1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * xfrm_device.c - IPsec device offloading code. 4 * 5 * Copyright (c) 2015 secunet Security Networks AG 6 * 7 * Author: 8 * Steffen Klassert <steffen.klassert@secunet.com> 9 */ 10 11 #include <linux/errno.h> 12 #include <linux/module.h> 13 #include <linux/netdevice.h> 14 #include <linux/skbuff.h> 15 #include <linux/slab.h> 16 #include <linux/spinlock.h> 17 #include <net/dst.h> 18 #include <net/gso.h> 19 #include <net/xfrm.h> 20 #include <linux/notifier.h> 21 22 #ifdef CONFIG_XFRM_OFFLOAD 23 static void __xfrm_transport_prep(struct xfrm_state *x, struct sk_buff *skb, 24 unsigned int hsize) 25 { 26 struct xfrm_offload *xo = xfrm_offload(skb); 27 28 skb_reset_mac_len(skb); 29 if (xo->flags & XFRM_GSO_SEGMENT) 30 skb->transport_header -= x->props.header_len; 31 32 pskb_pull(skb, skb_transport_offset(skb) + x->props.header_len); 33 } 34 35 static void __xfrm_mode_tunnel_prep(struct xfrm_state *x, struct sk_buff *skb, 36 unsigned int hsize) 37 38 { 39 struct xfrm_offload *xo = xfrm_offload(skb); 40 41 if (xo->flags & XFRM_GSO_SEGMENT) 42 skb->transport_header = skb->network_header + hsize; 43 44 skb_reset_mac_len(skb); 45 pskb_pull(skb, 46 skb->mac_len + x->props.header_len - x->props.enc_hdr_len); 47 } 48 49 static void __xfrm_mode_beet_prep(struct xfrm_state *x, struct sk_buff *skb, 50 unsigned int hsize) 51 { 52 struct xfrm_offload *xo = xfrm_offload(skb); 53 int phlen = 0; 54 55 if (xo->flags & XFRM_GSO_SEGMENT) 56 skb->transport_header = skb->network_header + hsize; 57 58 skb_reset_mac_len(skb); 59 if (x->sel.family != AF_INET6) { 60 phlen = IPV4_BEET_PHMAXLEN; 61 if (x->outer_mode.family == AF_INET6) 62 phlen += sizeof(struct ipv6hdr) - sizeof(struct iphdr); 63 } 64 65 pskb_pull(skb, skb->mac_len + hsize + (x->props.header_len - phlen)); 66 } 67 68 /* Adjust pointers into the packet when IPsec is done at layer2 */ 69 static void xfrm_outer_mode_prep(struct xfrm_state *x, struct sk_buff *skb) 70 { 71 switch (x->outer_mode.encap) { 72 case XFRM_MODE_IPTFS: 73 case XFRM_MODE_TUNNEL: 74 if (x->outer_mode.family == AF_INET) 75 return __xfrm_mode_tunnel_prep(x, skb, 76 sizeof(struct iphdr)); 77 if (x->outer_mode.family == AF_INET6) 78 return __xfrm_mode_tunnel_prep(x, skb, 79 sizeof(struct ipv6hdr)); 80 break; 81 case XFRM_MODE_TRANSPORT: 82 if (x->outer_mode.family == AF_INET) 83 return __xfrm_transport_prep(x, skb, 84 sizeof(struct iphdr)); 85 if (x->outer_mode.family == AF_INET6) 86 return __xfrm_transport_prep(x, skb, 87 sizeof(struct ipv6hdr)); 88 break; 89 case XFRM_MODE_BEET: 90 if (x->outer_mode.family == AF_INET) 91 return __xfrm_mode_beet_prep(x, skb, 92 sizeof(struct iphdr)); 93 if (x->outer_mode.family == AF_INET6) 94 return __xfrm_mode_beet_prep(x, skb, 95 sizeof(struct ipv6hdr)); 96 break; 97 case XFRM_MODE_ROUTEOPTIMIZATION: 98 case XFRM_MODE_IN_TRIGGER: 99 break; 100 } 101 } 102 103 static inline bool xmit_xfrm_check_overflow(struct sk_buff *skb) 104 { 105 struct xfrm_offload *xo = xfrm_offload(skb); 106 __u32 seq = xo->seq.low; 107 108 seq += skb_shinfo(skb)->gso_segs; 109 if (unlikely(seq < xo->seq.low)) 110 return true; 111 112 return false; 113 } 114 115 struct sk_buff *validate_xmit_xfrm(struct sk_buff *skb, netdev_features_t features, bool *again) 116 { 117 int err; 118 unsigned long flags; 119 struct xfrm_state *x; 120 struct softnet_data *sd; 121 struct sk_buff *skb2, *nskb, *pskb = NULL; 122 netdev_features_t esp_features = features; 123 struct xfrm_offload *xo = xfrm_offload(skb); 124 struct net_device *dev = skb->dev; 125 struct sec_path *sp; 126 127 if (!xo || (xo->flags & XFRM_XMIT)) 128 return skb; 129 130 if (!(features & NETIF_F_HW_ESP)) 131 esp_features = features & ~(NETIF_F_SG | NETIF_F_CSUM_MASK); 132 133 sp = skb_sec_path(skb); 134 x = sp->xvec[sp->len - 1]; 135 if (xo->flags & XFRM_GRO || x->xso.dir == XFRM_DEV_OFFLOAD_IN) 136 return skb; 137 138 /* The packet was sent to HW IPsec packet offload engine, 139 * but to wrong device. Drop the packet, so it won't skip 140 * XFRM stack. 141 */ 142 if (x->xso.type == XFRM_DEV_OFFLOAD_PACKET && x->xso.dev != dev) { 143 kfree_skb(skb); 144 dev_core_stats_tx_dropped_inc(dev); 145 return NULL; 146 } 147 148 local_irq_save(flags); 149 sd = this_cpu_ptr(&softnet_data); 150 err = !skb_queue_empty(&sd->xfrm_backlog); 151 local_irq_restore(flags); 152 153 if (err) { 154 *again = true; 155 return skb; 156 } 157 158 if (skb_is_gso(skb) && (unlikely(x->xso.dev != dev) || 159 unlikely(xmit_xfrm_check_overflow(skb)))) { 160 struct sk_buff *segs; 161 162 /* Packet got rerouted, fixup features and segment it. */ 163 esp_features = esp_features & ~(NETIF_F_HW_ESP | NETIF_F_GSO_ESP); 164 165 segs = skb_gso_segment(skb, esp_features); 166 if (IS_ERR(segs)) { 167 kfree_skb(skb); 168 dev_core_stats_tx_dropped_inc(dev); 169 return NULL; 170 } else { 171 consume_skb(skb); 172 skb = segs; 173 } 174 } 175 176 if (!skb->next) { 177 esp_features |= skb->dev->gso_partial_features; 178 xfrm_outer_mode_prep(x, skb); 179 180 xo->flags |= XFRM_DEV_RESUME; 181 182 err = x->type_offload->xmit(x, skb, esp_features); 183 if (err) { 184 if (err == -EINPROGRESS) 185 return NULL; 186 187 XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR); 188 kfree_skb(skb); 189 return NULL; 190 } 191 192 skb_push(skb, skb->data - skb_mac_header(skb)); 193 194 return skb; 195 } 196 197 skb_list_walk_safe(skb, skb2, nskb) { 198 esp_features |= skb->dev->gso_partial_features; 199 skb_mark_not_on_list(skb2); 200 201 xo = xfrm_offload(skb2); 202 xo->flags |= XFRM_DEV_RESUME; 203 204 xfrm_outer_mode_prep(x, skb2); 205 206 err = x->type_offload->xmit(x, skb2, esp_features); 207 if (!err) { 208 skb2->next = nskb; 209 } else if (err != -EINPROGRESS) { 210 XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR); 211 skb2->next = nskb; 212 kfree_skb_list(skb2); 213 return NULL; 214 } else { 215 if (skb == skb2) 216 skb = nskb; 217 else 218 pskb->next = nskb; 219 220 continue; 221 } 222 223 skb_push(skb2, skb2->data - skb_mac_header(skb2)); 224 pskb = skb2; 225 } 226 227 return skb; 228 } 229 EXPORT_SYMBOL_GPL(validate_xmit_xfrm); 230 231 int xfrm_dev_state_add(struct net *net, struct xfrm_state *x, 232 struct xfrm_user_offload *xuo, 233 struct netlink_ext_ack *extack) 234 { 235 int err; 236 struct dst_entry *dst; 237 struct net_device *dev; 238 struct xfrm_dev_offload *xso = &x->xso; 239 xfrm_address_t *saddr; 240 xfrm_address_t *daddr; 241 bool is_packet_offload; 242 243 if (xuo->flags & 244 ~(XFRM_OFFLOAD_IPV6 | XFRM_OFFLOAD_INBOUND | XFRM_OFFLOAD_PACKET)) { 245 NL_SET_ERR_MSG(extack, "Unrecognized flags in offload request"); 246 return -EINVAL; 247 } 248 249 if ((xuo->flags & XFRM_OFFLOAD_INBOUND && x->dir == XFRM_SA_DIR_OUT) || 250 (!(xuo->flags & XFRM_OFFLOAD_INBOUND) && x->dir == XFRM_SA_DIR_IN)) { 251 NL_SET_ERR_MSG(extack, "Mismatched SA and offload direction"); 252 return -EINVAL; 253 } 254 255 if (xuo->flags & XFRM_OFFLOAD_INBOUND && x->if_id) { 256 NL_SET_ERR_MSG(extack, "XFRM if_id is not supported in RX path"); 257 return -EINVAL; 258 } 259 260 is_packet_offload = xuo->flags & XFRM_OFFLOAD_PACKET; 261 262 /* We don't yet support TFC padding. */ 263 if (x->tfcpad) { 264 NL_SET_ERR_MSG(extack, "TFC padding can't be offloaded"); 265 return -EINVAL; 266 } 267 268 dev = dev_get_by_index(net, xuo->ifindex); 269 if (!dev) { 270 struct xfrm_dst_lookup_params params; 271 272 if (!(xuo->flags & XFRM_OFFLOAD_INBOUND)) { 273 saddr = &x->props.saddr; 274 daddr = &x->id.daddr; 275 } else { 276 saddr = &x->id.daddr; 277 daddr = &x->props.saddr; 278 } 279 280 memset(¶ms, 0, sizeof(params)); 281 params.net = net; 282 params.saddr = saddr; 283 params.daddr = daddr; 284 params.mark = xfrm_smark_get(0, x); 285 dst = __xfrm_dst_lookup(x->props.family, ¶ms); 286 if (IS_ERR(dst)) 287 return (is_packet_offload) ? -EINVAL : 0; 288 289 dev = dst->dev; 290 291 dev_hold(dev); 292 dst_release(dst); 293 } 294 295 if (!dev->xfrmdev_ops || !dev->xfrmdev_ops->xdo_dev_state_add) { 296 xso->dev = NULL; 297 dev_put(dev); 298 return (is_packet_offload) ? -EINVAL : 0; 299 } 300 301 if (!is_packet_offload && x->props.flags & XFRM_STATE_ESN && 302 !dev->xfrmdev_ops->xdo_dev_state_advance_esn) { 303 NL_SET_ERR_MSG(extack, "Device doesn't support offload with ESN"); 304 xso->dev = NULL; 305 dev_put(dev); 306 return -EINVAL; 307 } 308 309 if (!x->type_offload) { 310 NL_SET_ERR_MSG(extack, "Type doesn't support offload"); 311 dev_put(dev); 312 return -EINVAL; 313 } 314 315 xso->dev = dev; 316 netdev_tracker_alloc(dev, &xso->dev_tracker, GFP_ATOMIC); 317 318 if (xuo->flags & XFRM_OFFLOAD_INBOUND) 319 xso->dir = XFRM_DEV_OFFLOAD_IN; 320 else 321 xso->dir = XFRM_DEV_OFFLOAD_OUT; 322 323 if (is_packet_offload) 324 xso->type = XFRM_DEV_OFFLOAD_PACKET; 325 else 326 xso->type = XFRM_DEV_OFFLOAD_CRYPTO; 327 328 err = dev->xfrmdev_ops->xdo_dev_state_add(dev, x, extack); 329 if (err) { 330 xso->dev = NULL; 331 xso->dir = 0; 332 netdev_put(dev, &xso->dev_tracker); 333 xso->type = XFRM_DEV_OFFLOAD_UNSPECIFIED; 334 335 xfrm_unset_type_offload(x); 336 /* User explicitly requested packet offload mode and configured 337 * policy in addition to the XFRM state. So be civil to users, 338 * and return an error instead of taking fallback path. 339 */ 340 if ((err != -EOPNOTSUPP && !is_packet_offload) || is_packet_offload) { 341 NL_SET_ERR_MSG_WEAK(extack, "Device failed to offload this state"); 342 return err; 343 } 344 } 345 346 return 0; 347 } 348 EXPORT_SYMBOL_GPL(xfrm_dev_state_add); 349 350 int xfrm_dev_policy_add(struct net *net, struct xfrm_policy *xp, 351 struct xfrm_user_offload *xuo, u8 dir, 352 struct netlink_ext_ack *extack) 353 { 354 struct xfrm_dev_offload *xdo = &xp->xdo; 355 struct net_device *dev; 356 int err; 357 358 if (!xuo->flags || xuo->flags & ~XFRM_OFFLOAD_PACKET) { 359 /* We support only packet offload mode and it means 360 * that user must set XFRM_OFFLOAD_PACKET bit. 361 */ 362 NL_SET_ERR_MSG(extack, "Unrecognized flags in offload request"); 363 return -EINVAL; 364 } 365 366 dev = dev_get_by_index(net, xuo->ifindex); 367 if (!dev) 368 return -EINVAL; 369 370 if (!dev->xfrmdev_ops || !dev->xfrmdev_ops->xdo_dev_policy_add) { 371 xdo->dev = NULL; 372 dev_put(dev); 373 NL_SET_ERR_MSG(extack, "Policy offload is not supported"); 374 return -EINVAL; 375 } 376 377 xdo->dev = dev; 378 netdev_tracker_alloc(dev, &xdo->dev_tracker, GFP_ATOMIC); 379 xdo->type = XFRM_DEV_OFFLOAD_PACKET; 380 switch (dir) { 381 case XFRM_POLICY_IN: 382 xdo->dir = XFRM_DEV_OFFLOAD_IN; 383 break; 384 case XFRM_POLICY_OUT: 385 xdo->dir = XFRM_DEV_OFFLOAD_OUT; 386 break; 387 case XFRM_POLICY_FWD: 388 xdo->dir = XFRM_DEV_OFFLOAD_FWD; 389 break; 390 default: 391 xdo->dev = NULL; 392 netdev_put(dev, &xdo->dev_tracker); 393 NL_SET_ERR_MSG(extack, "Unrecognized offload direction"); 394 return -EINVAL; 395 } 396 397 err = dev->xfrmdev_ops->xdo_dev_policy_add(xp, extack); 398 if (err) { 399 xdo->dev = NULL; 400 xdo->type = XFRM_DEV_OFFLOAD_UNSPECIFIED; 401 xdo->dir = 0; 402 netdev_put(dev, &xdo->dev_tracker); 403 NL_SET_ERR_MSG_WEAK(extack, "Device failed to offload this policy"); 404 return err; 405 } 406 407 return 0; 408 } 409 EXPORT_SYMBOL_GPL(xfrm_dev_policy_add); 410 411 bool xfrm_dev_offload_ok(struct sk_buff *skb, struct xfrm_state *x) 412 { 413 int mtu; 414 struct dst_entry *dst = skb_dst(skb); 415 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 416 struct net_device *dev = x->xso.dev; 417 bool check_tunnel_size; 418 419 if (!x->type_offload || 420 (x->xso.type == XFRM_DEV_OFFLOAD_UNSPECIFIED && x->encap)) 421 return false; 422 423 if ((!dev || dev == xfrm_dst_path(dst)->dev) && 424 !xdst->child->xfrm) { 425 mtu = xfrm_state_mtu(x, xdst->child_mtu_cached); 426 if (skb->len <= mtu) 427 goto ok; 428 429 if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu)) 430 goto ok; 431 } 432 433 return false; 434 435 ok: 436 if (!dev) 437 return true; 438 439 check_tunnel_size = x->xso.type == XFRM_DEV_OFFLOAD_PACKET && 440 x->props.mode == XFRM_MODE_TUNNEL; 441 switch (x->props.family) { 442 case AF_INET: 443 /* Check for IPv4 options */ 444 if (ip_hdr(skb)->ihl != 5) 445 return false; 446 if (check_tunnel_size && xfrm4_tunnel_check_size(skb)) 447 return false; 448 break; 449 case AF_INET6: 450 /* Check for IPv6 extensions */ 451 if (ipv6_ext_hdr(ipv6_hdr(skb)->nexthdr)) 452 return false; 453 if (check_tunnel_size && xfrm6_tunnel_check_size(skb)) 454 return false; 455 break; 456 default: 457 break; 458 } 459 460 if (dev->xfrmdev_ops->xdo_dev_offload_ok) 461 return dev->xfrmdev_ops->xdo_dev_offload_ok(skb, x); 462 463 return true; 464 } 465 EXPORT_SYMBOL_GPL(xfrm_dev_offload_ok); 466 467 void xfrm_dev_resume(struct sk_buff *skb) 468 { 469 struct net_device *dev = skb->dev; 470 int ret = NETDEV_TX_BUSY; 471 struct netdev_queue *txq; 472 struct softnet_data *sd; 473 unsigned long flags; 474 475 rcu_read_lock(); 476 txq = netdev_core_pick_tx(dev, skb, NULL); 477 478 HARD_TX_LOCK(dev, txq, smp_processor_id()); 479 if (!netif_xmit_frozen_or_stopped(txq)) 480 skb = dev_hard_start_xmit(skb, dev, txq, &ret); 481 HARD_TX_UNLOCK(dev, txq); 482 483 if (!dev_xmit_complete(ret)) { 484 local_irq_save(flags); 485 sd = this_cpu_ptr(&softnet_data); 486 skb_queue_tail(&sd->xfrm_backlog, skb); 487 raise_softirq_irqoff(NET_TX_SOFTIRQ); 488 local_irq_restore(flags); 489 } 490 rcu_read_unlock(); 491 } 492 EXPORT_SYMBOL_GPL(xfrm_dev_resume); 493 494 void xfrm_dev_backlog(struct softnet_data *sd) 495 { 496 struct sk_buff_head *xfrm_backlog = &sd->xfrm_backlog; 497 struct sk_buff_head list; 498 struct sk_buff *skb; 499 500 if (skb_queue_empty(xfrm_backlog)) 501 return; 502 503 __skb_queue_head_init(&list); 504 505 spin_lock(&xfrm_backlog->lock); 506 skb_queue_splice_init(xfrm_backlog, &list); 507 spin_unlock(&xfrm_backlog->lock); 508 509 while (!skb_queue_empty(&list)) { 510 skb = __skb_dequeue(&list); 511 xfrm_dev_resume(skb); 512 } 513 514 } 515 #endif 516 517 static int xfrm_api_check(struct net_device *dev) 518 { 519 #ifdef CONFIG_XFRM_OFFLOAD 520 if ((dev->features & NETIF_F_HW_ESP_TX_CSUM) && 521 !(dev->features & NETIF_F_HW_ESP)) 522 return NOTIFY_BAD; 523 524 if ((dev->features & NETIF_F_HW_ESP) && 525 (!(dev->xfrmdev_ops && 526 dev->xfrmdev_ops->xdo_dev_state_add && 527 dev->xfrmdev_ops->xdo_dev_state_delete))) 528 return NOTIFY_BAD; 529 #else 530 if (dev->features & (NETIF_F_HW_ESP | NETIF_F_HW_ESP_TX_CSUM)) 531 return NOTIFY_BAD; 532 #endif 533 534 return NOTIFY_DONE; 535 } 536 537 static int xfrm_dev_down(struct net_device *dev) 538 { 539 if (dev->features & NETIF_F_HW_ESP) { 540 xfrm_dev_state_flush(dev_net(dev), dev, true); 541 xfrm_dev_policy_flush(dev_net(dev), dev, true); 542 } 543 544 return NOTIFY_DONE; 545 } 546 547 static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr) 548 { 549 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 550 551 switch (event) { 552 case NETDEV_REGISTER: 553 return xfrm_api_check(dev); 554 555 case NETDEV_FEAT_CHANGE: 556 return xfrm_api_check(dev); 557 558 case NETDEV_DOWN: 559 case NETDEV_UNREGISTER: 560 return xfrm_dev_down(dev); 561 } 562 return NOTIFY_DONE; 563 } 564 565 static struct notifier_block xfrm_dev_notifier = { 566 .notifier_call = xfrm_dev_event, 567 }; 568 569 void __init xfrm_dev_init(void) 570 { 571 register_netdevice_notifier(&xfrm_dev_notifier); 572 } 573