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 struct sk_buff *validate_xmit_xfrm(struct sk_buff *skb, netdev_features_t features, bool *again) 101 { 102 int err; 103 unsigned long flags; 104 struct xfrm_state *x; 105 struct softnet_data *sd; 106 struct sk_buff *skb2, *nskb, *pskb = NULL; 107 netdev_features_t esp_features = features; 108 struct xfrm_offload *xo = xfrm_offload(skb); 109 struct net_device *dev = skb->dev; 110 struct sec_path *sp; 111 112 if (!xo || (xo->flags & XFRM_XMIT)) 113 return skb; 114 115 if (!(features & NETIF_F_HW_ESP)) 116 esp_features = features & ~(NETIF_F_SG | NETIF_F_CSUM_MASK); 117 118 sp = skb_sec_path(skb); 119 x = sp->xvec[sp->len - 1]; 120 if (xo->flags & XFRM_GRO || x->xso.dir == XFRM_DEV_OFFLOAD_IN) 121 return skb; 122 123 /* This skb was already validated on the upper/virtual dev */ 124 if ((x->xso.dev != dev) && (x->xso.real_dev == dev)) 125 return skb; 126 127 local_irq_save(flags); 128 sd = this_cpu_ptr(&softnet_data); 129 err = !skb_queue_empty(&sd->xfrm_backlog); 130 local_irq_restore(flags); 131 132 if (err) { 133 *again = true; 134 return skb; 135 } 136 137 if (skb_is_gso(skb) && unlikely(x->xso.dev != dev)) { 138 struct sk_buff *segs; 139 140 /* Packet got rerouted, fixup features and segment it. */ 141 esp_features = esp_features & ~(NETIF_F_HW_ESP | NETIF_F_GSO_ESP); 142 143 segs = skb_gso_segment(skb, esp_features); 144 if (IS_ERR(segs)) { 145 kfree_skb(skb); 146 dev_core_stats_tx_dropped_inc(dev); 147 return NULL; 148 } else { 149 consume_skb(skb); 150 skb = segs; 151 } 152 } 153 154 if (!skb->next) { 155 esp_features |= skb->dev->gso_partial_features; 156 xfrm_outer_mode_prep(x, skb); 157 158 xo->flags |= XFRM_DEV_RESUME; 159 160 err = x->type_offload->xmit(x, skb, esp_features); 161 if (err) { 162 if (err == -EINPROGRESS) 163 return NULL; 164 165 XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR); 166 kfree_skb(skb); 167 return NULL; 168 } 169 170 skb_push(skb, skb->data - skb_mac_header(skb)); 171 172 return skb; 173 } 174 175 skb_list_walk_safe(skb, skb2, nskb) { 176 esp_features |= skb->dev->gso_partial_features; 177 skb_mark_not_on_list(skb2); 178 179 xo = xfrm_offload(skb2); 180 xo->flags |= XFRM_DEV_RESUME; 181 182 xfrm_outer_mode_prep(x, skb2); 183 184 err = x->type_offload->xmit(x, skb2, esp_features); 185 if (!err) { 186 skb2->next = nskb; 187 } else if (err != -EINPROGRESS) { 188 XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR); 189 skb2->next = nskb; 190 kfree_skb_list(skb2); 191 return NULL; 192 } else { 193 if (skb == skb2) 194 skb = nskb; 195 else 196 pskb->next = nskb; 197 198 continue; 199 } 200 201 skb_push(skb2, skb2->data - skb_mac_header(skb2)); 202 pskb = skb2; 203 } 204 205 return skb; 206 } 207 EXPORT_SYMBOL_GPL(validate_xmit_xfrm); 208 209 int xfrm_dev_state_add(struct net *net, struct xfrm_state *x, 210 struct xfrm_user_offload *xuo, 211 struct netlink_ext_ack *extack) 212 { 213 int err; 214 struct dst_entry *dst; 215 struct net_device *dev; 216 struct xfrm_dev_offload *xso = &x->xso; 217 xfrm_address_t *saddr; 218 xfrm_address_t *daddr; 219 220 if (!x->type_offload) { 221 NL_SET_ERR_MSG(extack, "Type doesn't support offload"); 222 return -EINVAL; 223 } 224 225 /* We don't yet support UDP encapsulation and TFC padding. */ 226 if (x->encap || x->tfcpad) { 227 NL_SET_ERR_MSG(extack, "Encapsulation and TFC padding can't be offloaded"); 228 return -EINVAL; 229 } 230 231 if (xuo->flags & ~(XFRM_OFFLOAD_IPV6 | XFRM_OFFLOAD_INBOUND)) { 232 NL_SET_ERR_MSG(extack, "Unrecognized flags in offload request"); 233 return -EINVAL; 234 } 235 236 dev = dev_get_by_index(net, xuo->ifindex); 237 if (!dev) { 238 if (!(xuo->flags & XFRM_OFFLOAD_INBOUND)) { 239 saddr = &x->props.saddr; 240 daddr = &x->id.daddr; 241 } else { 242 saddr = &x->id.daddr; 243 daddr = &x->props.saddr; 244 } 245 246 dst = __xfrm_dst_lookup(net, 0, 0, saddr, daddr, 247 x->props.family, 248 xfrm_smark_get(0, x)); 249 if (IS_ERR(dst)) 250 return 0; 251 252 dev = dst->dev; 253 254 dev_hold(dev); 255 dst_release(dst); 256 } 257 258 if (!dev->xfrmdev_ops || !dev->xfrmdev_ops->xdo_dev_state_add) { 259 xso->dev = NULL; 260 dev_put(dev); 261 return 0; 262 } 263 264 if (x->props.flags & XFRM_STATE_ESN && 265 !dev->xfrmdev_ops->xdo_dev_state_advance_esn) { 266 NL_SET_ERR_MSG(extack, "Device doesn't support offload with ESN"); 267 xso->dev = NULL; 268 dev_put(dev); 269 return -EINVAL; 270 } 271 272 xso->dev = dev; 273 netdev_tracker_alloc(dev, &xso->dev_tracker, GFP_ATOMIC); 274 xso->real_dev = dev; 275 276 if (xuo->flags & XFRM_OFFLOAD_INBOUND) 277 xso->dir = XFRM_DEV_OFFLOAD_IN; 278 else 279 xso->dir = XFRM_DEV_OFFLOAD_OUT; 280 281 err = dev->xfrmdev_ops->xdo_dev_state_add(x); 282 if (err) { 283 xso->dev = NULL; 284 xso->dir = 0; 285 xso->real_dev = NULL; 286 netdev_put(dev, &xso->dev_tracker); 287 288 if (err != -EOPNOTSUPP) { 289 NL_SET_ERR_MSG(extack, "Device failed to offload this state"); 290 return err; 291 } 292 } 293 294 return 0; 295 } 296 EXPORT_SYMBOL_GPL(xfrm_dev_state_add); 297 298 bool xfrm_dev_offload_ok(struct sk_buff *skb, struct xfrm_state *x) 299 { 300 int mtu; 301 struct dst_entry *dst = skb_dst(skb); 302 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 303 struct net_device *dev = x->xso.dev; 304 305 if (!x->type_offload || x->encap) 306 return false; 307 308 if ((!dev || (dev == xfrm_dst_path(dst)->dev)) && 309 (!xdst->child->xfrm)) { 310 mtu = xfrm_state_mtu(x, xdst->child_mtu_cached); 311 if (skb->len <= mtu) 312 goto ok; 313 314 if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu)) 315 goto ok; 316 } 317 318 return false; 319 320 ok: 321 if (dev && dev->xfrmdev_ops && dev->xfrmdev_ops->xdo_dev_offload_ok) 322 return x->xso.dev->xfrmdev_ops->xdo_dev_offload_ok(skb, x); 323 324 return true; 325 } 326 EXPORT_SYMBOL_GPL(xfrm_dev_offload_ok); 327 328 void xfrm_dev_resume(struct sk_buff *skb) 329 { 330 struct net_device *dev = skb->dev; 331 int ret = NETDEV_TX_BUSY; 332 struct netdev_queue *txq; 333 struct softnet_data *sd; 334 unsigned long flags; 335 336 rcu_read_lock(); 337 txq = netdev_core_pick_tx(dev, skb, NULL); 338 339 HARD_TX_LOCK(dev, txq, smp_processor_id()); 340 if (!netif_xmit_frozen_or_stopped(txq)) 341 skb = dev_hard_start_xmit(skb, dev, txq, &ret); 342 HARD_TX_UNLOCK(dev, txq); 343 344 if (!dev_xmit_complete(ret)) { 345 local_irq_save(flags); 346 sd = this_cpu_ptr(&softnet_data); 347 skb_queue_tail(&sd->xfrm_backlog, skb); 348 raise_softirq_irqoff(NET_TX_SOFTIRQ); 349 local_irq_restore(flags); 350 } 351 rcu_read_unlock(); 352 } 353 EXPORT_SYMBOL_GPL(xfrm_dev_resume); 354 355 void xfrm_dev_backlog(struct softnet_data *sd) 356 { 357 struct sk_buff_head *xfrm_backlog = &sd->xfrm_backlog; 358 struct sk_buff_head list; 359 struct sk_buff *skb; 360 361 if (skb_queue_empty(xfrm_backlog)) 362 return; 363 364 __skb_queue_head_init(&list); 365 366 spin_lock(&xfrm_backlog->lock); 367 skb_queue_splice_init(xfrm_backlog, &list); 368 spin_unlock(&xfrm_backlog->lock); 369 370 while (!skb_queue_empty(&list)) { 371 skb = __skb_dequeue(&list); 372 xfrm_dev_resume(skb); 373 } 374 375 } 376 #endif 377 378 static int xfrm_api_check(struct net_device *dev) 379 { 380 #ifdef CONFIG_XFRM_OFFLOAD 381 if ((dev->features & NETIF_F_HW_ESP_TX_CSUM) && 382 !(dev->features & NETIF_F_HW_ESP)) 383 return NOTIFY_BAD; 384 385 if ((dev->features & NETIF_F_HW_ESP) && 386 (!(dev->xfrmdev_ops && 387 dev->xfrmdev_ops->xdo_dev_state_add && 388 dev->xfrmdev_ops->xdo_dev_state_delete))) 389 return NOTIFY_BAD; 390 #else 391 if (dev->features & (NETIF_F_HW_ESP | NETIF_F_HW_ESP_TX_CSUM)) 392 return NOTIFY_BAD; 393 #endif 394 395 return NOTIFY_DONE; 396 } 397 398 static int xfrm_dev_down(struct net_device *dev) 399 { 400 if (dev->features & NETIF_F_HW_ESP) 401 xfrm_dev_state_flush(dev_net(dev), dev, true); 402 403 return NOTIFY_DONE; 404 } 405 406 static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr) 407 { 408 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 409 410 switch (event) { 411 case NETDEV_REGISTER: 412 return xfrm_api_check(dev); 413 414 case NETDEV_FEAT_CHANGE: 415 return xfrm_api_check(dev); 416 417 case NETDEV_DOWN: 418 case NETDEV_UNREGISTER: 419 return xfrm_dev_down(dev); 420 } 421 return NOTIFY_DONE; 422 } 423 424 static struct notifier_block xfrm_dev_notifier = { 425 .notifier_call = xfrm_dev_event, 426 }; 427 428 void __init xfrm_dev_init(void) 429 { 430 register_netdevice_notifier(&xfrm_dev_notifier); 431 } 432