2 * Copyright (c) 1982, 1986, 1988, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * @(#)ip_icmp.c 8.2 (Berkeley) 1/4/94
34 * $FreeBSD: src/sys/netinet/ip_icmp.c,v 1.39.2.19 2003/01/24 05:11:34 sam Exp $
35 * $DragonFly: src/sys/netinet/ip_icmp.c,v 1.32 2008/10/27 02:56:30 sephe Exp $
38 #include "opt_ipsec.h"
40 #include <sys/param.h>
41 #include <sys/systm.h>
43 #include <sys/protosw.h>
44 #include <sys/socket.h>
45 #include <sys/socketops.h>
47 #include <sys/kernel.h>
48 #include <sys/sysctl.h>
49 #include <sys/in_cksum.h>
51 #include <machine/stdarg.h>
54 #include <net/if_types.h>
55 #include <net/route.h>
58 #include <netinet/in.h>
59 #include <netinet/in_systm.h>
60 #include <netinet/in_var.h>
61 #include <netinet/ip.h>
62 #include <netinet/ip_icmp.h>
63 #include <netinet/ip_var.h>
64 #include <netinet/icmp_var.h>
67 #include <netinet6/ipsec.h>
68 #include <netproto/key/key.h>
72 #include <netproto/ipsec/ipsec.h>
73 #include <netproto/ipsec/key.h>
78 * ICMP routines: error generation, receive packet processing, and
79 * routines to turnaround packets back to the originator, and
80 * host table maintenance routines.
83 struct icmpstat icmpstat
;
84 SYSCTL_STRUCT(_net_inet_icmp
, ICMPCTL_STATS
, stats
, CTLFLAG_RW
,
85 &icmpstat
, icmpstat
, "");
87 static int icmpmaskrepl
= 0;
88 SYSCTL_INT(_net_inet_icmp
, ICMPCTL_MASKREPL
, maskrepl
, CTLFLAG_RW
,
89 &icmpmaskrepl
, 0, "");
91 static int drop_redirect
= 0;
92 SYSCTL_INT(_net_inet_icmp
, OID_AUTO
, drop_redirect
, CTLFLAG_RW
,
93 &drop_redirect
, 0, "");
95 static int log_redirect
= 0;
96 SYSCTL_INT(_net_inet_icmp
, OID_AUTO
, log_redirect
, CTLFLAG_RW
,
97 &log_redirect
, 0, "");
102 * ICMP error-response bandwidth limiting sysctl. If not enabled, sysctl
103 * variable content is -1 and read-only.
106 static int icmplim
= 200;
107 SYSCTL_INT(_net_inet_icmp
, ICMPCTL_ICMPLIM
, icmplim
, CTLFLAG_RW
,
111 static int icmplim
= -1;
112 SYSCTL_INT(_net_inet_icmp
, ICMPCTL_ICMPLIM
, icmplim
, CTLFLAG_RD
,
117 static int icmplim_output
= 1;
118 SYSCTL_INT(_net_inet_icmp
, OID_AUTO
, icmplim_output
, CTLFLAG_RW
,
119 &icmplim_output
, 0, "");
122 * ICMP broadcast echo sysctl
125 static int icmpbmcastecho
= 0;
126 SYSCTL_INT(_net_inet_icmp
, OID_AUTO
, bmcastecho
, CTLFLAG_RW
,
127 &icmpbmcastecho
, 0, "");
134 static void icmp_reflect (struct mbuf
*);
135 static void icmp_send (struct mbuf
*, struct mbuf
*, struct route
*);
137 extern struct protosw inetsw
[];
140 * Generate an error packet of type error
141 * in response to bad packet ip.
144 icmp_error(struct mbuf
*n
, int type
, int code
, n_long dest
, int destmtu
)
146 struct ip
*oip
= mtod(n
, struct ip
*), *nip
;
147 unsigned oiplen
= IP_VHL_HL(oip
->ip_vhl
) << 2;
154 kprintf("icmp_error(%p, %d, %d)\n", oip
, type
, code
);
156 if (type
!= ICMP_REDIRECT
)
157 icmpstat
.icps_error
++;
159 * Don't send error if the original packet was encrypted.
160 * Don't send error if not the first fragment of message.
161 * Don't error if the old packet protocol was ICMP
162 * error message, only known informational types.
164 if (n
->m_flags
& M_DECRYPTED
)
166 if (oip
->ip_off
&~ (IP_MF
|IP_DF
))
168 if (oip
->ip_p
== IPPROTO_ICMP
&& type
!= ICMP_REDIRECT
&&
169 n
->m_len
>= oiplen
+ ICMP_MINLEN
&&
170 !ICMP_INFOTYPE(((struct icmp
*)((caddr_t
)oip
+ oiplen
))->icmp_type
)) {
171 icmpstat
.icps_oldicmp
++;
174 /* Don't send error in response to a multicast or broadcast packet */
175 if (n
->m_flags
& (M_BCAST
|M_MCAST
))
178 * First, formulate icmp message
180 m
= m_gethdr(MB_DONTWAIT
, MT_HEADER
);
183 icmplen
= min(oiplen
+ 8, oip
->ip_len
);
184 if (icmplen
< sizeof(struct ip
))
185 panic("icmp_error: bad length");
186 m
->m_len
= icmplen
+ ICMP_MINLEN
;
187 MH_ALIGN(m
, m
->m_len
);
188 icp
= mtod(m
, struct icmp
*);
189 if ((u_int
)type
> ICMP_MAXTYPE
)
191 icmpstat
.icps_outhist
[type
]++;
192 icp
->icmp_type
= type
;
193 if (type
== ICMP_REDIRECT
)
194 icp
->icmp_gwaddr
.s_addr
= dest
;
198 * The following assignments assume an overlay with the
199 * zeroed icmp_void field.
201 if (type
== ICMP_PARAMPROB
) {
202 icp
->icmp_pptr
= code
;
204 } else if (type
== ICMP_UNREACH
&&
205 code
== ICMP_UNREACH_NEEDFRAG
&& destmtu
) {
206 icp
->icmp_nextmtu
= htons(destmtu
);
210 icp
->icmp_code
= code
;
211 m_copydata(n
, 0, icmplen
, (caddr_t
)&icp
->icmp_ip
);
215 * Convert fields to network representation.
217 nip
->ip_len
= htons(nip
->ip_len
);
218 nip
->ip_off
= htons(nip
->ip_off
);
221 * Now, copy old ip header (without options)
222 * in front of icmp message.
224 if (m
->m_data
- sizeof(struct ip
) < m
->m_pktdat
)
226 m
->m_data
-= sizeof(struct ip
);
227 m
->m_len
+= sizeof(struct ip
);
228 m
->m_pkthdr
.len
= m
->m_len
;
229 m
->m_pkthdr
.rcvif
= n
->m_pkthdr
.rcvif
;
230 nip
= mtod(m
, struct ip
*);
231 bcopy(oip
, nip
, sizeof(struct ip
));
232 nip
->ip_len
= m
->m_len
;
233 nip
->ip_vhl
= IP_VHL_BORING
;
234 nip
->ip_p
= IPPROTO_ICMP
;
236 m
->m_pkthdr
.fw_flags
|= n
->m_pkthdr
.fw_flags
& FW_MBUF_GENERATED
;
244 * Process a received ICMP message.
247 icmp_input(struct mbuf
*m
, ...)
249 struct sockaddr_in icmpsrc
= { sizeof(struct sockaddr_in
), AF_INET
};
250 struct sockaddr_in icmpdst
= { sizeof(struct sockaddr_in
), AF_INET
};
251 struct sockaddr_in icmpgw
= { sizeof(struct sockaddr_in
), AF_INET
};
253 struct in_ifaddr
*ia
;
254 struct ip
*ip
= mtod(m
, struct ip
*);
255 int icmplen
= ip
->ip_len
;
257 int code
, off
, proto
;
261 off
= __va_arg(ap
, int);
262 proto
= __va_arg(ap
, int);
268 * Locate icmp structure in mbuf, and check
269 * that not corrupted and of at least minimum length.
273 char buf
[sizeof "aaa.bbb.ccc.ddd"];
275 strcpy(buf
, inet_ntoa(ip
->ip_src
));
276 kprintf("icmp_input from %s to %s, len %d\n",
277 buf
, inet_ntoa(ip
->ip_dst
), icmplen
);
280 if (icmplen
< ICMP_MINLEN
) {
281 icmpstat
.icps_tooshort
++;
284 i
= hlen
+ min(icmplen
, ICMP_ADVLENMIN
);
285 if (m
->m_len
< i
&& (m
= m_pullup(m
, i
)) == 0) {
286 icmpstat
.icps_tooshort
++;
289 ip
= mtod(m
, struct ip
*);
292 icp
= mtod(m
, struct icmp
*);
293 if (in_cksum(m
, icmplen
)) {
294 icmpstat
.icps_checksum
++;
300 if (m
->m_pkthdr
.rcvif
&& m
->m_pkthdr
.rcvif
->if_type
== IFT_FAITH
) {
302 * Deliver very specific ICMP type only.
304 switch (icp
->icmp_type
) {
315 kprintf("icmp_input, type %d code %d\n", icp
->icmp_type
,
320 * Message type specific processing.
322 if (icp
->icmp_type
> ICMP_MAXTYPE
)
324 icmpstat
.icps_inhist
[icp
->icmp_type
]++;
325 code
= icp
->icmp_code
;
326 switch (icp
->icmp_type
) {
330 case ICMP_UNREACH_NET
:
331 case ICMP_UNREACH_HOST
:
332 case ICMP_UNREACH_SRCFAIL
:
333 case ICMP_UNREACH_NET_UNKNOWN
:
334 case ICMP_UNREACH_HOST_UNKNOWN
:
335 case ICMP_UNREACH_ISOLATED
:
336 case ICMP_UNREACH_TOSNET
:
337 case ICMP_UNREACH_TOSHOST
:
338 case ICMP_UNREACH_HOST_PRECEDENCE
:
339 case ICMP_UNREACH_PRECEDENCE_CUTOFF
:
340 code
= PRC_UNREACH_NET
;
343 case ICMP_UNREACH_NEEDFRAG
:
348 * RFC 1122, Sections 3.2.2.1 and 4.2.3.9.
349 * Treat subcodes 2,3 as immediate RST
351 case ICMP_UNREACH_PROTOCOL
:
352 case ICMP_UNREACH_PORT
:
353 code
= PRC_UNREACH_PORT
;
356 case ICMP_UNREACH_NET_PROHIB
:
357 case ICMP_UNREACH_HOST_PROHIB
:
358 case ICMP_UNREACH_FILTER_PROHIB
:
359 code
= PRC_UNREACH_ADMIN_PROHIB
;
370 code
+= PRC_TIMXCEED_INTRANS
;
376 code
= PRC_PARAMPROB
;
379 case ICMP_SOURCEQUENCH
:
385 * Problem with datagram; advise higher level routines.
387 if (icmplen
< ICMP_ADVLENMIN
|| icmplen
< ICMP_ADVLEN(icp
) ||
388 IP_VHL_HL(icp
->icmp_ip
.ip_vhl
) < (sizeof(struct ip
) >> 2)) {
389 icmpstat
.icps_badlen
++;
392 icp
->icmp_ip
.ip_len
= ntohs(icp
->icmp_ip
.ip_len
);
393 /* Discard ICMP's in response to multicast packets */
394 if (IN_MULTICAST(ntohl(icp
->icmp_ip
.ip_dst
.s_addr
)))
398 kprintf("deliver to protocol %d\n", icp
->icmp_ip
.ip_p
);
400 icmpsrc
.sin_addr
= icp
->icmp_ip
.ip_dst
;
404 * If we got a needfrag and there is a host route to the
405 * original destination, and the MTU is not locked, then
406 * set the MTU in the route to the suggested new value
407 * (if given) and then notify as usual. The ULPs will
408 * notice that the MTU has changed and adapt accordingly.
409 * If no new MTU was suggested, then we guess a new one
410 * less than the current value. If the new MTU is
411 * unreasonably small (arbitrarily set at 296), then
412 * we reset the MTU to the interface value and enable the
413 * lock bit, indicating that we are no longer doing MTU
416 if (code
== PRC_MSGSIZE
) {
420 rt
= rtpurelookup((struct sockaddr
*)&icmpsrc
);
421 if (rt
!= NULL
&& (rt
->rt_flags
& RTF_HOST
) &&
422 !(rt
->rt_rmx
.rmx_locks
& RTV_MTU
)) {
423 mtu
= ntohs(icp
->icmp_nextmtu
);
425 mtu
= ip_next_mtu(rt
->rt_rmx
.rmx_mtu
,
428 kprintf("MTU for %s reduced to %d\n",
429 inet_ntoa(icmpsrc
.sin_addr
), mtu
);
432 /* rt->rt_rmx.rmx_mtu =
433 rt->rt_ifp->if_mtu; */
434 rt
->rt_rmx
.rmx_locks
|= RTV_MTU
;
435 } else if (rt
->rt_rmx
.rmx_mtu
> mtu
) {
436 rt
->rt_rmx
.rmx_mtu
= mtu
;
444 * XXX if the packet contains [IPv4 AH TCP], we can't make a
445 * notification to TCP layer.
448 &inetsw
[ip_protox
[icp
->icmp_ip
.ip_p
]],
449 code
, (struct sockaddr
*)&icmpsrc
, &icp
->icmp_ip
);
453 icmpstat
.icps_badcode
++;
458 && (m
->m_flags
& (M_MCAST
| M_BCAST
)) != 0) {
459 icmpstat
.icps_bmcastecho
++;
462 icp
->icmp_type
= ICMP_ECHOREPLY
;
464 if (badport_bandlim(BANDLIM_ICMP_ECHO
) < 0)
472 && (m
->m_flags
& (M_MCAST
| M_BCAST
)) != 0) {
473 icmpstat
.icps_bmcasttstamp
++;
476 if (icmplen
< ICMP_TSLEN
) {
477 icmpstat
.icps_badlen
++;
480 icp
->icmp_type
= ICMP_TSTAMPREPLY
;
481 icp
->icmp_rtime
= iptime();
482 icp
->icmp_ttime
= icp
->icmp_rtime
; /* bogus, do later! */
484 if (badport_bandlim(BANDLIM_ICMP_TSTAMP
) < 0)
491 if (icmpmaskrepl
== 0)
494 * We are not able to respond with all ones broadcast
495 * unless we receive it over a point-to-point interface.
497 if (icmplen
< ICMP_MASKLEN
)
499 switch (ip
->ip_dst
.s_addr
) {
501 case INADDR_BROADCAST
:
503 icmpdst
.sin_addr
= ip
->ip_src
;
507 icmpdst
.sin_addr
= ip
->ip_dst
;
509 ia
= (struct in_ifaddr
*)ifaof_ifpforaddr(
510 (struct sockaddr
*)&icmpdst
, m
->m_pkthdr
.rcvif
);
515 icp
->icmp_type
= ICMP_MASKREPLY
;
516 icp
->icmp_mask
= ia
->ia_sockmask
.sin_addr
.s_addr
;
517 if (ip
->ip_src
.s_addr
== 0) {
518 if (ia
->ia_ifp
->if_flags
& IFF_BROADCAST
)
519 ip
->ip_src
= satosin(&ia
->ia_broadaddr
)->sin_addr
;
520 else if (ia
->ia_ifp
->if_flags
& IFF_POINTOPOINT
)
521 ip
->ip_src
= satosin(&ia
->ia_dstaddr
)->sin_addr
;
524 ip
->ip_len
+= hlen
; /* since ip_input deducts this */
525 icmpstat
.icps_reflect
++;
526 icmpstat
.icps_outhist
[icp
->icmp_type
]++;
534 src
= ntohl(ip
->ip_src
.s_addr
);
535 dst
= ntohl(icp
->icmp_ip
.ip_dst
.s_addr
);
536 gw
= ntohl(icp
->icmp_gwaddr
.s_addr
);
537 kprintf("icmp redirect from %d.%d.%d.%d: "
538 "%d.%d.%d.%d => %d.%d.%d.%d\n",
539 (int)(src
>> 24), (int)((src
>> 16) & 0xff),
540 (int)((src
>> 8) & 0xff), (int)(src
& 0xff),
541 (int)(dst
>> 24), (int)((dst
>> 16) & 0xff),
542 (int)((dst
>> 8) & 0xff), (int)(dst
& 0xff),
543 (int)(gw
>> 24), (int)((gw
>> 16) & 0xff),
544 (int)((gw
>> 8) & 0xff), (int)(gw
& 0xff));
550 if (icmplen
< ICMP_ADVLENMIN
|| icmplen
< ICMP_ADVLEN(icp
) ||
551 IP_VHL_HL(icp
->icmp_ip
.ip_vhl
) < (sizeof(struct ip
) >> 2)) {
552 icmpstat
.icps_badlen
++;
556 * Short circuit routing redirects to force
557 * immediate change in the kernel's routing
558 * tables. The message is also handed to anyone
559 * listening on a raw socket (e.g. the routing
560 * daemon for use in updating its tables).
562 icmpgw
.sin_addr
= ip
->ip_src
;
563 icmpdst
.sin_addr
= icp
->icmp_gwaddr
;
566 char buf
[sizeof "aaa.bbb.ccc.ddd"];
568 strcpy(buf
, inet_ntoa(icp
->icmp_ip
.ip_dst
));
569 kprintf("redirect dst %s to %s\n",
570 buf
, inet_ntoa(icp
->icmp_gwaddr
));
573 icmpsrc
.sin_addr
= icp
->icmp_ip
.ip_dst
;
574 rtredirect((struct sockaddr
*)&icmpsrc
,
575 (struct sockaddr
*)&icmpdst
,
576 (struct sockaddr
*)0, RTF_GATEWAY
| RTF_HOST
,
577 (struct sockaddr
*)&icmpgw
);
578 kpfctlinput(PRC_REDIRECT_HOST
, (struct sockaddr
*)&icmpsrc
);
580 key_sa_routechange((struct sockaddr
*)&icmpsrc
);
585 * No kernel processing for the following;
586 * just fall through to send to raw listener.
589 case ICMP_ROUTERADVERT
:
590 case ICMP_ROUTERSOLICIT
:
591 case ICMP_TSTAMPREPLY
:
599 rip_input(m
, off
, proto
);
607 * Reflect the ip packet back to the source
610 icmp_reflect(struct mbuf
*m
)
612 struct ip
*ip
= mtod(m
, struct ip
*);
613 struct in_ifaddr
*ia
;
614 struct in_ifaddr_container
*iac
;
616 struct mbuf
*opts
= 0;
617 int optlen
= (IP_VHL_HL(ip
->ip_vhl
) << 2) - sizeof(struct ip
);
618 struct route
*ro
= NULL
, rt
;
620 if (!in_canforward(ip
->ip_src
) &&
621 ((ntohl(ip
->ip_src
.s_addr
) & IN_CLASSA_NET
) !=
622 (IN_LOOPBACKNET
<< IN_CLASSA_NSHIFT
))) {
623 m_freem(m
); /* Bad return address */
624 icmpstat
.icps_badaddr
++;
625 goto done
; /* Ip_output() will check for broadcast */
628 ip
->ip_dst
= ip
->ip_src
;
630 bzero(ro
, sizeof *ro
);
632 * If the incoming packet was addressed directly to us,
633 * use dst as the src for the reply. Otherwise (broadcast
634 * or anonymous), use the address which corresponds
635 * to the incoming interface.
638 LIST_FOREACH(iac
, INADDR_HASH(t
.s_addr
), ia_hash
) {
639 if (t
.s_addr
== IA_SIN(iac
->ia
)->sin_addr
.s_addr
) {
644 if (m
->m_pkthdr
.rcvif
!= NULL
&&
645 m
->m_pkthdr
.rcvif
->if_flags
& IFF_BROADCAST
) {
646 struct ifaddr_container
*ifac
;
648 TAILQ_FOREACH(ifac
, &m
->m_pkthdr
.rcvif
->if_addrheads
[mycpuid
],
650 struct ifaddr
*ifa
= ifac
->ifa
;
652 if (ifa
->ifa_addr
->sa_family
!= AF_INET
)
655 if (satosin(&ia
->ia_broadaddr
)->sin_addr
.s_addr
==
660 ia
= ip_rtaddr(ip
->ip_dst
, ro
);
661 /* We need a route to do anything useful. */
664 icmpstat
.icps_noroute
++;
668 t
= IA_SIN(ia
)->sin_addr
;
670 ip
->ip_ttl
= ip_defttl
;
678 * Retrieve any source routing from the incoming packet;
679 * add on any record-route or timestamp options.
681 cp
= (u_char
*) (ip
+ 1);
682 if ((opts
= ip_srcroute(m
)) == 0 &&
683 (opts
= m_gethdr(MB_DONTWAIT
, MT_HEADER
))) {
684 opts
->m_len
= sizeof(struct in_addr
);
685 mtod(opts
, struct in_addr
*)->s_addr
= 0;
690 kprintf("icmp_reflect optlen %d rt %d => ",
691 optlen
, opts
->m_len
);
693 for (cnt
= optlen
; cnt
> 0; cnt
-= len
, cp
+= len
) {
694 opt
= cp
[IPOPT_OPTVAL
];
695 if (opt
== IPOPT_EOL
)
697 if (opt
== IPOPT_NOP
)
700 if (cnt
< IPOPT_OLEN
+ sizeof *cp
)
702 len
= cp
[IPOPT_OLEN
];
703 if (len
< IPOPT_OLEN
+ sizeof *cp
||
708 * Should check for overflow, but it
711 if (opt
== IPOPT_RR
|| opt
== IPOPT_TS
||
712 opt
== IPOPT_SECURITY
) {
714 mtod(opts
, caddr_t
) + opts
->m_len
,
719 /* Terminate & pad, if necessary */
720 cnt
= opts
->m_len
% 4;
722 for (; cnt
< 4; cnt
++) {
723 *(mtod(opts
, caddr_t
) + opts
->m_len
) =
730 kprintf("%d\n", opts
->m_len
);
734 * Now strip out original options by copying rest of first
735 * mbuf's data back, and adjust the IP length.
737 ip
->ip_len
-= optlen
;
738 ip
->ip_vhl
= IP_VHL_BORING
;
740 if (m
->m_flags
& M_PKTHDR
)
741 m
->m_pkthdr
.len
-= optlen
;
742 optlen
+= sizeof(struct ip
);
743 bcopy((caddr_t
)ip
+ optlen
, ip
+ 1,
744 m
->m_len
- sizeof(struct ip
));
746 m
->m_pkthdr
.fw_flags
&= FW_MBUF_GENERATED
;
747 m
->m_flags
&= ~(M_BCAST
|M_MCAST
);
748 icmp_send(m
, opts
, ro
);
757 * Send an icmp packet back to the ip level,
758 * after supplying a checksum.
761 icmp_send(struct mbuf
*m
, struct mbuf
*opts
, struct route
*rt
)
763 struct ip
*ip
= mtod(m
, struct ip
*);
767 hlen
= IP_VHL_HL(ip
->ip_vhl
) << 2;
770 icp
= mtod(m
, struct icmp
*);
772 icp
->icmp_cksum
= in_cksum(m
, ip
->ip_len
- hlen
);
775 m
->m_pkthdr
.rcvif
= (struct ifnet
*)0;
778 char buf
[sizeof "aaa.bbb.ccc.ddd"];
780 strcpy(buf
, inet_ntoa(ip
->ip_dst
));
781 kprintf("icmp_send dst %s src %s\n", buf
, inet_ntoa(ip
->ip_src
));
784 ip_output(m
, opts
, rt
, 0, NULL
, NULL
);
794 t
= (atv
.tv_sec
% (24*60*60)) * 1000 + atv
.tv_usec
/ 1000;
800 * Return the next larger or smaller MTU plateau (table from RFC 1191)
801 * given current value MTU. If DIR is less than zero, a larger plateau
802 * is returned; otherwise, a smaller value is returned.
805 ip_next_mtu(int mtu
, int dir
)
807 static int mtutab
[] = {
808 65535, 32000, 17914, 8166, 4352, 2002, 1492, 1006, 508, 296,
813 for (i
= 0; i
< (sizeof mtutab
) / (sizeof mtutab
[0]); i
++) {
814 if (mtu
>= mtutab
[i
])
822 return mtutab
[i
- 1];
825 if (mtutab
[i
] == 0) {
827 } else if(mtu
> mtutab
[i
]) {
830 return mtutab
[i
+ 1];
838 * badport_bandlim() - check for ICMP bandwidth limit
840 * Return 0 if it is ok to send an ICMP error response, -1 if we have
841 * hit our bandwidth limit and it is not ok.
843 * If icmplim is <= 0, the feature is disabled and 0 is returned.
845 * For now we separate the TCP and UDP subsystems w/ different 'which'
846 * values. We may eventually remove this separation (and simplify the
849 * Note that the printing of the error message is delayed so we can
850 * properly print the icmp error rate that the system was trying to do
851 * (i.e. 22000/100 pps, etc...). This can cause long delays in printing
852 * the 'final' error, but it doesn't make sense to solve the printing
853 * delay with more complex code.
856 badport_bandlim(int which
)
858 static int lticks
[BANDLIM_MAX
+ 1];
859 static int lpackets
[BANDLIM_MAX
+ 1];
861 const char *bandlimittype
[] = {
862 "Limiting icmp unreach response",
863 "Limiting icmp ping response",
864 "Limiting icmp tstamp response",
865 "Limiting closed port RST response",
866 "Limiting open port RST response"
870 * Return ok status if feature disabled or argument out of
874 if (icmplim
<= 0 || which
> BANDLIM_MAX
|| which
< 0)
876 dticks
= ticks
- lticks
[which
];
879 * reset stats when cumulative dt exceeds one second.
882 if ((unsigned int)dticks
> hz
) {
883 if (lpackets
[which
] > icmplim
&& icmplim_output
) {
884 kprintf("%s from %d to %d packets per second\n",
885 bandlimittype
[which
],
890 lticks
[which
] = ticks
;
898 if (++lpackets
[which
] > icmplim
) {