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("$FreeBSD$");
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>
47 #include <sys/rwlock.h>
48 #include <sys/socket.h>
49 #include <sys/socketvar.h>
50 #include <sys/sysctl.h>
51 #include <sys/ucred.h>
54 #include <net/route.h>
57 #include <netinet/in.h>
58 #include <netinet/in_systm.h>
59 #include <netinet/ip.h>
60 #include <netinet/ip_var.h>
61 #include <netinet/ip_fw.h>
62 #include <netinet/ip_divert.h>
63 #include <netinet/ip_dummynet.h>
65 #include <netgraph/ng_ipfw.h>
67 #include <machine/in_cksum.h>
69 VNET_DEFINE(int, fw_enable) = 1;
71 VNET_DEFINE(int, fw6_enable) = 1;
74 int ipfw_chg_hook(SYSCTL_HANDLER_ARGS);
77 ip_divert_packet_t *ip_divert_ptr = NULL;
80 ng_ipfw_input_t *ng_ipfw_input_p = NULL;
82 /* Forward declarations. */
83 static int ipfw_divert(struct mbuf **, int, int);
88 ipfw_check_in(void *arg, struct mbuf **m0, struct ifnet *ifp, int dir,
91 struct ip_fw_args args;
92 struct ng_ipfw_tag *ng_tag;
97 #ifdef IPFIREWALL_FORWARD
98 struct m_tag *fwd_tag;
101 KASSERT(dir == PFIL_IN, ("ipfw_check_in wrong direction!"));
103 bzero(&args, sizeof(args));
105 ng_tag = (struct ng_ipfw_tag *)m_tag_locate(*m0, NGM_IPFW_COOKIE, 0,
107 if (ng_tag != NULL) {
108 KASSERT(ng_tag->dir == NG_IPFW_IN,
109 ("ng_ipfw tag with wrong direction"));
110 args.rule = ng_tag->rule;
111 args.rule_id = ng_tag->rule_id;
112 args.chain_id = ng_tag->chain_id;
113 m_tag_delete(*m0, (struct m_tag *)ng_tag);
117 dn_tag = m_tag_find(*m0, PACKET_TAG_DUMMYNET, NULL);
119 struct dn_pkt_tag *dt;
121 dt = (struct dn_pkt_tag *)(dn_tag+1);
122 args.rule = dt->rule;
123 args.rule_id = dt->rule_id;
124 args.chain_id = dt->chain_id;
126 m_tag_delete(*m0, dn_tag);
133 if (V_fw_one_pass == 0 || args.rule == NULL) {
134 ipfw = ipfw_chk(&args);
139 KASSERT(*m0 != NULL || ipfw == IP_FW_DENY, ("%s: m0 is NULL",
144 if (args.next_hop == NULL)
147 #ifdef IPFIREWALL_FORWARD
148 fwd_tag = m_tag_get(PACKET_TAG_IPFORWARD,
149 sizeof(struct sockaddr_in), M_NOWAIT);
152 bcopy(args.next_hop, (fwd_tag+1), sizeof(struct sockaddr_in));
153 m_tag_prepend(*m0, fwd_tag);
155 if (in_localip(args.next_hop->sin_addr))
156 (*m0)->m_flags |= M_FASTFWD_OURS;
159 break; /* not reached */
163 break; /* not reached */
166 if (ip_dn_io_ptr == NULL)
168 if (mtod(*m0, struct ip *)->ip_v == 4)
169 ip_dn_io_ptr(m0, DN_TO_IP_IN, &args);
170 else if (mtod(*m0, struct ip *)->ip_v == 6)
171 ip_dn_io_ptr(m0, DN_TO_IP6_IN, &args);
174 return 0; /* packet consumed */
181 divert = ipfw_divert(m0, DIV_DIR_IN, tee);
184 return 0; /* packet consumed */
187 goto again; /* continue with packet */
193 (void)ng_ipfw_input_p(m0, NG_IPFW_IN, &args, 1);
194 goto again; /* continue with packet */
199 return ng_ipfw_input_p(m0, NG_IPFW_IN, &args, 0);
202 goto again; /* continue with packet */
208 KASSERT(0, ("%s: unknown retval", __func__));
217 return 0; /* not filtered */
221 ipfw_check_out(void *arg, struct mbuf **m0, struct ifnet *ifp, int dir,
224 struct ip_fw_args args;
225 struct ng_ipfw_tag *ng_tag;
226 struct m_tag *dn_tag;
230 #ifdef IPFIREWALL_FORWARD
231 struct m_tag *fwd_tag;
234 KASSERT(dir == PFIL_OUT, ("ipfw_check_out wrong direction!"));
236 bzero(&args, sizeof(args));
238 ng_tag = (struct ng_ipfw_tag *)m_tag_locate(*m0, NGM_IPFW_COOKIE, 0,
240 if (ng_tag != NULL) {
241 KASSERT(ng_tag->dir == NG_IPFW_OUT,
242 ("ng_ipfw tag with wrong direction"));
243 args.rule = ng_tag->rule;
244 args.rule_id = ng_tag->rule_id;
245 args.chain_id = ng_tag->chain_id;
246 m_tag_delete(*m0, (struct m_tag *)ng_tag);
250 dn_tag = m_tag_find(*m0, PACKET_TAG_DUMMYNET, NULL);
251 if (dn_tag != NULL) {
252 struct dn_pkt_tag *dt;
254 dt = (struct dn_pkt_tag *)(dn_tag+1);
255 args.rule = dt->rule;
256 args.rule_id = dt->rule_id;
257 args.chain_id = dt->chain_id;
259 m_tag_delete(*m0, dn_tag);
267 if (V_fw_one_pass == 0 || args.rule == NULL) {
268 ipfw = ipfw_chk(&args);
273 KASSERT(*m0 != NULL || ipfw == IP_FW_DENY, ("%s: m0 is NULL",
278 if (args.next_hop == NULL)
280 #ifdef IPFIREWALL_FORWARD
281 /* Overwrite existing tag. */
282 fwd_tag = m_tag_find(*m0, PACKET_TAG_IPFORWARD, NULL);
283 if (fwd_tag == NULL) {
284 fwd_tag = m_tag_get(PACKET_TAG_IPFORWARD,
285 sizeof(struct sockaddr_in), M_NOWAIT);
289 m_tag_unlink(*m0, fwd_tag);
290 bcopy(args.next_hop, (fwd_tag+1), sizeof(struct sockaddr_in));
291 m_tag_prepend(*m0, fwd_tag);
293 if (in_localip(args.next_hop->sin_addr))
294 (*m0)->m_flags |= M_FASTFWD_OURS;
297 break; /* not reached */
301 break; /* not reached */
304 if (ip_dn_io_ptr == NULL)
306 if (mtod(*m0, struct ip *)->ip_v == 4)
307 ip_dn_io_ptr(m0, DN_TO_IP_OUT, &args);
308 else if (mtod(*m0, struct ip *)->ip_v == 6)
309 ip_dn_io_ptr(m0, DN_TO_IP6_OUT, &args);
312 return 0; /* packet consumed */
321 divert = ipfw_divert(m0, DIV_DIR_OUT, tee);
324 return 0; /* packet consumed */
327 goto again; /* continue with packet */
333 (void)ng_ipfw_input_p(m0, NG_IPFW_OUT, &args, 1);
334 goto again; /* continue with packet */
339 return ng_ipfw_input_p(m0, NG_IPFW_OUT, &args, 0);
342 goto again; /* continue with packet */
348 KASSERT(0, ("%s: unknown retval", __func__));
357 return 0; /* not filtered */
361 ipfw_divert(struct mbuf **m, int incoming, int tee)
364 * ipfw_chk() has already tagged the packet with the divert tag.
365 * If tee is set, copy packet and return original.
366 * If not tee, consume packet and send it to divert socket.
368 struct mbuf *clone, *reass;
374 /* Is divert module loaded? */
375 if (ip_divert_ptr == NULL)
378 /* Cloning needed for tee? */
380 clone = m_dup(*m, M_DONTWAIT);
384 /* In case m_dup was unable to allocate mbufs. */
389 * Divert listeners can only handle non-fragmented packets.
390 * However when tee is set we will *not* de-fragment the packets;
391 * Doing do would put the reassembly into double-jeopardy. On top
392 * of that someone doing a tee will probably want to get the packet
393 * in its original form.
395 ip = mtod(clone, struct ip *);
396 if (!tee && ip->ip_off & (IP_MF | IP_OFFMASK)) {
398 /* Reassemble packet. */
399 reass = ip_reass(clone);
402 * IP header checksum fixup after reassembly and leave header
403 * in network byte order.
406 ip = mtod(reass, struct ip *);
407 hlen = ip->ip_hl << 2;
408 ip->ip_len = htons(ip->ip_len);
409 ip->ip_off = htons(ip->ip_off);
411 if (hlen == sizeof(struct ip))
412 ip->ip_sum = in_cksum_hdr(ip);
414 ip->ip_sum = in_cksum(reass, hlen);
419 /* Convert header to network byte order. */
420 ip->ip_len = htons(ip->ip_len);
421 ip->ip_off = htons(ip->ip_off);
424 /* Do the dirty job... */
425 if (clone && ip_divert_ptr != NULL)
426 ip_divert_ptr(clone, incoming);
430 * For tee we leave the divert tag attached to original packet.
431 * It will then continue rule evaluation after the tee rule.
436 /* Packet diverted and consumed */
447 struct pfil_head *pfh_inet;
449 pfh_inet = pfil_head_get(PFIL_TYPE_AF, AF_INET);
450 if (pfh_inet == NULL)
453 (void)pfil_add_hook(ipfw_check_in, NULL, PFIL_IN | PFIL_WAITOK,
455 (void)pfil_add_hook(ipfw_check_out, NULL, PFIL_OUT | PFIL_WAITOK,
464 struct pfil_head *pfh_inet;
466 pfh_inet = pfil_head_get(PFIL_TYPE_AF, AF_INET);
467 if (pfh_inet == NULL)
470 (void)pfil_remove_hook(ipfw_check_in, NULL, PFIL_IN | PFIL_WAITOK,
472 (void)pfil_remove_hook(ipfw_check_out, NULL, PFIL_OUT | PFIL_WAITOK,
482 struct pfil_head *pfh_inet6;
484 pfh_inet6 = pfil_head_get(PFIL_TYPE_AF, AF_INET6);
485 if (pfh_inet6 == NULL)
488 (void)pfil_add_hook(ipfw_check_in, NULL, PFIL_IN | PFIL_WAITOK,
490 (void)pfil_add_hook(ipfw_check_out, NULL, PFIL_OUT | PFIL_WAITOK,
499 struct pfil_head *pfh_inet6;
501 pfh_inet6 = pfil_head_get(PFIL_TYPE_AF, AF_INET6);
502 if (pfh_inet6 == NULL)
505 (void)pfil_remove_hook(ipfw_check_in, NULL, PFIL_IN | PFIL_WAITOK,
507 (void)pfil_remove_hook(ipfw_check_out, NULL, PFIL_OUT | PFIL_WAITOK,
515 ipfw_chg_hook(SYSCTL_HANDLER_ARGS)
517 int enable = *(int *)arg1;
520 error = sysctl_handle_int(oidp, &enable, 0, req);
524 enable = (enable) ? 1 : 0;
526 if (enable == *(int *)arg1)
529 if (arg1 == &V_fw_enable) {
533 error = ipfw_unhook();
536 if (arg1 == &V_fw6_enable) {
538 error = ipfw6_hook();
540 error = ipfw6_unhook();
547 *(int *)arg1 = enable;
553 ipfw_modevent(module_t mod, int type, void *unused)
559 if ((err = ipfw_init()) != 0) {
560 printf("ipfw_init() error\n");
563 if ((err = ipfw_hook()) != 0) {
564 printf("ipfw_hook() error\n");
568 if ((err = ipfw6_hook()) != 0) {
569 printf("ipfw_hook() error\n");
576 if ((err = ipfw_unhook()) > 0)
579 if ((err = ipfw6_unhook()) > 0)
592 static moduledata_t ipfwmod = {
597 DECLARE_MODULE(ipfw, ipfwmod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY - 256);
598 MODULE_VERSION(ipfw, 2);