/* $OpenBSD: getnetnamadr.c,v 1.26 2005/08/06 20:30:03 espie Exp $ */ /* * Copyright (c) 1997, Jason Downs. 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. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``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 AUTHOR(S) 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. */ /* Copyright (c) 1993 Carlos Leandro and Rui Salgueiro * Dep. Matematica Universidade de Coimbra, Portugal, Europe * * 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. */ /* * Copyright (c) 1983, 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. 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. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include "thread_private.h" extern int h_errno; struct netent *_getnetbyaddr(in_addr_t net, int type); struct netent *_getnetbyname(const char *name); int _hokchar(const char *); #define BYADDR 0 #define BYNAME 1 #define MAXALIASES 35 #define MAXPACKET (64*1024) typedef union { HEADER hdr; u_char buf[MAXPACKET]; } querybuf; typedef union { long al; char ac; } align; static struct netent * getnetanswer(querybuf *answer, int anslen, int net_i) { HEADER *hp; u_char *cp; int n; u_char *eom; int type, class, ancount, qdcount, haveanswer, i, nchar; char aux1[MAXHOSTNAMELEN], aux2[MAXHOSTNAMELEN], ans[MAXHOSTNAMELEN]; char *in, *st, *pauxt, *bp, **ap, *ep; char *paux1 = &aux1[0], *paux2 = &aux2[0]; static struct netent net_entry; static char *net_aliases[MAXALIASES], netbuf[BUFSIZ+1]; /* * find first satisfactory answer * * answer --> +------------+ ( MESSAGE ) * | Header | * +------------+ * | Question | the question for the name server * +------------+ * | Answer | RRs answering the question * +------------+ * | Authority | RRs pointing toward an authority * | Additional | RRs holding additional information * +------------+ */ eom = answer->buf + anslen; hp = &answer->hdr; ancount = ntohs(hp->ancount); /* #/records in the answer section */ qdcount = ntohs(hp->qdcount); /* #/entries in the question section */ bp = netbuf; ep = netbuf + sizeof(netbuf); cp = answer->buf + HFIXEDSZ; if (!qdcount) { if (hp->aa) h_errno = HOST_NOT_FOUND; else h_errno = TRY_AGAIN; return (NULL); } while (qdcount-- > 0) { n = __dn_skipname(cp, eom); if (n < 0 || (cp + n + QFIXEDSZ) > eom) { h_errno = NO_RECOVERY; return(NULL); } cp += n + QFIXEDSZ; } ap = net_aliases; *ap = NULL; net_entry.n_aliases = net_aliases; haveanswer = 0; while (--ancount >= 0 && cp < eom) { n = dn_expand(answer->buf, eom, cp, bp, ep - bp); #ifdef USE_RESOLV_NAME_OK if ((n < 0) || !res_dnok(bp)) #else if ((n < 0) || !_hokchar(bp)) #endif break; cp += n; ans[0] = '\0'; strlcpy(&ans[0], bp, sizeof ans); GETSHORT(type, cp); GETSHORT(class, cp); cp += INT32SZ; /* TTL */ GETSHORT(n, cp); if (class == C_IN && type == T_PTR) { n = dn_expand(answer->buf, eom, cp, bp, ep - bp); #ifdef USE_RESOLV_NAME_OK if ((n < 0) || !res_hnok(bp)) #else if ((n < 0) || !_hokchar(bp)) #endif { cp += n; return (NULL); } cp += n; if ((ap + 2) < &net_aliases[MAXALIASES]) { *ap++ = bp; bp += strlen(bp) + 1; net_entry.n_addrtype = (class == C_IN) ? AF_INET : AF_UNSPEC; haveanswer++; } } } if (haveanswer) { *ap = NULL; switch (net_i) { case BYADDR: net_entry.n_name = *net_entry.n_aliases; net_entry.n_net = 0L; break; case BYNAME: ap = net_entry.n_aliases; next_alias: in = *ap++; if (in == NULL) { h_errno = HOST_NOT_FOUND; return (NULL); } net_entry.n_name = ans; aux2[0] = '\0'; for (i = 0; i < 4; i++) { for (st = in, nchar = 0; isdigit((unsigned char)*st); st++, nchar++) ; if (*st != '.' || nchar == 0 || nchar > 3) goto next_alias; if (i != 0) nchar++; strlcpy(paux1, in, nchar+1); strlcat(paux1, paux2, MAXHOSTNAMELEN); pauxt = paux2; paux2 = paux1; paux1 = pauxt; in = ++st; } if (strcasecmp(in, "IN-ADDR.ARPA") != 0) goto next_alias; net_entry.n_net = inet_network(paux2); break; } net_entry.n_aliases++; return (&net_entry); } h_errno = TRY_AGAIN; return (NULL); } struct netent * getnetbyaddr(in_addr_t net, int net_type) { struct __res_state *_resp = _THREAD_PRIVATE(_res, _res, &_res); unsigned int netbr[4]; int nn, anslen; querybuf *buf; char qbuf[MAXDNAME]; in_addr_t net2; struct netent *net_entry = NULL; char lookups[MAXDNSLUS]; int i; if (_res_init(0) == -1) return(_getnetbyaddr(net, net_type)); bcopy(_resp->lookups, lookups, sizeof lookups); if (lookups[0] == '\0') strlcpy(lookups, "bf", sizeof lookups); for (i = 0; i < MAXDNSLUS && lookups[i]; i++) { switch (lookups[i]) { #ifdef YP case 'y': /* There is no YP support. */ break; #endif /* YP */ case 'b': if (net_type != AF_INET) break; /* DNS only supports AF_INET? */ for (nn = 4, net2 = net; net2; net2 >>= 8) netbr[--nn] = net2 & 0xff; switch (nn) { case 3: /* Class A */ snprintf(qbuf, sizeof(qbuf), "0.0.0.%u.in-addr.arpa", netbr[3]); break; case 2: /* Class B */ snprintf(qbuf, sizeof(qbuf), "0.0.%u.%u.in-addr.arpa", netbr[3], netbr[2]); break; case 1: /* Class C */ snprintf(qbuf, sizeof(qbuf), "0.%u.%u.%u.in-addr.arpa", netbr[3], netbr[2], netbr[1]); break; case 0: /* Class D - E */ snprintf(qbuf, sizeof(qbuf), "%u.%u.%u.%u.in-addr.arpa", netbr[3], netbr[2], netbr[1], netbr[0]); break; } buf = malloc(sizeof(*buf)); if (buf == NULL) break; anslen = res_query(qbuf, C_IN, T_PTR, buf->buf, sizeof(buf->buf)); if (anslen < 0) { free(buf); #ifdef DEBUG if (_resp->options & RES_DEBUG) printf("res_query failed\n"); #endif break; } net_entry = getnetanswer(buf, anslen, BYADDR); free(buf); if (net_entry != NULL) { unsigned u_net = net; /* maybe net should be unsigned ? */ /* Strip trailing zeros */ while ((u_net & 0xff) == 0 && u_net != 0) u_net >>= 8; net_entry->n_net = u_net; return (net_entry); } break; case 'f': net_entry = _getnetbyaddr(net, net_type); if (net_entry != NULL) return (net_entry); } } /* Nothing matched. */ return (NULL); } struct netent * getnetbyname(const char *net) { struct __res_state *_resp = _THREAD_PRIVATE(_res, _res, &_res); int anslen; querybuf *buf; char qbuf[MAXDNAME]; struct netent *net_entry = NULL; char lookups[MAXDNSLUS]; int i; if (_res_init(0) == -1) return (_getnetbyname(net)); bcopy(_resp->lookups, lookups, sizeof lookups); if (lookups[0] == '\0') strlcpy(lookups, "bf", sizeof lookups); for (i = 0; i < MAXDNSLUS && lookups[i]; i++) { switch (lookups[i]) { #ifdef YP case 'y': /* There is no YP support. */ break; #endif /* YP */ case 'b': strlcpy(qbuf, net, sizeof qbuf); buf = malloc(sizeof(*buf)); if (buf == NULL) break; anslen = res_search(qbuf, C_IN, T_PTR, buf->buf, sizeof(buf->buf)); if (anslen < 0) { free(buf); #ifdef DEBUG if (_resp->options & RES_DEBUG) printf("res_query failed\n"); #endif break; } net_entry = getnetanswer(buf, anslen, BYNAME); free(buf); if (net_entry != NULL) return (net_entry); break; case 'f': net_entry = _getnetbyname(net); if (net_entry != NULL) return (net_entry); break; } } /* Nothing matched. */ return (NULL); }