1/*
2 * Copyright (c) 1982, 1986, 1988, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
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.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94
| 1/*
2 * Copyright (c) 1982, 1986, 1988, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
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.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94
|
34 * $FreeBSD: head/sys/netinet/ip_input.c 122334 2003-11-08 23:36:32Z sam $
| 34 * $FreeBSD: head/sys/netinet/ip_input.c 122702 2003-11-14 21:02:22Z andre $
|
35 */
36
37#include "opt_bootp.h"
38#include "opt_ipfw.h"
39#include "opt_ipdn.h"
40#include "opt_ipdivert.h"
41#include "opt_ipfilter.h"
42#include "opt_ipstealth.h"
43#include "opt_ipsec.h"
44#include "opt_mac.h"
45#include "opt_pfil_hooks.h"
46#include "opt_random_ip_id.h"
47
48#include <sys/param.h>
49#include <sys/systm.h>
50#include <sys/mac.h>
51#include <sys/mbuf.h>
52#include <sys/malloc.h>
53#include <sys/domain.h>
54#include <sys/protosw.h>
55#include <sys/socket.h>
56#include <sys/time.h>
57#include <sys/kernel.h>
58#include <sys/syslog.h>
59#include <sys/sysctl.h>
60
61#include <net/pfil.h>
62#include <net/if.h>
63#include <net/if_types.h>
64#include <net/if_var.h>
65#include <net/if_dl.h>
66#include <net/route.h>
67#include <net/netisr.h>
68
69#include <netinet/in.h>
70#include <netinet/in_systm.h>
71#include <netinet/in_var.h>
72#include <netinet/ip.h>
73#include <netinet/in_pcb.h>
74#include <netinet/ip_var.h>
75#include <netinet/ip_icmp.h>
76#include <machine/in_cksum.h>
77
78#include <sys/socketvar.h>
79
80#include <netinet/ip_fw.h>
81#include <netinet/ip_dummynet.h>
82
83#ifdef IPSEC
84#include <netinet6/ipsec.h>
85#include <netkey/key.h>
86#endif
87
88#ifdef FAST_IPSEC
89#include <netipsec/ipsec.h>
90#include <netipsec/key.h>
91#endif
92
93int rsvp_on = 0;
94
95int ipforwarding = 0;
96SYSCTL_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_RW,
97 &ipforwarding, 0, "Enable IP forwarding between interfaces");
98
99static int ipsendredirects = 1; /* XXX */
100SYSCTL_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_RW,
101 &ipsendredirects, 0, "Enable sending IP redirects");
102
103int ip_defttl = IPDEFTTL;
104SYSCTL_INT(_net_inet_ip, IPCTL_DEFTTL, ttl, CTLFLAG_RW,
105 &ip_defttl, 0, "Maximum TTL on IP packets");
106
107static int ip_dosourceroute = 0;
108SYSCTL_INT(_net_inet_ip, IPCTL_SOURCEROUTE, sourceroute, CTLFLAG_RW,
109 &ip_dosourceroute, 0, "Enable forwarding source routed IP packets");
110
111static int ip_acceptsourceroute = 0;
112SYSCTL_INT(_net_inet_ip, IPCTL_ACCEPTSOURCEROUTE, accept_sourceroute,
113 CTLFLAG_RW, &ip_acceptsourceroute, 0,
114 "Enable accepting source routed IP packets");
115
116static int ip_keepfaith = 0;
117SYSCTL_INT(_net_inet_ip, IPCTL_KEEPFAITH, keepfaith, CTLFLAG_RW,
118 &ip_keepfaith, 0,
119 "Enable packet capture for FAITH IPv4->IPv6 translater daemon");
120
121static int nipq = 0; /* total # of reass queues */
122static int maxnipq;
123SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragpackets, CTLFLAG_RW,
124 &maxnipq, 0,
125 "Maximum number of IPv4 fragment reassembly queue entries");
126
127static int maxfragsperpacket;
128SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragsperpacket, CTLFLAG_RW,
129 &maxfragsperpacket, 0,
130 "Maximum number of IPv4 fragments allowed per packet");
131
132static int ip_sendsourcequench = 0;
133SYSCTL_INT(_net_inet_ip, OID_AUTO, sendsourcequench, CTLFLAG_RW,
134 &ip_sendsourcequench, 0,
135 "Enable the transmission of source quench packets");
136
137/*
138 * XXX - Setting ip_checkinterface mostly implements the receive side of
139 * the Strong ES model described in RFC 1122, but since the routing table
140 * and transmit implementation do not implement the Strong ES model,
141 * setting this to 1 results in an odd hybrid.
142 *
143 * XXX - ip_checkinterface currently must be disabled if you use ipnat
144 * to translate the destination address to another local interface.
145 *
146 * XXX - ip_checkinterface must be disabled if you add IP aliases
147 * to the loopback interface instead of the interface where the
148 * packets for those addresses are received.
149 */
150static int ip_checkinterface = 1;
151SYSCTL_INT(_net_inet_ip, OID_AUTO, check_interface, CTLFLAG_RW,
152 &ip_checkinterface, 0, "Verify packet arrives on correct interface");
153
154#ifdef DIAGNOSTIC
155static int ipprintfs = 0;
156#endif
157#ifdef PFIL_HOOKS
158struct pfil_head inet_pfil_hook;
159#endif
160
161static struct ifqueue ipintrq;
162static int ipqmaxlen = IFQ_MAXLEN;
163
164extern struct domain inetdomain;
165extern struct protosw inetsw[];
166u_char ip_protox[IPPROTO_MAX];
167struct in_ifaddrhead in_ifaddrhead; /* first inet address */
168struct in_ifaddrhashhead *in_ifaddrhashtbl; /* inet addr hash table */
169u_long in_ifaddrhmask; /* mask for hash table */
170
171SYSCTL_INT(_net_inet_ip, IPCTL_INTRQMAXLEN, intr_queue_maxlen, CTLFLAG_RW,
172 &ipintrq.ifq_maxlen, 0, "Maximum size of the IP input queue");
173SYSCTL_INT(_net_inet_ip, IPCTL_INTRQDROPS, intr_queue_drops, CTLFLAG_RD,
174 &ipintrq.ifq_drops, 0, "Number of packets dropped from the IP input queue");
175
176struct ipstat ipstat;
177SYSCTL_STRUCT(_net_inet_ip, IPCTL_STATS, stats, CTLFLAG_RW,
178 &ipstat, ipstat, "IP statistics (struct ipstat, netinet/ip_var.h)");
179
180/* Packet reassembly stuff */
181#define IPREASS_NHASH_LOG2 6
182#define IPREASS_NHASH (1 << IPREASS_NHASH_LOG2)
183#define IPREASS_HMASK (IPREASS_NHASH - 1)
184#define IPREASS_HASH(x,y) \
185 (((((x) & 0xF) | ((((x) >> 8) & 0xF) << 4)) ^ (y)) & IPREASS_HMASK)
186
187static TAILQ_HEAD(ipqhead, ipq) ipq[IPREASS_NHASH];
188struct mtx ipqlock;
189
190#define IPQ_LOCK() mtx_lock(&ipqlock)
191#define IPQ_UNLOCK() mtx_unlock(&ipqlock)
192#define IPQ_LOCK_INIT() mtx_init(&ipqlock, "ipqlock", NULL, MTX_DEF)
193#define IPQ_LOCK_ASSERT() mtx_assert(&ipqlock, MA_OWNED)
194
195#ifdef IPCTL_DEFMTU
196SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW,
197 &ip_mtu, 0, "Default MTU");
198#endif
199
200#ifdef IPSTEALTH
201static int ipstealth = 0;
202SYSCTL_INT(_net_inet_ip, OID_AUTO, stealth, CTLFLAG_RW,
203 &ipstealth, 0, "");
204#endif
205
206
207/* Firewall hooks */
208ip_fw_chk_t *ip_fw_chk_ptr;
209int fw_enable = 1 ;
210int fw_one_pass = 1;
211
212/* Dummynet hooks */
213ip_dn_io_t *ip_dn_io_ptr;
214
215/*
216 * One deep route cache for ip forwarding. This is done
217 * very inefficiently. We don't care as it's about to be
218 * replaced by something better.
219 */
220static struct rtcache {
221 struct route rc_ro; /* most recently used route */
222 struct mtx rc_mtx; /* update lock for cache */
223} ip_fwdcache;
224
225#define RTCACHE_LOCK() mtx_lock(&ip_fwdcache.rc_mtx)
226#define RTCACHE_UNLOCK() mtx_unlock(&ip_fwdcache.rc_mtx)
227#define RTCACHE_LOCK_INIT() \
228 mtx_init(&ip_fwdcache.rc_mtx, "route cache", NULL, MTX_DEF)
229#define RTCACHE_LOCK_ASSERT() mtx_assert(&ip_fwdcache.rc_mtx, MA_OWNED)
230
231/*
232 * Get a copy of the current route cache contents.
233 */
234#define RTCACHE_GET(_ro) do { \
235 struct rtentry *rt; \
236 RTCACHE_LOCK(); \
237 *(_ro) = ip_fwdcache.rc_ro; \
238 if ((rt = (_ro)->ro_rt) != NULL) { \
239 RT_LOCK(rt); \
240 RT_ADDREF(rt); \
241 RT_UNLOCK(rt); \
242 } \
243 RTCACHE_UNLOCK(); \
244} while (0)
245
246/*
247 * Update the cache contents.
248 */
249#define RTCACHE_UPDATE(_ro) do { \
250 struct rtentry *rt; \
251 RTCACHE_LOCK(); \
252 rt = ip_fwdcache.rc_ro.ro_rt; \
253 if ((_ro)->ro_rt != rt) { \
254 ip_fwdcache.rc_ro = *(_ro); \
255 if (rt) \
256 RTFREE(rt); \
257 } \
258 RTCACHE_UNLOCK(); \
259} while (0)
260
261/*
262 * XXX this is ugly -- the following two global variables are
263 * used to store packet state while it travels through the stack.
264 * Note that the code even makes assumptions on the size and
265 * alignment of fields inside struct ip_srcrt so e.g. adding some
266 * fields will break the code. This needs to be fixed.
267 *
268 * We need to save the IP options in case a protocol wants to respond
269 * to an incoming packet over the same route if the packet got here
270 * using IP source routing. This allows connection establishment and
271 * maintenance when the remote end is on a network that is not known
272 * to us.
273 */
274static int ip_nhops = 0;
275static struct ip_srcrt {
276 struct in_addr dst; /* final destination */
277 char nop; /* one NOP to align */
278 char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */
279 struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
280} ip_srcrt;
281
282static void save_rte(u_char *, struct in_addr);
283static int ip_dooptions(struct mbuf *m, int,
284 struct sockaddr_in *next_hop);
285static void ip_forward(struct mbuf *m, struct route *, int srcrt,
286 struct sockaddr_in *next_hop);
287static void ip_freef(struct ipqhead *, struct ipq *);
288static struct mbuf *ip_reass(struct mbuf *, struct ipqhead *,
289 struct ipq *, u_int32_t *, u_int16_t *);
290
291/*
292 * IP initialization: fill in IP protocol switch table.
293 * All protocols not implemented in kernel go to raw IP protocol handler.
294 */
295void
296ip_init()
297{
298 register struct protosw *pr;
299 register int i;
300
301 TAILQ_INIT(&in_ifaddrhead);
302 in_ifaddrhashtbl = hashinit(INADDR_NHASH, M_IFADDR, &in_ifaddrhmask);
303 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
304 if (pr == 0)
305 panic("ip_init");
306 for (i = 0; i < IPPROTO_MAX; i++)
307 ip_protox[i] = pr - inetsw;
308 for (pr = inetdomain.dom_protosw;
309 pr < inetdomain.dom_protoswNPROTOSW; pr++)
310 if (pr->pr_domain->dom_family == PF_INET &&
311 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
312 ip_protox[pr->pr_protocol] = pr - inetsw;
313
314#ifdef PFIL_HOOKS
315 inet_pfil_hook.ph_type = PFIL_TYPE_AF;
316 inet_pfil_hook.ph_af = AF_INET;
317 if ((i = pfil_head_register(&inet_pfil_hook)) != 0)
318 printf("%s: WARNING: unable to register pfil hook, "
319 "error %d\n", __func__, i);
320#endif /* PFIL_HOOKS */
321
322 IPQ_LOCK_INIT();
323 for (i = 0; i < IPREASS_NHASH; i++)
324 TAILQ_INIT(&ipq[i]);
325
326 bzero(&ip_fwdcache, sizeof(ip_fwdcache));
327 RTCACHE_LOCK_INIT();
328
329 maxnipq = nmbclusters / 32;
330 maxfragsperpacket = 16;
331
332#ifndef RANDOM_IP_ID
333 ip_id = time_second & 0xffff;
334#endif
335 ipintrq.ifq_maxlen = ipqmaxlen;
336 mtx_init(&ipintrq.ifq_mtx, "ip_inq", NULL, MTX_DEF);
337 netisr_register(NETISR_IP, ip_input, &ipintrq, NETISR_MPSAFE);
338}
339
340/*
341 * Invalidate any cached route used for forwarding.
342 */
343void
344ip_forward_cacheinval(void)
345{
346 struct rtentry *rt;
347
348 RTCACHE_LOCK();
349 rt = ip_fwdcache.rc_ro.ro_rt;
350 ip_fwdcache.rc_ro.ro_rt = 0;
351 if (rt != NULL)
352 RTFREE(rt);
353 RTCACHE_UNLOCK();
354}
355
356/*
357 * Ip input routine. Checksum and byte swap header. If fragmented
358 * try to reassemble. Process options. Pass to next level.
359 */
360void
361ip_input(struct mbuf *m)
362{
| 35 */
36
37#include "opt_bootp.h"
38#include "opt_ipfw.h"
39#include "opt_ipdn.h"
40#include "opt_ipdivert.h"
41#include "opt_ipfilter.h"
42#include "opt_ipstealth.h"
43#include "opt_ipsec.h"
44#include "opt_mac.h"
45#include "opt_pfil_hooks.h"
46#include "opt_random_ip_id.h"
47
48#include <sys/param.h>
49#include <sys/systm.h>
50#include <sys/mac.h>
51#include <sys/mbuf.h>
52#include <sys/malloc.h>
53#include <sys/domain.h>
54#include <sys/protosw.h>
55#include <sys/socket.h>
56#include <sys/time.h>
57#include <sys/kernel.h>
58#include <sys/syslog.h>
59#include <sys/sysctl.h>
60
61#include <net/pfil.h>
62#include <net/if.h>
63#include <net/if_types.h>
64#include <net/if_var.h>
65#include <net/if_dl.h>
66#include <net/route.h>
67#include <net/netisr.h>
68
69#include <netinet/in.h>
70#include <netinet/in_systm.h>
71#include <netinet/in_var.h>
72#include <netinet/ip.h>
73#include <netinet/in_pcb.h>
74#include <netinet/ip_var.h>
75#include <netinet/ip_icmp.h>
76#include <machine/in_cksum.h>
77
78#include <sys/socketvar.h>
79
80#include <netinet/ip_fw.h>
81#include <netinet/ip_dummynet.h>
82
83#ifdef IPSEC
84#include <netinet6/ipsec.h>
85#include <netkey/key.h>
86#endif
87
88#ifdef FAST_IPSEC
89#include <netipsec/ipsec.h>
90#include <netipsec/key.h>
91#endif
92
93int rsvp_on = 0;
94
95int ipforwarding = 0;
96SYSCTL_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_RW,
97 &ipforwarding, 0, "Enable IP forwarding between interfaces");
98
99static int ipsendredirects = 1; /* XXX */
100SYSCTL_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_RW,
101 &ipsendredirects, 0, "Enable sending IP redirects");
102
103int ip_defttl = IPDEFTTL;
104SYSCTL_INT(_net_inet_ip, IPCTL_DEFTTL, ttl, CTLFLAG_RW,
105 &ip_defttl, 0, "Maximum TTL on IP packets");
106
107static int ip_dosourceroute = 0;
108SYSCTL_INT(_net_inet_ip, IPCTL_SOURCEROUTE, sourceroute, CTLFLAG_RW,
109 &ip_dosourceroute, 0, "Enable forwarding source routed IP packets");
110
111static int ip_acceptsourceroute = 0;
112SYSCTL_INT(_net_inet_ip, IPCTL_ACCEPTSOURCEROUTE, accept_sourceroute,
113 CTLFLAG_RW, &ip_acceptsourceroute, 0,
114 "Enable accepting source routed IP packets");
115
116static int ip_keepfaith = 0;
117SYSCTL_INT(_net_inet_ip, IPCTL_KEEPFAITH, keepfaith, CTLFLAG_RW,
118 &ip_keepfaith, 0,
119 "Enable packet capture for FAITH IPv4->IPv6 translater daemon");
120
121static int nipq = 0; /* total # of reass queues */
122static int maxnipq;
123SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragpackets, CTLFLAG_RW,
124 &maxnipq, 0,
125 "Maximum number of IPv4 fragment reassembly queue entries");
126
127static int maxfragsperpacket;
128SYSCTL_INT(_net_inet_ip, OID_AUTO, maxfragsperpacket, CTLFLAG_RW,
129 &maxfragsperpacket, 0,
130 "Maximum number of IPv4 fragments allowed per packet");
131
132static int ip_sendsourcequench = 0;
133SYSCTL_INT(_net_inet_ip, OID_AUTO, sendsourcequench, CTLFLAG_RW,
134 &ip_sendsourcequench, 0,
135 "Enable the transmission of source quench packets");
136
137/*
138 * XXX - Setting ip_checkinterface mostly implements the receive side of
139 * the Strong ES model described in RFC 1122, but since the routing table
140 * and transmit implementation do not implement the Strong ES model,
141 * setting this to 1 results in an odd hybrid.
142 *
143 * XXX - ip_checkinterface currently must be disabled if you use ipnat
144 * to translate the destination address to another local interface.
145 *
146 * XXX - ip_checkinterface must be disabled if you add IP aliases
147 * to the loopback interface instead of the interface where the
148 * packets for those addresses are received.
149 */
150static int ip_checkinterface = 1;
151SYSCTL_INT(_net_inet_ip, OID_AUTO, check_interface, CTLFLAG_RW,
152 &ip_checkinterface, 0, "Verify packet arrives on correct interface");
153
154#ifdef DIAGNOSTIC
155static int ipprintfs = 0;
156#endif
157#ifdef PFIL_HOOKS
158struct pfil_head inet_pfil_hook;
159#endif
160
161static struct ifqueue ipintrq;
162static int ipqmaxlen = IFQ_MAXLEN;
163
164extern struct domain inetdomain;
165extern struct protosw inetsw[];
166u_char ip_protox[IPPROTO_MAX];
167struct in_ifaddrhead in_ifaddrhead; /* first inet address */
168struct in_ifaddrhashhead *in_ifaddrhashtbl; /* inet addr hash table */
169u_long in_ifaddrhmask; /* mask for hash table */
170
171SYSCTL_INT(_net_inet_ip, IPCTL_INTRQMAXLEN, intr_queue_maxlen, CTLFLAG_RW,
172 &ipintrq.ifq_maxlen, 0, "Maximum size of the IP input queue");
173SYSCTL_INT(_net_inet_ip, IPCTL_INTRQDROPS, intr_queue_drops, CTLFLAG_RD,
174 &ipintrq.ifq_drops, 0, "Number of packets dropped from the IP input queue");
175
176struct ipstat ipstat;
177SYSCTL_STRUCT(_net_inet_ip, IPCTL_STATS, stats, CTLFLAG_RW,
178 &ipstat, ipstat, "IP statistics (struct ipstat, netinet/ip_var.h)");
179
180/* Packet reassembly stuff */
181#define IPREASS_NHASH_LOG2 6
182#define IPREASS_NHASH (1 << IPREASS_NHASH_LOG2)
183#define IPREASS_HMASK (IPREASS_NHASH - 1)
184#define IPREASS_HASH(x,y) \
185 (((((x) & 0xF) | ((((x) >> 8) & 0xF) << 4)) ^ (y)) & IPREASS_HMASK)
186
187static TAILQ_HEAD(ipqhead, ipq) ipq[IPREASS_NHASH];
188struct mtx ipqlock;
189
190#define IPQ_LOCK() mtx_lock(&ipqlock)
191#define IPQ_UNLOCK() mtx_unlock(&ipqlock)
192#define IPQ_LOCK_INIT() mtx_init(&ipqlock, "ipqlock", NULL, MTX_DEF)
193#define IPQ_LOCK_ASSERT() mtx_assert(&ipqlock, MA_OWNED)
194
195#ifdef IPCTL_DEFMTU
196SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW,
197 &ip_mtu, 0, "Default MTU");
198#endif
199
200#ifdef IPSTEALTH
201static int ipstealth = 0;
202SYSCTL_INT(_net_inet_ip, OID_AUTO, stealth, CTLFLAG_RW,
203 &ipstealth, 0, "");
204#endif
205
206
207/* Firewall hooks */
208ip_fw_chk_t *ip_fw_chk_ptr;
209int fw_enable = 1 ;
210int fw_one_pass = 1;
211
212/* Dummynet hooks */
213ip_dn_io_t *ip_dn_io_ptr;
214
215/*
216 * One deep route cache for ip forwarding. This is done
217 * very inefficiently. We don't care as it's about to be
218 * replaced by something better.
219 */
220static struct rtcache {
221 struct route rc_ro; /* most recently used route */
222 struct mtx rc_mtx; /* update lock for cache */
223} ip_fwdcache;
224
225#define RTCACHE_LOCK() mtx_lock(&ip_fwdcache.rc_mtx)
226#define RTCACHE_UNLOCK() mtx_unlock(&ip_fwdcache.rc_mtx)
227#define RTCACHE_LOCK_INIT() \
228 mtx_init(&ip_fwdcache.rc_mtx, "route cache", NULL, MTX_DEF)
229#define RTCACHE_LOCK_ASSERT() mtx_assert(&ip_fwdcache.rc_mtx, MA_OWNED)
230
231/*
232 * Get a copy of the current route cache contents.
233 */
234#define RTCACHE_GET(_ro) do { \
235 struct rtentry *rt; \
236 RTCACHE_LOCK(); \
237 *(_ro) = ip_fwdcache.rc_ro; \
238 if ((rt = (_ro)->ro_rt) != NULL) { \
239 RT_LOCK(rt); \
240 RT_ADDREF(rt); \
241 RT_UNLOCK(rt); \
242 } \
243 RTCACHE_UNLOCK(); \
244} while (0)
245
246/*
247 * Update the cache contents.
248 */
249#define RTCACHE_UPDATE(_ro) do { \
250 struct rtentry *rt; \
251 RTCACHE_LOCK(); \
252 rt = ip_fwdcache.rc_ro.ro_rt; \
253 if ((_ro)->ro_rt != rt) { \
254 ip_fwdcache.rc_ro = *(_ro); \
255 if (rt) \
256 RTFREE(rt); \
257 } \
258 RTCACHE_UNLOCK(); \
259} while (0)
260
261/*
262 * XXX this is ugly -- the following two global variables are
263 * used to store packet state while it travels through the stack.
264 * Note that the code even makes assumptions on the size and
265 * alignment of fields inside struct ip_srcrt so e.g. adding some
266 * fields will break the code. This needs to be fixed.
267 *
268 * We need to save the IP options in case a protocol wants to respond
269 * to an incoming packet over the same route if the packet got here
270 * using IP source routing. This allows connection establishment and
271 * maintenance when the remote end is on a network that is not known
272 * to us.
273 */
274static int ip_nhops = 0;
275static struct ip_srcrt {
276 struct in_addr dst; /* final destination */
277 char nop; /* one NOP to align */
278 char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */
279 struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
280} ip_srcrt;
281
282static void save_rte(u_char *, struct in_addr);
283static int ip_dooptions(struct mbuf *m, int,
284 struct sockaddr_in *next_hop);
285static void ip_forward(struct mbuf *m, struct route *, int srcrt,
286 struct sockaddr_in *next_hop);
287static void ip_freef(struct ipqhead *, struct ipq *);
288static struct mbuf *ip_reass(struct mbuf *, struct ipqhead *,
289 struct ipq *, u_int32_t *, u_int16_t *);
290
291/*
292 * IP initialization: fill in IP protocol switch table.
293 * All protocols not implemented in kernel go to raw IP protocol handler.
294 */
295void
296ip_init()
297{
298 register struct protosw *pr;
299 register int i;
300
301 TAILQ_INIT(&in_ifaddrhead);
302 in_ifaddrhashtbl = hashinit(INADDR_NHASH, M_IFADDR, &in_ifaddrhmask);
303 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
304 if (pr == 0)
305 panic("ip_init");
306 for (i = 0; i < IPPROTO_MAX; i++)
307 ip_protox[i] = pr - inetsw;
308 for (pr = inetdomain.dom_protosw;
309 pr < inetdomain.dom_protoswNPROTOSW; pr++)
310 if (pr->pr_domain->dom_family == PF_INET &&
311 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
312 ip_protox[pr->pr_protocol] = pr - inetsw;
313
314#ifdef PFIL_HOOKS
315 inet_pfil_hook.ph_type = PFIL_TYPE_AF;
316 inet_pfil_hook.ph_af = AF_INET;
317 if ((i = pfil_head_register(&inet_pfil_hook)) != 0)
318 printf("%s: WARNING: unable to register pfil hook, "
319 "error %d\n", __func__, i);
320#endif /* PFIL_HOOKS */
321
322 IPQ_LOCK_INIT();
323 for (i = 0; i < IPREASS_NHASH; i++)
324 TAILQ_INIT(&ipq[i]);
325
326 bzero(&ip_fwdcache, sizeof(ip_fwdcache));
327 RTCACHE_LOCK_INIT();
328
329 maxnipq = nmbclusters / 32;
330 maxfragsperpacket = 16;
331
332#ifndef RANDOM_IP_ID
333 ip_id = time_second & 0xffff;
334#endif
335 ipintrq.ifq_maxlen = ipqmaxlen;
336 mtx_init(&ipintrq.ifq_mtx, "ip_inq", NULL, MTX_DEF);
337 netisr_register(NETISR_IP, ip_input, &ipintrq, NETISR_MPSAFE);
338}
339
340/*
341 * Invalidate any cached route used for forwarding.
342 */
343void
344ip_forward_cacheinval(void)
345{
346 struct rtentry *rt;
347
348 RTCACHE_LOCK();
349 rt = ip_fwdcache.rc_ro.ro_rt;
350 ip_fwdcache.rc_ro.ro_rt = 0;
351 if (rt != NULL)
352 RTFREE(rt);
353 RTCACHE_UNLOCK();
354}
355
356/*
357 * Ip input routine. Checksum and byte swap header. If fragmented
358 * try to reassemble. Process options. Pass to next level.
359 */
360void
361ip_input(struct mbuf *m)
362{
|
363 struct ip *ip;
| 363 struct ip *ip = NULL;
|
364 struct ipq *fp;
365 struct in_ifaddr *ia = NULL;
366 struct ifaddr *ifa;
| 364 struct ipq *fp;
365 struct in_ifaddr *ia = NULL;
366 struct ifaddr *ifa;
|
367 int i, hlen, checkif;
| 367 int i, checkif, hlen = 0;
368 int ours = 0;
|
368 u_short sum;
369 struct in_addr pkt_dst;
370 u_int32_t divert_info = 0; /* packet divert/tee info */
371 struct ip_fw_args args;
372 struct route cro; /* copy of cached route */
373 int srcrt = 0; /* forward by ``src routing'' */
374#ifdef PFIL_HOOKS
375 struct in_addr odst; /* original dst address */
376#endif
377#ifdef FAST_IPSEC
378 struct m_tag *mtag;
379 struct tdb_ident *tdbi;
380 struct secpolicy *sp;
381 int s, error;
382#endif /* FAST_IPSEC */
383
384 args.eh = NULL;
385 args.oif = NULL;
386 args.rule = NULL;
387 args.divert_rule = 0; /* divert cookie */
388 args.next_hop = NULL;
389
| 369 u_short sum;
370 struct in_addr pkt_dst;
371 u_int32_t divert_info = 0; /* packet divert/tee info */
372 struct ip_fw_args args;
373 struct route cro; /* copy of cached route */
374 int srcrt = 0; /* forward by ``src routing'' */
375#ifdef PFIL_HOOKS
376 struct in_addr odst; /* original dst address */
377#endif
378#ifdef FAST_IPSEC
379 struct m_tag *mtag;
380 struct tdb_ident *tdbi;
381 struct secpolicy *sp;
382 int s, error;
383#endif /* FAST_IPSEC */
384
385 args.eh = NULL;
386 args.oif = NULL;
387 args.rule = NULL;
388 args.divert_rule = 0; /* divert cookie */
389 args.next_hop = NULL;
390
|
390 /* Grab info from MT_TAG mbufs prepended to the chain. */
391 for (; m && m->m_type == MT_TAG; m = m->m_next) {
| 391 /*
392 * Grab info from MT_TAG mbufs prepended to the chain.
393 *
394 * XXX: This is ugly. These pseudo mbuf prepend tags should really
395 * be real m_tags. Before these have always been allocated on the
396 * callers stack, so we didn't have to free them. Now with
397 * ip_fastforward they are true mbufs and we have to free them
398 * otherwise we have a leak. Must rewrite ipfw to use m_tags.
399 */
400 for (; m && m->m_type == MT_TAG;) {
401 struct mbuf *m0;
402
|
392 switch(m->_m_tag_id) {
393 default:
394 printf("ip_input: unrecognised MT_TAG tag %d\n",
395 m->_m_tag_id);
396 break;
397
398 case PACKET_TAG_DUMMYNET:
399 args.rule = ((struct dn_pkt *)m)->rule;
400 break;
401
402 case PACKET_TAG_DIVERT:
403 args.divert_rule = (intptr_t)m->m_hdr.mh_data & 0xffff;
404 break;
405
406 case PACKET_TAG_IPFORWARD:
407 args.next_hop = (struct sockaddr_in *)m->m_hdr.mh_data;
408 break;
| 403 switch(m->_m_tag_id) {
404 default:
405 printf("ip_input: unrecognised MT_TAG tag %d\n",
406 m->_m_tag_id);
407 break;
408
409 case PACKET_TAG_DUMMYNET:
410 args.rule = ((struct dn_pkt *)m)->rule;
411 break;
412
413 case PACKET_TAG_DIVERT:
414 args.divert_rule = (intptr_t)m->m_hdr.mh_data & 0xffff;
415 break;
416
417 case PACKET_TAG_IPFORWARD:
418 args.next_hop = (struct sockaddr_in *)m->m_hdr.mh_data;
419 break;
|
| 420
421 case PACKET_TAG_IPFASTFWD_OURS:
422 ours = 1;
423 break;
|
409 }
| 424 }
|
| 425
426 m0 = m;
427 m = m->m_next;
428 /* XXX: This is set by ip_fastforward */
429 if (m0->m_nextpkt == (struct mbuf *)1)
430 m_free(m0);
|
410 }
411
412 M_ASSERTPKTHDR(m);
413
| 431 }
432
433 M_ASSERTPKTHDR(m);
434
|
| 435 if (ours) /* ip_fastforward firewall changed dest to local */
436 goto ours;
437
|
414 if (args.rule) { /* dummynet already filtered us */
415 ip = mtod(m, struct ip *);
416 hlen = ip->ip_hl << 2;
417 goto iphack ;
418 }
419
420 ipstat.ips_total++;
421
422 if (m->m_pkthdr.len < sizeof(struct ip))
423 goto tooshort;
424
425 if (m->m_len < sizeof (struct ip) &&
426 (m = m_pullup(m, sizeof (struct ip))) == 0) {
427 ipstat.ips_toosmall++;
428 return;
429 }
430 ip = mtod(m, struct ip *);
431
432 if (ip->ip_v != IPVERSION) {
433 ipstat.ips_badvers++;
434 goto bad;
435 }
436
437 hlen = ip->ip_hl << 2;
438 if (hlen < sizeof(struct ip)) { /* minimum header length */
439 ipstat.ips_badhlen++;
440 goto bad;
441 }
442 if (hlen > m->m_len) {
443 if ((m = m_pullup(m, hlen)) == 0) {
444 ipstat.ips_badhlen++;
445 return;
446 }
447 ip = mtod(m, struct ip *);
448 }
449
450 /* 127/8 must not appear on wire - RFC1122 */
451 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
452 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
453 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) {
454 ipstat.ips_badaddr++;
455 goto bad;
456 }
457 }
458
459 if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
460 sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID);
461 } else {
462 if (hlen == sizeof(struct ip)) {
463 sum = in_cksum_hdr(ip);
464 } else {
465 sum = in_cksum(m, hlen);
466 }
467 }
468 if (sum) {
469 ipstat.ips_badsum++;
470 goto bad;
471 }
472
473 /*
474 * Convert fields to host representation.
475 */
476 ip->ip_len = ntohs(ip->ip_len);
477 if (ip->ip_len < hlen) {
478 ipstat.ips_badlen++;
479 goto bad;
480 }
481 ip->ip_off = ntohs(ip->ip_off);
482
483 /*
484 * Check that the amount of data in the buffers
485 * is as at least much as the IP header would have us expect.
486 * Trim mbufs if longer than we expect.
487 * Drop packet if shorter than we expect.
488 */
489 if (m->m_pkthdr.len < ip->ip_len) {
490tooshort:
491 ipstat.ips_tooshort++;
492 goto bad;
493 }
494 if (m->m_pkthdr.len > ip->ip_len) {
495 if (m->m_len == m->m_pkthdr.len) {
496 m->m_len = ip->ip_len;
497 m->m_pkthdr.len = ip->ip_len;
498 } else
499 m_adj(m, ip->ip_len - m->m_pkthdr.len);
500 }
501#if defined(IPSEC) && !defined(IPSEC_FILTERGIF)
502 /*
503 * Bypass packet filtering for packets from a tunnel (gif).
504 */
505 if (ipsec_getnhist(m))
506 goto pass;
507#endif
508#if defined(FAST_IPSEC) && !defined(IPSEC_FILTERGIF)
509 /*
510 * Bypass packet filtering for packets from a tunnel (gif).
511 */
512 if (m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL)
513 goto pass;
514#endif
515
516 /*
517 * IpHack's section.
518 * Right now when no processing on packet has done
519 * and it is still fresh out of network we do our black
520 * deals with it.
521 * - Firewall: deny/allow/divert
522 * - Xlate: translate packet's addr/port (NAT).
523 * - Pipe: pass pkt through dummynet.
524 * - Wrap: fake packet's addr/port <unimpl.>
525 * - Encapsulate: put it in another IP and send out. <unimp.>
526 */
527
528iphack:
529
530#ifdef PFIL_HOOKS
531 /*
532 * Run through list of hooks for input packets.
533 *
534 * NB: Beware of the destination address changing (e.g.
535 * by NAT rewriting). When this happens, tell
536 * ip_forward to do the right thing.
537 */
538 odst = ip->ip_dst;
539 if (pfil_run_hooks(&inet_pfil_hook, &m, m->m_pkthdr.rcvif,
540 PFIL_IN) != 0)
541 return;
542 if (m == NULL) /* consumed by filter */
543 return;
544 ip = mtod(m, struct ip *);
545 srcrt = (odst.s_addr != ip->ip_dst.s_addr);
546#endif /* PFIL_HOOKS */
547
548 if (fw_enable && IPFW_LOADED) {
549 /*
550 * If we've been forwarded from the output side, then
551 * skip the firewall a second time
552 */
553 if (args.next_hop)
554 goto ours;
555
556 args.m = m;
557 i = ip_fw_chk_ptr(&args);
558 m = args.m;
559
560 if ( (i & IP_FW_PORT_DENY_FLAG) || m == NULL) { /* drop */
561 if (m)
562 m_freem(m);
563 return;
564 }
565 ip = mtod(m, struct ip *); /* just in case m changed */
566 if (i == 0 && args.next_hop == NULL) /* common case */
567 goto pass;
568 if (DUMMYNET_LOADED && (i & IP_FW_PORT_DYNT_FLAG) != 0) {
569 /* Send packet to the appropriate pipe */
570 ip_dn_io_ptr(m, i&0xffff, DN_TO_IP_IN, &args);
571 return;
572 }
573#ifdef IPDIVERT
574 if (i != 0 && (i & IP_FW_PORT_DYNT_FLAG) == 0) {
575 /* Divert or tee packet */
576 divert_info = i;
577 goto ours;
578 }
579#endif
580 if (i == 0 && args.next_hop != NULL)
581 goto pass;
582 /*
583 * if we get here, the packet must be dropped
584 */
585 m_freem(m);
586 return;
587 }
588pass:
589
590 /*
591 * Process options and, if not destined for us,
592 * ship it on. ip_dooptions returns 1 when an
593 * error was detected (causing an icmp message
594 * to be sent and the original packet to be freed).
595 */
596 ip_nhops = 0; /* for source routed packets */
597 if (hlen > sizeof (struct ip) && ip_dooptions(m, 0, args.next_hop))
598 return;
599
600 /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
601 * matter if it is destined to another node, or whether it is
602 * a multicast one, RSVP wants it! and prevents it from being forwarded
603 * anywhere else. Also checks if the rsvp daemon is running before
604 * grabbing the packet.
605 */
606 if (rsvp_on && ip->ip_p==IPPROTO_RSVP)
607 goto ours;
608
609 /*
610 * Check our list of addresses, to see if the packet is for us.
611 * If we don't have any addresses, assume any unicast packet
612 * we receive might be for us (and let the upper layers deal
613 * with it).
614 */
615 if (TAILQ_EMPTY(&in_ifaddrhead) &&
616 (m->m_flags & (M_MCAST|M_BCAST)) == 0)
617 goto ours;
618
619 /*
620 * Cache the destination address of the packet; this may be
621 * changed by use of 'ipfw fwd'.
622 */
623 pkt_dst = args.next_hop ? args.next_hop->sin_addr : ip->ip_dst;
624
625 /*
626 * Enable a consistency check between the destination address
627 * and the arrival interface for a unicast packet (the RFC 1122
628 * strong ES model) if IP forwarding is disabled and the packet
629 * is not locally generated and the packet is not subject to
630 * 'ipfw fwd'.
631 *
632 * XXX - Checking also should be disabled if the destination
633 * address is ipnat'ed to a different interface.
634 *
635 * XXX - Checking is incompatible with IP aliases added
636 * to the loopback interface instead of the interface where
637 * the packets are received.
638 */
639 checkif = ip_checkinterface && (ipforwarding == 0) &&
640 m->m_pkthdr.rcvif != NULL &&
641 ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) &&
642 (args.next_hop == NULL);
643
644 /*
645 * Check for exact addresses in the hash bucket.
646 */
647 LIST_FOREACH(ia, INADDR_HASH(pkt_dst.s_addr), ia_hash) {
648 /*
649 * If the address matches, verify that the packet
650 * arrived via the correct interface if checking is
651 * enabled.
652 */
653 if (IA_SIN(ia)->sin_addr.s_addr == pkt_dst.s_addr &&
654 (!checkif || ia->ia_ifp == m->m_pkthdr.rcvif))
655 goto ours;
656 }
657 /*
658 * Check for broadcast addresses.
659 *
660 * Only accept broadcast packets that arrive via the matching
661 * interface. Reception of forwarded directed broadcasts would
662 * be handled via ip_forward() and ether_output() with the loopback
663 * into the stack for SIMPLEX interfaces handled by ether_output().
664 */
665 if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
666 TAILQ_FOREACH(ifa, &m->m_pkthdr.rcvif->if_addrhead, ifa_link) {
667 if (ifa->ifa_addr->sa_family != AF_INET)
668 continue;
669 ia = ifatoia(ifa);
670 if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
671 pkt_dst.s_addr)
672 goto ours;
673 if (ia->ia_netbroadcast.s_addr == pkt_dst.s_addr)
674 goto ours;
675#ifdef BOOTP_COMPAT
676 if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY)
677 goto ours;
678#endif
679 }
680 }
681 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
682 struct in_multi *inm;
683 if (ip_mrouter) {
684 /*
685 * If we are acting as a multicast router, all
686 * incoming multicast packets are passed to the
687 * kernel-level multicast forwarding function.
688 * The packet is returned (relatively) intact; if
689 * ip_mforward() returns a non-zero value, the packet
690 * must be discarded, else it may be accepted below.
691 */
692 if (ip_mforward &&
693 ip_mforward(ip, m->m_pkthdr.rcvif, m, 0) != 0) {
694 ipstat.ips_cantforward++;
695 m_freem(m);
696 return;
697 }
698
699 /*
700 * The process-level routing daemon needs to receive
701 * all multicast IGMP packets, whether or not this
702 * host belongs to their destination groups.
703 */
704 if (ip->ip_p == IPPROTO_IGMP)
705 goto ours;
706 ipstat.ips_forward++;
707 }
708 /*
709 * See if we belong to the destination multicast group on the
710 * arrival interface.
711 */
712 IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
713 if (inm == NULL) {
714 ipstat.ips_notmember++;
715 m_freem(m);
716 return;
717 }
718 goto ours;
719 }
720 if (ip->ip_dst.s_addr == (u_long)INADDR_BROADCAST)
721 goto ours;
722 if (ip->ip_dst.s_addr == INADDR_ANY)
723 goto ours;
724
725 /*
726 * FAITH(Firewall Aided Internet Translator)
727 */
728 if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_type == IFT_FAITH) {
729 if (ip_keepfaith) {
730 if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_ICMP)
731 goto ours;
732 }
733 m_freem(m);
734 return;
735 }
736
737 /*
738 * Not for us; forward if possible and desirable.
739 */
740 if (ipforwarding == 0) {
741 ipstat.ips_cantforward++;
742 m_freem(m);
743 } else {
744#ifdef IPSEC
745 /*
746 * Enforce inbound IPsec SPD.
747 */
748 if (ipsec4_in_reject(m, NULL)) {
749 ipsecstat.in_polvio++;
750 goto bad;
751 }
752#endif /* IPSEC */
753#ifdef FAST_IPSEC
754 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
755 s = splnet();
756 if (mtag != NULL) {
757 tdbi = (struct tdb_ident *)(mtag + 1);
758 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
759 } else {
760 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
761 IP_FORWARDING, &error);
762 }
763 if (sp == NULL) { /* NB: can happen if error */
764 splx(s);
765 /*XXX error stat???*/
766 DPRINTF(("ip_input: no SP for forwarding\n")); /*XXX*/
767 goto bad;
768 }
769
770 /*
771 * Check security policy against packet attributes.
772 */
773 error = ipsec_in_reject(sp, m);
774 KEY_FREESP(&sp);
775 splx(s);
776 if (error) {
777 ipstat.ips_cantforward++;
778 goto bad;
779 }
780#endif /* FAST_IPSEC */
781 RTCACHE_GET(&cro);
782 ip_forward(m, &cro, srcrt, args.next_hop);
783 }
784 return;
785
786ours:
787#ifdef IPSTEALTH
788 /*
789 * IPSTEALTH: Process non-routing options only
790 * if the packet is destined for us.
791 */
792 if (ipstealth && hlen > sizeof (struct ip) &&
793 ip_dooptions(m, 1, args.next_hop))
794 return;
795#endif /* IPSTEALTH */
796
797 /* Count the packet in the ip address stats */
798 if (ia != NULL) {
799 ia->ia_ifa.if_ipackets++;
800 ia->ia_ifa.if_ibytes += m->m_pkthdr.len;
801 }
802
803 /*
804 * If offset or IP_MF are set, must reassemble.
805 * Otherwise, nothing need be done.
806 * (We could look in the reassembly queue to see
807 * if the packet was previously fragmented,
808 * but it's not worth the time; just let them time out.)
809 */
810 if (ip->ip_off & (IP_MF | IP_OFFMASK)) {
811
812 /* If maxnipq is 0, never accept fragments. */
813 if (maxnipq == 0) {
814 ipstat.ips_fragments++;
815 ipstat.ips_fragdropped++;
816 goto bad;
817 }
818
819 sum = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id);
820 IPQ_LOCK();
821 /*
822 * Look for queue of fragments
823 * of this datagram.
824 */
825 TAILQ_FOREACH(fp, &ipq[sum], ipq_list)
826 if (ip->ip_id == fp->ipq_id &&
827 ip->ip_src.s_addr == fp->ipq_src.s_addr &&
828 ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
829#ifdef MAC
830 mac_fragment_match(m, fp) &&
831#endif
832 ip->ip_p == fp->ipq_p)
833 goto found;
834
835 fp = NULL;
836
837 /*
838 * Enforce upper bound on number of fragmented packets
839 * for which we attempt reassembly;
840 * If maxnipq is -1, accept all fragments without limitation.
841 */
842 if ((nipq > maxnipq) && (maxnipq > 0)) {
843 /*
844 * drop something from the tail of the current queue
845 * before proceeding further
846 */
847 struct ipq *q = TAILQ_LAST(&ipq[sum], ipqhead);
848 if (q == NULL) { /* gak */
849 for (i = 0; i < IPREASS_NHASH; i++) {
850 struct ipq *r = TAILQ_LAST(&ipq[i], ipqhead);
851 if (r) {
852 ipstat.ips_fragtimeout += r->ipq_nfrags;
853 ip_freef(&ipq[i], r);
854 break;
855 }
856 }
857 } else {
858 ipstat.ips_fragtimeout += q->ipq_nfrags;
859 ip_freef(&ipq[sum], q);
860 }
861 }
862found:
863 /*
864 * Adjust ip_len to not reflect header,
865 * convert offset of this to bytes.
866 */
867 ip->ip_len -= hlen;
868 if (ip->ip_off & IP_MF) {
869 /*
870 * Make sure that fragments have a data length
871 * that's a non-zero multiple of 8 bytes.
872 */
873 if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
874 IPQ_UNLOCK();
875 ipstat.ips_toosmall++; /* XXX */
876 goto bad;
877 }
878 m->m_flags |= M_FRAG;
879 } else
880 m->m_flags &= ~M_FRAG;
881 ip->ip_off <<= 3;
882
883 /*
884 * Attempt reassembly; if it succeeds, proceed.
885 * ip_reass() will return a different mbuf, and update
886 * the divert info in divert_info and args.divert_rule.
887 */
888 ipstat.ips_fragments++;
889 m->m_pkthdr.header = ip;
890 m = ip_reass(m,
891 &ipq[sum], fp, &divert_info, &args.divert_rule);
892 IPQ_UNLOCK();
893 if (m == 0)
894 return;
895 ipstat.ips_reassembled++;
896 ip = mtod(m, struct ip *);
897 /* Get the header length of the reassembled packet */
898 hlen = ip->ip_hl << 2;
899#ifdef IPDIVERT
900 /* Restore original checksum before diverting packet */
901 if (divert_info != 0) {
902 ip->ip_len += hlen;
903 ip->ip_len = htons(ip->ip_len);
904 ip->ip_off = htons(ip->ip_off);
905 ip->ip_sum = 0;
906 if (hlen == sizeof(struct ip))
907 ip->ip_sum = in_cksum_hdr(ip);
908 else
909 ip->ip_sum = in_cksum(m, hlen);
910 ip->ip_off = ntohs(ip->ip_off);
911 ip->ip_len = ntohs(ip->ip_len);
912 ip->ip_len -= hlen;
913 }
914#endif
915 } else
916 ip->ip_len -= hlen;
917
918#ifdef IPDIVERT
919 /*
920 * Divert or tee packet to the divert protocol if required.
921 */
922 if (divert_info != 0) {
923 struct mbuf *clone = NULL;
924
925 /* Clone packet if we're doing a 'tee' */
926 if ((divert_info & IP_FW_PORT_TEE_FLAG) != 0)
927 clone = m_dup(m, M_DONTWAIT);
928
929 /* Restore packet header fields to original values */
930 ip->ip_len += hlen;
931 ip->ip_len = htons(ip->ip_len);
932 ip->ip_off = htons(ip->ip_off);
933
934 /* Deliver packet to divert input routine */
935 divert_packet(m, 1, divert_info & 0xffff, args.divert_rule);
936 ipstat.ips_delivered++;
937
938 /* If 'tee', continue with original packet */
939 if (clone == NULL)
940 return;
941 m = clone;
942 ip = mtod(m, struct ip *);
943 ip->ip_len += hlen;
944 /*
945 * Jump backwards to complete processing of the
946 * packet. But first clear divert_info to avoid
947 * entering this block again.
948 * We do not need to clear args.divert_rule
949 * or args.next_hop as they will not be used.
950 */
951 divert_info = 0;
952 goto pass;
953 }
954#endif
955
956#ifdef IPSEC
957 /*
958 * enforce IPsec policy checking if we are seeing last header.
959 * note that we do not visit this with protocols with pcb layer
960 * code - like udp/tcp/raw ip.
961 */
962 if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0 &&
963 ipsec4_in_reject(m, NULL)) {
964 ipsecstat.in_polvio++;
965 goto bad;
966 }
967#endif
968#if FAST_IPSEC
969 /*
970 * enforce IPsec policy checking if we are seeing last header.
971 * note that we do not visit this with protocols with pcb layer
972 * code - like udp/tcp/raw ip.
973 */
974 if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0) {
975 /*
976 * Check if the packet has already had IPsec processing
977 * done. If so, then just pass it along. This tag gets
978 * set during AH, ESP, etc. input handling, before the
979 * packet is returned to the ip input queue for delivery.
980 */
981 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
982 s = splnet();
983 if (mtag != NULL) {
984 tdbi = (struct tdb_ident *)(mtag + 1);
985 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
986 } else {
987 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
988 IP_FORWARDING, &error);
989 }
990 if (sp != NULL) {
991 /*
992 * Check security policy against packet attributes.
993 */
994 error = ipsec_in_reject(sp, m);
995 KEY_FREESP(&sp);
996 } else {
997 /* XXX error stat??? */
998 error = EINVAL;
999DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/
1000 goto bad;
1001 }
1002 splx(s);
1003 if (error)
1004 goto bad;
1005 }
1006#endif /* FAST_IPSEC */
1007
1008 /*
1009 * Switch out to protocol's input routine.
1010 */
1011 ipstat.ips_delivered++;
1012 NET_PICKUP_GIANT();
1013 if (args.next_hop && ip->ip_p == IPPROTO_TCP) {
1014 /* TCP needs IPFORWARD info if available */
1015 struct m_hdr tag;
1016
1017 tag.mh_type = MT_TAG;
1018 tag.mh_flags = PACKET_TAG_IPFORWARD;
1019 tag.mh_data = (caddr_t)args.next_hop;
1020 tag.mh_next = m;
1021
1022 (*inetsw[ip_protox[ip->ip_p]].pr_input)(
1023 (struct mbuf *)&tag, hlen);
1024 } else
1025 (*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen);
1026 NET_DROP_GIANT();
1027 return;
1028bad:
1029 m_freem(m);
1030}
1031
1032/*
1033 * Take incoming datagram fragment and try to reassemble it into
1034 * whole datagram. If a chain for reassembly of this datagram already
1035 * exists, then it is given as fp; otherwise have to make a chain.
1036 *
1037 * When IPDIVERT enabled, keep additional state with each packet that
1038 * tells us if we need to divert or tee the packet we're building.
1039 * In particular, *divinfo includes the port and TEE flag,
1040 * *divert_rule is the number of the matching rule.
1041 */
1042
1043static struct mbuf *
1044ip_reass(struct mbuf *m, struct ipqhead *head, struct ipq *fp,
1045 u_int32_t *divinfo, u_int16_t *divert_rule)
1046{
1047 struct ip *ip = mtod(m, struct ip *);
1048 register struct mbuf *p, *q, *nq;
1049 struct mbuf *t;
1050 int hlen = ip->ip_hl << 2;
1051 int i, next;
1052 u_int8_t ecn, ecn0;
1053
1054 IPQ_LOCK_ASSERT();
1055
1056 /*
1057 * Presence of header sizes in mbufs
1058 * would confuse code below.
1059 */
1060 m->m_data += hlen;
1061 m->m_len -= hlen;
1062
1063 /*
1064 * If first fragment to arrive, create a reassembly queue.
1065 */
1066 if (fp == NULL) {
1067 if ((t = m_get(M_DONTWAIT, MT_FTABLE)) == NULL)
1068 goto dropfrag;
1069 fp = mtod(t, struct ipq *);
1070#ifdef MAC
1071 if (mac_init_ipq(fp, M_NOWAIT) != 0) {
1072 m_free(t);
1073 goto dropfrag;
1074 }
1075 mac_create_ipq(m, fp);
1076#endif
1077 TAILQ_INSERT_HEAD(head, fp, ipq_list);
1078 nipq++;
1079 fp->ipq_nfrags = 1;
1080 fp->ipq_ttl = IPFRAGTTL;
1081 fp->ipq_p = ip->ip_p;
1082 fp->ipq_id = ip->ip_id;
1083 fp->ipq_src = ip->ip_src;
1084 fp->ipq_dst = ip->ip_dst;
1085 fp->ipq_frags = m;
1086 m->m_nextpkt = NULL;
1087#ifdef IPDIVERT
1088 fp->ipq_div_info = 0;
1089 fp->ipq_div_cookie = 0;
1090#endif
1091 goto inserted;
1092 } else {
1093 fp->ipq_nfrags++;
1094#ifdef MAC
1095 mac_update_ipq(m, fp);
1096#endif
1097 }
1098
1099#define GETIP(m) ((struct ip*)((m)->m_pkthdr.header))
1100
1101 /*
1102 * Handle ECN by comparing this segment with the first one;
1103 * if CE is set, do not lose CE.
1104 * drop if CE and not-ECT are mixed for the same packet.
1105 */
1106 ecn = ip->ip_tos & IPTOS_ECN_MASK;
1107 ecn0 = GETIP(fp->ipq_frags)->ip_tos & IPTOS_ECN_MASK;
1108 if (ecn == IPTOS_ECN_CE) {
1109 if (ecn0 == IPTOS_ECN_NOTECT)
1110 goto dropfrag;
1111 if (ecn0 != IPTOS_ECN_CE)
1112 GETIP(fp->ipq_frags)->ip_tos |= IPTOS_ECN_CE;
1113 }
1114 if (ecn == IPTOS_ECN_NOTECT && ecn0 != IPTOS_ECN_NOTECT)
1115 goto dropfrag;
1116
1117 /*
1118 * Find a segment which begins after this one does.
1119 */
1120 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt)
1121 if (GETIP(q)->ip_off > ip->ip_off)
1122 break;
1123
1124 /*
1125 * If there is a preceding segment, it may provide some of
1126 * our data already. If so, drop the data from the incoming
1127 * segment. If it provides all of our data, drop us, otherwise
1128 * stick new segment in the proper place.
1129 *
1130 * If some of the data is dropped from the the preceding
1131 * segment, then it's checksum is invalidated.
1132 */
1133 if (p) {
1134 i = GETIP(p)->ip_off + GETIP(p)->ip_len - ip->ip_off;
1135 if (i > 0) {
1136 if (i >= ip->ip_len)
1137 goto dropfrag;
1138 m_adj(m, i);
1139 m->m_pkthdr.csum_flags = 0;
1140 ip->ip_off += i;
1141 ip->ip_len -= i;
1142 }
1143 m->m_nextpkt = p->m_nextpkt;
1144 p->m_nextpkt = m;
1145 } else {
1146 m->m_nextpkt = fp->ipq_frags;
1147 fp->ipq_frags = m;
1148 }
1149
1150 /*
1151 * While we overlap succeeding segments trim them or,
1152 * if they are completely covered, dequeue them.
1153 */
1154 for (; q != NULL && ip->ip_off + ip->ip_len > GETIP(q)->ip_off;
1155 q = nq) {
1156 i = (ip->ip_off + ip->ip_len) - GETIP(q)->ip_off;
1157 if (i < GETIP(q)->ip_len) {
1158 GETIP(q)->ip_len -= i;
1159 GETIP(q)->ip_off += i;
1160 m_adj(q, i);
1161 q->m_pkthdr.csum_flags = 0;
1162 break;
1163 }
1164 nq = q->m_nextpkt;
1165 m->m_nextpkt = nq;
1166 ipstat.ips_fragdropped++;
1167 fp->ipq_nfrags--;
1168 m_freem(q);
1169 }
1170
1171inserted:
1172
1173#ifdef IPDIVERT
1174 /*
1175 * Transfer firewall instructions to the fragment structure.
1176 * Only trust info in the fragment at offset 0.
1177 */
1178 if (ip->ip_off == 0) {
1179 fp->ipq_div_info = *divinfo;
1180 fp->ipq_div_cookie = *divert_rule;
1181 }
1182 *divinfo = 0;
1183 *divert_rule = 0;
1184#endif
1185
1186 /*
1187 * Check for complete reassembly and perform frag per packet
1188 * limiting.
1189 *
1190 * Frag limiting is performed here so that the nth frag has
1191 * a chance to complete the packet before we drop the packet.
1192 * As a result, n+1 frags are actually allowed per packet, but
1193 * only n will ever be stored. (n = maxfragsperpacket.)
1194 *
1195 */
1196 next = 0;
1197 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) {
1198 if (GETIP(q)->ip_off != next) {
1199 if (fp->ipq_nfrags > maxfragsperpacket) {
1200 ipstat.ips_fragdropped += fp->ipq_nfrags;
1201 ip_freef(head, fp);
1202 }
1203 return (0);
1204 }
1205 next += GETIP(q)->ip_len;
1206 }
1207 /* Make sure the last packet didn't have the IP_MF flag */
1208 if (p->m_flags & M_FRAG) {
1209 if (fp->ipq_nfrags > maxfragsperpacket) {
1210 ipstat.ips_fragdropped += fp->ipq_nfrags;
1211 ip_freef(head, fp);
1212 }
1213 return (0);
1214 }
1215
1216 /*
1217 * Reassembly is complete. Make sure the packet is a sane size.
1218 */
1219 q = fp->ipq_frags;
1220 ip = GETIP(q);
1221 if (next + (ip->ip_hl << 2) > IP_MAXPACKET) {
1222 ipstat.ips_toolong++;
1223 ipstat.ips_fragdropped += fp->ipq_nfrags;
1224 ip_freef(head, fp);
1225 return (0);
1226 }
1227
1228 /*
1229 * Concatenate fragments.
1230 */
1231 m = q;
1232 t = m->m_next;
1233 m->m_next = 0;
1234 m_cat(m, t);
1235 nq = q->m_nextpkt;
1236 q->m_nextpkt = 0;
1237 for (q = nq; q != NULL; q = nq) {
1238 nq = q->m_nextpkt;
1239 q->m_nextpkt = NULL;
1240 m->m_pkthdr.csum_flags &= q->m_pkthdr.csum_flags;
1241 m->m_pkthdr.csum_data += q->m_pkthdr.csum_data;
1242 m_cat(m, q);
1243 }
1244#ifdef MAC
1245 mac_create_datagram_from_ipq(fp, m);
1246 mac_destroy_ipq(fp);
1247#endif
1248
1249#ifdef IPDIVERT
1250 /*
1251 * Extract firewall instructions from the fragment structure.
1252 */
1253 *divinfo = fp->ipq_div_info;
1254 *divert_rule = fp->ipq_div_cookie;
1255#endif
1256
1257 /*
1258 * Create header for new ip packet by
1259 * modifying header of first packet;
1260 * dequeue and discard fragment reassembly header.
1261 * Make header visible.
1262 */
1263 ip->ip_len = next;
1264 ip->ip_src = fp->ipq_src;
1265 ip->ip_dst = fp->ipq_dst;
1266 TAILQ_REMOVE(head, fp, ipq_list);
1267 nipq--;
1268 (void) m_free(dtom(fp));
1269 m->m_len += (ip->ip_hl << 2);
1270 m->m_data -= (ip->ip_hl << 2);
1271 /* some debugging cruft by sklower, below, will go away soon */
1272 if (m->m_flags & M_PKTHDR) /* XXX this should be done elsewhere */
1273 m_fixhdr(m);
1274 return (m);
1275
1276dropfrag:
1277#ifdef IPDIVERT
1278 *divinfo = 0;
1279 *divert_rule = 0;
1280#endif
1281 ipstat.ips_fragdropped++;
1282 if (fp != NULL)
1283 fp->ipq_nfrags--;
1284 m_freem(m);
1285 return (0);
1286
1287#undef GETIP
1288}
1289
1290/*
1291 * Free a fragment reassembly header and all
1292 * associated datagrams.
1293 */
1294static void
1295ip_freef(fhp, fp)
1296 struct ipqhead *fhp;
1297 struct ipq *fp;
1298{
1299 register struct mbuf *q;
1300
1301 IPQ_LOCK_ASSERT();
1302
1303 while (fp->ipq_frags) {
1304 q = fp->ipq_frags;
1305 fp->ipq_frags = q->m_nextpkt;
1306 m_freem(q);
1307 }
1308 TAILQ_REMOVE(fhp, fp, ipq_list);
1309 (void) m_free(dtom(fp));
1310 nipq--;
1311}
1312
1313/*
1314 * IP timer processing;
1315 * if a timer expires on a reassembly
1316 * queue, discard it.
1317 */
1318void
1319ip_slowtimo()
1320{
1321 register struct ipq *fp;
1322 int s = splnet();
1323 int i;
1324
1325 IPQ_LOCK();
1326 for (i = 0; i < IPREASS_NHASH; i++) {
1327 for(fp = TAILQ_FIRST(&ipq[i]); fp;) {
1328 struct ipq *fpp;
1329
1330 fpp = fp;
1331 fp = TAILQ_NEXT(fp, ipq_list);
1332 if(--fpp->ipq_ttl == 0) {
1333 ipstat.ips_fragtimeout += fpp->ipq_nfrags;
1334 ip_freef(&ipq[i], fpp);
1335 }
1336 }
1337 }
1338 /*
1339 * If we are over the maximum number of fragments
1340 * (due to the limit being lowered), drain off
1341 * enough to get down to the new limit.
1342 */
1343 if (maxnipq >= 0 && nipq > maxnipq) {
1344 for (i = 0; i < IPREASS_NHASH; i++) {
1345 while (nipq > maxnipq && !TAILQ_EMPTY(&ipq[i])) {
1346 ipstat.ips_fragdropped +=
1347 TAILQ_FIRST(&ipq[i])->ipq_nfrags;
1348 ip_freef(&ipq[i], TAILQ_FIRST(&ipq[i]));
1349 }
1350 }
1351 }
1352 IPQ_UNLOCK();
| 438 if (args.rule) { /* dummynet already filtered us */
439 ip = mtod(m, struct ip *);
440 hlen = ip->ip_hl << 2;
441 goto iphack ;
442 }
443
444 ipstat.ips_total++;
445
446 if (m->m_pkthdr.len < sizeof(struct ip))
447 goto tooshort;
448
449 if (m->m_len < sizeof (struct ip) &&
450 (m = m_pullup(m, sizeof (struct ip))) == 0) {
451 ipstat.ips_toosmall++;
452 return;
453 }
454 ip = mtod(m, struct ip *);
455
456 if (ip->ip_v != IPVERSION) {
457 ipstat.ips_badvers++;
458 goto bad;
459 }
460
461 hlen = ip->ip_hl << 2;
462 if (hlen < sizeof(struct ip)) { /* minimum header length */
463 ipstat.ips_badhlen++;
464 goto bad;
465 }
466 if (hlen > m->m_len) {
467 if ((m = m_pullup(m, hlen)) == 0) {
468 ipstat.ips_badhlen++;
469 return;
470 }
471 ip = mtod(m, struct ip *);
472 }
473
474 /* 127/8 must not appear on wire - RFC1122 */
475 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
476 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
477 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) {
478 ipstat.ips_badaddr++;
479 goto bad;
480 }
481 }
482
483 if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
484 sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID);
485 } else {
486 if (hlen == sizeof(struct ip)) {
487 sum = in_cksum_hdr(ip);
488 } else {
489 sum = in_cksum(m, hlen);
490 }
491 }
492 if (sum) {
493 ipstat.ips_badsum++;
494 goto bad;
495 }
496
497 /*
498 * Convert fields to host representation.
499 */
500 ip->ip_len = ntohs(ip->ip_len);
501 if (ip->ip_len < hlen) {
502 ipstat.ips_badlen++;
503 goto bad;
504 }
505 ip->ip_off = ntohs(ip->ip_off);
506
507 /*
508 * Check that the amount of data in the buffers
509 * is as at least much as the IP header would have us expect.
510 * Trim mbufs if longer than we expect.
511 * Drop packet if shorter than we expect.
512 */
513 if (m->m_pkthdr.len < ip->ip_len) {
514tooshort:
515 ipstat.ips_tooshort++;
516 goto bad;
517 }
518 if (m->m_pkthdr.len > ip->ip_len) {
519 if (m->m_len == m->m_pkthdr.len) {
520 m->m_len = ip->ip_len;
521 m->m_pkthdr.len = ip->ip_len;
522 } else
523 m_adj(m, ip->ip_len - m->m_pkthdr.len);
524 }
525#if defined(IPSEC) && !defined(IPSEC_FILTERGIF)
526 /*
527 * Bypass packet filtering for packets from a tunnel (gif).
528 */
529 if (ipsec_getnhist(m))
530 goto pass;
531#endif
532#if defined(FAST_IPSEC) && !defined(IPSEC_FILTERGIF)
533 /*
534 * Bypass packet filtering for packets from a tunnel (gif).
535 */
536 if (m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL)
537 goto pass;
538#endif
539
540 /*
541 * IpHack's section.
542 * Right now when no processing on packet has done
543 * and it is still fresh out of network we do our black
544 * deals with it.
545 * - Firewall: deny/allow/divert
546 * - Xlate: translate packet's addr/port (NAT).
547 * - Pipe: pass pkt through dummynet.
548 * - Wrap: fake packet's addr/port <unimpl.>
549 * - Encapsulate: put it in another IP and send out. <unimp.>
550 */
551
552iphack:
553
554#ifdef PFIL_HOOKS
555 /*
556 * Run through list of hooks for input packets.
557 *
558 * NB: Beware of the destination address changing (e.g.
559 * by NAT rewriting). When this happens, tell
560 * ip_forward to do the right thing.
561 */
562 odst = ip->ip_dst;
563 if (pfil_run_hooks(&inet_pfil_hook, &m, m->m_pkthdr.rcvif,
564 PFIL_IN) != 0)
565 return;
566 if (m == NULL) /* consumed by filter */
567 return;
568 ip = mtod(m, struct ip *);
569 srcrt = (odst.s_addr != ip->ip_dst.s_addr);
570#endif /* PFIL_HOOKS */
571
572 if (fw_enable && IPFW_LOADED) {
573 /*
574 * If we've been forwarded from the output side, then
575 * skip the firewall a second time
576 */
577 if (args.next_hop)
578 goto ours;
579
580 args.m = m;
581 i = ip_fw_chk_ptr(&args);
582 m = args.m;
583
584 if ( (i & IP_FW_PORT_DENY_FLAG) || m == NULL) { /* drop */
585 if (m)
586 m_freem(m);
587 return;
588 }
589 ip = mtod(m, struct ip *); /* just in case m changed */
590 if (i == 0 && args.next_hop == NULL) /* common case */
591 goto pass;
592 if (DUMMYNET_LOADED && (i & IP_FW_PORT_DYNT_FLAG) != 0) {
593 /* Send packet to the appropriate pipe */
594 ip_dn_io_ptr(m, i&0xffff, DN_TO_IP_IN, &args);
595 return;
596 }
597#ifdef IPDIVERT
598 if (i != 0 && (i & IP_FW_PORT_DYNT_FLAG) == 0) {
599 /* Divert or tee packet */
600 divert_info = i;
601 goto ours;
602 }
603#endif
604 if (i == 0 && args.next_hop != NULL)
605 goto pass;
606 /*
607 * if we get here, the packet must be dropped
608 */
609 m_freem(m);
610 return;
611 }
612pass:
613
614 /*
615 * Process options and, if not destined for us,
616 * ship it on. ip_dooptions returns 1 when an
617 * error was detected (causing an icmp message
618 * to be sent and the original packet to be freed).
619 */
620 ip_nhops = 0; /* for source routed packets */
621 if (hlen > sizeof (struct ip) && ip_dooptions(m, 0, args.next_hop))
622 return;
623
624 /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
625 * matter if it is destined to another node, or whether it is
626 * a multicast one, RSVP wants it! and prevents it from being forwarded
627 * anywhere else. Also checks if the rsvp daemon is running before
628 * grabbing the packet.
629 */
630 if (rsvp_on && ip->ip_p==IPPROTO_RSVP)
631 goto ours;
632
633 /*
634 * Check our list of addresses, to see if the packet is for us.
635 * If we don't have any addresses, assume any unicast packet
636 * we receive might be for us (and let the upper layers deal
637 * with it).
638 */
639 if (TAILQ_EMPTY(&in_ifaddrhead) &&
640 (m->m_flags & (M_MCAST|M_BCAST)) == 0)
641 goto ours;
642
643 /*
644 * Cache the destination address of the packet; this may be
645 * changed by use of 'ipfw fwd'.
646 */
647 pkt_dst = args.next_hop ? args.next_hop->sin_addr : ip->ip_dst;
648
649 /*
650 * Enable a consistency check between the destination address
651 * and the arrival interface for a unicast packet (the RFC 1122
652 * strong ES model) if IP forwarding is disabled and the packet
653 * is not locally generated and the packet is not subject to
654 * 'ipfw fwd'.
655 *
656 * XXX - Checking also should be disabled if the destination
657 * address is ipnat'ed to a different interface.
658 *
659 * XXX - Checking is incompatible with IP aliases added
660 * to the loopback interface instead of the interface where
661 * the packets are received.
662 */
663 checkif = ip_checkinterface && (ipforwarding == 0) &&
664 m->m_pkthdr.rcvif != NULL &&
665 ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) &&
666 (args.next_hop == NULL);
667
668 /*
669 * Check for exact addresses in the hash bucket.
670 */
671 LIST_FOREACH(ia, INADDR_HASH(pkt_dst.s_addr), ia_hash) {
672 /*
673 * If the address matches, verify that the packet
674 * arrived via the correct interface if checking is
675 * enabled.
676 */
677 if (IA_SIN(ia)->sin_addr.s_addr == pkt_dst.s_addr &&
678 (!checkif || ia->ia_ifp == m->m_pkthdr.rcvif))
679 goto ours;
680 }
681 /*
682 * Check for broadcast addresses.
683 *
684 * Only accept broadcast packets that arrive via the matching
685 * interface. Reception of forwarded directed broadcasts would
686 * be handled via ip_forward() and ether_output() with the loopback
687 * into the stack for SIMPLEX interfaces handled by ether_output().
688 */
689 if (m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
690 TAILQ_FOREACH(ifa, &m->m_pkthdr.rcvif->if_addrhead, ifa_link) {
691 if (ifa->ifa_addr->sa_family != AF_INET)
692 continue;
693 ia = ifatoia(ifa);
694 if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
695 pkt_dst.s_addr)
696 goto ours;
697 if (ia->ia_netbroadcast.s_addr == pkt_dst.s_addr)
698 goto ours;
699#ifdef BOOTP_COMPAT
700 if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY)
701 goto ours;
702#endif
703 }
704 }
705 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
706 struct in_multi *inm;
707 if (ip_mrouter) {
708 /*
709 * If we are acting as a multicast router, all
710 * incoming multicast packets are passed to the
711 * kernel-level multicast forwarding function.
712 * The packet is returned (relatively) intact; if
713 * ip_mforward() returns a non-zero value, the packet
714 * must be discarded, else it may be accepted below.
715 */
716 if (ip_mforward &&
717 ip_mforward(ip, m->m_pkthdr.rcvif, m, 0) != 0) {
718 ipstat.ips_cantforward++;
719 m_freem(m);
720 return;
721 }
722
723 /*
724 * The process-level routing daemon needs to receive
725 * all multicast IGMP packets, whether or not this
726 * host belongs to their destination groups.
727 */
728 if (ip->ip_p == IPPROTO_IGMP)
729 goto ours;
730 ipstat.ips_forward++;
731 }
732 /*
733 * See if we belong to the destination multicast group on the
734 * arrival interface.
735 */
736 IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
737 if (inm == NULL) {
738 ipstat.ips_notmember++;
739 m_freem(m);
740 return;
741 }
742 goto ours;
743 }
744 if (ip->ip_dst.s_addr == (u_long)INADDR_BROADCAST)
745 goto ours;
746 if (ip->ip_dst.s_addr == INADDR_ANY)
747 goto ours;
748
749 /*
750 * FAITH(Firewall Aided Internet Translator)
751 */
752 if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_type == IFT_FAITH) {
753 if (ip_keepfaith) {
754 if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_ICMP)
755 goto ours;
756 }
757 m_freem(m);
758 return;
759 }
760
761 /*
762 * Not for us; forward if possible and desirable.
763 */
764 if (ipforwarding == 0) {
765 ipstat.ips_cantforward++;
766 m_freem(m);
767 } else {
768#ifdef IPSEC
769 /*
770 * Enforce inbound IPsec SPD.
771 */
772 if (ipsec4_in_reject(m, NULL)) {
773 ipsecstat.in_polvio++;
774 goto bad;
775 }
776#endif /* IPSEC */
777#ifdef FAST_IPSEC
778 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
779 s = splnet();
780 if (mtag != NULL) {
781 tdbi = (struct tdb_ident *)(mtag + 1);
782 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
783 } else {
784 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
785 IP_FORWARDING, &error);
786 }
787 if (sp == NULL) { /* NB: can happen if error */
788 splx(s);
789 /*XXX error stat???*/
790 DPRINTF(("ip_input: no SP for forwarding\n")); /*XXX*/
791 goto bad;
792 }
793
794 /*
795 * Check security policy against packet attributes.
796 */
797 error = ipsec_in_reject(sp, m);
798 KEY_FREESP(&sp);
799 splx(s);
800 if (error) {
801 ipstat.ips_cantforward++;
802 goto bad;
803 }
804#endif /* FAST_IPSEC */
805 RTCACHE_GET(&cro);
806 ip_forward(m, &cro, srcrt, args.next_hop);
807 }
808 return;
809
810ours:
811#ifdef IPSTEALTH
812 /*
813 * IPSTEALTH: Process non-routing options only
814 * if the packet is destined for us.
815 */
816 if (ipstealth && hlen > sizeof (struct ip) &&
817 ip_dooptions(m, 1, args.next_hop))
818 return;
819#endif /* IPSTEALTH */
820
821 /* Count the packet in the ip address stats */
822 if (ia != NULL) {
823 ia->ia_ifa.if_ipackets++;
824 ia->ia_ifa.if_ibytes += m->m_pkthdr.len;
825 }
826
827 /*
828 * If offset or IP_MF are set, must reassemble.
829 * Otherwise, nothing need be done.
830 * (We could look in the reassembly queue to see
831 * if the packet was previously fragmented,
832 * but it's not worth the time; just let them time out.)
833 */
834 if (ip->ip_off & (IP_MF | IP_OFFMASK)) {
835
836 /* If maxnipq is 0, never accept fragments. */
837 if (maxnipq == 0) {
838 ipstat.ips_fragments++;
839 ipstat.ips_fragdropped++;
840 goto bad;
841 }
842
843 sum = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id);
844 IPQ_LOCK();
845 /*
846 * Look for queue of fragments
847 * of this datagram.
848 */
849 TAILQ_FOREACH(fp, &ipq[sum], ipq_list)
850 if (ip->ip_id == fp->ipq_id &&
851 ip->ip_src.s_addr == fp->ipq_src.s_addr &&
852 ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
853#ifdef MAC
854 mac_fragment_match(m, fp) &&
855#endif
856 ip->ip_p == fp->ipq_p)
857 goto found;
858
859 fp = NULL;
860
861 /*
862 * Enforce upper bound on number of fragmented packets
863 * for which we attempt reassembly;
864 * If maxnipq is -1, accept all fragments without limitation.
865 */
866 if ((nipq > maxnipq) && (maxnipq > 0)) {
867 /*
868 * drop something from the tail of the current queue
869 * before proceeding further
870 */
871 struct ipq *q = TAILQ_LAST(&ipq[sum], ipqhead);
872 if (q == NULL) { /* gak */
873 for (i = 0; i < IPREASS_NHASH; i++) {
874 struct ipq *r = TAILQ_LAST(&ipq[i], ipqhead);
875 if (r) {
876 ipstat.ips_fragtimeout += r->ipq_nfrags;
877 ip_freef(&ipq[i], r);
878 break;
879 }
880 }
881 } else {
882 ipstat.ips_fragtimeout += q->ipq_nfrags;
883 ip_freef(&ipq[sum], q);
884 }
885 }
886found:
887 /*
888 * Adjust ip_len to not reflect header,
889 * convert offset of this to bytes.
890 */
891 ip->ip_len -= hlen;
892 if (ip->ip_off & IP_MF) {
893 /*
894 * Make sure that fragments have a data length
895 * that's a non-zero multiple of 8 bytes.
896 */
897 if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
898 IPQ_UNLOCK();
899 ipstat.ips_toosmall++; /* XXX */
900 goto bad;
901 }
902 m->m_flags |= M_FRAG;
903 } else
904 m->m_flags &= ~M_FRAG;
905 ip->ip_off <<= 3;
906
907 /*
908 * Attempt reassembly; if it succeeds, proceed.
909 * ip_reass() will return a different mbuf, and update
910 * the divert info in divert_info and args.divert_rule.
911 */
912 ipstat.ips_fragments++;
913 m->m_pkthdr.header = ip;
914 m = ip_reass(m,
915 &ipq[sum], fp, &divert_info, &args.divert_rule);
916 IPQ_UNLOCK();
917 if (m == 0)
918 return;
919 ipstat.ips_reassembled++;
920 ip = mtod(m, struct ip *);
921 /* Get the header length of the reassembled packet */
922 hlen = ip->ip_hl << 2;
923#ifdef IPDIVERT
924 /* Restore original checksum before diverting packet */
925 if (divert_info != 0) {
926 ip->ip_len += hlen;
927 ip->ip_len = htons(ip->ip_len);
928 ip->ip_off = htons(ip->ip_off);
929 ip->ip_sum = 0;
930 if (hlen == sizeof(struct ip))
931 ip->ip_sum = in_cksum_hdr(ip);
932 else
933 ip->ip_sum = in_cksum(m, hlen);
934 ip->ip_off = ntohs(ip->ip_off);
935 ip->ip_len = ntohs(ip->ip_len);
936 ip->ip_len -= hlen;
937 }
938#endif
939 } else
940 ip->ip_len -= hlen;
941
942#ifdef IPDIVERT
943 /*
944 * Divert or tee packet to the divert protocol if required.
945 */
946 if (divert_info != 0) {
947 struct mbuf *clone = NULL;
948
949 /* Clone packet if we're doing a 'tee' */
950 if ((divert_info & IP_FW_PORT_TEE_FLAG) != 0)
951 clone = m_dup(m, M_DONTWAIT);
952
953 /* Restore packet header fields to original values */
954 ip->ip_len += hlen;
955 ip->ip_len = htons(ip->ip_len);
956 ip->ip_off = htons(ip->ip_off);
957
958 /* Deliver packet to divert input routine */
959 divert_packet(m, 1, divert_info & 0xffff, args.divert_rule);
960 ipstat.ips_delivered++;
961
962 /* If 'tee', continue with original packet */
963 if (clone == NULL)
964 return;
965 m = clone;
966 ip = mtod(m, struct ip *);
967 ip->ip_len += hlen;
968 /*
969 * Jump backwards to complete processing of the
970 * packet. But first clear divert_info to avoid
971 * entering this block again.
972 * We do not need to clear args.divert_rule
973 * or args.next_hop as they will not be used.
974 */
975 divert_info = 0;
976 goto pass;
977 }
978#endif
979
980#ifdef IPSEC
981 /*
982 * enforce IPsec policy checking if we are seeing last header.
983 * note that we do not visit this with protocols with pcb layer
984 * code - like udp/tcp/raw ip.
985 */
986 if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0 &&
987 ipsec4_in_reject(m, NULL)) {
988 ipsecstat.in_polvio++;
989 goto bad;
990 }
991#endif
992#if FAST_IPSEC
993 /*
994 * enforce IPsec policy checking if we are seeing last header.
995 * note that we do not visit this with protocols with pcb layer
996 * code - like udp/tcp/raw ip.
997 */
998 if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0) {
999 /*
1000 * Check if the packet has already had IPsec processing
1001 * done. If so, then just pass it along. This tag gets
1002 * set during AH, ESP, etc. input handling, before the
1003 * packet is returned to the ip input queue for delivery.
1004 */
1005 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
1006 s = splnet();
1007 if (mtag != NULL) {
1008 tdbi = (struct tdb_ident *)(mtag + 1);
1009 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
1010 } else {
1011 sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
1012 IP_FORWARDING, &error);
1013 }
1014 if (sp != NULL) {
1015 /*
1016 * Check security policy against packet attributes.
1017 */
1018 error = ipsec_in_reject(sp, m);
1019 KEY_FREESP(&sp);
1020 } else {
1021 /* XXX error stat??? */
1022 error = EINVAL;
1023DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/
1024 goto bad;
1025 }
1026 splx(s);
1027 if (error)
1028 goto bad;
1029 }
1030#endif /* FAST_IPSEC */
1031
1032 /*
1033 * Switch out to protocol's input routine.
1034 */
1035 ipstat.ips_delivered++;
1036 NET_PICKUP_GIANT();
1037 if (args.next_hop && ip->ip_p == IPPROTO_TCP) {
1038 /* TCP needs IPFORWARD info if available */
1039 struct m_hdr tag;
1040
1041 tag.mh_type = MT_TAG;
1042 tag.mh_flags = PACKET_TAG_IPFORWARD;
1043 tag.mh_data = (caddr_t)args.next_hop;
1044 tag.mh_next = m;
1045
1046 (*inetsw[ip_protox[ip->ip_p]].pr_input)(
1047 (struct mbuf *)&tag, hlen);
1048 } else
1049 (*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen);
1050 NET_DROP_GIANT();
1051 return;
1052bad:
1053 m_freem(m);
1054}
1055
1056/*
1057 * Take incoming datagram fragment and try to reassemble it into
1058 * whole datagram. If a chain for reassembly of this datagram already
1059 * exists, then it is given as fp; otherwise have to make a chain.
1060 *
1061 * When IPDIVERT enabled, keep additional state with each packet that
1062 * tells us if we need to divert or tee the packet we're building.
1063 * In particular, *divinfo includes the port and TEE flag,
1064 * *divert_rule is the number of the matching rule.
1065 */
1066
1067static struct mbuf *
1068ip_reass(struct mbuf *m, struct ipqhead *head, struct ipq *fp,
1069 u_int32_t *divinfo, u_int16_t *divert_rule)
1070{
1071 struct ip *ip = mtod(m, struct ip *);
1072 register struct mbuf *p, *q, *nq;
1073 struct mbuf *t;
1074 int hlen = ip->ip_hl << 2;
1075 int i, next;
1076 u_int8_t ecn, ecn0;
1077
1078 IPQ_LOCK_ASSERT();
1079
1080 /*
1081 * Presence of header sizes in mbufs
1082 * would confuse code below.
1083 */
1084 m->m_data += hlen;
1085 m->m_len -= hlen;
1086
1087 /*
1088 * If first fragment to arrive, create a reassembly queue.
1089 */
1090 if (fp == NULL) {
1091 if ((t = m_get(M_DONTWAIT, MT_FTABLE)) == NULL)
1092 goto dropfrag;
1093 fp = mtod(t, struct ipq *);
1094#ifdef MAC
1095 if (mac_init_ipq(fp, M_NOWAIT) != 0) {
1096 m_free(t);
1097 goto dropfrag;
1098 }
1099 mac_create_ipq(m, fp);
1100#endif
1101 TAILQ_INSERT_HEAD(head, fp, ipq_list);
1102 nipq++;
1103 fp->ipq_nfrags = 1;
1104 fp->ipq_ttl = IPFRAGTTL;
1105 fp->ipq_p = ip->ip_p;
1106 fp->ipq_id = ip->ip_id;
1107 fp->ipq_src = ip->ip_src;
1108 fp->ipq_dst = ip->ip_dst;
1109 fp->ipq_frags = m;
1110 m->m_nextpkt = NULL;
1111#ifdef IPDIVERT
1112 fp->ipq_div_info = 0;
1113 fp->ipq_div_cookie = 0;
1114#endif
1115 goto inserted;
1116 } else {
1117 fp->ipq_nfrags++;
1118#ifdef MAC
1119 mac_update_ipq(m, fp);
1120#endif
1121 }
1122
1123#define GETIP(m) ((struct ip*)((m)->m_pkthdr.header))
1124
1125 /*
1126 * Handle ECN by comparing this segment with the first one;
1127 * if CE is set, do not lose CE.
1128 * drop if CE and not-ECT are mixed for the same packet.
1129 */
1130 ecn = ip->ip_tos & IPTOS_ECN_MASK;
1131 ecn0 = GETIP(fp->ipq_frags)->ip_tos & IPTOS_ECN_MASK;
1132 if (ecn == IPTOS_ECN_CE) {
1133 if (ecn0 == IPTOS_ECN_NOTECT)
1134 goto dropfrag;
1135 if (ecn0 != IPTOS_ECN_CE)
1136 GETIP(fp->ipq_frags)->ip_tos |= IPTOS_ECN_CE;
1137 }
1138 if (ecn == IPTOS_ECN_NOTECT && ecn0 != IPTOS_ECN_NOTECT)
1139 goto dropfrag;
1140
1141 /*
1142 * Find a segment which begins after this one does.
1143 */
1144 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt)
1145 if (GETIP(q)->ip_off > ip->ip_off)
1146 break;
1147
1148 /*
1149 * If there is a preceding segment, it may provide some of
1150 * our data already. If so, drop the data from the incoming
1151 * segment. If it provides all of our data, drop us, otherwise
1152 * stick new segment in the proper place.
1153 *
1154 * If some of the data is dropped from the the preceding
1155 * segment, then it's checksum is invalidated.
1156 */
1157 if (p) {
1158 i = GETIP(p)->ip_off + GETIP(p)->ip_len - ip->ip_off;
1159 if (i > 0) {
1160 if (i >= ip->ip_len)
1161 goto dropfrag;
1162 m_adj(m, i);
1163 m->m_pkthdr.csum_flags = 0;
1164 ip->ip_off += i;
1165 ip->ip_len -= i;
1166 }
1167 m->m_nextpkt = p->m_nextpkt;
1168 p->m_nextpkt = m;
1169 } else {
1170 m->m_nextpkt = fp->ipq_frags;
1171 fp->ipq_frags = m;
1172 }
1173
1174 /*
1175 * While we overlap succeeding segments trim them or,
1176 * if they are completely covered, dequeue them.
1177 */
1178 for (; q != NULL && ip->ip_off + ip->ip_len > GETIP(q)->ip_off;
1179 q = nq) {
1180 i = (ip->ip_off + ip->ip_len) - GETIP(q)->ip_off;
1181 if (i < GETIP(q)->ip_len) {
1182 GETIP(q)->ip_len -= i;
1183 GETIP(q)->ip_off += i;
1184 m_adj(q, i);
1185 q->m_pkthdr.csum_flags = 0;
1186 break;
1187 }
1188 nq = q->m_nextpkt;
1189 m->m_nextpkt = nq;
1190 ipstat.ips_fragdropped++;
1191 fp->ipq_nfrags--;
1192 m_freem(q);
1193 }
1194
1195inserted:
1196
1197#ifdef IPDIVERT
1198 /*
1199 * Transfer firewall instructions to the fragment structure.
1200 * Only trust info in the fragment at offset 0.
1201 */
1202 if (ip->ip_off == 0) {
1203 fp->ipq_div_info = *divinfo;
1204 fp->ipq_div_cookie = *divert_rule;
1205 }
1206 *divinfo = 0;
1207 *divert_rule = 0;
1208#endif
1209
1210 /*
1211 * Check for complete reassembly and perform frag per packet
1212 * limiting.
1213 *
1214 * Frag limiting is performed here so that the nth frag has
1215 * a chance to complete the packet before we drop the packet.
1216 * As a result, n+1 frags are actually allowed per packet, but
1217 * only n will ever be stored. (n = maxfragsperpacket.)
1218 *
1219 */
1220 next = 0;
1221 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) {
1222 if (GETIP(q)->ip_off != next) {
1223 if (fp->ipq_nfrags > maxfragsperpacket) {
1224 ipstat.ips_fragdropped += fp->ipq_nfrags;
1225 ip_freef(head, fp);
1226 }
1227 return (0);
1228 }
1229 next += GETIP(q)->ip_len;
1230 }
1231 /* Make sure the last packet didn't have the IP_MF flag */
1232 if (p->m_flags & M_FRAG) {
1233 if (fp->ipq_nfrags > maxfragsperpacket) {
1234 ipstat.ips_fragdropped += fp->ipq_nfrags;
1235 ip_freef(head, fp);
1236 }
1237 return (0);
1238 }
1239
1240 /*
1241 * Reassembly is complete. Make sure the packet is a sane size.
1242 */
1243 q = fp->ipq_frags;
1244 ip = GETIP(q);
1245 if (next + (ip->ip_hl << 2) > IP_MAXPACKET) {
1246 ipstat.ips_toolong++;
1247 ipstat.ips_fragdropped += fp->ipq_nfrags;
1248 ip_freef(head, fp);
1249 return (0);
1250 }
1251
1252 /*
1253 * Concatenate fragments.
1254 */
1255 m = q;
1256 t = m->m_next;
1257 m->m_next = 0;
1258 m_cat(m, t);
1259 nq = q->m_nextpkt;
1260 q->m_nextpkt = 0;
1261 for (q = nq; q != NULL; q = nq) {
1262 nq = q->m_nextpkt;
1263 q->m_nextpkt = NULL;
1264 m->m_pkthdr.csum_flags &= q->m_pkthdr.csum_flags;
1265 m->m_pkthdr.csum_data += q->m_pkthdr.csum_data;
1266 m_cat(m, q);
1267 }
1268#ifdef MAC
1269 mac_create_datagram_from_ipq(fp, m);
1270 mac_destroy_ipq(fp);
1271#endif
1272
1273#ifdef IPDIVERT
1274 /*
1275 * Extract firewall instructions from the fragment structure.
1276 */
1277 *divinfo = fp->ipq_div_info;
1278 *divert_rule = fp->ipq_div_cookie;
1279#endif
1280
1281 /*
1282 * Create header for new ip packet by
1283 * modifying header of first packet;
1284 * dequeue and discard fragment reassembly header.
1285 * Make header visible.
1286 */
1287 ip->ip_len = next;
1288 ip->ip_src = fp->ipq_src;
1289 ip->ip_dst = fp->ipq_dst;
1290 TAILQ_REMOVE(head, fp, ipq_list);
1291 nipq--;
1292 (void) m_free(dtom(fp));
1293 m->m_len += (ip->ip_hl << 2);
1294 m->m_data -= (ip->ip_hl << 2);
1295 /* some debugging cruft by sklower, below, will go away soon */
1296 if (m->m_flags & M_PKTHDR) /* XXX this should be done elsewhere */
1297 m_fixhdr(m);
1298 return (m);
1299
1300dropfrag:
1301#ifdef IPDIVERT
1302 *divinfo = 0;
1303 *divert_rule = 0;
1304#endif
1305 ipstat.ips_fragdropped++;
1306 if (fp != NULL)
1307 fp->ipq_nfrags--;
1308 m_freem(m);
1309 return (0);
1310
1311#undef GETIP
1312}
1313
1314/*
1315 * Free a fragment reassembly header and all
1316 * associated datagrams.
1317 */
1318static void
1319ip_freef(fhp, fp)
1320 struct ipqhead *fhp;
1321 struct ipq *fp;
1322{
1323 register struct mbuf *q;
1324
1325 IPQ_LOCK_ASSERT();
1326
1327 while (fp->ipq_frags) {
1328 q = fp->ipq_frags;
1329 fp->ipq_frags = q->m_nextpkt;
1330 m_freem(q);
1331 }
1332 TAILQ_REMOVE(fhp, fp, ipq_list);
1333 (void) m_free(dtom(fp));
1334 nipq--;
1335}
1336
1337/*
1338 * IP timer processing;
1339 * if a timer expires on a reassembly
1340 * queue, discard it.
1341 */
1342void
1343ip_slowtimo()
1344{
1345 register struct ipq *fp;
1346 int s = splnet();
1347 int i;
1348
1349 IPQ_LOCK();
1350 for (i = 0; i < IPREASS_NHASH; i++) {
1351 for(fp = TAILQ_FIRST(&ipq[i]); fp;) {
1352 struct ipq *fpp;
1353
1354 fpp = fp;
1355 fp = TAILQ_NEXT(fp, ipq_list);
1356 if(--fpp->ipq_ttl == 0) {
1357 ipstat.ips_fragtimeout += fpp->ipq_nfrags;
1358 ip_freef(&ipq[i], fpp);
1359 }
1360 }
1361 }
1362 /*
1363 * If we are over the maximum number of fragments
1364 * (due to the limit being lowered), drain off
1365 * enough to get down to the new limit.
1366 */
1367 if (maxnipq >= 0 && nipq > maxnipq) {
1368 for (i = 0; i < IPREASS_NHASH; i++) {
1369 while (nipq > maxnipq && !TAILQ_EMPTY(&ipq[i])) {
1370 ipstat.ips_fragdropped +=
1371 TAILQ_FIRST(&ipq[i])->ipq_nfrags;
1372 ip_freef(&ipq[i], TAILQ_FIRST(&ipq[i]));
1373 }
1374 }
1375 }
1376 IPQ_UNLOCK();
|
1353 ipflow_slowtimo();
| |
1354 splx(s);
1355}
1356
1357/*
1358 * Drain off all datagram fragments.
1359 */
1360void
1361ip_drain()
1362{
1363 int i;
1364
1365 IPQ_LOCK();
1366 for (i = 0; i < IPREASS_NHASH; i++) {
1367 while(!TAILQ_EMPTY(&ipq[i])) {
1368 ipstat.ips_fragdropped +=
1369 TAILQ_FIRST(&ipq[i])->ipq_nfrags;
1370 ip_freef(&ipq[i], TAILQ_FIRST(&ipq[i]));
1371 }
1372 }
1373 IPQ_UNLOCK();
1374 in_rtqdrain();
1375}
1376
1377/*
1378 * Do option processing on a datagram,
1379 * possibly discarding it if bad options are encountered,
1380 * or forwarding it if source-routed.
1381 * The pass argument is used when operating in the IPSTEALTH
1382 * mode to tell what options to process:
1383 * [LS]SRR (pass 0) or the others (pass 1).
1384 * The reason for as many as two passes is that when doing IPSTEALTH,
1385 * non-routing options should be processed only if the packet is for us.
1386 * Returns 1 if packet has been forwarded/freed,
1387 * 0 if the packet should be processed further.
1388 */
1389static int
1390ip_dooptions(struct mbuf *m, int pass, struct sockaddr_in *next_hop)
1391{
1392 struct ip *ip = mtod(m, struct ip *);
1393 u_char *cp;
1394 struct in_ifaddr *ia;
1395 int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
1396 struct in_addr *sin, dst;
1397 n_time ntime;
1398 struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET };
1399 struct route cro; /* copy of cached route */
1400
1401 /*
1402 * Grab a copy of the route cache in case we need
1403 * to update to reflect source routing or the like.
1404 * Could optimize this to do it later...
1405 */
1406 RTCACHE_GET(&cro);
1407
1408 dst = ip->ip_dst;
1409 cp = (u_char *)(ip + 1);
1410 cnt = (ip->ip_hl << 2) - sizeof (struct ip);
1411 for (; cnt > 0; cnt -= optlen, cp += optlen) {
1412 opt = cp[IPOPT_OPTVAL];
1413 if (opt == IPOPT_EOL)
1414 break;
1415 if (opt == IPOPT_NOP)
1416 optlen = 1;
1417 else {
1418 if (cnt < IPOPT_OLEN + sizeof(*cp)) {
1419 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1420 goto bad;
1421 }
1422 optlen = cp[IPOPT_OLEN];
1423 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) {
1424 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1425 goto bad;
1426 }
1427 }
1428 switch (opt) {
1429
1430 default:
1431 break;
1432
1433 /*
1434 * Source routing with record.
1435 * Find interface with current destination address.
1436 * If none on this machine then drop if strictly routed,
1437 * or do nothing if loosely routed.
1438 * Record interface address and bring up next address
1439 * component. If strictly routed make sure next
1440 * address is on directly accessible net.
1441 */
1442 case IPOPT_LSRR:
1443 case IPOPT_SSRR:
1444#ifdef IPSTEALTH
1445 if (ipstealth && pass > 0)
1446 break;
1447#endif
1448 if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1449 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1450 goto bad;
1451 }
1452 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1453 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1454 goto bad;
1455 }
1456 ipaddr.sin_addr = ip->ip_dst;
1457 ia = (struct in_ifaddr *)
1458 ifa_ifwithaddr((struct sockaddr *)&ipaddr);
1459 if (ia == 0) {
1460 if (opt == IPOPT_SSRR) {
1461 type = ICMP_UNREACH;
1462 code = ICMP_UNREACH_SRCFAIL;
1463 goto bad;
1464 }
1465 if (!ip_dosourceroute)
1466 goto nosourcerouting;
1467 /*
1468 * Loose routing, and not at next destination
1469 * yet; nothing to do except forward.
1470 */
1471 break;
1472 }
1473 off--; /* 0 origin */
1474 if (off > optlen - (int)sizeof(struct in_addr)) {
1475 /*
1476 * End of source route. Should be for us.
1477 */
1478 if (!ip_acceptsourceroute)
1479 goto nosourcerouting;
1480 save_rte(cp, ip->ip_src);
1481 break;
1482 }
1483#ifdef IPSTEALTH
1484 if (ipstealth)
1485 goto dropit;
1486#endif
1487 if (!ip_dosourceroute) {
1488 if (ipforwarding) {
1489 char buf[16]; /* aaa.bbb.ccc.ddd\0 */
1490 /*
1491 * Acting as a router, so generate ICMP
1492 */
1493nosourcerouting:
1494 strcpy(buf, inet_ntoa(ip->ip_dst));
1495 log(LOG_WARNING,
1496 "attempted source route from %s to %s\n",
1497 inet_ntoa(ip->ip_src), buf);
1498 type = ICMP_UNREACH;
1499 code = ICMP_UNREACH_SRCFAIL;
1500 goto bad;
1501 } else {
1502 /*
1503 * Not acting as a router, so silently drop.
1504 */
1505#ifdef IPSTEALTH
1506dropit:
1507#endif
1508 ipstat.ips_cantforward++;
1509 m_freem(m);
1510 return (1);
1511 }
1512 }
1513
1514 /*
1515 * locate outgoing interface
1516 */
1517 (void)memcpy(&ipaddr.sin_addr, cp + off,
1518 sizeof(ipaddr.sin_addr));
1519
1520 if (opt == IPOPT_SSRR) {
1521#define INA struct in_ifaddr *
1522#define SA struct sockaddr *
1523 if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr)) == 0)
1524 ia = (INA)ifa_ifwithnet((SA)&ipaddr);
1525 } else
1526 ia = ip_rtaddr(ipaddr.sin_addr, &cro);
1527 if (ia == 0) {
1528 type = ICMP_UNREACH;
1529 code = ICMP_UNREACH_SRCFAIL;
1530 goto bad;
1531 }
1532 ip->ip_dst = ipaddr.sin_addr;
1533 (void)memcpy(cp + off, &(IA_SIN(ia)->sin_addr),
1534 sizeof(struct in_addr));
1535 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1536 /*
1537 * Let ip_intr's mcast routing check handle mcast pkts
1538 */
1539 forward = !IN_MULTICAST(ntohl(ip->ip_dst.s_addr));
1540 break;
1541
1542 case IPOPT_RR:
1543#ifdef IPSTEALTH
1544 if (ipstealth && pass == 0)
1545 break;
1546#endif
1547 if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1548 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1549 goto bad;
1550 }
1551 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1552 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1553 goto bad;
1554 }
1555 /*
1556 * If no space remains, ignore.
1557 */
1558 off--; /* 0 origin */
1559 if (off > optlen - (int)sizeof(struct in_addr))
1560 break;
1561 (void)memcpy(&ipaddr.sin_addr, &ip->ip_dst,
1562 sizeof(ipaddr.sin_addr));
1563 /*
1564 * locate outgoing interface; if we're the destination,
1565 * use the incoming interface (should be same).
1566 */
1567 if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 &&
1568 (ia = ip_rtaddr(ipaddr.sin_addr, &cro)) == 0) {
1569 type = ICMP_UNREACH;
1570 code = ICMP_UNREACH_HOST;
1571 goto bad;
1572 }
1573 (void)memcpy(cp + off, &(IA_SIN(ia)->sin_addr),
1574 sizeof(struct in_addr));
1575 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1576 break;
1577
1578 case IPOPT_TS:
1579#ifdef IPSTEALTH
1580 if (ipstealth && pass == 0)
1581 break;
1582#endif
1583 code = cp - (u_char *)ip;
1584 if (optlen < 4 || optlen > 40) {
1585 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1586 goto bad;
1587 }
1588 if ((off = cp[IPOPT_OFFSET]) < 5) {
1589 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1590 goto bad;
1591 }
1592 if (off > optlen - (int)sizeof(int32_t)) {
1593 cp[IPOPT_OFFSET + 1] += (1 << 4);
1594 if ((cp[IPOPT_OFFSET + 1] & 0xf0) == 0) {
1595 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1596 goto bad;
1597 }
1598 break;
1599 }
1600 off--; /* 0 origin */
1601 sin = (struct in_addr *)(cp + off);
1602 switch (cp[IPOPT_OFFSET + 1] & 0x0f) {
1603
1604 case IPOPT_TS_TSONLY:
1605 break;
1606
1607 case IPOPT_TS_TSANDADDR:
1608 if (off + sizeof(n_time) +
1609 sizeof(struct in_addr) > optlen) {
1610 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1611 goto bad;
1612 }
1613 ipaddr.sin_addr = dst;
1614 ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
1615 m->m_pkthdr.rcvif);
1616 if (ia == 0)
1617 continue;
1618 (void)memcpy(sin, &IA_SIN(ia)->sin_addr,
1619 sizeof(struct in_addr));
1620 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1621 off += sizeof(struct in_addr);
1622 break;
1623
1624 case IPOPT_TS_PRESPEC:
1625 if (off + sizeof(n_time) +
1626 sizeof(struct in_addr) > optlen) {
1627 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1628 goto bad;
1629 }
1630 (void)memcpy(&ipaddr.sin_addr, sin,
1631 sizeof(struct in_addr));
1632 if (ifa_ifwithaddr((SA)&ipaddr) == 0)
1633 continue;
1634 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1635 off += sizeof(struct in_addr);
1636 break;
1637
1638 default:
1639 code = &cp[IPOPT_OFFSET + 1] - (u_char *)ip;
1640 goto bad;
1641 }
1642 ntime = iptime();
1643 (void)memcpy(cp + off, &ntime, sizeof(n_time));
1644 cp[IPOPT_OFFSET] += sizeof(n_time);
1645 }
1646 }
1647 if (forward && ipforwarding) {
1648 ip_forward(m, &cro, 1, next_hop);
1649 return (1);
1650 }
1651 return (0);
1652bad:
1653 icmp_error(m, type, code, 0, 0);
1654 ipstat.ips_badoptions++;
1655 return (1);
1656}
1657
1658/*
1659 * Given address of next destination (final or next hop),
1660 * return internet address info of interface to be used to get there.
1661 */
1662struct in_ifaddr *
1663ip_rtaddr(dst, rt)
1664 struct in_addr dst;
1665 struct route *rt;
1666{
1667 register struct sockaddr_in *sin;
1668
1669 sin = (struct sockaddr_in *)&rt->ro_dst;
1670
1671 if (rt->ro_rt == 0 ||
1672 !(rt->ro_rt->rt_flags & RTF_UP) ||
1673 dst.s_addr != sin->sin_addr.s_addr) {
1674 if (rt->ro_rt) {
1675 RTFREE(rt->ro_rt);
1676 rt->ro_rt = 0;
1677 }
1678 sin->sin_family = AF_INET;
1679 sin->sin_len = sizeof(*sin);
1680 sin->sin_addr = dst;
1681
1682 rtalloc_ign(rt, RTF_PRCLONING);
1683 }
1684 if (rt->ro_rt == 0)
1685 return ((struct in_ifaddr *)0);
1686 return (ifatoia(rt->ro_rt->rt_ifa));
1687}
1688
1689/*
1690 * Save incoming source route for use in replies,
1691 * to be picked up later by ip_srcroute if the receiver is interested.
1692 */
1693static void
1694save_rte(option, dst)
1695 u_char *option;
1696 struct in_addr dst;
1697{
1698 unsigned olen;
1699
1700 olen = option[IPOPT_OLEN];
1701#ifdef DIAGNOSTIC
1702 if (ipprintfs)
1703 printf("save_rte: olen %d\n", olen);
1704#endif
1705 if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
1706 return;
1707 bcopy(option, ip_srcrt.srcopt, olen);
1708 ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1709 ip_srcrt.dst = dst;
1710}
1711
1712/*
1713 * Retrieve incoming source route for use in replies,
1714 * in the same form used by setsockopt.
1715 * The first hop is placed before the options, will be removed later.
1716 */
1717struct mbuf *
1718ip_srcroute()
1719{
1720 register struct in_addr *p, *q;
1721 register struct mbuf *m;
1722
1723 if (ip_nhops == 0)
1724 return ((struct mbuf *)0);
1725 m = m_get(M_DONTWAIT, MT_HEADER);
1726 if (m == 0)
1727 return ((struct mbuf *)0);
1728
1729#define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1730
1731 /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1732 m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
1733 OPTSIZ;
1734#ifdef DIAGNOSTIC
1735 if (ipprintfs)
1736 printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
1737#endif
1738
1739 /*
1740 * First save first hop for return route
1741 */
1742 p = &ip_srcrt.route[ip_nhops - 1];
1743 *(mtod(m, struct in_addr *)) = *p--;
1744#ifdef DIAGNOSTIC
1745 if (ipprintfs)
1746 printf(" hops %lx", (u_long)ntohl(mtod(m, struct in_addr *)->s_addr));
1747#endif
1748
1749 /*
1750 * Copy option fields and padding (nop) to mbuf.
1751 */
1752 ip_srcrt.nop = IPOPT_NOP;
1753 ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1754 (void)memcpy(mtod(m, caddr_t) + sizeof(struct in_addr),
1755 &ip_srcrt.nop, OPTSIZ);
1756 q = (struct in_addr *)(mtod(m, caddr_t) +
1757 sizeof(struct in_addr) + OPTSIZ);
1758#undef OPTSIZ
1759 /*
1760 * Record return path as an IP source route,
1761 * reversing the path (pointers are now aligned).
1762 */
1763 while (p >= ip_srcrt.route) {
1764#ifdef DIAGNOSTIC
1765 if (ipprintfs)
1766 printf(" %lx", (u_long)ntohl(q->s_addr));
1767#endif
1768 *q++ = *p--;
1769 }
1770 /*
1771 * Last hop goes to final destination.
1772 */
1773 *q = ip_srcrt.dst;
1774#ifdef DIAGNOSTIC
1775 if (ipprintfs)
1776 printf(" %lx\n", (u_long)ntohl(q->s_addr));
1777#endif
1778 return (m);
1779}
1780
1781/*
1782 * Strip out IP options, at higher
1783 * level protocol in the kernel.
1784 * Second argument is buffer to which options
1785 * will be moved, and return value is their length.
1786 * XXX should be deleted; last arg currently ignored.
1787 */
1788void
1789ip_stripoptions(m, mopt)
1790 register struct mbuf *m;
1791 struct mbuf *mopt;
1792{
1793 register int i;
1794 struct ip *ip = mtod(m, struct ip *);
1795 register caddr_t opts;
1796 int olen;
1797
1798 olen = (ip->ip_hl << 2) - sizeof (struct ip);
1799 opts = (caddr_t)(ip + 1);
1800 i = m->m_len - (sizeof (struct ip) + olen);
1801 bcopy(opts + olen, opts, (unsigned)i);
1802 m->m_len -= olen;
1803 if (m->m_flags & M_PKTHDR)
1804 m->m_pkthdr.len -= olen;
1805 ip->ip_v = IPVERSION;
1806 ip->ip_hl = sizeof(struct ip) >> 2;
1807}
1808
1809u_char inetctlerrmap[PRC_NCMDS] = {
1810 0, 0, 0, 0,
1811 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1812 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1813 EMSGSIZE, EHOSTUNREACH, 0, 0,
1814 0, 0, EHOSTUNREACH, 0,
1815 ENOPROTOOPT, ECONNREFUSED
1816};
1817
1818/*
1819 * Forward a packet. If some error occurs return the sender
1820 * an icmp packet. Note we can't always generate a meaningful
1821 * icmp message because icmp doesn't have a large enough repertoire
1822 * of codes and types.
1823 *
1824 * If not forwarding, just drop the packet. This could be confusing
1825 * if ipforwarding was zero but some routing protocol was advancing
1826 * us as a gateway to somewhere. However, we must let the routing
1827 * protocol deal with that.
1828 *
1829 * The srcrt parameter indicates whether the packet is being forwarded
1830 * via a source route.
1831 */
1832static void
1833ip_forward(struct mbuf *m, struct route *ro,
1834 int srcrt, struct sockaddr_in *next_hop)
1835{
1836 struct ip *ip = mtod(m, struct ip *);
1837 struct rtentry *rt;
1838 int error, type = 0, code = 0;
1839 struct mbuf *mcopy;
1840 n_long dest;
1841 struct in_addr pkt_dst;
1842 struct ifnet *destifp;
1843#if defined(IPSEC) || defined(FAST_IPSEC)
1844 struct ifnet dummyifp;
1845#endif
1846
1847 dest = 0;
1848 /*
1849 * Cache the destination address of the packet; this may be
1850 * changed by use of 'ipfw fwd'.
1851 */
1852 pkt_dst = next_hop ? next_hop->sin_addr : ip->ip_dst;
1853
1854#ifdef DIAGNOSTIC
1855 if (ipprintfs)
1856 printf("forward: src %lx dst %lx ttl %x\n",
1857 (u_long)ip->ip_src.s_addr, (u_long)pkt_dst.s_addr,
1858 ip->ip_ttl);
1859#endif
1860
1861
1862 if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(pkt_dst) == 0) {
1863 ipstat.ips_cantforward++;
1864 m_freem(m);
1865 return;
1866 }
1867#ifdef IPSTEALTH
1868 if (!ipstealth) {
1869#endif
1870 if (ip->ip_ttl <= IPTTLDEC) {
1871 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS,
1872 dest, 0);
1873 return;
1874 }
1875#ifdef IPSTEALTH
1876 }
1877#endif
1878
1879 if (ip_rtaddr(pkt_dst, ro) == 0) {
1880 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1881 return;
1882 } else
1883 rt = ro->ro_rt;
1884
1885 /*
1886 * Save the IP header and at most 8 bytes of the payload,
1887 * in case we need to generate an ICMP message to the src.
1888 *
1889 * XXX this can be optimized a lot by saving the data in a local
1890 * buffer on the stack (72 bytes at most), and only allocating the
1891 * mbuf if really necessary. The vast majority of the packets
1892 * are forwarded without having to send an ICMP back (either
1893 * because unnecessary, or because rate limited), so we are
1894 * really we are wasting a lot of work here.
1895 *
1896 * We don't use m_copy() because it might return a reference
1897 * to a shared cluster. Both this function and ip_output()
1898 * assume exclusive access to the IP header in `m', so any
1899 * data in a cluster may change before we reach icmp_error().
1900 */
1901 MGET(mcopy, M_DONTWAIT, m->m_type);
1902 if (mcopy != NULL && !m_dup_pkthdr(mcopy, m, M_DONTWAIT)) {
1903 /*
1904 * It's probably ok if the pkthdr dup fails (because
1905 * the deep copy of the tag chain failed), but for now
1906 * be conservative and just discard the copy since
1907 * code below may some day want the tags.
1908 */
1909 m_free(mcopy);
1910 mcopy = NULL;
1911 }
1912 if (mcopy != NULL) {
1913 mcopy->m_len = imin((ip->ip_hl << 2) + 8,
1914 (int)ip->ip_len);
1915 m_copydata(m, 0, mcopy->m_len, mtod(mcopy, caddr_t));
1916 }
1917
1918#ifdef IPSTEALTH
1919 if (!ipstealth) {
1920#endif
1921 ip->ip_ttl -= IPTTLDEC;
1922#ifdef IPSTEALTH
1923 }
1924#endif
1925
1926 /*
1927 * If forwarding packet using same interface that it came in on,
1928 * perhaps should send a redirect to sender to shortcut a hop.
1929 * Only send redirect if source is sending directly to us,
1930 * and if packet was not source routed (or has any options).
1931 * Also, don't send redirect if forwarding using a default route
1932 * or a route modified by a redirect.
1933 */
1934 if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1935 (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1936 satosin(rt_key(rt))->sin_addr.s_addr != 0 &&
1937 ipsendredirects && !srcrt && !next_hop) {
1938#define RTA(rt) ((struct in_ifaddr *)(rt->rt_ifa))
1939 u_long src = ntohl(ip->ip_src.s_addr);
1940
1941 if (RTA(rt) &&
1942 (src & RTA(rt)->ia_subnetmask) == RTA(rt)->ia_subnet) {
1943 if (rt->rt_flags & RTF_GATEWAY)
1944 dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1945 else
1946 dest = pkt_dst.s_addr;
1947 /* Router requirements says to only send host redirects */
1948 type = ICMP_REDIRECT;
1949 code = ICMP_REDIRECT_HOST;
1950#ifdef DIAGNOSTIC
1951 if (ipprintfs)
1952 printf("redirect (%d) to %lx\n", code, (u_long)dest);
1953#endif
1954 }
1955 }
1956
1957 {
1958 struct m_hdr tag;
1959
1960 if (next_hop) {
1961 /* Pass IPFORWARD info if available */
1962
1963 tag.mh_type = MT_TAG;
1964 tag.mh_flags = PACKET_TAG_IPFORWARD;
1965 tag.mh_data = (caddr_t)next_hop;
1966 tag.mh_next = m;
1967 m = (struct mbuf *)&tag;
1968 }
1969 error = ip_output(m, (struct mbuf *)0, ro, IP_FORWARDING, 0, NULL);
1970 }
1971 /*
1972 * Update the ip forwarding cache with the route we used.
1973 * We may want to do this more selectively; not sure.
1974 */
1975 RTCACHE_UPDATE(ro);
1976 if (error)
1977 ipstat.ips_cantforward++;
1978 else {
1979 ipstat.ips_forward++;
1980 if (type)
1981 ipstat.ips_redirectsent++;
1982 else {
| 1377 splx(s);
1378}
1379
1380/*
1381 * Drain off all datagram fragments.
1382 */
1383void
1384ip_drain()
1385{
1386 int i;
1387
1388 IPQ_LOCK();
1389 for (i = 0; i < IPREASS_NHASH; i++) {
1390 while(!TAILQ_EMPTY(&ipq[i])) {
1391 ipstat.ips_fragdropped +=
1392 TAILQ_FIRST(&ipq[i])->ipq_nfrags;
1393 ip_freef(&ipq[i], TAILQ_FIRST(&ipq[i]));
1394 }
1395 }
1396 IPQ_UNLOCK();
1397 in_rtqdrain();
1398}
1399
1400/*
1401 * Do option processing on a datagram,
1402 * possibly discarding it if bad options are encountered,
1403 * or forwarding it if source-routed.
1404 * The pass argument is used when operating in the IPSTEALTH
1405 * mode to tell what options to process:
1406 * [LS]SRR (pass 0) or the others (pass 1).
1407 * The reason for as many as two passes is that when doing IPSTEALTH,
1408 * non-routing options should be processed only if the packet is for us.
1409 * Returns 1 if packet has been forwarded/freed,
1410 * 0 if the packet should be processed further.
1411 */
1412static int
1413ip_dooptions(struct mbuf *m, int pass, struct sockaddr_in *next_hop)
1414{
1415 struct ip *ip = mtod(m, struct ip *);
1416 u_char *cp;
1417 struct in_ifaddr *ia;
1418 int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
1419 struct in_addr *sin, dst;
1420 n_time ntime;
1421 struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET };
1422 struct route cro; /* copy of cached route */
1423
1424 /*
1425 * Grab a copy of the route cache in case we need
1426 * to update to reflect source routing or the like.
1427 * Could optimize this to do it later...
1428 */
1429 RTCACHE_GET(&cro);
1430
1431 dst = ip->ip_dst;
1432 cp = (u_char *)(ip + 1);
1433 cnt = (ip->ip_hl << 2) - sizeof (struct ip);
1434 for (; cnt > 0; cnt -= optlen, cp += optlen) {
1435 opt = cp[IPOPT_OPTVAL];
1436 if (opt == IPOPT_EOL)
1437 break;
1438 if (opt == IPOPT_NOP)
1439 optlen = 1;
1440 else {
1441 if (cnt < IPOPT_OLEN + sizeof(*cp)) {
1442 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1443 goto bad;
1444 }
1445 optlen = cp[IPOPT_OLEN];
1446 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) {
1447 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1448 goto bad;
1449 }
1450 }
1451 switch (opt) {
1452
1453 default:
1454 break;
1455
1456 /*
1457 * Source routing with record.
1458 * Find interface with current destination address.
1459 * If none on this machine then drop if strictly routed,
1460 * or do nothing if loosely routed.
1461 * Record interface address and bring up next address
1462 * component. If strictly routed make sure next
1463 * address is on directly accessible net.
1464 */
1465 case IPOPT_LSRR:
1466 case IPOPT_SSRR:
1467#ifdef IPSTEALTH
1468 if (ipstealth && pass > 0)
1469 break;
1470#endif
1471 if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1472 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1473 goto bad;
1474 }
1475 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1476 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1477 goto bad;
1478 }
1479 ipaddr.sin_addr = ip->ip_dst;
1480 ia = (struct in_ifaddr *)
1481 ifa_ifwithaddr((struct sockaddr *)&ipaddr);
1482 if (ia == 0) {
1483 if (opt == IPOPT_SSRR) {
1484 type = ICMP_UNREACH;
1485 code = ICMP_UNREACH_SRCFAIL;
1486 goto bad;
1487 }
1488 if (!ip_dosourceroute)
1489 goto nosourcerouting;
1490 /*
1491 * Loose routing, and not at next destination
1492 * yet; nothing to do except forward.
1493 */
1494 break;
1495 }
1496 off--; /* 0 origin */
1497 if (off > optlen - (int)sizeof(struct in_addr)) {
1498 /*
1499 * End of source route. Should be for us.
1500 */
1501 if (!ip_acceptsourceroute)
1502 goto nosourcerouting;
1503 save_rte(cp, ip->ip_src);
1504 break;
1505 }
1506#ifdef IPSTEALTH
1507 if (ipstealth)
1508 goto dropit;
1509#endif
1510 if (!ip_dosourceroute) {
1511 if (ipforwarding) {
1512 char buf[16]; /* aaa.bbb.ccc.ddd\0 */
1513 /*
1514 * Acting as a router, so generate ICMP
1515 */
1516nosourcerouting:
1517 strcpy(buf, inet_ntoa(ip->ip_dst));
1518 log(LOG_WARNING,
1519 "attempted source route from %s to %s\n",
1520 inet_ntoa(ip->ip_src), buf);
1521 type = ICMP_UNREACH;
1522 code = ICMP_UNREACH_SRCFAIL;
1523 goto bad;
1524 } else {
1525 /*
1526 * Not acting as a router, so silently drop.
1527 */
1528#ifdef IPSTEALTH
1529dropit:
1530#endif
1531 ipstat.ips_cantforward++;
1532 m_freem(m);
1533 return (1);
1534 }
1535 }
1536
1537 /*
1538 * locate outgoing interface
1539 */
1540 (void)memcpy(&ipaddr.sin_addr, cp + off,
1541 sizeof(ipaddr.sin_addr));
1542
1543 if (opt == IPOPT_SSRR) {
1544#define INA struct in_ifaddr *
1545#define SA struct sockaddr *
1546 if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr)) == 0)
1547 ia = (INA)ifa_ifwithnet((SA)&ipaddr);
1548 } else
1549 ia = ip_rtaddr(ipaddr.sin_addr, &cro);
1550 if (ia == 0) {
1551 type = ICMP_UNREACH;
1552 code = ICMP_UNREACH_SRCFAIL;
1553 goto bad;
1554 }
1555 ip->ip_dst = ipaddr.sin_addr;
1556 (void)memcpy(cp + off, &(IA_SIN(ia)->sin_addr),
1557 sizeof(struct in_addr));
1558 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1559 /*
1560 * Let ip_intr's mcast routing check handle mcast pkts
1561 */
1562 forward = !IN_MULTICAST(ntohl(ip->ip_dst.s_addr));
1563 break;
1564
1565 case IPOPT_RR:
1566#ifdef IPSTEALTH
1567 if (ipstealth && pass == 0)
1568 break;
1569#endif
1570 if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1571 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1572 goto bad;
1573 }
1574 if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1575 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1576 goto bad;
1577 }
1578 /*
1579 * If no space remains, ignore.
1580 */
1581 off--; /* 0 origin */
1582 if (off > optlen - (int)sizeof(struct in_addr))
1583 break;
1584 (void)memcpy(&ipaddr.sin_addr, &ip->ip_dst,
1585 sizeof(ipaddr.sin_addr));
1586 /*
1587 * locate outgoing interface; if we're the destination,
1588 * use the incoming interface (should be same).
1589 */
1590 if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 &&
1591 (ia = ip_rtaddr(ipaddr.sin_addr, &cro)) == 0) {
1592 type = ICMP_UNREACH;
1593 code = ICMP_UNREACH_HOST;
1594 goto bad;
1595 }
1596 (void)memcpy(cp + off, &(IA_SIN(ia)->sin_addr),
1597 sizeof(struct in_addr));
1598 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1599 break;
1600
1601 case IPOPT_TS:
1602#ifdef IPSTEALTH
1603 if (ipstealth && pass == 0)
1604 break;
1605#endif
1606 code = cp - (u_char *)ip;
1607 if (optlen < 4 || optlen > 40) {
1608 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1609 goto bad;
1610 }
1611 if ((off = cp[IPOPT_OFFSET]) < 5) {
1612 code = &cp[IPOPT_OLEN] - (u_char *)ip;
1613 goto bad;
1614 }
1615 if (off > optlen - (int)sizeof(int32_t)) {
1616 cp[IPOPT_OFFSET + 1] += (1 << 4);
1617 if ((cp[IPOPT_OFFSET + 1] & 0xf0) == 0) {
1618 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1619 goto bad;
1620 }
1621 break;
1622 }
1623 off--; /* 0 origin */
1624 sin = (struct in_addr *)(cp + off);
1625 switch (cp[IPOPT_OFFSET + 1] & 0x0f) {
1626
1627 case IPOPT_TS_TSONLY:
1628 break;
1629
1630 case IPOPT_TS_TSANDADDR:
1631 if (off + sizeof(n_time) +
1632 sizeof(struct in_addr) > optlen) {
1633 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1634 goto bad;
1635 }
1636 ipaddr.sin_addr = dst;
1637 ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
1638 m->m_pkthdr.rcvif);
1639 if (ia == 0)
1640 continue;
1641 (void)memcpy(sin, &IA_SIN(ia)->sin_addr,
1642 sizeof(struct in_addr));
1643 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1644 off += sizeof(struct in_addr);
1645 break;
1646
1647 case IPOPT_TS_PRESPEC:
1648 if (off + sizeof(n_time) +
1649 sizeof(struct in_addr) > optlen) {
1650 code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1651 goto bad;
1652 }
1653 (void)memcpy(&ipaddr.sin_addr, sin,
1654 sizeof(struct in_addr));
1655 if (ifa_ifwithaddr((SA)&ipaddr) == 0)
1656 continue;
1657 cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1658 off += sizeof(struct in_addr);
1659 break;
1660
1661 default:
1662 code = &cp[IPOPT_OFFSET + 1] - (u_char *)ip;
1663 goto bad;
1664 }
1665 ntime = iptime();
1666 (void)memcpy(cp + off, &ntime, sizeof(n_time));
1667 cp[IPOPT_OFFSET] += sizeof(n_time);
1668 }
1669 }
1670 if (forward && ipforwarding) {
1671 ip_forward(m, &cro, 1, next_hop);
1672 return (1);
1673 }
1674 return (0);
1675bad:
1676 icmp_error(m, type, code, 0, 0);
1677 ipstat.ips_badoptions++;
1678 return (1);
1679}
1680
1681/*
1682 * Given address of next destination (final or next hop),
1683 * return internet address info of interface to be used to get there.
1684 */
1685struct in_ifaddr *
1686ip_rtaddr(dst, rt)
1687 struct in_addr dst;
1688 struct route *rt;
1689{
1690 register struct sockaddr_in *sin;
1691
1692 sin = (struct sockaddr_in *)&rt->ro_dst;
1693
1694 if (rt->ro_rt == 0 ||
1695 !(rt->ro_rt->rt_flags & RTF_UP) ||
1696 dst.s_addr != sin->sin_addr.s_addr) {
1697 if (rt->ro_rt) {
1698 RTFREE(rt->ro_rt);
1699 rt->ro_rt = 0;
1700 }
1701 sin->sin_family = AF_INET;
1702 sin->sin_len = sizeof(*sin);
1703 sin->sin_addr = dst;
1704
1705 rtalloc_ign(rt, RTF_PRCLONING);
1706 }
1707 if (rt->ro_rt == 0)
1708 return ((struct in_ifaddr *)0);
1709 return (ifatoia(rt->ro_rt->rt_ifa));
1710}
1711
1712/*
1713 * Save incoming source route for use in replies,
1714 * to be picked up later by ip_srcroute if the receiver is interested.
1715 */
1716static void
1717save_rte(option, dst)
1718 u_char *option;
1719 struct in_addr dst;
1720{
1721 unsigned olen;
1722
1723 olen = option[IPOPT_OLEN];
1724#ifdef DIAGNOSTIC
1725 if (ipprintfs)
1726 printf("save_rte: olen %d\n", olen);
1727#endif
1728 if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
1729 return;
1730 bcopy(option, ip_srcrt.srcopt, olen);
1731 ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1732 ip_srcrt.dst = dst;
1733}
1734
1735/*
1736 * Retrieve incoming source route for use in replies,
1737 * in the same form used by setsockopt.
1738 * The first hop is placed before the options, will be removed later.
1739 */
1740struct mbuf *
1741ip_srcroute()
1742{
1743 register struct in_addr *p, *q;
1744 register struct mbuf *m;
1745
1746 if (ip_nhops == 0)
1747 return ((struct mbuf *)0);
1748 m = m_get(M_DONTWAIT, MT_HEADER);
1749 if (m == 0)
1750 return ((struct mbuf *)0);
1751
1752#define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1753
1754 /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1755 m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
1756 OPTSIZ;
1757#ifdef DIAGNOSTIC
1758 if (ipprintfs)
1759 printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
1760#endif
1761
1762 /*
1763 * First save first hop for return route
1764 */
1765 p = &ip_srcrt.route[ip_nhops - 1];
1766 *(mtod(m, struct in_addr *)) = *p--;
1767#ifdef DIAGNOSTIC
1768 if (ipprintfs)
1769 printf(" hops %lx", (u_long)ntohl(mtod(m, struct in_addr *)->s_addr));
1770#endif
1771
1772 /*
1773 * Copy option fields and padding (nop) to mbuf.
1774 */
1775 ip_srcrt.nop = IPOPT_NOP;
1776 ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1777 (void)memcpy(mtod(m, caddr_t) + sizeof(struct in_addr),
1778 &ip_srcrt.nop, OPTSIZ);
1779 q = (struct in_addr *)(mtod(m, caddr_t) +
1780 sizeof(struct in_addr) + OPTSIZ);
1781#undef OPTSIZ
1782 /*
1783 * Record return path as an IP source route,
1784 * reversing the path (pointers are now aligned).
1785 */
1786 while (p >= ip_srcrt.route) {
1787#ifdef DIAGNOSTIC
1788 if (ipprintfs)
1789 printf(" %lx", (u_long)ntohl(q->s_addr));
1790#endif
1791 *q++ = *p--;
1792 }
1793 /*
1794 * Last hop goes to final destination.
1795 */
1796 *q = ip_srcrt.dst;
1797#ifdef DIAGNOSTIC
1798 if (ipprintfs)
1799 printf(" %lx\n", (u_long)ntohl(q->s_addr));
1800#endif
1801 return (m);
1802}
1803
1804/*
1805 * Strip out IP options, at higher
1806 * level protocol in the kernel.
1807 * Second argument is buffer to which options
1808 * will be moved, and return value is their length.
1809 * XXX should be deleted; last arg currently ignored.
1810 */
1811void
1812ip_stripoptions(m, mopt)
1813 register struct mbuf *m;
1814 struct mbuf *mopt;
1815{
1816 register int i;
1817 struct ip *ip = mtod(m, struct ip *);
1818 register caddr_t opts;
1819 int olen;
1820
1821 olen = (ip->ip_hl << 2) - sizeof (struct ip);
1822 opts = (caddr_t)(ip + 1);
1823 i = m->m_len - (sizeof (struct ip) + olen);
1824 bcopy(opts + olen, opts, (unsigned)i);
1825 m->m_len -= olen;
1826 if (m->m_flags & M_PKTHDR)
1827 m->m_pkthdr.len -= olen;
1828 ip->ip_v = IPVERSION;
1829 ip->ip_hl = sizeof(struct ip) >> 2;
1830}
1831
1832u_char inetctlerrmap[PRC_NCMDS] = {
1833 0, 0, 0, 0,
1834 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1835 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1836 EMSGSIZE, EHOSTUNREACH, 0, 0,
1837 0, 0, EHOSTUNREACH, 0,
1838 ENOPROTOOPT, ECONNREFUSED
1839};
1840
1841/*
1842 * Forward a packet. If some error occurs return the sender
1843 * an icmp packet. Note we can't always generate a meaningful
1844 * icmp message because icmp doesn't have a large enough repertoire
1845 * of codes and types.
1846 *
1847 * If not forwarding, just drop the packet. This could be confusing
1848 * if ipforwarding was zero but some routing protocol was advancing
1849 * us as a gateway to somewhere. However, we must let the routing
1850 * protocol deal with that.
1851 *
1852 * The srcrt parameter indicates whether the packet is being forwarded
1853 * via a source route.
1854 */
1855static void
1856ip_forward(struct mbuf *m, struct route *ro,
1857 int srcrt, struct sockaddr_in *next_hop)
1858{
1859 struct ip *ip = mtod(m, struct ip *);
1860 struct rtentry *rt;
1861 int error, type = 0, code = 0;
1862 struct mbuf *mcopy;
1863 n_long dest;
1864 struct in_addr pkt_dst;
1865 struct ifnet *destifp;
1866#if defined(IPSEC) || defined(FAST_IPSEC)
1867 struct ifnet dummyifp;
1868#endif
1869
1870 dest = 0;
1871 /*
1872 * Cache the destination address of the packet; this may be
1873 * changed by use of 'ipfw fwd'.
1874 */
1875 pkt_dst = next_hop ? next_hop->sin_addr : ip->ip_dst;
1876
1877#ifdef DIAGNOSTIC
1878 if (ipprintfs)
1879 printf("forward: src %lx dst %lx ttl %x\n",
1880 (u_long)ip->ip_src.s_addr, (u_long)pkt_dst.s_addr,
1881 ip->ip_ttl);
1882#endif
1883
1884
1885 if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(pkt_dst) == 0) {
1886 ipstat.ips_cantforward++;
1887 m_freem(m);
1888 return;
1889 }
1890#ifdef IPSTEALTH
1891 if (!ipstealth) {
1892#endif
1893 if (ip->ip_ttl <= IPTTLDEC) {
1894 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS,
1895 dest, 0);
1896 return;
1897 }
1898#ifdef IPSTEALTH
1899 }
1900#endif
1901
1902 if (ip_rtaddr(pkt_dst, ro) == 0) {
1903 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1904 return;
1905 } else
1906 rt = ro->ro_rt;
1907
1908 /*
1909 * Save the IP header and at most 8 bytes of the payload,
1910 * in case we need to generate an ICMP message to the src.
1911 *
1912 * XXX this can be optimized a lot by saving the data in a local
1913 * buffer on the stack (72 bytes at most), and only allocating the
1914 * mbuf if really necessary. The vast majority of the packets
1915 * are forwarded without having to send an ICMP back (either
1916 * because unnecessary, or because rate limited), so we are
1917 * really we are wasting a lot of work here.
1918 *
1919 * We don't use m_copy() because it might return a reference
1920 * to a shared cluster. Both this function and ip_output()
1921 * assume exclusive access to the IP header in `m', so any
1922 * data in a cluster may change before we reach icmp_error().
1923 */
1924 MGET(mcopy, M_DONTWAIT, m->m_type);
1925 if (mcopy != NULL && !m_dup_pkthdr(mcopy, m, M_DONTWAIT)) {
1926 /*
1927 * It's probably ok if the pkthdr dup fails (because
1928 * the deep copy of the tag chain failed), but for now
1929 * be conservative and just discard the copy since
1930 * code below may some day want the tags.
1931 */
1932 m_free(mcopy);
1933 mcopy = NULL;
1934 }
1935 if (mcopy != NULL) {
1936 mcopy->m_len = imin((ip->ip_hl << 2) + 8,
1937 (int)ip->ip_len);
1938 m_copydata(m, 0, mcopy->m_len, mtod(mcopy, caddr_t));
1939 }
1940
1941#ifdef IPSTEALTH
1942 if (!ipstealth) {
1943#endif
1944 ip->ip_ttl -= IPTTLDEC;
1945#ifdef IPSTEALTH
1946 }
1947#endif
1948
1949 /*
1950 * If forwarding packet using same interface that it came in on,
1951 * perhaps should send a redirect to sender to shortcut a hop.
1952 * Only send redirect if source is sending directly to us,
1953 * and if packet was not source routed (or has any options).
1954 * Also, don't send redirect if forwarding using a default route
1955 * or a route modified by a redirect.
1956 */
1957 if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1958 (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1959 satosin(rt_key(rt))->sin_addr.s_addr != 0 &&
1960 ipsendredirects && !srcrt && !next_hop) {
1961#define RTA(rt) ((struct in_ifaddr *)(rt->rt_ifa))
1962 u_long src = ntohl(ip->ip_src.s_addr);
1963
1964 if (RTA(rt) &&
1965 (src & RTA(rt)->ia_subnetmask) == RTA(rt)->ia_subnet) {
1966 if (rt->rt_flags & RTF_GATEWAY)
1967 dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1968 else
1969 dest = pkt_dst.s_addr;
1970 /* Router requirements says to only send host redirects */
1971 type = ICMP_REDIRECT;
1972 code = ICMP_REDIRECT_HOST;
1973#ifdef DIAGNOSTIC
1974 if (ipprintfs)
1975 printf("redirect (%d) to %lx\n", code, (u_long)dest);
1976#endif
1977 }
1978 }
1979
1980 {
1981 struct m_hdr tag;
1982
1983 if (next_hop) {
1984 /* Pass IPFORWARD info if available */
1985
1986 tag.mh_type = MT_TAG;
1987 tag.mh_flags = PACKET_TAG_IPFORWARD;
1988 tag.mh_data = (caddr_t)next_hop;
1989 tag.mh_next = m;
1990 m = (struct mbuf *)&tag;
1991 }
1992 error = ip_output(m, (struct mbuf *)0, ro, IP_FORWARDING, 0, NULL);
1993 }
1994 /*
1995 * Update the ip forwarding cache with the route we used.
1996 * We may want to do this more selectively; not sure.
1997 */
1998 RTCACHE_UPDATE(ro);
1999 if (error)
2000 ipstat.ips_cantforward++;
2001 else {
2002 ipstat.ips_forward++;
2003 if (type)
2004 ipstat.ips_redirectsent++;
2005 else {
|
1983 if (mcopy) {
1984 ipflow_create(ro, mcopy);
| 2006 if (mcopy)
|
1985 m_freem(mcopy);
| 2007 m_freem(mcopy);
|
1986 }
| |
1987 return;
1988 }
1989 }
1990 if (mcopy == NULL)
1991 return;
1992 destifp = NULL;
1993
1994 switch (error) {
1995
1996 case 0: /* forwarded, but need redirect */
1997 /* type, code set above */
1998 break;
1999
2000 case ENETUNREACH: /* shouldn't happen, checked above */
2001 case EHOSTUNREACH:
2002 case ENETDOWN:
2003 case EHOSTDOWN:
2004 default:
2005 type = ICMP_UNREACH;
2006 code = ICMP_UNREACH_HOST;
2007 break;
2008
2009 case EMSGSIZE:
2010 type = ICMP_UNREACH;
2011 code = ICMP_UNREACH_NEEDFRAG;
2012#ifdef IPSEC
2013 /*
2014 * If the packet is routed over IPsec tunnel, tell the
2015 * originator the tunnel MTU.
2016 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
2017 * XXX quickhack!!!
2018 */
2019 if (ro->ro_rt) {
2020 struct secpolicy *sp = NULL;
2021 int ipsecerror;
2022 int ipsechdr;
2023
2024 sp = ipsec4_getpolicybyaddr(mcopy,
2025 IPSEC_DIR_OUTBOUND,
2026 IP_FORWARDING,
2027 &ipsecerror);
2028
2029 if (sp == NULL)
2030 destifp = ro->ro_rt->rt_ifp;
2031 else {
2032 /* count IPsec header size */
2033 ipsechdr = ipsec4_hdrsiz(mcopy,
2034 IPSEC_DIR_OUTBOUND,
2035 NULL);
2036
2037 /*
2038 * find the correct route for outer IPv4
2039 * header, compute tunnel MTU.
2040 *
2041 * XXX BUG ALERT
2042 * The "dummyifp" code relies upon the fact
2043 * that icmp_error() touches only ifp->if_mtu.
2044 */
2045 /*XXX*/
2046 destifp = NULL;
2047 if (sp->req != NULL
2048 && sp->req->sav != NULL
2049 && sp->req->sav->sah != NULL) {
2050 struct route *saro;
2051 saro = &sp->req->sav->sah->sa_route;
2052 if (saro->ro_rt && saro->ro_rt->rt_ifp) {
2053 dummyifp.if_mtu =
2054 saro->ro_rt->rt_ifp->if_mtu;
2055 dummyifp.if_mtu -= ipsechdr;
2056 destifp = &dummyifp;
2057 }
2058 }
2059
2060 key_freesp(sp);
2061 }
2062 }
2063#elif FAST_IPSEC
2064 /*
2065 * If the packet is routed over IPsec tunnel, tell the
2066 * originator the tunnel MTU.
2067 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
2068 * XXX quickhack!!!
2069 */
2070 if (ro->ro_rt) {
2071 struct secpolicy *sp = NULL;
2072 int ipsecerror;
2073 int ipsechdr;
2074
2075 sp = ipsec_getpolicybyaddr(mcopy,
2076 IPSEC_DIR_OUTBOUND,
2077 IP_FORWARDING,
2078 &ipsecerror);
2079
2080 if (sp == NULL)
2081 destifp = ro->ro_rt->rt_ifp;
2082 else {
2083 /* count IPsec header size */
2084 ipsechdr = ipsec4_hdrsiz(mcopy,
2085 IPSEC_DIR_OUTBOUND,
2086 NULL);
2087
2088 /*
2089 * find the correct route for outer IPv4
2090 * header, compute tunnel MTU.
2091 *
2092 * XXX BUG ALERT
2093 * The "dummyifp" code relies upon the fact
2094 * that icmp_error() touches only ifp->if_mtu.
2095 */
2096 /*XXX*/
2097 destifp = NULL;
2098 if (sp->req != NULL
2099 && sp->req->sav != NULL
2100 && sp->req->sav->sah != NULL) {
2101 struct route *saro;
2102 saro = &sp->req->sav->sah->sa_route;
2103 if (saro->ro_rt && saro->ro_rt->rt_ifp) {
2104 dummyifp.if_mtu =
2105 saro->ro_rt->rt_ifp->if_mtu;
2106 dummyifp.if_mtu -= ipsechdr;
2107 destifp = &dummyifp;
2108 }
2109 }
2110
2111 KEY_FREESP(&sp);
2112 }
2113 }
2114#else /* !IPSEC && !FAST_IPSEC */
2115 if (ro->ro_rt)
2116 destifp = ro->ro_rt->rt_ifp;
2117#endif /*IPSEC*/
2118 ipstat.ips_cantfrag++;
2119 break;
2120
2121 case ENOBUFS:
2122 /*
2123 * A router should not generate ICMP_SOURCEQUENCH as
2124 * required in RFC1812 Requirements for IP Version 4 Routers.
2125 * Source quench could be a big problem under DoS attacks,
2126 * or if the underlying interface is rate-limited.
2127 * Those who need source quench packets may re-enable them
2128 * via the net.inet.ip.sendsourcequench sysctl.
2129 */
2130 if (ip_sendsourcequench == 0) {
2131 m_freem(mcopy);
2132 return;
2133 } else {
2134 type = ICMP_SOURCEQUENCH;
2135 code = 0;
2136 }
2137 break;
2138
2139 case EACCES: /* ipfw denied packet */
2140 m_freem(mcopy);
2141 return;
2142 }
2143 icmp_error(mcopy, type, code, dest, destifp);
2144}
2145
2146void
2147ip_savecontrol(inp, mp, ip, m)
2148 register struct inpcb *inp;
2149 register struct mbuf **mp;
2150 register struct ip *ip;
2151 register struct mbuf *m;
2152{
2153 if (inp->inp_socket->so_options & SO_TIMESTAMP) {
2154 struct timeval tv;
2155
2156 microtime(&tv);
2157 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
2158 SCM_TIMESTAMP, SOL_SOCKET);
2159 if (*mp)
2160 mp = &(*mp)->m_next;
2161 }
2162 if (inp->inp_flags & INP_RECVDSTADDR) {
2163 *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
2164 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
2165 if (*mp)
2166 mp = &(*mp)->m_next;
2167 }
2168 if (inp->inp_flags & INP_RECVTTL) {
2169 *mp = sbcreatecontrol((caddr_t) &ip->ip_ttl,
2170 sizeof(u_char), IP_RECVTTL, IPPROTO_IP);
2171 if (*mp)
2172 mp = &(*mp)->m_next;
2173 }
2174#ifdef notyet
2175 /* XXX
2176 * Moving these out of udp_input() made them even more broken
2177 * than they already were.
2178 */
2179 /* options were tossed already */
2180 if (inp->inp_flags & INP_RECVOPTS) {
2181 *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
2182 sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
2183 if (*mp)
2184 mp = &(*mp)->m_next;
2185 }
2186 /* ip_srcroute doesn't do what we want here, need to fix */
2187 if (inp->inp_flags & INP_RECVRETOPTS) {
2188 *mp = sbcreatecontrol((caddr_t) ip_srcroute(),
2189 sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
2190 if (*mp)
2191 mp = &(*mp)->m_next;
2192 }
2193#endif
2194 if (inp->inp_flags & INP_RECVIF) {
2195 struct ifnet *ifp;
2196 struct sdlbuf {
2197 struct sockaddr_dl sdl;
2198 u_char pad[32];
2199 } sdlbuf;
2200 struct sockaddr_dl *sdp;
2201 struct sockaddr_dl *sdl2 = &sdlbuf.sdl;
2202
2203 if (((ifp = m->m_pkthdr.rcvif))
2204 && ( ifp->if_index && (ifp->if_index <= if_index))) {
2205 sdp = (struct sockaddr_dl *)
2206 (ifaddr_byindex(ifp->if_index)->ifa_addr);
2207 /*
2208 * Change our mind and don't try copy.
2209 */
2210 if ((sdp->sdl_family != AF_LINK)
2211 || (sdp->sdl_len > sizeof(sdlbuf))) {
2212 goto makedummy;
2213 }
2214 bcopy(sdp, sdl2, sdp->sdl_len);
2215 } else {
2216makedummy:
2217 sdl2->sdl_len
2218 = offsetof(struct sockaddr_dl, sdl_data[0]);
2219 sdl2->sdl_family = AF_LINK;
2220 sdl2->sdl_index = 0;
2221 sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0;
2222 }
2223 *mp = sbcreatecontrol((caddr_t) sdl2, sdl2->sdl_len,
2224 IP_RECVIF, IPPROTO_IP);
2225 if (*mp)
2226 mp = &(*mp)->m_next;
2227 }
2228}
2229
2230/*
2231 * XXX these routines are called from the upper part of the kernel.
2232 * They need to be locked when we remove Giant.
2233 *
2234 * They could also be moved to ip_mroute.c, since all the RSVP
2235 * handling is done there already.
2236 */
2237static int ip_rsvp_on;
2238struct socket *ip_rsvpd;
2239int
2240ip_rsvp_init(struct socket *so)
2241{
2242 if (so->so_type != SOCK_RAW ||
2243 so->so_proto->pr_protocol != IPPROTO_RSVP)
2244 return EOPNOTSUPP;
2245
2246 if (ip_rsvpd != NULL)
2247 return EADDRINUSE;
2248
2249 ip_rsvpd = so;
2250 /*
2251 * This may seem silly, but we need to be sure we don't over-increment
2252 * the RSVP counter, in case something slips up.
2253 */
2254 if (!ip_rsvp_on) {
2255 ip_rsvp_on = 1;
2256 rsvp_on++;
2257 }
2258
2259 return 0;
2260}
2261
2262int
2263ip_rsvp_done(void)
2264{
2265 ip_rsvpd = NULL;
2266 /*
2267 * This may seem silly, but we need to be sure we don't over-decrement
2268 * the RSVP counter, in case something slips up.
2269 */
2270 if (ip_rsvp_on) {
2271 ip_rsvp_on = 0;
2272 rsvp_on--;
2273 }
2274 return 0;
2275}
2276
2277void
2278rsvp_input(struct mbuf *m, int off) /* XXX must fixup manually */
2279{
2280 if (rsvp_input_p) { /* call the real one if loaded */
2281 rsvp_input_p(m, off);
2282 return;
2283 }
2284
2285 /* Can still get packets with rsvp_on = 0 if there is a local member
2286 * of the group to which the RSVP packet is addressed. But in this
2287 * case we want to throw the packet away.
2288 */
2289
2290 if (!rsvp_on) {
2291 m_freem(m);
2292 return;
2293 }
2294
2295 if (ip_rsvpd != NULL) {
2296 rip_input(m, off);
2297 return;
2298 }
2299 /* Drop the packet */
2300 m_freem(m);
2301}
| 2008 return;
2009 }
2010 }
2011 if (mcopy == NULL)
2012 return;
2013 destifp = NULL;
2014
2015 switch (error) {
2016
2017 case 0: /* forwarded, but need redirect */
2018 /* type, code set above */
2019 break;
2020
2021 case ENETUNREACH: /* shouldn't happen, checked above */
2022 case EHOSTUNREACH:
2023 case ENETDOWN:
2024 case EHOSTDOWN:
2025 default:
2026 type = ICMP_UNREACH;
2027 code = ICMP_UNREACH_HOST;
2028 break;
2029
2030 case EMSGSIZE:
2031 type = ICMP_UNREACH;
2032 code = ICMP_UNREACH_NEEDFRAG;
2033#ifdef IPSEC
2034 /*
2035 * If the packet is routed over IPsec tunnel, tell the
2036 * originator the tunnel MTU.
2037 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
2038 * XXX quickhack!!!
2039 */
2040 if (ro->ro_rt) {
2041 struct secpolicy *sp = NULL;
2042 int ipsecerror;
2043 int ipsechdr;
2044
2045 sp = ipsec4_getpolicybyaddr(mcopy,
2046 IPSEC_DIR_OUTBOUND,
2047 IP_FORWARDING,
2048 &ipsecerror);
2049
2050 if (sp == NULL)
2051 destifp = ro->ro_rt->rt_ifp;
2052 else {
2053 /* count IPsec header size */
2054 ipsechdr = ipsec4_hdrsiz(mcopy,
2055 IPSEC_DIR_OUTBOUND,
2056 NULL);
2057
2058 /*
2059 * find the correct route for outer IPv4
2060 * header, compute tunnel MTU.
2061 *
2062 * XXX BUG ALERT
2063 * The "dummyifp" code relies upon the fact
2064 * that icmp_error() touches only ifp->if_mtu.
2065 */
2066 /*XXX*/
2067 destifp = NULL;
2068 if (sp->req != NULL
2069 && sp->req->sav != NULL
2070 && sp->req->sav->sah != NULL) {
2071 struct route *saro;
2072 saro = &sp->req->sav->sah->sa_route;
2073 if (saro->ro_rt && saro->ro_rt->rt_ifp) {
2074 dummyifp.if_mtu =
2075 saro->ro_rt->rt_ifp->if_mtu;
2076 dummyifp.if_mtu -= ipsechdr;
2077 destifp = &dummyifp;
2078 }
2079 }
2080
2081 key_freesp(sp);
2082 }
2083 }
2084#elif FAST_IPSEC
2085 /*
2086 * If the packet is routed over IPsec tunnel, tell the
2087 * originator the tunnel MTU.
2088 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
2089 * XXX quickhack!!!
2090 */
2091 if (ro->ro_rt) {
2092 struct secpolicy *sp = NULL;
2093 int ipsecerror;
2094 int ipsechdr;
2095
2096 sp = ipsec_getpolicybyaddr(mcopy,
2097 IPSEC_DIR_OUTBOUND,
2098 IP_FORWARDING,
2099 &ipsecerror);
2100
2101 if (sp == NULL)
2102 destifp = ro->ro_rt->rt_ifp;
2103 else {
2104 /* count IPsec header size */
2105 ipsechdr = ipsec4_hdrsiz(mcopy,
2106 IPSEC_DIR_OUTBOUND,
2107 NULL);
2108
2109 /*
2110 * find the correct route for outer IPv4
2111 * header, compute tunnel MTU.
2112 *
2113 * XXX BUG ALERT
2114 * The "dummyifp" code relies upon the fact
2115 * that icmp_error() touches only ifp->if_mtu.
2116 */
2117 /*XXX*/
2118 destifp = NULL;
2119 if (sp->req != NULL
2120 && sp->req->sav != NULL
2121 && sp->req->sav->sah != NULL) {
2122 struct route *saro;
2123 saro = &sp->req->sav->sah->sa_route;
2124 if (saro->ro_rt && saro->ro_rt->rt_ifp) {
2125 dummyifp.if_mtu =
2126 saro->ro_rt->rt_ifp->if_mtu;
2127 dummyifp.if_mtu -= ipsechdr;
2128 destifp = &dummyifp;
2129 }
2130 }
2131
2132 KEY_FREESP(&sp);
2133 }
2134 }
2135#else /* !IPSEC && !FAST_IPSEC */
2136 if (ro->ro_rt)
2137 destifp = ro->ro_rt->rt_ifp;
2138#endif /*IPSEC*/
2139 ipstat.ips_cantfrag++;
2140 break;
2141
2142 case ENOBUFS:
2143 /*
2144 * A router should not generate ICMP_SOURCEQUENCH as
2145 * required in RFC1812 Requirements for IP Version 4 Routers.
2146 * Source quench could be a big problem under DoS attacks,
2147 * or if the underlying interface is rate-limited.
2148 * Those who need source quench packets may re-enable them
2149 * via the net.inet.ip.sendsourcequench sysctl.
2150 */
2151 if (ip_sendsourcequench == 0) {
2152 m_freem(mcopy);
2153 return;
2154 } else {
2155 type = ICMP_SOURCEQUENCH;
2156 code = 0;
2157 }
2158 break;
2159
2160 case EACCES: /* ipfw denied packet */
2161 m_freem(mcopy);
2162 return;
2163 }
2164 icmp_error(mcopy, type, code, dest, destifp);
2165}
2166
2167void
2168ip_savecontrol(inp, mp, ip, m)
2169 register struct inpcb *inp;
2170 register struct mbuf **mp;
2171 register struct ip *ip;
2172 register struct mbuf *m;
2173{
2174 if (inp->inp_socket->so_options & SO_TIMESTAMP) {
2175 struct timeval tv;
2176
2177 microtime(&tv);
2178 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
2179 SCM_TIMESTAMP, SOL_SOCKET);
2180 if (*mp)
2181 mp = &(*mp)->m_next;
2182 }
2183 if (inp->inp_flags & INP_RECVDSTADDR) {
2184 *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
2185 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
2186 if (*mp)
2187 mp = &(*mp)->m_next;
2188 }
2189 if (inp->inp_flags & INP_RECVTTL) {
2190 *mp = sbcreatecontrol((caddr_t) &ip->ip_ttl,
2191 sizeof(u_char), IP_RECVTTL, IPPROTO_IP);
2192 if (*mp)
2193 mp = &(*mp)->m_next;
2194 }
2195#ifdef notyet
2196 /* XXX
2197 * Moving these out of udp_input() made them even more broken
2198 * than they already were.
2199 */
2200 /* options were tossed already */
2201 if (inp->inp_flags & INP_RECVOPTS) {
2202 *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
2203 sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
2204 if (*mp)
2205 mp = &(*mp)->m_next;
2206 }
2207 /* ip_srcroute doesn't do what we want here, need to fix */
2208 if (inp->inp_flags & INP_RECVRETOPTS) {
2209 *mp = sbcreatecontrol((caddr_t) ip_srcroute(),
2210 sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
2211 if (*mp)
2212 mp = &(*mp)->m_next;
2213 }
2214#endif
2215 if (inp->inp_flags & INP_RECVIF) {
2216 struct ifnet *ifp;
2217 struct sdlbuf {
2218 struct sockaddr_dl sdl;
2219 u_char pad[32];
2220 } sdlbuf;
2221 struct sockaddr_dl *sdp;
2222 struct sockaddr_dl *sdl2 = &sdlbuf.sdl;
2223
2224 if (((ifp = m->m_pkthdr.rcvif))
2225 && ( ifp->if_index && (ifp->if_index <= if_index))) {
2226 sdp = (struct sockaddr_dl *)
2227 (ifaddr_byindex(ifp->if_index)->ifa_addr);
2228 /*
2229 * Change our mind and don't try copy.
2230 */
2231 if ((sdp->sdl_family != AF_LINK)
2232 || (sdp->sdl_len > sizeof(sdlbuf))) {
2233 goto makedummy;
2234 }
2235 bcopy(sdp, sdl2, sdp->sdl_len);
2236 } else {
2237makedummy:
2238 sdl2->sdl_len
2239 = offsetof(struct sockaddr_dl, sdl_data[0]);
2240 sdl2->sdl_family = AF_LINK;
2241 sdl2->sdl_index = 0;
2242 sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0;
2243 }
2244 *mp = sbcreatecontrol((caddr_t) sdl2, sdl2->sdl_len,
2245 IP_RECVIF, IPPROTO_IP);
2246 if (*mp)
2247 mp = &(*mp)->m_next;
2248 }
2249}
2250
2251/*
2252 * XXX these routines are called from the upper part of the kernel.
2253 * They need to be locked when we remove Giant.
2254 *
2255 * They could also be moved to ip_mroute.c, since all the RSVP
2256 * handling is done there already.
2257 */
2258static int ip_rsvp_on;
2259struct socket *ip_rsvpd;
2260int
2261ip_rsvp_init(struct socket *so)
2262{
2263 if (so->so_type != SOCK_RAW ||
2264 so->so_proto->pr_protocol != IPPROTO_RSVP)
2265 return EOPNOTSUPP;
2266
2267 if (ip_rsvpd != NULL)
2268 return EADDRINUSE;
2269
2270 ip_rsvpd = so;
2271 /*
2272 * This may seem silly, but we need to be sure we don't over-increment
2273 * the RSVP counter, in case something slips up.
2274 */
2275 if (!ip_rsvp_on) {
2276 ip_rsvp_on = 1;
2277 rsvp_on++;
2278 }
2279
2280 return 0;
2281}
2282
2283int
2284ip_rsvp_done(void)
2285{
2286 ip_rsvpd = NULL;
2287 /*
2288 * This may seem silly, but we need to be sure we don't over-decrement
2289 * the RSVP counter, in case something slips up.
2290 */
2291 if (ip_rsvp_on) {
2292 ip_rsvp_on = 0;
2293 rsvp_on--;
2294 }
2295 return 0;
2296}
2297
2298void
2299rsvp_input(struct mbuf *m, int off) /* XXX must fixup manually */
2300{
2301 if (rsvp_input_p) { /* call the real one if loaded */
2302 rsvp_input_p(m, off);
2303 return;
2304 }
2305
2306 /* Can still get packets with rsvp_on = 0 if there is a local member
2307 * of the group to which the RSVP packet is addressed. But in this
2308 * case we want to throw the packet away.
2309 */
2310
2311 if (!rsvp_on) {
2312 m_freem(m);
2313 return;
2314 }
2315
2316 if (ip_rsvpd != NULL) {
2317 rip_input(m, off);
2318 return;
2319 }
2320 /* Drop the packet */
2321 m_freem(m);
2322}
|