1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1982, 1986, 1988, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include "opt_inet.h"
33
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/mbuf.h>
37 #include <sys/protosw.h>
38 #include <sys/socket.h>
39 #include <sys/time.h>
40 #include <sys/kernel.h>
41 #include <sys/lock.h>
42 #include <sys/sysctl.h>
43 #include <sys/syslog.h>
44
45 #include <net/if.h>
46 #include <net/if_var.h>
47 #include <net/if_private.h>
48 #include <net/if_types.h>
49 #include <net/route.h>
50 #include <net/route/route_ctl.h>
51 #include <net/route/nhop.h>
52 #include <net/vnet.h>
53
54 #include <netinet/in.h>
55 #include <netinet/in_fib.h>
56 #include <netinet/in_pcb.h>
57 #include <netinet/in_systm.h>
58 #include <netinet/in_var.h>
59 #include <netinet/ip.h>
60 #include <netinet/ip_icmp.h>
61 #include <netinet/ip_var.h>
62 #include <netinet/ip_options.h>
63 #include <netinet/sctp.h>
64 #include <netinet/tcp.h>
65 #include <netinet/tcpip.h>
66 #include <netinet/icmp_var.h>
67
68 #ifdef INET
69
70 #include <machine/in_cksum.h>
71
72 #include <security/mac/mac_framework.h>
73 #endif /* INET */
74
75 extern ipproto_ctlinput_t *ip_ctlprotox[];
76
77 /*
78 * ICMP routines: error generation, receive packet processing, and
79 * routines to turnaround packets back to the originator, and
80 * host table maintenance routines.
81 */
82 static int sysctl_icmplim_and_jitter(SYSCTL_HANDLER_ARGS);
83 VNET_DEFINE_STATIC(u_int, icmplim) = 200;
84 #define V_icmplim VNET(icmplim)
85 SYSCTL_PROC(_net_inet_icmp, ICMPCTL_ICMPLIM, icmplim, CTLTYPE_UINT |
86 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(icmplim), 0,
87 &sysctl_icmplim_and_jitter, "IU",
88 "Maximum number of ICMP responses per second");
89
90 VNET_DEFINE_STATIC(int, icmplim_curr_jitter[BANDLIM_MAX]) = {0};
91 #define V_icmplim_curr_jitter VNET(icmplim_curr_jitter)
92 VNET_DEFINE_STATIC(u_int, icmplim_jitter) = 16;
93 #define V_icmplim_jitter VNET(icmplim_jitter)
94 SYSCTL_PROC(_net_inet_icmp, OID_AUTO, icmplim_jitter, CTLTYPE_UINT |
95 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(icmplim_jitter), 0,
96 &sysctl_icmplim_and_jitter, "IU",
97 "Random icmplim jitter adjustment limit");
98
99 VNET_DEFINE_STATIC(int, icmplim_output) = 1;
100 #define V_icmplim_output VNET(icmplim_output)
101 SYSCTL_INT(_net_inet_icmp, OID_AUTO, icmplim_output, CTLFLAG_VNET | CTLFLAG_RW,
102 &VNET_NAME(icmplim_output), 0,
103 "Enable logging of ICMP response rate limiting");
104
105 #ifdef INET
106 VNET_PCPUSTAT_DEFINE(struct icmpstat, icmpstat);
107 VNET_PCPUSTAT_SYSINIT(icmpstat);
108 SYSCTL_VNET_PCPUSTAT(_net_inet_icmp, ICMPCTL_STATS, stats, struct icmpstat,
109 icmpstat, "ICMP statistics (struct icmpstat, netinet/icmp_var.h)");
110
111 #ifdef VIMAGE
112 VNET_PCPUSTAT_SYSUNINIT(icmpstat);
113 #endif /* VIMAGE */
114
115 VNET_DEFINE_STATIC(int, icmpmaskrepl) = 0;
116 #define V_icmpmaskrepl VNET(icmpmaskrepl)
117 SYSCTL_INT(_net_inet_icmp, ICMPCTL_MASKREPL, maskrepl, CTLFLAG_VNET | CTLFLAG_RW,
118 &VNET_NAME(icmpmaskrepl), 0,
119 "Reply to ICMP Address Mask Request packets");
120
121 VNET_DEFINE_STATIC(u_int, icmpmaskfake) = 0;
122 #define V_icmpmaskfake VNET(icmpmaskfake)
123 SYSCTL_UINT(_net_inet_icmp, OID_AUTO, maskfake, CTLFLAG_VNET | CTLFLAG_RW,
124 &VNET_NAME(icmpmaskfake), 0,
125 "Fake reply to ICMP Address Mask Request packets");
126
127 VNET_DEFINE(int, drop_redirect) = 0;
128 #define V_drop_redirect VNET(drop_redirect)
129 SYSCTL_INT(_net_inet_icmp, OID_AUTO, drop_redirect, CTLFLAG_VNET | CTLFLAG_RW,
130 &VNET_NAME(drop_redirect), 0,
131 "Ignore ICMP redirects");
132
133 VNET_DEFINE_STATIC(int, log_redirect) = 0;
134 #define V_log_redirect VNET(log_redirect)
135 SYSCTL_INT(_net_inet_icmp, OID_AUTO, log_redirect, CTLFLAG_VNET | CTLFLAG_RW,
136 &VNET_NAME(log_redirect), 0,
137 "Log ICMP redirects to the console");
138
139 VNET_DEFINE_STATIC(int, redirtimeout) = 60 * 10; /* 10 minutes */
140 #define V_redirtimeout VNET(redirtimeout)
141 SYSCTL_INT(_net_inet_icmp, OID_AUTO, redirtimeout, CTLFLAG_VNET | CTLFLAG_RW,
142 &VNET_NAME(redirtimeout), 0,
143 "Delay in seconds before expiring redirect route");
144
145 VNET_DEFINE_STATIC(char, reply_src[IFNAMSIZ]);
146 #define V_reply_src VNET(reply_src)
147 SYSCTL_STRING(_net_inet_icmp, OID_AUTO, reply_src, CTLFLAG_VNET | CTLFLAG_RW,
148 &VNET_NAME(reply_src), IFNAMSIZ,
149 "ICMP reply source for non-local packets");
150
151 VNET_DEFINE_STATIC(int, icmp_rfi) = 0;
152 #define V_icmp_rfi VNET(icmp_rfi)
153 SYSCTL_INT(_net_inet_icmp, OID_AUTO, reply_from_interface, CTLFLAG_VNET | CTLFLAG_RW,
154 &VNET_NAME(icmp_rfi), 0,
155 "ICMP reply from incoming interface for non-local packets");
156 /* Router requirements RFC 1812 section 4.3.2.3 requires 576 - 28. */
157 VNET_DEFINE_STATIC(int, icmp_quotelen) = 548;
158 #define V_icmp_quotelen VNET(icmp_quotelen)
159 SYSCTL_INT(_net_inet_icmp, OID_AUTO, quotelen, CTLFLAG_VNET | CTLFLAG_RW,
160 &VNET_NAME(icmp_quotelen), 0,
161 "Number of bytes from original packet to quote in ICMP reply");
162
163 VNET_DEFINE_STATIC(int, icmpbmcastecho) = 0;
164 #define V_icmpbmcastecho VNET(icmpbmcastecho)
165 SYSCTL_INT(_net_inet_icmp, OID_AUTO, bmcastecho, CTLFLAG_VNET | CTLFLAG_RW,
166 &VNET_NAME(icmpbmcastecho), 0,
167 "Reply to multicast ICMP Echo Request and Timestamp packets");
168
169 VNET_DEFINE_STATIC(int, icmptstamprepl) = 1;
170 #define V_icmptstamprepl VNET(icmptstamprepl)
171 SYSCTL_INT(_net_inet_icmp, OID_AUTO, tstamprepl, CTLFLAG_VNET | CTLFLAG_RW,
172 &VNET_NAME(icmptstamprepl), 0,
173 "Respond to ICMP Timestamp packets");
174
175 VNET_DEFINE_STATIC(int, error_keeptags) = 0;
176 #define V_error_keeptags VNET(error_keeptags)
177 SYSCTL_INT(_net_inet_icmp, OID_AUTO, error_keeptags, CTLFLAG_VNET | CTLFLAG_RW,
178 &VNET_NAME(error_keeptags), 0,
179 "ICMP error response keeps copy of mbuf_tags of original packet");
180
181 #ifdef ICMPPRINTFS
182 int icmpprintfs = 0;
183 #endif
184
185 static void icmp_reflect(struct mbuf *);
186 static void icmp_send(struct mbuf *, struct mbuf *);
187 static int icmp_verify_redirect_gateway(struct sockaddr_in *,
188 struct sockaddr_in *, struct sockaddr_in *, u_int);
189
190 /*
191 * Kernel module interface for updating icmpstat. The argument is an index
192 * into icmpstat treated as an array of u_long. While this encodes the
193 * general layout of icmpstat into the caller, it doesn't encode its
194 * location, so that future changes to add, for example, per-CPU stats
195 * support won't cause binary compatibility problems for kernel modules.
196 */
197 void
kmod_icmpstat_inc(int statnum)198 kmod_icmpstat_inc(int statnum)
199 {
200
201 counter_u64_add(VNET(icmpstat)[statnum], 1);
202 }
203
204 /*
205 * Generate an error packet of type error
206 * in response to bad packet ip.
207 */
208 void
icmp_error(struct mbuf * n,int type,int code,uint32_t dest,int mtu)209 icmp_error(struct mbuf *n, int type, int code, uint32_t dest, int mtu)
210 {
211 struct ip *oip, *nip;
212 struct icmp *icp;
213 struct mbuf *m;
214 unsigned icmplen, icmpelen, nlen, oiphlen;
215
216 KASSERT((u_int)type <= ICMP_MAXTYPE, ("%s: illegal ICMP type",
217 __func__));
218
219 if (type != ICMP_REDIRECT)
220 ICMPSTAT_INC(icps_error);
221 /*
222 * Don't send error:
223 * if the original packet was encrypted.
224 * if not the first fragment of message.
225 * in response to a multicast or broadcast packet.
226 * if the old packet protocol was an ICMP error message.
227 */
228 if (n->m_flags & M_DECRYPTED)
229 goto freeit;
230 if (n->m_flags & (M_BCAST|M_MCAST))
231 goto freeit;
232
233 /* Drop if IP header plus 8 bytes is not contiguous in first mbuf. */
234 if (n->m_len < sizeof(struct ip) + ICMP_MINLEN)
235 goto freeit;
236 oip = mtod(n, struct ip *);
237 oiphlen = oip->ip_hl << 2;
238 if (n->m_len < oiphlen + ICMP_MINLEN)
239 goto freeit;
240 #ifdef ICMPPRINTFS
241 if (icmpprintfs)
242 printf("icmp_error(%p, %x, %d)\n", oip, type, code);
243 #endif
244 if (oip->ip_off & htons(~(IP_MF|IP_DF)))
245 goto freeit;
246 if (oip->ip_p == IPPROTO_ICMP && type != ICMP_REDIRECT &&
247 !ICMP_INFOTYPE(((struct icmp *)((caddr_t)oip +
248 oiphlen))->icmp_type)) {
249 ICMPSTAT_INC(icps_oldicmp);
250 goto freeit;
251 }
252 /*
253 * Calculate length to quote from original packet and
254 * prevent the ICMP mbuf from overflowing.
255 * Unfortunately this is non-trivial since ip_forward()
256 * sends us truncated packets.
257 */
258 nlen = m_length(n, NULL);
259 if (oip->ip_p == IPPROTO_TCP) {
260 struct tcphdr *th;
261 int tcphlen;
262
263 if (oiphlen + sizeof(struct tcphdr) > n->m_len &&
264 n->m_next == NULL)
265 goto stdreply;
266 if (n->m_len < oiphlen + sizeof(struct tcphdr) &&
267 (n = m_pullup(n, oiphlen + sizeof(struct tcphdr))) == NULL)
268 goto freeit;
269 oip = mtod(n, struct ip *);
270 th = mtodo(n, oiphlen);
271 tcphlen = th->th_off << 2;
272 if (tcphlen < sizeof(struct tcphdr))
273 goto freeit;
274 if (ntohs(oip->ip_len) < oiphlen + tcphlen)
275 goto freeit;
276 if (oiphlen + tcphlen > n->m_len && n->m_next == NULL)
277 goto stdreply;
278 if (n->m_len < oiphlen + tcphlen &&
279 (n = m_pullup(n, oiphlen + tcphlen)) == NULL)
280 goto freeit;
281 oip = mtod(n, struct ip *);
282 icmpelen = max(tcphlen, min(V_icmp_quotelen,
283 ntohs(oip->ip_len) - oiphlen));
284 } else if (oip->ip_p == IPPROTO_SCTP) {
285 struct sctphdr *sh;
286 struct sctp_chunkhdr *ch;
287
288 if (ntohs(oip->ip_len) < oiphlen + sizeof(struct sctphdr))
289 goto stdreply;
290 if (oiphlen + sizeof(struct sctphdr) > n->m_len &&
291 n->m_next == NULL)
292 goto stdreply;
293 if (n->m_len < oiphlen + sizeof(struct sctphdr) &&
294 (n = m_pullup(n, oiphlen + sizeof(struct sctphdr))) == NULL)
295 goto freeit;
296 oip = mtod(n, struct ip *);
297 icmpelen = max(sizeof(struct sctphdr),
298 min(V_icmp_quotelen, ntohs(oip->ip_len) - oiphlen));
299 sh = mtodo(n, oiphlen);
300 if (ntohl(sh->v_tag) == 0 &&
301 ntohs(oip->ip_len) >= oiphlen +
302 sizeof(struct sctphdr) + 8 &&
303 (n->m_len >= oiphlen + sizeof(struct sctphdr) + 8 ||
304 n->m_next != NULL)) {
305 if (n->m_len < oiphlen + sizeof(struct sctphdr) + 8 &&
306 (n = m_pullup(n, oiphlen +
307 sizeof(struct sctphdr) + 8)) == NULL)
308 goto freeit;
309 oip = mtod(n, struct ip *);
310 sh = mtodo(n, oiphlen);
311 ch = (struct sctp_chunkhdr *)(sh + 1);
312 if (ch->chunk_type == SCTP_INITIATION) {
313 icmpelen = max(sizeof(struct sctphdr) + 8,
314 min(V_icmp_quotelen, ntohs(oip->ip_len) -
315 oiphlen));
316 }
317 }
318 } else
319 stdreply: icmpelen = max(8, min(V_icmp_quotelen, ntohs(oip->ip_len) -
320 oiphlen));
321
322 icmplen = min(oiphlen + icmpelen, nlen);
323 if (icmplen < sizeof(struct ip))
324 goto freeit;
325
326 if (MHLEN > sizeof(struct ip) + ICMP_MINLEN + icmplen)
327 m = m_gethdr(M_NOWAIT, MT_DATA);
328 else
329 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
330 if (m == NULL)
331 goto freeit;
332 #ifdef MAC
333 mac_netinet_icmp_reply(n, m);
334 #endif
335 icmplen = min(icmplen, M_TRAILINGSPACE(m) -
336 sizeof(struct ip) - ICMP_MINLEN);
337 m_align(m, sizeof(struct ip) + ICMP_MINLEN + icmplen);
338 m->m_data += sizeof(struct ip);
339 m->m_len = ICMP_MINLEN + icmplen;
340
341 /* XXX MRT make the outgoing packet use the same FIB
342 * that was associated with the incoming packet
343 */
344 M_SETFIB(m, M_GETFIB(n));
345 icp = mtod(m, struct icmp *);
346 ICMPSTAT_INC2(icps_outhist, type);
347 icp->icmp_type = type;
348 if (type == ICMP_REDIRECT)
349 icp->icmp_gwaddr.s_addr = dest;
350 else {
351 icp->icmp_void = 0;
352 /*
353 * The following assignments assume an overlay with the
354 * just zeroed icmp_void field.
355 */
356 if (type == ICMP_PARAMPROB) {
357 icp->icmp_pptr = code;
358 code = 0;
359 } else if (type == ICMP_UNREACH &&
360 code == ICMP_UNREACH_NEEDFRAG && mtu) {
361 icp->icmp_nextmtu = htons(mtu);
362 }
363 }
364 icp->icmp_code = code;
365
366 /*
367 * Copy the quotation into ICMP message and
368 * convert quoted IP header back to network representation.
369 */
370 m_copydata(n, 0, icmplen, (caddr_t)&icp->icmp_ip);
371 nip = &icp->icmp_ip;
372
373 /*
374 * Set up ICMP message mbuf and copy old IP header (without options
375 * in front of ICMP message.
376 * If the original mbuf was meant to bypass the firewall, the error
377 * reply should bypass as well.
378 */
379 m->m_flags |= n->m_flags & M_SKIP_FIREWALL;
380 KASSERT(M_LEADINGSPACE(m) >= sizeof(struct ip),
381 ("insufficient space for ip header"));
382 m->m_data -= sizeof(struct ip);
383 m->m_len += sizeof(struct ip);
384 m->m_pkthdr.len = m->m_len;
385 m->m_pkthdr.rcvif = n->m_pkthdr.rcvif;
386 nip = mtod(m, struct ip *);
387 bcopy((caddr_t)oip, (caddr_t)nip, sizeof(struct ip));
388 nip->ip_len = htons(m->m_len);
389 nip->ip_v = IPVERSION;
390 nip->ip_hl = 5;
391 nip->ip_p = IPPROTO_ICMP;
392 nip->ip_tos = 0;
393
394 if (V_error_keeptags)
395 m_tag_copy_chain(m, n, M_NOWAIT);
396
397 icmp_reflect(m);
398
399 freeit:
400 m_freem(n);
401 }
402
403 int
icmp_errmap(const struct icmp * icp)404 icmp_errmap(const struct icmp *icp)
405 {
406
407 switch (icp->icmp_type) {
408 case ICMP_UNREACH:
409 switch (icp->icmp_code) {
410 case ICMP_UNREACH_NET:
411 case ICMP_UNREACH_HOST:
412 case ICMP_UNREACH_SRCFAIL:
413 case ICMP_UNREACH_NET_UNKNOWN:
414 case ICMP_UNREACH_HOST_UNKNOWN:
415 case ICMP_UNREACH_ISOLATED:
416 case ICMP_UNREACH_TOSNET:
417 case ICMP_UNREACH_TOSHOST:
418 case ICMP_UNREACH_HOST_PRECEDENCE:
419 case ICMP_UNREACH_PRECEDENCE_CUTOFF:
420 return (EHOSTUNREACH);
421 case ICMP_UNREACH_NEEDFRAG:
422 return (EMSGSIZE);
423 case ICMP_UNREACH_PROTOCOL:
424 case ICMP_UNREACH_PORT:
425 case ICMP_UNREACH_NET_PROHIB:
426 case ICMP_UNREACH_HOST_PROHIB:
427 case ICMP_UNREACH_FILTER_PROHIB:
428 return (ECONNREFUSED);
429 default:
430 return (0);
431 }
432 case ICMP_TIMXCEED:
433 switch (icp->icmp_code) {
434 case ICMP_TIMXCEED_INTRANS:
435 return (EHOSTUNREACH);
436 default:
437 return (0);
438 }
439 case ICMP_PARAMPROB:
440 switch (icp->icmp_code) {
441 case ICMP_PARAMPROB_ERRATPTR:
442 case ICMP_PARAMPROB_OPTABSENT:
443 return (ENOPROTOOPT);
444 default:
445 return (0);
446 }
447 default:
448 return (0);
449 }
450 }
451
452 /*
453 * Process a received ICMP message.
454 */
455 int
icmp_input(struct mbuf ** mp,int * offp,int proto)456 icmp_input(struct mbuf **mp, int *offp, int proto)
457 {
458 struct icmp *icp;
459 struct in_ifaddr *ia;
460 struct mbuf *m = *mp;
461 struct ip *ip = mtod(m, struct ip *);
462 struct sockaddr_in icmpsrc, icmpdst, icmpgw;
463 int hlen = *offp;
464 int icmplen = ntohs(ip->ip_len) - *offp;
465 int i, code;
466 int fibnum;
467
468 NET_EPOCH_ASSERT();
469
470 *mp = NULL;
471
472 /*
473 * Locate icmp structure in mbuf, and check
474 * that not corrupted and of at least minimum length.
475 */
476 #ifdef ICMPPRINTFS
477 if (icmpprintfs) {
478 char srcbuf[INET_ADDRSTRLEN];
479 char dstbuf[INET_ADDRSTRLEN];
480
481 printf("icmp_input from %s to %s, len %d\n",
482 inet_ntoa_r(ip->ip_src, srcbuf),
483 inet_ntoa_r(ip->ip_dst, dstbuf), icmplen);
484 }
485 #endif
486 if (icmplen < ICMP_MINLEN) {
487 ICMPSTAT_INC(icps_tooshort);
488 goto freeit;
489 }
490 i = hlen + min(icmplen, ICMP_ADVLENMIN);
491 if (m->m_len < i && (m = m_pullup(m, i)) == NULL) {
492 ICMPSTAT_INC(icps_tooshort);
493 return (IPPROTO_DONE);
494 }
495 ip = mtod(m, struct ip *);
496 m->m_len -= hlen;
497 m->m_data += hlen;
498 icp = mtod(m, struct icmp *);
499 if (in_cksum(m, icmplen)) {
500 ICMPSTAT_INC(icps_checksum);
501 goto freeit;
502 }
503 m->m_len += hlen;
504 m->m_data -= hlen;
505
506 #ifdef ICMPPRINTFS
507 if (icmpprintfs)
508 printf("icmp_input, type %d code %d\n", icp->icmp_type,
509 icp->icmp_code);
510 #endif
511
512 /*
513 * Message type specific processing.
514 */
515 if (icp->icmp_type > ICMP_MAXTYPE)
516 goto raw;
517
518 /* Initialize */
519 bzero(&icmpsrc, sizeof(icmpsrc));
520 icmpsrc.sin_len = sizeof(struct sockaddr_in);
521 icmpsrc.sin_family = AF_INET;
522 bzero(&icmpdst, sizeof(icmpdst));
523 icmpdst.sin_len = sizeof(struct sockaddr_in);
524 icmpdst.sin_family = AF_INET;
525 bzero(&icmpgw, sizeof(icmpgw));
526 icmpgw.sin_len = sizeof(struct sockaddr_in);
527 icmpgw.sin_family = AF_INET;
528
529 ICMPSTAT_INC2(icps_inhist, icp->icmp_type);
530 code = icp->icmp_code;
531 switch (icp->icmp_type) {
532 case ICMP_UNREACH:
533 if (code > ICMP_UNREACH_PRECEDENCE_CUTOFF)
534 goto badcode;
535 else
536 goto deliver;
537
538 case ICMP_TIMXCEED:
539 if (code > ICMP_TIMXCEED_REASS)
540 goto badcode;
541 else
542 goto deliver;
543
544 case ICMP_PARAMPROB:
545 if (code > ICMP_PARAMPROB_LENGTH)
546 goto badcode;
547
548 deliver:
549 /*
550 * Problem with datagram; advise higher level routines.
551 */
552 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) ||
553 icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) {
554 ICMPSTAT_INC(icps_badlen);
555 goto freeit;
556 }
557 /* Discard ICMP's in response to multicast packets */
558 if (IN_MULTICAST(ntohl(icp->icmp_ip.ip_dst.s_addr)))
559 goto badcode;
560 /* Filter out responses to INADDR_ANY, protocols ignore it. */
561 if (icp->icmp_ip.ip_dst.s_addr == INADDR_ANY ||
562 icp->icmp_ip.ip_src.s_addr == INADDR_ANY)
563 goto freeit;
564 #ifdef ICMPPRINTFS
565 if (icmpprintfs)
566 printf("deliver to protocol %d\n", icp->icmp_ip.ip_p);
567 #endif
568 /*
569 * XXX if the packet contains [IPv4 AH TCP], we can't make a
570 * notification to TCP layer.
571 */
572 i = sizeof(struct ip) + min(icmplen, ICMP_ADVLENPREF(icp));
573 ip_stripoptions(m);
574 if (m->m_len < i && (m = m_pullup(m, i)) == NULL) {
575 /* This should actually not happen */
576 ICMPSTAT_INC(icps_tooshort);
577 return (IPPROTO_DONE);
578 }
579 ip = mtod(m, struct ip *);
580 icp = (struct icmp *)(ip + 1);
581 /*
582 * The upper layer handler can rely on:
583 * - The outer IP header has no options.
584 * - The outer IP header, the ICMP header, the inner IP header,
585 * and the first n bytes of the inner payload are contiguous.
586 * n is at least 8, but might be larger based on
587 * ICMP_ADVLENPREF. See its definition in ip_icmp.h.
588 */
589 if (ip_ctlprotox[icp->icmp_ip.ip_p] != NULL)
590 ip_ctlprotox[icp->icmp_ip.ip_p](icp);
591 break;
592
593 badcode:
594 ICMPSTAT_INC(icps_badcode);
595 break;
596
597 case ICMP_ECHO:
598 if (!V_icmpbmcastecho
599 && (m->m_flags & (M_MCAST | M_BCAST)) != 0) {
600 ICMPSTAT_INC(icps_bmcastecho);
601 break;
602 }
603 if (badport_bandlim(BANDLIM_ICMP_ECHO) < 0)
604 goto freeit;
605 icp->icmp_type = ICMP_ECHOREPLY;
606 goto reflect;
607
608 case ICMP_TSTAMP:
609 if (V_icmptstamprepl == 0)
610 break;
611 if (!V_icmpbmcastecho
612 && (m->m_flags & (M_MCAST | M_BCAST)) != 0) {
613 ICMPSTAT_INC(icps_bmcasttstamp);
614 break;
615 }
616 if (icmplen < ICMP_TSLEN) {
617 ICMPSTAT_INC(icps_badlen);
618 break;
619 }
620 if (badport_bandlim(BANDLIM_ICMP_TSTAMP) < 0)
621 goto freeit;
622 icp->icmp_type = ICMP_TSTAMPREPLY;
623 icp->icmp_rtime = iptime();
624 icp->icmp_ttime = icp->icmp_rtime; /* bogus, do later! */
625 goto reflect;
626
627 case ICMP_MASKREQ:
628 if (V_icmpmaskrepl == 0)
629 break;
630 /*
631 * We are not able to respond with all ones broadcast
632 * unless we receive it over a point-to-point interface.
633 */
634 if (icmplen < ICMP_MASKLEN)
635 break;
636 if (in_broadcast(ip->ip_dst))
637 icmpdst.sin_addr = ip->ip_src;
638 else
639 icmpdst.sin_addr = ip->ip_dst;
640 ia = (struct in_ifaddr *)ifaof_ifpforaddr(
641 (struct sockaddr *)&icmpdst, m->m_pkthdr.rcvif);
642 if (ia == NULL)
643 break;
644 if (ia->ia_ifp == NULL)
645 break;
646 icp->icmp_type = ICMP_MASKREPLY;
647 if (V_icmpmaskfake == 0)
648 icp->icmp_mask = ia->ia_sockmask.sin_addr.s_addr;
649 else
650 icp->icmp_mask = V_icmpmaskfake;
651 if (ip->ip_src.s_addr == 0) {
652 if (ia->ia_ifp->if_flags & IFF_BROADCAST)
653 ip->ip_src = satosin(&ia->ia_broadaddr)->sin_addr;
654 else if (ia->ia_ifp->if_flags & IFF_POINTOPOINT)
655 ip->ip_src = satosin(&ia->ia_dstaddr)->sin_addr;
656 }
657 reflect:
658 ICMPSTAT_INC(icps_reflect);
659 ICMPSTAT_INC2(icps_outhist, icp->icmp_type);
660 icmp_reflect(m);
661 return (IPPROTO_DONE);
662
663 case ICMP_REDIRECT:
664 if (V_log_redirect) {
665 u_long src, dst, gw;
666
667 src = ntohl(ip->ip_src.s_addr);
668 dst = ntohl(icp->icmp_ip.ip_dst.s_addr);
669 gw = ntohl(icp->icmp_gwaddr.s_addr);
670 printf("icmp redirect from %d.%d.%d.%d: "
671 "%d.%d.%d.%d => %d.%d.%d.%d\n",
672 (int)(src >> 24), (int)((src >> 16) & 0xff),
673 (int)((src >> 8) & 0xff), (int)(src & 0xff),
674 (int)(dst >> 24), (int)((dst >> 16) & 0xff),
675 (int)((dst >> 8) & 0xff), (int)(dst & 0xff),
676 (int)(gw >> 24), (int)((gw >> 16) & 0xff),
677 (int)((gw >> 8) & 0xff), (int)(gw & 0xff));
678 }
679 /*
680 * RFC1812 says we must ignore ICMP redirects if we
681 * are acting as router.
682 */
683 if (V_drop_redirect || V_ipforwarding)
684 break;
685 if (code > 3)
686 goto badcode;
687 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) ||
688 icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) {
689 ICMPSTAT_INC(icps_badlen);
690 break;
691 }
692 /*
693 * Short circuit routing redirects to force
694 * immediate change in the kernel's routing
695 * tables. The message is also handed to anyone
696 * listening on a raw socket (e.g. the routing
697 * daemon for use in updating its tables).
698 */
699 icmpgw.sin_addr = ip->ip_src;
700 icmpdst.sin_addr = icp->icmp_gwaddr;
701 #ifdef ICMPPRINTFS
702 if (icmpprintfs) {
703 char dstbuf[INET_ADDRSTRLEN];
704 char gwbuf[INET_ADDRSTRLEN];
705
706 printf("redirect dst %s to %s\n",
707 inet_ntoa_r(icp->icmp_ip.ip_dst, dstbuf),
708 inet_ntoa_r(icp->icmp_gwaddr, gwbuf));
709 }
710 #endif
711 icmpsrc.sin_addr = icp->icmp_ip.ip_dst;
712
713 /*
714 * RFC 1122 says network (code 0,2) redirects SHOULD
715 * be treated identically to the host redirects.
716 * Given that, ignore network masks.
717 */
718
719 /*
720 * Variable values:
721 * icmpsrc: route destination
722 * icmpdst: route gateway
723 * icmpgw: message source
724 */
725
726 if (icmp_verify_redirect_gateway(&icmpgw, &icmpsrc, &icmpdst,
727 M_GETFIB(m)) != 0) {
728 /* TODO: increment bad redirects here */
729 break;
730 }
731
732 for ( fibnum = 0; fibnum < rt_numfibs; fibnum++) {
733 rib_add_redirect(fibnum, (struct sockaddr *)&icmpsrc,
734 (struct sockaddr *)&icmpdst,
735 (struct sockaddr *)&icmpgw, m->m_pkthdr.rcvif,
736 RTF_GATEWAY, V_redirtimeout);
737 }
738 break;
739
740 /*
741 * No kernel processing for the following;
742 * just fall through to send to raw listener.
743 */
744 case ICMP_ECHOREPLY:
745 case ICMP_ROUTERADVERT:
746 case ICMP_ROUTERSOLICIT:
747 case ICMP_TSTAMPREPLY:
748 case ICMP_IREQREPLY:
749 case ICMP_MASKREPLY:
750 case ICMP_SOURCEQUENCH:
751 default:
752 break;
753 }
754
755 raw:
756 *mp = m;
757 rip_input(mp, offp, proto);
758 return (IPPROTO_DONE);
759
760 freeit:
761 m_freem(m);
762 return (IPPROTO_DONE);
763 }
764
765 /*
766 * Reflect the ip packet back to the source
767 */
768 static void
icmp_reflect(struct mbuf * m)769 icmp_reflect(struct mbuf *m)
770 {
771 struct ip *ip = mtod(m, struct ip *);
772 struct ifaddr *ifa;
773 struct ifnet *ifp;
774 struct in_ifaddr *ia;
775 struct in_addr t;
776 struct nhop_object *nh;
777 struct mbuf *opts = NULL;
778 int optlen = (ip->ip_hl << 2) - sizeof(struct ip);
779
780 NET_EPOCH_ASSERT();
781
782 if (IN_MULTICAST(ntohl(ip->ip_src.s_addr)) ||
783 (IN_EXPERIMENTAL(ntohl(ip->ip_src.s_addr)) && !V_ip_allow_net240) ||
784 (IN_ZERONET(ntohl(ip->ip_src.s_addr)) && !V_ip_allow_net0) ||
785 in_nullhost(ip->ip_src) ) {
786 m_freem(m); /* Bad return address */
787 ICMPSTAT_INC(icps_badaddr);
788 goto done; /* ip_output() will check for broadcast */
789 }
790
791 t = ip->ip_dst;
792 ip->ip_dst = ip->ip_src;
793
794 /*
795 * Source selection for ICMP replies:
796 *
797 * If the incoming packet was addressed directly to one of our
798 * own addresses, use dst as the src for the reply.
799 */
800 CK_LIST_FOREACH(ia, INADDR_HASH(t.s_addr), ia_hash) {
801 if (t.s_addr == IA_SIN(ia)->sin_addr.s_addr) {
802 t = IA_SIN(ia)->sin_addr;
803 goto match;
804 }
805 }
806
807 /*
808 * If the incoming packet was addressed to one of our broadcast
809 * addresses, use the first non-broadcast address which corresponds
810 * to the incoming interface.
811 */
812 ifp = m->m_pkthdr.rcvif;
813 if (ifp != NULL && ifp->if_flags & IFF_BROADCAST) {
814 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
815 if (ifa->ifa_addr->sa_family != AF_INET)
816 continue;
817 ia = ifatoia(ifa);
818 if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
819 t.s_addr) {
820 t = IA_SIN(ia)->sin_addr;
821 goto match;
822 }
823 }
824 }
825 /*
826 * If the packet was transiting through us, use the address of
827 * the interface the packet came through in. If that interface
828 * doesn't have a suitable IP address, the normal selection
829 * criteria apply.
830 */
831 if (V_icmp_rfi && ifp != NULL) {
832 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
833 if (ifa->ifa_addr->sa_family != AF_INET)
834 continue;
835 ia = ifatoia(ifa);
836 t = IA_SIN(ia)->sin_addr;
837 goto match;
838 }
839 }
840 /*
841 * If the incoming packet was not addressed directly to us, use
842 * designated interface for icmp replies specified by sysctl
843 * net.inet.icmp.reply_src (default not set). Otherwise continue
844 * with normal source selection.
845 */
846 if (V_reply_src[0] != '\0' && (ifp = ifunit(V_reply_src))) {
847 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
848 if (ifa->ifa_addr->sa_family != AF_INET)
849 continue;
850 ia = ifatoia(ifa);
851 t = IA_SIN(ia)->sin_addr;
852 goto match;
853 }
854 }
855 /*
856 * If the packet was transiting through us, use the address of
857 * the interface that is the closest to the packet source.
858 * When we don't have a route back to the packet source, stop here
859 * and drop the packet.
860 */
861 nh = fib4_lookup(M_GETFIB(m), ip->ip_dst, 0, NHR_NONE, 0);
862 if (nh == NULL) {
863 m_freem(m);
864 ICMPSTAT_INC(icps_noroute);
865 goto done;
866 }
867 t = IA_SIN(ifatoia(nh->nh_ifa))->sin_addr;
868 match:
869 #ifdef MAC
870 mac_netinet_icmp_replyinplace(m);
871 #endif
872 ip->ip_src = t;
873 /* ip->ip_tos will be reflected. */
874 ip->ip_off = htons(0);
875 ip->ip_ttl = V_ip_defttl;
876
877 if (optlen > 0) {
878 u_char *cp;
879 int opt, cnt;
880 u_int len;
881
882 /*
883 * Retrieve any source routing from the incoming packet;
884 * add on any record-route or timestamp options.
885 */
886 cp = (u_char *) (ip + 1);
887 if ((opts = ip_srcroute(m)) == NULL &&
888 (opts = m_gethdr(M_NOWAIT, MT_DATA))) {
889 opts->m_len = sizeof(struct in_addr);
890 mtod(opts, struct in_addr *)->s_addr = 0;
891 }
892 if (opts) {
893 #ifdef ICMPPRINTFS
894 if (icmpprintfs)
895 printf("icmp_reflect optlen %d rt %d => ",
896 optlen, opts->m_len);
897 #endif
898 for (cnt = optlen; cnt > 0; cnt -= len, cp += len) {
899 opt = cp[IPOPT_OPTVAL];
900 if (opt == IPOPT_EOL)
901 break;
902 if (opt == IPOPT_NOP)
903 len = 1;
904 else {
905 if (cnt < IPOPT_OLEN + sizeof(*cp))
906 break;
907 len = cp[IPOPT_OLEN];
908 if (len < IPOPT_OLEN + sizeof(*cp) ||
909 len > cnt)
910 break;
911 }
912 /*
913 * Should check for overflow, but it "can't happen"
914 */
915 if (opt == IPOPT_RR || opt == IPOPT_TS ||
916 opt == IPOPT_SECURITY) {
917 bcopy((caddr_t)cp,
918 mtod(opts, caddr_t) + opts->m_len, len);
919 opts->m_len += len;
920 }
921 }
922 /* Terminate & pad, if necessary */
923 cnt = opts->m_len % 4;
924 if (cnt) {
925 for (; cnt < 4; cnt++) {
926 *(mtod(opts, caddr_t) + opts->m_len) =
927 IPOPT_EOL;
928 opts->m_len++;
929 }
930 }
931 #ifdef ICMPPRINTFS
932 if (icmpprintfs)
933 printf("%d\n", opts->m_len);
934 #endif
935 }
936 ip_stripoptions(m);
937 }
938 m_tag_delete_nonpersistent(m);
939 m->m_flags &= ~(M_BCAST|M_MCAST);
940 icmp_send(m, opts);
941 done:
942 if (opts)
943 (void)m_free(opts);
944 }
945
946 /*
947 * Verifies if redirect message is valid, according to RFC 1122
948 *
949 * @src: sockaddr with address of redirect originator
950 * @dst: sockaddr with destination in question
951 * @gateway: new proposed gateway
952 *
953 * Returns 0 on success.
954 */
955 static int
icmp_verify_redirect_gateway(struct sockaddr_in * src,struct sockaddr_in * dst,struct sockaddr_in * gateway,u_int fibnum)956 icmp_verify_redirect_gateway(struct sockaddr_in *src, struct sockaddr_in *dst,
957 struct sockaddr_in *gateway, u_int fibnum)
958 {
959 struct nhop_object *nh;
960 struct ifaddr *ifa;
961
962 NET_EPOCH_ASSERT();
963
964 /* Verify the gateway is directly reachable. */
965 if ((ifa = ifa_ifwithnet((struct sockaddr *)gateway, 0, fibnum))==NULL)
966 return (ENETUNREACH);
967
968 /* TODO: fib-aware. */
969 if (ifa_ifwithaddr_check((struct sockaddr *)gateway))
970 return (EHOSTUNREACH);
971
972 nh = fib4_lookup(fibnum, dst->sin_addr, 0, NHR_NONE, 0);
973 if (nh == NULL)
974 return (EINVAL);
975
976 /*
977 * If the redirect isn't from our current router for this dst,
978 * it's either old or wrong. If it redirects us to ourselves,
979 * we have a routing loop, perhaps as a result of an interface
980 * going down recently.
981 */
982 if (!sa_equal((struct sockaddr *)src, &nh->gw_sa))
983 return (EINVAL);
984 if (nh->nh_ifa != ifa && ifa->ifa_addr->sa_family != AF_LINK)
985 return (EINVAL);
986
987 /* If host route already exists, ignore redirect. */
988 if (nh->nh_flags & NHF_HOST)
989 return (EEXIST);
990
991 /* If the prefix is directly reachable, ignore redirect. */
992 if (!(nh->nh_flags & NHF_GATEWAY))
993 return (EEXIST);
994
995 return (0);
996 }
997
998 /*
999 * Send an icmp packet back to the ip level,
1000 * after supplying a checksum.
1001 */
1002 static void
icmp_send(struct mbuf * m,struct mbuf * opts)1003 icmp_send(struct mbuf *m, struct mbuf *opts)
1004 {
1005 struct ip *ip = mtod(m, struct ip *);
1006 int hlen;
1007 struct icmp *icp;
1008
1009 hlen = ip->ip_hl << 2;
1010 m->m_data += hlen;
1011 m->m_len -= hlen;
1012 icp = mtod(m, struct icmp *);
1013 icp->icmp_cksum = 0;
1014 icp->icmp_cksum = in_cksum(m, ntohs(ip->ip_len) - hlen);
1015 m->m_data -= hlen;
1016 m->m_len += hlen;
1017 m->m_pkthdr.rcvif = (struct ifnet *)0;
1018 #ifdef ICMPPRINTFS
1019 if (icmpprintfs) {
1020 char dstbuf[INET_ADDRSTRLEN];
1021 char srcbuf[INET_ADDRSTRLEN];
1022
1023 printf("icmp_send dst %s src %s\n",
1024 inet_ntoa_r(ip->ip_dst, dstbuf),
1025 inet_ntoa_r(ip->ip_src, srcbuf));
1026 }
1027 #endif
1028 (void) ip_output(m, opts, NULL, 0, NULL, NULL);
1029 }
1030
1031 /*
1032 * Return milliseconds since 00:00 UTC in network format.
1033 */
1034 uint32_t
iptime(void)1035 iptime(void)
1036 {
1037 struct timeval atv;
1038 u_long t;
1039
1040 getmicrotime(&atv);
1041 t = (atv.tv_sec % (24*60*60)) * 1000 + atv.tv_usec / 1000;
1042 return (htonl(t));
1043 }
1044
1045 /*
1046 * Return the next larger or smaller MTU plateau (table from RFC 1191)
1047 * given current value MTU. If DIR is less than zero, a larger plateau
1048 * is returned; otherwise, a smaller value is returned.
1049 */
1050 int
ip_next_mtu(int mtu,int dir)1051 ip_next_mtu(int mtu, int dir)
1052 {
1053 static int mtutab[] = {
1054 65535, 32000, 17914, 8166, 4352, 2002, 1492, 1280, 1006, 508,
1055 296, 68, 0
1056 };
1057 int i, size;
1058
1059 size = (sizeof mtutab) / (sizeof mtutab[0]);
1060 if (dir >= 0) {
1061 for (i = 0; i < size; i++)
1062 if (mtu > mtutab[i])
1063 return mtutab[i];
1064 } else {
1065 for (i = size - 1; i >= 0; i--)
1066 if (mtu < mtutab[i])
1067 return mtutab[i];
1068 if (mtu == mtutab[0])
1069 return mtutab[0];
1070 }
1071 return 0;
1072 }
1073 #endif /* INET */
1074
1075 /*
1076 * badport_bandlim() - check for ICMP bandwidth limit
1077 *
1078 * Return 0 if it is ok to send an ICMP error response, -1 if we have
1079 * hit our bandwidth limit and it is not ok.
1080 *
1081 * If icmplim is <= 0, the feature is disabled and 0 is returned.
1082 *
1083 * For now we separate the TCP and UDP subsystems w/ different 'which'
1084 * values. We may eventually remove this separation (and simplify the
1085 * code further).
1086 *
1087 * Note that the printing of the error message is delayed so we can
1088 * properly print the icmp error rate that the system was trying to do
1089 * (i.e. 22000/100 pps, etc...). This can cause long delays in printing
1090 * the 'final' error, but it doesn't make sense to solve the printing
1091 * delay with more complex code.
1092 */
1093 VNET_DEFINE_STATIC(struct counter_rate *, icmp_rates[BANDLIM_MAX]);
1094 #define V_icmp_rates VNET(icmp_rates)
1095
1096 static const char *icmp_rate_descrs[BANDLIM_MAX] = {
1097 [BANDLIM_ICMP_UNREACH] = "icmp unreach",
1098 [BANDLIM_ICMP_ECHO] = "icmp ping",
1099 [BANDLIM_ICMP_TSTAMP] = "icmp tstamp",
1100 [BANDLIM_TCP_RST] = "tcp reset",
1101 [BANDLIM_ICMP6_UNREACH] = "icmp6 unreach",
1102 [BANDLIM_SCTP_OOTB] = "sctp ootb",
1103 };
1104
1105 static void
icmplim_new_jitter(int which)1106 icmplim_new_jitter(int which)
1107 {
1108 /*
1109 * Adjust limit +/- to jitter the measurement to deny a side-channel
1110 * port scan as in https://dl.acm.org/doi/10.1145/3372297.3417280
1111 */
1112 KASSERT(which >= 0 && which < BANDLIM_MAX,
1113 ("%s: which %d", __func__, which));
1114 if (V_icmplim_jitter > 0)
1115 V_icmplim_curr_jitter[which] =
1116 arc4random_uniform(V_icmplim_jitter * 2 + 1) -
1117 V_icmplim_jitter;
1118 }
1119
1120 static int
sysctl_icmplim_and_jitter(SYSCTL_HANDLER_ARGS)1121 sysctl_icmplim_and_jitter(SYSCTL_HANDLER_ARGS)
1122 {
1123 uint32_t new;
1124 int error;
1125 bool lim;
1126
1127 MPASS(oidp->oid_arg1 == &VNET_NAME(icmplim) ||
1128 oidp->oid_arg1 == &VNET_NAME(icmplim_jitter));
1129
1130 lim = (oidp->oid_arg1 == &VNET_NAME(icmplim));
1131 new = lim ? V_icmplim : V_icmplim_jitter;
1132 error = sysctl_handle_int(oidp, &new, 0, req);
1133 if (error == 0 && req->newptr) {
1134 if (lim) {
1135 if (new != 0 && new <= V_icmplim_jitter)
1136 error = EINVAL;
1137 else
1138 V_icmplim = new;
1139 } else {
1140 if (new >= V_icmplim)
1141 error = EINVAL;
1142 else {
1143 V_icmplim_jitter = new;
1144 for (int i = 0; i < BANDLIM_MAX; i++) {
1145 icmplim_new_jitter(i);
1146 }
1147 }
1148 }
1149 }
1150 MPASS(V_icmplim == 0 || V_icmplim > V_icmplim_jitter);
1151
1152 return (error);
1153 }
1154
1155 static void
icmp_bandlimit_init(void)1156 icmp_bandlimit_init(void)
1157 {
1158
1159 for (int i = 0; i < BANDLIM_MAX; i++) {
1160 V_icmp_rates[i] = counter_rate_alloc(M_WAITOK, 1);
1161 icmplim_new_jitter(i);
1162 }
1163 }
1164 VNET_SYSINIT(icmp_bandlimit, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY,
1165 icmp_bandlimit_init, NULL);
1166
1167 #ifdef VIMAGE
1168 static void
icmp_bandlimit_uninit(void)1169 icmp_bandlimit_uninit(void)
1170 {
1171
1172 for (int i = 0; i < BANDLIM_MAX; i++)
1173 counter_rate_free(V_icmp_rates[i]);
1174 }
1175 VNET_SYSUNINIT(icmp_bandlimit, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD,
1176 icmp_bandlimit_uninit, NULL);
1177 #endif
1178
1179 int
badport_bandlim(int which)1180 badport_bandlim(int which)
1181 {
1182 int64_t pps;
1183
1184 if (V_icmplim == 0)
1185 return (0);
1186
1187 KASSERT(which >= 0 && which < BANDLIM_MAX,
1188 ("%s: which %d", __func__, which));
1189
1190 pps = counter_ratecheck(V_icmp_rates[which], V_icmplim +
1191 V_icmplim_curr_jitter[which]);
1192 if (pps > 0) {
1193 if (V_icmplim_output)
1194 log(LOG_NOTICE,
1195 "Limiting %s response from %jd to %d packets/sec\n",
1196 icmp_rate_descrs[which], (intmax_t )pps,
1197 V_icmplim + V_icmplim_curr_jitter[which]);
1198 icmplim_new_jitter(which);
1199 }
1200 if (pps == -1)
1201 return (-1);
1202 return (0);
1203 }
1204