sys/src/cmd/ndb/cs.c

   1 #include <u.h>
   2 #include <libc.h>
   3 #include <auth.h>
   4 #include <fcall.h>
   5 #include <bio.h>
   6 #include <ctype.h>
   7 #include <ndb.h>
   8 #include <ip.h>
   9 #include <String.h>
  10
  11 enum
  12 {
  13         Nreply=                 20,
  14         Maxreply=               256,
  15         Maxrequest=             128,
  16         Maxpath=                128,
  17         Maxfdata=               8192,
  18         Maxhost=                64,             /* maximum host name size */
  19         Maxservice=             64,             /* maximum service name size */
  20         Maxactive=              200,            /* maximum number of active slave procs */
  21
  22         Qdir=                   0,
  23         Qcs=                    1,
  24 };
  25
  26 typedef struct Mfile    Mfile;
  27 typedef struct Mlist    Mlist;
  28 typedef struct Network  Network;
  29 typedef struct Flushreq Flushreq;
  30 typedef struct Job      Job;
  31
  32 int vers;               /* incremented each clone/attach */
  33
  34 struct Mfile
  35 {
  36         int             busy;   /* fid in use */
  37         int             ref;    /* cleanup when drops to zero */
  38
  39         char            *user;
  40         Qid             qid;
  41         int             fid;
  42
  43         /*
  44          *  current request
  45          */
  46         char            *net;
  47         char            *host;
  48         char            *serv;
  49         char            *rem;
  50
  51         /*
  52          *  result of the last lookup
  53          */
  54         Network         *nextnet;
  55         int             nreply;
  56         char            *reply[Nreply];
  57         int             replylen[Nreply];
  58 };
  59
  60 struct Mlist
  61 {
  62         Mlist   *next;
  63         Mfile   mf;
  64 };
  65
  66
  67 /*
  68  *  active requests
  69  */
  70 struct Job
  71 {
  72         Job     *next;
  73         int     flushed;
  74         Fcall   request;
  75         Fcall   reply;
  76 };
  77 QLock   joblock;
  78 Job     *joblist;
  79
  80 Mlist   *mlist;
  81 int     mfd[2];
  82 int     debug;
  83 int     paranoia;
  84 int     ipv6lookups = 1;
  85 jmp_buf masterjmp;      /* return through here after a slave process has been created */
  86 int     *isslave;       /* *isslave non-zero means this is a slave process */
  87 long    active;         /* number of active slaves */
  88 char    *dbfile;
  89 Ndb     *db, *netdb;
  90 char    *csuser;
  91
  92 void    rversion(Job*);
  93 void    rflush(Job*);
  94 void    rattach(Job*, Mfile*);
  95 char*   rwalk(Job*, Mfile*);
  96 void    ropen(Job*, Mfile*);
  97 void    rcreate(Job*, Mfile*);
  98 void    rread(Job*, Mfile*);
  99 void    rwrite(Job*, Mfile*);
 100 void    rclunk(Job*, Mfile*);
 101 void    rremove(Job*, Mfile*);
 102 void    rstat(Job*, Mfile*);
 103 void    rwstat(Job*, Mfile*);
 104 void    rauth(Job*);
 105 void    sendmsg(Job*, char*);
 106 void    error(char*);
 107 void    mountinit(char*, char*);
 108 void    io(void);
 109 void    ndbinit(void);
 110 void    netinit(int);
 111 void    netadd(char*);
 112 char    *genquery(Mfile*, char*);
 113 char*   ipinfoquery(Mfile*, char**, int);
 114 int     needproto(Network*, Ndbtuple*);
 115 int     lookup(Mfile*);
 116 Ndbtuple*       reorder(Ndbtuple*, Ndbtuple*);
 117 void    ipid(void);
 118 void    readipinterfaces(void);
 119 void*   emalloc(int);
 120 char*   estrdup(char*);
 121 Job*    newjob(void);
 122 void    freejob(Job*);
 123 void    setext(char*, int, char*);
 124 void    cleanmf(Mfile*);
 125
 126 QLock   dblock;         /* mutex on database operations */
 127 QLock   netlock;        /* mutex for netinit() */
 128
 129 char    *logfile = "cs";
 130 char    *paranoiafile = "cs.paranoia";
 131
 132 char    mntpt[Maxpath];
 133 char    netndb[Maxpath];
 134
 135 /*
 136  *  Network specific translators
 137  */
 138 Ndbtuple*       iplookup(Network*, char*, char*);
 139 char*           iptrans(Ndbtuple*, Network*, char*, char*, int);
 140 Ndbtuple*       telcolookup(Network*, char*, char*);
 141 char*           telcotrans(Ndbtuple*, Network*, char*, char*, int);
 142 Ndbtuple*       dnsiplookup(char*, Ndbs*, int);
 143
 144 struct Network
 145 {
 146         char            *net;
 147         Ndbtuple        *(*lookup)(Network*, char*, char*);
 148         char            *(*trans)(Ndbtuple*, Network*, char*, char*, int);
 149
 150         char            considered;             /* flag: ignored for "net!"? */
 151         char            fasttimeouthack;        /* flag. was for IL */
 152         char            v4only;
 153         char            v6only;
 154
 155         Network         *next;
 156 };
 157
 158 enum {
 159         Ntcp = 1,
 160 };
 161
 162 /*
 163  *  net doesn't apply to (r)udp, icmp(v6), or telco (for speed).
 164  */
 165 Network network[] = {
 166         { "il",         iplookup,       iptrans,        0, 1, 1, 0, },
 167         { "tcp",        iplookup,       iptrans,        0, 0, 0, 0, },
 168         { "il",         iplookup,       iptrans,        0, 0, 1, 0, },
 169         { "udp",        iplookup,       iptrans,        1, 0, 0, 0, },
 170         { "icmp",       iplookup,       iptrans,        1, 0, 1, 0, },
 171         { "icmpv6",     iplookup,       iptrans,        1, 0, 0, 1, },
 172         { "rudp",       iplookup,       iptrans,        1, 0, 1, 0, },
 173         { "ssh",        iplookup,       iptrans,        1, 0, 0, 0, },
 174         { "telco",      telcolookup,    telcotrans,     1, 0, 0, 0, },
 175         { 0 },
 176 };
 177
 178 QLock ipifclock;
 179 Ipifc *ipifcs;
 180
 181 char    eaddr[16];              /* ascii ethernet address */
 182 char    ipaddr[64];             /* ascii internet address */
 183 uchar   ipa[IPaddrlen];         /* binary internet address */
 184 char    *mysysname;
 185
 186 Network *netlist;               /* networks ordered by preference */
 187 Network *last;
 188
 189 static void
 190 nstrcpy(char *to, char *from, int len)
 191 {
 192         strncpy(to, from, len);
 193         to[len-1] = 0;
 194 }
 195
 196 void
 197 usage(void)
 198 {
 199         fprint(2, "usage: %s [-dn] [-f ndb-file] [-x netmtpt]\n", argv0);
 200         exits("usage");
 201 }
 202
 203 /*
 204  * based on libthread's threadsetname, but drags in less library code.
 205  * actually just sets the arguments displayed.
 206  */
 207 void
 208 procsetname(char *fmt, ...)
 209 {
 210         int fd;
 211         char *cmdname;
 212         char buf[128];
 213         va_list arg;
 214
 215         va_start(arg, fmt);
 216         cmdname = vsmprint(fmt, arg);
 217         va_end(arg);
 218         if (cmdname == nil)
 219                 return;
 220         snprint(buf, sizeof buf, "#p/%d/args", getpid());
 221         if((fd = open(buf, OWRITE)) >= 0){
 222                 write(fd, cmdname, strlen(cmdname)+1);
 223                 close(fd);
 224         }
 225         free(cmdname);
 226 }
 227
 228 void
 229 main(int argc, char *argv[])
 230 {
 231         int justsetname;
 232         char ext[Maxpath], servefile[Maxpath];
 233
 234         justsetname = 0;
 235         setnetmtpt(mntpt, sizeof(mntpt), nil);
 236         ext[0] = 0;
 237         ARGBEGIN{
 238         case '4':
 239                 ipv6lookups = 0;
 240                 break;
 241         case 'd':
 242                 debug = 1;
 243                 break;
 244         case 'f':
 245                 dbfile = EARGF(usage());
 246                 break;
 247         case 'n':
 248                 justsetname = 1;
 249                 break;
 250         case 'x':
 251                 setnetmtpt(mntpt, sizeof(mntpt), EARGF(usage()));
 252                 setext(ext, sizeof(ext), mntpt);
 253                 break;
 254         }ARGEND
 255         USED(argc);
 256         USED(argv);
 257
 258         snprint(netndb, sizeof(netndb), "%s/ndb", mntpt);
 259
 260         fmtinstall('E', eipfmt);
 261         fmtinstall('I', eipfmt);
 262         fmtinstall('M', eipfmt);
 263         fmtinstall('F', fcallfmt);
 264
 265         ndbinit();
 266         netinit(0);
 267
 268         if(!justsetname){
 269                 snprint(servefile, sizeof(servefile), "#s/cs%s", ext);
 270                 unmount(servefile, mntpt);
 271                 remove(servefile);
 272
 273                 rfork(RFREND|RFNOTEG);
 274                 csuser = estrdup(getuser());
 275                 mountinit(servefile, mntpt);
 276                 io();
 277         }
 278         exits(0);
 279 }
 280
 281 /*
 282  *  if a mount point is specified, set the cs extention to be the mount point
 283  *  with '_'s replacing '/'s
 284  */
 285 void
 286 setext(char *ext, int n, char *p)
 287 {
 288         int i, c;
 289
 290         n--;
 291         for(i = 0; i < n; i++){
 292                 c = p[i];
 293                 if(c == 0)
 294                         break;
 295                 if(c == '/')
 296                         c = '_';
 297                 ext[i] = c;
 298         }
 299         ext[i] = 0;
 300 }
 301
 302 void
 303 mountinit(char *service, char *mntpt)
 304 {
 305         int f;
 306         int p[2];
 307         char buf[32];
 308
 309         if(pipe(p) < 0)
 310                 error("pipe failed");
 311
 312         /*
 313          *  make a /srv/cs
 314          */
 315         f = create(service, OWRITE|ORCLOSE, 0666);
 316         if(f < 0)
 317                 error(service);
 318         snprint(buf, sizeof(buf), "%d", p[1]);
 319         if(write(f, buf, strlen(buf)) != strlen(buf))
 320                 error("write /srv/cs");
 321
 322         switch(rfork(RFFDG|RFPROC|RFNAMEG)){
 323         case 0:
 324                 close(p[1]);
 325                 procsetname("%s", mntpt);
 326                 break;
 327         case -1:
 328                 error("fork failed");
 329         default:
 330                 /*
 331                  *  put ourselves into the file system
 332                  */
 333                 close(p[0]);
 334                 if(mount(p[1], -1, mntpt, MAFTER, "") < 0)
 335                         error("mount failed");
 336                 _exits(0);
 337         }
 338         mfd[0] = mfd[1] = p[0];
 339 }
 340
 341 void
 342 ndbinit(void)
 343 {
 344         db = ndbopen(dbfile);
 345         if(db == nil)
 346                 error("can't open network database");
 347
 348         for(netdb = db; netdb != nil; netdb = netdb->next)
 349                 if(strcmp(netdb->file, netndb) == 0)
 350                         return;
 351
 352         netdb = ndbopen(netndb);
 353         if(netdb != nil){
 354                 netdb->nohash = 1;
 355                 db = ndbcat(netdb, db);
 356         }
 357 }
 358
 359 Mfile*
 360 newfid(int fid)
 361 {
 362         Mlist *f, *ff;
 363         Mfile *mf;
 364
 365         ff = nil;
 366         for(f = mlist; f != nil; f = f->next)
 367                 if(f->mf.busy && f->mf.fid == fid)
 368                         return &f->mf;
 369                 else if(ff == nil && !f->mf.busy && !f->mf.ref)
 370                         ff = f;
 371         if(ff == nil){
 372                 ff = emalloc(sizeof *f);
 373                 ff->next = mlist;
 374                 mlist = ff;
 375         }
 376         mf = &ff->mf;
 377         memset(mf, 0, sizeof *mf);
 378         mf->fid = fid;
 379         return mf;
 380 }
 381
 382 Job*
 383 newjob(void)
 384 {
 385         Job *job;
 386
 387         job = emalloc(sizeof *job);
 388         qlock(&joblock);
 389         job->next = joblist;
 390         joblist = job;
 391         job->request.tag = -1;
 392         qunlock(&joblock);
 393         return job;
 394 }
 395
 396 void
 397 freejob(Job *job)
 398 {
 399         Job **l;
 400
 401         qlock(&joblock);
 402         for(l = &joblist; *l != nil; l = &(*l)->next){
 403                 if((*l) == job){
 404                         *l = job->next;
 405                         break;
 406                 }
 407         }
 408         qunlock(&joblock);
 409         free(job);
 410 }
 411
 412 void
 413 flushjob(int tag)
 414 {
 415         Job *job;
 416
 417         qlock(&joblock);
 418         for(job = joblist; job != nil; job = job->next){
 419                 if(job->request.tag == tag && job->request.type != Tflush){
 420                         job->flushed = 1;
 421                         break;
 422                 }
 423         }
 424         qunlock(&joblock);
 425 }
 426
 427 void
 428 io(void)
 429 {
 430         long n;
 431         Mfile *mf;
 432         int slaveflag;
 433         uchar mdata[IOHDRSZ + Maxfdata];
 434         Job *job;
 435
 436         /*
 437          *  if we ask dns to fulfill requests,
 438          *  a slave process is created to wait for replies.  The
 439          *  master process returns immediately via a longjmp
 440          *  through 'masterjmp'.
 441          *
 442          *  *isslave is a pointer into the call stack to a variable
 443          *  that tells whether or not the current process is a slave.
 444          */
 445         slaveflag = 0;          /* init slave variable */
 446         isslave = &slaveflag;
 447         setjmp(masterjmp);
 448
 449         for(;;){
 450                 n = read9pmsg(mfd[0], mdata, sizeof mdata);
 451                 if(n < 0)
 452                         error("mount read");
 453                 if(n == 0)
 454                         break;
 455                 job = newjob();
 456                 if(convM2S(mdata, n, &job->request) != n){
 457                         syslog(1, logfile, "format error %ux %ux %ux %ux %ux",
 458                                 mdata[0], mdata[1], mdata[2], mdata[3], mdata[4]);
 459                         freejob(job);
 460                         break;
 461                 }
 462                 qlock(&dblock);
 463                 mf = newfid(job->request.fid);
 464                 if(debug)
 465                         syslog(0, logfile, "%F", &job->request);
 466
 467                 switch(job->request.type){
 468                 default:
 469                         syslog(1, logfile, "unknown request type %d", job->request.type);
 470                         break;
 471                 case Tversion:
 472                         rversion(job);
 473                         break;
 474                 case Tauth:
 475                         rauth(job);
 476                         break;
 477                 case Tflush:
 478                         rflush(job);
 479                         break;
 480                 case Tattach:
 481                         rattach(job, mf);
 482                         break;
 483                 case Twalk:
 484                         rwalk(job, mf);
 485                         break;
 486                 case Topen:
 487                         ropen(job, mf);
 488                         break;
 489                 case Tcreate:
 490                         rcreate(job, mf);
 491                         break;
 492                 case Tread:
 493                         rread(job, mf);
 494                         break;
 495                 case Twrite:
 496                         rwrite(job, mf);
 497                         break;
 498                 case Tclunk:
 499                         rclunk(job, mf);
 500                         break;
 501                 case Tremove:
 502                         rremove(job, mf);
 503                         break;
 504                 case Tstat:
 505                         rstat(job, mf);
 506                         break;
 507                 case Twstat:
 508                         rwstat(job, mf);
 509                         break;
 510                 }
 511                 qunlock(&dblock);
 512
 513                 freejob(job);
 514
 515                 /*
 516                  *  slave processes die after replying
 517                  */
 518                 if(*isslave){
 519                         if(debug)
 520                                 syslog(0, logfile, "slave death %d", getpid());
 521                         adec(&active);
 522                         _exits(0);
 523                 }
 524         }
 525 }
 526
 527 void
 528 rversion(Job *job)
 529 {
 530         if(job->request.msize > IOHDRSZ + Maxfdata)
 531                 job->reply.msize = IOHDRSZ + Maxfdata;
 532         else
 533                 job->reply.msize = job->request.msize;
 534         if(strncmp(job->request.version, "9P2000", 6) != 0)
 535                 sendmsg(job, "unknown 9P version");
 536         else{
 537                 job->reply.version = "9P2000";
 538                 sendmsg(job, nil);
 539         }
 540 }
 541
 542 void
 543 rauth(Job *job)
 544 {
 545         sendmsg(job, "cs: authentication not required");
 546 }
 547
 548 /*
 549  *  don't flush till all the slaves are done
 550  */
 551 void
 552 rflush(Job *job)
 553 {
 554         flushjob(job->request.oldtag);
 555         sendmsg(job, nil);
 556 }
 557
 558 void
 559 rattach(Job *job, Mfile *mf)
 560 {
 561         if(mf->busy == 0){
 562                 mf->busy = 1;
 563                 mf->user = estrdup(job->request.uname);
 564         }
 565         mf->qid.vers = vers++;
 566         mf->qid.type = QTDIR;
 567         mf->qid.path = 0LL;
 568         job->reply.qid = mf->qid;
 569         sendmsg(job, nil);
 570 }
 571
 572
 573 char*
 574 rwalk(Job *job, Mfile *mf)
 575 {
 576         char *err;
 577         char **elems;
 578         int nelems;
 579         int i;
 580         Mfile *nmf;
 581         Qid qid;
 582
 583         err = nil;
 584         nmf = nil;
 585         elems = job->request.wname;
 586         nelems = job->request.nwname;
 587         job->reply.nwqid = 0;
 588
 589         if(job->request.newfid != job->request.fid){
 590                 /* clone fid */
 591                 nmf = newfid(job->request.newfid);
 592                 if(nmf->busy){
 593                         nmf = nil;
 594                         err = "clone to used channel";
 595                         goto send;
 596                 }
 597                 *nmf = *mf;
 598                 nmf->user = estrdup(mf->user);
 599                 nmf->fid = job->request.newfid;
 600                 nmf->qid.vers = vers++;
 601                 mf = nmf;
 602         }
 603         /* else nmf will be nil */
 604
 605         qid = mf->qid;
 606         if(nelems > 0){
 607                 /* walk fid */
 608                 for(i=0; i<nelems && i<MAXWELEM; i++){
 609                         if((qid.type & QTDIR) == 0){
 610                                 err = "not a directory";
 611                                 break;
 612                         }
 613                         if(strcmp(elems[i], "..") == 0 || strcmp(elems[i], ".") == 0){
 614                                 qid.type = QTDIR;
 615                                 qid.path = Qdir;
 616     Found:
 617                                 job->reply.wqid[i] = qid;
 618                                 job->reply.nwqid++;
 619                                 continue;
 620                         }
 621                         if(strcmp(elems[i], "cs") == 0){
 622                                 qid.type = QTFILE;
 623                                 qid.path = Qcs;
 624                                 goto Found;
 625                         }
 626                         err = "file does not exist";
 627                         break;
 628                 }
 629         }
 630
 631     send:
 632         if(nmf != nil && (err!=nil || job->reply.nwqid<nelems)){
 633                 cleanmf(nmf);
 634                 free(nmf->user);
 635                 nmf->user = nil;
 636                 nmf->busy = 0;
 637                 nmf->fid = 0;
 638         }
 639         if(err == nil)
 640                 mf->qid = qid;
 641         sendmsg(job, err);
 642         return err;
 643 }
 644
 645 void
 646 ropen(Job *job, Mfile *mf)
 647 {
 648         int mode;
 649         char *err;
 650
 651         err = nil;
 652         mode = job->request.mode;
 653         if(mf->qid.type & QTDIR){
 654                 if(mode)
 655                         err = "permission denied";
 656         }
 657         job->reply.qid = mf->qid;
 658         job->reply.iounit = 0;
 659         sendmsg(job, err);
 660 }
 661
 662 void
 663 rcreate(Job *job, Mfile *mf)
 664 {
 665         USED(mf);
 666         sendmsg(job, "creation permission denied");
 667 }
 668
 669 void
 670 rread(Job *job, Mfile *mf)
 671 {
 672         int i, n, cnt;
 673         long off, toff, clock;
 674         Dir dir;
 675         uchar buf[Maxfdata];
 676         char *err;
 677
 678         n = 0;
 679         err = nil;
 680         off = job->request.offset;
 681         cnt = job->request.count;
 682         mf->ref++;
 683
 684         if(mf->qid.type & QTDIR){
 685                 clock = time(0);
 686                 if(off == 0){
 687                         memset(&dir, 0, sizeof dir);
 688                         dir.name = "cs";
 689                         dir.qid.type = QTFILE;
 690                         dir.qid.vers = vers;
 691                         dir.qid.path = Qcs;
 692                         dir.mode = 0666;
 693                         dir.length = 0;
 694                         dir.uid = mf->user;
 695                         dir.gid = mf->user;
 696                         dir.muid = mf->user;
 697                         dir.atime = clock;      /* wrong */
 698                         dir.mtime = clock;      /* wrong */
 699                         n = convD2M(&dir, buf, sizeof buf);
 700                 }
 701                 job->reply.data = (char*)buf;
 702                 goto send;
 703         }
 704
 705         for(;;){
 706                 /* look for an answer at the right offset */
 707                 toff = 0;
 708                 for(i = 0; mf->reply[i] != nil && i < mf->nreply; i++){
 709                         n = mf->replylen[i];
 710                         if(off < toff + n)
 711                                 break;
 712                         toff += n;
 713                 }
 714                 if(i < mf->nreply)
 715                         break;          /* got something to return */
 716
 717                 /* try looking up more answers */
 718                 if(lookup(mf) == 0 || job->flushed){
 719                         /* no more */
 720                         n = 0;
 721                         goto send;
 722                 }
 723         }
 724
 725         /* give back a single reply (or part of one) */
 726         job->reply.data = mf->reply[i] + (off - toff);
 727         if(cnt > toff - off + n)
 728                 n = toff - off + n;
 729         else
 730                 n = cnt;
 731
 732 send:
 733         job->reply.count = n;
 734         sendmsg(job, err);
 735
 736         if(--mf->ref == 0 && mf->busy == 0)
 737                 cleanmf(mf);
 738 }
 739
 740 void
 741 cleanmf(Mfile *mf)
 742 {
 743         int i;
 744
 745         if(mf->net != nil){
 746                 free(mf->net);
 747                 mf->net = nil;
 748         }
 749         if(mf->host != nil){
 750                 free(mf->host);
 751                 mf->host = nil;
 752         }
 753         if(mf->serv != nil){
 754                 free(mf->serv);
 755                 mf->serv = nil;
 756         }
 757         if(mf->rem != nil){
 758                 free(mf->rem);
 759                 mf->rem = nil;
 760         }
 761         for(i = 0; i < mf->nreply; i++){
 762                 free(mf->reply[i]);
 763                 mf->reply[i] = nil;
 764                 mf->replylen[i] = 0;
 765         }
 766         mf->nreply = 0;
 767         mf->nextnet = netlist;
 768 }
 769
 770 void
 771 rwrite(Job *job, Mfile *mf)
 772 {
 773         int cnt, n;
 774         char *err;
 775         char *field[4];
 776         char curerr[64];
 777
 778         err = nil;
 779         cnt = job->request.count;
 780         if(mf->qid.type & QTDIR){
 781                 err = "can't write directory";
 782                 goto send;
 783         }
 784         if(cnt >= Maxrequest){
 785                 err = "request too long";
 786                 goto send;
 787         }
 788         job->request.data[cnt] = 0;
 789
 790         if(strcmp(mf->user, "none") == 0 || strcmp(mf->user, csuser) != 0)
 791                 goto query;     /* skip special commands if not owner */
 792
 793         /*
 794          *  toggle debugging
 795          */
 796         if(strncmp(job->request.data, "debug", 5)==0){
 797                 debug ^= 1;
 798                 syslog(1, logfile, "debug %d", debug);
 799                 goto send;
 800         }
 801
 802         /*
 803          *  toggle ipv6 lookups
 804          */
 805         if(strncmp(job->request.data, "ipv6", 4)==0){
 806                 ipv6lookups ^= 1;
 807                 syslog(1, logfile, "ipv6lookups %d", ipv6lookups);
 808                 goto send;
 809         }
 810
 811         /*
 812          *  toggle debugging
 813          */
 814         if(strncmp(job->request.data, "paranoia", 8)==0){
 815                 paranoia ^= 1;
 816                 syslog(1, logfile, "paranoia %d", paranoia);
 817                 goto send;
 818         }
 819
 820         /*
 821          *  add networks to the default list
 822          */
 823         if(strncmp(job->request.data, "add ", 4)==0){
 824                 if(job->request.data[cnt-1] == '\n')
 825                         job->request.data[cnt-1] = 0;
 826                 netadd(job->request.data+4);
 827                 readipinterfaces();
 828                 goto send;
 829         }
 830
 831         /*
 832          *  refresh all state
 833          */
 834         if(strncmp(job->request.data, "refresh", 7)==0){
 835                 netinit(1);
 836                 goto send;
 837         }
 838
 839 query:
 840         if(mf->ref){
 841                 err = "query already in progress";
 842                 goto send;
 843         }
 844         mf->ref++;
 845
 846         /* start transaction with a clean slate */
 847         cleanmf(mf);
 848
 849         /*
 850          *  look for a general query
 851          */
 852         if(*job->request.data == '!'){
 853                 err = genquery(mf, job->request.data+1);
 854                 goto done;
 855         }
 856
 857         if(debug)
 858                 syslog(0, logfile, "write %s", job->request.data);
 859         if(paranoia)
 860                 syslog(0, paranoiafile, "write %s by %s", job->request.data, mf->user);
 861         /*
 862          *  break up name
 863          */
 864         n = getfields(job->request.data, field, 4, 1, "!");
 865         switch(n){
 866         case 1:
 867                 mf->net = estrdup("net");
 868                 mf->host = estrdup(field[0]);
 869                 break;
 870         case 4:
 871                 mf->rem = estrdup(field[3]);
 872                 /* fall through */
 873         case 3:
 874                 mf->serv = estrdup(field[2]);
 875                 /* fall through */
 876         case 2:
 877                 mf->host = estrdup(field[1]);
 878                 mf->net = estrdup(field[0]);
 879                 break;
 880         }
 881
 882         /*
 883          *  do the first net worth of lookup
 884          */
 885         if(lookup(mf) == 0){
 886                 rerrstr(curerr, sizeof curerr);
 887                 err = curerr;
 888         }
 889
 890 done:
 891         if(--mf->ref == 0 && mf->busy == 0)
 892                 cleanmf(mf);
 893
 894 send:
 895         job->reply.count = cnt;
 896         sendmsg(job, err);
 897 }
 898
 899 void
 900 rclunk(Job *job, Mfile *mf)
 901 {
 902         if(mf->ref == 0)
 903                 cleanmf(mf);
 904         free(mf->user);
 905         mf->user = nil;
 906         mf->fid = 0;
 907         mf->busy = 0;
 908         sendmsg(job, nil);
 909 }
 910
 911 void
 912 rremove(Job *job, Mfile *mf)
 913 {
 914         USED(mf);
 915         sendmsg(job, "remove permission denied");
 916 }
 917
 918 void
 919 rstat(Job *job, Mfile *mf)
 920 {
 921         Dir dir;
 922         uchar buf[IOHDRSZ+Maxfdata];
 923
 924         memset(&dir, 0, sizeof dir);
 925         if(mf->qid.type & QTDIR){
 926                 dir.name = ".";
 927                 dir.mode = DMDIR|0555;
 928         } else {
 929                 dir.name = "cs";
 930                 dir.mode = 0666;
 931         }
 932         dir.qid = mf->qid;
 933         dir.length = 0;
 934         dir.uid = mf->user;
 935         dir.gid = mf->user;
 936         dir.muid = mf->user;
 937         dir.atime = dir.mtime = time(0);
 938         job->reply.nstat = convD2M(&dir, buf, sizeof buf);
 939         job->reply.stat = buf;
 940         sendmsg(job, nil);
 941 }
 942
 943 void
 944 rwstat(Job *job, Mfile *mf)
 945 {
 946         USED(mf);
 947         sendmsg(job, "wstat permission denied");
 948 }
 949
 950 void
 951 sendmsg(Job *job, char *err)
 952 {
 953         int n;
 954         uchar mdata[IOHDRSZ + Maxfdata];
 955         char ename[ERRMAX];
 956
 957         if(err){
 958                 job->reply.type = Rerror;
 959                 snprint(ename, sizeof(ename), "cs: %s", err);
 960                 job->reply.ename = ename;
 961         }else{
 962                 job->reply.type = job->request.type+1;
 963         }
 964         job->reply.tag = job->request.tag;
 965         n = convS2M(&job->reply, mdata, sizeof mdata);
 966         if(n == 0){
 967                 syslog(1, logfile, "sendmsg convS2M of %F returns 0", &job->reply);
 968                 abort();
 969         }
 970         qlock(&joblock);
 971         if(job->flushed == 0)
 972                 if(write(mfd[1], mdata, n)!=n)
 973                         error("mount write");
 974         qunlock(&joblock);
 975         if(debug)
 976                 syslog(0, logfile, "%F %d", &job->reply, n);
 977 }
 978
 979 void
 980 error(char *s)
 981 {
 982         syslog(1, logfile, "%s: %r", s);
 983         _exits(0);
 984 }
 985
 986 static int
 987 isvalidip(uchar *ip)
 988 {
 989         return ipcmp(ip, IPnoaddr) != 0 && ipcmp(ip, v4prefix) != 0;
 990 }
 991
 992 void
 993 readipinterfaces(void)
 994 {
 995         if(myipaddr(ipa, mntpt) != 0)
 996                 ipmove(ipa, IPnoaddr);
 997         sprint(ipaddr, "%I", ipa);
 998         if (debug)
 999                 syslog(0, logfile, "ipaddr is %s", ipaddr);
1000 }
1001
1002 /*
1003  *  get the system name
1004  */
1005 void
1006 ipid(void)
1007 {
1008         uchar addr[6];
1009         Ndbtuple *t, *tt;
1010         char *p, *attr;
1011         Ndbs s;
1012         int f, n;
1013         Dir *d;
1014         char buf[Maxpath];
1015
1016         /* use environment, ether addr, or ipaddr to get system name */
1017         if(mysysname == nil){
1018                 /*
1019                  *  environment has priority.
1020                  *
1021                  *  on the sgi power the default system name
1022                  *  is the ip address.  ignore that.
1023                  *
1024                  */
1025                 p = getenv("sysname");
1026                 if(p != nil && *p){
1027                         attr = ipattr(p);
1028                         if(strcmp(attr, "ip") != 0)
1029                                 mysysname = estrdup(p);
1030                 }
1031
1032                 /*
1033                  *  the /net/ndb contains what the network
1034                  *  figured out from DHCP.  use that name if
1035                  *  there is one.
1036                  */
1037                 if(mysysname == nil && netdb != nil){
1038                         ndbreopen(netdb);
1039                         for(tt = t = ndbparse(netdb); t != nil; t = t->entry){
1040                                 if(strcmp(t->attr, "sys") == 0){
1041                                         mysysname = estrdup(t->val);
1042                                         break;
1043                                 }
1044                         }
1045                         ndbfree(tt);
1046                 }
1047
1048                 /* next network database, ip address, and ether address to find a name */
1049                 if(mysysname == nil){
1050                         t = nil;
1051                         if(isvalidip(ipa))
1052                                 free(ndbgetvalue(db, &s, "ip", ipaddr, "sys", &t));
1053                         if(t == nil){
1054                                 n = 0;
1055                                 d = nil;
1056                                 f = open(mntpt, OREAD);
1057                                 if(f >= 0){
1058                                         n = dirreadall(f, &d);
1059                                         close(f);
1060                                 }
1061                                 for(f = 0; f < n; f++){
1062                                         if((d[f].mode & DMDIR) == 0 || strncmp(d[f].name, "ether", 5) != 0)
1063                                                 continue;
1064                                         snprint(buf, sizeof buf, "%s/%s", mntpt, d[f].name);
1065                                         if(myetheraddr(addr, buf) >= 0){
1066                                                 snprint(eaddr, sizeof(eaddr), "%E", addr);
1067                                                 free(ndbgetvalue(db, &s, "ether", eaddr, "sys", &t));
1068                                                 if(t != nil)
1069                                                         break;
1070                                         }
1071                                 }
1072                                 free(d);
1073                         }
1074                         for(tt = t; tt != nil; tt = tt->entry){
1075                                 if(strcmp(tt->attr, "sys") == 0){
1076                                         mysysname = estrdup(tt->val);
1077                                         break;
1078                                 }
1079                         }
1080                         ndbfree(t);
1081                 }
1082
1083                 /* nothing else worked, use the ip address */
1084                 if(mysysname == nil && isvalidip(ipa))
1085                         mysysname = estrdup(ipaddr);
1086
1087
1088                 /* set /dev/sysname if we now know it */
1089                 if(mysysname != nil){
1090                         f = open("/dev/sysname", OWRITE);
1091                         if(f >= 0){
1092                                 write(f, mysysname, strlen(mysysname));
1093                                 close(f);
1094                         }
1095                 }
1096         }
1097 }
1098
1099 /*
1100  *  Set up a list of default networks by looking for
1101  *  /net/^*^/clone.
1102  */
1103 void
1104 netinit(int background)
1105 {
1106         char clone[Maxpath];
1107         Network *np;
1108
1109         if(background){
1110                 switch(rfork(RFPROC|RFNOTEG|RFMEM|RFNOWAIT)){
1111                 case 0:
1112                         break;
1113                 default:
1114                         return;
1115                 }
1116                 qlock(&netlock);
1117         }
1118
1119         /* add the mounted networks to the default list */
1120         for(np = network; np->net != nil; np++){
1121                 if(np->considered)
1122                         continue;
1123                 snprint(clone, sizeof(clone), "%s/%s/clone", mntpt, np->net);
1124                 if(access(clone, AEXIST) < 0)
1125                         continue;
1126                 if(netlist != nil)
1127                         last->next = np;
1128                 else
1129                         netlist = np;
1130                 last = np;
1131                 np->next = nil;
1132                 np->considered = 1;
1133         }
1134
1135         /* find out what our ip address is */
1136         readipinterfaces();
1137
1138         /* set the system name if we need to, these days ip is all we have */
1139         ipid();
1140
1141         if(debug)
1142                 syslog(0, logfile, "mysysname %s eaddr %s ipaddr %s ipa %I",
1143                         mysysname?mysysname:"???", eaddr, ipaddr, ipa);
1144
1145         if(background){
1146                 qunlock(&netlock);
1147                 _exits(0);
1148         }
1149 }
1150
1151 /*
1152  *  add networks to the standard list
1153  */
1154 void
1155 netadd(char *p)
1156 {
1157         Network *np;
1158         char *field[12];
1159         int i, n;
1160
1161         n = getfields(p, field, 12, 1, " ");
1162         for(i = 0; i < n; i++){
1163                 for(np = network; np->net != nil; np++){
1164                         if(strcmp(field[i], np->net) != 0)
1165                                 continue;
1166                         if(np->considered)
1167                                 break;
1168                         if(netlist != nil)
1169                                 last->next = np;
1170                         else
1171                                 netlist = np;
1172                         last = np;
1173                         np->next = nil;
1174                         np->considered = 1;
1175                 }
1176         }
1177 }
1178
1179 int
1180 lookforproto(Ndbtuple *t, char *proto)
1181 {
1182         for(; t != nil; t = t->entry)
1183                 if(strcmp(t->attr, "proto") == 0 && strcmp(t->val, proto) == 0)
1184                         return 1;
1185         return 0;
1186 }
1187
1188 /*
1189  *  lookup a request.  the network "net" means we should pick the
1190  *  best network to get there.
1191  */
1192 int
1193 lookup(Mfile *mf)
1194 {
1195         Network *np;
1196         char *cp;
1197         Ndbtuple *nt, *t;
1198         char reply[Maxreply];
1199         int i, rv;
1200         int hack;
1201
1202         /* open up the standard db files */
1203         if(db == nil)
1204                 ndbinit();
1205         if(db == nil)
1206                 error("can't open mf->network database\n");
1207
1208         if(mf->net == nil)
1209                 return 0;       /* must have been a genquery */
1210
1211         rv = 0;
1212         if(strcmp(mf->net, "net") == 0){
1213                 /*
1214                  *  go through set of default nets
1215                  */
1216                 for(np = mf->nextnet; np != nil && rv == 0; np = np->next){
1217                         nt = (*np->lookup)(np, mf->host, mf->serv);
1218                         if(nt == nil)
1219                                 continue;
1220                         hack = np->fasttimeouthack && !lookforproto(nt, np->net);
1221                         for(t = nt; mf->nreply < Nreply && t != nil; t = t->entry){
1222                                 cp = (*np->trans)(t, np, mf->serv, mf->rem, hack);
1223                                 if(cp != nil){
1224                                         /* avoid duplicates */
1225                                         for(i = 0; i < mf->nreply; i++)
1226                                                 if(strcmp(mf->reply[i], cp) == 0)
1227                                                         break;
1228                                         if(i == mf->nreply){
1229                                                 /* save the reply */
1230                                                 mf->replylen[mf->nreply] = strlen(cp);
1231                                                 mf->reply[mf->nreply++] = cp;
1232                                                 rv++;
1233                                         } else
1234                                                 free(cp);
1235                                 }
1236                         }
1237                         ndbfree(nt);
1238                 }
1239                 mf->nextnet = np;
1240                 return rv;
1241         }
1242
1243         /*
1244          *  if not /net, we only get one lookup
1245          */
1246         if(mf->nreply != 0)
1247                 return 0;
1248
1249         /*
1250          *  look for a specific network
1251          */
1252         for(np = network; np->net != nil; np++){
1253                 if(np->fasttimeouthack)
1254                         continue;
1255                 if(strcmp(np->net, mf->net) == 0)
1256                         break;
1257         }
1258
1259         if(np->net != nil){
1260                 /*
1261                  *  known network
1262                  */
1263                 nt = (*np->lookup)(np, mf->host, mf->serv);
1264                 for(t = nt; mf->nreply < Nreply && t != nil; t = t->entry){
1265                         cp = (*np->trans)(t, np, mf->serv, mf->rem, 0);
1266                         if(cp != nil){
1267                                 mf->replylen[mf->nreply] = strlen(cp);
1268                                 mf->reply[mf->nreply++] = cp;
1269                                 rv++;
1270                         }
1271                 }
1272                 ndbfree(nt);
1273                 return rv;
1274         } else {
1275                 /*
1276                  *  not a known network, don't translate host or service
1277                  */
1278                 if(mf->serv != nil)
1279                         snprint(reply, sizeof(reply), "%s/%s/clone %s!%s",
1280                                 mntpt, mf->net, mf->host, mf->serv);
1281                 else
1282                         snprint(reply, sizeof(reply), "%s/%s/clone %s",
1283                                 mntpt, mf->net, mf->host);
1284                 mf->reply[0] = estrdup(reply);
1285                 mf->replylen[0] = strlen(reply);
1286                 mf->nreply = 1;
1287                 return 1;
1288         }
1289 }
1290
1291 /*
1292  *  translate an ip service name into a port number.  If it's a numeric port
1293  *  number, look for restricted access.
1294  *
1295  *  the service '*' needs no translation.
1296  */
1297 char*
1298 ipserv(Network *np, char *name, char *buf, int blen)
1299 {
1300         char *p;
1301         int alpha = 0;
1302         int restr = 0;
1303         Ndbtuple *t, *nt;
1304         Ndbs s;
1305
1306         /* '*' means any service */
1307         if(strcmp(name, "*") == 0){
1308                 nstrcpy(buf, name, blen);
1309                 return buf;
1310         }
1311
1312         /*  see if it's numeric or symbolic */
1313         for(p = name; *p; p++){
1314                 if(isdigit(*p))
1315                         {}
1316                 else if(isalpha(*p) || *p == '-' || *p == '$')
1317                         alpha = 1;
1318                 else
1319                         return nil;
1320         }
1321         t = nil;
1322         p = nil;
1323         if(alpha){
1324                 p = ndbgetvalue(db, &s, np->net, name, "port", &t);
1325                 if(p == nil)
1326                         return nil;
1327         } else {
1328                 /* look up only for tcp ports < 1024 to get the restricted
1329                  * attribute
1330                  */
1331                 if(atoi(name) < 1024 && strcmp(np->net, "tcp") == 0)
1332                         p = ndbgetvalue(db, &s, "port", name, "port", &t);
1333                 if(p == nil)
1334                         p = estrdup(name);
1335         }
1336
1337         if(t){
1338                 for(nt = t; nt != nil; nt = nt->entry)
1339                         if(strcmp(nt->attr, "restricted") == 0)
1340                                 restr = 1;
1341                 ndbfree(t);
1342         }
1343         snprint(buf, blen, "%s%s", p, restr ? "!r" : "");
1344         free(p);
1345
1346         return buf;
1347 }
1348
1349 /*
1350  *  lookup an ip attribute
1351  */
1352 int
1353 ipattrlookup(Ndb *db, char *ipa, char *attr, char *val, int vlen)
1354 {
1355
1356         Ndbtuple *t, *nt;
1357         char *alist[2];
1358
1359         alist[0] = attr;
1360         t = ndbipinfo(db, "ip", ipa, alist, 1);
1361         if(t == nil)
1362                 return 0;
1363         for(nt = t; nt != nil; nt = nt->entry){
1364                 if(strcmp(nt->attr, attr) == 0){
1365                         nstrcpy(val, nt->val, vlen);
1366                         ndbfree(t);
1367                         return 1;
1368                 }
1369         }
1370
1371         /* we shouldn't get here */
1372         ndbfree(t);
1373         return 0;
1374 }
1375
1376 static int
1377 isv4str(char *s)
1378 {
1379         uchar ip[IPaddrlen];
1380         return parseip(ip, s) != -1 && isv4(ip);
1381 }
1382
1383 /*
1384  *  lookup (and translate) an ip destination
1385  */
1386 Ndbtuple*
1387 iplookup(Network *np, char *host, char *serv)
1388 {
1389         char *attr, *dnsname;
1390         Ndbtuple *t, *nt;
1391         Ndbs s;
1392         char ts[Maxservice];
1393         char dollar[Maxhost];
1394         uchar ip[IPaddrlen];
1395         uchar net[IPaddrlen];
1396         uchar tnet[IPaddrlen];
1397         Ipifc *ifc;
1398         Iplifc *lifc;
1399
1400         /*
1401          *  start with the service since it's the most likely to fail
1402          *  and costs the least
1403          */
1404         werrstr("can't translate address");
1405         if(serv == nil || ipserv(np, serv, ts, sizeof ts) == nil){
1406                 werrstr("can't translate service");
1407                 return nil;
1408         }
1409
1410         /* for dial strings with no host */
1411         if(strcmp(host, "*") == 0)
1412                 return ndbnew("ip", "*");
1413
1414         /*
1415          *  hack till we go v6 :: = 0.0.0.0
1416          */
1417         if(strcmp("::", host) == 0)
1418                 return ndbnew("ip", "*");
1419
1420
1421         /*
1422          *  '$' means the rest of the name is an attribute that we
1423          *  need to search for
1424          */
1425         if(*host == '$'){
1426                 if(ipattrlookup(db, ipaddr, host+1, dollar, sizeof dollar))
1427                         host = dollar;
1428         }
1429
1430         /*
1431          *  turn '[ip address]' into just 'ip address'
1432          */
1433         if(*host == '['){
1434                 char *x;
1435
1436                 if(host != dollar){
1437                         nstrcpy(dollar, host, sizeof dollar);
1438                         host = dollar;
1439                 }
1440                 if(x = strchr(++host, ']'))
1441                         *x = 0;
1442         }
1443
1444         /*
1445          *  just accept addresses
1446          */
1447         attr = ipattr(host);
1448         if(strcmp(attr, "ip") == 0)
1449                 return ndbnew("ip", host);
1450
1451         /*
1452          *  give the domain name server the first opportunity to
1453          *  resolve domain names.  if that fails try the database.
1454          */
1455         t = 0;
1456         werrstr("can't translate address");
1457         if(strcmp(attr, "dom") == 0)
1458                 t = dnsiplookup(host, &s, !np->v4only);
1459         if(t == nil)
1460                 free(ndbgetvalue(db, &s, attr, host, "ip", &t));
1461         if(t == nil){
1462                 dnsname = ndbgetvalue(db, &s, attr, host, "dom", nil);
1463                 if(dnsname){
1464                         t = dnsiplookup(dnsname, &s, !np->v4only);
1465                         free(dnsname);
1466                 }
1467         }
1468         if(t == nil)
1469                 t = dnsiplookup(host, &s, !np->v4only);
1470         if(t == nil)
1471                 return nil;
1472
1473         /*
1474          *  reorder the tuple to have the matched line first and
1475          *  save that in the request structure.
1476          */
1477         t = reorder(t, s.t);
1478
1479         /*
1480          * reorder according to our interfaces
1481          */
1482         qlock(&ipifclock);
1483         for(ifc = ipifcs; ifc != nil; ifc = ifc->next){
1484                 for(lifc = ifc->lifc; lifc != nil; lifc = lifc->next){
1485                         maskip(lifc->ip, lifc->mask, net);
1486                         for(nt = t; nt; nt = nt->entry){
1487                                 if(strcmp(nt->attr, "ip") != 0)
1488                                         continue;
1489                                 parseip(ip, nt->val);
1490                                 maskip(ip, lifc->mask, tnet);
1491                                 if(memcmp(net, tnet, IPaddrlen) == 0){
1492                                         t = reorder(t, nt);
1493                                         qunlock(&ipifclock);
1494                                         return t;
1495                                 }
1496                         }
1497                 }
1498         }
1499         qunlock(&ipifclock);
1500
1501         return t;
1502 }
1503
1504 /*
1505  *  translate an ip address
1506  */
1507 char*
1508 iptrans(Ndbtuple *t, Network *np, char *serv, char *rem, int hack)
1509 {
1510         char ts[Maxservice];
1511         char reply[Maxreply];
1512         char x[Maxservice];
1513
1514         if(strcmp(t->attr, "ip") != 0)
1515                 return nil;
1516
1517         if(serv == nil || ipserv(np, serv, ts, sizeof ts) == nil){
1518                 werrstr("can't translate service");
1519                 return nil;
1520         }
1521         if(rem != nil)
1522                 snprint(x, sizeof(x), "!%s", rem);
1523         else
1524                 *x = 0;
1525
1526         if(*t->val == '*')
1527                 snprint(reply, sizeof(reply), "%s/%s/clone %s%s",
1528                         mntpt, np->net, ts, x);
1529         else {
1530                 if(np->v4only && !isv4str(t->val))
1531                         return nil;
1532
1533                 if(np->v6only && isv4str(t->val))
1534                         return nil;
1535
1536                 snprint(reply, sizeof(reply), "%s/%s/clone %s!%s%s%s",
1537                         mntpt, np->net, t->val, ts, x, hack? "!fasttimeout": "");
1538         }
1539
1540         return estrdup(reply);
1541 }
1542
1543 /*
1544  *  lookup a telephone number
1545  */
1546 Ndbtuple*
1547 telcolookup(Network *np, char *host, char *serv)
1548 {
1549         Ndbtuple *t;
1550         Ndbs s;
1551
1552         USED(np, serv);
1553
1554         werrstr("can't translate address");
1555         free(ndbgetvalue(db, &s, "sys", host, "telco", &t));
1556         if(t == nil)
1557                 return ndbnew("telco", host);
1558
1559         return reorder(t, s.t);
1560 }
1561
1562 /*
1563  *  translate a telephone address
1564  */
1565 char*
1566 telcotrans(Ndbtuple *t, Network *np, char *serv, char *rem, int)
1567 {
1568         char reply[Maxreply];
1569         char x[Maxservice];
1570
1571         if(strcmp(t->attr, "telco") != 0)
1572                 return nil;
1573
1574         if(rem != nil)
1575                 snprint(x, sizeof(x), "!%s", rem);
1576         else
1577                 *x = 0;
1578         if(serv != nil)
1579                 snprint(reply, sizeof(reply), "%s/%s/clone %s!%s%s", mntpt, np->net,
1580                         t->val, serv, x);
1581         else
1582                 snprint(reply, sizeof(reply), "%s/%s/clone %s%s", mntpt, np->net,
1583                         t->val, x);
1584         return estrdup(reply);
1585 }
1586
1587 /*
1588  *  reorder the tuple to put x's line first in the entry
1589  */
1590 Ndbtuple*
1591 reorder(Ndbtuple *t, Ndbtuple *x)
1592 {
1593         Ndbtuple *nt;
1594         Ndbtuple *line;
1595
1596         /* find start of this entry's line */
1597         for(line = x; line->entry == line->line; line = line->line)
1598                 ;
1599         line = line->line;
1600         if(line == t)
1601                 return t;       /* already the first line */
1602
1603         /* remove this line and everything after it from the entry */
1604         for(nt = t; nt->entry != line; nt = nt->entry)
1605                 ;
1606         nt->entry = nil;
1607
1608         /* make that the start of the entry */
1609         for(nt = line; nt->entry != nil; nt = nt->entry)
1610                 ;
1611         nt->entry = t;
1612         return line;
1613 }
1614
1615 /*
1616  *  create a slave process to handle a request to avoid one request blocking
1617  *  another.  parent returns to job loop.
1618  */
1619 void
1620 slave(char *host)
1621 {
1622         if(*isslave)
1623                 return;         /* we're already a slave process */
1624         if(ainc(&active) >= Maxactive){
1625                 adec(&active);
1626                 return;
1627         }
1628         switch(rfork(RFPROC|RFNOTEG|RFMEM|RFNOWAIT)){
1629         case -1:
1630                 adec(&active);
1631                 break;
1632         case 0:
1633                 *isslave = 1;
1634                 if(debug)
1635                         syslog(0, logfile, "slave %d", getpid());
1636                 procsetname("%s", host);
1637                 break;
1638         default:
1639                 longjmp(masterjmp, 1);
1640         }
1641
1642 }
1643
1644 static Ndbtuple*
1645 dnsip6lookup(char *mntpt, char *buf, Ndbtuple *t)
1646 {
1647         Ndbtuple *t6, *tt;
1648
1649         t6 = dnsquery(mntpt, buf, "ipv6");      /* lookup AAAA dns RRs */
1650         if (t6 == nil)
1651                 return t;
1652
1653         /* convert ipv6 attr to ip */
1654         for (tt = t6; tt != nil; tt = tt->entry)
1655                 if (strcmp(tt->attr, "ipv6") == 0)
1656                         strcpy(tt->attr, "ip");
1657
1658         if (t == nil)
1659                 return t6;
1660
1661         /* append t6 list to t list */
1662         for (tt = t; tt->entry != nil; tt = tt->entry)
1663                 ;
1664         tt->entry = t6;
1665         return t;
1666 }
1667
1668 /*
1669  *  call the dns process and have it try to translate a name
1670  */
1671 Ndbtuple*
1672 dnsiplookup(char *host, Ndbs *s, int v6)
1673 {
1674         char buf[Maxreply];
1675         Ndbtuple *t;
1676
1677         qunlock(&dblock);
1678         slave(host);
1679         if(*isslave == 0){
1680                 qlock(&dblock);
1681                 werrstr("too much activity");
1682                 return nil;
1683         }
1684
1685         if(strcmp(ipattr(host), "ip") == 0)
1686                 t = dnsquery(mntpt, host, "ptr");
1687         else {
1688                 t = dnsquery(mntpt, host, "ip");
1689                 /* special case: query ipv6 (AAAA dns RR) too */
1690                 if (v6 && ipv6lookups)
1691                         t = dnsip6lookup(mntpt, host, t);
1692         }
1693         s->t = t;
1694
1695         if(t == nil){
1696                 rerrstr(buf, sizeof buf);
1697                 if(strstr(buf, "exist") != nil)
1698                         werrstr("can't translate address: %s", buf);
1699                 else if(strstr(buf, "dns failure") != nil)
1700                         werrstr("temporary problem: %s", buf);
1701         }
1702
1703         qlock(&dblock);
1704         return t;
1705 }
1706
1707 int
1708 qmatch(Ndbtuple *t, char **attr, char **val, int n)
1709 {
1710         int i, found;
1711         Ndbtuple *nt;
1712
1713         for(i = 1; i < n; i++){
1714                 found = 0;
1715                 for(nt = t; nt != nil; nt = nt->entry)
1716                         if(strcmp(attr[i], nt->attr) == 0)
1717                                 if(strcmp(val[i], "*") == 0
1718                                 || strcmp(val[i], nt->val) == 0){
1719                                         found = 1;
1720                                         break;
1721                                 }
1722                 if(found == 0)
1723                         break;
1724         }
1725         return i == n;
1726 }
1727
1728 void
1729 qreply(Mfile *mf, Ndbtuple *t)
1730 {
1731         Ndbtuple *nt;
1732         String *s;
1733
1734         s = s_new();
1735         for(nt = t; mf->nreply < Nreply && nt != nil; nt = nt->entry){
1736                 s_append(s, nt->attr);
1737                 s_append(s, "=");
1738                 s_append(s, nt->val);
1739
1740                 if(nt->line != nt->entry){
1741                         mf->replylen[mf->nreply] = s_len(s);
1742                         mf->reply[mf->nreply++] = estrdup(s_to_c(s));
1743                         s_restart(s);
1744                 } else
1745                         s_append(s, " ");
1746         }
1747         s_free(s);
1748 }
1749
1750 enum
1751 {
1752         Maxattr=        32,
1753 };
1754
1755 /*
1756  *  generic query lookup.  The query is of one of the following
1757  *  forms:
1758  *
1759  *  attr1=val1 attr2=val2 attr3=val3 ...
1760  *
1761  *  returns the matching tuple
1762  *
1763  *  ipinfo attr=val attr1 attr2 attr3 ...
1764  *
1765  *  is like ipinfo and returns the attr{1-n}
1766  *  associated with the ip address.
1767  */
1768 char*
1769 genquery(Mfile *mf, char *query)
1770 {
1771         int i, n;
1772         char *p;
1773         char *attr[Maxattr];
1774         char *val[Maxattr];
1775         Ndbtuple *t;
1776         Ndbs s;
1777
1778         n = getfields(query, attr, nelem(attr), 1, " ");
1779         if(n == 0)
1780                 return "bad query";
1781
1782         if(strcmp(attr[0], "ipinfo") == 0)
1783                 return ipinfoquery(mf, attr, n);
1784
1785         /* parse pairs */
1786         for(i = 0; i < n; i++){
1787                 p = strchr(attr[i], '=');
1788                 if(p == nil)
1789                         return "bad query";
1790                 *p++ = 0;
1791                 val[i] = p;
1792         }
1793
1794         /* give dns a chance */
1795         if((strcmp(attr[0], "dom") == 0 || strcmp(attr[0], "ip") == 0) && val[0]){
1796                 t = dnsiplookup(val[0], &s, 1);
1797                 if(t != nil){
1798                         if(qmatch(t, attr, val, n)){
1799                                 qreply(mf, t);
1800                                 ndbfree(t);
1801                                 return nil;
1802                         }
1803                         ndbfree(t);
1804                 }
1805         }
1806
1807         /* first pair is always the key.  It can't be a '*' */
1808         t = ndbsearch(db, &s, attr[0], val[0]);
1809
1810         /* search is the and of all the pairs */
1811         while(t != nil){
1812                 if(qmatch(t, attr, val, n)){
1813                         qreply(mf, t);
1814                         ndbfree(t);
1815                         return nil;
1816                 }
1817
1818                 ndbfree(t);
1819                 t = ndbsnext(&s, attr[0], val[0]);
1820         }
1821
1822         return "no match";
1823 }
1824
1825 /*
1826  *  resolve an ip address
1827  */
1828 static Ndbtuple*
1829 ipresolve(char *attr, char *host)
1830 {
1831         Ndbtuple *t, *nt, **l;
1832
1833         t = iplookup(&network[Ntcp], host, "*");
1834         for(l = &t; *l != nil; ){
1835                 nt = *l;
1836                 if(strcmp(nt->attr, "ip") != 0){
1837                         *l = nt->entry;
1838                         nt->entry = nil;
1839                         ndbfree(nt);
1840                         continue;
1841                 }
1842                 nstrcpy(nt->attr, attr, sizeof(nt->attr));
1843                 l = &nt->entry;
1844         }
1845         return t;
1846 }
1847
1848 char*
1849 ipinfoquery(Mfile *mf, char **list, int n)
1850 {
1851         int i, nresolve;
1852         int resolve[Maxattr];
1853         Ndbtuple *t, *nt, **l;
1854         char *attr, *val;
1855
1856         /* skip 'ipinfo' */
1857         list++; n--;
1858
1859         if(n < 1)
1860                 return "bad query";
1861
1862         /* get search attribute=value, or assume ip=myipaddr */
1863         attr = *list;
1864         if((val = strchr(attr, '=')) != nil){
1865                 *val++ = 0;
1866                 list++;
1867                 n--;
1868         }else{
1869                 attr = "ip";
1870                 val = ipaddr;
1871         }
1872
1873         if(n < 1)
1874                 return "bad query";
1875
1876         /*
1877          *  don't let ndbipinfo resolve the addresses, we're
1878          *  better at it.
1879          */
1880         nresolve = 0;
1881         for(i = 0; i < n; i++)
1882                 if(*list[i] == '@'){            /* @attr=val ? */
1883                         list[i]++;
1884                         resolve[i] = 1;         /* we'll resolve it */
1885                         nresolve++;
1886                 } else
1887                         resolve[i] = 0;
1888
1889         t = ndbipinfo(db, attr, val, list, n);
1890         if(t == nil)
1891                 return "no match";
1892
1893         if(nresolve != 0){
1894                 for(l = &t; *l != nil;){
1895                         nt = *l;
1896
1897                         /* already an address? */
1898                         if(strcmp(ipattr(nt->val), "ip") == 0){
1899                                 l = &(*l)->entry;
1900                                 continue;
1901                         }
1902
1903                         /* user wants it resolved? */
1904                         for(i = 0; i < n; i++)
1905                                 if(strcmp(list[i], nt->attr) == 0)
1906                                         break;
1907                         if(i >= n || resolve[i] == 0){
1908                                 l = &(*l)->entry;
1909                                 continue;
1910                         }
1911
1912                         /* resolve address and replace entry */
1913                         *l = ipresolve(nt->attr, nt->val);
1914                         while(*l != nil)
1915                                 l = &(*l)->entry;
1916                         *l = nt->entry;
1917
1918                         nt->entry = nil;
1919                         ndbfree(nt);
1920                 }
1921         }
1922
1923         /* make it all one line */
1924         for(nt = t; nt != nil; nt = nt->entry){
1925                 if(nt->entry == nil)
1926                         nt->line = t;
1927                 else
1928                         nt->line = nt->entry;
1929         }
1930
1931         qreply(mf, t);
1932
1933         return nil;
1934 }
1935
1936 void*
1937 emalloc(int size)
1938 {
1939         void *x;
1940
1941         x = malloc(size);
1942         if(x == nil)
1943                 error("out of memory");
1944         memset(x, 0, size);
1945         return x;
1946 }
1947
1948 char*
1949 estrdup(char *s)
1950 {
1951         int size;
1952         char *p;
1953
1954         size = strlen(s);
1955         p = malloc(size+1);
1956         if(p == nil)
1957                 error("out of memory");
1958         memmove(p, s, size);
1959         p[size] = 0;
1960         return p;
1961 }