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>
20 #include "ip6_offload.h"
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
26 #if IS_BUILTIN(CONFIG_IPV6)
27 #define INDIRECT_CALL_L4(f, f2, f1, ...) INDIRECT_CALL_2(f, f2, f1, __VA_ARGS__)
29 #define INDIRECT_CALL_L4(f, f2, f1, ...) INDIRECT_CALL_1(f, f2, __VA_ARGS__)
32 #define indirect_call_gro_receive_l4(f2, f1, cb, head, skb) \
34 unlikely(gro_recursion_inc_test(skb)) ? \
35 NAPI_GRO_CB(skb)->flush |= 1, NULL : \
36 INDIRECT_CALL_L4(cb, f2, f1, head, skb); \
39 static int ipv6_gso_pull_exthdrs(struct sk_buff *skb, int proto)
41 const struct net_offload *ops = NULL;
44 struct ipv6_opt_hdr *opth;
47 if (proto != NEXTHDR_HOP) {
48 ops = rcu_dereference(inet6_offloads[proto]);
53 if (!(ops->flags & INET6_PROTO_GSO_EXTHDR))
57 if (unlikely(!pskb_may_pull(skb, 8)))
60 opth = (void *)skb->data;
61 len = ipv6_optlen(opth);
63 if (unlikely(!pskb_may_pull(skb, len)))
66 opth = (void *)skb->data;
67 proto = opth->nexthdr;
74 static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,
75 netdev_features_t features)
77 struct sk_buff *segs = ERR_PTR(-EINVAL);
78 struct ipv6hdr *ipv6h;
79 const struct net_offload *ops;
81 struct frag_hdr *fptr;
82 unsigned int payload_len;
89 skb_reset_network_header(skb);
90 err = ipv6_hopopt_jumbo_remove(skb);
93 nhoff = skb_network_header(skb) - skb_mac_header(skb);
94 if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h))))
97 encap = SKB_GSO_CB(skb)->encap_level > 0;
99 features &= skb->dev->hw_enc_features;
100 SKB_GSO_CB(skb)->encap_level += sizeof(*ipv6h);
102 ipv6h = ipv6_hdr(skb);
103 __skb_pull(skb, sizeof(*ipv6h));
104 segs = ERR_PTR(-EPROTONOSUPPORT);
106 proto = ipv6_gso_pull_exthdrs(skb, ipv6h->nexthdr);
108 if (skb->encapsulation &&
109 skb_shinfo(skb)->gso_type & (SKB_GSO_IPXIP4 | SKB_GSO_IPXIP6))
110 udpfrag = proto == IPPROTO_UDP && encap &&
111 (skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
113 udpfrag = proto == IPPROTO_UDP && !skb->encapsulation &&
114 (skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
116 ops = rcu_dereference(inet6_offloads[proto]);
117 if (likely(ops && ops->callbacks.gso_segment)) {
118 skb_reset_transport_header(skb);
119 segs = ops->callbacks.gso_segment(skb, features);
121 skb->network_header = skb_mac_header(skb) + nhoff - skb->head;
124 if (IS_ERR_OR_NULL(segs))
127 gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);
129 for (skb = segs; skb; skb = skb->next) {
130 ipv6h = (struct ipv6hdr *)(skb_mac_header(skb) + nhoff);
131 if (gso_partial && skb_is_gso(skb))
132 payload_len = skb_shinfo(skb)->gso_size +
133 SKB_GSO_CB(skb)->data_offset +
134 skb->head - (unsigned char *)(ipv6h + 1);
136 payload_len = skb->len - nhoff - sizeof(*ipv6h);
137 ipv6h->payload_len = htons(payload_len);
138 skb->network_header = (u8 *)ipv6h - skb->head;
139 skb_reset_mac_len(skb);
142 int err = ip6_find_1stfragopt(skb, &prevhdr);
144 kfree_skb_list(segs);
147 fptr = (struct frag_hdr *)((u8 *)ipv6h + err);
148 fptr->frag_off = htons(offset);
150 fptr->frag_off |= htons(IP6_MF);
151 offset += (ntohs(ipv6h->payload_len) -
152 sizeof(struct frag_hdr));
155 skb_reset_inner_headers(skb);
162 /* Return the total length of all the extension hdrs, following the same
163 * logic in ipv6_gso_pull_exthdrs() when parsing ext-hdrs.
165 static int ipv6_exthdrs_len(struct ipv6hdr *iph,
166 const struct net_offload **opps)
168 struct ipv6_opt_hdr *opth = (void *)iph;
169 int len = 0, proto, optlen = sizeof(*iph);
171 proto = iph->nexthdr;
173 if (proto != NEXTHDR_HOP) {
174 *opps = rcu_dereference(inet6_offloads[proto]);
175 if (unlikely(!(*opps)))
177 if (!((*opps)->flags & INET6_PROTO_GSO_EXTHDR))
180 opth = (void *)opth + optlen;
181 optlen = ipv6_optlen(opth);
183 proto = opth->nexthdr;
188 INDIRECT_CALLABLE_SCOPE struct sk_buff *ipv6_gro_receive(struct list_head *head,
191 const struct net_offload *ops;
192 struct sk_buff *pp = NULL;
201 off = skb_gro_offset(skb);
202 hlen = off + sizeof(*iph);
203 iph = skb_gro_header(skb, hlen, off);
207 skb_set_network_header(skb, off);
208 skb_gro_pull(skb, sizeof(*iph));
209 skb_set_transport_header(skb, skb_gro_offset(skb));
211 flush += ntohs(iph->payload_len) != skb_gro_len(skb);
213 proto = iph->nexthdr;
214 ops = rcu_dereference(inet6_offloads[proto]);
215 if (!ops || !ops->callbacks.gro_receive) {
216 pskb_pull(skb, skb_gro_offset(skb));
217 skb_gro_frag0_invalidate(skb);
218 proto = ipv6_gso_pull_exthdrs(skb, proto);
219 skb_gro_pull(skb, -skb_transport_offset(skb));
220 skb_reset_transport_header(skb);
221 __skb_push(skb, skb_gro_offset(skb));
223 ops = rcu_dereference(inet6_offloads[proto]);
224 if (!ops || !ops->callbacks.gro_receive)
230 NAPI_GRO_CB(skb)->proto = proto;
233 nlen = skb_network_header_len(skb);
235 list_for_each_entry(p, head, list) {
236 const struct ipv6hdr *iph2;
237 __be32 first_word; /* <Version:4><Traffic_Class:8><Flow_Label:20> */
239 if (!NAPI_GRO_CB(p)->same_flow)
242 iph2 = (struct ipv6hdr *)(p->data + off);
243 first_word = *(__be32 *)iph ^ *(__be32 *)iph2;
245 /* All fields must match except length and Traffic Class.
246 * XXX skbs on the gro_list have all been parsed and pulled
247 * already so we don't need to compare nlen
248 * (nlen != (sizeof(*iph2) + ipv6_exthdrs_len(iph2, &ops)))
249 * memcmp() alone below is sufficient, right?
251 if ((first_word & htonl(0xF00FFFFF)) ||
252 !ipv6_addr_equal(&iph->saddr, &iph2->saddr) ||
253 !ipv6_addr_equal(&iph->daddr, &iph2->daddr) ||
254 iph->nexthdr != iph2->nexthdr) {
256 NAPI_GRO_CB(p)->same_flow = 0;
259 if (unlikely(nlen > sizeof(struct ipv6hdr))) {
260 if (memcmp(iph + 1, iph2 + 1,
261 nlen - sizeof(struct ipv6hdr)))
264 /* flush if Traffic Class fields are different */
265 NAPI_GRO_CB(p)->flush |= !!((first_word & htonl(0x0FF00000)) |
266 (__force __be32)(iph->hop_limit ^ iph2->hop_limit));
267 NAPI_GRO_CB(p)->flush |= flush;
269 /* If the previous IP ID value was based on an atomic
270 * datagram we can overwrite the value and ignore it.
272 if (NAPI_GRO_CB(skb)->is_atomic)
273 NAPI_GRO_CB(p)->flush_id = 0;
276 NAPI_GRO_CB(skb)->is_atomic = true;
277 NAPI_GRO_CB(skb)->flush |= flush;
279 skb_gro_postpull_rcsum(skb, iph, nlen);
281 pp = indirect_call_gro_receive_l4(tcp6_gro_receive, udp6_gro_receive,
282 ops->callbacks.gro_receive, head, skb);
285 skb_gro_flush_final(skb, pp, flush);
290 static struct sk_buff *sit_ip6ip6_gro_receive(struct list_head *head,
293 /* Common GRO receive for SIT and IP6IP6 */
295 if (NAPI_GRO_CB(skb)->encap_mark) {
296 NAPI_GRO_CB(skb)->flush = 1;
300 NAPI_GRO_CB(skb)->encap_mark = 1;
302 return ipv6_gro_receive(head, skb);
305 static struct sk_buff *ip4ip6_gro_receive(struct list_head *head,
308 /* Common GRO receive for SIT and IP6IP6 */
310 if (NAPI_GRO_CB(skb)->encap_mark) {
311 NAPI_GRO_CB(skb)->flush = 1;
315 NAPI_GRO_CB(skb)->encap_mark = 1;
317 return inet_gro_receive(head, skb);
320 INDIRECT_CALLABLE_SCOPE int ipv6_gro_complete(struct sk_buff *skb, int nhoff)
322 const struct net_offload *ops;
327 if (skb->encapsulation) {
328 skb_set_inner_protocol(skb, cpu_to_be16(ETH_P_IPV6));
329 skb_set_inner_network_header(skb, nhoff);
332 payload_len = skb->len - nhoff - sizeof(*iph);
333 if (unlikely(payload_len > IPV6_MAXPLEN)) {
334 struct hop_jumbo_hdr *hop_jumbo;
335 int hoplen = sizeof(*hop_jumbo);
337 /* Move network header left */
338 memmove(skb_mac_header(skb) - hoplen, skb_mac_header(skb),
339 skb->transport_header - skb->mac_header);
342 skb->mac_header -= hoplen;
343 skb->network_header -= hoplen;
344 iph = (struct ipv6hdr *)(skb->data + nhoff);
345 hop_jumbo = (struct hop_jumbo_hdr *)(iph + 1);
347 /* Build hop-by-hop options */
348 hop_jumbo->nexthdr = iph->nexthdr;
349 hop_jumbo->hdrlen = 0;
350 hop_jumbo->tlv_type = IPV6_TLV_JUMBO;
351 hop_jumbo->tlv_len = 4;
352 hop_jumbo->jumbo_payload_len = htonl(payload_len + hoplen);
354 iph->nexthdr = NEXTHDR_HOP;
355 iph->payload_len = 0;
357 iph = (struct ipv6hdr *)(skb->data + nhoff);
358 iph->payload_len = htons(payload_len);
361 nhoff += sizeof(*iph) + ipv6_exthdrs_len(iph, &ops);
362 if (WARN_ON(!ops || !ops->callbacks.gro_complete))
365 err = INDIRECT_CALL_L4(ops->callbacks.gro_complete, tcp6_gro_complete,
366 udp6_gro_complete, skb, nhoff);
372 static int sit_gro_complete(struct sk_buff *skb, int nhoff)
374 skb->encapsulation = 1;
375 skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4;
376 return ipv6_gro_complete(skb, nhoff);
379 static int ip6ip6_gro_complete(struct sk_buff *skb, int nhoff)
381 skb->encapsulation = 1;
382 skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP6;
383 return ipv6_gro_complete(skb, nhoff);
386 static int ip4ip6_gro_complete(struct sk_buff *skb, int nhoff)
388 skb->encapsulation = 1;
389 skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP6;
390 return inet_gro_complete(skb, nhoff);
393 static struct packet_offload ipv6_packet_offload __read_mostly = {
394 .type = cpu_to_be16(ETH_P_IPV6),
396 .gso_segment = ipv6_gso_segment,
397 .gro_receive = ipv6_gro_receive,
398 .gro_complete = ipv6_gro_complete,
402 static struct sk_buff *sit_gso_segment(struct sk_buff *skb,
403 netdev_features_t features)
405 if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP4))
406 return ERR_PTR(-EINVAL);
408 return ipv6_gso_segment(skb, features);
411 static struct sk_buff *ip4ip6_gso_segment(struct sk_buff *skb,
412 netdev_features_t features)
414 if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP6))
415 return ERR_PTR(-EINVAL);
417 return inet_gso_segment(skb, features);
420 static struct sk_buff *ip6ip6_gso_segment(struct sk_buff *skb,
421 netdev_features_t features)
423 if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP6))
424 return ERR_PTR(-EINVAL);
426 return ipv6_gso_segment(skb, features);
429 static const struct net_offload sit_offload = {
431 .gso_segment = sit_gso_segment,
432 .gro_receive = sit_ip6ip6_gro_receive,
433 .gro_complete = sit_gro_complete,
437 static const struct net_offload ip4ip6_offload = {
439 .gso_segment = ip4ip6_gso_segment,
440 .gro_receive = ip4ip6_gro_receive,
441 .gro_complete = ip4ip6_gro_complete,
445 static const struct net_offload ip6ip6_offload = {
447 .gso_segment = ip6ip6_gso_segment,
448 .gro_receive = sit_ip6ip6_gro_receive,
449 .gro_complete = ip6ip6_gro_complete,
452 static int __init ipv6_offload_init(void)
455 if (tcpv6_offload_init() < 0)
456 pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
457 if (ipv6_exthdrs_offload_init() < 0)
458 pr_crit("%s: Cannot add EXTHDRS protocol offload\n", __func__);
460 dev_add_offload(&ipv6_packet_offload);
462 inet_add_offload(&sit_offload, IPPROTO_IPV6);
463 inet6_add_offload(&ip6ip6_offload, IPPROTO_IPV6);
464 inet6_add_offload(&ip4ip6_offload, IPPROTO_IPIP);
469 fs_initcall(ipv6_offload_init);