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: head/sys/netinet/ipfw/ip_fw_pfil.c 200601 2009-12-16 10:48:40Z luigi $");
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/sysctl.h>
52 #include <net/route.h>
56 #include <netinet/in.h>
57 #include <netinet/in_systm.h>
58 #include <netinet/ip.h>
59 #include <netinet/ip_var.h>
60 #include <netinet/ip_fw.h>
61 #include <netinet/ipfw/ip_fw_private.h>
62 #include <netinet/ip_dummynet.h>
63 #include <netgraph/ng_ipfw.h>
65 #include <machine/in_cksum.h>
67 static VNET_DEFINE(int, fw_enable) = 1;
68 #define V_fw_enable VNET(fw_enable)
71 static VNET_DEFINE(int, fw6_enable) = 1;
72 #define V_fw6_enable VNET(fw6_enable)
75 int ipfw_chg_hook(SYSCTL_HANDLER_ARGS);
78 void (*ip_divert_ptr)(struct mbuf *m, int incoming);
81 ng_ipfw_input_t *ng_ipfw_input_p = NULL;
83 /* Forward declarations. */
84 static int ipfw_divert(struct mbuf **, int, struct ipfw_rule_ref *, int);
87 SYSCTL_DECL(_net_inet_ip_fw);
88 SYSCTL_VNET_PROC(_net_inet_ip_fw, OID_AUTO, enable,
89 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_enable), 0,
90 ipfw_chg_hook, "I", "Enable ipfw");
92 SYSCTL_DECL(_net_inet6_ip6_fw);
93 SYSCTL_VNET_PROC(_net_inet6_ip6_fw, OID_AUTO, enable,
94 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw6_enable), 0,
95 ipfw_chg_hook, "I", "Enable ipfw+6");
97 #endif /* SYSCTL_NODE */
100 * The pfilter hook to pass packets to ipfw_chk and then to
101 * dummynet, divert, netgraph or other modules.
102 * The packet may be consumed.
105 ipfw_check_hook(void *arg, struct mbuf **m0, struct ifnet *ifp, int dir,
108 struct ip_fw_args args;
113 /* all the processing now uses ip_len in net format */
114 SET_NET_IPLEN(mtod(*m0, struct ip *));
116 /* convert dir to IPFW values */
117 dir = (dir == PFIL_IN) ? DIR_IN : DIR_OUT;
118 bzero(&args, sizeof(args));
122 * extract and remove the tag if present. If we are left
123 * with onepass, optimize the outgoing path.
125 tag = m_tag_locate(*m0, MTAG_IPFW_RULE, 0, NULL);
127 args.rule = *((struct ipfw_rule_ref *)(tag+1));
128 m_tag_delete(*m0, tag);
129 if (args.rule.info & IPFW_ONEPASS) {
130 SET_HOST_IPLEN(mtod(*m0, struct ip *));
136 args.oif = dir == DIR_OUT ? ifp : NULL;
139 ipfw = ipfw_chk(&args);
142 KASSERT(*m0 != NULL || ipfw == IP_FW_DENY, ("%s: m0 is NULL",
145 /* breaking out of the switch means drop */
146 ret = 0; /* default return value for pass */
149 /* next_hop may be set by ipfw_chk */
150 if (args.next_hop == NULL)
152 #ifndef IPFIREWALL_FORWARD
156 struct m_tag *fwd_tag;
158 /* Incoming packets should not be tagged so we do not
159 * m_tag_find. Outgoing packets may be tagged, so we
160 * reuse the tag if present.
162 fwd_tag = (dir == DIR_IN) ? NULL :
163 m_tag_find(*m0, PACKET_TAG_IPFORWARD, NULL);
164 if (fwd_tag != NULL) {
165 m_tag_unlink(*m0, fwd_tag);
167 fwd_tag = m_tag_get(PACKET_TAG_IPFORWARD,
168 sizeof(struct sockaddr_in), M_NOWAIT);
169 if (fwd_tag == NULL) {
171 break; /* i.e. drop */
174 bcopy(args.next_hop, (fwd_tag+1), sizeof(struct sockaddr_in));
175 m_tag_prepend(*m0, fwd_tag);
177 if (in_localip(args.next_hop->sin_addr))
178 (*m0)->m_flags |= M_FASTFWD_OURS;
185 break; /* i.e. drop */
189 if (ip_dn_io_ptr == NULL)
190 break; /* i.e. drop */
191 if (mtod(*m0, struct ip *)->ip_v == 4)
192 ret = ip_dn_io_ptr(m0, dir, &args);
193 else if (mtod(*m0, struct ip *)->ip_v == 6)
194 ret = ip_dn_io_ptr(m0, dir | PROTO_IPV6, &args);
198 * XXX should read the return value.
199 * dummynet normally eats the packet and sets *m0=NULL
200 * unless the packet can be sent immediately. In this
201 * case args is updated and we should re-run the
202 * check without clearing args.
210 if (ip_divert_ptr == NULL) {
212 break; /* i.e. drop */
214 ret = ipfw_divert(m0, dir, &args.rule,
215 (ipfw == IP_FW_TEE) ? 1 : 0);
216 /* continue processing for the original packet (tee). */
223 if (!NG_IPFW_LOADED) {
225 break; /* i.e. drop */
227 ret = ng_ipfw_input_p(m0, dir, &args,
228 (ipfw == IP_FW_NGTEE) ? 1 : 0);
229 if (ipfw == IP_FW_NGTEE) /* ignore errors for NGTEE */
230 goto again; /* continue with packet */
235 goto again; /* continue with packet */
238 KASSERT(0, ("%s: unknown retval", __func__));
247 SET_HOST_IPLEN(mtod(*m0, struct ip *));
251 /* do the divert, return 1 on error 0 on success */
253 ipfw_divert(struct mbuf **m0, int incoming, struct ipfw_rule_ref *rule,
257 * ipfw_chk() has already tagged the packet with the divert tag.
258 * If tee is set, copy packet and return original.
259 * If not tee, consume packet and send it to divert socket.
265 /* Cloning needed for tee? */
267 clone = *m0; /* use the original mbuf */
270 clone = m_dup(*m0, M_DONTWAIT);
271 /* If we cannot duplicate the mbuf, we sacrifice the divert
272 * chain and continue with the tee-ed packet.
279 * Divert listeners can normally handle non-fragmented packets,
280 * but we can only reass in the non-tee case.
281 * This means that listeners on a tee rule may get fragments,
282 * and have to live with that.
283 * Note that we now have the 'reass' ipfw option so if we care
284 * we can do it before a 'tee'.
286 ip = mtod(clone, struct ip *);
287 if (!tee && ntohs(ip->ip_off) & (IP_MF | IP_OFFMASK)) {
291 SET_HOST_IPLEN(ip); /* ip_reass wants host order */
292 reass = ip_reass(clone); /* Reassemble packet. */
294 return 0; /* not an error */
295 /* if reass = NULL then it was consumed by ip_reass */
297 * IP header checksum fixup after reassembly and leave header
298 * in network byte order.
300 ip = mtod(reass, struct ip *);
301 hlen = ip->ip_hl << 2;
304 if (hlen == sizeof(struct ip))
305 ip->ip_sum = in_cksum_hdr(ip);
307 ip->ip_sum = in_cksum(reass, hlen);
310 /* attach a tag to the packet with the reinject info */
311 tag = m_tag_alloc(MTAG_IPFW_RULE, 0,
312 sizeof(struct ipfw_rule_ref), M_NOWAIT);
317 *((struct ipfw_rule_ref *)(tag+1)) = *rule;
318 m_tag_prepend(clone, tag);
320 /* Do the dirty job... */
321 ip_divert_ptr(clone, incoming);
326 * attach or detach hooks for a given protocol family
329 ipfw_hook(int onoff, int pf)
331 struct pfil_head *pfh;
333 pfh = pfil_head_get(PFIL_TYPE_AF, pf);
337 (void) (onoff ? pfil_add_hook : pfil_remove_hook)
338 (ipfw_check_hook, NULL, PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh);
344 ipfw_attach_hooks(int arg)
348 if (arg == 0) /* detach */
349 ipfw_hook(0, AF_INET);
350 else if (V_fw_enable && ipfw_hook(1, AF_INET) != 0) {
351 error = ENOENT; /* see ip_fw_pfil.c::ipfw_hook() */
352 printf("ipfw_hook() error\n");
355 if (arg == 0) /* detach */
356 ipfw_hook(0, AF_INET6);
357 else if (V_fw6_enable && ipfw_hook(1, AF_INET6) != 0) {
359 printf("ipfw6_hook() error\n");
366 ipfw_chg_hook(SYSCTL_HANDLER_ARGS)
373 if (arg1 == &VNET_NAME(fw_enable)) {
374 enable = V_fw_enable;
378 else if (arg1 == &VNET_NAME(fw6_enable)) {
379 enable = V_fw6_enable;
388 error = sysctl_handle_int(oidp, &enable, 0, req);
393 enable = (enable) ? 1 : 0;
395 if (enable == oldenable)
398 error = ipfw_hook(enable, af);
402 V_fw_enable = enable;
404 else if (af == AF_INET6)
405 V_fw6_enable = enable;