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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 * The Internet Protocol (IP) module.
7 *
8 * Version: @(#)ip.c 1.0.16b 9/1/93
9 *
10 * Authors: Ross Biro, <bir7@leland.Stanford.Edu>
11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12 * Donald Becker, <becker@super.org>
13 * Alan Cox, <gw4pts@gw4pts.ampr.org>
14 * Richard Underwood
15 * Stefan Becker, <stefanb@yello.ping.de>
16 *
17 *
18 * Fixes:
19 * Alan Cox : Commented a couple of minor bits of surplus code
20 * Alan Cox : Undefining IP_FORWARD doesn't include the code
21 * (just stops a compiler warning).
22 * Alan Cox : Frames with >=MAX_ROUTE record routes, strict routes or loose routes
23 * are junked rather than corrupting things.
24 * Alan Cox : Frames to bad broadcast subnets are dumped
25 * We used to process them non broadcast and
26 * boy could that cause havoc.
27 * Alan Cox : ip_forward sets the free flag on the
28 * new frame it queues. Still crap because
29 * it copies the frame but at least it
30 * doesn't eat memory too.
31 * Alan Cox : Generic queue code and memory fixes.
32 * Fred Van Kempen : IP fragment support (borrowed from NET2E)
33 * Gerhard Koerting: Forward fragmented frames correctly.
34 * Gerhard Koerting: Fixes to my fix of the above 8-).
35 * Gerhard Koerting: IP interface addressing fix.
36 * Linus Torvalds : More robustness checks
37 * Alan Cox : Even more checks: Still not as robust as it ought to be
38 * Alan Cox : Save IP header pointer for later
39 * Alan Cox : ip option setting
40 * Alan Cox : Use ip_tos/ip_ttl settings
41 * Alan Cox : Fragmentation bogosity removed
42 * (Thanks to Mark.Bush@prg.ox.ac.uk)
43 * Dmitry Gorodchanin : Send of a raw packet crash fix.
44 * Alan Cox : Silly ip bug when an overlength
45 * fragment turns up. Now frees the
46 * queue.
47 * Linus Torvalds/ : Memory leakage on fragmentation
48 * Alan Cox : handling.
49 * Gerhard Koerting: Forwarding uses IP priority hints
50 * Teemu Rantanen : Fragment problems.
51 * Alan Cox : General cleanup, comments and reformat
52 * Alan Cox : SNMP statistics
53 * Alan Cox : BSD address rule semantics. Also see
54 * UDP as there is a nasty checksum issue
55 * if you do things the wrong way.
56 * Alan Cox : Always defrag, moved IP_FORWARD to the config.in file
57 * Alan Cox : IP options adjust sk->priority.
58 * Pedro Roque : Fix mtu/length error in ip_forward.
59 * Alan Cox : Avoid ip_chk_addr when possible.
60 * Richard Underwood : IP multicasting.
61 * Alan Cox : Cleaned up multicast handlers.
62 * Alan Cox : RAW sockets demultiplex in the BSD style.
63 * Gunther Mayer : Fix the SNMP reporting typo
64 * Alan Cox : Always in group 224.0.0.1
65 * Alan Cox : Multicast loopback error for 224.0.0.1
66 * Alan Cox : IP_MULTICAST_LOOP option.
67 * Alan Cox : Use notifiers.
68 * Bjorn Ekwall : Removed ip_csum (from slhc.c too)
69 * Bjorn Ekwall : Moved ip_fast_csum to ip.h (inline!)
70 * Stefan Becker : Send out ICMP HOST REDIRECT
71 *
72 *
73 * To Fix:
74 * IP option processing is mostly not needed. ip_forward needs to know about routing rules
75 * and time stamp but that's about all. Use the route mtu field here too
76 * IP fragmentation wants rewriting cleanly. The RFC815 algorithm is much more efficient
77 * and could be made very efficient with the addition of some virtual memory hacks to permit
78 * the allocation of a buffer that can then be 'grown' by twiddling page tables.
79 * Output fragmentation wants updating along with the buffer management to use a single
80 * interleaved copy algorithm so that fragmenting has a one copy overhead. Actual packet
81 * output should probably do its own fragmentation at the UDP/RAW layer. TCP shouldn't cause
82 * fragmentation anyway.
83 *
84 * This program is free software; you can redistribute it and/or
85 * modify it under the terms of the GNU General Public License
86 * as published by the Free Software Foundation; either version
87 * 2 of the License, or (at your option) any later version.
88 */
89
90 #include <asm/segment.h>
91 #include <asm/system.h>
92 #include <linux/types.h>
93 #include <linux/kernel.h>
94 #include <linux/sched.h>
95 #include <linux/mm.h>
96 #include <linux/string.h>
97 #include <linux/errno.h>
98 #include <linux/config.h>
99
100 #include <linux/socket.h>
101 #include <linux/sockios.h>
102 #include <linux/in.h>
103 #include <linux/inet.h>
104 #include <linux/netdevice.h>
105 #include <linux/etherdevice.h>
106
107 #include "snmp.h"
108 #include "ip.h"
109 #include "protocol.h"
110 #include "route.h"
111 #include "tcp.h"
112 #include <linux/skbuff.h>
113 #include "sock.h"
114 #include "arp.h"
115 #include "icmp.h"
116 #include "raw.h"
117 #include <linux/igmp.h>
118 #include <linux/ip_fw.h>
119
120 #define CONFIG_IP_DEFRAG
121
122 extern int last_retran;
123 extern void sort_send(struct sock *sk);
124
125 #define min(a,b) ((a)<(b)?(a):(b))
126 #define LOOPBACK(x) (((x) & htonl(0xff000000)) == htonl(0x7f000000))
127
128 /*
129 * SNMP management statistics
130 */
131
132 #ifdef CONFIG_IP_FORWARD
133 struct ip_mib ip_statistics={1,64,}; /* Forwarding=Yes, Default TTL=64 */
134 #else
135 struct ip_mib ip_statistics={0,64,}; /* Forwarding=No, Default TTL=64 */
136 #endif
137
138 /*
139 * Handle the issuing of an ioctl() request
140 * for the ip device. This is scheduled to
141 * disappear
142 */
143
144 int ip_ioctl(struct sock *sk, int cmd, unsigned long arg)
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*/
145 {
146 switch(cmd)
147 {
148 default:
149 return(-EINVAL);
150 }
151 }
152
153
154 /* these two routines will do routing. */
155
156 static void
157 strict_route(struct iphdr *iph, struct options *opt)
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*/
158 {
159 }
160
161
162 static void
163 loose_route(struct iphdr *iph, struct options *opt)
/* */
164 {
165 }
166
167
168
169
170 /* This routine will check to see if we have lost a gateway. */
171 void
172 ip_route_check(unsigned long daddr)
/* */
173 {
174 }
175
176
177 #if 0
178 /* this routine puts the options at the end of an ip header. */
179 static int
180 build_options(struct iphdr *iph, struct options *opt)
/* */
181 {
182 unsigned char *ptr;
183 /* currently we don't support any options. */
184 ptr = (unsigned char *)(iph+1);
185 *ptr = 0;
186 return (4);
187 }
188 #endif
189
190
191 /*
192 * Take an skb, and fill in the MAC header.
193 */
194
195 static int ip_send(struct sk_buff *skb, unsigned long daddr, int len, struct device *dev, unsigned long saddr)
/* */
196 {
197 int mac = 0;
198
199 skb->dev = dev;
200 skb->arp = 1;
201 if (dev->hard_header)
202 {
203 /*
204 * Build a hardware header. Source address is our mac, destination unknown
205 * (rebuild header will sort this out)
206 */
207 mac = dev->hard_header(skb->data, dev, ETH_P_IP, NULL, NULL, len, skb);
208 if (mac < 0)
209 {
210 mac = -mac;
211 skb->arp = 0;
212 skb->raddr = daddr; /* next routing address */
213 }
214 }
215 return mac;
216 }
217
218 int ip_id_count = 0;
219
220 /*
221 * This routine builds the appropriate hardware/IP headers for
222 * the routine. It assumes that if *dev != NULL then the
223 * protocol knows what it's doing, otherwise it uses the
224 * routing/ARP tables to select a device struct.
225 */
226 int ip_build_header(struct sk_buff *skb, unsigned long saddr, unsigned long daddr,
/* */
227 struct device **dev, int type, struct options *opt, int len, int tos, int ttl)
228 {
229 static struct options optmem;
230 struct iphdr *iph;
231 struct rtable *rt;
232 unsigned char *buff;
233 unsigned long raddr;
234 int tmp;
235 unsigned long src;
236
237 buff = skb->data;
238
239 /*
240 * See if we need to look up the device.
241 */
242
243 #ifdef CONFIG_INET_MULTICAST
244 if(MULTICAST(daddr) && *dev==NULL && skb->sk && *skb->sk->ip_mc_name)
245 *dev=dev_get(skb->sk->ip_mc_name);
246 #endif
247 if (*dev == NULL)
248 {
249 if(skb->localroute)
250 rt = ip_rt_local(daddr, &optmem, &src);
251 else
252 rt = ip_rt_route(daddr, &optmem, &src);
253 if (rt == NULL)
254 {
255 ip_statistics.IpOutNoRoutes++;
256 return(-ENETUNREACH);
257 }
258
259 *dev = rt->rt_dev;
260 /*
261 * If the frame is from us and going off machine it MUST MUST MUST
262 * have the output device ip address and never the loopback
263 */
264 if (LOOPBACK(saddr) && !LOOPBACK(daddr))
265 saddr = src;/*rt->rt_dev->pa_addr;*/
266 raddr = rt->rt_gateway;
267
268 opt = &optmem;
269 }
270 else
271 {
272 /*
273 * We still need the address of the first hop.
274 */
275 if(skb->localroute)
276 rt = ip_rt_local(daddr, &optmem, &src);
277 else
278 rt = ip_rt_route(daddr, &optmem, &src);
279 /*
280 * If the frame is from us and going off machine it MUST MUST MUST
281 * have the output device ip address and never the loopback
282 */
283 if (LOOPBACK(saddr) && !LOOPBACK(daddr))
284 saddr = src;/*rt->rt_dev->pa_addr;*/
285
286 raddr = (rt == NULL) ? 0 : rt->rt_gateway;
287 }
288
289 /*
290 * No source addr so make it our addr
291 */
292 if (saddr == 0)
293 saddr = src;
294
295 /*
296 * No gateway so aim at the real destination
297 */
298 if (raddr == 0)
299 raddr = daddr;
300
301 /*
302 * Now build the MAC header.
303 */
304
305 tmp = ip_send(skb, raddr, len, *dev, saddr);
306 buff += tmp;
307 len -= tmp;
308
309 /*
310 * Book keeping
311 */
312
313 skb->dev = *dev;
314 skb->saddr = saddr;
315 if (skb->sk)
316 skb->sk->saddr = saddr;
317
318 /*
319 * Now build the IP header.
320 */
321
322 /*
323 * If we are using IPPROTO_RAW, then we don't need an IP header, since
324 * one is being supplied to us by the user
325 */
326
327 if(type == IPPROTO_RAW)
328 return (tmp);
329
330 iph = (struct iphdr *)buff;
331 iph->version = 4;
332 iph->tos = tos;
333 iph->frag_off = 0;
334 iph->ttl = ttl;
335 iph->daddr = daddr;
336 iph->saddr = saddr;
337 iph->protocol = type;
338 iph->ihl = 5;
339 skb->ip_hdr = iph;
340
341 /* Setup the IP options. */
342 #ifdef Not_Yet_Avail
343 build_options(iph, opt);
344 #endif
345
346 return(20 + tmp); /* IP header plus MAC header size */
347 }
348
349
350 static int
351 do_options(struct iphdr *iph, struct options *opt)
/* */
352 {
353 unsigned char *buff;
354 int done = 0;
355 int i, len = sizeof(struct iphdr);
356
357 /* Zero out the options. */
358 opt->record_route.route_size = 0;
359 opt->loose_route.route_size = 0;
360 opt->strict_route.route_size = 0;
361 opt->tstamp.ptr = 0;
362 opt->security = 0;
363 opt->compartment = 0;
364 opt->handling = 0;
365 opt->stream = 0;
366 opt->tcc = 0;
367 return(0);
368
369 /* Advance the pointer to start at the options. */
370 buff = (unsigned char *)(iph + 1);
371
372 /* Now start the processing. */
373 while (!done && len < iph->ihl*4) switch(*buff) {
374 case IPOPT_END:
375 done = 1;
376 break;
377 case IPOPT_NOOP:
378 buff++;
379 len++;
380 break;
381 case IPOPT_SEC:
382 buff++;
383 if (*buff != 11) return(1);
384 buff++;
385 opt->security = ntohs(*(unsigned short *)buff);
386 buff += 2;
387 opt->compartment = ntohs(*(unsigned short *)buff);
388 buff += 2;
389 opt->handling = ntohs(*(unsigned short *)buff);
390 buff += 2;
391 opt->tcc = ((*buff) << 16) + ntohs(*(unsigned short *)(buff+1));
392 buff += 3;
393 len += 11;
394 break;
395 case IPOPT_LSRR:
396 buff++;
397 if ((*buff - 3)% 4 != 0) return(1);
398 len += *buff;
399 opt->loose_route.route_size = (*buff -3)/4;
400 buff++;
401 if (*buff % 4 != 0) return(1);
402 opt->loose_route.pointer = *buff/4 - 1;
403 buff++;
404 buff++;
405 for (i = 0; i < opt->loose_route.route_size; i++) {
406 if(i>=MAX_ROUTE)
407 return(1);
408 opt->loose_route.route[i] = *(unsigned long *)buff;
409 buff += 4;
410 }
411 break;
412 case IPOPT_SSRR:
413 buff++;
414 if ((*buff - 3)% 4 != 0) return(1);
415 len += *buff;
416 opt->strict_route.route_size = (*buff -3)/4;
417 buff++;
418 if (*buff % 4 != 0) return(1);
419 opt->strict_route.pointer = *buff/4 - 1;
420 buff++;
421 buff++;
422 for (i = 0; i < opt->strict_route.route_size; i++) {
423 if(i>=MAX_ROUTE)
424 return(1);
425 opt->strict_route.route[i] = *(unsigned long *)buff;
426 buff += 4;
427 }
428 break;
429 case IPOPT_RR:
430 buff++;
431 if ((*buff - 3)% 4 != 0) return(1);
432 len += *buff;
433 opt->record_route.route_size = (*buff -3)/4;
434 buff++;
435 if (*buff % 4 != 0) return(1);
436 opt->record_route.pointer = *buff/4 - 1;
437 buff++;
438 buff++;
439 for (i = 0; i < opt->record_route.route_size; i++) {
440 if(i>=MAX_ROUTE)
441 return 1;
442 opt->record_route.route[i] = *(unsigned long *)buff;
443 buff += 4;
444 }
445 break;
446 case IPOPT_SID:
447 len += 4;
448 buff +=2;
449 opt->stream = *(unsigned short *)buff;
450 buff += 2;
451 break;
452 case IPOPT_TIMESTAMP:
453 buff++;
454 len += *buff;
455 if (*buff % 4 != 0) return(1);
456 opt->tstamp.len = *buff / 4 - 1;
457 buff++;
458 if ((*buff - 1) % 4 != 0) return(1);
459 opt->tstamp.ptr = (*buff-1)/4;
460 buff++;
461 opt->tstamp.x.full_char = *buff;
462 buff++;
463 for (i = 0; i < opt->tstamp.len; i++) {
464 opt->tstamp.data[i] = *(unsigned long *)buff;
465 buff += 4;
466 }
467 break;
468 default:
469 return(1);
470 }
471
472 if (opt->record_route.route_size == 0) {
473 if (opt->strict_route.route_size != 0) {
474 memcpy(&(opt->record_route), &(opt->strict_route),
475 sizeof(opt->record_route));
476 } else if (opt->loose_route.route_size != 0) {
477 memcpy(&(opt->record_route), &(opt->loose_route),
478 sizeof(opt->record_route));
479 }
480 }
481
482 if (opt->strict_route.route_size != 0 &&
483 opt->strict_route.route_size != opt->strict_route.pointer) {
484 strict_route(iph, opt);
485 return(0);
486 }
487
488 if (opt->loose_route.route_size != 0 &&
489 opt->loose_route.route_size != opt->loose_route.pointer) {
490 loose_route(iph, opt);
491 return(0);
492 }
493
494 return(0);
495 }
496
497 /*
498 * This routine does all the checksum computations that don't
499 * require anything special (like copying or special headers).
500 */
501
502 unsigned short ip_compute_csum(unsigned char * buff, int len)
/* */
503 {
504 unsigned long sum = 0;
505
506 /* Do the first multiple of 4 bytes and convert to 16 bits. */
507 if (len > 3)
508 {
509 __asm__("clc\n"
510 "1:\t"
511 "lodsl\n\t"
512 "adcl %%eax, %%ebx\n\t"
513 "loop 1b\n\t"
514 "adcl $0, %%ebx\n\t"
515 "movl %%ebx, %%eax\n\t"
516 "shrl $16, %%eax\n\t"
517 "addw %%ax, %%bx\n\t"
518 "adcw $0, %%bx"
519 : "=b" (sum) , "=S" (buff)
520 : "0" (sum), "c" (len >> 2) ,"1" (buff)
521 : "ax", "cx", "si", "bx" );
522 }
523 if (len & 2)
524 {
525 __asm__("lodsw\n\t"
526 "addw %%ax, %%bx\n\t"
527 "adcw $0, %%bx"
528 : "=b" (sum), "=S" (buff)
529 : "0" (sum), "1" (buff)
530 : "bx", "ax", "si");
531 }
532 if (len & 1)
533 {
534 __asm__("lodsb\n\t"
535 "movb $0, %%ah\n\t"
536 "addw %%ax, %%bx\n\t"
537 "adcw $0, %%bx"
538 : "=b" (sum), "=S" (buff)
539 : "0" (sum), "1" (buff)
540 : "bx", "ax", "si");
541 }
542 sum =~sum;
543 return(sum & 0xffff);
544 }
545
546 /*
547 * Generate a checksum for an outgoing IP datagram.
548 */
549
550 void ip_send_check(struct iphdr *iph)
/* */
551 {
552 iph->check = 0;
553 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
554 }
555
556 /************************ Fragment Handlers From NET2E **********************************/
557
558
559 /*
560 * This fragment handler is a bit of a heap. On the other hand it works quite
561 * happily and handles things quite well.
562 */
563
564 static struct ipq *ipqueue = NULL; /* IP fragment queue */
565
566 /*
567 * Create a new fragment entry.
568 */
569
570 static struct ipfrag *ip_frag_create(int offset, int end, struct sk_buff *skb, unsigned char *ptr)
/* */
571 {
572 struct ipfrag *fp;
573
574 fp = (struct ipfrag *) kmalloc(sizeof(struct ipfrag), GFP_ATOMIC);
575 if (fp == NULL)
576 {
577 printk("IP: frag_create: no memory left !\n");
578 return(NULL);
579 }
580 memset(fp, 0, sizeof(struct ipfrag));
581
582 /* Fill in the structure. */
583 fp->offset = offset;
584 fp->end = end;
585 fp->len = end - offset;
586 fp->skb = skb;
587 fp->ptr = ptr;
588
589 return(fp);
590 }
591
592
593 /*
594 * Find the correct entry in the "incomplete datagrams" queue for
595 * this IP datagram, and return the queue entry address if found.
596 */
597
598 static struct ipq *ip_find(struct iphdr *iph)
/* */
599 {
600 struct ipq *qp;
601 struct ipq *qplast;
602
603 cli();
604 qplast = NULL;
605 for(qp = ipqueue; qp != NULL; qplast = qp, qp = qp->next)
606 {
607 if (iph->id== qp->iph->id && iph->saddr == qp->iph->saddr &&
608 iph->daddr == qp->iph->daddr && iph->protocol == qp->iph->protocol)
609 {
610 del_timer(&qp->timer); /* So it doesn't vanish on us. The timer will be reset anyway */
611 sti();
612 return(qp);
613 }
614 }
615 sti();
616 return(NULL);
617 }
618
619
620 /*
621 * Remove an entry from the "incomplete datagrams" queue, either
622 * because we completed, reassembled and processed it, or because
623 * it timed out.
624 */
625
626 static void ip_free(struct ipq *qp)
/* */
627 {
628 struct ipfrag *fp;
629 struct ipfrag *xp;
630
631 /*
632 * Stop the timer for this entry.
633 */
634
635 del_timer(&qp->timer);
636
637 /* Remove this entry from the "incomplete datagrams" queue. */
638 cli();
639 if (qp->prev == NULL)
640 {
641 ipqueue = qp->next;
642 if (ipqueue != NULL)
643 ipqueue->prev = NULL;
644 }
645 else
646 {
647 qp->prev->next = qp->next;
648 if (qp->next != NULL)
649 qp->next->prev = qp->prev;
650 }
651
652 /* Release all fragment data. */
653
654 fp = qp->fragments;
655 while (fp != NULL)
656 {
657 xp = fp->next;
658 IS_SKB(fp->skb);
659 kfree_skb(fp->skb,FREE_READ);
660 kfree_s(fp, sizeof(struct ipfrag));
661 fp = xp;
662 }
663
664 /* Release the MAC header. */
665 kfree_s(qp->mac, qp->maclen);
666
667 /* Release the IP header. */
668 kfree_s(qp->iph, qp->ihlen + 8);
669
670 /* Finally, release the queue descriptor itself. */
671 kfree_s(qp, sizeof(struct ipq));
672 sti();
673 }
674
675
676 /*
677 * Oops- a fragment queue timed out. Kill it and send an ICMP reply.
678 */
679
680 static void ip_expire(unsigned long arg)
/* */
681 {
682 struct ipq *qp;
683
684 qp = (struct ipq *)arg;
685
686 /*
687 * Send an ICMP "Fragment Reassembly Timeout" message.
688 */
689
690 ip_statistics.IpReasmTimeout++;
691 ip_statistics.IpReasmFails++;
692 /* This if is always true... shrug */
693 if(qp->fragments!=NULL)
694 icmp_send(qp->fragments->skb,ICMP_TIME_EXCEEDED,
695 ICMP_EXC_FRAGTIME, 0, qp->dev);
696
697 /*
698 * Nuke the fragment queue.
699 */
700 ip_free(qp);
701 }
702
703
704 /*
705 * Add an entry to the 'ipq' queue for a newly received IP datagram.
706 * We will (hopefully :-) receive all other fragments of this datagram
707 * in time, so we just create a queue for this datagram, in which we
708 * will insert the received fragments at their respective positions.
709 */
710
711 static struct ipq *ip_create(struct sk_buff *skb, struct iphdr *iph, struct device *dev)
/* */
712 {
713 struct ipq *qp;
714 int maclen;
715 int ihlen;
716
717 qp = (struct ipq *) kmalloc(sizeof(struct ipq), GFP_ATOMIC);
718 if (qp == NULL)
719 {
720 printk("IP: create: no memory left !\n");
721 return(NULL);
722 skb->dev = qp->dev;
723 }
724 memset(qp, 0, sizeof(struct ipq));
725
726 /*
727 * Allocate memory for the MAC header.
728 *
729 * FIXME: We have a maximum MAC address size limit and define
730 * elsewhere. We should use it here and avoid the 3 kmalloc() calls
731 */
732
733 maclen = ((unsigned long) iph) - ((unsigned long) skb->data);
734 qp->mac = (unsigned char *) kmalloc(maclen, GFP_ATOMIC);
735 if (qp->mac == NULL)
736 {
737 printk("IP: create: no memory left !\n");
738 kfree_s(qp, sizeof(struct ipq));
739 return(NULL);
740 }
741
742 /*
743 * Allocate memory for the IP header (plus 8 octets for ICMP).
744 */
745
746 ihlen = (iph->ihl * sizeof(unsigned long));
747 qp->iph = (struct iphdr *) kmalloc(ihlen + 8, GFP_ATOMIC);
748 if (qp->iph == NULL)
749 {
750 printk("IP: create: no memory left !\n");
751 kfree_s(qp->mac, maclen);
752 kfree_s(qp, sizeof(struct ipq));
753 return(NULL);
754 }
755
756 /* Fill in the structure. */
757 memcpy(qp->mac, skb->data, maclen);
758 memcpy(qp->iph, iph, ihlen + 8);
759 qp->len = 0;
760 qp->ihlen = ihlen;
761 qp->maclen = maclen;
762 qp->fragments = NULL;
763 qp->dev = dev;
764
765 /* Start a timer for this entry. */
766 qp->timer.expires = IP_FRAG_TIME; /* about 30 seconds */
767 qp->timer.data = (unsigned long) qp; /* pointer to queue */
768 qp->timer.function = ip_expire; /* expire function */
769 add_timer(&qp->timer);
770
771 /* Add this entry to the queue. */
772 qp->prev = NULL;
773 cli();
774 qp->next = ipqueue;
775 if (qp->next != NULL)
776 qp->next->prev = qp;
777 ipqueue = qp;
778 sti();
779 return(qp);
780 }
781
782
783 /*
784 * See if a fragment queue is complete.
785 */
786
787 static int ip_done(struct ipq *qp)
/* */
788 {
789 struct ipfrag *fp;
790 int offset;
791
792 /* Only possible if we received the final fragment. */
793 if (qp->len == 0)
794 return(0);
795
796 /* Check all fragment offsets to see if they connect. */
797 fp = qp->fragments;
798 offset = 0;
799 while (fp != NULL)
800 {
801 if (fp->offset > offset)
802 return(0); /* fragment(s) missing */
803 offset = fp->end;
804 fp = fp->next;
805 }
806
807 /* All fragments are present. */
808 return(1);
809 }
810
811
812 /*
813 * Build a new IP datagram from all its fragments.
814 *
815 * FIXME: We copy here because we lack an effective way of handling lists
816 * of bits on input. Until the new skb data handling is in I'm not going
817 * to touch this with a bargepole. This also causes a 4Kish limit on
818 * packet sizes.
819 */
820
821 static struct sk_buff *ip_glue(struct ipq *qp)
/* */
822 {
823 struct sk_buff *skb;
824 struct iphdr *iph;
825 struct ipfrag *fp;
826 unsigned char *ptr;
827 int count, len;
828
829 /*
830 * Allocate a new buffer for the datagram.
831 */
832
833 len = qp->maclen + qp->ihlen + qp->len;
834
835 if ((skb = alloc_skb(len,GFP_ATOMIC)) == NULL)
836 {
837 ip_statistics.IpReasmFails++;
838 printk("IP: queue_glue: no memory for gluing queue 0x%X\n", (int) qp);
839 ip_free(qp);
840 return(NULL);
841 }
842
843 /* Fill in the basic details. */
844 skb->len = (len - qp->maclen);
845 skb->h.raw = skb->data;
846 skb->free = 1;
847
848 /* Copy the original MAC and IP headers into the new buffer. */
849 ptr = (unsigned char *) skb->h.raw;
850 memcpy(ptr, ((unsigned char *) qp->mac), qp->maclen);
851 ptr += qp->maclen;
852 memcpy(ptr, ((unsigned char *) qp->iph), qp->ihlen);
853 ptr += qp->ihlen;
854 skb->h.raw += qp->maclen;
855
856 count = 0;
857
858 /* Copy the data portions of all fragments into the new buffer. */
859 fp = qp->fragments;
860 while(fp != NULL)
861 {
862 if(count+fp->len > skb->len)
863 {
864 printk("Invalid fragment list: Fragment over size.\n");
865 ip_free(qp);
866 kfree_skb(skb,FREE_WRITE);
867 ip_statistics.IpReasmFails++;
868 return NULL;
869 }
870 memcpy((ptr + fp->offset), fp->ptr, fp->len);
871 count += fp->len;
872 fp = fp->next;
873 }
874
875 /* We glued together all fragments, so remove the queue entry. */
876 ip_free(qp);
877
878 /* Done with all fragments. Fixup the new IP header. */
879 iph = skb->h.iph;
880 iph->frag_off = 0;
881 iph->tot_len = htons((iph->ihl * sizeof(unsigned long)) + count);
882 skb->ip_hdr = iph;
883
884 ip_statistics.IpReasmOKs++;
885 return(skb);
886 }
887
888
889 /*
890 * Process an incoming IP datagram fragment.
891 */
892
893 static struct sk_buff *ip_defrag(struct iphdr *iph, struct sk_buff *skb, struct device *dev)
/* */
894 {
895 struct ipfrag *prev, *next;
896 struct ipfrag *tfp;
897 struct ipq *qp;
898 struct sk_buff *skb2;
899 unsigned char *ptr;
900 int flags, offset;
901 int i, ihl, end;
902
903 ip_statistics.IpReasmReqds++;
904
905 /* Find the entry of this IP datagram in the "incomplete datagrams" queue. */
906 qp = ip_find(iph);
907
908 /* Is this a non-fragmented datagram? */
909 offset = ntohs(iph->frag_off);
910 flags = offset & ~IP_OFFSET;
911 offset &= IP_OFFSET;
912 if (((flags & IP_MF) == 0) && (offset == 0))
913 {
914 if (qp != NULL)
915 ip_free(qp); /* Huh? How could this exist?? */
916 return(skb);
917 }
918
919 offset <<= 3; /* offset is in 8-byte chunks */
920
921 /*
922 * If the queue already existed, keep restarting its timer as long
923 * as we still are receiving fragments. Otherwise, create a fresh
924 * queue entry.
925 */
926
927 if (qp != NULL)
928 {
929 del_timer(&qp->timer);
930 qp->timer.expires = IP_FRAG_TIME; /* about 30 seconds */
931 qp->timer.data = (unsigned long) qp; /* pointer to queue */
932 qp->timer.function = ip_expire; /* expire function */
933 add_timer(&qp->timer);
934 }
935 else
936 {
937 /*
938 * If we failed to create it, then discard the frame
939 */
940 if ((qp = ip_create(skb, iph, dev)) == NULL)
941 {
942 skb->sk = NULL;
943 kfree_skb(skb, FREE_READ);
944 ip_statistics.IpReasmFails++;
945 return NULL;
946 }
947 }
948
949 /*
950 * Determine the position of this fragment.
951 */
952
953 ihl = (iph->ihl * sizeof(unsigned long));
954 end = offset + ntohs(iph->tot_len) - ihl;
955
956 /*
957 * Point into the IP datagram 'data' part.
958 */
959
960 ptr = skb->data + dev->hard_header_len + ihl;
961
962 /*
963 * Is this the final fragment?
964 */
965
966 if ((flags & IP_MF) == 0)
967 qp->len = end;
968
969 /*
970 * Find out which fragments are in front and at the back of us
971 * in the chain of fragments so far. We must know where to put
972 * this fragment, right?
973 */
974
975 prev = NULL;
976 for(next = qp->fragments; next != NULL; next = next->next)
977 {
978 if (next->offset > offset)
979 break; /* bingo! */
980 prev = next;
981 }
982
983 /*
984 * We found where to put this one.
985 * Check for overlap with preceding fragment, and, if needed,
986 * align things so that any overlaps are eliminated.
987 */
988 if (prev != NULL && offset < prev->end)
989 {
990 i = prev->end - offset;
991 offset += i; /* ptr into datagram */
992 ptr += i; /* ptr into fragment data */
993 }
994
995 /*
996 * Look for overlap with succeeding segments.
997 * If we can merge fragments, do it.
998 */
999
1000 for(; next != NULL; next = tfp)
1001 {
1002 tfp = next->next;
1003 if (next->offset >= end)
1004 break; /* no overlaps at all */
1005
1006 i = end - next->offset; /* overlap is 'i' bytes */
1007 next->len -= i; /* so reduce size of */
1008 next->offset += i; /* next fragment */
1009 next->ptr += i;
1010
1011 /*
1012 * If we get a frag size of <= 0, remove it and the packet
1013 * that it goes with.
1014 */
1015 if (next->len <= 0)
1016 {
1017 if (next->prev != NULL)
1018 next->prev->next = next->next;
1019 else
1020 qp->fragments = next->next;
1021
1022 if (tfp->next != NULL)
1023 next->next->prev = next->prev;
1024
1025 kfree_skb(next->skb,FREE_READ);
1026 kfree_s(next, sizeof(struct ipfrag));
1027 }
1028 }
1029
1030 /*
1031 * Insert this fragment in the chain of fragments.
1032 */
1033
1034 tfp = NULL;
1035 tfp = ip_frag_create(offset, end, skb, ptr);
1036
1037 /*
1038 * No memory to save the fragment - so throw the lot
1039 */
1040
1041 if (!tfp)
1042 {
1043 skb->sk = NULL;
1044 kfree_skb(skb, FREE_READ);
1045 return NULL;
1046 }
1047 tfp->prev = prev;
1048 tfp->next = next;
1049 if (prev != NULL)
1050 prev->next = tfp;
1051 else
1052 qp->fragments = tfp;
1053
1054 if (next != NULL)
1055 next->prev = tfp;
1056
1057 /*
1058 * OK, so we inserted this new fragment into the chain.
1059 * Check if we now have a full IP datagram which we can
1060 * bump up to the IP layer...
1061 */
1062
1063 if (ip_done(qp))
1064 {
1065 skb2 = ip_glue(qp); /* glue together the fragments */
1066 return(skb2);
1067 }
1068 return(NULL);
1069 }
1070
1071
1072 /*
1073 * This IP datagram is too large to be sent in one piece. Break it up into
1074 * smaller pieces (each of size equal to the MAC header plus IP header plus
1075 * a block of the data of the original IP data part) that will yet fit in a
1076 * single device frame, and queue such a frame for sending by calling the
1077 * ip_queue_xmit(). Note that this is recursion, and bad things will happen
1078 * if this function causes a loop...
1079 *
1080 * Yes this is inefficient, feel free to submit a quicker one.
1081 *
1082 * **Protocol Violation**
1083 * We copy all the options to each fragment. !FIXME!
1084 */
1085 void ip_fragment(struct sock *sk, struct sk_buff *skb, struct device *dev, int is_frag)
/* */
1086 {
1087 struct iphdr *iph;
1088 unsigned char *raw;
1089 unsigned char *ptr;
1090 struct sk_buff *skb2;
1091 int left, mtu, hlen, len;
1092 int offset;
1093 unsigned long flags;
1094
1095 /*
1096 * Point into the IP datagram header.
1097 */
1098
1099 raw = skb->data;
1100 iph = (struct iphdr *) (raw + dev->hard_header_len);
1101
1102 skb->ip_hdr = iph;
1103
1104 /*
1105 * Setup starting values.
1106 */
1107
1108 hlen = (iph->ihl * sizeof(unsigned long));
1109 left = ntohs(iph->tot_len) - hlen; /* Space per frame */
1110 hlen += dev->hard_header_len; /* Total header size */
1111 mtu = (dev->mtu - hlen); /* Size of data space */
1112 ptr = (raw + hlen); /* Where to start from */
1113
1114 /*
1115 * Check for any "DF" flag. [DF means do not fragment]
1116 */
1117
1118 if (ntohs(iph->frag_off) & IP_DF)
1119 {
1120 /*
1121 * Reply giving the MTU of the failed hop.
1122 */
1123 ip_statistics.IpFragFails++;
1124 icmp_send(skb,ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, dev->mtu, dev);
1125 return;
1126 }
1127
1128 /*
1129 * The protocol doesn't seem to say what to do in the case that the
1130 * frame + options doesn't fit the mtu. As it used to fall down dead
1131 * in this case we were fortunate it didn't happen
1132 */
1133
1134 if(mtu<8)
1135 {
1136 /* It's wrong but its better than nothing */
1137 icmp_send(skb,ICMP_DEST_UNREACH,ICMP_FRAG_NEEDED,dev->mtu, dev);
1138 ip_statistics.IpFragFails++;
1139 return;
1140 }
1141
1142 /*
1143 * Fragment the datagram.
1144 */
1145
1146 /*
1147 * The initial offset is 0 for a complete frame. When
1148 * fragmenting fragments its wherever this one starts.
1149 */
1150
1151 if (is_frag & 2)
1152 offset = (ntohs(iph->frag_off) & 0x1fff) << 3;
1153 else
1154 offset = 0;
1155
1156
1157 /*
1158 * Keep copying data until we run out.
1159 */
1160
1161 while(left > 0)
1162 {
1163 len = left;
1164 /* IF: it doesn't fit, use 'mtu' - the data space left */
1165 if (len > mtu)
1166 len = mtu;
1167 /* IF: we are not sending upto and including the packet end
1168 then align the next start on an eight byte boundary */
1169 if (len < left)
1170 {
1171 len/=8;
1172 len*=8;
1173 }
1174 /*
1175 * Allocate buffer.
1176 */
1177
1178 if ((skb2 = alloc_skb(len + hlen,GFP_ATOMIC)) == NULL)
1179 {
1180 printk("IP: frag: no memory for new fragment!\n");
1181 ip_statistics.IpFragFails++;
1182 return;
1183 }
1184
1185 /*
1186 * Set up data on packet
1187 */
1188
1189 skb2->arp = skb->arp;
1190 if(skb->free==0)
1191 printk("IP fragmenter: BUG free!=1 in fragmenter\n");
1192 skb2->free = 1;
1193 skb2->len = len + hlen;
1194 skb2->h.raw=(char *) skb2->data;
1195 /*
1196 * Charge the memory for the fragment to any owner
1197 * it might possess
1198 */
1199
1200 save_flags(flags);
1201 if (sk)
1202 {
1203 cli();
1204 sk->wmem_alloc += skb2->mem_len;
1205 skb2->sk=sk;
1206 }
1207 restore_flags(flags);
1208 skb2->raddr = skb->raddr; /* For rebuild_header - must be here */
1209
1210 /*
1211 * Copy the packet header into the new buffer.
1212 */
1213
1214 memcpy(skb2->h.raw, raw, hlen);
1215
1216 /*
1217 * Copy a block of the IP datagram.
1218 */
1219 memcpy(skb2->h.raw + hlen, ptr, len);
1220 left -= len;
1221
1222 skb2->h.raw+=dev->hard_header_len;
1223
1224 /*
1225 * Fill in the new header fields.
1226 */
1227 iph = (struct iphdr *)(skb2->h.raw/*+dev->hard_header_len*/);
1228 iph->frag_off = htons((offset >> 3));
1229 /*
1230 * Added AC : If we are fragmenting a fragment thats not the
1231 * last fragment then keep MF on each bit
1232 */
1233 if (left > 0 || (is_frag & 1))
1234 iph->frag_off |= htons(IP_MF);
1235 ptr += len;
1236 offset += len;
1237
1238 /*
1239 * Put this fragment into the sending queue.
1240 */
1241
1242 ip_statistics.IpFragCreates++;
1243
1244 ip_queue_xmit(sk, dev, skb2, 2);
1245 }
1246 ip_statistics.IpFragOKs++;
1247 }
1248
1249
1250
1251 #ifdef CONFIG_IP_FORWARD
1252
1253 /*
1254 * Forward an IP datagram to its next destination.
1255 */
1256
1257 static void ip_forward(struct sk_buff *skb, struct device *dev, int is_frag)
/* */
1258 {
1259 struct device *dev2; /* Output device */
1260 struct iphdr *iph; /* Our header */
1261 struct sk_buff *skb2; /* Output packet */
1262 struct rtable *rt; /* Route we use */
1263 unsigned char *ptr; /* Data pointer */
1264 unsigned long raddr; /* Router IP address */
1265
1266 /*
1267 * See if we are allowed to forward this.
1268 */
1269
1270 #ifdef CONFIG_IP_FIREWALL
1271 if(!ip_fw_chk(skb->h.iph, ip_fw_fwd_chain, ip_fw_fwd_policy))
1272 {
1273 return;
1274 }
1275 #endif
1276 /*
1277 * According to the RFC, we must first decrease the TTL field. If
1278 * that reaches zero, we must reply an ICMP control message telling
1279 * that the packet's lifetime expired.
1280 *
1281 * Exception:
1282 * We may not generate an ICMP for an ICMP. icmp_send does the
1283 * enforcement of this so we can forget it here. It is however
1284 * sometimes VERY important.
1285 */
1286
1287 iph = skb->h.iph;
1288 iph->ttl--;
1289 if (iph->ttl <= 0)
1290 {
1291 /* Tell the sender its packet died... */
1292 icmp_send(skb, ICMP_TIME_EXCEEDED, ICMP_EXC_TTL, 0, dev);
1293 return;
1294 }
1295
1296 /*
1297 * Re-compute the IP header checksum.
1298 * This is inefficient. We know what has happened to the header
1299 * and could thus adjust the checksum as Phil Karn does in KA9Q
1300 */
1301
1302 ip_send_check(iph);
1303
1304 /*
1305 * OK, the packet is still valid. Fetch its destination address,
1306 * and give it to the IP sender for further processing.
1307 */
1308
1309 rt = ip_rt_route(iph->daddr, NULL, NULL);
1310 if (rt == NULL)
1311 {
1312 /*
1313 * Tell the sender its packet cannot be delivered. Again
1314 * ICMP is screened later.
1315 */
1316 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_NET_UNREACH, 0, dev);
1317 return;
1318 }
1319
1320
1321 /*
1322 * Gosh. Not only is the packet valid; we even know how to
1323 * forward it onto its final destination. Can we say this
1324 * is being plain lucky?
1325 * If the router told us that there is no GW, use the dest.
1326 * IP address itself- we seem to be connected directly...
1327 */
1328
1329 raddr = rt->rt_gateway;
1330
1331 if (raddr != 0)
1332 {
1333 /*
1334 * There is a gateway so find the correct route for it.
1335 * Gateways cannot in turn be gatewayed.
1336 */
1337 rt = ip_rt_route(raddr, NULL, NULL);
1338 if (rt == NULL)
1339 {
1340 /*
1341 * Tell the sender its packet cannot be delivered...
1342 */
1343 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, dev);
1344 return;
1345 }
1346 if (rt->rt_gateway != 0)
1347 raddr = rt->rt_gateway;
1348 }
1349 else
1350 raddr = iph->daddr;
1351
1352 /*
1353 * Having picked a route we can now send the frame out.
1354 */
1355
1356 dev2 = rt->rt_dev;
1357
1358 /*
1359 * In IP you never have to forward a frame on the interface that it
1360 * arrived upon. We now generate an ICMP HOST REDIRECT giving the route
1361 * we calculated.
1362 */
1363 #ifdef IP_NO_ICMP_REDIRECT
1364 if (dev == dev2)
1365 return;
1366 #else
1367 if (dev == dev2)
1368 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, raddr, dev);
1369 #endif
1370
1371 /*
1372 * We now allocate a new buffer, and copy the datagram into it.
1373 * If the indicated interface is up and running, kick it.
1374 */
1375
1376 if (dev2->flags & IFF_UP)
1377 {
1378
1379 /*
1380 * Current design decrees we copy the packet. For identical header
1381 * lengths we could avoid it. The new skb code will let us push
1382 * data so the problem goes away then.
1383 */
1384
1385 skb2 = alloc_skb(dev2->hard_header_len + skb->len, GFP_ATOMIC);
1386 /*
1387 * This is rare and since IP is tolerant of network failures
1388 * quite harmless.
1389 */
1390 if (skb2 == NULL)
1391 {
1392 printk("\nIP: No memory available for IP forward\n");
1393 return;
1394 }
1395 ptr = skb2->data;
1396 skb2->free = 1;
1397 skb2->len = skb->len + dev2->hard_header_len;
1398 skb2->h.raw = ptr;
1399
1400 /*
1401 * Copy the packet data into the new buffer.
1402 */
1403 memcpy(ptr + dev2->hard_header_len, skb->h.raw, skb->len);
1404
1405 /* Now build the MAC header. */
1406 (void) ip_send(skb2, raddr, skb->len, dev2, dev2->pa_addr);
1407
1408 ip_statistics.IpForwDatagrams++;
1409
1410 /*
1411 * See if it needs fragmenting. Note in ip_rcv we tagged
1412 * the fragment type. This must be right so that
1413 * the fragmenter does the right thing.
1414 */
1415
1416 if(skb2->len > dev2->mtu + dev2->hard_header_len)
1417 {
1418 ip_fragment(NULL,skb2,dev2, is_frag);
1419 kfree_skb(skb2,FREE_WRITE);
1420 }
1421 else
1422 {
1423 #ifdef CONFIG_IP_ACCT
1424 /*
1425 * Count mapping we shortcut
1426 */
1427
1428 ip_acct_cnt(iph,ip_acct_chain);
1429 #endif
1430
1431 /*
1432 * Map service types to priority. We lie about
1433 * throughput being low priority, but its a good
1434 * choice to help improve general usage.
1435 */
1436 if(iph->tos & IPTOS_LOWDELAY)
1437 dev_queue_xmit(skb2, dev2, SOPRI_INTERACTIVE);
1438 else if(iph->tos & IPTOS_THROUGHPUT)
1439 dev_queue_xmit(skb2, dev2, SOPRI_BACKGROUND);
1440 else
1441 dev_queue_xmit(skb2, dev2, SOPRI_NORMAL);
1442 }
1443 }
1444 }
1445
1446
1447 #endif
1448
1449 /*
1450 * This function receives all incoming IP datagrams.
1451 */
1452
1453 int ip_rcv(struct sk_buff *skb, struct device *dev, struct packet_type *pt)
/* */
1454 {
1455 struct iphdr *iph = skb->h.iph;
1456 struct sock *raw_sk=NULL;
1457 unsigned char hash;
1458 unsigned char flag = 0;
1459 unsigned char opts_p = 0; /* Set iff the packet has options. */
1460 struct inet_protocol *ipprot;
1461 static struct options opt; /* since we don't use these yet, and they
1462 take up stack space. */
1463 int brd=IS_MYADDR;
1464 int is_frag=0;
1465
1466 ip_statistics.IpInReceives++;
1467
1468 /*
1469 * Tag the ip header of this packet so we can find it
1470 */
1471
1472 skb->ip_hdr = iph;
1473
1474 /*
1475 * Is the datagram acceptable?
1476 *
1477 * 1. Length at least the size of an ip header
1478 * 2. Version of 4
1479 * 3. Checksums correctly. [Speed optimisation for later, skip loopback checksums]
1480 * (4. We ought to check for IP multicast addresses and undefined types.. does this matter ?)
1481 */
1482
1483 if (skb->len<sizeof(struct iphdr) || iph->ihl<5 || iph->version != 4 || ip_fast_csum((unsigned char *)iph, iph->ihl) !=0)
1484 {
1485 ip_statistics.IpInHdrErrors++;
1486 kfree_skb(skb, FREE_WRITE);
1487 return(0);
1488 }
1489
1490 /*
1491 * See if the firewall wants to dispose of the packet.
1492 */
1493
1494 #ifdef CONFIG_IP_FIREWALL
1495
1496 if(!LOOPBACK(iph->daddr) && !ip_fw_chk(iph,ip_fw_blk_chain,
1497 ip_fw_blk_policy))
1498 {
1499 kfree_skb(skb, FREE_WRITE);
1500 return 0;
1501 }
1502
1503 #endif
1504
1505 /*
1506 * Our transport medium may have padded the buffer out. Now we know it
1507 * is IP we can trim to the true length of the frame.
1508 */
1509
1510 skb->len=ntohs(iph->tot_len);
1511
1512 /*
1513 * Next analyse the packet for options. Studies show under one packet in
1514 * a thousand have options....
1515 */
1516
1517 if (iph->ihl != 5)
1518 { /* Fast path for the typical optionless IP packet. */
1519 memset((char *) &opt, 0, sizeof(opt));
1520 if (do_options(iph, &opt) != 0)
1521 return 0;
1522 opts_p = 1;
1523 }
1524
1525 /*
1526 * Remember if the frame is fragmented.
1527 */
1528
1529 if(iph->frag_off)
1530 {
1531 if (iph->frag_off & 0x0020)
1532 is_frag|=1;
1533 /*
1534 * Last fragment ?
1535 */
1536
1537 if (ntohs(iph->frag_off) & 0x1fff)
1538 is_frag|=2;
1539 }
1540
1541 /*
1542 * Do any IP forwarding required. chk_addr() is expensive -- avoid it someday.
1543 *
1544 * This is inefficient. While finding out if it is for us we could also compute
1545 * the routing table entry. This is where the great unified cache theory comes
1546 * in as and when someone implements it
1547 *
1548 * For most hosts over 99% of packets match the first conditional
1549 * and don't go via ip_chk_addr. Note: brd is set to IS_MYADDR at
1550 * function entry.
1551 */
1552
1553 if ( iph->daddr != skb->dev->pa_addr && (brd = ip_chk_addr(iph->daddr)) == 0)
1554 {
1555 /*
1556 * Don't forward multicast or broadcast frames.
1557 */
1558
1559 if(skb->pkt_type!=PACKET_HOST || brd==IS_BROADCAST)
1560 {
1561 kfree_skb(skb,FREE_WRITE);
1562 return 0;
1563 }
1564
1565 /*
1566 * The packet is for another target. Forward the frame
1567 */
1568
1569 #ifdef CONFIG_IP_FORWARD
1570 ip_forward(skb, dev, is_frag);
1571 #else
1572 /* printk("Machine %lx tried to use us as a forwarder to %lx but we have forwarding disabled!\n",
1573 iph->saddr,iph->daddr);*/
1574 ip_statistics.IpInAddrErrors++;
1575 #endif
1576 /*
1577 * The forwarder is inefficient and copies the packet. We
1578 * free the original now.
1579 */
1580
1581 kfree_skb(skb, FREE_WRITE);
1582 return(0);
1583 }
1584
1585 #ifdef CONFIG_IP_MULTICAST
1586
1587 if(brd==IS_MULTICAST && iph->daddr!=IGMP_ALL_HOSTS && !(dev->flags&IFF_LOOPBACK))
1588 {
1589 /*
1590 * Check it is for one of our groups
1591 */
1592 struct ip_mc_list *ip_mc=dev->ip_mc_list;
1593 do
1594 {
1595 if(ip_mc==NULL)
1596 {
1597 kfree_skb(skb, FREE_WRITE);
1598 return 0;
1599 }
1600 if(ip_mc->multiaddr==iph->daddr)
1601 break;
1602 ip_mc=ip_mc->next;
1603 }
1604 while(1);
1605 }
1606 #endif
1607 /*
1608 * Account for the packet
1609 */
1610
1611 #ifdef CONFIG_IP_ACCT
1612 ip_acct_cnt(iph,ip_acct_chain);
1613 #endif
1614
1615 /*
1616 * Reassemble IP fragments.
1617 */
1618
1619 if(is_frag)
1620 {
1621 /* Defragment. Obtain the complete packet if there is one */
1622 skb=ip_defrag(iph,skb,dev);
1623 if(skb==NULL)
1624 return 0;
1625 skb->dev = dev;
1626 iph=skb->h.iph;
1627 }
1628
1629
1630
1631 /*
1632 * Point into the IP datagram, just past the header.
1633 */
1634
1635 skb->ip_hdr = iph;
1636 skb->h.raw += iph->ihl*4;
1637
1638 /*
1639 * Deliver to raw sockets. This is fun as to avoid copies we want to make no surplus copies.
1640 */
1641
1642 hash = iph->protocol & (SOCK_ARRAY_SIZE-1);
1643
1644 /* If there maybe a raw socket we must check - if not we don't care less */
1645 if((raw_sk=raw_prot.sock_array[hash])!=NULL)
1646 {
1647 struct sock *sknext=NULL;
1648 struct sk_buff *skb1;
1649 raw_sk=get_sock_raw(raw_sk, hash, iph->saddr, iph->daddr);
1650 if(raw_sk) /* Any raw sockets */
1651 {
1652 do
1653 {
1654 /* Find the next */
1655 sknext=get_sock_raw(raw_sk->next, hash, iph->saddr, iph->daddr);
1656 if(sknext)
1657 skb1=skb_clone(skb, GFP_ATOMIC);
1658 else
1659 break; /* One pending raw socket left */
1660 if(skb1)
1661 raw_rcv(raw_sk, skb1, dev, iph->saddr,iph->daddr);
1662 raw_sk=sknext;
1663 }
1664 while(raw_sk!=NULL);
1665 /* Here either raw_sk is the last raw socket, or NULL if none */
1666 /* We deliver to the last raw socket AFTER the protocol checks as it avoids a surplus copy */
1667 }
1668 }
1669
1670 /*
1671 * skb->h.raw now points at the protocol beyond the IP header.
1672 */
1673
1674 hash = iph->protocol & (MAX_INET_PROTOS -1);
1675 for (ipprot = (struct inet_protocol *)inet_protos[hash];ipprot != NULL;ipprot=(struct inet_protocol *)ipprot->next)
1676 {
1677 struct sk_buff *skb2;
1678
1679 if (ipprot->protocol != iph->protocol)
1680 continue;
1681 /*
1682 * See if we need to make a copy of it. This will
1683 * only be set if more than one protocol wants it.
1684 * and then not for the last one. If there is a pending
1685 * raw delivery wait for that
1686 */
1687 if (ipprot->copy || raw_sk)
1688 {
1689 skb2 = skb_clone(skb, GFP_ATOMIC);
1690 if(skb2==NULL)
1691 continue;
1692 }
1693 else
1694 {
1695 skb2 = skb;
1696 }
1697 flag = 1;
1698
1699 /*
1700 * Pass on the datagram to each protocol that wants it,
1701 * based on the datagram protocol. We should really
1702 * check the protocol handler's return values here...
1703 */
1704 ipprot->handler(skb2, dev, opts_p ? &opt : 0, iph->daddr,
1705 (ntohs(iph->tot_len) - (iph->ihl * 4)),
1706 iph->saddr, 0, ipprot);
1707
1708 }
1709
1710 /*
1711 * All protocols checked.
1712 * If this packet was a broadcast, we may *not* reply to it, since that
1713 * causes (proven, grin) ARP storms and a leakage of memory (i.e. all
1714 * ICMP reply messages get queued up for transmission...)
1715 */
1716
1717 if(raw_sk!=NULL) /* Shift to last raw user */
1718 raw_rcv(raw_sk, skb, dev, iph->saddr, iph->daddr);
1719 else if (!flag) /* Free and report errors */
1720 {
1721 if (brd != IS_BROADCAST && brd!=IS_MULTICAST)
1722 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PROT_UNREACH, 0, dev);
1723 kfree_skb(skb, FREE_WRITE);
1724 }
1725
1726 return(0);
1727 }
1728
1729 /*
1730 * Loop a packet back to the sender.
1731 */
1732
1733 static void ip_loopback(struct device *old_dev, struct sk_buff *skb)
/* */
1734 {
1735 extern struct device loopback_dev;
1736 struct device *dev=&loopback_dev;
1737 int len=skb->len-old_dev->hard_header_len;
1738 struct sk_buff *newskb=alloc_skb(len+dev->hard_header_len, GFP_ATOMIC);
1739
1740 if(newskb==NULL)
1741 return;
1742
1743 newskb->link3=NULL;
1744 newskb->sk=NULL;
1745 newskb->dev=dev;
1746 newskb->saddr=skb->saddr;
1747 newskb->daddr=skb->daddr;
1748 newskb->raddr=skb->raddr;
1749 newskb->free=1;
1750 newskb->lock=0;
1751 newskb->users=0;
1752 newskb->pkt_type=skb->pkt_type;
1753 newskb->len=len+dev->hard_header_len;
1754
1755
1756 newskb->ip_hdr=(struct iphdr *)(newskb->data+ip_send(newskb, skb->ip_hdr->daddr, len, dev, skb->ip_hdr->saddr));
1757 memcpy(newskb->ip_hdr,skb->ip_hdr,len);
1758
1759 /* Recurse. The device check against IFF_LOOPBACK will stop infinite recursion */
1760
1761 /*printk("Loopback output queued [%lX to %lX].\n", newskb->ip_hdr->saddr,newskb->ip_hdr->daddr);*/
1762 ip_queue_xmit(NULL, dev, newskb, 1);
1763 }
1764
1765
1766 /*
1767 * Queues a packet to be sent, and starts the transmitter
1768 * if necessary. if free = 1 then we free the block after
1769 * transmit, otherwise we don't. If free==2 we not only
1770 * free the block but also don't assign a new ip seq number.
1771 * This routine also needs to put in the total length,
1772 * and compute the checksum
1773 */
1774
1775 void ip_queue_xmit(struct sock *sk, struct device *dev,
/* */
1776 struct sk_buff *skb, int free)
1777 {
1778 struct iphdr *iph;
1779 unsigned char *ptr;
1780
1781 /* Sanity check */
1782 if (dev == NULL)
1783 {
1784 printk("IP: ip_queue_xmit dev = NULL\n");
1785 return;
1786 }
1787
1788 IS_SKB(skb);
1789
1790 /*
1791 * Do some book-keeping in the packet for later
1792 */
1793
1794
1795 skb->dev = dev;
1796 skb->when = jiffies;
1797
1798 /*
1799 * Find the IP header and set the length. This is bad
1800 * but once we get the skb data handling code in the
1801 * hardware will push its header sensibly and we will
1802 * set skb->ip_hdr to avoid this mess and the fixed
1803 * header length problem
1804 */
1805
1806 ptr = skb->data;
1807 ptr += dev->hard_header_len;
1808 iph = (struct iphdr *)ptr;
1809 skb->ip_hdr = iph;
1810 iph->tot_len = ntohs(skb->len-dev->hard_header_len);
1811
1812 /*
1813 * No reassigning numbers to fragments...
1814 */
1815
1816 if(free!=2)
1817 iph->id = htons(ip_id_count++);
1818 else
1819 free=1;
1820
1821 /* All buffers without an owner socket get freed */
1822 if (sk == NULL)
1823 free = 1;
1824
1825 skb->free = free;
1826
1827 /*
1828 * Do we need to fragment. Again this is inefficient.
1829 * We need to somehow lock the original buffer and use
1830 * bits of it.
1831 */
1832
1833 if(skb->len > dev->mtu + dev->hard_header_len)
1834 {
1835 ip_fragment(sk,skb,dev,0);
1836 IS_SKB(skb);
1837 kfree_skb(skb,FREE_WRITE);
1838 return;
1839 }
1840
1841 /*
1842 * Add an IP checksum
1843 */
1844
1845 ip_send_check(iph);
1846
1847 /*
1848 * Print the frame when debugging
1849 */
1850
1851 /*
1852 * More debugging. You cannot queue a packet already on a list
1853 * Spot this and moan loudly.
1854 */
1855 if (skb->next != NULL)
1856 {
1857 printk("ip_queue_xmit: next != NULL\n");
1858 skb_unlink(skb);
1859 }
1860
1861 /*
1862 * If a sender wishes the packet to remain unfreed
1863 * we add it to his send queue. This arguably belongs
1864 * in the TCP level since nobody else uses it. BUT
1865 * remember IPng might change all the rules.
1866 */
1867
1868 if (!free)
1869 {
1870 unsigned long flags;
1871 /* The socket now has more outstanding blocks */
1872
1873 sk->packets_out++;
1874
1875 /* Protect the list for a moment */
1876 save_flags(flags);
1877 cli();
1878
1879 if (skb->link3 != NULL)
1880 {
1881 printk("ip.c: link3 != NULL\n");
1882 skb->link3 = NULL;
1883 }
1884 if (sk->send_head == NULL)
1885 {
1886 sk->send_tail = skb;
1887 sk->send_head = skb;
1888 }
1889 else
1890 {
1891 sk->send_tail->link3 = skb;
1892 sk->send_tail = skb;
1893 }
1894 /* skb->link3 is NULL */
1895
1896 /* Interrupt restore */
1897 restore_flags(flags);
1898 }
1899 else
1900 /* Remember who owns the buffer */
1901 skb->sk = sk;
1902
1903 /*
1904 * If the indicated interface is up and running, send the packet.
1905 */
1906
1907 ip_statistics.IpOutRequests++;
1908 #ifdef CONFIG_IP_ACCT
1909 ip_acct_cnt(iph,ip_acct_chain);
1910 #endif
1911
1912 #ifdef CONFIG_IP_MULTICAST
1913
1914 /*
1915 * Multicasts are looped back for other local users
1916 */
1917
1918 if (MULTICAST(iph->daddr) && !(dev->flags&IFF_LOOPBACK))
1919 {
1920 if(sk==NULL || sk->ip_mc_loop)
1921 {
1922 if(iph->daddr==IGMP_ALL_HOSTS)
1923 ip_loopback(dev,skb);
1924 else
1925 {
1926 struct ip_mc_list *imc=dev->ip_mc_list;
1927 while(imc!=NULL)
1928 {
1929 if(imc->multiaddr==iph->daddr)
1930 {
1931 ip_loopback(dev,skb);
1932 break;
1933 }
1934 imc=imc->next;
1935 }
1936 }
1937 }
1938 /* Multicasts with ttl 0 must not go beyond the host */
1939
1940 if(skb->ip_hdr->ttl==0)
1941 {
1942 kfree_skb(skb, FREE_READ);
1943 return;
1944 }
1945 }
1946 #endif
1947 if((dev->flags&IFF_BROADCAST) && iph->daddr==dev->pa_brdaddr && !(dev->flags&IFF_LOOPBACK))
1948 ip_loopback(dev,skb);
1949
1950 if (dev->flags & IFF_UP)
1951 {
1952 /*
1953 * If we have an owner use its priority setting,
1954 * otherwise use NORMAL
1955 */
1956
1957 if (sk != NULL)
1958 {
1959 dev_queue_xmit(skb, dev, sk->priority);
1960 }
1961 else
1962 {
1963 dev_queue_xmit(skb, dev, SOPRI_NORMAL);
1964 }
1965 }
1966 else
1967 {
1968 ip_statistics.IpOutDiscards++;
1969 if (free)
1970 kfree_skb(skb, FREE_WRITE);
1971 }
1972 }
1973
1974
1975
1976 #ifdef CONFIG_IP_MULTICAST
1977
1978 /*
1979 * Write an multicast group list table for the IGMP daemon to
1980 * read.
1981 */
1982
1983 int ip_mc_procinfo(char *buffer, char **start, off_t offset, int length)
/* */
1984 {
1985 off_t pos=0, begin=0;
1986 struct ip_mc_list *im;
1987 unsigned long flags;
1988 int len=0;
1989 struct device *dev;
1990
1991 len=sprintf(buffer,"Device : Count\tGroup Users Timer\n");
1992 save_flags(flags);
1993 cli();
1994
1995 for(dev = dev_base; dev; dev = dev->next)
1996 {
1997 if((dev->flags&IFF_UP)&&(dev->flags&IFF_MULTICAST))
1998 {
1999 len+=sprintf(buffer+len,"%-10s: %5d\n",
2000 dev->name, dev->mc_count);
2001 for(im = dev->ip_mc_list; im; im = im->next)
2002 {
2003 len+=sprintf(buffer+len,
2004 "\t\t\t%08lX %5d %d:%08lX\n",
2005 im->multiaddr, im->users,
2006 im->tm_running, im->timer.expires);
2007 pos=begin+len;
2008 if(pos<offset)
2009 {
2010 len=0;
2011 begin=pos;
2012 }
2013 if(pos>offset+length)
2014 break;
2015 }
2016 }
2017 }
2018 restore_flags(flags);
2019 *start=buffer+(offset-begin);
2020 len-=(offset-begin);
2021 if(len>length)
2022 len=length;
2023 return len;
2024 }
2025
2026
2027 #endif
2028 /*
2029 * Socket option code for IP. This is the end of the line after any TCP,UDP etc options on
2030 * an IP socket.
2031 *
2032 * We implement IP_TOS (type of service), IP_TTL (time to live).
2033 *
2034 * Next release we will sort out IP_OPTIONS since for some people are kind of important.
2035 */
2036
2037 int ip_setsockopt(struct sock *sk, int level, int optname, char *optval, int optlen)
/* */
2038 {
2039 int val,err;
2040 #if defined(CONFIG_IP_FIREWALL) || defined(CONFIG_IP_ACCT)
2041 struct ip_fw tmp_fw;
2042 #endif
2043 if (optval == NULL)
2044 return(-EINVAL);
2045
2046 err=verify_area(VERIFY_READ, optval, sizeof(int));
2047 if(err)
2048 return err;
2049
2050 val = get_fs_long((unsigned long *)optval);
2051
2052 if(level!=SOL_IP)
2053 return -EOPNOTSUPP;
2054
2055 switch(optname)
2056 {
2057 case IP_TOS:
2058 if(val<0||val>255)
2059 return -EINVAL;
2060 sk->ip_tos=val;
2061 if(val==IPTOS_LOWDELAY)
2062 sk->priority=SOPRI_INTERACTIVE;
2063 if(val==IPTOS_THROUGHPUT)
2064 sk->priority=SOPRI_BACKGROUND;
2065 return 0;
2066 case IP_TTL:
2067 if(val<1||val>255)
2068 return -EINVAL;
2069 sk->ip_ttl=val;
2070 return 0;
2071 #ifdef CONFIG_IP_MULTICAST
2072 case IP_MULTICAST_TTL:
2073 {
2074 unsigned char ucval;
2075
2076 ucval=get_fs_byte((unsigned char *)optval);
2077 if(ucval<1||ucval>255)
2078 return -EINVAL;
2079 sk->ip_mc_ttl=(int)ucval;
2080 return 0;
2081 }
2082 case IP_MULTICAST_LOOP:
2083 {
2084 unsigned char ucval;
2085
2086 ucval=get_fs_byte((unsigned char *)optval);
2087 if(ucval!=0 && ucval!=1)
2088 return -EINVAL;
2089 sk->ip_mc_loop=(int)ucval;
2090 return 0;
2091 }
2092 case IP_MULTICAST_IF:
2093 {
2094 /* Not fully tested */
2095 struct in_addr addr;
2096 struct device *dev=NULL;
2097
2098 /*
2099 * Check the arguments are allowable
2100 */
2101
2102 err=verify_area(VERIFY_READ, optval, sizeof(addr));
2103 if(err)
2104 return err;
2105
2106 memcpy_fromfs(&addr,optval,sizeof(addr));
2107
2108 printk("MC bind %s\n", in_ntoa(addr.s_addr));
2109
2110 /*
2111 * What address has been requested
2112 */
2113
2114 if(addr.s_addr==INADDR_ANY) /* Default */
2115 {
2116 sk->ip_mc_name[0]=0;
2117 return 0;
2118 }
2119
2120 /*
2121 * Find the device
2122 */
2123
2124 for(dev = dev_base; dev; dev = dev->next)
2125 {
2126 if((dev->flags&IFF_UP)&&(dev->flags&IFF_MULTICAST)&&
2127 (dev->pa_addr==addr.s_addr))
2128 break;
2129 }
2130
2131 /*
2132 * Did we find one
2133 */
2134
2135 if(dev)
2136 {
2137 strcpy(sk->ip_mc_name,dev->name);
2138 return 0;
2139 }
2140 return -EADDRNOTAVAIL;
2141 }
2142
2143 case IP_ADD_MEMBERSHIP:
2144 {
2145
2146 /*
2147 * FIXME: Add/Del membership should have a semaphore protecting them from re-entry
2148 */
2149 struct ip_mreq mreq;
2150 static struct options optmem;
2151 unsigned long route_src;
2152 struct rtable *rt;
2153 struct device *dev=NULL;
2154
2155 /*
2156 * Check the arguments.
2157 */
2158
2159 err=verify_area(VERIFY_READ, optval, sizeof(mreq));
2160 if(err)
2161 return err;
2162
2163 memcpy_fromfs(&mreq,optval,sizeof(mreq));
2164
2165 /*
2166 * Get device for use later
2167 */
2168
2169 if(mreq.imr_interface.s_addr==INADDR_ANY)
2170 {
2171 /*
2172 * Not set so scan.
2173 */
2174 if((rt=ip_rt_route(mreq.imr_multiaddr.s_addr,&optmem, &route_src))!=NULL)
2175 {
2176 dev=rt->rt_dev;
2177 rt->rt_use--;
2178 }
2179 }
2180 else
2181 {
2182 /*
2183 * Find a suitable device.
2184 */
2185 for(dev = dev_base; dev; dev = dev->next)
2186 {
2187 if((dev->flags&IFF_UP)&&(dev->flags&IFF_MULTICAST)&&
2188 (dev->pa_addr==mreq.imr_interface.s_addr))
2189 break;
2190 }
2191 }
2192
2193 /*
2194 * No device, no cookies.
2195 */
2196
2197 if(!dev)
2198 return -ENODEV;
2199
2200 /*
2201 * Join group.
2202 */
2203
2204 return ip_mc_join_group(sk,dev,mreq.imr_multiaddr.s_addr);
2205 }
2206
2207 case IP_DROP_MEMBERSHIP:
2208 {
2209 struct ip_mreq mreq;
2210 struct rtable *rt;
2211 static struct options optmem;
2212 unsigned long route_src;
2213 struct device *dev=NULL;
2214
2215 /*
2216 * Check the arguments
2217 */
2218
2219 err=verify_area(VERIFY_READ, optval, sizeof(mreq));
2220 if(err)
2221 return err;
2222
2223 memcpy_fromfs(&mreq,optval,sizeof(mreq));
2224
2225 /*
2226 * Get device for use later
2227 */
2228
2229 if(mreq.imr_interface.s_addr==INADDR_ANY)
2230 {
2231 if((rt=ip_rt_route(mreq.imr_multiaddr.s_addr,&optmem, &route_src))!=NULL)
2232 {
2233 dev=rt->rt_dev;
2234 rt->rt_use--;
2235 }
2236 }
2237 else
2238 {
2239 for(dev = dev_base; dev; dev = dev->next)
2240 {
2241 if((dev->flags&IFF_UP)&& (dev->flags&IFF_MULTICAST)&&
2242 (dev->pa_addr==mreq.imr_interface.s_addr))
2243 break;
2244 }
2245 }
2246
2247 /*
2248 * Did we find a suitable device.
2249 */
2250
2251 if(!dev)
2252 return -ENODEV;
2253
2254 /*
2255 * Leave group
2256 */
2257
2258 return ip_mc_leave_group(sk,dev,mreq.imr_multiaddr.s_addr);
2259 }
2260 #endif
2261 #ifdef CONFIG_IP_FIREWALL
2262 case IP_FW_ADD_BLK:
2263 case IP_FW_DEL_BLK:
2264 case IP_FW_ADD_FWD:
2265 case IP_FW_DEL_FWD:
2266 case IP_FW_CHK_BLK:
2267 case IP_FW_CHK_FWD:
2268 case IP_FW_FLUSH_BLK:
2269 case IP_FW_FLUSH_FWD:
2270 case IP_FW_ZERO_BLK:
2271 case IP_FW_ZERO_FWD:
2272 case IP_FW_POLICY_BLK:
2273 case IP_FW_POLICY_FWD:
2274 if(!suser())
2275 return -EPERM;
2276 if(optlen>sizeof(tmp_fw) || optlen<1)
2277 return -EINVAL;
2278 err=verify_area(VERIFY_READ,optval,optlen);
2279 if(err)
2280 return err;
2281 memcpy_fromfs(&tmp_fw,optval,optlen);
2282 err=ip_fw_ctl(optname, &tmp_fw,optlen);
2283 return -err; /* -0 is 0 after all */
2284
2285 #endif
2286 #ifdef CONFIG_IP_ACCT
2287 case IP_ACCT_DEL:
2288 case IP_ACCT_ADD:
2289 case IP_ACCT_FLUSH:
2290 case IP_ACCT_ZERO:
2291 if(!suser())
2292 return -EPERM;
2293 if(optlen>sizeof(tmp_fw) || optlen<1)
2294 return -EINVAL;
2295 err=verify_area(VERIFY_READ,optval,optlen);
2296 if(err)
2297 return err;
2298 memcpy_fromfs(&tmp_fw, optval,optlen);
2299 err=ip_acct_ctl(optname, &tmp_fw,optlen);
2300 return -err; /* -0 is 0 after all */
2301 #endif
2302 /* IP_OPTIONS and friends go here eventually */
2303 default:
2304 return(-ENOPROTOOPT);
2305 }
2306 }
2307
2308 /*
2309 * Get the options. Note for future reference. The GET of IP options gets the
2310 * _received_ ones. The set sets the _sent_ ones.
2311 */
2312
2313 int ip_getsockopt(struct sock *sk, int level, int optname, char *optval, int *optlen)
/* */
2314 {
2315 int val,err;
2316 #ifdef CONFIG_IP_MULTICAST
2317 int len;
2318 #endif
2319
2320 if(level!=SOL_IP)
2321 return -EOPNOTSUPP;
2322
2323 switch(optname)
2324 {
2325 case IP_TOS:
2326 val=sk->ip_tos;
2327 break;
2328 case IP_TTL:
2329 val=sk->ip_ttl;
2330 break;
2331 #ifdef CONFIG_IP_MULTICAST
2332 case IP_MULTICAST_TTL:
2333 val=sk->ip_mc_ttl;
2334 break;
2335 case IP_MULTICAST_LOOP:
2336 val=sk->ip_mc_loop;
2337 break;
2338 case IP_MULTICAST_IF:
2339 err=verify_area(VERIFY_WRITE, optlen, sizeof(int));
2340 if(err)
2341 return err;
2342 len=strlen(sk->ip_mc_name);
2343 err=verify_area(VERIFY_WRITE, optval, len);
2344 if(err)
2345 return err;
2346 put_fs_long(len,(unsigned long *) optlen);
2347 memcpy_tofs((void *)optval,sk->ip_mc_name, len);
2348 return 0;
2349 #endif
2350 default:
2351 return(-ENOPROTOOPT);
2352 }
2353 err=verify_area(VERIFY_WRITE, optlen, sizeof(int));
2354 if(err)
2355 return err;
2356 put_fs_long(sizeof(int),(unsigned long *) optlen);
2357
2358 err=verify_area(VERIFY_WRITE, optval, sizeof(int));
2359 if(err)
2360 return err;
2361 put_fs_long(val,(unsigned long *)optval);
2362
2363 return(0);
2364 }
2365
2366 /*
2367 * IP protocol layer initialiser
2368 */
2369
2370 static struct packet_type ip_packet_type =
2371 {
2372 0, /* MUTTER ntohs(ETH_P_IP),*/
2373 NULL, /* All devices */
2374 ip_rcv,
2375 NULL,
2376 NULL,
2377 };
2378
2379 /*
2380 * Device notifier
2381 */
2382
2383 static int ip_rt_event(unsigned long event, void *ptr)
/* */
2384 {
2385 if(event==NETDEV_DOWN)
2386 ip_rt_flush(ptr);
2387 return NOTIFY_DONE;
2388 }
2389
2390 struct notifier_block ip_rt_notifier={
2391 ip_rt_event,
2392 NULL,
2393 0
2394 };
2395
2396 /*
2397 * IP registers the packet type and then calls the subprotocol initialisers
2398 */
2399
2400 void ip_init(void)
/* ![[last]](../icons/n_last.png)
*/
2401 {
2402 ip_packet_type.type=htons(ETH_P_IP);
2403 dev_add_pack(&ip_packet_type);
2404
2405 /* So we flush routes when a device is downed */
2406 register_netdevice_notifier(&ip_rt_notifier);
2407 /* ip_raw_init();
2408 ip_packet_init();
2409 ip_tcp_init();
2410 ip_udp_init();*/
2411 }
![[bottom]](../icons/n_bottom.png){kind=icon}
*/