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*/
1 /*
2 * NET3: Implementation of the ICMP protocol layer.
3 *
4 * Alan Cox, <alan@cymru.net>
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 *
11 * Some of the function names and the icmp unreach table for this
12 * module were derived from [icmp.c 1.0.11 06/02/93] by
13 * Ross Biro, Fred N. van Kempen, Mark Evans, Alan Cox, Gerhard Koerting.
14 * Other than that this module is a complete rewrite.
15 *
16 * Fixes:
17 * Mike Shaver : RFC1122 checks.
18 * Alan Cox : Multicast ping reply as self.
19 *
20 *
21 *
22 * RFC1122 Status: (boy, are there a lot of rules for ICMP)
23 * 3.2.2 (Generic ICMP stuff)
24 * MUST discard messages of unknown type. (OK)
25 * MUST copy at least the first 8 bytes from the offending packet
26 * when sending ICMP errors. (OK)
27 * MUST pass received ICMP errors up to protocol level. (OK)
28 * SHOULD send ICMP errors with TOS == 0. (OK)
29 * MUST NOT send ICMP errors in reply to:
30 * ICMP errors (OK)
31 * Broadcast/multicast datagrams (OK)
32 * MAC broadcasts (OK)
33 * Non-initial fragments (OK)
34 * Datagram with a source address that isn't a single host. (OK)
35 * 3.2.2.1 (Destination Unreachable)
36 * All the rules govern the IP layer, and are dealt with in ip.c, not here.
37 * 3.2.2.2 (Redirect)
38 * Host SHOULD NOT send ICMP_REDIRECTs. (OK)
39 * MUST update routing table in response to host or network redirects.
40 * (host OK, network NOT YET) [Intentionally -- AC]
41 * SHOULD drop redirects if they're not from directly connected gateway
42 * (OK -- we drop it if it's not from our old gateway, which is close
43 * enough)
44 * 3.2.2.3 (Source Quench)
45 * MUST pass incoming SOURCE_QUENCHs to transport layer (OK)
46 * Other requirements are dealt with at the transport layer.
47 * 3.2.2.4 (Time Exceeded)
48 * MUST pass TIME_EXCEEDED to transport layer (OK)
49 * Other requirements dealt with at IP (generating TIME_EXCEEDED).
50 * 3.2.2.5 (Parameter Problem)
51 * SHOULD generate these, but it doesn't say for what. So we're OK. =)
52 * MUST pass received PARAMPROBLEM to transport layer (NOT YET)
53 * [Solaris 2.X seems to assert EPROTO when this occurs] -- AC
54 * 3.2.2.6 (Echo Request/Reply)
55 * MUST reply to ECHO_REQUEST, and give app to do ECHO stuff (OK, OK)
56 * MAY discard broadcast ECHO_REQUESTs. (We don't, but that's OK.)
57 * MUST reply using same source address as the request was sent to.
58 * We're OK for unicast ECHOs, and it doesn't say anything about
59 * how to handle broadcast ones, since it's optional.
60 * MUST copy data from REQUEST to REPLY (OK)
61 * unless it would require illegal fragmentation (N/A)
62 * MUST pass REPLYs to transport/user layer (OK)
63 * MUST use any provided source route (reversed) for REPLY. (NOT YET)
64 * 3.2.2.7 (Information Request/Reply)
65 * MUST NOT implement this. (I guess that means silently discard...?) (OK)
66 * 3.2.2.8 (Timestamp Request/Reply)
67 * MAY implement (OK)
68 * SHOULD be in-kernel for "minimum variability" (OK)
69 * MAY discard broadcast REQUESTs. (OK, but see source for inconsistency)
70 * MUST reply using same source address as the request was sent to. (OK)
71 * MUST reverse source route, as per ECHO (NOT YET)
72 * MUST pass REPLYs to transport/user layer (requires RAW, just like ECHO) (OK)
73 * MUST update clock for timestamp at least 15 times/sec (OK)
74 * MUST be "correct within a few minutes" (OK)
75 * 3.2.2.9 (Address Mask Request/Reply)
76 * MAY implement (OK)
77 * MUST send a broadcast REQUEST if using this system to set netmask
78 * (OK... we don't use it)
79 * MUST discard received REPLYs if not using this system (OK)
80 * MUST NOT send replies unless specifically made agent for this sort
81 * of thing. (OK)
82 */
83
84 #include <linux/config.h>
85 #include <linux/types.h>
86 #include <linux/sched.h>
87 #include <linux/kernel.h>
88 #include <linux/fcntl.h>
89 #include <linux/socket.h>
90 #include <linux/in.h>
91 #include <linux/inet.h>
92 #include <linux/netdevice.h>
93 #include <linux/string.h>
94 #include <net/snmp.h>
95 #include <net/ip.h>
96 #include <net/route.h>
97 #include <net/protocol.h>
98 #include <net/icmp.h>
99 #include <net/tcp.h>
100 #include <net/snmp.h>
101 #include <linux/skbuff.h>
102 #include <net/sock.h>
103 #include <linux/errno.h>
104 #include <linux/timer.h>
105 #include <asm/system.h>
106 #include <asm/segment.h>
107 #include <net/checksum.h>
108
109 #define min(a,b) ((a)<(b)?(a):(b))
110
111 /*
112 * Statistics
113 */
114
115 struct icmp_mib icmp_statistics;
116
117 /* An array of errno for error messages from dest unreach. */
118 /* RFC 1122: 3.2.2.1 States that NET_UNREACH, HOS_UNREACH and SR_FAIELD MUST be considered 'transient errrs'. */
119
120 struct icmp_err icmp_err_convert[] = {
121 { ENETUNREACH, 0 }, /* ICMP_NET_UNREACH */
122 { EHOSTUNREACH, 0 }, /* ICMP_HOST_UNREACH */
123 { ENOPROTOOPT, 1 }, /* ICMP_PROT_UNREACH */
124 { ECONNREFUSED, 1 }, /* ICMP_PORT_UNREACH */
125 { EOPNOTSUPP, 0 }, /* ICMP_FRAG_NEEDED */
126 { EOPNOTSUPP, 0 }, /* ICMP_SR_FAILED */
127 { ENETUNREACH, 1 }, /* ICMP_NET_UNKNOWN */
128 { EHOSTDOWN, 1 }, /* ICMP_HOST_UNKNOWN */
129 { ENONET, 1 }, /* ICMP_HOST_ISOLATED */
130 { ENETUNREACH, 1 }, /* ICMP_NET_ANO */
131 { EHOSTUNREACH, 1 }, /* ICMP_HOST_ANO */
132 { EOPNOTSUPP, 0 }, /* ICMP_NET_UNR_TOS */
133 { EOPNOTSUPP, 0 } /* ICMP_HOST_UNR_TOS */
134 };
135
136 /*
137 * A spare long used to speed up statistics udpating
138 */
139
140 unsigned long dummy;
141
142 /*
143 * ICMP control array. This specifies what to do with each ICMP.
144 */
145
146 struct icmp_control
147 {
148 unsigned long *output; /* Address to increment on output */
149 unsigned long *input; /* Address to increment on input */
150 void (*handler)(struct icmphdr *icmph, struct sk_buff *skb, struct device *dev, __u32 saddr, __u32 daddr, int len);
151 unsigned long error; /* This ICMP is classed as an error message */
152 };
153
154 static struct icmp_control icmp_pointers[19];
155
156 /*
157 * Build xmit assembly blocks
158 */
159
160 struct icmp_bxm
161 {
162 void *data_ptr;
163 int data_len;
164 struct icmphdr icmph;
165 unsigned long csum;
166 struct options replyopts;
167 unsigned char optbuf[40];
168 };
169
170 /*
171 * The ICMP socket. This is the most convenient way to flow control
172 * our ICMP output as well as maintain a clean interface throughout
173 * all layers. All Socketless IP sends will soon be gone.
174 */
175
176 struct socket icmp_socket;
177
178 /*
179 * Send an ICMP frame.
180 */
181
182
183 /*
184 * Maintain the counters used in the SNMP statistics for outgoing ICMP
185 */
186
187 static void icmp_out_count(int type)
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*/
188 {
189 if(type>18)
190 return;
191 (*icmp_pointers[type].output)++;
192 icmp_statistics.IcmpOutMsgs++;
193 }
194
195 /*
196 * Checksum each fragment, and on the first include the headers and final checksum.
197 */
198
199 static void icmp_glue_bits(const void *p, __u32 saddr, char *to, unsigned int offset, unsigned int fraglen)
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*/
200 {
201 struct icmp_bxm *icmp_param = (struct icmp_bxm *)p;
202 struct icmphdr *icmph;
203 unsigned long csum;
204
205 if (offset) {
206 icmp_param->csum=csum_partial_copy(icmp_param->data_ptr+offset-sizeof(struct icmphdr),
207 to, fraglen,icmp_param->csum);
208 return;
209 }
210
211 /*
212 * First fragment includes header. Note that we've done
213 * the other fragments first, so that we get the checksum
214 * for the whole packet here.
215 */
216 csum = csum_partial_copy((void *)&icmp_param->icmph,
217 to, sizeof(struct icmphdr),
218 icmp_param->csum);
219 csum = csum_partial_copy(icmp_param->data_ptr,
220 to+sizeof(struct icmphdr),
221 fraglen-sizeof(struct icmphdr), csum);
222 icmph=(struct icmphdr *)to;
223 icmph->checksum = csum_fold(csum);
224 }
225
226 /*
227 * Driving logic for building and sending ICMP messages.
228 */
229
230 static void icmp_build_xmit(struct icmp_bxm *icmp_param, __u32 saddr, __u32 daddr)
/* */
231 {
232 struct sock *sk=icmp_socket.data;
233 icmp_param->icmph.checksum=0;
234 icmp_param->csum=0;
235 icmp_out_count(icmp_param->icmph.type);
236 ip_build_xmit(sk, icmp_glue_bits, icmp_param,
237 icmp_param->data_len+sizeof(struct icmphdr),
238 daddr, saddr, &icmp_param->replyopts, 0, IPPROTO_ICMP);
239 }
240
241
242 /*
243 * Send an ICMP message in response to a situation
244 *
245 * RFC 1122: 3.2.2 MUST send at least the IP header and 8 bytes of header. MAY send more (we don't).
246 * MUST NOT change this header information.
247 * MUST NOT reply to a multicast/broadcast IP address.
248 * MUST NOT reply to a multicast/broadcast MAC address.
249 * MUST reply to only the first fragment.
250 */
251
252 void icmp_send(struct sk_buff *skb_in, int type, int code, unsigned long info, struct device *dev)
/* */
253 {
254 struct iphdr *iph;
255 struct icmphdr *icmph;
256 int atype;
257 struct icmp_bxm icmp_param;
258 __u32 saddr;
259
260 /*
261 * Find the original header
262 */
263
264 iph = skb_in->ip_hdr;
265
266 /*
267 * No replies to physical multicast/broadcast
268 */
269
270 if(skb_in->pkt_type!=PACKET_HOST)
271 return;
272
273 /*
274 * Now check at the protocol level
275 */
276
277 atype=ip_chk_addr(iph->daddr);
278 if(atype==IS_BROADCAST||atype==IS_MULTICAST)
279 return;
280
281 /*
282 * Only reply to fragment 0. We byte re-order the constant
283 * mask for efficiency.
284 */
285
286 if(iph->frag_off&htons(IP_OFFSET))
287 return;
288
289 /*
290 * If we send an ICMP error to an ICMP error a mess would result..
291 */
292
293 if(icmp_pointers[type].error)
294 {
295 /*
296 * We are an error, check if we are replying to an ICMP error
297 */
298
299 if(iph->protocol==IPPROTO_ICMP)
300 {
301 icmph = (struct icmphdr *)((char *)iph + (iph->ihl<<2));
302 /*
303 * Assume any unknown ICMP type is an error. This isn't
304 * specified by the RFC, but think about it..
305 */
306 if(icmph->type>18 || icmp_pointers[icmph->type].error)
307 return;
308 }
309 }
310
311 /*
312 * Tell our driver what to send
313 */
314
315 saddr=iph->daddr;
316 if(saddr!=dev->pa_addr && ip_chk_addr(saddr)!=IS_MYADDR)
317 saddr=dev->pa_addr;
318
319 icmp_param.icmph.type=type;
320 icmp_param.icmph.code=code;
321 icmp_param.icmph.un.gateway = info;
322 icmp_param.data_ptr=iph;
323 icmp_param.data_len=(iph->ihl<<2)+8; /* RFC says return header + 8 bytes */
324
325 /*
326 * Set it to build.
327 */
328
329 if (ip_options_echo(&icmp_param.replyopts, NULL, saddr, iph->saddr, skb_in) == 0)
330 icmp_build_xmit(&icmp_param, saddr, iph->saddr);
331 }
332
333
334 /*
335 * Handle ICMP_DEST_UNREACH, ICMP_TIME_EXCEED, and ICMP_QUENCH.
336 */
337
338 static void icmp_unreach(struct icmphdr *icmph, struct sk_buff *skb, struct device *dev, __u32 saddr, __u32 daddr, int len)
/* */
339 {
340 struct iphdr *iph;
341 int hash;
342 struct inet_protocol *ipprot;
343 unsigned char *dp;
344
345 iph = (struct iphdr *) (icmph + 1);
346
347 dp= ((unsigned char *)iph)+(iph->ihl<<2);
348
349 if(icmph->type==ICMP_DEST_UNREACH)
350 {
351 switch(icmph->code & 15)
352 {
353 case ICMP_NET_UNREACH:
354 break;
355 case ICMP_HOST_UNREACH:
356 break;
357 case ICMP_PROT_UNREACH:
358 printk("ICMP: %s:%d: protocol unreachable.\n",
359 in_ntoa(iph->daddr), ntohs(iph->protocol));
360 break;
361 case ICMP_PORT_UNREACH:
362 break;
363 case ICMP_FRAG_NEEDED:
364 printk("ICMP: %s: fragmentation needed and DF set.\n",
365 in_ntoa(iph->daddr));
366 break;
367 case ICMP_SR_FAILED:
368 printk("ICMP: %s: Source Route Failed.\n", in_ntoa(iph->daddr));
369 break;
370 default:
371 break;
372 }
373 if(icmph->code>12) /* Invalid type */
374 return;
375 }
376
377 /*
378 * Throw it at our lower layers
379 *
380 * RFC 1122: 3.2.2 MUST extract the protocol ID from the passed header.
381 * RFC 1122: 3.2.2.1 MUST pass ICMP unreach messages to the transport layer.
382 * RFC 1122: 3.2.2.2 MUST pass ICMP time expired messages to transport layer.
383 */
384
385 /*
386 * Get the protocol(s).
387 */
388
389 hash = iph->protocol & (MAX_INET_PROTOS -1);
390
391 /*
392 * This can't change while we are doing it.
393 *
394 * FIXME: Deliver to appropriate raw sockets too.
395 */
396
397 ipprot = (struct inet_protocol *) inet_protos[hash];
398 while(ipprot != NULL)
399 {
400 struct inet_protocol *nextip;
401
402 nextip = (struct inet_protocol *) ipprot->next;
403
404 /*
405 * Pass it off to everyone who wants it.
406 */
407
408 /* RFC1122: OK. Passes appropriate ICMP errors to the */
409 /* appropriate protocol layer (MUST), as per 3.2.2. */
410
411 if (iph->protocol == ipprot->protocol && ipprot->err_handler)
412 {
413 ipprot->err_handler(icmph->type, icmph->code, dp,
414 iph->daddr, iph->saddr, ipprot);
415 }
416
417 ipprot = nextip;
418 }
419 kfree_skb(skb, FREE_READ);
420 }
421
422
423 /*
424 * Handle ICMP_REDIRECT.
425 */
426
427 static void icmp_redirect(struct icmphdr *icmph, struct sk_buff *skb, struct device *dev, __u32 source, __u32 daddr, int len)
/* */
428 {
429 #ifndef CONFIG_IP_FORWARD
430 struct rtable *rt;
431 #endif
432 struct iphdr *iph;
433 unsigned long ip;
434
435 /*
436 * Get the copied header of the packet that caused the redirect
437 */
438
439 iph = (struct iphdr *) (icmph + 1);
440 ip = iph->daddr;
441
442 #ifdef CONFIG_IP_FORWARD
443 /*
444 * We are a router. Routers should not respond to ICMP_REDIRECT messages.
445 */
446 printk("icmp: ICMP redirect from %s on %s ignored.\n", in_ntoa(source), dev->name);
447 #else
448 switch(icmph->code & 7)
449 {
450 case ICMP_REDIR_NET:
451 /*
452 * This causes a problem with subnetted networks. What we should do
453 * is use ICMP_ADDRESS to get the subnet mask of the problem route
454 * and set both. But we don't..
455 */
456 #ifdef not_a_good_idea
457 ip_rt_add((RTF_DYNAMIC | RTF_MODIFIED | RTF_GATEWAY),
458 ip, 0, icmph->un.gateway, dev,0, 0, 0);
459 #endif
460 /*
461 * As per RFC recommendations now handle it as
462 * a host redirect.
463 */
464
465 case ICMP_REDIR_HOST:
466 /*
467 * Add better route to host.
468 * But first check that the redirect
469 * comes from the old gateway..
470 * And make sure it's an ok host address
471 * (not some confused thing sending our
472 * address)
473 */
474 rt = ip_rt_route(ip, NULL, NULL);
475 if (!rt)
476 break;
477 if (rt->rt_gateway != source ||
478 ((icmph->un.gateway^dev->pa_addr)&dev->pa_mask) ||
479 ip_chk_addr(icmph->un.gateway))
480 break;
481 printk("ICMP redirect from %s\n", in_ntoa(source));
482 ip_rt_add((RTF_DYNAMIC | RTF_MODIFIED | RTF_HOST | RTF_GATEWAY),
483 ip, 0, icmph->un.gateway, dev,0, 0, 0, 0);
484 break;
485 case ICMP_REDIR_NETTOS:
486 case ICMP_REDIR_HOSTTOS:
487 printk("ICMP: cannot handle TOS redirects yet!\n");
488 break;
489 default:
490 break;
491 }
492 #endif
493 /*
494 * Discard the original packet
495 */
496
497 kfree_skb(skb, FREE_READ);
498 }
499
500 /*
501 * Handle ICMP_ECHO ("ping") requests.
502 *
503 * RFC 1122: 3.2.2.6 MUST have an echo server that answers ICMP echo requests.
504 * RFC 1122: 3.2.2.6 Data received in the ICMP_ECHO request MUST be included in the reply.
505 * See also WRT handling of options once they are done and working.
506 */
507
508 static void icmp_echo(struct icmphdr *icmph, struct sk_buff *skb, struct device *dev, __u32 saddr, __u32 daddr, int len)
/* */
509 {
510 struct icmp_bxm icmp_param;
511 icmp_param.icmph=*icmph;
512 icmp_param.icmph.type=ICMP_ECHOREPLY;
513 icmp_param.data_ptr=(icmph+1);
514 icmp_param.data_len=len;
515 if (ip_options_echo(&icmp_param.replyopts, NULL, daddr, saddr, skb)==0)
516 icmp_build_xmit(&icmp_param, daddr, saddr);
517 kfree_skb(skb, FREE_READ);
518 }
519
520 /*
521 * Handle ICMP Timestamp requests.
522 * RFC 1122: 3.2.2.8 MAY implement ICMP timestamp requests.
523 * SHOULD be in the kernel for minimum random latency.
524 * MUST be accurate to a few minutes.
525 * MUST be updated at least at 15Hz.
526 */
527
528 static void icmp_timestamp(struct icmphdr *icmph, struct sk_buff *skb, struct device *dev, __u32 saddr, __u32 daddr, int len)
/* */
529 {
530 __u32 times[3]; /* So the new timestamp works on ALPHA's.. */
531 struct icmp_bxm icmp_param;
532
533 /*
534 * Too short.
535 */
536
537 if(len<12)
538 {
539 icmp_statistics.IcmpInErrors++;
540 kfree_skb(skb, FREE_READ);
541 return;
542 }
543
544 /*
545 * Fill in the current time as ms since midnight UT:
546 */
547
548 {
549 struct timeval tv;
550 do_gettimeofday(&tv);
551 times[1] = htonl((tv.tv_sec % 86400) * 1000 + tv.tv_usec / 1000);
552 }
553 times[2] = times[1];
554 memcpy((void *)×[0], icmph+1, 4); /* Incoming stamp */
555 icmp_param.icmph=*icmph;
556 icmp_param.icmph.type=ICMP_TIMESTAMPREPLY;
557 icmp_param.icmph.code=0;
558 icmp_param.data_ptr=×
559 icmp_param.data_len=12;
560 if (ip_options_echo(&icmp_param.replyopts, NULL, daddr, saddr, skb)==0)
561 icmp_build_xmit(&icmp_param, daddr, saddr);
562 kfree_skb(skb,FREE_READ);
563 }
564
565
566 /*
567 * Handle ICMP_ADDRESS_MASK requests. (RFC950)
568 *
569 * RFC1122 (3.2.2.9). A host MUST only send replies to
570 * ADDRESS_MASK requests if it's been configured as an address mask
571 * agent. Receiving a request doesn't constitute implicit permission to
572 * act as one. Of course, implementing this correctly requires (SHOULD)
573 * a way to turn the functionality on and off. Another one for sysctl(),
574 * I guess. -- MS
575 * Botched with a CONFIG option for now - Linus add scts sysctl please..
576 */
577
578 static void icmp_address(struct icmphdr *icmph, struct sk_buff *skb, struct device *dev, __u32 saddr, __u32 daddr, int len)
/* */
579 {
580 #ifdef CONFIG_IP_ADDR_AGENT
581 __u32 answer;
582 struct icmp_bxm icmp_param;
583 icmp_param.icmph.type=ICMP_ADDRESSREPLY;
584 icmp_param.icmph.code=0;
585 icmp_param.icmph.un.echo.id = icmph->un.echo.id;
586 icmp_param.icmph.un.echo.sequence = icmph->un.echo.sequence;
587 icmp_param.data_ptr=&dev->pa_mask;
588 icmp_param.data_len=4;
589 if (ip_options_echo(&icmp_param.replyopts, NULL, daddr, saddr, skb)==0)
590 icmp_build_xmit(&icmp_param, daddr, saddr);
591 #endif
592 kfree_skb(skb, FREE_READ);
593 }
594
595 static void icmp_discard(struct icmphdr *icmph, struct sk_buff *skb, struct device *dev, __u32 saddr, __u32 daddr, int len)
/* */
596 {
597 kfree_skb(skb, FREE_READ);
598 }
599
600 /*
601 * Deal with incoming ICMP packets.
602 */
603
604 int icmp_rcv(struct sk_buff *skb, struct device *dev, struct options *opt,
/* */
605 __u32 daddr, unsigned short len,
606 __u32 saddr, int redo, struct inet_protocol *protocol)
607 {
608 struct icmphdr *icmph=(void *)skb->h.raw;
609 icmp_statistics.IcmpInMsgs++;
610
611 /*
612 * Validate the packet
613 */
614
615 if (ip_compute_csum((unsigned char *) icmph, len))
616 {
617 /* Failed checksum! */
618 icmp_statistics.IcmpInErrors++;
619 printk("ICMP: failed checksum from %s!\n", in_ntoa(saddr));
620 kfree_skb(skb, FREE_READ);
621 return(0);
622 }
623
624 /*
625 * 18 is the highest 'known' icmp type. Anything else is a mystery
626 *
627 * RFC 1122: 3.2.2 Unknown ICMP messages types MUST be silently discarded.
628 */
629
630 if(icmph->type > 18)
631 {
632 icmp_statistics.IcmpInErrors++; /* Is this right - or do we ignore ? */
633 kfree_skb(skb,FREE_READ);
634 return(0);
635 }
636
637 /*
638 * Parse the ICMP message
639 */
640
641 if (daddr!=dev->pa_addr && ip_chk_addr(daddr) != IS_MYADDR)
642 {
643 /*
644 * RFC 1122: 3.2.2.6 An ICMP_ECHO to broadcast MAY be silently ignored (we don't as it is used
645 * by some network mapping tools).
646 * RFC 1122: 3.2.2.8 An ICMP_TIMESTAMP MAY be silently discarded if to broadcast/multicast.
647 */
648 if (icmph->type != ICMP_ECHO)
649 {
650 icmp_statistics.IcmpInErrors++;
651 kfree_skb(skb, FREE_READ);
652 return(0);
653 }
654 /*
655 * Reply the multicast/broadcast using a legal
656 * interface - in this case the device we got
657 * it from.
658 */
659 daddr=dev->pa_addr;
660 }
661
662 len-=sizeof(struct icmphdr);
663 (*icmp_pointers[icmph->type].input)++;
664 (icmp_pointers[icmph->type].handler)(icmph,skb,skb->dev,saddr,daddr,len);
665 return 0;
666 }
667
668 /*
669 * This table is the definition of how we handle ICMP.
670 */
671
672 static struct icmp_control icmp_pointers[19] = {
673 /* ECHO REPLY (0) */
674 { &icmp_statistics.IcmpOutEchoReps, &icmp_statistics.IcmpInEchoReps, icmp_discard, 0 },
675 { &dummy, &icmp_statistics.IcmpInErrors, icmp_discard, 1 },
676 { &dummy, &icmp_statistics.IcmpInErrors, icmp_discard, 1 },
677 /* DEST UNREACH (3) */
678 { &icmp_statistics.IcmpOutDestUnreachs, &icmp_statistics.IcmpInDestUnreachs, icmp_unreach, 1 },
679 /* SOURCE QUENCH (4) */
680 { &icmp_statistics.IcmpOutSrcQuenchs, &icmp_statistics.IcmpInSrcQuenchs, icmp_unreach, 1 },
681 /* REDIRECT (5) */
682 { &icmp_statistics.IcmpOutRedirects, &icmp_statistics.IcmpInRedirects, icmp_redirect, 1 },
683 { &dummy, &icmp_statistics.IcmpInErrors, icmp_discard, 1 },
684 { &dummy, &icmp_statistics.IcmpInErrors, icmp_discard, 1 },
685 /* ECHO (8) */
686 { &icmp_statistics.IcmpOutEchos, &icmp_statistics.IcmpInEchos, icmp_echo, 0 },
687 { &dummy, &icmp_statistics.IcmpInErrors, icmp_discard, 1 },
688 { &dummy, &icmp_statistics.IcmpInErrors, icmp_discard, 1 },
689 /* TIME EXCEEDED (11) */
690 { &icmp_statistics.IcmpOutTimeExcds, &icmp_statistics.IcmpInTimeExcds, icmp_unreach, 1 },
691 /* PARAMETER PROBLEM (12) */
692 /* FIXME: RFC1122 3.2.2.5 - MUST pass PARAM_PROB messages to transport layer */
693 { &icmp_statistics.IcmpOutParmProbs, &icmp_statistics.IcmpInParmProbs, icmp_discard, 1 },
694 /* TIMESTAMP (13) */
695 { &icmp_statistics.IcmpOutTimestamps, &icmp_statistics.IcmpInTimestamps, icmp_timestamp, 0 },
696 /* TIMESTAMP REPLY (14) */
697 { &icmp_statistics.IcmpOutTimestampReps, &icmp_statistics.IcmpInTimestampReps, icmp_discard, 0 },
698 /* INFO (15) */
699 { &dummy, &dummy, icmp_discard, 0 },
700 /* INFO REPLY (16) */
701 { &dummy, &dummy, icmp_discard, 0 },
702 /* ADDR MASK (17) */
703 { &icmp_statistics.IcmpOutAddrMasks, &icmp_statistics.IcmpInAddrMasks, icmp_address, 0 },
704 /* ADDR MASK REPLY (18) */
705 { &icmp_statistics.IcmpOutAddrMaskReps, &icmp_statistics.IcmpInAddrMaskReps, icmp_discard, 0 }
706 };
707
708 void icmp_init(struct proto_ops *ops)
/* ![[last]](../icons/n_last.png)
*/
709 {
710 struct sock *sk;
711 int err;
712 icmp_socket.type=SOCK_RAW;
713 icmp_socket.ops=ops;
714 if((err=ops->create(&icmp_socket, IPPROTO_ICMP))<0)
715 panic("Failed to create the ICMP control socket.\n");
716 sk=icmp_socket.data;
717 sk->allocation=GFP_ATOMIC;
718 sk->num = 256; /* Don't receive any data */
719 }
720
![[bottom]](../icons/n_bottom.png){kind=icon}
*/