FreeBSD-5.3/lib/libc/net/res_update.c
/*
* Copyright (c) 1996 by Internet Software Consortium.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
* ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
* CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
* SOFTWARE.
*/
/*
* Based on the Dynamic DNS reference implementation by Viraj Bais
* <viraj_bais@ccm.fm.intel.com>
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/lib/libc/net/res_update.c,v 1.7 2002/09/15 16:51:09 nectar Exp $");
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>
#include <limits.h>
#include <netdb.h>
#include <resolv.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
/*
* Separate a linked list of records into groups so that all records
* in a group will belong to a single zone on the nameserver.
* Create a dynamic update packet for each zone and send it to the
* nameservers for that zone, and await answer.
* Abort if error occurs in updating any zone.
* Return the number of zones updated on success, < 0 on error.
*
* On error, caller must deal with the unsynchronized zones
* eg. an A record might have been successfully added to the forward
* zone but the corresponding PTR record would be missing if error
* was encountered while updating the reverse zone.
*/
#define NSMAX 16
struct ns1 {
char nsname[MAXDNAME];
struct in_addr nsaddr1;
};
struct zonegrp {
char z_origin[MAXDNAME];
int16_t z_class;
char z_soardata[MAXDNAME + 5 * INT32SZ];
struct ns1 z_ns[NSMAX];
int z_nscount;
ns_updrec * z_rr;
struct zonegrp *z_next;
};
int
res_update(ns_updrec *rrecp_in) {
ns_updrec *rrecp, *tmprrecp;
u_char buf[PACKETSZ], answer[PACKETSZ], packet[2*PACKETSZ];
char name[MAXDNAME], zname[MAXDNAME], primary[MAXDNAME],
mailaddr[MAXDNAME];
u_char soardata[2*MAXCDNAME+5*INT32SZ];
char *dname, *svdname, *cp1, *target;
u_char *cp, *eom;
HEADER *hp = (HEADER *) answer;
struct zonegrp *zptr = NULL, *tmpzptr, *prevzptr, *zgrp_start = NULL;
int i, j, k = 0, n, ancount, nscount, arcount, rcode, rdatasize,
newgroup, done, myzone, seen_before, numzones = 0;
u_int16_t dlen, class, qclass, type, qtype;
u_int32_t ttl;
if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
h_errno = NETDB_INTERNAL;
return (-1);
}
for (rrecp = rrecp_in; rrecp; rrecp = rrecp->r_next) {
dname = rrecp->r_dname;
n = strlen(dname);
if (dname[n-1] == '.')
dname[n-1] = '\0';
qtype = T_SOA;
qclass = rrecp->r_class;
done = 0;
seen_before = 0;
while (!done && dname) {
if (qtype == T_SOA) {
for (tmpzptr = zgrp_start;
tmpzptr && !seen_before;
tmpzptr = tmpzptr->z_next) {
if (strcasecmp(dname,
tmpzptr->z_origin) == 0 &&
tmpzptr->z_class == qclass)
seen_before++;
for (tmprrecp = tmpzptr->z_rr;
tmprrecp && !seen_before;
tmprrecp = tmprrecp->r_grpnext)
if (strcasecmp(dname, tmprrecp->r_dname) == 0
&& tmprrecp->r_class == qclass) {
seen_before++;
break;
}
if (seen_before) {
/*
* Append to the end of
* current group.
*/
for (tmprrecp = tmpzptr->z_rr;
tmprrecp->r_grpnext;
tmprrecp = tmprrecp->r_grpnext)
(void)NULL;
tmprrecp->r_grpnext = rrecp;
rrecp->r_grpnext = NULL;
done = 1;
break;
}
}
} else if (qtype == T_A) {
for (tmpzptr = zgrp_start;
tmpzptr && !done;
tmpzptr = tmpzptr->z_next)
for (i = 0; i < tmpzptr->z_nscount; i++)
if (tmpzptr->z_class == qclass &&
strcasecmp(tmpzptr->z_ns[i].nsname,
dname) == 0 &&
tmpzptr->z_ns[i].nsaddr1.s_addr != 0) {
zptr->z_ns[k].nsaddr1.s_addr =
tmpzptr->z_ns[i].nsaddr1.s_addr;
done = 1;
break;
}
}
if (done)
break;
n = res_mkquery(QUERY, dname, qclass, qtype, NULL,
0, NULL, buf, sizeof buf);
if (n <= 0) {
fprintf(stderr, "res_update: mkquery failed\n");
return (n);
}
n = res_send(buf, n, answer, sizeof answer);
if (n < 0) {
fprintf(stderr, "res_update: send error for %s\n",
rrecp->r_dname);
return (n);
} else if (n > sizeof(answer)) {
fprintf(stderr, "res_update: buffer too small\n");
return (-1);
}
if (n < HFIXEDSZ)
return (-1);
ancount = ntohs(hp->ancount);
nscount = ntohs(hp->nscount);
arcount = ntohs(hp->arcount);
rcode = hp->rcode;
cp = answer + HFIXEDSZ;
eom = answer + n;
/* skip the question section */
n = dn_skipname(cp, eom);
if (n < 0 || cp + n + 2 * INT16SZ > eom)
return (-1);
cp += n + 2 * INT16SZ;
if (qtype == T_SOA) {
if (ancount == 0 && nscount == 0 && arcount == 0) {
/*
* if (rcode == NOERROR) then the dname exists but
* has no soa record associated with it.
* if (rcode == NXDOMAIN) then the dname does not
* exist and the server is replying out of NCACHE.
* in either case, proceed with the next try
*/
dname = strchr(dname, '.');
if (dname != NULL)
dname++;
continue;
} else if ((rcode == NOERROR || rcode == NXDOMAIN) &&
ancount == 0 &&
nscount == 1 && arcount == 0) {
/*
* name/data does not exist, soa record supplied in the
* authority section
*/
/* authority section must contain the soa record */
if ((n = dn_expand(answer, eom, cp, zname,
sizeof zname)) < 0)
return (n);
cp += n;
if (cp + 2 * INT16SZ > eom)
return (-1);
GETSHORT(type, cp);
GETSHORT(class, cp);
if (type != T_SOA || class != qclass) {
fprintf(stderr, "unknown answer\n");
return (-1);
}
myzone = 0;
svdname = dname;
while (dname)
if (strcasecmp(dname, zname) == 0) {
myzone = 1;
break;
} else if ((dname = strchr(dname, '.')) != NULL)
dname++;
if (!myzone) {
dname = strchr(svdname, '.');
if (dname != NULL)
dname++;
continue;
}
nscount = 0;
/* fallthrough */
} else if (rcode == NOERROR && ancount == 1) {
/*
* found the zone name
* new servers will supply NS records for the zone
* in authority section and A records for those
* nameservers in the additional section
* older servers have to be explicitly queried for
* NS records for the zone
*/
/* answer section must contain the soa record */
if ((n = dn_expand(answer, eom, cp, zname,
sizeof zname)) < 0)
return (n);
else
cp += n;
if (cp + 2 * INT16SZ > eom)
return (-1);
GETSHORT(type, cp);
GETSHORT(class, cp);
if (type == T_CNAME) {
dname = strchr(dname, '.');
if (dname != NULL)
dname++;
continue;
}
if (strcasecmp(dname, zname) != 0 ||
type != T_SOA ||
class != rrecp->r_class) {
fprintf(stderr, "unknown answer\n");
return (-1);
}
/* FALLTHROUGH */
} else {
fprintf(stderr,
"unknown response: ans=%d, auth=%d, add=%d, rcode=%d\n",
ancount, nscount, arcount, hp->rcode);
return (-1);
}
if (cp + INT32SZ + INT16SZ > eom)
return (-1);
/* continue processing the soa record */
GETLONG(ttl, cp);
GETSHORT(dlen, cp);
if (cp + dlen > eom)
return (-1);
newgroup = 1;
zptr = zgrp_start;
prevzptr = NULL;
while (zptr) {
if (strcasecmp(zname, zptr->z_origin) == 0 &&
type == T_SOA && class == qclass) {
newgroup = 0;
break;
}
prevzptr = zptr;
zptr = zptr->z_next;
}
if (!newgroup) {
for (tmprrecp = zptr->z_rr;
tmprrecp->r_grpnext;
tmprrecp = tmprrecp->r_grpnext)
;
tmprrecp->r_grpnext = rrecp;
rrecp->r_grpnext = NULL;
done = 1;
cp += dlen;
break;
} else {
if ((n = dn_expand(answer, eom, cp, primary,
sizeof primary)) < 0)
return (n);
cp += n;
/*
* We don't have to bounds check here because the
* next use of 'cp' is in dn_expand().
*/
cp1 = (char *)soardata;
strcpy(cp1, primary);
cp1 += strlen(cp1) + 1;
if ((n = dn_expand(answer, eom, cp, mailaddr,
sizeof mailaddr)) < 0)
return (n);
cp += n;
strcpy(cp1, mailaddr);
cp1 += strlen(cp1) + 1;
if (cp + 5*INT32SZ > eom)
return (-1);
memcpy(cp1, cp, 5*INT32SZ);
cp += 5*INT32SZ;
cp1 += 5*INT32SZ;
rdatasize = (u_char *)cp1 - soardata;
zptr = calloc(1, sizeof(struct zonegrp));
if (zptr == NULL)
return (-1);
if (zgrp_start == NULL)
zgrp_start = zptr;
else
prevzptr->z_next = zptr;
zptr->z_rr = rrecp;
rrecp->r_grpnext = NULL;
strcpy(zptr->z_origin, zname);
zptr->z_class = class;
memcpy(zptr->z_soardata, soardata, rdatasize);
/* fallthrough to process NS and A records */
}
} else if (qtype == T_NS) {
if (rcode == NOERROR && ancount > 0) {
strcpy(zname, dname);
for (zptr = zgrp_start; zptr; zptr = zptr->z_next) {
if (strcasecmp(zname, zptr->z_origin) == 0)
break;
}
if (zptr == NULL)
/* should not happen */
return (-1);
if (nscount > 0) {
/*
* answer and authority sections contain
* the same information, skip answer section
*/
for (j = 0; j < ancount; j++) {
n = dn_skipname(cp, eom);
if (n < 0)
return (-1);
n += 2*INT16SZ + INT32SZ;
if (cp + n + INT16SZ > eom)
return (-1);
cp += n;
GETSHORT(dlen, cp);
cp += dlen;
}
} else
nscount = ancount;
/* fallthrough to process NS and A records */
} else {
fprintf(stderr, "cannot determine nameservers for %s:\
ans=%d, auth=%d, add=%d, rcode=%d\n",
dname, ancount, nscount, arcount, hp->rcode);
return (-1);
}
} else if (qtype == T_A) {
if (rcode == NOERROR && ancount > 0) {
arcount = ancount;
ancount = nscount = 0;
/* fallthrough to process A records */
} else {
fprintf(stderr, "cannot determine address for %s:\
ans=%d, auth=%d, add=%d, rcode=%d\n",
dname, ancount, nscount, arcount, hp->rcode);
return (-1);
}
}
/* process NS records for the zone */
j = 0;
for (i = 0; i < nscount; i++) {
if ((n = dn_expand(answer, eom, cp, name,
sizeof name)) < 0)
return (n);
cp += n;
if (cp + 3 * INT16SZ + INT32SZ > eom)
return (-1);
GETSHORT(type, cp);
GETSHORT(class, cp);
GETLONG(ttl, cp);
GETSHORT(dlen, cp);
if (cp + dlen > eom)
return (-1);
if (strcasecmp(name, zname) == 0 &&
type == T_NS && class == qclass) {
if ((n = dn_expand(answer, eom, cp,
name, sizeof name)) < 0)
return (n);
target = zptr->z_ns[j++].nsname;
strcpy(target, name);
}
cp += dlen;
}
if (zptr->z_nscount == 0)
zptr->z_nscount = j;
/* get addresses for the nameservers */
for (i = 0; i < arcount; i++) {
if ((n = dn_expand(answer, eom, cp, name,
sizeof name)) < 0)
return (n);
cp += n;
if (cp + 3 * INT16SZ + INT32SZ > eom)
return (-1);
GETSHORT(type, cp);
GETSHORT(class, cp);
GETLONG(ttl, cp);
GETSHORT(dlen, cp);
if (cp + dlen > eom)
return (-1);
if (type == T_A && dlen == INT32SZ && class == qclass) {
for (j = 0; j < zptr->z_nscount; j++)
if (strcasecmp(name, zptr->z_ns[j].nsname) == 0) {
memcpy(&zptr->z_ns[j].nsaddr1.s_addr, cp,
INT32SZ);
break;
}
}
cp += dlen;
}
if (zptr->z_nscount == 0) {
dname = zname;
qtype = T_NS;
continue;
}
done = 1;
for (k = 0; k < zptr->z_nscount; k++)
if (zptr->z_ns[k].nsaddr1.s_addr == 0) {
done = 0;
dname = zptr->z_ns[k].nsname;
qtype = T_A;
}
} /* while */
}
_res.options |= RES_DEBUG;
for (zptr = zgrp_start; zptr; zptr = zptr->z_next) {
/* append zone section */
rrecp = res_mkupdrec(ns_s_zn, zptr->z_origin,
zptr->z_class, ns_t_soa, 0);
if (rrecp == NULL) {
fprintf(stderr, "saverrec error\n");
fflush(stderr);
return (-1);
}
rrecp->r_grpnext = zptr->z_rr;
zptr->z_rr = rrecp;
n = res_mkupdate(zptr->z_rr, packet, sizeof packet);
if (n < 0) {
fprintf(stderr, "res_mkupdate error\n");
fflush(stderr);
return (-1);
} else
fprintf(stdout, "res_mkupdate: packet size = %d\n", n);
/*
* Override the list of NS records from res_init() with
* the authoritative nameservers for the zone being updated.
* Sort primary to be the first in the list of nameservers.
*/
for (i = 0; i < zptr->z_nscount; i++) {
if (strcasecmp(zptr->z_ns[i].nsname,
zptr->z_soardata) == 0) {
struct in_addr tmpaddr;
if (i != 0) {
strcpy(zptr->z_ns[i].nsname,
zptr->z_ns[0].nsname);
strcpy(zptr->z_ns[0].nsname,
zptr->z_soardata);
tmpaddr = zptr->z_ns[i].nsaddr1;
zptr->z_ns[i].nsaddr1 =
zptr->z_ns[0].nsaddr1;
zptr->z_ns[0].nsaddr1 = tmpaddr;
}
break;
}
}
for (i = 0; i < MAXNS; i++) {
_res.nsaddr_list[i].sin_addr = zptr->z_ns[i].nsaddr1;
_res.nsaddr_list[i].sin_family = AF_INET;
_res.nsaddr_list[i].sin_port = htons(NAMESERVER_PORT);
}
_res.nscount = (zptr->z_nscount < MAXNS) ?
zptr->z_nscount : MAXNS;
n = res_send(packet, n, answer, sizeof(answer));
if (n < 0) {
fprintf(stderr, "res_send: send error, n=%d\n", n);
break;
} else if (n > sizeof(answer)) {
fprintf(stderr, "res_send: buffer too small\n");
break;
}
numzones++;
}
/* free malloc'ed memory */
while(zgrp_start) {
zptr = zgrp_start;
zgrp_start = zgrp_start->z_next;
res_freeupdrec(zptr->z_rr); /* Zone section we allocated. */
free((char *)zptr);
}
return (numzones);
}