
f.nstat = convD2M(&file->d, f.stat, MAXSTAT);
}
else if(ops->stat && (f.ename = ops->stat(fp->qid, &dir)) == nil){
f.type = Rstat;
f.nstat = convD2M(&dir, f.stat, MAXSTAT);
}
else
f.type = Rerror;
wr(c, &f);
styxfree(f.stat);
break;
case Twstat:
if(Debug)
fprint(2, "Twstat %d\n", f.fid);
f.ename = Eperm;
convM2D(f.stat, f.nstat, &dir, strs);
dir.name = nilconv(dir.name);
dir.uid = nilconv(dir.uid);
dir.gid = nilconv(dir.gid);
dir.muid = nilconv(dir.muid);
if(ops->wstat && (f.ename = ops->wstat(fp->qid, &dir)) == nil)
f.type = Rwstat;
else
f.type = Rerror;
wr(c, &f);
break;
case Tversion:
if(Debug)
fprint(2, "Tversion\n");
f.type = Rversion;
f.tag = NOTAG;
wr(c, &f);
break;
case Tauth:
if(Debug)
fprint(2, "Tauth\n");
f.type = Rauth;
wr(c, &f);
break;
case Tattach:
if(Debug)
fprint(2, "Tattach %d %s %s\n", f.fid, f.uname[0] ? f.uname : c->uname, f.aname[0]? f.aname: c->aname);
if(fp){
f.type = Rerror;
f.ename = "fid in use";
}else{
Qid q;
if(f.uname[0]){
free(c->uname);
c->uname = strdup(f.uname);
}
if(f.aname[0]){
free(c->aname);
c->aname = strdup(f.aname);
}
q.path = Qroot;
q.type = QTDIR;
q.vers = 0;
fp = newfid(c, f.fid, q);
f.type = Rattach;
f.fid = fp->fid;
f.qid = q;
if(ops->attach && (f.ename = ops->attach(c->uname, c->aname)) != nil)
f.type = Rerror;
}
wr(c, &f);
break;
}
}
char *
styxinit(Styxserver *server, Styxops *ops, char *port, int perm, int needfile)
{
int i;
if(Debug)
fprint(2, "Initialising Styx server on port %s\n", port);
if(perm == -1)
perm = 0555;
server->ops = ops;
server->clients = nil;
server->root = nil;
server->ftab = (Styxfile**)malloc(TABSZ*sizeof(Styxfile*));
for(i = 0; i < TABSZ; i++)
server->ftab[i] = nil;
server->qidgen = Qroot+1;
if(styxinitsocket() < 0)
return "styxinitsocket failed";
server->connfd = styxannounce(server, port);
if(server->connfd < 0)
return "can't announce on network port";
styxinitwait(server);
server->root = newfile(server, nil, 1, Qroot, "/", perm|DMDIR, eve);
server->needfile = needfile;
return nil;
}
char*
styxend(Styxserver *server)
{
USED(server);
styxendsocket();
return nil;
}
char *
styxwait(Styxserver *server)
{
return styxwaitmsg(server);
}
char *
styxprocess(Styxserver *server)
{
Client *c;
int s;
if(styxnewcall(server)){
s = styxaccept(server);
if(s >= 0){
newclient(server, s);
styxnewclient(server, s);
}
}
for(c = server->clients; c != nil; ){
Client *next = c->next;
server->curc = c;
if(c->fd >= 0 && styxnewmsg(server, c->fd))
c->state |= CRECV;
if(c->state&(CNREAD|CRECV)){
if(c->state&CDISC){
styxfreeclient(server, c->fd);
freeclient(c);
}else
do
run(c);
while(c->state&CNREAD);
}
c = next;
}
return nil;
}
Client*
styxclient(Styxserver *server)
{
return server->curc;
}
Styxfile*
styxaddfile(Styxserver *server, Path pqid, Path qid, char *name, int mode, char *owner)
{
Styxfile *f, *parent;
parent = styxfindfile(server, pqid);
if(parent == nil || (parent->d.qid.type&QTDIR) == 0)
return nil;
f = newfile(server, parent, 0, qid, name, mode, owner);
return f;
}
Styxfile*
styxadddir(Styxserver *server, Path pqid, Path qid, char *name, int mode, char *owner)
{
Styxfile *f, *parent;
parent = styxfindfile(server, pqid);
if(parent == nil || (parent->d.qid.type&QTDIR) == 0)
return nil;
f = newfile(server, parent, 1, qid, name, mode|DMDIR, owner);
return f;
}
long
styxreadstr(ulong off, char *buf, ulong n, char *str)
{
int size;
size = strlen(str);
if(off >= size)
return 0;
if(off+n > size)
n = size-off;
memmove(buf, str+off, n);
return n;
}
Qid
styxqid(int path, int isdir)
{
Qid q;
q.path = path;
q.vers = 0;
if(isdir)
q.type = QTDIR;
else
q.type = 0;
return q;
}
void
styxsetowner(char *name)
{
eve = name;
}