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[IPV4/6]: Fix UFO error propagation
[linux-2.6.22.y-op.git] / net / ipv4 / ip_output.c
blob8ee4d016740d925f3781b8fc7842c99ed2145c27
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) output module.
7 *
8 * Version: $Id: ip_output.c,v 1.100 2002/02/01 22:01:03 davem Exp $
9 *
10 * Authors: Ross Biro
11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12 * Donald Becker, <becker@super.org>
13 * Alan Cox, <Alan.Cox@linux.org>
14 * Richard Underwood
15 * Stefan Becker, <stefanb@yello.ping.de>
16 * Jorge Cwik, <jorge@laser.satlink.net>
17 * Arnt Gulbrandsen, <agulbra@nvg.unit.no>
18 * Hirokazu Takahashi, <taka@valinux.co.jp>
19 *
20 * See ip_input.c for original log
21 *
22 * Fixes:
23 * Alan Cox : Missing nonblock feature in ip_build_xmit.
24 * Mike Kilburn : htons() missing in ip_build_xmit.
25 * Bradford Johnson: Fix faulty handling of some frames when
26 * no route is found.
27 * Alexander Demenshin: Missing sk/skb free in ip_queue_xmit
28 * (in case if packet not accepted by
29 * output firewall rules)
30 * Mike McLagan : Routing by source
31 * Alexey Kuznetsov: use new route cache
32 * Andi Kleen: Fix broken PMTU recovery and remove
33 * some redundant tests.
34 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
35 * Andi Kleen : Replace ip_reply with ip_send_reply.
36 * Andi Kleen : Split fast and slow ip_build_xmit path
37 * for decreased register pressure on x86
38 * and more readibility.
39 * Marc Boucher : When call_out_firewall returns FW_QUEUE,
40 * silently drop skb instead of failing with -EPERM.
41 * Detlev Wengorz : Copy protocol for fragments.
42 * Hirokazu Takahashi: HW checksumming for outgoing UDP
43 * datagrams.
44 * Hirokazu Takahashi: sendfile() on UDP works now.
45 */
46
47 #include <asm/uaccess.h>
48 #include <asm/system.h>
49 #include <linux/module.h>
50 #include <linux/types.h>
51 #include <linux/kernel.h>
52 #include <linux/sched.h>
53 #include <linux/mm.h>
54 #include <linux/string.h>
55 #include <linux/errno.h>
56 #include <linux/config.h>
57
58 #include <linux/socket.h>
59 #include <linux/sockios.h>
60 #include <linux/in.h>
61 #include <linux/inet.h>
62 #include <linux/netdevice.h>
63 #include <linux/etherdevice.h>
64 #include <linux/proc_fs.h>
65 #include <linux/stat.h>
66 #include <linux/init.h>
67
68 #include <net/snmp.h>
69 #include <net/ip.h>
70 #include <net/protocol.h>
71 #include <net/route.h>
72 #include <net/xfrm.h>
73 #include <linux/skbuff.h>
74 #include <net/sock.h>
75 #include <net/arp.h>
76 #include <net/icmp.h>
77 #include <net/checksum.h>
78 #include <net/inetpeer.h>
79 #include <net/checksum.h>
80 #include <linux/igmp.h>
81 #include <linux/netfilter_ipv4.h>
82 #include <linux/netfilter_bridge.h>
83 #include <linux/mroute.h>
84 #include <linux/netlink.h>
85 #include <linux/tcp.h>
86
87 int sysctl_ip_default_ttl = IPDEFTTL;
88
89 static int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff*));
90
91 /* Generate a checksum for an outgoing IP datagram. */
92 __inline__ void ip_send_check(struct iphdr *iph)
93 {
94 iph->check = 0;
95 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
96 }
97
98 /* dev_loopback_xmit for use with netfilter. */
99 static int ip_dev_loopback_xmit(struct sk_buff *newskb)
100 {
101 newskb->mac.raw = newskb->data;
102 __skb_pull(newskb, newskb->nh.raw - newskb->data);
103 newskb->pkt_type = PACKET_LOOPBACK;
104 newskb->ip_summed = CHECKSUM_UNNECESSARY;
105 BUG_TRAP(newskb->dst);
106 netif_rx(newskb);
107 return 0;
108 }
109
110 static inline int ip_select_ttl(struct inet_sock *inet, struct dst_entry *dst)
111 {
112 int ttl = inet->uc_ttl;
113
114 if (ttl < 0)
115 ttl = dst_metric(dst, RTAX_HOPLIMIT);
116 return ttl;
117 }
118
119 /*
120 * Add an ip header to a skbuff and send it out.
121 *
122 */
123 int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk,
124 u32 saddr, u32 daddr, struct ip_options *opt)
125 {
126 struct inet_sock *inet = inet_sk(sk);
127 struct rtable *rt = (struct rtable *)skb->dst;
128 struct iphdr *iph;
129
130 /* Build the IP header. */
131 if (opt)
132 iph=(struct iphdr *)skb_push(skb,sizeof(struct iphdr) + opt->optlen);
133 else
134 iph=(struct iphdr *)skb_push(skb,sizeof(struct iphdr));
135
136 iph->version = 4;
137 iph->ihl = 5;
138 iph->tos = inet->tos;
139 if (ip_dont_fragment(sk, &rt->u.dst))
140 iph->frag_off = htons(IP_DF);
141 else
142 iph->frag_off = 0;
143 iph->ttl = ip_select_ttl(inet, &rt->u.dst);
144 iph->daddr = rt->rt_dst;
145 iph->saddr = rt->rt_src;
146 iph->protocol = sk->sk_protocol;
147 iph->tot_len = htons(skb->len);
148 ip_select_ident(iph, &rt->u.dst, sk);
149 skb->nh.iph = iph;
150
151 if (opt && opt->optlen) {
152 iph->ihl += opt->optlen>>2;
153 ip_options_build(skb, opt, daddr, rt, 0);
154 }
155 ip_send_check(iph);
156
157 skb->priority = sk->sk_priority;
158
159 /* Send it out. */
160 return NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, skb, NULL, rt->u.dst.dev,
161 dst_output);
162 }
163
164 EXPORT_SYMBOL_GPL(ip_build_and_send_pkt);
165
166 static inline int ip_finish_output2(struct sk_buff *skb)
167 {
168 struct dst_entry *dst = skb->dst;
169 struct hh_cache *hh = dst->hh;
170 struct net_device *dev = dst->dev;
171 int hh_len = LL_RESERVED_SPACE(dev);
172
173 /* Be paranoid, rather than too clever. */
174 if (unlikely(skb_headroom(skb) < hh_len && dev->hard_header)) {
175 struct sk_buff *skb2;
176
177 skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev));
178 if (skb2 == NULL) {
179 kfree_skb(skb);
180 return -ENOMEM;
181 }
182 if (skb->sk)
183 skb_set_owner_w(skb2, skb->sk);
184 kfree_skb(skb);
185 skb = skb2;
186 }
187
188 if (hh) {
189 int hh_alen;
190
191 read_lock_bh(&hh->hh_lock);
192 hh_alen = HH_DATA_ALIGN(hh->hh_len);
193 memcpy(skb->data - hh_alen, hh->hh_data, hh_alen);
194 read_unlock_bh(&hh->hh_lock);
195 skb_push(skb, hh->hh_len);
196 return hh->hh_output(skb);
197 } else if (dst->neighbour)
198 return dst->neighbour->output(skb);
199
200 if (net_ratelimit())
201 printk(KERN_DEBUG "ip_finish_output2: No header cache and no neighbour!\n");
202 kfree_skb(skb);
203 return -EINVAL;
204 }
205
206 static inline int ip_finish_output(struct sk_buff *skb)
207 {
208 #if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM)
209 /* Policy lookup after SNAT yielded a new policy */
210 if (skb->dst->xfrm != NULL) {
211 IPCB(skb)->flags |= IPSKB_REROUTED;
212 return dst_output(skb);
213 }
214 #endif
215 if (skb->len > dst_mtu(skb->dst) &&
216 !(skb_shinfo(skb)->ufo_size || skb_shinfo(skb)->tso_size))
217 return ip_fragment(skb, ip_finish_output2);
218 else
219 return ip_finish_output2(skb);
220 }
221
222 int ip_mc_output(struct sk_buff *skb)
223 {
224 struct sock *sk = skb->sk;
225 struct rtable *rt = (struct rtable*)skb->dst;
226 struct net_device *dev = rt->u.dst.dev;
227
228 /*
229 * If the indicated interface is up and running, send the packet.
230 */
231 IP_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
232
233 skb->dev = dev;
234 skb->protocol = htons(ETH_P_IP);
235
236 /*
237 * Multicasts are looped back for other local users
238 */
239
240 if (rt->rt_flags&RTCF_MULTICAST) {
241 if ((!sk || inet_sk(sk)->mc_loop)
242 #ifdef CONFIG_IP_MROUTE
243 /* Small optimization: do not loopback not local frames,
244 which returned after forwarding; they will be dropped
245 by ip_mr_input in any case.
246 Note, that local frames are looped back to be delivered
247 to local recipients.
248
249 This check is duplicated in ip_mr_input at the moment.
250 */
251 && ((rt->rt_flags&RTCF_LOCAL) || !(IPCB(skb)->flags&IPSKB_FORWARDED))
252 #endif
253 ) {
254 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
255 if (newskb)
256 NF_HOOK(PF_INET, NF_IP_POST_ROUTING, newskb, NULL,
257 newskb->dev,
258 ip_dev_loopback_xmit);
259 }
260
261 /* Multicasts with ttl 0 must not go beyond the host */
262
263 if (skb->nh.iph->ttl == 0) {
264 kfree_skb(skb);
265 return 0;
266 }
267 }
268
269 if (rt->rt_flags&RTCF_BROADCAST) {
270 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
271 if (newskb)
272 NF_HOOK(PF_INET, NF_IP_POST_ROUTING, newskb, NULL,
273 newskb->dev, ip_dev_loopback_xmit);
274 }
275
276 return NF_HOOK_COND(PF_INET, NF_IP_POST_ROUTING, skb, NULL, skb->dev,
277 ip_finish_output,
278 !(IPCB(skb)->flags & IPSKB_REROUTED));
279 }
280
281 int ip_output(struct sk_buff *skb)
282 {
283 struct net_device *dev = skb->dst->dev;
284
285 IP_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
286
287 skb->dev = dev;
288 skb->protocol = htons(ETH_P_IP);
289
290 return NF_HOOK_COND(PF_INET, NF_IP_POST_ROUTING, skb, NULL, dev,
291 ip_finish_output,
292 !(IPCB(skb)->flags & IPSKB_REROUTED));
293 }
294
295 int ip_queue_xmit(struct sk_buff *skb, int ipfragok)
296 {
297 struct sock *sk = skb->sk;
298 struct inet_sock *inet = inet_sk(sk);
299 struct ip_options *opt = inet->opt;
300 struct rtable *rt;
301 struct iphdr *iph;
302
303 /* Skip all of this if the packet is already routed,
304 * f.e. by something like SCTP.
305 */
306 rt = (struct rtable *) skb->dst;
307 if (rt != NULL)
308 goto packet_routed;
309
310 /* Make sure we can route this packet. */
311 rt = (struct rtable *)__sk_dst_check(sk, 0);
312 if (rt == NULL) {
313 u32 daddr;
314
315 /* Use correct destination address if we have options. */
316 daddr = inet->daddr;
317 if(opt && opt->srr)
318 daddr = opt->faddr;
319
320 {
321 struct flowi fl = { .oif = sk->sk_bound_dev_if,
322 .nl_u = { .ip4_u =
323 { .daddr = daddr,
324 .saddr = inet->saddr,
325 .tos = RT_CONN_FLAGS(sk) } },
326 .proto = sk->sk_protocol,
327 .uli_u = { .ports =
328 { .sport = inet->sport,
329 .dport = inet->dport } } };
330
331 /* If this fails, retransmit mechanism of transport layer will
332 * keep trying until route appears or the connection times
333 * itself out.
334 */
335 if (ip_route_output_flow(&rt, &fl, sk, 0))
336 goto no_route;
337 }
338 sk_setup_caps(sk, &rt->u.dst);
339 }
340 skb->dst = dst_clone(&rt->u.dst);
341
342 packet_routed:
343 if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway)
344 goto no_route;
345
346 /* OK, we know where to send it, allocate and build IP header. */
347 iph = (struct iphdr *) skb_push(skb, sizeof(struct iphdr) + (opt ? opt->optlen : 0));
348 *((__u16 *)iph) = htons((4 << 12) | (5 << 8) | (inet->tos & 0xff));
349 iph->tot_len = htons(skb->len);
350 if (ip_dont_fragment(sk, &rt->u.dst) && !ipfragok)
351 iph->frag_off = htons(IP_DF);
352 else
353 iph->frag_off = 0;
354 iph->ttl = ip_select_ttl(inet, &rt->u.dst);
355 iph->protocol = sk->sk_protocol;
356 iph->saddr = rt->rt_src;
357 iph->daddr = rt->rt_dst;
358 skb->nh.iph = iph;
359 /* Transport layer set skb->h.foo itself. */
360
361 if (opt && opt->optlen) {
362 iph->ihl += opt->optlen >> 2;
363 ip_options_build(skb, opt, inet->daddr, rt, 0);
364 }
365
366 ip_select_ident_more(iph, &rt->u.dst, sk,
367 (skb_shinfo(skb)->tso_segs ?: 1) - 1);
368
369 /* Add an IP checksum. */
370 ip_send_check(iph);
371
372 skb->priority = sk->sk_priority;
373
374 return NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, skb, NULL, rt->u.dst.dev,
375 dst_output);
376
377 no_route:
378 IP_INC_STATS(IPSTATS_MIB_OUTNOROUTES);
379 kfree_skb(skb);
380 return -EHOSTUNREACH;
381 }
382
383
384 static void ip_copy_metadata(struct sk_buff *to, struct sk_buff *from)
385 {
386 to->pkt_type = from->pkt_type;
387 to->priority = from->priority;
388 to->protocol = from->protocol;
389 dst_release(to->dst);
390 to->dst = dst_clone(from->dst);
391 to->dev = from->dev;
392
393 /* Copy the flags to each fragment. */
394 IPCB(to)->flags = IPCB(from)->flags;
395
396 #ifdef CONFIG_NET_SCHED
397 to->tc_index = from->tc_index;
398 #endif
399 #ifdef CONFIG_NETFILTER
400 to->nfmark = from->nfmark;
401 /* Connection association is same as pre-frag packet */
402 nf_conntrack_put(to->nfct);
403 to->nfct = from->nfct;
404 nf_conntrack_get(to->nfct);
405 to->nfctinfo = from->nfctinfo;
406 #if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE)
407 to->ipvs_property = from->ipvs_property;
408 #endif
409 #ifdef CONFIG_BRIDGE_NETFILTER
410 nf_bridge_put(to->nf_bridge);
411 to->nf_bridge = from->nf_bridge;
412 nf_bridge_get(to->nf_bridge);
413 #endif
414 #endif
415 }
416
417 /*
418 * This IP datagram is too large to be sent in one piece. Break it up into
419 * smaller pieces (each of size equal to IP header plus
420 * a block of the data of the original IP data part) that will yet fit in a
421 * single device frame, and queue such a frame for sending.
422 */
423
424 static int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff*))
425 {
426 struct iphdr *iph;
427 int raw = 0;
428 int ptr;
429 struct net_device *dev;
430 struct sk_buff *skb2;
431 unsigned int mtu, hlen, left, len, ll_rs;
432 int offset;
433 __be16 not_last_frag;
434 struct rtable *rt = (struct rtable*)skb->dst;
435 int err = 0;
436
437 dev = rt->u.dst.dev;
438
439 /*
440 * Point into the IP datagram header.
441 */
442
443 iph = skb->nh.iph;
444
445 if (unlikely((iph->frag_off & htons(IP_DF)) && !skb->local_df)) {
446 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
447 htonl(dst_mtu(&rt->u.dst)));
448 kfree_skb(skb);
449 return -EMSGSIZE;
450 }
451
452 /*
453 * Setup starting values.
454 */
455
456 hlen = iph->ihl * 4;
457 mtu = dst_mtu(&rt->u.dst) - hlen; /* Size of data space */
458 IPCB(skb)->flags |= IPSKB_FRAG_COMPLETE;
459
460 /* When frag_list is given, use it. First, check its validity:
461 * some transformers could create wrong frag_list or break existing
462 * one, it is not prohibited. In this case fall back to copying.
463 *
464 * LATER: this step can be merged to real generation of fragments,
465 * we can switch to copy when see the first bad fragment.
466 */
467 if (skb_shinfo(skb)->frag_list) {
468 struct sk_buff *frag;
469 int first_len = skb_pagelen(skb);
470
471 if (first_len - hlen > mtu ||
472 ((first_len - hlen) & 7) ||
473 (iph->frag_off & htons(IP_MF|IP_OFFSET)) ||
474 skb_cloned(skb))
475 goto slow_path;
476
477 for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) {
478 /* Correct geometry. */
479 if (frag->len > mtu ||
480 ((frag->len & 7) && frag->next) ||
481 skb_headroom(frag) < hlen)
482 goto slow_path;
483
484 /* Partially cloned skb? */
485 if (skb_shared(frag))
486 goto slow_path;
487
488 BUG_ON(frag->sk);
489 if (skb->sk) {
490 sock_hold(skb->sk);
491 frag->sk = skb->sk;
492 frag->destructor = sock_wfree;
493 skb->truesize -= frag->truesize;
494 }
495 }
496
497 /* Everything is OK. Generate! */
498
499 err = 0;
500 offset = 0;
501 frag = skb_shinfo(skb)->frag_list;
502 skb_shinfo(skb)->frag_list = NULL;
503 skb->data_len = first_len - skb_headlen(skb);
504 skb->len = first_len;
505 iph->tot_len = htons(first_len);
506 iph->frag_off = htons(IP_MF);
507 ip_send_check(iph);
508
509 for (;;) {
510 /* Prepare header of the next frame,
511 * before previous one went down. */
512 if (frag) {
513 frag->ip_summed = CHECKSUM_NONE;
514 frag->h.raw = frag->data;
515 frag->nh.raw = __skb_push(frag, hlen);
516 memcpy(frag->nh.raw, iph, hlen);
517 iph = frag->nh.iph;
518 iph->tot_len = htons(frag->len);
519 ip_copy_metadata(frag, skb);
520 if (offset == 0)
521 ip_options_fragment(frag);
522 offset += skb->len - hlen;
523 iph->frag_off = htons(offset>>3);
524 if (frag->next != NULL)
525 iph->frag_off |= htons(IP_MF);
526 /* Ready, complete checksum */
527 ip_send_check(iph);
528 }
529
530 err = output(skb);
531
532 if (err || !frag)
533 break;
534
535 skb = frag;
536 frag = skb->next;
537 skb->next = NULL;
538 }
539
540 if (err == 0) {
541 IP_INC_STATS(IPSTATS_MIB_FRAGOKS);
542 return 0;
543 }
544
545 while (frag) {
546 skb = frag->next;
547 kfree_skb(frag);
548 frag = skb;
549 }
550 IP_INC_STATS(IPSTATS_MIB_FRAGFAILS);
551 return err;
552 }
553
554 slow_path:
555 left = skb->len - hlen; /* Space per frame */
556 ptr = raw + hlen; /* Where to start from */
557
558 #ifdef CONFIG_BRIDGE_NETFILTER
559 /* for bridged IP traffic encapsulated inside f.e. a vlan header,
560 * we need to make room for the encapsulating header */
561 ll_rs = LL_RESERVED_SPACE_EXTRA(rt->u.dst.dev, nf_bridge_pad(skb));
562 mtu -= nf_bridge_pad(skb);
563 #else
564 ll_rs = LL_RESERVED_SPACE(rt->u.dst.dev);
565 #endif
566 /*
567 * Fragment the datagram.
568 */
569
570 offset = (ntohs(iph->frag_off) & IP_OFFSET) << 3;
571 not_last_frag = iph->frag_off & htons(IP_MF);
572
573 /*
574 * Keep copying data until we run out.
575 */
576
577 while(left > 0) {
578 len = left;
579 /* IF: it doesn't fit, use 'mtu' - the data space left */
580 if (len > mtu)
581 len = mtu;
582 /* IF: we are not sending upto and including the packet end
583 then align the next start on an eight byte boundary */
584 if (len < left) {
585 len &= ~7;
586 }
587 /*
588 * Allocate buffer.
589 */
590
591 if ((skb2 = alloc_skb(len+hlen+ll_rs, GFP_ATOMIC)) == NULL) {
592 NETDEBUG(KERN_INFO "IP: frag: no memory for new fragment!\n");
593 err = -ENOMEM;
594 goto fail;
595 }
596
597 /*
598 * Set up data on packet
599 */
600
601 ip_copy_metadata(skb2, skb);
602 skb_reserve(skb2, ll_rs);
603 skb_put(skb2, len + hlen);
604 skb2->nh.raw = skb2->data;
605 skb2->h.raw = skb2->data + hlen;
606
607 /*
608 * Charge the memory for the fragment to any owner
609 * it might possess
610 */
611
612 if (skb->sk)
613 skb_set_owner_w(skb2, skb->sk);
614
615 /*
616 * Copy the packet header into the new buffer.
617 */
618
619 memcpy(skb2->nh.raw, skb->data, hlen);
620
621 /*
622 * Copy a block of the IP datagram.
623 */
624 if (skb_copy_bits(skb, ptr, skb2->h.raw, len))
625 BUG();
626 left -= len;
627
628 /*
629 * Fill in the new header fields.
630 */
631 iph = skb2->nh.iph;
632 iph->frag_off = htons((offset >> 3));
633
634 /* ANK: dirty, but effective trick. Upgrade options only if
635 * the segment to be fragmented was THE FIRST (otherwise,
636 * options are already fixed) and make it ONCE
637 * on the initial skb, so that all the following fragments
638 * will inherit fixed options.
639 */
640 if (offset == 0)
641 ip_options_fragment(skb);
642
643 /*
644 * Added AC : If we are fragmenting a fragment that's not the
645 * last fragment then keep MF on each bit
646 */
647 if (left > 0 || not_last_frag)
648 iph->frag_off |= htons(IP_MF);
649 ptr += len;
650 offset += len;
651
652 /*
653 * Put this fragment into the sending queue.
654 */
655
656 IP_INC_STATS(IPSTATS_MIB_FRAGCREATES);
657
658 iph->tot_len = htons(len + hlen);
659
660 ip_send_check(iph);
661
662 err = output(skb2);
663 if (err)
664 goto fail;
665 }
666 kfree_skb(skb);
667 IP_INC_STATS(IPSTATS_MIB_FRAGOKS);
668 return err;
669
670 fail:
671 kfree_skb(skb);
672 IP_INC_STATS(IPSTATS_MIB_FRAGFAILS);
673 return err;
674 }
675
676 int
677 ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb)
678 {
679 struct iovec *iov = from;
680
681 if (skb->ip_summed == CHECKSUM_HW) {
682 if (memcpy_fromiovecend(to, iov, offset, len) < 0)
683 return -EFAULT;
684 } else {
685 unsigned int csum = 0;
686 if (csum_partial_copy_fromiovecend(to, iov, offset, len, &csum) < 0)
687 return -EFAULT;
688 skb->csum = csum_block_add(skb->csum, csum, odd);
689 }
690 return 0;
691 }
692
693 static inline unsigned int
694 csum_page(struct page *page, int offset, int copy)
695 {
696 char *kaddr;
697 unsigned int csum;
698 kaddr = kmap(page);
699 csum = csum_partial(kaddr + offset, copy, 0);
700 kunmap(page);
701 return csum;
702 }
703
704 static inline int ip_ufo_append_data(struct sock *sk,
705 int getfrag(void *from, char *to, int offset, int len,
706 int odd, struct sk_buff *skb),
707 void *from, int length, int hh_len, int fragheaderlen,
708 int transhdrlen, int mtu,unsigned int flags)
709 {
710 struct sk_buff *skb;
711 int err;
712
713 /* There is support for UDP fragmentation offload by network
714 * device, so create one single skb packet containing complete
715 * udp datagram
716 */
717 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) {
718 skb = sock_alloc_send_skb(sk,
719 hh_len + fragheaderlen + transhdrlen + 20,
720 (flags & MSG_DONTWAIT), &err);
721
722 if (skb == NULL)
723 return err;
724
725 /* reserve space for Hardware header */
726 skb_reserve(skb, hh_len);
727
728 /* create space for UDP/IP header */
729 skb_put(skb,fragheaderlen + transhdrlen);
730
731 /* initialize network header pointer */
732 skb->nh.raw = skb->data;
733
734 /* initialize protocol header pointer */
735 skb->h.raw = skb->data + fragheaderlen;
736
737 skb->ip_summed = CHECKSUM_HW;
738 skb->csum = 0;
739 sk->sk_sndmsg_off = 0;
740 }
741
742 err = skb_append_datato_frags(sk,skb, getfrag, from,
743 (length - transhdrlen));
744 if (!err) {
745 /* specify the length of each IP datagram fragment*/
746 skb_shinfo(skb)->ufo_size = (mtu - fragheaderlen);
747 __skb_queue_tail(&sk->sk_write_queue, skb);
748
749 return 0;
750 }
751 /* There is not enough support do UFO ,
752 * so follow normal path
753 */
754 kfree_skb(skb);
755 return err;
756 }
757
758 /*
759 * ip_append_data() and ip_append_page() can make one large IP datagram
760 * from many pieces of data. Each pieces will be holded on the socket
761 * until ip_push_pending_frames() is called. Each piece can be a page
762 * or non-page data.
763 *
764 * Not only UDP, other transport protocols - e.g. raw sockets - can use
765 * this interface potentially.
766 *
767 * LATER: length must be adjusted by pad at tail, when it is required.
768 */
769 int ip_append_data(struct sock *sk,
770 int getfrag(void *from, char *to, int offset, int len,
771 int odd, struct sk_buff *skb),
772 void *from, int length, int transhdrlen,
773 struct ipcm_cookie *ipc, struct rtable *rt,
774 unsigned int flags)
775 {
776 struct inet_sock *inet = inet_sk(sk);
777 struct sk_buff *skb;
778
779 struct ip_options *opt = NULL;
780 int hh_len;
781 int exthdrlen;
782 int mtu;
783 int copy;
784 int err;
785 int offset = 0;
786 unsigned int maxfraglen, fragheaderlen;
787 int csummode = CHECKSUM_NONE;
788
789 if (flags&MSG_PROBE)
790 return 0;
791
792 if (skb_queue_empty(&sk->sk_write_queue)) {
793 /*
794 * setup for corking.
795 */
796 opt = ipc->opt;
797 if (opt) {
798 if (inet->cork.opt == NULL) {
799 inet->cork.opt = kmalloc(sizeof(struct ip_options) + 40, sk->sk_allocation);
800 if (unlikely(inet->cork.opt == NULL))
801 return -ENOBUFS;
802 }
803 memcpy(inet->cork.opt, opt, sizeof(struct ip_options)+opt->optlen);
804 inet->cork.flags |= IPCORK_OPT;
805 inet->cork.addr = ipc->addr;
806 }
807 dst_hold(&rt->u.dst);
808 inet->cork.fragsize = mtu = dst_mtu(rt->u.dst.path);
809 inet->cork.rt = rt;
810 inet->cork.length = 0;
811 sk->sk_sndmsg_page = NULL;
812 sk->sk_sndmsg_off = 0;
813 if ((exthdrlen = rt->u.dst.header_len) != 0) {
814 length += exthdrlen;
815 transhdrlen += exthdrlen;
816 }
817 } else {
818 rt = inet->cork.rt;
819 if (inet->cork.flags & IPCORK_OPT)
820 opt = inet->cork.opt;
821
822 transhdrlen = 0;
823 exthdrlen = 0;
824 mtu = inet->cork.fragsize;
825 }
826 hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);
827
828 fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0);
829 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen;
830
831 if (inet->cork.length + length > 0xFFFF - fragheaderlen) {
832 ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->dport, mtu-exthdrlen);
833 return -EMSGSIZE;
834 }
835
836 /*
837 * transhdrlen > 0 means that this is the first fragment and we wish
838 * it won't be fragmented in the future.
839 */
840 if (transhdrlen &&
841 length + fragheaderlen <= mtu &&
842 rt->u.dst.dev->features&(NETIF_F_IP_CSUM|NETIF_F_NO_CSUM|NETIF_F_HW_CSUM) &&
843 !exthdrlen)
844 csummode = CHECKSUM_HW;
845
846 inet->cork.length += length;
847 if (((length > mtu) && (sk->sk_protocol == IPPROTO_UDP)) &&
848 (rt->u.dst.dev->features & NETIF_F_UFO)) {
849
850 err = ip_ufo_append_data(sk, getfrag, from, length, hh_len,
851 fragheaderlen, transhdrlen, mtu,
852 flags);
853 if (err)
854 goto error;
855 return 0;
856 }
857
858 /* So, what's going on in the loop below?
859 *
860 * We use calculated fragment length to generate chained skb,
861 * each of segments is IP fragment ready for sending to network after
862 * adding appropriate IP header.
863 */
864
865 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL)
866 goto alloc_new_skb;
867
868 while (length > 0) {
869 /* Check if the remaining data fits into current packet. */
870 copy = mtu - skb->len;
871 if (copy < length)
872 copy = maxfraglen - skb->len;
873 if (copy <= 0) {
874 char *data;
875 unsigned int datalen;
876 unsigned int fraglen;
877 unsigned int fraggap;
878 unsigned int alloclen;
879 struct sk_buff *skb_prev;
880 alloc_new_skb:
881 skb_prev = skb;
882 if (skb_prev)
883 fraggap = skb_prev->len - maxfraglen;
884 else
885 fraggap = 0;
886
887 /*
888 * If remaining data exceeds the mtu,
889 * we know we need more fragment(s).
890 */
891 datalen = length + fraggap;
892 if (datalen > mtu - fragheaderlen)
893 datalen = maxfraglen - fragheaderlen;
894 fraglen = datalen + fragheaderlen;
895
896 if ((flags & MSG_MORE) &&
897 !(rt->u.dst.dev->features&NETIF_F_SG))
898 alloclen = mtu;
899 else
900 alloclen = datalen + fragheaderlen;
901
902 /* The last fragment gets additional space at tail.
903 * Note, with MSG_MORE we overallocate on fragments,
904 * because we have no idea what fragment will be
905 * the last.
906 */
907 if (datalen == length)
908 alloclen += rt->u.dst.trailer_len;
909
910 if (transhdrlen) {
911 skb = sock_alloc_send_skb(sk,
912 alloclen + hh_len + 15,
913 (flags & MSG_DONTWAIT), &err);
914 } else {
915 skb = NULL;
916 if (atomic_read(&sk->sk_wmem_alloc) <=
917 2 * sk->sk_sndbuf)
918 skb = sock_wmalloc(sk,
919 alloclen + hh_len + 15, 1,
920 sk->sk_allocation);
921 if (unlikely(skb == NULL))
922 err = -ENOBUFS;
923 }
924 if (skb == NULL)
925 goto error;
926
927 /*
928 * Fill in the control structures
929 */
930 skb->ip_summed = csummode;
931 skb->csum = 0;
932 skb_reserve(skb, hh_len);
933
934 /*
935 * Find where to start putting bytes.
936 */
937 data = skb_put(skb, fraglen);
938 skb->nh.raw = data + exthdrlen;
939 data += fragheaderlen;
940 skb->h.raw = data + exthdrlen;
941
942 if (fraggap) {
943 skb->csum = skb_copy_and_csum_bits(
944 skb_prev, maxfraglen,
945 data + transhdrlen, fraggap, 0);
946 skb_prev->csum = csum_sub(skb_prev->csum,
947 skb->csum);
948 data += fraggap;
949 skb_trim(skb_prev, maxfraglen);
950 }
951
952 copy = datalen - transhdrlen - fraggap;
953 if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) {
954 err = -EFAULT;
955 kfree_skb(skb);
956 goto error;
957 }
958
959 offset += copy;
960 length -= datalen - fraggap;
961 transhdrlen = 0;
962 exthdrlen = 0;
963 csummode = CHECKSUM_NONE;
964
965 /*
966 * Put the packet on the pending queue.
967 */
968 __skb_queue_tail(&sk->sk_write_queue, skb);
969 continue;
970 }
971
972 if (copy > length)
973 copy = length;
974
975 if (!(rt->u.dst.dev->features&NETIF_F_SG)) {
976 unsigned int off;
977
978 off = skb->len;
979 if (getfrag(from, skb_put(skb, copy),
980 offset, copy, off, skb) < 0) {
981 __skb_trim(skb, off);
982 err = -EFAULT;
983 goto error;
984 }
985 } else {
986 int i = skb_shinfo(skb)->nr_frags;
987 skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1];
988 struct page *page = sk->sk_sndmsg_page;
989 int off = sk->sk_sndmsg_off;
990 unsigned int left;
991
992 if (page && (left = PAGE_SIZE - off) > 0) {
993 if (copy >= left)
994 copy = left;
995 if (page != frag->page) {
996 if (i == MAX_SKB_FRAGS) {
997 err = -EMSGSIZE;
998 goto error;
999 }
1000 get_page(page);
1001 skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0);
1002 frag = &skb_shinfo(skb)->frags[i];
1003 }
1004 } else if (i < MAX_SKB_FRAGS) {
1005 if (copy > PAGE_SIZE)
1006 copy = PAGE_SIZE;
1007 page = alloc_pages(sk->sk_allocation, 0);
1008 if (page == NULL) {
1009 err = -ENOMEM;
1010 goto error;
1011 }
1012 sk->sk_sndmsg_page = page;
1013 sk->sk_sndmsg_off = 0;
1014
1015 skb_fill_page_desc(skb, i, page, 0, 0);
1016 frag = &skb_shinfo(skb)->frags[i];
1017 skb->truesize += PAGE_SIZE;
1018 atomic_add(PAGE_SIZE, &sk->sk_wmem_alloc);
1019 } else {
1020 err = -EMSGSIZE;
1021 goto error;
1022 }
1023 if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) {
1024 err = -EFAULT;
1025 goto error;
1026 }
1027 sk->sk_sndmsg_off += copy;
1028 frag->size += copy;
1029 skb->len += copy;
1030 skb->data_len += copy;
1031 }
1032 offset += copy;
1033 length -= copy;
1034 }
1035
1036 return 0;
1037
1038 error:
1039 inet->cork.length -= length;
1040 IP_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
1041 return err;
1042 }
1043
1044 ssize_t ip_append_page(struct sock *sk, struct page *page,
1045 int offset, size_t size, int flags)
1046 {
1047 struct inet_sock *inet = inet_sk(sk);
1048 struct sk_buff *skb;
1049 struct rtable *rt;
1050 struct ip_options *opt = NULL;
1051 int hh_len;
1052 int mtu;
1053 int len;
1054 int err;
1055 unsigned int maxfraglen, fragheaderlen, fraggap;
1056
1057 if (inet->hdrincl)
1058 return -EPERM;
1059
1060 if (flags&MSG_PROBE)
1061 return 0;
1062
1063 if (skb_queue_empty(&sk->sk_write_queue))
1064 return -EINVAL;
1065
1066 rt = inet->cork.rt;
1067 if (inet->cork.flags & IPCORK_OPT)
1068 opt = inet->cork.opt;
1069
1070 if (!(rt->u.dst.dev->features&NETIF_F_SG))
1071 return -EOPNOTSUPP;
1072
1073 hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);
1074 mtu = inet->cork.fragsize;
1075
1076 fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0);
1077 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen;
1078
1079 if (inet->cork.length + size > 0xFFFF - fragheaderlen) {
1080 ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->dport, mtu);
1081 return -EMSGSIZE;
1082 }
1083
1084 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL)
1085 return -EINVAL;
1086
1087 inet->cork.length += size;
1088 if ((sk->sk_protocol == IPPROTO_UDP) &&
1089 (rt->u.dst.dev->features & NETIF_F_UFO))
1090 skb_shinfo(skb)->ufo_size = (mtu - fragheaderlen);
1091
1092
1093 while (size > 0) {
1094 int i;
1095
1096 if (skb_shinfo(skb)->ufo_size)
1097 len = size;
1098 else {
1099
1100 /* Check if the remaining data fits into current packet. */
1101 len = mtu - skb->len;
1102 if (len < size)
1103 len = maxfraglen - skb->len;
1104 }
1105 if (len <= 0) {
1106 struct sk_buff *skb_prev;
1107 char *data;
1108 struct iphdr *iph;
1109 int alloclen;
1110
1111 skb_prev = skb;
1112 fraggap = skb_prev->len - maxfraglen;
1113
1114 alloclen = fragheaderlen + hh_len + fraggap + 15;
1115 skb = sock_wmalloc(sk, alloclen, 1, sk->sk_allocation);
1116 if (unlikely(!skb)) {
1117 err = -ENOBUFS;
1118 goto error;
1119 }
1120
1121 /*
1122 * Fill in the control structures
1123 */
1124 skb->ip_summed = CHECKSUM_NONE;
1125 skb->csum = 0;
1126 skb_reserve(skb, hh_len);
1127
1128 /*
1129 * Find where to start putting bytes.
1130 */
1131 data = skb_put(skb, fragheaderlen + fraggap);
1132 skb->nh.iph = iph = (struct iphdr *)data;
1133 data += fragheaderlen;
1134 skb->h.raw = data;
1135
1136 if (fraggap) {
1137 skb->csum = skb_copy_and_csum_bits(
1138 skb_prev, maxfraglen,
1139 data, fraggap, 0);
1140 skb_prev->csum = csum_sub(skb_prev->csum,
1141 skb->csum);
1142 skb_trim(skb_prev, maxfraglen);
1143 }
1144
1145 /*
1146 * Put the packet on the pending queue.
1147 */
1148 __skb_queue_tail(&sk->sk_write_queue, skb);
1149 continue;
1150 }
1151
1152 i = skb_shinfo(skb)->nr_frags;
1153 if (len > size)
1154 len = size;
1155 if (skb_can_coalesce(skb, i, page, offset)) {
1156 skb_shinfo(skb)->frags[i-1].size += len;
1157 } else if (i < MAX_SKB_FRAGS) {
1158 get_page(page);
1159 skb_fill_page_desc(skb, i, page, offset, len);
1160 } else {
1161 err = -EMSGSIZE;
1162 goto error;
1163 }
1164
1165 if (skb->ip_summed == CHECKSUM_NONE) {
1166 unsigned int csum;
1167 csum = csum_page(page, offset, len);
1168 skb->csum = csum_block_add(skb->csum, csum, skb->len);
1169 }
1170
1171 skb->len += len;
1172 skb->data_len += len;
1173 offset += len;
1174 size -= len;
1175 }
1176 return 0;
1177
1178 error:
1179 inet->cork.length -= size;
1180 IP_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
1181 return err;
1182 }
1183
1184 /*
1185 * Combined all pending IP fragments on the socket as one IP datagram
1186 * and push them out.
1187 */
1188 int ip_push_pending_frames(struct sock *sk)
1189 {
1190 struct sk_buff *skb, *tmp_skb;
1191 struct sk_buff **tail_skb;
1192 struct inet_sock *inet = inet_sk(sk);
1193 struct ip_options *opt = NULL;
1194 struct rtable *rt = inet->cork.rt;
1195 struct iphdr *iph;
1196 __be16 df = 0;
1197 __u8 ttl;
1198 int err = 0;
1199
1200 if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL)
1201 goto out;
1202 tail_skb = &(skb_shinfo(skb)->frag_list);
1203
1204 /* move skb->data to ip header from ext header */
1205 if (skb->data < skb->nh.raw)
1206 __skb_pull(skb, skb->nh.raw - skb->data);
1207 while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) {
1208 __skb_pull(tmp_skb, skb->h.raw - skb->nh.raw);
1209 *tail_skb = tmp_skb;
1210 tail_skb = &(tmp_skb->next);
1211 skb->len += tmp_skb->len;
1212 skb->data_len += tmp_skb->len;
1213 skb->truesize += tmp_skb->truesize;
1214 __sock_put(tmp_skb->sk);
1215 tmp_skb->destructor = NULL;
1216 tmp_skb->sk = NULL;
1217 }
1218
1219 /* Unless user demanded real pmtu discovery (IP_PMTUDISC_DO), we allow
1220 * to fragment the frame generated here. No matter, what transforms
1221 * how transforms change size of the packet, it will come out.
1222 */
1223 if (inet->pmtudisc != IP_PMTUDISC_DO)
1224 skb->local_df = 1;
1225
1226 /* DF bit is set when we want to see DF on outgoing frames.
1227 * If local_df is set too, we still allow to fragment this frame
1228 * locally. */
1229 if (inet->pmtudisc == IP_PMTUDISC_DO ||
1230 (skb->len <= dst_mtu(&rt->u.dst) &&
1231 ip_dont_fragment(sk, &rt->u.dst)))
1232 df = htons(IP_DF);
1233
1234 if (inet->cork.flags & IPCORK_OPT)
1235 opt = inet->cork.opt;
1236
1237 if (rt->rt_type == RTN_MULTICAST)
1238 ttl = inet->mc_ttl;
1239 else
1240 ttl = ip_select_ttl(inet, &rt->u.dst);
1241
1242 iph = (struct iphdr *)skb->data;
1243 iph->version = 4;
1244 iph->ihl = 5;
1245 if (opt) {
1246 iph->ihl += opt->optlen>>2;
1247 ip_options_build(skb, opt, inet->cork.addr, rt, 0);
1248 }
1249 iph->tos = inet->tos;
1250 iph->tot_len = htons(skb->len);
1251 iph->frag_off = df;
1252 if (!df) {
1253 __ip_select_ident(iph, &rt->u.dst, 0);
1254 } else {
1255 iph->id = htons(inet->id++);
1256 }
1257 iph->ttl = ttl;
1258 iph->protocol = sk->sk_protocol;
1259 iph->saddr = rt->rt_src;
1260 iph->daddr = rt->rt_dst;
1261 ip_send_check(iph);
1262
1263 skb->priority = sk->sk_priority;
1264 skb->dst = dst_clone(&rt->u.dst);
1265
1266 /* Netfilter gets whole the not fragmented skb. */
1267 err = NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, skb, NULL,
1268 skb->dst->dev, dst_output);
1269 if (err) {
1270 if (err > 0)
1271 err = inet->recverr ? net_xmit_errno(err) : 0;
1272 if (err)
1273 goto error;
1274 }
1275
1276 out:
1277 inet->cork.flags &= ~IPCORK_OPT;
1278 kfree(inet->cork.opt);
1279 inet->cork.opt = NULL;
1280 if (inet->cork.rt) {
1281 ip_rt_put(inet->cork.rt);
1282 inet->cork.rt = NULL;
1283 }
1284 return err;
1285
1286 error:
1287 IP_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
1288 goto out;
1289 }
1290
1291 /*
1292 * Throw away all pending data on the socket.
1293 */
1294 void ip_flush_pending_frames(struct sock *sk)
1295 {
1296 struct inet_sock *inet = inet_sk(sk);
1297 struct sk_buff *skb;
1298
1299 while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL)
1300 kfree_skb(skb);
1301
1302 inet->cork.flags &= ~IPCORK_OPT;
1303 kfree(inet->cork.opt);
1304 inet->cork.opt = NULL;
1305 if (inet->cork.rt) {
1306 ip_rt_put(inet->cork.rt);
1307 inet->cork.rt = NULL;
1308 }
1309 }
1310
1311
1312 /*
1313 * Fetch data from kernel space and fill in checksum if needed.
1314 */
1315 static int ip_reply_glue_bits(void *dptr, char *to, int offset,
1316 int len, int odd, struct sk_buff *skb)
1317 {
1318 unsigned int csum;
1319
1320 csum = csum_partial_copy_nocheck(dptr+offset, to, len, 0);
1321 skb->csum = csum_block_add(skb->csum, csum, odd);
1322 return 0;
1323 }
1324
1325 /*
1326 * Generic function to send a packet as reply to another packet.
1327 * Used to send TCP resets so far. ICMP should use this function too.
1328 *
1329 * Should run single threaded per socket because it uses the sock
1330 * structure to pass arguments.
1331 *
1332 * LATER: switch from ip_build_xmit to ip_append_*
1333 */
1334 void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *arg,
1335 unsigned int len)
1336 {
1337 struct inet_sock *inet = inet_sk(sk);
1338 struct {
1339 struct ip_options opt;
1340 char data[40];
1341 } replyopts;
1342 struct ipcm_cookie ipc;
1343 u32 daddr;
1344 struct rtable *rt = (struct rtable*)skb->dst;
1345
1346 if (ip_options_echo(&replyopts.opt, skb))
1347 return;
1348
1349 daddr = ipc.addr = rt->rt_src;
1350 ipc.opt = NULL;
1351
1352 if (replyopts.opt.optlen) {
1353 ipc.opt = &replyopts.opt;
1354
1355 if (ipc.opt->srr)
1356 daddr = replyopts.opt.faddr;
1357 }
1358
1359 {
1360 struct flowi fl = { .nl_u = { .ip4_u =
1361 { .daddr = daddr,
1362 .saddr = rt->rt_spec_dst,
1363 .tos = RT_TOS(skb->nh.iph->tos) } },
1364 /* Not quite clean, but right. */
1365 .uli_u = { .ports =
1366 { .sport = skb->h.th->dest,
1367 .dport = skb->h.th->source } },
1368 .proto = sk->sk_protocol };
1369 if (ip_route_output_key(&rt, &fl))
1370 return;
1371 }
1372
1373 /* And let IP do all the hard work.
1374
1375 This chunk is not reenterable, hence spinlock.
1376 Note that it uses the fact, that this function is called
1377 with locally disabled BH and that sk cannot be already spinlocked.
1378 */
1379 bh_lock_sock(sk);
1380 inet->tos = skb->nh.iph->tos;
1381 sk->sk_priority = skb->priority;
1382 sk->sk_protocol = skb->nh.iph->protocol;
1383 ip_append_data(sk, ip_reply_glue_bits, arg->iov->iov_base, len, 0,
1384 &ipc, rt, MSG_DONTWAIT);
1385 if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) {
1386 if (arg->csumoffset >= 0)
1387 *((u16 *)skb->h.raw + arg->csumoffset) = csum_fold(csum_add(skb->csum, arg->csum));
1388 skb->ip_summed = CHECKSUM_NONE;
1389 ip_push_pending_frames(sk);
1390 }
1391
1392 bh_unlock_sock(sk);
1393
1394 ip_rt_put(rt);
1395 }
1396
1397 void __init ip_init(void)
1398 {
1399 ip_rt_init();
1400 inet_initpeers();
1401
1402 #if defined(CONFIG_IP_MULTICAST) && defined(CONFIG_PROC_FS)
1403 igmp_mc_proc_init();
1404 #endif
1405 }
1406
1407 EXPORT_SYMBOL(ip_generic_getfrag);
1408 EXPORT_SYMBOL(ip_queue_xmit);
1409 EXPORT_SYMBOL(ip_send_check);
linux v2.6.22.y-op