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[IPV4]: Fix SNMPv2 "ipFragFails" counter error
[linux-2.6/linux-loongson.git] / net / ipv4 / ip_output.c
bloba2ede167e045b32340e3a1346b8ccde641cb6b68
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
57 #include <linux/socket.h>
58 #include <linux/sockios.h>
59 #include <linux/in.h>
60 #include <linux/inet.h>
61 #include <linux/netdevice.h>
62 #include <linux/etherdevice.h>
63 #include <linux/proc_fs.h>
64 #include <linux/stat.h>
65 #include <linux/init.h>
66
67 #include <net/snmp.h>
68 #include <net/ip.h>
69 #include <net/protocol.h>
70 #include <net/route.h>
71 #include <net/xfrm.h>
72 #include <linux/skbuff.h>
73 #include <net/sock.h>
74 #include <net/arp.h>
75 #include <net/icmp.h>
76 #include <net/checksum.h>
77 #include <net/inetpeer.h>
78 #include <net/checksum.h>
79 #include <linux/igmp.h>
80 #include <linux/netfilter_ipv4.h>
81 #include <linux/netfilter_bridge.h>
82 #include <linux/mroute.h>
83 #include <linux/netlink.h>
84 #include <linux/tcp.h>
85
86 int sysctl_ip_default_ttl = IPDEFTTL;
87
88 /* Generate a checksum for an outgoing IP datagram. */
89 __inline__ void ip_send_check(struct iphdr *iph)
90 {
91 iph->check = 0;
92 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
93 }
94
95 /* dev_loopback_xmit for use with netfilter. */
96 static int ip_dev_loopback_xmit(struct sk_buff *newskb)
97 {
98 newskb->mac.raw = newskb->data;
99 __skb_pull(newskb, newskb->nh.raw - newskb->data);
100 newskb->pkt_type = PACKET_LOOPBACK;
101 newskb->ip_summed = CHECKSUM_UNNECESSARY;
102 BUG_TRAP(newskb->dst);
103 netif_rx(newskb);
104 return 0;
105 }
106
107 static inline int ip_select_ttl(struct inet_sock *inet, struct dst_entry *dst)
108 {
109 int ttl = inet->uc_ttl;
110
111 if (ttl < 0)
112 ttl = dst_metric(dst, RTAX_HOPLIMIT);
113 return ttl;
114 }
115
116 /*
117 * Add an ip header to a skbuff and send it out.
118 *
119 */
120 int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk,
121 u32 saddr, u32 daddr, struct ip_options *opt)
122 {
123 struct inet_sock *inet = inet_sk(sk);
124 struct rtable *rt = (struct rtable *)skb->dst;
125 struct iphdr *iph;
126
127 /* Build the IP header. */
128 if (opt)
129 iph=(struct iphdr *)skb_push(skb,sizeof(struct iphdr) + opt->optlen);
130 else
131 iph=(struct iphdr *)skb_push(skb,sizeof(struct iphdr));
132
133 iph->version = 4;
134 iph->ihl = 5;
135 iph->tos = inet->tos;
136 if (ip_dont_fragment(sk, &rt->u.dst))
137 iph->frag_off = htons(IP_DF);
138 else
139 iph->frag_off = 0;
140 iph->ttl = ip_select_ttl(inet, &rt->u.dst);
141 iph->daddr = rt->rt_dst;
142 iph->saddr = rt->rt_src;
143 iph->protocol = sk->sk_protocol;
144 iph->tot_len = htons(skb->len);
145 ip_select_ident(iph, &rt->u.dst, sk);
146 skb->nh.iph = iph;
147
148 if (opt && opt->optlen) {
149 iph->ihl += opt->optlen>>2;
150 ip_options_build(skb, opt, daddr, rt, 0);
151 }
152 ip_send_check(iph);
153
154 skb->priority = sk->sk_priority;
155
156 /* Send it out. */
157 return NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, skb, NULL, rt->u.dst.dev,
158 dst_output);
159 }
160
161 EXPORT_SYMBOL_GPL(ip_build_and_send_pkt);
162
163 static inline int ip_finish_output2(struct sk_buff *skb)
164 {
165 struct dst_entry *dst = skb->dst;
166 struct hh_cache *hh = dst->hh;
167 struct net_device *dev = dst->dev;
168 int hh_len = LL_RESERVED_SPACE(dev);
169
170 /* Be paranoid, rather than too clever. */
171 if (unlikely(skb_headroom(skb) < hh_len && dev->hard_header)) {
172 struct sk_buff *skb2;
173
174 skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev));
175 if (skb2 == NULL) {
176 kfree_skb(skb);
177 return -ENOMEM;
178 }
179 if (skb->sk)
180 skb_set_owner_w(skb2, skb->sk);
181 kfree_skb(skb);
182 skb = skb2;
183 }
184
185 if (hh) {
186 int hh_alen;
187
188 read_lock_bh(&hh->hh_lock);
189 hh_alen = HH_DATA_ALIGN(hh->hh_len);
190 memcpy(skb->data - hh_alen, hh->hh_data, hh_alen);
191 read_unlock_bh(&hh->hh_lock);
192 skb_push(skb, hh->hh_len);
193 return hh->hh_output(skb);
194 } else if (dst->neighbour)
195 return dst->neighbour->output(skb);
196
197 if (net_ratelimit())
198 printk(KERN_DEBUG "ip_finish_output2: No header cache and no neighbour!\n");
199 kfree_skb(skb);
200 return -EINVAL;
201 }
202
203 static inline int ip_finish_output(struct sk_buff *skb)
204 {
205 #if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM)
206 /* Policy lookup after SNAT yielded a new policy */
207 if (skb->dst->xfrm != NULL) {
208 IPCB(skb)->flags |= IPSKB_REROUTED;
209 return dst_output(skb);
210 }
211 #endif
212 if (skb->len > dst_mtu(skb->dst) && !skb_is_gso(skb))
213 return ip_fragment(skb, ip_finish_output2);
214 else
215 return ip_finish_output2(skb);
216 }
217
218 int ip_mc_output(struct sk_buff *skb)
219 {
220 struct sock *sk = skb->sk;
221 struct rtable *rt = (struct rtable*)skb->dst;
222 struct net_device *dev = rt->u.dst.dev;
223
224 /*
225 * If the indicated interface is up and running, send the packet.
226 */
227 IP_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
228
229 skb->dev = dev;
230 skb->protocol = htons(ETH_P_IP);
231
232 /*
233 * Multicasts are looped back for other local users
234 */
235
236 if (rt->rt_flags&RTCF_MULTICAST) {
237 if ((!sk || inet_sk(sk)->mc_loop)
238 #ifdef CONFIG_IP_MROUTE
239 /* Small optimization: do not loopback not local frames,
240 which returned after forwarding; they will be dropped
241 by ip_mr_input in any case.
242 Note, that local frames are looped back to be delivered
243 to local recipients.
244
245 This check is duplicated in ip_mr_input at the moment.
246 */
247 && ((rt->rt_flags&RTCF_LOCAL) || !(IPCB(skb)->flags&IPSKB_FORWARDED))
248 #endif
249 ) {
250 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
251 if (newskb)
252 NF_HOOK(PF_INET, NF_IP_POST_ROUTING, newskb, NULL,
253 newskb->dev,
254 ip_dev_loopback_xmit);
255 }
256
257 /* Multicasts with ttl 0 must not go beyond the host */
258
259 if (skb->nh.iph->ttl == 0) {
260 kfree_skb(skb);
261 return 0;
262 }
263 }
264
265 if (rt->rt_flags&RTCF_BROADCAST) {
266 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
267 if (newskb)
268 NF_HOOK(PF_INET, NF_IP_POST_ROUTING, newskb, NULL,
269 newskb->dev, ip_dev_loopback_xmit);
270 }
271
272 return NF_HOOK_COND(PF_INET, NF_IP_POST_ROUTING, skb, NULL, skb->dev,
273 ip_finish_output,
274 !(IPCB(skb)->flags & IPSKB_REROUTED));
275 }
276
277 int ip_output(struct sk_buff *skb)
278 {
279 struct net_device *dev = skb->dst->dev;
280
281 IP_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
282
283 skb->dev = dev;
284 skb->protocol = htons(ETH_P_IP);
285
286 return NF_HOOK_COND(PF_INET, NF_IP_POST_ROUTING, skb, NULL, dev,
287 ip_finish_output,
288 !(IPCB(skb)->flags & IPSKB_REROUTED));
289 }
290
291 int ip_queue_xmit(struct sk_buff *skb, int ipfragok)
292 {
293 struct sock *sk = skb->sk;
294 struct inet_sock *inet = inet_sk(sk);
295 struct ip_options *opt = inet->opt;
296 struct rtable *rt;
297 struct iphdr *iph;
298
299 /* Skip all of this if the packet is already routed,
300 * f.e. by something like SCTP.
301 */
302 rt = (struct rtable *) skb->dst;
303 if (rt != NULL)
304 goto packet_routed;
305
306 /* Make sure we can route this packet. */
307 rt = (struct rtable *)__sk_dst_check(sk, 0);
308 if (rt == NULL) {
309 u32 daddr;
310
311 /* Use correct destination address if we have options. */
312 daddr = inet->daddr;
313 if(opt && opt->srr)
314 daddr = opt->faddr;
315
316 {
317 struct flowi fl = { .oif = sk->sk_bound_dev_if,
318 .nl_u = { .ip4_u =
319 { .daddr = daddr,
320 .saddr = inet->saddr,
321 .tos = RT_CONN_FLAGS(sk) } },
322 .proto = sk->sk_protocol,
323 .uli_u = { .ports =
324 { .sport = inet->sport,
325 .dport = inet->dport } } };
326
327 /* If this fails, retransmit mechanism of transport layer will
328 * keep trying until route appears or the connection times
329 * itself out.
330 */
331 if (ip_route_output_flow(&rt, &fl, sk, 0))
332 goto no_route;
333 }
334 sk_setup_caps(sk, &rt->u.dst);
335 }
336 skb->dst = dst_clone(&rt->u.dst);
337
338 packet_routed:
339 if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway)
340 goto no_route;
341
342 /* OK, we know where to send it, allocate and build IP header. */
343 iph = (struct iphdr *) skb_push(skb, sizeof(struct iphdr) + (opt ? opt->optlen : 0));
344 *((__u16 *)iph) = htons((4 << 12) | (5 << 8) | (inet->tos & 0xff));
345 iph->tot_len = htons(skb->len);
346 if (ip_dont_fragment(sk, &rt->u.dst) && !ipfragok)
347 iph->frag_off = htons(IP_DF);
348 else
349 iph->frag_off = 0;
350 iph->ttl = ip_select_ttl(inet, &rt->u.dst);
351 iph->protocol = sk->sk_protocol;
352 iph->saddr = rt->rt_src;
353 iph->daddr = rt->rt_dst;
354 skb->nh.iph = iph;
355 /* Transport layer set skb->h.foo itself. */
356
357 if (opt && opt->optlen) {
358 iph->ihl += opt->optlen >> 2;
359 ip_options_build(skb, opt, inet->daddr, rt, 0);
360 }
361
362 ip_select_ident_more(iph, &rt->u.dst, sk,
363 (skb_shinfo(skb)->gso_segs ?: 1) - 1);
364
365 /* Add an IP checksum. */
366 ip_send_check(iph);
367
368 skb->priority = sk->sk_priority;
369
370 return NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, skb, NULL, rt->u.dst.dev,
371 dst_output);
372
373 no_route:
374 IP_INC_STATS(IPSTATS_MIB_OUTNOROUTES);
375 kfree_skb(skb);
376 return -EHOSTUNREACH;
377 }
378
379
380 static void ip_copy_metadata(struct sk_buff *to, struct sk_buff *from)
381 {
382 to->pkt_type = from->pkt_type;
383 to->priority = from->priority;
384 to->protocol = from->protocol;
385 dst_release(to->dst);
386 to->dst = dst_clone(from->dst);
387 to->dev = from->dev;
388
389 /* Copy the flags to each fragment. */
390 IPCB(to)->flags = IPCB(from)->flags;
391
392 #ifdef CONFIG_NET_SCHED
393 to->tc_index = from->tc_index;
394 #endif
395 #ifdef CONFIG_NETFILTER
396 to->nfmark = from->nfmark;
397 /* Connection association is same as pre-frag packet */
398 nf_conntrack_put(to->nfct);
399 to->nfct = from->nfct;
400 nf_conntrack_get(to->nfct);
401 to->nfctinfo = from->nfctinfo;
402 #if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE)
403 to->ipvs_property = from->ipvs_property;
404 #endif
405 #ifdef CONFIG_BRIDGE_NETFILTER
406 nf_bridge_put(to->nf_bridge);
407 to->nf_bridge = from->nf_bridge;
408 nf_bridge_get(to->nf_bridge);
409 #endif
410 #endif
411 skb_copy_secmark(to, from);
412 }
413
414 /*
415 * This IP datagram is too large to be sent in one piece. Break it up into
416 * smaller pieces (each of size equal to IP header plus
417 * a block of the data of the original IP data part) that will yet fit in a
418 * single device frame, and queue such a frame for sending.
419 */
420
421 int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff*))
422 {
423 struct iphdr *iph;
424 int raw = 0;
425 int ptr;
426 struct net_device *dev;
427 struct sk_buff *skb2;
428 unsigned int mtu, hlen, left, len, ll_rs;
429 int offset;
430 __be16 not_last_frag;
431 struct rtable *rt = (struct rtable*)skb->dst;
432 int err = 0;
433
434 dev = rt->u.dst.dev;
435
436 /*
437 * Point into the IP datagram header.
438 */
439
440 iph = skb->nh.iph;
441
442 if (unlikely((iph->frag_off & htons(IP_DF)) && !skb->local_df)) {
443 IP_INC_STATS(IPSTATS_MIB_FRAGFAILS);
444 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
445 htonl(dst_mtu(&rt->u.dst)));
446 kfree_skb(skb);
447 return -EMSGSIZE;
448 }
449
450 /*
451 * Setup starting values.
452 */
453
454 hlen = iph->ihl * 4;
455 mtu = dst_mtu(&rt->u.dst) - hlen; /* Size of data space */
456 IPCB(skb)->flags |= IPSKB_FRAG_COMPLETE;
457
458 /* When frag_list is given, use it. First, check its validity:
459 * some transformers could create wrong frag_list or break existing
460 * one, it is not prohibited. In this case fall back to copying.
461 *
462 * LATER: this step can be merged to real generation of fragments,
463 * we can switch to copy when see the first bad fragment.
464 */
465 if (skb_shinfo(skb)->frag_list) {
466 struct sk_buff *frag;
467 int first_len = skb_pagelen(skb);
468
469 if (first_len - hlen > mtu ||
470 ((first_len - hlen) & 7) ||
471 (iph->frag_off & htons(IP_MF|IP_OFFSET)) ||
472 skb_cloned(skb))
473 goto slow_path;
474
475 for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) {
476 /* Correct geometry. */
477 if (frag->len > mtu ||
478 ((frag->len & 7) && frag->next) ||
479 skb_headroom(frag) < hlen)
480 goto slow_path;
481
482 /* Partially cloned skb? */
483 if (skb_shared(frag))
484 goto slow_path;
485
486 BUG_ON(frag->sk);
487 if (skb->sk) {
488 sock_hold(skb->sk);
489 frag->sk = skb->sk;
490 frag->destructor = sock_wfree;
491 skb->truesize -= frag->truesize;
492 }
493 }
494
495 /* Everything is OK. Generate! */
496
497 err = 0;
498 offset = 0;
499 frag = skb_shinfo(skb)->frag_list;
500 skb_shinfo(skb)->frag_list = NULL;
501 skb->data_len = first_len - skb_headlen(skb);
502 skb->len = first_len;
503 iph->tot_len = htons(first_len);
504 iph->frag_off = htons(IP_MF);
505 ip_send_check(iph);
506
507 for (;;) {
508 /* Prepare header of the next frame,
509 * before previous one went down. */
510 if (frag) {
511 frag->ip_summed = CHECKSUM_NONE;
512 frag->h.raw = frag->data;
513 frag->nh.raw = __skb_push(frag, hlen);
514 memcpy(frag->nh.raw, iph, hlen);
515 iph = frag->nh.iph;
516 iph->tot_len = htons(frag->len);
517 ip_copy_metadata(frag, skb);
518 if (offset == 0)
519 ip_options_fragment(frag);
520 offset += skb->len - hlen;
521 iph->frag_off = htons(offset>>3);
522 if (frag->next != NULL)
523 iph->frag_off |= htons(IP_MF);
524 /* Ready, complete checksum */
525 ip_send_check(iph);
526 }
527
528 err = output(skb);
529
530 if (!err)
531 IP_INC_STATS(IPSTATS_MIB_FRAGCREATES);
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 iph->tot_len = htons(len + hlen);
656
657 ip_send_check(iph);
658
659 err = output(skb2);
660 if (err)
661 goto fail;
662
663 IP_INC_STATS(IPSTATS_MIB_FRAGCREATES);
664 }
665 kfree_skb(skb);
666 IP_INC_STATS(IPSTATS_MIB_FRAGOKS);
667 return err;
668
669 fail:
670 kfree_skb(skb);
671 IP_INC_STATS(IPSTATS_MIB_FRAGFAILS);
672 return err;
673 }
674
675 EXPORT_SYMBOL(ip_fragment);
676
677 int
678 ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb)
679 {
680 struct iovec *iov = from;
681
682 if (skb->ip_summed == CHECKSUM_HW) {
683 if (memcpy_fromiovecend(to, iov, offset, len) < 0)
684 return -EFAULT;
685 } else {
686 unsigned int csum = 0;
687 if (csum_partial_copy_fromiovecend(to, iov, offset, len, &csum) < 0)
688 return -EFAULT;
689 skb->csum = csum_block_add(skb->csum, csum, odd);
690 }
691 return 0;
692 }
693
694 static inline unsigned int
695 csum_page(struct page *page, int offset, int copy)
696 {
697 char *kaddr;
698 unsigned int csum;
699 kaddr = kmap(page);
700 csum = csum_partial(kaddr + offset, copy, 0);
701 kunmap(page);
702 return csum;
703 }
704
705 static inline int ip_ufo_append_data(struct sock *sk,
706 int getfrag(void *from, char *to, int offset, int len,
707 int odd, struct sk_buff *skb),
708 void *from, int length, int hh_len, int fragheaderlen,
709 int transhdrlen, int mtu,unsigned int flags)
710 {
711 struct sk_buff *skb;
712 int err;
713
714 /* There is support for UDP fragmentation offload by network
715 * device, so create one single skb packet containing complete
716 * udp datagram
717 */
718 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) {
719 skb = sock_alloc_send_skb(sk,
720 hh_len + fragheaderlen + transhdrlen + 20,
721 (flags & MSG_DONTWAIT), &err);
722
723 if (skb == NULL)
724 return err;
725
726 /* reserve space for Hardware header */
727 skb_reserve(skb, hh_len);
728
729 /* create space for UDP/IP header */
730 skb_put(skb,fragheaderlen + transhdrlen);
731
732 /* initialize network header pointer */
733 skb->nh.raw = skb->data;
734
735 /* initialize protocol header pointer */
736 skb->h.raw = skb->data + fragheaderlen;
737
738 skb->ip_summed = CHECKSUM_HW;
739 skb->csum = 0;
740 sk->sk_sndmsg_off = 0;
741 }
742
743 err = skb_append_datato_frags(sk,skb, getfrag, from,
744 (length - transhdrlen));
745 if (!err) {
746 /* specify the length of each IP datagram fragment*/
747 skb_shinfo(skb)->gso_size = mtu - fragheaderlen;
748 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
749 __skb_queue_tail(&sk->sk_write_queue, skb);
750
751 return 0;
752 }
753 /* There is not enough support do UFO ,
754 * so follow normal path
755 */
756 kfree_skb(skb);
757 return err;
758 }
759
760 /*
761 * ip_append_data() and ip_append_page() can make one large IP datagram
762 * from many pieces of data. Each pieces will be holded on the socket
763 * until ip_push_pending_frames() is called. Each piece can be a page
764 * or non-page data.
765 *
766 * Not only UDP, other transport protocols - e.g. raw sockets - can use
767 * this interface potentially.
768 *
769 * LATER: length must be adjusted by pad at tail, when it is required.
770 */
771 int ip_append_data(struct sock *sk,
772 int getfrag(void *from, char *to, int offset, int len,
773 int odd, struct sk_buff *skb),
774 void *from, int length, int transhdrlen,
775 struct ipcm_cookie *ipc, struct rtable *rt,
776 unsigned int flags)
777 {
778 struct inet_sock *inet = inet_sk(sk);
779 struct sk_buff *skb;
780
781 struct ip_options *opt = NULL;
782 int hh_len;
783 int exthdrlen;
784 int mtu;
785 int copy;
786 int err;
787 int offset = 0;
788 unsigned int maxfraglen, fragheaderlen;
789 int csummode = CHECKSUM_NONE;
790
791 if (flags&MSG_PROBE)
792 return 0;
793
794 if (skb_queue_empty(&sk->sk_write_queue)) {
795 /*
796 * setup for corking.
797 */
798 opt = ipc->opt;
799 if (opt) {
800 if (inet->cork.opt == NULL) {
801 inet->cork.opt = kmalloc(sizeof(struct ip_options) + 40, sk->sk_allocation);
802 if (unlikely(inet->cork.opt == NULL))
803 return -ENOBUFS;
804 }
805 memcpy(inet->cork.opt, opt, sizeof(struct ip_options)+opt->optlen);
806 inet->cork.flags |= IPCORK_OPT;
807 inet->cork.addr = ipc->addr;
808 }
809 dst_hold(&rt->u.dst);
810 inet->cork.fragsize = mtu = dst_mtu(rt->u.dst.path);
811 inet->cork.rt = rt;
812 inet->cork.length = 0;
813 sk->sk_sndmsg_page = NULL;
814 sk->sk_sndmsg_off = 0;
815 if ((exthdrlen = rt->u.dst.header_len) != 0) {
816 length += exthdrlen;
817 transhdrlen += exthdrlen;
818 }
819 } else {
820 rt = inet->cork.rt;
821 if (inet->cork.flags & IPCORK_OPT)
822 opt = inet->cork.opt;
823
824 transhdrlen = 0;
825 exthdrlen = 0;
826 mtu = inet->cork.fragsize;
827 }
828 hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);
829
830 fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0);
831 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen;
832
833 if (inet->cork.length + length > 0xFFFF - fragheaderlen) {
834 ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->dport, mtu-exthdrlen);
835 return -EMSGSIZE;
836 }
837
838 /*
839 * transhdrlen > 0 means that this is the first fragment and we wish
840 * it won't be fragmented in the future.
841 */
842 if (transhdrlen &&
843 length + fragheaderlen <= mtu &&
844 rt->u.dst.dev->features & NETIF_F_ALL_CSUM &&
845 !exthdrlen)
846 csummode = CHECKSUM_HW;
847
848 inet->cork.length += length;
849 if (((length > mtu) && (sk->sk_protocol == IPPROTO_UDP)) &&
850 (rt->u.dst.dev->features & NETIF_F_UFO)) {
851
852 err = ip_ufo_append_data(sk, getfrag, from, length, hh_len,
853 fragheaderlen, transhdrlen, mtu,
854 flags);
855 if (err)
856 goto error;
857 return 0;
858 }
859
860 /* So, what's going on in the loop below?
861 *
862 * We use calculated fragment length to generate chained skb,
863 * each of segments is IP fragment ready for sending to network after
864 * adding appropriate IP header.
865 */
866
867 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL)
868 goto alloc_new_skb;
869
870 while (length > 0) {
871 /* Check if the remaining data fits into current packet. */
872 copy = mtu - skb->len;
873 if (copy < length)
874 copy = maxfraglen - skb->len;
875 if (copy <= 0) {
876 char *data;
877 unsigned int datalen;
878 unsigned int fraglen;
879 unsigned int fraggap;
880 unsigned int alloclen;
881 struct sk_buff *skb_prev;
882 alloc_new_skb:
883 skb_prev = skb;
884 if (skb_prev)
885 fraggap = skb_prev->len - maxfraglen;
886 else
887 fraggap = 0;
888
889 /*
890 * If remaining data exceeds the mtu,
891 * we know we need more fragment(s).
892 */
893 datalen = length + fraggap;
894 if (datalen > mtu - fragheaderlen)
895 datalen = maxfraglen - fragheaderlen;
896 fraglen = datalen + fragheaderlen;
897
898 if ((flags & MSG_MORE) &&
899 !(rt->u.dst.dev->features&NETIF_F_SG))
900 alloclen = mtu;
901 else
902 alloclen = datalen + fragheaderlen;
903
904 /* The last fragment gets additional space at tail.
905 * Note, with MSG_MORE we overallocate on fragments,
906 * because we have no idea what fragment will be
907 * the last.
908 */
909 if (datalen == length + fraggap)
910 alloclen += rt->u.dst.trailer_len;
911
912 if (transhdrlen) {
913 skb = sock_alloc_send_skb(sk,
914 alloclen + hh_len + 15,
915 (flags & MSG_DONTWAIT), &err);
916 } else {
917 skb = NULL;
918 if (atomic_read(&sk->sk_wmem_alloc) <=
919 2 * sk->sk_sndbuf)
920 skb = sock_wmalloc(sk,
921 alloclen + hh_len + 15, 1,
922 sk->sk_allocation);
923 if (unlikely(skb == NULL))
924 err = -ENOBUFS;
925 }
926 if (skb == NULL)
927 goto error;
928
929 /*
930 * Fill in the control structures
931 */
932 skb->ip_summed = csummode;
933 skb->csum = 0;
934 skb_reserve(skb, hh_len);
935
936 /*
937 * Find where to start putting bytes.
938 */
939 data = skb_put(skb, fraglen);
940 skb->nh.raw = data + exthdrlen;
941 data += fragheaderlen;
942 skb->h.raw = data + exthdrlen;
943
944 if (fraggap) {
945 skb->csum = skb_copy_and_csum_bits(
946 skb_prev, maxfraglen,
947 data + transhdrlen, fraggap, 0);
948 skb_prev->csum = csum_sub(skb_prev->csum,
949 skb->csum);
950 data += fraggap;
951 pskb_trim_unique(skb_prev, maxfraglen);
952 }
953
954 copy = datalen - transhdrlen - fraggap;
955 if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) {
956 err = -EFAULT;
957 kfree_skb(skb);
958 goto error;
959 }
960
961 offset += copy;
962 length -= datalen - fraggap;
963 transhdrlen = 0;
964 exthdrlen = 0;
965 csummode = CHECKSUM_NONE;
966
967 /*
968 * Put the packet on the pending queue.
969 */
970 __skb_queue_tail(&sk->sk_write_queue, skb);
971 continue;
972 }
973
974 if (copy > length)
975 copy = length;
976
977 if (!(rt->u.dst.dev->features&NETIF_F_SG)) {
978 unsigned int off;
979
980 off = skb->len;
981 if (getfrag(from, skb_put(skb, copy),
982 offset, copy, off, skb) < 0) {
983 __skb_trim(skb, off);
984 err = -EFAULT;
985 goto error;
986 }
987 } else {
988 int i = skb_shinfo(skb)->nr_frags;
989 skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1];
990 struct page *page = sk->sk_sndmsg_page;
991 int off = sk->sk_sndmsg_off;
992 unsigned int left;
993
994 if (page && (left = PAGE_SIZE - off) > 0) {
995 if (copy >= left)
996 copy = left;
997 if (page != frag->page) {
998 if (i == MAX_SKB_FRAGS) {
999 err = -EMSGSIZE;
1000 goto error;
1001 }
1002 get_page(page);
1003 skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0);
1004 frag = &skb_shinfo(skb)->frags[i];
1005 }
1006 } else if (i < MAX_SKB_FRAGS) {
1007 if (copy > PAGE_SIZE)
1008 copy = PAGE_SIZE;
1009 page = alloc_pages(sk->sk_allocation, 0);
1010 if (page == NULL) {
1011 err = -ENOMEM;
1012 goto error;
1013 }
1014 sk->sk_sndmsg_page = page;
1015 sk->sk_sndmsg_off = 0;
1016
1017 skb_fill_page_desc(skb, i, page, 0, 0);
1018 frag = &skb_shinfo(skb)->frags[i];
1019 skb->truesize += PAGE_SIZE;
1020 atomic_add(PAGE_SIZE, &sk->sk_wmem_alloc);
1021 } else {
1022 err = -EMSGSIZE;
1023 goto error;
1024 }
1025 if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) {
1026 err = -EFAULT;
1027 goto error;
1028 }
1029 sk->sk_sndmsg_off += copy;
1030 frag->size += copy;
1031 skb->len += copy;
1032 skb->data_len += copy;
1033 }
1034 offset += copy;
1035 length -= copy;
1036 }
1037
1038 return 0;
1039
1040 error:
1041 inet->cork.length -= length;
1042 IP_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
1043 return err;
1044 }
1045
1046 ssize_t ip_append_page(struct sock *sk, struct page *page,
1047 int offset, size_t size, int flags)
1048 {
1049 struct inet_sock *inet = inet_sk(sk);
1050 struct sk_buff *skb;
1051 struct rtable *rt;
1052 struct ip_options *opt = NULL;
1053 int hh_len;
1054 int mtu;
1055 int len;
1056 int err;
1057 unsigned int maxfraglen, fragheaderlen, fraggap;
1058
1059 if (inet->hdrincl)
1060 return -EPERM;
1061
1062 if (flags&MSG_PROBE)
1063 return 0;
1064
1065 if (skb_queue_empty(&sk->sk_write_queue))
1066 return -EINVAL;
1067
1068 rt = inet->cork.rt;
1069 if (inet->cork.flags & IPCORK_OPT)
1070 opt = inet->cork.opt;
1071
1072 if (!(rt->u.dst.dev->features&NETIF_F_SG))
1073 return -EOPNOTSUPP;
1074
1075 hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);
1076 mtu = inet->cork.fragsize;
1077
1078 fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0);
1079 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen;
1080
1081 if (inet->cork.length + size > 0xFFFF - fragheaderlen) {
1082 ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->dport, mtu);
1083 return -EMSGSIZE;
1084 }
1085
1086 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL)
1087 return -EINVAL;
1088
1089 inet->cork.length += size;
1090 if ((sk->sk_protocol == IPPROTO_UDP) &&
1091 (rt->u.dst.dev->features & NETIF_F_UFO)) {
1092 skb_shinfo(skb)->gso_size = mtu - fragheaderlen;
1093 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
1094 }
1095
1096
1097 while (size > 0) {
1098 int i;
1099
1100 if (skb_is_gso(skb))
1101 len = size;
1102 else {
1103
1104 /* Check if the remaining data fits into current packet. */
1105 len = mtu - skb->len;
1106 if (len < size)
1107 len = maxfraglen - skb->len;
1108 }
1109 if (len <= 0) {
1110 struct sk_buff *skb_prev;
1111 char *data;
1112 struct iphdr *iph;
1113 int alloclen;
1114
1115 skb_prev = skb;
1116 fraggap = skb_prev->len - maxfraglen;
1117
1118 alloclen = fragheaderlen + hh_len + fraggap + 15;
1119 skb = sock_wmalloc(sk, alloclen, 1, sk->sk_allocation);
1120 if (unlikely(!skb)) {
1121 err = -ENOBUFS;
1122 goto error;
1123 }
1124
1125 /*
1126 * Fill in the control structures
1127 */
1128 skb->ip_summed = CHECKSUM_NONE;
1129 skb->csum = 0;
1130 skb_reserve(skb, hh_len);
1131
1132 /*
1133 * Find where to start putting bytes.
1134 */
1135 data = skb_put(skb, fragheaderlen + fraggap);
1136 skb->nh.iph = iph = (struct iphdr *)data;
1137 data += fragheaderlen;
1138 skb->h.raw = data;
1139
1140 if (fraggap) {
1141 skb->csum = skb_copy_and_csum_bits(
1142 skb_prev, maxfraglen,
1143 data, fraggap, 0);
1144 skb_prev->csum = csum_sub(skb_prev->csum,
1145 skb->csum);
1146 pskb_trim_unique(skb_prev, maxfraglen);
1147 }
1148
1149 /*
1150 * Put the packet on the pending queue.
1151 */
1152 __skb_queue_tail(&sk->sk_write_queue, skb);
1153 continue;
1154 }
1155
1156 i = skb_shinfo(skb)->nr_frags;
1157 if (len > size)
1158 len = size;
1159 if (skb_can_coalesce(skb, i, page, offset)) {
1160 skb_shinfo(skb)->frags[i-1].size += len;
1161 } else if (i < MAX_SKB_FRAGS) {
1162 get_page(page);
1163 skb_fill_page_desc(skb, i, page, offset, len);
1164 } else {
1165 err = -EMSGSIZE;
1166 goto error;
1167 }
1168
1169 if (skb->ip_summed == CHECKSUM_NONE) {
1170 unsigned int csum;
1171 csum = csum_page(page, offset, len);
1172 skb->csum = csum_block_add(skb->csum, csum, skb->len);
1173 }
1174
1175 skb->len += len;
1176 skb->data_len += len;
1177 offset += len;
1178 size -= len;
1179 }
1180 return 0;
1181
1182 error:
1183 inet->cork.length -= size;
1184 IP_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
1185 return err;
1186 }
1187
1188 /*
1189 * Combined all pending IP fragments on the socket as one IP datagram
1190 * and push them out.
1191 */
1192 int ip_push_pending_frames(struct sock *sk)
1193 {
1194 struct sk_buff *skb, *tmp_skb;
1195 struct sk_buff **tail_skb;
1196 struct inet_sock *inet = inet_sk(sk);
1197 struct ip_options *opt = NULL;
1198 struct rtable *rt = inet->cork.rt;
1199 struct iphdr *iph;
1200 __be16 df = 0;
1201 __u8 ttl;
1202 int err = 0;
1203
1204 if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL)
1205 goto out;
1206 tail_skb = &(skb_shinfo(skb)->frag_list);
1207
1208 /* move skb->data to ip header from ext header */
1209 if (skb->data < skb->nh.raw)
1210 __skb_pull(skb, skb->nh.raw - skb->data);
1211 while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) {
1212 __skb_pull(tmp_skb, skb->h.raw - skb->nh.raw);
1213 *tail_skb = tmp_skb;
1214 tail_skb = &(tmp_skb->next);
1215 skb->len += tmp_skb->len;
1216 skb->data_len += tmp_skb->len;
1217 skb->truesize += tmp_skb->truesize;
1218 __sock_put(tmp_skb->sk);
1219 tmp_skb->destructor = NULL;
1220 tmp_skb->sk = NULL;
1221 }
1222
1223 /* Unless user demanded real pmtu discovery (IP_PMTUDISC_DO), we allow
1224 * to fragment the frame generated here. No matter, what transforms
1225 * how transforms change size of the packet, it will come out.
1226 */
1227 if (inet->pmtudisc != IP_PMTUDISC_DO)
1228 skb->local_df = 1;
1229
1230 /* DF bit is set when we want to see DF on outgoing frames.
1231 * If local_df is set too, we still allow to fragment this frame
1232 * locally. */
1233 if (inet->pmtudisc == IP_PMTUDISC_DO ||
1234 (skb->len <= dst_mtu(&rt->u.dst) &&
1235 ip_dont_fragment(sk, &rt->u.dst)))
1236 df = htons(IP_DF);
1237
1238 if (inet->cork.flags & IPCORK_OPT)
1239 opt = inet->cork.opt;
1240
1241 if (rt->rt_type == RTN_MULTICAST)
1242 ttl = inet->mc_ttl;
1243 else
1244 ttl = ip_select_ttl(inet, &rt->u.dst);
1245
1246 iph = (struct iphdr *)skb->data;
1247 iph->version = 4;
1248 iph->ihl = 5;
1249 if (opt) {
1250 iph->ihl += opt->optlen>>2;
1251 ip_options_build(skb, opt, inet->cork.addr, rt, 0);
1252 }
1253 iph->tos = inet->tos;
1254 iph->tot_len = htons(skb->len);
1255 iph->frag_off = df;
1256 ip_select_ident(iph, &rt->u.dst, sk);
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 kernel for loongson