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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 int err;
1272
1273 if((err=ip_fw_chk(skb->h.iph, dev, ip_fw_fwd_chain, ip_fw_fwd_policy))!=1)
1274 {
1275 if(err==-1)
1276 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, dev);
1277 return;
1278 }
1279 #endif
1280 /*
1281 * According to the RFC, we must first decrease the TTL field. If
1282 * that reaches zero, we must reply an ICMP control message telling
1283 * that the packet's lifetime expired.
1284 *
1285 * Exception:
1286 * We may not generate an ICMP for an ICMP. icmp_send does the
1287 * enforcement of this so we can forget it here. It is however
1288 * sometimes VERY important.
1289 */
1290
1291 iph = skb->h.iph;
1292 iph->ttl--;
1293 if (iph->ttl <= 0)
1294 {
1295 /* Tell the sender its packet died... */
1296 icmp_send(skb, ICMP_TIME_EXCEEDED, ICMP_EXC_TTL, 0, dev);
1297 return;
1298 }
1299
1300 /*
1301 * Re-compute the IP header checksum.
1302 * This is inefficient. We know what has happened to the header
1303 * and could thus adjust the checksum as Phil Karn does in KA9Q
1304 */
1305
1306 ip_send_check(iph);
1307
1308 /*
1309 * OK, the packet is still valid. Fetch its destination address,
1310 * and give it to the IP sender for further processing.
1311 */
1312
1313 rt = ip_rt_route(iph->daddr, NULL, NULL);
1314 if (rt == NULL)
1315 {
1316 /*
1317 * Tell the sender its packet cannot be delivered. Again
1318 * ICMP is screened later.
1319 */
1320 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_NET_UNREACH, 0, dev);
1321 return;
1322 }
1323
1324
1325 /*
1326 * Gosh. Not only is the packet valid; we even know how to
1327 * forward it onto its final destination. Can we say this
1328 * is being plain lucky?
1329 * If the router told us that there is no GW, use the dest.
1330 * IP address itself- we seem to be connected directly...
1331 */
1332
1333 raddr = rt->rt_gateway;
1334
1335 if (raddr != 0)
1336 {
1337 /*
1338 * There is a gateway so find the correct route for it.
1339 * Gateways cannot in turn be gatewayed.
1340 */
1341 rt = ip_rt_route(raddr, NULL, NULL);
1342 if (rt == NULL)
1343 {
1344 /*
1345 * Tell the sender its packet cannot be delivered...
1346 */
1347 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, dev);
1348 return;
1349 }
1350 if (rt->rt_gateway != 0)
1351 raddr = rt->rt_gateway;
1352 }
1353 else
1354 raddr = iph->daddr;
1355
1356 /*
1357 * Having picked a route we can now send the frame out.
1358 */
1359
1360 dev2 = rt->rt_dev;
1361
1362 /*
1363 * In IP you never have to forward a frame on the interface that it
1364 * arrived upon. We now generate an ICMP HOST REDIRECT giving the route
1365 * we calculated.
1366 */
1367 #ifdef IP_NO_ICMP_REDIRECT
1368 if (dev == dev2)
1369 return;
1370 #else
1371 if (dev == dev2)
1372 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, raddr, dev);
1373 #endif
1374
1375 /*
1376 * We now allocate a new buffer, and copy the datagram into it.
1377 * If the indicated interface is up and running, kick it.
1378 */
1379
1380 if (dev2->flags & IFF_UP)
1381 {
1382
1383 /*
1384 * Current design decrees we copy the packet. For identical header
1385 * lengths we could avoid it. The new skb code will let us push
1386 * data so the problem goes away then.
1387 */
1388
1389 skb2 = alloc_skb(dev2->hard_header_len + skb->len, GFP_ATOMIC);
1390 /*
1391 * This is rare and since IP is tolerant of network failures
1392 * quite harmless.
1393 */
1394 if (skb2 == NULL)
1395 {
1396 printk("\nIP: No memory available for IP forward\n");
1397 return;
1398 }
1399 ptr = skb2->data;
1400 skb2->free = 1;
1401 skb2->len = skb->len + dev2->hard_header_len;
1402 skb2->h.raw = ptr;
1403
1404 /*
1405 * Copy the packet data into the new buffer.
1406 */
1407 memcpy(ptr + dev2->hard_header_len, skb->h.raw, skb->len);
1408
1409 /* Now build the MAC header. */
1410 (void) ip_send(skb2, raddr, skb->len, dev2, dev2->pa_addr);
1411
1412 ip_statistics.IpForwDatagrams++;
1413
1414 /*
1415 * See if it needs fragmenting. Note in ip_rcv we tagged
1416 * the fragment type. This must be right so that
1417 * the fragmenter does the right thing.
1418 */
1419
1420 if(skb2->len > dev2->mtu + dev2->hard_header_len)
1421 {
1422 ip_fragment(NULL,skb2,dev2, is_frag);
1423 kfree_skb(skb2,FREE_WRITE);
1424 }
1425 else
1426 {
1427 #ifdef CONFIG_IP_ACCT
1428 /*
1429 * Count mapping we shortcut
1430 */
1431
1432 ip_acct_cnt(iph,dev,ip_acct_chain);
1433 #endif
1434
1435 /*
1436 * Map service types to priority. We lie about
1437 * throughput being low priority, but its a good
1438 * choice to help improve general usage.
1439 */
1440 if(iph->tos & IPTOS_LOWDELAY)
1441 dev_queue_xmit(skb2, dev2, SOPRI_INTERACTIVE);
1442 else if(iph->tos & IPTOS_THROUGHPUT)
1443 dev_queue_xmit(skb2, dev2, SOPRI_BACKGROUND);
1444 else
1445 dev_queue_xmit(skb2, dev2, SOPRI_NORMAL);
1446 }
1447 }
1448 }
1449
1450
1451 #endif
1452
1453 /*
1454 * This function receives all incoming IP datagrams.
1455 */
1456
1457 int ip_rcv(struct sk_buff *skb, struct device *dev, struct packet_type *pt)
/* */
1458 {
1459 struct iphdr *iph = skb->h.iph;
1460 struct sock *raw_sk=NULL;
1461 unsigned char hash;
1462 unsigned char flag = 0;
1463 unsigned char opts_p = 0; /* Set iff the packet has options. */
1464 struct inet_protocol *ipprot;
1465 static struct options opt; /* since we don't use these yet, and they
1466 take up stack space. */
1467 int brd=IS_MYADDR;
1468 int is_frag=0;
1469 #ifdef CONFIG_IP_FIREWALL
1470 int err;
1471 #endif
1472
1473 ip_statistics.IpInReceives++;
1474
1475 /*
1476 * Tag the ip header of this packet so we can find it
1477 */
1478
1479 skb->ip_hdr = iph;
1480
1481 /*
1482 * Is the datagram acceptable?
1483 *
1484 * 1. Length at least the size of an ip header
1485 * 2. Version of 4
1486 * 3. Checksums correctly. [Speed optimisation for later, skip loopback checksums]
1487 * (4. We ought to check for IP multicast addresses and undefined types.. does this matter ?)
1488 */
1489
1490 if (skb->len<sizeof(struct iphdr) || iph->ihl<5 || iph->version != 4 || ip_fast_csum((unsigned char *)iph, iph->ihl) !=0)
1491 {
1492 ip_statistics.IpInHdrErrors++;
1493 kfree_skb(skb, FREE_WRITE);
1494 return(0);
1495 }
1496
1497 /*
1498 * See if the firewall wants to dispose of the packet.
1499 */
1500
1501 #ifdef CONFIG_IP_FIREWALL
1502
1503 if ((err=ip_fw_chk(iph,dev,ip_fw_blk_chain,ip_fw_blk_policy))!=1)
1504 {
1505 if(err==-1)
1506 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0, dev);
1507 kfree_skb(skb, FREE_WRITE);
1508 return 0;
1509 }
1510
1511 #endif
1512
1513 /*
1514 * Our transport medium may have padded the buffer out. Now we know it
1515 * is IP we can trim to the true length of the frame.
1516 */
1517
1518 skb->len=ntohs(iph->tot_len);
1519
1520 /*
1521 * Next analyse the packet for options. Studies show under one packet in
1522 * a thousand have options....
1523 */
1524
1525 if (iph->ihl != 5)
1526 { /* Fast path for the typical optionless IP packet. */
1527 memset((char *) &opt, 0, sizeof(opt));
1528 if (do_options(iph, &opt) != 0)
1529 return 0;
1530 opts_p = 1;
1531 }
1532
1533 /*
1534 * Remember if the frame is fragmented.
1535 */
1536
1537 if(iph->frag_off)
1538 {
1539 if (iph->frag_off & 0x0020)
1540 is_frag|=1;
1541 /*
1542 * Last fragment ?
1543 */
1544
1545 if (ntohs(iph->frag_off) & 0x1fff)
1546 is_frag|=2;
1547 }
1548
1549 /*
1550 * Do any IP forwarding required. chk_addr() is expensive -- avoid it someday.
1551 *
1552 * This is inefficient. While finding out if it is for us we could also compute
1553 * the routing table entry. This is where the great unified cache theory comes
1554 * in as and when someone implements it
1555 *
1556 * For most hosts over 99% of packets match the first conditional
1557 * and don't go via ip_chk_addr. Note: brd is set to IS_MYADDR at
1558 * function entry.
1559 */
1560
1561 if ( iph->daddr != skb->dev->pa_addr && (brd = ip_chk_addr(iph->daddr)) == 0)
1562 {
1563 /*
1564 * Don't forward multicast or broadcast frames.
1565 */
1566
1567 if(skb->pkt_type!=PACKET_HOST || brd==IS_BROADCAST)
1568 {
1569 kfree_skb(skb,FREE_WRITE);
1570 return 0;
1571 }
1572
1573 /*
1574 * The packet is for another target. Forward the frame
1575 */
1576
1577 #ifdef CONFIG_IP_FORWARD
1578 ip_forward(skb, dev, is_frag);
1579 #else
1580 /* printk("Machine %lx tried to use us as a forwarder to %lx but we have forwarding disabled!\n",
1581 iph->saddr,iph->daddr);*/
1582 ip_statistics.IpInAddrErrors++;
1583 #endif
1584 /*
1585 * The forwarder is inefficient and copies the packet. We
1586 * free the original now.
1587 */
1588
1589 kfree_skb(skb, FREE_WRITE);
1590 return(0);
1591 }
1592
1593 #ifdef CONFIG_IP_MULTICAST
1594
1595 if(brd==IS_MULTICAST && iph->daddr!=IGMP_ALL_HOSTS && !(dev->flags&IFF_LOOPBACK))
1596 {
1597 /*
1598 * Check it is for one of our groups
1599 */
1600 struct ip_mc_list *ip_mc=dev->ip_mc_list;
1601 do
1602 {
1603 if(ip_mc==NULL)
1604 {
1605 kfree_skb(skb, FREE_WRITE);
1606 return 0;
1607 }
1608 if(ip_mc->multiaddr==iph->daddr)
1609 break;
1610 ip_mc=ip_mc->next;
1611 }
1612 while(1);
1613 }
1614 #endif
1615 /*
1616 * Account for the packet
1617 */
1618
1619 #ifdef CONFIG_IP_ACCT
1620 ip_acct_cnt(iph,dev, ip_acct_chain);
1621 #endif
1622
1623 /*
1624 * Reassemble IP fragments.
1625 */
1626
1627 if(is_frag)
1628 {
1629 /* Defragment. Obtain the complete packet if there is one */
1630 skb=ip_defrag(iph,skb,dev);
1631 if(skb==NULL)
1632 return 0;
1633 skb->dev = dev;
1634 iph=skb->h.iph;
1635 }
1636
1637
1638
1639 /*
1640 * Point into the IP datagram, just past the header.
1641 */
1642
1643 skb->ip_hdr = iph;
1644 skb->h.raw += iph->ihl*4;
1645
1646 /*
1647 * Deliver to raw sockets. This is fun as to avoid copies we want to make no surplus copies.
1648 */
1649
1650 hash = iph->protocol & (SOCK_ARRAY_SIZE-1);
1651
1652 /* If there maybe a raw socket we must check - if not we don't care less */
1653 if((raw_sk=raw_prot.sock_array[hash])!=NULL)
1654 {
1655 struct sock *sknext=NULL;
1656 struct sk_buff *skb1;
1657 raw_sk=get_sock_raw(raw_sk, hash, iph->saddr, iph->daddr);
1658 if(raw_sk) /* Any raw sockets */
1659 {
1660 do
1661 {
1662 /* Find the next */
1663 sknext=get_sock_raw(raw_sk->next, hash, iph->saddr, iph->daddr);
1664 if(sknext)
1665 skb1=skb_clone(skb, GFP_ATOMIC);
1666 else
1667 break; /* One pending raw socket left */
1668 if(skb1)
1669 raw_rcv(raw_sk, skb1, dev, iph->saddr,iph->daddr);
1670 raw_sk=sknext;
1671 }
1672 while(raw_sk!=NULL);
1673 /* Here either raw_sk is the last raw socket, or NULL if none */
1674 /* We deliver to the last raw socket AFTER the protocol checks as it avoids a surplus copy */
1675 }
1676 }
1677
1678 /*
1679 * skb->h.raw now points at the protocol beyond the IP header.
1680 */
1681
1682 hash = iph->protocol & (MAX_INET_PROTOS -1);
1683 for (ipprot = (struct inet_protocol *)inet_protos[hash];ipprot != NULL;ipprot=(struct inet_protocol *)ipprot->next)
1684 {
1685 struct sk_buff *skb2;
1686
1687 if (ipprot->protocol != iph->protocol)
1688 continue;
1689 /*
1690 * See if we need to make a copy of it. This will
1691 * only be set if more than one protocol wants it.
1692 * and then not for the last one. If there is a pending
1693 * raw delivery wait for that
1694 */
1695 if (ipprot->copy || raw_sk)
1696 {
1697 skb2 = skb_clone(skb, GFP_ATOMIC);
1698 if(skb2==NULL)
1699 continue;
1700 }
1701 else
1702 {
1703 skb2 = skb;
1704 }
1705 flag = 1;
1706
1707 /*
1708 * Pass on the datagram to each protocol that wants it,
1709 * based on the datagram protocol. We should really
1710 * check the protocol handler's return values here...
1711 */
1712 ipprot->handler(skb2, dev, opts_p ? &opt : 0, iph->daddr,
1713 (ntohs(iph->tot_len) - (iph->ihl * 4)),
1714 iph->saddr, 0, ipprot);
1715
1716 }
1717
1718 /*
1719 * All protocols checked.
1720 * If this packet was a broadcast, we may *not* reply to it, since that
1721 * causes (proven, grin) ARP storms and a leakage of memory (i.e. all
1722 * ICMP reply messages get queued up for transmission...)
1723 */
1724
1725 if(raw_sk!=NULL) /* Shift to last raw user */
1726 raw_rcv(raw_sk, skb, dev, iph->saddr, iph->daddr);
1727 else if (!flag) /* Free and report errors */
1728 {
1729 if (brd != IS_BROADCAST && brd!=IS_MULTICAST)
1730 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PROT_UNREACH, 0, dev);
1731 kfree_skb(skb, FREE_WRITE);
1732 }
1733
1734 return(0);
1735 }
1736
1737 /*
1738 * Loop a packet back to the sender.
1739 */
1740
1741 static void ip_loopback(struct device *old_dev, struct sk_buff *skb)
/* */
1742 {
1743 extern struct device loopback_dev;
1744 struct device *dev=&loopback_dev;
1745 int len=skb->len-old_dev->hard_header_len;
1746 struct sk_buff *newskb=alloc_skb(len+dev->hard_header_len, GFP_ATOMIC);
1747
1748 if(newskb==NULL)
1749 return;
1750
1751 newskb->link3=NULL;
1752 newskb->sk=NULL;
1753 newskb->dev=dev;
1754 newskb->saddr=skb->saddr;
1755 newskb->daddr=skb->daddr;
1756 newskb->raddr=skb->raddr;
1757 newskb->free=1;
1758 newskb->lock=0;
1759 newskb->users=0;
1760 newskb->pkt_type=skb->pkt_type;
1761 newskb->len=len+dev->hard_header_len;
1762
1763
1764 newskb->ip_hdr=(struct iphdr *)(newskb->data+ip_send(newskb, skb->ip_hdr->daddr, len, dev, skb->ip_hdr->saddr));
1765 memcpy(newskb->ip_hdr,skb->ip_hdr,len);
1766
1767 /* Recurse. The device check against IFF_LOOPBACK will stop infinite recursion */
1768
1769 /*printk("Loopback output queued [%lX to %lX].\n", newskb->ip_hdr->saddr,newskb->ip_hdr->daddr);*/
1770 ip_queue_xmit(NULL, dev, newskb, 1);
1771 }
1772
1773
1774 /*
1775 * Queues a packet to be sent, and starts the transmitter
1776 * if necessary. if free = 1 then we free the block after
1777 * transmit, otherwise we don't. If free==2 we not only
1778 * free the block but also don't assign a new ip seq number.
1779 * This routine also needs to put in the total length,
1780 * and compute the checksum
1781 */
1782
1783 void ip_queue_xmit(struct sock *sk, struct device *dev,
/* */
1784 struct sk_buff *skb, int free)
1785 {
1786 struct iphdr *iph;
1787 unsigned char *ptr;
1788
1789 /* Sanity check */
1790 if (dev == NULL)
1791 {
1792 printk("IP: ip_queue_xmit dev = NULL\n");
1793 return;
1794 }
1795
1796 IS_SKB(skb);
1797
1798 /*
1799 * Do some book-keeping in the packet for later
1800 */
1801
1802
1803 skb->dev = dev;
1804 skb->when = jiffies;
1805
1806 /*
1807 * Find the IP header and set the length. This is bad
1808 * but once we get the skb data handling code in the
1809 * hardware will push its header sensibly and we will
1810 * set skb->ip_hdr to avoid this mess and the fixed
1811 * header length problem
1812 */
1813
1814 ptr = skb->data;
1815 ptr += dev->hard_header_len;
1816 iph = (struct iphdr *)ptr;
1817 skb->ip_hdr = iph;
1818 iph->tot_len = ntohs(skb->len-dev->hard_header_len);
1819
1820 /*
1821 * No reassigning numbers to fragments...
1822 */
1823
1824 if(free!=2)
1825 iph->id = htons(ip_id_count++);
1826 else
1827 free=1;
1828
1829 /* All buffers without an owner socket get freed */
1830 if (sk == NULL)
1831 free = 1;
1832
1833 skb->free = free;
1834
1835 /*
1836 * Do we need to fragment. Again this is inefficient.
1837 * We need to somehow lock the original buffer and use
1838 * bits of it.
1839 */
1840
1841 if(skb->len > dev->mtu + dev->hard_header_len)
1842 {
1843 ip_fragment(sk,skb,dev,0);
1844 IS_SKB(skb);
1845 kfree_skb(skb,FREE_WRITE);
1846 return;
1847 }
1848
1849 /*
1850 * Add an IP checksum
1851 */
1852
1853 ip_send_check(iph);
1854
1855 /*
1856 * Print the frame when debugging
1857 */
1858
1859 /*
1860 * More debugging. You cannot queue a packet already on a list
1861 * Spot this and moan loudly.
1862 */
1863 if (skb->next != NULL)
1864 {
1865 printk("ip_queue_xmit: next != NULL\n");
1866 skb_unlink(skb);
1867 }
1868
1869 /*
1870 * If a sender wishes the packet to remain unfreed
1871 * we add it to his send queue. This arguably belongs
1872 * in the TCP level since nobody else uses it. BUT
1873 * remember IPng might change all the rules.
1874 */
1875
1876 if (!free)
1877 {
1878 unsigned long flags;
1879 /* The socket now has more outstanding blocks */
1880
1881 sk->packets_out++;
1882
1883 /* Protect the list for a moment */
1884 save_flags(flags);
1885 cli();
1886
1887 if (skb->link3 != NULL)
1888 {
1889 printk("ip.c: link3 != NULL\n");
1890 skb->link3 = NULL;
1891 }
1892 if (sk->send_head == NULL)
1893 {
1894 sk->send_tail = skb;
1895 sk->send_head = skb;
1896 }
1897 else
1898 {
1899 sk->send_tail->link3 = skb;
1900 sk->send_tail = skb;
1901 }
1902 /* skb->link3 is NULL */
1903
1904 /* Interrupt restore */
1905 restore_flags(flags);
1906 }
1907 else
1908 /* Remember who owns the buffer */
1909 skb->sk = sk;
1910
1911 /*
1912 * If the indicated interface is up and running, send the packet.
1913 */
1914
1915 ip_statistics.IpOutRequests++;
1916 #ifdef CONFIG_IP_ACCT
1917 ip_acct_cnt(iph,dev, ip_acct_chain);
1918 #endif
1919
1920 #ifdef CONFIG_IP_MULTICAST
1921
1922 /*
1923 * Multicasts are looped back for other local users
1924 */
1925
1926 if (MULTICAST(iph->daddr) && !(dev->flags&IFF_LOOPBACK))
1927 {
1928 if(sk==NULL || sk->ip_mc_loop)
1929 {
1930 if(iph->daddr==IGMP_ALL_HOSTS)
1931 ip_loopback(dev,skb);
1932 else
1933 {
1934 struct ip_mc_list *imc=dev->ip_mc_list;
1935 while(imc!=NULL)
1936 {
1937 if(imc->multiaddr==iph->daddr)
1938 {
1939 ip_loopback(dev,skb);
1940 break;
1941 }
1942 imc=imc->next;
1943 }
1944 }
1945 }
1946 /* Multicasts with ttl 0 must not go beyond the host */
1947
1948 if(skb->ip_hdr->ttl==0)
1949 {
1950 kfree_skb(skb, FREE_READ);
1951 return;
1952 }
1953 }
1954 #endif
1955 if((dev->flags&IFF_BROADCAST) && iph->daddr==dev->pa_brdaddr && !(dev->flags&IFF_LOOPBACK))
1956 ip_loopback(dev,skb);
1957
1958 if (dev->flags & IFF_UP)
1959 {
1960 /*
1961 * If we have an owner use its priority setting,
1962 * otherwise use NORMAL
1963 */
1964
1965 if (sk != NULL)
1966 {
1967 dev_queue_xmit(skb, dev, sk->priority);
1968 }
1969 else
1970 {
1971 dev_queue_xmit(skb, dev, SOPRI_NORMAL);
1972 }
1973 }
1974 else
1975 {
1976 ip_statistics.IpOutDiscards++;
1977 if (free)
1978 kfree_skb(skb, FREE_WRITE);
1979 }
1980 }
1981
1982
1983
1984 #ifdef CONFIG_IP_MULTICAST
1985
1986 /*
1987 * Write an multicast group list table for the IGMP daemon to
1988 * read.
1989 */
1990
1991 int ip_mc_procinfo(char *buffer, char **start, off_t offset, int length)
/* */
1992 {
1993 off_t pos=0, begin=0;
1994 struct ip_mc_list *im;
1995 unsigned long flags;
1996 int len=0;
1997 struct device *dev;
1998
1999 len=sprintf(buffer,"Device : Count\tGroup Users Timer\n");
2000 save_flags(flags);
2001 cli();
2002
2003 for(dev = dev_base; dev; dev = dev->next)
2004 {
2005 if((dev->flags&IFF_UP)&&(dev->flags&IFF_MULTICAST))
2006 {
2007 len+=sprintf(buffer+len,"%-10s: %5d\n",
2008 dev->name, dev->mc_count);
2009 for(im = dev->ip_mc_list; im; im = im->next)
2010 {
2011 len+=sprintf(buffer+len,
2012 "\t\t\t%08lX %5d %d:%08lX\n",
2013 im->multiaddr, im->users,
2014 im->tm_running, im->timer.expires);
2015 pos=begin+len;
2016 if(pos<offset)
2017 {
2018 len=0;
2019 begin=pos;
2020 }
2021 if(pos>offset+length)
2022 break;
2023 }
2024 }
2025 }
2026 restore_flags(flags);
2027 *start=buffer+(offset-begin);
2028 len-=(offset-begin);
2029 if(len>length)
2030 len=length;
2031 return len;
2032 }
2033
2034
2035 #endif
2036 /*
2037 * Socket option code for IP. This is the end of the line after any TCP,UDP etc options on
2038 * an IP socket.
2039 *
2040 * We implement IP_TOS (type of service), IP_TTL (time to live).
2041 *
2042 * Next release we will sort out IP_OPTIONS since for some people are kind of important.
2043 */
2044
2045 int ip_setsockopt(struct sock *sk, int level, int optname, char *optval, int optlen)
/* */
2046 {
2047 int val,err;
2048 #if defined(CONFIG_IP_FIREWALL) || defined(CONFIG_IP_ACCT)
2049 struct ip_fw tmp_fw;
2050 #endif
2051 if (optval == NULL)
2052 return(-EINVAL);
2053
2054 err=verify_area(VERIFY_READ, optval, sizeof(int));
2055 if(err)
2056 return err;
2057
2058 val = get_fs_long((unsigned long *)optval);
2059
2060 if(level!=SOL_IP)
2061 return -EOPNOTSUPP;
2062
2063 switch(optname)
2064 {
2065 case IP_TOS:
2066 if(val<0||val>255)
2067 return -EINVAL;
2068 sk->ip_tos=val;
2069 if(val==IPTOS_LOWDELAY)
2070 sk->priority=SOPRI_INTERACTIVE;
2071 if(val==IPTOS_THROUGHPUT)
2072 sk->priority=SOPRI_BACKGROUND;
2073 return 0;
2074 case IP_TTL:
2075 if(val<1||val>255)
2076 return -EINVAL;
2077 sk->ip_ttl=val;
2078 return 0;
2079 #ifdef CONFIG_IP_MULTICAST
2080 case IP_MULTICAST_TTL:
2081 {
2082 unsigned char ucval;
2083
2084 ucval=get_fs_byte((unsigned char *)optval);
2085 if(ucval<1||ucval>255)
2086 return -EINVAL;
2087 sk->ip_mc_ttl=(int)ucval;
2088 return 0;
2089 }
2090 case IP_MULTICAST_LOOP:
2091 {
2092 unsigned char ucval;
2093
2094 ucval=get_fs_byte((unsigned char *)optval);
2095 if(ucval!=0 && ucval!=1)
2096 return -EINVAL;
2097 sk->ip_mc_loop=(int)ucval;
2098 return 0;
2099 }
2100 case IP_MULTICAST_IF:
2101 {
2102 /* Not fully tested */
2103 struct in_addr addr;
2104 struct device *dev=NULL;
2105
2106 /*
2107 * Check the arguments are allowable
2108 */
2109
2110 err=verify_area(VERIFY_READ, optval, sizeof(addr));
2111 if(err)
2112 return err;
2113
2114 memcpy_fromfs(&addr,optval,sizeof(addr));
2115
2116 printk("MC bind %s\n", in_ntoa(addr.s_addr));
2117
2118 /*
2119 * What address has been requested
2120 */
2121
2122 if(addr.s_addr==INADDR_ANY) /* Default */
2123 {
2124 sk->ip_mc_name[0]=0;
2125 return 0;
2126 }
2127
2128 /*
2129 * Find the device
2130 */
2131
2132 for(dev = dev_base; dev; dev = dev->next)
2133 {
2134 if((dev->flags&IFF_UP)&&(dev->flags&IFF_MULTICAST)&&
2135 (dev->pa_addr==addr.s_addr))
2136 break;
2137 }
2138
2139 /*
2140 * Did we find one
2141 */
2142
2143 if(dev)
2144 {
2145 strcpy(sk->ip_mc_name,dev->name);
2146 return 0;
2147 }
2148 return -EADDRNOTAVAIL;
2149 }
2150
2151 case IP_ADD_MEMBERSHIP:
2152 {
2153
2154 /*
2155 * FIXME: Add/Del membership should have a semaphore protecting them from re-entry
2156 */
2157 struct ip_mreq mreq;
2158 static struct options optmem;
2159 unsigned long route_src;
2160 struct rtable *rt;
2161 struct device *dev=NULL;
2162
2163 /*
2164 * Check the arguments.
2165 */
2166
2167 err=verify_area(VERIFY_READ, optval, sizeof(mreq));
2168 if(err)
2169 return err;
2170
2171 memcpy_fromfs(&mreq,optval,sizeof(mreq));
2172
2173 /*
2174 * Get device for use later
2175 */
2176
2177 if(mreq.imr_interface.s_addr==INADDR_ANY)
2178 {
2179 /*
2180 * Not set so scan.
2181 */
2182 if((rt=ip_rt_route(mreq.imr_multiaddr.s_addr,&optmem, &route_src))!=NULL)
2183 {
2184 dev=rt->rt_dev;
2185 rt->rt_use--;
2186 }
2187 }
2188 else
2189 {
2190 /*
2191 * Find a suitable device.
2192 */
2193 for(dev = dev_base; dev; dev = dev->next)
2194 {
2195 if((dev->flags&IFF_UP)&&(dev->flags&IFF_MULTICAST)&&
2196 (dev->pa_addr==mreq.imr_interface.s_addr))
2197 break;
2198 }
2199 }
2200
2201 /*
2202 * No device, no cookies.
2203 */
2204
2205 if(!dev)
2206 return -ENODEV;
2207
2208 /*
2209 * Join group.
2210 */
2211
2212 return ip_mc_join_group(sk,dev,mreq.imr_multiaddr.s_addr);
2213 }
2214
2215 case IP_DROP_MEMBERSHIP:
2216 {
2217 struct ip_mreq mreq;
2218 struct rtable *rt;
2219 static struct options optmem;
2220 unsigned long route_src;
2221 struct device *dev=NULL;
2222
2223 /*
2224 * Check the arguments
2225 */
2226
2227 err=verify_area(VERIFY_READ, optval, sizeof(mreq));
2228 if(err)
2229 return err;
2230
2231 memcpy_fromfs(&mreq,optval,sizeof(mreq));
2232
2233 /*
2234 * Get device for use later
2235 */
2236
2237 if(mreq.imr_interface.s_addr==INADDR_ANY)
2238 {
2239 if((rt=ip_rt_route(mreq.imr_multiaddr.s_addr,&optmem, &route_src))!=NULL)
2240 {
2241 dev=rt->rt_dev;
2242 rt->rt_use--;
2243 }
2244 }
2245 else
2246 {
2247 for(dev = dev_base; dev; dev = dev->next)
2248 {
2249 if((dev->flags&IFF_UP)&& (dev->flags&IFF_MULTICAST)&&
2250 (dev->pa_addr==mreq.imr_interface.s_addr))
2251 break;
2252 }
2253 }
2254
2255 /*
2256 * Did we find a suitable device.
2257 */
2258
2259 if(!dev)
2260 return -ENODEV;
2261
2262 /*
2263 * Leave group
2264 */
2265
2266 return ip_mc_leave_group(sk,dev,mreq.imr_multiaddr.s_addr);
2267 }
2268 #endif
2269 #ifdef CONFIG_IP_FIREWALL
2270 case IP_FW_ADD_BLK:
2271 case IP_FW_DEL_BLK:
2272 case IP_FW_ADD_FWD:
2273 case IP_FW_DEL_FWD:
2274 case IP_FW_CHK_BLK:
2275 case IP_FW_CHK_FWD:
2276 case IP_FW_FLUSH_BLK:
2277 case IP_FW_FLUSH_FWD:
2278 case IP_FW_ZERO_BLK:
2279 case IP_FW_ZERO_FWD:
2280 case IP_FW_POLICY_BLK:
2281 case IP_FW_POLICY_FWD:
2282 if(!suser())
2283 return -EPERM;
2284 if(optlen>sizeof(tmp_fw) || optlen<1)
2285 return -EINVAL;
2286 err=verify_area(VERIFY_READ,optval,optlen);
2287 if(err)
2288 return err;
2289 memcpy_fromfs(&tmp_fw,optval,optlen);
2290 err=ip_fw_ctl(optname, &tmp_fw,optlen);
2291 return -err; /* -0 is 0 after all */
2292
2293 #endif
2294 #ifdef CONFIG_IP_ACCT
2295 case IP_ACCT_DEL:
2296 case IP_ACCT_ADD:
2297 case IP_ACCT_FLUSH:
2298 case IP_ACCT_ZERO:
2299 if(!suser())
2300 return -EPERM;
2301 if(optlen>sizeof(tmp_fw) || optlen<1)
2302 return -EINVAL;
2303 err=verify_area(VERIFY_READ,optval,optlen);
2304 if(err)
2305 return err;
2306 memcpy_fromfs(&tmp_fw, optval,optlen);
2307 err=ip_acct_ctl(optname, &tmp_fw,optlen);
2308 return -err; /* -0 is 0 after all */
2309 #endif
2310 /* IP_OPTIONS and friends go here eventually */
2311 default:
2312 return(-ENOPROTOOPT);
2313 }
2314 }
2315
2316 /*
2317 * Get the options. Note for future reference. The GET of IP options gets the
2318 * _received_ ones. The set sets the _sent_ ones.
2319 */
2320
2321 int ip_getsockopt(struct sock *sk, int level, int optname, char *optval, int *optlen)
/* */
2322 {
2323 int val,err;
2324 #ifdef CONFIG_IP_MULTICAST
2325 int len;
2326 #endif
2327
2328 if(level!=SOL_IP)
2329 return -EOPNOTSUPP;
2330
2331 switch(optname)
2332 {
2333 case IP_TOS:
2334 val=sk->ip_tos;
2335 break;
2336 case IP_TTL:
2337 val=sk->ip_ttl;
2338 break;
2339 #ifdef CONFIG_IP_MULTICAST
2340 case IP_MULTICAST_TTL:
2341 val=sk->ip_mc_ttl;
2342 break;
2343 case IP_MULTICAST_LOOP:
2344 val=sk->ip_mc_loop;
2345 break;
2346 case IP_MULTICAST_IF:
2347 err=verify_area(VERIFY_WRITE, optlen, sizeof(int));
2348 if(err)
2349 return err;
2350 len=strlen(sk->ip_mc_name);
2351 err=verify_area(VERIFY_WRITE, optval, len);
2352 if(err)
2353 return err;
2354 put_fs_long(len,(unsigned long *) optlen);
2355 memcpy_tofs((void *)optval,sk->ip_mc_name, len);
2356 return 0;
2357 #endif
2358 default:
2359 return(-ENOPROTOOPT);
2360 }
2361 err=verify_area(VERIFY_WRITE, optlen, sizeof(int));
2362 if(err)
2363 return err;
2364 put_fs_long(sizeof(int),(unsigned long *) optlen);
2365
2366 err=verify_area(VERIFY_WRITE, optval, sizeof(int));
2367 if(err)
2368 return err;
2369 put_fs_long(val,(unsigned long *)optval);
2370
2371 return(0);
2372 }
2373
2374 /*
2375 * IP protocol layer initialiser
2376 */
2377
2378 static struct packet_type ip_packet_type =
2379 {
2380 0, /* MUTTER ntohs(ETH_P_IP),*/
2381 NULL, /* All devices */
2382 ip_rcv,
2383 NULL,
2384 NULL,
2385 };
2386
2387 /*
2388 * Device notifier
2389 */
2390
2391 static int ip_rt_event(unsigned long event, void *ptr)
/* */
2392 {
2393 if(event==NETDEV_DOWN)
2394 ip_rt_flush(ptr);
2395 return NOTIFY_DONE;
2396 }
2397
2398 struct notifier_block ip_rt_notifier={
2399 ip_rt_event,
2400 NULL,
2401 0
2402 };
2403
2404 /*
2405 * IP registers the packet type and then calls the subprotocol initialisers
2406 */
2407
2408 void ip_init(void)
/* ![[last]](../icons/n_last.png)
*/
2409 {
2410 ip_packet_type.type=htons(ETH_P_IP);
2411 dev_add_pack(&ip_packet_type);
2412
2413 /* So we flush routes when a device is downed */
2414 register_netdevice_notifier(&ip_rt_notifier);
2415 /* ip_raw_init();
2416 ip_packet_init();
2417 ip_tcp_init();
2418 ip_udp_init();*/
2419 }
![[bottom]](../icons/n_bottom.png){kind=icon}
*/