lib/libipfw3/layer2/ipfw3_layer2.c

   1 /*
   2  * Copyright (c) 2014 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Bill Yuan <bycn82@gmail.com>
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #include <err.h>
  36 #include <errno.h>
  37 #include <stdio.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40 #include <sysexits.h>
  41
  42 #include <net/if.h>
  43 #include <net/route.h>
  44 #include <net/pfil.h>
  45 #include <netinet/in.h>
  46
  47 #include "../../../sys/net/ipfw3/ip_fw3.h"
  48 #include "../../../sbin/ipfw3/ipfw.h"
  49 #include "ipfw3_layer2.h"
  50
  51 /*
  52  * Returns the number of bits set (from left) in a contiguous bitmask,
  53  * or -1 if the mask is not contiguous.
  54  * XXX this needs a proper fix.
  55  * This effectively works on masks in big-endian (network) format.
  56  * when compiled on little endian architectures.
  57  *
  58  * First bit is bit 7 of the first byte -- note, for MAC addresses,
  59  * the first bit on the wire is bit 0 of the first byte.
  60  * len is the max length in bits.
  61  */
  62 static int
  63 contigmask(u_char *p, int len)
  64 {
  65         int i, n;
  66         for (i = 0; i < len ; i++) {
  67                 if ( (p[i/8] & (1 << (7 - (i%8)))) == 0) /* first bit unset */
  68                         break;
  69         }
  70         for (n = i + 1; n < len; n++) {
  71                 if ( (p[n/8] & (1 << (7 - (n%8)))) != 0)
  72                         return -1; /* mask not contiguous */
  73         }
  74         return i;
  75 }
  76
  77 /*
  78  * prints a MAC address/mask pair
  79  */
  80 static void
  81 print_mac(u_char *addr, u_char *mask)
  82 {
  83         int l = contigmask(mask, 48);
  84
  85         if (l == 0) {
  86                 printf(" any");
  87         } else {
  88                 printf(" %02x:%02x:%02x:%02x:%02x:%02x",
  89                         addr[0], addr[1], addr[2], addr[3], addr[4], addr[5]);
  90                 if (l == -1) {
  91                         printf("&%02x:%02x:%02x:%02x:%02x:%02x",
  92                                 mask[0], mask[1], mask[2],
  93                                 mask[3], mask[4], mask[5]);
  94                 } else if (l < 48) {
  95                         printf("/%d", l);
  96                 }
  97         }
  98 }
  99
 100 static void
 101 get_mac_addr_mask(char *p, u_char *addr, u_char *mask)
 102 {
 103         int i, l;
 104
 105         for (i = 0; i < 6; i++)
 106                 addr[i] = mask[i] = 0;
 107         if (!strcmp(p, "any"))
 108                 return;
 109
 110         for (i = 0; *p && i < 6; i++, p++) {
 111                 addr[i] = strtol(p, &p, 16);
 112                 if (*p != ':') /* we start with the mask */
 113                         break;
 114         }
 115         if (*p == '/') { /* mask len */
 116                 l = strtol(p + 1, &p, 0);
 117                 for (i = 0; l > 0; l -= 8, i++)
 118                         mask[i] = (l >=8) ? 0xff : (~0) << (8-l);
 119         } else if (*p == '&') { /* mask */
 120                 for (i = 0, p++; *p && i < 6; i++, p++) {
 121                         mask[i] = strtol(p, &p, 16);
 122                         if (*p != ':')
 123                                 break;
 124                 }
 125         } else if (*p == '\0') {
 126                 for (i = 0; i < 6; i++)
 127                         mask[i] = 0xff;
 128         }
 129         for (i = 0; i < 6; i++)
 130                 addr[i] &= mask[i];
 131 }
 132
 133 void
 134 parse_layer2(ipfw_insn **cmd, int *ac, char **av[])
 135 {
 136         (*cmd)->opcode = O_LAYER2_LAYER2;
 137         (*cmd)->module = MODULE_LAYER2_ID;
 138         (*cmd)->len =  ((*cmd)->len&(F_NOT|F_OR))|LEN_OF_IPFWINSN;
 139         NEXT_ARG1;
 140 }
 141
 142 void
 143 parse_mac(ipfw_insn **cmd, int *ac, char **av[])
 144 {
 145         NEED(*ac, 3, "mac dst src");
 146         NEXT_ARG1;
 147         (*cmd)->opcode = O_LAYER2_MAC;
 148         (*cmd)->module = MODULE_LAYER2_ID;
 149         (*cmd)->len =  ((*cmd)->len&(F_NOT|F_OR))|F_INSN_SIZE(ipfw_insn_mac);
 150         ipfw_insn_mac *mac = (ipfw_insn_mac *)(*cmd);
 151         get_mac_addr_mask(**av, mac->addr, mac->mask);  /* dst */
 152         NEXT_ARG1;
 153         get_mac_addr_mask(**av, &(mac->addr[6]), &(mac->mask[6])); /* src */
 154         NEXT_ARG1;
 155 }
 156
 157 void
 158 show_layer2(ipfw_insn *cmd, int show_or)
 159 {
 160         printf(" layer2");
 161 }
 162
 163 void
 164 show_mac(ipfw_insn *cmd, int show_or)
 165 {
 166         ipfw_insn_mac *m = (ipfw_insn_mac *)cmd;
 167         printf(" mac");
 168         print_mac( m->addr, m->mask);
 169         print_mac( m->addr + 6, m->mask + 6);
 170 }
 171
 172 void
 173 load_module(register_func function, register_keyword keyword)
 174 {
 175         keyword(MODULE_LAYER2_ID, O_LAYER2_LAYER2, "layer2", FILTER);
 176         function(MODULE_LAYER2_ID, O_LAYER2_LAYER2,
 177                         (parser_func)parse_layer2, (shower_func)show_layer2);
 178
 179         keyword(MODULE_LAYER2_ID, O_LAYER2_MAC, "mac", FILTER);
 180         function(MODULE_LAYER2_ID, O_LAYER2_MAC,
 181                         (parser_func)parse_mac,(shower_func)show_mac);
 182 }