1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * IPV6 GSO/GRO offload support
4 * Linux INET6 implementation
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>
13 #include <net/protocol.h>
15 #include <net/inet_common.h>
21 #include "ip6_offload.h"
23 /* All GRO functions are always builtin, except UDP over ipv6, which lays in
24 * ipv6 module, as it depends on UDPv6 lookup function, so we need special care
25 * when ipv6 is built as a module
27 #if IS_BUILTIN(CONFIG_IPV6)
28 #define INDIRECT_CALL_L4(f, f2, f1, ...) INDIRECT_CALL_2(f, f2, f1, __VA_ARGS__)
30 #define INDIRECT_CALL_L4(f, f2, f1, ...) INDIRECT_CALL_1(f, f2, __VA_ARGS__)
33 #define indirect_call_gro_receive_l4(f2, f1, cb, head, skb) \
35 unlikely(gro_recursion_inc_test(skb)) ? \
36 NAPI_GRO_CB(skb)->flush |= 1, NULL : \
37 INDIRECT_CALL_L4(cb, f2, f1, head, skb); \
40 static int ipv6_gro_pull_exthdrs(struct sk_buff *skb, int off, int proto)
42 const struct net_offload *ops = NULL;
43 struct ipv6_opt_hdr *opth;
48 ops = rcu_dereference(inet6_offloads[proto]);
53 if (!(ops->flags & INET6_PROTO_GSO_EXTHDR))
56 opth = skb_gro_header(skb, off + sizeof(*opth), off);
60 len = ipv6_optlen(opth);
62 opth = skb_gro_header(skb, off + len, off);
65 proto = opth->nexthdr;
70 skb_gro_pull(skb, off - skb_network_offset(skb));
74 static int ipv6_gso_pull_exthdrs(struct sk_buff *skb, int proto)
76 const struct net_offload *ops = NULL;
79 struct ipv6_opt_hdr *opth;
82 ops = rcu_dereference(inet6_offloads[proto]);
87 if (!(ops->flags & INET6_PROTO_GSO_EXTHDR))
90 if (unlikely(!pskb_may_pull(skb, 8)))
93 opth = (void *)skb->data;
94 len = ipv6_optlen(opth);
96 if (unlikely(!pskb_may_pull(skb, len)))
99 opth = (void *)skb->data;
100 proto = opth->nexthdr;
101 __skb_pull(skb, len);
107 static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,
108 netdev_features_t features)
110 struct sk_buff *segs = ERR_PTR(-EINVAL);
111 struct ipv6hdr *ipv6h;
112 const struct net_offload *ops;
114 struct frag_hdr *fptr;
115 unsigned int payload_len;
122 skb_reset_network_header(skb);
123 err = ipv6_hopopt_jumbo_remove(skb);
126 nhoff = skb_network_header(skb) - skb_mac_header(skb);
127 if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h))))
130 encap = SKB_GSO_CB(skb)->encap_level > 0;
132 features &= skb->dev->hw_enc_features;
133 SKB_GSO_CB(skb)->encap_level += sizeof(*ipv6h);
135 ipv6h = ipv6_hdr(skb);
136 __skb_pull(skb, sizeof(*ipv6h));
137 segs = ERR_PTR(-EPROTONOSUPPORT);
139 proto = ipv6_gso_pull_exthdrs(skb, ipv6h->nexthdr);
141 if (skb->encapsulation &&
142 skb_shinfo(skb)->gso_type & (SKB_GSO_IPXIP4 | SKB_GSO_IPXIP6))
143 udpfrag = proto == IPPROTO_UDP && encap &&
144 (skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
146 udpfrag = proto == IPPROTO_UDP && !skb->encapsulation &&
147 (skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
149 ops = rcu_dereference(inet6_offloads[proto]);
150 if (likely(ops && ops->callbacks.gso_segment)) {
151 skb_reset_transport_header(skb);
152 segs = ops->callbacks.gso_segment(skb, features);
154 skb->network_header = skb_mac_header(skb) + nhoff - skb->head;
157 if (IS_ERR_OR_NULL(segs))
160 gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);
162 for (skb = segs; skb; skb = skb->next) {
163 ipv6h = (struct ipv6hdr *)(skb_mac_header(skb) + nhoff);
164 if (gso_partial && skb_is_gso(skb))
165 payload_len = skb_shinfo(skb)->gso_size +
166 SKB_GSO_CB(skb)->data_offset +
167 skb->head - (unsigned char *)(ipv6h + 1);
169 payload_len = skb->len - nhoff - sizeof(*ipv6h);
170 ipv6h->payload_len = htons(payload_len);
171 skb->network_header = (u8 *)ipv6h - skb->head;
172 skb_reset_mac_len(skb);
175 int err = ip6_find_1stfragopt(skb, &prevhdr);
177 kfree_skb_list(segs);
180 fptr = (struct frag_hdr *)((u8 *)ipv6h + err);
181 fptr->frag_off = htons(offset);
183 fptr->frag_off |= htons(IP6_MF);
184 offset += (ntohs(ipv6h->payload_len) -
185 sizeof(struct frag_hdr));
188 skb_reset_inner_headers(skb);
195 /* Return the total length of all the extension hdrs, following the same
196 * logic in ipv6_gso_pull_exthdrs() when parsing ext-hdrs.
198 static int ipv6_exthdrs_len(struct ipv6hdr *iph,
199 const struct net_offload **opps)
201 struct ipv6_opt_hdr *opth = (void *)iph;
202 int len = 0, proto, optlen = sizeof(*iph);
204 proto = iph->nexthdr;
206 *opps = rcu_dereference(inet6_offloads[proto]);
207 if (unlikely(!(*opps)))
209 if (!((*opps)->flags & INET6_PROTO_GSO_EXTHDR))
212 opth = (void *)opth + optlen;
213 optlen = ipv6_optlen(opth);
215 proto = opth->nexthdr;
220 INDIRECT_CALLABLE_SCOPE struct sk_buff *ipv6_gro_receive(struct list_head *head,
223 const struct net_offload *ops;
224 struct sk_buff *pp = NULL;
233 off = skb_gro_offset(skb);
234 hlen = off + sizeof(*iph);
235 iph = skb_gro_header(skb, hlen, off);
239 skb_set_network_header(skb, off);
241 flush += ntohs(iph->payload_len) != skb->len - hlen;
243 proto = iph->nexthdr;
244 ops = rcu_dereference(inet6_offloads[proto]);
245 if (!ops || !ops->callbacks.gro_receive) {
246 proto = ipv6_gro_pull_exthdrs(skb, hlen, proto);
248 ops = rcu_dereference(inet6_offloads[proto]);
249 if (!ops || !ops->callbacks.gro_receive)
252 iph = skb_gro_network_header(skb);
254 skb_gro_pull(skb, sizeof(*iph));
257 skb_set_transport_header(skb, skb_gro_offset(skb));
259 NAPI_GRO_CB(skb)->proto = proto;
262 nlen = skb_network_header_len(skb);
264 list_for_each_entry(p, head, list) {
265 const struct ipv6hdr *iph2;
266 __be32 first_word; /* <Version:4><Traffic_Class:8><Flow_Label:20> */
268 if (!NAPI_GRO_CB(p)->same_flow)
271 iph2 = (struct ipv6hdr *)(p->data + off);
272 first_word = *(__be32 *)iph ^ *(__be32 *)iph2;
274 /* All fields must match except length and Traffic Class.
275 * XXX skbs on the gro_list have all been parsed and pulled
276 * already so we don't need to compare nlen
277 * (nlen != (sizeof(*iph2) + ipv6_exthdrs_len(iph2, &ops)))
278 * memcmp() alone below is sufficient, right?
280 if ((first_word & htonl(0xF00FFFFF)) ||
281 !ipv6_addr_equal(&iph->saddr, &iph2->saddr) ||
282 !ipv6_addr_equal(&iph->daddr, &iph2->daddr) ||
283 iph->nexthdr != iph2->nexthdr) {
285 NAPI_GRO_CB(p)->same_flow = 0;
288 if (unlikely(nlen > sizeof(struct ipv6hdr))) {
289 if (memcmp(iph + 1, iph2 + 1,
290 nlen - sizeof(struct ipv6hdr)))
293 /* flush if Traffic Class fields are different */
294 NAPI_GRO_CB(p)->flush |= !!((first_word & htonl(0x0FF00000)) |
295 (__force __be32)(iph->hop_limit ^ iph2->hop_limit));
296 NAPI_GRO_CB(p)->flush |= flush;
298 /* If the previous IP ID value was based on an atomic
299 * datagram we can overwrite the value and ignore it.
301 if (NAPI_GRO_CB(skb)->is_atomic)
302 NAPI_GRO_CB(p)->flush_id = 0;
305 NAPI_GRO_CB(skb)->is_atomic = true;
306 NAPI_GRO_CB(skb)->flush |= flush;
308 skb_gro_postpull_rcsum(skb, iph, nlen);
310 pp = indirect_call_gro_receive_l4(tcp6_gro_receive, udp6_gro_receive,
311 ops->callbacks.gro_receive, head, skb);
314 skb_gro_flush_final(skb, pp, flush);
319 static struct sk_buff *sit_ip6ip6_gro_receive(struct list_head *head,
322 /* Common GRO receive for SIT and IP6IP6 */
324 if (NAPI_GRO_CB(skb)->encap_mark) {
325 NAPI_GRO_CB(skb)->flush = 1;
329 NAPI_GRO_CB(skb)->encap_mark = 1;
331 return ipv6_gro_receive(head, skb);
334 static struct sk_buff *ip4ip6_gro_receive(struct list_head *head,
337 /* Common GRO receive for SIT and IP6IP6 */
339 if (NAPI_GRO_CB(skb)->encap_mark) {
340 NAPI_GRO_CB(skb)->flush = 1;
344 NAPI_GRO_CB(skb)->encap_mark = 1;
346 return inet_gro_receive(head, skb);
349 INDIRECT_CALLABLE_SCOPE int ipv6_gro_complete(struct sk_buff *skb, int nhoff)
351 const struct net_offload *ops;
356 if (skb->encapsulation) {
357 skb_set_inner_protocol(skb, cpu_to_be16(ETH_P_IPV6));
358 skb_set_inner_network_header(skb, nhoff);
361 payload_len = skb->len - nhoff - sizeof(*iph);
362 if (unlikely(payload_len > IPV6_MAXPLEN)) {
363 struct hop_jumbo_hdr *hop_jumbo;
364 int hoplen = sizeof(*hop_jumbo);
366 /* Move network header left */
367 memmove(skb_mac_header(skb) - hoplen, skb_mac_header(skb),
368 skb->transport_header - skb->mac_header);
371 skb->mac_header -= hoplen;
372 skb->network_header -= hoplen;
373 iph = (struct ipv6hdr *)(skb->data + nhoff);
374 hop_jumbo = (struct hop_jumbo_hdr *)(iph + 1);
376 /* Build hop-by-hop options */
377 hop_jumbo->nexthdr = iph->nexthdr;
378 hop_jumbo->hdrlen = 0;
379 hop_jumbo->tlv_type = IPV6_TLV_JUMBO;
380 hop_jumbo->tlv_len = 4;
381 hop_jumbo->jumbo_payload_len = htonl(payload_len + hoplen);
383 iph->nexthdr = NEXTHDR_HOP;
384 iph->payload_len = 0;
386 iph = (struct ipv6hdr *)(skb->data + nhoff);
387 iph->payload_len = htons(payload_len);
390 nhoff += sizeof(*iph) + ipv6_exthdrs_len(iph, &ops);
391 if (WARN_ON(!ops || !ops->callbacks.gro_complete))
394 err = INDIRECT_CALL_L4(ops->callbacks.gro_complete, tcp6_gro_complete,
395 udp6_gro_complete, skb, nhoff);
401 static int sit_gro_complete(struct sk_buff *skb, int nhoff)
403 skb->encapsulation = 1;
404 skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4;
405 return ipv6_gro_complete(skb, nhoff);
408 static int ip6ip6_gro_complete(struct sk_buff *skb, int nhoff)
410 skb->encapsulation = 1;
411 skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP6;
412 return ipv6_gro_complete(skb, nhoff);
415 static int ip4ip6_gro_complete(struct sk_buff *skb, int nhoff)
417 skb->encapsulation = 1;
418 skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP6;
419 return inet_gro_complete(skb, nhoff);
422 static struct packet_offload ipv6_packet_offload __read_mostly = {
423 .type = cpu_to_be16(ETH_P_IPV6),
425 .gso_segment = ipv6_gso_segment,
426 .gro_receive = ipv6_gro_receive,
427 .gro_complete = ipv6_gro_complete,
431 static struct sk_buff *sit_gso_segment(struct sk_buff *skb,
432 netdev_features_t features)
434 if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP4))
435 return ERR_PTR(-EINVAL);
437 return ipv6_gso_segment(skb, features);
440 static struct sk_buff *ip4ip6_gso_segment(struct sk_buff *skb,
441 netdev_features_t features)
443 if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP6))
444 return ERR_PTR(-EINVAL);
446 return inet_gso_segment(skb, features);
449 static struct sk_buff *ip6ip6_gso_segment(struct sk_buff *skb,
450 netdev_features_t features)
452 if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP6))
453 return ERR_PTR(-EINVAL);
455 return ipv6_gso_segment(skb, features);
458 static const struct net_offload sit_offload = {
460 .gso_segment = sit_gso_segment,
461 .gro_receive = sit_ip6ip6_gro_receive,
462 .gro_complete = sit_gro_complete,
466 static const struct net_offload ip4ip6_offload = {
468 .gso_segment = ip4ip6_gso_segment,
469 .gro_receive = ip4ip6_gro_receive,
470 .gro_complete = ip4ip6_gro_complete,
474 static const struct net_offload ip6ip6_offload = {
476 .gso_segment = ip6ip6_gso_segment,
477 .gro_receive = sit_ip6ip6_gro_receive,
478 .gro_complete = ip6ip6_gro_complete,
481 static int __init ipv6_offload_init(void)
484 if (tcpv6_offload_init() < 0)
485 pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
486 if (ipv6_exthdrs_offload_init() < 0)
487 pr_crit("%s: Cannot add EXTHDRS protocol offload\n", __func__);
489 dev_add_offload(&ipv6_packet_offload);
491 inet_add_offload(&sit_offload, IPPROTO_IPV6);
492 inet6_add_offload(&ip6ip6_offload, IPPROTO_IPV6);
493 inet6_add_offload(&ip4ip6_offload, IPPROTO_IPIP);
498 fs_initcall(ipv6_offload_init);