1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * IPV6 GSO/GRO offload support 4 * Linux INET6 implementation 5 */ 6 7 #include <linux/kernel.h> 8 #include <linux/socket.h> 9 #include <linux/netdevice.h> 10 #include <linux/skbuff.h> 11 #include <linux/printk.h> 12 13 #include <net/protocol.h> 14 #include <net/ipv6.h> 15 #include <net/inet_common.h> 16 #include <net/tcp.h> 17 #include <net/udp.h> 18 #include <net/gro.h> 19 #include <net/gso.h> 20 21 #include "ip6_offload.h" 22 #include "tcpv6_offload.c" 23 24 static int ipv6_gro_pull_exthdrs(struct sk_buff *skb, int off, int proto) 25 { 26 const struct net_offload *ops = NULL; 27 struct ipv6_opt_hdr *opth; 28 29 for (;;) { 30 int len; 31 32 ops = rcu_dereference(inet6_offloads[proto]); 33 34 if (unlikely(!ops)) 35 break; 36 37 if (!(ops->flags & INET6_PROTO_GSO_EXTHDR)) 38 break; 39 40 opth = skb_gro_header(skb, off + sizeof(*opth), off); 41 if (unlikely(!opth)) 42 break; 43 44 len = ipv6_optlen(opth); 45 46 opth = skb_gro_header(skb, off + len, off); 47 if (unlikely(!opth)) 48 break; 49 proto = opth->nexthdr; 50 51 off += len; 52 } 53 54 skb_gro_pull(skb, off - skb_gro_receive_network_offset(skb)); 55 return proto; 56 } 57 58 static int ipv6_gso_pull_exthdrs(struct sk_buff *skb, int proto) 59 { 60 const struct net_offload *ops = NULL; 61 62 for (;;) { 63 struct ipv6_opt_hdr *opth; 64 int len; 65 66 ops = rcu_dereference(inet6_offloads[proto]); 67 68 if (unlikely(!ops)) 69 break; 70 71 if (!(ops->flags & INET6_PROTO_GSO_EXTHDR)) 72 break; 73 74 if (unlikely(!pskb_may_pull(skb, 8))) 75 break; 76 77 opth = (void *)skb->data; 78 len = ipv6_optlen(opth); 79 80 if (unlikely(!pskb_may_pull(skb, len))) 81 break; 82 83 opth = (void *)skb->data; 84 proto = opth->nexthdr; 85 __skb_pull(skb, len); 86 } 87 88 return proto; 89 } 90 91 static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb, 92 netdev_features_t features) 93 { 94 struct sk_buff *segs = ERR_PTR(-EINVAL); 95 struct ipv6hdr *ipv6h; 96 const struct net_offload *ops; 97 int proto; 98 struct frag_hdr *fptr; 99 unsigned int payload_len; 100 u8 *prevhdr; 101 int offset = 0; 102 bool encap, udpfrag; 103 int nhoff; 104 bool gso_partial; 105 106 skb_reset_network_header(skb); 107 nhoff = skb_network_header(skb) - skb_mac_header(skb); 108 if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h)))) 109 goto out; 110 111 encap = SKB_GSO_CB(skb)->encap_level > 0; 112 if (encap) 113 features &= skb->dev->hw_enc_features; 114 SKB_GSO_CB(skb)->encap_level += sizeof(*ipv6h); 115 116 ipv6h = ipv6_hdr(skb); 117 __skb_pull(skb, sizeof(*ipv6h)); 118 segs = ERR_PTR(-EPROTONOSUPPORT); 119 120 proto = ipv6_gso_pull_exthdrs(skb, ipv6h->nexthdr); 121 122 if (skb->encapsulation && 123 skb_shinfo(skb)->gso_type & (SKB_GSO_IPXIP4 | SKB_GSO_IPXIP6)) 124 udpfrag = proto == IPPROTO_UDP && encap && 125 (skb_shinfo(skb)->gso_type & SKB_GSO_UDP); 126 else 127 udpfrag = proto == IPPROTO_UDP && !skb->encapsulation && 128 (skb_shinfo(skb)->gso_type & SKB_GSO_UDP); 129 130 ops = rcu_dereference(inet6_offloads[proto]); 131 if (likely(ops && ops->callbacks.gso_segment)) { 132 if (!skb_reset_transport_header_careful(skb)) 133 goto out; 134 135 segs = ops->callbacks.gso_segment(skb, features); 136 if (!segs) 137 skb->network_header = skb_mac_header(skb) + nhoff - skb->head; 138 } 139 140 if (IS_ERR_OR_NULL(segs)) 141 goto out; 142 143 gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL); 144 145 for (skb = segs; skb; skb = skb->next) { 146 ipv6h = (struct ipv6hdr *)(skb_mac_header(skb) + nhoff); 147 if (gso_partial && skb_is_gso(skb)) 148 payload_len = skb_shinfo(skb)->gso_size + 149 SKB_GSO_CB(skb)->data_offset + 150 skb->head - (unsigned char *)(ipv6h + 1); 151 else 152 payload_len = skb->len - nhoff - sizeof(*ipv6h); 153 ipv6h->payload_len = htons(payload_len); 154 skb->network_header = (u8 *)ipv6h - skb->head; 155 skb_reset_mac_len(skb); 156 157 if (udpfrag) { 158 int err = ip6_find_1stfragopt(skb, &prevhdr); 159 if (err < 0) { 160 kfree_skb_list(segs); 161 return ERR_PTR(err); 162 } 163 fptr = (struct frag_hdr *)((u8 *)ipv6h + err); 164 fptr->frag_off = htons(offset); 165 if (skb->next) 166 fptr->frag_off |= htons(IP6_MF); 167 offset += (ntohs(ipv6h->payload_len) - 168 sizeof(struct frag_hdr)); 169 } 170 if (encap) 171 skb_reset_inner_headers(skb); 172 } 173 174 out: 175 return segs; 176 } 177 178 /* Return the total length of all the extension hdrs, following the same 179 * logic in ipv6_gso_pull_exthdrs() when parsing ext-hdrs. 180 */ 181 static int ipv6_exthdrs_len(struct ipv6hdr *iph, 182 const struct net_offload **opps) 183 { 184 struct ipv6_opt_hdr *opth = (void *)iph; 185 int len = 0, proto, optlen = sizeof(*iph); 186 187 proto = iph->nexthdr; 188 for (;;) { 189 *opps = rcu_dereference(inet6_offloads[proto]); 190 if (unlikely(!(*opps))) 191 break; 192 if (!((*opps)->flags & INET6_PROTO_GSO_EXTHDR)) 193 break; 194 195 opth = (void *)opth + optlen; 196 optlen = ipv6_optlen(opth); 197 len += optlen; 198 proto = opth->nexthdr; 199 } 200 return len; 201 } 202 203 INDIRECT_CALLABLE_SCOPE struct sk_buff *ipv6_gro_receive(struct list_head *head, 204 struct sk_buff *skb) 205 { 206 const struct net_offload *ops; 207 struct sk_buff *pp = NULL; 208 struct sk_buff *p; 209 struct ipv6hdr *iph; 210 unsigned int nlen; 211 unsigned int hlen; 212 unsigned int off; 213 u16 flush = 1; 214 int proto; 215 216 off = skb_gro_offset(skb); 217 hlen = off + sizeof(*iph); 218 iph = skb_gro_header(skb, hlen, off); 219 if (unlikely(!iph)) 220 goto out; 221 222 NAPI_GRO_CB(skb)->network_offsets[NAPI_GRO_CB(skb)->encap_mark] = off; 223 224 flush += ntohs(iph->payload_len) != skb->len - hlen; 225 226 proto = iph->nexthdr; 227 ops = rcu_dereference(inet6_offloads[proto]); 228 if (!ops || !ops->callbacks.gro_receive) { 229 proto = ipv6_gro_pull_exthdrs(skb, hlen, proto); 230 231 ops = rcu_dereference(inet6_offloads[proto]); 232 if (!ops || !ops->callbacks.gro_receive) 233 goto out; 234 235 iph = skb_gro_network_header(skb); 236 } else { 237 skb_gro_pull(skb, sizeof(*iph)); 238 } 239 240 skb_set_transport_header(skb, skb_gro_offset(skb)); 241 242 NAPI_GRO_CB(skb)->proto = proto; 243 244 flush--; 245 nlen = skb_gro_offset(skb) - off; 246 247 list_for_each_entry(p, head, list) { 248 const struct ipv6hdr *iph2; 249 __be32 first_word; /* <Version:4><Traffic_Class:8><Flow_Label:20> */ 250 251 if (!NAPI_GRO_CB(p)->same_flow) 252 continue; 253 254 iph2 = (struct ipv6hdr *)(p->data + off); 255 first_word = *(__be32 *)iph ^ *(__be32 *)iph2; 256 257 /* All fields must match except length and Traffic Class. 258 * XXX skbs on the gro_list have all been parsed and pulled 259 * already so we don't need to compare nlen 260 * (nlen != (sizeof(*iph2) + ipv6_exthdrs_len(iph2, &ops))) 261 * memcmp() alone below is sufficient, right? 262 */ 263 if ((first_word & htonl(0xF00FFFFF)) || 264 !ipv6_addr_equal(&iph->saddr, &iph2->saddr) || 265 !ipv6_addr_equal(&iph->daddr, &iph2->daddr) || 266 iph->nexthdr != iph2->nexthdr) { 267 not_same_flow: 268 NAPI_GRO_CB(p)->same_flow = 0; 269 continue; 270 } 271 if (unlikely(nlen > sizeof(struct ipv6hdr))) { 272 if (memcmp(iph + 1, iph2 + 1, 273 nlen - sizeof(struct ipv6hdr))) 274 goto not_same_flow; 275 } 276 } 277 278 NAPI_GRO_CB(skb)->flush |= flush; 279 280 skb_gro_postpull_rcsum(skb, iph, nlen); 281 282 if (unlikely(gro_recursion_inc_test(skb))) { 283 flush = 1; 284 goto out; 285 } 286 287 if (likely(proto == IPPROTO_TCP)) 288 pp = tcp6_gro_receive(head, skb); 289 #if IS_BUILTIN(CONFIG_IPV6) 290 else if (likely(proto == IPPROTO_UDP)) 291 pp = udp6_gro_receive(head, skb); 292 #endif 293 else 294 pp = ops->callbacks.gro_receive(head, skb); 295 out: 296 skb_gro_flush_final(skb, pp, flush); 297 298 return pp; 299 } 300 301 static struct sk_buff *sit_ip6ip6_gro_receive(struct list_head *head, 302 struct sk_buff *skb) 303 { 304 /* Common GRO receive for SIT and IP6IP6 */ 305 306 if (NAPI_GRO_CB(skb)->encap_mark) { 307 NAPI_GRO_CB(skb)->flush = 1; 308 return NULL; 309 } 310 311 NAPI_GRO_CB(skb)->encap_mark = 1; 312 313 return ipv6_gro_receive(head, skb); 314 } 315 316 static struct sk_buff *ip4ip6_gro_receive(struct list_head *head, 317 struct sk_buff *skb) 318 { 319 /* Common GRO receive for SIT and IP6IP6 */ 320 321 if (NAPI_GRO_CB(skb)->encap_mark) { 322 NAPI_GRO_CB(skb)->flush = 1; 323 return NULL; 324 } 325 326 NAPI_GRO_CB(skb)->encap_mark = 1; 327 328 return inet_gro_receive(head, skb); 329 } 330 331 INDIRECT_CALLABLE_SCOPE int ipv6_gro_complete(struct sk_buff *skb, int nhoff) 332 { 333 const struct net_offload *ops; 334 struct ipv6hdr *iph; 335 int err = -ENOSYS; 336 337 if (skb->encapsulation) { 338 skb_set_inner_protocol(skb, cpu_to_be16(ETH_P_IPV6)); 339 skb_set_inner_network_header(skb, nhoff); 340 } 341 342 iph = (struct ipv6hdr *)(skb->data + nhoff); 343 ipv6_set_payload_len(iph, skb->len - nhoff - sizeof(*iph)); 344 345 nhoff += sizeof(*iph) + ipv6_exthdrs_len(iph, &ops); 346 347 if (likely(ops == &net_hotdata.tcpv6_offload)) 348 return tcp6_gro_complete(skb, nhoff); 349 #if IS_BUILTIN(CONFIG_IPV6) 350 if (ops == &net_hotdata.udpv6_offload) 351 return udp6_gro_complete(skb, nhoff); 352 #endif 353 354 if (WARN_ON(!ops || !ops->callbacks.gro_complete)) 355 goto out; 356 357 err = ops->callbacks.gro_complete(skb, nhoff); 358 359 out: 360 return err; 361 } 362 363 static int sit_gro_complete(struct sk_buff *skb, int nhoff) 364 { 365 skb->encapsulation = 1; 366 skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4; 367 return ipv6_gro_complete(skb, nhoff); 368 } 369 370 static int ip6ip6_gro_complete(struct sk_buff *skb, int nhoff) 371 { 372 skb->encapsulation = 1; 373 skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP6; 374 return ipv6_gro_complete(skb, nhoff); 375 } 376 377 static int ip4ip6_gro_complete(struct sk_buff *skb, int nhoff) 378 { 379 skb->encapsulation = 1; 380 skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP6; 381 return inet_gro_complete(skb, nhoff); 382 } 383 384 385 static struct sk_buff *sit_gso_segment(struct sk_buff *skb, 386 netdev_features_t features) 387 { 388 if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP4)) 389 return ERR_PTR(-EINVAL); 390 391 return ipv6_gso_segment(skb, features); 392 } 393 394 static struct sk_buff *ip4ip6_gso_segment(struct sk_buff *skb, 395 netdev_features_t features) 396 { 397 if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP6)) 398 return ERR_PTR(-EINVAL); 399 400 return inet_gso_segment(skb, features); 401 } 402 403 static struct sk_buff *ip6ip6_gso_segment(struct sk_buff *skb, 404 netdev_features_t features) 405 { 406 if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP6)) 407 return ERR_PTR(-EINVAL); 408 409 return ipv6_gso_segment(skb, features); 410 } 411 412 static const struct net_offload sit_offload = { 413 .callbacks = { 414 .gso_segment = sit_gso_segment, 415 .gro_receive = sit_ip6ip6_gro_receive, 416 .gro_complete = sit_gro_complete, 417 }, 418 }; 419 420 static const struct net_offload ip4ip6_offload = { 421 .callbacks = { 422 .gso_segment = ip4ip6_gso_segment, 423 .gro_receive = ip4ip6_gro_receive, 424 .gro_complete = ip4ip6_gro_complete, 425 }, 426 }; 427 428 static const struct net_offload ip6ip6_offload = { 429 .callbacks = { 430 .gso_segment = ip6ip6_gso_segment, 431 .gro_receive = sit_ip6ip6_gro_receive, 432 .gro_complete = ip6ip6_gro_complete, 433 }, 434 }; 435 static int __init ipv6_offload_init(void) 436 { 437 438 if (tcpv6_offload_init() < 0) 439 pr_crit("%s: Cannot add TCP protocol offload\n", __func__); 440 if (ipv6_exthdrs_offload_init() < 0) 441 pr_crit("%s: Cannot add EXTHDRS protocol offload\n", __func__); 442 443 net_hotdata.ipv6_packet_offload = (struct packet_offload) { 444 .type = cpu_to_be16(ETH_P_IPV6), 445 .callbacks = { 446 .gso_segment = ipv6_gso_segment, 447 .gro_receive = ipv6_gro_receive, 448 .gro_complete = ipv6_gro_complete, 449 }, 450 }; 451 dev_add_offload(&net_hotdata.ipv6_packet_offload); 452 453 inet_add_offload(&sit_offload, IPPROTO_IPV6); 454 inet6_add_offload(&ip6ip6_offload, IPPROTO_IPV6); 455 inet6_add_offload(&ip4ip6_offload, IPPROTO_IPIP); 456 457 return 0; 458 } 459 460 fs_initcall(ipv6_offload_init); 461