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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 *
16 * Fixes:
17 * Alan Cox : Commented a couple of minor bits of surplus code
18 * Alan Cox : Undefining IP_FORWARD doesn't include the code
19 * (just stops a compiler warning).
20 * Alan Cox : Frames with >=MAX_ROUTE record routes, strict routes or loose routes
21 * are junked rather than corrupting things.
22 * Alan Cox : Frames to bad broadcast subnets are dumped
23 * We used to process them non broadcast and
24 * boy could that cause havoc.
25 * Alan Cox : ip_forward sets the free flag on the
26 * new frame it queues. Still crap because
27 * it copies the frame but at least it
28 * doesn't eat memory too.
29 * Alan Cox : Generic queue code and memory fixes.
30 * Fred Van Kempen : IP fragment support (borrowed from NET2E)
31 * Gerhard Koerting: Forward fragmented frames correctly.
32 * Gerhard Koerting: Fixes to my fix of the above 8-).
33 * Gerhard Koerting: IP interface addressing fix.
34 * Linus Torvalds : More robustness checks
35 * Alan Cox : Even more checks: Still not as robust as it ought to be
36 * Alan Cox : Save IP header pointer for later
37 * Alan Cox : ip option setting
38 * Alan Cox : Use ip_tos/ip_ttl settings
39 * Alan Cox : Fragmentation bogosity removed
40 * (Thanks to Mark.Bush@prg.ox.ac.uk)
41 * Dmitry Gorodchanin : Send of a raw packet crash fix.
42 * Alan Cox : Silly ip bug when an overlength
43 * fragment turns up. Now frees the
44 * queue.
45 * Linus Torvalds/ : Memory leakage on fragmentation
46 * Alan Cox : handling.
47 * Gerhard Koerting: Forwarding uses IP priority hints
48 * Teemu Rantanen : Fragment problems.
49 * Alan Cox : General cleanup, comments and reformat
50 * Alan Cox : SNMP statistics
51 * Alan Cox : BSD address rule semantics. Also see
52 * UDP as there is a nasty checksum issue
53 * if you do things the wrong way.
54 * Alan Cox : Always defrag, moved IP_FORWARD to the config.in file
55 * Alan Cox : IP options adjust sk->priority.
56 * Pedro Roque : Fix mtu/length error in ip_forward.
57 * Alan Cox : Avoid ip_chk_addr when possible.
58 * Richard Underwood : IP multicasting.
59 * Alan Cox : Cleaned up multicast handlers.
60 * Alan Cox : RAW sockets demultiplex in the BSD style.
61 *
62 * To Fix:
63 * IP option processing is mostly not needed. ip_forward needs to know about routing rules
64 * and time stamp but that's about all. Use the route mtu field here too
65 *
66 * This program is free software; you can redistribute it and/or
67 * modify it under the terms of the GNU General Public License
68 * as published by the Free Software Foundation; either version
69 * 2 of the License, or (at your option) any later version.
70 */
71
72 #include <asm/segment.h>
73 #include <asm/system.h>
74 #include <linux/types.h>
75 #include <linux/kernel.h>
76 #include <linux/sched.h>
77 #include <linux/string.h>
78 #include <linux/errno.h>
79 #include <linux/socket.h>
80 #include <linux/sockios.h>
81 #include <linux/in.h>
82 #include <linux/inet.h>
83 #include <linux/netdevice.h>
84 #include <linux/etherdevice.h>
85 #include "snmp.h"
86 #include "ip.h"
87 #include "protocol.h"
88 #include "route.h"
89 #include "tcp.h"
90 #include <linux/skbuff.h>
91 #include "sock.h"
92 #include "arp.h"
93 #include "icmp.h"
94 #include "raw.h"
95 #include "igmp.h"
96 #include <linux/ip_fw.h>
97
98 #define CONFIG_IP_DEFRAG
99
100 extern int last_retran;
101 extern void sort_send(struct sock *sk);
102
103 #define min(a,b) ((a)<(b)?(a):(b))
104 #define LOOPBACK(x) (((x) & htonl(0xff000000)) == htonl(0x7f000000))
105
106 /*
107 * SNMP management statistics
108 */
109
110 #ifdef CONFIG_IP_FORWARDING
111 struct ip_mib ip_statistics={1,64,}; /* Forwarding=Yes, Default TTL=64 */
112 #else
113 struct ip_mib ip_statistics={1,64,}; /* Forwarding=No, Default TTL=64 */
114 #endif
115
116 #ifdef CONFIG_IP_MULTICAST
117
118 struct ip_mc_list *ip_mc_head=NULL;
119
120 #endif
121
122 /*
123 * Handle the issuing of an ioctl() request
124 * for the ip device. This is scheduled to
125 * disappear
126 */
127
128 int ip_ioctl(struct sock *sk, int cmd, unsigned long arg)
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*/
129 {
130 switch(cmd)
131 {
132 default:
133 return(-EINVAL);
134 }
135 }
136
137
138 /* these two routines will do routing. */
139
140 static void
141 strict_route(struct iphdr *iph, struct options *opt)
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*/
142 {
143 }
144
145
146 static void
147 loose_route(struct iphdr *iph, struct options *opt)
/* */
148 {
149 }
150
151
152
153
154 /* This routine will check to see if we have lost a gateway. */
155 void
156 ip_route_check(unsigned long daddr)
/* */
157 {
158 }
159
160
161 #if 0
162 /* this routine puts the options at the end of an ip header. */
163 static int
164 build_options(struct iphdr *iph, struct options *opt)
/* */
165 {
166 unsigned char *ptr;
167 /* currently we don't support any options. */
168 ptr = (unsigned char *)(iph+1);
169 *ptr = 0;
170 return (4);
171 }
172 #endif
173
174
175 /*
176 * Take an skb, and fill in the MAC header.
177 */
178
179 static int ip_send(struct sk_buff *skb, unsigned long daddr, int len, struct device *dev, unsigned long saddr)
/* */
180 {
181 int mac = 0;
182
183 skb->dev = dev;
184 skb->arp = 1;
185 if (dev->hard_header)
186 {
187 /*
188 * Build a hardware header. Source address is our mac, destination unknown
189 * (rebuild header will sort this out)
190 */
191 mac = dev->hard_header(skb->data, dev, ETH_P_IP, NULL, NULL, len, skb);
192 if (mac < 0)
193 {
194 mac = -mac;
195 skb->arp = 0;
196 skb->raddr = daddr; /* next routing address */
197 }
198 }
199 return mac;
200 }
201
202 int ip_id_count = 0;
203
204 /*
205 * This routine builds the appropriate hardware/IP headers for
206 * the routine. It assumes that if *dev != NULL then the
207 * protocol knows what it's doing, otherwise it uses the
208 * routing/ARP tables to select a device struct.
209 */
210 int ip_build_header(struct sk_buff *skb, unsigned long saddr, unsigned long daddr,
/* */
211 struct device **dev, int type, struct options *opt, int len, int tos, int ttl)
212 {
213 static struct options optmem;
214 struct iphdr *iph;
215 struct rtable *rt;
216 unsigned char *buff;
217 unsigned long raddr;
218 int tmp;
219 unsigned long src;
220
221 buff = skb->data;
222
223 /*
224 * See if we need to look up the device.
225 */
226
227 if (*dev == NULL)
228 {
229 if(skb->localroute)
230 rt = ip_rt_local(daddr, &optmem, &src);
231 else
232 rt = ip_rt_route(daddr, &optmem, &src);
233 if (rt == NULL)
234 {
235 ip_statistics.IpOutNoRoutes++;
236 return(-ENETUNREACH);
237 }
238
239 *dev = rt->rt_dev;
240 /*
241 * If the frame is from us and going off machine it MUST MUST MUST
242 * have the output device ip address and never the loopback
243 */
244 if (LOOPBACK(saddr) && !LOOPBACK(daddr))
245 saddr = src;/*rt->rt_dev->pa_addr;*/
246 raddr = rt->rt_gateway;
247
248 opt = &optmem;
249 }
250 else
251 {
252 /*
253 * We still need the address of the first hop.
254 */
255 if(skb->localroute)
256 rt = ip_rt_local(daddr, &optmem, &src);
257 else
258 rt = ip_rt_route(daddr, &optmem, &src);
259 /*
260 * If the frame is from us and going off machine it MUST MUST MUST
261 * have the output device ip address and never the loopback
262 */
263 if (LOOPBACK(saddr) && !LOOPBACK(daddr))
264 saddr = src;/*rt->rt_dev->pa_addr;*/
265
266 raddr = (rt == NULL) ? 0 : rt->rt_gateway;
267 }
268
269 /*
270 * No source addr so make it our addr
271 */
272 if (saddr == 0)
273 saddr = src;
274
275 /*
276 * No gateway so aim at the real destination
277 */
278 if (raddr == 0)
279 raddr = daddr;
280
281 /*
282 * Now build the MAC header.
283 */
284
285 tmp = ip_send(skb, raddr, len, *dev, saddr);
286 buff += tmp;
287 len -= tmp;
288
289 /*
290 * Book keeping
291 */
292
293 skb->dev = *dev;
294 skb->saddr = saddr;
295 if (skb->sk)
296 skb->sk->saddr = saddr;
297
298 /*
299 * Now build the IP header.
300 */
301
302 /*
303 * If we are using IPPROTO_RAW, then we don't need an IP header, since
304 * one is being supplied to us by the user
305 */
306
307 if(type == IPPROTO_RAW)
308 return (tmp);
309
310 iph = (struct iphdr *)buff;
311 iph->version = 4;
312 iph->tos = tos;
313 iph->frag_off = 0;
314 iph->ttl = ttl;
315 iph->daddr = daddr;
316 iph->saddr = saddr;
317 iph->protocol = type;
318 iph->ihl = 5;
319
320 /* Setup the IP options. */
321 #ifdef Not_Yet_Avail
322 build_options(iph, opt);
323 #endif
324
325 return(20 + tmp); /* IP header plus MAC header size */
326 }
327
328
329 static int
330 do_options(struct iphdr *iph, struct options *opt)
/* */
331 {
332 unsigned char *buff;
333 int done = 0;
334 int i, len = sizeof(struct iphdr);
335
336 /* Zero out the options. */
337 opt->record_route.route_size = 0;
338 opt->loose_route.route_size = 0;
339 opt->strict_route.route_size = 0;
340 opt->tstamp.ptr = 0;
341 opt->security = 0;
342 opt->compartment = 0;
343 opt->handling = 0;
344 opt->stream = 0;
345 opt->tcc = 0;
346 return(0);
347
348 /* Advance the pointer to start at the options. */
349 buff = (unsigned char *)(iph + 1);
350
351 /* Now start the processing. */
352 while (!done && len < iph->ihl*4) switch(*buff) {
353 case IPOPT_END:
354 done = 1;
355 break;
356 case IPOPT_NOOP:
357 buff++;
358 len++;
359 break;
360 case IPOPT_SEC:
361 buff++;
362 if (*buff != 11) return(1);
363 buff++;
364 opt->security = ntohs(*(unsigned short *)buff);
365 buff += 2;
366 opt->compartment = ntohs(*(unsigned short *)buff);
367 buff += 2;
368 opt->handling = ntohs(*(unsigned short *)buff);
369 buff += 2;
370 opt->tcc = ((*buff) << 16) + ntohs(*(unsigned short *)(buff+1));
371 buff += 3;
372 len += 11;
373 break;
374 case IPOPT_LSRR:
375 buff++;
376 if ((*buff - 3)% 4 != 0) return(1);
377 len += *buff;
378 opt->loose_route.route_size = (*buff -3)/4;
379 buff++;
380 if (*buff % 4 != 0) return(1);
381 opt->loose_route.pointer = *buff/4 - 1;
382 buff++;
383 buff++;
384 for (i = 0; i < opt->loose_route.route_size; i++) {
385 if(i>=MAX_ROUTE)
386 return(1);
387 opt->loose_route.route[i] = *(unsigned long *)buff;
388 buff += 4;
389 }
390 break;
391 case IPOPT_SSRR:
392 buff++;
393 if ((*buff - 3)% 4 != 0) return(1);
394 len += *buff;
395 opt->strict_route.route_size = (*buff -3)/4;
396 buff++;
397 if (*buff % 4 != 0) return(1);
398 opt->strict_route.pointer = *buff/4 - 1;
399 buff++;
400 buff++;
401 for (i = 0; i < opt->strict_route.route_size; i++) {
402 if(i>=MAX_ROUTE)
403 return(1);
404 opt->strict_route.route[i] = *(unsigned long *)buff;
405 buff += 4;
406 }
407 break;
408 case IPOPT_RR:
409 buff++;
410 if ((*buff - 3)% 4 != 0) return(1);
411 len += *buff;
412 opt->record_route.route_size = (*buff -3)/4;
413 buff++;
414 if (*buff % 4 != 0) return(1);
415 opt->record_route.pointer = *buff/4 - 1;
416 buff++;
417 buff++;
418 for (i = 0; i < opt->record_route.route_size; i++) {
419 if(i>=MAX_ROUTE)
420 return 1;
421 opt->record_route.route[i] = *(unsigned long *)buff;
422 buff += 4;
423 }
424 break;
425 case IPOPT_SID:
426 len += 4;
427 buff +=2;
428 opt->stream = *(unsigned short *)buff;
429 buff += 2;
430 break;
431 case IPOPT_TIMESTAMP:
432 buff++;
433 len += *buff;
434 if (*buff % 4 != 0) return(1);
435 opt->tstamp.len = *buff / 4 - 1;
436 buff++;
437 if ((*buff - 1) % 4 != 0) return(1);
438 opt->tstamp.ptr = (*buff-1)/4;
439 buff++;
440 opt->tstamp.x.full_char = *buff;
441 buff++;
442 for (i = 0; i < opt->tstamp.len; i++) {
443 opt->tstamp.data[i] = *(unsigned long *)buff;
444 buff += 4;
445 }
446 break;
447 default:
448 return(1);
449 }
450
451 if (opt->record_route.route_size == 0) {
452 if (opt->strict_route.route_size != 0) {
453 memcpy(&(opt->record_route), &(opt->strict_route),
454 sizeof(opt->record_route));
455 } else if (opt->loose_route.route_size != 0) {
456 memcpy(&(opt->record_route), &(opt->loose_route),
457 sizeof(opt->record_route));
458 }
459 }
460
461 if (opt->strict_route.route_size != 0 &&
462 opt->strict_route.route_size != opt->strict_route.pointer) {
463 strict_route(iph, opt);
464 return(0);
465 }
466
467 if (opt->loose_route.route_size != 0 &&
468 opt->loose_route.route_size != opt->loose_route.pointer) {
469 loose_route(iph, opt);
470 return(0);
471 }
472
473 return(0);
474 }
475
476 /*
477 * This is a version of ip_compute_csum() optimized for IP headers, which
478 * always checksum on 4 octet boundaries.
479 */
480
481 static inline unsigned short ip_fast_csum(unsigned char * buff, int wlen)
/* */
482 {
483 unsigned long sum = 0;
484
485 if (wlen)
486 {
487 unsigned long bogus;
488 __asm__("clc\n"
489 "1:\t"
490 "lodsl\n\t"
491 "adcl %3, %0\n\t"
492 "decl %2\n\t"
493 "jne 1b\n\t"
494 "adcl $0, %0\n\t"
495 "movl %0, %3\n\t"
496 "shrl $16, %3\n\t"
497 "addw %w3, %w0\n\t"
498 "adcw $0, %w0"
499 : "=r" (sum), "=S" (buff), "=r" (wlen), "=a" (bogus)
500 : "0" (sum), "1" (buff), "2" (wlen));
501 }
502 return (~sum) & 0xffff;
503 }
504
505 /*
506 * This routine does all the checksum computations that don't
507 * require anything special (like copying or special headers).
508 */
509
510 unsigned short ip_compute_csum(unsigned char * buff, int len)
/* */
511 {
512 unsigned long sum = 0;
513
514 /* Do the first multiple of 4 bytes and convert to 16 bits. */
515 if (len > 3)
516 {
517 __asm__("clc\n"
518 "1:\t"
519 "lodsl\n\t"
520 "adcl %%eax, %%ebx\n\t"
521 "loop 1b\n\t"
522 "adcl $0, %%ebx\n\t"
523 "movl %%ebx, %%eax\n\t"
524 "shrl $16, %%eax\n\t"
525 "addw %%ax, %%bx\n\t"
526 "adcw $0, %%bx"
527 : "=b" (sum) , "=S" (buff)
528 : "0" (sum), "c" (len >> 2) ,"1" (buff)
529 : "ax", "cx", "si", "bx" );
530 }
531 if (len & 2)
532 {
533 __asm__("lodsw\n\t"
534 "addw %%ax, %%bx\n\t"
535 "adcw $0, %%bx"
536 : "=b" (sum), "=S" (buff)
537 : "0" (sum), "1" (buff)
538 : "bx", "ax", "si");
539 }
540 if (len & 1)
541 {
542 __asm__("lodsb\n\t"
543 "movb $0, %%ah\n\t"
544 "addw %%ax, %%bx\n\t"
545 "adcw $0, %%bx"
546 : "=b" (sum), "=S" (buff)
547 : "0" (sum), "1" (buff)
548 : "bx", "ax", "si");
549 }
550 sum =~sum;
551 return(sum & 0xffff);
552 }
553
554 /*
555 * Check the header of an incoming IP datagram. This version is still used in slhc.c.
556 */
557
558 int ip_csum(struct iphdr *iph)
/* */
559 {
560 return ip_fast_csum((unsigned char *)iph, iph->ihl);
561 }
562
563 /*
564 * Generate a checksum for an outgoing IP datagram.
565 */
566
567 static void ip_send_check(struct iphdr *iph)
/* */
568 {
569 iph->check = 0;
570 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
571 }
572
573 /************************ Fragment Handlers From NET2E not yet with tweaks to beat 4K **********************************/
574
575
576 /*
577 * This fragment handler is a bit of a heap. On the other hand it works quite
578 * happily and handles things quite well.
579 */
580
581 static struct ipq *ipqueue = NULL; /* IP fragment queue */
582
583 /*
584 * Create a new fragment entry.
585 */
586
587 static struct ipfrag *ip_frag_create(int offset, int end, struct sk_buff *skb, unsigned char *ptr)
/* */
588 {
589 struct ipfrag *fp;
590
591 fp = (struct ipfrag *) kmalloc(sizeof(struct ipfrag), GFP_ATOMIC);
592 if (fp == NULL)
593 {
594 printk("IP: frag_create: no memory left !\n");
595 return(NULL);
596 }
597 memset(fp, 0, sizeof(struct ipfrag));
598
599 /* Fill in the structure. */
600 fp->offset = offset;
601 fp->end = end;
602 fp->len = end - offset;
603 fp->skb = skb;
604 fp->ptr = ptr;
605
606 return(fp);
607 }
608
609
610 /*
611 * Find the correct entry in the "incomplete datagrams" queue for
612 * this IP datagram, and return the queue entry address if found.
613 */
614
615 static struct ipq *ip_find(struct iphdr *iph)
/* */
616 {
617 struct ipq *qp;
618 struct ipq *qplast;
619
620 cli();
621 qplast = NULL;
622 for(qp = ipqueue; qp != NULL; qplast = qp, qp = qp->next)
623 {
624 if (iph->id== qp->iph->id && iph->saddr == qp->iph->saddr &&
625 iph->daddr == qp->iph->daddr && iph->protocol == qp->iph->protocol)
626 {
627 del_timer(&qp->timer); /* So it doesn't vanish on us. The timer will be reset anyway */
628 sti();
629 return(qp);
630 }
631 }
632 sti();
633 return(NULL);
634 }
635
636
637 /*
638 * Remove an entry from the "incomplete datagrams" queue, either
639 * because we completed, reassembled and processed it, or because
640 * it timed out.
641 */
642
643 static void ip_free(struct ipq *qp)
/* */
644 {
645 struct ipfrag *fp;
646 struct ipfrag *xp;
647
648 /*
649 * Stop the timer for this entry.
650 */
651
652 del_timer(&qp->timer);
653
654 /* Remove this entry from the "incomplete datagrams" queue. */
655 cli();
656 if (qp->prev == NULL)
657 {
658 ipqueue = qp->next;
659 if (ipqueue != NULL)
660 ipqueue->prev = NULL;
661 }
662 else
663 {
664 qp->prev->next = qp->next;
665 if (qp->next != NULL)
666 qp->next->prev = qp->prev;
667 }
668
669 /* Release all fragment data. */
670
671 fp = qp->fragments;
672 while (fp != NULL)
673 {
674 xp = fp->next;
675 IS_SKB(fp->skb);
676 kfree_skb(fp->skb,FREE_READ);
677 kfree_s(fp, sizeof(struct ipfrag));
678 fp = xp;
679 }
680
681 /* Release the MAC header. */
682 kfree_s(qp->mac, qp->maclen);
683
684 /* Release the IP header. */
685 kfree_s(qp->iph, qp->ihlen + 8);
686
687 /* Finally, release the queue descriptor itself. */
688 kfree_s(qp, sizeof(struct ipq));
689 sti();
690 }
691
692
693 /*
694 * Oops- a fragment queue timed out. Kill it and send an ICMP reply.
695 */
696
697 static void ip_expire(unsigned long arg)
/* */
698 {
699 struct ipq *qp;
700
701 qp = (struct ipq *)arg;
702
703 /*
704 * Send an ICMP "Fragment Reassembly Timeout" message.
705 */
706
707 ip_statistics.IpReasmTimeout++;
708 ip_statistics.IpReasmFails++;
709 /* This if is always true... shrug */
710 if(qp->fragments!=NULL)
711 icmp_send(qp->fragments->skb,ICMP_TIME_EXCEEDED,
712 ICMP_EXC_FRAGTIME, qp->dev);
713
714 /*
715 * Nuke the fragment queue.
716 */
717 ip_free(qp);
718 }
719
720
721 /*
722 * Add an entry to the 'ipq' queue for a newly received IP datagram.
723 * We will (hopefully :-) receive all other fragments of this datagram
724 * in time, so we just create a queue for this datagram, in which we
725 * will insert the received fragments at their respective positions.
726 */
727
728 static struct ipq *ip_create(struct sk_buff *skb, struct iphdr *iph, struct device *dev)
/* */
729 {
730 struct ipq *qp;
731 int maclen;
732 int ihlen;
733
734 qp = (struct ipq *) kmalloc(sizeof(struct ipq), GFP_ATOMIC);
735 if (qp == NULL)
736 {
737 printk("IP: create: no memory left !\n");
738 return(NULL);
739 skb->dev = qp->dev;
740 }
741 memset(qp, 0, sizeof(struct ipq));
742
743 /*
744 * Allocate memory for the MAC header.
745 *
746 * FIXME: We have a maximum MAC address size limit and define
747 * elsewhere. We should use it here and avoid the 3 kmalloc() calls
748 */
749
750 maclen = ((unsigned long) iph) - ((unsigned long) skb->data);
751 qp->mac = (unsigned char *) kmalloc(maclen, GFP_ATOMIC);
752 if (qp->mac == NULL)
753 {
754 printk("IP: create: no memory left !\n");
755 kfree_s(qp, sizeof(struct ipq));
756 return(NULL);
757 }
758
759 /*
760 * Allocate memory for the IP header (plus 8 octets for ICMP).
761 */
762
763 ihlen = (iph->ihl * sizeof(unsigned long));
764 qp->iph = (struct iphdr *) kmalloc(ihlen + 8, GFP_ATOMIC);
765 if (qp->iph == NULL)
766 {
767 printk("IP: create: no memory left !\n");
768 kfree_s(qp->mac, maclen);
769 kfree_s(qp, sizeof(struct ipq));
770 return(NULL);
771 }
772
773 /* Fill in the structure. */
774 memcpy(qp->mac, skb->data, maclen);
775 memcpy(qp->iph, iph, ihlen + 8);
776 qp->len = 0;
777 qp->ihlen = ihlen;
778 qp->maclen = maclen;
779 qp->fragments = NULL;
780 qp->dev = dev;
781
782 /* Start a timer for this entry. */
783 qp->timer.expires = IP_FRAG_TIME; /* about 30 seconds */
784 qp->timer.data = (unsigned long) qp; /* pointer to queue */
785 qp->timer.function = ip_expire; /* expire function */
786 add_timer(&qp->timer);
787
788 /* Add this entry to the queue. */
789 qp->prev = NULL;
790 cli();
791 qp->next = ipqueue;
792 if (qp->next != NULL)
793 qp->next->prev = qp;
794 ipqueue = qp;
795 sti();
796 return(qp);
797 }
798
799
800 /*
801 * See if a fragment queue is complete.
802 */
803
804 static int ip_done(struct ipq *qp)
/* */
805 {
806 struct ipfrag *fp;
807 int offset;
808
809 /* Only possible if we received the final fragment. */
810 if (qp->len == 0)
811 return(0);
812
813 /* Check all fragment offsets to see if they connect. */
814 fp = qp->fragments;
815 offset = 0;
816 while (fp != NULL)
817 {
818 if (fp->offset > offset)
819 return(0); /* fragment(s) missing */
820 offset = fp->end;
821 fp = fp->next;
822 }
823
824 /* All fragments are present. */
825 return(1);
826 }
827
828
829 /*
830 * Build a new IP datagram from all its fragments.
831 *
832 * FIXME: We copy here because we lack an effective way of handling lists
833 * of bits on input. Until the new skb data handling is in I'm not going
834 * to touch this with a bargepole. This also causes a 4Kish limit on
835 * packet sizes.
836 */
837
838 static struct sk_buff *ip_glue(struct ipq *qp)
/* */
839 {
840 struct sk_buff *skb;
841 struct iphdr *iph;
842 struct ipfrag *fp;
843 unsigned char *ptr;
844 int count, len;
845
846 /*
847 * Allocate a new buffer for the datagram.
848 */
849
850 len = qp->maclen + qp->ihlen + qp->len;
851
852 if ((skb = alloc_skb(len,GFP_ATOMIC)) == NULL)
853 {
854 ip_statistics.IpReasmFails++;
855 printk("IP: queue_glue: no memory for gluing queue 0x%X\n", (int) qp);
856 ip_free(qp);
857 return(NULL);
858 }
859
860 /* Fill in the basic details. */
861 skb->len = (len - qp->maclen);
862 skb->h.raw = skb->data;
863 skb->free = 1;
864
865 /* Copy the original MAC and IP headers into the new buffer. */
866 ptr = (unsigned char *) skb->h.raw;
867 memcpy(ptr, ((unsigned char *) qp->mac), qp->maclen);
868 ptr += qp->maclen;
869 memcpy(ptr, ((unsigned char *) qp->iph), qp->ihlen);
870 ptr += qp->ihlen;
871 skb->h.raw += qp->maclen;
872
873 count = 0;
874
875 /* Copy the data portions of all fragments into the new buffer. */
876 fp = qp->fragments;
877 while(fp != NULL)
878 {
879 if(count+fp->len > skb->len)
880 {
881 printk("Invalid fragment list: Fragment over size.\n");
882 ip_free(qp);
883 kfree_skb(skb,FREE_WRITE);
884 ip_statistics.IpReasmFails++;
885 return NULL;
886 }
887 memcpy((ptr + fp->offset), fp->ptr, fp->len);
888 count += fp->len;
889 fp = fp->next;
890 }
891
892 /* We glued together all fragments, so remove the queue entry. */
893 ip_free(qp);
894
895 /* Done with all fragments. Fixup the new IP header. */
896 iph = skb->h.iph;
897 iph->frag_off = 0;
898 iph->tot_len = htons((iph->ihl * sizeof(unsigned long)) + count);
899 skb->ip_hdr = iph;
900
901 ip_statistics.IpReasmOKs++;
902 return(skb);
903 }
904
905
906 /*
907 * Process an incoming IP datagram fragment.
908 */
909
910 static struct sk_buff *ip_defrag(struct iphdr *iph, struct sk_buff *skb, struct device *dev)
/* */
911 {
912 struct ipfrag *prev, *next;
913 struct ipfrag *tfp;
914 struct ipq *qp;
915 struct sk_buff *skb2;
916 unsigned char *ptr;
917 int flags, offset;
918 int i, ihl, end;
919
920 ip_statistics.IpReasmReqds++;
921
922 /* Find the entry of this IP datagram in the "incomplete datagrams" queue. */
923 qp = ip_find(iph);
924
925 /* Is this a non-fragmented datagram? */
926 offset = ntohs(iph->frag_off);
927 flags = offset & ~IP_OFFSET;
928 offset &= IP_OFFSET;
929 if (((flags & IP_MF) == 0) && (offset == 0))
930 {
931 if (qp != NULL)
932 ip_free(qp); /* Huh? How could this exist?? */
933 return(skb);
934 }
935
936 offset <<= 3; /* offset is in 8-byte chunks */
937
938 /*
939 * If the queue already existed, keep restarting its timer as long
940 * as we still are receiving fragments. Otherwise, create a fresh
941 * queue entry.
942 */
943
944 if (qp != NULL)
945 {
946 del_timer(&qp->timer);
947 qp->timer.expires = IP_FRAG_TIME; /* about 30 seconds */
948 qp->timer.data = (unsigned long) qp; /* pointer to queue */
949 qp->timer.function = ip_expire; /* expire function */
950 add_timer(&qp->timer);
951 }
952 else
953 {
954 /*
955 * If we failed to create it, then discard the frame
956 */
957 if ((qp = ip_create(skb, iph, dev)) == NULL)
958 {
959 skb->sk = NULL;
960 kfree_skb(skb, FREE_READ);
961 ip_statistics.IpReasmFails++;
962 return NULL;
963 }
964 }
965
966 /*
967 * Determine the position of this fragment.
968 */
969
970 ihl = (iph->ihl * sizeof(unsigned long));
971 end = offset + ntohs(iph->tot_len) - ihl;
972
973 /*
974 * Point into the IP datagram 'data' part.
975 */
976
977 ptr = skb->data + dev->hard_header_len + ihl;
978
979 /*
980 * Is this the final fragment?
981 */
982
983 if ((flags & IP_MF) == 0)
984 qp->len = end;
985
986 /*
987 * Find out which fragments are in front and at the back of us
988 * in the chain of fragments so far. We must know where to put
989 * this fragment, right?
990 */
991
992 prev = NULL;
993 for(next = qp->fragments; next != NULL; next = next->next)
994 {
995 if (next->offset > offset)
996 break; /* bingo! */
997 prev = next;
998 }
999
1000 /*
1001 * We found where to put this one.
1002 * Check for overlap with preceding fragment, and, if needed,
1003 * align things so that any overlaps are eliminated.
1004 */
1005 if (prev != NULL && offset < prev->end)
1006 {
1007 i = prev->end - offset;
1008 offset += i; /* ptr into datagram */
1009 ptr += i; /* ptr into fragment data */
1010 }
1011
1012 /*
1013 * Look for overlap with succeeding segments.
1014 * If we can merge fragments, do it.
1015 */
1016
1017 for(; next != NULL; next = tfp)
1018 {
1019 tfp = next->next;
1020 if (next->offset >= end)
1021 break; /* no overlaps at all */
1022
1023 i = end - next->offset; /* overlap is 'i' bytes */
1024 next->len -= i; /* so reduce size of */
1025 next->offset += i; /* next fragment */
1026 next->ptr += i;
1027
1028 /*
1029 * If we get a frag size of <= 0, remove it and the packet
1030 * that it goes with.
1031 */
1032 if (next->len <= 0)
1033 {
1034 if (next->prev != NULL)
1035 next->prev->next = next->next;
1036 else
1037 qp->fragments = next->next;
1038
1039 if (tfp->next != NULL)
1040 next->next->prev = next->prev;
1041
1042 kfree_skb(next->skb,FREE_READ);
1043 kfree_s(next, sizeof(struct ipfrag));
1044 }
1045 }
1046
1047 /*
1048 * Insert this fragment in the chain of fragments.
1049 */
1050
1051 tfp = NULL;
1052 tfp = ip_frag_create(offset, end, skb, ptr);
1053
1054 /*
1055 * No memory to save the fragment - so throw the lot
1056 */
1057
1058 if (!tfp)
1059 {
1060 skb->sk = NULL;
1061 kfree_skb(skb, FREE_READ);
1062 return NULL;
1063 }
1064 tfp->prev = prev;
1065 tfp->next = next;
1066 if (prev != NULL)
1067 prev->next = tfp;
1068 else
1069 qp->fragments = tfp;
1070
1071 if (next != NULL)
1072 next->prev = tfp;
1073
1074 /*
1075 * OK, so we inserted this new fragment into the chain.
1076 * Check if we now have a full IP datagram which we can
1077 * bump up to the IP layer...
1078 */
1079
1080 if (ip_done(qp))
1081 {
1082 skb2 = ip_glue(qp); /* glue together the fragments */
1083 return(skb2);
1084 }
1085 return(NULL);
1086 }
1087
1088
1089 /*
1090 * This IP datagram is too large to be sent in one piece. Break it up into
1091 * smaller pieces (each of size equal to the MAC header plus IP header plus
1092 * a block of the data of the original IP data part) that will yet fit in a
1093 * single device frame, and queue such a frame for sending by calling the
1094 * ip_queue_xmit(). Note that this is recursion, and bad things will happen
1095 * if this function causes a loop...
1096 *
1097 * Yes this is inefficient, feel free to submit a quicker one.
1098 *
1099 * **Protocol Violation**
1100 * We copy all the options to each fragment. !FIXME!
1101 */
1102 void ip_fragment(struct sock *sk, struct sk_buff *skb, struct device *dev, int is_frag)
/* */
1103 {
1104 struct iphdr *iph;
1105 unsigned char *raw;
1106 unsigned char *ptr;
1107 struct sk_buff *skb2;
1108 int left, mtu, hlen, len;
1109 int offset;
1110 unsigned long flags;
1111
1112 /*
1113 * Point into the IP datagram header.
1114 */
1115
1116 raw = skb->data;
1117 iph = (struct iphdr *) (raw + dev->hard_header_len);
1118
1119 skb->ip_hdr = iph;
1120
1121 /*
1122 * Setup starting values.
1123 */
1124
1125 hlen = (iph->ihl * sizeof(unsigned long));
1126 left = ntohs(iph->tot_len) - hlen; /* Space per frame */
1127 hlen += dev->hard_header_len; /* Total header size */
1128 mtu = (dev->mtu - hlen); /* Size of data space */
1129 ptr = (raw + hlen); /* Where to start from */
1130
1131 /*
1132 * Check for any "DF" flag. [DF means do not fragment]
1133 */
1134
1135 if (ntohs(iph->frag_off) & IP_DF)
1136 {
1137 ip_statistics.IpFragFails++;
1138 icmp_send(skb,ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, dev);
1139 return;
1140 }
1141
1142 /*
1143 * The protocol doesn't seem to say what to do in the case that the
1144 * frame + options doesn't fit the mtu. As it used to fall down dead
1145 * in this case we were fortunate it didn't happen
1146 */
1147
1148 if(mtu<8)
1149 {
1150 /* It's wrong but its better than nothing */
1151 icmp_send(skb,ICMP_DEST_UNREACH,ICMP_FRAG_NEEDED,dev);
1152 ip_statistics.IpFragFails++;
1153 return;
1154 }
1155
1156 /*
1157 * Fragment the datagram.
1158 */
1159
1160 /*
1161 * The initial offset is 0 for a complete frame. When
1162 * fragmenting fragments its wherever this one starts.
1163 */
1164
1165 if (is_frag & 2)
1166 offset = (ntohs(iph->frag_off) & 0x1fff) << 3;
1167 else
1168 offset = 0;
1169
1170
1171 /*
1172 * Keep copying data until we run out.
1173 */
1174
1175 while(left > 0)
1176 {
1177 len = left;
1178 /* IF: it doesn't fit, use 'mtu' - the data space left */
1179 if (len > mtu)
1180 len = mtu;
1181 /* IF: we are not sending upto and including the packet end
1182 then align the next start on an eight byte boundary */
1183 if (len < left)
1184 {
1185 len/=8;
1186 len*=8;
1187 }
1188 /*
1189 * Allocate buffer.
1190 */
1191
1192 if ((skb2 = alloc_skb(len + hlen,GFP_ATOMIC)) == NULL)
1193 {
1194 printk("IP: frag: no memory for new fragment!\n");
1195 ip_statistics.IpFragFails++;
1196 return;
1197 }
1198
1199 /*
1200 * Set up data on packet
1201 */
1202
1203 skb2->arp = skb->arp;
1204 if(skb->free==0)
1205 printk("IP fragmenter: BUG free!=1 in fragmenter\n");
1206 skb2->free = 1;
1207 skb2->len = len + hlen;
1208 skb2->h.raw=(char *) skb2->data;
1209 /*
1210 * Charge the memory for the fragment to any owner
1211 * it might possess
1212 */
1213
1214 save_flags(flags);
1215 if (sk)
1216 {
1217 cli();
1218 sk->wmem_alloc += skb2->mem_len;
1219 skb2->sk=sk;
1220 }
1221 restore_flags(flags);
1222 skb2->raddr = skb->raddr; /* For rebuild_header - must be here */
1223
1224 /*
1225 * Copy the packet header into the new buffer.
1226 */
1227
1228 memcpy(skb2->h.raw, raw, hlen);
1229
1230 /*
1231 * Copy a block of the IP datagram.
1232 */
1233 memcpy(skb2->h.raw + hlen, ptr, len);
1234 left -= len;
1235
1236 skb2->h.raw+=dev->hard_header_len;
1237
1238 /*
1239 * Fill in the new header fields.
1240 */
1241 iph = (struct iphdr *)(skb2->h.raw/*+dev->hard_header_len*/);
1242 iph->frag_off = htons((offset >> 3));
1243 /*
1244 * Added AC : If we are fragmenting a fragment thats not the
1245 * last fragment then keep MF on each bit
1246 */
1247 if (left > 0 || (is_frag & 1))
1248 iph->frag_off |= htons(IP_MF);
1249 ptr += len;
1250 offset += len;
1251
1252 /*
1253 * Put this fragment into the sending queue.
1254 */
1255
1256 ip_statistics.IpFragCreates++;
1257
1258 ip_queue_xmit(sk, dev, skb2, 2);
1259 }
1260 ip_statistics.IpFragOKs++;
1261 }
1262
1263
1264
1265 #ifdef CONFIG_IP_FORWARD
1266
1267 /*
1268 * Forward an IP datagram to its next destination.
1269 */
1270
1271 static void ip_forward(struct sk_buff *skb, struct device *dev, int is_frag)
/* */
1272 {
1273 struct device *dev2; /* Output device */
1274 struct iphdr *iph; /* Our header */
1275 struct sk_buff *skb2; /* Output packet */
1276 struct rtable *rt; /* Route we use */
1277 unsigned char *ptr; /* Data pointer */
1278 unsigned long raddr; /* Router IP address */
1279
1280 /*
1281 * See if we are allowed to forward this.
1282 */
1283
1284 #ifdef CONFIG_IP_FIREWALL
1285 if(!ip_fw_chk(skb->h.iph, ip_fw_fwd_chain))
1286 {
1287 return;
1288 }
1289 #endif
1290 /*
1291 * According to the RFC, we must first decrease the TTL field. If
1292 * that reaches zero, we must reply an ICMP control message telling
1293 * that the packet's lifetime expired.
1294 *
1295 * Exception:
1296 * We may not generate an ICMP for an ICMP. icmp_send does the
1297 * enforcement of this so we can forget it here. It is however
1298 * sometimes VERY important.
1299 */
1300
1301 iph = skb->h.iph;
1302 iph->ttl--;
1303 if (iph->ttl <= 0)
1304 {
1305 /* Tell the sender its packet died... */
1306 icmp_send(skb, ICMP_TIME_EXCEEDED, ICMP_EXC_TTL, dev);
1307 return;
1308 }
1309
1310 /*
1311 * Re-compute the IP header checksum.
1312 * This is inefficient. We know what has happened to the header
1313 * and could thus adjust the checksum as Phil Karn does in KA9Q
1314 */
1315
1316 ip_send_check(iph);
1317
1318 /*
1319 * OK, the packet is still valid. Fetch its destination address,
1320 * and give it to the IP sender for further processing.
1321 */
1322
1323 rt = ip_rt_route(iph->daddr, NULL, NULL);
1324 if (rt == NULL)
1325 {
1326 /*
1327 * Tell the sender its packet cannot be delivered. Again
1328 * ICMP is screened later.
1329 */
1330 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_NET_UNREACH, dev);
1331 return;
1332 }
1333
1334
1335 /*
1336 * Gosh. Not only is the packet valid; we even know how to
1337 * forward it onto its final destination. Can we say this
1338 * is being plain lucky?
1339 * If the router told us that there is no GW, use the dest.
1340 * IP address itself- we seem to be connected directly...
1341 */
1342
1343 raddr = rt->rt_gateway;
1344
1345 if (raddr != 0)
1346 {
1347 /*
1348 * There is a gateway so find the correct route for it.
1349 * Gateways cannot in turn be gatewayed.
1350 */
1351 rt = ip_rt_route(raddr, NULL, NULL);
1352 if (rt == NULL)
1353 {
1354 /*
1355 * Tell the sender its packet cannot be delivered...
1356 */
1357 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, dev);
1358 return;
1359 }
1360 if (rt->rt_gateway != 0)
1361 raddr = rt->rt_gateway;
1362 }
1363 else
1364 raddr = iph->daddr;
1365
1366 /*
1367 * Having picked a route we can now send the frame out.
1368 */
1369
1370 dev2 = rt->rt_dev;
1371
1372 /*
1373 * In IP you never forward a frame on the interface that it arrived
1374 * upon. We should generate an ICMP HOST REDIRECT giving the route
1375 * we calculated.
1376 * For now just dropping the packet is an acceptable compromise.
1377 */
1378
1379 if (dev == dev2)
1380 return;
1381
1382 /*
1383 * We now allocate a new buffer, and copy the datagram into it.
1384 * If the indicated interface is up and running, kick it.
1385 */
1386
1387 if (dev2->flags & IFF_UP)
1388 {
1389
1390 /*
1391 * Current design decrees we copy the packet. For identical header
1392 * lengths we could avoid it. The new skb code will let us push
1393 * data so the problem goes away then.
1394 */
1395
1396 skb2 = alloc_skb(dev2->hard_header_len + skb->len, GFP_ATOMIC);
1397 /*
1398 * This is rare and since IP is tolerant of network failures
1399 * quite harmless.
1400 */
1401 if (skb2 == NULL)
1402 {
1403 printk("\nIP: No memory available for IP forward\n");
1404 return;
1405 }
1406 ptr = skb2->data;
1407 skb2->free = 1;
1408 skb2->len = skb->len + dev2->hard_header_len;
1409 skb2->h.raw = ptr;
1410
1411 /*
1412 * Copy the packet data into the new buffer.
1413 */
1414 memcpy(ptr + dev2->hard_header_len, skb->h.raw, skb->len);
1415
1416 /* Now build the MAC header. */
1417 (void) ip_send(skb2, raddr, skb->len, dev2, dev2->pa_addr);
1418
1419 ip_statistics.IpForwDatagrams++;
1420
1421 /*
1422 * See if it needs fragmenting. Note in ip_rcv we tagged
1423 * the fragment type. This must be right so that
1424 * the fragmenter does the right thing.
1425 */
1426
1427 if(skb2->len > dev2->mtu + dev2->hard_header_len)
1428 {
1429 ip_fragment(NULL,skb2,dev2, is_frag);
1430 kfree_skb(skb2,FREE_WRITE);
1431 }
1432 else
1433 {
1434 #ifdef CONFIG_IP_ACCT
1435 /*
1436 * Count mapping we shortcut
1437 */
1438
1439 ip_acct_cnt(iph,ip_acct_chain,1);
1440 #endif
1441
1442 /*
1443 * Map service types to priority. We lie about
1444 * throughput being low priority, but its a good
1445 * choice to help improve general usage.
1446 */
1447 if(iph->tos & IPTOS_LOWDELAY)
1448 dev_queue_xmit(skb2, dev2, SOPRI_INTERACTIVE);
1449 else if(iph->tos & IPTOS_THROUGHPUT)
1450 dev_queue_xmit(skb2, dev2, SOPRI_BACKGROUND);
1451 else
1452 dev_queue_xmit(skb2, dev2, SOPRI_NORMAL);
1453 }
1454 }
1455 }
1456
1457
1458 #endif
1459
1460 /*
1461 * This function receives all incoming IP datagrams.
1462 */
1463
1464 int ip_rcv(struct sk_buff *skb, struct device *dev, struct packet_type *pt)
/* */
1465 {
1466 struct iphdr *iph = skb->h.iph;
1467 struct sock *raw_sk=NULL;
1468 unsigned char hash;
1469 unsigned char flag = 0;
1470 unsigned char opts_p = 0; /* Set iff the packet has options. */
1471 struct inet_protocol *ipprot;
1472 static struct options opt; /* since we don't use these yet, and they
1473 take up stack space. */
1474 int brd=IS_MYADDR;
1475 int is_frag=0;
1476
1477 ip_statistics.IpInReceives++;
1478
1479 /*
1480 * Tag the ip header of this packet so we can find it
1481 */
1482
1483 skb->ip_hdr = iph;
1484
1485 /*
1486 * Is the datagram acceptable?
1487 *
1488 * 1. Length at least the size of an ip header
1489 * 2. Version of 4
1490 * 3. Checksums correctly. [Speed optimisation for later, skip loopback checksums]
1491 * (4. We ought to check for IP multicast addresses and undefined types.. does this matter ?)
1492 */
1493
1494 if (skb->len<sizeof(struct iphdr) || iph->ihl<5 || iph->version != 4 || ip_fast_csum((unsigned char *)iph, iph->ihl) !=0)
1495 {
1496 ip_statistics.IpInHdrErrors++;
1497 kfree_skb(skb, FREE_WRITE);
1498 return(0);
1499 }
1500
1501 /*
1502 * See if the firewall wants to dispose of the packet.
1503 */
1504
1505 #ifdef CONFIG_IP_FIREWALL
1506
1507 if(!LOOPBACK(iph->daddr) && !ip_fw_chk(iph,ip_fw_blk_chain))
1508 {
1509 kfree_skb(skb, FREE_WRITE);
1510 return 0;
1511 }
1512
1513 #endif
1514
1515 /*
1516 * Our transport medium may have padded the buffer out. Now we know it
1517 * is IP we can trim to the true length of the frame.
1518 */
1519
1520 skb->len=ntohs(iph->tot_len);
1521
1522 /*
1523 * Next analyse the packet for options. Studies show under one packet in
1524 * a thousand have options....
1525 */
1526
1527 if (iph->ihl != 5)
1528 { /* Fast path for the typical optionless IP packet. */
1529 memset((char *) &opt, 0, sizeof(opt));
1530 if (do_options(iph, &opt) != 0)
1531 return 0;
1532 opts_p = 1;
1533 }
1534
1535 /*
1536 * Remember if the frame is fragmented.
1537 */
1538
1539 if(iph->frag_off)
1540 {
1541 if (iph->frag_off & 0x0020)
1542 is_frag|=1;
1543 /*
1544 * Last fragment ?
1545 */
1546
1547 if (ntohs(iph->frag_off) & 0x1fff)
1548 is_frag|=2;
1549 }
1550
1551 /*
1552 * Do any IP forwarding required. chk_addr() is expensive -- avoid it someday.
1553 *
1554 * This is inefficient. While finding out if it is for us we could also compute
1555 * the routing table entry. This is where the great unified cache theory comes
1556 * in as and when someone implements it
1557 *
1558 * For most hosts over 99% of packets match the first conditional
1559 * and don't go via ip_chk_addr. Note: brd is set to IS_MYADDR at
1560 * function entry.
1561 */
1562
1563 if ( iph->daddr != skb->dev->pa_addr && (brd = ip_chk_addr(iph->daddr)) == 0)
1564 {
1565 /*
1566 * Don't forward multicast or broadcast frames.
1567 */
1568
1569 if(skb->pkt_type!=PACKET_HOST || brd==IS_BROADCAST)
1570 {
1571 kfree_skb(skb,FREE_WRITE);
1572 return 0;
1573 }
1574
1575 /*
1576 * The packet is for another target. Forward the frame
1577 */
1578
1579 #ifdef CONFIG_IP_FORWARD
1580 ip_forward(skb, dev, is_frag);
1581 #else
1582 /* printk("Machine %lx tried to use us as a forwarder to %lx but we have forwarding disabled!\n",
1583 iph->saddr,iph->daddr);*/
1584 ip_statistics.IpInAddrErrors++;
1585 #endif
1586 /*
1587 * The forwarder is inefficient and copies the packet. We
1588 * free the original now.
1589 */
1590
1591 kfree_skb(skb, FREE_WRITE);
1592 return(0);
1593 }
1594
1595 /*
1596 * Account for the packet
1597 */
1598
1599 #ifdef CONFIG_IP_ACCT
1600 ip_acct_cnt(iph,ip_acct_chain,1);
1601 #endif
1602
1603 /*
1604 * Reassemble IP fragments.
1605 */
1606
1607 if(is_frag)
1608 {
1609 /* Defragment. Obtain the complete packet if there is one */
1610 skb=ip_defrag(iph,skb,dev);
1611 if(skb==NULL)
1612 return 0;
1613 skb->dev = dev;
1614 iph=skb->h.iph;
1615 }
1616
1617
1618
1619 /*
1620 * Point into the IP datagram, just past the header.
1621 */
1622
1623 skb->ip_hdr = iph;
1624 skb->h.raw += iph->ihl*4;
1625
1626 /*
1627 * Deliver to raw sockets. This is fun as to avoid copies we want to make no surplus copies.
1628 */
1629
1630 hash = iph->protocol & (SOCK_ARRAY_SIZE-1);
1631
1632 /* If there maybe a raw socket we must check - if not we don't care less */
1633 if((raw_sk=raw_prot.sock_array[hash])!=NULL)
1634 {
1635 struct sock *sknext=NULL;
1636 struct sk_buff *skb1;
1637 raw_sk=get_sock_raw(raw_sk, hash, iph->saddr, iph->daddr);
1638 if(raw_sk) /* Any raw sockets */
1639 {
1640 do
1641 {
1642 /* Find the next */
1643 sknext=get_sock_raw(raw_sk->next, hash, iph->saddr, iph->daddr);
1644 if(sknext)
1645 skb1=skb_clone(skb, GFP_ATOMIC);
1646 else
1647 break; /* One pending raw socket left */
1648 if(skb1)
1649 raw_rcv(raw_sk, skb1, dev, iph->saddr,iph->daddr);
1650 raw_sk=sknext;
1651 }
1652 while(raw_sk!=NULL);
1653 /* Here either raw_sk is the last raw socket, or NULL if none */
1654 /* We deliver to the last raw socket AFTER the protocol checks as it avoids a surplus copy */
1655 }
1656 }
1657
1658 /*
1659 * skb->h.raw now points at the protocol beyond the IP header.
1660 */
1661
1662 hash = iph->protocol & (MAX_INET_PROTOS -1);
1663 for (ipprot = (struct inet_protocol *)inet_protos[hash];ipprot != NULL;ipprot=(struct inet_protocol *)ipprot->next)
1664 {
1665 struct sk_buff *skb2;
1666
1667 if (ipprot->protocol != iph->protocol)
1668 continue;
1669 /*
1670 * See if we need to make a copy of it. This will
1671 * only be set if more than one protocol wants it.
1672 * and then not for the last one. If there is a pending
1673 * raw delivery wait for that
1674 */
1675 if (ipprot->copy || raw_sk)
1676 {
1677 skb2 = skb_clone(skb, GFP_ATOMIC);
1678 if(skb2==NULL)
1679 continue;
1680 }
1681 else
1682 {
1683 skb2 = skb;
1684 }
1685 flag = 1;
1686
1687 /*
1688 * Pass on the datagram to each protocol that wants it,
1689 * based on the datagram protocol. We should really
1690 * check the protocol handler's return values here...
1691 */
1692 ipprot->handler(skb2, dev, opts_p ? &opt : 0, iph->daddr,
1693 (ntohs(iph->tot_len) - (iph->ihl * 4)),
1694 iph->saddr, 0, ipprot);
1695
1696 }
1697
1698 /*
1699 * All protocols checked.
1700 * If this packet was a broadcast, we may *not* reply to it, since that
1701 * causes (proven, grin) ARP storms and a leakage of memory (i.e. all
1702 * ICMP reply messages get queued up for transmission...)
1703 */
1704
1705 if(raw_sk!=NULL) /* Shift to last raw user */
1706 raw_rcv(raw_sk, skb, dev, iph->saddr, iph->daddr);
1707 else if (!flag) /* Free and report errors */
1708 {
1709 if (brd != IS_BROADCAST && brd!=IS_MULTICAST)
1710 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PROT_UNREACH, dev);
1711 kfree_skb(skb, FREE_WRITE);
1712 }
1713
1714 return(0);
1715 }
1716
1717
1718 /*
1719 * Queues a packet to be sent, and starts the transmitter
1720 * if necessary. if free = 1 then we free the block after
1721 * transmit, otherwise we don't. If free==2 we not only
1722 * free the block but also don't assign a new ip seq number.
1723 * This routine also needs to put in the total length,
1724 * and compute the checksum
1725 */
1726
1727 void ip_queue_xmit(struct sock *sk, struct device *dev,
/* */
1728 struct sk_buff *skb, int free)
1729 {
1730 struct iphdr *iph;
1731 unsigned char *ptr;
1732
1733 /* Sanity check */
1734 if (dev == NULL)
1735 {
1736 printk("IP: ip_queue_xmit dev = NULL\n");
1737 return;
1738 }
1739
1740 IS_SKB(skb);
1741
1742 /*
1743 * Do some book-keeping in the packet for later
1744 */
1745
1746
1747 skb->dev = dev;
1748 skb->when = jiffies;
1749
1750 /*
1751 * Find the IP header and set the length. This is bad
1752 * but once we get the skb data handling code in the
1753 * hardware will push its header sensibly and we will
1754 * set skb->ip_hdr to avoid this mess and the fixed
1755 * header length problem
1756 */
1757
1758 ptr = skb->data;
1759 ptr += dev->hard_header_len;
1760 iph = (struct iphdr *)ptr;
1761 skb->ip_hdr = iph;
1762 iph->tot_len = ntohs(skb->len-dev->hard_header_len);
1763
1764 /*
1765 * No reassigning numbers to fragments...
1766 */
1767
1768 if(free!=2)
1769 iph->id = htons(ip_id_count++);
1770 else
1771 free=1;
1772
1773 /* All buffers without an owner socket get freed */
1774 if (sk == NULL)
1775 free = 1;
1776
1777 skb->free = free;
1778
1779 /*
1780 * Do we need to fragment. Again this is inefficient.
1781 * We need to somehow lock the original buffer and use
1782 * bits of it.
1783 */
1784
1785 if(skb->len > dev->mtu + dev->hard_header_len)
1786 {
1787 ip_fragment(sk,skb,dev,0);
1788 IS_SKB(skb);
1789 kfree_skb(skb,FREE_WRITE);
1790 return;
1791 }
1792
1793 /*
1794 * Add an IP checksum
1795 */
1796
1797 ip_send_check(iph);
1798
1799 /*
1800 * Print the frame when debugging
1801 */
1802
1803 /*
1804 * More debugging. You cannot queue a packet already on a list
1805 * Spot this and moan loudly.
1806 */
1807 if (skb->next != NULL)
1808 {
1809 printk("ip_queue_xmit: next != NULL\n");
1810 skb_unlink(skb);
1811 }
1812
1813 /*
1814 * If a sender wishes the packet to remain unfreed
1815 * we add it to his send queue. This arguably belongs
1816 * in the TCP level since nobody else uses it. BUT
1817 * remember IPng might change all the rules.
1818 */
1819
1820 if (!free)
1821 {
1822 unsigned long flags;
1823 /* The socket now has more outstanding blocks */
1824
1825 sk->packets_out++;
1826
1827 /* Protect the list for a moment */
1828 save_flags(flags);
1829 cli();
1830
1831 if (skb->link3 != NULL)
1832 {
1833 printk("ip.c: link3 != NULL\n");
1834 skb->link3 = NULL;
1835 }
1836 if (sk->send_head == NULL)
1837 {
1838 sk->send_tail = skb;
1839 sk->send_head = skb;
1840 }
1841 else
1842 {
1843 sk->send_tail->link3 = skb;
1844 sk->send_tail = skb;
1845 }
1846 /* skb->link3 is NULL */
1847
1848 /* Interrupt restore */
1849 restore_flags(flags);
1850 /* Set the IP write timeout to the round trip time for the packet.
1851 If an acknowledge has not arrived by then we may wish to act */
1852 reset_timer(sk, TIME_WRITE, sk->rto);
1853 }
1854 else
1855 /* Remember who owns the buffer */
1856 skb->sk = sk;
1857
1858 /*
1859 * If the indicated interface is up and running, send the packet.
1860 */
1861 ip_statistics.IpOutRequests++;
1862 #ifdef CONFIG_IP_ACCT
1863 ip_acct_cnt(iph,ip_acct_chain,1);
1864 #endif
1865
1866 if (dev->flags & IFF_UP)
1867 {
1868 /*
1869 * If we have an owner use its priority setting,
1870 * otherwise use NORMAL
1871 */
1872
1873 if (sk != NULL)
1874 {
1875 dev_queue_xmit(skb, dev, sk->priority);
1876 }
1877 else
1878 {
1879 dev_queue_xmit(skb, dev, SOPRI_NORMAL);
1880 }
1881 }
1882 else
1883 {
1884 ip_statistics.IpOutDiscards++;
1885 if (free)
1886 kfree_skb(skb, FREE_WRITE);
1887 }
1888 }
1889
1890
1891 /*
1892 * A socket has timed out on its send queue and wants to do a
1893 * little retransmitting. Currently this means TCP.
1894 */
1895
1896 void ip_do_retransmit(struct sock *sk, int all)
/* */
1897 {
1898 struct sk_buff * skb;
1899 struct proto *prot;
1900 struct device *dev;
1901
1902 prot = sk->prot;
1903 skb = sk->send_head;
1904
1905 while (skb != NULL)
1906 {
1907 dev = skb->dev;
1908 IS_SKB(skb);
1909 skb->when = jiffies;
1910
1911 /*
1912 * In general it's OK just to use the old packet. However we
1913 * need to use the current ack and window fields. Urg and
1914 * urg_ptr could possibly stand to be updated as well, but we
1915 * don't keep the necessary data. That shouldn't be a problem,
1916 * if the other end is doing the right thing. Since we're
1917 * changing the packet, we have to issue a new IP identifier.
1918 */
1919
1920 /* this check may be unnecessary - retransmit only for TCP */
1921 if (sk->protocol == IPPROTO_TCP) {
1922 struct tcphdr *th;
1923 struct iphdr *iph;
1924 int size;
1925
1926 iph = (struct iphdr *)(skb->data + dev->hard_header_len);
1927 th = (struct tcphdr *)(((char *)iph) + (iph->ihl << 2));
1928 size = skb->len - (((unsigned char *) th) - skb->data);
1929
1930 iph->id = htons(ip_id_count++);
1931 ip_send_check(iph);
1932
1933 th->ack_seq = ntohl(sk->acked_seq);
1934 th->window = ntohs(tcp_select_window(sk));
1935 tcp_send_check(th, sk->saddr, sk->daddr, size, sk);
1936 }
1937
1938 /*
1939 * If the interface is (still) up and running, kick it.
1940 */
1941
1942 if (dev->flags & IFF_UP)
1943 {
1944 /*
1945 * If the packet is still being sent by the device/protocol
1946 * below then don't retransmit. This is both needed, and good -
1947 * especially with connected mode AX.25 where it stops resends
1948 * occurring of an as yet unsent anyway frame!
1949 * We still add up the counts as the round trip time wants
1950 * adjusting.
1951 */
1952 if (sk && !skb_device_locked(skb))
1953 {
1954 /* Remove it from any existing driver queue first! */
1955 skb_unlink(skb);
1956 /* Now queue it */
1957 ip_statistics.IpOutRequests++;
1958 dev_queue_xmit(skb, dev, sk->priority);
1959 }
1960 }
1961
1962 /*
1963 * Count retransmissions
1964 */
1965 sk->retransmits++;
1966 sk->prot->retransmits ++;
1967
1968 /*
1969 * Only one retransmit requested.
1970 */
1971 if (!all)
1972 break;
1973
1974 /*
1975 * This should cut it off before we send too many packets.
1976 */
1977 if (sk->retransmits >= sk->cong_window)
1978 break;
1979 skb = skb->link3;
1980 }
1981 }
1982
1983 /*
1984 * This is the normal code called for timeouts. It does the retransmission
1985 * and then does backoff. ip_do_retransmit is separated out because
1986 * tcp_ack needs to send stuff from the retransmit queue without
1987 * initiating a backoff.
1988 */
1989
1990 void ip_retransmit(struct sock *sk, int all)
/* */
1991 {
1992 ip_do_retransmit(sk, all);
1993
1994 /*
1995 * Increase the timeout each time we retransmit. Note that
1996 * we do not increase the rtt estimate. rto is initialized
1997 * from rtt, but increases here. Jacobson (SIGCOMM 88) suggests
1998 * that doubling rto each time is the least we can get away with.
1999 * In KA9Q, Karn uses this for the first few times, and then
2000 * goes to quadratic. netBSD doubles, but only goes up to *64,
2001 * and clamps at 1 to 64 sec afterwards. Note that 120 sec is
2002 * defined in the protocol as the maximum possible RTT. I guess
2003 * we'll have to use something other than TCP to talk to the
2004 * University of Mars.
2005 */
2006
2007 sk->retransmits++;
2008 sk->backoff++;
2009 sk->rto = min(sk->rto << 1, 120*HZ);
2010 reset_timer(sk, TIME_WRITE, sk->rto);
2011 }
2012
2013 #ifdef CONFIG_IP_MULTICAST
2014
2015 /*
2016 * Write an multicast group list table for the IGMP daemon to
2017 * read.
2018 */
2019
2020 int ip_mc_procinfo(char *buffer, char **start, off_t offset, int length)
/* */
2021 {
2022 off_t pos=0, begin=0;
2023 struct ip_mc_list *im;
2024 unsigned long flags;
2025 int len=0;
2026
2027
2028 len=sprintf(buffer,"Device : Multicast\n");
2029 save_flags(flags);
2030 cli();
2031
2032 im=ip_mc_head;
2033
2034 while(im!=NULL)
2035 {
2036 len+=sprintf(buffer+len,"%-10s: %08lX\n", im->interface->name, im->multiaddr);
2037 pos=begin+len;
2038 if(pos<offset)
2039 {
2040 len=0;
2041 begin=pos;
2042 }
2043 if(pos>offset+length)
2044 break;
2045 im=im->next;
2046 }
2047 restore_flags(flags);
2048 *start=buffer+(offset-begin);
2049 len-=(offset-begin);
2050 if(len>length)
2051 len=length;
2052 return len;
2053 }
2054
2055
2056 #endif
2057 /*
2058 * Socket option code for IP. This is the end of the line after any TCP,UDP etc options on
2059 * an IP socket.
2060 *
2061 * We implement IP_TOS (type of service), IP_TTL (time to live).
2062 *
2063 * Next release we will sort out IP_OPTIONS since for some people are kind of important.
2064 */
2065
2066 int ip_setsockopt(struct sock *sk, int level, int optname, char *optval, int optlen)
/* */
2067 {
2068 int val,err;
2069 #if defined(CONFIG_IP_FIREWALL) || defined(CONFIG_IP_ACCT)
2070 struct ip_fw tmp_fw;
2071 #endif
2072 if (optval == NULL)
2073 return(-EINVAL);
2074
2075 err=verify_area(VERIFY_READ, optval, sizeof(int));
2076 if(err)
2077 return err;
2078
2079 val = get_fs_long((unsigned long *)optval);
2080
2081 if(level!=SOL_IP)
2082 return -EOPNOTSUPP;
2083
2084 switch(optname)
2085 {
2086 case IP_TOS:
2087 if(val<0||val>255)
2088 return -EINVAL;
2089 sk->ip_tos=val;
2090 if(val==IPTOS_LOWDELAY)
2091 sk->priority=SOPRI_INTERACTIVE;
2092 if(val==IPTOS_THROUGHPUT)
2093 sk->priority=SOPRI_BACKGROUND;
2094 return 0;
2095 case IP_TTL:
2096 if(val<1||val>255)
2097 return -EINVAL;
2098 sk->ip_ttl=val;
2099 return 0;
2100 #ifdef CONFIG_IP_MULTICAST
2101 case IP_MULTICAST_TTL:
2102 {
2103 unsigned char ucval;
2104
2105 ucval=get_fs_byte((unsigned char *)optval);
2106 printk("MC TTL %d\n", ucval);
2107 if(ucval<1||ucval>255)
2108 return -EINVAL;
2109 sk->ip_mc_ttl=(int)ucval;
2110 return 0;
2111 }
2112
2113 case IP_MULTICAST_IF:
2114 {
2115 /* Not fully tested */
2116 struct in_addr addr;
2117 struct device *dev=NULL;
2118
2119 /*
2120 * Check the arguments are allowable
2121 */
2122
2123 err=verify_area(VERIFY_READ, optval, sizeof(addr));
2124 if(err)
2125 return err;
2126
2127 memcpy_fromfs(&addr,optval,sizeof(addr));
2128
2129 printk("MC bind %s\n", in_ntoa(addr.s_addr));
2130
2131 /*
2132 * What address has been requested
2133 */
2134
2135 if(addr.s_addr==INADDR_ANY) /* Default */
2136 {
2137 sk->ip_mc_name[0]=0;
2138 return 0;
2139 }
2140
2141 /*
2142 * Find the device
2143 */
2144
2145 for(dev = dev_base; dev; dev = dev->next)
2146 {
2147 if((dev->flags&IFF_UP)&&(dev->flags&IFF_MULTICAST)&&
2148 (dev->pa_addr==addr.s_addr))
2149 break;
2150 }
2151
2152 /*
2153 * Did we find one
2154 */
2155
2156 if(dev)
2157 {
2158 strcpy(sk->ip_mc_name,dev->name);
2159 return 0;
2160 }
2161 return -EADDRNOTAVAIL;
2162 }
2163
2164 case IP_ADD_MEMBERSHIP:
2165 {
2166
2167 /*
2168 * FIXME: Add/Del membership should have a semaphore protecting them from re-entry
2169 */
2170 struct ip_mreq mreq;
2171 static struct options optmem;
2172 unsigned long route_src;
2173 struct rtable *rt;
2174 struct ip_mc_list *l=NULL;
2175 struct device *dev=NULL;
2176 int ct=0;
2177
2178 /*
2179 * Check the arguments.
2180 */
2181
2182 err=verify_area(VERIFY_READ, optval, sizeof(mreq));
2183 if(err)
2184 return err;
2185
2186 memcpy_fromfs(&mreq,optval,sizeof(mreq));
2187
2188 /*
2189 * Get device for use later
2190 */
2191
2192 if(mreq.imr_interface.s_addr==INADDR_ANY)
2193 {
2194 /*
2195 * Not set so scan.
2196 */
2197 if((rt=ip_rt_route(mreq.imr_multiaddr.s_addr,&optmem, &route_src))!=NULL)
2198 {
2199 dev=rt->rt_dev;
2200 rt->rt_use--;
2201 }
2202 }
2203 else
2204 {
2205 /*
2206 * Find a suitable device.
2207 */
2208 for(dev = dev_base; dev; dev = dev->next)
2209 {
2210 if((dev->flags&IFF_UP)&&(dev->flags&IFF_MULTICAST)&&
2211 (dev->pa_addr==mreq.imr_interface.s_addr))
2212 break;
2213 }
2214 }
2215
2216 /*
2217 * No device, no cookies.
2218 */
2219
2220 if(!dev)
2221 return -ENODEV;
2222
2223 /*
2224 * Join group.
2225 */
2226
2227 return ip_mc_join_group(sk,dev,mreq.imr_multiaddr.s_addr);
2228 }
2229
2230 case IP_DROP_MEMBERSHIP:
2231 {
2232 struct ip_mreq mreq;
2233 struct rtable *rt;
2234 static struct options optmem;
2235 unsigned long route_src;
2236 struct device *dev=NULL;
2237
2238 /*
2239 * Check the arguments
2240 */
2241
2242 err=verify_area(VERIFY_READ, optval, sizeof(mreq));
2243 if(err)
2244 return err;
2245
2246 memcpy_fromfs(&mreq,optval,sizeof(mreq));
2247
2248 /*
2249 * Get device for use later
2250 */
2251
2252 if(mreq.imr_interface.s_addr==INADDR_ANY)
2253 {
2254 if((rt=ip_rt_route(mreq.imr_multiaddr.s_addr,&optmem, &route_src))!=NULL)
2255 {
2256 dev=rt->rt_dev;
2257 rt->rt_use--;
2258 }
2259 }
2260 else
2261 {
2262 for(dev = dev_base; dev; dev = dev->next)
2263 {
2264 if((dev->flags&IFF_UP)&& (dev->flags&IFF_MULTICAST)&&
2265 (dev->pa_addr==mreq.imr_interface.s_addr))
2266 break;
2267 }
2268 }
2269
2270 /*
2271 * Did we find a suitable device.
2272 */
2273
2274 if(!dev)
2275 return -ENODEV;
2276
2277 /*
2278 * Leave group
2279 */
2280
2281 return ip_mc_leave_group(sk,dev,mreq.imr_multiaddr.s_addr);
2282 }
2283 #endif
2284 #ifdef CONFIG_IP_FIREWALL
2285 case IP_FW_ADD_BLK:
2286 case IP_FW_DEL_BLK:
2287 case IP_FW_ADD_FWD:
2288 case IP_FW_DEL_FWD:
2289 case IP_FW_CHK_BLK:
2290 case IP_FW_CHK_FWD:
2291 case IP_FW_FLUSH:
2292 case IP_FW_POLICY:
2293 if(!suser())
2294 return -EPERM;
2295 if(optlen>sizeof(tmp_fw) || optlen<1)
2296 return -EINVAL;
2297 err=verify_area(VERIFY_READ,optval,optlen);
2298 if(err)
2299 return err;
2300 memcpy_fromfs(&tmp_fw,optval,optlen);
2301 err=ip_fw_ctl(optname, &tmp_fw,optlen);
2302 return -err; /* -0 is 0 after all */
2303
2304 #endif
2305 #ifdef CONFIG_IP_ACCT
2306 case IP_ACCT_DEL:
2307 case IP_ACCT_ADD:
2308 case IP_ACCT_FLUSH:
2309 case IP_ACCT_ZERO:
2310 if(!suser())
2311 return -EPERM;
2312 if(optlen>sizeof(tmp_fw) || optlen<1)
2313 return -EINVAL;
2314 err=verify_area(VERIFY_READ,optval,optlen);
2315 if(err)
2316 return err;
2317 memcpy_fromfs(&tmp_fw, optval,optlen);
2318 err=ip_acct_ctl(optname, &tmp_fw,optlen);
2319 return -err; /* -0 is 0 after all */
2320 #endif
2321 /* IP_OPTIONS and friends go here eventually */
2322 default:
2323 return(-ENOPROTOOPT);
2324 }
2325 }
2326
2327 /*
2328 * Get the options. Note for future reference. The GET of IP options gets the
2329 * _received_ ones. The set sets the _sent_ ones.
2330 */
2331
2332 int ip_getsockopt(struct sock *sk, int level, int optname, char *optval, int *optlen)
/* */
2333 {
2334 int val,err;
2335 #ifdef CONFIG_IP_MULTICAST
2336 int len;
2337 #endif
2338
2339 if(level!=SOL_IP)
2340 return -EOPNOTSUPP;
2341
2342 switch(optname)
2343 {
2344 case IP_TOS:
2345 val=sk->ip_tos;
2346 break;
2347 case IP_TTL:
2348 val=sk->ip_ttl;
2349 break;
2350 #ifdef CONFIG_IP_MULTICAST
2351 case IP_MULTICAST_TTL:
2352 val=sk->ip_mc_ttl;
2353 break;
2354 case IP_MULTICAST_IF:
2355 err=verify_area(VERIFY_WRITE, optlen, sizeof(int));
2356 if(err)
2357 return err;
2358 len=strlen(sk->ip_mc_name);
2359 err=verify_area(VERIFY_WRITE, optval, len);
2360 if(err)
2361 return err;
2362 put_fs_long(len,(unsigned long *) optlen);
2363 memcpy_tofs((void *)optval,sk->ip_mc_name, len);
2364 return 0;
2365 #endif
2366 default:
2367 return(-ENOPROTOOPT);
2368 }
2369 err=verify_area(VERIFY_WRITE, optlen, sizeof(int));
2370 if(err)
2371 return err;
2372 put_fs_long(sizeof(int),(unsigned long *) optlen);
2373
2374 err=verify_area(VERIFY_WRITE, optval, sizeof(int));
2375 if(err)
2376 return err;
2377 put_fs_long(val,(unsigned long *)optval);
2378
2379 return(0);
2380 }
2381
2382 /*
2383 * IP protocol layer initialiser
2384 */
2385
2386 static struct packet_type ip_packet_type =
2387 {
2388 0, /* MUTTER ntohs(ETH_P_IP),*/
2389 0, /* copy */
2390 ip_rcv,
2391 NULL,
2392 NULL,
2393 };
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 /* ip_raw_init();
2405 ip_packet_init();
2406 ip_tcp_init();
2407 ip_udp_init();*/
2408 }
![[bottom]](../icons/n_bottom.png){kind=icon}
*/