xref: /dragonfly/lib/libipfw3/layer2/ipfw3_layer2.c (revision 4408d5485757eef6e44859025e931d1c1b6746c4)
1 /*
2  * Copyright (c) 2014 - 2018 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Bill Yuan <bycn82@dragonflybsd.org>
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 <net/ipfw3/ip_fw3.h>
48 #include "../../../sbin/ipfw3/ipfw3.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
contigmask(u_char * p,int len)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
print_mac(u_char * addr,u_char * mask)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
get_mac_addr_mask(char * p,u_char * addr,u_char * mask)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
parse_layer2(ipfw_insn ** cmd,int * ac,char ** av[])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 |= LEN_OF_IPFWINSN;
139           NEXT_ARG1;
140 }
141 
142 void
parse_mac_from(ipfw_insn ** cmd,int * ac,char ** av[])143 parse_mac_from(ipfw_insn **cmd, int *ac, char **av[])
144 {
145           NEED(*ac, 2, "mac-from src");
146           NEXT_ARG1;
147           if (strcmp(**av, "table") == 0) {
148                     NEED(*ac, 2, "mac-from table N");
149                     NEXT_ARG1;
150                     (*cmd)->opcode = O_LAYER2_MAC_SRC_LOOKUP;
151                     (*cmd)->module = MODULE_LAYER2_ID;
152                     (*cmd)->len |= F_INSN_SIZE(ipfw_insn);
153                     (*cmd)->arg1 = strtoul(**av, NULL, 10);
154                     NEXT_ARG1;
155           } else {
156                     (*cmd)->opcode = O_LAYER2_MAC_SRC;
157                     (*cmd)->module = MODULE_LAYER2_ID;
158                     (*cmd)->len |= F_INSN_SIZE(ipfw_insn_mac);
159                     ipfw_insn_mac *mac = (ipfw_insn_mac *)(*cmd);
160                     /* src */
161                     get_mac_addr_mask(**av, &(mac->addr[6]), &(mac->mask[6]));
162                     NEXT_ARG1;
163           }
164 }
165 
166 void
parse_mac_to(ipfw_insn ** cmd,int * ac,char ** av[])167 parse_mac_to(ipfw_insn **cmd, int *ac, char **av[])
168 {
169           NEED(*ac, 2, "mac-to dst");
170           NEXT_ARG1;
171           if (strcmp(**av, "table") == 0) {
172                     NEED(*ac, 2, "mac-to table N");
173                     NEXT_ARG1;
174                     (*cmd)->opcode = O_LAYER2_MAC_DST_LOOKUP;
175                     (*cmd)->module = MODULE_LAYER2_ID;
176                     (*cmd)->len |= F_INSN_SIZE(ipfw_insn);
177                     (*cmd)->arg1 = strtoul(**av, NULL, 10);
178                     NEXT_ARG1;
179           } else {
180                     (*cmd)->opcode = O_LAYER2_MAC_DST;
181                     (*cmd)->module = MODULE_LAYER2_ID;
182                     (*cmd)->len |= F_INSN_SIZE(ipfw_insn_mac);
183                     ipfw_insn_mac *mac = (ipfw_insn_mac *)(*cmd);
184                     /* dst */
185                     get_mac_addr_mask(**av, mac->addr, mac->mask);
186                     NEXT_ARG1;
187           }
188 }
189 
190 
191 void
parse_mac(ipfw_insn ** cmd,int * ac,char ** av[])192 parse_mac(ipfw_insn **cmd, int *ac, char **av[])
193 {
194           NEED(*ac, 3, "mac dst src");
195           NEXT_ARG1;
196           (*cmd)->opcode = O_LAYER2_MAC;
197           (*cmd)->module = MODULE_LAYER2_ID;
198           (*cmd)->len |= F_INSN_SIZE(ipfw_insn_mac);
199           ipfw_insn_mac *mac = (ipfw_insn_mac *)(*cmd);
200           get_mac_addr_mask(**av, mac->addr, mac->mask);    /* dst */
201           NEXT_ARG1;
202           get_mac_addr_mask(**av, &(mac->addr[6]), &(mac->mask[6])); /* src */
203           NEXT_ARG1;
204 }
205 
206 void
show_layer2(ipfw_insn * cmd,int show_or)207 show_layer2(ipfw_insn *cmd, int show_or)
208 {
209           printf(" layer2");
210 }
211 
212 void
show_mac(ipfw_insn * cmd,int show_or)213 show_mac(ipfw_insn *cmd, int show_or)
214 {
215           ipfw_insn_mac *m = (ipfw_insn_mac *)cmd;
216           if (show_or)
217                     printf(" or");
218           else
219                     printf(" mac");
220           print_mac( m->addr, m->mask);
221           print_mac( m->addr + 6, m->mask + 6);
222 }
223 
224 void
show_mac_from(ipfw_insn * cmd,int show_or)225 show_mac_from(ipfw_insn *cmd, int show_or)
226 {
227           ipfw_insn_mac *m = (ipfw_insn_mac *)cmd;
228           if (show_or)
229                     printf(" or");
230           else
231                     printf(" mac-from");
232           print_mac( m->addr + 6, m->mask + 6);
233 }
234 
235 void
show_mac_from_lookup(ipfw_insn * cmd,int show_or)236 show_mac_from_lookup(ipfw_insn *cmd, int show_or)
237 {
238           printf(" mac-from table %d", cmd->arg1);
239 }
240 
241 void
show_mac_to(ipfw_insn * cmd,int show_or)242 show_mac_to(ipfw_insn *cmd, int show_or)
243 {
244           ipfw_insn_mac *m = (ipfw_insn_mac *)cmd;
245           if (show_or)
246                     printf(" or");
247           else
248                     printf(" mac-to");
249           print_mac( m->addr, m->mask);
250 }
251 
252 void
show_mac_to_lookup(ipfw_insn * cmd,int show_or)253 show_mac_to_lookup(ipfw_insn *cmd, int show_or)
254 {
255           printf(" mac-to table %d", cmd->arg1);
256 }
257 
258 void
load_module(register_func function,register_keyword keyword)259 load_module(register_func function, register_keyword keyword)
260 {
261           keyword(MODULE_LAYER2_ID, O_LAYER2_LAYER2, "layer2", FILTER);
262           function(MODULE_LAYER2_ID, O_LAYER2_LAYER2,
263                               (parser_func)parse_layer2, (shower_func)show_layer2);
264 
265           keyword(MODULE_LAYER2_ID, O_LAYER2_MAC, "mac", FILTER);
266           function(MODULE_LAYER2_ID, O_LAYER2_MAC,
267                               (parser_func)parse_mac,(shower_func)show_mac);
268           keyword(MODULE_LAYER2_ID, O_LAYER2_MAC_SRC, "mac-from", FROM);
269           function(MODULE_LAYER2_ID, O_LAYER2_MAC_SRC,
270                               (parser_func)parse_mac_from,(shower_func)show_mac_from);
271           keyword(MODULE_LAYER2_ID, O_LAYER2_MAC_SRC_LOOKUP,
272                               "mac-from-[table]", FROM);
273           function(MODULE_LAYER2_ID, O_LAYER2_MAC_SRC_LOOKUP,
274                               (parser_func)parse_mac_from,
275                               (shower_func)show_mac_from_lookup);
276 
277           keyword(MODULE_LAYER2_ID, O_LAYER2_MAC_DST, "mac-to", TO);
278           function(MODULE_LAYER2_ID, O_LAYER2_MAC_DST,
279                               (parser_func)parse_mac_to,(shower_func)show_mac_to);
280           keyword(MODULE_LAYER2_ID, O_LAYER2_MAC_DST_LOOKUP,
281                               "mac-to-[table]", TO);
282           function(MODULE_LAYER2_ID, O_LAYER2_MAC_DST_LOOKUP,
283                               (parser_func)parse_mac_to,
284                               (shower_func)show_mac_to_lookup);
285 }
286