drivers/net/vrf.c

   1 /*
   2  * vrf.c: device driver to encapsulate a VRF space
   3  *
   4  * Copyright (c) 2015 Cumulus Networks. All rights reserved.
   5  * Copyright (c) 2015 Shrijeet Mukherjee <shm@cumulusnetworks.com>
   6  * Copyright (c) 2015 David Ahern <dsa@cumulusnetworks.com>
   7  *
   8  * Based on dummy, team and ipvlan drivers
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  */
  15
  16 #include <linux/module.h>
  17 #include <linux/kernel.h>
  18 #include <linux/netdevice.h>
  19 #include <linux/etherdevice.h>
  20 #include <linux/ip.h>
  21 #include <linux/init.h>
  22 #include <linux/moduleparam.h>
  23 #include <linux/netfilter.h>
  24 #include <linux/rtnetlink.h>
  25 #include <net/rtnetlink.h>
  26 #include <linux/u64_stats_sync.h>
  27 #include <linux/hashtable.h>
  28
  29 #include <linux/inetdevice.h>
  30 #include <net/arp.h>
  31 #include <net/ip.h>
  32 #include <net/ip_fib.h>
  33 #include <net/ip6_fib.h>
  34 #include <net/ip6_route.h>
  35 #include <net/rtnetlink.h>
  36 #include <net/route.h>
  37 #include <net/addrconf.h>
  38 #include <net/l3mdev.h>
  39
  40 #define RT_FL_TOS(oldflp4) \
  41         ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
  42
  43 #define DRV_NAME        "vrf"
  44 #define DRV_VERSION     "1.0"
  45
  46 #define vrf_master_get_rcu(dev) \
  47         ((struct net_device *)rcu_dereference(dev->rx_handler_data))
  48
  49 struct net_vrf {
  50         struct rtable           *rth;
  51         struct rt6_info         *rt6;
  52         u32                     tb_id;
  53 };
  54
  55 struct pcpu_dstats {
  56         u64                     tx_pkts;
  57         u64                     tx_bytes;
  58         u64                     tx_drps;
  59         u64                     rx_pkts;
  60         u64                     rx_bytes;
  61         struct u64_stats_sync   syncp;
  62 };
  63
  64 static struct dst_entry *vrf_ip_check(struct dst_entry *dst, u32 cookie)
  65 {
  66         return dst;
  67 }
  68
  69 static int vrf_ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb)
  70 {
  71         return ip_local_out(net, sk, skb);
  72 }
  73
  74 static unsigned int vrf_v4_mtu(const struct dst_entry *dst)
  75 {
  76         /* TO-DO: return max ethernet size? */
  77         return dst->dev->mtu;
  78 }
  79
  80 static void vrf_dst_destroy(struct dst_entry *dst)
  81 {
  82         /* our dst lives forever - or until the device is closed */
  83 }
  84
  85 static unsigned int vrf_default_advmss(const struct dst_entry *dst)
  86 {
  87         return 65535 - 40;
  88 }
  89
  90 static struct dst_ops vrf_dst_ops = {
  91         .family         = AF_INET,
  92         .local_out      = vrf_ip_local_out,
  93         .check          = vrf_ip_check,
  94         .mtu            = vrf_v4_mtu,
  95         .destroy        = vrf_dst_destroy,
  96         .default_advmss = vrf_default_advmss,
  97 };
  98
  99 /* neighbor handling is done with actual device; do not want
 100  * to flip skb->dev for those ndisc packets. This really fails
 101  * for multiple next protocols (e.g., NEXTHDR_HOP). But it is
 102  * a start.
 103  */
 104 #if IS_ENABLED(CONFIG_IPV6)
 105 static bool check_ipv6_frame(const struct sk_buff *skb)
 106 {
 107         const struct ipv6hdr *ipv6h = (struct ipv6hdr *)skb->data;
 108         size_t hlen = sizeof(*ipv6h);
 109         bool rc = true;
 110
 111         if (skb->len < hlen)
 112                 goto out;
 113
 114         if (ipv6h->nexthdr == NEXTHDR_ICMP) {
 115                 const struct icmp6hdr *icmph;
 116
 117                 if (skb->len < hlen + sizeof(*icmph))
 118                         goto out;
 119
 120                 icmph = (struct icmp6hdr *)(skb->data + sizeof(*ipv6h));
 121                 switch (icmph->icmp6_type) {
 122                 case NDISC_ROUTER_SOLICITATION:
 123                 case NDISC_ROUTER_ADVERTISEMENT:
 124                 case NDISC_NEIGHBOUR_SOLICITATION:
 125                 case NDISC_NEIGHBOUR_ADVERTISEMENT:
 126                 case NDISC_REDIRECT:
 127                         rc = false;
 128                         break;
 129                 }
 130         }
 131
 132 out:
 133         return rc;
 134 }
 135 #else
 136 static bool check_ipv6_frame(const struct sk_buff *skb)
 137 {
 138         return false;
 139 }
 140 #endif
 141
 142 static bool is_ip_rx_frame(struct sk_buff *skb)
 143 {
 144         switch (skb->protocol) {
 145         case htons(ETH_P_IP):
 146                 return true;
 147         case htons(ETH_P_IPV6):
 148                 return check_ipv6_frame(skb);
 149         }
 150         return false;
 151 }
 152
 153 static void vrf_tx_error(struct net_device *vrf_dev, struct sk_buff *skb)
 154 {
 155         vrf_dev->stats.tx_errors++;
 156         kfree_skb(skb);
 157 }
 158
 159 /* note: already called with rcu_read_lock */
 160 static rx_handler_result_t vrf_handle_frame(struct sk_buff **pskb)
 161 {
 162         struct sk_buff *skb = *pskb;
 163
 164         if (is_ip_rx_frame(skb)) {
 165                 struct net_device *dev = vrf_master_get_rcu(skb->dev);
 166                 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
 167
 168                 u64_stats_update_begin(&dstats->syncp);
 169                 dstats->rx_pkts++;
 170                 dstats->rx_bytes += skb->len;
 171                 u64_stats_update_end(&dstats->syncp);
 172
 173                 skb->dev = dev;
 174
 175                 return RX_HANDLER_ANOTHER;
 176         }
 177         return RX_HANDLER_PASS;
 178 }
 179
 180 static struct rtnl_link_stats64 *vrf_get_stats64(struct net_device *dev,
 181                                                  struct rtnl_link_stats64 *stats)
 182 {
 183         int i;
 184
 185         for_each_possible_cpu(i) {
 186                 const struct pcpu_dstats *dstats;
 187                 u64 tbytes, tpkts, tdrops, rbytes, rpkts;
 188                 unsigned int start;
 189
 190                 dstats = per_cpu_ptr(dev->dstats, i);
 191                 do {
 192                         start = u64_stats_fetch_begin_irq(&dstats->syncp);
 193                         tbytes = dstats->tx_bytes;
 194                         tpkts = dstats->tx_pkts;
 195                         tdrops = dstats->tx_drps;
 196                         rbytes = dstats->rx_bytes;
 197                         rpkts = dstats->rx_pkts;
 198                 } while (u64_stats_fetch_retry_irq(&dstats->syncp, start));
 199                 stats->tx_bytes += tbytes;
 200                 stats->tx_packets += tpkts;
 201                 stats->tx_dropped += tdrops;
 202                 stats->rx_bytes += rbytes;
 203                 stats->rx_packets += rpkts;
 204         }
 205         return stats;
 206 }
 207
 208 #if IS_ENABLED(CONFIG_IPV6)
 209 static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
 210                                            struct net_device *dev)
 211 {
 212         const struct ipv6hdr *iph = ipv6_hdr(skb);
 213         struct net *net = dev_net(skb->dev);
 214         struct flowi6 fl6 = {
 215                 /* needed to match OIF rule */
 216                 .flowi6_oif = dev->ifindex,
 217                 .flowi6_iif = LOOPBACK_IFINDEX,
 218                 .daddr = iph->daddr,
 219                 .saddr = iph->saddr,
 220                 .flowlabel = ip6_flowinfo(iph),
 221                 .flowi6_mark = skb->mark,
 222                 .flowi6_proto = iph->nexthdr,
 223                 .flowi6_flags = FLOWI_FLAG_L3MDEV_SRC | FLOWI_FLAG_SKIP_NH_OIF,
 224         };
 225         int ret = NET_XMIT_DROP;
 226         struct dst_entry *dst;
 227         struct dst_entry *dst_null = &net->ipv6.ip6_null_entry->dst;
 228
 229         dst = ip6_route_output(net, NULL, &fl6);
 230         if (dst == dst_null)
 231                 goto err;
 232
 233         skb_dst_drop(skb);
 234         skb_dst_set(skb, dst);
 235
 236         ret = ip6_local_out(net, skb->sk, skb);
 237         if (unlikely(net_xmit_eval(ret)))
 238                 dev->stats.tx_errors++;
 239         else
 240                 ret = NET_XMIT_SUCCESS;
 241
 242         return ret;
 243 err:
 244         vrf_tx_error(dev, skb);
 245         return NET_XMIT_DROP;
 246 }
 247 #else
 248 static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
 249                                            struct net_device *dev)
 250 {
 251         vrf_tx_error(dev, skb);
 252         return NET_XMIT_DROP;
 253 }
 254 #endif
 255
 256 static int vrf_send_v4_prep(struct sk_buff *skb, struct flowi4 *fl4,
 257                             struct net_device *vrf_dev)
 258 {
 259         struct rtable *rt;
 260         int err = 1;
 261
 262         rt = ip_route_output_flow(dev_net(vrf_dev), fl4, NULL);
 263         if (IS_ERR(rt))
 264                 goto out;
 265
 266         /* TO-DO: what about broadcast ? */
 267         if (rt->rt_type != RTN_UNICAST && rt->rt_type != RTN_LOCAL) {
 268                 ip_rt_put(rt);
 269                 goto out;
 270         }
 271
 272         skb_dst_drop(skb);
 273         skb_dst_set(skb, &rt->dst);
 274         err = 0;
 275 out:
 276         return err;
 277 }
 278
 279 static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb,
 280                                            struct net_device *vrf_dev)
 281 {
 282         struct iphdr *ip4h = ip_hdr(skb);
 283         int ret = NET_XMIT_DROP;
 284         struct flowi4 fl4 = {
 285                 /* needed to match OIF rule */
 286                 .flowi4_oif = vrf_dev->ifindex,
 287                 .flowi4_iif = LOOPBACK_IFINDEX,
 288                 .flowi4_tos = RT_TOS(ip4h->tos),
 289                 .flowi4_flags = FLOWI_FLAG_ANYSRC | FLOWI_FLAG_L3MDEV_SRC |
 290                                 FLOWI_FLAG_SKIP_NH_OIF,
 291                 .daddr = ip4h->daddr,
 292         };
 293
 294         if (vrf_send_v4_prep(skb, &fl4, vrf_dev))
 295                 goto err;
 296
 297         if (!ip4h->saddr) {
 298                 ip4h->saddr = inet_select_addr(skb_dst(skb)->dev, 0,
 299                                                RT_SCOPE_LINK);
 300         }
 301
 302         ret = ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
 303         if (unlikely(net_xmit_eval(ret)))
 304                 vrf_dev->stats.tx_errors++;
 305         else
 306                 ret = NET_XMIT_SUCCESS;
 307
 308 out:
 309         return ret;
 310 err:
 311         vrf_tx_error(vrf_dev, skb);
 312         goto out;
 313 }
 314
 315 static netdev_tx_t is_ip_tx_frame(struct sk_buff *skb, struct net_device *dev)
 316 {
 317         /* strip the ethernet header added for pass through VRF device */
 318         __skb_pull(skb, skb_network_offset(skb));
 319
 320         switch (skb->protocol) {
 321         case htons(ETH_P_IP):
 322                 return vrf_process_v4_outbound(skb, dev);
 323         case htons(ETH_P_IPV6):
 324                 return vrf_process_v6_outbound(skb, dev);
 325         default:
 326                 vrf_tx_error(dev, skb);
 327                 return NET_XMIT_DROP;
 328         }
 329 }
 330
 331 static netdev_tx_t vrf_xmit(struct sk_buff *skb, struct net_device *dev)
 332 {
 333         netdev_tx_t ret = is_ip_tx_frame(skb, dev);
 334
 335         if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) {
 336                 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
 337
 338                 u64_stats_update_begin(&dstats->syncp);
 339                 dstats->tx_pkts++;
 340                 dstats->tx_bytes += skb->len;
 341                 u64_stats_update_end(&dstats->syncp);
 342         } else {
 343                 this_cpu_inc(dev->dstats->tx_drps);
 344         }
 345
 346         return ret;
 347 }
 348
 349 #if IS_ENABLED(CONFIG_IPV6)
 350 static struct dst_entry *vrf_ip6_check(struct dst_entry *dst, u32 cookie)
 351 {
 352         return dst;
 353 }
 354
 355 static struct dst_ops vrf_dst_ops6 = {
 356         .family         = AF_INET6,
 357         .local_out      = ip6_local_out,
 358         .check          = vrf_ip6_check,
 359         .mtu            = vrf_v4_mtu,
 360         .destroy        = vrf_dst_destroy,
 361         .default_advmss = vrf_default_advmss,
 362 };
 363
 364 static int init_dst_ops6_kmem_cachep(void)
 365 {
 366         vrf_dst_ops6.kmem_cachep = kmem_cache_create("vrf_ip6_dst_cache",
 367                                                      sizeof(struct rt6_info),
 368                                                      0,
 369                                                      SLAB_HWCACHE_ALIGN,
 370                                                      NULL);
 371
 372         if (!vrf_dst_ops6.kmem_cachep)
 373                 return -ENOMEM;
 374
 375         return 0;
 376 }
 377
 378 static void free_dst_ops6_kmem_cachep(void)
 379 {
 380         kmem_cache_destroy(vrf_dst_ops6.kmem_cachep);
 381 }
 382
 383 static int vrf_input6(struct sk_buff *skb)
 384 {
 385         skb->dev->stats.rx_errors++;
 386         kfree_skb(skb);
 387         return 0;
 388 }
 389
 390 /* modelled after ip6_finish_output2 */
 391 static int vrf_finish_output6(struct net *net, struct sock *sk,
 392                               struct sk_buff *skb)
 393 {
 394         struct dst_entry *dst = skb_dst(skb);
 395         struct net_device *dev = dst->dev;
 396         struct neighbour *neigh;
 397         struct in6_addr *nexthop;
 398         int ret;
 399
 400         skb->protocol = htons(ETH_P_IPV6);
 401         skb->dev = dev;
 402
 403         rcu_read_lock_bh();
 404         nexthop = rt6_nexthop((struct rt6_info *)dst, &ipv6_hdr(skb)->daddr);
 405         neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop);
 406         if (unlikely(!neigh))
 407                 neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false);
 408         if (!IS_ERR(neigh)) {
 409                 ret = dst_neigh_output(dst, neigh, skb);
 410                 rcu_read_unlock_bh();
 411                 return ret;
 412         }
 413         rcu_read_unlock_bh();
 414
 415         IP6_INC_STATS(dev_net(dst->dev),
 416                       ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
 417         kfree_skb(skb);
 418         return -EINVAL;
 419 }
 420
 421 /* modelled after ip6_output */
 422 static int vrf_output6(struct net *net, struct sock *sk, struct sk_buff *skb)
 423 {
 424         return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
 425                             net, sk, skb, NULL, skb_dst(skb)->dev,
 426                             vrf_finish_output6,
 427                             !(IP6CB(skb)->flags & IP6SKB_REROUTED));
 428 }
 429
 430 static void vrf_rt6_destroy(struct net_vrf *vrf)
 431 {
 432         dst_destroy(&vrf->rt6->dst);
 433         free_percpu(vrf->rt6->rt6i_pcpu);
 434         vrf->rt6 = NULL;
 435 }
 436
 437 static int vrf_rt6_create(struct net_device *dev)
 438 {
 439         struct net_vrf *vrf = netdev_priv(dev);
 440         struct dst_entry *dst;
 441         struct rt6_info *rt6;
 442         int cpu;
 443         int rc = -ENOMEM;
 444
 445         rt6 = dst_alloc(&vrf_dst_ops6, dev, 0,
 446                         DST_OBSOLETE_NONE,
 447                         (DST_HOST | DST_NOPOLICY | DST_NOXFRM));
 448         if (!rt6)
 449                 goto out;
 450
 451         dst = &rt6->dst;
 452
 453         rt6->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, GFP_KERNEL);
 454         if (!rt6->rt6i_pcpu) {
 455                 dst_destroy(dst);
 456                 goto out;
 457         }
 458         for_each_possible_cpu(cpu) {
 459                 struct rt6_info **p = per_cpu_ptr(rt6->rt6i_pcpu, cpu);
 460                 *p =  NULL;
 461         }
 462
 463         memset(dst + 1, 0, sizeof(*rt6) - sizeof(*dst));
 464
 465         INIT_LIST_HEAD(&rt6->rt6i_siblings);
 466         INIT_LIST_HEAD(&rt6->rt6i_uncached);
 467
 468         rt6->dst.input  = vrf_input6;
 469         rt6->dst.output = vrf_output6;
 470
 471         rt6->rt6i_table = fib6_get_table(dev_net(dev), vrf->tb_id);
 472
 473         atomic_set(&rt6->dst.__refcnt, 2);
 474
 475         vrf->rt6 = rt6;
 476         rc = 0;
 477 out:
 478         return rc;
 479 }
 480 #else
 481 static int init_dst_ops6_kmem_cachep(void)
 482 {
 483         return 0;
 484 }
 485
 486 static void free_dst_ops6_kmem_cachep(void)
 487 {
 488 }
 489
 490 static void vrf_rt6_destroy(struct net_vrf *vrf)
 491 {
 492 }
 493
 494 static int vrf_rt6_create(struct net_device *dev)
 495 {
 496         return 0;
 497 }
 498 #endif
 499
 500 /* modelled after ip_finish_output2 */
 501 static int vrf_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 502 {
 503         struct dst_entry *dst = skb_dst(skb);
 504         struct rtable *rt = (struct rtable *)dst;
 505         struct net_device *dev = dst->dev;
 506         unsigned int hh_len = LL_RESERVED_SPACE(dev);
 507         struct neighbour *neigh;
 508         u32 nexthop;
 509         int ret = -EINVAL;
 510
 511         /* Be paranoid, rather than too clever. */
 512         if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) {
 513                 struct sk_buff *skb2;
 514
 515                 skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev));
 516                 if (!skb2) {
 517                         ret = -ENOMEM;
 518                         goto err;
 519                 }
 520                 if (skb->sk)
 521                         skb_set_owner_w(skb2, skb->sk);
 522
 523                 consume_skb(skb);
 524                 skb = skb2;
 525         }
 526
 527         rcu_read_lock_bh();
 528
 529         nexthop = (__force u32)rt_nexthop(rt, ip_hdr(skb)->daddr);
 530         neigh = __ipv4_neigh_lookup_noref(dev, nexthop);
 531         if (unlikely(!neigh))
 532                 neigh = __neigh_create(&arp_tbl, &nexthop, dev, false);
 533         if (!IS_ERR(neigh))
 534                 ret = dst_neigh_output(dst, neigh, skb);
 535
 536         rcu_read_unlock_bh();
 537 err:
 538         if (unlikely(ret < 0))
 539                 vrf_tx_error(skb->dev, skb);
 540         return ret;
 541 }
 542
 543 static int vrf_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 544 {
 545         struct net_device *dev = skb_dst(skb)->dev;
 546
 547         IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len);
 548
 549         skb->dev = dev;
 550         skb->protocol = htons(ETH_P_IP);
 551
 552         return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING,
 553                             net, sk, skb, NULL, dev,
 554                             vrf_finish_output,
 555                             !(IPCB(skb)->flags & IPSKB_REROUTED));
 556 }
 557
 558 static void vrf_rtable_destroy(struct net_vrf *vrf)
 559 {
 560         struct dst_entry *dst = (struct dst_entry *)vrf->rth;
 561
 562         dst_destroy(dst);
 563         vrf->rth = NULL;
 564 }
 565
 566 static struct rtable *vrf_rtable_create(struct net_device *dev)
 567 {
 568         struct net_vrf *vrf = netdev_priv(dev);
 569         struct rtable *rth;
 570
 571         rth = dst_alloc(&vrf_dst_ops, dev, 2,
 572                         DST_OBSOLETE_NONE,
 573                         (DST_HOST | DST_NOPOLICY | DST_NOXFRM));
 574         if (rth) {
 575                 rth->dst.output = vrf_output;
 576                 rth->rt_genid   = rt_genid_ipv4(dev_net(dev));
 577                 rth->rt_flags   = 0;
 578                 rth->rt_type    = RTN_UNICAST;
 579                 rth->rt_is_input = 0;
 580                 rth->rt_iif     = 0;
 581                 rth->rt_pmtu    = 0;
 582                 rth->rt_gateway = 0;
 583                 rth->rt_uses_gateway = 0;
 584                 rth->rt_table_id = vrf->tb_id;
 585                 INIT_LIST_HEAD(&rth->rt_uncached);
 586                 rth->rt_uncached_list = NULL;
 587         }
 588
 589         return rth;
 590 }
 591
 592 /**************************** device handling ********************/
 593
 594 /* cycle interface to flush neighbor cache and move routes across tables */
 595 static void cycle_netdev(struct net_device *dev)
 596 {
 597         unsigned int flags = dev->flags;
 598         int ret;
 599
 600         if (!netif_running(dev))
 601                 return;
 602
 603         ret = dev_change_flags(dev, flags & ~IFF_UP);
 604         if (ret >= 0)
 605                 ret = dev_change_flags(dev, flags);
 606
 607         if (ret < 0) {
 608                 netdev_err(dev,
 609                            "Failed to cycle device %s; route tables might be wrong!\n",
 610                            dev->name);
 611         }
 612 }
 613
 614 static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev)
 615 {
 616         int ret;
 617
 618         /* register the packet handler for slave ports */
 619         ret = netdev_rx_handler_register(port_dev, vrf_handle_frame, dev);
 620         if (ret) {
 621                 netdev_err(port_dev,
 622                            "Device %s failed to register rx_handler\n",
 623                            port_dev->name);
 624                 goto out_fail;
 625         }
 626
 627         ret = netdev_master_upper_dev_link(port_dev, dev, NULL, NULL);
 628         if (ret < 0)
 629                 goto out_unregister;
 630
 631         port_dev->priv_flags |= IFF_L3MDEV_SLAVE;
 632         cycle_netdev(port_dev);
 633
 634         return 0;
 635
 636 out_unregister:
 637         netdev_rx_handler_unregister(port_dev);
 638 out_fail:
 639         return ret;
 640 }
 641
 642 static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev)
 643 {
 644         if (netif_is_l3_master(port_dev) || netif_is_l3_slave(port_dev))
 645                 return -EINVAL;
 646
 647         return do_vrf_add_slave(dev, port_dev);
 648 }
 649
 650 /* inverse of do_vrf_add_slave */
 651 static int do_vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
 652 {
 653         netdev_upper_dev_unlink(port_dev, dev);
 654         port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
 655
 656         netdev_rx_handler_unregister(port_dev);
 657
 658         cycle_netdev(port_dev);
 659
 660         return 0;
 661 }
 662
 663 static int vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
 664 {
 665         return do_vrf_del_slave(dev, port_dev);
 666 }
 667
 668 static void vrf_dev_uninit(struct net_device *dev)
 669 {
 670         struct net_vrf *vrf = netdev_priv(dev);
 671         struct net_device *port_dev;
 672         struct list_head *iter;
 673
 674         vrf_rtable_destroy(vrf);
 675         vrf_rt6_destroy(vrf);
 676
 677         netdev_for_each_lower_dev(dev, port_dev, iter)
 678                 vrf_del_slave(dev, port_dev);
 679
 680         free_percpu(dev->dstats);
 681         dev->dstats = NULL;
 682 }
 683
 684 static int vrf_dev_init(struct net_device *dev)
 685 {
 686         struct net_vrf *vrf = netdev_priv(dev);
 687
 688         dev->dstats = netdev_alloc_pcpu_stats(struct pcpu_dstats);
 689         if (!dev->dstats)
 690                 goto out_nomem;
 691
 692         /* create the default dst which points back to us */
 693         vrf->rth = vrf_rtable_create(dev);
 694         if (!vrf->rth)
 695                 goto out_stats;
 696
 697         if (vrf_rt6_create(dev) != 0)
 698                 goto out_rth;
 699
 700         dev->flags = IFF_MASTER | IFF_NOARP;
 701
 702         return 0;
 703
 704 out_rth:
 705         vrf_rtable_destroy(vrf);
 706 out_stats:
 707         free_percpu(dev->dstats);
 708         dev->dstats = NULL;
 709 out_nomem:
 710         return -ENOMEM;
 711 }
 712
 713 static const struct net_device_ops vrf_netdev_ops = {
 714         .ndo_init               = vrf_dev_init,
 715         .ndo_uninit             = vrf_dev_uninit,
 716         .ndo_start_xmit         = vrf_xmit,
 717         .ndo_get_stats64        = vrf_get_stats64,
 718         .ndo_add_slave          = vrf_add_slave,
 719         .ndo_del_slave          = vrf_del_slave,
 720 };
 721
 722 static u32 vrf_fib_table(const struct net_device *dev)
 723 {
 724         struct net_vrf *vrf = netdev_priv(dev);
 725
 726         return vrf->tb_id;
 727 }
 728
 729 static struct rtable *vrf_get_rtable(const struct net_device *dev,
 730                                      const struct flowi4 *fl4)
 731 {
 732         struct rtable *rth = NULL;
 733
 734         if (!(fl4->flowi4_flags & FLOWI_FLAG_L3MDEV_SRC)) {
 735                 struct net_vrf *vrf = netdev_priv(dev);
 736
 737                 rth = vrf->rth;
 738                 atomic_inc(&rth->dst.__refcnt);
 739         }
 740
 741         return rth;
 742 }
 743
 744 /* called under rcu_read_lock */
 745 static int vrf_get_saddr(struct net_device *dev, struct flowi4 *fl4)
 746 {
 747         struct fib_result res = { .tclassid = 0 };
 748         struct net *net = dev_net(dev);
 749         u32 orig_tos = fl4->flowi4_tos;
 750         u8 flags = fl4->flowi4_flags;
 751         u8 scope = fl4->flowi4_scope;
 752         u8 tos = RT_FL_TOS(fl4);
 753         int rc;
 754
 755         if (unlikely(!fl4->daddr))
 756                 return 0;
 757
 758         fl4->flowi4_flags |= FLOWI_FLAG_SKIP_NH_OIF;
 759         fl4->flowi4_iif = LOOPBACK_IFINDEX;
 760         fl4->flowi4_tos = tos & IPTOS_RT_MASK;
 761         fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
 762                              RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
 763
 764         rc = fib_lookup(net, fl4, &res, 0);
 765         if (!rc) {
 766                 if (res.type == RTN_LOCAL)
 767                         fl4->saddr = res.fi->fib_prefsrc ? : fl4->daddr;
 768                 else
 769                         fib_select_path(net, &res, fl4, -1);
 770         }
 771
 772         fl4->flowi4_flags = flags;
 773         fl4->flowi4_tos = orig_tos;
 774         fl4->flowi4_scope = scope;
 775
 776         return rc;
 777 }
 778
 779 #if IS_ENABLED(CONFIG_IPV6)
 780 static struct dst_entry *vrf_get_rt6_dst(const struct net_device *dev,
 781                                          const struct flowi6 *fl6)
 782 {
 783         struct rt6_info *rt = NULL;
 784
 785         if (!(fl6->flowi6_flags & FLOWI_FLAG_L3MDEV_SRC)) {
 786                 struct net_vrf *vrf = netdev_priv(dev);
 787
 788                 rt = vrf->rt6;
 789                 atomic_inc(&rt->dst.__refcnt);
 790         }
 791
 792         return (struct dst_entry *)rt;
 793 }
 794 #endif
 795
 796 static const struct l3mdev_ops vrf_l3mdev_ops = {
 797         .l3mdev_fib_table       = vrf_fib_table,
 798         .l3mdev_get_rtable      = vrf_get_rtable,
 799         .l3mdev_get_saddr       = vrf_get_saddr,
 800 #if IS_ENABLED(CONFIG_IPV6)
 801         .l3mdev_get_rt6_dst     = vrf_get_rt6_dst,
 802 #endif
 803 };
 804
 805 static void vrf_get_drvinfo(struct net_device *dev,
 806                             struct ethtool_drvinfo *info)
 807 {
 808         strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
 809         strlcpy(info->version, DRV_VERSION, sizeof(info->version));
 810 }
 811
 812 static const struct ethtool_ops vrf_ethtool_ops = {
 813         .get_drvinfo    = vrf_get_drvinfo,
 814 };
 815
 816 static void vrf_setup(struct net_device *dev)
 817 {
 818         ether_setup(dev);
 819
 820         /* Initialize the device structure. */
 821         dev->netdev_ops = &vrf_netdev_ops;
 822         dev->l3mdev_ops = &vrf_l3mdev_ops;
 823         dev->ethtool_ops = &vrf_ethtool_ops;
 824         dev->destructor = free_netdev;
 825
 826         /* Fill in device structure with ethernet-generic values. */
 827         eth_hw_addr_random(dev);
 828
 829         /* don't acquire vrf device's netif_tx_lock when transmitting */
 830         dev->features |= NETIF_F_LLTX;
 831
 832         /* don't allow vrf devices to change network namespaces. */
 833         dev->features |= NETIF_F_NETNS_LOCAL;
 834 }
 835
 836 static int vrf_validate(struct nlattr *tb[], struct nlattr *data[])
 837 {
 838         if (tb[IFLA_ADDRESS]) {
 839                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
 840                         return -EINVAL;
 841                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
 842                         return -EADDRNOTAVAIL;
 843         }
 844         return 0;
 845 }
 846
 847 static void vrf_dellink(struct net_device *dev, struct list_head *head)
 848 {
 849         unregister_netdevice_queue(dev, head);
 850 }
 851
 852 static int vrf_newlink(struct net *src_net, struct net_device *dev,
 853                        struct nlattr *tb[], struct nlattr *data[])
 854 {
 855         struct net_vrf *vrf = netdev_priv(dev);
 856
 857         if (!data || !data[IFLA_VRF_TABLE])
 858                 return -EINVAL;
 859
 860         vrf->tb_id = nla_get_u32(data[IFLA_VRF_TABLE]);
 861
 862         dev->priv_flags |= IFF_L3MDEV_MASTER;
 863
 864         return register_netdevice(dev);
 865 }
 866
 867 static size_t vrf_nl_getsize(const struct net_device *dev)
 868 {
 869         return nla_total_size(sizeof(u32));  /* IFLA_VRF_TABLE */
 870 }
 871
 872 static int vrf_fillinfo(struct sk_buff *skb,
 873                         const struct net_device *dev)
 874 {
 875         struct net_vrf *vrf = netdev_priv(dev);
 876
 877         return nla_put_u32(skb, IFLA_VRF_TABLE, vrf->tb_id);
 878 }
 879
 880 static const struct nla_policy vrf_nl_policy[IFLA_VRF_MAX + 1] = {
 881         [IFLA_VRF_TABLE] = { .type = NLA_U32 },
 882 };
 883
 884 static struct rtnl_link_ops vrf_link_ops __read_mostly = {
 885         .kind           = DRV_NAME,
 886         .priv_size      = sizeof(struct net_vrf),
 887
 888         .get_size       = vrf_nl_getsize,
 889         .policy         = vrf_nl_policy,
 890         .validate       = vrf_validate,
 891         .fill_info      = vrf_fillinfo,
 892
 893         .newlink        = vrf_newlink,
 894         .dellink        = vrf_dellink,
 895         .setup          = vrf_setup,
 896         .maxtype        = IFLA_VRF_MAX,
 897 };
 898
 899 static int vrf_device_event(struct notifier_block *unused,
 900                             unsigned long event, void *ptr)
 901 {
 902         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 903
 904         /* only care about unregister events to drop slave references */
 905         if (event == NETDEV_UNREGISTER) {
 906                 struct net_device *vrf_dev;
 907
 908                 if (!netif_is_l3_slave(dev))
 909                         goto out;
 910
 911                 vrf_dev = netdev_master_upper_dev_get(dev);
 912                 vrf_del_slave(vrf_dev, dev);
 913         }
 914 out:
 915         return NOTIFY_DONE;
 916 }
 917
 918 static struct notifier_block vrf_notifier_block __read_mostly = {
 919         .notifier_call = vrf_device_event,
 920 };
 921
 922 static int __init vrf_init_module(void)
 923 {
 924         int rc;
 925
 926         vrf_dst_ops.kmem_cachep =
 927                 kmem_cache_create("vrf_ip_dst_cache",
 928                                   sizeof(struct rtable), 0,
 929                                   SLAB_HWCACHE_ALIGN,
 930                                   NULL);
 931
 932         if (!vrf_dst_ops.kmem_cachep)
 933                 return -ENOMEM;
 934
 935         rc = init_dst_ops6_kmem_cachep();
 936         if (rc != 0)
 937                 goto error2;
 938
 939         register_netdevice_notifier(&vrf_notifier_block);
 940
 941         rc = rtnl_link_register(&vrf_link_ops);
 942         if (rc < 0)
 943                 goto error;
 944
 945         return 0;
 946
 947 error:
 948         unregister_netdevice_notifier(&vrf_notifier_block);
 949         free_dst_ops6_kmem_cachep();
 950 error2:
 951         kmem_cache_destroy(vrf_dst_ops.kmem_cachep);
 952         return rc;
 953 }
 954
 955 static void __exit vrf_cleanup_module(void)
 956 {
 957         rtnl_link_unregister(&vrf_link_ops);
 958         unregister_netdevice_notifier(&vrf_notifier_block);
 959         kmem_cache_destroy(vrf_dst_ops.kmem_cachep);
 960         free_dst_ops6_kmem_cachep();
 961 }
 962
 963 module_init(vrf_init_module);
 964 module_exit(vrf_cleanup_module);
 965 MODULE_AUTHOR("Shrijeet Mukherjee, David Ahern");
 966 MODULE_DESCRIPTION("Device driver to instantiate VRF domains");
 967 MODULE_LICENSE("GPL");
 968 MODULE_ALIAS_RTNL_LINK(DRV_NAME);
 969 MODULE_VERSION(DRV_VERSION);