12 #include <arpa/nameser.h>
13 #include <sys/socket.h>
14 #include <netinet/in.h>
15 #include <arpa/inet.h>
17 #include "adns-internal.h"
19 #define LIST_UNLINK(list,node) \
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; \
27 #define LIST_LINK_TAIL(list,node) \
30 (node)->next= (list).tail; \
31 if ((list).tail) (list).tail->back= (node); else (list).head= (node); \
32 (list).tail= (node); \
35 static 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);
42 static void debug(adns_state ads, const char *fmt, ...) {
50 static 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);
57 static void diag(adns_state ads, const char *fmt, ...) {
65 static void addserver(adns_state ads, struct in_addr addr) {
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));
76 if (ads->nservers>=MAXSERVERS) {
77 diag(ads,"too many nameservers, ignoring %s",inet_ntoa(addr));
81 ss= ads->servers+ads->nservers;
83 ss->state= server_disc;
84 ss->connw.head= ss->connw.tail= 0;
88 static void configparseerr(adns_state ads, const char *fn, int lno,
89 const char *fmt, ...) {
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);
96 vfprintf(stderr,fmt,al);
101 static void ccf_nameserver(adns_state ads, const char *fn, int lno, const char *buf) {
104 if (!inet_aton(buf,&ia)) {
105 configparseerr(ads,fn,lno,"invalid nameserver address `%s'",buf);
108 debug(ads,"using nameserver %s",inet_ntoa(ia));
112 static void ccf_search(adns_state ads, const char *fn, int lno, const char *buf) {
114 diag(ads,"warning - `search' ignored FIXME");
117 static void ccf_sortlist(adns_state ads, const char *fn, int lno, const char *buf) {
118 diag(ads,"warning - `sortlist' ignored FIXME");
121 static void ccf_options(adns_state ads, const char *fn, int lno, const char *buf) {
123 diag(ads,"warning - `options' ignored FIXME");
126 static void ccf_clearnss(adns_state ads, const char *fn, int lno, const char *buf) {
130 static const struct configcommandinfo {
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 },
143 static int ctype_whitespace(int c) { return c==' ' || c=='\n' || c=='\t'; }
144 static int ctype_digit(int c) { return c>='0' && c<='9'; }
146 static void readconfig(adns_state ads, const char *filename) {
147 char linebuf[2000], *p, *q;
150 const struct configcommandinfo *ccip;
152 file= fopen(filename,"r");
154 if (errno == ENOENT) {
155 debug(ads,"configuration file `%s' does not exist",filename);
158 diag(ads,"cannot open configuration file `%s': %s",filename,strerror(errno));
162 for (lno=1; fgets(linebuf,sizeof(linebuf),file); lno++) {
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') { }
171 while (l>0 && ctype_whitespace(linebuf[l-1])) l--;
174 while (ctype_whitespace(*p)) p++;
175 if (*p == '#' || *p == '\n') continue;
177 while (*q && !ctype_whitespace(*q)) q++;
178 for (ccip=configcommandinfos;
179 ccip->name && strncmp(ccip->name,p,q-p);
182 diag(ads,"%s:%d: unknown configuration directive `%.*s'",filename,lno,q-p,p);
185 while (ctype_whitespace(*q)) q++;
186 ccip->fn(ads,filename,lno,q);
189 diag(ads,"%s:%d: read error: %s",filename,lno,strerror(errno));
194 static const char *instrum_getenv(adns_state ads, const char *envvar) {
197 value= getenv(envvar);
198 if (!value) debug(ads,"environment variable %s not set",envvar);
199 else debug(ads,"environment variable %s set to `%s'",envvar,value);
203 static void readconfigenv(adns_state ads, const char *envvar) {
204 const char *filename;
206 if (ads->iflags & adns_if_noenv) {
207 debug(ads,"not checking environment variable `%s'",envvar);
210 filename= instrum_getenv(ads,envvar);
211 if (filename) readconfig(ads,filename);
214 int adns_init(adns_state *ads_r, adns_initflags flags) {
216 const char *res_options, *adns_res_options;
217 struct protoent *proto;
220 ads= malloc(sizeof(*ads)); if (!ads) return errno;
221 ads->tosend.head= ads->tosend.tail= 0;
222 ads->timew.head= ads->timew.tail= 0;
223 ads->childw.head= ads->childw.tail= 0;
224 ads->output.head= ads->output.tail= 0;
229 ads->tcpbufavail= ads->tcpbufused= ads->tcpbufdone= 0;
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);
240 readconfig(ads,"/etc/resolv.conf");
241 readconfigenv(ads,"RES_CONF");
242 readconfigenv(ads,"ADNS_RES_CONF");
244 ccf_options(ads,"RES_OPTIONS",-1,res_options);
245 ccf_options(ads,"ADNS_RES_OPTIONS",-1,adns_res_options);
247 ccf_search(ads,"LOCALDOMAIN",-1,instrum_getenv(ads,"LOCALDOMAIN"));
248 ccf_search(ads,"ADNS_LOCALDOMAIN",-1,instrum_getenv(ads,"ADNS_LOCALDOMAIN"));
250 if (!ads->nservers) {
252 if (ads->iflags & adns_if_debug)
253 fprintf(stderr,"adns: no nameservers, using localhost\n");
254 ia.s_addr= INADDR_LOOPBACK;
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; }
266 close(ads->udpsocket);
272 static void query_fail(adns_state ads, adns_query qu, adns_status stat) {
276 if (!ans) ans= malloc(sizeof(*qu->answer));
285 LIST_LINK_TAIL(ads->output,qu);
288 int adns_finish(adns_state ads) {
292 void adns_interest(adns_state ads, int *maxfd,
293 fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
294 struct timeval **tv_io, struct timeval *tvbuf) {
298 static void autosys(adns_state ads) {
299 if (ads->iflags & adns_if_noautosys) return;
300 adns_callback(ads,-1,0,0,0);
303 void adns_cancel(adns_state ads, adns_query query) {
307 int adns_callback(adns_state ads, int maxfd,
308 const fd_set *readfds, const fd_set *writefds,
309 const fd_set *exceptfds) {
313 static int internal_check(adns_state ads,
314 adns_query *query_io,
315 adns_answer **answer,
321 if (!ads->output.head) return EWOULDBLOCK;
322 qu= ads->output.head;
324 if (qu->id>=0) return EWOULDBLOCK;
326 LIST_UNLINK(ads->output,qu);
328 if (context_r) *context_r= qu->context;
333 int adns_wait(adns_state ads,
334 adns_query *query_io,
335 adns_answer **answer_r,
337 int r, maxfd, rsel, rcb;
338 fd_set readfds, writefds, exceptfds;
339 struct timeval tvbuf, *tvp;
342 r= internal_check(ads,query_io,answer_r,context_r);
343 if (r && r != EWOULDBLOCK) return r;
344 FD_ZERO(&readfds); FD_ZERO(&writefds); FD_ZERO(&exceptfds);
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);
354 int adns_check(adns_state ads,
355 adns_query *query_io,
356 adns_answer **answer_r,
359 return internal_check(ads,query_io,answer_r,context_r);
362 int adns_synchronous(adns_state ads,
365 adns_queryflags flags,
366 adns_answer **answer_r) {
370 r= adns_submit(ads,owner,type,flags,0,&qu);
374 r= adns_wait(ads,&qu,answer_r,0);
376 if (r) adns_cancel(ads,qu);
380 static 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;
386 #define MKQUERY_ADDB(b) *nqbuf++= (b)
387 #define MKQUERY_ADDW(w) (MKQUERY_ADDB(((w)>>8)&0x0ff), MKQUERY_ADDB((w)&0x0ff))
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;
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;
406 if (!*p) return adns_s_invaliddomain;
409 while (p!=pe && (c= *p++)!='.') {
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;
417 return adns_s_invaliddomain;
419 } else if (!(c= *p++)) {
420 return adns_s_invaliddomain;
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;
430 if (ll == sizeof(label)) return adns_s_invaliddomain;
433 if (!ll) return adns_s_invaliddomain;
434 if (nlabs++ > 63) return adns_s_invaliddomain;
436 memcpy(nqbuf,label,ll); nqbuf+= ll;
440 MKQUERY_ADDW(type & adns__rrt_typemask); /* QTYPE */
441 MKQUERY_ADDW(1); /* QCLASS=IN */
443 *qml_r= nqbuf - ads->qbuf;
448 static 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) {
454 qu= malloc(sizeof(*qu)+ol+1+qml); if (!qu) return 0;
455 qu->next= qu->back= qu->parent= qu->child= 0;
460 qu->context= context;
462 qu->sentudp= qu->senttcp= 0;
464 memcpy(qu->owner,owner,ol); qu->owner[ol]= 0;
465 qu->querymsg= qm= qu->owner+ol+1;
466 memcpy(qm,ads->qbuf,qml);
471 static int failsubmit(adns_state ads, void *context, adns_query *query_r,
472 adns_rrtype type, adns_queryflags flags,
473 int id, adns_status stat) {
476 qu= allocquery(ads,0,0,0,id,type,flags,context); if (!qu) return errno;
477 query_fail(ads,qu,stat);
482 static 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));
492 int adns_submit(adns_state ads,
495 adns_queryflags flags,
497 adns_query *query_r) {
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--; }
509 stat= mkquery(ads,owner,ol,id,type,flags,&qml);
510 if (stat) return failsubmit(ads,context,query_r,type,flags,id,stat);
512 qu= allocquery(ads,owner,ol,qml,id,type,flags,context); if (!qu) return errno;
514 LIST_LINK_TAIL(ads->tosend,qu);