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[XFRM]: Fix protocol field value for outgoing IPv6 GSO packets
[linux-2.6-block.git] / net / ipv6 / ip6_output.c
CommitLineData
1da177e4
LT		 1/*
2 * IPv6 output functions
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 *
8 * $Id: ip6_output.c,v 1.34 2002/02/01 22:01:04 davem Exp $
9 *
10 * Based on linux/net/ipv4/ip_output.c
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version
15 * 2 of the License, or (at your option) any later version.
16 *
17 * Changes:
18 * A.N.Kuznetsov : airthmetics in fragmentation.
19 * extension headers are implemented.
20 * route changes now work.
21 * ip6_forward does not confuse sniffers.
22 * etc.
23 *
24 * H. von Brand : Added missing #include <linux/string.h>
25 * Imran Patel : frag id should be in NBO
26 * Kazunori MIYAZAWA @USAGI
27 * : add ip6_append_data and related functions
28 * for datagram xmit
29 */
30
1da177e4
LT		 31#include <linux/errno.h>
32#include <linux/types.h>
33#include <linux/string.h>
34#include <linux/socket.h>
35#include <linux/net.h>
36#include <linux/netdevice.h>
37#include <linux/if_arp.h>
38#include <linux/in6.h>
39#include <linux/tcp.h>
40#include <linux/route.h>
b59f45d0 41#include <linux/module.h>
1da177e4
LT		 42
43#include <linux/netfilter.h>
44#include <linux/netfilter_ipv6.h>
45
46#include <net/sock.h>
47#include <net/snmp.h>
48
49#include <net/ipv6.h>
50#include <net/ndisc.h>
51#include <net/protocol.h>
52#include <net/ip6_route.h>
53#include <net/addrconf.h>
54#include <net/rawv6.h>
55#include <net/icmp.h>
56#include <net/xfrm.h>
57#include <net/checksum.h>
58
59static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *));
60
61static __inline__ void ipv6_select_ident(struct sk_buff *skb, struct frag_hdr *fhdr)
62{
63 static u32 ipv6_fragmentation_id = 1;
64 static DEFINE_SPINLOCK(ip6_id_lock);
65
66 spin_lock_bh(&ip6_id_lock);
67 fhdr->identification = htonl(ipv6_fragmentation_id);
68 if (++ipv6_fragmentation_id == 0)
69 ipv6_fragmentation_id = 1;
70 spin_unlock_bh(&ip6_id_lock);
71}
72
73static inline int ip6_output_finish(struct sk_buff *skb)
74{
75
76 struct dst_entry *dst = skb->dst;
77 struct hh_cache *hh = dst->hh;
78
79 if (hh) {
80 int hh_alen;
81
82 read_lock_bh(&hh->hh_lock);
83 hh_alen = HH_DATA_ALIGN(hh->hh_len);
84 memcpy(skb->data - hh_alen, hh->hh_data, hh_alen);
85 read_unlock_bh(&hh->hh_lock);
86 skb_push(skb, hh->hh_len);
87 return hh->hh_output(skb);
88 } else if (dst->neighbour)
89 return dst->neighbour->output(skb);
90
91 IP6_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
92 kfree_skb(skb);
93 return -EINVAL;
94
95}
96
97/* dev_loopback_xmit for use with netfilter. */
98static int ip6_dev_loopback_xmit(struct sk_buff *newskb)
99{
100 newskb->mac.raw = newskb->data;
101 __skb_pull(newskb, newskb->nh.raw - newskb->data);
102 newskb->pkt_type = PACKET_LOOPBACK;
103 newskb->ip_summed = CHECKSUM_UNNECESSARY;
104 BUG_TRAP(newskb->dst);
105
106 netif_rx(newskb);
107 return 0;
108}
109
110
111static int ip6_output2(struct sk_buff *skb)
112{
113 struct dst_entry *dst = skb->dst;
114 struct net_device *dev = dst->dev;
115
116 skb->protocol = htons(ETH_P_IPV6);
117 skb->dev = dev;
118
119 if (ipv6_addr_is_multicast(&skb->nh.ipv6h->daddr)) {
120 struct ipv6_pinfo* np = skb->sk ? inet6_sk(skb->sk) : NULL;
121
122 if (!(dev->flags & IFF_LOOPBACK) && (!np || np->mc_loop) &&
123 ipv6_chk_mcast_addr(dev, &skb->nh.ipv6h->daddr,
124 &skb->nh.ipv6h->saddr)) {
125 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
126
127 /* Do not check for IFF_ALLMULTI; multicast routing
128 is not supported in any case.
129 */
130 if (newskb)
131 NF_HOOK(PF_INET6, NF_IP6_POST_ROUTING, newskb, NULL,
132 newskb->dev,
133 ip6_dev_loopback_xmit);
134
135 if (skb->nh.ipv6h->hop_limit == 0) {
136 IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
137 kfree_skb(skb);
138 return 0;
139 }
140 }
141
142 IP6_INC_STATS(IPSTATS_MIB_OUTMCASTPKTS);
143 }
144
145 return NF_HOOK(PF_INET6, NF_IP6_POST_ROUTING, skb,NULL, skb->dev,ip6_output_finish);
146}
147
148int ip6_output(struct sk_buff *skb)
149{
89114afd 150 if ((skb->len > dst_mtu(skb->dst) && !skb_is_gso(skb)) ||
e89e9cf5 151 dst_allfrag(skb->dst))
1da177e4
LT		 152 return ip6_fragment(skb, ip6_output2);
153 else
154 return ip6_output2(skb);
155}
156
1da177e4
LT		 157/*
158 * xmit an sk_buff (used by TCP)
159 */
160
161int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl,
162 struct ipv6_txoptions *opt, int ipfragok)
163{
b30bd282 164 struct ipv6_pinfo *np = inet6_sk(sk);
1da177e4
LT		 165 struct in6_addr *first_hop = &fl->fl6_dst;
166 struct dst_entry *dst = skb->dst;
167 struct ipv6hdr *hdr;
168 u8 proto = fl->proto;
169 int seg_len = skb->len;
41a1f8ea 170 int hlimit, tclass;
1da177e4
LT		 171 u32 mtu;
172
173 if (opt) {
174 int head_room;
175
176 /* First: exthdrs may take lots of space (~8K for now)
177 MAX_HEADER is not enough.
178 */
179 head_room = opt->opt_nflen + opt->opt_flen;
180 seg_len += head_room;
181 head_room += sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev);
182
183 if (skb_headroom(skb) < head_room) {
184 struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room);
185 kfree_skb(skb);
186 skb = skb2;
187 if (skb == NULL) {
188 IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
189 return -ENOBUFS;
190 }
191 if (sk)
192 skb_set_owner_w(skb, sk);
193 }
194 if (opt->opt_flen)
195 ipv6_push_frag_opts(skb, opt, &proto);
196 if (opt->opt_nflen)
197 ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop);
198 }
199
200 hdr = skb->nh.ipv6h = (struct ipv6hdr*)skb_push(skb, sizeof(struct ipv6hdr));
201
202 /*
203 * Fill in the IPv6 header
204 */
205
1da177e4
LT		 206 hlimit = -1;
207 if (np)
208 hlimit = np->hop_limit;
209 if (hlimit < 0)
210 hlimit = dst_metric(dst, RTAX_HOPLIMIT);
211 if (hlimit < 0)
212 hlimit = ipv6_get_hoplimit(dst->dev);
213
41a1f8ea
YH		 214 tclass = -1;
215 if (np)
216 tclass = np->tclass;
217 if (tclass < 0)
218 tclass = 0;
219
220 *(u32 *)hdr = htonl(0x60000000 | (tclass << 20)) | fl->fl6_flowlabel;
221
1da177e4
LT		 222 hdr->payload_len = htons(seg_len);
223 hdr->nexthdr = proto;
224 hdr->hop_limit = hlimit;
225
226 ipv6_addr_copy(&hdr->saddr, &fl->fl6_src);
227 ipv6_addr_copy(&hdr->daddr, first_hop);
228
a2c2064f
PM		 229 skb->priority = sk->sk_priority;
230
1da177e4 231 mtu = dst_mtu(dst);
89114afd 232 if ((skb->len <= mtu) || ipfragok || skb_is_gso(skb)) {
1da177e4 233 IP6_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
6869c4d8
HW		 234 return NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev,
235 dst_output);
1da177e4
LT		 236 }
237
238 if (net_ratelimit())
239 printk(KERN_DEBUG "IPv6: sending pkt_too_big to self\n");
240 skb->dev = dst->dev;
241 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev);
242 IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
243 kfree_skb(skb);
244 return -EMSGSIZE;
245}
246
247/*
248 * To avoid extra problems ND packets are send through this
249 * routine. It's code duplication but I really want to avoid
250 * extra checks since ipv6_build_header is used by TCP (which
251 * is for us performance critical)
252 */
253
254int ip6_nd_hdr(struct sock *sk, struct sk_buff *skb, struct net_device *dev,
255 struct in6_addr *saddr, struct in6_addr *daddr,
256 int proto, int len)
257{
258 struct ipv6_pinfo *np = inet6_sk(sk);
259 struct ipv6hdr *hdr;
260 int totlen;
261
262 skb->protocol = htons(ETH_P_IPV6);
263 skb->dev = dev;
264
265 totlen = len + sizeof(struct ipv6hdr);
266
267 hdr = (struct ipv6hdr *) skb_put(skb, sizeof(struct ipv6hdr));
268 skb->nh.ipv6h = hdr;
269
270 *(u32*)hdr = htonl(0x60000000);
271
272 hdr->payload_len = htons(len);
273 hdr->nexthdr = proto;
274 hdr->hop_limit = np->hop_limit;
275
276 ipv6_addr_copy(&hdr->saddr, saddr);
277 ipv6_addr_copy(&hdr->daddr, daddr);
278
279 return 0;
280}
281
282static int ip6_call_ra_chain(struct sk_buff *skb, int sel)
283{
284 struct ip6_ra_chain *ra;
285 struct sock *last = NULL;
286
287 read_lock(&ip6_ra_lock);
288 for (ra = ip6_ra_chain; ra; ra = ra->next) {
289 struct sock *sk = ra->sk;
0bd1b59b
AM		 290 if (sk && ra->sel == sel &&
291 (!sk->sk_bound_dev_if ||
292 sk->sk_bound_dev_if == skb->dev->ifindex)) {
1da177e4
LT		 293 if (last) {
294 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
295 if (skb2)
296 rawv6_rcv(last, skb2);
297 }
298 last = sk;
299 }
300 }
301
302 if (last) {
303 rawv6_rcv(last, skb);
304 read_unlock(&ip6_ra_lock);
305 return 1;
306 }
307 read_unlock(&ip6_ra_lock);
308 return 0;
309}
310
311static inline int ip6_forward_finish(struct sk_buff *skb)
312{
313 return dst_output(skb);
314}
315
316int ip6_forward(struct sk_buff *skb)
317{
318 struct dst_entry *dst = skb->dst;
319 struct ipv6hdr *hdr = skb->nh.ipv6h;
320 struct inet6_skb_parm *opt = IP6CB(skb);
321
322 if (ipv6_devconf.forwarding == 0)
323 goto error;
324
325 if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) {
326 IP6_INC_STATS(IPSTATS_MIB_INDISCARDS);
327 goto drop;
328 }
329
330 skb->ip_summed = CHECKSUM_NONE;
331
332 /*
333 * We DO NOT make any processing on
334 * RA packets, pushing them to user level AS IS
335 * without ane WARRANTY that application will be able
336 * to interpret them. The reason is that we
337 * cannot make anything clever here.
338 *
339 * We are not end-node, so that if packet contains
340 * AH/ESP, we cannot make anything.
341 * Defragmentation also would be mistake, RA packets
342 * cannot be fragmented, because there is no warranty
343 * that different fragments will go along one path. --ANK
344 */
345 if (opt->ra) {
346 u8 *ptr = skb->nh.raw + opt->ra;
347 if (ip6_call_ra_chain(skb, (ptr[2]<<8) + ptr[3]))
348 return 0;
349 }
350
351 /*
352 * check and decrement ttl
353 */
354 if (hdr->hop_limit <= 1) {
355 /* Force OUTPUT device used as source address */
356 skb->dev = dst->dev;
357 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
358 0, skb->dev);
359
360 kfree_skb(skb);
361 return -ETIMEDOUT;
362 }
363
364 if (!xfrm6_route_forward(skb)) {
365 IP6_INC_STATS(IPSTATS_MIB_INDISCARDS);
366 goto drop;
367 }
368 dst = skb->dst;
369
370 /* IPv6 specs say nothing about it, but it is clear that we cannot
371 send redirects to source routed frames.
372 */
373 if (skb->dev == dst->dev && dst->neighbour && opt->srcrt == 0) {
374 struct in6_addr *target = NULL;
375 struct rt6_info *rt;
376 struct neighbour *n = dst->neighbour;
377
378 /*
379 * incoming and outgoing devices are the same
380 * send a redirect.
381 */
382
383 rt = (struct rt6_info *) dst;
384 if ((rt->rt6i_flags & RTF_GATEWAY))
385 target = (struct in6_addr*)&n->primary_key;
386 else
387 target = &hdr->daddr;
388
389 /* Limit redirects both by destination (here)
390 and by source (inside ndisc_send_redirect)
391 */
392 if (xrlim_allow(dst, 1*HZ))
393 ndisc_send_redirect(skb, n, target);
394 } else if (ipv6_addr_type(&hdr->saddr)&(IPV6_ADDR_MULTICAST|IPV6_ADDR_LOOPBACK
395 |IPV6_ADDR_LINKLOCAL)) {
396 /* This check is security critical. */
397 goto error;
398 }
399
400 if (skb->len > dst_mtu(dst)) {
401 /* Again, force OUTPUT device used as source address */
402 skb->dev = dst->dev;
403 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, dst_mtu(dst), skb->dev);
404 IP6_INC_STATS_BH(IPSTATS_MIB_INTOOBIGERRORS);
405 IP6_INC_STATS_BH(IPSTATS_MIB_FRAGFAILS);
406 kfree_skb(skb);
407 return -EMSGSIZE;
408 }
409
410 if (skb_cow(skb, dst->dev->hard_header_len)) {
411 IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
412 goto drop;
413 }
414
415 hdr = skb->nh.ipv6h;
416
417 /* Mangling hops number delayed to point after skb COW */
418
419 hdr->hop_limit--;
420
421 IP6_INC_STATS_BH(IPSTATS_MIB_OUTFORWDATAGRAMS);
422 return NF_HOOK(PF_INET6,NF_IP6_FORWARD, skb, skb->dev, dst->dev, ip6_forward_finish);
423
424error:
425 IP6_INC_STATS_BH(IPSTATS_MIB_INADDRERRORS);
426drop:
427 kfree_skb(skb);
428 return -EINVAL;
429}
430
431static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from)
432{
433 to->pkt_type = from->pkt_type;
434 to->priority = from->priority;
435 to->protocol = from->protocol;
1da177e4
LT		 436 dst_release(to->dst);
437 to->dst = dst_clone(from->dst);
438 to->dev = from->dev;
439
440#ifdef CONFIG_NET_SCHED
441 to->tc_index = from->tc_index;
442#endif
443#ifdef CONFIG_NETFILTER
444 to->nfmark = from->nfmark;
445 /* Connection association is same as pre-frag packet */
9fb9cbb1 446 nf_conntrack_put(to->nfct);
1da177e4
LT		 447 to->nfct = from->nfct;
448 nf_conntrack_get(to->nfct);
449 to->nfctinfo = from->nfctinfo;
9fb9cbb1
YK		 450#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
451 nf_conntrack_put_reasm(to->nfct_reasm);
452 to->nfct_reasm = from->nfct_reasm;
453 nf_conntrack_get_reasm(to->nfct_reasm);
454#endif
1da177e4
LT		 455#ifdef CONFIG_BRIDGE_NETFILTER
456 nf_bridge_put(to->nf_bridge);
457 to->nf_bridge = from->nf_bridge;
458 nf_bridge_get(to->nf_bridge);
459#endif
1da177e4 460#endif
984bc16c 461 skb_copy_secmark(to, from);
1da177e4
LT		 462}
463
464int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
465{
466 u16 offset = sizeof(struct ipv6hdr);
467 struct ipv6_opt_hdr *exthdr = (struct ipv6_opt_hdr*)(skb->nh.ipv6h + 1);
468 unsigned int packet_len = skb->tail - skb->nh.raw;
469 int found_rhdr = 0;
470 *nexthdr = &skb->nh.ipv6h->nexthdr;
471
472 while (offset + 1 <= packet_len) {
473
474 switch (**nexthdr) {
475
476 case NEXTHDR_HOP:
477 case NEXTHDR_ROUTING:
478 case NEXTHDR_DEST:
479 if (**nexthdr == NEXTHDR_ROUTING) found_rhdr = 1;
480 if (**nexthdr == NEXTHDR_DEST && found_rhdr) return offset;
481 offset += ipv6_optlen(exthdr);
482 *nexthdr = &exthdr->nexthdr;
483 exthdr = (struct ipv6_opt_hdr*)(skb->nh.raw + offset);
484 break;
485 default :
486 return offset;
487 }
488 }
489
490 return offset;
491}
b59f45d0 492EXPORT_SYMBOL_GPL(ip6_find_1stfragopt);
1da177e4
LT		 493
494static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
495{
496 struct net_device *dev;
497 struct sk_buff *frag;
498 struct rt6_info *rt = (struct rt6_info*)skb->dst;
d91675f9 499 struct ipv6_pinfo *np = skb->sk ? inet6_sk(skb->sk) : NULL;
1da177e4
LT		 500 struct ipv6hdr *tmp_hdr;
501 struct frag_hdr *fh;
502 unsigned int mtu, hlen, left, len;
503 u32 frag_id = 0;
504 int ptr, offset = 0, err=0;
505 u8 *prevhdr, nexthdr = 0;
506
507 dev = rt->u.dst.dev;
508 hlen = ip6_find_1stfragopt(skb, &prevhdr);
509 nexthdr = *prevhdr;
510
d91675f9
YH		 511 mtu = dst_mtu(&rt->u.dst);
512 if (np && np->frag_size < mtu) {
513 if (np->frag_size)
514 mtu = np->frag_size;
515 }
516 mtu -= hlen + sizeof(struct frag_hdr);
1da177e4
LT		 517
518 if (skb_shinfo(skb)->frag_list) {
519 int first_len = skb_pagelen(skb);
520
521 if (first_len - hlen > mtu ||
522 ((first_len - hlen) & 7) ||
523 skb_cloned(skb))
524 goto slow_path;
525
526 for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) {
527 /* Correct geometry. */
528 if (frag->len > mtu ||
529 ((frag->len & 7) && frag->next) ||
530 skb_headroom(frag) < hlen)
531 goto slow_path;
532
1da177e4
LT		 533 /* Partially cloned skb? */
534 if (skb_shared(frag))
535 goto slow_path;
2fdba6b0
HX		 536
537 BUG_ON(frag->sk);
538 if (skb->sk) {
539 sock_hold(skb->sk);
540 frag->sk = skb->sk;
541 frag->destructor = sock_wfree;
542 skb->truesize -= frag->truesize;
543 }
1da177e4
LT		 544 }
545
546 err = 0;
547 offset = 0;
548 frag = skb_shinfo(skb)->frag_list;
549 skb_shinfo(skb)->frag_list = NULL;
550 /* BUILD HEADER */
551
552 tmp_hdr = kmalloc(hlen, GFP_ATOMIC);
553 if (!tmp_hdr) {
554 IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
555 return -ENOMEM;
556 }
557
558 *prevhdr = NEXTHDR_FRAGMENT;
559 memcpy(tmp_hdr, skb->nh.raw, hlen);
560 __skb_pull(skb, hlen);
561 fh = (struct frag_hdr*)__skb_push(skb, sizeof(struct frag_hdr));
562 skb->nh.raw = __skb_push(skb, hlen);
563 memcpy(skb->nh.raw, tmp_hdr, hlen);
564
565 ipv6_select_ident(skb, fh);
566 fh->nexthdr = nexthdr;
567 fh->reserved = 0;
568 fh->frag_off = htons(IP6_MF);
569 frag_id = fh->identification;
570
571 first_len = skb_pagelen(skb);
572 skb->data_len = first_len - skb_headlen(skb);
573 skb->len = first_len;
574 skb->nh.ipv6h->payload_len = htons(first_len - sizeof(struct ipv6hdr));
575
576
577 for (;;) {
578 /* Prepare header of the next frame,
579 * before previous one went down. */
580 if (frag) {
581 frag->ip_summed = CHECKSUM_NONE;
582 frag->h.raw = frag->data;
583 fh = (struct frag_hdr*)__skb_push(frag, sizeof(struct frag_hdr));
584 frag->nh.raw = __skb_push(frag, hlen);
585 memcpy(frag->nh.raw, tmp_hdr, hlen);
586 offset += skb->len - hlen - sizeof(struct frag_hdr);
587 fh->nexthdr = nexthdr;
588 fh->reserved = 0;
589 fh->frag_off = htons(offset);
590 if (frag->next != NULL)
591 fh->frag_off |= htons(IP6_MF);
592 fh->identification = frag_id;
593 frag->nh.ipv6h->payload_len = htons(frag->len - sizeof(struct ipv6hdr));
594 ip6_copy_metadata(frag, skb);
595 }
596
597 err = output(skb);
598 if (err || !frag)
599 break;
600
601 skb = frag;
602 frag = skb->next;
603 skb->next = NULL;
604 }
605
a51482bd 606 kfree(tmp_hdr);
1da177e4
LT		 607
608 if (err == 0) {
609 IP6_INC_STATS(IPSTATS_MIB_FRAGOKS);
610 return 0;
611 }
612
613 while (frag) {
614 skb = frag->next;
615 kfree_skb(frag);
616 frag = skb;
617 }
618
619 IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
620 return err;
621 }
622
623slow_path:
624 left = skb->len - hlen; /* Space per frame */
625 ptr = hlen; /* Where to start from */
626
627 /*
628 * Fragment the datagram.
629 */
630
631 *prevhdr = NEXTHDR_FRAGMENT;
632
633 /*
634 * Keep copying data until we run out.
635 */
636 while(left > 0) {
637 len = left;
638 /* IF: it doesn't fit, use 'mtu' - the data space left */
639 if (len > mtu)
640 len = mtu;
641 /* IF: we are not sending upto and including the packet end
642 then align the next start on an eight byte boundary */
643 if (len < left) {
644 len &= ~7;
645 }
646 /*
647 * Allocate buffer.
648 */
649
650 if ((frag = alloc_skb(len+hlen+sizeof(struct frag_hdr)+LL_RESERVED_SPACE(rt->u.dst.dev), GFP_ATOMIC)) == NULL) {
64ce2073 651 NETDEBUG(KERN_INFO "IPv6: frag: no memory for new fragment!\n");
1da177e4
LT		 652 IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
653 err = -ENOMEM;
654 goto fail;
655 }
656
657 /*
658 * Set up data on packet
659 */
660
661 ip6_copy_metadata(frag, skb);
662 skb_reserve(frag, LL_RESERVED_SPACE(rt->u.dst.dev));
663 skb_put(frag, len + hlen + sizeof(struct frag_hdr));
664 frag->nh.raw = frag->data;
665 fh = (struct frag_hdr*)(frag->data + hlen);
666 frag->h.raw = frag->data + hlen + sizeof(struct frag_hdr);
667
668 /*
669 * Charge the memory for the fragment to any owner
670 * it might possess
671 */
672 if (skb->sk)
673 skb_set_owner_w(frag, skb->sk);
674
675 /*
676 * Copy the packet header into the new buffer.
677 */
678 memcpy(frag->nh.raw, skb->data, hlen);
679
680 /*
681 * Build fragment header.
682 */
683 fh->nexthdr = nexthdr;
684 fh->reserved = 0;
f36d6ab1 685 if (!frag_id) {
1da177e4
LT		 686 ipv6_select_ident(skb, fh);
687 frag_id = fh->identification;
688 } else
689 fh->identification = frag_id;
690
691 /*
692 * Copy a block of the IP datagram.
693 */
694 if (skb_copy_bits(skb, ptr, frag->h.raw, len))
695 BUG();
696 left -= len;
697
698 fh->frag_off = htons(offset);
699 if (left > 0)
700 fh->frag_off |= htons(IP6_MF);
701 frag->nh.ipv6h->payload_len = htons(frag->len - sizeof(struct ipv6hdr));
702
703 ptr += len;
704 offset += len;
705
706 /*
707 * Put this fragment into the sending queue.
708 */
709
710 IP6_INC_STATS(IPSTATS_MIB_FRAGCREATES);
711
712 err = output(frag);
713 if (err)
714 goto fail;
715 }
716 kfree_skb(skb);
717 IP6_INC_STATS(IPSTATS_MIB_FRAGOKS);
718 return err;
719
720fail:
721 kfree_skb(skb);
722 IP6_INC_STATS(IPSTATS_MIB_FRAGFAILS);
723 return err;
724}
725
726int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl)
727{
728 int err = 0;
729
730 *dst = NULL;
731 if (sk) {
732 struct ipv6_pinfo *np = inet6_sk(sk);
733
734 *dst = sk_dst_check(sk, np->dst_cookie);
735 if (*dst) {
736 struct rt6_info *rt = (struct rt6_info*)*dst;
737
d76e60a5
DM		 738 /* Yes, checking route validity in not connected
739 * case is not very simple. Take into account,
740 * that we do not support routing by source, TOS,
741 * and MSG_DONTROUTE --ANK (980726)
742 *
743 * 1. If route was host route, check that
744 * cached destination is current.
745 * If it is network route, we still may
746 * check its validity using saved pointer
747 * to the last used address: daddr_cache.
748 * We do not want to save whole address now,
749 * (because main consumer of this service
750 * is tcp, which has not this problem),
751 * so that the last trick works only on connected
752 * sockets.
753 * 2. oif also should be the same.
754 */
1da177e4 755 if (((rt->rt6i_dst.plen != 128 ||
d76e60a5
DM		 756 !ipv6_addr_equal(&fl->fl6_dst,
757 &rt->rt6i_dst.addr))
1da177e4 758 && (np->daddr_cache == NULL ||
d76e60a5
DM		 759 !ipv6_addr_equal(&fl->fl6_dst,
760 np->daddr_cache)))
1da177e4
LT		 761 || (fl->oif && fl->oif != (*dst)->dev->ifindex)) {
762 dst_release(*dst);
763 *dst = NULL;
764 }
765 }
766 }
767
768 if (*dst == NULL)
769 *dst = ip6_route_output(sk, fl);
770
771 if ((err = (*dst)->error))
772 goto out_err_release;
773
774 if (ipv6_addr_any(&fl->fl6_src)) {
775 err = ipv6_get_saddr(*dst, &fl->fl6_dst, &fl->fl6_src);
776
44456d37 777 if (err)
1da177e4 778 goto out_err_release;
1da177e4
LT		 779 }
780
781 return 0;
782
783out_err_release:
784 dst_release(*dst);
785 *dst = NULL;
786 return err;
787}
34a0b3cd 788
3cf3dc6c
ACM		 789EXPORT_SYMBOL_GPL(ip6_dst_lookup);
790
34a0b3cd 791static inline int ip6_ufo_append_data(struct sock *sk,
e89e9cf5
AR		 792 int getfrag(void *from, char *to, int offset, int len,
793 int odd, struct sk_buff *skb),
794 void *from, int length, int hh_len, int fragheaderlen,
795 int transhdrlen, int mtu,unsigned int flags)
796
797{
798 struct sk_buff *skb;
799 int err;
800
801 /* There is support for UDP large send offload by network
802 * device, so create one single skb packet containing complete
803 * udp datagram
804 */
805 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) {
806 skb = sock_alloc_send_skb(sk,
807 hh_len + fragheaderlen + transhdrlen + 20,
808 (flags & MSG_DONTWAIT), &err);
809 if (skb == NULL)
810 return -ENOMEM;
811
812 /* reserve space for Hardware header */
813 skb_reserve(skb, hh_len);
814
815 /* create space for UDP/IP header */
816 skb_put(skb,fragheaderlen + transhdrlen);
817
818 /* initialize network header pointer */
819 skb->nh.raw = skb->data;
820
821 /* initialize protocol header pointer */
822 skb->h.raw = skb->data + fragheaderlen;
823
824 skb->ip_summed = CHECKSUM_HW;
825 skb->csum = 0;
826 sk->sk_sndmsg_off = 0;
827 }
828
829 err = skb_append_datato_frags(sk,skb, getfrag, from,
830 (length - transhdrlen));
831 if (!err) {
832 struct frag_hdr fhdr;
833
834 /* specify the length of each IP datagram fragment*/
7967168c
HX		 835 skb_shinfo(skb)->gso_size = mtu - fragheaderlen -
836 sizeof(struct frag_hdr);
f83ef8c0 837 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
e89e9cf5
AR		 838 ipv6_select_ident(skb, &fhdr);
839 skb_shinfo(skb)->ip6_frag_id = fhdr.identification;
840 __skb_queue_tail(&sk->sk_write_queue, skb);
841
842 return 0;
843 }
844 /* There is not enough support do UPD LSO,
845 * so follow normal path
846 */
847 kfree_skb(skb);
848
849 return err;
850}
1da177e4 851
41a1f8ea
YH		 852int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
853 int offset, int len, int odd, struct sk_buff *skb),
854 void *from, int length, int transhdrlen,
855 int hlimit, int tclass, struct ipv6_txoptions *opt, struct flowi *fl,
856 struct rt6_info *rt, unsigned int flags)
1da177e4
LT		 857{
858 struct inet_sock *inet = inet_sk(sk);
859 struct ipv6_pinfo *np = inet6_sk(sk);
860 struct sk_buff *skb;
861 unsigned int maxfraglen, fragheaderlen;
862 int exthdrlen;
863 int hh_len;
864 int mtu;
865 int copy;
866 int err;
867 int offset = 0;
868 int csummode = CHECKSUM_NONE;
869
870 if (flags&MSG_PROBE)
871 return 0;
872 if (skb_queue_empty(&sk->sk_write_queue)) {
873 /*
874 * setup for corking
875 */
876 if (opt) {
877 if (np->cork.opt == NULL) {
878 np->cork.opt = kmalloc(opt->tot_len,
879 sk->sk_allocation);
880 if (unlikely(np->cork.opt == NULL))
881 return -ENOBUFS;
882 } else if (np->cork.opt->tot_len < opt->tot_len) {
883 printk(KERN_DEBUG "ip6_append_data: invalid option length\n");
884 return -EINVAL;
885 }
886 memcpy(np->cork.opt, opt, opt->tot_len);
887 inet->cork.flags |= IPCORK_OPT;
888 /* need source address above miyazawa*/
889 }
890 dst_hold(&rt->u.dst);
891 np->cork.rt = rt;
892 inet->cork.fl = *fl;
893 np->cork.hop_limit = hlimit;
41a1f8ea 894 np->cork.tclass = tclass;
d91675f9 895 mtu = dst_mtu(rt->u.dst.path);
c7503609 896 if (np->frag_size < mtu) {
d91675f9
YH		 897 if (np->frag_size)
898 mtu = np->frag_size;
899 }
900 inet->cork.fragsize = mtu;
1da177e4
LT		 901 if (dst_allfrag(rt->u.dst.path))
902 inet->cork.flags |= IPCORK_ALLFRAG;
903 inet->cork.length = 0;
904 sk->sk_sndmsg_page = NULL;
905 sk->sk_sndmsg_off = 0;
906 exthdrlen = rt->u.dst.header_len + (opt ? opt->opt_flen : 0);
907 length += exthdrlen;
908 transhdrlen += exthdrlen;
909 } else {
910 rt = np->cork.rt;
911 fl = &inet->cork.fl;
912 if (inet->cork.flags & IPCORK_OPT)
913 opt = np->cork.opt;
914 transhdrlen = 0;
915 exthdrlen = 0;
916 mtu = inet->cork.fragsize;
917 }
918
919 hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);
920
921 fragheaderlen = sizeof(struct ipv6hdr) + (opt ? opt->opt_nflen : 0);
922 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr);
923
924 if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) {
925 if (inet->cork.length + length > sizeof(struct ipv6hdr) + IPV6_MAXPLEN - fragheaderlen) {
926 ipv6_local_error(sk, EMSGSIZE, fl, mtu-exthdrlen);
927 return -EMSGSIZE;
928 }
929 }
930
931 /*
932 * Let's try using as much space as possible.
933 * Use MTU if total length of the message fits into the MTU.
934 * Otherwise, we need to reserve fragment header and
935 * fragment alignment (= 8-15 octects, in total).
936 *
937 * Note that we may need to "move" the data from the tail of
938 * of the buffer to the new fragment when we split
939 * the message.
940 *
941 * FIXME: It may be fragmented into multiple chunks
942 * at once if non-fragmentable extension headers
943 * are too large.
944 * --yoshfuji
945 */
946
947 inet->cork.length += length;
e89e9cf5
AR		 948 if (((length > mtu) && (sk->sk_protocol == IPPROTO_UDP)) &&
949 (rt->u.dst.dev->features & NETIF_F_UFO)) {
950
baa829d8
PM		 951 err = ip6_ufo_append_data(sk, getfrag, from, length, hh_len,
952 fragheaderlen, transhdrlen, mtu,
953 flags);
954 if (err)
e89e9cf5 955 goto error;
e89e9cf5
AR		 956 return 0;
957 }
1da177e4
LT		 958
959 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL)
960 goto alloc_new_skb;
961
962 while (length > 0) {
963 /* Check if the remaining data fits into current packet. */
964 copy = (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;
965 if (copy < length)
966 copy = maxfraglen - skb->len;
967
968 if (copy <= 0) {
969 char *data;
970 unsigned int datalen;
971 unsigned int fraglen;
972 unsigned int fraggap;
973 unsigned int alloclen;
974 struct sk_buff *skb_prev;
975alloc_new_skb:
976 skb_prev = skb;
977
978 /* There's no room in the current skb */
979 if (skb_prev)
980 fraggap = skb_prev->len - maxfraglen;
981 else
982 fraggap = 0;
983
984 /*
985 * If remaining data exceeds the mtu,
986 * we know we need more fragment(s).
987 */
988 datalen = length + fraggap;
989 if (datalen > (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
990 datalen = maxfraglen - fragheaderlen;
991
992 fraglen = datalen + fragheaderlen;
993 if ((flags & MSG_MORE) &&
994 !(rt->u.dst.dev->features&NETIF_F_SG))
995 alloclen = mtu;
996 else
997 alloclen = datalen + fragheaderlen;
998
999 /*
1000 * The last fragment gets additional space at tail.
1001 * Note: we overallocate on fragments with MSG_MODE
1002 * because we have no idea if we're the last one.
1003 */
1004 if (datalen == length + fraggap)
1005 alloclen += rt->u.dst.trailer_len;
1006
1007 /*
1008 * We just reserve space for fragment header.
1009 * Note: this may be overallocation if the message
1010 * (without MSG_MORE) fits into the MTU.
1011 */
1012 alloclen += sizeof(struct frag_hdr);
1013
1014 if (transhdrlen) {
1015 skb = sock_alloc_send_skb(sk,
1016 alloclen + hh_len,
1017 (flags & MSG_DONTWAIT), &err);
1018 } else {
1019 skb = NULL;
1020 if (atomic_read(&sk->sk_wmem_alloc) <=
1021 2 * sk->sk_sndbuf)
1022 skb = sock_wmalloc(sk,
1023 alloclen + hh_len, 1,
1024 sk->sk_allocation);
1025 if (unlikely(skb == NULL))
1026 err = -ENOBUFS;
1027 }
1028 if (skb == NULL)
1029 goto error;
1030 /*
1031 * Fill in the control structures
1032 */
1033 skb->ip_summed = csummode;
1034 skb->csum = 0;
1035 /* reserve for fragmentation */
1036 skb_reserve(skb, hh_len+sizeof(struct frag_hdr));
1037
1038 /*
1039 * Find where to start putting bytes
1040 */
1041 data = skb_put(skb, fraglen);
1042 skb->nh.raw = data + exthdrlen;
1043 data += fragheaderlen;
1044 skb->h.raw = data + exthdrlen;
1045
1046 if (fraggap) {
1047 skb->csum = skb_copy_and_csum_bits(
1048 skb_prev, maxfraglen,
1049 data + transhdrlen, fraggap, 0);
1050 skb_prev->csum = csum_sub(skb_prev->csum,
1051 skb->csum);
1052 data += fraggap;
1053 skb_trim(skb_prev, maxfraglen);
1054 }
1055 copy = datalen - transhdrlen - fraggap;
1056 if (copy < 0) {
1057 err = -EINVAL;
1058 kfree_skb(skb);
1059 goto error;
1060 } else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) {
1061 err = -EFAULT;
1062 kfree_skb(skb);
1063 goto error;
1064 }
1065
1066 offset += copy;
1067 length -= datalen - fraggap;
1068 transhdrlen = 0;
1069 exthdrlen = 0;
1070 csummode = CHECKSUM_NONE;
1071
1072 /*
1073 * Put the packet on the pending queue
1074 */
1075 __skb_queue_tail(&sk->sk_write_queue, skb);
1076 continue;
1077 }
1078
1079 if (copy > length)
1080 copy = length;
1081
1082 if (!(rt->u.dst.dev->features&NETIF_F_SG)) {
1083 unsigned int off;
1084
1085 off = skb->len;
1086 if (getfrag(from, skb_put(skb, copy),
1087 offset, copy, off, skb) < 0) {
1088 __skb_trim(skb, off);
1089 err = -EFAULT;
1090 goto error;
1091 }
1092 } else {
1093 int i = skb_shinfo(skb)->nr_frags;
1094 skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1];
1095 struct page *page = sk->sk_sndmsg_page;
1096 int off = sk->sk_sndmsg_off;
1097 unsigned int left;
1098
1099 if (page && (left = PAGE_SIZE - off) > 0) {
1100 if (copy >= left)
1101 copy = left;
1102 if (page != frag->page) {
1103 if (i == MAX_SKB_FRAGS) {
1104 err = -EMSGSIZE;
1105 goto error;
1106 }
1107 get_page(page);
1108 skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0);
1109 frag = &skb_shinfo(skb)->frags[i];
1110 }
1111 } else if(i < MAX_SKB_FRAGS) {
1112 if (copy > PAGE_SIZE)
1113 copy = PAGE_SIZE;
1114 page = alloc_pages(sk->sk_allocation, 0);
1115 if (page == NULL) {
1116 err = -ENOMEM;
1117 goto error;
1118 }
1119 sk->sk_sndmsg_page = page;
1120 sk->sk_sndmsg_off = 0;
1121
1122 skb_fill_page_desc(skb, i, page, 0, 0);
1123 frag = &skb_shinfo(skb)->frags[i];
1124 skb->truesize += PAGE_SIZE;
1125 atomic_add(PAGE_SIZE, &sk->sk_wmem_alloc);
1126 } else {
1127 err = -EMSGSIZE;
1128 goto error;
1129 }
1130 if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) {
1131 err = -EFAULT;
1132 goto error;
1133 }
1134 sk->sk_sndmsg_off += copy;
1135 frag->size += copy;
1136 skb->len += copy;
1137 skb->data_len += copy;
1138 }
1139 offset += copy;
1140 length -= copy;
1141 }
1142 return 0;
1143error:
1144 inet->cork.length -= length;
1145 IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
1146 return err;
1147}
1148
1149int ip6_push_pending_frames(struct sock *sk)
1150{
1151 struct sk_buff *skb, *tmp_skb;
1152 struct sk_buff **tail_skb;
1153 struct in6_addr final_dst_buf, *final_dst = &final_dst_buf;
1154 struct inet_sock *inet = inet_sk(sk);
1155 struct ipv6_pinfo *np = inet6_sk(sk);
1156 struct ipv6hdr *hdr;
1157 struct ipv6_txoptions *opt = np->cork.opt;
1158 struct rt6_info *rt = np->cork.rt;
1159 struct flowi *fl = &inet->cork.fl;
1160 unsigned char proto = fl->proto;
1161 int err = 0;
1162
1163 if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL)
1164 goto out;
1165 tail_skb = &(skb_shinfo(skb)->frag_list);
1166
1167 /* move skb->data to ip header from ext header */
1168 if (skb->data < skb->nh.raw)
1169 __skb_pull(skb, skb->nh.raw - skb->data);
1170 while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) {
1171 __skb_pull(tmp_skb, skb->h.raw - skb->nh.raw);
1172 *tail_skb = tmp_skb;
1173 tail_skb = &(tmp_skb->next);
1174 skb->len += tmp_skb->len;
1175 skb->data_len += tmp_skb->len;
1da177e4
LT		 1176 skb->truesize += tmp_skb->truesize;
1177 __sock_put(tmp_skb->sk);
1178 tmp_skb->destructor = NULL;
1179 tmp_skb->sk = NULL;
1da177e4
LT		 1180 }
1181
1182 ipv6_addr_copy(final_dst, &fl->fl6_dst);
1183 __skb_pull(skb, skb->h.raw - skb->nh.raw);
1184 if (opt && opt->opt_flen)
1185 ipv6_push_frag_opts(skb, opt, &proto);
1186 if (opt && opt->opt_nflen)
1187 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst);
1188
1189 skb->nh.ipv6h = hdr = (struct ipv6hdr*) skb_push(skb, sizeof(struct ipv6hdr));
1190
41a1f8ea
YH		 1191 *(u32*)hdr = fl->fl6_flowlabel |
1192 htonl(0x60000000 | ((int)np->cork.tclass << 20));
1da177e4
LT		 1193
1194 if (skb->len <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN)
1195 hdr->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
1196 else
1197 hdr->payload_len = 0;
1198 hdr->hop_limit = np->cork.hop_limit;
1199 hdr->nexthdr = proto;
1200 ipv6_addr_copy(&hdr->saddr, &fl->fl6_src);
1201 ipv6_addr_copy(&hdr->daddr, final_dst);
1202
a2c2064f
PM		 1203 skb->priority = sk->sk_priority;
1204
1da177e4
LT		 1205 skb->dst = dst_clone(&rt->u.dst);
1206 IP6_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
1207 err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, skb->dst->dev, dst_output);
1208 if (err) {
1209 if (err > 0)
3320da89 1210 err = np->recverr ? net_xmit_errno(err) : 0;
1da177e4
LT		 1211 if (err)
1212 goto error;
1213 }
1214
1215out:
1216 inet->cork.flags &= ~IPCORK_OPT;
a51482bd
JJ		 1217 kfree(np->cork.opt);
1218 np->cork.opt = NULL;
1da177e4
LT		 1219 if (np->cork.rt) {
1220 dst_release(&np->cork.rt->u.dst);
1221 np->cork.rt = NULL;
1222 inet->cork.flags &= ~IPCORK_ALLFRAG;
1223 }
1224 memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));
1225 return err;
1226error:
1227 goto out;
1228}
1229
1230void ip6_flush_pending_frames(struct sock *sk)
1231{
1232 struct inet_sock *inet = inet_sk(sk);
1233 struct ipv6_pinfo *np = inet6_sk(sk);
1234 struct sk_buff *skb;
1235
1236 while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) {
1237 IP6_INC_STATS(IPSTATS_MIB_OUTDISCARDS);
1238 kfree_skb(skb);
1239 }
1240
1241 inet->cork.flags &= ~IPCORK_OPT;
1242
a51482bd
JJ		 1243 kfree(np->cork.opt);
1244 np->cork.opt = NULL;
1da177e4
LT		 1245 if (np->cork.rt) {
1246 dst_release(&np->cork.rt->u.dst);
1247 np->cork.rt = NULL;
1248 inet->cork.flags &= ~IPCORK_ALLFRAG;
1249 }
1250 memset(&inet->cork.fl, 0, sizeof(inet->cork.fl));
1251}
Linux 6.x block layer and io_uring tree(s)