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 is_packet_offload = xuo->flags & XFRM_OFFLOAD_PACKET; 257 258 /* We don't yet support UDP encapsulation and TFC padding. */ 259 if ((!is_packet_offload && x->encap) || x->tfcpad) { 260 NL_SET_ERR_MSG(extack, "Encapsulation and TFC padding can't be offloaded"); 261 return -EINVAL; 262 } 263 264 dev = dev_get_by_index(net, xuo->ifindex); 265 if (!dev) { 266 if (!(xuo->flags & XFRM_OFFLOAD_INBOUND)) { 267 saddr = &x->props.saddr; 268 daddr = &x->id.daddr; 269 } else { 270 saddr = &x->id.daddr; 271 daddr = &x->props.saddr; 272 } 273 274 dst = __xfrm_dst_lookup(net, 0, 0, saddr, daddr, 275 x->props.family, 276 xfrm_smark_get(0, x)); 277 if (IS_ERR(dst)) 278 return (is_packet_offload) ? -EINVAL : 0; 279 280 dev = dst->dev; 281 282 dev_hold(dev); 283 dst_release(dst); 284 } 285 286 if (!dev->xfrmdev_ops || !dev->xfrmdev_ops->xdo_dev_state_add) { 287 xso->dev = NULL; 288 dev_put(dev); 289 return (is_packet_offload) ? -EINVAL : 0; 290 } 291 292 if (!is_packet_offload && x->props.flags & XFRM_STATE_ESN && 293 !dev->xfrmdev_ops->xdo_dev_state_advance_esn) { 294 NL_SET_ERR_MSG(extack, "Device doesn't support offload with ESN"); 295 xso->dev = NULL; 296 dev_put(dev); 297 return -EINVAL; 298 } 299 300 xso->dev = dev; 301 netdev_tracker_alloc(dev, &xso->dev_tracker, GFP_ATOMIC); 302 xso->real_dev = dev; 303 304 if (xuo->flags & XFRM_OFFLOAD_INBOUND) 305 xso->dir = XFRM_DEV_OFFLOAD_IN; 306 else 307 xso->dir = XFRM_DEV_OFFLOAD_OUT; 308 309 if (is_packet_offload) 310 xso->type = XFRM_DEV_OFFLOAD_PACKET; 311 else 312 xso->type = XFRM_DEV_OFFLOAD_CRYPTO; 313 314 err = dev->xfrmdev_ops->xdo_dev_state_add(x, extack); 315 if (err) { 316 xso->dev = NULL; 317 xso->dir = 0; 318 xso->real_dev = NULL; 319 netdev_put(dev, &xso->dev_tracker); 320 xso->type = XFRM_DEV_OFFLOAD_UNSPECIFIED; 321 322 /* User explicitly requested packet offload mode and configured 323 * policy in addition to the XFRM state. So be civil to users, 324 * and return an error instead of taking fallback path. 325 * 326 * This WARN_ON() can be seen as a documentation for driver 327 * authors to do not return -EOPNOTSUPP in packet offload mode. 328 */ 329 WARN_ON(err == -EOPNOTSUPP && is_packet_offload); 330 if (err != -EOPNOTSUPP || is_packet_offload) { 331 NL_SET_ERR_MSG_WEAK(extack, "Device failed to offload this state"); 332 return err; 333 } 334 } 335 336 return 0; 337 } 338 EXPORT_SYMBOL_GPL(xfrm_dev_state_add); 339 340 int xfrm_dev_policy_add(struct net *net, struct xfrm_policy *xp, 341 struct xfrm_user_offload *xuo, u8 dir, 342 struct netlink_ext_ack *extack) 343 { 344 struct xfrm_dev_offload *xdo = &xp->xdo; 345 struct net_device *dev; 346 int err; 347 348 if (!xuo->flags || xuo->flags & ~XFRM_OFFLOAD_PACKET) { 349 /* We support only packet offload mode and it means 350 * that user must set XFRM_OFFLOAD_PACKET bit. 351 */ 352 NL_SET_ERR_MSG(extack, "Unrecognized flags in offload request"); 353 return -EINVAL; 354 } 355 356 dev = dev_get_by_index(net, xuo->ifindex); 357 if (!dev) 358 return -EINVAL; 359 360 if (!dev->xfrmdev_ops || !dev->xfrmdev_ops->xdo_dev_policy_add) { 361 xdo->dev = NULL; 362 dev_put(dev); 363 NL_SET_ERR_MSG(extack, "Policy offload is not supported"); 364 return -EINVAL; 365 } 366 367 xdo->dev = dev; 368 netdev_tracker_alloc(dev, &xdo->dev_tracker, GFP_ATOMIC); 369 xdo->real_dev = dev; 370 xdo->type = XFRM_DEV_OFFLOAD_PACKET; 371 switch (dir) { 372 case XFRM_POLICY_IN: 373 xdo->dir = XFRM_DEV_OFFLOAD_IN; 374 break; 375 case XFRM_POLICY_OUT: 376 xdo->dir = XFRM_DEV_OFFLOAD_OUT; 377 break; 378 case XFRM_POLICY_FWD: 379 xdo->dir = XFRM_DEV_OFFLOAD_FWD; 380 break; 381 default: 382 xdo->dev = NULL; 383 netdev_put(dev, &xdo->dev_tracker); 384 NL_SET_ERR_MSG(extack, "Unrecognized offload direction"); 385 return -EINVAL; 386 } 387 388 err = dev->xfrmdev_ops->xdo_dev_policy_add(xp, extack); 389 if (err) { 390 xdo->dev = NULL; 391 xdo->real_dev = NULL; 392 xdo->type = XFRM_DEV_OFFLOAD_UNSPECIFIED; 393 xdo->dir = 0; 394 netdev_put(dev, &xdo->dev_tracker); 395 NL_SET_ERR_MSG_WEAK(extack, "Device failed to offload this policy"); 396 return err; 397 } 398 399 return 0; 400 } 401 EXPORT_SYMBOL_GPL(xfrm_dev_policy_add); 402 403 bool xfrm_dev_offload_ok(struct sk_buff *skb, struct xfrm_state *x) 404 { 405 int mtu; 406 struct dst_entry *dst = skb_dst(skb); 407 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 408 struct net_device *dev = x->xso.dev; 409 410 if (!x->type_offload || x->encap) 411 return false; 412 413 if (x->xso.type == XFRM_DEV_OFFLOAD_PACKET || 414 ((!dev || (dev == xfrm_dst_path(dst)->dev)) && 415 !xdst->child->xfrm)) { 416 mtu = xfrm_state_mtu(x, xdst->child_mtu_cached); 417 if (skb->len <= mtu) 418 goto ok; 419 420 if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu)) 421 goto ok; 422 } 423 424 return false; 425 426 ok: 427 if (dev && dev->xfrmdev_ops && dev->xfrmdev_ops->xdo_dev_offload_ok) 428 return x->xso.dev->xfrmdev_ops->xdo_dev_offload_ok(skb, x); 429 430 return true; 431 } 432 EXPORT_SYMBOL_GPL(xfrm_dev_offload_ok); 433 434 void xfrm_dev_resume(struct sk_buff *skb) 435 { 436 struct net_device *dev = skb->dev; 437 int ret = NETDEV_TX_BUSY; 438 struct netdev_queue *txq; 439 struct softnet_data *sd; 440 unsigned long flags; 441 442 rcu_read_lock(); 443 txq = netdev_core_pick_tx(dev, skb, NULL); 444 445 HARD_TX_LOCK(dev, txq, smp_processor_id()); 446 if (!netif_xmit_frozen_or_stopped(txq)) 447 skb = dev_hard_start_xmit(skb, dev, txq, &ret); 448 HARD_TX_UNLOCK(dev, txq); 449 450 if (!dev_xmit_complete(ret)) { 451 local_irq_save(flags); 452 sd = this_cpu_ptr(&softnet_data); 453 skb_queue_tail(&sd->xfrm_backlog, skb); 454 raise_softirq_irqoff(NET_TX_SOFTIRQ); 455 local_irq_restore(flags); 456 } 457 rcu_read_unlock(); 458 } 459 EXPORT_SYMBOL_GPL(xfrm_dev_resume); 460 461 void xfrm_dev_backlog(struct softnet_data *sd) 462 { 463 struct sk_buff_head *xfrm_backlog = &sd->xfrm_backlog; 464 struct sk_buff_head list; 465 struct sk_buff *skb; 466 467 if (skb_queue_empty(xfrm_backlog)) 468 return; 469 470 __skb_queue_head_init(&list); 471 472 spin_lock(&xfrm_backlog->lock); 473 skb_queue_splice_init(xfrm_backlog, &list); 474 spin_unlock(&xfrm_backlog->lock); 475 476 while (!skb_queue_empty(&list)) { 477 skb = __skb_dequeue(&list); 478 xfrm_dev_resume(skb); 479 } 480 481 } 482 #endif 483 484 static int xfrm_api_check(struct net_device *dev) 485 { 486 #ifdef CONFIG_XFRM_OFFLOAD 487 if ((dev->features & NETIF_F_HW_ESP_TX_CSUM) && 488 !(dev->features & NETIF_F_HW_ESP)) 489 return NOTIFY_BAD; 490 491 if ((dev->features & NETIF_F_HW_ESP) && 492 (!(dev->xfrmdev_ops && 493 dev->xfrmdev_ops->xdo_dev_state_add && 494 dev->xfrmdev_ops->xdo_dev_state_delete))) 495 return NOTIFY_BAD; 496 #else 497 if (dev->features & (NETIF_F_HW_ESP | NETIF_F_HW_ESP_TX_CSUM)) 498 return NOTIFY_BAD; 499 #endif 500 501 return NOTIFY_DONE; 502 } 503 504 static int xfrm_dev_down(struct net_device *dev) 505 { 506 if (dev->features & NETIF_F_HW_ESP) { 507 xfrm_dev_state_flush(dev_net(dev), dev, true); 508 xfrm_dev_policy_flush(dev_net(dev), dev, true); 509 } 510 511 return NOTIFY_DONE; 512 } 513 514 static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr) 515 { 516 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 517 518 switch (event) { 519 case NETDEV_REGISTER: 520 return xfrm_api_check(dev); 521 522 case NETDEV_FEAT_CHANGE: 523 return xfrm_api_check(dev); 524 525 case NETDEV_DOWN: 526 case NETDEV_UNREGISTER: 527 return xfrm_dev_down(dev); 528 } 529 return NOTIFY_DONE; 530 } 531 532 static struct notifier_block xfrm_dev_notifier = { 533 .notifier_call = xfrm_dev_event, 534 }; 535 536 void __init xfrm_dev_init(void) 537 { 538 register_netdevice_notifier(&xfrm_dev_notifier); 539 } 540