2 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (c) 1996-1999 by Internet Software Consortium.
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
15 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 #if defined(LIBC_SCCS) && !defined(lint)
19 static const char rcsid[] = "$Id: dns_nw.c,v 1.9.18.3 2005/04/27 05:00:55 sra Exp $";
20 #endif /* LIBC_SCCS and not lint */
24 #include "port_before.h"
26 #include <sys/param.h>
27 #include <sys/socket.h>
29 #include <netinet/in.h>
30 #include <arpa/inet.h>
31 #include <arpa/nameser.h>
41 #include <isc/memcluster.h>
44 #include "port_after.h"
50 # define SPRINTF(x) strlen(sprintf/**/x)
52 # define SPRINTF(x) sprintf x
59 #define MAXPACKET (64*1024)
63 char * ali[MAXALIASES];
65 struct __res_state * res;
66 void (*free_res)(void *);
74 enum by_what { by_addr, by_name };
78 static void nw_close(struct irs_nw *);
79 static struct nwent * nw_byname(struct irs_nw *, const char *, int);
80 static struct nwent * nw_byaddr(struct irs_nw *, void *, int, int);
81 static struct nwent * nw_next(struct irs_nw *);
82 static void nw_rewind(struct irs_nw *);
83 static void nw_minimize(struct irs_nw *);
84 static struct __res_state * nw_res_get(struct irs_nw *this);
85 static void nw_res_set(struct irs_nw *this,
86 struct __res_state *res,
87 void (*free_res)(void *));
89 static struct nwent * get1101byaddr(struct irs_nw *, u_char *, int);
90 static struct nwent * get1101byname(struct irs_nw *, const char *);
91 static struct nwent * get1101answer(struct irs_nw *,
92 u_char *ansbuf, int anslen,
94 int af, const char *name,
95 const u_char *addr, int addrlen);
96 static struct nwent * get1101mask(struct irs_nw *this, struct nwent *);
97 static int make1101inaddr(const u_char *, int, char *, int);
98 static void normalize_name(char *name);
99 static int init(struct irs_nw *this);
104 irs_dns_nw(struct irs_acc *this) {
110 if (!(pvt = memget(sizeof *pvt))) {
114 memset(pvt, 0, sizeof *pvt);
115 if (!(nw = memget(sizeof *nw))) {
116 memput(pvt, sizeof *pvt);
120 memset(nw, 0x5e, sizeof *nw);
122 nw->close = nw_close;
123 nw->byname = nw_byname;
124 nw->byaddr = nw_byaddr;
126 nw->rewind = nw_rewind;
127 nw->minimize = nw_minimize;
128 nw->res_get = nw_res_get;
129 nw->res_set = nw_res_set;
136 nw_close(struct irs_nw *this) {
137 struct pvt *pvt = (struct pvt *)this->private;
141 if (pvt->res && pvt->free_res)
142 (*pvt->free_res)(pvt->res);
144 memput(pvt, sizeof *pvt);
145 memput(this, sizeof *this);
148 static struct nwent *
149 nw_byname(struct irs_nw *this, const char *name, int af) {
150 struct pvt *pvt = (struct pvt *)this->private;
152 if (init(this) == -1)
157 return (get1101byname(this, name));
161 RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
162 errno = EAFNOSUPPORT;
166 static struct nwent *
167 nw_byaddr(struct irs_nw *this, void *net, int len, int af) {
168 struct pvt *pvt = (struct pvt *)this->private;
170 if (init(this) == -1)
175 return (get1101byaddr(this, net, len));
179 RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
180 errno = EAFNOSUPPORT;
184 static struct nwent *
185 nw_next(struct irs_nw *this) {
193 nw_rewind(struct irs_nw *this) {
199 nw_minimize(struct irs_nw *this) {
200 struct pvt *pvt = (struct pvt *)this->private;
203 res_nclose(pvt->res);
206 static struct __res_state *
207 nw_res_get(struct irs_nw *this) {
208 struct pvt *pvt = (struct pvt *)this->private;
211 struct __res_state *res;
212 res = (struct __res_state *)malloc(sizeof *res);
217 memset(res, 0, sizeof *res);
218 nw_res_set(this, res, free);
225 nw_res_set(struct irs_nw *this, struct __res_state *res,
226 void (*free_res)(void *)) {
227 struct pvt *pvt = (struct pvt *)this->private;
229 if (pvt->res && pvt->free_res) {
230 res_nclose(pvt->res);
231 (*pvt->free_res)(pvt->res);
235 pvt->free_res = free_res;
240 static struct nwent *
241 get1101byname(struct irs_nw *this, const char *name) {
242 struct pvt *pvt = (struct pvt *)this->private;
245 struct nwent *result;
247 ansbuf = memget(MAXPACKET);
248 if (ansbuf == NULL) {
250 RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
253 anslen = res_nsearch(pvt->res, name, C_IN, T_PTR, ansbuf, MAXPACKET);
255 memput(ansbuf, MAXPACKET);
258 result = get1101mask(this, get1101answer(this, ansbuf, anslen, by_name,
259 AF_INET, name, NULL, 0));
260 memput(ansbuf, MAXPACKET);
264 static struct nwent *
265 get1101byaddr(struct irs_nw *this, u_char *net, int len) {
266 struct pvt *pvt = (struct pvt *)this->private;
267 char qbuf[sizeof "255.255.255.255.in-addr.arpa"];
268 struct nwent *result;
272 if (len < 1 || len > 32) {
274 RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
277 if (make1101inaddr(net, len, qbuf, sizeof qbuf) < 0)
279 ansbuf = memget(MAXPACKET);
280 if (ansbuf == NULL) {
282 RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
285 anslen = res_nquery(pvt->res, qbuf, C_IN, T_PTR, ansbuf, MAXPACKET);
287 memput(ansbuf, MAXPACKET);
290 result = get1101mask(this, get1101answer(this, ansbuf, anslen, by_addr,
291 AF_INET, NULL, net, len));
292 memput(ansbuf, MAXPACKET);
296 static struct nwent *
297 get1101answer(struct irs_nw *this,
298 u_char *ansbuf, int anslen, enum by_what by_what,
299 int af, const char *name, const u_char *addr, int addrlen)
301 struct pvt *pvt = (struct pvt *)this->private;
302 int type, class, ancount, qdcount, haveanswer;
307 /* Initialize, and parse header. */
308 eom = ansbuf + anslen;
309 if (ansbuf + HFIXEDSZ > eom) {
310 RES_SET_H_ERRNO(pvt->res, NO_RECOVERY);
313 hp = (HEADER *)ansbuf;
314 cp = ansbuf + HFIXEDSZ;
315 qdcount = ntohs(hp->qdcount);
316 while (qdcount-- > 0) {
317 int n = dn_skipname(cp, eom);
319 if (n < 0 || cp > eom) {
320 RES_SET_H_ERRNO(pvt->res, NO_RECOVERY);
324 ancount = ntohs(hp->ancount);
327 RES_SET_H_ERRNO(pvt->res, HOST_NOT_FOUND);
329 RES_SET_H_ERRNO(pvt->res, TRY_AGAIN);
333 /* Prepare a return structure. */
335 ep = pvt->buf + sizeof(pvt->buf);
336 pvt->net.n_name = NULL;
337 pvt->net.n_aliases = pvt->ali;
338 pvt->net.n_addrtype = af;
339 pvt->net.n_addr = NULL;
340 pvt->net.n_length = addrlen;
342 /* Save input key if given. */
346 int n = strlen(name) + 1;
349 RES_SET_H_ERRNO(pvt->res, NO_RECOVERY);
352 pvt->net.n_name = strcpy(bp, name); /* (checked) */
357 if (addr != NULL && addrlen != 0) {
358 int n = addrlen / 8 + ((addrlen % 8) != 0);
360 if (INADDRSZ > (ep - bp)) {
361 RES_SET_H_ERRNO(pvt->res, NO_RECOVERY);
364 memset(bp, 0, INADDRSZ);
366 pvt->net.n_addr = bp;
374 /* Parse the answer, collect aliases. */
377 while (--ancount >= 0 && cp < eom) {
378 int n = dn_expand(ansbuf, eom, cp, bp, ep - bp);
380 cp += n; /*%< Owner */
381 if (n < 0 || !maybe_dnok(pvt->res, bp) ||
382 cp + 3 * INT16SZ + INT32SZ > eom) {
383 RES_SET_H_ERRNO(pvt->res, NO_RECOVERY);
386 GETSHORT(type, cp); /*%< Type */
387 GETSHORT(class, cp); /*%< Class */
388 cp += INT32SZ; /*%< TTL */
389 GETSHORT(n, cp); /*%< RDLENGTH */
390 if (class == C_IN && type == T_PTR) {
393 nn = dn_expand(ansbuf, eom, cp, bp, ep - bp);
394 if (nn < 0 || !maybe_hnok(pvt->res, bp) || nn != n) {
395 RES_SET_H_ERRNO(pvt->res, NO_RECOVERY);
401 if (pvt->net.n_name == NULL)
402 pvt->net.n_name = bp;
403 else if (ns_samename(pvt->net.n_name, bp) == 1)
413 u_int b1, b2, b3, b4;
415 if (pvt->net.n_addr != NULL ||
416 sscanf(bp, "%u.%u.%u.%u.in-addr.arpa",
417 &b1, &b2, &b3, &b4) != 4)
419 if ((ep - bp) < INADDRSZ) {
420 RES_SET_H_ERRNO(pvt->res, NO_RECOVERY);
423 pvt->net.n_addr = bp;
428 pvt->net.n_length = INADDRSZ * 8;
433 cp += n; /*%< RDATA */
436 RES_SET_H_ERRNO(pvt->res, TRY_AGAIN);
444 static struct nwent *
445 get1101mask(struct irs_nw *this, struct nwent *nwent) {
446 struct pvt *pvt = (struct pvt *)this->private;
447 char qbuf[sizeof "255.255.255.255.in-addr.arpa"], owner[MAXDNAME];
448 int anslen, type, class, ancount, qdcount;
449 u_char *ansbuf, *cp, *eom;
454 if (make1101inaddr(nwent->n_addr, nwent->n_length, qbuf, sizeof qbuf)
456 /* "First, do no harm." */
460 ansbuf = memget(MAXPACKET);
461 if (ansbuf == NULL) {
463 RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
466 /* Query for the A RR that would hold this network's mask. */
467 anslen = res_nquery(pvt->res, qbuf, C_IN, T_A, ansbuf, MAXPACKET);
468 if (anslen < HFIXEDSZ) {
469 memput(ansbuf, MAXPACKET);
473 /* Initialize, and parse header. */
474 hp = (HEADER *)ansbuf;
475 cp = ansbuf + HFIXEDSZ;
476 eom = ansbuf + anslen;
477 qdcount = ntohs(hp->qdcount);
478 while (qdcount-- > 0) {
479 int n = dn_skipname(cp, eom);
481 if (n < 0 || cp > eom) {
482 memput(ansbuf, MAXPACKET);
486 ancount = ntohs(hp->ancount);
488 /* Parse the answer, collect aliases. */
489 while (--ancount >= 0 && cp < eom) {
490 int n = dn_expand(ansbuf, eom, cp, owner, sizeof owner);
492 if (n < 0 || !maybe_dnok(pvt->res, owner))
494 cp += n; /*%< Owner */
495 if (cp + 3 * INT16SZ + INT32SZ > eom)
497 GETSHORT(type, cp); /*%< Type */
498 GETSHORT(class, cp); /*%< Class */
499 cp += INT32SZ; /*%< TTL */
500 GETSHORT(n, cp); /*%< RDLENGTH */
503 if (n == INADDRSZ && class == C_IN && type == T_A &&
504 ns_samename(qbuf, owner) == 1) {
505 /* This A RR indicates the actual netmask. */
509 for (nn = 0; nn < INADDRSZ; nn++)
510 for (mm = 7; mm >= 0; mm--)
511 if (cp[nn] & (1 << mm))
516 cp += n; /*%< RDATA */
518 memput(ansbuf, MAXPACKET);
523 make1101inaddr(const u_char *net, int bits, char *name, int size) {
529 /* Zero fill any whole bytes left out of the prefix. */
530 for (n = (32 - bits) / 8; n > 0; n--) {
531 if (ep - name < (int)(sizeof "0."))
533 m = SPRINTF((name, "0."));
537 /* Format the partial byte, if any, within the prefix. */
538 if ((n = bits % 8) != 0) {
539 if (ep - name < (int)(sizeof "255."))
541 m = SPRINTF((name, "%u.",
542 net[bits / 8] & ~((1 << (8 - n)) - 1)));
546 /* Format the whole bytes within the prefix. */
547 for (n = bits / 8; n > 0; n--) {
548 if (ep - name < (int)(sizeof "255."))
550 m = SPRINTF((name, "%u.", net[n - 1]));
554 /* Add the static text. */
555 if (ep - name < (int)(sizeof "in-addr.arpa"))
557 (void) SPRINTF((name, "in-addr.arpa"));
566 normalize_name(char *name) {
569 /* Make lower case. */
570 for (t = name; *t; t++)
571 if (isascii((unsigned char)*t) && isupper((unsigned char)*t))
572 *t = tolower((*t)&0xff);
574 /* Remove trailing dots. */
575 while (t > name && t[-1] == '.')
580 init(struct irs_nw *this) {
581 struct pvt *pvt = (struct pvt *)this->private;
583 if (!pvt->res && !nw_res_get(this))
585 if (((pvt->res->options & RES_INIT) == 0U) &&
586 res_ninit(pvt->res) == -1)