ref: fb7dd4b3a868cb8987049c95bb32e6425a73c8b9
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; }