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