Blob


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 <ip.h>
8 #include <ndb.h>
9 #include <thread.h>
10 #include "dns.h"
12 enum
13 {
14 Maxrequest= 1024,
15 Ncache= 8,
16 Maxpath= 128,
17 Maxreply= 512,
18 Maxrrr= 16,
19 Maxfdata= 8192,
21 Qdir= 0,
22 Qdns= 1
23 };
25 typedef struct Mfile Mfile;
26 typedef struct Job Job;
27 typedef struct Network Network;
29 int vers; /* incremented each clone/attach */
31 struct Mfile
32 {
33 Mfile *next; /* next free mfile */
34 int ref;
36 char *user;
37 Qid qid;
38 int fid;
40 int type; /* reply type */
41 char reply[Maxreply];
42 ushort rr[Maxrrr]; /* offset of rr's */
43 ushort nrr; /* number of rr's */
44 };
46 /*
47 * active local requests
48 */
49 struct Job
50 {
51 Job *next;
52 int flushed;
53 Fcall request;
54 Fcall reply;
55 };
56 Lock joblock;
57 Job *joblist;
59 struct {
60 Lock lk;
61 Mfile *inuse; /* active mfile's */
62 } mfalloc;
64 int mfd[2];
65 int debug;
66 int traceactivity;
67 int cachedb;
68 ulong now;
69 int testing;
70 char *trace;
71 int needrefresh;
72 int resolver;
73 uchar ipaddr[IPaddrlen]; /* my ip address */
74 int maxage;
75 char *zonerefreshprogram;
76 int sendnotifies;
78 void rversion(Job*);
79 void rauth(Job*);
80 void rflush(Job*);
81 void rattach(Job*, Mfile*);
82 char* rwalk(Job*, Mfile*);
83 void ropen(Job*, Mfile*);
84 void rcreate(Job*, Mfile*);
85 void rread(Job*, Mfile*);
86 void rwrite(Job*, Mfile*, Request*);
87 void rclunk(Job*, Mfile*);
88 void rremove(Job*, Mfile*);
89 void rstat(Job*, Mfile*);
90 void rwstat(Job*, Mfile*);
91 void sendmsg(Job*, char*);
92 void mountinit(char*);
93 void io(void);
94 int fillreply(Mfile*, int);
95 Job* newjob(void);
96 void freejob(Job*);
97 void setext(char*, int, char*);
99 char *tcpaddr = "tcp!*!domain";
100 char *udpaddr = "udp!*!domain";
101 char *logfile = "dns";
102 char *dbfile;
103 char mntpt[Maxpath];
104 char *LOG;
106 void
107 usage(void)
109 fprint(2, "usage: dns [-dnrst] [-a maxage] [-f ndb-file] [-T tcpaddr] [-U udpaddr] [-x service] [-z zoneprog]\n");
110 threadexitsall("usage");
113 void
114 checkaddress(void)
116 char *u, *t;
118 u = strchr(udpaddr, '!');
119 t = strchr(tcpaddr, '!');
120 if(u && t && strcmp(u, t) != 0)
121 fprint(2, "warning: announce mismatch %s %s\n", udpaddr, tcpaddr);
124 void
125 threadmain(int argc, char *argv[])
127 int serveudp, servetcp;
128 char *service;
130 serveudp = 0;
131 servetcp = 0;
132 service = "dns";
133 ARGBEGIN{
134 case 'd':
135 debug = 1;
136 traceactivity = 1;
137 break;
138 case 'f':
139 dbfile = EARGF(usage());
140 break;
141 case 'x':
142 service = EARGF(usage());
143 break;
144 case 'r':
145 resolver = 1;
146 break;
147 case 's':
148 serveudp = 1;
149 cachedb = 1;
150 break;
151 case 't':
152 servetcp = 1;
153 cachedb = 1;
154 break;
155 case 'a':
156 maxage = atoi(EARGF(usage()));
157 break;
158 case 'z':
159 zonerefreshprogram = EARGF(usage());
160 break;
161 case 'n':
162 sendnotifies = 1;
163 break;
164 case 'U':
165 udpaddr = estrdup(netmkaddr(EARGF(usage()), "udp", "domain"));
166 break;
167 case 'T':
168 tcpaddr = estrdup(netmkaddr(EARGF(usage()), "tcp", "domain"));
169 break;
170 default:
171 usage();
172 }ARGEND
174 if(argc)
175 usage();
176 if(serveudp && servetcp)
177 checkaddress();
179 rfork(RFNOTEG);
181 /* start syslog before we fork */
182 fmtinstall('F', fcallfmt);
183 dninit();
184 if(myipaddr(ipaddr, mntpt) < 0)
185 sysfatal("can't read my ip address");
187 syslog(0, logfile, "starting dns on %I", ipaddr);
189 opendatabase();
191 mountinit(service);
193 now = time(0);
194 srand(now*getpid());
195 db2cache(1);
197 if(serveudp)
198 proccreate(dnudpserver, nil, STACK);
199 if(servetcp)
200 proccreate(dntcpserver, nil, STACK);
201 if(sendnotifies)
202 proccreate(notifyproc, nil, STACK);
204 io();
207 /*
208 * if a mount point is specified, set the cs extention to be the mount point
209 * with '_'s replacing '/'s
210 */
211 void
212 setext(char *ext, int n, char *p)
214 int i, c;
216 n--;
217 for(i = 0; i < n; i++){
218 c = p[i];
219 if(c == 0)
220 break;
221 if(c == '/')
222 c = '_';
223 ext[i] = c;
225 ext[i] = 0;
228 void
229 mountinit(char *service)
231 int p[2];
233 if(pipe(p) < 0)
234 abort(); /* "pipe failed" */;
235 if(post9pservice(p[1], service) < 0)
236 fprint(2, "post9pservice dns: %r\n");
237 close(p[1]);
238 mfd[0] = mfd[1] = p[0];
241 Mfile*
242 newfid(int fid, int needunused)
244 Mfile *mf;
246 lock(&mfalloc.lk);
247 for(mf = mfalloc.inuse; mf != nil; mf = mf->next){
248 if(mf->fid == fid){
249 unlock(&mfalloc.lk);
250 if(needunused)
251 return nil;
252 return mf;
255 if(!needunused){
256 unlock(&mfalloc.lk);
257 return nil;
259 mf = emalloc(sizeof(*mf));
260 if(mf == nil)
261 sysfatal("out of memory");
262 mf->fid = fid;
263 mf->next = mfalloc.inuse;
264 mfalloc.inuse = mf;
265 unlock(&mfalloc.lk);
266 return mf;
269 void
270 freefid(Mfile *mf)
272 Mfile **l;
274 lock(&mfalloc.lk);
275 for(l = &mfalloc.inuse; *l != nil; l = &(*l)->next){
276 if(*l == mf){
277 *l = mf->next;
278 if(mf->user)
279 free(mf->user);
280 free(mf);
281 unlock(&mfalloc.lk);
282 return;
285 sysfatal("freeing unused fid");
288 Mfile*
289 copyfid(Mfile *mf, int fid)
291 Mfile *nmf;
293 nmf = newfid(fid, 1);
294 if(nmf == nil)
295 return nil;
296 nmf->fid = fid;
297 nmf->user = estrdup(mf->user);
298 nmf->qid.type = mf->qid.type;
299 nmf->qid.path = mf->qid.path;
300 nmf->qid.vers = vers++;
301 return nmf;
304 Job*
305 newjob(void)
307 Job *job;
309 job = emalloc(sizeof(*job));
310 lock(&joblock);
311 job->next = joblist;
312 joblist = job;
313 job->request.tag = -1;
314 unlock(&joblock);
315 return job;
318 void
319 freejob(Job *job)
321 Job **l;
323 lock(&joblock);
324 for(l = &joblist; *l; l = &(*l)->next){
325 if((*l) == job){
326 *l = job->next;
327 free(job);
328 break;
331 unlock(&joblock);
334 void
335 flushjob(int tag)
337 Job *job;
339 lock(&joblock);
340 for(job = joblist; job; job = job->next){
341 if(job->request.tag == tag && job->request.type != Tflush){
342 job->flushed = 1;
343 break;
346 unlock(&joblock);
349 void
350 ioproc0(void *v)
352 long n;
353 Mfile *mf;
354 uchar mdata[IOHDRSZ + Maxfdata];
355 Request req;
356 Job *job;
358 USED(v);
360 for(;;){
361 n = read9pmsg(mfd[0], mdata, sizeof mdata);
362 if(n <= 0){
363 syslog(0, logfile, "error reading mntpt: %r");
364 break;
366 job = newjob();
367 if(convM2S(mdata, n, &job->request) != n){
368 freejob(job);
369 continue;
371 if(debug)
372 syslog(0, logfile, "%F", &job->request);
374 getactivity(&req);
375 req.aborttime = now + 60; /* don't spend more than 60 seconds */
377 mf = nil;
378 switch(job->request.type){
379 case Tversion:
380 case Tauth:
381 case Tflush:
382 break;
383 case Tattach:
384 mf = newfid(job->request.fid, 1);
385 if(mf == nil){
386 sendmsg(job, "fid in use");
387 goto skip;
389 break;
390 default:
391 mf = newfid(job->request.fid, 0);
392 if(mf == nil){
393 sendmsg(job, "unknown fid");
394 goto skip;
396 break;
399 switch(job->request.type){
400 default:
401 syslog(1, logfile, "unknown request type %d", job->request.type);
402 break;
403 case Tversion:
404 rversion(job);
405 break;
406 case Tauth:
407 rauth(job);
408 break;
409 case Tflush:
410 rflush(job);
411 break;
412 case Tattach:
413 rattach(job, mf);
414 break;
415 case Twalk:
416 rwalk(job, mf);
417 break;
418 case Topen:
419 ropen(job, mf);
420 break;
421 case Tcreate:
422 rcreate(job, mf);
423 break;
424 case Tread:
425 rread(job, mf);
426 break;
427 case Twrite:
428 rwrite(job, mf, &req);
429 break;
430 case Tclunk:
431 rclunk(job, mf);
432 break;
433 case Tremove:
434 rremove(job, mf);
435 break;
436 case Tstat:
437 rstat(job, mf);
438 break;
439 case Twstat:
440 rwstat(job, mf);
441 break;
443 skip:
444 freejob(job);
445 putactivity();
449 void
450 io(void)
452 int i;
454 for(i=0; i<Maxactive; i++)
455 proccreate(ioproc0, 0, STACK);
458 void
459 rversion(Job *job)
461 if(job->request.msize > IOHDRSZ + Maxfdata)
462 job->reply.msize = IOHDRSZ + Maxfdata;
463 else
464 job->reply.msize = job->request.msize;
465 if(strncmp(job->request.version, "9P2000", 6) != 0)
466 sendmsg(job, "unknown 9P version");
467 else{
468 job->reply.version = "9P2000";
469 sendmsg(job, 0);
473 void
474 rauth(Job *job)
476 sendmsg(job, "dns: authentication not required");
479 /*
480 * don't flush till all the slaves are done
481 */
482 void
483 rflush(Job *job)
485 flushjob(job->request.oldtag);
486 sendmsg(job, 0);
489 void
490 rattach(Job *job, Mfile *mf)
492 if(mf->user != nil)
493 free(mf->user);
494 mf->user = estrdup(job->request.uname);
495 mf->qid.vers = vers++;
496 mf->qid.type = QTDIR;
497 mf->qid.path = 0LL;
498 job->reply.qid = mf->qid;
499 sendmsg(job, 0);
502 char*
503 rwalk(Job *job, Mfile *mf)
505 char *err;
506 char **elems;
507 int nelems;
508 int i;
509 Mfile *nmf;
510 Qid qid;
512 err = 0;
513 nmf = nil;
514 elems = job->request.wname;
515 nelems = job->request.nwname;
516 job->reply.nwqid = 0;
518 if(job->request.newfid != job->request.fid){
519 /* clone fid */
520 if(job->request.newfid<0){
521 err = "clone newfid out of range";
522 goto send;
524 nmf = copyfid(mf, job->request.newfid);
525 if(nmf == nil){
526 err = "clone bad newfid";
527 goto send;
529 mf = nmf;
531 /* else nmf will be nil */
533 qid = mf->qid;
534 if(nelems > 0){
535 /* walk fid */
536 for(i=0; i<nelems && i<MAXWELEM; i++){
537 if((qid.type & QTDIR) == 0){
538 err = "not a directory";
539 break;
541 if(strcmp(elems[i], "..") == 0 || strcmp(elems[i], ".") == 0){
542 qid.type = QTDIR;
543 qid.path = Qdir;
544 Found:
545 job->reply.wqid[i] = qid;
546 job->reply.nwqid++;
547 continue;
549 if(strcmp(elems[i], "dns") == 0){
550 qid.type = QTFILE;
551 qid.path = Qdns;
552 goto Found;
554 err = "file does not exist";
555 break;
559 send:
560 if(nmf != nil && (err!=nil || job->reply.nwqid<nelems))
561 freefid(nmf);
562 if(err == nil)
563 mf->qid = qid;
564 sendmsg(job, err);
565 return err;
568 void
569 ropen(Job *job, Mfile *mf)
571 int mode;
572 char *err;
574 err = 0;
575 mode = job->request.mode;
576 if(mf->qid.type & QTDIR){
577 if(mode)
578 err = "permission denied";
580 job->reply.qid = mf->qid;
581 job->reply.iounit = 0;
582 sendmsg(job, err);
585 void
586 rcreate(Job *job, Mfile *mf)
588 USED(mf);
589 sendmsg(job, "creation permission denied");
592 void
593 rread(Job *job, Mfile *mf)
595 int i, n, cnt;
596 long off;
597 Dir dir;
598 uchar buf[Maxfdata];
599 char *err;
600 long clock;
602 n = 0;
603 err = 0;
604 off = job->request.offset;
605 cnt = job->request.count;
606 if(mf->qid.type & QTDIR){
607 clock = time(0);
608 if(off == 0){
609 dir.name = "dns";
610 dir.qid.type = QTFILE;
611 dir.qid.vers = vers;
612 dir.qid.path = Qdns;
613 dir.mode = 0666;
614 dir.length = 0;
615 dir.uid = mf->user;
616 dir.gid = mf->user;
617 dir.muid = mf->user;
618 dir.atime = clock; /* wrong */
619 dir.mtime = clock; /* wrong */
620 n = convD2M(&dir, buf, sizeof buf);
622 job->reply.data = (char*)buf;
623 } else {
624 for(i = 1; i <= mf->nrr; i++)
625 if(mf->rr[i] > off)
626 break;
627 if(i > mf->nrr)
628 goto send;
629 if(off + cnt > mf->rr[i])
630 n = mf->rr[i] - off;
631 else
632 n = cnt;
633 job->reply.data = mf->reply + off;
635 send:
636 job->reply.count = n;
637 sendmsg(job, err);
640 void
641 rwrite(Job *job, Mfile *mf, Request *req)
643 int cnt, rooted, status;
644 long n;
645 char *err, *p, *atype;
646 RR *rp, *tp, *neg;
647 int wantsav;
648 static char *dumpfile;
650 err = 0;
651 cnt = job->request.count;
652 if(mf->qid.type & QTDIR){
653 err = "can't write directory";
654 goto send;
656 if(cnt >= Maxrequest){
657 err = "request too long";
658 goto send;
660 job->request.data[cnt] = 0;
661 if(cnt > 0 && job->request.data[cnt-1] == '\n')
662 job->request.data[cnt-1] = 0;
664 /*
665 * special commands
666 */
667 p = job->request.data;
668 if(strcmp(p, "debug")==0){
669 debug ^= 1;
670 goto send;
671 } else if(strcmp(p, "dump")==0){
672 if(dumpfile == nil)
673 dumpfile = unsharp("#9/ndb/dnsdump");
674 dndump(dumpfile);
675 goto send;
676 } else if(strncmp(p, "dump ", 5) == 0){
677 if(*(p+5))
678 dndump(p+5);
679 else
680 err = "bad filename";
681 goto send;
682 } else if(strcmp(p, "refresh")==0){
683 needrefresh = 1;
684 goto send;
687 /*
688 * kill previous reply
689 */
690 mf->nrr = 0;
691 mf->rr[0] = 0;
693 /*
694 * break up request (into a name and a type)
695 */
696 atype = strchr(job->request.data, ' ');
697 if(atype == 0){
698 err = "illegal request";
699 goto send;
700 } else
701 *atype++ = 0;
703 /*
704 * tracing request
705 */
706 if(strcmp(atype, "trace") == 0){
707 if(trace)
708 free(trace);
709 if(*job->request.data)
710 trace = estrdup(job->request.data);
711 else
712 trace = 0;
713 goto send;
716 mf->type = rrtype(atype);
717 if(mf->type < 0){
718 err = "unknown type";
719 goto send;
722 p = atype - 2;
723 if(p >= job->request.data && *p == '.'){
724 rooted = 1;
725 *p = 0;
726 } else
727 rooted = 0;
729 p = job->request.data;
730 if(*p == '!'){
731 wantsav = 1;
732 p++;
733 } else
734 wantsav = 0;
735 dncheck(0, 1);
736 rp = dnresolve(p, Cin, mf->type, req, 0, 0, Recurse, rooted, &status);
737 dncheck(0, 1);
738 neg = rrremneg(&rp);
739 if(neg){
740 status = neg->negrcode;
741 rrfreelist(neg);
743 if(rp == 0){
744 switch(status){
745 case Rname:
746 err = "name does not exist";
747 break;
748 case Rserver:
749 err = "dns failure";
750 break;
751 default:
752 err = "resource does not exist";
753 break;
755 } else {
756 lock(&joblock);
757 if(!job->flushed){
758 /* format data to be read later */
759 n = 0;
760 mf->nrr = 0;
761 for(tp = rp; mf->nrr < Maxrrr-1 && n < Maxreply && tp &&
762 tsame(mf->type, tp->type); tp = tp->next){
763 mf->rr[mf->nrr++] = n;
764 if(wantsav)
765 n += snprint(mf->reply+n, Maxreply-n, "%Q", tp);
766 else
767 n += snprint(mf->reply+n, Maxreply-n, "%R", tp);
769 mf->rr[mf->nrr] = n;
771 unlock(&joblock);
772 rrfreelist(rp);
775 send:
776 dncheck(0, 1);
777 job->reply.count = cnt;
778 sendmsg(job, err);
781 void
782 rclunk(Job *job, Mfile *mf)
784 freefid(mf);
785 sendmsg(job, 0);
788 void
789 rremove(Job *job, Mfile *mf)
791 USED(mf);
792 sendmsg(job, "remove permission denied");
795 void
796 rstat(Job *job, Mfile *mf)
798 Dir dir;
799 uchar buf[IOHDRSZ+Maxfdata];
801 if(mf->qid.type & QTDIR){
802 dir.name = ".";
803 dir.mode = DMDIR|0555;
804 } else {
805 dir.name = "dns";
806 dir.mode = 0666;
808 dir.qid = mf->qid;
809 dir.length = 0;
810 dir.uid = mf->user;
811 dir.gid = mf->user;
812 dir.muid = mf->user;
813 dir.atime = dir.mtime = time(0);
814 job->reply.nstat = convD2M(&dir, buf, sizeof buf);
815 job->reply.stat = buf;
816 sendmsg(job, 0);
819 void
820 rwstat(Job *job, Mfile *mf)
822 USED(mf);
823 sendmsg(job, "wstat permission denied");
826 void
827 sendmsg(Job *job, char *err)
829 int n;
830 uchar mdata[IOHDRSZ + Maxfdata];
831 char ename[ERRMAX];
833 if(err){
834 job->reply.type = Rerror;
835 snprint(ename, sizeof(ename), "dns: %s", err);
836 job->reply.ename = ename;
837 }else{
838 job->reply.type = job->request.type+1;
840 job->reply.tag = job->request.tag;
841 n = convS2M(&job->reply, mdata, sizeof mdata);
842 if(n == 0){
843 syslog(1, logfile, "sendmsg convS2M of %F returns 0", &job->reply);
844 abort();
846 lock(&joblock);
847 if(job->flushed == 0)
848 if(write(mfd[1], mdata, n)!=n)
849 sysfatal("mount write");
850 unlock(&joblock);
851 if(debug)
852 syslog(0, logfile, "%F %d", &job->reply, n);
855 /*
856 * the following varies between dnsdebug and dns
857 */
858 void
859 logreply(int id, uchar *addr, DNSmsg *mp)
861 RR *rp;
863 syslog(0, LOG, "%d: rcvd %I flags:%s%s%s%s%s", id, addr,
864 mp->flags & Fauth ? " auth" : "",
865 mp->flags & Ftrunc ? " trunc" : "",
866 mp->flags & Frecurse ? " rd" : "",
867 mp->flags & Fcanrec ? " ra" : "",
868 mp->flags & (Fauth|Rname) == (Fauth|Rname) ?
869 " nx" : "");
870 for(rp = mp->qd; rp != nil; rp = rp->next)
871 syslog(0, LOG, "%d: rcvd %I qd %s", id, addr, rp->owner->name);
872 for(rp = mp->an; rp != nil; rp = rp->next)
873 syslog(0, LOG, "%d: rcvd %I an %R", id, addr, rp);
874 for(rp = mp->ns; rp != nil; rp = rp->next)
875 syslog(0, LOG, "%d: rcvd %I ns %R", id, addr, rp);
876 for(rp = mp->ar; rp != nil; rp = rp->next)
877 syslog(0, LOG, "%d: rcvd %I ar %R", id, addr, rp);
880 void
881 logsend(int id, int subid, uchar *addr, char *sname, char *rname, int type)
883 char buf[12];
885 syslog(0, LOG, "%d.%d: sending to %I/%s %s %s",
886 id, subid, addr, sname, rname, rrname(type, buf, sizeof buf));
889 RR*
890 getdnsservers(int class)
892 return dnsservers(class);