2 * Copyright (c) 2003, 2004 Jeffrey M. Hsu. All rights reserved.
3 * Copyright (c) 2003, 2004 The DragonFly Project. All rights reserved.
5 * This code is derived from software contributed to The DragonFly Project
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
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12 * notice, this list of conditions and the following disclaimer.
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15 * documentation and/or other materials provided with the distribution.
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17 * contributors may be used to endorse or promote products derived
18 * from this software without specific, prior written permission.
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21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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63 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
66 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94
67 * $FreeBSD: src/sys/netinet/ip_input.c,v 1.130.2.52 2003/03/07 07:01:28 silby Exp $
68 * $DragonFly: src/sys/netinet/ip_input.c,v 1.88 2008/08/22 11:58:49 sephe Exp $
73 #include "opt_bootp.h"
76 #include "opt_ipdivert.h"
77 #include "opt_ipfilter.h"
78 #include "opt_ipstealth.h"
79 #include "opt_ipsec.h"
81 #include <sys/param.h>
82 #include <sys/systm.h>
84 #include <sys/malloc.h>
85 #include <sys/mpipe.h>
86 #include <sys/domain.h>
87 #include <sys/protosw.h>
88 #include <sys/socket.h>
90 #include <sys/globaldata.h>
91 #include <sys/thread.h>
92 #include <sys/kernel.h>
93 #include <sys/syslog.h>
94 #include <sys/sysctl.h>
95 #include <sys/in_cksum.h>
97 #include <machine/stdarg.h>
100 #include <net/if_types.h>
101 #include <net/if_var.h>
102 #include <net/if_dl.h>
103 #include <net/pfil.h>
104 #include <net/route.h>
105 #include <net/netisr.h>
107 #include <netinet/in.h>
108 #include <netinet/in_systm.h>
109 #include <netinet/in_var.h>
110 #include <netinet/ip.h>
111 #include <netinet/in_pcb.h>
112 #include <netinet/ip_var.h>
113 #include <netinet/ip_icmp.h>
115 #include <sys/thread2.h>
116 #include <sys/msgport2.h>
117 #include <net/netmsg2.h>
119 #include <sys/socketvar.h>
121 #include <net/ipfw/ip_fw.h>
122 #include <net/dummynet/ip_dummynet.h>
125 #include <netinet6/ipsec.h>
126 #include <netproto/key/key.h>
130 #include <netproto/ipsec/ipsec.h>
131 #include <netproto/ipsec/key.h>
135 static int ip_rsvp_on
;
136 struct socket
*ip_rsvpd
;
138 int ipforwarding
= 0;
139 SYSCTL_INT(_net_inet_ip
, IPCTL_FORWARDING
, forwarding
, CTLFLAG_RW
,
140 &ipforwarding
, 0, "Enable IP forwarding between interfaces");
142 static int ipsendredirects
= 1; /* XXX */
143 SYSCTL_INT(_net_inet_ip
, IPCTL_SENDREDIRECTS
, redirect
, CTLFLAG_RW
,
144 &ipsendredirects
, 0, "Enable sending IP redirects");
146 int ip_defttl
= IPDEFTTL
;
147 SYSCTL_INT(_net_inet_ip
, IPCTL_DEFTTL
, ttl
, CTLFLAG_RW
,
148 &ip_defttl
, 0, "Maximum TTL on IP packets");
150 static int ip_dosourceroute
= 0;
151 SYSCTL_INT(_net_inet_ip
, IPCTL_SOURCEROUTE
, sourceroute
, CTLFLAG_RW
,
152 &ip_dosourceroute
, 0, "Enable forwarding source routed IP packets");
154 static int ip_acceptsourceroute
= 0;
155 SYSCTL_INT(_net_inet_ip
, IPCTL_ACCEPTSOURCEROUTE
, accept_sourceroute
,
156 CTLFLAG_RW
, &ip_acceptsourceroute
, 0,
157 "Enable accepting source routed IP packets");
159 static int ip_keepfaith
= 0;
160 SYSCTL_INT(_net_inet_ip
, IPCTL_KEEPFAITH
, keepfaith
, CTLFLAG_RW
,
162 "Enable packet capture for FAITH IPv4->IPv6 translator daemon");
164 static int nipq
= 0; /* total # of reass queues */
166 SYSCTL_INT(_net_inet_ip
, OID_AUTO
, maxfragpackets
, CTLFLAG_RW
,
168 "Maximum number of IPv4 fragment reassembly queue entries");
170 static int maxfragsperpacket
;
171 SYSCTL_INT(_net_inet_ip
, OID_AUTO
, maxfragsperpacket
, CTLFLAG_RW
,
172 &maxfragsperpacket
, 0,
173 "Maximum number of IPv4 fragments allowed per packet");
175 static int ip_sendsourcequench
= 0;
176 SYSCTL_INT(_net_inet_ip
, OID_AUTO
, sendsourcequench
, CTLFLAG_RW
,
177 &ip_sendsourcequench
, 0,
178 "Enable the transmission of source quench packets");
180 int ip_do_randomid
= 1;
181 SYSCTL_INT(_net_inet_ip
, OID_AUTO
, random_id
, CTLFLAG_RW
,
183 "Assign random ip_id values");
185 * XXX - Setting ip_checkinterface mostly implements the receive side of
186 * the Strong ES model described in RFC 1122, but since the routing table
187 * and transmit implementation do not implement the Strong ES model,
188 * setting this to 1 results in an odd hybrid.
190 * XXX - ip_checkinterface currently must be disabled if you use ipnat
191 * to translate the destination address to another local interface.
193 * XXX - ip_checkinterface must be disabled if you add IP aliases
194 * to the loopback interface instead of the interface where the
195 * packets for those addresses are received.
197 static int ip_checkinterface
= 0;
198 SYSCTL_INT(_net_inet_ip
, OID_AUTO
, check_interface
, CTLFLAG_RW
,
199 &ip_checkinterface
, 0, "Verify packet arrives on correct interface");
202 static int ipprintfs
= 0;
205 extern struct domain inetdomain
;
206 extern struct protosw inetsw
[];
207 u_char ip_protox
[IPPROTO_MAX
];
208 struct in_ifaddrhead in_ifaddrheads
[MAXCPU
]; /* first inet address */
209 struct in_ifaddrhashhead
*in_ifaddrhashtbls
[MAXCPU
];
210 /* inet addr hash table */
211 u_long in_ifaddrhmask
; /* mask for hash table */
213 struct ip_stats ipstats_percpu
[MAXCPU
];
216 sysctl_ipstats(SYSCTL_HANDLER_ARGS
)
220 for (cpu
= 0; cpu
< ncpus
; ++cpu
) {
221 if ((error
= SYSCTL_OUT(req
, &ipstats_percpu
[cpu
],
222 sizeof(struct ip_stats
))))
224 if ((error
= SYSCTL_IN(req
, &ipstats_percpu
[cpu
],
225 sizeof(struct ip_stats
))))
231 SYSCTL_PROC(_net_inet_ip
, IPCTL_STATS
, stats
, (CTLTYPE_OPAQUE
| CTLFLAG_RW
),
232 0, 0, sysctl_ipstats
, "S,ip_stats", "IP statistics");
234 SYSCTL_STRUCT(_net_inet_ip
, IPCTL_STATS
, stats
, CTLFLAG_RW
,
235 &ipstat
, ip_stats
, "IP statistics");
238 /* Packet reassembly stuff */
239 #define IPREASS_NHASH_LOG2 6
240 #define IPREASS_NHASH (1 << IPREASS_NHASH_LOG2)
241 #define IPREASS_HMASK (IPREASS_NHASH - 1)
242 #define IPREASS_HASH(x,y) \
243 (((((x) & 0xF) | ((((x) >> 8) & 0xF) << 4)) ^ (y)) & IPREASS_HMASK)
245 static struct ipq ipq
[IPREASS_NHASH
];
248 SYSCTL_INT(_net_inet_ip
, IPCTL_DEFMTU
, mtu
, CTLFLAG_RW
,
249 &ip_mtu
, 0, "Default MTU");
253 static int ipstealth
= 0;
254 SYSCTL_INT(_net_inet_ip
, OID_AUTO
, stealth
, CTLFLAG_RW
, &ipstealth
, 0, "");
256 static const int ipstealth
= 0;
261 ip_fw_chk_t
*ip_fw_chk_ptr
;
262 ip_fw_dn_io_t
*ip_fw_dn_io_ptr
;
267 struct pfil_head inet_pfil_hook
;
270 * XXX this is ugly -- the following two global variables are
271 * used to store packet state while it travels through the stack.
272 * Note that the code even makes assumptions on the size and
273 * alignment of fields inside struct ip_srcrt so e.g. adding some
274 * fields will break the code. This needs to be fixed.
276 * We need to save the IP options in case a protocol wants to respond
277 * to an incoming packet over the same route if the packet got here
278 * using IP source routing. This allows connection establishment and
279 * maintenance when the remote end is on a network that is not known
282 static int ip_nhops
= 0;
284 static struct ip_srcrt
{
285 struct in_addr dst
; /* final destination */
286 char nop
; /* one NOP to align */
287 char srcopt
[IPOPT_OFFSET
+ 1]; /* OPTVAL, OLEN and OFFSET */
288 struct in_addr route
[MAX_IPOPTLEN
/sizeof(struct in_addr
)];
291 static MALLOC_DEFINE(M_IPQ
, "ipq", "IP Fragment Management");
292 static struct malloc_pipe ipq_mpipe
;
294 static void save_rte(u_char
*, struct in_addr
);
295 static int ip_dooptions(struct mbuf
*m
, int, struct sockaddr_in
*);
296 static void ip_freef(struct ipq
*);
297 static void ip_input_handler(struct netmsg
*);
298 static struct mbuf
*ip_reass(struct mbuf
*, struct ipq
*, struct ipq
*,
302 * IP initialization: fill in IP protocol switch table.
303 * All protocols not implemented in kernel go to raw IP protocol handler.
315 * Make sure we can handle a reasonable number of fragments but
316 * cap it at 4000 (XXX).
318 mpipe_init(&ipq_mpipe
, M_IPQ
, sizeof(struct ipq
),
319 IFQ_MAXLEN
, 4000, 0, NULL
);
320 for (i
= 0; i
< ncpus
; ++i
) {
321 TAILQ_INIT(&in_ifaddrheads
[i
]);
322 in_ifaddrhashtbls
[i
] =
323 hashinit(INADDR_NHASH
, M_IFADDR
, &in_ifaddrhmask
);
325 pr
= pffindproto(PF_INET
, IPPROTO_RAW
, SOCK_RAW
);
328 for (i
= 0; i
< IPPROTO_MAX
; i
++)
329 ip_protox
[i
] = pr
- inetsw
;
330 for (pr
= inetdomain
.dom_protosw
;
331 pr
< inetdomain
.dom_protoswNPROTOSW
; pr
++)
332 if (pr
->pr_domain
->dom_family
== PF_INET
&&
333 pr
->pr_protocol
&& pr
->pr_protocol
!= IPPROTO_RAW
)
334 ip_protox
[pr
->pr_protocol
] = pr
- inetsw
;
336 inet_pfil_hook
.ph_type
= PFIL_TYPE_AF
;
337 inet_pfil_hook
.ph_af
= AF_INET
;
338 if ((i
= pfil_head_register(&inet_pfil_hook
)) != 0) {
339 kprintf("%s: WARNING: unable to register pfil hook, "
340 "error %d\n", __func__
, i
);
343 for (i
= 0; i
< IPREASS_NHASH
; i
++)
344 ipq
[i
].next
= ipq
[i
].prev
= &ipq
[i
];
346 maxnipq
= nmbclusters
/ 32;
347 maxfragsperpacket
= 16;
349 ip_id
= time_second
& 0xffff;
352 * Initialize IP statistics counters for each CPU.
356 for (cpu
= 0; cpu
< ncpus
; ++cpu
) {
357 bzero(&ipstats_percpu
[cpu
], sizeof(struct ip_stats
));
360 bzero(&ipstat
, sizeof(struct ip_stats
));
363 netisr_register(NETISR_IP
, ip_mport_in
, ip_input_handler
);
367 * XXX watch out this one. It is perhaps used as a cache for
368 * the most recently used route ? it is cleared in in_addroute()
369 * when a new route is successfully created.
371 struct route ipforward_rt
[MAXCPU
];
373 /* Do transport protocol processing. */
375 transport_processing_oncpu(struct mbuf
*m
, int hlen
, struct ip
*ip
)
378 * Switch out to protocol's input routine.
380 (*inetsw
[ip_protox
[ip
->ip_p
]].pr_input
)(m
, hlen
, ip
->ip_p
);
384 transport_processing_handler(netmsg_t netmsg
)
386 struct netmsg_packet
*pmsg
= (struct netmsg_packet
*)netmsg
;
390 ip
= mtod(pmsg
->nm_packet
, struct ip
*);
391 hlen
= pmsg
->nm_netmsg
.nm_lmsg
.u
.ms_result
;
393 transport_processing_oncpu(pmsg
->nm_packet
, hlen
, ip
);
394 /* netmsg was embedded in the mbuf, do not reply! */
398 ip_input_handler(struct netmsg
*msg0
)
400 struct mbuf
*m
= ((struct netmsg_packet
*)msg0
)->nm_packet
;
403 /* msg0 was embedded in the mbuf, do not reply! */
407 * IP input routine. Checksum and byte swap header. If fragmented
408 * try to reassemble. Process options. Pass to next level.
411 ip_input(struct mbuf
*m
)
415 struct in_ifaddr
*ia
= NULL
;
416 struct in_ifaddr_container
*iac
;
417 int i
, hlen
, checkif
;
419 struct in_addr pkt_dst
;
420 u_int32_t divert_info
= 0; /* packet divert/tee info */
421 struct ip_fw_args args
;
422 boolean_t using_srcrt
= FALSE
; /* forward (by PFIL_HOOKS) */
423 boolean_t needredispatch
= FALSE
;
424 struct in_addr odst
; /* original dst address(NAT) */
426 struct sockaddr_in
*next_hop
= NULL
;
428 struct tdb_ident
*tdbi
;
429 struct secpolicy
*sp
;
439 if (m
->m_pkthdr
.fw_flags
& IPFORWARD_MBUF_TAGGED
) {
441 mtag
= m_tag_find(m
, PACKET_TAG_IPFORWARD
, NULL
);
442 KKASSERT(mtag
!= NULL
);
443 next_hop
= m_tag_data(mtag
);
446 /* Extract info from dummynet tag */
447 mtag
= m_tag_find(m
, PACKET_TAG_DUMMYNET
, NULL
);
449 args
.rule
= ((struct dn_pkt
*)m_tag_data(mtag
))->dn_priv
;
450 m_tag_delete(m
, mtag
);
453 if (args
.rule
!= NULL
) { /* dummynet already filtered us */
454 ip
= mtod(m
, struct ip
*);
455 hlen
= IP_VHL_HL(ip
->ip_vhl
) << 2;
461 /* length checks already done in ip_demux() */
462 KASSERT(m
->m_len
>= sizeof(ip
), ("IP header not in one mbuf"));
464 ip
= mtod(m
, struct ip
*);
466 if (IP_VHL_V(ip
->ip_vhl
) != IPVERSION
) {
467 ipstat
.ips_badvers
++;
471 hlen
= IP_VHL_HL(ip
->ip_vhl
) << 2;
472 /* length checks already done in ip_demux() */
473 KASSERT(hlen
>= sizeof(struct ip
), ("IP header len too small"));
474 KASSERT(m
->m_len
>= hlen
, ("packet shorter than IP header length"));
476 /* 127/8 must not appear on wire - RFC1122 */
477 if ((ntohl(ip
->ip_dst
.s_addr
) >> IN_CLASSA_NSHIFT
) == IN_LOOPBACKNET
||
478 (ntohl(ip
->ip_src
.s_addr
) >> IN_CLASSA_NSHIFT
) == IN_LOOPBACKNET
) {
479 if (!(m
->m_pkthdr
.rcvif
->if_flags
& IFF_LOOPBACK
)) {
480 ipstat
.ips_badaddr
++;
485 if (m
->m_pkthdr
.csum_flags
& CSUM_IP_CHECKED
) {
486 sum
= !(m
->m_pkthdr
.csum_flags
& CSUM_IP_VALID
);
488 if (hlen
== sizeof(struct ip
)) {
489 sum
= in_cksum_hdr(ip
);
491 sum
= in_cksum(m
, hlen
);
500 if (altq_input
!= NULL
&& (*altq_input
)(m
, AF_INET
) == 0) {
501 /* packet is dropped by traffic conditioner */
506 * Convert fields to host representation.
508 ip
->ip_len
= ntohs(ip
->ip_len
);
509 if (ip
->ip_len
< hlen
) {
513 ip
->ip_off
= ntohs(ip
->ip_off
);
516 * Check that the amount of data in the buffers
517 * is as at least much as the IP header would have us expect.
518 * Trim mbufs if longer than we expect.
519 * Drop packet if shorter than we expect.
521 if (m
->m_pkthdr
.len
< ip
->ip_len
) {
522 ipstat
.ips_tooshort
++;
525 if (m
->m_pkthdr
.len
> ip
->ip_len
) {
526 if (m
->m_len
== m
->m_pkthdr
.len
) {
527 m
->m_len
= ip
->ip_len
;
528 m
->m_pkthdr
.len
= ip
->ip_len
;
530 m_adj(m
, ip
->ip_len
- m
->m_pkthdr
.len
);
532 #if defined(IPSEC) && !defined(IPSEC_FILTERGIF)
534 * Bypass packet filtering for packets from a tunnel (gif).
536 if (ipsec_gethist(m
, NULL
))
542 * Right now when no processing on packet has done
543 * and it is still fresh out of network we do our black
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.>
555 * Run through list of hooks for input packets.
557 * NB: Beware of the destination address changing (e.g.
558 * by NAT rewriting). When this happens, tell
559 * ip_forward to do the right thing.
561 if (pfil_has_hooks(&inet_pfil_hook
)) {
563 if (pfil_run_hooks(&inet_pfil_hook
, &m
,
564 m
->m_pkthdr
.rcvif
, PFIL_IN
)) {
567 if (m
== NULL
) /* consumed by filter */
569 ip
= mtod(m
, struct ip
*);
570 using_srcrt
= (odst
.s_addr
!= ip
->ip_dst
.s_addr
);
573 if (fw_enable
&& IPFW_LOADED
) {
575 * If we've been forwarded from the output side, then
576 * skip the firewall a second time
578 if (next_hop
!= NULL
)
582 i
= ip_fw_chk_ptr(&args
);
585 if ((i
& IP_FW_PORT_DENY_FLAG
) || m
== NULL
) { /* drop */
590 ip
= mtod(m
, struct ip
*); /* just in case m changed */
592 if (m
->m_pkthdr
.fw_flags
& IPFORWARD_MBUF_TAGGED
) {
593 mtag
= m_tag_find(m
, PACKET_TAG_IPFORWARD
, NULL
);
594 KKASSERT(mtag
!= NULL
);
595 next_hop
= m_tag_data(mtag
);
598 if (i
== 0 && next_hop
== NULL
) /* common case */
600 if (i
& IP_FW_PORT_DYNT_FLAG
) {
601 /* Send packet to the appropriate pipe */
602 ip_fw_dn_io_ptr(m
, i
&0xffff, DN_TO_IP_IN
, &args
);
606 if (i
!= 0 && !(i
& IP_FW_PORT_DYNT_FLAG
)) {
607 /* Divert or tee packet */
612 if (i
== 0 && next_hop
!= NULL
)
615 * if we get here, the packet must be dropped
623 * Process options and, if not destined for us,
624 * ship it on. ip_dooptions returns 1 when an
625 * error was detected (causing an icmp message
626 * to be sent and the original packet to be freed).
628 ip_nhops
= 0; /* for source routed packets */
629 if (hlen
> sizeof(struct ip
) && ip_dooptions(m
, 0, next_hop
))
632 /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
633 * matter if it is destined to another node, or whether it is
634 * a multicast one, RSVP wants it! and prevents it from being forwarded
635 * anywhere else. Also checks if the rsvp daemon is running before
636 * grabbing the packet.
638 if (rsvp_on
&& ip
->ip_p
== IPPROTO_RSVP
)
642 * Check our list of addresses, to see if the packet is for us.
643 * If we don't have any addresses, assume any unicast packet
644 * we receive might be for us (and let the upper layers deal
647 if (TAILQ_EMPTY(&in_ifaddrheads
[mycpuid
]) &&
648 !(m
->m_flags
& (M_MCAST
| M_BCAST
)))
652 * Cache the destination address of the packet; this may be
653 * changed by use of 'ipfw fwd'.
655 pkt_dst
= next_hop
? next_hop
->sin_addr
: ip
->ip_dst
;
658 * Enable a consistency check between the destination address
659 * and the arrival interface for a unicast packet (the RFC 1122
660 * strong ES model) if IP forwarding is disabled and the packet
661 * is not locally generated and the packet is not subject to
664 * XXX - Checking also should be disabled if the destination
665 * address is ipnat'ed to a different interface.
667 * XXX - Checking is incompatible with IP aliases added
668 * to the loopback interface instead of the interface where
669 * the packets are received.
671 checkif
= ip_checkinterface
&&
673 m
->m_pkthdr
.rcvif
!= NULL
&&
674 !(m
->m_pkthdr
.rcvif
->if_flags
& IFF_LOOPBACK
) &&
678 * Check for exact addresses in the hash bucket.
680 LIST_FOREACH(iac
, INADDR_HASH(pkt_dst
.s_addr
), ia_hash
) {
684 * If the address matches, verify that the packet
685 * arrived via the correct interface if checking is
688 if (IA_SIN(ia
)->sin_addr
.s_addr
== pkt_dst
.s_addr
&&
689 (!checkif
|| ia
->ia_ifp
== m
->m_pkthdr
.rcvif
))
695 * Check for broadcast addresses.
697 * Only accept broadcast packets that arrive via the matching
698 * interface. Reception of forwarded directed broadcasts would
699 * be handled via ip_forward() and ether_output() with the loopback
700 * into the stack for SIMPLEX interfaces handled by ether_output().
702 if (m
->m_pkthdr
.rcvif
->if_flags
& IFF_BROADCAST
) {
703 struct ifaddr_container
*ifac
;
705 TAILQ_FOREACH(ifac
, &m
->m_pkthdr
.rcvif
->if_addrheads
[mycpuid
],
707 struct ifaddr
*ifa
= ifac
->ifa
;
709 if (ifa
->ifa_addr
== NULL
) /* shutdown/startup race */
711 if (ifa
->ifa_addr
->sa_family
!= AF_INET
)
714 if (satosin(&ia
->ia_broadaddr
)->sin_addr
.s_addr
==
717 if (ia
->ia_netbroadcast
.s_addr
== pkt_dst
.s_addr
)
720 if (IA_SIN(ia
)->sin_addr
.s_addr
== INADDR_ANY
)
725 if (IN_MULTICAST(ntohl(ip
->ip_dst
.s_addr
))) {
726 struct in_multi
*inm
;
728 if (ip_mrouter
!= NULL
) {
730 * If we are acting as a multicast router, all
731 * incoming multicast packets are passed to the
732 * kernel-level multicast forwarding function.
733 * The packet is returned (relatively) intact; if
734 * ip_mforward() returns a non-zero value, the packet
735 * must be discarded, else it may be accepted below.
737 if (ip_mforward
!= NULL
&&
738 ip_mforward(ip
, m
->m_pkthdr
.rcvif
, m
, NULL
) != 0) {
739 ipstat
.ips_cantforward
++;
745 * The process-level routing daemon needs to receive
746 * all multicast IGMP packets, whether or not this
747 * host belongs to their destination groups.
749 if (ip
->ip_p
== IPPROTO_IGMP
)
751 ipstat
.ips_forward
++;
754 * See if we belong to the destination multicast group on the
757 IN_LOOKUP_MULTI(ip
->ip_dst
, m
->m_pkthdr
.rcvif
, inm
);
759 ipstat
.ips_notmember
++;
765 if (ip
->ip_dst
.s_addr
== INADDR_BROADCAST
)
767 if (ip
->ip_dst
.s_addr
== INADDR_ANY
)
771 * FAITH(Firewall Aided Internet Translator)
773 if (m
->m_pkthdr
.rcvif
&& m
->m_pkthdr
.rcvif
->if_type
== IFT_FAITH
) {
775 if (ip
->ip_p
== IPPROTO_TCP
|| ip
->ip_p
== IPPROTO_ICMP
)
783 * Not for us; forward if possible and desirable.
786 ipstat
.ips_cantforward
++;
791 * Enforce inbound IPsec SPD.
793 if (ipsec4_in_reject(m
, NULL
)) {
794 ipsecstat
.in_polvio
++;
799 mtag
= m_tag_find(m
, PACKET_TAG_IPSEC_IN_DONE
, NULL
);
802 tdbi
= (struct tdb_ident
*)m_tag_data(mtag
);
803 sp
= ipsec_getpolicy(tdbi
, IPSEC_DIR_INBOUND
);
805 sp
= ipsec_getpolicybyaddr(m
, IPSEC_DIR_INBOUND
,
806 IP_FORWARDING
, &error
);
808 if (sp
== NULL
) { /* NB: can happen if error */
810 /*XXX error stat???*/
811 DPRINTF(("ip_input: no SP for forwarding\n")); /*XXX*/
816 * Check security policy against packet attributes.
818 error
= ipsec_in_reject(sp
, m
);
822 ipstat
.ips_cantforward
++;
826 ip_forward(m
, using_srcrt
, next_hop
);
833 * IPSTEALTH: Process non-routing options only
834 * if the packet is destined for us.
837 hlen
> sizeof(struct ip
) &&
838 ip_dooptions(m
, 1, next_hop
))
841 /* Count the packet in the ip address stats */
843 ia
->ia_ifa
.if_ipackets
++;
844 ia
->ia_ifa
.if_ibytes
+= m
->m_pkthdr
.len
;
848 * If offset or IP_MF are set, must reassemble.
849 * Otherwise, nothing need be done.
850 * (We could look in the reassembly queue to see
851 * if the packet was previously fragmented,
852 * but it's not worth the time; just let them time out.)
854 if (ip
->ip_off
& (IP_MF
| IP_OFFMASK
)) {
856 /* If maxnipq is 0, never accept fragments. */
858 ipstat
.ips_fragments
++;
859 ipstat
.ips_fragdropped
++;
863 sum
= IPREASS_HASH(ip
->ip_src
.s_addr
, ip
->ip_id
);
865 * Look for queue of fragments
868 for (fp
= ipq
[sum
].next
; fp
!= &ipq
[sum
]; fp
= fp
->next
)
869 if (ip
->ip_id
== fp
->ipq_id
&&
870 ip
->ip_src
.s_addr
== fp
->ipq_src
.s_addr
&&
871 ip
->ip_dst
.s_addr
== fp
->ipq_dst
.s_addr
&&
872 ip
->ip_p
== fp
->ipq_p
)
878 * Enforce upper bound on number of fragmented packets
879 * for which we attempt reassembly;
880 * If maxnipq is -1, accept all fragments without limitation.
882 if ((nipq
> maxnipq
) && (maxnipq
> 0)) {
884 * drop something from the tail of the current queue
885 * before proceeding further
887 if (ipq
[sum
].prev
== &ipq
[sum
]) { /* gak */
888 for (i
= 0; i
< IPREASS_NHASH
; i
++) {
889 if (ipq
[i
].prev
!= &ipq
[i
]) {
890 ipstat
.ips_fragtimeout
+=
891 ipq
[i
].prev
->ipq_nfrags
;
892 ip_freef(ipq
[i
].prev
);
897 ipstat
.ips_fragtimeout
+=
898 ipq
[sum
].prev
->ipq_nfrags
;
899 ip_freef(ipq
[sum
].prev
);
904 * Adjust ip_len to not reflect header,
905 * convert offset of this to bytes.
908 if (ip
->ip_off
& IP_MF
) {
910 * Make sure that fragments have a data length
911 * that's a non-zero multiple of 8 bytes.
913 if (ip
->ip_len
== 0 || (ip
->ip_len
& 0x7) != 0) {
914 ipstat
.ips_toosmall
++; /* XXX */
917 m
->m_flags
|= M_FRAG
;
919 m
->m_flags
&= ~M_FRAG
;
923 * Attempt reassembly; if it succeeds, proceed.
924 * ip_reass() will return a different mbuf, and update
925 * the divert info in divert_info.
927 ipstat
.ips_fragments
++;
928 m
->m_pkthdr
.header
= ip
;
929 m
= ip_reass(m
, fp
, &ipq
[sum
], &divert_info
);
933 needredispatch
= TRUE
;
934 ip
= mtod(m
, struct ip
*);
935 /* Get the header length of the reassembled packet */
936 hlen
= IP_VHL_HL(ip
->ip_vhl
) << 2;
938 /* Restore original checksum before diverting packet */
939 if (divert_info
!= 0) {
941 ip
->ip_len
= htons(ip
->ip_len
);
942 ip
->ip_off
= htons(ip
->ip_off
);
944 if (hlen
== sizeof(struct ip
))
945 ip
->ip_sum
= in_cksum_hdr(ip
);
947 ip
->ip_sum
= in_cksum(m
, hlen
);
948 ip
->ip_off
= ntohs(ip
->ip_off
);
949 ip
->ip_len
= ntohs(ip
->ip_len
);
959 * Divert or tee packet to the divert protocol if required.
961 if (divert_info
!= 0) {
962 struct mbuf
*clone
= NULL
;
964 /* Clone packet if we're doing a 'tee' */
965 if ((divert_info
& IP_FW_PORT_TEE_FLAG
) != 0)
966 clone
= m_dup(m
, MB_DONTWAIT
);
968 /* Restore packet header fields to original values */
970 ip
->ip_len
= htons(ip
->ip_len
);
971 ip
->ip_off
= htons(ip
->ip_off
);
973 /* Deliver packet to divert input routine */
974 divert_packet(m
, 1, divert_info
& 0xffff);
975 ipstat
.ips_delivered
++;
977 /* If 'tee', continue with original packet */
981 ip
= mtod(m
, struct ip
*);
984 * Jump backwards to complete processing of the
985 * packet. But first clear divert_info to avoid
986 * entering this block again.
987 * We do not need to clear args.divert_rule as
988 * it will not be used.
990 * XXX Better safe than sorry, remove the DIVERT tag.
992 mtag
= m_tag_find(m
, PACKET_TAG_IPFW_DIVERT
, NULL
);
994 m_tag_delete(m
, mtag
);
1003 * enforce IPsec policy checking if we are seeing last header.
1004 * note that we do not visit this with protocols with pcb layer
1005 * code - like udp/tcp/raw ip.
1007 if ((inetsw
[ip_protox
[ip
->ip_p
]].pr_flags
& PR_LASTHDR
) &&
1008 ipsec4_in_reject(m
, NULL
)) {
1009 ipsecstat
.in_polvio
++;
1015 * enforce IPsec policy checking if we are seeing last header.
1016 * note that we do not visit this with protocols with pcb layer
1017 * code - like udp/tcp/raw ip.
1019 if (inetsw
[ip_protox
[ip
->ip_p
]].pr_flags
& PR_LASTHDR
) {
1021 * Check if the packet has already had IPsec processing
1022 * done. If so, then just pass it along. This tag gets
1023 * set during AH, ESP, etc. input handling, before the
1024 * packet is returned to the ip input queue for delivery.
1026 mtag
= m_tag_find(m
, PACKET_TAG_IPSEC_IN_DONE
, NULL
);
1029 tdbi
= (struct tdb_ident
*)m_tag_data(mtag
);
1030 sp
= ipsec_getpolicy(tdbi
, IPSEC_DIR_INBOUND
);
1032 sp
= ipsec_getpolicybyaddr(m
, IPSEC_DIR_INBOUND
,
1033 IP_FORWARDING
, &error
);
1037 * Check security policy against packet attributes.
1039 error
= ipsec_in_reject(sp
, m
);
1042 /* XXX error stat??? */
1044 DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/
1051 #endif /* FAST_IPSEC */
1053 ipstat
.ips_delivered
++;
1054 if (needredispatch
) {
1055 struct netmsg_packet
*pmsg
;
1058 ip
->ip_off
= htons(ip
->ip_off
);
1059 ip
->ip_len
= htons(ip
->ip_len
);
1060 port
= ip_mport_in(&m
);
1064 pmsg
= &m
->m_hdr
.mh_netmsg
;
1065 netmsg_init(&pmsg
->nm_netmsg
, &netisr_apanic_rport
, 0,
1066 transport_processing_handler
);
1067 pmsg
->nm_packet
= m
;
1068 pmsg
->nm_netmsg
.nm_lmsg
.u
.ms_result
= hlen
;
1070 ip
= mtod(m
, struct ip
*);
1071 ip
->ip_len
= ntohs(ip
->ip_len
);
1072 ip
->ip_off
= ntohs(ip
->ip_off
);
1073 lwkt_sendmsg(port
, &pmsg
->nm_netmsg
.nm_lmsg
);
1075 transport_processing_oncpu(m
, hlen
, ip
);
1084 * Take incoming datagram fragment and try to reassemble it into
1085 * whole datagram. If a chain for reassembly of this datagram already
1086 * exists, then it is given as fp; otherwise have to make a chain.
1088 * When IPDIVERT enabled, keep additional state with each packet that
1089 * tells us if we need to divert or tee the packet we're building.
1090 * In particular, *divinfo includes the port and TEE flag.
1093 static struct mbuf
*
1094 ip_reass(struct mbuf
*m
, struct ipq
*fp
, struct ipq
*where
,
1097 struct ip
*ip
= mtod(m
, struct ip
*);
1098 struct mbuf
*p
= NULL
, *q
, *nq
;
1100 int hlen
= IP_VHL_HL(ip
->ip_vhl
) << 2;
1107 * If the hardware has not done csum over this fragment
1108 * then csum_data is not valid at all.
1110 if ((m
->m_pkthdr
.csum_flags
& (CSUM_FRAG_NOT_CHECKED
| CSUM_DATA_VALID
))
1111 == (CSUM_FRAG_NOT_CHECKED
| CSUM_DATA_VALID
)) {
1112 m
->m_pkthdr
.csum_data
= 0;
1113 m
->m_pkthdr
.csum_flags
&= ~(CSUM_DATA_VALID
| CSUM_PSEUDO_HDR
);
1117 * Presence of header sizes in mbufs
1118 * would confuse code below.
1124 * If first fragment to arrive, create a reassembly queue.
1127 if ((fp
= mpipe_alloc_nowait(&ipq_mpipe
)) == NULL
)
1132 fp
->ipq_ttl
= IPFRAGTTL
;
1133 fp
->ipq_p
= ip
->ip_p
;
1134 fp
->ipq_id
= ip
->ip_id
;
1135 fp
->ipq_src
= ip
->ip_src
;
1136 fp
->ipq_dst
= ip
->ip_dst
;
1138 m
->m_nextpkt
= NULL
;
1140 fp
->ipq_div_info
= 0;
1147 #define GETIP(m) ((struct ip*)((m)->m_pkthdr.header))
1150 * Find a segment which begins after this one does.
1152 for (p
= NULL
, q
= fp
->ipq_frags
; q
; p
= q
, q
= q
->m_nextpkt
)
1153 if (GETIP(q
)->ip_off
> ip
->ip_off
)
1157 * If there is a preceding segment, it may provide some of
1158 * our data already. If so, drop the data from the incoming
1159 * segment. If it provides all of our data, drop us, otherwise
1160 * stick new segment in the proper place.
1162 * If some of the data is dropped from the the preceding
1163 * segment, then it's checksum is invalidated.
1166 i
= GETIP(p
)->ip_off
+ GETIP(p
)->ip_len
- ip
->ip_off
;
1168 if (i
>= ip
->ip_len
)
1171 m
->m_pkthdr
.csum_flags
= 0;
1175 m
->m_nextpkt
= p
->m_nextpkt
;
1178 m
->m_nextpkt
= fp
->ipq_frags
;
1183 * While we overlap succeeding segments trim them or,
1184 * if they are completely covered, dequeue them.
1186 for (; q
!= NULL
&& ip
->ip_off
+ ip
->ip_len
> GETIP(q
)->ip_off
;
1188 i
= (ip
->ip_off
+ ip
->ip_len
) - GETIP(q
)->ip_off
;
1189 if (i
< GETIP(q
)->ip_len
) {
1190 GETIP(q
)->ip_len
-= i
;
1191 GETIP(q
)->ip_off
+= i
;
1193 q
->m_pkthdr
.csum_flags
= 0;
1198 ipstat
.ips_fragdropped
++;
1200 q
->m_nextpkt
= NULL
;
1208 * Transfer firewall instructions to the fragment structure.
1209 * Only trust info in the fragment at offset 0.
1211 if (ip
->ip_off
== 0) {
1212 fp
->ipq_div_info
= *divinfo
;
1214 mtag
= m_tag_find(m
, PACKET_TAG_IPFW_DIVERT
, NULL
);
1216 m_tag_delete(m
, mtag
);
1222 * Check for complete reassembly and perform frag per packet
1225 * Frag limiting is performed here so that the nth frag has
1226 * a chance to complete the packet before we drop the packet.
1227 * As a result, n+1 frags are actually allowed per packet, but
1228 * only n will ever be stored. (n = maxfragsperpacket.)
1232 for (p
= NULL
, q
= fp
->ipq_frags
; q
; p
= q
, q
= q
->m_nextpkt
) {
1233 if (GETIP(q
)->ip_off
!= next
) {
1234 if (fp
->ipq_nfrags
> maxfragsperpacket
) {
1235 ipstat
.ips_fragdropped
+= fp
->ipq_nfrags
;
1240 next
+= GETIP(q
)->ip_len
;
1242 /* Make sure the last packet didn't have the IP_MF flag */
1243 if (p
->m_flags
& M_FRAG
) {
1244 if (fp
->ipq_nfrags
> maxfragsperpacket
) {
1245 ipstat
.ips_fragdropped
+= fp
->ipq_nfrags
;
1252 * Reassembly is complete. Make sure the packet is a sane size.
1256 if (next
+ (IP_VHL_HL(ip
->ip_vhl
) << 2) > IP_MAXPACKET
) {
1257 ipstat
.ips_toolong
++;
1258 ipstat
.ips_fragdropped
+= fp
->ipq_nfrags
;
1264 * Concatenate fragments.
1271 q
->m_nextpkt
= NULL
;
1272 for (q
= nq
; q
!= NULL
; q
= nq
) {
1274 q
->m_nextpkt
= NULL
;
1275 m
->m_pkthdr
.csum_flags
&= q
->m_pkthdr
.csum_flags
;
1276 m
->m_pkthdr
.csum_data
+= q
->m_pkthdr
.csum_data
;
1281 * Clean up the 1's complement checksum. Carry over 16 bits must
1282 * be added back. This assumes no more then 65535 packet fragments
1283 * were reassembled. A second carry can also occur (but not a third).
1285 m
->m_pkthdr
.csum_data
= (m
->m_pkthdr
.csum_data
& 0xffff) +
1286 (m
->m_pkthdr
.csum_data
>> 16);
1287 if (m
->m_pkthdr
.csum_data
> 0xFFFF)
1288 m
->m_pkthdr
.csum_data
-= 0xFFFF;
1293 * Extract firewall instructions from the fragment structure.
1295 *divinfo
= fp
->ipq_div_info
;
1299 * Create header for new ip packet by
1300 * modifying header of first packet;
1301 * dequeue and discard fragment reassembly header.
1302 * Make header visible.
1305 ip
->ip_src
= fp
->ipq_src
;
1306 ip
->ip_dst
= fp
->ipq_dst
;
1309 mpipe_free(&ipq_mpipe
, fp
);
1310 m
->m_len
+= (IP_VHL_HL(ip
->ip_vhl
) << 2);
1311 m
->m_data
-= (IP_VHL_HL(ip
->ip_vhl
) << 2);
1312 /* some debugging cruft by sklower, below, will go away soon */
1313 if (m
->m_flags
& M_PKTHDR
) { /* XXX this should be done elsewhere */
1316 for (n
= m
; n
; n
= n
->m_next
)
1318 m
->m_pkthdr
.len
= plen
;
1321 ipstat
.ips_reassembled
++;
1328 ipstat
.ips_fragdropped
++;
1338 * Free a fragment reassembly header and all
1339 * associated datagrams.
1342 ip_freef(struct ipq
*fp
)
1346 while (fp
->ipq_frags
) {
1348 fp
->ipq_frags
= q
->m_nextpkt
;
1349 q
->m_nextpkt
= NULL
;
1353 mpipe_free(&ipq_mpipe
, fp
);
1358 * IP timer processing;
1359 * if a timer expires on a reassembly
1360 * queue, discard it.
1369 for (i
= 0; i
< IPREASS_NHASH
; i
++) {
1373 while (fp
!= &ipq
[i
]) {
1376 if (fp
->prev
->ipq_ttl
== 0) {
1377 ipstat
.ips_fragtimeout
+= fp
->prev
->ipq_nfrags
;
1383 * If we are over the maximum number of fragments
1384 * (due to the limit being lowered), drain off
1385 * enough to get down to the new limit.
1387 if (maxnipq
>= 0 && nipq
> maxnipq
) {
1388 for (i
= 0; i
< IPREASS_NHASH
; i
++) {
1389 while (nipq
> maxnipq
&&
1390 (ipq
[i
].next
!= &ipq
[i
])) {
1391 ipstat
.ips_fragdropped
+=
1392 ipq
[i
].next
->ipq_nfrags
;
1393 ip_freef(ipq
[i
].next
);
1402 * Drain off all datagram fragments.
1409 for (i
= 0; i
< IPREASS_NHASH
; i
++) {
1410 while (ipq
[i
].next
!= &ipq
[i
]) {
1411 ipstat
.ips_fragdropped
+= ipq
[i
].next
->ipq_nfrags
;
1412 ip_freef(ipq
[i
].next
);
1419 * Do option processing on a datagram,
1420 * possibly discarding it if bad options are encountered,
1421 * or forwarding it if source-routed.
1422 * The pass argument is used when operating in the IPSTEALTH
1423 * mode to tell what options to process:
1424 * [LS]SRR (pass 0) or the others (pass 1).
1425 * The reason for as many as two passes is that when doing IPSTEALTH,
1426 * non-routing options should be processed only if the packet is for us.
1427 * Returns 1 if packet has been forwarded/freed,
1428 * 0 if the packet should be processed further.
1431 ip_dooptions(struct mbuf
*m
, int pass
, struct sockaddr_in
*next_hop
)
1433 struct sockaddr_in ipaddr
= { sizeof ipaddr
, AF_INET
};
1434 struct ip
*ip
= mtod(m
, struct ip
*);
1436 struct in_ifaddr
*ia
;
1437 int opt
, optlen
, cnt
, off
, code
, type
= ICMP_PARAMPROB
;
1438 boolean_t forward
= FALSE
;
1439 struct in_addr
*sin
, dst
;
1443 cp
= (u_char
*)(ip
+ 1);
1444 cnt
= (IP_VHL_HL(ip
->ip_vhl
) << 2) - sizeof(struct ip
);
1445 for (; cnt
> 0; cnt
-= optlen
, cp
+= optlen
) {
1446 opt
= cp
[IPOPT_OPTVAL
];
1447 if (opt
== IPOPT_EOL
)
1449 if (opt
== IPOPT_NOP
)
1452 if (cnt
< IPOPT_OLEN
+ sizeof(*cp
)) {
1453 code
= &cp
[IPOPT_OLEN
] - (u_char
*)ip
;
1456 optlen
= cp
[IPOPT_OLEN
];
1457 if (optlen
< IPOPT_OLEN
+ sizeof(*cp
) || optlen
> cnt
) {
1458 code
= &cp
[IPOPT_OLEN
] - (u_char
*)ip
;
1468 * Source routing with record.
1469 * Find interface with current destination address.
1470 * If none on this machine then drop if strictly routed,
1471 * or do nothing if loosely routed.
1472 * Record interface address and bring up next address
1473 * component. If strictly routed make sure next
1474 * address is on directly accessible net.
1478 if (ipstealth
&& pass
> 0)
1480 if (optlen
< IPOPT_OFFSET
+ sizeof(*cp
)) {
1481 code
= &cp
[IPOPT_OLEN
] - (u_char
*)ip
;
1484 if ((off
= cp
[IPOPT_OFFSET
]) < IPOPT_MINOFF
) {
1485 code
= &cp
[IPOPT_OFFSET
] - (u_char
*)ip
;
1488 ipaddr
.sin_addr
= ip
->ip_dst
;
1489 ia
= (struct in_ifaddr
*)
1490 ifa_ifwithaddr((struct sockaddr
*)&ipaddr
);
1492 if (opt
== IPOPT_SSRR
) {
1493 type
= ICMP_UNREACH
;
1494 code
= ICMP_UNREACH_SRCFAIL
;
1497 if (!ip_dosourceroute
)
1498 goto nosourcerouting
;
1500 * Loose routing, and not at next destination
1501 * yet; nothing to do except forward.
1505 off
--; /* 0 origin */
1506 if (off
> optlen
- (int)sizeof(struct in_addr
)) {
1508 * End of source route. Should be for us.
1510 if (!ip_acceptsourceroute
)
1511 goto nosourcerouting
;
1512 save_rte(cp
, ip
->ip_src
);
1517 if (!ip_dosourceroute
) {
1519 char buf
[sizeof "aaa.bbb.ccc.ddd"];
1522 * Acting as a router, so generate ICMP
1525 strcpy(buf
, inet_ntoa(ip
->ip_dst
));
1527 "attempted source route from %s to %s\n",
1528 inet_ntoa(ip
->ip_src
), buf
);
1529 type
= ICMP_UNREACH
;
1530 code
= ICMP_UNREACH_SRCFAIL
;
1534 * Not acting as a router,
1538 ipstat
.ips_cantforward
++;
1545 * locate outgoing interface
1547 memcpy(&ipaddr
.sin_addr
, cp
+ off
,
1548 sizeof ipaddr
.sin_addr
);
1550 if (opt
== IPOPT_SSRR
) {
1551 #define INA struct in_ifaddr *
1552 #define SA struct sockaddr *
1553 if ((ia
= (INA
)ifa_ifwithdstaddr((SA
)&ipaddr
))
1555 ia
= (INA
)ifa_ifwithnet((SA
)&ipaddr
);
1557 ia
= ip_rtaddr(ipaddr
.sin_addr
,
1558 &ipforward_rt
[mycpuid
]);
1560 type
= ICMP_UNREACH
;
1561 code
= ICMP_UNREACH_SRCFAIL
;
1564 ip
->ip_dst
= ipaddr
.sin_addr
;
1565 memcpy(cp
+ off
, &IA_SIN(ia
)->sin_addr
,
1566 sizeof(struct in_addr
));
1567 cp
[IPOPT_OFFSET
] += sizeof(struct in_addr
);
1569 * Let ip_intr's mcast routing check handle mcast pkts
1571 forward
= !IN_MULTICAST(ntohl(ip
->ip_dst
.s_addr
));
1575 if (ipstealth
&& pass
== 0)
1577 if (optlen
< IPOPT_OFFSET
+ sizeof(*cp
)) {
1578 code
= &cp
[IPOPT_OFFSET
] - (u_char
*)ip
;
1581 if ((off
= cp
[IPOPT_OFFSET
]) < IPOPT_MINOFF
) {
1582 code
= &cp
[IPOPT_OFFSET
] - (u_char
*)ip
;
1586 * If no space remains, ignore.
1588 off
--; /* 0 origin */
1589 if (off
> optlen
- (int)sizeof(struct in_addr
))
1591 memcpy(&ipaddr
.sin_addr
, &ip
->ip_dst
,
1592 sizeof ipaddr
.sin_addr
);
1594 * locate outgoing interface; if we're the destination,
1595 * use the incoming interface (should be same).
1597 if ((ia
= (INA
)ifa_ifwithaddr((SA
)&ipaddr
)) == NULL
&&
1598 (ia
= ip_rtaddr(ipaddr
.sin_addr
,
1599 &ipforward_rt
[mycpuid
]))
1601 type
= ICMP_UNREACH
;
1602 code
= ICMP_UNREACH_HOST
;
1605 memcpy(cp
+ off
, &IA_SIN(ia
)->sin_addr
,
1606 sizeof(struct in_addr
));
1607 cp
[IPOPT_OFFSET
] += sizeof(struct in_addr
);
1611 if (ipstealth
&& pass
== 0)
1613 code
= cp
- (u_char
*)ip
;
1614 if (optlen
< 4 || optlen
> 40) {
1615 code
= &cp
[IPOPT_OLEN
] - (u_char
*)ip
;
1618 if ((off
= cp
[IPOPT_OFFSET
]) < 5) {
1619 code
= &cp
[IPOPT_OLEN
] - (u_char
*)ip
;
1622 if (off
> optlen
- (int)sizeof(int32_t)) {
1623 cp
[IPOPT_OFFSET
+ 1] += (1 << 4);
1624 if ((cp
[IPOPT_OFFSET
+ 1] & 0xf0) == 0) {
1625 code
= &cp
[IPOPT_OFFSET
] - (u_char
*)ip
;
1630 off
--; /* 0 origin */
1631 sin
= (struct in_addr
*)(cp
+ off
);
1632 switch (cp
[IPOPT_OFFSET
+ 1] & 0x0f) {
1634 case IPOPT_TS_TSONLY
:
1637 case IPOPT_TS_TSANDADDR
:
1638 if (off
+ sizeof(n_time
) +
1639 sizeof(struct in_addr
) > optlen
) {
1640 code
= &cp
[IPOPT_OFFSET
] - (u_char
*)ip
;
1643 ipaddr
.sin_addr
= dst
;
1644 ia
= (INA
)ifaof_ifpforaddr((SA
)&ipaddr
,
1648 memcpy(sin
, &IA_SIN(ia
)->sin_addr
,
1649 sizeof(struct in_addr
));
1650 cp
[IPOPT_OFFSET
] += sizeof(struct in_addr
);
1651 off
+= sizeof(struct in_addr
);
1654 case IPOPT_TS_PRESPEC
:
1655 if (off
+ sizeof(n_time
) +
1656 sizeof(struct in_addr
) > optlen
) {
1657 code
= &cp
[IPOPT_OFFSET
] - (u_char
*)ip
;
1660 memcpy(&ipaddr
.sin_addr
, sin
,
1661 sizeof(struct in_addr
));
1662 if (ifa_ifwithaddr((SA
)&ipaddr
) == NULL
)
1664 cp
[IPOPT_OFFSET
] += sizeof(struct in_addr
);
1665 off
+= sizeof(struct in_addr
);
1669 code
= &cp
[IPOPT_OFFSET
+ 1] - (u_char
*)ip
;
1673 memcpy(cp
+ off
, &ntime
, sizeof(n_time
));
1674 cp
[IPOPT_OFFSET
] += sizeof(n_time
);
1677 if (forward
&& ipforwarding
) {
1678 ip_forward(m
, TRUE
, next_hop
);
1683 icmp_error(m
, type
, code
, 0, 0);
1684 ipstat
.ips_badoptions
++;
1689 * Given address of next destination (final or next hop),
1690 * return internet address info of interface to be used to get there.
1693 ip_rtaddr(struct in_addr dst
, struct route
*ro
)
1695 struct sockaddr_in
*sin
;
1697 sin
= (struct sockaddr_in
*)&ro
->ro_dst
;
1699 if (ro
->ro_rt
== NULL
|| dst
.s_addr
!= sin
->sin_addr
.s_addr
) {
1700 if (ro
->ro_rt
!= NULL
) {
1704 sin
->sin_family
= AF_INET
;
1705 sin
->sin_len
= sizeof *sin
;
1706 sin
->sin_addr
= dst
;
1707 rtalloc_ign(ro
, RTF_PRCLONING
);
1710 if (ro
->ro_rt
== NULL
)
1713 return (ifatoia(ro
->ro_rt
->rt_ifa
));
1717 * Save incoming source route for use in replies,
1718 * to be picked up later by ip_srcroute if the receiver is interested.
1721 save_rte(u_char
*option
, struct in_addr dst
)
1725 olen
= option
[IPOPT_OLEN
];
1728 kprintf("save_rte: olen %d\n", olen
);
1730 if (olen
> sizeof(ip_srcrt
) - (1 + sizeof(dst
)))
1732 bcopy(option
, ip_srcrt
.srcopt
, olen
);
1733 ip_nhops
= (olen
- IPOPT_OFFSET
- 1) / sizeof(struct in_addr
);
1738 * Retrieve incoming source route for use in replies,
1739 * in the same form used by setsockopt.
1740 * The first hop is placed before the options, will be removed later.
1745 struct in_addr
*p
, *q
;
1750 m
= m_get(MB_DONTWAIT
, MT_HEADER
);
1754 #define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1756 /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1757 m
->m_len
= ip_nhops
* sizeof(struct in_addr
) + sizeof(struct in_addr
) +
1761 kprintf("ip_srcroute: nhops %d mlen %d", ip_nhops
, m
->m_len
);
1765 * First save first hop for return route
1767 p
= &ip_srcrt
.route
[ip_nhops
- 1];
1768 *(mtod(m
, struct in_addr
*)) = *p
--;
1771 kprintf(" hops %x", ntohl(mtod(m
, struct in_addr
*)->s_addr
));
1775 * Copy option fields and padding (nop) to mbuf.
1777 ip_srcrt
.nop
= IPOPT_NOP
;
1778 ip_srcrt
.srcopt
[IPOPT_OFFSET
] = IPOPT_MINOFF
;
1779 memcpy(mtod(m
, caddr_t
) + sizeof(struct in_addr
), &ip_srcrt
.nop
,
1781 q
= (struct in_addr
*)(mtod(m
, caddr_t
) +
1782 sizeof(struct in_addr
) + OPTSIZ
);
1785 * Record return path as an IP source route,
1786 * reversing the path (pointers are now aligned).
1788 while (p
>= ip_srcrt
.route
) {
1791 kprintf(" %x", ntohl(q
->s_addr
));
1796 * Last hop goes to final destination.
1801 kprintf(" %x\n", ntohl(q
->s_addr
));
1807 * Strip out IP options.
1810 ip_stripoptions(struct mbuf
*m
)
1813 struct ip
*ip
= mtod(m
, struct ip
*);
1817 optlen
= (IP_VHL_HL(ip
->ip_vhl
) << 2) - sizeof(struct ip
);
1818 opts
= (caddr_t
)(ip
+ 1);
1819 datalen
= m
->m_len
- (sizeof(struct ip
) + optlen
);
1820 bcopy(opts
+ optlen
, opts
, datalen
);
1822 if (m
->m_flags
& M_PKTHDR
)
1823 m
->m_pkthdr
.len
-= optlen
;
1824 ip
->ip_vhl
= IP_MAKE_VHL(IPVERSION
, sizeof(struct ip
) >> 2);
1827 u_char inetctlerrmap
[PRC_NCMDS
] = {
1829 0, EMSGSIZE
, EHOSTDOWN
, EHOSTUNREACH
,
1830 EHOSTUNREACH
, EHOSTUNREACH
, ECONNREFUSED
, ECONNREFUSED
,
1831 EMSGSIZE
, EHOSTUNREACH
, 0, 0,
1833 ENOPROTOOPT
, ECONNREFUSED
1837 * Forward a packet. If some error occurs return the sender
1838 * an icmp packet. Note we can't always generate a meaningful
1839 * icmp message because icmp doesn't have a large enough repertoire
1840 * of codes and types.
1842 * If not forwarding, just drop the packet. This could be confusing
1843 * if ipforwarding was zero but some routing protocol was advancing
1844 * us as a gateway to somewhere. However, we must let the routing
1845 * protocol deal with that.
1847 * The using_srcrt parameter indicates whether the packet is being forwarded
1848 * via a source route.
1851 ip_forward(struct mbuf
*m
, boolean_t using_srcrt
, struct sockaddr_in
*next_hop
)
1853 struct ip
*ip
= mtod(m
, struct ip
*);
1854 struct sockaddr_in
*ipforward_rtaddr
;
1856 int error
, type
= 0, code
= 0, destmtu
= 0;
1859 struct in_addr pkt_dst
;
1860 struct route
*cache_rt
= &ipforward_rt
[mycpuid
];
1864 * Cache the destination address of the packet; this may be
1865 * changed by use of 'ipfw fwd'.
1867 pkt_dst
= (next_hop
!= NULL
) ? next_hop
->sin_addr
: ip
->ip_dst
;
1871 kprintf("forward: src %x dst %x ttl %x\n",
1872 ip
->ip_src
.s_addr
, pkt_dst
.s_addr
, ip
->ip_ttl
);
1875 if (m
->m_flags
& (M_BCAST
| M_MCAST
) || !in_canforward(pkt_dst
)) {
1876 ipstat
.ips_cantforward
++;
1880 if (!ipstealth
&& ip
->ip_ttl
<= IPTTLDEC
) {
1881 icmp_error(m
, ICMP_TIMXCEED
, ICMP_TIMXCEED_INTRANS
, dest
, 0);
1885 ipforward_rtaddr
= (struct sockaddr_in
*) &cache_rt
->ro_dst
;
1886 if (cache_rt
->ro_rt
== NULL
||
1887 ipforward_rtaddr
->sin_addr
.s_addr
!= pkt_dst
.s_addr
) {
1888 if (cache_rt
->ro_rt
!= NULL
) {
1889 RTFREE(cache_rt
->ro_rt
);
1890 cache_rt
->ro_rt
= NULL
;
1892 ipforward_rtaddr
->sin_family
= AF_INET
;
1893 ipforward_rtaddr
->sin_len
= sizeof(struct sockaddr_in
);
1894 ipforward_rtaddr
->sin_addr
= pkt_dst
;
1895 rtalloc_ign(cache_rt
, RTF_PRCLONING
);
1896 if (cache_rt
->ro_rt
== NULL
) {
1897 icmp_error(m
, ICMP_UNREACH
, ICMP_UNREACH_HOST
, dest
, 0);
1901 rt
= cache_rt
->ro_rt
;
1904 * Save the IP header and at most 8 bytes of the payload,
1905 * in case we need to generate an ICMP message to the src.
1907 * XXX this can be optimized a lot by saving the data in a local
1908 * buffer on the stack (72 bytes at most), and only allocating the
1909 * mbuf if really necessary. The vast majority of the packets
1910 * are forwarded without having to send an ICMP back (either
1911 * because unnecessary, or because rate limited), so we are
1912 * really we are wasting a lot of work here.
1914 * We don't use m_copy() because it might return a reference
1915 * to a shared cluster. Both this function and ip_output()
1916 * assume exclusive access to the IP header in `m', so any
1917 * data in a cluster may change before we reach icmp_error().
1919 MGETHDR(mcopy
, MB_DONTWAIT
, m
->m_type
);
1920 if (mcopy
!= NULL
&& !m_dup_pkthdr(mcopy
, m
, MB_DONTWAIT
)) {
1922 * It's probably ok if the pkthdr dup fails (because
1923 * the deep copy of the tag chain failed), but for now
1924 * be conservative and just discard the copy since
1925 * code below may some day want the tags.
1930 if (mcopy
!= NULL
) {
1931 mcopy
->m_len
= imin((IP_VHL_HL(ip
->ip_vhl
) << 2) + 8,
1933 mcopy
->m_pkthdr
.len
= mcopy
->m_len
;
1934 m_copydata(m
, 0, mcopy
->m_len
, mtod(mcopy
, caddr_t
));
1938 ip
->ip_ttl
-= IPTTLDEC
;
1941 * If forwarding packet using same interface that it came in on,
1942 * perhaps should send a redirect to sender to shortcut a hop.
1943 * Only send redirect if source is sending directly to us,
1944 * and if packet was not source routed (or has any options).
1945 * Also, don't send redirect if forwarding using a default route
1946 * or a route modified by a redirect.
1948 if (rt
->rt_ifp
== m
->m_pkthdr
.rcvif
&&
1949 !(rt
->rt_flags
& (RTF_DYNAMIC
| RTF_MODIFIED
)) &&
1950 satosin(rt_key(rt
))->sin_addr
.s_addr
!= INADDR_ANY
&&
1951 ipsendredirects
&& !using_srcrt
&& next_hop
== NULL
) {
1952 u_long src
= ntohl(ip
->ip_src
.s_addr
);
1953 struct in_ifaddr
*rt_ifa
= (struct in_ifaddr
*)rt
->rt_ifa
;
1955 if (rt_ifa
!= NULL
&&
1956 (src
& rt_ifa
->ia_subnetmask
) == rt_ifa
->ia_subnet
) {
1957 if (rt
->rt_flags
& RTF_GATEWAY
)
1958 dest
= satosin(rt
->rt_gateway
)->sin_addr
.s_addr
;
1960 dest
= pkt_dst
.s_addr
;
1962 * Router requirements says to only send
1965 type
= ICMP_REDIRECT
;
1966 code
= ICMP_REDIRECT_HOST
;
1969 kprintf("redirect (%d) to %x\n", code
, dest
);
1974 error
= ip_output(m
, NULL
, cache_rt
, IP_FORWARDING
, NULL
, NULL
);
1976 ipstat
.ips_forward
++;
1979 ipflow_create(cache_rt
, mcopy
);
1982 return; /* most common case */
1984 ipstat
.ips_redirectsent
++;
1987 ipstat
.ips_cantforward
++;
1994 * Send ICMP message.
1999 case 0: /* forwarded, but need redirect */
2000 /* type, code set above */
2003 case ENETUNREACH
: /* shouldn't happen, checked above */
2008 type
= ICMP_UNREACH
;
2009 code
= ICMP_UNREACH_HOST
;
2013 type
= ICMP_UNREACH
;
2014 code
= ICMP_UNREACH_NEEDFRAG
;
2017 * If the packet is routed over IPsec tunnel, tell the
2018 * originator the tunnel MTU.
2019 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
2022 if (cache_rt
->ro_rt
!= NULL
) {
2023 struct secpolicy
*sp
= NULL
;
2028 sp
= ipsec4_getpolicybyaddr(mcopy
,
2034 destmtu
= cache_rt
->ro_rt
->rt_ifp
->if_mtu
;
2036 /* count IPsec header size */
2037 ipsechdr
= ipsec4_hdrsiz(mcopy
,
2042 * find the correct route for outer IPv4
2043 * header, compute tunnel MTU.
2046 if (sp
->req
!= NULL
&& sp
->req
->sav
!= NULL
&&
2047 sp
->req
->sav
->sah
!= NULL
) {
2048 ro
= &sp
->req
->sav
->sah
->sa_route
;
2049 if (ro
->ro_rt
!= NULL
&&
2050 ro
->ro_rt
->rt_ifp
!= NULL
) {
2052 ro
->ro_rt
->rt_ifp
->if_mtu
;
2053 destmtu
-= ipsechdr
;
2062 * If the packet is routed over IPsec tunnel, tell the
2063 * originator the tunnel MTU.
2064 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
2067 if (cache_rt
->ro_rt
!= NULL
) {
2068 struct secpolicy
*sp
= NULL
;
2073 sp
= ipsec_getpolicybyaddr(mcopy
,
2079 destmtu
= cache_rt
->ro_rt
->rt_ifp
->if_mtu
;
2081 /* count IPsec header size */
2082 ipsechdr
= ipsec4_hdrsiz(mcopy
,
2087 * find the correct route for outer IPv4
2088 * header, compute tunnel MTU.
2091 if (sp
->req
!= NULL
&&
2092 sp
->req
->sav
!= NULL
&&
2093 sp
->req
->sav
->sah
!= NULL
) {
2094 ro
= &sp
->req
->sav
->sah
->sa_route
;
2095 if (ro
->ro_rt
!= NULL
&&
2096 ro
->ro_rt
->rt_ifp
!= NULL
) {
2098 ro
->ro_rt
->rt_ifp
->if_mtu
;
2099 destmtu
-= ipsechdr
;
2106 #else /* !IPSEC && !FAST_IPSEC */
2107 if (cache_rt
->ro_rt
!= NULL
)
2108 destmtu
= cache_rt
->ro_rt
->rt_ifp
->if_mtu
;
2110 ipstat
.ips_cantfrag
++;
2115 * A router should not generate ICMP_SOURCEQUENCH as
2116 * required in RFC1812 Requirements for IP Version 4 Routers.
2117 * Source quench could be a big problem under DoS attacks,
2118 * or if the underlying interface is rate-limited.
2119 * Those who need source quench packets may re-enable them
2120 * via the net.inet.ip.sendsourcequench sysctl.
2122 if (!ip_sendsourcequench
) {
2126 type
= ICMP_SOURCEQUENCH
;
2131 case EACCES
: /* ipfw denied packet */
2135 icmp_error(mcopy
, type
, code
, dest
, destmtu
);
2139 ip_savecontrol(struct inpcb
*inp
, struct mbuf
**mp
, struct ip
*ip
,
2142 if (inp
->inp_socket
->so_options
& SO_TIMESTAMP
) {
2146 *mp
= sbcreatecontrol((caddr_t
) &tv
, sizeof(tv
),
2147 SCM_TIMESTAMP
, SOL_SOCKET
);
2149 mp
= &(*mp
)->m_next
;
2151 if (inp
->inp_flags
& INP_RECVDSTADDR
) {
2152 *mp
= sbcreatecontrol((caddr_t
) &ip
->ip_dst
,
2153 sizeof(struct in_addr
), IP_RECVDSTADDR
, IPPROTO_IP
);
2155 mp
= &(*mp
)->m_next
;
2157 if (inp
->inp_flags
& INP_RECVTTL
) {
2158 *mp
= sbcreatecontrol((caddr_t
) &ip
->ip_ttl
,
2159 sizeof(u_char
), IP_RECVTTL
, IPPROTO_IP
);
2161 mp
= &(*mp
)->m_next
;
2165 * Moving these out of udp_input() made them even more broken
2166 * than they already were.
2168 /* options were tossed already */
2169 if (inp
->inp_flags
& INP_RECVOPTS
) {
2170 *mp
= sbcreatecontrol((caddr_t
) opts_deleted_above
,
2171 sizeof(struct in_addr
), IP_RECVOPTS
, IPPROTO_IP
);
2173 mp
= &(*mp
)->m_next
;
2175 /* ip_srcroute doesn't do what we want here, need to fix */
2176 if (inp
->inp_flags
& INP_RECVRETOPTS
) {
2177 *mp
= sbcreatecontrol((caddr_t
) ip_srcroute(),
2178 sizeof(struct in_addr
), IP_RECVRETOPTS
, IPPROTO_IP
);
2180 mp
= &(*mp
)->m_next
;
2183 if (inp
->inp_flags
& INP_RECVIF
) {
2186 struct sockaddr_dl sdl
;
2189 struct sockaddr_dl
*sdp
;
2190 struct sockaddr_dl
*sdl2
= &sdlbuf
.sdl
;
2192 if (((ifp
= m
->m_pkthdr
.rcvif
)) &&
2193 ((ifp
->if_index
!= 0) && (ifp
->if_index
<= if_index
))) {
2194 sdp
= IF_LLSOCKADDR(ifp
);
2196 * Change our mind and don't try copy.
2198 if ((sdp
->sdl_family
!= AF_LINK
) ||
2199 (sdp
->sdl_len
> sizeof(sdlbuf
))) {
2202 bcopy(sdp
, sdl2
, sdp
->sdl_len
);
2206 offsetof(struct sockaddr_dl
, sdl_data
[0]);
2207 sdl2
->sdl_family
= AF_LINK
;
2208 sdl2
->sdl_index
= 0;
2209 sdl2
->sdl_nlen
= sdl2
->sdl_alen
= sdl2
->sdl_slen
= 0;
2211 *mp
= sbcreatecontrol((caddr_t
) sdl2
, sdl2
->sdl_len
,
2212 IP_RECVIF
, IPPROTO_IP
);
2214 mp
= &(*mp
)->m_next
;
2219 * XXX these routines are called from the upper part of the kernel.
2221 * They could also be moved to ip_mroute.c, since all the RSVP
2222 * handling is done there already.
2225 ip_rsvp_init(struct socket
*so
)
2227 if (so
->so_type
!= SOCK_RAW
||
2228 so
->so_proto
->pr_protocol
!= IPPROTO_RSVP
)
2231 if (ip_rsvpd
!= NULL
)
2236 * This may seem silly, but we need to be sure we don't over-increment
2237 * the RSVP counter, in case something slips up.
2252 * This may seem silly, but we need to be sure we don't over-decrement
2253 * the RSVP counter, in case something slips up.
2263 rsvp_input(struct mbuf
*m
, ...) /* XXX must fixup manually */
2269 off
= __va_arg(ap
, int);
2270 proto
= __va_arg(ap
, int);
2273 if (rsvp_input_p
) { /* call the real one if loaded */
2274 rsvp_input_p(m
, off
, proto
);
2278 /* Can still get packets with rsvp_on = 0 if there is a local member
2279 * of the group to which the RSVP packet is addressed. But in this
2280 * case we want to throw the packet away.
2288 if (ip_rsvpd
!= NULL
) {
2289 rip_input(m
, off
, proto
);
2292 /* Drop the packet */