/* * ++Copyright++ 1985, 1988, 1993 * - * 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) 1993 by Digital Equipment Corporation. * * 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, and that * the name of Digital Equipment Corporation not be used in advertising or * publicity pertaining to distribution of the document or software without * specific, written prior permission. * * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT * CORPORATION 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. * - * --Copyright-- */ #if defined(LIBC_SCCS) && !defined(lint) static char sccsid[] = "@(#)gethostnamadr.c 8.1 (Berkeley) 6/4/93"; static char fromrcsid[] = "From: Id: gethnamaddr.c,v 8.23 1998/04/07 04:59:46 vixie Exp $"; static char rcsid[] = "$Id$"; #endif /* LIBC_SCCS and not lint */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "res_config.h" #define SPRINTF(x) ((size_t)sprintf x) #define MAXALIASES 35 #define MAXADDRS 35 static const char AskedForGot[] = "gethostby*.gethostanswer: asked for \"%s\", got \"%s\""; static char *h_addr_ptrs[MAXADDRS + 1]; static struct hostent host; static char *host_aliases[MAXALIASES]; static char hostbuf[8*1024]; static u_char host_addr[16]; /* IPv4 or IPv6 */ #ifdef RESOLVSORT static void addrsort __P((char **, int)); #endif #if PACKETSZ > 1024 #define MAXPACKET PACKETSZ #else #define MAXPACKET 1024 #endif typedef union { HEADER hdr; u_char buf[MAXPACKET]; } querybuf; typedef union { int32_t al; char ac; } align; extern int h_errno; int _dns_ttl_; #ifdef DEBUG static void dprintf(msg, num) char *msg; int num; { if (_res.options & RES_DEBUG) { int save = errno; printf(msg, num); errno = save; } } #else # define dprintf(msg, num) /*nada*/ #endif #define BOUNDED_INCR(x) \ do { \ cp += x; \ if (cp > eom) { \ h_errno = NO_RECOVERY; \ return (NULL); \ } \ } while (0) #define BOUNDS_CHECK(ptr, count) \ do { \ if ((ptr) + (count) > eom) { \ h_errno = NO_RECOVERY; \ return (NULL); \ } \ } while (0) static struct hostent * gethostanswer(answer, anslen, qname, qtype) const querybuf *answer; int anslen; const char *qname; int qtype; { register const HEADER *hp; register const u_char *cp; register int n; const u_char *eom, *erdata; char *bp, **ap, **hap; int type, class, buflen, ancount, qdcount; int haveanswer, had_error; int toobig = 0; char tbuf[MAXDNAME]; const char *tname; int (*name_ok) __P((const char *)); tname = qname; host.h_name = NULL; eom = answer->buf + anslen; switch (qtype) { case T_A: case T_AAAA: name_ok = res_hnok; break; case T_PTR: name_ok = res_dnok; break; default: h_errno = NO_RECOVERY; return (NULL); /* XXX should be abort(); */ } /* * find first satisfactory answer */ hp = &answer->hdr; ancount = ntohs(hp->ancount); qdcount = ntohs(hp->qdcount); bp = hostbuf; buflen = sizeof hostbuf; cp = answer->buf; BOUNDED_INCR(HFIXEDSZ); if (qdcount != 1) { h_errno = NO_RECOVERY; return (NULL); } n = dn_expand(answer->buf, eom, cp, bp, buflen); if ((n < 0) || !(*name_ok)(bp)) { h_errno = NO_RECOVERY; return (NULL); } BOUNDED_INCR(n + QFIXEDSZ); if (qtype == T_A || qtype == T_AAAA) { /* res_send() 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) { h_errno = NO_RECOVERY; return (NULL); } host.h_name = bp; bp += n; buflen -= n; /* The qname can be abbreviated, but h_name is now absolute. */ qname = host.h_name; } ap = host_aliases; *ap = NULL; host.h_aliases = host_aliases; hap = h_addr_ptrs; *hap = NULL; host.h_addr_list = h_addr_ptrs; haveanswer = 0; had_error = 0; _dns_ttl_ = -1; while (ancount-- > 0 && cp < eom && !had_error) { n = dn_expand(answer->buf, eom, cp, bp, buflen); if ((n < 0) || !(*name_ok)(bp)) { had_error++; continue; } cp += n; /* name */ BOUNDS_CHECK(cp, 3 * INT16SZ + INT32SZ); type = _getshort(cp); cp += INT16SZ; /* type */ class = _getshort(cp); cp += INT16SZ; /* class */ if (qtype == T_A && type == T_A) _dns_ttl_ = _getlong(cp); cp += INT32SZ; /* TTL */ n = _getshort(cp); cp += INT16SZ; /* len */ BOUNDS_CHECK(cp, n); erdata = cp + n; if (class != C_IN) { /* XXX - debug? syslog? */ cp += n; continue; /* XXX - had_error++ ? */ } if ((qtype == T_A || qtype == T_AAAA) && type == T_CNAME) { if (ap >= &host_aliases[MAXALIASES-1]) continue; n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); if ((n < 0) || !(*name_ok)(tbuf)) { had_error++; continue; } cp += n; if (cp != erdata) { h_errno = NO_RECOVERY; return (NULL); } /* Store alias. */ *ap++ = bp; n = strlen(bp) + 1; /* for the \0 */ if (n >= MAXHOSTNAMELEN) { had_error++; continue; } 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); host.h_name = bp; bp += n; buflen -= n; continue; } if (qtype == T_PTR && type == T_CNAME) { n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); if (n < 0 || !res_dnok(tbuf)) { had_error++; continue; } cp += n; if (cp != erdata) { h_errno = NO_RECOVERY; return (NULL); } /* Get canonical name. */ n = strlen(tbuf) + 1; /* for the \0 */ if (n > buflen || n >= MAXHOSTNAMELEN) { had_error++; continue; } strcpy(bp, tbuf); tname = bp; bp += n; buflen -= n; continue; } if (type != qtype) { syslog(LOG_NOTICE|LOG_AUTH, "gethostby*.gethostanswer: asked for \"%s %s %s\", got type \"%s\"", qname, p_class(C_IN), p_type(qtype), p_type(type)); cp += n; continue; /* XXX - had_error++ ? */ } switch (type) { case T_PTR: if (strcasecmp(tname, bp) != 0) { syslog(LOG_NOTICE|LOG_AUTH, AskedForGot, qname, bp); cp += n; continue; /* XXX - had_error++ ? */ } n = dn_expand(answer->buf, eom, cp, bp, buflen); if ((n < 0) || !res_hnok(bp)) { had_error++; break; } #if MULTI_PTRS_ARE_ALIASES cp += n; if (cp != erdata) { h_errno = NO_RECOVERY; return (NULL); } if (!haveanswer) host.h_name = bp; else if (ap < &host_aliases[MAXALIASES-1]) *ap++ = bp; else n = -1; if (n != -1) { n = strlen(bp) + 1; /* for the \0 */ if (n >= MAXHOSTNAMELEN) { had_error++; break; } bp += n; buflen -= n; } break; #else host.h_name = bp; if (_res.options & RES_USE_INET6) { n = strlen(bp) + 1; /* for the \0 */ if (n >= MAXHOSTNAMELEN) { had_error++; break; } bp += n; buflen -= n; _map_v4v6_hostent(&host, &bp, &buflen); } h_errno = NETDB_SUCCESS; return (&host); #endif case T_A: case T_AAAA: if (strcasecmp(host.h_name, bp) != 0) { syslog(LOG_NOTICE|LOG_AUTH, AskedForGot, host.h_name, bp); cp += n; continue; /* XXX - had_error++ ? */ } if (n != host.h_length) { cp += n; continue; } if (!haveanswer) { register int nn; host.h_name = bp; nn = strlen(bp) + 1; /* for the \0 */ bp += nn; buflen -= nn; } bp += sizeof(align) - ((u_long)bp % sizeof(align)); if (bp + n >= &hostbuf[sizeof hostbuf]) { dprintf("size (%d) too big\n", n); had_error++; continue; } if (hap >= &h_addr_ptrs[MAXADDRS-1]) { if (!toobig++) dprintf("Too many addresses (%d)\n", MAXADDRS); cp += n; continue; } bcopy(cp, *hap++ = bp, n); bp += n; buflen -= n; cp += n; if (cp != erdata) { h_errno = NO_RECOVERY; return (NULL); } break; default: dprintf("Impossible condition (type=%d)\n", type); h_errno = NO_RECOVERY; return (NULL); /* BIND has abort() here, too risky on bad data */ } if (!had_error) haveanswer++; } if (haveanswer) { *ap = NULL; *hap = NULL; # if defined(RESOLVSORT) /* * Note: we sort even if host can take only one address * in its return structures - should give it the "best" * address in that case, not some random one */ if (_res.nsort && haveanswer > 1 && qtype == T_A) addrsort(h_addr_ptrs, haveanswer); # endif /*RESOLVSORT*/ if (!host.h_name) { n = strlen(qname) + 1; /* for the \0 */ if (n > buflen || n >= MAXHOSTNAMELEN) goto no_recovery; strcpy(bp, qname); host.h_name = bp; bp += n; buflen -= n; } if (_res.options & RES_USE_INET6) _map_v4v6_hostent(&host, &bp, &buflen); h_errno = NETDB_SUCCESS; return (&host); } no_recovery: h_errno = NO_RECOVERY; return (NULL); } struct hostent * __dns_getanswer(answer, anslen, qname, qtype) const char *answer; int anslen; const char *qname; int qtype; { switch(qtype) { case T_AAAA: host.h_addrtype = AF_INET6; host.h_length = IN6ADDRSZ; break; case T_A: default: host.h_addrtype = AF_INET; host.h_length = INADDRSZ; break; } return(gethostanswer((const querybuf *)answer, anslen, qname, qtype)); } struct hostent * _gethostbydnsname(name, af) const char *name; int af; { querybuf buf; register const char *cp; char *bp; int n, size, type, len; if ((_res.options & RES_INIT) == 0 && res_init() == -1) { h_errno = NETDB_INTERNAL; return (NULL); } switch (af) { case AF_INET: size = INADDRSZ; type = T_A; break; case AF_INET6: size = IN6ADDRSZ; type = T_AAAA; break; default: h_errno = NETDB_INTERNAL; errno = EAFNOSUPPORT; return (NULL); } host.h_addrtype = af; host.h_length = size; /* * if there aren't any dots, it could be a user-level alias. * this is also done in res_query() since we are not the only * function that looks up host names. */ if (!strchr(name, '.') && (cp = __hostalias(name))) name = cp; /* * disallow names consisting only of digits/dots, unless * they end in a dot. */ if (isdigit((int)name[0])) for (cp = name;; ++cp) { if (!*cp) { if (*--cp == '.') break; /* * All-numeric, no dot at the end. * Fake up a hostent as if we'd actually * done a lookup. */ if (inet_pton(af, name, host_addr) <= 0) { h_errno = HOST_NOT_FOUND; return (NULL); } strncpy(hostbuf, name, MAXDNAME); hostbuf[MAXDNAME] = '\0'; bp = hostbuf + MAXDNAME; len = sizeof hostbuf - MAXDNAME; host.h_name = hostbuf; host.h_aliases = host_aliases; host_aliases[0] = NULL; h_addr_ptrs[0] = (char *)host_addr; h_addr_ptrs[1] = NULL; host.h_addr_list = h_addr_ptrs; if (_res.options & RES_USE_INET6) _map_v4v6_hostent(&host, &bp, &len); h_errno = NETDB_SUCCESS; return (&host); } if (!isdigit((int)*cp) && *cp != '.') break; } if ((isxdigit((int)name[0]) && strchr(name, ':') != NULL) || name[0] == ':') for (cp = name;; ++cp) { if (!*cp) { if (*--cp == '.') break; /* * All-IPv6-legal, no dot at the end. * Fake up a hostent as if we'd actually * done a lookup. */ if (inet_pton(af, name, host_addr) <= 0) { h_errno = HOST_NOT_FOUND; return (NULL); } strncpy(hostbuf, name, MAXDNAME); hostbuf[MAXDNAME] = '\0'; bp = hostbuf + MAXDNAME; len = sizeof hostbuf - MAXDNAME; host.h_name = hostbuf; host.h_aliases = host_aliases; host_aliases[0] = NULL; h_addr_ptrs[0] = (char *)host_addr; h_addr_ptrs[1] = NULL; host.h_addr_list = h_addr_ptrs; h_errno = NETDB_SUCCESS; return (&host); } if (!isxdigit((int)*cp) && *cp != ':' && *cp != '.') break; } if ((n = res_search(name, C_IN, type, buf.buf, sizeof(buf))) < 0) { dprintf("res_search failed (%d)\n", n); return (NULL); } return (gethostanswer(&buf, n, name, type)); } struct hostent * _gethostbydnsaddr(addr, len, af) const char *addr; /* XXX should have been def'd as u_char! */ int len, af; { const u_char *uaddr = (const u_char *)addr; 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 }; int n, size; querybuf buf; register struct hostent *hp; char qbuf[MAXDNAME+1], *qp; #ifdef SUNSECURITY register struct hostent *rhp; char **haddr; u_long old_options; char hname2[MAXDNAME+1]; #endif /*SUNSECURITY*/ if ((_res.options & RES_INIT) == 0 && res_init() == -1) { h_errno = NETDB_INTERNAL; return (NULL); } if (af == AF_INET6 && len == IN6ADDRSZ && (!bcmp(uaddr, mapped, sizeof mapped) || !bcmp(uaddr, tunnelled, sizeof tunnelled))) { /* Unmap. */ 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; h_errno = NETDB_INTERNAL; return (NULL); } if (size != len) { errno = EINVAL; h_errno = 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_query(qbuf, C_IN, T_PTR, (u_char *)buf.buf, sizeof buf.buf); if (n < 0) { dprintf("res_query failed (%d)\n", n); return (NULL); } if (!(hp = gethostanswer(&buf, n, qbuf, T_PTR))) return (NULL); /* h_errno was set by gethostanswer() */ #ifdef SUNSECURITY if (af == AF_INET) { /* * turn off search as the name should be absolute, * 'localhost' should be matched by defnames */ strncpy(hname2, hp->h_name, MAXDNAME); hname2[MAXDNAME] = '\0'; old_options = _res.options; _res.options &= ~RES_DNSRCH; _res.options |= RES_DEFNAMES; if (!(rhp = gethostbyname(hname2))) { syslog(LOG_NOTICE|LOG_AUTH, "gethostbyaddr: No A record for %s (verifying [%s])", hname2, inet_ntoa(*((struct in_addr *)addr))); _res.options = old_options; h_errno = HOST_NOT_FOUND; return (NULL); } _res.options = old_options; for (haddr = rhp->h_addr_list; *haddr; haddr++) if (!memcmp(*haddr, addr, INADDRSZ)) break; if (!*haddr) { syslog(LOG_NOTICE|LOG_AUTH, "gethostbyaddr: A record of %s != PTR record [%s]", hname2, inet_ntoa(*((struct in_addr *)addr))); h_errno = HOST_NOT_FOUND; return (NULL); } } #endif /*SUNSECURITY*/ hp->h_addrtype = af; hp->h_length = len; bcopy(addr, host_addr, len); h_addr_ptrs[0] = (char *)host_addr; h_addr_ptrs[1] = NULL; if (af == AF_INET && (_res.options & RES_USE_INET6)) { _map_v4v6_address((char*)host_addr, (char*)host_addr); hp->h_addrtype = AF_INET6; hp->h_length = IN6ADDRSZ; } h_errno = NETDB_SUCCESS; return (hp); } #ifdef RESOLVSORT static void addrsort(ap, num) char **ap; int num; { int i, j; char **p; short aval[MAXADDRS]; int needsort = 0; p = ap; for (i = 0; i < num; i++, p++) { for (j = 0 ; (unsigned)j < _res.nsort; j++) if (_res.sort_list[j].addr.s_addr == (((struct in_addr *)(*p))->s_addr & _res.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++; } } #endif void _sethostdnsent(stayopen) int stayopen; { if ((_res.options & RES_INIT) == 0 && res_init() == -1) return; if (stayopen) _res.options |= RES_STAYOPEN | RES_USEVC; } void _endhostdnsent() { _res.options &= ~(RES_STAYOPEN | RES_USEVC); res_close(); }