external/bsd/iscsi/dist/src/lib/netmask.c

   1 /* $NetBSD: netmask.c,v 1.11 2009/01/25 14:25:27 lukem Exp $ */
   2
   3 /*
   4  * Copyright © 2006 Alistair Crooks.  All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 3. The name of the author may not be used to endorse or promote
  15  *    products derived from this software without specific prior written
  16  *    permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
  19  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  20  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
  22  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
  24  * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  25  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  26  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  27  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  28  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  */
  30 #include "config.h"
  31
  32 #include <sys/types.h>
  33 #include <sys/param.h>
  34
  35 #include <stdio.h>
  36 #include <stdlib.h>
  37 #include <string.h>
  38 #include <unistd.h>
  39
  40 #ifdef HAVE_NETINET_IN_H
  41 #include <netinet/in.h>
  42 #endif
  43
  44 #ifdef HAVE_ARPA_INET_H
  45 #include <arpa/inet.h>
  46 #endif
  47
  48 #include "iscsiutil.h"
  49
  50 enum {
  51         NETMASK_BUFFER_SIZE = 256
  52 };
  53
  54 /* this struct is used to define a magic netmask value */
  55 typedef struct magic_t {
  56         const char      *magic; /* string to match */
  57         const char      *xform; /* string to transform it into */
  58 } magic_t;
  59
  60
  61 static magic_t  magics[] = {
  62         {       "any",  "0/0"   },
  63         {       "all",  "0/0"   },
  64         {       "none", "0/32"  },
  65         {       NULL,   NULL    },
  66 };
  67
  68 #ifndef ISCSI_HTONL
  69 #define ISCSI_HTONL(x)  htonl(x)
  70 #endif
  71
  72 /* return 1 if address is in netmask's range */
  73 int
  74 allow_netmask(const char *netmaskarg, const char *addr)
  75 {
  76         struct in_addr   a;
  77         struct in_addr   m;
  78         const char      *netmask;
  79         magic_t         *mp;
  80         char             maskaddr[NETMASK_BUFFER_SIZE];
  81         char            *cp;
  82         int              slash;
  83         int              i;
  84
  85         /* firstly check for any magic values in the netmask */
  86         netmask = netmaskarg;
  87         for (mp = magics ; mp->magic ; mp++) {
  88                 if (strcmp(netmask, mp->magic) == 0) {
  89                         netmask = mp->xform;
  90                         break;
  91                 }
  92         }
  93
  94         /* find out if slash notation has been used */
  95         (void) memset(&a, 0x0, sizeof(a));
  96         if ((cp = strchr(netmask, '/')) == NULL) {
  97                 (void) strlcpy(maskaddr, netmask, sizeof(maskaddr));
  98                 slash = 32;
  99         } else {
 100                 (void) strlcpy(maskaddr, netmask, MIN(sizeof(maskaddr), (size_t)(cp - netmask) + 1));
 101                 slash = atoi(cp + 1);
 102         }
 103
 104         /* if we have a wildcard "slash" netmask, then we allow it */
 105         if (slash == 0) {
 106                 return 1;
 107         }
 108
 109         /* canonicalise IPv4 address to dotted quad */
 110         for (i = 0, cp = maskaddr ; *cp ; cp++) {
 111                 if (*cp == '.') {
 112                         i += 1;
 113                 }
 114         }
 115         for ( ; i < 3 ; i++) {
 116                 (void) snprintf(cp, sizeof(maskaddr) - (int)(cp - maskaddr), ".0");
 117                 cp += 2;
 118         }
 119
 120         /* translate netmask to in_addr */
 121         if (!inet_aton(maskaddr, &m)) {
 122                 (void) fprintf(stderr, "allow_netmask: can't interpret mask `%s' as an IPv4 address\n", maskaddr);
 123                 return 0;
 124         }
 125
 126         /* translate address to in_addr */
 127         if (!inet_aton(addr, &a)) {
 128                 (void) fprintf(stderr, "allow_netmask: can't interpret address `%s' as an IPv4 address\n", addr);
 129                 return 0;
 130         }
 131
 132 #ifdef ALLOW_NETMASK_DEBUG
 133         printf("addr %s %08x, mask %s %08x, slash %d\n", addr, (ISCSI_HTONL(a.s_addr) >> (32 - slash)), maskaddr, (ISCSI_HTONL(m.s_addr) >> (32 - slash)), slash);
 134 #endif
 135
 136         /* and return 1 if address is in netmask */
 137         return (ISCSI_HTONL(a.s_addr) >> (32 - slash)) == (ISCSI_HTONL(m.s_addr) >> (32 - slash));
 138 }
 139
 140 #ifdef ALLOW_NETMASK_DEBUG
 141 int
 142 main(int argc, char **argv)
 143 {
 144         int     i;
 145
 146         for (i = 1 ; i < argc ; i+= 2) {
 147                 if (allow_netmask(argv[i], argv[i + 1])) {
 148                         printf("mask %s matches addr %s\n\n", argv[i], argv[i + 1]);
 149                 } else {
 150                         printf("No match for mask %s from addr %s\n\n", argv[i], argv[i + 1]);
 151                 }
 152         }
 153         exit(EXIT_SUCCESS);
 154 }
 155 #endif
 156
 157 #if 0
 158 [11:33:02] agc@sys3 ...local/src/netmask 248 > ./n 10.4/16 10.4.0.29 10.4/16 10.5.0.29 10.4/0 10.4.0.19 10.4 10.4.0.19 10.4.3/8 10.4.3.7 10.4.3/24 10.4.3.7
 159 mask 10.4/16 matches addr 10.4.0.29
 160
 161 No match for mask 10.4/16 from addr 10.5.0.29
 162
 163 mask 10.4/0 matches addr 10.4.0.19
 164
 165 No match for mask 10.4 from addr 10.4.0.19
 166
 167 mask 10.4.3/8 matches addr 10.4.3.7
 168
 169 mask 10.4.3/24 matches addr 10.4.3.7
 170
 171 [14:44:52] agc@sys3 ...local/src/netmask 249 >
 172 #endif