1 //==========================================================================
3 // src/sys/netinet/ip_icmp.c
5 //==========================================================================
6 //####BSDCOPYRIGHTBEGIN####
8 // -------------------------------------------
10 // Portions of this software may have been derived from OpenBSD,
11 // FreeBSD or other sources, and are covered by the appropriate
12 // copyright disclaimers included herein.
14 // Portions created by Red Hat are
15 // Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
17 // -------------------------------------------
19 //####BSDCOPYRIGHTEND####
20 //==========================================================================
23 * Copyright (c) 1982, 1986, 1988, 1993
24 * The Regents of the University of California. All rights reserved.
26 * Redistribution and use in source and binary forms, with or without
27 * modification, are permitted provided that the following conditions
29 * 1. Redistributions of source code must retain the above copyright
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32 * notice, this list of conditions and the following disclaimer in the
33 * documentation and/or other materials provided with the distribution.
34 * 3. All advertising materials mentioning features or use of this software
35 * must display the following acknowledgement:
36 * This product includes software developed by the University of
37 * California, Berkeley and its contributors.
38 * 4. Neither the name of the University nor the names of its contributors
39 * may be used to endorse or promote products derived from this software
40 * without specific prior written permission.
42 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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44 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
45 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
46 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
47 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
48 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
49 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
50 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
51 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
54 * @(#)ip_icmp.c 8.2 (Berkeley) 1/4/94
55 * $FreeBSD: src/sys/netinet/ip_icmp.c,v 1.39.2.9 2001/07/03 11:01:46 ume Exp $
58 #include <sys/param.h>
60 #include <sys/protosw.h>
61 #include <sys/socket.h>
62 #include <sys/sysctl.h>
65 #include <net/route.h>
68 #include <netinet/in.h>
69 #include <netinet/in_systm.h>
70 #include <netinet/in_var.h>
71 #include <netinet/ip.h>
72 #include <netinet/ip_icmp.h>
73 #include <netinet/ip_var.h>
74 #include <netinet/icmp_var.h>
77 #include <netinet6/ipsec.h>
78 #include <netkey/key.h>
82 * ICMP routines: error generation, receive packet processing, and
83 * routines to turnaround packets back to the originator, and
84 * host table maintenance routines.
87 struct icmpstat icmpstat;
88 SYSCTL_STRUCT(_net_inet_icmp, ICMPCTL_STATS, stats, CTLFLAG_RD,
89 &icmpstat, icmpstat, "");
91 static int icmpmaskrepl = 0;
92 SYSCTL_INT(_net_inet_icmp, ICMPCTL_MASKREPL, maskrepl, CTLFLAG_RW,
93 &icmpmaskrepl, 0, "");
95 static int drop_redirect = 0;
96 SYSCTL_INT(_net_inet_icmp, OID_AUTO, drop_redirect, CTLFLAG_RW,
97 &drop_redirect, 0, "");
99 static int log_redirect = 0;
100 SYSCTL_INT(_net_inet_icmp, OID_AUTO, log_redirect, CTLFLAG_RW,
101 &log_redirect, 0, "");
106 * ICMP error-response bandwidth limiting sysctl. If not enabled, sysctl
107 * variable content is -1 and read-only.
110 static int icmplim = 200;
111 SYSCTL_INT(_net_inet_icmp, ICMPCTL_ICMPLIM, icmplim, CTLFLAG_RW,
115 #ifdef CYGPKG_NET_FREEBSD_SYSCTL
116 static int icmplim = -1;
117 SYSCTL_INT(_net_inet_icmp, ICMPCTL_ICMPLIM, icmplim, CTLFLAG_RD,
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 __P((struct mbuf *));
135 static void icmp_send __P((struct mbuf *, struct mbuf *));
136 static int ip_next_mtu __P((int, int));
138 extern struct protosw inetsw[];
141 * Generate an error packet of type error
142 * in response to bad packet ip.
145 icmp_error(n, type, code, dest, destifp)
149 struct ifnet *destifp;
151 register struct ip *oip = mtod(n, struct ip *), *nip;
152 register unsigned oiplen = IP_VHL_HL(oip->ip_vhl) << 2;
153 register struct icmp *icp;
154 register struct mbuf *m;
159 printf("icmp_error(%p, %x, %d)\n", oip, type, code);
161 if (type != ICMP_REDIRECT)
162 icmpstat.icps_error++;
164 * Don't send error if not the first fragment of message.
165 * Don't error if the old packet protocol was ICMP
166 * error message, only known informational types.
168 if (oip->ip_off &~ (IP_MF|IP_DF))
170 if (oip->ip_p == IPPROTO_ICMP && type != ICMP_REDIRECT &&
171 n->m_len >= oiplen + ICMP_MINLEN &&
172 !ICMP_INFOTYPE(((struct icmp *)((caddr_t)oip + oiplen))->icmp_type)) {
173 icmpstat.icps_oldicmp++;
176 /* Don't send error in response to a multicast or broadcast packet */
177 if (n->m_flags & (M_BCAST|M_MCAST))
180 * First, formulate icmp message
182 m = m_gethdr(M_DONTWAIT, MT_HEADER);
185 icmplen = min(oiplen + 8, oip->ip_len);
186 if (icmplen < sizeof(struct ip)) {
187 printf("icmp_error: bad length\n");
191 m->m_len = icmplen + ICMP_MINLEN;
192 MH_ALIGN(m, m->m_len);
193 icp = mtod(m, struct icmp *);
194 if ((u_int)type > ICMP_MAXTYPE)
196 icmpstat.icps_outhist[type]++;
197 icp->icmp_type = type;
198 if (type == ICMP_REDIRECT)
199 icp->icmp_gwaddr.s_addr = dest;
203 * The following assignments assume an overlay with the
204 * zeroed icmp_void field.
206 if (type == ICMP_PARAMPROB) {
207 icp->icmp_pptr = code;
209 } else if (type == ICMP_UNREACH &&
210 code == ICMP_UNREACH_NEEDFRAG && destifp) {
211 icp->icmp_nextmtu = htons(destifp->if_mtu);
215 icp->icmp_code = code;
216 m_copydata(n, 0, icmplen, (caddr_t)&icp->icmp_ip);
220 * Convert fields to network representation.
226 * Now, copy old ip header (without options)
227 * in front of icmp message.
229 if (m->m_data - sizeof(struct ip) < m->m_pktdat)
231 m->m_data -= sizeof(struct ip);
232 m->m_len += sizeof(struct ip);
233 m->m_pkthdr.len = m->m_len;
234 m->m_pkthdr.rcvif = n->m_pkthdr.rcvif;
235 nip = mtod(m, struct ip *);
236 bcopy((caddr_t)oip, (caddr_t)nip, sizeof(struct ip));
237 nip->ip_len = m->m_len;
238 nip->ip_vhl = IP_VHL_BORING;
239 nip->ip_p = IPPROTO_ICMP;
247 static struct sockaddr_in icmpsrc = { sizeof (struct sockaddr_in), AF_INET };
248 static struct sockaddr_in icmpdst = { sizeof (struct sockaddr_in), AF_INET };
249 static struct sockaddr_in icmpgw = { sizeof (struct sockaddr_in), AF_INET };
252 * Process a received ICMP message.
256 register struct mbuf *m;
260 register struct icmp *icp;
261 register struct ip *ip = mtod(m, struct ip *);
262 int icmplen = ip->ip_len;
264 struct in_ifaddr *ia;
265 void (*ctlfunc) __P((int, struct sockaddr *, void *));
269 * Locate icmp structure in mbuf, and check
270 * that not corrupted and of at least minimum length.
274 char buf[4 * sizeof "123"];
275 strcpy(buf, inet_ntoa(ip->ip_src));
276 printf("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 defined(NFAITH) && 0 < NFAITH
301 if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_type == IFT_FAITH) {
303 * Deliver very specific ICMP type only.
305 switch (icp->icmp_type) {
317 printf("icmp_input, type %d code %d\n", icp->icmp_type,
322 * Message type specific processing.
324 if (icp->icmp_type > ICMP_MAXTYPE)
326 icmpstat.icps_inhist[icp->icmp_type]++;
327 code = icp->icmp_code;
328 switch (icp->icmp_type) {
332 case ICMP_UNREACH_NET:
333 case ICMP_UNREACH_HOST:
334 case ICMP_UNREACH_SRCFAIL:
335 case ICMP_UNREACH_NET_UNKNOWN:
336 case ICMP_UNREACH_HOST_UNKNOWN:
337 case ICMP_UNREACH_ISOLATED:
338 case ICMP_UNREACH_TOSNET:
339 case ICMP_UNREACH_TOSHOST:
340 case ICMP_UNREACH_HOST_PRECEDENCE:
341 case ICMP_UNREACH_PRECEDENCE_CUTOFF:
342 code = PRC_UNREACH_NET;
345 case ICMP_UNREACH_NEEDFRAG:
350 * RFC 1122, Sections 3.2.2.1 and 4.2.3.9.
351 * Treat subcodes 2,3 as immediate RST
353 case ICMP_UNREACH_PROTOCOL:
354 case ICMP_UNREACH_PORT:
355 code = PRC_UNREACH_PORT;
358 case ICMP_UNREACH_NET_PROHIB:
359 case ICMP_UNREACH_HOST_PROHIB:
360 case ICMP_UNREACH_FILTER_PROHIB:
361 code = PRC_UNREACH_ADMIN_PROHIB;
372 code += PRC_TIMXCEED_INTRANS;
378 code = PRC_PARAMPROB;
381 case ICMP_SOURCEQUENCH:
387 * Problem with datagram; advise higher level routines.
389 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) ||
390 IP_VHL_HL(icp->icmp_ip.ip_vhl) < (sizeof(struct ip) >> 2)) {
391 icmpstat.icps_badlen++;
394 NTOHS(icp->icmp_ip.ip_len);
395 /* Discard ICMP's in response to multicast packets */
396 if (IN_MULTICAST(ntohl(icp->icmp_ip.ip_dst.s_addr)))
400 printf("deliver to protocol %d\n", icp->icmp_ip.ip_p);
402 icmpsrc.sin_addr = icp->icmp_ip.ip_dst;
406 * If we got a needfrag and there is a host route to the
407 * original destination, and the MTU is not locked, then
408 * set the MTU in the route to the suggested new value
409 * (if given) and then notify as usual. The ULPs will
410 * notice that the MTU has changed and adapt accordingly.
411 * If no new MTU was suggested, then we guess a new one
412 * less than the current value. If the new MTU is
413 * unreasonably small (arbitrarily set at 296), then
414 * we reset the MTU to the interface value and enable the
415 * lock bit, indicating that we are no longer doing MTU
418 if (code == PRC_MSGSIZE) {
422 rt = rtalloc1((struct sockaddr *)&icmpsrc, 0,
423 RTF_CLONING | RTF_PRCLONING);
424 if (rt && (rt->rt_flags & RTF_HOST)
425 && !(rt->rt_rmx.rmx_locks & RTV_MTU)) {
426 mtu = ntohs(icp->icmp_nextmtu);
428 mtu = ip_next_mtu(rt->rt_rmx.rmx_mtu,
431 printf("MTU for %s reduced to %d\n",
432 inet_ntoa(icmpsrc.sin_addr), mtu);
435 /* rt->rt_rmx.rmx_mtu =
436 rt->rt_ifp->if_mtu; */
437 rt->rt_rmx.rmx_locks |= RTV_MTU;
438 } else if (rt->rt_rmx.rmx_mtu > mtu) {
439 rt->rt_rmx.rmx_mtu = mtu;
448 * XXX if the packet contains [IPv4 AH TCP], we can't make a
449 * notification to TCP layer.
451 ctlfunc = inetsw[ip_protox[icp->icmp_ip.ip_p]].pr_ctlinput;
453 (*ctlfunc)(code, (struct sockaddr *)&icmpsrc,
454 (void *)&icp->icmp_ip);
458 icmpstat.icps_badcode++;
463 && (m->m_flags & (M_MCAST | M_BCAST)) != 0) {
464 icmpstat.icps_bmcastecho++;
467 icp->icmp_type = ICMP_ECHOREPLY;
469 if (badport_bandlim(BANDLIM_ICMP_ECHO) < 0)
477 && (m->m_flags & (M_MCAST | M_BCAST)) != 0) {
478 icmpstat.icps_bmcasttstamp++;
481 if (icmplen < ICMP_TSLEN) {
482 icmpstat.icps_badlen++;
485 icp->icmp_type = ICMP_TSTAMPREPLY;
486 icp->icmp_rtime = iptime();
487 icp->icmp_ttime = icp->icmp_rtime; /* bogus, do later! */
489 if (badport_bandlim(BANDLIM_ICMP_TSTAMP) < 0)
496 #define satosin(sa) ((struct sockaddr_in *)(sa))
497 if (icmpmaskrepl == 0)
500 * We are not able to respond with all ones broadcast
501 * unless we receive it over a point-to-point interface.
503 if (icmplen < ICMP_MASKLEN)
505 switch (ip->ip_dst.s_addr) {
507 case INADDR_BROADCAST:
509 icmpdst.sin_addr = ip->ip_src;
513 icmpdst.sin_addr = ip->ip_dst;
515 ia = (struct in_ifaddr *)ifaof_ifpforaddr(
516 (struct sockaddr *)&icmpdst, m->m_pkthdr.rcvif);
521 icp->icmp_type = ICMP_MASKREPLY;
522 icp->icmp_mask = ia->ia_sockmask.sin_addr.s_addr;
523 if (ip->ip_src.s_addr == 0) {
524 if (ia->ia_ifp->if_flags & IFF_BROADCAST)
525 ip->ip_src = satosin(&ia->ia_broadaddr)->sin_addr;
526 else if (ia->ia_ifp->if_flags & IFF_POINTOPOINT)
527 ip->ip_src = satosin(&ia->ia_dstaddr)->sin_addr;
530 ip->ip_len += hlen; /* since ip_input deducts this */
531 icmpstat.icps_reflect++;
532 icmpstat.icps_outhist[icp->icmp_type]++;
540 src = ntohl(ip->ip_src.s_addr);
541 dst = ntohl(icp->icmp_ip.ip_dst.s_addr);
542 gw = ntohl(icp->icmp_gwaddr.s_addr);
543 printf("icmp redirect from %d.%d.%d.%d: "
544 "%d.%d.%d.%d => %d.%d.%d.%d\n",
545 (int)(src >> 24), (int)((src >> 16) & 0xff),
546 (int)((src >> 8) & 0xff), (int)(src & 0xff),
547 (int)(dst >> 24), (int)((dst >> 16) & 0xff),
548 (int)((dst >> 8) & 0xff), (int)(dst & 0xff),
549 (int)(gw >> 24), (int)((gw >> 16) & 0xff),
550 (int)((gw >> 8) & 0xff), (int)(gw & 0xff));
556 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) ||
557 IP_VHL_HL(icp->icmp_ip.ip_vhl) < (sizeof(struct ip) >> 2)) {
558 icmpstat.icps_badlen++;
562 * Short circuit routing redirects to force
563 * immediate change in the kernel's routing
564 * tables. The message is also handed to anyone
565 * listening on a raw socket (e.g. the routing
566 * daemon for use in updating its tables).
568 icmpgw.sin_addr = ip->ip_src;
569 icmpdst.sin_addr = icp->icmp_gwaddr;
572 char buf[4 * sizeof "123"];
573 strcpy(buf, inet_ntoa(icp->icmp_ip.ip_dst));
575 printf("redirect dst %s to %s\n",
576 buf, inet_ntoa(icp->icmp_gwaddr));
579 icmpsrc.sin_addr = icp->icmp_ip.ip_dst;
580 rtredirect((struct sockaddr *)&icmpsrc,
581 (struct sockaddr *)&icmpdst,
582 (struct sockaddr *)0, RTF_GATEWAY | RTF_HOST,
583 (struct sockaddr *)&icmpgw, (struct rtentry **)0);
584 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&icmpsrc);
586 key_sa_routechange((struct sockaddr *)&icmpsrc);
591 * No kernel processing for the following;
592 * just fall through to send to raw listener.
595 case ICMP_ROUTERADVERT:
596 case ICMP_ROUTERSOLICIT:
597 case ICMP_TSTAMPREPLY:
613 * Reflect the ip packet back to the source
619 register struct ip *ip = mtod(m, struct ip *);
620 register struct in_ifaddr *ia;
622 struct mbuf *opts = 0;
623 int optlen = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip);
625 if (!in_canforward(ip->ip_src) &&
626 ((ntohl(ip->ip_src.s_addr) & IN_CLASSA_NET) !=
627 (IN_LOOPBACKNET << IN_CLASSA_NSHIFT))) {
628 m_freem(m); /* Bad return address */
629 goto done; /* Ip_output() will check for broadcast */
632 ip->ip_dst = ip->ip_src;
634 * If the incoming packet was addressed directly to us,
635 * use dst as the src for the reply. Otherwise (broadcast
636 * or anonymous), use the address which corresponds
637 * to the incoming interface.
639 for (ia = in_ifaddrhead.tqh_first; ia; ia = ia->ia_link.tqe_next) {
640 if (t.s_addr == IA_SIN(ia)->sin_addr.s_addr)
642 if (ia->ia_ifp && (ia->ia_ifp->if_flags & IFF_BROADCAST) &&
643 t.s_addr == satosin(&ia->ia_broadaddr)->sin_addr.s_addr)
646 icmpdst.sin_addr = t;
647 if ((ia == (struct in_ifaddr *)0) && m->m_pkthdr.rcvif)
648 ia = (struct in_ifaddr *)ifaof_ifpforaddr(
649 (struct sockaddr *)&icmpdst, m->m_pkthdr.rcvif);
651 * The following happens if the packet was not addressed to us,
652 * and was received on an interface with no IP address.
654 if (ia == (struct in_ifaddr *)0)
655 ia = in_ifaddrhead.tqh_first;
656 t = IA_SIN(ia)->sin_addr;
658 ip->ip_ttl = ip_defttl;
666 * Retrieve any source routing from the incoming packet;
667 * add on any record-route or timestamp options.
669 cp = (u_char *) (ip + 1);
670 if ((opts = ip_srcroute()) == 0 &&
671 (opts = m_gethdr(M_DONTWAIT, MT_HEADER))) {
672 opts->m_len = sizeof(struct in_addr);
673 mtod(opts, struct in_addr *)->s_addr = 0;
678 printf("icmp_reflect optlen %d rt %d => ",
679 optlen, opts->m_len);
681 for (cnt = optlen; cnt > 0; cnt -= len, cp += len) {
682 opt = cp[IPOPT_OPTVAL];
683 if (opt == IPOPT_EOL)
685 if (opt == IPOPT_NOP)
688 if (cnt < IPOPT_OLEN + sizeof(*cp))
690 len = cp[IPOPT_OLEN];
691 if (len < IPOPT_OLEN + sizeof(*cp) ||
696 * Should check for overflow, but it "can't happen"
698 if (opt == IPOPT_RR || opt == IPOPT_TS ||
699 opt == IPOPT_SECURITY) {
701 mtod(opts, caddr_t) + opts->m_len, len);
705 /* Terminate & pad, if necessary */
706 cnt = opts->m_len % 4;
708 for (; cnt < 4; cnt++) {
709 *(mtod(opts, caddr_t) + opts->m_len) =
716 printf("%d\n", opts->m_len);
720 * Now strip out original options by copying rest of first
721 * mbuf's data back, and adjust the IP length.
723 ip->ip_len -= optlen;
724 ip->ip_vhl = IP_VHL_BORING;
726 if (m->m_flags & M_PKTHDR)
727 m->m_pkthdr.len -= optlen;
728 optlen += sizeof(struct ip);
729 bcopy((caddr_t)ip + optlen, (caddr_t)(ip + 1),
730 (unsigned)(m->m_len - sizeof(struct ip)));
732 m->m_flags &= ~(M_BCAST|M_MCAST);
740 * Send an icmp packet back to the ip level,
741 * after supplying a checksum.
745 register struct mbuf *m;
748 register struct ip *ip = mtod(m, struct ip *);
750 register struct icmp *icp;
753 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
756 icp = mtod(m, struct icmp *);
758 icp->icmp_cksum = in_cksum(m, ip->ip_len - hlen);
761 m->m_pkthdr.rcvif = (struct ifnet *)0;
764 char buf[4 * sizeof "123"];
765 strcpy(buf, inet_ntoa(ip->ip_dst));
766 printf("icmp_send dst %s src %s\n",
767 buf, inet_ntoa(ip->ip_src));
770 bzero(&ro, sizeof ro);
771 (void) ip_output(m, opts, &ro, 0, NULL);
783 t = (atv.tv_sec % (24*60*60)) * 1000 + atv.tv_usec / 1000;
789 * Return the next larger or smaller MTU plateau (table from RFC 1191)
790 * given current value MTU. If DIR is less than zero, a larger plateau
791 * is returned; otherwise, a smaller value is returned.
794 ip_next_mtu(mtu, dir)
798 static int mtutab[] = {
799 65535, 32000, 17914, 8166, 4352, 2002, 1492, 1006, 508, 296,
804 for (i = 0; i < (sizeof mtutab) / (sizeof mtutab[0]); i++) {
805 if (mtu >= mtutab[i])
813 return mtutab[i - 1];
816 if (mtutab[i] == 0) {
818 } else if(mtu > mtutab[i]) {
821 return mtutab[i + 1];
830 * badport_bandlim() - check for ICMP bandwidth limit
832 * Return 0 if it is ok to send an ICMP error response, -1 if we have
833 * hit our bandwidth limit and it is not ok.
835 * If icmplim is <= 0, the feature is disabled and 0 is returned.
837 * For now we separate the TCP and UDP subsystems w/ different 'which'
838 * values. We may eventually remove this separation (and simplify the
841 * Note that the printing of the error message is delayed so we can
842 * properly print the icmp error rate that the system was trying to do
843 * (i.e. 22000/100 pps, etc...). This can cause long delays in printing
844 * the 'final' error, but it doesn't make sense to solve the printing
845 * delay with more complex code.
849 badport_bandlim(int which)
851 static int lticks[BANDLIM_MAX + 1];
852 static int lpackets[BANDLIM_MAX + 1];
854 const char *bandlimittype[] = {
855 "Limiting icmp unreach response",
856 "Limiting icmp ping response",
857 "Limiting icmp tstamp response",
858 "Limiting closed port RST response",
859 "Limiting open port RST response"
863 * Return ok status if feature disabled or argument out of
867 if (icmplim <= 0 || which > BANDLIM_MAX || which < 0)
869 dticks = ticks - lticks[which];
872 * reset stats when cumulative dt exceeds one second.
875 if ((unsigned int)dticks > hz) {
876 if (lpackets[which] > icmplim) {
877 printf("%s from %d to %d packets per second\n",
878 bandlimittype[which],
883 lticks[which] = ticks;
891 if (++lpackets[which] > icmplim) {