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BSD 4_3_Net_1 release
[unix-history] / named / ns_resp.c
/*
* Copyright (c) 1986, 1988 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley. The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#ifndef lint
static char sccsid[] = "@(#)ns_resp.c 4.55 (Berkeley) 1/14/89";
#endif /* not lint */
#include <stdio.h>
#include <sys/param.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <sys/file.h>
#include <netinet/in.h>
#include <syslog.h>
#include <arpa/nameser.h>
#include "ns.h"
#include "db.h"
extern int debug;
extern FILE *ddt;
extern int errno;
extern u_char *dnptrs[];
extern time_t retrytime();
extern struct fwdinfo *fwdtab;
extern struct sockaddr_in from_addr; /* Source addr of last packet */
extern int needs_prime_cache;
extern int priming;
struct qinfo *sysquery();
ns_resp(msg, msglen)
u_char *msg;
int msglen;
{
register struct qinfo *qp;
register HEADER *hp;
register struct qserv *qs;
register struct databuf *ns, *ns2;
register u_char *cp;
struct databuf *nsp[NSMAX], **nspp;
int i, c, n, ancount, aucount, nscount, arcount;
int type, class, dbflags;
int cname = 0; /* flag for processing cname response */
int count, founddata, foundname;
int buflen;
int newmsglen;
char name[MAXDNAME], *dname;
char *fname;
u_char newmsg[BUFSIZ];
u_char **dpp, *tp;
time_t rtrip;
struct hashbuf *htp;
struct namebuf *np;
struct netinfo *lp;
extern struct netinfo *local();
extern int nsid;
extern int addcount;
#ifdef STATS
stats[S_RESPONSES].cnt++;
#endif
hp = (HEADER *) msg;
if ((qp = qfindid(hp->id)) == NULL ) {
#ifdef DEBUG
if (debug > 1)
fprintf(ddt,"DUP? dropped (id %d)\n", ntohs(hp->id));
#endif
#ifdef STATS
stats[S_DUPRESP].cnt++;
#endif
return;
}
#ifdef DEBUG
if (debug >= 2)
fprintf(ddt,"%s response nsid=%d id=%d\n",
qp->q_system ? "SYSTEM" : "USER",
ntohs(qp->q_nsid), ntohs(qp->q_id));
#endif
/*
* Here we handle bad responses from servers.
* Several possibilities come to mind:
* The server is sick and returns SERVFAIL
* The server returns some garbage opcode (its sick)
* The server can't understand our query and return FORMERR
* In all these cases, we simply drop the packet and force
* a retry. This will make him look bad due to unresponsiveness.
* Be sure not to include authoritative NXDOMAIN
*/
if ((hp->rcode != NOERROR && hp->rcode != NXDOMAIN)
|| (hp->rcode == NXDOMAIN && !hp->aa)
|| hp->opcode != QUERY) {
#ifdef DEBUG
if (debug >= 2)
fprintf(ddt,"resp: error (ret %d, op %d), dropped\n",
hp->rcode, hp->opcode);
#endif
#ifdef STATS
stats[S_BADRESPONSES].cnt++;
#endif
return;
}
#ifdef ALLOW_UPDATES
if ( (hp->rcode == NOERROR) &&
(hp->opcode == UPDATEA || hp->opcode == UPDATED ||
hp->opcode == UPDATEDA || hp->opcode == UPDATEM ||
hp->opcode == UPDATEMA) ) {
/*
* Update the secondary's copy, now that the primary
* successfully completed the update. Zone doesn't matter
* for dyn. update -- doupdate calls findzone to find it
*/
doupdate(qp->q_msg, qp->q_msglen, qp->q_msg + sizeof(HEADER),
0, (struct databuf *)0, 0);
#ifdef DEBUG
if (debug >= 3)
fprintf(ddt,"resp: leaving, UPDATE*\n");
#endif
/* return code filled in by doupdate */
goto return_msg;
}
#endif ALLOW_UPDATES
/*
* If we were using nameservers, find the qinfo pointer and update
* the rtt and fact that we have called on this server before.
*/
if (qp->q_fwd == (struct fwdinfo *)0) {
struct timeval *stp;
for (n = 0, qs = qp->q_addr; n < qp->q_naddr; n++, qs++)
if (bcmp((char *)&qs->ns_addr.sin_addr,
&from_addr.sin_addr, sizeof(struct in_addr)) == 0)
break;
if (n >= qp->q_naddr) {
#ifdef DEBUG
if (debug)
fprintf(ddt, "Response from unexpected source %s\n",
inet_ntoa(from_addr.sin_addr));
#endif DEBUG
#ifdef STATS
stats[S_MARTIANS].cnt++;
#endif
/* assume response to have come from last query */
qs = &qp->q_addr[qp->q_curaddr];
}
stp = &qs->stime;
/* Handle response from different (untried) interface */
if (stp->tv_sec == 0) {
ns = qs->ns;
while (qs > qp->q_addr &&
(qs->stime.tv_sec == 0 || qs->ns != ns))
qs--;
*stp = qs->stime;
#ifdef DEBUG
if (debug)
fprintf(ddt,
"Response from unused address %s, assuming %s\n",
inet_ntoa(from_addr.sin_addr),
inet_ntoa(qs->ns_addr.sin_addr));
#endif DEBUG
}
/* compute query round trip time */
rtrip = ((tt.tv_sec - stp->tv_sec) * 1000 +
(tt.tv_usec - stp->tv_usec) / 1000);
#ifdef DEBUG
if (debug > 2)
fprintf(ddt,"stime %d/%d now %d/%d rtt %d\n",
stp->tv_sec, stp->tv_usec,
tt.tv_sec, tt.tv_usec, rtrip);
#endif
/* prevent floating point overflow, limit to 1000 sec */
if (rtrip > 1000000)
rtrip = 1000000;
ns = qs->nsdata;
/*
* Don't update nstime if this doesn't look
* like an address databuf now. XXX
*/
if (ns->d_type == T_A && ns->d_class == qs->ns->d_class) {
if (ns->d_nstime == 0)
ns->d_nstime = (u_long)rtrip;
else
ns->d_nstime = ns->d_nstime * ALPHA +
(1-ALPHA) * (u_long)rtrip;
/* prevent floating point overflow, limit to 1000 sec */
if (ns->d_nstime > 1000000)
ns->d_nstime = 1000000;
}
/*
* Record the source so that we do not use this NS again.
*/
if(qp->q_nusedns < NSMAX) {
qp->q_usedns[qp->q_nusedns++] = qs->ns;
#ifdef DEBUG
if(debug > 1)
fprintf(ddt, "NS #%d addr %s used, rtt %d\n",
n, inet_ntoa(qs->ns_addr.sin_addr),
ns->d_nstime);
#endif DEBUG
}
/*
* Penalize those who had earlier chances but failed
* by multiplying round-trip times by BETA (>1).
* Improve nstime for unused addresses by applying GAMMA.
* The GAMMA factor makes unused entries slowly
* improve, so they eventually get tried again.
* GAMMA should be slightly less than 1.
* Watch out for records that may have timed out
* and are no longer the correct type. XXX
*/
for (n = 0, qs = qp->q_addr; n < qp->q_naddr; n++, qs++) {
ns2 = qs->nsdata;
if (ns2 == ns)
continue;
if (ns2->d_type != T_A ||
ns2->d_class != qs->ns->d_class) /* XXX */
continue;
if (qs->stime.tv_sec) {
if (ns2->d_nstime == 0)
ns2->d_nstime = rtrip * BETA;
else
ns2->d_nstime =
ns2->d_nstime * BETA + (1-ALPHA) * rtrip;
if (ns2->d_nstime > 1000000)
ns2->d_nstime = 1000000;
} else
ns2->d_nstime = ns2->d_nstime * GAMMA;
#ifdef DEBUG
if(debug > 1)
fprintf(ddt, "NS #%d %s rtt now %d\n", n,
inet_ntoa(qs->ns_addr.sin_addr),
ns2->d_nstime);
#endif DEBUG
}
}
/*
* Skip query section
*/
addcount = 0;
cp = msg + sizeof(HEADER);
dpp = dnptrs;
*dpp++ = msg;
if ((*cp & INDIR_MASK) == 0)
*dpp++ = cp;
*dpp = NULL;
if (hp->qdcount) {
n = dn_skipname(cp, msg + msglen);
if (n <= 0)
goto formerr;
cp += n;
GETSHORT(type, cp);
GETSHORT(class, cp);
if (cp - msg > msglen)
goto formerr;
}
/*
* Save answers, authority, and additional records for future use.
*/
ancount = ntohs(hp->ancount);
aucount = ntohs(hp->nscount);
arcount = ntohs(hp->arcount);
nscount = 0;
tp = cp;
#ifdef DEBUG
if (debug >= 3)
fprintf(ddt,"resp: ancount %d, aucount %d, arcount %d\n",
ancount, aucount, arcount);
#endif
/*
* If there's an answer, check if it's a CNAME response;
* if no answer but aucount > 0, see if there is an NS
* or just an SOA. (NOTE: ancount might be 1 with a CNAME,
* and NS records may still be in the authority section;
* we don't bother counting them, as we only use nscount
* if ancount == 0.)
*/
if (ancount == 1 || (ancount == 0 && aucount > 0)) {
c = aucount;
do {
if (tp - msg >= msglen)
goto formerr;
n = dn_skipname(tp, msg + msglen);
if (n <= 0)
goto formerr;
tp += n; /* name */
GETSHORT(i, tp); /* type */
tp += sizeof(u_short); /* class */
tp += sizeof(u_long); /* ttl */
GETSHORT(count, tp); /* dlen */
if (tp - msg > msglen - count)
goto formerr;
tp += count;
if (ancount && i == T_CNAME) {
cname++;
#ifdef DEBUG
if (debug)
fprintf(ddt,"CNAME - needs more processing\n");
#endif
if (!qp->q_cmsglen) {
qp->q_cmsg = qp->q_msg;
qp->q_cmsglen = qp->q_msglen;
qp->q_msg = NULL;
qp->q_msglen = 0;
}
}
/*
* See if authority record is a nameserver.
*/
if (ancount == 0 && i == T_NS)
nscount++;
} while (--c > 0);
tp = cp;
}
/*
* Add the info received in the response to the Data Base
*/
c = ancount + aucount + arcount;
#ifdef notdef
/*
* If the request was for a CNAME that doesn't exist,
* but the name is valid, fetch any other data for the name.
* DON'T do this now, as it will requery if data are already
* in the cache (maybe later with negative caching).
*/
if (hp->qdcount && type == T_CNAME && c == 0 && hp->rcode == NOERROR &&
!qp->q_system) {
#ifdef DEBUG
if (debug >= 3)
fprintf(ddt,"resp: leaving, no CNAME\n");
#endif
/* Cause us to put it in the cache later */
prime(class, T_ANY, qp);
/* Nothing to store, just give user the answer */
goto return_msg;
}
#endif /* notdef */
nspp = nsp;
if (qp->q_system)
dbflags = DB_NOTAUTH | DB_NODATA;
else
dbflags = DB_NOTAUTH | DB_NODATA | DB_NOHINTS;
for (i = 0; i < c; i++) {
struct databuf *ns3;
if (cp >= msg + msglen)
goto formerr;
ns3 = 0;
if ((n = doupdate(msg, msglen, cp, 0, &ns3, dbflags)) < 0) {
#ifdef DEBUG
if (debug)
fprintf(ddt,"resp: leaving, doupdate failed\n");
#endif
/* return code filled in by doupdate */
goto return_msg;
}
/*
* Remember nameservers from the authority section
* for referrals.
* (This is usually overwritten by findns below(?). XXX
*/
if (ns3 && i >= ancount && i < ancount + aucount &&
nspp < &nsp[NSMAX-1])
*nspp++ = ns3;
cp += n;
}
if (qp->q_system && ancount) {
if (qp->q_system == PRIMING_CACHE)
check_root();
#ifdef DEBUG
if (debug > 2)
fprintf(ddt,"resp: leaving, SYSQUERY ancount %d\n", ancount);
#endif
qremove(qp);
return;
}
if (cp > msg + msglen)
goto formerr;
/*
* If there are addresses and this is a local query,
* sort them appropriately for the local context.
*/
if (ancount > 1 && (lp = local(&qp->q_from)) != NULL)
sort_response(tp, ancount, lp, msg + msglen);
/*
* An answer to a C_ANY query or a successful answer to a
* regular query with no indirection, then just return answer.
*/
if ((type == C_ANY && ancount) ||
(!cname && !qp->q_cmsglen && ancount)) {
#ifdef DEBUG
if (debug >= 3)
fprintf(ddt,"resp: got as much answer as there is\n");
#endif
goto return_msg;
}
/*
* Eventually we will want to cache this negative answer.
*/
if (ancount == 0 && nscount == 0 &&
(hp->aa || qp->q_fwd || class == C_ANY)) {
/* We have an authoritative NO */
#ifdef DEBUG
if (debug >= 3)
fprintf(ddt,"resp: leaving auth NO\n");
#endif
if (qp->q_cmsglen) {
msg = (u_char *)qp->q_cmsg;
msglen = qp->q_cmsglen;
hp = (HEADER *)msg;
}
goto return_msg;
}
/*
* All messages in here need further processing. i.e. they
* are either CNAMEs or we got referred again.
*/
count = 0;
founddata = 0;
foundname = 0;
dname = name;
if (!cname && qp->q_cmsglen && ancount) {
#ifdef DEBUG
if (debug)
fprintf(ddt,"Cname second pass\n");
#endif
newmsglen = qp->q_cmsglen;
bcopy(qp->q_cmsg, newmsg, newmsglen);
} else {
newmsglen = msglen;
bcopy(msg, newmsg, newmsglen);
}
hp = (HEADER *) newmsg;
hp->ancount = 0;
hp->nscount = 0;
hp->arcount = 0;
dnptrs[0] = newmsg;
dnptrs[1] = NULL;
cp = newmsg + sizeof(HEADER);
if (cname)
cp += dn_skipname(cp, newmsg + newmsglen) + QFIXEDSZ;
if ((n = dn_expand(newmsg, newmsg + newmsglen,
cp, dname, sizeof(name))) < 0) {
#ifdef DEBUG
if (debug)
fprintf(ddt,"dn_expand failed\n" );
#endif
goto servfail;
}
cp = newmsg + sizeof(HEADER) +
(cname ? dn_skipname(cp, newmsg + newmsglen) : n) + QFIXEDSZ;
buflen = sizeof(newmsg) - (cp - newmsg);
try_again:
#ifdef DEBUG
if (debug)
fprintf(ddt,"resp: nlookup(%s) type=%d\n",dname, type);
#endif
fname = "";
htp = hashtab; /* lookup relative to root */
np = nlookup(dname, &htp, &fname, 0);
#ifdef DEBUG
if (debug)
fprintf(ddt,"resp: %s '%s' as '%s' (cname=%d)\n",
np == NULL ? "missed" : "found", dname, fname, cname);
#endif
if (np == NULL || fname != dname)
goto fetch_ns;
foundname++;
count = cp - newmsg;
n = finddata(np, class, type, hp, &dname, &buflen, &count);
if (n == 0)
goto fetch_ns; /* NO data available */
cp += n;
buflen -= n;
hp->ancount += count;
if (fname != dname && type != T_CNAME && type != T_ANY) {
cname++;
goto try_again;
}
founddata = 1;
#ifdef DEBUG
if (debug >= 3) {
fprintf(ddt,"resp: foundname = %d count = %d ", foundname, count);
fprintf(ddt,"founddata = %d cname = %d\n", founddata, cname);
}
#endif
fetch_ns:
hp->ancount = htons(hp->ancount);
/*
* Look for name servers to refer to and fill in the authority
* section or record the address for forwarding the query
* (recursion desired).
*/
switch (findns(&np, class, nsp, &count)) {
case NXDOMAIN: /* shouldn't happen */
#ifdef DEBUG
if (debug >= 3)
fprintf(ddt,"req: leaving (%s, rcode %d)\n",
dname, hp->rcode);
#endif
if (!foundname)
hp->rcode = NXDOMAIN;
if (class != C_ANY) {
hp->aa = 1;
/*
* should return SOA if founddata == 0,
* but old named's are confused by an SOA
* in the auth. section if there's no error.
*/
if (foundname == 0 && np) {
n = doaddauth(hp, cp, buflen, np, nsp[0]);
cp += n;
buflen -= n;
}
}
goto return_newmsg;
case SERVFAIL:
goto servfail;
}
if (founddata) {
hp = (HEADER *)newmsg;
n = add_data(np, nsp, cp, buflen);
if (n < 0) {
hp->tc = 1;
n = (-n);
}
cp += n;
buflen -= n;
hp->nscount = htons((u_short)count);
goto return_newmsg;
}
/*
* If we get here, we don't have the answer yet and are about
* to iterate to try and get it. First, infinite loop avoidance.
*/
if (qp->q_nqueries++ > MAXQUERIES) {
#ifdef DEBUG
if (debug)
fprintf(ddt,"resp: MAXQUERIES exceeded (%s, class %d, type %d)\n",
dname, class, type);
#endif
syslog(LOG_NOTICE,
"MAXQUERIES exceeded, possible data loop in resolving (%s)",
dname);
goto servfail;
}
/* Reset the query control structure */
qp->q_naddr = 0;
qp->q_curaddr = 0;
qp->q_fwd = fwdtab;
qp->q_addr[0].stime = tt;
if (nslookup(nsp, qp) == 0) {
#ifdef DEBUG
if (debug >= 3)
fprintf(ddt,"resp: no addrs found for NS's\n");
#endif
goto servfail;
}
if (cname) {
if (qp->q_cname++ == MAXCNAMES) {
#ifdef DEBUG
if (debug >= 3)
fprintf(ddt,"resp: leaving, MAXCNAMES exceeded\n");
#endif
goto servfail;
}
#ifdef DEBUG
if (debug)
fprintf(ddt,"q_cname = %d\n",qp->q_cname);
if (debug >= 3)
fprintf(ddt,"resp: building recursive query; nslookup\n");
#endif
if (qp->q_msg)
(void) free(qp->q_msg);
if ((qp->q_msg = malloc(BUFSIZ)) == NULL) {
#ifdef DEBUG
if (debug)
fprintf(ddt,"resp: malloc error\n");
#endif
goto servfail;
}
qp->q_msglen = res_mkquery(QUERY, dname, class,
type, (char *)NULL, 0, NULL, qp->q_msg, BUFSIZ);
hp = (HEADER *) qp->q_msg;
hp->rd = 0;
} else
hp = (HEADER *)qp->q_msg;
hp->id = qp->q_nsid = htons((u_short)++nsid);
unsched(qp);
schedretry(qp, retrytime(qp));
#ifdef DEBUG
if (debug)
fprintf(ddt,"resp: forw -> %s %d (%d) nsid=%d id=%d %dms\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->d_nstime);
if ( debug >= 10)
fp_query(msg, ddt);
#endif
if (sendto(ds, qp->q_msg, qp->q_msglen, 0,
(struct sockaddr *)Q_NEXTADDR(qp,0),
sizeof(struct sockaddr_in)) < 0) {
#ifdef DEBUG
if (debug >= 5)
fprintf(ddt, "sendto error = %d\n", errno);
#endif
}
#ifdef STATS
stats[S_OUTPKTS].cnt++;
#endif
#ifdef DEBUG
if (debug >= 3)
fprintf(ddt,"resp: Query sent.\n");
#endif
return;
formerr:
#ifdef DEBUG
if (debug)
fprintf(ddt,"FORMERR resp() from %s size err %d, msglen %d\n",
inet_ntoa(from_addr.sin_addr),
cp-msg, msglen);
#endif
syslog(LOG_INFO, "Malformed response from %s\n",
inet_ntoa(from_addr.sin_addr));
#ifdef STATS
stats[S_RESPFORMERR].cnt++;
#endif
return;
return_msg:
#ifdef STATS
stats[S_RESPOK].cnt++;
#endif
/* The "standard" return code */
hp->qr = 1;
hp->id = qp->q_id;
hp->rd = 1;
hp->ra = 1;
(void) send_msg(msg, msglen, qp);
qremove(qp);
return;
return_newmsg:
#ifdef STATS
stats[S_RESPOK].cnt++;
#endif
if (addcount) {
n = doaddinfo(hp, cp, buflen);
cp += n;
buflen -= n;
}
hp->id = qp->q_id;
hp->rd = 1;
hp->ra = 1;
hp->qr = 1;
(void) send_msg(newmsg, cp - newmsg, qp);
qremove(qp);
return;
servfail:
#ifdef STATS
stats[S_RESPFAIL].cnt++;
#endif
hp = (HEADER *)(cname ? qp->q_cmsg : qp->q_msg);
hp->rcode = SERVFAIL;
hp->id = qp->q_id;
hp->rd = 1;
hp->ra = 1;
hp->qr = 1;
(void) send_msg((char *)hp, (cname ? qp->q_cmsglen : qp->q_msglen), qp);
qremove(qp);
return;
}
/*
* Decode the resource record 'rrp' and update the database.
* If savens is true, record pointer for forwarding queries a second time.
*/
doupdate(msg, msglen, rrp, zone, savens, flags)
char *msg ;
u_char *rrp;
struct databuf **savens;
int msglen, zone, flags;
{
register u_char *cp;
register int n;
int class, type, dlen, n1;
u_long ttl;
struct databuf *dp;
char dname[MAXDNAME];
u_char *cp1;
u_char data[BUFSIZ];
register HEADER *hp = (HEADER *) msg;
#ifdef DEBUG
if (debug > 2)
fprintf(ddt,"doupdate(zone %d, savens %x, flags %x)\n",
zone, savens, flags);
#endif
cp = rrp;
if ((n = dn_expand(msg, msg + msglen, cp, dname, sizeof(dname))) < 0) {
hp->rcode = FORMERR;
return (-1);
}
cp += n;
GETSHORT(type, cp);
GETSHORT(class, cp);
GETLONG(ttl, cp);
GETSHORT(dlen, cp);
#ifdef DEBUG
if (debug > 2)
fprintf(ddt,"doupdate: dname %s type %d class %d ttl %d\n",
dname, type, class, ttl);
#endif
/*
* Convert the resource record data into the internal
* database format.
*/
switch (type) {
case T_A:
case T_WKS:
case T_HINFO:
case T_UINFO:
case T_UID:
case T_GID:
#ifdef ALLOW_T_UNSPEC
case T_UNSPEC:
#endif ALLOW_T_UNSPEC
cp1 = cp;
n = dlen;
cp += n;
break;
case T_CNAME:
case T_MB:
case T_MG:
case T_MR:
case T_NS:
case T_PTR:
if ((n = dn_expand(msg, msg + msglen, cp, data,
sizeof(data))) < 0) {
hp->rcode = FORMERR;
return (-1);
}
cp += n;
cp1 = data;
n = strlen(data) + 1;
break;
case T_MINFO:
case T_SOA:
if ((n = dn_expand(msg, msg + msglen, cp, data,
sizeof(data))) < 0) {
hp->rcode = FORMERR;
return (-1);
}
cp += n;
cp1 = data + (n = strlen(data) + 1);
n1 = sizeof(data) - n;
if (type == T_SOA)
n1 -= 5 * sizeof(u_long);
if ((n = dn_expand(msg, msg + msglen, cp, cp1, n1)) < 0) {
hp->rcode = FORMERR;
return (-1);
}
cp += n;
cp1 += strlen(cp1) + 1;
if (type == T_SOA) {
bcopy(cp, cp1, n = 5 * sizeof(u_long));
cp += n;
cp1 += n;
}
n = cp1 - data;
cp1 = data;
break;
case T_MX:
/* grab preference */
bcopy(cp,data,sizeof(u_short));
cp1 = data + sizeof(u_short);
cp += sizeof(u_short);
/* get name */
if ((n = dn_expand(msg, msg + msglen, cp, cp1,
sizeof(data)-sizeof(u_short))) < 0)
return(-1);
cp += n;
/* compute end of data */
cp1 += strlen(cp1) + 1;
/* compute size of data */
n = cp1 - data;
cp1 = data;
break;
default:
#ifdef DEBUG
if (debug >= 3)
fprintf(ddt,"unknown type %d\n", type);
#endif
return ((cp - rrp) + dlen);
}
if (n > MAXDATA) {
#ifdef DEBUG
if (debug)
fprintf(ddt,
"update type %d: %d bytes is too much data\n",
type, n);
#endif
hp->rcode = NOCHANGE; /* XXX - FORMERR ??? */
return(-1);
}
#ifdef ALLOW_UPDATES
/*
* If this is a dynamic update request, process it specially; else,
* execute normal update code.
*/
switch(opcode) {
/* For UPDATEM and UPDATEMA, do UPDATED/UPDATEDA followed by UPDATEA */
case UPDATEM:
case UPDATEMA:
/*
* The named code for UPDATED and UPDATEDA is the same except that for
* UPDATEDA we we ignore any data that was passed: we just delete all
* RRs whose name, type, and class matches
*/
case UPDATED:
case UPDATEDA:
if (type == T_SOA) { /* Not allowed */
#ifdef DEBUG
if (debug)
fprintf(ddt, "UDPATE: REFUSED - SOA delete\n");
#endif
hp->rcode = REFUSED;
return(-1);
}
/*
* Don't check message length if doing UPDATEM/UPDATEMA,
* since the whole message wont have been demarshalled until
* we reach the code for UPDATEA
*/
if ( (opcode == UPDATED) || (opcode == UPDATEDA) ) {
if (cp != msg + msglen) {
#ifdef DEBUG
if (debug)
fprintf(ddt,"FORMERR UPDATE message length off\n");
#endif
hp->rcode = FORMERR;
return(-1);
}
}
if ((zonenum = findzone(dname, class)) == 0) {
hp->rcode = NXDOMAIN;
return(-1);
}
if ( (opcode == UPDATED) || (opcode == UPDATEM) ) {
/* Make a dp for use in db_update, as old dp */
dp = savedata(class, type, 0, cp1, n);
dp->d_zone = zonenum;
n = db_update(dname, dp, NULL, DB_MEXIST | DB_DELETE,
hashtab);
if (n != OK) {
#ifdef DEBUG
if (debug)
fprintf(ddt,"UPDATE: db_update failed\n");
#endif DEBUG
free( (struct databuf *) dp);
hp->rcode = NOCHANGE;
return(-1);
}
} else { /* UPDATEDA or UPDATEMA */
int DeletedOne = 0;
/* Make a dp for use in db_update, as old dp */
dp = savedata(class, type, 0, NULL, 0);
dp->d_zone = zonenum;
do { /* Loop and delete all matching RR(s) */
n = db_update(dname, dp, NULL, DB_DELETE,
hashtab);
if (n != OK)
break;
DeletedOne++;
} while (1);
free( (struct databuf *) dp);
/* Ok for UPDATEMA not to have deleted any RRs */
if (!DeletedOne && opcode == UPDATEDA) {
#ifdef DEBUG
if (debug)
fprintf(ddt,"UPDATE: db_update failed\n");
#endif DEBUG
hp->rcode = NOCHANGE;
return(-1);
}
}
if ( (opcode == UPDATED) || (opcode == UPDATEDA) )
return (cp - rrp);;
/*
* Else unmarshal the RR to be added and continue on to
* UPDATEA code for UPDATEM/UPDATEMA
*/
if ((n =
dn_expand(msg, msg+msglen, cp, dname, sizeof(dname))) < 0) {
#ifdef DEBUG
if (debug)
fprintf(ddt,"FORMERR UPDATE expand name failed\n");
#endif
hp->rcode = FORMERR;
return(-1);
}
cp += n;
GETSHORT(type, cp);
GETSHORT(class, cp);
GETLONG(ttl, cp);
GETSHORT(n, cp);
cp1 = cp;
/**** XXX - need bounds checking here ****/
cp += n;
case UPDATEA:
if (n > MAXDATA) {
#ifdef DEBUG
if (debug)
fprintf(ddt,"UPDATE: too much data\n");
#endif
hp->rcode = NOCHANGE;
return(-1);
}
if (cp != msg + msglen) {
#ifdef DEBUG
if (debug)
fprintf(ddt,"FORMERR UPDATE message length off\n");
#endif
hp->rcode = FORMERR;
return(-1);
}
if ((zonenum = findzone(dname, class)) == 0) {
hp->rcode = NXDOMAIN;
return(-1);
}
dp = savedata(class, type, ttl, cp1, n);
dp->d_zone = zonenum;
if ((n = db_update(dname, NULL, dp, DB_NODATA,
hashtab)) != OK) {
#ifdef DEBUG
if (debug)
fprintf(ddt,"UPDATE: db_update failed\n");
#endif
hp->rcode = NOCHANGE;
return (-1);
}
else
return (cp - rrp);
}
#endif ALLOW_UPDATES
if (zone == 0)
ttl += tt.tv_sec;
dp = savedata(class, type, ttl, cp1, n);
dp->d_zone = zone;
if ((n = db_update(dname, dp, dp, flags, hashtab)) < 0) {
#ifdef DEBUG
if (debug && (n != DATAEXISTS))
fprintf(ddt,"update failed (%d)\n", n);
else if (debug >= 3)
fprintf(ddt,"update failed (DATAEXISTS)\n");
#endif
(void) free((char *)dp);
} else if (type == T_NS && savens != NULL)
*savens = dp;
return (cp - rrp);
}
send_msg(msg, msglen, qp)
char *msg;
int msglen;
struct qinfo *qp;
{
extern struct qinfo *qhead;
#ifdef DEBUG
struct qinfo *tqp;
#endif DEBUG
if (qp->q_system)
return(1);
#ifdef DEBUG
if (debug) {
fprintf(ddt,"send_msg -> %s (%s %d %d) id=%d\n",
inet_ntoa(qp->q_from.sin_addr),
qp->q_stream == QSTREAM_NULL ? "UDP" : "TCP", qp->q_dfd,
ntohs(qp->q_from.sin_port),
ntohs(qp->q_id));
}
if (debug>4)
for (tqp = qhead; tqp!=QINFO_NULL; tqp = tqp->q_link) {
fprintf(ddt, "qp %x q_id: %d q_nsid: %d q_msglen: %d ",
tqp, tqp->q_id,tqp->q_nsid,tqp->q_msglen);
fprintf(ddt,"q_naddr: %d q_curaddr: %d\n", tqp->q_naddr,
tqp->q_curaddr);
fprintf(ddt,"q_next: %x q_link: %x\n", qp->q_next,
qp->q_link);
}
if (debug >= 10)
fp_query(msg, ddt);
#endif DEBUG
if (qp->q_stream == QSTREAM_NULL) {
if (sendto(qp->q_dfd, msg, msglen, 0,
(struct sockaddr *)&qp->q_from, sizeof(qp->q_from)) < 0) {
#ifdef DEBUG
if (debug)
fprintf(ddt, "sendto error errno= %d\n",errno);
#endif
return(1);
}
#ifdef STATS
stats[S_OUTPKTS].cnt++;
#endif
} else {
(void) writemsg(qp->q_stream->s_rfd, msg, msglen);
qp->q_stream->s_time = tt.tv_sec;
qp->q_stream->s_refcnt--;
}
return(0);
}
prime(class, type, oqp)
int class, type;
register struct qinfo *oqp;
{
char dname[BUFSIZ];
if (oqp->q_msg == NULL)
return;
if (dn_expand(oqp->q_msg, oqp->q_msg + oqp->q_msglen,
oqp->q_msg + sizeof(HEADER), dname, sizeof(dname)) < 0)
return;
#ifdef DEBUG
if (debug >= 2)
fprintf(ddt,"prime: %s\n", dname);
#endif
(void) sysquery(dname, class, type);
}
prime_cache()
{
register struct qinfo *qp;
#ifdef DEBUG
if (debug)
fprintf(ddt,"prime_cache: priming = %d\n", priming);
#endif
#ifdef STATS
stats[S_PRIMECACHE].cnt++;
#endif
if (!priming && fcachetab->h_tab[0] != NULL && !forward_only) {
priming++;
if ((qp = sysquery("", C_IN, T_NS)) == NULL)
priming = 0;
else
qp->q_system = PRIMING_CACHE;
}
needs_prime_cache = 0;
return;
}
struct qinfo *
sysquery(dname, class, type)
char *dname;
int class, type;
{
extern struct qinfo *qhead;
extern int nsid;
register struct qinfo *qp, *oqp;
register HEADER *hp;
struct namebuf *np;
struct databuf *nsp[NSMAX];
struct hashbuf *htp;
char *fname;
int count;
#ifdef DEBUG
if (debug > 2)
fprintf(ddt,"sysquery(%s, %d, %d)\n", dname, class, type);
#endif
#ifdef STATS
stats[S_SYSQUERIES].cnt++;
#endif
htp = hashtab;
if (priming && dname[0] == '\0')
np = NULL;
else if ((np = nlookup(dname, &htp, &fname, 1)) == NULL) {
#ifdef DEBUG
if (debug)
fprintf(ddt,"sysquery: nlookup error on %s?\n", dname);
#endif
return(0);
}
switch (findns(&np, class, nsp, &count)) {
case NXDOMAIN:
case SERVFAIL:
#ifdef DEBUG
if (debug)
fprintf(ddt,"sysquery: findns error on %s?\n", dname);
#endif
return(0);
}
/* build new qinfo struct */
qp = qnew();
qp->q_cmsg = qp->q_msg = NULL;
qp->q_dfd = ds;
qp->q_fwd = fwdtab;
qp->q_addr[0].stime = tt;
qp->q_system++;
if ((qp->q_msg = malloc(BUFSIZ)) == NULL) {
qfree(qp);
return(0);
}
qp->q_msglen = res_mkquery(QUERY, dname, class,
type, (char *)NULL, 0, NULL, qp->q_msg, BUFSIZ);
hp = (HEADER *) qp->q_msg;
hp->id = qp->q_nsid = htons((u_short)++nsid);
hp->rd = (qp->q_fwd ? 1 : 0);
/* First check for an already pending query for this data */
for (oqp = qhead; oqp!=QINFO_NULL; oqp = oqp->q_link) {
if (oqp != qp && oqp->q_msglen == qp->q_msglen &&
bcmp((char *)oqp->q_msg+2, qp->q_msg+2, qp->q_msglen-2) == 0) {
#ifdef DEBUG
if (debug >= 3)
fprintf(ddt, "sysquery: duplicate\n");
#endif
qfree(qp);
return(0);
}
}
if (nslookup(nsp, qp) == 0) {
#ifdef DEBUG
if (debug)
fprintf(ddt,"resp: no addrs found for NS's\n");
#endif
qfree(qp);
return(0);
}
schedretry(qp, retrytime(qp));
if (qp->q_fwd == 0)
qp->q_addr[0].stime = tt;
#ifdef DEBUG
if (debug)
fprintf(ddt,"sysquery: send -> %s %d (%d), nsid=%d id=%d %dms\n",
inet_ntoa(Q_NEXTADDR(qp,0)->sin_addr),
qp->q_dfd, ntohs(Q_NEXTADDR(qp,0)->sin_port),
ntohs(qp->q_nsid), ntohs(qp->q_id),
qp->q_addr[0].nsdata->d_nstime);
if ( debug >= 10)
fp_query(qp->q_msg, ddt);
#endif
if (sendto(qp->q_dfd, qp->q_msg, qp->q_msglen, 0,
(struct sockaddr *)Q_NEXTADDR(qp,0),
sizeof(struct sockaddr_in)) < 0){
#ifdef DEBUG
if (debug)
fprintf(ddt, "sendto error errno= %d\n",errno);
#endif
}
#ifdef STATS
stats[S_OUTPKTS].cnt++;
#endif
return(qp);
}
/*
* Check the list of root servers after receiving a response
* to a query for the root servers.
*/
check_root()
{
register struct databuf *dp, *pdp;
register struct namebuf *np;
int count = 0;
priming = 0;
for (np = hashtab->h_tab[0]; np != NULL; np = np->n_next)
if (np->n_dname[0] == '\0')
break;
if (np == NULL) {
syslog(LOG_ERR, "check_root: Can't find root!\n");
return;
}
for (dp = np->n_data; dp != NULL; dp = dp->d_next)
if (dp->d_type == T_NS)
count++;
#ifdef DEBUG
if (debug)
fprintf(ddt,"%d root servers\n", count);
#endif
if (count < MINROOTS) {
syslog(LOG_WARNING,
"check_root: %d root servers after query to root server < min",
count);
return;
}
pdp = NULL;
dp = np->n_data;
while (dp != NULL) {
if (dp->d_type == T_NS && dp->d_zone == 0 &&
dp->d_ttl < tt.tv_sec) {
#ifdef DEBUG
if (debug)
fprintf(ddt,"deleting old root server '%s'\n",
dp->d_data);
#endif
dp = rm_datum(dp, np, pdp);
/* SHOULD DELETE FROM HINTS ALSO */
continue;
}
pdp = dp;
dp = dp->d_next;
}
check_ns();
}
/*
* Check the root to make sure that for each NS record we have a A RR
*/
check_ns()
{
register struct databuf *dp, *tdp;
register struct namebuf *np, *tnp;
struct hashbuf *htp;
char *dname;
int found_arr;
char *fname;
time_t curtime;
#ifdef DEBUG
if (debug >= 2)
fprintf(ddt,"check_ns()\n");
#endif
#ifdef STATS
stats[S_CHECKNS].cnt++;
#endif
curtime = (u_long) tt.tv_sec;
for (np = hashtab->h_tab[0]; np != NULL; np = np->n_next) {
if (np->n_dname[0] != 0)
continue;
for (dp = np->n_data; dp != NULL; dp = dp->d_next) {
if (dp->d_type != T_NS)
continue;
/* look for A records */
dname = dp->d_data;
htp = hashtab;
tnp = nlookup(dname, &htp, &fname, 0);
if (tnp == NULL || fname != dname) {
#ifdef DEBUG
if (debug >= 3)
fprintf(ddt,"check_ns: %s: not found %s %x\n",
dname, fname, tnp);
#endif
(void) sysquery(dname, dp->d_class, T_A);
continue;
}
/* look for name server addresses */
found_arr = 0;
for (tdp=tnp->n_data; tdp!=NULL; tdp=tdp->d_next) {
if (tdp->d_type != T_A ||
tdp->d_class != dp->d_class)
continue;
if ((tdp->d_zone == 0) &&
(tdp->d_ttl < curtime)) {
#ifdef DEBUG
if (debug >= 3)
fprintf(ddt,"check_ns: stale entry '%s'\n",
tnp->n_dname);
#endif
/* Cache invalidate the address RR's */
delete_all(tnp, dp->d_class, T_A);
found_arr = 0;
break;
}
found_arr++;
}
if (!found_arr)
(void) sysquery(dname, dp->d_class, T_A);
}
}
}
#define MAXCLASS 255 /* belongs elsewhere */
int norootlogged[MAXCLASS];
/*
* Find NS's or an SOA for the given dname (np) and fill in the
* nsp array. Returns OK on success, and SERVFAIL on error.
* We return NXDOMAIN to indicate we are authoritative.
*/
findns(npp, class, nsp, countp)
register struct namebuf **npp;
struct databuf **nsp;
int *countp;
{
register struct namebuf *np = *npp;
register struct databuf *dp;
register struct databuf **nspp;
struct hashbuf *htp = hashtab;
if (priming && (np == NULL || np->n_dname[0] == '\0'))
htp = fcachetab;
try_again:
if (htp == fcachetab)
needs_prime_cache = 1;
while (np == NULL && htp != NULL) {
#ifdef DEBUG
if (debug > 2)
fprintf(ddt, "findns: using %s\n", htp == hashtab ?
"cache" : "hints");
#endif
for (np = htp->h_tab[0]; np != NULL; np = np->n_next)
if (np->n_dname[0] == '\0')
break;
htp = (htp == hashtab ? fcachetab : NULL); /* Fallback */
}
while(np != NULL) {
#ifdef DEBUG
if (debug >= 5)
fprintf(ddt, "findns: np 0x%x\n", np);
#endif
/* Look first for SOA records. */
for (dp = np->n_data; dp != NULL; dp = dp->d_next) {
if (dp->d_zone != 0 && match(dp, class, T_SOA)) {
#ifdef DEBUG
if (debug >= 3)
fprintf(ddt,"findns: SOA found\n");
#endif
if (zones[dp->d_zone].z_auth) {
*npp = np;
nsp[0] = dp;
return(NXDOMAIN);
} else
return (SERVFAIL);
}
}
/* If no SOA records, look for NS records. */
nspp = &nsp[0];
*nspp = NULL;
for (dp = np->n_data; dp != NULL; dp = dp->d_next) {
if (dp->d_type != T_NS ||
(dp->d_class != class && class != C_ANY))
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 < (tt.tv_sec+900)) &&
!(dp->d_flags & DB_F_HINT)) {
#ifdef DEBUG
if (debug)
fprintf(ddt,"findns: stale entry '%s'\n",
np->n_dname);
#endif
/* Cache invalidate the NS RR's */
if (dp->d_ttl < tt.tv_sec)
delete_all(np, class, T_NS);
goto try_parent;
}
if (nspp < &nsp[NSMAX-1])
*nspp++ = dp;
}
*countp = nspp - nsp;
if (*countp > 0) {
#ifdef DEBUG
if (debug >= 3)
fprintf(ddt,"findns: %d NS's added for '%s'\n",
*countp, np->n_dname);
#endif
*nspp = NULL;
*npp = np;
return(OK); /* Success, got some NS's */
}
try_parent:
np = np->n_parent;
}
if (htp)
goto try_again;
#ifdef DEBUG
if (debug)
fprintf(ddt, "findns: No root nameservers for class %d?\n",
class);
#endif
if ((unsigned)class < MAXCLASS && norootlogged[class] == 0) {
norootlogged[class] = 1;
syslog(LOG_ERR, "No root nameservers for class %d\n", class);
}
return(SERVFAIL);
}
/*
* Extract RR's from the given node that match class and type.
* Return number of bytes added to response.
* If no matching data is found, then 0 is returned.
*/
finddata(np, class, type, hp, dnamep, lenp, countp)
struct namebuf *np;
int class, type;
register HEADER *hp;
char **dnamep;
int *lenp, *countp;
{
register struct databuf *dp;
register char *cp;
int buflen, n, count = 0, foundstale = 0;
buflen = *lenp;
cp = ((char *)hp) + *countp;
for (dp = np->n_data; dp != NULL; dp = dp->d_next) {
if (!wanted(dp, class, type)) {
if (type == T_CNAME && class == dp->d_class) {
/* any data means no CNAME exists */
*countp = 0;
return(0);
}
continue;
}
if (stale(dp)) {
/*
* Don't use stale data.
* Would like to call delete_all here
* and continue, but the data chain would get
* munged; can't restart, as make_rr has side
* effects (leaving pointers in dnptr).
* Just skip this entry for now
* and call delete_all at the end.
*/
#ifdef DEBUG
if (debug >=3)
fprintf(ddt,"finddata: stale entry '%s'\n",np->n_dname);
#endif
if (dp->d_zone == 0)
foundstale++;
continue;
}
if ((n = make_rr(*dnamep, dp, cp, buflen, 1)) < 0) {
hp->tc = 1;
*countp = count;
return(*lenp - buflen);
}
cp += n;
buflen -= n;
count++;
#ifdef notdef
/* this isn't right for glue records, aa is set in ns_req */
if (dp->d_zone && zones[dp->d_zone].z_auth && class != C_ANY)
hp->aa = 1; /* XXX */
#endif
if (dp->d_type == T_CNAME) {
if (type != T_ANY) { /* or T_NS? */
*dnamep = dp->d_data;
if (dp->d_zone && zones[dp->d_zone].z_auth &&
class != C_ANY) /* XXX */
hp->aa = 1; /* XXX */
}
break;
}
}
/*
* Cache invalidate the other RR's of same type
* if some have timed out
*/
if (foundstale)
delete_all(np, class, type);
#ifdef DEBUG
if (debug >=3)
fprintf(ddt,"finddata: added %d class %d type %d RRs\n",
count, class, type);
#endif
*countp = count;
return(*lenp - buflen);
}
/*
* Do we want this data record based on the class and type?
*/
wanted(dp, class, type)
struct databuf *dp;
int class, type;
{
#ifdef DEBUG
if (debug > 3)
fprintf(ddt,"wanted(%x, %d, %d) %d, %d\n", dp, class, type,
dp->d_class, dp->d_type);
#endif
if (dp->d_class != class && class != C_ANY)
return (0);
if (type == dp->d_type)
return (1);
switch (dp->d_type) {
case T_ANY:
case T_CNAME:
return (1);
}
switch (type) {
case T_ANY:
return (1);
case T_MAILB:
switch (dp->d_type) {
case T_MR:
case T_MB:
case T_MG:
case T_MINFO:
return (1);
}
break;
case T_AXFR:
if (dp->d_type == T_SOA)
return (1);
}
return (0);
}
/*
* Add RR entries from dpp array to a query/response.
* Return the number of bytes added or negative the amount
* added if truncation was required. Typically you are
* adding NS records to a response.
*/
add_data(np, dpp, cp, buflen)
struct namebuf *np;
struct databuf **dpp;
register char *cp;
int buflen;
{
register struct databuf *dp;
char dname[MAXDNAME];
register int n, count = 0;
getname(np, dname, sizeof(dname));
for(dp = *dpp++; dp != NULL; dp = *dpp++) {
if (stale(dp))
continue; /* ignore old cache entry */
if ((n = make_rr(dname, dp, cp, buflen, 1)) < 0)
return(-count); /* Truncation */
cp += n;
buflen -= n;
count += n;
}
return(count);
}
/*
* This is best thought of as a "cache invalidate" function.
* It is called whenever a piece of data is determined to have
* timed out. It is better to have no information, than to
* have partial information you pass off as complete.
*/
delete_all(np, class, type)
register struct namebuf *np;
int class, type;
{
register struct databuf *dp, *pdp;
#ifdef DEBUG
if (debug > 2)
fprintf(ddt,"delete_all: '%s' 0x%x class %d type %d\n",
np->n_dname, np, class, type);
#endif
pdp = NULL;
dp = np->n_data;
while (dp != NULL) {
if ((dp->d_zone == 0) && !(dp->d_flags & DB_F_HINT)
&& match(dp, class, type)) {
dp = rm_datum(dp, np, pdp);
continue;
}
pdp = dp;
dp = dp->d_next;
}
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.