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Commit | Line | Data |
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d1da932e VY |
1 | /* |
2 | * IPV6 GSO/GRO offload support | |
3 | * Linux INET6 implementation | |
4 | * | |
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. | |
9 | */ | |
10 | ||
11 | #include <linux/kernel.h> | |
12 | #include <linux/socket.h> | |
13 | #include <linux/netdevice.h> | |
14 | #include <linux/skbuff.h> | |
c6b641a4 | 15 | #include <linux/printk.h> |
d1da932e VY |
16 | |
17 | #include <net/protocol.h> | |
18 | #include <net/ipv6.h> | |
19 | ||
20 | #include "ip6_offload.h" | |
21 | ||
22 | static 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 | ||
56 | static 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 | ||
f191a1d1 | 73 | if (likely(ops && ops->callbacks.gso_send_check)) { |
d1da932e | 74 | skb_reset_transport_header(skb); |
f191a1d1 | 75 | err = ops->callbacks.gso_send_check(skb); |
d1da932e VY |
76 | } |
77 | rcu_read_unlock(); | |
78 | ||
79 | out: | |
80 | return err; | |
81 | } | |
82 | ||
83 | static 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 | ||
95 | if (!(features & NETIF_F_V6_CSUM)) | |
96 | features &= ~NETIF_F_SG; | |
97 | ||
98 | if (unlikely(skb_shinfo(skb)->gso_type & | |
99 | ~(SKB_GSO_UDP | | |
100 | SKB_GSO_DODGY | | |
101 | SKB_GSO_TCP_ECN | | |
68c33163 | 102 | SKB_GSO_GRE | |
d1da932e VY |
103 | SKB_GSO_TCPV6 | |
104 | 0))) | |
105 | goto out; | |
106 | ||
107 | if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h)))) | |
108 | goto out; | |
109 | ||
110 | ipv6h = ipv6_hdr(skb); | |
111 | __skb_pull(skb, sizeof(*ipv6h)); | |
112 | segs = ERR_PTR(-EPROTONOSUPPORT); | |
113 | ||
114 | proto = ipv6_gso_pull_exthdrs(skb, ipv6h->nexthdr); | |
115 | rcu_read_lock(); | |
116 | ops = rcu_dereference(inet6_offloads[proto]); | |
f191a1d1 | 117 | if (likely(ops && ops->callbacks.gso_segment)) { |
d1da932e | 118 | skb_reset_transport_header(skb); |
f191a1d1 | 119 | segs = ops->callbacks.gso_segment(skb, features); |
d1da932e VY |
120 | } |
121 | rcu_read_unlock(); | |
122 | ||
123 | if (IS_ERR(segs)) | |
124 | goto out; | |
125 | ||
126 | for (skb = segs; skb; skb = skb->next) { | |
127 | ipv6h = ipv6_hdr(skb); | |
128 | ipv6h->payload_len = htons(skb->len - skb->mac_len - | |
129 | sizeof(*ipv6h)); | |
130 | if (proto == IPPROTO_UDP) { | |
131 | unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr); | |
132 | fptr = (struct frag_hdr *)(skb_network_header(skb) + | |
133 | unfrag_ip6hlen); | |
134 | fptr->frag_off = htons(offset); | |
135 | if (skb->next != NULL) | |
136 | fptr->frag_off |= htons(IP6_MF); | |
137 | offset += (ntohs(ipv6h->payload_len) - | |
138 | sizeof(struct frag_hdr)); | |
139 | } | |
140 | } | |
141 | ||
142 | out: | |
143 | return segs; | |
144 | } | |
145 | ||
146 | static struct sk_buff **ipv6_gro_receive(struct sk_buff **head, | |
147 | struct sk_buff *skb) | |
148 | { | |
149 | const struct net_offload *ops; | |
150 | struct sk_buff **pp = NULL; | |
151 | struct sk_buff *p; | |
152 | struct ipv6hdr *iph; | |
153 | unsigned int nlen; | |
154 | unsigned int hlen; | |
155 | unsigned int off; | |
156 | int flush = 1; | |
157 | int proto; | |
158 | __wsum csum; | |
159 | ||
160 | off = skb_gro_offset(skb); | |
161 | hlen = off + sizeof(*iph); | |
162 | iph = skb_gro_header_fast(skb, off); | |
163 | if (skb_gro_header_hard(skb, hlen)) { | |
164 | iph = skb_gro_header_slow(skb, hlen, off); | |
165 | if (unlikely(!iph)) | |
166 | goto out; | |
167 | } | |
168 | ||
169 | skb_gro_pull(skb, sizeof(*iph)); | |
170 | skb_set_transport_header(skb, skb_gro_offset(skb)); | |
171 | ||
172 | flush += ntohs(iph->payload_len) != skb_gro_len(skb); | |
173 | ||
174 | rcu_read_lock(); | |
175 | proto = iph->nexthdr; | |
176 | ops = rcu_dereference(inet6_offloads[proto]); | |
f191a1d1 | 177 | if (!ops || !ops->callbacks.gro_receive) { |
d1da932e VY |
178 | __pskb_pull(skb, skb_gro_offset(skb)); |
179 | proto = ipv6_gso_pull_exthdrs(skb, proto); | |
180 | skb_gro_pull(skb, -skb_transport_offset(skb)); | |
181 | skb_reset_transport_header(skb); | |
182 | __skb_push(skb, skb_gro_offset(skb)); | |
183 | ||
184 | ops = rcu_dereference(inet6_offloads[proto]); | |
f191a1d1 | 185 | if (!ops || !ops->callbacks.gro_receive) |
d1da932e VY |
186 | goto out_unlock; |
187 | ||
188 | iph = ipv6_hdr(skb); | |
189 | } | |
190 | ||
191 | NAPI_GRO_CB(skb)->proto = proto; | |
192 | ||
193 | flush--; | |
194 | nlen = skb_network_header_len(skb); | |
195 | ||
196 | for (p = *head; p; p = p->next) { | |
197 | const struct ipv6hdr *iph2; | |
198 | __be32 first_word; /* <Version:4><Traffic_Class:8><Flow_Label:20> */ | |
199 | ||
200 | if (!NAPI_GRO_CB(p)->same_flow) | |
201 | continue; | |
202 | ||
203 | iph2 = ipv6_hdr(p); | |
204 | first_word = *(__be32 *)iph ^ *(__be32 *)iph2 ; | |
205 | ||
206 | /* All fields must match except length and Traffic Class. */ | |
207 | if (nlen != skb_network_header_len(p) || | |
208 | (first_word & htonl(0xF00FFFFF)) || | |
209 | memcmp(&iph->nexthdr, &iph2->nexthdr, | |
210 | nlen - offsetof(struct ipv6hdr, nexthdr))) { | |
211 | NAPI_GRO_CB(p)->same_flow = 0; | |
212 | continue; | |
213 | } | |
214 | /* flush if Traffic Class fields are different */ | |
215 | NAPI_GRO_CB(p)->flush |= !!(first_word & htonl(0x0FF00000)); | |
216 | NAPI_GRO_CB(p)->flush |= flush; | |
217 | } | |
218 | ||
219 | NAPI_GRO_CB(skb)->flush |= flush; | |
220 | ||
221 | csum = skb->csum; | |
222 | skb_postpull_rcsum(skb, iph, skb_network_header_len(skb)); | |
223 | ||
f191a1d1 | 224 | pp = ops->callbacks.gro_receive(head, skb); |
d1da932e VY |
225 | |
226 | skb->csum = csum; | |
227 | ||
228 | out_unlock: | |
229 | rcu_read_unlock(); | |
230 | ||
231 | out: | |
232 | NAPI_GRO_CB(skb)->flush |= flush; | |
233 | ||
234 | return pp; | |
235 | } | |
236 | ||
237 | static int ipv6_gro_complete(struct sk_buff *skb) | |
238 | { | |
239 | const struct net_offload *ops; | |
240 | struct ipv6hdr *iph = ipv6_hdr(skb); | |
241 | int err = -ENOSYS; | |
242 | ||
243 | iph->payload_len = htons(skb->len - skb_network_offset(skb) - | |
244 | sizeof(*iph)); | |
245 | ||
246 | rcu_read_lock(); | |
247 | ops = rcu_dereference(inet6_offloads[NAPI_GRO_CB(skb)->proto]); | |
f191a1d1 | 248 | if (WARN_ON(!ops || !ops->callbacks.gro_complete)) |
d1da932e VY |
249 | goto out_unlock; |
250 | ||
f191a1d1 | 251 | err = ops->callbacks.gro_complete(skb); |
d1da932e VY |
252 | |
253 | out_unlock: | |
254 | rcu_read_unlock(); | |
255 | ||
256 | return err; | |
257 | } | |
258 | ||
259 | static struct packet_offload ipv6_packet_offload __read_mostly = { | |
260 | .type = cpu_to_be16(ETH_P_IPV6), | |
f191a1d1 VY |
261 | .callbacks = { |
262 | .gso_send_check = ipv6_gso_send_check, | |
263 | .gso_segment = ipv6_gso_segment, | |
264 | .gro_receive = ipv6_gro_receive, | |
265 | .gro_complete = ipv6_gro_complete, | |
266 | }, | |
d1da932e VY |
267 | }; |
268 | ||
c6b641a4 | 269 | static int __init ipv6_offload_init(void) |
d1da932e | 270 | { |
c6b641a4 VY |
271 | |
272 | if (tcpv6_offload_init() < 0) | |
273 | pr_crit("%s: Cannot add TCP protocol offload\n", __func__); | |
274 | if (udp_offload_init() < 0) | |
275 | pr_crit("%s: Cannot add UDP protocol offload\n", __func__); | |
276 | if (ipv6_exthdrs_offload_init() < 0) | |
277 | pr_crit("%s: Cannot add EXTHDRS protocol offload\n", __func__); | |
278 | ||
d1da932e | 279 | dev_add_offload(&ipv6_packet_offload); |
c6b641a4 | 280 | return 0; |
d1da932e VY |
281 | } |
282 | ||
c6b641a4 | 283 | fs_initcall(ipv6_offload_init); |