1 /*
2  * lib/krb5/krb/addr_order.c
3  *
4  * Copyright 1990 by the Massachusetts Institute of Technology.
5  * All Rights Reserved.
6  *
7  * Export of this software from the United States of America may
8  *   require a specific license from the United States Government.
9  *   It is the responsibility of any person or organization contemplating
10  *   export to obtain such a license before exporting.
11  *
12  * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
13  * distribute this software and its documentation for any purpose and
14  * without fee is hereby granted, provided that the above copyright
15  * notice appear in all copies and that both that copyright notice and
16  * this permission notice appear in supporting documentation, and that
17  * the name of M.I.T. not be used in advertising or publicity pertaining
18  * to distribution of the software without specific, written prior
19  * permission.  Furthermore if you modify this software you must label
20  * your software as modified software and not distribute it in such a
21  * fashion that it might be confused with the original M.I.T. software.
22  * M.I.T. makes no representations about the suitability of
23  * this software for any purpose.  It is provided "as is" without express
24  * or implied warranty.
25  *
26  *
27  * krb5_address_order()
28  */
29 
30 #include "k5-int.h"
31 
32 #ifndef min
33 #define min(a,b) ((a) < (b) ? (a) : (b))
34 #endif
35 
36 /*
37  * Return an ordering on two addresses:  0 if the same,
38  * < 0 if first is less than 2nd, > 0 if first is greater than 2nd.
39  */
40 /*ARGSUSED*/
41 int KRB5_CALLCONV
krb5_address_order(krb5_context context,const krb5_address * addr1,const krb5_address * addr2)42 krb5_address_order(krb5_context context, const krb5_address *addr1, const krb5_address *addr2)
43 {
44     int dir;
45     register int i;
46     const int minlen = min(addr1->length, addr2->length);
47 
48     if (addr1->addrtype != addr2->addrtype)
49 	return(FALSE);
50 
51     dir = addr1->length - addr2->length;
52 
53 
54     for (i = 0; i < minlen; i++) {
55 	if ((unsigned char) addr1->contents[i] <
56 	    (unsigned char) addr2->contents[i])
57 	    return -1;
58 	else if ((unsigned char) addr1->contents[i] >
59 		 (unsigned char) addr2->contents[i])
60 	    return 1;
61     }
62     /* compared equal so far...which is longer? */
63     return dir;
64 }
65