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. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * @(#)ip_icmp.c 8.2 (Berkeley) 1/4/94
30 * $FreeBSD: src/sys/netinet/ip_icmp.c,v 1.39.2.19 2003/01/24 05:11:34 sam Exp $
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/malloc.h> /* for M_NOWAIT */
37 #include <sys/protosw.h>
38 #include <sys/socket.h>
39 #include <sys/socketops.h>
41 #include <sys/kernel.h>
42 #include <sys/sysctl.h>
43 #include <sys/in_cksum.h>
45 #include <machine/stdarg.h>
48 #include <net/if_types.h>
49 #include <net/netisr2.h>
50 #include <net/netmsg2.h>
51 #include <net/route.h>
54 #include <netinet/in.h>
55 #include <netinet/in_systm.h>
56 #include <netinet/in_var.h>
57 #include <netinet/ip.h>
58 #include <netinet/ip_icmp.h>
59 #include <netinet/ip_var.h>
60 #include <netinet/icmp_var.h>
63 * ICMP routines: error generation, receive packet processing, and
64 * routines to turnaround packets back to the originator, and
65 * host table maintenance routines.
68 struct icmpstat icmpstat;
69 SYSCTL_STRUCT(_net_inet_icmp, ICMPCTL_STATS, stats, CTLFLAG_RW,
70 &icmpstat, icmpstat, "ICMP statistics");
72 static int icmpmaskrepl = 0;
73 SYSCTL_INT(_net_inet_icmp, ICMPCTL_MASKREPL, maskrepl, CTLFLAG_RW,
74 &icmpmaskrepl, 0, "Allow replies to netmask requests");
76 static int drop_redirect = 0;
77 SYSCTL_INT(_net_inet_icmp, OID_AUTO, drop_redirect, CTLFLAG_RW,
78 &drop_redirect, 0, "Ignore ICMP redirects");
80 static int log_redirect = 0;
81 SYSCTL_INT(_net_inet_icmp, OID_AUTO, log_redirect, CTLFLAG_RW,
82 &log_redirect, 0, "Enable output about ICMP redirects");
84 static int discard_sourcequench = 1;
85 SYSCTL_INT(_net_inet_icmp, OID_AUTO, discard_sourcequench, CTLFLAG_RW,
86 &discard_sourcequench, 0, "Discard ICMP Source Quench");
91 * ICMP error-response bandwidth limiting sysctl. If not enabled, sysctl
92 * variable content is -1 and read-only.
95 static int icmplim = 200;
96 SYSCTL_INT(_net_inet_icmp, ICMPCTL_ICMPLIM, icmplim, CTLFLAG_RW,
97 &icmplim, 0, "ICMP bandwidth limit");
100 static int icmplim = -1;
101 SYSCTL_INT(_net_inet_icmp, ICMPCTL_ICMPLIM, icmplim, CTLFLAG_RD,
102 &icmplim, 0, "ICMP bandwidth limit");
106 static int icmplim_output = 0;
107 SYSCTL_INT(_net_inet_icmp, OID_AUTO, icmplim_output, CTLFLAG_RW,
108 &icmplim_output, 0, "Enable output about ICMP bandwidth limits");
111 * ICMP broadcast echo sysctl
114 static int icmpbmcastecho = 0;
115 SYSCTL_INT(_net_inet_icmp, OID_AUTO, bmcastecho, CTLFLAG_RW,
116 &icmpbmcastecho, 0, "");
118 static char icmp_reply_src[IFNAMSIZ];
119 SYSCTL_STRING(_net_inet_icmp, OID_AUTO, reply_src, CTLFLAG_RW,
120 icmp_reply_src, IFNAMSIZ, "icmp reply source for non-local packets.");
123 SYSCTL_INT(_net_inet_icmp, OID_AUTO, reply_from_interface, CTLFLAG_RW,
124 &icmp_rfi, 0, "ICMP reply from incoming interface for "
125 "non-local packets");
128 static int icmpprintfs = 0;
129 SYSCTL_INT(_net_inet_icmp, OID_AUTO, debug_prints, CTLFLAG_RW,
130 &icmpprintfs, 0, "extra ICMP debug prints");
133 static void icmp_reflect (struct mbuf *);
134 static void icmp_send (struct mbuf *, struct mbuf *, struct route *);
136 extern struct protosw inetsw[];
139 * Generate an error packet of type error
140 * in response to bad packet ip.
143 icmp_error(struct mbuf *n, int type, int code, n_long dest, int destmtu)
145 struct ip *oip = mtod(n, struct ip *), *nip;
146 unsigned oiplen = IP_VHL_HL(oip->ip_vhl) << 2;
153 kprintf("icmp_error(%p, %d, %d)\n", oip, type, code);
155 if (type != ICMP_REDIRECT)
156 icmpstat.icps_error++;
158 * Don't send error if the original packet was encrypted.
159 * Don't send error if not the first fragment of message.
160 * Don't error if the old packet protocol was ICMP
161 * error message, only known informational types.
163 if (n->m_flags & M_DECRYPTED)
165 if (oip->ip_off &~ (IP_MF|IP_DF))
167 if (oip->ip_p == IPPROTO_ICMP && type != ICMP_REDIRECT &&
168 n->m_len >= oiplen + ICMP_MINLEN &&
169 !ICMP_INFOTYPE(((struct icmp *)((caddr_t)oip + oiplen))->icmp_type)) {
170 icmpstat.icps_oldicmp++;
173 /* Don't send error in response to a multicast or broadcast packet */
174 if (n->m_flags & (M_BCAST|M_MCAST))
177 * First, formulate icmp message
179 m = m_gethdr(M_NOWAIT, MT_HEADER);
182 icmplen = min(oiplen + 8, oip->ip_len);
183 if (icmplen < sizeof(struct ip))
184 panic("icmp_error: bad length");
185 m->m_len = icmplen + ICMP_MINLEN;
186 MH_ALIGN(m, m->m_len);
187 icp = mtod(m, struct icmp *);
188 if ((u_int)type > ICMP_MAXTYPE)
190 icmpstat.icps_outhist[type]++;
191 icp->icmp_type = type;
192 if (type == ICMP_REDIRECT)
193 icp->icmp_gwaddr.s_addr = dest;
197 * The following assignments assume an overlay with the
198 * zeroed icmp_void field.
200 if (type == ICMP_PARAMPROB) {
201 icp->icmp_pptr = code;
203 } else if (type == ICMP_UNREACH &&
204 code == ICMP_UNREACH_NEEDFRAG && destmtu) {
205 icp->icmp_nextmtu = htons(destmtu);
209 icp->icmp_code = code;
210 m_copydata(n, 0, icmplen, (caddr_t)&icp->icmp_ip);
214 * Convert fields to network representation.
216 nip->ip_len = htons(nip->ip_len);
217 nip->ip_off = htons(nip->ip_off);
220 * Now, copy old ip header (without options)
221 * in front of icmp message.
223 if (m->m_data - sizeof(struct ip) < m->m_pktdat)
225 m->m_data -= sizeof(struct ip);
226 m->m_len += sizeof(struct ip);
227 m->m_pkthdr.len = m->m_len;
228 m->m_pkthdr.rcvif = n->m_pkthdr.rcvif;
229 nip = mtod(m, struct ip *);
230 bcopy(oip, nip, sizeof(struct ip));
231 nip->ip_len = m->m_len;
232 nip->ip_vhl = IP_VHL_BORING;
233 nip->ip_p = IPPROTO_ICMP;
235 m->m_pkthdr.fw_flags |= n->m_pkthdr.fw_flags & FW_MBUF_GENERATED;
243 icmp_ctlinput_done_handler(netmsg_t nmsg)
245 struct netmsg_ctlinput *msg = (struct netmsg_ctlinput *)nmsg;
246 struct mbuf *m = msg->m;
247 int hlen = msg->hlen;
249 rip_input(&m, &hlen, msg->proto);
253 icmp_ctlinput_done(struct mbuf *m)
255 struct netmsg_ctlinput *msg = &m->m_hdr.mh_ctlmsg;
257 netmsg_init(&msg->base, NULL, &netisr_apanic_rport, 0,
258 icmp_ctlinput_done_handler);
259 lwkt_sendmsg(netisr_cpuport(0), &msg->base.lmsg);
263 icmp_mtudisc(struct mbuf *m, int hlen)
265 struct sockaddr_in icmpsrc = { sizeof(struct sockaddr_in), AF_INET };
269 KASSERT(curthread->td_type == TD_TYPE_NETISR, ("not in netisr"));
271 icp = mtodoff(m, struct icmp *, hlen);
272 icmpsrc.sin_addr = icp->icmp_ip.ip_dst;
276 * If we got a needfrag and there is a host route to the original
277 * destination, and the MTU is not locked, then set the MTU in the
278 * route to the suggested new value (if given) and then notify as
279 * usual. The ULPs will notice that the MTU has changed and adapt
280 * accordingly. If no new MTU was suggested, then we guess a new
281 * one less than the current value. If the new MTU is unreasonably
282 * small (arbitrarily set at 296), then we reset the MTU to the
283 * interface value and enable the lock bit, indicating that we are
284 * no longer doing MTU discovery.
286 rt = rtpurelookup((struct sockaddr *)&icmpsrc);
287 if (rt != NULL && (rt->rt_flags & RTF_HOST) &&
288 !(rt->rt_rmx.rmx_locks & RTV_MTU)) {
290 char src_buf[INET_ADDRSTRLEN];
294 mtu = ntohs(icp->icmp_nextmtu);
296 mtu = ip_next_mtu(rt->rt_rmx.rmx_mtu, 1);
298 kprintf("MTU for %s reduced to %d\n",
299 inet_ntop(AF_INET, &icmpsrc.sin_addr,
300 src_buf, INET_ADDRSTRLEN), mtu);
303 /* rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; */
304 rt->rt_rmx.rmx_locks |= RTV_MTU;
305 } else if (rt->rt_rmx.rmx_mtu > mtu) {
306 rt->rt_rmx.rmx_mtu = mtu;
313 * XXX if the packet contains [IPv4 AH TCP], we can't make a
314 * notification to TCP layer.
316 so_pr_ctlinput_direct(&inetsw[ip_protox[icp->icmp_ip.ip_p]],
317 PRC_MSGSIZE, (struct sockaddr *)&icmpsrc, &icp->icmp_ip);
321 icmp_mtudisc_handler(netmsg_t nmsg)
323 struct netmsg_ctlinput *msg = (struct netmsg_ctlinput *)nmsg;
326 ASSERT_NETISR_NCPUS(mycpuid);
328 icmp_mtudisc(msg->m, msg->hlen);
330 nextcpu = mycpuid + 1;
331 if (nextcpu < netisr_ncpus)
332 lwkt_forwardmsg(netisr_cpuport(nextcpu), &msg->base.lmsg);
334 icmp_ctlinput_done(msg->m);
338 icmp_mtudisc_start(struct mbuf *m, int hlen, int proto)
340 struct netmsg_ctlinput *msg;
344 icmp_mtudisc(m, hlen);
346 if (netisr_ncpus == 1) {
347 /* There is only one netisr; done */
351 msg = &m->m_hdr.mh_ctlmsg;
352 netmsg_init(&msg->base, NULL, &netisr_apanic_rport, 0,
353 icmp_mtudisc_handler);
355 msg->cmd = PRC_MSGSIZE;
359 lwkt_sendmsg(netisr_cpuport(1), &msg->base.lmsg);
364 icmp_ctlinput(struct mbuf *m, int cmd, int hlen)
366 struct sockaddr_in icmpsrc = { sizeof(struct sockaddr_in), AF_INET };
369 KASSERT(curthread->td_type == TD_TYPE_NETISR, ("not in netisr"));
371 icp = mtodoff(m, struct icmp *, hlen);
372 icmpsrc.sin_addr = icp->icmp_ip.ip_dst;
375 * XXX if the packet contains [IPv4 AH TCP], we can't make a
376 * notification to TCP layer.
378 so_pr_ctlinput_direct(&inetsw[ip_protox[icp->icmp_ip.ip_p]],
379 cmd, (struct sockaddr *)&icmpsrc, &icp->icmp_ip);
383 icmp_ctlinput_handler(netmsg_t nmsg)
385 struct netmsg_ctlinput *msg = (struct netmsg_ctlinput *)nmsg;
387 ASSERT_NETISR_NCPUS(mycpuid);
389 icmp_ctlinput(msg->m, msg->cmd, msg->hlen);
390 icmp_ctlinput_done(msg->m);
394 icmp_ctlinput_start(struct mbuf *m, struct lwkt_port *port,
395 int cmd, int hlen, int proto)
397 struct netmsg_ctlinput *msg;
399 KASSERT(&curthread->td_msgport != port,
400 ("send icmp ctlinput to the current netisr"));
402 msg = &m->m_hdr.mh_ctlmsg;
403 netmsg_init(&msg->base, NULL, &netisr_apanic_rport, 0,
404 icmp_ctlinput_handler);
410 lwkt_sendmsg(port, &msg->base.lmsg);
414 icmp_ctlinput_global_handler(netmsg_t nmsg)
416 struct netmsg_ctlinput *msg = (struct netmsg_ctlinput *)nmsg;
419 ASSERT_NETISR_NCPUS(mycpuid);
421 icmp_ctlinput(msg->m, msg->cmd, msg->hlen);
423 nextcpu = mycpuid + 1;
424 if (nextcpu < netisr_ncpus)
425 lwkt_forwardmsg(netisr_cpuport(nextcpu), &msg->base.lmsg);
427 icmp_ctlinput_done(msg->m);
431 icmp_ctlinput_global_start(struct mbuf *m, int cmd, int hlen, int proto)
433 struct netmsg_ctlinput *msg;
436 KASSERT(netisr_ncpus > 1, ("there is only 1 netisr cpu"));
438 icmp_ctlinput(m, cmd, hlen);
440 msg = &m->m_hdr.mh_ctlmsg;
441 netmsg_init(&msg->base, NULL, &netisr_apanic_rport, 0,
442 icmp_ctlinput_global_handler);
448 lwkt_sendmsg(netisr_cpuport(1), &msg->base.lmsg);
451 #define ICMP_RTREDIRECT_FLAGS (RTF_GATEWAY | RTF_HOST)
454 icmp_redirect(struct mbuf *m, int hlen, boolean_t prt)
456 struct sockaddr_in icmpsrc = { sizeof(struct sockaddr_in), AF_INET };
457 struct sockaddr_in icmpdst = { sizeof(struct sockaddr_in), AF_INET };
458 struct sockaddr_in icmpgw = { sizeof(struct sockaddr_in), AF_INET };
462 KASSERT(curthread->td_type == TD_TYPE_NETISR, ("not in netisr"));
464 ip = mtod(m, struct ip *);
465 icp = mtodoff(m, struct icmp *, hlen);
468 * Short circuit routing redirects to force immediate change
469 * in the kernel's routing tables. The message is also handed
470 * to anyone listening on a raw socket (e.g. the routing daemon
471 * for use in updating its tables).
474 if (icmpprintfs && prt) {
475 char dst_buf[INET_ADDRSTRLEN], gw_buf[INET_ADDRSTRLEN];
477 kprintf("redirect dst %s to %s\n",
478 inet_ntop(AF_INET, &icp->icmp_ip.ip_dst,
479 dst_buf, INET_ADDRSTRLEN),
480 inet_ntop(AF_INET, &icp->icmp_gwaddr,
481 gw_buf, INET_ADDRSTRLEN));
484 icmpgw.sin_addr = ip->ip_src;
485 icmpdst.sin_addr = icp->icmp_gwaddr;
486 icmpsrc.sin_addr = icp->icmp_ip.ip_dst;
487 rtredirect_oncpu((struct sockaddr *)&icmpsrc,
488 (struct sockaddr *)&icmpdst, NULL, ICMP_RTREDIRECT_FLAGS,
489 (struct sockaddr *)&icmpgw);
490 kpfctlinput_direct(PRC_REDIRECT_HOST, (struct sockaddr *)&icmpsrc);
494 icmp_redirect_done_handler(netmsg_t nmsg)
496 struct netmsg_ctlinput *msg = (struct netmsg_ctlinput *)nmsg;
497 struct mbuf *m = msg->m;
498 int hlen = msg->hlen;
500 rip_input(&m, &hlen, msg->proto);
504 icmp_redirect_done(struct mbuf *m, int hlen, boolean_t dispatch_rip)
506 struct rt_addrinfo rtinfo;
507 struct sockaddr_in icmpsrc = { sizeof(struct sockaddr_in), AF_INET };
508 struct sockaddr_in icmpdst = { sizeof(struct sockaddr_in), AF_INET };
509 struct sockaddr_in icmpgw = { sizeof(struct sockaddr_in), AF_INET };
513 ip = mtod(m, struct ip *);
514 icp = mtodoff(m, struct icmp *, hlen);
516 icmpgw.sin_addr = ip->ip_src;
517 icmpdst.sin_addr = icp->icmp_gwaddr;
518 icmpsrc.sin_addr = icp->icmp_ip.ip_dst;
520 bzero(&rtinfo, sizeof(struct rt_addrinfo));
521 rtinfo.rti_info[RTAX_DST] = (struct sockaddr *)&icmpsrc;
522 rtinfo.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&icmpdst;
523 rtinfo.rti_info[RTAX_NETMASK] = NULL;
524 rtinfo.rti_info[RTAX_AUTHOR] = (struct sockaddr *)&icmpgw;
525 rt_missmsg(RTM_REDIRECT, &rtinfo, ICMP_RTREDIRECT_FLAGS, 0);
528 struct netmsg_ctlinput *msg = &m->m_hdr.mh_ctlmsg;
530 netmsg_init(&msg->base, NULL, &netisr_apanic_rport, 0,
531 icmp_redirect_done_handler);
532 lwkt_sendmsg(netisr_cpuport(0), &msg->base.lmsg);
537 icmp_redirect_handler(netmsg_t nmsg)
539 struct netmsg_ctlinput *msg = (struct netmsg_ctlinput *)nmsg;
542 ASSERT_NETISR_NCPUS(mycpuid);
544 icmp_redirect(msg->m, msg->hlen, FALSE);
546 nextcpu = mycpuid + 1;
547 if (nextcpu < netisr_ncpus)
548 lwkt_forwardmsg(netisr_cpuport(nextcpu), &msg->base.lmsg);
550 icmp_redirect_done(msg->m, msg->hlen, TRUE);
554 icmp_redirect_start(struct mbuf *m, int hlen, int proto)
556 struct netmsg_ctlinput *msg;
560 icmp_redirect(m, hlen, TRUE);
562 if (netisr_ncpus == 1) {
563 /* There is only one netisr; done */
564 icmp_redirect_done(m, hlen, FALSE);
568 msg = &m->m_hdr.mh_ctlmsg;
569 netmsg_init(&msg->base, NULL, &netisr_apanic_rport, 0,
570 icmp_redirect_handler);
572 msg->cmd = PRC_REDIRECT_HOST;
576 lwkt_sendmsg(netisr_cpuport(1), &msg->base.lmsg);
581 * Process a received ICMP message.
584 icmp_input(struct mbuf **mp, int *offp, int proto)
586 struct sockaddr_in icmpsrc = { sizeof(struct sockaddr_in), AF_INET };
587 struct sockaddr_in icmpdst = { sizeof(struct sockaddr_in), AF_INET };
589 struct in_ifaddr *ia;
590 struct mbuf *m = *mp;
591 struct ip *ip = mtod(m, struct ip *);
592 int icmplen = ip->ip_len;
602 * Locate icmp structure in mbuf, and check
603 * that not corrupted and of at least minimum length.
607 char src_buf[INET_ADDRSTRLEN], dst_buf[INET_ADDRSTRLEN];
609 kprintf("icmp_input from %s to %s, len %d\n",
610 inet_ntop(AF_INET, &ip->ip_src, src_buf, INET_ADDRSTRLEN),
611 inet_ntop(AF_INET, &ip->ip_dst, dst_buf, INET_ADDRSTRLEN),
615 if (icmplen < ICMP_MINLEN) {
616 icmpstat.icps_tooshort++;
619 i = hlen + min(icmplen, ICMP_ADVLENMIN);
620 if (m->m_len < i && (m = m_pullup(m, i)) == NULL) {
621 icmpstat.icps_tooshort++;
622 return(IPPROTO_DONE);
624 ip = mtod(m, struct ip *);
626 if (in_cksum_skip(m, hlen + icmplen, hlen)) {
627 icmpstat.icps_checksum++;
630 icp = (struct icmp *)((caddr_t)ip + hlen);
634 kprintf("icmp_input, type %d code %d\n", icp->icmp_type,
639 * Message type specific processing.
641 if (icp->icmp_type > ICMP_MAXTYPE)
643 icmpstat.icps_inhist[icp->icmp_type]++;
644 code = icp->icmp_code;
645 switch (icp->icmp_type) {
649 case ICMP_UNREACH_NET:
650 case ICMP_UNREACH_HOST:
651 case ICMP_UNREACH_SRCFAIL:
652 case ICMP_UNREACH_NET_UNKNOWN:
653 case ICMP_UNREACH_HOST_UNKNOWN:
654 case ICMP_UNREACH_ISOLATED:
655 case ICMP_UNREACH_TOSNET:
656 case ICMP_UNREACH_TOSHOST:
657 case ICMP_UNREACH_HOST_PRECEDENCE:
658 case ICMP_UNREACH_PRECEDENCE_CUTOFF:
659 code = PRC_UNREACH_NET;
662 case ICMP_UNREACH_NEEDFRAG:
667 * RFC 1122, Sections 3.2.2.1 and 4.2.3.9.
668 * Treat subcodes 2,3 as immediate RST
670 case ICMP_UNREACH_PROTOCOL:
671 case ICMP_UNREACH_PORT:
672 code = PRC_UNREACH_PORT;
675 case ICMP_UNREACH_NET_PROHIB:
676 case ICMP_UNREACH_HOST_PROHIB:
677 case ICMP_UNREACH_FILTER_PROHIB:
678 code = PRC_UNREACH_ADMIN_PROHIB;
689 code += PRC_TIMXCEED_INTRANS;
695 code = PRC_PARAMPROB;
698 case ICMP_SOURCEQUENCH:
701 if (discard_sourcequench)
706 * Problem with datagram; advise higher level routines.
708 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) ||
709 IP_VHL_HL(icp->icmp_ip.ip_vhl) < (sizeof(struct ip) >> 2)) {
710 icmpstat.icps_badlen++;
713 /* Discard ICMP's in response to multicast packets */
714 if (IN_MULTICAST(ntohl(icp->icmp_ip.ip_dst.s_addr)))
718 kprintf("deliver to protocol %d\n", icp->icmp_ip.ip_p);
720 icmpsrc.sin_addr = icp->icmp_ip.ip_dst;
725 if (code == PRC_MSGSIZE) {
726 /* Run MTU discovery in all netisrs */
727 if (icmp_mtudisc_start(m, hlen, proto)) {
728 /* Forwarded; done */
731 /* Move on; run rip_input() directly */
734 struct lwkt_port *port;
737 pr = &inetsw[ip_protox[icp->icmp_ip.ip_p]];
738 port = so_pr_ctlport(pr, code,
739 (struct sockaddr *)&icmpsrc, &icp->icmp_ip, &cpu);
741 if (cpu == netisr_ncpus) {
742 if (netisr_ncpus > 1) {
744 * Run pr_ctlinput in all
747 icmp_ctlinput_global_start(m,
752 * There is only one netisr; run
753 * pr_ctlinput directly.
755 } else if (cpu != mycpuid) {
757 * Send to the target netisr to run
760 icmp_ctlinput_start(m, port,
766 * The target netisr is this netisr.
768 * XXX if the packet contains [IPv4 AH TCP],
769 * we can't make a notification to TCP layer.
771 so_pr_ctlinput_direct(pr, code,
772 (struct sockaddr *)&icmpsrc, &icp->icmp_ip);
774 /* Move on; run rip_input() directly */
778 icmpstat.icps_badcode++;
783 && (m->m_flags & (M_MCAST | M_BCAST)) != 0) {
784 icmpstat.icps_bmcastecho++;
787 icp->icmp_type = ICMP_ECHOREPLY;
789 if (badport_bandlim(BANDLIM_ICMP_ECHO) < 0)
797 && (m->m_flags & (M_MCAST | M_BCAST)) != 0) {
798 icmpstat.icps_bmcasttstamp++;
801 if (icmplen < ICMP_TSLEN) {
802 icmpstat.icps_badlen++;
805 icp->icmp_type = ICMP_TSTAMPREPLY;
806 icp->icmp_rtime = iptime();
807 icp->icmp_ttime = icp->icmp_rtime; /* bogus, do later! */
809 if (badport_bandlim(BANDLIM_ICMP_TSTAMP) < 0)
816 if (icmpmaskrepl == 0)
819 * We are not able to respond with all ones broadcast
820 * unless we receive it over a point-to-point interface.
822 if (icmplen < ICMP_MASKLEN)
824 switch (ip->ip_dst.s_addr) {
826 case INADDR_BROADCAST:
828 icmpdst.sin_addr = ip->ip_src;
832 icmpdst.sin_addr = ip->ip_dst;
834 ia = (struct in_ifaddr *)ifaof_ifpforaddr(
835 (struct sockaddr *)&icmpdst, m->m_pkthdr.rcvif);
840 icp->icmp_type = ICMP_MASKREPLY;
841 icp->icmp_mask = ia->ia_sockmask.sin_addr.s_addr;
842 if (ip->ip_src.s_addr == 0) {
843 if (ia->ia_ifp->if_flags & IFF_BROADCAST)
844 ip->ip_src = satosin(&ia->ia_broadaddr)->sin_addr;
845 else if (ia->ia_ifp->if_flags & IFF_POINTOPOINT)
846 ip->ip_src = satosin(&ia->ia_dstaddr)->sin_addr;
849 ip->ip_len += hlen; /* since ip_input deducts this */
850 icmpstat.icps_reflect++;
851 icmpstat.icps_outhist[icp->icmp_type]++;
853 return(IPPROTO_DONE);
857 char src_buf[INET_ADDRSTRLEN];
858 char dst_buf[INET_ADDRSTRLEN];
859 char gwy_buf[INET_ADDRSTRLEN];
861 kprintf("icmp redirect from %s: %s => %s\n",
862 inet_ntop(AF_INET, &ip->ip_src,
863 src_buf, INET_ADDRSTRLEN),
864 inet_ntop(AF_INET, &icp->icmp_ip.ip_dst,
865 dst_buf, INET_ADDRSTRLEN),
866 inet_ntop(AF_INET, &icp->icmp_gwaddr,
867 gwy_buf, INET_ADDRSTRLEN));
873 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) ||
874 IP_VHL_HL(icp->icmp_ip.ip_vhl) < (sizeof(struct ip) >> 2)) {
875 icmpstat.icps_badlen++;
880 char dst_buf[INET_ADDRSTRLEN], gw_buf[INET_ADDRSTRLEN];
882 kprintf("redirect dst %s to %s\n",
883 inet_ntop(AF_INET, &icp->icmp_ip.ip_dst,
884 dst_buf, INET_ADDRSTRLEN),
885 inet_ntop(AF_INET, &icp->icmp_gwaddr,
886 gw_buf, INET_ADDRSTRLEN));
889 icmpsrc.sin_addr = icp->icmp_ip.ip_dst;
891 /* Run redirect in all netisrs */
892 if (icmp_redirect_start(m, hlen, proto)) {
893 /* Forwarded; done */
896 /* Move on; run rip_input() directly */
900 * No kernel processing for the following;
901 * just fall through to send to raw listener.
904 case ICMP_ROUTERADVERT:
905 case ICMP_ROUTERSOLICIT:
906 case ICMP_TSTAMPREPLY:
915 rip_input(mp, offp, proto);
916 return(IPPROTO_DONE);
920 return(IPPROTO_DONE);
924 * Reflect the ip packet back to the source
927 icmp_reflect(struct mbuf *m)
929 struct ip *ip = mtod(m, struct ip *);
930 struct in_ifaddr *ia;
931 struct in_ifaddr_container *iac;
932 struct ifaddr_container *ifac;
935 struct mbuf *opts = NULL;
936 int optlen = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip);
937 struct route *ro = NULL, rt;
939 if (!in_canforward(ip->ip_src) &&
940 ((ntohl(ip->ip_src.s_addr) & IN_CLASSA_NET) !=
941 (IN_LOOPBACKNET << IN_CLASSA_NSHIFT))) {
942 m_freem(m); /* Bad return address */
943 icmpstat.icps_badaddr++;
944 goto done; /* Ip_output() will check for broadcast */
947 ip->ip_dst = ip->ip_src;
950 bzero(ro, sizeof *ro);
953 * If the incoming packet was addressed directly to us,
954 * use dst as the src for the reply. Otherwise (broadcast
955 * or anonymous), use the address which corresponds
956 * to the incoming interface.
959 LIST_FOREACH(iac, INADDR_HASH(t.s_addr), ia_hash) {
960 if (t.s_addr == IA_SIN(iac->ia)->sin_addr.s_addr) {
965 ifp = m->m_pkthdr.rcvif;
966 if (ifp != NULL && (ifp->if_flags & IFF_BROADCAST)) {
967 TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
968 struct ifaddr *ifa = ifac->ifa;
970 if (ifa->ifa_addr->sa_family != AF_INET)
973 if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
979 * If the packet was transiting through us, use the address of
980 * the interface the packet came through in. If that interface
981 * doesn't have a suitable IP address, the normal selection
984 if (icmp_rfi && ifp != NULL) {
985 TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
986 struct ifaddr *ifa = ifac->ifa;
988 if (ifa->ifa_addr->sa_family != AF_INET)
995 * If the incoming packet was not addressed directly to us, use
996 * designated interface for icmp replies specified by sysctl
997 * net.inet.icmp.reply_src (default not set). Otherwise continue
998 * with normal source selection.
1000 if (icmp_reply_src[0] != '\0' &&
1001 (ifp = ifunit_netisr(icmp_reply_src))) {
1002 TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
1003 struct ifaddr *ifa = ifac->ifa;
1005 if (ifa->ifa_addr->sa_family != AF_INET)
1012 * If the packet was transiting through us, use the address of
1013 * the interface that is the closest to the packet source.
1014 * When we don't have a route back to the packet source, stop here
1015 * and drop the packet.
1017 ia = ip_rtaddr(ip->ip_dst, ro);
1020 icmpstat.icps_noroute++;
1024 t = IA_SIN(ia)->sin_addr;
1026 ip->ip_ttl = ip_defttl;
1034 * Retrieve any source routing from the incoming packet;
1035 * add on any record-route or timestamp options.
1037 cp = (u_char *) (ip + 1);
1038 if ((opts = ip_srcroute(m)) == NULL &&
1039 (opts = m_gethdr(M_NOWAIT, MT_HEADER))) {
1040 opts->m_len = sizeof(struct in_addr);
1041 mtod(opts, struct in_addr *)->s_addr = 0;
1046 kprintf("icmp_reflect optlen %d rt %d => ",
1047 optlen, opts->m_len);
1049 for (cnt = optlen; cnt > 0; cnt -= len, cp += len) {
1050 opt = cp[IPOPT_OPTVAL];
1051 if (opt == IPOPT_EOL)
1053 if (opt == IPOPT_NOP)
1056 if (cnt < IPOPT_OLEN + sizeof *cp)
1058 len = cp[IPOPT_OLEN];
1059 if (len < IPOPT_OLEN + sizeof *cp ||
1064 * Should check for overflow, but it
1067 if (opt == IPOPT_RR || opt == IPOPT_TS ||
1068 opt == IPOPT_SECURITY) {
1070 mtod(opts, caddr_t) + opts->m_len,
1075 /* Terminate & pad, if necessary */
1076 cnt = opts->m_len % 4;
1078 for (; cnt < 4; cnt++) {
1079 *(mtod(opts, caddr_t) + opts->m_len) =
1086 kprintf("%d\n", opts->m_len);
1090 * Now strip out original options by copying rest of first
1091 * mbuf's data back, and adjust the IP length.
1093 ip->ip_len -= optlen;
1094 ip->ip_vhl = IP_VHL_BORING;
1096 if (m->m_flags & M_PKTHDR)
1097 m->m_pkthdr.len -= optlen;
1098 optlen += sizeof(struct ip);
1099 bcopy((caddr_t)ip + optlen, ip + 1,
1100 m->m_len - sizeof(struct ip));
1102 m->m_pkthdr.fw_flags &= FW_MBUF_GENERATED;
1103 m->m_flags &= ~(M_BCAST|M_MCAST);
1104 icmp_send(m, opts, ro);
1108 if (ro && ro->ro_rt)
1113 * Send an icmp packet back to the ip level,
1114 * after supplying a checksum.
1117 icmp_send(struct mbuf *m, struct mbuf *opts, struct route *rt)
1119 struct ip *ip = mtod(m, struct ip *);
1123 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
1126 icp = mtod(m, struct icmp *);
1127 icp->icmp_cksum = 0;
1128 icp->icmp_cksum = in_cksum(m, ip->ip_len - hlen);
1131 m->m_pkthdr.rcvif = NULL;
1134 char dst_buf[INET_ADDRSTRLEN], src_buf[INET_ADDRSTRLEN];
1136 kprintf("icmp_send dst %s src %s\n",
1137 inet_ntop(AF_INET, &ip->ip_dst, dst_buf, INET_ADDRSTRLEN),
1138 inet_ntop(AF_INET, &ip->ip_src, src_buf, INET_ADDRSTRLEN));
1141 ip_output(m, opts, rt, 0, NULL, NULL);
1151 t = (atv.tv_sec % (24*60*60)) * 1000 + atv.tv_usec / 1000;
1157 * Return the next larger or smaller MTU plateau (table from RFC 1191)
1158 * given current value MTU. If DIR is less than zero, a larger plateau
1159 * is returned; otherwise, a smaller value is returned.
1162 ip_next_mtu(int mtu, int dir)
1164 static int mtutab[] = {
1165 65535, 32000, 17914, 8166, 4352, 2002, 1492, 1006, 508, 296,
1170 for (i = 0; i < (sizeof mtutab) / (sizeof mtutab[0]); i++) {
1171 if (mtu >= mtutab[i])
1179 return mtutab[i - 1];
1182 if (mtutab[i] == 0) {
1184 } else if(mtu > mtutab[i]) {
1187 return mtutab[i + 1];
1195 * badport_bandlim() - check for ICMP bandwidth limit
1197 * Return 0 if it is ok to send an ICMP error response, -1 if we have
1198 * hit our bandwidth limit and it is not ok.
1200 * If icmplim is <= 0, the feature is disabled and 0 is returned.
1202 * For now we separate the TCP and UDP subsystems w/ different 'which'
1203 * values. We may eventually remove this separation (and simplify the
1206 * Note that the printing of the error message is delayed so we can
1207 * properly print the icmp error rate that the system was trying to do
1208 * (i.e. 22000/100 pps, etc...). This can cause long delays in printing
1209 * the 'final' error, but it doesn't make sense to solve the printing
1210 * delay with more complex code.
1213 badport_bandlim(int which)
1215 static int lticks[BANDLIM_MAX + 1];
1216 static int lpackets[BANDLIM_MAX + 1];
1218 const char *bandlimittype[] = {
1219 "Limiting icmp unreach response",
1220 "Limiting icmp ping response",
1221 "Limiting icmp tstamp response",
1222 "Limiting closed port RST response",
1223 "Limiting open port RST response"
1227 * Return ok status if feature disabled or argument out of
1231 if (icmplim <= 0 || which > BANDLIM_MAX || which < 0)
1233 dticks = ticks - lticks[which];
1236 * reset stats when cumulative dt exceeds one second.
1239 if ((unsigned int)dticks > hz) {
1240 if (lpackets[which] > icmplim && icmplim_output) {
1241 kprintf("%s from %d to %d packets per second\n",
1242 bandlimittype[which],
1247 lticks[which] = ticks;
1248 lpackets[which] = 0;
1255 if (++lpackets[which] > icmplim) {