#if !defined(lint) && !defined(SABER) static char sccsid[] = "@(#)ns_resp.c 4.65 (Berkeley) 3/3/91"; static char rcsid[] = "$Id: ns_resp.c,v 8.56 1998/03/16 19:40:07 halley Exp $"; #endif /* not lint */ /* * Copyright (c) 1986, 1988, 1990 * 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. */ /* * Portions Copyright (c) 1995 by International Business Machines, Inc. * * International Business Machines, Inc. (hereinafter called IBM) grants * permission under its copyrights to use, copy, modify, and distribute this * Software with or without fee, provided that the above copyright notice and * all paragraphs of this notice appear in all copies, and that the name of IBM * not be used in connection with the marketing of any product incorporating * the Software or modifications thereof, without specific, written prior * permission. * * To the extent it has a right to do so, IBM grants an immunity from suit * under its patents, if any, for the use, sale or manufacture of products to * the extent that such products are used for performing Domain Name System * dynamic updates in TCP/IP networks by means of the Software. No immunity is * granted for any product per se or for any other function of any product. * * THE SOFTWARE IS PROVIDED "AS IS", AND IBM DISCLAIMS ALL WARRANTIES, * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A * PARTICULAR PURPOSE. IN NO EVENT SHALL IBM BE LIABLE FOR ANY SPECIAL, * DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER ARISING * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE, EVEN * IF IBM IS APPRISED OF THE POSSIBILITY OF SUCH DAMAGES. */ /* * Portions Copyright (c) 1996, 1997 by Internet Software Consortium. * * 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. * * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE * CONSORTIUM 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. */ #include "port_before.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "port_after.h" #include "named.h" static u_int8_t norootlogged[MAXCLASS]; /* XXX- should be a bitmap */ static const char skipnameFailedAnswer[] = "skipname failed in answer", skipnameFailedAuth[] = "skipname failed in authority", skipnameFailedQuery[] = "skipname failed in query", outofDataQuery[] = "ran out of data in query", outofDataAnswer[] = "ran out of data in answer", notSingleQuery[] = "not exactly one query", expandFailedQuery[] = "dn_expand failed in query", expandFailedAnswer[] = "dn_expand failed in answer", expandFailedAuth[] = "dn_expand failed in authority", outofDataAuth[] = "ran out of data in authority", dlenOverrunAnswer[] = "dlen overrun in answer", dlenOverrunAuth[] = "dlen overrun in authority", dlenUnderrunAnswer[] = "dlen underrun in answer", outofDataFinal[] = "out of data in final pass", outofDataAFinal[] = "out of data after final pass", badNameFound[] = "found an invalid domain name", wrongQuestion[] = "answer to wrong question", danglingCname[] = "dangling CNAME pointer"; struct db_list { struct db_list *db_next; struct databuf *db_dp; }; struct flush_set { char * fs_name; int fs_type; int fs_class; u_int fs_cred; struct db_list *fs_list; struct db_list *fs_last; }; static void rrsetadd(struct flush_set *, const char *, struct databuf *), rrsetupdate(struct flush_set *, int flags, struct sockaddr_in), flushrrset(struct flush_set *, struct sockaddr_in), free_flushset(struct flush_set *, int); static int rrsetcmp(char *, struct db_list *), check_root(void), check_ns(void), rrextract(u_char *, int, u_char *, struct databuf **, char *, int, struct sockaddr_in, char **); static void sysnotify_slaves(const char *, const char *, int, int, int *, int *); static void sysnotify_ns(const char *, const char *, int, int, int *, int *); static void add_related_additional(char *); static void free_related_additional(void); static int related_additional(char *); static void freestr_maybe(char **); #define MAX_RELATED 100 static int num_related = 0; static char *related[MAX_RELATED]; static char * learntFrom(struct qinfo *qp, struct sockaddr_in *server) { static char *buf = NULL; char *a, *ns, *na; struct databuf *db; int i; a = ns = na = ""; for (i = 0; (u_int)i < qp->q_naddr; i++) { if (ina_equal(qp->q_addr[i].ns_addr.sin_addr, server->sin_addr)) { db = qp->q_addr[i].ns; if (db != NULL) { if (NS_OPTION_P(OPTION_HOSTSTATS)) { char nsbuf[20]; if (db->d_ns != NULL) { strcpy(nsbuf, inet_ntoa(db->d_ns->addr)); ns = nsbuf; } else { ns = zones[db->d_zone] .z_origin; } } if (db->d_rcode == 0) na = (char*)qp->q_addr[i].ns->d_data; } if (NS_OPTION_P(OPTION_HOSTSTATS)) { char abuf[20]; db = qp->q_addr[i].nsdata; if (db != NULL) { if (db->d_ns != NULL) { strcpy(abuf, inet_ntoa(db->d_ns->addr)); a = abuf; } else { a = zones[db->d_zone].z_origin; } } } break; } } if (a == ns && ns == na) /* all "UNKNOWN" */ return (NULL); if (*a == '\0') a = "\".\""; if (*ns == '\0') ns = "\".\""; if (*na == '\0') na = "\".\""; if (NS_OPTION_P(OPTION_HOSTSTATS)) { static const char fmt[] = " '%s': learnt (A=%s,NS=%s)"; buf = newstr(sizeof fmt + strlen(na) + strlen(a) + strlen(ns), 0); if (buf == NULL) return (NULL); sprintf(buf, fmt, na, a, ns); } else { static const char fmt[] = " '%s'"; buf = newstr(sizeof fmt + strlen(na), 0); if (buf == NULL) return (NULL); sprintf(buf, fmt, na); } return (buf); } void ns_resp(u_char *msg, int msglen, struct sockaddr_in from, struct qstream *qsp) { struct qinfo *qp; HEADER *hp; struct qserv *qs; struct databuf *ns, *ns2; u_char *cp; u_char *eom = msg + msglen; struct flush_set *flushset = NULL; int flushset_size = 0; struct sockaddr_in *nsa; struct databuf *nsp[NSMAX]; int i, c, n, qdcount, ancount, aucount, nscount, arcount, arfirst; u_int qtype, qclass; int restart; /* flag for processing cname response */ int validanswer, dbflags; int cname, lastwascname, externalcname; int count, founddata, foundname; int buflen; int newmsglen; char name[MAXDNAME], qname[MAXDNAME], aname[MAXDNAME]; char msgbuf[MAXDNAME]; char *dname, tmpdomain[MAXDNAME]; const char *fname; const char *formerrmsg = "brain damage"; u_char newmsg[PACKETSZ]; u_char **dpp, *tp; time_t rtrip; struct hashbuf *htp; struct namebuf *np; struct fwdinfo *fwd; struct databuf *dp; int forcecmsg = 0; char *tname = NULL; nameserIncr(from.sin_addr, nssRcvdR); nsp[0] = NULL; hp = (HEADER *) msg; if ((qp = qfindid(hp->id)) == NULL ) { ns_debug(ns_log_default, 1, "DUP? dropped (id %d)", ntohs(hp->id)); nameserIncr(from.sin_addr, nssRcvdDupR); return; } ns_debug(ns_log_default, 2, "Response (%s %s %s) nsid=%d id=%d", (qp->q_flags & Q_SYSTEM) ?"SYSTEM" :"USER", (qp->q_flags & Q_PRIMING) ?"PRIMING" :"NORMAL", (qp->q_flags & Q_ZSERIAL) ?"ZSERIAL" :"-", ntohs(qp->q_nsid), ntohs(qp->q_id)); /* * Here we handle high level formatting problems by parsing the header. */ qdcount = ntohs(hp->qdcount); ancount = ntohs(hp->ancount); aucount = ntohs(hp->nscount); /* !!! */ arcount = ntohs(hp->arcount); free_addinfo(); /* sets addcount to zero */ cp = msg + HFIXEDSZ; dpp = dnptrs; *dpp++ = msg; if ((*cp & INDIR_MASK) == 0) *dpp++ = cp; *dpp = NULL; if (qdcount == 1) { n = dn_expand(msg, eom, cp, qname, sizeof(qname)); if (n <= 0) { formerrmsg = expandFailedQuery; goto formerr; } cp += n; if (cp + 2 * INT16SZ > eom) { formerrmsg = outofDataQuery; goto formerr; } GETSHORT(qtype, cp); GETSHORT(qclass, cp); if (!ns_nameok(qname, qclass, NULL, response_trans, ns_ownercontext(qtype, response_trans), qname, from.sin_addr)) { formerrmsg = badNameFound; goto refused; } if (cp > eom) { formerrmsg = outofDataQuery; goto formerr; } if (qp->q_msg && qp->q_msglen && !res_nameinquery(qname, qtype, qclass, qp->q_msg, qp->q_msg + qp->q_msglen)) { sprintf(msgbuf, "query section mismatch (%s %s %s)", qname, p_class(qclass), p_type(qtype)); formerrmsg = msgbuf; goto formerr; } if (strcasecmp(qp->q_name, qname) != 0 || qp->q_class != qclass || qp->q_type != qtype) { formerrmsg = wrongQuestion; goto formerr; } } else { strcpy(qname, qp->q_name); qclass = qp->q_class; qtype = qp->q_type; } /* cp now points after the query section. */ /* * Here we handle bad responses from servers. * Several possibilities come to mind: * The server is sick and returns SERVFAIL * The server returns some garbage opcode (it's sick) * The server can't understand our query and return FORMERR * In all these cases, we drop the packet, disable retries on * this server and immediately force a retry. */ if ((hp->rcode != NOERROR && hp->rcode != NXDOMAIN) || (hp->opcode != QUERY #ifdef BIND_NOTIFY && hp->opcode != NS_NOTIFY_OP #endif )) { ns_debug(ns_log_default, 2, "resp: error (ret %d, op %d), dropped", hp->rcode, hp->opcode); switch (hp->rcode) { case SERVFAIL: nameserIncr(from.sin_addr, nssRcvdFail); break; case FORMERR: nameserIncr(from.sin_addr, nssRcvdFErr); break; default: nameserIncr(from.sin_addr, nssRcvdErr); break; } /* mark server as bad */ if (!qp->q_fwd) for (i = 0; i < (int)qp->q_naddr; i++) if (ina_equal(qp->q_addr[i].ns_addr.sin_addr, from.sin_addr)) qp->q_addr[i].nretry = MAXRETRY; /* * XXX: doesn't handle responses sent from the wrong * interface on a multihomed server. */ if (qp->q_fwd || ina_equal(qp->q_addr[qp->q_curaddr].ns_addr.sin_addr, from.sin_addr)) retry(qp); return; } if (qdcount != 1) { /* We don't generate or forward these (yet). */ formerrmsg = notSingleQuery; goto formerr; } /* * Determine if the response came from a forwarder. Packets from * anyplace not listed as a forwarder or as a server to whom we * might have forwarded the query will be dropped. * XXX - should put this in STATS somewhere. */ for (fwd = server_options->fwdtab; fwd; fwd = fwd->next) if (ina_equal(fwd->fwdaddr.sin_addr, from.sin_addr)) break; /* * XXX: note bad ambiguity here. if one of our forwarders is also * a delegated server for some domain, then we will not update * the RTT information on any replies we get from those servers. * Workaround: disable recursion on authoritative servers so that * the ambiguity does not arise. */ /* * If we weren't using a forwarder, find the qinfo pointer and update * the rtt and fact that we have called on this server before. */ if (fwd == NULL) { struct timeval *stp; for (n = 0, qs = qp->q_addr; (u_int)n < qp->q_naddr; n++, qs++) if (ina_equal(qs->ns_addr.sin_addr, from.sin_addr)) break; if ((u_int)n >= qp->q_naddr) { if (!haveComplained(ina_ulong(from.sin_addr), (u_long)"unexpected source")) { ns_info(ns_log_default, "Response from unexpected source (%s)", sin_ntoa(from)); } /* * We don't know who this response came from so it * gets dropped on the floor. */ return; } stp = &qs->stime; /* Handle response from different (untried) interface. */ if ((qs->ns != NULL) && (stp->tv_sec == 0)) { ns = qs->ns; while (qs > qp->q_addr && (qs->stime.tv_sec == 0 || qs->ns != ns)) qs--; *stp = qs->stime; /* XXX - sometimes stp still ends up pointing to * a zero timeval, in spite of the above attempt. * Why? What should we do about it? */ /* XXX - catch aliases here */ } /* compute query round trip time */ /* XXX - avoid integer overflow, which is quite likely if stp * points to a zero timeval (see above). * rtrip is of type time_t, which we assume is at least * as big as an int. */ if ((tt.tv_sec - stp->tv_sec) > (INT_MAX-999)/1000) { rtrip = INT_MAX; } else { rtrip = ((tt.tv_sec - stp->tv_sec) * 1000 + (tt.tv_usec - stp->tv_usec) / 1000); } ns_debug(ns_log_default, 3, "stime %lu/%lu now %lu/%lu rtt %ld", (u_long)stp->tv_sec, (u_long)stp->tv_usec, (u_long)tt.tv_sec, (u_long)tt.tv_usec, (long)rtrip); /* prevent floating point overflow, limit to 1000 sec */ if (rtrip > 1000000) { rtrip = 1000000; } ns = qs->nsdata; /* * Don't update nstime if this doesn't look * like an address databuf now. XXX */ if (ns && ns->d_type == T_A && ns->d_class == qs->ns->d_class) { u_long t; if (ns->d_nstime == 0) t = rtrip; else t = ns->d_nstime * ALPHA + (1 - ALPHA) * rtrip; if (t > 65535) t = 65535; ns->d_nstime = (u_int16_t)t; } /* * Record the source so that we do not use this NS again. */ if (ns && qs->ns && (qp->q_nusedns < NSMAX)) { qp->q_usedns[qp->q_nusedns++] = qs->ns; ns_debug(ns_log_default, 2, "NS #%d addr %s used, rtt %d", n, sin_ntoa(qs->ns_addr), ns->d_nstime); } /* * Penalize those who had earlier chances but failed * by multiplying round-trip times by BETA (>1). * Improve nstime for unused addresses by applying GAMMA. * The GAMMA factor makes unused entries slowly * improve, so they eventually get tried again. * GAMMA should be slightly less than 1. * Watch out for records that may have timed out * and are no longer the correct type. XXX */ for (n = 0, qs = qp->q_addr; (u_int)n < qp->q_naddr; n++, qs++) { u_long t; ns2 = qs->nsdata; if (!ns2 || ns2 == ns) continue; if (ns2->d_type != T_A || ns2->d_class != qs->ns->d_class) /* XXX */ continue; if (qs->stime.tv_sec) { if (ns2->d_nstime == 0) t = (rtrip * BETA); else t = ns2->d_nstime * BETA + (1 - ALPHA) * rtrip; } else t = ns2->d_nstime * GAMMA; if (t > 65535) t = 65535; ns2->d_nstime = (u_int16_t)t; ns_debug(ns_log_default, 2, "NS #%d %s rtt now %d", n, sin_ntoa(qs->ns_addr), ns2->d_nstime); } } #ifdef BIND_NOTIFY /* * For now, NOTIFY isn't defined for ANCOUNT!=0, AUCOUNT!=0, * or ADCOUNT!=0. Therefore the only real work to be done for * a NOTIFY-QR is to remove it from the query queue. */ if (hp->opcode == NS_NOTIFY_OP) { qremove(qp); return; } #endif /* * Non-authoritative, no answer, no error, with referral. */ if (hp->rcode == NOERROR && !hp->aa && ancount == 0 && aucount > 0 #ifdef BIND_NOTIFY && hp->opcode != NS_NOTIFY_OP #endif ) { u_char *tp; int type, class; #ifdef DEBUG if (debug > 0) fp_nquery(msg, msglen, log_get_stream(packet_channel)); #endif /* * Since there is no answer section (ancount == 0), * we must be pointing at the authority section (aucount > 0). */ tp = cp; n = dn_expand(msg, eom, tp, name, sizeof name); if (n < 0) { formerrmsg = expandFailedAuth; goto formerr; } tp += n; if (tp + 2 * INT16SZ > eom) { formerrmsg = outofDataAuth; goto formerr; } GETSHORT(type, tp); GETSHORT(class, tp); if (!ns_nameok(name, class, NULL, response_trans, ns_ownercontext(type, response_trans), name, from.sin_addr)) { formerrmsg = badNameFound; goto refused; } /* * If the answer delegates us either to the same level in * the hierarchy or closer to the root, we consider this * server lame. Note that for now we only log the message * if the T_NS was C_IN, which is technically wrong (NS is * visible in all classes) but necessary anyway (non-IN * classes tend to not have good strong delegation graphs). */ if (type == T_NS && samedomain(qp->q_domain, name)) { nameserIncr(from.sin_addr, nssRcvdLDel); /* mark server as bad */ if (!qp->q_fwd) for (i = 0; i < (int)qp->q_naddr; i++) if (ina_equal(qp->q_addr[i].ns_addr.sin_addr, from.sin_addr)) qp->q_addr[i].nretry = MAXRETRY; if (class == C_IN && !haveComplained(ina_ulong(from.sin_addr), nhash(qp->q_domain))) { char *learnt_from = learntFrom(qp, &from); ns_info(ns_log_lame_servers, "Lame server on '%s' (in '%s'?): %s%s", qname, qp->q_domain, sin_ntoa(from), (learnt_from == NULL) ? "" : learnt_from); if (learnt_from != NULL) freestr(learnt_from); } /* XXX - doesn't handle responses sent from the wrong * interface on a multihomed server */ if (qp->q_fwd || ina_equal(qp->q_addr[qp->q_curaddr].ns_addr.sin_addr, from.sin_addr)) retry(qp); return; } } if (qp->q_flags & Q_ZSERIAL) { if (hp->aa && ancount > 0 && hp->rcode == NOERROR && qtype == T_SOA && ((qclass == C_IN) || (qclass == C_HS))) { int n; u_int type, class, dlen; u_int32_t serial; u_char *tp = cp; u_char *rdatap; n = dn_expand(msg, eom, tp, name, sizeof name); if (n < 0) { formerrmsg = expandFailedAnswer; goto formerr; } tp += n; /* name */ if (tp + 3 * INT16SZ + INT32SZ > eom) { formerrmsg = outofDataAnswer; goto formerr; } GETSHORT(type, tp); /* type */ GETSHORT(class, tp); /* class */ tp += INT32SZ; /* ttl */ GETSHORT(dlen, tp); /* dlen */ rdatap = tp; /* start of rdata */ if (!ns_nameok(name, class, NULL, response_trans, ns_ownercontext(type, response_trans), name, from.sin_addr)) { formerrmsg = badNameFound; goto refused; } if (strcasecmp(qname, name) || qtype != type || qclass != class) { sprintf(msgbuf, "qserial answer mismatch (%s %s %s)", name, p_class(class), p_type(type)); formerrmsg = msgbuf; goto formerr; } if (0 >= (n = dn_skipname(tp, eom))) { formerrmsg = skipnameFailedAnswer; goto formerr; } tp += n; /* mname */ if (0 >= (n = dn_skipname(tp, eom))) { formerrmsg = skipnameFailedAnswer; goto formerr; } tp += n; /* rname */ if (tp + 5 * INT32SZ > eom) { formerrmsg = dlenUnderrunAnswer; goto formerr; } GETLONG(serial, tp); tp += 4 * INT32SZ; /* Skip rest of SOA. */ if ((u_int)(tp - rdatap) != dlen) { formerrmsg = dlenOverrunAnswer; goto formerr; } qserial_answer(qp, serial, from); qremove(qp); } else { retry(qp); } return; } /* * Add the info received in the response to the data base. */ arfirst = ancount + aucount; c = arfirst + arcount; /* -ve $ing non-existence of record, must handle non-authoritative * NOERRORs with c == 0. */ if (!hp->aa && hp->rcode == NOERROR && c == 0) goto return_msg; if (qp->q_flags & Q_SYSTEM) dbflags = DB_NOTAUTH | DB_NODATA; else dbflags = DB_NOTAUTH | DB_NODATA | DB_NOHINTS; count = c; if (qp->q_flags & Q_PRIMING) dbflags |= DB_PRIMING; if (hp->tc) { count -= arcount; /* truncation had to affect this */ if (!arcount) { count -= aucount; /* guess it got this too */ } if (!(arcount || aucount)) { count -= ancount; /* things are pretty grim */ } /* retry using tcp provided this was not a tcp query */ if (!(qp->q_flags & Q_USEVC)) { qp->q_flags |= Q_USEVC; unsched(qp); schedretry(qp, 60); if (tcp_send(qp) != NOERROR) /* * We're probably in trouble if tcp_send * failed, but we'll try to press on because * there isn't anything else to do. */ retry(qp); return; } else if (!qsp) { /* outstanding udp response */ return; } /* XXX truncated tcp response */ ns_error(ns_log_default, "ns_resp: TCP truncated: \"%s\" %s %s", qname, p_class(qclass), p_type(qtype)); /* mark this server as bad */ if (!qp->q_fwd) for (i = 0; i < (int)qp->q_naddr; i++) if (ina_equal(qp->q_addr[i].ns_addr.sin_addr, from.sin_addr)) qp->q_addr[i].nretry = MAXRETRY; /* try another server, it may have a bigger write buffer */ retry(qp); return; } tp = cp; restart = 0; validanswer = 0; nscount = 0; cname = 0; lastwascname = 0; externalcname = 0; strcpy(aname, qname); if (count) { /* allocate 1 extra record for end of set detection */ flushset_size = (count + 1) * sizeof *flushset; flushset = memget(flushset_size); if (flushset == NULL) panic("flushset: out of memory", NULL); memset(flushset, 0, flushset_size); } else flushset = NULL; for (i = 0; i < count; i++) { struct databuf *dp; int type; freestr_maybe(&tname); if (cp >= eom) { free_related_additional(); if (flushset != NULL) free_flushset(flushset, flushset_size); formerrmsg = outofDataFinal; goto formerr; } n = rrextract(msg, msglen, cp, &dp, name, sizeof name, from, &tname); if (n < 0) { free_related_additional(); freestr_maybe(&tname); if (flushset != NULL) free_flushset(flushset, flushset_size); formerrmsg = outofDataFinal; if (hp->rcode == REFUSED) goto refused; else goto formerr; } cp += n; if (!dp) continue; type = dp->d_type; if (i < ancount) { /* Answer section. */ if (externalcname || strcasecmp(name, aname) != 0) { if (!externalcname) ns_info(ns_log_resp_checks, "wrong ans. name (%s != %s)", name[0] ? name : ".", aname[0] ? aname : "."); else ns_debug(ns_log_resp_checks, 3, "ignoring answer '%s' after external cname", name); db_freedata(dp); continue; } if (type == T_CNAME && qtype != T_CNAME && qtype != T_ANY) { strcpy(aname, (char *)dp->d_data); if (!samedomain(aname, qp->q_domain)) externalcname = 1; cname++; lastwascname = 1; } else { validanswer = 1; lastwascname = 0; } if (tname != NULL) { add_related_additional(tname); tname = NULL; } dp->d_cred = (hp->aa && !strcasecmp(name, qname)) ? DB_C_AUTH : DB_C_ANSWER; } else { /* After answer section. */ if (lastwascname) { ns_debug(ns_log_resp_checks, 3, "last was cname, ignoring auth. and add."); db_freedata(dp); break; } if (i < arfirst) { /* Authority section. */ switch (type) { case T_NS: case T_SOA: if (!samedomain(aname, name)){ ns_info(ns_log_resp_checks, "bad referral (%s !< %s)", aname[0] ? aname : ".", name[0] ? name : "."); db_freedata(dp); continue; } else if (!samedomain(name, qp->q_domain)) { if (!externalcname) ns_info(ns_log_resp_checks, "bad referral (%s !< %s)", name[0] ? name : ".", qp->q_domain[0] ? qp->q_domain : "."); db_freedata(dp); continue; } if (type == T_NS) { nscount++; add_related_additional(tname); tname = NULL; } break; case T_NXT: /* XXX check */ break; case T_SIG: /* XXX check that it relates to an NS or SOA or NXT */ break; default: ns_info(ns_log_resp_checks, "invalid RR type '%s' in authority section (name = '%s') from %s", p_type(type), name, sin_ntoa(from)); db_freedata(dp); continue; } } else { /* Additional section. */ switch (type) { case T_A: case T_AAAA: if (externalcname || !samedomain(name, qp->q_domain)) { ns_debug(ns_log_resp_checks, 3, "ignoring additional info '%s' type %s", name, p_type(type)); db_freedata(dp); continue; } if (!related_additional(name)) { ns_info(ns_log_resp_checks, "unrelated additional info '%s' type %s from %s", name, p_type(type), sin_ntoa(from)); db_freedata(dp); continue; } break; case T_KEY: /* XXX check? */ break; case T_SIG: /* * XXX a SIG RR should relate * to some other RR in this section, * although if it's the last RR * it might be a transaction signature. */ break; default: ns_info(ns_log_resp_checks, "invalid RR type '%s' in additional section (name = '%s') from %s", p_type(type), name, sin_ntoa(from)); db_freedata(dp); continue; } } dp->d_cred = (qp->q_flags & Q_PRIMING) ? DB_C_ANSWER : DB_C_ADDITIONAL; } rrsetadd(flushset, name, dp); } free_related_additional(); freestr_maybe(&tname); if (flushset != NULL) { rrsetupdate(flushset, dbflags, from); free_flushset(flushset, flushset_size); } if (lastwascname && !externalcname) ns_info(ns_log_cname, "%s (%s)", danglingCname, aname); if (cp > eom) { formerrmsg = outofDataAFinal; goto formerr; } if ((qp->q_flags & Q_SYSTEM) && ancount) { if ((qp->q_flags & Q_PRIMING) && !check_root()) { /* mark server as bad */ if (!qp->q_fwd) for (i = 0; i < (int)qp->q_naddr; i++) if (ina_equal(qp->q_addr[i].ns_addr.sin_addr, from.sin_addr)) qp->q_addr[i].nretry = MAXRETRY; /* XXX - doesn't handle responses sent from * the wronginterface on a multihomed server */ if (qp->q_fwd || qp->q_addr[qp->q_curaddr].ns_addr.sin_addr.s_addr == from.sin_addr.s_addr) retry(qp); return; } ns_debug(ns_log_default, 3, "resp: leaving, SYSQUERY ancount %d", ancount); #ifdef BIND_NOTIFY if (qp->q_notifyzone != DB_Z_CACHE) { struct zoneinfo *zp = &zones[qp->q_notifyzone]; /* Clear this first since sysnotify() might set it. */ qp->q_notifyzone = DB_Z_CACHE; sysnotify(zp->z_origin, zp->z_class, ns_t_soa); } #endif qremove(qp); return; } if (ancount && count && !validanswer) { /* * Everything passed validation but we didn't get the * final answer. The response must have contained * a dangling CNAME. Force a restart of the query. * * Don't set restart if count==0, since this means * the response was truncated in the answer section, * causing us to set count to 0 which will cause * validanswer to be 0 as well even though the answer * section probably contained valid RRs (just not * a complete set). * XXX - this works right if we can just forward this * response to the client, but not if we found a CNAME * in a prior response and restarted the query. */ restart = 1; } /* * An answer to a T_ANY query or a successful answer to a * regular query with no indirection, then just return answer. */ if (!restart && ancount && (qtype == T_ANY || !qp->q_cmsglen)) { ns_debug(ns_log_default, 3, "resp: got as much answer as there is"); goto return_msg; } /* * We might want to cache this negative answer. * * if ancount != 0 and rcode == NOERROR we cannot determine if the * CNAME chain has been processed to completion or not, so just * restart the query. DNS needs a NODATA return code! */ if (((hp->rcode == NXDOMAIN) && (cname == ancount)) || ((hp->rcode == NOERROR) && (ancount == 0) && (nscount == 0))) { cache_n_resp(msg, msglen, from); if (!qp->q_cmsglen) { ns_debug(ns_log_default, 3, "resp: leaving NO: auth = %d", hp->aa); goto return_msg; } forcecmsg = 1; } /* * All messages in here need further processing. i.e. they * are either CNAMEs or we got referred again. */ count = 0; founddata = 0; dname = name; /* * If restart==0 and ancount > 0, we should * have some valid data because because the data in the answer * section is owned by the query name and that passes the * validation test by definition * * XXX - the restart stuff doesn't work if any of the answer RRs * is not cacheable (TTL==0 or unknown RR type), since all of the * answer must pass through the cache and be re-assembled. */ if ((forcecmsg && qp->q_cmsglen) || ((!restart || !cname) && qp->q_cmsglen && ancount)) { ns_debug(ns_log_default, 1, "Cname second pass"); newmsglen = MIN(PACKETSZ, qp->q_cmsglen); memcpy(newmsg, qp->q_cmsg, newmsglen); } else { newmsglen = MIN(PACKETSZ, msglen); memcpy(newmsg, msg, newmsglen); } hp = (HEADER *) newmsg; hp->ancount = htons(0); hp->nscount = htons(0); hp->arcount = htons(0); hp->rcode = NOERROR; dnptrs[0] = newmsg; dnptrs[1] = NULL; cp = newmsg + HFIXEDSZ; /* * Keep in mind that none of this code works when QDCOUNT>1. * cp ends up pointed just past the query section in both cases. */ /* * Arrange for dname to contain the query name. The query * name can be either the original query name if restart==0 * or the target of the last CNAME if we are following a * CNAME chain and were referred. */ n = dn_expand(newmsg, newmsg + newmsglen, cp, dname, sizeof name); if (n < 0) { ns_debug(ns_log_default, 1, "dn_expand failed"); goto servfail; } if (!res_dnok(dname)) { ns_debug(ns_log_default, 1, "bad name (%s)", dname); goto servfail; } cp += n + QFIXEDSZ; buflen = sizeof(newmsg) - (cp - newmsg); cname = 0; try_again: ns_debug(ns_log_default, 1, "resp: nlookup(%s) qtype=%d", dname, qtype); foundname = 0; fname = ""; htp = hashtab; /* lookup relative to root */ np = nlookup(dname, &htp, &fname, 0); ns_debug(ns_log_default, 1, "resp: %s '%s' as '%s' (cname=%d)", np == NULL ? "missed" : "found", dname, fname, cname); if (np == NULL || fname != dname) goto fetch_ns; foundname++; count = cp - newmsg; /* * Look for NXDOMAIN record. */ for (dp = np->n_data; dp; dp = dp->d_next) { if (!stale(dp) && (dp->d_rcode == NXDOMAIN) && (dp->d_class == (int)qclass)) { #ifdef RETURNSOA n = finddata(np, qclass, T_SOA, hp, &dname, &buflen, &count); if ( n != 0) { if (count) { cp += n; buflen -= n; newmsglen += n; hp->nscount = htons((u_int16_t)count); } if (hp->rcode == NOERROR_NODATA) { hp->rcode = NOERROR; goto return_newmsg; } } #endif hp->rcode = NXDOMAIN; /* * XXX forcing AA all the time isn't right, but * we have to work that way by default * for compatibility with older servers. */ if (!NS_OPTION_P(OPTION_NONAUTH_NXDOMAIN)) hp->aa = 1; ns_debug(ns_log_default, 3, "resp: NXDOMAIN aa = %d", hp->aa); goto return_newmsg; } } n = finddata(np, qclass, qtype, hp, &dname, &buflen, &count); if (n == 0) goto fetch_ns; /* NO data available */ if (hp->rcode) { if (hp->rcode == NOERROR_NODATA) hp->rcode = NOERROR; #ifdef RETURNSOA if (count) { cp += n; buflen -= n; hp->nscount = htons((u_int16_t)count); } #endif goto return_newmsg; } cp += n; buflen -= n; hp->ancount = htons(ntohs(hp->ancount) + (u_int16_t)count); if (fname != dname && qtype != T_CNAME && qtype != T_ANY) { cname++; goto try_again; } founddata = 1; ns_debug(ns_log_default, 3, "resp: foundname=%d, count=%d, founddata=%d, cname=%d", foundname, count, founddata, cname); fetch_ns: if (hp->tc) goto return_newmsg; /* * Look for name servers to refer to and fill in the authority * section or record the address for forwarding the query * (recursion desired). */ free_nsp(nsp); switch (findns(&np, qclass, nsp, &count, 0)) { case NXDOMAIN: /* shouldn't happen */ ns_debug(ns_log_default, 3, "req: leaving (%s, rcode %d)", dname, hp->rcode); if (!foundname) hp->rcode = NXDOMAIN; if (qclass != C_ANY) { hp->aa = 1; if (np && (!foundname || !founddata)) { n = doaddauth(hp, cp, buflen, np, nsp[0]); cp += n; buflen -= n; } } goto return_newmsg; case SERVFAIL: goto servfail; } if (founddata) { hp = (HEADER *)newmsg; n = add_data(np, nsp, cp, buflen, &count); if (n < 0) { hp->tc = 1; n = (-n); } cp += n; buflen -= n; hp->nscount = htons((u_int16_t)count); goto return_newmsg; } /* * If we get here, we don't have the answer yet and are about * to iterate to try and get it. First, infinite loop avoidance. */ if (qp->q_nqueries++ > MAXQUERIES) { ns_debug(ns_log_default, 1, "resp: MAXQUERIES exceeded (%s %s %s)", dname, p_class(qclass), p_type(qtype)); ns_info(ns_log_default, "MAXQUERIES exceeded, possible data loop in resolving (%s)", dname); goto servfail; } /* Reset the query control structure */ ns_freeqns(qp, "ns_resp"); qp->q_naddr = 0; qp->q_curaddr = 0; qp->q_fwd = server_options->fwdtab; if (qp->q_domain != NULL) freestr(qp->q_domain); getname(np, tmpdomain, sizeof tmpdomain); qp->q_domain = savestr(tmpdomain, 1); if ((n = nslookup(nsp, qp, dname, "ns_resp")) <= 0) { if (n < 0) { ns_debug(ns_log_default, 3, "resp: nslookup reports danger"); if (cname) /* a remote CNAME that does not have data */ goto return_newmsg; goto servfail; } else { ns_debug(ns_log_default, 3, "resp: no addrs found for NS's"); /* * Timeout while sysquery looks up the NS addresses. * * Hopefully we'll have them when the client asks * again. * * too bad we can't just wait for the sysquery * response to restart this query (it's too hard). * * We could try to crawl back up the tree looking * for reachable servers, but we may have just * gotten delegated down here by a response with * no A RRs for the servers. If we blindly tried * this strategy, we bang on the same server forever. */ goto timeout; } } for (n = 0; (u_int)n < qp->q_naddr; n++) qp->q_addr[n].stime.tv_sec = 0; if (!qp->q_fwd) qp->q_addr[0].stime = tt; if (cname) { if (qp->q_cname++ == MAXCNAMES) { ns_debug(ns_log_default, 3, "resp: leaving, MAXCNAMES exceeded"); goto servfail; } ns_debug(ns_log_default, 1, "q_cname = %d", qp->q_cname); ns_debug(ns_log_default, 3, "resp: building recursive query; nslookup"); if (qp->q_cmsg == NULL) { qp->q_cmsg = qp->q_msg; qp->q_cmsglen = qp->q_msglen; qp->q_cmsgsize = qp->q_msgsize; } else if (qp->q_msg != NULL) memput(qp->q_msg, qp->q_msgsize); qp->q_msg = (u_char *)memget(PACKETSZ); if (qp->q_msg == NULL) { ns_notice(ns_log_default, "resp: memget error"); goto servfail; } qp->q_msgsize = PACKETSZ; n = res_mkquery(QUERY, dname, qclass, qtype, NULL, 0, NULL, qp->q_msg, PACKETSZ); if (n < 0) { ns_info(ns_log_default, "resp: res_mkquery(%s) failed", dname); goto servfail; } if (qp->q_name != NULL) freestr(qp->q_name); qp->q_name = savestr(dname, 1); qp->q_msglen = n; hp = (HEADER *) qp->q_msg; hp->rd = 0; } else hp = (HEADER *) qp->q_msg; hp->id = qp->q_nsid = htons(nsid_next()); if (qp->q_fwd) hp->rd = 1; unsched(qp); schedretry(qp, retrytime(qp)); nsa = Q_NEXTADDR(qp, 0); ns_debug(ns_log_default, 1, "resp: forw -> %s ds=%d nsid=%d id=%d %dms", sin_ntoa(*nsa), ds, ntohs(qp->q_nsid), ntohs(qp->q_id), (qp->q_addr[0].nsdata != NULL) ? qp->q_addr[0].nsdata->d_nstime : -1); #ifdef DEBUG if (debug >= 10) fp_nquery(qp->q_msg, qp->q_msglen, log_get_stream(packet_channel)); #endif if (qp->q_flags & Q_USEVC) { if (tcp_send(qp) != NOERROR) { if (!haveComplained(ina_ulong(nsa->sin_addr), (u_long)tcpsendStr)) ns_info(ns_log_default, "ns_forw: tcp_send(%s) failed: %s", sin_ntoa(*nsa), strerror(errno)); } } else if (sendto(ds, (char*)qp->q_msg, qp->q_msglen, 0, (struct sockaddr *)nsa, sizeof(struct sockaddr_in)) < 0) { if (!haveComplained(ina_ulong(nsa->sin_addr), (u_long)sendtoStr)) ns_info(ns_log_default, "ns_resp: sendto(%s): %s", sin_ntoa(*nsa), strerror(errno)); nameserIncr(nsa->sin_addr, nssSendtoErr); } hp->rd = 0; /* leave set to 0 for dup detection */ nameserIncr(nsa->sin_addr, nssSentFwdR); nameserIncr(qp->q_from.sin_addr, nssRcvdFwdR); ns_debug(ns_log_default, 3, "resp: Query sent."); free_nsp(nsp); return; formerr: if (!haveComplained(ina_ulong(from.sin_addr), (u_long)formerrmsg)) ns_info(ns_log_resp_checks, "Malformed response from %s (%s)", sin_ntoa(from), formerrmsg); free_nsp(nsp); return; return_msg: nameserIncr(from.sin_addr, nssRcvdFwdR); nameserIncr(qp->q_from.sin_addr, nssSentFwdR); /* The "standard" return code */ hp->qr = 1; hp->id = qp->q_id; hp->rd = 1; hp->ra = (NS_OPTION_P(OPTION_NORECURSE) == 0); (void) send_msg(msg, msglen, qp); qremove(qp); free_nsp(nsp); return; return_newmsg: nameserIncr(qp->q_from.sin_addr, nssSentAns); if (!hp->aa) nameserIncr(qp->q_from.sin_addr, nssSentNaAns); if (hp->rcode == NXDOMAIN) nameserIncr(qp->q_from.sin_addr, nssSentNXD); n = doaddinfo(hp, cp, buflen); cp += n; buflen -= n; hp->qr = 1; hp->id = qp->q_id; hp->rd = 1; hp->ra = (NS_OPTION_P(OPTION_NORECURSE) == 0); (void) send_msg(newmsg, cp - newmsg, qp); qremove(qp); free_nsp(nsp); return; refused: hp = (HEADER *)(qp->q_cmsglen ? qp->q_cmsg : qp->q_msg); hp->rcode = REFUSED; hp->qr = 1; hp->id = qp->q_id; hp->rd = 1; hp->ra = (NS_OPTION_P(OPTION_NORECURSE) == 0); (void) send_msg((u_char *)hp, (qp->q_cmsglen ? qp->q_cmsglen : qp->q_msglen), qp); qremove(qp); free_nsp(nsp); return; servfail: nameserIncr(qp->q_from.sin_addr, nssSentFail); hp = (HEADER *)(qp->q_cmsglen ? qp->q_cmsg : qp->q_msg); hp->rcode = SERVFAIL; hp->qr = 1; hp->id = qp->q_id; hp->rd = 1; hp->ra = (NS_OPTION_P(OPTION_NORECURSE) == 0); (void) send_msg((u_char *)hp, (qp->q_cmsglen ? qp->q_cmsglen : qp->q_msglen), qp); qremove(qp); free_nsp(nsp); return; timeout: if (qp->q_stream) sq_remove(qp->q_stream); qremove(qp); free_nsp(nsp); return; } #define BOUNDS_CHECK(ptr, count) \ do { \ if ((ptr) + (count) > eom) { \ hp->rcode = FORMERR; \ return (-1); \ } \ } while (0) static int rrextract(u_char *msg, int msglen, u_char *rrp, struct databuf **dpp, char *dname, int namelen, struct sockaddr_in from, char **tnamep) { u_char *cp, *eom, *rdatap; u_int class, type, dlen; int n, n1; u_int32_t ttl; u_char *cp1, data[MAXDATA*2]; HEADER *hp = (HEADER *)msg; enum context context; if (tnamep != NULL) *tnamep = NULL; *dpp = NULL; cp = rrp; eom = msg + msglen; if ((n = dn_expand(msg, eom, cp, dname, namelen)) < 0) { hp->rcode = FORMERR; return (-1); } cp += n; BOUNDS_CHECK(cp, 2*INT16SZ + INT32SZ + INT16SZ); GETSHORT(type, cp); GETSHORT(class, cp); GETLONG(ttl, cp); if (ttl > MAXIMUM_TTL) { ns_debug(ns_log_default, 5, "%s: converted TTL > %u to 0", dname, MAXIMUM_TTL); ttl = 0; } GETSHORT(dlen, cp); BOUNDS_CHECK(cp, dlen); rdatap = cp; if (!ns_nameok(dname, class, NULL, response_trans, ns_ownercontext(type, response_trans), dname, from.sin_addr)) { hp->rcode = REFUSED; return (-1); } ns_debug(ns_log_default, 3, "rrextract: dname %s type %d class %d ttl %d", dname, type, class, ttl); /* * Convert the resource record data into the internal * database format. * * On entry to the switch: * CP points to the RDATA section of the wire-format RR. * DLEN is its length. * The memory area at DATA is available for processing. * * On exit from the switch: * CP has been incremented past the RR. * CP1 points to the RDATA section of the database-format RR. * N contains the length of the RDATA section of the dbase-format RR. * * The new data at CP1 for length N will be copied into the database, * so it need not be in any particular storage location. */ switch (type) { case T_A: if (dlen != INT32SZ) { hp->rcode = FORMERR; return (-1); } /*FALLTHROUGH*/ case T_WKS: case T_HINFO: case T_TXT: case T_X25: case T_ISDN: case T_NSAP: case T_AAAA: case T_LOC: case T_KEY: cp1 = cp; n = dlen; cp += n; break; case T_CNAME: case T_MB: case T_MG: case T_MR: case T_NS: case T_PTR: n = dn_expand(msg, eom, cp, (char *)data, sizeof data); if (n < 0) { hp->rcode = FORMERR; return (-1); } if (!ns_nameok((char *)data, class, NULL, response_trans, type == T_PTR ?ns_ptrcontext(dname) :domain_ctx, dname, from.sin_addr)) { hp->rcode = FORMERR; return (-1); } cp += n; cp1 = data; n = strlen((char *)data) + 1; if (tnamep != NULL && (type == T_NS || type == T_MB)) *tnamep = savestr((char *)cp1, 1); break; case T_SOA: context = hostname_ctx; goto soa_rp_minfo; case T_RP: case T_MINFO: context = mailname_ctx; /* FALLTHROUGH */ soa_rp_minfo: n = dn_expand(msg, eom, cp, (char *)data, sizeof data); if (n < 0) { hp->rcode = FORMERR; return (-1); } if (!ns_nameok((char *)data, class, NULL, response_trans, context, dname, from.sin_addr)) { hp->rcode = FORMERR; return (-1); } cp += n; /* * The next use of 'cp' is dn_expand(), so we don't have * to BOUNDS_CHECK() here. */ cp1 = data + (n = strlen((char *)data) + 1); n1 = sizeof(data) - n; if (type == T_SOA) n1 -= 5 * INT32SZ; n = dn_expand(msg, eom, cp, (char *)cp1, n1); if (n < 0) { hp->rcode = FORMERR; return (-1); } if (type == T_RP) context = domain_ctx; else context = mailname_ctx; if (!ns_nameok((char *)cp1, class, NULL, response_trans, context, dname, from.sin_addr)) { hp->rcode = FORMERR; return (-1); } cp += n; cp1 += strlen((char *)cp1) + 1; if (type == T_SOA) { n = 5 * INT32SZ; BOUNDS_CHECK(cp, n); memcpy(cp1, cp, n); cp += n; cp1 += n; } n = cp1 - data; cp1 = data; break; case T_NAPTR: /* Grab weight and port. */ BOUNDS_CHECK(cp, INT16SZ*2); memcpy(data, cp, INT16SZ*2); cp1 = data + INT16SZ*2; cp += INT16SZ*2; /* Flags */ BOUNDS_CHECK(cp, 1); n = *cp++; BOUNDS_CHECK(cp, n); *cp1++ = n; memcpy(cp1, cp, n); cp += n; cp1 += n; /* Service */ BOUNDS_CHECK(cp, 1); n = *cp++; BOUNDS_CHECK(cp, n); *cp1++ = n; memcpy(cp1, cp, n); cp += n; cp1 += n; /* Regexp */ BOUNDS_CHECK(cp, 1); n = *cp++; BOUNDS_CHECK(cp, n); *cp1++ = n; memcpy(cp1, cp, n); cp += n; cp1 += n; /* Replacement */ n = dn_expand(msg, eom, cp, (char *)cp1, sizeof data - (cp1 - data)); if (n < 0) { hp->rcode = FORMERR; return (-1); } if (!ns_nameok((char *)cp1, class, NULL, response_trans, hostname_ctx, dname, from.sin_addr)) { hp->rcode = FORMERR; return (-1); } cp += n; /* compute end of data */ cp1 += strlen((char *)cp1) + 1; /* compute size of data */ n = cp1 - data; cp1 = data; break; case T_MX: case T_AFSDB: case T_RT: case T_SRV: /* grab preference */ BOUNDS_CHECK(cp, INT16SZ); memcpy(data, cp, INT16SZ); cp1 = data + INT16SZ; cp += INT16SZ; if (type == T_SRV) { /* Grab weight and port. */ BOUNDS_CHECK(cp, INT16SZ*2); memcpy(cp1, cp, INT16SZ*2); cp1 += INT16SZ*2; cp += INT16SZ*2; } /* get name */ n = dn_expand(msg, eom, cp, (char *)cp1, sizeof data - (cp1 - data)); if (n < 0) { hp->rcode = FORMERR; return (-1); } if (!ns_nameok((char *)cp1, class, NULL, response_trans, hostname_ctx, dname, from.sin_addr)) { hp->rcode = FORMERR; return (-1); } cp += n; if (tnamep != NULL) *tnamep = savestr((char *)cp1, 1); /* compute end of data */ cp1 += strlen((char *)cp1) + 1; /* compute size of data */ n = cp1 - data; cp1 = data; break; case T_PX: /* grab preference */ BOUNDS_CHECK(cp, INT16SZ); memcpy(data, cp, INT16SZ); cp1 = data + INT16SZ; cp += INT16SZ; /* get MAP822 name */ n = dn_expand(msg, eom, cp, (char *)cp1, sizeof data - INT16SZ); if (n < 0) { hp->rcode = FORMERR; return (-1); } if (!ns_nameok((char *)cp1, class, NULL, response_trans, domain_ctx, dname, from.sin_addr)) { hp->rcode = FORMERR; return (-1); } cp += n; /* * The next use of 'cp' is dn_expand(), so we don't have * to BOUNDS_CHECK() here. */ cp1 += (n = strlen((char *)cp1) + 1); n1 = sizeof(data) - n; n = dn_expand(msg, eom, cp, (char *)cp1, n1); if (n < 0) { hp->rcode = FORMERR; return (-1); } if (!ns_nameok((char *)cp1, class, NULL, response_trans, domain_ctx, dname, from.sin_addr)) { hp->rcode = FORMERR; return (-1); } cp += n; cp1 += strlen((char *)cp1) + 1; n = cp1 - data; cp1 = data; break; case T_SIG: { u_long origTTL, exptime, signtime, timetilexp, now; /* Check signature time, expiration, and adjust TTL. */ /* This code is similar to that in db_load.c. */ /* Skip coveredType, alg, labels */ BOUNDS_CHECK(cp, INT16SZ + 1 + 1 + 3*INT32SZ); cp1 = cp + INT16SZ + 1 + 1; GETLONG(origTTL, cp1); GETLONG(exptime, cp1); GETLONG(signtime, cp1); now = time(NULL); /* Get current time in GMT/UTC */ /* Don't let bogus name servers increase the signed TTL */ if (ttl > origTTL) { ns_debug(ns_log_default, 3, "shrinking SIG TTL from %d to origTTL %d", ttl, origTTL); ttl = origTTL; } /* Don't let bogus signers "sign" in the future. */ if (signtime > now) { ns_debug(ns_log_default, 3, "ignoring SIG: signature date %s is in the future", p_secstodate (signtime)); return ((cp - rrp) + dlen); } /* Ignore received SIG RR's that are already expired. */ if (exptime <= now) { ns_debug(ns_log_default, 3, "ignoring SIG: expiration %s is in the past", p_secstodate (exptime)); return ((cp - rrp) + dlen); } /* Lop off the TTL at the expiration time. */ timetilexp = exptime - now; if (timetilexp < ttl) { ns_debug(ns_log_default, 3, "shrinking expiring %s SIG TTL from %d to %d", p_secstodate (exptime), ttl, timetilexp); ttl = timetilexp; } /* The following code is copied from named-xfer.c. */ cp1 = (u_char *)data; /* first just copy over the type_covered, algorithm, */ /* labels, orig ttl, two timestamps, and the footprint */ BOUNDS_CHECK(cp, 18); memcpy(cp1, cp, 18); cp += 18; cp1 += 18; /* then the signer's name */ n = dn_expand(msg, eom, cp, (char *)cp1, (sizeof data) - 18); if (n < 0) { hp->rcode = FORMERR; return (-1); } cp += n; cp1 += strlen((char*)cp1)+1; /* finally, we copy over the variable-length signature. Its size is the total data length, minus what we copied. */ if (18 + (u_int)n > dlen) { hp->rcode = FORMERR; return (-1); } n = dlen - (18 + n); if (n > ((int)(sizeof data) - (int)(cp1 - (u_char *)data))) { hp->rcode = FORMERR; return (-1); /* out of room! */ } memcpy(cp1, cp, n); cp += n; cp1 += n; /* compute size of data */ n = cp1 - (u_char *)data; cp1 = (u_char *)data; break; } default: ns_debug(ns_log_default, 3, "unknown type %d", type); return ((cp - rrp) + dlen); } if (cp > eom) { hp->rcode = FORMERR; return (-1); } if ((u_int)(cp - rdatap) != dlen) { ns_debug(ns_log_default, 3, "encoded rdata length is %u, but actual length was %u", dlen, (u_int)(cp - rdatap)); hp->rcode = FORMERR; return (-1); } if (n > MAXDATA) { ns_debug(ns_log_default, 1, "update type %d: %d bytes is too much data", type, n); hp->rcode = FORMERR; return (-1); } ttl += tt.tv_sec; *dpp = savedata(class, type, ttl, cp1, n); return (cp - rrp); } int send_msg(u_char *msg, int msglen, struct qinfo *qp) { if (qp->q_flags & Q_SYSTEM) return (1); if (!qp->q_stream && (msglen > PACKETSZ)) msglen = trunc_adjust(msg, msglen, PACKETSZ); ns_debug(ns_log_default, 1, "send_msg -> %s (%s %d) id=%d", sin_ntoa(qp->q_from), qp->q_stream == NULL ? "UDP" : "TCP", qp->q_stream == NULL ? qp->q_dfd : qp->q_stream->s_rfd, ntohs(qp->q_id)); #ifdef DEBUG if (debug > 4) { struct qinfo *tqp; for (tqp = nsqhead; tqp != NULL; tqp = tqp->q_link) { ns_debug(ns_log_default, 4, "qp %#lx q_id: %d q_nsid: %d q_msglen: %d", (u_long)tqp, tqp->q_id, tqp->q_nsid, tqp->q_msglen); ns_debug(ns_log_default, 4, "\tq_naddr: %d q_curaddr: %d", tqp->q_naddr, tqp->q_curaddr); ns_debug(ns_log_default, 4, "\tq_next: %#lx q_link: %#lx", (u_long)qp->q_next, (u_long)qp->q_link); } } if (debug >= 6) fp_nquery(msg, msglen, log_get_stream(packet_channel)); #endif /* DEBUG */ if (qp->q_stream == NULL) { if (sendto(qp->q_dfd, (char*)msg, msglen, 0, (struct sockaddr *)&qp->q_from, sizeof(qp->q_from)) < 0) { if (!haveComplained(ina_ulong(qp->q_from.sin_addr), (u_long)sendtoStr)) #if defined(SPURIOUS_ECONNREFUSED) if (errno != ECONNREFUSED) #endif ns_info(ns_log_default, "send_msg: sendto(%s): %s", sin_ntoa(qp->q_from), strerror(errno)); nameserIncr(qp->q_from.sin_addr, nssSendtoErr); return (1); } } else writestream(qp->q_stream, (u_char*)msg, msglen); return (0); } #ifdef notdef /* i don't quite understand this but the only ref to it is notdef'd --vix */ prime(class, type, oqp) int class, type; struct qinfo *oqp; { char dname[MAXDNAME]; if (oqp->q_msg == NULL) return; if (dn_expand((u_char *)oqp->q_msg, (u_char *)oqp->q_msg + oqp->q_msglen, (u_char *)oqp->q_msg + HFIXEDSZ, (u_char *)dname, sizeof(dname)) < 0) return; ns_debug(ns_log_default, 2, "prime: %s", dname); (void) sysquery(dname, class, type, NULL, 0, QUERY); } #endif void prime_cache() { struct qinfo *qp; /* * XXX - should this always be skipped if OPTION_FORWARD_ONLY * or should it be another option? What about when we are * doing selective forwarding? */ if (!NS_OPTION_P(OPTION_FORWARD_ONLY)) { ns_debug(ns_log_default, 1, "prime_cache: priming = %d", priming); if (!priming && fcachetab->h_tab[0] != NULL) { priming++; if (!(qp = sysquery("", C_IN, T_NS, NULL, 0, QUERY))) priming = 0; else qp->q_flags |= (Q_SYSTEM | Q_PRIMING); } } needs_prime_cache = 0; return; } #ifdef BIND_NOTIFY /* * sysnotify(dname, class, type) * cause a NOTIFY request to be sysquery()'d to each secondary server * of the zone that "dname" is within. */ void sysnotify(const char *dname, int class, int type) { const char *zname, *fname; int nns, na, zn, n; struct zoneinfo *zp; struct hashbuf *htp; struct namebuf *np; struct databuf *dp; ns_debug(ns_log_notify, 3, "sysnotify(%s, %s, %s)", dname, p_class(class), p_type(type)); htp = hashtab; np = nlookup(dname, &htp, &fname, 0); if (np == NULL) { ns_warning(ns_log_notify, "sysnotify: can't find \"%s\"", dname); return; } zn = findMyZone(np, class); if (zn == DB_Z_CACHE) { ns_warning(ns_log_notify, "sysnotify: not auth for zone %s", dname); return; } zp = &zones[zn]; if (zp->z_notify == znotify_no || (zp->z_notify == znotify_use_default && NS_OPTION_P(OPTION_NONOTIFY))) return; if (zp->z_type != z_master && zp->z_type != z_slave) { ns_warning(ns_log_notify, "sysnotify: %s not master or slave", dname); return; } zname = zp->z_origin; nns = na = 0; if (zp->z_type == z_master) sysnotify_slaves(dname, zname, class, zn, &nns, &na); if (zp->z_notify_count != 0) { struct in_addr *also_addr = zp->z_also_notify; int i; for (i = 0; i < zp->z_notify_count; i++) { sysquery(dname, class, T_SOA, also_addr, 1, NS_NOTIFY_OP); also_addr++; } nns += zp->z_notify_count; na += zp->z_notify_count; } if (nns != 0 || na != 0) ns_info(ns_log_notify, "Sent NOTIFY for \"%s %s %s\" (%s); %d NS, %d A", dname, p_class(class), p_type(type), zname, nns, na); } static void sysnotify_slaves(const char *dname, const char *zname, int class, int zn, int *nns, int *na) { const char *mname, *fname; struct hashbuf *htp; struct namebuf *np; struct databuf *dp; /* * Master. */ htp = hashtab; np = nlookup(zname, &htp, &fname, 0); if (!np) { ns_warning(ns_log_notify, "sysnotify: found name \"%s\" but not zone", dname); return; } mname = NULL; for (dp = np->n_data; dp; dp = dp->d_next) { if (dp->d_zone == DB_Z_CACHE || !match(dp, class, T_SOA)) continue; if (mname) { ns_notice(ns_log_notify, "multiple SOA's for zone \"%s\"?", zname); return; } mname = (char *) dp->d_data; } if (mname == NULL) { ns_notice(ns_log_notify, "no SOA found for zone \"%s\"", zname); return; } for (dp = np->n_data; dp != NULL; dp = dp->d_next) { if (dp->d_zone == DB_Z_CACHE || !match(dp, class, T_NS)) continue; if (strcasecmp((char*)dp->d_data, mname) == 0) continue; sysnotify_ns(dname, (char *)dp->d_data, class, zn, nns, na); } } static void sysnotify_ns(const char *dname, const char *aname, int class, int zn, int *nns, int *na) { struct databuf *adp; struct namebuf *anp; const char *fname; struct in_addr nss[NSMAX]; struct hashbuf *htp; int is_us, nsc; htp = hashtab; anp = nlookup(aname, &htp, &fname, 0); nsc = 0; is_us = 0; if (anp != NULL) for (adp = anp->n_data; adp; adp = adp->d_next) { struct in_addr ina; if (!match(adp, class, T_A)) continue; ina = ina_get(adp->d_data); if (aIsUs(ina)) { is_us = 1; continue; } if (nsc < NSMAX) nss[nsc++] = ina; } /*next A*/ if (nsc == 0) { if (!is_us) { struct qinfo *qp; qp = sysquery(aname, class, T_A, 0, 0, QUERY); if (qp != NULL) qp->q_notifyzone = zn; } return; } (void) sysquery(dname, class, T_SOA, nss, nsc, NS_NOTIFY_OP); (*nns)++; *na += nsc; } #endif /*BIND_NOTIFY*/ struct qinfo * sysquery(const char *dname, int class, int type, struct in_addr *nss, int nsc, int opcode) { struct qinfo *qp, *oqp; HEADER *hp; char tmpdomain[MAXDNAME]; struct namebuf *np; struct databuf *nsp[NSMAX]; struct hashbuf *htp; struct sockaddr_in *nsa; const char *fname; int n, count; nsp[0] = NULL; ns_debug(ns_log_default, 3, "sysquery(%s, %d, %d, %#x, %d)", dname, class, type, nss, nsc); qp = qnew(dname, class, type); if (nss && nsc) np = NULL; else { htp = hashtab; if (priming && dname[0] == '\0') { np = NULL; } else if ((np = nlookup(dname, &htp, &fname, 1)) == NULL) { ns_info(ns_log_default, "sysquery: nlookup error on %s?", dname); err1: ns_freeqry(qp); return (NULL); } n = findns(&np, class, nsp, &count, 0); switch (n) { case NXDOMAIN: case SERVFAIL: ns_info(ns_log_default, "sysquery: findns error (%s) on %s?", n == NXDOMAIN ? "NXDOMAIN" : "SERVFAIL", dname); err2: free_nsp(nsp); goto err1; } } /* build new qinfo struct */ qp->q_cmsg = qp->q_msg = NULL; qp->q_dfd = ds; if (nss && nsc) qp->q_fwd = NULL; else qp->q_fwd = server_options->fwdtab; qp->q_expire = tt.tv_sec + RETRY_TIMEOUT*2; qp->q_flags |= Q_SYSTEM; getname(np, tmpdomain, sizeof tmpdomain); qp->q_domain = savestr(tmpdomain, 1); if ((qp->q_msg = (u_char *)memget(PACKETSZ)) == NULL) { ns_notice(ns_log_default, "sysquery: memget failed"); goto err2; } qp->q_msgsize = PACKETSZ; n = res_mkquery(opcode, dname, class, type, NULL, 0, NULL, qp->q_msg, PACKETSZ); if (n < 0) { ns_info(ns_log_default, "sysquery: res_mkquery(%s) failed", dname); goto err2; } qp->q_msglen = n; hp = (HEADER *) qp->q_msg; hp->id = qp->q_nsid = htons(nsid_next()); hp->rd = (qp->q_fwd ? 1 : 0); /* First check for an already pending query for this data */ for (oqp = nsqhead; oqp != NULL; oqp = oqp->q_link) { if ((oqp != qp) && (oqp->q_msglen == qp->q_msglen) && memcmp(oqp->q_msg+2, qp->q_msg + 2, qp->q_msglen - 2) == 0 ) { #ifdef BIND_NOTIFY /* XXX - need fancier test to suppress duplicate * NOTIFYs to the same server (compare nss?) */ if (opcode != NS_NOTIFY_OP) #endif /*BIND_NOTIFY*/ { ns_debug(ns_log_default, 3, "sysquery: duplicate"); goto err2; } } } if (nss && nsc) { int i; struct qserv *qs; for (i = 0, qs = qp->q_addr; i < nsc; i++, qs++) { qs->ns_addr.sin_family = AF_INET; qs->ns_addr.sin_addr = nss[i]; qs->ns_addr.sin_port = ns_port; qs->ns = NULL; qs->nsdata = NULL; qs->stime = tt; qs->nretry = 0; } qp->q_naddr = nsc; } else { fetch_a: count = nslookup(nsp, qp, dname, "sysquery"); if (count <= 0) { if (count < 0) { ns_info(ns_log_default, "sysquery: nslookup reports danger (%s)", dname); goto err2; } else if (np && NAME(*np)[0] == '\0') { /* * It's not too serious if we don't have * the root server addresses if we have to * go through a forwarder anyway. Don't * bother to log it, since prime_cache() * won't do anything about it as currently * implemented. * * XXX - should we skip setting * needs_prime_cache as well? * * XXX - what happens when we implement * selective forwarding? */ if (!NS_OPTION_P(OPTION_FORWARD_ONLY)) ns_warning(ns_log_default, "sysquery: no addrs found for root NS (%s)", dname); if (class == C_IN && !priming) needs_prime_cache = 1; goto err2; } if (np) { free_nsp(nsp); nsp[0] = NULL; np = np_parent(np); n = findns(&np, class, nsp, &count, 0); switch (n) { case NXDOMAIN: /*FALLTHROUGH*/ case SERVFAIL: ns_info(ns_log_default, "sysquery: findns error (%d) on %s?", n, dname); goto err2; } goto fetch_a; } goto err2; } } schedretry(qp, retrytime(qp)); if (qp->q_fwd == NULL) qp->q_addr[0].stime = tt; /* XXX - why not every? */ nsa = Q_NEXTADDR(qp, 0); ns_debug(ns_log_default, 1, "sysquery: send -> %s dfd=%d nsid=%d id=%d retry=%ld", sin_ntoa(*nsa), qp->q_dfd, ntohs(qp->q_nsid), ntohs(qp->q_id), (long)qp->q_time); #ifdef DEBUG if (debug >= 10) fp_nquery(qp->q_msg, qp->q_msglen, log_get_stream(packet_channel)); #endif if (sendto(qp->q_dfd, (char*)qp->q_msg, qp->q_msglen, 0, (struct sockaddr *)nsa, sizeof(struct sockaddr_in)) < 0) { if (!haveComplained(ina_ulong(nsa->sin_addr), (u_long)sendtoStr)) ns_info(ns_log_default, "sysquery: sendto(%s): %s", sin_ntoa(*nsa), strerror(errno)); nameserIncr(nsa->sin_addr, nssSendtoErr); } nameserIncr(nsa->sin_addr, nssSentSysQ); free_nsp(nsp); return (qp); } /* * Check the list of root servers after receiving a response * to a query for the root servers. */ static int check_root() { struct databuf *dp, *pdp; struct namebuf *np; int count = 0; priming = 0; for (np = hashtab->h_tab[0]; np != NULL; np = np->n_next) if (NAME(*np)[0] == '\0') break; if (np == NULL) { ns_notice(ns_log_default, "check_root: Can't find root!"); return (0); } for (dp = np->n_data; dp != NULL; dp = dp->d_next) if (dp->d_type == T_NS) count++; ns_debug(ns_log_default, 1, "%d root servers", count); if (count < MINROOTS) { ns_notice(ns_log_default, "check_root: %d root servers after query to root server < min", count); return (0); } pdp = NULL; dp = np->n_data; while (dp != NULL) { if (dp->d_type == T_NS && dp->d_zone == DB_Z_CACHE && dp->d_ttl < (u_int32_t)tt.tv_sec) { ns_debug(ns_log_default, 1, "deleting old root server '%s'", dp->d_data); dp = rm_datum(dp, np, pdp, NULL); /* SHOULD DELETE FROM HINTS ALSO */ continue; } pdp = dp; dp = dp->d_next; } if (check_ns()) return (1); else { priming = 1; return (0); } } /* * Check the root to make sure that for each NS record we have a A RR */ static int check_ns() { struct databuf *dp, *tdp; struct namebuf *np, *tnp; struct hashbuf *htp; char *dname; int found_arr; const char *fname; time_t curtime; int servers = 0, rrsets = 0; ns_debug(ns_log_default, 2, "check_ns()"); curtime = (u_int32_t) tt.tv_sec; for (np = hashtab->h_tab[0]; np != NULL; np = np->n_next) { if (NAME(*np)[0] != '\0') continue; for (dp = np->n_data; dp != NULL; dp = dp->d_next) { int cnames = 0; if (dp->d_rcode) continue; if (dp->d_type != T_NS) continue; servers++; /* look for A records */ dname = (caddr_t) dp->d_data; htp = hashtab; tnp = nlookup(dname, &htp, &fname, 0); if (tnp == NULL || fname != dname) { ns_debug(ns_log_default, 3, "check_ns: %s: not found %s %#lx", dname, fname, (u_long)tnp); sysquery(dname, dp->d_class, T_A, NULL, 0, QUERY); continue; } /* look for name server addresses */ found_arr = 0; delete_stale(tnp); for (tdp = tnp->n_data; tdp != NULL; tdp = tdp->d_next) { if (tdp->d_rcode) continue; if (tdp->d_type == T_CNAME) cnames++; if (tdp->d_type != T_A || tdp->d_class != dp->d_class) continue; if ((tdp->d_zone == DB_Z_CACHE) && (tdp->d_ttl < (u_int32_t)curtime)) { ns_debug(ns_log_default, 3, "check_ns: stale entry '%s'", NAME(*tnp)); found_arr = 0; break; } found_arr++; } if (found_arr) rrsets++; else if (cnames > 0) ns_info(ns_log_default, "Root NS %s -> CNAME %s", NAME(*np), NAME(*tnp)); else sysquery(dname, dp->d_class, T_A, NULL, 0, QUERY); } } ns_debug(ns_log_default, 2, "check_ns: %d %d", servers, rrsets); return ((servers <= 2) ? (rrsets == servers) : ((rrsets * 2) >= servers) ); } /* int findns(npp, class, nsp, countp, flag) * Find NS's or an SOA * npp, class: * dname whose most enclosing NS is wanted * nsp, countp: * result array and count; array will also be NULL terminated * flag: * boolean: we're being called from ADDAUTH, bypass authority checks * return value: * NXDOMAIN: we are authoritative for this {dname,class} * *countp is bogus, but nsp[] has a single SOA returned in it. * SERVFAIL: we are auth but zone isn't loaded; or, no root servers found * *countp and nsp[] are bogus. * OK: we are not authoritative, and here are the NS records we found. * *countp and nsp[] return NS records of interest. */ int findns(struct namebuf **npp, int class, struct databuf **nsp, int *countp, int flag) { struct namebuf *np = *npp; struct databuf *dp; struct databuf **nspp; struct hashbuf *htp; nsp[0] = NULL; if (priming && (np == NULL || NAME(*np)[0] == '\0')) htp = fcachetab; else htp = hashtab; try_again: if (htp == fcachetab && class == C_IN && !priming) /* * XXX - do we want to set needs_prime_cache if * OPTION_FORWARD_ONLY? */ needs_prime_cache = 1; if (np == NULL) { /* find the root */ for (np = htp->h_tab[0]; np != NULL; np = np->n_next) if (NAME(*np)[0] == '\0') break; } while (np != NULL) { ns_debug(ns_log_default, 5, "findns: np %#x '%s'", np, NAME(*np)); /* Look first for SOA records. */ #ifdef ADDAUTH if (!flag) #endif for (dp = np->n_data; dp != NULL; dp = dp->d_next) { if (dp->d_zone != DB_Z_CACHE && ((zones[dp->d_zone].z_type == Z_PRIMARY) || (zones[dp->d_zone].z_type == Z_SECONDARY)) && match(dp, class, T_SOA)) { ns_debug(ns_log_default, 3, "findns: SOA found"); if (zones[dp->d_zone].z_flags & Z_AUTH) { *npp = np; nsp[0] = dp; nsp[1] = NULL; DRCNTINC(dp); return (NXDOMAIN); } else { /* XXX: zone isn't loaded but we're * primary or secondary for it. * should we fwd this? */ return (SERVFAIL); } } } /* If no SOA records, look for NS records. */ nspp = &nsp[0]; *nspp = NULL; delete_stale(np); for (dp = np->n_data; dp != NULL; dp = dp->d_next) { if (!match(dp, class, T_NS)) continue; if (dp->d_rcode) continue; /* * Don't use records that may become invalid to * reference later when we do the rtt computation. * Never delete our safety-belt information! * * XXX: this is horribly bogus. */ if ((dp->d_zone == DB_Z_CACHE) && (dp->d_ttl < (u_int32_t)tt.tv_sec) && !(dp->d_flags & DB_F_HINT)) { ns_debug(ns_log_default, 1, "findns: stale entry '%s'", NAME(*np)); /* * We may have already added NS databufs * and are going to throw them away. Fix * reference counts. We don't need to free * them here as we just got them from the * cache. */ while (nspp > &nsp[0]) { nspp--; DRCNTDEC(*nspp); } nsp[0] = NULL; goto try_parent; } if (nspp < &nsp[NSMAX-1]) { *nspp++ = dp; DRCNTINC(dp); } } *countp = nspp - nsp; if (*countp > 0) { ns_debug(ns_log_default, 3, "findns: %d NS's added for '%s'", *countp, NAME(*np)); *nspp = NULL; *npp = np; return (OK); /* Success, got some NS's */ } try_parent: np = np_parent(np); } if (htp == hashtab) { htp = fcachetab; goto try_again; } ns_debug(ns_log_default, 1, "findns: No root nameservers for class %s?", p_class(class)); if ((unsigned)class < MAXCLASS && norootlogged[class] == 0) { norootlogged[class] = 1; ns_info(ns_log_default, "No root nameservers for class %s", p_class(class)); } return (SERVFAIL); } /* * Extract RR's from the given node that match class and type. * Return number of bytes added to response. * If no matching data is found, then 0 is returned. */ int finddata(struct namebuf *np, int class, int type, HEADER *hp, char **dnamep, int *lenp, int *countp) { struct databuf *dp; char *cp; int buflen, n, count = 0; delete_stale(np); #ifdef ROUND_ROBIN if (type != T_ANY && type != T_PTR) { /* cycle order of RRs, for a load balancing effect... */ struct databuf **dpp; for (dpp = &np->n_data; (dp = *dpp) != NULL; dpp = &dp->d_next) { if (dp->d_next && wanted(dp, class, type)) { struct databuf *lp; *dpp = lp = dp->d_next; dp->d_next = NULL; for (dpp = &lp->d_next; *dpp; dpp = &lp->d_next) lp = *dpp; *dpp = dp; break; } } } #endif /*ROUND_ROBIN*/ buflen = *lenp; #ifdef DEBUG if (buflen > PACKETSZ) ns_debug(ns_log_default, 1, "finddata(): buflen=%d", buflen); #endif cp = ((char *)hp) + *countp; for (dp = np->n_data; dp != NULL; dp = dp->d_next) { if (!wanted(dp, class, type)) { if (type == T_CNAME && class == dp->d_class) { /* any data means no CNAME exists */ *countp = 0; return 0; } continue; } if (dp->d_cred == DB_C_ADDITIONAL) { #ifdef NOADDITIONAL continue; #else /* we want to expire additional data very * quickly. current strategy is to cut 5% * off each time it is accessed. this makes * stale(dp) true earlier when this datum is * used often. */ dp->d_ttl = tt.tv_sec + 0.95 * (int) (dp->d_ttl - tt.tv_sec); #endif } /* -ve $ing stuff, anant@isi.edu * if we have a -ve $ed record, change the rcode on the * header to reflect that */ if (dp->d_rcode == NOERROR_NODATA) { if (count != 0) { /* * This should not happen, yet it does... */ ns_info(ns_log_default, "NODATA & data for \"%s\" type %d class %d", *dnamep, type, class); continue; } if (type == T_ANY) continue; hp->rcode = NOERROR_NODATA; if (dp->d_size == 0) { /* !RETURNSOA */ *countp = 0; return 1; /* XXX - we have to report success */ } } if (dp->d_rcode == NXDOMAIN) { if (count != 0) { /* * This should not happen, yet it might... */ ns_info(ns_log_default, "NXDOMAIN & data for \"%s\" type %d class %d", *dnamep, type, class); continue; } hp->rcode = NXDOMAIN; if (dp->d_size == 0) { /* !RETURNSOA */ *countp = 0; return 1; /* XXX - we have to report success */ } } /* Don't put anything but key or sig RR's in response to requests for key or sig */ if (((type == T_SIG) || (type == T_KEY)) && (!((dp->d_type == T_SIG) || (dp->d_type == T_KEY))) ) continue; if ((n = make_rr(*dnamep, dp, (u_char *)cp, buflen, 1, dnptrs, dnptrs_end)) < 0) { hp->tc = 1; *countp = count; return (*lenp - buflen); } cp += n; buflen -= n; count++; #ifdef notdef /* this isn't right for glue records, aa is set in ns_req */ if (dp->d_zone != DB_Z_CACHE && (zones[dp->d_zone].z_flags & Z_AUTH) != 0 && class != C_ANY) hp->aa = 1; /* XXX */ #endif if (dp->d_type == T_CNAME) { /* don't alias if querying for key, sig, nxt, or any */ if ((type != T_KEY) && (type != T_SIG) && (type != T_NXT) && (type != T_ANY)) { /* or T_NS? */ *dnamep = (caddr_t) dp->d_data; } break; } } /* * Cache invalidate the other RR's of same type * if some have timed out */ ns_debug(ns_log_default, 3, "finddata: added %d class %d type %d RRs", count, class, type); *countp = count; return (*lenp - buflen); } /* * Do we want this data record based on the class and type? * (We always return found unexpired SIG RR's that cover the wanted rrtype.) */ int wanted(const struct databuf *dp, int class, int type) { const u_char *cp; int coveredType; time_t expiration; #ifdef DEBUG char pclass[15], ptype[15]; #endif #ifdef DEBUG strcpy(pclass, p_class(class)); strcpy(ptype, p_type(type)); ns_debug(ns_log_default, 3, "wanted(%#x, %s %s) [%s %s]", dp, pclass, ptype, p_class(dp->d_class), p_type(dp->d_type)); #endif if (dp->d_class != class && class != C_ANY) return (0); /* * Must check SIG for expiration below, other matches * return OK here. */ if (type == dp->d_type && (type != T_SIG)) return (1); /* For a T_ANY query, we do not want to return -ve $ed RRs. */ if (type == T_ANY && dp->d_rcode == NOERROR_NODATA) return (0); /* First, look at the type of RR. */ switch (dp->d_type) { /* Cases to deal with: T_ANY search, return all unexpired SIGs. T_SIG search, return all unexpired SIGs. T_ search, return all unexp SIG s. */ case T_SIG: cp = dp->d_data; GETSHORT(coveredType, cp); cp += INT16SZ + INT32SZ; /* skip alg, labels, & orig TTL */ GETLONG(expiration,cp); if (type == T_ANY || type == T_SIG || type == coveredType) { if (expiration > time(0)) return (1); /* Unexpired matching SIG */ } return (0); /* We don't return this SIG. */ case T_ANY: return (1); case T_CNAME: if (dp->d_rcode != NOERROR_NODATA) return (1); else break; } /* OK, now look at the type of query. */ switch (type) { case T_ANY: return (1); case T_MAILB: switch (dp->d_type) { case T_MR: case T_MB: case T_MG: case T_MINFO: return (1); } break; case T_AXFR: /* T_AXFR needs an authoritative SOA */ if (dp->d_type == T_SOA && dp->d_zone != DB_Z_CACHE && (zones[dp->d_zone].z_flags & Z_AUTH)) return (1); break; } return (0); } /* * Add RR entries from dpp array to a query/response. * Return the number of bytes added or negative the amount * added if truncation occured. Typically you are * adding NS records to a response. */ int add_data(struct namebuf *np, struct databuf **dpp, u_char *cp, int buflen, int *countp) { struct databuf *dp; char dname[MAXDNAME]; int n, bytes; bytes = *countp = 0; getname(np, dname, sizeof(dname)); for (dp = *dpp++; dp != NULL; dp = *dpp++) { if (stale(dp)) continue; /* ignore old cache entry */ if (dp->d_rcode) continue; if ((n = make_rr(dname, dp, cp, buflen, 1, dnptrs, dnptrs_end)) < 0) return (-bytes); /* Truncation */ cp += n; buflen -= n; bytes += n; (*countp)++; } return (bytes); } static void rrsetadd(struct flush_set *flushset, const char *name, struct databuf *dp) { struct flush_set *fs = flushset; struct db_list *dbl; while (fs->fs_name && ( strcasecmp(fs->fs_name,name) || (fs->fs_class != dp->d_class) || (fs->fs_type != dp->d_type) || (fs->fs_cred != dp->d_cred))) { fs++; } if (!fs->fs_name) { fs->fs_name = savestr(name, 1); fs->fs_class = dp->d_class; fs->fs_type = dp->d_type; fs->fs_cred = dp->d_cred; fs->fs_list = NULL; fs->fs_last = NULL; } dbl = (struct db_list *)memget(sizeof(struct db_list)); if (!dbl) panic("rrsetadd: out of memory", NULL); dbl->db_next = NULL; dbl->db_dp = dp; if (fs->fs_last == NULL) fs->fs_list = dbl; else fs->fs_last->db_next = dbl; fs->fs_last = dbl; } static int ttlcheck(const char *name, struct db_list *dbl, int update) { int type = dbl->db_dp->d_type; int class = dbl->db_dp->d_class; struct hashbuf *htp = hashtab; const char *fname; struct namebuf *np; struct db_list *dbp = dbl; struct databuf *dp; u_int32_t ttl = 0; /* Make gcc happy. */ int first; np = nlookup(name, &htp, &fname, 0); if (np == NULL || fname != name || ns_wildcard(NAME(*np))) return (1); /* check that all the ttl's we have are the same, if not return 1 */ first = 1; for (dp = np->n_data; dp != NULL; dp = dp->d_next) { if (!match(dp, class, type)) continue; if (first) { /* we can't update zone data so return early */ if (dp->d_zone != DB_Z_CACHE) return (0); ttl = dp->d_ttl; first = 0; } else if (ttl != dp->d_ttl) return (1); } /* there are no records of this type in the cache */ if (first) return(1); /* * the ttls of all records we have in the cache are the same * if the ttls differ in the new set we don't want it. */ /* check that all the ttl's we have are the same, if not return 0 */ first = 1; while (dbp) { if (first) { ttl = dbp->db_dp->d_ttl; first = 0; } else if (ttl != dbp->db_dp->d_ttl) { return(0); } dbp = dbp->db_next; } /* update ttl if required */ if (update) { for (dp = np->n_data; dp != NULL; dp = dp->d_next) { if (!match(dp, class, type)) continue; if (dp->d_ttl > ttl) break; dp->d_ttl = ttl; fixttl(dp); } } return(1); } static int rrsetcmp(name, dbl) char *name; struct db_list *dbl; { int type = dbl->db_dp->d_type; int class = dbl->db_dp->d_class; struct hashbuf *htp = hashtab; const char *fname; struct namebuf *np; struct db_list *dbp = dbl; struct databuf *dp; int exists = 0; np = nlookup(name, &htp, &fname, 0); if (np == NULL || fname != name || ns_wildcard(NAME(*np))) { ns_debug(ns_log_default, 3, "rrsetcmp: name not in database"); return (-1); } /* check that all entries in dbl are in the cache */ while (dbp) { for (dp = np->n_data; dp != NULL; dp = dp->d_next) { if (match(dp, class, type)) exists++; if (!db_cmp(dp, dbp->db_dp) #ifdef NOADDITIONAL && ((dp->d_cred == dbp->db_dp->d_cred) || (dp->d_cred != DB_C_ADDITIONAL)) #endif ) break; } if (!dp) { ns_debug(ns_log_default, 3, "rrsetcmp: %srecord%s in database", exists ? "" : "no ", exists ? " not" : "s"); return (exists ? 1 : -1); } dbp = dbp->db_next; } /* Check that all cache entries are in the list. */ for (dp = np->n_data; dp != NULL; dp = dp->d_next) { if (!match(dp, class, type)) continue; #ifdef NCACHE if (dp->d_rcode) return (1); #endif dbp = dbl; while (dbp) { if (!db_cmp(dp, dbp->db_dp)) break; dbp = dbp->db_next; } if (!dbp) { ns_debug(ns_log_default, 3, "rrsetcmp: record not in rrset"); return (1); } } ns_debug(ns_log_default, 3, "rrsetcmp: rrsets matched"); return (0); } static void rrsetupdate(struct flush_set * flushset, int flags, struct sockaddr_in from) { struct flush_set *fs = flushset; struct db_list *dbp, *odbp; int n; while (fs->fs_name) { ns_debug(ns_log_default, 2, "rrsetupdate: %s", fs->fs_name[0] ? fs->fs_name : "."); if ((n = rrsetcmp(fs->fs_name, fs->fs_list)) && ttlcheck(fs->fs_name, fs->fs_list, 0)) { if (n > 0) flushrrset(fs, from); dbp = fs->fs_list; while (dbp) { n = db_update(fs->fs_name, dbp->db_dp, dbp->db_dp, NULL, flags, hashtab, from); ns_debug(ns_log_default, 3, "rrsetupdate: %s %d", fs->fs_name[0] ? fs->fs_name : ".", n); if (n != OK) db_freedata(dbp->db_dp); odbp = dbp; dbp = dbp->db_next; memput(odbp, sizeof *odbp); } } else { if (n == 0) (void)ttlcheck(fs->fs_name,fs->fs_list, 1); dbp = fs->fs_list; while (dbp) { db_freedata(dbp->db_dp); odbp = dbp; dbp = dbp->db_next; memput(odbp, sizeof *odbp); } } fs->fs_list = NULL; fs++; } } static void flushrrset(struct flush_set * fs, struct sockaddr_in from) { struct databuf *dp; int n; ns_debug(ns_log_default, 2, "flushrrset(%s, %s, %s, %d)", fs->fs_name[0]?fs->fs_name:".", p_type(fs->fs_type), p_class(fs->fs_class), fs->fs_cred); dp = savedata(fs->fs_class, fs->fs_type, 0, NULL, 0); dp->d_zone = DB_Z_CACHE; dp->d_cred = fs->fs_cred; dp->d_clev = 0; do { n = db_update(fs->fs_name, dp, NULL, NULL, DB_DELETE, hashtab, from); ns_debug(ns_log_default, 3, "flushrrset: %d", n); } while (n == OK); db_freedata(dp); } static void free_flushset(struct flush_set *flushset, int flushset_size) { struct flush_set *fs; for (fs = flushset; fs->fs_name != NULL; fs++) freestr(fs->fs_name); memput(flushset, flushset_size); } /* * This is best thought of as a "cache invalidate" function. * It is called whenever a piece of data is determined to have * become invalid either through a timeout or a validation * failure. It is better to have no information, than to * have partial information you pass off as complete. */ void delete_all(struct namebuf *np, int class, int type) { struct databuf *dp, *pdp; ns_debug(ns_log_default, 3, "delete_all(%#x:\"%s\" %s %s)", np, NAME(*np), p_class(class), p_type(type)); pdp = NULL; dp = np->n_data; while (dp != NULL) { if (dp->d_zone == DB_Z_CACHE && (dp->d_flags & DB_F_HINT) == 0 && match(dp, class, type)) { dp = rm_datum(dp, np, pdp, NULL); continue; } pdp = dp; dp = dp->d_next; } } /* delete_stale(np) * for all RRs associated with this name, check for staleness (& delete) * arguments: * np = pointer to namebuf to be cleaned. * returns: * void. * side effects: * delete_all() can be called, freeing memory and relinking chains. */ void delete_stale(np) struct namebuf *np; { struct databuf *dp; again: for (dp = np->n_data; dp != NULL; dp = dp->d_next) { if (dp->d_zone == DB_Z_CACHE && stale(dp)) { delete_all(np, dp->d_class, dp->d_type); goto again; } } } /* * Adjust answer message so that it fits in outlen. Set tc if required. * * If outlen = msglen, can be used to verify qdcount, ancount, nscount * and arcount. * * return new length */ int trunc_adjust(u_char *msg, int msglen, int outlen) { register HEADER *hp; u_int qdcount, ancount, nscount, arcount, dlen; u_char *cp = msg, *cp1, *eom_in, *eom_out; int n; eom_in = msg + msglen; eom_out = msg + outlen; hp = (HEADER *)msg; qdcount = ntohs(hp->qdcount); ancount = ntohs(hp->ancount); nscount = ntohs(hp->nscount); arcount = ntohs(hp->arcount); cp += HFIXEDSZ; while ((qdcount || ancount || nscount || arcount) && cp < eom_in && cp < eom_out) { cp1 = cp; /* use temporary in case we break */ n = dn_skipname(cp1, eom_in); if (n < 0) break; cp1 += n + 2 * INT16SZ; /* type, class */ if (!qdcount) { cp1 += INT32SZ; /* ttl */ if (cp1 + INT16SZ > eom_in) break; GETSHORT(dlen, cp1); cp1 += dlen; } if (cp1 > eom_in || cp1 > eom_out) break; cp = cp1; if (qdcount) qdcount--; else if (ancount) ancount--; else if (nscount) nscount--; else arcount--; } if (qdcount || ancount || nscount || arcount) { ns_debug(ns_log_default, 1, "trunc_adjust:%s %d %d %d %d %d, %d %d %d %d %d", hp->tc?" tc":"", msglen, ntohs(hp->qdcount), ntohs(hp->ancount), ntohs(hp->nscount), ntohs(hp->arcount), cp-msg, qdcount, ancount, nscount, arcount); hp->tc = 1; hp->qdcount = htons(ntohs(hp->qdcount) - qdcount); hp->ancount = htons(ntohs(hp->ancount) - ancount); hp->nscount = htons(ntohs(hp->nscount) - nscount); hp->arcount = htons(ntohs(hp->arcount) - arcount); } ENSURE(cp <= eom_out); return (cp - msg); } static void add_related_additional(char *name) { int i; if (num_related >= MAX_RELATED - 1) return; for (i = 0; i < num_related; i++) if (strcasecmp(name, related[i]) == 0) { freestr(name); return; } related[num_related++] = name; } static void free_related_additional() { int i; for (i = 0; i < num_related; i++) freestr(related[i]); num_related = 0; } static int related_additional(char *name) { int i; for (i = 0; i < num_related; i++) if (strcasecmp(name, related[i]) == 0) return (1); return (0); } static void freestr_maybe(char **tname) { if (tname == NULL || *tname == NULL) return; freestr(*tname); *tname = NULL; }