diff options
Diffstat (limited to 'contrib/bind/named/ns_forw.c')
| -rw-r--r-- | contrib/bind/named/ns_forw.c | 1096 |
1 files changed, 0 insertions, 1096 deletions
diff --git a/contrib/bind/named/ns_forw.c b/contrib/bind/named/ns_forw.c deleted file mode 100644 index 06d428b7df16..000000000000 --- a/contrib/bind/named/ns_forw.c +++ /dev/null @@ -1,1096 +0,0 @@ -#if !defined(lint) && !defined(SABER) -static char sccsid[] = "@(#)ns_forw.c 4.32 (Berkeley) 3/3/91"; -static char rcsid[] = "$Id: ns_forw.c,v 8.20 1997/06/01 20:34:34 vixie Exp $"; -#endif /* not lint */ - -/* - * ++Copyright++ 1986 - * - - * 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. - * - - * --Copyright-- - */ - -#include <sys/types.h> -#include <sys/param.h> -#include <sys/socket.h> -#include <netinet/in.h> -#include <arpa/inet.h> -#include <arpa/nameser.h> - -#include <syslog.h> -#include <resolv.h> -#include <stdio.h> -#include <errno.h> - -#include "named.h" - -/* - * 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 malloc 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(nsp, msg, msglen, fp, qsp, dfd, qpp, dname, class, type, np) - struct databuf *nsp[]; - u_char *msg; - int msglen; - struct sockaddr_in *fp; - struct qstream *qsp; - int dfd; - struct qinfo **qpp; - char *dname; - int class, type; - struct namebuf *np; -{ - register struct qinfo *qp; - char tmpdomain[MAXDNAME]; - struct sockaddr_in *nsa; - HEADER *hp; - u_int16_t id; - int n; - - dprintf(3, (ddt, "ns_forw()\n")); - - hp = (HEADER *) msg; - id = hp->id; - /* Look at them all */ - for (qp = nsqhead; qp != QINFO_NULL; qp = qp->q_link) { - if (qp->q_id == id && - bcmp((char *)&qp->q_from, fp, sizeof(qp->q_from)) == 0 && - ((qp->q_cmsglen == 0 && qp->q_msglen == msglen && - bcmp((char *)qp->q_msg+2, msg+2, msglen-2) == 0) || - (qp->q_cmsglen == msglen && - bcmp((char *)qp->q_cmsg+2, msg+2, msglen-2) == 0))) { - dprintf(3, (ddt, - "forw: dropped DUP id=%d\n", ntohs(id))); -#ifdef XSTATS - nameserIncr(fp->sin_addr, nssRcvdDupQ); -#endif - return (FW_DUP); - } - } - - qp = qnew(dname, class, type); - getname(np, tmpdomain, sizeof tmpdomain); - qp->q_domain = strdup(tmpdomain); - if (!qp->q_domain) - panic(ENOMEM, "ns_forw: strdup failed"); - qp->q_from = *fp; /* nslookup wants to know this */ - n = nslookup(nsp, qp, dname, "ns_forw"); - if (n < 0) { - dprintf(2, (ddt, "forw: nslookup reports danger\n")); - qfree(qp); - return (FW_SERVFAIL); - } - if (n == 0 && !fwdtab) { - dprintf(2, (ddt, "forw: no nameservers found\n")); - qfree(qp); - return (FW_NOSERVER); - } - qp->q_stream = qsp; - qp->q_curaddr = 0; - qp->q_fwd = fwdtab; - qp->q_dfd = dfd; - qp->q_id = id; - qp->q_expire = tt.tv_sec + RETRY_TIMEOUT*2; - 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 *)malloc((unsigned)msglen)) == NULL) { - syslog(LOG_NOTICE, "forw: malloc: %m"); - qfree(qp); - return (FW_SERVFAIL); - } - bcopy(msg, qp->q_msg, qp->q_msglen = msglen); - if (!qp->q_fwd) { - hp->rd = 0; - qp->q_addr[0].stime = tt; - } - -#ifdef SLAVE_FORWARD - if (forward_only) - schedretry(qp, (time_t)slave_retry); - else -#endif /* SLAVE_FORWARD */ - schedretry(qp, qp->q_fwd ?(2*RETRYBASE) :retrytime(qp)); - - nsa = Q_NEXTADDR(qp, 0); - dprintf(1, (ddt, - "forw: forw -> [%s].%d ds=%d nsid=%d id=%d %dms retry %dsec\n", - 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) - fp_nquery(msg, msglen, ddt); -#endif - if (sendto(ds, (char *)msg, msglen, 0, (struct sockaddr *)nsa, - sizeof(struct sockaddr_in)) < 0) { - if (!haveComplained((char*)nsa->sin_addr.s_addr, sendtoStr)) - syslog(LOG_INFO, "ns_forw: sendto([%s].%d): %m", - inet_ntoa(nsa->sin_addr), ntohs(nsa->sin_port)); - nameserIncr(nsa->sin_addr, nssSendtoErr); - } -#ifdef XSTATS - nameserIncr(fp->sin_addr, nssRcvdFwdQ); -#endif - nameserIncr(nsa->sin_addr, nssSentFwdQ); - if (qpp) - *qpp = qp; - hp->rd = 1; - return (0); -} - -/* struct qdatagram * - * aIsUs(addr) - * scan the datagramq (our list of interface addresses) for "addr" - * returns: - * pointer to qdatagram entry or NULL if no match is found - * notes: - * INADDR_ANY ([0.0.0.0]) is on the datagramq, so it's considered "us" - * author: - * Paul Vixie (DECWRL) April 1991 - */ -struct qdatagram * -aIsUs(addr) - struct in_addr addr; -{ - struct qdatagram *dqp; - - for (dqp = datagramq; dqp != QDATAGRAM_NULL; dqp = dqp->dq_next) { - if (addr.s_addr == dqp->dq_addr.s_addr) { - return dqp; - } - } - return NULL; -} - -/* haveComplained(tag1, tag2) - * check to see if we have complained about (tag1,tag2) recently - * (note that these are declared as pointers but are never deref'd) - * returns: - * boolean: have we complained recently? - * side-effects: - * outdated complaint records removed from our static list - * author: - * Paul Vixie (DECWRL) April 1991 - */ -int -haveComplained(tag1, tag2) - const char *tag1, *tag2; -{ - struct complaint { - const char *tag1, *tag2; - time_t expire; - struct complaint *next; - }; - static struct complaint *List = NULL; - struct complaint *cur, *next, *prev; - int r = 0; - - for (cur = List, prev = NULL; cur; prev = cur, cur = next) { - next = cur->next; - if (tt.tv_sec > cur->expire) { - if (prev) - prev->next = next; - else - List = next; - free((char*) cur); - cur = prev; - } else if ((tag1 == cur->tag1) && (tag2 == cur->tag2)) { - r++; - } - } - if (!r) { - cur = (struct complaint *)malloc(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 - List = cur; - } - } - return (r); -} - -/* 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(sysloginfo, queryname, complaint, dname, a_rr, nsdp) - const char *sysloginfo, *queryname, *complaint, *dname; - const struct databuf *a_rr, *nsdp; -{ -#ifdef STATS - char nsbuf[20]; - char abuf[20]; -#endif - char *a, *ns; - const char *a_type; - int print_a; - - dprintf(2, (ddt, "NS '%s' %s\n", dname, complaint)); - if (sysloginfo && queryname && !haveComplained(queryname, complaint)) - { - char buf[999]; - - a = ns = (char *)NULL; - print_a = (a_rr->d_type == T_A); - a_type = p_type(a_rr->d_type); -#ifdef NCACHE - 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; - } - } -#endif -#ifdef STATS - if (nsdp) { - if (nsdp->d_ns) { - strcpy(nsbuf, inet_ntoa(nsdp->d_ns->addr)); - ns = nsbuf; - } else { - ns = zones[nsdp->d_zone].z_origin; - } - } - if (a_rr->d_ns) { - strcpy(abuf, inet_ntoa(a_rr->d_ns->addr)); - a = abuf; - } else { - a = zones[a_rr->d_zone].z_origin; - } -#endif - /* syslog only takes 5 params */ - if ( a != NULL || ns != NULL) - sprintf(buf, "%s: query(%s) %s (%s:%s) learnt (%s=%s:NS=%s)", - sysloginfo, queryname, - complaint, dname, - print_a ? - inet_ntoa(data_inaddr(a_rr->d_data)) : "", - a_type, - a ? a : "<Not Available>", - ns ? ns : "<Not Available>" ); - else - sprintf(buf, "%s: query(%s) %s (%s:%s)", - sysloginfo, queryname, - complaint, dname, - print_a ? - inet_ntoa(data_inaddr(a_rr->d_data)) : ""); - syslog(LOG_INFO, "%s", buf); - } -} - -/* - * 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: - * if a dangerous situation is detected and (syslogdname && sysloginfo), - * calls syslog. - */ -int -nslookup(nsp, qp, syslogdname, sysloginfo) - struct databuf *nsp[]; - register struct qinfo *qp; - const char *syslogdname; - const char *sysloginfo; -{ - register struct namebuf *np; - register struct databuf *dp, *nsdp; - register struct qserv *qs; - register int n; - register u_int i; - struct hashbuf *tmphtp; - char *dname; - const char *fname; - int oldn, naddr, class, found_arr, potential_ns; - time_t curtime; - - dprintf(3, (ddt, "nslookup(nsp=0x%lx, qp=0x%lx, \"%s\")\n", - (u_long)nsp, (u_long)qp, syslogdname)); - - potential_ns = 0; - naddr = n = qp->q_naddr; - curtime = (u_long) tt.tv_sec; - while ((nsdp = *nsp++) != NULL) { - class = nsdp->d_class; - dname = (char *)nsdp->d_data; - dprintf(3, (ddt, "nslookup: NS \"%s\" c=%d t=%d (%#lx)\n", - 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) { - dprintf(2, (ddt, - "skipping used NS w/name %s\n", - nsdp->d_data)); - goto skipserver; - } - } - - tmphtp = ((nsdp->d_flags & DB_F_HINT) ?fcachetab :hashtab); - np = nlookup(dname, &tmphtp, &fname, 1); - if (np == NULL) { - dprintf(3, (ddt, "%s: not found %s %lx\n", - dname, fname, (u_long)np)); - found_arr = 0; - goto need_sysquery; - } - if (fname != dname) { - if (findMyZone(np, class) == DB_Z_CACHE) { - /* - * lifted from findMyZone() - * We really need to know if the NS - * is the bottom of one of our zones - * to see if we've got missing glue - */ - for (; np; np = np_parent(np)) - for (dp = np->n_data; dp; dp = dp->d_next) - if (match(dp, class, T_NS)) { -#ifdef NCACHE - if (dp->d_rcode) - break; -#endif - if (dp->d_zone) { - static char *complaint = - "Glue A RR missing"; - nslookupComplain(sysloginfo, - syslogdname, - complaint, - dname, dp, - nsdp); - goto skipserver; - } else { - found_arr = 0; - goto need_sysquery; - } - } - /* shouldn't happen, but ... */ - found_arr = 0; - goto need_sysquery; - } else { - /* Authoritative A RR missing. */ - continue; - } - } - found_arr = 0; - oldn = n; - - /* look for name server addresses */ - 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"; -#ifdef NCACHE - if (dp->d_rcode) - continue; -#endif - nslookupComplain(sysloginfo, syslogdname, - complaint, dname, dp, nsdp); - goto skipserver; - } - if (dp->d_type != T_A || dp->d_class != class) - continue; -#ifdef NCACHE - if (dp->d_rcode) { - static const char *complaint = - "A RR negative cache entry"; - nslookupComplain(sysloginfo, syslogdname, - complaint, dname, dp, nsdp); - goto skipserver; - } -#endif - if (data_inaddr(dp->d_data).s_addr == 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 (ntohl(data_inaddr(dp->d_data).s_addr) == - INADDR_LOOPBACK) { - static const char *complaint = - "Bogus LOOPBACK A RR"; - nslookupComplain(sysloginfo, syslogdname, - complaint, dname, dp, nsdp); - continue; - } -#endif -#ifdef INADDR_BROADCAST - if (ntohl(data_inaddr(dp->d_data).s_addr) == - 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(ntohl(data_inaddr(dp->d_data).s_addr))) { - 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 == 0) && - (dp->d_ttl < curtime) && - !(dp->d_flags & DB_F_HINT) ) - { - syslog(LOG_DEBUG, "nslookup: stale '%s'\n", - NAME(*np)); - n = oldn; - found_arr = 0; - goto need_sysquery; - } -#ifdef VALIDATE - /* anant@isi.edu validation procedure, maintains a - * table of server names-addresses used recently - */ - store_name_addr(dname, data_inaddr(dp->d_data), - syslogdname, sysloginfo); -#endif /*VALIDATE*/ - - found_arr++; - nsa = data_inaddr(dp->d_data); - /* don't put in duplicates */ - qs = qp->q_addr; - for (i = 0; i < n; i++, qs++) - if (qs->ns_addr.sin_addr.s_addr == nsa.s_addr) - goto skipaddr; - qs->ns_addr.sin_family = AF_INET; - qs->ns_addr.sin_port = ns_port; - qs->ns_addr.sin_addr = nsa; - qs->ns = nsdp; - qs->nsdata = dp; - 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 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 (bcmp((char *)&qp->q_from, (char *)&qs->ns_addr, - sizeof(qp->q_from)) == 0) - { - static 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 (addr_on_netlist(nsa, boglist)) - goto skipserver; -#endif - - n++; - if (n >= NSMAX) - goto out; - skipaddr: - NULL; - } - dprintf(8, (ddt, "nslookup: %d ns addrs\n", n)); - need_sysquery: - if (found_arr == 0) { - potential_ns++; - if (!(qp->q_flags & Q_SYSTEM)) - (void) sysquery(dname, class, T_A, NULL, 0, - QUERY); - } - skipserver: - NULL; - } - out: - dprintf(3, (ddt, "nslookup: %d ns addrs total\n", n)); - qp->q_naddr = n; - if (n == 0 && potential_ns == 0 && !fwdtab) { - static char *complaint = "No possible A RRs"; - if (sysloginfo && syslogdname && - !haveComplained(syslogdname, complaint)) - { - syslog(LOG_INFO, "%s: query(%s) %s", - sysloginfo, syslogdname, complaint); - } - return(-1); - } - /* Update the refcounts before the sort. */ - for (i = naddr; i < n; i++) { - qp->q_addr[i].nsdata->d_rcnt++; - qp->q_addr[i].ns->d_rcnt++; - } - if (n > 1) { - qsort((char *)qp->q_addr, n, sizeof(struct qserv), - (int (*)__P((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 128 /* milliseconds; 0.128 seconds */ - -#define sign(x) (((x) < 0) ? -1 : ((x) > 0) ? 1 : 0) -#define RTTROUND(rtt) (((rtt) + (NOISE >> 1)) & ~(NOISE - 1)) - -int -qcomp(qs1, qs2) - struct qserv *qs1, *qs2; -{ - int pos1, pos2, pdiff; - u_long rtt1, rtt2; - long tdiff; - - if ((!qs1->nsdata) || (!qs2->nsdata)) - return 0; - rtt1 = qs1->nsdata->d_nstime; - rtt2 = qs2->nsdata->d_nstime; - - dprintf(10, (ddt, "qcomp(%s, %s) %lu (%lu) - %lu (%lu) = %lu", - inet_ntoa(qs1->ns_addr.sin_addr), - inet_ntoa(qs2->ns_addr.sin_addr), - rtt1, RTTROUND(rtt1), rtt2, RTTROUND(rtt2), - rtt1 - rtt2)); - if (RTTROUND(rtt1) == RTTROUND(rtt2)) { - pos1 = position_on_netlist(qs1->ns_addr.sin_addr, nettab); - pos2 = position_on_netlist(qs2->ns_addr.sin_addr, nettab); - pdiff = pos1 - pos2; - dprintf(10, (ddt, ", pos1=%d, pos2=%d\n", pos1, pos2)); - if (pdiff) - return (pdiff); - } else { - dprintf(10, (ddt, "\n")); - } - tdiff = rtt1 - rtt2; - return (sign(tdiff)); -} -#undef sign -#undef RTTROUND - -/* - * Arrange that forwarded query (qp) is retried after t seconds. - * Query list will be sorted after z_time is updated. - */ -void -schedretry(qp, t) - struct qinfo *qp; - time_t t; -{ - register struct qinfo *qp1, *qp2; - -#ifdef DEBUG - if (debug > 3) { - fprintf(ddt, "schedretry(0x%lx, %ld sec)\n", - (u_long)qp, (long)t); - if (qp->q_time) - fprintf(ddt, - "WARNING: schedretry(%#lx, %ld) q_time already %ld\n", - (u_long)qp, (long)t, (long)qp->q_time); - } -#endif - t += (u_long) tt.tv_sec; - qp->q_time = t; - - if ((qp1 = retryqp) == NULL) { - retryqp = qp; - qp->q_next = NULL; - return; - } - if (t < qp1->q_time) { - qp->q_next = qp1; - retryqp = qp; - return; - } - while ((qp2 = qp1->q_next) != NULL && qp2->q_time < t) - qp1 = qp2; - qp1->q_next = qp; - qp->q_next = qp2; -} - -/* - * Unsched is called to remove a forwarded query entry. - */ -void -unsched(qp) - struct qinfo *qp; -{ - register struct qinfo *np; - - dprintf(3, (ddt, "unsched(%#lx, %d)\n", (u_long)qp, ntohs(qp->q_id))); - if (retryqp == qp) { - retryqp = qp->q_next; - } else { - for (np=retryqp; np->q_next != QINFO_NULL; np = np->q_next) { - if (np->q_next != qp) - continue; - np->q_next = qp->q_next; /* dequeue */ - break; - } - } - qp->q_next = QINFO_NULL; /* sanity check */ - qp->q_time = 0; -} - -/* - * Retry is called to retransmit query 'qp'. - */ -void -retry(qp) - register struct qinfo *qp; -{ - register int n; - register HEADER *hp; - struct sockaddr_in *nsa; - - dprintf(3, (ddt, "retry(x%lx) id=%d\n", (u_long)qp, ntohs(qp->q_id))); - - if (qp->q_msg == NULL) { /* XXX - why? */ - qremove(qp); - return; - } - - if (qp->q_expire && (qp->q_expire < tt.tv_sec)) { - dprintf(1, (ddt, - "retry(x%lx): expired @ %lu (%d secs before now (%lu))\n", - (u_long)qp, (u_long)qp->q_expire, - (int)(tt.tv_sec - qp->q_expire), - (u_long)tt.tv_sec)); - if (qp->q_stream || (qp->q_flags & Q_PRIMING)) - goto fail; - qremove(qp); - return; - } - - /* try next address */ - n = qp->q_curaddr; - if (qp->q_fwd) { - qp->q_fwd = qp->q_fwd->next; - if (qp->q_fwd) - goto found; - /* out of forwarders, try direct queries */ - } else - ++qp->q_addr[n].nretry; - if (!forward_only) { - do { - if (++n >= (int)qp->q_naddr) - n = 0; - if (qp->q_addr[n].nretry < MAXRETRY) - goto found; - } while (n != qp->q_curaddr); - } -fail: - /* - * Give up. Can't reach destination. - */ - hp = (HEADER *)(qp->q_cmsg ? qp->q_cmsg : qp->q_msg); - if (qp->q_flags & Q_PRIMING) { - /* Can't give up priming */ - unsched(qp); - schedretry(qp, (time_t)60*60); /* 1 hour */ - hp->rcode = NOERROR; /* Lets be safe, reset the query */ - hp->qr = hp->aa = 0; - qp->q_fwd = fwdtab; - for (n = 0; n < (int)qp->q_naddr; n++) - qp->q_addr[n].nretry = 0; - return; - } - dprintf(5, (ddt, "give up\n")); - n = ((HEADER *)qp->q_cmsg ? qp->q_cmsglen : qp->q_msglen); - hp->id = qp->q_id; - hp->qr = 1; - hp->ra = (NoRecurse == 0); - hp->rd = 1; - hp->rcode = SERVFAIL; -#ifdef DEBUG - if (debug >= 10) - fp_nquery(qp->q_msg, n, ddt); -#endif - if (send_msg((u_char *)hp, n, qp)) { - dprintf(1, (ddt, "gave up retry(x%lx) nsid=%d id=%d\n", - (u_long)qp, ntohs(qp->q_nsid), ntohs(qp->q_id))); - } -#ifdef XSTATS - nameserIncr(qp->q_from.sin_addr, nssSentFail); -#endif - qremove(qp); - return; - -found: - if (qp->q_fwd == 0 && 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_fwd ? 1 : 0); - nsa = Q_NEXTADDR(qp, n); - dprintf(1, (ddt, - "%s(addr=%d n=%d) -> [%s].%d ds=%d nsid=%d id=%d %dms\n", - (qp->q_fwd ? "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) - fp_nquery(qp->q_msg, qp->q_msglen, ddt); -#endif - /* NOSTRICT */ - if (sendto(ds, (char*)qp->q_msg, qp->q_msglen, 0, - (struct sockaddr *)nsa, - sizeof(struct sockaddr_in)) < 0) { - dprintf(3, (ddt, "error resending msg errno=%d\n", errno)); - } - hp->rd = 1; /* leave set to 1 for dup detection */ - nameserIncr(nsa->sin_addr, nssSentDupQ); - unsched(qp); -#ifdef SLAVE_FORWARD - if(forward_only) - schedretry(qp, (time_t)slave_retry); - else -#endif /* SLAVE_FORWARD */ - schedretry(qp, qp->q_fwd ? (2*RETRYBASE) : 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(qp) - 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 */ - dprintf(3, (ddt, "retrytime: nstime%ldms t%ld nretry%ld u%ld : v%ld\n", - 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 = QINFO_NULL; - priming = 0; -} - -void -qremove(qp) - register struct qinfo *qp; -{ - dprintf(3, (ddt, "qremove(x%lx)\n", (u_long)qp)); - - if (qp->q_flags & Q_ZSERIAL) - qserial_answer(qp, 0); - unsched(qp); - qfree(qp); -} - -#if defined(__STDC__) || defined(__GNUC__) -struct qinfo * -qfindid(u_int16_t id) -#else -struct qinfo * -qfindid(id) - register u_int16_t id; -#endif -{ - register struct qinfo *qp; - - dprintf(3, (ddt, "qfindid(%d)\n", ntohs(id))); - for (qp = nsqhead; qp!=QINFO_NULL; qp = qp->q_link) { - if (qp->q_nsid == id) - return(qp); - } - dprintf(5, (ddt, "qp not found\n")); - return (NULL); -} - -struct qinfo * -qnew(name, class, type) - const char *name; - int class; - int type; -{ - register struct qinfo *qp; - - qp = (struct qinfo *)calloc(1, sizeof(struct qinfo)); - if (qp == NULL) - panic(ENOMEM, "qnew: calloc failed"); - dprintf(5, (ddt, "qnew(%#x)\n", qp)); -#ifdef BIND_NOTIFY - qp->q_notifyzone = DB_Z_CACHE; -#endif - qp->q_link = nsqhead; - nsqhead = qp; - qp->q_name = strdup(name); - if (!qp->q_name) - panic(ENOMEM, "qnew: strdup failed"); - qp->q_class = (u_int16_t)class; - qp->q_type = (u_int16_t)type; - return (qp); -} - -void -nsfree(qp, where) - struct qinfo *qp; - char *where; -{ - static const char freed[] = "freed", busy[] = "busy"; - const char *result; - struct databuf *dp; - int i; - - for (i = 0 ; i < (int)qp->q_naddr ; i++) { - dp = qp->q_addr[i].ns; - if (dp) { - result = (--(dp->d_rcnt)) ? busy : freed; - dprintf(1, (ddt, "%s: ns %s rcnt %d (%s)\n", - where, dp->d_data, dp->d_rcnt, result)); - if (result == freed) - db_free(dp); - } - dp = qp->q_addr[i].nsdata; - if (dp) { - result = (--(dp->d_rcnt)) ? busy : freed; - dprintf(1, (ddt, "%s: nsdata %s rcnt %d (%s)\n", - where, inet_ntoa(data_inaddr(dp->d_data)), - dp->d_rcnt, result)); - if (result == freed) - db_free(dp); - } - } -} - -void -qfree(qp) - struct qinfo *qp; -{ - struct qinfo *np; - struct databuf *dp; - - dprintf(3, (ddt, "Qfree(x%lx)\n", (u_long)qp)); - if (qp->q_next) - dprintf(1, (ddt, "WARNING: qfree of linked ptr x%lx\n", - (u_long)qp)); - if (qp->q_msg) - free(qp->q_msg); - if (qp->q_cmsg) - free(qp->q_cmsg); - if (qp->q_domain) - free(qp->q_domain); - if (qp->q_name) - free(qp->q_name); - nsfree(qp, "qfree"); - if (nsqhead == qp) - nsqhead = qp->q_link; - else { - for (np = nsqhead; np->q_link != QINFO_NULL; np = np->q_link) { - if (np->q_link != qp) - continue; - np->q_link = qp->q_link; /* dequeue */ - break; - } - } - free((char*)qp); -} |