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
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of The DragonFly Project nor the names of its
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
22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
24 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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39 * modification, are permitted provided that the following conditions
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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 1.115 2008/10/28 07:09:26 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>
98 #include <sys/mplock2.h>
100 #include <machine/stdarg.h>
103 #include <net/if_types.h>
104 #include <net/if_var.h>
105 #include <net/if_dl.h>
106 #include <net/pfil.h>
107 #include <net/route.h>
108 #include <net/netisr.h>
110 #include <netinet/in.h>
111 #include <netinet/in_systm.h>
112 #include <netinet/in_var.h>
113 #include <netinet/ip.h>
114 #include <netinet/in_pcb.h>
115 #include <netinet/ip_var.h>
116 #include <netinet/ip_icmp.h>
117 #include <netinet/ip_divert.h>
118 #include <netinet/ip_flow.h>
120 #include <sys/thread2.h>
121 #include <sys/msgport2.h>
122 #include <net/netmsg2.h>
124 #include <sys/socketvar.h>
126 #include <net/ipfw/ip_fw.h>
127 #include <net/dummynet/ip_dummynet.h>
130 #include <netinet6/ipsec.h>
131 #include <netproto/key/key.h>
135 #include <netproto/ipsec/ipsec.h>
136 #include <netproto/ipsec/key.h>
140 static int ip_rsvp_on
;
141 struct socket
*ip_rsvpd
;
144 TUNABLE_INT("net.inet.ip.mpsafe", &ip_mpsafe
);
146 int ipforwarding
= 0;
147 SYSCTL_INT(_net_inet_ip
, IPCTL_FORWARDING
, forwarding
, CTLFLAG_RW
,
148 &ipforwarding
, 0, "Enable IP forwarding between interfaces");
150 static int ipsendredirects
= 1; /* XXX */
151 SYSCTL_INT(_net_inet_ip
, IPCTL_SENDREDIRECTS
, redirect
, CTLFLAG_RW
,
152 &ipsendredirects
, 0, "Enable sending IP redirects");
154 int ip_defttl
= IPDEFTTL
;
155 SYSCTL_INT(_net_inet_ip
, IPCTL_DEFTTL
, ttl
, CTLFLAG_RW
,
156 &ip_defttl
, 0, "Maximum TTL on IP packets");
158 static int ip_dosourceroute
= 0;
159 SYSCTL_INT(_net_inet_ip
, IPCTL_SOURCEROUTE
, sourceroute
, CTLFLAG_RW
,
160 &ip_dosourceroute
, 0, "Enable forwarding source routed IP packets");
162 static int ip_acceptsourceroute
= 0;
163 SYSCTL_INT(_net_inet_ip
, IPCTL_ACCEPTSOURCEROUTE
, accept_sourceroute
,
164 CTLFLAG_RW
, &ip_acceptsourceroute
, 0,
165 "Enable accepting source routed IP packets");
167 static int ip_keepfaith
= 0;
168 SYSCTL_INT(_net_inet_ip
, IPCTL_KEEPFAITH
, keepfaith
, CTLFLAG_RW
,
170 "Enable packet capture for FAITH IPv4->IPv6 translator daemon");
172 static int nipq
= 0; /* total # of reass queues */
174 SYSCTL_INT(_net_inet_ip
, OID_AUTO
, maxfragpackets
, CTLFLAG_RW
,
176 "Maximum number of IPv4 fragment reassembly queue entries");
178 static int maxfragsperpacket
;
179 SYSCTL_INT(_net_inet_ip
, OID_AUTO
, maxfragsperpacket
, CTLFLAG_RW
,
180 &maxfragsperpacket
, 0,
181 "Maximum number of IPv4 fragments allowed per packet");
183 static int ip_sendsourcequench
= 0;
184 SYSCTL_INT(_net_inet_ip
, OID_AUTO
, sendsourcequench
, CTLFLAG_RW
,
185 &ip_sendsourcequench
, 0,
186 "Enable the transmission of source quench packets");
188 int ip_do_randomid
= 1;
189 SYSCTL_INT(_net_inet_ip
, OID_AUTO
, random_id
, CTLFLAG_RW
,
191 "Assign random ip_id values");
193 * XXX - Setting ip_checkinterface mostly implements the receive side of
194 * the Strong ES model described in RFC 1122, but since the routing table
195 * and transmit implementation do not implement the Strong ES model,
196 * setting this to 1 results in an odd hybrid.
198 * XXX - ip_checkinterface currently must be disabled if you use ipnat
199 * to translate the destination address to another local interface.
201 * XXX - ip_checkinterface must be disabled if you add IP aliases
202 * to the loopback interface instead of the interface where the
203 * packets for those addresses are received.
205 static int ip_checkinterface
= 0;
206 SYSCTL_INT(_net_inet_ip
, OID_AUTO
, check_interface
, CTLFLAG_RW
,
207 &ip_checkinterface
, 0, "Verify packet arrives on correct interface");
210 static int ipprintfs
= 0;
213 extern int udp_mpsafe_proto
;
214 extern int tcp_mpsafe_proto
;
216 extern struct domain inetdomain
;
217 extern struct protosw inetsw
[];
218 u_char ip_protox
[IPPROTO_MAX
];
219 struct in_ifaddrhead in_ifaddrheads
[MAXCPU
]; /* first inet address */
220 struct in_ifaddrhashhead
*in_ifaddrhashtbls
[MAXCPU
];
221 /* inet addr hash table */
222 u_long in_ifaddrhmask
; /* mask for hash table */
224 struct ip_stats ipstats_percpu
[MAXCPU
];
227 sysctl_ipstats(SYSCTL_HANDLER_ARGS
)
231 for (cpu
= 0; cpu
< ncpus
; ++cpu
) {
232 if ((error
= SYSCTL_OUT(req
, &ipstats_percpu
[cpu
],
233 sizeof(struct ip_stats
))))
235 if ((error
= SYSCTL_IN(req
, &ipstats_percpu
[cpu
],
236 sizeof(struct ip_stats
))))
242 SYSCTL_PROC(_net_inet_ip
, IPCTL_STATS
, stats
, (CTLTYPE_OPAQUE
| CTLFLAG_RW
),
243 0, 0, sysctl_ipstats
, "S,ip_stats", "IP statistics");
245 SYSCTL_STRUCT(_net_inet_ip
, IPCTL_STATS
, stats
, CTLFLAG_RW
,
246 &ipstat
, ip_stats
, "IP statistics");
249 /* Packet reassembly stuff */
250 #define IPREASS_NHASH_LOG2 6
251 #define IPREASS_NHASH (1 << IPREASS_NHASH_LOG2)
252 #define IPREASS_HMASK (IPREASS_NHASH - 1)
253 #define IPREASS_HASH(x,y) \
254 (((((x) & 0xF) | ((((x) >> 8) & 0xF) << 4)) ^ (y)) & IPREASS_HMASK)
256 static struct ipq ipq
[IPREASS_NHASH
];
259 SYSCTL_INT(_net_inet_ip
, IPCTL_DEFMTU
, mtu
, CTLFLAG_RW
,
260 &ip_mtu
, 0, "Default MTU");
264 static int ipstealth
= 0;
265 SYSCTL_INT(_net_inet_ip
, OID_AUTO
, stealth
, CTLFLAG_RW
, &ipstealth
, 0, "");
267 static const int ipstealth
= 0;
270 struct mbuf
*(*ip_divert_p
)(struct mbuf
*, int, int);
272 struct pfil_head inet_pfil_hook
;
275 * struct ip_srcrt_opt is used to store packet state while it travels
278 * XXX Note that the code even makes assumptions on the size and
279 * alignment of fields inside struct ip_srcrt so e.g. adding some
280 * fields will break the code. This needs to be fixed.
282 * We need to save the IP options in case a protocol wants to respond
283 * to an incoming packet over the same route if the packet got here
284 * using IP source routing. This allows connection establishment and
285 * maintenance when the remote end is on a network that is not known
289 struct in_addr dst
; /* final destination */
290 char nop
; /* one NOP to align */
291 char srcopt
[IPOPT_OFFSET
+ 1]; /* OPTVAL, OLEN and OFFSET */
292 struct in_addr route
[MAX_IPOPTLEN
/sizeof(struct in_addr
)];
295 struct ip_srcrt_opt
{
297 struct ip_srcrt ip_srcrt
;
300 static MALLOC_DEFINE(M_IPQ
, "ipq", "IP Fragment Management");
301 static struct malloc_pipe ipq_mpipe
;
303 static void save_rte(struct mbuf
*, u_char
*, struct in_addr
);
304 static int ip_dooptions(struct mbuf
*m
, int, struct sockaddr_in
*);
305 static void ip_freef(struct ipq
*);
306 static void ip_input_handler(struct netmsg
*);
309 * IP initialization: fill in IP protocol switch table.
310 * All protocols not implemented in kernel go to raw IP protocol handler.
323 * Make sure we can handle a reasonable number of fragments but
324 * cap it at 4000 (XXX).
326 mpipe_init(&ipq_mpipe
, M_IPQ
, sizeof(struct ipq
),
327 IFQ_MAXLEN
, 4000, 0, NULL
);
328 for (i
= 0; i
< ncpus
; ++i
) {
329 TAILQ_INIT(&in_ifaddrheads
[i
]);
330 in_ifaddrhashtbls
[i
] =
331 hashinit(INADDR_NHASH
, M_IFADDR
, &in_ifaddrhmask
);
333 pr
= pffindproto(PF_INET
, IPPROTO_RAW
, SOCK_RAW
);
336 for (i
= 0; i
< IPPROTO_MAX
; i
++)
337 ip_protox
[i
] = pr
- inetsw
;
338 for (pr
= inetdomain
.dom_protosw
;
339 pr
< inetdomain
.dom_protoswNPROTOSW
; pr
++) {
340 if (pr
->pr_domain
->dom_family
== PF_INET
&& pr
->pr_protocol
) {
341 if (pr
->pr_protocol
!= IPPROTO_RAW
)
342 ip_protox
[pr
->pr_protocol
] = pr
- inetsw
;
345 switch (pr
->pr_protocol
) {
347 if (tcp_mpsafe_proto
)
348 pr
->pr_flags
|= PR_MPSAFE
;
352 if (udp_mpsafe_proto
)
353 pr
->pr_flags
|= PR_MPSAFE
;
359 inet_pfil_hook
.ph_type
= PFIL_TYPE_AF
;
360 inet_pfil_hook
.ph_af
= AF_INET
;
361 if ((i
= pfil_head_register(&inet_pfil_hook
)) != 0) {
362 kprintf("%s: WARNING: unable to register pfil hook, "
363 "error %d\n", __func__
, i
);
366 for (i
= 0; i
< IPREASS_NHASH
; i
++)
367 ipq
[i
].next
= ipq
[i
].prev
= &ipq
[i
];
369 maxnipq
= nmbclusters
/ 32;
370 maxfragsperpacket
= 16;
372 ip_id
= time_second
& 0xffff;
375 * Initialize IP statistics counters for each CPU.
379 for (cpu
= 0; cpu
< ncpus
; ++cpu
) {
380 bzero(&ipstats_percpu
[cpu
], sizeof(struct ip_stats
));
383 bzero(&ipstat
, sizeof(struct ip_stats
));
386 #if defined(IPSEC) || defined(FAST_IPSEC)
387 /* XXX IPSEC is not MPSAFE yet */
388 flags
= NETISR_FLAG_NOTMPSAFE
;
391 kprintf("ip: MPSAFE\n");
392 flags
= NETISR_FLAG_MPSAFE
;
394 flags
= NETISR_FLAG_NOTMPSAFE
;
397 netisr_register(NETISR_IP
, ip_mport_in
, ip_mport_pktinfo
,
398 ip_input_handler
, flags
);
401 /* Do transport protocol processing. */
403 transport_processing_oncpu(struct mbuf
*m
, int hlen
, struct ip
*ip
)
405 const struct protosw
*pr
= &inetsw
[ip_protox
[ip
->ip_p
]];
408 * Switch out to protocol's input routine.
411 pr
->pr_input(m
, hlen
, ip
->ip_p
);
416 transport_processing_handler(netmsg_t netmsg
)
418 struct netmsg_packet
*pmsg
= (struct netmsg_packet
*)netmsg
;
422 ip
= mtod(pmsg
->nm_packet
, struct ip
*);
423 hlen
= pmsg
->nm_netmsg
.nm_lmsg
.u
.ms_result
;
425 transport_processing_oncpu(pmsg
->nm_packet
, hlen
, ip
);
426 /* netmsg was embedded in the mbuf, do not reply! */
430 ip_input_handler(struct netmsg
*msg0
)
432 struct mbuf
*m
= ((struct netmsg_packet
*)msg0
)->nm_packet
;
435 /* msg0 was embedded in the mbuf, do not reply! */
439 * IP input routine. Checksum and byte swap header. If fragmented
440 * try to reassemble. Process options. Pass to next level.
443 ip_input(struct mbuf
*m
)
446 struct in_ifaddr
*ia
= NULL
;
447 struct in_ifaddr_container
*iac
;
450 struct in_addr pkt_dst
;
451 boolean_t using_srcrt
= FALSE
; /* forward (by PFIL_HOOKS) */
452 boolean_t needredispatch
= FALSE
;
453 struct in_addr odst
; /* original dst address(NAT) */
455 struct sockaddr_in
*next_hop
= NULL
;
457 struct tdb_ident
*tdbi
;
458 struct secpolicy
*sp
;
464 if (m
->m_pkthdr
.fw_flags
& IPFORWARD_MBUF_TAGGED
) {
466 mtag
= m_tag_find(m
, PACKET_TAG_IPFORWARD
, NULL
);
467 KKASSERT(mtag
!= NULL
);
468 next_hop
= m_tag_data(mtag
);
471 if (m
->m_pkthdr
.fw_flags
& DUMMYNET_MBUF_TAGGED
) {
472 /* dummynet already filtered us */
473 ip
= mtod(m
, struct ip
*);
474 hlen
= IP_VHL_HL(ip
->ip_vhl
) << 2;
480 /* length checks already done in ip_mport() */
481 KASSERT(m
->m_len
>= sizeof(struct ip
), ("IP header not in one mbuf"));
482 ip
= mtod(m
, struct ip
*);
484 if (IP_VHL_V(ip
->ip_vhl
) != IPVERSION
) {
485 ipstat
.ips_badvers
++;
489 hlen
= IP_VHL_HL(ip
->ip_vhl
) << 2;
490 /* length checks already done in ip_mport() */
491 KASSERT(hlen
>= sizeof(struct ip
), ("IP header len too small"));
492 KASSERT(m
->m_len
>= hlen
, ("complete IP header not in one mbuf"));
494 /* 127/8 must not appear on wire - RFC1122 */
495 if ((ntohl(ip
->ip_dst
.s_addr
) >> IN_CLASSA_NSHIFT
) == IN_LOOPBACKNET
||
496 (ntohl(ip
->ip_src
.s_addr
) >> IN_CLASSA_NSHIFT
) == IN_LOOPBACKNET
) {
497 if (!(m
->m_pkthdr
.rcvif
->if_flags
& IFF_LOOPBACK
)) {
498 ipstat
.ips_badaddr
++;
503 if (m
->m_pkthdr
.csum_flags
& CSUM_IP_CHECKED
) {
504 sum
= !(m
->m_pkthdr
.csum_flags
& CSUM_IP_VALID
);
506 if (hlen
== sizeof(struct ip
))
507 sum
= in_cksum_hdr(ip
);
509 sum
= in_cksum(m
, hlen
);
517 if (altq_input
!= NULL
&& (*altq_input
)(m
, AF_INET
) == 0) {
518 /* packet is dropped by traffic conditioner */
523 * Convert fields to host representation.
525 ip
->ip_len
= ntohs(ip
->ip_len
);
526 ip
->ip_off
= ntohs(ip
->ip_off
);
528 /* length checks already done in ip_mport() */
529 KASSERT(ip
->ip_len
>= hlen
, ("total length less then header length"));
530 KASSERT(m
->m_pkthdr
.len
>= ip
->ip_len
, ("mbuf too short"));
533 * Trim mbufs if longer than the IP header would have us expect.
535 if (m
->m_pkthdr
.len
> ip
->ip_len
) {
536 if (m
->m_len
== m
->m_pkthdr
.len
) {
537 m
->m_len
= ip
->ip_len
;
538 m
->m_pkthdr
.len
= ip
->ip_len
;
540 m_adj(m
, ip
->ip_len
- m
->m_pkthdr
.len
);
543 #if defined(IPSEC) && !defined(IPSEC_FILTERGIF)
545 * Bypass packet filtering for packets from a tunnel (gif).
547 if (ipsec_gethist(m
, NULL
))
553 * Right now when no processing on packet has done
554 * and it is still fresh out of network we do our black
556 * - Firewall: deny/allow/divert
557 * - Xlate: translate packet's addr/port (NAT).
558 * - Pipe: pass pkt through dummynet.
559 * - Wrap: fake packet's addr/port <unimpl.>
560 * - Encapsulate: put it in another IP and send out. <unimp.>
565 * If we've been forwarded from the output side, then
566 * skip the firewall a second time
568 if (next_hop
!= NULL
)
572 if (!pfil_has_hooks(&inet_pfil_hook
)) {
573 if (m
->m_pkthdr
.fw_flags
& DUMMYNET_MBUF_TAGGED
) {
575 * Strip dummynet tags from stranded packets
577 mtag
= m_tag_find(m
, PACKET_TAG_DUMMYNET
, NULL
);
578 KKASSERT(mtag
!= NULL
);
579 m_tag_delete(m
, mtag
);
580 m
->m_pkthdr
.fw_flags
&= ~DUMMYNET_MBUF_TAGGED
;
586 * Run through list of hooks for input packets.
588 * NB: Beware of the destination address changing (e.g.
589 * by NAT rewriting). When this happens, tell
590 * ip_forward to do the right thing.
593 if (pfil_run_hooks(&inet_pfil_hook
, &m
, m
->m_pkthdr
.rcvif
, PFIL_IN
))
595 if (m
== NULL
) /* consumed by filter */
597 ip
= mtod(m
, struct ip
*);
598 hlen
= IP_VHL_HL(ip
->ip_vhl
) << 2;
599 using_srcrt
= (odst
.s_addr
!= ip
->ip_dst
.s_addr
);
601 if (m
->m_pkthdr
.fw_flags
& IPFORWARD_MBUF_TAGGED
) {
602 mtag
= m_tag_find(m
, PACKET_TAG_IPFORWARD
, NULL
);
603 KKASSERT(mtag
!= NULL
);
604 next_hop
= m_tag_data(mtag
);
606 if (m
->m_pkthdr
.fw_flags
& DUMMYNET_MBUF_TAGGED
) {
610 if (m
->m_pkthdr
.fw_flags
& FW_MBUF_REDISPATCH
) {
611 needredispatch
= TRUE
;
612 m
->m_pkthdr
.fw_flags
&= ~FW_MBUF_REDISPATCH
;
616 * Process options and, if not destined for us,
617 * ship it on. ip_dooptions returns 1 when an
618 * error was detected (causing an icmp message
619 * to be sent and the original packet to be freed).
621 if (hlen
> sizeof(struct ip
) && ip_dooptions(m
, 0, next_hop
))
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.
630 if (rsvp_on
&& ip
->ip_p
== IPPROTO_RSVP
)
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
639 if (TAILQ_EMPTY(&in_ifaddrheads
[mycpuid
]) &&
640 !(m
->m_flags
& (M_MCAST
| M_BCAST
)))
644 * Cache the destination address of the packet; this may be
645 * changed by use of 'ipfw fwd'.
647 pkt_dst
= next_hop
? next_hop
->sin_addr
: ip
->ip_dst
;
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
656 * XXX - Checking also should be disabled if the destination
657 * address is ipnat'ed to a different interface.
659 * XXX - Checking is incompatible with IP aliases added
660 * to the loopback interface instead of the interface where
661 * the packets are received.
663 checkif
= ip_checkinterface
&&
665 m
->m_pkthdr
.rcvif
!= NULL
&&
666 !(m
->m_pkthdr
.rcvif
->if_flags
& IFF_LOOPBACK
) &&
670 * Check for exact addresses in the hash bucket.
672 LIST_FOREACH(iac
, INADDR_HASH(pkt_dst
.s_addr
), ia_hash
) {
676 * If the address matches, verify that the packet
677 * arrived via the correct interface if checking is
680 if (IA_SIN(ia
)->sin_addr
.s_addr
== pkt_dst
.s_addr
&&
681 (!checkif
|| ia
->ia_ifp
== m
->m_pkthdr
.rcvif
))
687 * Check for broadcast addresses.
689 * Only accept broadcast packets that arrive via the matching
690 * interface. Reception of forwarded directed broadcasts would
691 * be handled via ip_forward() and ether_output() with the loopback
692 * into the stack for SIMPLEX interfaces handled by ether_output().
694 if (m
->m_pkthdr
.rcvif
->if_flags
& IFF_BROADCAST
) {
695 struct ifaddr_container
*ifac
;
697 TAILQ_FOREACH(ifac
, &m
->m_pkthdr
.rcvif
->if_addrheads
[mycpuid
],
699 struct ifaddr
*ifa
= ifac
->ifa
;
701 if (ifa
->ifa_addr
== NULL
) /* shutdown/startup race */
703 if (ifa
->ifa_addr
->sa_family
!= AF_INET
)
706 if (satosin(&ia
->ia_broadaddr
)->sin_addr
.s_addr
==
709 if (ia
->ia_netbroadcast
.s_addr
== pkt_dst
.s_addr
)
712 if (IA_SIN(ia
)->sin_addr
.s_addr
== INADDR_ANY
)
717 if (IN_MULTICAST(ntohl(ip
->ip_dst
.s_addr
))) {
718 struct in_multi
*inm
;
720 /* XXX Multicast is not MPSAFE yet */
723 if (ip_mrouter
!= NULL
) {
725 * If we are acting as a multicast router, all
726 * incoming multicast packets are passed to the
727 * kernel-level multicast forwarding function.
728 * The packet is returned (relatively) intact; if
729 * ip_mforward() returns a non-zero value, the packet
730 * must be discarded, else it may be accepted below.
732 if (ip_mforward
!= NULL
&&
733 ip_mforward(ip
, m
->m_pkthdr
.rcvif
, m
, NULL
) != 0) {
735 ipstat
.ips_cantforward
++;
741 * The process-level routing daemon needs to receive
742 * all multicast IGMP packets, whether or not this
743 * host belongs to their destination groups.
745 if (ip
->ip_p
== IPPROTO_IGMP
) {
749 ipstat
.ips_forward
++;
752 * See if we belong to the destination multicast group on the
755 IN_LOOKUP_MULTI(ip
->ip_dst
, m
->m_pkthdr
.rcvif
, inm
);
758 ipstat
.ips_notmember
++;
766 if (ip
->ip_dst
.s_addr
== INADDR_BROADCAST
)
768 if (ip
->ip_dst
.s_addr
== INADDR_ANY
)
772 * FAITH(Firewall Aided Internet Translator)
774 if (m
->m_pkthdr
.rcvif
&& m
->m_pkthdr
.rcvif
->if_type
== IFT_FAITH
) {
776 if (ip
->ip_p
== IPPROTO_TCP
|| ip
->ip_p
== IPPROTO_ICMP
)
784 * Not for us; forward if possible and desirable.
787 ipstat
.ips_cantforward
++;
792 * Enforce inbound IPsec SPD.
794 if (ipsec4_in_reject(m
, NULL
)) {
795 ipsecstat
.in_polvio
++;
800 mtag
= m_tag_find(m
, PACKET_TAG_IPSEC_IN_DONE
, NULL
);
803 tdbi
= (struct tdb_ident
*)m_tag_data(mtag
);
804 sp
= ipsec_getpolicy(tdbi
, IPSEC_DIR_INBOUND
);
806 sp
= ipsec_getpolicybyaddr(m
, IPSEC_DIR_INBOUND
,
807 IP_FORWARDING
, &error
);
809 if (sp
== NULL
) { /* NB: can happen if error */
811 /*XXX error stat???*/
812 DPRINTF(("ip_input: no SP for forwarding\n")); /*XXX*/
817 * Check security policy against packet attributes.
819 error
= ipsec_in_reject(sp
, m
);
823 ipstat
.ips_cantforward
++;
827 ip_forward(m
, using_srcrt
, next_hop
);
834 * IPSTEALTH: Process non-routing options only
835 * if the packet is destined for us.
838 hlen
> sizeof(struct ip
) &&
839 ip_dooptions(m
, 1, next_hop
))
842 /* Count the packet in the ip address stats */
844 ia
->ia_ifa
.if_ipackets
++;
845 ia
->ia_ifa
.if_ibytes
+= m
->m_pkthdr
.len
;
849 * If offset or IP_MF are set, must reassemble.
850 * Otherwise, nothing need be done.
851 * (We could look in the reassembly queue to see
852 * if the packet was previously fragmented,
853 * but it's not worth the time; just let them time out.)
855 if (ip
->ip_off
& (IP_MF
| IP_OFFMASK
)) {
857 * Attempt reassembly; if it succeeds, proceed.
858 * ip_reass() will return a different mbuf.
863 ip
= mtod(m
, struct ip
*);
865 /* Get the header length of the reassembled packet */
866 hlen
= IP_VHL_HL(ip
->ip_vhl
) << 2;
868 needredispatch
= TRUE
;
875 * enforce IPsec policy checking if we are seeing last header.
876 * note that we do not visit this with protocols with pcb layer
877 * code - like udp/tcp/raw ip.
879 if ((inetsw
[ip_protox
[ip
->ip_p
]].pr_flags
& PR_LASTHDR
) &&
880 ipsec4_in_reject(m
, NULL
)) {
881 ipsecstat
.in_polvio
++;
887 * enforce IPsec policy checking if we are seeing last header.
888 * note that we do not visit this with protocols with pcb layer
889 * code - like udp/tcp/raw ip.
891 if (inetsw
[ip_protox
[ip
->ip_p
]].pr_flags
& PR_LASTHDR
) {
893 * Check if the packet has already had IPsec processing
894 * done. If so, then just pass it along. This tag gets
895 * set during AH, ESP, etc. input handling, before the
896 * packet is returned to the ip input queue for delivery.
898 mtag
= m_tag_find(m
, PACKET_TAG_IPSEC_IN_DONE
, NULL
);
901 tdbi
= (struct tdb_ident
*)m_tag_data(mtag
);
902 sp
= ipsec_getpolicy(tdbi
, IPSEC_DIR_INBOUND
);
904 sp
= ipsec_getpolicybyaddr(m
, IPSEC_DIR_INBOUND
,
905 IP_FORWARDING
, &error
);
909 * Check security policy against packet attributes.
911 error
= ipsec_in_reject(sp
, m
);
914 /* XXX error stat??? */
916 DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/
923 #endif /* FAST_IPSEC */
926 * NOTE: ip_len in host form and adjusted down by hlen for
927 * protocol processing.
929 ipstat
.ips_delivered
++;
930 if (needredispatch
) {
931 struct netmsg_packet
*pmsg
;
934 ip
->ip_off
= htons(ip
->ip_off
);
935 ip
->ip_len
= htons(ip
->ip_len
+ hlen
);
936 port
= ip_mport_in(&m
);
940 pmsg
= &m
->m_hdr
.mh_netmsg
;
941 netmsg_init(&pmsg
->nm_netmsg
, NULL
, &netisr_apanic_rport
,
942 MSGF_MPSAFE
, transport_processing_handler
);
944 pmsg
->nm_netmsg
.nm_lmsg
.u
.ms_result
= hlen
;
946 ip
= mtod(m
, struct ip
*);
947 ip
->ip_len
= ntohs(ip
->ip_len
) - hlen
;
948 ip
->ip_off
= ntohs(ip
->ip_off
);
949 lwkt_sendmsg(port
, &pmsg
->nm_netmsg
.nm_lmsg
);
951 transport_processing_oncpu(m
, hlen
, ip
);
960 * Take incoming datagram fragment and try to reassemble it into
961 * whole datagram. If a chain for reassembly of this datagram already
962 * exists, then it is given as fp; otherwise have to make a chain.
965 ip_reass(struct mbuf
*m
)
967 struct ip
*ip
= mtod(m
, struct ip
*);
968 struct mbuf
*p
= NULL
, *q
, *nq
;
970 struct ipq
*fp
= NULL
;
971 int hlen
= IP_VHL_HL(ip
->ip_vhl
) << 2;
975 /* If maxnipq is 0, never accept fragments. */
977 ipstat
.ips_fragments
++;
978 ipstat
.ips_fragdropped
++;
983 sum
= IPREASS_HASH(ip
->ip_src
.s_addr
, ip
->ip_id
);
985 * Look for queue of fragments of this datagram.
987 for (fp
= ipq
[sum
].next
; fp
!= &ipq
[sum
]; fp
= fp
->next
)
988 if (ip
->ip_id
== fp
->ipq_id
&&
989 ip
->ip_src
.s_addr
== fp
->ipq_src
.s_addr
&&
990 ip
->ip_dst
.s_addr
== fp
->ipq_dst
.s_addr
&&
991 ip
->ip_p
== fp
->ipq_p
)
997 * Enforce upper bound on number of fragmented packets
998 * for which we attempt reassembly;
999 * If maxnipq is -1, accept all fragments without limitation.
1001 if (nipq
> maxnipq
&& maxnipq
> 0) {
1003 * drop something from the tail of the current queue
1004 * before proceeding further
1006 if (ipq
[sum
].prev
== &ipq
[sum
]) { /* gak */
1007 for (i
= 0; i
< IPREASS_NHASH
; i
++) {
1008 if (ipq
[i
].prev
!= &ipq
[i
]) {
1009 ipstat
.ips_fragtimeout
+=
1010 ipq
[i
].prev
->ipq_nfrags
;
1011 ip_freef(ipq
[i
].prev
);
1016 ipstat
.ips_fragtimeout
+=
1017 ipq
[sum
].prev
->ipq_nfrags
;
1018 ip_freef(ipq
[sum
].prev
);
1023 * Adjust ip_len to not reflect header,
1024 * convert offset of this to bytes.
1027 if (ip
->ip_off
& IP_MF
) {
1029 * Make sure that fragments have a data length
1030 * that's a non-zero multiple of 8 bytes.
1032 if (ip
->ip_len
== 0 || (ip
->ip_len
& 0x7) != 0) {
1033 ipstat
.ips_toosmall
++; /* XXX */
1037 m
->m_flags
|= M_FRAG
;
1039 m
->m_flags
&= ~M_FRAG
;
1042 ipstat
.ips_fragments
++;
1043 m
->m_pkthdr
.header
= ip
;
1046 * If the hardware has not done csum over this fragment
1047 * then csum_data is not valid at all.
1049 if ((m
->m_pkthdr
.csum_flags
& (CSUM_FRAG_NOT_CHECKED
| CSUM_DATA_VALID
))
1050 == (CSUM_FRAG_NOT_CHECKED
| CSUM_DATA_VALID
)) {
1051 m
->m_pkthdr
.csum_data
= 0;
1052 m
->m_pkthdr
.csum_flags
&= ~(CSUM_DATA_VALID
| CSUM_PSEUDO_HDR
);
1056 * Presence of header sizes in mbufs
1057 * would confuse code below.
1063 * If first fragment to arrive, create a reassembly queue.
1066 if ((fp
= mpipe_alloc_nowait(&ipq_mpipe
)) == NULL
)
1068 insque(fp
, &ipq
[sum
]);
1071 fp
->ipq_ttl
= IPFRAGTTL
;
1072 fp
->ipq_p
= ip
->ip_p
;
1073 fp
->ipq_id
= ip
->ip_id
;
1074 fp
->ipq_src
= ip
->ip_src
;
1075 fp
->ipq_dst
= ip
->ip_dst
;
1077 m
->m_nextpkt
= NULL
;
1083 #define GETIP(m) ((struct ip*)((m)->m_pkthdr.header))
1086 * Find a segment which begins after this one does.
1088 for (p
= NULL
, q
= fp
->ipq_frags
; q
; p
= q
, q
= q
->m_nextpkt
)
1089 if (GETIP(q
)->ip_off
> ip
->ip_off
)
1093 * If there is a preceding segment, it may provide some of
1094 * our data already. If so, drop the data from the incoming
1095 * segment. If it provides all of our data, drop us, otherwise
1096 * stick new segment in the proper place.
1098 * If some of the data is dropped from the the preceding
1099 * segment, then it's checksum is invalidated.
1102 i
= GETIP(p
)->ip_off
+ GETIP(p
)->ip_len
- ip
->ip_off
;
1104 if (i
>= ip
->ip_len
)
1107 m
->m_pkthdr
.csum_flags
= 0;
1111 m
->m_nextpkt
= p
->m_nextpkt
;
1114 m
->m_nextpkt
= fp
->ipq_frags
;
1119 * While we overlap succeeding segments trim them or,
1120 * if they are completely covered, dequeue them.
1122 for (; q
!= NULL
&& ip
->ip_off
+ ip
->ip_len
> GETIP(q
)->ip_off
;
1124 i
= (ip
->ip_off
+ ip
->ip_len
) - GETIP(q
)->ip_off
;
1125 if (i
< GETIP(q
)->ip_len
) {
1126 GETIP(q
)->ip_len
-= i
;
1127 GETIP(q
)->ip_off
+= i
;
1129 q
->m_pkthdr
.csum_flags
= 0;
1134 ipstat
.ips_fragdropped
++;
1136 q
->m_nextpkt
= NULL
;
1142 * Check for complete reassembly and perform frag per packet
1145 * Frag limiting is performed here so that the nth frag has
1146 * a chance to complete the packet before we drop the packet.
1147 * As a result, n+1 frags are actually allowed per packet, but
1148 * only n will ever be stored. (n = maxfragsperpacket.)
1152 for (p
= NULL
, q
= fp
->ipq_frags
; q
; p
= q
, q
= q
->m_nextpkt
) {
1153 if (GETIP(q
)->ip_off
!= next
) {
1154 if (fp
->ipq_nfrags
> maxfragsperpacket
) {
1155 ipstat
.ips_fragdropped
+= fp
->ipq_nfrags
;
1160 next
+= GETIP(q
)->ip_len
;
1162 /* Make sure the last packet didn't have the IP_MF flag */
1163 if (p
->m_flags
& M_FRAG
) {
1164 if (fp
->ipq_nfrags
> maxfragsperpacket
) {
1165 ipstat
.ips_fragdropped
+= fp
->ipq_nfrags
;
1172 * Reassembly is complete. Make sure the packet is a sane size.
1176 if (next
+ (IP_VHL_HL(ip
->ip_vhl
) << 2) > IP_MAXPACKET
) {
1177 ipstat
.ips_toolong
++;
1178 ipstat
.ips_fragdropped
+= fp
->ipq_nfrags
;
1184 * Concatenate fragments.
1191 q
->m_nextpkt
= NULL
;
1192 for (q
= nq
; q
!= NULL
; q
= nq
) {
1194 q
->m_nextpkt
= NULL
;
1195 m
->m_pkthdr
.csum_flags
&= q
->m_pkthdr
.csum_flags
;
1196 m
->m_pkthdr
.csum_data
+= q
->m_pkthdr
.csum_data
;
1201 * Clean up the 1's complement checksum. Carry over 16 bits must
1202 * be added back. This assumes no more then 65535 packet fragments
1203 * were reassembled. A second carry can also occur (but not a third).
1205 m
->m_pkthdr
.csum_data
= (m
->m_pkthdr
.csum_data
& 0xffff) +
1206 (m
->m_pkthdr
.csum_data
>> 16);
1207 if (m
->m_pkthdr
.csum_data
> 0xFFFF)
1208 m
->m_pkthdr
.csum_data
-= 0xFFFF;
1211 * Create header for new ip packet by
1212 * modifying header of first packet;
1213 * dequeue and discard fragment reassembly header.
1214 * Make header visible.
1217 ip
->ip_src
= fp
->ipq_src
;
1218 ip
->ip_dst
= fp
->ipq_dst
;
1221 mpipe_free(&ipq_mpipe
, fp
);
1222 m
->m_len
+= (IP_VHL_HL(ip
->ip_vhl
) << 2);
1223 m
->m_data
-= (IP_VHL_HL(ip
->ip_vhl
) << 2);
1224 /* some debugging cruft by sklower, below, will go away soon */
1225 if (m
->m_flags
& M_PKTHDR
) { /* XXX this should be done elsewhere */
1228 for (n
= m
; n
; n
= n
->m_next
)
1230 m
->m_pkthdr
.len
= plen
;
1233 ipstat
.ips_reassembled
++;
1237 ipstat
.ips_fragdropped
++;
1247 * Free a fragment reassembly header and all
1248 * associated datagrams.
1251 ip_freef(struct ipq
*fp
)
1255 while (fp
->ipq_frags
) {
1257 fp
->ipq_frags
= q
->m_nextpkt
;
1258 q
->m_nextpkt
= NULL
;
1262 mpipe_free(&ipq_mpipe
, fp
);
1267 * IP timer processing;
1268 * if a timer expires on a reassembly
1269 * queue, discard it.
1278 for (i
= 0; i
< IPREASS_NHASH
; i
++) {
1282 while (fp
!= &ipq
[i
]) {
1285 if (fp
->prev
->ipq_ttl
== 0) {
1286 ipstat
.ips_fragtimeout
+= fp
->prev
->ipq_nfrags
;
1292 * If we are over the maximum number of fragments
1293 * (due to the limit being lowered), drain off
1294 * enough to get down to the new limit.
1296 if (maxnipq
>= 0 && nipq
> maxnipq
) {
1297 for (i
= 0; i
< IPREASS_NHASH
; i
++) {
1298 while (nipq
> maxnipq
&&
1299 (ipq
[i
].next
!= &ipq
[i
])) {
1300 ipstat
.ips_fragdropped
+=
1301 ipq
[i
].next
->ipq_nfrags
;
1302 ip_freef(ipq
[i
].next
);
1311 * Drain off all datagram fragments.
1318 for (i
= 0; i
< IPREASS_NHASH
; i
++) {
1319 while (ipq
[i
].next
!= &ipq
[i
]) {
1320 ipstat
.ips_fragdropped
+= ipq
[i
].next
->ipq_nfrags
;
1321 ip_freef(ipq
[i
].next
);
1328 * Do option processing on a datagram,
1329 * possibly discarding it if bad options are encountered,
1330 * or forwarding it if source-routed.
1331 * The pass argument is used when operating in the IPSTEALTH
1332 * mode to tell what options to process:
1333 * [LS]SRR (pass 0) or the others (pass 1).
1334 * The reason for as many as two passes is that when doing IPSTEALTH,
1335 * non-routing options should be processed only if the packet is for us.
1336 * Returns 1 if packet has been forwarded/freed,
1337 * 0 if the packet should be processed further.
1340 ip_dooptions(struct mbuf
*m
, int pass
, struct sockaddr_in
*next_hop
)
1342 struct sockaddr_in ipaddr
= { sizeof ipaddr
, AF_INET
};
1343 struct ip
*ip
= mtod(m
, struct ip
*);
1345 struct in_ifaddr
*ia
;
1346 int opt
, optlen
, cnt
, off
, code
, type
= ICMP_PARAMPROB
;
1347 boolean_t forward
= FALSE
;
1348 struct in_addr
*sin
, dst
;
1352 cp
= (u_char
*)(ip
+ 1);
1353 cnt
= (IP_VHL_HL(ip
->ip_vhl
) << 2) - sizeof(struct ip
);
1354 for (; cnt
> 0; cnt
-= optlen
, cp
+= optlen
) {
1355 opt
= cp
[IPOPT_OPTVAL
];
1356 if (opt
== IPOPT_EOL
)
1358 if (opt
== IPOPT_NOP
)
1361 if (cnt
< IPOPT_OLEN
+ sizeof(*cp
)) {
1362 code
= &cp
[IPOPT_OLEN
] - (u_char
*)ip
;
1365 optlen
= cp
[IPOPT_OLEN
];
1366 if (optlen
< IPOPT_OLEN
+ sizeof(*cp
) || optlen
> cnt
) {
1367 code
= &cp
[IPOPT_OLEN
] - (u_char
*)ip
;
1377 * Source routing with record.
1378 * Find interface with current destination address.
1379 * If none on this machine then drop if strictly routed,
1380 * or do nothing if loosely routed.
1381 * Record interface address and bring up next address
1382 * component. If strictly routed make sure next
1383 * address is on directly accessible net.
1387 if (ipstealth
&& pass
> 0)
1389 if (optlen
< IPOPT_OFFSET
+ sizeof(*cp
)) {
1390 code
= &cp
[IPOPT_OLEN
] - (u_char
*)ip
;
1393 if ((off
= cp
[IPOPT_OFFSET
]) < IPOPT_MINOFF
) {
1394 code
= &cp
[IPOPT_OFFSET
] - (u_char
*)ip
;
1397 ipaddr
.sin_addr
= ip
->ip_dst
;
1398 ia
= (struct in_ifaddr
*)
1399 ifa_ifwithaddr((struct sockaddr
*)&ipaddr
);
1401 if (opt
== IPOPT_SSRR
) {
1402 type
= ICMP_UNREACH
;
1403 code
= ICMP_UNREACH_SRCFAIL
;
1406 if (!ip_dosourceroute
)
1407 goto nosourcerouting
;
1409 * Loose routing, and not at next destination
1410 * yet; nothing to do except forward.
1414 off
--; /* 0 origin */
1415 if (off
> optlen
- (int)sizeof(struct in_addr
)) {
1417 * End of source route. Should be for us.
1419 if (!ip_acceptsourceroute
)
1420 goto nosourcerouting
;
1421 save_rte(m
, cp
, ip
->ip_src
);
1426 if (!ip_dosourceroute
) {
1428 char buf
[sizeof "aaa.bbb.ccc.ddd"];
1431 * Acting as a router, so generate ICMP
1434 strcpy(buf
, inet_ntoa(ip
->ip_dst
));
1436 "attempted source route from %s to %s\n",
1437 inet_ntoa(ip
->ip_src
), buf
);
1438 type
= ICMP_UNREACH
;
1439 code
= ICMP_UNREACH_SRCFAIL
;
1443 * Not acting as a router,
1447 ipstat
.ips_cantforward
++;
1454 * locate outgoing interface
1456 memcpy(&ipaddr
.sin_addr
, cp
+ off
,
1457 sizeof ipaddr
.sin_addr
);
1459 if (opt
== IPOPT_SSRR
) {
1460 #define INA struct in_ifaddr *
1461 #define SA struct sockaddr *
1462 if ((ia
= (INA
)ifa_ifwithdstaddr((SA
)&ipaddr
))
1464 ia
= (INA
)ifa_ifwithnet((SA
)&ipaddr
);
1466 ia
= ip_rtaddr(ipaddr
.sin_addr
, NULL
);
1469 type
= ICMP_UNREACH
;
1470 code
= ICMP_UNREACH_SRCFAIL
;
1473 ip
->ip_dst
= ipaddr
.sin_addr
;
1474 memcpy(cp
+ off
, &IA_SIN(ia
)->sin_addr
,
1475 sizeof(struct in_addr
));
1476 cp
[IPOPT_OFFSET
] += sizeof(struct in_addr
);
1478 * Let ip_intr's mcast routing check handle mcast pkts
1480 forward
= !IN_MULTICAST(ntohl(ip
->ip_dst
.s_addr
));
1484 if (ipstealth
&& pass
== 0)
1486 if (optlen
< IPOPT_OFFSET
+ sizeof(*cp
)) {
1487 code
= &cp
[IPOPT_OFFSET
] - (u_char
*)ip
;
1490 if ((off
= cp
[IPOPT_OFFSET
]) < IPOPT_MINOFF
) {
1491 code
= &cp
[IPOPT_OFFSET
] - (u_char
*)ip
;
1495 * If no space remains, ignore.
1497 off
--; /* 0 origin */
1498 if (off
> optlen
- (int)sizeof(struct in_addr
))
1500 memcpy(&ipaddr
.sin_addr
, &ip
->ip_dst
,
1501 sizeof ipaddr
.sin_addr
);
1503 * locate outgoing interface; if we're the destination,
1504 * use the incoming interface (should be same).
1506 if ((ia
= (INA
)ifa_ifwithaddr((SA
)&ipaddr
)) == NULL
&&
1507 (ia
= ip_rtaddr(ipaddr
.sin_addr
, NULL
)) == NULL
) {
1508 type
= ICMP_UNREACH
;
1509 code
= ICMP_UNREACH_HOST
;
1512 memcpy(cp
+ off
, &IA_SIN(ia
)->sin_addr
,
1513 sizeof(struct in_addr
));
1514 cp
[IPOPT_OFFSET
] += sizeof(struct in_addr
);
1518 if (ipstealth
&& pass
== 0)
1520 code
= cp
- (u_char
*)ip
;
1521 if (optlen
< 4 || optlen
> 40) {
1522 code
= &cp
[IPOPT_OLEN
] - (u_char
*)ip
;
1525 if ((off
= cp
[IPOPT_OFFSET
]) < 5) {
1526 code
= &cp
[IPOPT_OLEN
] - (u_char
*)ip
;
1529 if (off
> optlen
- (int)sizeof(int32_t)) {
1530 cp
[IPOPT_OFFSET
+ 1] += (1 << 4);
1531 if ((cp
[IPOPT_OFFSET
+ 1] & 0xf0) == 0) {
1532 code
= &cp
[IPOPT_OFFSET
] - (u_char
*)ip
;
1537 off
--; /* 0 origin */
1538 sin
= (struct in_addr
*)(cp
+ off
);
1539 switch (cp
[IPOPT_OFFSET
+ 1] & 0x0f) {
1541 case IPOPT_TS_TSONLY
:
1544 case IPOPT_TS_TSANDADDR
:
1545 if (off
+ sizeof(n_time
) +
1546 sizeof(struct in_addr
) > optlen
) {
1547 code
= &cp
[IPOPT_OFFSET
] - (u_char
*)ip
;
1550 ipaddr
.sin_addr
= dst
;
1551 ia
= (INA
)ifaof_ifpforaddr((SA
)&ipaddr
,
1555 memcpy(sin
, &IA_SIN(ia
)->sin_addr
,
1556 sizeof(struct in_addr
));
1557 cp
[IPOPT_OFFSET
] += sizeof(struct in_addr
);
1558 off
+= sizeof(struct in_addr
);
1561 case IPOPT_TS_PRESPEC
:
1562 if (off
+ sizeof(n_time
) +
1563 sizeof(struct in_addr
) > optlen
) {
1564 code
= &cp
[IPOPT_OFFSET
] - (u_char
*)ip
;
1567 memcpy(&ipaddr
.sin_addr
, sin
,
1568 sizeof(struct in_addr
));
1569 if (ifa_ifwithaddr((SA
)&ipaddr
) == NULL
)
1571 cp
[IPOPT_OFFSET
] += sizeof(struct in_addr
);
1572 off
+= sizeof(struct in_addr
);
1576 code
= &cp
[IPOPT_OFFSET
+ 1] - (u_char
*)ip
;
1580 memcpy(cp
+ off
, &ntime
, sizeof(n_time
));
1581 cp
[IPOPT_OFFSET
] += sizeof(n_time
);
1584 if (forward
&& ipforwarding
) {
1585 ip_forward(m
, TRUE
, next_hop
);
1590 icmp_error(m
, type
, code
, 0, 0);
1591 ipstat
.ips_badoptions
++;
1596 * Given address of next destination (final or next hop),
1597 * return internet address info of interface to be used to get there.
1600 ip_rtaddr(struct in_addr dst
, struct route
*ro0
)
1602 struct route sro
, *ro
;
1603 struct sockaddr_in
*sin
;
1604 struct in_ifaddr
*ia
;
1609 bzero(&sro
, sizeof(sro
));
1613 sin
= (struct sockaddr_in
*)&ro
->ro_dst
;
1615 if (ro
->ro_rt
== NULL
|| dst
.s_addr
!= sin
->sin_addr
.s_addr
) {
1616 if (ro
->ro_rt
!= NULL
) {
1620 sin
->sin_family
= AF_INET
;
1621 sin
->sin_len
= sizeof *sin
;
1622 sin
->sin_addr
= dst
;
1623 rtalloc_ign(ro
, RTF_PRCLONING
);
1626 if (ro
->ro_rt
== NULL
)
1629 ia
= ifatoia(ro
->ro_rt
->rt_ifa
);
1637 * Save incoming source route for use in replies,
1638 * to be picked up later by ip_srcroute if the receiver is interested.
1641 save_rte(struct mbuf
*m
, u_char
*option
, struct in_addr dst
)
1644 struct ip_srcrt_opt
*opt
;
1647 mtag
= m_tag_get(PACKET_TAG_IPSRCRT
, sizeof(*opt
), MB_DONTWAIT
);
1650 opt
= m_tag_data(mtag
);
1652 olen
= option
[IPOPT_OLEN
];
1655 kprintf("save_rte: olen %d\n", olen
);
1657 if (olen
> sizeof(opt
->ip_srcrt
) - (1 + sizeof(dst
))) {
1661 bcopy(option
, opt
->ip_srcrt
.srcopt
, olen
);
1662 opt
->ip_nhops
= (olen
- IPOPT_OFFSET
- 1) / sizeof(struct in_addr
);
1663 opt
->ip_srcrt
.dst
= dst
;
1664 m_tag_prepend(m
, mtag
);
1668 * Retrieve incoming source route for use in replies,
1669 * in the same form used by setsockopt.
1670 * The first hop is placed before the options, will be removed later.
1673 ip_srcroute(struct mbuf
*m0
)
1675 struct in_addr
*p
, *q
;
1678 struct ip_srcrt_opt
*opt
;
1683 mtag
= m_tag_find(m0
, PACKET_TAG_IPSRCRT
, NULL
);
1686 opt
= m_tag_data(mtag
);
1688 if (opt
->ip_nhops
== 0)
1690 m
= m_get(MB_DONTWAIT
, MT_HEADER
);
1694 #define OPTSIZ (sizeof(opt->ip_srcrt.nop) + sizeof(opt->ip_srcrt.srcopt))
1696 /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1697 m
->m_len
= opt
->ip_nhops
* sizeof(struct in_addr
) +
1698 sizeof(struct in_addr
) + OPTSIZ
;
1701 kprintf("ip_srcroute: nhops %d mlen %d",
1702 opt
->ip_nhops
, m
->m_len
);
1707 * First save first hop for return route
1709 p
= &opt
->ip_srcrt
.route
[opt
->ip_nhops
- 1];
1710 *(mtod(m
, struct in_addr
*)) = *p
--;
1713 kprintf(" hops %x", ntohl(mtod(m
, struct in_addr
*)->s_addr
));
1717 * Copy option fields and padding (nop) to mbuf.
1719 opt
->ip_srcrt
.nop
= IPOPT_NOP
;
1720 opt
->ip_srcrt
.srcopt
[IPOPT_OFFSET
] = IPOPT_MINOFF
;
1721 memcpy(mtod(m
, caddr_t
) + sizeof(struct in_addr
), &opt
->ip_srcrt
.nop
,
1723 q
= (struct in_addr
*)(mtod(m
, caddr_t
) +
1724 sizeof(struct in_addr
) + OPTSIZ
);
1727 * Record return path as an IP source route,
1728 * reversing the path (pointers are now aligned).
1730 while (p
>= opt
->ip_srcrt
.route
) {
1733 kprintf(" %x", ntohl(q
->s_addr
));
1738 * Last hop goes to final destination.
1740 *q
= opt
->ip_srcrt
.dst
;
1741 m_tag_delete(m0
, mtag
);
1744 kprintf(" %x\n", ntohl(q
->s_addr
));
1750 * Strip out IP options.
1753 ip_stripoptions(struct mbuf
*m
)
1756 struct ip
*ip
= mtod(m
, struct ip
*);
1760 optlen
= (IP_VHL_HL(ip
->ip_vhl
) << 2) - sizeof(struct ip
);
1761 opts
= (caddr_t
)(ip
+ 1);
1762 datalen
= m
->m_len
- (sizeof(struct ip
) + optlen
);
1763 bcopy(opts
+ optlen
, opts
, datalen
);
1765 if (m
->m_flags
& M_PKTHDR
)
1766 m
->m_pkthdr
.len
-= optlen
;
1767 ip
->ip_vhl
= IP_MAKE_VHL(IPVERSION
, sizeof(struct ip
) >> 2);
1770 u_char inetctlerrmap
[PRC_NCMDS
] = {
1772 0, EMSGSIZE
, EHOSTDOWN
, EHOSTUNREACH
,
1773 EHOSTUNREACH
, EHOSTUNREACH
, ECONNREFUSED
, ECONNREFUSED
,
1774 EMSGSIZE
, EHOSTUNREACH
, 0, 0,
1776 ENOPROTOOPT
, ECONNREFUSED
1780 * Forward a packet. If some error occurs return the sender
1781 * an icmp packet. Note we can't always generate a meaningful
1782 * icmp message because icmp doesn't have a large enough repertoire
1783 * of codes and types.
1785 * If not forwarding, just drop the packet. This could be confusing
1786 * if ipforwarding was zero but some routing protocol was advancing
1787 * us as a gateway to somewhere. However, we must let the routing
1788 * protocol deal with that.
1790 * The using_srcrt parameter indicates whether the packet is being forwarded
1791 * via a source route.
1794 ip_forward(struct mbuf
*m
, boolean_t using_srcrt
, struct sockaddr_in
*next_hop
)
1796 struct ip
*ip
= mtod(m
, struct ip
*);
1798 struct route fwd_ro
;
1799 int error
, type
= 0, code
= 0, destmtu
= 0;
1802 struct in_addr pkt_dst
;
1806 * Cache the destination address of the packet; this may be
1807 * changed by use of 'ipfw fwd'.
1809 pkt_dst
= (next_hop
!= NULL
) ? next_hop
->sin_addr
: ip
->ip_dst
;
1813 kprintf("forward: src %x dst %x ttl %x\n",
1814 ip
->ip_src
.s_addr
, pkt_dst
.s_addr
, ip
->ip_ttl
);
1817 if (m
->m_flags
& (M_BCAST
| M_MCAST
) || !in_canforward(pkt_dst
)) {
1818 ipstat
.ips_cantforward
++;
1822 if (!ipstealth
&& ip
->ip_ttl
<= IPTTLDEC
) {
1823 icmp_error(m
, ICMP_TIMXCEED
, ICMP_TIMXCEED_INTRANS
, dest
, 0);
1827 bzero(&fwd_ro
, sizeof(fwd_ro
));
1828 ip_rtaddr(pkt_dst
, &fwd_ro
);
1829 if (fwd_ro
.ro_rt
== NULL
) {
1830 icmp_error(m
, ICMP_UNREACH
, ICMP_UNREACH_HOST
, dest
, 0);
1836 * Save the IP header and at most 8 bytes of the payload,
1837 * in case we need to generate an ICMP message to the src.
1839 * XXX this can be optimized a lot by saving the data in a local
1840 * buffer on the stack (72 bytes at most), and only allocating the
1841 * mbuf if really necessary. The vast majority of the packets
1842 * are forwarded without having to send an ICMP back (either
1843 * because unnecessary, or because rate limited), so we are
1844 * really we are wasting a lot of work here.
1846 * We don't use m_copy() because it might return a reference
1847 * to a shared cluster. Both this function and ip_output()
1848 * assume exclusive access to the IP header in `m', so any
1849 * data in a cluster may change before we reach icmp_error().
1851 MGETHDR(mcopy
, MB_DONTWAIT
, m
->m_type
);
1852 if (mcopy
!= NULL
&& !m_dup_pkthdr(mcopy
, m
, MB_DONTWAIT
)) {
1854 * It's probably ok if the pkthdr dup fails (because
1855 * the deep copy of the tag chain failed), but for now
1856 * be conservative and just discard the copy since
1857 * code below may some day want the tags.
1862 if (mcopy
!= NULL
) {
1863 mcopy
->m_len
= imin((IP_VHL_HL(ip
->ip_vhl
) << 2) + 8,
1865 mcopy
->m_pkthdr
.len
= mcopy
->m_len
;
1866 m_copydata(m
, 0, mcopy
->m_len
, mtod(mcopy
, caddr_t
));
1870 ip
->ip_ttl
-= IPTTLDEC
;
1873 * If forwarding packet using same interface that it came in on,
1874 * perhaps should send a redirect to sender to shortcut a hop.
1875 * Only send redirect if source is sending directly to us,
1876 * and if packet was not source routed (or has any options).
1877 * Also, don't send redirect if forwarding using a default route
1878 * or a route modified by a redirect.
1880 if (rt
->rt_ifp
== m
->m_pkthdr
.rcvif
&&
1881 !(rt
->rt_flags
& (RTF_DYNAMIC
| RTF_MODIFIED
)) &&
1882 satosin(rt_key(rt
))->sin_addr
.s_addr
!= INADDR_ANY
&&
1883 ipsendredirects
&& !using_srcrt
&& next_hop
== NULL
) {
1884 u_long src
= ntohl(ip
->ip_src
.s_addr
);
1885 struct in_ifaddr
*rt_ifa
= (struct in_ifaddr
*)rt
->rt_ifa
;
1887 if (rt_ifa
!= NULL
&&
1888 (src
& rt_ifa
->ia_subnetmask
) == rt_ifa
->ia_subnet
) {
1889 if (rt
->rt_flags
& RTF_GATEWAY
)
1890 dest
= satosin(rt
->rt_gateway
)->sin_addr
.s_addr
;
1892 dest
= pkt_dst
.s_addr
;
1894 * Router requirements says to only send
1897 type
= ICMP_REDIRECT
;
1898 code
= ICMP_REDIRECT_HOST
;
1901 kprintf("redirect (%d) to %x\n", code
, dest
);
1906 error
= ip_output(m
, NULL
, &fwd_ro
, IP_FORWARDING
, NULL
, NULL
);
1908 ipstat
.ips_forward
++;
1911 ipflow_create(&fwd_ro
, mcopy
);
1916 ipstat
.ips_redirectsent
++;
1919 ipstat
.ips_cantforward
++;
1926 * Send ICMP message.
1931 case 0: /* forwarded, but need redirect */
1932 /* type, code set above */
1935 case ENETUNREACH
: /* shouldn't happen, checked above */
1940 type
= ICMP_UNREACH
;
1941 code
= ICMP_UNREACH_HOST
;
1945 type
= ICMP_UNREACH
;
1946 code
= ICMP_UNREACH_NEEDFRAG
;
1949 * If the packet is routed over IPsec tunnel, tell the
1950 * originator the tunnel MTU.
1951 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
1954 if (fwd_ro
.ro_rt
!= NULL
) {
1955 struct secpolicy
*sp
= NULL
;
1960 sp
= ipsec4_getpolicybyaddr(mcopy
,
1966 destmtu
= fwd_ro
.ro_rt
->rt_ifp
->if_mtu
;
1968 /* count IPsec header size */
1969 ipsechdr
= ipsec4_hdrsiz(mcopy
,
1974 * find the correct route for outer IPv4
1975 * header, compute tunnel MTU.
1978 if (sp
->req
!= NULL
&& sp
->req
->sav
!= NULL
&&
1979 sp
->req
->sav
->sah
!= NULL
) {
1980 ro
= &sp
->req
->sav
->sah
->sa_route
;
1981 if (ro
->ro_rt
!= NULL
&&
1982 ro
->ro_rt
->rt_ifp
!= NULL
) {
1984 ro
->ro_rt
->rt_ifp
->if_mtu
;
1985 destmtu
-= ipsechdr
;
1994 * If the packet is routed over IPsec tunnel, tell the
1995 * originator the tunnel MTU.
1996 * tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
1999 if (fwd_ro
.ro_rt
!= NULL
) {
2000 struct secpolicy
*sp
= NULL
;
2005 sp
= ipsec_getpolicybyaddr(mcopy
,
2011 destmtu
= fwd_ro
.ro_rt
->rt_ifp
->if_mtu
;
2013 /* count IPsec header size */
2014 ipsechdr
= ipsec4_hdrsiz(mcopy
,
2019 * find the correct route for outer IPv4
2020 * header, compute tunnel MTU.
2023 if (sp
->req
!= NULL
&&
2024 sp
->req
->sav
!= NULL
&&
2025 sp
->req
->sav
->sah
!= NULL
) {
2026 ro
= &sp
->req
->sav
->sah
->sa_route
;
2027 if (ro
->ro_rt
!= NULL
&&
2028 ro
->ro_rt
->rt_ifp
!= NULL
) {
2030 ro
->ro_rt
->rt_ifp
->if_mtu
;
2031 destmtu
-= ipsechdr
;
2038 #else /* !IPSEC && !FAST_IPSEC */
2039 if (fwd_ro
.ro_rt
!= NULL
)
2040 destmtu
= fwd_ro
.ro_rt
->rt_ifp
->if_mtu
;
2042 ipstat
.ips_cantfrag
++;
2047 * A router should not generate ICMP_SOURCEQUENCH as
2048 * required in RFC1812 Requirements for IP Version 4 Routers.
2049 * Source quench could be a big problem under DoS attacks,
2050 * or if the underlying interface is rate-limited.
2051 * Those who need source quench packets may re-enable them
2052 * via the net.inet.ip.sendsourcequench sysctl.
2054 if (!ip_sendsourcequench
) {
2058 type
= ICMP_SOURCEQUENCH
;
2063 case EACCES
: /* ipfw denied packet */
2067 icmp_error(mcopy
, type
, code
, dest
, destmtu
);
2069 if (fwd_ro
.ro_rt
!= NULL
)
2070 RTFREE(fwd_ro
.ro_rt
);
2074 ip_savecontrol(struct inpcb
*inp
, struct mbuf
**mp
, struct ip
*ip
,
2077 if (inp
->inp_socket
->so_options
& SO_TIMESTAMP
) {
2081 *mp
= sbcreatecontrol((caddr_t
) &tv
, sizeof(tv
),
2082 SCM_TIMESTAMP
, SOL_SOCKET
);
2084 mp
= &(*mp
)->m_next
;
2086 if (inp
->inp_flags
& INP_RECVDSTADDR
) {
2087 *mp
= sbcreatecontrol((caddr_t
) &ip
->ip_dst
,
2088 sizeof(struct in_addr
), IP_RECVDSTADDR
, IPPROTO_IP
);
2090 mp
= &(*mp
)->m_next
;
2092 if (inp
->inp_flags
& INP_RECVTTL
) {
2093 *mp
= sbcreatecontrol((caddr_t
) &ip
->ip_ttl
,
2094 sizeof(u_char
), IP_RECVTTL
, IPPROTO_IP
);
2096 mp
= &(*mp
)->m_next
;
2100 * Moving these out of udp_input() made them even more broken
2101 * than they already were.
2103 /* options were tossed already */
2104 if (inp
->inp_flags
& INP_RECVOPTS
) {
2105 *mp
= sbcreatecontrol((caddr_t
) opts_deleted_above
,
2106 sizeof(struct in_addr
), IP_RECVOPTS
, IPPROTO_IP
);
2108 mp
= &(*mp
)->m_next
;
2110 /* ip_srcroute doesn't do what we want here, need to fix */
2111 if (inp
->inp_flags
& INP_RECVRETOPTS
) {
2112 *mp
= sbcreatecontrol((caddr_t
) ip_srcroute(m
),
2113 sizeof(struct in_addr
), IP_RECVRETOPTS
, IPPROTO_IP
);
2115 mp
= &(*mp
)->m_next
;
2118 if (inp
->inp_flags
& INP_RECVIF
) {
2121 struct sockaddr_dl sdl
;
2124 struct sockaddr_dl
*sdp
;
2125 struct sockaddr_dl
*sdl2
= &sdlbuf
.sdl
;
2127 if (((ifp
= m
->m_pkthdr
.rcvif
)) &&
2128 ((ifp
->if_index
!= 0) && (ifp
->if_index
<= if_index
))) {
2129 sdp
= IF_LLSOCKADDR(ifp
);
2131 * Change our mind and don't try copy.
2133 if ((sdp
->sdl_family
!= AF_LINK
) ||
2134 (sdp
->sdl_len
> sizeof(sdlbuf
))) {
2137 bcopy(sdp
, sdl2
, sdp
->sdl_len
);
2141 offsetof(struct sockaddr_dl
, sdl_data
[0]);
2142 sdl2
->sdl_family
= AF_LINK
;
2143 sdl2
->sdl_index
= 0;
2144 sdl2
->sdl_nlen
= sdl2
->sdl_alen
= sdl2
->sdl_slen
= 0;
2146 *mp
= sbcreatecontrol((caddr_t
) sdl2
, sdl2
->sdl_len
,
2147 IP_RECVIF
, IPPROTO_IP
);
2149 mp
= &(*mp
)->m_next
;
2154 * XXX these routines are called from the upper part of the kernel.
2156 * They could also be moved to ip_mroute.c, since all the RSVP
2157 * handling is done there already.
2160 ip_rsvp_init(struct socket
*so
)
2162 if (so
->so_type
!= SOCK_RAW
||
2163 so
->so_proto
->pr_protocol
!= IPPROTO_RSVP
)
2166 if (ip_rsvpd
!= NULL
)
2171 * This may seem silly, but we need to be sure we don't over-increment
2172 * the RSVP counter, in case something slips up.
2187 * This may seem silly, but we need to be sure we don't over-decrement
2188 * the RSVP counter, in case something slips up.
2198 rsvp_input(struct mbuf
*m
, ...) /* XXX must fixup manually */
2204 off
= __va_arg(ap
, int);
2205 proto
= __va_arg(ap
, int);
2208 if (rsvp_input_p
) { /* call the real one if loaded */
2209 rsvp_input_p(m
, off
, proto
);
2213 /* Can still get packets with rsvp_on = 0 if there is a local member
2214 * of the group to which the RSVP packet is addressed. But in this
2215 * case we want to throw the packet away.
2223 if (ip_rsvpd
!= NULL
) {
2224 rip_input(m
, off
, proto
);
2227 /* Drop the packet */