/* $OpenBSD: getinfo.c,v 1.4 1998/09/03 02:01:39 deraadt Exp $ */ /* * ++Copyright++ 1985, 1989 * - * Copyright (c) 1985, 1989 * 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-- */ #ifndef lint #if 0 static char sccsid[] = "@(#)getinfo.c 5.26 (Berkeley) 3/21/91"; static char rcsid[] = "$From: getinfo.c,v 8.6 1996/12/02 09:17:24 vixie Exp $"; #else static char rcsid[] = "$OpenBSD: getinfo.c,v 1.4 1998/09/03 02:01:39 deraadt Exp $"; #endif #endif /* not lint */ /* ****************************************************************************** * * getinfo.c -- * * Routines to create requests to name servers * and interpret the answers. * * Adapted from 4.3BSD BIND gethostnamadr.c * ****************************************************************************** */ #include #include #include #include #include #include #include #include #include "res.h" #include "conf/portability.h" extern char *_res_resultcodes[]; extern char *res_skip(); static char *addr_list[MAXADDRS + 1]; static char *host_aliases[MAXALIASES]; static int host_aliases_len[MAXALIASES]; static u_char hostbuf[BUFSIZ+1]; typedef struct { char *name; char *domain[MAXDOMAINS]; int numDomains; char *address[MAXADDRS]; int numAddresses; } ServerTable; ServerTable server[MAXSERVERS]; typedef union { HEADER qb1; u_char qb2[PACKETSZ*2]; } querybuf; typedef union { int32_t al; char ac; } align; #define GetShort(cp) _getshort(cp); cp += INT16SZ; /* ****************************************************************************** * * GetAnswer -- * * Interprets an answer packet and retrieves the following * information: * * Results: * SUCCESS the info was retrieved. * NO_INFO the packet did not contain an answer. * NONAUTH non-authoritative information was found. * ERROR the answer was malformed. * Other errors returned in the packet header. * ****************************************************************************** */ static int GetAnswer(nsAddrPtr, queryType, msg, msglen, iquery, hostPtr, isServer) struct in_addr *nsAddrPtr; char *msg; int queryType; int msglen; Boolean iquery; register HostInfo *hostPtr; Boolean isServer; { register HEADER *headerPtr; register u_char *cp; querybuf answer; char **aliasPtr; u_char *eom, *bp; char **addrPtr; char *namePtr; char *dnamePtr; int type, class; int qdcount, ancount, arcount, nscount, buflen; int origClass; int numAliases = 0; int numAddresses = 0; int n, i, j; int len; int dlen; int status; int numServers; Boolean haveAnswer; Boolean printedAnswers = FALSE; /* * If the hostPtr was used before, free up the calloc'd areas. */ FreeHostInfoPtr(hostPtr); status = SendRequest(nsAddrPtr, msg, msglen, (char *) &answer, sizeof(answer), &n); if (status != SUCCESS) { if (_res.options & RES_DEBUG2) printf("SendRequest failed\n"); return (status); } if (n > sizeof(answer)) { if (_res.options & RES_DEBUG2) printf("SendRequest overflowed\n"); return (-1); } eom = (u_char *) &answer + n; headerPtr = (HEADER *) &answer; if (headerPtr->rcode != NOERROR) { return (headerPtr->rcode); } qdcount = ntohs(headerPtr->qdcount); ancount = ntohs(headerPtr->ancount); arcount = ntohs(headerPtr->arcount); nscount = ntohs(headerPtr->nscount); /* * If there are no answer, n.s. or additional records * then return with an error. */ if (ancount == 0 && nscount == 0 && arcount == 0) { return (NO_INFO); } bp = hostbuf; buflen = sizeof(hostbuf); cp = (u_char *) &answer + HFIXEDSZ; /* Skip over question section. */ while (qdcount-- > 0) { cp += dn_skipname(cp, eom) + QFIXEDSZ; } aliasPtr = host_aliases; addrPtr = addr_list; haveAnswer = FALSE; /* * Scan through the answer resource records. * Answers for address query types are saved. * Other query type answers are just printed. */ if (ancount != 0) { if (!isServer && !headerPtr->aa) { printf("Non-authoritative answer:\n"); } if (queryType != T_A && !(iquery && queryType == T_PTR)) { while (--ancount >= 0 && cp < eom) { if ((cp = (u_char *)Print_rr(cp, (char *)&answer, eom, stdout)) == NULL) { return(ERROR); } } printedAnswers = TRUE; } else { while (--ancount >= 0 && cp < eom) { n = dn_expand(answer.qb2, eom, cp, (char *)bp, buflen); if (n < 0) { return(ERROR); } cp += n; type = GetShort(cp); class = GetShort(cp); cp += INT32SZ; /* skip TTL */ dlen = GetShort(cp); if (type == T_CNAME) { /* * Found an alias. */ cp += dlen; if (aliasPtr >= &host_aliases[MAXALIASES-1]) { continue; } *aliasPtr++ = (char *)bp; n = strlen((char *)bp) + 1; host_aliases_len[numAliases] = n; numAliases++; bp += n; buflen -= n; continue; } else if (type == T_PTR) { /* * Found a "pointer" to the real name. */ n = dn_expand(answer.qb2, eom, cp, (char *)bp, buflen); if (n < 0) { cp += n; continue; } cp += n; len = strlen((char *)bp) + 1; hostPtr->name = Calloc(1, len); bcopy(bp, hostPtr->name, len); haveAnswer = TRUE; break; } else if (type != T_A) { cp += dlen; continue; } if (haveAnswer) { /* * If we've already got 1 address, we aren't interested * in addresses with a different length or class. */ if (dlen != hostPtr->addrLen) { cp += dlen; continue; } if (class != origClass) { cp += dlen; continue; } } else { /* * First address: record its length and class so we * only save additonal ones with the same attributes. */ hostPtr->addrLen = dlen; origClass = class; hostPtr->addrType = (class == C_IN) ? AF_INET : AF_UNSPEC; len = strlen((char *)bp) + 1; hostPtr->name = Calloc(1, len); bcopy(bp, hostPtr->name, len); } bp += (((u_long)bp) % sizeof(align)); if (bp + dlen >= &hostbuf[sizeof(hostbuf)]) { if (_res.options & RES_DEBUG) { printf("Size (%d) too big\n", dlen); } break; } if (numAddresses >= MAXADDRS) { printf("MAXADDRS exceeded: skipping address\n"); cp += dlen; continue; } bcopy(cp, *addrPtr++ = (char *)bp, dlen); bp +=dlen; cp += dlen; numAddresses++; haveAnswer = TRUE; } } } if ((queryType == T_A || queryType == T_PTR) && haveAnswer) { /* * Go through the alias and address lists and return them * in the hostPtr variable. */ if (numAliases > 0) { hostPtr->aliases = (char **) Calloc(1 + numAliases, sizeof(char *)); for (i = 0; i < numAliases; i++) { hostPtr->aliases[i] = Calloc(1, host_aliases_len[i]); bcopy(host_aliases[i], hostPtr->aliases[i], host_aliases_len[i]); } hostPtr->aliases[i] = NULL; } if (numAddresses > 0) { hostPtr->addrList = (char **)Calloc(1+numAddresses, sizeof(char *)); for (i = 0; i < numAddresses; i++) { hostPtr->addrList[i] = Calloc(1, hostPtr->addrLen); bcopy(addr_list[i], hostPtr->addrList[i], hostPtr->addrLen); } hostPtr->addrList[i] = NULL; } #ifdef verbose if (headerPtr->aa || nscount == 0) { hostPtr->servers = NULL; return (SUCCESS); } #else hostPtr->servers = NULL; return (SUCCESS); #endif } /* * At this point, for the T_A query type, only empty answers remain. * For other query types, additional information might be found * in the additional resource records part. */ if (!headerPtr->aa && (queryType != T_A) && (nscount > 0 || arcount > 0)) { if (printedAnswers) { putchar('\n'); } printf("Authoritative answers can be found from:\n"); } cp = (u_char *)res_skip((char *) &answer, 2, eom); numServers = 0; if (queryType != T_A) { /* * If we don't need to save the record, just print it. */ while (--nscount >= 0 && cp < eom) { if ((cp = (u_char *)Print_rr(cp, (char *) &answer, eom, stdout)) == NULL) { return(ERROR); } } } else { while (--nscount >= 0 && cp < eom) { /* * Go through the NS records and retrieve the names of hosts * that serve the requested domain. */ n = dn_expand(answer.qb2, eom, cp, (char *)bp, buflen); if (n < 0) { return(ERROR); } cp += n; len = strlen((char *)bp) + 1; dnamePtr = Calloc(1, len); /* domain name */ bcopy(bp, dnamePtr, len); type = GetShort(cp); class = GetShort(cp); cp += INT32SZ; /* skip TTL */ dlen = GetShort(cp); if (type != T_NS) { cp += dlen; } else { Boolean found; n = dn_expand(answer.qb2, eom, cp, (char *)bp, buflen); if (n < 0) { return(ERROR); } cp += n; len = strlen((char *)bp) + 1; namePtr = Calloc(1, len); /* server host name */ bcopy(bp, namePtr, len); /* * Store the information keyed by the server host name. */ found = FALSE; for (j = 0; j < numServers; j++) { if (strcmp(namePtr, server[j].name) == 0) { found = TRUE; free(namePtr); break; } } if (found) { server[j].numDomains++; if (server[j].numDomains <= MAXDOMAINS) { server[j].domain[server[j].numDomains-1] = dnamePtr; } } else { if (numServers >= MAXSERVERS) { break; } server[numServers].name = namePtr; server[numServers].domain[0] = dnamePtr; server[numServers].numDomains = 1; server[numServers].numAddresses = 0; numServers++; } } } } /* * Additional resource records contain addresses of servers. */ cp = (u_char *)res_skip((char *) &answer, 3, eom); if (queryType != T_A) { /* * If we don't need to save the record, just print it. */ while (--arcount >= 0 && cp < eom) { if ((cp = (u_char *)Print_rr(cp, (char *) &answer, eom, stdout)) == NULL) { return(ERROR); } } } else { while (--arcount >= 0 && cp < eom) { n = dn_expand(answer.qb2, eom, cp, (char *)bp, buflen); if (n < 0) { break; } cp += n; type = GetShort(cp); class = GetShort(cp); cp += INT32SZ; /* skip TTL */ dlen = GetShort(cp); if (type != T_A) { cp += dlen; continue; } else { for (j = 0; j < numServers; j++) { if (strcmp((char *)bp, server[j].name) == 0) { server[j].numAddresses++; if (server[j].numAddresses <= MAXADDRS) { server[j].address[server[j].numAddresses-1] = Calloc(1,dlen); bcopy(cp, server[j].address[server[j].numAddresses-1],dlen); break; } } } cp += dlen; } } } /* * If we are returning name server info, transfer it to the hostPtr. */ if (numServers > 0) { hostPtr->servers = (ServerInfo **) Calloc(numServers+1, sizeof(ServerInfo *)); for (i = 0; i < numServers; i++) { hostPtr->servers[i] = (ServerInfo *) Calloc(1, sizeof(ServerInfo)); hostPtr->servers[i]->name = server[i].name; hostPtr->servers[i]->domains = (char **) Calloc(server[i].numDomains+1,sizeof(char *)); for (j = 0; j < server[i].numDomains; j++) { hostPtr->servers[i]->domains[j] = server[i].domain[j]; } hostPtr->servers[i]->domains[j] = NULL; hostPtr->servers[i]->addrList = (char **) Calloc(server[i].numAddresses+1,sizeof(char *)); for (j = 0; j < server[i].numAddresses; j++) { hostPtr->servers[i]->addrList[j] = server[i].address[j]; } hostPtr->servers[i]->addrList[j] = NULL; } hostPtr->servers[i] = NULL; } switch (queryType) { case T_A: return NONAUTH; case T_PTR: if (iquery) return NO_INFO; /* fall through */ default: return SUCCESS; } } /* ******************************************************************************* * * GetHostInfo -- * * Retrieves host name, address and alias information * for a domain. * * Algorithm from res_search(). * * Results: * ERROR - res_mkquery failed. * + return values from GetAnswer() * ******************************************************************************* */ int GetHostInfoByName(nsAddrPtr, queryClass, queryType, name, hostPtr, isServer) struct in_addr *nsAddrPtr; int queryClass; int queryType; char *name; HostInfo *hostPtr; Boolean isServer; { int n; register int result; register char **domain; const char *cp; Boolean got_nodata = FALSE; struct in_addr ina; Boolean tried_as_is = FALSE; /* Catch explicit addresses */ if ((queryType == T_A) && IsAddr(name, &ina)) { hostPtr->name = Calloc(strlen(name)+3, 1); (void)sprintf(hostPtr->name,"[%s]",name); hostPtr->aliases = NULL; hostPtr->servers = NULL; hostPtr->addrType = AF_INET; hostPtr->addrLen = INADDRSZ; hostPtr->addrList = (char **)Calloc(2, sizeof(char *)); hostPtr->addrList[0] = Calloc(INT32SZ, sizeof(char)); bcopy((char *)&ina, hostPtr->addrList[0], INADDRSZ); hostPtr->addrList[1] = NULL; return(SUCCESS); } result = NXDOMAIN; for (cp = name, n = 0; *cp; cp++) if (*cp == '.') n++; if (n == 0 && (cp = hostalias(name))) { printf("Aliased to \"%s\"\n\n", cp); return (GetHostDomain(nsAddrPtr, queryClass, queryType, cp, (char *)NULL, hostPtr, isServer)); } /* * If there are dots in the name already, let's just give it a try * 'as is'. The threshold can be set with the "ndots" option. */ if (n >= (int)_res.ndots) { result = GetHostDomain(nsAddrPtr, queryClass, queryType, name, (char *)NULL, hostPtr, isServer); if (result == SUCCESS) return (result); if (result == NO_INFO) got_nodata++; tried_as_is++; } /* * We do at least one level of search if * - there is no dot and RES_DEFNAME is set, or * - there is at least one dot, there is no trailing dot, * and RES_DNSRCH is set. */ if ((n == 0 && _res.options & RES_DEFNAMES) || (n != 0 && *--cp != '.' && _res.options & RES_DNSRCH)) for (domain = _res.dnsrch; *domain; domain++) { result = GetHostDomain(nsAddrPtr, queryClass, queryType, name, *domain, hostPtr, isServer); /* * If no server present, give up. * If name isn't found in this domain, * keep trying higher domains in the search list * (if that's enabled). * On a NO_INFO error, keep trying, otherwise * a wildcard entry of another type could keep us * from finding this entry higher in the domain. * If we get some other error (negative answer or * server failure), then stop searching up, * but try the input name below in case it's fully-qualified. */ if (result == SUCCESS || result == NO_RESPONSE) return result; if (result == NO_INFO) got_nodata++; if ((result != NXDOMAIN && result != NO_INFO) || (_res.options & RES_DNSRCH) == 0) break; } /* if we have not already tried the name "as is", do that now. * note that we do this regardless of how many dots were in the * name or whether it ends with a dot. */ if (!tried_as_is && (result = GetHostDomain(nsAddrPtr, queryClass, queryType, name, (char *)NULL, hostPtr, isServer) ) == SUCCESS) return (result); if (got_nodata) result = NO_INFO; return (result); } /* * Perform a query on the concatenation of name and domain, * removing a trailing dot from name if domain is NULL. */ GetHostDomain(nsAddrPtr, queryClass, queryType, name, domain, hostPtr, isServer) struct in_addr *nsAddrPtr; int queryClass; int queryType; char *name, *domain; HostInfo *hostPtr; Boolean isServer; { querybuf buf; char nbuf[2*MAXDNAME+2]; char *longname = nbuf; int n; if (domain == NULL) { /* * Check for trailing '.'; * copy without '.' if present. */ n = strlen(name) - 1; if (name[n] == '.' && n < sizeof(nbuf) - 1) { bcopy(name, nbuf, n); nbuf[n] = '\0'; } else longname = name; } else { (void)sprintf(nbuf, "%.*s.%.*s", MAXDNAME, name, MAXDNAME, domain); longname = nbuf; } n = res_mkquery(QUERY, longname, queryClass, queryType, NULL, 0, 0, buf.qb2, sizeof(buf)); if (n < 0) { if (_res.options & RES_DEBUG) { printf("Res_mkquery failed\n"); } return (ERROR); } n = GetAnswer(nsAddrPtr, queryType, (char *)&buf, n, 0, hostPtr, isServer); /* * GetAnswer didn't find a name, so set it to the specified one. */ if (n == NONAUTH) { if (hostPtr->name == NULL) { int len = strlen(longname) + 1; hostPtr->name = Calloc(len, sizeof(char)); bcopy(longname, hostPtr->name, len); } } return(n); } /* ******************************************************************************* * * GetHostInfoByAddr -- * * Performs a PTR lookup in in-addr.arpa to find the host name * that corresponds to the given address. * * Results: * ERROR - res_mkquery failed. * + return values from GetAnswer() * ******************************************************************************* */ int GetHostInfoByAddr(nsAddrPtr, address, hostPtr) struct in_addr *nsAddrPtr; struct in_addr *address; HostInfo *hostPtr; { int n; querybuf buf; char qbuf[MAXDNAME]; char *p = (char *) &address->s_addr; (void)sprintf(qbuf, "%u.%u.%u.%u.in-addr.arpa", ((unsigned)p[3] & 0xff), ((unsigned)p[2] & 0xff), ((unsigned)p[1] & 0xff), ((unsigned)p[0] & 0xff)); n = res_mkquery(QUERY, qbuf, C_IN, T_PTR, NULL, 0, NULL, buf.qb2, sizeof buf); if (n < 0) { if (_res.options & RES_DEBUG) { printf("res_mkquery() failed\n"); } return (ERROR); } n = GetAnswer(nsAddrPtr, T_PTR, (char *) &buf, n, 1, hostPtr, 1); if (n == SUCCESS) { hostPtr->addrType = AF_INET; hostPtr->addrLen = 4; hostPtr->addrList = (char **)Calloc(2, sizeof(char *)); hostPtr->addrList[0] = Calloc(INT32SZ, sizeof(char)); bcopy((char *)p, hostPtr->addrList[0], INADDRSZ); hostPtr->addrList[1] = NULL; } return n; } /* ******************************************************************************* * * FreeHostInfoPtr -- * * Deallocates all the calloc'd areas for a HostInfo variable. * ******************************************************************************* */ void FreeHostInfoPtr(hostPtr) register HostInfo *hostPtr; { int i, j; if (hostPtr->name != NULL) { free(hostPtr->name); hostPtr->name = NULL; } if (hostPtr->aliases != NULL) { i = 0; while (hostPtr->aliases[i] != NULL) { free(hostPtr->aliases[i]); i++; } free((char *)hostPtr->aliases); hostPtr->aliases = NULL; } if (hostPtr->addrList != NULL) { i = 0; while (hostPtr->addrList[i] != NULL) { free(hostPtr->addrList[i]); i++; } free((char *)hostPtr->addrList); hostPtr->addrList = NULL; } if (hostPtr->servers != NULL) { i = 0; while (hostPtr->servers[i] != NULL) { if (hostPtr->servers[i]->name != NULL) { free(hostPtr->servers[i]->name); } if (hostPtr->servers[i]->domains != NULL) { j = 0; while (hostPtr->servers[i]->domains[j] != NULL) { free(hostPtr->servers[i]->domains[j]); j++; } free((char *)hostPtr->servers[i]->domains); } if (hostPtr->servers[i]->addrList != NULL) { j = 0; while (hostPtr->servers[i]->addrList[j] != NULL) { free(hostPtr->servers[i]->addrList[j]); j++; } free((char *)hostPtr->servers[i]->addrList); } free((char *)hostPtr->servers[i]); i++; } free((char *)hostPtr->servers); hostPtr->servers = NULL; } }