git.openwrt.org Git - openwrt/staging/blogic.git/blob

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 */

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>

18 #include <net/ipv6.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)

24 {

25 const struct net_offload *ops = NULL;

27 for (;;) {

28 struct ipv6_opt_hdr *opth;

29 int len;

31 if (proto != NEXTHDR_HOP) {

32 ops = rcu_dereference(inet6_offloads[proto]);

34 if (unlikely(!ops))

35 break;

37 if (!(ops->flags & INET6_PROTO_GSO_EXTHDR))

38 break;

39 }

41 if (unlikely(!pskb_may_pull(skb, 8)))

42 break;

44 opth = (void *)skb->data;

45 len = ipv6_optlen(opth);

47 if (unlikely(!pskb_may_pull(skb, len)))

48 break;

50 opth = (void *)skb->data;

51 proto = opth->nexthdr;

52 __skb_pull(skb, len);

53 }

55 return proto;

56 }

58 static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,

59 netdev_features_t features)

60 {

61 struct sk_buff *segs = ERR_PTR(-EINVAL);

62 struct ipv6hdr *ipv6h;

63 const struct net_offload *ops;

64 int proto;

65 struct frag_hdr *fptr;

66 unsigned int unfrag_ip6hlen;

67 unsigned int payload_len;

68 u8 *prevhdr;

69 int offset = 0;

70 bool encap, udpfrag;

71 int nhoff;

72 bool gso_partial;

74 skb_reset_network_header(skb);

75 nhoff = skb_network_header(skb) - skb_mac_header(skb);

76 if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h))))

77 goto out;

79 encap = SKB_GSO_CB(skb)->encap_level > 0;

80 if (encap)

81 features &= skb->dev->hw_enc_features;

82 SKB_GSO_CB(skb)->encap_level += sizeof(*ipv6h);

84 ipv6h = ipv6_hdr(skb);

85 __skb_pull(skb, sizeof(*ipv6h));

86 segs = ERR_PTR(-EPROTONOSUPPORT);

88 proto = ipv6_gso_pull_exthdrs(skb, ipv6h->nexthdr);

90 if (skb->encapsulation &&

91 skb_shinfo(skb)->gso_type & (SKB_GSO_IPXIP4 | SKB_GSO_IPXIP6))

92 udpfrag = proto == IPPROTO_UDP && encap;

93 else

94 udpfrag = proto == IPPROTO_UDP && !skb->encapsulation;

96 ops = rcu_dereference(inet6_offloads[proto]);

97 if (likely(ops && ops->callbacks.gso_segment)) {

98 skb_reset_transport_header(skb);

99 segs = ops->callbacks.gso_segment(skb, features);

100 }

101

102 if (IS_ERR(segs))

103 goto out;

104

105 gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);

106

107 for (skb = segs; skb; skb = skb->next) {

108 ipv6h = (struct ipv6hdr *)(skb_mac_header(skb) + nhoff);

109 if (gso_partial)

110 payload_len = skb_shinfo(skb)->gso_size +

111 SKB_GSO_CB(skb)->data_offset +

112 skb->head - (unsigned char *)(ipv6h + 1);

113 else

114 payload_len = skb->len - nhoff - sizeof(*ipv6h);

115 ipv6h->payload_len = htons(payload_len);

116 skb->network_header = (u8 *)ipv6h - skb->head;

117

118 if (udpfrag) {

119 unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr);

120 fptr = (struct frag_hdr *)((u8 *)ipv6h + unfrag_ip6hlen);

121 fptr->frag_off = htons(offset);

122 if (skb->next)

123 fptr->frag_off |= htons(IP6_MF);

124 offset += (ntohs(ipv6h->payload_len) -

125 sizeof(struct frag_hdr));

126 }

127 if (encap)

128 skb_reset_inner_headers(skb);

129 }

130

131 out:

132 return segs;

133 }

134

135 /* Return the total length of all the extension hdrs, following the same

136 * logic in ipv6_gso_pull_exthdrs() when parsing ext-hdrs.

137 */

138 static int ipv6_exthdrs_len(struct ipv6hdr *iph,

139 const struct net_offload **opps)

140 {

141 struct ipv6_opt_hdr *opth = (void *)iph;

142 int len = 0, proto, optlen = sizeof(*iph);

143

144 proto = iph->nexthdr;

145 for (;;) {

146 if (proto != NEXTHDR_HOP) {

147 *opps = rcu_dereference(inet6_offloads[proto]);

148 if (unlikely(!(*opps)))

149 break;

150 if (!((*opps)->flags & INET6_PROTO_GSO_EXTHDR))

151 break;

152 }

153 opth = (void *)opth + optlen;

154 optlen = ipv6_optlen(opth);

155 len += optlen;

156 proto = opth->nexthdr;

157 }

158 return len;

159 }

160

161 static struct sk_buff **ipv6_gro_receive(struct sk_buff **head,

162 struct sk_buff *skb)

163 {

164 const struct net_offload *ops;

165 struct sk_buff **pp = NULL;

166 struct sk_buff *p;

167 struct ipv6hdr *iph;

168 unsigned int nlen;

169 unsigned int hlen;

170 unsigned int off;

171 u16 flush = 1;

172 int proto;

173

174 off = skb_gro_offset(skb);

175 hlen = off + sizeof(*iph);

176 iph = skb_gro_header_fast(skb, off);

177 if (skb_gro_header_hard(skb, hlen)) {

178 iph = skb_gro_header_slow(skb, hlen, off);

179 if (unlikely(!iph))

180 goto out;

181 }

182

183 skb_set_network_header(skb, off);

184 skb_gro_pull(skb, sizeof(*iph));

185 skb_set_transport_header(skb, skb_gro_offset(skb));

186

187 flush += ntohs(iph->payload_len) != skb_gro_len(skb);

188

189 rcu_read_lock();

190 proto = iph->nexthdr;

191 ops = rcu_dereference(inet6_offloads[proto]);

192 if (!ops || !ops->callbacks.gro_receive) {

193 __pskb_pull(skb, skb_gro_offset(skb));

194 proto = ipv6_gso_pull_exthdrs(skb, proto);

195 skb_gro_pull(skb, -skb_transport_offset(skb));

196 skb_reset_transport_header(skb);

197 __skb_push(skb, skb_gro_offset(skb));

198

199 ops = rcu_dereference(inet6_offloads[proto]);

200 if (!ops || !ops->callbacks.gro_receive)

201 goto out_unlock;

202

203 iph = ipv6_hdr(skb);

204 }

205

206 NAPI_GRO_CB(skb)->proto = proto;

207

208 flush--;

209 nlen = skb_network_header_len(skb);

210

211 for (p = *head; p; p = p->next) {

212 const struct ipv6hdr *iph2;

213 __be32 first_word; /* <Version:4><Traffic_Class:8><Flow_Label:20> */

214

215 if (!NAPI_GRO_CB(p)->same_flow)

216 continue;

217

218 iph2 = (struct ipv6hdr *)(p->data + off);

219 first_word = *(__be32 *)iph ^ *(__be32 *)iph2;

220

221 /* All fields must match except length and Traffic Class.

222 * XXX skbs on the gro_list have all been parsed and pulled

223 * already so we don't need to compare nlen

224 * (nlen != (sizeof(*iph2) + ipv6_exthdrs_len(iph2, &ops)))

225 * memcmp() alone below is suffcient, right?

226 */

227 if ((first_word & htonl(0xF00FFFFF)) ||

228 memcmp(&iph->nexthdr, &iph2->nexthdr,

229 nlen - offsetof(struct ipv6hdr, nexthdr))) {

230 NAPI_GRO_CB(p)->same_flow = 0;

231 continue;

232 }

233 /* flush if Traffic Class fields are different */

234 NAPI_GRO_CB(p)->flush |= !!(first_word & htonl(0x0FF00000));

235 NAPI_GRO_CB(p)->flush |= flush;

236

237 /* If the previous IP ID value was based on an atomic

238 * datagram we can overwrite the value and ignore it.

239 */

240 if (NAPI_GRO_CB(skb)->is_atomic)

241 NAPI_GRO_CB(p)->flush_id = 0;

242 }

243

244 NAPI_GRO_CB(skb)->is_atomic = true;

245 NAPI_GRO_CB(skb)->flush |= flush;

246

247 skb_gro_postpull_rcsum(skb, iph, nlen);

248

249 pp = ops->callbacks.gro_receive(head, skb);

250

251 out_unlock:

252 rcu_read_unlock();

253

254 out:

255 NAPI_GRO_CB(skb)->flush |= flush;

256

257 return pp;

258 }

259

260 static struct sk_buff **sit_ip6ip6_gro_receive(struct sk_buff **head,

261 struct sk_buff *skb)

262 {

263 /* Common GRO receive for SIT and IP6IP6 */

264

265 if (NAPI_GRO_CB(skb)->encap_mark) {

266 NAPI_GRO_CB(skb)->flush = 1;

267 return NULL;

268 }

269

270 NAPI_GRO_CB(skb)->encap_mark = 1;

271

272 return ipv6_gro_receive(head, skb);

273 }

274

275 static struct sk_buff **ip4ip6_gro_receive(struct sk_buff **head,

276 struct sk_buff *skb)

277 {

278 /* Common GRO receive for SIT and IP6IP6 */

279

280 if (NAPI_GRO_CB(skb)->encap_mark) {

281 NAPI_GRO_CB(skb)->flush = 1;

282 return NULL;

283 }

284

285 NAPI_GRO_CB(skb)->encap_mark = 1;

286

287 return inet_gro_receive(head, skb);

288 }

289

290 static int ipv6_gro_complete(struct sk_buff *skb, int nhoff)

291 {

292 const struct net_offload *ops;

293 struct ipv6hdr *iph = (struct ipv6hdr *)(skb->data + nhoff);

294 int err = -ENOSYS;

295

296 if (skb->encapsulation)

297 skb_set_inner_network_header(skb, nhoff);

298

299 iph->payload_len = htons(skb->len - nhoff - sizeof(*iph));

300

301 rcu_read_lock();

302

303 nhoff += sizeof(*iph) + ipv6_exthdrs_len(iph, &ops);

304 if (WARN_ON(!ops || !ops->callbacks.gro_complete))

305 goto out_unlock;

306

307 err = ops->callbacks.gro_complete(skb, nhoff);

308

309 out_unlock:

310 rcu_read_unlock();

311

312 return err;

313 }

314

315 static int sit_gro_complete(struct sk_buff *skb, int nhoff)

316 {

317 skb->encapsulation = 1;

318 skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4;

319 return ipv6_gro_complete(skb, nhoff);

320 }

321

322 static int ip6ip6_gro_complete(struct sk_buff *skb, int nhoff)

323 {

324 skb->encapsulation = 1;

325 skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP6;

326 return ipv6_gro_complete(skb, nhoff);

327 }

328

329 static int ip4ip6_gro_complete(struct sk_buff *skb, int nhoff)

330 {

331 skb->encapsulation = 1;

332 skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP6;

333 return inet_gro_complete(skb, nhoff);

334 }

335

336 static struct packet_offload ipv6_packet_offload __read_mostly = {

337 .type = cpu_to_be16(ETH_P_IPV6),

338 .callbacks = {

339 .gso_segment = ipv6_gso_segment,

340 .gro_receive = ipv6_gro_receive,

341 .gro_complete = ipv6_gro_complete,

342 },

343 };

344

345 static const struct net_offload sit_offload = {

346 .callbacks = {

347 .gso_segment = ipv6_gso_segment,

348 .gro_receive = sit_ip6ip6_gro_receive,

349 .gro_complete = sit_gro_complete,

350 },

351 };

352

353 static const struct net_offload ip4ip6_offload = {

354 .callbacks = {

355 .gso_segment = inet_gso_segment,

356 .gro_receive = ip4ip6_gro_receive,

357 .gro_complete = ip4ip6_gro_complete,

358 },

359 };

360

361 static const struct net_offload ip6ip6_offload = {

362 .callbacks = {

363 .gso_segment = ipv6_gso_segment,

364 .gro_receive = sit_ip6ip6_gro_receive,

365 .gro_complete = ip6ip6_gro_complete,

366 },

367 };

368 static int __init ipv6_offload_init(void)

369 {

370

371 if (tcpv6_offload_init() < 0)

372 pr_crit("%s: Cannot add TCP protocol offload\n", __func__);

373 if (ipv6_exthdrs_offload_init() < 0)

374 pr_crit("%s: Cannot add EXTHDRS protocol offload\n", __func__);

375

376 dev_add_offload(&ipv6_packet_offload);

377

378 inet_add_offload(&sit_offload, IPPROTO_IPV6);

379 inet6_add_offload(&ip6ip6_offload, IPPROTO_IPV6);

380 inet6_add_offload(&ip4ip6_offload, IPPROTO_IPIP);

381

382 return 0;

383 }

384

385 fs_initcall(ipv6_offload_init);