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, <martin.varghese@nokia.com>
   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         struct bareudp_dev *bareudp;
  65         unsigned short family;
  66         unsigned int len;
  67         __be16 proto;
  68         void *oiph;
  69         int err;
  70
  71         bareudp = rcu_dereference_sk_user_data(sk);
  72         if (!bareudp)
  73                 goto drop;
  74
  75         if (skb->protocol ==  htons(ETH_P_IP))
  76                 family = AF_INET;
  77         else
  78                 family = AF_INET6;
  79
  80         if (bareudp->ethertype == htons(ETH_P_IP)) {
  81                 __u8 ipversion;
  82
  83                 if (skb_copy_bits(skb, BAREUDP_BASE_HLEN, &ipversion,
  84                                   sizeof(ipversion))) {
  85                         bareudp->dev->stats.rx_dropped++;
  86                         goto drop;
  87                 }
  88                 ipversion >>= 4;
  89
  90                 if (ipversion == 4) {
  91                         proto = htons(ETH_P_IP);
  92                 } else if (ipversion == 6 && bareudp->multi_proto_mode) {
  93                         proto = htons(ETH_P_IPV6);
  94                 } else {
  95                         bareudp->dev->stats.rx_dropped++;
  96                         goto drop;
  97                 }
  98         } else if (bareudp->ethertype == htons(ETH_P_MPLS_UC)) {
  99                 struct iphdr *tunnel_hdr;
 100
 101                 tunnel_hdr = (struct iphdr *)skb_network_header(skb);
 102                 if (tunnel_hdr->version == 4) {
 103                         if (!ipv4_is_multicast(tunnel_hdr->daddr)) {
 104                                 proto = bareudp->ethertype;
 105                         } else if (bareudp->multi_proto_mode &&
 106                                    ipv4_is_multicast(tunnel_hdr->daddr)) {
 107                                 proto = htons(ETH_P_MPLS_MC);
 108                         } else {
 109                                 bareudp->dev->stats.rx_dropped++;
 110                                 goto drop;
 111                         }
 112                 } else {
 113                         int addr_type;
 114                         struct ipv6hdr *tunnel_hdr_v6;
 115
 116                         tunnel_hdr_v6 = (struct ipv6hdr *)skb_network_header(skb);
 117                         addr_type =
 118                         ipv6_addr_type((struct in6_addr *)&tunnel_hdr_v6->daddr);
 119                         if (!(addr_type & IPV6_ADDR_MULTICAST)) {
 120                                 proto = bareudp->ethertype;
 121                         } else if (bareudp->multi_proto_mode &&
 122                                    (addr_type & IPV6_ADDR_MULTICAST)) {
 123                                 proto = htons(ETH_P_MPLS_MC);
 124                         } else {
 125                                 bareudp->dev->stats.rx_dropped++;
 126                                 goto drop;
 127                         }
 128                 }
 129         } else {
 130                 proto = bareudp->ethertype;
 131         }
 132
 133         if (iptunnel_pull_header(skb, BAREUDP_BASE_HLEN,
 134                                  proto,
 135                                  !net_eq(bareudp->net,
 136                                  dev_net(bareudp->dev)))) {
 137                 bareudp->dev->stats.rx_dropped++;
 138                 goto drop;
 139         }
 140         tun_dst = udp_tun_rx_dst(skb, family, TUNNEL_KEY, 0, 0);
 141         if (!tun_dst) {
 142                 bareudp->dev->stats.rx_dropped++;
 143                 goto drop;
 144         }
 145         skb_dst_set(skb, &tun_dst->dst);
 146         skb->dev = bareudp->dev;
 147         oiph = skb_network_header(skb);
 148         skb_reset_network_header(skb);
 149         skb_reset_mac_header(skb);
 150
 151         if (!ipv6_mod_enabled() || family == AF_INET)
 152                 err = IP_ECN_decapsulate(oiph, skb);
 153         else
 154                 err = IP6_ECN_decapsulate(oiph, skb);
 155
 156         if (unlikely(err)) {
 157                 if (log_ecn_error) {
 158                         if  (!ipv6_mod_enabled() || family == AF_INET)
 159                                 net_info_ratelimited("non-ECT from %pI4 "
 160                                                      "with TOS=%#x\n",
 161                                                      &((struct iphdr *)oiph)->saddr,
 162                                                      ((struct iphdr *)oiph)->tos);
 163                         else
 164                                 net_info_ratelimited("non-ECT from %pI6\n",
 165                                                      &((struct ipv6hdr *)oiph)->saddr);
 166                 }
 167                 if (err > 1) {
 168                         ++bareudp->dev->stats.rx_frame_errors;
 169                         ++bareudp->dev->stats.rx_errors;
 170                         goto drop;
 171                 }
 172         }
 173
 174         len = skb->len;
 175         err = gro_cells_receive(&bareudp->gro_cells, skb);
 176         if (likely(err == NET_RX_SUCCESS))
 177                 dev_sw_netstats_rx_add(bareudp->dev, len);
 178
 179         return 0;
 180 drop:
 181         /* Consume bad packet */
 182         kfree_skb(skb);
 183
 184         return 0;
 185 }
 186
 187 static int bareudp_err_lookup(struct sock *sk, struct sk_buff *skb)
 188 {
 189         return 0;
 190 }
 191
 192 static int bareudp_init(struct net_device *dev)
 193 {
 194         struct bareudp_dev *bareudp = netdev_priv(dev);
 195         int err;
 196
 197         dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
 198         if (!dev->tstats)
 199                 return -ENOMEM;
 200
 201         err = gro_cells_init(&bareudp->gro_cells, dev);
 202         if (err) {
 203                 free_percpu(dev->tstats);
 204                 return err;
 205         }
 206         return 0;
 207 }
 208
 209 static void bareudp_uninit(struct net_device *dev)
 210 {
 211         struct bareudp_dev *bareudp = netdev_priv(dev);
 212
 213         gro_cells_destroy(&bareudp->gro_cells);
 214         free_percpu(dev->tstats);
 215 }
 216
 217 static struct socket *bareudp_create_sock(struct net *net, __be16 port)
 218 {
 219         struct udp_port_cfg udp_conf;
 220         struct socket *sock;
 221         int err;
 222
 223         memset(&udp_conf, 0, sizeof(udp_conf));
 224
 225         if (ipv6_mod_enabled())
 226                 udp_conf.family = AF_INET6;
 227         else
 228                 udp_conf.family = AF_INET;
 229
 230         udp_conf.local_udp_port = port;
 231         /* Open UDP socket */
 232         err = udp_sock_create(net, &udp_conf, &sock);
 233         if (err < 0)
 234                 return ERR_PTR(err);
 235
 236         udp_allow_gso(sock->sk);
 237         return sock;
 238 }
 239
 240 /* Create new listen socket if needed */
 241 static int bareudp_socket_create(struct bareudp_dev *bareudp, __be16 port)
 242 {
 243         struct udp_tunnel_sock_cfg tunnel_cfg;
 244         struct socket *sock;
 245
 246         sock = bareudp_create_sock(bareudp->net, port);
 247         if (IS_ERR(sock))
 248                 return PTR_ERR(sock);
 249
 250         /* Mark socket as an encapsulation socket */
 251         memset(&tunnel_cfg, 0, sizeof(tunnel_cfg));
 252         tunnel_cfg.sk_user_data = bareudp;
 253         tunnel_cfg.encap_type = 1;
 254         tunnel_cfg.encap_rcv = bareudp_udp_encap_recv;
 255         tunnel_cfg.encap_err_lookup = bareudp_err_lookup;
 256         tunnel_cfg.encap_destroy = NULL;
 257         setup_udp_tunnel_sock(bareudp->net, sock, &tunnel_cfg);
 258
 259         rcu_assign_pointer(bareudp->sock, sock);
 260         return 0;
 261 }
 262
 263 static int bareudp_open(struct net_device *dev)
 264 {
 265         struct bareudp_dev *bareudp = netdev_priv(dev);
 266         int ret = 0;
 267
 268         ret =  bareudp_socket_create(bareudp, bareudp->port);
 269         return ret;
 270 }
 271
 272 static void bareudp_sock_release(struct bareudp_dev *bareudp)
 273 {
 274         struct socket *sock;
 275
 276         sock = bareudp->sock;
 277         rcu_assign_pointer(bareudp->sock, NULL);
 278         synchronize_net();
 279         udp_tunnel_sock_release(sock);
 280 }
 281
 282 static int bareudp_stop(struct net_device *dev)
 283 {
 284         struct bareudp_dev *bareudp = netdev_priv(dev);
 285
 286         bareudp_sock_release(bareudp);
 287         return 0;
 288 }
 289
 290 static int bareudp_xmit_skb(struct sk_buff *skb, struct net_device *dev,
 291                             struct bareudp_dev *bareudp,
 292                             const struct ip_tunnel_info *info)
 293 {
 294         bool xnet = !net_eq(bareudp->net, dev_net(bareudp->dev));
 295         bool use_cache = ip_tunnel_dst_cache_usable(skb, info);
 296         struct socket *sock = rcu_dereference(bareudp->sock);
 297         bool udp_sum = !!(info->key.tun_flags & TUNNEL_CSUM);
 298         const struct ip_tunnel_key *key = &info->key;
 299         struct rtable *rt;
 300         __be16 sport, df;
 301         int min_headroom;
 302         __u8 tos, ttl;
 303         __be32 saddr;
 304         int err;
 305
 306         if (!sock)
 307                 return -ESHUTDOWN;
 308
 309         sport = udp_flow_src_port(bareudp->net, skb,
 310                                   bareudp->sport_min, USHRT_MAX,
 311                                   true);
 312         rt = udp_tunnel_dst_lookup(skb, dev, bareudp->net, 0, &saddr, &info->key,
 313                                    sport, bareudp->port, key->tos,
 314                                    use_cache ?
 315                                    (struct dst_cache *)&info->dst_cache : NULL);
 316
 317         if (IS_ERR(rt))
 318                 return PTR_ERR(rt);
 319
 320         skb_tunnel_check_pmtu(skb, &rt->dst,
 321                               BAREUDP_IPV4_HLEN + info->options_len, false);
 322
 323         tos = ip_tunnel_ecn_encap(key->tos, ip_hdr(skb), skb);
 324         ttl = key->ttl;
 325         df = key->tun_flags & TUNNEL_DONT_FRAGMENT ? htons(IP_DF) : 0;
 326         skb_scrub_packet(skb, xnet);
 327
 328         err = -ENOSPC;
 329         if (!skb_pull(skb, skb_network_offset(skb)))
 330                 goto free_dst;
 331
 332         min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len +
 333                 BAREUDP_BASE_HLEN + info->options_len + sizeof(struct iphdr);
 334
 335         err = skb_cow_head(skb, min_headroom);
 336         if (unlikely(err))
 337                 goto free_dst;
 338
 339         err = udp_tunnel_handle_offloads(skb, udp_sum);
 340         if (err)
 341                 goto free_dst;
 342
 343         skb_set_inner_protocol(skb, bareudp->ethertype);
 344         udp_tunnel_xmit_skb(rt, sock->sk, skb, saddr, info->key.u.ipv4.dst,
 345                             tos, ttl, df, sport, bareudp->port,
 346                             !net_eq(bareudp->net, dev_net(bareudp->dev)),
 347                             !(info->key.tun_flags & TUNNEL_CSUM));
 348         return 0;
 349
 350 free_dst:
 351         dst_release(&rt->dst);
 352         return err;
 353 }
 354
 355 static int bareudp6_xmit_skb(struct sk_buff *skb, struct net_device *dev,
 356                              struct bareudp_dev *bareudp,
 357                              const struct ip_tunnel_info *info)
 358 {
 359         bool xnet = !net_eq(bareudp->net, dev_net(bareudp->dev));
 360         bool use_cache = ip_tunnel_dst_cache_usable(skb, info);
 361         struct socket *sock  = rcu_dereference(bareudp->sock);
 362         bool udp_sum = !!(info->key.tun_flags & TUNNEL_CSUM);
 363         const struct ip_tunnel_key *key = &info->key;
 364         struct dst_entry *dst = NULL;
 365         struct in6_addr saddr, daddr;
 366         int min_headroom;
 367         __u8 prio, ttl;
 368         __be16 sport;
 369         int err;
 370
 371         if (!sock)
 372                 return -ESHUTDOWN;
 373
 374         sport = udp_flow_src_port(bareudp->net, skb,
 375                                   bareudp->sport_min, USHRT_MAX,
 376                                   true);
 377         dst = udp_tunnel6_dst_lookup(skb, dev, bareudp->net, sock, 0, &saddr,
 378                                      key, sport, bareudp->port, key->tos,
 379                                      use_cache ?
 380                                      (struct dst_cache *) &info->dst_cache : NULL);
 381         if (IS_ERR(dst))
 382                 return PTR_ERR(dst);
 383
 384         skb_tunnel_check_pmtu(skb, dst, BAREUDP_IPV6_HLEN + info->options_len,
 385                               false);
 386
 387         prio = ip_tunnel_ecn_encap(key->tos, ip_hdr(skb), skb);
 388         ttl = key->ttl;
 389
 390         skb_scrub_packet(skb, xnet);
 391
 392         err = -ENOSPC;
 393         if (!skb_pull(skb, skb_network_offset(skb)))
 394                 goto free_dst;
 395
 396         min_headroom = LL_RESERVED_SPACE(dst->dev) + dst->header_len +
 397                 BAREUDP_BASE_HLEN + info->options_len + sizeof(struct ipv6hdr);
 398
 399         err = skb_cow_head(skb, min_headroom);
 400         if (unlikely(err))
 401                 goto free_dst;
 402
 403         err = udp_tunnel_handle_offloads(skb, udp_sum);
 404         if (err)
 405                 goto free_dst;
 406
 407         daddr = info->key.u.ipv6.dst;
 408         udp_tunnel6_xmit_skb(dst, sock->sk, skb, dev,
 409                              &saddr, &daddr, prio, ttl,
 410                              info->key.label, sport, bareudp->port,
 411                              !(info->key.tun_flags & TUNNEL_CSUM));
 412         return 0;
 413
 414 free_dst:
 415         dst_release(dst);
 416         return err;
 417 }
 418
 419 static bool bareudp_proto_valid(struct bareudp_dev *bareudp, __be16 proto)
 420 {
 421         if (bareudp->ethertype == proto)
 422                 return true;
 423
 424         if (!bareudp->multi_proto_mode)
 425                 return false;
 426
 427         if (bareudp->ethertype == htons(ETH_P_MPLS_UC) &&
 428             proto == htons(ETH_P_MPLS_MC))
 429                 return true;
 430
 431         if (bareudp->ethertype == htons(ETH_P_IP) &&
 432             proto == htons(ETH_P_IPV6))
 433                 return true;
 434
 435         return false;
 436 }
 437
 438 static netdev_tx_t bareudp_xmit(struct sk_buff *skb, struct net_device *dev)
 439 {
 440         struct bareudp_dev *bareudp = netdev_priv(dev);
 441         struct ip_tunnel_info *info = NULL;
 442         int err;
 443
 444         if (!bareudp_proto_valid(bareudp, skb->protocol)) {
 445                 err = -EINVAL;
 446                 goto tx_error;
 447         }
 448
 449         info = skb_tunnel_info(skb);
 450         if (unlikely(!info || !(info->mode & IP_TUNNEL_INFO_TX))) {
 451                 err = -EINVAL;
 452                 goto tx_error;
 453         }
 454
 455         rcu_read_lock();
 456         if (ipv6_mod_enabled() && info->mode & IP_TUNNEL_INFO_IPV6)
 457                 err = bareudp6_xmit_skb(skb, dev, bareudp, info);
 458         else
 459                 err = bareudp_xmit_skb(skb, dev, bareudp, info);
 460
 461         rcu_read_unlock();
 462
 463         if (likely(!err))
 464                 return NETDEV_TX_OK;
 465 tx_error:
 466         dev_kfree_skb(skb);
 467
 468         if (err == -ELOOP)
 469                 dev->stats.collisions++;
 470         else if (err == -ENETUNREACH)
 471                 dev->stats.tx_carrier_errors++;
 472
 473         dev->stats.tx_errors++;
 474         return NETDEV_TX_OK;
 475 }
 476
 477 static int bareudp_fill_metadata_dst(struct net_device *dev,
 478                                      struct sk_buff *skb)
 479 {
 480         struct ip_tunnel_info *info = skb_tunnel_info(skb);
 481         struct bareudp_dev *bareudp = netdev_priv(dev);
 482         bool use_cache;
 483         __be16 sport;
 484
 485         use_cache = ip_tunnel_dst_cache_usable(skb, info);
 486         sport = udp_flow_src_port(bareudp->net, skb,
 487                                   bareudp->sport_min, USHRT_MAX,
 488                                   true);
 489
 490         if (!ipv6_mod_enabled() || ip_tunnel_info_af(info) == AF_INET) {
 491                 struct rtable *rt;
 492                 __be32 saddr;
 493
 494                 rt = udp_tunnel_dst_lookup(skb, dev, bareudp->net, 0, &saddr,
 495                                            &info->key, sport, bareudp->port,
 496                                            info->key.tos,
 497                                            use_cache ? &info->dst_cache : NULL);
 498                 if (IS_ERR(rt))
 499                         return PTR_ERR(rt);
 500
 501                 ip_rt_put(rt);
 502                 info->key.u.ipv4.src = saddr;
 503         } else if (ip_tunnel_info_af(info) == AF_INET6) {
 504                 struct dst_entry *dst;
 505                 struct in6_addr saddr;
 506                 struct socket *sock = rcu_dereference(bareudp->sock);
 507
 508                 dst = udp_tunnel6_dst_lookup(skb, dev, bareudp->net, sock,
 509                                              0, &saddr, &info->key,
 510                                              sport, bareudp->port, info->key.tos,
 511                                              use_cache ? &info->dst_cache : NULL);
 512                 if (IS_ERR(dst))
 513                         return PTR_ERR(dst);
 514
 515                 dst_release(dst);
 516                 info->key.u.ipv6.src = saddr;
 517         } else {
 518                 return -EINVAL;
 519         }
 520
 521         info->key.tp_src = sport;
 522         info->key.tp_dst = bareudp->port;
 523         return 0;
 524 }
 525
 526 static const struct net_device_ops bareudp_netdev_ops = {
 527         .ndo_init               = bareudp_init,
 528         .ndo_uninit             = bareudp_uninit,
 529         .ndo_open               = bareudp_open,
 530         .ndo_stop               = bareudp_stop,
 531         .ndo_start_xmit         = bareudp_xmit,
 532         .ndo_get_stats64        = dev_get_tstats64,
 533         .ndo_fill_metadata_dst  = bareudp_fill_metadata_dst,
 534 };
 535
 536 static const struct nla_policy bareudp_policy[IFLA_BAREUDP_MAX + 1] = {
 537         [IFLA_BAREUDP_PORT]                = { .type = NLA_U16 },
 538         [IFLA_BAREUDP_ETHERTYPE]           = { .type = NLA_U16 },
 539         [IFLA_BAREUDP_SRCPORT_MIN]         = { .type = NLA_U16 },
 540         [IFLA_BAREUDP_MULTIPROTO_MODE]     = { .type = NLA_FLAG },
 541 };
 542
 543 /* Info for udev, that this is a virtual tunnel endpoint */
 544 static const struct device_type bareudp_type = {
 545         .name = "bareudp",
 546 };
 547
 548 /* Initialize the device structure. */
 549 static void bareudp_setup(struct net_device *dev)
 550 {
 551         dev->netdev_ops = &bareudp_netdev_ops;
 552         dev->needs_free_netdev = true;
 553         SET_NETDEV_DEVTYPE(dev, &bareudp_type);
 554         dev->features    |= NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_FRAGLIST;
 555         dev->features    |= NETIF_F_RXCSUM;
 556         dev->features    |= NETIF_F_LLTX;
 557         dev->features    |= NETIF_F_GSO_SOFTWARE;
 558         dev->hw_features |= NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_FRAGLIST;
 559         dev->hw_features |= NETIF_F_RXCSUM;
 560         dev->hw_features |= NETIF_F_GSO_SOFTWARE;
 561         dev->hard_header_len = 0;
 562         dev->addr_len = 0;
 563         dev->mtu = ETH_DATA_LEN;
 564         dev->min_mtu = IPV4_MIN_MTU;
 565         dev->max_mtu = IP_MAX_MTU - BAREUDP_BASE_HLEN;
 566         dev->type = ARPHRD_NONE;
 567         netif_keep_dst(dev);
 568         dev->priv_flags |= IFF_NO_QUEUE;
 569         dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
 570 }
 571
 572 static int bareudp_validate(struct nlattr *tb[], struct nlattr *data[],
 573                             struct netlink_ext_ack *extack)
 574 {
 575         if (!data) {
 576                 NL_SET_ERR_MSG(extack,
 577                                "Not enough attributes provided to perform the operation");
 578                 return -EINVAL;
 579         }
 580         return 0;
 581 }
 582
 583 static int bareudp2info(struct nlattr *data[], struct bareudp_conf *conf,
 584                         struct netlink_ext_ack *extack)
 585 {
 586         memset(conf, 0, sizeof(*conf));
 587
 588         if (!data[IFLA_BAREUDP_PORT]) {
 589                 NL_SET_ERR_MSG(extack, "port not specified");
 590                 return -EINVAL;
 591         }
 592         if (!data[IFLA_BAREUDP_ETHERTYPE]) {
 593                 NL_SET_ERR_MSG(extack, "ethertype not specified");
 594                 return -EINVAL;
 595         }
 596
 597         conf->port = nla_get_u16(data[IFLA_BAREUDP_PORT]);
 598         conf->ethertype = nla_get_u16(data[IFLA_BAREUDP_ETHERTYPE]);
 599
 600         if (data[IFLA_BAREUDP_SRCPORT_MIN])
 601                 conf->sport_min =  nla_get_u16(data[IFLA_BAREUDP_SRCPORT_MIN]);
 602
 603         if (data[IFLA_BAREUDP_MULTIPROTO_MODE])
 604                 conf->multi_proto_mode = true;
 605
 606         return 0;
 607 }
 608
 609 static struct bareudp_dev *bareudp_find_dev(struct bareudp_net *bn,
 610                                             const struct bareudp_conf *conf)
 611 {
 612         struct bareudp_dev *bareudp, *t = NULL;
 613
 614         list_for_each_entry(bareudp, &bn->bareudp_list, next) {
 615                 if (conf->port == bareudp->port)
 616                         t = bareudp;
 617         }
 618         return t;
 619 }
 620
 621 static int bareudp_configure(struct net *net, struct net_device *dev,
 622                              struct bareudp_conf *conf,
 623                              struct netlink_ext_ack *extack)
 624 {
 625         struct bareudp_net *bn = net_generic(net, bareudp_net_id);
 626         struct bareudp_dev *t, *bareudp = netdev_priv(dev);
 627         int err;
 628
 629         bareudp->net = net;
 630         bareudp->dev = dev;
 631         t = bareudp_find_dev(bn, conf);
 632         if (t) {
 633                 NL_SET_ERR_MSG(extack, "Another bareudp device using the same port already exists");
 634                 return -EBUSY;
 635         }
 636
 637         if (conf->multi_proto_mode &&
 638             (conf->ethertype != htons(ETH_P_MPLS_UC) &&
 639              conf->ethertype != htons(ETH_P_IP))) {
 640                 NL_SET_ERR_MSG(extack, "Cannot set multiproto mode for this ethertype (only IPv4 and unicast MPLS are supported)");
 641                 return -EINVAL;
 642         }
 643
 644         bareudp->port = conf->port;
 645         bareudp->ethertype = conf->ethertype;
 646         bareudp->sport_min = conf->sport_min;
 647         bareudp->multi_proto_mode = conf->multi_proto_mode;
 648
 649         err = register_netdevice(dev);
 650         if (err)
 651                 return err;
 652
 653         list_add(&bareudp->next, &bn->bareudp_list);
 654         return 0;
 655 }
 656
 657 static int bareudp_link_config(struct net_device *dev,
 658                                struct nlattr *tb[])
 659 {
 660         int err;
 661
 662         if (tb[IFLA_MTU]) {
 663                 err = dev_set_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
 664                 if (err)
 665                         return err;
 666         }
 667         return 0;
 668 }
 669
 670 static void bareudp_dellink(struct net_device *dev, struct list_head *head)
 671 {
 672         struct bareudp_dev *bareudp = netdev_priv(dev);
 673
 674         list_del(&bareudp->next);
 675         unregister_netdevice_queue(dev, head);
 676 }
 677
 678 static int bareudp_newlink(struct net *net, struct net_device *dev,
 679                            struct nlattr *tb[], struct nlattr *data[],
 680                            struct netlink_ext_ack *extack)
 681 {
 682         struct bareudp_conf conf;
 683         int err;
 684
 685         err = bareudp2info(data, &conf, extack);
 686         if (err)
 687                 return err;
 688
 689         err = bareudp_configure(net, dev, &conf, extack);
 690         if (err)
 691                 return err;
 692
 693         err = bareudp_link_config(dev, tb);
 694         if (err)
 695                 goto err_unconfig;
 696
 697         return 0;
 698
 699 err_unconfig:
 700         bareudp_dellink(dev, NULL);
 701         return err;
 702 }
 703
 704 static size_t bareudp_get_size(const struct net_device *dev)
 705 {
 706         return  nla_total_size(sizeof(__be16)) +  /* IFLA_BAREUDP_PORT */
 707                 nla_total_size(sizeof(__be16)) +  /* IFLA_BAREUDP_ETHERTYPE */
 708                 nla_total_size(sizeof(__u16))  +  /* IFLA_BAREUDP_SRCPORT_MIN */
 709                 nla_total_size(0)              +  /* IFLA_BAREUDP_MULTIPROTO_MODE */
 710                 0;
 711 }
 712
 713 static int bareudp_fill_info(struct sk_buff *skb, const struct net_device *dev)
 714 {
 715         struct bareudp_dev *bareudp = netdev_priv(dev);
 716
 717         if (nla_put_be16(skb, IFLA_BAREUDP_PORT, bareudp->port))
 718                 goto nla_put_failure;
 719         if (nla_put_be16(skb, IFLA_BAREUDP_ETHERTYPE, bareudp->ethertype))
 720                 goto nla_put_failure;
 721         if (nla_put_u16(skb, IFLA_BAREUDP_SRCPORT_MIN, bareudp->sport_min))
 722                 goto nla_put_failure;
 723         if (bareudp->multi_proto_mode &&
 724             nla_put_flag(skb, IFLA_BAREUDP_MULTIPROTO_MODE))
 725                 goto nla_put_failure;
 726
 727         return 0;
 728
 729 nla_put_failure:
 730         return -EMSGSIZE;
 731 }
 732
 733 static struct rtnl_link_ops bareudp_link_ops __read_mostly = {
 734         .kind           = "bareudp",
 735         .maxtype        = IFLA_BAREUDP_MAX,
 736         .policy         = bareudp_policy,
 737         .priv_size      = sizeof(struct bareudp_dev),
 738         .setup          = bareudp_setup,
 739         .validate       = bareudp_validate,
 740         .newlink        = bareudp_newlink,
 741         .dellink        = bareudp_dellink,
 742         .get_size       = bareudp_get_size,
 743         .fill_info      = bareudp_fill_info,
 744 };
 745
 746 static __net_init int bareudp_init_net(struct net *net)
 747 {
 748         struct bareudp_net *bn = net_generic(net, bareudp_net_id);
 749
 750         INIT_LIST_HEAD(&bn->bareudp_list);
 751         return 0;
 752 }
 753
 754 static void bareudp_destroy_tunnels(struct net *net, struct list_head *head)
 755 {
 756         struct bareudp_net *bn = net_generic(net, bareudp_net_id);
 757         struct bareudp_dev *bareudp, *next;
 758
 759         list_for_each_entry_safe(bareudp, next, &bn->bareudp_list, next)
 760                 unregister_netdevice_queue(bareudp->dev, head);
 761 }
 762
 763 static void __net_exit bareudp_exit_batch_net(struct list_head *net_list)
 764 {
 765         struct net *net;
 766         LIST_HEAD(list);
 767
 768         rtnl_lock();
 769         list_for_each_entry(net, net_list, exit_list)
 770                 bareudp_destroy_tunnels(net, &list);
 771
 772         /* unregister the devices gathered above */
 773         unregister_netdevice_many(&list);
 774         rtnl_unlock();
 775 }
 776
 777 static struct pernet_operations bareudp_net_ops = {
 778         .init = bareudp_init_net,
 779         .exit_batch = bareudp_exit_batch_net,
 780         .id   = &bareudp_net_id,
 781         .size = sizeof(struct bareudp_net),
 782 };
 783
 784 static int __init bareudp_init_module(void)
 785 {
 786         int rc;
 787
 788         rc = register_pernet_subsys(&bareudp_net_ops);
 789         if (rc)
 790                 goto out1;
 791
 792         rc = rtnl_link_register(&bareudp_link_ops);
 793         if (rc)
 794                 goto out2;
 795
 796         return 0;
 797 out2:
 798         unregister_pernet_subsys(&bareudp_net_ops);
 799 out1:
 800         return rc;
 801 }
 802 late_initcall(bareudp_init_module);
 803
 804 static void __exit bareudp_cleanup_module(void)
 805 {
 806         rtnl_link_unregister(&bareudp_link_ops);
 807         unregister_pernet_subsys(&bareudp_net_ops);
 808 }
 809 module_exit(bareudp_cleanup_module);
 810
 811 MODULE_ALIAS_RTNL_LINK("bareudp");
 812 MODULE_LICENSE("GPL");
 813 MODULE_AUTHOR("Martin Varghese <martin.varghese@nokia.com>");
 814 MODULE_DESCRIPTION("Interface driver for UDP encapsulated traffic");