Sends packet, is apparently OK (tcpdump shows response is OK).
[adns] / src / adns.c
CommitLineData
a17d3a1d 1/**/
2
964344fc 3#include <stdarg.h>
4#include <stdio.h>
5#include <errno.h>
6#include <string.h>
7#include <stdlib.h>
e8c505a5 8#include <assert.h>
80917fcc 9#include <unistd.h>
964344fc 10
80917fcc 11#include <netdb.h>
a17d3a1d 12#include <arpa/nameser.h>
964344fc 13#include <sys/socket.h>
14#include <netinet/in.h>
15#include <arpa/inet.h>
a17d3a1d 16
17#include "adns-internal.h"
18
19#define LIST_UNLINK(list,node) \
20 do { \
21 if ((node)->back) (node)->back->next= (node)->next; \
22 else (list).head= (node)->next; \
23 if ((node)->next) (node)->next->back= (node)->back; \
24 else (list).tail= (node)->back; \
25 } while(0)
26
27#define LIST_LINK_TAIL(list,node) \
28 do { \
29 (node)->back= 0; \
30 (node)->next= (list).tail; \
964344fc 31 if ((list).tail) (list).tail->back= (node); else (list).head= (node); \
a17d3a1d 32 (list).tail= (node); \
33 } while(0)
34
964344fc 35static void vdebug(adns_state ads, const char *fmt, va_list al) {
36 if (!(ads->iflags & adns_if_debug)) return;
37 fputs("adns debug: ",stderr);
38 vfprintf(stderr,fmt,al);
39 fputc('\n',stderr);
40}
41
42static void debug(adns_state ads, const char *fmt, ...) {
43 va_list al;
44
45 va_start(al,fmt);
46 vdebug(ads,fmt,al);
47 va_end(al);
48}
49
50static void vdiag(adns_state ads, const char *fmt, va_list al) {
51 if (ads->iflags & adns_if_noerrprint) return;
52 fputs("adns: ",stderr);
53 vfprintf(stderr,fmt,al);
54 fputc('\n',stderr);
55}
56
57static void diag(adns_state ads, const char *fmt, ...) {
58 va_list al;
59
60 va_start(al,fmt);
61 vdiag(ads,fmt,al);
62 va_end(al);
63}
64
65static void addserver(adns_state ads, struct in_addr addr) {
e8c505a5 66 int i;
80917fcc 67 struct server *ss;
e8c505a5 68
69 for (i=0; i<ads->nservers; i++) {
70 if (ads->servers[i].addr.s_addr == addr.s_addr) {
71 debug(ads,"duplicate nameserver %s ignored",inet_ntoa(addr));
72 return;
73 }
74 }
75
a17d3a1d 76 if (ads->nservers>=MAXSERVERS) {
964344fc 77 diag(ads,"too many nameservers, ignoring %s",inet_ntoa(addr));
e8c505a5 78 return;
a17d3a1d 79 }
e8c505a5 80
80917fcc 81 ss= ads->servers+ads->nservers;
82 ss->addr= addr;
83 ss->state= server_disc;
84 ss->connw.head= ss->connw.tail= 0;
e8c505a5 85 ads->nservers++;
a17d3a1d 86}
87
964344fc 88static void configparseerr(adns_state ads, const char *fn, int lno,
89 const char *fmt, ...) {
90 va_list al;
91
92 if (ads->iflags & adns_if_noerrprint) return;
93 if (lno==-1) fprintf(stderr,"adns: %s: ",fn);
94 else fprintf(stderr,"adns: %s:%d: ",fn,lno);
95 va_start(al,fmt);
96 vfprintf(stderr,fmt,al);
97 va_end(al);
98 fputc('\n',stderr);
99}
100
101static void ccf_nameserver(adns_state ads, const char *fn, int lno, const char *buf) {
102 struct in_addr ia;
103
104 if (!inet_aton(buf,&ia)) {
105 configparseerr(ads,fn,lno,"invalid nameserver address `%s'",buf);
106 return;
107 }
108 debug(ads,"using nameserver %s",inet_ntoa(ia));
109 addserver(ads,ia);
110}
111
112static void ccf_search(adns_state ads, const char *fn, int lno, const char *buf) {
113 if (!buf) return;
114 diag(ads,"warning - `search' ignored FIXME");
115}
116
117static void ccf_sortlist(adns_state ads, const char *fn, int lno, const char *buf) {
118 diag(ads,"warning - `sortlist' ignored FIXME");
119}
120
121static void ccf_options(adns_state ads, const char *fn, int lno, const char *buf) {
122 if (!buf) return;
123 diag(ads,"warning - `options' ignored FIXME");
124}
125
126static void ccf_clearnss(adns_state ads, const char *fn, int lno, const char *buf) {
127 ads->nservers= 0;
128}
129
130static const struct configcommandinfo {
131 const char *name;
132 void (*fn)(adns_state ads, const char *fn, int lno, const char *buf);
133} configcommandinfos[]= {
134 { "nameserver", ccf_nameserver },
135 { "domain", ccf_search },
136 { "search", ccf_search },
137 { "sortlist", ccf_sortlist },
138 { "options", ccf_options },
139 { "clearnameservers", ccf_clearnss },
140 { 0 }
141};
142
350d37d9 143static int ctype_whitespace(int c) { return c==' ' || c=='\n' || c=='\t'; }
144static int ctype_digit(int c) { return c>='0' && c<='9'; }
964344fc 145
146static void readconfig(adns_state ads, const char *filename) {
147 char linebuf[2000], *p, *q;
148 FILE *file;
149 int lno, l, c;
150 const struct configcommandinfo *ccip;
151
152 file= fopen(filename,"r");
153 if (!file) {
154 if (errno == ENOENT) {
155 debug(ads,"configuration file `%s' does not exist",filename);
156 return;
157 }
158 diag(ads,"cannot open configuration file `%s': %s",filename,strerror(errno));
159 return;
160 }
161
162 for (lno=1; fgets(linebuf,sizeof(linebuf),file); lno++) {
163 l= strlen(linebuf);
164 if (!l) continue;
165 if (linebuf[l-1] != '\n' && !feof(file)) {
166 diag(ads,"%s:%d: line too long",filename,lno);
167 while ((c= getc(file)) != EOF && c != '\n') { }
168 if (c == EOF) break;
169 continue;
170 }
350d37d9 171 while (l>0 && ctype_whitespace(linebuf[l-1])) l--;
964344fc 172 linebuf[l]= 0;
173 p= linebuf;
350d37d9 174 while (ctype_whitespace(*p)) p++;
964344fc 175 if (*p == '#' || *p == '\n') continue;
176 q= p;
350d37d9 177 while (*q && !ctype_whitespace(*q)) q++;
964344fc 178 for (ccip=configcommandinfos;
179 ccip->name && strncmp(ccip->name,p,q-p);
180 ccip++);
181 if (!ccip->name) {
182 diag(ads,"%s:%d: unknown configuration directive `%.*s'",filename,lno,q-p,p);
183 continue;
184 }
350d37d9 185 while (ctype_whitespace(*q)) q++;
964344fc 186 ccip->fn(ads,filename,lno,q);
187 }
188 if (ferror(file)) {
189 diag(ads,"%s:%d: read error: %s",filename,lno,strerror(errno));
190 }
191 fclose(file);
192}
193
194static const char *instrum_getenv(adns_state ads, const char *envvar) {
195 const char *value;
196
197 value= getenv(envvar);
e8c505a5 198 if (!value) debug(ads,"environment variable %s not set",envvar);
199 else debug(ads,"environment variable %s set to `%s'",envvar,value);
964344fc 200 return value;
a17d3a1d 201}
202
964344fc 203static void readconfigenv(adns_state ads, const char *envvar) {
a17d3a1d 204 const char *filename;
205
964344fc 206 if (ads->iflags & adns_if_noenv) {
207 debug(ads,"not checking environment variable `%s'",envvar);
208 return;
209 }
210 filename= instrum_getenv(ads,envvar);
211 if (filename) readconfig(ads,filename);
a17d3a1d 212}
213
964344fc 214int adns_init(adns_state *ads_r, adns_initflags flags) {
a17d3a1d 215 adns_state ads;
964344fc 216 const char *res_options, *adns_res_options;
80917fcc 217 struct protoent *proto;
350d37d9 218 int r;
a17d3a1d 219
220 ads= malloc(sizeof(*ads)); if (!ads) return errno;
9d95094c 221 ads->tosend.head= ads->tosend.tail= 0;
a17d3a1d 222 ads->timew.head= ads->timew.tail= 0;
964344fc 223 ads->childw.head= ads->childw.tail= 0;
224 ads->output.head= ads->output.tail= 0;
80917fcc 225 ads->nextid= 0x311f;
a17d3a1d 226 ads->udpsocket= -1;
227 ads->qbufavail= 0;
228 ads->qbuf= 0;
229 ads->tcpbufavail= ads->tcpbufused= ads->tcpbufdone= 0;
230 ads->tcpbuf= 0;
964344fc 231 ads->iflags= flags;
a17d3a1d 232 ads->nservers= 0;
964344fc 233 ads->iflags= flags;
234
235 res_options= instrum_getenv(ads,"RES_OPTIONS");
236 adns_res_options= instrum_getenv(ads,"ADNS_RES_OPTIONS");
237 ccf_options(ads,"RES_OPTIONS",-1,res_options);
238 ccf_options(ads,"ADNS_RES_OPTIONS",-1,adns_res_options);
a17d3a1d 239
240 readconfig(ads,"/etc/resolv.conf");
241 readconfigenv(ads,"RES_CONF");
242 readconfigenv(ads,"ADNS_RES_CONF");
964344fc 243
244 ccf_options(ads,"RES_OPTIONS",-1,res_options);
245 ccf_options(ads,"ADNS_RES_OPTIONS",-1,adns_res_options);
246
247 ccf_search(ads,"LOCALDOMAIN",-1,instrum_getenv(ads,"LOCALDOMAIN"));
248 ccf_search(ads,"ADNS_LOCALDOMAIN",-1,instrum_getenv(ads,"ADNS_LOCALDOMAIN"));
249
a17d3a1d 250 if (!ads->nservers) {
964344fc 251 struct in_addr ia;
252 if (ads->iflags & adns_if_debug)
a17d3a1d 253 fprintf(stderr,"adns: no nameservers, using localhost\n");
964344fc 254 ia.s_addr= INADDR_LOOPBACK;
255 addserver(ads,ia);
a17d3a1d 256 }
80917fcc 257
258 proto= getprotobyname("udp"); if (!proto) { r= ENOPROTOOPT; goto x_free; }
259 ads->udpsocket= socket(AF_INET,SOCK_DGRAM,proto->p_proto);
260 if (!ads->udpsocket) { r= errno; goto x_closeudp; }
a17d3a1d 261
262 *ads_r= ads;
263 return 0;
80917fcc 264
265 x_closeudp:
266 close(ads->udpsocket);
267 x_free:
268 free(ads);
269 return r;
a17d3a1d 270}
271
964344fc 272static void query_fail(adns_state ads, adns_query qu, adns_status stat) {
e8c505a5 273 adns_answer *ans;
a17d3a1d 274
275 ans= qu->answer;
276 if (!ans) ans= malloc(sizeof(*qu->answer));
277 if (ans) {
278 ans->status= stat;
279 ans->cname= 0;
280 ans->type= qu->type;
281 ans->nrrs= 0;
282 }
283 qu->answer= ans;
9d95094c 284 qu->id= -1;
285 LIST_LINK_TAIL(ads->output,qu);
a17d3a1d 286}
287
80917fcc 288int adns_finish(adns_state ads) {
289 abort(); /* FIXME */
290}
291
e8c505a5 292void adns_interest(adns_state ads, int *maxfd,
964344fc 293 fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
e8c505a5 294 struct timeval **tv_io, struct timeval *tvbuf) {
964344fc 295 abort(); /* FIXME */
a17d3a1d 296}
297
e8c505a5 298static void autosys(adns_state ads) {
299 if (ads->iflags & adns_if_noautosys) return;
300 adns_callback(ads,-1,0,0,0);
301}
302
303void adns_cancel(adns_state ads, adns_query query) {
304 abort(); /* FIXME */
305}
306
307int adns_callback(adns_state ads, int maxfd,
308 const fd_set *readfds, const fd_set *writefds,
309 const fd_set *exceptfds) {
310 abort(); /* FIXME */
311}
312
313static int internal_check(adns_state ads,
314 adns_query *query_io,
9d95094c 315 adns_answer **answer,
316 void **context_r) {
317 adns_query qu;
318
319 qu= *query_io;
320 if (!qu) {
321 if (!ads->output.head) return EWOULDBLOCK;
322 qu= ads->output.head;
323 } else {
324 if (qu->id>=0) return EWOULDBLOCK;
325 }
326 LIST_UNLINK(ads->output,qu);
327 *answer= qu->answer;
328 if (context_r) *context_r= qu->context;
329 free(qu);
330 return 0;
e8c505a5 331}
332
333int adns_wait(adns_state ads,
334 adns_query *query_io,
9d95094c 335 adns_answer **answer_r,
336 void **context_r) {
e8c505a5 337 int r, maxfd, rsel, rcb;
338 fd_set readfds, writefds, exceptfds;
339 struct timeval tvbuf, *tvp;
340
341 for (;;) {
9d95094c 342 r= internal_check(ads,query_io,answer_r,context_r);
e8c505a5 343 if (r && r != EWOULDBLOCK) return r;
344 FD_ZERO(&readfds); FD_ZERO(&writefds); FD_ZERO(&exceptfds);
345 maxfd= 0; tvp= 0;
346 adns_interest(ads,&maxfd,&readfds,&writefds,&exceptfds,&tvp,&tvbuf);
347 rsel= select(maxfd,&readfds,&writefds,&exceptfds,tvp);
348 if (rsel==-1) return r;
349 rcb= adns_callback(ads,maxfd,&readfds,&writefds,&exceptfds);
350 assert(rcb==rsel);
351 }
352}
353
354int adns_check(adns_state ads,
355 adns_query *query_io,
9d95094c 356 adns_answer **answer_r,
357 void **context_r) {
e8c505a5 358 autosys(ads);
9d95094c 359 return internal_check(ads,query_io,answer_r,context_r);
e8c505a5 360}
361
362int adns_synchronous(adns_state ads,
363 const char *owner,
364 adns_rrtype type,
72934832 365 adns_queryflags flags,
9d95094c 366 adns_answer **answer_r) {
e8c505a5 367 adns_query qu;
368 int r;
369
370 r= adns_submit(ads,owner,type,flags,0,&qu);
371 if (r) return r;
372
72934832 373 do {
9d95094c 374 r= adns_wait(ads,&qu,answer_r,0);
72934832 375 } while (r==EINTR);
e8c505a5 376 if (r) adns_cancel(ads,qu);
377 return r;
378}
379
350d37d9 380static adns_status mkquery(adns_state ads, const char *owner, int ol, int id,
381 adns_rrtype type, adns_queryflags flags, int *qml_r) {
382 int ll, c, nlabs, qbufreq;
383 unsigned char label[255], *nqbuf;
384 const char *p, *pe;
385
386#define MKQUERY_ADDB(b) *nqbuf++= (b)
387#define MKQUERY_ADDW(w) (MKQUERY_ADDB(((w)>>8)&0x0ff), MKQUERY_ADDB((w)&0x0ff))
388
389 qbufreq= 12+strlen(owner)+3;
390 if (ads->qbufavail < qbufreq) {
391 nqbuf= realloc(ads->qbuf,qbufreq);
392 if (!nqbuf) return adns_s_nolocalmem;
393 ads->qbuf= nqbuf; ads->qbufavail= qbufreq;
394 }
395 nqbuf= ads->qbuf;
396
397 MKQUERY_ADDW(id);
398 MKQUERY_ADDB(0x01); /* QR=Q(0), OPCODE=QUERY(0000), !AA, !TC, RD */
399 MKQUERY_ADDB(0x00); /* !RA, Z=000, RCODE=NOERROR(0000) */
400 MKQUERY_ADDW(1); /* QDCOUNT=1 */
401 MKQUERY_ADDW(0); /* ANCOUNT=0 */
402 MKQUERY_ADDW(0); /* NSCOUNT=0 */
403 MKQUERY_ADDW(0); /* ARCOUNT=0 */
404 p= owner; pe= owner+ol;
405 nlabs= 0;
406 if (!*p) return adns_s_invaliddomain;
407 do {
408 ll= 0;
409 while (p!=pe && (c= *p++)!='.') {
410 if (c=='\\') {
411 if (!(flags & adns_f_anyquote)) return adns_s_invaliddomain;
412 if (ctype_digit(p[0])) {
413 if (ctype_digit(p[1]) && ctype_digit(p[2])) {
414 c= (*p++ - '0')*100 + (*p++ - '0')*10 + (*p++ - '0');
415 if (c >= 256) return adns_s_invaliddomain;
416 } else {
417 return adns_s_invaliddomain;
418 }
419 } else if (!(c= *p++)) {
420 return adns_s_invaliddomain;
421 }
422 }
423 if (!(flags & adns_f_anyquote)) {
424 if ((c >= '0' && c <= '9') || c == '-') {
425 if (!ll) return adns_s_invaliddomain;
426 } else if ((c < 'a' || c > 'z') && (c < 'A' && c > 'Z')) {
427 return adns_s_invaliddomain;
428 }
429 }
430 if (ll == sizeof(label)) return adns_s_invaliddomain;
431 label[ll++]= c;
432 }
433 if (!ll) return adns_s_invaliddomain;
434 if (nlabs++ > 63) return adns_s_invaliddomain;
435 MKQUERY_ADDB(ll);
436 memcpy(nqbuf,label,ll); nqbuf+= ll;
437 } while (p!=pe);
438
439 MKQUERY_ADDB(0);
440 MKQUERY_ADDW(type & adns__rrt_typemask); /* QTYPE */
441 MKQUERY_ADDW(1); /* QCLASS=IN */
442
443 *qml_r= nqbuf - ads->qbuf;
444
445 return adns_s_ok;
80917fcc 446}
447
350d37d9 448static adns_query allocquery(adns_state ads, const char *owner, int ol,
449 int qml, int id, adns_rrtype type,
450 adns_queryflags flags, void *context) {
a17d3a1d 451 adns_query qu;
350d37d9 452 unsigned char *qm;
453
454 qu= malloc(sizeof(*qu)+ol+1+qml); if (!qu) return 0;
a17d3a1d 455 qu->next= qu->back= qu->parent= qu->child= 0;
350d37d9 456 qu->id= id;
a17d3a1d 457 qu->type= type;
458 qu->answer= 0;
459 qu->flags= flags;
460 qu->context= context;
964344fc 461 qu->udpretries= 0;
80917fcc 462 qu->sentudp= qu->senttcp= 0;
463 qu->nextserver= 0;
a17d3a1d 464 memcpy(qu->owner,owner,ol); qu->owner[ol]= 0;
350d37d9 465 qu->querymsg= qm= qu->owner+ol+1;
466 memcpy(qm,ads->qbuf,qml);
467 qu->querylen= qml;
468 return qu;
469}
80917fcc 470
350d37d9 471static int failsubmit(adns_state ads, void *context, adns_query *query_r,
472 adns_rrtype type, adns_queryflags flags,
473 int id, adns_status stat) {
474 adns_query qu;
80917fcc 475
350d37d9 476 qu= allocquery(ads,0,0,0,id,type,flags,context); if (!qu) return errno;
477 query_fail(ads,qu,stat);
478 *query_r= qu;
479 return 0;
480}
481
9d95094c 482static void trysendudp(adns_state ads, adns_query qu) {
483 struct sockaddr_in servaddr;
484 /* FIXME: _f_usevc not implemented */
485 memset(&servaddr,0,sizeof(servaddr));
486 servaddr.sin_family= AF_INET;
487 servaddr.sin_addr= ads->servers[qu->nextserver].addr;
488 servaddr.sin_port= htons(53);
489 sendto(ads->udpsocket,qu->querymsg,qu->querylen,0,&servaddr,sizeof(servaddr));
490}
491
350d37d9 492int adns_submit(adns_state ads,
493 const char *owner,
494 adns_rrtype type,
495 adns_queryflags flags,
496 void *context,
497 adns_query *query_r) {
498 adns_query qu;
499 adns_status stat;
500 int ol, id, qml;
501
502 id= ads->nextid++;
503
504 ol= strlen(owner);
505 if (ol<=1 || ol>MAXDNAME+1)
506 return failsubmit(ads,context,query_r,type,flags,id,adns_s_invaliddomain);
507 if (owner[ol-1]=='.' && owner[ol-2]!='\\') { flags &= ~adns_f_search; ol--; }
508
509 stat= mkquery(ads,owner,ol,id,type,flags,&qml);
510 if (stat) return failsubmit(ads,context,query_r,type,flags,id,stat);
511
512 qu= allocquery(ads,owner,ol,qml,id,type,flags,context); if (!qu) return errno;
513
9d95094c 514 LIST_LINK_TAIL(ads->tosend,qu);
515 trysendudp(ads,qu);
350d37d9 516 autosys(ads);
80917fcc 517
a17d3a1d 518 *query_r= qu;
e8c505a5 519 return 0;
a17d3a1d 520}