1 /* 2 * Linux NET3: IP/IP protocol decoder modified to support 3 * virtual tunnel interface 4 * 5 * Authors: 6 * Saurabh Mohan (saurabh.mohan@vyatta.com) 05/07/2012 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License 10 * as published by the Free Software Foundation; either version 11 * 2 of the License, or (at your option) any later version. 12 * 13 */ 14 15 /* 16 This version of net/ipv4/ip_vti.c is cloned of net/ipv4/ipip.c 17 18 For comments look at net/ipv4/ip_gre.c --ANK 19 */ 20 21 22 #include <linux/capability.h> 23 #include <linux/module.h> 24 #include <linux/types.h> 25 #include <linux/kernel.h> 26 #include <linux/uaccess.h> 27 #include <linux/skbuff.h> 28 #include <linux/netdevice.h> 29 #include <linux/in.h> 30 #include <linux/tcp.h> 31 #include <linux/udp.h> 32 #include <linux/if_arp.h> 33 #include <linux/mroute.h> 34 #include <linux/init.h> 35 #include <linux/netfilter_ipv4.h> 36 #include <linux/if_ether.h> 37 38 #include <net/sock.h> 39 #include <net/ip.h> 40 #include <net/icmp.h> 41 #include <net/ip_tunnels.h> 42 #include <net/inet_ecn.h> 43 #include <net/xfrm.h> 44 #include <net/net_namespace.h> 45 #include <net/netns/generic.h> 46 47 static struct rtnl_link_ops vti_link_ops __read_mostly; 48 49 static int vti_net_id __read_mostly; 50 static int vti_tunnel_init(struct net_device *dev); 51 52 /* We dont digest the packet therefore let the packet pass */ 53 static int vti_rcv(struct sk_buff *skb) 54 { 55 struct ip_tunnel *tunnel; 56 const struct iphdr *iph = ip_hdr(skb); 57 struct net *net = dev_net(skb->dev); 58 struct ip_tunnel_net *itn = net_generic(net, vti_net_id); 59 60 tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY, 61 iph->saddr, iph->daddr, 0); 62 if (tunnel != NULL) { 63 struct pcpu_tstats *tstats; 64 65 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) 66 return -1; 67 68 tstats = this_cpu_ptr(tunnel->dev->tstats); 69 u64_stats_update_begin(&tstats->syncp); 70 tstats->rx_packets++; 71 tstats->rx_bytes += skb->len; 72 u64_stats_update_end(&tstats->syncp); 73 74 skb->mark = 0; 75 secpath_reset(skb); 76 skb->dev = tunnel->dev; 77 return 1; 78 } 79 80 return -1; 81 } 82 83 /* This function assumes it is being called from dev_queue_xmit() 84 * and that skb is filled properly by that function. 85 */ 86 87 static netdev_tx_t vti_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) 88 { 89 struct ip_tunnel *tunnel = netdev_priv(dev); 90 struct iphdr *tiph = &tunnel->parms.iph; 91 u8 tos; 92 struct rtable *rt; /* Route to the other host */ 93 struct net_device *tdev; /* Device to other host */ 94 struct iphdr *old_iph = ip_hdr(skb); 95 __be32 dst = tiph->daddr; 96 struct flowi4 fl4; 97 int err; 98 99 if (skb->protocol != htons(ETH_P_IP)) 100 goto tx_error; 101 102 tos = old_iph->tos; 103 104 memset(&fl4, 0, sizeof(fl4)); 105 flowi4_init_output(&fl4, tunnel->parms.link, 106 be32_to_cpu(tunnel->parms.i_key), RT_TOS(tos), 107 RT_SCOPE_UNIVERSE, 108 IPPROTO_IPIP, 0, 109 dst, tiph->saddr, 0, 0); 110 rt = ip_route_output_key(dev_net(dev), &fl4); 111 if (IS_ERR(rt)) { 112 dev->stats.tx_carrier_errors++; 113 goto tx_error_icmp; 114 } 115 /* if there is no transform then this tunnel is not functional. 116 * Or if the xfrm is not mode tunnel. 117 */ 118 if (!rt->dst.xfrm || 119 rt->dst.xfrm->props.mode != XFRM_MODE_TUNNEL) { 120 dev->stats.tx_carrier_errors++; 121 goto tx_error_icmp; 122 } 123 tdev = rt->dst.dev; 124 125 if (tdev == dev) { 126 ip_rt_put(rt); 127 dev->stats.collisions++; 128 goto tx_error; 129 } 130 131 if (tunnel->err_count > 0) { 132 if (time_before(jiffies, 133 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { 134 tunnel->err_count--; 135 dst_link_failure(skb); 136 } else 137 tunnel->err_count = 0; 138 } 139 140 memset(IPCB(skb), 0, sizeof(*IPCB(skb))); 141 skb_dst_drop(skb); 142 skb_dst_set(skb, &rt->dst); 143 nf_reset(skb); 144 skb->dev = skb_dst(skb)->dev; 145 146 err = dst_output(skb); 147 if (net_xmit_eval(err) == 0) 148 err = skb->len; 149 iptunnel_xmit_stats(err, &dev->stats, dev->tstats); 150 return NETDEV_TX_OK; 151 152 tx_error_icmp: 153 dst_link_failure(skb); 154 tx_error: 155 dev->stats.tx_errors++; 156 dev_kfree_skb(skb); 157 return NETDEV_TX_OK; 158 } 159 160 static int 161 vti_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 162 { 163 int err = 0; 164 struct ip_tunnel_parm p; 165 166 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 167 return -EFAULT; 168 169 if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) { 170 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP || 171 p.iph.ihl != 5) 172 return -EINVAL; 173 } 174 175 err = ip_tunnel_ioctl(dev, &p, cmd); 176 if (err) 177 return err; 178 179 if (cmd != SIOCDELTUNNEL) { 180 p.i_flags |= GRE_KEY | VTI_ISVTI; 181 p.o_flags |= GRE_KEY; 182 } 183 184 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 185 return -EFAULT; 186 return 0; 187 } 188 189 static const struct net_device_ops vti_netdev_ops = { 190 .ndo_init = vti_tunnel_init, 191 .ndo_uninit = ip_tunnel_uninit, 192 .ndo_start_xmit = vti_tunnel_xmit, 193 .ndo_do_ioctl = vti_tunnel_ioctl, 194 .ndo_change_mtu = ip_tunnel_change_mtu, 195 .ndo_get_stats64 = ip_tunnel_get_stats64, 196 }; 197 198 static void vti_tunnel_setup(struct net_device *dev) 199 { 200 dev->netdev_ops = &vti_netdev_ops; 201 ip_tunnel_setup(dev, vti_net_id); 202 } 203 204 static int vti_tunnel_init(struct net_device *dev) 205 { 206 struct ip_tunnel *tunnel = netdev_priv(dev); 207 struct iphdr *iph = &tunnel->parms.iph; 208 209 memcpy(dev->dev_addr, &iph->saddr, 4); 210 memcpy(dev->broadcast, &iph->daddr, 4); 211 212 dev->type = ARPHRD_TUNNEL; 213 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); 214 dev->mtu = ETH_DATA_LEN; 215 dev->flags = IFF_NOARP; 216 dev->iflink = 0; 217 dev->addr_len = 4; 218 dev->features |= NETIF_F_NETNS_LOCAL; 219 dev->features |= NETIF_F_LLTX; 220 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; 221 222 return ip_tunnel_init(dev); 223 } 224 225 static void __net_init vti_fb_tunnel_init(struct net_device *dev) 226 { 227 struct ip_tunnel *tunnel = netdev_priv(dev); 228 struct iphdr *iph = &tunnel->parms.iph; 229 230 iph->version = 4; 231 iph->protocol = IPPROTO_IPIP; 232 iph->ihl = 5; 233 } 234 235 static struct xfrm_tunnel_notifier vti_handler __read_mostly = { 236 .handler = vti_rcv, 237 .priority = 1, 238 }; 239 240 static int __net_init vti_init_net(struct net *net) 241 { 242 int err; 243 struct ip_tunnel_net *itn; 244 245 err = ip_tunnel_init_net(net, vti_net_id, &vti_link_ops, "ip_vti0"); 246 if (err) 247 return err; 248 itn = net_generic(net, vti_net_id); 249 vti_fb_tunnel_init(itn->fb_tunnel_dev); 250 return 0; 251 } 252 253 static void __net_exit vti_exit_net(struct net *net) 254 { 255 struct ip_tunnel_net *itn = net_generic(net, vti_net_id); 256 ip_tunnel_delete_net(itn, &vti_link_ops); 257 } 258 259 static struct pernet_operations vti_net_ops = { 260 .init = vti_init_net, 261 .exit = vti_exit_net, 262 .id = &vti_net_id, 263 .size = sizeof(struct ip_tunnel_net), 264 }; 265 266 static int vti_tunnel_validate(struct nlattr *tb[], struct nlattr *data[]) 267 { 268 return 0; 269 } 270 271 static void vti_netlink_parms(struct nlattr *data[], 272 struct ip_tunnel_parm *parms) 273 { 274 memset(parms, 0, sizeof(*parms)); 275 276 parms->iph.protocol = IPPROTO_IPIP; 277 278 if (!data) 279 return; 280 281 if (data[IFLA_VTI_LINK]) 282 parms->link = nla_get_u32(data[IFLA_VTI_LINK]); 283 284 if (data[IFLA_VTI_IKEY]) 285 parms->i_key = nla_get_be32(data[IFLA_VTI_IKEY]); 286 287 if (data[IFLA_VTI_OKEY]) 288 parms->o_key = nla_get_be32(data[IFLA_VTI_OKEY]); 289 290 if (data[IFLA_VTI_LOCAL]) 291 parms->iph.saddr = nla_get_be32(data[IFLA_VTI_LOCAL]); 292 293 if (data[IFLA_VTI_REMOTE]) 294 parms->iph.daddr = nla_get_be32(data[IFLA_VTI_REMOTE]); 295 296 } 297 298 static int vti_newlink(struct net *src_net, struct net_device *dev, 299 struct nlattr *tb[], struct nlattr *data[]) 300 { 301 struct ip_tunnel_parm parms; 302 303 vti_netlink_parms(data, &parms); 304 return ip_tunnel_newlink(dev, tb, &parms); 305 } 306 307 static int vti_changelink(struct net_device *dev, struct nlattr *tb[], 308 struct nlattr *data[]) 309 { 310 struct ip_tunnel_parm p; 311 312 vti_netlink_parms(data, &p); 313 return ip_tunnel_changelink(dev, tb, &p); 314 } 315 316 static size_t vti_get_size(const struct net_device *dev) 317 { 318 return 319 /* IFLA_VTI_LINK */ 320 nla_total_size(4) + 321 /* IFLA_VTI_IKEY */ 322 nla_total_size(4) + 323 /* IFLA_VTI_OKEY */ 324 nla_total_size(4) + 325 /* IFLA_VTI_LOCAL */ 326 nla_total_size(4) + 327 /* IFLA_VTI_REMOTE */ 328 nla_total_size(4) + 329 0; 330 } 331 332 static int vti_fill_info(struct sk_buff *skb, const struct net_device *dev) 333 { 334 struct ip_tunnel *t = netdev_priv(dev); 335 struct ip_tunnel_parm *p = &t->parms; 336 337 nla_put_u32(skb, IFLA_VTI_LINK, p->link); 338 nla_put_be32(skb, IFLA_VTI_IKEY, p->i_key); 339 nla_put_be32(skb, IFLA_VTI_OKEY, p->o_key); 340 nla_put_be32(skb, IFLA_VTI_LOCAL, p->iph.saddr); 341 nla_put_be32(skb, IFLA_VTI_REMOTE, p->iph.daddr); 342 343 return 0; 344 } 345 346 static const struct nla_policy vti_policy[IFLA_VTI_MAX + 1] = { 347 [IFLA_VTI_LINK] = { .type = NLA_U32 }, 348 [IFLA_VTI_IKEY] = { .type = NLA_U32 }, 349 [IFLA_VTI_OKEY] = { .type = NLA_U32 }, 350 [IFLA_VTI_LOCAL] = { .len = FIELD_SIZEOF(struct iphdr, saddr) }, 351 [IFLA_VTI_REMOTE] = { .len = FIELD_SIZEOF(struct iphdr, daddr) }, 352 }; 353 354 static struct rtnl_link_ops vti_link_ops __read_mostly = { 355 .kind = "vti", 356 .maxtype = IFLA_VTI_MAX, 357 .policy = vti_policy, 358 .priv_size = sizeof(struct ip_tunnel), 359 .setup = vti_tunnel_setup, 360 .validate = vti_tunnel_validate, 361 .newlink = vti_newlink, 362 .changelink = vti_changelink, 363 .get_size = vti_get_size, 364 .fill_info = vti_fill_info, 365 }; 366 367 static int __init vti_init(void) 368 { 369 int err; 370 371 pr_info("IPv4 over IPSec tunneling driver\n"); 372 373 err = register_pernet_device(&vti_net_ops); 374 if (err < 0) 375 return err; 376 err = xfrm4_mode_tunnel_input_register(&vti_handler); 377 if (err < 0) { 378 unregister_pernet_device(&vti_net_ops); 379 pr_info("vti init: can't register tunnel\n"); 380 } 381 382 err = rtnl_link_register(&vti_link_ops); 383 if (err < 0) 384 goto rtnl_link_failed; 385 386 return err; 387 388 rtnl_link_failed: 389 xfrm4_mode_tunnel_input_deregister(&vti_handler); 390 unregister_pernet_device(&vti_net_ops); 391 return err; 392 } 393 394 static void __exit vti_fini(void) 395 { 396 rtnl_link_unregister(&vti_link_ops); 397 if (xfrm4_mode_tunnel_input_deregister(&vti_handler)) 398 pr_info("vti close: can't deregister tunnel\n"); 399 400 unregister_pernet_device(&vti_net_ops); 401 } 402 403 module_init(vti_init); 404 module_exit(vti_fini); 405 MODULE_LICENSE("GPL"); 406 MODULE_ALIAS_RTNL_LINK("vti"); 407 MODULE_ALIAS_NETDEV("ip_vti0"); 408