?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
ALSA: hda/realtek - Change front mic location for Lenovo M710q
[linux/fpc-iii.git] / net / ipv4 / udp_offload.c
blob0c0522b79b43f09785ce8fd5f0dc9461a93f0e98
1 /*
2 * IPV4 GSO/GRO offload support
3 * Linux INET implementation
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License
7 * as published by the Free Software Foundation; either version
8 * 2 of the License, or (at your option) any later version.
9 *
10 * UDPv4 GSO support
11 */
12
13 #include <linux/skbuff.h>
14 #include <net/udp.h>
15 #include <net/protocol.h>
16
17 static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb,
18 netdev_features_t features,
19 struct sk_buff *(*gso_inner_segment)(struct sk_buff *skb,
20 netdev_features_t features),
21 __be16 new_protocol, bool is_ipv6)
22 {
23 int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb);
24 bool remcsum, need_csum, offload_csum, gso_partial;
25 struct sk_buff *segs = ERR_PTR(-EINVAL);
26 struct udphdr *uh = udp_hdr(skb);
27 u16 mac_offset = skb->mac_header;
28 __be16 protocol = skb->protocol;
29 u16 mac_len = skb->mac_len;
30 int udp_offset, outer_hlen;
31 __wsum partial;
32 bool need_ipsec;
33
34 if (unlikely(!pskb_may_pull(skb, tnl_hlen)))
35 goto out;
36
37 /* Adjust partial header checksum to negate old length.
38 * We cannot rely on the value contained in uh->len as it is
39 * possible that the actual value exceeds the boundaries of the
40 * 16 bit length field due to the header being added outside of an
41 * IP or IPv6 frame that was already limited to 64K - 1.
42 */
43 if (skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL)
44 partial = (__force __wsum)uh->len;
45 else
46 partial = (__force __wsum)htonl(skb->len);
47 partial = csum_sub(csum_unfold(uh->check), partial);
48
49 /* setup inner skb. */
50 skb->encapsulation = 0;
51 SKB_GSO_CB(skb)->encap_level = 0;
52 __skb_pull(skb, tnl_hlen);
53 skb_reset_mac_header(skb);
54 skb_set_network_header(skb, skb_inner_network_offset(skb));
55 skb->mac_len = skb_inner_network_offset(skb);
56 skb->protocol = new_protocol;
57
58 need_csum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM);
59 skb->encap_hdr_csum = need_csum;
60
61 remcsum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TUNNEL_REMCSUM);
62 skb->remcsum_offload = remcsum;
63
64 need_ipsec = skb_dst(skb) && dst_xfrm(skb_dst(skb));
65 /* Try to offload checksum if possible */
66 offload_csum = !!(need_csum &&
67 !need_ipsec &&
68 (skb->dev->features &
69 (is_ipv6 ? (NETIF_F_HW_CSUM | NETIF_F_IPV6_CSUM) :
70 (NETIF_F_HW_CSUM | NETIF_F_IP_CSUM))));
71
72 features &= skb->dev->hw_enc_features;
73
74 /* The only checksum offload we care about from here on out is the
75 * outer one so strip the existing checksum feature flags and
76 * instead set the flag based on our outer checksum offload value.
77 */
78 if (remcsum) {
79 features &= ~NETIF_F_CSUM_MASK;
80 if (!need_csum || offload_csum)
81 features |= NETIF_F_HW_CSUM;
82 }
83
84 /* segment inner packet. */
85 segs = gso_inner_segment(skb, features);
86 if (IS_ERR_OR_NULL(segs)) {
87 skb_gso_error_unwind(skb, protocol, tnl_hlen, mac_offset,
88 mac_len);
89 goto out;
90 }
91
92 gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);
93
94 outer_hlen = skb_tnl_header_len(skb);
95 udp_offset = outer_hlen - tnl_hlen;
96 skb = segs;
97 do {
98 unsigned int len;
99
100 if (remcsum)
101 skb->ip_summed = CHECKSUM_NONE;
102
103 /* Set up inner headers if we are offloading inner checksum */
104 if (skb->ip_summed == CHECKSUM_PARTIAL) {
105 skb_reset_inner_headers(skb);
106 skb->encapsulation = 1;
107 }
108
109 skb->mac_len = mac_len;
110 skb->protocol = protocol;
111
112 __skb_push(skb, outer_hlen);
113 skb_reset_mac_header(skb);
114 skb_set_network_header(skb, mac_len);
115 skb_set_transport_header(skb, udp_offset);
116 len = skb->len - udp_offset;
117 uh = udp_hdr(skb);
118
119 /* If we are only performing partial GSO the inner header
120 * will be using a length value equal to only one MSS sized
121 * segment instead of the entire frame.
122 */
123 if (gso_partial && skb_is_gso(skb)) {
124 uh->len = htons(skb_shinfo(skb)->gso_size +
125 SKB_GSO_CB(skb)->data_offset +
126 skb->head - (unsigned char *)uh);
127 } else {
128 uh->len = htons(len);
129 }
130
131 if (!need_csum)
132 continue;
133
134 uh->check = ~csum_fold(csum_add(partial,
135 (__force __wsum)htonl(len)));
136
137 if (skb->encapsulation || !offload_csum) {
138 uh->check = gso_make_checksum(skb, ~uh->check);
139 if (uh->check == 0)
140 uh->check = CSUM_MANGLED_0;
141 } else {
142 skb->ip_summed = CHECKSUM_PARTIAL;
143 skb->csum_start = skb_transport_header(skb) - skb->head;
144 skb->csum_offset = offsetof(struct udphdr, check);
145 }
146 } while ((skb = skb->next));
147 out:
148 return segs;
149 }
150
151 struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb,
152 netdev_features_t features,
153 bool is_ipv6)
154 {
155 __be16 protocol = skb->protocol;
156 const struct net_offload **offloads;
157 const struct net_offload *ops;
158 struct sk_buff *segs = ERR_PTR(-EINVAL);
159 struct sk_buff *(*gso_inner_segment)(struct sk_buff *skb,
160 netdev_features_t features);
161
162 rcu_read_lock();
163
164 switch (skb->inner_protocol_type) {
165 case ENCAP_TYPE_ETHER:
166 protocol = skb->inner_protocol;
167 gso_inner_segment = skb_mac_gso_segment;
168 break;
169 case ENCAP_TYPE_IPPROTO:
170 offloads = is_ipv6 ? inet6_offloads : inet_offloads;
171 ops = rcu_dereference(offloads[skb->inner_ipproto]);
172 if (!ops || !ops->callbacks.gso_segment)
173 goto out_unlock;
174 gso_inner_segment = ops->callbacks.gso_segment;
175 break;
176 default:
177 goto out_unlock;
178 }
179
180 segs = __skb_udp_tunnel_segment(skb, features, gso_inner_segment,
181 protocol, is_ipv6);
182
183 out_unlock:
184 rcu_read_unlock();
185
186 return segs;
187 }
188 EXPORT_SYMBOL(skb_udp_tunnel_segment);
189
190 struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb,
191 netdev_features_t features)
192 {
193 struct sock *sk = gso_skb->sk;
194 unsigned int sum_truesize = 0;
195 struct sk_buff *segs, *seg;
196 struct udphdr *uh;
197 unsigned int mss;
198 bool copy_dtor;
199 __sum16 check;
200 __be16 newlen;
201
202 mss = skb_shinfo(gso_skb)->gso_size;
203 if (gso_skb->len <= sizeof(*uh) + mss)
204 return ERR_PTR(-EINVAL);
205
206 skb_pull(gso_skb, sizeof(*uh));
207
208 /* clear destructor to avoid skb_segment assigning it to tail */
209 copy_dtor = gso_skb->destructor == sock_wfree;
210 if (copy_dtor)
211 gso_skb->destructor = NULL;
212
213 segs = skb_segment(gso_skb, features);
214 if (unlikely(IS_ERR_OR_NULL(segs))) {
215 if (copy_dtor)
216 gso_skb->destructor = sock_wfree;
217 return segs;
218 }
219
220 /* GSO partial and frag_list segmentation only requires splitting
221 * the frame into an MSS multiple and possibly a remainder, both
222 * cases return a GSO skb. So update the mss now.
223 */
224 if (skb_is_gso(segs))
225 mss *= skb_shinfo(segs)->gso_segs;
226
227 seg = segs;
228 uh = udp_hdr(seg);
229
230 /* compute checksum adjustment based on old length versus new */
231 newlen = htons(sizeof(*uh) + mss);
232 check = csum16_add(csum16_sub(uh->check, uh->len), newlen);
233
234 for (;;) {
235 if (copy_dtor) {
236 seg->destructor = sock_wfree;
237 seg->sk = sk;
238 sum_truesize += seg->truesize;
239 }
240
241 if (!seg->next)
242 break;
243
244 uh->len = newlen;
245 uh->check = check;
246
247 if (seg->ip_summed == CHECKSUM_PARTIAL)
248 gso_reset_checksum(seg, ~check);
249 else
250 uh->check = gso_make_checksum(seg, ~check) ? :
251 CSUM_MANGLED_0;
252
253 seg = seg->next;
254 uh = udp_hdr(seg);
255 }
256
257 /* last packet can be partial gso_size, account for that in checksum */
258 newlen = htons(skb_tail_pointer(seg) - skb_transport_header(seg) +
259 seg->data_len);
260 check = csum16_add(csum16_sub(uh->check, uh->len), newlen);
261
262 uh->len = newlen;
263 uh->check = check;
264
265 if (seg->ip_summed == CHECKSUM_PARTIAL)
266 gso_reset_checksum(seg, ~check);
267 else
268 uh->check = gso_make_checksum(seg, ~check) ? : CSUM_MANGLED_0;
269
270 /* update refcount for the packet */
271 if (copy_dtor) {
272 int delta = sum_truesize - gso_skb->truesize;
273
274 /* In some pathological cases, delta can be negative.
275 * We need to either use refcount_add() or refcount_sub_and_test()
276 */
277 if (likely(delta >= 0))
278 refcount_add(delta, &sk->sk_wmem_alloc);
279 else
280 WARN_ON_ONCE(refcount_sub_and_test(-delta, &sk->sk_wmem_alloc));
281 }
282 return segs;
283 }
284 EXPORT_SYMBOL_GPL(__udp_gso_segment);
285
286 static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb,
287 netdev_features_t features)
288 {
289 struct sk_buff *segs = ERR_PTR(-EINVAL);
290 unsigned int mss;
291 __wsum csum;
292 struct udphdr *uh;
293 struct iphdr *iph;
294
295 if (skb->encapsulation &&
296 (skb_shinfo(skb)->gso_type &
297 (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM))) {
298 segs = skb_udp_tunnel_segment(skb, features, false);
299 goto out;
300 }
301
302 if (!(skb_shinfo(skb)->gso_type & (SKB_GSO_UDP | SKB_GSO_UDP_L4)))
303 goto out;
304
305 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
306 goto out;
307
308 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4)
309 return __udp_gso_segment(skb, features);
310
311 mss = skb_shinfo(skb)->gso_size;
312 if (unlikely(skb->len <= mss))
313 goto out;
314
315 /* Do software UFO. Complete and fill in the UDP checksum as
316 * HW cannot do checksum of UDP packets sent as multiple
317 * IP fragments.
318 */
319
320 uh = udp_hdr(skb);
321 iph = ip_hdr(skb);
322
323 uh->check = 0;
324 csum = skb_checksum(skb, 0, skb->len, 0);
325 uh->check = udp_v4_check(skb->len, iph->saddr, iph->daddr, csum);
326 if (uh->check == 0)
327 uh->check = CSUM_MANGLED_0;
328
329 skb->ip_summed = CHECKSUM_UNNECESSARY;
330
331 /* If there is no outer header we can fake a checksum offload
332 * due to the fact that we have already done the checksum in
333 * software prior to segmenting the frame.
334 */
335 if (!skb->encap_hdr_csum)
336 features |= NETIF_F_HW_CSUM;
337
338 /* Fragment the skb. IP headers of the fragments are updated in
339 * inet_gso_segment()
340 */
341 segs = skb_segment(skb, features);
342 out:
343 return segs;
344 }
345
346 struct sk_buff *udp_gro_receive(struct list_head *head, struct sk_buff *skb,
347 struct udphdr *uh, udp_lookup_t lookup)
348 {
349 struct sk_buff *pp = NULL;
350 struct sk_buff *p;
351 struct udphdr *uh2;
352 unsigned int off = skb_gro_offset(skb);
353 int flush = 1;
354 struct sock *sk;
355
356 if (NAPI_GRO_CB(skb)->encap_mark ||
357 (skb->ip_summed != CHECKSUM_PARTIAL &&
358 NAPI_GRO_CB(skb)->csum_cnt == 0 &&
359 !NAPI_GRO_CB(skb)->csum_valid))
360 goto out;
361
362 /* mark that this skb passed once through the tunnel gro layer */
363 NAPI_GRO_CB(skb)->encap_mark = 1;
364
365 rcu_read_lock();
366 sk = (*lookup)(skb, uh->source, uh->dest);
367
368 if (sk && udp_sk(sk)->gro_receive)
369 goto unflush;
370 goto out_unlock;
371
372 unflush:
373 flush = 0;
374
375 list_for_each_entry(p, head, list) {
376 if (!NAPI_GRO_CB(p)->same_flow)
377 continue;
378
379 uh2 = (struct udphdr *)(p->data + off);
380
381 /* Match ports and either checksums are either both zero
382 * or nonzero.
383 */
384 if ((*(u32 *)&uh->source != *(u32 *)&uh2->source) ||
385 (!uh->check ^ !uh2->check)) {
386 NAPI_GRO_CB(p)->same_flow = 0;
387 continue;
388 }
389 }
390
391 skb_gro_pull(skb, sizeof(struct udphdr)); /* pull encapsulating udp header */
392 skb_gro_postpull_rcsum(skb, uh, sizeof(struct udphdr));
393 pp = call_gro_receive_sk(udp_sk(sk)->gro_receive, sk, head, skb);
394
395 out_unlock:
396 rcu_read_unlock();
397 out:
398 skb_gro_flush_final(skb, pp, flush);
399 return pp;
400 }
401 EXPORT_SYMBOL(udp_gro_receive);
402
403 static struct sk_buff *udp4_gro_receive(struct list_head *head,
404 struct sk_buff *skb)
405 {
406 struct udphdr *uh = udp_gro_udphdr(skb);
407
408 if (unlikely(!uh))
409 goto flush;
410
411 /* Don't bother verifying checksum if we're going to flush anyway. */
412 if (NAPI_GRO_CB(skb)->flush)
413 goto skip;
414
415 if (skb_gro_checksum_validate_zero_check(skb, IPPROTO_UDP, uh->check,
416 inet_gro_compute_pseudo))
417 goto flush;
418 else if (uh->check)
419 skb_gro_checksum_try_convert(skb, IPPROTO_UDP, uh->check,
420 inet_gro_compute_pseudo);
421 skip:
422 NAPI_GRO_CB(skb)->is_ipv6 = 0;
423 return udp_gro_receive(head, skb, uh, udp4_lib_lookup_skb);
424
425 flush:
426 NAPI_GRO_CB(skb)->flush = 1;
427 return NULL;
428 }
429
430 int udp_gro_complete(struct sk_buff *skb, int nhoff,
431 udp_lookup_t lookup)
432 {
433 __be16 newlen = htons(skb->len - nhoff);
434 struct udphdr *uh = (struct udphdr *)(skb->data + nhoff);
435 int err = -ENOSYS;
436 struct sock *sk;
437
438 uh->len = newlen;
439
440 /* Set encapsulation before calling into inner gro_complete() functions
441 * to make them set up the inner offsets.
442 */
443 skb->encapsulation = 1;
444
445 rcu_read_lock();
446 sk = (*lookup)(skb, uh->source, uh->dest);
447 if (sk && udp_sk(sk)->gro_complete)
448 err = udp_sk(sk)->gro_complete(sk, skb,
449 nhoff + sizeof(struct udphdr));
450 rcu_read_unlock();
451
452 if (skb->remcsum_offload)
453 skb_shinfo(skb)->gso_type |= SKB_GSO_TUNNEL_REMCSUM;
454
455 return err;
456 }
457 EXPORT_SYMBOL(udp_gro_complete);
458
459 static int udp4_gro_complete(struct sk_buff *skb, int nhoff)
460 {
461 const struct iphdr *iph = ip_hdr(skb);
462 struct udphdr *uh = (struct udphdr *)(skb->data + nhoff);
463
464 if (uh->check) {
465 skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL_CSUM;
466 uh->check = ~udp_v4_check(skb->len - nhoff, iph->saddr,
467 iph->daddr, 0);
468 } else {
469 skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL;
470 }
471
472 return udp_gro_complete(skb, nhoff, udp4_lib_lookup_skb);
473 }
474
475 static const struct net_offload udpv4_offload = {
476 .callbacks = {
477 .gso_segment = udp4_ufo_fragment,
478 .gro_receive = udp4_gro_receive,
479 .gro_complete = udp4_gro_complete,
480 },
481 };
482
483 int __init udpv4_offload_init(void)
484 {
485 return inet_add_offload(&udpv4_offload, IPPROTO_UDP);
486 }
Linux with added FPC-III support