/*- * 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[] = "From: @(#)gethostnamadr.c 8.1 (Berkeley) 6/4/93"; /*static char rcsid[] = "From: Id: gethnamaddr.c,v 4.9.1.1 1993/05/02 22:43:03 vixie Rel ";*/ static const char rcsid[] = "$Id: gethostnamadr.c,v 1.2 1994/08/09 20:23:14 wollman Exp $"; #endif /* LIBC_SCCS and not lint */ #include #include #include #include #include #include #include #include #include #include #include #define MAXALIASES 35 #define MAXADDRS 35 #define _PATH_HOSTCONF "/etc/host.conf" enum service_type { SERVICE_NONE = 0, SERVICE_BIND, SERVICE_HOSTS, SERVICE_NIS }; #define SERVICE_MAX SERVICE_NIS static struct { const char *name; enum service_type type; } service_names[] = { { "hosts", SERVICE_HOSTS }, { "/etc/hosts", SERVICE_HOSTS }, { "hosttable", SERVICE_HOSTS }, { "htable", SERVICE_HOSTS }, { "bind", SERVICE_BIND }, { "dns", SERVICE_BIND }, { "domain", SERVICE_BIND }, { "yp", SERVICE_NIS }, { "yellowpages", SERVICE_NIS }, { "nis", SERVICE_NIS }, { 0, SERVICE_NONE } }; static enum service_type service_order[SERVICE_MAX + 1]; static int service_done = 0; static char *h_addr_ptrs[MAXADDRS + 1]; static struct hostent host; static char *host_aliases[MAXALIASES]; static char hostbuf[BUFSIZ+1]; static struct in_addr host_addr; static FILE *hostf = NULL; static char hostaddr[MAXADDRS]; static char *host_addrs[2]; static int stayopen = 0; #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; static enum service_type get_service_name(const char *name) { int i; for(i = 0; service_names[i].type != SERVICE_NONE; i++) { if(!strcasecmp(name, service_names[i].name)) { return service_names[i].type; } } return SERVICE_NONE; } static void init_services() { char *cp, buf[BUFSIZ]; register int cc = 0; FILE *fd; if ((fd = (FILE *)fopen(_PATH_HOSTCONF, "r")) == NULL) { /* make some assumptions */ service_order[0] = SERVICE_BIND; service_order[1] = SERVICE_HOSTS; service_order[2] = SERVICE_NONE; } else { while (fgets(buf, BUFSIZ, fd) != NULL && cc < SERVICE_MAX) { if(buf[0] == '#') continue; cp = strtok(buf, "\n \t,:;"); do { if(!isalpha(cp[0])) continue; service_order[cc] = get_service_name(buf); if(service_order[cc] != SERVICE_NONE) cc++; } while((cp = strtok((char *)0, "\n \t,:;")) && (cc < SERVICE_MAX)); } service_order[cc] = SERVICE_NONE; fclose(fd); } service_done = 1; } static struct hostent * getanswer(answer, anslen, iquery) querybuf *answer; int anslen; int iquery; { register HEADER *hp; register u_char *cp; register int n; u_char *eom; char *bp, **ap; int type, class, buflen, ancount, qdcount; int haveanswer, getclass = C_ANY; char **hap; eom = answer->buf + anslen; /* * find first satisfactory answer */ hp = &answer->hdr; ancount = ntohs(hp->ancount); qdcount = ntohs(hp->qdcount); bp = hostbuf; buflen = sizeof(hostbuf); cp = answer->buf + sizeof(HEADER); if (qdcount) { if (iquery) { if ((n = dn_expand((u_char *)answer->buf, (u_char *)eom, (u_char *)cp, (u_char *)bp, buflen)) < 0) { h_errno = NO_RECOVERY; return ((struct hostent *) NULL); } cp += n + QFIXEDSZ; host.h_name = bp; n = strlen(bp) + 1; bp += n; buflen -= n; } else cp += __dn_skipname(cp, eom) + QFIXEDSZ; while (--qdcount > 0) cp += __dn_skipname(cp, eom) + QFIXEDSZ; } else if (iquery) { if (hp->aa) h_errno = HOST_NOT_FOUND; else h_errno = TRY_AGAIN; return ((struct hostent *) NULL); } ap = host_aliases; *ap = NULL; host.h_aliases = host_aliases; hap = h_addr_ptrs; *hap = NULL; #if BSD >= 43 || defined(h_addr) /* new-style hostent structure */ host.h_addr_list = h_addr_ptrs; #endif haveanswer = 0; while (--ancount >= 0 && cp < eom) { if ((n = dn_expand((u_char *)answer->buf, (u_char *)eom, (u_char *)cp, (u_char *)bp, buflen)) < 0) break; cp += n; type = _getshort(cp); cp += sizeof(u_int16_t); class = _getshort(cp); cp += sizeof(u_int16_t) + sizeof(u_int32_t); n = _getshort(cp); cp += sizeof(u_int16_t); if (type == T_CNAME) { cp += n; if (ap >= &host_aliases[MAXALIASES-1]) continue; *ap++ = bp; n = strlen(bp) + 1; bp += n; buflen -= n; continue; } if (iquery && type == T_PTR) { if ((n = dn_expand((u_char *)answer->buf, (u_char *)eom, (u_char *)cp, (u_char *)bp, buflen)) < 0) break; cp += n; host.h_name = bp; return(&host); } if (iquery || type != T_A) { #ifdef DEBUG if (_res.options & RES_DEBUG) printf("unexpected answer type %d, size %d\n", type, n); #endif cp += n; continue; } if (haveanswer) { if (n != host.h_length) { cp += n; continue; } if (class != getclass) { cp += n; continue; } } else { host.h_length = n; getclass = class; host.h_addrtype = (class == C_IN) ? AF_INET : AF_UNSPEC; if (!iquery) { host.h_name = bp; bp += strlen(bp) + 1; } } bp += sizeof(align) - ((u_int32_t)bp % sizeof(align)); if (bp + n >= &hostbuf[sizeof(hostbuf)]) { #ifdef DEBUG if (_res.options & RES_DEBUG) printf("size (%d) too big\n", n); #endif break; } bcopy(cp, *hap++ = bp, n); bp +=n; cp += n; haveanswer++; } if (haveanswer) { *ap = NULL; #if BSD >= 43 || defined(h_addr) /* new-style hostent structure */ *hap = NULL; #else host.h_addr = h_addr_ptrs[0]; #endif return (&host); } else { h_errno = TRY_AGAIN; return ((struct hostent *) NULL); } } struct hostent * _getdnsbyname(name) const char *name; { querybuf buf; register const char *cp; int n; extern struct hostent *_gethtbyname(); /* * disallow names consisting only of digits/dots, unless * they end in a dot. */ if (isdigit(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_aton(name, &host_addr)) { h_errno = HOST_NOT_FOUND; return((struct hostent *) NULL); } host.h_name = (char *)name; host.h_aliases = host_aliases; host_aliases[0] = NULL; host.h_addrtype = AF_INET; host.h_length = sizeof(u_int32_t); h_addr_ptrs[0] = (char *)&host_addr; h_addr_ptrs[1] = (char *)0; #if BSD >= 43 || defined(h_addr) /* new-style hostent structure */ host.h_addr_list = h_addr_ptrs; #else host.h_addr = h_addr_ptrs[0]; #endif return (&host); } if (!isdigit(*cp) && *cp != '.') break; } if ((n = res_search(name, C_IN, T_A, buf.buf, sizeof(buf))) < 0) { #ifdef DEBUG if (_res.options & RES_DEBUG) printf("res_search failed\n"); #endif return ((struct hostent *) NULL); } return (getanswer(&buf, n, 0)); } struct hostent * _getdnsbyaddr(addr, len, type) const char *addr; int len, type; { int n; querybuf buf; register struct hostent *hp; char qbuf[MAXDNAME]; extern struct hostent *_gethtbyaddr(); if (type != AF_INET) return ((struct hostent *) NULL); (void)sprintf(qbuf, "%u.%u.%u.%u.in-addr.arpa", ((unsigned)addr[3] & 0xff), ((unsigned)addr[2] & 0xff), ((unsigned)addr[1] & 0xff), ((unsigned)addr[0] & 0xff)); n = res_query(qbuf, C_IN, T_PTR, (char *)&buf, sizeof(buf)); if (n < 0) { #ifdef DEBUG if (_res.options & RES_DEBUG) printf("res_query failed\n"); #endif return ((struct hostent *) NULL); } hp = getanswer(&buf, n, 1); if (hp == NULL) return ((struct hostent *) NULL); hp->h_addrtype = type; hp->h_length = len; h_addr_ptrs[0] = (char *)&host_addr; h_addr_ptrs[1] = (char *)0; host_addr = *(struct in_addr *)addr; #if BSD < 43 && !defined(h_addr) /* new-style hostent structure */ hp->h_addr = h_addr_ptrs[0]; #endif return(hp); } void _sethtent(f) int f; { if (hostf == NULL) hostf = fopen(_PATH_HOSTS, "r" ); else rewind(hostf); stayopen |= f; } void _endhtent() { if (hostf && !stayopen) { (void) fclose(hostf); hostf = NULL; } } struct hostent * _gethtent() { char *p; register char *cp, **q; if (hostf == NULL && (hostf = fopen(_PATH_HOSTS, "r" )) == NULL) return (NULL); again: if ((p = fgets(hostbuf, BUFSIZ, hostf)) == NULL) return (NULL); if (*p == '#') goto again; cp = strpbrk(p, "#\n"); if (cp == NULL) goto again; *cp = '\0'; cp = strpbrk(p, " \t"); if (cp == NULL) goto again; *cp++ = '\0'; /* THIS STUFF IS INTERNET SPECIFIC */ #if BSD >= 43 || defined(h_addr) /* new-style hostent structure */ host.h_addr_list = host_addrs; #endif host.h_addr = hostaddr; *((u_int32_t *)host.h_addr) = inet_addr(p); host.h_length = sizeof (u_int32_t); host.h_addrtype = AF_INET; while (*cp == ' ' || *cp == '\t') cp++; host.h_name = cp; q = host.h_aliases = host_aliases; cp = strpbrk(cp, " \t"); if (cp != NULL) *cp++ = '\0'; while (cp && *cp) { if (*cp == ' ' || *cp == '\t') { cp++; continue; } if (q < &host_aliases[MAXALIASES - 1]) *q++ = cp; cp = strpbrk(cp, " \t"); if (cp != NULL) *cp++ = '\0'; } *q = NULL; return (&host); } struct hostent * _gethtbyname(name) char *name; { register struct hostent *p; register char **cp; _sethtent(0); while (p = _gethtent()) { if (strcasecmp(p->h_name, name) == 0) break; for (cp = p->h_aliases; *cp != 0; cp++) if (strcasecmp(*cp, name) == 0) goto found; } found: _endhtent(); return (p); } struct hostent * _gethtbyaddr(addr, len, type) const char *addr; int len, type; { register struct hostent *p; _sethtent(0); while (p = _gethtent()) if (p->h_addrtype == type && !bcmp(p->h_addr, addr, len)) break; _endhtent(); return (p); } #ifdef YP struct hostent * _getnishost(name, map) char *name, *map; { register char *cp, *dp, **q; char *result; int resultlen; static struct hostent h; static char *domain = (char *)NULL; if (domain == (char *)NULL) if (yp_get_default_domain (&domain)) return ((struct hostent *)NULL); if (yp_match(domain, map, name, strlen(name), &result, &resultlen)) return ((struct hostent *)NULL); if (cp = index(result, '\n')) *cp = '\0'; cp = strpbrk(result, " \t"); *cp++ = '\0'; #if BSD >= 43 || defined(h_addr) /* new-style hostent structure */ h.h_addr_list = host_addrs; #endif h.h_addr = hostaddr; *((u_long *)h.h_addr) = inet_addr(result); h.h_length = sizeof(u_long); h.h_addrtype = AF_INET; while (*cp == ' ' || *cp == '\t') cp++; h.h_name = cp; q = h.h_aliases = host_aliases; cp = strpbrk(cp, " \t"); if (cp != NULL) *cp++ = '\0'; while (cp && *cp) { if (*cp == ' ' || *cp == '\t') { cp++; continue; } if (q < &host_aliases[MAXALIASES - 1]) *q++ = cp; cp = strpbrk(cp, " \t"); if (cp != NULL) *cp++ = '\0'; } *q = NULL; return (&h); } #endif /* YP */ struct hostent * gethostbyname(const char *name) { struct hostent *hp = 0; int nserv = 0; if(!service_done) { init_services(); } while(!hp) { switch(service_order[nserv]) { case SERVICE_NONE: return 0; case SERVICE_HOSTS: hp = _gethtbyname(name); break; case SERVICE_BIND: hp = _getdnsbyname(name); break; case SERVICE_NIS: #ifdef YP hp = _getnishost(name, "hosts.byname"); #endif break; } nserv++; } return hp; } struct hostent * gethostbyaddr(const char *addr, int len, int type) { struct hostent *hp = 0; int nserv = 0; if(!service_done) { init_services(); } while(!hp) { switch(service_order[nserv]) { case SERVICE_NONE: return 0; case SERVICE_HOSTS: hp = _gethtbyaddr(addr, len, type); break; case SERVICE_BIND: hp = _getdnsbyname(addr, len, type); break; case SERVICE_NIS: #ifdef YP hp = _getnishost(addr, "hosts.byaddr"); #endif break; } nserv++; } return hp; }