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>
20 #include "ip6_offload.h"
22 static int ipv6_gso_pull_exthdrs(struct sk_buff *skb, int proto)
24 const struct net_offload *ops = NULL;
27 struct ipv6_opt_hdr *opth;
30 if (proto != NEXTHDR_HOP) {
31 ops = rcu_dereference(inet6_offloads[proto]);
36 if (!(ops->flags & INET6_PROTO_GSO_EXTHDR))
40 if (unlikely(!pskb_may_pull(skb, 8)))
43 opth = (void *)skb->data;
44 len = ipv6_optlen(opth);
46 if (unlikely(!pskb_may_pull(skb, len)))
49 proto = opth->nexthdr;
56 static int ipv6_gso_send_check(struct sk_buff *skb)
58 const struct ipv6hdr *ipv6h;
59 const struct net_offload *ops;
62 if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h))))
65 ipv6h = ipv6_hdr(skb);
66 __skb_pull(skb, sizeof(*ipv6h));
67 err = -EPROTONOSUPPORT;
70 ops = rcu_dereference(inet6_offloads[
71 ipv6_gso_pull_exthdrs(skb, ipv6h->nexthdr)]);
73 if (likely(ops && ops->callbacks.gso_send_check)) {
74 skb_reset_transport_header(skb);
75 err = ops->callbacks.gso_send_check(skb);
83 static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,
84 netdev_features_t features)
86 struct sk_buff *segs = ERR_PTR(-EINVAL);
87 struct ipv6hdr *ipv6h;
88 const struct net_offload *ops;
90 struct frag_hdr *fptr;
91 unsigned int unfrag_ip6hlen;
96 if (unlikely(skb_shinfo(skb)->gso_type &
107 if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h))))
110 tunnel = skb->encapsulation;
111 ipv6h = ipv6_hdr(skb);
112 __skb_pull(skb, sizeof(*ipv6h));
113 segs = ERR_PTR(-EPROTONOSUPPORT);
115 proto = ipv6_gso_pull_exthdrs(skb, ipv6h->nexthdr);
117 ops = rcu_dereference(inet6_offloads[proto]);
118 if (likely(ops && ops->callbacks.gso_segment)) {
119 skb_reset_transport_header(skb);
120 segs = ops->callbacks.gso_segment(skb, features);
127 for (skb = segs; skb; skb = skb->next) {
128 ipv6h = ipv6_hdr(skb);
129 ipv6h->payload_len = htons(skb->len - skb->mac_len -
131 if (!tunnel && proto == IPPROTO_UDP) {
132 unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr);
133 fptr = (struct frag_hdr *)(skb_network_header(skb) +
135 fptr->frag_off = htons(offset);
136 if (skb->next != NULL)
137 fptr->frag_off |= htons(IP6_MF);
138 offset += (ntohs(ipv6h->payload_len) -
139 sizeof(struct frag_hdr));
147 static struct sk_buff **ipv6_gro_receive(struct sk_buff **head,
150 const struct net_offload *ops;
151 struct sk_buff **pp = NULL;
161 off = skb_gro_offset(skb);
162 hlen = off + sizeof(*iph);
163 iph = skb_gro_header_fast(skb, off);
164 if (skb_gro_header_hard(skb, hlen)) {
165 iph = skb_gro_header_slow(skb, hlen, off);
170 skb_gro_pull(skb, sizeof(*iph));
171 skb_set_transport_header(skb, skb_gro_offset(skb));
173 flush += ntohs(iph->payload_len) != skb_gro_len(skb);
176 proto = iph->nexthdr;
177 ops = rcu_dereference(inet6_offloads[proto]);
178 if (!ops || !ops->callbacks.gro_receive) {
179 __pskb_pull(skb, skb_gro_offset(skb));
180 proto = ipv6_gso_pull_exthdrs(skb, proto);
181 skb_gro_pull(skb, -skb_transport_offset(skb));
182 skb_reset_transport_header(skb);
183 __skb_push(skb, skb_gro_offset(skb));
185 ops = rcu_dereference(inet6_offloads[proto]);
186 if (!ops || !ops->callbacks.gro_receive)
192 NAPI_GRO_CB(skb)->proto = proto;
195 nlen = skb_network_header_len(skb);
197 for (p = *head; p; p = p->next) {
198 const struct ipv6hdr *iph2;
199 __be32 first_word; /* <Version:4><Traffic_Class:8><Flow_Label:20> */
201 if (!NAPI_GRO_CB(p)->same_flow)
205 first_word = *(__be32 *)iph ^ *(__be32 *)iph2 ;
207 /* All fields must match except length and Traffic Class. */
208 if (nlen != skb_network_header_len(p) ||
209 (first_word & htonl(0xF00FFFFF)) ||
210 memcmp(&iph->nexthdr, &iph2->nexthdr,
211 nlen - offsetof(struct ipv6hdr, nexthdr))) {
212 NAPI_GRO_CB(p)->same_flow = 0;
215 /* flush if Traffic Class fields are different */
216 NAPI_GRO_CB(p)->flush |= !!(first_word & htonl(0x0FF00000));
217 NAPI_GRO_CB(p)->flush |= flush;
220 NAPI_GRO_CB(skb)->flush |= flush;
223 skb_postpull_rcsum(skb, iph, skb_network_header_len(skb));
225 pp = ops->callbacks.gro_receive(head, skb);
233 NAPI_GRO_CB(skb)->flush |= flush;
238 static int ipv6_gro_complete(struct sk_buff *skb)
240 const struct net_offload *ops;
241 struct ipv6hdr *iph = ipv6_hdr(skb);
244 iph->payload_len = htons(skb->len - skb_network_offset(skb) -
248 ops = rcu_dereference(inet6_offloads[NAPI_GRO_CB(skb)->proto]);
249 if (WARN_ON(!ops || !ops->callbacks.gro_complete))
252 err = ops->callbacks.gro_complete(skb);
260 static struct packet_offload ipv6_packet_offload __read_mostly = {
261 .type = cpu_to_be16(ETH_P_IPV6),
263 .gso_send_check = ipv6_gso_send_check,
264 .gso_segment = ipv6_gso_segment,
265 .gro_receive = ipv6_gro_receive,
266 .gro_complete = ipv6_gro_complete,
270 static int __init ipv6_offload_init(void)
273 if (tcpv6_offload_init() < 0)
274 pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
275 if (udp_offload_init() < 0)
276 pr_crit("%s: Cannot add UDP protocol offload\n", __func__);
277 if (ipv6_exthdrs_offload_init() < 0)
278 pr_crit("%s: Cannot add EXTHDRS protocol offload\n", __func__);
280 dev_add_offload(&ipv6_packet_offload);
284 fs_initcall(ipv6_offload_init);