Line data Source code
1 : // SPDX-License-Identifier: GPL-2.0-or-later
2 : /*
3 : * IPV6 GSO/GRO offload support
4 : * Linux INET6 implementation
5 : */
6 :
7 : #include <linux/kernel.h>
8 : #include <linux/socket.h>
9 : #include <linux/netdevice.h>
10 : #include <linux/skbuff.h>
11 : #include <linux/printk.h>
12 :
13 : #include <net/protocol.h>
14 : #include <net/ipv6.h>
15 : #include <net/inet_common.h>
16 : #include <net/tcp.h>
17 : #include <net/udp.h>
18 : #include <net/gro.h>
19 :
20 : #include "ip6_offload.h"
21 :
22 : /* All GRO functions are always builtin, except UDP over ipv6, which lays in
23 : * ipv6 module, as it depends on UDPv6 lookup function, so we need special care
24 : * when ipv6 is built as a module
25 : */
26 : #if IS_BUILTIN(CONFIG_IPV6)
27 : #define INDIRECT_CALL_L4(f, f2, f1, ...) INDIRECT_CALL_2(f, f2, f1, __VA_ARGS__)
28 : #else
29 : #define INDIRECT_CALL_L4(f, f2, f1, ...) INDIRECT_CALL_1(f, f2, __VA_ARGS__)
30 : #endif
31 :
32 : #define indirect_call_gro_receive_l4(f2, f1, cb, head, skb) \
33 : ({ \
34 : unlikely(gro_recursion_inc_test(skb)) ? \
35 : NAPI_GRO_CB(skb)->flush |= 1, NULL : \
36 : INDIRECT_CALL_L4(cb, f2, f1, head, skb); \
37 : })
38 :
39 0 : static int ipv6_gso_pull_exthdrs(struct sk_buff *skb, int proto)
40 : {
41 0 : const struct net_offload *ops = NULL;
42 :
43 0 : for (;;) {
44 0 : struct ipv6_opt_hdr *opth;
45 0 : int len;
46 :
47 0 : if (proto != NEXTHDR_HOP) {
48 0 : ops = rcu_dereference(inet6_offloads[proto]);
49 :
50 0 : if (unlikely(!ops))
51 : break;
52 :
53 0 : if (!(ops->flags & INET6_PROTO_GSO_EXTHDR))
54 : break;
55 : }
56 :
57 0 : if (unlikely(!pskb_may_pull(skb, 8)))
58 : break;
59 :
60 0 : opth = (void *)skb->data;
61 0 : len = ipv6_optlen(opth);
62 :
63 0 : if (unlikely(!pskb_may_pull(skb, len)))
64 : break;
65 :
66 0 : opth = (void *)skb->data;
67 0 : proto = opth->nexthdr;
68 0 : __skb_pull(skb, len);
69 : }
70 :
71 0 : return proto;
72 : }
73 :
74 0 : static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,
75 : netdev_features_t features)
76 : {
77 0 : struct sk_buff *segs = ERR_PTR(-EINVAL);
78 0 : struct ipv6hdr *ipv6h;
79 0 : const struct net_offload *ops;
80 0 : int proto;
81 0 : struct frag_hdr *fptr;
82 0 : unsigned int payload_len;
83 0 : u8 *prevhdr;
84 0 : int offset = 0;
85 0 : bool encap, udpfrag;
86 0 : int nhoff;
87 0 : bool gso_partial;
88 :
89 0 : skb_reset_network_header(skb);
90 0 : nhoff = skb_network_header(skb) - skb_mac_header(skb);
91 0 : if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h))))
92 0 : goto out;
93 :
94 0 : encap = SKB_GSO_CB(skb)->encap_level > 0;
95 0 : if (encap)
96 0 : features &= skb->dev->hw_enc_features;
97 0 : SKB_GSO_CB(skb)->encap_level += sizeof(*ipv6h);
98 :
99 0 : ipv6h = ipv6_hdr(skb);
100 0 : __skb_pull(skb, sizeof(*ipv6h));
101 0 : segs = ERR_PTR(-EPROTONOSUPPORT);
102 :
103 0 : proto = ipv6_gso_pull_exthdrs(skb, ipv6h->nexthdr);
104 :
105 0 : if (skb->encapsulation &&
106 0 : skb_shinfo(skb)->gso_type & (SKB_GSO_IPXIP4 | SKB_GSO_IPXIP6))
107 0 : udpfrag = proto == IPPROTO_UDP && encap &&
108 0 : (skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
109 : else
110 0 : udpfrag = proto == IPPROTO_UDP && !skb->encapsulation &&
111 0 : (skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
112 :
113 0 : ops = rcu_dereference(inet6_offloads[proto]);
114 0 : if (likely(ops && ops->callbacks.gso_segment)) {
115 0 : skb_reset_transport_header(skb);
116 0 : segs = ops->callbacks.gso_segment(skb, features);
117 : }
118 :
119 0 : if (IS_ERR_OR_NULL(segs))
120 0 : goto out;
121 :
122 0 : gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);
123 :
124 0 : for (skb = segs; skb; skb = skb->next) {
125 0 : ipv6h = (struct ipv6hdr *)(skb_mac_header(skb) + nhoff);
126 0 : if (gso_partial && skb_is_gso(skb))
127 0 : payload_len = skb_shinfo(skb)->gso_size +
128 0 : SKB_GSO_CB(skb)->data_offset +
129 0 : skb->head - (unsigned char *)(ipv6h + 1);
130 : else
131 0 : payload_len = skb->len - nhoff - sizeof(*ipv6h);
132 0 : ipv6h->payload_len = htons(payload_len);
133 0 : skb->network_header = (u8 *)ipv6h - skb->head;
134 0 : skb_reset_mac_len(skb);
135 :
136 0 : if (udpfrag) {
137 0 : int err = ip6_find_1stfragopt(skb, &prevhdr);
138 0 : if (err < 0) {
139 0 : kfree_skb_list(segs);
140 0 : return ERR_PTR(err);
141 : }
142 0 : fptr = (struct frag_hdr *)((u8 *)ipv6h + err);
143 0 : fptr->frag_off = htons(offset);
144 0 : if (skb->next)
145 0 : fptr->frag_off |= htons(IP6_MF);
146 0 : offset += (ntohs(ipv6h->payload_len) -
147 : sizeof(struct frag_hdr));
148 : }
149 0 : if (encap)
150 0 : skb_reset_inner_headers(skb);
151 : }
152 :
153 0 : out:
154 : return segs;
155 : }
156 :
157 : /* Return the total length of all the extension hdrs, following the same
158 : * logic in ipv6_gso_pull_exthdrs() when parsing ext-hdrs.
159 : */
160 0 : static int ipv6_exthdrs_len(struct ipv6hdr *iph,
161 : const struct net_offload **opps)
162 : {
163 0 : struct ipv6_opt_hdr *opth = (void *)iph;
164 0 : int len = 0, proto, optlen = sizeof(*iph);
165 :
166 0 : proto = iph->nexthdr;
167 0 : for (;;) {
168 0 : if (proto != NEXTHDR_HOP) {
169 0 : *opps = rcu_dereference(inet6_offloads[proto]);
170 0 : if (unlikely(!(*opps)))
171 : break;
172 0 : if (!((*opps)->flags & INET6_PROTO_GSO_EXTHDR))
173 : break;
174 : }
175 0 : opth = (void *)opth + optlen;
176 0 : optlen = ipv6_optlen(opth);
177 0 : len += optlen;
178 0 : proto = opth->nexthdr;
179 : }
180 0 : return len;
181 : }
182 :
183 0 : INDIRECT_CALLABLE_SCOPE struct sk_buff *ipv6_gro_receive(struct list_head *head,
184 : struct sk_buff *skb)
185 : {
186 0 : const struct net_offload *ops;
187 0 : struct sk_buff *pp = NULL;
188 0 : struct sk_buff *p;
189 0 : struct ipv6hdr *iph;
190 0 : unsigned int nlen;
191 0 : unsigned int hlen;
192 0 : unsigned int off;
193 0 : u16 flush = 1;
194 0 : int proto;
195 :
196 0 : off = skb_gro_offset(skb);
197 0 : hlen = off + sizeof(*iph);
198 0 : iph = skb_gro_header_fast(skb, off);
199 0 : if (skb_gro_header_hard(skb, hlen)) {
200 0 : iph = skb_gro_header_slow(skb, hlen, off);
201 0 : if (unlikely(!iph))
202 0 : goto out;
203 : }
204 :
205 0 : skb_set_network_header(skb, off);
206 0 : skb_gro_pull(skb, sizeof(*iph));
207 0 : skb_set_transport_header(skb, skb_gro_offset(skb));
208 :
209 0 : flush += ntohs(iph->payload_len) != skb_gro_len(skb);
210 :
211 0 : rcu_read_lock();
212 0 : proto = iph->nexthdr;
213 0 : ops = rcu_dereference(inet6_offloads[proto]);
214 0 : if (!ops || !ops->callbacks.gro_receive) {
215 0 : __pskb_pull(skb, skb_gro_offset(skb));
216 0 : skb_gro_frag0_invalidate(skb);
217 0 : proto = ipv6_gso_pull_exthdrs(skb, proto);
218 0 : skb_gro_pull(skb, -skb_transport_offset(skb));
219 0 : skb_reset_transport_header(skb);
220 0 : __skb_push(skb, skb_gro_offset(skb));
221 :
222 0 : ops = rcu_dereference(inet6_offloads[proto]);
223 0 : if (!ops || !ops->callbacks.gro_receive)
224 0 : goto out_unlock;
225 :
226 0 : iph = ipv6_hdr(skb);
227 : }
228 :
229 0 : NAPI_GRO_CB(skb)->proto = proto;
230 :
231 0 : flush--;
232 0 : nlen = skb_network_header_len(skb);
233 :
234 0 : list_for_each_entry(p, head, list) {
235 0 : const struct ipv6hdr *iph2;
236 0 : __be32 first_word; /* <Version:4><Traffic_Class:8><Flow_Label:20> */
237 :
238 0 : if (!NAPI_GRO_CB(p)->same_flow)
239 0 : continue;
240 :
241 0 : iph2 = (struct ipv6hdr *)(p->data + off);
242 0 : first_word = *(__be32 *)iph ^ *(__be32 *)iph2;
243 :
244 : /* All fields must match except length and Traffic Class.
245 : * XXX skbs on the gro_list have all been parsed and pulled
246 : * already so we don't need to compare nlen
247 : * (nlen != (sizeof(*iph2) + ipv6_exthdrs_len(iph2, &ops)))
248 : * memcmp() alone below is sufficient, right?
249 : */
250 0 : if ((first_word & htonl(0xF00FFFFF)) ||
251 0 : !ipv6_addr_equal(&iph->saddr, &iph2->saddr) ||
252 0 : !ipv6_addr_equal(&iph->daddr, &iph2->daddr) ||
253 0 : *(u16 *)&iph->nexthdr != *(u16 *)&iph2->nexthdr) {
254 0 : not_same_flow:
255 0 : NAPI_GRO_CB(p)->same_flow = 0;
256 0 : continue;
257 : }
258 0 : if (unlikely(nlen > sizeof(struct ipv6hdr))) {
259 0 : if (memcmp(iph + 1, iph2 + 1,
260 : nlen - sizeof(struct ipv6hdr)))
261 0 : goto not_same_flow;
262 : }
263 : /* flush if Traffic Class fields are different */
264 0 : NAPI_GRO_CB(p)->flush |= !!(first_word & htonl(0x0FF00000));
265 0 : NAPI_GRO_CB(p)->flush |= flush;
266 :
267 : /* If the previous IP ID value was based on an atomic
268 : * datagram we can overwrite the value and ignore it.
269 : */
270 0 : if (NAPI_GRO_CB(skb)->is_atomic)
271 0 : NAPI_GRO_CB(p)->flush_id = 0;
272 : }
273 :
274 0 : NAPI_GRO_CB(skb)->is_atomic = true;
275 0 : NAPI_GRO_CB(skb)->flush |= flush;
276 :
277 0 : skb_gro_postpull_rcsum(skb, iph, nlen);
278 :
279 0 : pp = indirect_call_gro_receive_l4(tcp6_gro_receive, udp6_gro_receive,
280 : ops->callbacks.gro_receive, head, skb);
281 :
282 0 : out_unlock:
283 0 : rcu_read_unlock();
284 :
285 0 : out:
286 0 : skb_gro_flush_final(skb, pp, flush);
287 :
288 0 : return pp;
289 : }
290 :
291 0 : static struct sk_buff *sit_ip6ip6_gro_receive(struct list_head *head,
292 : struct sk_buff *skb)
293 : {
294 : /* Common GRO receive for SIT and IP6IP6 */
295 :
296 0 : if (NAPI_GRO_CB(skb)->encap_mark) {
297 0 : NAPI_GRO_CB(skb)->flush = 1;
298 0 : return NULL;
299 : }
300 :
301 0 : NAPI_GRO_CB(skb)->encap_mark = 1;
302 :
303 0 : return ipv6_gro_receive(head, skb);
304 : }
305 :
306 0 : static struct sk_buff *ip4ip6_gro_receive(struct list_head *head,
307 : struct sk_buff *skb)
308 : {
309 : /* Common GRO receive for SIT and IP6IP6 */
310 :
311 0 : if (NAPI_GRO_CB(skb)->encap_mark) {
312 0 : NAPI_GRO_CB(skb)->flush = 1;
313 0 : return NULL;
314 : }
315 :
316 0 : NAPI_GRO_CB(skb)->encap_mark = 1;
317 :
318 0 : return inet_gro_receive(head, skb);
319 : }
320 :
321 0 : INDIRECT_CALLABLE_SCOPE int ipv6_gro_complete(struct sk_buff *skb, int nhoff)
322 : {
323 0 : const struct net_offload *ops;
324 0 : struct ipv6hdr *iph = (struct ipv6hdr *)(skb->data + nhoff);
325 0 : int err = -ENOSYS;
326 :
327 0 : if (skb->encapsulation) {
328 0 : skb_set_inner_protocol(skb, cpu_to_be16(ETH_P_IPV6));
329 0 : skb_set_inner_network_header(skb, nhoff);
330 : }
331 :
332 0 : iph->payload_len = htons(skb->len - nhoff - sizeof(*iph));
333 :
334 0 : rcu_read_lock();
335 :
336 0 : nhoff += sizeof(*iph) + ipv6_exthdrs_len(iph, &ops);
337 0 : if (WARN_ON(!ops || !ops->callbacks.gro_complete))
338 0 : goto out_unlock;
339 :
340 0 : err = INDIRECT_CALL_L4(ops->callbacks.gro_complete, tcp6_gro_complete,
341 : udp6_gro_complete, skb, nhoff);
342 :
343 0 : out_unlock:
344 0 : rcu_read_unlock();
345 :
346 0 : return err;
347 : }
348 :
349 0 : static int sit_gro_complete(struct sk_buff *skb, int nhoff)
350 : {
351 0 : skb->encapsulation = 1;
352 0 : skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4;
353 0 : return ipv6_gro_complete(skb, nhoff);
354 : }
355 :
356 0 : static int ip6ip6_gro_complete(struct sk_buff *skb, int nhoff)
357 : {
358 0 : skb->encapsulation = 1;
359 0 : skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP6;
360 0 : return ipv6_gro_complete(skb, nhoff);
361 : }
362 :
363 0 : static int ip4ip6_gro_complete(struct sk_buff *skb, int nhoff)
364 : {
365 0 : skb->encapsulation = 1;
366 0 : skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP6;
367 0 : return inet_gro_complete(skb, nhoff);
368 : }
369 :
370 : static struct packet_offload ipv6_packet_offload __read_mostly = {
371 : .type = cpu_to_be16(ETH_P_IPV6),
372 : .callbacks = {
373 : .gso_segment = ipv6_gso_segment,
374 : .gro_receive = ipv6_gro_receive,
375 : .gro_complete = ipv6_gro_complete,
376 : },
377 : };
378 :
379 0 : static struct sk_buff *sit_gso_segment(struct sk_buff *skb,
380 : netdev_features_t features)
381 : {
382 0 : if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP4))
383 0 : return ERR_PTR(-EINVAL);
384 :
385 0 : return ipv6_gso_segment(skb, features);
386 : }
387 :
388 0 : static struct sk_buff *ip4ip6_gso_segment(struct sk_buff *skb,
389 : netdev_features_t features)
390 : {
391 0 : if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP6))
392 0 : return ERR_PTR(-EINVAL);
393 :
394 0 : return inet_gso_segment(skb, features);
395 : }
396 :
397 0 : static struct sk_buff *ip6ip6_gso_segment(struct sk_buff *skb,
398 : netdev_features_t features)
399 : {
400 0 : if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP6))
401 0 : return ERR_PTR(-EINVAL);
402 :
403 0 : return ipv6_gso_segment(skb, features);
404 : }
405 :
406 : static const struct net_offload sit_offload = {
407 : .callbacks = {
408 : .gso_segment = sit_gso_segment,
409 : .gro_receive = sit_ip6ip6_gro_receive,
410 : .gro_complete = sit_gro_complete,
411 : },
412 : };
413 :
414 : static const struct net_offload ip4ip6_offload = {
415 : .callbacks = {
416 : .gso_segment = ip4ip6_gso_segment,
417 : .gro_receive = ip4ip6_gro_receive,
418 : .gro_complete = ip4ip6_gro_complete,
419 : },
420 : };
421 :
422 : static const struct net_offload ip6ip6_offload = {
423 : .callbacks = {
424 : .gso_segment = ip6ip6_gso_segment,
425 : .gro_receive = sit_ip6ip6_gro_receive,
426 : .gro_complete = ip6ip6_gro_complete,
427 : },
428 : };
429 1 : static int __init ipv6_offload_init(void)
430 : {
431 :
432 1 : if (tcpv6_offload_init() < 0)
433 0 : pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
434 1 : if (ipv6_exthdrs_offload_init() < 0)
435 0 : pr_crit("%s: Cannot add EXTHDRS protocol offload\n", __func__);
436 :
437 1 : dev_add_offload(&ipv6_packet_offload);
438 :
439 1 : inet_add_offload(&sit_offload, IPPROTO_IPV6);
440 1 : inet6_add_offload(&ip6ip6_offload, IPPROTO_IPV6);
441 1 : inet6_add_offload(&ip4ip6_offload, IPPROTO_IPIP);
442 :
443 1 : return 0;
444 : }
445 :
446 : fs_initcall(ipv6_offload_init);
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