drivers/net/bareudp.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Bareudp: UDP  tunnel encasulation for different Payload types like
   3  * MPLS, NSH, IP, etc.
   4  * Copyright (c) 2019 Nokia, Inc.
   5  * Authors:  Martin Varghese, <[email protected]>
   6  */
   7
   8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   9
  10 #include <linux/kernel.h>
  11 #include <linux/module.h>
  12 #include <linux/etherdevice.h>
  13 #include <linux/hash.h>
  14 #include <net/dst_metadata.h>
  15 #include <net/gro_cells.h>
  16 #include <net/rtnetlink.h>
  17 #include <net/protocol.h>
  18 #include <net/ip6_tunnel.h>
  19 #include <net/ip_tunnels.h>
  20 #include <net/udp_tunnel.h>
  21 #include <net/bareudp.h>
  22
  23 #define BAREUDP_BASE_HLEN sizeof(struct udphdr)
  24 #define BAREUDP_IPV4_HLEN (sizeof(struct iphdr) + \
  25                            sizeof(struct udphdr))
  26 #define BAREUDP_IPV6_HLEN (sizeof(struct ipv6hdr) + \
  27                            sizeof(struct udphdr))
  28
  29 static bool log_ecn_error = true;
  30 module_param(log_ecn_error, bool, 0644);
  31 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
  32
  33 /* per-network namespace private data for this module */
  34
  35 static unsigned int bareudp_net_id;
  36
  37 struct bareudp_net {
  38         struct list_head        bareudp_list;
  39 };
  40
  41 struct bareudp_conf {
  42         __be16 ethertype;
  43         __be16 port;
  44         u16 sport_min;
  45         bool multi_proto_mode;
  46 };
  47
  48 /* Pseudo network device */
  49 struct bareudp_dev {
  50         struct net         *net;        /* netns for packet i/o */
  51         struct net_device  *dev;        /* netdev for bareudp tunnel */
  52         __be16             ethertype;
  53         __be16             port;
  54         u16                sport_min;
  55         bool               multi_proto_mode;
  56         struct socket      __rcu *sock;
  57         struct list_head   next;        /* bareudp node  on namespace list */
  58         struct gro_cells   gro_cells;
  59 };
  60
  61 static int bareudp_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
  62 {
  63         struct metadata_dst *tun_dst = NULL;
  64         IP_TUNNEL_DECLARE_FLAGS(key) = { };
  65         struct bareudp_dev *bareudp;
  66         unsigned short family;
  67         unsigned int len;
  68         __be16 proto;
  69         void *oiph;
  70         int err;
  71         int nh;
  72
  73         bareudp = rcu_dereference_sk_user_data(sk);
  74         if (!bareudp)
  75                 goto drop;
  76
  77         if (skb->protocol ==  htons(ETH_P_IP))
  78                 family = AF_INET;
  79         else
  80                 family = AF_INET6;
  81
  82         if (bareudp->ethertype == htons(ETH_P_IP)) {
  83                 __u8 ipversion;
  84
  85                 if (skb_copy_bits(skb, BAREUDP_BASE_HLEN, &ipversion,
  86                                   sizeof(ipversion))) {
  87                         dev_core_stats_rx_dropped_inc(bareudp->dev);
  88                         goto drop;
  89                 }
  90                 ipversion >>= 4;
  91
  92                 if (ipversion == 4) {
  93                         proto = htons(ETH_P_IP);
  94                 } else if (ipversion == 6 && bareudp->multi_proto_mode) {
  95                         proto = htons(ETH_P_IPV6);
  96                 } else {
  97                         dev_core_stats_rx_dropped_inc(bareudp->dev);
  98                         goto drop;
  99                 }
 100         } else if (bareudp->ethertype == htons(ETH_P_MPLS_UC)) {
 101                 struct iphdr *tunnel_hdr;
 102
 103                 tunnel_hdr = (struct iphdr *)skb_network_header(skb);
 104                 if (tunnel_hdr->version == 4) {
 105                         if (!ipv4_is_multicast(tunnel_hdr->daddr)) {
 106                                 proto = bareudp->ethertype;
 107                         } else if (bareudp->multi_proto_mode &&
 108                                    ipv4_is_multicast(tunnel_hdr->daddr)) {
 109                                 proto = htons(ETH_P_MPLS_MC);
 110                         } else {
 111                                 dev_core_stats_rx_dropped_inc(bareudp->dev);
 112                                 goto drop;
 113                         }
 114                 } else {
 115                         int addr_type;
 116                         struct ipv6hdr *tunnel_hdr_v6;
 117
 118                         tunnel_hdr_v6 = (struct ipv6hdr *)skb_network_header(skb);
 119                         addr_type =
 120                         ipv6_addr_type((struct in6_addr *)&tunnel_hdr_v6->daddr);
 121                         if (!(addr_type & IPV6_ADDR_MULTICAST)) {
 122                                 proto = bareudp->ethertype;
 123                         } else if (bareudp->multi_proto_mode &&
 124                                    (addr_type & IPV6_ADDR_MULTICAST)) {
 125                                 proto = htons(ETH_P_MPLS_MC);
 126                         } else {
 127                                 dev_core_stats_rx_dropped_inc(bareudp->dev);
 128                                 goto drop;
 129                         }
 130                 }
 131         } else {
 132                 proto = bareudp->ethertype;
 133         }
 134
 135         if (iptunnel_pull_header(skb, BAREUDP_BASE_HLEN,
 136                                  proto,
 137                                  !net_eq(bareudp->net,
 138                                  dev_net(bareudp->dev)))) {
 139                 dev_core_stats_rx_dropped_inc(bareudp->dev);
 140                 goto drop;
 141         }
 142
 143         __set_bit(IP_TUNNEL_KEY_BIT, key);
 144
 145         tun_dst = udp_tun_rx_dst(skb, family, key, 0, 0);
 146         if (!tun_dst) {
 147                 dev_core_stats_rx_dropped_inc(bareudp->dev);
 148                 goto drop;
 149         }
 150         skb_dst_set(skb, &tun_dst->dst);
 151         skb->dev = bareudp->dev;
 152         skb_reset_mac_header(skb);
 153
 154         /* Save offset of outer header relative to skb->head,
 155          * because we are going to reset the network header to the inner header
 156          * and might change skb->head.
 157          */
 158         nh = skb_network_header(skb) - skb->head;
 159
 160         skb_reset_network_header(skb);
 161
 162         if (!pskb_inet_may_pull(skb)) {
 163                 DEV_STATS_INC(bareudp->dev, rx_length_errors);
 164                 DEV_STATS_INC(bareudp->dev, rx_errors);
 165                 goto drop;
 166         }
 167
 168         /* Get the outer header. */
 169         oiph = skb->head + nh;
 170
 171         if (!ipv6_mod_enabled() || family == AF_INET)
 172                 err = IP_ECN_decapsulate(oiph, skb);
 173         else
 174                 err = IP6_ECN_decapsulate(oiph, skb);
 175
 176         if (unlikely(err)) {
 177                 if (log_ecn_error) {
 178                         if  (!ipv6_mod_enabled() || family == AF_INET)
 179                                 net_info_ratelimited("non-ECT from %pI4 "
 180                                                      "with TOS=%#x\n",
 181                                                      &((struct iphdr *)oiph)->saddr,
 182                                                      ((struct iphdr *)oiph)->tos);
 183                         else
 184                                 net_info_ratelimited("non-ECT from %pI6\n",
 185                                                      &((struct ipv6hdr *)oiph)->saddr);
 186                 }
 187                 if (err > 1) {
 188                         DEV_STATS_INC(bareudp->dev, rx_frame_errors);
 189                         DEV_STATS_INC(bareudp->dev, rx_errors);
 190                         goto drop;
 191                 }
 192         }
 193
 194         len = skb->len;
 195         err = gro_cells_receive(&bareudp->gro_cells, skb);
 196         if (likely(err == NET_RX_SUCCESS))
 197                 dev_sw_netstats_rx_add(bareudp->dev, len);
 198
 199         return 0;
 200 drop:
 201         /* Consume bad packet */
 202         kfree_skb(skb);
 203
 204         return 0;
 205 }
 206
 207 static int bareudp_err_lookup(struct sock *sk, struct sk_buff *skb)
 208 {
 209         return 0;
 210 }
 211
 212 static int bareudp_init(struct net_device *dev)
 213 {
 214         struct bareudp_dev *bareudp = netdev_priv(dev);
 215         int err;
 216
 217         err = gro_cells_init(&bareudp->gro_cells, dev);
 218         if (err)
 219                 return err;
 220
 221         return 0;
 222 }
 223
 224 static void bareudp_uninit(struct net_device *dev)
 225 {
 226         struct bareudp_dev *bareudp = netdev_priv(dev);
 227
 228         gro_cells_destroy(&bareudp->gro_cells);
 229 }
 230
 231 static struct socket *bareudp_create_sock(struct net *net, __be16 port)
 232 {
 233         struct udp_port_cfg udp_conf;
 234         struct socket *sock;
 235         int err;
 236
 237         memset(&udp_conf, 0, sizeof(udp_conf));
 238
 239         if (ipv6_mod_enabled())
 240                 udp_conf.family = AF_INET6;
 241         else
 242                 udp_conf.family = AF_INET;
 243
 244         udp_conf.local_udp_port = port;
 245         /* Open UDP socket */
 246         err = udp_sock_create(net, &udp_conf, &sock);
 247         if (err < 0)
 248                 return ERR_PTR(err);
 249
 250         udp_allow_gso(sock->sk);
 251         return sock;
 252 }
 253
 254 /* Create new listen socket if needed */
 255 static int bareudp_socket_create(struct bareudp_dev *bareudp, __be16 port)
 256 {
 257         struct udp_tunnel_sock_cfg tunnel_cfg;
 258         struct socket *sock;
 259
 260         sock = bareudp_create_sock(bareudp->net, port);
 261         if (IS_ERR(sock))
 262                 return PTR_ERR(sock);
 263
 264         /* Mark socket as an encapsulation socket */
 265         memset(&tunnel_cfg, 0, sizeof(tunnel_cfg));
 266         tunnel_cfg.sk_user_data = bareudp;
 267         tunnel_cfg.encap_type = 1;
 268         tunnel_cfg.encap_rcv = bareudp_udp_encap_recv;
 269         tunnel_cfg.encap_err_lookup = bareudp_err_lookup;
 270         tunnel_cfg.encap_destroy = NULL;
 271         setup_udp_tunnel_sock(bareudp->net, sock, &tunnel_cfg);
 272
 273         rcu_assign_pointer(bareudp->sock, sock);
 274         return 0;
 275 }
 276
 277 static int bareudp_open(struct net_device *dev)
 278 {
 279         struct bareudp_dev *bareudp = netdev_priv(dev);
 280         int ret = 0;
 281
 282         ret =  bareudp_socket_create(bareudp, bareudp->port);
 283         return ret;
 284 }
 285
 286 static void bareudp_sock_release(struct bareudp_dev *bareudp)
 287 {
 288         struct socket *sock;
 289
 290         sock = bareudp->sock;
 291         rcu_assign_pointer(bareudp->sock, NULL);
 292         synchronize_net();
 293         udp_tunnel_sock_release(sock);
 294 }
 295
 296 static int bareudp_stop(struct net_device *dev)
 297 {
 298         struct bareudp_dev *bareudp = netdev_priv(dev);
 299
 300         bareudp_sock_release(bareudp);
 301         return 0;
 302 }
 303
 304 static int bareudp_xmit_skb(struct sk_buff *skb, struct net_device *dev,
 305                             struct bareudp_dev *bareudp,
 306                             const struct ip_tunnel_info *info)
 307 {
 308         bool udp_sum = test_bit(IP_TUNNEL_CSUM_BIT, info->key.tun_flags);
 309         bool xnet = !net_eq(bareudp->net, dev_net(bareudp->dev));
 310         bool use_cache = ip_tunnel_dst_cache_usable(skb, info);
 311         struct socket *sock = rcu_dereference(bareudp->sock);
 312         const struct ip_tunnel_key *key = &info->key;
 313         struct rtable *rt;
 314         __be16 sport, df;
 315         int min_headroom;
 316         __u8 tos, ttl;
 317         __be32 saddr;
 318         int err;
 319
 320         if (skb_vlan_inet_prepare(skb, skb->protocol != htons(ETH_P_TEB)))
 321                 return -EINVAL;
 322
 323         if (!sock)
 324                 return -ESHUTDOWN;
 325
 326         sport = udp_flow_src_port(bareudp->net, skb,
 327                                   bareudp->sport_min, USHRT_MAX,
 328                                   true);
 329         rt = udp_tunnel_dst_lookup(skb, dev, bareudp->net, 0, &saddr, &info->key,
 330                                    sport, bareudp->port, key->tos,
 331                                    use_cache ?
 332                                    (struct dst_cache *)&info->dst_cache : NULL);
 333
 334         if (IS_ERR(rt))
 335                 return PTR_ERR(rt);
 336
 337         skb_tunnel_check_pmtu(skb, &rt->dst,
 338                               BAREUDP_IPV4_HLEN + info->options_len, false);
 339
 340         tos = ip_tunnel_ecn_encap(key->tos, ip_hdr(skb), skb);
 341         ttl = key->ttl;
 342         df = test_bit(IP_TUNNEL_DONT_FRAGMENT_BIT, key->tun_flags) ?
 343              htons(IP_DF) : 0;
 344         skb_scrub_packet(skb, xnet);
 345
 346         err = -ENOSPC;
 347         if (!skb_pull(skb, skb_network_offset(skb)))
 348                 goto free_dst;
 349
 350         min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len +
 351                 BAREUDP_BASE_HLEN + info->options_len + sizeof(struct iphdr);
 352
 353         err = skb_cow_head(skb, min_headroom);
 354         if (unlikely(err))
 355                 goto free_dst;
 356
 357         err = udp_tunnel_handle_offloads(skb, udp_sum);
 358         if (err)
 359                 goto free_dst;
 360
 361         skb_set_inner_protocol(skb, bareudp->ethertype);
 362         udp_tunnel_xmit_skb(rt, sock->sk, skb, saddr, info->key.u.ipv4.dst,
 363                             tos, ttl, df, sport, bareudp->port,
 364                             !net_eq(bareudp->net, dev_net(bareudp->dev)),
 365                             !test_bit(IP_TUNNEL_CSUM_BIT,
 366                                       info->key.tun_flags));
 367         return 0;
 368
 369 free_dst:
 370         dst_release(&rt->dst);
 371         return err;
 372 }
 373
 374 static int bareudp6_xmit_skb(struct sk_buff *skb, struct net_device *dev,
 375                              struct bareudp_dev *bareudp,
 376                              const struct ip_tunnel_info *info)
 377 {
 378         bool udp_sum = test_bit(IP_TUNNEL_CSUM_BIT, info->key.tun_flags);
 379         bool xnet = !net_eq(bareudp->net, dev_net(bareudp->dev));
 380         bool use_cache = ip_tunnel_dst_cache_usable(skb, info);
 381         struct socket *sock  = rcu_dereference(bareudp->sock);
 382         const struct ip_tunnel_key *key = &info->key;
 383         struct dst_entry *dst = NULL;
 384         struct in6_addr saddr, daddr;
 385         int min_headroom;
 386         __u8 prio, ttl;
 387         __be16 sport;
 388         int err;
 389
 390         if (skb_vlan_inet_prepare(skb, skb->protocol != htons(ETH_P_TEB)))
 391                 return -EINVAL;
 392
 393         if (!sock)
 394                 return -ESHUTDOWN;
 395
 396         sport = udp_flow_src_port(bareudp->net, skb,
 397                                   bareudp->sport_min, USHRT_MAX,
 398                                   true);
 399         dst = udp_tunnel6_dst_lookup(skb, dev, bareudp->net, sock, 0, &saddr,
 400                                      key, sport, bareudp->port, key->tos,
 401                                      use_cache ?
 402                                      (struct dst_cache *) &info->dst_cache : NULL);
 403         if (IS_ERR(dst))
 404                 return PTR_ERR(dst);
 405
 406         skb_tunnel_check_pmtu(skb, dst, BAREUDP_IPV6_HLEN + info->options_len,
 407                               false);
 408
 409         prio = ip_tunnel_ecn_encap(key->tos, ip_hdr(skb), skb);
 410         ttl = key->ttl;
 411
 412         skb_scrub_packet(skb, xnet);
 413
 414         err = -ENOSPC;
 415         if (!skb_pull(skb, skb_network_offset(skb)))
 416                 goto free_dst;
 417
 418         min_headroom = LL_RESERVED_SPACE(dst->dev) + dst->header_len +
 419                 BAREUDP_BASE_HLEN + info->options_len + sizeof(struct ipv6hdr);
 420
 421         err = skb_cow_head(skb, min_headroom);
 422         if (unlikely(err))
 423                 goto free_dst;
 424
 425         err = udp_tunnel_handle_offloads(skb, udp_sum);
 426         if (err)
 427                 goto free_dst;
 428
 429         daddr = info->key.u.ipv6.dst;
 430         udp_tunnel6_xmit_skb(dst, sock->sk, skb, dev,
 431                              &saddr, &daddr, prio, ttl,
 432                              info->key.label, sport, bareudp->port,
 433                              !test_bit(IP_TUNNEL_CSUM_BIT,
 434                                        info->key.tun_flags));
 435         return 0;
 436
 437 free_dst:
 438         dst_release(dst);
 439         return err;
 440 }
 441
 442 static bool bareudp_proto_valid(struct bareudp_dev *bareudp, __be16 proto)
 443 {
 444         if (bareudp->ethertype == proto)
 445                 return true;
 446
 447         if (!bareudp->multi_proto_mode)
 448                 return false;
 449
 450         if (bareudp->ethertype == htons(ETH_P_MPLS_UC) &&
 451             proto == htons(ETH_P_MPLS_MC))
 452                 return true;
 453
 454         if (bareudp->ethertype == htons(ETH_P_IP) &&
 455             proto == htons(ETH_P_IPV6))
 456                 return true;
 457
 458         return false;
 459 }
 460
 461 static netdev_tx_t bareudp_xmit(struct sk_buff *skb, struct net_device *dev)
 462 {
 463         struct bareudp_dev *bareudp = netdev_priv(dev);
 464         struct ip_tunnel_info *info = NULL;
 465         int err;
 466
 467         if (!bareudp_proto_valid(bareudp, skb->protocol)) {
 468                 err = -EINVAL;
 469                 goto tx_error;
 470         }
 471
 472         info = skb_tunnel_info(skb);
 473         if (unlikely(!info || !(info->mode & IP_TUNNEL_INFO_TX))) {
 474                 err = -EINVAL;
 475                 goto tx_error;
 476         }
 477
 478         rcu_read_lock();
 479         if (ipv6_mod_enabled() && info->mode & IP_TUNNEL_INFO_IPV6)
 480                 err = bareudp6_xmit_skb(skb, dev, bareudp, info);
 481         else
 482                 err = bareudp_xmit_skb(skb, dev, bareudp, info);
 483
 484         rcu_read_unlock();
 485
 486         if (likely(!err))
 487                 return NETDEV_TX_OK;
 488 tx_error:
 489         dev_kfree_skb(skb);
 490
 491         if (err == -ELOOP)
 492                 DEV_STATS_INC(dev, collisions);
 493         else if (err == -ENETUNREACH)
 494                 DEV_STATS_INC(dev, tx_carrier_errors);
 495
 496         DEV_STATS_INC(dev, tx_errors);
 497         return NETDEV_TX_OK;
 498 }
 499
 500 static int bareudp_fill_metadata_dst(struct net_device *dev,
 501                                      struct sk_buff *skb)
 502 {
 503         struct ip_tunnel_info *info = skb_tunnel_info(skb);
 504         struct bareudp_dev *bareudp = netdev_priv(dev);
 505         bool use_cache;
 506         __be16 sport;
 507
 508         use_cache = ip_tunnel_dst_cache_usable(skb, info);
 509         sport = udp_flow_src_port(bareudp->net, skb,
 510                                   bareudp->sport_min, USHRT_MAX,
 511                                   true);
 512
 513         if (!ipv6_mod_enabled() || ip_tunnel_info_af(info) == AF_INET) {
 514                 struct rtable *rt;
 515                 __be32 saddr;
 516
 517                 rt = udp_tunnel_dst_lookup(skb, dev, bareudp->net, 0, &saddr,
 518                                            &info->key, sport, bareudp->port,
 519                                            info->key.tos,
 520                                            use_cache ? &info->dst_cache : NULL);
 521                 if (IS_ERR(rt))
 522                         return PTR_ERR(rt);
 523
 524                 ip_rt_put(rt);
 525                 info->key.u.ipv4.src = saddr;
 526         } else if (ip_tunnel_info_af(info) == AF_INET6) {
 527                 struct dst_entry *dst;
 528                 struct in6_addr saddr;
 529                 struct socket *sock = rcu_dereference(bareudp->sock);
 530
 531                 dst = udp_tunnel6_dst_lookup(skb, dev, bareudp->net, sock,
 532                                              0, &saddr, &info->key,
 533                                              sport, bareudp->port, info->key.tos,
 534                                              use_cache ? &info->dst_cache : NULL);
 535                 if (IS_ERR(dst))
 536                         return PTR_ERR(dst);
 537
 538                 dst_release(dst);
 539                 info->key.u.ipv6.src = saddr;
 540         } else {
 541                 return -EINVAL;
 542         }
 543
 544         info->key.tp_src = sport;
 545         info->key.tp_dst = bareudp->port;
 546         return 0;
 547 }
 548
 549 static const struct net_device_ops bareudp_netdev_ops = {
 550         .ndo_init               = bareudp_init,
 551         .ndo_uninit             = bareudp_uninit,
 552         .ndo_open               = bareudp_open,
 553         .ndo_stop               = bareudp_stop,
 554         .ndo_start_xmit         = bareudp_xmit,
 555         .ndo_fill_metadata_dst  = bareudp_fill_metadata_dst,
 556 };
 557
 558 static const struct nla_policy bareudp_policy[IFLA_BAREUDP_MAX + 1] = {
 559         [IFLA_BAREUDP_PORT]                = { .type = NLA_U16 },
 560         [IFLA_BAREUDP_ETHERTYPE]           = { .type = NLA_U16 },
 561         [IFLA_BAREUDP_SRCPORT_MIN]         = { .type = NLA_U16 },
 562         [IFLA_BAREUDP_MULTIPROTO_MODE]     = { .type = NLA_FLAG },
 563 };
 564
 565 /* Info for udev, that this is a virtual tunnel endpoint */
 566 static const struct device_type bareudp_type = {
 567         .name = "bareudp",
 568 };
 569
 570 /* Initialize the device structure. */
 571 static void bareudp_setup(struct net_device *dev)
 572 {
 573         dev->netdev_ops = &bareudp_netdev_ops;
 574         dev->needs_free_netdev = true;
 575         SET_NETDEV_DEVTYPE(dev, &bareudp_type);
 576         dev->features    |= NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_FRAGLIST;
 577         dev->features    |= NETIF_F_RXCSUM;
 578         dev->features    |= NETIF_F_GSO_SOFTWARE;
 579         dev->hw_features |= NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_FRAGLIST;
 580         dev->hw_features |= NETIF_F_RXCSUM;
 581         dev->hw_features |= NETIF_F_GSO_SOFTWARE;
 582         dev->hard_header_len = 0;
 583         dev->addr_len = 0;
 584         dev->mtu = ETH_DATA_LEN;
 585         dev->min_mtu = IPV4_MIN_MTU;
 586         dev->max_mtu = IP_MAX_MTU - BAREUDP_BASE_HLEN;
 587         dev->type = ARPHRD_NONE;
 588         netif_keep_dst(dev);
 589         dev->priv_flags |= IFF_NO_QUEUE;
 590         dev->lltx = true;
 591         dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
 592         dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
 593 }
 594
 595 static int bareudp_validate(struct nlattr *tb[], struct nlattr *data[],
 596                             struct netlink_ext_ack *extack)
 597 {
 598         if (!data) {
 599                 NL_SET_ERR_MSG(extack,
 600                                "Not enough attributes provided to perform the operation");
 601                 return -EINVAL;
 602         }
 603         return 0;
 604 }
 605
 606 static int bareudp2info(struct nlattr *data[], struct bareudp_conf *conf,
 607                         struct netlink_ext_ack *extack)
 608 {
 609         memset(conf, 0, sizeof(*conf));
 610
 611         if (!data[IFLA_BAREUDP_PORT]) {
 612                 NL_SET_ERR_MSG(extack, "port not specified");
 613                 return -EINVAL;
 614         }
 615         if (!data[IFLA_BAREUDP_ETHERTYPE]) {
 616                 NL_SET_ERR_MSG(extack, "ethertype not specified");
 617                 return -EINVAL;
 618         }
 619
 620         conf->port = nla_get_u16(data[IFLA_BAREUDP_PORT]);
 621         conf->ethertype = nla_get_u16(data[IFLA_BAREUDP_ETHERTYPE]);
 622
 623         if (data[IFLA_BAREUDP_SRCPORT_MIN])
 624                 conf->sport_min =  nla_get_u16(data[IFLA_BAREUDP_SRCPORT_MIN]);
 625
 626         if (data[IFLA_BAREUDP_MULTIPROTO_MODE])
 627                 conf->multi_proto_mode = true;
 628
 629         return 0;
 630 }
 631
 632 static struct bareudp_dev *bareudp_find_dev(struct bareudp_net *bn,
 633                                             const struct bareudp_conf *conf)
 634 {
 635         struct bareudp_dev *bareudp, *t = NULL;
 636
 637         list_for_each_entry(bareudp, &bn->bareudp_list, next) {
 638                 if (conf->port == bareudp->port)
 639                         t = bareudp;
 640         }
 641         return t;
 642 }
 643
 644 static int bareudp_configure(struct net *net, struct net_device *dev,
 645                              struct bareudp_conf *conf,
 646                              struct netlink_ext_ack *extack)
 647 {
 648         struct bareudp_net *bn = net_generic(net, bareudp_net_id);
 649         struct bareudp_dev *t, *bareudp = netdev_priv(dev);
 650         int err;
 651
 652         bareudp->net = net;
 653         bareudp->dev = dev;
 654         t = bareudp_find_dev(bn, conf);
 655         if (t) {
 656                 NL_SET_ERR_MSG(extack, "Another bareudp device using the same port already exists");
 657                 return -EBUSY;
 658         }
 659
 660         if (conf->multi_proto_mode &&
 661             (conf->ethertype != htons(ETH_P_MPLS_UC) &&
 662              conf->ethertype != htons(ETH_P_IP))) {
 663                 NL_SET_ERR_MSG(extack, "Cannot set multiproto mode for this ethertype (only IPv4 and unicast MPLS are supported)");
 664                 return -EINVAL;
 665         }
 666
 667         bareudp->port = conf->port;
 668         bareudp->ethertype = conf->ethertype;
 669         bareudp->sport_min = conf->sport_min;
 670         bareudp->multi_proto_mode = conf->multi_proto_mode;
 671
 672         err = register_netdevice(dev);
 673         if (err)
 674                 return err;
 675
 676         list_add(&bareudp->next, &bn->bareudp_list);
 677         return 0;
 678 }
 679
 680 static int bareudp_link_config(struct net_device *dev,
 681                                struct nlattr *tb[])
 682 {
 683         int err;
 684
 685         if (tb[IFLA_MTU]) {
 686                 err = dev_set_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
 687                 if (err)
 688                         return err;
 689         }
 690         return 0;
 691 }
 692
 693 static void bareudp_dellink(struct net_device *dev, struct list_head *head)
 694 {
 695         struct bareudp_dev *bareudp = netdev_priv(dev);
 696
 697         list_del(&bareudp->next);
 698         unregister_netdevice_queue(dev, head);
 699 }
 700
 701 static int bareudp_newlink(struct net *net, struct net_device *dev,
 702                            struct nlattr *tb[], struct nlattr *data[],
 703                            struct netlink_ext_ack *extack)
 704 {
 705         struct bareudp_conf conf;
 706         int err;
 707
 708         err = bareudp2info(data, &conf, extack);
 709         if (err)
 710                 return err;
 711
 712         err = bareudp_configure(net, dev, &conf, extack);
 713         if (err)
 714                 return err;
 715
 716         err = bareudp_link_config(dev, tb);
 717         if (err)
 718                 goto err_unconfig;
 719
 720         return 0;
 721
 722 err_unconfig:
 723         bareudp_dellink(dev, NULL);
 724         return err;
 725 }
 726
 727 static size_t bareudp_get_size(const struct net_device *dev)
 728 {
 729         return  nla_total_size(sizeof(__be16)) +  /* IFLA_BAREUDP_PORT */
 730                 nla_total_size(sizeof(__be16)) +  /* IFLA_BAREUDP_ETHERTYPE */
 731                 nla_total_size(sizeof(__u16))  +  /* IFLA_BAREUDP_SRCPORT_MIN */
 732                 nla_total_size(0)              +  /* IFLA_BAREUDP_MULTIPROTO_MODE */
 733                 0;
 734 }
 735
 736 static int bareudp_fill_info(struct sk_buff *skb, const struct net_device *dev)
 737 {
 738         struct bareudp_dev *bareudp = netdev_priv(dev);
 739
 740         if (nla_put_be16(skb, IFLA_BAREUDP_PORT, bareudp->port))
 741                 goto nla_put_failure;
 742         if (nla_put_be16(skb, IFLA_BAREUDP_ETHERTYPE, bareudp->ethertype))
 743                 goto nla_put_failure;
 744         if (nla_put_u16(skb, IFLA_BAREUDP_SRCPORT_MIN, bareudp->sport_min))
 745                 goto nla_put_failure;
 746         if (bareudp->multi_proto_mode &&
 747             nla_put_flag(skb, IFLA_BAREUDP_MULTIPROTO_MODE))
 748                 goto nla_put_failure;
 749
 750         return 0;
 751
 752 nla_put_failure:
 753         return -EMSGSIZE;
 754 }
 755
 756 static struct rtnl_link_ops bareudp_link_ops __read_mostly = {
 757         .kind           = "bareudp",
 758         .maxtype        = IFLA_BAREUDP_MAX,
 759         .policy         = bareudp_policy,
 760         .priv_size      = sizeof(struct bareudp_dev),
 761         .setup          = bareudp_setup,
 762         .validate       = bareudp_validate,
 763         .newlink        = bareudp_newlink,
 764         .dellink        = bareudp_dellink,
 765         .get_size       = bareudp_get_size,
 766         .fill_info      = bareudp_fill_info,
 767 };
 768
 769 static __net_init int bareudp_init_net(struct net *net)
 770 {
 771         struct bareudp_net *bn = net_generic(net, bareudp_net_id);
 772
 773         INIT_LIST_HEAD(&bn->bareudp_list);
 774         return 0;
 775 }
 776
 777 static void bareudp_destroy_tunnels(struct net *net, struct list_head *head)
 778 {
 779         struct bareudp_net *bn = net_generic(net, bareudp_net_id);
 780         struct bareudp_dev *bareudp, *next;
 781
 782         list_for_each_entry_safe(bareudp, next, &bn->bareudp_list, next)
 783                 unregister_netdevice_queue(bareudp->dev, head);
 784 }
 785
 786 static void __net_exit bareudp_exit_batch_rtnl(struct list_head *net_list,
 787                                                struct list_head *dev_kill_list)
 788 {
 789         struct net *net;
 790
 791         list_for_each_entry(net, net_list, exit_list)
 792                 bareudp_destroy_tunnels(net, dev_kill_list);
 793 }
 794
 795 static struct pernet_operations bareudp_net_ops = {
 796         .init = bareudp_init_net,
 797         .exit_batch_rtnl = bareudp_exit_batch_rtnl,
 798         .id   = &bareudp_net_id,
 799         .size = sizeof(struct bareudp_net),
 800 };
 801
 802 static int __init bareudp_init_module(void)
 803 {
 804         int rc;
 805
 806         rc = register_pernet_subsys(&bareudp_net_ops);
 807         if (rc)
 808                 goto out1;
 809
 810         rc = rtnl_link_register(&bareudp_link_ops);
 811         if (rc)
 812                 goto out2;
 813
 814         return 0;
 815 out2:
 816         unregister_pernet_subsys(&bareudp_net_ops);
 817 out1:
 818         return rc;
 819 }
 820 late_initcall(bareudp_init_module);
 821
 822 static void __exit bareudp_cleanup_module(void)
 823 {
 824         rtnl_link_unregister(&bareudp_link_ops);
 825         unregister_pernet_subsys(&bareudp_net_ops);
 826 }
 827 module_exit(bareudp_cleanup_module);
 828
 829 MODULE_ALIAS_RTNL_LINK("bareudp");
 830 MODULE_LICENSE("GPL");
 831 MODULE_AUTHOR("Martin Varghese <[email protected]>");
 832 MODULE_DESCRIPTION("Interface driver for UDP encapsulated traffic");