1 /**
2 * This file was imported from the iptables sources.
3 * Copyright (C) 1999-2008 Netfilter Core Team
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; only version 2 of the License is applicable.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 */
19 /* Library which manipulates firewall rules. Version 0.1. */
21 /* Architecture of firewall rules is as follows:
22 *
23 * Chains go INPUT, FORWARD, OUTPUT then user chains.
24 * Each user chain starts with an ERROR node.
25 * Every chain ends with an unconditional jump: a RETURN for user chains,
26 * and a POLICY for built-ins.
27 */
29 /* (C)1999 Paul ``Rusty'' Russell - Placed under the GNU GPL (See
30 COPYING for details). */
32 #include <assert.h>
33 #include <string.h>
34 #include <errno.h>
35 #include <stdlib.h>
36 #include <stdio.h>
37 #include <unistd.h>
38 #include <arpa/inet.h>
40 #ifdef DEBUG_CONNTRACK
41 #define inline
42 #endif
44 #if !defined(__GLIBC__) || (__GLIBC__ < 2)
45 typedef unsigned int socklen_t;
46 #endif
48 #include "libip6tc.h"
50 #define HOOK_PRE_ROUTING NF_IP6_PRE_ROUTING
51 #define HOOK_LOCAL_IN NF_IP6_LOCAL_IN
52 #define HOOK_FORWARD NF_IP6_FORWARD
53 #define HOOK_LOCAL_OUT NF_IP6_LOCAL_OUT
54 #define HOOK_POST_ROUTING NF_IP6_POST_ROUTING
56 #define STRUCT_ENTRY_TARGET struct ip6t_entry_target
57 #define STRUCT_ENTRY struct ip6t_entry
58 #define STRUCT_ENTRY_MATCH struct ip6t_entry_match
59 #define STRUCT_GETINFO struct ip6t_getinfo
60 #define STRUCT_GET_ENTRIES struct ip6t_get_entries
61 #define STRUCT_COUNTERS struct ip6t_counters
62 #define STRUCT_COUNTERS_INFO struct ip6t_counters_info
63 #define STRUCT_STANDARD_TARGET struct ip6t_standard_target
64 #define STRUCT_REPLACE struct ip6t_replace
66 #define STRUCT_TC_HANDLE struct ip6tc_handle
67 #define TC_HANDLE_T ip6tc_handle_t
69 #define ENTRY_ITERATE IP6T_ENTRY_ITERATE
70 #define TABLE_MAXNAMELEN IP6T_TABLE_MAXNAMELEN
71 #define FUNCTION_MAXNAMELEN IP6T_FUNCTION_MAXNAMELEN
73 #define GET_TARGET ip6t_get_target
75 #define ERROR_TARGET IP6T_ERROR_TARGET
76 #define NUMHOOKS NF_IP6_NUMHOOKS
78 #define IPT_CHAINLABEL ip6t_chainlabel
80 #define TC_DUMP_ENTRIES dump_entries6
81 #define TC_IS_CHAIN ip6tc_is_chain
82 #define TC_FIRST_CHAIN ip6tc_first_chain
83 #define TC_NEXT_CHAIN ip6tc_next_chain
84 #define TC_FIRST_RULE ip6tc_first_rule
85 #define TC_NEXT_RULE ip6tc_next_rule
86 #define TC_GET_TARGET ip6tc_get_target
87 #define TC_BUILTIN ip6tc_builtin
88 #define TC_GET_POLICY ip6tc_get_policy
89 #define TC_INSERT_ENTRY ip6tc_insert_entry
90 #define TC_REPLACE_ENTRY ip6tc_replace_entry
91 #define TC_APPEND_ENTRY ip6tc_append_entry
92 #define TC_DELETE_ENTRY ip6tc_delete_entry
93 #define TC_DELETE_NUM_ENTRY ip6tc_delete_num_entry
94 #define TC_CHECK_PACKET ip6tc_check_packet
95 #define TC_FLUSH_ENTRIES ip6tc_flush_entries
96 #define TC_ZERO_ENTRIES ip6tc_zero_entries
97 #define TC_ZERO_COUNTER ip6tc_zero_counter
98 #define TC_READ_COUNTER ip6tc_read_counter
99 #define TC_SET_COUNTER ip6tc_set_counter
100 #define TC_CREATE_CHAIN ip6tc_create_chain
101 #define TC_GET_REFERENCES ip6tc_get_references
102 #define TC_DELETE_CHAIN ip6tc_delete_chain
103 #define TC_RENAME_CHAIN ip6tc_rename_chain
104 #define TC_SET_POLICY ip6tc_set_policy
105 #define TC_GET_RAW_SOCKET ip6tc_get_raw_socket
106 #define TC_INIT ip6tc_init
107 #define TC_FREE ip6tc_free
108 #define TC_COMMIT ip6tc_commit
109 #define TC_STRERROR ip6tc_strerror
110 #define TC_NUM_RULES ip6tc_num_rules
111 #define TC_GET_RULE ip6tc_get_rule
113 #define TC_AF AF_INET6
114 #define TC_IPPROTO IPPROTO_IPV6
116 #define SO_SET_REPLACE IP6T_SO_SET_REPLACE
117 #define SO_SET_ADD_COUNTERS IP6T_SO_SET_ADD_COUNTERS
118 #define SO_GET_INFO IP6T_SO_GET_INFO
119 #define SO_GET_ENTRIES IP6T_SO_GET_ENTRIES
120 #define SO_GET_VERSION IP6T_SO_GET_VERSION
122 #define STANDARD_TARGET IP6T_STANDARD_TARGET
123 #define LABEL_RETURN IP6TC_LABEL_RETURN
124 #define LABEL_ACCEPT IP6TC_LABEL_ACCEPT
125 #define LABEL_DROP IP6TC_LABEL_DROP
126 #define LABEL_QUEUE IP6TC_LABEL_QUEUE
128 #define ALIGN IP6T_ALIGN
129 #define RETURN IP6T_RETURN
131 #include "libiptc.c"
133 #define BIT6(a, l) \
134 ((ntohl(a->s6_addr32[(l) / 32]) >> (31 - ((l) & 31))) & 1)
136 int
137 ipv6_prefix_length(const struct in6_addr *a)
138 {
139 int l, i;
140 for (l = 0; l < 128; l++) {
141 if (BIT6(a, l) == 0)
142 break;
143 }
144 for (i = l + 1; i < 128; i++) {
145 if (BIT6(a, i) == 1)
146 return -1;
147 }
148 return l;
149 }
151 static int
152 dump_entry(struct ip6t_entry *e, const ip6tc_handle_t handle)
153 {
154 size_t i;
155 char buf[40];
156 int len;
157 struct ip6t_entry_target *t;
159 printf("Entry %u (%lu):\n", iptcb_entry2index(handle, e),
160 iptcb_entry2offset(handle, e));
161 puts("SRC IP: ");
162 inet_ntop(AF_INET6, &e->ipv6.src, buf, sizeof buf);
163 puts(buf);
164 putchar('/');
165 len = ipv6_prefix_length(&e->ipv6.smsk);
166 if (len != -1)
167 printf("%d", len);
168 else {
169 inet_ntop(AF_INET6, &e->ipv6.smsk, buf, sizeof buf);
170 puts(buf);
171 }
172 putchar('\n');
174 puts("DST IP: ");
175 inet_ntop(AF_INET6, &e->ipv6.dst, buf, sizeof buf);
176 puts(buf);
177 putchar('/');
178 len = ipv6_prefix_length(&e->ipv6.dmsk);
179 if (len != -1)
180 printf("%d", len);
181 else {
182 inet_ntop(AF_INET6, &e->ipv6.dmsk, buf, sizeof buf);
183 puts(buf);
184 }
185 putchar('\n');
187 printf("Interface: `%s'/", e->ipv6.iniface);
188 for (i = 0; i < IFNAMSIZ; i++)
189 printf("%c", e->ipv6.iniface_mask[i] ? 'X' : '.');
190 printf("to `%s'/", e->ipv6.outiface);
191 for (i = 0; i < IFNAMSIZ; i++)
192 printf("%c", e->ipv6.outiface_mask[i] ? 'X' : '.');
193 printf("\nProtocol: %u\n", e->ipv6.proto);
194 if (e->ipv6.flags & IP6T_F_TOS)
195 printf("TOS: %u\n", e->ipv6.tos);
196 printf("Flags: %02X\n", e->ipv6.flags);
197 printf("Invflags: %02X\n", e->ipv6.invflags);
198 printf("Counters: %llu packets, %llu bytes\n",
199 (unsigned long long)e->counters.pcnt, (unsigned long long)e->counters.bcnt);
200 printf("Cache: %08X\n", e->nfcache);
202 IP6T_MATCH_ITERATE(e, print_match);
204 t = ip6t_get_target(e);
205 printf("Target name: `%s' [%u]\n", t->u.user.name, t->u.target_size);
206 if (strcmp(t->u.user.name, IP6T_STANDARD_TARGET) == 0) {
207 int pos = *(int *)t->data;
208 if (pos < 0)
209 printf("verdict=%s\n",
210 pos == -NF_ACCEPT-1 ? "NF_ACCEPT"
211 : pos == -NF_DROP-1 ? "NF_DROP"
212 : pos == IP6T_RETURN ? "RETURN"
213 : "UNKNOWN");
214 else
215 printf("verdict=%u\n", pos);
216 } else if (strcmp(t->u.user.name, IP6T_ERROR_TARGET) == 0)
217 printf("error=`%s'\n", t->data);
219 printf("\n");
220 return 0;
221 }
223 static unsigned char *
224 is_same(const STRUCT_ENTRY *a, const STRUCT_ENTRY *b,
225 unsigned char *matchmask)
226 {
227 unsigned int i;
228 unsigned char *mptr;
230 /* Always compare head structures: ignore mask here. */
231 if (memcmp(&a->ipv6.src, &b->ipv6.src, sizeof(struct in6_addr))
232 || memcmp(&a->ipv6.dst, &b->ipv6.dst, sizeof(struct in6_addr))
233 || memcmp(&a->ipv6.smsk, &b->ipv6.smsk, sizeof(struct in6_addr))
234 || memcmp(&a->ipv6.dmsk, &b->ipv6.dmsk, sizeof(struct in6_addr))
235 || a->ipv6.proto != b->ipv6.proto
236 || a->ipv6.tos != b->ipv6.tos
237 || a->ipv6.flags != b->ipv6.flags
238 || a->ipv6.invflags != b->ipv6.invflags)
239 return NULL;
241 for (i = 0; i < IFNAMSIZ; i++) {
242 if (a->ipv6.iniface_mask[i] != b->ipv6.iniface_mask[i])
243 return NULL;
244 if ((a->ipv6.iniface[i] & a->ipv6.iniface_mask[i])
245 != (b->ipv6.iniface[i] & b->ipv6.iniface_mask[i]))
246 return NULL;
247 if (a->ipv6.outiface_mask[i] != b->ipv6.outiface_mask[i])
248 return NULL;
249 if ((a->ipv6.outiface[i] & a->ipv6.outiface_mask[i])
250 != (b->ipv6.outiface[i] & b->ipv6.outiface_mask[i]))
251 return NULL;
252 }
254 if (a->target_offset != b->target_offset
255 || a->next_offset != b->next_offset)
256 return NULL;
258 mptr = matchmask + sizeof(STRUCT_ENTRY);
259 if (IP6T_MATCH_ITERATE(a, match_different, a->elems, b->elems, &mptr))
260 return NULL;
261 mptr += IP6T_ALIGN(sizeof(struct ip6t_entry_target));
263 return mptr;
264 }
266 /* All zeroes == unconditional rule. */
267 static inline int
268 unconditional(const struct ip6t_ip6 *ipv6)
269 {
270 unsigned int i;
272 for (i = 0; i < sizeof(*ipv6); i++)
273 if (((char *)ipv6)[i])
274 break;
276 return (i == sizeof(*ipv6));
277 }
279 #ifdef IPTC_DEBUG
280 /* Do every conceivable sanity check on the handle */
281 static void
282 do_check(TC_HANDLE_T h, unsigned int line)
283 {
284 unsigned int i, n;
285 unsigned int user_offset; /* Offset of first user chain */
286 int was_return;
288 assert(h->changed == 0 || h->changed == 1);
289 if (strcmp(h->info.name, "filter") == 0) {
290 assert(h->info.valid_hooks
291 == (1 << NF_IP6_LOCAL_IN
292 | 1 << NF_IP6_FORWARD
293 | 1 << NF_IP6_LOCAL_OUT));
295 /* Hooks should be first three */
296 assert(h->info.hook_entry[NF_IP6_LOCAL_IN] == 0);
298 n = get_chain_end(h, 0);
299 n += get_entry(h, n)->next_offset;
300 assert(h->info.hook_entry[NF_IP6_FORWARD] == n);
302 n = get_chain_end(h, n);
303 n += get_entry(h, n)->next_offset;
304 assert(h->info.hook_entry[NF_IP6_LOCAL_OUT] == n);
306 user_offset = h->info.hook_entry[NF_IP6_LOCAL_OUT];
307 } else if (strcmp(h->info.name, "nat") == 0) {
308 assert((h->info.valid_hooks
309 == (1 << NF_IP6_PRE_ROUTING
310 | 1 << NF_IP6_LOCAL_OUT
311 | 1 << NF_IP6_POST_ROUTING)) ||
312 (h->info.valid_hooks
313 == (1 << NF_IP6_PRE_ROUTING
314 | 1 << NF_IP6_LOCAL_IN
315 | 1 << NF_IP6_LOCAL_OUT
316 | 1 << NF_IP6_POST_ROUTING)));
318 assert(h->info.hook_entry[NF_IP6_PRE_ROUTING] == 0);
320 n = get_chain_end(h, 0);
322 n += get_entry(h, n)->next_offset;
323 assert(h->info.hook_entry[NF_IP6_POST_ROUTING] == n);
324 n = get_chain_end(h, n);
326 n += get_entry(h, n)->next_offset;
327 assert(h->info.hook_entry[NF_IP6_LOCAL_OUT] == n);
328 user_offset = h->info.hook_entry[NF_IP6_LOCAL_OUT];
330 if (h->info.valid_hooks & (1 << NF_IP6_LOCAL_IN)) {
331 n = get_chain_end(h, n);
332 n += get_entry(h, n)->next_offset;
333 assert(h->info.hook_entry[NF_IP6_LOCAL_IN] == n);
334 user_offset = h->info.hook_entry[NF_IP6_LOCAL_IN];
335 }
337 } else if (strcmp(h->info.name, "mangle") == 0) {
338 /* This code is getting ugly because linux < 2.4.18-pre6 had
339 * two mangle hooks, linux >= 2.4.18-pre6 has five mangle hooks
340 * */
341 assert((h->info.valid_hooks
342 == (1 << NF_IP6_PRE_ROUTING
343 | 1 << NF_IP6_LOCAL_OUT)) ||
344 (h->info.valid_hooks
345 == (1 << NF_IP6_PRE_ROUTING
346 | 1 << NF_IP6_LOCAL_IN
347 | 1 << NF_IP6_FORWARD
348 | 1 << NF_IP6_LOCAL_OUT
349 | 1 << NF_IP6_POST_ROUTING)));
351 /* Hooks should be first five */
352 assert(h->info.hook_entry[NF_IP6_PRE_ROUTING] == 0);
354 n = get_chain_end(h, 0);
356 if (h->info.valid_hooks & (1 << NF_IP6_LOCAL_IN)) {
357 n += get_entry(h, n)->next_offset;
358 assert(h->info.hook_entry[NF_IP6_LOCAL_IN] == n);
359 n = get_chain_end(h, n);
360 }
362 if (h->info.valid_hooks & (1 << NF_IP6_FORWARD)) {
363 n += get_entry(h, n)->next_offset;
364 assert(h->info.hook_entry[NF_IP6_FORWARD] == n);
365 n = get_chain_end(h, n);
366 }
368 n += get_entry(h, n)->next_offset;
369 assert(h->info.hook_entry[NF_IP6_LOCAL_OUT] == n);
370 user_offset = h->info.hook_entry[NF_IP6_LOCAL_OUT];
372 if (h->info.valid_hooks & (1 << NF_IP6_POST_ROUTING)) {
373 n = get_chain_end(h, n);
374 n += get_entry(h, n)->next_offset;
375 assert(h->info.hook_entry[NF_IP6_POST_ROUTING] == n);
376 user_offset = h->info.hook_entry[NF_IP6_POST_ROUTING];
377 }
378 } else if (strcmp(h->info.name, "raw") == 0) {
379 assert(h->info.valid_hooks
380 == (1 << NF_IP6_PRE_ROUTING
381 | 1 << NF_IP6_LOCAL_OUT));
383 /* Hooks should be first three */
384 assert(h->info.hook_entry[NF_IP6_PRE_ROUTING] == 0);
386 n = get_chain_end(h, n);
387 n += get_entry(h, n)->next_offset;
388 assert(h->info.hook_entry[NF_IP6_LOCAL_OUT] == n);
390 user_offset = h->info.hook_entry[NF_IP6_LOCAL_OUT];
391 } else {
392 fprintf(stderr, "Unknown table `%s'\n", h->info.name);
393 abort();
394 }
396 /* User chain == end of last builtin + policy entry */
397 user_offset = get_chain_end(h, user_offset);
398 user_offset += get_entry(h, user_offset)->next_offset;
400 /* Overflows should be end of entry chains, and unconditional
401 policy nodes. */
402 for (i = 0; i < NUMHOOKS; i++) {
403 STRUCT_ENTRY *e;
404 STRUCT_STANDARD_TARGET *t;
406 if (!(h->info.valid_hooks & (1 << i)))
407 continue;
408 assert(h->info.underflow[i]
409 == get_chain_end(h, h->info.hook_entry[i]));
411 e = get_entry(h, get_chain_end(h, h->info.hook_entry[i]));
412 assert(unconditional(&e->ipv6));
413 assert(e->target_offset == sizeof(*e));
414 t = (STRUCT_STANDARD_TARGET *)GET_TARGET(e);
415 printf("target_size=%u, align=%u\n",
416 t->target.u.target_size, ALIGN(sizeof(*t)));
417 assert(t->target.u.target_size == ALIGN(sizeof(*t)));
418 assert(e->next_offset == sizeof(*e) + ALIGN(sizeof(*t)));
420 assert(strcmp(t->target.u.user.name, STANDARD_TARGET)==0);
421 assert(t->verdict == -NF_DROP-1 || t->verdict == -NF_ACCEPT-1);
423 /* Hooks and underflows must be valid entries */
424 iptcb_entry2index(h, get_entry(h, h->info.hook_entry[i]));
425 iptcb_entry2index(h, get_entry(h, h->info.underflow[i]));
426 }
428 assert(h->info.size
429 >= h->info.num_entries * (sizeof(STRUCT_ENTRY)
430 +sizeof(STRUCT_STANDARD_TARGET)));
432 assert(h->entries.size
433 >= (h->new_number
434 * (sizeof(STRUCT_ENTRY)
435 + sizeof(STRUCT_STANDARD_TARGET))));
436 assert(strcmp(h->info.name, h->entries.name) == 0);
438 i = 0; n = 0;
439 was_return = 0;
441 #if 0
442 /* Check all the entries. */
443 ENTRY_ITERATE(h->entries.entrytable, h->entries.size,
444 check_entry, &i, &n, user_offset, &was_return, h);
446 assert(i == h->new_number);
447 assert(n == h->entries.size);
449 /* Final entry must be error node */
450 assert(strcmp(GET_TARGET(index2entry(h, h->new_number-1))
451 ->u.user.name,
452 ERROR_TARGET) == 0);
453 #endif
454 }
455 #endif /*IPTC_DEBUG*/