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*/
1 /*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * Internet Control Message Protocol (ICMP)
7 *
8 * Version: @(#)icmp.c 1.0.11 06/02/93
9 *
10 * Authors: Ross Biro, <bir7@leland.Stanford.Edu>
11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12 * Mark Evans, <evansmp@uhura.aston.ac.uk>
13 * Alan Cox, <gw4pts@gw4pts.ampr.org>
14 * Stefan Becker, <stefanb@yello.ping.de>
15 *
16 * Fixes:
17 * Alan Cox : Generic queue usage.
18 * Gerhard Koerting: ICMP addressing corrected
19 * Alan Cox : Use tos/ttl settings
20 * Alan Cox : Protocol violations
21 * Alan Cox : SNMP Statistics
22 * Alan Cox : Routing errors
23 * Alan Cox : Changes for newer routing code
24 * Alan Cox : Removed old debugging junk
25 * Alan Cox : Fixed the ICMP error status of net/host unreachable
26 * Gerhard Koerting : Fixed broadcast ping properly
27 * Ulrich Kunitz : Fixed ICMP timestamp reply
28 * A.N.Kuznetsov : Multihoming fixes.
29 * Laco Rusnak : Multihoming fixes.
30 * Alan Cox : Tightened up icmp_send().
31 * Alan Cox : Multicasts.
32 * Stefan Becker : ICMP redirects in icmp_send().
33 *
34 *
35 *
36 * This program is free software; you can redistribute it and/or
37 * modify it under the terms of the GNU General Public License
38 * as published by the Free Software Foundation; either version
39 * 2 of the License, or (at your option) any later version.
40 */
41 #include <linux/types.h>
42 #include <linux/sched.h>
43 #include <linux/kernel.h>
44 #include <linux/fcntl.h>
45 #include <linux/socket.h>
46 #include <linux/in.h>
47 #include <linux/inet.h>
48 #include <linux/netdevice.h>
49 #include <linux/string.h>
50 #include "snmp.h"
51 #include "ip.h"
52 #include "route.h"
53 #include "protocol.h"
54 #include "icmp.h"
55 #include "tcp.h"
56 #include "snmp.h"
57 #include <linux/skbuff.h>
58 #include "sock.h"
59 #include <linux/errno.h>
60 #include <linux/timer.h>
61 #include <asm/system.h>
62 #include <asm/segment.h>
63
64
65 #define min(a,b) ((a)<(b)?(a):(b))
66
67
68 /*
69 * Statistics
70 */
71
72 struct icmp_mib icmp_statistics={0,};
73
74
75 /* An array of errno for error messages from dest unreach. */
76 struct icmp_err icmp_err_convert[] = {
77 { ENETUNREACH, 0 }, /* ICMP_NET_UNREACH */
78 { EHOSTUNREACH, 0 }, /* ICMP_HOST_UNREACH */
79 { ENOPROTOOPT, 1 }, /* ICMP_PROT_UNREACH */
80 { ECONNREFUSED, 1 }, /* ICMP_PORT_UNREACH */
81 { EOPNOTSUPP, 0 }, /* ICMP_FRAG_NEEDED */
82 { EOPNOTSUPP, 0 }, /* ICMP_SR_FAILED */
83 { ENETUNREACH, 1 }, /* ICMP_NET_UNKNOWN */
84 { EHOSTDOWN, 1 }, /* ICMP_HOST_UNKNOWN */
85 { ENONET, 1 }, /* ICMP_HOST_ISOLATED */
86 { ENETUNREACH, 1 }, /* ICMP_NET_ANO */
87 { EHOSTUNREACH, 1 }, /* ICMP_HOST_ANO */
88 { EOPNOTSUPP, 0 }, /* ICMP_NET_UNR_TOS */
89 { EOPNOTSUPP, 0 } /* ICMP_HOST_UNR_TOS */
90 };
91
92
93 /*
94 * Send an ICMP message in response to a situation
95 *
96 * Fixme: Fragment handling is wrong really.
97 */
98
99 void icmp_send(struct sk_buff *skb_in, int type, int code, unsigned long info, struct device *dev)
/* ![[next]](../icons/right.png)
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*/
100 {
101 struct sk_buff *skb;
102 struct iphdr *iph;
103 int offset;
104 struct icmphdr *icmph;
105 int len;
106 struct device *ndev=NULL; /* Make this =dev to force replies on the same interface */
107 unsigned long our_addr;
108 int atype;
109
110 /*
111 * Find the original IP header.
112 */
113
114 iph = (struct iphdr *) (skb_in->data + dev->hard_header_len);
115
116 /*
117 * No replies to MAC multicast
118 */
119
120 if(skb_in->pkt_type!=PACKET_HOST)
121 return;
122
123 /*
124 * No replies to IP multicasting
125 */
126
127 atype=ip_chk_addr(iph->daddr);
128 if(atype==IS_BROADCAST || IN_MULTICAST(iph->daddr))
129 return;
130
131 /*
132 * Only reply to first fragment.
133 */
134
135 if(ntohs(iph->frag_off)&IP_OFFSET)
136 return;
137
138 /*
139 * We must NEVER NEVER send an ICMP error to an ICMP error message
140 */
141
142 if(type==ICMP_DEST_UNREACH||type==ICMP_REDIRECT||type==ICMP_SOURCE_QUENCH||type==ICMP_TIME_EXCEEDED)
143 {
144
145 /*
146 * Is the original packet an ICMP packet?
147 */
148
149 if(iph->protocol==IPPROTO_ICMP)
150 {
151 icmph = (struct icmphdr *) ((char *) iph +
152 4 * iph->ihl);
153 /*
154 * Check for ICMP error packets (Must never reply to
155 * an ICMP error).
156 */
157
158 if (icmph->type == ICMP_DEST_UNREACH ||
159 icmph->type == ICMP_SOURCE_QUENCH ||
160 icmph->type == ICMP_REDIRECT ||
161 icmph->type == ICMP_TIME_EXCEEDED ||
162 icmph->type == ICMP_PARAMETERPROB)
163 return;
164 }
165 }
166 icmp_statistics.IcmpOutMsgs++;
167
168 /*
169 * This needs a tidy.
170 */
171
172 switch(type)
173 {
174 case ICMP_DEST_UNREACH:
175 icmp_statistics.IcmpOutDestUnreachs++;
176 break;
177 case ICMP_SOURCE_QUENCH:
178 icmp_statistics.IcmpOutSrcQuenchs++;
179 break;
180 case ICMP_REDIRECT:
181 icmp_statistics.IcmpOutRedirects++;
182 break;
183 case ICMP_ECHO:
184 icmp_statistics.IcmpOutEchos++;
185 break;
186 case ICMP_ECHOREPLY:
187 icmp_statistics.IcmpOutEchoReps++;
188 break;
189 case ICMP_TIME_EXCEEDED:
190 icmp_statistics.IcmpOutTimeExcds++;
191 break;
192 case ICMP_PARAMETERPROB:
193 icmp_statistics.IcmpOutParmProbs++;
194 break;
195 case ICMP_TIMESTAMP:
196 icmp_statistics.IcmpOutTimestamps++;
197 break;
198 case ICMP_TIMESTAMPREPLY:
199 icmp_statistics.IcmpOutTimestampReps++;
200 break;
201 case ICMP_ADDRESS:
202 icmp_statistics.IcmpOutAddrMasks++;
203 break;
204 case ICMP_ADDRESSREPLY:
205 icmp_statistics.IcmpOutAddrMaskReps++;
206 break;
207 }
208 /*
209 * Get some memory for the reply.
210 */
211
212 len = dev->hard_header_len + sizeof(struct iphdr) + sizeof(struct icmphdr) +
213 sizeof(struct iphdr) + 8; /* amount of header to return */
214
215 skb = (struct sk_buff *) alloc_skb(len, GFP_ATOMIC);
216 if (skb == NULL)
217 {
218 icmp_statistics.IcmpOutErrors++;
219 return;
220 }
221 skb->free = 1;
222
223 /*
224 * Build Layer 2-3 headers for message back to source.
225 */
226
227 our_addr = dev->pa_addr;
228 if (iph->daddr != our_addr && ip_chk_addr(iph->daddr) == IS_MYADDR)
229 our_addr = iph->daddr;
230 offset = ip_build_header(skb, our_addr, iph->saddr,
231 &ndev, IPPROTO_ICMP, NULL, len,
232 skb_in->ip_hdr->tos,255);
233 if (offset < 0)
234 {
235 icmp_statistics.IcmpOutErrors++;
236 skb->sk = NULL;
237 kfree_skb(skb, FREE_READ);
238 return;
239 }
240
241 /*
242 * Re-adjust length according to actual IP header size.
243 */
244
245 skb->len = offset + sizeof(struct icmphdr) + sizeof(struct iphdr) + 8;
246
247 /*
248 * Fill in the frame
249 */
250
251 icmph = (struct icmphdr *) (skb->data + offset);
252 icmph->type = type;
253 icmph->code = code;
254 icmph->checksum = 0;
255 icmph->un.gateway = info; /* This might not be meant for
256 this form of the union but it will
257 be right anyway */
258 memcpy(icmph + 1, iph, sizeof(struct iphdr) + 8);
259
260 icmph->checksum = ip_compute_csum((unsigned char *)icmph,
261 sizeof(struct icmphdr) + sizeof(struct iphdr) + 8);
262
263 /*
264 * Send it and free it once sent.
265 */
266 ip_queue_xmit(NULL, ndev, skb, 1);
267 }
268
269
270 /*
271 * Handle ICMP_UNREACH and ICMP_QUENCH.
272 */
273
274 static void icmp_unreach(struct icmphdr *icmph, struct sk_buff *skb)
/* ![[previous]](../icons/left.png)
*/
275 {
276 struct inet_protocol *ipprot;
277 struct iphdr *iph;
278 unsigned char hash;
279 int err;
280
281 err = (icmph->type << 8) | icmph->code;
282 iph = (struct iphdr *) (icmph + 1);
283
284 switch(icmph->code & 7)
285 {
286 case ICMP_NET_UNREACH:
287 break;
288 case ICMP_HOST_UNREACH:
289 break;
290 case ICMP_PROT_UNREACH:
291 printk("ICMP: %s:%d: protocol unreachable.\n",
292 in_ntoa(iph->daddr), ntohs(iph->protocol));
293 break;
294 case ICMP_PORT_UNREACH:
295 break;
296 case ICMP_FRAG_NEEDED:
297 printk("ICMP: %s: fragmentation needed and DF set.\n",
298 in_ntoa(iph->daddr));
299 break;
300 case ICMP_SR_FAILED:
301 printk("ICMP: %s: Source Route Failed.\n", in_ntoa(iph->daddr));
302 break;
303 default:
304 break;
305 }
306
307 /*
308 * Get the protocol(s).
309 */
310
311 hash = iph->protocol & (MAX_INET_PROTOS -1);
312
313 /*
314 * This can't change while we are doing it.
315 */
316
317 ipprot = (struct inet_protocol *) inet_protos[hash];
318 while(ipprot != NULL)
319 {
320 struct inet_protocol *nextip;
321
322 nextip = (struct inet_protocol *) ipprot->next;
323
324 /*
325 * Pass it off to everyone who wants it.
326 */
327 if (iph->protocol == ipprot->protocol && ipprot->err_handler)
328 {
329 ipprot->err_handler(err, (unsigned char *)(icmph + 1),
330 iph->daddr, iph->saddr, ipprot);
331 }
332
333 ipprot = nextip;
334 }
335 kfree_skb(skb, FREE_READ);
336 }
337
338
339 /*
340 * Handle ICMP_REDIRECT.
341 */
342
343 static void icmp_redirect(struct icmphdr *icmph, struct sk_buff *skb,
/* */
344 struct device *dev, unsigned long source)
345 {
346 struct rtable *rt;
347 struct iphdr *iph;
348 unsigned long ip;
349
350 /*
351 * Get the copied header of the packet that caused the redirect
352 */
353
354 iph = (struct iphdr *) (icmph + 1);
355 ip = iph->daddr;
356
357 switch(icmph->code & 7)
358 {
359 case ICMP_REDIR_NET:
360 /*
361 * This causes a problem with subnetted networks. What we should do
362 * is use ICMP_ADDRESS to get the subnet mask of the problem route
363 * and set both. But we don't..
364 */
365 #ifdef not_a_good_idea
366 ip_rt_add((RTF_DYNAMIC | RTF_MODIFIED | RTF_GATEWAY),
367 ip, 0, icmph->un.gateway, dev,0, 0);
368 break;
369 #endif
370 case ICMP_REDIR_HOST:
371 /*
372 * Add better route to host.
373 * But first check that the redirect
374 * comes from the old gateway..
375 * And make sure it's an ok host address
376 * (not some confused thing sending our
377 * address)
378 */
379 rt = ip_rt_route(ip, NULL, NULL);
380 if (!rt)
381 break;
382 if (rt->rt_gateway != source || ip_chk_addr(icmph->un.gateway))
383 break;
384 printk("redirect from %s\n", in_ntoa(source));
385 ip_rt_add((RTF_DYNAMIC | RTF_MODIFIED | RTF_HOST | RTF_GATEWAY),
386 ip, 0, icmph->un.gateway, dev,0, 0);
387 break;
388 case ICMP_REDIR_NETTOS:
389 case ICMP_REDIR_HOSTTOS:
390 printk("ICMP: cannot handle TOS redirects yet!\n");
391 break;
392 default:
393 break;
394 }
395
396 /*
397 * Discard the original packet
398 */
399
400 kfree_skb(skb, FREE_READ);
401 }
402
403
404 /*
405 * Handle ICMP_ECHO ("ping") requests.
406 */
407
408 static void icmp_echo(struct icmphdr *icmph, struct sk_buff *skb, struct device *dev,
/* */
409 unsigned long saddr, unsigned long daddr, int len,
410 struct options *opt)
411 {
412 struct icmphdr *icmphr;
413 struct sk_buff *skb2;
414 struct device *ndev=NULL;
415 int size, offset;
416
417 icmp_statistics.IcmpOutEchoReps++;
418 icmp_statistics.IcmpOutMsgs++;
419
420 size = dev->hard_header_len + 64 + len;
421 skb2 = alloc_skb(size, GFP_ATOMIC);
422
423 if (skb2 == NULL)
424 {
425 icmp_statistics.IcmpOutErrors++;
426 kfree_skb(skb, FREE_READ);
427 return;
428 }
429 skb2->free = 1;
430
431 /* Build Layer 2-3 headers for message back to source */
432 offset = ip_build_header(skb2, daddr, saddr, &ndev,
433 IPPROTO_ICMP, opt, len, skb->ip_hdr->tos,255);
434 if (offset < 0)
435 {
436 icmp_statistics.IcmpOutErrors++;
437 printk("ICMP: Could not build IP Header for ICMP ECHO Response\n");
438 kfree_skb(skb2,FREE_WRITE);
439 kfree_skb(skb, FREE_READ);
440 return;
441 }
442
443 /*
444 * Re-adjust length according to actual IP header size.
445 */
446
447 skb2->len = offset + len;
448
449 /*
450 * Build ICMP_ECHO Response message.
451 */
452 icmphr = (struct icmphdr *) (skb2->data + offset);
453 memcpy((char *) icmphr, (char *) icmph, len);
454 icmphr->type = ICMP_ECHOREPLY;
455 icmphr->code = 0;
456 icmphr->checksum = 0;
457 icmphr->checksum = ip_compute_csum((unsigned char *)icmphr, len);
458
459 /*
460 * Ship it out - free it when done
461 */
462 ip_queue_xmit((struct sock *)NULL, ndev, skb2, 1);
463
464 /*
465 * Free the received frame
466 */
467
468 kfree_skb(skb, FREE_READ);
469 }
470
471 /*
472 * Handle ICMP Timestamp requests.
473 */
474
475 static void icmp_timestamp(struct icmphdr *icmph, struct sk_buff *skb, struct device *dev,
/* */
476 unsigned long saddr, unsigned long daddr, int len,
477 struct options *opt)
478 {
479 struct icmphdr *icmphr;
480 struct sk_buff *skb2;
481 int size, offset;
482 unsigned long *timeptr, midtime;
483 struct device *ndev=NULL;
484
485 if (len != 20)
486 {
487 printk(
488 "ICMP: Size (%d) of ICMP_TIMESTAMP request should be 20!\n",
489 len);
490 icmp_statistics.IcmpInErrors++;
491 #if 1
492 /* correct answers are possible for everything >= 12 */
493 if (len < 12)
494 #endif
495 return;
496 }
497
498 size = dev->hard_header_len + 84;
499
500 if (! (skb2 = alloc_skb(size, GFP_ATOMIC)))
501 {
502 skb->sk = NULL;
503 kfree_skb(skb, FREE_READ);
504 icmp_statistics.IcmpOutErrors++;
505 return;
506 }
507 skb2->free = 1;
508
509 /*
510 * Build Layer 2-3 headers for message back to source
511 */
512
513 offset = ip_build_header(skb2, daddr, saddr, &ndev, IPPROTO_ICMP, opt, len,
514 skb->ip_hdr->tos, 255);
515 if (offset < 0)
516 {
517 printk("ICMP: Could not build IP Header for ICMP TIMESTAMP Response\n");
518 kfree_skb(skb2, FREE_WRITE);
519 kfree_skb(skb, FREE_READ);
520 icmp_statistics.IcmpOutErrors++;
521 return;
522 }
523
524 /*
525 * Re-adjust length according to actual IP header size.
526 */
527 skb2->len = offset + 20;
528
529 /*
530 * Build ICMP_TIMESTAMP Response message.
531 */
532
533 icmphr = (struct icmphdr *) ((char *) (skb2 + 1) + offset);
534 memcpy((char *) icmphr, (char *) icmph, 12);
535 icmphr->type = ICMP_TIMESTAMPREPLY;
536 icmphr->code = icmphr->checksum = 0;
537
538 /* fill in the current time as ms since midnight UT: */
539 midtime = (xtime.tv_sec % 86400) * 1000 + xtime.tv_usec / 1000;
540 timeptr = (unsigned long *) (icmphr + 1);
541 /*
542 * the originate timestamp (timeptr [0]) is still in the copy:
543 */
544 timeptr [1] = timeptr [2] = htonl(midtime);
545
546 icmphr->checksum = ip_compute_csum((unsigned char *) icmphr, 20);
547
548 /*
549 * Ship it out - free it when done
550 */
551
552 ip_queue_xmit((struct sock *) NULL, ndev, skb2, 1);
553 icmp_statistics.IcmpOutTimestampReps++;
554 kfree_skb(skb, FREE_READ);
555 }
556
557
558
559
560 /*
561 * Handle the ICMP INFORMATION REQUEST.
562 */
563
564 static void icmp_info(struct icmphdr *icmph, struct sk_buff *skb, struct device *dev,
/* */
565 unsigned long saddr, unsigned long daddr, int len,
566 struct options *opt)
567 {
568 /* Obsolete */
569 kfree_skb(skb, FREE_READ);
570 }
571
572
573 /*
574 * Handle ICMP_ADDRESS_MASK requests.
575 */
576
577 static void icmp_address(struct icmphdr *icmph, struct sk_buff *skb, struct device *dev,
/* */
578 unsigned long saddr, unsigned long daddr, int len,
579 struct options *opt)
580 {
581 struct icmphdr *icmphr;
582 struct sk_buff *skb2;
583 int size, offset;
584 struct device *ndev=NULL;
585
586 icmp_statistics.IcmpOutMsgs++;
587 icmp_statistics.IcmpOutAddrMaskReps++;
588
589 size = dev->hard_header_len + 64 + len;
590 skb2 = alloc_skb(size, GFP_ATOMIC);
591 if (skb2 == NULL)
592 {
593 icmp_statistics.IcmpOutErrors++;
594 kfree_skb(skb, FREE_READ);
595 return;
596 }
597 skb2->free = 1;
598
599 /*
600 * Build Layer 2-3 headers for message back to source
601 */
602
603 offset = ip_build_header(skb2, daddr, saddr, &ndev,
604 IPPROTO_ICMP, opt, len, skb->ip_hdr->tos,255);
605 if (offset < 0)
606 {
607 icmp_statistics.IcmpOutErrors++;
608 printk("ICMP: Could not build IP Header for ICMP ADDRESS Response\n");
609 kfree_skb(skb2,FREE_WRITE);
610 kfree_skb(skb, FREE_READ);
611 return;
612 }
613
614 /*
615 * Re-adjust length according to actual IP header size.
616 */
617
618 skb2->len = offset + len;
619
620 /*
621 * Build ICMP ADDRESS MASK Response message.
622 */
623
624 icmphr = (struct icmphdr *) (skb2->data + offset);
625 icmphr->type = ICMP_ADDRESSREPLY;
626 icmphr->code = 0;
627 icmphr->checksum = 0;
628 icmphr->un.echo.id = icmph->un.echo.id;
629 icmphr->un.echo.sequence = icmph->un.echo.sequence;
630 memcpy((char *) (icmphr + 1), (char *) &dev->pa_mask, sizeof(dev->pa_mask));
631
632 icmphr->checksum = ip_compute_csum((unsigned char *)icmphr, len);
633
634 /* Ship it out - free it when done */
635 ip_queue_xmit((struct sock *)NULL, ndev, skb2, 1);
636
637 skb->sk = NULL;
638 kfree_skb(skb, FREE_READ);
639 }
640
641
642 /*
643 * Deal with incoming ICMP packets.
644 */
645
646 int icmp_rcv(struct sk_buff *skb1, struct device *dev, struct options *opt,
/* */
647 unsigned long daddr, unsigned short len,
648 unsigned long saddr, int redo, struct inet_protocol *protocol)
649 {
650 struct icmphdr *icmph;
651 unsigned char *buff;
652
653 /*
654 * Drop broadcast packets. IP has done a broadcast check and ought one day
655 * to pass on that information.
656 */
657
658 icmp_statistics.IcmpInMsgs++;
659
660
661 /*
662 * Grab the packet as an icmp object
663 */
664
665 buff = skb1->h.raw;
666 icmph = (struct icmphdr *) buff;
667
668 /*
669 * Validate the packet first
670 */
671
672 if (ip_compute_csum((unsigned char *) icmph, len))
673 {
674 /* Failed checksum! */
675 icmp_statistics.IcmpInErrors++;
676 printk("ICMP: failed checksum from %s!\n", in_ntoa(saddr));
677 kfree_skb(skb1, FREE_READ);
678 return(0);
679 }
680
681 /*
682 * Parse the ICMP message
683 */
684
685 if (ip_chk_addr(daddr) != IS_MYADDR)
686 {
687 if (icmph->type != ICMP_ECHO)
688 {
689 icmp_statistics.IcmpInErrors++;
690 kfree_skb(skb1, FREE_READ);
691 return(0);
692 }
693 daddr=dev->pa_addr;
694 }
695
696 switch(icmph->type)
697 {
698 case ICMP_TIME_EXCEEDED:
699 icmp_statistics.IcmpInTimeExcds++;
700 icmp_unreach(icmph, skb1);
701 return 0;
702 case ICMP_DEST_UNREACH:
703 icmp_statistics.IcmpInDestUnreachs++;
704 icmp_unreach(icmph, skb1);
705 return 0;
706 case ICMP_SOURCE_QUENCH:
707 icmp_statistics.IcmpInSrcQuenchs++;
708 icmp_unreach(icmph, skb1);
709 return(0);
710 case ICMP_REDIRECT:
711 icmp_statistics.IcmpInRedirects++;
712 icmp_redirect(icmph, skb1, dev, saddr);
713 return(0);
714 case ICMP_ECHO:
715 icmp_statistics.IcmpInEchos++;
716 icmp_echo(icmph, skb1, dev, saddr, daddr, len, opt);
717 return 0;
718 case ICMP_ECHOREPLY:
719 icmp_statistics.IcmpInEchoReps++;
720 kfree_skb(skb1, FREE_READ);
721 return(0);
722 case ICMP_TIMESTAMP:
723 icmp_statistics.IcmpInTimestamps++;
724 icmp_timestamp(icmph, skb1, dev, saddr, daddr, len, opt);
725 return 0;
726 case ICMP_TIMESTAMPREPLY:
727 icmp_statistics.IcmpInTimestampReps++;
728 kfree_skb(skb1,FREE_READ);
729 return 0;
730 /* INFO is obsolete and doesn't even feature in the SNMP stats */
731 case ICMP_INFO_REQUEST:
732 icmp_info(icmph, skb1, dev, saddr, daddr, len, opt);
733 return 0;
734 case ICMP_INFO_REPLY:
735 skb1->sk = NULL;
736 kfree_skb(skb1, FREE_READ);
737 return(0);
738 case ICMP_ADDRESS:
739 icmp_statistics.IcmpInAddrMasks++;
740 icmp_address(icmph, skb1, dev, saddr, daddr, len, opt);
741 return 0;
742 case ICMP_ADDRESSREPLY:
743 /*
744 * We ought to set our netmask on receiving this, but
745 * experience shows it's a waste of effort.
746 */
747 icmp_statistics.IcmpInAddrMaskReps++;
748 kfree_skb(skb1, FREE_READ);
749 return(0);
750 default:
751 icmp_statistics.IcmpInErrors++;
752 kfree_skb(skb1, FREE_READ);
753 return(0);
754 }
755 /*NOTREACHED*/
756 kfree_skb(skb1, FREE_READ);
757 return(-1);
758 }
759
760
761 /*
762 * Perform any ICMP-related I/O control requests.
763 * [to vanish soon]
764 */
765
766 int icmp_ioctl(struct sock *sk, int cmd, unsigned long arg)
/* ![[last]](../icons/n_last.png)
*/
767 {
768 switch(cmd)
769 {
770 default:
771 return(-EINVAL);
772 }
773 return(0);
774 }
![[bottom]](../icons/n_bottom.png){kind=icon}
*/