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