sys/src/lib9p/srv.c

   1 #include <u.h>
   2 #include <libc.h>
   3 #include <auth.h>
   4 #include <fcall.h>
   5 #include <thread.h>
   6 #include <9p.h>
   7
   8 void (*_forker)(void(*)(void*), void*, int);
   9
  10 static char Ebadattach[] = "unknown specifier in attach";
  11 static char Ebadoffset[] = "bad offset";
  12 static char Ebadcount[] = "bad count";
  13 static char Ebotch[] = "9P protocol botch";
  14 static char Ecreatenondir[] = "create in non-directory";
  15 static char Edupfid[] = "duplicate fid";
  16 static char Eduptag[] = "duplicate tag";
  17 static char Eisdir[] = "is a directory";
  18 static char Enocreate[] = "create prohibited";
  19 static char Enomem[] = "out of memory";
  20 static char Enoremove[] = "remove prohibited";
  21 static char Enostat[] = "stat prohibited";
  22 static char Enotfound[] = "file not found";
  23 static char Enowrite[] = "write prohibited";
  24 static char Enowstat[] = "wstat prohibited";
  25 static char Eperm[] = "permission denied";
  26 static char Eunknownfid[] = "unknown fid";
  27 static char Ebaddir[] = "bad directory in wstat";
  28 static char Ewalknodir[] = "walk in non-directory";
  29
  30 static void
  31 setfcallerror(Fcall *f, char *err)
  32 {
  33         f->ename = err;
  34         f->type = Rerror;
  35 }
  36
  37 static void
  38 changemsize(Srv *srv, int msize)
  39 {
  40         if(srv->rbuf && srv->wbuf && srv->msize == msize)
  41                 return;
  42         qlock(&srv->rlock);
  43         qlock(&srv->wlock);
  44         srv->msize = msize;
  45         free(srv->rbuf);
  46         free(srv->wbuf);
  47         srv->rbuf = emalloc9p(msize);
  48         srv->wbuf = emalloc9p(msize);
  49         qunlock(&srv->rlock);
  50         qunlock(&srv->wlock);
  51 }
  52
  53 static Req*
  54 getreq(Srv *s)
  55 {
  56         long n;
  57         uchar *buf;
  58         Fcall f;
  59         Req *r;
  60
  61         qlock(&s->rlock);
  62         while((n = read9pmsg(s->infd, s->rbuf, s->msize)) == 0)
  63                 ;
  64         if(n < 0){
  65                 qunlock(&s->rlock);
  66                 return nil;
  67         }
  68
  69         buf = emalloc9p(n);
  70         memmove(buf, s->rbuf, n);
  71         qunlock(&s->rlock);
  72
  73         if(convM2S(buf, n, &f) != n){
  74                 free(buf);
  75                 return nil;
  76         }
  77
  78         if((r=allocreq(s->rpool, f.tag)) == nil){       /* duplicate tag: cons up a fake Req */
  79                 r = emalloc9p(sizeof *r);
  80                 incref(&r->ref);
  81                 r->tag = f.tag;
  82                 r->ifcall = f;
  83                 r->error = Eduptag;
  84                 r->buf = buf;
  85                 r->responded = 0;
  86                 r->type = 0;
  87                 r->srv = s;
  88                 r->pool = nil;
  89 if(chatty9p)
  90         fprint(2, "<-%d- %F: dup tag\n", s->infd, &f);
  91                 return r;
  92         }
  93
  94         r->srv = s;
  95         r->responded = 0;
  96         r->buf = buf;
  97         r->ifcall = f;
  98         memset(&r->ofcall, 0, sizeof r->ofcall);
  99         r->type = r->ifcall.type;
 100
 101 if(chatty9p)
 102         if(r->error)
 103                 fprint(2, "<-%d- %F: %s\n", s->infd, &r->ifcall, r->error);
 104         else
 105                 fprint(2, "<-%d- %F\n", s->infd, &r->ifcall);
 106
 107         return r;
 108 }
 109
 110 static void
 111 filewalk(Req *r)
 112 {
 113         int i;
 114         File *f;
 115
 116         f = r->fid->file;
 117         assert(f != nil);
 118
 119         incref(f);
 120         for(i=0; i<r->ifcall.nwname; i++)
 121                 if(f = walkfile(f, r->ifcall.wname[i]))
 122                         r->ofcall.wqid[i] = f->qid;
 123                 else
 124                         break;
 125
 126         r->ofcall.nwqid = i;
 127         if(f){
 128                 r->newfid->file = f;
 129                 r->newfid->qid = r->newfid->file->qid;
 130         }
 131         respond(r, nil);
 132 }
 133
 134 void
 135 walkandclone(Req *r, char *(*walk1)(Fid*, char*, void*), char *(*clone)(Fid*, Fid*, void*), void *arg)
 136 {
 137         int i;
 138         char *e;
 139
 140         if(r->fid == r->newfid && r->ifcall.nwname > 1){
 141                 respond(r, "lib9p: unused documented feature not implemented");
 142                 return;
 143         }
 144
 145         if(r->fid != r->newfid){
 146                 r->newfid->qid = r->fid->qid;
 147                 if(clone && (e = clone(r->fid, r->newfid, arg))){
 148                         respond(r, e);
 149                         return;
 150                 }
 151         }
 152
 153         e = nil;
 154         for(i=0; i<r->ifcall.nwname; i++){
 155                 if(e = walk1(r->newfid, r->ifcall.wname[i], arg))
 156                         break;
 157                 r->ofcall.wqid[i] = r->newfid->qid;
 158         }
 159
 160         r->ofcall.nwqid = i;
 161         if(e && i==0)
 162                 respond(r, e);
 163         else
 164                 respond(r, nil);
 165 }
 166
 167 static void
 168 sversion(Srv *srv, Req *r)
 169 {
 170         if(srv->rref.ref != 2){
 171                 respond(r, Ebotch);
 172                 return;
 173         }
 174         if(strncmp(r->ifcall.version, "9P", 2) != 0){
 175                 r->ofcall.version = "unknown";
 176                 respond(r, nil);
 177                 return;
 178         }
 179         r->ofcall.version = "9P2000";
 180         if(r->ifcall.msize < 256){
 181                 respond(r, "version: message size too small");
 182                 return;
 183         }
 184         if(r->ifcall.msize < 1024*1024)
 185                 r->ofcall.msize = r->ifcall.msize;
 186         else
 187                 r->ofcall.msize = 1024*1024;
 188         respond(r, nil);
 189 }
 190
 191 static void
 192 rversion(Req *r, char *error)
 193 {
 194         if(error == nil)
 195                 changemsize(r->srv, r->ofcall.msize);
 196 }
 197
 198 static void
 199 sauth(Srv *srv, Req *r)
 200 {
 201         char e[ERRMAX];
 202
 203         if((r->afid = allocfid(srv->fpool, r->ifcall.afid)) == nil){
 204                 respond(r, Edupfid);
 205                 return;
 206         }
 207         if(srv->auth)
 208                 srv->auth(r);
 209         else{
 210                 snprint(e, sizeof e, "%s: authentication not required", argv0);
 211                 respond(r, e);
 212         }
 213 }
 214 static void
 215 rauth(Req *r, char *error)
 216 {
 217         if(error && r->afid)
 218                 closefid(removefid(r->srv->fpool, r->afid->fid));
 219 }
 220
 221 static void
 222 sattach(Srv *srv, Req *r)
 223 {
 224         if((r->fid = allocfid(srv->fpool, r->ifcall.fid)) == nil){
 225                 respond(r, Edupfid);
 226                 return;
 227         }
 228         r->afid = nil;
 229         if(r->ifcall.afid != NOFID && (r->afid = lookupfid(srv->fpool, r->ifcall.afid)) == nil){
 230                 respond(r, Eunknownfid);
 231                 return;
 232         }
 233         r->fid->uid = estrdup9p(r->ifcall.uname);
 234         if(srv->tree){
 235                 r->fid->file = srv->tree->root;
 236                 incref(r->fid->file);
 237                 r->ofcall.qid = r->fid->file->qid;
 238                 r->fid->qid = r->ofcall.qid;
 239         }
 240         if(srv->attach)
 241                 srv->attach(r);
 242         else
 243                 respond(r, nil);
 244         return;
 245 }
 246 static void
 247 rattach(Req *r, char *error)
 248 {
 249         if(error && r->fid)
 250                 closefid(removefid(r->srv->fpool, r->fid->fid));
 251 }
 252
 253 static void
 254 sflush(Srv *srv, Req *r)
 255 {
 256         r->oldreq = lookupreq(srv->rpool, r->ifcall.oldtag);
 257         if(r->oldreq == nil || r->oldreq == r)
 258                 respond(r, nil);
 259         else if(srv->flush)
 260                 srv->flush(r);
 261         else
 262                 respond(r, nil);
 263 }
 264 static int
 265 rflush(Req *r, char *error)
 266 {
 267         Req *or;
 268
 269         assert(error == nil);
 270         or = r->oldreq;
 271         if(or){
 272                 qlock(&or->lk);
 273                 if(or->responded == 0){
 274                         or->flush = erealloc9p(or->flush, (or->nflush+1)*sizeof(or->flush[0]));
 275                         or->flush[or->nflush++] = r;
 276                         qunlock(&or->lk);
 277                         return -1;              /* delay response until or is responded */
 278                 }
 279                 qunlock(&or->lk);
 280                 closereq(or);
 281         }
 282         r->oldreq = nil;
 283         return 0;
 284 }
 285
 286 static char*
 287 oldwalk1(Fid *fid, char *name, void *arg)
 288 {
 289         char *e;
 290         Qid qid;
 291         Srv *srv;
 292
 293         srv = arg;
 294         e = srv->walk1(fid, name, &qid);
 295         if(e)
 296                 return e;
 297         fid->qid = qid;
 298         return nil;
 299 }
 300
 301 static char*
 302 oldclone(Fid *fid, Fid *newfid, void *arg)
 303 {
 304         Srv *srv;
 305
 306         srv = arg;
 307         if(srv->clone == nil)
 308                 return nil;
 309         return srv->clone(fid, newfid);
 310 }
 311
 312 static void
 313 swalk(Srv *srv, Req *r)
 314 {
 315         if((r->fid = lookupfid(srv->fpool, r->ifcall.fid)) == nil){
 316                 respond(r, Eunknownfid);
 317                 return;
 318         }
 319         if(r->fid->omode != -1){
 320                 respond(r, "cannot clone open fid");
 321                 return;
 322         }
 323         if(r->ifcall.nwname && !(r->fid->qid.type&QTDIR)){
 324                 respond(r, Ewalknodir);
 325                 return;
 326         }
 327         if(r->ifcall.fid != r->ifcall.newfid){
 328                 if((r->newfid = allocfid(srv->fpool, r->ifcall.newfid)) == nil){
 329                         respond(r, Edupfid);
 330                         return;
 331                 }
 332                 r->newfid->uid = estrdup9p(r->fid->uid);
 333         }else{
 334                 incref(&r->fid->ref);
 335                 r->newfid = r->fid;
 336         }
 337         if(r->fid->file){
 338                 filewalk(r);
 339         }else if(srv->walk1)
 340                 walkandclone(r, oldwalk1, oldclone, srv);
 341         else if(srv->walk)
 342                 srv->walk(r);
 343         else
 344                 sysfatal("no walk function, no file trees");
 345 }
 346 static void
 347 rwalk(Req *r, char *error)
 348 {
 349         if(error || r->ofcall.nwqid < r->ifcall.nwname){
 350                 if(r->ifcall.fid != r->ifcall.newfid && r->newfid)
 351                         closefid(removefid(r->srv->fpool, r->newfid->fid));
 352                 if (r->ofcall.nwqid==0){
 353                         if(error==nil && r->ifcall.nwname!=0)
 354                                 r->error = Enotfound;
 355                 }else
 356                         r->error = nil; // No error on partial walks
 357         }else{
 358                 if(r->ofcall.nwqid == 0){
 359                         /* Just a clone */
 360                         r->newfid->qid = r->fid->qid;
 361                 }else{
 362                         /* if file trees are in use, filewalk took care of the rest */
 363                         r->newfid->qid = r->ofcall.wqid[r->ofcall.nwqid-1];
 364                 }
 365         }
 366 }
 367
 368 static void
 369 sopen(Srv *srv, Req *r)
 370 {
 371         int p;
 372
 373         if((r->fid = lookupfid(srv->fpool, r->ifcall.fid)) == nil){
 374                 respond(r, Eunknownfid);
 375                 return;
 376         }
 377         if(r->fid->omode != -1){
 378                 respond(r, Ebotch);
 379                 return;
 380         }
 381         if((r->fid->qid.type&QTDIR) && (r->ifcall.mode&~ORCLOSE) != OREAD){
 382                 respond(r, Eisdir);
 383                 return;
 384         }
 385         r->ofcall.qid = r->fid->qid;
 386         switch(r->ifcall.mode&3){
 387         default:
 388                 assert(0);
 389         case OREAD:
 390                 p = AREAD;
 391                 break;
 392         case OWRITE:
 393                 p = AWRITE;
 394                 break;
 395         case ORDWR:
 396                 p = AREAD|AWRITE;
 397                 break;
 398         case OEXEC:
 399                 p = AEXEC;
 400                 break;
 401         }
 402         if(r->ifcall.mode&OTRUNC)
 403                 p |= AWRITE;
 404         if((r->fid->qid.type&QTDIR) && p!=AREAD){
 405                 respond(r, Eperm);
 406                 return;
 407         }
 408         if(r->fid->file){
 409                 if(!hasperm(r->fid->file, r->fid->uid, p)){
 410                         respond(r, Eperm);
 411                         return;
 412                 }
 413         /* BUG RACE */
 414                 if((r->ifcall.mode&ORCLOSE)
 415                 && !hasperm(r->fid->file->parent, r->fid->uid, AWRITE)){
 416                         respond(r, Eperm);
 417                         return;
 418                 }
 419                 r->ofcall.qid = r->fid->file->qid;
 420                 if((r->ofcall.qid.type&QTDIR)
 421                 && (r->fid->rdir = opendirfile(r->fid->file)) == nil){
 422                         respond(r, "opendirfile failed");
 423                         return;
 424                 }
 425         }
 426         if(srv->open)
 427                 srv->open(r);
 428         else
 429                 respond(r, nil);
 430 }
 431 static void
 432 ropen(Req *r, char *error)
 433 {
 434         char errbuf[ERRMAX];
 435         if(error)
 436                 return;
 437         if(chatty9p){
 438                 snprint(errbuf, sizeof errbuf, "fid mode is 0x%ux\n", r->ifcall.mode);
 439                 write(2, errbuf, strlen(errbuf));
 440         }
 441         r->fid->omode = r->ifcall.mode;
 442         r->fid->qid = r->ofcall.qid;
 443         if(r->ofcall.qid.type&QTDIR)
 444                 r->fid->diroffset = 0;
 445 }
 446
 447 static void
 448 screate(Srv *srv, Req *r)
 449 {
 450         if((r->fid = lookupfid(srv->fpool, r->ifcall.fid)) == nil)
 451                 respond(r, Eunknownfid);
 452         else if(r->fid->omode != -1)
 453                 respond(r, Ebotch);
 454         else if(!(r->fid->qid.type&QTDIR))
 455                 respond(r, Ecreatenondir);
 456         else if(r->fid->file && !hasperm(r->fid->file, r->fid->uid, AWRITE))
 457                 respond(r, Eperm);
 458         else if(srv->create)
 459                 srv->create(r);
 460         else
 461                 respond(r, Enocreate);
 462 }
 463 static void
 464 rcreate(Req *r, char *error)
 465 {
 466         if(error)
 467                 return;
 468         r->fid->omode = r->ifcall.mode;
 469         r->fid->qid = r->ofcall.qid;
 470 }
 471
 472 static void
 473 sread(Srv *srv, Req *r)
 474 {
 475         int o;
 476
 477         if((r->fid = lookupfid(srv->fpool, r->ifcall.fid)) == nil){
 478                 respond(r, Eunknownfid);
 479                 return;
 480         }
 481         if((int)r->ifcall.count < 0){
 482                 respond(r, Ebotch);
 483                 return;
 484         }
 485         if(r->ifcall.offset < 0
 486         || ((r->fid->qid.type&QTDIR) && r->ifcall.offset != 0 && r->ifcall.offset != r->fid->diroffset)){
 487                 respond(r, Ebadoffset);
 488                 return;
 489         }
 490
 491         if(r->ifcall.count > srv->msize - IOHDRSZ)
 492                 r->ifcall.count = srv->msize - IOHDRSZ;
 493         r->rbuf = emalloc9p(r->ifcall.count);
 494         r->ofcall.data = r->rbuf;
 495         o = r->fid->omode & 3;
 496         if(o != OREAD && o != ORDWR && o != OEXEC){
 497                 respond(r, Ebotch);
 498                 return;
 499         }
 500         if((r->fid->qid.type&QTDIR) && r->fid->file){
 501                 r->ofcall.count = readdirfile(r->fid->rdir, r->rbuf, r->ifcall.count);
 502                 respond(r, nil);
 503                 return;
 504         }
 505         if(srv->read)
 506                 srv->read(r);
 507         else
 508                 respond(r, "no srv->read");
 509 }
 510 static void
 511 rread(Req *r, char *error)
 512 {
 513         if(error==nil && (r->fid->qid.type&QTDIR))
 514                 r->fid->diroffset += r->ofcall.count;
 515 }
 516
 517 static void
 518 swrite(Srv *srv, Req *r)
 519 {
 520         int o;
 521         char e[ERRMAX];
 522
 523         if((r->fid = lookupfid(srv->fpool, r->ifcall.fid)) == nil){
 524                 respond(r, Eunknownfid);
 525                 return;
 526         }
 527         if((int)r->ifcall.count < 0){
 528                 respond(r, Ebotch);
 529                 return;
 530         }
 531         if(r->ifcall.offset < 0){
 532                 respond(r, Ebotch);
 533                 return;
 534         }
 535         if(r->ifcall.count > srv->msize - IOHDRSZ)
 536                 r->ifcall.count = srv->msize - IOHDRSZ;
 537         o = r->fid->omode & 3;
 538         if(o != OWRITE && o != ORDWR){
 539                 snprint(e, sizeof e, "write on fid with open mode 0x%ux", r->fid->omode);
 540                 respond(r, e);
 541                 return;
 542         }
 543         if(srv->write)
 544                 srv->write(r);
 545         else
 546                 respond(r, "no srv->write");
 547 }
 548 static void
 549 rwrite(Req *r, char *error)
 550 {
 551         if(error)
 552                 return;
 553         if(r->fid->file)
 554                 r->fid->file->qid.vers++;
 555 }
 556
 557 static void
 558 sclunk(Srv *srv, Req *r)
 559 {
 560         if((r->fid = removefid(srv->fpool, r->ifcall.fid)) == nil)
 561                 respond(r, Eunknownfid);
 562         else
 563                 respond(r, nil);
 564 }
 565 static void
 566 rclunk(Req*, char*)
 567 {
 568 }
 569
 570 static void
 571 sremove(Srv *srv, Req *r)
 572 {
 573         if((r->fid = removefid(srv->fpool, r->ifcall.fid)) == nil){
 574                 respond(r, Eunknownfid);
 575                 return;
 576         }
 577         /* BUG RACE */
 578         if(r->fid->file && !hasperm(r->fid->file->parent, r->fid->uid, AWRITE)){
 579                 respond(r, Eperm);
 580                 return;
 581         }
 582         if(srv->remove)
 583                 srv->remove(r);
 584         else
 585                 respond(r, r->fid->file ? nil : Enoremove);
 586 }
 587 static void
 588 rremove(Req *r, char *error, char *errbuf)
 589 {
 590         if(error)
 591                 return;
 592         if(r->fid->file){
 593                 if(removefile(r->fid->file) < 0){
 594                         snprint(errbuf, ERRMAX, "remove %s: %r",
 595                                 r->fid->file->name);
 596                         r->error = errbuf;
 597                 }
 598                 r->fid->file = nil;
 599         }
 600 }
 601
 602 static void
 603 sstat(Srv *srv, Req *r)
 604 {
 605         if((r->fid = lookupfid(srv->fpool, r->ifcall.fid)) == nil){
 606                 respond(r, Eunknownfid);
 607                 return;
 608         }
 609         if(r->fid->file){
 610                 /* should we rlock the file? */
 611                 r->d = r->fid->file->Dir;
 612                 if(r->d.name)
 613                         r->d.name = estrdup9p(r->d.name);
 614                 if(r->d.uid)
 615                         r->d.uid = estrdup9p(r->d.uid);
 616                 if(r->d.gid)
 617                         r->d.gid = estrdup9p(r->d.gid);
 618                 if(r->d.muid)
 619                         r->d.muid = estrdup9p(r->d.muid);
 620         }
 621         if(srv->stat)
 622                 srv->stat(r);
 623         else if(r->fid->file)
 624                 respond(r, nil);
 625         else
 626                 respond(r, Enostat);
 627 }
 628 static void
 629 rstat(Req *r, char *error)
 630 {
 631         int n;
 632         uchar *statbuf;
 633         uchar tmp[BIT16SZ];
 634
 635         if(error)
 636                 return;
 637         if(convD2M(&r->d, tmp, BIT16SZ) != BIT16SZ){
 638                 r->error = "convD2M(_,_,BIT16SZ) did not return BIT16SZ";
 639                 return;
 640         }
 641         n = GBIT16(tmp)+BIT16SZ;
 642         statbuf = emalloc9p(n);
 643         if(statbuf == nil){
 644                 r->error = "out of memory";
 645                 return;
 646         }
 647         r->ofcall.nstat = convD2M(&r->d, statbuf, n);
 648         r->ofcall.stat = statbuf;       /* freed in closereq */
 649         if(r->ofcall.nstat <= BIT16SZ){
 650                 r->error = "convD2M fails";
 651                 free(statbuf);
 652                 return;
 653         }
 654 }
 655
 656 static void
 657 swstat(Srv *srv, Req *r)
 658 {
 659         if((r->fid = lookupfid(srv->fpool, r->ifcall.fid)) == nil){
 660                 respond(r, Eunknownfid);
 661                 return;
 662         }
 663         if(srv->wstat == nil){
 664                 respond(r, Enowstat);
 665                 return;
 666         }
 667         if(convM2D(r->ifcall.stat, r->ifcall.nstat, &r->d, (char*)r->ifcall.stat) != r->ifcall.nstat){
 668                 respond(r, Ebaddir);
 669                 return;
 670         }
 671         if((ushort)~r->d.type){
 672                 respond(r, "wstat -- attempt to change type");
 673                 return;
 674         }
 675         if((uint)~r->d.dev){
 676                 respond(r, "wstat -- attempt to change dev");
 677                 return;
 678         }
 679         if((uchar)~r->d.qid.type || (ulong)~r->d.qid.vers || (uvlong)~r->d.qid.path){
 680                 respond(r, "wstat -- attempt to change qid");
 681                 return;
 682         }
 683         if(r->d.muid && r->d.muid[0]){
 684                 respond(r, "wstat -- attempt to change muid");
 685                 return;
 686         }
 687         if((ulong)~r->d.mode && ((r->d.mode&DMDIR)>>24) != (r->fid->qid.type&QTDIR)){
 688                 respond(r, "wstat -- attempt to change DMDIR bit");
 689                 return;
 690         }
 691         srv->wstat(r);
 692 }
 693 static void
 694 rwstat(Req*, char*)
 695 {
 696 }
 697
 698 static void srvclose(Srv *);
 699
 700 static void
 701 srvwork(void *v)
 702 {
 703         Srv *srv = v;
 704         Req *r;
 705
 706         incref(&srv->rref);
 707         incref(&srv->sref);
 708         while(r = getreq(srv)){
 709                 incref(&srv->rref);
 710                 if(r->error){
 711                         respond(r, r->error);
 712                         continue;
 713                 }
 714                 qlock(&srv->slock);
 715                 switch(r->ifcall.type){
 716                 default:
 717                         respond(r, "unknown message");
 718                         break;
 719                 case Tversion:  sversion(srv, r);       break;
 720                 case Tauth:     sauth(srv, r);  break;
 721                 case Tattach:   sattach(srv, r);        break;
 722                 case Tflush:    sflush(srv, r); break;
 723                 case Twalk:     swalk(srv, r);  break;
 724                 case Topen:     sopen(srv, r);  break;
 725                 case Tcreate:   screate(srv, r);        break;
 726                 case Tread:     sread(srv, r);  break;
 727                 case Twrite:    swrite(srv, r); break;
 728                 case Tclunk:    sclunk(srv, r); break;
 729                 case Tremove:   sremove(srv, r);        break;
 730                 case Tstat:     sstat(srv, r);  break;
 731                 case Twstat:    swstat(srv, r); break;
 732                 }
 733                 qunlock(&srv->slock);
 734         }
 735         decref(&srv->sref);
 736         srvclose(srv);
 737 }
 738
 739 static void
 740 srvclose(Srv *srv)
 741 {
 742         if(decref(&srv->rref))
 743                 return;
 744
 745         if(chatty9p)
 746                 fprint(2, "srvclose\n");
 747
 748         free(srv->rbuf);
 749         srv->rbuf = nil;
 750         free(srv->wbuf);
 751         srv->wbuf = nil;
 752         srv->msize = 0;
 753         freefidpool(srv->fpool);
 754         srv->fpool = nil;
 755         freereqpool(srv->rpool);
 756         srv->rpool = nil;
 757
 758         if(srv->end)
 759                 srv->end(srv);
 760 }
 761
 762 void
 763 srvacquire(Srv *srv)
 764 {
 765         incref(&srv->sref);
 766         qlock(&srv->slock);
 767 }
 768
 769 void
 770 srvrelease(Srv *srv)
 771 {
 772         if(decref(&srv->sref) == 0)
 773                 _forker(srvwork, srv, 0);
 774         qunlock(&srv->slock);
 775 }
 776
 777 void
 778 srv(Srv *srv)
 779 {
 780         fmtinstall('D', dirfmt);
 781         fmtinstall('F', fcallfmt);
 782
 783         srv->sref.ref = 0;
 784         srv->rref.ref = 0;
 785
 786         if(srv->fpool == nil)
 787                 srv->fpool = allocfidpool(srv->destroyfid);
 788         if(srv->rpool == nil)
 789                 srv->rpool = allocreqpool(srv->destroyreq);
 790         if(srv->msize == 0)
 791                 srv->msize = 8192+IOHDRSZ;
 792
 793         changemsize(srv, srv->msize);
 794
 795         srv->fpool->srv = srv;
 796         srv->rpool->srv = srv;
 797
 798         if(srv->start)
 799                 srv->start(srv);
 800
 801         srvwork(srv);
 802 }
 803
 804 void
 805 respond(Req *r, char *error)
 806 {
 807         int i, m, n;
 808         char errbuf[ERRMAX];
 809         Srv *srv;
 810
 811         srv = r->srv;
 812         assert(srv != nil);
 813
 814         assert(r->responded == 0);
 815         r->error = error;
 816
 817         switch(r->ifcall.type){
 818         /*
 819          * Flush is special.  If the handler says so, we return
 820          * without further processing.  Respond will be called
 821          * again once it is safe.
 822          */
 823         case Tflush:
 824                 if(rflush(r, error)<0)
 825                         return;
 826                 break;
 827         case Tversion:  rversion(r, error);     break;
 828         case Tauth:     rauth(r, error);        break;
 829         case Tattach:   rattach(r, error);      break;
 830         case Twalk:     rwalk(r, error);        break;
 831         case Topen:     ropen(r, error);        break;
 832         case Tcreate:   rcreate(r, error);      break;
 833         case Tread:     rread(r, error);        break;
 834         case Twrite:    rwrite(r, error);       break;
 835         case Tclunk:    rclunk(r, error);       break;
 836         case Tremove:   rremove(r, error, errbuf);      break;
 837         case Tstat:     rstat(r, error);        break;
 838         case Twstat:    rwstat(r, error);       break;
 839         }
 840
 841         r->ofcall.tag = r->ifcall.tag;
 842         r->ofcall.type = r->ifcall.type+1;
 843         if(r->error)
 844                 setfcallerror(&r->ofcall, r->error);
 845
 846 if(chatty9p)
 847         fprint(2, "-%d-> %F\n", srv->outfd, &r->ofcall);
 848
 849         qlock(&srv->wlock);
 850         n = convS2M(&r->ofcall, srv->wbuf, srv->msize);
 851         if(n <= 0){
 852                 fprint(2, "msize = %d n = %d %F\n", srv->msize, n, &r->ofcall);
 853                 abort();
 854         }
 855         assert(n > 2);
 856         if(r->pool)     /* not a fake */
 857                 closereq(removereq(r->pool, r->ifcall.tag));
 858         m = write(srv->outfd, srv->wbuf, n);
 859         if(m != n)
 860                 fprint(2, "lib9p srv: write %d returned %d on fd %d: %r", n, m, srv->outfd);
 861         qunlock(&srv->wlock);
 862
 863         qlock(&r->lk);  /* no one will add flushes now */
 864         r->responded = 1;
 865         qunlock(&r->lk);
 866
 867         for(i=0; i<r->nflush; i++)
 868                 respond(r->flush[i], nil);
 869         free(r->flush);
 870         r->flush = nil;
 871         r->nflush = 0;
 872
 873         if(r->pool)
 874                 closereq(r);
 875         else
 876                 free(r);
 877
 878         srvclose(srv);
 879 }
 880
 881 void
 882 responderror(Req *r)
 883 {
 884         char errbuf[ERRMAX];
 885
 886         rerrstr(errbuf, sizeof errbuf);
 887         respond(r, errbuf);
 888 }
 889
 890 int
 891 postfd(char *name, int pfd)
 892 {
 893         int fd;
 894         char buf[80];
 895
 896         snprint(buf, sizeof buf, "/srv/%s", name);
 897         if(chatty9p)
 898                 fprint(2, "postfd %s\n", buf);
 899         fd = create(buf, OWRITE|ORCLOSE|OCEXEC, 0600);
 900         if(fd < 0){
 901                 if(chatty9p)
 902                         fprint(2, "create fails: %r\n");
 903                 return -1;
 904         }
 905         if(fprint(fd, "%d", pfd) < 0){
 906                 if(chatty9p)
 907                         fprint(2, "write fails: %r\n");
 908                 close(fd);
 909                 return -1;
 910         }
 911         if(chatty9p)
 912                 fprint(2, "postfd successful\n");
 913         return 0;
 914 }
 915
 916 int
 917 sharefd(char *name, char *desc, int pfd)
 918 {
 919         int fd;
 920         char buf[80];
 921
 922         snprint(buf, sizeof buf, "#σc/%s", name);
 923         if((fd = create(buf, OREAD, 0700|DMDIR)) >= 0)
 924                 close(fd);
 925         snprint(buf, sizeof buf, "#σc/%s/%s", name, desc);
 926         if(chatty9p)
 927                 fprint(2, "sharefd %s\n", buf);
 928         fd = create(buf, OWRITE, 0600);
 929         if(fd < 0){
 930                 if(chatty9p)
 931                         fprint(2, "create fails: %r\n");
 932                 return -1;
 933         }
 934         if(fprint(fd, "%d\n", pfd) < 0){
 935                 if(chatty9p)
 936                         fprint(2, "write fails: %r\n");
 937                 close(fd);
 938                 return -1;
 939         }
 940         close(fd);
 941         if(chatty9p)
 942                 fprint(2, "sharefd successful\n");
 943         return 0;
 944 }