/* Copyright 1998 by the Massachusetts Institute of Technology. * * * Permission to use, copy, modify, and distribute this * software and its documentation for any purpose and without * fee is hereby granted, provided that the above copyright * notice appear in all copies and that both that copyright * notice and this permission notice appear in supporting * documentation, and that the name of M.I.T. not be used in * advertising or publicity pertaining to distribution of the * software without specific, written prior permission. * M.I.T. makes no representations about the suitability of * this software for any purpose. It is provided "as is" * without express or implied warranty. */ #include "ares_setup.h" #ifdef HAVE_NETINET_IN_H # include #endif #ifdef HAVE_ARPA_INET_H # include #endif #ifdef HAVE_NETDB_H # include #endif #ifdef HAVE_ARPA_NAMESER_H # include #else # include "nameser.h" #endif #ifdef HAVE_ARPA_NAMESER_COMPAT_H # include #endif #ifdef HAVE_STRINGS_H # include #endif #include "ares.h" #include "ares_dns.h" #include "inet_ntop.h" #include "inet_net_pton.h" #include "ares_getopt.h" #include "ares_nowarn.h" #ifndef HAVE_STRDUP # include "ares_strdup.h" # define strdup(ptr) ares_strdup(ptr) #endif #ifndef HAVE_STRCASECMP # include "ares_strcasecmp.h" # define strcasecmp(p1,p2) ares_strcasecmp(p1,p2) #endif #ifndef HAVE_STRNCASECMP # include "ares_strcasecmp.h" # define strncasecmp(p1,p2,n) ares_strncasecmp(p1,p2,n) #endif #ifdef WATT32 #undef WIN32 /* Redefined in MingW headers */ #endif #ifndef T_SRV # define T_SRV 33 /* Server selection */ #endif #ifndef T_NAPTR # define T_NAPTR 35 /* Naming authority pointer */ #endif #ifndef T_DS # define T_DS 43 /* Delegation Signer (RFC4034) */ #endif #ifndef T_SSHFP # define T_SSHFP 44 /* SSH Key Fingerprint (RFC4255) */ #endif #ifndef T_RRSIG # define T_RRSIG 46 /* Resource Record Signature (RFC4034) */ #endif #ifndef T_NSEC # define T_NSEC 47 /* Next Secure (RFC4034) */ #endif #ifndef T_DNSKEY # define T_DNSKEY 48 /* DNS Public Key (RFC4034) */ #endif struct nv { const char *name; int value; }; static const struct nv flags[] = { { "usevc", ARES_FLAG_USEVC }, { "primary", ARES_FLAG_PRIMARY }, { "igntc", ARES_FLAG_IGNTC }, { "norecurse", ARES_FLAG_NORECURSE }, { "stayopen", ARES_FLAG_STAYOPEN }, { "noaliases", ARES_FLAG_NOALIASES } }; static const int nflags = sizeof(flags) / sizeof(flags[0]); static const struct nv classes[] = { { "IN", C_IN }, { "CHAOS", C_CHAOS }, { "HS", C_HS }, { "ANY", C_ANY } }; static const int nclasses = sizeof(classes) / sizeof(classes[0]); static const struct nv types[] = { { "A", T_A }, { "NS", T_NS }, { "MD", T_MD }, { "MF", T_MF }, { "CNAME", T_CNAME }, { "SOA", T_SOA }, { "MB", T_MB }, { "MG", T_MG }, { "MR", T_MR }, { "NULL", T_NULL }, { "WKS", T_WKS }, { "PTR", T_PTR }, { "HINFO", T_HINFO }, { "MINFO", T_MINFO }, { "MX", T_MX }, { "TXT", T_TXT }, { "RP", T_RP }, { "AFSDB", T_AFSDB }, { "X25", T_X25 }, { "ISDN", T_ISDN }, { "RT", T_RT }, { "NSAP", T_NSAP }, { "NSAP_PTR", T_NSAP_PTR }, { "SIG", T_SIG }, { "KEY", T_KEY }, { "PX", T_PX }, { "GPOS", T_GPOS }, { "AAAA", T_AAAA }, { "LOC", T_LOC }, { "SRV", T_SRV }, { "AXFR", T_AXFR }, { "MAILB", T_MAILB }, { "MAILA", T_MAILA }, { "NAPTR", T_NAPTR }, { "DS", T_DS }, { "SSHFP", T_SSHFP }, { "RRSIG", T_RRSIG }, { "NSEC", T_NSEC }, { "DNSKEY", T_DNSKEY }, { "ANY", T_ANY } }; static const int ntypes = sizeof(types) / sizeof(types[0]); static const char *opcodes[] = { "QUERY", "IQUERY", "STATUS", "(reserved)", "NOTIFY", "(unknown)", "(unknown)", "(unknown)", "(unknown)", "UPDATEA", "UPDATED", "UPDATEDA", "UPDATEM", "UPDATEMA", "ZONEINIT", "ZONEREF" }; static const char *rcodes[] = { "NOERROR", "FORMERR", "SERVFAIL", "NXDOMAIN", "NOTIMP", "REFUSED", "(unknown)", "(unknown)", "(unknown)", "(unknown)", "(unknown)", "(unknown)", "(unknown)", "(unknown)", "(unknown)", "NOCHANGE" }; static void callback(void *arg, int status, int timeouts, unsigned char *abuf, int alen); static const unsigned char *display_question(const unsigned char *aptr, const unsigned char *abuf, int alen); static const unsigned char *display_rr(const unsigned char *aptr, const unsigned char *abuf, int alen); static const char *type_name(int type); static const char *class_name(int dnsclass); static void usage(void); static void destroy_addr_list(struct ares_addr_node *head); static void append_addr_list(struct ares_addr_node **head, struct ares_addr_node *node); int main(int argc, char **argv) { ares_channel channel; int c, i, optmask = ARES_OPT_FLAGS, dnsclass = C_IN, type = T_A; int status, nfds, count; struct ares_options options; struct hostent *hostent; fd_set read_fds, write_fds; struct timeval *tvp, tv; struct ares_addr_node *srvr, *servers = NULL; #ifdef USE_WINSOCK WORD wVersionRequested = MAKEWORD(USE_WINSOCK,USE_WINSOCK); WSADATA wsaData; WSAStartup(wVersionRequested, &wsaData); #endif status = ares_library_init(ARES_LIB_INIT_ALL); if (status != ARES_SUCCESS) { fprintf(stderr, "ares_library_init: %s\n", ares_strerror(status)); return 1; } options.flags = ARES_FLAG_NOCHECKRESP; options.servers = NULL; options.nservers = 0; while ((c = ares_getopt(argc, argv, "df:s:c:t:T:U:")) != -1) { switch (c) { case 'd': #ifdef WATT32 dbug_init(); #endif break; case 'f': /* Add a flag. */ for (i = 0; i < nflags; i++) { if (strcmp(flags[i].name, optarg) == 0) break; } if (i < nflags) options.flags |= flags[i].value; else usage(); break; case 's': /* User-specified name servers override default ones. */ srvr = malloc(sizeof(struct ares_addr_node)); if (!srvr) { fprintf(stderr, "Out of memory!\n"); destroy_addr_list(servers); return 1; } append_addr_list(&servers, srvr); if (ares_inet_pton(AF_INET, optarg, &srvr->addr.addr4) > 0) srvr->family = AF_INET; else if (ares_inet_pton(AF_INET6, optarg, &srvr->addr.addr6) > 0) srvr->family = AF_INET6; else { hostent = gethostbyname(optarg); if (!hostent) { fprintf(stderr, "adig: server %s not found.\n", optarg); destroy_addr_list(servers); return 1; } switch (hostent->h_addrtype) { case AF_INET: srvr->family = AF_INET; memcpy(&srvr->addr.addr4, hostent->h_addr, sizeof(srvr->addr.addr4)); break; case AF_INET6: srvr->family = AF_INET6; memcpy(&srvr->addr.addr6, hostent->h_addr, sizeof(srvr->addr.addr6)); break; default: fprintf(stderr, "adig: server %s unsupported address family.\n", optarg); destroy_addr_list(servers); return 1; } } /* Notice that calling ares_init_options() without servers in the * options struct and with ARES_OPT_SERVERS set simultaneously in * the options mask, results in an initialization with no servers. * When alternative name servers have been specified these are set * later calling ares_set_servers() overriding any existing server * configuration. To prevent initial configuration with default * servers that will be discarded later, ARES_OPT_SERVERS is set. * If this flag is not set here the result shall be the same but * ares_init_options() will do needless work. */ optmask |= ARES_OPT_SERVERS; break; case 'c': /* Set the query class. */ for (i = 0; i < nclasses; i++) { if (strcasecmp(classes[i].name, optarg) == 0) break; } if (i < nclasses) dnsclass = classes[i].value; else usage(); break; case 't': /* Set the query type. */ for (i = 0; i < ntypes; i++) { if (strcasecmp(types[i].name, optarg) == 0) break; } if (i < ntypes) type = types[i].value; else usage(); break; case 'T': /* Set the TCP port number. */ if (!ISDIGIT(*optarg)) usage(); options.tcp_port = (unsigned short)strtol(optarg, NULL, 0); optmask |= ARES_OPT_TCP_PORT; break; case 'U': /* Set the UDP port number. */ if (!ISDIGIT(*optarg)) usage(); options.udp_port = (unsigned short)strtol(optarg, NULL, 0); optmask |= ARES_OPT_UDP_PORT; break; } } argc -= optind; argv += optind; if (argc == 0) usage(); status = ares_init_options(&channel, &options, optmask); if (status != ARES_SUCCESS) { fprintf(stderr, "ares_init_options: %s\n", ares_strerror(status)); return 1; } if(servers) { status = ares_set_servers(channel, servers); destroy_addr_list(servers); if (status != ARES_SUCCESS) { fprintf(stderr, "ares_init_options: %s\n", ares_strerror(status)); return 1; } } /* Initiate the queries, one per command-line argument. If there is * only one query to do, supply NULL as the callback argument; * otherwise, supply the query name as an argument so we can * distinguish responses for the user when printing them out. */ if (argc == 1) ares_query(channel, *argv, dnsclass, type, callback, (char *) NULL); else { for (; *argv; argv++) ares_query(channel, *argv, dnsclass, type, callback, *argv); } /* Wait for all queries to complete. */ for (;;) { FD_ZERO(&read_fds); FD_ZERO(&write_fds); nfds = ares_fds(channel, &read_fds, &write_fds); if (nfds == 0) break; tvp = ares_timeout(channel, NULL, &tv); count = select(nfds, &read_fds, &write_fds, NULL, tvp); if (count < 0 && (status = SOCKERRNO) != EINVAL) { printf("select fail: %d", status); return 1; } ares_process(channel, &read_fds, &write_fds); } ares_destroy(channel); ares_library_cleanup(); #ifdef USE_WINSOCK WSACleanup(); #endif return 0; } static void callback(void *arg, int status, int timeouts, unsigned char *abuf, int alen) { char *name = (char *) arg; int id, qr, opcode, aa, tc, rd, ra, rcode; unsigned int qdcount, ancount, nscount, arcount, i; const unsigned char *aptr; (void) timeouts; /* Display the query name if given. */ if (name) printf("Answer for query %s:\n", name); /* Display an error message if there was an error, but only stop if * we actually didn't get an answer buffer. */ if (status != ARES_SUCCESS) { printf("%s\n", ares_strerror(status)); if (!abuf) return; } /* Won't happen, but check anyway, for safety. */ if (alen < HFIXEDSZ) return; /* Parse the answer header. */ id = DNS_HEADER_QID(abuf); qr = DNS_HEADER_QR(abuf); opcode = DNS_HEADER_OPCODE(abuf); aa = DNS_HEADER_AA(abuf); tc = DNS_HEADER_TC(abuf); rd = DNS_HEADER_RD(abuf); ra = DNS_HEADER_RA(abuf); rcode = DNS_HEADER_RCODE(abuf); qdcount = DNS_HEADER_QDCOUNT(abuf); ancount = DNS_HEADER_ANCOUNT(abuf); nscount = DNS_HEADER_NSCOUNT(abuf); arcount = DNS_HEADER_ARCOUNT(abuf); /* Display the answer header. */ printf("id: %d\n", id); printf("flags: %s%s%s%s%s\n", qr ? "qr " : "", aa ? "aa " : "", tc ? "tc " : "", rd ? "rd " : "", ra ? "ra " : ""); printf("opcode: %s\n", opcodes[opcode]); printf("rcode: %s\n", rcodes[rcode]); /* Display the questions. */ printf("Questions:\n"); aptr = abuf + HFIXEDSZ; for (i = 0; i < qdcount; i++) { aptr = display_question(aptr, abuf, alen); if (aptr == NULL) return; } /* Display the answers. */ printf("Answers:\n"); for (i = 0; i < ancount; i++) { aptr = display_rr(aptr, abuf, alen); if (aptr == NULL) return; } /* Display the NS records. */ printf("NS records:\n"); for (i = 0; i < nscount; i++) { aptr = display_rr(aptr, abuf, alen); if (aptr == NULL) return; } /* Display the additional records. */ printf("Additional records:\n"); for (i = 0; i < arcount; i++) { aptr = display_rr(aptr, abuf, alen); if (aptr == NULL) return; } } static const unsigned char *display_question(const unsigned char *aptr, const unsigned char *abuf, int alen) { char *name; int type, dnsclass, status; long len; /* Parse the question name. */ status = ares_expand_name(aptr, abuf, alen, &name, &len); if (status != ARES_SUCCESS) return NULL; aptr += len; /* Make sure there's enough data after the name for the fixed part * of the question. */ if (aptr + QFIXEDSZ > abuf + alen) { ares_free_string(name); return NULL; } /* Parse the question type and class. */ type = DNS_QUESTION_TYPE(aptr); dnsclass = DNS_QUESTION_CLASS(aptr); aptr += QFIXEDSZ; /* Display the question, in a format sort of similar to how we will * display RRs. */ printf("\t%-15s.\t", name); if (dnsclass != C_IN) printf("\t%s", class_name(dnsclass)); printf("\t%s\n", type_name(type)); ares_free_string(name); return aptr; } static const unsigned char *display_rr(const unsigned char *aptr, const unsigned char *abuf, int alen) { const unsigned char *p; int type, dnsclass, ttl, dlen, status; long len; char addr[46]; union { unsigned char * as_uchar; char * as_char; } name; /* Parse the RR name. */ status = ares_expand_name(aptr, abuf, alen, &name.as_char, &len); if (status != ARES_SUCCESS) return NULL; aptr += len; /* Make sure there is enough data after the RR name for the fixed * part of the RR. */ if (aptr + RRFIXEDSZ > abuf + alen) { ares_free_string(name.as_char); return NULL; } /* Parse the fixed part of the RR, and advance to the RR data * field. */ type = DNS_RR_TYPE(aptr); dnsclass = DNS_RR_CLASS(aptr); ttl = DNS_RR_TTL(aptr); dlen = DNS_RR_LEN(aptr); aptr += RRFIXEDSZ; if (aptr + dlen > abuf + alen) { ares_free_string(name.as_char); return NULL; } /* Display the RR name, class, and type. */ printf("\t%-15s.\t%d", name.as_char, ttl); if (dnsclass != C_IN) printf("\t%s", class_name(dnsclass)); printf("\t%s", type_name(type)); ares_free_string(name.as_char); /* Display the RR data. Don't touch aptr. */ switch (type) { case T_CNAME: case T_MB: case T_MD: case T_MF: case T_MG: case T_MR: case T_NS: case T_PTR: /* For these types, the RR data is just a domain name. */ status = ares_expand_name(aptr, abuf, alen, &name.as_char, &len); if (status != ARES_SUCCESS) return NULL; printf("\t%s.", name.as_char); ares_free_string(name.as_char); break; case T_HINFO: /* The RR data is two length-counted character strings. */ p = aptr; len = *p; if (p + len + 1 > aptr + dlen) return NULL; status = ares_expand_string(p, abuf, alen, &name.as_uchar, &len); if (status != ARES_SUCCESS) return NULL; printf("\t%s", name.as_char); ares_free_string(name.as_char); p += len; len = *p; if (p + len + 1 > aptr + dlen) return NULL; status = ares_expand_string(p, abuf, alen, &name.as_uchar, &len); if (status != ARES_SUCCESS) return NULL; printf("\t%s", name.as_char); ares_free_string(name.as_char); break; case T_MINFO: /* The RR data is two domain names. */ p = aptr; status = ares_expand_name(p, abuf, alen, &name.as_char, &len); if (status != ARES_SUCCESS) return NULL; printf("\t%s.", name.as_char); ares_free_string(name.as_char); p += len; status = ares_expand_name(p, abuf, alen, &name.as_char, &len); if (status != ARES_SUCCESS) return NULL; printf("\t%s.", name.as_char); ares_free_string(name.as_char); break; case T_MX: /* The RR data is two bytes giving a preference ordering, and * then a domain name. */ if (dlen < 2) return NULL; printf("\t%d", (int)DNS__16BIT(aptr)); status = ares_expand_name(aptr + 2, abuf, alen, &name.as_char, &len); if (status != ARES_SUCCESS) return NULL; printf("\t%s.", name.as_char); ares_free_string(name.as_char); break; case T_SOA: /* The RR data is two domain names and then five four-byte * numbers giving the serial number and some timeouts. */ p = aptr; status = ares_expand_name(p, abuf, alen, &name.as_char, &len); if (status != ARES_SUCCESS) return NULL; printf("\t%s.\n", name.as_char); ares_free_string(name.as_char); p += len; status = ares_expand_name(p, abuf, alen, &name.as_char, &len); if (status != ARES_SUCCESS) return NULL; printf("\t\t\t\t\t\t%s.\n", name.as_char); ares_free_string(name.as_char); p += len; if (p + 20 > aptr + dlen) return NULL; printf("\t\t\t\t\t\t( %u %u %u %u %u )", DNS__32BIT(p), DNS__32BIT(p+4), DNS__32BIT(p+8), DNS__32BIT(p+12), DNS__32BIT(p+16)); break; case T_TXT: /* The RR data is one or more length-counted character * strings. */ p = aptr; while (p < aptr + dlen) { len = *p; if (p + len + 1 > aptr + dlen) return NULL; status = ares_expand_string(p, abuf, alen, &name.as_uchar, &len); if (status != ARES_SUCCESS) return NULL; printf("\t%s", name.as_char); ares_free_string(name.as_char); p += len; } break; case T_A: /* The RR data is a four-byte Internet address. */ if (dlen != 4) return NULL; printf("\t%s", ares_inet_ntop(AF_INET,aptr,addr,sizeof(addr))); break; case T_AAAA: /* The RR data is a 16-byte IPv6 address. */ if (dlen != 16) return NULL; printf("\t%s", ares_inet_ntop(AF_INET6,aptr,addr,sizeof(addr))); break; case T_WKS: /* Not implemented yet */ break; case T_SRV: /* The RR data is three two-byte numbers representing the * priority, weight, and port, followed by a domain name. */ printf("\t%d", (int)DNS__16BIT(aptr)); printf(" %d", (int)DNS__16BIT(aptr + 2)); printf(" %d", (int)DNS__16BIT(aptr + 4)); status = ares_expand_name(aptr + 6, abuf, alen, &name.as_char, &len); if (status != ARES_SUCCESS) return NULL; printf("\t%s.", name.as_char); ares_free_string(name.as_char); break; case T_NAPTR: printf("\t%d", (int)DNS__16BIT(aptr)); /* order */ printf(" %d\n", (int)DNS__16BIT(aptr + 2)); /* preference */ p = aptr + 4; status = ares_expand_string(p, abuf, alen, &name.as_uchar, &len); if (status != ARES_SUCCESS) return NULL; printf("\t\t\t\t\t\t%s\n", name.as_char); ares_free_string(name.as_char); p += len; status = ares_expand_string(p, abuf, alen, &name.as_uchar, &len); if (status != ARES_SUCCESS) return NULL; printf("\t\t\t\t\t\t%s\n", name.as_char); ares_free_string(name.as_char); p += len; status = ares_expand_string(p, abuf, alen, &name.as_uchar, &len); if (status != ARES_SUCCESS) return NULL; printf("\t\t\t\t\t\t%s\n", name.as_char); ares_free_string(name.as_char); p += len; status = ares_expand_name(p, abuf, alen, &name.as_char, &len); if (status != ARES_SUCCESS) return NULL; printf("\t\t\t\t\t\t%s", name.as_char); ares_free_string(name.as_char); break; case T_DS: case T_SSHFP: case T_RRSIG: case T_NSEC: case T_DNSKEY: printf("\t[RR type parsing unavailable]"); break; default: printf("\t[Unknown RR; cannot parse]"); break; } printf("\n"); return aptr + dlen; } static const char *type_name(int type) { int i; for (i = 0; i < ntypes; i++) { if (types[i].value == type) return types[i].name; } return "(unknown)"; } static const char *class_name(int dnsclass) { int i; for (i = 0; i < nclasses; i++) { if (classes[i].value == dnsclass) return classes[i].name; } return "(unknown)"; } static void usage(void) { fprintf(stderr, "usage: adig [-f flag] [-s server] [-c class] " "[-t type] [-p port] name ...\n"); exit(1); } static void destroy_addr_list(struct ares_addr_node *head) { while(head) { struct ares_addr_node *detached = head; head = head->next; free(detached); } } static void append_addr_list(struct ares_addr_node **head, struct ares_addr_node *node) { struct ares_addr_node *last; node->next = NULL; if(*head) { last = *head; while(last->next) last = last->next; last->next = node; } else *head = node; }