910 lines
25 KiB
C
910 lines
25 KiB
C
#if !defined(lint) && !defined(SABER)
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static char sccsid[] = "@(#)ns_forw.c 4.32 (Berkeley) 3/3/91";
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static char rcsid[] = "$Id: ns_forw.c,v 4.9.1.17 1994/07/23 23:23:56 vixie Exp $";
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#endif /* not lint */
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/*
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* ++Copyright++ 1986
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* -
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* Copyright (c) 1986
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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* -
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* Portions Copyright (c) 1993 by Digital Equipment Corporation.
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies, and that
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* the name of Digital Equipment Corporation not be used in advertising or
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* publicity pertaining to distribution of the document or software without
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* specific, written prior permission.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
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* WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
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* CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
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* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
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* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
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* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
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* SOFTWARE.
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* -
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* --Copyright--
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*/
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#include <sys/param.h>
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#include <sys/socket.h>
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#include <netinet/in.h>
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#include <arpa/inet.h>
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#include <arpa/nameser.h>
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#include <syslog.h>
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#include <resolv.h>
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#include <stdio.h>
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#include <errno.h>
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#include "named.h"
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/*
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* Forward the query to get the answer since its not in the database.
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* Returns FW_OK if a request struct is allocated and the query sent.
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* Returns FW_DUP if this is a duplicate of a pending request.
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* Returns FW_NOSERVER if there were no addresses for the nameservers.
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* Returns FW_SERVFAIL on malloc error or if asked to do something
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* dangerous, such as fwd to ourselves or fwd to the host that asked us.
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*
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* (no action is taken on errors and qpp is not filled in.)
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*/
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int
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ns_forw(nsp, msg, msglen, fp, qsp, dfd, qpp, dname, np)
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struct databuf *nsp[];
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u_char *msg;
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int msglen;
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struct sockaddr_in *fp;
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struct qstream *qsp;
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int dfd;
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struct qinfo **qpp;
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char *dname;
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struct namebuf *np;
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{
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register struct qinfo *qp;
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struct sockaddr_in *nsa;
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HEADER *hp;
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u_int16_t id;
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int n;
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dprintf(3, (ddt, "ns_forw()\n"));
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hp = (HEADER *) msg;
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id = hp->id;
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/* Look at them all */
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for (qp = qhead; qp!=QINFO_NULL; qp = qp->q_link) {
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if (qp->q_id == id &&
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bcmp((char *)&qp->q_from, fp, sizeof(qp->q_from)) == 0 &&
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((qp->q_cmsglen == 0 && qp->q_msglen == msglen &&
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bcmp((char *)qp->q_msg+2, msg+2, msglen-2) == 0) ||
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(qp->q_cmsglen == msglen &&
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bcmp((char *)qp->q_cmsg+2, msg+2, msglen-2) == 0))) {
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dprintf(3, (ddt,
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"forw: dropped DUP id=%d\n", ntohs(id)));
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nameserIncr(fp->sin_addr, nssRcvdDupQ);
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return (FW_DUP);
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}
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}
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qp = qnew();
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#ifdef LAME_DELEGATION
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getname(np, qp->q_domain, sizeof qp->q_domain);
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#endif
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qp->q_from = *fp; /* nslookup wants to know this */
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if ((n = nslookup(nsp, qp, dname, "ns_forw")) < 0) {
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dprintf(2, (ddt, "forw: nslookup reports danger\n"));
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qfree(qp);
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return (FW_SERVFAIL);
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} else if (n == 0 && !(forward_only && fwdtab)) {
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dprintf(2, (ddt, "forw: no nameservers found\n"));
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qfree(qp);
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return (FW_NOSERVER);
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}
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qp->q_stream = qsp;
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qp->q_curaddr = 0;
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qp->q_fwd = fwdtab;
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qp->q_dfd = dfd;
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qp->q_id = id;
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qp->q_expire = tt.tv_sec + RETRY_TIMEOUT*2;
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hp->id = qp->q_nsid = htons((u_int16_t)++nsid);
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hp->ancount = 0;
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hp->nscount = 0;
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hp->arcount = 0;
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if ((qp->q_msg = (u_char *)malloc((unsigned)msglen)) == NULL) {
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syslog(LOG_ERR, "forw: %m");
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qfree(qp);
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return (FW_SERVFAIL);
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}
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bcopy(msg, qp->q_msg, qp->q_msglen = msglen);
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if (!qp->q_fwd) {
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hp->rd = 0;
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qp->q_addr[0].stime = tt;
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}
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#ifdef SLAVE_FORWARD
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if (forward_only)
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schedretry(qp, (time_t)slave_retry);
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else
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#endif /* SLAVE_FORWARD */
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schedretry(qp, qp->q_fwd ?(2*RETRYBASE) :retrytime(qp));
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nsa = Q_NEXTADDR(qp, 0);
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dprintf(1, (ddt,
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"forw: forw -> [%s].%d ds=%d nsid=%d id=%d %dms retry %dsec\n",
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inet_ntoa(nsa->sin_addr),
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ntohs(nsa->sin_port), ds,
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ntohs(qp->q_nsid), ntohs(qp->q_id),
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(qp->q_addr[0].nsdata != NULL)
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? qp->q_addr[0].nsdata->d_nstime
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: -1,
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qp->q_time - tt.tv_sec));
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#ifdef DEBUG
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if (debug >= 10)
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fp_query(msg, ddt);
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#endif
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if (sendto(ds, msg, msglen, 0, (struct sockaddr *)nsa,
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sizeof(struct sockaddr_in)) < 0) {
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if (!haveComplained((char*)nsa->sin_addr.s_addr, sendtoStr))
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syslog(LOG_NOTICE, "ns_forw: sendto([%s].%d): %m",
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inet_ntoa(nsa->sin_addr), ntohs(nsa->sin_port));
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nameserIncr(nsa->sin_addr, nssSendtoErr);
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}
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nameserIncr(fp->sin_addr, nssRcvdFwdQ);
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nameserIncr(nsa->sin_addr, nssSentFwdQ);
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if (qpp)
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*qpp = qp;
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hp->rd = 1;
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return (0);
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}
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/* struct qdatagram *
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* aIsUs(addr)
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* scan the datagramq (our list of interface addresses) for "addr"
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* returns:
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* pointer to qdatagram entry or NULL if no match is found
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* notes:
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* INADDR_ANY ([0.0.0.0]) is on the datagramq, so it's considered "us"
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* author:
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* Paul Vixie (DECWRL) April 1991
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*/
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struct qdatagram *
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aIsUs(addr)
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struct in_addr addr;
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{
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struct qdatagram *dqp;
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for (dqp = datagramq; dqp != QDATAGRAM_NULL; dqp = dqp->dq_next) {
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if (addr.s_addr == dqp->dq_addr.s_addr) {
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return dqp;
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}
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}
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return NULL;
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}
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/* haveComplained(tag1, tag2)
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* check to see if we have complained about (tag1,tag2) recently
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* (note that these are declared as pointers but are never deref'd)
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* returns:
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* boolean: have we complained recently?
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* side-effects:
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* outdated complaint records removed from our static list
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* author:
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* Paul Vixie (DECWRL) April 1991
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*/
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int
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haveComplained(tag1, tag2)
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char *tag1, *tag2;
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{
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struct complaint {
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char *tag1, *tag2;
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time_t expire;
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struct complaint *next;
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};
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static struct complaint *List = NULL;
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struct complaint *cur, *next, *prev;
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int r = 0;
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for (cur = List, prev = NULL; cur; prev = cur, cur = next) {
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next = cur->next;
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if (tt.tv_sec > cur->expire) {
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if (prev)
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prev->next = next;
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else
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List = next;
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free((char*) cur);
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cur = prev;
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} else if ((tag1 == cur->tag1) && (tag2 == cur->tag2)) {
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r++;
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}
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}
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if (!r) {
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cur = (struct complaint *)malloc(sizeof(struct complaint));
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cur->tag1 = tag1;
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cur->tag2 = tag2;
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cur->expire = tt.tv_sec + INIT_REFRESH; /* "10 minutes" */
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cur->next = NULL;
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if (prev)
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prev->next = cur;
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else
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List = cur;
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}
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return r;
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}
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/* void
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* nslookupComplain(sysloginfo, queryname, complaint, dname, a_rr)
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* Issue a complaint about a dangerous situation found by nslookup().
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* params:
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* sysloginfo is a string identifying the complainant.
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* queryname is the domain name associated with the problem.
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* complaint is a string describing what is wrong.
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* dname and a_rr are the problematic other name server.
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*/
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void
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nslookupComplain(sysloginfo, queryname, complaint, dname, a_rr)
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char *sysloginfo, *queryname, *complaint, *dname;
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register struct databuf *a_rr;
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{
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dprintf(2, (ddt, "NS '%s' %s\n", dname, complaint));
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if (sysloginfo && queryname && !haveComplained(queryname, complaint))
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{
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char buf[512];
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/* syslog only takes 5 params */
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sprintf(buf, "%s: query(%s) %s (%s:%s)",
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sysloginfo, queryname,
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complaint, dname, inet_ntoa(
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*(struct in_addr*)a_rr->d_data
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));
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syslog(LOG_INFO, buf);
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}
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}
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/*
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* nslookup(nsp, qp, syslogdname, sysloginfo)
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* Lookup the address for each nameserver in `nsp' and add it to
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* the list saved in the qinfo structure pointed to by `qp'.
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* Omits information about nameservers that we shouldn't ask.
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* Detects the following dangerous operations:
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* One of the A records for one of the nameservers in nsp
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* refers to the address of one of our own interfaces;
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* One of the A records refers to the nameserver port on
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* the host that asked us this question.
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* returns: the number of addresses added, or -1 if a dangerous operation
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* is detected.
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* side effects:
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* if a dangerous situation is detected and (syslogdname && sysloginfo),
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* calls syslog.
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*/
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int
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nslookup(nsp, qp, syslogdname, sysloginfo)
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struct databuf *nsp[];
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register struct qinfo *qp;
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char *syslogdname;
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char *sysloginfo;
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{
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register struct namebuf *np;
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register struct databuf *dp, *nsdp;
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register struct qserv *qs;
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register int n;
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register unsigned int i;
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struct hashbuf *tmphtp;
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char *dname, *fname;
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int oldn, naddr, class, found_arr;
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time_t curtime;
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dprintf(3, (ddt, "nslookup(nsp=0x%x, qp=0x%x, \"%s\")\n",
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nsp, qp, syslogdname));
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naddr = n = qp->q_naddr;
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curtime = (u_long) tt.tv_sec;
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while ((nsdp = *nsp++) != NULL) {
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class = nsdp->d_class;
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dname = (char *)nsdp->d_data;
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dprintf(3, (ddt, "nslookup: NS \"%s\" c=%d t=%d (0x%x)\n",
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dname, class, nsdp->d_type, nsdp->d_flags));
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/* don't put in servers we have tried */
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for (i = 0; i < qp->q_nusedns; i++) {
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if (qp->q_usedns[i] == nsdp) {
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dprintf(2, (ddt,
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"skipping used NS w/name %s\n",
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nsdp->d_data));
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goto skipserver;
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}
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}
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tmphtp = ((nsdp->d_flags & DB_F_HINT) ?fcachetab :hashtab);
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np = nlookup(dname, &tmphtp, &fname, 1);
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if (np == NULL || fname != dname) {
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dprintf(3, (ddt, "%s: not found %s %x\n",
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dname, fname, np));
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continue;
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}
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found_arr = 0;
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oldn = n;
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/* look for name server addresses */
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for (dp = np->n_data; dp != NULL; dp = dp->d_next) {
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struct in_addr nsa;
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if (dp->d_type == T_CNAME && dp->d_class == class)
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goto skipserver;
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if (dp->d_type != T_A || dp->d_class != class)
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continue;
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#ifdef NCACHE
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if (dp->d_rcode)
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continue;
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#endif
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/*
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* Don't use records that may become invalid to
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* reference later when we do the rtt computation.
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* Never delete our safety-belt information!
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*/
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if ((dp->d_zone == 0) &&
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(dp->d_ttl < (curtime+900)) &&
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!(dp->d_flags & DB_F_HINT) )
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{
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dprintf(3, (ddt,
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"nslookup: stale entry '%s'\n",
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np->n_dname));
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/* Cache invalidate the NS RR's */
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if (dp->d_ttl < curtime)
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delete_all(np, class, T_A);
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n = oldn;
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break;
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}
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#ifdef VALIDATE
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/* anant@isi.edu validation procedure, maintains a
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* table of server names-addresses used recently
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*/
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store_name_addr(dname, (struct in_addr *)dp->d_data,
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syslogdname, sysloginfo);
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#endif /*VALIDATE*/
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found_arr++;
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nsa = *(struct in_addr *)dp->d_data;
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/* don't put in duplicates */
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qs = qp->q_addr;
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for (i = 0; i < n; i++, qs++)
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if (qs->ns_addr.sin_addr.s_addr == nsa.s_addr)
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goto skipaddr;
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qs->ns_addr.sin_family = AF_INET;
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qs->ns_addr.sin_port = ns_port;
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qs->ns_addr.sin_addr = nsa;
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qs->ns = nsdp;
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qs->nsdata = dp;
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qs->nretry = 0;
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/*
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* if we are being asked to fwd a query whose
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* nameserver list includes our own name/address(es),
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* then we have detected a lame delegation and rather
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* than melt down the network and hose down the other
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* servers (who will hose us in return), we'll return
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* -1 here which will cause SERVFAIL to be sent to
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* the client's resolver which will hopefully then
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* shut up.
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*
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* (originally done in nsContainsUs by vix@dec mar92;
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* moved into nslookup by apb@und jan1993)
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*/
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if (aIsUs(nsa)) {
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static char *complaint = "contains our address";
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nslookupComplain(sysloginfo, syslogdname,
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complaint, dname, dp);
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return (-1);
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}
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/*
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* If we want to forward to a host that asked us
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* this question then either we or they are sick
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* (unless they asked from some port other than
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* their nameserver port). (apb@und jan1993)
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*/
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if (bcmp((char *)&qp->q_from, (char *)&qs->ns_addr,
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sizeof(qp->q_from)) == 0)
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{
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static char *complaint = "forwarding loop";
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nslookupComplain(sysloginfo, syslogdname,
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complaint, dname, dp);
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return (-1);
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}
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/*
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* Don't forward queries to bogus servers. Note
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* that this is unlike the previous tests, which
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* are fatal to the query. Here we just skip the
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* server, which is only fatal if it's the last
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* server. Note also that we antialias here -- all
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* A RR's of a server are considered the same server,
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* and if any of them is bogus we skip the whole
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* server. Those of you using multiple A RR's to
|
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* load-balance your servers will (rightfully) lose
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* here. But (unfortunately) only if they are bogus.
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*/
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|
if (addr_on_netlist(nsa, boglist))
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goto skipserver;
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n++;
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if (n >= NSMAX)
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goto out;
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|
skipaddr: ;
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}
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|
dprintf(8, (ddt, "nslookup: %d ns addrs\n", n));
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|
if (found_arr == 0 && !(qp->q_flags & Q_SYSTEM))
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(void) sysquery(dname, class, T_A, NULL, 0);
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skipserver: ;
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}
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out:
|
|
dprintf(3, (ddt, "nslookup: %d ns addrs total\n", n));
|
|
qp->q_naddr = n;
|
|
#ifdef DATUMREFCNT
|
|
/* must be run before the sort */
|
|
for (i = naddr ; i < n ; i++) {
|
|
qp->q_addr[i].nsdata->d_rcnt++;
|
|
qp->q_addr[i].ns->d_rcnt++;
|
|
}
|
|
#endif
|
|
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%x, %ld sec)\n", qp, (long)t);
|
|
if (qp->q_time)
|
|
fprintf(ddt,
|
|
"WARNING: schedretry(%#x, %d) q_time already %d\n",
|
|
qp, t, 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(%#x, %d )\n", 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%x) id=%d\n", 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%x): expired @ %d (%d secs before now (%d))\n",
|
|
qp, qp->q_expire, tt.tv_sec - qp->q_expire,
|
|
tt.tv_sec));
|
|
if (qp->q_stream) /* return failure code on stream */
|
|
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 = 1;
|
|
hp->rd = 1;
|
|
hp->rcode = SERVFAIL;
|
|
#ifdef DEBUG
|
|
if (debug >= 10)
|
|
fp_query(qp->q_msg, ddt);
|
|
#endif
|
|
if (send_msg((u_char *)hp, n, qp)) {
|
|
dprintf(1, (ddt,"gave up retry(x%x) nsid=%d id=%d\n",
|
|
qp, ntohs(qp->q_nsid), ntohs(qp->q_id)));
|
|
}
|
|
nameserIncr(qp->q_from.sin_addr, nssSentFail);
|
|
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_query(qp->q_msg, ddt);
|
|
#endif
|
|
/* NOSTRICT */
|
|
if (sendto(ds, 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 (qhead)
|
|
qremove(qhead);
|
|
qhead = QINFO_NULL;
|
|
}
|
|
|
|
void
|
|
qremove(qp)
|
|
register struct qinfo *qp;
|
|
{
|
|
dprintf(3, (ddt, "qremove(x%x)\n", 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 = qhead; 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 *
|
|
#ifdef DMALLOC
|
|
qnew_tagged(file, line)
|
|
char *file;
|
|
int line;
|
|
#else
|
|
qnew()
|
|
#endif
|
|
{
|
|
register struct qinfo *qp;
|
|
|
|
if ((qp = (struct qinfo *)
|
|
#ifdef DMALLOC
|
|
dcalloc(file, line,
|
|
#else
|
|
calloc(
|
|
#endif
|
|
1, sizeof(struct qinfo))) == NULL) {
|
|
dprintf(5, (ddt, "qnew: calloc error\n"));
|
|
syslog(LOG_ERR, "forw: %m");
|
|
exit(12);
|
|
}
|
|
dprintf(5, (ddt, "qnew(x%x)\n", qp));
|
|
qp->q_link = qhead;
|
|
qhead = qp;
|
|
return (qp);
|
|
}
|
|
|
|
void
|
|
qfree(qp)
|
|
struct qinfo *qp;
|
|
{
|
|
register struct qinfo *np;
|
|
register struct databuf *dp;
|
|
#ifdef DATUMREFCNT
|
|
int i;
|
|
#endif
|
|
|
|
#ifdef DEBUG
|
|
if(debug > 3)
|
|
fprintf(ddt,"Qfree( x%x )\n", qp);
|
|
if(debug && qp->q_next)
|
|
fprintf(ddt,"WARNING: qfree of linked ptr x%x\n", qp);
|
|
#endif
|
|
if (qp->q_msg)
|
|
free(qp->q_msg);
|
|
if (qp->q_cmsg)
|
|
free(qp->q_cmsg);
|
|
#ifdef DATUMREFCNT
|
|
for (i = 0 ; i < (int)qp->q_naddr ; i++) {
|
|
dp = qp->q_addr[i].ns;
|
|
if (dp)
|
|
if (--(dp->d_rcnt)) {
|
|
dprintf(3, (ddt, "qfree: ns %s rcnt %d\n",
|
|
dp->d_data,
|
|
dp->d_rcnt));
|
|
} else {
|
|
dprintf(3, (ddt, "qfree: ns %s rcnt %d delayed\n",
|
|
dp->d_data,
|
|
dp->d_rcnt));
|
|
free((char*)dp);
|
|
}
|
|
dp = qp->q_addr[i].nsdata;
|
|
if (dp)
|
|
if ((--(dp->d_rcnt))) {
|
|
dprintf(3, (ddt, "qfree: nsdata %08.8X rcnt %d\n",
|
|
*(int32_t *)(dp->d_data),
|
|
dp->d_rcnt));
|
|
} else {
|
|
dprintf(3, (ddt, "qfree: nsdata %08.8X rcnt %d delayed\n",
|
|
*(int32_t *)(dp->d_data),
|
|
dp->d_rcnt));
|
|
free((char*)dp);
|
|
}
|
|
}
|
|
#endif
|
|
if( qhead == qp ) {
|
|
qhead = qp->q_link;
|
|
} else {
|
|
for( np=qhead; 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);
|
|
}
|