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 slave {
  50         struct list_head        list;
  51         struct net_device       *dev;
  52 };
  53
  54 struct slave_queue {
  55         struct list_head        all_slaves;
  56 };
  57
  58 struct net_vrf {
  59         struct slave_queue      queue;
  60         struct rtable           *rth;
  61         struct rt6_info         *rt6;
  62         u32                     tb_id;
  63 };
  64
  65 struct pcpu_dstats {
  66         u64                     tx_pkts;
  67         u64                     tx_bytes;
  68         u64                     tx_drps;
  69         u64                     rx_pkts;
  70         u64                     rx_bytes;
  71         struct u64_stats_sync   syncp;
  72 };
  73
  74 static struct dst_entry *vrf_ip_check(struct dst_entry *dst, u32 cookie)
  75 {
  76         return dst;
  77 }
  78
  79 static int vrf_ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb)
  80 {
  81         return ip_local_out(net, sk, skb);
  82 }
  83
  84 static unsigned int vrf_v4_mtu(const struct dst_entry *dst)
  85 {
  86         /* TO-DO: return max ethernet size? */
  87         return dst->dev->mtu;
  88 }
  89
  90 static void vrf_dst_destroy(struct dst_entry *dst)
  91 {
  92         /* our dst lives forever - or until the device is closed */
  93 }
  94
  95 static unsigned int vrf_default_advmss(const struct dst_entry *dst)
  96 {
  97         return 65535 - 40;
  98 }
  99
 100 static struct dst_ops vrf_dst_ops = {
 101         .family         = AF_INET,
 102         .local_out      = vrf_ip_local_out,
 103         .check          = vrf_ip_check,
 104         .mtu            = vrf_v4_mtu,
 105         .destroy        = vrf_dst_destroy,
 106         .default_advmss = vrf_default_advmss,
 107 };
 108
 109 /* neighbor handling is done with actual device; do not want
 110  * to flip skb->dev for those ndisc packets. This really fails
 111  * for multiple next protocols (e.g., NEXTHDR_HOP). But it is
 112  * a start.
 113  */
 114 #if IS_ENABLED(CONFIG_IPV6)
 115 static bool check_ipv6_frame(const struct sk_buff *skb)
 116 {
 117         const struct ipv6hdr *ipv6h = (struct ipv6hdr *)skb->data;
 118         size_t hlen = sizeof(*ipv6h);
 119         bool rc = true;
 120
 121         if (skb->len < hlen)
 122                 goto out;
 123
 124         if (ipv6h->nexthdr == NEXTHDR_ICMP) {
 125                 const struct icmp6hdr *icmph;
 126
 127                 if (skb->len < hlen + sizeof(*icmph))
 128                         goto out;
 129
 130                 icmph = (struct icmp6hdr *)(skb->data + sizeof(*ipv6h));
 131                 switch (icmph->icmp6_type) {
 132                 case NDISC_ROUTER_SOLICITATION:
 133                 case NDISC_ROUTER_ADVERTISEMENT:
 134                 case NDISC_NEIGHBOUR_SOLICITATION:
 135                 case NDISC_NEIGHBOUR_ADVERTISEMENT:
 136                 case NDISC_REDIRECT:
 137                         rc = false;
 138                         break;
 139                 }
 140         }
 141
 142 out:
 143         return rc;
 144 }
 145 #else
 146 static bool check_ipv6_frame(const struct sk_buff *skb)
 147 {
 148         return false;
 149 }
 150 #endif
 151
 152 static bool is_ip_rx_frame(struct sk_buff *skb)
 153 {
 154         switch (skb->protocol) {
 155         case htons(ETH_P_IP):
 156                 return true;
 157         case htons(ETH_P_IPV6):
 158                 return check_ipv6_frame(skb);
 159         }
 160         return false;
 161 }
 162
 163 static void vrf_tx_error(struct net_device *vrf_dev, struct sk_buff *skb)
 164 {
 165         vrf_dev->stats.tx_errors++;
 166         kfree_skb(skb);
 167 }
 168
 169 /* note: already called with rcu_read_lock */
 170 static rx_handler_result_t vrf_handle_frame(struct sk_buff **pskb)
 171 {
 172         struct sk_buff *skb = *pskb;
 173
 174         if (is_ip_rx_frame(skb)) {
 175                 struct net_device *dev = vrf_master_get_rcu(skb->dev);
 176                 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
 177
 178                 u64_stats_update_begin(&dstats->syncp);
 179                 dstats->rx_pkts++;
 180                 dstats->rx_bytes += skb->len;
 181                 u64_stats_update_end(&dstats->syncp);
 182
 183                 skb->dev = dev;
 184
 185                 return RX_HANDLER_ANOTHER;
 186         }
 187         return RX_HANDLER_PASS;
 188 }
 189
 190 static struct rtnl_link_stats64 *vrf_get_stats64(struct net_device *dev,
 191                                                  struct rtnl_link_stats64 *stats)
 192 {
 193         int i;
 194
 195         for_each_possible_cpu(i) {
 196                 const struct pcpu_dstats *dstats;
 197                 u64 tbytes, tpkts, tdrops, rbytes, rpkts;
 198                 unsigned int start;
 199
 200                 dstats = per_cpu_ptr(dev->dstats, i);
 201                 do {
 202                         start = u64_stats_fetch_begin_irq(&dstats->syncp);
 203                         tbytes = dstats->tx_bytes;
 204                         tpkts = dstats->tx_pkts;
 205                         tdrops = dstats->tx_drps;
 206                         rbytes = dstats->rx_bytes;
 207                         rpkts = dstats->rx_pkts;
 208                 } while (u64_stats_fetch_retry_irq(&dstats->syncp, start));
 209                 stats->tx_bytes += tbytes;
 210                 stats->tx_packets += tpkts;
 211                 stats->tx_dropped += tdrops;
 212                 stats->rx_bytes += rbytes;
 213                 stats->rx_packets += rpkts;
 214         }
 215         return stats;
 216 }
 217
 218 #if IS_ENABLED(CONFIG_IPV6)
 219 static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
 220                                            struct net_device *dev)
 221 {
 222         const struct ipv6hdr *iph = ipv6_hdr(skb);
 223         struct net *net = dev_net(skb->dev);
 224         struct flowi6 fl6 = {
 225                 /* needed to match OIF rule */
 226                 .flowi6_oif = dev->ifindex,
 227                 .flowi6_iif = LOOPBACK_IFINDEX,
 228                 .daddr = iph->daddr,
 229                 .saddr = iph->saddr,
 230                 .flowlabel = ip6_flowinfo(iph),
 231                 .flowi6_mark = skb->mark,
 232                 .flowi6_proto = iph->nexthdr,
 233                 .flowi6_flags = FLOWI_FLAG_L3MDEV_SRC | FLOWI_FLAG_SKIP_NH_OIF,
 234         };
 235         int ret = NET_XMIT_DROP;
 236         struct dst_entry *dst;
 237         struct dst_entry *dst_null = &net->ipv6.ip6_null_entry->dst;
 238
 239         dst = ip6_route_output(net, NULL, &fl6);
 240         if (dst == dst_null)
 241                 goto err;
 242
 243         skb_dst_drop(skb);
 244         skb_dst_set(skb, dst);
 245
 246         ret = ip6_local_out(net, skb->sk, skb);
 247         if (unlikely(net_xmit_eval(ret)))
 248                 dev->stats.tx_errors++;
 249         else
 250                 ret = NET_XMIT_SUCCESS;
 251
 252         return ret;
 253 err:
 254         vrf_tx_error(dev, skb);
 255         return NET_XMIT_DROP;
 256 }
 257 #else
 258 static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
 259                                            struct net_device *dev)
 260 {
 261         vrf_tx_error(dev, skb);
 262         return NET_XMIT_DROP;
 263 }
 264 #endif
 265
 266 static int vrf_send_v4_prep(struct sk_buff *skb, struct flowi4 *fl4,
 267                             struct net_device *vrf_dev)
 268 {
 269         struct rtable *rt;
 270         int err = 1;
 271
 272         rt = ip_route_output_flow(dev_net(vrf_dev), fl4, NULL);
 273         if (IS_ERR(rt))
 274                 goto out;
 275
 276         /* TO-DO: what about broadcast ? */
 277         if (rt->rt_type != RTN_UNICAST && rt->rt_type != RTN_LOCAL) {
 278                 ip_rt_put(rt);
 279                 goto out;
 280         }
 281
 282         skb_dst_drop(skb);
 283         skb_dst_set(skb, &rt->dst);
 284         err = 0;
 285 out:
 286         return err;
 287 }
 288
 289 static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb,
 290                                            struct net_device *vrf_dev)
 291 {
 292         struct iphdr *ip4h = ip_hdr(skb);
 293         int ret = NET_XMIT_DROP;
 294         struct flowi4 fl4 = {
 295                 /* needed to match OIF rule */
 296                 .flowi4_oif = vrf_dev->ifindex,
 297                 .flowi4_iif = LOOPBACK_IFINDEX,
 298                 .flowi4_tos = RT_TOS(ip4h->tos),
 299                 .flowi4_flags = FLOWI_FLAG_ANYSRC | FLOWI_FLAG_L3MDEV_SRC |
 300                                 FLOWI_FLAG_SKIP_NH_OIF,
 301                 .daddr = ip4h->daddr,
 302         };
 303
 304         if (vrf_send_v4_prep(skb, &fl4, vrf_dev))
 305                 goto err;
 306
 307         if (!ip4h->saddr) {
 308                 ip4h->saddr = inet_select_addr(skb_dst(skb)->dev, 0,
 309                                                RT_SCOPE_LINK);
 310         }
 311
 312         ret = ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
 313         if (unlikely(net_xmit_eval(ret)))
 314                 vrf_dev->stats.tx_errors++;
 315         else
 316                 ret = NET_XMIT_SUCCESS;
 317
 318 out:
 319         return ret;
 320 err:
 321         vrf_tx_error(vrf_dev, skb);
 322         goto out;
 323 }
 324
 325 static netdev_tx_t is_ip_tx_frame(struct sk_buff *skb, struct net_device *dev)
 326 {
 327         /* strip the ethernet header added for pass through VRF device */
 328         __skb_pull(skb, skb_network_offset(skb));
 329
 330         switch (skb->protocol) {
 331         case htons(ETH_P_IP):
 332                 return vrf_process_v4_outbound(skb, dev);
 333         case htons(ETH_P_IPV6):
 334                 return vrf_process_v6_outbound(skb, dev);
 335         default:
 336                 vrf_tx_error(dev, skb);
 337                 return NET_XMIT_DROP;
 338         }
 339 }
 340
 341 static netdev_tx_t vrf_xmit(struct sk_buff *skb, struct net_device *dev)
 342 {
 343         netdev_tx_t ret = is_ip_tx_frame(skb, dev);
 344
 345         if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) {
 346                 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
 347
 348                 u64_stats_update_begin(&dstats->syncp);
 349                 dstats->tx_pkts++;
 350                 dstats->tx_bytes += skb->len;
 351                 u64_stats_update_end(&dstats->syncp);
 352         } else {
 353                 this_cpu_inc(dev->dstats->tx_drps);
 354         }
 355
 356         return ret;
 357 }
 358
 359 #if IS_ENABLED(CONFIG_IPV6)
 360 static struct dst_entry *vrf_ip6_check(struct dst_entry *dst, u32 cookie)
 361 {
 362         return dst;
 363 }
 364
 365 static struct dst_ops vrf_dst_ops6 = {
 366         .family         = AF_INET6,
 367         .local_out      = ip6_local_out,
 368         .check          = vrf_ip6_check,
 369         .mtu            = vrf_v4_mtu,
 370         .destroy        = vrf_dst_destroy,
 371         .default_advmss = vrf_default_advmss,
 372 };
 373
 374 static int init_dst_ops6_kmem_cachep(void)
 375 {
 376         vrf_dst_ops6.kmem_cachep = kmem_cache_create("vrf_ip6_dst_cache",
 377                                                      sizeof(struct rt6_info),
 378                                                      0,
 379                                                      SLAB_HWCACHE_ALIGN,
 380                                                      NULL);
 381
 382         if (!vrf_dst_ops6.kmem_cachep)
 383                 return -ENOMEM;
 384
 385         return 0;
 386 }
 387
 388 static void free_dst_ops6_kmem_cachep(void)
 389 {
 390         kmem_cache_destroy(vrf_dst_ops6.kmem_cachep);
 391 }
 392
 393 static int vrf_input6(struct sk_buff *skb)
 394 {
 395         skb->dev->stats.rx_errors++;
 396         kfree_skb(skb);
 397         return 0;
 398 }
 399
 400 /* modelled after ip6_finish_output2 */
 401 static int vrf_finish_output6(struct net *net, struct sock *sk,
 402                               struct sk_buff *skb)
 403 {
 404         struct dst_entry *dst = skb_dst(skb);
 405         struct net_device *dev = dst->dev;
 406         struct neighbour *neigh;
 407         struct in6_addr *nexthop;
 408         int ret;
 409
 410         skb->protocol = htons(ETH_P_IPV6);
 411         skb->dev = dev;
 412
 413         rcu_read_lock_bh();
 414         nexthop = rt6_nexthop((struct rt6_info *)dst, &ipv6_hdr(skb)->daddr);
 415         neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop);
 416         if (unlikely(!neigh))
 417                 neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false);
 418         if (!IS_ERR(neigh)) {
 419                 ret = dst_neigh_output(dst, neigh, skb);
 420                 rcu_read_unlock_bh();
 421                 return ret;
 422         }
 423         rcu_read_unlock_bh();
 424
 425         IP6_INC_STATS(dev_net(dst->dev),
 426                       ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
 427         kfree_skb(skb);
 428         return -EINVAL;
 429 }
 430
 431 /* modelled after ip6_output */
 432 static int vrf_output6(struct net *net, struct sock *sk, struct sk_buff *skb)
 433 {
 434         return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
 435                             net, sk, skb, NULL, skb_dst(skb)->dev,
 436                             vrf_finish_output6,
 437                             !(IP6CB(skb)->flags & IP6SKB_REROUTED));
 438 }
 439
 440 static void vrf_rt6_destroy(struct net_vrf *vrf)
 441 {
 442         dst_destroy(&vrf->rt6->dst);
 443         free_percpu(vrf->rt6->rt6i_pcpu);
 444         vrf->rt6 = NULL;
 445 }
 446
 447 static int vrf_rt6_create(struct net_device *dev)
 448 {
 449         struct net_vrf *vrf = netdev_priv(dev);
 450         struct dst_entry *dst;
 451         struct rt6_info *rt6;
 452         int cpu;
 453         int rc = -ENOMEM;
 454
 455         rt6 = dst_alloc(&vrf_dst_ops6, dev, 0,
 456                         DST_OBSOLETE_NONE,
 457                         (DST_HOST | DST_NOPOLICY | DST_NOXFRM));
 458         if (!rt6)
 459                 goto out;
 460
 461         dst = &rt6->dst;
 462
 463         rt6->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, GFP_KERNEL);
 464         if (!rt6->rt6i_pcpu) {
 465                 dst_destroy(dst);
 466                 goto out;
 467         }
 468         for_each_possible_cpu(cpu) {
 469                 struct rt6_info **p = per_cpu_ptr(rt6->rt6i_pcpu, cpu);
 470                 *p =  NULL;
 471         }
 472
 473         memset(dst + 1, 0, sizeof(*rt6) - sizeof(*dst));
 474
 475         INIT_LIST_HEAD(&rt6->rt6i_siblings);
 476         INIT_LIST_HEAD(&rt6->rt6i_uncached);
 477
 478         rt6->dst.input  = vrf_input6;
 479         rt6->dst.output = vrf_output6;
 480
 481         rt6->rt6i_table = fib6_get_table(dev_net(dev), vrf->tb_id);
 482
 483         atomic_set(&rt6->dst.__refcnt, 2);
 484
 485         vrf->rt6 = rt6;
 486         rc = 0;
 487 out:
 488         return rc;
 489 }
 490 #else
 491 static int init_dst_ops6_kmem_cachep(void)
 492 {
 493         return 0;
 494 }
 495
 496 static void free_dst_ops6_kmem_cachep(void)
 497 {
 498 }
 499
 500 static void vrf_rt6_destroy(struct net_vrf *vrf)
 501 {
 502 }
 503
 504 static int vrf_rt6_create(struct net_device *dev)
 505 {
 506         return 0;
 507 }
 508 #endif
 509
 510 /* modelled after ip_finish_output2 */
 511 static int vrf_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 512 {
 513         struct dst_entry *dst = skb_dst(skb);
 514         struct rtable *rt = (struct rtable *)dst;
 515         struct net_device *dev = dst->dev;
 516         unsigned int hh_len = LL_RESERVED_SPACE(dev);
 517         struct neighbour *neigh;
 518         u32 nexthop;
 519         int ret = -EINVAL;
 520
 521         /* Be paranoid, rather than too clever. */
 522         if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) {
 523                 struct sk_buff *skb2;
 524
 525                 skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev));
 526                 if (!skb2) {
 527                         ret = -ENOMEM;
 528                         goto err;
 529                 }
 530                 if (skb->sk)
 531                         skb_set_owner_w(skb2, skb->sk);
 532
 533                 consume_skb(skb);
 534                 skb = skb2;
 535         }
 536
 537         rcu_read_lock_bh();
 538
 539         nexthop = (__force u32)rt_nexthop(rt, ip_hdr(skb)->daddr);
 540         neigh = __ipv4_neigh_lookup_noref(dev, nexthop);
 541         if (unlikely(!neigh))
 542                 neigh = __neigh_create(&arp_tbl, &nexthop, dev, false);
 543         if (!IS_ERR(neigh))
 544                 ret = dst_neigh_output(dst, neigh, skb);
 545
 546         rcu_read_unlock_bh();
 547 err:
 548         if (unlikely(ret < 0))
 549                 vrf_tx_error(skb->dev, skb);
 550         return ret;
 551 }
 552
 553 static int vrf_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 554 {
 555         struct net_device *dev = skb_dst(skb)->dev;
 556
 557         IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len);
 558
 559         skb->dev = dev;
 560         skb->protocol = htons(ETH_P_IP);
 561
 562         return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING,
 563                             net, sk, skb, NULL, dev,
 564                             vrf_finish_output,
 565                             !(IPCB(skb)->flags & IPSKB_REROUTED));
 566 }
 567
 568 static void vrf_rtable_destroy(struct net_vrf *vrf)
 569 {
 570         struct dst_entry *dst = (struct dst_entry *)vrf->rth;
 571
 572         dst_destroy(dst);
 573         vrf->rth = NULL;
 574 }
 575
 576 static struct rtable *vrf_rtable_create(struct net_device *dev)
 577 {
 578         struct net_vrf *vrf = netdev_priv(dev);
 579         struct rtable *rth;
 580
 581         rth = dst_alloc(&vrf_dst_ops, dev, 2,
 582                         DST_OBSOLETE_NONE,
 583                         (DST_HOST | DST_NOPOLICY | DST_NOXFRM));
 584         if (rth) {
 585                 rth->dst.output = vrf_output;
 586                 rth->rt_genid   = rt_genid_ipv4(dev_net(dev));
 587                 rth->rt_flags   = 0;
 588                 rth->rt_type    = RTN_UNICAST;
 589                 rth->rt_is_input = 0;
 590                 rth->rt_iif     = 0;
 591                 rth->rt_pmtu    = 0;
 592                 rth->rt_gateway = 0;
 593                 rth->rt_uses_gateway = 0;
 594                 rth->rt_table_id = vrf->tb_id;
 595                 INIT_LIST_HEAD(&rth->rt_uncached);
 596                 rth->rt_uncached_list = NULL;
 597         }
 598
 599         return rth;
 600 }
 601
 602 /**************************** device handling ********************/
 603
 604 /* cycle interface to flush neighbor cache and move routes across tables */
 605 static void cycle_netdev(struct net_device *dev)
 606 {
 607         unsigned int flags = dev->flags;
 608         int ret;
 609
 610         if (!netif_running(dev))
 611                 return;
 612
 613         ret = dev_change_flags(dev, flags & ~IFF_UP);
 614         if (ret >= 0)
 615                 ret = dev_change_flags(dev, flags);
 616
 617         if (ret < 0) {
 618                 netdev_err(dev,
 619                            "Failed to cycle device %s; route tables might be wrong!\n",
 620                            dev->name);
 621         }
 622 }
 623
 624 static struct slave *__vrf_find_slave_dev(struct slave_queue *queue,
 625                                           struct net_device *dev)
 626 {
 627         struct list_head *head = &queue->all_slaves;
 628         struct slave *slave;
 629
 630         list_for_each_entry(slave, head, list) {
 631                 if (slave->dev == dev)
 632                         return slave;
 633         }
 634
 635         return NULL;
 636 }
 637
 638 /* inverse of __vrf_insert_slave */
 639 static void __vrf_remove_slave(struct slave_queue *queue, struct slave *slave)
 640 {
 641         list_del(&slave->list);
 642 }
 643
 644 static void __vrf_insert_slave(struct slave_queue *queue, struct slave *slave)
 645 {
 646         list_add(&slave->list, &queue->all_slaves);
 647 }
 648
 649 static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev)
 650 {
 651         struct slave *slave = kzalloc(sizeof(*slave), GFP_KERNEL);
 652         struct net_vrf *vrf = netdev_priv(dev);
 653         struct slave_queue *queue = &vrf->queue;
 654         int ret = -ENOMEM;
 655
 656         if (!slave)
 657                 goto out_fail;
 658
 659         slave->dev = port_dev;
 660
 661         /* register the packet handler for slave ports */
 662         ret = netdev_rx_handler_register(port_dev, vrf_handle_frame, dev);
 663         if (ret) {
 664                 netdev_err(port_dev,
 665                            "Device %s failed to register rx_handler\n",
 666                            port_dev->name);
 667                 goto out_fail;
 668         }
 669
 670         ret = netdev_master_upper_dev_link(port_dev, dev);
 671         if (ret < 0)
 672                 goto out_unregister;
 673
 674         port_dev->priv_flags |= IFF_L3MDEV_SLAVE;
 675         __vrf_insert_slave(queue, slave);
 676         cycle_netdev(port_dev);
 677
 678         return 0;
 679
 680 out_unregister:
 681         netdev_rx_handler_unregister(port_dev);
 682 out_fail:
 683         kfree(slave);
 684         return ret;
 685 }
 686
 687 static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev)
 688 {
 689         if (netif_is_l3_master(port_dev) || netif_is_l3_slave(port_dev))
 690                 return -EINVAL;
 691
 692         return do_vrf_add_slave(dev, port_dev);
 693 }
 694
 695 /* inverse of do_vrf_add_slave */
 696 static int do_vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
 697 {
 698         struct net_vrf *vrf = netdev_priv(dev);
 699         struct slave_queue *queue = &vrf->queue;
 700         struct slave *slave;
 701
 702         netdev_upper_dev_unlink(port_dev, dev);
 703         port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
 704
 705         netdev_rx_handler_unregister(port_dev);
 706
 707         cycle_netdev(port_dev);
 708
 709         slave = __vrf_find_slave_dev(queue, port_dev);
 710         if (slave)
 711                 __vrf_remove_slave(queue, slave);
 712
 713         kfree(slave);
 714
 715         return 0;
 716 }
 717
 718 static int vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
 719 {
 720         return do_vrf_del_slave(dev, port_dev);
 721 }
 722
 723 static void vrf_dev_uninit(struct net_device *dev)
 724 {
 725         struct net_vrf *vrf = netdev_priv(dev);
 726         struct slave_queue *queue = &vrf->queue;
 727         struct list_head *head = &queue->all_slaves;
 728         struct slave *slave, *next;
 729
 730         vrf_rtable_destroy(vrf);
 731         vrf_rt6_destroy(vrf);
 732
 733         list_for_each_entry_safe(slave, next, head, list)
 734                 vrf_del_slave(dev, slave->dev);
 735
 736         free_percpu(dev->dstats);
 737         dev->dstats = NULL;
 738 }
 739
 740 static int vrf_dev_init(struct net_device *dev)
 741 {
 742         struct net_vrf *vrf = netdev_priv(dev);
 743
 744         INIT_LIST_HEAD(&vrf->queue.all_slaves);
 745
 746         dev->dstats = netdev_alloc_pcpu_stats(struct pcpu_dstats);
 747         if (!dev->dstats)
 748                 goto out_nomem;
 749
 750         /* create the default dst which points back to us */
 751         vrf->rth = vrf_rtable_create(dev);
 752         if (!vrf->rth)
 753                 goto out_stats;
 754
 755         if (vrf_rt6_create(dev) != 0)
 756                 goto out_rth;
 757
 758         dev->flags = IFF_MASTER | IFF_NOARP;
 759
 760         return 0;
 761
 762 out_rth:
 763         vrf_rtable_destroy(vrf);
 764 out_stats:
 765         free_percpu(dev->dstats);
 766         dev->dstats = NULL;
 767 out_nomem:
 768         return -ENOMEM;
 769 }
 770
 771 static const struct net_device_ops vrf_netdev_ops = {
 772         .ndo_init               = vrf_dev_init,
 773         .ndo_uninit             = vrf_dev_uninit,
 774         .ndo_start_xmit         = vrf_xmit,
 775         .ndo_get_stats64        = vrf_get_stats64,
 776         .ndo_add_slave          = vrf_add_slave,
 777         .ndo_del_slave          = vrf_del_slave,
 778 };
 779
 780 static u32 vrf_fib_table(const struct net_device *dev)
 781 {
 782         struct net_vrf *vrf = netdev_priv(dev);
 783
 784         return vrf->tb_id;
 785 }
 786
 787 static struct rtable *vrf_get_rtable(const struct net_device *dev,
 788                                      const struct flowi4 *fl4)
 789 {
 790         struct rtable *rth = NULL;
 791
 792         if (!(fl4->flowi4_flags & FLOWI_FLAG_L3MDEV_SRC)) {
 793                 struct net_vrf *vrf = netdev_priv(dev);
 794
 795                 rth = vrf->rth;
 796                 atomic_inc(&rth->dst.__refcnt);
 797         }
 798
 799         return rth;
 800 }
 801
 802 /* called under rcu_read_lock */
 803 static void vrf_get_saddr(struct net_device *dev, struct flowi4 *fl4)
 804 {
 805         struct fib_result res = { .tclassid = 0 };
 806         struct net *net = dev_net(dev);
 807         u32 orig_tos = fl4->flowi4_tos;
 808         u8 flags = fl4->flowi4_flags;
 809         u8 scope = fl4->flowi4_scope;
 810         u8 tos = RT_FL_TOS(fl4);
 811
 812         if (unlikely(!fl4->daddr))
 813                 return;
 814
 815         fl4->flowi4_flags |= FLOWI_FLAG_SKIP_NH_OIF;
 816         fl4->flowi4_iif = LOOPBACK_IFINDEX;
 817         fl4->flowi4_tos = tos & IPTOS_RT_MASK;
 818         fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
 819                              RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
 820
 821         if (!fib_lookup(net, fl4, &res, 0)) {
 822                 if (res.type == RTN_LOCAL)
 823                         fl4->saddr = res.fi->fib_prefsrc ? : fl4->daddr;
 824                 else
 825                         fib_select_path(net, &res, fl4, -1);
 826         }
 827
 828         fl4->flowi4_flags = flags;
 829         fl4->flowi4_tos = orig_tos;
 830         fl4->flowi4_scope = scope;
 831 }
 832
 833 #if IS_ENABLED(CONFIG_IPV6)
 834 static struct dst_entry *vrf_get_rt6_dst(const struct net_device *dev,
 835                                          const struct flowi6 *fl6)
 836 {
 837         struct rt6_info *rt = NULL;
 838
 839         if (!(fl6->flowi6_flags & FLOWI_FLAG_L3MDEV_SRC)) {
 840                 struct net_vrf *vrf = netdev_priv(dev);
 841
 842                 rt = vrf->rt6;
 843                 atomic_inc(&rt->dst.__refcnt);
 844         }
 845
 846         return (struct dst_entry *)rt;
 847 }
 848 #endif
 849
 850 static const struct l3mdev_ops vrf_l3mdev_ops = {
 851         .l3mdev_fib_table       = vrf_fib_table,
 852         .l3mdev_get_rtable      = vrf_get_rtable,
 853         .l3mdev_get_saddr       = vrf_get_saddr,
 854 #if IS_ENABLED(CONFIG_IPV6)
 855         .l3mdev_get_rt6_dst     = vrf_get_rt6_dst,
 856 #endif
 857 };
 858
 859 static void vrf_get_drvinfo(struct net_device *dev,
 860                             struct ethtool_drvinfo *info)
 861 {
 862         strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
 863         strlcpy(info->version, DRV_VERSION, sizeof(info->version));
 864 }
 865
 866 static const struct ethtool_ops vrf_ethtool_ops = {
 867         .get_drvinfo    = vrf_get_drvinfo,
 868 };
 869
 870 static void vrf_setup(struct net_device *dev)
 871 {
 872         ether_setup(dev);
 873
 874         /* Initialize the device structure. */
 875         dev->netdev_ops = &vrf_netdev_ops;
 876         dev->l3mdev_ops = &vrf_l3mdev_ops;
 877         dev->ethtool_ops = &vrf_ethtool_ops;
 878         dev->destructor = free_netdev;
 879
 880         /* Fill in device structure with ethernet-generic values. */
 881         eth_hw_addr_random(dev);
 882
 883         /* don't acquire vrf device's netif_tx_lock when transmitting */
 884         dev->features |= NETIF_F_LLTX;
 885
 886         /* don't allow vrf devices to change network namespaces. */
 887         dev->features |= NETIF_F_NETNS_LOCAL;
 888 }
 889
 890 static int vrf_validate(struct nlattr *tb[], struct nlattr *data[])
 891 {
 892         if (tb[IFLA_ADDRESS]) {
 893                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
 894                         return -EINVAL;
 895                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
 896                         return -EADDRNOTAVAIL;
 897         }
 898         return 0;
 899 }
 900
 901 static void vrf_dellink(struct net_device *dev, struct list_head *head)
 902 {
 903         unregister_netdevice_queue(dev, head);
 904 }
 905
 906 static int vrf_newlink(struct net *src_net, struct net_device *dev,
 907                        struct nlattr *tb[], struct nlattr *data[])
 908 {
 909         struct net_vrf *vrf = netdev_priv(dev);
 910
 911         if (!data || !data[IFLA_VRF_TABLE])
 912                 return -EINVAL;
 913
 914         vrf->tb_id = nla_get_u32(data[IFLA_VRF_TABLE]);
 915
 916         dev->priv_flags |= IFF_L3MDEV_MASTER;
 917
 918         return register_netdevice(dev);
 919 }
 920
 921 static size_t vrf_nl_getsize(const struct net_device *dev)
 922 {
 923         return nla_total_size(sizeof(u32));  /* IFLA_VRF_TABLE */
 924 }
 925
 926 static int vrf_fillinfo(struct sk_buff *skb,
 927                         const struct net_device *dev)
 928 {
 929         struct net_vrf *vrf = netdev_priv(dev);
 930
 931         return nla_put_u32(skb, IFLA_VRF_TABLE, vrf->tb_id);
 932 }
 933
 934 static const struct nla_policy vrf_nl_policy[IFLA_VRF_MAX + 1] = {
 935         [IFLA_VRF_TABLE] = { .type = NLA_U32 },
 936 };
 937
 938 static struct rtnl_link_ops vrf_link_ops __read_mostly = {
 939         .kind           = DRV_NAME,
 940         .priv_size      = sizeof(struct net_vrf),
 941
 942         .get_size       = vrf_nl_getsize,
 943         .policy         = vrf_nl_policy,
 944         .validate       = vrf_validate,
 945         .fill_info      = vrf_fillinfo,
 946
 947         .newlink        = vrf_newlink,
 948         .dellink        = vrf_dellink,
 949         .setup          = vrf_setup,
 950         .maxtype        = IFLA_VRF_MAX,
 951 };
 952
 953 static int vrf_device_event(struct notifier_block *unused,
 954                             unsigned long event, void *ptr)
 955 {
 956         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 957
 958         /* only care about unregister events to drop slave references */
 959         if (event == NETDEV_UNREGISTER) {
 960                 struct net_device *vrf_dev;
 961
 962                 if (!netif_is_l3_slave(dev))
 963                         goto out;
 964
 965                 vrf_dev = netdev_master_upper_dev_get(dev);
 966                 vrf_del_slave(vrf_dev, dev);
 967         }
 968 out:
 969         return NOTIFY_DONE;
 970 }
 971
 972 static struct notifier_block vrf_notifier_block __read_mostly = {
 973         .notifier_call = vrf_device_event,
 974 };
 975
 976 static int __init vrf_init_module(void)
 977 {
 978         int rc;
 979
 980         vrf_dst_ops.kmem_cachep =
 981                 kmem_cache_create("vrf_ip_dst_cache",
 982                                   sizeof(struct rtable), 0,
 983                                   SLAB_HWCACHE_ALIGN,
 984                                   NULL);
 985
 986         if (!vrf_dst_ops.kmem_cachep)
 987                 return -ENOMEM;
 988
 989         rc = init_dst_ops6_kmem_cachep();
 990         if (rc != 0)
 991                 goto error2;
 992
 993         register_netdevice_notifier(&vrf_notifier_block);
 994
 995         rc = rtnl_link_register(&vrf_link_ops);
 996         if (rc < 0)
 997                 goto error;
 998
 999         return 0;
1000
1001 error:
1002         unregister_netdevice_notifier(&vrf_notifier_block);
1003         free_dst_ops6_kmem_cachep();
1004 error2:
1005         kmem_cache_destroy(vrf_dst_ops.kmem_cachep);
1006         return rc;
1007 }
1008
1009 static void __exit vrf_cleanup_module(void)
1010 {
1011         rtnl_link_unregister(&vrf_link_ops);
1012         unregister_netdevice_notifier(&vrf_notifier_block);
1013         kmem_cache_destroy(vrf_dst_ops.kmem_cachep);
1014         free_dst_ops6_kmem_cachep();
1015 }
1016
1017 module_init(vrf_init_module);
1018 module_exit(vrf_cleanup_module);
1019 MODULE_AUTHOR("Shrijeet Mukherjee, David Ahern");
1020 MODULE_DESCRIPTION("Device driver to instantiate VRF domains");
1021 MODULE_LICENSE("GPL");
1022 MODULE_ALIAS_RTNL_LINK(DRV_NAME);
1023 MODULE_VERSION(DRV_VERSION);