1 /* 2 * xfrm_device.c - IPsec device offloading code. 3 * 4 * Copyright (c) 2015 secunet Security Networks AG 5 * 6 * Author: 7 * Steffen Klassert <steffen.klassert@secunet.com> 8 * 9 * This program is free software; you can redistribute it and/or 10 * modify it under the terms of the GNU General Public License 11 * as published by the Free Software Foundation; either version 12 * 2 of the License, or (at your option) any later version. 13 */ 14 15 #include <linux/errno.h> 16 #include <linux/module.h> 17 #include <linux/netdevice.h> 18 #include <linux/skbuff.h> 19 #include <linux/slab.h> 20 #include <linux/spinlock.h> 21 #include <net/dst.h> 22 #include <net/xfrm.h> 23 #include <linux/notifier.h> 24 25 #ifdef CONFIG_XFRM_OFFLOAD 26 struct sk_buff *validate_xmit_xfrm(struct sk_buff *skb, netdev_features_t features, bool *again) 27 { 28 int err; 29 unsigned long flags; 30 struct xfrm_state *x; 31 struct sk_buff *skb2; 32 struct softnet_data *sd; 33 netdev_features_t esp_features = features; 34 struct xfrm_offload *xo = xfrm_offload(skb); 35 36 if (!xo) 37 return skb; 38 39 if (!(features & NETIF_F_HW_ESP)) 40 esp_features = features & ~(NETIF_F_SG | NETIF_F_CSUM_MASK); 41 42 x = skb->sp->xvec[skb->sp->len - 1]; 43 if (xo->flags & XFRM_GRO || x->xso.flags & XFRM_OFFLOAD_INBOUND) 44 return skb; 45 46 local_irq_save(flags); 47 sd = this_cpu_ptr(&softnet_data); 48 err = !skb_queue_empty(&sd->xfrm_backlog); 49 local_irq_restore(flags); 50 51 if (err) { 52 *again = true; 53 return skb; 54 } 55 56 if (skb_is_gso(skb)) { 57 struct net_device *dev = skb->dev; 58 59 if (unlikely(!x->xso.offload_handle || (x->xso.dev != dev))) { 60 struct sk_buff *segs; 61 62 /* Packet got rerouted, fixup features and segment it. */ 63 esp_features = esp_features & ~(NETIF_F_HW_ESP 64 | NETIF_F_GSO_ESP); 65 66 segs = skb_gso_segment(skb, esp_features); 67 if (IS_ERR(segs)) { 68 kfree_skb(skb); 69 atomic_long_inc(&dev->tx_dropped); 70 return NULL; 71 } else { 72 consume_skb(skb); 73 skb = segs; 74 } 75 } 76 } 77 78 if (!skb->next) { 79 x->outer_mode->xmit(x, skb); 80 81 xo->flags |= XFRM_DEV_RESUME; 82 83 err = x->type_offload->xmit(x, skb, esp_features); 84 if (err) { 85 if (err == -EINPROGRESS) 86 return NULL; 87 88 XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR); 89 kfree_skb(skb); 90 return NULL; 91 } 92 93 skb_push(skb, skb->data - skb_mac_header(skb)); 94 95 return skb; 96 } 97 98 skb2 = skb; 99 100 do { 101 struct sk_buff *nskb = skb2->next; 102 skb2->next = NULL; 103 104 xo = xfrm_offload(skb2); 105 xo->flags |= XFRM_DEV_RESUME; 106 107 x->outer_mode->xmit(x, skb2); 108 109 err = x->type_offload->xmit(x, skb2, esp_features); 110 if (!err) { 111 skb2->next = nskb; 112 } else if (err != -EINPROGRESS) { 113 XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR); 114 skb2->next = nskb; 115 kfree_skb_list(skb2); 116 return NULL; 117 } else { 118 if (skb == skb2) 119 skb = nskb; 120 121 if (!skb) 122 return NULL; 123 124 goto skip_push; 125 } 126 127 skb_push(skb2, skb2->data - skb_mac_header(skb2)); 128 129 skip_push: 130 skb2 = nskb; 131 } while (skb2); 132 133 return skb; 134 } 135 EXPORT_SYMBOL_GPL(validate_xmit_xfrm); 136 137 int xfrm_dev_state_add(struct net *net, struct xfrm_state *x, 138 struct xfrm_user_offload *xuo) 139 { 140 int err; 141 struct dst_entry *dst; 142 struct net_device *dev; 143 struct xfrm_state_offload *xso = &x->xso; 144 xfrm_address_t *saddr; 145 xfrm_address_t *daddr; 146 147 if (!x->type_offload) 148 return -EINVAL; 149 150 /* We don't yet support UDP encapsulation and TFC padding. */ 151 if (x->encap || x->tfcpad) 152 return -EINVAL; 153 154 dev = dev_get_by_index(net, xuo->ifindex); 155 if (!dev) { 156 if (!(xuo->flags & XFRM_OFFLOAD_INBOUND)) { 157 saddr = &x->props.saddr; 158 daddr = &x->id.daddr; 159 } else { 160 saddr = &x->id.daddr; 161 daddr = &x->props.saddr; 162 } 163 164 dst = __xfrm_dst_lookup(net, 0, 0, saddr, daddr, 165 x->props.family, 166 xfrm_smark_get(0, x)); 167 if (IS_ERR(dst)) 168 return 0; 169 170 dev = dst->dev; 171 172 dev_hold(dev); 173 dst_release(dst); 174 } 175 176 if (!dev->xfrmdev_ops || !dev->xfrmdev_ops->xdo_dev_state_add) { 177 xso->dev = NULL; 178 dev_put(dev); 179 return 0; 180 } 181 182 if (x->props.flags & XFRM_STATE_ESN && 183 !dev->xfrmdev_ops->xdo_dev_state_advance_esn) { 184 xso->dev = NULL; 185 dev_put(dev); 186 return -EINVAL; 187 } 188 189 xso->dev = dev; 190 xso->num_exthdrs = 1; 191 xso->flags = xuo->flags; 192 193 err = dev->xfrmdev_ops->xdo_dev_state_add(x); 194 if (err) { 195 xso->dev = NULL; 196 dev_put(dev); 197 return err; 198 } 199 200 return 0; 201 } 202 EXPORT_SYMBOL_GPL(xfrm_dev_state_add); 203 204 bool xfrm_dev_offload_ok(struct sk_buff *skb, struct xfrm_state *x) 205 { 206 int mtu; 207 struct dst_entry *dst = skb_dst(skb); 208 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 209 struct net_device *dev = x->xso.dev; 210 211 if (!x->type_offload || x->encap) 212 return false; 213 214 if ((!dev || (x->xso.offload_handle && (dev == xfrm_dst_path(dst)->dev))) && 215 (!xdst->child->xfrm && x->type->get_mtu)) { 216 mtu = x->type->get_mtu(x, xdst->child_mtu_cached); 217 218 if (skb->len <= mtu) 219 goto ok; 220 221 if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu)) 222 goto ok; 223 } 224 225 return false; 226 227 ok: 228 if (dev && dev->xfrmdev_ops && dev->xfrmdev_ops->xdo_dev_offload_ok) 229 return x->xso.dev->xfrmdev_ops->xdo_dev_offload_ok(skb, x); 230 231 return true; 232 } 233 EXPORT_SYMBOL_GPL(xfrm_dev_offload_ok); 234 235 void xfrm_dev_resume(struct sk_buff *skb) 236 { 237 struct net_device *dev = skb->dev; 238 int ret = NETDEV_TX_BUSY; 239 struct netdev_queue *txq; 240 struct softnet_data *sd; 241 unsigned long flags; 242 243 rcu_read_lock(); 244 txq = netdev_pick_tx(dev, skb, NULL); 245 246 HARD_TX_LOCK(dev, txq, smp_processor_id()); 247 if (!netif_xmit_frozen_or_stopped(txq)) 248 skb = dev_hard_start_xmit(skb, dev, txq, &ret); 249 HARD_TX_UNLOCK(dev, txq); 250 251 if (!dev_xmit_complete(ret)) { 252 local_irq_save(flags); 253 sd = this_cpu_ptr(&softnet_data); 254 skb_queue_tail(&sd->xfrm_backlog, skb); 255 raise_softirq_irqoff(NET_TX_SOFTIRQ); 256 local_irq_restore(flags); 257 } 258 rcu_read_unlock(); 259 } 260 EXPORT_SYMBOL_GPL(xfrm_dev_resume); 261 262 void xfrm_dev_backlog(struct softnet_data *sd) 263 { 264 struct sk_buff_head *xfrm_backlog = &sd->xfrm_backlog; 265 struct sk_buff_head list; 266 struct sk_buff *skb; 267 268 if (skb_queue_empty(xfrm_backlog)) 269 return; 270 271 __skb_queue_head_init(&list); 272 273 spin_lock(&xfrm_backlog->lock); 274 skb_queue_splice_init(xfrm_backlog, &list); 275 spin_unlock(&xfrm_backlog->lock); 276 277 while (!skb_queue_empty(&list)) { 278 skb = __skb_dequeue(&list); 279 xfrm_dev_resume(skb); 280 } 281 282 } 283 #endif 284 285 static int xfrm_api_check(struct net_device *dev) 286 { 287 #ifdef CONFIG_XFRM_OFFLOAD 288 if ((dev->features & NETIF_F_HW_ESP_TX_CSUM) && 289 !(dev->features & NETIF_F_HW_ESP)) 290 return NOTIFY_BAD; 291 292 if ((dev->features & NETIF_F_HW_ESP) && 293 (!(dev->xfrmdev_ops && 294 dev->xfrmdev_ops->xdo_dev_state_add && 295 dev->xfrmdev_ops->xdo_dev_state_delete))) 296 return NOTIFY_BAD; 297 #else 298 if (dev->features & (NETIF_F_HW_ESP | NETIF_F_HW_ESP_TX_CSUM)) 299 return NOTIFY_BAD; 300 #endif 301 302 return NOTIFY_DONE; 303 } 304 305 static int xfrm_dev_register(struct net_device *dev) 306 { 307 return xfrm_api_check(dev); 308 } 309 310 static int xfrm_dev_feat_change(struct net_device *dev) 311 { 312 return xfrm_api_check(dev); 313 } 314 315 static int xfrm_dev_down(struct net_device *dev) 316 { 317 if (dev->features & NETIF_F_HW_ESP) 318 xfrm_dev_state_flush(dev_net(dev), dev, true); 319 320 return NOTIFY_DONE; 321 } 322 323 static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr) 324 { 325 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 326 327 switch (event) { 328 case NETDEV_REGISTER: 329 return xfrm_dev_register(dev); 330 331 case NETDEV_FEAT_CHANGE: 332 return xfrm_dev_feat_change(dev); 333 334 case NETDEV_DOWN: 335 return xfrm_dev_down(dev); 336 } 337 return NOTIFY_DONE; 338 } 339 340 static struct notifier_block xfrm_dev_notifier = { 341 .notifier_call = xfrm_dev_event, 342 }; 343 344 void __init xfrm_dev_init(void) 345 { 346 register_netdevice_notifier(&xfrm_dev_notifier); 347 } 348