2 * Copyright (c) 2004 Andre Oppermann, Internet Business Solutions AG
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD: src/sys/netinet/ip_fw_pfil.c,v 1.25.2.2 2008/04/25 10:26:30 oleg Exp $");
30 #if !defined(KLD_MODULE)
35 #error IPFIREWALL requires INET.
37 #endif /* KLD_MODULE */
38 #include "opt_inet6.h"
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/malloc.h>
44 #include <sys/module.h>
45 #include <sys/kernel.h>
46 #include <sys/socket.h>
47 #include <sys/socketvar.h>
48 #include <sys/sysctl.h>
54 #include <netinet/in.h>
55 #include <netinet/ip.h>
56 #include <netinet/ip_var.h>
57 #include <netinet/ip_fw.h>
58 #include <netinet/ip_divert.h>
59 #include <netinet/ip_dummynet.h>
61 #include <netgraph/ng_ipfw.h>
63 #include <machine/in_cksum.h>
72 int ipfw_chg_hook(SYSCTL_HANDLER_ARGS);
75 ip_divert_packet_t *ip_divert_ptr = NULL;
78 ng_ipfw_input_t *ng_ipfw_input_p = NULL;
80 /* Forward declarations. */
81 static int ipfw_divert(struct mbuf **, int, int);
86 ipfw_check_in(void *arg, struct mbuf **m0, struct ifnet *ifp, int dir,
89 struct ip_fw_args args;
90 struct ng_ipfw_tag *ng_tag;
95 #ifdef IPFIREWALL_FORWARD
96 struct m_tag *fwd_tag;
99 KASSERT(dir == PFIL_IN, ("ipfw_check_in wrong direction!"));
101 bzero(&args, sizeof(args));
103 ng_tag = (struct ng_ipfw_tag *)m_tag_locate(*m0, NGM_IPFW_COOKIE, 0,
105 if (ng_tag != NULL) {
106 KASSERT(ng_tag->dir == NG_IPFW_IN,
107 ("ng_ipfw tag with wrong direction"));
108 args.rule = ng_tag->rule;
109 args.rule_id = ng_tag->rule_id;
110 args.chain_id = ng_tag->chain_id;
111 m_tag_delete(*m0, (struct m_tag *)ng_tag);
115 dn_tag = m_tag_find(*m0, PACKET_TAG_DUMMYNET, NULL);
117 struct dn_pkt_tag *dt;
119 dt = (struct dn_pkt_tag *)(dn_tag+1);
120 args.rule = dt->rule;
121 args.rule_id = dt->rule_id;
122 args.chain_id = dt->chain_id;
124 m_tag_delete(*m0, dn_tag);
129 ipfw = ipfw_chk(&args);
130 *m0 = args.m; /* args.m can be modified by ipfw_chk */
133 KASSERT(*m0 != NULL || ipfw == IP_FW_DENY, ("%s: m0 is NULL",
138 if (args.next_hop == NULL)
141 #ifdef IPFIREWALL_FORWARD
142 fwd_tag = m_tag_get(PACKET_TAG_IPFORWARD,
143 sizeof(struct sockaddr_in), M_NOWAIT);
146 bcopy(args.next_hop, (fwd_tag+1), sizeof(struct sockaddr_in));
147 m_tag_prepend(*m0, fwd_tag);
149 if (in_localip(args.next_hop->sin_addr))
150 (*m0)->m_flags |= M_FASTFWD_OURS;
153 break; /* not reached */
157 break; /* not reached */
159 /* here packets come after the ipfw classification */
161 if (ip_dn_io_ptr == NULL)
163 if (mtod(*m0, struct ip *)->ip_v == 4)
164 ip_dn_io_ptr(m0, DN_TO_IP_IN, &args);
165 else if (mtod(*m0, struct ip *)->ip_v == 6)
166 ip_dn_io_ptr(m0, DN_TO_IP6_IN, &args);
169 return 0; /* packet consumed */
176 divert = ipfw_divert(m0, DIV_DIR_IN, tee);
179 return 0; /* packet consumed */
182 goto again; /* continue with packet */
188 (void)ng_ipfw_input_p(m0, NG_IPFW_IN, &args, 1);
189 goto again; /* continue with packet */
194 return ng_ipfw_input_p(m0, NG_IPFW_IN, &args, 0);
197 goto again; /* continue with packet */
203 KASSERT(0, ("%s: unknown retval", __func__));
212 return 0; /* not filtered */
216 ipfw_check_out(void *arg, struct mbuf **m0, struct ifnet *ifp, int dir,
219 struct ip_fw_args args;
220 struct ng_ipfw_tag *ng_tag;
221 struct m_tag *dn_tag;
225 #ifdef IPFIREWALL_FORWARD
226 struct m_tag *fwd_tag;
229 KASSERT(dir == PFIL_OUT, ("ipfw_check_out wrong direction!"));
231 bzero(&args, sizeof(args));
233 ng_tag = (struct ng_ipfw_tag *)m_tag_locate(*m0, NGM_IPFW_COOKIE, 0,
235 if (ng_tag != NULL) {
236 KASSERT(ng_tag->dir == NG_IPFW_OUT,
237 ("ng_ipfw tag with wrong direction"));
238 args.rule = ng_tag->rule;
239 args.rule_id = ng_tag->rule_id;
240 args.chain_id = ng_tag->chain_id;
241 m_tag_delete(*m0, (struct m_tag *)ng_tag);
245 dn_tag = m_tag_find(*m0, PACKET_TAG_DUMMYNET, NULL);
246 if (dn_tag != NULL) {
247 struct dn_pkt_tag *dt;
249 dt = (struct dn_pkt_tag *)(dn_tag+1);
250 args.rule = dt->rule;
251 args.rule_id = dt->rule_id;
252 args.chain_id = dt->chain_id;
254 m_tag_delete(*m0, dn_tag);
260 ipfw = ipfw_chk(&args);
261 *m0 = args.m; /* args.m can be modified by ipfw_chk */
264 KASSERT(*m0 != NULL || ipfw == IP_FW_DENY, ("%s: m0 is NULL",
269 if (args.next_hop == NULL)
271 #ifdef IPFIREWALL_FORWARD
272 /* Overwrite existing tag. */
273 fwd_tag = m_tag_find(*m0, PACKET_TAG_IPFORWARD, NULL);
274 if (fwd_tag == NULL) {
275 fwd_tag = m_tag_get(PACKET_TAG_IPFORWARD,
276 sizeof(struct sockaddr_in), M_NOWAIT);
280 m_tag_unlink(*m0, fwd_tag);
281 bcopy(args.next_hop, (fwd_tag+1), sizeof(struct sockaddr_in));
282 m_tag_prepend(*m0, fwd_tag);
284 if (in_localip(args.next_hop->sin_addr))
285 (*m0)->m_flags |= M_FASTFWD_OURS;
288 break; /* not reached */
292 break; /* not reached */
295 if (ip_dn_io_ptr == NULL)
297 if (mtod(*m0, struct ip *)->ip_v == 4)
298 ip_dn_io_ptr(m0, DN_TO_IP_OUT, &args);
299 else if (mtod(*m0, struct ip *)->ip_v == 6)
300 ip_dn_io_ptr(m0, DN_TO_IP6_OUT, &args);
303 return 0; /* packet consumed */
312 divert = ipfw_divert(m0, DIV_DIR_OUT, tee);
315 return 0; /* packet consumed */
318 goto again; /* continue with packet */
324 (void)ng_ipfw_input_p(m0, NG_IPFW_OUT, &args, 1);
325 goto again; /* continue with packet */
330 return ng_ipfw_input_p(m0, NG_IPFW_OUT, &args, 0);
333 goto again; /* continue with packet */
339 KASSERT(0, ("%s: unknown retval", __func__));
348 return 0; /* not filtered */
352 ipfw_divert(struct mbuf **m, int incoming, int tee)
355 * ipfw_chk() has already tagged the packet with the divert tag.
356 * If tee is set, copy packet and return original.
357 * If not tee, consume packet and send it to divert socket.
359 struct mbuf *clone, *reass;
365 /* Is divert module loaded? */
366 if (ip_divert_ptr == NULL)
369 /* Cloning needed for tee? */
371 clone = m_dup(*m, M_DONTWAIT);
375 /* In case m_dup was unable to allocate mbufs. */
380 * Divert listeners can only handle non-fragmented packets.
381 * However when tee is set we will *not* de-fragment the packets;
382 * Doing do would put the reassembly into double-jeopardy. On top
383 * of that someone doing a tee will probably want to get the packet
384 * in its original form.
386 ip = mtod(clone, struct ip *);
387 if (!tee && ip->ip_off & (IP_MF | IP_OFFMASK)) {
389 /* Reassemble packet. */
390 reass = ip_reass(clone);
393 * IP header checksum fixup after reassembly and leave header
394 * in network byte order.
397 ip = mtod(reass, struct ip *);
398 hlen = ip->ip_hl << 2;
399 ip->ip_len = htons(ip->ip_len);
400 ip->ip_off = htons(ip->ip_off);
402 if (hlen == sizeof(struct ip))
403 ip->ip_sum = in_cksum_hdr(ip);
405 ip->ip_sum = in_cksum(reass, hlen);
410 /* Convert header to network byte order. */
411 ip->ip_len = htons(ip->ip_len);
412 ip->ip_off = htons(ip->ip_off);
415 /* Do the dirty job... */
416 if (clone && ip_divert_ptr != NULL)
417 ip_divert_ptr(clone, incoming);
421 * For tee we leave the divert tag attached to original packet.
422 * It will then continue rule evaluation after the tee rule.
427 /* Packet diverted and consumed */
438 struct pfil_head *pfh_inet;
440 pfh_inet = pfil_head_get(PFIL_TYPE_AF, AF_INET);
441 if (pfh_inet == NULL)
444 (void)pfil_add_hook(ipfw_check_in, NULL, PFIL_IN | PFIL_WAITOK,
446 (void)pfil_add_hook(ipfw_check_out, NULL, PFIL_OUT | PFIL_WAITOK,
455 struct pfil_head *pfh_inet;
457 pfh_inet = pfil_head_get(PFIL_TYPE_AF, AF_INET);
458 if (pfh_inet == NULL)
461 (void)pfil_remove_hook(ipfw_check_in, NULL, PFIL_IN | PFIL_WAITOK,
463 (void)pfil_remove_hook(ipfw_check_out, NULL, PFIL_OUT | PFIL_WAITOK,
473 struct pfil_head *pfh_inet6;
475 pfh_inet6 = pfil_head_get(PFIL_TYPE_AF, AF_INET6);
476 if (pfh_inet6 == NULL)
479 (void)pfil_add_hook(ipfw_check_in, NULL, PFIL_IN | PFIL_WAITOK,
481 (void)pfil_add_hook(ipfw_check_out, NULL, PFIL_OUT | PFIL_WAITOK,
490 struct pfil_head *pfh_inet6;
492 pfh_inet6 = pfil_head_get(PFIL_TYPE_AF, AF_INET6);
493 if (pfh_inet6 == NULL)
496 (void)pfil_remove_hook(ipfw_check_in, NULL, PFIL_IN | PFIL_WAITOK,
498 (void)pfil_remove_hook(ipfw_check_out, NULL, PFIL_OUT | PFIL_WAITOK,
506 ipfw_chg_hook(SYSCTL_HANDLER_ARGS)
508 int enable = *(int *)arg1;
511 error = sysctl_handle_int(oidp, &enable, 0, req);
515 enable = (enable) ? 1 : 0;
517 if (enable == *(int *)arg1)
520 if (arg1 == &fw_enable) {
524 error = ipfw_unhook();
527 if (arg1 == &fw6_enable) {
529 error = ipfw6_hook();
531 error = ipfw6_unhook();
538 *(int *)arg1 = enable;
544 ipfw_modevent(module_t mod, int type, void *unused)
550 if ((err = ipfw_init()) != 0) {
551 printf("ipfw_init() error\n");
554 if ((err = ipfw_hook()) != 0) {
555 printf("ipfw_hook() error\n");
559 if ((err = ipfw6_hook()) != 0) {
560 printf("ipfw_hook() error\n");
567 if ((err = ipfw_unhook()) > 0)
570 if ((err = ipfw6_unhook()) > 0)
583 static moduledata_t ipfwmod = {
588 DECLARE_MODULE(ipfw, ipfwmod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY - 256);
589 MODULE_VERSION(ipfw, 2);