4.4BSD/usr/src/contrib/bind-4.9/named/ns_forw.c
#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 4.9.1.1 1993/05/02 22:43:03 vixie Rel $";
#endif /* not lint */
/*
* ++Copyright++ 1986
* -
* Copyright (c) 1986 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/param.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <arpa/inet.h>
#include <syslog.h>
#include <resolv.h>
#include <stdio.h>
#include <errno.h>
#include "../conf/portability.h"
#include "../conf/options.h"
#include "ns.h"
#include "db.h"
struct qinfo *qhead = QINFO_NULL; /* head of allocated queries */
struct qinfo *retryqp = QINFO_NULL; /* list of queries to retry */
struct fwdinfo *fwdtab; /* list of forwarding hosts */
int nsid; /* next forwarded query id */
extern int forward_only; /* you are only a slave */
extern u_short ns_port;
#ifdef SLAVE_FORWARD
extern int slave_retry; /* retry time when a slave */
#endif
void qfree(), qflush(), qremove(),
schedretry(), unsched(), retry();
time_t retrytime();
int nslookup();
/*
* 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)
struct databuf *nsp[];
u_char *msg;
int msglen;
struct sockaddr_in *fp;
struct qstream *qsp;
int dfd;
struct qinfo **qpp;
char *dname;
{
register struct qinfo *qp;
HEADER *hp;
u_short id;
int n;
#ifdef DEBUG
if (debug >= 3)
fprintf(ddt,"ns_forw()\n");
#endif
/* Don't forward if we're already working on it. */
hp = (HEADER *) msg;
id = hp->id;
/* Look at them all */
for (qp = qhead; 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))) {
#ifdef DEBUG
if (debug >= 3)
fprintf(ddt,"forw: dropped DUP id=%d\n", ntohs(id));
#endif
#ifdef STATS
stats[S_DUPQUERIES].cnt++;
#endif
return (FW_DUP);
}
}
qp = qnew();
qp->q_from = *fp; /* nslookup wants to know this */
if ((n = nslookup(nsp, qp, dname, "ns_forw")) < 0) {
#ifdef DEBUG
if (debug >= 2)
fprintf(ddt,"forw: nslookup reports danger\n");
#endif
qfree(qp);
return (FW_SERVFAIL);
} else if (n == 0 && !(forward_only && fwdtab)) {
#ifdef DEBUG
if (debug >= 2)
fprintf(ddt,"forw: no nameservers found\n");
#endif
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((u_short)++nsid);
hp->ancount = 0;
hp->nscount = 0;
hp->arcount = 0;
if ((qp->q_msg = malloc((unsigned)msglen)) == NULL) {
syslog(LOG_ERR, "forw: %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));
#ifdef DEBUG
if (debug)
fprintf(ddt,
"forw: forw -> %s %d (%d) nsid=%d id=%d %dms retry %d sec\n",
inet_ntoa(Q_NEXTADDR(qp,0)->sin_addr),
ds, ntohs(Q_NEXTADDR(qp,0)->sin_port),
ntohs(qp->q_nsid), ntohs(qp->q_id),
(qp->q_addr[0].nsdata != NULL)
? qp->q_addr[0].nsdata->d_nstime
: -1,
qp->q_time - tt.tv_sec);
if (debug >= 10)
fp_query((char *)msg, ddt);
#endif
if (sendto(ds, msg, msglen, 0, (struct sockaddr *)Q_NEXTADDR(qp,0),
sizeof(struct sockaddr_in)) < 0){
#ifdef DEBUG
if (debug >= 5)
fprintf(ddt,"error returning msg errno=%d\n",errno);
#endif
}
#ifdef STATS
stats[S_OUTPKTS].cnt++;
#endif
if (qpp)
*qpp = qp;
hp->rd = 1;
return (0);
}
/* aIsUs(addr)
* scan the datagramq (our list of interface addresses) for "addr"
* returns:
* boolean: is "addr" on the datagramq list?
* author:
* Paul Vixie (DECWRL) April 1991
*/
int
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 1;
}
}
return 0;
}
/* 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)
char *tag1, *tag2;
{
struct complaint {
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));
cur->tag1 = tag1;
cur->tag2 = tag2;
cur->expire = tt.tv_sec + INIT_REFRESH; /* "10 minutes" */
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)
char *sysloginfo, *queryname, *complaint, *dname;
register struct databuf *a_rr;
{
#ifdef DEBUG
if (debug >= 2) {
fprintf(ddt,"NS '%s' %s\n", dname, complaint);
}
#endif
if (sysloginfo && queryname && !haveComplained(queryname, complaint))
{
char buf[512];
/* syslog only takes 5 params */
sprintf(buf, "%s: query(%s) %s (%s:%s)",
sysloginfo, queryname,
complaint, dname, inet_ntoa(
*(struct in_addr*)a_rr->d_data
));
syslog(LOG_INFO, 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;
char *syslogdname;
char *sysloginfo;
{
register struct namebuf *np;
register struct databuf *dp, *nsdp;
register struct qserv *qs;
register int n, i;
struct hashbuf *tmphtp;
char *dname, *fname;
int oldn, naddr, class, found_arr;
time_t curtime;
int qcomp();
#ifdef DEBUG
if (debug >= 3)
fprintf(ddt, "nslookup(nsp=x%x,qp=x%x,'%s')\n",
nsp, qp, syslogdname);
#endif
naddr = n = qp->q_naddr;
curtime = (u_long) tt.tv_sec;
while ((nsdp = *nsp++) != NULL) {
class = nsdp->d_class;
dname = (char *)nsdp->d_data;
#ifdef DEBUG
if (debug >= 3)
fprintf(ddt,"nslookup: NS %s c%d t%d (x%x)\n",
dname, class, nsdp->d_type, nsdp->d_flags);
#endif
/* don't put in people we have tried */
for (i = 0; i < qp->q_nusedns; i++)
if (qp->q_usedns[i] == nsdp) {
#ifdef DEBUG
if (debug >= 2)
fprintf(ddt,
"skipping used NS w/name %s\n",
nsdp->d_data);
#endif
goto skipserver;
}
tmphtp = ((nsdp->d_flags & DB_F_HINT) ? fcachetab : hashtab);
np = nlookup(dname, &tmphtp, &fname, 1);
if (np == NULL || fname != dname) {
#ifdef DEBUG
if (debug >= 3)
fprintf(ddt, "%s: not found %s %x\n",
dname, fname, np);
#endif
continue;
}
found_arr = 0;
oldn = n;
/* look for name server addresses */
for (dp = np->n_data; dp != NULL; dp = dp->d_next) {
if (dp->d_type == T_CNAME && dp->d_class == class)
goto skipserver;
if (dp->d_type != T_A || dp->d_class != class)
continue;
/*
* 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+900)) &&
!(dp->d_flags & DB_F_HINT) )
{
#ifdef DEBUG
if (debug >= 3)
fprintf(ddt,"nslookup: stale entry '%s'\n",
np->n_dname);
#endif
/* Cache invalidate the NS RR's */
if (dp->d_ttl < curtime)
delete_all(np, class, T_A);
n = oldn;
break;
}
found_arr++;
/* don't put in duplicates */
qs = qp->q_addr;
for (i = 0; i < n; i++, qs++)
if (qs->ns_addr.sin_addr.s_addr ==
((struct in_addr *)dp->d_data)->s_addr)
goto skipaddr;
qs->ns_addr.sin_family = AF_INET;
qs->ns_addr.sin_port = ns_port;
qs->ns_addr.sin_addr = *(struct in_addr *)dp->d_data;
qs->ns = nsdp;
qs->nsdata = dp;
qp->q_addr[n].nretry = 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)
*/
if (aIsUs(*(struct in_addr *)dp->d_data)) {
static char *complaint = "contains our address";
nslookupComplain(sysloginfo, syslogdname,
complaint, dname, dp);
return -1;
}
/*
* 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)
*/
if (bcmp((char *)&qp->q_from, &qs->ns_addr,
sizeof(qp->q_from)) == 0)
{
static char *complaint = "forwarding loop";
nslookupComplain(sysloginfo, syslogdname,
complaint, dname, dp);
return -1;
}
n++;
if (n >= NSMAX)
goto out;
skipaddr: ;
}
#ifdef DEBUG
if (debug >= 3)
fprintf(ddt,"nslookup: %d ns addrs\n", n);
#endif
if (found_arr == 0 && qp->q_system == 0)
(void) sysquery(dname, class, T_A);
skipserver: ;
}
out:
#ifdef DEBUG
if (debug >= 3)
fprintf(ddt,"nslookup: %d ns addrs total\n", n);
#endif
qp->q_naddr = n;
if (n > 1) {
qsort((char *)qp->q_addr, n, sizeof(struct qserv), 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 1024 /* ~1 second */
#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;
extern struct netinfo *nettab; /* sortlist */
rtt1 = qs1->nsdata->d_nstime;
rtt2 = qs2->nsdata->d_nstime;
#ifdef DEBUG
if (debug >= 10) {
fprintf(ddt, "qcomp(%s, ", inet_ntoa(qs1->ns_addr.sin_addr));
fprintf(ddt, "%s) ", inet_ntoa(qs2->ns_addr.sin_addr));
fprintf(ddt, "%lu (%lu) - %lu (%lu) = %lu",
rtt1, RTTROUND(rtt1), rtt2, RTTROUND(rtt2),
rtt1 - rtt2);
}
#endif
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;
#ifdef DEBUG
if (debug >= 10)
fprintf(ddt, ", pos1=%d, pos2=%d\n", pos1, pos2);
#endif
if (pdiff)
return (pdiff);
}
#ifdef DEBUG
else if (debug >= 10)
fprintf(ddt, "\n");
#endif
tdiff = rtt1 - rtt2;
return (sign(tdiff));
}
#undef sign
#undef RTTROUND
/*
* Arrange that forwarded query (qp) is retried after t seconds.
*/
void
schedretry(qp, t)
struct qinfo *qp;
time_t t;
{
register struct qinfo *qp1, *qp2;
#ifdef DEBUG
if (debug > 3) {
fprintf(ddt,"schedretry(%#x, %dsec)\n", qp, 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;
#ifdef DEBUG
if (debug > 3) {
fprintf(ddt,"unsched(%#x, %d )\n", qp, ntohs(qp->q_id));
}
#endif
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;
#ifdef DEBUG
if (debug > 3)
fprintf(ddt, "retry(x%x) id=%d\n", qp, ntohs(qp->q_id));
#endif
if((HEADER *)qp->q_msg == NULL) { /*** XXX ***/
qremove(qp);
return;
} /*** XXX ***/
if (qp->q_expire && (qp->q_expire < tt.tv_sec)) {
#ifdef DEBUG
if (debug)
fprintf(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);
#endif
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 >= qp->q_naddr)
n = 0;
if (qp->q_addr[n].nretry < MAXRETRY)
goto found;
} while (n != qp->q_curaddr);
}
/*
* Give up. Can't reach destination.
*/
hp = (HEADER *)(qp->q_cmsg ? qp->q_cmsg : qp->q_msg);
if (qp->q_system == PRIMING_CACHE) {
/* 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 < qp->q_naddr; n++)
qp->q_addr[n].nretry = 0;
return;
}
#ifdef DEBUG
if (debug >= 5)
fprintf(ddt,"give up\n");
#endif
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((char *)hp, n, qp)) {
#ifdef DEBUG
if (debug)
fprintf(ddt,"gave up retry(x%x) nsid=%d id=%d\n",
qp, ntohs(qp->q_nsid), ntohs(qp->q_id));
#endif
}
qremove(qp);
#ifdef STATS
stats[S_RESPFAIL].cnt++;
#endif
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);
#ifdef DEBUG
if (debug)
fprintf(ddt,
"%s(addr=%d n=%d) -> %s %d (%d) nsid=%d id=%d %dms\n",
(qp->q_fwd ? "reforw" : "resend"),
n, qp->q_addr[n].nretry,
inet_ntoa(Q_NEXTADDR(qp,n)->sin_addr),
ds, ntohs(Q_NEXTADDR(qp,n)->sin_port),
ntohs(qp->q_nsid), ntohs(qp->q_id),
qp->q_addr[n].nsdata->d_nstime);
if (debug >= 10)
fp_query(qp->q_msg, ddt);
#endif
/* NOSTRICT */
if (sendto(ds, qp->q_msg, qp->q_msglen, 0,
(struct sockaddr *)Q_NEXTADDR(qp,n),
sizeof(struct sockaddr_in)) < 0)
{
#ifdef DEBUG
if (debug > 3)
fprintf(ddt,"error resending msg errno=%d\n",errno);
#endif
}
hp->rd = 1; /* leave set to 1 for dup detection */
#ifdef STATS
stats[S_OUTPKTS].cnt++;
#endif
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)
register struct qinfo *qp;
{
time_t t;
struct qserv *ns = &qp->q_addr[qp->q_curaddr];
#ifdef DEBUG
if (debug > 3)
fprintf(ddt,"retrytime: nstime %dms.\n",
ns->nsdata->d_nstime / 1000);
#endif
t = (time_t) MAX(RETRYBASE, 2 * ns->nsdata->d_nstime / 1000);
t <<= ns->nretry;
t = MIN(t, RETRY_TIMEOUT); /* max. retry timeout for now */
#ifdef notdef
if (qp->q_system)
return ((2 * t) + 5); /* system queries can wait. */
#endif
return (t);
}
void
qflush()
{
while (qhead)
qremove(qhead);
qhead = QINFO_NULL;
}
void
qremove(qp)
register struct qinfo *qp;
{
#ifdef DEBUG
if(debug > 3)
fprintf(ddt,"qremove(x%x)\n", qp);
#endif
unsched(qp); /* get off queue first */
qfree(qp);
}
struct qinfo *
qfindid(id)
register u_short id;
{
register struct qinfo *qp;
#ifdef DEBUG
if(debug > 3)
fprintf(ddt,"qfindid(%d)\n", ntohs(id));
#endif
for (qp = qhead; qp!=QINFO_NULL; qp = qp->q_link) {
if (qp->q_nsid == id)
return(qp);
}
#ifdef DEBUG
if (debug >= 5)
fprintf(ddt,"qp not found\n");
#endif
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) {
#ifdef DEBUG
if (debug >= 5)
fprintf(ddt,"qnew: calloc error\n");
#endif
syslog(LOG_ERR, "forw: %m");
exit(12);
}
#ifdef DEBUG
if (debug >= 5)
fprintf(ddt,"qnew(x%x)\n", qp);
#endif
qp->q_link = qhead;
qhead = qp;
return( qp );
}
void
qfree(qp)
struct qinfo *qp;
{
register struct qinfo *np;
#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);
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);
}