1 /*
2 * Copyright (c) 1986, 1990 Regents of the University of California.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 #ifndef lint
35 static char sccsid[] = "@(#)ns_sort.c 4.10 (Berkeley) 3/3/91";
36 #endif /* not lint */
37
38 #include <stdio.h>
39 #include <sys/types.h>
40 #include <sys/time.h>
41 #include <sys/socket.h>
42 #include <sys/file.h>
43 #include <netinet/in.h>
44 #include <syslog.h>
45 #include <arpa/nameser.h>
46 #include <resolv.h>
47 #include "ns.h"
48 #include "db.h"
49
50 extern int debug;
51 extern FILE *ddt;
52
53 struct netinfo*
local(from)54 local(from)
55 struct sockaddr_in *from;
56 {
57 extern struct netinfo *nettab, netloop, **enettab;
58 struct netinfo *ntp;
59
60 if (from->sin_addr.s_addr == netloop.my_addr.s_addr)
61 return( &netloop);
62 for (ntp = nettab; ntp != *enettab; ntp = ntp->next) {
63 if (ntp->net == (from->sin_addr.s_addr & ntp->mask))
64 return(ntp);
65 }
66 return(NULL);
67 }
68
69
sort_response(cp,ancount,lp,eom)70 sort_response(cp, ancount, lp, eom)
71 register char *cp;
72 register int ancount;
73 struct netinfo *lp;
74 u_char *eom;
75 {
76 register struct netinfo *ntp;
77 extern struct netinfo *nettab;
78
79 #ifdef DEBUG
80 if (debug > 2)
81 fprintf(ddt,"sort_response(%d)\n", ancount);
82 #endif DEBUG
83 if (ancount > 1) {
84 if (sort_rr(cp, ancount, lp, eom))
85 return;
86 for (ntp = nettab; ntp != NULL; ntp = ntp->next) {
87 if ((ntp->net == lp->net) && (ntp->mask == lp->mask))
88 continue;
89 if (sort_rr(cp, ancount, ntp, eom))
90 break;
91 }
92 }
93 }
94
95 int
sort_rr(cp,count,ntp,eom)96 sort_rr(cp, count, ntp, eom)
97 register u_char *cp;
98 int count;
99 register struct netinfo *ntp;
100 u_char *eom;
101 {
102 int type, class, dlen, n, c;
103 struct in_addr inaddr;
104 u_char *rr1;
105
106 #ifdef DEBUG
107 if (debug > 2) {
108 inaddr.s_addr = ntp->net;
109 fprintf(ddt,"sort_rr( x%x, %d, %s)\n",cp, count,
110 inet_ntoa(inaddr));
111 }
112 #endif DEBUG
113 rr1 = NULL;
114 for (c = count; c > 0; --c) {
115 n = dn_skipname(cp, eom);
116 if (n < 0)
117 return (1); /* bogus, stop processing */
118 cp += n;
119 if (cp + QFIXEDSZ > eom)
120 return (1);
121 GETSHORT(type, cp);
122 GETSHORT(class, cp);
123 cp += sizeof(u_long);
124 GETSHORT(dlen, cp);
125 if (dlen > eom - cp)
126 return (1); /* bogus, stop processing */
127 switch (type) {
128 case T_A:
129 switch (class) {
130 case C_IN:
131 case C_HS:
132 bcopy(cp, (char *)&inaddr, sizeof(inaddr));
133 if (rr1 == NULL)
134 rr1 = cp;
135 if ((ntp->mask & inaddr.s_addr) == ntp->net) {
136 #ifdef DEBUG
137 if (debug > 1) {
138 fprintf(ddt,"net %s best choice\n",
139 inet_ntoa(inaddr));
140 }
141 #endif DEBUG
142 if (rr1 != cp) {
143 bcopy(rr1, cp, sizeof(inaddr));
144 bcopy((char *)&inaddr, rr1, sizeof(inaddr));
145 }
146 return(1);
147 }
148 break;
149 }
150 break;
151 }
152 cp += dlen;
153 }
154 return(0);
155 }
156