/* * Copyright (c) 1986 Regents of the University of California * All Rights Reserved * * Redistribution and use in source and binary forms are permitted * provided that this notice is preserved and that due credit is given * to the University of California at Berkeley. The name of the University * may not be used to endorse or promote products derived from this * software without specific prior written permission. This software * is provided ``as is'' without express or implied warranty. */ /* * Actually, this program is from Rutgers University, however it is * based on nslookup and other pieces of named tools, so it needs * that copyright notice. */ #include #include #include #include #include #include #include #include #include #include extern int h_errno; #define NUMMX 50 #define SUCCESS 0 #define TIME_OUT -1 #define NO_INFO -2 #define ERROR -3 #define NONAUTH -4 #define NAME_LEN 256 #ifndef T_TXT #define T_TXT 16 #endif #ifndef NO_DATA #define NO_DATA NO_ADDRESS #endif #ifndef C_HS #define C_HS 4 #endif #define NDB "/afs/net.mit.edu/admin/hosts/mit.zone" #define NDB_DOMAIN "MIT.EDU" int sockFD; FILE *filePtr; char *DecodeError(); #ifdef sgi struct __res_state orig; extern struct __res_state _res; #else struct state orig; extern struct state _res; #endif static char *cname = NULL; extern char *inet_ntoa(); char *desired_host; extern u_long inet_addr(); int getclass = C_IN; int gettype = 0; int verbose = 0; int cname_srch = 0; int list = 0; int server_specified = 0; char *pr_class(); char *pr_rr(); char *pr_cdname(); char *pr_type(); main(c, v) char **v; { unsigned addr; register struct hostent *hp; register char *s; register inverse = 0; register waitmode = 0; char *oldcname; int ncnames; res_init(); /* _res.retrans = 2; _res.retry = 1; */ if (c < 2) { fprintf(stderr, "Usage: host [-w] [-v] [-r] [-d] [-t type] [-c class] [-a] [-s] host [server]\n -w to wait forever until reply\n -v for verbose output\n -r to disable recursive processing\n -d to turn on debugging output\n -t querytype to look for a specific type of information\n -c class to look for non-Internet data\n -a is equivalent to '-v -t *'\n -n to disable cname search\n"); exit(1); } while (c > 2 && v[1][0] == '-') { if (strcmp (v[1], "-w") == 0) { _res.retry = 1; _res.retrans = 15; waitmode = 1; v++; c--; } else if (strcmp (v[1], "-r") == 0) { _res.options &= ~RES_RECURSE; v++; c--; } else if (strcmp (v[1], "-d") == 0) { _res.options |= RES_DEBUG; v++; c--; } else if (strcmp (v[1], "-v") == 0) { verbose = 1; v++; c--; } else if (strcmp (v[1], "-l") == 0) { list = 1; v++; c--; } else if (strncmp (v[1], "-t", 2) == 0) { v++; c--; gettype = parsetype(v[1]); v++; c--; } else if (strncmp (v[1], "-c", 2) == 0) { v++; c--; getclass = parseclass(v[1]); v++; c--; } else if (strcmp (v[1], "-a") == 0) { verbose = 1; gettype = T_ANY; v++; c--; } else if (strcmp (v[1], "-s") == 0) { cname_srch = 1; v++; c--; } } if (c > 2) { s = v[2]; server_specified++; addr = inet_addr(s); if (addr == -1) { hp = gethostbyname(s); if (hp == NULL) { fprintf(stderr,"Error in looking up server name:\n"); hperror(h_errno); exit(1); } _res.nsaddr.sin_addr = *(struct in_addr *)hp->h_addr; printf("Using domain server:\n"); printanswer(hp); } else { _res.nsaddr.sin_family = AF_INET; _res.nsaddr.sin_addr.s_addr = addr; _res.nsaddr.sin_port = htons(NAMESERVER_PORT); printf("Using domain server %s:\n", inet_ntoa(_res.nsaddr.sin_addr)); } } desired_host = v[1]; if (strcmp (v[1], ".") == 0) addr = -1; else addr = inet_addr(v[1]); hp = NULL; h_errno = TRY_AGAIN; /* * we handle default domains ourselves, thank you */ _res.options &= ~RES_DEFNAMES; if (list) exit(ListHosts(v[1], gettype ? gettype : T_A)); oldcname = NULL; ncnames = 5; while (hp == NULL && h_errno == TRY_AGAIN) { if (addr == -1) { cname = NULL; if (oldcname == NULL) hp = (struct hostent *)gethostinfo(v[1]); else hp = (struct hostent *)gethostinfo(oldcname); if (cname) { if (ncnames-- == 0) { printf("Too many cnames. Possible loop.\n"); exit(1); } oldcname = cname; hp = NULL; h_errno = TRY_AGAIN; continue; } } if(hp == NULL) { hp = gethostbyaddr(&addr, 4, AF_INET); if (hp) printanswer(hp); } if (!waitmode) break; } if(!hp) { hperror(h_errno); exit(1); } exit(0); } parsetype(s) char *s; { if (strcmp(s,"a") == 0) return(1); if (strcmp(s,"ns") == 0) return(2); if (strcmp(s,"md") == 0) return(3); if (strcmp(s,"mf") == 0) return(4); if (strcmp(s,"cname") == 0) return(5); if (strcmp(s,"soa") == 0) return(6); if (strcmp(s,"mb") == 0) return(7); if (strcmp(s,"mg") == 0) return(8); if (strcmp(s,"mr") == 0) return(9); if (strcmp(s,"null") == 0) return(10); if (strcmp(s,"wks") == 0) return(11); if (strcmp(s,"ptr") == 0) return(12); if (strcmp(s,"hinfo") == 0) return(13); if (strcmp(s,"minfo") == 0) return(14); if (strcmp(s,"mx") == 0) return(15); if (strcmp(s,"txt") == 0) /* Roy */ return(T_TXT); /* Roy */ if (strcmp(s,"uinfo") == 0) return(100); if (strcmp(s,"uid") == 0) return(101); if (strcmp(s,"gid") == 0) return(102); if (strcmp(s,"unspec") == 0) return(103); if (strcmp(s,"any") == 0) return(255); if (strcmp(s,"*") == 0) return(255); if (atoi(s)) return(atoi(s)); fprintf(stderr, "Invalid query type: %s\n", s); exit(2); } parseclass(s) char *s; { if (strcmp(s,"in") == 0) return(C_IN); if (strcmp(s,"hs") == 0) return(C_HS); if (strcmp(s,"any") == 0) return(C_ANY); if (atoi(s)) return(atoi(s)); fprintf(stderr, "Invalid query class: %s\n", s); exit(2); } printanswer(hp) register struct hostent *hp; { register char **cp; register long **hptr; printf("Host name: %s\n", hp->h_name); printf("Host address: "); for (hptr = (long **)hp->h_addr_list; *hptr; hptr++) printf(" %s", inet_ntoa(*(struct in_addr *)*hptr)); if(hp->h_aliases && hp->h_aliases[0]) printf("\nAliases: "); for (cp = hp->h_aliases; cp && *cp && **cp; cp++) printf(" %s", *cp); printf("\n\n"); } hperror(errno) int errno; { switch(errno) { case HOST_NOT_FOUND: fprintf(stderr,"Host not found.\n"); break; case TRY_AGAIN: fprintf(stderr,"Host not found, try again.\n"); break; case NO_RECOVERY: fprintf(stderr,"No recovery, Host not found.\n"); break; case NO_ADDRESS: fprintf(stderr,"There is an entry for this host, but it doesn't have an Internet address.\n"); break; } } typedef union { HEADER qb1; char qb2[PACKETSZ]; } querybuf; static char hostbuf[BUFSIZ+1]; char *hostalias(); gethostinfo(name) char *name; { register char *cp, **domain; int n; int hp; #ifdef MAXDS int nDomain; #endif if (strcmp(name, ".") == 0) return(getdomaininfo(name, NULL)); for (cp = name, n = 0; *cp; cp++) if (*cp == '.') n++; if (n && cp[-1] == '.') { if (cp[-1] == '.') cp[-1] = 0; hp = getdomaininfo(name, (char *)NULL); if (cp[-1] == 0) cp[-1] = '.'; return (hp); } if (n == 0 && (cp = hostalias(name))) { if (verbose) printf("Aliased to \"%s\"\n", cp); else if(!verbose) printf("Alias: %s\n", cp); _res.options |= RES_DEFNAMES; return (getdomaininfo(cp, (char *)NULL)); } #ifdef MAXDS for (nDomain = 0; _res.defdname_list[nDomain][0] != 0; nDomain++) { for (domain = _res.dnsrch_list[nDomain]; *domain; domain++) { if (verbose) printf("Trying domain \"%s\"\n", *domain); hp = getdomaininfo(name, *domain); if (hp) return (hp); } } #else for (domain = _res.dnsrch; *domain; domain++) { if (verbose) printf("Trying domain \"%s\"\n", *domain); hp = getdomaininfo(name, *domain); if (hp) return (hp); } #endif if (h_errno != HOST_NOT_FOUND || (_res.options & RES_DNSRCH) == 0) return (NULL); if (verbose) printf("Trying null domain\n"); return (getdomaininfo(name, (char *)NULL)); } getdomaininfo(name, domain) char *name, *domain; { int val1, val2; if (gettype) return getinfo(name, domain, gettype); else { val1 = getinfo(name, domain, T_A); if (cname || verbose) return val1; if(val1 >= 0) val2 = getinfo(name, domain, T_HINFO); val2 = getinfo(name, domain, T_MX); return val1 || val2; } } getinfo(name, domain, type) char *name, *domain; { char *eom; querybuf buf, answer; int n; char host[2*MAXDNAME+2]; if (domain == NULL) (void)sprintf(host, "%.*s", MAXDNAME, name); else (void)sprintf(host, "%.*s.%.*s", MAXDNAME, name, MAXDNAME, domain); n = res_mkquery(QUERY, host, getclass, type, (char *)NULL, 0, NULL, (char *)&buf, sizeof(buf)); if (n < 0) { if (_res.options & RES_DEBUG) printf("res_mkquery failed\n"); h_errno = NO_RECOVERY; return(-1); } n = res_send((char *)&buf, n, (char *)&answer, sizeof(answer)); if (n < 0) { if (_res.options & RES_DEBUG) printf("res_send failed\n"); h_errno = TRY_AGAIN; return (-1); } eom = (char *)&answer + n; return(printinfo(&answer, eom, T_ANY, 0)); } printinfo(answer, eom, filter, isls) querybuf *answer; char *eom; int filter; int isls; { HEADER *hp; char *bp, *cp; int nmx, ancount, nscount, arcount, qdcount, buflen; /* * find first satisfactory answer */ hp = (HEADER *) answer; ancount = ntohs(hp->ancount); qdcount = ntohs(hp->qdcount); nscount = ntohs(hp->nscount); arcount = ntohs(hp->arcount); if (_res.options & RES_DEBUG || (verbose && isls == 0)) printf("rcode = %d (%s), ancount=%d\n", hp->rcode, DecodeError(hp->rcode), ancount); if (hp->rcode != NOERROR || (ancount+nscount+arcount) == 0) { switch (hp->rcode) { case NXDOMAIN: /* Check if it's an authoritive answer */ if (hp->aa) { h_errno = HOST_NOT_FOUND; return(0); } else { h_errno = TRY_AGAIN; return(0); } case SERVFAIL: h_errno = TRY_AGAIN; return(0); #ifdef OLDJEEVES /* * Jeeves (TOPS-20 server) still does not * support MX records. For the time being, * we must accept FORMERRs as the same as * NOERROR. */ case FORMERR: #endif /* OLDJEEVES */ case NOERROR: /* TpB - set a return error for this case. NO_DATA */ h_errno = NO_DATA; return(0); /* was 1,but now indicates exception */ #ifndef OLDJEEVES case FORMERR: #endif /* OLDJEEVES */ case NOTIMP: case REFUSED: h_errno = NO_RECOVERY; return(0); } return (0); } bp = hostbuf; nmx = 0; buflen = sizeof(hostbuf); cp = (char *)answer + sizeof(HEADER); if (qdcount) { cp += dn_skipname(cp,eom) + QFIXEDSZ; while (--qdcount > 0) cp += dn_skipname(cp,eom) + QFIXEDSZ; } if (ancount) { if (!hp->aa) if (verbose && isls == 0) printf("The following answer is not authoritative:\n"); while (--ancount >= 0 && cp && cp < eom) { cp = pr_rr(cp, answer, stdout, filter); /* * When we ask for address and there is a CNAME, it seems to return * both the CNAME and the address. Since we trace down the CNAME * chain ourselves, we don't really want to print the address at * this point. */ if(cname && !verbose) return(1); } } if (! verbose) return (1); if (nscount) { printf("For authoritative answers, see:\n"); while (--nscount >= 0 && cp && cp < eom) { cp = pr_rr(cp, answer, stdout, filter); } } if (arcount) { printf("Additional information:\n"); while (--arcount >= 0 && cp && cp < eom) { cp = pr_rr(cp, answer, stdout, filter); } } return(1); } static char cnamebuf[MAXDNAME]; /* * Print resource record fields in human readable form. */ char * pr_rr(cp, msg, file, filter) char *cp, *msg; FILE *file; int filter; { int type, class, dlen, n, c, proto, ttl; struct in_addr inaddr; char *cp1; struct protoent *protop; struct servent *servp; char punc; int doprint; char name[MAXDNAME]; static int already = 0; char *cn; if ((cp = pr_cdname(cp, msg, name, sizeof(name))) == NULL) return (NULL); /* compression error */ type = _getshort(cp); cp += sizeof(u_short); class = _getshort(cp); cp += sizeof(u_short); ttl = _getlong(cp); cp += sizeof(u_long); if (filter == type || filter == T_ANY || (filter == T_A && (type == T_PTR || type == T_NS))) doprint = 1; else doprint = 0; if (doprint) if (verbose) fprintf(file,"%s\t%d%s\t%s", name, ttl, pr_class(class), pr_type(type)); if(verbose) fprintf(file,"%s%s %s",name, pr_class(class), pr_type(type)); if (verbose) punc = '\t'; else punc = ' '; dlen = _getshort(cp); cp += sizeof(u_short); cp1 = cp; /* * Print type specific data, if appropriate */ switch (type) { case T_A: switch (class) { case C_IN: bcopy(cp, (char *)&inaddr, sizeof(inaddr)); if(doprint && !verbose) { if(!already) { fprintf(file, "Desired host: %s\n", desired_host); fprintf(file, "Official name: %s\n", name); if(!verbose && (cn = (char *) index(name, '.')) != (char *) NULL) { *cn++ = '\0'; if(cname_srch && (strcmp(cn, NDB_DOMAIN) == 0)) cname_search(name); } } already = 1; fprintf(file, "Host address: "); } if (dlen == 4) { if (doprint && verbose) fprintf(file,"%c%s", punc, inet_ntoa(inaddr)); else if(!verbose) fprintf(file,"%s",inet_ntoa(inaddr)); cp += dlen; } else if (dlen == 7) { if (doprint && verbose) { fprintf(file,"%c%s", punc, inet_ntoa(inaddr)); fprintf(file,", protocol = %d", cp[4]); fprintf(file,", port = %d", (cp[5] << 8) + cp[6]); } else if (!verbose) { fprintf(file,"%s", inet_ntoa(inaddr)); fprintf(file,", protocol = %d", cp[4]); fprintf(file,", port = %d", (cp[5] << 8) + cp[6]); } cp += dlen; } if(!verbose && doprint) fprintf(file, "\n"); break; } break; case T_CNAME: if (dn_expand(msg, msg + 512, cp, cnamebuf, sizeof(cnamebuf)) >= 0) cname = cnamebuf; case T_MB: #ifdef OLDRR case T_MD: case T_MF: #endif /* OLDRR */ case T_MG: case T_MR: case T_NS: case T_PTR: cp = pr_cdname(cp, msg, name, sizeof(name)); if(doprint) { if(verbose) fprintf(file,"%c%s",punc, name); } break; case T_HINFO: if (n = *cp++) { if(!verbose && doprint) fprintf(file, "Host info: %.*s", n, cp); else if (doprint) fprintf(file,"%c%.*s", punc, n, cp); cp += n; } if (n = *cp++) { if(!verbose && doprint) fprintf(file, "/%.*s\n", n, cp); else if (doprint) fprintf(file, "%c%.*s", punc, n, cp); cp += n; } break; case T_SOA: cp = pr_cdname(cp, msg, name, sizeof(name)); if (doprint) fprintf(file,"\t%s", name); cp = pr_cdname(cp, msg, name, sizeof(name)); if (doprint) fprintf(file," %s", name); if (doprint) fprintf(file,"(\n\t\t\t%ld\t;serial (version)", _getlong(cp)); cp += sizeof(u_long); if (doprint) fprintf(file,"\n\t\t\t%ld\t;refresh period", _getlong(cp)); cp += sizeof(u_long); if (doprint) fprintf(file,"\n\t\t\t%ld\t;retry refresh this often", _getlong(cp)); cp += sizeof(u_long); if (doprint) fprintf(file,"\n\t\t\t%ld\t;expiration period", _getlong(cp)); cp += sizeof(u_long); if (doprint) fprintf(file,"\n\t\t\t%ld\t;minimum TTL\n\t\t\t)", _getlong(cp)); cp += sizeof(u_long); break; case T_MX: if (doprint) if (verbose) fprintf(file,"\t%ld ",_getshort(cp)); else fprintf(file, "MX address: "); cp += sizeof(u_short); cp = pr_cdname(cp, msg, name, sizeof(name)); if (doprint) fprintf(file, "%s", name); if(!verbose && doprint) fprintf(file, "\n"); break; case T_MINFO: cp = pr_cdname(cp, msg, name, sizeof(name)); if (doprint) if (verbose) fprintf(file,"%c%s",punc, name); else fprintf(file, "Minfo: "); cp = pr_cdname(cp, msg, name, sizeof(name)); if (doprint) fprintf(file," %s", name); if(!verbose && doprint) fprintf(file, "\n"); break; /* Roy start */ case T_TXT: if (doprint && verbose) fprintf(file,"%c%.*s", punc, dlen, cp); else if(!verbose && doprint) fprintf(file, "Text: %.*s\n", dlen, cp); cp += dlen; break; /* Roy end */ case T_UINFO: if (doprint && verbose) fprintf(file,"%c%s", punc, cp); else if(!verbose && doprint) fprintf(file, "Uinfo: %.s\n", cp); cp += dlen; break; case T_UID: case T_GID: if (dlen == 4) { if (doprint && verbose) fprintf(file,"%c%ld", punc, _getlong(cp)); else if(!verbose && doprint) fprintf(file, "Uid: %ld\n", _getlong(cp)); cp += sizeof(int); } break; case T_WKS: if (dlen < sizeof(u_long) + 1) break; bcopy(cp, (char *)&inaddr, sizeof(inaddr)); cp += sizeof(u_long); proto = *cp++; protop = getprotobynumber(proto); if (doprint) if (protop) fprintf(file,"%c%s %s", punc, inet_ntoa(inaddr), protop->p_name); else fprintf(file,"%c%s %d", punc, inet_ntoa(inaddr), proto); n = 0; while (cp < cp1 + dlen) { c = *cp++; do { if (c & 0200) { servp = NULL; if (protop) servp = getservbyport (htons(n), protop->p_name); if (doprint) if (servp) fprintf(file, " %s", servp->s_name); else fprintf(file, " %d", n); } c <<= 1; } while (++n & 07); } break; default: if (doprint) fprintf(file,"%c???\n", punc); cp += dlen; } if (cp != cp1 + dlen) fprintf(file,"packet size error (%#x != %#x)\n", cp, cp1+dlen); if (doprint && verbose) fprintf(file,"\n"); return (cp); } static char nbuf[20]; /* * Return a string for the type */ char * pr_type(type) int type; { switch (type) { case T_A: return(verbose? "A" : "has address"); case T_NS: /* authoritative server */ return("NS"); #ifdef OLDRR case T_MD: /* mail destination */ return("MD"); case T_MF: /* mail forwarder */ return("MF"); #endif /* OLDRR */ case T_CNAME: /* connonical name */ return(verbose? "CNAME" : "is a nickname for"); case T_SOA: /* start of authority zone */ return("SOA"); case T_MB: /* mailbox domain name */ return("MB"); case T_MG: /* mail group member */ return("MG"); case T_MX: /* mail routing info */ return(verbose? "MX" : "mail is handled by"); /* Roy start */ case T_TXT: /* TXT - descriptive info */ return(verbose? "TXT" : "descriptive text"); /* Roy end */ case T_MR: /* mail rename name */ return("MR"); case T_NULL: /* null resource record */ return("NULL"); case T_WKS: /* well known service */ return("WKS"); case T_PTR: /* domain name pointer */ return("PTR"); case T_HINFO: /* host information */ return("HINFO"); case T_MINFO: /* mailbox information */ return("MINFO"); case T_AXFR: /* zone transfer */ return("AXFR"); case T_MAILB: /* mail box */ return("MAILB"); case T_MAILA: /* mail address */ return("MAILA"); case T_ANY: /* matches any type */ return("ANY"); case T_UINFO: return("UINFO"); case T_UID: return("UID"); case T_GID: return("GID"); default: sprintf(nbuf, "%d", type); return (nbuf); } } /* * Return a mnemonic for class */ char * pr_class(class) int class; { switch (class) { case C_IN: /* internet class */ return(verbose? " IN" : ""); case C_HS: /* internet class */ return(verbose? " HS" : ""); case C_ANY: /* matches any class */ return(" ANY"); default: sprintf(nbuf," %d", class); return (nbuf); } } char * pr_cdname(cp, msg, name, namelen) char *cp, *msg; char *name; int namelen; { int n; if ((n = dn_expand(msg, msg + 512, cp, name, namelen - 2)) < 0) return (NULL); if (name[0] == '\0') { name[0] = '.'; name[1] = '\0'; } return (cp + n); } char *resultcodes[] = { "NOERROR", "FORMERR", "SERVFAIL", "NXDOMAIN", "NOTIMP", "REFUSED", "6", "7", "8", "9", "10", "11", "12", "13", "14", "NOCHANGE", }; /* ****************************************************************************** * * ListHosts -- * * Requests the name server to do a zone transfer so we * find out what hosts it knows about. * * Results: * SUCCESS the listing was successful. * ERROR the server could not be contacted because * a socket could not be obtained or an error * occured while receiving, or the output file * could not be opened. * ****************************************************************************** */ int ListHosts(namePtr, queryType) char *namePtr; int queryType; /* e.g. T_A */ { querybuf buf, answer; struct sockaddr_in sin; HEADER *headerPtr; int msglen; int amtToRead; int numRead; int i; int numAnswers = 0; int result = 0; int soacnt = 0; u_short len; int dlen; int type; int nscount; char *cp, *nmp; char name[NAME_LEN]; char dname[2][NAME_LEN]; char domain[NAME_LEN]; /* names and addresses of name servers to try */ #define NUMNS 8 char nsname[NUMNS][NAME_LEN]; int nshaveaddr[NUMNS]; #define IPADDRSIZE 4 #define NUMNSADDR 16 char nsipaddr[NUMNSADDR][IPADDRSIZE]; int numns; int numnsaddr; int thisns; struct hostent *hp; enum { NO_ERRORS, ERR_READING_LEN, ERR_READING_MSG, ERR_PRINTING } error = NO_ERRORS; /* * normalize to not have trailing dot. We do string compares below * of info from name server, and it won't have trailing dots. */ i = strlen(namePtr); if (namePtr[i-1] == '.') namePtr[i-1] = 0; if (server_specified) { bcopy(&_res.nsaddr.sin_addr, nsipaddr[0], IPADDRSIZE); numnsaddr = 1; } else { /* * First we have to find out where to look. This needs a NS query, * possibly followed by looking up addresses for some of the names. */ msglen = res_mkquery(QUERY, namePtr, C_IN, T_NS, (char *)0, 0, (char *)0, (char *) &buf, sizeof(buf)); if (msglen < 0) { printf("res_mkquery failed\n"); return (ERROR); } msglen = res_send((char *)&buf,msglen,(char *)&answer, sizeof(answer)); if (msglen < 0) { printf("Unable to get to nameserver -- try again later\n"); return (ERROR); } if (_res.options & RES_DEBUG || verbose) printf("rcode = %d (%s), ancount=%d\n", answer.qb1.rcode, DecodeError(answer.qb1.rcode), ntohs(answer.qb1.ancount)); /* * Analyze response to our NS lookup */ nscount = ntohs(answer.qb1.ancount) + ntohs(answer.qb1.nscount) + ntohs(answer.qb1.arcount); if (answer.qb1.rcode != NOERROR || nscount == 0) { switch (answer.qb1.rcode) { case NXDOMAIN: /* Check if it's an authoritive answer */ if (answer.qb1.aa) { printf("No such domain\n"); } else { printf("Unable to get information about domain -- try again later.\n"); } break; case SERVFAIL: printf("Unable to get information about that domain -- try again later.\n"); break; case NOERROR: printf("That domain exists, but seems to be a leaf node.\n"); break; case FORMERR: case NOTIMP: case REFUSED: printf("Unrecoverable error looking up domain name.\n"); break; } return (0); } cp = answer.qb2 + sizeof(HEADER); if (ntohs(answer.qb1.qdcount) > 0) cp += dn_skipname(cp, answer.qb2 + msglen) + QFIXEDSZ; numns = 0; numnsaddr = 0; /* * Look at response from NS lookup for NS and A records. */ for (;nscount; nscount--) { cp += dn_expand(answer.qb2, answer.qb2 + msglen, cp, domain, sizeof(domain)); type = _getshort(cp); cp += sizeof(u_short) + sizeof(u_short) + sizeof(u_long); dlen = _getshort(cp); cp += sizeof(u_short); if (type == T_NS) { if (dn_expand(answer.qb2, answer.qb2 + msglen, cp, name, sizeof(name)) >= 0) { if (numns < NUMNS && strcasecmp(domain, namePtr) == 0) { for (i = 0; i < numns; i++) if (strcasecmp(nsname[i], name) == 0) break; /* duplicate */ if (i >= numns) { strncpy(nsname[numns], name, sizeof(name)); nshaveaddr[numns] = 0; numns++; } } } } else if (type == T_A) { if (numnsaddr < NUMNSADDR) for (i = 0; i < numns; i++) { if (strcasecmp(nsname[i], domain) == 0) { nshaveaddr[i]++; bcopy(cp, nsipaddr[numnsaddr],IPADDRSIZE); numnsaddr++; break; } } } cp += dlen; } /* * Usually we'll get addresses for all the servers in the additional * info section. But in case we don't, look up their addresses. */ for (i = 0; i < numns; i++) { if (! nshaveaddr[i]) { register long **hptr; int numaddrs = 0; hp = gethostbyname(nsname[i]); if (hp) { for (hptr = (long **)hp->h_addr_list; *hptr; hptr++) if (numnsaddr < NUMNSADDR) { bcopy((char *)*hptr, nsipaddr[numnsaddr],IPADDRSIZE); numnsaddr++; numaddrs++; } } if (_res.options & RES_DEBUG || verbose) printf("Found %d addresses for %s by extra query\n", numaddrs, nsname[i]); } else if (_res.options & RES_DEBUG || verbose) printf("Found %d addresses for %s\n", nshaveaddr[i], nsname[i]); } } /* * Now nsipaddr has numnsaddr addresses for name servers that * serve the requested domain. Now try to find one that will * accept a zone transfer. */ thisns = 0; again: numAnswers = 0; soacnt = 0; /* * Create a query packet for the requested domain name. * */ msglen = res_mkquery(QUERY, namePtr, getclass, T_AXFR, (char *)0, 0, (char *)0, (char *) &buf, sizeof(buf)); if (msglen < 0) { if (_res.options & RES_DEBUG) { fprintf(stderr, "ListHosts: Res_mkquery failed\n"); } return (ERROR); } bzero((char *)&sin, sizeof(sin)); sin.sin_family = AF_INET; sin.sin_port = htons(NAMESERVER_PORT); /* * Set up a virtual circuit to the server. */ for (;thisns < numnsaddr; thisns++) { if ((sockFD = socket(AF_INET, SOCK_STREAM, 0)) < 0) { perror("ListHosts"); return(ERROR); } bcopy(nsipaddr[thisns], &sin.sin_addr, IPADDRSIZE); if (_res.options & RES_DEBUG || verbose) printf("Trying %s\n", inet_ntoa(sin.sin_addr)); if (connect(sockFD, &sin, sizeof(sin)) >= 0) break; if (verbose) perror("Connection failed, trying next server"); (void) close(sockFD); sockFD = -1; } if (thisns >= numnsaddr) { printf("No server for that domain responded\n"); if (!verbose) perror("Error from the last server was"); return(ERROR); } /* * Send length & message for zone transfer */ len = htons(msglen); if (write(sockFD, (char *)&len, sizeof(len)) != sizeof(len) || write(sockFD, (char *) &buf, msglen) != msglen) { perror("ListHosts"); (void) close(sockFD); sockFD = -1; return(ERROR); } filePtr = stdout; while (1) { /* * Read the length of the response. */ cp = (char *) &buf; amtToRead = sizeof(u_short); while(amtToRead > 0 && (numRead = read(sockFD, cp, amtToRead)) > 0){ cp += numRead; amtToRead -= numRead; } if (numRead <= 0) { error = ERR_READING_LEN; break; } if ((len = htons(*(u_short *)&buf)) == 0) { break; /* nothing left to read */ } /* * Read the response. */ amtToRead = len; cp = (char *) &buf; while(amtToRead > 0 && (numRead = read(sockFD, cp, amtToRead)) > 0){ cp += numRead; amtToRead -= numRead; } if (numRead <= 0) { error = ERR_READING_MSG; break; } i = buf.qb1.rcode; if (i != NOERROR || ntohs(buf.qb1.ancount) == 0) { if ((thisns+1) < numnsaddr && (i == SERVFAIL || i == NOTIMP || i == REFUSED)) { if (_res.options & RES_DEBUG || verbose) printf("Server failed, trying next server: %s\n", i != NOERROR ? DecodeError(i) : "Premature end of data"); (void) close(sockFD); sockFD = -1; thisns++; goto again; } printf("Server failed: %s\n", i != NOERROR ? DecodeError(i) : "Premature end of data"); break; } result = printinfo(&buf, cp, queryType, 1); if (! result) { error = ERR_PRINTING; break; } numAnswers++; cp = buf.qb2 + sizeof(HEADER); if (ntohs(buf.qb1.qdcount) > 0) cp += dn_skipname(cp, buf.qb2 + len) + QFIXEDSZ; nmp = cp; cp += dn_skipname(cp, (u_char *)&buf + len); if ((_getshort(cp) == T_SOA)) { dn_expand(buf.qb2, buf.qb2 + len, nmp, dname[soacnt], sizeof(dname[0])); if (soacnt) { if (strcmp(dname[0], dname[1]) == 0) break; } else soacnt++; } } (void) close(sockFD); sockFD = -1; switch (error) { case NO_ERRORS: return (SUCCESS); case ERR_READING_LEN: return(ERROR); case ERR_PRINTING: fprintf(stderr,"*** Error during listing of %s: %s\n", namePtr, DecodeError(result)); return(result); case ERR_READING_MSG: headerPtr = (HEADER *) &buf; fprintf(stderr,"ListHosts: error receiving zone transfer:\n"); fprintf(stderr, " result: %s, answers = %d, authority = %d, additional = %d\n", resultcodes[headerPtr->rcode], ntohs(headerPtr->ancount), ntohs(headerPtr->nscount), ntohs(headerPtr->arcount)); return(ERROR); default: return(ERROR); } } char * DecodeError(result) int result; { switch(result) { case NOERROR: return("Success"); break; case FORMERR: return("Format error"); break; case SERVFAIL: return("Server failed"); break; case NXDOMAIN: return("Non-existent domain"); break; case NOTIMP: return("Not implemented"); break; case REFUSED: return("Query refused"); break; #ifndef SGI case NOCHANGE: return("No change"); break; #endif case NO_INFO: return("No information"); break; case ERROR: return("Unspecified error"); break; case TIME_OUT: return("Timed out"); break; case NONAUTH: return("Non-authoritative answer"); break; default: break; } return("BAD ERROR VALUE"); } cname_search(name) char *name; { FILE *fp; char buf[BUFSIZ]; char *bufP; char *nameP; if((fp = fopen(NDB, "r")) == (FILE *) NULL) { if(verbose) fprintf(stderr, "unable to open file \"%s\"\n", NDB); return; } bufP = name; while(*bufP) { if(islower(*bufP)) *bufP = toupper(*bufP); ++bufP; } while(fgets(buf, sizeof(buf)-1, fp) != (char *) NULL) { bufP = buf; nameP = name; if(*bufP != *nameP) continue; while(*nameP && *bufP && (*++bufP == *++nameP)); if(*nameP != '\0') continue; if((*bufP != ' ') && (*bufP != '\t')) continue; while(fgets(buf, sizeof(buf)-1, fp) != (char *) NULL) { bufP = buf; while(*bufP && (*bufP != ' ') && (*bufP != '\t')) bufP++; *bufP++ = '\0'; while(*bufP && ((*bufP == ' ') || (*bufP == '\t'))) bufP++; while(*bufP && (*bufP != ' ') && (*bufP != '\t')) bufP++; while(*bufP && ((*bufP == ' ') || (*bufP == '\t'))) bufP++; if(strncmp(bufP, "CNAME", 4) != 0) continue; while(*bufP && (*bufP != ' ') && (*bufP != '\t')) bufP++; while(*bufP && ((*bufP == ' ') || (*bufP == '\t'))) bufP++; if(strncmp(bufP, name, strlen(name)) != 0) return; printf("Host alias: %s.%s\n", buf, NDB_DOMAIN); } } return; }