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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>
16
17#include <net/protocol.h>
18#include <net/ipv6.h>
19
20#include "ip6_offload.h"
21
22static int ipv6_gso_pull_exthdrs(struct sk_buff *skb, int proto)
23{
24 const struct net_offload *ops = NULL;
25
26 for (;;) {
27 struct ipv6_opt_hdr *opth;
28 int len;
29
30 if (proto != NEXTHDR_HOP) {
31 ops = rcu_dereference(inet6_offloads[proto]);
32
33 if (unlikely(!ops))
34 break;
35
36 if (!(ops->flags & INET6_PROTO_GSO_EXTHDR))
37 break;
38 }
39
40 if (unlikely(!pskb_may_pull(skb, 8)))
41 break;
42
43 opth = (void *)skb->data;
44 len = ipv6_optlen(opth);
45
46 if (unlikely(!pskb_may_pull(skb, len)))
47 break;
48
49 proto = opth->nexthdr;
50 __skb_pull(skb, len);
51 }
52
53 return proto;
54}
55
56static int ipv6_gso_send_check(struct sk_buff *skb)
57{
58 const struct ipv6hdr *ipv6h;
59 const struct net_offload *ops;
60 int err = -EINVAL;
61
62 if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h))))
63 goto out;
64
65 ipv6h = ipv6_hdr(skb);
66 __skb_pull(skb, sizeof(*ipv6h));
67 err = -EPROTONOSUPPORT;
68
69 rcu_read_lock();
70 ops = rcu_dereference(inet6_offloads[
71 ipv6_gso_pull_exthdrs(skb, ipv6h->nexthdr)]);
72
73 if (likely(ops && ops->callbacks.gso_send_check)) {
74 skb_reset_transport_header(skb);
75 err = ops->callbacks.gso_send_check(skb);
76 }
77 rcu_read_unlock();
78
79out:
80 return err;
81}
82
83static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,
84 netdev_features_t features)
85{
86 struct sk_buff *segs = ERR_PTR(-EINVAL);
87 struct ipv6hdr *ipv6h;
88 const struct net_offload *ops;
89 int proto;
90 struct frag_hdr *fptr;
91 unsigned int unfrag_ip6hlen;
92 u8 *prevhdr;
93 int offset = 0;
94 bool tunnel;
95
96 if (unlikely(skb_shinfo(skb)->gso_type &
97 ~(SKB_GSO_UDP |
98 SKB_GSO_DODGY |
99 SKB_GSO_TCP_ECN |
100 SKB_GSO_GRE |
101 SKB_GSO_UDP_TUNNEL |
102 SKB_GSO_MPLS |
103 SKB_GSO_TCPV6 |
104 0)))
105 goto out;
106
107 if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h))))
108 goto out;
109
110 tunnel = skb->encapsulation;
111 ipv6h = ipv6_hdr(skb);
112 __skb_pull(skb, sizeof(*ipv6h));
113 segs = ERR_PTR(-EPROTONOSUPPORT);
114
115 proto = ipv6_gso_pull_exthdrs(skb, ipv6h->nexthdr);
116 rcu_read_lock();
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);
121 }
122 rcu_read_unlock();
123
124 if (IS_ERR(segs))
125 goto out;
126
127 for (skb = segs; skb; skb = skb->next) {
128 ipv6h = ipv6_hdr(skb);
129 ipv6h->payload_len = htons(skb->len - skb->mac_len -
130 sizeof(*ipv6h));
131 if (!tunnel && proto == IPPROTO_UDP) {
132 unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr);
133 fptr = (struct frag_hdr *)(skb_network_header(skb) +
134 unfrag_ip6hlen);
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));
140 }
141 }
142
143out:
144 return segs;
145}
146
147static struct sk_buff **ipv6_gro_receive(struct sk_buff **head,
148 struct sk_buff *skb)
149{
150 const struct net_offload *ops;
151 struct sk_buff **pp = NULL;
152 struct sk_buff *p;
153 struct ipv6hdr *iph;
154 unsigned int nlen;
155 unsigned int hlen;
156 unsigned int off;
157 int flush = 1;
158 int proto;
159 __wsum csum;
160
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);
166 if (unlikely(!iph))
167 goto out;
168 }
169
170 skb_gro_pull(skb, sizeof(*iph));
171 skb_set_transport_header(skb, skb_gro_offset(skb));
172
173 flush += ntohs(iph->payload_len) != skb_gro_len(skb);
174
175 rcu_read_lock();
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));
184
185 ops = rcu_dereference(inet6_offloads[proto]);
186 if (!ops || !ops->callbacks.gro_receive)
187 goto out_unlock;
188
189 iph = ipv6_hdr(skb);
190 }
191
192 NAPI_GRO_CB(skb)->proto = proto;
193
194 flush--;
195 nlen = skb_network_header_len(skb);
196
197 for (p = *head; p; p = p->next) {
198 const struct ipv6hdr *iph2;
199 __be32 first_word;
200
201 if (!NAPI_GRO_CB(p)->same_flow)
202 continue;
203
204 iph2 = ipv6_hdr(p);
205 first_word = *(__be32 *)iph ^ *(__be32 *)iph2 ;
206
207
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;
213 continue;
214 }
215
216 NAPI_GRO_CB(p)->flush |= !!(first_word & htonl(0x0FF00000));
217 NAPI_GRO_CB(p)->flush |= flush;
218 }
219
220 NAPI_GRO_CB(skb)->flush |= flush;
221
222 csum = skb->csum;
223 skb_postpull_rcsum(skb, iph, skb_network_header_len(skb));
224
225 pp = ops->callbacks.gro_receive(head, skb);
226
227 skb->csum = csum;
228
229out_unlock:
230 rcu_read_unlock();
231
232out:
233 NAPI_GRO_CB(skb)->flush |= flush;
234
235 return pp;
236}
237
238static int ipv6_gro_complete(struct sk_buff *skb)
239{
240 const struct net_offload *ops;
241 struct ipv6hdr *iph = ipv6_hdr(skb);
242 int err = -ENOSYS;
243
244 iph->payload_len = htons(skb->len - skb_network_offset(skb) -
245 sizeof(*iph));
246
247 rcu_read_lock();
248 ops = rcu_dereference(inet6_offloads[NAPI_GRO_CB(skb)->proto]);
249 if (WARN_ON(!ops || !ops->callbacks.gro_complete))
250 goto out_unlock;
251
252 err = ops->callbacks.gro_complete(skb);
253
254out_unlock:
255 rcu_read_unlock();
256
257 return err;
258}
259
260static struct packet_offload ipv6_packet_offload __read_mostly = {
261 .type = cpu_to_be16(ETH_P_IPV6),
262 .callbacks = {
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,
267 },
268};
269
270static int __init ipv6_offload_init(void)
271{
272
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__);
279
280 dev_add_offload(&ipv6_packet_offload);
281 return 0;
282}
283
284fs_initcall(ipv6_offload_init);
285
