![[first]](../icons/first.png){kind=icon}
![[previous]](../icons/n_left.png){kind=icon}
![[next]](../icons/n_right.png){kind=icon}
![[last]](../icons/last.png){kind=icon}
![[top]](../icons/n_top.png){kind=icon}
![[bottom]](../icons/bottom.png){kind=icon}
![[index]](../icons/index.png){kind=icon}
![[help]](../icons/help.png){kind=icon}
*/
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 * Gunther Mayer : Fix the SNMP reporting typo
62 * Alan Cox : Always in group 224.0.0.1
63 * Alan Cox : Multicast loopback error for 224.0.0.1
64 * Alan Cox : IP_MULTICAST_LOOP option.
65 * Alan Cox : Use notifiers.
66 *
67 * To Fix:
68 * IP option processing is mostly not needed. ip_forward needs to know about routing rules
69 * and time stamp but that's about all. Use the route mtu field here too
70 * IP fragmentation wants rewriting cleanly. The RFC815 algorithm is much more efficient
71 * and could be made very efficient with the addition of some virtual memory hacks to permit
72 * the allocation of a buffer that can then be 'grown' by twiddling page tables.
73 * Output fragmentation wants updating along with the buffer management to use a single
74 * interleaved copy algorithm so that fragmenting has a one copy overhead. Actual packet
75 * output should probably do its own fragmentation at the UDP/RAW layer. TCP shouldn't cause
76 * fragmentation anyway.
77 *
78 * This program is free software; you can redistribute it and/or
79 * modify it under the terms of the GNU General Public License
80 * as published by the Free Software Foundation; either version
81 * 2 of the License, or (at your option) any later version.
82 */
83
84 #include <asm/segment.h>
85 #include <asm/system.h>
86 #include <linux/types.h>
87 #include <linux/kernel.h>
88 #include <linux/sched.h>
89 #include <linux/string.h>
90 #include <linux/errno.h>
91 #include <linux/config.h>
92
93 #include <linux/socket.h>
94 #include <linux/sockios.h>
95 #include <linux/in.h>
96 #include <linux/inet.h>
97 #include <linux/netdevice.h>
98 #include <linux/etherdevice.h>
99
100 #include "snmp.h"
101 #include "ip.h"
102 #include "protocol.h"
103 #include "route.h"
104 #include "tcp.h"
105 #include <linux/skbuff.h>
106 #include "sock.h"
107 #include "arp.h"
108 #include "icmp.h"
109 #include "raw.h"
110 #include "igmp.h"
111 #include <linux/ip_fw.h>
112
113 #define CONFIG_IP_DEFRAG
114
115 extern int last_retran;
116 extern void sort_send(struct sock *sk);
117
118 #define min(a,b) ((a)<(b)?(a):(b))
119 #define LOOPBACK(x) (((x) & htonl(0xff000000)) == htonl(0x7f000000))
120
121 /*
122 * SNMP management statistics
123 */
124
125 #ifdef CONFIG_IP_FORWARD
126 struct ip_mib ip_statistics={1,64,}; /* Forwarding=Yes, Default TTL=64 */
127 #else
128 struct ip_mib ip_statistics={0,64,}; /* Forwarding=No, Default TTL=64 */
129 #endif
130
131 #ifdef CONFIG_IP_MULTICAST
132
133 struct ip_mc_list *ip_mc_head=NULL;
134
135 #endif
136
137 /*
138 * Handle the issuing of an ioctl() request
139 * for the ip device. This is scheduled to
140 * disappear
141 */
142
143 int ip_ioctl(struct sock *sk, int cmd, unsigned long arg)
/* ![[next]](../icons/right.png)
![[first]](../icons/n_first.png)
![[top]](../icons/top.png)
*/
144 {
145 switch(cmd)
146 {
147 default:
148 return(-EINVAL);
149 }
150 }
151
152
153 /* these two routines will do routing. */
154
155 static void
156 strict_route(struct iphdr *iph, struct options *opt)
/* ![[previous]](../icons/left.png)
*/
157 {
158 }
159
160
161 static void
162 loose_route(struct iphdr *iph, struct options *opt)
/* */
163 {
164 }
165
166
167
168
169 /* This routine will check to see if we have lost a gateway. */
170 void
171 ip_route_check(unsigned long daddr)
/* */
172 {
173 }
174
175
176 #if 0
177 /* this routine puts the options at the end of an ip header. */
178 static int
179 build_options(struct iphdr *iph, struct options *opt)
/* */
180 {
181 unsigned char *ptr;
182 /* currently we don't support any options. */
183 ptr = (unsigned char *)(iph+1);
184 *ptr = 0;
185 return (4);
186 }
187 #endif
188
189
190 /*
191 * Take an skb, and fill in the MAC header.
192 */
193
194 static int ip_send(struct sk_buff *skb, unsigned long daddr, int len, struct device *dev, unsigned long saddr)
/* */
195 {
196 int mac = 0;
197
198 skb->dev = dev;
199 skb->arp = 1;
200 if (dev->hard_header)
201 {
202 /*
203 * Build a hardware header. Source address is our mac, destination unknown
204 * (rebuild header will sort this out)
205 */
206 mac = dev->hard_header(skb->data, dev, ETH_P_IP, NULL, NULL, len, skb);
207 if (mac < 0)
208 {
209 mac = -mac;
210 skb->arp = 0;
211 skb->raddr = daddr; /* next routing address */
212 }
213 }
214 return mac;
215 }
216
217 int ip_id_count = 0;
218
219 /*
220 * This routine builds the appropriate hardware/IP headers for
221 * the routine. It assumes that if *dev != NULL then the
222 * protocol knows what it's doing, otherwise it uses the
223 * routing/ARP tables to select a device struct.
224 */
225 int ip_build_header(struct sk_buff *skb, unsigned long saddr, unsigned long daddr,
/* */
226 struct device **dev, int type, struct options *opt, int len, int tos, int ttl)
227 {
228 static struct options optmem;
229 struct iphdr *iph;
230 struct rtable *rt;
231 unsigned char *buff;
232 unsigned long raddr;
233 int tmp;
234 unsigned long src;
235
236 buff = skb->data;
237
238 /*
239 * See if we need to look up the device.
240 */
241
242 #ifdef CONFIG_INET_MULTICAST
243 if(MULTICAST(daddr) && *dev==NULL && skb->sk && *skb->sk->ip_mc_name)
244 *dev=dev_get(skb->sk->ip_mc_name);
245 #endif
246 if (*dev == NULL)
247 {
248 if(skb->localroute)
249 rt = ip_rt_local(daddr, &optmem, &src);
250 else
251 rt = ip_rt_route(daddr, &optmem, &src);
252 if (rt == NULL)
253 {
254 ip_statistics.IpOutNoRoutes++;
255 return(-ENETUNREACH);
256 }
257
258 *dev = rt->rt_dev;
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 raddr = rt->rt_gateway;
266
267 opt = &optmem;
268 }
269 else
270 {
271 /*
272 * We still need the address of the first hop.
273 */
274 if(skb->localroute)
275 rt = ip_rt_local(daddr, &optmem, &src);
276 else
277 rt = ip_rt_route(daddr, &optmem, &src);
278 /*
279 * If the frame is from us and going off machine it MUST MUST MUST
280 * have the output device ip address and never the loopback
281 */
282 if (LOOPBACK(saddr) && !LOOPBACK(daddr))
283 saddr = src;/*rt->rt_dev->pa_addr;*/
284
285 raddr = (rt == NULL) ? 0 : rt->rt_gateway;
286 }
287
288 /*
289 * No source addr so make it our addr
290 */
291 if (saddr == 0)
292 saddr = src;
293
294 /*
295 * No gateway so aim at the real destination
296 */
297 if (raddr == 0)
298 raddr = daddr;
299
300 /*
301 * Now build the MAC header.
302 */
303
304 tmp = ip_send(skb, raddr, len, *dev, saddr);
305 buff += tmp;
306 len -= tmp;
307
308 /*
309 * Book keeping
310 */
311
312 skb->dev = *dev;
313 skb->saddr = saddr;
314 if (skb->sk)
315 skb->sk->saddr = saddr;
316
317 /*
318 * Now build the IP header.
319 */
320
321 /*
322 * If we are using IPPROTO_RAW, then we don't need an IP header, since
323 * one is being supplied to us by the user
324 */
325
326 if(type == IPPROTO_RAW)
327 return (tmp);
328
329 iph = (struct iphdr *)buff;
330 iph->version = 4;
331 iph->tos = tos;
332 iph->frag_off = 0;
333 iph->ttl = ttl;
334 iph->daddr = daddr;
335 iph->saddr = saddr;
336 iph->protocol = type;
337 iph->ihl = 5;
338 skb->ip_hdr = iph;
339
340 /* Setup the IP options. */
341 #ifdef Not_Yet_Avail
342 build_options(iph, opt);
343 #endif
344 #ifdef CONFIG_IP_FIREWALL
345 if(!ip_fw_chk(iph,ip_fw_blk_chain))
346 return -EPERM;
347 #endif
348
349 return(20 + tmp); /* IP header plus MAC header size */
350 }
351
352
353 static int
354 do_options(struct iphdr *iph, struct options *opt)
/* */
355 {
356 unsigned char *buff;
357 int done = 0;
358 int i, len = sizeof(struct iphdr);
359
360 /* Zero out the options. */
361 opt->record_route.route_size = 0;
362 opt->loose_route.route_size = 0;
363 opt->strict_route.route_size = 0;
364 opt->tstamp.ptr = 0;
365 opt->security = 0;
366 opt->compartment = 0;
367 opt->handling = 0;
368 opt->stream = 0;
369 opt->tcc = 0;
370 return(0);
371
372 /* Advance the pointer to start at the options. */
373 buff = (unsigned char *)(iph + 1);
374
375 /* Now start the processing. */
376 while (!done && len < iph->ihl*4) switch(*buff) {
377 case IPOPT_END:
378 done = 1;
379 break;
380 case IPOPT_NOOP:
381 buff++;
382 len++;
383 break;
384 case IPOPT_SEC:
385 buff++;
386 if (*buff != 11) return(1);
387 buff++;
388 opt->security = ntohs(*(unsigned short *)buff);
389 buff += 2;
390 opt->compartment = ntohs(*(unsigned short *)buff);
391 buff += 2;
392 opt->handling = ntohs(*(unsigned short *)buff);
393 buff += 2;
394 opt->tcc = ((*buff) << 16) + ntohs(*(unsigned short *)(buff+1));
395 buff += 3;
396 len += 11;
397 break;
398 case IPOPT_LSRR:
399 buff++;
400 if ((*buff - 3)% 4 != 0) return(1);
401 len += *buff;
402 opt->loose_route.route_size = (*buff -3)/4;
403 buff++;
404 if (*buff % 4 != 0) return(1);
405 opt->loose_route.pointer = *buff/4 - 1;
406 buff++;
407 buff++;
408 for (i = 0; i < opt->loose_route.route_size; i++) {
409 if(i>=MAX_ROUTE)
410 return(1);
411 opt->loose_route.route[i] = *(unsigned long *)buff;
412 buff += 4;
413 }
414 break;
415 case IPOPT_SSRR:
416 buff++;
417 if ((*buff - 3)% 4 != 0) return(1);
418 len += *buff;
419 opt->strict_route.route_size = (*buff -3)/4;
420 buff++;
421 if (*buff % 4 != 0) return(1);
422 opt->strict_route.pointer = *buff/4 - 1;
423 buff++;
424 buff++;
425 for (i = 0; i < opt->strict_route.route_size; i++) {
426 if(i>=MAX_ROUTE)
427 return(1);
428 opt->strict_route.route[i] = *(unsigned long *)buff;
429 buff += 4;
430 }
431 break;
432 case IPOPT_RR:
433 buff++;
434 if ((*buff - 3)% 4 != 0) return(1);
435 len += *buff;
436 opt->record_route.route_size = (*buff -3)/4;
437 buff++;
438 if (*buff % 4 != 0) return(1);
439 opt->record_route.pointer = *buff/4 - 1;
440 buff++;
441 buff++;
442 for (i = 0; i < opt->record_route.route_size; i++) {
443 if(i>=MAX_ROUTE)
444 return 1;
445 opt->record_route.route[i] = *(unsigned long *)buff;
446 buff += 4;
447 }
448 break;
449 case IPOPT_SID:
450 len += 4;
451 buff +=2;
452 opt->stream = *(unsigned short *)buff;
453 buff += 2;
454 break;
455 case IPOPT_TIMESTAMP:
456 buff++;
457 len += *buff;
458 if (*buff % 4 != 0) return(1);
459 opt->tstamp.len = *buff / 4 - 1;
460 buff++;
461 if ((*buff - 1) % 4 != 0) return(1);
462 opt->tstamp.ptr = (*buff-1)/4;
463 buff++;
464 opt->tstamp.x.full_char = *buff;
465 buff++;
466 for (i = 0; i < opt->tstamp.len; i++) {
467 opt->tstamp.data[i] = *(unsigned long *)buff;
468 buff += 4;
469 }
470 break;
471 default:
472 return(1);
473 }
474
475 if (opt->record_route.route_size == 0) {
476 if (opt->strict_route.route_size != 0) {
477 memcpy(&(opt->record_route), &(opt->strict_route),
478 sizeof(opt->record_route));
479 } else if (opt->loose_route.route_size != 0) {
480 memcpy(&(opt->record_route), &(opt->loose_route),
481 sizeof(opt->record_route));
482 }
483 }
484
485 if (opt->strict_route.route_size != 0 &&
486 opt->strict_route.route_size != opt->strict_route.pointer) {
487 strict_route(iph, opt);
488 return(0);
489 }
490
491 if (opt->loose_route.route_size != 0 &&
492 opt->loose_route.route_size != opt->loose_route.pointer) {
493 loose_route(iph, opt);
494 return(0);
495 }
496
497 return(0);
498 }
499
500 /*
501 * This is a version of ip_compute_csum() optimized for IP headers, which
502 * always checksum on 4 octet boundaries.
503 */
504
505 static inline unsigned short ip_fast_csum(unsigned char * buff, int wlen)
/* */
506 {
507 unsigned long sum = 0;
508
509 if (wlen)
510 {
511 unsigned long bogus;
512 __asm__("clc\n"
513 "1:\t"
514 "lodsl\n\t"
515 "adcl %3, %0\n\t"
516 "decl %2\n\t"
517 "jne 1b\n\t"
518 "adcl $0, %0\n\t"
519 "movl %0, %3\n\t"
520 "shrl $16, %3\n\t"
521 "addw %w3, %w0\n\t"
522 "adcw $0, %w0"
523 : "=r" (sum), "=S" (buff), "=r" (wlen), "=a" (bogus)
524 : "0" (sum), "1" (buff), "2" (wlen));
525 }
526 return (~sum) & 0xffff;
527 }
528
529 /*
530 * This routine does all the checksum computations that don't
531 * require anything special (like copying or special headers).
532 */
533
534 unsigned short ip_compute_csum(unsigned char * buff, int len)
/* */
535 {
536 unsigned long sum = 0;
537
538 /* Do the first multiple of 4 bytes and convert to 16 bits. */
539 if (len > 3)
540 {
541 __asm__("clc\n"
542 "1:\t"
543 "lodsl\n\t"
544 "adcl %%eax, %%ebx\n\t"
545 "loop 1b\n\t"
546 "adcl $0, %%ebx\n\t"
547 "movl %%ebx, %%eax\n\t"
548 "shrl $16, %%eax\n\t"
549 "addw %%ax, %%bx\n\t"
550 "adcw $0, %%bx"
551 : "=b" (sum) , "=S" (buff)
552 : "0" (sum), "c" (len >> 2) ,"1" (buff)
553 : "ax", "cx", "si", "bx" );
554 }
555 if (len & 2)
556 {
557 __asm__("lodsw\n\t"
558 "addw %%ax, %%bx\n\t"
559 "adcw $0, %%bx"
560 : "=b" (sum), "=S" (buff)
561 : "0" (sum), "1" (buff)
562 : "bx", "ax", "si");
563 }
564 if (len & 1)
565 {
566 __asm__("lodsb\n\t"
567 "movb $0, %%ah\n\t"
568 "addw %%ax, %%bx\n\t"
569 "adcw $0, %%bx"
570 : "=b" (sum), "=S" (buff)
571 : "0" (sum), "1" (buff)
572 : "bx", "ax", "si");
573 }
574 sum =~sum;
575 return(sum & 0xffff);
576 }
577
578 /*
579 * Check the header of an incoming IP datagram. This version is still used in slhc.c.
580 */
581
582 int ip_csum(struct iphdr *iph)
/* */
583 {
584 return ip_fast_csum((unsigned char *)iph, iph->ihl);
585 }
586
587 /*
588 * Generate a checksum for an outgoing IP datagram.
589 */
590
591 void ip_send_check(struct iphdr *iph)
/* */
592 {
593 iph->check = 0;
594 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
595 }
596
597 /************************ Fragment Handlers From NET2E **********************************/
598
599
600 /*
601 * This fragment handler is a bit of a heap. On the other hand it works quite
602 * happily and handles things quite well.
603 */
604
605 static struct ipq *ipqueue = NULL; /* IP fragment queue */
606
607 /*
608 * Create a new fragment entry.
609 */
610
611 static struct ipfrag *ip_frag_create(int offset, int end, struct sk_buff *skb, unsigned char *ptr)
/* */
612 {
613 struct ipfrag *fp;
614
615 fp = (struct ipfrag *) kmalloc(sizeof(struct ipfrag), GFP_ATOMIC);
616 if (fp == NULL)
617 {
618 printk("IP: frag_create: no memory left !\n");
619 return(NULL);
620 }
621 memset(fp, 0, sizeof(struct ipfrag));
622
623 /* Fill in the structure. */
624 fp->offset = offset;
625 fp->end = end;
626 fp->len = end - offset;
627 fp->skb = skb;
628 fp->ptr = ptr;
629
630 return(fp);
631 }
632
633
634 /*
635 * Find the correct entry in the "incomplete datagrams" queue for
636 * this IP datagram, and return the queue entry address if found.
637 */
638
639 static struct ipq *ip_find(struct iphdr *iph)
/* */
640 {
641 struct ipq *qp;
642 struct ipq *qplast;
643
644 cli();
645 qplast = NULL;
646 for(qp = ipqueue; qp != NULL; qplast = qp, qp = qp->next)
647 {
648 if (iph->id== qp->iph->id && iph->saddr == qp->iph->saddr &&
649 iph->daddr == qp->iph->daddr && iph->protocol == qp->iph->protocol)
650 {
651 del_timer(&qp->timer); /* So it doesn't vanish on us. The timer will be reset anyway */
652 sti();
653 return(qp);
654 }
655 }
656 sti();
657 return(NULL);
658 }
659
660
661 /*
662 * Remove an entry from the "incomplete datagrams" queue, either
663 * because we completed, reassembled and processed it, or because
664 * it timed out.
665 */
666
667 static void ip_free(struct ipq *qp)
/* */
668 {
669 struct ipfrag *fp;
670 struct ipfrag *xp;
671
672 /*
673 * Stop the timer for this entry.
674 */
675
676 del_timer(&qp->timer);
677
678 /* Remove this entry from the "incomplete datagrams" queue. */
679 cli();
680 if (qp->prev == NULL)
681 {
682 ipqueue = qp->next;
683 if (ipqueue != NULL)
684 ipqueue->prev = NULL;
685 }
686 else
687 {
688 qp->prev->next = qp->next;
689 if (qp->next != NULL)
690 qp->next->prev = qp->prev;
691 }
692
693 /* Release all fragment data. */
694
695 fp = qp->fragments;
696 while (fp != NULL)
697 {
698 xp = fp->next;
699 IS_SKB(fp->skb);
700 kfree_skb(fp->skb,FREE_READ);
701 kfree_s(fp, sizeof(struct ipfrag));
702 fp = xp;
703 }
704
705 /* Release the MAC header. */
706 kfree_s(qp->mac, qp->maclen);
707
708 /* Release the IP header. */
709 kfree_s(qp->iph, qp->ihlen + 8);
710
711 /* Finally, release the queue descriptor itself. */
712 kfree_s(qp, sizeof(struct ipq));
713 sti();
714 }
715
716
717 /*
718 * Oops- a fragment queue timed out. Kill it and send an ICMP reply.
719 */
720
721 static void ip_expire(unsigned long arg)
/* */
722 {
723 struct ipq *qp;
724
725 qp = (struct ipq *)arg;
726
727 /*
728 * Send an ICMP "Fragment Reassembly Timeout" message.
729 */
730
731 ip_statistics.IpReasmTimeout++;
732 ip_statistics.IpReasmFails++;
733 /* This if is always true... shrug */
734 if(qp->fragments!=NULL)
735 icmp_send(qp->fragments->skb,ICMP_TIME_EXCEEDED,
736 ICMP_EXC_FRAGTIME, qp->dev);
737
738 /*
739 * Nuke the fragment queue.
740 */
741 ip_free(qp);
742 }
743
744
745 /*
746 * Add an entry to the 'ipq' queue for a newly received IP datagram.
747 * We will (hopefully :-) receive all other fragments of this datagram
748 * in time, so we just create a queue for this datagram, in which we
749 * will insert the received fragments at their respective positions.
750 */
751
752 static struct ipq *ip_create(struct sk_buff *skb, struct iphdr *iph, struct device *dev)
/* */
753 {
754 struct ipq *qp;
755 int maclen;
756 int ihlen;
757
758 qp = (struct ipq *) kmalloc(sizeof(struct ipq), GFP_ATOMIC);
759 if (qp == NULL)
760 {
761 printk("IP: create: no memory left !\n");
762 return(NULL);
763 skb->dev = qp->dev;
764 }
765 memset(qp, 0, sizeof(struct ipq));
766
767 /*
768 * Allocate memory for the MAC header.
769 *
770 * FIXME: We have a maximum MAC address size limit and define
771 * elsewhere. We should use it here and avoid the 3 kmalloc() calls
772 */
773
774 maclen = ((unsigned long) iph) - ((unsigned long) skb->data);
775 qp->mac = (unsigned char *) kmalloc(maclen, GFP_ATOMIC);
776 if (qp->mac == NULL)
777 {
778 printk("IP: create: no memory left !\n");
779 kfree_s(qp, sizeof(struct ipq));
780 return(NULL);
781 }
782
783 /*
784 * Allocate memory for the IP header (plus 8 octets for ICMP).
785 */
786
787 ihlen = (iph->ihl * sizeof(unsigned long));
788 qp->iph = (struct iphdr *) kmalloc(ihlen + 8, GFP_ATOMIC);
789 if (qp->iph == NULL)
790 {
791 printk("IP: create: no memory left !\n");
792 kfree_s(qp->mac, maclen);
793 kfree_s(qp, sizeof(struct ipq));
794 return(NULL);
795 }
796
797 /* Fill in the structure. */
798 memcpy(qp->mac, skb->data, maclen);
799 memcpy(qp->iph, iph, ihlen + 8);
800 qp->len = 0;
801 qp->ihlen = ihlen;
802 qp->maclen = maclen;
803 qp->fragments = NULL;
804 qp->dev = dev;
805
806 /* Start a timer for this entry. */
807 qp->timer.expires = IP_FRAG_TIME; /* about 30 seconds */
808 qp->timer.data = (unsigned long) qp; /* pointer to queue */
809 qp->timer.function = ip_expire; /* expire function */
810 add_timer(&qp->timer);
811
812 /* Add this entry to the queue. */
813 qp->prev = NULL;
814 cli();
815 qp->next = ipqueue;
816 if (qp->next != NULL)
817 qp->next->prev = qp;
818 ipqueue = qp;
819 sti();
820 return(qp);
821 }
822
823
824 /*
825 * See if a fragment queue is complete.
826 */
827
828 static int ip_done(struct ipq *qp)
/* */
829 {
830 struct ipfrag *fp;
831 int offset;
832
833 /* Only possible if we received the final fragment. */
834 if (qp->len == 0)
835 return(0);
836
837 /* Check all fragment offsets to see if they connect. */
838 fp = qp->fragments;
839 offset = 0;
840 while (fp != NULL)
841 {
842 if (fp->offset > offset)
843 return(0); /* fragment(s) missing */
844 offset = fp->end;
845 fp = fp->next;
846 }
847
848 /* All fragments are present. */
849 return(1);
850 }
851
852
853 /*
854 * Build a new IP datagram from all its fragments.
855 *
856 * FIXME: We copy here because we lack an effective way of handling lists
857 * of bits on input. Until the new skb data handling is in I'm not going
858 * to touch this with a bargepole. This also causes a 4Kish limit on
859 * packet sizes.
860 */
861
862 static struct sk_buff *ip_glue(struct ipq *qp)
/* */
863 {
864 struct sk_buff *skb;
865 struct iphdr *iph;
866 struct ipfrag *fp;
867 unsigned char *ptr;
868 int count, len;
869
870 /*
871 * Allocate a new buffer for the datagram.
872 */
873
874 len = qp->maclen + qp->ihlen + qp->len;
875
876 if ((skb = alloc_skb(len,GFP_ATOMIC)) == NULL)
877 {
878 ip_statistics.IpReasmFails++;
879 printk("IP: queue_glue: no memory for gluing queue 0x%X\n", (int) qp);
880 ip_free(qp);
881 return(NULL);
882 }
883
884 /* Fill in the basic details. */
885 skb->len = (len - qp->maclen);
886 skb->h.raw = skb->data;
887 skb->free = 1;
888
889 /* Copy the original MAC and IP headers into the new buffer. */
890 ptr = (unsigned char *) skb->h.raw;
891 memcpy(ptr, ((unsigned char *) qp->mac), qp->maclen);
892 ptr += qp->maclen;
893 memcpy(ptr, ((unsigned char *) qp->iph), qp->ihlen);
894 ptr += qp->ihlen;
895 skb->h.raw += qp->maclen;
896
897 count = 0;
898
899 /* Copy the data portions of all fragments into the new buffer. */
900 fp = qp->fragments;
901 while(fp != NULL)
902 {
903 if(count+fp->len > skb->len)
904 {
905 printk("Invalid fragment list: Fragment over size.\n");
906 ip_free(qp);
907 kfree_skb(skb,FREE_WRITE);
908 ip_statistics.IpReasmFails++;
909 return NULL;
910 }
911 memcpy((ptr + fp->offset), fp->ptr, fp->len);
912 count += fp->len;
913 fp = fp->next;
914 }
915
916 /* We glued together all fragments, so remove the queue entry. */
917 ip_free(qp);
918
919 /* Done with all fragments. Fixup the new IP header. */
920 iph = skb->h.iph;
921 iph->frag_off = 0;
922 iph->tot_len = htons((iph->ihl * sizeof(unsigned long)) + count);
923 skb->ip_hdr = iph;
924
925 ip_statistics.IpReasmOKs++;
926 return(skb);
927 }
928
929
930 /*
931 * Process an incoming IP datagram fragment.
932 */
933
934 static struct sk_buff *ip_defrag(struct iphdr *iph, struct sk_buff *skb, struct device *dev)
/* */
935 {
936 struct ipfrag *prev, *next;
937 struct ipfrag *tfp;
938 struct ipq *qp;
939 struct sk_buff *skb2;
940 unsigned char *ptr;
941 int flags, offset;
942 int i, ihl, end;
943
944 ip_statistics.IpReasmReqds++;
945
946 /* Find the entry of this IP datagram in the "incomplete datagrams" queue. */
947 qp = ip_find(iph);
948
949 /* Is this a non-fragmented datagram? */
950 offset = ntohs(iph->frag_off);
951 flags = offset & ~IP_OFFSET;
952 offset &= IP_OFFSET;
953 if (((flags & IP_MF) == 0) && (offset == 0))
954 {
955 if (qp != NULL)
956 ip_free(qp); /* Huh? How could this exist?? */
957 return(skb);
958 }
959
960 offset <<= 3; /* offset is in 8-byte chunks */
961
962 /*
963 * If the queue already existed, keep restarting its timer as long
964 * as we still are receiving fragments. Otherwise, create a fresh
965 * queue entry.
966 */
967
968 if (qp != NULL)
969 {
970 del_timer(&qp->timer);
971 qp->timer.expires = IP_FRAG_TIME; /* about 30 seconds */
972 qp->timer.data = (unsigned long) qp; /* pointer to queue */
973 qp->timer.function = ip_expire; /* expire function */
974 add_timer(&qp->timer);
975 }
976 else
977 {
978 /*
979 * If we failed to create it, then discard the frame
980 */
981 if ((qp = ip_create(skb, iph, dev)) == NULL)
982 {
983 skb->sk = NULL;
984 kfree_skb(skb, FREE_READ);
985 ip_statistics.IpReasmFails++;
986 return NULL;
987 }
988 }
989
990 /*
991 * Determine the position of this fragment.
992 */
993
994 ihl = (iph->ihl * sizeof(unsigned long));
995 end = offset + ntohs(iph->tot_len) - ihl;
996
997 /*
998 * Point into the IP datagram 'data' part.
999 */
1000
1001 ptr = skb->data + dev->hard_header_len + ihl;
1002
1003 /*
1004 * Is this the final fragment?
1005 */
1006
1007 if ((flags & IP_MF) == 0)
1008 qp->len = end;
1009
1010 /*
1011 * Find out which fragments are in front and at the back of us
1012 * in the chain of fragments so far. We must know where to put
1013 * this fragment, right?
1014 */
1015
1016 prev = NULL;
1017 for(next = qp->fragments; next != NULL; next = next->next)
1018 {
1019 if (next->offset > offset)
1020 break; /* bingo! */
1021 prev = next;
1022 }
1023
1024 /*
1025 * We found where to put this one.
1026 * Check for overlap with preceding fragment, and, if needed,
1027 * align things so that any overlaps are eliminated.
1028 */
1029 if (prev != NULL && offset < prev->end)
1030 {
1031 i = prev->end - offset;
1032 offset += i; /* ptr into datagram */
1033 ptr += i; /* ptr into fragment data */
1034 }
1035
1036 /*
1037 * Look for overlap with succeeding segments.
1038 * If we can merge fragments, do it.
1039 */
1040
1041 for(; next != NULL; next = tfp)
1042 {
1043 tfp = next->next;
1044 if (next->offset >= end)
1045 break; /* no overlaps at all */
1046
1047 i = end - next->offset; /* overlap is 'i' bytes */
1048 next->len -= i; /* so reduce size of */
1049 next->offset += i; /* next fragment */
1050 next->ptr += i;
1051
1052 /*
1053 * If we get a frag size of <= 0, remove it and the packet
1054 * that it goes with.
1055 */
1056 if (next->len <= 0)
1057 {
1058 if (next->prev != NULL)
1059 next->prev->next = next->next;
1060 else
1061 qp->fragments = next->next;
1062
1063 if (tfp->next != NULL)
1064 next->next->prev = next->prev;
1065
1066 kfree_skb(next->skb,FREE_READ);
1067 kfree_s(next, sizeof(struct ipfrag));
1068 }
1069 }
1070
1071 /*
1072 * Insert this fragment in the chain of fragments.
1073 */
1074
1075 tfp = NULL;
1076 tfp = ip_frag_create(offset, end, skb, ptr);
1077
1078 /*
1079 * No memory to save the fragment - so throw the lot
1080 */
1081
1082 if (!tfp)
1083 {
1084 skb->sk = NULL;
1085 kfree_skb(skb, FREE_READ);
1086 return NULL;
1087 }
1088 tfp->prev = prev;
1089 tfp->next = next;
1090 if (prev != NULL)
1091 prev->next = tfp;
1092 else
1093 qp->fragments = tfp;
1094
1095 if (next != NULL)
1096 next->prev = tfp;
1097
1098 /*
1099 * OK, so we inserted this new fragment into the chain.
1100 * Check if we now have a full IP datagram which we can
1101 * bump up to the IP layer...
1102 */
1103
1104 if (ip_done(qp))
1105 {
1106 skb2 = ip_glue(qp); /* glue together the fragments */
1107 return(skb2);
1108 }
1109 return(NULL);
1110 }
1111
1112
1113 /*
1114 * This IP datagram is too large to be sent in one piece. Break it up into
1115 * smaller pieces (each of size equal to the MAC header plus IP header plus
1116 * a block of the data of the original IP data part) that will yet fit in a
1117 * single device frame, and queue such a frame for sending by calling the
1118 * ip_queue_xmit(). Note that this is recursion, and bad things will happen
1119 * if this function causes a loop...
1120 *
1121 * Yes this is inefficient, feel free to submit a quicker one.
1122 *
1123 * **Protocol Violation**
1124 * We copy all the options to each fragment. !FIXME!
1125 */
1126 void ip_fragment(struct sock *sk, struct sk_buff *skb, struct device *dev, int is_frag)
/* */
1127 {
1128 struct iphdr *iph;
1129 unsigned char *raw;
1130 unsigned char *ptr;
1131 struct sk_buff *skb2;
1132 int left, mtu, hlen, len;
1133 int offset;
1134 unsigned long flags;
1135
1136 /*
1137 * Point into the IP datagram header.
1138 */
1139
1140 raw = skb->data;
1141 iph = (struct iphdr *) (raw + dev->hard_header_len);
1142
1143 skb->ip_hdr = iph;
1144
1145 /*
1146 * Setup starting values.
1147 */
1148
1149 hlen = (iph->ihl * sizeof(unsigned long));
1150 left = ntohs(iph->tot_len) - hlen; /* Space per frame */
1151 hlen += dev->hard_header_len; /* Total header size */
1152 mtu = (dev->mtu - hlen); /* Size of data space */
1153 ptr = (raw + hlen); /* Where to start from */
1154
1155 /*
1156 * Check for any "DF" flag. [DF means do not fragment]
1157 */
1158
1159 if (ntohs(iph->frag_off) & IP_DF)
1160 {
1161 ip_statistics.IpFragFails++;
1162 icmp_send(skb,ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, dev);
1163 return;
1164 }
1165
1166 /*
1167 * The protocol doesn't seem to say what to do in the case that the
1168 * frame + options doesn't fit the mtu. As it used to fall down dead
1169 * in this case we were fortunate it didn't happen
1170 */
1171
1172 if(mtu<8)
1173 {
1174 /* It's wrong but its better than nothing */
1175 icmp_send(skb,ICMP_DEST_UNREACH,ICMP_FRAG_NEEDED,dev);
1176 ip_statistics.IpFragFails++;
1177 return;
1178 }
1179
1180 /*
1181 * Fragment the datagram.
1182 */
1183
1184 /*
1185 * The initial offset is 0 for a complete frame. When
1186 * fragmenting fragments its wherever this one starts.
1187 */
1188
1189 if (is_frag & 2)
1190 offset = (ntohs(iph->frag_off) & 0x1fff) << 3;
1191 else
1192 offset = 0;
1193
1194
1195 /*
1196 * Keep copying data until we run out.
1197 */
1198
1199 while(left > 0)
1200 {
1201 len = left;
1202 /* IF: it doesn't fit, use 'mtu' - the data space left */
1203 if (len > mtu)
1204 len = mtu;
1205 /* IF: we are not sending upto and including the packet end
1206 then align the next start on an eight byte boundary */
1207 if (len < left)
1208 {
1209 len/=8;
1210 len*=8;
1211 }
1212 /*
1213 * Allocate buffer.
1214 */
1215
1216 if ((skb2 = alloc_skb(len + hlen,GFP_ATOMIC)) == NULL)
1217 {
1218 printk("IP: frag: no memory for new fragment!\n");
1219 ip_statistics.IpFragFails++;
1220 return;
1221 }
1222
1223 /*
1224 * Set up data on packet
1225 */
1226
1227 skb2->arp = skb->arp;
1228 if(skb->free==0)
1229 printk("IP fragmenter: BUG free!=1 in fragmenter\n");
1230 skb2->free = 1;
1231 skb2->len = len + hlen;
1232 skb2->h.raw=(char *) skb2->data;
1233 /*
1234 * Charge the memory for the fragment to any owner
1235 * it might possess
1236 */
1237
1238 save_flags(flags);
1239 if (sk)
1240 {
1241 cli();
1242 sk->wmem_alloc += skb2->mem_len;
1243 skb2->sk=sk;
1244 }
1245 restore_flags(flags);
1246 skb2->raddr = skb->raddr; /* For rebuild_header - must be here */
1247
1248 /*
1249 * Copy the packet header into the new buffer.
1250 */
1251
1252 memcpy(skb2->h.raw, raw, hlen);
1253
1254 /*
1255 * Copy a block of the IP datagram.
1256 */
1257 memcpy(skb2->h.raw + hlen, ptr, len);
1258 left -= len;
1259
1260 skb2->h.raw+=dev->hard_header_len;
1261
1262 /*
1263 * Fill in the new header fields.
1264 */
1265 iph = (struct iphdr *)(skb2->h.raw/*+dev->hard_header_len*/);
1266 iph->frag_off = htons((offset >> 3));
1267 /*
1268 * Added AC : If we are fragmenting a fragment thats not the
1269 * last fragment then keep MF on each bit
1270 */
1271 if (left > 0 || (is_frag & 1))
1272 iph->frag_off |= htons(IP_MF);
1273 ptr += len;
1274 offset += len;
1275
1276 /*
1277 * Put this fragment into the sending queue.
1278 */
1279
1280 ip_statistics.IpFragCreates++;
1281
1282 ip_queue_xmit(sk, dev, skb2, 2);
1283 }
1284 ip_statistics.IpFragOKs++;
1285 }
1286
1287
1288
1289 #ifdef CONFIG_IP_FORWARD
1290
1291 /*
1292 * Forward an IP datagram to its next destination.
1293 */
1294
1295 static void ip_forward(struct sk_buff *skb, struct device *dev, int is_frag)
/* */
1296 {
1297 struct device *dev2; /* Output device */
1298 struct iphdr *iph; /* Our header */
1299 struct sk_buff *skb2; /* Output packet */
1300 struct rtable *rt; /* Route we use */
1301 unsigned char *ptr; /* Data pointer */
1302 unsigned long raddr; /* Router IP address */
1303
1304 /*
1305 * See if we are allowed to forward this.
1306 */
1307
1308 #ifdef CONFIG_IP_FIREWALL
1309 if(!ip_fw_chk(skb->h.iph, ip_fw_fwd_chain))
1310 {
1311 return;
1312 }
1313 #endif
1314 /*
1315 * According to the RFC, we must first decrease the TTL field. If
1316 * that reaches zero, we must reply an ICMP control message telling
1317 * that the packet's lifetime expired.
1318 *
1319 * Exception:
1320 * We may not generate an ICMP for an ICMP. icmp_send does the
1321 * enforcement of this so we can forget it here. It is however
1322 * sometimes VERY important.
1323 */
1324
1325 iph = skb->h.iph;
1326 iph->ttl--;
1327 if (iph->ttl <= 0)
1328 {
1329 /* Tell the sender its packet died... */
1330 icmp_send(skb, ICMP_TIME_EXCEEDED, ICMP_EXC_TTL, dev);
1331 return;
1332 }
1333
1334 /*
1335 * Re-compute the IP header checksum.
1336 * This is inefficient. We know what has happened to the header
1337 * and could thus adjust the checksum as Phil Karn does in KA9Q
1338 */
1339
1340 ip_send_check(iph);
1341
1342 /*
1343 * OK, the packet is still valid. Fetch its destination address,
1344 * and give it to the IP sender for further processing.
1345 */
1346
1347 rt = ip_rt_route(iph->daddr, NULL, NULL);
1348 if (rt == NULL)
1349 {
1350 /*
1351 * Tell the sender its packet cannot be delivered. Again
1352 * ICMP is screened later.
1353 */
1354 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_NET_UNREACH, dev);
1355 return;
1356 }
1357
1358
1359 /*
1360 * Gosh. Not only is the packet valid; we even know how to
1361 * forward it onto its final destination. Can we say this
1362 * is being plain lucky?
1363 * If the router told us that there is no GW, use the dest.
1364 * IP address itself- we seem to be connected directly...
1365 */
1366
1367 raddr = rt->rt_gateway;
1368
1369 if (raddr != 0)
1370 {
1371 /*
1372 * There is a gateway so find the correct route for it.
1373 * Gateways cannot in turn be gatewayed.
1374 */
1375 rt = ip_rt_route(raddr, NULL, NULL);
1376 if (rt == NULL)
1377 {
1378 /*
1379 * Tell the sender its packet cannot be delivered...
1380 */
1381 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, dev);
1382 return;
1383 }
1384 if (rt->rt_gateway != 0)
1385 raddr = rt->rt_gateway;
1386 }
1387 else
1388 raddr = iph->daddr;
1389
1390 /*
1391 * Having picked a route we can now send the frame out.
1392 */
1393
1394 dev2 = rt->rt_dev;
1395
1396 /*
1397 * In IP you never forward a frame on the interface that it arrived
1398 * upon. We should generate an ICMP HOST REDIRECT giving the route
1399 * we calculated.
1400 * For now just dropping the packet is an acceptable compromise.
1401 */
1402
1403 if (dev == dev2)
1404 return;
1405
1406 /*
1407 * We now allocate a new buffer, and copy the datagram into it.
1408 * If the indicated interface is up and running, kick it.
1409 */
1410
1411 if (dev2->flags & IFF_UP)
1412 {
1413
1414 /*
1415 * Current design decrees we copy the packet. For identical header
1416 * lengths we could avoid it. The new skb code will let us push
1417 * data so the problem goes away then.
1418 */
1419
1420 skb2 = alloc_skb(dev2->hard_header_len + skb->len, GFP_ATOMIC);
1421 /*
1422 * This is rare and since IP is tolerant of network failures
1423 * quite harmless.
1424 */
1425 if (skb2 == NULL)
1426 {
1427 printk("\nIP: No memory available for IP forward\n");
1428 return;
1429 }
1430 ptr = skb2->data;
1431 skb2->free = 1;
1432 skb2->len = skb->len + dev2->hard_header_len;
1433 skb2->h.raw = ptr;
1434
1435 /*
1436 * Copy the packet data into the new buffer.
1437 */
1438 memcpy(ptr + dev2->hard_header_len, skb->h.raw, skb->len);
1439
1440 /* Now build the MAC header. */
1441 (void) ip_send(skb2, raddr, skb->len, dev2, dev2->pa_addr);
1442
1443 ip_statistics.IpForwDatagrams++;
1444
1445 /*
1446 * See if it needs fragmenting. Note in ip_rcv we tagged
1447 * the fragment type. This must be right so that
1448 * the fragmenter does the right thing.
1449 */
1450
1451 if(skb2->len > dev2->mtu + dev2->hard_header_len)
1452 {
1453 ip_fragment(NULL,skb2,dev2, is_frag);
1454 kfree_skb(skb2,FREE_WRITE);
1455 }
1456 else
1457 {
1458 #ifdef CONFIG_IP_ACCT
1459 /*
1460 * Count mapping we shortcut
1461 */
1462
1463 ip_acct_cnt(iph,ip_acct_chain,1);
1464 #endif
1465
1466 /*
1467 * Map service types to priority. We lie about
1468 * throughput being low priority, but its a good
1469 * choice to help improve general usage.
1470 */
1471 if(iph->tos & IPTOS_LOWDELAY)
1472 dev_queue_xmit(skb2, dev2, SOPRI_INTERACTIVE);
1473 else if(iph->tos & IPTOS_THROUGHPUT)
1474 dev_queue_xmit(skb2, dev2, SOPRI_BACKGROUND);
1475 else
1476 dev_queue_xmit(skb2, dev2, SOPRI_NORMAL);
1477 }
1478 }
1479 }
1480
1481
1482 #endif
1483
1484 /*
1485 * This function receives all incoming IP datagrams.
1486 */
1487
1488 int ip_rcv(struct sk_buff *skb, struct device *dev, struct packet_type *pt)
/* */
1489 {
1490 struct iphdr *iph = skb->h.iph;
1491 struct sock *raw_sk=NULL;
1492 unsigned char hash;
1493 unsigned char flag = 0;
1494 unsigned char opts_p = 0; /* Set iff the packet has options. */
1495 struct inet_protocol *ipprot;
1496 static struct options opt; /* since we don't use these yet, and they
1497 take up stack space. */
1498 int brd=IS_MYADDR;
1499 int is_frag=0;
1500
1501 ip_statistics.IpInReceives++;
1502
1503 /*
1504 * Tag the ip header of this packet so we can find it
1505 */
1506
1507 skb->ip_hdr = iph;
1508
1509 /*
1510 * Is the datagram acceptable?
1511 *
1512 * 1. Length at least the size of an ip header
1513 * 2. Version of 4
1514 * 3. Checksums correctly. [Speed optimisation for later, skip loopback checksums]
1515 * (4. We ought to check for IP multicast addresses and undefined types.. does this matter ?)
1516 */
1517
1518 if (skb->len<sizeof(struct iphdr) || iph->ihl<5 || iph->version != 4 || ip_fast_csum((unsigned char *)iph, iph->ihl) !=0)
1519 {
1520 ip_statistics.IpInHdrErrors++;
1521 kfree_skb(skb, FREE_WRITE);
1522 return(0);
1523 }
1524
1525 /*
1526 * See if the firewall wants to dispose of the packet.
1527 */
1528
1529 #ifdef CONFIG_IP_FIREWALL
1530
1531 if(!LOOPBACK(iph->daddr) && !ip_fw_chk(iph,ip_fw_blk_chain))
1532 {
1533 kfree_skb(skb, FREE_WRITE);
1534 return 0;
1535 }
1536
1537 #endif
1538
1539 /*
1540 * Our transport medium may have padded the buffer out. Now we know it
1541 * is IP we can trim to the true length of the frame.
1542 */
1543
1544 skb->len=ntohs(iph->tot_len);
1545
1546 /*
1547 * Next analyse the packet for options. Studies show under one packet in
1548 * a thousand have options....
1549 */
1550
1551 if (iph->ihl != 5)
1552 { /* Fast path for the typical optionless IP packet. */
1553 memset((char *) &opt, 0, sizeof(opt));
1554 if (do_options(iph, &opt) != 0)
1555 return 0;
1556 opts_p = 1;
1557 }
1558
1559 /*
1560 * Remember if the frame is fragmented.
1561 */
1562
1563 if(iph->frag_off)
1564 {
1565 if (iph->frag_off & 0x0020)
1566 is_frag|=1;
1567 /*
1568 * Last fragment ?
1569 */
1570
1571 if (ntohs(iph->frag_off) & 0x1fff)
1572 is_frag|=2;
1573 }
1574
1575 /*
1576 * Do any IP forwarding required. chk_addr() is expensive -- avoid it someday.
1577 *
1578 * This is inefficient. While finding out if it is for us we could also compute
1579 * the routing table entry. This is where the great unified cache theory comes
1580 * in as and when someone implements it
1581 *
1582 * For most hosts over 99% of packets match the first conditional
1583 * and don't go via ip_chk_addr. Note: brd is set to IS_MYADDR at
1584 * function entry.
1585 */
1586
1587 if ( iph->daddr != skb->dev->pa_addr && (brd = ip_chk_addr(iph->daddr)) == 0)
1588 {
1589 /*
1590 * Don't forward multicast or broadcast frames.
1591 */
1592
1593 if(skb->pkt_type!=PACKET_HOST || brd==IS_BROADCAST)
1594 {
1595 kfree_skb(skb,FREE_WRITE);
1596 return 0;
1597 }
1598
1599 /*
1600 * The packet is for another target. Forward the frame
1601 */
1602
1603 #ifdef CONFIG_IP_FORWARD
1604 ip_forward(skb, dev, is_frag);
1605 #else
1606 /* printk("Machine %lx tried to use us as a forwarder to %lx but we have forwarding disabled!\n",
1607 iph->saddr,iph->daddr);*/
1608 ip_statistics.IpInAddrErrors++;
1609 #endif
1610 /*
1611 * The forwarder is inefficient and copies the packet. We
1612 * free the original now.
1613 */
1614
1615 kfree_skb(skb, FREE_WRITE);
1616 return(0);
1617 }
1618
1619 #ifdef CONFIG_IP_MULTICAST
1620
1621 if(brd==IS_MULTICAST && iph->daddr!=IGMP_ALL_HOSTS && !(dev->flags&IFF_LOOPBACK))
1622 {
1623 /*
1624 * Check it is for one of our groups
1625 */
1626 struct ip_mc_list *ip_mc=dev->ip_mc_list;
1627 do
1628 {
1629 if(ip_mc==NULL)
1630 {
1631 kfree_skb(skb, FREE_WRITE);
1632 return 0;
1633 }
1634 if(ip_mc->multiaddr==iph->daddr)
1635 break;
1636 ip_mc=ip_mc->next;
1637 }
1638 while(1);
1639 }
1640 #endif
1641 /*
1642 * Account for the packet
1643 */
1644
1645 #ifdef CONFIG_IP_ACCT
1646 ip_acct_cnt(iph,ip_acct_chain,1);
1647 #endif
1648
1649 /*
1650 * Reassemble IP fragments.
1651 */
1652
1653 if(is_frag)
1654 {
1655 /* Defragment. Obtain the complete packet if there is one */
1656 skb=ip_defrag(iph,skb,dev);
1657 if(skb==NULL)
1658 return 0;
1659 skb->dev = dev;
1660 iph=skb->h.iph;
1661 }
1662
1663
1664
1665 /*
1666 * Point into the IP datagram, just past the header.
1667 */
1668
1669 skb->ip_hdr = iph;
1670 skb->h.raw += iph->ihl*4;
1671
1672 /*
1673 * Deliver to raw sockets. This is fun as to avoid copies we want to make no surplus copies.
1674 */
1675
1676 hash = iph->protocol & (SOCK_ARRAY_SIZE-1);
1677
1678 /* If there maybe a raw socket we must check - if not we don't care less */
1679 if((raw_sk=raw_prot.sock_array[hash])!=NULL)
1680 {
1681 struct sock *sknext=NULL;
1682 struct sk_buff *skb1;
1683 raw_sk=get_sock_raw(raw_sk, hash, iph->saddr, iph->daddr);
1684 if(raw_sk) /* Any raw sockets */
1685 {
1686 do
1687 {
1688 /* Find the next */
1689 sknext=get_sock_raw(raw_sk->next, hash, iph->saddr, iph->daddr);
1690 if(sknext)
1691 skb1=skb_clone(skb, GFP_ATOMIC);
1692 else
1693 break; /* One pending raw socket left */
1694 if(skb1)
1695 raw_rcv(raw_sk, skb1, dev, iph->saddr,iph->daddr);
1696 raw_sk=sknext;
1697 }
1698 while(raw_sk!=NULL);
1699 /* Here either raw_sk is the last raw socket, or NULL if none */
1700 /* We deliver to the last raw socket AFTER the protocol checks as it avoids a surplus copy */
1701 }
1702 }
1703
1704 /*
1705 * skb->h.raw now points at the protocol beyond the IP header.
1706 */
1707
1708 hash = iph->protocol & (MAX_INET_PROTOS -1);
1709 for (ipprot = (struct inet_protocol *)inet_protos[hash];ipprot != NULL;ipprot=(struct inet_protocol *)ipprot->next)
1710 {
1711 struct sk_buff *skb2;
1712
1713 if (ipprot->protocol != iph->protocol)
1714 continue;
1715 /*
1716 * See if we need to make a copy of it. This will
1717 * only be set if more than one protocol wants it.
1718 * and then not for the last one. If there is a pending
1719 * raw delivery wait for that
1720 */
1721 if (ipprot->copy || raw_sk)
1722 {
1723 skb2 = skb_clone(skb, GFP_ATOMIC);
1724 if(skb2==NULL)
1725 continue;
1726 }
1727 else
1728 {
1729 skb2 = skb;
1730 }
1731 flag = 1;
1732
1733 /*
1734 * Pass on the datagram to each protocol that wants it,
1735 * based on the datagram protocol. We should really
1736 * check the protocol handler's return values here...
1737 */
1738 ipprot->handler(skb2, dev, opts_p ? &opt : 0, iph->daddr,
1739 (ntohs(iph->tot_len) - (iph->ihl * 4)),
1740 iph->saddr, 0, ipprot);
1741
1742 }
1743
1744 /*
1745 * All protocols checked.
1746 * If this packet was a broadcast, we may *not* reply to it, since that
1747 * causes (proven, grin) ARP storms and a leakage of memory (i.e. all
1748 * ICMP reply messages get queued up for transmission...)
1749 */
1750
1751 if(raw_sk!=NULL) /* Shift to last raw user */
1752 raw_rcv(raw_sk, skb, dev, iph->saddr, iph->daddr);
1753 else if (!flag) /* Free and report errors */
1754 {
1755 if (brd != IS_BROADCAST && brd!=IS_MULTICAST)
1756 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PROT_UNREACH, dev);
1757 kfree_skb(skb, FREE_WRITE);
1758 }
1759
1760 return(0);
1761 }
1762
1763 /*
1764 * Loop a packet back to the sender.
1765 */
1766
1767 static void ip_loopback(struct device *old_dev, struct sk_buff *skb)
/* */
1768 {
1769 extern struct device loopback_dev;
1770 struct device *dev=&loopback_dev;
1771 int len=skb->len-old_dev->hard_header_len;
1772 struct sk_buff *newskb=alloc_skb(len+dev->hard_header_len, GFP_ATOMIC);
1773
1774 if(newskb==NULL)
1775 return;
1776
1777 newskb->link3=NULL;
1778 newskb->sk=NULL;
1779 newskb->dev=dev;
1780 newskb->saddr=skb->saddr;
1781 newskb->daddr=skb->daddr;
1782 newskb->raddr=skb->raddr;
1783 newskb->free=1;
1784 newskb->lock=0;
1785 newskb->users=0;
1786 newskb->pkt_type=skb->pkt_type;
1787 newskb->len=len+dev->hard_header_len;
1788
1789
1790 newskb->ip_hdr=(struct iphdr *)(newskb->data+ip_send(newskb, skb->ip_hdr->daddr, len, dev, skb->ip_hdr->saddr));
1791 memcpy(newskb->ip_hdr,skb->ip_hdr,len);
1792
1793 /* Recurse. The device check against IFF_LOOPBACK will stop infinite recursion */
1794
1795 /*printk("Loopback output queued [%lX to %lX].\n", newskb->ip_hdr->saddr,newskb->ip_hdr->daddr);*/
1796 ip_queue_xmit(NULL, dev, newskb, 1);
1797 }
1798
1799
1800 /*
1801 * Queues a packet to be sent, and starts the transmitter
1802 * if necessary. if free = 1 then we free the block after
1803 * transmit, otherwise we don't. If free==2 we not only
1804 * free the block but also don't assign a new ip seq number.
1805 * This routine also needs to put in the total length,
1806 * and compute the checksum
1807 */
1808
1809 void ip_queue_xmit(struct sock *sk, struct device *dev,
/* */
1810 struct sk_buff *skb, int free)
1811 {
1812 struct iphdr *iph;
1813 unsigned char *ptr;
1814
1815 /* Sanity check */
1816 if (dev == NULL)
1817 {
1818 printk("IP: ip_queue_xmit dev = NULL\n");
1819 return;
1820 }
1821
1822 IS_SKB(skb);
1823
1824 /*
1825 * Do some book-keeping in the packet for later
1826 */
1827
1828
1829 skb->dev = dev;
1830 skb->when = jiffies;
1831
1832 /*
1833 * Find the IP header and set the length. This is bad
1834 * but once we get the skb data handling code in the
1835 * hardware will push its header sensibly and we will
1836 * set skb->ip_hdr to avoid this mess and the fixed
1837 * header length problem
1838 */
1839
1840 ptr = skb->data;
1841 ptr += dev->hard_header_len;
1842 iph = (struct iphdr *)ptr;
1843 skb->ip_hdr = iph;
1844 iph->tot_len = ntohs(skb->len-dev->hard_header_len);
1845
1846 /*
1847 * No reassigning numbers to fragments...
1848 */
1849
1850 if(free!=2)
1851 iph->id = htons(ip_id_count++);
1852 else
1853 free=1;
1854
1855 /* All buffers without an owner socket get freed */
1856 if (sk == NULL)
1857 free = 1;
1858
1859 skb->free = free;
1860
1861 /*
1862 * Do we need to fragment. Again this is inefficient.
1863 * We need to somehow lock the original buffer and use
1864 * bits of it.
1865 */
1866
1867 if(skb->len > dev->mtu + dev->hard_header_len)
1868 {
1869 ip_fragment(sk,skb,dev,0);
1870 IS_SKB(skb);
1871 kfree_skb(skb,FREE_WRITE);
1872 return;
1873 }
1874
1875 /*
1876 * Add an IP checksum
1877 */
1878
1879 ip_send_check(iph);
1880
1881 /*
1882 * Print the frame when debugging
1883 */
1884
1885 /*
1886 * More debugging. You cannot queue a packet already on a list
1887 * Spot this and moan loudly.
1888 */
1889 if (skb->next != NULL)
1890 {
1891 printk("ip_queue_xmit: next != NULL\n");
1892 skb_unlink(skb);
1893 }
1894
1895 /*
1896 * If a sender wishes the packet to remain unfreed
1897 * we add it to his send queue. This arguably belongs
1898 * in the TCP level since nobody else uses it. BUT
1899 * remember IPng might change all the rules.
1900 */
1901
1902 if (!free)
1903 {
1904 unsigned long flags;
1905 /* The socket now has more outstanding blocks */
1906
1907 sk->packets_out++;
1908
1909 /* Protect the list for a moment */
1910 save_flags(flags);
1911 cli();
1912
1913 if (skb->link3 != NULL)
1914 {
1915 printk("ip.c: link3 != NULL\n");
1916 skb->link3 = NULL;
1917 }
1918 if (sk->send_head == NULL)
1919 {
1920 sk->send_tail = skb;
1921 sk->send_head = skb;
1922 }
1923 else
1924 {
1925 sk->send_tail->link3 = skb;
1926 sk->send_tail = skb;
1927 }
1928 /* skb->link3 is NULL */
1929
1930 /* Interrupt restore */
1931 restore_flags(flags);
1932 }
1933 else
1934 /* Remember who owns the buffer */
1935 skb->sk = sk;
1936
1937 /*
1938 * If the indicated interface is up and running, send the packet.
1939 */
1940
1941 ip_statistics.IpOutRequests++;
1942 #ifdef CONFIG_IP_ACCT
1943 ip_acct_cnt(iph,ip_acct_chain,1);
1944 #endif
1945
1946 #ifdef CONFIG_IP_MULTICAST
1947
1948 /*
1949 * Multicasts are looped back for other local users
1950 */
1951
1952 if (MULTICAST(iph->daddr) && !(dev->flags&IFF_LOOPBACK))
1953 {
1954 if(sk==NULL || sk->ip_mc_loop)
1955 {
1956 if(iph->daddr==IGMP_ALL_HOSTS)
1957 ip_loopback(dev,skb);
1958 else
1959 {
1960 struct ip_mc_list *imc=dev->ip_mc_list;
1961 while(imc!=NULL)
1962 {
1963 if(imc->multiaddr==iph->daddr)
1964 {
1965 ip_loopback(dev,skb);
1966 break;
1967 }
1968 imc=imc->next;
1969 }
1970 }
1971 }
1972 /* Multicasts with ttl 0 must not go beyond the host */
1973
1974 if(skb->ip_hdr->ttl==0)
1975 {
1976 kfree_skb(skb, FREE_READ);
1977 return;
1978 }
1979 }
1980 #endif
1981 if((dev->flags&IFF_BROADCAST) && iph->daddr==dev->pa_brdaddr && !(dev->flags&IFF_LOOPBACK))
1982 ip_loopback(dev,skb);
1983
1984 if (dev->flags & IFF_UP)
1985 {
1986 /*
1987 * If we have an owner use its priority setting,
1988 * otherwise use NORMAL
1989 */
1990
1991 if (sk != NULL)
1992 {
1993 dev_queue_xmit(skb, dev, sk->priority);
1994 }
1995 else
1996 {
1997 dev_queue_xmit(skb, dev, SOPRI_NORMAL);
1998 }
1999 }
2000 else
2001 {
2002 ip_statistics.IpOutDiscards++;
2003 if (free)
2004 kfree_skb(skb, FREE_WRITE);
2005 }
2006 }
2007
2008
2009
2010 #ifdef CONFIG_IP_MULTICAST
2011
2012 /*
2013 * Write an multicast group list table for the IGMP daemon to
2014 * read.
2015 */
2016
2017 int ip_mc_procinfo(char *buffer, char **start, off_t offset, int length)
/* */
2018 {
2019 off_t pos=0, begin=0;
2020 struct ip_mc_list *im;
2021 unsigned long flags;
2022 int len=0;
2023
2024
2025 len=sprintf(buffer,"Device : Multicast\n");
2026 save_flags(flags);
2027 cli();
2028
2029 im=ip_mc_head;
2030
2031 while(im!=NULL)
2032 {
2033 len+=sprintf(buffer+len,"%-10s: %08lX\n", im->interface->name, im->multiaddr);
2034 pos=begin+len;
2035 if(pos<offset)
2036 {
2037 len=0;
2038 begin=pos;
2039 }
2040 if(pos>offset+length)
2041 break;
2042 im=im->next;
2043 }
2044 restore_flags(flags);
2045 *start=buffer+(offset-begin);
2046 len-=(offset-begin);
2047 if(len>length)
2048 len=length;
2049 return len;
2050 }
2051
2052
2053 #endif
2054 /*
2055 * Socket option code for IP. This is the end of the line after any TCP,UDP etc options on
2056 * an IP socket.
2057 *
2058 * We implement IP_TOS (type of service), IP_TTL (time to live).
2059 *
2060 * Next release we will sort out IP_OPTIONS since for some people are kind of important.
2061 */
2062
2063 int ip_setsockopt(struct sock *sk, int level, int optname, char *optval, int optlen)
/* */
2064 {
2065 int val,err;
2066 #if defined(CONFIG_IP_FIREWALL) || defined(CONFIG_IP_ACCT)
2067 struct ip_fw tmp_fw;
2068 #endif
2069 if (optval == NULL)
2070 return(-EINVAL);
2071
2072 err=verify_area(VERIFY_READ, optval, sizeof(int));
2073 if(err)
2074 return err;
2075
2076 val = get_fs_long((unsigned long *)optval);
2077
2078 if(level!=SOL_IP)
2079 return -EOPNOTSUPP;
2080
2081 #ifdef CONFIG_IP_MULTICAST
2082 if(optname==IP_MULTICAST_TTL)
2083 {
2084 unsigned char ucval;
2085 ucval=get_fs_byte((unsigned char *)optval);
2086 printk("MC TTL %d\n", ucval);
2087 if(ucval<1||ucval>255)
2088 return -EINVAL;
2089 sk->ip_mc_ttl=(int)ucval;
2090 return 0;
2091 }
2092 #endif
2093
2094 switch(optname)
2095 {
2096 case IP_TOS:
2097 if(val<0||val>255)
2098 return -EINVAL;
2099 sk->ip_tos=val;
2100 if(val==IPTOS_LOWDELAY)
2101 sk->priority=SOPRI_INTERACTIVE;
2102 if(val==IPTOS_THROUGHPUT)
2103 sk->priority=SOPRI_BACKGROUND;
2104 return 0;
2105 case IP_TTL:
2106 if(val<1||val>255)
2107 return -EINVAL;
2108 sk->ip_ttl=val;
2109 return 0;
2110 #ifdef CONFIG_IP_MULTICAST
2111 #ifdef GCC_WORKS
2112 case IP_MULTICAST_TTL:
2113 {
2114 unsigned char ucval;
2115
2116 ucval=get_fs_byte((unsigned char *)optval);
2117 printk("MC TTL %d\n", ucval);
2118 if(ucval<1||ucval>255)
2119 return -EINVAL;
2120 sk->ip_mc_ttl=(int)ucval;
2121 return 0;
2122 }
2123 #endif
2124 case IP_MULTICAST_LOOP:
2125 {
2126 unsigned char ucval;
2127
2128 ucval=get_fs_byte((unsigned char *)optval);
2129 if(ucval!=0 && ucval!=1)
2130 return -EINVAL;
2131 sk->ip_mc_loop=(int)ucval;
2132 return 0;
2133 }
2134 case IP_MULTICAST_IF:
2135 {
2136 /* Not fully tested */
2137 struct in_addr addr;
2138 struct device *dev=NULL;
2139
2140 /*
2141 * Check the arguments are allowable
2142 */
2143
2144 err=verify_area(VERIFY_READ, optval, sizeof(addr));
2145 if(err)
2146 return err;
2147
2148 memcpy_fromfs(&addr,optval,sizeof(addr));
2149
2150 printk("MC bind %s\n", in_ntoa(addr.s_addr));
2151
2152 /*
2153 * What address has been requested
2154 */
2155
2156 if(addr.s_addr==INADDR_ANY) /* Default */
2157 {
2158 sk->ip_mc_name[0]=0;
2159 return 0;
2160 }
2161
2162 /*
2163 * Find the device
2164 */
2165
2166 for(dev = dev_base; dev; dev = dev->next)
2167 {
2168 if((dev->flags&IFF_UP)&&(dev->flags&IFF_MULTICAST)&&
2169 (dev->pa_addr==addr.s_addr))
2170 break;
2171 }
2172
2173 /*
2174 * Did we find one
2175 */
2176
2177 if(dev)
2178 {
2179 strcpy(sk->ip_mc_name,dev->name);
2180 return 0;
2181 }
2182 return -EADDRNOTAVAIL;
2183 }
2184
2185 case IP_ADD_MEMBERSHIP:
2186 {
2187
2188 /*
2189 * FIXME: Add/Del membership should have a semaphore protecting them from re-entry
2190 */
2191 struct ip_mreq mreq;
2192 static struct options optmem;
2193 unsigned long route_src;
2194 struct rtable *rt;
2195 struct device *dev=NULL;
2196
2197 /*
2198 * Check the arguments.
2199 */
2200
2201 err=verify_area(VERIFY_READ, optval, sizeof(mreq));
2202 if(err)
2203 return err;
2204
2205 memcpy_fromfs(&mreq,optval,sizeof(mreq));
2206
2207 /*
2208 * Get device for use later
2209 */
2210
2211 if(mreq.imr_interface.s_addr==INADDR_ANY)
2212 {
2213 /*
2214 * Not set so scan.
2215 */
2216 if((rt=ip_rt_route(mreq.imr_multiaddr.s_addr,&optmem, &route_src))!=NULL)
2217 {
2218 dev=rt->rt_dev;
2219 rt->rt_use--;
2220 }
2221 }
2222 else
2223 {
2224 /*
2225 * Find a suitable device.
2226 */
2227 for(dev = dev_base; dev; dev = dev->next)
2228 {
2229 if((dev->flags&IFF_UP)&&(dev->flags&IFF_MULTICAST)&&
2230 (dev->pa_addr==mreq.imr_interface.s_addr))
2231 break;
2232 }
2233 }
2234
2235 /*
2236 * No device, no cookies.
2237 */
2238
2239 if(!dev)
2240 return -ENODEV;
2241
2242 /*
2243 * Join group.
2244 */
2245
2246 return ip_mc_join_group(sk,dev,mreq.imr_multiaddr.s_addr);
2247 }
2248
2249 case IP_DROP_MEMBERSHIP:
2250 {
2251 struct ip_mreq mreq;
2252 struct rtable *rt;
2253 static struct options optmem;
2254 unsigned long route_src;
2255 struct device *dev=NULL;
2256
2257 /*
2258 * Check the arguments
2259 */
2260
2261 err=verify_area(VERIFY_READ, optval, sizeof(mreq));
2262 if(err)
2263 return err;
2264
2265 memcpy_fromfs(&mreq,optval,sizeof(mreq));
2266
2267 /*
2268 * Get device for use later
2269 */
2270
2271 if(mreq.imr_interface.s_addr==INADDR_ANY)
2272 {
2273 if((rt=ip_rt_route(mreq.imr_multiaddr.s_addr,&optmem, &route_src))!=NULL)
2274 {
2275 dev=rt->rt_dev;
2276 rt->rt_use--;
2277 }
2278 }
2279 else
2280 {
2281 for(dev = dev_base; dev; dev = dev->next)
2282 {
2283 if((dev->flags&IFF_UP)&& (dev->flags&IFF_MULTICAST)&&
2284 (dev->pa_addr==mreq.imr_interface.s_addr))
2285 break;
2286 }
2287 }
2288
2289 /*
2290 * Did we find a suitable device.
2291 */
2292
2293 if(!dev)
2294 return -ENODEV;
2295
2296 /*
2297 * Leave group
2298 */
2299
2300 return ip_mc_leave_group(sk,dev,mreq.imr_multiaddr.s_addr);
2301 }
2302 #endif
2303 #ifdef CONFIG_IP_FIREWALL
2304 case IP_FW_ADD_BLK:
2305 case IP_FW_DEL_BLK:
2306 case IP_FW_ADD_FWD:
2307 case IP_FW_DEL_FWD:
2308 case IP_FW_CHK_BLK:
2309 case IP_FW_CHK_FWD:
2310 case IP_FW_FLUSH:
2311 case IP_FW_POLICY:
2312 if(!suser())
2313 return -EPERM;
2314 if(optlen>sizeof(tmp_fw) || optlen<1)
2315 return -EINVAL;
2316 err=verify_area(VERIFY_READ,optval,optlen);
2317 if(err)
2318 return err;
2319 memcpy_fromfs(&tmp_fw,optval,optlen);
2320 err=ip_fw_ctl(optname, &tmp_fw,optlen);
2321 return -err; /* -0 is 0 after all */
2322
2323 #endif
2324 #ifdef CONFIG_IP_ACCT
2325 case IP_ACCT_DEL:
2326 case IP_ACCT_ADD:
2327 case IP_ACCT_FLUSH:
2328 case IP_ACCT_ZERO:
2329 if(!suser())
2330 return -EPERM;
2331 if(optlen>sizeof(tmp_fw) || optlen<1)
2332 return -EINVAL;
2333 err=verify_area(VERIFY_READ,optval,optlen);
2334 if(err)
2335 return err;
2336 memcpy_fromfs(&tmp_fw, optval,optlen);
2337 err=ip_acct_ctl(optname, &tmp_fw,optlen);
2338 return -err; /* -0 is 0 after all */
2339 #endif
2340 /* IP_OPTIONS and friends go here eventually */
2341 default:
2342 return(-ENOPROTOOPT);
2343 }
2344 }
2345
2346 /*
2347 * Get the options. Note for future reference. The GET of IP options gets the
2348 * _received_ ones. The set sets the _sent_ ones.
2349 */
2350
2351 int ip_getsockopt(struct sock *sk, int level, int optname, char *optval, int *optlen)
/* */
2352 {
2353 int val,err;
2354 #ifdef CONFIG_IP_MULTICAST
2355 int len;
2356 #endif
2357
2358 if(level!=SOL_IP)
2359 return -EOPNOTSUPP;
2360
2361 switch(optname)
2362 {
2363 case IP_TOS:
2364 val=sk->ip_tos;
2365 break;
2366 case IP_TTL:
2367 val=sk->ip_ttl;
2368 break;
2369 #ifdef CONFIG_IP_MULTICAST
2370 case IP_MULTICAST_TTL:
2371 val=sk->ip_mc_ttl;
2372 break;
2373 case IP_MULTICAST_LOOP:
2374 val=sk->ip_mc_loop;
2375 break;
2376 case IP_MULTICAST_IF:
2377 err=verify_area(VERIFY_WRITE, optlen, sizeof(int));
2378 if(err)
2379 return err;
2380 len=strlen(sk->ip_mc_name);
2381 err=verify_area(VERIFY_WRITE, optval, len);
2382 if(err)
2383 return err;
2384 put_fs_long(len,(unsigned long *) optlen);
2385 memcpy_tofs((void *)optval,sk->ip_mc_name, len);
2386 return 0;
2387 #endif
2388 default:
2389 return(-ENOPROTOOPT);
2390 }
2391 err=verify_area(VERIFY_WRITE, optlen, sizeof(int));
2392 if(err)
2393 return err;
2394 put_fs_long(sizeof(int),(unsigned long *) optlen);
2395
2396 err=verify_area(VERIFY_WRITE, optval, sizeof(int));
2397 if(err)
2398 return err;
2399 put_fs_long(val,(unsigned long *)optval);
2400
2401 return(0);
2402 }
2403
2404 /*
2405 * IP protocol layer initialiser
2406 */
2407
2408 static struct packet_type ip_packet_type =
2409 {
2410 0, /* MUTTER ntohs(ETH_P_IP),*/
2411 NULL, /* All devices */
2412 ip_rcv,
2413 NULL,
2414 NULL,
2415 };
2416
2417 /*
2418 * Device notifier
2419 */
2420
2421 static int ip_rt_event(unsigned long event, void *ptr)
/* */
2422 {
2423 if(event==NETDEV_DOWN)
2424 ip_rt_flush(ptr);
2425 return NOTIFY_DONE;
2426 }
2427
2428 struct notifier_block ip_rt_notifier={
2429 ip_rt_event,
2430 NULL,
2431 0
2432 };
2433
2434 /*
2435 * IP registers the packet type and then calls the subprotocol initialisers
2436 */
2437
2438 void ip_init(void)
/* ![[last]](../icons/n_last.png)
*/
2439 {
2440 ip_packet_type.type=htons(ETH_P_IP);
2441 dev_add_pack(&ip_packet_type);
2442
2443 /* So we flush routes when a device is downed */
2444 register_netdevice_notifier(&ip_rt_notifier);
2445 /* ip_raw_init();
2446 ip_packet_init();
2447 ip_tcp_init();
2448 ip_udp_init();*/
2449 }
![[bottom]](../icons/n_bottom.png){kind=icon}
*/