/* * Copyright (c) 1985, 1988, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ /* * Portions Copyright (c) 1996-1999 by Internet Software Consortium. * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS * SOFTWARE. */ /* from gethostnamadr.c 8.1 (Berkeley) 6/4/93 */ /* BIND Id: gethnamaddr.c,v 8.15 1996/05/22 04:56:30 vixie Exp $ */ #if defined(LIBC_SCCS) && !defined(lint) static const char rcsid[] = "$Id: dns_ho.c,v 1.28 2000/04/20 07:47:54 vixie Exp $"; #endif /* LIBC_SCCS and not lint */ /* Imports. */ #include "port_before.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "port_after.h" #include "irs_p.h" #include "dns_p.h" #ifdef SPRINTF_CHAR # define SPRINTF(x) strlen(sprintf/**/x) #else # define SPRINTF(x) sprintf x #endif /* Definitions. */ #define MAXALIASES 35 #define MAXADDRS 35 #if PACKETSZ > 1024 #define MAXPACKET PACKETSZ #else #define MAXPACKET 1024 #endif #define BOUNDS_CHECK(ptr, count) \ if ((ptr) + (count) > eom) { \ had_error++; \ continue; \ } else (void)0 struct pvt { struct hostent host; char * h_addr_ptrs[MAXADDRS + 1]; char * host_aliases[MAXALIASES]; char hostbuf[8*1024]; u_char host_addr[16]; /* IPv4 or IPv6 */ struct __res_state *res; void (*free_res)(void *); }; typedef union { int32_t al; char ac; } align; static const u_char mapped[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0xff,0xff }; static const u_char tunnelled[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0,0 }; /* Note: the IPv6 loopback address is in the "tunnel" space */ static const u_char v6local[] = { 0,0, 0,1 }; /* last 4 bytes of IPv6 addr */ /* Forwards. */ static void ho_close(struct irs_ho *this); static struct hostent * ho_byname(struct irs_ho *this, const char *name); static struct hostent * ho_byname2(struct irs_ho *this, const char *name, int af); static struct hostent * ho_byaddr(struct irs_ho *this, const void *addr, int len, int af); static struct hostent * ho_next(struct irs_ho *this); static void ho_rewind(struct irs_ho *this); static void ho_minimize(struct irs_ho *this); static struct __res_state * ho_res_get(struct irs_ho *this); static void ho_res_set(struct irs_ho *this, struct __res_state *res, void (*free_res)(void *)); static void map_v4v6_hostent(struct hostent *hp, char **bp, int *len); static void addrsort(res_state, char **, int); static struct hostent * gethostans(struct irs_ho *this, const u_char *ansbuf, int anslen, const char *qname, int qtype, int af, int size); static int init(struct irs_ho *this); /* Exports. */ struct irs_ho * irs_dns_ho(struct irs_acc *this) { struct irs_ho *ho; struct pvt *pvt; if (!(pvt = memget(sizeof *pvt))) { errno = ENOMEM; return (NULL); } memset(pvt, 0, sizeof *pvt); if (!(ho = memget(sizeof *ho))) { memput(pvt, sizeof *pvt); errno = ENOMEM; return (NULL); } memset(ho, 0x5e, sizeof *ho); ho->private = pvt; ho->close = ho_close; ho->byname = ho_byname; ho->byname2 = ho_byname2; ho->byaddr = ho_byaddr; ho->next = ho_next; ho->rewind = ho_rewind; ho->minimize = ho_minimize; ho->res_get = ho_res_get; ho->res_set = ho_res_set; return (ho); } /* Methods. */ static void ho_close(struct irs_ho *this) { struct pvt *pvt = (struct pvt *)this->private; ho_minimize(this); if (pvt->res && pvt->free_res) (*pvt->free_res)(pvt->res); if (pvt) memput(pvt, sizeof *pvt); memput(this, sizeof *this); } static struct hostent * ho_byname(struct irs_ho *this, const char *name) { struct pvt *pvt = (struct pvt *)this->private; struct hostent *hp; if (init(this) == -1) return (NULL); if (pvt->res->options & RES_USE_INET6) { hp = ho_byname2(this, name, AF_INET6); if (hp) return (hp); } return (ho_byname2(this, name, AF_INET)); } static struct hostent * ho_byname2(struct irs_ho *this, const char *name, int af) { struct pvt *pvt = (struct pvt *)this->private; int n, size, type; u_char buf[MAXPACKET]; char tmp[NS_MAXDNAME]; const char *cp; if (init(this) == -1) return (NULL); switch (af) { case AF_INET: size = INADDRSZ; type = T_A; break; case AF_INET6: size = IN6ADDRSZ; type = T_AAAA; break; default: RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL); errno = EAFNOSUPPORT; return (NULL); } /* * if there aren't any dots, it could be a user-level alias. * this is also done in res_nquery() since we are not the only * function that looks up host names. */ if (!strchr(name, '.') && (cp = res_hostalias(pvt->res, name, tmp, sizeof tmp))) name = cp; if ((n = res_nsearch(pvt->res, name, C_IN, type, buf, sizeof buf)) < 0) return (NULL); return (gethostans(this, buf, n, name, type, af, size)); } static struct hostent * ho_byaddr(struct irs_ho *this, const void *addr, int len, int af) { struct pvt *pvt = (struct pvt *)this->private; const u_char *uaddr = addr; char qbuf[MAXDNAME+1], *qp; u_char buf[MAXPACKET]; struct hostent *hp; int n, size; if (init(this) == -1) return (NULL); if (af == AF_INET6 && len == IN6ADDRSZ && (!memcmp(uaddr, mapped, sizeof mapped) || (!memcmp(uaddr, tunnelled, sizeof tunnelled) && memcmp(&uaddr[sizeof tunnelled], v6local, sizeof(v6local))))) { /* Unmap. */ addr = (char *)addr + sizeof mapped; uaddr += sizeof mapped; af = AF_INET; len = INADDRSZ; } switch (af) { case AF_INET: size = INADDRSZ; break; case AF_INET6: size = IN6ADDRSZ; break; default: errno = EAFNOSUPPORT; RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL); return (NULL); } if (size > len) { errno = EINVAL; RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL); return (NULL); } switch (af) { case AF_INET: (void) sprintf(qbuf, "%u.%u.%u.%u.in-addr.arpa", (uaddr[3] & 0xff), (uaddr[2] & 0xff), (uaddr[1] & 0xff), (uaddr[0] & 0xff)); break; case AF_INET6: qp = qbuf; for (n = IN6ADDRSZ - 1; n >= 0; n--) { qp += SPRINTF((qp, "%x.%x.", uaddr[n] & 0xf, (uaddr[n] >> 4) & 0xf)); } strcpy(qp, "ip6.int"); break; default: abort(); } n = res_nquery(pvt->res, qbuf, C_IN, T_PTR, buf, sizeof buf); if (n < 0) return (NULL); hp = gethostans(this, buf, n, qbuf, T_PTR, af, size); if (!hp) return (NULL); /* H_ERRNO was set by gethostans() */ memcpy(pvt->host_addr, addr, len); pvt->h_addr_ptrs[0] = (char *)pvt->host_addr; pvt->h_addr_ptrs[1] = NULL; if (af == AF_INET && (pvt->res->options & RES_USE_INET6)) { map_v4v6_address((char*)pvt->host_addr, (char*)pvt->host_addr); pvt->host.h_addrtype = AF_INET6; pvt->host.h_length = IN6ADDRSZ; } RES_SET_H_ERRNO(pvt->res, NETDB_SUCCESS); return (hp); } static struct hostent * ho_next(struct irs_ho *this) { return (NULL); } static void ho_rewind(struct irs_ho *this) { /* NOOP */ } static void ho_minimize(struct irs_ho *this) { struct pvt *pvt = (struct pvt *)this->private; if (pvt->res) res_nclose(pvt->res); } static struct __res_state * ho_res_get(struct irs_ho *this) { struct pvt *pvt = (struct pvt *)this->private; if (!pvt->res) { struct __res_state *res; res = (struct __res_state *)malloc(sizeof *res); if (!res) { errno = ENOMEM; return (NULL); } memset(res, 0, sizeof *res); ho_res_set(this, res, free); } return (pvt->res); } static void ho_res_set(struct irs_ho *this, struct __res_state *res, void (*free_res)(void *)) { struct pvt *pvt = (struct pvt *)this->private; if (pvt->res && pvt->free_res) { res_nclose(pvt->res); (*pvt->free_res)(pvt->res); } pvt->res = res; pvt->free_res = free_res; } /* Private. */ static struct hostent * gethostans(struct irs_ho *this, const u_char *ansbuf, int anslen, const char *qname, int qtype, int af, int size) { struct pvt *pvt = (struct pvt *)this->private; int type, class, buflen, ancount, qdcount, n, haveanswer, had_error; int (*name_ok)(const char *); const HEADER *hp; const u_char *eom; const u_char *cp; const char *tname, **tap; char *bp, **ap, **hap; char tbuf[MAXDNAME+1]; tname = qname; eom = ansbuf + anslen; switch (qtype) { case T_A: case T_AAAA: name_ok = res_hnok; break; case T_PTR: name_ok = res_dnok; break; default: abort(); } pvt->host.h_addrtype = af; pvt->host.h_length = size; pvt->host.h_name = NULL; /* * Find first satisfactory answer. */ if (ansbuf + HFIXEDSZ > eom) { RES_SET_H_ERRNO(pvt->res, NO_RECOVERY); return (NULL); } hp = (HEADER *)ansbuf; ancount = ntohs(hp->ancount); qdcount = ntohs(hp->qdcount); bp = pvt->hostbuf; buflen = sizeof pvt->hostbuf; cp = ansbuf + HFIXEDSZ; if (qdcount != 1) { RES_SET_H_ERRNO(pvt->res, NO_RECOVERY); return (NULL); } n = dn_expand(ansbuf, eom, cp, bp, buflen); if (n < 0 || !maybe_ok(pvt->res, bp, name_ok)) { RES_SET_H_ERRNO(pvt->res, NO_RECOVERY); return (NULL); } cp += n + QFIXEDSZ; if (cp > eom) { RES_SET_H_ERRNO(pvt->res, NO_RECOVERY); return (NULL); } if (qtype == T_A || qtype == T_AAAA) { /* res_nsend() has already verified that the query name is the * same as the one we sent; this just gets the expanded name * (i.e., with the succeeding search-domain tacked on). */ n = strlen(bp) + 1; /* for the \0 */ if (n > MAXHOSTNAMELEN) { RES_SET_H_ERRNO(pvt->res, NO_RECOVERY); return (NULL); } pvt->host.h_name = bp; bp += n; buflen -= n; /* The qname can be abbreviated, but h_name is now absolute. */ qname = pvt->host.h_name; } ap = pvt->host_aliases; *ap = NULL; pvt->host.h_aliases = pvt->host_aliases; hap = pvt->h_addr_ptrs; *hap = NULL; pvt->host.h_addr_list = pvt->h_addr_ptrs; haveanswer = 0; had_error = 0; while (ancount-- > 0 && cp < eom && !had_error) { n = dn_expand(ansbuf, eom, cp, bp, buflen); if (n < 0 || !maybe_ok(pvt->res, bp, name_ok)) { had_error++; continue; } cp += n; /* name */ BOUNDS_CHECK(cp, 3 * INT16SZ + INT32SZ); type = ns_get16(cp); cp += INT16SZ; /* type */ class = ns_get16(cp); cp += INT16SZ + INT32SZ; /* class, TTL */ n = ns_get16(cp); cp += INT16SZ; /* len */ BOUNDS_CHECK(cp, n); if (class != C_IN) { cp += n; continue; } if ((qtype == T_A || qtype == T_AAAA) && type == T_CNAME) { if (ap >= &pvt->host_aliases[MAXALIASES-1]) continue; n = dn_expand(ansbuf, eom, cp, tbuf, sizeof tbuf); if (n < 0 || !maybe_ok(pvt->res, tbuf, name_ok)) { had_error++; continue; } cp += n; /* Store alias. */ *ap++ = bp; n = strlen(bp) + 1; /* for the \0 */ bp += n; buflen -= n; /* Get canonical name. */ n = strlen(tbuf) + 1; /* for the \0 */ if (n > buflen || n > MAXHOSTNAMELEN) { had_error++; continue; } strcpy(bp, tbuf); pvt->host.h_name = bp; bp += n; buflen -= n; continue; } if (qtype == T_PTR && type == T_CNAME) { n = dn_expand(ansbuf, eom, cp, tbuf, sizeof tbuf); if (n < 0 || !maybe_dnok(pvt->res, tbuf)) { had_error++; continue; } cp += n; /* Get canonical name. */ n = strlen(tbuf) + 1; /* for the \0 */ if (n > buflen) { had_error++; continue; } strcpy(bp, tbuf); tname = bp; bp += n; buflen -= n; continue; } if (type != qtype) { cp += n; continue; } switch (type) { case T_PTR: if (ns_samename(tname, bp) != 1) { cp += n; continue; } n = dn_expand(ansbuf, eom, cp, bp, buflen); if (n < 0 || !maybe_hnok(pvt->res, bp) || n >= MAXHOSTNAMELEN) { had_error++; break; } cp += n; if (!haveanswer) pvt->host.h_name = bp; else if (ap < &pvt->host_aliases[MAXALIASES-1]) *ap++ = bp; else n = -1; if (n != -1) { n = strlen(bp) + 1; /* for the \0 */ bp += n; buflen -= n; } break; case T_A: case T_AAAA: if (ns_samename(pvt->host.h_name, bp) != 1) { cp += n; continue; } if (n != pvt->host.h_length) { cp += n; continue; } if (!haveanswer) { int nn; nn = strlen(bp) + 1; /* for the \0 */ if (nn >= MAXHOSTNAMELEN) { cp += n; had_error++; continue; } pvt->host.h_name = bp; bp += nn; buflen -= nn; } /* Ensure alignment. */ bp += sizeof(align) - ((u_long)bp % sizeof(align)); /* Avoid overflows. */ if (bp + n >= &pvt->hostbuf[sizeof pvt->hostbuf]) { had_error++; continue; } if (hap >= &pvt->h_addr_ptrs[MAXADDRS-1]) { cp += n; continue; } /* Suppress duplicates. */ for (tap = (const char **)pvt->h_addr_ptrs; *tap != NULL; tap++) if (memcmp(*tap, cp, n) == 0) break; if (*tap != NULL) { cp += n; continue; } /* Store address. */ memcpy(*hap++ = bp, cp, n); *hap = NULL; bp += n; cp += n; break; default: abort(); } if (!had_error) haveanswer++; } if (haveanswer) { *ap = NULL; if (pvt->res->nsort && haveanswer > 1 && qtype == T_A) addrsort(pvt->res, pvt->h_addr_ptrs, haveanswer); if (!pvt->host.h_name) { n = strlen(qname) + 1; /* for the \0 */ if (n > buflen || n >= MAXHOSTNAMELEN) goto no_recovery; strcpy(bp, qname); pvt->host.h_name = bp; bp += n; buflen -= n; } if (pvt->res->options & RES_USE_INET6) map_v4v6_hostent(&pvt->host, &bp, &buflen); RES_SET_H_ERRNO(pvt->res, NETDB_SUCCESS); return (&pvt->host); } no_recovery: RES_SET_H_ERRNO(pvt->res, NO_RECOVERY); return (NULL); } static void map_v4v6_hostent(struct hostent *hp, char **bpp, int *lenp) { char **ap; if (hp->h_addrtype != AF_INET || hp->h_length != INADDRSZ) return; hp->h_addrtype = AF_INET6; hp->h_length = IN6ADDRSZ; for (ap = hp->h_addr_list; *ap; ap++) { int i = sizeof(align) - ((u_long)*bpp % sizeof(align)); if (*lenp < (i + IN6ADDRSZ)) { /* Out of memory. Truncate address list here. */ *ap = NULL; return; } *bpp += i; *lenp -= i; map_v4v6_address(*ap, *bpp); *ap = *bpp; *bpp += IN6ADDRSZ; *lenp -= IN6ADDRSZ; } } static void addrsort(res_state statp, char **ap, int num) { int i, j, needsort = 0, aval[MAXADDRS]; char **p; p = ap; for (i = 0; i < num; i++, p++) { for (j = 0 ; (unsigned)j < statp->nsort; j++) if (statp->sort_list[j].addr.s_addr == (((struct in_addr *)(*p))->s_addr & statp->sort_list[j].mask)) break; aval[i] = j; if (needsort == 0 && i > 0 && j < aval[i-1]) needsort = i; } if (!needsort) return; while (needsort < num) { for (j = needsort - 1; j >= 0; j--) { if (aval[j] > aval[j+1]) { char *hp; i = aval[j]; aval[j] = aval[j+1]; aval[j+1] = i; hp = ap[j]; ap[j] = ap[j+1]; ap[j+1] = hp; } else break; } needsort++; } } static int init(struct irs_ho *this) { struct pvt *pvt = (struct pvt *)this->private; if (!pvt->res && !ho_res_get(this)) return (-1); if (((pvt->res->options & RES_INIT) == 0) && res_ninit(pvt->res) == -1) return (-1); return (0); }