2 * IPV6 GSO/GRO offload support
3 * Linux INET6 implementation
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.
11 #include <linux/kernel.h>
12 #include <linux/socket.h>
13 #include <linux/netdevice.h>
14 #include <linux/skbuff.h>
15 #include <linux/printk.h>
17 #include <net/protocol.h>
19 #include <net/inet_common.h>
21 #include "ip6_offload.h"
23 static int ipv6_gso_pull_exthdrs(struct sk_buff *skb, int proto)
25 const struct net_offload *ops = NULL;
28 struct ipv6_opt_hdr *opth;
31 if (proto != NEXTHDR_HOP) {
32 ops = rcu_dereference(inet6_offloads[proto]);
37 if (!(ops->flags & INET6_PROTO_GSO_EXTHDR))
41 if (unlikely(!pskb_may_pull(skb, 8)))
44 opth = (void *)skb->data;
45 len = ipv6_optlen(opth);
47 if (unlikely(!pskb_may_pull(skb, len)))
50 opth = (void *)skb->data;
51 proto = opth->nexthdr;
58 static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,
59 netdev_features_t features)
61 struct sk_buff *segs = ERR_PTR(-EINVAL);
62 struct ipv6hdr *ipv6h;
63 const struct net_offload *ops;
65 struct frag_hdr *fptr;
66 unsigned int payload_len;
73 skb_reset_network_header(skb);
74 nhoff = skb_network_header(skb) - skb_mac_header(skb);
75 if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h))))
78 encap = SKB_GSO_CB(skb)->encap_level > 0;
80 features &= skb->dev->hw_enc_features;
81 SKB_GSO_CB(skb)->encap_level += sizeof(*ipv6h);
83 ipv6h = ipv6_hdr(skb);
84 __skb_pull(skb, sizeof(*ipv6h));
85 segs = ERR_PTR(-EPROTONOSUPPORT);
87 proto = ipv6_gso_pull_exthdrs(skb, ipv6h->nexthdr);
89 if (skb->encapsulation &&
90 skb_shinfo(skb)->gso_type & (SKB_GSO_IPXIP4 | SKB_GSO_IPXIP6))
91 udpfrag = proto == IPPROTO_UDP && encap &&
92 (skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
94 udpfrag = proto == IPPROTO_UDP && !skb->encapsulation &&
95 (skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
97 ops = rcu_dereference(inet6_offloads[proto]);
98 if (likely(ops && ops->callbacks.gso_segment)) {
99 skb_reset_transport_header(skb);
100 segs = ops->callbacks.gso_segment(skb, features);
103 if (IS_ERR_OR_NULL(segs))
106 gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);
108 for (skb = segs; skb; skb = skb->next) {
109 ipv6h = (struct ipv6hdr *)(skb_mac_header(skb) + nhoff);
110 if (gso_partial && skb_is_gso(skb))
111 payload_len = skb_shinfo(skb)->gso_size +
112 SKB_GSO_CB(skb)->data_offset +
113 skb->head - (unsigned char *)(ipv6h + 1);
115 payload_len = skb->len - nhoff - sizeof(*ipv6h);
116 ipv6h->payload_len = htons(payload_len);
117 skb->network_header = (u8 *)ipv6h - skb->head;
118 skb_reset_mac_len(skb);
121 int err = ip6_find_1stfragopt(skb, &prevhdr);
123 kfree_skb_list(segs);
126 fptr = (struct frag_hdr *)((u8 *)ipv6h + err);
127 fptr->frag_off = htons(offset);
129 fptr->frag_off |= htons(IP6_MF);
130 offset += (ntohs(ipv6h->payload_len) -
131 sizeof(struct frag_hdr));
134 skb_reset_inner_headers(skb);
141 /* Return the total length of all the extension hdrs, following the same
142 * logic in ipv6_gso_pull_exthdrs() when parsing ext-hdrs.
144 static int ipv6_exthdrs_len(struct ipv6hdr *iph,
145 const struct net_offload **opps)
147 struct ipv6_opt_hdr *opth = (void *)iph;
148 int len = 0, proto, optlen = sizeof(*iph);
150 proto = iph->nexthdr;
152 if (proto != NEXTHDR_HOP) {
153 *opps = rcu_dereference(inet6_offloads[proto]);
154 if (unlikely(!(*opps)))
156 if (!((*opps)->flags & INET6_PROTO_GSO_EXTHDR))
159 opth = (void *)opth + optlen;
160 optlen = ipv6_optlen(opth);
162 proto = opth->nexthdr;
167 static struct sk_buff *ipv6_gro_receive(struct list_head *head,
170 const struct net_offload *ops;
171 struct sk_buff *pp = NULL;
180 off = skb_gro_offset(skb);
181 hlen = off + sizeof(*iph);
182 iph = skb_gro_header_fast(skb, off);
183 if (skb_gro_header_hard(skb, hlen)) {
184 iph = skb_gro_header_slow(skb, hlen, off);
189 skb_set_network_header(skb, off);
190 skb_gro_pull(skb, sizeof(*iph));
191 skb_set_transport_header(skb, skb_gro_offset(skb));
193 flush += ntohs(iph->payload_len) != skb_gro_len(skb);
196 proto = iph->nexthdr;
197 ops = rcu_dereference(inet6_offloads[proto]);
198 if (!ops || !ops->callbacks.gro_receive) {
199 __pskb_pull(skb, skb_gro_offset(skb));
200 skb_gro_frag0_invalidate(skb);
201 proto = ipv6_gso_pull_exthdrs(skb, proto);
202 skb_gro_pull(skb, -skb_transport_offset(skb));
203 skb_reset_transport_header(skb);
204 __skb_push(skb, skb_gro_offset(skb));
206 ops = rcu_dereference(inet6_offloads[proto]);
207 if (!ops || !ops->callbacks.gro_receive)
213 NAPI_GRO_CB(skb)->proto = proto;
216 nlen = skb_network_header_len(skb);
218 list_for_each_entry(p, head, list) {
219 const struct ipv6hdr *iph2;
220 __be32 first_word; /* <Version:4><Traffic_Class:8><Flow_Label:20> */
222 if (!NAPI_GRO_CB(p)->same_flow)
225 iph2 = (struct ipv6hdr *)(p->data + off);
226 first_word = *(__be32 *)iph ^ *(__be32 *)iph2;
228 /* All fields must match except length and Traffic Class.
229 * XXX skbs on the gro_list have all been parsed and pulled
230 * already so we don't need to compare nlen
231 * (nlen != (sizeof(*iph2) + ipv6_exthdrs_len(iph2, &ops)))
232 * memcmp() alone below is suffcient, right?
234 if ((first_word & htonl(0xF00FFFFF)) ||
235 memcmp(&iph->nexthdr, &iph2->nexthdr,
236 nlen - offsetof(struct ipv6hdr, nexthdr))) {
237 NAPI_GRO_CB(p)->same_flow = 0;
240 /* flush if Traffic Class fields are different */
241 NAPI_GRO_CB(p)->flush |= !!(first_word & htonl(0x0FF00000));
242 NAPI_GRO_CB(p)->flush |= flush;
244 /* If the previous IP ID value was based on an atomic
245 * datagram we can overwrite the value and ignore it.
247 if (NAPI_GRO_CB(skb)->is_atomic)
248 NAPI_GRO_CB(p)->flush_id = 0;
251 NAPI_GRO_CB(skb)->is_atomic = true;
252 NAPI_GRO_CB(skb)->flush |= flush;
254 skb_gro_postpull_rcsum(skb, iph, nlen);
256 pp = call_gro_receive(ops->callbacks.gro_receive, head, skb);
262 skb_gro_flush_final(skb, pp, flush);
267 static struct sk_buff *sit_ip6ip6_gro_receive(struct list_head *head,
270 /* Common GRO receive for SIT and IP6IP6 */
272 if (NAPI_GRO_CB(skb)->encap_mark) {
273 NAPI_GRO_CB(skb)->flush = 1;
277 NAPI_GRO_CB(skb)->encap_mark = 1;
279 return ipv6_gro_receive(head, skb);
282 static struct sk_buff *ip4ip6_gro_receive(struct list_head *head,
285 /* Common GRO receive for SIT and IP6IP6 */
287 if (NAPI_GRO_CB(skb)->encap_mark) {
288 NAPI_GRO_CB(skb)->flush = 1;
292 NAPI_GRO_CB(skb)->encap_mark = 1;
294 return inet_gro_receive(head, skb);
297 static int ipv6_gro_complete(struct sk_buff *skb, int nhoff)
299 const struct net_offload *ops;
300 struct ipv6hdr *iph = (struct ipv6hdr *)(skb->data + nhoff);
303 if (skb->encapsulation) {
304 skb_set_inner_protocol(skb, cpu_to_be16(ETH_P_IPV6));
305 skb_set_inner_network_header(skb, nhoff);
308 iph->payload_len = htons(skb->len - nhoff - sizeof(*iph));
312 nhoff += sizeof(*iph) + ipv6_exthdrs_len(iph, &ops);
313 if (WARN_ON(!ops || !ops->callbacks.gro_complete))
316 err = ops->callbacks.gro_complete(skb, nhoff);
324 static int sit_gro_complete(struct sk_buff *skb, int nhoff)
326 skb->encapsulation = 1;
327 skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4;
328 return ipv6_gro_complete(skb, nhoff);
331 static int ip6ip6_gro_complete(struct sk_buff *skb, int nhoff)
333 skb->encapsulation = 1;
334 skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP6;
335 return ipv6_gro_complete(skb, nhoff);
338 static int ip4ip6_gro_complete(struct sk_buff *skb, int nhoff)
340 skb->encapsulation = 1;
341 skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP6;
342 return inet_gro_complete(skb, nhoff);
345 static struct packet_offload ipv6_packet_offload __read_mostly = {
346 .type = cpu_to_be16(ETH_P_IPV6),
348 .gso_segment = ipv6_gso_segment,
349 .gro_receive = ipv6_gro_receive,
350 .gro_complete = ipv6_gro_complete,
354 static const struct net_offload sit_offload = {
356 .gso_segment = ipv6_gso_segment,
357 .gro_receive = sit_ip6ip6_gro_receive,
358 .gro_complete = sit_gro_complete,
362 static const struct net_offload ip4ip6_offload = {
364 .gso_segment = inet_gso_segment,
365 .gro_receive = ip4ip6_gro_receive,
366 .gro_complete = ip4ip6_gro_complete,
370 static const struct net_offload ip6ip6_offload = {
372 .gso_segment = ipv6_gso_segment,
373 .gro_receive = sit_ip6ip6_gro_receive,
374 .gro_complete = ip6ip6_gro_complete,
377 static int __init ipv6_offload_init(void)
380 if (tcpv6_offload_init() < 0)
381 pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
382 if (ipv6_exthdrs_offload_init() < 0)
383 pr_crit("%s: Cannot add EXTHDRS protocol offload\n", __func__);
385 dev_add_offload(&ipv6_packet_offload);
387 inet_add_offload(&sit_offload, IPPROTO_IPV6);
388 inet6_add_offload(&ip6ip6_offload, IPPROTO_IPV6);
389 inet6_add_offload(&ip4ip6_offload, IPPROTO_IPIP);
394 fs_initcall(ipv6_offload_init);