diff options
Diffstat (limited to 'contrib/bind/bin/named/ns_forw.c')
| -rw-r--r-- | contrib/bind/bin/named/ns_forw.c | 1331 |
1 files changed, 0 insertions, 1331 deletions
diff --git a/contrib/bind/bin/named/ns_forw.c b/contrib/bind/bin/named/ns_forw.c deleted file mode 100644 index c527a80..0000000 --- a/contrib/bind/bin/named/ns_forw.c +++ /dev/null @@ -1,1331 +0,0 @@ -#if !defined(lint) && !defined(SABER) -static const char sccsid[] = "@(#)ns_forw.c 4.32 (Berkeley) 3/3/91"; -static const char rcsid[] = "$Id: ns_forw.c,v 8.92.6.1 2003/06/02 09:56:34 marka Exp $"; -#endif /* not lint */ - -/* - * Copyright (c) 1986 - * 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) 1996-2000 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 <sys/types.h> -#include <sys/param.h> -#include <sys/socket.h> -#include <sys/un.h> - -#include <netinet/in.h> -#include <arpa/inet.h> -#include <arpa/nameser.h> - -#include <errno.h> -#include <resolv.h> -#include <stdio.h> -#include <stdlib.h> -#include <string.h> -#include <syslog.h> -#include <time.h> - -#include <isc/eventlib.h> -#include <isc/logging.h> -#include <isc/memcluster.h> - -#include <isc/dst.h> - -#include "port_after.h" - -#include "named.h" - -struct complaint { - u_long tag1, tag2; - time_t expire; - struct complaint *next; -}; - -static struct complaint *complaints = NULL; -static int retry_timer_set = 0; - -/* - * Forward the query to get the answer since its not in the database. - * Returns FW_OK if a request struct is allocated and the query sent. - * Returns FW_DUP if this is a duplicate of a pending request. - * Returns FW_NOSERVER if there were no addresses for the nameservers. - * Returns FW_SERVFAIL on memory allocation error or if asked to do something - * dangerous, such as fwd to ourselves or fwd to the host that asked us. - * - * (no action is taken on errors and qpp is not filled in.) - */ -int -ns_forw(struct databuf *nsp[], u_char *msg, int msglen, - struct sockaddr_in from, struct qstream *qsp, int dfd, - struct qinfo **qpp, const char *dname, int class, int type, - struct namebuf *np, int use_tcp, struct tsig_record *in_tsig) -{ - struct qinfo *qp; - char tmpdomain[MAXDNAME]; - struct sockaddr_in *nsa; - HEADER *hp; - u_int16_t id; - int sendto_errno = 0; - int n, has_tsig, oldqlen = 0; - u_char *oldqbuf = NULL; - u_char *smsg = NULL; - int smsglen, smsgsize = 0, siglen; - u_char sig[TSIG_SIG_SIZE]; - DST_KEY *key; - - ns_debug(ns_log_default, 3, "ns_forw()"); - - hp = (HEADER *) msg; - id = hp->id; - /* Look at them all */ - for (qp = nsqhead; qp != NULL; qp = qp->q_link) { - if (qp->q_id == id && - memcmp(&qp->q_from, &from, sizeof qp->q_from) == 0 && - ((qp->q_cmsglen == 0 && qp->q_msglen == msglen && - memcmp(qp->q_msg + 2, msg + 2, msglen - 2) == 0) || - (qp->q_cmsglen == msglen && - memcmp(qp->q_cmsg + 2, msg + 2, msglen - 2) == 0) - )) { - ns_debug(ns_log_default, 3, "forw: dropped DUP id=%d", - ntohs(id)); - nameserIncr(from.sin_addr, nssRcvdDupQ); - return (FW_DUP); - } - } - - qp = qnew(dname, class, type, 1); - getname(np, tmpdomain, sizeof tmpdomain); - qp->q_domain = savestr(tmpdomain, 1); - qp->q_from = from; /* nslookup wants to know this */ - if (NS_ZFWDTAB(qp->q_fzone)) - nsfwdadd(qp, NS_ZFWDTAB(qp->q_fzone)); - if (NS_ZOPTION_P(qp->q_fzone, OPTION_FORWARD_ONLY)) - n = 0; - else - n = nslookup(nsp, qp, dname, "ns_forw"); - if (n < 0) { - if (n == -1) - ns_debug(ns_log_default, 2, - "forw: nslookup reports danger"); - ns_freeqry(qp); - return (FW_SERVFAIL); - } - if (n == 0 && !NS_ZFWDTAB(qp->q_fzone)) { - ns_debug(ns_log_default, 2, "forw: no nameservers found"); - ns_freeqry(qp); - return (FW_NOSERVER); - } - qp->q_stream = qsp; - qp->q_curaddr = 0; - qp->q_dfd = dfd; - qp->q_id = id; - qp->q_expire = tt.tv_sec + RETRY_TIMEOUT*2; - if (in_tsig != NULL) - qp->q_tsig = new_tsig(in_tsig->key, in_tsig->sig, - in_tsig->siglen); - if (use_tcp) - qp->q_flags |= Q_USEVC; - hp->id = qp->q_nsid = htons(nsid_next()); - hp->ancount = htons(0); - hp->nscount = htons(0); - hp->arcount = htons(0); - if ((qp->q_msg = (u_char *)memget((unsigned)msglen)) == NULL) { - ns_notice(ns_log_default, "forw: memget: %s", - strerror(errno)); - ns_freeqry(qp); - return (FW_SERVFAIL); - } - qp->q_msgsize = msglen; - memcpy(qp->q_msg, msg, qp->q_msglen = msglen); - hp = (HEADER *) qp->q_msg; - hp->rd = (qp->q_addr[0].forwarder ? 1 : 0); - qp->q_addr[0].stime = tt; - - schedretry(qp, retrytime(qp)); - - nsa = Q_NEXTADDR(qp, 0); - ns_debug(ns_log_default, 1, - "forw: forw -> [%s].%d ds=%d nsid=%d id=%d %dms retry %dsec", - inet_ntoa(nsa->sin_addr), - ntohs(nsa->sin_port), ds, - ntohs(qp->q_nsid), ntohs(qp->q_id), - (qp->q_addr[0].nsdata != NULL) - ? qp->q_addr[0].nsdata->d_nstime - : -1, - (int)(qp->q_time - tt.tv_sec)); - -#ifdef DEBUG - if (debug >= 10) - res_pquery(&res, msg, msglen, log_get_stream(packet_channel)); -#endif - key = qp->q_keys[0]; - if (key == NULL) - key = qp->q_keys[0] = tsig_key_from_addr(nsa->sin_addr); - if (key != NULL || !qp->q_addr[0].noedns) { - smsgsize = qp->q_msglen + TSIG_BUF_SIZE + 11; - smsg = memget(smsgsize); - if (smsg == NULL) - ns_panic(ns_log_default, 1, "ns_forw: memget failed"); - smsglen = qp->q_msglen; - siglen = sizeof(sig); - memcpy(smsg, qp->q_msg, qp->q_msglen); - } - - if (!qp->q_addr[0].noedns) - smsglen += ns_add_opt(smsg, smsg + smsglen, smsgsize, 0, 0, - server_options->edns_udp_size, - 0, NULL, 0); - - if (key != NULL) { - n = ns_sign(smsg, &smsglen, smsgsize, NOERROR, key, NULL, 0, - sig, &siglen, 0); - if (n == 0) { - has_tsig = 1; - free_tsig(qp->q_nstsig); - qp->q_nstsig = new_tsig(key, sig, siglen); - } else { - has_tsig = 0; - free_tsig(qp->q_nstsig); - qp->q_nstsig = NULL; - INSIST(0); - } - } else { - has_tsig = 0; - free_tsig(qp->q_nstsig); - qp->q_nstsig = NULL; - } - - if (smsg != NULL) { - oldqbuf = qp->q_msg; - oldqlen = qp->q_msglen; - qp->q_msglen = smsglen; - qp->q_msg = smsg; - hp = (HEADER *) qp->q_msg; - } - - 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) { - sendto_errno = errno; - if (!haveComplained(ina_ulong(nsa->sin_addr), - (u_long)sendtoStr)) - ns_info(ns_log_default, "ns_forw: sendto(%s): %s", - sin_ntoa(*nsa), strerror(errno)); - nameserIncr(nsa->sin_addr, nssSendtoErr); - } - - if (smsgsize != 0) { - memput(smsg, smsgsize); - qp->q_msg = oldqbuf; - qp->q_msglen = oldqlen; - hp = (HEADER *) qp->q_msg; - } - - nameserIncr(from.sin_addr, nssRcvdFwdQ); - nameserIncr(nsa->sin_addr, nssSentFwdQ); - if (qpp) - *qpp = qp; - hp->rd = 1; - switch (sendto_errno) { - case ENETDOWN: - case ENETUNREACH: - case EHOSTDOWN: - case EHOSTUNREACH: - unsched(qp); - schedretry(qp, (time_t) 0); - } - return (0); -} - -/* haveComplained(tag1, tag2) - * check to see if we have complained about (tag1,tag2) recently - * returns: - * boolean: have we complained recently? - * side-effects: - * outdated complaint records removed from our static list - * author: - * Paul Vixie (DECWRL) April 1991 - */ -int -haveComplained(u_long tag1, u_long tag2) { - struct complaint *cur, *next, *prev; - int r = 0; - - for (cur = complaints, prev = NULL; - cur != NULL; - prev = cur, cur = next) { - next = cur->next; - if (tt.tv_sec > cur->expire) { - if (prev) - prev->next = next; - else - complaints = next; - memput(cur, sizeof *cur); - cur = prev; - } else if (tag1 == cur->tag1 && tag2 == cur->tag2) - r++; - } - if (!r) { - cur = (struct complaint *)memget(sizeof(struct complaint)); - if (cur) { - cur->tag1 = tag1; - cur->tag2 = tag2; - cur->expire = tt.tv_sec + INIT_REFRESH; /* "10:00" */ - cur->next = NULL; - if (prev) - prev->next = cur; - else - complaints = cur; - } - } - return (r); -} - -void -freeComplaints(void) { - struct complaint *cur, *next; - - for (cur = complaints; cur != NULL; cur = next) { - next = cur->next; - memput(cur, sizeof *cur); - } - complaints = NULL; -} - -/* void - * nslookupComplain(sysloginfo, queryname, complaint, dname, a_rr) - * Issue a complaint about a dangerous situation found by nslookup(). - * params: - * sysloginfo is a string identifying the complainant. - * queryname is the domain name associated with the problem. - * complaint is a string describing what is wrong. - * dname and a_rr are the problematic other name server. - */ -static void -nslookupComplain(const char *sysloginfo, const char *queryname, - const char *complaint, const char *dname, - const struct databuf *a_rr, const struct databuf *nsdp) -{ - char *a, *ns; - const char *a_type; - int print_a; - - ns_debug(ns_log_default, 2, "NS '%s' %s", dname, complaint); - if (sysloginfo && queryname && !haveComplained((u_long)queryname, - (u_long)complaint)) { - char nsbuf[20], abuf[20]; - - a = ns = (char *)NULL; - print_a = (a_rr->d_type == T_A); - a_type = p_type(a_rr->d_type); - if (a_rr->d_rcode) { - print_a = 0; - switch(a_rr->d_rcode) { - case NXDOMAIN: - a_type = "NXDOMAIN"; - break; - case NOERROR_NODATA: - a_type = "NODATA"; - break; - } - } - if (nsdp != NULL) { - if (nsdp->d_addr.s_addr != htonl(0)) { - strcpy(nsbuf, - inet_ntoa(nsdp->d_addr)); - ns = nsbuf; - } else { - ns = zones[nsdp->d_zone].z_origin; - } - } - if (a_rr->d_addr.s_addr != htonl(0)) { - strcpy(abuf, inet_ntoa(a_rr->d_addr)); - a = abuf; - } else { - a = zones[a_rr->d_zone].z_origin; - } - if (a != NULL || ns != NULL) - ns_info(ns_log_default, - "%s: query(%s) %s (%s:%s) learnt (%s=%s:NS=%s)", - sysloginfo, queryname, - complaint, dname, - print_a ? - inet_ntoa(ina_get(a_rr->d_data)) : "", - a_type, - a ? a : "<Not Available>", - ns ? ns : "<Not Available>" ); - else - ns_info(ns_log_default, "%s: query(%s) %s (%s:%s)", - sysloginfo, queryname, - complaint, dname, - print_a ? - inet_ntoa(ina_get(a_rr->d_data)) : ""); - } -} - -/* - * nslookup(nsp, qp, syslogdname, sysloginfo) - * Lookup the address for each nameserver in `nsp' and add it to - * the list saved in the qinfo structure pointed to by `qp'. - * Omits information about nameservers that we shouldn't ask. - * Detects the following dangerous operations: - * One of the A records for one of the nameservers in nsp - * refers to the address of one of our own interfaces; - * One of the A records refers to the nameserver port on - * the host that asked us this question. - * returns: the number of addresses added, or -1 if a dangerous operation - * is detected. - * side effects: - * logs if a dangerous situation is detected and - * (syslogdname && sysloginfo) - */ -int -nslookup(struct databuf *nsp[], struct qinfo *qp, - const char *syslogdname, const char *sysloginfo) -{ - struct namebuf *np; - struct databuf *dp, *nsdp; - struct qserv *qs; - int n; - u_int i; - struct hashbuf *tmphtp; - char *dname; - const char *fname; - int oldn, naddr, class, found_arr, potential_ns; - time_t curtime; - int found_auth6; - - ns_debug(ns_log_default, 3, "nslookup(nsp=%p, qp=%p, \"%s\", d=%d)", - nsp, qp, syslogdname, qp->q_distance); - - potential_ns = 0; - naddr = n = qp->q_naddr; - curtime = (u_long) tt.tv_sec; - while ((nsdp = *nsp++) != NULL && n < NSMAX) { - class = nsdp->d_class; - dname = (char *)nsdp->d_data; - ns_debug(ns_log_default, 3, - "nslookup: NS \"%s\" c=%d t=%d (flags 0x%lu)", - dname, class, nsdp->d_type, (u_long)nsdp->d_flags); - - /* don't put in servers we have tried */ - for (i = 0; i < qp->q_nusedns; i++) { - if (qp->q_usedns[i] == nsdp) { - ns_debug(ns_log_default, 2, - "skipping used NS w/name %s", - nsdp->d_data); - goto skipserver; - } - } - - found_arr = 0; - found_auth6 = 0; - tmphtp = ((nsdp->d_flags & DB_F_HINT) ?fcachetab :hashtab); - np = nlookup(dname, &tmphtp, &fname, 0); - if (np == NULL) { - ns_debug(ns_log_default, 3, "%s: not found %s %p", - dname, fname, np); - goto need_sysquery; - } - if (fname != dname) - goto need_sysquery; - oldn = n; - - /* look for name server addresses */ - (void)delete_stale(np); - for (dp = np->n_data; dp != NULL; dp = dp->d_next) { - struct in_addr nsa; - - if (dp->d_type == T_CNAME && dp->d_class == class) { - static const char *complaint = - "NS points to CNAME"; - if (dp->d_rcode) - continue; - nslookupComplain(sysloginfo, syslogdname, - complaint, dname, dp, nsdp); - goto skipserver; - } - if (dp->d_rcode == NXDOMAIN && dp->d_class == class) - goto skipserver; - if (dp->d_class == class && - (dp->d_type == T_AAAA || dp->d_type == ns_t_a6) && - (zones[dp->d_zone].z_type == z_master || - zones[dp->d_zone].z_type == z_slave)) { - found_auth6++; - continue; - } - if (dp->d_type != T_A || dp->d_class != class) - continue; - if (dp->d_rcode) { - /* Negative caching element. */ - goto skipserver; - } - if (ina_hlong(ina_get(dp->d_data)) == INADDR_ANY) { - static const char *complaint = - "Bogus (0.0.0.0) A RR"; - nslookupComplain(sysloginfo, syslogdname, - complaint, dname, dp, nsdp); - continue; - } -#ifdef INADDR_LOOPBACK - if (ina_hlong(ina_get(dp->d_data))==INADDR_LOOPBACK) { - static const char *complaint = - "Bogus LOOPBACK A RR"; - nslookupComplain(sysloginfo, syslogdname, - complaint, dname, dp, nsdp); - continue; - } -#endif -#ifdef INADDR_BROADCAST - if (ina_hlong(ina_get(dp->d_data))==INADDR_BROADCAST){ - static const char *complaint = - "Bogus BROADCAST A RR"; - nslookupComplain(sysloginfo, syslogdname, - complaint, dname, dp, nsdp); - continue; - } -#endif -#ifdef IN_MULTICAST - if (IN_MULTICAST(ina_hlong(ina_get(dp->d_data)))) { - static const char *complaint = - "Bogus MULTICAST A RR"; - nslookupComplain(sysloginfo, syslogdname, - complaint, dname, dp, nsdp); - continue; - } -#endif - /* - * Don't use records that may become invalid to - * reference later when we do the rtt computation. - * Never delete our safety-belt information! - */ - if ((dp->d_zone == DB_Z_CACHE) && - (dp->d_ttl < (u_int32_t)curtime) && - !(dp->d_flags & DB_F_HINT) ) - { - ns_debug(ns_log_default, 1, - "nslookup: stale '%s'", - NAME(*np)); - n = oldn; - found_arr = 0; - goto need_sysquery; - } - - found_arr++; - nsa = ina_get(dp->d_data); - /* don't put in duplicates */ - qs = qp->q_addr; - for (i = 0; i < (u_int)n; i++, qs++) - if (ina_equal(qs->ns_addr.sin_addr, nsa)) - goto skipaddr; - qs->ns_addr.sin_family = AF_INET; - qs->ns_addr.sin_port = ns_port; - qs->ns_addr.sin_addr = nsa; - qp->q_keys[n] = NULL; - qs->ns = nsdp; - qs->nsdata = dp; - qs->forwarder = 0; - qs->noedns = dp->d_noedns; - if (!qs->noedns) { - server_info si = find_server(nsa); - if (si && (si->flags & SERVER_INFO_EDNS) == 0) - qs->noedns = 1; - } - qs->lame = 0; - if ((nsdp->d_flags & DB_F_LAME) != 0) { - time_t when; - when = db_lame_find(qp->q_domain, nsdp); - if (when != 0 && when > tt.tv_sec) - qs->lame = 1; - } - qs->nretry = 0; - /* - * If this A RR has no RTT, initialize its RTT to a - * small random value. - */ - if (dp->d_nstime == 0) - dp->d_nstime = 1 + - (int)(25.0*rand()/(RAND_MAX + 1.0)); - /* - * if we are being asked to fwd a query whose - * nameserver list includes our own name/address(es), - * then we have detected a lame delegation and rather - * than melt down the network and hose down the other - * servers (who will hose us in return), we'll return - * -1 here which will cause SERVFAIL to be sent to - * the client's resolver which will hopefully then - * shut up. - * - * (originally done in nsContainsUs by vix@dec mar92; - * moved into nslookup by apb@und jan1993) - * - * try to limp along instead of denying service - * gdonl mar96 - */ - if (aIsUs(nsa)) { - static const char *complaint = - "contains our address"; - nslookupComplain(sysloginfo, syslogdname, - complaint, dname, dp, nsdp); - continue; - } - /* - * If we want to forward to a host that asked us - * this question then either we or they are sick - * (unless they asked from some port other than - * their nameserver port). (apb@und jan1993) - * - * try to limp along instead of denying service - * gdonl mar96 - */ - if (memcmp(&qp->q_from, &qs->ns_addr, - sizeof(qp->q_from)) == 0) - { - static const char *complaint = "forwarding loop"; - nslookupComplain(sysloginfo, syslogdname, - complaint, dname, dp, nsdp); - continue; - } -#ifdef BOGUSNS - /* - * Don't forward queries to bogus servers. Note - * that this is unlike the previous tests, which - * are fatal to the query. Here we just skip the - * server, which is only fatal if it's the last - * server. Note also that we antialias here -- all - * A RR's of a server are considered the same server, - * and if any of them is bogus we skip the whole - * server. Those of you using multiple A RR's to - * load-balance your servers will (rightfully) lose - * here. But (unfortunately) only if they are bogus. - */ - if (ip_match_address(bogus_nameservers, nsa) > 0) - goto skipserver; -#endif - if (server_options->blackhole_acl != NULL && - ip_match_address(server_options->blackhole_acl, - nsa) == 1) - continue; - - n++; - if (n >= NSMAX) - break; - skipaddr: - (void)NULL; - } - ns_debug(ns_log_default, 8, "nslookup: %d ns addrs", n); - need_sysquery: - if (found_arr == 0 && found_auth6 == 0) { - potential_ns++; - if (qp->q_distance < NS_MAX_DISTANCE) - (void) sysquery(dname, class, T_A, NULL, NULL, - 0, ns_port, QUERY, - qp->q_distance + 1); - } - skipserver: - (void)NULL; - } - ns_debug(ns_log_default, 3, "nslookup: %d ns addrs total", n); - qp->q_naddr = n; - if (n == 0 && potential_ns == 0 && !NS_ZFWDTAB(qp->q_fzone)) { - static const char *complaint = "No possible A RRs"; - if (sysloginfo && syslogdname && - !haveComplained((u_long)syslogdname, (u_long)complaint)) - { - ns_info(ns_log_default, "%s: query(%s) %s", - sysloginfo, syslogdname, complaint); - } - return (-1); - } - /* Update the refcounts before the sort. */ - for (i = naddr; i < (u_int)n; i++) { - DRCNTINC(qp->q_addr[i].nsdata); - DRCNTINC(qp->q_addr[i].ns); - } - /* Just sort the NS RR's we added, since the forwarders may - * be ahead of us (naddr > 0) - */ - if (n > naddr) { - qsort((char *)(qp->q_addr+naddr), n-naddr, sizeof(struct qserv), - (int (*)(const void *, const void *))qcomp); - } - return (n - naddr); -} - -/* - * qcomp - compare two NS addresses, and return a negative, zero, or - * positive value depending on whether the first NS address is - * "better than", "equally good as", or "inferior to" the second - * NS address. - * - * How "goodness" is defined (for the purposes of this routine): - * - If the estimated round trip times differ by an amount deemed significant - * then the one with the smaller estimate is preferred; else - * - If we can determine which one is topologically closer then the - * closer one is preferred; else - * - The one with the smaller estimated round trip time is preferred - * (zero is returned if the two estimates are identical). - * - * How "topological closeness" is defined (for the purposes of this routine): - * Ideally, named could consult some magic map of the Internet and - * determine the length of the path to an arbitrary destination. Sadly, - * no such magic map exists. However, named does have a little bit of - * topological information in the form of the sortlist (which includes - * the directly connected subnet(s), the directly connected net(s), and - * any additional nets that the administrator has added using the "sortlist" - * directive in the bootfile. Thus, if only one of the addresses matches - * something in the sortlist then it is considered to be topologically - * closer. If both match, but match different entries in the sortlist, - * then the one that matches the entry closer to the beginning of the - * sorlist is considered to be topologically closer. In all other cases, - * topological closeness is ignored because it's either indeterminate or - * equal. - * - * How times are compared: - * Both times are rounded to the closest multiple of the NOISE constant - * defined below and then compared. If the rounded values are equal - * then the difference in the times is deemed insignificant. Rounding - * is used instead of merely taking the absolute value of the difference - * because doing the latter would make the ordering defined by this - * routine be incomplete in the mathematical sense (e.g. A > B and - * B > C would not imply A > C). The mathematics are important in - * practice to avoid core dumps in qsort(). - * - * XXX: this doesn't solve the European root nameserver problem very well. - * XXX: we should detect and mark as inferior nameservers that give bogus - * answers - * - * (this was originally vixie's stuff but almquist fixed fatal bugs in it - * and wrote the above documentation) - */ - -/* - * RTT delta deemed to be significant, in milliseconds. With the current - * definition of RTTROUND it must be a power of 2. - */ -#define NOISE 64 - -#define RTTROUND(rtt) (((rtt) + (NOISE >> 1)) & ~(NOISE - 1)) - -int -qcomp(struct qserv *qs1, struct qserv *qs2) { - u_int rtt1, rtt2, rttr1, rttr2; - - /* sort lame servers to last */ - if (qs1->lame != qs2->lame) - return (qs1->lame - qs2->lame); - - /* sort by rtt */ - if (qs1->nsdata == NULL) { - rtt1 = 0; - rttr1 = 0; - } else { - rtt1 = qs1->nsdata->d_nstime; - rttr1 = RTTROUND(rtt1); - } - if (qs2->nsdata == NULL) { - rtt2 = 0; - rttr2 = 0; - } else { - rtt2 = qs2->nsdata->d_nstime; - rttr2 = RTTROUND(rtt2); - } - -#ifdef DEBUG - if (debug >= 10) { - char t[sizeof "255.255.255.255"]; - - strcpy(t, inet_ntoa(qs1->ns_addr.sin_addr)); - ns_debug(ns_log_default, 10, - "qcomp(%s, %s) %u (%u) - %u (%u) = %u", - t, inet_ntoa(qs2->ns_addr.sin_addr), - rtt1, rttr1, rtt2, rttr2, rtt1 - rtt2); - } -#endif - if (rttr1 == rttr2) { - int pos1, pos2, pdiff; - - pos1 = distance_of_address(server_options->topology, - qs1->ns_addr.sin_addr); - pos2 = distance_of_address(server_options->topology, - qs2->ns_addr.sin_addr); - pdiff = pos1 - pos2; - ns_debug(ns_log_default, 10, "\tpos1=%d, pos2=%d", pos1, pos2); - if (pdiff != 0) - return (pdiff); - } - return (rtt1 - rtt2); -} -#undef RTTROUND - -/* - * Arrange that forwarded query (qp) is retried after t seconds. - * Query list will be sorted after z_time is updated. - */ -void -schedretry(struct qinfo *qp, time_t t) { - struct qinfo *qp1, *qp2; - - ns_debug(ns_log_default, 4, "schedretry(%p, %ld sec)", qp, (long)t); - if (qp->q_time) - ns_debug(ns_log_default, 4, - "WARNING: schedretry(%#lx, %ld) q_time already %ld", - (u_long)qp, (long)t, (long)qp->q_time); - gettime(&tt); - t += (u_long) tt.tv_sec; - qp->q_time = t; - - if ((qp1 = retryqp) == NULL) { - retryqp = qp; - qp->q_next = NULL; - goto done; - } - if (t < qp1->q_time) { - qp->q_next = qp1; - retryqp = qp; - goto done; - } - while ((qp2 = qp1->q_next) != NULL && qp2->q_time < t) - qp1 = qp2; - qp1->q_next = qp; - qp->q_next = qp2; - done: - reset_retrytimer(); -} - -/* - * Unsched is called to remove a forwarded query entry. - */ -void -unsched(struct qinfo *qp) { - struct qinfo *np; - - ns_debug(ns_log_default, 3, "unsched(%#lx, %d)", - (u_long)qp, ntohs(qp->q_id)); - if (retryqp == qp) { - retryqp = qp->q_next; - } else { - for (np = retryqp; np->q_next != NULL; np = np->q_next) { - if (np->q_next != qp) - continue; - np->q_next = qp->q_next; /* dequeue */ - break; - } - } - qp->q_next = NULL; /* sanity check */ - qp->q_time = 0; - reset_retrytimer(); -} - -void -reset_retrytimer() { - static evTimerID id; - - if (retry_timer_set) { - (void) evClearTimer(ev, id); - retry_timer_set = 0; - } - - if (retryqp) { - evSetTimer(ev, retrytimer, NULL, - evConsTime(retryqp->q_time, 0), - evConsTime(0, 0), &id); - retry_timer_set = 1; - } else - memset(&id, 0, sizeof id); -} - -void -retrytimer(evContext ctx, void *uap, struct timespec due, - struct timespec ival) { - - UNUSED(ctx); - UNUSED(uap); - UNUSED(due); - UNUSED(ival); - - retry_timer_set = 0; - retry(retryqp, 0); -} - -/* - * Retry is called to retransmit query 'qp'. - */ -void -retry(struct qinfo *qp, int samehost) { - int n, has_tsig, oldqlen = 0; - HEADER *hp; - struct sockaddr_in *nsa; - int sendto_errno = 0; - u_char *oldqbuf = NULL; - u_char *smsg = NULL; - int smsglen, smsgsize = 0, siglen; - u_char sig[TSIG_SIG_SIZE]; - DST_KEY *key; - - ns_debug(ns_log_default, 3, "retry(%#lx) id=%d", (u_long)qp, - ntohs(qp->q_id)); - - if (qp->q_msg == NULL) { - qremove(qp); - return; - } - - if (qp->q_expire < tt.tv_sec) { - ns_debug(ns_log_default, 1, - "retry(%#lx): expired @ %lu (%d secs before now (%lu))", - (u_long)qp, (u_long)qp->q_expire, - (int)(tt.tv_sec - qp->q_expire), - (u_long)tt.tv_sec); - goto fail; - } - - /* Try next address. */ - n = qp->q_curaddr; - if (samehost) { - qp->q_addr[n].nretry++; - if (qp->q_addr[n].nretry < MAXRETRY) - goto found; - qp->q_addr[n].nretry--; - } - - if (qp->q_naddr > 0) { - qp->q_addr[n].noedns = 1; - ++qp->q_addr[n].nretry; - /* - * Look for a non-lame server. - */ - do { - if (++n >= (int)qp->q_naddr) - n = 0; - if ((qp->q_flags & Q_ZSERIAL) != 0 && - qp->q_addr[n].serial != 0) - continue; - if (qp->q_addr[n].lame) - continue; - if (qp->q_addr[n].nretry < MAXRETRY) - goto found; - } while (n != qp->q_curaddr); - /* - * Look for any server including lame servers. - */ - do { - if (++n >= (int)qp->q_naddr) - n = 0; - if ((qp->q_flags & Q_ZSERIAL) != 0 && - qp->q_addr[n].serial != 0) - continue; - if (qp->q_addr[n].nretry < MAXRETRY) - goto found; - } while (n != qp->q_curaddr); - if ((qp->q_flags & Q_ZSERIAL) != 0) { - qremove(qp); - return; - } - } - fail: - /* - * Give up. Can't reach destination. - */ - hp = (HEADER *)(qp->q_cmsg ? qp->q_cmsg : qp->q_msg); - if ((qp->q_flags & Q_PRIMING) != 0) { - /* Can't give up priming */ - if (qp->q_expire < tt.tv_sec) { - /* - * The query has expired. Reset it and retry from - * the beginning. - */ - hp->rcode = NOERROR; - hp->qr = hp->aa = 0; - for (n = 0; n < (int)qp->q_naddr; n++) - qp->q_addr[n].nretry = 0; - n = 0; - qp->q_expire = tt.tv_sec + RETRY_TIMEOUT*2; - goto found; - } - /* - * The query hasn't expired yet; it probably ran out - * of servers or forwarders. Wait up to 60 seconds - * past the expire time. - */ - unsched(qp); - schedretry(qp, (time_t)(qp->q_expire - tt.tv_sec + 60)); - return; - } - ns_debug(ns_log_default, 5, "give up"); - if ((qp->q_flags & Q_SYSTEM) == 0) { - n = (qp->q_cmsg ? qp->q_cmsglen : qp->q_msglen); - hp->id = qp->q_id; - hp->qr = 1; - hp->ra = (NS_OPTION_P(OPTION_NORECURSE) == 0); - hp->rd = 1; - hp->rcode = SERVFAIL; -#ifdef DEBUG - if (debug >= 10) - res_pquery(&res, qp->q_msg, n, - log_get_stream(packet_channel)); -#endif - if (send_msg((u_char *)hp, n, qp)) { - ns_debug(ns_log_default, 1, - "gave up retry(%#lx) nsid=%d id=%d", - (u_long)qp, - ntohs(qp->q_nsid), ntohs(qp->q_id)); - } - if (NS_OPTION_P(OPTION_HOSTSTATS)) - nameserIncr(qp->q_from.sin_addr, nssSentFail); - } - qremove(qp); - return; - - found: - if (qp->q_addr[n].nretry == 0) - qp->q_addr[n].stime = tt; - qp->q_curaddr = n; - hp = (HEADER *)qp->q_msg; - hp->rd = (qp->q_addr[n].forwarder ? 1 : 0); - nsa = Q_NEXTADDR(qp, n); - ns_debug(ns_log_default, 1, - "%s(addr=%d n=%d) -> [%s].%d ds=%d nsid=%d id=%d %dms", - (qp->q_addr[n].forwarder ? "reforw" : "resend"), - n, qp->q_addr[n].nretry, - inet_ntoa(nsa->sin_addr), - ntohs(nsa->sin_port), ds, - ntohs(qp->q_nsid), ntohs(qp->q_id), - (qp->q_addr[n].nsdata != 0) - ? qp->q_addr[n].nsdata->d_nstime - : (-1)); -#ifdef DEBUG - if (debug >= 10) - res_pquery(&res, qp->q_msg, qp->q_msglen, - log_get_stream(packet_channel)); -#endif - key = qp->q_keys[n]; - if (key == NULL) - key = qp->q_keys[n] = tsig_key_from_addr(nsa->sin_addr); - if (key != NULL || !qp->q_addr[n].noedns) { - smsgsize = qp->q_msglen + TSIG_BUF_SIZE + 11; - smsg = memget(smsgsize); - smsglen = qp->q_msglen; - siglen = sizeof(sig); - memcpy(smsg, qp->q_msg, qp->q_msglen); - } - - if (!qp->q_addr[n].noedns) - smsglen += ns_add_opt(smsg, smsg + smsglen, smsgsize, 0, 0, - server_options->edns_udp_size, - 0, NULL, 0); - - if (key != NULL) { - n = ns_sign(smsg, &smsglen, smsgsize, NOERROR, key, NULL, 0, - sig, &siglen, 0); - if (n == 0) { - has_tsig = 1; - free_tsig(qp->q_nstsig); - qp->q_nstsig = new_tsig(key, sig, siglen); - } else { - has_tsig = 0; - free_tsig(qp->q_nstsig); - qp->q_nstsig = NULL; - INSIST(0); - } - } else { - has_tsig = 0; - free_tsig(qp->q_nstsig); - qp->q_nstsig = NULL; - } - - if (smsg != NULL) { - oldqbuf = qp->q_msg; - oldqlen = qp->q_msglen; - qp->q_msglen = smsglen; - qp->q_msg = smsg; - } - - if (qp->q_flags & Q_USEVC) { - if (tcp_send(qp) != NOERROR) - ns_debug(ns_log_default, 3, - "error resending tcp msg: %s", - strerror(errno)); - } else if (sendto(ds, (char*)qp->q_msg, qp->q_msglen, 0, - (struct sockaddr *)nsa, - sizeof(struct sockaddr_in)) < 0) - { - sendto_errno = errno; - ns_debug(ns_log_default, 3, "error resending msg: %s", - strerror(errno)); - } - if (smsgsize != 0) { - memput(smsg, smsgsize); - qp->q_msg = oldqbuf; - qp->q_msglen = oldqlen; - } - hp->rd = 1; /* leave set to 1 for dup detection */ - nameserIncr(nsa->sin_addr, nssSentDupQ); - unsched(qp); - switch (sendto_errno) { - case ENETDOWN: - case ENETUNREACH: - case EHOSTDOWN: - case EHOSTUNREACH: - schedretry(qp, (time_t) 0); - return; - } - schedretry(qp, retrytime(qp)); -} - -/* - * Compute retry time for the next server for a query. - * Use a minimum time of RETRYBASE (4 sec.) or twice the estimated - * service time; * back off exponentially on retries, but place a 45-sec. - * ceiling on retry times for now. (This is because we don't hold a reference - * on servers or their addresses, and we have to finish before they time out.) - */ -time_t -retrytime(struct qinfo *qp) { - time_t t, u, v; - struct qserv *ns = &qp->q_addr[qp->q_curaddr]; - - if (ns->nsdata != NULL) - t = (time_t) MAX(RETRYBASE, 2 * ns->nsdata->d_nstime / 1000); - else - t = (time_t) RETRYBASE; - u = t << ns->nretry; - v = MIN(u, RETRY_TIMEOUT); /* max. retry timeout for now */ - ns_debug(ns_log_default, 3, - "retrytime: nstime%ldms t%ld nretry%ld u%ld : v%ld", - ns->nsdata ? (long)(ns->nsdata->d_nstime / 1000) : (long)-1, - (long)t, (long)ns->nretry, (long)u, (long)v); - return (v); -} - -void -qflush() { - while (nsqhead) - qremove(nsqhead); - nsqhead = NULL; - priming = 0; -} - -void -qremove(struct qinfo *qp) { - ns_debug(ns_log_default, 3, "qremove(%#lx)", (u_long)qp); - - if ((qp->q_flags & Q_ZSERIAL) != 0) - qserial_answer(qp); - unsched(qp); - ns_freeqry(qp); -} - -struct qinfo * -qfindid(u_int16_t id) { - struct qinfo *qp; - - for (qp = nsqhead; qp != NULL; qp = qp->q_link) - if (qp->q_nsid == id) - break; - ns_debug(ns_log_default, 3, "qfindid(%d) -> %#lx", ntohs(id), - (u_long)qp); - return (qp); -} - -struct qinfo * -qnew(const char *name, int class, int type, int forward) { - struct qinfo *qp; - const char *s; - int escape = 0; - - qp = (struct qinfo *)memget(sizeof *qp); - if (qp == NULL) - ns_panic(ns_log_default, 1, "qnew: memget failed"); - memset(qp, 0, sizeof *qp); - ns_debug(ns_log_default, 5, "qnew(%#lx)", (u_long)qp); -#ifdef BIND_NOTIFY - qp->q_notifyzone = DB_Z_CACHE; -#endif - qp->q_link = nsqhead; - nsqhead = qp; - qp->q_name = savestr(name, 1); - qp->q_class = (u_int16_t)class; - qp->q_type = (u_int16_t)type; - qp->q_flags = 0; - s = name; - qp->q_fzone = NULL; - for (;forward;) { /* find forwarding zone, if any */ - if ((qp->q_fzone = find_zone(s, class)) != NULL && - (qp->q_fzone->z_flags & Z_FORWARD_SET) != 0) - break; - qp->q_fzone = NULL; - if (*s == '\0') - break; - while (*s != '\0' && (escape || *s != '.')) { - escape = escape ? 0 : (*s == '\\'); - s++; - } - if (*s != '\0') - s++; - } - return (qp); -} - -void -ns_freeqns(struct qinfo *qp) { - unsigned int i; - - for (i = 0 ; i < qp->q_naddr ; i++) { - if (qp->q_addr[i].ns != NULL) - db_detach(&qp->q_addr[i].ns); - if (qp->q_addr[i].nsdata != NULL) - db_detach(&qp->q_addr[i].nsdata); - } -} - -void -ns_freeqry(struct qinfo *qp) { - struct qinfo *np; - - ns_debug(ns_log_default, 3, "ns_freeqry(%#lx)", (u_long)qp); - if (qp->q_next) - ns_debug(ns_log_default, 1, - "WARNING: ns_freeqry of linked ptr %#lx", (u_long)qp); - if (qp->q_msg != NULL) - memput(qp->q_msg, qp->q_msgsize); - if (qp->q_cmsg != NULL) - memput(qp->q_cmsg, qp->q_cmsgsize); - if (qp->q_domain != NULL) - qp->q_domain = freestr(qp->q_domain); - if (qp->q_name != NULL) - qp->q_name = freestr(qp->q_name); - if (qp->q_tsig != NULL) - memput(qp->q_tsig, sizeof(struct tsig_record)); - if (qp->q_nstsig != NULL) - memput(qp->q_nstsig, sizeof(struct tsig_record)); - ns_freeqns(qp); - if (nsqhead == qp) - nsqhead = qp->q_link; - else { - for(np = nsqhead; - np->q_link != NULL; - np = np->q_link) { - if (np->q_link != qp) - continue; - np->q_link = qp->q_link; /* dequeue */ - break; - } - } - memput(qp, sizeof *qp); -} - -void -nsfwdadd(struct qinfo *qp, struct fwdinfo *fwd) { - int i, n; - struct qserv *qs; - - n = qp->q_naddr; - while (fwd != NULL && n < NSMAX) { - qs = qp->q_addr; - for (i = 0; i < n; i++, qs++) - if (ina_equal(qs->ns_addr.sin_addr, - fwd->fwddata->fwdaddr.sin_addr)) - goto nextfwd; - qs->ns_addr = fwd->fwddata->fwdaddr; - qs->ns = fwd->fwddata->ns; - qs->nsdata = fwd->fwddata->nsdata; - qs->forwarder = 1; - qs->noedns = fwd->fwddata->nsdata->d_noedns; - if (!qs->noedns) { - server_info si = find_server(qs->ns_addr.sin_addr); - if (si && (si->flags & SERVER_INFO_EDNS) == 0) - qs->noedns = 1; - } - qs->nretry = 0; - n++; - nextfwd: - fwd = fwd->next; - } - - /* Update the refcounts before the sort. */ - for (i = qp->q_naddr; i < n; i++) { - DRCNTINC(qp->q_addr[i].nsdata); - DRCNTINC(qp->q_addr[i].ns); - } - qp->q_naddr = n; - if (n > 1) { - qsort((char *)qp->q_addr, n, sizeof(struct qserv), - (int (*)(const void *, const void *))qcomp); - } -} |
