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 pskb_pull(skb, skb->mac_len + hsize + x->props.header_len); 29 30 if (xo->flags & XFRM_GSO_SEGMENT) { 31 skb_reset_transport_header(skb); 32 skb->transport_header -= x->props.header_len; 33 } 34 } 35 36 static void __xfrm_mode_tunnel_prep(struct xfrm_state *x, struct sk_buff *skb, 37 unsigned int hsize) 38 39 { 40 struct xfrm_offload *xo = xfrm_offload(skb); 41 42 if (xo->flags & XFRM_GSO_SEGMENT) 43 skb->transport_header = skb->network_header + hsize; 44 45 skb_reset_mac_len(skb); 46 pskb_pull(skb, skb->mac_len + x->props.header_len); 47 } 48 49 /* Adjust pointers into the packet when IPsec is done at layer2 */ 50 static void xfrm_outer_mode_prep(struct xfrm_state *x, struct sk_buff *skb) 51 { 52 switch (x->outer_mode.encap) { 53 case XFRM_MODE_TUNNEL: 54 if (x->outer_mode.family == AF_INET) 55 return __xfrm_mode_tunnel_prep(x, skb, 56 sizeof(struct iphdr)); 57 if (x->outer_mode.family == AF_INET6) 58 return __xfrm_mode_tunnel_prep(x, skb, 59 sizeof(struct ipv6hdr)); 60 break; 61 case XFRM_MODE_TRANSPORT: 62 if (x->outer_mode.family == AF_INET) 63 return __xfrm_transport_prep(x, skb, 64 sizeof(struct iphdr)); 65 if (x->outer_mode.family == AF_INET6) 66 return __xfrm_transport_prep(x, skb, 67 sizeof(struct ipv6hdr)); 68 break; 69 case XFRM_MODE_ROUTEOPTIMIZATION: 70 case XFRM_MODE_IN_TRIGGER: 71 case XFRM_MODE_BEET: 72 break; 73 } 74 } 75 76 struct sk_buff *validate_xmit_xfrm(struct sk_buff *skb, netdev_features_t features, bool *again) 77 { 78 int err; 79 unsigned long flags; 80 struct xfrm_state *x; 81 struct sk_buff *skb2, *nskb; 82 struct softnet_data *sd; 83 netdev_features_t esp_features = features; 84 struct xfrm_offload *xo = xfrm_offload(skb); 85 struct sec_path *sp; 86 87 if (!xo) 88 return skb; 89 90 if (!(features & NETIF_F_HW_ESP)) 91 esp_features = features & ~(NETIF_F_SG | NETIF_F_CSUM_MASK); 92 93 sp = skb_sec_path(skb); 94 x = sp->xvec[sp->len - 1]; 95 if (xo->flags & XFRM_GRO || x->xso.flags & XFRM_OFFLOAD_INBOUND) 96 return skb; 97 98 local_irq_save(flags); 99 sd = this_cpu_ptr(&softnet_data); 100 err = !skb_queue_empty(&sd->xfrm_backlog); 101 local_irq_restore(flags); 102 103 if (err) { 104 *again = true; 105 return skb; 106 } 107 108 if (skb_is_gso(skb)) { 109 struct net_device *dev = skb->dev; 110 111 if (unlikely(x->xso.dev != dev)) { 112 struct sk_buff *segs; 113 114 /* Packet got rerouted, fixup features and segment it. */ 115 esp_features = esp_features & ~(NETIF_F_HW_ESP 116 | NETIF_F_GSO_ESP); 117 118 segs = skb_gso_segment(skb, esp_features); 119 if (IS_ERR(segs)) { 120 kfree_skb(skb); 121 atomic_long_inc(&dev->tx_dropped); 122 return NULL; 123 } else { 124 consume_skb(skb); 125 skb = segs; 126 } 127 } 128 } 129 130 if (!skb->next) { 131 esp_features |= skb->dev->gso_partial_features; 132 xfrm_outer_mode_prep(x, skb); 133 134 xo->flags |= XFRM_DEV_RESUME; 135 136 err = x->type_offload->xmit(x, skb, esp_features); 137 if (err) { 138 if (err == -EINPROGRESS) 139 return NULL; 140 141 XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR); 142 kfree_skb(skb); 143 return NULL; 144 } 145 146 skb_push(skb, skb->data - skb_mac_header(skb)); 147 148 return skb; 149 } 150 151 skb_list_walk_safe(skb, skb2, nskb) { 152 esp_features |= skb->dev->gso_partial_features; 153 skb_mark_not_on_list(skb2); 154 155 xo = xfrm_offload(skb2); 156 xo->flags |= XFRM_DEV_RESUME; 157 158 xfrm_outer_mode_prep(x, skb2); 159 160 err = x->type_offload->xmit(x, skb2, esp_features); 161 if (!err) { 162 skb2->next = nskb; 163 } else if (err != -EINPROGRESS) { 164 XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR); 165 skb2->next = nskb; 166 kfree_skb_list(skb2); 167 return NULL; 168 } else { 169 if (skb == skb2) 170 skb = nskb; 171 172 if (!skb) 173 return NULL; 174 175 continue; 176 } 177 178 skb_push(skb2, skb2->data - skb_mac_header(skb2)); 179 } 180 181 return skb; 182 } 183 EXPORT_SYMBOL_GPL(validate_xmit_xfrm); 184 185 int xfrm_dev_state_add(struct net *net, struct xfrm_state *x, 186 struct xfrm_user_offload *xuo) 187 { 188 int err; 189 struct dst_entry *dst; 190 struct net_device *dev; 191 struct xfrm_state_offload *xso = &x->xso; 192 xfrm_address_t *saddr; 193 xfrm_address_t *daddr; 194 195 if (!x->type_offload) 196 return -EINVAL; 197 198 /* We don't yet support UDP encapsulation and TFC padding. */ 199 if (x->encap || x->tfcpad) 200 return -EINVAL; 201 202 dev = dev_get_by_index(net, xuo->ifindex); 203 if (!dev) { 204 if (!(xuo->flags & XFRM_OFFLOAD_INBOUND)) { 205 saddr = &x->props.saddr; 206 daddr = &x->id.daddr; 207 } else { 208 saddr = &x->id.daddr; 209 daddr = &x->props.saddr; 210 } 211 212 dst = __xfrm_dst_lookup(net, 0, 0, saddr, daddr, 213 x->props.family, 214 xfrm_smark_get(0, x)); 215 if (IS_ERR(dst)) 216 return 0; 217 218 dev = dst->dev; 219 220 dev_hold(dev); 221 dst_release(dst); 222 } 223 224 if (!dev->xfrmdev_ops || !dev->xfrmdev_ops->xdo_dev_state_add) { 225 xso->dev = NULL; 226 dev_put(dev); 227 return 0; 228 } 229 230 if (x->props.flags & XFRM_STATE_ESN && 231 !dev->xfrmdev_ops->xdo_dev_state_advance_esn) { 232 xso->dev = NULL; 233 dev_put(dev); 234 return -EINVAL; 235 } 236 237 xso->dev = dev; 238 xso->num_exthdrs = 1; 239 xso->flags = xuo->flags; 240 241 err = dev->xfrmdev_ops->xdo_dev_state_add(x); 242 if (err) { 243 xso->num_exthdrs = 0; 244 xso->flags = 0; 245 xso->dev = NULL; 246 dev_put(dev); 247 248 if (err != -EOPNOTSUPP) 249 return err; 250 } 251 252 return 0; 253 } 254 EXPORT_SYMBOL_GPL(xfrm_dev_state_add); 255 256 bool xfrm_dev_offload_ok(struct sk_buff *skb, struct xfrm_state *x) 257 { 258 int mtu; 259 struct dst_entry *dst = skb_dst(skb); 260 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 261 struct net_device *dev = x->xso.dev; 262 263 if (!x->type_offload || x->encap) 264 return false; 265 266 if ((!dev || (dev == xfrm_dst_path(dst)->dev)) && 267 (!xdst->child->xfrm)) { 268 mtu = xfrm_state_mtu(x, xdst->child_mtu_cached); 269 if (skb->len <= mtu) 270 goto ok; 271 272 if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu)) 273 goto ok; 274 } 275 276 return false; 277 278 ok: 279 if (dev && dev->xfrmdev_ops && dev->xfrmdev_ops->xdo_dev_offload_ok) 280 return x->xso.dev->xfrmdev_ops->xdo_dev_offload_ok(skb, x); 281 282 return true; 283 } 284 EXPORT_SYMBOL_GPL(xfrm_dev_offload_ok); 285 286 void xfrm_dev_resume(struct sk_buff *skb) 287 { 288 struct net_device *dev = skb->dev; 289 int ret = NETDEV_TX_BUSY; 290 struct netdev_queue *txq; 291 struct softnet_data *sd; 292 unsigned long flags; 293 294 rcu_read_lock(); 295 txq = netdev_core_pick_tx(dev, skb, NULL); 296 297 HARD_TX_LOCK(dev, txq, smp_processor_id()); 298 if (!netif_xmit_frozen_or_stopped(txq)) 299 skb = dev_hard_start_xmit(skb, dev, txq, &ret); 300 HARD_TX_UNLOCK(dev, txq); 301 302 if (!dev_xmit_complete(ret)) { 303 local_irq_save(flags); 304 sd = this_cpu_ptr(&softnet_data); 305 skb_queue_tail(&sd->xfrm_backlog, skb); 306 raise_softirq_irqoff(NET_TX_SOFTIRQ); 307 local_irq_restore(flags); 308 } 309 rcu_read_unlock(); 310 } 311 EXPORT_SYMBOL_GPL(xfrm_dev_resume); 312 313 void xfrm_dev_backlog(struct softnet_data *sd) 314 { 315 struct sk_buff_head *xfrm_backlog = &sd->xfrm_backlog; 316 struct sk_buff_head list; 317 struct sk_buff *skb; 318 319 if (skb_queue_empty(xfrm_backlog)) 320 return; 321 322 __skb_queue_head_init(&list); 323 324 spin_lock(&xfrm_backlog->lock); 325 skb_queue_splice_init(xfrm_backlog, &list); 326 spin_unlock(&xfrm_backlog->lock); 327 328 while (!skb_queue_empty(&list)) { 329 skb = __skb_dequeue(&list); 330 xfrm_dev_resume(skb); 331 } 332 333 } 334 #endif 335 336 static int xfrm_api_check(struct net_device *dev) 337 { 338 #ifdef CONFIG_XFRM_OFFLOAD 339 if ((dev->features & NETIF_F_HW_ESP_TX_CSUM) && 340 !(dev->features & NETIF_F_HW_ESP)) 341 return NOTIFY_BAD; 342 343 if ((dev->features & NETIF_F_HW_ESP) && 344 (!(dev->xfrmdev_ops && 345 dev->xfrmdev_ops->xdo_dev_state_add && 346 dev->xfrmdev_ops->xdo_dev_state_delete))) 347 return NOTIFY_BAD; 348 #else 349 if (dev->features & (NETIF_F_HW_ESP | NETIF_F_HW_ESP_TX_CSUM)) 350 return NOTIFY_BAD; 351 #endif 352 353 return NOTIFY_DONE; 354 } 355 356 static int xfrm_dev_register(struct net_device *dev) 357 { 358 return xfrm_api_check(dev); 359 } 360 361 static int xfrm_dev_feat_change(struct net_device *dev) 362 { 363 return xfrm_api_check(dev); 364 } 365 366 static int xfrm_dev_down(struct net_device *dev) 367 { 368 if (dev->features & NETIF_F_HW_ESP) 369 xfrm_dev_state_flush(dev_net(dev), dev, true); 370 371 return NOTIFY_DONE; 372 } 373 374 static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr) 375 { 376 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 377 378 switch (event) { 379 case NETDEV_REGISTER: 380 return xfrm_dev_register(dev); 381 382 case NETDEV_FEAT_CHANGE: 383 return xfrm_dev_feat_change(dev); 384 385 case NETDEV_DOWN: 386 return xfrm_dev_down(dev); 387 } 388 return NOTIFY_DONE; 389 } 390 391 static struct notifier_block xfrm_dev_notifier = { 392 .notifier_call = xfrm_dev_event, 393 }; 394 395 void __init xfrm_dev_init(void) 396 { 397 register_netdevice_notifier(&xfrm_dev_notifier); 398 } 399