414 lines
13 KiB
C
414 lines
13 KiB
C
/* $NetBSD: ns_sort.c,v 1.3 2001/01/27 07:22:00 itojun Exp $ */
|
|
|
|
#if !defined(lint) && !defined(SABER)
|
|
static const char sccsid[] = "@(#)ns_sort.c 4.10 (Berkeley) 3/3/91";
|
|
static const char rcsid[] = "Id: ns_sort.c,v 8.6 2000/04/21 06:54:13 vixie Exp";
|
|
#endif /* not lint */
|
|
|
|
/*
|
|
* Copyright (c) 1986, 1990
|
|
* The Regents of the University of California. All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. All advertising materials mentioning features or use of this software
|
|
* must display the following acknowledgement:
|
|
* This product includes software developed by the University of
|
|
* California, Berkeley and its contributors.
|
|
* 4. Neither the name of the University nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*/
|
|
|
|
/*
|
|
* Portions Copyright (c) 1993 by Digital Equipment Corporation.
|
|
*
|
|
* Permission to use, copy, modify, and distribute this software for any
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
* copyright notice and this permission notice appear in all copies, and that
|
|
* the name of Digital Equipment Corporation not be used in advertising or
|
|
* publicity pertaining to distribution of the document or software without
|
|
* specific, written prior permission.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
|
|
* WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
|
|
* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
|
|
* CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
|
|
* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
|
|
* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
|
|
* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
|
|
* SOFTWARE.
|
|
*/
|
|
|
|
/*
|
|
* Portions Copyright (c) 1996-2000 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.
|
|
*/
|
|
|
|
/*
|
|
* Sorting should really be handled by the resolver, but:
|
|
* 1) There are too many brain dead resolvers out there that can't be replaced.
|
|
* 2) It would be a pain to individually configure all those resolvers anyway.
|
|
*
|
|
* Here's the scoop:
|
|
*
|
|
* To enable address sorting in responses, you need to supply the sortlist
|
|
* statement in the config file. The sortlist statement takes an
|
|
* address match list and interprets it even more specially than the
|
|
* topology statement does.
|
|
*
|
|
* Each top level statement in the sortlist must itself be an explicit
|
|
* address match list with one or two elements. The first element
|
|
* (which may be an IP address, an IP prefix, an ACL name or nested
|
|
* address match list) of each top level list is checked against the
|
|
* source address of the query until a match is found.
|
|
*
|
|
* Once the source address of the query has been matched, if the top level
|
|
* statement contains only one element, the actual primitive element that
|
|
* matched the source address is used to select the address in the response
|
|
* to move to the beginning of the response. If the statement is a list
|
|
* of two elements, then the second element is treated like the address
|
|
* match list in a topology statement. Each top level element is assigned
|
|
* a distance and the address in the response with the minimum distance is
|
|
* moved to the beginning of the response.
|
|
*
|
|
* In the following example, any queries received from any of the addresses
|
|
* of the host itself will get responses preferring addresses on any of
|
|
* the locally connected networks. Next most preferred are addresses on
|
|
* the 192.168.1/24 network, and after that either the 192.168.2/24 or
|
|
* 192.168.3/24 network with no preference shown between these two networks.
|
|
* Queries received from a host on the 192.168.1/24 network will prefer
|
|
* other addresses on that network to the 192.168.2/24 and 192.168.3/24
|
|
* networks. Queries received from a host on the 192.168.4/24 or the
|
|
* 192.168.5/24 network will only prefer other addresses on their
|
|
* directly connected networks.
|
|
*
|
|
* sortlist {
|
|
* {
|
|
* localhost;
|
|
* {
|
|
* localnets;
|
|
* 192.168.1/24;
|
|
* { 192,168.2/24; 192.168.3/24; };
|
|
* };
|
|
* };
|
|
* {
|
|
* 192.168.1/24;
|
|
* {
|
|
* 192.168.1/24;
|
|
* { 192.168.2/24; 192.168.3/24; };
|
|
* };
|
|
* };
|
|
* {
|
|
* 192.168.2/24;
|
|
* {
|
|
* 192.168.2/24;
|
|
* { 192.168.1/24; 192.168.3/24; };
|
|
* };
|
|
* };
|
|
* {
|
|
* 192.168.3/24;
|
|
* {
|
|
* 192.168.3/24;
|
|
* { 192.168.1/24; 192.168.2/24; };
|
|
* };
|
|
* };
|
|
* {
|
|
* { 192.168.4/24; 192.168.5/24; };
|
|
* };
|
|
* };
|
|
*
|
|
*
|
|
* The following example will give reasonable behaviour for the local host
|
|
* and hosts on directly connected networks. It is similar to the behavior
|
|
* of the address sort in BIND 4.9.x. Responses sent to queries from the
|
|
* local host will favor any of the directly connected networks. Responses
|
|
* sent to queries from any other hosts on a directly connected network will
|
|
* prefer addresses on that same network. Responses to other queries will
|
|
* not be sorted.
|
|
*
|
|
* sortlist {
|
|
* { localhost; localnets; };
|
|
* { localnets; };
|
|
* };
|
|
*
|
|
* XXX - it wouldb e nice to have an ACL called "source" that matched the
|
|
* source address of a query so that a host could be configured to
|
|
* automatically prefer itself, and an ACL called "sourcenet", that
|
|
* would return the primitive IP match element that matched the source
|
|
* address so that you could do:
|
|
* { localnets; { sourcenet; { other stuff ...}; };
|
|
* and automatically get similar behaviour to what you get with:
|
|
* { localnets; };
|
|
*
|
|
*/
|
|
|
|
#include "port_before.h"
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/types.h>
|
|
#include <sys/socket.h>
|
|
#include <sys/file.h>
|
|
#include <netinet/in.h>
|
|
#include <arpa/nameser.h>
|
|
#include <arpa/inet.h>
|
|
#include <stdio.h>
|
|
#include <syslog.h>
|
|
#include <resolv.h>
|
|
#include <string.h>
|
|
|
|
#include <isc/eventlib.h>
|
|
#include <isc/logging.h>
|
|
|
|
#include "port_after.h"
|
|
|
|
#include "named.h"
|
|
|
|
static int sort_rr(u_char *cp, u_char *eom, int ancount, ip_match_list iml);
|
|
|
|
static int ip_match_address_elt(ip_match_list, struct in_addr,
|
|
ip_match_element *);
|
|
|
|
void
|
|
sort_response(u_char *cp, u_char *eom, int ancount, struct sockaddr_in *from) {
|
|
struct in_addr address;
|
|
struct ip_match_element imelement;
|
|
ip_match_element imetl, imematch, imeprimitive;
|
|
struct ip_match_list imlist;
|
|
ip_match_list iml;
|
|
int indirect, matched;
|
|
|
|
if (server_options->sortlist == NULL)
|
|
return;
|
|
|
|
if (from->sin_family != AF_INET)
|
|
return;
|
|
|
|
address = from->sin_addr;
|
|
|
|
for (imetl = server_options->sortlist->first; imetl != NULL;
|
|
imetl = imetl->next) {
|
|
if (imetl->type == ip_match_indirect)
|
|
imematch = imetl->u.indirect.list->first;
|
|
else
|
|
/*
|
|
* allow a bare pattern as a top level statement
|
|
* and treat it like {pattern;};
|
|
*/
|
|
imematch = imetl;
|
|
|
|
switch (imematch->type) {
|
|
case ip_match_pattern:
|
|
indirect = 0;
|
|
break;
|
|
case ip_match_indirect:
|
|
indirect = 1;
|
|
break;
|
|
case ip_match_localhost:
|
|
imematch->u.indirect.list = local_addresses;
|
|
indirect = 1;
|
|
break;
|
|
case ip_match_localnets:
|
|
imematch->u.indirect.list = local_networks;
|
|
indirect = 1;
|
|
break;
|
|
default:
|
|
panic("unexpected ime type in ip_match_address()",
|
|
NULL);
|
|
}
|
|
if (indirect) {
|
|
imeprimitive = NULL;
|
|
matched = ip_match_address_elt(imematch->u.indirect.list,
|
|
address, &imeprimitive);
|
|
if (matched >= 0) {
|
|
if (imematch->flags & IP_MATCH_NEGATE)
|
|
/* Don't sort */
|
|
return;
|
|
} else
|
|
continue;
|
|
} else {
|
|
if (ina_onnet(address, imematch->u.direct.address,
|
|
imematch->u.direct.mask)) {
|
|
if (imematch->flags & IP_MATCH_NEGATE)
|
|
/* Don't sort */
|
|
return;
|
|
else
|
|
imeprimitive = imematch;
|
|
} else
|
|
continue;
|
|
}
|
|
if (imetl != imematch && imematch->next != NULL) {
|
|
/*
|
|
* Not a bare pattern at the top level, but a two
|
|
* element list
|
|
*/
|
|
switch (imematch->next->type) {
|
|
case ip_match_pattern:
|
|
case ip_match_localhost:
|
|
case ip_match_localnets:
|
|
imelement = *(imematch->next);
|
|
imelement.next = NULL;
|
|
iml = &imlist;
|
|
iml->first = iml->last = &imelement;
|
|
break;
|
|
case ip_match_indirect:
|
|
iml = imematch->next->u.indirect.list;
|
|
break;
|
|
default:
|
|
panic("unexpected ime type in ip_match_address()",
|
|
NULL);
|
|
}
|
|
} else if (imeprimitive) {
|
|
imelement = *imeprimitive;
|
|
imelement.next = NULL;
|
|
iml = &imlist;
|
|
iml->first = iml->last = &imelement;
|
|
} else {
|
|
/* Don't sort because we'd just use "any" */
|
|
return;
|
|
}
|
|
sort_rr(cp, eom, ancount, iml);
|
|
break;
|
|
}
|
|
|
|
return;
|
|
}
|
|
|
|
static int
|
|
sort_rr(u_char *cp, u_char *eom, int ancount, ip_match_list iml) {
|
|
int type, class, dlen, n, c, distance, closest;
|
|
struct in_addr inaddr;
|
|
u_char *rr1 = NULL, *rrbest, *cpstart;
|
|
|
|
rr1 = NULL;
|
|
cpstart = cp;
|
|
for (c = ancount; c > 0; --c) {
|
|
n = dn_skipname(cp, eom);
|
|
if (n < 0)
|
|
return (1); /* bogus, stop processing */
|
|
cp += n;
|
|
if (cp + QFIXEDSZ > eom)
|
|
return (1);
|
|
GETSHORT(type, cp);
|
|
GETSHORT(class, cp);
|
|
cp += INT32SZ;
|
|
GETSHORT(dlen, cp);
|
|
if (dlen > eom - cp)
|
|
return (1); /* bogus, stop processing */
|
|
switch (type) {
|
|
case T_A:
|
|
switch (class) {
|
|
case C_IN:
|
|
case C_HS:
|
|
memcpy((char *)&inaddr, cp, INADDRSZ);
|
|
/* Find the address with the minimum distance */
|
|
if (rr1 == NULL) {
|
|
rr1 = cp;
|
|
rrbest = cp;
|
|
closest = distance_of_address(iml, inaddr);
|
|
} else {
|
|
distance = distance_of_address(iml, inaddr);
|
|
if (distance < closest) {
|
|
rrbest = cp;
|
|
closest = distance;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
break;
|
|
}
|
|
cp += dlen;
|
|
}
|
|
if (rr1 != rrbest && rr1 != NULL) {
|
|
memcpy((char *)&inaddr, rrbest, INADDRSZ);
|
|
memcpy(rrbest, rr1, INADDRSZ);
|
|
memcpy(rr1, (char *)&inaddr, INADDRSZ);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Just like ip_match_address(), but also returns a pointer to the primitive
|
|
* element that matched.
|
|
*/
|
|
|
|
static int
|
|
ip_match_address_elt(ip_match_list iml, struct in_addr address,
|
|
ip_match_element *imep) {
|
|
ip_match_element ime;
|
|
int ret;
|
|
int indirect;
|
|
|
|
INSIST(iml != NULL);
|
|
for (ime = iml->first; ime != NULL; ime = ime->next) {
|
|
switch (ime->type) {
|
|
case ip_match_pattern:
|
|
indirect = 0;
|
|
break;
|
|
case ip_match_indirect:
|
|
indirect = 1;
|
|
break;
|
|
case ip_match_localhost:
|
|
ime->u.indirect.list = local_addresses;
|
|
indirect = 1;
|
|
break;
|
|
case ip_match_localnets:
|
|
ime->u.indirect.list = local_networks;
|
|
indirect = 1;
|
|
break;
|
|
default:
|
|
panic("unexpected ime type in ip_match_address()",
|
|
NULL);
|
|
}
|
|
if (indirect) {
|
|
ret = ip_match_address_elt(ime->u.indirect.list,
|
|
address, imep);
|
|
if (ret >= 0) {
|
|
if (ime->flags & IP_MATCH_NEGATE)
|
|
ret = (ret) ? 0 : 1;
|
|
return (ret);
|
|
}
|
|
} else {
|
|
if (ina_onnet(address, ime->u.direct.address,
|
|
ime->u.direct.mask)) {
|
|
*imep = ime;
|
|
if (ime->flags & IP_MATCH_NEGATE)
|
|
return (0);
|
|
else
|
|
return (1);
|
|
}
|
|
}
|
|
}
|
|
return (-1);
|
|
}
|